[From the U.S. Government Printing Office, www.gpo.gov]





                                                                                               OCS ElS/EA
                                                                                               MMS 92-"7
          Gulf of Mexico
          Sales 142 and 143:

          Central and Western Planning Areas

          Draft Environmental Impact Statement

          Volume II: Sections IV.D. through IX





                                                              L                            U
                                                        MS MAI    V'Saco
                                                       GLdft                arm C-dy,".
                                   LOUISIANA                                            FLORIDA"',
                  TEXAS                           Nft
                                                  0                                    Y
                                                  fie
                        Houiston


                            Galveston
                                                                                            Tampa




                               DEFERRED
                                                  CENTRAL
           Ccar.rl.
                                                  SALE 142
                                                                            EASTERN
                       WESTERN
                       SALE 143











                           -7













                         U.S. Department of the Interior
                         Minerals Management Service
             AM          Gulf of Mexico OCS Region







                                                                                               OCS EIS/EA
                                                                                               MMS 92-OW7
              Gulf of Mexico
              Sales 142 and 143:


              Central and Western Planning Areas


              Draft Environmental Impact Statement


              Volume II: Sections IV.D. through IX







              Author


              Minerals Management Service
              Gulf of Mexico OCS Region




                                                     U  S  DEPARTMENT OF COMMERCE NOAA
                                                     COASTAL SERVICES CENTER
                                                     2234 SOUTH HOBSON AVENUE
                                                     CHARLESTON , SC 29405-2413







                                                      Property of CSC Library










              Published by

              U.S. Department of the Interior
              Minerals Management Service                                                  New Orleans
              Gulf of Mexico OCS Region                                                    April 1992
























                                                 REGIONAL DIRECIrOWS NOTE






                                     This Draft Environmental impact Statement (EIS) covering the proposed
                                 OCS oil and gas lease sales in the Gulf of Mexico for 1993 is a product of
                                 the Minerals Management Service (MMS) in New Orleans, Louisiana. The
                                 proposed sales are Central Gulf of Mexico Sale 142 (March 1993) and
                                 Western Gulf of Mexico Sale 143 (August 1993). This document includes
                                 the purpose and background of the proposed actions, the alternatives, the
                                 description of the affected environment, and the potential environmental
                                 impacts of the proposed actions and alternatives. Mitigating measures and
                                 their effects and potential cumulative impacts are also discussed. Most of
                                 the visuals that are referred to in this document were distributed with the
                                 Draft EIS for Sales 131, 135, and 137. Visual No. 2, Areas of Multiple Use,
                                 was revised and was distributed with the Draft EIS for Sales 139 and 141.
                                     Additional copies of this Draft EIS and the referenced visuals may be
                                 obtained from the MMS, Gulf of Mexico OCS Region, 1201 Elmwood Park
                                 Boulevard, New Orleans, Louisiana 70123-2394, Attention: MS 5034, or by
                                 telephone (504) 736-2519.
                                     Comments on this Draft EIS should be sent to the same address,
                                 Attention: MS 5410.
                                                                       JyRogleP4ear              14
                                                                       Regional Director
                                                                       Minerals Management Service
                                                                       Gulf of Mexico OCS Region












                                                                                                                v








                                                     COVER SHEET

                                   Environmental Impact Statement for Proposed Central Gulf of
                                     Mexico OCS Lease Sale 142 (March 1993) and Proposed
                                    Western Gulf of Mexico OCS Lease Sale 143 (August 1993)

                      Draft (x)                             Final

              Type of Action:

                      Administrative (x)            Legislative

              Area of Potential Impact:

                      Offshore Marine Environment and Coastal Counties/Parishes of Alabama, Mississippi, Louisiana, and
                      Texas


              Lead Agenc)r

                      Send Comments To:


                      U.S. Department of the Interior
                      Minerals Management Service
                      Gulf of Mexico OCS Region
                      1201 Elmwood Park Boulevard
                      New Orleans, LA 70123-2394
                      Attention: MS 5410


              Region Contact:

                      Dennis L. Chew
                      (504) 736-2793 or (FTS) 686-2793

              Washington Contact:

                      Richard H. Miller
                      U.S. Department of the Interior
                      Minerals Management Service
                      381 Elden Street (MS 4320)
                      Herndon, VA 22070-4817
                      (703) 787-1665 or (FTS) 393-1665










                                                                                                                                        vii



                  TABLE OF CONTENTS



                  FIGURES                                                                                                               xxi

                  TABLES                                                                                                                xxiii


                  ABBREVIATIONS AND ACRONYMS                                                                                            xxv


                  SUMMARY                                                                                                               xxiX


                                                                        VOLUMEI


                  1.       THE PROPOSED ACTIONS                                                                                         1-3

                           A.        PURPOSE, NEED, AND DESCRIPTION                                                                     1-3

                            B.       BACKGROUND                                                                                         1-7

                                     1.       Administrative Events Leading to the Proposed Actions                                     1-7

                                     2.       Scoping Activities and Findings                                                           1-8
                                              a.        Alternatives                                                                    1-8
                                                        (1)      Alternatives for Proposed Central Gulf Sale 142                        1-8
                                                        (2)      Alternatives for Proposed Western Gulf Sale 143                        1-8
                                                        (3)      Alternatives Considered But Not Offered                                1-8
                                              b.        Mitigating Measures                                                             1-9
                                                        (1)      Potential Mitigating Measures Analyzed in the EIS                      1-9
                                                        (2)      Mitigating Measures Considered But Not Analyzed                        1-10
                                              C.        Issues                                                                          1-11
                                                        (1)      Significant Issues                                                     1-11
                                                        (2)      Issues Considered But Not Analyzed                                     1-12

                                     3.       Regulatory and Administrative Framework                                                   1-12
                                              a.        Outer Continental Shelf Lands Act                                               1-12
                                              b.        National Environmental Policy Act                                               1-13
                                              C.        Presale Activities                                                              1-14
                                                        (1)      Federal/State Coordination                                             1-14
                                                        (2)      Geological and Geophysical Exploration
                                                                 Regulations/Coordination                                               1-15
                                              d.        Postsale Activities                                                             1-16
                                                        (1)      Review, Coordination, and Approval of
                                                                 Exploration, Development, and Production
                                                                 Activities                                                             1-16
                                                                 (a)       Exploration Plans                                            1-16
                                                                 (b)       Development and Production Plans                             1-17
                                                                 (c)       Oil Spill Contingency Plans                                  1-18
                                                                 (d)       Hydrogen Sulfide Contingency Plans                           1-18










                 viii


                                                                   (e)       Environmental Information                                       1-18
                                                                   (f)       Air Emissions Information                                       1-19
                                                                   (g)       Site Clearance                                                  1-20
                                                                   (h)       Coastal Zone Management Consistency Review
                                                                             and Appeals for Plans                                           1-20
                                                                   Enforcement Measures                                                      1-21
                                                                   (a)       Inspections                                                     1-21
                                                                   (b)       Suspension of Operations                                        1-22
                                                                   (c)       Cancellation of Leases                                          1-22
                                                                   (d)       Remedies and Penalties                                          1-23
                                                         (3)       Environmental Safeguards                                                  1-23
                                                                   (a)       OCS Regulations                                                 1-23
                                                                   (b)       OCS Structures and Equipment                                    1-24
                                                                   (c)       Lease Stipulations                                              1-26
                                                                   (d)       Other MMS Environmental Safety Controh;                         1-26
                                                                   (e)       Prevention and Control Regulations for
                                                                             Spills and Discharges                                           1-27
                                                                   (f)       Federal Compensation for Damages or Pollution                   1-32

                                    4.        Interrelationship with Other Federal Policies Governing OCS
                                              Environmental Resources                                                                        1-34
                                              a.         Ports and Waterways Safety Act                                                      1-34
                                              b.         Archaeological Resources Legislation                                                1-35
                                              C.         Endangered Species Act of 1973                                                      1-35
                                              d.         Marine Mammal Protection Act of 1972                                                1-35
                                              e.         Magnuson Fishery Conservation and Management
                                                         Act of 1976                                                                         1-37
                                              f.         National Fishing Enhancement Act of 1984                                            1-37
                                              9.         Executive Order 11990 (May 24, 1977), Protection of
                                                         Wetlands                                                                            1-37
                                              h.         Marine and Estuarine Sanctuaries Legislation                                        1-38
                                              i.         Ocean Dumping                                                                       1-42
                                              j.         Rivers and Harbors Act of 1899                                                      1-42
                                              k.         Coastal Barrier Resources Act of 1982                                               1-42
                                              1.         National Ocean Pollution Planning Act of 1978                                       1-42
                                              In.        Coastal Zone Management Act of 1972                                                 1-42

                                    5.        Gulf of Mexico Regional Environmental Studies Program                                          1-44

                Ii.       ALTERNATIVES INCLUDING THE PROPOSED ACTIONS                                                                        11-3


                          A.        PROPOSED CENTRAL GULF SALE 142                                                                           11-3


                                    1.        Alternative A - The Proposed Action                                                            11-3
                                              a.         Description                                                                         11-3
                                              b.         Summary of Impacts                                                                  11-5
                                              C.         Mitigating Measures                                                               11-14
                                                         (1)       Topographic Features Stipulation                                        11-14
                                                         (2)       Live Bottom (Pinnacle Trend) Stipulation                                11-17
                                                         (3)       Archaeological Resource Stipulation                                     11-18
                                                         (4)       Military Areas Stipulation                                              11-20
                                                         (5)       Notices to Lessees and Letters to Lessees                               11-22












                                                                                                                                                 ix

                                         2.        Alternative B - The Proposed Action Excluding the Blocks
                                                   Near Biologically Sensitive Topographic Features                                           11-23
                                                   a.      Description                                                                        11-23
                                                   b.      Summary of Impacts                                                                 11-28

                                         3.        Alternative C - No Action                                                                  11-30
                                                   a.      Description                                                                        11-30
                                                   b.      Summary of Impacts                                                                 11-30

                                         4.        Comparison of Alternatives                                                                 11-31

                             B.          PROPOSED WESTERN GULF SALE 143                                                                       11-31

                                         1.        Alternative A - The Proposed Action                                                        11-31
                                                   a.      Description                                                                        11-31
                                                   b.      Summary of Impacts                                                                 11-33
                                                   C.      Mitigating Measures                                                                11-41
                                                           (1)      Topographic Features Stipulation                                          11-41
                                                           (2)      Archaeological Resource Stipulation                                       11-45
                                                           (3)      Military Areas Stipulation                                                11-47
                                                           (4)      Notices to Lessees and Letters to Lessees                                 11-48

                                         2.        Alternative B - The Proposed Action Excluding the Blocks
                                                   Near Biologically Sensitive Topographic Features                                           11-48
                                                   a.      Description                                                                        11-48
                                                   b.      Summary of Impacts                                                                 11-53

                                         3.        Alternative C - The Proposed Action Excluding the Western
                                                   Naval Operations Area                                                                      11-55
                                                   a.      Description                                                                        11-55
                                                   b.      Summary of Impacts                                                                 11-56

                                         4.        Alternative D - No Action                                                                  11-58
                                                   a.      Description                                                                        11-58
                                                   b.      Summary of Impacts                                                                 11-58

                                         5.        Comparison of Alternatives                                                                 11-59

                              DESCRIPTION OF THE AFFECTED ENVIRONMENT                                                                         111-3


                              A.         PHYSICAL ELEMENTS OF THE ENVIRONMENT                                                                 111-3

                                         1.        Geology                                                                                    111-3

                                         2.        Meteorological Conditions                                                                  111-5

                                         3.        Air Quality                                                                                111-10

                                         4.        Physical Oceanography                                                                      111-14

                                         5.        Chemical Oceanography                                                                      111-18












                 x

                                      6.       Water Quality                                                                         111-24
                                               a.      Offshore                                                                      111-24
                                               b.      Coastal and Nearshore                                                         111-25


                          B.          BIOLOGICAL RESOURCES                                                                           111-28


                                      1.       Sensitive Coastal Environments                                                        111-28
                                               a.      Barrier Beaches                                                               111-28
                                               b.      Wetlands                                                                      111-31


                                      2.       Sensitive Offshore Resources                                                          111-34
                                               a.      Live Bottoms (Pinnacle Trend)                                                 111-37
                                               b.      Deep-water Benthic Communities                                                111-39
                                               C.      Topographic Features                                                          111-41

                                      3.       Terrestrial and Marine Mammals                                                        111-49
                                               a.      Marine Mammals                                                                111-49
                                                       (1)      Nonendangered and Nonthreatened Species                              111-49
                                                       (2)      Endangered and Threatened Species                                    111-52
                                               b.      Alabama, Choctawhatchee, and Perdido Key Beach Mice                           111-52

                                      4.       Marine Turtles                                                                        111-53


                                      5.       Coastal and Marine Birds                                                              111-54
                                               a.      Nonendangered and Nonthreatened Species                                       111-54
                                               b.      Endangered and Threatened Species                                             111-55

                                      6.       Fish Resources                                                                        111-56
                                               a.      Nonendangered and Nonthreatened Species                                       111-56
                                               b.      Gulf Sturgeon                                                                 111-60

                          C.          OTHER RELEVANT ACTIVITIES AND RESOURCES                                                        111-60


                                      1.       OCS Oil and Gas Industry                                                              111-60

                                      2.       Socioeconomic Conditions                                                              111-64
                                               a.      Population, Labor, and Employment                                             111-64
                                               b       Public Services and Infrastructure                                            111-73
                                               C.      Social Patterns                                                               111-76


                                      3.       Commercial Fisheries                                                                  111-77


                                      4.       Recreational Resources and Activities                                                 111-80


                                      5.       Archaeological Resources                                                              111-83
                                               a.      Historic                                                                      111-83
                                               b.      Prehistoric                                                                   111-83


                                      6.       Coastal Zone Management Plans                                                         111-85











                                                                                                                                xi

                IV.     ENVIRONMENTAL CONSEQUENCES                                                                          IV-3

                        A. PROPOSED ACTION SCENARIO                                                                         IV-3

                                 1.       Resource Estimates, Timetables, and Subarea Descriptions                          IV-3

                                 2.       Description of Offshore Operations and Impacting Factors                          IV-9
                                          a.       Offshore Infrastructure Activities                                       IV-9
                                                   (1)     Surveying/Seismic Operations                                     IV-9
                                                   (2)     Drilling Rigs and Platforms                                     IV-10
                                                           (a) Exploration and Delineation Phase                           IV-10
                                                           (b) Development Phase                                           IV-11
                                                           (c) Production Phase                                            IV-11
                                                   (3)     Structure Removals                                              IV-12
                                                           Workover/Abandonment Activities
                                                   (4)     Deep-water Activities                                           IV-13
                                          b.       Offshore Transport of Oil and Gas                                       IV-15
                                                   (1)     Pipelines                                                       IV-15
                                                   (2)     Oil Barges                                                      IV-20
                                                   (3)     Shuttle Tankers                                                 IV-21
                                          C.       Offshore Transport of Personnel/Supplies                                IV-22
                                                   (1)     Service Vessels                                                 IV-22
                                                   (2)     Helicopters                                                     IV-23
                                          d.       Offshore Impacting Factors Related to the
                                                   Proposed Actions                                                        IV-23
                                                   (1)     Bottom Disturbances                                             IV-23
                                                           (a)       Fixed Structures                                      IV-24
                                                           (b)       Anchoring                                             IV-24
                                                   (2)     Bottom Debris                                                   IV-25
                                                   (3)     Space-Use Conflicts                                             IV-26
                                                   (4)     Aesthetic Interference                                          IV-26
                                                   (5)     Offshore Operational Wastes                                     IV-26
                                                           (a)       Drilling Muds and Cuttings                            IV-29
                                                           (b)       Produced Waters                                       IV-30
                                                           (c)       Other Development/
                                                                     Production Fluids                                     IV-31
                                                           (d)       Production Sands/Solids/Equipment                     IV-32
                                                           (e)       Treated Domestic and Sanitary Wastes                  IV-33
                                                           (f)       Other Trash and Debris                                IV-33
                                                   (6)     Air Emissions                                                   IV-34
                                                   (7)     Noise                                                           IV-35
                                                   (8)     Blowouts                                                        IV-36
                                                   (9)     Offshore Spills                                                 IV-37

                                 3.       Description of Onshore/Coastal Operations and Impacting Factors                  IV-37
                                          a.       Onshore Infrastructure                                                  IV-38
                                                   (1)     Service and Construction Facilities                             IV-38
                                                           (a)       Service Bases                                         IV-38
                                                           (b)       Heliports                                             IV-39
                                                           (c)       Pipeyards                                             IV-39
                                                           (d)       Fabrication Yards                                     IV-39










                 xii

                                                    (2)     Processing and Storage Facilities                               IV40
                                                            (a)      Oil Refineries                                         IV40
                                                            (b)      Gas Processing Plants                                  IV41
                                                            (c)      Separation Facilities                                  IV41
                                                            (d)      Terminals                                              IV42
                                           b.       Landings and Coastal Transport Operations                               IV43
                                                    (1)     Pipelines                                                       IV43
                                                    (2)     Oil Barges                                                      IV43
                                                    (3)     Shuttle Tankers                                                 IV-44
                                                    (4)     Navigation Channels                                             IV44
                                           C.       Onshore/Coastal Impacting Factors Related to the Proposed
                                                    Actions                                                                 IV-44
                                                    (1)     Disturbances from Use of Existing Infrastructure                IV44
                                                            (a)      Nonpoint Source Discharges                             IV-45
                                                            (b)      Operational Discharges                                 IV-45
                                                            (c)      Air Emissions                                          IV46
                                                    (2)     Disturbances from New Infrastructure Emplacement                IV46
                                                    (3)     Vessel Usage of Navigation Channels                             IV46
                                                            (a)      Channel Back Erosion                                   IV46
                                                            (b)      Vessel Operational Discharges                          IV47
                                                            (c)      Maintenance/New Dredging                               IV-47
                                                    (4)     Onshore/Coastal Disposal of Offshore Oil and Gas
                                                            Industry Operational Wastes                                     IV48
                                                            (a)      Produced Waters                                        IV-50
                                                            (b)      Production and Drilling Solids                         IV-51
                                                            (c)      Other Solid Wastes                                     IV-51
                                                    (5)     Onshore/Coastal Spills                                          IV-52

                         B.       CUMULATIVE SCENARIO                                                                       IV-52


                                 1.        EXPLORATION, DEVELOPMENT, AND PRODUCTION SCENARIO
                                           AND ASSUMPTIONS FOR THE OCS LEASING PROGRAM                                      IV-52


                                           a.       Resource Estimates and Timetables                                       IV-52
                                           b.       Description of Offshore Operations and Impacting Factors                IV-53
                                                    (1)     Offshore Infrastructure and Activities                          IV-53
                                                            (a)      Surveying/Seismic Operations                           IV-53
                                                            (b)      Drilling Rigs and Platforms                            IV-53
                                                            (c)      Structure Removals                                     IV-57
                                                            (d)      Workover/Abandonment Activities                        IV-57
                                                    (2)     Offshore Transport of Oil and Gas                               IV-58
                                                    (3)     Offshore Transport of Personnel/Supplies                        IV-60
                                                    (4)     Offshore Impacting Factors Related to Future
                                                            OCS Operations                                                  IV-61
                                                            (a)      Bottom Disturbances                                    IV-61
                                                            (b)      Bottom Debris                                          IV-62
                                                            (c)      Space-Use Conflicts                                    IV-62
                                                            (d)      Aesthetic Interference                                 IV-63
                                                            (e)      Offshore Operational Wastes                            IV-63
                                                            (f)      Air Emissions                                          IV-66
                                                            (g)      Noise                                                  IV-66
                                                            (h)      Blowouts                                               IV-66
                                                            (i)      Offshore Spills                                        IV-67











                                                                                                                                    xiii

                                            C.       Description of Onshore/Coastal Operations and Impacting Factors             IV-67
                                                     (1)      Onshore Infrastructure and Activities                              IV-67
                                                              (a)      Service and Construction Facilities                       IV-67
                                                              (b)      Processing and Storage Facilities                         IV-72
                                                     (2)      Landings and Coastal Transport Operations                          IV-73
                                                     (3)      Onshore/Coastal Impacting Factors Related to
                                                              OCS Activities                                                     IV-75
                                                              (a)      Disturbances from the Use of the Existing and New
                                                                       Infrastructure                                            IV-75
                                                              (b)      Vessel Usage of Navigation Channels                       IV-78
                                                              (c)      Onshore/Coastal Disposal of Offshore Wastes               IV-78
                                                              (d)      Onshore/Coastal Spills                                    IV-81


                                   2.       State Oil and Gas Activities                                                         IV-82
                                            a.       Leasing, Production, and Associated Infrastructure                          IV-82
                                            b.       Related Concerns                                                            IV-82
                                                     (1)      Drilling-Related Wastes                                            IV-82
                                                     (2)      Production-Related Wastes                                          IV-83

                                   3.       Other Major Offshore Activities                                                      IV-85
                                            a.       Ocean Dumping                                                               IV-85
                                            b.       Deep-water Ports                                                            IV-86
                                            C.       Non-energy Minerals Program in the Gulf of Mexico                           IV-86
                                            d.       Marine Transportation                                                       IV-87
                                            e.       Military Activities                                                         IV-88

                                   4.       Other Major Onshore/Coastal Activities                                               IV-89
                                            a.       River Development and Flood Control Projects                                IV-89
                                            b.       Submergence and Natural Subsidence of Wetlands                              IV-90
                                            C.       Contributors to Coastal Water Quality Problems                              IV-90

                                   5.       Activities Outside the Planning Areas Affecting Migratory Species                    IV-91
                                            a.       Coastal and Marine Birds                                                    IV-91
                                            b.       Marine Turtles                                                              IV-92
                                            C.       Cetaceans                                                                   IV-93
                                            d.       Fish Resources                                                              IV-93


                                   6.       Major Sources of Oil Contamination in the Gulf of Mexico                             IV-94
                                            a.       Other Sources of Oil Spills                                                 IV-94
                                            b.       Operational Discharges                                                      IV-98
                                            C.       Other                                                                       IV-98


                          C.       OIL SPILLS OCCURRING IN CONNECTION WITH OCS OPERATIONS                                        IV-99

                                   1.       Historical Spill Occurrence and Assumptions                                        IV-100

                                   2.       Characteristics, Fates, and Effects                                                IV-106

                                   3.       Results of Oil Spill Risk Analysis                                                 IV-112

                                   4.       Oil Spill Prevention                                                               IV-127











                 xiv

                                   5.       Oil Spill Contingency Planning and Response                                          IV-130
                                            a.        Responsibility and Authority                                               IV-130
                                            b.        Oil Spill Contingency Planning                                             IV-130
                                            C.        Spill Response Training/Drills                                             IV-133
                                            d.        Equipment Response and Capability                                          IV-134
                                                      (1)      Equipment Locations                                               IV-134
                                                      (2)      Equipment/Response Options and Effectiveness                      IV-138
                                                               (a)      Mechanical Equipment                                     IV-138
                                                               (b)      Chemicals/Dispersants Usage                              IV-140
                                                      (3)      Response Times                                                    IV-143
                                                      (4)      Offshore Cleanup Capability for Handling Various
                                                               Size Spills                                                       IV-144
                                                      (5)      Coastal Cleanup Techniques and Effects                            IV-145
                                                      (6)      In Situ Burning                                                   IV-150
                                                      (7)      Bioremediation                                                    IV-151
                                            e.        Response Options for Handling Oiled Wildlife and Birds                     IV-152
                                            f.        Recent Developments in Spill-Response Planning/Capabilities                IV-153

                                                                     VOLUMEII


                         D.        ENVIRONMENTAL IMPACTS OF THE PROPOSED ACTIONS AND
                                   ALTERNATIVES                                                                                  IV-159


                                   1.       PROPOSED CENTRAL GULF SALE 142                                                       IV-159
                                            a.        Alternative A - The Proposed Action                                        IV-159
                                                      (1)      Impacts on Sensitive Coastal Environments                         IV-159
                                                               (a)      Coastal Barrier Beaches                                  IV-159
                                                               (b)      Wetlands                                                 IV-164
                                                      (2)      Impacts on Sensitive Offshore Resources                           IV-171
                                                               (a)      Live Bottoms (Pinnacle Trend)                            IV-171
                                                               (b)      Deep-water Benthic Communities                           IV-175
                                                               (c)      Topographic Features                                     IV-178
                                                      (3)      Impacts on Water Quality                                          IV-185
                                                      (4)      Impacts on Air Quality                                            IV-197
                                                      (5)      Impacts on Coastal and Marine Mammals                             IV-207
                                                               (a)      Marine Mammals                                           IV-207
                                                               (b)      Alabama, Choctawhatchee, and Perdido Key
                                                                        Beach Mice                                               IV-215
                                                      (6)      Impacts on Marine Turtles                                         IV-217
                                                      (7)      Impacts on Coastal and Marine Birds                               IV-222
                                                               (a)      Nonendangered and Nonthreatened Species                  IV-223
                                                               (b)      Endangered and Threatened Species                        IV-227
                                                      (8)      Impacts on the Gulf Sturgeon                                      IV-230
                                                      (9)      Impacts on Commercial Fisheries                                   IV-232
                                                      (10)     Impacts on Recreational Resources and Activities                  IV-237
                                                               (a)      Beach Use                                                IV-237
                                                               (b)      Marine Fishing                                           IV-240
                                                      (11)     Impacts on Archaeological Resources                               IV-243
                                                               (a)      Historic                                                 IV-244
                                                               (b)      Prehistoric                                              IV-248












                                                                                                                                xv

                                                    (12)    Impacts on Socioeconomic Conditions                            IV-252
                                                            (a)      Population, Labor, and Employment                     IV-252
                                                            (b)      Public Services and Infrastructure                    IV-262
                                                            (c)      Social Patterns                                       IV-266

                                          b.        Alternative B - The Proposed Action Excluding the Blocks
                                                    Near Biologically Sensitive Topographic Features                       IV-270
                                                    (1)     Impacts on Sensitive Coastal Environments                      IV-271
                                                            (a)      Coastal Barrier Beaches                               IV-271
                                                            (b)      Wetlands                                              IV-271
                                                    (2)     Impacts on Sensitive Offshore Resources                        IV-272
                                                            (a)      Live Bottoms (Pinnacle Trend)                         IV-272
                                                            (b)      Deep-water Benthic Communities                        IV-273
                                                            (c)      Topographic Features                                  IV-274
                                                    (3)     Impacts on Water Quality                                       IV-275
                                                    (4)     Impacts on Air Quality                                         IV-276
                                                    (5)     Impacts on Coastal and Marine Mammals                          IV-277
                                                            (a)      Marine Mammals                                        IV-277
                                                            (b)      Alabama, Choctawhatchee, and Perdido Key
                                                                     Beach Mice                                            IV-278
                                                    (6)     Impacts on Marine Turtles                                      IV-278
                                                    (7)     Impacts on Coastal and Marine Birds                            IV-278
                                                            (a)      Nonendangered and Nonthreatened Species               IV-278
                                                            (b)      Endangered and Threatened Species                     IV-279
                                                    (8)     Impacts on the Gulf Sturgeon                                   IV-279
                                                    (9)     Impacts on Commercial Fisheries                                IV-280
                                                    (10)    Impacts on Recreational Resources and Activities               IV-280
                                                            (a)      Beach Use                                             IV-280
                                                            (b)      Marine Fishing                                        IV-280
                                                    (11)    Impacts on Archaeological Resources                            IV-281
                                                            (a)      Historic                                              IV-281
                                                            (b)      Prehistoric                                           IV-282
                                                    (12)    Impacts on Socioeconomic Conditions                            IV-282
                                                            (a)      Population, Labor, and Employment                     IV-282
                                                            (b)      Public Services and Infrastructure                    IV-283
                                                            (c)      Social Patterns                                       IV-283
                                           C.       Impacts from Alternative C - No Action                                 IV-283
                                           d.       Impacts of Cumulative Actions                                          IV-284
                                                    (1)     Impacts on Sensitive Coastal Environments                      IV-284
                                                            (a)      Coastal Barrier Beaches                               IV-284
                                                            (b)      Wetlands                                              IV-288
                                                    (2)     Impacts on Sensitive Offshore Resources                        IV-294
                                                            (a)      Live Bottoms (Pinnacle Trend)                         IV-294
                                                            (b)      Deep-water Benthic Communities                        IV-297
                                                            (c)      Topographic Features                                  IV-298
                                                    (3)     Impacts on Water Quality                                       IV-301
                                                    (4)     Impacts on Air Quality                                         IV-309
                                                    (5)     Impacts on Coastal and Marine Mammals                          IV-314
                                                            (a)      Marine Mammals                                        IV-314
                                                            (b)      Alabama, Choctawhatchee, and Perdido Key
                                                                     Beach Mice                                            IV-319
                                                    (6)     Impacts on Marine Turtles                                      IV-320










                 xvi

                                                    (7)      Impacts on Coastal and Marinc Birds                           IV-324
                                                             (a)     Nonendangered and Nonthreatened Species               IV-324
                                                             (b)     Endangered and Threatened Species                     IV-326
                                                    (8)      Impacts on the Gulf Sturgeon                                  IV-328
                                                    (9)      Impacts on Commercial Fisheries                               IV-330
                                                    (10)     Impacts on Recreational Resources and Activities              IV-332
                                                             (a)     Beach Use                                             IV-332
                                                             (b)     Marine Fishing                                        IV-334
                                                    (11)     Impacts on Archaeological Resources                           IV-335
                                                             (a)     Historic                                              IV-336
                                                             (b)     Prehistoric                                           IV-338
                                                    (12)     Impacts on Socioeconomic Conditions                           IV-340
                                                             (a)     Population, Labor, and Employment                     IV-340
                                                             (b)     Public Services and Infrastructure                    IV-346
                                                             (c)     Social Patterns                                       IV-348
                                           e.       Coastal Zone Management Plans and Land Use                             IV-352

                                  2.       PROPOSED WESTERN GULF SALE 143                                                  IV-374
                                           a.       Alternative A - The Proposed Action                                    IV-374
                                                    (1)      Impacts on Sensitive Coastal Environments                     IV-375
                                                             (a)     Coastal Barrier Beaches                               IV-375
                                                             (b)     Wetlands                                              IV-378
                                                    (2)      Impacts on Sensitive Offshore Resources                       IV-384
                                                             (a)     Deep-water Benthic Communities                        IV-384
                                                             (b)     Topographic Features                                  IV-386
                                                    (3)      Impacts on Water Quality                                      IV-389
                                                    (4)      Impacts on Air Quality                                        IV400
                                                    (5)      Impacts on Marine Mammals                                     IV-409
                                                             (a)     Nonendangered and Nonthreatened Species               IV-409
                                                             (b)     Endangered and Threatened Species                     IV414
                                                    (6)      Impacts on Marine Turtles                                     IV417
                                                    (7)      Impacts on Coastal and Marine Birds                           IV422
                                                             (a)     Nonendangered. and Nonthreatened Species              IV422
                                                             (b)     Endangered and Threatened Species                     IV426
                                                    (8)      Impacts on Commercial Fisheries                               IV-429
                                                    (9)      Impacts on Recreational Resources and Activities              IV433
                                                             (a)     Beach Use                                             IV433
                                                             (b)     Marine Fishing                                        IV435
                                                    (10)     Impacts on Archaeological Resources                           IV436
                                                             (a)     Historic                                              IV437
                                                             (b)     Prehistoric                                           IV441
                                                    (11)     Impacts on Socioeconomic Conditions                           IV-444
                                                             (a)     Population, Labor, and Employment                     IV444
                                                             (b)     Public Services and Infrastructure                    IV454
                                                             (c)     Social Patterns                                       IV-458
                                           b.       Alternative B - The Proposed Action Excluding the Blocks
                                                    Near Biologically Sensitive Topographic Features                       IV-463
                                                    (1)      Impacts on Sensitive Coastal Environments                     IV-464
                                                             (a)     Coastal Barrier Beaches                               IV-464
                                                             (b)     Wetlands                                              IV464
                                                    (2)      Impacts on Sensitive Offshore Resources                       IV465
                                                             (a)     Deep-water Benthic Communities                        IV-465
                                                             (b)     Topographic Features                                  IV-465











                                                                                                                               xvii

                                                    (3)      Impacts on Water Quality                                      IV-466
                                                    (4)      impacts on Air Quality                                        IV-467
                                                    (5)      Impacts on Marine Mammals                                     IV-469
                                                             (a)     Nonendangered and Nonthreatened Species               IV-469
                                                             (b)     Endangered and Threatened Species                     IV-469
                                                    (6)      Impacts on Marine Turtles                                     IV-470
                                                    (7)      Impacts on Coastal and Marine Birds                           IV-470
                                                             (a)     Nonendangered and Nonthreatened Species               IV-470
                                                             (b)     Endangered and Threatened Species                     IV-470
                                                    (8)      Impacts on Commercial Fisheries                               IV-471
                                                    (9)      Impacts on Recreational Resources and Activities              IV-471
                                                             (a)     Beach Use                                             IV-471
                                                             (b)     Marine Fishing                                        IV-472
                                                    (10)     Impacts on Archaeological Resources                           IV-472
                                                             (a)     Historic                                              IV472
                                                             (b)     Prehistoric                                           IV473
                                                    (11)     Impacts on Socioeconomic Conditions                           IV473
                                                             (a)     Population, Labor, and Employment                     IV-473
                                                             (b)     Public Services and Infrastructure                    IV474
                                                             (c)     Social Patterns                                       IV-474
                                           C.       Alternative C - The Proposed Action Excluding the Western
                                                    Naval Operations Area                                                  IV475
                                                    (1)      Impacts on Scnsitive Coastal Environments                     IV475
                                                             (a)     Coastal Barrier Beaches                               IV-475
                                                             (b)     Wetlands                                              IV-476
                                                    (2)      Impacts on Sensitive Offshore Resources                       IV-476
                                                             (a)     Deep-water Benthic Communities                        IV-476
                                                             (b)     Topographic Features                                  IV-477
                                                    (3)      Impacts on Water Quality                                      IV-477
                                                    (4)      Impacts on Air Quality                                        IV-478
                                                    (5)      Impacts on Marine Mammals                                     IV-479
                                                             (a)     Nonendangered and Nonthreatened Species               IV-479
                                                             (b)     Endangered and Threatened Species                     IV-479
                                                    (6)      Impacts on Marine Turtles                                     IV-480
                                                    (7)      Impacts on Coastal and Marine Birds                           IV-480
                                                             (a)     Nonendangered and Nonthreatened Species               IV-480
                                                             (b)     Endangered and Threatened Species                     IV-480
                                                    (8)      Impacts on Commercial Fisheries                               IV-481
                                                    (9)      Impacts on Recreational Resources and Activities              IV-481
                                                             (a)     Beach Use                                             IV-481
                                                             (b)     Marine Fishing                                        IV-481
                                                    (10)     Impacts on Archaeological Resources                           IV-482
                                                             (a)     Historic                                              IV-482
                                                             (b)     Prehistoric                                           IV-482
                                                    (11)     Impacts on Socioeconomic Conditions                           IV-483
                                                             (a)     Population, Labor, and Employment                     IV-483
                                                             (b)     Public Services and Infrastructure                    IV-483
                                                             (c)     Social Patterns                                       IV-484
                                           d.       Impacts from Alternative D - No Action                                 IV-484
                                           C.       Impacts of Cumulative Actions                                          IV-485
                                                    (1)      Impacts on Sensitive Coastal Environments                     IV-485
                                                             (a)     Coastal Barrier Beaches                               IV-485
                                                             (b)     Wetlands                                              IV-488











                xviii


                                                   (2)     Impacts on Sensitive Offshore Resources                       IV-491
                                                           (a)      Deep-water Benthic Communities                       IV-491
                                                           (b)      Topographic Features                                 IV-492
                                                   (3)     Impacts on Water Quality                                      IV-494
                                                   (4)     Impacts on Air Quality                                        IV-499
                                                   (5)     Impacts on Marine Mammals                                     IV-504
                                                           (a)      Nonendangered and Nonthreatened Speciies             IV-504
                                                           (b)      Endangered and Threatened Species                    IV-506
                                                   (6)     Impacts on Marine Turtles                                     IV-508
                                                   (7)     Impacts on Coastal and Marine Birds                           IV-512
                                                           (a)      Nonendangered and Nonthreatened Species              IV-512
                                                           (b)      Endangered and Threatened Species                    IV-514
                                                   (8)     Impacts on Commercial Fisheries                               IV-517
                                                   (9)     Impacts on Recreational Resources and Activities              IV-519
                                                           (a)      Beach Use                                            IV-519
                                                           (b)      Marine Fishing                                       IV-521
                                                   (10)    Impacts on Archaeological Resources                           IV-522
                                                           (a)      Historic                                             IV-522
                                                           (b)      Prehistoric                                          IV-514
                                                   (11)    Impacts on Socioeconomic Conditions                           IV-526
                                                           (a)      Population, Labor, and Employment                    IV-526
                                                           (b)      Public Services and Infrastructure                   IV-530
                                                           (c)      Social Patterns                                      IV-532
                                          f.       Coastal Zone Management Plans and Land Use                            IV-534

                        E. ANALYSIS OF A LARGE OIL SPILL                                                                 IV-546


                                 1.       Background                                                                     IV-546

                                 2.       Scenario to be Analyzed                                                        IV-546
                                          a.       Assumptions About the Occurrence of the Spill                         IV-546
                                          b.       Assumptions About the Offshore and Shoreline Zone of Contact          IV-546
                                          C.       Assumptions About the Onshore Zone of Contact                         IV-546
                                          d.       Assumptions About the Fate of the Spilled Oil                         IV-546

                                 3.       Effects of a Large Oil Spill                                                   IV-548
                                          a.       Impacts on Sensitive Coastal Habitats                                 IV-548
                                          b.       Impacts on Water Quality                                              IV-549
                                          C.       Impacts on Air Quality                                                IV-551
                                          d.       Impacts on Endangered and Threatened Species                          IV-552
                                          e.       Impacts on Marine Mammals                                             IV-554
                                          f.       Impacts on Coastal and Marine Birds                                   IV-554
                                          9.       Impacts on Commercial Fisheries                                       IV-555
                                          h.       Impacts on Recreational Resources and Activities                      IV-556

               V.       CONSULTATION AND COORDINATION                                                                       V-3


                        A.       DEVELOPMENT OF THE PROPOSED ACTIONS                                                        V-3


                        B.       DEVELOPMENT OF THE DRAFT EIS                                                               V-3


                        C.       RESPONSES TO THE CALL FOR INFORMATION AND THE
                                 NOTICE OF INTENT TO PREPARE AN EIS                                                         V-3











                                                                                                               xix

                     D.      DISTRIBUTION OF THE DRAFT EIS FOR REVIEW AND
                             COMMENT                                                                           V-6


             vi.     BIBLIOGRAPHY AND SPECIAL REFERENCES                                                      VI-3


             VII.    PREPARERS                                                                                VI-3


             VIII.   GLOSSARY                                                                                 VI-3


             ix.     APPENDICES


                     A-      BLOCKS AFFECTED BY THE TOPOGRAPHIC FEATURES
                             STIPULATIONS IN THE CENTRAL AND WESTERN GULF
                             OF MEXICO                                                                         A-3


                     B.      BIOLOGICAL OPINIONS                                                               B-3


                     C.      RESOURCE ESTIMATES GUIDELINES                                                     C-3


                     D.      ALTERNATIVE ENERGY RESOURCES                                                      D-3


                     E.      RECENT MITIGATING MEASURES                                                        E-3










                                                                                                                                         Xxi

                  FIGURES
                                                                                                                                      Page

                  Figure I-1         Central and Western Gulf Planning Areas, Indicating Deferred Areas and
                                       Areas Affected by Alternatives                                                                    14
                  Figure 11-1        Location and Lease Status of Blocks Affected by Alternative B                                    11-24
                                       (West Louisiana)
                  Figure 11-2        Location and Lease Status of Blocks Affected by Alternative B                                    11-25
                                       (East Louisiana)
                  Figure 11-3        Location and Lease Status of Blocks Affected by Alternative B                                    11-49
                                       (South Texas)
                  Figure 11-4        Location and Lease Status of Blocks Affected by Alternative B                                    11-50
                                       (North Texas)
                  Figure III-1       Status of Air Quality in the Western and Central Planning Areas of
                                       the Gulf of Mexico                                                                             111-13
                  Figure 111-2       Location and Description of Chemosynthetic Communities in the Central
                                       Gulf of Mexico                                                                                 111-42
                  Figure 111-3       Location and Description of Chemosynthetic: Communities in the
                                       Western Gulf of Mexico                                                                         111-43
                  Figure 111-4       Location of Topographic Features                                                                 111-44
                  Figure 111-5       Sonnier Bank and Protective Zones as Proposed by the Biological Lease
                                       Stipulation                                                                                    111-48
                  Figure 111-6       Mobile Rig Utilization                                                                           111-61
                  Figure 111-7       Leased Acreage                                                                                   111-62
                  Figure 111-8       Oil and Gas Wellhead Prices                                                                      111-63
                  Figure 111-9       Oil and Gas Production Offshore Louisiana and Texas, 1954 to 1990                                111-65
                  Figure III-10      Oil and Gas Production Values Offshore Louisiana and Texas, 1954 to 1990                         111-66
                  Figure IV-1        Gulf of Mexico OCS Planning Areas and Coastal and Offshore Subareas                                IV-7
                  Figure IV-2        Number of OCS Pipeline Landfalls                                                                 IV-76
                  Figure IV-3        Distribution of Produced Water Discharges in Louisiana's Estuarine Basins                        IV-84
                  Figure IV-4        Distribution of Produced Water Discharges in Texas Coastal Waters                                IV-84
                  Figure IV-5        Location of Oil Spills (greater than or equal to 1,000 bbl) from Barges and Tankers              IV-97
                                       in or near the Gulf of Mexico from 1974 to July 1990
                  Figure IV-6        Processes Affecting the Fate of Spilled Oil                                                     IV-107
                  Figure IV-7        Land Segments and Launch Sites Used in the Minerals Management Service                          IV-116
                                       Oil Spill Risk Analysis Model
                  Figure IV-8        Base Case Employment Impacts from Central Gulf Sale 142                                         IV-254
                  Fi(yure IV-9       Employment Impacts from the OCS Program (Central Planning Area)                                 IV-341
                  Figure IV-10       Base Case Employment Impacts from Western Gulf Sale 143                                         IV-447
                  Figure IV-11       Employment Impacts from the OCS Program (Western Planning Area)                                 IV-527










                                                                                                                                                           xxiii

                    TABLES

                                                                                                                                                           Page

                    Table S-1                     Oil and Gas Resource and OCS Development Activity Estimates:
                                                  Sales 142 and 143                                                                                        xxxii
                    Table S-2                     Significant Environmental Resources and Activities Analyzed                                              xxxiii
                    Table S-3                     Comparison and Summary of Impact Levels for Alternatives A-C and
                                                  Cumulative in the Central Planning Area (Sale 142)                                                       xxxvi
                    Table S4                      Comparison and Summary of Impact Levels for Alternatives A-D and
                                                  Cumulative in the Western Planning Area (Sale 143)                                                       x1iii
                    Table 11-1                    Military Contacts                                                                                        11-21
                    Table 111-1                   Climatological Data for Selected Gulf Coast Locations                                                    111-7
                    Table 111-2                   National Ambient Air Quality Standards for the Five Gulf of Mexico States,
                                                  with More Restrictive Standards Shown for the State of Florida
                    Table 111-3                   Water Mass Characteristics in the Gulf of Mexico                                                         111-20
                    Table 111-4                   Biotic Zones of Topographic Features with Bank Crest and Seafloor Depth
                                                  in Meters                                                                                                111-47
                    Table 111-5                   Marine Mammals of the Gulf of Mexico                                                                     111-50
                    Table 111-6                   Population Statistics by Offshore Subarea                                                                111-68
                    Table 111-7                   Labor Force and Unemployment Statistics for the Central and
                                                  Western Gulf Coastal Subareas (average annual data--thousands)                                           111-69
                    Table 111-8                   Industrial Composition of Central and Western Gulf Coastal
                                                  Subareas for 1987                                                                                        111-71
                    Table 111-9                   Population and Employment Projections for the Central and Western
                                                  Gulf Coastal Subareas                                                                                    111-74
                    Table 111-10                  Marine Recreational Fishing Trips in the Gulf of Mexico (1984 to 1989)                                   111-81
                    Table III-11                  Economic Activity Associated with Marine Recreational Fishing in the
                                                  Gulf of Mexico                                                                                           111-82
                    Table IV-1                    Expected Oil and Gas Production in the Gulf of Mexico Over the
                                                  Life of the Proposed Action (1993 to 2027)                                                               IV-5
                    Table IV-2                    Offshore Scenario Information Related to Sale 142 for the Years
                                                  1993 to 2027                                                                                             IV-6
                    Table IV-3                    Offshore Scenario Information Related to Sale 143 for the Years
                                                  1993 to 2027                                                                                             IV-8
                    Table IV-4                    Onshore Scenario Information Related to Sale 142 for the Years
                                                  1993 to 2027                                                                                             IV-16
                    Table IV-5                    Onshore Scenario Information Related to Sale 143 for the Years
                                                  1993 to 2027                                                                                             IV-17
                    Table IV-6                    Waterway Usage by OCS-Related Navigation Associated with Sales 142
                                                  and 143 for the Years 1993 to 2027                                                                       IV-18
                    Table IV-7                    Offshore Scenario Information Associated with OCS Program Activities in
                                                  the Central Planning Area for the Years 1993 to 2027                                                     IV-54
                    Table IV-8                    Offshore Scenario Information Associated with OCS Program Activities in
                                                  the Western Planning Area for the Years 1993 to 2027                                                     IV-55
                    Table IV-9                    Offshore Scenario Information Associated with OCS Program Activities in
                                                  the Eastern Planning Area for the Years 1993 to 20277                                                    IV-56
                    Table IV-10                   Projected New Central Gulf OCS Oil and Gas Trunklines (km) by
                                                  Water Depth                                                                                              IV-59
                    Table IV-11                   Projected New Western Gulf OCS Oil and Gas Trunklines (km) by
                                                  Water Depth                                                                                              IV-60










                 xxiv

                 Table IV-12             Onshore Scenario Information Related to OCS Program Activities in the
                                         Central Planning Area for the Years 1993 to 2027                                   IV-68
                 Table IV-13             Onshore Scenario Information Related to OCS Program Activities in the
                                         Western Planning Area for the Years 1993 to 2027                                   IV-69
                 Table IV-14             Onshore Scenario Information Related to OCS Program Activities in the
                                         Gulf of Mexico for the Years 1993 to 2027                                          IV-70
                 Table IV-15             Waterway Usage by OCS-Related Navigation Associated with the Oa;
                                         Program for the Years 1993 to 2027                                                 IV-74
                 Table IV-16             Shuttle Tanker Spill Occurrence for Major Ports Receiving OCS-Produced
                                         Crude Oil (spills greater than 1,000 bbl)                                         IV-104
                 Table IV-17             Mass Balance of a Typical Gulf of Mexico Crude Oil Spill                          IV-109
                 Table IV-18             LC50 Values for Some Gulf of Mexico Marine Animals                                IV-113
                 Table IV-19             Oil-spill Occurrence Probability Estimates for Spills Greater than or
                                         Equal to 1,000 Barrels Resulting Over the Life of the Proposed Actions,
                                         from OCS Program Activities for Proposed Sales 142 and 143                        IV-115
                 Table IV-20             Probabilities (expressed as percent chance) that an Oil Spill (greater
                                         than or equal to 1000 bbl) Starting at a Particular Location Will Contact
                                         a Certain Land Segment Within 10 Days (Sales 142 and 143)                         IV-117
                 Table IV-21             Probabilities (expressed as percent chance) of One or More Spills
                                         Greater than or Equal to 1,000 bbl, and the Estimated Number of
                                         Spills (mean) Occurring and Contacting Land Segments Over the
                                         Life of the Proposed Action Within 10 Days (Central Gulf Sale 142)                IV-120
                 Table IV-22             Probabilities (expressed as percent chance) of One or More Spills Greater
                                         than or Equal to 1,000 bbI and the Estimated Number of Spills (mean)
                                         Occurring and Contacting Land Segments Over the Life of the
                                         Proposed Action Within 10 Days (Western Gulf Sale 143)                            IV-123
                 Table IV-23             CGA's Oil Response Equipment                                                      IV-135
                 Table IV-24             Number of Oil Spill Cleanup Contractors by State Stocking Various
                                         Cleanup Equipment                                                                 IV-136
                 Table IV-25             Summary of Cleanup Methods                                                        IV-146
                 Table IV-26             Shoreline Cleanup Methods                                                         IV-147
                 Table IV-27             Base Case OCS-Related Employment Projections (Direct+ Indirect+
                                         Induced)/Central Gulf Sale 142 (person-years)                                     IV-256
                 Table IV-28             Population and Employment Impact Levels for the Base Case Scenario/
                                         Central Gulf Sale 142 (percent)                                                   IV-257
                 Table IV-29             High Case OCS-Related Employment Projections (Direct+ Indirect+
                                         Induced)/Central Gulf Sale 142 (person-years)                                     IV-259
                 Table IV-30             Population and Employment Impact Levels for the High Case Scenario/
                                         Central Gulf Sale 142 (percent)                                                   IV-260
                 Table IV-31             OCS-Related Employment Projections (Direct+ Indirect+ Induced)/
                                         for the Cumulative Case Scenario (person-years)                                   IV-343
                 Table IV-32             Population and Employment Impact Levels for the Cumulative Case
                                         Scenario (percent)                                                                I V-343
                 Table IV-33             Base Case OCS-Related Employment Projections (Direct +Indirect+
                                         Induced)/Western Gulf Sale 143 (person-years)                                     IV-448
                 Table IV-34             Population and Employment Impact Levels for the Base Case Scenario/
                                         Western Gulf Sale 143 (percent)                                                   IV-450
                 Table IV-35             High Case OCS-Rclated Employment Projections (Direct+ Indirect+ Induced)/
                                         Western Gulf Sale 143 (person-years)                                              IV-452
                 Table IV-36             Population and Employment Impact Levels for the High Case Scenario!
                                         Western Gulf Sale 143 (percent)                                                   IV-453












                                                                                                                        xxv

               Table D-1            Coal Consumption by End-Use Sector (million short tons)                             D-4
               Table D-2            Coal Overview (million short tons)                                                  D-4
               Table D-3            Demonstrated Reserve Base of the Major Coal Provinces in the United States          D-4
               Table D-4            Production of Electricity from Geothermal Sources                                   D-9
               Table D-5            Solar Energy Collector to Land Ratios                                             D-11
               Table D-6            Hydroelectric Power in the United States - Total Potential                        D-12
               Table D-7            Comparison of NEPPP-Reference and High-Energy-Efficiency Cases (Quads)            D-17
               Table D-8            Replacement Energy Needs\Central and Western Planning                             D-18
                                      Areas (Base Case)











                                                                               xxvii

          ABBREVIATIONS AND ACRONYMS


          ac         acre
          ACAA       Alabama Coastal Area Act
          ACAMP      Alabama Coastal Area Management Program
          ADECA      Alabama Department of Community Affairs
          ADEM       Alabama Department of Environmental Management
          AFB        Air Force Base
          APD        Application for Permit to Drill
          API        American Petroleum Institute
          ARTC       Armament Research and Test Center
          B.P.       before present
          BACT       best available control technology
          BAST       best available and safest technology
          BAT        best available technology
          BbbI       billion barrels
          bbI        barrels
          BBO        billion barrels of oil
          bcf        billion cubic feet
          BLM        Bureau of Land Management
          BMR        Bureau of Marine Resources
          BOD        biological oxygen demand
          BOP        blowout preventer
          BPD        barrels per day
          Btu        British thermal unit
          CAA        Clean Air Act
          CAB        Coastal Area Board
          Call       Call for Information and Nominations
          CBRA       Coastal Barrier Resources Act of 1982
          CBRS       Coastal Barrier Resource System
          CEE        Center for Environmental Education
          CEI        Coastal Environments, Inc.
          CEQ        Council on Environmental Quality
          CER        categorical exclusion review
          CERCLA     Comprehensive Environmental Compensation and Liability Act
          CFR        Code of Federal Regulations
          CGA        Clean Gulf Associates
          cm         centimeter
          COE        Corps of Engineers (U.S. Army)
          CPA        Central Planning Area
          CRCPD      Conference of Radiation Program Directors
          CSA        Continental Shelf Associates
          CzM        Coastal Zone Management
          CZMA       Coastal Zone Management Act
          dB         decibel
          DER        Department of Environmental Regulation
          DM         Departmental Manual
          DOC        Department of Commerce (U.S.) (also: USDOC)
          DOCD       Development Operations Coordination Document
          DOD        Department of Defense (U.S.)
          DOE        Department of Energy (U.S.)










                      xxviii

                      DOI       Department of the Interior (U.S.) (also: USDOI)
                      DOT       Department of Transportation (U.S.) (also: USDOT)
                      DPP       Development/Production Plan
                      DST       deep stratigraphic test
                      DWG       Dispersant Working Group
                      dwt       deadweight tonnage
                      EA        environmental assessment
                      EIS       environmental impact statement
                      EP        Exploration Plan
                      EPA       Eastern Planning Area
                      ESD       Emergency Shutdown System
                      ESP       Environmental Studies Program
                      ESS       Emergency Support System
                      FAA       Federal Aviation Administration
                      FCF       Fishermen's Contingency Fund
                      FCMP      Florida Coastal Management Proeram
                      FERC      Federal Energy Regulatory Commission
                      FMC       Fisheries Management Council
                      FMP       Fishery Management Plan
                      FR        Federal Register
                      FRS       Fast Response System
                      FSV       flow safety valve
                      ft        foot
                      FWPCA     Federal Water Pollution Control Act
                      FWS       Fish and Wildlife Service
                      FY        fiscal year
                      G&G       geological and geophysical
                      GIWW      Gulf Intracoastal Waterway
                      GMFMC     Gulf of Mexico Fishery Management Council
                      GS        Geological Survey (U.S.) (also: USGS)
                      H.R.      House Resolution (U.S. Congress)
                      ha        hectare
                      HAPC      Habitat Area of Particular Concern
                      HOSS      High-Volume Open Sea Skimmer System
                      IMCO      Intergovernmental Maritime Consultative Organization
                      in        inch
                      IPF       impact-producing factor
                      ITL       Information to Lessees and Operators
                      ITS       Incidental Take Statement
                      km        kilometer
                      kn        knots
                      LCZMP     Louisiana Coastal Zone Management Program
                      LGS       Louisiana Geological Survey
                      LNG       liquefied natural gas
                      LOOP      Louisiana Offshore Oil Port
                      LSH       level sensor high
                      LSL       level sensor low
                      LTL       Letter to Lessees and Operators
                      m         meter
                      MAFLA     Mississippi, Alabama, Florida
                      MCP       Mississippi Coastal Program
                      MFCMA     Magnuson Fishery Conservation and Management Act of 1976










                                                                                            xxix


            mi           mile
            MIRG         Marine Industry Research Group
            MMbbI        million barrels
            MMC          Marine Mammal Commission
            MMcf         million cubic feet
            MMRI         Mississippi Mineral Resources Institute
            MMS          Minerals Management Service
            MOU          Memorandum of Understanding
            MPA          Marine Preservation Association
            MSRC         Marine Spill Response Corporation
            mta          million metric tons annually
            MWD          measurement while drilling
            NAAQS        National Ambient Air Quality Standards
            NAS          National Academy of Sciences
            NCP          National Contingency Plan
            NCSC         Naval Command System Center
            NEPA         National Environmental Policy Act
            NERBC        New England River Basins Commission
            NHPA         National Historic Preservation Act
            NMFS         National Marine Fisheries Service
            NOAA         National Oceanic and Atmospheric Administration
            NODC         National Oceanographic Data Center
            NOI          Notice of Intent to Prepare an EIS
            NORM         naturally occurring radioactive materials
            NPA          National Planning Association Data Services, Inc.
            NPDES        National Pollution and Discharge Elimination System
            NPS          National Park Service
            NRC          National Research Council
            NRT          National Response Team
            NSPS         new source performance standards
            NTL          Notice to Lessees and Operators
            OCDM         Offshore Coastal Dispersion Model
            OCRM         Office of Ocean and Coastal Resource Management
            OCS          Outer Continental Shelf
            OCSLA        Outer Continental Shelf Lands Act
            OHMSETT      Oil and Hazardous Materials Simulated Environmental Test Tank
            OSC          On-Scene Coordinator
            OSCP         Oil Spill Contingency Plan
            OSRA         Oil Spill Risk Analysis
            OTA          Office of Technology Assessment (U.S. Congress)
            P.L.         Public Law
            PINC         Potential Incident of Noncompliance
            PIRS         Pollution Incident Reporting System
            PPM          parts per million
            PSD          Prevention of Significant Deterioration
            PSH          high-pressure sensor
            PSL          low-pressure sensor
            PSV          pressure relief valve
            PWSA         Ports and Waterways Safety Act
            RCP          Regional Contingency Plan
            RCRA         Resource Conservation and Recovery Act
            RD           Regional Director












          xxx

          ROTAC       Regional Operations Technology Assessment Committee
          RRT         Regional Response Team
          RTWG        Regional Technical Working Group
          SARA        Superfund Amendments and Reauthorizations Act of 1986
          SEL         Site Evaluation List
          sic         Standard Industrial Classification
          SMA         Special Management Area
          SMSA        Standard Metropolitan Statistical Area
          SPCC        Spill Prevention Control and Countermeasure
          SPR         Strategic Petroleum Reserve
          SSSV        subsurface safety valve
          STOCS       South Texas Outer Continental Shelf
          SUSIO       State University System of Florida, Institute of Oceanography
          tcf         trillion cubic feet
          TSP         total suspended particulates
          TSS         traffic separation schemes
          U.S.        United States
          U.S.C.      United States Code
          USAF        U.S. Air Force
          USCG        U.S. Coast Guard
          USDOC       U.S. Department of Commerce (also: DOC)
          USDOI       U.S. Department of the Interior (also: DOI)
          USEPA       U.S. Environmental Protection Agency
          USGS        U.S. Geological Survey
          VOC         volatile organic compounds
          Voss        Vessel of Opportunity Skimming System
          WPA         Western Planning Area
          yd          yard
          yr          year










                                                                                                                                    xxxi


                 SUMMARY

                     This environmental impact statement (EIS) addresses two proposed Federal actions, lease Sales 142 and
                 143, that will offer for lease Gulf of Mexico Outer Continental Shelf (OCS) areas that may contain
                 economically recoverable oil and gas resources. The lease sales are proposed for 1993 and include lease blocks
                 in the Central Gulf of Mexico Planning Area (CPA) and Western Gulf of Mexico Planning Area (WPA).
                 Figure 1-1 provides statistics on the leasing status in these two areas. Approximately 9,900 blocks will be
                 available for lease under the two proposed actions; only a small percentage is expected to be actually leased.
                 On average, 434 blocks in the Central Gulf and 264 blocks in the Western Gulf have been leased in individual
                 Gulf of Mexico OCS lease sales since 1984. Of the blocks that will be leased as a result of the two proposed
                 actions, only a portion will be drilled and result in subsequent production.
                     The analytical methods used in this EIS have been formulated over a period of years. The first step of
                 the analysis is the identification of significant environmental and socioeconomic resources through the scoping
                 process outlined in Section I.13.2.c.(l). A range of energy resource estimates is derived from geologic and
                 economic assumptions and alternatives to the proposed action are established. Estimated levels of exploration
                 and development activity are assumed for the purposes of the analysis. An analysis of the potential interaction
                 between the significant environmental resources and the OCS-related activities is then conducted.
                     The scoping process (Section I.B.2.) was used to obtain information and comments on the proposed actions
                 and the potential environmental effects from diverse interests, including the affected States, Federal agencies,
                 the petroleum industry, environmental and public interest groups, and concerned individuals. The input from
                 these sources aided in the identification of significant issues, possible alternatives to the proposed actions, and
                 potential mitigating measures. The following are brief descriptions of the proposed actions, alternatives,
                 mitigating measures, and issues addressed in this EIS.

                 Proposed Actions and Alternatives

                     Proposed Central Gulf Sale 142 and the Alternatives

                     Alternative A (Proposed Central Gulf Sale 142) is scheduled to be held in March 1993 and may offer
                 approximately 5,194 unleased blocks (as of January 1992) comprising about 28.0 million acres in the CPA. This
                 area includes acreage located from 3 to 219 mi offshore in water depths ranging from 13 to over 11,000 ft.
                 There are no areas deferred from the CPA. This alternative includes existing regulations and proposed lease
                 stipulations designed to reduce environmental risks. It is estimated that the proposal could result in the
                 production of 0.14 billion bbl of oil (BBO) and 1.40 trillion cubic feet (tcf) of gas.
                     Alternative B (77te Proposed Action Ercluding the Blocks Near Biologically Sensitive Topographic Features)
                 would delete all unleased blocks of the 167 total blocks on or near biologically sensitive areas of the
                 topographic features in the Central Gulf. All of the remaining unleased area would be available for leasing.
                     Alternative C (No Action) equates to cancellation of the sale. Neither potential environmental effects nor
                 oil and gas production, which could result from the proposed action, would occur. Alternative energy resources
                 that might be used to replace energy resources lost by cancellation of this sale are discussed in Appendix D.

                     Proposed Western Gulf Sale 143 and the Alternatives

                     Alternative A (Proposed Western Gulf Sale 143) is scheduled to be held in August 1993 and may offer
                 approximately 4,715 unleased blocks (as of January 1992), comprising about 25.8 million acres in the WPA.
                 This area is located from 9 to 221 mi offshore in water depths ranging from 26 to over 9,000 ft. Excluded from
                 this proposed action -are Blocks A-375 (East Flower Garden Bank) and A-398 (West Flower Garden Bank)
                 in the High Island Area; these blocks are deferred because of the environmentally sensitive nature of the
                 biological communities located there. The East and West Flower Garden Banks have officially been designated
                 as marine sanctuaries. This alternative includes existing regulations and proposed lease stipulations designed










                 xxxii

                 to reduce environmental risks. It is estimated that the proposal could result in the production of 0.05 BBO
                 and 0.74 tcf of gas.
                     Alternative B (The Proposed Action Ercluding the Blocks Near Biologically Sensitive Topographic Features)
                 would delete all unleased blocks of the 200 total blocks on or near biologically sensitive areas of the
                 topographic features in the Western Gulf. All of the remaining unleased areas would be available for leasing,
                 except for the two deferred blocks at the Flower Garden Banks.
                     Alternative C (The ProposedActionErcluding Blocks Contained in the Western Naval OperationsArea) would
                 delete approximately 340 blocks contained in the Western Naval Operations Area near Corpus Christi, Texas.
                     Alternative D (No Action) equates to cancellation of the sale. Neither potential environmental effects nor
                 oil and gas production, which could result from the proposed action, would occur. Alternative energy resources
                 that might be used to replace energy resources lost by cancellation of this sale are discussed in Appendix D.

                 Mitigating Measures

                     Four potential stipulations have historically been applied to appropriate Gulf OCS leases, and these arc
                 analyzed as part of the proposed actions. These stipulations are the Live Bottom (Ilinnacle Trend),
                 Topographic Features, Archaeological Resource, and Military Area Stipulations for the Central Gulf sale; and
                 the Topographic Features, Archaeological Resource, and Military Area Stipulations for the Western Gulf sale.
                 Actual application of these stipulations to leases that may result from the proposed actions are options
                 available to the Secretary of the Interior.

                 Action Scenarios Analged

                     Oil and gas resources estimated to be leased and developed from the proposed lease sales are the basis
                 for environmental analyses of resources that may be impacted by OCS activities. These estimates, based on
                 many factors such as geologic structure, economic assumptions, proximity to existing development, etc., fall
                 within a large range. From these ranges, two scenarios are developed. The primary scenario @s called the Base
                 Case and assumes the mean or expected amounts of undiscovered, unleased hydrocarbon resources, and
                 resultant development activities. The second scenario is the High Case, which is the relatively less likely
                 possibility that the upper end of the range of energy resource estimates will be leased, discovered, and
                 dcvc10pcd.
                     An additional analysis is given of the environmental impacts that result from the incremental impact of the
                 lease sales when added to all past, present, and reasonably foreseeable future human activities. The outcome
                 of this analysis is labeled the cumulative impact on the particular resource under discussion and covers a period
                 of 35 years. This term, however, should not be confused with the cumulative impacts attributable to OCS
                 activities.
                     The environmental analyses are based on levels of assumed development activities correlated with the
                 amount of resources estimated to be leased (Table S-1). These activities include the number of platforms,
                 wells, pipelines, service vessel trips, etc. The interaction of all OCS activities that result from the lease sale
                 with environmental,resources is analyzed.

                 Significant Issues

                     Table S-2 lists the resources and activities determined through the scoping process tc) be sufficiently
                 important to warrant inclusion in this environmental analysis. The scoping process is an ongoing effort, and
                 contacts are made with other Federal and State Agencies, the public, academia, and environmental groups to
                 identify those resources about which there is concern. This process determines the significant resources and
                 activities to be addressed in the EIS.











                                                                                                                      xxxiii


               Impact Conclusions

                    Tables S-3 and S-4 provide a summary of the impacts of proposed Sales 142 and 143 and their alternatives
                under the Base Case, High Case, and cumulative analyses.










                xxxiv


















                                                                     Table S-1

                      Oil and Gas Resource and OCS Development Activity Estimates: Sales 142 and 143

                                                                     Central               Western
                                                                     Planning              Planning
                                                                      Area                  Area
                                                                      Sale 142             Sale 143
                                                                     Base Case            Base Case

            Acreage Available for Leasing'
              (million of acres)                                       28.0                 25.8
            Resources Expected to be Developed2
              Oil (billion barrels)                                     0.14                 0.05
              Gas (trillion cubic feet)                                 1.40                 0.74


            OCS Development Activity
              Exploration and Delineation Wells                       340                  210
              Platform Installations                                    30                  10
              Development Wells                                       250                  110
              Pipelines (kilometers)                                  240                   80


            'Unleased acreage available for leasing (deferred acreage not included) as of January 1992 for the Central
            and Western Gulf sales.
            2The methodology used to estimate resources is explained in Appendix C.
            Source: USDOI, Minerals Management Service, Gulf of Mexico OCS Region estimates, 1991.













                                                                                                                       )MXV















                                                                Table S-2


                                       Significant Environmental Resources and Activities Analyzed

                             Central Gulf Sale 142                                        Western Gulf Sale 143


                  Coastal Environments                                         Coastal Environments
                   Coastal Barrier Beaches                                       Coastal Barrier Beaches
                   Wetlands                                                      Wetlands
                  Offshore Environments                                        Offshore Environments
                   Live-bottoms (Pinnacle Trend)                                 Deep-water Benthic Communities
                   Deep-water Benthic Communities                                Topographic Features
                   Topographic Features                                        Water Quality
                  Water Quality                                                Air Quality
                  Air Quality                                                  Marine Mammals
                  Coastal and Marine Mammals                                     Nonendangered and Nonthreatened Species
                   Marine Mammals                                                Endangered and Threatened Species
                     Nonendangered and Nonthreatened                           Marine Turtles
                     Species                                                   Coastal and Marine Birds
                     Endangered and Threatened Species                           Nonendangered and Nonthreatened Species
                   Alabama, Choctawhatchee, and Perdido                          Endangered and Threatened Species
                      Key Beach Mice                                           Commercial Fisheries
                  Marine Turtles                                               Recreational Resources and Activities
                  Coastal and Marine Birds                                       Beach Use
                   Nonendangered and Nonthreatened Species                       Marine Fishing
                   Endangered and Threatened Species                           Archaeological Resources
                  Gulf Sturgeon                                                  Historic
                  Commercial Fisheries                                           Prehistoric
                  Recreational Resources and Activities                        Socioeconomic Conditions
                   Beach Use                                                     Population, Labor, and Employment
                   Marine Fishing                                                Public Services and Infrastructure
                  Archaeological Resources                                       Social Patterns
                   Historic
                   Prehistoric
                  Socioeconomic Conditions
                   Population, Labor, and Employment
                   Public Services and Infrastructure
                   Social Patterns






















                                                                                                                                       Table S-3


                                                                                                            Comparison and Summary of Impacts for Alternatives A-C
                                                                                                             and Cumulative in the Central Planning Area (Sale 142)

                             Alternatives                                                                                          Resource Categories

                                                               Coastal Barrier Beaches                                                             Wetlands                                                      Live Bottom (Pinnacle Trend)

                             Alternative A        The proposed action is not expected to result in          The proposed action is expected to result in dieback and mortality of 10-15 ha              The impact of the proposed action is expected
                             Base Case            permanent      alterations    of    barrier     beach     of wetlands vegetation as a result of contacts from onshore oil spills. All but 2           to be such that any changes in the regional
                                                  configurations, except       in localized areas           ha of these wetlands will recover within 10 years; the remaining 2 ha will be               physical integrity, species diversity, or biological
                                                  downdrift from navigation channels that have              converted to open water. About 5.5 ha of wetlands are projected to be eroded                productivity of the Pinnacle Trend region would
                                                  been dredged and deepened. The contributionto             along channel margins as a result of OCS vessel wake erosion, and 3.5 ha of                 recover to pre-impact conditions in less than 2
                                                  this localized erosion is expected to be less than        wetlands are projected to be created as a result of beneficial disposal ofdredged           years, more probably on the order of 24
                                                  1 percent.                                                material from channel-deepening projects.                                                   months.


                             Alternative A        Same as Alternative A - Base Case.                        The proposed action is expected to result in dieback and mortality of 10-15 ha              Same as Alternative A - Base Case.
                             High Case                                                                      of wetlands vegetation as a result of contacts from onshore oil spills. All but 2
                                                                                                            ha of these wetlands will recover within 10 years; the remaining 2 ha will be
                                                                                                            converted to open water. About 11 ha of wetlands are projected to be eroded
                                                                                                            along channel margins as a result of OCS vessel wake erosion, and 7 ha of
                                                                                                            wetlands are projected to be created as a result of beneficial disposal of dredged
                                                                                                            material from channel-deepening projects.

                             Alternative BI       Same as Alternative A - Base Case.                        Same as Alternative A - Base Case.                                                          Same as Alternative A - Base Case.


                             Alternative C'       No effect.                                                No effect.                                                                                  No effect.


                             Cumulative           The observed erosional trend of barrier features          Large losses of wetlands are expected to continue to occur. The main cause of               The cumulative impacts are expected to be such
                             Impacts              is expected to continue in onshore Subareas C-1,          these losses, particularly in coastal Louisiana where the largest amount of                 that this damage to one or more components of
                                                  C-2, and C-3. The major causes of these impacts           wetlands will be lost, is sediment deprivation and rapid coastal submergence.               a few regionally common habitats or
                                                  are sediment deficits and relative sea-level rise.        Other contributing factors include tideland oil and gas development, the erosion            communities results in changes to physical
                                                                                                            of navigation channel margins, and, to a lesser extent, impacts from oil spills.            integrity, species diversity, or biological
                                                                                                                                                                                                        productivity that exceeds natural variability
                                                                                                                                                                                                        (observed prior to the damage); recovery to

                                                                                                                                                                                                        than 10 years.

















                    Table S-3 Comparison and Summary of Impacts for Alternatives A-C and Cumulative in the Central Planning Area (Sale 142) (continued)

                    Alternatives                                                                                       Resource Categories

                                                       Deep-water Benthic                                              Topographic Features                                                               Water Quality
                                                           Communities
                        Alternative A       The proposed action is expected to cause        Ile proposed action is     expected to cause little to no damage to the          An identifiable change to the ambient concentration of one or more
                        Base Case           little damage to the physical integrity,        physical integrity, species diversity, or biological productivity of the         water quality parameters will be evident up to several hundred to
                                            species     diversity,    or     biological     habitats of the topographic features of the Gulf of Mexico. Small areas          1,000 m from the source and for a period lasting up to several weeks
                                            productivity of either the widespread,          of 5-10 m2 would be impacted, and recovery from this damage to pre-              in duration in marine and coastal waters. Chronic, low-level
                                            low-density chemosynthetic communities          impact conditions is expected to take less than 2 years, probably on the         pollution related to the proposal will occur throughout the life of the
                                            or the rarer, widely scattered, high-           order of 24 weeks.                                                               proposed action.
                                            density Bush Hill-type chemosynthetic
                                            communities.       Recovery from any
                                            damage is expected to take less than 2
                                            years.

                        Alternative A       Same as Alternative A - Base Case.              Same as Alternative A - Base Case.                                               Same as Alternative A - Base Case.
                        High Case
                        Alternative BI      Same as Alternative A - Base Case.              Alternative B is expected to cause little to no damage to the physical           Same as Alternative A - Base Case.
                                                                                            integrity, species diversity, or biological productivity of the habitats of the
                                                                                            topographic features of the Gulf of Mexico. Small areas of 5-10 m2
                                                                                            would be impacted, and recovery from this damage to pre-impact
                                                                                            conditions is expected to take less than 2 years, probably on the order
                                                                                            of 24 weeks. Selection of Alternative B would preclude oil and gas
                                                                                            operations in the unleased blocks affected by the proposed Topographic
                                                                                            Features Stipulation.

                        Alternative C'      No effect.                                      No effect.                                                                       No effect.

                        Cumulative          The cumulative impacts are expected to          The Cumulative scenario is expected to cause little to no damage to the          Cumulative demands resulting from the proposal are expected to
                        Impacts             cause little damage to the physical             physical integrity, species diversity, or biological productivity of the         result in significant changes to the ambient concentration of one or
                                            integrity, species diversity, or biological     habitats of the topographic features of the Gulf of Mexico. Small areas          more water quality parameters up to several hundred to 1,000 in from
                                            productivity of either the widespread,          of 5-10 in' would be impacted, and recovery from this damage to pre-             the source of activities and for a period lasting up to several weeks or
                                            low-density chemosynthetic communities          impact conditions is expected to take less than 2 years, probably on the         months in duration. Chronic, low-level pollution related to the
                                            or the rarer, widely scattered, high-           order of 2-4 weeks.                                                              proposal will occur throughout the life of the proposed action. Overall
                                            density Bush Hill-type chemosynthetic:                                                                                           cumulative impacts, which include the effects of non-OCS-related
                                            communities.       Recovery from any                                                                                             factors and OCS activities, will signifi- cantly degrade water quality,
                                            damage is expected to take less than 2                                                                                           primarily within the Gulf of Mexico's coastal zone, in highly urbanized
                                            vears.                                                                                                                           and industrialized coastal areas. Maritime activities will contribute to
                                                                                                                                                                             water quality degradation near ports and major navigation channels.
                                                                                                                                                                             In restricted or poorly flushed coastal waterbodies, localized increases
                                                                                                                                                                             in pollutant concentrations may be severe and persist for months or
                                                                                                                                                                             longer. Chronic, low-level pollution will continue to persist in marine
                                                                                                                                                                             and coastal waters.













                            Table S-3 Comparison and Summary of Impacts for Alternatives A-C and Cumulative in the Central Planning Area (Sale 142) (continued)
                            Alternatives                                                                                                Resource Categories

                                                                                                                                                                   Marine Mammals
                                                                                Air Quality                                     Nonendangered and Nonthreatened                      Endangered and Threatened                       Alabama, Choctawhatchee, and
                                                                                                                                                                                                                                         Perdido Key Beach Mice
                                                                                                                                The impact on nonendangered and                  The impact on endangered and
                            Alternative A               Emission of pollutants into the atmosphere are                          nonthreatened marine mammals                     threatened marine mammals within                  The   impact on beach mice within
                            Base Case                   expected to have concentrations that would not change                   within the potentially affected area             the potentially affected area is                  the   potentially affected area is
                                                        onshore air quality cWsifications.          An increase in              is expected to result in sublethal               expected to result in sublethal                   expected to result in sublethal
                                                        onshore concentrations of air pollutants is estimated to                effects that are chronic and could               effects that are chronic and could                effects that seldom occur and may
                                                        be about I AgM-3. This concentration will have minimal                  result in persistent physiological or            result in persistent physiological or             cause short-term physiological or
                                                        impacts during winter because onshore winds occur                       behavioral changes, as well as some              behavioral changes, as well as some               behavioral changes.
                                                        only about 37 percent of the time, with maximum                         degree of avoidance of the                       degree of avoidance of the
                                                        impacts in summer when onshore winds occur 61                           impacted area.                                   impacted area.
                                                        percent of the time.
                            Alternative A               Same as Alternative A - Base Case.                                      Same as Alternative A - Base Case.               Same as Alternative A - Base Case.                Same as Alternative A - Base Case.
                            High Case
                            Alternative BI              Same as Alternative A - Base Case.                                      Same as Alternative A - Base Case.               Same as Alternative A - Base Case.                Same as Alternative A - Base Case.
                            Alternative C'              No effect.                                                              No effect.                                       No effect.                                        No effect.
                            Cumulative Impacts          Emission of pollutants into the atmosphere from the                     The impact on nonendangered and                  The impact on endangered and                      The cumulative impact on beach
                                                        activities assumed for the OCS program are expected                     nonthreatened marine mammals                     threatened marine mammals within                  mice within the potentially affected
                                                        to have concentrations that may change onshore air                      within the potentially affected area             the potentially affected area is                  area is expected to result in a
                                                        quality   classifications.       Increases    in     onshore            is expected to result in a decline in            expected to result in a decline in                decline in species numbers or a
                                                        concentrations of air pollutants are estimated to be                    species numbers or a temporary                   species numbers or a temporary                    temporary displacement from their
                                                        between I and 14.5 ggM3 (box model steady                               displacement from their current                  displacement from their current                   current distribution, a decline or
                                                        concentrations). This concentration will have minimal                   distribution,     a    decline       or          distribution,      a    decline       or          displacement that wW last more
                                                        impact during winter because onshore winds occur only                   displacement that will last more                 displacement that will list more                  than one generation.
                                                        37 percent of the time, with maximum impacts in                         than one generation.                             than one generation.
                                                        summer when onshore winds occur 61 percent of the
                                                        time.



















                           Table S-3 Comparison and Summary of Impacts for Alternatives A-C and Cumulative in the Central Planning Area (Sale 142) (continued)

                           Alternatives                                                                                    Resource Categories

                                                                                                                                              Coastal and Marine Birds
                                                                       Marine Turtles                        Nonendangered and Nonthreatened                          Endangered and Threatened                                     Gulf Sturgeon
                           Alternative A               Ile impact on marine turtles within the             The impact on nonendangered and                    The impact on endangered and threatened             The impact on the Gulf sturgeon within the
                           Base Case                   potentially affected area is expected to            nonthreatened coastal and marine birds             birds within the potentially affected area is       potentially affected area is expected to result
                                                       result in sublethal effects that are chronic        within the potentially affected area is            expected to result in no discernible decline        in sublethal effects and cause short-term
                                                       and could result in persistent physiological        expected to result in no discernible decline       in a population or species and no change            physiological or behavioral changes.
                                                       or behavioral changes.                              in a population or species and no change           in distribution and/or abundance on a local
                                                                                                           in distribution and/or abundance on a local        or regional scale. Individuals experiencing
                                                                                                           or regional scale. Individuals experiencing        sublethal      effects    will    recover      to
                                                                                                           sublethal     effects    will    recover      to   predisturbance condition in less than one
                                                                                                           predisturbance condition in less than one          generation.
                                                                                                           generation.
                           Alternative A               Same as Alternative A - Base Case.                  Same as Alternative A - Base Case.                 Same as Alternative A - Base Case.                  Same as Alternative A - Base Case.
                           High Case


                           Alternative BI              Same as Alternative A - Base Case.                  Same as Alternative A - Base Case.                 Same as Alternative A - Base Case.                  Same as Alternative A - Base Case.

                           Alternative C'              No effect.                                          No effect.                                         No effect.                                          No effect.
                           Cumulative Impacts          The cumulative impact on marine turtles             The cumulative effect on coastal and               The impact on endangered and threatened             The impact on the Gulf sturgeon within the
                                                       within the potentially affected area is             marine birds within the potentially affected       birds within the potentially affected area is       potentially affected area is expected to result
                                                       expected to result in a decline in species          area is expected to result in a discernible        expected to result in a decline in species          in a decline in species number or a temporary
                                                       numbers or a temporary displacement                 decline in a local coastal or marine bird          number or a temporary displacement from             displacement from their current distribution,
                                                       from their current distribution, a decline          population or species, resulting in a              their current distribution, a decline or            a decline or displacement that will last more
                                                       or displacement that will last more than            change in distribution or abundance.               displacement that will last more than one           than one generation.
                                                       one generation.                                     Recruitment will return the population or          generation.
                                                                                                           affected species to their pre-impact level
                                                                                                           and/or condition within one to two
                                                                                                           generations. It is doubtful that this impact
                                                                                                           will affect regional populations.















                           Table S-3 Comparison and Summary of Impacts for Alternatives A-C and Cumulative in the Central Planning Area (Sale 142) (continued)
                           Alternatives                                                                                     Resource Categories


                                                                       Commercial Fisheries                                               Beach Use                                                                 Marine Fishing
                           Alternative A             The impact on commercial fisheries within the                 The proposed action is expected to result in minor                             Platforms installed within 30 mi of shore will
                           Base Case                 potentially affected area is expected to result in a short-   pollution events and nearshore operations that may                             attract fish and are likely to attract fishermen and
                                                     term decrease in a portion of a population of                 adversely affect the enjoyment of some beach users on                          improve fishing for a period of about 20 years,
                                                     commercial importance, in an essential habitat, or in         Texas and Louisiana beaches.                                                   but are unlikely to affect offshore fishing patterns
                                                     commercial fisheries on a local scale. Any affected                                                                                          in general unless the platforms are installed in
                                                     population is expected to recover to predisturbance                                                                                          nearshore locations where no platforms currently
                                                     condition in one generation.                                                                                                                 exist.
                           Alternative A             Same as Alternative A - Base Case.                            Same as Alternative A - Base Case.                                             The High Case scenario will likely result in a few
                           High Case                                                                                                                                                              more platforms that will be productive sports fish
                                                                                                                                                                                                  areas accessible to and used by offshore
                                                                                                                                                                                                  recreational fishermen throughout the CPX but
                                                                                                                                                                                                  it is unlikely to have a detectable impact on the
                                                                                                                                                                                                  recreational fishing industry at the regional level.
                                                                                                                                                                                                  A few local fishing markets could suffer short-
                                                                                                                                                                                                  term (up to one month) loss of business from a
                                                                                                                                                                                                  major pollution event; however, these same
                                                                                                                                                                                                  markets should experience long-term (15-20 yrs)
                                                                                                                                                                                                  benefit from platform installations accessible to
                                                                                                                                                                                                  local fishermen.
                           Alternative BI            Same as Alternative A - Base Case.                            Same as Alternative A - Base Case.                                             Same as Alternative A - Base Case.
                           Alternative C2            No effect.                                                    No effect.                                                                     No effect.
                           Cumulative Impacts        The cumulative effect on the commercial fishing industry      Although trash and accidental oil spills will continue to                      Continued offshore oil and gas development over
                                                     within the potentially affected area is expected to result    affect the ambience of recreational beaches between                            the next 35 years will continue to support,
                                                     in a discernible decline in populations of commercial         Alabama and Texas, the level of chronic pollution                              maintain, and facilitate offshore recreational
                                                     importanep,, in the. minlity of --tial hohi-t@, Or            @h-,M          A..-:-- - I.-                                                   '. . .  . -     __ .      .   ...       . .     .
                                                               - -_ __            _.                               --.. .11   ... 1.      '." - V@ kilu pupubcu dLalull.                          maing in the CPA and win extend the timc
                                                     commercial fishing activity. Recruitment will return any      Beach use at the regional level is unlikely to change;                         offshore oil and gas structures are a focus of
                                                     affected population, habitat, or activity to prc-impact       however, closure of specific beached or parks directly                         offshore fishing activity.
                                                     level and/or condition within two to three generations.       impacted by one or two oil spills greater than or equal
                                                                                                                   to 1,000 bbl is likely during cleanup operations.
























                          Table S-3 Comparison and Summary of Impacts for Alternatives A-C and Cumulative in the Central Planning Area (Sale 142) (continued)

                          Alternatives                                                                                      Resource Categories

                                                                                                                                                       Archaeological Resources

                                                                                                                                    Historic                                                                  Prehistoric

                          Alternative A                                                               There is a very small possibility of an impact between OCS oil              There is a very small possibility of an impact between OCS oil
                          Base Case                                                                   and gas activities and a historic shipwreck or site. Should such            and gas activities and a prehistoric site. Should such an impact
                                                                                                      an impact occur, unique or significant historic archaeological              occur, unique or significant prehistoric archaeological
                                                                                                      information could be IOSL                                                   information could be lost.
                          Alternative A
                          High Case                                                                   Same as Alternative A - Base Case.                                          Same as Alternative A - Base Case.

                          Mternative BI
                                                                                                      Same as Alternative A - Base Case.                                          Same as Alternative A - Base Case.
                          Alternative C2
                                                                                                      No effeCt.                                                                  No effect.
                          Cumulative Impacts
                                                                                                      The total of OCS program and non-program related impact-                    The total of OCS program and non-program-related impact-
                                                                                                      producing factors has likely resulted in and may yet result in loss         producing factors has likely resulted in and may yet result in loss
                                                                                                      of significant or unique historic archaeological information.               of significant or unique prehistoric archaeological information.
















                           Table S-3 Comparison and Summary of Impacts for Alternatives A-C and Cumulative in the Central Planning Area (Sale 142) (continued)


                           Alternatives                                                                                       Resource Categories

                                                                                                                              Socioeconomic Conditions


                                                                  Population, Labor, and Employment                                    Public Services and Infrastructure                                              Social Patterns

                           Alternative A                  The impact in the Central Gulf on the population,               Population and employment impacts will not result in                      It is expected that no net migration will occur as
                           Base Case                      labor, and employment of the counties and                       disruptions to community infrastructure and public services               a result of the proposed action. Deleterious
                                                          parishes of the Central and Western Gulf coastal                beyond what is anticipated by in-place planning and                       impacts to social patterns are expected to occur
                                                          impact area is expected to be less than I percent of            development agencies.                                                     in some individual cases as a result of extended
                                                          the levels expected in the absence of the proposal.                                                                                       work schedules, displacement from traditional
                                                                                                                                                                                                    occupations, and relative wages.

                           Alternative A                  Same as Alternative A - Base Case.                              Same as Alternative A - Base Case.                                        Same as Alternative A - Base Case.
                           High Case

                           Alternative BI                 Same as Alternative A - Base Case.                              Same as Alternative A - Base Case.                                        Same as Alternative A - Base Case.


                           Alternative C2                 No effect.                                                      No effect.                                                                No effeCt.

                           Cumulative Impacts             On a regional level, the cumulative impact from                 The cumulative impact is expected to result in deteriorating              It is expected that some loss of traditional
                                                          prior sales, the proposed actions, and future sales             conditions of existing infrastructure and difficulties in                 occupations will occur. Deleterious impacts to
                                                          on the population, labor, and employment of the                 delivering satisfactory levels of public services.                        cultural heritage and family life are also expected
                                                          counties and Parishes of the Central Gulf coastal                                                                                         to occur in some individual cases. It is expected
                                                          impact     area    is   significant, amounting to                                                                                         that these impacts will be greatest in coastal
                                                          approximately 3,310,400 person-years of                                                                                                   Subareas C-1, C-2, and C-3.
                                                          employment over the life of the proposed action
                                                          plus at least an additional 11,050 person-years of
                                                          employment associated with the clean-up of three
                                                          oil spills.    Locally, the cumulative impact to
                                                          population, labor, and employment is higher for
                                                          coastal Subareas C-I and C-2 along the western
                                                          and central Louisiana coastline, lower for coastal
                                                          Subarea C-3 in southeast Louisiana, and lowest for
                                                          coastal Subarea C-4 in Mississippi and Alabama.
                                                          Emplo-ent needs i-- support of OCS oil
                                                                                       F@
                                                          activity are likely to be met with the existing
                                                          population and available labor force.


                           IAJternative B - The Proposed Action Excluding the Blocks Near Biologically Sensitive Topographic Features.
                           2AIternative C - No Action.
























                                                                                                                                         Table S-4
                                                                                                              Comparison and Summary of Impacts for Alternatives A-D
                                                                                                               and Cumulative in the Western Planning Area (Sale 143)

                                Alternatives                                                                                         Resource Categories

                                                               Coastal Barrier Beaches                                     Wetlands                             Deep-water Benthic Communities                           Topographic Features

                           Alternative A            The proposed action is not expected to              The proposed action is expected to result in       The proposed action is expected to cause           The proposed action is expected to cause
                           Base Case                result in permanent alterations of barrier          no permanent alterations ofwetland habitat,        little damage to the physical integrity,           little to no damage to the physical integrity,
                                                    beach configurations, except in localized           except for the erosion of less than 1 ha of        species diversity, or biological productivity of   species diversity, or biological productivity
                                                    areas downdrift from channels that have             wetlands along navigation channel margins.         either    the widespread, low-density              of the habitats of the topographic features
                                                    been dredged and deepened.                   The    These losses could be offset or even               chemosynthetic communities or the rare,            of the Gulf of Mexico. Small areas of 5-10
                                                    contribution to this localized erosion is           exceeded by wetland gains from the                 widely scattered, high-density Bush HUI-type       M2 would be impacted, and recovery from
                                                    expected to be less than 1 percent.                 beneficial disposal of dredged material            chemosynthetic communities.           Recovery     this damage to pre-impact conditions is
                                                                                                        generated during channel maintenance and           from any damage is expected to take less           expected to take less than 2 years, probably
                                                                                                        deepening operations.                              than 2 years.                                      on the order of 2-4 weeks.

                           Alternative A            Same as Alternative A - Base Case.                  The proposed action is expected to result in       Same as Alternative A - Base Case.                 Same as Alternative A - Base Case.
                           High Case                                                                    no permanent alterations ofwetland habitat,
                                                                                                        except for the erosion of less than 2 ha of
                                                                                                        wetlands along navigation channel margins.
                                                                                                        These losses could be offset or even
                                                                                                        exceeded by wetland gains from the
                                                                                                        beneficial disposal of dredged material
                                                                                                        generated during channel maintenance and
                                                                                                        deepening operations.

                           Alternative BI           Same as Alternative A - Base Case.                  Same as Alternative A - Base Case.                 Same as Alternative A - Base Case.                 Alternative B is expected to cause little to
                                                                                                                                                                                                              no damage to the physical integrity, species
                                                                                                                                                                                                              diversity, or biological productivity of the
                                                                                                                                                                                                              habitats of the topographic features of the
                                                                                                                                                                                                              Gulf of Mexico. Small areas of 5-10 M2
                                                                                                                                                                                                              would be impacted, and recovery from this
                                                                                                                                                                                                              damage to pre-impact conditions is
                                                                                                                                                                                                              expected to take less than 2 years, probably
                                                                                                                                                                                                              on the order of 24 weeks. Selection of
                                                                                                                                                                                                              Alternative B would preclude oil and gas
                                                                                                                                                                                                              operations in the unleased blocks affected
                                                                                                                                                                                                              by the proposed Topographic Features
                                                                                                                                                                                                              Stipulation.

                           Alternative C2           Same as Alternative A - Base Case.                  Same as Alternative A - Base Case.                 Same as Alternative A - Base Case.                 Same as Alternative A - Base Case.






















                         Table S-4 Comparison and Summary of Impacts for Alternatives A-D and Cumulative in the Western Planning Area (Sale 143) (continued)

                         Alternatives                                                                                       Resource Categories

                                                            Coastal Barrier Beaches                                   Wetlands                             Deep-Water Benthic Communities                          Topographic Features


                         Alternative D3          No effect.                                         No effect.                                        No effect.                                        No effect.

                         Cumulative Impacts      The observed erosional trend of barrier            Losses of wetlands are expected to continue.      The Cumulative Scenario is expected to            The Cumulative Scenario is expected to
                                                 features will continue along the Gulf Coast        The major cause of this loss is expected to       cause little damage to the physical integrity,    cause little to no damage to physical
                                                 in the area of potential impact. The major         be coastal submergence.                           species diversity,or biological productivity of   integrity, species diversity, or biological
                                                 causes of the impacts is the reduction in                                                            either    the   widespread,        low-density    productivity of the habitats of the
                                                 sediment being delivered to the coastal                                                              chemosynthetic communities or the rare,           topographic features ofthe GutfofMexico.
                                                 littoral system, sea-level rise, the effects of                                                      widely scattered, high-density Bush Hill-type     Small areas of 5-10 ml would be impacted,
                                                 navigational and erosion control structures,                                                         chemosynthetic communiti@s.          Recovery     and recovery from this damage to pre-
                                                 and some recreational impacts.                                                                       from any damage is expected to take less          impact conditions is expected to take less
                                                                                                                                                      than 2 years.                                     than 2 years, probably on the order of 2-4
                                                                                                                                                                                                        weeks.





















                           Table S-4 Comparison and Summary of Impacts for Alternatives A-D and Cumulative in the Western Planning Area (Sale 143) (continued)

                           Alternatives                                                                                              Resource Categories

                                                                                                                                                                                                         Marine Mammals
                                                                      Water Quality                                          Air Quality                             Nonendangered and Nonthreatened                          Endangered and Threatened

                           Alternative A             An identifiable change to the ambient                 Emissions of pollutants into the atmosphere           The impact on nonendangered and                       The impact on endangered and threatened
                           Base Case                 concentration of one or more water quality            are expected to have concentrations that              nonthreatened marine mammals within the               marine mammals within the potentially
                                                     parameters will be evident up to several              would not change onshore air quality                  potentially affected area is expected to              affected area is expected to result in
                                                     hundred to 1,000 m from the source and for            classifications.      Increase in        onshore      result in sublethal effects that occur                sublethal effects that occur periodically and
                                                     a period lasting up to several weeks in               concentrations of air          pollutants are         periodically and result in short-term                 result in short-term physiological or
                                                     duration in marine and coastal waters.                estimated to be about I ugm-1.                This    physiological or behavioral changes, as well          behavioral changes, as wen as some degree
                                                     Chronic, low-level pollution related to the           concentration will have minimal impacts               as some degree of avoidance of the                    of avoidance of the impacted area(s).
                                                     proposal will occur throughout the life of            during winter because onshore winds occur             impacted area(s).
                                                     the proposed action.                                  only about 34 percent of the time, with
                                                                                                           maximum impacts in summer when onshore
                                                                                                           winds occur 85 percent of the time.



                           Alternative A             Same as Alternative A - Base Case.                    Same as Alternative A - Base Case.                    The impact on nonendangered and                       The impact on endangered and threatened
                           High Case                                                                                                                             nonthreatened marine mammals within the               marine mammals within the potentially
                                                                                                                                                                 potentially affected area is expected to              affected area is expected to result in
                                                                                                                                                                 result in sublethal effects that are chronic          sublethal effects that are chronic and could
                                                                                                                                                                 and could result in persistent physiological          result   in   persistent    physiological or
                                                                                                                                                                 or behavioral changes, as well as some                behavioral changes, as well as, some degree
                                                                                                                                                                 degree of avoidance of the impacted                   of avoidance of the impacted area(s).
                                                                                                                                                                 area(s).

                                                                                                           Same as Alternative A - Base Case.                    Same as Alternative A - Base Case.                    Same as Alternative A - Base Case.
                           Alternative BI            Same as Alternative A - Base Case.
                                                                                                           Same as Alternative A - Base Case.                    Same as Alternative A - Base Case.                    Same as Alternative A - Base Case.
                           Alternative C'            Same as Alternative A - Base Case.
                                                                                                           No effect.                                            No effect.                                            No effect.
                           Alternative D'            No effect.






















                         Table S-4 Comparison and Summary of Impacts for Alternatives A-D and Cumulative in the Western Planning Area (Sale 143) (continued)

                         Alternatives                                                                                       Resource Categories




                                                                                                                                                                                           Marine Mammals
                                                                 Water Quality                                      Air Quality                          Nonendangered and Nonthreatened                      Endangered and Threatened

                         Cumulative Impacts       Cumulative demands resulting from the            Emission of pollutants into the atmosphere        The impact on nonendangered and                   Tlke impact on endangered and threatened
                                                  proposal are expected to result in significant   from the activities assumed for the OCS           nonthreatened marine mammals within the           marine mammals within the potentially
                                                  changes to the ambient concentration of one      program within the WPA are expected to            potentially affected area is expected to          affected area is expected to result in a
                                                  or more water quality parameters up to           have concentrations that would not change         result in a decline in species numbers or         decline in species numbers or temporary
                                                  several hundred to 1,000 m from the source       onshore air qualityclassifications. Increases     temporary displacement from their current         displacement       from     their current
                                                  of activities and for a period lasting up to     in onshore concentrations of air pollutants       distribution, a decline or displacement that      distribution, a decline or displacement that
                                                  several weeks or months in duration.             from the High Case are estimated to be            will last more than one generation.               will last more than one generation.
                                                  Chronic pollution related to the proposal        between I and 14.5 ggM3 (box model steady
                                                  will occur throughout the life of the            concentrations).     This concentration will
                                                  proposed action.        Overall cumulative       have minimal impact during winter because
                                                  impacts, which include the effects of non-       onshore winds occur only 34 percent of the
                                                  OCS-related factors and OCS activities, will     time, with maximum impact in winter when
                                                  significantly degrade water quality, primarily   onshore winds occur 85 percent of the time.
                                                  within the Gulf of Mexico's coastal zone in
                                                  highly urbanized and industrialized coastal
                                                  areas. Maritime activities will contribute to
                                                  water quality degradation near ports and
                                                  major navigation channels. In restricted or
                                                  poorly flushed coastal waterbodies, localized
                                                  increases in      pollutant concentration
                                                  (nutrients, organic matter, trace metals,
                                                  organotins, hydrocarbons, etc.) may be
                                                  severe and persist for months or longer.
                                                  Chronic, low-level pollution will continue to
                                                  ne.mio in marine. and rnaqfal wqt m.






















                         Table S-4 Comparison and Summary of Impacts for Alternatives A-D and Cumulative in the Western Planning Area (Sale 143) (continued)

                         Alternatives                                                                                         Resource Categories

                                                                                                                                       Coastal and Marine Birds
                                                                  Marine Turtles                        Nonendangered and Nonthreatened                         Endangered and Threatened                              Commercial Fisheries

                         Alternative A            The impact on marine turtles within the            The impact on nonenclangered and                   The impact on endangered and threatened             The impact on commercial fisheries within
                         Base Case                potentially affected area is expected to           nonthreatened coastal and marine birds             birds within the potentially affected area is       the potentially affected area is expected to
                                                  result in sublethal effects that are chronic       within the potentially affected area is            expected to result in no discernible decline        result in no discernible decrease in a
                                                  and could result in persistent physiological       expected to result in no discernible decline       in a population or species and no change in         population of commercial importance, its
                                                  or behavioral changes.                             in a population or species and no change in        distribution and/or abundance on a local or         essential habitat, or in commercial fisheries
                                                                                                     distribution and/or abundance on a local or        regional scale.      Individuals experiencing       on a local scale. Any affected population
                                                                                                     regional scale.     Individuals experiencing       sublethal     effects    will    recover      to    is expected to r=ver to predisturbance
                                                                                                     sublethal     effects    will    recover      to   predisturbance conditions in less than one          condition in one generation.
                                                                                                     predisturbance condition in less than one          generation.
                                                                                                     generation.

                         Alternative A            Same as Alternative A - Base Case.                 Same as Alternative A - Base Case.                 Same as Alternative A - Base Case.                  Same as Alternative A - Base Case.
                         High Case

                         Alternative   BI         Same as Alternative A - Base Case.                 Same as Alternative A - Base Case.                 Same as Alternative A - Base Case.                  Same as Alternative A - Base Case.


                         Alternative C2           Same as Alternative A - Base Case.                 Same as Alternative A - Base Case.                 Same as Alternative A - Base Case.                  Same as Alternative A - Base Case.


                         Alternative   D3         No effect.                                         No effect.                                         No effect.                                          No effect.

                         Cumulative Impacts       The impact on marine turtles within the            The cumulative effect on coastal and marine        The impact of the Cumulative Case                   The cumulative on the commercial fishing
                                                  potentially affected area is expected to           birds within the potentially affected area is      Scenario on endangered and threatened               industrywithin the potentially affected area
                                                  result in a decline in species numbers or          expected to result in a discernible decline in     birds within the potentially affected area is       is expected to result in a discernible decline
                                                  temporary displacement from their current          a local coastal or marine bird population or       expected to result in a decline in species          in populations of commercial importance,
                                                  distribution, a decline or displacement that       species, resulting in a change in distribution     number or temporary displacement from               in the quality of essential habitats, or in
                                                  will last more than one generation.                or abundance. Recruitment will return the          their current distribution, a decline or            commercial iishing activity. Recruitment
                                                                                                     population or affected species to its pre-         displacement that will last more than one           will return any affected population, habitat,
                                                                                                     impact level and/or condition within one to        generation.                                         or activity to pre-impact level and/or
                                                                                                     two generations. It is doubtful that this                                                              condition within two to three generations.
                                                                                                     impact will affect regimial populations.













                                                                                                                                                                                                                                                  Z






                           Table S4 (continued) Comparison and Summary of Impacts for Alternatives A-D and Cumulative in the Western Planning Area (Sale 143)


                           Alternatives                                                                                     Resource Categories

                                                                                Recreational Resources and Activiies                                                                      Archaeological Resources
                                                                    Beach Use                                      Marine Fishing                                       Historic                                        Prehistoric
                           Alternative A           The proposed action is expected to result in     One platform complex (2-3 structures)            There is a very small possibility of an impact    There is a very small possibility of an
                           Base Case               periodic loss of solid waste items likely to     installed as a result of this proposal within    between OCS off and gas activities and a          impact between OCS oil and gas activities
                                                   wash up on recreational beaches, which is        30 mi of shore is expected to attract            historic shipwreck or site. Should such an        and a prehistoric site. Should such an
                                                   expected to diminish enjoyment of some           fishermen and improve fishing success in the     impact occur, unique or significant historic      impact occur, unique or significant
                                                   beach visits but is unlikely to affect the       vicinity of the platform complex for a period    archaeological information could be lost.         prehistoric archaeological       information
                                                   number or type of visits currently occurring     of about 20 years.                                                                                 could be lost.
                                                   on Texas beaches.

                           Alternative A           Same as Alternative A - Base Case.               Same as Alternative A - Base Case.               Same as Alternative A - Base Case.                Same as Alternative A - Base Case.
                           High Case


                           Alternative BI          Same as Alternative A - Base Case.               Same as Alternative A - Base Case.               Same as Alternative A - Base Case.                Same as Alternative A - Base Case.

                           Alternative C'          Same as Alternative A - Base Case.               Same as Alternative A - Base Case.               Same as Alternative A - Base Case.                Same as Alternative A - Base Case.

                           Alternative D1          No effect.                                       No effect.                                       No effect.                                        No effect.

                           Cumulative Impacts      Although trash and accidental oil spills will    Continued offshore oil and gas development       The total of OCS program and nonprogram-          The total of OCS program and
                                                   continue to affect the ambience of Texas         over the next 35 years will continue to          related impact-producing factors have likely      nonprogram-related        impact-producing
                                                   recreational beaches, the level of chronic       support, maintain, and facilitate offshore       resulted in loss and may yet result in loss of    factors have likely resulted in loss and may
                                                   pollution should decline during the life of      recreational fishing in the WPA and extend       significant or unique historic archaeological     yet result in loss of significant or uniqu@
                                                   the proposed action.     Beach use at the        the time offshore oil and gas production         information.                                      prehistoric archaeological information.
                                                   regional level is unlikely to change; however,   structures are a focus of offshore fishing
                                                   closure of specific beaches or parks directly    activity.
                                                   impacted by one or two oil spills greater
                                                   than or equal to 1,000 bbl is likely during
                                                   cleanup operations.


















                         Table S4 Comparison and Summary of Impacts for Alternatives A-D and Cumulative in the Western Planning Area (Sale 143) (continued)

                         Alternatives                                                                                       Resource Categories

                                                                                                                                     Socioeconomic Conditions


                                                              Population, Ubor, and Employment                                 Public Services and Infrastructure                                          Social Patterns

                         Alternative A           The impact in the Western Gulf on the population, labor, and         Population and employment impacts will not result          It is expected that no net migration will occur as a result of the
                         Base Case               employment of the counties and parishes of the Central and           in disruptions to community infrastructure and             proposed action. Deleterious impacts to social patterns are
                                                 Western Gulf Coastal impact area is expected to be less than         public services beyond what is anticipated by in-          expected to occur in some individual cases as a result of
                                                 I percent of the levels expected in the absence of the               place planning and development agencies.                   extended work schedules, displacement from traditional
                                                 proposal.                                                                                                                       occupations, and relative wages.

                         Alternative A           Same as Alternative A - Base Case.                                   Same as Alternative A - Base Case.                         Same as Alternative A - Base Case.
                         High Case



                         Alternative BI          Same as Alternative A - Base Case.                                   Same as Alternative A - Base Case.                         Same as Alternative A - Base Case.


                         Alternative C'          Same as Alternative A - Base Case.                                   Same as Alternative A - Base Case.                         Same as Alternative A - Base Case.


                         Alternative D1          No effect.                                                           No effect.                                                 No effect.

                         Cumulative Impacts      The impact from prior sales, the proposed actions, and future        The impact on public services and community                Under the cumulative scenario, it is expected that some loss of
                                                 sales on the population, labor, and employment of the                infrastructure is not expected to result in long-term      traditional occupations will occur.       Deleterious impacts to
                                                 counties and of the coastal impact area is significant,              (greater than 3 years) disruptions in delivery of          cultural heritage and family life are also expected to occur in
                                                 amounting to approximately 277,300 person-years of                   public services or maintenance of community                some individual cases.
                                                 employment over the life of the proposed action.                     infrastructure because of the diversified local
                                                 Employment needs in support of OCS oil and gas activity are          economyand the small percentage of impact of the
                                                 likely to be met with the existing population and available          OCS     program     on    local    employers      and
                                                 labor force.                                                         demographies.



                         'Alternative B - The Proposed Action Excluding the Blocks Near Biologically Sensitive Topographic Features
                         2A]ternative C - The Proposed Action Excluding the Western Naval Operations Area
                         3AJternative D - No Action







    THE PROPOSED ACTIONS


    ALTERNATIVES INCLUDING
    THE PROPOSED ACTIONS

    DESCRIPTION OF THE
    AFFECTED ENVIRONMENT

    ENVIRONMENTAL
    CONSEQUENCES
    CONSULTATION AND              v
    COORDINATION

    BIBLIOGRAPHY AND
    SPECIAL REFERENCES           V-L

    PREPARERS                    V14L
                               IV

















    GLOSSARY

    APPENDICES





 \I

  N I






  IN


 \v


  ATI


  A'T I I
 /?- I I I

  ,A-X
 IN=




I

                                 i



























I


    SECTION IV
    ENVIRONMENTAL               IV
    CONSEQUENCES










                                                                                                                             IV-159

                 D. ENVIRONMENTAL IMPACTS OF THE PROPOSED ACTIONS
                      AND ALTERNATIVES

                 1. Proposed Central Gulf Sale 142

                     Proposed Central Gulf Sale 142 is scheduled to be held in March 1993. Details of the proposal are in
                 Section I.A. Alternatives to the proposed action and mitigating measures are described in Section II.A_
                     The analyses of impacts are based on scenarios for the Base Case, High Case, and Cumulative Case.
                 These scenarios were formulated to provide sets of assumptions and estimates on the amounts, locations, and
                 timing for OCS exploration, development, and production operations and facilities, both offshore and onshore.
                 These are estimates only and not predictions of what will happen as a result of holding this proposed sale. A
                 detailed discussion of the development scenarios and major, related impact-producing factors is included in
                 Sections IV.A. and B. The four potential mitigating measures (Live Bottom (Pinnacle Trend), Topographic
                 Features, Archaeological Resources, and Military Areas Stipulations) are considered part of the proposed
                 actions for analysis purposes.

                 a. Alternative A - The Proposed Action

                     To facilitate the analysis, the Federal offshore area is divided into subareas. The CPA comprises four
                 subareas (C-1, C-2, C-3, and C4) and the coastal region is divided into four coastal subareas (C-1, C-2, C-3,
                 and C4). These subareas are delineated on Figure IV-1.

                 (1) Impacts on Sensitive Coastal Environments

                 (a) Coastal Banier Beaches

                     The major impact-producing factors associated with the proposed action that could affect barrier landforms
                 include oil spills, pipeline emplacements, navigation canal dredging and maintenance dredging, and support
                 infrastructure construction. This section considers impacts to the physical shape and structure of the landform.
                 Impacts to other aspects of the barrier environment, such as the animals that inhabit the island, the recreational
                 value of the beaches, and the archaeological resources that may occur here, are described in other sections.
                     Oil spills can affect barrier beach stability if cleanup operations remove large quantities of sand, and if the
                 oil contacts and kills sand dune vegetation. During cleanup operations after a spill, if large quantities of sand
                 were scraped away and removed, a new beach profile and plan configuration would be established to adjust
                 to the lessened sand supply. The net result of these changes would be accelerated rates of shoreline erosion,
                 especially in a sand-starved, eroding-barrier setting. Further, areas where oiling has weakened or destroyed
                 sand dune vegetation could become eventual sites of island breaching.
                     Pipeline landfall sites across barrier islands have been identified as potential causes of accelerated beach
                 erosion and island breaching. A recently completed, MMS-funded study, however, showed little to no impact
                 to barrier beaches as a result of pipeline crossings (Wicker et al., 1989). Other investigators have monitored
                 pipeline landfall projects on Gulf of Mexico barrier islands and have shown that, with proper construction
                 techniques, landfall projects can be done with minor impacts to the beach topography (LeBlanc, 1985;
                 Mendelssohn and Hester, 1988).
                     The dredging and stabilization of navigation channels through barrier beach passes could affect the stability
                 of the barrier landform. A deepened channel through a barrier pass could serve as a sediment sink and
                 deprive downdrift beach areas of sediment. Jetties constructed perpendicularly to a channel entrance could
                 block the transport of sediments to downdrift beach areas. Periodic maintenance dredging of these channels
                 could exacerbate these conditions by continually deepening the channel. A recently completed MMS study of
                 navigation channel impacts on barrier beaches, however, showed little accelerated erosion near channels, except
                 in some areas immediately downdrift from a jetty (Wicker et al., 1989).










                   IV-160

                       Some onshore infrastructure used to support OCS operations has been constructed on barrier beaches in
                   Louisiana. The construction of new facilities would result in the loss of barrier habitat and the possible need
                   to stabilize the beach from subsequent erosion to protect the construction. Previous studies have shown that
                   efforts to stabilize and "armor" beaches can lead to accelerated erosion in areas away from the protected beach.

                   Base Case Ana4u&

                       Oil spills associated with the proposed action can occur from a number of sources. Spills can occur
                   offshore as a result of platform accidents, barge or tanker collisions, and pipeline breaks. Spills can also occur
                   inshore as a result of barge, pipeline, and storage tank accidents.
                       According to Table IV-21, there is a 1 percent or less chance of an offshore spill greater than or equal to
                   1,000 bbl (one 6,500-bbl spill is assumed) occurring and contacting within 10 days a coastal barrier. Based on
                   these low probabilities, the assumption is that no spills greater than or equal to 1,000 bbl from offshore sources
                   will occur and contact a coastal barrier. Furthermore, no spills greater than or equal to 1,OCO bbI from shuttle
                   tankers in port are assumed to occur under the Base Case scenario.
                      No spills greater than 50 bbl and less than 1,000 bbl are assumed to occur and conuict the coast from
                   either offshore or inshore sources under the Base Case scenario (Section IV.C.1 and Table IV-4). Several
                   spills greater than 1 and less than or equal to 50 bbl are assumed to occur inshore as a result of pipeline and/or
                   barge accidents, and a few spills of this size category are assumed to occur from offshore sources and contact
                   the coast (Table IV4).
                      At least 30 percent of the volume of an offshore spill greater than 1 and less than or equal to 50 bbI Will
                   weather prior to contacting shore. As much as 35 bbl of oil could, therefore, contact a barrier feature if a 50-
                   bbl spill occurred on the landward edge of the OCS. It is assumed that the beached oil win be spread over
                   about a 2-km length of beach, with only light oiling over much of this distance. Cleanup crews will manually
                   clean the small amounts of oil that contact the beach. No sand will be taken from the littoral transport system
                   as a result of the cleanup operations. The beach is expected to readjust to its prespill configuration within a
                   few months.
                      In regard to small onshore spillsi terminals that receive oil barged from OCS platforms are not located on
                   barrier features, so an accident that occurs during oil transfer operations at a terminal will not likely affect the
                   seaward side of a barrier landform. For a barge accident to affect a barrier beach, the accident would have
                   to occur while the barge is in transit and as a result of a collision or grounding near a barrier beach. Oil barges
                   make extensive use of the Intracoastal Waterway when transporting cargoes to terminals or refineries. The
                   Intracoastal Waterway is located inland from the coast in Louisiana, so oil spilled from a barge in transit will
                   not likely contact a barrier feature. In Mississippi, the Intracoastal Waterway cuts across Mississippi Sound.
                   Although there are no terminals located in Mississippi or Alabama that receive OCS crude directly from an
                   offshore platform, some secondary coastwise movement of OCS crude could occur via barge in Mississippi
                   Sound. The two barge trips projected for Texas ports (Table IV4) are not expected to result in an oil-spill
                   incident.
                      For a pipeline accident spill to contact a barrier feature, the accident would have to occur either in coastal
                   waters near the barrier, where the pipeline crosses the barrier, or in the sound that separates a barrier island
                   from the mainland. Such a spill occurred in Mississippi Sound in September 1989 and resulted in the oiling
                   of the landward side of Horn Island. Pipeline accidents, however, would most likely affect barrier features in
                   coastal Louisiana, where there are many more existing pipelines.
                      Of the several spills greater than 1 and less or equal to 50 bbl that occur inshore, only one or two are
                   assumed to contact a barrier feature. The others will be too small (a few barrels) to contact a beach or will
                   occur in locations that do not provide a route for the oil to reach a barrier. The spills that do contact a barrier
                   will be more likely to occur on the landward side of a barrier island, given the location of"barge routes and
                   terminals and pipelines relative to barriers. These spills are assumed to contact about 2 krn of backbarrier
                   coast, with most of this length experiencing light oiling. Cleanup crews will manually clean the spill, and no
                   impacts to beach morphology are projected. This scenario is especially likely given that the affected barrier
                   setting is in a low-energy lagoonal environment where erosion and sediment movement activity is diminished.











                                                                                                                            IV-161

                     Inshore spills in Mississippi Sound could contact the landward sides of barrier islands that are included in
                 the Gulf Islands National Seashore (Ship, Horn, and Petit Bois Islands). In September 1989, a 100-bbl spill
                 from a pipeline accident in Mississippi Sound oiled about a 1.5-kni stretch of the landward side of Horn Island.
                 The oil was removed from the beach by flushing the sand with seawater and mopping the refloated oil with
                 sorbents. No loss of sand or change in beach morphology occurred as a result of the cleanup. An additional
                 10 kin of beach was lightly oiled and did not require any cleanup activity. Inspection of the island by MMS
                 seven months after the spill revealed that only a thin layer of oiled sand remained along the seaward edge of
                 the beach berm. No impacts to barrier beaches in the Gulf Island National Seashore are expected as a result
                 of oil-spill contacts. The spill of September 1989, however, did result in mortalities to subtidal and intertidal
                 benthic crustaceans along the oiled stretches of the island. Marine and coastal birds were observed feeding
                 upon these oiled crustaceans.
                     Oil from spills greater than 1 and less than or equal to 50 bbl is not assumed to affect sand dune
                 vegetation. Heights of dune lines range from 0.5 to 1.3 m above mean high tide levels. For tides to reach or
                 exceed this level, strong southerly winds would have to persist for an extended time prior to or immediately
                 after the spill. An analysis of 37 years of tide gauge data from Grand Isle, Louisiana, shows that the probability
                 of water levels reaching sand dune elevations ranges from 0 to 16 percent. The likelihood that a spill greater
                 than I and less than or equal to 50 bbl will contact a barrier feature at the same time that tide levels exceed
                 sand dune elevations is low. In addition, the strong winds required to produce the high tides would disperse
                 and spread the off slick and reduce the concentration of oil that would occur at a coastal location.
                 Furthermore, a recent study in Texas has shown that the disposal of oiled sand on vegetated sand dunes had
                 no deleterious effects on the existing vegetation or on the recolonization of the oiled sand (Webb, 1988).
                 Based on all of these considerations, the expectation is that off spills will not affect sand dune vegetation.
                     No new pipeline landfalls are projected to occur under the Base Case scenario (Section IV.A.3.b.(l)).
                 Furthermore, in the event of an unforeseen hydrocarbon discovery that would require a new landfall, modern
                 techniques of pipeline emplacement and planning procedures can reduce pipeline crossing impacts to negligible
                 levels (LeBlanc, 1985; Mendelssohn and Hester, 1988; Wicker et al., 1989).
                     No new navigation facilities or infrastructure is expected under the Base Case scenario (Section
                 IV.A.3.b.(4)); therefore, impacts from these activities are precluded. Some periodic maintenance dredging of
                 navigation channels through barrier passes is expected, but this activity has not been documented to have a
                 noticeable, deleterious effect on barrier morphology. Furthermore, the contribution of the Base Case scenario
                 to the vessel traffic within navigation channels is very small (Table IV-10), so maintenance dredging cannot be
                 attributed to activities associated with the Base Case.
                     Section IV.A.3.c.(3)(c) states that the channel leading to Port Fourchon, Louisiana (Belle Pass), will be
                 deepened to 6.7 in (22 ft) to provide access for larger service vessels used for deep-water operations. It is
                 assumed that 2 percent of the impacts of this project can be attributed to Base Case scenario activities. Wicker
                 et al. (1989) have studied the effects of navigation channel dredging and maintenance operations on coastal
                 processes, and at Belle Pass in particular. Prior to the dredging of the channel to Port Fourchon and to the
                 construction of jetties at the channel entrance, the coast east (updrift) of the channel was retreating at a rate
                 of 40 m/yr, compared to 31 m/yr west (downdrift) of the channel. The difference in retreat rates (30% higher
                 to the west) can perhaps be attributed to the channel's acting as a sediment sink in this predominantly east-to-
                 west littoral drift environment. After dredging and jetty construction, the difference between the east and west
                 erosion rates increased to 50 percent, although the magnitude of the retreat rate decreased by nearly one half.
                 In 1974, the Corps of Engineers (COE) began to use material from maintenance dredging operations in Belle
                 Pass to nourish the beach areas west of the channel. Since then, no significant difference between east and
                 west erosion rates has been observed, and the absolute erosion rate has decreased by about another one half.
                 The COE's feasibility report for the Belle Pass deepening project indicates that some of the dredged material
                 be used for beach nourishment (U.S. Dept. of the Army, COE, 1991). Based on this information, the
                 expectation is that there will be no increase in ongoing erosion rates of barrier islands and beaches is expected
                 as a result of channel deepening.










                 IV-162

                 Summary

                      Ofl-spill contact to a barrier island could result in erosional changes in the barrier if cleanup operations
                 removed large quantities of sand. Because of the very low probability of occurrence and contact from either
                 an offshore or onshore spill of greater than 50 bbl, however, it is assumed that no contact from such a spill will
                 occur. Several spills greater than 1 and less than or equal to 50 bbl are assumed to contact coastal areas of
                 the CPA under the Base Case scenario from barge and pipeline accidents and from offshore sources. These
                 spills will contact mainly the landward side of barrier islands, will affect only a short stretch of beach, and will
                 be cleaned within a week with no effects on beach morphology.
                      Impacts from onshore and nearshore construction of OCS-related infrastructure (pipeline landfalls,
                 navigation channels, service bases, platform yards, etc.) are not expected to occur, because no new
                 infrastructure construction is anticipated as a result of the proposed action. Although some maintenance
                 dredging is expected to occur, this activity has not been shown to have a negative impact on barriers, and the
                 need for dredging cannot be attributed to the small percentage of vessel traffic in these channels accounted
                 for by Base Case activities. Deepening of the channel to Port Fourchon is not expected to affect nearby barrier
                 features.
                      It follows from the above that activities resulting from the proposed action will not have a significant
                 impact on coastal barriers.

                 Conclusion


                      The proposed action is not expected to result in permanent alterations of barrier beach configurations,
                 except in localized areas downdrift from navigation channels that have been dredged and deepened. The
                 contribution to this localized erosion is expected to be less than I percent

                 High Case Analysis

                      According to Table IV-21, there is a I percent or less chance of an offshore spill greater than or equal to
                 1,000 bbl occurring and contacting within 10 days a coastal barrier in the CPA, although one 6,500-bbl spill is
                 assumed to occur. Based on these low probabilities, the assumption is that no spills greater than or equal to
                 1,000 bbl from offshore sources will contact a coastal barrier. Furthermore, no spills greater than or equal to
                 1,000 bbl from shuttle tankers in port are assumed to occur under the High Case scenario.
                      No spills greater than 50 and less than 1,000 bbl are assumed to occur and contact coastal barriers under
                 the High Case scenario (Section IV.C.1). Several spills greater than 1 and less than or equal to 50 bbl are
                 assumed to occur and contact coastal barriers. The inshore spills are assumed to occur as a. result of coastal
                 pipeline or barge accidents, or during transfer operations at terminals. Terminals that receive oil barged from
                 OCS platforms are not located near barrier features, so an accident that occurs during oil transfer operations
                 at a terminal will not likely affect the seaward side of a barrier landform. For a barge accident to affect a
                 barrier beach, the accident would have to occur while the barge is in transit and as a result of a collision or
                 grounding near a barrier beach. Oil barges make extensive use of the Intracoastal Waterway when
                 transporting cargoes to terminals or refineries. The Intracoastal Waterway is located inland from the coast in
                 Louisiana, so off spilled from a barge in transit will not likely contact a barrier feature. In Mississippi, the
                 Intracoastal Waterway cuts across Mississippi Sound. Although there are no terminals located in Mississippi
                 or Alabama that receive OCS crude directly from an offshore platform, some secondary coastwise movement
                 of OCS crude could occur via barge in Mississippi Sound. An accident there involving a barge carrying crude
                 oil to the Pascagoula, Mississippi, refinery could result in spilled oil contacting a barrier island.. The four barge
                 trips projected for Texas ports (Table IV4) are not expected to result in an oil-spill incident.
                      For a pipeline accident spill to contact a barrier feature, the accident would have to occur either in coastal
                 waters near the barrier, where the pipeline crosses the barrier, or in the sound that separates a barrier island
                 from the mainland. Such a spill occurred in Mississippi Sound in September 1989 and resulted in the oiling
                 of the landward side of Horn Island. Pipeline accidents, however, would most likely affect barrier features in
                 coastal Louisiana, where there are many more existing pipelines.











                                                                                                                            IV-163

                     Of the several spills greater than 1 and less than or equal to 50 bbl that occur inshore, only one or two are
                 assumed to affect a barrier feature. The others will be too small (a few barrels) to contact the beach or will
                 occur in locations that do not provide a route for the oil to reach a barrier. The inshore spills that do contact
                 a barrier will occur on the landward side of a barrier island located most likely in Louisiana, but also possibly
                 in Mississippi. Offshore spills will contact the seaward side of barriers in coastal Louisiana. These spills are
                 expected to contact about 2 kin of barrier beach, with most of this length experiencing light oiling. The spills
                 will be manually cleaned, and no impacts to beach morphology are expected.
                     Oil from any of these small spills is not assumed to affect sand dune vegetation. In coastal Louisiana, dune
                 line heights range from 0.5 to 1.3 in above mean high tide levels. For tides to exceed this level, strong
                 southerly winds would have to persist for an extended time prior to or immediately after the spill. An in-house
                 analysis of 37 years of tide gauge data from Grand Isle, Louisiana, shows that the probability of water levels
                 reaching sand dune elevations ranges from 0 to 16 percent. The combined probabilities of occurrence and
                 contact from a small spill associated with the proposed action and tidal inundation of sand dune vegetation are
                 a very unlikely event. In addition, the strong winds required to produce the high tides would disperse and
                 spread the oil slick and reduce the oil concentration that would occur at a coastal location. Furthermore, a
                 recent study in Texas has shown that the disposal of oiled sand on vegetated sand dunes had no deleterious
                 effects on the existing vegetation or on the recolonization of the oiled sand (Webb, 1988). Based on all of
                 these considerations, the expectation is that oil spills will not affect sand dune vegetation.
                     No new pipeline landfalls are projected to occur under the High Case scenario (Section IV.A.3.b.(1)).
                 Furthermore, in the event of a pipeline landfall as a result of an unforeseen hydrocarbon discovery, modern
                 techniques of pipeline emplacement and planning procedures can eliminate pipeline crossing impacts (LeBlanc,
                 1985; Mendelssohn and Hester, 1988; Wicker et al., 1989).
                     No new navigation channels are expected to be dredged under the High Case scenario (Section
                 IV.A.3.b.(4)); therefore, impacts from these activities are precluded. Some periodic maintenance dredging of
                 navigation channels through barrier passes is expected, but this activity has not been documented as having a
                 noticeable effect on barrier morphology. Furthermore, the contributionof the High Case scenario to the vessel
                 traffic within navigation channels is very small, so only a small percentage of the maintenance dredging done
                 during the life of the proposed action can be attributed to activities associated with the High Case.
                     Section IV.A.3.c.(3)(c) states that the channel leading to Port Fourchon, Louisiana (Belle Pass), will be
                 deepened to 6.7 in (22 ft) to provide access for larger service vessels used for deep-water operations. It is
                 assumed that four percent of the impacts of this project can be attributed to High Case scenario activities.
                 Wicker et al. (1989) have studied the effects of navigation channel dredging and maintenance operations on
                 coastal processes, and at Belle Pass in particular. Prior to the dredging of the channel to Port Fourchon and
                 to the construction of jetties at the channel entrance, the coast east (updrift) of the channel was retreating at
                 a rate of 40 m/yr, compared to 31 m/yr west (downdrift) of the channel. The difference in retreat rates (30%
                 higher to the west) can perhaps be attributed to the channel's acting as a sediment sink in this predominantly
                 east-to-west littoral drift environment. After dredging and jetty construction, the difference between the east
                 and west erosion rates increased to 50 percent, although the magnitude of the retreat rate decreased by nearly
                 one half. In 1974, COE began to use material from maintenance dredging operations in Belle Pass to nourish
                 the beach areas west of the channel. Since then, no significant difference between east and west erosion rates
                 has been observed, and the absolute erosion rate has decreased by about another one half. The COE's
                 feasibility report for the Belle Pass deepening project indicates that some of the dredge material be used for
                 beach nourishment U.S. Dept. of the Army, COE, 1991). Based on this information, the expectation is that
                 there will be no increase in ongoing erosion rates of barrier islands and beaches is expected as a result of
                 channel deepening. No new infrastructure construction activity is projected to occur under the High Case
                 scenario (Section IV.A.3.a.).

                 Conclusion


                     The High Case scenario is not expected to result in permanent alterations of barrier beach configurations,
                 except in localized areas downdrift from navigation channels that have been dredged and deepened. The
                 contribution to this localized erosion is expected to be less than 1 percent.










                 IV-164

                 (b) Wetlands

                     The wetlands considered in this analysis include forested wetlands (swamps), tidal marshes, and seagrasses.
                 Swamps and marshes occur throughoutthe coastal zone. Seagrasses are restricted in distribution to small areas
                 behind barrier islands in Mississippi and Chandeleur Sounds. Impact-producing factors resulting from OCS
                 oil and gas activities that could adversely affect wetlands include oil spills, onshore discharge of OCS-produced
                 waters, pipeline placements, dredging of new navigation channels, maintenance dredging and vessel usage of
                 existing navigation channels, and construction of onshore facilities in wetland areas.
                     Numerous investigators have studied the immediate impacts of oil spills on wetland habitats in the Gulf
                 area. The often times seemingly contradictory impact assessment conclusions from these studies can at least
                 partially be explained by differences in the oil concentrations contacting vegetation, the kinds of oil spilled
                 (heavy or light crude, diesel, ftiel oil, etc.), the type of vegetation affected, the season of year, the preexisting
                 stress level of the vegetation, and numerous others factors. In general, however, the data suggest that, in the
                 absence of heavy offing, impacts will be short-term (plant dieback with recovery within two growing seasons
                 or less) and reversible, Le., the wetland area will be revegetated without artificial replanting (NVebb et al., 1985;
                 Alexander and Webb, 1987; Lytle, 1975; Delaune et al., 1979; Fischel et al., 1989).
                     The critical concentration of oil above which impacts to wetlands will be long term (greater than two
                 growing seasons) and irreversible (plant mortality and some permanent wetland loss) is cuirrently unknown.
                 A dearth of data exists on the long-term (three years or more) effects of oil spills on wetlands. This EIS
                 assumes that the off concentration that results in long-term, permanent impacts will depend on the wetland type
                 contacted. In the stressed environment of coastal Louisiana, where the wetland loss rate has been as high as
                 0.86 percent per year within the recent past, wetlands are assumed to be more sensitive to oil contacts than
                 elsewhere in the Gulf. The work of Mendelssohn and his colleagues (Fischel et al., 1989; Mendelssohn et al.,
                 1990) is providing data on the long-term effects of off spills on coastal marshes in Louisiana. The spill (a 300-
                 bbl spill from a pipeline rupture within the marsh) occurred in 1985. The response and recovery of the marsh
                 vegetation have been monitored since that time. The results of these investigations are used in this EIS to
                 develop assumptions about the anticipated effects of an oil spill on wetlands in the stressed environment of
                 coastal Louisiana.
                     Wetlands in the other coastal areas that could be contacted by an oil spill associated with Sale 142
                 (Mississippi, Alabama, and parts of Texas) are more stable and are not experiencing the wetlands loss problem
                 occurring in Louisiana. These Sale 142-associated wetlands occur on a more stable substrate, receive more
                 sediment per unit of wetland area, and have not experienced the alterations (canal dredging) that characterize
                 wetlands in Louisiana. The work of Webb and his colleagues (Webb et al., 1981 and 1985; Alexander and
                 Webb, 1983 and 1985) is used to evaluate the impacts of spills in these settings.
                     The following assumptions, based on the above studies, are being used to analyze the effects of oil spills
                 on coastal wetlands. In coastal Louisiana, it is assumed that the critical concentration of oil that will result in
                 long-term impacts to wetlands is 0.1 I/M2. Concentrations less than this value will cause dieNLck of the above-
                 ground vegetation for one growing season, but only limited mortality to the vegetation. Concentrations above
                 this value will result in 35 percent of the contacted vegetation experiencing either dieback or mortality. Within
                 4 years, 35 percent of this affected area will recover. Recovery will occur for 10 years. After 10 years, it is
                 assumed that 10 percent of the affected wetland area will have been permanently lost as a result of accelerated
                 landloss caused by the spill. If the spill contacts wetlands exposed to wave attack, additional accelerated
                 erosion of the wetland fringe will occur, as documented by Alexander and Webb (1987). Oil will persist in the
                 wetland soil for at least 5 years.
                     In more vigorous wetlands, such as along the Texas, Mississippi, and Alabama coasts, the critical
                 concentration is assumed to be 1.0 I/M2 (Alexander and Webb, 1983). Concentrations below this value will
                 result in short-term, above-ground dieback for one growing season. Concentrations above this, value will result
                 in longer-term impacts to wetland vegetation because some complete plant mortality will occur and these areas
                 will have to be recolonized. It is assumed that 50 percent of the contacted vegetation will dieback or be killed
                 after contact and that 10 years will.be required for complete recovery. In wetlands that border the coast or










                                                                                                                               IV-165

                  large estuaries, accelerated shore erosion will occur as a result of the weakened roots of the marsh vegetation
                  being unable to hold the soil against wave attack.
                      Seagrass vegetation has generally experienced minor damage from oil-spill occurrences (Zieman et al.,
                  1984; Chan, 1977). The relative insusceptibility of seagrasses, to off-spill impacts is partly the result of their
                  subtidal location, which protects them from direct contact with oil, and partly the result of seagrasses having
                  a large percentage of their biomass occurring as roots and rhizomes, which are buried in sedimenL The large
                  root mass allows the plants to regenerate from damage to their vegetative parts. The major impact to seagrass
                  communities from oil spills has been to the associated faunal assemblages.
                      It is expected that an oil spill that moves into a seagrass area will cause slight damage to the vegetation.
                  The impact will depend on the water depth in the affected area. Seagrasses generally occur at shallow depths
                  of 50 cin or less. Because of these shallow depths, it is expected that a spill contact will cause some seagrass
                  dieback for one growing season. No permanent loss of seagrass habitat will result from the spill. The faunal
                  community within the bed will also be affected in terms of-community composition and numbers of organisms.
                      Some produced waters generated on the OCS are transported via pipeline to land where they are treated
                  prior to disposal. Produced waters contain hydrocarbons, heavy metals, salts, and other contaminants that
                  could kill or damage contacted wetlands. Recent studies of the effects of produced water discharges in salt,
                  brackish, and fresh marsh areas in Louisiana have not documented any impacts from the discharges on
                  surrounding wetlands vegetation (Boesch and Rabalais, 1989b; Rabalais et al., 1991). This EIS assumes that,
                  over the life of the proposed action, all OCS-produced waters transported to shore will either be reinjected
                  or disposed of in nearshore open waters or in the Mississippi River and its passes, and will not affect coastal
                  wetlands (Section IV.A_3.c.(4)(a)). This observation has been confirmed by Boesch and Rabalais (1989b).
                      In addition to produced waters, some offshore drilling and production wastes are expected to be brought
                  to shore for disposal (Table IV-4). The onshore disposal of offshore wastes could affect wetlands if new
                  disposal sites are created in wedand areas or if seepage from waste sites occurs into adjacent wetland areas.
                      Pipeline projects in wetland areas have both direct and indirect impacts on coastal habitats. Today,
                  pipeline canals are backfilled after the pipeline is installed in its ditch. Backfilling, by partially filling in the
                  canal and leveling spoil banks, greatly reduces impacts caused by drainage alterations and encourages the
                  revegetation of the pipeline canal itself. A recent MMS study indicates that the average impact of a backfilled
                  canal results in 1.05 ha. of deteriorated or converted wetland per kilometer of pipeline on the Mississippi River
                  Deltaic Plain and 0.68 ha/kni on the Chenier Plain of Louisiana (Turner and Cahoon, 1987). In this analysis,
                  the figure for the Chenier Plain is assumed to apply to other areas of the Central Gulf (Mississippi and
                  Alabama) because of the firm substrate in these areas.
                      Pipeline installations'through seagrass beds affect the habitat due to direct losses from dredging and
                  indirect losses that result from turbidity effects and prop washing from pipe-laying barges.
                      Service vessels, pipelaying barges, and crude-off barges use navigation channels, some of which were
                  dredged or improved mainly for OCS development, to connect onshore facilities with offshore destinations.
                  The dredging of new navigation canals results in impacts to wetlands similar to the impacts associated with
                  open ditch (nonbackfilled) pipeline canals. The direct impacts of navigation channels have been estimated to
                  be 52 ha/km (Turner and Cahoon, 1987). Indirect impacts from navigation canals include saltwater intrusion
                  through the channel into fresher marsh areas, and drainage interruptions caused by spoil banks.
                      Additional impacts to wetlands can occur from periodic maintenance dredging of navigation channels and
                  the deepening of existing channels. If the spoil is deposited onto existing spoil banks, the effects of spoil banks
                  on wetland drainage.will be aggravated. The dredged material could also bury previously unaffected wetland
                  areas.
                      In addition, wakes generated by sale-related vessel traffic in navigation channels can cause channel bank
                  erosion and loss of wetlands. Although prop washing from vessel traffic resuspends sediments and increases
                  the turbidity of nearby coastal waters, navigation routes in the area are not located near seagrass beds.
                      Various kinds of onshore facilities have been constructed to service OCS development (Section W.A.).
                  The construction of these facilities in wetland areas could result in the conversion of wetland habitat to upland.










                 IV-166

                 Base Case Analysis

                     Oil spills associated with the proposed action can occur from a number of sources. Spills are expected to
                 occur offshore as a result of platform accidents or pipeline breaks. Spills can also occur inshore as a result of
                 barge or pipeline accidents, or during transfer operations at terminals.
                     According to Table IV-21, the probability of a spill of 1,000 or more bbl occurring and contacting within
                 10 days wetland areas under the Base Case ranges from less than 0.5 percent to 1.0 percent. Because of these
                 low probabilities, no spills greater than or equal to 1,000 bbl from offshore sources are assumed to contact
                 coastal wetlands. Further, no spills greater than or equal to 1,000 bbl from shuttle tankers in port are assumed
                 to occur (Table IV-16).
                     No spills greater than 50 and less than 1,000 bbI are assumed to occur and contact the coast (Section
                 IV.C.1). Twenty-one offshore spills greater than I and less than or equal to 50 bbl are assumed to occur, and
                 a few of these are assumed to contact the coaSt. Because of evaporation losses, spreading considerations, and
                 the fact that much of the remaining oil will wash onto barrier beaches that front the coast, contact from these
                 spills is not expected to result in high-enough concentrations of oil (greater than 0. 1 I/m2) on wetland surfaces
                 to affect wetland vegetation adversely. None of the oil is expected to contact seagrass beds located behind
                 barrier islands.
                     Fewer than 10 spills (Table IV4) greater than I and less than or equal to 50 bbl are assumed to occur
                 onshore or nearshore. No spills greater than 50 and less than 1,000 bbl are assumed to occur inshore (Table
                 IV4). The spills greater than 1 and less than or equal to 50 bbI are assumed to occur in coastal Louisiana,
                 where most OCS pipelines and oil terminals are located. Barge spills are estimated to occur near terminals.
                 In Louisiana, because nearly all navigation channels used by barge traffic have spoil banks, it is assumed that
                 most of the spilled oil will be confmed to the channel. The slick will be quickly transported and spread through
                 the channel by tidal and wind currents. The small amount of the oil transported onto wetland areas is not
                 expected to have adverse effects on wetland vegetation. The oil will have lost its identity as a slick by the time
                 that it could be transported near seagrass beds. No impacts to the beds are expected as a result of contact
                 from these low concentrations of oil.
                     Because pipelines traverse wetland areas in coastal Louisiana, a pipeline accident could result in oil directly
                 contacting wetland habitats. High concentrations of oil could contact limited areas of wetland vegetation as
                 a result of these spills. Fischel et al. (1989) have investigated the impacts of a 300-bbl pipeline spill in a
                 brackish marsh area of coastal Louisiana. Using this study site as a model, a 50-bbl spill could result in the
                 dieback and mortality of up to 2.7 ha of wetland vegetation. The assumptions developed in the introduction
                 to this analysis indicate that about 1 ha of these damaged wetlands will recover within four years. - About 0.3
                 ha of wetlands are expected to be lost permanently to open-water habitat as a result of th@ spill. Using the
                 data from Mendelssohn et al. (1990), the recovering vegetation is expected to be ecologically functionally
                 equivalent to the unaffected vegetation. The impacts from the spill will therefore be confined to a reduction
                 in plant density. Several such spills could result in 10-15 ha of wetlands damaged for up to ]bur years, and 2
                 ha converted to open water and mudflats over the 35-year life of the proposed action. Beatuse the pipeline
                 spill could occur within the interior of a wetland, the oil could persist in the soil for more than five years
                 because of the absence of wave-induced or tidal flushing.
                     Only one existing oil pipeline traverses Chandeleur and Mississippi Sounds in the vicinity of seagrass beds.
                 During the life of the proposed action, some of the oil developed in the CPA could be transported through
                 three additional pipelines assumed to be installed at the eastern end of Mississippi Sound as a result of
                 previous leasing activities. These locations, however, are not near seagrass beds. It is expected that no spills
                 will occur from these pipelines and affect seagrasses.
                     According to Table IV-4, 34 MMbbl of produced waters will be transported into Louisiana coastal waters
                 under the Base Case. Most of these produced waters will be brought into coastal Subarea C-3. These
                 produced waters will be either reinjected or discharged into nearshore open waters or the Mississippi River
                 and its passes. It is expected, therefore, that produced-water disposal will not affect wetland vegetation.
                     According to Table IV4, 69,000 bbl of produced sands and 744,000 bbI of drilling fluids will be transported
                 to shore under the Base Case scenario for disposal. According to an in-house analysis (Section IV.B.I.c.(3)(c)),
                 excess disposal capacity exists at operating disposal sites, and no new disposal sites will be required to










                                                                                                                            IV-167

                accommodate these wastes. Therefore, no wetland areas will be disturbed as a result of the establishment of
                new disposal sites. Some seepage from waste sites may occur into adjacent wetland areas and result in damage
                to wetland vegetation.
                    Pipeline landfall projects can affect wetland and seagrass habitats in a number of ways. Modern installation
                methods and planning procedures, however, have reduced levels of impacts associated with pipeline projects
                (Turner and Cahoon, 1987). Furthermore, no onshore pipeline projects are expected as a result of the Base
                Case scenario (Section IV.A.3.b.). Therefore, no impacts are expected.
                    Navigation channel impacts on wetlands are discussed in Section IV.A.3.(3). No new navigation channel
                dredging is anticipated (Section IV.A.3.c.(3)(c)); however, some maintenance dredging of existing channels will
                occur during the 35-year life of the proposed action. The disposal of dredged material could negatively affect
                wetlands if it is deposited onto existing banks or if previously unaffected wetland areas are buried by spoil
                banks. On the other hand, dredged material could also be used as a sediment supplement in deteriorating
                wetland areas to enhance wetland growth. The disposal of dredged material for marsh enhancement, however,
                has been done only on a limited basis, as of 1988 (Section IV.B.2.b.(I)). Given the increasing emphasis on
                using dredged material for marsh creation purposes, it is assumed that during the 35-year life of the proposed
                action, dredged material will be used to enhance wetland habitats. Maintenance dredging will also temporarily
                increase turbidity levels, which could deleteriously affect seagrasses. Major navigation canals, however, are not
                located near seagrass beds in the area. Furthermore, only 0.2 percent of channel usage will be accounted for
                by OCS vessels under the Base Case. Because of this small percentage of usage and the likelihood that much
                of the dredged material will be used to enhance wetland habitats, it is expected that no impacts will occur to
                wetlands from maintenance dredging.
                    As discussed in Section IV.A.3.c.(3), OCS activities in deep water are requiring larger service vessels for
                efficient operations. Currently, service bases in Galveston, Texas, and Berwick, Louisiana, are accessible to
                the larger vessels, and Empire and Cameron, Louisiana, are considered marginally usable. This document
                assumes that the channel through Belle Pass, Louisiana, to Port Fourchon will be deepened to 6.7 in (22 ft).
                The Corps of Engineers has completed a feasibility report for the project (U.S. Dept. of the Army, COE, 1991).
                According to the report, dredged material from the channel will be disposed of in wetland areas to enhance
                marsh creation. The COE expects 192 ha (479 ac) of saline marsh will be created. On the assumptions that
                90 percent of the justification of the project is for OCS activities and that the Base Case usage of channels
                represents 2 percent of the OCS Program usage of channels, 3.5 ha (8.6 ac) of wetlands will be created as a
                result of the Base Case scenario. The COE does not anticipate saltwater intrusion effects on wetlands as a
                result of the deepening project, probably because the project will be done in a saline environment where the
                existing vegetation is salt-tolerant.
                    Vessel traffic within navigation channels can cause channel bank erosion in wetland areas. An idea of the
                magnitude of OCS vessel traffic is provided in Table IV-6, which shows projected numbers of barge, service
                vessel, and shuttle tanker landings and dockings at various ports. Over the 35-year life of the proposed action,
                about 77 barge trips and 17,600 service vessel trips will occur within navigation channels. Additional vessel
                usage of navigation channels will be required for pipelaying barges and the movement of platforms to offshore
                locations. Most of this vessel traffic will use channels within the Louisiana coastal zone, where the impacts win
                be assessed. According to Johnson and Gosselink (1982), channels that have high navigational usage in coastal
                Louisiana widen about 1.5 m/yr more rapidly than channels that have little navigational usage (2.58 m/yr versus
                0.95 m/yr). The average distance along a channel to a service base and other OCS facilities is assumed to be
                25 kin. According to Table IV-6, there are 19 channels that are used by OCS vessel traffic associated with Sale
                142.
                    The OCS use of these channels will account for 0.2 percent of the total channel traffic. The estimate based
                on these figures is that 5.5 ha of wetlands will be eroded along channel banks during the 35-year life of the
                proposed action (1.4 ha/yr).
                    Thirty platform complexes are expected to be installed offshore as a result of the Base Case scenario
                (Table IV-2). The erosion of channel margins as a result of towing production structures through navigation
                channels is accounted for in the calculations in the previous paragraph. The possibility is analyzed here that
                future deep-water operations may require larger platforms that will cause greater amounts of channel bank
                erosion than has occurred in the past. As production moves into deep-water areas of the Gulf, the use of










                 IV-168

                 floating production systems, as opposed to fixed platforms, is being considered for developing I telds, particularly
                 those of marginal size that cannot support the great expense of fabricating a platform. The use of one such
                 floating production system is projected under the Base Case scenario for Sale 142. In addition, compliant
                 structures are being increasingly used for deep-water operations. These structures use tethering cables rather
                 than massive steel legs for anchoring the platform deck to the seabed. Towing the decks of these platforms
                 through coastal channels will not cause more erosion than towing a traditional platform. Furthermore, in
                 recent years some compliant structure decks have been purchased from overseas manufacturers. Given the
                 above considerations, this analysis does not expect increased erosion of wetlands from the towing of deep-water
                 structures through navigation channels.
                     No new construction of onshore infrastructure is anticipated (Section IV.A.3.a.). Therefore, no impacts
                 to wetlands from new construction projects are expected.

                 Summary

                     No oil spills greater than or equal to 1,000 bbl from offshore or inshore sources are assumed to occur and
                 contact within 10 days coastal wetlands under the Base Case scenario. Several smaller spills (greater than 1
                 and less than or equal to 50 bbl) are assumed to contact wetlands from inshore barge and pipeline accidents
                 or during transfer operations at terminals in coastal Louisiana. Only spills from pipeline accidents are expected
                 to result in high-enough concentrations of oil contacting wetlands to result in impacts. These @spills could result
                 in 10-15 ha of wetland vegetation being affected for up to 10 years, and as much as 2 ha of permanent wetlands
                 loss. Seagrass beds will be contacted by low concentrations of oil from these spills, and no impacts are
                 expected.
                     No new dredging projects for pipelines or navigation channels are projected. Few to no impacts from
                 maintenance dredging are expected given the small contribution of OCS vessel traffic to navigational usage of
                 the channels. Furthermore, alternative dredged material disposal methods that could be used to enhance
                 coastal wetland growth exist Deepening of one channel to accommodate larger service vessels is expected to
                 occur within a saline marsh environment. This project is expected to result in 3.5 ha of marsh creation
                 attributable to the Base Case scenario.
                     Erosion of wetlands from OCS vessel wakes is not expected to result in more than 5.5 ha of wetlands loss
                 during the 35-year life of the proposed action.

                 Conclusion

                     The proposed action is expected to result in dieback and mortality of 10-15 ha of wetlands vegetation as
                 a result of contacts from onshore oil spills. All but 2 ha of these wetlands will recover within 10 years; the
                 remaining 2 ha will be converted to open water. About 5.5 ha of wetlands are projected to be eroded along
                 channel margins as a result of OCS vessel wake erosion, and 3.5 ha of wetlands are projected to be created
                 as a result of beneficial disposal of dredged material from channel-deepening projects.

                 High Case Analysis

                     Oil spills associated with the proposed action can occur from a number of sources. Spills are expected to
                 occur offshore as a result of platform accidents or pipeline breaks. Spills can also occur inshore as a result of
                 barge or pipeline accidents, or during transfer operations at terminals.
                     According to Table IV-21, the probability of a spill greater than or equal to 1,000 bbl occurring and
                 contacting wetland areas within 10 days under the High Case ranges from less than 0.5 percent to 2.0 percent.
                 Because of these low probabilities, no spills greater than or equal to 1,000 bbl from offshore sources are
                 assumed to occur and contact within 10 days coastal wetlands. Further, no spills greater than or equal to 1,000
                 bbl from shuttle tankers in port are assumed to occur (Table IV-16).
                     No spills greater than 50 and less than 1,000 bbl are assumed to occur and contact the coast (Section
                 IV.C.1). Forty-seven offshore spills greater than 1 and less than or equal to 50 bbl are assumed to occur, and
                 a few of these are assumed to contact the coast. Because of weathering losses, spreading considerations, and





                                                                                        I










                                                                                                                             IV-169

                 the fact that much of the remaining oil will wash onto barrier beaches that front the coast, contact from these
                 spills is not expected to result in high-enough concentrations of oil (greater than 0.10 I/m2) on wetland surfaces
                 to affect wetland vegetation adversely. None of the oil is expected to contact seagrass beds located behind
                 barrier islands.
                     Fewer than 10 spills (Table IV-4) greater than 1 and less than or equal to 50 bbl are assumed to occur
                 onshore or nearshore. No spills greater than 50 and less than 1,000 bbI are assumed to occur inshore (Table
                 IV-4). The spills greater than 1 and less than or equal to 50 bbl are assumed to occur in coastal Louisiana,
                 where most OCS pipelines and oil terminals are located. Barge spills are expected to occur near terminals.
                 In Louisiana, because nearly all navigation channels used by barge traffic have spoil banks, it is expected that
                 most of the spilled oil will be confined to the channel. The slick will be quickly transported and spread through
                 the channel by tidal and wind currents. The small amount of the oil transported onto wetland areas is not
                 expected to have adverse effects on wetland vegetation. The oil will have lost its identity as a slick by the time
                 that it could be transported near seagrass beds. No impacts to the beds are expected as a result of contact
                 from these low concentrations of oil.
                     Because pipelines traverse wetland areas in coastal Louisiana, a pipeline accident could result in oil directly
                 contacting wetland habitats. High concentrations of oil could contact limited areas of wetland vegetation as
                 a result of these spills. Fischel et al. (1989) have investigated the impacts of a 300-bbl pipeline spill in a
                 brackish marsh area of coastal Louisiana. Using this study site as a model, a 50-bbl spill could result in the
                 dieback and mortality of up to 2.7 ha of wetland vegetation. The assumptions developed in the introduction
                 to this analysis indicate that about I ha of these damaged wetlands will recover within four years. About 0.3
                 ha of wetlands are expected to be lost permanently to open-water habitat as a result of the spill. Using the
                 data from Mendelssohn et al. (1990), the recovering vegetation is expected to be ecologically functionally
                 equivalent to the unaffected vegetation. The impacts from the spill will therefore be confined to a reduction
                 in plant density. Several such spills could result in 10-15 ha of wetlands damaged for up to four years, and 2
                 ha converted to open water and mudflats over the 35-year life of the proposed action. Because the pipeline
                 spill could occur within the interior of a wetland, the oil could persist in the soil for more than five years
                 because of the absence of wave-induced or tidal flushing.
                     Only one oil pipeline traverses Chandeleur and Mississippi Sounds in the vicinity of seagrass beds. During
                 the life of the proposed action, some of the oil developed in the CPA could be transported through three
                 additional pipelines assumed to be installed at the eastern end of Mississippi Sound as a result of pipeline
                 leasing activities. These locations, however, are not near seagrass beds. It is expected that no spills will occur
                 from these pipelines and contact seagrasses.
                     According to Table IV-4, 70.8 MMbbI of produced waters will be transported into Louisiana coastal waters
                 under the High Case. Most of these produced waters will be brought into coastal Subarea C-3. These
                 produced waters will be either reinjected or discharged into nearshore open waters or the Mississippi River
                 and its passes. It is expected, therefore, that produced water disposal will not affect wetland vegetation.
                     According to Table IV-4, 154,000 bbI of produced sands and 1,333,000 bbl of drilling fluids will be
                 transported to shore for disposal under the High Case scenario. According to USEPA information, sufficient
                 disposal capacity exists at operating disposal sites, and no new disposal sites will be required to accommodate
                 these wastes. Therefore, no wetland areas will be disturbed as a result of the establishment of new disposal
                 sites. Some seepage from waste sites may occur into adjacent wetland areas and result in damage to wetland
                 vegetation.
                     Pipeline landfall projects can affect wetland and seagrass habitats in a number of ways. Modern installation
                 methods and planning procedures, however, have reduced levels of impacts associated with pipeline projects
                 (Turner and Cahoon, 1987). Furthermore, no onshore pipeline projects are expected as a result of the High
                 Case scenario (Table IV-9). Therefore, no impacts are expected.
                     No new navigation channel dredging is anticipated (Section IV.A_3.c.(3)(c)); however, some maintenance
                 dredging of existing channels will occur during the 35@year life of the proposed action. The disposal of dredged
                 material could negatively affect wetlands if it is deposited onto existing banks or if previously unaffected
                 wetland areas are buried by spoil banks. On the other hand, dredged material could also be used as a
                 sediment supplement in deteriorating wetland areas to enhance wetland growth. As of 1988, however, the use
                 of dredged material for marsh enhancement has been done only on a limited basis (Section IV.B.2.b.(2)).










                 IV-170

                 Given an expected increasing emphasis on using dredged material for marsh creation purposes, it is expected
                 that, during the 35-year life of the proposed action, dredged material will be used to enhance wetland habitats.
                 Maintenance dredging will also temporarily increase turbidity levels, which could deleteriously affect seagrasses.
                 Major navigation canals, however, are not located near seagrass beds in the area. Only 0.4 percent of channel
                 usage will be accounted for by OCS vessels under the High Case. Because of this small percentage of usage
                 and the likelihood that much of the dredged material will be used to enhance wetland habimts, it is expected
                 that no impacts will occur to wetlands from maintenance dredging.
                     As discussed in Section IV.A.3.c.(3), OCS activities in deep water are requiring larger service vessels for
                 efficient operations. Currently, service bases in Galveston, Texas, and Berwick, Louisiana, are accessible to
                 the larger vessels, and Empire and Cameron, Louisiana, are considered marginally usable. This document
                 assumes that the channel through Belle Pass, Louisiana, to Port Fourchon will be deepened to 6.7 in (22 ft).
                 The Corps of Engineers has completed a feasibility report for the project (U.S. Dept. of the Ai-my, COE, 1991).
                 According to the report, dredged material from the channel will be disposed of in wetland areas to enhance
                 marsh creation. The COE projects that 192 ha (479 ac) of saline marsh will be created. On the assumption
                 that 90 percent of the justification of the project is for OCS activities, and that the Base Case usage of channels
                 represents 4 percent of the OCS Program usage of channels, 7 ha (17 ac) of wetlands will be created as a result
                 of the High Case scenario. The COE does not anticipate saltwater intrusion effects on wetlands as a result
                 of the deepening project, probably because the project will be done in a saline environmentwhere the existing
                 vegetation is salt-tolerant.
                    Vessel traffic within navigation channels can cause channel bank erosion in wetland areas. An idea of the
                 magnitude of OCS vessel traffic is provided in Tables IV4 and IV-6, which show projected numbers of barge,
                 service vessel, and shuttle tanker landings and dockings at various ports. Over the 35-year life of the proposed
                 action, about 178 barge trips and 30,850 service vessel trips will occur within navigation channels. Most of this
                 vessel traffic will use channels within the Louisiana coastal zone, where the impacts will be assessed. According
                 to Johnson and Gosselink (1982), channels that have high navigational usage in coastal Louisiana widen about
                 1.5 m/yr more rapidly than channels that have little navigational usage (2.58 m/yr versus 0.95 m/yr). The
                 average distance along a channel to a service base and other OCS facilities is assumed to be 25 km. According
                 to Table IV-6, there are 19 channels that are used by OCS vessel traffic associated with Sale 142. The OCS
                 usage of these channels is assumed to account for 0.4 percent of the total channel traffic. The estimate based
                 on these figures is that 11 ha of wetlands will be eroded along channel banks during the 35-year life of the
                 proposed action (2.8 ha/yr).
                    Fifty platform complexes are expected to be installed offshore as a result of the High Case scenario (Table
                 IV-2). The erosion of channel margins as a result of towing production structures through na%rigation channels
                 is accounted for in the calculations in the previous paragraph. The possibility is considered here that. future
                 deep-water operations may require larger platforms that will cause increased channel bank erosion compared
                 to the past. As production moves into deep-water areas of the Gulf, the use of floating production systems,
                 as opposed to fixed platforms, is being considered, particularly for fields of marginal size that cannot
                 economically justify a platform. The use of one such floating production system is projected under the High
                 Case scenario for Sale 142. Further, compliant structures are being increasingly used for deep-water
                 operations. These structures use tethering cables rather than massive steel legs for anchoring the platform deck
                 to the seabed. Towing the decks of these platforms through coastal channels will not cause more erosion.than
                 towing a traditional platform. Furthermore, in recent years some compliant structure decks have been
                 purchased from overseas manufacturers. From the above considerations, this analysis does not expect increased
                 erosion of wetlands from the towing of deep-water structures through navigation channels.
                    No new construction of onshore infrastructure is anticipated (Section IV.A.3.a.). Therelbre, no impacts
                 to wetlands from new construction projects are expected.

                 Conclusion

                    The High Case scenario is expected to result in dieback and mortality of 10-15 ha of wetlands vegetation
                 as a result of contacts from onshore oil spills. All but 2 ha of these wetlands will recover within 10 years; the
                 remaining 2 ha will be converted to open water. About 11 ha of wetlands are projected to be eroded along










                                                                                                                            IV-171

                 channel margins as a result of O-CS vessel wake erosion, and 7 ha of wetlands are projected to be created as
                 a result of beneficial disposal of dredged material from channel-deepening projects.

                 (2) Impacts on Sensitive Offshore Resources

                 (a) Live Bottonu (Pinnacle Trend)

                      Fifty-nine blocks are within the region defined as the pinnacle trend; approximately 28 are available for
                 lease. These live bottoms of concern in the northeastern portion of the Central Gulf and adjacent areas of the
                 Eastern Gulf are associated with the pinnacle trend, which is located between 73 and 101 m (240 and 330 ft)
                 water depths in the Main Pass and Viosca. Knoll lease areas. The pinnacles are scattered in this area and
                 include recently documented live-bottorn areas that may be sensitive to oil and gas activities. Leases in past
                 sales have contained a live-bottom stipulation for protection of such areas, and a proposed stipulation is
                 presented in Section II.Al.c.(2) as a potential mitigating measure for leases resulting from the proposed action.
                 The impact analysis presented below is for the proposed action and does include the proposed biological lease
                 stipulation.
                      A number of OCS-related factors may cause adverse impacts to the pinnacle trend communities and
                 features.
                      Damage caused by oil spills, blowouts, anchoring, structure emplacement and removal, drilling discharges,
                 and pipeline emplacement can cause the immediate death of numerous organisms or the alteration of
                 sediments to the point that recolonization of the affected areas may be delayed or impossible.
                      Oil spills have the potential to foul benthic communities and cause the death or disruption of organisms.
                 Oil from a surface spill can be driven into the water column, with measurable amounts documented at depths
                 approximating 20 m. At this depth, the oil is found only at concentrations several orders of magnitude lower
                 than the amount shown to have an effect on marine organisms.
                      Blowouts have the potential of resuspending considerable amounts of sediment and releasing hydrocarbons
                 into the water column, which may affect benthic communities. Subsurface blowouts can pose a threat to the
                 biota of the pinnacles if a blowout were to occur near one of these pinnacles. Blowouts can result in very high
                 concentrations of suspended sediments and increased levels of gas in the water column very near the source
                 of the blowout. Some oil or condensate may be present in the reservoir and may also be injected into the
                 water column. The suspended sediments may be carried some distance by currents, but the bulk of the
                 sediments is redeposited within a few hundred meters of the blowout site. A blowout within 100 rn of a
                 pinnacle community could result in the smothering of some biota within a limited area of a pinnacle due to
                 sedimentation.
                      The placement of anchors may damage lush biological communities or the structure of the pinnacles
                 themselves, which serve as attractors. Anchor damage from support boats and ships, floating drilling units, and
                 pipeline-laying vessels greatly disturbs areas of the seafloor and is the most serious threat to live-bottom areas
                 at these depths. The size of the affected area will depend on depth of water, length of chain, size of anchor
                 and chain, method of placement, wind, and current Anchor damage would include crushing and breaking
                 pinnacles and associated communities. Anchoring often destroys a wide swath of habitat when the anchor is
                 dragged or the vessel swings at anchor, causing the anchor chain to drag the seafloor.
                      The placement of drilling rigs and platforms on the seafloor will crush the organisms directly beneath the
                 legs or mat used to support the structure. The areas affected by the placement of the platforms and rigs win
                 predominantly be soft-bottom regions where the infaunal and epifaunal communities are not unique.
                      Both explosive and nonexplosive structure-removal operations will disturb the seafloor and can potentially
                 affect nearby pinnacle communities. Structure removal using explosives (the most common removal method)
                 can suspend sediments throughout the water column to the surface and may cause substantial impacts to nearby
                 habitats. Deposition of these sediments would occur much in the same manner as discussed for muds and
                 cuttings discharges. Explosive structure removals create shock waves, which could also harm resident biota in
                 the immediate vicinity.










                  IV-172

                      Drilling discharges affect biological communities and organisms through a variety of mechanisms.
                  Smothering of organisms through deposition of these sediments may occur, or less obvious sublethal eflects may
                  take place. Routine oil and gas operations discharge drilling muds and cuttings that will ciuse turbidity and
                  smothering of the benthos in proximity to the drill site. In the Gulf of Mexico OCS, about 90 percent of the
                  discharge settles rapidly, usually within 1,000 m of the discharge point.
                      Pipeline emplacement directly affects the benthic communities through burial and disruption of the
                  benthos, and through resuspension of sediments. These resuspended sediments may clog filter-feeding
                  mechanisms and gills of fishes and sedentary invertebrates. Pipeline emplacement also causes considerable
                  disruption to the bottom sediments in the vicinity of the pinnacles (Section IV.A-2.).

                  Base Case Analysis

                      The location of the pinnacles in the Central Gulf of Mexico is within offshore Subarea C-3. Table IV-2
                  provides information regarding the level of OCS-related activities in the vicinity of the pinnacles. This
                  information allows for a more detailed analysis of many of the impact-producing factors that have the potential
                  to affect the pinnacle communities. The information presented in the following discussion is derived from
                  Table IV-2.
                      For the purpose of this analysis, 21 spills greater than I and less than or equal to 50 bbl., one spill greater
                  than 50 and less than 1,000 bbl, and 1 spill greater than or equal to 1,000 bbl are assumed as a result of the
                  proposed action (Table IV-2). These surface spills would likely have no impact on the biota of the pinnacle
                  trend because the crests of these features are much deeper than 10 m.
                      For the purpose of this analysis, a single subsurface oil spill (6,500 bbl) is assumed to o(xur as a result of
                  the proposed action. While the probability of this spill occurring is 16 percent for the Central Gulf (Table
                  IV-19), the probability of the spill originating from a pipeline is lower (i.e., 9%; Table IV-19). The spin would
                  have to come in contact with a pinnacle feature, and few pipelines exist within proximity to the pinnacle region.
                  The biota of the pinnacles of the Central Gulf could be significantly impacted by a seafloor oil spill. The
                  spilled oil could impinge directly upon the pinnacles; impacts, including uptake of hydrocarbons or reduced
                  visibility, could then be serious to the local biota, even fatal. However, most of the biota would likely survive
                  and recover once the pinnacles were clear of the oil. The likelihood of a pipeline spill contacting a pinnacle
                  community is slight. These factors would serve to limit the extent of damage from any given spill. If a contact
                  were to occur, the severity would be slight.
                      Blowouts can pose a threat to pinnacle biota if one occurred nearby. A blowout within a 100 ni of a
                  pinnacle community could result in the smothering of the biota within a very limited area of a pinnacle due
                  to sedimentation. However, much of the biota is likely adapted to life in turbid conditions and, should impacts
                  occur, recovery of the community would be rapid.
                      Because of the hazardous nature of the pinnacle region to well-placement activities and because the
                  implementation of the proposed Live Bottom Stipulation will also minimize the proximity of wells to pinnacle
                  features, any potential blowouts would be a fair distance from the pinnacles.
                      Mechanical damage would be inflicted upon small portions of the benthic community by cDnducting routine
                  off and gas operations without benefit of the proposed biological stipulation in Section II.A_l.c.(2). Thedrilling
                  operation itself disturbs some small areas, and the anchor placement activities of the associated vessels would
                  cause damage to the pinnacle features and biological communities. Damage from rig and platform
                  emplacement could be devastating to small areas of the habitat provided by the pinnacles so affected and
                  would, in turn, affect the usefulness of the pinnacles as habitat or shelter for commercial and recreational
                  fishes. However, it is unlikely that a rig or platform would be emplaced directly on the pinnacles because of
                  the unevenness of the seafloor. For the purpose of this analysis, it is presumed that the Live Bottom
                  Stipulation, or some similar protective measure, would prevent oil and gas activities in the immediate vicinity
                  of the pinnacle communities. It is estimated that 10 platform complexes will be emplaced in offshore Subarea
                  C-3 (in which the pinnacles occur; Table IV-2) within the 35-year life of the proposed action. It is more likely
                  that most of the 10 platform complexes in offshore Subarea C-3 will not be located in water depths where
                  pinnacles are known to exist. For the same reasons, anchor damage from support boats and ships would be
                  minimal because of the implementation of the Live Bottom Stipulation in the pinnacle regions. Anchor










                                                                                                                            IV-173

                damage from support boats and ships, floating drilling units, and pipeline-laying vessels greatly disturbs areas
                of the seafloor and is the most serious threat to live-bottom areas. The size of the affected area will depend
                on depth of water, length of chain, size of anchor and chain, method of placement, wind, and current. Anchor
                damage would include crushing and breaking pinnacles and associated communities. Anchoring often destroys
                a wide swath of habitat when the anchor is dragged or the vessel swings at anchor, causing the anchor chain
                to drag the seafloor. However, as noted above, any platforms placed in this region would most often be sited
                to avoid such hazards for safety reasons. Such events may occasionally impact the resource.
                     Pipeline emplacement also has the potential to cause considerable disruption to the bottom sediments in
                the vicinity of the pinnacles (Section IV.A.2.). However, the implementation of the proposed Live Bottom
                Stipulation, or some similar protective measure, would severely limit oil and gas activities in the immediate
                vicinity of the pinnacle communities. For the purposes of this analysis, it is presumed that pipeline-laying
                activities would be prohibited in the proximity of live-bottom communities. It is estimated that 5,000 M3 Of
                sediment are resuspended per kilometer of pipeline in water depths shallower than 200 ft, disrupting a total
                of approximately 80,000    M3  (Table IV-2) in offshore Subarea C-3. However, it should be noted that data
                gathered for the ongoing MAMES study have shown the dense biological communities (i.e., live-bottom
                communities) to be concentrated on the pinnacle features themselves. The data show the extent of dense
                biological communities to be sparse in the bottom sediments surrounding the pinnacles, and the effect of
                pipeline-laying activities on the biota of the pinnacle communities would be restricted to the resuspension of
                sediments. For the purposes of this analysis, it is expected that enforcement of the Live Bottom Stipulation
                would minimize pipeline-laying activities through the pinnacle region. The severity of these actions has been
                judged, at the community level, to be slight, and impacts from these activities to be such that there will be no
                measurable interference to the general ecosystem.
                     Routine oil and gas operations discharge drilling muds and cuttings that will cause turbidity and smothering
                of the benthos in proximity to the drill sites. Estimates presented in Table IV-2 project 1,430,000 bbl of drilling
                muds and 344,000 bbl of drill cuttings generated from 205 exploration/delineation and development wells over
                the 35-year life of the proposed action in Subarea C-3. In the Gulf of Mexico OCS, about 90 percent of these
                discharges settle rapidly, usually within 1,000 m of the discharge points, and are rapidly diluted. Most
                water-based fluids are nontoxic, with their effects limited to the immediate vicinity of the discharge (NRC,
                1983). Deposition of drilling muds and cuttings on the pinnacle trend area would not significantly impact the
                biota of the pinnacles or the habitat itself. The biota of the seafloor surrounding the pinnacles are adapted
                to life in turbid conditions and to high sedimentation rates. Existing currents in the regions would prevent the
                adverse accumulation of muds and cuttings. The depth of water would dilute the effluent to a significant
                degree, and the pinnacles themselves are coated with a veneer of sediment. Additional deposition and turbidity
                caused by a nearby well are not expected to affect the pinnacle environment adversely because such fluids are
                discharged into very large volumes of water (the open Gulf of Mexico) and rapidly disperse, can be measured
                above background at only very short distances from the discharge point, and have little biological effect except
                very close to the discharge point. Such an event would rarely impact the resource because of the depth of the
                communities.
                     Removal of platforms substantially impacts nearby habitats. As previously discussed, the platforms are
                unlikely to be constructed directly on the pinnacles because of the restraints placed by the Live Bottom
                Stipulation. Impacts to the pinnacle area from structure removal are expected to be minimal because of the
                restricted regions affected by the shock from explosives and the low number of structures, (five removed
                explosively) in such regions. However, some localized damage may occur. Such an event would infrequently
                impact the resource because of the distance of platforms from pinnacles; the impact would be such that it
                would result in few losses of system elements, and recovery to preinterference conditions would be
                accomplished in a short term.

                Summary

                     Activities resulting from the proposed action are not expected to have a high level of impact on the
                pinnacle trend environment, because these activities would be restrained by the implementation of the Live
                Bottom Stipulation. The impact to the pinnacle trend area as a whole is expected to be slight because no










                  IV-174

                  community-wide impacts are expected. The inclusion of the Live Bottom Stipulation would preclude the
                  occurrence of the most potentially damaging of these activities. The action is judged to be infrequent because
                  of the limited operations in the vicinity of the pinnacles and the small size of many of the features. I)otential
                  impact levels from oil spills greater than or equal to 1,000 bbl, blowouts, pipeline emplaomment, mud and
                  cutting discharges, and structure removals are infrequent because of the proposed Live Bottom Stipulation.
                  The frequency of impacts to the pinnacles is rare, and the severity is judged to be slight because of the
                  widespread nature of the features.

                  Conclusion


                      The impact of the Base Case of the proposed action on the pinnacle region in the Gulf of Mexico is
                  expected to be such that any changes in the regional physical integrity, species diversity, or biological
                  productivity of the hard-bottom region would recover to pre-impact conditions in less than 2 years, more
                  probably on the order of 24 months.

                  Effects of the Base Case Without the Proposed Stipulation

                      Activities resulting from the proposed action, particularly anchor damage to localized pi[nnacle areas, are
                  expected to have a high level of impact on some individuals in portions of the pinnacle trend environment,
                  because these activities have the potential to destroy some of the biological communities and to damage one
                  or several individual pinnacles. However, the impact to the pinnacle trend area as a whole is expected to be
                  slight because no community-wide impacts are expected. The most potentially damaging of these are the
                  impacts associated with mechanical damages that may result from anchors. However, the action is judged to
                  be infrequent because of the limited operations in the vicinity of the pinnacles and the small size of many of
                  the features. Potential impacts from oil spills greater than or equal to 1,000 bbl, blowouts, pipeline
                  emplacement, mud and cutting discharges, and structure removals are infrequent. The frequency of impacts
                  to the pinnacles is rare because of the widespread nature of the features.

                  High Case Ana4uis

                     The pinnacles and the biota of the live-bottom areas would be subject to physical impact from rig
                  emplacement, platform and pipeline installation, and anchoring due to the increased level of activity over the
                  Base Case scenario. For the purposes of the High Case analysis, it is assumed that within the CPA (in which
                  portions of the pinnacle trend are located), 1 spill greater than or equal to 1,000 bbl, 2 spills greater than 50
                  and less than 1,000 bbl, and 47 spills greater than 1 and less than or equal to 50 bbl will occur over the 35-year
                  life of the proposed action. The offshore infrastructure estimates (wells and platforms) are slightly greater in
                  this scenario (205 wells and 10 platform complexes under the Base Case and 365 wells and 18 platform
                  complexes for the High Case in Subarea C-3), as are the lengths of pipeline installed (80 kni for the Base Case
                  and 144 km for the High Case) and the volume of drilling mud discharges (1,430,000 bbl for the Base Case
                  and 2,535,000 bbl for the High Case). However, an MMS in-house analysis of proprietary data finds it more
                  likely that most of these activities in Subarea C-3 will not be located in water depths where pinnacles are
                  known to exist. The oil-spill occurrence probability from pipelines of one or more oil spiDs of 1,000 bbl or
                  greater is estimated at 19 percent for the High Case (Table IV-17). Thus, the possibility of an oil spill will be
                  greater than that of the Base Case. However, the implementation of the Live Bottom Stipulation would
                  minimize operations occurring near a sensitive offshore habitat. The frequency of these types of events is
                  judged to be occasional.

                  Conclusion

                     The impact of the High Case scenario for the proposed action on the pinnacle trend region is expected
                  to be such that any changes in the regional physical integrity, species diversity, or biological productivity of the










                                                                                                                            IV-175

                 hard-bottom region would recover to pre-impact conditions in less than 2 years, more probably on the order
                 of 24 months.

                 (b) Deep-water Benthic Communities

                     The deep-water benthic communities consist of recently discovered organisms that are apparently most
                 abundant in water deeper than 400 m (1,312 ft) and that derive their energy, in the absence of light, from
                 chemosynthetic: processes rather than the photosynthetic processes of shallow water (see Section III.B.2.b. for
                 a more detailed discussion of these communities). The primary chemosynthetic organisms are bacteria, both
                 free-living (as "bacterial mats") and symbiotic in the tissues of other organisms, especially in the gins. The
                 predominant large animals are tube worms, clams, and mussels. The only impact-producing factor threatening
                 these communities results from those activities that would physically disturb the bottom, such as the routine
                 operations of anchoring, drilling, and pipeline installation, and the seldom occurring seafloor blowout accident
                 Because of the great water depths, routine oil and gas effluent discharges such as muds, cuttings, and sanitary
                 wastes will not cause any deleterious impacts to chemosynthetic communities due to the rapid dilution and
                 dispersion of effluent components (in shallower depths, cuttings tend to form a low mound or to be worked
                 into the surrounding sediments, depending upon the nature of the local sediments, depth of disposal, and
                 physical forces acting upon the pile). In these deep waters, such discharges rapidly disperse, can be measured
                 above background at only very short distances from the discharge point, do not build up on the bottom, and
                 have little biological effect except very close to the discharge point Because these communities use petroleum
                 hydrocarbons as a food source (and indeed have been seen to be living among oil and gas bubbles), oil spills
                 are not considered to be a potential source of adverse impacts. Thus, oil spills will have no impact on these
                 communities.
                     The greatest potential for adverse impacts to occur to deep-water chemosynthetic communities would come
                 from those OCS-related, bottom-disturbing activities associated with pipelaying (Section IV.A_2.b.(I)),
                 anchoring (Section IV.A.2.d.(1)(b)), and structure emplacement (Section IV.A.2.d.(1)(a)), as well as a seafloor
                 blowout (Section IV.A_2.d.(8)). These activities cause localized bottom disturbances and disruption of benthic
                 communities in the immediate area of the drilling. Considerable mechanical damage would be inflicted upon
                 the bottom by routine OCS drilling activities. The drilling operation itself disturbs a small bottom area. The
                 presence of a conventional structure can cause scouring of the surficial sediments (Caillouet et al., 1981). It
                 is assumed that 2 ha (5 ac) of bottom is disturbed by platform emplacement in water depths less than 457 m
                 (1,500 ft), and 4 ha (10 ac) in depths greater than 457 m. Anchors from support boats and ships (or, as
                 assumed in these water depths, from any buoys set out to moor these vessels), floating drilling units, and
                 pipelaying vessels also cause severe disturbance to small areas of the seafloor. The area affected will depend
                 on the water depth, length of the chain, size of the anchor, and current. Anchoring will destroy those sessile
                 organisms actually hit by the anchor or anchor chain during anchoring and anchor weighing. While such an
                 area of disturbance may be small in absolute terms, it may be large in relation to the area inhabited by
                 chemosynthetic organisms. Normal pipelaying activities in deep-water areas consist of laying the pipe along
                 the seafloor (it is assumed that 0.32 ha (0.8 ac) of bottom is disturbed per kilometer (0.6 mi) of pipeline
                 installed), a practice that could destroy large areas of chemosynthetic organisms. It is likely that pipelines win
                 be used to transport the product ashore from those deep-water areas in proximity to the current pipeline
                 network in both the Central and the Western Gulf. In areas not near the existing pipeline network, shuttle
                 tankering will substitute for pipelines as a means of transporting the product; therefore, impacts to these deep-
                 water communities from this type activity would be precluded in the more isolated areas.
                     A blowout at the seafloor could resuspend large quantities of bottom sediments and even create a large
                 crater, destroying any organisms in the area.
                     The majority of the deep-water benthic chemosynthetic communities are of low density and are widespread
                 throughout the deep-water areas of the Gulf, so disturbance or destruction of a small area would not result
                 in a major impact to chemosynthetic communities as an ecosystem. Areas so impacted could be repopulated
                 from nearby undisturbed areas.










                IV-176

                     High-density, Bush Hill-type communities are areas of high biomass and, while tittle is Imown at present
                of the size, number, or locations of these important communities, it is known that they arc: associated with
                hydrocarbon seeps and gas- and/or oil-charged sediments. It is these chemosynthetic areas that are considered
                to be most at risk from oil and gas operations. The disturbance of a Bush Hill-type community could lead to
                the destruction of the community such that recovery would not soon occur or would not occuir at all. Because
                of the recent discovery of this type community, the vulnerability to impact, recoverability, and general extent
                of the community are unknown. Notice to Lessees (NTL) 88-11 (which became effective on February 1, 1989)
                formalizes the MMS review process and makes mandatory the search for and avoidance of "plush"
                chemosynthetic communities (such as Bush Hill-type communities) or areas that have a high potential for
                supporting these community types, as interpreted from geophysical records. Under the provisions of this NTL,
                lessees operating in water depths greater than 400 m (1,312 ft) are required to interpret the geophysical records
                of that area for conditions that might indicate that the area may support chemosynthetic cornmunities; if such
                conditions exist, the lessee must either move the operation or provide photo-documentation of the presence
                or absence of chemosynthetic communities (of the Bush Hill type). If such communities are indeed present,
                no drilling operations may take place in the area (if the communities are not present, drilling may proceed).
                The requirements set forth in NTL 88-11 are considered to be very effective in identifying areas of
                chemosynthetic communities, but some small percentage (estimated by MMS to be on the order of 10-15%)
                of chemosynthetic community areas may not be properly identified by these procedures. As new information
                becomes available, the NTL will be modified as necessary.
                     It should be noted that NTL 88-11 is a nonsale-specific mitigation measure that is applied to all operations
                in appropriate water depths. These activities must conform to the protective measures outlined in the NTL
                and summarized above. Because of the administrative nature of an NTL, it is exercised on all applicable leases
                and is not an optional protective measure at the discretion of the Secretary of the Interior.                 The
                implementation of an NTL is unlike the stipulations proposed within this document. The stipulations are sale-
                specific protective measures that are applied to specific leases and that may or may not be adopted by the
                Secretary at each lease sale.
                     These NTL's, along with many other Federal regulations and MMS operational guidelines (as outlined in
                Section I.B.), form the framework within which operators in the Gulf of Mexico function. The thousands of
                plans, modifications, reports, and papers that document the efforts of the OCS oil and gas industry follow the
                framework established by MMS; NTL 88-11 is but one piece of this extensive guidance.
                     Am issue about which little is known, but about which there has been some speculation, is the potential
                impact to chemosynthetic organisms by the withdrawal (by oil and gas production) of the energy source--the
                hydrocarbons--from beneath the community. The seeps and vents around which these animals live are
                presumably pressurized from the deep reservoirs that force the gas or oil to the seafloor. When all of the
                recoverable hydrocarbons from these reservoirs are withdrawn by production operations, it is possible that oil
                and gas venting or seepage would also slow or stop. Current information does not allow a determination to
                be made as to whether this slackening of the pressure, which drives the seeps, would be reduced quickly (as
                they have been on land) or whether there may be enough oil already in the "conduit" to the suirface to continue
                the seepage for long periods. Such long-term impacts are poorly understood, but the level of development in
                deep-water areas may be too low to cause significant impacts from the depletion of the hydrocarbon energy
                source. Current and planned studies of these communities by MMS may provide information that will lead
                to the resolution of this issue.


                Base Case Ana4vis

                     Because high-densitychemosynthetic communities are found only in water depths greater than 400 m (1,312
                ft), they will not be found in Subarea C-1; they will be found only in the southeast third of Subarea C-2 and
                the southern two-thirds of C-3; and they may be found throughout C4. Thus, these communities will not be
                exposed to the full level of projected impact-producing factors of Table IV-2. As noted in Table IV-2, in these
                three subareas a total of 545 wells are assumed to be drilled, 24 platform complexes installed,and 192 km (120
                mi) of pipeline installed.










                                                                                                                            IV-177

                     As noted above, the majority of these deep-water communities are of low density and are widespread
                throughout the deep-water areas of the Gulf. Disturbance to a small area would not result in a major impact
                to the ecosystem. For purposes of this Base Case analysis, the frequency of such impact is expected to be once
                every six months to two years, and the severity of such an impact is judged to result in few losses of ecological
                elements, with no alteration of general relationships.
                     High-density communities are, as noted above, largely protected by the provisions of NTL 88-11. For
                purposes of this analysis, the frequency of some small percentage of impact is expected to be once every six
                months to two years, but the severity of such an impact is such that there may be some loss of ecological
                elements and/or some alteration of general relationships.

                Summary

                     The only impact-producing factor threatening the chemosynthetic communities is physical disturbance of
                the bottom, which would destroy the organisms comprising these communities. Such disturbance would come
                from those OCS-related activities associated with pipelaying, anchoring, structure emplacement, and seafloor
                blowouts. Only structure emplacement is considered to be a threat, and then only to the high-density (Bush
                Hill-type) communities; the widely distributed low-density communities would not be at risk. The provisions
                of NTL 88-11 (currently in effect), requiring surveys and avoidance prior to drilling, will greatly reduce, but not
                completely eliminate, the risk.

                Conclusion

                     The proposed action is expected to cause little damage to the physical integrity, species diversity, or
                biological productivity of either the widespread, low-density chemosynthetic communities or the rarer, widely
                scattered, high-density Bush Hill-type chemosynthetic communities. Recovery from any damage is expected
                to take less than two years.

                High Case Ana4uis

                     In the High Case analysis, the deep-water benthic communities (e.g., chemosynthetic communities) would
                be subject to the same impact-producing factor as in the Base Case: physical disturbance of the bottom where
                these communities are found, such as disturbance by emplacement, platform and pipeline installation, and
                anchoring. No other impact-producing factor is expected to present a threat to these deep-water communities.
                As noted under the Base Case, it is highly unlikely that discharges from the proposed activities would adversely
                impact the benthos in the water depths (greater than 400 m) being discussed, due to the rapid dilution and
                dispersion of effluent components.
                     Furthermore, as in the Base Case, these communities will be found only in the southeast third of Subarea
                C-2 and the southern two-thirds of C-3, and they may be found throughout CA Thus, these communities will
                not be exposed to the full level of the projected impact-producing factors of Table IV-2. As noted in Table
                IV-2, in these three subareas a total of 980 wells are assumed to be drilled, 44 platform complexes installed,
                and 400 km (250 mi) of pipeline installed.
                     While the opportunities for impact are somewhat higher for this High Case than for the Base Case, NTL
                88-11 will still be effective in detecting the high-density communities and providing for their avoidance.
                     For purposes of this analysis, the frequency of such impact to the widespread, low-density communities is
                expected to be once every six months to two years, and the severity of such an impact is judged to result in few
                losses of ecological elements, with no alteration of general relationships.
                     For purposes of this analysis, the frequency of some small percentage of impact (given NTL 88-11) to high-
                density communities is expected to be once every six months to two years, but the severity of such an impact
                is such that there may be some loss of ecological elements and/or some alteration of general relationships.










                 IV-178


                 Conclusion


                     The activities associated with the High Case scenario are expected to cause little damage to the physical
                 integrity, species diversity, or biological productivity of either the widespread, low-density chemos, thetic
                                                                                                                          Yn
                 communities or the rarer, widely scattered high-density, Bush Hill-type chemosynthetic communities. Recovery
                 from any damage is expected to take less than two years.

                 (c) Topographic Features

                     The topographic features of the Central Gulf providing sensitive offshore habitats are listed and described
                 in Section III.B.2.
                     A Topographic Features Stipulation similar to the one described in Section II.A. 1.c.(1) has been included
                 in appropriate leases since 1973 and may, at the option of the Secretary, be made a part of appropriate leases
                 resulting from this proposal. The impact analysis presented below is for the proposed action and includes the
                 proposed biological lease stipulation. As noted in Section ILAA.c.(1), the stipulation establLshes an area (No
                 Activity Zone) in which no bottom-disturbing activities would be allowed and areas around the No Activity
                 Zone's (in most cases) in which shunting of all drill effluents to near the bottom would be required. The
                 effectiveness of the stipulation in protecting the biota of the topographic features (banks) is well documented.
                 Thus, the very high potential impacts described in previous EIS's for the biota of the banks, and which did not
                 include the protective stipulation in the analysis of the proposed action, would not occur as a result. of this
                 proposal.
                     The potential impact-producing factors to the topographic features of the Central Gulf are anchoring
                 (Section IV.A_2.d.(1)(b)), structure emplacement (Section IV.A.2.d.(1)(a)), effluent discharge (Section
                 IV.A.2.d.(5)), blowouts (Section IV.A_2.d.(8)), oil spills, (Sections IV.A-2.d.(10) and W.C.), and structure
                 removal (Section IV.A.2.a.(3)).
                     Anchoring of pipeline lay barges, drilling rigs, or service vessels, and structure emplacement (pipeline,
                 drilling rig, or platform emplacement) results in physical disturbance of the benthic environment. Anchor
                 damage has been shown to be the most serious threat to the biota of the offshore banks (Bright and Rezak,
                 1978; Rezak et al., 1985). However, the stipulation discussed above would preclude these activities in the No
                 Activity Zone, thus preventing adverse effects from this factor.
                     Drilling mud and cutting discharges result in localized water turbidity, deposition on the surrounding
                 seafloor, and potential effects of the low concentrations of toxic constituents. Some 7,134 bb). of drilling muds
                 (on average) are assumed to be discharged per exploration well, and 6,749 bbl per development well; 1,853
                 bbI of cuttings are produced per exploration well, and 1,430 bbl per development well. Nearly 82 percent of
                 these amounts are assumed to be generated offshore, with the rest brought to and disposed of onshore.
                 Formation waters are routinely discharged during production operations. Some 450 bbI are : roduced per oil
                                                                                                                1P
                 well per day, and 68 bbI per gas well per day; 89 percent is assumed to be discharged directly offshore. Oil
                 and gas operations will routinely discharge drilling muds and cuttings, which may impact the Nota of the banks
                 due to turbidity and sedimentation. Most water-based fluids are relatively nontoxic, and their effects are limited
                 to the immediate vicinity of the discharge (NRC, 1983). (The more toxic oil-based muds, if used, cannot be
                 discharged under the conditions of the Environmental Protection Agency's NPDES permit.) The water depths
                 from which the topographic features rise range from 50 to 175 m, depths that dramatically increase the dilution
                 of drilling effluents. In the Gulf of Mexico OCS, about 90 percent of the discharge settles, rapidly, usually
                 within 1,000 m (NRC, 1983). Choi (1982) found that drilling discharges (muds and/or cuttings with iron flakes)
                 were trapped in coral and coral rubble only up to 100 m from the wellhead; even so, coelobite communities
                 therein were largely disturbed only up to 40 m from the drill site, with minor changes evident out to 100 m.
                 Coring conducted by Hudson et al. (1982) on coral heads near drilling activities on a Philippine coral reef
                 revealed little suppression of head coral growth due to drilling, while diver observations noted. a 70-90 percent
                 reduction of coral cover in a 115-by-85 m ellipse; coral cover beyond this small area was the same as control
                 areas. Effluents discharged at the water's surface within 1,000 m of a bank could impact the biota of the bank,
                 although the currents at the banks would tend to keep the bank swept clean of fine sediments and would










                                                                                                                            IV-179

                prevent the accumulation of drilling muds at the bank. Produced water, which is relict seawater associated with
                produced hydrocarbons, along with injection water and other additives, may be a potential hazard to the biota
                of topographic features. It contains high concentrations of inorganic salts ranging from 3 to 300 parts per
                thousand (ppt). Hydrocarbons, other organic compounds, and trace metals may be present in parts per minion
                (ppm) levels in the produced water discharges. The study of the Buccaneer off field offshore Texas (USDOC,
                NMFS, 1977) determined that produced water was discharged at a rate of 32 M3 per day between January 1975
                and February 1976. The average oil content of this produced water was 25.1 ppm. However, the latest API
                average oil and grease content in OCS produced waters (after treatment) is 89 ppin (USEPA, 1991), and the
                mean discharge rate of treated produced waters in the Gulf is 286 in   3 per day (Walk, Haydel, and Associates,
                Inc., 1984). Near-platform macrobenthic populations were depressed and had a high turnover rate as
                compared to the surrounding sea bottom; this may have been a result of increased scour action around the
                platform structure itself, but no cause-effect relationship was established. However, the proposed stipulation
                discussed above would preclude these activities in the No Activity Zone and would require shunting of these
                discharges in zones around the high relief banks, thus preventing adverse effects from this factor to the biota
                of the banks. Section IV.A.2.d.(5)(b) provides more information on produced waters in the Gulf of Mexico.
                    Blowouts can occur from either oil or gas wells. Off well blowouts may result in oil spills. Both gas and
                oft subsurface well blowouts result in large amounts of bottom sediment being resuspended in the water
                column. The resuspension of sediments disturbed during a subsurface blowout can result in localized water
                turbidity and deposition of the materials on the surrounding seafloor, which may in turn cause the smothering
                of local benthic communities or induce stress in part or all of a local community. An additional potential
                harmful effect could be caused by concentrations of toxic constituents that may be in the sediments (from
                contaminated river runoff, for example). To the extent that oil or condensate is present in the reservoir, some
                liquid hydrocarbons may also be injected into the water column. The suspended sediments may be carried
                some distance by currents, but the bulk of the sediments is redeposited within a few thousand meters of the
                blowout site. Low-molecular-weight hydrocarbons (gases) will dissolve in the water column until saturation is
                reached. A blowout directly on a bank or near a bank could have serious long-term or permanent
                consequences. In most cases, it is expected that the currents will sweep the contaminants around the bank
                rather than deposit them on the bank (Rezak et al., 1983). Some small fraction of the sediments or oil may
                reach a bank and come in contact with organisms; the extent of damage will depend on the amount of
                contaminant and the length of time it remains on the bank. Amounts are not expected to be high because of
                dilution, dispersion, settling, and current action (sweeping the contaminant around and from the bank). Length
                of time on the bank may be long for the heavier sediments, but these are likely to settle out rapidly and not
                reach the bank at all (Brooks and Bernard, 1977). The stipulation discussed above would preclude drilling in
                the No Activity Zone, thus preventing most adverse effects from blowouts.
                    Oil spills may occur at the surface due to tanker spillage and platform spills or at the seafloor due to
                pipeline rupture or well blowout. Both surface and subsurface spills could result in a steady discharge of oil
                over a long period of time. Surface spills could occur from tankers or oil platforms. Most of the small spills
                would occur from surface sources. The spills less than 1,000 bbl and spills grater than or equal to 1,000 bbl
                are as equally estimated to result from surface spills as seafloor spills. Oil from a surface spill can be driven
                into the water column; measurable amounts have been documented at depths approximating 10 in, although
                modeling exercises have indicated such oil may reach a depth of 20 in. At this depth, the oil is found only at
                concentrations several orders of magnitude lower than the amount shown to have an effect on corals (Lange,
                1985; McAuliffe et al., 1975 and 1981; Knap et al., 1985). Because of the water depths in which topographic
                features are found, no oil from a surface spill will reach the biota of concern. Oil from a subsurface spin
                (pipeline spill), which is the Pipe of spill assumed for this proposed action (Section W.C.), could reach the biota
                of concern on a topographic feature. Impacts could then be serious to the local biota actually contacted by
                the oil. Destruction of the biota of such areas may have severe and long-lasting deleterious consequences on
                the specific commercial and recreational fishery habitats affected. These consequences include loss of habitat,
                loss of species (including prey species), destruction of hard substrate, and change in sediment characteristics,
                all of which may result in the reduction or loss of one or more fisheries. These areas also have intrinsic
                biological, ecological, and aesthetic values of their own that would be lost by such activities. Corals, however,
                would probably not be impacted this severely. Knap et al. (1985) found that Diploria stfigosa dosed with oil










                   IV-180

                   exhibited sublethal effects that occurred rapidly-, effects were short-term, and recovery of @the coral was also
                   rapid. Additionally, Diplofia appears to be relatively tolerant of brief exposures to chemically dispersed crude
                   oil. Nonchemically dispersed off adhered longer to the substrate; the exposure time of coral to oil would be
                   lengthened, thereby increasing the impacts. Of note is the fact that the cryptic fauna associated with the coral
                   community may be more sensitive to oil dosage than the corals. Such a blowout and spill event, however, are
                   quite unlikely. The stipulation discussed above would preclude drilling in the No Activity Zone, thus preventing
                   adverse effects from nearby drilling. However, it is possible that off spills originating outside the No Activity
                   Zones could reach the area of the banks. Because of the depth of the banks, it is unlikel@ that the biota of
                   the banks would be affected by subsurface oil.
                       The following is a brief summary of recent pertinent work on the effects of oil on coral:

                                A review of the literature reveals conflicting results regarding the effects of off on corals.
                           However, most researchers agree that the evidence suggests a detrimental influence of oil
                           contamination on reef corals. Differences in experimental design and the variability of field.
                           conditions must be noted whenever such comparisons are made (Dodge et al. 1984). For
                           example, it may be misleading to draw conclusions on the long-term damage to cc)ral reefs,
                           from studies based on short-term or qualitative observations (Loya and Rinkevich 1980).
                                In 1986 a major spill occurred in an area along the Caribbean coast of Panama which had
                           previously been well characterized ecologically. This has provided an unprecedented
                           opportunity for the study of both the acute and the chronic impacts of oil on tropical marine
                           communities (Keller and Jackson 1991), including coral reefs (Guzman et al. 1991; Guzman
                           and Jackson 1991). The results are for the most part in agreement with previous work
                           regarding the effects of oil spills on shallow reefs, demonstrating that growth rates, population
                           levels, total coral cover, and species diversity decreased significantly in the shallow subtidal
                           areas where the reefs were exposed to oil.       Coral tissue samples, taken following-, the 1986
                           oil spill, indicated levels of oil on the order of 25 to 50 ug/mg lipid in specimens from a
                           heavily oiled site (Bums and Knap 1989). However, samples taken in 1988 and 1989,
                           demonstrated that the levels of oil in coral tissues were extremely low (<I ug/mg vxtractable
                           organic matter) (Burns, in press).
                                While such coral species as Montastrea annularis, Porites astreoides, and Diploha s1figosa
                           are common to both he reefs of the Gulf such as the Flower Garden Banks and the reefs of
                           Panama, the habitats differ markedly regarding such parameters as depth, distance from shore,
                           and hydrography (Rezak et al. 1985; Jackson et al. 1989). While the reefs which were
                           impacted in Panama are fringing reefs within a few tens-of-meters of the shoreline and include
                           shallow reef-flats coming to the waters surface, the coral reefs of the Flower Garden Banks
                           come only to within 18 m of the surface and are over 200 kin from shore. The reefs of'
                           Panama are also heavily influenced by sedimentation and freshwater runoff from the
                           mangrove forests directly adjacent to them, such coastal influences are not encountered in the
                           much more oceanic environment of the Flower Garden Banks.
                                The Flower Garden Banks, lacking shallow water reef structures (e.g., reef flat,emergent
                           reefs, etc.) are much less at risk from buoyant surface-bound slicks than are the more typical
                           shallower reefs found throughout the Caribbean. However, it may be argued that the severing
                           of a submerged pipeline would introduce petroleum into the water column which, under the
                           proper conditions, may result in the formation and settling of oil-saturated material with off-
                           sediment particles coming into contact with living coral tissue.
                           Bak and Elgershuizen (1976) examined the patterns of oil-sediment rejection of 19 Caribbean
                           hermatypic corals and found that physical contact with such particles was less harmful to
                           corals than the toxic effects of oils. These experiments included the most important
                           hermatypic corals of the Flower Garden Banks: Montastrea annularis, Diploria svigosa, M.
                           cavemosa, Colpophyffia spp., and Pofites astreoides (Bright et al. 1974, 1984; Tresslar 1974;
                           Viada 1980; Kraemer 1982).










                                                                                                                           IV-181

                                      The use of chemical dispersants might also cause a surface slick to sink, exposing deeper
                                  reef environments to oil contamination. However, studies of chemically treated oil slicks
                                  under field conditions report subsurface dispersed oil concentrations ranging from less than
                                  1 ppm to a maximum of 20 to 70 ppm; concentration exceeding 10 ppm are usually restricted
                                  to the upper 2 to 3 in of the water column (e.g., McAuliffe et al. 1981; Lichtenthaler and
                                  Daling 1983, 1985; Delvigne 1985; Gill et al. 1985; Nichols and Parker 1985).
                                      Dodge et al. (1984) exposed colonies of D. svigosa for 6-24 h periods to various
                                  concentrations (1-50 ppm) of oil or chemically dispersed off. These experiments were
                                  designed to assess the long-term effects of brief low-level concentrations of chemically
                                  dispersed oil and oil alone on corals in situations similar to that which may occur when oil
                                  slicks (treated and non-treated) passed over a reef. No significant differences between the
                                  treated corals and controls were found in any of the experiments. However, as explicitly
                                  stated by the authors, these experiments did not attempt to access chronic pollution from, for
                                  example, a slow leak from a grounded tanker or a pipeline. However, the experimental
                                  conditions used do fall within the worst case scenario (concentrations and time) which might
                                  be encountered in the event of a severing of a pipeline.
                                      Wyers et al. (1986) examined the behavior of D. stfigosa during 6 to 24 hour exposures
                                  to water-accommodated fractions of chemically and physically dispersed crude oil. In general,
                                  effects observed were sub4ethal, temporary, and only associated with the highest
                                  concentrations tested. Behavioral observations provided little evidence of adverse effects at
                                  1-5 ppm concentrations. At 20 ppm, responses included mesenterial filament extrusion;
                                  extreme tissue contraction; tentacle retraction; and in certain experiments, localized tissue
                                  rupture. The nature and severity of reactions during the dosing phase varied between colonies
                                  and treatments, but colonies typically resumed normal behavior within 2 hours to 4 days. It
                                  was concluded that these observed biological effects would be unlikely to impair long-term
                                  viability.
                                      These studies suggest that when the symptoms elicited by physically or chemically
                                  dispersed oil are temporary, they appear to be within the scope of naturally occurring
                                  defensive reactions to adverse conditions (Wyers et al. 1986). For example, extreme tissue
                                  contraction can be elicited by physical factors and may give rise to rupture as the tissue is
                                  withdrawn into the underlying corallum (Kanwisher and Wainwright 1967; Hubbard 1974).
                                  Tentacle retraction occurs in response to such stimuli as temperature extremes (Jokiel and
                                  Coles 1977) and high current velocities (Hubbard 1974). Mesenterial filament extrusion is
                                  usually reported under conditions of surface tissue damage or irritation, although it can also
                                  play a role in feeding activities (Lewis and Price 1975) and interspecific competition (Lang
                                  1973). Similarly, tissue swelling and mucus production can be observed during cleaning and
                                  protective activities (e.g., Bak and Elgershuizen 1976; Dallmeyer et al. 1982). Specifically,
                                  Bak and Elgershuizen (1976) could find no specific reaction of corals to oil-sand particles.
                                  The rejection mechanisms utilized in off-sand removal were the same, and apparently
                                  functioned in the same manner, as those used in the rejection of clean sediments.
                                      It is unlikely that chemical dispersants would be used far from shore in the open ocean
                                  in the vicinity of the banks of the Gulf of Mexico.
                                      In a series of field experiments utilizing oil containment barriers, LeGore et al. (1989)
                                  exposed portions of an Arabian Gulf coral reef to oil, dispersant, and chemically dispersed oil.
                                  Water depth over the experimental site varied from one to three meters, depending on tidal
                                  phase. Acropora spp. accounted for more than 95% of the corals included in each test plot.
                                  Exposures were conducted for 24 and 120 hours. Corals were examined for biological impacts
                                  immediately after the exposure, and then at three-month intervals for a year. For the most
                                  part, coral growth appeared unaffected by the exposures; however, some Acropora specimens
                                  exposed to the chemically dispersed oil for 120 hours exhibited delayed, but minor, effects,
                                  which became apparent only during the relatively cold stressful winter season.










                  IV-182

                      Structure removal results in water turbidity, sediment deposition, and potential explosive shock wave
                  impacts. If carried out using current explosive methods, removal of platforms constructed on or very near
                  sensitive habitats would adversely affect benthic habitats very near the removal site. Both explosive and
                  nonexplosive removal operations would disturb the seafloor and resuspend sediments in the water column,
                  resulting in turbidity. Explosive methodologies create more turbidity than nonexplosive methods. Deposition
                  of resuspended sediments would occur much in the same manner as discussed for muds and cuttings discharge,
                  smothering and perhaps causing mortality of sessile benthic invertebrates. Turbidity can reduce light levels and
                  clog of filter-feeding mechanisms. These conditions could lead to reduced productivity, susceptibility to
                  infection, and mortality. Explosive structure removals create shock waves, which could also harm resident
                  biota. However, it appears that corals and other sessile invertebrates are fairly resistant to shock. O'Keeffe
                  and Young (1984) have described the impacts of underwater explosions on various forms of sea life. Most of
                  their data, however, were derived from open-water explosions of a much larger size than those used in typical
                  structure removal operations. They found that sessile organisms of the benthos, such as barnacles and oysters,
                  and many motile forms of life (such as shrimp and crabs) that do not possess swim bladders are remarkably
                  resistant to the blast effects from underwater explosions. Many of these organisms not actually in the
                  immediate blast area would survive. Data from underwater explosive tests indicate that oysters exposed to the
                  detonation of 135-kg (300-1b) charges in open water showed only 5 percent mortalities at distances of 8 rn (25
                  ft). Crabs exposed to 14-kg (30-1b) charges of explosives in open water showed 90 percent rnortalities at 8 m
                  (25 ft), but very few died at 46 m (150 ft). These authors also noted ". . . no damage to other invertebrates
                  such as sea anemones, polychaete worms, isopods, and amphipods." Benthic organisms appear to be further
                  protected from the impacts of subbottorn explosive detonations by the very rapid attenuations of the
                  underwater shock wave through the seabed enroute to the benthic communities. Theoretical predictions
                  suggest that the shock waves of explosives set 5 rn below the seabed as required by MMS regulations would
                  further attenuate blast effects. Charges used in OCS structure removals are typically much smaller than some
                  of those cited by O'Keeffe and Young. (It should be further noted that the Programmatic Environmental
                  Assessment for Structural Removal Activities [USDOI, MMS, 1987c] predicts low impaws to the sensitive
                  offshore habitats from platform removal precisely because of the effectiveness of the proposed stipulation in
                  preventing platform emplacement in the most sensitive areas of the topographic features of the Gulf of
                  Mexico.) In any event, the relatively small size of the charge (normally 50 lb or less) and the fact that the
                  charge is detonated 5 m below the mudline would serve to restrict the impacts to very close to the structure
                  being removed. The stipulation discussed above would preclude platform installation in the No Activity Zone,
                  thus preventing adverse effects from nearby removals. It is unlikely that more distant removals would impact
                  the biota of the banks.


                  Base Case Ana4uis

                     Fifteen of the 16 topographic features of the Central Gulf are located in Subarea C-2; 1 is in C-3 (in both
                  cases they occupy a very small portion of the entire area). Thus, these communities will not be exposed to the
                  full level of the projected impact-producing factors of Table IV-2; the amounts of wastes discharged in the
                  vicinity of a bank will be some very small fraction of those shown in Table IV-2.
                     As noted above, the proposed Topographic Features Stipulation would serve to eliminate most of the
                  potential impacts to the biota of the banks from oil and gas operations. The impact-producing factors that
                  could still affect the banks from operations outside the No Activity Zones are drilling effluent discharges,
                  blowouts, and oil spills.
                     With the inclusion of the proposed Topographic Features Stipulation, no discharges of drilling effluents,
                  including produced water, would take place within the No Activity Zones; discharges in areas of 1,000 m, 1,
                  3, or 4 miles, depending on the bank, around the No Activity Zone would be shunted to within 10 m of the
                  bottom. This procedure would essentially eliminate the threat of drilling effluents reaching; the biota of the
                  bank; however, there may be some small risk of such effluents and produced waters reaching the bank. For
                  purposes of this analysis, it is assumed that such impacts would occur 5-10 times during the life: of this proposal;
                  the severity of such impacts is judged to be such that there may be a loss of a few elements at the regional or










                                                                                                                               IV-183

                 local scale, but no interference to the general system performance. Recovery of the system to pre-interference
                 conditions is rapid.
                     Blowouts seldom occur (see Section IV.A.2.d.(8) and below), and with the application of the proposed
                 stipulation, none can occur within the No Activity Zones. Blowouts outside the No Activity Zones are unlikely
                 to have an impact on the biota of the banks. Since only one blowout is assumed to occur in each of Subareas
                 C-2 and C-3, where the banks are found, for purposes of this analysis, a blowout in the vicinity of a topographic
                 feature is not expected to occur during the life of this proposal. If one were to occur, it may cause the loss of
                 a few'elements at the local scale, but no interference to the general system performance would occur, and
                 recovery of the system to pre-interference conditions would be rapid.
                     There is an estimated 16 percent chance of one or more oil spills greater than or equal to 1,000 bbl
                 occurring in the Central Gulf as a result of the proposed action (Base Case) (Table IV-19), and it is assumed
                 that 21 spills of greater than 1 and less than or equal to 50 bbl will occur each year. It is further assumed that
                 there will be one spill of greater than 50 and less than or equal to 1,000 bbl, and one spill of 6,500 bbl is
                 assumed to occur during the 35-year life of the proposed action (Table IV-2 and Section IV.C.1.). In addition,
                 it is assumed there will be four spills of diesel oil and other pollutants, the average size of which will be 34 bbl.
                 (Section IV.C.1.). In the Central Gulf, Sonnier Bank crests the shallowest at 18 m. Therefore, a surface oil
                 spill would likely have no impact on the biota of Sonnier Bank or the other topographic features because any
                 oil that might be driven to 18 m or deeper would be well below the concentrations needed to cause an impact.
                 However, spills resulting from this proposal are assumed to be subsurface. Such spills are expected to rise to
                 the surface, and any oil remaining at depth will be swept clear of the banks by currents moving around the
                 banks (Rezak et al., 1983). As noted above, there have been only 28 oil spills resulting from blowouts on the
                 OCS between 1956 and 1989; only 4 blowouts are assumed for the entire CPA over the 35-year of the
                 proposed action. In the years 1967-1986, there have been only 31 oil spills from pipelines on the OCS, 23 of
                 which were between 50 and 1,000 bbl and only 8 more than 1,000 bbl (USDOI, MMS, 1988b). Thus, a blowout
                 is considered very unlikely to occur near a bank. If a seafloor oil spill were to occur, the spill would have to
                 come into contact with a biologically sensitive feature. The fact that the topographic features are widely
                 dispersed in the Central Gulf, combined with the probable random nature of spill locations, would serve to limit
                 the extent of damage from any given spill to only one of the sensitive areas. The currents that move around
                 the banks will steer any spilled oil around the banks rather than directly upon them, lessening impact severity.
                 Furthermore, the No Activity Zones established by the proposed Topographic Features Stipulation would serve
                 to keep such occurrences from very near the banks.

                 Summary

                     Several impact-producing factors may threaten the communities of the topographic features.
                     Because of the proposed Topographic Features Stipulation, operational discharges (drilling muds and
                 cuttings, produced waters) would have little impact on the biota of the banks. Recovery from any impact would
                 be rapid.
                     Blowouts may similarly cause damage to benthic biota, but due to the application of the proposed
                 Topographic Features Stipulation, they would have little impact on the biota of the banks. Recovery from any
                 impact would be rapid.
                     Oil spills (there is an estimated 16% chance of an off spill more than or equal to 1,000 bbI occurring in
                 the Central Gulf as a result of this proposed action) will cause damage to benthic organisms if the oil contacts
                 the organisms; such contact is not expected and, because of the proposed Topographic Features Stipulation,
                 spills would not occur very near to the biota of the banks.

                 Conclusion


                     The proposed action is expected to cause little to no damage to the physical integrity, species diversity, or
                 biological productivity of the habitats of the topographic features of the Gulf of Mexico. Small areas of 5-10
                 M2  would be impacted, and recovery from this damage to pre-impact condition is expected to take less than
                 2 years, probably on the order of 2-4 weeks.










                  IV-184

                  Effects of the Base Case Without the Proposed Stipulation

                      Several impact-producing factors may threaten the communities of the topographic features.
                      Vessel anchoring and structure emplacement result in physical disturbance of the benthic environment and
                  are the most likely activities to cause permanent or -long-lasting impacts to sensitive offshore habitats, destroying
                  large amounts of (10's to 100's of in) of corals and other reefal organisms. Recovery frorti damage caused
                  by such activities may take 10 or more years. Impacts from this factor are considered to be serious and
                  potentially irreversible.
                      Operational discharges (drilling muds and cuttings, produced waters) may impact the b iota of the banks
                  due to turbidity and sedimentation, resulting in death to benthic organisms in large areas. Recovery from such
                  damage may take 10 or more years. Impacts from this factor are also considered to be serious and potentially
                  irreversible.
                      Blowouts may similarly cause damage to benthic biota by resuspending sediments, cawing turbidity and
                  sedimentation, and resulting in death to benthic organisms. Recovery from such damage may take up to 10
                  years. As noted above, only two blowouts are assumed to occur in Subareas C-2 and C-3 where the banks are
                  found; thus, blowouts are not expected to impact the biota of the banks.
                      Oil spills will cause damage to benthic organisms if the oil contacts the organisms. As noted above, impacts
                  from this factor are not considered to be of concern.
                      Structure removal using explosives (as is generally the case) results in water turbidity, sediment deposition,
                  and potential explosive shock-wave impacts. Severe damage to benthic organisms could result. Recoveryfrom
                  such damage could take more than 10 years. Impacts from this factor are considered to be serious.
                      It follows from the above that activities resulting from this proposal, especially bottom-disturbing activities,
                  have a potential for causing serious and potentially irreversible, impacts to the biota of' the topographic
                  features.


                  High Case Analysis

                      Higher off and gas activity may be expected near the topographic features of the Central Gulf as a result
                  of the High Case scenario. The biota of the topographic features would be subject to the same impact-
                  producing factors as in the Base Case--discharges associated with drilling, blowouts, and oil spills. As in the
                  Base Case, the topographic features are found only in Subareas C-2 and C-3. Thus, these communities will
                  not be exposed to the full level of the projected impact-producing factors of Table IV-2; the amounts of water
                  discharged in the vicinity of a bank will be some very small fraction of those shown in Table IV-2.
                      As noted above, the proposed Topographic Features Stipulation would serve to eliminate most of the
                  potential impacts to the biota of the banks from oil and gas operations.
                      Because of the proposed Topographic Features Stipulation, operational discharges (drilling muds and
                  cuttings, produced waters) would have little impact on the biota of the banks. Recovery from any impact would
                  be rapid.
                      Blowouts may similarly cause damage to benthic biota, but due to the application of the proposed
                  Topographic Features Stipulation, they would have little impact on the biota of the banks. Recovery from any
                  impact would be rapid.
                      There is an estimated 32 percent chance of one or more an oil spills greater than or equal to 1,000 bbl
                  occurring in the Central Gulf as a result of the High Case (Table IV-19). It is also assumed that 47 spills of
                  greater than I and less than or equal to 50 bbl and that 2 spills greater than 50 and less than 1,000 bbl will
                  occur during the 35-year life of the proposed action. In addition, it is assumed there will be 23 spills of diesel
                  oil and other pollutants, the average size of which will be only 34 bbl (Table IV-2). It is assumed that one oil
                  spill of 6,500 bbl will occur (Section IV.C.1.). As with the Base Case, the widely dispersed nature of the banks,
                  the depths of the banks, and the currents at the banks are expected to prevent oil from impacting the banks.
                  Therefore, it is expected that no spills of any size will contact the biota of the topographic features.










                                                                                                                            IV-185


                   Conclusion

                       The High Case scenario is expected to cause little to no damage to the physical integrity, species diversity,
                   or biological productivity of the habitats of the topographic features of the Gulf of Mexico. Small areas of 5-10
                   M2 would be impacted, and recovery from this damage to pre-impact conditions is expected to take less than
                   2 years, probably on the order of 24 weeks.

                   (3) Impacts on Water Quality
                       Sections providing supportive material for the water quality analysis include Sections III.A.6. (description
                   of water quality), IV.A.2. (OCS infrastructure, activities, and impacts), IV.B.6. (major sources of on
                   contamination in the Gulf of Mexico), and IV.C.2. (oil spills--characteristics, fates, and effects).

                   Coastal and Estuarine Waters

                       Riverine flows into the Gulf of Mexico determine estuarine and nearshore water quality, with the
                   Mississippi River being the most significant source of pollution to this region. Major point sources along the
                   Gulf Coast include the petrochemical industry, hazardous waste sites and disposal facilities, agricultural and
                   livestock farming, manufacturing industry activities, fossil fuel and nuclear power plant operations, pulp and
                   paper mill plants, commercial and recreational fishing, municipal wastewater treatment, and maritime shipping
                   activities. The coastal portion of the north-central Gulf of Mexico (primarily Louisiana) is characterized by
                   water quality problems resulting from the discharge or release of industrial and domestic wastes. A more
                   detailed discussion of the Gulfs coastal and estuarine water quality is presented in Section III.B.6.
                       Water quality in coastal and estuarine areas adjacent to the CPA may be altered by a number of OCS-
                   related activities resulting from proposed Sale 142. These include routine point and nonpointsource discharges
                   from onshore support facilities; discharges from associated support vessel traffic; canal maintenance dredging
                   and pipeline emplacement actions; produced waters discharges; onshore disposal of OCS-generated, off-field
                   wastes; and oil and chemical spills greater than 50 bbl from both onshore and offshore OCS support activities.
                       The construction and operation of onshore facilities supporting OCS activities in the Gulf may impact
                   coastal and nearshore water quality by routine point and nonpoint source pollution. Increased effluent
                   discharges from OCS support facilities may contribute to point source pollution within coastal areas. These
                   effluents are commonly discharged into surface waters after treatment The degree of environmental damage
                   will be related to the toxic nature of the discharge, the biota present, and the characteristics of the receiving
                   waters. Likewise, runoff from existing OCS facilities is extensive and can have significant impacts to the
                   surrounding area. Runoff from these facilities is likely to contain oil, brine, particulate matter, heavy metals,
                   petroleum products, process chemicals, and soluble inorganic and organic compounds leached from the soil
                   surface (NERBC, 1976). Aside from adding contaminants to coastal waters, runoff from such facilities may
                   alter circulation in wetland areas and may affect flushing rates and salinity gradients.
                       Water quality may be degraded from bilge and ballast water discharges, contaminants in antifouling ship
                   paints released to surrounding waters, discharges of treated sanitary and domestic wastes, discharge of solid
                   wastes, and chronic spills from support vessels. Spills greater than or equal to 1,000 bbl may also occur in
                   connection with the offloading and onloading of crude from shuttle tankering and barging activities and from
                   fueling activities associated with supply boat support.
                       Dredging operations for navigation channel construction and maintenance result in the release of sediments
                   into the water column, resulting in short-term, localized impacts. Navigation channels serve as routes for vessel
                   traffic traveling between OCS and onshore service and supply bases. These are also traversed by barges
                   carrying oil from the OCS or between terminals and may be used to transport pipelines and platforms to the
                   OCS. Likewise, pipeline landfalls and pipeline excavation and burial techniques cause increased disturbances
                   of bottom sediments and water column turbidities. Such increases have a nominal effect on the productivity
                   of phytoplankton and may inhibit the respiratory and feeding mechanisms of numerous benthic and pelagic










                 IV-186

                 marine organisms within the area of disturbance. These activities could result in the resuspension of settled
                 pollutants, heavy metals, and pesticides, if present.
                     Boesch and Raba" (1989a) estimated 434,772 bbl of OCS produced waters are discharged daily into
                 Louisiana coastal waters. These discharges originated from 16 separation facilities located in salt marsh
                 environments along Louisiana's coastline (of the 53 separation facilities located within Louisiana, 1.6 were
                 known to discharge substantial amounts of produced waters). These 16 facilities occupy 11 sites. Rabalais et
                 al. (1991) updated the statistics of the earlier 1989 study. These revised estimates indicate that 253,994 bbl/day,
                 or 25 percent, of all OCS produced waters are piped ashore for separation and treatment. Produced. waters
                 are commonly characterized as those waters and particulate matter brought to the surface during oil and gas
                 production. The amount and characteristics of these waters are highly dependent on the method of production,
                 field characteristics, and location. These waters may contain high levels of total dissolved solids, oxygen-
                 demanding wastes, toxic metals, oil and grease contaminants, and naturally occurring radionuclides. In. March
                 1991, the Louisiana State Legislature approved regulations banning the discharge, into State waters, of all oil
                 and gas activity-derived wastewaters (primarily produced waters). The State's effluent guideline standards have
                 been revised such that there shall be no discharge of produced waters into State waters after January 1, 1995,
                 unless authorized in an approved elimination schedule or are in effluent limitation compliance.
                    A large portion of the wastes generated from offshore oil and gas exploration and development activities
                 is discharged directly into surrounding offshore waters. In addition to the wastes discharged offshore, a number
                 of wastes are brought ashore for disposal. These include some drilling muds, liquid wastes, fracking fluids,
                 emulsifiers, workover fluids, biocides, mud additives, etc. Once ashore, many of these wastes are transported
                 via truck to adjacent parishes, counties, or even to other States for off-site storage and disposal. Disposal of
                 such wastes is accomplished through a wide variety of methods, including reinjection, contaftiment in surface
                 impoundments, land application, landfill, and burial. Improper storage or disposal of drums, containing
                 solvents, corrosion inhibitors, and biocides used in drilling operations, also presents a potential for
                 environmental problems. Likewise, the improper design and management of storage tanks and multi-purpose
                 waste pits at commercial oil-field disposal facilities pose to adversely impact surrounding surface and ground
                 waters and wetland areas. Discarded oil-field equipment may also pose an environmental threat to areas
                 surrounding storage sites, cleaning sites, scrap yards, and metal reclamation yards. Surfaces of production
                 tubing, holding tanks, separators, heater treaters, and other like equipment may be contaminated with scale
                 material containing naturally occurring radioactive material (NORM).
                    Bohlinger (1990) indicated that workers employed at oil field pipe and cleaning facilities may be exposed
                 to potential health risks associated with inhalation and/or ingestion of dust particles containing elevated levels
                 of alpha-emitting radionuclides. Furthermore, the potential exists for radium-226 to enter both aquatic and
                 terrestrial food chains due to lax disposal requirements. Bohlinger further indicated that the health risks and
                 environmental consequences associated with the disposal of NORM-contaminated oil-field wastes are largely
                 unknown at this time. According to Louisiana's Department of Environmental Quality, NORM-contaminated
                 wastes are placed in Department of Transportation approved 55-gallon waste disposal drums. As indicated
                 above, improper storage of these drums and contaminated equipment presents the potential for causing adverse
                 impacts to waters surrounding these sites, primarily from surface runoff. (See Sections IV.A.2.d.(5) and
                 IV.A.3.c.(4) for more detailed discussions of NORM and solid-waste disposal practices.)
                    Oil spills constitute one of the most visible forms of pollution. Once spilled, the oil's chemistry is altered
                 by a number of processes that modify its characteristics in water (Section W.C.2.). Significant deterioration
                 of nearshore water quality would occur proximate to a continuous source of oil and would continue until the
                 source were removed. The impact to water quality from spills greater than or equal to 1,000 bbl is expected
                 to result in a disturbance of sufficient severity to alter water during the year of impact In the case of spills
                 less than 1,000 bbl but greater than 50 bbl, there would be some change in water parameters before cleanup,
                 but no effect to water users would occur afterwards. If a slick from an OCS oil spill greater than or equal to
                 1,000 bbl were to reach or occur in protected bays or wetland areas, the dissipating factors reducing its
                 concentration in water would be slower due to the low energy of such areas and the thickness of the oil on
                 isolated water bodies. Most of the oil would weather, and quantities of hydrocarbons in much of the originally
                 oiled area would likely return to background levels within several months after the spill occurred. Some of the
                 oil, however, could be pushed into clumps of marsh vegetation or into protected pools or embayments, resulting










                                                                                                                            IV-187

                in thick layers of off on these water bodies or marsh surfaces. These isolated pools of oil would weather more
                slowly, and oil coating the sediments and vegetation might be released into the surrounding water bodies for
                a much longer time period.

                    Base Case Ana4uis

                    Under the Base Case analysis, it is expected that the existing onshore infrastructure base in the Central
                Gulf is sufficient to support proposed Sale 142 activities and that no new infrastructure will be constructed.
                Despite this, point and nonpoint source discharges (Section IV.A.3.c.) occurring from existing onshore support
                facilities may impact coastal and nearshore water quality. Most of the OCS support infrastructure located in
                the CPA exists in coastal Louisiana, and it is here that surface-water contamination from these facilities will
                occur. Waters near support facilities may be expected to be contaminated with offy substances and off-field
                wastes from point source effluent discharges and small chronic spills. For the purpose of this analysis, chronic
                spills and chronic point source contamination are examined together with nonpoint source runoff. Section
                IV.C.l. provides assumptions for spills from OCS facilities. It is assumed that fewer than 10 spills (greater than
                1 but less than or equal to 50 bbl) are assumed to result from OCS sale-related activities in the coastal zone,
                primarily within Louisiana. It is further assumed that 21 spills of this size class are assumed to result from
                proposed offshore sale-related activities in the CPA (Table IV-2), but few of these spills will contact the
                coastline. Petroleum hydrocarbons introduced into marine and coastal waters would have varied effects
                depending on the resource impacted, stage of weathering, and local physical and meteorological parameters.
                Some crude oil components are highly toxic and may cause damage to marine organisms. This toxicity is
                directly proportional to the crude's aromatic content (Geraci and St. Aubin, 1988). Lower molecular weight
                hydrocarbon compounds (benzene, toluene, etc.) are considered acutely toxic, but are rapidly lost through
                evaporation and dissolution during the first days of a spill (Wheeler, 1978). Normal weathering processes
                encountered by oil spilled in open waters tend to detoxify its components, changing the oil's composition. The
                oxidized derivatives of petroleum hydrocarbons generated during weathering have been shown to be more
                water soluble than the parent hydrocarbons (Malins et al., 1982a). Boehm and Fiest (1982) indicated that the
                average reported concentrations of oil generally were less than 1 pg/l for pristine areas, 2-100,ug/l for spills in
                nearshore areas, and 100-8W ILgIl in heavily polluted urban areas. Background levels in the Gulf of Mexico
                were reported at 0-70 ILgIl. In shallow areas, oil may become entrained in suspended particles and bottom
                sediments, subsequently being reintroduced into the water column. From these estimates, it is estimated that
                the effect of chronic contamination of CPA coastal waters due to the proposed sale would be negligible, with
                water characteristics rapidly returning to background levels. These discharges will, however, remain continuous
                over the 35-year life of the proposed action.
                    Table IV-6 provides the number of shuttle tanker trips to each major port, the number of barge trips to
                terminals by waterway, and the number of service vessel trips to service bases by waterway, respectively. Up
                to 17,600 service vessel trips, 77 barge trips, and 2 shuttle tanker trips are estimated to result from proposed
                sale-related activities. The Calcasieu (C-1) and Atchafalaya (C-2) Rivers, Freshwater Bayou (C-1), Vermilion
                (C-1) and Terrebonne Bays (C-2), and Mississippi River passes (C-3) of Louisiana are expected to receive the
                bulk of sale-related support vessel trips in the CPA. Besides barge trips to and from platforms, some barge
                traffic carrying oil from terminals to other terminals or refineries is expected to occur along the Gulf
                Intracoastal Waterway and adjoining navigation channels.
                    Antifouling paints used on boats and tankers have been shown to have toxic effects on some marine biota.
                Increased loadings within coastal waters of tributylin and copper compounds contained in antifouling paints
                are well documented (Geochemical and Environmental Research Group, 1988; Delfino et al., 1984).
                Tributyltin has recently been regulated to decrease the total amounts released into the environment from
                marine paints. Without knowing what effects the new regulations will have, but knowing that effects have been
                documented and that such discharges will take place on a routine basis for some of the life of the proposed
                action, impacts from antifouling paints associated with sale-related marine traffic are assumed to be low.
                Ballast and bilge waters from shuttle tankers are assumed to be discharged at onshore reception facilities and
                are not expected to impact coastal water quality. While inshore, service vessels are estimated to discharge
                approximately 3,000 liters of bilge water per trip in support of sale-related activities. An estimated 56 million










                 IV-188

                 liters (4,380 liters/day) will be discharged into coastal waters from vessels supporting the proposed sale
                 activities. The amount of bilge water discharged from service boats could result in coastal water quality impacts
                 when discharged into confined waters. Bilge waters may contain toxic petroleum products and :metallic
                 compounds leaked from machinery. Given the small concentrations expected, the continuous nature of the
                 discharges over the life of the proposal, the widespread nature of the receiving waters, and the assimilative
                 capacity of water bodies, it is expected that there will be some localized, short-term (up tD several weeks)
                 changes in water quality characteristics from background levels, depending on the length of the affected
                 channel, flushing rates, etc.
                     No new navigation channels are expected to be dredged; however, maintenance dredging of major
                 navigation channels and deepening of some channels to support service vessel traffic are eiq)ected to result
                 Dredging activities are expected to result in localized impacts (primarily elevated water column turlbidities)
                 occurring over the duration of the activities (up to several months). Such activities would preclude some
                 recreational and commercial uses within the immediate area. The periods for expected dredging operations
                 will generally allow for the recovery of affected areas between such activities. Impacts from dredgmig are
                 expected to be somewhat higher near the mouths of major rivers, where sediment inputs are. greater..
                     No new pipelines or canals are projected to be constructed; 98 percent of the oil and. most of the gas
                 produced will be transported ashore via the existing pipeline network (Table IV-2). Pipelines reduce the need
                 for barge and truck transport of petroleum and the potential for transfer spills. The environmental effects
                 associated with chronic pipeline leakage and malfunction are generally considered small (USDOC, NOAA,
                 1985). Given this and the small percentage of use of the existing pipeline network in support of the proposed
                 action, impacts from leakage and hydrologic alterations associated with pipelines are considered negligible.
                     In association with the proposed action, the amount of OCS produced water estimated to be transported
                 ashore in the CPA for separation, treatment, and disposal is approximately 34 MMbbl. Annually this equates
                 to 0.97 MMbbI or approximately 2,660 bbl per day. As indicated previously, the new Louisiana regulations
                 banning produced water discharges require such discharges to cease after January 1, 1995, unless they are on
                 an approved elimination schedule or are in effluent limitation compliance. The assumption, based on the new
                 regulations and discussionswith OCS produced-water separation facility operators, is that these sites will either
                 discontinue their operations, employ reinjection methods, modify existing operations and pipe the treated
                 waters back offshore, or discharge the treated waters into the Mississippi River (at select sites). Therefore,
                 the disposal of sale-related produced waters onshore is not expected to impact coastal and nearshore waters.
                     It is assumed the 18 percent of the drilling muds (744,000 bbl) associated with sale-related drilling activities
                 and 69,000 bbI of produced sand will be brought ashore for disposal (Table IV-4). The improper storage and
                 disposal of such oil-field wastes and contaminated oil-field equipment could result in adverse impacts to
                 surface- and ground-waters in proximity to disposal facilities, cleaning sites, and scrap yards. Many of these
                 wastes may be contaminated by NORM (Section IV.A.2.d.(5)). Improper design and maintenance of such
                 facilities could result in adverse impacts to these waters (Section IV.A.3.c.(4)). The quantities of many wastes
                 attributable to OCS activities, and more specifically the proposed action, are largely unknown, as are the
                 associated environmental consequences and health risks. However, study efforts are underway by Federal and
                 State governmental agencies and the off and gas industry to gather information on NORM, including its fate
                 and effects and its disposal and treatment alternatives.
                     The OSRA model (Table IV-21) indicates a very low chance (2%) of an off spill greater than or equal to
                 1,000 bbl occurring from OCS operations and contacting land along the CPA coastline within 10 days. One
                 oil spill of this size class is assumed to occur from the proposed action, but it will not contact nearshore open
                 waters (Section W.C.I.). It is further assumed that one oil spill greater than 50 and less than 1,000 bbl could
                 occur from sale-related activities in the CPA, however, this spill will not contact the coastline. It should be
                 noted that there could be some effects from residual weathered oil reaching coastal waters following a major
                 spill event. Impacts from low-level contamination were discussed earlier. Less than 10 oil spills greater than
                 I and less than or equal to 50 bbl are assumed to occur in coastal waters from OCS pipelines crossing coastal
                 and nearshore areas or from salc-related shuttle tankering or barging activities (Table IV-4). Petroleum
                 hydrocarbons introduced into marine and coastal waters may have varied effects depending on the resource
                 impacted, stage of weathering, and local physical and meteorological conditions. Some crude oil components
                 are highly toxic and may cause damage to marine organisms due to the crude's aromatic content. It is expected










                                                                                                                            IV-189

                 that normal weathering processes will degrade the oil by breaking down its toxic components. Background
                 levels in the Gulf of Mexico were reported at 0-70 Ag/L In shallow areas, off may become entrained in
                 suspended particles and bottom sediments and be subsequently reintroduced into the water column. Given
                 these estimates and the frequent nature of spills over the life of the proposal, the effect of hydrocarbon
                 contamination on the Gulfs coastal waters due to the proposed action is considered negligible, with water
                 characteristics rapidly returning to background levels within several days to weeks.

                    Summmy

                    All existing onshore infrastructure and associated coastal activities occurring in support of proposed Sale
                 142 will contribute to the degradation of regional coastal and nearshore water quality to a minor extent because
                 each activity provides a low measure of continuous contamination and because discharge locations are
                 widespread, particularly in the Mississippi Deltaic area of Louisiana. Process, cooling, boiler, and sewage water
                 effluents will be discharged through the use of the existing infrastructure and facilities. Because of the new
                 Louisiana regulations banning the discharge of produced waters into State waters, the onshore separation,
                 treatment, and disposal of approximately 34 MMbbl of OCS produced water are not expected to impact coastal
                 and nearshore water quality. Wastes and contaminated equipment from offshore will be brought ashore for
                 disposal and storage. Adverse impacts could occur to surface and groundwater in proximity to improperly
                 designed and maintained disposal sites and facilities. Maintenance dredging is expected to take place every
                 one or two years and will result in short-term, low-level impacts to the surrounding waters. The OCS-related
                 vessel traffic is likely to impact water quality through routine releases of bilge and ballast waters, chronic fuel
                 and tank spills, trash, and low-level releases of the contaminants in antifouling paints. The improper storage
                 and disposal of oil-field wastes and contaminated od-field equipment would adversely impact surface and
                 ground waters in proximity to disposal facilities, cleaning sites, and scrap yards. Surface and groundwater in
                 proximity to improperly designed and maintained disposal sites and facilities could be adversely impacted with
                 elevated concentrations of arsenic, chromium, zinc, cadmium, mercury, lead, barium, penta-chlorophenol,
                 naphthalene, benzene, toluene, and radium.
                     One oil spin greater than or equal to 1,000 bbl and 1 oil spill greater than 50 bbl and less than 1,000 bbl
                 are assumed to occur, but not assumed to contact coastal and nearshore waters. An additional 31 spills greater
                 than I but less than or equal to 50 bbl are assumed to result from OCS sale-related activities both in the
                 coastal zone and from offshore. Of these, fewer than 10 associated with onshore support and vessel activities
                 are assumed to occur in coastal waters. Sale-related spills will introduce oil into nearshore waters, creating
                 elevated hydrocarbon levels (up to 100+ lAg/1) within affected waters. Much of the oil will be dispersed
                 throughout the water column over several days to weeks. In shallow areas, oil may become entrained in
                 suspended particles and bottom sediments. Spins would affect water uses for up to several weeks, and then
                 only near the source of the slick. Therefore, the effect of chronic contamination of CPA coastal waters due
                 to the proposed sale is considered negligible, with water characteristics rapidly returning to background levels.

                 Marine Waters

                     The Gulf of Mexico is a semi-enclosed water body with oceanic inputs through the Yucatan Channel via
                 the Caribbean and with principal outflow through the Straits of Florida. As previously noted, the presence of
                 the Mississippi River, as well as a host of other major drainage systems, strongly influences the northern Gulf
                 of Mexico's marine water quality. Drainage from approximately two-thirds of the area of the United States
                 and more than one-half the area of Mexico empties into the Gulf. This large amount of runoff, with its
                 nonoceanic composition, mixes into the surface water of the northwestern Gulf and makes the chemistry of
                 parts of this system quite different from that of the open ocean. Degradation of the Gulfs marine waters is
                 associated with coastal runoff, riverine inputs, and effluent discharges from offshore enterprises consisting of
                 OCS activities and marine transportation.
                     Effluents from normal offshore oil and gas operations are complex and may be transformed chemically,
                 biologically, or through radioactive decay when introduced into the marine environment. These wastes may
                 be dissolved and form new substances or may be mixed vertically and horizontally in the water column by










                 IV-190

                 small-scale turbulence or large-scale currents, and they may precipitate to the bottom and. be absorbed by
                 bottom sediments or be recycled by these same processes. This series of transformations will govern a waste's
                 transport through the water column and its effect on marine organisms. The biological effects ma, be on
                 individual organism populations, or entire ecosystems, with both long-term and short-term consequences. The
                 method of disposal into the environment, as well as the chemical properties of each source, will influence a
                 waste's distribution throughout the Gulf.
                     The impact-producing factors leading to water quality degradation resulting from offshore OCS oil and gas
                 operations include the resuspension of bottom sediments through exploration and development activities,
                 pipeline construction, and platform-removal operations; the discharge of deck drainage, sanitary and domestic
                 wastes, produced waters, drilling muds and cuttings and workover fluids; and accidental hydrocarbondischarges
                 due to spills, blowouts, or pipeline leaks. These factors are more thoroughly discussed in Section IV.A.2.
                     Drilling, platform construction, and pipelaying activities increase water column turbidity by resuspending
                 bottom sediments. Such increases would only nominally impact the productivity of phytoplankton, but may
                 temporarily inhibit the respiratory and feeding mechanisms of numerous benthic and pelagic marine organisms
                 within the affected area.
                     Aside from creating increased water column turbidity, explosive platform removal may adversely impact
                 water quality by releasing explosive by-products into the water column upon detonation of charges to sever the
                 legs and pilings of a structure. These by-products may be gaseous, liquid, or solid, and may be soluble or
                 insoluble in water. In the case of a water surface burst (for scare charges), virtually all of the products become
                 airborne. Significant changes take place in surface effects when the explosion depth is increased, although the
                 gaseous products are ejected into the air by even relatively deep explosions. In this case, the gaseous products
                 form a spherical bubble that rises to the surface, resulting in the ejection of most of the gases.
                     The discharge of treated sanitary wastes from rigs and platforms will increase levels of suspended solids,
                 nutrients, chlorine, and biological oxygen demand (BOD) in a small area near the point of discharge. These
                 constituents are quickly diluted when discharged into the open Gulf. Treated deck drainage and domestic
                 wastes, most of which are taken ashore for proper disposal at an approved site, are minor discharges of no
                 consequence to offshore water quality.
                     The discharge of drilling muds and cuttings may degrade the quality of the waters immediately surrounding
                 discharge points. Continuous discharges (while drilling is in progress) may come from the solids control
                 equipment on each platform. Bulk discharges at high rates of discharge (80-110 ml/h) and Iasting for a period
                 of 20 minutes to 3 hours (Mors et al., 1982; Petrazzuolo, 1981), may take place once or twice during the drilling
                 of a well. The physical fates and biological effects of drilling discharges have been the subjects of considerable
                 study (e.g., NRC, 1983; IMCO et al., 1969; Neff, 1981; Petrazzuolo, 1981; Menzie, 1983; EcA:)mar, Inc., 1980;
                 Zingula, 1975; Symposium, 1980; Workshop, 1983). The consensus of this work is that such resuspension has
                 only a short-term local effect of a very limited nature. When discharged into the surrounding; offshore waters,
                 drilling muds may create turbidity plumes several hundred meters in length. If encountered in the very high
                 concentrations found at the discharge source, suspended solids associated with these discharges may cause
                 mortality in sensitive species and juveniles by clogging and damaging gill epithelia. Benthic infauna may be
                 affected by smothering and by the change of bottom sediment characteristics. Studies indicate that these
                 impacts are restricted to an area within 300-500 in of the discharge site. Dilution is extremely rapid in offshore
                 waters. A 1983 NRC study suggests that, for routine oil and gas discharges, the various components measured,
                 including turbidity, are at background levels by a distance of 1,000 in. The findings of several studies (NRC,
                 1983; Symposium, 1980; Neff, 1981; Petrazzuolo, 1981; Menzie, 1982; among others) suggest that the
                 environmental impacts of drilling discharges to OCS offshore-water quality are few, restricted. to a small area,
                 and temporary. Most water-based drilling fluids are slightly toxic or nontoxic. Toxicity is not of concern at the
                 concentrations found in the field at distances greater than 200-500 m from the discharge point. Much of the
                 toxicity of the aqueous fraction of drilling fluids appears to be attributable to volatile organic components,
                 including petroleum hydrocarbons and by-products of lignite and lignosulfonate.
                     Produced water constitutes the largest single source of materials discharged into the Gulf during normal
                 oil and gas operations. Most of the produced waters generated from the proposal will be discharged directly
                 to the surface waters surrounding the individual production installation; however, in some insi2nces, produced
                 waters will be piped ashore and treated for further disposal below ground (reinjection) or discharged in the










                                                                                                                              IV-191

                 Mississippi River (Section IV.A.3.c.(4)). The effects of produced waters on marine flora and fauna have been
                 examined in numerous case studies of existing production fields (Section IV.A.2.d.(5)). According to the
                 findings of investigators, the expected effects of these discharges on offshore water quality will be limited to
                 an area in proximity to the discharge source. Higher concentrations of trace metals, salinity, temperature,
                 organic compounds, radionuclides, and lower dissolved oxygen may be present near the discharge source.
                 Although the distance required to reach background levels will vary, according to the volume and characteristics
                 of each discharge, many investigators suggest that these levels are reached within a few to several hundred (200
                 m) meters of the source (Section IV.B.Lb.(4)(e)). All investigators agree that rapid dilution and turbulence
                 at the source limit the zone affected by these properties.
                      Contaminants from oil- and gas-related marine transportation activities may enter the Gulf as a result of
                 routine operational discharges or accidental spills. Activities in support of the proposed action, consisting of
                 supply boat and shuttle tanker traffic, would routinely discharge pollutants consisting of domestic waste
                 products, such as sewage, food waste, and trash or debris, in very small amounts.
                      Oil spills present a threat to the water quality of any area contacted by off. Petroleum hydrocarbons
                 introduced into marine waters as a result of such a spill may have varied effects on the local biota, with impacts
                 ranging from negligible to very high, depending on the resource impacted, weathering, and the local physical
                 and meteorological parameters. Normal weathering processes tend to render the spilled oil less toxic by
                 breaking down its toxic components. Wind and currents would rapidly disperse oil released on the surface.
                 Section IV.C.2 provides an in-depth discussion on the fates and effects of spilled oil.

                      Base Case Analysis

                      Table IV-2 indicates that, under the Base Case scenario, the addition of 340 exploration and delineation
                 wells, 250 development wells, 30 platform complexes, and up to 240 km of pipe gathering lines is estimated
                 for the CPA- As a result, an estimated 318 MMbbI of produced waters, 4.1 MMbbl of drilling muds, 0.98
                 MMbbl of drill cuttings, 69,000 bbl of produced sand, and 787,000 ml of treated sanitary and domestic wastes
                 may be expected to be generated from the proposed action.
                      Immediate effects would be brought about by increased drilling, construction, and pipelaying activities,
                 increasing water column turbidities in affected offshore waters. Pipeline construction activities may result in
                 the resuspension of some 320,000 M3 of sediment during the installation of 64 km of pipelines in water depths
                 of 61 m (200 ft) and less. Offshore Subarea C-1 will support the greatest portion of sale-related pipeline burial
                 activities (48 km) and associated sediment resuspension (240,000 M3) (Table IV-2). Pipeline construction
                 activities may result in the resuspension of settled pollutants, toxic heavy metals, and pesticides, if present. The
                 magnitude and extent of turbidity increases would depend on the hydrographic parameters of the area, nature
                 and duration of the activity, and bottom-material size and composition. Sediments are known to contain the
                 major fraction of trace metals, chlorinated hydrocarbons, and nutrients in aquatic environments. Considering
                 the very low levels of trace metals found in the present-day ocean, despite the continuous output from land
                 sources, sediments serve as a permanent sink for trace metals, etc. Chen et al. (1976) indicated that concerns
                 regarding the release of significant quantities of toxic materials into solution during dredging operations and
                 disposal are unfounded. Their studies indicate that while some trace metals may be released in the parts-per-
                 billion range, others show no release pattern. Most of the concentrations in the soluble phase are well below
                 the allowable concentration levels of the ocean water discharge standards. It was pointed out that trace metals
                 and chlorinated hydrocarbons associated with organics and suspended particles released may present an
                 unknown effect. For the purpose of this analysis, the frequency of activities resulting in resuspension of
                 sediment is judged to occur nearly continuously throughout much of the northwestern and north-central Gulf
                 of Mexico. However, the severity of impacts would result only in some water quality parameters (primarily
                 increased water column turbidities) changing from background levels, and then only to a distance of 1,000 m
                 from the activity.
                      Aside from creating increased water column turbidity, explosive platform removal may adversely impact
                 water quality by releasing explosive by-products into the water column upon detonation of charges to sever the
                 legs and pilings of a structure. Twenty platforms associated with the proposal are assumed to be removed by
                 explosive methods (Table IV-2). The by-products of these events may be gaseous, liquid, or solid, and may










                 IV-192

                 be soluble or insoluble in water. Virtually all of the products become airborne in the case of a water surface
                 burst (for scare charges), even from relatively deep explosions. In the latter, the gaseous products form a
                 spherical bubble that rises to the surface, resulting in the ejection of most of the gases. The magnitude and
                 extent of turbidity increases would depend upon several hydrographic parameters, the duration of the activity,
                 and bottom-material size and composition. The consensus of this work is that such resuspension has only a
                 short-term local effect of a very limited nature. Because most of the gases are ejected into the air during rig
                 removal (by explosive means), the very small amounts that remain in the water column should either be
                 dissolved or dispersed so rapidly that water quality in the area would not be seriously affected.
                     The discharge of 787,000 M3 of treated sanitary and domestic wastes from the various rigs, and platforms
                 will increase levels of suspended solids (14-550 mg/1), nutrients, chlorine, and BOD near the point of discharge.
                 The volume and concentration of such wastes will vary widely over time, occupancy, platfonrn characteristics,
                 and operational situation. Properly operating biological treatment systems at these facilities have effluents
                 containing less than 150 mg/I of suspended solids. These are considered minor discharges and are quickly
                 diluted. The impact to offshore water quality from sale-related, treated sanitary and domestic waste discharges
                 will be negligible, occurring within a few meters of the discharge source.
                     Up to 317 MMbbI of produced waters are estimated to result from the proposed action. Of this, 284
                 MMbbl will be disposed of offshore (Table IV-2). Average annual estimates equate to 16 MMbbl, or
                 approximately 43,000 bbI per day. Offshore Subareas C-3 and C-4 will receive the greatest number of these
                 discharges with approximately 109 MMbbI and 123 MMbbl, respectively (Table IV-2). Analysis of the findings
                 of numerous investigators (e.g., Mackin, 1973; Gallaway, 1980; Bender et al., 1979; Reid, 1980), indicates that
                 the estimated effects of these discharges on offshore water quality will be limited to an area in proximity to the
                 discharge source. Higher concentrations of trace metals, salinity, temperature, organic compounds, and
                 radionuclides, and lower dissolved oxygen may be present near the discharge source. Although the distance
                 required to reach background levels will vary according to the volume and characteristics of each discharge,
                 investigators suggest that these levels are reached within a few hundred meters of the source (Section
                 IV.B.Lb.(4)(c)). They agree that rapid dilution and turbulence at the source limit the zone affected by these
                 properties. Because of the continuous nature of oil and gas activities within the northwesternand north-central
                 Gulf of Mexico, the frequency of produced-water discharges is judged to be somewhat continuously throughout
                 these areas. (Variable discharge volumes will be released continuously throughout the duration of any oil and
                 gas production operation.) The proposed produced-water discharges will be rapidly diluted within the
                 immediate vicinity of the discharge source. Significant increases in water concentrations of dissolved and
                 particulate hydrocarbons and trace metals are not expected outside the initial mixing zone or immediate vicinity
                 of the discharge source. Within the mixing zone of the discharge, long-term effects to water cDlumn processes,
                 consisting of localized increases in particulate metal and soluble lower molecular weight h, rocarbon (e.g.,
                                                                                                                 yd
                 benzene, toluene, and xylenes) concentrations, may be implicated. Trace metals and hydroairbons associated
                 with the discharge may be deposited within sediments near the discharge point. '
                     Some 4.1 MMbbI of drilling muds and 988,000 bbl of drill cuttings are estimated to result from drilling
                 activities associated with the proposed action (Table IV-2). Peak-year estimates are on the order of.563,000
                 bbl of drilling muds and 140,000 bbl of, drill cuttings (Table IV-2). Drilling muds and cuttings are routinely
                 discharged into offshore waters and are regulated by NPDES permits. As with produced-water discharges,
                 offshore Subareas C-3 and C4 would receive the greatest percentage are of these potential discharges. An
                 estimated 1.43 MMbbI of drilling muds and 344,000 bbl of cuttings could be generated in offshore Subarea C-3,
                 whereas in offshore Subarea C-4 an estimated 1.64 MMbbI of drilling muds and 393,000 bbl of cuttings could
                 be generated. It is assumed that 18 percent of these drilling muds (744,000 bbl) would be brought ashore for
                 disposal. Some 69,000 bbI of produced sands are estimated to be produced in the CPA from the proposed
                 activities. However, these will not be discharged into offshore waters, but rather brought ashore for disposal.
                 As with produced-water discharges, because of the continuous nature of oil and gas activities in the CPA, the
                 frequency of drilling mud and cutting discharges is judged to be nearly continuouslythroughout this area. From
                 the work of the investigators cited and previous monitoring studies, it can be concluded that the proposed
                 discharge of drilling fluids and cuttings would encounter rapid dispersion in marine waters. Discharge plumes
                 will be diluted to background levels within a period of several hours and/or within several hundred to 1,000 in
                 of the discharge source. The accumulation of toxic trace metals and hydrocarbons in exposed shelf waters,










                                                                                                                              IV-193

                  due to periodic releases of water-based generic muds and cuttings, is unlikely, and the long-term degradation
                  of the water column from such discharges is not a major concern. Few effects are expected to most water uses
                  from drilling muds and cutting discharges and then only in an area near the source.
                       Crude oils contain thousands of different compounds. Hydrocarbons account for up to 98 percent of the
                  total composition. Crude oils often contain wide concentrations of trace metals consisting of nickel, vanadium,
                  iron, sodium, calcium, copper, and uranium. Petroleum hydrocarbons introduced into marine waters may have
                  varied effects on the local biota with impact severity depending on the resource impacted, stage of weathering,
                  and local physical and meteorological conditions. Oil released on the surface will be rapidly dispersed by the
                  action of winds and currents, resulting in rapid transport, whereas for a subsurface spill, some of the off would
                  be distributed throughout the water column. It is assumed that one subsurface oil spill greater than or equal
                  to 1,000 bbl, one subsurface oil spill greater than 50 and less than 1,000 bbl, and approximately 21 spills greater
                  than or equal to 1 bbl and less than or equal to 50 bbI will occur from program-related activities offshore in
                  the CPA- In addition, 10 spills (diesel and oil-based drilling muds) are assumed to occur. The introduction
                  of oil into offshore waters will create elevated hydrocarbon levels (up to 100+ jig/1) within affected waters.
                  Much of the oil will be dispersed throughout the water column over several days to weeks. Little effect on
                  offshore water use is expected, and then only on an area near the source or slick.

                       Summary

                       Based on a review of projected sale-related support activities, the estimate is that offshore Subarea C-1
                  would receive the greatest portion of pipeline burial activities, whereas offshore Subareas C-3 and C-4 would
                  receive the largest amounts of operational discharges. Immediate effects would be brought about by increased
                  drilling, construction, and pipelaying activities, causing an increase in water column turbidities (lasting for
                  several hours with mud discharges, and several weeks with dredging-pipelaying activities) to the affected
                  offshore waters. The magnitude and extent of turbidity increases would depend on the hydrographic
                  parameters of the area, nature, and duration of the activity, and bottom-material particle size and composition.
                  Because of the continuous nature of oil and gas activities in the CPA, the frequency of drilling mud and cutting
                  and produced water discharges is judged to be nearly continuouslythroughout these areas. Proposed produced-
                  water discharges will be rapidly diluted within the immediate vicinity of the discharge source. Significant
                  increases in water concentrations of dissolved and particulate hydrocarbons and trace metals are not expected
                  outside the initial mixing zone or the immediate vicinity of the discharge source. Higher concentrations of trace
                  metals, salinity, temperature, organic compounds, and radionuclides, and lower dissolved oxygen may be present
                  near the discharge source (200 m). Within the mixing zone of the discharge, long-term effects to water column
                  processes, consisting of localized increases in particulate metal and soluble lower molecular weight hydrocarbon
                  (e.g., benzene, toluene, and xylenes) concentrations, may be implicated. Trace metals and hydrocarbons
                  associated with the discharge may be deposited within sediments near the discharge point. The proposed
                  discharge of drilling fluids and cuttings would encounter rapid dispersion in marine waters. Discharge plumes
                  will be diluted to background levels within a period of several hours and/or within several hundred to 1,000
                  meters of the discharge source. The accumulation of toxic trace metals and hydrocarbons in exposed shelf
                  waters, due to periodic releases of water-based generic muds and cuttings, is unlikely, and the long-term
                  degradation of the water column from such discharges is not a major concern. Few effects are anticipated to
                  most water uses from routine activities and discharges and then only in an area near the source.
                       Program-related spills will introduce oil into offshore waters and create elevated hydrocarbon levels (up
                  to 100+ Ag1l) within affected waters. Much of the oil win be dispersed throughout the water column over
                  several days to weeks. Little effect on water use is expected from these spills, and then only in an area near
                  the source and slick.


                  Conclusion


                       An identifiable change to the ambient concentration of one or more water quality parameters will be
                  evident up to several hundred to 1,000 m from the source and periods lasting up to several weeks in duration










                IV-194

                in marine and coastal waters. Chronic, low-level pollution related to the proposal will occur throughout the
                life of the proposed action.

                High Case Ana4wis

                     Coastal and Estuarine Waters


                     As indicated in the Base Case, it is expected in the High Case scenario that the existing onshore
                infrastructure base in the Gulf is sufficient to support the proposal. Despite this, point and :nonpoint source
                discharges (Section IV.A-3.c.) occurring from existing onshore support facilities may impact coastal and
                nearshore water quality. Most of the OCS support infrastructure located in the CPA exists in cDastal Louisiana
                and it is here that surface water contamination from these facilities will likely occur. Waters near support
                facilities may be expected to be contaminated with ofty substances and oil-field wastes from point source
                effluent discharges and small chronic spills. For the purpose of this analysis, chronic spills and chronic point
                source contamination are examined together with nonpoint source runoff. It is assumed that approximately
                57 spills greater than I and less than 50 bbl could result in the CPA from activities associated with the
                proposal. Fewer than 10 of these spills, primarily in Louisiana, are assumed in association with onshore sale-
                related support activities. It is estimated that 75 percent of these smaller chronic spills would range from 2
                to 10 bbl and occur in association with crude and product transfer operations in port areas. Lower molecular
                weight hydrocarbon compounds (benzene, toluene, etc.) are considered acutely toxic, but are rapidly lost
                through evaporation and dissolution during the first days of a spill (Wheeler, 1978). Normal weathering
                processes encountered by oil spilled in open waters tend to detoxify its toxic components. In shallow areas,
                oil may become entrained in suspended particles and bottom sediments and subsequently be reintroduced into
                the water column. Given these estimates and the frequent nature of spills over the life of the proposal, the
                effect of chronic contamination on the Gulfs coastal waters due to the proposed action is considered negligible,
                with water characteristics rapidly returning to background levels.
                     Over 30,850 service vessel trips, 178 barge trips, and 5 shuttle tanker trips are estimated to result from the
                proposed action in the CPA. According to historical data, the Calcasieu (C-1) and Atchafalaya Rivers (C-2),
                Freshwater Bayou (C-1), Vermilion Bay (C-1) and Terrebonne Bays (C-2), and the Mississippi River passes
                (C-3) of Louisiana are expected to receive the bulk of support vessel trips. Besides barge trips to and from
                platforms, some barge traffic carrying oil from terminals to other terminals or refineries is eiq)ected to occur
                along the Gulf Intracoastal Waterway and adjoining navigation channels.
                     Antifouling paints used on support vessels have been shown to have toxic effects on some marine biota.
                Increased loadings within coastal waters of tributyltin and copper compounds contained in antifouling paints
                will take place on a routine basis over the life of the proposal. Ballast and bilge waters from shuttle tankers
                are assumed to be discharged at onshore reception facilities and are not expected to impact coastal water
                quality. While inshore, service vessels are estimated to discharge an average of approximately 3,200 liters of
                bilge water per trip in support of sale-related activities. An estimated 98 million liters (approximately 7,600
                liters/day) will be discharged into coastal waters from vessels supporting the proposed sale activities (Table IV-
                4). Bilge water may contain toxic petroleum products and metallic compounds leaked frorn machinery and
                could degrade coastal water quality when discharged into confined waters. Given the small concentrations
                expected and the continuous and widespread nature of the discharges over the life of the proposal, it is
                expected that there will be some localized short-term changes (up to several weeks) in water quality
                characteristics from background levels, depending on the length of the affected channel, flushing rates, etc.
                     No new navigation channels are expected to be dredged as a result of the proposal. However, maintenance
                dredging of major navigation channels and deepening of some channels to support service vessel traffic are
                expected. Dredging activities are expected to result in localized impacts (primarily elevated water column
                turbidities) occurring over the duration of the activity (up to several months). Such activities would preclude
                some recreational and commercial water uses within the immediate area of this activity. 'The periods for
                expected dredging operations will generally allow for the recovery of affected areas between such activities.
                Impacts are expected to be somewhat higher in the Mississippi Delta area because of highersediment inputs.
                As with the Base Case, it is estimated that no new onshore pipelines will be constructed due to the proposed










                                                                                                                             IV-195

                action. Up to 98 percent of the off and most of the gas produced will be transported ashore via the existing
                onshore pipeline network (Table IV-2). Pipelines reduce the need for surface vessel transport of petroleum
                and the potential for transfer spills. The environmental effects associated with chronic pipeline leakage and
                malfunction are generally considered small (USDOC, NOAA 1985). Given this and the small percent of usage
                of the existing pipeline network in support of the proposed activities, impacts from leakage and hydrologic
                alterations associated with pipelines are considered negligible.
                     As a result of the High Case, the amount of OCS produced water estimated to be transported ashore for
                separation, treatment, and disposal is approximately 70.8 MMbbI over the life of the proposal. On the basis
                of the new regulations and discussions with OCS produced water site operators, MMS expects that many of
                these sites will either discontinue their operations, employ reinjection methods, modify existing operations and
                pipe the treated waters back offshore, or discharge the treated waters into the Mississippi River (at select sites).
                Therefore, the onshore disposal of sale-related produced waters is not expected to impact coastal and
                nearshore water quality.
                     As discussed under the Base Case, in addition to those wastes discharged offshore, a number of wastes are
                brought ashore for disposal. Approximately 1.3 MMbbI of drilling muds and 154,000 bbl of produced sand
                from sale-related exploration and production activities would be brought ashore for disposal (Table IV4). In
                addition, discarded ofifield equipment may also pose a potential environmental threat to areas surrounding
                storage sites, cleaning sites, scrap yards, and metal reclamation yards. Surfaces of production tubing, holding
                tanks, separators, heater treaters, and other like equipment may be contaminated with scale material containing
                NORM. The improper storage and disposal of ofl-field wastes and contaminated oil-field equipment would
                adversely impact surface and ground waters in proximity to disposal facilities, cleaning sites, and scrap yards.
                Improper design and maintenance of such storage facilities would result in adverse impacts from elevated levels
                of radium-226 contaminating surrounding water bodies and downstream users (human and livestock
                consumption, agriculture, etc. (Sections IV.A-2.d.(5) and IV.A.3.c.(4) contain more detailed discussions of
                NORM and solid-waste disposal practices).
                     Under the High Case scenario, it is assumed that 1 subsurface oil spill greater than or equal to 1,000 bbl
                would occur from sale-related activities in the CPA. In addition, 2 oil spills greater than 50 and less than 1,000
                bbl and 47 spills greater than 1 bbl and  *less than or equal to 50 bbl could occur from OCS pipeline, platform,
                and transportation sources offshore in the CPA. It is assumed that as much as 70 percent of the original
                volume of oil from the spill source will be lost within 110 days as a result of weathering processes and offshore
                cleanup. It should be noted that there could be some effects from residual weathered oil that could reach
                coastal waters following a spill greater than or equal to 1,000 bbl event. Impacts from low-level contamination
                were discussed earlier. As indicated, petroleum hydrocarbons introduced into marine and coastal waters may
                have varied effects depending on the resource impacted, stage of weathering, and local physical and
                meteorological conditions. Some crude oil components are highly toxic and may cause damage to marine
                organisms due to the crude's aromatic content. It is expected that normal weathering processes will degrade
                the oil by breaking down its toxic components. Background levels in the Gulf of Mexico were reported at 0-70
                iLgIl. In shallow areas, oil may become entrained in suspended particles and bottom sediments and
                subsequently be reintroduced into the water column. Given these estimates and the frequent nature of spills
                over the life of the proposal, the effect of hydrocarbon contamination on the Gulf's coastal waters due to the
                proposed action is considered negligible, with water characteristics rapidly returning to background levels within
                several days to weeks.

                     Marine Waters


                     Table IV-2 indicates that, under the High Case scenario, the addition of 540 exploration and delineation
                wells, 520 development wells, 50 platform complexes, and 400 kin of pipe gathering lines are estimated for the
                CPA. As a result, approximately 661 MMbbI of produced waters, 7.4 MMbbI of drilling muds, 1.7 MMbbl of
                drill cuttings, and 1.4 MM M3 of treated sanitary and domestic wastes may be expected to be generated from
                the proposed action.
                     Immediate effects would be brought about by increased drilling, construction, and pipelaying activities,
                causing an increase in water column turbidities (lasting for hours with mud discharges, to several weeks with










                  IV-196

                  dredging-pipelaying activities) to the affected offshore waters. Installation of an estimated 400 krn of new
                  pipelines offshore will result from sale-related activities. Guffwide, pipeline construction aclivities may result
                  in the resuspension of up to 360,000 M3 of sediment during the life of the proposed program (Table IV-2).
                  All burial activities will occur in water depths of 200 ft and less. Offshore Subarea C-1 will support the greatest
                  portion of program-related pipeline burial activities (48 km) and associated sediment resuspension (@40,000
                  m3 ). Pipeline construction activities may result in the resuspension of settled pollutants, toxic heavy metals,
                  and pesticides, if present. The magnitude and extent of turbidity increases would depend on the hydrographic
                  parameters of the area, nature and duration of the activity, and bottom-material size and composition. For
                  the purpose of this analysis, the frequency of activities resulting in resuspension of sediment is judged to be
                  nearly continuously throughout much of the northwestern and north-central Gulf of Mexico. However, the
                  severity of impacts would result only in some measures of water quality (primarily increa-sed water column
                  turbidities) changing from background levels, and then only within a distance of 1,000 m ftom the activity.
                      Aside from creating increased water column turbidity, explosive platform removal may adverseky impact
                  water quality by releasing explosive by-products into the water column upon detonation of charges to sever the
                  legs and pilings of a structure. Twenty-four platforms associated with the proposal are assumed to be removed
                  by explosive methods (Table IV-2). The by-products of these events may be gaseous, liquid, or solid, and may
                  be soluble or insoluble in water. Virtually all of the products become airborne in the case of a water surface
                  burst (for scare charges), even from relatively deep explosions. The magnitude and extent of turbidity increases
                  would depend upon several hydrographic parameters, the duration of the activity, and bottom-material size and
                  composition. Because most of the gases are ejected into the air during rig removal (by explosive means), the
                  very small amounts that remain in the water column should either be dissolved or dispersed so rapidly that
                  water quality in the area would not be seriously affected.
                      The discharge of 1.4  MMM3    of treated sanitary and domestic wastes from the various rigs and platforms
                  will increase levels of suspended solids (14-550 mg/1), nutrients, chlorine, and BOD near the point of discharge.
                  The volume and concentration of such wastes will vary widely over time, occupancy, platform characteristics,
                  and operational situation. Property operating biological treatment systems at these facilities have effluents
                  containing less than 150 mg/l of suspended solids. These are considered minor discharges and are quickly
                  diluted. The impact to offshore water quality from program-related, treated sanitary and domestic waste
                  discharges will be negligible, occurring within a few meters of the discharge source.
                      Up to 661 MMbbl of produced waters are estimated to result from the High Case (Table IV-2). Of this,
                  592 MMbbl will be discharged offshore. Offshore Subareas C-3 and C-4 will receive the greatest number of
                  these discharges with 161 MMbbl and 269 MMbbl, respectively, over the life of the proposal. The findings of
                  numerous investigators (e.g., Mackin, 1973; Gallaway, 1980; Bender et al., 1979; Reid, 19W) lead MMS to
                  expect the effects of these discharges on offshore water quality to be limited to an area in. proximity to the
                  discharge source. Higher concentrations of trace metals, salinity, temperature, organic compounds, and
                  radionuclides, and lower dissolved oxygen may be present near the discharge source. Because of the continuous
                  nature of oil and gas activities in the northwestern and north-central Gulf of Mexico, the frequency of produced
                  water discharges is judged to be nearly continuously throughout these areas. The assumption, based on the
                  work of the investigators cited and historical data, is that the produced-water discharges resulting from this
                  proposal will be rapidly diluted within the immediate vicinity of the discharge source. Significant increases in
                  water concentrations of dissolved and particulate hydrocarbons and trace metals are not expected outside the
                  initial mixing zone or immediate vicinity of the discharge source. Within the mixing zone of the discharge, long-
                  term effects to water column processes, consisting of localized increases in particulate metal and soluble lower
                  molecular weight hydrocarbons (e.g., benzene, toluene, and xylenes) concentrations, may be implicated within
                  the mixing zone of the discharge. Trace metals and hydrocarbons associated with the discharge may be
                  deposited within sediments near the discharge point
                      Some 7.4 MMbbl of drilling muds and 1.7 MMbbl of drill cuttings are estimated to result from drilling
                  activities associated with the proposed action (Table IV-2). Drilling muds and cuttings are routinely discharged
                  into offshore waters and are regulated by NPDES permits. As with produced-water discharges, offshore
                  Subareas C-3 and C-4 would receive the greatest percentage of these potential discharges. Approximately 2.5
                  MMbbl of drilling muds and 600,000 bbl of cuttings could be generated in offshore Subarea C-3, whereas in
                  offshore Subarea C-4, approximately 3 MMbbl of drilling muds and 708,000 bbl of cuttings could be discharged.










                                                                                                                        IV-197

               It is assumed that 18 percent of the drilling muds (1.3 MMbbl) associated with sale-related activities would be
               brought ashore for disposal. Some 154,000 bbl of produced sands are estimated to be produced in the CPA
               from the proposed activities. However, these will not be discharged into offshore waters, but rather brought
               ashore for disposal. When discharged into the surrounding offshore waters, drilling muds may create turbidity
               plumes several hundred meters in length. A 1983 NRC study suggests that for routine off and gas discharges
               the various components measured, including turbidity, are at background levels by a distance of 1,000 in.
               Ecomar Inc. (1980) indicated that, due to settling and dilution, suspended solid levels and metal concentrations
               decrease significantly with distance from the source. As with produced-water discharges, because of the
               somewhat continuous nature of oil and gas activities in the northwestern and north-central Gulf of Mexico, the
               frequency of drilling mud and cutting discharges is judged to be nearly continuously throughout these areas.
               From the work of the investigators cited and previous monitoring studies, it can be concluded that the proposed
               discharge of drilling fluids and cuttings would encounter rapid dispersion in marine waters. Discharge plumes
               will be diluted to background levels within a period of several hours and/or within several hundred to 1,000
               meters of the discharge source. The accumulation of toxic trace metals and hydrocarbons in exposed shelf
               waters, due to periodic releases of water-based generic muds and cuttings, is unlikely, and the long-term
               degradation of the water column from such discharges is not a major concern. Few effects from drilling muds
               and cutting discharges are expected on most water uses, and then only in an area near the source.
                   Crude offs contain thousands of different compounds formed during initial formation. Hydrocarbons
               account for up to 98 percent of the total composition. Crude oils often contain wide concentrations of the
               trace metals nickel, vanadium, iron, sodium, calcium, copper, and uranium. Petroleum hydrocarbons introduced.
               into marine waters may have varied effects on the local biota with impact severity depending on the resource
               impacted, stage of weathering, and local physical and meteorological conditions. Oil released on the surface
               will be rapidly dispersed by the action of winds and currents, resulting in rapid transport, whereas for a
               subsurface spill, some of the oil would be distributed throughout the water column. One oil spill greater than
               or equal to 1,000 bbl, 2 oil spills greater than 50 and less than 1,000 bbl, and approximately 57 spills greater
               than or equal to 1 bbl and less than or equal to 50 bbl are assumed to occur from program-related activities
               in the CPA. In addition, 23 spills (diesel and oil-based drilling muds) are assumed to occur. The introduction
               of oil into offshore waters will create elevated hydrocarbon levels (up to 100+ lAg/1) within affected waters.
               Background levels in the Gulf have been reported at 0-70 Ag1l. Much of the oil will be dispersed throughout
               the water column over several days to weeks. Little effect to offshore water use is expected, and then only in
               an area near the source or slick.


               Conclusion

                   Under the High Case scenario, an identifiable change to the ambient concentration of one or more water
               quality parameters will be evident up to several hundred to 1,000 in from the source and periods lasting up
               to several weeks in duration in marine and coastal waters. Chronic, low-level pollution related to the proposal
               will occur throughout the life of the proposed action.

               (4) Imp"& on Air Quality

                   This discussion analyzes the potential degrading effects on air quality by the activities and developments
               induced by the proposed sale. The following activities will potentially degrade air quality: platform emissions;
               drilling activities during exploration, delineation, and development; service vessel operation; evaporation of
               volatile hydrocarbons from surface oil slicks; and fugitive emissions during hydrocarbon venting and offloading.
               Sections presenting supporting materials and discussions are Sections III.A-2. and III.A.3. (descriptions of Gulf
               of Mexico meteorology and the coastal counties' air quality status), IV.C.l. (oil-spill assumptions), and
               IV.A.2.d.(6) (air emissions).
                   The parameters of this analysis are the emission factors, surface winds, stability of the overlaying air
               column, and the height of the atmospheric mixed layer.










                  IV-198

                       Emissions of certain primary pollutants are known to be detrimental to health and welfare. Nitrog n oxide
                                                                                                                          ,e
                  and nitrogen dioxide comprise NO. emissions. Nitrogen oxide is important because it can be converted into
                  nitrogen dioxide, which can be poisonous. Nitrogen dioxide reacts with water to form tiftric acid, which is
                  harmful to vegetation and construction materials. Further, nitrogen dioxide is involved in photochemical
                  reactions that yield ozone, which has significant effects on the atmosphere and the global climate and causes
                  respiratory problems. Carbon monoxide (CO) is a very toxic gas that reacts with hemoglobin in the blood and
                  blocks the transfer of oxygen to the body. Carbon monoxide constitutes and increases cardiovascular diseases,
                  affects the central nervous system, and contributes to the global climate cycle. Sulfur oxides (SO.) can combine
                  with water and oxygen to form very corrosive and irritating acids. These sulphur compounds produce; aerosols
                  that act as nuclei for rain, which removes sulphur from the atmosphere. Further, a correlation has been found
                  between SO, and respiratory diseases such as bronchitis. Volatile organic compounds (VOC'), or hydrocarbons,
                  are poisonous to humans at very high concentrations only, cause eye irritation, and play important roles in
                  atmospheric photochemical cycles. Particulate matter has a trimodal distribution, and particles that are smaller
                  than 10 microns (PM10) are detrimental to visibility and may cause respiratory problems. The visibility
                  reductions are caused primarily by particle scattering and by light absorption to a lesser exient. Thi;3 analysis
                  considers mainly total particulate matter (TSP).
                       Ozone is a secondary pollutant and "is one of the most toxic regulated pollutants underambient air quality
                  standards" (Godish, 1991, p. 159). It is formed by photochemical reactions involving some of the primary
                  pollutants. Ozone is important to the global climate and causes damage to plants and agricultural crops. At
                  concentrations of 196-784 jLgm-3 and exposures of 1-2 hours, it also affects lung functions. These effects are
                  transient and include reduction of tidal volume, increased respiration rates, increased pulrnonary resistance,
                  and changed respiration mechanics (Godish, 1991). Ozone can interfere with or inhibit the immune system.
                       Emissions of primary pollutants will occur during exploration, development, and production activities.
                  Typical emissions for exploratory and development drilling activities presented in Section IV.,&-2.d.(6) show that
                  emissions of NO, are between 4 and 34 times greater than emissions for other pollutants during exploratory
                  drilling activities. These emission estimates are based on a drilling scenario of a 10,000-ft hole during
                  development and 13,500-ft hole during exploration activities using about 597,000 hphr energy from diesel
                  engines over a period of 45 days. Statistics of wells drilled between 1985 and 1990 show an average hole depth
                  of 10,318 ft and a drilling period of 33 days. These values are close to those employed in calculating typical
                  well emissions, above.
                       Platform emission factors for the Gulf of Mexico region (presented in Section lV.A_2,.d.(6)) show NO.,
                  VOC, and CO emissions about three orders of magnitude larger than emissions of SO,, and TSP. The NO,,,
                  VOC, and CO emissions seem to be about 10 times greater than emissions from exploratory wells. This
                  discrepancy, however, is a mathematical artifact because well rates are based on a 45-day period while platform
                  rates are on a yearly basis. Emission rates during exploration are higher than emission rates during production.
                  Emission factors for other activities such as helicopters, tankers, loading and transit operations were obtained
                  from Jacobs Engineering Group, Inc. (1989) and USEPA (1985).
                       Other sources of primary pollutants are accidents, such as oil spills and blowoutss, related to OCS
                  operations. Typical emissions from OCS accidents consist of hydrocarbons; only blowouts -with fires produce
                  other primary pollutants. Most of the emission rates presented in the table below are small; even the emissions
                  for the 10,000-bbl spill cannot be sustained for long periods. Observe that emission rates decreased
                  approximately 50 percent by the second hour.
                       Once pollutants are released into the atmosphere, transport and dispersion processes start acting.
                  Transport processes of pollutants are carried out by the net wind circulation. The mean wind circulation is
                  discussed in Section III.A.2. During summer the wind regime in the CPA is predominantly onshore at, mean
                  speeds of 3 to 5 ms-1. Winter wind circulation is predominantly offshore at mean speeds of 4 to 8 ms-1.
                     . Pollutant dispersion or mixing depends on emission height, atmospheric stability, and nriLxed layer height.
                  The emission height on platforms of the Gulf of Mexico is determined by storm wave heights, storm tides, and
                  a safety factor. For water depths between 10 and 200 in, calculated emission heights are between 31 and 35
                  m, well inside the mixed layer. For emissions inside the atmospheric boundary layer, the heat flux, which
                  includes effects from wind speed and atmospheric stability (via air-sea temperature differences), is a better
                  indicator of turbulence available for dispersion (Lyons and Scott, 1990). Heat flux calculations in the CPA










                                                                                                                             IV-199

                (USDOI, MMS, 1988c) indicate an upward flux year-round, being highest during winter and lowest in summer.
                The atmospheric stability along CPA coastal areas of the Gulf of Mexico, discussed in Section III.A.2., is either
                neutral or stable more than 75 percent of the time. Atmospheric stability is also important because it helps
                to distribute and diffuse the available energy or momentum of the atmosphere.
                     A mechanism in part responsible for this distribution is buoyancy. It is well known that air density is
                inversely proportional to temperature. When the sea surface is warmer than the overlying air, the sea heats
                the air in contact with it. The warmer air becomes lighter, starts to rise, and is replaced by cooler air from
                above. The rising air acquires a vertical velocity that, when multiplied by its density, becomes a flux of vertical
                momentum by buoyancy or density differences. Vertical momentum flux can also occur because of
                mechanically generated turbulence, which is totally unrelated to density differences.
                     The mixing height is very important because it determines the space available for spreading the pollutants.
                Although mixing height information throughout the Gulf of Mexico is scarce, measurements near Panama City
                (Hsu, 1979) show that the mixing height can vary between 400 and 1,300 m, with a mean of 900 m. The mixing
                height tends to be higher in the afternoon, more so over land than over water. Further, the mixing height tends
                to be lower in winter, and daily changes are smaller than in summer.

                Base Case Analysis

                     The scenario discussed in Section IV.A- (Table IV-2) for the 35-year life of the proposed action establishes
                that 340 exploration and delineation wells and 250 development wells would be drilled, and 30 platform
                complexes would be emplaced. The sale area has been subdivided into four offshore subareas: C-1, C-2, C-3,
                and C-4 (Figure IV-1). The subsequent analyses are directed towards the potential degrading effects on air
                quality from OCS-related activities in each subarea. Table IV-2 presents the numbers of exploration,
                delineation, and development wells; platforms installed; and service-vessel trips for the proposed action in each
                subarea. The information presented below shows total emissions from wells, platforms, vessels, and other
                activities in the CPA during the proposed action. Observe that NO. still is the most emitted pollutant, while
                SO. is the least emitted. More important is that this information shows that wells and vessels contribute mostly
                NO,,, while platforms contribute mostly NO.. CO, and VOC. These emissions were calculated using an
                integration of well and platform emissions over time. Vessel and other emissions were calculated using the
                information presented in Table IV-2.
                                                        Total OCS Emissions in the CPA
                                                (tons over the 35-year life of the proposed action)

                     Activib2ollutant                            NO,            CO             so            THC             TSP

                     Service Vessels                            9,095.5        1,065.5         143.7           462.8        641.7
                     LTO Helicopters                               39.9           32.2           6.1            1.7           1.5
                     Cruise Helicopters                           128.8         368.0           27.6           30.0           36.8
                     Blowouts without Fire                          0.0           0.0            0.0            0.2           0.0
                     Spills without Fire                            0.0           0.0            0.0           255.07         0.0
                     Barge Loading                                  0.0           0.0            0.0           34.7           0.0
                     Tanker Loading                                 0.0           0.0            0.0           34.7           0.0
                     Transit Loss                                   0.0           0.0            0.0           90.0           0.0
                     Tanker Exhaust                                 4.6           0.5            5.7            0.0           1.6
                     Tug Exhaust                                   139.2          13.9           1.8            6.3           8.4
                     Exploratory Wells                          3,287.8         877.2          384.2           95.2         329.8
                     Development Wells                          1,611.0         429.8          189.0           47.2          162.0
                     Platforms                                  50,592.5        6,590.3         88.5        19,175.0         123.9

                     Totals                                     64,899.3       9,377.4         846.6        20,232.8       1,305.7










                 IV-200

                     Total emissions for each subarea in the CPA during the proposed action are presented below. Observe
                 that Subarea C-2, would generate the smallest emissions of all pollutants, while Subarea C-3 would generate
                 the greatest amounts of emissions.

                                                        Total Emissions in CPA Subareas
                                                 (tons over 35-year life of the proposed action)

                               Pollutant              C-1               C-2              C-3               C-4


                                   NO.                12,979.9          10,816.6         21,633.1          19,469.8
                                    CO                 1,875.5           1,562.9          3,125.8          2,813.2
                                    so.                 169.3             141.1            282.2             254.0
                                  THC                  4,046.6           3,372.1          6,744.3          6,069.8
                                   TSP                  261.1             217.6            435.2             391.7


                     The total pollutant emissions per year are not uniform. During the early years of the proposed action,
                 emissions would be small but increase over time with production. After reaching a maximum, emissions would
                 decrease rapidly to zero as all platforms and wells are removed and service vessels trips and other associated
                 activities are no longer needed.
                     The peak emissions in tons per year for the primary pollutants during the proposed action are indicated
                 below. It is very important to note that well drilling activities and platform peak emissions are not necessarily
                 simultaneous. However, it is assumed for this analysis that service vessel and other emissions and the well and
                 platform peak emissions occur simultaneously. In this analysis the aggregate peak emissions, which are two
                 to five times the mean emissions, will be employed. Use of the peak emission will provide the most
                 conservative estimates of impact levels to onshore air quality.

                                                     Peak and Mean Emissions in the CPA
                                                                     (tons/year)

                      Pollutant        Wells         Platforms       Vessels         Others        Mean           Aggrep-ate

                         NO.          716.24         2,572.50        268.80            0.00        1,854.27       2,877.10
                         CO           191.09          335.10         42.29             0.00         267.93           386.89
                         SO,,         83.76             4.50           5.28            0.00           24.19           81.58
                         THC          20.79           975.00         14.31             15.78        582.02        1,006.09
                         TSP          71.88             6.30         19.71             0.00           37.31           85.61



                     The mean emissions were computed by dividing the total emissions by the 35-year life of the proposed
                 action. Peak emissions from wells and platforms are obtained from their temporal distribution. Observe that
                 platforms and wells have the greatest peak emissions, while vessels have smaller emissions. The column headed
                 by "Others" includes emissions from accidents, helicopters, tankering, and barging operations and represents
                 average emissions per year. The peak emissions are contrary to the emission rates, where wells have greater
                 rates than platforms.
                     To estimate the potential impact of offshore emissions on offshore and onshore air quality, a steady state
                 box model (Lyons and Scott, 1990) was employed. The model is an expression of mass conservation and
                 assumes that pollutants are vertically dispersed and sources uniformly distributed. For the purpose of these
                 air quality analyses, an assumption of uniform distribution of average size sources throughout the planning
                 areas at this early stage is a reasonable approach. Predominance of unstable atmospheric conditions over the
                 sea, as discussed in Section III.A-2., ensures that pollutants are dispersed homogeneously. The model was
                 applied to NO,, emissions because these are the largest emissions. Because VOC emissions are not inert, the
                 box model cannot be used to assess their impacts on air quality. Concentrations for other pollutants can be










                                                                                                                            IV-201

                estimated by multiplying the NO,, concentrations by the ratio of the pollutant emissions over the NO, emissions.
                These concentrations are [CO]=0.134[NO.1; [SO,,j=0.028[N0.j; and rrSPI=0.346[NO,,]. Notice that
                concentrations of primary pollutants other than NO. would be smaller by more than 65 percent Impacts from
                VOC and CO will be estimated by comparing the offshore and onshore emission rates.
                    The box model was applied to the following conditions: onshore and offshore winds with speeds ranging
                from 1 to 7 ms-1, a mean mixing height of 900 in, and a low mixing height of 300 in. During offshore wind
                conditions, impacts to the onshore air quality from offshore CPA emissions are very low because the follutants
                are transported offshore. Concentrations over water in the different subareas started at 0.05 /Igm- near the
                coastline and increased to 0.20 pgm  -3 over Subarea C4, for a wind speed of 1 ms-1 and a mixing height of 900
                in. The greater the wind speed, the lower the concentration, and the smaller the mixing height, the larger the
                concentration. But even during the lowest wind speed and mixing height conditions, concentrations reached
                only 0.61 pgm-3. Conditions of onshore winds indicate that concentrations reaching land from Subarea C-3
                varied between 0.22 and 0.03 Agm-3 for speeds from 1 to 7 ms-1 and a mixing height of 900 in; for a 300-m
                mixing height, concentrations varied from 0.65 to 0.09 jLgin  -3 under the same wind speeds. For Subarea C-1
                the concentrations varied from 0.14 to 0.01 jugm-3 with a 900-m mixing height across the entire wind speed
                range; concentrationsvaried from to 0.41 to 0.03 Agrn-3 with a 300-m mixing height across the entire wind speed
                range.
                    Concentrations for pollutants other than VOC would be smaller, as indicated above. The MMS regulations
                (30 CFR 250.44) do not establish annual significance levels for CO and VOC. For these pollutants, a
                comparison of emission rates will be used to assess impacts. Formulas to compute the emission rates in tons/yr
                for CO are 3,400-D2* and 33.3-D for VOC. In these formulas, D represents distance in statute miles from the
                shoreline to the source. The CO exempt emission level in Subarea C-1 is 7,072.8 tons/yr, which is greater than
                peak emissions from the whole CPA. The exemption emission level of VOC in Subarea C-1 is 100 tons/yr,
                while the platform emissions level is estimated as 48.8 tons/yr. Therefore, VOC impacts to the air quality
                would be low. Transport of pollutants toward onshore areas has a frequency maximum of 61 percent during
                summer and only 37 percent during winter. Thus, the box model results represent a worst case scenario. The
                modeling effort does not consider removal processes such as rain, which in the CPA has a high frequency
                (Section III.A.2.) and would reduce concentration levels reaching onshore.
                    Further, using an approved numerical model, the Offshore and Coastal Dispersion (OCD) Model (USDOI,
                MMS, 1986a), MMS studied the impacts of offshore emissions. Eight offshore areas in the OCS near Grand
                Isle, Louisiana, containing from 19 to 85 production complexes and 19 to 195 point sources, were used in the
                study. Source distance from the coastline ranged from 5.6 to 45 kin (3.5 to 28 mi). The study employed a 300-
                in mixing height, which coincides with the lower mixing height employed in the box model. Because the last
                model run in the study represents an aggregation of all sources and covers the entire distance range, this
                discussion emphasizes those results.
                    The highest 1-hour concentration observed was 71.89 ggm-3, while the annual arithmetic mean varied
                between 0.82 and 1.83 ggin  -3, which is below the N02 national standard of 100 pgm-@ All other inert pollutants
                would have lower concentrations. This modeling effort represents the combined effect of 85 production
                complexes close to onshore areas. Therefore, it is reasonable to assume that concentrations derived from
                emissions associated with the proposed action, 30 platform complexes (35% of that used in the model), spread
                over 193.4 billion square meters would have a much smaller effect.
                    Off-spill effects on air quality are examined below. It is assumed that oil spills in the category greater than
                1 and less than or equal to 50 bbl, as well as greater than 50 and less than 1,000 bbl, would have low impacts
                on air quality because their input of pollutants (it is assumed that 30% of the spill evaporates in three days)
                would be very small. Information from OCS accidents indicates emissions of fewer than 100 tons/hour by the
                second hour. For spills greater than or equal to 1,000 bbl, emissions are about 285 tons/hour or smaller. A
                single spill of 6,500 bbl is assumed. If the dispersion of emissions is taken into account, effects on offshore air
                quality would be temporary. Impacts to onshore areas from these spills would be very low because of the
                dispersion process, the limited input of pollutants to the atmosphere, and the transport regime present in the
                CPA. Nearly 1 percent of OCS crude-oil production is offloaded from surface vessels at ports. The estimated
                VOC emissions from offloading in the Base Case are 69.4 tons over the 35-year life of the proposed action.
                These emissions represent about 0.34 percent when compared to the total VOC emissions from the Base Case.










                  IV-202

                  Safeguards to ensure minimum emissions from the offloading and loading operations have been adopted by
                  the State of Louisiana (The Marine Vapor Recovery Act, 1989: LAC: 111.2108). Emissions from servicA,, vessels
                  are expected to produce negligible effects on air quality.
                      Suspended particulate matter is important because of its potential in degrading the visibility in national
                  wildlife refuges or recreational parks, designated as PSD Class I areas. The impact depends on emission rates
                  and particle size. Particle size used in this analysis represents the equivalent diameter, which is the diameter
                  of a sphere that will have the same settling velocity as the particle. Particle distribution in the atmosphere has
                  been characterized as being largely trimodal (Godish, 1991), with two peaks located at diameters smaller than
                  2jum and a third peak with diameters larger than 2 gm. Particles with diameters of 2jum or larger settle very
                  close to the source (residence time of approximately 1/2 day, Lyons and Scott, 1990), so their impact on these
                  areas would be low. For particles smaller than 2 gin, which do not settle fast, wind transport determines their
                  impacts. Results from the box model indicate that the largest concentration for TSP will be,0.22ggm'-3. which
                  is less than the allowable annual increase level of 5 jigm-3.
                      Blowouts are accidents related to OCS activities and are defted as an uncontrolled flow of fluids from a
                  wellhead or wellbore. In the Gulf of Mexico OCS there have been 116 blowouts over a period of '19 years
                  (1971-1981) (Section IV.A-2.d.(8)). This represents an average of about 6 blowouts per yea;r, but the number
                  of wells drilled is a better indicator. The number of blowouts estimated, at a rate of 7 blowouts per 1,000 wells
                  drilled, is 4 blowouts during the proposed action in the CPA. The air pollutant emissions from blowouts
                  depend on the amount of oil and gas released, duration of the accident, and the occurrence or not of fire
                  during the blowout.
                      Because of technological advances the duration of blowouts has decreased, and about 61 percent of recent
                  blowouts last 1 day or less, 19 percent last between 2 and 3 days, 7 percent last between 4 and 7 days, and 13
                  percent last more than 7 days (Fleury, 1983). Further, most blowouts occurred without fire (MMS Database).
                  The amount of oil released during these accidents has been small. Using the distribution of blowouts cited
                  earlier, three blowouts will last 1 day and one blowout will last 2.5 days. No statistics exist on the amount of
                  gas released during a blowout; however, for this analysis a rate of 1 billion cubic feet (Bcl) per day will be
                  assumed. The total emission of THC is 138 tons over the 35-year life of the proposed action. It must be
                  remembered that these are conservative estimates and that the total amount of THC may be less; the VOC
                  will also be less since it is a fraction of the THC.
                      Ozone is of great concern because of its environmental considerations. In the CPA six parishes have
                  nonattainment status for this pollutant (Section III.A-3.). Ozone measurements (La. Dept. of Environmental
                  Quality, 1989) between 1989 and 1990 were examined from Morgan City in St Martin Parish, Thibodaux in
                  Lafourche Parish, and Westlake in Calcasieu Parish. These measurements show that in Morgan City and
                  Thibodaux the ozone concentration never exceeded the national standard. Concentrations at these stations
                  were between 15 and 25 ligm-3 below the national standard (235 Agm-3) during episodes of highest ozone
                  concentrations. At other times concentrations were 45 to 50 units below the national standard. At Westlake
                  in Calcasieu Parish, which is north of Cameron Parish, the ozone concentrations exceeded the national
                  standards at least twice during 1989 and once during the first eight months of 1990. Another area with ozone
                  problems is Baton Rouge. Recent air modeling there (Haney et al., 1990) indicates that ozone concentrations
                  peak near 1600-1700 hours. The modeling effort, which included anthropogenic and biogenic sources, showed
                  that some events could result from atmospheric overturning. During overturning episodes, ozone from previous
                  days is mixed downward and, coupled with local and imported inputs of ozone, causes the concentrations to
                  exceed the national standards. Recently, MMS awarded one study to do a preliminary ozone modeling exercise
                  with USEPA using the Regional Oxident Model (ROM) for episodes with onshore transport. A second study
                  is near award for a 3-year study of ozone formation and transport from OCS activities in the Gulf of Mexico.
                     A recent report from the Lake Charles Ozone Task Force shows that out of 12 ozone exceedances in
                  Calcasieu Parish, 3 cases show significant ozone contributions by transport from Texas. Another 3 cases with
                  demonstrable transport ozone input occur, but the source areas are to the south or northwest. The report cites
                  the Lake Charles industrial area to the south and the Beaumont and Orange, Texas, areas as the possible
                  source areas in these cases. There were 5 other cases that showed local sources as the cause for the ozone
                  exceedance episode. One episode cannot be studied with the methods employed by the Task Force for this
                  analysis. Thus, there are 3 out of 12 cases where the ozone transport is correlated with southerly winds and










                                                                                                                        IV-203

                that can point to some inputs from OCS offshore sources. However, the report never indicates this as a
                possibility or even speculates about the OCS role. Ozone measurements made between 1989 and 1990 in
                Alabama show only one ozone exceedance episode near the Chickasaw station. Another station located on
                Highway 43 shows no episodes of ozone exceedance over the same period. Both stations showed that ozone
                is seasonal with a maximum during August and a decrease during the fall and winter, when ozone levels are
                about 50 percent below the national standard of 235 /Lgm-@

                Summary

                    Emissions of pollutants into the atmosphere from the activities associated with the proposed action are
                likely to have a low impact on offshore air quality because of the prevailing atmospheric conditions, emission
                heights, and pollutant concentrations. Onshore impact on air quality from emissions from OCS activities is
                estimated to be negligible because of the atmospheric regime, the emission rates, and the distance of these
                emissions from the coastline. The above discussion is based on average conditions; however, there will be days
                of low mixing heights and wind speeds that could increase impact levels. These conditions are characterized
                by fog formation, which in the Gulf occurs about 35 days a year, mostly during winter. Impact from these
                conditions is reduced in winter because the onshore winds have the smallest frequency (37%) and rain removal
                is greatest. Summer is the worst time, with onshore winds having a frequency of 61 percent.

                Conclusion

                    Emissions of pollutants into the atmosphere are expected to have concentrations that would not change
                the onshore air Vality classifications. Increases in onshore concentrations of air pollutants are estimated to
                be about I /Agm- (box model steady concentrations). This concentration will have minimal impacts during
                winter because onshore winds occur only about 37 percent of the time and maximum impacts in summer, when
                onshore winds occur 61 percent of the time.

                High Case Ana4uis

                    The scenario discussed in Section IV.A- (Table IV-2) for the High Case establishes that 540 exploration
                and delineation wells and 520 development wells would be drilled, and 50 platform complexes would be
                emplaced. The sale area has been subdivided into four offshore subareas: C-1, C-2, C-3, and C-4 (Figure IV-
                1). This discussion analyzes the potential degrading effects on air quality of OCS-related activities in each
                subarea. Table IV-2 presents for the High Case the numbers of exploration, delineation, and development
                wells; platforms installed; and service vessel trips for each subarea.
                    The following table shows total emissions from wells, platforms, vessels, and other activities in the CPA
                for the High Case. Observe that NO,, is the most emitted pollutant, while SO. is the least emitted. More
                important is that this information shows that wells and vessels contribute mostly NO.; while platforms
                contribute mostly NO, CO, and VOC. These emissions were calculated using an integration of well and
                platform emissions over time. Vessel emissions were calculated using the total number of service vessel trips
                presented in Table IV-2. Other emissions were calculated using information presented in Table IV-2 also.










                 IV-204


                                                         Total OCS Emissions in the CPA
                                            (tons over 35-year life of the proposed action--High Case)

                          Activi                           NO              Co           so             THC            TSP


                          Service Vessels            15,917.1            1,864.7      251.5          810.0         1,122.9
                          LTO Helicopters                  67.1            54.2         10.3           2.8            2.6
                          Cruise Helicopters             216.6            619.0         46.4           50.5           61.9
                          Blowouts without Fire            0.0              0.0         0.0            0.5            0.0
                          Spills without Fire              0.0              0.0         0.0          255.0            0.0
                          Barge Loading                    0.0              0.0         0.0            76.8           0.0
                          Tanker Loading                   0.0              0.0         0.0            76.8           0.0
                          Transit Loss                     0.0              0.0         0.0          199.2            0.0
                          Tanker Exhaust                   11.4             1.2         14.2           0.0            4.1
                          Tug Exhaust                    321.7             32.1         4.2            14.5           19.3
                          Exploratory Wells            5,221.8           1,393.2      610.2          151.2           523.8
                          Development Wells            3,436.0            916.8       403.2          100.8           345.6
                          Platforms                  84,463.8          11,002.4       147.8       32,012.5           206.9

                          Total                      109,656.3         15,883.6      1,487.8      33,750.6         2,287.1

                     Total emissions for each subarea in the CPA during the High Case are presented below. Observe that
                 Subarea C-1, which is the closest to land, generates the smallest emissions of all pollutants, while Subarea C-4,
                 the farthest from land, generates the greatest amounts of emissions.

                                                         Total Emissions in CPA Subareas
                                         (tons over the 35-year Life of the proposed action--High Case)

                          Pollutant                     C-1                C-2                 C-3              C-4


                          NO.                      13,158.8            19,738.1           39,476.3         37,283.1
                          CO                        1,906.0            2,859.0             5,718.1         5,400.4
                          sq,                        178.5                267.8             535.6             505.9
                          TFIC                      4,050.1            6,075.1            12,150.7         11,475.2
                          TSP                        274.5                411.7             823.4             777.6

                     The total pollutant emissions per year are not uniform. During the early years of the proposed action,
                 emissions would be small and increase over time with production. After reaching a maximum, emissions would
                 decrease rapidly to zero as all platforms and wells are removed and service vessel trips and other related
                 activities are no longer needed.
                     The following table presents the peak emissions in tons per year for the primary pollutanis during the High
                 Case. It is very important to note that well drilling activities and platform peak emissions are not necessarily
                 simultaneous. However, it is assumed that service vessel emissions and well and platform peak emissions occur
                 simultaneously. In this analysis the aggregate peak emissions, which are two to five times the: mean emissions,
                 will be employed.










                                                                                                                       IV-205


                                                   Peak and Mean Emissions in the CPA
                                                                 (tons/year)

                    Pollutant        Wells        Platforms        Vessels         Others         Mean         Aggregate

                       NO,,        1,070.78        4,287.50        472.40           0.00        3,133.04        4,903.10
                       CO           285.68           558.50        73.46            0.00          453.82          670.16
                       sq,           125.76            7.50          9.33           0.00           42.51          127.23
                       THC            31.08        1,625.00        25.08            25.08         972.00        1,679.36
                       TSP           107.46           10.50        34.59            0.00           65.35          136.29

                    The mean emissions were computed by dividing the total emissions by the 35-year life of the proposed
                action. Peak emissions from wells and platforms are obtained from their temporal distribution. Platforms and
                wells have the greatest peak emissions, while vessels have smaller emissions. The other activities have very
                small emissions except for THC. The peak emission rates are contrary to the emission rates, where wells have
                greater rates than platforms.
                    The effects of the pollutants considered in this analysis were described in the Base Case analysis and will
                not be repeated here. The reader may consult that section.
                    Because the meteorological conditions described in the Base Case will not change for this analysis, neither
                will they be repeated. The only changes that occur in the High Case are those related to infrastructures and
                resources. These changes are reflected in an increase of emissions for all analyzed pollutants. A comparison
                of High Case emissions per year with those of the Base Case shows that these would increase by 1.5 to 2 times.
                    To estimate the potential impact of offshore emissions on offshore and onshore air quality, a steady state
                box model (Lyons and Scott, 1990) was employed. The model is an expression of mass conservation and
                assumes that pollutants are vertically dispersed and sources uniformly distributed. Lack of knowledge about
                the final source positions allows the distribution of sources uniformly throughout the planning area.
                Predominance of unstable atmospheric conditions over the sea, as discussed in Section III.A.2., ensures that
                pollutants are dispersed homogeneously. The model was applied to NO. emissions because these are the
                largest emissions. Because VOC emissions are not inert, the box model cannot be used to assess their impacts
                on air quality. Concentrations for other pollutants can be estimated by multiplying the NO,, concentrations by
                the ratio of the pollutant emissions over the NO,, emissions. Concentrations of primary pollutants other than
                NO,, would be smaller by more than 65 percent. Impacts from VOC and CO will be estimated by comparing
                the offshore and onshore emission rates.
                    The box model was applied to the following conditions: onshore and offshore winds with speeds ranging
                from 1 to 7 ms-1, a mean mixing height of 900 in, and a low mixing height of 300 in. During offshore wind
                conditions, impacts to the onshore air quality from offshore CPA emissions are very low because the pollutants
                are transported offshore. Concentrations over water in the different subareas started at 0.03 LgM-3 near the
                coastline and increased to 0.36 ggm-3 over Subarea C4 for a wind speed of 1 ms-1 and a mixing height of 900
                in. The greater the wind speed, the lower the concentration, and the smaller the mixing height, the larger the
                concentration. But even during the lowest wind speed and mixing height conditions, concentrations reached
                only 1.07 jLgm-@ Conditions of onshore winds indicate that concentrations reaching land from Subarea C-3
                varied between 0.40 and 0.04 pgm-3 for speeds from I to 7 ms-1 and a mixing height of 900-m; for a 300-in
                mixing height, concentrations varied from 1.12 to 0.21 jigm-3 under the same wind speeds. For Subarea C-1
                the concentrations varied from 0.23 to 0.01 jigin-3 with a 900-in mixing height across the entire wind speed
                range; concentrations varied from 0.04 to 0.70 ;Lgin-3 with a 300-in mixing height across the entire wind speed
                range.
                    Concentrations for pollutants other than VOC would be smaller, as indicated above. Impacts to air quality
                for NO,, SO, and TSP are low because the concentrations arriving onshore are less than USDOI significance
                levels for these pollutants. The MMS regulations (30 CFR 250.44) do not establish annual significance levels
                for CO and VOC. For these pollutants, comparison of emission rates will be used to assess impacts. Formulas
                to compute the emission rates in tons/yr for CO are 3,400-Dw and 33.3-D for VOC. In these formulas, D
                represents distance in statute miles from the shoreline to the source. The CO exempt emission level in Subarea










                 IV-206

                 C-1 is 7,072.8 tons/yr, which is greater than peak emissions from the whole CPA. The exemption emission level
                 of VOC in Subarea C-1 is 100 tons/yr, while the platform emissions level is estimated at 32.5 tons/yr. Transport
                 of pollutants toward onshore areas has a frequency maximum of 61 percent during summer and only 37percent
                 during winter. Thus, the box model results represent a worst case scenario. The modeling effort does not
                 consider removal processes such as rain, which in the CPA has a high frequency (Section III.A.2.) and would
                 reduce concentration levels reaching onshore.
                     Further, using an approved numerical model, the OCD Model (USDOI, MMS, 1986a), MMS studied the
                 impacts of offshore emissions. Eight offshore areas near Grand Isle, Louisiana, containing from 119 to 85
                 production complexes and 19 to 195 point sources, were used in the study. Source distance ftom the coastline
                 ranged from 5.6 to 45 km (3.5 to 28 mi). The study employed a 300-m mixing height, which coincides with the
                 lower mixing height employed in the box model. Because the last model run in the study represents an
                 aggregation of all sources and covers the entire distance range, this discussion emphasizes those results.
                     The highest 1-hour concentration observed was 71.89 jugm-3, while the annual arithmetic mean. varied
                 between 0.82 and 1.83,ugm-3, which is below the national standard of 100 ggm-@ All other inert P01111tants will
                 have lower concentrations. This modeling effort represents the combined effect of 85 production complexes
                 close to onshore areas. Therefore, it is reasonable to assume that concentrations derived from emissions
                 associated with the proposed action, 60 platforms (71% of that used in the model), spread over 193.4 billion
                 square meters would have a much smaller effect.
                     Oil-spill effects on air quality are examined below. It is assumed that oil spills in the category greater than
                 1 and less than or equal to 50 bbl, as well as greater than 50 and less than 1,000 bbl, would have low impacts
                 on air quality because their input of pollutants (it is assumed that 30% of the spill evaporates in three days)
                 would be very small. Information from OCS accidents indicates emissions of fewer than 100 tons/hour by the
                 second hour. For spills greater than or equal to 1,000 bbl, emissions are about 285 tons/hour or smaller. A
                 single spill of 6,500 bbI is assumed. Under the High Case, it is estimated that about 255 torts of THC , would
                 be emitted in a 2-hour period sometime during the 35-year life of the proposed action. If the dispersion of
                 emissions is taken into account, effects on offshore air quality would be temporary.
                     Nearly I percent of OCS crude-oil production is offloaded from surface vessels at ports. The estimated
                 VOC emissions from offloading in the High Case are 153.6 tons over the 35-year life of the proposed action.
                 These emissions represent about 0.45 percent when compared to the total VOC emissions from the High Case.
                 Safeguards to ensure minimum emissions from the offloading and loading operations have been adopted by
                 the State of Louisiana (The Marine Vapor Recovery Act, 1989: LAC: 111.2108). Current industry practice is
                 to extend pipelines to new production facilities when feasible; barging, then, would be needed only during the
                 construction phase. Emissions from service vessels are expected to produce negligible effects on air quality.
                     Suspended particulate matter is important because of its potential in degrading the visibility in national
                 wildlife refuges or recreational parks designated as PSD Class I areas. The impact depends on emission rates
                 and particle size. Particle size used in this analysis represents the equivalent diameter, which is the diameter
                 of a sphere that will have the same settling velocity as the particle. Particle distribution in the atmosphere has
                 been characterized as being largely trimodal (Godish, 1991), with two peaks located at diameters smaller than
                 2 Am and a third peak with a diameter larger than 2 Am. Particles with diameters of 2 Am orlarger settle very
                 close to the source (residence time of approximately 1/2 day, Lyons and Scott, 1990), so their impact on these
                 areas would be low. For particles smaller than 2 Am, which do not settle fast, wind transport determines their
                 impacts. Results from the box model indicate that the largest concentration for TSP will be 0.25 ggm--". which
                 is less than the allowable annual increase level of 5 pgm-@
                     Blowouts are accidents related to OCS activities and are defined as an uncontrolled flow of fluids from a
                 wellhead or wellbore. In the Gulf of Mexico OCS there have been 116 blowouts over a period of 19 years
                 (1971-1981) (Section IV.A.2.d.(8)). This represents an average of about 6 blowouts per year, but the number
                 of wells drilled is a better indicator. The estimated number of blowouts, at a rate of 7 blowouls per 1,000 wells
                 drilled, is 8 blowouts during the High Case in the CPA. The air pollutant emissions from blowouts depend on
                 the amount of oil and gas released, the duration of the accident, and the occurrence or not of fire during the
                 blowout.
                     Because of technological advances, the duration of blowouts has decreased, and about 61 percent of the
                 recent blowouts last 1 day or less, 19 percent last between 2 and 3 days, 7 percent last between 4 and 7 days,










                                                                                                                       IV-207

                and 13 percent last more than 7 days (Fleury, 1983). Further, most blowouts occurred without fire (MMS
                Database). The amount of oil released during these accidents has been small. Using the distribution of
                blowouts cited earlier, five blowouts will last 1 day, two blowouts will last 2.5 days, and one blowout will last
                5.5 days. The total emission of THC is 270 tons over the 35-year life of the proposed action. It must be
                remembered that these are conservative estimates and that the total amount of THC may be less; the VOC
                will also be less because it is a fraction of the THC.
                    Ozone is of great concern because of its environmental considerations. In the CPA six parishes have
                nonattainment status for this pollutant (Section III.B.3.). Ozone measurements (La. Dept. of Environmental
                Quality, 1989) between 1989 and 1990 were examined from Morgan City in St. Mary Parish, Thibodaux in
                Lafourche Parish, and Westlake in Calcasieu Parish. These measurements show that in Morgan City and
                Thibodaux the ozone concentration never exceeded the national standard. Concentrations were between 15
                and 25 pgm-3, below the national standard during episodes of highest ozone concentrations. At other times
                concentrations were 45 to 50 units below the national standard. At Westlake in Calcasieu Parish, which is
                north of Cameron Parish, the ozone concentrations exceeded the national standards at least twice during 1989
                and once during the first eight months of 1990. Another area with ozone problems is Baton Rouge. Recent
                air modeling there (Haney et al., 1990) indicates that ozone concentrations peak near 1600-1700 hours. The
                modeling effort, which included anthropogenic and biogenic sources, showed that some events could result from
                atmospheric overturning. During overturning episodes, ozone from previous days is mixed downward and,
                coupled with local and imported input of ozone, causes the concentrations to exceed the national standards.
                    A recent report from the Lake Charles Ozone Task Force shows that out of 12 ozone exceedances in
                Calcasieu Parish, 3 cases show significant ozone contributions by transport from Texas. Another 3 cases with
                demonstrable transport ozone input occur, but the source areas are to the south or northwest. The report cites
                the Lake Charles industrial area to the south and the Beaumont and Orange, Texas, areas as the possible
                source areas in these cases. There were, 5 other cases that showed local sources as the cause for the ozone
                exceedance episode. One episode cannot be studied with the methods employed by the Task Force for this
                analysis. Thus, there are 3 out of 12 cases where the ozone transport is correlated with southerly winds and
                that can point to some inputs from OCS offshore sources. However, the report never indicates this as a
                possibility or even speculates about the OCS role. Ozone measurements made between 1989 and 1990 in
                Alabama show only one ozone exceedance episode near the Chickasaw station. Another station located on
                Highway 43 shows no episodes of ozone exceedance ever the same period. Both stations showed that ozone
                is seasonal with a maximum during August and a decrease during the fall and winter, when ozone levels are
                about 50 percent below the national standard of 235 ggm-3.

                Conclusion

                    Emissions of pollutants into the atmosphere from the activities assumed for the High Case are expected
                to have concentrations that would not change onshore air quality classifications. Increases in onshore
                concentrations of air pollutants from the High Case are estimated to be about 1 Am       3 (box model steady
                concentrations). This concentration will have minimal impact during winter because onshore winds occur only
                37 percent of the time and a maximum impact in summer, when onshore winds Occur 61 percent.

                (5) Impacts on Coastal and Mayine Mammals

                (a) Matine Mammals

                Nonendangered and Nonthreatened Species

                    This section discusses the effects of the proposed action on nonendangered marine mammals. Twenty-eight
                nonendangered species of marine mammals of the Order Cetacea, which includes whales and dolphins, have
                been identified in the Gulf of Mexico (Table III-1). By an order of magnitude, the bottlenose dolphin is the










                IV-208


                most common cetacean in this area. Its distribution and movement suggest that there are several distinctive
                populations in the Gulf.
                    The major impact-producing factors related to the proposed action that may affect Gull'nonendangered
                cetaceans include operational discharges, helicopterand service-vessel traffic, platform noise, explosive platform
                removals, seismic surveys, oil spills and oil-spill response activities. These impact-producing factors are
                discussed in detail by the National Research Council (1985), Boesch and Raba" (1987), Geraci and St. Aubin
                (1988), USDOI, MMS (1982a and 1987d), and API (1989), and are described below.
                    Produced waters, drilling muds, and drill cutting discharges can potentially impact cetaceans, by displacing
                or reducing their food sources. Offshore operational discharges are not lethal to cetaceans and are diluted and
                dispersed rapidly to the extent that adverse effects to cetacean food sources do not occur (API, 1989; NRC,
                1983). The suspended particulate matter in the discharge plume could temporarily inhibit the ability of a
                cetacean to locate its prey visually or acoustically.
                    Noise from helicopter and service-vessel traffic may elicit a startle reaction from cetaceans or mask their
                sound reception. This effect is sublethal and at worst of a short-term, temporary nature, (Gales, 1982).
                Dolphins are known to actively seek out and accompany service vessels for some distance with no adverse
                effects. Service vessels could collide with and directly impact cetaceans, but due to dolphin maneuverability
                and echo-location, encounters of this type seldom occur (Slijper, 1979; Kraus, personal comm., 1987).
                    Exploration, delineation, and production structures produce sounds at intensities and frequencies that can
                be heard by cetaceans. The decibel levels of these sounds dissipate to the tolerance of most cetaceans within
                15 in of the sound source. Odontocetes (toothed cetaceans) communicate and echo-locate at frequencies
                higher than the dominant sounds generated by offshore drilling and production activities., For example,
                bottlenose dolphins are sensitive to sound levels in the 143-180 db range; this high range is unlikely to be
                generated by offshore drilling operations (Gales, 1982).
                    Explosive platform removals can interfere with communications, disturb behavior, reduce hearing sensitivity
                or cause hemorrhaging in cetaceans (USDOI, MMS, 1990c). The effects are primarily sublethal and
                short-term; however, cetaceans proximate to detonationwould likely sustain fatal injuries. Mortalities and fatal
                injuries have been speculated, but none has been documented. In order to minimize the likelihood of removals
                occurring when cetaceans may be nearby, MMS has issued guidelines for explosive platform removal to
                offshore operators. These guidelines include daylight detonation only, staggered charges, placement of charges
                5 in below the seafloor, and pre- and post-detonation surveys of surrounding waters.
                    The sources of acoustical pulse used in seismic surveys are generated by airguns. Should seismic-generated
                sound waves exceed the ambient "background"noise they may interfere with cetacean communicationor disturb
                behavior. Although ambient sound levels in marine environments are highly variable, effects from seismic
                surveys are limited because seismic sound pressure dissipates to under 200 dB at distances beyond 30 in from
                the acoustic source (Gales, 1982). Of course, cetaceans in proximity to the source of acowstic: transmission
                could be disturbed by noise. However, the pressure encountered by cetaceans during dives and from natural
                underwater sounds are often in excess of those produced by seismic activities at the acoustic source. In
                addition, cetacean populations are highly dispersed, and individual cetaceans easily avoid acoustic interference.
                The effects on cetaceans. from seismic surveys are primarily sublethal and mostly constitute short-term
                avoidance behavior.
                    Oil spills and oil-spill response activities can adversely affect cetaceans, causing skin and eye irritation,
                asphyxiation from inhalation of toxic fumes, food reduction or contamination, oil ingestion, and displacement
                from preferred habitats or migration routes (Goodale et al., 1981; Gruber, 1981; Geraci and St. Aubin, 1988).
                When an oil spill occurs, many factors interact to delimit the severity of effects and the extent of damage to
                cetaceans. Determining factors include geographic location, oil type, oil dosage, impact area, oceanographic
                conditions, meteorological conditions, and season (NRC, 1985; USDOI, MMS, 1987b). Cetacaans themselves
                may actively avoid an oil spill, thereby limiting the effects and lessening the extent of damage to their
                populations. Less severe, sublethal effects are defined as those that impair the ability of an organism to
                function effectively without causing direct mortality (NRC, 1985).
                    Gcraci and St. Aubin (1988) noted that determining the risk to cetaceans from an interaction with oil was
                extremely difficult because of the host of variables involved in the interaction. Generally, species with large
                ranges and mobility that feed in the water column versus at the surface or on the bottom are less vulnerable










                                                                                                                            IV-209

                 to oil. This suggests that Mysticetes (baleen whales) are the most vulnerable, followed by bottlenose dolphins
                 and wide-ranging odontocetes. Although the coastal habitats of the bottlenose dolphin are more likely to be
                 oiled than offshore areas, Geraci and St. Aubin (1982) suggest that dolphins are able to detect and avoid oil.
                 Skin and eye irritation and respiratory disorders caused by contacting oil are sublethal and of a temporary
                 nature (Geraci and St. Aubin, 1988). Death or debilitating illness caused by oil ingestion or by consumption
                 of contaminated food requires large volumes and long-term chronic interactions. Long-term interactions, which
                 could shorten life expectancy or reduce fecundity, have not been studied.

                      Base Case Ana4uis
                      The major impact-producing factors analyzed below are related to the proposed action and include
                 operational discharges, helicopter and vessel traffic, platform noise, explosive platform removals, seismic
                 surveys, oil spills, and oil-spill response activities.
                      An estimated 4,113 bbl of drilling muds, 988 bbl of drill cuttings, and 317 MMbbI of produced waters are
                 assumed to be generated offshore as a result of the proposed action (Table IV-2). These effluents are
                 routinely discharged into offshore marine waters and are regulated by the U.S. Environmental Protection
                 Agency's NPDES permits. It is expected that nonendangered cetaceans will have some interaction with these
                 discharges. Direct effects to cetaceans are expected to be sublethal, and effects to cetacean food sources are
                 not expected due to the rapid offshore dilution and dispersion of operational discharges. It is expected that
                 operational discharges will seldom contact and affect nonendangered cetaceans.
                      It is assumed that helicopter traffic will occur on a regular basis, averaging about 18,000 trips per year.
                 The FAA Advisory Circular 91-36C encourages the use of fixed-wing aircraft above an elevation of 152 m and
                 helicopters above 300 in. It is expected that at these elevations no cetaceans will be affected by OCS helicopter
                 traffic. It is also expected that helicopter traffic will seldom disturb and affect nonendangeredcetaceans because
                 of special prohibitions and adherence to the general, FAA-recommended minimum ceding of 300 in.
                      It is assumed that about 500 OCS-related od/gas service-vessel trips will occur annually and that 2 shuttle
                 tanker trips will occur during the 35-year life of the proposed action (Table IV-2). Noise from service-vessel
                 traffic may elicit a startle reaction from cetaceans or mask their sound reception. This effect is sublethal and,
                 at worst, of a short-term temporary nature. Cetaceans; can avoid service vessels, and operators can avoid
                 cetaceans. It is expected that service-vessel traffic will seldom contact and affect nonendangered cetaceans.
                      It is assumed that 340 exploration and delineation wells and 250 development wells will be drilled and win
                 produce sounds at intensities and frequencies that could be heard by cetaceans. It is expected that noise from
                 drilling activities will last no longer than two months at each location. However, the decibel level of these
                 sounds dissipates to the tolerance of most cetaceans; within 15 in of the source. Odontocetes communicate at
                 higher frequencies than the dominant sounds generated by drilling platforms. Sound levels in this range are
                 not likely to be generated by drilling operations (Gales, 1982). The effects on cetaceans, from platform noise
                 are expected to be sublethal. It is expected that drilling noise will seldom disturb and affect nonendangered
                 cetaceans.
                      Explosive platform removals can interfere with communication, disturb behavior, reduce hearing sensitivity,
                 or cause hemorrhaging in cetaceans. It is estimated that 20 structures will be removed by explosives from the
                 Gulf of Mexico as a result of the proposed action. These removals are assumed to occur during the last 12
                 years of the life of the proposed action and no more than 5 in any single year (Table IV-12). It is expected
                 that structure removals will cause sublethal effects on cetaceans. No mortalities are expected because of the
                 MMS guidelines for explosive removals (USDOI, MMS, 1990a, Appendix B). It is expected that structure
                 removals will seldom disturb and affect nonendangered cetaceans.
                      ,Seismic surveys use airguns; to generate pulses. It is assumed that only these methods will be used in
                 seismic surveys as a result of the proposed action (Section IV.A-2.). It is expected that effects on cetaceans
                 from seismic surveys are primarily sublethal, constituting short-term avoidance behavior.
                      Oil spills and oil-spill response activities can adversely affect cetaceans, causing skin and eye irritation,
                 asphyxiation from inhalation of toxic fumes, food reduction or contamination, oil ingestion, and displacement
                 from preferred habitats or migration routes. In the event that oiling of cetaceans, should occur from sale-
                 related oil spills greater than or equal to 1,000 bbl (one spill of 6,500 bbl is assumed), the effects would










                 IV-210

                 primarily be sublethal; few mortalities are expected. The effects of sale-related oil spills less than 1,000 bbl
                 are expected to be solely sublethal due to the inconsiderable area affected and their rapid dispersion. It is
                 expected that the extent and severity of effects from sale-related oil spills of any size will be lessened by
                 improved coastal oil-spill contingency planning (Section IV.C.5.) and by active avoidanex-. of oil spills by
                 cetaceans.
                     Section IV.C. I. estimates the mean number of spills less than 1,000 bbI occurring from the: proposed action
                 in the CPA. It is assumed that 21 spills greater than 1 and less than or equal to 50 bbl will occur during the
                 35-year life of the proposed action. It is estimated that the 21 spills will occur offshore and that a tew will
                 contact land. It is assumed that 1 spill greater than 50 and less than 1,000 bbl will occur during the 35-year
                 life of the proposed action, and it is estimated that the spill will occur offshore and that none of it will contact
                 land. Although an interaction with spills less than 1,000 bbl may occur, only sublethal effects are expected.
                 It is estimated that small spills will infrequently contact and affect nonendangered cetaceans.
                     Section IV.C.1. estimates the mean number of spills greater than or equal to 1,000 bbl resulting ft-ont the
                 proposed action in the CPA. It is assumed that 1 crude oil spill (median size of 6,500 bbl) will occur from a
                 pipeline in the Central Gulf during the 35-year fife of the proposed action. Table IV-21 identilles the estimated
                 risk of one or more oil spills greater than or equal to 1,000 bbl occurring and contacting areas within 10 days
                 where cetaceans have been surveyed. There is a 5 percent probability that an oil spill greater than or equal
                 to 1,000 bbI will occur and contact within 10 days cetacean habitats at or beyond the shelf break of the CPA.
                 There is a 1-2 percent probability that an oil spill greater than or equal to 1,000 bbl will occur and contact
                 areas of the Mississippi Delta (survey blocks in Table IV-21) within 10 days of where cetaceans have been
                 sighted. Although an interaction with spills greater than or equal to 1,000 bbI may occur, infrequent mortalities
                 are expected with primarily sublethal effects. It is expected that an oil spill greater than or equal to 1,000 bbI
                 will seldom contact and affect nonendangered cetaceans in the CPA.

                     Summary

                     Activities resulting from the proposed action have a potential to affect endangered cetaceans detrimentally.
                 These cetacearts could be impacted by operational discharges, helicopter and vessel traffic., platform noise,
                 explosive platform removals, seismic surveys, oil spills, and oil-spill response activities. The effects of the
                 majority of these activities are expected to be sublethal. Lethal effects are estimated only from. oil spills greater
                 than or equal to 1,000 bbl. Sale-related oil spills of any size are expected to seldom contact nonendangered
                 and nonthreatened cetaceans.


                     Conclusion


                     The impact of the Base Case scenario on nonendangered and nonthreatened cetaccans within the
                 potentially affected area is expected to result in sublethal effects that are chronic and could cause persistent
                 physiological or behavioral changes, as well as some degree of avoidance of the impacted area(s).

                     High Case Analysis

                     The major impact-producing factors analyzed below are related to the proposed action and include
                 operational discharges, helicopter and vessel traffic, platform noise, explosive platform removals, seismic
                 surveys, oil spills and oil-spill response activities.
                     An estimated 7,362,000 bbl of drilling muds, 1,744,000 bbl of drill cuttings, and 660 MMbbl of produced
                 waters are assumed to be generated offshore as a result of the proposed action (Table IV-2). These effluents
                 are routinely discharged into offshore marine waters and are regulated by the U.S. Environmental Protection
                 Agency's NPDES permits. It is expected that nonendangered cetaceans will have some interaction with these
                 discharges. Direct effects to cetaceans are expected to be sublethal, and effects to cetacean 15ood sources are
                 not expected due to the rapid offshore dilution and dispersion of operational discharges. It is expected that
                 operational discharges will seldom contact and affect nonendangered cetaceans.










                                                                                                                             IV-211

                    It is assumed that helicopter traffic will occur on a regular basis, averaging about 31,000 trips per year.
                The FAA Advisory Circular 91-36C encourages the use of fixed-wing aircraft above an elevation of 152 m and
                helicopters above 300 m. It is expected that at these elevations no cetaceans will be affected by OCS helicopter
                traffic. It is also expected that helicopter traffic will seldom disturb and affect nonendangeredcetaceans because
                of special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 m.
                    It is assumed that about 880 OCS-related oil/gas service-vessel trips will occur annually as a result of the
                proposed action and that 5 shuttle tanker trips will occur during the 35-year life of the proposed action (Table
                IV-2). Noise from service-vessel traffic may elicit a startle reaction from cetaceans or mask their sound
                reception. This effect is sublethal and at worst of a short-term, temporary nature. Cetaceans can avoid service
                vessels, and operators can avoid cetaceans. It is expected that service-vessel traffic will seldom contact and
                affect nonendangered cetaceans.
                    It is assumed that 540 exploration and delineation wells and 520 development wells will be drilled and Will
                produce sounds at intensities and frequencies that could be heard by cetaceans. It is estimated that noise from
                drilling activities will last no longer than two months at only one location. However, the decibel level of these
                sounds dissipates to the tolerance of most cetaceans within 15 in of the source. Odontocetes communicate at
                higher frequencies than the dominant sounds generated by drilling platforms. Sound levels in this range are
                not likely to be generated by drilling operations (Gales, 1982). The effects on cetaceans from platform noise
                are expected to be sublethal. It is expected that drilling noise will seldom disturb and affect nonendangered
                cetaceans.
                    Explosive platform removals can interfere with communication, disturb behavior, reduce hearing sensitivity,
                or cause hemorrhaging in cetaceans. It is estimated that 24 structures will be removed by explosives from the
                Gulf of Mexico as a result of the proposed action. These removals are assumed to occur during the last 12
                years of the life of the proposed action and no more than 8 in any single year (Table IV-2). It is expected that
                structure removals will cause sublethal effects on cetaceans. No mortalities are expected because of the MMS
                guidelines for explosive removals (USDOI, MMS, 1990a, Appendix B). It is expected that structure removals
                will seldom disturb and affect nonendangered cetaceans.
                    Seismic surveys use airguns to generate pulses. It is assumed that only these methods will be used in
                seismic surveys as a result of the proposed action (Section IV.A.2.). It is expected that effects on cetaceans
                from seismic surveys are primarily sublethal, constituting short-term avoidance behavior.
                    Oil spills and oil-spill response activities can adversely affect cetaceans, causing skin and eye irritation,
                asphyxiation from inhalation of toxic fumes, food reduction or contamination, oil ingestion, and displacement
                from preferred habitats or migration routes. In the event that oiling of cetaceans should occur from sale-
                related oil spills greater than or equal to 1,000 bbI (one spill of 6,500 bbl is assumed), the effects would
                primarily be sublethal; few mortalities are expected. The effects of sale-related oil spills less than 1,000 bbi
                are expected to be solely sublethal due to the small area affected and their rapid dispersion. It is expected that
                the extent and severity of effects from sale-related oil spills of any size will be lessened by improved coastal
                oil-spill contingency planning (Section IV.C.5.) and by active avoidance of oil spills by cetaceans.
                    Section IV.Cl. estimates the mean number of spills less than 1,000 bbI occurring from the proposed action
                in the CPA. It is assumed that 47 spills greater than 1 and less than or equal to 50 bbI will occur during the
                35-year fife of the proposed action. It is estimated that the 47 spills will occur offshore and that a few will
                contact land. It is assumed that 2 spills greater than 50 and less than 1,000 bbl will occur during the 35-year
                life of the proposed action, and it is estimated that the spill will occur offshore and that none will contact land.
                Although an interaction with these spills may occur, only sublethal effects are expected. It is estimated that
                spills less than 1,000 bbI will infrequently contact and affect nonendangered cetaceans.
                    Section IV.C.l. estimates the mean number of spills greater than or equal to 1,000 bbI resulting from the
                proposed action in the CPA@ It is assumed that one crude oil spill greater than or equal to 1,000 bbl (6,500
                bbl) will occur from either a platform or pipeline in the Central Gulf during the 35-year life of the proposed
                action. Table IV-21 identifies the risk of one or more oil spills greater than or equal to 1,000 bbI occurring
                and contacting within 10 days areas where cetaceans have been surveyed. There is an 11 percent probability
                that an oil spill greater than or equal to 1,000 bbI will occur and contact, within 10 days, cetacean habitats at
                or beyond the shelf break of the CPA. There is a 1-4 percent probability that an oil spill greater than or equal
                to 1,000 bbI will occur and contact the Mississippi Delta (survey blocks in Table IV-21) within 10 days where










                 IV-212

                 cetaceans have been sighted and a 1-4 percent probability of occurrence and contact within 10 days in coastal
                 areas of Louisiana (Table IV-21). Although an interaction with spills greater than or equal to 1,000 bbI may
                 occur, infrequent mortalities are expected, with primarily sublethal effects. It is expected that an oil spill
                 greater than or equal to 1,000 bbI will seldom contact and affect nonendangered cetaceans in the CPA_
                     Activities resulting from the proposed action have a potential to affect nonendangered cetaceans
                 detrimentally. These cetaceans could be impacted by operational discharges, helicopter and vessel traffic,
                 platform noise, explosive platform removals, seismic surveys, oil spills, and oil-spill response activities. The
                 effects of the majority of these activities are expected to be sublethal. Lethal effects are expected only from
                 oil spills greater than or equal to 1,000 bbl. Sale-related oil spills of any size are expected to seldom. contact
                 nonendangered and nonthreatened cetaceans.

                     Conclusion


                     The impact of the High Case scenario on nonendangered and nonthreatened cetaceans within the
                 potentially affected area is expected to result in sublethal effects that are chronic and may result in persistent
                 physiological or behavioral changes, as well as some degree of avoidance of the impacted area(s).

                 Endangered and Threatened Species

                     This section discusses the effects of the proposed action on blue, right, sei, humpback, fin, and sperm
                 whales. For a detailed discussion of these species, see Section III.B.3.a.(2). The sperm whale is the species
                 most commonly seen in the Gulf of Mexico.
                     The major impact-producing factors related to the proposed action are discussed in detail by the National
                 Research Council (1985), Boesch and Rabalais (1987), Geraci and St. Aubin (1988), USDOI, MMS (1982a and
                 1987d), and API (1989), and are described in the preceding section (Section IV.D.La.(5)(all, nonendangered
                 and nonthreatened species).

                     Base Case Analysis

                     The major impact-producing factors analyzed below are related to the proposed action and include
                 operational discharges, helicopter and vessel traffic, platform noise, explosive platform removals, seismic
                 surveys, off spills, and oil-spill response activities.
                     An estimated 4,113,000 bbI of drilling muds, 988,000 bbI of drill cuttings, and 317 MMbbI of produced
                 waters are assumed to be generated offshore as a result of the proposed action (Table IV-2). These effluents
                 are routinely discharged into offshore marine waters and are regulated by the U.S. Environmental Protection
                 Agency's NPDES permits. It is expected that endangered cetaceans; will have some interaction with these
                 discharges. Direct effects to cetaceans are expected to be sublethal, and effects to cetacean food sources are
                 not expected due to the rapid offshore dilution and dispersion of operational discharges. It is expected that
                 operational discharges will seldom contact and affect endangered cetaceans.
                     It is assumed that helicopter traffic will occur on a regular basis, averaging about 18,000 trips per year.
                 The FAA Advisory Circular 91-36C encourages the use of fixed-wing aircraft above an elevation of 152 in and
                 helicopters above 300 in. It is expected that at these elevations no cetaceans, will be affected by OCS helicopter
                 traffic. It is also expected that helicopter traffic will seldom disturb and affect endangered cetaceans because
                 of special prohibitions and adherence to the general FAA-recommended minimum ceiling of 300 in.
                     It is assumed that about 500 OCS-related oil/gas service-vessel trips will occur annually as a result of the
                 proposed action and that 2 shuttle tanker trips will occur during the 35-year life of the proposed action (Table
                 IV-2). Noise from service-vessel traffic may elicit a startle reaction from cetaceans or mask their sound
                 reception. This effect is sublethal, and at worst, of a short-term, temporary nature. Cetaceans can avoid
                 service vessels, and operators can avoid cetaceans. It is expected that service-vessel traffic will seldom contact
                 and affect endangered cetaceans.
                     It is assumed that 340 exploration and delineation wells and 250 development wells will be drilled and will
                 produce sounds at intensities and frequencies that could be heard by cetaceans. It is estimated that noise from










                                                                                                                             IV-213

                drilling activities will last no longer than two months at each location. However, the decibel level of these
                sounds dissipates to the tolerance of most cetaceans within 15 in of the source. Odontocetes communicate at
                higher frequencies than the dominant sounds generated by drilling platforms. Sound levels in this range are
                not likely to be generated by drilling operations (Gales, 1982). The effects on cetaceans from platform noise
                are expected to be sublethal. It is expected that drilling noise will seldom disturb and affect endangered
                cetaceans.
                    Explosive platform removals can temporarily interfere with communication, disturb behavior, permanently
                reduce hearing sensitivity, or cause hemorrhaging in cetaceans. It is estimated that 20 structures win be
                removed by explosives from the Gulf of Mexico as a result of the proposed action. These removals are
                assumed to occur during the last 12 years of the life of the proposed action and no more than five in any single
                year (Table IV-2). It is expected that structure removals will cause sublethal effects on cetaceans. No
                mortalities are expected because of the MMS guidelines for explosive removals (USDOI, MMS, 1990a,
                Appendix B). It is expected that structure removals will seldom disturb and affect endangered cetaceans.
                    Seismic surveys use airguns to generate pulses. It is assumed that only these methods will be used in
                seismic surveys as a result of the proposed action (Section IV.A-2.). It is expected that effects on cetaceans
                from seismic surveys are primarily sublethal, constituting short-term avoidance behavior.
                    Oil spills and oil-spill response activities can adversely affect cetaceans, causing skin and eye irritation,
                asphyxiation from inhalation of toxic fumes, food reduction or contamination, oil ingestion, and displacement
                from preferred habitats or migration routes. In the event that oiling of cetaceans should occur from sale-
                related oil spills greater than or equal to 1,000 bbl (1 spill of 6,500 bbl is assumed), the effects would primarily
                be sublethal; few mortalities are expected. The effects of sale-related oil spills less than 1,000 bbl are expected
                to be solely sublethal due to the small area affected and their rapid dispersion. It is expected that the extent
                and severity of effects from sale-related oil spills of any size will be lessened by improved coastal oil-spill
                contingency planning (Section IV.C.5.) and by active avoidance of oil spills by cetaceans.
                    Section IV.C.1. estimates the mean number of spills less than 1,000 bbI occurring from the proposed action
                in the CPA. It is assumed that 21 spills greater than I and less than or equal to 50 bbl will occur during the
                35-year fife of the proposed action. It is estimated that the 21 spins will occur offshore and that a few Will
                contact land. It is assumed that 1 spill greater than 50 and less than 1,000 bbl will occur during the 35-year
                life of the proposed action, and it is estimated that the spin will occur offshore and that none of it will contact
                land. Although an interaction with spills less than 1,000 bbl may occur, only sublethal effects are expected.
                It is estimated that spills less than 1,000 bbl will infrequently contact and affect endangered cetaceans.
                    Section IV.C.1. estimates the mean number of spills greater than or equal to 1,000 bbl resulting from the
                proposed action in the CPA. It is assumed that one crude oil spill greater than or equal to 1,000 bbI will occur
                from either a platform or pipeline in the Central Gulf during the 35-year life of the proposed action (median
                size is 6,500 bbl). Table IV-21 identifies the estimated risk of one or more oil spills greater than or equal to
                1,000 bbI occurring and contacting, within 10 days, areas where cetaceans have been surveyed. There is a 5
                percent probability that an oil spill greater than or equal to 1,000 bbl will occur and contact within 10 days
                cetacean habitats at or beyond the shelf break of the CPA. There is a 1-2 percent probability that an oil spill
                greater than or equal to 1,000 bbl will occur and contact areas of the Mississippi Delta (survey blocks in Table
                IV-21) within 10 days where cetaceans have been sighted. Although an interaction with spills greater than or
                equal to 1,000 bbl may occur, infrequent mortalities are expected with primarily sublethal effects. It is expected
                that an off spill greater than or equal to 1,000 bbl will seldom contact and affect endangered cetaceans in the
                CPA.


                    Summary

                    Activities resulting from the proposed action have a potential to affect endangered cetaceans detrimentally.
                These cetaceans could be impacted by operational discharges, helicopter and vessel traffic, platform noise,
                explosive platform removals, seismic surveys, oil spills, and oil-spill response activities. The effects of the
                majority of these activities are expected to be sublethal. Lethal effects are expected only from oil spills greater
                than or equal to 1,000 bbl. Sale-related oil spills of any size are expected to seldom contact endangered and
                threatened cetaceans.










                  IV-214


                      Conclusion


                      The impact of the Base Case scenario on endangered and threatened cetaceans within the potentially
                  affected area is expected to result in sublethal effects that are chronic and could result in persistent
                  physiological or behavioral changes, as well as some degree of avoidance of the impacted areas.

                      High Case Ana6uis

                      The major impact-producing factors analyzed below are related to the proposed action and include
                  operational discharges, helicopter and vessel traffic, platform noise, explosive platform removals, seismic
                  surveys, off spills and off-spill response activities.
                      An estimated 7,362,000 bbl of drilling muds, 1,744,000 bbl of drill cuttings, and 660 M]Vbbl of produced
                  waters are assumed to be generated offshore as a result of the proposed action. These effluents are routinely
                  discharged into offshore marine waters and are regulated by the U.S. Environmental PrDtection Agency's
                  NPDES; permits. It is expected that endangered cetaceans will have some interaction with these discharges.
                  Direct effects to cetaceans are expected to be sublethal, and effects to cetacean food sources are not expected
                  due to the rapid offshore dilution and dispersion of operational discharges. It is expected that operational
                  discharges will seldom contact and affect endangered cetaceans.
                      It is assumed that helicopter traffic will occur on a regular basis, averaging about 31,000 trips per year.
                  The FAA Advisory Circular 91-36C encourages the use of fixed-wing aircraft above an elevation of 152 in and
                  helicopters above 300 in. It is also expected that at these elevations no cetaceans will be affected by OCS
                  helicopter traffic. It is also expected that helicopter traffic will seldom disturb and affect endangered cetaceans
                  because of special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 in.
                      It is assumed that about 880 OCS-related oil/gas service-vessel trips will occur annually as a result of the
                  proposed action and that 5 shuttle tanker trips will occur during the 35-year life of the proposed action (Table
                  IV-2). Noise from service-vessel traffic may elicit a startle reaction from cetaceans or mask their sound
                  reception. This effect is sublethal and, at worst, of a short-term, temporary nature. Cetaceans can avoid
                  service vessels, and operators can avoid cetaceans. It is expected that service-vessel traffic will seldom contact
                  and affect endangered cetaceans.
                      It is assumed that 540 exploration and delineation wells and 520 development wells will be drilled and will
                  produce sounds at intensities and frequencies that could be heard by cetaceans. It is estimated that noise from
                  drilling activities will last no longer than two months at only one location. However, the decibel level of these
                  sounds dissipates to the tolerance of most cetaceans within 15 in of the source. Odontocetes communicate at
                  higher frequencies than the dominant sounds generated by drilling platforms. Sound levels in this range are
                  not likely to be generated by drilling operations (Gales, 1982). The effects on cetaceans from platform noise
                  are expected to be sublethal. It is expected that drilling noise will seldom disturb and affect endangered
                  cetaceans.
                      Explosive platform removals can interfere with communication, disturb behavior, reduce hearing sensitivity
                  or cause hemorrhaging in cetaceans. It is estimated that 24 structures will be removed by explosives from the
                  Gulf of Mexico as a result of the proposed action. These removals are assumed to occur (luring the last 12
                  years of the life of the proposed action and no more than 8 in any single year (Table IV-2). It is expected that
                  structure removals will cause sublethal effects on cetaceans. No mortalities are expected because of the MMS
                  guidelines for explosive removals (USDOI, MMS, 1990a, Appendix B). It is expected that structure removals
                  will seldom disturb and affect endangered cetaceans.
                      Seismic surveys use airguns to generate pulses. It is assumed that only these methods will be used in
                  seismic surveys as a result of the proposed action (Section IV.A.2.). It is expected that effects on cetaceans
                  from seismic surveys are primarily sublethal, constituting short-term avoidance behavior.
                      Oil spills and off-spill response activities can adversely affect cetaceans, causing skin and eye irritation,
                  asphyxiation from inhalation of toxic fumes, food reduction or contamination, oil ingestion,and displacement
                  from preferred habitats or migration routes. In the event that oiling of cetaceans should occur from sale-
                  related oil spills greater than or equal to 1,000 bbl (1 spill of 6,500 bbl is assumed), the effects would primarily
                  be sublethal; few mortalities are expected. The effects of sale-related oil spills less than 1,000 bbl are expected










                                                                                                                             IV-215

                to be solely sublethal due to the small area affected and their rapid dispersion. It is expected that the extent
                and severity of effects from sale-related oil spills of any size will be lessened by improved coastal off-spill
                contingency planning (Section IV.C.5.) and by active avoidance of oil spills by cetaceans.
                     Section IV.C.1. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                in the CPA. It is assumed that 47 spills greater than 1 and less than or equal to 50 bbl will occur during the
                35-year life of the proposed action. It is estimated that the 47 spills will occur offshore and that few win
                contact land. It is assumed that 2 spills greater than 50 and less than 1,000 bbl will occur during the 35-year
                life of the proposed action, and it is estimated that the spill will occur offshore and that none will contact land.
                Although an interaction with spills less than 1,000 bbl may occur, only sublethal effects are expected. It is
                estimated that spills less than 1,000 bbl will seldom contact and affect endangered cetaceans.
                     Section IV.C.1. estimates the mean number of spills greater than or equal to 1,000 bbl resulting from the
                proposed action in the CPA- It is assumed that one crude oil spill greater than or equal to 1,000 bbl will occur
                from either a platform or pipeline in the Central Gulf during the 35-year life of the proposed action (median
                size is 6,500). Table IV-21 identifies the estimated risk of one or more oil spills greater than or equal to 1,000
                bbl occurring and contacting within 10 days areas where cetaceans have been surveyed. There is an 11 percent
                probability that an oil spill greater than or equal to 1,000 bbl will occur and contact, within 10 days, cetacean
                habitats at or beyond the shelf break of the CPA. There is a 14 percent probability that an oil spill greater
                than or equal to 1,000 bbl will occur and contact within 10 days areas of the Mississippi Delta where cetaceans
                have been sighted and a 1-2 percent probability of occurrence and contact within 10 days in coastal areas of
                Louisiana (Table IV-21). Although an interaction with spills greater than or equal to 1,000 bbl may occur,
                infrequent mortalities are expected with primarily sublethal effects. It is expected that an oil spill greater than
                or equal to 1,000 bbl will seldom contact and affect endangered cetaceans in the CPA.
                     Activities resulting from the proposed action have a potential to affect endangered cetaceans detrimentally.
                These cetaceans could be impacted by operational discharges, helicopter and vessel traffic, platform noise,
                explosive platform removals, seismic surveys, oil spills, and off-spill response activities. The effects of the
                majority of these activities are expected to be sublethal. Lethal effects are expected only from oil spills greater
                than or equal to 1,000 bbl. Sale-related oil spills of any size are expected to seldom contact endangered and
                threatened cetaceans.


                     Conclusion

                     The impact of the High Case scenario on endangered and threatened cetaceans within the potentially
                affected area is expected to result in sublethal effects that are chronic and may result in persistent physiological
                or behavioral changes, as well as some degree of avoidance of the impacted area(s).

                (b) Alabama, Choctawhatchee, and Perdido Key Beach Mice

                     This section discusses the effects of the proposed action on the Alabama, Choctawhatchee, and Perdido
                Key beach mice. Alabama, Choctawhatchee, and Perdido Key beach mice occupy restricted habitats behind
                coastal foredunes of Florida and Alabama. Their range is chiefly in Perdido Key State Preserve (Florida),
                Grayton Beach State Recreational Area (Florida), St Andrews State Recreation Area (Florida), Gulf Islands
                National Seashore (Alabama), and Gulf State Park (Alabama). Portions of these areas have been designated
                as critical habitat for these endangered species. The major impact-producing factors related to the proposed
                action that may effect Alabama, Choctawhatchee, and Perdido Key beach mice include off spills and oil-spill
                response activities.
                     Direct contact with spilled off can cause skin and eye irritation, asphyxiation from inhalation of toxic fumes,
                food reduction, food contamination, oil ingestion, and displacement from preferred habitat Vehicular traffic
                associated with off-spill cleanup activities can degrade preferred habitat and cause displacement from these
                areas.
                     The preferred habitat of Alabama, Choctawhatchee, and Perdido Key beach mice is not on the beach, but
                behind the barrier dunes. An oil spill would have to breach the dunes to reach either the mice or their










                 IV-216

                 preferred habitat This could occur only if an oil spill coincided with a storm surge. The home range of the
                 beach mice is within those areas, described above, that receive particular consideration during oil-spill cleanup.
                 Because of the critical designation and general status of those areas, oil-spill contingency plans include special
                 notices to minimize adverse effects from vehicular traffic during cleanup activities and to maximize the
                 protection efforts to prevent contact of these areas with spilled oil (Section MC5.).

                 Base Case Ana4wis

                     The major impact-producing factors analyzed below are related to the proposed action and include oil spills
                 and oil-spill response activities.
                     Section IV.C.1. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                 in the CPA It is assumed that fewer than 10 spills greater than 1 and less than or equal to 50 bbl Will occur
                 onshore during the 35-year life of the proposed action. It is estimated that spills less than 1,000 bblwill not
                 breach barrier dunes and contact or affect beach mice or their habitats.
                     Section IV.C.1. estimates the mean number of spills greater than or equal to 1,000 bbl resulting from the
                 proposed action in the CPA It is assumed that I crude oil spin greater than or equal to 1,000 bbl will occur
                 from either a platform or pipeline in the Central Gulf during the 35-year life of the proposed action. it is
                 expected that an oil spill greater than or equal to 1,000 bbl could breach beach barriers only if the spin
                 coincided with a storm surge strong enough to lift oil over the foredunes. Table IV-21 identifies the estimated
                 risk of one or more oil spills greater than or equal to 1,000 bbl occurring and contacting within 10 days the
                 coast near beach mice habitats. There is less than a 0.5 percent probability of an oil spill greater than or equal
                 to 1,000 bbI occurring and contacting within 10 days the coastal areas of the Alabama, Choctawhatchee, and
                 Perdido Key beach mice. It is expected that oil spills greater than or equal to 1,000 bbI will not contact or
                 affect beach mice or their habitats.
                     Vehicular traffic associated with oil-spill cleanup activities is assumed to contact beach mouse habitat in
                 the event of a spill greater than or equal to 1,000 bbl breaching barrier dunes. Table IV-21 indicates that there
                 is less than a 0.5 percent probability of an oil spill greater than or equal to 1,000 bbl occurring and contacting
                 within 10 days, the coastal areas of the Alabama, Choctawhatchee, and Perdido Key beach mice. It is expected
                 that vehicular traffic associated with oil-spill. cleanup activities will seldom contact or affect beach mice or their
                 habitats.


                 Summary

                     Activities resulting from the proposed action have a potential to affect Alabama, Choctawhatchee, and
                 Perdido Key beach mice detrimentally. Beach mice could be impacted by oil spills and oil-spill response
                 activities. It is expected that there will seldom be interaction between these events and beach mice or their
                 habitats.


                 Conclusion


                     The impact of the Base Case scenario on Alabama, Choctawhatchee, and Perdido Key beach mice within
                 the potentially affected area is expected to result in sublethal effects that seldom occur and may cause short-
                 term physiological or behavioral changes.

                 High Case Analysis

                     The major impact-producing factors analyzed below are related to the proposed action and include oil spills
                 and oil-spill cleanup activities.
                     Section IV.C. L estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                 in the CPA. It is assumed that fewer than 10 spills greater than 1 and less than or equal to 50 bbl will occur
                 onshore during the 35-year life of the proposed action. It is expected that spills less than 1,000 bbl will not
                 breach barrier dunes and contact or affect beach mice or their habitats.










                                                                                                                                  IV-217

                       Section IV.C.1. estimates the mean number of spills greater than or equal to 1,000 bbl resulting from the
                  proposed action in the CPA. It is assumed that 1 crude oil spill greater than or equal to 1,000 bbl will occur
                  from either a platform or pipeline in the Central Gulf during the 35-year life of the proposed action (median
                  size of 6,500 bbl). It is expected that an oil spill greater than or equal to 1,000 bbl could breach beach barriers
                  only if the spin coincided with a storm surge strong enough to lift oil over the foredunes. Table IV-21 identifies
                  the estimated risk of one or more oil spills greater than or equal to 1,000 bbl occurring and contacting within
                  10 days coastal areas near beach mice habitats. There is less than a 0.5 percent probability of an oil spill
                  greater than or equal to 1,000 bbl occurring and contacting within 10 days the coastal areas of the Alabama,
                  Choctawhatchee, and Perdido Key beach mice. It is estimated that oil spills greater than or equal to 1,000 bbl
                  will not contact or affect beach mice or their habitats.
                       Vehicular traffic associated with oil-spill cleanup is assumed to contact beach mouse habitat in the event
                  of a spill greater than or equal to 1,000 bbl breaching barrier dunes. Table IV-21 indicates that there is less
                  than a 0.5 percent probability of an oil spill greater than or equal 1,000 bbl occurring and contacting within 10
                  days the coastal areas of the Alabama, Choctawhatchee, and Perdido Key beach mice. It is expected that
                  vehicular traffic associated with off-spill cleanup activities will not contact or affect beach mice or their habitats.
                       Activities resulting from the proposed action have a potential to affect Alabama, Choctawhatchee, and
                  Perdido Key beach mice detrimentally. Beach mice could be impacted by oil spills and oil-spill response
                  activities. It is expected that there will be no interaction between these events and beach mice or their habitats.

                  Conclusion

                       The impact of the High Case scenario on Alabama, Choctawhatchee, and Perdido Key beach mice within
                  the potentially affected area is expected to result in sublethal effects that seldom occur and may cause short-
                  term physiological or behavioral changes.

                  (6) Imp"& on Mayine Tuitles

                       This section discusses the effect of the proposed action on the loggerhead, Kemp's ridley, hawksbill, green,
                  and leatherback marine turtles of the Gulf of Mexico. The major impact-producing factors related to the
                  proposed action are discussed in detail in Decline of the Sea 71irtles: Causes and Prevention (NRC, 1990) and
                  are described below.
                       The major impact-producing factors related to the proposed action that may affect Gulf marine turtles
                  include anchoring, structure installation, pipeline placement, dredging, operational discharges, vessel traffic,
                  explosive platform removals, OCS-related trash and debris, oil-spill response activities, and oil spins.
                       Anchoring, structure installation, pipeline placement, dredging, and operational discharges may adversely
                  affect marine turtle habitat through destruction of seagrass beds and live-bottom communities. Effects to these
                  habitats from the above mentioned impact-producing factors are described and analyzed in detail in Sections
                  IV.D.l.a.(I) and (2).
                       Noise from service-vessel traffic may elicit a startle reaction from marine turtles. This effect is sublethal,
                  and at worst, of a short-term, temporary nature (NRC, 1990). Service vessels could collide with and directly
                  impact marine turtles. Vessel-related injuries were noted in 9 percent of the marine turtles stranded in the
                  Gulf of Mexico during 1988 (USDOC, NMFS, 1989b). This observation was not able to distinguish between
                  live and dead turtles struck by boats. Marine turtles spend no more than 4 percent of their time at the surface,
                  and less time than that during the winter (Byles, 1989; Lohoefener et al., 1990).
                       Explosive platform removals can cause capillary damage, disorientation, and loss of motor control in marine
                  turtles (Duronslet et al., 1986). The effects are primarily sublethal and short-term; however, marine turtles
                  proximate to detonation would likely sustain fatal injuries. Mortalities and fatal injuries have been speculated,
                  but none has been documented. Although marine turtles occur near offshore oil and gas structures, aerial
                  surveys in the Central Gulf have shown no statistical correlation between marine turtles and offshore structures,
                  except near the Chandeleur Islands, Louisiana (Lohoefener, personal comm., 1989). To minimize the
                  likelihood of removals occurring when marine turtles may be nearby, MMS has issued guidelines for explosive










                 IV-218

                 platform removal to offshore operators. These guidelines include daylight detonation only, staggered charges,
                 placement of charges 5 m below the seafloor, and pre- and post-detonation surveys of surrounding waters.
                     Marine turtles can become entangled in monofilament fishin line, netting, 6-pack yokes, etc., which may
                                                                                     9
                 result in injury or mortality. Marine turtles are known to be attracted to floating plastic debris because of its
                 resemblance to their preferred food, the jellyfish. Ingestion of plastic and styrofoam materiats could result in
                 drowning, lacerations, digestive disorders or blockage, and reduced mobility resulting in suLrvation (Balazs,
                 1985; Carr, 1987; USDOC, NOAA, 1988d; Heileman and the Center for Environmental Education, 1988;
                 USDOI, MMS, 1989a). The MMS prohibits the disposal of equipment, containers, and other materials into
                 offshore waters by lessees (30 CFR 250.40). In addition, MARPOL, Annex V, Public Law 100-220 (101 Statute
                 1458), which prohibits the disposal of any plastics at sea or in coastal waters, went into effect January 1, 1989.
                     Off-spill response activities, such as vehicular and vessel traffic in shallow areas of seagrass beds and live-
                 bottom communities, can adversely affect sea turtle habitat and cause displacement from these preferred areas.
                 These habitats receive particular consideration during oil-spill cleanup. Because of the special. designation and
                 general status of those areas, off-spill. contingency plans include special notices to minimize adverse effects from
                 vehicular traffic during cleanup activities and to maximize the protection efforts to prevent contact of these
                 areas with spilled oil (Section IV.C.5.).
                     Oil spills can adversely affect marine turtles by toxic external contact, toxic ingestion or blockage of the
                 digestive tract, asphyxiation, entrapment in tar or off slicks, habitat destruction, and displacement from
                 preferred habitats (Fritts and McGehee, 1981; Vargo et al., 1986; Boesch and Rabal", 1987; Lutz, 1989).
                 Pelagic life stages are particularly vulnerable to contacting or ingesting oil because the currents that concentrate
                 oil spills also form the debris mats that these life stages inhabit (Vargo et al., 1986). Fritts and McGehee
                 (1982) noted that sea turtle eggs were rendered infertile on contact with oil.
                     When an oil spill occurs, many factors interact to delimit the severity of effects and the extent of damage
                 to marine turtles. Determining factors include geographic location, oil type, oil dosage, impact area,
                 oceanographic conditions, meteorological conditions, and season (NRC, 1985; USDOI, MMS, 1987b). Marine
                 turtles themselves may actively avoid an oil spill, thereby limiting the effects and lessening the extent of damage
                 to their populations. Less severe, sublethal effects are defined as those that impair the ability of an organism
                 to function effectively without causing direct mortality (NRC, 1985).

                 Base Case Ana4wis

                     The major impact-producing factors related to the proposed action that may affect Gulf marine turtles
                 include anchoring, structure installation, pipeline placement, dredging, operational discharges, OCS-related
                 trash and debris, vessel traffic, explosive platform removals, oil-spill response activities, and oil spills.
                     The impact from anchoring, structure installation, pipeline placement, dredging, and operational discharges
                 on seagrass, bed and five-bottom sea turtle habitat are analyzed in detail in Sections IV.D.La.(I) and (2).
                     To summarize the effects on wetlands and estuaries, it is expected that a dieback of up to 10-15 ha of
                 wetlands will occur for less than one growing season from contact with spilled oil. Up to 5.5 ha of wetlands
                 and estuaries could be eroded along navigation channels as a result of vessel traffic within the channels. Effects
                 to wetlands and estuaries will occur in Louisiana and along the north Texas coast. To summarize the effects
                 on seafloor habitats, little or no damage is expected to the physical integrity, species, divemity, or biological
                 productivity of topographic features or live bottoms. Small areas of 5-10 in    2 would be affected for less than
                 two years, probably on the order of four weeks. Offshore operational discharges are not lethal to marine
                 turtles and are diluted and dispersed rapidly within 1 km of the discharge point to the extent that adverse
                 effects to marine turtle food sources do not occur (API, 1989; NRC, 1983). It is expected that effects on
                 marine turtles from anchoring, structure installation, pipeline emplacement, and dredging will be
                 indistinguishable from the long-term (25-50 years) natural variability within populations of marine turtles. It
                 is expected that marine turtles will avoid 5-10 m     2 of live-bottom areas for up to a month and that this
                 avoidance of impoverished foraging areas will have no effect on marine turtles. The suspended particulate
                 matter in operational discharges offshore is expected to cause sublethal effects by inhibition of the ability of
                 marine turtles to locate their prey visually within 1 km of the discharge point for the short lime period (less
                 than one hour) spent traversing the plume.










                                                                                                                             IV-219

                    Sublethal effects on marine turtles or their habitats are expected from these impact-producing factors.
               Based on the aforementioned analyses, the estimate is that anchoring, structure installation, pipeline placement,
               dredging, and operational discharges will seldom contact and affect marine turtles or their habitats.
                    Marine turtles can become entangled in or ingest trash and debris. It is assumed that some OCS-related
               trash and debris will be accidentally lost into the Gulf and available for interaction with marine turtles.
               Although mortalities could occur, primarily sublethal effects are expected. It is expected marine turtles will
               seldom interact with OCS off- and gas-related trash and debris.
                    Explosive platform removals can cause capillary damage, disorientation, loss of motor control, and fatal
               injuries in marine turtles. It is estimated that 20 structures will be removed by explosives from the Gulf of
               Mexico as a result of the proposed action. It is assumed that these removals occur during the last 12 years of
               the life of the proposed action. No more than 5 structures will be removed in any given year. Some of the
               platform removals will occur beyond the continental shelf. As benthic feeders, Gulf of Mexico hard-shell
               marine turtles do not use habitats beyond the shelf break. Although the pelagic life stages of all marine turtles
               use these habitats, there is no correlation between marine turtles and the presence of offshore structures
               beyond the shelf break. It is expected that structure removals will cause sublethal effects on marine turtles.
               No mortalities are expected because of the MMS guidelines for explosive removals (USDOI, MMS, 1990a,
               Appendix B) and because the removals occur away from preferred offshore habitats. It is expected that
               structure removals will seldom disturb and affect marine turtles.
                    It is assumed that about 500 OCS-related oil and gas service-vessel trips will occur annually as a result of
               the proposed action and that 2 shuttle tanker trips will occur during the 35-year life of the proposed action
               (Table IV-2). Noise from service-vessel traffic may elicit a startle reaction from marine turtles. This effect is
               sublethal and, at worst, of a short-term, temporary nature. Collision between service vessels and surfaced
               marine turtles would likely cause fatal injuries. It is assumed that service-vessel traffic and marine turtles will
               seldom be in close proximity. Although a low percentage of stranded marine turtles have shown indications
               of vessel collision, it cannot be determined what types of vessel were involved and whether these injuries
               occurred before or after death. Ile OCS-related vessel traffic is a meager amount of the total vessel traffic
               in the Gulf of Mexico. Marine turtles are known to spend 4 percent or less of their time at the surface and
               to sound upon vessel approach. In addition, marine vessel operators can avoid marine turtles. It is expected
               that service-vessel traffic will seldom contact and affect marine turtles.
                    Oil spills and off-spill response activities can adversely affect marine turtles by toxic external contact, toxic
               ingestion or blockage of the digestive tract, asphyxiation, entrapment in tar or oil slicks, habitat destruction,
               and displacement from preferred habitats. Oil-spill response activities such as vehicular and vessel traffic are
               assumed to contact marine turtle habitat, such as shallow areas of seagrass beds and live-bottom communities,
               in the event of contact with an oil spill greater than or equal to 1,000 bbl. Sublethal effects are expected due
               to the particular consideration these areas receive during oil-spill cleanup to minimize adverse effects from
               traffic during cleanup activities and to maximize protection efforts to prevent contact of these areas with spilled
               oil. It is expected that oil-spill response activities will seldom contact and affect marine turtle habitat.
                    In the event that oiling of marine turtles should occur from sale-related oil spills greater than or equal to
               1,000 bbl (I spill of 6,500 is assumed) the effects would primarily be sublethal; few mortalities are expected.
               The effects of sale-related oil spills less than 1,000 bbl are expected to be solely sublethal due to the small area
               affected and their rapid dispersion. It is expected that the extent and severity of effects from sale-related oil
               spills of any size will be lessened by improved coastal oil-spill contingency planning (Section W.C.5.) and by
               active avoidance of oil spills by marine turtles.
                    Section IV.C.l. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
               in the CPA. It is assumed that 21 spills greater than I and less than or equal to 50 bbl will occur during the
               35-year life of the proposed action. It is estimated that the 21 spills will occur offshore and that a few will
               contact land. It is assumed that I spill greater than 50 and less than 1,000 bbl will occur during the 35-year
               life of the proposed action, and it is estimated that the spill will occur offshore and that none of it will contact
               land. Although an interaction with spills less than 1,000 bbl may occur, only sublethal effects are expected.
               It is expected that spills less than 1,000 bbl will seldom contact and affect marine turtles.
                    Section IV.C.l. estimates the mean number of spills greater than or equal to 1,000 bbl resulting from the
               proposed action in the CPA- It is assumed that I crude oil spill greater than or equal to 1,000 bbl will occur










                   IV-220

                   from either a platform or pipeline in the Central Gulf during the 35-year life of the proposed action (median
                   size is 6,500 bbl). Table IV-21 identifies the estimated risk of one or more oil spills greater than or equal to
                   1,000 bbl occurring and contacting within 10 days marine turtle habitat. The highest estimated probability of
                   one or more oil spills greater than or equal to 1,000 bbl occurring and contacting within 10 days marine turtle
                   habitat in the Central Gulf is I percent (Plaquemines and Terrebonne Parishes). There is a 5 percent
                   probability that one or more oil spill greater than or equal to 1,000 bbl will occur and conlact within 10 days
                   pelagic turtle habitat beyond the shelf break of the CPA. Although an interaction with spills greater than or
                   equal to 1,000 bbI may occur, infrequent mortalities are expected with primarily sublethal effects. It is expected
                   that an oil spill greater than or equal to 1,000 bbl will seldom contact and affect marine turtles in The CPA.

                   Summary

                       Activities resulting from the proposed action have a potential to affect marine turtles detrimentally. Marine
                   turtles could be impacted by anchoring, structure installation, pipeline placement, dredging, operational
                   discharges, OCS-related trash and debris, vessel traffic, explosive platform removals, oft-spill responseactivities,
                   and off spills. The effects of the majority of these activities are expected to be sublethal. Lethal effects are
                   expected only from oil spills greater than or equal to 1,000 bbl. Sale-related oil spills of an), size are expected
                   to seldom contact marine turtles.


                   Conclusion

                       The impact of the Base Case scenario on marine turtles within the potentially affected area is expected
                   to result in sublethal effects that are chronic and may cause persistent physiological or behavioral changes.

                   High Case Ana4uis

                       The major impact-producing factors related to the proposed action that may affect Gulf marine turtles
                   include anchoring,structure installation, pipeline placement, dredging, operational discharges, OCS-related trash
                   and debris, vessel traffic, explosive platform removals, ofl-spill response activities, and oil spills.
                       The impact from anchoring, structure installation, pipeline placement, dredging, and operational discharges
                   on seagrass; bed and five-bottom sea turtle habitat is analyzed in detail in Sections IV.D.La_(1) and (2).
                       To summarize the effects on wetlands and estuaries, it is expected that a dieback of up to 10-15 ha of
                   wetlands will occur for less than one growing season from contact with spilled oil. Up to 11 ha of wetlands and
                   estuaries could be eroded along navigation channels as a result of OCS-vessel traffic within the channels.
                   Effects to wetlands and estuaries will occur in Louisiana and along the north Texas coast. To summarize the
                   effects on seafloor habitats, little or no damage is expected to the physical integrity, species, diversity, or
                   biological productivity of topographic features or live bottoms. Small areas of 5-10 m2 would be affected for
                   less than two years, probably on the order of four weeks.
                       Offshore operational discharges are not lethal to marine turtles and are diluted and dispersed rapidly within
                   1 kni of the discharge point to the extent that adverse effects to marine turtle food sources do not occur (API,
                   1989; NRC, 1983). It is expected that effects on marine turtles from anchoring, structure installation, pipeline
                   emplacement, and dredging will be indistinguishable from the long-term (25-50 years) natural variability within
                   populations of marine turtles. It is expected that marine turtles will avoid 5-10   M2 of five-bottom areas for up
                   to a month and that this avoidance of impoverished foraging areas will have no effect on marine turtles. The
                   suspended particulate matter in operational discharges offshore are expected to cause sublethal effects by
                   inhibition of the ability of marine turtles to locate their prey visually within 1 kin of the discharge point for the
                   short time period (less than one hour) spent traversing the plume.
                       Sublethal effects on marine turtles or their habitats are expected from these impact-producing factors.
                   Based on the aforementioned analyses, the estimate is that anchoring, structure installation, pipeline placement,
                   dredging, and operational discharges will seldom contact and affect marine turtles or their habitats.
                       Marine turtles can become entangled in or ingest trash and debris. It is assumed that some OCS-related
                   trash and debris will be accidentally lost into the Gulf and available for interaction with marine turtles.










                                                                                                                             IV-221

               Although mortalities could occur, primarily sublethal effects are expected. It is expected that marine turtles
               will seldom interact with OCS off- and gas-related trash and debris.
                    Explosive platform removals can cause capillary damage, disorientation, loss of motor control, and fatal
               injuries in marine turtles. It is estimated that 24 structures will be removed using explosives from the Gulf of
               Mexico as a result of the proposed action. It is assumed that these removals occur during the last 12 years of
               the life of the proposed action, no more than 8 in any single year, and that some of the platform removals win
               occur in habitats beyond the continental shelf. As benthic feeders, Gulf of Mexico hard-shell marine turtles
               do not use habitats beyond the shelf break. Although the pelagic life stages of all marine turtles use these
               habitats, there is no correlation between marine turtles and the presence of offshore structures beyond the shelf
               break. It is expected that structure removals will cause sublethal effects on marine turtles. No mortalities are
               expected because of the MMS guidelines for explosive removals (USDOI, MMS, 1990a, Appendix B) and
               because the removals occur away from preferred offshore habitat. It is expected that structure removals will
               seldom disturb and affect marine turtles.
                    It is assumed that about 880 OCS-related oil and gas service-vessel trips will occur annually as a result of
               the proposed action and that 5 shuttle tanker trips will occur during the 35-year life of the proposed action
               (Table IV-2). Noise from service-vessel traffic may elicit a startle reaction from marine turtles. This effect is
               sublethal and, at worst, of a short-term, temporary nature. Collision between service vessels and surfaced
               marine turtles would likely cause fatal injuries. It is expected that service-vessel traffic and marine turtles win
               seldom be in close proximity. Although a low percentage of stranded marine turtles have shown indications
               of vessel collision, it cannot be determined what types of vessel were involved and whether these injuries
               occurred before or after death. Marine turtles are known to spend 4 percent or less of their time at the
               surface and to sound upon vessel approach. In addition, marine vessel operators can avoid marine turtles.
               It is expected that service-vessel traffic will seldom contact and affect marine turtles.
                    Oil spills and off-spill response activities can adversely affect marine turtles by toxic external contact, toxic
               ingestion or blockage of the digestive tract, asphyxiation, entrapment in tar or oil slicks, habitat destruction,
               and displacement from preferred habitats. Off-spill response activities such as vehicular and vessel traffic are
               assumed to contact marine turtle habitat, such as shallow areas of seagrass beds and five-bottom communities,
               in the event of contact with an off spill greater than or equal to 1,000 bbl. Sublethal effects are expected due
               to the particular consideration these areas receive during off-spill. cleanup to minimize adverse effects from
               traffic during cleanup activities and to maximize protection efforts to prevent contact of these areas with spilled
               oil. It is expected that off-spill response activities will seldom contact and affect marine turtle habitat.
                    In the event that oiling of marine turtles should occur from sale-related oil spills greater than or equal to
               1,000 bbl (1 spill of 6,500 bbl is assumed), the effects would primarily be sublethal; few mortalities are
               expected. The effects of sale-related oil spills less than 1,000 bbl are expected to be solely sublethal due to
               the small area affected and their rapid dispersion. It is expected that the extent and severity of effects from
               sale-related oil spills of any size will be lessened by improved coastal oil-spill contingency planning (Section
               IV.C.5.) and by active avoidance of oil spills by marine turtles.
                    Section IV.C.l. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
               in the CPA. It is assumed that 47 spills greater than 1 and less than or equal to 50 bbl will occur during the
               35-year life of the proposed action. It is estimated that the 47 spills will occur offshore and that few will
               contact land. It is assumed that 2 spills greater than 50 and less than 1,000 bbl will occur during the 35-year
               life of the proposed action, and it is estimated that the spills will occur offshore and that none will contact land.
               Although an interaction with spills less than 1,000 bbl may occur, only sublethal effects are expected. It is
               expected that spills less than 1,000 bbl will seldom contact and affect marine turtles.
                    Section IV.C.1. estimates the mean number of spills greater than or equal to 1,000 bbl resulting from the
               proposed action in the CPA. It is assumed that 1 crude oil spill greater than or equal to 1,000 bbl will occur
               from either a platform or pipeline in the Central Gulf during the 35-year life of the proposed action (median
               size is 6,500 bbl). Table IV-21 identifies the estimated risk of one or more oil spills greater than or equal to
               1,000 bbl occurring and contacting within 10 days marine turtle habitat. The highest estimated probability of
               one or more oil spills greater than or equal to 1,000 bbl occurring and contacting within 10 days marine turtle
               habitat in the Central Gulf is 1 percent (Plaquemines and Terrebonne Parishes). There is an 11 percent
               estimated probability that an oil spill greater than or equal to 1,000 bbl will occur and contact within 10 days










                   IV-222

                   pelagic turtle habitat beyond the shelf break of the CPA- Although an interaction with spills greater than or
                   equal to 1,000 bbl may occur, infrequent mortalities are expected with primarily sublethal effects. It is expected
                   that an oil spill greater than or equal to 1,000 bbl will seldom contact and affect marine turtles in the CPA.
                       Activities resulting from the proposed action have a potential to affect marine turtles detrimentally. Marine
                   turtles could be impacted by anchoring, structure installation, pipeline placement, dredging, and operational
                   discharges, OCS-related trash and debris, vessel traffic, explosive platform removals, off-spiTresponse -activities,
                   and oil spills. The effects of the majority of these activities are expected to be sublethal. Lethal effects are
                   expected only from off spills greater than or equal to 1,000 bbl. Sale-related oil spills of any size are expected
                   to seldom contact marine turtles.


                   Conclusion


                       The impact of the High Case scenario on marine turtles within the potentially affected area is expected
                   to result sublethal effects that are chronic and may cause persistent physiological or behavioral changes.

                   (7) Impacts on Coastal and Marine Birth

                       Effects on coastal and marine birds from activities associated with the proposed action could come from
                   oil spills, disturbance from OCS service-vessel and helicopter traffic near coastal areas, displacement from
                   onshore pipeline landfalls and facility construction near coastal areas, and entanglement and ingestion of
                   offshore off- and gas-related plastic debris. Potential effects from these impact-producing factors are described
                   below.
                       Sections providing supportive material for the coastal and marine bird analysis include Sections III.B.5.
                   (description of coastal and marine birds), IV.C.1. and IV.C.3. (oil spills), IV.A.2.c. (support activities),
                   IV.A.3.a.(l) (service and construction facilities), and IV.A-2.d.(5) (loss of trash and debris).
                       When an oil spill occurs, many factors interact to delimit the severity of effects and the extent of damage
                   to coastal and marine bird populations. The direct effect of oiling on birds occurs through the matting of
                   feathers and subsequentloss of body insulationand water-repellency, the ingestion of oil, the depression of egg-
                   laying activity, and the reduction of hatching success (Holmes and Cronshaw, 1977; Ainley et al., 1981; Peakall
                   et al., 1981). Transfer of oil from adults to eggs and young during nesting results in significant mortality for
                   new eggs and deformities in hatchlings from eggs further along in incubation (Clapp et al., 1982a). Stress from
                   ingested oil can be additive to ordinary environmental stresses such as low winter temperatures, migration, or
                   molting (Holmes, 1984). Direct contact by birds with appreciable amounts of oil is usually J'atal (NRC, 1985).
                       The impacts from spills less than 1,000 bbl differ in severity and kind from those of spills greater than or
                   equal to 1,000 bbl. An OCS-related spill greater than or equal to 1,000 bbl certainly can be a long-term
                   catastrophic event; however, if the frequency of such an event is low, the spill will eventually disappear due to
                   physical-chemical processes and complex degradation (NRC, 1985). On a much smaller scale, spills less than
                   1,000 bbl may not have the same immediate effect that a spill greater than or equal to 1,000 bbl has on
                   seabirds, but if the frequency of sublethal effects is relatively high, spills less than 1,000 b'bl may be a more
                   serious problem causing continued irritation and/or sublethal toxic effects. Less severe, sublethal effects are
                   defined as those that impair the ability of an organism to function effectively without causing direct mortality
                   (NRC, 1985).
                       Those birds most susceptible to oiling either raft at sea or congregate in large numbers--gulls, terns, white
                   pelicans, and certain waterfowl such as scaup--or dive to feed, such as cormorants and anhinga. Because of
                   the strong visual impact, the death of coastal and marine birds from oiling due to an OCS-re)[ated spill receives
                   a large amount of publicity (Clapp et al., 1982a; NRC, 1985). Although mortality among marine birds may
                   appear high as the result of an oil spill greater than or equal to 1,000 bbl, there is no eviden(x at this time that
                   this mortality has adversely affected any species on a population level on the United States OCS (NRC, 1985).
                       Rehabilitation of oiled birds and deterrence away from the immediate area of an oil spill are procedures
                   proven to limit the severity of the effect and lessen the extent of damage to populations of coastal and marine
                   birds. More than 95 percent of the oil type found on the OCS in the Gulf of Mexico, South Louisiana Crude,










                                                                                                                               IV-223

                  dissipates quickly, is easy to saponify, and is not as highly toxic to birds as more refined offs (Section IV.C.2.).
                  Survival of rehabilitated oiled birds varies from 30 percent (Sims, 1970) to 90 percent (Mueller and Mendoza,
                  1983). The success of rehabilitation is primarily due to three factors: advance preparation in the stockpiling
                  of supplies and training of volunteers; the availability of a cleanup station with adequate indoor space, hot
                  running water, and outdoor pens; and, most importantly, the efforts and cooperation of willing volunteers and
                  the government agencies involved (Mueller and Mendoza, 1983). Refer to Section IV.C.5. for further
                  information on off-spill response options and rehabilitation of oiled coastal and marine birds in the Gulf of
                  Mexico.
                      Supplies, services, and personnel are transported by service vessels and helicopters to OCS oil and gas
                  structures. Disturbance created from OCS-related service-vessel traffic could affect coastal and marine birds
                  in coastal feeding, resting, or breeding/nesting habitats. Disturbance can result in reduced use or desertion of
                  the affected habitats by coastal and marine birds (USDOI, MMS, 1985a). Similarly, OCS-related helicopter
                  traffic could disturb feeding, resting, breeding or nesting behavior of birds, or cause abandonment of preferred
                  habitat Disturbance by either service-vessel or helicopter traffic could contribute to population declines by
                  relocation of birds to areas where they may experience increased environmental or physiological stress.
                      Pipeline landfalls and coastal construction can displace coastal and marine birds from coastal feeding,
                  roosting, or nesting habitats (Wicker and Rabalais, 1988). The dredging of pipeline channels across coastal
                  habitats can alter coastal processes and create zones of weakness that can result in accelerated erosion and
                  landscape changes in the vicinity of the landfall. The actual dredging can displace coastal and marine birds,
                  and the resultant habitat may be so changed that it is no longer suitable as feeding, resting, or nesting habitat.
                  Coastal construction may require dredging or filling of coastal habitats to create the necessary foundation for
                  facilities that will service OCS oil and gas activities. The altered habitat, plus some small amount of
                  surrounding area, will no longer be suitable as feeding, resting, or nesting habitat for coastal and marine birds.
                  Displacement could contribute to population declines by relocation of birds to areas where they may experience
                  increased environmental or physiological stress.
                      Coastal and marine birds can become entangled in monofflament fishing line, netting, 6-pack yokes, etc.,
                  which may result in injury or mortality. Ingestion of plastic and styrofoam materials may cause internal
                  blockage, resulting in injury or mortality (Centaur Associates, Inc. and Center for Environmental Education,
                  1986). Ingested plastic may impair feeding activity where plastic reduces the food storage volume of the
                  stomach and limits the accumulation of fat reserves essential for reproduction and migration (Ryan, 1988).
                  The MMS prohibits the disposal of equipment, containers, and other materials into offshore waters by lessees
                  (30 CFR 250.40). In addition, MARPOL, Annex V, Public Law 100-220 (101 Statute 1458), which prohibits
                  the disposal of any plastics at sea or in coastal waters, went into effect January 1, 1989.
                  (a) Nonendangered and Nonthreatened Species

                  Base Case Ana4uis

                      The Gulf of Mexico is populated by migrant and nonmigrant species of coastal and marine birds. This
                  broad category consists of four main groups: seabirds, waterfowl, wading birds, and shorebirds. The major
                  impact-producing factors analyzed below are related to the proposed action and include oil spills, OCS
                  helicopter and service-vessel traffic, pipeline landfalls and coastal facility construction, and oil- and gas-related
                  plastic debris.
                      In the event that oiling of coastal and marine birds should occur from sale-related spills, the effect of any
                  oiling is expected to be lessened due to the nature of Southern Louisiana crude: directly, by its chemical
                  composition and traits; and indirectly, by an increase in the percentage of survival from rehabilitation efforts.
                  The effect of spilled oil on coastal and marine birds is expected to result in a partial, short-term decrease in
                  a local population within the vicinity of spilled oil.
                      In the event that sale-related off spills should occur in critical feeding habitats of coastal and marine birds,
                  sublethal and some lethal effects are expected. Sublethal effects are expected to be lessened by deterrence
                  of birds away from the oiled area and improved coastal oil-spill contingency planning and response (Section










                 IV-224

                 IV.C.5.). Sublethal effects of spilled oil reaching critical feeding habitats are expected to result in a partial,
                 short-term decrease in a local population within the vicinity of the affected feeding habitats.
                     Section IV.C.1. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                 in the CPA- It is assumed that 21 offshore spills and fewer than 10 onshore spills greater than 1 and less than
                 or equal to 50 bbl will occur during the 35-year life of the proposed action. Few of the totalspills will contact
                 the coastline. It is assumed that I spill greater than 50 and less than 1,000 bbl will occur during the 35-year
                 life of the proposed action and that it will not contact the coastline. For the purpose of this analysis, it is
                 assumed that spills less than 1,000 bbl will seldom contact and affect feeding, resting, or nesting habitats. The
                 effect from spills less than 1,000 bbl on Gulf coastal and marine birds is expected to be negligible.
                     Section IV.C.1. estimates the mean number of oil spills greater than or equal to 1,000 bbl resulting from
                 the proposed action in the CPA- It is assumed that one crude oil spill greater than or equal to 1,000 bbl will
                 occur from either a platform or pipeline in the Central Gulf during the 35-year life of the proposed action
                 (median size is 6,500 bbl). Table IV-21 identifies the estimated risk of one or more oil spilN greater than or
                 equal to 1,000 bbl occurring and contacting within 10 days feeding, resting, or nesting habitats of coastal and
                 marine birds in the CPA. The highest probability of one or more oil spills greater than or equal to 1,000 bbl
                 greater than 1,000 bbl occurring and contacting within 10 days a coastal bay in the Central Gulf is 1 percent
                 (Timbalier Bay). The highest estimated probability of one or more spills greater than or equal to 1,000 bbl
                 occurring and contacting within 10 days deltaic marshes is 1 percent. For the purpose of this analysis, it is
                 assumed that an oil spill greater than or equal to 1,000 bbl will seldom contact and affect the feeding, resting,
                 or nesting habitats in the CPA- The effect from an off spill greater than or equal to 1,000 bbl on Gulf coastal
                 and marine birds is expected to be negligible.
                     The majority of coastal and marine bird feeding habitats occur nearshore. The highest estimated
                 probability of one or more spills greater than or equal to 1,000 bbl occurring and contacting within 10 days
                 nearshore areas and coastline along the Central Gulf is 2 percent. For the purpose of this analysis, it is
                 estimated that an oil spill greater than or equal to 1,000 bbl will seldom contact and affect nearshore areas and
                 coastline critical to the feeding of coastal and marine birds in the CPA. The effect on Gulf coastal and marine
                 birds is expected to be negligible.
                     It is assumed that no spills greater than equal to 1,000 bbl originating from OCS tankering, will occur and
                 contact within 10 days a Central Gulf bay, estuary, or nearshore area. For the purpose of this analysis, it is
                 assumed that an oil spill greater than or equal to 1,000 bbl and originating from OCS-related tankering will
                 not interact with Gulf coastal and marine birds.
                     Helicopter and service-vessel traffic related to OCS activities could disturb feeding, resting, or nesting
                 behavior of birds or cause abandonment of preferred habitat. This impact-producing factor could contribute
                 to population losses by displacement of birds to areas where they may experience increased environmental or
                 physiological stress.
                     The FAA Advisory Circular 91-36C prohibits the use of fixed-wing aircraft lower than an elevation. of 152
                 in and helicopters lower than 300 in during the period of October 15 through April 15 in the vicinity of
                 numerous national wildlife refuges along the Gulf Coast in order to prevent disturbances to the birds
                 (Biological Opinion Section 7 Consultation, Proposed Exploration Plans for OCS in the Gulf of Mexico;
                 FWS/OES 375.0). The majority of these wildlife refuges provide important feeding, resting, and nesting areas
                 for coastal and marine birds. Although an incident may occur and be disruptive, the effect is, at worst, of a
                 temporary nature. It is assumed that helicopter traffic will not disturb Gulf coastal and marine birds because
                 of special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 in. For the
                 purpose of this analysis, it is assumed that OCS-related flights at the appropriate altitude will seldom disturb
                 Gulf coastal and marine birds. The effect of OCS-related flights on Gulf coastal and marine birds is expected
                 to be negligible.
                     It is assumed that about 500 OCS-related oil and gas service-vessel trips will occur annually as a result of
                 the proposed action and that 2 shuttle tanker trips will occur during the 35-year life of the proposed action
                 (Table IV-2). For the purpose of this analysis, it is assumed that service-vessel traffic will seldom disturb Gulf
                 coastal and marine birds. The effect of service-vessel traffic on Gulf coastal and marine birds will be negligible.
                     Disturbance of coastal and marine bird nesting and feeding habitats from pipeline landfalls and onshore
                 construction could result in a reduction of or desertion by birds that use the habitats. It is assumed that no










                                                                                                                               IV-225

                 new OCS off- and gas-related pipeline landfalls or coastal facilities will be constructed as a result of the
                 proposed action in the CPA- For the purpose of this analysis, it is estimated that pipeline landfalls and onshore
                 construction will not interact with feeding, resting, or nesting habitats of Gulf coastal and marine birds.
                      Coastal and marine birds can become entangled in or ingest trash and debris. Interaction with plastic
                 materials can be especially injurious and cause mortalities. It is expected that coastal and marine birds will
                 seldom become entangled in or ingest OCS-related trash and debris. The MMS prohibits the disposal of
                 equipment, containers, and other materials into offshore waters by lessees (30 CFR 250.40). In addition,
                 MARPOL, Annex V, Public Law 100-220 (101 Statute 1458), which prohibits the disposal of any plastics at sea
                 or in coastal waters, went into effect January 1, 1989. For the purpose of this analysis, it is assumed that OCS
                 oil- and gas-related plastic debris will seldom interact with Gulf coastal and marine birds, and therefore, the
                 effect will be negligible.

                 Summary

                      Activities resulting from the proposed action have the potential to affect Central Gulf coastal and marine
                 birds detrimentally. It is expected that the effects from the major impact-producing factors on coastal and
                 marine birds are negligible and of nominal occurrence. As a result, there will no discernible disturbance to
                 Gulf coastal and marine birds.


                 Conclusion

                      The impact of the Base Case scenario on nonendangered and nonthreatened coastal and marine birds
                 within the potentially affected area is expected to result in no discernible decline in a population or species and
                 no change in distribution and/or abundance on a local or regional scale. Individuals experiencing sublethal
                 effects will recover to predisturbance condition in less than one generation.

                 High Case Analysis

                      The major impact-producing factors analyzed below are related to the proposed action and include oil
                 spills, OCS helicopter and service-vessel traffic, pipeline landfalls and coastal facility construction, and oil- and
                 gas-related plastic debris.
                      In the event that oiling of coastal and marine birds should occur from sale-related spills, the effect of any
                 oiling is expected to be lessened due to the nature of Southern Louisiana Crude: directly, by its chemical
                 composition and traits; and indirectly, by an increase in the percentage of survival from rehabilitation efforts.
                 The effect of spilled oil on coastal and marine birds is expected to result in a partial, short-term decrease in
                 a local population within the vicinity of spilled oil.
                      In the event that sale-related oil spills should occur in critical feeding habitats of coastal and marine birds,
                 sublethal effects are expected. These are expected to be lessened by deterrence of birds away from the offed
                 area and improved coastal oil-spill contingency planning and response (Section IV.C.5.). Sublethal effects of
                 spilled oil within critical feeding habitats of coastal and marine birds are expected to result in a partial, short-
                 term decrease in a local population within the vicinity of the affected feeding habitats.
                      Section IV.C.1. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                 in the CPA. It is assumed that 47 offshore spills and fewer than 10 onshore spills greater than 1 and less than
                 or equal to 50 bbl will occur during the 35-year fife of the proposed action. Few of the offshore spins will
                 contact the coastline. It is assumed that 2 spills greater than 50 and less than 1,000 bbl will occur during the
                 35-year life of the proposed action and that they will not contact the coastline. For the purpose of this analysis,
                 it is assumed that spills less than 1,000 bbl will seldom contact and affect feeding, resting, or nesting habitats.
                 The effect on Gulf coastal and marine birds is expected to be negligible.
                      Section IV.C.1. estimates the mean number of oil spills greater than or equal to 1,000 bbl resulting from
                 the proposed action in the CPA- It is assumed that one crude oil spin greater than or equal to 1,000 bbl win
                 occur from either a platform or pipeline in the Central Gulf during the 35-year life of the proposed action
                 (median size is 6,500 bbl). Table IV-21 identifies the estimated risk of one or more oil spills greater than or










                 IV-226

                 equal to 1,000 bbl occurring and contacting within 10 days feeding, resting, or nesting habitats within 10 days.
                 The highest probability of one or more oil spills greater than or equal to 1,000 bbl occurring and contacting
                 within 10 days a coastal bay in the Central Gulf is 2 percent (Timbalier Bay). The highest estimated probability
                 of one or more spills greater than or equal to 1,000 bbl occurring and contacting within 10 days deltaic marshes
                 is 2 percent. For the purpose of this analysis, it is assumed that an oil spill greater than 1,000 bbl win seldom
                 contact and affect the feeding, resting, or nesting habitats in the CPA. The effect from oil spills greater than
                 or equal to 1,000 bbl on Gulf coastal and marine birds is expected to be negligible.
                     The majority of coastal and marine bird feeding habitats occur nearshore. The highest estimated
                 probability of one or more spills greater than or equal to 1,000 bbl occurring and contacting within 10 days
                 nearshore areas (coastline) along the Central Gulf is 4 percent. For the purpose of this analysis, it is estimated
                 that an off spill greater than or equal to 1,000 bbl will seldom contact and affect nearshore areas (coastline)
                 critical to the feeding of coastal and marine birds in the CPA. The effect on Gulf coastal and marine birds
                 is expected to be negligible.
                     It is assumed that no spills greater than or equal to 1,000 bbl originating from OCS tankering will occur
                 and contact within 10 days a Central Gulf bay, estuary, or nearshore area. For the purpose of this analysis,
                 it is estimated that an oil spill from OCS tankering will not interact with Gulf coastal and marine birds.
                     Helicopter and service-vessel traffic related to OCS activities could disturb feeding, resting, or nesting
                 behavior of birds or cause abandonment of preferred habitat. This impact-producing factor could contribute
                 to population losses by displacement of birds to areas where they may experience increased environmental or
                 physiological stress.
                     The FAA Advisory Circular 91-36C prohibits the use of fixed-wing aircraft lower than an. elevation of 152
                 in and helicopters lower than 300 in during the period of October 15 through April 15 in the vicinity of
                 numerous national wildlife refuges along the Gulf Coast to prevent disturbances to the birds (Biological
                 Opinion Section 7 Consultation, Proposed Exploration Plans for OCS in the Gulf of Mexico; F`WS/OES 375.0).
                 The majority of these wildlife refuges provide important feeding, resting, and nesting areas for coastal and
                 marine birds. Although an incident may occur and be disruptive, the effect is, at worst, of a temporary nature.
                 It is assumed that helicopter traffic will not disturb Gulf coastal and marine birds because of special
                 prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 in. For the purpose
                 of this analysis, it is assumed that OCS-related flights at the appropriate altitude will seldom disturb Gulf
                 coastal and marine birds. The effect on Gulf coastal and marine birds is expected to be neg ible.
                                                                                                                 Ilig
                     It is assumed that about 880 OCS-related oil and gas service-vessel trips will occur annually as a result of
                 the proposed action and that 5 shuttle tanker trips will occur during the 35-year life of the proposed action
                 (Table IV-2). For the purpose of this analysis, it is assumed that service-vessel traffic will seldom disturb Gulf
                 coastal and marine birds. The effect on Gulf coastal and marine birds is expected to be negligible.
                     Disturbance of coastal and marine bird nesting and feeding habitats from pipeline landfalls and onshore
                 construction could result in a reduction of or desertion by birds that use the habitats. It is assumed that no
                 new OCS oil- and gas-related pipeline landfalls and one pipeyard will be constructed as a result of the
                 proposed action in the CPA- For the purpose of this analysis, it is estimated that pipeline landfalls and onshore
                 construction will not interact with feeding, resting, or nesting habitats of Gulf coastal and marine birds.
                     Coastal and marine birds can become entangled in or ingest trash and debris. Interaction with plastic
                 materials can be especially injurious and cause mortalities. It is assumed that coastal and marine birds will
                 seldom become entangled in or ingest OCS-related trash and debris. The MMS prohibits the disposal of
                 equipment, containers, and other materials into offshore waters by lessees (30 CFR 250.40). In addition,
                 MARPOI, Annex V, Public Law 100-220 (101 Statute 1458), which prohibits the disposal of any plastics at sea
                 or in coastal waters, went into effect January 1, 1989. For the purpose of this analysis, it is assumed that OCS
                 off- and gas-related plastic debris will seldom interact with seabirds. The effect on Gulf coastal and marine
                 birds is expected to be negligible.
                     Activities resulting from the proposed action have the potential to affect Central Gulf coastal and marine
                 birds detrimentally. It is expected that the effects from the major impact-producing factors on coastal and
                 marine birds are negligible and of nominal occurrence. As a result, there will no discernible disturbance to
                 Gulf coastal and marine birds.










                                                                                                                              IV-227


               Conclusion

                    The impact of the High Case scenario on coastal and marine birds within the potentially affected area is
               expected to result in no discernible decline in a population or species and no change in distribution and/or
               abundance on a local or regional scale. Individuals experiencing sublethal effects will recover to predisturbance
               condition in less than one generation.

               (b) Endangered and Threatened Species

                    This section discusses the effects of the proposed action on endangered and threatened birds, including
               the brown pelican, Arctic peregrine falcon, bald eagle, and piping plover. It summarizes and incorporates the
               discussion of the effects on the coastal and marine birds in Section IV.D.La.(7)(a) (nonendangered and
               nonthreatened birds) and additional information as cited. Oil spills, OCS service-vessel and helicopter traffic,
               onshore pipeline construction, and entanglement and ingestion of offshore oil- and gas-related plastic debris
               are sources of potential adverse impacts. The effects on birds from these impact-producing factors are
               discussed under nonendangered and nonthreatened birds (Section IV.D.La.(7)(a)). Any activity that is a result
               of the proposed action and that results in the mortality of an endangered or threatened bird represents a
               substantial impact on the species under discussion as above.

               Base Case Ana4uis

                    It is assumed that helicopter traffic will occur on a regular basis, averaging 18,000 trips per year. The FAA
               Advisory Circular 91-36C prohibits the use of fixed-wing aircraft lower than an elevation of 152 m and
               helicopters lower than 300 in during the period of October 15 through April 15 in the vicinity of numerous
               national wildlife refuges in the Gulf of Mexico to prevent disturbances to the birds (Biological Opinion - Section
               7 Consultation, Proposed Exploration Plans for OCS in the Gulf of Mexico; FWS/OES 375.0). The majority
               of these wildlife refuges provide important critical habitats (feeding, resting, or nesting areas) for endangered
               and threatened species. Although interactions may occur and be disruptive, effects are expected to be sublethal
               and, at worst, of a temporary nature. It is expected that helicopter traffic near critical feeding, resting, or
               nesting areas will seldom disturb the brown pelican, Arctic peregrine falcon, bald eagle, or piping plover
               because of special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 in.
                    It is assumed that about 500 OCS-related oil and gas service-vessel trips will occur annually as a result of
               the proposed action and that 2 shuttle tanker trips will occur during the 35-year life of the proposed action
               (Table IV-2). Most of the OCS-related oil and gas traffic occurs in and out of areas that are well away from
               critical habitats for feeding, resting, or nesting areas of the Arctic peregrine falcon, bald eagle, or piping plover.
               Some OCS-related service vessel traffic occurs in the vicinity of Cameron, Intracoastal City, Morgan City, and
               Venice, Louisiana, within several miles of critical feeding, resting, or nesting habitats for the brown pelican
               (Table IV-15). Although incidents may occur and be disruptive, effects are expected to be sublethal and, at
               worst, of a temporary nature. It is expected that service-vessel traffic will seldom disturb the brown pelican.
                    Disturbance of brown pelican and piping plover critical feeding, resting, or nesting habitats from pipeline
               landfalls and onshore construction could result in a reduction or desertion of birds that use the habitats. It is
               assumed that no new OCS oil- and gas-related pipeline landfalls or coastal facilities will be constructed as a
               result of the Proposed action in the CPA (Section IV.A-3.b.). It is estimated that pipeline landfalls and onshore
               construction will not interact with critical feeding, resting, or nesting habitats of the brown pelican, Arctic
               peregrine falcon, or piping plover.
                    The brown pelican, Arctic peregrine falcon, bald eagle, and piping plover can become entangled in or
               ingest trash and debris. Interaction with plastic materials can be especially injurious. The MMS prohibits the
               disposal of equipment, containers, and other materials into offshore waters by lessees (30 CFR 250.40). In
               addition, NtkRPOL, Ann" V, Public Law 100-220 (101 Statute 1458), which prohibits the disposal of any
               plastics at sea or in coastal waters, went into effect January 1, 1989. It is assumed that very little trash and
               debris will be lost into the Gulf of Mexico as a result of the proposed action. Although interactions may occur,










                   IV-228

                   effects are expected to be sublethal. It is expected that the brown pelican, Arctic peregrine falcon, bald eagle,
                   and piping plover will seldom become entangled in or ingest OCS-related trash and debris,.
                       When an off spill occurs, many factors interact to influence the severity of effects and the extent of damage
                   to endangered and threatened birds. Important factors include geographic location, oil t3pe, amount of oil,
                   impact area, oceanographic conditions, meteorological conditions, and season (NRC, 1985; USDOI, MMS,
                   1987b). The direct effect of oiling on birds occurs through the matting of feathers and subsequent loss of body
                   insulation and water-repellency, the ingestion of oil, the depression of egg-laying activity, and the reduction of
                   hatching success (Holmes and Cronshaw, 1977; Ainley et al., 1981; Peakall et al., 1981). Transfer of off from
                   adults to eggs and young during nesting results in significant mortality for new eggs and deformities in
                   hatchlings from eggs further along in incubation (Clapp et al., 1982a). Indirect effects of oil spills include
                   contamination, displacement, and reduction of food sources. Food contamination may cause less severe,
                   sublethal effects decreasing survival and fecundity, affecting behavior, and decreasing survival of young. Less
                   severe, sublethal effects are defined as those that impair the ability of an organism to function effectively
                   without causing direct mortality (NRC, 1985).
                       In the event that oiling of the brown pelican, Arctic peregrine falcon, bald eagle, or piping plover should
                   occur from sale-related oil spills greater than or equal to 1,000 bbl (1 spill of 6,500 bbl is assumed), the effects
                   would primarily be sublethal; few mortalities are expected. The effects of sale-related oil spills less than 1,000
                   bbl are expected to be solely sublethal due to the small area affected. In the event that sale-related oil spills
                   of any size should occur in critical habitats for feeding, resting, or nesting, such as inshore, intertidal, and
                   nearshore areas, sublethal effects are expected. It is expected that the extent and severity of effects from sale-
                   related oil spills of any size will be lessened by improved coastal oil-spill contingency planning and response,
                   deterrence of birds away from the immediate area of an oil spill, and increased percentage of survival from
                   rehabilitation efforts (Section IV.C.5.).
                       Section W.C.I. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                   in the CPA. It is assumed that 21 offshore spills and fewer than 10 onshore spills greater than 1 and less than
                   or equal to 50 bbl will occur during the 35-year life of the proposed action. Few of the offshore spills will
                   contact the coastline. It is assumed that I offshore spill greater than 50 and less than 1,000 bb] win occur
                   during the 35-year life of the proposed action, and it is estimated that the spill will not contact the coastline.
                   Although an interaction with spills less than 1,000 bbl may occur, only sublethal effects are expected. It is
                   estimated that small spills less than 1,000 bbl will seldom contact and affect the brown pelican, Arctic peregrine
                   falcon, bald eagle, and piping plover.
                       Section W.C.I. estimates the mean number of spills greater than or equal to 1,000 bbl resulting from the
                   proposed action in the CPA. It is assumed that one crude oil spill greater than or equal to 1,000 bbl win occur
                   from either a platform or pipeline in the Central Gulf during the 35-year life of the proposed action (median
                   size is 6,500 bbl). Table IV-21 identifies the estimated risk of one or more oil spills greater than or equal to
                   1,000 bbl occurring and contacting within 10 days critical habitats for feeding, resting, or nesting of the brown
                   pelican, Arctic peregrine falcon, bald eagle, and piping plover in the CPA- The highest probability of one or
                   more oil spills greater than or equal to 1,000 bbl occurring and contacting within 10 days a coastal bay in the
                   Central Gulf is 1 percent (Timbalier Bay). The highest estimated probability of one or more spills, greater than
                   or equal to 1,000 bbl occurring and contacting within 10 days deltaic marshes is 1 pero-.nt. Although an
                   interaction with spills greater than or equal to 1,000 bbl may occur, infrequent mortalities are expected with
                   primarily sublethal effects. It is expected that an oil spill greater than or equal to 1,000 bbl will seldom contact
                   and affect the brown pelican, Arctic peregrine falcon, bald eagle, and piping plover in the CPA.
                       Some critical feeding habitats of the brown pelican, Arctic peregrine falcon, and piping plover occur
                   nearshore. The highest estimated probability of one or more spills greater than or equal to 1,000 bbl occurring
                   and contacting within 10 days nearshore areas (coastline) along the Central Gulf is 2 percent. Although an
                   incident may occur, sublethal effects are expected. It is estimated that an oil spill greater than or equal to
                   1,000 bbl will seldom contact and affect nearshore areas (coastline) critical to the feeding of the brown pelican,
                   Arctic peregrine falcon, and piping plover.










                                                                                                                             IV-229


                Summary

                   The brown pelican, Arctic peregrine falcon, bald eagle, and piping plover may be impacted by helicopter
                and service-vessel traffic, onshore pipeline landfalls, entanglement in and ingestion of offshore oil- and gas-
                related plastic debris, and off spills. The effects of these activities are expected to be sublethal. Lethal effects
                are expected only from oil spills greater than or equal to 1,000 bbl. Sale-related off spills of any size are
                expected to seldom contact threatened and endangered birds or their critical feeding, resting, or nesting
                habitats.


                Conclusion

                   The impact of the Base Case scenario on endangered and threatened birds within the potentially affected
                area is expected to result in no discernible decline in a population or species, and no change in distribution
                and/or abundance on a local or regional scale. Individuals experiencing sublethal effects will recover to
                predisturbance condition in less than one generation.

                High Case Analysis

                   It is assumed that helicopter traffic will occur on a regular basis, averaging about 31,000 trips per year.
                The FAA Advisory Circular 91-36C prohibits the use of fixed-wing aircraft lower than an elevation of 152 in
                and helicopters lower than 300 m during the period of October 15 through April 15 in the vicinity of numerous
                national wildlife refuges in the Gulf of Mexico to prevent disturbances to the birds (Biological Opinion - Section
                7 Consultation, Proposed Exploration Plans for OCS in the Gulf of Mexico; FWS/OES 375.0). The majority
                of these wildlife refuges provide critical habitats (feeding, resting, or nesting areas) for endangered and
                threatened species. Although interactions may occur and be disruptive, effects are expected to be sublethal
                and at worst of a temporary nature. It is expected that helicopter traffic near critical feeding, resting, or nesting
                habitats will seldom disturb the brown pelican, Arctic peregrine falcon, bald eagle, or piping plover because
                of special prohibitions and adherence to the general FAA-recommended minimum ceiling of 300 m.
                    It is assumed that about 880 OCS-related oil and gas service-vessel trips will occur annually as a result of
                the proposed action and that during the 35-year fife of the proposed action 5 shuttle tanker trips will occur
                (Table IV-2). These trips represent a meager amount of the total annual vessel traffic in the Gulf of Mexico.
                Most OCS-related off and gas traffic occurs in and out of existing port areas that are well away from critical
                habitats for feeding, resting, or nesting areas of the Arctic peregrine falcon, bald eagle, or piping plover. Some
                OCS-related service vessel traffic occurs in the vicinity of Cameron, Intracoastal City, Morgan City, and Venice,
                Louisiana, within several miles of critical habitats (feeding, resting, or nesting areas) for the brown pelican.
                Although incidents may occur and be disruptive, effects are expected to be sublethal and, at worst, of a
                temporary nature. It is expected that service-vessel traffic will seldom disturb the brown pelican.
                    Disturbance of brown pelican and piping plover critical habitats (feeding, resting or nesting areas) from
                pipeline landfalls and onshore construction could result in a reduction or desertion of birds that use the
                habitats. It is assumed that no new OCS oil- and gas-related pipeline landfalls or coastal facilities will be
                constructed as a result of the proposed action in the CPA. It is estimated that pipeline landfalls and onshore
                construction will not interact with critical feeding, resting, or nesting habitats of the brown pelican, Arctic
                peregrine falcon, or piping plover.
                    The brown pelican, Arctic peregrine falcon, bald eagle, and piping plover can become entangled in or
                ingest trash and debris. Interaction with plastic materials can be especially injurious. The MMS prohibits the
                disposal of equipment, containers, and other materials into off-shore waters by lessees (30 CFR 250.40). In
                addition, MARPOL, Annex V, Public Law 100-220 (101 Statute 1458), which prohibits the disposal of any
                plastics at sea or in coastal waters, went into effect January 1, 1989. It is assumed that very little trash and
                debris will be lost into the Gulf of Mexico as a result of the proposed action. Although interactions may occur,
                effects are expected to be sublethal. It is expected that the brown pelican, Arctic peregrine falcon, bald eagle,
                and piping plover will seldom become entangled in or ingest OCS-related trash and debris.










                   IV-230

                        In the event that offing of the brown pelican, Arctic peregrine falcon, bald eagle, or piping plover should
                   occur from sale-related oil spills greater than or equal to 1,OW bbl, the effects would primarily be sublethal;
                   few mortalities are expected. The effects of sale-related oil spills less than 1,000 bbl are expected to be
                   sublethal. In the event that sale-related oil spills of any size should occur in critical feeding, resting, or nesting
                   habitats, such as inshore, intert;dal, and nearshore areas, of the brown pelican, Arctic peregrine falcon, and
                   piping plover, sublethal effects are expected. The extent and severity of effects from sale-related on spills Will
                   be lessened by improved coastal off-spill contingency planning and response, deterrence of birds away from the
                   oiled area, and increased percentage of survival from rehabilitation efforts (Section IV.C.5.).
                        Section IV.C.1. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                   in the CPA- It is assumed that 47 offshore spills and fewer than 10 onshore spills greater than 1 and 'less than
                   or equal to 50 bbl will occur during the 35-year life of the proposed action. Few of the offshore spills will
                   contact the coastline. It is assumed that 2 offshore spills greater than 50 and less than 1,000 bbI min occur
                   during the 35-year life of the proposed action and that they will not contact the coastline. Although an
                   interaction with chronic spills may occur, only sublethal effects are expected. It is estimated that small spills
                   will seldom contact and affect the brown pelican, Arctic peregrine falcon, bald eagle, and piping plover.
                        Section IV.C.1. estimates the mean number of oil spills greater than or equal to 1,000 bbl resulting from
                   the proposed action in the CPA. It is assumed that one crude oil spill greater than or equal to 1,000 bbl will
                   occur from either a platform or pipeline in the Central Gulf during the 35-year life of the proposed action
                   (median size is 6,500 bbl). Table IV-21 identifies the estimated risk of one or more oil spills greater than or
                   equal to 1,000 bbl occurring and contacting within 10 days critical habitats for feeding, resting, or nesting of
                   the brown pelican, Arctic peregrine falcon, bald eagle, and piping plover in the CPA- The highest probability
                   of one or more oil spills greater than or equal to 1,000 bbl occurring and contacting within 10 days a coastal
                   bay in the Central Gulf is 2 percent (Timbalier Bay). The highest estimated probability of one or more spills
                   greater than or equal to 1,000 bbl occurring and contacting within 10 days deltaic manshes is 2 percent.
                   Although an interaction with spills greater than or equal to 1,000 bbl may occur, primarily sublethal effects are
                   expected with infrequent mortalities. It is expected that an oil spill greater than or equal to 1,000 bbl will
                   seldom contact and affect the brown pelican, Arctic peregrine falcon, bald eagle, and piping plover in the CPA.
                        Some feeding habitats of the brown pelican, Arctic peregrine falcon, and piping plover occur nearshore.
                   The highest estimated probability of one or more spills greater than or equal to 1,000 IN occurring and
                   contacting within 10 days nearshore areas (coastline) along the Central Gulf is 2 percent. Although an incident
                   may occur, sublethal effects are expected. It is estimated that an off spill greater than or equal to 1,000 bbi
                   will seldom contact and affect nearshore areas (coastline) critical to the feeding of the brown pelican, Arctic
                   peregrine falcon, and piping plover.
                        The brown pelican, Arctic peregrine falcon, bald eagle, and piping plover may be impacted by helicopter
                   and service-vessel traffic, onshore pipeline landfalls, entanglement in and ingestion of offshore off- and gas-
                   related plastic debris, and off spills. The effects of these activities are expected to be sublethal. Lethal effects
                   are expected only from oil spills greater than or equal to 1,000 bbL Sale-related oft spills of any size are
                   expected to seldom contact threatened and endangered birds or their critical habitats for feeding, resting, or
                   nesting habitats.

                   Conclusion


                        The impact of the High Case scenario on endangered and threatened birds within the potentially affected
                   area is expected to result in no discernible decline in a population or species, and no change in distribution
                   and/or abundance on a local or regional scale. Individuals experiencing sublethal effecis will recover to
                   predisturbance condition in less than one generation.

                   (8) Impacts on the Gutf Sturgeon

                        Oil can affect Gulf sturgeon by direct ingestion or ingestion of prey, by absorption through gills and
                   epithelium, and by mortality of eggs and larvae (NRC, 1985). Linden et al. (1979) notes that life stages with










                                                                                                                             IV-231

                 limited mobility are most susceptible to off. He also discusses how the stress of contacting oil, combined with
                 other environmental factors, can impair the functioning and survival of fish. Oil spills are the only activity
                 associated with the proposed action that are likely to impact the Gulf sturgeon. The analysis discusses oil spins
                 of three different sizes because of the difference in their frequency and rate of dispersion.

                 Base Case Ana4uis

                     Contact with or ingestion/absorption of off can result in mortality or sublethal effects. Section W.C.I.
                 estimates that 21 offshore spins and fewer than 10 onshore spills greater than I and less than or equal to 50
                 bbl will occur in the CPA- Few are assumed to occur from pipelines in the Louisiana coastal zone and several
                 from shuttle tankers/barges near terminals in the coastal zone. The spills will originate from areas with the
                 greatest density of platforms and largest volume of pipeline flow. Few of the 21 spills will contact the coast.
                 Based on the number and rate of these spills and their rate of dispersion (Sections IV.C.1. and 2.), the
                 assumption is that juvenile or adult Gulf sturgeon will contact or ingest hydrocarbons from these spills. Few
                 mortalities are expected; primarily sublethal effects are expected. No eggs or larvae will be contacted because
                 there is no spawning near OCS oil and gas activities.
                     It is assumed that one offshore spill greater than 50 and less than 1,000 bbI will occur during the 35-year
                 life of the proposed action, but it will not contact the coastline. The occurrence of a single spin less than 1,000
                 bbl suggests that Gulf sturgeon will not be contacted.
                     Section IV.C.1. estimates that one oil spill greater than or equal to 1,000 bbI (median size of 6,500 bbl)
                 will occur in the CPA during the 35-year life of the proposed action. There is a 1 percent probability that an
                 oil spill greater than or equal to 1,000 bbl would occur and contact within 10 days coastal Plaquemines and
                 Terrebonne Parishes in Louisiana. All other coastal areas have less than a 0.5 percent probability of an
                 occurrence and contact This analysis assumes that Gulf sturgeon will not ingest or contact hydrocarbons from
                 a spill greater than or equal to 1,000 bbl.

                 Summary

                     The Gulf sturgeon can be impacted by oil spills resulting from the proposed action.

                 Conclusion


                     The impact of the Base Case scenario on the Gulf sturgeon within the potentially affected area is expected
                 to result in sublethal effects and cause short-term physiological or behavioral changes.

                 High Case Ana4wis

                     Table IV-2 estimates that 47 offshore spills and fewer than 10 onshore spills greater than 1 and less than
                 or equal to 50 bbI will occur in the CPA. A few are assumed to occur from pipelines in the Louisiana coastal
                 zone and several from shuttle tankers/barges near terminals in the coastal zone. The small spins will originate
                 from areas with the greatest density of platforms and largest volume of pipeline flow. Few of the 47 spills win
                 contact the coast. Based on the number and rate of these spills and their rate of dispersion (Sections IV.C.1.
                 and 2.), the assumption is that juvenile or adult Gulf sturgeon will contact or ingest hydrocarbons from these
                 spills. Few mortalities are expected; primarily sublethal effects are expected. No eggs or larvae will be
                 contacted because there is no spawning near OCS oil and gas activities.
                     It is assumed that two offshore spins greater than 50 and less than 1,000 bbI will occur during the 35-year
                 life of the proposed action, but they will not contact the coastline. The occurrence of two spills suggests that
                 Gulf sturgeon will not be contacted.
                     Section IV.C.1. estimates that one oil spill greater than or equal to 1,000 bbl (median size of 6,500 bbl)
                 will occur in the CPA during the 35-year life of the proposed action. There is a 2 percent probability that one
                 or more oil spills greater than or equal to 1,000 bbl would occur and contact within 10 days Gulf sturgeon
                 habitat in coastal Plaquemines and Terrebonne Parishes and a 1 percent probability of occurrence and contact










                 IV-232

                 within 10 days in Barataria Bay, Louisiana. All other coastal areas have less than a 0.5 percent probability of
                 an occurrence and contact within 10 days. This analysis assumes that Gulf sturgeon will not ingest or contact
                 hydrocarbons from a spill greater than or equal to 1,000 bbL

                 Conclusion

                     The impact of the High Case scenario on the Gulf sturgeon within the potentially affected area is expected
                 to result in sublethal effects and cause short-term physiological or behavioral changes.

                 (9) Impacts on Commercial Fisheyies

                     Effects on commercial fisheries from activities associated with the proposed action o:)uld come from
                 emplacement of production platforms, underwater OCS obstructions, production platform removals, seismic
                 surveys, off spins, subsurface blowouts, and OCS discharges of drilling muds and produced waters. Potential
                 effects from these impact-producing factors are described below.
                     Sections providing supportive material for the commercial fisheries analysis include Sections III.B.6.
                 (description of fish resources), III.C.3. (commercial fishing stocks and activities), IV.A-2.d.(3) (use conflicts),
                 IV.A.2.b.(I) (pipelines), IV.A.2.a.(3) (structure removal), IV.A-2.a.(l) (seismic operations), IV.C.3. (oil spins),
                 IV.A.2.d.(8) (subsurface blowouts), IV.A.2.d.(5) (offshore discharges), and IV.A.3.c.(5) (onshore discharges).
                     The emplacement of a production platform, with a surrounding 100-m navigational safety zone, results in
                 the loss of approximately 6 ha of bottom trawling area to commercial fishermen and causes space-use conflicts.
                 Gear conflicts from underwater OCS obstructions such as pipelines result in losses of trawls and shrimp catch,
                 business downtime, and vessel damage. However, all pipelines in water depths less than 69 ni (200 ft) will be
                 buried, and their locations made public knowledged (Alpert, 1990). Although Gulf fishermenare experiencing
                 some economic loss from gear conflicts, the economic loss for a fiscal year has historically been less than 1
                 percent of the value of that same fiscal year's commercial fisheries'landings. In addition, most financial losses
                 from gear conflicts are covered by the Fishermen's Contingency Fund (FCF).
                     Lessees are required to remove all structures and underwater obstructions from their leases in the Federal
                 OCS within one year of the lease's relinquishment or termination of production. In 1990, MMS processed 97
                 structure removals. More platforms are removed by severing platform pilings with plastic explosives placed
                 5 in below the seafloor. The concussive force is lethal to fish that have internal air chambers (swirn bladders),
                 are demersal, or are in close association with the platform being removed (Caillouet and Landry, 1989). Within
                 the past decade, stocks of demersal reef fish (snappers) have declined in the Gulf. There is concern over a
                     ible connection between this decline and the explosive removal of platforms. To examine this issue of
                 possi
                 concern, MMS has funded a study, scheduled to begin in 1992,         of fish mortality associated with structure
                 removal. This study will further attempt to relate the role of fish mortalities from platform removals to the
                 status of reef fish stocks in the Gulf of Mexico (USDOI, MMS, 1990a).
                     The sources of acoustical pulse used in seismic surveys are generated by airguns. Airguns have little effect
                 on even the most sensitive fish eggs at distances of 5 m from the discharge (Falk and Lawrence, 1973). In
                 general, the acoustical pulse from airguns has relatively little effect on marine invertebrates, presumably due
                 to their lack of a swim bladder. Available scientific information concerning the effects of acoustic airgun
                 sources on fish eggs and larvae indicates that commercial fishery resources are little disturbed by seismic
                 surveys (Wingert, 1988).
                     When an oil spill occurs, many factors interact to limit the severity of effects and the extent of damage
                 to commercially important fish populations. The direct effects of spilled oil on fish occur through the ingestion
                 of oil or oiled prey, the uptake of dissolved petroleum products through the gills and epithelium by adults and
                 juveniles, and through mortality of eggs and decreased survival of larvae (NRC, 1985). Adult finfish themselves
                 may actively avoid an oil spill, thereby limiting the effects and lessening the extent of damage to their
                 population. When contacted by spilled oil, floating eggs and larvae, with their limited mobility, and most
                 juvenile fish are killed (Linden et al., 1979; Longwell, 1977). Ordinary environmental stresses may increase the










                                                                                                                           IV-233

               sensitivity of fish to oil toxicity. These stresses may include changes in salinity, temperature, and food
               abundance (Evans and Rice, 1974; NRC, 1985).
                    The effects from oil spills less than 1,000 bbl differ in severity and kind from those of spills greater than
               or equal to 1,000 bbl. An OCS-related spill greater than or equal to 1j000 bbI certainly can be a long-term
               catastrophic event; however, such an event seldom occurs and the oil will eventually disappear due to physical-
               chemical processes and complex degradation (NRC, 1985). On a much smaller scale, off spills less than 1,000
               bbl may not have the same immediate effect that a spill greater than 1,000 bbl has on commercial fishery
               resources, but if such events are relatively common, spills less than 1,000 bbl may be a more serious problem,
               causing continued irritation and/or sublethal toxic effects. Less severe, sublethal effects are defined as those
               that impair the ability of an organism to function effectively without causing direct mortality (Linden et al.,
               1979).
                    The effects on and the extent of damage from an oil spill to Gulf commercial fisheries is restricted by time
               and location. Oil spills that contact coastal bays, estuaries, and waters of the OCS when high concentrations
               of pelagic eggs and larvae are present have the greatest potential to damage commercial fishery resources.
               Migratory species, such as mackerel, cobia, and crevalle could be impacted if oil spills contact nearshore open
               waters. The majority of the Gulfs fishes are estuary dependent. The effects from an oil spill contacting a large
               area of a Gulf estuary would be considerable on local populations of commercial fishery resources, such as
               menhaden, shrimp, and blue crabs, that use that area as a nursery and/or spawning ground. The effects from
               chronic oiling in Gulf coastal wetlands would be substantial on all life stages of a local population of a sessile
               fishery resource such as oysters.
                    For OCS-related oil spills to have a substantial effect on a commercial fishery resource, whether estuary
               dependent or not, a large number of eggs and larvae would have to be concentrated in the immediate spill
               area. Oil components also would have to be present in highly toxic concentrations when both eggs and larvae
               were in the pelagic stage (Longwell, 1977). There is no evidence at this time that commercially important Gulf
               fishery resources have been adversely affected on a regional population level by spills or chronic oiling (NRC,
               1985). The effects may be masked by natural fluctuations in populations and our present crude stock
               assessment methods (NRC, 1985).
                    Subsurface oil-well blowouts resuspend sediments and release varying amounts of hydrocarbons into the
               water column (USDOI, MMS, 1987a). Both effects may be detrimental to commercial fishery resources.
               Resuspended sediments may clog gill epithelia of both finfish and shellfish with resultant smothering.
               Settlement of resuspended sediments may directly smother invertebrates or cover burrows of commercially
               important shellfish. Released aromatic hydrocarbons can have the same effects as spilled oil. Suspended
               sediments from blowouts are mostly redeposited within a few hundred meters from the blowout site. Released
               hydrocarbons are diluted to background levels within a few hundred meters of the blowout site and degrade
               quickly without major biological effect. Subsurface gas well blowouts are less of an environmental risk, resulting
               in resuspended sediments and short-term, increased levels of natural gas very near the source of the blowout.
               Natural gas consists mainly of nontoxic methane, which rapidly disperses upward into the air (Van Buuren,
               1984).
                    Commercial fishery resources could also be adversely affected by the discharge of drilling muds and
               produced waters. Drilling muds contain materials toxic to marine fishes; however, this is only at concentrations
               four or five orders of magnitude higher than those found more than a few meters from the discharge point
               (NRC, 1983). Further dilution is extremely rapid in offshore waters to the extent that every substance
               measured in the water column is at background levels at a distance of 1,000 m of the discharge point (Ecomar,
               Inc., 1980).
                    In addition to toxic trace elements and hydrocarbons in produced waters, there are additional components
               and properties, such as hypersalinity, organic acids, and radionuclides, that have a potential to affect
               commercial fishery resources adversely. Produced waters that are discharged offshore are diluted, dispersed
               rapidly, and undetectable at a distance of 1,000 m from the discharge point, and detectable effects are limited
               to within 300 in of the source (Harper, 1986; Rabalais et al., 1991). There will be no onshore discharge of
               produced water from the proposed action. Produced water will be disposed of onshore by reinjection or
               discharge into the Mississippi River (Section IV.B.I.c.(3)(d.).










                  IV-234

                  Base Case Ana6u&

                      The major impact-producing factors analyzed below are related to the proposed action and include
                  underwater OCS obstructions, OCS drilling mud discharge, production platform removal, production platform
                  emplacement, OCS produced-water discharge, seismic surveys, oil spills, and subsurface blowouts.
                      Gear conflicts are caused by underwater OCS obstructions such as pipelines. Section IV..&2.b.(I) estimates
                  the kilometers of offshore pipeline resulting from the proposed action in the CPA. It is exp-.cted that 240 kin
                  of pipeline will be installed in the CPA during the 35-year life of the proposed action (Table IV-2). In Subarea
                  C-1, the area of concentrated bottom trawl fishing, only 20 percent, or 48 kin, of pipeline will be installed
                  during the 35-year life of the proposed action, with 8 kin installed during the peak year. Gear conflicts are
                  mitigated by the FCF. During FY 90, 198 claims were processed, with 77 percent being approved for a total
                  of $836,798. This economic loss from gear conflicts for FY 90 was less than 0.1 percent of the value ($640
                  million) of Gulf commercial fisheries landings for 1990. For the purpose of this analysis, :it is assumed that
                  installed pipelines will seldom conflict with bottom trawl fishing and will have a negligible effect on Central Gulf
                  fisheries.
                      Drilling mud discharges (Table IV-2) contain chemicals toxic to marine fishes; however, this Ls only at
                  concentrations four or five orders of magnitude higher than those found more than a few meters from the
                  discharge point Offshore discharges of drilling muds will rapidly dilute to background levels and have a
                  negligible effect on Central Gulf fisheries.
                      Structure removal results in artificial habitat loss and causes fish kills when explosives are used. Section
                  IV.A-4.b.(5) estimates that 20 structure removals using explosives will occur in the CPA during the 35--year life
                  of the proposed action. It is assumed that these removals will occur during the last 12 year; of the life of the
                  proposed action and no more than 5 will occur in any single year (Table IV-2). For the purpose of this
                  analysis, it is assumed that structure removals will have a negligible effect on Central Gulf fisheries because
                  removals kill only those fish proximate to the removal site.
                      Thirty offshore platform complexes (Table IV-2) are expected to result from the proposed action,
                  eliminating 120 ha. (296 ac) of the trawling area during the peak year of activity of the proposed action in the
                  CPA. In Subarea C-1, the area of concentrated bottom trawl fishing, only 6 platform (omplexes win be
                  installed, eliminating 90 ha (223 ac). For the purpose of this analysis, it is assumed that space-use conflicts
                  seldom occur. The effect of space loss to trawl fishing in the Gulf from the construction of platforms is
                  negligible because the extent of the area lost to commercial trawling is less than 0.01 percent of the ava ilable
                  trawl fishing area in either Subarea C-1 or in the CPA-
                      Seismic surveys will occur in both coastal and offshore areas of the CPA. For purposes of this analysis,
                  it is assumed that seismic surveys will have a negligible effect on Gulf commercial fisheries because of the use
                  of airguns.
                      In the event that sale-related oil spills should occur in coastal bays, estuaries, and waters of the OCS
                  proximate to mobile adult finfish or shellfish, the effects and the extent of damage are expected to be limited
                  and lessened due to some capability of adult fish to avoid an oil spill, to metabolize hydirocarbons, and to
                  excrete both metabolites and parent compounds from their gills and liver. For floating, eggs and larvae
                  contacted by spilled oil, the effect is expected to be lethal. The effect of oil spills on commercial fishery
                  resources is expected to result in a partial, long-term decrease in a commercial population, in an essential
                  habitat, or in local fishing activity.
                      Section IV.C.l. estimates the mean number of oil spills less than 1,000 bbl resulting ftom the proposed
                  action in the CPA. It is assumed that 21 spills greater than I and less than or equal to 50 bbl win occur
                  offshore during the 35-year life of the proposed action. Few of the total spills will contact the coastline. It is
                  assumed that 1 offshore spill greater than 50 and less than 1,000 bbl will occur during the 35-year life of the
                  proposed action but it will not contact the coastline. For the purpose of this analysis, it is assumed that spills
                  less than 1,000 bbl will seldom contact and affect the coastal bays and marshes critical to the well-being of
                  commercial fisheries in the CPA-
                      Section IV.C.I. estimates the mean number of oil spills greater than or equal to 1,000 IN resulting from
                  the proposed action in the CPA. It is assumed that one crude oil spill greater than or equal to 1,000 bbl
                  median size is 6,500 bbl will occur from either a platform or pipeline in the Central Gulf during the 35-year










                                                                                                                           IV-235

                life of the proposed action. Table IV-21 identifies the estimated risk of one or more off spills greater than or
                equal to 1,000 bbl occurring and contacting within 10 days the coastal bays and marshes critical to the well-
                being of commercial fisheries in the CPA. The highest probability of one or more oil spills greater than or
                equal to 1,000 bbl occurring and contacting within 10 days a coastal bay in the Central Gulf is 1 percent
                (Timbalier Bay). The highest estimated probability of one or more spills greater than or equal to 1,000 bbl
                occurring and contacting within 10 days deltaic marshes is 1 percent. For the purpose of this analysis, it is
                estimated that an oil spill greater than or equal to 1,000 bbl will seldom contact and affect the coastal bays and
                marshes critical to the well-being of commercial fisheries in the CPA.
                    Although the quantity of commercial landings in the CPA of migratory species is comparatively small, these
                species are of high value. Migratory species could be affected by off spills occurring in the coastal area. The
                highest estimated probability of one or more spills greater than or equal to 1,000 bbl occurring and contacting
                within 10 days nearshore and coastal areas along the Central Gulf is 2 percent. For the purpose of this
                analysis, it is estimated that an oil spill greater than or equal to 1,000 bbl will seldom contact and affect
                nearshore and coastal areas critical to migratory commercial fisheries in the CPA-
                    Oil spills greater than or equal to 1,000 bbl originating in port from OCS-related tankering include those
                that may occur and contact coastal bays, estuaries, and nearshore areas. It is assumed that no spills greater
                than or equal to 1,000 bbl from tankering will occur and contact within 10 days a Central Gulf bay, estuary,
                or nearshore area. For the purpose of this analysis, it is estimated that an oil spill greater than or equal to
                1,000 bbl and that is OCS-related will not interact with Gulf commercial fisheries.
                    Subsurface blowouts of both oil and natural gas wells are detrimental to commercial fishery resources.
                Loss of well control and resultant blowouts seldom occur on the Gulf OCS (only 157 out of approximately
                27,000 exploration and development wells since 1956, with 12 resulting in the release of more than one barrel
                of oil). It is assumed that there will be 4 blowouts in the CPA resulting from the proposed action during the
                35-year life of the proposed action. For the purpose of this analysis, it is assumed that the infrequent
                subsurface blowout the may occur on the Gulf OCS will have a negligible effect on Gulf commercial fisheries.

                Summary
                    Activities resulting from the proposed action have the potential to cause detrimental effects to Central Gulf
                commercial fisheries. It is expected that the effects from the major impact-producing factors on commercial
                fisheries in the CPA are inconsequential and of nominal occurrence. As a result, there will be little discernible
                disturbance to Gulf commercial fisheries.


                Conclusion

                    The impact of the Base Case scenario on commercial fisheries within the potentially affected area is
                expected to result in a short-term decrease in a portion of a population of commercial importance, in an
                essential habitat, or in commercial fisheries on a local scale. Any affected population is expected to recover
                to predisturbance condition in one generation.

                High Case Ana4osis

                    The High Case is an optimistic estimate of production and development of the proposed action. The
                major impact-producing factors analyzed in the High Case scenario are the same as for the Base Case and
                include underwater OCS obstructions, OCS drilling mud discharge, production platform removal, production
                platform emplacement, OCS produced water discharge, seismic surveys, oil spills, and subsurface blowouts.
                    Gear conflicts are caused by underwater OCS obstructions such as pipelines. Section IV.A-2.b. estimates
                the kilometers of offshore pipeline resulting from the proposed action in the CPA. It is expected that 400 km
                of pipeline will be installed in the CPA during the 35-year life of the proposed action. In Subarea C-1, the area
                of concentrated bottom trawl fishing, only 12 percent, or 48 km, of pipeline will be installed during the 35-year
                life of the proposed action, with 8 km installed during the peak year. Gear conflicts are mitigated by the FCF.
                During FY 90, 198 claims were processed with 77 percent being approved for a total of $836,798. This









                 IV-236

                 economic loss from gear conflicts for FY 90 was less than 0.1 percent of the value (SW million) of Gulf
                 commercial fisheries landings for 1990. For the purpose of this analysis, it is assumed that histalled pipelines
                 will seldom conflict with bottom trawl fishing and will have a negligible effect on Central Gulf fisheries.
                      Drilling mud discharges (Table IV-2) contain chemicals toxic to marine fishes; however, this is only at
                 concentrations four or five orders of magnitude higher than those found more than a few meters from the
                 discharge point. Offshore discharges of drilling muds will rapidly dilute to background levels and have a
                 negligible effect on Central Gulf fisheries.
                      Structure removal results in artificial habitat loss and causes fish kills when explosives are used. Section
                 IV.A-2.a.(3) estimates that 24 structure removals using explosives will occur in the CPA during the 35-year life
                 of the proposed action. It is assumed that these removals will occur during the last 12 years of the life of the
                 proposed action and no more than 8 will occur in any single year (Table IV-2). For the purpose of this
                 analysis, it is assumed that structure removals will have a negligible effect on Central Gulf fisheries because
                 removals will kill only those fish proximate to the removal site.
                      S&V offshore platform complexes and structures (Table IV-2) are expected to result from the proposed
                 action, eliminating 900 ha of the trawling area during the 35-year life of the proposed action in the CPA. In
                 Subarea C-1, the area of concentrated bottom trawl fishing, only 6 platform complexes will be bistalled,
                 eliminating 90 ha (223 ac). For the purpose of this analysis, it is assumed that space-use conflicts seldom occur.
                 The effect of space loss to trawl fishing in the Gulf from the construction of platforms is negligible because the
                 extent of the area lost to commercial trawling is less than 0.01 percent of the available trawl fishing area in
                 either Subarea C-1 or in the CPA-
                      Seismic surveys will occur in both coastal and offshore areas of the CPA- For purposes of this analysis,
                 it is assumed that seismic surveys will have a negligible effect on Gulf commercial fisheries because ofthe use
                 of airguns.
                      In the event that sale-related oil spills should occur in coastal bays, estuaries, and waters of the OCS
                 proximate to mobile adult firifish or shellfish, the effects and the extent of damage are expected to be: limited
                 and lessened due to some capability of adult fish to avoid an off spill and to metabolize hydrocarbons and to
                 excrete both metabolites and parent compounds from their gills and liver. For floating eggs and larvae
                 contacted by spilled oil, the effect is expected to be lethal. The effect of oil spills on commercial fishery
                 resources is ex:pected to result in a partial, long-term decrease in a commercial population, in an essential
                 habitat, or in local fishing activity.
                      Section IV.C.1. estimates the mean number of off spills less than 1,000 bbl resulting from the proposed
                 action in the CPA. It is assumed that 47 spills greater than 1 and less than or equal to 50 bbl will occur
                 offshore during the 35-year life of the proposed action. Few of the total spills will contact the coastline. It is
                 assumed that 2 offshore spills greater than 50 and less than 1,000 bbl will occur during the 35-year life of the
                 proposed action and that they will not contact the coastline. For the purpose of this analysis, it is assumed that
                 spills less than 1,000 bbl will seldom contact and affect the coastal bays and marshes critical to the well-being
                 of commercial fisheries in the CPA-
                      Section W.C.I. estimates the mean number of oil spills greater than or equal to 1,000 bbl resulting from
                 the proposed action in the CPA. It is assumed that one crude oil spill of 6,500 bbl will occur offshore from
                 a pipeline in the Central Gulf during the 35-year life of the proposed action. Table IV-21 identifies the
                 estimated risk of one or more oil spills greater than or equal to 1,000 bbl occurring and contacting within 10
                 days the coastal bays and marshes critical to the well-being of commercial fisheries in the CPA. The highest
                 probability of one or more oil spills greater than or equal to 1,000 bbl occurring and contacting within 10 days
                 a coastal bay in the Central Gulf is 2 percent (Timbalier Bay). The highest estimated probability of one or
                 more spills greater than or equal to 1,000 bbl occurring and contacting within 10 days deltaic marshes is 2
                 percent. For the purpose of this analysis, it is estimated that an oil spill greater than or equal to 1,000 bbl win
                 seldom contact and affect the coastal bays and marshes critical to the well-being of commercial fisheries in the
                 CPA.
                      Although the quantity of commercial landings in the CPA of migratory species is comparatively small, these
                 species are of high value. Migratory species could be affected by oil spills occurring in the coastal area. The
                 highest estimated probability of one or more spills greater than or equal to 1,000 bbl occurring and contacting
                 within 10 days nearshore and coastal areas along the Central Gulf is 4 percent. For the purpose of this











                                                                                                                            IV-237

                 analysis, it is estimated that an oil spill greater than or equal to 1,000 bbl will seldom contact and affect
                 nearshore and coastal areas critical to migratory commercial fisheries in the CPA.
                     Oil spills greater than or equal to 1,000 bbl originating in port from OCS-related tankering include those
                 that may occur and contact coastal bays, estuaries, and nearshore areas. It is assumed that no spills greater
                 than or equal to 1,000 bbI from tankering will occur and contact within 10 days a Central Gulf bay, estuary,
                 or nearshore area. For the purpose of this analysis, it is estimated that an oil spill greater than or equal to
                 1,000 bbl and that is OCS-related will not interact with Gulf commercial fisheries.
                     Subsurface blowouts of both off and natural gas wells are detrimental to commercial fishery resources.
                 Loss of well control and resultant blowouts seldom occur on the Gulf OCS (only 157 out of approximately
                 27,000 exploration and development wells since 1956, with 12 resulting in the release of more than 1 bbl of oil).
                 It is assumed that there will be 7 blowouts in the CPA resulting from the proposed action during the 35-year
                 life of the proposed action. For the purpose of this analysis, it is assumed that the infrequent subsurface
                 blowout on the Gulf OCS will have a negligible effect on Gulf commercial fisheries.
                     Activities resulting from the proposed action have the potential to cause detrimental effects to Central Gulf
                 commercial fisheries. It is expected that the effects from the major impact-producing factors on commercial
                 fisheries in the CPA are inconsequential and of nominal occurrence. As a result, there will be little discernible
                 disturbance to Gulf commercial fisheries.


                 Conclusion

                     The impact of the High Case scenario on commercial fisheries within the potentially affected area is
                 expected to result in a short-term decrease in a population of commercial importance, in an essential habitat,
                 or in commercial fisheries on a local scale. Any affected population is expected to recover to predisturbance
                 condition in one generation.

                 (10) Impacts on Recreational Resources and Activities

                 (a) Beach Use

                     Major recreational beaches are defined as those frequently visited sandy areas along the shoreline that are
                 exposed to the Gulf of Mexico and that support a multiplicity of recreational activity, most of which is focused
                 at the land and water interface. Included are Gulf Islands National Seashore, State parks and recreational
                 areas, county and local parks, urban beaches, private resort areas, and State and private environmental
                 preservation and conservation areas. The general locations of these beaches are indicated on Visual No. 2.
                     The value of recreation and tourism in the Gulf of Mexico coastal zone from Texas through Florida is
                 approaching $20 billion annually (USDOI, MMS, 1990a). A significant portion of these expenditures is made
                 in coastal counties, where major shoreline beaches are primary recreational attractions. Almost 190,000 people,
                 for example, visited the beaches and outer Mississippi islands of the Gulf Islands National Seashore during FY
                 1990, demonstrating the popularity of destination beach parks throughout the CPA as recreational resources.
                     The primary impact-producing factors associated with offshore oil and gas exploration and development,
                 and most widely recognized as major threats to the enjoyment and use of recreational beaches, are trash and
                 debris and oil spills. Additional factors such as the physical presence of platforms and drilling rigs can affect
                 the aesthetics of beach appreciation (Section IV.A_2.d.(4)(c)), and noise from aircraft can disturb the ambience
                 of a beach-related recreation experience (Section IV.A.3.a.(l)(b)). All these factors, either individually or
                 collectively, may adversely affect the number and value of recreational beach visits.
                     Off spills can be associated with either the exploration, production, or transportation phases of OCS
                 operations. Major oil spills contacting recreational beaches can cause short-term displacement of recreational
                 activity from the areas directly affected and will lead to closure of beaches directly impacted for periods of 2-6
                 weeks, or until the cleanup operations are complete. When an oil spill occurs, other factors such as season,
                 publicity, extent of pollution, beach type and location, condition and type of oil washing ashore, tidal action,










                  IV-238

                  and cleanup methods, if any, can have a bearing on the severity of effects a spill may have on a recreational
                  beach and its use.
                      Widely publicized and investigated oil spill events, such as the Santa Barbara spill of 1969, the Lrtoc spill
                  in 1979 (Restrepo and Associates, 1982), the Alvenus tanker spill of 1984, and the 1989 Exron Valdez tanker
                  .accident in Prince William Sound, Alaska, have demonstrated that oil spins greater than or equal to 1,000 bbl
                  can severely impact beaches and their recreational use. However, findings from an indepth study of the Lrtoc
                  off-spill. impact on three south Texas shoreline beach parks indicated no significant decrease in park visitations
                  as a result of the oil spill (Freeman et al., 1985). Sorensen (1990) reviewed the socioeconomic effects of
                  several historic major oil spills on beaches and concluded a spill near a coastal recreation area would reduce
                  visitation in the area by 5-15 percent over one season, but would have no long-term effect on tourism.
                      Section IV.C. presents available information on the historic oil spins from OCS operations in the Gulf,
                  discusses the OSRA model developed for this EIS, and provides information on the extent and effectiveness
                  of existing containment and cleanup capabilities. Most relevant to this impact analysis are the assumptions
                  concerning the characteristics and fates of a Gulf of Mexico oil spill, indicating that the majority of oil spins
                  occurring in the Gulf are estimated to dissipate rapidly, and that only relatively small fractions are subject to
                  tarball formation because of the chemical properties of many northern Gulf fight crude oils. (Tarballs are
                  known to persist as long as 1-2 years in the marine environment.) The analysis of spills greater than or equal
                  to 1,000 bbl assumes that an originating slick acutely threatens shoreline recreational resources for up to 10
                  days, after which natural processes significantly change the nature and form of the pollutant to the point that
                  it is unlikely to be a major threat to beach recreational resources and activities.
                      Trash, debris, and tarballs from OCS operations can wash ashore on Gulf of Mexico recreational beaches
                  and reduce their attractiveness as recreational resources (Section IV.A_2.d.(5)). Some trash items, such as glass,
                  pieces of steel, and drums with chemical or chemical residues, can also be a health threat to users of
                  recreational beaches. Cleanup of OCS trash and debris from coastal beaches adds to operation and
                  maintenance costs for coastal beach and park administrators.
                      The physical presence of platforms and drilling rigs, when visible from shore (Section IV.A.2.d.(4)), and
                  noise associated with vessels and aircraft (Section IV.A_3.a.(I)(b)) traveling between coastal shore bases and
                  offshore operation sites can also adversely affect the natural ambience of primitive coastal beaches. Although
                  these factors may affect the quality of recreational experiences, they are unlikely to reduce the number of
                  recreation visits to coastal beaches in the CPA or WPA.

                  Base Case Ana4wis

                      Exploration and production on blocks leased in the Central Gulf of Mexico and transportation of produced
                  oil and gas could lead to oil spills of 1,000 bbI or greater (16% probability) (Table IV-19) throughout the 35-
                  year life of the proposed action (1993-2027). Wind, waves, and currents could result in spins reaching major
                  shoreline recreational beaches throughout the CPA and WPA. As evident from the Alvenus tanker accident,
                  oil spills greater than or equal to 1,000 bbl occurring in one region (CPA) can impact recreational resources
                  and activities in another region (WPA).
                      Estimates based on OSRA (Table IV-21) indicate the proposed action has an estimated probability less
                  than 0.5% chance to result in a 1,000 bbl or greater oil spill occurrence and contact (within 10 days) with any
                  major recreational beach anywhere in the Gulf region. It is assumed, therefore, for purposes of this analysis
                  that an off spill of 1,000 bbl or greater will not impact recreational beaches in the CPA. from operations
                  resulting from proposed Sale 142.
                      As noted in Section IV.C.I., three small spills every five years in the size class greater than I and less than
                  or equal to 50 bbl are assumed to occur during the 35-year project life. A few of these small spills are assumed
                  to contact recreational beaches during this 35-year period. Such spills can be cleaned from recreational
                  beaches with little disruption of normal recreational activities and with minimal effects on beach recreational
                  resources.
                      Some litter from OCS accidents, carelessness, and noncompliance with OCS antipollutk)n regulations and
                  directives is likely to come ashore on recreational beaches. New industry waste management practices, in
                  addition to training and awareness programs, focused on the beach litter problem are expected to minimize










                                                                                                                             IV-239

                 the level of indiscriminate and irresponsible trash disposal and accidental loss of solid wastes from OCS oil and
                 gas operations.
                    Recreational beaches in Louisiana and Texas are most likely to be impacted from this waterborne trash.
                 Incremental effects from the proposed action on litter are unlikely to be perceptible by beach users or
                 administrators because the activity from the proposal will constitute only a very small percentage of the existing
                 OCS activity in the CPA and is likely to be offset by the number of terminating leases in the next 35 years.
                 Litter on recreational beaches from OCS operations will adversely affect the ambience of the beach
                 environment, will detract from the enjoyment of beach activities, and can increase administrative costs on
                 maintained beaches.
                     Drilling rigs and platforms may be placed within sight of shoreline recreational beaches of coastal Subareas
                 C-1 and C-3. As most of the first three tiers of Federal lease blocks have already been leased off the coast of
                 Louisiana and Baldwin County, Alabama, it is only in a few unleased blocks off Louisiana, Mississippt and
                 Alabama where new leases may bring OCS operations within sight of coastal recreational beaches (Visual No.
                 1). The Mississippi Sound buffers OCS exploration and development from Mississippi mainland recreational
                 beaches; however, the first three tiers of Federal lease blocks off West Ship and Horn Islands are available for
                 lease. Therefore, users of a large portion of the Gulf Islands National Seashore and Wilderness Area in
                 Mississippi may be able to see OCS operations seaward from the south beaches on these islands. Assuming
                 one jack-up ripe drilling rig and one production platform will operate within these nearshore tracts as a result
                 of proposed Sale 142, they will be visible for an extended period of time (1-20 years) from portions of the
                 seaward beaches and wilderness areas within 10 mi of the oil and i!as exploratory and production operations.
                 In areas where they do not already exist, these structures will intr@duce a new and unnatural contrast to the
                 characteristic view of the seascape.
                     Proposed Sale 142 may also stimulate and redirect additional vessel and helicopter traffic. Over 6,000
                 vessel traffic trips and 123,000 helicopter trips are projected to result in coastal Subarea C-3 (Table IV-2).
                 Although most of these trips are likely to use the busy navigation channels between the Mississippi and
                 Atchafalaya Deltas, some new traffic around and above the Gulf Islands National Seashore is likely. Only 60
                 vessel trips are projected to use the Pascagoula/Bayou Casotte ship channel (Table IV-5) between Horn and
                 Petit Bois Islands (Visual No. 2) as a result of the proposal. With no helicopter hubs in coastal Mississippi and
                 only one in coastal Alabama, very little additional, if any, air traffic is expected over Gulf Islands National
                 Seashore and Wilderness Area from proposed Sale 142. On the assumption that vessels use established
                 nearshore traffic lanes and helicopters comply with areal clearance restrictions, boats and aircraft servicing
                 offshore and nearshore oil and gas operations may still be seen and heard by some recreational and wilderness
                 beach users, but the intermittent detection should not decrease the amount of recreational beach use.

                 Summaq
                     A few oil spills greater than I and less than or equal to 50 bbl are assumed to affect portions of CPA
                 beaches, with little disruption of recreational activities. Marine debris will be lost from time to time from OCS
                 operations associated with drilling 590 new wells and producing oil and gas from 30 new production locations
                 throughout the CPA over the next 35 years. However, the impact from the resulting intermittent pollution
                 washup on Louisiana and Texas beaches should be very low. A drilling rig and production platform in the
                 nearshore area off Louisiana and Mississippi could also impact the natural seascape from some wilderness
                 beaches in coastal Subarea C-3. Helicopter and vessel traffic will add very little additional noise pollution likely
                 to affect wilderness beach users.


                 Conclusion

                      The proposed action is expected to result in minor pollution events and nearshore operations that may
                 adversely affect the enjoyment of some beach users on Texas and Louisiana beaches.










                IV-240

                High Case Ana6uis

                     The causes and severity of impacts associated with the High Case scenario would be derived from the same
                impact-producing factors identified under the Base Case scenario, above. Included are oil spills, trash and
                debris, the physical presence of drilling rigs and platforms, and noise from vessels and helicopters.
                     The OSRA estimates (Table IV-21) indicate that, even with more optimistic oil and gas finds from this
                proposal, the estimated probability of an oil spill of 1,000 bbl or greater occurring and contacting a major
                recreational beach anywhere in the Gulf region within 10 days is estimated as less than 0.5% chance. With the
                number of wells drilled and the number of vessel traffic trips almost doubling, it is likely the kvel of accidental
                and irresponsible trash loss will also increase. Although the decibel level of noise impacting wilderness beach
                users from vessel and helicopter traffic will not increase, the frequency of these impacts is likely to increase;
                therefore, the number of visitors hearing and seeing vessels and helicopters while visiting Gulf Islands National
                Seashore and Wilderness Area or Breton Island National Wilderness Area will also increase. The number of
                platforms and drilling rigs operating within sight of wilderness beaches in coastal Subarea C-3 is unlikely to
                increase from the Base Case.


                Conclusion

                     The impact on recreational beach use within the CPA as a result of the High Case is expected to be the
                same as the Base Case even though the number of minor pollution incidences adversely affecting the ambience
                of recreational beaches is likely to increase throughout the 35-year life of the proposed action.
                (b) Marine Fishing

                     Reports (USDOC, NMFS, 1990a) indicating declining trends in catch and effort for marine recreational
                fishing, along with recently imposed and proposed State and Federal regulations limiting the size, number and
                seasons on some popular sport fish (viz., snapper, red drum, speckled trout), have focused broad public concern
                on the prospects for marine recreational fishing throughout the Gulf region. As noted in Section III.C.4.,
                studies, reports, and previous OCS sale analyses have shown that OCS platform development for oil and gas
                production has potential for causing a major change in the focus of offshore recreational fishing, both locally
                and regionally. That is not to say that oil spills, pipeline development, onshore support facilities, increased
                marine traffic, or other impacting factors likely to result from OCS operations will have no effect on
                recreational fishing. However, none of these impacting factors is likely to affect a major long-term change in
                the positive or negative aspects of offshore, nearshore, or inshore recreational fishing. Impacts to sports fishing
                caused by activities and pollution events associated with OCS oil and gas exploration and development will be
                localized, short-term, and minor when compared to the predictable long-term impacts resulting from the
                erection of major production platforms. An exception could result from the indirect effect on recreational
                fishing from a high regional impact affecting biological productivity. Major adverse consequences from 1993
                sales to the life-support systems of primary sport fishing species may ultimately affect recreational fishing.
                Section IV.D.La.(9) (commercial fisheries) contains a discussion on the generic effects of oil on fish and fish-
                dependent ecosystems. Major research indicates (NRC, 1985) there is no evidence that oil spills greater than
                or equal to 1,000 bbl or chronic oiling have adversely affected important Gulf sport fishery resources on a
                regional population scale.
                     Oil and gas structures attract fish and, inevitably, recreational fishermen and divers. The structures also
                provide a convenient and productive fishing resource for many people who work offshore. The National
                Marine Fisheries Service, based on public hearing testimony, has informed MMS that some offshore oil and
                gas workers and support industry personnel may be engaging in illegal fishing activities at petroleum platforms
                while stationed offshore.
                     The OCS environmental reports on the artificial reef effects of petroleum platforms conclude that
                structures concentrate large numbers of epibiota and fishes that would not be as abundantly represented in the
                same area in the absence of structures (Gallaway et al., 1981). Gallaway and Lewbel (1982) estimated that










                                                                                                                             IV-241

                 the 3,500 petroleum structures in the CPA and WPA in 1981 provided 4,000 acres of artificial reef habitat on
                 their vertical and horizontal supports. Because of the paucity of natural hard substrate in the Gulf, the more
                 than 4,500 petroleum structures in the Gulf today provide larval settlement opportunities much greater than
                 that naturally available. Gallaway has indicated some fish species may become permanently associated with
                 petroleum structures while others are seasonal transients.
                     Many of the fish species congregating around petroleum structures are prime sport fishing targets (snapper,
                 grouper, mackerels, cobia, etc.). The location and availability of desired sport fishing targets can be predicted
                 fairly accurately by selecting platform locations in depth zones and seasons known to harbor the desired species
                 (Reggio et al., 1983). Ditton and Graefe (1978), Dugas et al. (1979), and Witzig (1986) determined that oil
                 and gas structures are the most popular offshore fishing locations for private and charter boat fishermen in
                 portions of the Western and Central Gulf. As reported by Reggio and others at MMS Information Transfer
                 Meetings (USDOI, MMS, 1982b, pp. 47-75; 1984b, pp. 102-163; 1985b, pp. 297-341; and 1986b, pp. 101-119),
                 oil and gas structures are a major focus of all forms of offshore recreational fishing. Ditton and Auyong (1984)
                 studied the spatial use patterns of offshore platform fishermen in the CPA and determined most private
                 recreational fishing boats, scuba boats, and charter boats travel an average 12 to 47 mi offshore to catch and
                 enjoy fish associated with oil and gas structures. Gordon (1987) verified the importance of oil and gas
                 structures as recreational fishing attractions and determined some interesting facts from the 200 boating
                 fishermen he interviewed. Almost all were itinerant Louisianians willing to travel 220 mi per day by car and
                 boat for the opportunity to fish around offshore oil and gas structures. The typical fisherman trailered a 23-ft
                 boat 80 mi to the launch site and traveled 60 mi by boat to fish around 6 or 7 production platforms. The
                 offshore rig fisherman readily seeks out favorite platforms as far as 30 mi offshore and repeats this recreational
                 activity as many as 22 times per year.
                     It is assumed that people fish offshore for one of three major reasons: to catch more fish, bigger fish, or
                 fish not available inshore. Oil and gas structures are known to affect all these factors in a positive manner
                 (Witzig, 1986). Furthermore, some species not formerly harvested in some areas by recreational fishermen
                 have become regular fishing targets (pompano and cobia, for example, off the coast of Louisiana) since the
                 advent of offshore petroleum platforms. Offshore recreational fishermen make much larger capital investments
                 in boats and equipment and spend more on trip expenditures (gas, bait, groceries, etc.) than coastal and
                 nearshore marine fishermen. We are unaware of any specific studies of the direct economic impact of rig
                 fishing on the coastal area within the CPA and WPA, but believe it is significant. Roberts and Thompson
                 (1983) did study the use of offshore petroleum structures by Louisiana scuba divers and determined each
                 recreational diver was willing to pay on average more than $160 a year in 1981 to dive around oil and gas
                 structures.
                     Fishermen who travel several miles offshore to fish around petroleum structures sometimes encounter
                 problems brought on by imprudence, unexpected weather conditions, or mechanical problems. Ditton and
                 Auyong (1984) reported workers on offshore platforms -are called on to provide information and
                 communication, supplies and services, and medical aid and emergency rescue to offshore fishermen and boaters
                 seeking or desperately needing their assistance.
                     Some offshore sports fishing targets, such as snappers and groupers, are structure-faithful fish: i.e., they
                 are recruited to an artificial structure at some point in their life cycle and will remain associated with that
                 artificial habitat throughoutpart of their remaining lifetime (Gallaway et al., 1981; Gallaway and Lewbel, 1982).
                 Even though MMS-supported studies on the effects of oil and gas platforms on natural reefs have been
                 inconclusive (CSA, 1982), it is believed that new artificial reefs have little, if any, significant effect on the
                 carrying capacity or size distribution of fish on natural reefs (Stone et al., 1979). If a constant demand for fish
                 in space and time (fishing pressure) is assumed, the quantity and quality of offshore fishing will be enhanced
                 in direct proportion to the number and extent of accessible fishing stations or reefs within the fishery.
                     The 3,422 off and gas structures (Table IV-7) currently on the OCS in the CPA and WPA are de facto
                 artificial reefs augmenting the permitted artificial fishing reefs off the coasts of Louisiana, Mississippi, and
                 Alabama. Visual No. 1 charts the general location of these petroleum structures, and Visual No. 2 shows the
                 location of permitted reefs and established artificial reef planning areas in the CPA.










                 IV-242

                     Platform removals, especially when explosive detachments are used, are known to kill and adversely impact
                 nearby sport fish. Artificial reef programs established by the Gulf states and the rigs-to-reefs projects they
                 sponsor are helping to mitigate loss of fishing locations and fish affected by platform removals.

                 Base Case Ana4uis

                     The impacting factors considered in the Base Case analysis and discussed below include platform
                 installations and removals and off spills.
                     Table IV-2 projects the installation of 30 new platform complexes, most of which will be emplaced. in the
                 first 5-15 years of the 35-year life of the proposed action and will likely be removed in the Imst 12 years of the
                 proposed action. Offshore Subareas C-2 and C-4 are projected to be the locations of 14 of the platform
                 complexes resulting from the proposed sale. As these platforms will be located 45 or more railes from shore,
                 they are expected to have very little effect on offshore recreational fishing. The 6 platform complexes installed
                 in coastal Subarea C-1 will be located from 3 to 80 mi offshore and are likely to attract some recreational
                 fishermen. Likewise, the 10 platform complexes expected from this proposal in coastal Subarea C-3 could be
                 located within 30 mi of the Mississippi Delta area and attract some fishing use. Any platforms installed in the
                 northeastern portion of coastal Subarea C-3 within 30 mi of shore would likely be a primary focus of offshore
                 recreational fishermen from Mississippi and Alabama. There are about 3,000 production platforms off the
                 coast of Louisiana, and additional installations are unlikely to influence seriously the scope of Louisiana
                 offshore fishing. They could, however, influence individual fishermen who would visit these new platforms
                 during the estimated 20-year platform life span. The 16 new platform complexes installed in -coastal Subareas
                 C-1 and C-3 would replace fishing opportunities being lost through platform removal over the next 5-10 years
                 and would extend the time offshore platforms continue to be a principal focus of offshore recreational fishing
                 in the CPA.
                     The 30 platforms resulting from this proposed sale will be removed towards the end ofthe project life.
                 Therefore, those nearshore structures placed in coastal Subareas'C-1 and C-3 will be lost as fish-attracting
                 devices, thus negating their positive effects on recreational fishing. The removal of the platforms resulting from
                 this proposal with the use of explosives will kill or adversely impact the sport fish directly associated with the
                 structure at the time of removal, but will have no detectable effect on offshore fishing in general.
                     Even though there is an estimated 16 percent probability in the CPA for an oil spill of 1,(X)O bbI or greater
                 to result from the proposed sale (Table IV-19), such a spill is assumed not to impact marine recreational fishing
                 beyond the area of the oil slick and the short time it is detectable on the water.

                 Summary

                     The proposed action is expected to add, within 30 mi of shores, up to 16 new platform, complexes that
                 will function as high-profile artificial reefs and attract fish and fishermen from Louisiana, Mississippi@ and
                 Alabama. Although the number of offshore fishing trips is unlikely to increase as a result of the proposal,
                 fishing success is likely to increase in offshore areas near oil and gas structures. Because of the increasing
                 number and frequency of platform removals, this sale should help replace expected removah. and "tend the
                 era of "big" fishing in the CPA.

                 Conclusion

                     Platforms installed within 30 mi of shore will attract fish and are likely to attract fishermen and improve
                 fishing for a period of about 20 years, but are unlikely to affect offshore fishing patterns in general unless the
                 platforms are installed in nearshore locations where no platforms currently exist.

                 High Case Ana4uis

                     Under the High Case scenario it is estimated 6 platform complexes will be installed in coastal Subarea C-1
                 and 18 platform complexes will be installed in coastal Subarea C-3 (Table IV-2). Some of' these platform










                                                                                                                            IV-243

                complexes are expected to be located within 30 miles of shore and are likely to attract offshore marine
                fishermen and improve fishing prospects in the immediate vicinity of each structure. However, the new
                platforms would have little incremental effect on offshore fishing in general, especially in areas offshore
                Louisiana, where many offshore platforms already exist. Should several structures be installed in the nearshore
                tracts off Mississippi and Alabama, they would augment the existing artificial reef system and diversify and
                increase the productive fishing locations available to offshore fishermen in that area. Installations would lead
                to eventual removals towards the latter years of the project life. Removals negate the effects of installations
                on fishing and, when explosives are used, lead to the demise of sport fish directly associated with the structure
                at the time of removal.
                   The estimated probability of an oil spill of 1,000 bbl or greater occurring increases from 16 to 32 percent
                (Table IV-19); however, the overall effect of one such spill on offshore recreational fishing is assumed not to
                extend beyond the immediate area and short-term life of its associated slick.

                Conclusion

                   The High Case scenario will likely result in a few more platforms that will be productive sports fish areas
                accessible to and used by offshore recreational fishermen throughout the CPA, but the scenario is unlikely to
                have a detectable impact on the recreational fishing industry at the regional level. A few local fishing markets
                could suffer short-term (up to one month) loss of business from a major poUlution event; however, these same
                markets should experience long-term (15-20 years) benefit from platform installations accessible to local
                fishermen.

                (11) Impacts on Archaeological Resources
                    Lease blocks with a high probability for the occurrence of prehistoric, prehistoric and historic, or historic
                archaeological resources may by found in the Central Gulf. Those blocks with a high probability for prehistoric
                archaeological resources may be found landward of a line that roughly follows the 45-m bathymetric contour.
                The areas of the northern Gulf of Mexico that are considered to have a high probability for historic period
                shipwrecks have recently been redefined as a result of an MMS-funded study (Garrison et al, 1989). The
                redefinition of the high probability areas has reduced the total number of lease blocks with a high probability
                for shipwrecks from 3,410 to 2,263.
                    The study expanded the shipwreck database in the Gulf of Mexico from 1,500 to over 4,000 wrecks.
                Statistical analysis of shipwreck location data identified two specific types of high probability areas; the first
                within 10 kin of the shoreline, and the second proximal to historic ports, barrier islands, and other loss traps.
                High probability search polygons associated with individual shipwrecks were created to afford protection to
                wrecks located outside of the two aforementioned high probability areas. A new Notice to Lessees (NTL 91-
                02) has been issued concerning remote-sensing survey methodology and report writing requirements for
                archaeological resources in the Gulf of Mexico OCS. Briefly stated, the NTL increases remote-sensing survey
                linespacing density for historic shipwreck survey to 50 in from the previous 150 in. The NTL also requires
                submission of an increased amount of magnetometer data to facilitate in-house MMS analysis. Survey and
                report requirements for prehistoric site survey have not been changed. Since 1974, leases offered have
                contained an archaeological resource stipulation. Section II.Al.c.(3) presents a proposed stipulation as a
                potential mitigating measure for leases resulting from the proposed action, the impact analysis for which,
                including the proposed Archaeological Resource Stipulation, is presented below. It should be noted that a
                rulemaking, which will incorporate the archaeological stipulation into regulation under 30 CFR 250.25, has been
                proposed. Presently, lessees or operators are required to comply with the remote-sensing survey and report
                requirements upon invocation of the stipulation by MMS. The proposed rulemaking will convert the stipulation
                into an operational regulation.
                    Sections that provide additional supportive material for the archaeological resources analysis include
                Sections III.C.5. (description of archaeological resources), IV.A-4.b. (offshore infrastructure), IV.A.5.a. (onshore
                infrastructure), and IV.C.3. (oil spills).










                  IV-244

                      The OCS-related, impact-producing factors may cause adverse impacts to archaeological resources.
                  Damage caused by the placement of drilling rigs, production platforms, pipelines, dredging, and anchoring could
                  destroy artifacts or disrupt the provenience and stratigraphic context of artifacts, sediments, and paleoindicators
                  from which the scientific value of the archaeological resource is derived. Oil spills could destroy the ability to
                  date prehistoric sites by radiocarbon dating techniques. Ferromagnetic debris associated with OCS oil and gas
                  activities would tend to mask magnetic signatures of significant historic archaeological resources.
                      Offshore development could result in a drilling rig, platform, pipeline, dredging activity or anchors having
                  an impact on an historic shipwrecIL This direct physical contact with a wreck site could destroy fragile ship
                  remains, such as the huff and wooden or ceramic artifacts, and could disturb the site context. The result would
                  be the loss of archaeological data on ship construction, cargo, and the social organization of the vessel's crew,
                  and the concomitant loss of information on maritime culture for the time period from which the ship dates.
                      The placement of drilling rigs and production platforms has the physical potential to aiuse an impact to
                  prehistoric and/or historic archaeological resources. It may be assumed that the standard rig will directly
                  disturb 1.5 ha of soft bottom, the average platform 2 ha. Pile driving associated with platform emplacement
                  may also cause sediment liquefaction an unknown distance from the piling, disrupting stratigraphy in the area
                  of liquefaction.
                      Pipeline placement has the physical potential to cause an impact to prehistoric and/or historic
                  archaeological resources. Pipelines placed in water depths of less than 61 in (200 ft) must be buried. Burial
                  depths of I in (3 ft) are required with the exception of shipping fairways and anchorage areas, where the
                  requirements are 10 and 15 ft, respectively.
                      The dredging of new channels, as well as maintenance dredging of existing channels, has the physical
                  potential to cause an impact to historic shipwrecks (Espey, Huston, & Associates, 1990). There are 23
                  navigation channels that provide OCS access to onshore facilities. It may be assumed that one channel in the
                  Central Gulf will have to be deepened to provide access for larger offshore boats serving deeper waters.
                      Anchoring associated with platform and pipeline emplacement as well as service vessel and shuttle tanker
                  activities, may also physically impact prehistoric and/or historic archaeological resources. It may be assumed
                  that during pipeline emplacement, an array of eight 20,000-lb anchors is continuously repositioned.
                      Oil spills have the potential to affect both prehistoric and historic archaeological resources. Impacts to
                  historic resources would be limited to visual impacts and, possibly, physical impacts associated with spill cleanup
                  operations. Impacts to prehistoric archaeological sites would be the result of hydrocarbon contamination of
                  organic materials, which have the potential to date site occupation through radiocarbon dating techniques, as
                  well as possible physical disturbance associated with spill cleanup operations.
                      The OCS oil and gas activities will also generate tons of ferromagnetic: structures and debris, which will
                  tend to mask magnetic signatures of significant historic archaeological resources. The task of locating historic
                  resources through an archaeological survey is, therefore, made more difficult as a result of ]leasing activity.
                  (a) Historic

                  Base Case Ana4u&

                      Since likely locations of archaeological sites cannot be delineated without first conducting a remote-sensing
                  survey of the seabed and near-surface sediments, MMS, by virtue of the proposed Archaeological Resource
                  Stipulation (Section II.A.I.c.(3)), requires that an archaeological survey be conducted prior to development of
                  lease tracts within the high probability zones for historic and prehistoric archaeological resources. Generally,
                  in the eastern part of the CPA, where unconsolidated sediments are thicker, it is likely that sidescan sonar will
                  not detect shipwrecks buried beneath the mud. In this area, which begins nearshore around Vermilion Area
                  (USDOI, MMS, 1984a) and extends eastward (Subareas C-1, C-2, and C-3), the effectiveness of the survey for
                  detecting historic shipwrecks of composite and wooden construction would depend on the capability of a
                  magnetometer towed at a 50-m line spacing (as specified in NTL 91-02) to detect ferromagnetic masses of the
                  size characteristically associated with shipwrecks.       Clausen and Arnold (1975) have concluded that
                  magnetometer reliability for detecting ferrous objects at 150-m survey line spacing is 25-310 percent. It is










                                                                                                                              IV-245

              assumed that an initial survey at a 50-m line spacing will be 90 percent effective at locating historic shipwrecks.
              The survey would therefore reduce the potential for an impact to occur by an estimated 90 percent.
                  According to estimates presented in Table IV-2, under the Base Case, 590 exploration, delineation, and
              development wells will be drilled, and 30 production platforms and 240 kin of pipelines will be installed in the
              Central Gulf. Of this number, 410 exploration, delineation, and development wells will be drilled, and 16
              platforms and 129 kin of pipelines will be installed within Subareas C-1 and C-3, where the majority of lease
              blocks with a high probability for historic period shipwrecks are located. Under current survey requirements,
              as much as 10 percent of this activity would occur without accurate information about the proximity of the
              activity to an historic resource. The recent MMS study (Garrison et al., 1989) has refined the high probability
              area for the occurrence of historic period shipwrecks. The location of any proposed activity within a lease
              block that has a high probability for historic shipwrecks requires archaeological clearance prior to operations.
              Considering that the expanded database contains 273 shipwrecks in the entire Central Gulf OCS, the
              probability of an OCS activity contacting and damaging a shipwreck is very low. If an oil and gas structure
              contacted an historic resource, however, there could be a loss of significant or unique archaeological
              information.
                  In the western part of the CPA, where shipwrecks are more likely to be detected by sidescan sonar due
              to a thin Holocene sediment veneer overlying an indurated Pleistocene surface, the increased survey linespacing
              density (50 in) will reduce the potential for a direct physical contact between an impact-producing factor and
              a shipwreck by an estimated 95 percent. The effectiveness of the survey would reduce the potential impacts
              of OCS activities to historic shipwrecks in the western part of the CPA. There is a very small possibility that
              a historic shipwreck could be impacted by OCS activities. Should such an impact occur, however, significant
              or unique archaeological information could be lost.
                  Onshore historic properties include sites, structures, and objects such as historic buildings, forts, lighthouses,
              homesteads, cemeteries, and battlefields. Sites already listed on the National Register of Historic Places and
              those considered eligible for the Register have already been evaluated as being able to make a unique or
              significant contribution to science. At present, unidentified historic sites may contain unique historic
              information and would have to be assessed after discovery to determine the importance of the data.
                  Onshore development as a result of the proposed action could result in the direct physical contact between
              the construction of new onshore facilities or pipeline canals and previously unidentified historic sites. This
              direct physical contact with an historic site could cause physical damage to, or complete destruction of,
              information on the history of the region and the Nation. However, no new onshore pipelines or facilities are
              projected in the Base Case for proposed Sale 142. There is, therefore, no expected impact to onshore historic
              sites in the CPA from onshore development.
                  Maintenance dredging associated with the proposed action has the potential to impact an historic
              shipwreck. Maintenance dredging in the Port Mansfield Entrance Channel is believed to impact the Santa
              Maria de Yciar, which sank on April 29, 1554 (Espey, Huston & Associates, 1990). Table IV-6 indicates that,
              under the Base Case less than 0.1 percent of the ship traffic through the Port Mansfield Cut is related to OCS
              use. Therefore, the impact to the Santa Maria de Yciar directly attributable to OCS use as a result of the
              proposed action is extremely low. While the specific example falls within onshore Subarea W-1, an area
              unlikely to be affected by the CPA, it is reasonable to assume that the potential exists for historic shipwrecks
              to be impacted by dredging in the CPA. As this shipwreck is a unique historic archaeological resource, the
              impact level of maintenance dredging, in general, is considered to be very high. However, the portion of
              maintenance dredging attributable to the proposed action is, in the case of the Port Mansfield Entrance
              Channel, extremely low. According to Table IV-6, the percentage of OCS use under the Base Case among
              the 23 major navigation channels listed for the Central Gulf ranges from a low of less than 0.1 percent to a
              high of 2.2 percent.
                  Should an oil spill contact a coastal historic site, such as a fort or a lighthouse, the major impact would be
              visual because of off contamination of the site and its environment. According to Table IV-21, the probability
              of a spill occurring and contacting within 10 days the coast of the CPA is 2 percent under the Base Case. This
              impact would is expected to be temporary and reversible.
                  Since all platform locations within the high probability areas for the occurrence of historic and prehistoric
              archaeological resources are given archaeological clearance prior to setting the structure, removal of the










                   IV-246

                   structure should not result in any adverse impact to archaeological resources. This is consistent with the
                   findings of the Programmatic Environmental Assessment: Structure Removal Activities, Central and Western Gulf
                   of Merico Planning Areas (USDOI, MMS, 1987c).

                   Summary

                       The greatest potential impact to an historic archaeological resource as a result of the proposed action
                   would result from a contact between an OCS offshore activity (platform installation, drilling rig emplacement,
                   dredging or pipeline project) and an historic shipwreck. A recently completed, MMS-funded study (Garrison
                   et al., 1989) has resulted in the refinement of the high probability areas for the location of historic period
                   shipwrecks. A new NTL for archaeological resource surveys in the Gulf of Mexico Region (NTL 91-02) has
                   increased the survey linespacing density for historic shipwreck surveys from 150 in to 50 Fri.
                       Most other activities associated with the proposed action are expected to have very low impacts on historic
                   archaeological resources. No new onshore infrastructure construction or pipeline landfalls are expected as a
                   result of the proposed action. Historic cultural resources, therefore, will not be affected by these activities.
                   The chance of contact from an off spill associated with the proposed action is very low. Furthermore, the
                   major impact from an oil-spill contact on an historic coastal site, such as a fort or lighthouse, would be visual
                   due to oil contamination. These impacts would be temporary and reversible. Impacts from dredging are
                   expected to be low.
                       The OCS activity could contact a shipwreck because of incomplete knowledge on the I(xation of shipwrecks
                   in the Gulf. Although this occurrence is not probable, such an event would result in the disturbance or
                   destruction of important historic archaeological information. Other factors associated with the proposed action
                   are not expected to affect historic archaeological resources.

                   Conclusion


                       There is a very small possibility of an impact between OCS oil and gas activities and a historic shipwreck
                   or site. Should such an impact occur, unique or significant historic archaeological information could be lost.

                   Effects of the Base Case Without the Proposed Stipulation

                       The greatest impact to an historic cultural resource as a result of the proposed action would result from
                   a contact between an OCS offshore activity (platform installation, drilling rig emplacement, and pipeline
                   projects) and an historic shipwreck. The Archaeological Resource Stipulation, which is currently in place,
                   requires remote-sensing survey in areas designated to have a high probability for historic archaeological
                   resources. It should also be noted that a proposed new regulation under 30 CFR 250.25 will incorporate the
                   stipulation into operational regulations. The OCS Lands Act, as amended, states that a permit for geological
                   exploration shall be issued only if such exploration does not disturb any site, structure, or object of historical
                   or archaeological interest. As the only means to determine whether objects of historical or archaeological
                   interest would be impacted by geological exploration, the archaeological surveys that are required under the
                   current stipulation, would still be necessary to comply with the OCS Lands Act, as amended. The effects of
                   the impact-producing factors on historic archaeological resources without the Archaeological Resource
                   Stipulation would, therefore, remain the same as those when the stipulation is considered a part of the
                   proposed action.
                       The archaeological surveys under NTL 91-02, conducted prior to initiating oil and gas activities within a
                   lease block, are estimated to be 95 percent effective in locating historic shipwrecks in areas where sidescan
                   sonar is effective in identifying shipwrecks. In areas where sidescan sonar is ineffective because of thick
                   accumulations of sediment on the seafloor (these areas roughly account for 40% of the CIIA), magnetometer
                   data, which is estimated at being only 90 percent effective in locating ferrous objects at the 50-in survey line
                   spacing required in NTL 91-02, will be the only means to detect shipwrecks. A recently completed, MMS-
                   funded study (Garrison et al., 1989) has provided new data on shipwreck locations.










                                                                                                                             IV-247

                     Most other activities associated with the proposed action are not expected to affect historic archaeological
                resources. No new onshore infrastructure construction or pipeline landfalls are expected as a result of the
                proposed action. Historic cultural resources, therefore, will not be affected by these activities. The chances
                of contact from an off spill associated with the proposed action is very low. Furthermore, the impact from an
                off-spill contact on an historic coastal site, such as a fort or a lighthouse, would be visible due to oil
                contamination and would be temporary and reversible. Impacts from dredging directly attributable to OCS
                activities are considered to be low.
                     To summarize, because of incomplete knowledge on the location of shipwrecks in the Gulf, an OCS activity
                could contact a shipwreck. Although this occurrence is not probable, such an event would result in the
                disturbance or destruction of important historic archaeological information. Other factors associated with the
                proposed action are not expected to affect historic archaeological resources.

                High Case Ana4u&

                     Lease blocks with a high probability for the occurrence of prehistoric, prehistoric and historic, or historic
                archaeological resources may by found in the Central Gulf. Those blocks with a high probability for prehistoric
                archaeological resources may be found landward of a line that roughly follows the 45-m bathymetric contour.
                A Letter to Lessees (LTL) dated November 30, 1990, redefined the high probability areas for the presence of
                historic period shipwrecks. NTL 91-02, which changes survey methodology requirements for historic shipwreck
                surveys will become effective February 17, 1991. Section II.A-I.c.(3) presents a proposed stipulation as a
                potential mitigating measure for leases resulting from the proposed action, the impact analysis for which,
                including the Archaeological Resource Stipulation for analytical purposes, is presented below. It should also
                be noted that a proposed rulemaking creating an operational regulation to replace the archaeological
                stipulation has been issued.
                     Sections providing supportive material for the archaeological resources analysis include Sections III.C.5.
                (description of archaeological resources), IV.A.4.b. (offshore infrastructure), IV.A.5.a. (onshore infrastructure),
                and IV.C.3. (oil spills).
                     A number of OCS-related factors may cause adverse impacts to archaeological resources. Damage caused
                by the placement of drilling rigs, production platforms, pipelines, dredging, and anchoringcould destroy artifacts
                or disrupt the provenience and stratigraphic context of artifacts, sediments, and paleoindicators from which the
                scientific value of the archaeological resource is derived. Oil spills could destroy the ability to date prehistoric
                sites by radiocarbon dating techniques. Ile dredging of new channels and maintaining current channels could
                impact a historic shipwreck (Espey, Huston, & Associates, 1990). Ferromagnetic debris associated with OCS
                oil and gas activities would tend to mask magnetic signatures of significant historic archaeological resources.
                     The placement of drilling rigs and production platforms has the physical potential to impact prehistoric
                and/or historic archaeological resources. Pile driving associated with platform emplacement may also cause
                sediment liquefaction an unknown distance from the piling. Pipeline placement has the physical potential to
                impact prehistoric and/or historic archaeological resources. Anchoring associated with platform and pipeline
                emplacement, as well as service vessel and shuttle tanker activities, may also physically impact prehistoric
                and/or historic archaeological resources.
                     Maintenance dredging associated with the proposed action has the potential to impact an historic
                shipwreck. As a shipwreck may represent a unique historic archaeological resource, dredging may result in the
                damage or loss of significant or unique archaeological information. However, the frequency of impact related
                to the proposed action is extremely low.
                     Oil spills have the potential to impact both prehistoric (by contamination of organic materials, which have
                the potential to date site occupation through radiocarbon dating techniques) and historic archaeological
                resources (limited to visual impacts and physical impacts associated with spill cleanup operations).
                     The OCS oft and gas activities will also generate tons of ferromagnetic structures and debris, which will
                tend to mask magnetic signatures of significant historic archaeological resources.
                     According to Table IV-2, under the High Case, 1,060 exploration, delineation, and development wells will
                be drilled, and 50 production platforms and 400 km of pipelines will be installed in the Central Gulf. Of this
                number, 445 exploration, delineation, and development wells will be drilled and 24 platforms and 128 km of










                 IV-248

                 pipelines will be installed within Subareas C-1 and C-3, where the majority of -lease bk)cks with a high
                 probability for historic period shipwrecks are located. The recent MMS study (Garrison et al., 1989) and
                 concomitant LTL have redefined the high probability area for the occurrence of historic period shipwrecks.
                 The location of any proposed activity within a lease block that has a high probability for hLaoric shipwrecks
                 requires archaeological clearance prior to operations. Considering that the expanded database contains 273
                 shipwrecks in the entire Central Gulf OCS, the probability of an OCS activity contacting and damaging a
                 shipwreck is fairly low. If an oil and gas structure contacted an historic resource, there could be damage to
                 or loss of significant or unique archaeological information. The greater effectiveness of the survey in the
                 western part of the CPA would reduce the potential impact to historic shipwrecks.
                      Onshore historic properties include sites, structures, and objects such as historic buildings, lbrts, lighthouses,
                 homesteads, cemeteries, and battlefields. Development as a result of the proposed action could result in the
                 direct physical contact between the construction of new onshore facilities or pipeline canals and previously
                 unidentified historic sites. No new onshore facilities are projected to be constructed undet        - the High Case.
                 Because no land is projected to be disturbed, impacts to coastal historic properties in the CPA are not expected
                 to occur.
                      Should an off spill contact a coastal historic site, such as a fort or a lighthouse, the major impact would be
                 visual because of oil contamination of the site and its environment. This impact would k; expected to be
                 temporary and reversible.
                      Since all platform locations within the high probability areas for the occurrence of historic and prehistoric
                 archaeological resources are given archaeological clearance prior to setting the structure, removal of the
                 structure should not result in any adverse impact to archaeological resources. This is consistent with the
                 findings of the Programmatic Environmental Assessment: Shucture Removal Activities, Central and Western Gulf
                 of Merico Planning Areas (USDOI, MMS, 1987c).

                 Conclusion


                      Under the High Case scenario, there is a very small possibility of an impact between OCS oil and gas
                 activities and a historic shipwreck or site. Should such an impact occur, unique or significant historic
                 archaeological information could be lost.

                 (b) Prehistoric

                      Offshore development as a result of the proposed action could result in an interaction between a drilling
                 rig, a platform, a pipeline, dredging, or anchors and an inundated prehistoric site. This direct physical contact
                 with a site could destroy fragile artifacts or site features and could disturb artifact provenience and site
                 stratigraphy. The result would be the loss of archaeological data on prehistoric migrations, settlement patterns,
                 subsistence strategies, and archaeological contacts for North America, Central America, South America, and
                 the Caribbean.


                 Base Case Anaois

                      The archaeological surveys, coupled with archaeological analysis and clearance of proposed location of
                 operations, are estimated to be 90 percent effective in allowing identification and avoidance of high probability
                 areas for site occurrence. According to Table IV-2, under the Base Case, 590 exploration, delineation, and
                 development wells will be drilled, and 30 production platforms and 240 kin of pipelines will be installed in the
                 Central Gulf. In-house analysis by MMS shows it likely that some of these potential impacts will occur within
                 Subarea C-4, which has no potential for the occurrence of prehistoric archaeological sites. Removing Subarea
                 C-4 from the projected impacts resulting from the proposed action leaves 355 exploration, delineation, and
                 development wells; 21 production platforms; and 168 kin of pipelines installed (Table IV-2). The limited
                 amount of impact to the seafloor throughout the CPA, coupled with the effectiveness of the survey and
                 resulting archaeological clearance, is sufficient to assume a low potential for interaction bemeen an impact-










                                                                                                                             IV-249

                 producing factor and a prehistoric archaeological site. Should such an impact occur, damage to or loss of
                 significant or unique prehistoric archaeological information could occur.
                     Onshore prehistoric archaeological resources include sites, structures, and objects such as shell middens,
                 earth middens, campsites, kill sites, tool manufacturing areas, ceremonial complexes, and earthworks.
                 Currently, unidentified onshore prehistoric sites would have to be assessed after discovery to determine the
                 uniqueness or significance of the information that they contain. Sites already listed in the National Register
                 of Historic Places and those considered eligible for the Register have already been evaluated as having the
                 potential for making a unique or significant contribution to science. Of the unidentified coastal prehistoric sites
                 that could be impacted by onshore development, some may contain unique information.
                     Onshore development as a result of the proposed action could result in direct physical contact between
                 construction of new onshore facilities or a pipeline landfall and a previously unidentified prehistoric site. This
                 direct physical contact with a prehistoric site could destroy fragile artifacts or site features and could disturb
                 the site context. The result would be the loss of information on the prehistory of North America and the Gulf
                 Coast Region. No new onshore facilities or pipeline landfalls, however, are projected for the Base Case as a
                 result of proposed Sale 142. There should, therefore, be no impact to onshore CPA prehistoric sites from
                 onshore development
                     Should an oil spill contact a coastal prehistoric site, the potential for dating the site using C-14 could be
                 destroyed. This loss of information might be ameliorated by ceramic or lithic seriation or other relative dating
                 techniques. Previously unrecorded coastal sites could also experience an impact from oil-spill cleanup
                 operations. Cleanup equipment could destroy fragile artifacts or site features and could disturb the site context.
                 The result would be the loss of information on the prehistory of North America and the Gulf Coast Region.
                 Some of the coastal prehistoric sites that might be impacted by beach cleanup operations may contain unique
                 information. In coastal Louisiana, prehistoric sites occur frequently along the barrier islands and mainland
                 coast and the margins of bays and bayous. Thus, any spill that contacts the land would involve a potential
                 impact to a prehistoric site. The probability of a spill greater than or equal to 1,000 bbl occurring and
                 contacting within 10 days the CPA coast within 10 days is 2 percent (Table IV-21). Based on this low
                 probability, the assumption is that no spills greater than or equal to 1,000 bbl will affect prehistoric
                 archaeological resources. Furthermore, it is assumed that no spill of greater than 50 and less than 1,000 bbl
                 will occur and contact the coastline during the 35-year life of the proposed action. A few spills greater than
                 1 and less than or equal to 50 bbl are estimated to contact the coast during the lease life. By the time these
                 spills contact the shore, however, there likely would not be enough oil to cover an exposed shell midden or
                 other site to the extent that a large percentage of the organic remains in the site would be contaminated.
                     All platform locations within the high probability areas for the occurrence of historic and prehistoric
                 archaeological resources are given archaeological clearance prior to setting the structure; removal of the
                 structure should not result in any adverse impact to archaeological resources. This is consistent with finding
                 of the Programmatic Environmental Assessment: Structural Removal Activities, Central and Western Gulf of
                 Merico Planning Areas (USDOI, MMS, 1987c).

                 Summary
                     Several impact-producing factors may threaten the prehistoric archaeological resources of the Central Gulf.
                 An impact could result from a contact between an OCS activity (pipeline and platform installations, drilling
                 rig emplacement and operation, dredging, and anchoring activities) and a prehistoric site located on the
                 continental shelf. The archaeological surveys and archaeological clearance of sites that are required prior to
                 an operator beginning oil and gas activities in a lease block are estimated to be 90 percent effective at
                 identifying possible prehistoric sites. Since the survey and clearance provide a significant reduction in the
                 potential for a damaging interaction between an impact-producing factor and a prehistoric site, there is a very
                 small possibility of an OCS activity contacting a prehistoric site. Should such contact occur, there could be
                 damage to or loss of significant or unique archaeological information.
                      Onshore development as a result of the proposed action could result in the direct physical contact from
                 new facility construction, pipeline trenching, and new navigation canal dredging. None of these activities is
                 expected to occur under the Base Case.











                 IV-250

                     Should an oil spill contact a coastal prehistoric site, the potential for dating the site using radiocarbon
                 methods could be destroyed. Oil-spill cleanup operations could physically impact coastal prehistoric sites.
                 Previously unrecorded sites could also experience an impact from oil-spill cleanup operations on beaches. The
                 probability of an spill greater than or equal to 1,000 bbl occurring and contacting within 10 days a coastal
                 prehistoric site within 10 days is very low (2%), and it is assumed that no contact will oamr. A few spills
                 greater than 1 and less than or equal to 50 bbl are assumed to contact the coast, but these small spills would
                 probably not cover an exposed site, such as a shell midden, with enough oil to contaminate all the datable
                 organic remains.

                 Conclusion


                     There is a very small possibility of an impact between OCS oil and gas activities and a prehistoric
                 archaeological site. Should such an impact occur, there could be damage to or loss of significant or unique
                 prehistoric archaeological information.

                 Effects of the Base Case Without the Proposed Stipulation

                     Several impact-producing factors may threaten the prehistoric archaeological resources ol'the Central Gulf.
                 An impact could result from a contact between an OCS activity (pipeline and platform installations, drilling
                 rig emplacement and operation, and anchoring activities) and a prehistoric site located on the continental shelf.
                 The Archaeological Resource Stipulation, which is considered part of the proposed action, requires remote-
                 sensing surveys in areas designated to have a high probability for prehistoric archaeological resources. It should
                 also be noted that a proposed new regulation under 30 CFR 250.25 will incorporate the stipulation into
                 operational regulations. The OCS Lands Act, as amended, states that a permit for geological. exploration shall
                 be issued only if such exploration does not disturb any site, structure, or object of historical or archaeological
                 interest. As the only means to determine whether objects of historical or archaeological interest would be
                 impacted by geological exploration, the archaeological surveys that are required under the current stipulation
                 would still be necessary to comply with the OCS Lands Act, as amended. The effects of the impact-producing
                 factors on prehistoric archaeological resources without the Archaeological Resource Stipulation in place would,
                 therefore, remain the same as those when the stipulation is considered part of the proposed action.
                     The archaeological surveys that are required prior to an operator beginning oil and gas activities in a lease
                 block are estimated to be 90 percent effective in identifying possible prehistoric sites. The survey provides a
                 significant reduction in the potential for a damaging interaction between an impact-producing factor and a
                 prehistoric site.
                     Should such an impact occur, there could be damage to or loss of significant or unique prehistoric
                 archaeological information.
                     Onshore development as a result of the proposed action could result in the direct physical[ contact between
                 new facility construction, pipeline trenching, and navigation canal dredging. None of these activities are
                 expected to occur under the Base Case.
                     Should an oil spill contact a coastal prehistoric site, the potential for dating the site using radiocarbon
                 methods could be destroyed. Previously unrecorded sites could also experience an impact front oil-spill cleanup
                 operations on beaches. The probability of a spill greater than or equal to 1,000 bbl occurring and contacting
                 within 10 days a coastal prehistoric site is very low, and it is assumed that no contact will occur. A few spills
                 greater than 1 and less than or equal to 50 bbl are assumed to contact the coast, but these small spills would
                 not cover an exposed site, such as a shell midden, with enough oil to contaminate all the dateable organic
                 remains.


                 High Case Analysis

                     The higher level of offshore development projected for the High Case would increase the potential for an
                 interaction between an impact-producing factor and a prehistoric site. Should an interaction occur, the
                 potential exists for the loss of significant or unique archaeological information.










                                                                                                                          IV-251

                    Offshore development as a result of the proposed action could result in an interaction between a drilling
               rig, a platform, a pipeline, dredging, or anchors and an inundated prehistoric site. This direct physical contact
               with a site could destroy fragile artifacts or site features and could disturb artifact provenience and site
               stratigraphy. The result would be the loss of archaeological data on prehistoric migrations, settlement patterns,
               subsistence strategies, and archaeological contacts for North America, Central America, South America, and
               the Caribbean.
                    Likely locations for archaeological sites can be delineated with high-resolution seismic data. As the high
               probability zone for the occurrence of prehistoric sites on the OCS approximates the 45-m bathymetric contour,
               Subarea C4, which is deeper than 45 m in its entirety, is assumed to have no potential for the occurrence of
               these sites.
                    The archaeological surveys, coupled with archaeological analysis and clearance of proposed location of
               operations, are estimated to be 90 percent effective in allowing identification and avoidance of high probability
               areas for site occurrence. According to Table IV-2, under the High Case, 1,060 exploration, delineation, and
               development wells will be drilled, and 50 production platforms and 400 kin of pipelines will be installed in the
               Central Gulf. Removing Subarea C4 from the projected impacts resulting from the High Case leaves 630
               exploration, delineation, and development wells, 33 production platforms; and 264 kin of pipelines installed
               (Table IV-2). The limited amount of impact to the seafloor throughout the CPA, coupled with the
               effectiveness of the survey and resulting archaeological clearance, is sufficient to assume a low potential for
               interaction between an impact-producing factor and a prehistoric archaeological site.
                    Onshore development is not expected as a result of the High Case scenario for proposed Sale 142.
               Because no land is projected to be disturbed, there are no expected impacts from onshore development as a
               result of the proposed action.
                    Should an oil spill contact a coastal prehistoric site, the potential for dating the site using C-14 could be
               destroyed.     Previously unrecorded coastal sites could also experience an impact from oil-spill cleanup
               operations, which could destroy fragile artifacts or site features and disturb the site context. The result would
               be the loss of information on the prehistory of North America and the Gulf Coast Region. In coastal
               Louisiana, prehistoric sites occur frequently along the barrier islands and mainland coast and the margins of
               bays and bayous. Thus, any spill that contacts the land would involve a potential impact to a prehistoric site.
               The probability of a spill greater than or equal to 1,000 bbl occurring and contacting within 10 days the CPA
               coast within 10 days is 4 percent (Table IV-21). Based on this low probability, the assumption is that no spills
               greater than or equal to 1,000 bbl will affect prehistoric archaeological resources. Furthermore, it is estimated
               that no spill of greater than 50 and less than 1,000 bbl will occur and contact the coastline during the 35-year
               life of the proposed action. A few spills greater than 1 and less than or equal to 50 bbl are estimated to
               contact the coast during the lease life. By the time these spills contact the shore, however, there likely would
               not be enough oil to cover an exposed shell midden or other site to the extent that a large percentage of the
               organic remains in the site would be contaminated.
                    All platform locations within the high probability areas for the occurrence of historic and prehistoric
               archaeological resources are given archaeological clearance prior to setting the structure; removal of the
               structure should not result in any adverse impact to archaeological resources. This is consistent with finding
               of the Programmatic Environmental Assessment: Structural Removal Activities, Central and Western Gulf of
               Merico, Planning Areas (USDOI, MMS, 1987c).

               Conclusion

                    Under the High Case scenario, there is a very small possibility of an impact between OCS oil and gas
               activities and a prehistoric archaeological site. Should such an impact occur, there could be damage to or loss
               of significant or unique prehistoric archaeological information.










                 IV-252

                 (12) Impacts on Socioeconomic Conditions

                 (a) Population, Labor, and Employment

                     The importance of the oil and gas industry to the coastal communities of the Gulf of Mvdco is significant,
                 particularly in Louisiana and eastern Texas. Dramatic changes in the level of OCS oil and gas activity over
                 recent years have brought forth similar fluctuations in population, labor, and employment in the Gulf of Mexico
                 region. State government and citizen concern over the Gulf Coast's economic dependence on the oil and gas
                 industry has made clear the need for an analysis of the impact of the OCS program on the social and economic
                 well-being of affected communities.
                     This section focuses on an analysis of the direct, indirect, and induced impacts of the OCS oil and gas
                 industry on the population, labor, and employment of the counties and parishes within the coastal impact area
                 of the Central and Western Gulf Region caused by the proposed action in the Central Gulf. There would also
                 be other economic impacts, both direct and indirect, associated with the proposed actions because of their
                 effect on other industries, such as commercial fishing, tourism, and recreational fishing. The direct benefit or
                 loss in these industries is addressed in the sections of this EIS related specifically to those topics. The OCS
                 program's indirect and induced effect on these associated industries is much more difficult to quantify.
                 Nevertheless, it will generally constitute a fraction of the magnitude of the direct impact
                     Section          provides an historical perspective of the oil and gas industry, as well as a brief description
                 of recent events that have significantly affected the level of OCS activity in the Gulf of Mexico. A detailed
                 discussion of historical trends in population, labor, and employment within the coastal impact area of the
                 Central and Western Gulf can be found in Section III.C.2. Included in that section is a listing of counties and
                 parishes in the Central and Western Gulf of Mexico coastal impact area, as well as current suaistics and future
                 projections of population, labor, and employment levels for coastal subareas in the region. These projections
                 will serve as a baseline against which impacts will be measured.
                     The methodology developed to quantify these impacts on population, labor, and employment takes into
                 account changes in OCS-related employment, along with population and labor impacts resulting from these
                 employment changes within each individual coastal subarea. For analysis purposes, the projections of OCS-
                 related employment are classified into three categories: direct, indirect, and induced employment.
                     Direct employment associated with the oil and gas industry consists of those workers involved in oil and
                 gas exploration, development, and production operations, including geophysical and seistitiograph surveys,
                 exploratory drilling, well operation, maintenance, and other contract support services. These activities are
                 covered under the Standard Industrial Classification (SIC) Code 13--Oil and Gas Extraction. To facilitate the
                 analysis, several assumptions were made regarding the employment associated with SIC 13 activity projected
                 to result from the proposed action. These assumptions are estimates of typical leveh, of activity and
                 employment based on historical observations:


                         Exploration Activity -        One rig can drill an average of nine wells per year with
                                                       approximately 133 workers.

                         Development Activity -        One platform rig can drill an average of six wells per year with
                                                       a crew of approximately 115 workers.

                         Production Activity -         One offshore platform can operate with an average crew of 28
                                                       workers.

                     A population and employment computer model developed at MMS uses these and other assumptions to
                 translate estimates of exploration, development, and production activities associated with the proposed action
                 into annual projections of direct employment for each planning area. Planning area level employment
                 projections are apportioned to offshore subareas on the basis of each offshore subarea's hydrocarbon resource










                                                                                                                          IV-253

                 potential and projected share of the offshore infrastructure. Employment within each offshore subarea is then
                 allocated to coastal subareas on the basis of an allocation matrix developed at MMS. This matrix allocates
                 direct employment offshore to those coastal subareas where the onshore support facilities for that particular
                 offshore site are expected to be located. The matrix was derived from an analysis of the historical and
                 proposed location of onshore support facilities for the different actual or planned drilling sites offshore. The
                 allocation matrix also accounts for the fact that employment impacts from offshore activity are not constrained
                 by planning area or subarea boundaries. In other words, oil and gas development in the WPA can and does
                 impact the coastal communities of the Central Gulf and vice versa.
                     Indirect employment resulting from activities in the primary oil and gas extraction industry occurs in
                 secondary or supporting oil- and gas-related industries. Section III.C.2. provides a listing of those industries
                 considered in the projection of indirect employment. Employment in the Sanitary Service Industry, which
                 supports oil-spill clean-up activities (SIC 4959), was not included as part of indirect employment in the model
                 because the manpower requirements for off-spill clean-up activities are highly unpredictable. The level of
                 employment involved in any given clean-up effort is influenced by a variety of factors, such as whether or not
                 the oil comes ashore, the coastal formation, weather conditions at the time of the incident, type and quantity
                 of oil spilled, as well as the extent and duration of the oiling. Nevertheless, employment in oil-spill clean-up
                 activities has been included in the Base Case analysis as an external adjustment to the population and
                 employment model, using assumptions regarding the size of potential oil spills presented in Section IV.C.
                     Based on an analysis of actual industry-specific employment levels in the counties and parishes of the
                 coastal impact area, a multiplier was determined to estimate indirect employment from direct employment
                 projections for the oil and gas extraction industry. The indirect employment multiplier determined for this
                 analysis was 0.67.
                     Induced employment in tertiary industries is generated from both direct and indirect employment and
                 consists of jobs that are created or supported by the expenditures of employees in primary and secondary
                 industries. Induced employment results from the demand for consumer goods and services such as food,
                 clothing, housing, and entertainment. Based on a previous MMS analysis of employment impacts, the induced
                 employment multiplier for this analysis was estimated to be 0.33.
                     The total employment impact to each coastal subarea because of the proposed action is the sum of its
                 direct, indirect, and induced employment impact projections. The population dependent on the income from
                 oil- and gas-related employment for their subsistence was derived from total employment estimates based on
                 an analysis of the historic ratio of population to employment in the coastal subareas. Labor impacts were
                 addressed using both population and employment data to assess the supply and demand for workers trained
                 in oil- and gas-related trades.
                     To arrive at a bottom-Me level of impact for population, labor, and employment, the population and
                 employment model is used to convert the projections to a format that facilitates analysis and comparison. This
                 conversion involves the estimation of annual changes in population, labor, and employment projections for the
                 proposed action as a percent of the population, labor, and employment levels expected in absence of the
                 proposal for each coastal subarea. To derive population and employment levels in absence of the proposal,
                 the population and employment impacts estimated for the proposed actions were subtracted from a set of
                 baseline projections that, inherently, included impacts from the proposal. The baseline projections of
                 population and employment used in the analysis are described in Section III.C.2. Because these baseline
                 projections assume the continuation of existing social, economic, and technological trends, they also include
                 employment resulting from the continuation of current patterns in OCS leasing activity.

                 Base Case Ana4uis

                     Baseline employment projections for the coastal impact area of the Central and Western Gulf can be found
                 in Figure IV-8. Displayed also on this figure are baseline employment projections excluding jobs generated
                 by the proposed action in the Central Gulf. The methodology discussion preceding this Base Case analysis
                 provides a description of these projections. A total of approximately 58,500 person-years of employment
                 (direct, indirect, and induced) are required in the Central and Western Gulf coastal subareas in support of the
                 proposed sale in the Central Gulf throughout its 35-year life. Less than 2 percent of the total employment
                         I









                  IV-254


                              2,600,000                   A. Central Planning Area

                                                                Baseline Projection       Mhout Pro posal


                              2,400,000




                              2,200,000




                              2,000,000




                              1,800,000




                              1,600,000
                                          P


                                                                            Year
                                                         B. Western Planning Area
                              5,000,000
                                                              Baseline Projection      Without Proposal


                              4,500,000  -




                              4,000,000



                         115
                              3,500,000




                              3,000,000



                              2,500,000
                                                    N
                                                                                        4, 4 4 4               CV& C?
                                                                           Yew


                      Due to the very low impact of the proposed action on employment, the projections graphed on the figure may appear to overlap.


                  Figure IV-8. Base Case Employment Impacts from Central Gulf Sale 142 (USDOI,
                                 MMS, Gulf of Mexico OCS Region estimates, 1991).











                                                                                                                              IV-255

                 resulting from the proposed action is expected to affect the coastal subareas of the Western Gulf. Peak-year
                 impacts occur in 1999, with a total'of approximately 2,750 workers involved in primary, secondary, and tertiary
                 industries. Direct employment in the primary oil and gas extraction industry (SIC 13) accounts for 45 percent
                 of the total employment impact projected for the coastal subareas of the Central and Western Gulf over the
                 life of the proposed action. Exploratory activities, which occur during the first 11 years of the life of the
                 proposed action, are the main contributor to peak-year direct and total employment impacts. After their initial
                 peak in 1999, total employment impacts begin to decline as oil and gas exploration is reduced in areas leased
                 under the proposed action. Peak employment impacts resulting from development activities take place soon
                 after exploratory activities reach their peak, but are much less intense. A second, smaller total employment
                 peak impact is experienced in the years 2011 and 2012, as employment resulting from production activities
                 offshore is reaching its peak. Even though exploratory activities drive peak-year employment impacts, the
                 greatest contributor to overall employment impacts is production operations. Employment in oil and gas
                 production activities accounts for approximately 60 percent of total direct employment impacts due to
                 production in the Central Gulf. Indirect and induced employment impacts in secondary and tertiary industries
                 amount to approximately 30 percent and 25 percent, respectively, of the total employment impacts over the
                 life of the proposed action in the Central Gulf.
                     Table IV-27 displays the model projections of total OCS-related employment impacts (direct, indirect, and
                 induced) from proposed Sale 142 in the Central Gulf to the coastal subareas of the CPA and WPA throughout
                 the life of the proposed action. Table IV-28 provides estimates of annual impacts to the population and
                 employment of each coastal subarea as a percent of levels expected in absence of the proposal. These impact
                 estimates represent changes in the new share of the existing population and employment that will be dependent
                 on the OCS off and gas industry for support as a result of the proposed action. These impact estimates alone
                 do not provide enough information to determine whether employment needs will be met with the population
                 and labor force in the area or with immigrants and new labor force from other areas.
                     The greatest impact to employment is expected in coastal Subareas C-1 and C-2, with peak year impact
                 estimates for 1998 of 0.24 percent and 0.23 percent, respectively. Coastal Subareas C-1 and C-2 collectively
                 provide over 67 percent of the total employment required in support of the proposed action in the Central
                 Gulf. Coastal Subarea C-3 contributes approximately 27 percent of the employment The least impacted
                 coastal subarea in the CPA is C-4, accounting for only 4 percent of the employment projected for the proposal
                 in the coastal impact area. Only coastal Subarea W-2 in the Western Gulf is affected by the proposed action
                 in the CPA. The Western Gulf is expected to provide under 2 percent of total employment for proposed Sale
                 142 in the Central Gulf.
                     Employment impacts resulting from oil-spill clean-up activities, because of their highly unpredictable nature,
                 were handled apart from the population and employment model. The level of employment associated with
                 any given clean-up operation is dependent on numerous variables which, in themselves, are also difficult to
                 predict. Nevertheless, the most labor-intensive clean-up operations are those from spills that contact the
                 coastline, particularly recreational beaches. For the purpose of this analysis, it is assumed that only those spills
                 contacting land will involve significant manpower requirements in their clean-up efforts. Based on employment
                 statistics from recent spill clean-up operations along the coast, the assumption is that, for every kilometer of
                 coastline subjected to heavy offing, approximately 100 temporary workers will be employed for a maximum of
                 6 weeks.
                     Section IV.C. presents estimates of the mean number of offshore spins assumed to result from the
                 proposed action in the CPA. The probability that one or more offshore spills greater than or equal to 1,000
                 bbI will occur and contact land within 10 days of the accident is 2 percent (Table IV-21). Based on the low
                 probability of an offshore spill this size occurring and contacting land, the assumption is that no significant
                 employment requirements will result from the clean-up of offshore spills of this size category in the Base Case.
                 One spill of the size category greater than 50 bbl and less than 1,000 bbl is assumed to occur (Table IV-2);
                 however, it is not assumed to contact the coastline (Section MCA.). T\venty-one small spills of the size
                 category greater than 1 bbI and less than or equal to 50 bbl are assumed to occur in the CPA over the fife of
                 the proposed action. Of these 21 spills, only a few are estimated to contact land. Furthermore, employment
                 impacts resulting from the clean-up of spills this small would be negligible.










                   IV-256














                                                                         Table IV-27

                                        Base Case OCS-Related Employment Projections (Direct+Indirect+lnduced)
                                                                    Central Gulf Sale 142
                                                                        (person-years)


                   YEAR               W1           W2            Cl            C2          C3            C4           WGOM*      CGOM-


                   1993                     0             0             0           0             0            0             0            0
                   1994                     0             2           37            72           46            7             2          162
                   1995                     0           10          178          336           212           32            10           757
                   1996                     0           21          382          721           457           69            21         1629
                   1997                     0           26          456          864           549           03            26         1953
                   1998                     0           35          613         1154           732           ill           35         2609
                   1999                     0           37          645         1205           765           116           37         2731
                   2000                     0           35          611         1132           713           108           35         2564
                   2001                     0           33          568         1040           655           99            33         2362
                   2002                     0           33          542          974           613           92            33         2221
                   2003                     0           33          536          954           601           90            33         2181
                   2004                     0           31          493          862           542           81            31         1979
                   2005                     0           33          504          868           546           82            33         2000
                   2006                     0           28          421          705           448           67            28         1641
                   2007                     0           31          453          757           481           72            31         1763
                   2008                     0           32          469          783           498           75            32         1824
                   2009                     0           34          501          835           531           80            34         1947
                   2010                     0           35          517          861           548           82            35         2008
                   2011                     0           37          549          912           581           87            37         2130
                   2012                     0           37          549          912           581           87            37         2130
                   2013                     0           36          516          844           540           81            36         1981
                   2014                     0           36          516          844           540           81            36         1981
                   2015                     0           37          532          870           557           83            37         2042
                   2016                     0           36          516          844           540           81            36         1981
                   2017                     0           35          500          818           524           78            35         1920
                   2018                     0           31          434          698           449           67            31         1648
                   2019                     0           30          418          672           433           65            30         1587
                   2020                     0           29          402          646           416           62            29         1526
                   2021                     0           27          386          620           400           60            27         1465
                   2022                     0           26          370          595           383           57            26         1404
                   2023                     0           24          337          543           350           52            24         1282
                   2024                     0           19          273          439           283           42            19         1038
                   2025                     0           14          193          310           200           30            14           733
                   2026                     0             7           96         155           100           15              7          366
                   2027                     0             0             0           0             0            0             0            0


                                            0           948        14512        24846        15814          2375          948        57547



                      Western Gulf of Mexico.
                      Central Gulf of Mexico.

                   Source: USDOI, RMS, Gulf of Mexico OCS Region estimates, 1991.











                                                                                                                               IV-257















                                                                       Table IV-2 8


                                        Population and Employment Impact Levels for the Base Case Scenario
                                                                 Central Gulf Sale 142
                                                                       1percent-)



                  EMPLOYMENT IMPACT LEVELS:                                      POPULATION IMPACT LEVELS:

                  YEAR     W1       W2      Cl       C2       C3       C4        YEAR     W1      W2       Cl       C2        C3     C4


                  1993     0.00t    0.00%   0.00%    0.00%    0.00%    0.00%     1993     0.00%  0.00%    0.00%   0.00%   0.00%   0.00%
                  1994     0.00%    0.00%   0.01%    0.01%    0.011    0.00%     1994     0.00%  0.00%    0.02%   0.02%   0.01%   0.00%
                  1995     0.00%    0.00%   0.07%    0.07%    0.03%    0.01%     1995     0.00%  0.001    0.07%   0.07%   0.03%   0.01%
                  1996     0.001    0.00%   0.15%    0.151    0.07%    0.02%     1996     0.00%  0.00%    0.15%   0.15%   0.07%   0.02%
                  1997     0.00%    0.00%   0.17%    0.17%    0.08%    0.02%     1997     0.00%  0.00%    0.18%   0.18%   0.08%   0.02%
                  1998     0.00%    0.00%   0.23%    0.23%    0.11%    0.03%     1998     0.00%  0.00%    0.24%   0.23%   0.11%   0.03%
                  1999     0.00%    0.00%   0.24%    0.23%    0.11%    0.03%     1999     0.00%  0.00%    0.25%   0.24%   0.12%   0.03%
                  2000     0.00%    0.00%   0.22%    0.22%    0.10%    0.02%     2000     0.00%  0.00%    0.24%   0.23%   0.11%   0.03%
                  2001     0.00%    0.00%   0.21%    0.20%    0.09%    0.02%     2001     0.00%  0.00%    0.22%   0.21%   0.101   0.02%
                  2002     0.00%    0.00%   0.19%    0.18%    0.09%    0.02%     2002     0.00%  0.00%    0.21%   0.19%   0.09%   0.02%
                  2003     0.00%    0.00%   0.19%    0.18%    0.08%    0.02%     2003     0.00%  0.00%    0.21%   0.19%   0.09%   0.02%
                  2004     0.00%    0.00%   0.17%    0.16%    0.07%    0.02%     2004     0.00%  0.00%    0.19%   0.17%   0.08%   0.02%
                  2005     0.00%    0.00%   0.18%    0.16%    0.07%    0.02%     2005     0.00%  0.00%    0.19%   0.17%   0.08%   0.02%
                  2006     0.00%    0.00%   0.14%    0.13%    0.06%    0.01%     2006     0.00%  0.00%    0.16%   0.13%   0.07%   0.02%
                  2007     0.00%    0.00%   0.15%    0.13%    0.06%    0.02%     2007     0.00%  0.00%    0.17%   0.14%   0.07%   0.02%
                  2008     0.00%    0.00%   0.16%    0.14%    0.07%    0.02%     2008     0.00%  0.00%    0.17%   0.15%   0.07%   0.02%
                  2009     0.00%    0.00%   0.17%    0.14%    0.07%    0.02%     2009     0.00%  0.00%    0.19%   0.16%   0.08%   0.02%
                  2010     0.001    0.001   0.17%    0.15%    0.07%    0.02%     2010     0.00%  0.00%    0.19%   0.16%   0.08%   0.02%
                  2011     0.00%    0.00%   0.18%    0.16%    0.07%    0.02%     2011     0.00%  0.00%    0.20%   0.17%   0.08%   0.02%
                  2012     0.00%    0.00%   0.18%    0.15%    0.07%    0.02%     2012     0.00%  0.00%    0.20%   0.17%   0.08%   0.02%
                  2013     0.00%    0.00%   0.17%    0.14%    0.07%    0.02%     2013     0.00%  0.001    0.19%   0.15%   0.08*   0.02%
                  2014     0.00%    0.00%   0.16%    0.14%    0.07%    0.02%     2014     0.00%  0.00%    0.19%   0.15%   0.08%   0.02%
                  2015     0.00%    0.00%   0.17%    0.14%    0.07%    0.02%     2015     0.00%  0.00%    0.19%   0.15%   0.08%   0.02%
                  2016     0.00%    0.00%   0.16%    0.14%    0.06%    0.02%     2016     0.00%  0.00%    0.181   0.15%   0.08%   0.02%
                  2017     0.00%    0.00%   0.15%    0.13%    0.06%    0.02%     2017     0.00%  0.00%    0.18%   0.14%   0.07%   0.02%
                  2018     0.00%    0.00%   0.13%    0.111    0.05%    0.01%     2018     0.00%  0.00%    0.15%   0.12%   0.06%   0.01%
                  2019     0.00%    0.00%   0.13%    0.11%    0.05%    0.01%     2019     0.00%  0.00%    0.15%   0.12%   0.06%   0.01%
                  2020     0.00%    0.00%   0.12%    0.10%    0.05%    0.01%     2020     0.00%  0.00%    0.14%   0.11%   0.06%   0.01%
                  2021     0.00%    0.001   0.11%    0.10%    0.05%    0.01%     2021     0.00%  0.00%    0.13%   0.11%   0.05%   0.01%
                  2022     0.00%    0.00%   0.11%    0.09%    0.04%    0.01%     2022     0.00%  0.00%    0.131   0.10%   0.05%   0.01%
                  2023     0.00%    0.00%   0.10%    0.08%    0.04%    0.01%     2023     0.00%  0.001    0.12%   0.09%   0.05%   0.01%
                  2024     0.00%    0.00%   0.08%    0.07%    0.03%    0.01%     2024     0.00%  0.00%    0.09%   0.07%   0.04%   0.01%
                  2025     0.00%    0.00%   0.06%    0.05%    0.02%    0.01%     2025     0.00%  0.00%    0.07%   0.05%   0.03%   0.01%
                  2026     0.00%    0.00%   0.03%    0.02%    0.01%    0.00%     2026     0.00%  0.00%    0.03%   0.03%   0.01%   0.00%
                  2027     0.00%    0.00%   0.00%    0.00%    0.00%    0.00%     2027     0.00%  0.00%    0.00%   0.00%   0.001   0.00%

                   Note:   Impact levels represent the percent change in population or employment due     to the  proposal with respect
                           to total levels expected in absence of the proposal.

                  Source: USDOI, MMS, Gulf of Mexico OCS Region estimates, 1991.










                 IV-258

                      In addition to the offshore spills referenced above, a number of small onshore spills are expected to occur
                 (Table IV4). The level of cleanup action associated with spins this size win be minimal.
                      The greatest impact on population from activities associated with Sale 142 is expected in coastal Subareas
                 C-1 and C-2 with peak-year estimates for 1999 of 0.25 and 0.24 percent, respectively (Table IV-28). The
                 coastal communities of the Western Gulf have no noticeable peak population impacts.
                      The level of OCS-related employment expected to result from the proposed action in the Central Gulf is
                 not significant enough to attract new residents and labor force to the area. Analysis of historical trends has
                 shown that only population impacts greater than I percent typically involve positive net migration to any given
                 area. None of the coastal subareas is projected to experience population impacts greater than I percent
                 because of the proposed action. Labor force impacts will parallel population and employment impacts. Jobs
                 are expected to be filled by currently unemployed or underemployed workers or by future entrants into the
                 labor force already living in the area. Therefore, employment demands in support of the proposed action win
                 be met with the existing population and available labor force.

                 Summaq

                      Peak annual changes in the population, labor, and employment of all coastal subareas hi the Central and
                 Western Gulf resulting from the proposed action in the Central Gulf represent less than 1 percent of the levels
                 expected in absence of the proposal in the Central Gulf. Only 2 percent of the total employment resulting
                 from the proposed action is expected to affect the coastal subareas of the Western Gulf. Employment resulting
                 from oil-spill clean-up activities due to the proposed action is negligible. It is expected that employment
                 demands in support of the proposed action will be met with the existing population and available labor force.

                 Conclusion


                      The Base Case impact of the proposed action in the Central Gulf on the popuLation, labor, and
                 employment of the counties and parishes of the Central and Western Gulf coastal impact area is expected to
                 be less than 1 percent of the levels expected in the absence of the proposal.

                 High Case Ana4uis

                      Population, labor, and employment impacts resulting from the proposed action in the High Case are less
                 than twice as high as those expected in the Base Case. A total of approximately 101,100 person-years of
                 employment (direct, indirect, and induced) are required in the Central and Western Gulf coastal subareas in
                 support of the proposed action for the High Case. Peak-year impacts occur in 1999 with approximately 4,350
                 workers involved in primary, secondary, and tertiary industries. Direct employment in the primary oil and gas
                 extraction industry (SIC 13) accounts for 45 percent of the total employment impact projected for the coastal
                 subareas of the Central and Western Gulf over the life of the proposed action. Exploratory activities, which
                 occur during the first 12 years of the life of the proposed action, are the main contributor to peak-year direct
                 and total employment impacts. After their initial peak in 1999, total employment impacts begin to decline as
                 oil and gas exploration is reduced in areas leased under the proposed action. Peak employment impacts
                 resulting from development activities take place soon after exploratory activities reach their peak, but are much
                 less intense. A second, smaller total employment peak impact is experienced in the year 2015, when
                 employment resulting from production activities offshore reaches its peak. Even though exploratory activities
                 drive peak-year employment impacts, the greatest contributor to overall employment impacts Iror the High Case
                 is production operations. Employment in oil and gas production activities accounts for approxh-nately 57 percent
                 of total direct employment impacts resulting from production in the Central Gulf. Indirect and induced
                 employment impacts in secondary and tertiary industries amount to approximately 30 and 25 percent,
                 respectively, of the total employment impacts over the life of the proposed action in the Central Gulf.
                      Table IV-29 displays the model projections of total OCS-related employment impacts (direct, indirect, and
                 induced) from Sale 142 in the Central Gulf to the coastal subareas of the CPA and WPA throughout the life
                 of the proposed action in the High Case. Table IV-30 provides estimates of annual impacts to the population










                                                                                                                                 IV-259















                                                                       Table IV-29

                                      High Case OCS-Related Employment Projections (Direct+Indirect+Induced)
                                                                  Central Gulf Sale 142
                                                                     (person-years)


                 YEAR               wl           W2            Cl            C2           C3          C4           WGOM.       CGOM.*


                 1993                      0            0            0             0            0            0            0             0
                 1994                      0            4           76         146            89           13             4          324
                 1995                      0          19          355          677           420           64           19          1515
                 1996                      0          33          612         1166           723          109           33          2610
                 1997                      0          47          862         1645          1018          154           47          3679
                 1998                      0          54          982         1869          1160          176           54          4187
                 1999                      0          56          1014        1922          1201          182           56          4318
                 2000                      0          56          1002        1896          1188          180           56          4265
                 2001                      0          51          909         1709          1080          164           51          3862
                 2002                      0          52          906         1694          1080          163           52          3844
                 2003                      0          44          749         1388           897          136           44          3169
                 2004                      0          43          717         1320           861          130           43          3029
                 2005                      0          43          715         1305           861          130           43          3011
                 2006                      0          44          729         1331           879          133           44          3072
                 2007                      0          47          773         1410           932          141           47          3256
                 2008                      0          48          788         1436           950          144           48          3318
                 2009                      0          52          847         1540          1021          154           52          3563
                 2010                      0          51          827         1498           999          151           51          3475
                 2011                      0          54          886         1603          1070          162           54          3720
                 2012                      0          54          886         1603          1070          162           54          3720
                 2013                      0          56          915         1655          1105          167           56          3842
                 2014                      0          56          915         1655          1105          167           56          3842
                 2015                      0          57          930         1681          1123          170           57          3904
                 2016                      0          56          915         1655          1105          167           56          3842
                 2017                      0          54          886         1603          1070          162           54          3720
                 2018                      0          47          758         1363           918          139           47          3177
                 2019                      0          40          631         1123           765          116           40          2634
                 2020                      0          38          601         1070           730          110           38          2512
                 2021                      0          36          572         1018           694          105           36          2389
                 2022                      0          35          543          966           659           99           35          2267
                 2023                      0          32          499          see           605           91           32          2083
                 2024                      0          26          411          731           498           75           26          1715
                 2025                      0          19          293          522           356           54           19          1225
                 2026                      0            9         147          261           178           27             9           613
                 2027                      0            0            0             0            0            0            0             0


                                           0         1415         23648       43349         28412         4295         1415        99704


                     Western Gulf of Mexico.
                     Central Gulf of Mexico.

                 Source: USDOI, MMS, Gulf of Mexico OCS Region estimates, 1991.









                     IV-260














                                                                                   Table IV-30

                                                Population and Employment Impact Levels for the High Case Scenario
                                                                            Central Gulf Sale 142
                                                                                   (percent-)



                     EMPLOYMENT IMPACT LEVELS:                                                 POPULATION IMPACT LEVELS:

                     YEAR       W1        W2        Cl        C2         C3        C4          YEAR      W1        W2        Cl         C2         C3      C4


                     1993       0.00%    0.00%      0.00%    0.00%      0.00%      0.001       1993     0.00%     0.00%     0.00%    0.00%    0.001     0.00%
                     1994       0.00%    0.00%      0.03%    0.03%      0.01%      0.0016      1994     0.00%     0.00%     0.03%    0.03%    0.01%     0.00%
                     1995       0.00%    0.00%      0.14%    0.14%      0.06%      0.02%       1995     0.00%     0.00%     0.14%    0.141    0.06%     0.02%
                     1996       0.00%    0.00%      0.24%    0.24%      0.11%      0.03%       1996     0.00%     0.00%     0.24%    0.24%    0.11%     0.03%
                     1997       0.00%    0.00%      0.33%    0.33%      0.15%      0.04%       1997     0.00%     0.00%     0.34%    0.34%    0.16%     0.04%
                     1998       0.00%    0.00%      0.37%    0.37%      0.17%      0.04%       1998     0.00%     0.00%     0.391    0.38%    0.18%     0.04%
                     1999       0.00%    0.00%      0.38%    0.37%      0.17%      0.041       1999     0.00%     0.00%     0.40%    0.39%    0.18%     0.04%
                     2000       0.00%    0.00%      0.37%    0.36%      0.17%      0.04%       2000     0.00%     0.00%     0.39%    0.38%    0.18%     0.04%
                     2001       0.00%    0.00%      0.33%    0.32%      0.15%      0.04%       2001     0.00%     0.00%     0.35%    0.34%    0.16%     0.04%
                     2002       0.00%    0.00%      0.32%    0.321      0.15%      0.04%       2002     0.00%     0.00%     0.35%    0.3.3%   0.16%     0.04%
                     2003       0.00%    0.00%      0.27%    0.26%      0.12%      0.03%       2003     0.00%     0.00%     0.29%    0.27%    0.13%     0.03%
                     2004       0.00%    0.00%      0.25%    0.24t      0.12%      0.03%       2004     0.00%     0.00%     0.27%    0.25%    0.13%     0.03%
                     2005       0.00%    0.00%      0.25%    0.24%      0.12%      0.03%       2005     0.00%     0.00%     0.27%    0.25%    0.13%     0.03%
                     2006       0.00%    0.00%      0.25%    0.24%      0.12%      0.03%       2006     0.00%     0.00%     0.28%    0.25%    0.13%     0.03%
                     2007       0.00%    0.00%      0.26%    0.25%      0.12%      0.03%       2007     0.00%     0.00%     0.29%    0.27%    0.14%     0.03%
                     2008       0.00%    0.00%      0.27%    0.25%      0.12%      0.03%       2008     0.00%     0.00%     0.29%    0.27%    0.14%     0.03%
                     2009       0.00%    0.00%      0.28%    0.27%      0.13%      0.03%       2009     0.00%     0.00%     0.31%    0.29%    0.15%     0.04%
                     2010       0.00%    0.00%      0.27%    0.26%      0.13%      0.03%       2010     0.00%     0.00%     0.31%    0.28%    0.14%     0.03%
                     2011       0.00%    0.00%      0.29%    0.27%      0.14%      0.03%       2011     0.00%     0.00%     0.33%    0.29%    0.15%     0.04%
                     2012       0.00%    0.00%      0.29%    0.27%      0.13%      0.03%       2012     0.00%     0.00%     0.32%    0.29%    0.15%     0.04%
                     2013       0.00%    0.00%      0.29%    0.28%      0.14%      0.03%       2013     0.00%     0.00%     0.33%    0.3.0%   0.16%     0.04%
                     2014       0.00%    0.00%      0.29%    0.27%      0.14%      0.03%       2014     0.00%     0.00%     0.33%    0.3.0%   0.16%     0.04%
                     2015       0.00%    0.00%      0.29%    0.27%      0.14%      0.03%       2015     0.00%     0.00%     0.33%    0.3.0%   0.16%     0.04%
                     2016       0.001    0.00%      0.29%    0.27%      0.13%      0.03%       2016     0.00%     0.00%     0.33%    0.29%    0.15%     0.04%
                     2017       0.00%    0.00%      0.27%    0.26%      0.13%      0.03%       2017     0.00%     0.00%     0.32%    0.28%    0.15%     0.04%
                     2018       0.00%    0.00%      0.23%    0.22%      0.11%      0.03%       2018     0.00%     0.00%     0.27%    0.24%    0.13%     0.03%
                     2019       0.00%    0.00%      0.19%    0.18%      0.09%      0.02%       2019     0.00%     0.00%     0.22%    0.1.9%   0.11%     0.031
                     2020       0.00%    0.00%      0.18%    0.17%      0.08%      0.02%       2020     0.00%     0.00%     0.21%    0.1.8%   0.10%     0.02%
                     2021       0.00%    0.00%      0.17%    0.16%      0.08%      0.02%       2021     0.00%     0.00%     0.20%    0.1.7%   0.09%     0.02%
                     2022       0.00%    0.00%      0.161    0.15%      0.07%      0.02%       2022     0.00%     0.00%     0.19%    0.1.6%   0.09%     0.02%
                     2023       0.00%    0.00%      0.15%    0.13%      0.07%      0.02%       2023     0.00%     0.00%     0.17%    0.3.5%   0.08%     0.02%
                     2024       0.00%    0.00%      0.12%    0.11%      0.06%      0.01%       2024     0.00%     0.00%     0.14%    0.1.2%   0.07%     0.02%
                     2025       0.00%    0.00%      0.08%    0.08%      0.04%      0.01%       2025     0.00%     0.00%     0.10%    0.09%    0.05%     0.01%
                     2026       0.00%    0.00%      0.04%    0.04%      0.02%      0.00%       2026     0.00%     0.00%     0.05%    0.04%    0.02%     0.01%
                     2027       0.00%    0.00%      0.00%    0.001      0.00%      0.00%       2027     0.00%     0.00%     0.00%    0.00%    0.001     0.00%

                       Note:    Impact levels represent the percent change in population or employment due                  to the   proposal with    respect
                                to total levels expected in absence of the proposal.

                     Source: USDOI, MMS, Gulf of Mexico OCS Region estimates, 1991.










                                                                                                                             IV-261

                and employment of each coastal subarea as a percent of levels expected in absence of the proposal. These
                impact estimates represent changes in the new share of the existing population and employment that will be
                dependent on the OCS off and gas industry for support as a result of the proposed action. These impact
                estimates alone do not provide enough information to determine whether employment needs will be met with
                the existing population and labor force in the area or with immigrants and new labor force from other areas.
                    The greatest impact to employment in the High Case is expected in coastal Subareas C-1 and C-2, with
                peak year impact estimates for 1999 of 0.38 percent and 0.37 percent, respectively. Coastal Subareas C-1 and
                C-2 collectively provide over 66 percent of the total employment required in support of the proposed action
                in the Central Gulf. Coastal Subarea C-3 contributes approximately 28 percent of the total employment
                impacts to the Central and Western Gulf coastal impact area. The least impacted coastal subarea in the CPA
                is C-4, accounting for only 4 percent of the total employment impact from Sale 142. Only coastal Subarea
                W-2 in the Western Gulf is affected by the proposed action in the CPA- The Western Gulf is expected to
                provide slightly under 2 percent of total employment for Sale 142 in the Central Gulf.
                    Employment impacts resulting from oil-spill clean-up activities, because of their highly unpredictable nature,
                were handled apart from the population and employment model. The level of employment associated with
                any given clean-up operation is dependent on numerous variables which, in themselves, are also difficult to
                predict Nevertheless, the most labor-intensive clean-up operations are those from spills that contact the
                coastline, particularly recreational beaches. For the purpose of this analysis, it is assumed that only those spills
                contacting land will involve significant manpower requirements in their clean-up efforts. Based on employment
                statistics from recent spill clean-up operations along the coast, the assumption is that, for every kilometer of
                coastline subjected to heavy offing, approximately 100 temporary workers will be employed for a maximum of
                6 weeks.
                    Section IV.C. presents estimates of the mean number of offshore spills assumed to result from the
                proposed action for the High Case in the CPA. The probability that one or more offshore spills of 1,000 bbl
                or greater will occur and contact land within 10 days of the accident is 4 percent (Table IV-21). In addition
                to the offshore spills referenced above, a number of small onshore spills are expected to occur. The level of
                clean-up action associated with spills this size will be minimal (Table IV-4). Based on the low probability of
                a spill this size occurring and contacting land, the assumption is that no significant employment requirements
                will result from the clean-up of offshore spills of this size category in the High Case. Two spills of the size
                category greater than 50 bbl and less than 1,000 bbl are assumed to occur (Table IV-2); however, it is not
                expected that they will contact the coastline (Section IV.C.1.). Forty-seven spills of the size category greater
                than 1 bbI and less than or equal to 50 bbl are assumed to occur in the CPA over the life of the proposed
                action. Of these 47 spills, only a few are estimated to contact land (Section IV.C.1.). Furthermore,
                employment impacts resulting from the clean-up of spills this small are expected to be negligible.
                    In addition to the offshore spills referenced above, a number of small onshore spills are expected to occur
                (Table IV-4). The level of cleanup action associated with spills this size will be minimal.
                    The greatest impact on population from activities associated with Sale 142 in the High Case is expected
                in coastal Subareas C-1 and C-2 with peak-year impact estimates for 1999 of 0.40 and 0.39 percent, respectively
                (Table IV-30). The coastal communities of the Western Gulf have no noticeable peak population impacts.
                    The level of OCS-related employment expected to result from the proposed action for the High Case in
                the Central Gulf is less than twice as large as that estimated for the Base Case. However, it is still not
                significant enough to attract new residents and labor force to the area. Analysis of historical trends has shown
                that only population impacts greater than 1 percent typically involve positive net migration to any given area.
                None of the coastal subareas is projected to experience population impacts greater than 1 percent as a result
                of the proposed action in the High Case. Labor force impacts will parallel population and employment
                impacts. Jobs are expected to be filled by currently unemployed or underemployed workers or by future
                entrants into the labor force already living in the area. Therefore, employment demands in support of the
                proposed action for the High Case in the Central Gulf will be met with the existing population and available
                labor force.










                 IV-262

                 Summary

                     Peak annual changes in the population, labor, and employment of all coastal subareas iri the Central and
                 Western Gulf resulting from the proposed action in the Central Gulf for the High Case represent less than 1
                 percent of the levels expected in absence of the proposal. The coastal communities of the Western Gulf are
                 expected to support slightly over 1 percent of the total employment generated by the CA-.ntral Gulf Sale.
                 Employment resulting from oil spill clean-up activities due to the proposed action is negligible. It is expected
                 that employment demands in support of the proposed action will be met with the existing population and
                 available labor force.


                 Conclusion


                     The High Case impact of the proposed action in the Central Gulf on the popuhation, labor, and
                 employment of the counties and parishes of the Central and Western Gulf coastal impact area is expected to
                 be less than 1 percent of the levels expected in the absence of the proposal.

                 (b) Public Services and Infrasnucture

                     Public services and infrastructure, as used in this analysis, include commonly provided public, semipublic,
                 and private services and facilities, such as education, police and fire protection, sewage treatment, soud-waste
                 disposal, water supply, recreation, transportation, health care, other utilities, and housing. Changes in demands
                 for and usage of public services and infrastructure could result from OCS activities. Adverse effects could arise
                 if the amount or rate of increase or decrease in the usage significantly exceeded or fell far bellow the capability
                 of a local area to provide a satisfactory level of service.
                     Sections providing supportive material for this analysis include Sections III.C.2. (description of
                 socioeconomic issues), IV.A.2. (offshore infrastructure), IV.A.3. (onshore infrastructure), IVC. 1. and IV.C.3.
                 (oil spills), and IV.D.La.(12)(a) (impacts on population, labor, and employment).
                     For the purpose of this analysis, OCS-related, impact-producing factors to public services and community
                 infrastructure will include work force fluctuations, migration (both in-migration and out-migration), and the
                 effect of relative income. These impact-producing factors are interrelated and derive from or result in
                 increased population. It should be noted that these impact-producing factors also pertain to social patterns
                 and will be analyzed in Section IV.D.La.(12)(c).

                 Base Case Ana4uis

                     Baseline employment projections and information relating to the model analysis used to arrive at these
                 projections are presented in Section IV.D.La.(12)(a). This information is incorporated by reference.
                 Unexpected events (such as the 1973 Arab Oil Embargo) may influence oil and gas activity within the Gulf of
                 Mexico Region. These events cannot be projected and cannot be presumed for this analysii.
                     Approximately 58,495 person-years of employment (direct, indirect, and induced) are required to sustain
                 the proposed action throughout its 35-year life (Table IV-27). Less than 2 percent of toud employment in
                 support of the proposed action is expected to affect the Western Gulf coastal subareas (Subarea W-2). The
                 remaining employment is expected to lie within coastal Subareas C-1 (25%), C-2 (42%), C-3 (27%), and C-4
                 (4%). In the peak year of 1999, approximately 2,768 person-years of total employment will be required to
                 support the proposed action. The greatest amount of this employment is expected to Ue within Subarea C-2.
                 A comparison between the expected population and employment impacts for the coastal subareas as a result
                 of the proposed action compared to expected population and employment without the proposal is shown in
                 Table IV-30. The greatest impact to employment is expected to occur in coastal Subareas C-1 and C-2, with
                 peak-year impact estimates in 1999 of 0.24 and 0.23 percent, respectively.
                     A major impact of OCS-generated activities, new population associated with increased @service demands,
                 will be significantly mitigated by planning and other measures undertaken at the Federal, Swte, regional, and










                                                                                                                            IV-263

                 local levels. All the potential onshore development areas either have or participate in local and/or regional
                 planning programs. The objectives of these programs include orderly and efficient growth management that
                 minimizes fiscal, social, and environmental impacts. This analysis assumes that future Federal, State, and local
                 management efforts will be effective at avoiding or mitigating many potential adverse effects on the quality of
                 public services and infrastructure that might occur as a result of the kinds of planned, long-term economic
                 growth and development anticipated by the local and regional planning community.
                    Short-term fluctuations in the work force as a result of changing levels of OCS-related oil and gas activity
                 could impact social services and community infrastructure in several ways. Large, short-term layoffs of on and
                 gas industry personnel could stress the abilities (both in terms of work load and available funding) of public
                 and private agencies whose mission is to aid persons with severe financial difficulties. Ile need for public or
                 private assistance could force the diversion of funds needed for the maintenance of community infrastructure,
                 such as schools and roads. Large, short-term increases in the work force could result in net positive migration
                 and cause a scarcity of housing, a shortage of municipal personnel (i.e., policemen, firemen, engineers, etc.),
                 and an increase in the cost of living. A comparison with Table IV-28 reveals that there are no significant
                 differences expected in population and employment between the proposed action and the levels expected
                 without the proposal in coastal Subareas W-1 and W-2. None of the CPA coastal subareas is expected to
                 experience population impacts greater than 0.25 percent (1999-peak year) as a result of the proposed action.
                 It is expected that employment related to the proposed action will not require importation of labor and that
                 the existing labor pool will be adequate to supply labor needs (Section IV.D.I.a.(12)(a)). The proposed action
                 is expected to provide jobs for unemployed, underemployed, and new employees already living in the area.
                 Excess labor capacity of the coastal subareas is expected to provide sufficient human resources to maintain
                 adequate levels of public services and infrastructure.
                     Migration into a coastal subarea (in-migration) as a response to increased levels of OCS-related oil and
                 gas activity could result in increased stress on both public and private agencies in assisting newly relocated
                 persons and in providing basic services to an expanding population. In addition, not all persons who migrate
                 to an area seeking employment will find it. This failure causes additional stress on social service agencies. In-
                 migration into an area may result in dramatic population increases, stressing on community schools, roads, law
                 enforcement agencies, and other community infrastructure. Migration out of a coastal subarea (out-migration)
                 in response to lowered levels of OCS-related oil and gas activity could jeopardize secondary and tertiary jobs
                 that were created during periods of increased population, stressing social service agencies. Community
                 infrastructure created in response to a larger population could become a redundant expense as a result of out-
                 migration. An analysis of historical trends indicates that population impacts of greater than 1 percent involve
                 positive net migration into a given area. Table IV-28 indicates that population impacts are not expected to
                 exceed this figure under the Base Case. Therefore, it is expected that the proposed action will not produce
                 in-migration into the coastal subareas of the Gulf of Mexico. The proposed action will result in the need for
                 approximately 58,495 person-years of total employment throughout its 35-year fife. These jobs are expected
                 to be filled by unemployed, underemployed, and newly employed persons already living in the area. By
                 providing these jobs, the proposed action will reduce the amount of out-migration comparative to that which
                 might occur without the proposal.
                     The relatively high wages paid to OCS-related oil and gas industry personnel could result in an increase
                 in population from in-migration and a concomitant increase in the local cost of living. Impacts to social services
                 could come from the need for assistance of those living on fixed incomes, as well as those unemployed as a
                 result of the decline of businesses unable to operate in an environment of high wage scale. Impacts to
                 community infrastructure could come from the defection of community workers from infrastructure-related
                 activities to higher paying jobs in the oil and gas industry. The employment needs of the proposed action are
                 not expected to exceed the labor capacity of the Gulf coastal subareas. As mentioned above, an analysis of
                 historical trends indicates that in-migration should not be expected as a result of the proposed action. In
                 addition, jobs created by the proposal would likely reduce the amount of migration out of the coastal subareas
                 when compared to scenarios without the proposal. It is expected that employees leaving public service and
                 infrastructure-based jobs could be replaced by the existing labor pool and area residents entering the job
                 market Revenues generated by Federal, State, and local taxes from employment related to the proposed
                 action are expected to mitigate increased needs for public services generated by the proposed action.










                 IV-264

                 Summary

                     Impacts to public services and infrastructure would be related to dramatic, short-term POPulation increases
                 or decreases, which are not projected as a result of the proposed action. Specific impact-producing factors
                 examined in this analysis include work force fluctuations, migration into or out of the coastal subareas, and the
                 relatively high wages made by personnel involved in the oil and gas industry. An analysis of historical trends
                 indicates that population impacts of greater than I percent involve positive net migration into a given area.
                 Under the Base Case, population impacts are not expected to exceed the peak year impacts of 0.25 percent.
                 No positive net migration into the coastal subareas of the Central and Western Gulf is exlwcted to occur as
                 a result of the proposed action. It is expected that employment needs will be met by those currently employed
                 in the oil and gas industry as well as the unemployed and underemployed, and new employees already living
                 in the area. In addition, jobs created by the proposal would likely reduce the amount of migration out of the
                 coastal subareas when compared to scenarios without the proposal. It is expected that employees leaving
                 public service and infrastructure-related jobs could be replaced from the existing labor pool.

                 Conclusion


                     Population and employment impacts that result from the proposed action under the Base Case scenario
                 will not result in disruptions to community infrastructure and public services beyond what is anticipated by in-
                 place planning and development agencies.

                 High Case Ana4uis

                     Baseline employment projections and information relating to the model analysis used to arrive at these
                 projections are presented in Section IV.D.l.a.(12)(a). This information is incorporated by reference.
                 Unexpected events (such as the 1973 Arab Oil Embargo) may influence off and gas activity within the Gulf of
                 Mexico Region. These events cannot be projected and cannot be presumed for this analysis..
                    Approximately 101,119 person-years of employment (direct, indirect, and induced) are required to sustain
                 the proposed action in the High Case throughout its 35-year life (Table IV-29). Less than 2 percent of total
                 employment in support of the High Case is expected to affect the Western Gulf coastal subareas (Subarea W-
                 2). The remaining employment is expected to lie within coastal Subareas C-1 (23%), C-2 (43%), C-3 (28%),
                 and C4 (4%). In the peak year of 1999, approximately 4,374 person-years of total employment are required
                 to support the High Case. The greatest amount of this employment is expected to lie within Subarea C-2. A
                 comparison between the expected population and employment impacts for the coastal subareas as a result of
                 the High Case and the expected population and employment without the proposal may be seen in Table IV-30.
                 The greatest impact to employment is expected to occur in coastal Subareas C-1 and C-2 with peak-year impact
                 estimates in 1999 of 0.38 and 0.37 percent, respectively.
                    A major impact of OCS-generated activities, new population associated with increased service demands,
                 will be significantly mitigated by planning and other measures undertaken at the Federal, State, regional, and
                 local levels. All of the potential onshore development areas either have or participate in local and/or regional
                 planning programs, which have objectives that include orderly and efficient growth management that minimizes
                 fiscal, social, and environmental impacts. This analysis assumes that future Federal, State, and local
                 management efforts will be effective at avoiding or mitigating many potential adverse effects on the quality of
                 public services and infrastructure, effects that might occur as a result of the kinds of planned, long-term
                 economic growth and development anticipated by the local and regional planning community.
                    Short-term fluctuations in the work force as a result of changing levels of OCS-related oil and gas activity
                 could impact social services and community infrastructure in several ways. Large, short-term layoffs of oil and
                 gas industry personnel could stress the abilities (both in terms of work load and available funding) of public
                 and private agencies whose mission is to aid persons with severe financial difficulties. The need for public or
                 private assistance could force the diversion of funds needed for the maintenance of community infrastructure,
                 such as schools and roads. Large, short-term increases in the work force could result in net positive migration
                 and cause a scarcity of housing, a shortage of municipal personnel (i.e., policemen, firemen, engineers, etc.),









                                                                                                                         IV-265

                and an increase in the cost of living. A comparison with Table IV-30 reveals that there are no significant
                differences in population and employment between the proposed action and the levels expected without the
                proposal in coastal Subareas W-1 and W-2. None of the CPA coastal subareas is expected to experience
                population impacts greater than 0.40 percent (1999-peak year) as a result of the High Case. It is expected that
                employment related to the High Case will not require importation of labor and that the existing labor pool will
                be adequate to supply labor needs. The proposal under the High Case is expected to provide jobs for the
                unemployed and the underemployed, and new employees already living in the area. Excess labor capacity of
                the coastal subareas is expected to provide sufficient human resources to maintain adequate levels of public
                services and infrastructure (Section IVD.La.(12)(a)).
                   Migration into a coastal subarea (in-migration) as a response to increased levels of OCS-related oil and
                gas activity could result in increased stress on both public and private agencies in assisting newly relocated
                persons and in providing basic services to an expanding population. In addition, not all persons who migrate
                to an area seeking employment will find it, causing additional stress on social service agencies. In-migration
                may result in dramatic increases in population, producing stress on community schools, roads, law enforcement
                agencies, and other community infrastructure. Migration out of a coastal subarea (out-migration) in response
                to lowered levels of OCS-related oil and gas activity could jeopardize secondary and tertiary jobs that were
                created during periods of increased population, stressing social service agencies. Community infrastructure
                created in response to a larger population could become a redundant expense as a result of out-migration.
                An analysis of historical trends indicates that population impacts of greater than 1 percent involve positive net
                migration into a given area. Table IV-30 indicates that population impacts are not expected to exceed this
                figure under the High Case. It is therefore expected that the proposal under the High Case will not produce
                in-migration into the coastal subareas of the Gulf of Mexico. The High Case will result in the need for
                approximately 101,119 person-years of total employment throughout the 35-year life of the proposed action.
                These jobs are expected to be filled by the unemployed and the underemployed, and newly employed persons
                already living in the area. By providing these jobs, the High Case will reduce the amount of out-migration
                compared to that which might occur without the proposal.
                    The relatively high wages paid to OCS-related oil and gas industry personnel could result in a population
                increase from in-migration and a concomitant increase in the local cost of living. Impacts to social services
                could come from the need for assistance of those living on fixed incomes, as well as those unemployed as a
                result of the decline of businesses unable to operate in an environment of high wage scale. Impacts to
                community infrastructure could come from the defection of community workers from infrastructure-related
                activities to higher paying jobs in the oil and gas industry. The employment needs of the High Case are not
                expected to exceed the labor capacity of the Gulf coastal subareas. As mentioned above, an analysis of
                historical trends indicates that in-migration should not be expected as a result of the High Case. In addition,
                jobs created by the proposal would likely reduce the amount of migration out of the coastal subareas when
                compared to scenarios without the proposal. It is expected that employees leaving public service and
                infrastructure-based jobs could be replaced by the existing labor pool and area residents entering the job
                market. Revenues generated by Federal, State, and local taxes from employment related to the High Case are
                expected to mitigate any increased needs for public services generated by the proposal.
                    Impacts to public services and infrastructure would be related to dramatic short-term population increases
                or decreases, which are not projected as a result of the proposed action. Specific impact-producing factors
                examined in this analysis include work force fluctuations, migration into or out of the coastal subareas, and the
                relatively high wages made by personnel involved in the oil and gas industry. An analysis of historical trends
                indicates that population impacts of greater than 1 percent involve positive net migration into a given area.
                Under the High Case, population impacts are not expected to exceed the peak-year impacts of 0.40 percent.
                No positive net migration into the coastal subareas of the Central and Western Gulf is expected to occur as
                a result of the proposal. It is expected that employment needs will be met by those currently employed in the
                oil and gas industry as well as the unemployed and the underemployed, and new employees already living in
                the area. In addition, jobs created by the proposal would likely reduce the amount of migration out of the
                coastal subareas when compared with scenarios without the proposal. It is expected that employees leaving
                public service and infrastructure-related jobs could be replaced from the existing labor pool.










                 IV-266


                 Conclusion


                     Population and employment impacts that result from the proposed action under the High Case scenario
                 will not result in disruptions to community infrastructure and public services beyond what is anticipated by in-
                 place planning and development agencies.

                 (C) Social PaUenu

                     This impact analysis includes the coastal parishes and counties of the Central and Western Gulf of Mexico
                 (Section III.C.2.(a)). Social patterns, as used in this analysis, include traditional occupationss, folkways, social
                 structure, language, family life, and other forms of cultural adaptation to the natural and human environment
                 It should be noted that impacts unrelated to OCS oil and gas activity (such as technological improvements in
                 communications and transportation) have caused, and will continue to cause, changes within the analysis area.
                 However, the present analysis will consider only the effects of OCS-rclated oil and gas activity on the social
                 patterns of the Central and Western Gulf coastal subareas.
                     Sections providing supportive material for this analysis include Sections III.C.3. (description of
                 socioeconomic issues), IV.A.2. (offshore infrastructure), IV.C. 1. and IV.C.3. (oil spills), IV.D.l.a.(l)(b) (impacts
                 on sensitive coastal environments), IV.D.l.a.(9) (impacts on commercial fisheries), IV.D.La.(12)(a) (impacts
                 on population, labor, and employment), and IV.D.La.(12)(b) (impacts on public services and infrastructure).
                     For the purpose of this analysis, OCS-rclated impact-producing factors to social patterns will include work
                 force fluctuations, net migration (both in-migration and out-migration), work scheduling, displacement from
                 traditional occupations, and relative income. Many of these impact-producing factors result in or derive from
                 population growth. Adverse effects to social patterns could arise if disruption of social patterns occurred and
                 resulted in changes in traditional occupations, disruption in the viability of extant subcultures, and detrimental
                 effects on family life. As mentioned in Section III.C.2.c., it may be argued that employment in the oil and gas
                 industry could be perceived as a traditional occupation; however, for the purpose of this analysis, employment
                 in OCS-related oil and gas activity will not be considered a traditional occupation.

                 Base Case Ana4uis

                     Baseline employment projections and information relating to the model analysis used to arrive at these
                 projections are presented in Section IVDA.a.(12)(a). This information is incorporated by reference.
                 Unexpected events (such as the 1973 Arab Oil Embargo) may influence oil and gas activity ort the OCS within
                 the Gulf of Mexico Region. These events cannot be projected and cannot be presumed for this analysis.
                     The proposed action will result in approximately 58,500 person-years of employment (direct, indirect, and
                 induced) throughout its 35-ycar life (Table IV-27). Less than 2 percent of total employment in support of the
                 proposed action is expected to affect the Western Gulf coastal subareas (Subarea W-2). The remaining
                 employment is expected to lie within coastal Subareas C-1 (25%), C-2 (42%), C-3 (27%), and C-4 (4%). In
                 the peak year of 1999, approximately 2,768 person-years of total employment are required to support the
                 proposed action. The greatest amount is expected to lie within Subarea C-2. A comparison between the
                 expected population and employment impacts for the coastal subareas as a result of the proposed action and
                 the expected population and employment without the proposal is shown in Figure IV-10 and in Table IV-30.
                 The greatest impact to employment is expected to occur in coastal Subareas C-1 and C-2, with peak-year
                 impact estimates in 1999 of 0.24 and 0.23 percent, respectively.
                     Short-term fluctuations in the work force as a result of changing levels of activities could affect social
                 patterns in several ways. Large amounts of short-term layoffs in oil and gas industry personnel could result
                 in large numbers of persons returning to traditional ways of employment (i.e., fishing, trapping, farming, etc.),
                 stressing the various resources that would be exploited. A large increase in the hiring of oil and gas industry
                 personnel could attract persons engaged in traditional occupations, leaving fewer persons in them in the coastal
                 subareas and, perhaps, resulting in the loss of traditional knowledge associated with these occupations.










                                                                                                                              IV-267

                     The potential effects of work force fluctuations on extant subcultures in the coastal subareas are expected
                 to be greatest when large changes in OCS-related activity result in net positive or negative migration. The
                 quality of family life, in pertinent individual cases, could be adversely affected from the decrease of family
                 income and loss of security resulting from layoffs in the OCS oil and gas industry. The expected impacts on
                 family life, in pertinent individual cases, from increased hiring in the OCS-related off and gas industry would
                 be decreased monetary stress and an increased financial security. Problems related to work scheduling may
                 arise and are discussed below. As mentioned above, employment impacts under the proposed action are not
                 expected to exceed 0.24 percent in the peak year of 1999. Projected employment associated with the proposed
                 action is expected to come from those already employed in OCS-related activities and from the unemployed
                 and underemployed, and new employees already living in the coastal subareas. It is expected that the proposed
                 action will not result in large increases or decreases in OCS-related employment within the Central and
                 Western Gulf coastal subareas.
                     Both in-migration and out-migration could adversely effect social patterns in the Central and Western Gulf
                 coastal subareas. Expected adverse effects of in-migration include the loss of cultural homogeneity, the loss
                 of community cohesion, and changes in the quality of life with possible associated stresses to social patterns.
                 Expected adverse effects of out-migration include stress placed on family life by the departure of extended
                 family members; the departure of persons who are engaged, part-time, in traditional occupations; and impacts
                 to community cohesion by the departure of long-time residents. Projected population impacts in the Central
                 and Western Gulf coastal subareas are not expected to exceed 0.25 percent (1999-peak year). An analysis of
                 historical trends indicates that only population impacts greater than 1 percent typically involve positive net
                 migration into a given area. None of the coastal subareas is projected to experience population impacts greater
                 than 1 percent as a result of the proposed action. Employment in support of the proposed action is expected
                 to come from those currently employed in OCS-related oil and gas activities as well as the unemployed and
                 underemployed, and new employees already living in the area. It is assumed that employment as a result of
                 the proposal will decrease the amount of out-migration compared to that which would occur without the
                 proposal.
                     Distance to site and type of transportation needed for personnel in OCS-related off and gas activities results
                 in the normal work schedule occurring as a large block of time on duty (or at site) followed by a large block
                 of time off duty. The schedules may range from 7 days on followed by 7 days off to a 30 day-on/30-day off
                 schedule. It has been argued that this type of schedule has allowed for the participation in, and continuance
                 of, traditional occupations (Hallowell, 1979; Laska, personal comm., 1991). It is expected that stress will be
                 placed on family life in response to the regular absences of a parent (usually the father). In some cases, it is
                 expected that adaptation to changing family roles will occur. In other cases, however, it is expected that
                 adaptation will not occur and that deleterious impacts to family life, in pertinent individual cases, will occur.
                 In the peak-year of 1999, approximately 2,768 person-years of total employment are required to support the
                 proposed action. Many of those employed will be working in secondary and tertiary jobs and will not encounter
                 the extended work schedule mentioned above. Impacts to family life are expected to be serious in some
                 individual cases.
                      Displacement from traditional occupations could originate from destruction of a resource base, space-use
                 conflict, and voluntary shifts from traditional occupations to employment in OCS-related activities. Adverse
                 effects resulting from displacement from traditional occupations could include a diminishment in the number
                 of participants in traditional occupations, the loss of traditional knowledge and cultural heritage, and deleterious
                 impacts to family life. Space-use conflicts have been discussed in Section IV.D.l.a.(9). The existence of the
                 Fisherman's Contingency Fund mitigates, to some extent, space-use conflicts associated with commercial fishing.
                 A total of 239 claims was filed in 1990 and $212,453.24 were paid to persons attributing damage to OCS-related
                 debris. According to Sections IV.D.La.(l)(b) and IV.D.2.a.(l)(b), the proposed action is expected to have a
                 very low impact on coastal wetlands in both the CPA and WPA. It is therefore assumed that very little
                 displacement from traditional occupations will occur as a result of OCS-related destruction of wetlands. As
                 mentioned above, the extended work schedule associated with many OCS-related jobs may allow for continued
                 participation in traditional occupations. It is expected that relatively few persons will be displaced from
                 traditional occupations as a result of the proposed action.










                 IV-268

                     The relatively high wages paid to OCS-related oil and gas industry personnel can result in the voluntary
                 shift of persons engaged in traditional occupations to more lucrative positions within the oil and gas industry.
                 Dependency on these relatively high wages may have deleterious impacts on family life, particularly if layoffs
                 occur and the wage-earner cannot find work at comparable pay. It is assumed that some persons engaged in
                 lower-paying traditional occupations will seek employment in OCS-related oil and gas activities. Thoseengaged
                 in extended work schedules will retain the ability to participate in traditional occupations on a part-time basis.
                 Employment projections for the life of the proposed action indicate that peak year employment (1999) Will
                 total approximately 2,768 persons throughout the Central and Western Gulf coastal subareas. It is expected
                 that employment will come from persons already working in OCS-related oil and gas activities as well as the
                 unemployed and underemployed, and new employees already living in the area. The relatively small amount
                 of employment associated with the proposed action, in comparison with total employment in the Central and
                 Western Gulf, lessens the potential impact of relative wages on social patterns.

                 Summary

                     Impacts to social patterns would be related to dramatic changes in population and ite disruption of
                 environmental resources, as well as conditions inherent to OCS-related employment (i.e., work scheduling and
                 rate of pay). Specific impact-producing factors examined in this analysis include work force fluctuations,
                 migration into or out of the coastal subareas, work scheduling, displacement from traditional occupations, and
                 relative income. An analysis of historical trends indicates that population impacts of greater than 1 percent
                 typically involve positive net migration into a given area. Under the Base Case, population impacts are not
                 expected to exceed the peak-year impact of 0.25 percent. No positive net migration into Central and Western
                 Gulf coastal subareas is expected to occur as a result of the proposal. It is expected that employment will
                 occur from those currently employed in the oil and gas industry, as well as the unemployed and. underemployed,
                 and new employees already living in the area. It is expected that jobs created by the proposal would likely
                 reduce the amount of out-migration when compared to scenarios without the proposal and that minor
                 displacement from traditional occupations will occur as a result of the proposed action. This displacement win
                 be mitigated, to some extent, by the extended work schedule associated with OCS-related employment.
                 However, the extended work schedule is expected to have some deleterious effects on family life in some
                 individual cases. Impacts caused by the displacement of traditional occupations and relative wages are expected
                 to occur to a minimal extenL


                 Conclusion

                    It is expected that no net migration will occur as a result of the proposed action. Deleterious impacts to
                 social patterns are expected to occur in some individual cases as a result of extended work schedules,
                 displacement from traditional occupations, and relative wages.

                 High Case Analysis

                    Baseline employment projections and information relating to the model analysis used to arrive at these
                 projections are presented in Section IV.D.La.(12)(a). This information is incorporated by reference.
                 Unexpected events (such as the 1973 Arab Oil Embargo) may influence oil and gas activity on the OCS within
                 the Gulf of Mexico Region. These events cannot be projected and cannot be presumed for in this analysis.
                    Approximately 101,100 person-years of employment (direct, indirect, and induced) are required to sustain
                 the proposed action in the High Case throughout its 35-year life (Table IV-29). Less than 2 percent of total
                 employment in support of the proposed action is expected to affect the Western Gulf coastal subareas (Subarea
                 W-2). The remaining employment is expected to lie within coastal Subareas C-1 (23%), C-2 (43%), C-3 (28%),
                 and C-4 (4%). In the peak year of 1999, approximately 4,374 person-years of total employment are required
                 to support the High Case. The greatest amount of this employment is expected to lie within Subarea C-2. A
                 comparison between the expected population and employment impacts for the coastal subareas as a result of
                 the High Case and the expected population and employment without the proposal is shown in Table IV-30.










                                                                                                                            IV-269

                 The greatest impact on employment is expected to occur in coastal Subareas C-1 and C-2, with peak-year
                 impact estimates in 1999 of 0.38 and 0.37 percent, respectively.
                    Short-term fluctuations in the work force as a result of changing levels of activities could affect social
                 patterns in several ways. Large amounts of short-term layoffs in oil and gas industry personnel could result
                 in large numbers of persons returning to traditional ways of employment (i.e., fishing, trapping, farming, etc.),
                 thereby stressing the various resources that would be exploited. A large increase in the hiring of off and gas
                 industry personnel could attract persons engaged in traditional occupations, leaving fewer persons in them in
                 the coastal subareas and, perhaps, resulting in the loss of traditional knowledge associated with these
                 occupations.
                    The potential effects of work force fluctuations on extant subcultures in the coastal subareas are expected
                 to be greatest when large changes in OCS-related activity result in net positive or negative migration. The
                 quality of family life, in pertinent individual cases, could be adversely affected from the stress of decreased
                 family income and loss of security resulting from layoffs in the OCS oil and gas industry. The expected impact
                 on family life, in pertinent individual cases, from increased hiring in the OCS-related off and gas industry would
                 be decreased monetary stress and an increased financial security. Problems related to work scheduling may
                 arise and are discussed below. As mentioned above, employment impacts under the High Case are not
                 expected to exceed 0.38 percent in the peak year of 1999. Projected employment associated with the proposal
                 is expected to come from those already employed in OCS-related activities and from the unemployed and
                 underemployed, and new employees already living in the coastal subareas (Section IV.D.La.(12)(a)). It is
                 expected that the High Case will not result in large increases or decreases in OCS-related employment within
                 the Central and Western Gulf coastal subareas.
                     Both in-migration and out-migration could have an adverse effect on social patterns in the Central and
                 Western Gulf coastal subareas. Expected adverse effects of in-migration could include the loss of cultural
                 homogeneity, the loss of community cohesion, and changes in the quality of life with possible associated stresses
                 to social patterns. Expected adverse effects of out-migration could include stress placed on family life by the
                 departure of extended family members; the departure of persons engaged, part-time, in traditional occupations;
                 and impacts to community cohesion by the departure of long-time residents. Projected population impacts in
                 the Central and Western Gulf coastal subareas are not expected to exceed 0.40 percent (1999-peak year). An
                 analysis of historical trends indicates that only population impacts greater than 1 percent typically involve
                 positive net migration into a given area. None of the coastal subareas is projected to experience population
                 impacts greater than I percent as a result of the High Case. Employment in support of the proposal is
                 expected to come from those currently employed in OCS-related oil and gas activities as well as the
                 unemployed and underemployed, and new employees already living in the area. It is assumed that employment
                 as a result of the proposal will decrease the amount of out-migration, compared to that which would occur
                 without the proposal.
                     Distance to the site and the type of transportation needed for personnel in OCS-related oil and gas
                 activities results in the normal work schedule occurring as a large block of time on duty (or at site) followed
                 by a large block of time off duty. The schedules may range from 7 days on followed by 7 days off to a 30 day-
                 on/30 day-off schedule. It has been argued that this type of schedule has allowed for the participation in, and
                 continuance of, traditional occupations (Hallowell, 1979; Laska, personal comm., 1991), thereby assisting in the
                 maintenance of cultural viability. It is expected that stress will be placed on family life in response to the
                 regular absences of a parent (usually the father). In some cases, it is expected that adaptation to changing
                 family roles will occur. In other cases, it is expected that adaptation will not occur and that deleterious impacts
                 to family life, in pertinent individual cases, will occur. In the peak year of 1999, approximately 4,374 person-
                 years of total employment are required to support the proposed action. Many of those employed will be
                 working in secondary and tertiary jobs and will not encounter the extended work schedule mentioned above.
                 Of those persons employed in OCS-related oil and gas activity and working the extended schedule, it is
                 expected that some families will not adapt to these conditions and that deleterious impacts to family life will
                 occur.
                     Displacement from traditional occupations could originate from destruction of a resource base, space-use
                 conflict, and voluntary shifts from traditional occupations to employment in OCS-related activities. Adverse
                 effects resulting from displacement from traditional occupations could include a diminishment in the number









                 IV-270

                 of participants in traditional occupations, the loss of traditional knowledge and cultural heritage, and deleterious
                 impacts to family life as a result of the displacement. Space-use conflicts have been discussed in Section
                 IV.D.La.(9). The existence of the Fisherman's Contingency Fund mitigates, to some extent, space-use conflicts
                 associated with commercial fishing. A total of 239 claims was filed in 1990 and $212,453.24 were paid to
                 persons attributing damage to OCS-related debris. According to Sections IV.D.La.(1)(b) and IV.D.2.a.(l)(b),
                 the High Case is expected to have a very low impact on coastal wetlands in both the CPA and WPA. It is
                 therefore assumed that very little displacement from traditional occupations win occur as IL result of OCS-
                 related destruction of wetlands. As mentioned above, the extended work schedule associated with many OCS-
                 related jobs may allow for continued participation in traditional occupations. It is expected that relatively few
                 persons will be displaced from traditional occupations as a result of the High Case.
                     The relatively high wages paid to OCS-related oil and gas industry personnel can result in the voluntary
                 shift of persons engaged in traditional occupations to more lucrative positions within the oil and gas industry.
                 Dependency on these relatively high wages may have deleterious impact on family life, particularly if layoffs
                 occur and the wage-earner cannot find work at comparable pay. It is assumed that some persons engaged in
                 lower-paying traditional occupations will seek employment in OCS-related oil and gas activities. Thoseengagcd
                 in extended work schedules will retain the ability to participate in traditional occupations on a. part-time basis.
                 Employment projections for the life of the proposed action under the High Case indicate that peak-year
                 employment (1999) will total approximately 4,374 persons throughout the Central and Western Gulf coastal
                 subareas. It is expected that employment will come from persons already working in OCS-related oil and gas
                 activities as well as the unemployed and underemployed, and new employees already living in the area. The
                 relatively small amount of employment associated with the High Case, in comparison with total employment
                 in the Central and Western Gulf, lessens the impact of relatively high wages paid to OCS-rellated off and gas
                 industry personnel on social patterns.
                    Impacts on social patterns would be related to dramatic changes in population and ffie disruption of
                 environmental resources, as well as conditions inherent to OCS-related employment (i.e., work scheduling and
                 rate of pay). Specific impact-producing factors examined in this analysis include work force fluctuations,
                 migration into or out of the coastal subareas, work scheduling, displacement from traditional occupations, and
                 relative income. An analysis of historical trends indicates that population impacts of greater than 1 percent
                 typically involve positive net migration into a given area. Population impacts under the High Case are not
                 expected to exceed the peak-year impact of 0.40 percent. No positive net migration into @the Central and
                 Western Gulf coastal subareas is expected to occur as a result of the proposal. It is expected that employment
                 will occur from those currently employed in the oil and gas industry, as well as the unemployed and
                 underemployed, and new employees already living in the area. It is expected that jobs created by the proposal
                 would likely reduce the amount of out-migration when compared to scenarios without the proposal. It is
                 expected that minor displacement from traditional occupations will occur as a result of the proposed action.
                 This displacement will be mitigated, to some extent, by the extended work schedule associated with OCS-
                 related employment. However, the extended work schedule is expected to have some deleterious effects on
                 family life in some individual cases. Impacts caused by the displacement of traditional occupations and relative
                 wages are expected to occur to a minimal extent.

                 Conclusion

                    It is expected that no net migration will occur as a result of the High Case scenario. Deleterious impacts
                 on social patterns are expected to occur in some individual cases as a result of extended work schedules,
                 displacement from traditional occupations, and relative wages.
                 b. Alternative B - The Proposed Action Excluding the Blocks Near Biologically Sensitive
                    Topographic Features

                    Alternative B would offer approximately 5,194 unleased blocks in the CPA for leasing; it differs from
                 Alternative A (the proposed action) only by not offering the 62 unleased blocks of the 167 total blocks that
                         My affected by the proposed Topographic Features Stipulation (Section ILA-Le.(1)). All the
                 are possi










                                                                                                                          IV-271

                assumptions and estimates are the same as in the Base Case of Alternative A. Details are presented in
                Sections I.A. and ILA-2.
                    The analyses of impacts are based on the Base Case scenario of Alternative A. These scenarios were
                formulated to provide sets of assumptions and estimates on the amounts, locations, and timing for OCS
                exploration, development, and production operations and facilities, both offshore and onshore. These are
                estimates only and not predictions of what will happen as a result of holding this proposed sale. A detailed
                discussion of the development scenarios and major, related impact-producing factors is included in Sections
                W.A. and B.
                    It should be emphasized that the analyses of impacts to the various resources under Alternative B are very
                similar to those for Alternative A. The reader should refer to the appropriate discussions under Alternative
                A for additional and more detailed information regarding impact-producing factors and their expected effects
                on the various resources.
                    To facilitate the analysis, the Federal offshore area is divided into subareas. The CPA comprises four
                subareas (C-1, C-2, C-3, and C-4), and the coastal region is divided into four coastal subareas (C-1, C-2, C-3,
                and C-4). These subareas are delineated on Figure IV-1.

                (1) Impacts on Sensitive Coastal Environments

                (a) Coastal Barfier Beaches

                    The activities that could affect barrier beaches under Alternative B include oil spills, pipeline
                emplacements, dredging of new navigation channels, deepening of existing channels, maintenance dredging and
                vessel usage of existing navigation channels, and the construction of onshore facilities on barrier features.
                    As in the Base Case, there is a less than a 1 percent chance of occurrence and contact from a spin greater
                than or equal to 1,000 bbL Because of this very low probability, no contact from a spill greater than or equal
                to 1,000 bbl is assumed to occur. No spills greater than 50 and less than or equal to 1,000 bbl are assumed
                to contact barrier features. One or two spills greater than 1 and less than or equal to 50 bbl will occur inshore
                and contact the landward side of barrier beaches. These spins win contact about 2 kin of coast, and win be
                cleaned without the removal of sand. No oil will contact sand dune areas. The barrier features will not be
                affected by contact from these spills.
                    No pipeline landfalls, navigation channels, or new infrastructure construction projects are expected as a
                result of Alternative B. Some maintenance dredging of existing channels will occur under Alternative B. Only
                a small percentage of the usage of these channels, however, can be attributed to OCS support activities under
                Alternative B. Consequently, although maintenance dredging of channels that cut across barrier landforms
                could result in some localized beach erosion downdrift from the mouth of the channel, only a small percentage
                of these impacts can be attributed to OCS activities. One navigation channel is expected to be deepened to
                provide access for deeper draft service vessels used for deepwater operations. Dredged material from this
                project will be disposed of in the coastal littoral zone to enhance coastal stabilization.

                Conclusion

                    Alternative B is not expected to result in permanent alterations of barrier beach configurations, except in
                localized areas downdrift from navigation channels that have been dredged and deepened. The contribution
                to this localized erosion is expected to be less than I percent.

                (b) Wetlands

                    The activities that could affect wetlands under Alternative B include off spills, pipeline emplacements,
                dredging of new navigation channels, maintenance dredging and vessel usage of existing navigation channels,
                and the construction of onshore facilities on barrier features. The impacts expected from Alternative B do not










                 IV-272

                 greatly differ from those associated with OCS development under the Base Case scenario because the deleted
                 offshore blocks are located at a distance from coastal wetland habitats.
                      As in the Base Case, there is a less than 1 percent chance of occurrence and contact from a spill greater
                 than or equal to 1,000 bbl. Because of this low probability, it is assumed that no contact from a spill of 1,000
                 bbl or greater will occur. No spills greater than 50 and less than or equal to 1,000 bbl arc assumed to contact
                 wetlands. Several spills greater than I and less than or equal to 50 bbl will occur from both offshore and
                 inshore sources and contact the coast In Louisiana, where most CPA oil and gas activity occurs, several spills
                 greater than I and less than or equal to 50 bbl could result in short-term (up to four years) dieback effects on
                 10-15 ha of wetlands and the permanent conversion of 2 ha of wetlands into open water and mudflats over the
                 35-year life of the proposed action.
                     Produced waters transported to shore will be either reinjected or disposed of in offshore state waters or
                 the Mississippi River and its passes. No impacts to wetlands under these conditions are anticipatcd, based on
                 an analysis of the results of field and remote sensing investigations in coastal Louisiana (Boesch and Raba",
                 1989b).
                     No pipeline landfalls, navigation channels, or new infrastructure construction projects are expected as a
                 result of Alternative B. Although no new waste sites will be constructed for OCS-gencrated waste disposal,
                 seepage from existing sites could affect nearby wetlands. Some maintenance dredging of existing channels will
                 occur under Alternative B. Only a small percentage of the usage of these channels, however, imn be attributed
                 to OCS support activities under Alternative B. Consequently, although maintenance dredging of channels that
                 cut through wetlands could result in burial of wetlands with dredge spoil and the reinforcement of secondary
                 impacts associated with canal-induced hydrologic changes, only a small percentage of these impacts can be
                 attributed to OCS activities. The deepening of one navigation channel for deeper draft service vessels is
                 projected under Alternative B. This analysis assumes that the dredged material will be disposed of to enhance
                 wetland growth and create new wetlands. The creation of several hectares of new wetlands is anticipated as
                 a result of channel deepening. Alternative B will result in a reduction in resource development, compared with
                 the Base Case scenario. The amount of vessel traffic required under Alternative B for suppl,
                                                                                                                    y vessels, barges,
                 and shuttle tankers will be less than or equal to that required under the Base Case. Up to several hectares
                 of wetlands along channel banks could be eroded by waves generated by vessel traffic associated with
                 Alternative B.


                 Conclusion

                     Alternative B is expected to result in dieback and mortality of 10-15 ha of wetlands vegetation as a result
                 of contacts from onshore oil spills. All but 2 ha of these wetlands will recover within 10 years; the remaining
                 2 ha will be converted to open water. About 5.5 ha of wetlands are projected to be eroded along channel
                 margins as a result of OCS vessel wake erosion, and 3.5 ha of wetlands are projected to be created as a result
                 of beneficial disposal of dredged material from channel deepening projects.
                 (2) Impacts on Sensidye Offshore Resources
                 (a) Live Bouorns (Pinnacle Trend)

                     The live bottoms of the pinnacle trend region are located in the northeastern portion of Ile Central Gulf
                 and adjacent areas of the Eastern Gulf between 73- and 101-m (240- and 330-ft) water depth in the Main Pass
                 and Viosca Knoll lease areas. The pinnacles are scattered in this area and include recently documented live-
                 bottom areas that may be sensitive to oil and gas activities. Leases in past sales have contained a live-bottom
                 stipulation for protection of such areas, and a proposed stipulation is presented in Section II.Al.c.(2) as a
                 possible mitigating measure for leases resulting from the proposed action.
                    A number of OCS-related factors may cause adverse impacts to the pinnacle trend communities and
                 features. Damage caused by oil spills (which have the potential to foul benthic communities and cause the
                 death or disruption of organisms), blowouts (which have the potcntia'l of resuspending considerable amounts










                                                                                                                             IV-273

                 of sediment and releasing hydrocarbons into the water column), anchoring (which may damage lush biological
                 communities or the structure of the pinnacles themselves), structure emplacement (which will crush the
                 organisms directly beneath the legs or mat used to support the structure) and removal (which can suspend
                 sediments throughoutthe water column to the surface), drilling discharges (that can smother organisms through
                 deposition of sediments), and pipeline emplacement (through burial and disruption of the benthos) can cause
                 the immediate death of numerous organisms or the alteration of sediments to the point that recolonization of
                 the affected areas may be delayed or impossible.
                      Estimates presented in Table IV-2 project the level of impact-producing factors that may result from the
                 proposed action. Approximately 1,430,000 bbl of drilling muds and 344,000 bbI of drill cuttings will be
                 discharged from 290 exploration or delineation and production wells over the 35-year life of the proposed
                 action in offshore Subarea C-3. Approximately 80 km of pipeline will be installed to transport production from
                 the eight platforms projected to be emplaced.
                      Activities resulting from the proposed action are not expected to have a high level of impact on the
                 pinnacle trend environment, because the activities for this analysis are restrained by the implementation of the
                 proposed Live Bottom Stipulation. The impact to the pinnacle trend area as a whole is expected to be slight
                 because no community-wide impacts are expected. The implementation of the proposed Live Bottom
                 Stipulation would preclude the occurrence of the most potentially damaging of these activities associated with
                 mechanical damages. Impacts are expected to be infrequent because of the limited operations in the vicinity
                 of the pinnacles and the small size of many of the features. Potential impact levels from oil spills greater than
                 or equal to 1,000 bbl, blowouts, pipeline emplacement, muds and cuttings discharges, and structure removals
                 are very low because the analysis includes the proposed Live Bottom Stipulation. The frequency of impacts
                 to the pinnacles is low, and the severity is judged to be slight because of the widespread nature of the features.

                 Conclusion

                      The impact of Alternative B on the pinnacle trend region in the Gulf of Mexico is expected to be such that
                 any changes in the regional physical integrity, species diversity, or biological productivity of the pinnacle trend
                 region would recover to pre-impact conditions in less than 2 years, more probably on the order of 2-4 months.

                 (b) Deep-water Benthic Communities
                      The sources and severity of impacts associated with this alternative are those sale-related activities
                 discussed for the Base Case. As noted in Section IV.13.1.a.(2)(b) for the Base Case, the impact-producing
                 factors threatening these communities result from those activities that would physically disturb the bottom, such
                 as the routine operations of anchoring, drilling, and pipeline installation, and the infrequent seafloor blowout
                 accident. A more detailed examination of this potential impact-producing factor is presented in that section.
                      As noted in Section IV.D.1.a.(2)(b) above, high-density chemosynthetic communities are found only in
                 water depths greater than 400 rn (1,312 ft). Thus, they will not be found in Subarea C-1; they will be found
                 only in the southeast third of Subarea C-2 and the southern two-thirds of C-3; they may be found throughout
                 C4. Thus, these communities will not be exposed to the full level of the projected impact-producing factors
                 of Table IV-2. None of the excluded blocks are in areas in which chemosynthetic communities may be
                 expected, because the excluded blocks are in much shallower water near the topographic features.
                      The majority of these deep-water communities are of low density and are widespread throughout the deep-
                 water areas of the Gulf, and disturbance to a small area would not result in a major impact to the ecosystem.
                 For purposes of this analysis, the frequency of such impact is expected to be once every six months to two
                 years, and the severity of such an impact is judged to result in few losses of ecological elements with no
                 alteration of general relationships.
                      High-density communities are largely protected by the provisions of NTL 88-11. For purposes of this
                 analysis, the frequency of some small percentage of impact is expected to be once every six months to two
                 years, but the severity of such an impact is such that there may be some loss of ecological elements and/or
                 some alteration of general relationships.










                   IV-274


                   Conclusion


                        Aternative B is expected to cause little damage to the physical integrity, species diversity, or biological
                   productivity of either the widespread, low-diversity chemosynthetic communities or the rare, widely scattered,
                   high-density Bush-Hill type chemosynthetic communities. Recovery from any damage is expected to take less
                   than 2 years.

                   (c) Topographic Features

                        The sources and severity of impacts associated with this alternative are those sale-related activities
                   discussed for the Base Case. As noted in Section IV.D.La.(2)(c) for the Base Case, the potential impact-
                   producing factors to the topographic features of the Central Gulf are anchoring and structure emplacement,
                   effluent discharge, blowouts, oil spills, and structure removal. A more detailed examination of these potential
                   impact-producing factors is presented in that section.
                        Fifteen of the 16 topographic features of the CPA are located in Subarea C-2; 1 is in C-3 (in both cases
                   they occupy a very small portion of the entire area). Thus, these communities will not be exposed to the full
                   level of the projected impact-producing factors of Table IV-2. This alternative differs from Alternative A by
                   excluding the 61 unleased blocks near the topographic features in C-2 and the 1 unleased block near the bank
                   in C-3. (These excluded blocks are the blocks that would be subject to the proposed Topographic Features
                   Stipulation under Alternative A. It should be noted that 105 of the total of 167 blocks subject to the proposed
                   stipulation are currently leased.) The amounts of wastes discharged in the vicinity of a bank will be some very
                   small fraction of those shown in Table IV-2.
                        Of the potential impact-producing factors to the topographic features, anchoring, structure emplacement,
                   and structure removal will be eliminated by the adoption of this alternative. Effluent discharge and blowouts
                   will not be a threat because blocks near enough to the banks for these events to have an impact on the biota
                   of the banks will have been excluded from leasing. Thus, the only impact-producing factor remaining, from
                   operations in blocks included in this alternative (i.e., those blocks not excluded by this alternative), is an oil
                   spin.
                        There is an estimated 16 percent chance of an oil spill greater than or equal to 1,000 bW occurring in the
                   Central Gulf as a result of this alternative (it will be the same as the Base Case of Alternative A) (Table IV-
                   19). It is assumed that 21 spills of greater than 1 and less than or equal to 50 bbl will occur each year and that
                   I spill of greater than 50 and less than 1,000 bbl and I spill of 6,500 bbl is assumed to occur during the 35-year
                   life of the proposed action (Section W.C.1.). In addition, it is assumed there will be 4 spilh; of diesel oil and
                   other pollutants, the average size of which will be only 34 bbl (Table IV-2). In the Central Gulf, Sonnier Bank
                   crests the shallowest at 18 m. Therefore, a surface oil spill would likely have no impact on the biota of Sonnier
                   Bank or the other topographic f6atures because any oil that might be driven to 18 m or deeper would be well
                   below the concentrations needed to cause an impact. However, spills resulting from this proposal are assumed
                   to be subsurface; such spills are likely to rise to the surface, and any oil remaining at depth will be swept clear
                   of the banks by currents moving around the banks (Rezak et al., 1983). A seafloor oil spill would have to come
                   into contact with a biologically sensitive feature to have an impact. The fact that the topographic features are
                   widely dispersed in the Central Gulf, combined with the probable random nature of spill locations, would serve
                   to limit the extent of damage from any given spill to only one of the sensitive areas. The currents that move
                   around the banks will steer any spilled oil around the banks rather than directly upon them, lessening the
                   severity of impacts.

                   Conclusion


                        Alternative B is expected to cause little to no damage to the physical integrity, species diversity, or
                   biological productivity of the habitats of the topographic features of the Gulf of Mexico. Small areas of 5-10
                   M2 would be impacted, and recovery from this damage to pre-impact conditions is expected to take less than










                                                                                                                               IV-275

                 2 years, probably on the order of 24 weeks. Selection of Alternative B would preclude oil and gas operations
                 in the unleased blocks affected by the proposed Topographic Features Stipulation.

                 (3) Impacts on Water Quality

                     All existing onshore infrastructure and associated coastal activities occurring in support of the proposed
                 action will contribute to the degradation of regional coastal and nearshore water quality to a minor extent
                 because each provides a low measure of continuous contamination and because discharge locations are
                 widespread. The effect of chronic contamination on the Gulfs coastal waters due to the proposed action is
                 considered negligible, with water characteristics rapidly returning to background levels. The OCS-related vessel
                 traffic is likely to impact water quality through routine releases of bilge and ballast waters, chronic fuel and tank
                 spills, trash, and low-level releases of the contaminants in antifouling paints. Given the small concentrations
                 of the releases anticipated, and their continuous and widespread nature, it is expected that there will be some
                 localized, short-term change (up to several weeks) in water quality characteristics from background levels,
                 depending on the length of the affected channel, flushing rates, and other factors. The OCS produced-water
                 discharges are not assumed to degrade coastal and nearshore waters because of the new State regulations
                 phasing out the discharge of these waters into Louisiana's State waters. The improper storage and disposal
                 of off-field wastes and NORM-contaminated oil-field equipment would adversely impact surface and ground
                 waters in proximity to disposal facilities, cleaning sites, and scrap yards. Surface and groundwater in proximity
                 to improperly designed and maintained disposal sites and facilities could be adversely impacted with elevated
                 concentrations of arsenic, chromium, zinc, cadmium, mercury, lead, barium, penta-chlorophenol, naphthalene,
                 benzene, toluene, and radium.
                     Immediate effects would be brought about by increased drilling, construction, and pipelaying activities,
                 causing an increase in water column turbidities (lasting for several hours for mud discharges to several weeks
                 for pipelaying and dredging activities) to the affected offshore waters. The magnitude and extent of turbidity
                 increases would depend on the hydrographic parameters of the area, nature and duration of the activity, and
                 bottom-material size and composition. Offshore Subarea C-1 would receive the greatest portion of program-
                 related pipeline burial activities, whereas offshore Subareas C-2 and C-3 would receive the largest amounts of
                 program-related operational discharges. Because of the continuous nature of off and gas activities in the
                 northwestern and north-central Gulf of Mexico, discharges of drilling mud and cuttings and produced water
                 are judged to be of nearly continuous frequency throughout these areas. Proposed produced-water discharges
                 will be rapidly diluted within the immediate vicinity of the discharge source. Significant increases in water
                 concentrations of dissolved and particulate hydrocarbons and trace metals are not expected outside the initial
                 mixing zone or immediate vicinity of the discharge source. Higher concentrations of trace metals, salinity,
                 temperature, organic compounds, and radionuclides, and lower dissolved oxygen may be present near the
                 discharge source. Long-term effects to water column processes, consisting of localized increases in particulate
                 metal and soluble lower molecular weight hydrocarbon (e.g., benzene, toluene, and xylenes) concentrations,
                 may be implicated within the mixing zone of the discharge. Trace metals and hydrocarbons associated with
                 the discharge may be deposited within sediments near the discharge point. The proposed discharge of drilling
                 fluids and cuttings would rapidly disperse in marine waters. Discharge plumes will be diluted to background
                 levels within a period of several hours and/or within several hundred meters of the discharge source. The
                 accumulation of toxic trace metals and hydrocarbons in exposed shelf waters, due to periodic releases of water-
                 based generic muds and cuttings, is unlikely, and the long-term degradation of the water column from such
                 discharges is not a major concerns.
                      One oil spill greater than or equal to 1,000 bbl and one oil spill greater than 50 and less than 1,000 bbl
                 are assumed to occur, but not assumed to contact coastal and nearshore waters. An additional 31 spills greater
                 than 1 but less than or equal to 50 bbl are assumed from OCS sale-related activities both in the coastal zone
                 and offshore. Of these, fewer than 10, associated with onshore support and vessel activities, are assumed to
                 occur in coastal waters. Program-related spills will introduce oil into nearshore waters, creating elevated
                 hydrocarbon levels (up to 100+ lAg/1) within affected waters. Much of the oil will be dispersed throughoutthe
                 water column over several days to weeks. In shallow areas, oil may become entrained in suspended particles










                 IV-276

                 and bottom sediments. Water uses would be affected for up to several weeks from proposed spills and then
                 only near the source of slick.

                 Conclusion

                     An identifiable change to the ambient concentration of one or more water quality parameters win be
                 evident up to several hundred to 1,000 in from the source and for a period lasting up to several weeks in
                 duration in marine and coastal waters. Chronic, low-level pollution related to the proposal will occur
                 throughout the 35-year life of the proposed action.

                 (4) Imp"ts on Air Qudhy

                     Alternative B will offer for lease all unleased blocks in the proposed action, excluding the 62 unleased
                 blocks near biologically sensitive topographic features in the CPA.
                     A description of CPA air quality is provided in Section III.A.3., and descriptions of the potential impact-
                 producing factors are provided in Section IV.A- An analysis of the impacts of Alternative A is presented in
                 Section IV.D.I.a.(4).
                     The size of the area and the number of blocks available for lease under Alternative A L& large. Because
                 only 62 blocks would be withheld from proposed Sale 142 if Alternative B were adopted, it is expected that
                 activities, infrastructure, and other factors described in that analysis will not change appreciably. The reader
                 may consult Table IV-2 for the number of wells and platform complexes related to Alte:rnative A- It is
                 conceivable, given the small size of the changes produced by Alternative B, that the analyses described in
                 Alternative A will not changed.
                     It is assumed under the proposed action that 340 exploration and delineation wells and 2,50 development
                 wells will be drilled, and 30 platform complexes will be emplaced. The information presented below displays
                 emissions for each suba rea during the life of the proposed action.

                                                       Total Emissions in CPA Subareas
                                                (tons over 35-year life of the proposed action)

                             Pollutant                    C-1           C-2               C-3                C-4

                                  NO.                12,979.9          10,816.6         21,633.1          19,469.8
                                   CO                 1,875.5           1,562.9          3,125.8           2,813.2
                                  so.                   169.3             141.1            282.2             254.0
                                 THC                  4,046.1           3,372.1          6,744.3           6,069.8
                                  TSP                   261.1             217.6            435.2            391. 7

                     The discussion of the meteorology and pollutant dispersion presented under Alternative A indicates that
                 the release of pollutants over the Gulf waters occurs relatively close to the surface (30 in) and that prevailing
                 atmospheric conditions will promote vertical and horizontal mixing of the plume. During night and morning
                 hours and in the winter, even though turbulence is available, the mixing height would be low, so that little
                 dilution would occur. During the summer, the available turbulent energy and the greater mixing heights will
                 allow greater dispersion and dilution of pollutants. During high-wind conditions, the dispcrsiDn win be much
                 larger, reducing the concentrations to even lower levels. The only pollutant that may remain in large
                 concentrations is NOx.
                     More important are the potential impacts of these emissions on inshore air quality. It is reasonable to
                 expect that emissions reaching land will be minimal from Subareas C-2 and C-4, and the southern portions of
                 C-3. Emissions from subareas close to land, C-1 and the northern portions of C-3, will be carried mostly
                 offshore in winter. In summer, mixing over the Gulf waters is intensive and the arriving concentrations will be
                 diminished. At the coastline, the effects will depend on the level of concentration of arriving pollutants. For










                                                                                                                          IV-277

                 NOy, however, the concentrations may not be low. Numerical modeling by MMS of pollutant transport to
                 inshore areas reveals that inert pollutants have very low concentrations when they reach the onshore.
                    Oil spins of all categories have temporal effects on offshore air quality and are limited to the immediate
                 vicinity of the spill.
                    Offloading of crude oil from surface vessels at ports is estimated to be near 4 percent of the OCS
                 production. The emission rates of these unintentionalemissions are small, and it is estimated that they produce
                 negligible effects on CPA inshore air quality. Tugboat emissions in these operations are expected to produce
                 negligible effects on air quality.
                    Suspended particulate matter is important because of its potential in degrading the visibility in national
                 wildlife parks or recreational parks, designated as Type I areas. Particles larger than 10 microns will have small
                 concentrations because they settle very fast. Particles of 10 microns or smaller remain floating in the air for
                 long periods, but their low concentrations generally will have little effect on the visibility of these areas. The
                 selection of Alternative B can diminish effects on the air quality from the above impact producing factors, but
                 not enough to change the impacts expected under Alternative A.

                 Conclusion

                    Emissions of pollutants into the atmosphere from activities assumed for Alternative B are expected to have
                 concentrations that would not change onshore air quality classifications. Increases in onshore concentrations
                 of air pollutants from Alternative B are estimated to be about I gm3 (box model steady concentrations). This
                 concentration will have minimal impact during winter because onshore winds occur only 37 percent of the time
                 and maximum impacts in summer when onshore winds occur 61 percent of the time.

                 (5) Impacts on Coastal and Matine Mammals

                 (a) Marine Mammals

                 Nonendangered and Nonthreatened Species
                     This section discusses the impact of the adoption of Alternative B, which excludes biologically sensitive
                 offshore habitats, on nonendangered and nonthreatened cetaceans (including whales and dolphins). The level
                 of activity associated with the alternative is the same as the summary of infrastructure and activity described
                 for the Base Case in Table IV-2. The sources and severity of impacts for nonendangered and nonthreatened
                 species in Alternative B are the same as those discussed for the Base Case (Section IV.D.l.a.(5)). The impacts
                 include operational discharges, helicopter and vessel traffic, drilling operations, explosive platform removals,
                 seismic surveys, oil spins, and oil-spill response activities. The effects of these activities are expected to be
                 primarily nonlethal and the probability of an interaction is unlikely. Lethal effects are expected only from oil
                 spills greater than or equal to 1,000 bbl.

                 Conclusion

                     The impact of Alternative B on nonendangered and nonthreatened marine mammals is expected to result
                 in sublethal effects that are chronic and could result in persistent physiological or behavioral changes, as wen
                 as some degree of avoidance of the impacted area(s).

                 Endangered and 7hreatened Species

                     This section discusses the impact of the adoption of Alternative B, which excludes biologically sensitive
                 offshore habitats, on endangered and threatened cetaceans. The level of activity associated with the alternative
                 is the same as the summary of infrastructure and activity described for the Base Case in Table IV-2. The
                 sources and severity of impacts for endangered and threatened species in Alternative B are the same as those










                  IV-278

                  discussed for the Base Case (Section IV.D.La.(5)). The impacts include operational discharges, helicopter and
                  vessel traffic, drilling operations, explosive platform removals, seismic surveys, oil spills, and oil-spill response
                  activities. The effects of these activities are expected to be primarily nonlethal and the probability of an
                  interaction is unlikely. Lethal effects are expected only from oil spills greater than or equal to 1,000 bbl.

                  Conclusion

                       The impact of Alternative B on endangered and threatened marine mammals is expected to result in
                  sublethal effects that are chronic and could result in persistent physiological or behavioral changes, as well as
                  some degree of avoidance of the affected area(s).
                  (b) Alabama, Choctawhatchee, and Perdido Key Beach Mice

                      This section discusses the impact of the adoption of Alternative B, which excludes bkilogically sensitive
                  offshore habitats, on the Alabama, Choctawhatchee, and Perdido Key beach mice. The level of activity
                  associated with the alternative is the same as the summary of infrastructure and activity described for the Base
                  Case in Table IV-2. The sources and severity of impacts for beach mice in Alternative B are the same as those
                  discussed for the Base Case (Section IV.D.La.(5)). The impacts include habitat alteration and physical contact
                  with oil and oil-spill response activities. The effects of these activities are expected to be primarily nonlethal
                  and the probability of an interaction is unlikely. Lethal effects are expected only from oil spills greater than
                  or equal to 1,000 bbl.

                  Conclusion

                      The impact of Alternative B on the Alabama, Choctawhatchee, and Perdido Key beach mice within the
                  potentially affected area is expected to result in sublethal effects that seldom occur and may cause short-term
                  physiological or behavioral changes.

                  (6) Impacts on Marine Turtles

                      This section discusses the impact of the adoption of Alternative B, which excludes biologically sensitive
                  offshore habitats, on marine turtles. The level of activity associated with the alternative is the same as the
                  summary of infrastructure and activity described for the Base Case in Table IV-2. The sources and severity
                  of impacts for marine turtles in Alternative B are the same as those discussed for the Base Case (Section
                  IV.D.La.(6)). The impacts include habitat alteration by physical disturbance and chemical discharges, and
                  direct impacts by trash and debris, vessel traffic, explosive structure removals, and oil or oil-spill response
                  activities. The effects of these activities are expected to be primarily nonlethal and the probability of an
                  interaction is unlikely. Lethal effects are expected only from oil spills greater than or equal to 1,000 bbl.

                  Conclusion

                      The impact of Alternative B on marine turtles within the potentially affected area is expected to result in
                  sublethal effects that are chronic and could result in persistent physiological or behavioral changes.

                  (7) Impacts on Coastal and Marine Birds

                  (a) Nonendangered and Nonthreatened Species

                     The Gulf of Mexico is populated by migrant and nonmigrant species of coastal and marine birds. This
                  broad category consists of four main groups: seabirds, waterfowl, wading birds, and shorebirds.










                                                                                                                             IV-279

                     The sources and severity of impacts associated with this alternative to coastal and marine birds are those
                 sale-related activities discussed for the Base Case (Table IV-2). As noted in Section IV.D.l.a.(7) for the Base
                 Case, effects that may result from this alternative include off spills, disturbance from OCS service-vessel and
                 helicopter traffic near coastal areas, displacement from onshore pipeline landfalls and facility construction near
                 coastal areas, and entanglement and ingestion of offshore oil- and gas-related plastic debris.
                     It is expected that the effects from the major impact-producing factors on coastal and marine birds are
                 negligible and of nominal occurrence. As a result, there will no discernible disturbance to Gulf coastal and
                 marine birds.


                 Conclusion

                     The impact of Alternative B on nonendangered and nonthreatened coastal and marine birds is expected
                 to result in no discernible decline in a population or species, and no change in distribution and/or abundance
                 on a local or regional scale. Individuals experiencing sublethal effects will recover to predisturbance condition
                 in less than one generation.

                 (b) Endangered and Threatened Species

                     This section discusses the impact of Alternative B, which excludes biologically sensitive offshore habitats,
                 on endangered and threatened coastal and marine birds. The sources and severity of impacts associated with
                 this alternative to endangered and threatened species of coastal and marine birds are those sale-related
                 activities discussed for the Base Case. The endangered and threatened birds include the piping plover, brown
                 pelican, bald eagle, and Arctic peregrine falcon. The level of activity associated with the alternative is the same
                 as the summary of infrastructure and activity described for the Base Case in Table IV-2. The sources and
                 severity of impacts in Alternative B for endangered and threatened coastal and marine birds are the same as
                 those discussed for the Base Case (Section IV.D.La.(7)). The impacts include habitat alteration by physical
                 disturbance and chemical discharges, and direct impacts by trash and debris, vessel traffic, explosive structure
                 removals, and oil or off-spill response activities. The effects of these activities are expected to be primarily
                 nonlethal and the probability of an interaction is unfikely. Lethal effects are expected only from oil spins
                 greater than or equal to 1,000 bbl.

                 Conclusion

                     The impact of Alternative B on endangered and threatened coastal and marine birds is expected to result
                 in no discernible decline in a population or species and no change in distribution and/or abundance on a local
                 or regional scale. Individuals experiencing sublethal effects will recover to predisturbance condition in less than
                 one generation.

                 (8) Impacts on the Gulf Sturgeon

                     This section discusses the impact of the adoption of Alternative B, which excludes biologically sensitive
                 offshore habitats, on the Gulf sturgeon. The level of activity associated with the alternative is the same as the
                 summary of infrastructure and activity described for the Base Case in Table IV-2. The sources and severity
                 of impacts in Alternative B for the Gulf sturgeon are the same as those discussed for the Base Case (Section
                 IV.D.I.a.(8)). The impacts include off spills. The effects of these activities are expected to be primarily
                 nonlethal and the probability of an interaction is unlikely. Lethal effects are expected only from oil spills
                 greater than or equal to 1,000 bbl. Effects from oil spills of less than 1,000 bbl are expected to be sublethal.










                 IV-280


                 Conclusion


                      The impact of Alternative B on the Gulf sturgeon is expected to result in sublethal effects that cause short-
                 term physiological or behavioral changes.

                 (9) Impacts on Commercial Fisheries

                      The sources and severity of impacts to commercial fisheries are the same in this alternative as those sale-
                 related activities discussed for the Base Case (Table IV-2). As noted in Section IV.D.l.a.(9) for the Base Case,
                 effects that may result from this alternative include emplacement of production platforms, underwater OCS
                 obstructions, production platform removals, seismic surveys, oil spills, subsurface blowouts, and OCS discharges
                 of drilling muds and produced waters.
                      It is expected that the effects from the major impact-producing factors on commercial fisheries in the CPA
                 will be inconsequential and of nominal occurrence. As a result, there will be little discernible disturbance to
                 Gulf commercial fisheries.


                 Conclusion


                      The impact of Alternative B on commercial fisheries is expected to result in short-term decrease in a
                 portion of a population of commercial importance, in an essential habitat, or in commercial fisheries on a local
                 scale. Any affected population is expected to, recover to predisturbance condition in one generation.

                 (10) Impacts on Recreational Resources and Activities

                 (a) Beach Use

                      The sources and severity of beach use impacts associated with the offering of Alternative; B are the same
                 as the sale-related activities discussed for the Base Case. As noted in Section IV.D.I.a.(10)(a) for the Base
                 Case, effects that may result on beach uses from this alternative include oil spills, trash and debris, and the
                 physical presence of drilling rigs and platforms within sight of coastal beaches. The potential effects from these
                 impact-producing factors are described in the discussion in Section IV.D.La.(10)(a).
                      No oil spills of 1,000 bbl or greater and a few spills greater than 1 and less than or equal to 50 bbl are
                 assumed to occur and contact a major recreational beach in the CPA- There will also be the minor,
                 intermittent effect of Utter or trash associated with sale-related OCS operations. Removing tracts associated
                 with the protected biological features noted (far offshore on Visual No. 2) will have no effect on the possibility
                 of a drilling rig or platform being placed in nearshore tracts, within sight of intensively used or wilderness
                 beaches.


                 Conclusion


                      Alternative B is expected to result in minor pollution events and nearshore operations that may adversely
                 affect the enjoyment of some beach users on Texas and Louisiana beaches.

                 (b) Marine Fishing

                      The sources and severity of marine fishing impacts associated with the offering of Alteniative B are the
                 same as the sale-related activities discussed for the Base Case. As noted in Section IV.D.1.a.(10)(b) for the
                 Base Case, effects that may result on marine fishing from this alternative include platform installations and
                 removals and oil spills. Offshore platforms attract fish and fishermen; explosive removal of platforms will kill
                 or critically injure sport fish directly associated with the structure at the time of detonation; and oil spills will
                 tend to discourage fishing.










                                                                                                                                 IV-281

                      The 16 platform complexes expected to be installed and ultimately removed in coastal Subareas C-1 and
                  C-3 will most likely be unaffected by this alternative, as all of the tract deletions associated with this alternative,
                  except one, are in offshore Subarea C-2. A few oil spills greater than 1 and less than or equal to 50 bbl are
                  being assumed. The impact on marine recreational fishing from this pollution will be short term and minor.

                  Conclusion

                      Platforms installed within 30 mi of shore will attract fish and are likely to attract fishermen and improve
                  fishing for a period of about 20 years, but are unlikely to affect offshore fishing patterns in general unless the
                  platforms are installed in nearshore locations where no platforms currently exist

                  (11) Impacts on Archaeological Resources

                      A number of OCS-related factors may cause adverse impacts to archaeological resources. Damage to both
                  historic and prehistoric archaeological resources could be caused by the placement of drilling rigs, production
                  platforms, and pipelines; dredging; and anchoring. These activities could destroy artifacts or disrupt the
                  provenience and stratigraphic context of artifacts, sediments, and paleoindicators, from which the scientific
                  value of the archaeological resource is derived. Oil spills could contaminate site organics and destroy the ability
                  to date prehistoric sites by radiocarbon dating techniques. Ferromagnetic debris associated with OCS oil and
                  gas activities would tend to mask magnetic signatures of significant historic archaeological resources.

                  (a) Historic
                      The offering for lease of all CPA lease blocks, with the exception of the lease blocks near biologically
                  sensitive topographic features, would not result in the deletion of any blocks considered to have a high
                  probability for the occurrence of historic and/or prehistoric archaeological resources. Adoption of the
                  alternative will not change expected impacts from those discussed under the Base Case scenario (Section
                  IV.D.I.a.(11)).
                      Offshore development could result in an interaction between a drilling rig, a platform, a pipeline, dredging
                  activity, or anchors and an historic shipwreck. The result would be the loss of archaeological data on ship
                  construction, cargo, the social organization of the vessel's crew, and the concomitant loss of information on
                  maritime culture for the time period from which the ship dates.
                      Likely locations of archaeological sites on the OCS cannot be delineated without fast conducting a remote-
                  sensing survey of the seabed and near-surface sediments. The location of any proposed activity within a lease
                  block that has a high probability for historic shipwrecks requires archaeological clearance prior to operations.
                  If the expanded database containing the 273 shipwrecks in the entire Central Gulf OCS is considered, the
                  probability of an OCS activity contacting and damaging a shipwreck is fairly low. However, if an oil and gas
                  structure contacted an historic resource, significant or unique archaeological information could be lost. The
                  frequency of such an occurrence, however, is expected to be low. The deletion of blocks near biologically
                  sensitive topographic features will not result in the deletion of any blocks considered to have a high probability
                  for historic archaeological resources. Expected impacts under the alternative are not expected to change from
                  the Base Case.
                      The greatest impact to an historic archaeological resource as a result of the proposed action would result
                  from a contact between an OCS offshore activity (platform installation, drilling rig emplacement, dredging and
                  ipeline projects) and an historic shipwreck. Deletion of the blocks near biologically sensitive topographic
                  features would not result in the deletion of any block considered to have a high probability for historic and/or
                  prehistoric archaeological resources.
                      Because of incomplete knowledge on the location of shipwrecks in the Gulf, an OCS activity could contact
                  a shipwreck. Although this occurrence is not probable, such an event would result in the disturbance or
                  destruction of significant or unique historic archaeological information. Other factors associated with the
                  proposed action are not expected to affect historic archaeological resources.










                  IV-282


                  Conclusion


                      There is a very small possibility of an impact between OCS oil and gas activities and an historic shipwreck
                  or site. Should such an impact occur, significant or unique archaeological information could be lost.

                  (b) Prehistoric

                      Prehistoric sites anticipated to occur in CPA waters offshore include all the types that occur onshore. The
                  baseline study for the Gulf of Mexico (CEI, 1977) identified distinct, high-probability geomorphic features for
                  the occurrence of prehistoric archaeological sites. Two possible prehistoric sites have been located in the
                  western portion of the Central Planning Area as a result of an MMS-funded study (CEI, 1986). These possible
                  sites occurred in association with the ancient Sabine River valley and were identified by coring within Sabine
                  Area, Block 6.
                      Offshore development as a result of the proposed action could result in an interaction that could destroy
                  fragile artifacts or site features and could disturb artifact provenience and site stratigraphy. The limited amount
                  of impact to the seafloor throughout the CPA, coupled with the effectiveness of the archaeological survey and
                  resulting archaeological clearance, is sufficient to assume a low potential for interaction between an impact-
                  producing factor and a prehistoric archaeological site. The adoption of Alternative B will not change expected
                  impacts from those expected under the Base Case.
                      The survey and clearance provide a significant reduction in the potential for a darnaging interaction
                  between an impact-producing factor and a prehistoric site.

                  Conclusion

                      There is a very small possibility of an impact between OCS oil and gas activities and a prehistoric
                  archaeological site. Should such an impact occur, there could be damage to or loss of significant or unique
                  archaeological information.

                  (12) Impacts on Socioeconomic Conditions

                  (a) Populatior; Labor, and Employment

                      Resource estimates and associated infrastructure for the proposed action in the Central Gulf, excluding
                  blocks near biologically sensitive topographic features, are not significantly different from those estimated for
                  the proposed action in the Base Case. Estimates include the drilling of 340 exploration and -delineation wells,
                  the emplacement of 30 platform complexes, and the drilling of 250 development wells (Table IV-2). The
                  sources and severity of impacts to population, labor, and employment are, therefore, the same as those assessed
                  for Central Gulf Sale 142 in the Base Case. A total of approximately 58,500 person-years of employment
                  (direct, indirect, and induced) is required in the Central and Western Gulf coastal subareas in support of
                  Alternative B throughout its 35-year life. Peak annual changes in the population, labor, and employment of
                  all coastal subareas in the Central and Western Gulf resulting from Alternative B represent less than 1 percent
                  of the levels expected in absence of the proposal. The coastal communities of the Western Gulf are expected
                  to support under 2 percent of the total employment generated by the Central Gulf sale under this alternative.
                  Employment resulting from oil-spill clean-up activities is negligible. It is expected that employment demands
                  in support of this alternative will be met with the existing population and available labor force.

                  Conclusion

                      The impact of Alternative B on the population, labor, and employment of the counties and parishes of the
                  Central and Western Gulf coastal impact area is expected to be less than 1 percent of the levels expected in
                  the absence of the proposal.










                                                                                                                          IV-283

                 (b) Public Services and Infrastructure

                     Impacts on public services and infrastructure would be related to dramatic increases or decreases in
                 population. No positive net migration into the coastal subareas of the Central and Western Gulf is expected
                 to occur as a result of Alternative B. It is expected that employment needs will be filled from the existing oil
                 and gas labor pool, as well as the unemployed and underemployed, and new employees already living in the
                 area. In addition, jobs created by the proposal would likely reduce the amount of migration out of the coastal
                 subareas when compared with scenarios without the proposal. It is expected that employees leaving public
                 service and infrastructure-related jobs could be replaced from the existing labor pool.

                 Conclusion

                     Population and employment impacts that result from the proposed action under Alternative B will not
                 result in disruptions to community infrastructure and public services beyond what is anticipated by in-place
                 planning and development agencies.

                 (c) Social Patterns

                     Impacts on social patterns would be related to dramatic changes in population and the disruption of
                 environmental resources, as well as conditions inherent to OCS-related employment (i.e., work scheduling and
                 rate of pay). No positive net migration into coastal subareas of the Central and Western Gulf is expected to
                 occur as a result of the proposal. It is expected that employment will occur from those currently employed in
                 the off and gas industry, as well as the unemployed and underemployed, and new employees already living in
                 the area. It is expected that jobs created by the proposal would likely reduce the amount of out-migration
                 when compared to scenarios without the proposal. It is expected that minor displacement from traditional
                 occupations will occur as a result of Alternative B. This displacement will be mitigated, to some extent, by the
                 extended work schedule associated with OCS-related employment The extended work schedule is expected
                 to have some deleterious effects on family life in pertinent, individual cases. Impacts caused by the
                 displacement of traditional occupations and relative wages are expected to occur to a minimal extent.

                 Conclusion

                     Deleterious impacts to social patterns are expected to occur in some individual cases as a result of
                 extended work schedules, displacement from traditional occupations, and relative wages.

                 c. Impacts from Alternative C - No Action

                 Description of the Alternative

                     Alternative C is equivalent to cancellation of a sale scheduled for a specific time period on the approved
                 5-year OCS Oil and Gas Leasing Schedule. Sales in the Central Gulf are scheduled on an annual basis. By
                 canceling the proposed sale, the opportunity is postponed or foregone for development of the estimated 0.14
                 BBO and 1.40 tcf of gas that could have resulted from proposed Sale 142 in the Central Gulf.

                 Effects of the Alternative

                     If Alternative C is selected, all impacts, positive and negative, associated with the proposed action would
                 be canceled. This alternative would therefore result in no effect on the sensitive resources and activities
                 discussed in Section IV.D.La. The incremental contribution of the proposed action to cumulative effects
                 (Section IV.D.I.d.) would also be foregone, but such effects from other activities, including other OCS sales,










                 IV-284

                 would remain. One contribution to cumulative effects that could increase oil-spill risk due to the importation
                 of foreign oil to replace the resources lost through cancellation of the proposed action.
                     Alternative energy strategies that could provide replacement resources for lost domestic OCS oil and gas
                 production include energy conservation; conventional oil and gas supplies; coal; nuclear power; oil shale; tar
                 sands; hydroelectric power; solar and geothermal energy; and imports of oil, natural gas, and liquefied natural
                 gas (LNG). These are discussed in some detail in Appendix D. A National Energy Strategy is under
                 development by the U.S. Department of Energy (DOE), and the interim report was published April 2, 1990.
                 The energy equivalents that may be required from several alternative energy sources, should this lease sale be
                 permanently cancelled, are shown on Table D-8 and are based on the resources estimated. by MMS to be
                 produced as a result of the proposed action. For the purpose of clarity, this table has separately identified each
                 potential alternative source of energy regarding substitution requirements. It is unlikely, however, that there
                 would be a single, choice between these alternatives sources, but instead, some combined effort to explore and
                 develop further many or all of these forms as a substitute for OCS oil and gas production.

                 d. Impacts of Cumulative Actions

                     This section analyzes "cumulative" actions, defted as other past, present, and reasonably foreseeable future
                 actions, both Federal and nonfederal (40 CFR 1508.7), that when added with actions resulting from the
                 proposed actions result in an incremental impact to the proposed actions (1993-2027), and the resources
                 analyzed are those identified as potentially being impacted from the proposed action. Cumulative impacts can
                 result from individually minor but collectively significant actions taking place over a period of time. See Section
                 IV.B. for details regarding the cumulative scenario and assumptions on which the following analyses are based.

                 (1) Impacts on Sensftive Coastal Environments

                 (a) Coastal Bamer Beaches

                     This Cumulative Analysis considers the effects of impact-producing factors related to the proposed action,
                 plus those related to the Western Gulf proposed action, prior and future OCS sales, State oil and gas activities,
                 other governmental and private projects and activities, and pertinent natural processes that may affect barrier
                 features.
                     Specific impact-producing factors considered in the Cumulative Analysis include sediment reduction, oil
                 spills, pipeline landfalls, onshore infrastructure facilities construction, navigation canals, beach protection and
                 stabilization projects, and recreational activities.
                     As discussed in Section III.B.I.a., under natural conditions, the erosional condition of barrier islands in
                 coastal Louisiana and easternmost Texas is related to the constructional versus the destructional stage of the
                 nearby deltaic landmass. The Mississippi River has been the direct source of sand-size sediment to coastal
                 landforms in Louisiana, and the location of the mouth of the river has determined which areas of the Deltaic
                 Plain were aggrading and which were eroding. The suspended sediment load of the Mississippi River, however,
                 has decreased over 50 percent since the 1950's, largely as a result of dam and reservoir construction upstream
                 within the drainage basin (Turner and Cahoon, 1987). The reduction in sediment supply to barrier beaches
                 in coastal Subareas C-1, C-2, and C-3 has resulted in marine erosion forces dominating the construction
                 processes that tend to build barrier beaches. Sediment deprivation in these subareas will continue to have very
                 high impacts on barrier features during the life of the proposed action.
                     The barrier landforms to the east of the Mississippi River delta (coastal Subarea C4) are. not dependent
                 on a fluvial source of sand. Rather, these islands appear to be nourished by the sandy barrier platforms
                 beneath them (Otvos, 1980). Reduced discharges of fluvial sediment into the coastal zone will not affect these
                 barriers.
                     Oil spill contacts to barrier landforms can occur from a number of sources. This analysis considers spills
                 in three size categories: greater than I and less than or equal to 50 bbl; greater than 50 and less than 1,000
                 bbl; and greater than or equal to 1,000 bbl. Spills from offshore and onshore sources will be considered.










                                                                                                                          IV-285

                   A few spills greater than 1 @ and less than or equal to 50 bbl are assumed to occur offshore and contact
                barrier features as a result of OCS Program activities. As discussed in Section IV.D.La.(I)(a), as much as 35
                bbl of oil from such a spill could contact a coastal barrier along a 2-km stretch of beach. Cleanup crews are
                expected to remove the oil from the beach manually with no resulting removal of sand from the littoral
                environment No spill greater than 50 and less than 1,000 bbl is assumed to occur and contact barriers. The
                offshore occurrence of seven spills greater than or equal to 1,000 bbl is assumed to occur as a result of OCS
                Program activities. According to Table IV-21, the probability of occurrence and contact within 10 days from
                one or more spills grater than or equal to 1,000 bb ranges from 52 percent along the West Plaquemines Parish
                coastal barriers to less than 0.5 percent for Gulf Shores barrier islands. Based on the probabilities in these
                tables, this analysis assumes one contact will occur along the Plaquemines Parish coast, one along the Grand
                Isle/Grand Terre barrier coast, and one along the Chenier Plain coast. The spill in Plaquemines Parish Will
                contact the coast within 3 days; the other spills will contact within 10 days. The median size of these spills is
                6,500 bbl.
                    Assuming a 70 percent loss from weathering and offshore cleanup efforts for spills making contact within
                10 days, 1,950 bbl of oil will contact the coast Assuming that the percent of this oil along the coast that
                contacts a barrier feature is proportional to the ratio of barrier beach to barrier passes along the coast, about
                two-thirds of the oil will contact a beach. It is assumed that about 50 km of beach will be contacted with 1,300
                bbl of oil. For the spill that contacts within three days, assuming a 40 percent loss of oil from weathering and
                offshore cleanup, as much as 2,600 bbl of off could contact the beach. As discussed in Section IV.D.La.(1)(a),
                the probability that tide levels could reach or exceed the elevations of sand dune vegetation on barrier beaches
                ranges from 0 to 16 percent, depending on the particular coastal setting and the elevation of the vegetation.
                The combined probabilities of occurrence and contact from a spill and contact to sand dune vegetation at the
                spill sites being considered range from 2 to 8 percent. This analysis assumes that no sand dune vegetation will
                be contacted by spilled off in any the three spills being considered. Furthermore, the strong onshore winds that
                would be needed to produce unusually high tide levels would disperse and spread the slick over a larger area
                than is being considered in the current analysis. The spreading would reduce the oil concentration along the
                coast and the unit area impacts to vegetation, assuming a direct relationship between off concentration and
                effects on vegetation.
                    Impacts to contacted beaches from these spills could occur if sand were removed during cleanup
                operations. Removing sand from the coastal littoral environment, particularly in the sand-starved transgressive
                setting of coastal Louisiana, could result in accelerated coastal erosion. Cleaning these spins would be difficult
                in the inaccessible setting of coastal Louisiana. This analysis assumes that the State would require, however,
                that the responsible party clean the beach without removing the contacted sand, or by replacing whatever sand
                was removed, regardless of the specialized equipment and crews that would be needed to accomplish the task.
                    It is assumed that the cleanup operations would be accomplished with no permanent effects on the stability
                of the coastal landform. Some short-term (up to a few months) adjustments in beach configuration may result
                from the disturbance and movement of sand during cleanup. Some of the oil that penetrated to depths
                beneath the reach of the cleanup methods would persist in the beach sands, and periodically be released when
                storms and high tides flushed through the beach sediments.
                    Onshore spills could also occur from OCS operations and contact coastal barriers. These spills could occur
                as a result of pipeline accidents and barge or shuttle tanker accidents during transit or offloading. Most oil
                terminals are located inland from barrier islands, so an accident there would not likely result in contact to a
                barrier feature. A barge or shuttle tanker accident in transit could occur as the vessel approached or was
                traveling through a barrier pass, or while the vessel was travelling through the Intracoastal Waterway after
                entering coastal waters and making the final approach to the terminal. Under this scenario, it is more likely
                that a spill will contact the lagoonal, rather than the ocean side, of a barrier beach.
                    This analysis assumes that about 35 spills greater than 1 and less than or equal to 50 bbl, 5 spills greater
                than 50 and less than 1,000 bbl, and one spill greater than or equal to 1,000 bbl will occur onshore as a result
                of OCS Program activities. The assumption, based on an analysis of historic spill locations, which have been
                concentrated in the Mississippi River area, is that only a few contacts to barrier landforms will occur, resulting
                in 10 to 50 kin of back barrier coast contacted. Because of the low energy environment of this setting, cleanup
                will be accomplished without erosion or alteration of the island configuration.










                  IV-286

                       Non-OCS spills can occur as a result of import tankers, tidelands oil activities, and petroleum product spills.
                  It is assumed that numerous spills greater than I and less than or equal to 50 bbl and greater than 50 and less
                  than 1,000 bbl will occur and contact the ocean and land sides of barrier islands. Most of these spills will result
                  in only small amounts of oiling that may not be noticed in more remote and inaccessible setthigs. One hundred
                  and ten crude oil and product spills greater than or equal to 1,000 bbl, averaging 7,000 bbl each, are assumed
                  to occur during the life of the proposed action from offshore and onshore sources. Nurrierous contacts to
                  barrier beaches are expected. The same assumptions about impacts to beaches from cleanup operations that
                  were used for OCS spills apply here. Because of the heavier and more frequent oilings of beaches in this
                  scenario, compared to OCS spills, it is likely that cleanup operations will disturb and remove some sand, which
                  could result in short-term (up to two years) adjustments in beach configuration if the sand is not replaced and
                  regraded as a mitigation measure. Given the higher frequency of spill occurrence, and the heavier oilings from
                  onshore spills greater than or equal to 1,000 bbl, it is more likely that the lower elevations of some sand dune
                  vegetation will be contacted. An investigation of the effects of the disposal of offed sand on dune vegetation
                  in Texas showed no deleterious impacts on existing vegetation or colonization of the sand by new vegetation
                  (Webb, 1988). On this basis, it is assumed that contacts to small areas of lower elevated sand dunes will not
                  result in destabilization of the sand dune area or the barrier landform.
                      Of the 235 pipeline landfalls that have originated in Federal OCS and State waters in the area (Visual No.
                  1), many have occurred on barrier landforins. A recently completed MMS study has investigated the
                  geologic, hydrologic, and botanical impacts of pipeline emplacement on barrier landfornis in the Gulf (Wicker
                  et al., 1989). In general, the impacts of pipeline landfalls were minor to nonexistent. In most cases, there was
                  no evidence of accelerated erosion in the vicinity of the canal crossings. Wicker et al. (1989) warn, however,
                  that the potential for future breaching of the shoreline remains at the site of the flotation canal crossings
                  because the width is small, the sediments beneath the sand-shellbeach plugs are unconsolidatedand susceptible
                  to erosion and, in most cases, the width of the marshland and beach beside the canals is diminishing because
                  of Gulf and bay erosion. No pipelines cross barrier features along Mississippi Sound.
                      The addition of up to three new pipeline landfalls in the area is assumed to result from. prior OCS sales.
                  These landfalls are expected to occur in the Mobile, Alabama, area. The State of Alabarna has formulated
                  a plan for the transportation of oil and gas in its coastal area; the plan identifies barrier islands as unsuitable
                  areas for pipeline crossings (Marine Environmental Sciences Consortium, 1981). These new projected landfalls
                  will therefore not cross barriers. If, because of unanticipated discoveries, new landfall events occur elsewhere,
                  current environmental regulations and pipeline emplacement techniques are sufficient for mj'mt'mizm'g pipeline
                  project impacts (LeBlanc, 1985).
                      The construction and maintenance of navigation canals through barrier island passes can impact the
                  surrounding landscape. Stabilization of these channels with jetties can interfere with longshore sediment
                  transport, resulting in the accumulation of sediments on the updrift side of the jetty and erosion on the
                  downdrift side. Penland and Boyd (1982) have documented shoreline accretion updrift from jetties constructed
                  in the Belle Pass area, but accelerated erosion downdrift from the jetties. Wicker et al. (1989) have also
                  investigated navigation canal impacts, concluding that channels have affected coastal physiography mainly
                  through the action of jetties, which block the downdrift movement of sediment. At Belle Pass, however, they
                  noted that the downdrift erosional effects of the jetty disappeared when maintenance-dredged material was
                  discharged into the littoral zone downdrift from the jetty. During the life of the proposed action, it is assumed
                  that beneficial use of dredged material will increase, thereby reducing the ongoing impacts of navigation
                  channels. Impacts from existing channels are expected to result in some accelerated erosion immediately
                  downdrift of the channel.
                     No new navigation canals are expected to be installed during the next 35 years. The basis of this
                  assumption is the large number of existing navigation channels that can accommodate further navigation needs.
                     Section IV.A.3.c.(3)(c) states that the channel leading to Port Fourchon, Louisiana (Belle Pass), will be
                  deepened to 6.7 m (22 ft) to provide access for larger service vessels used for deep-water operations. It is
                  assumed that 90 percent of the impacts of this project can be attributed to OCS Program scenario activities.
                  Wicker et al. (1989), as discussed above, have studied the effects of navigation channel dredging and
                  maintenance operations on coastal processes, and at Belle Pass in particular. Prior to the dredging of the
                  channel to Port Fourchon, and the construction of jetties at the channel entrance, the coast east (updrift) of










                                                                                                                             IV-287

                the channel was retreating at a. rate of 40 m/yr, compared to 31 m/yr west (downdrift) of the channel. The
                difference in retreat rates (30 percent higher to the west) can perhaps be attributed to the channel's acting as
                a sediment sink in this predominantly east-to-west littoral drift environment. After dredging and jetty
                construction, the difference between the east and west erosion rates increased to 50 percent, although the
                magnitude of the retreat rate decreased by nearly one-half. In 1974, the Corps of Engineers (COE) began to
                use material from maintenance dredging operations in Belle Pass to nourish the beach areas west of the
                channel. Since then, no significant difference between east and west erosion rates has been observed, and the
                absolute erosion rate has decreased by about another one-half. The COE's feasibility report for the Belle Pass
                deepening project indicates that some of the dredged material can be used for beach nourishment (U.S. Dept.
                of the Army, COE, 1991). Therefore, no increase in ongoing erosion rates of barrier islands and beaches is
                expected as a result of channel deepening.
                     Efforts to stabilize the Gulf shoreline have impacted barrier landscapes. Stabilization projects in the
                cumulative impact area have been mainly along the Louisiana coast. Structures constructed to stabilize the
                beach by fixing its location expose the landform to the erosive effects of a rising relative sea level. The impacts
                of beach stabilization projects are difficult to quantify in coastal Louisiana. The negative impacts of fixed
                structures are being offset to some extent by nonstructural approaches such as sand dune stabilization and
                beach nourishment projects. Furthermore, coastal barriers are eroding so rapidly in Louisiana as a result of
                alterations of the sedimentary dynamics of the Mississippi River deltaic system and the high coastal subsidence
                rates that it is difficult to isolate the impacts of coastal structures.
                     Most barrier beaches in Louisiana and Mississippi are relatively inaccessible for recreational users either
                because they are located at a substantial distance offshore, as in Mississippi, or in coastal areas with limited
                road access, as in Louisiana. Few beaches have been, or are likely to be, substantially altered for construction
                projects to accommodate recreational users. Further, damage to dune vegetation and other sensitive beach
                areas from recreational users, such as dune buggy operators or hikers, has not been, and will not likely be,
                significant in most cases.

                Summary

                     Sediment reduction and rapid submergence have resulted in rapid erosion of most of the barrier landforms
                along the Louisiana coast. The impact level from these factors is expected to be very high in Louisiana. In
                Mississippi and Alabama, most of the barrier islands are supplied with an offshore source of sand and are not
                affected by sediment deprivation.
                     Several spills greater than or equal to 1,000 bbl from both onshore and offshore sources and several
                smaller spills are assumed to contact coastal barriers. The impacts of these spills along the sand-starved
                Louisiana coast would not result in long-term erosion of the landform. if the beaches are cleaned using
                techniques that do not remove sand from the beach. Some contact to lower areas of sand dunes are assumed.
                These contacts will not result in destabilization of the dunes.
                     Pipeline landfalls have been examined as possible sites of accelerated shore erosion and island breaching.
                A recently completed, MMS-funded study of pipeline landfall impacts (Wicker et al., 1989), however,
                documented little to no impacts of pipeline landfalls. The study did note, however, that pipeline landfalls could
                be future sites of island breaching.
                     Three new pipeline landfalls are projected under the Cumulative scenario: one in Pascagoula, Mississippi;
                and two in Mobile, Alabama. In addition, new pipeline landfalls may be installed to transport production from
                State waters to land. Modern pipeline installation techniques that do not result in noticeable impacts to coastal
                habitats will be used. Furthermore, the States of Alabama and Mississippi have established management plans
                for oil and gas development that do not allow pipeline landfalls across barrier islands.
                     Wicker et al. (1989) have documented localized, accelerated erosion updrift from jetties installed to
                stabilize navigation channels. The impact level from this factor is expected to be reduced as a result of
                beneficial use of dredged material.
                     Beach stabilization projects, such as groins, jetties, and seawalls, are considered to cause accelerated coastal
                erosion. Although the impacts of fixed structures on the erosion of the Louisiana barrier coast have not been
                precisely quantified, coastal researchers have observed localized erosion near various kinds of coastal structures.










                 IV-288

                     Recreational usage of beaches in the Central Gulf is not expected to result in impacts because of the
                 inaccessil3ility of the barrier coast to humans.
                     Between 1880 and 1980 the total coastal barrier area in Louisiana decreased by over 40 percent, or 0.4
                 percent per year (Penland and Boyd, 1982). Recent estimates of loss rates vary from about 3 percent per year
                 for the Isles Dernieres to under 0.5 percent per year for the Chandeleur Islands (Penland ELnd Suter, 1988).
                 Impacts on barriers should continue because most of the impacting factors have not been effectively mitigated.
                 Although public concern over barrier erosion in Louisiana has increased in recent years, a program to
                 significantly reduce cumulative impacts during the next few decades has not been formulated. Impacts on the
                 barrier islands offshore Mississippi and Alabama are expected to be insignificant except for the eastern side
                 of Dauphin Island, which is experiencing rapid erosion.
                     The contribution of OCS activities associated with the Cumulative scenario to coastal barrier beach impacts
                 is expected to be very low because oil-spill cleanup operations, pipeline landfalls, and navigation channel
                 deepening and maintenance projects will not result in large amounts of barrier beach changes.

                 Conclusion

                     Under the Cumulative scenario, the observed erosional trend of barrier features is expected to continue
                 in onshore Subareas C-1, C-2, and C-3. The major causes of these impacts are sediment deficits and rapid
                 rates of relative sea-level rise.

                 (b) Wetlan&

                     This Cumulative Analysis considers the effects of impact-producing factors related to the proposed action,
                 plus those related to the Western Gulf proposed action, prior and future OCS sales, tideland oil and gas
                 activities, other governmental and private projects and activities, and pertinent natural processes and events
                 that may occur and adversely affect wetlands. As a result of these activities and processes, several impact-
                 producing factors, discussed below, will contribute to impacts on wetlands during the life of the proposed
                 action.
                     The effects of oil spills, produced-water discharges, canal dredging, navigation activities, and onshore
                 infrastructure on wetlands have been described in the Base Case Analysis (Section IV.D.La.(1)(b)). Other
                 impact-producing factors relevant to the Cumulative Analysis are discussed below.
                     In a coastal setting experiencing submergence, the wetland surface must accrete vertically to keep pace with
                 the ongoing rate of relative sea-level rise. Mineral sedimentation is needed to encourage this vertical accretion.
                 In coastal Louisiana, the Mississippi River and its distributaries are the primary sources of alluvial sediments
                 for coastal wetlands. The suspended sediment load of the Mississippi River has decreased over 50 percent
                 since the 1950's, largely as a result of dam and reservoir construction upstream (Turner and Cahoon, 1987).
                 Furthermore, channelization of the lower Mississippi for navigation and flood control has prevented floodwaters
                 from depositing sediment on adjoining wetlands.
                     The channelization of the Mississippi River also affects seagrass beds in Mississippi and Chandeleur
                 Sounds. During high water stages of the river, the Bonnet Carre spillway is sometimes opened to divert
                 floodwaters of the Mississippi River into Lake Pontchartrain. This freshwater eventually flow.; into Mississippi
                 and Chandeleur Sounds. In the past, spillway openings have been associated with as much as a 16 percent loss
                 in seagrass acreage (Eleuterius, 1987).
                     The negative impacts of sediment deprivation on coastal wetlands are compounded by rapid submergence
                 rates that characterize much of the area, and coastal Louisiana in particular, where the coastal submergence
                 rate ranges from 3 to 10 mm/yr.
                     Additional impacts to wetlands occur from activities associated with State onshore oil and gas activities and
                 from land development for agricultural, urban, and commercial projects
                     Sediment deprivation, combined with rapid coastal submergence, will continueas a major impact-producing
                 factor during the life of the proposed action, and in coastal Louisiana in particular. Expert consensus is that
                 sediment deprivation and submergence are the major factors that have caused up to 130 kM2        year of land loss










                                                                                                                             IV-289

                 in coastal Louisiana. Current estimates of land loss in coastal Louisiana are 60 kM21yr on the Deltaic Plain
                 (Britsch and Kemp, 1990) and 21 km2/yr on the Chenier Plain (Dunbar et al., 1990).
                     Oil spill contacts to wetlands can occur from a number of sources. This analysis considers spills in three
                 size categories: greater than I and less than or equal to 50 bbl; greater than 50 and less than 1,000 bbl; and
                 greater than or equal to 1,000 bbl. The effects of oil spills on wetlands under the Cumulative scenario will be
                 evaluated for OCS Program spills and for imported/onshore crude and petroleum products spills. Spills from
                 offshore and onshore sources will be considered.
                     A few spills greater than I and less than or equal to 50 bbl are assumed to occur offshore and contact
                 wetlands as a result of OCS Program activities. Because of evaporation losses, spreading considerations, and
                 the fact that much of the remaining oil will wash onto barrier beaches that front the coast, contact from these
                 spills is not expected to result in high-enough concentrations of oil (greater than 0. 1 I/M2) on wetland surfaces
                 to affect wetland vegetation adversely. None of the oil is expected to contact seagrass beds located behind
                 barrier islands. No spill greater than 50 and less than 1,000 is assumed to occur and contact barriers. The
                 offshore occurrence of seven spills greater than or equal to 1,000 bbl is assumed to occur as a result of OCS
                 Program activities. According to Table IV-21, the probability of occurrence and contact within 10 days from
                 one or more spills greater than or equal to 1,000 bbl is a maximum (49%) along the East Deltaic Plain
                 mar 'shes. Given the probabilities in these tables, this analysis assumes two contacts will occur along the East
                 Deltaic Plain, and one along the Chenier Plain coast. The spills along the East Deltaic Plain will contact the
                 coast within 3 days; the other spill will contact the Chenier Plain within 10 days. The median size of these spills
                 is 6,500 bbl.
                     Assuming a 70 percent loss from weathering and offshore cleanup efforts for spills making contact within
                 10 days, 1,950 bbl of oil will contact the coast. Assuming that one-third of the oil that reaches the coast will
                 move through barrier passes and estuaries and contact wetlands, approximately 650 bbl of oil will be spread
                 across 25 kin of shoreline and penetrate 20 in into the wetlands.
                     The resulting average oil concentration will be 0.20 I/M2 contacting the wetlands within a 50 ha contact
                 area. For the spills that contact within three days, assuming a 40 percent loss of oil from weathering and
                 offshore cleanup, as much as 1,300 bbl of oil could contact wetlands. These spills will result in higher
                 concentrations of oil on the vegetation and a larger area of contact than in the above case. Given the
                 assumptions described in Section IV.D.La.(1)(b), the approximately 150 ha (60 ac) contacted by the three spins
                 will result in up to 50 or more hectares of wetland vegetation experiencing above-ground dieback or mortality.
                 As much as 20 ha will recover within four years, with an eventual permanent loss of 15 ha of wetlands as a
                 result of conversion to open water. Some additional permanent wetlands loss may occur along the shoreline
                 as a result of accelerated erosion induced by weakening of the vegetation that binds the soil.
                     Onshore spills could also occur from OCS operations and contact coastal wetlands. These spills could
                 occur as a result of pipeline accidents and barge or shuttle tanker accidents during transit or offloading. This
                 analysis assumes that about 35 spills greater than 1 and less than or equal to 50 bbl, 5 spills greater than 50
                 and less than 1,000 bbl, and 1 spill greater than or equal to 1,000 bbl will occur onshore as a result of OCS
                 Program activities. Because these spills are assumed to occur close to or within wetland areas a proportionately
                 larger percentage of oil could contact wetlands than was the case for offshore spills. Spill occurrences that will
                 most likely result in a high percentage of the oil's contacting wetlands will be pipeline accidents within wetlands
                 and in-transit barge/shuttle tanker accidents within navigation channels that do not have prominent spoil banks
                 to confine the oil within the channel. It is assumed that a few of these spills of varying size will contact
                 wetlands, resulting in up to 50 ha of wetland vegetation being affected as described in the previous paragraph,
                 and up to 5 ha of permanent wetland loss.
                     Non-OCS spills can occur as a result of import tankers, tidelands oil activities, and petroleum product spins.
                 It is assumed that numerous spills greater than 1 and less than or equal to 50 bbl and greater than 50 and less
                 than 1,000 bbl will occur and contact wetlands during the life of the proposed action. Most of these spins will
                 result in only small amounts of oiling that may not be noticed in more remote and inaccessible settings. One
                 hundred and ten crude oil and product spills greater than or equal to 1,000 bbl, averaging 7,000 bbl each, are
                 assumed to occur during the life of the proposed action from offshore and onshore sources. Many of these
                 spills are assumed to occur within the Mississippi River. These spills will be confined within the channel and
                 diluted by the discharge of the river. Still, several contacts to wetlands are expected. Because these spills will










                 IV-290

                 be larger on average than coastal OCS-related spills, and will result in heavier oiling than was the case for
                 contact from offshore OCS spills, it is assumed that as much as 500 ha of wetlands could be affected over the
                 life of the proposed action, and up to 50 ha of wetlands could be permanently converted to open water.
                     Under the Cumulative scenario, spills that occur in or near Chandeleur or Mississippi Sounds could
                 potentially contact seagrass beds. Spills in these areas could result from accidents involving import tankers and
                 barges travelling to refineries and oil storage facilities in coastal Subarea C4 and from pipeline spins. A large-
                 diameter oil pipeline traverses Chandeleur and Mississippi Sounds. Small spills could occur as a result of
                 tanker, barge, and pipeline accidents, as in September 1989, when about 100 bbl of oil spilled from a pipeline
                 in Mississippi Sound.
                     As discussed in the Base Case analysis (Section IV.D.La.(I)(b)), oil-spill impacts to seagrasses are usually
                 buffered by the subtidal position of seagrasses, resulting in the absence of direct contact to the seagrass
                 vegetation in subtidal beds. Furthermore, because so much of the seagrass biomass is conta@[ned in roots and
                 rhizomes, which are buried in sediment, seagrasses have a high regenerative capacity when, their vegetative
                 parts are contacted by oil. Seagrass beds, however, occur at shallow depths, generally less than 50 cm, creating
                 some vulnerability to contact from oil mixed into shallow estuarine waters. Given the large number of potential
                 spills from pipeline and barge accidents in and near Chandeleur and Mississippi Sounds, it is assumed that
                 several contacts to seagrass beds will occur and will result in dieback to the grass vegetation, which win be
                 replaced for the most part within one growing season. Although no to little direct permanent mortality of grass
                 beds is expected as a result of oil-spill occurrences, contact of seagrasses with crude and refined oil has been
                 implicated as a causative factor in the decline of seagrass beds and the observed changes in species composition
                 within them (Eleuterius, 1987).
                     Another effect of the occurrence of spills in Mississippi Sound is possible contacts to we'aands on barrier
                 islands within the Gulf National Seashore. These wetlands occur within embayments and ponds that contact
                 Mississippi Sound. Because of their natural history, these areas are considered areas of special importance,
                 and they support endangered and threatened species. Although the wetland acreage on these islands is small,
                 these wetlands make up an important element in the habitat of the islands. Because the inlets that connect
                 Mississippi Sound with the marsh-fringed estuaries and lagoons within the islands are narrow, only a small
                 percentage of the oil that contacts the Sound side of the islands will be carried by the tides into interior
                 lagoons. Because only spills less than 1,000 bbl are assumed to occur in these locations, the amount of oil that
                 would finally contact wetlands would be relatively small and would not result in high-enough concentrations
                 to affect wetlands deleteriously except in small isolated areas where oil tended to become concentrated, and
                 in isolated locations.
                     According to Table IV-10, over 2.4 Bbbl of produced waters will be disposed of in coastal Louisiana.
                 These produced waters will either be reinjected or discharged into offihore State waters or into the Mississippi
                 River and its passes. Field studies have documented no impacts to wetland vegetation under these disposal
                 conditions (Boesch and Raba", 1989b). It is therefore assumed that produced-water discharges will not affect
                 wetland vegetation.
                     The dredging of pipeline and navigation canals for oil and gas operations has had impacts on wetlands in
                 coastal Louisiana. Although no dredging activity for new navigation channels is anticipated under the
                 Cumulative scenario (Table IV-9) and only a small amount of dredging for new pipeline landfalls is expected,
                 the lingering indirect impacts of existing channels have to be considered.
                     Indirect impacts from canals associated with the OCS program have been estimated as accounting for 4
                 to 13 percent of the total amount of wetland loss that occurred in coastal Louisiana between 1955-1956 and
                 1978 (Turner and Cahoon, 1987). Turner and Cahoon calculated this range by dividing the. length of OCS
                 canal spoil banks by the length of all canal spoil banks (OCS, State onshore oil and gas, general navigation,
                 and drainage canals), and then multiplying this proportion by the range of estimates of the: contribution of
                 indirect impacts to wetlands loss. They assumed that the proportion of OCS spoil banks could be used as a
                 direct surrogate of the proportion of indirect impacts.
                     The MMS does not consider this method of indirect impact determination acceptable for use as a basis
                 for the Cumulative Analysis. This conclusion is based on two considerations. First, the adculation of the
                 proportion of indirect impacts was based on untested and inaccurate assumptions and, second, their method










                                                                                                                            IV-291

                 did not incorporate the data that had been collected and analyzed in the body of the study, even though the
                 data were relevant to the issue.
                     Concerning the first point, MMS questions the numbers as they were derived by Turner and Cahoon
                 (1987). As stated by the authors, OCS spoil banks may have been overestimated in their calculations because
                 OCS canals and spoil banks tend to be large and thus more visible on remote-sensing imagery. Further, the
                 Turner and Cahoon study only produces a number for the length of OCS canals. The length of all spoil banks
                 '(the number in the denominator of their proportion) is not revealed within the study, nor is the methodology
                 that was used to calculate the length of all spoil banks indicated. Furthermore, the study defined indirect losses
                 as all wetland losses occurring in the State minus the direct losses attributable to canal dredging and
                 urban/residential/agriculturaldevelopment. The contribution of sediment deprivation and subsidence were not
                 accounted for in either of these categories, even though many researchers believe these factors to be the most
                 important cause of wetlands loss in the area. Turner and Cahoon (1987), in essence, inappropriately allocated
                 a proportion of the impacts of sediment deprivation on wetland loss to the indirect impacts of OCS canals.
                 Consequently, MMS cannot validate the accuracy of the study's apportionment of indirect impacts to OCS
                 canals.
                     In addition, the data that had been generated from field, laboratory, modeling, and remote-sensing analysis
                 efforts in the study were not used in developing the indirect impact proportion number, even though much of
                 the data were relevant to the issue. For example, the study hypothesized that the indirect impacts of canals
                 could affect wetlands through the influence of canals on saltwater intrusion and through the influence of
                 associated spoil banks on sedimentation and drainage patterns. The study data, however, did not confirm this
                 hypothesis. The data, for example, did not document a relationship between saltwater intrusion and marsh loss
                 and did not show a statistically valid correlation between proximity to spoil banks and vertical rates of marsh
                 accretion. The computer analyses of remote-sensing imagery did not establish a statistically valid relationship
                 between either canal density or proximity to a canal and marsh loss. Rather, the study documented a greater
                 than 50 percent reduction in the suspended sediment discharge of the Mississippi River since the 1950's and
                 a widespread accretionary deficit within the wetlands of coastal Louisiana. These results, which did not confirm
                 the hypothesized mechanisms of indirect wetland loss but suggested an emphasis on sedimentary deficits and
                 subsidence as mechanisms for marsh loss, were not brought into the methodology for assessing OCS indirect
                 impacts.
                     To conclude, the OCS canal indirect impact numbers derived in the study were not based on the body of
                 data generated by the study, but were instead developed using an indirect and incomplete approach that could
                 have been done even in the absence of the study. The MMS considers the Turner and Cahoon estimates to
                 be no more reliable or better supported by field data than any of the other attempts in the past to estimate
                 the role of indirect impacts.
                      One consideration in assessing indirect impacts of the OCS program is that 77 percent of all OCS-related
                 pipeline canals have been backfilled (Turner and Cahoon, 1987). Backfilling, by partially filling in the canal
                 cut and by levelling spoil banks, should greatly reduce indirect impacts. Furthermore, OCS-related vessel traffic
                 accounts for only a small percentage of the commercial usage of major navigation routes through coastal
                 Louisiana. Of 7,866 kin (4,886 mi) of coastal navigation routes, only 330 kin (205 mi), or 4 percent, are
                 allocated to OCS traffic.
                      Most of the canalization that has occurred in coastal Louisiana has occurred as a result of onshore oil and
                 gas activities. An indication of the extent of this activity is provided by well completion data: approximately
                 41,190 wells had been completed in coastal Louisiana as of 1984 (USDOI, GS, 1984). Access canals and
                 pipelines to service onshore development are pervasive throughout the coastal area: 15,285km(9,498mi)of
                 pipeline canals have been installed there to carry onshore production. According to the U.S. Army Corps of
                 Engineers, in 1988 that agency received applications for the installation of 123 kin (76 mi) of pipelines through
                 wetland areas. The average direct impacts from backfilled pipeline canals in coastal Louisiana arc 0.91 ha/km.
                 If 123 kin of pipelines are installed each year during the 35 years of the proposed action, the direct impacts
                 from pipeline projects would be approximately 4,000 ha. This estimate, however, is probably high because
                 tidelands oil and gas activities are expected to decline during the life of the proposed action.
                      Drilling and production activity at coastal well sites requires rig access canals. Typical dimensions of an
                 access canal, as indicated on permits, are 366 in long by 20 in wide with a 0.5 ha drill slip at the end. In 1988,










                 IV-292

                 the COE receiveA applications for the dredging of over 11 kin of access canals. Assuming this level of activity
                 persists over the life of the proposed action, the direct impacts from the permitted dredging will be the
                 conversion over 750 ha of wetlands to open water, with additional wetland acreage buried by spoil banks along
                 the channel margins. In addition to these direct impacts, the ongoing indirect impacts from this pervasive and
                 growing network of pipeline and navigation canals will continue to produce impacts on wetlands in coastal
                 Louisiana (coastal Subareas C-1, C-2, and C-3).
                     Under the Cumulative scenario, there will be three new pipeline landfalls in coastal Subarea C4, which
                 includes Mississippi and Alabama (Table IV-10). One of these landfalls is assumed to occur in coastal
                 Mississippi and two in coastal Alabama. Assuming that these pipeline canals will be backfilled, that proper
                 precautions will be taken to reduce environmental impacts, and that there will be a 16-kin length per pipeline
                 landfall, impacts to surrounding wetlands, if the pipelines traverse wetland areas, would be about 33 ha, using
                 the impact rate of 0.68 ha/km in Mississippi/Alabama (Turner and Cahoon, 1987). No new dredging of
                 navigation channels in the area is projected.
                     As discussed in Section IV.A.3.c.(3)(c), OCS activities in deep water are requiring larger service vessels
                 for efficient operations. Currently, service bases in Galveston, Texas, and Berwick, Louisiana, are accessible
                 to the larger vessels; and Empire and Cameron, Louisiana, are considered marginally useable. This document
                 assumes that the channel through Belle Pass, Louisiana, to Port Fourchon will be deepened. to 6.7 in (22 ft).
                 The Corps of Engineers has completed a feasibility report for the project (U.S. Dept. of the Army, COE, 1991).
                 According to the report, dredged material from the channel will be disposed of in wetland areas to enhance
                 marsh creation. The COE projects that 192 ha (479 ac) of saline marsh win be created. Assuming that 90
                 percent of the justification of the project is for OCS activities, 173 ha (431 ac) of wetlands will be created as
                 a result of OCS Program activities. The COE does not anticipate saltwater intrusion effects on wetlands as
                 a result of the deepening project, probably because the project will be done in a saline environment where the
                 existing vegetation is salt-tolerant.
                     Vessel usage of existing navigation channels creates wakes that can cause erosion of the wetlands along
                 channel margins. According to Johnson and Gosselink (1982), channels with high navigational usage in coastal
                 Louisiana widen about 1.5 m/yr more rapidly than channels that have little navigational usage (2.58 m/yr versus
                 0.95 m/yr). Based on these results, this analysis assumes that navigational usage is responsible for 1.5 m/yr of
                 accelerated wetland erosion per meter of channel where wetlands fringe waterway. An idea of the contribution
                 of OCS oil and gas activities to accelerated channel bank erosion is provided in Table IV-12, which projects
                 that over 700,000 service vessel and 6,800 barge trips will take place under the Cumulative scenario during the
                 life of the proposed action. Under the Cumulative scenario, it is assumed OCS activities account for 12
                 percent of all vessel usage within the major navigation channels in the CPA. The 21 channelLs associated with
                 OCS activities in the CPA are listed in Table IV-2. Assuming that the average OCS facility is located 24 kin
                 from the coastline and that 50 percent of the channel length is fringed with wetlands, the aritiount of wetland
                 erosion that could occur from OCS traffic under the Cumulative scenario is 2.25 ha/yr, or nearly 80 ha over
                 the life of the proposed action.
                    The erosion effects of all other (non-OCS) traffic in these channels are difficult to calculate because the
                 OCS figure is based on the first 24 kin of the channel. The total navigable length of these channels for general
                 navigation purposes has not been calculated. Given, however, that OCS traffic accounts for only 12 percent
                 of the traffic, erosion caused by general navigation will be at least eight times greater, or 640 ha over the life
                 of the project.
                    In addition to the widening of the major navigation channels at the expense of wetlands., widening of rig
                 access canals for State onshore oil and gas activities causes considerable impacts each year. Because of the
                 smaller amount of vessel usage of these single purpose channels, it is assumed that the lower widening rate of
                 0.95 m/yr occurs in these channels (Johnson and Gosselink, 1982). As mentioned above, in 1988 applications
                 for dredging 11 kin of these access canals in coastal Louisiana were submitted to the U.S. Army Corps of
                 Engineers. Assuming that this number applies to each of the 35 years of the life of the proposed action, and
                 that the canals widen at the same rate each year, over the life of the proposed action nearly WO ha of wetlands
                 will be eroded.
                    Maintenance dredging of existing channels can also contribute to wetland problems. In 1988, the U.S.
                 Army Corps of Engineers received applications for permits for maintenance dredging along 130 km of existing










                                                                                                                         IV-293

                rig access channels and drill slips for State onshore oil and gas activities in Louisiana. These activities
                generated approximately 4,500,000 m3   of dredged material, 82 percent of which was disposed of onto existing
                spoil banks.
                    Data on maintenance dredging in major Gulf waterways for OCS and general navigation are being
                compiled, but are not available for this EIS. In general, it is assumed that major Gulf waterways will be
                maintenance-dredged every one or two years. This analysis assumes that, during the life of the proposed
                action, dredged material will be increasingly used to enhance marsh growth in deteriorating wetland areas. This
                policy will reduce the damaging effects of maintenance dredging.
                    No new onshore infrastructure is projected to be constructed in support of the OCS program in coastal
                Subareas C-1,C-2, and C-3 under the Cumulative scenario (Table IV-10). In C-4, two gas processing plants,
                two separation facilities, and one oil terminal are projected to be constructed. The gas processing plant and
                separation facilities are assumed to be constructed in a upland area of coastal Alabama. The oil terminal is
                assumed to be constructed in Jackson County, Mississippi, and will occupy about 15 ha. Some filling of
                wetlands may occur at the terminal site. It is assumed that an acre-for-acre replacement of the affected
                wetland will be required as a mitigation condition of the project.
                    Miscellaneous factors that impact coastal wetlands include marsh burning, marsh buggy traffic, onshore oil
                and gas activities, and well-site construction. Bahr and Wascom (1984) report major marsh burns that have
                resulted in permanent wetland loss. Sikora et al. (1983) reported that in one 16 kin  2welland area in coastal
                Louisiana, 18.5 percent of the area was covered with marsh buggy tracks. Well-site construction activities
                include board roads and ring levees. Ring levees are approximately 1.6-ha impoundments constructed around
                a well site. With 41,000 onshore coastal wells drilled in Louisiana as of 1984, the total acreage of impounded
                wetlands is substantial. Further, onshore oil and gas waste disposal practices can cause localized impacts in
                wetlands (Sections IV.A.4.e.(8)(b) and IV.B.2.b.). This analysis assumes that current landfill and waste site
                capacities can accommodate the onshore disposal of offshore wastes and that no new disposal sites will be
                constructed. Some damage to adjacent wetlands, however, is possible as a result of seepage from the waste
                sites.
                    Development of wetlands for agricultural, residential, and commercial uses affects wetlands in the area.
                During the period 1952-1974 in the Chenier Plain area of southwestern Louisiana, an estimated 1,233 ha of
                wetlands were converted to urban use (Gosselink et al., 1979). During the period 1956-1978, an estimated
                21,642 ha of urban or industrial development occurred in the Mississippi Deltaic Plain region of southern
                Louisiana (Bahr and Wascom, 1984).
                    The land use impacts on wetlands in coastal Alabama have been very high in recent decades. Major causes
                of estuarine wetland loss in Alabama include industrial and residential-commercial development. Loss of fresh
                coastal marsh was mainly attributable to commercial-residential development and silviculture (Roach et al.,
                1987). Between 1955 and 1979, fresh and estuarine marshes declined by 69 and 29 percent, respectively.

                Summary

                    Ile decrease in the amount of sediment being transported by the Mississippi River to coastal Louisiana
                will continue as a major factor causing wetland loss. Sediment deprivation is compounded by rapid
                submergence occurring along the coaSt. Flood control and channelization of the river will also result in
                freshwater diversions during flood stages into areas of seagrass beds. These diversions will result in very high
                impacts to seagrass beds.
                    Oil spills are expected to affect as much as 600 ha of wetlands during the life of the proposed action. The
                effects will be manifested as accelerated erosion of wetland shorelines and permanent loss of up to 70 ha of
                wetlands and as temporary (up to four growing seasons) dieback and reduced vigor of wetland vegetation.
                    No impacts to wetlands from produced-water discharges into coastal water bodies are expected to be occur.
                    Indirect impacts from new canal dredging for State onshore oil and gas development and from the
                continuing indirect impacts of the existing canal network are expected to continue. Furthermore, the
                disappearance of wetlands along navigation channels as a result of vessel wake erosion is expected to result
                in several hundred hectares of wetlands loss.










                 IV-294

                     Only minor amounts of new onshore infrastructure construction are projected under the Cumulative
                 scenario. These facilities are projected for coastal Subarea C4 and will likely be constructed on coastal
                 uplands, given the ample amounts of such land near the coast in Subarea C-4 and the regulatory difficulties
                 involved in construction projects on wetlands.
                     Impacts from State onshore oil and gas activities include new and maintenance dredging, existing rig access
                 canals, drill slips, and well-site preparation. Impacts from residential, commercial, and agricultural and
                 silvicultural developments are expected to continue in coastal Louisiana and Alabama.
                     The contribution of OCS activities associated with the Cumulative scenario to wetland impacts is expected
                 to be very low because of the small portion of the total impacts to wetlands that can be attributed to OCS
                 related spills, the small percentage of the vessel usage of navigation channels that can be attributed to OCS
                 activities, the small amount of expected new infrastructure construction in wetland areas, and the dominating
                 importance of sediment deprivation and submergence to the wetlands loss problem.

                 Conclusion


                     Under the Cumulative scenario, large losses of wetlands are expected to continue to occur. The main
                 cause of these losses, particularly in coastal Louisiana, where the largest amount of wetlands will be lost, is
                 sediment deprivation and rapid coastal submergence. Other contributing factors include tideland oil and gas
                 development, the erosion of navigation channel margins and, to a lesser extent, impacts from oil spills.
                 (2) Impacts on Sensftive Offshore Resources

                 (a) Live Bouorns (Pinnacle Trend)

                     This Cumulative Analysis considers the effects of impact-producing factors related to the proposed action
                 plus those related to prior and future OCS sales and tanker and other shipping operations that may occur and
                 adversely affect live bottoms associated with the pinnacle-trend area. Specific types of impact-1'iroducing factors
                 considered in the analysis include drilling rig, platform, and pipeline emplacement; well drilling (discharges);
                 hydrocarbon production (produced waters); blowouts; oil spillage; anchoring; and operational discharges by
                 tank ships. Non-OCS-related impacts, including fishing pressure, natural events, increased. anchoring from
                 pleasure boats, and spillage from import tankering, have the potential to impact the pinnacle communities.
                     Biological stipulations or comparable mitigation will be made a part of appropriate leases resulting from
                 this proposal. The stipulations force the operators to locate the individual pinnacles and associated
                 communities that may be present in the block. This procedure will help to protect those regions that may be
                 potentially impacted by OCS activities and, if so, require any appropriate mitigative measures. The biological
                 stipulations do not affect or protect the resources from activities over which the MMS has no authority (i.e.,
                 commercial fishing, tanker and shipping operations, or recreational activities).
                     Non-OCS activities have the greatest potential to affect the hard-bottom communities of the region.
                 Recreational boating and fishing, import tankering, and natural events (such as storm and hypoxic conditions)
                 may lead to damage and are a serious threat to the hard -bottom communities. The area of the pinnacle trend
                 is located near a major shipping fairway, and ships using this fairway into Mobile, Alabama, can be expected
                 to anchor in this area on occasion. Numerous fishermen also take advantage of the relatively shallow and easily
                 accessible resources of the region and are expected to anchor in these areas to fish. It is expected that several
                 instances of severe and permanent mechanical damage to the pinnacles and the low-relief live bottoms are
                 likely to occur as the result of the Cumulative scenario. It is projected that this damage to one or more
                 components of a few regionally common habitats or communities results in changes to physical integrity, species
                 diversity, or biological productivity that exceeds natural variability observed prior to the damage, and recovery
                 to pre-impact conditions takes longer than 10 years.
                     The placement of drilling rigs and platforms on the seafloor crushes the organisms directly beneath the
                 legs or mat used to support the structure; anchoring has the same effects. The areas affected by the placement
                 of the platforms and rigs will predominantly be soft-bottom regions where the infaunal and epifaunal










                                                                                                                             IV-295

                  communities are not unique. The presence of a conventional structure (some 117 platforms are assumed to
                  be constructed in offshore Subarea C-3) can cause scouring of the surficial sediments (Caillouet et al., 1981).
                  Additionally, it has been assumed that between 0.4 and 1.6 ha (I and 4 ac) of bottom may be disturbed by
                  platform emplacement activities alone. Structure placement and anchor damage from support boats and ships,
                  floating drilling units, and pipeline-laying vessels disturb areas of the seafloor and are the most serious threats
                  to live-bottom areas at these depths. The size of the areas affected by chains will depend on depth of water,
                  length of chain, size of anchor and chain, method of placement, wind, and current The biological stipulations
                  limit the proximity of new activities in the hard-bottom region. For this reason, the damage from support boats
                  and ships would be minimal. The impact from rigs and associated anchors on the hard-bottom communities
                  of the region as a result of the proposed action would be such that any changes in the regional physical
                  integrity, species diversity, or biological productivity of the hard-bottom region would recover to pre-impact
                  conditions in less than two years, more probably on the order of 2-8 weeks.
                     Both explosive and nonexplosive structure-removal operations disturb the seafloor and can potentially affect
                  nearby hard-bottom communities. Structure removal using explosives (the most common removal method) can
                  suspend sediments, which settle much in the same manner as discussed for muds and cuttings discharges.
                  Charges used in OCS structure removals are typically 50 lb or less, and detonated five meters below the
                  mudline, thus restricting impacts to very close to the structure being removed (USDOI, MMS, 1987a). As
                  previously discussed, the platforms will not be constructed directly on the hard-bottoms because of the
                  biological stipulation. Impacts to the hard-bottom area from structure removal are expected to be minimal
                  because of the restricted regions affected by the shock from explosives and the low number of structures likely
                  to be placed (and subsequently removed) in such regions. The impact of a structure removal would be such
                  that it would not result in any changes in the regional physical integrity, species diversity, or biological
                  productivity, and hard-bottom region would recover to pre-impact conditions in less than two years, more
                  probably on the order of 4-8 weeks.
                      Drilling discharges affect biological communities and organisms through a variety of mechanisms.
                  Smothering of organisms through deposition of these sediments may occur, or less obvious sublethal effects may
                  take place. Oil and gas operations will routinely discharge drilling muds and cuttings. (Some 26 MMbbI of
                  drilling muds and 6 MMbbI of drill cuttings are assumed to be discharged as a result of all OCS, activities in
                  offshore Subarea C-3.) Deposition of drilling muds and cuttings on the hard-bottom communities would not
                  significantly impact the biota of the hard-bottoms or the habitat itself. The biota of the seafloor surrounding
                  the hard-bottoms are adapted to life in turbid conditions, and existing currents in the regions would prevent
                  the adverse accumulation of large amounts of muds and cuttings. The depth of water would dilute the effluent
                  to a significant degree, and the hard-bottoms themselves are coated with a veneer of sediment Additional
                  deposition and turbidity caused by a nearby well are not expected to affect the hard-bottom environment
                  significantly, because since such fluids are discharged into very large volumes of water (the open Gulf of
                  Mexico) and rapidly disperse, can be measured above background at only very short distances from the
                  discharge point, and have little biological effect except very close to the discharge point Such an event would
                  rarely impact the resource because of the depth of the communities. The impact from muds and cuttings
                  discharged as a result of the proposed action would be such that any changes in the regional physical integrity,
                  species diversity, or biological productivity of the hard-bottom region would recover to pre-impact conditions
                  in less than two years, more probably on the order of 2-8 weeks.
                      Pipeline emplacement will resuspend sediments and may clog filter-feeding mechanisms and gills of fishes
                  and sedentary invertebrates. The stipulation, or some similar protective measure, will severely limit oil and gas
                  activities in the immediate vicinity of the hard-bottom communities. For the purposes of this analysis, it is
                  presumed that pipeline-laying activities would be prohibited in the proximity of live-bottom communities. The
                  effect of pipeline-laying activities on the biota of the hard-bottom communities would be restricted to the
                  resuspension of sediments. It is likely that pipelines up to 2,125 kin of pipelines are expected to be installed
                  under the Cumulative scenario in offshore Subarea C-3. Enforcement of the biological stipulations minimize
                  pipeline-laying activities through the hard-bottom region. The severity of these actions has been judged, at the
                  community level, to be such that any changes in the regional physical integrity, species diversity, or biological
                  productivity of the hard-bottom region would recover to pre-impact conditions in less than two years, more
                  probably on the order of 2-8 weeks.










                 IV-296

                     Off spills resulting from the OCS program and import tankering have been described earlier under Gulf
                 of Mexico Marine Mammals (Section IV.D.I.c.(3)(a)). That description includes assumptions of off-spill
                 occurrence, spill sizes, and estimated contacts with shoreline and wetlands areas.
                     Oil spills have the potential to be driven into the water column, with measurable amounis documented at
                 depths approximating 10 m. At this depth, the oil is only found at concentrations several orders of magnitude
                 lower than the amount shown to have an effect on marine organisms (Lange, 1985; McAuliffe et al., 1975 and
                 1981). In spite of the large number of surface spills, for the purpose of this analysis, it is projected that no
                 surface spills, regardless of size, would have an impact on the biota of the hard-bottoms, largely because these
                 features occur at depths greater than 10 in. No impact from surface oil spills on the communities is expected.
                     It is assumed that four pipeline spills greater than or equal to 1,000 bbl will occur in the northeastern Gulf
                 of Mexico. One of these pipeline spills is assumed to occur in the general vicinity of the hard-bottom region.
                 This subsurface spill would have to come into contact with a pinnacle feature or low-refief We bottom for an
                 impact to be observed. Few pipelines exist within these regions from which a spill would occur, and the
                 biological stipulations would prevent the construction of pipelines immediately adjacent to these features.
                     There have been only 31 oil spills from pipelines on the OCS, 23 of which were between 50 and 1,000 bbl
                 and only 8 were more than 1,000 bbl (USDOI, MMS, 1988c). Any spilled oil would have to impinge directly
                 upon the features to be detrimental to the communities; impacts, including uptake of hydrocarbons or reduced
                 visibility, may then be serious to the local biota, or even fatal. However, most of the region is washed in strong
                 currents, and exposure to such an event would be short-term (3-96 hours). The biota would survive and
                 recover once the features were clear of the oil.
                     There is a likelihood of the assumed pipeline spill contacting a hard-bottom community. However, for the
                 purpose of this analysis, it is assumed that a spill greater than or equal to 1,000 bbl (regardless of the source)
                 would contact one community. The above-listed factors would serve to limit the extent of damage from the
                 spill. The severity of the contact would be such that any changes in the regional physical integrity, species
                 diversity, or biological productivity of the pinnacle region would recover to pre-impact conditions in less than
                 two years, more probably on the order of 2-8 weeks. The widespread nature of the resource, the strong
                 dominant currents of the region, and the probable random occurrence of the pipeline spill will serve to limit
                 the effect of any pipeline spill on the hard-bottom communities.
                     Blowouts have the potential of resuspending sediments and releasing hydrocarbons into the water column,
                 which may affect benthic communities. Subsurface blowouts can pose a threat to the biota of these
                 communities if a blowoutwere to occur near one of these habitats. From 1956 to 1989, 157 blowouts occurred
                 on the OCS, only 28 of which resulted in the release of oil into the environment. Of these, 16 involved less
                 than I bbl of oil spilled; only 2 blowouts resulted in the spillage of more than 6,000 bbl (USDOI, MMS, 1988c).
                 It is assumed that 7 blowouts will occur for every 1,000 wells drilled, or approximately 30 blowouts across the
                 nortlicentral region as a result of the Cumulative scenario. Blowouts are not expected to be a significant threat
                 to these communities because of the protective distances imposed by the biological stipulations. The frequency
                 of subsurface blowouts impacting the resource is judged to be rare, and it is expected that any effects would
                 be small in area. The biological stipulations prevent the drilling of wells close to biologically lush communities,
                 thus preventing most adverse impacts from this factor. Blowouts outside this zone are expected not to have
                 an impact on the biota of the region because of the distances and strong currents. The severity of the contact
                 would be such that any changes in the regional physical integrity, species diversity, or biololocal productivity
                 of the pinnacle region would recover to pre-impact conditions in less than two years, more probably on the
                 order of 2-4 months.
                     The impact analysis presented above presumes implementation of a biological stipulation, or some
                 comparable mitigation, in the vicinity of the biologically productive hard-bottom communities. Should that
                 protection not be provided, adverse impacts resulting from the proposed action, particularly anchor damage
                 to localized hard-bottom areas, are expected to have adverse impacts on some individuals at portions of the
                 hard-bottom trend environment, because these activities have the potential to destroy some of the biological
                 communities and damage one or several individual hard-bottoms. The most potentially damaging of these are
                 the impacts associated with mechanical damages that may result from anchors. However, the action is judged
                 to be infrequent because of the limited operations in the vicinity of the hard-bottoms and the small size of
                 many of the features. Potential impacts from oil spills greater than or equal to 1,000 bbl, blowouts, pipeline










                                                                                                                              IV-297

                  emplacement, mud and cutting_ discharges, and structure removals exist. The proposed action, without the
                  benefit of the biological stipulation, is expected to have an adverse impact on the hard-bottom region.
                     In summary, non-OCS activities in the vicinity of the hard-bottom communities include recreational
                  boating and fishing, import tankering, and natural events (such as storm and hypoxic conditions). These may
                  lead to serious damage, and represent serious threats to the hard-bottom communities. Ships using the fairway
                  into Mobile, Alabama, can be expected to anchor in this area on occasion, and the numerous fishermen take
                  advantage of the relatively shallow and easily accessible resources of the region. These activities are expected
                  to lead to several instances of severe and permanent mechanical damage. It is projected that this damage to
                  one or more components of a few regionally common habitats or communities would result in changes to
                  physical integrity, species diversity, or biological productivity that exceeds natural variability observed prior to
                  the damage, and recovery to pre-impact conditions would take longer than 10 years.
                     Impact-producing factors resulting from routine activities of oil and gas operations include mechanical
                  damage caused by underwater oil spills, blowouts, anchoring, structure emplacement and removal, drilling
                  discharges, and pipeline emplacement. These activities may threaten the sessile and pelagic communities
                  associated with the crest and flanks of the hard-bottom and low-relief features of the hard-bottom region.
                  Because protection similar to that of the biological stipulations is assumed to be attached to leases issued as
                  a result of this proposal, the effects from these factors will have been mitigated on the biota of the banks. The
                  potential impacts from spilled oil include uptake of hydrocarbons and reduced visibility-, these impacts may be
                  serious or fatal to the local biota. A blowout within 100 in of a hard-bottom community could result in the
                  smothering of the biota within a very limited area of a hard-bottom due to sedimentation. The placement of
                  drilling rigs and platforms on the seafloor will crush the organisms directly beneath the legs or mat used to
                  support the structure, as will anchoring. Structure placement and anchor damage from support boats and ships,
                  floating drilling units, and pipeline-laying vessels disturb areas of the seafloor and are the most serious threat
                  to live-bottom areas at these depths. Structure removal using explosives (the most common removal method)
                  could suspend sediments throughout the water column to the surface and may cause substantial impacts to
                  nearby habitats. Deposition of these sediments would occur largely within the first 100 m of the site. Explosive
                  structure removals create shock waves, which could also harm resident biota in the immediate vicinity.
                  Smothering of organisms through deposition of drilling discharges (drill muds and cuttings) may occur; less
                  obvious sublethal effects may also take place. Pipeline emplacement directly affects the benthic communities
                  through burial and disruption of the benthos, and through resuspension of sediments. These resuspended
                  sediments may clog filter-feeding mechanisms and gills of fishes and sedentary invertebrates. The majority of
                  these impacts are mitigated through implementation of the biological stipulations or comparable measures.
                  Because protection similar to that of the biological stipulations will be attached to leases issued as a result of
                  this proposal, the effects from these factors will have been mitigated on the biota of the banks.

                  Conclusion

                      The impact under the Cumulative scenario on the pinnacle trend communities of the northern Gulf region
                  is expected to be such that this damage to one or more components of a few regionally common habitats or
                  communities results in changes to physical integrity, species diversity, or biological productivity that exceeds
                  natural variability (observed prior to the damage); recovery to pre-impact conditions is expected to take longer
                  than 10 years.

                  (b) Deep-water Benthic Communities

                      Cumulative factors considered to impact the deep-water benthic communities of the Central Gulf include
                  both oil- and gas-related and non-oil- and gas-related activities. The latter type of impacts includes activities
                  such as fishing, trawling, and anchoring. However, fishing and trawling in the deeper waters of the Central and
                  Western Gulf are minimal and impacts are minimal. Oil- and gas-related activities include pipeline and
                  platform emplacement activities and anchoring, instances of which are expected to be higher than under the










                 IV-298

                 Base Case (Section IVD.1.a.(2)(b)). This analysis considers the effects of these factors related to the proposed
                 action, and to prior and future OCS sales.
                     The greatest potential for adverse impacts to occur to the deep-water benthos stems from pipeline and
                 platform emplacement and associated anchoring activities. The impacts to benthos from these activities are
                 discussed above. As exploration and development continue on the Federal OCS, activities iri the Central and
                 Western Gulf regions have moved into the deeper water areas of the Gulf of Mexico. With this trend comes
                 the certainty that increased development will occur in these areas, accompanied by stress to the deep-water
                 benthos from bottom disturbances and disruption of the seafloor from associated activities. 'The extent of this
                 disturbance shall be determined by the intensity of development in these deep-water regions, as well as the
                 types of structures and mooring systems utilized. For instance, Table IV-7 indicates that in offshore Subareas
                 C-2, C-3, and C4 (where these communities would be found) an estimated 5,140 exploration and delineation
                 wells and 4,345 development wells will be drilled and 288 platforms and 4,525 krn (2,810 mi) of pipelines will
                 be installed. However, as noted in Section IV.D.1.a.(2)(b) above, NTL 88-11 operates to protect high-density
                 chemosynthetic communities in a high percentage of the cases (but not 100% of the time); for purposes of this
                 analysis, the frequency of impact from bottom disturbance is considered to be once every six months to two
                 years, but the severity of impact is such that the loss of elements and/or relationships will not occur.

                 Summary

                     The only impact-producing factor threatening the chemosynthetic communities is physical disturbance of
                 the bottom, which would destroy the organisms comprising these communities. Only structure emplacement
                 is considered to be a threat, and then only to the high-density (Bush HUI-type) communities; the widely
                 distributed low-density communities would not be at risk. The provisions of NTL 88-11 (currently in effect),
                 requiring surveys and avoidance prior to drilling, will reduce, but not completely eliminate, the risk.
                     Activities not related to the OCS oil and gas program include fishing, trawling, and anchoring. Because
                 of the water depths in these areas, these activities are not expected to have any impact on the chemosynthetic
                 communities.
                     The cumulative impacts are expected to be due entirely to the activities of the proposed action (as analyzed
                 in Section IVD.La.(2)(b)) because activities unrelated to the OCS oil and gas program, such as fishing,
                 trawling, and anchoring, are not expected to have any impact on these chemosynthetic communities.

                 Conclusion


                     The activities associated with the Cumulative scenario are expected to cause little damage to the physical
                 integrity, species diversity, or biological productivity of either the widespread, low-density chemosynthetic
                 communities or the rarer, widely scattered, high-density Bush Hill-type chemosynthetic communities. Recovery
                 from any damage is expected to take less than 2 years.

                 (c) Topographic Features

                     Oil and gas leasing has been increasing around the topographic features of the Central Gulf, and this trend
                 is expected to continue in the future. Of the 167 blocks in the CPA near the topographic features, 105 are
                 under active lease (Appendix A). Many oil and gas operations on the previously leased blocks are subject to
                 the provisions of a biological stipulation. For purposes of this analysis, the Topographic Features Stipulation
                 is included in the analysis below. For this reason, these operations are not expected to have an adverse impact
                 on the biota of the topographic features. Thus, the impact from cumulative oil and gas routine operations
                 would be limited to those from the operations conducted as a result of any future OCS sales held without
                 benefit of the proposed stipulation. The impacts, without benefit of the proposed stipulation, are expected to
                 be very destructive of the reefal communities of the banks (Section II.Al.c.(I). The impact from cumulative
                 oil and gas routine operations includes those from the operations conducted as a result of the proposed action
                 (as explained in Section IVD.La.(2)(c)). These operations include anchoring and structure emplacement,










                                                                                                                           IV-299

                effluent discharge, blowouts, oil spills, and structure removal, future OCS sales, past sales (which include the
                proposed biological stipulation of Section II.Al.c.(l) for analysis purposes), hurricanes, the activities of scuba
                divers, the collapse of the tops of the features due to dissolution of the underlying salt structure, ocean
                dumping, and the tankering of imported oil.
                   Anchor damage and damage from structure emplacement are considered to be the most serious threats
                to coral and coral-community areas (Bright and Rezak, 1978; Rezak and Bright, 1981). The biological
                stipulation on the existing leases and proposed for leases resulting from this proposed action prohibits the
                anchoring of industry-related vessels and the emplacement of structures by the industry in the No Activity
                Zones; the potential stipulation does not affect other activities such as anchoring, fishing, or recreational scuba
                diving. No data are available on the extent to which such anchoring may take place; however, all three
                activities are known to occur in proximity to the topographic features. Nearly all the banks are near established
                shipping fairways. The banks are apparently well-known fishing areas. Several of the shallower cresting banks
                are scuba trip destinations. Anchoring at a topographic feature by a vessel involved in any of these activities
                would cause significant damage to the biota, and although the degree of damage would depend on the size of
                the anchor and chain, there is the potential for serious anchor damage to the biota of the topographic features.
                   Treasure hunters have destroyed large areas of Bright Bank by using explosives to blast through the coral
                reef. The impact has been high to Bright Bank as a result of this blasting activity, however, such blasting is
                not a common event. All of the impacts described above for the Base Case would also pertain in this case.
                Thus, for the purpose of this analysis, the frequency of these events is judged to be once or twice each year,
                and the severity of the impact is considered to be such that there is no loss of elements and/or relationships;
                and such perturbations would last for periods from 6 months to 2 years at the regional scale and for periods
                of 2-5 years at the local scale. Recovery of the system to pre-interference conditions is probable.
                    The routine discharge of drilling muds and cuttings will greatly increase under this scenario. As noted
                above under the Base Case, most water-based fluids are relatively nontoxic (the more toxic effluents are not
                allowed to be discharged under the NPDES permit), and their effects are limited to the immediate vicinity of
                the discharge (NRC, 1983). No effects to the biota of the topographic features are expected due to toxicity.
                Small amounts of drilling effluent may reach a bank from wells drilled more than 1,000 m away, however, these
                amounts from single wells, where measurable, would be extremely small and would have no effect on the biota.
                Effluents discharged at the water's surface within 1,000 m of a bank could impact the biota of the bank,
                although the currents at the banks would tend to keep the bank swept clean of fine sediments and would
                prevent the accumulation of drilling muds at the bank. The muds and cuttings can smother the sessile benthic
                invertebrates; turbidity from the discharge can reduce light levels to benthic organisms and clog the feeding
                mechanisms of sessile invertebrates. These conditions can lead to reduced productivity, susceptibility to
                infection, and mortality. The MMS, as a condition of the operational plan approval, can require the operator
                of a lease to perform certain measures, such as shunting, that would reduce the impacts to the biota of the
                banks to very low. The USEPA, through its NPDES permitting procedures, may also require mitigative
                measures. Current leases and leases resulting from this proposed action near topographic features may contain,
                at the option of the Secretary, a biological stipulation that protects the biota of the bank from most impacts
                from oil and gas operations, but leases resulting from future lease sales may not contain this restriction. For
                purposes of this analysis, it is assumed that such impacts will occur once each year and that the severity of the
                impacts is judged to be such that there is no loss of elements and/or relationships. Such perturbations would
                last for short periods at both the regional and local scales. Recovery of the system to pre-interference
                conditions would be rapid.
                    There is an estimated 99+ percent chance of an oil spill greater than or equal to 1,000 bbl occurring in
                the Central Gulf as a result of the OCS Program (Table IV-19). It is also assumed that 830 spills of greater
                than I and less than 50 bbl will occur each year and that 33 spills of greater than 50 and less than 1,000 bbl
                will occur during the 35-year life of the proposed action (Section IV.C.3.a.). It is assumed that 7 oil spills of
                1,000 bbl or greater will occur on the OCS from OCS oil and gas operations, with an additional 37 spills
                resulting from import tankering (Section IV.C.1). Because of the water depths in which topographic features
                are found, no oil will reach the biota of concern. As discussed for the Base Case, blowouts seldom occur in
                the Gulf and, even if one occurred, it is expected that any oil spilled into the water column from a blowout










                 IV-300

                 would not reach the biota of a topographic feature. Therefore, it is assumed that no spills of any size would
                 contact the biota of the topographic features.
                      Many platforms could be removed during the life of this proposed action; some may be near topographic
                 features. However, the proposed Topographic Features Stipulation (Section II.A.1.c.(1)),, which has been
                 applied in the past to all leases on or near such features and which may be applied to leases resulting from
                 this proposed action, prevents the installation of platforms in the near vicinity of the biota of concern, thus
                 reducing the potential for impact from this factor. Therefore, the impact from this factor is negligible. See
                 Section IV.A.2.a.(3) for more information regarding structure removals.
                      Impacts to the topographic features could occur as a result of operational discharges from import and
                 shuttle tankers. Due to the dilution factor and the depths of the banks, this activity is expected to have a very
                 low level of impact on the topographic features. This is also true for the very low level of oa-lan dumping that
                 occurs in the Gulf (and which is being phased out).
                      Impacts from natural occurrences such as hurricanes are not expected to result in damage to the biota of
                 the banks. Collapse of the crest of the banks from dissolution of the underlying salt structure is possible, but
                 unlikely and certainly uncontrollable by human activity.
                      Scuba divers may visit the shallow banks, and their collecting activities may have an adve:rse impact on the
                 biota of those banks. Other than anchor damage, however, such activities are not expected to have major
                 impacts on the banks.
                      The other impacts to the biota of the topographic feature described above for the Base Case would also
                 obtain here, but at a greatly increased level.

                 Summary

                      Those activities causing physical disturbance to the bottom of the topographic features and presenting the
                 greatest threat to the biotic communities of the banks would be prevented by the imposition of the proposed
                 Topographic Features Stipulation. Those OCS oil and gas program-related activities include anchoring of
                 vessels and structure emplacement, operational discharges (drilling muds and cuttings, p:roduced waters),
                 blowouts, off spills, and structure removal.
                      Non-OCS oil and gas activities are judged to have little, if any, impact on the biota ofthe topographic
                 features (except for anchoring, described in detail above). These activities include hufficanes,activities of scuba
                 divers, the collapse of the tops of the banks, ocean dumping, and the tankering of imported oil.
                      Activities resulting from this proposed action, especially bottom-disturbing activities, have a potential for
                 causing low impacts to the biota of the topographic features. While some of the activities are expected to
                 result in lower impacts, those having the greatest impacts are also those most likely to occur.
                      'Me cumulative impact to topographic features is expected to be low. The incremental contribution of the
                 proposed action (as analyzed in Section IV.D.La.(2)(c)) to the cumulative impact level is very low because of
                 the implementation of the Topographic Features Stipulation, which would limit operational discharges, and to
                 the low probability (and thus risks) of accidental OCS-related events such as blowouts and oil spills.

                 Conclusion

                      The activities assumed for the Cumulative scenario are expected to cause little to no damage to the
                 physical integrity, species diversity, or biological productivity of the habitats of the topographic features of the
                 Gulf of Mexico. Small areas of 5_10 M2 would be impacted, and recovery from this damage to pre-impact
                 conditions is expected to take less than 2 years, probably on the order of 24 weeks.










                                                                                                                              IV-301

                  (3) Impacts on Water Quality

                  Coastal and Estuarine Waters

                      The Cumulative Analysis considers the effects of low-level routine point and nonpoint source discharges,
                  such as industry effluents, both chronic low-level and large accidental hydrocarbon and chemical discharges,
                  and natural seepage entering the coastal or nearshore waters of the northern Gulf of Mexico. These discharges
                  occur from urban and agricultural expansion, municipal and industrial wastes, recreational and commercial
                  boating, maritime commerce, dredging activities, natural events, State oil and gas development activities, and
                  the proposed action plus other OCS off and gas development activities due to past and future sales. Section
                  IV.B. presents information on major activities occurring in the Gulf and its coastal areas.
                      The major causes of nonpoint source contamination in Louisiana are listed in the Section 319 State of
                  Louisiana Nonpoint Source Pollution Assessment Report (Louisiana Dept. of Environmental Quality, 1988).
                  The report identifies agriculture, general construction in the coastal zone, hydromodification,silviculture, septic
                  tank leakage, and urban runoff (Louisiana Dept of Environmental Quality, 1988). This report shows a
                  substantial percentage of the coastal area to be significantly affected by nonpoint source pollution so that
                  identified areas do not support fully designated uses of surrounding water. Given the expected continuous
                  nature of these discharges, but accounting for the filtering and assimilative capacity of wetlands (Kennedy,
                  1984) and the improved environmental regulatory programs adopted by the Gulf coastal States (such as tougher
                  water quality standards), chronic point and nonpoint source discharges are expected to cause localized and
                  short-term (up to several weeks) degradation of coastal waters throughout the Gulf region.
                      Section IV.B.6. presents an overview of the major sources of oil contamination in the Gulf. This overview
                  shows that these larger oil spill incidents and chronic small inputs impact water quality but are overshadowed
                  by the input of the Mississippi River. Clearly, the major source of oil contamination of Gulf waters is the
                  contaminated waters coming down the Mississippi River (78%), a conclusion supported by a number of major
                  studies conducted in the Gulf of Mexico, including the MAFLA study, the Buccaneer Oil Field Study (Bedinger,
                  1981), and the Southwest Research Institute Platform Study (Middleditch, 1981). The Mississippi River also
                  carries both nonpoint source runoff and point source discharges from industrial, municipal, and agricultural
                  industries along or near its levees. The plume contains high amounts of sediments and organic chemicals, trace
                  metals, and pesticides, which interact with the coastal and nearshore waters of Louisiana and Texas.
                  Hydrocarbons were the most significant of the pollutants found in the sediments of Mississippi Sound (Delfino
                  et al., 1984). Analyses revealed three principal sources of pollutant hydrocarbons: petroleum associated with
                  the Pascagoula refinery, fuel off, and sewage. Land runoff apparently contributed some of the contamination.
                      Vessel traffic associated with both State and international oil and gas industry activities is expected to be
                  extensive in the Louisiana coastal areas, especially within the Mississippi Delta area. Discharges from service
                  boats and barges, although diluted and discharged slowly over large lengths of channel, will be great enough
                  to result in some degradation of water quality in the navigation channels traversed. Besides impacts to water
                  quality from operational discharges of oil and gas industry vessel traffic, impacts will occur along the Gulfs
                  coastal waterways, the GIWW, and within bays and coastal rivers from discharges from other types of vessel
                  traffic. These include maritime commerce, private recreational boats, and commercial and recreational fishing
                  activities. The combined vessel traffic associated with these activities will be extensive and is expected to
                  impact nearshore and coastal waters within the entire coastal zone through bilge and ballast water discharges,
                  sanitary and domestic waste discharges, releases of antifouling paint compounds, and spills less than 1,000 bbl
                  and spills greater than or equal to 1,000 bbl events. Impacts from such sources are substantial enough to cause
                  low-level effects when discharged into confined waters over a long period. Impacts to open waters are expected
                  to be negligible, not causing changes in water quality characteristics.
                      The discharge of sewage and wastes from boats and vessels in coastal waters may impact water quality by
                  increasing BOD locally and introducing pathogens into the water column. The Federal Water Pollution Control
                  Act requires recreational boats to be equipped with approved marine sanitation devices; however, boats still
                  legally discharge treated and illegally discharged untreated waste into coastal water bodies. Although the
                  wastewater generated by recreational boats is small, the organics are concentrated and, therefore, the BOD










                 IV-302

                 levels are much higher than that of raw or treated municipal sewage. When this occurs J          .in poorly flushed
                 waters, the DO concentrations of the water may decrease. In more temperate regions, these effects are
                 exacerbated due to increased boat traffic, higher water temperatures, and higher metabolism rates for marine
                 organisms. The addition of disease-carrying pathogens from fecal matter in boat sewage poses a potential
                 problem with regard to human health impacts. Humans are put at risk from either contacting contaminated
                 waters through swimming or eating shellfish taken from such waters. Bacteria, viruses, and other water-borne
                 diseases can be attributed to sewage pollution.
                     Antifouling paints and coatings containing copper and organotin biocides are used to prevent the buildup
                 of barnacles and other encrusting organisms on vessels and docks. Other toxic compounds such as mercury,
                 arsenic, and PCBs are no longer used due to their extreme toxicity. By 1985, up to 30 peromt of the vessels
                 worldwide used tnbutyltin-containingantifouling paints. A 1987 survey found that 97 percent. of the tributyltin
                 use was on vessels or boats less than 65 ft, and that 93 percent of this was on recreational boats. Tributyltins
                 are a class of organic tins used in antifouling paints. There are two classes of these paints-conventional, or
                 those that leach continuously, and copolymer, which are released to the aquatic environment at much slower
                 rates. Due to the rapid leaching of these compounds, elevated levels of tributyltin and its breakdown products
                 have been found in the water, sediments and organisms where there are high concentrations of vessels and,
                 more specifically, recreational boats.
                     Studies indicate organotin is highly toxic at very low levels to marine and freshwater organi@sms. Tributyltins
                 have been reported to cause acute and chronic toxicity to marine organisms, especially in small crustaceans
                 (zooplankton) and bivalves. Bacteria and phytoplankton bioaccumulate tributyltin at concentrations of 600 to
                 30,000 times the exposure concentration, while bioaccumulation in bivalves has been reported up to 4,000 times
                 the exposure concentration. Bivalves are extremely susceptible because of their ability to metabolize these
                 compounds, which are found in nearly anoxic sediments that lack the bacterial species necessary to degrade
                 these compounds.
                     Unlike copper, tributyltin in seawater degrades rapidly, with a half-life of 3-15 days (seawater). Within the
                 water column, the primary means of degradation in the presence of light appears to be debutylation by
                 planktonic algae, especially diatoms. In the absence of light, degradation is primarily by bacteria. Tributyltins
                 tend to concentrate in the surface microlayer and are found at higher levels than found in the subsurface.
                 Once these compounds adsorb to particulate matter and sink into the sediments, they tend to, concentrate and
                 slowly degrade.
                     Tributyltin paints are now regulated in the United States by the Organotin Antifouling Paint Control Act
                 of 1988. The Act prohibits the use of certain antifouling paints containing organotin and the use of organotin
                 compounds, purchased at retail, to make paints. The Act prohibits the application of antifouling paints to
                 vessels less than 25 in in length, with the following exceptions: the aluminum hull of a vessel less 25 in in
                 length or the outboard motor or lower drive unit of a vessel less than 25 in in length. All antifouling paints
                 must be certified by the Administrator of USEPA not to have a release rate of more than 4.0 micrograms          per
                 square centimeter per day.
                     Dredging activities (Section IV.B.) associated with maintenance dredging and deepening of channels, and
                 the creation of ports, marinas, and private docks, will continue to impact the Gulf's coastal waters. A number
                 of maintenance dredging projects are ongoing, especially in the Mississippi River passes area, other navigation
                 channels, and along the GIWW. Dredging activities are expected to result in localized impacts (primarily
                 elevated water column turbidities) occurring over the duration of the activity (up to several months). Such
                 activities would preclude some recreational and commercial water uses within the immediate area of this
                 activity. The periods between expected dredging operations will generally allow for the recovery of affected
                 areas between such activities. Impacts are expected to be somewhat higher in the Mississippi Delta area
                 because of higher sediment inputs.
                     Continued offshore and onshore oil and gas activities will contribute to the cumulative impacts on coastal
                 and nearshore water quality. An unknown number of additional structures and facilities may be constructed
                 as a result of resource development in State waters and coastal areas. The construction and operation of
                 onshore facilities supporting domestic and international oil and gas activities may impact coastal and nearshore
                 water quality by routine point and nonpoint source pollution. Increased effluent discharges from support
                 facilities may contribute to point source pollution within coastal areas. These effluents are commonly










                                                                                                                               IV-303

                 discharged into surface waters after treatment. Surface runoff from existing refining and processing facilities
                 is extensive and can adversely impact the surrounding area. Runoff from these facilities is likely to contain off,
                 brine, particulate matter, heavy metals, petroleum products, process chemicals, and soluble inorganic and
                 organic compounds leached from the soft surface. Aside from adding contaminants to coastal waters, runoff
                 from such facilities may alter circulation in wetland areas and affect flushing rates and salinity gradients.
                 Because the majority of the facilities expected to support oil and gas refining and processing activities are
                 located primarily in coastal Texas and Louisiana, impacts of chronic discharges from these sources are expected
                 to be focused there.
                     Oil-field wastes generated from coastal and offshore oil and gas development activities and disposed of in
                 the Louisiana coastal area have contaminated groundwater and coastal water quality. As of November 1989,
                 the State of Louisiana's Department of Natural Resources (DNR), Conservation Division, has identified 13,000
                 oil-field pits that contain a variety of oil-field waste chemicals (McCarthy, personal comm., 1989). Interagency
                 projections estimate the total number of pits to be higher, closer to 20,000 dug in the last 10 years. Until
                 recently, these pits were unlined and resulted in degradation of usable groundwater through seepage of their
                 constituents (USEPA, 1988). The USEPA documented a number of cases of damage caused by these reserve
                 pits, both those illegal and those legal under Louisiana law. According to USEPA, these documented damages
                 suggest that all major types of oil-field waste and waste management practices have been associated to some
                 degree with endangerment of human health and damage to the environment. The principal types of wastes
                         ible for damage cases include general reserve pit wastes (drilling fluids and cuttings, pipe dope, rigwash,
                 responsi
                 diesel fuel, and crude off), fracturing fluids, production chemicals, waste crude oil, produced waters, and
                 miscellaneous wastes associated with oil-field exploration, developmentand production (USEPA, 1988). Until
                 March 1991, the State of Louisiana allowed for the direct discharge of waste drilling mud and produced water
                 into its bays and estuaries. There are documented cases of environmental damage to oyster beds and, thereby,
                 water quality from this practice (USEPA, 1988). The OCS off industry has contributed to this problem because
                 of its practice of coastal disposal of some produced waters (discussed below) and certain types of oil-field waste,
                 such as oil-based drilling fluids.
                     In the past, produced waters discharged from State oil and gas activities have been substantial and have
                 had adverse effects at many of the discharge sites. In 1986, 1,524,962 BPD of produced water were discharged
                 from 682 separation facilities associated with the Louisiana State oil and gas industry (Boesch and Rabalais,
                 1989a). In this report, it was estimated that another 823,575 bbl of produced waters from Texas State oil and
                 gas activities were discharged daffy into Texas State waters. In March 1991, the Louisiana State Legislature
                 approved regulations banning the discharge, into State waters, of all oil and gas activity-derived wastewaters
                 (primarily produced waters). The State's effluent guideline standards have been revised such that there shall
                 be no discharge of produced waters into State waters after January 1, 1995, unless the discharge(s) are
                 authorized in an approved elimination schedule or are in effluent limitation compliance. Given this legislation,
                 it is difficult to project the extent of impact, if any, of these future discharges. At sites continuing the practice
                 of coastal discharge, it is anticipated that elevated levels of salinity (50-150 ppt), dissolved and dispersed
                 petroleum hydrocarbons (10-50 ppm), organic acids, radionuclides, and trace metals may result around
                 discharge sites. Concentrations of the organic constituents will depend on the separation and treatment
                 technologies employed. Substantial hydrocarbon contamination of fine-grained sediments may extend out from
                 several hundred meters to over one kilometer from the point of discharge. Concentrations of aromatic
                 hydrocarbons in sediments may exceed background levels by over an order of magnitude.
                     It is assumed that 37 oil spills greater than or equal to 1,000 bbl will occur from import tankering in the
                 Gulf of Mexico during the life of the proposal. The average size of an import tanker spill is estimated at
                 30,000 bbl. Eight import spills (approximate size of 7,665 bbl) are assumed to occur in nearshore waters and
                 in port areas. Those port areas expected to receive the greatest number of these spills include the Louisiana
                 Offshore Oil Port (LOOP) and Mississippi River ports. Another 60 spills (average size of 10,000 bbl) are
                 estimated to occur in the CPXs coastal zone (primarily in coastal Louisiana) from coastwise movement of
                 petroleum products. Most of these spills are assumed to occur in the GIWW. Petroleum hydrocarbons
                 introduced into marine and coastal waters may have varied effects depending on the resource impacted, stage
                 of weathering, and local physical and meteorological conditions. Some crude oil components are highly toxic
                 and may cause damage to marine organisms due to the crude's aromatic content. It is expected that










                 IV-304

                 encountered, normal weathering processes will detoxify the off by breaking down its toxic components.
                 Background levels in the Gulf of Mexico were reported at /Ag/l. In shallow areas, oil may become entrained
                 in suspended particles and bottom sediments and subsequently be reintroduced into the waler column. The
                 assumption, based on these estimates and the frequent nature of spills over the fife of the proposal, is that the
                 effect of hydrocarbon contamination on the Gulfs coastal waters due to the proposed action is considered
                 negligible, with water characteristics rapidly returning to background levels within several days to weeks.
                     Within the Gulfs coastal zone, much of the existing infrastructure supporting offshore OCS oil and gas
                 activities is distributed throughout coastal Texas and Louisiana. About 90 percent of the eidsting capacity or
                 frequency usage of the oil industry infrastructure will support OCS operations in the future. The addition of
                 two new gas processing plants, up to three new pipeline landfalls, 48 kin of onshore pipelines, one new
                 terminal, and two new separation facilities is estimated to result from the cumulative OCS acthrities in the CPA.
                 All these activities are assumed to occur in coastal Subarea C-4. Both the use of new off and gas facilities once
                 constructed and the use of the existing facility network would contribute to the number of elffluents expected
                 to be discharged into coastal waters from petroleum activities primarily in the Louisiana coastal zone. The
                 construction and operation of onshore facilities supporting OCS activities may impact coastil and nearshore
                 water quality by routine point and nonpoint source pollution. Increased effluent discharges from support
                 facilities may contribute to point source pollution within coastal areas. These effluents are commonly
                 discharged into surface waters after treatment. Surface runoff from existing OCS facilities is extensive and can
                 adversely impact the surrounding area. Runoff from these facilities is likely to contain oil, brine, particulate
                 matter, heavy metals, petroleum products, process chemicals, and soluble inorganic and orgranic compounds
                 leached from the soil surface. Aside from adding contaminants to coastal waters, runoff from such facilities
                 may alter circulation in wetland areas and affect flushing rates and salinity gradients. Because the majority of
                 the facilities expected to support offshore oil and gas activities are located in Texas and Louisiana, impacts of
                 chronic discharges from these sources are expected to be focused there.
                     Vessel traffic associated with OCS oil and gas industry activities is expected to be exterLsive in the Texas
                 and Louisiana coastal areas, especially within the Mississippi Delta area. Approximately 701,200 service vessel
                 trips are estimated to support cumulative OCS activities in the CPA. Waterways along the Louisiana coast
                 where projected service vessel traffic will be the greatest include the Calcasieu River, Freshwater Bayou, the
                 Atchafalaya River, and within the Mississippi River passes. The other navigation channels will have significant
                 but lesser OCS vessel traffic. Import tankering and barge trips (6,828 barge vessel trips related to OCS
                 production activities) carrying both domestic and imported crude oil and products between terminals and
                 refineries along the Gulf Intracoastal Waterway (GIWW), adjoining navigation channels, and along coastal
                 nearshore fairways will add to this traffic. Shuttle tankering associated with OCS production in the CPA will
                 result in 575 trips, most of which will result from activities in the Eastern Gulf, offshore Florida.. While inshore,
                 service vessels are estimated to discharge approximately 3,000 liters of bilge water per trip in support of OCS-
                 related activities. An estimated four trillion liters (300 MM liters/day) will be discharged into coastal waters
                 of the CPA from vessels supporting OCS activities. Discharges from service boats and barges, although diluted
                 and discharged slowly over large lengths of channel, will be great enough to result in some water quality
                 degradation in the traversed navigation channels and GIWW. As noted in Alternative A, antifouling paints
                 used on boats and tankers have been shown to have toxic effects on some marine biota. Increased loadings
                 within coastal waters of tributyltin and copper compounds contained in antifouling paints are expected. Ballast
                 and bilge waters from shuttle tankers are assumed to be discharged at onshore reception facilities and are not
                 expected to impact coastal water quality. Operational discharges from shuttle tankering offshore are expected
                 to add to the overall hydrocarbon contamination of nearshore open waters. Tarballs formed from these service
                 vessel discharges will impact the Gulfs coastal beaches. Because no new service base locations are projected
                 for OCS activities, and none is likely for State activities, operational discharges associated with OCS service
                 vessel traffic will not impact coastal water quality. Impacts from such sources are substantial enough to cause
                 low-level effects when discharged into confined waters over a long time period. Impacts to open waters are
                 expected to be negligible.
                    No new navigation channels are expected to be dredged; however, maintenance dredging of major
                 navigation channels and deepening of some channels to support service vessel traffic are expccted. Dredging
                 activities are expected to result in localized impacts (primarily elevated water column turbidities) occurringover










                                                                                                                              IV-305

                the duration of the activities (up to several months). Such activities would preclude some recreational and
                commercial uses within the immed 'irate area. The periods for expected dredging operations win generally allow
                for the recovery of affected areas between such activities. Impacts from dredging are expected to be somewhat
                higher near the mouths of major rivers, where sediment inputs are greater. Approximately 48 kin of new
                pipelines are projected to be constructed in association with OCS activities; 98 percent of the oil and all of the
                gas produced will be transported ashore via the existing pipeline network. Pipelines reduce the need for barge
                and truck transport of petroleum and the potential for transfer spills. The environmental effects associated
                with chronic pipeline leakage and malfunction are generally considered small (USDOC, NOAA, 1985). Given
                this and the small percentage use of the existing pipeline network in support of the proposed action, impacts
                from leakage and hydrologic alterations associated with pipelines are considered negligible.
                     Onshore produced-water discharges originating from OCS oil and gas activities could have detrimental
                effects at the discharge sites. In MMS funded studies completed by LUMCON (Boesch and Rabalais, 1989a
                and b; and Rabalais et al., 1991), elevated concentrations of polynuclear hydrocarbons were found in sediments
                within a kilometer of the discharge sites. Total amounts of OCS produced waters expected to be piped ashore
                for separation, treatment, and disposal are 2.4 Bbbl. Because of the recent Louisiana Legislation concerning
                produced-water discharges, most of these waters will be piped ashore for separation and treatment then
                reinjection onshore, or be piped offshore and discharged into marine waters. Most of the 11 sites produced-
                water discharged sites discussed in the Boesch and Rabal" study are either discontinuing their operations or
                modff*g their sites for reinjection or transmission of these waters back offshore. At sites continuing the
                practice of coastal discharge up to January 1, 1995, it is anticipated that elevated levels of salinity (50-150 ppt),
                dissolved and dispersed petroleum hydrocarbons (10-50 ppm), organic acids, radionuclides, and trace metals
                may result around discharge sites. Concentrations of the organic constituents will depend on the separation
                and treatment technologies employed. Substantial hydrocarbon contamination of fine-grained sediments may
                extend out from several hundred meters to over one kilometer from the point of discharge. Concentrations
                of aromatic hydrocarbons in sediments may exceed background levels by over an order of magnitude.
                     It is assumed that 18 percent of the drilling muds (13.87 MMbbl) associated with sale-related drilling
                activities and 2.44 MMbbI of produced sand will be brought ashore for disposal. The improper storage and
                disposal of such oil-field wastes and contaminated oil-field equipment could result in adverse impacts to surface
                and ground waters in proximity to disposal facilities, cleaning sites, and scrap yards. Many of these wastes may
                be contaminated by NORM. Improper design and maintenance of such facilities could result in adverse
                impacts to these waters. The quantities of many wastes attributable to OCS activities, and more specifically
                the proposed action, are largely unknown, as are the associated environmental consequences and health risks.
                     Under the Cumulative scenario, 7 oil spills greater than or equal to 1,000 bbl would occur in the north-
                central Gulf offshore LA)uisiana-Mississippi-Alabama. Four of these oil spills would occur from pipeline
                sources, whereas 3 could originate from platform sources. The average size of these spills is 6,500 bbl. It is
                assumed that as much as 75 percent of the original volume of oil from the spill source will be lost as a result
                of weathering processes by the time the slick contacts the coast. It should be noted that there could be some
                effects from residual weathered oil that could reach coastal waters following a spill event, primarily in the form
                of tar material. Impacts from low-level contamination were discussed earlier. It is further assumed that 33 oil
                spills greater than 50 and less than 1,000 bbl and 830 oil spills greater than 1 and less than or equal to 50 bbl
                could occur from OCS pipeline, platform, and transportation sources within the CPA. Of these, it is assumed
                that few would contact coastal and estuarine waters. An additional 399 oil spills (less than 50 bbl--average size
                of 34 bbl) are assumed to occur in the CPA from spills related to the use of diesel and other potential
                pollutants. The effects of oil spills on coastal and marine waters were discussed previously under import spills.
                     Petroleum product spills are of great concern because the refined products of crude oil are often more
                toxic than crude itself. In general, refined oils is considered more toxic than crude due to the higher
                concentration of aromatic hydrocarbons and their greater ability to dissolve and disperse into the water column
                as a result of their less viscous nature. Refined oil, such as gasoline and kerosene, is likely to cause biological
                damage due to its toxicity over a relatively short period of time. Up to 60 petroleum product spills (average
                size 10,000 bbl) and another 670 smaller spills (most are less than I bbl) will occur in the CPA. Of these, most
                will occur in Louisiana port areas, along the GIWW, and near the Gulf coastline.










                 IV-306

                 Summary

                      Routine point and nonpoint source discharges from non-OCS activities, such as agriculture, general
                 construction projects, hydromodification, silviculture, septic tank leakage, urban runoff, and especially oil and
                 gas activities will degrade coastal and estuarine waters within the Gulf of Mexico's coastal zone. In addition,
                 maritime activities are expected to contribute to the degradation of waters near ports and major navigation
                 channels. Total hydrocarbon concentrations measured in Gulf of Mexico oyster and sediment samples from
                 the NOAA Status and Trends Program were generally lower than hydrocarbon concentrations at east and west
                 U.S. coast locations, probably because the sites in the Gulf are farther removed from point sources. The
                 following conclusions about hydrocarbon contamination can be made from the study- (a) chronic petroleum
                 contamination is taking place, possibly from oil and gas operations along the Gulf of Mexico (:oastline, but also
                 due to contamination of the discharge from the Mississippi River; and (b) water quality degradation is not
                 taking place to such an extent to show marked increases over U.S. coastal areas that do not have as many oil
                 operations.
                     All existing onshore infrastructure and associated coastal activities occurring in support of the proposed
                 action will contribute to the degradation of regional coastal and nearshore water quality to a minor extent
                 because each provides a low measure of continuous contamination and because discharge locations are
                 widespread throughout the Gulf Region. The effect of chronic contamination on the Gulfs coastal waters due
                 to the proposed action is considered negligible, with water characteristics rapidly returning to background levels.
                 The OCS-related vessel traffic is likely to impact water quality through routine releases of bilge and ballast
                 waters, chronic fuel and tank spills, trash, and low-level releases of the contaminants in antifouling paints.
                 Depending on the length of the affected channel, flushing rates, etc., it is expected that there will be some
                 localized short-term change (up to several weeks) in water quality characteristics from background levels. The
                 OCS produced-water discharges will have localized impacts at those sites that continue their coastal discharge
                 practice up to January 1, 1995. The Mississippi River Delta area will receive the greatest amount of these
                 discharges. It is anticipated that elevated levels of salinity (50-150 ppt), dissolved and dispersed petroleum
                 hydrocarbons (10-50 ppm), organic acids, radionuclides, and trace metals may result around. produced-water
                 dischargesites. Substantial hydrocarbon contamination of fine-grained sediments may extend out from several
                 hundred meters to over one kilometer from the point of discharge. The improper storage and disposal of oil-
                 field wastes and contaminated oil-field equipment would adversely impact surface and ground waters in
                 proximity to disposal facilities, cleaning sites, and scrap yards. Surface and groundwater in proximity to
                 improperly designed and maintained disposal sites and facilities could be adversely impacted with elevated
                 concentrations of arsenic, chromium, zinc, cadmium, mercury, lead, barium, penta-chlorophenol, naphthalene,
                 benzene, toluene, and radium.
                    Accidental spills will introduce oil into nearshore waters, creating elevated hydrocarbon levels (up to 100+
                 gg/1) within affected waters. Much of the oil would be dispersed throughout the water column over several
                 days to weeks. In shallow areas, oil may become entrained in suspended particles and bottorn sediments.
                 Water uses would be affected for up to several weeks from proposed spills and then only near the source of
                 slick. Other spills will occur from import tankering, transporting oil products throughout the Gulf, barging
                 crude off, etc. Refined oils are considered more toxic than crude due to the higher concentration of aromatic
                 hydrocarbons and their greater ability to dissolve and disperse into the water column as a result of their less
                 viscous nature. Products such as gasoline and kerosene are likely to cause biological damage due to their
                 toxicity over a relatively short period of time.

                 Marine Waters

                    This Cumulative Analysis considers the effects of impact-producing factors related to the proposed action,
                 plus those related to tankering and other vessel traffic, the Strategic Petroleum Reserve Program (SPRP), and
                 industrialwaste disposal activities that may occur and adversely affect the offshore water qualive in the northern
                 Gulf of Mexico. Specific types of impact-producing factors considered in the analysis include well-drilling
                 discharges, pipeline emplacement, hydrocarbon production formation waters, dredging, accidental oil spillage,
                 routine operational discharges, ocean disposal of hazardous material, and industrial waste dk;charges.










                                                                                                                             IV-3(Y7

                     Vessels vary in size and design as much as in function, ranging from small recreational craft used primarily
                 in coastal waters to defense-related naval vessels and ships of the merchant marine fleet up to several hundred
                 thousand tons in size. With respect to ships that maintain sizable crews, the pollutants are the large amounts
                 of domestic waste products such as sewage, food waste, and trash from the human activities on board. For
                 recreational vessels, sewage disposal from marine sanitation devices in highly populated, confined harbors and
                 anchorages is the primary pollution concern. Other problems are related to the movement of crude oil and
                 concern offshore unloading terminals (deep-water ports) and the identification of systems most reliable for
                 transfer of off from OCS production areas to shoreside facilities. Perhaps the most publicized source of
                 pollution is the operational discharge of oil by tankers in the merchant marine fleet. In 1979 alone, an
                 estimated 2.5 million gallons of petroleum hydrocarbons were discharged from ships operating within the Gulf
                 under normal operating conditions (USDC, NOAA, 1985). Regulations, coupled with the increased value of
                 oil, have led to development of new and better techniques, such as segregated ballast, crude-oil washing
                 systems, and oil-water separation systems for minimizing contamination of ballast water. Nevertheless,
                 enforcement of regulations and standards is still a problem.
                     Between 1946 and 1970 the Atomic Energy Commission (AEC) licensed the dumping of more than 86,000
                 containers of low-level radioactive wastes at 28 recorded dumpsites in the Atlantic and Pacific Oceans and the
                 Gulf of Mexico. Of these, only 2 dumps were made in the Gulf of Mexico (USEPA, 1980). Ocean dumping
                 was discontinued in June 1970 following a policy recommendation by the President's Council on Environmental
                 Quality (CEQ) in its 1970 report to the President. The United States has never disposed of its high-level
                 wastes in the oceans, and in 1972 two major legislative initiatives were enacted prohibiting future disposal of
                 high-level wastes into coastal waters and rivers. The Ocean Dumping Act, in addition to regulating ocean
                 disposal of low-level waste, prohibits the dumping of high-level waste and radiological warfare agents in ocean
                 waters. Soon after the Ocean Dumping Act was enacted, the Clean Water Act was amended to extend the
                 prohibition to all navigable waters.
                     The development and operation of salt-dome storage cavities associated with the Strategic Petroleum
                 Reserve Program, which is mandated by the Energy Policy and Conservation Act of 1975 (42 U.S.C. ï¿½6201 et
                 seq.), results in a concentrated brine solution that must be disposed of. The brines are normally discharged
                 into the Gulf of Mexico through diffusers to promote rapid dilution to background salt concentrations.
                 However, the brines are denser than seawater and tend to flow along the seafloor, affecting bottom-dwelling -
                 organisms until sufficient dilution has been achieved. In addition, hydrocarbons and other harmful constituents
                 may be dissolved in or entrained with the brine discharge. Brine discharges are regulated by USEPA under
                 NPDES.
                     Offshore sulphur operations off Louisiana have been ongoing since 1954. As with oil and gas activities,
                 potential wastewater degradation resulting from sulphur mining operations will be governed by numerous
                 factors. Bleedwater is by far the largest quantity of waste discharged during normal operations. Bleedwater
                 is typically discharged directly into surface waters, and the dissolved solids in these streams closely approximate
                 those of seawater. Sulfide in bleedwater will have a brief presence once discharged. Data from years of testing
                 by Freeport McMoran at its Grand Isle Mine indicate that bleedwater is not measurable at 300+ feet from
                 the source. Accidental spills of molten sulphur would have a minimal impact on nearshore or offshore water
                 quality. Impacts to water quality within the Gulf are expected to be negligible.
                     Spills from import tankefing (average spill. size 30,000 bbl) and Guffwide OCS activities may affect offshore
                 water quality as indicated (see previous discussion under Coastal and Estuarine Waters). It is assumed that
                 37 oil spills greater than or equal to 1,000 bbI will occur from import tankering in the Gulf of Mexico during
                 the life of the proposal.
                     As indicated in the Base Case Analysis, immediate effects would be brought about by increased drilling,
                 construction, and pipelaying activities, causing an increase in water column turbidities to the affected offshore
                 waters. Pipeline construction activities may result in the resuspension of some 8.4 million yd3 of sediment.
                 Offshore Subarea C-2 will support the greatest portion of program-related pipeline burial activities and
                 associated sediment resuspension, with 2.5 million yd3. Pipeline construction activities may result in the
                 resuspension of settled pollutants, toxic heavy metals, and pesticides, if present. Impacts resulting from
                 resuspension of bottom sediments following an explosive structure removal include increased water turbidity
                 and mobilization of sediments containing hydrocarbon extraction waste (drill mud, cuttings, etc.) in the water










                IV-308

                column. The discharge of 102 MMM3 of NPDES-regulated, treated sanitary and domestic wastes from the
                various rigs and platforms will increase levels of suspended solids, nutrients, chlorine and BOID near the point
                of discharge. These are considered minor discharges and are quickly diluted. Treated deck drainage and
                domestic wastes are most often taken ashore for proper disposal at an approved site. Up to 12.3 Bbbl of
                produced waters are estimated to result from cumulative OCS activities in the CPA. Of this, 2.4 Bbbl will be
                transported onshore for separation, treatment, and disposal. Offshore Subareas C-2 and C-3. will receive the
                greatest number of these discharges with 3.67 Bbbl and 4.44 Bbbl, respectively. From the findings of
                investigators, MMS anticipates the effects of these discharges on offshore water quality to be limited to an area
                in proximity to the discharge source.
                     Some 76.6 MMbbl of drilling muds and 18.25 million yd3 of drill cuttings are estimated to result from
                drilling activities associated with the cumulative OCS activities in the CPA. As indicated in the Base Case
                Analysis, it is assumed that 18 percent of all muds used (13.8 MMbbl) will be brought ashore for disposal
                Drilling muds and cuttings are routinely discharged into offshore waters and are regulated byNPDES permits.
                As with produced-water discharges, offshore Subareas C-2 and C-3 would receive the greatest percentage of
                these potential discharges. An estimated 32.65 MMbbl of drilling muds and 4.4 million yd3,c)f Cuttings could
                be potentially discharged in offshore Subarea C-2, whereas in offshore Subarea C-3 an estimated 26.14 MMbbl
                drilling muds and 6.21 million yd3 of cuttings could be discharged. When discharged into the surrounding
                offshore waters, drilling muds may create turbidity plumes several hundred meters in length. Studies indicate
                that these impacts are restricted to an area within 300 to 500 m of the discharge site. Dilution is extremely
                rapid in offshore waters. A 1983 NRC study suggests that, for routine off and gas discharges, the various
                components measured, including turbidity, are at background levels by a distance of 1,000-2,000 m. As in the
                Alternative A analysis, the natural processes of dispersion, degradation, and sedimentation will result in
                immeasurably low concentrations of these materials within a few meters to a few kilometers of the discharge
                site.
                     It has been recognized that spills of hazardous materials may, in many cases, pose a more serious threat
                to marine ecosystems than oil spills. Substantial amounts of oil and hazardous materials enter the marine
                environment as a result of accidental spills. Alternative I analyzes the severity of oil spills to water quality in
                general. Program-related spills are discussed in the previous section under Coastal and Estuarine Waters. It
                is assumed that 60 petroleum product spills (10,000 bbl in size) will occur in the CPA from OCS-related
                activities. As previously noted, refined oils are considered more toxic than crude duel to the higher
                concentration of aromatic hydrocarbons and their greater ability to dissolve and disperse into the water column
                as a result of their less viscous nature. Products such as gasoline and kerosene are likely to cause biological
                damage due to their toxicity over a relatively short period of time. Although the focus in the past has been
                on the cleanup and mitigation of spilled oil, national attention has been shifting toward hazardous materials
                as the cause for most immediate concern. Much has been learned in the past 10 years about how to respond
                to oil spills; far less is known for spills of hazardous material. Unlike oil, whose properties are fairly uniform,
                hazardous materials have a wide variety of physical and chemical forms, complicating and making the response
                necessary for their cleanup and disposal much more difficult. Methods for the cleanup and mitigation of
                hazardous materials are not well established.


                Summary

                     Those activities that would impact the Gulfs marine waters include marine transportation and OCS oil and
                gas activities. Vessels range from small recreational craft used primarily in coastal waters to defense-related
                naval vessels and ships of the merchant marine fleet up to several hundred thousand tons in size. Pollutants
                from vessel traffic include large amounts of domestic waste products such as sewage, food waste, and trash
                from the human activities on board. Other problems are related to the movement of crude oil and concern
                offshore unloading terminals (deep-water ports).
                     With regard to OCS activities, immediate effects would be broughtabout by increased drilling, construction,
                and pipelaying activities, causing an increase in water column turbidities (lasting for several weeks) to the
                affected offshore waters. The magnitude and extent of turbidity increases would depend on the hydrographic
                parameters of the area, nature and duration of the activity, and bottom-material size and composition.










                                                                                                                          IV-309

                Offshore Texas would receive the greatest portion of program-related pipeline burial activities, whereas
                offshore Louisiana would receive the largest amounts of program-related operational discharges. Because of
                the continuous nature of oil and gas activities in the northwestern and north-central Gulf of Mexico, the
                frequency of drilling mud and cutting and produced-water discharges is judged to occur nearly continuously
                throughout these areas. Proposed produced-water discharges will be rapidly diluted within the immediate
                vicinity of the discharge source. Significant increases in water concentrations of dissolved and particulate
                hydrocarbons and trace metals are not expected outside the initial mixing zone or the immediate vicinity of the
                discharge source. Higher concentrations of trace metals, salinity, temperature, organic compounds, and
                radionuclides, and lower dissolved oxygen may be present near the discharge source. Within the mixing zone
                of the discharge, long-term effects to water column processes, consisting of localized increases in particulate
                metal and soluble lower molecular weight hydrocarbon (e.g., benzene, toluene, and xylenes) concentrations,
                may be implicated. Trace metals and hydrocarbons associated with the discharge may be deposited within
                sediments near the discharge point The proposed discharge of drilling fluids and cuttings would encounter
                rapid dispersion in marine waters. Discharge plumes will be diluted to background levels within a period of
                several hours and/or within several hundred meters of the discharge source. The accumulation of toxic trace
                metals and hydrocarbons in exposed shelf waters, due to periodic releases of water-based generic rhuds and
                cuttings, is unlikely, and the long-term degradation of the water column from such discharges is not a major
                concern. No effects to water uses from routine activities and discharges are expected.
                    Program-related and nonrelated crude oil spills will introduce oil into offshore waters and create elevated
                hydrocarbon levels (up to 100+ lLgl) within affected waters. Much of the oil will be dispersed throughout the
                water column over several days to weeks. Little effect to water use is expected from these spills, and then only
                in an area near the source and slick. Other spills will occur from import tankering (including oil from the
                TransAlaskan Pipeline), transporting oil products throughout the Gulf, barging crude oil, etc. Refinedoilsare
                considered more toxic than crude due to the higher concentration of aromatic hydrocarbons and their greater
                ability to dissolve and disperse into the water column as a result of their less viscous nature. Products such as
                gasoline and kerosene are likely to cause biological damage due to their toxicity over a relatively short period
                of time.


                Conclusion


                    Cumulative demands resulting from the proposal are expected to result in significant changes to the
                ambient concentration of one or more water quality parameters, up to several hundred to 1,000 in from the
                source of activities and for a period lasting up to several weeks or months in duration. Chronic, low-level
                pollution related to the proposal will occur throughout the life of the proposed action. Overall cumulative
                impacts, which include the effects of non-OCS-related factors and OCS activities will significantly degrade water
                quality, primarily within the Gulf of Mexico's coastal zone in highly urbanized and industrialized coastal areas.
                Maritime activities are expected to contribute to water quality degradation near ports and major navigation
                channels. In restricted or poorly flushed coastal water bodies, localized increases in pollutant concentrations
                may be severe and persist for months or longer. Chronic low-level pollution will continue to persist in marine
                and coastal waters.


                (4) Impacts on Air Quality

                    The Cumulative Analysis considers the impacts from the following factors and/or activities: the proposed
                action, past and future OCS sales, power generation, industrial activities, and transport in the CPA.
                    The scenario discussed in Section IV.A. (Table IV-7) for the Cumulative Case establishes that 5,890
                exploration and delineation wells and 5,130 development wells would be drilled, and 340 platforms would be
                emplaced. The sale area has been subdivided into four offshore Subareas: C-1, C-2, C-3, and C-4 (Figure IV-
                1). This discussion analyzes the potential degrading effects of OCS-related activities on air quality in each
                subarea. Table IV-7 presents for the Cumulative scenario the numbers of exploration, delineation, and
                development wells; platforms installed; and service vessel trips for each subarea. The following table shows










                 IV-310

                 total emissions from wells, platform complexes, and vessels in the CPA for the Cumulative Case. Observe that
                 NO,, is the most emitted pollutant, while SO. is the least emitted. More important is that this information
                 shows that wells and vessels contribute mostly NO.; while platforms contribute mostly NO,,, CO, and VOC.
                 These emissions were calculated by adding the emissions of wells and platforms over time. Vessel emissions
                 were calculated using the total number of service-vessel trips presented in Table IV-7.

                                                        Total OCS Emissions in the CPA
                                      (tons over the 35-year life of the proposed action-Cumulative Case)


                                 Activi                        NO,             CO             SO            THC          TSP

                         Service Vessels                      362,270.0     42,440.3       5,723.7         18,435.0      5,017.1
                         LTO Helicopters                        3,690.8       2,981.0         567.8          154.3          19.7
                         Cruise Helicopters                   11,924.2      34,069.0       2,555.2         2,777.4         473.4
                         Blowouts without Fire                     0.0            0.0          0.0             41.3         0.0
                         Spills without Fire                       0.0            0.0          0.0         1,785.0          0.0
                         Barge Loading                             0.0            0.0          0.0         4,059.0          0.0
                         Tanker Loading                            0.0            0.0          0.0              0.0         0.0
                         Transit Loss                              0.0            0.0          0.0         7,739.5          0.0
                         Tanker Exhaust                           102.8          11.2         127.7             0.2        788.2
                         Tug Exhaust                          12,342.2        1,229.7         159.2          556.3          82.3
                         Exploratory Wells                    56,956.3      15,196.2       6,655.7         1,471.4       5,097.3
                         Development Wells                    36,730.8        9,798.3      4,309.2           430.5       1,476.0
                         Platforms                          1,572,684.4     20,486.1       2,751.1         80,635.2        521.0

                         Totals                             2,056,701.5     126,211.8      22,849.6      118,845.1      13,475.0

                     Total emissions for each subarea in the CPA during the Cumulative Case are presented below. Observe
                 that Subarea C-1, which is the closest to land, generates the greatest emissions of all pollutan ts, while Subarea
                 C-4, the farthest from land, generates the smallest amounts of emissions.

                                                        Total Emissions in CPA Subareas
                                        (tons over the 35-year life of the proposed action--Cumulative)

                                   Pollutant               C-1           C-2               C-3              C-4


                                   NQ,               888,425.2        589,374.4         533,520.6         45,381.2
                                    CO                54,519.2        36,167.6           32,740.1          2,784.9
                                   so.                 9,870.3           6,547.8          5,927.3            504.2
                                  THC                 51,088.8        33,838.8           30,632.0          2,605.6
                                   TSP                 5,820.7           3,861.4          3,495.5            297.3

                     The total pollutant emissions per year are not uniform. During the early years of the OCS program
                 activities, emissions would be large and would decrease over time as reserves and production decrease. After
                 a maximum, emissions would decrease rapidly as platforms, wells, and service vessel trips decrease to minimum.
                     The following table presents peak emissions of primary pollutants from OCS program activities in tons per
                 year. It is very important to note that well drilling activities and platform peak emissions are not necessarily
                 simultaneous; so, the combined maximum emissions are not a simple addition of the individual peak emissions.
                 However, it is assumed that peak emissions from service vessel and other OCS-related activities, and combined
                 well and platform peak emissions, occur simultaneously. In this analysis the aggregate peak emissions, which










                                                                                                                        IV-311

               are 1.5 to 8.7 times the average emissions, will be employed. Use of peak emissions results in conservative
               impact level estimates from the OCS program activities.

                                                   Mean and Peak Emissions in the CPA
                                      (tons over the 35-year life of the proposed action--Cumulative)

                   Pollutant         Wells        Platforms        Vessels         Others          Mean         Aggregate

                       NQ,,       6,087.60       76,704.75      11,152.29           0.00       58,762.90       91,527.19
                        Co        1,624.10        9,991.74       2,306.61           0.00        3,606.05       13,277.41
                       so.          712.40           134.18        260.96           0.00          652.85        1 998.46
                       THC          177.10       29,071.77         626.38          467.99       3,452.57       30,273.26
                       TSP          611.20           187.85        182.31           0.00          385.00          872.01

                   The mean emissions were computed by dividing the total emissions by the 35-year life of the proposed
               action. Peak emissions from platforms are obtained from their temporal distribution. Platforms and wells have
               the greatest peak emissions, while vessels and other activities have smaller emissions in general. This
               phenomenon is contrary to the emission rates, where wells have greater rates than platforms.
                   The effects of the pollutants considered in this analysis were described in the Base Case analysis and win
               not be repeated here. The reader may consult that section.
                   Because the meteorological conditions described in the Base Case will not change for this analysis, neither
               will they be repeated. The only changes that occur in the Cumulative Case are those related to infrastructures
               and resources. These changes are reflected in an increase of emissions for an analy-zed pollutants. A
               comparison of cumulative emissions per year with those of the Base Case shows that cumulative emissions
               would increase by four to five times.
                   To estimate the potential impact of offshore emissions on offshore and onshore air quality, a steady state
               box model (Lyons and Scott, 1990) was employed. The model is an expression of mass conservation and
               assumes that pollutants are vertically dispersed and sources uniformly distributed. For the purpose of these
               air quality analyses, an assumption of uniform distribution of average sources throughout the planning areas
               at this early stage is a reasonable approach. Predominance of unstable atmospheric conditions over the sea,
               as discussed in Section III.A-2., ensures that pollutants are dispersed homogeneously. The model was applied
               to NO,, emissions because these are the largest emissions. Because VOC emissions are not inert, the box
               model cannot be used to assess their impacts on air quality. Concentrations for other pollutants can be
               estimated by multiplying the NO,, concentrations by the ratio of the pollutant emissions over the NO,, emissions.
               Concentrations of primary pollutants other than NO,, would be smaller by more than 65 percent. Impacts
               from VOC and CO will be estimated by comparing the offshore and onshore emission rates.
                   The box model was applied to the following conditions: onshore and offshore winds with speeds ranging
               from 1 to 7 ms-1, a mean mixing height of 900 m, and a low mixing height of 300 m. During periods of winds
               blowing offshore, concentrations reaching onshore from offshore CPA emissions are low. Conditions of
               onshore winds indicate that concentrations reaching land from Subarea C-3 varied between 3.86 and 0.32 jLgm      -3
               for speeds from 1 to 7 ms-1 and a mixing height of 900 m; for a 300-m mixing height, concentrations varied
               from 11.57 to 1.65 pgm  -3 under the same wind speeds. For Subarea C-1 the concentrations varied from 4.76
               to 0.62 /Agm-3 with a 900-m mixing height across the entire wind speed range; concentrations varied from 14.28
               to 1.87 Agm-3 with a 300-m mixing height across the entire wind speed range.
                   Concentrations for pollutants other than VOC would be smaller, as indicated above. Impacts to air quality
               for NO,,, SO,,, and TSP are moderate because the concentrations arriving onshore are enough to cause some
               areas to become border cases. However, under low wind speeds and low mixing heights impacts could be high,
               according to results from the box model. The MMS regulations (30 CFR 250.44) do not establish annual
               significance levels for CO and VOC. For these pollutants, a comparison of emission rates will be used to assess
               impacts. Formulas to compute the emission rates in tons/yr for CO are 3,400-13213 and 33.3-D for VOC. In
               these formulas, D represents distance in statute miles from the shoreline to the source. The CO exempt
               emission level in Subarea C-1 is 7,072.8 tons/yr, which is greater than peak emissions from the whole CPA-










                 IV-312

                 The exemption emission level of THC in Subarea C-1 is 100 tons/yr, while platform emission level is estimated
                 as 204.0 tons/yr.
                     Transport of pollutants toward onshore areas has a frequency maximum of 61 percent during summer and
                 only 37 percent during winter. Thus, the box model results are very conservative estimates of concentrations
                 arriving onshore from the OCS. The modeling effort does not consider removal processes such as rain, which
                 in the CPA has a high frequency (Section III.A.2.) and would reduce impact levels to onshore air quality.
                 Further, it is very important to note that OCS activity emissions will decrease over the 35-year life of the
                 proposed action. Thus, these estimated emission peaks will reach land during one year onb'.
                     The MMS has also studied the impacts of offshore emissions using the OCD Model (USDOI, MMS,
                 1986a). Eight offshore areas off Grand Isle, Louisiana, containing from 19 to 85 production complexes and
                 19 to 195 point sources, were used in the study. Source distance from the coastline ranged from 5.6 to 45 km.
                 (3.5 to 28 mi). The study employed a 300-m mixing height, which coincides with the lower mixing height
                 employed in the box model. Because the last model run in the study represents an aggregatJon of all sources
                 and covers the entire distance range, this discussion emphasizes those results. The annual arithmetic mean
                 varied between 0.82 and 1.83,ugm-3, which is below the national standard of 100 Agm-@
                     All other inert pollutants would have lower concentrations. This modeling effort represents the combined
                 effect of 85 production complexes close to onshore areas. Therefore, it is reasonable to assume that mean
                 hourly concentrations derived from emissions associated with OCS program activities (0.17 Ali, -3)
                                                                                                                 ,-m and spread
                 over 193.4 billion square meters would have a moderate effect.
                     Off-spill effects on air quality are examined below. It is assumed that oil spills in the category greater than
                 I and less than or equal to 50 bbl, as well as greater than 50 and less than 1,000 bbl, would have low impacts
                 on air quality because their input of pollutants (it is assumed that 30% of the spill evaporates in three days)
                 would be very small. Information from OCS accidents indicates emissions of fewer than 100 tons/hour by the
                 second hour. For spills greater than or equal to 1,000 bbl, emissions are about 285 tons/hour or smaller. If
                 the dispersion of emissions is taken into account, effects on offshore air quality would be temporary.
                     Nearly 3 percent of OCS crude-off production is offloaded from surface vessels at ports. The unintentional
                 emissions from these offloading operations are estimated as 4,059 tons of THC over the 35-year life of the
                 proposed action. This represents about 3.4 percent of the total VOC emissions in the CRAL Safeguards to
                 ensure minimum emissions from the offloading and loading operations have been adopted by the State of
                 Louisiana (The Marine Vapor Recovery Act, 1989- LAC: 111.2108).
                     Suspended particulate matter is important because of its potential in degrading the visibility in national
                 wildlife refuges or recreational parks, designated as PSD Class I areas. The impact depends on emission rates
                 and particle size. Particle size used in this analysis represents the equivalent diameter, which is the diameter
                 of a sphere that will have the same settling velocity as the particle. Particle distribution in the atmosphere has
                 been characterized as being largely trimodal (Godish, 1991) with two peaks located at diameters smaller than
                 2 Am and a third peak with a dia 'meter larger than 2Am. Particles with diameters of 2 Am or larger settle very
                 close to the source (residence time of approximately 1/2 day, Lyons and Scott, 1990). For particles smaller than
                 214m, which do not settle fast, wind transport determines their impacts. Results from the box model indicate
                 that the largest concentration for TSP will be 0.14 Agm-3. which is less than the allowable annual increase level
                 of 5 Agm-@ Therefore, suspended matter would have little effect on the visibility of PSD Class I areas.
                     Ozone is of great concern because of its environmental considerations. In the CPA six parishes have
                 nonattainment status for this pollutant (Section III.A.3.). Ozone measurements between 19,89 (La. Dept. of
                 Environmental Quality, 1989) and 1990 were examined from Morgan City in St. Martin Parish, Thibodaux in
                 Lafourche Parish, and Westlake in Calcasieu Parish. These measurements show that in Morgan City and
                 Thibodaux the ozone concentration never exceeded the national standard. Concentrations Nvere between 15
                 and 25 Agm-3. below the national standard during episodes of highest ozone concentrations. At other times
                 concentrations were 45 to 50 units below the national standard. At Westlake in Calcasieu Parish, which is
                 north of Cameron Parish, the ozone concentrations exceeded the national standards at least vvice during 1989
                 and once during the first eight months of 1990. Since Cameron Parish, a coastal parish, is attainment for all
                 pollutants, an argument could be made that OCS emissions are not the cause of Calcasieu Parish ozone
                 problems. Another area with ozone problems is Baton Rouge. Recent air modeling there (Haney et al., 1990)
                 indicates that ozone concentrations peak near 1600-1700 hours. The modeling effort, which included










                                                                                                                           IV-313

                anthropogenic and biogenic: sources, showed that some events could result from atmospheric overturning.
                During overturning episodes ozone from previous days is mixed downward and, coupled with local and
                imported input of ozone, causes the concentrations to exceed the national standards.
                     A recent report from the Lake Charles Ozone Task Force shows that out of 12 ozone exceedances in
                Calcasieu Parish, 3 cases show significant ozone contri"butions by transport from Texas. Another 3 cases with
                demonstrable transport ozone input occur, but the source areas are to the south or northwest. The report cites
                the Lake Charles industrial area to the south and the Beaumont and Orange, Texas, areas as the possible
                source areas in these cases. There were 5 other cases that showed local sources as the cause for the ozone
                exceedance episode. One episode cannot be studied with the methods employed by the Task Force for this
                analysis. Thus, there are 3 out of 12 cases where the ozone transport is correlated with southerly winds and
                that can point to some inputs from OCS offshore sources. However, the report never indicates this as a
                possibility or even speculates about the OCS role. Ozone measurements made between 1989 and 1990 in
                Alabama show only one ozone exceedance episode near the Chickasaw station. Another station located on
                Highway 43 shows no episodes of ozone exceedance over the same period. Both stations showed that ozone
                is seasonal with a maximum during August and a decrease during the fall and winter, when ozone levels are
                about 50 percent below the national standard of 235 LgM-3.
                     The amount of power generation is very difficult to predict because it depends on many nonquantiflable
                factors. Therefore, different sets of assumptions result in different estimates. The envelope of predictions
                shows that energy consumption should increase up to the year 2010; after this, predictions show more variation
                but generally indicate an increase of energy consumption. Because energy production is the largest single
                pollutant generator, it is safe to assume that emissions must also increase (USDOE, 1990). However, advances
                in control technology and use of alternative energy sources can change the correlation between energy
                production and emissions. The available information (USDOE, 1990) indicates that SO,, emissions from energy
                generation decreased 16.4 percent between 1970 and 1987. Other pollutants that showed a decrease over the
                1970-1987 period are particulate matter and NO, Although CO and VOC increased over the same period,
                the overall amount of emitted pollutants decreased.
                     Emissions of the primary pollutants related to industrial activities decreased over the 1970-1987 period.
                The reduction in the total amount of pollutants was 51 percent (Godish, 1991). The projected increase in
                employment (Section III.C.2.) can be interpreted as an increase of industrial activities. However, if the
                decreasing trend of emissions holds during the next 35 years, it is safe to assume that industrial emissions would
                not increase; at worst they would remain at present levels.
                     Transportation-related emissions are an important consideration in regard to inshore air quality, because
                vehicles constitute the second largest emitters Of S02 and NO,, and the largest source of carbon monoxide
                (USDOE, 1990). Emissions of particulate matter and SO. increased, while NO. emissions remained the same
                over the 1970-1987 period. Emissions of CO and hydrocarbons decreased over the same period. The overall
                emissions showed a reduction of almost 44 percent during the 1970-1987 period (Godish, 1991). Vehicular use
                is population-dependent, and the demographic trends through most of the 1980's have shown a population
                decrease in most Gulf Coast States. A recent projection for MMS (Section III.C.2.) indicates that this trend
                will be reversed, and population will increase. Thus, vehicular use will increase, but as the consequences of
                advances in fuel efficiency, alternative gasoline developments, and better emission controls, emissions will
                probably decrease or, at worse, remain at the same level.
                     Blowouts are accidents related to OCS activities and are defined as an uncontrolled flow of fluids from a
                wellhead or wellbore. In the Gulf of Mexico OCS there have been 157 blowouts over a period of 33 years
                (1956-1989) (Section IV.A.4.b.(4)). This represents an average of about 5 blowouts per year, but the number
                of wells drilled is a better indicator. The estimated number of blowouts at a rate of 7 blowouts per 1,000 wells
                drilled, is 130 blowouts during the Cumulative scenario in the CPA. The air pollutant emissions from blowouts
                depend on the amount of oil and gas released, the duration of the accident, and the occurrence or not of fire
                during the blowout.
                     Because of technological advances the duration of blowouts has decreased, and about 61 percent of the
                recent blowouts last 1 day or less, 19 percent last between 2 and 3 days, 7 percent last between 4 and 7 days,
                and 13 percent last more than 7 days (Fleury, 1983). Further, most blowouts occurred without fire (MMS
                Database). The amount of oil released during these accidents has been small. The total emission of THC is










                 IV-314

                 2,796 tons during the Cumulative scenario. It must be remembered that these are conservative estimates and
                 that the total amount of THC may be less; the VOC will also be less because it is a fraction of the THC.
                     Even though oil production in State waters is known to be taking place, the State of Louisiana cannot
                 provide information regarding the actual number of production facilities in State water; thus, it is impossible
                 to estimate their emissions.


                 Summary

                     The scenario discussed in Section W.A. (Table IV-12) for the Cumulative Case establishes that 5,890
                 exploration and delineation wells and 5,130 development wells would be drilled and that 340 platforms would
                 be emplaced. This is in addition to the 1,106 platforms that were considered as sources in this analysis. These
                 latter sources exist as a result of past sales. It is also assumed that power generation, transportation, and
                 industry will cause enough emissions to keep the present impacts at their actual levels. Maintenance of the
                 present impacts is due to the continuation of actual trends in energy consumption or technological
                 developments in fuel and motor efficiency.
                     The incremental contributionof the proposed action (as analyzed in Section IV.D.La.(4)) to the cumulative
                 impacts is low because of the prevailing atmospheric conditions and mixing heights affecting the transport and
                 dispersion of emissions, and the concentrations of pollutants reaching the onshore areas.

                 Conclusion


                     Emissions of pollutants into the atmosphere from the activities assumed for the OCS program are expected
                 to have concentrations that may not change onshore air quality classifications. Increases in onshore
                 concentrations of air pollutants are estimated to be between 1 and 14.5 /Lgm-3 (box model steady
                 concentrations). This concentration will have minimal impact during winter because onshore winds occur only
                 37 percent of the time, and a maximum impact in summer, when onshore winds occur 61 percent of the time.

                 (5) Impacts on Coastal and Marine Mammals

                 (a) Marine Mammals

                 Nonendangered and Nonthreatened Species

                     This Cumulative Analysis considers the effects of impact-producing factors related to the Central Gulf
                 proposed action, prior and future OCS sales, State oil and gas activity, commercial fishing, removal of live
                 specimens for public display, and pathogens that may occur and adversely affect nonendangered and
                 nonthreatened cetaceans (cetaceans include whales and dolphins) in the same general area that may be
                 affected by OCS oil and gas activity located in the CPA.
                     Sections providing supportive material forthe nonendangered and nonthreatened cetacean analysis include
                 Sections III.B.3. (description of cetaceans), IV.A.2.a.(I) (seismic operations), IV.A.2.a.(3) (structure removal),
                 IV.A.2.c. (support activities), TV.A-2.d.(5) (offshore discharges), IV.C.3. (oil spills), and IV.C.5. (oil-spin
                 response activities).
                     An estimated 76.6 MMbbl of drilling muds, 182 MMbbl of drill cuttings, and 12.2 Bbbl of' produced waters
                 are assumed to be generated as a result of the proposed action plus prior and future OCS sales (Table IV-7).
                 These effluents are routinely discharged into offshore marine waters and are regulated by the U.S.
                 Environmental Protection Agency's NPDES permits. An unknown but expected substantial amount would also
                 be discharged into nearshore waters from State oil and gas activities. It is expected that nonendangered
                 cetaceans will periodically interact with these discharges. Direct effects to cetaceans are. expected to be
                 sublethal, and effects to cetacean food sources are not expected due to the rapid offshore dilution and
                 dispersion of operational discharges. It is expected that operational discharges will periodically contact and
                 affect nonendangered cetaceans.










                                                                                                                              IV-315

                     It is assumed that helicopter traffic will occur on a regular basis, averaging about a million trips per year.
                 The FAA Advisory Circular 91-36C encourages the use of fixed-wing aircraft above an elevation of 152 m and
                 helicopters above 300 m. It is expected that at these elevations no cetaceans will be affected by OCS helicopter
                 traffic. It is expected that helicopter traffic will rarely disturb and affect nonendangered cetaceans because of
                 special prolifloitions and adherence to the general, FAA-recommended minimum ceiling of 300 m.
                     It is assumed that, during the peak year, 36,000 OCS-related oil/gas service-vessel trips, 2 shuttle tanker
                 trips, and 299 barge traffic trips will occur as a result of the proposed action, plus prior and future OCS sales
                 in the CPA (Table IV-7). Noise from service-vessel traffic may elicit a startle reaction from cetaceans or mask
                 their sound reception. This effect is sublethal and, at worst, of a short-term, temporary nature. Service vessels
                 could collide with and directly impact cetaceans, but due to dolphin maneuverability and echo-location,
                 encounters of this type seldom occur. Cetaceans can avoid service vessels, and operators can avoid cetaceans.
                 It is expected that service-vessel traffic will rarely contact and affect nonendangered cetaceans.
                     It is assumed that, during the peak year, 400 exploration and delineation wells and 235 development wells
                 will be drilled as a result of the proposed action, plus prior and future OCS sales in the CPA (Table IV-7), and
                 will produce sounds at intensities and frequencies that could be heard by cetaceans. It is estimated that noise
                 from drilling activities will last no longer than two months at each location. However, the decibel level of these
                 sounds dissipates to the tolerance of most cetaceans within 15 m of the source. Odontocetes (toothed whales)
                 communicate at higher frequencies than the dominant sounds generated by drilling platforms. Sound levels
                 in this range are not likely to be generated by drilling operations (Gales, 1982). The effects on cetaceans from
                 platform noise are expected to be sublethal. It is expected that drilling noise will rarely disturb and affect
                 nonendangered cetaceans.
                     Explosive platform removals can interfere with communication, disturb behavior, reduce hearing sensitivity,
                 or cause hemorrhaging in cetaceans. It is estimated that, during the peak year, 94 structures will be removed
                 by explosives from the CPA as a result of the proposed action, plus prior and future OCS sales. It is expected
                 that structure removals will cause sublethal effects on cetaceans. No mortalities are expected because of the
                 MMS guidelines for explosive removals (USDOI, MMS, 1990a, Appendix B). It is expected that structure
                 removals will periodically disturb and affect nonendangered cetaceans.
                     Seismic surveys use airguns to generate pulses. It is assumed that only this method will be used in seismic
                 surveys as a result of the proposed action, plus prior and future OCS sales (Section MA-2.). It is expected
                 that effects on cetaceans from seismic surveys are primarily sublethal, constituting short-term avoidance
                 behavior.
                     Oil spills can adversely affect cetaceans, causing skin and eye irritation, asphyxiation from inhalation of
                 toxic fumes, food reduction or contamination, oil ingestion, and displacement from preferred habitats or
                 migration routes. In the event that oiling of cetaceans should occur from oil spills greater than or equal to
                 1,000 bbl, the effects would primarily be sublethal; few mortalities are expected. The effects of oil spills less
                 than 1,000 bbl are expected to be solely sublethal due to the small area affected and their rapid dispersion.
                 It is expected that the extent and severity of effects from oil spills of any size will be lessened by improved
                 coastal oil spill contingency planning (Section IV.C.5.) and by active avoidance of off spills by cetaceans.
                     Section IV.C.3. estimates the mean number of spills less than 1,000 bbl occurring as a result of the
                 proposed action, plus prior and future OCS sales in the CPA. It is assumed that 24 spills greater than 1 and
                 less than or equal to 50 bbI will occur offshore each year, that a few will occur in each offshore Subarea, and
                 that a few will contact land. It is assumed that one spill greater than 50 and less than 1,000 bbI will occur each
                 year and that it will disperse rapidly. No spills greater than 50 and less than 1,000 bbl are assumed to occur
                 and contact nearshore areas. Although an interaction with spills less than 1,000 bbI is expected, primarily
                 sublethal effects are expected. It is expected that spills greater than 50 and less than 1,000 bbl will periodically
                 contact and affect nonendangered cetaceans.
                     It is assumed that 44 crude oil spills greater than or equal to 1,000 bbl will occur as a result of import
                 tankering and the proposed action, plus prior and future OCS sales in the Gulf of Mexico (Table IV-7). Table
                 IV-21 identifies the estimated risk of one or more off spills greater than or equal to 1,000 bbI occurring and
                 contacting within 10 days areas where cetaceans have been surveyed. There is a 59 percent probability that
                 an oil spill greater than or equal to 1,000 bbI will occur and contact within 10 days cetacean habitats at or
                 beyond the shelf break of the CPA. There is a 28 percent probability that an oil spill greater than or equal to










                IV-316

                1,000 bbI will occur and contact within 10 days areas of the Mississippi Delta where cetaceans have been
                sighted. Although an interaction with spills greater than or equal to 1,000 bbl is expected, infrequent
                mortalities are expected with primarily sublethal effects. It is assumed that an oil spill greater than or equal
                to 1,000 bbl will occur and contact within 10 days periodically and affect nonendangered cetao-.ans in the CPA.
                     Commercial fishing equipment entangles and drowns cetaceans during routine activities or during accidental
                "ghost" fishing by lost or discarded gear (Tucker and Associates, Inc., 1990). Although the event of incidental
                take and death during "ghost" fishing is largely undocumented, it has been noted as an activity of concern by
                the NMFS and the Marine Mammal Commission. It is expected that both routine commerchil and accidental
                "ghost" fishing will cause few mortalities of cetaceans. It is expected that commercial fishing equipment win
                periodically contact and affect nonendangered cetaceans; in the CPA.
                     Nonendangered and nonthreatened cetaceans are captured and removed for public display and research.
                These activities are concentrated on bottlenose dolphins and not all endeavors are successful. Dolphins
                occasionally elude capture or escape during acquisition. Catch quotas are set by the NMFS to ensure a
                sustainable yield, and capture is occasionally banned if populations are considered depleted. It is assumed that
                bottlenose dolphins will be captured and removed from the CPA. The effects on those dollphins that elude
                or escape capture are expected to be sublethal. It is expected that live capture and removal vdH rarely contact
                and affect nonendangered cetaceans in the CPA.
                     Epidemic die-offs or mass strandings occur in several species of nonendangered cetaceans. The causes are
                difficult to diagnose, as has been the case with abnormal bottlenose dolphin mortality in the Gulf in 1989-1990
                and along the Atlantic Seaboard in 1988 (USDOC, NMFS, 1990b). Naturally occurring and anthropogenic
                toxins have been the hypothesized cause. Sources include algal blooms, oil spills, ocean dumping, industrial
                and municipal effluents, and agricultural runoff. These concentrations are not widespread, and mortalities
                occur in localized populations. It is expected that toxins will periodically contact and affect nonendangered
                cetaceans in the CPA.


                Summary

                     Activities resulting from the Cumulative scenario have a potential to affect nonendangered cetaceans
                detrimentally. These cetaceans, could be impacted by operational discharges, helicopter and vessel traffic,
                platform noise, explosive platform removals, seismic surveys, oil spills, commercial fishing, capture and removal,
                and pathogens. The effects of the majority of these activities are expected to be sublethal. Lethal effects are
                expected only from oil spills greater than or equal to 1,000 bbl, commercial fishing, and pathogens. Oil spills
                of any size as a result of import tankering, the proposed action, and prior and future OCS sales are estimated
                to be infrequent events that will periodically contact nonendangered and nonthreatened cetaceans.
                     The incremental contribution of the proposed action (as analyzed in Section IV.D.La.(5)(a)) to the
                cumulative impact is inconsequential because the effects of sale-specific operational discharges, helicopter and
                service-vessel traffic, and seismic activity are expected to be sublethal. No mortalities are. expected from
                explosive platform removal because of MMS guidelines. Lethal effects are expected only from oil spills greater
                than or equal to 1,000 bbl that will seldom contact nonendangered and nonthreatened cetacA*ans.

                Conclusion


                     The impact of the Cumulative Case scenario on nonendangered and nonthreatened cetaceans within the
                potentially affected area is expected to result in a decline in species numbers or temporary displacement from
                their current distribution, a decline or displacement that will last more than one generation.

                Endangered and 7hreatened Species

                     This Cumulative Analysis considers the effects of activities related to the Central Gulf proposed action,
                prior and future OCS sales, State oil and gas operations, migration, and recreational whale-watching on the
                blue, sei, humpback, fin, and sperm whale. The sperm whale is the species most seen in the Gulf of Mexico.










                                                                                                                           IV-317

                    The major impact-producing factors are described in the preceding section (Section IV.D.Ld.(5)(a),
                nonendangered and nonthreatened species). Sections providing supportive material'for the endangered
                cetacean analysis include III.B.3. (description of cetaceans), IV.A.2.a.(l) (seismic operations), IV.A.2.a.(3)
                (structure removal), IV.A.2.c. (support activities), IV.A.2.d.(5) (offshore discharges), IV.C.3. (oil spills), and
                IV.C.5. (oil-spill response activities).
                    An estimated 76.6 MMbbI of drilling muds, 18.2 MMbbI of drill cuttings, and 12.2 Bbbl of produced waters
                are assumed to be discharged annually as a result of the proposed action, plus prior and future OCS sales
                (Table IV-7). These effluents are routinely discharged into offshore marine waters and are regulated by the
                U.S. Environmental Protection Agency's NPDES permits. An unknown but expected substantial amount would
                also be discharged into nearshore waters from State oil and gas activities. It is expected that endangered
                cetaceans will periodically interact with these discharges. Direct effects to cetaceans are expected to be
                sublethal and effects to cetacean food sources are not expected due to the rapid offshore dilution and
                dispersion of operational discharges. It is expected that operational discharges will periodically contact and
                affect endangered cetaceans.
                    It is assumed that helicopter traffic will occur on a regular basis, averaging about a million trips a year.
                The FAA Advisory Circular 91-36C encourages the use of fixed-wing aircraft above an elevation of 152 in and
                helicopters above 300 in. It is expected that at these elevations no cetaceans will be affected by OCS helicopter
                traffic. It is expected that helicopter traffic will rarely disturb and affect endangered cetaceans because of
                special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 in.
                    It is assumed that, during the peak year, 36,000 OCS-related oil/gas, service-vessel trips, 2 shuttle tanker
                trips, and 299 barge traffic trips will occur as a result of the proposed action, plus prior and future OCS sales
                in the CPA (Table IV-7). Noise from service-vessel traffic may elicit a startle reaction from cetaceans or mask
                their sound reception. This effect is sublethal, and at worst, of a short-term, temporary nature. Service vessels
                could collide with and directly impact cetaceans, but due to dolphin maneuverability and echo-location,
                encounters of this type seldom occur. Cetaceans can avoid service vessels and operators can avoid cetaceans.
                It is expected that service-vessel traffic will rarely contact and affect endangered cetaceans.
                    It is assumed that, during the peak year 400, exploration and delineation wells and 235 development wells
                will be drilled as a result of the proposed action, plus prior and future OCS sales in the CPA (Table IV-7), and
                will produce sounds at intensities and frequencies that could be heard by cetaceans. It is estimated that noise
                from drilling activities will last no longer than two months at each location. However, the decibel level of these
                sounds dissipates to the tolerance of most cetaceans within 15 in of the source. Odontocetes communicate at
                higher frequencies than the dominant sounds generated by drilling platforms. Sound levels in this range are
                not likely to be generated by drilling operations (Gales, 1982). The effects on cetaceans from platform noise
                are expected to be sublethal. It is expected that drilling noise will rarely disturb and affect endangered
                cetaceans.
                    Explosive platform removals can interfere with communication, disturb behavior, reduce hearing sensitivity,
                or cause hemorrhaging in cetaceans. It is estimated, that during the peak year, 94 structures will be removed
                by explosives from the CPA as a result of the proposed action, plus prior and future OCS sales. It is expected
                that structure removals will cause sublethal effects on cetaceans. No mortalities are expected because of the
                MMS guidelines for explosive removals (USDOI, MMS, 1990a, Appendix B). It is expected that structure
                removals will periodically disturb and affect endangered cetaceans.
                    Seismic surveys use airguns to generate pulses. It is assumed that only these methods will be used in
                seismic surveys as a result of the proposed action, plus prior and future OCS sales (Section IV.A.2.). It is
                expected that effects on cetaceans from seismic surveys are primarily sublethal, constituting short-term
                avoidance behavior.
                    Oil spills can adversely affect cetaceans, causing skin and eye irritation, asphyxiation from inhalation of
                toxic fumes, food reduction or contamination, oil ingestion, and displacement from preferred habitats or
                migration routes. In the event that oiling of cetaceans should occur from oil spills greater than or equal to
                1,000 bbl, the effects would primarily be sublethal; few mortalities are expected. The effects of oil spills less
                than 1,000 bbI are expected to be solely sublethal due to the small area affected and their rapid dispersion.
                It is expected that the extent and severity of effects from oil spills of any size will be lessened by improved
                coastal oil-spill contingency planning (Section IV.C.5.) and by active avoidance of oil spills by cetaceans.










                 IV-318

                     Section IV.C3. estimates the mean number of spills less than 1,000 bbI occurring as a result of the
                 proposed action, plus prior and future OCS sales in the CPA. It is assumed that 24 spills greater than 1 and
                 less than or equal to 50 bbl will occur each year, that a few will occur in each offshore subarea, and that a few
                 will contact land. It is assumed that one spill greater than 50 and less than 1,000 bbl will occur each year and
                 that it will not occur in each subarea, that it will not contact land, and that it will disperse rapidly. No spills
                 greater than 50 and less than 1,000 bbI are assumed to occur and contact nearshore areas. Although an
                 interaction with spills less than 1,000 bbl is estimated, only sublethal effects are expected. lit is expected that
                 spills less than 1,000 bbI will periodically contact and affect endangered cetaceans.
                     It is assumed that 44 crude oil spills greater than or equal to 1,000 bbl will occur as a result of import
                 tankering and the proposed action, plus prior and future OCS sales in the Gulf of Mexico (Table IV-19). Table
                 IV-21 identifies the estimated risk of one or more oil spills greater than or equal to 1,000 bb occurring and
                 contacting within 10 days areas where cetaceans have been surveyed. There is a 59 percent probability that
                 an oil spill greater than or equal to 1,000 bbl will occur and contact within 10 days cetacean habitats at or
                 beyond the shelf break of the CPA. There is a 28 percent probability that an oil spill greater than or equal to
                 1,000 bbI will occur and contact within 10 days areas of the Mississippi Delta where cetaceans have been
                 sighted. Although an interaction with spills greater than or equal to 1,000 bbI is estimated, primarily sublethal
                 effects are expected with infrequent mortalities. It is assumed that an oil spill greater than or equal to 1,000
                 bbI will periodically contact and affect endangered cetaceans in the CPA.
                     It is assumed that the migratory behavior of the great whales exposes them to potential adverse impacts
                 generated from all Gulf of Mexico and Atlantic OCS planning areas, as well as routine activities and accidental
                 events originating from Central America, North America, Europe, and the Caribbean. The incremental
                 contribution of each impact cannot be determined nor its effect estimated because of the multitude of sources.
                     Recreational whale-watching is an applicable impact-producing factor only to large cetaceans and great
                 whales. Although whale-watching vessels have the potential to displace or collide with whales, no incidents of
                 this nature have been reported. These activities are not popular in the Gulf; however, it is assumed that they
                 regularly occur on the Eastern Seaboard (Freeman, 1991). It is expected that these activities cause sublethal
                 effects. It is estimated that recreational whale-watching activities rarely contact and affect great whales that
                 migrate to the CPA.

                 Summary

                     Activities resulting from the Cumulative scenario have a potential to affect endangered and threatened
                 cetaceans detrimentally. These cetaceans could be impacted by operational discharges, helicopter and vessel
                 traffic, platform noise, explosive platform removals, seismic surveys, oil spills, oil-spill response operations,
                 natural and anthropogenic activities contacted during migration, and recreational whale-watching. The effects
                 of the majority of these activities are expected to be sublethal. Lethal effects are expected only from oil spills
                 greater than or equal to 1,000 bbl. Oil spills of any size as a result of import tankering, the proposed action,
                 and prior and future OCS sales are estimated to be infrequent events that will periodically contact endangered
                 cetaceans.
                     The incremental contribution of the proposed action (as analyzed in Section IV.D.La.(5)(a)) to the
                 cumulative impact is inconsequential because the effects of sale-specific operational discharges, helicopter and
                 service-vessel traffic, and seismic activity are expected to be sublethal. No mortalities arte expected from
                 explosive platform removal because of MMS guidelines. Lethal effects are expected only fromi oil spills greater
                 than or equal to 1,000 bbI that will rarely contact endangered and threatened cetaceans.

                 Conclusion


                     The impact of the Cumulative Case scenario on endangered and threatened cetaceans within the
                 potentially affected area is expected to result in a decline in species numbers or temporary displacement from
                 their current distribution, a decline or displacement that will last more than one generation.










                                                                                                                             IV-319

                (b) Alabama, Choctawhatchee, and Perdido Key Beach Mice

                     This Cumulative Analysis considers the effects of impact-producing factors related to the Central Gulf
                proposed action, prior and future OCS sales, State off and gas activity, alteration and destruction of habitat,
                competition, predation, and natural catastrophe on the Alabama, Choctawhatchee, and Perdido Key beach
                mice.
                     The effects from the major impact-producing factors are discussed in detail in Section IV.D.La.(5)(b) and
                are described below. Sections providing supportive material for the Alabama, Choctawhatchee, and Perdido
                Key beach mice analysis include III.A.2. (meteorological conditions), III.B.3.(b) (description of Alabama,
                Choctawhatchee, and Perdido Key beach mice), IV.B.1.C. (other major coastal/onshore activities), IV.C.3. (oil
                spills), and IV.C.5. (off-spill response activities).
                     Direct contact with spilled oil can cause skin and eye irritation, asphyxiation from inhalation of toxic fumes,
                food reduction, food contamination, oil ingestion, and displacement from preferred habitat, which is not on the
                beach, but behind the barrier dunes. An oil spill would have to breach the dunes to reach either the mice or
                their preferred habitat. This could occur only if an oil spill coincided with a storm surge.
                     Section IV.C.3. estimates the mean number of coastal spills less than 1,000 bbl occurring as a result of the
                proposed action, plus prior and future OCS sales in the CPA. It is assumed that one spill greater than one
                and less than or equal to 50 bbl will occur onshore each year. It is assumed that one spill greater than 50 and
                less than 1,000 bbl will occur onshore every 10 years. Although an interaction with spills less than 1,000 bbl
                may occur, only sublethal effects are expected. It is expected that spills will seldom breach barrier dunes and
                contact or affect beach mice or their habitats.
                     It is assumed that 44 crude oil spills greater than or equal to 1,000 bbl win occur as a result of import
                tankering and the proposed action, plus prior and future OCS sales in the Gulf of Mexico (Table IV-20). It
                is expected that an oil spill greater than or equal to 1,000 bbl could breach beach barriers only if the spill
                coincided with a storm surge strong enough to lift oil over the foredunes. Table IV-21 identifies the estimated
                risk of one or more oil spills greater than or equal to 1,000 bbl occurring and contacting within 10 days coastal
                areas near beach mice habitats. The highest estimated probability of one or more spills greater than or equal
                to 1,000 bbl occurring and contacting within 10 days nearshore areas (coastline) along the Central Gulf is 85
                percent. There is a 3 percent probability of an off spill greater than or equal to 1,000 bbl occurring and
                contacting within 10 days the coastal areas of the Alabama, Choctawhatchee, and Perdido Key beach mice
                (Mobile Bay, Perdido Bay seagrass beds, and Escambia County). Although an interaction with spills greater
                than or equal to 1,000 bbl is estimated, primarily sublethal effects are expected with infrequent mortalities.
                It is expected that oil spills greater than or equal to 1,000 bbl will rarely contact or affect beach mice or their
                habitats.
                     Vehicular traffic associated with off-spill cleanup activities can degrade preferred habitat and cause
                displacement from these areas. The home range of the beach mice is within Perdido Key State Preserve
                (Florida), Grayton Beach State Recreational Area (Florida), St. Andrews State Recreation Area (Florida), Gulf
                Islands National Seashore (Alabama), and Gulf State Park (Alabama), which receive particular consideration
                during off-spill cleanups. Because of the critical designation and general status of those areas, oil-spill
                contingency plans include special notices to minimize adverse effects from vehicular traffic during cleanup
                activities and to maximize the protection efforts to prevent contact of these areas with spilled oil (Section
                IV.C.5.). Vehicular traffic associated with oil-spill cleanup activities is assumed to contact beach mouse habitat
                in the event of a spill greater than or equal to 1,000 bbl breaching barrier dunes. Table IV-21 indicates that
                there is a 3 percent probability of an oil spill greater than or equal to 1,000 bbl occurring and contacting within
                10 days the coastal areas of Alabama, Choctawhatchee, and Perdido Key beach mice (Mobile Bay, Perdido Bay
                seagrass beds, and Escambia County). It is expected that vehicular traffic associated with off-spill cleanup
                activities rarely contacts or affects beach mice or their habitats.
                     Non-OCS operations, such as dredge-and-fill activities and natural catastrophes, can cause the loss of
                Alabama, Choctawhatchee, and Perdido Key beach mice habitats, e.g., barrier islands and nearshore wetland
                areas. Non-OCS activities, such as predation from both feral and nonferal domestic cats and dogs, and










                 IV-320

                 competition by common house mice, directly impact the Alabama, Choctawhatchee, and Perdido Key beach
                 mice.
                     Dredge-and-fill activities occur throughout the nearshore areas of the United States. They range in scope
                 from propeller dredging by recreational boats to large-scale navigation dredging and fill for land reclamation.
                 Natural catastrophes, including storms, floods, droughts, and hurricanes, can result in substantial damage to
                 Alabama, Choctawhatchee, and Perdido Key beach mice habitats. Sublethal effects on beach mice are
                 expected from these activities. It is expected that dredge-and-fill activities and natural wastrophes will
                 periodically contact and affect beach mice habitats.
                     Predation by dogs and cats and competition by house mice have a substantial effect on the Alabama,
                 Choctawhatchee, and Perdido Key beach mice. The number of mortalities is unknown, and the nature of the
                 activities causes unreliable estimates. However, these activities are considered the most damaging to Alabama,
                 Choctawhatchee, and Perdido Key beach mice populations in the Gulf of Mexico (USDOL FWS, 1987). Both
                 mortalities and sublethal effects are expected from these activities. It is expected that predation and
                 competition will periodically contact and affect Alabama, Choctawhatchee, Perdido Key beach mice.

                 Summary

                     Activities resulting from the Cumulative scenario have a potential to affect Alabama, Cho,,tawhatchee, and
                 Perdido Key beach mice detrimentally. Those activities include oil spills, oil-spill response activities, alteration
                 and destruction of habitat, natural catastrophes, predation, and competition. The effects of the majority of
                 these activities are expected to be sublethal. Lethal effects are expected from oil spills greater than or equal
                 to 1,000 bbl, predation, and competition. Oil spills of any size as a result of import tankeriag, the proposed
                 action, and prior and future lease sales are expected to be periodic events that will rarely contact beach mice
                 or their habitats. The incremental contribution of the proposed action (as analyzed in Section IVD.La.(5)(b))
                 to the cumulative impact level is negligible because it is expected that there will be no interaction between oil
                 spills and oil-spill response activities and endangered and threatened Alabama, Choctawhatchee, and Perdido
                 Key beach mice.

                 Conclusion


                     The impact of the Cumulative Case scenario on Alabama, Choctawhatchee, and Perdido Key beach mice
                 within the potentially affected area is expected to result in a decline in species numbers or temporary
                 displacement from their current distribution, a decline or displacement that will last more than one generation.

                 (6) Impacts on Marine Turtles

                     This Cumulative Analysis considers the effects of impact-producing factors related to the Central Gulf
                 proposed action, prior and future OCS sales, State off and gas activity, migration, dredge-and-fill operations,
                 natural catastrophe, pollution, commercial fishing, hopper dredge operation, recreational boat traffic, and
                 human consumption on the loggerhead, Kemp's ridley, hawksbill, green, and leatherback marine turtles.
                     The effects from the major impact-producing factors are discussed in detail in Section IV.D. La.(6) and are
                 described below. Sections providing supportive material for the marine turtle analysis include III.A.2.
                 (meteorological conditions), III.B.4. (description of marine turtles), IV.A.2.a.(3) (structure removal), IV.A.2.c.
                 (support activities), IV.A.2.d.(5) (offshore discharges), IV.B.l.c. (other major coastal/onshoreactivities), IV.C.3.
                 (oil spills), and IV.C.5. (oil-spill response activities).
                     Anchoring, structure installation, pipeline placement, dredging, and operational discharges as a result of
                 the proposed action, plus prior and future OCS sales, may adversely affect marine turtle habitat through
                 destruction of nearshore wetland areas and live-bottom communities. The impact under the Cumulative case
                 scenario from these activities is analyzed in detail in Sections IV.D.1.c.(1)(b) and IV.D.l.c.(2)(a). Sublethal
                 effects on marine turtles or their habitats are expected from these impact-producing factors.










                                                                                                                             IV-321

                     To summarize the effects on wetlands and estuaries, it is expected that 500 ha of coastal areas will be
                 affected by oil spills as a result of the proposed action, prior and future OCS sales, and State oil and gas
                 activities. An estimated dieback of up to 50 ha of wetlands, mainly along the Texas and Louisiana coasts, will
                 occur from contact with spilled off. Up to 80 ha of wetlands could be eroded as a result of maintenance
                 dredging and deepening of navigation channels in coastal Louisiana. Three new pipeline landfalls will affect
                 a total of 16 ha of wetlands in Jackson County, Mississippi (Pascagoula), and 32 ha of wetlands in the Mobile,
                 Alabama, area. The main cause of wetland and estuary loss within the Gulf of Mexico are sediment
                 deprivation and rapid coastal submergence.
                     To summarize the effects on nesting beaches, it is expected that minor changes in beach profiles will occur
                 as a result of oil-spill cleanup operations that remove some sand from the littoral zone. Prespill configurations
                 are expected to be reestablished within 2-4 months. Recreational usage of accessible beaches near large
                 population centers, such as in Texas, will result in damage to beach features. The main causes of nesting beach
                 loss within the Gulf of Mexico are the reduction in sediment being delivered to the coastal littoral system, rapid
                 rate of relative sea level rise, and continued coastal urbanization. To summarize the effects on seafloor
                 habitats, little or no damage is expected to the physical integrity, species, diversity, or biological productivity
                 of topographic features. Small areas of 5-10 M2 would be affected for less than two years, probably on the
                 order of four weeks. However, damage is expected to one or more components of physical integrity, species
                 diversity, or biological productivity in the regionally common habitats or the communities of live-bottom areas.
                 Fewer han five live-bottom areas of 5_10 M2 would be affected for 10 years. Offshore operational discharges
                 are not lethal to marine turtles and are diluted and dispersed rapidly within 1 km of the discharge point to the
                 extent that adverse effects to marine turtle food sources do not occur (API, 1989; NRC, 1983). It is expected
                 that effects on marine turtles from anchoring, structure installation, pipeline emplacement, and dredging will
                 be indistinguishable from the long-term (25-50 years) natural variability within populations of marine turtles.
                 It is expected that marine turtles will avoid 5-10 M2 of topographic feature areas for up to a month and that
                 this avoidance of impoverished foraging areas will have no effect on marine turtles. It is expected that marine
                 turtles will avoid 5-10 M2 of live-bottom areas for up to 10 years and that this avoidance of impoverished
                 foraging areas will have no effect on marine turtles. The suspended particulate matter in operational
                 discharges offshore is expected to cause sublethal effects by inhibition of the ability of marine turtles to locate
                 their prey visually within 1 km of the discharge point for the short time period (less than one hour) spent
                 traversing the plume. Based on the aforementioned analyses, the estimate is that anchoring, structure
                 installation, pipeline placement, dredging, and operational discharges will periodically contact marine turtles
                 or their habitats.
                     Marine turtles can become entangled in or ingest trash and debris, which may result in injury or mortality.
                 It is assumed that some OCS-related trash and debris will be accidentally lost into the Gulf and available for
                 interaction with marine turtles. Although mortalities could occur, primarily sublethal effects are expected. It
                 is further expected that OCS oil- and gas-related trash and debris will rarely interact with and affect marine
                 turtles.
                     Explosive platform removals can cause capillary damage, disorientation, and loss of motor control, and fatal
                 injuries in marine turtles. It is estimated that, during the peak year, 94 structures will be removed by using
                 explosives from the CPA as a result of the proposed action, plus prior and future OCS sales (Table IV-7). It
                 is assumed that some of the platform removals will occur beyond the continental shelf. As benthic feeders,
                 Gulf of Mexico hard-shell marine turtles do not use habitats beyond the shelf break. Although the pelagic life
                 stages of all marine turtles use these habitats, there is no correlation between marine turtles and the presence
                 of offshore structures beyond the shelf break. It is expected that structure removals will cause sublethal effects
                 on marine turtles. No mortalities are expected because of the MMS guidelines for explosive removals (USDOI,
                 MMS, 1990a, Appendix B) and because removals occur away from preferred offshore habitats. It is expected
                 that structure removals will rarely disturb and affect marine turtles.
                     It is assumed that, during the peak year of the proposed action, 36,000 OCS-related oil and gas service-
                 vessel trips, 2 shuttle tanker trips, and 299 barge trips will occur in the CPA as a result of the proposed action,
                 plus prior and future OCS sales (Table IV-7). Noise from service-vessel traffic may elicit a startle reaction
                 from marine turtles. This effect is sublethal and, at worst, of a short-term, temporary nature (NRC, 1990).
                 Collision between service vessels and surfaced marine turtles would likely cause fatal injuries. It is assumed










                 IV-322

                 that service-vessel traffic and marine turtles will infrequently be in close proximity. Although a low percentage
                 of stranded marine turtles have shown indications of vessel collision, it cannot be determined what types of
                 vessel were involved and whether these injuries occurred before or after death. Marine turtles are known to
                 spend less than 5 percent of their time at the surface and to sound when large vessels approach. In addition,
                 marine vessel operators can avoid marine turtles. It is expected that service-vessel trafficwill rarely contact
                 and affect marine turtles.
                     Oil spills and oil-spill response activities can adversely affect marine turtles by toxic external contact, toxic
                 ingestion or blockage of the digestive tract, asphyxiation, entrapment in tar or oil slicks, habitat destruction,
                 and displacement from preferred habitats. Oil-spill response activities, such as vehicular andvessel traffic, are
                 assumed to contact marine turtle habitat, such as shallow areas of turtle grass beds and five-bottom
                 communities, in the event of contact with an off spill greater than or equal to 1,000 bbL Sublethal effects are
                 expected due to the particular consideration these areas receive during oil-spill cleanup to minimize adverse
                 effects from traffic during cleanup activities and to maximize protection efforts to prevent contact of these areas
                 with spilled off. It is expected that off-spill response activities will rarely contact and affect marine turtle
                 habitat.
                     In the event that oiling of marine turtles should occur from off spills greater than or equal to 1,000 bbl,
                 the effects would primarily be sublethal; few mortalities are expected. The effects of oil spills less than 1,000
                 bbl are expected to be solely sublethal due to the small area affected and their rapid dispersion. It is expected
                 that the extent and severity of effects from oil spills of any size will be lessened by improved coastal oil-spin
                 contingency planning (Section IV.C.5.).
                     Section IV.C.3. estimates the mean number of spills less than 1,000 bbl occurring as, a result of the
                 proposed action, plus prior and future OCS sales in the CPA. It is assumed that 24 spills greater than I and
                 less than or equal to 50 bbl will occur offshore each year, that a few will occur in each offshore subarea, and
                 that a few will contact land. It is assumed that I spill greater than 50 and less than 1,000 bbl win occur each
                 year, that they will not occur in each subarea, that they will not contact land, and that they will disperse rapidly.
                 Although an interaction with small spills is estimated, only sublethal effects are expected. It is assumed that
                 small spills will periodically contact and affect marine turtles.
                     It is assumed that 44 crude oil spills greater than or equal to 1,000 bbl will occur as a result of import
                 tankering and the proposed action, plus prior and future OCS sales in the Gulf of Mexico (Table IV-19).
                 Section IV.C.3. identifies the estimated risk of one or more oil spills greater than 1,000 bbl occurring and
                 contacting marine turtle habitat. There is a 54 percent probability that an oil spill greater than or equal to
                 1,000 bbl will occur and contact within 10 days marine turtle habitats in nearshore areas of the CPA
                 (Plaquemines Parish). There is a 96 percent probability that an oil spill greater than or equal to 1,000 bbl will
                 occur and contact within 10 days pelagic turtle habitat beyond the shelf break of the CPA. Although an
                 interaction with spills greater than or equal to 1,000 bbl is estimated, primarily sublethal effects are expected
                 with infrequent mortalities. It is expected that an oil spill greater than or equal to 1,000 bbl will occur and
                 contact periodically and affect nonendangered cetaceans in the CPA.
                     Non-OCS operations, such as dredge-and-fill activities, pollution, and natural catastrophes, can cause the
                 loss of marine turtle habitats, e.g., nesting beaches, nearshore wetland areas, and live-bottom communities.
                 Non-OCS operations such as commercial fishing, hopper dredge activities, nearshore boat traffic, human
                 consumption, and loss of anthropogenic debris directly impact marine turtles. Dredge-and-fia activities occur
                 throughout the nearshore areas of the United States and range in scope from propeller dredging by
                 recreational boats to large-scale navigation dredging and fill for land reclamation. Pollution resulting in loss
                 of turtle grass beds includes the alteration of salinity, as in Florida Bay, as well as man-induced increases in
                 turbidity, witnessed in Tampa Bay. Disturbances to nesting beaches occur from a variety of sources, including
                 construction, vehicle traffic, and deprivation of sand. Natural catastrophes, including storms, floods, droughts,
                 and hurricanes, can result in substantial damage to sea turtle habitat. Sublethal effects on marine turtles are
                 expected from these activities. It is expected that dredge-and-fill activities, pollution, and natural catastrophes
                 will periodically contact and affect marine turtle habitats.
                     Drowning that results from forced submergence in commercial fish trawls has a substantial effect on marine
                 turtle populations in the Gulf of Mexico. Shrimp trawling in the southeastern United States has received
                 extensive scrutiny because of its incidental turtle catch. The National Research Council (1990) has identified










                                                                                                                             IV-323

                shrimp trawling as the greatest cause of human-induced mortality in marine turtles. The use of turtle excluder
                devices is legislatively mandated in order to decrease losses. Dismemberment of turtles by hopper dredging
                has resulted in turtle mortalities. Specific dredging projects include the Canaveral Ship Channel in Florida,
                the King's Bay Submarine Channel in Georgia, and channel dredging of ports throughout the Gulf. Data from
                the Sea Turtle Stranding Network indicate a large number of marine turtles are hit by boats. In the Eastern
                Gulf, the incidence of stranded marine turtles exhibiting indications of vessel collision has been related to the
                volume of recreational boat traffic. However, the number of mortalities caused by collisions is unknown. The
                human consumption of turtle eggs, meat, or by-products occurs worldwide (Mack and Duplaix, 1979, Cato et
                al., 1978). Human use is probably substantial, but the frequently illegal nature of the activity suggests unreliable
                estimates of mortality. In addition to the incremental amount of trash and debris generated by the proposed
                action, plus prior and future OCS sales, trash and debris that could affect marine turtles find their way into the
                Gulf of Mexico from both commercial and recreational water traffic in the Gulf of Mexico, South and Central
                America, and North Africa. The volume of marine debris from these sources is unknown (USDOC, NMFS,
                1989b; Heneman and the Center for Environmental Education, 1988). Both mortalities and sublethal effects
                on marine turtles are expected from these activities. It is expected that hopper dredge activities, nearshore
                boat traffic, human consumption, and loss of anthropogenic debris will periodically contact and affect marine
                turtles.
                    It is assumed that the migratory behavior of marine turtles exposes them to potential adverse impacts
                generated from all Gulf of Mexico and Atlantic OCS planning areas, as well as routine and accidental events
                originating from Central America, North America, Europe, and the Caribbean. The incremental contribution
                of each impact cannot be determined, nor its effect estimated, because of the multitude of sources.

                Summary

                    Activities resulting from the Cumulative scenario have a potential to affect marine turtles detrimentally.
                Those activities include anchoring, structure installation, pipeline placement, dredging, operational discharges,
                vessel traffic, explosive platform removals, oil-spill response operations, oil spills, dredge-and-ffil operations,
                natural catastrophes, pollution, hopper dredge operation, recreational boat traffic, commercial fishing, human
                consumption, and natural and anthropogenic activities contacted during migration. The effects of the majority
                of these activities are expected to be sublethal. Lethal effects are expected from oil spills greater than or equal
                to 1,000 bbl, hopper dredge operation, commercial fishing, and human consumption. Oil spills of any size as
                a result of import tankering, the proposed action, and prior and future OCS sales are estimated to be
                infrequent events that will periodically contact endangered cetaceans.
                    The incremental contributionof the proposed action (as analyzed in Section IV.D.l.a.(6)) to the cumulative
                impact is inconsequential because the effects of sale-specific anchoring, structure installation, pipeline
                placement, dredging, operational discharges, service-vessel traffic, and trash and debris are expected to be
                sublethal. No mortalities are expected from explosive platform removal because of MMS guidelines. Lethal
                effects are expected only from oil spills greater than or equal to 1,000 bbl and that will rarely contact
                endangered and threatened turtles.

                Conclusion

                    The impact of the Cumulative Case scenario on marine turtles within the potentially affected area is
                expected to result in a decline in species numbers or a temporary displacement from their current distribution,
                a decline or displacement that will last more than one generation.










                 IV-324

                 (7) Impacts on Coastal and Marine Birds

                 (a) Nonendangered and Nonthreatened Species

                     The Gulf of Mexico is populated by migrant and nonmigrant species of coastal and marine birds. This
                 broad category consists of four main groups: seabirds, waterfowl, wading birds, and shorebirds.
                     This Cumulative Analysis considers the status of populations and migratory habits of coastal and marine
                 birds, and the effects of impact-producing factors related to the proposed action; plus those related to prior
                 and future OCS sales; State oil and gas activity-, crude oil imports by tanker; and other commercial, military,
                 recreational offshore, and coastal activities that may occur and adversely affect those populations. Specific
                 types of impact-producing factors considered in the analysis include habitat loss and degradation, oil spills,
                 vessel traffic, pipeline landfalls and coastal construction, fishing gear, and plastic debris.
                     See Section III.B.5.a. for a detailed discussion of coastal and marine birds in the Gulf of Mexico. The four
                 major types of coastal and marine birds have experienced decreases in population (Natonal Geographic
                 Society, 1983a; Spendelow and Patton, 1988).
                     Nonmigrant populations of coastal birds that nest in the CPA are believed to be in decline due to habitat
                 loss from channelization, river control, and subsidence of wetlands (Section III.B.l.b.) (National Geographic
                 Society, 1983a; Turner and Cahoon, 1987; Spendelow and Patton, 1988). Overwintering migrant waterfowl in
                 the CPA are believed to be in decline due to loss and degradation of their nesting habitat in the north-central
                 United States and south-central Canada from encroaching agriculture and drought (Ducks Unlimited, 1989).
                 Should habitat loss cease, the population will return to its pre-impact level within one to two generations.
                 However, the assumed continual loss of crucial habitat will have a deleterious impact on coastal and marine
                 birds during several or all lifestages of migratory and resident species, respectively.
                     Many coastal and marine bird populations in the Gulf of Mexico are overwintering migrants or migrants
                 passing through to wintering grounds outside the country. Waterfowl journey to Gulf feeding grounds using
                 specific flight corridors that run the length of the continental U.S. These corridors terminate in distinct
                 localities along the Gulf Coast. Some waterfowl exhibit a limited degree of coastal movement within their
                 terminal locality, but do not cross planning areas (Bellrose, 1968).
                     Resident wading bird populations are augmented during the winter by migrants from as far away as
                 southern Canada. The Mississippi Delta divides migrating wading birds into distinct east-west groups in the
                 Gulf. Migrating adults of each group terminate and remain in distinct localities along the Gulf Coast, while
                 juveniles usually continue migration outside the country. Migration by Eastern Gulf juveniles begins in southern
                 Florida and terminates in the Caribbean or on the Yucatan Peninsula. Juvenile migration in the Western Gulf
                 begins and continues southwestward along the Gulf Coast, terminating in Mexico and Central. America (Byrd,
                 1978; Ogden, 1978; Ryder, 1978).
                     Resident shorebird and seabird populations are augmented during the winter by migrants from as far away
                 as the North American Arctic Circle. Some species overwinter in discrete localities within a single planning
                 area of the Gulf of Mexico Region, while other species are split into distinct groups east or west of the
                 Mississippi Delta. A few species of shorebirds and seabirds may continue migration. Those in the Western
                 Gulf continue along the coast into Mexico and Central America. Those in the Eastern Gulf continue to the
                 Caribbean. Those that remain on the Western or Eastern Gulf Coast exhibit a limited degree of coastal
                 movement within their terminal locality, but do not cross planning areas (Clapp, 1982a and b; Fritts et al.,
                 1983).
                     Discernible effects to regional populations or subpopulations of these migrating coastal and marine birds
                 as a result of OCS oil and gas activities are not expected because these species have a large areal distribution
                 and do not migrate through more than one planning area.
                     Section IV.C.3. estimates the mean number of offshore spills less than 1,000 bbl occurring as a result of
                 the proposed action, plus prior and future OCS sales in the CPA- Twenty-four offshore spills and 1 onshore
                 spill greater than 1 and less than 50 bbl are assumed to occur each year; a few offshore spills will contact the
                 coastline. It is assumed that 1 offshore spill per year and 1 onshore spill every 5 years greater than 50 and less
                 than 1,000 bbl will occur; none of the offshore spills will contact the coastline. For the purpose of this analysis,










                                                                                                                             IV-325

                it is estimated that spills greater than 50 and less than 1,000 bbl will seldom contact and affect coastal and
                marine birds.
                    It is assumed that 44 crude oil spills greater than or equal to 1,000 bbl will occur in the CPA for the
                Cumulative scenario (Section IV.C3.)-3 from platforms, 4 from pipelines, and 37 from foreign off imports.
                Section IV.C.3. identifies the estimated risk of one or more oil spills greater than or equal to 1,000 bbl resulting
                from the proposed action, prior and future OCS leasing, and import and OCS shuttle tankering occurring and
                contacting, within 10 days, the Gulf of Mexico coastline at 73 percent for imports and 85 percent for the OCS.
                    In the CPA, OCS spills have the highest probability of occurring and contacting within 10 days Plaquemines
                and Terrebonne Parishes, Louisiana (Table IV-21). Imported oil in the CPA has the highest probability of
                contacting the coast in Plaquemines Parish.
                    For purposes of this analysis, it is estimated that oil spills greater than or equal to 1,000 bbl will often
                contact and affect Central Gulf inshore habitats or the coastline. Therefore, this analysis estimates noticeable
                interaction between coastal and marine birds and oil spills.
                    The OCS-related helicopter traffic could disturb feeding, resting, or breeding/nesting behavior of birds, or
                cause abandonment of preferred habitat. This impact-producing factor could contribute to population losses
                by displacement of birds to areas where they may experience increased environmental or physiological stress.
                It is assumed that air traffic will adhere to the FAA Advisory Circular 91-36C, which prohibits flights below
                300 in over national wildlife refuges and national park lands. At this elevation, birds will not be disturbed.
                    Disturbance from vessel traffic in the vicinity of bird feeding and breeding habitats in the CPA will increase
                very little above current levels as a result of OCS-related oil and gas activities. Table IV-7 describes the total
                and peak-year traffic for service vessels, shuttle tankers, and barges. For the purpose of this analysis, it is
                expected that OCS off and gas traffic will seldom affect coastal and marine bird feeding and breeding habitats.
                    The frequency and severity of cumulative impacts will moderately increase as a result of OCS-related
                onshore construction of 3 pipeline landfalls, 48 kin of onshore pipeline, 1 marine terminal, and 2 gas processing
                plants (Table IV-12). An unknown but substantial amount of coastal construction is possible due to further
                urbanization. Coastal development falls under the jurisdiction of individual states.
                    Entanglement in commercial and recreational fishing gear and plastic debris causes injuries and death of
                birds. Coastal storms and hurricanes cause flooding and destruction of nesting areas, resulting in coastal and
                marine bird losses. High levels of oil and organic chemical contamination in the river runoff into the northern
                Gulf of Mexico could cause direct mortality or indirect food loss to avian species. Collision with power lines
                and supporting towers causes additional bird mortality (Avery et al., 1980).

                Summary

                    Habitat loss results in the decline of populations of coastal and marine birds. In the Central Gulf coastal
                zone, habitat loss of nonmigrating birds occurs from channelization, river control, and subsidence of wetlands.
                In the north-central United States and south-central Canada, habitat loss of migrating birds occurs from
                encroaching agriculture and drought
                    The OCS-related helicopter and service-vessel traffic results in displacement of birds from feeding and
                breeding habitats. At worst, the effect of vessel or air traffic during any time of year is of a very short-term
                nature. The FAA Advisory Circular 91-36C regulates flight elevation to no lower than 300 in during the time
                of year of greatest concentration of coastal and marine birds (mid-October to mid-April).
                    Pipeline landfalls and coastal facility construction possibly result in desertion of birds from feeding and
                breeding habitats. Entanglement or ingestion of commercial and recreational fishing plastic debris may injure
                or kill coastal and marine birds.
                    Off spills pose the greatest threat to coastal and marine birds by direct oiling, food source contamination,
                or breeding habitat pollution. It is assumed that 44 oil spills greater than or equal to 1,000 bbl will occur as
                a result of the OCS program and import tankering. The highest estimated probability of oiling, contamination,
                or pollution involving coastal and marine birds is 98 percent
                    The incremental contribution of the proposed action (as analyzed in Section IV.D.La.(7)(a)) to the
                cumulative impact is negligible because the effects of sale-specific helicopter and service-vessel traffic and trash
                and debris are expected to be sublethal. No sale-specific pipeline landfalls and coastal facility construction are











                  IV-326

                  expected to occur or to interact with coastal and marine birds. The effect is expected to tie negligible from
                  sale-related off spills of any size that will seldom contact nonendangered and nonthreatened coastal and marine
                  birds.


                  Conclusion

                      The cumulative effect of the above-listed, impact-producing factors on coastal and marine birds within the
                  potentially affected area is expected to result in a discernible decline in a local coasuil or marine bird
                  population or species, resulting in a change in distribution or abundance. Recruitment will return the
                  population or affected species to their pre-impact level/condition within one to two generations. It is doubtful
                  that this impact will affect regional populations.

                  (b) Endangered and Threatened Species

                      This Cumulative Analysis considers the effects of impact-producing factors related to the Central Gulf
                  proposed action, prior and future OCS sales, State oil and gas operations, migration, and habitat loss and
                  degradation on endangered and threatened birds, including the brown pelican, Arctic peregrine falcon, bald
                  eagle, and piping plover. Specific types of impact-producing factors considered in the analysis. include migratory
                  behavior, helicopter and service-vessel traffic, pipeline landfalls and coastal construction, fishing equipment,
                  plastic debris, and land use changes.
                      The effects from the major impact-producing factors are discussed in detail in Section IVD.La.(7)(b) and
                  are described below. Sections providing supportive material for the endangered and threatened bird analysis
                  include III.B.5.(b) (description of endangered and threatened birds), IV.A.2.c. (support activities), IV.A.2.d.(5)
                  (offshore discharges), IV.A-3.a. (onshore infrastructure, activities, and impacts), IV.C.3. (oilspills), and IV.C.5.
                  (ofl-spill response activities).
                      Endangered birds that nest in the CPA, such as some piping plovers, bald eagles, and brown pelicans, are
                  believed to be in decline due to habitat loss from channelization, river control, and subsidence of wetlands
                  (Section III.B.l.b.) (National Geographic Society, 1983a; Turner and Cahoon, 1987; USDOI, FWS, 1988).
                  Overwintering migrant, endangered birds, such as the Arctic peregrine falcon and some piping plovers, are
                  believed to be in decline due to loss and degradation of their nesting habitat in far northern latitudes of the
                  North American continent (National Geographic Society, 1983a). It is expected that habitat loss win
                  periodically affect endangered birds.
                      As previously described (Section III.B.5.(b)), some piping plovers and the Arctic peregrine falcons are
                  overwintering migrants and/or migrants passing through to wintering grounds outside the country. These birds
                  use specific flight corridors that run the length of the continental U.S. These corridors terminate in distinct
                  localities along the Gulf Coast. Most piping plovers and Arctic peregrine falcons overwinter in discrete
                  localities within a single planning area of the Gulf of Mexico Region. A few of these endangered birds may
                  continue migration. Those in the Western Gulf continue along the coast into Mexico and Central America.
                  Those in the Eastern Gulf continue to the Caribbean. Those that remain on the Western orEastern Gulf coast
                  exhibit a limited degree of coastal movement within their terminal locality, but do not cross planning areas
                  (Clapp, 1982a and b; Fritts et al., 1983). Discernible effects to these endangered birds as a result of OCS oil
                  and gas activities are not expected because these species have a large areal distribution and do not migrate
                  through more than one planning area.
                      It is assumed that helicopter traffic will occur on a regular basis, averaging about a million trips per year.
                  The FAA Advisory Circular 91-36C prohibits the use of fixed-wing aircraft lower than an elevation of 152 m
                  and helicopters lower than 300 m during the period of October 15 through April 15 in the vicinity of numerous
                  national wildlife refuges in the Gulf of Mexico to prevent disturbances to the birds (Biological Opinion - Section
                  7 Consultation, Proposed Exploration Plans for OCS in the Gulf of Mexico; FWS/OES 375.0). The majority
                  of these wildlife refuges provide important critical habitats (feeding, resting, or nesting areas) for endangered
                  and threatened species. Although interactions may occur and be disruptive, effects are expected to be sublethal
                  and, at worst, of a temporary nature. It is expected that helicopter traffic near critical feeding, resting, or










                                                                                                                             IV-327

                nesting areas will rarely disturb the brown pelican, Arctic peregrine falcon, bald eagle, or piping plover because
                of special prohibitions and adherence to the general, FAA minimum ceiling of 300 m.
                    It is assumed, that during the peak year, 36,000 OCS-related oil and gas service-vessel trips, 2 shuttle tanker
                trips, and 299 barge traffic trips will occur as a result of the proposed action, plus prior and future OCS sales
                in the CPA (Table IV-7). Most of the OCS-related oil and gas traffic occurs in and out of areas that are well
                away from critical habitats for feeding, resting, or breeding areas of the Arctic peregrine falcon, bald eagle, or
                piping plover. Some OCS-related service vessel traffic occurs in the vicinity of Cameron, Intracoastal City,
                Morgan City, and Venice, Louisiana, within several miles of critical habitats (feeding, resting, or breeding areas)
                for the brown pelican. Although incidents may occur and be disruptive, effects are expected to be sublethal
                and, at worst of a temporary nature. It is expected that service-vessel traffic will seldom disturb the brown
                pelican.
                    Disturbance of brown pelican and piping plover critical feeding, resting, or breeding habitats from pipeline
                landfalls and onshore construction could result in a reduction or desertion of birds that use the habitats. It is
                assumed that three new OCS oil- and gas-related pipeline landfalls and three new coastal facilities will be
                constructed as a result of the proposed action, plus prior and future OCS sales (Table IV-12). Sublethal
                effects are expected from these activities. It is expected that pipeline landfalls and onshore construction will
                infrequently interact with critical feeding, resting, or breeding habitats of the brown pelican, Arctic peregrine
                falcon, or piping plover.
                    The brown pelican, Arctic peregrine falcon, bald eagle, and piping plover can become entangled in or
                ingest trash and debris. Interaction with plastic materials can be especially injurious. The MMS prohibits the
                disposal of equipment, containers, and other materials into offshore waters by lessees (30 CFR 250.40). In
                addition, MARPOL, Annex V, Public Law 100-220 (101 Statute 1458), which prohibits the disposal of any
                plastics at sea or in coastal waters, went into effect January 1, 1989. It is assumed that little trash and debris
                will be lost into the Gulf of Mexico as a result of the proposed action, plus prior and future OCS sales.
                However, it is expected that some trash and debris will be lost or discarded into the Gulf from non-OCS
                commercial and recreational endeavors, which are not as highly regulated. Although interactions may occur,
                effects are expected to be sublethal. It is expected that the brown pelican, Arctic peregrine falcon, bald eagle,
                and piping plover will periodically become entangled in or ingest trash and debris.
                    When an oil spill occurs, many factors interact to delimit the severity of effects and extent of damage to
                threatened and endangered birds. Determining factors include geographic location, oil type, off dosage, impact
                area, oceanographic conditions, meteorological conditions, and season (NRC, 1985; USDOI, MMS, 1987b).
                The direct effect of oiling on birds occurs through the matting of feathers and subsequent loss of insulation and
                water-repellency, the ingestion of oil, the depression of egg-laying activity, and the reduction of hatching success
                (Holmes and Cronshaw, 1977; Ainley et al., 1981; Peakall et al., 1981). Transfer of oil from adults to eggs and
                young during nesting results in significant mortality for new eggs and deformities in hatchlings from eggs further
                along in incubation (Clapp et al., 1982a). Indirect effects of oil spills include contamination, displacement, and
                reduction of food sources. Food contamination may cause less severe, sublethal effects decreasing survival and
                fecundity, affecting behavior, and decreasing survival of young. Less severe, sublethal effects are defined as
                those that impair the ability of an organism to function effectively without causing direct mortality (NRC, 1985).
                In the event that offing of the brown pelican, Arctic peregrine falcon, bald eagle, or piping plover should occur
                from oil spills less than 1,000 bbl, the effects would primarily be sublethal; few mortalities are expected. The
                effects of oil spills less than 1,000 bbl are expected to be solely sublethal due to the small area affected. In
                the event that oil spills of any size should occur in critical habitats for feeding, resting, or breeding, such as
                inshore, intertidal, and nearshore areas, sublethal effects are expected. It is expected that the extent and
                severity of effects from off spills of any size will be lessened by improved coastal oil spill contingency planning
                and response, deterrence of birds away from the immediate area of an oil spill, and increased percentage of
                survival from rehabilitation efforts (Section IV.C.6.).
                     Section IV.C.3. estimates the mean number of offshore spills less than 1,000 bbl occurring as a result of
                the proposed action, plus prior and future OCS sales in the CPA. It is assumed that 24 spills greater than 1
                and less than or equal to 50 bbl will occur each year, and that a few offshore spills will contact coastal areas.
                It is assumed that I offshore spill per year and I onshore spill every 5 years greater than 50 and less than 1,000
                bbl will occur. None of the offshore spills will contact coastal areas. Although an interaction with spills less










                 IV-328

                 than 1,000 bbl is estimated, only sublethal effects are expected. It is estimated that spills less than 1,000 bbl
                 will periodically contact and affect the brown pelican, Arctic peregrine falcon, bald eagle, and piping plover.
                      It is assumed that 44 crude oil spills greater than or equal to 1,000 bbl will occur as a result of import
                 tankering and the proposed action, plus prior and future OCS sales in the Gulf of Mexico (Table IV-19).
                 Section IV.C.3. identifies the estimated risk of one or more oil spills greater than or equal to 1,000 bbl
                 occurring and contacting within 10 days critical habitats for feeding, resting, or breeding of the brown pelican,
                 Arctic peregrine falcon, bald eagle, and piping plover in the CPA. The highest probability of one or more oil
                 spills greater than or equal to 1,000 bbI occurring and contacting within 10 days a coastal bay in the Central
                 Gulf is 32 percent (Timbalier Bay). The highest estimated probability of one or more spills greater than or
                 equal to 1,000 bbl occurring and contacting within 10 days deltaic marshes is 49 percent. Although an
                 interaction with spills greater than or equal to 1,000 bbl is expected, primarily sublethal effects are expected
                 with infrequent mortalities. It is assumed that an oil spill greater than or equal to 1,000 bbl will periodically
                 contact and affect the brown pelican, Arctic peregrine falcon, bald eagle, and piping plover in the CPA.
                      Some critical feeding habitats of the brown pelican, Arctic peregrine falcon, and piping plover occur
                 nearshore. The highest estimated probability of one or more spills greater than or equal to 1,000 bbl occurring
                 and contacting within 10 days nearshore areas (coastline) along the Central Gulf is 85 percent Sublethal
                 effects from the spills assumed to occur are expected. It is expected that an oil spill greater than or equal to
                 1,000 bbI will periodically contact and affect nearshore areas (coastline) critical to the feeding of the brown
                 pelican, Arctic peregrine falcon, and piping plover.

                 Summa?y

                      The brown pelican, Arctic peregrine falcon, bald eagle, and piping plover may be impacted by helicopter
                 and service-vessel traffic, onshore pipeline landfalls, entanglement in and ingestion of offshore oil- and gas-
                 related plastic debris, and oil spills. The effects of these activities are expected to be sublethal. Lethal effects
                 are expected only from oft spills greater than or equal to 1,000 bbl. Oil spills of any size are expected to be
                 infrequent events that will periodically contact threatened and endangered birds or their critical feeding, resting,
                 or breeding habitats.
                      The incremental contribution of the proposed action (as analyzed in Section IV.D.La.(7)(b)) to the
                 cumulative impact is inconsequential because the effects of sale-specific helicopter and service-vessel traffic,
                 trash and debris, and onshore pipeline landfalls are expected to be sublethal. Lethal effects are expected only
                 from oil spills greater than or equal to 1,000 bbI that are judged to be extraordinary events that will
                 infrequently contact endangered and threatened coastal and marine birds.

                 Conclusion

                      The impact of the Cumulative Case scenario on endangered and threatened birds withl[n the potentially
                 affected area is expected to result in a decline in species numbers or a temporary displacement from their
                 current distribution, a decline or displacement that will last more than one generation.
                 (8) Impacts on the GuySturgeon

                      This Cumulative Analysis considers the effects of impact-producing factors related to the Central Gulf
                 proposed action, prior and future OCS sales, State oil and gas activity, alteration and destruction of habitat,
                 natural catastrophes, and commercial fishing on the Gulf sturgeon. The Gulf sturgeon ranges in nearshore,
                 inshore, and freshwater from the Atchafalaya River in central Louisiana to the Suwannee River in the Florida
                 panhandle. Gulf sturgeon are thought to spawn in rivers from the Pearl River area in western Mississippi to
                 the Suwannee River in the Florida panhandle.
                      The effects from the major impact-producing factors are discussed in detail in Section IWD.La.(8) and are
                 described below. Sections providing supportive material for the Gulf sturgeon analysis include III.B.6.(b)
                 (description of Gulf sturgeon), IV.B.4. (other major coastal/onshore activities), and IV.C.3. (oil spills).










                                                                                                                               IV-329

                      The direct effects of spilled off on Gulf sturgeon occur through the ingestion of oil or oiled prey, the uptake
                 of dissolved petroleum products through the gills and epithelium by adults and juveniles, and through mortality
                 of eggs and decreased survival of larvae. In the event that oiling of Gulf sturgeon adults should occur from
                 oil spills greater than or equal to 1,000 bbl, the effects would primarily be sublethal-, few mortalities are
                 expected. The effects of oil spills less than 1,000 bbl are expected to be solely sublethal due to the small area
                 affected and their rapid dispersion. It is expected that the extent and severity of effects from off spills of any
                 size will be lessened by improved coastal oil spill contingency planning (Section IV.C.5.) and by active
                 avoidance of oil spills by adult sturgeon.
                      Section IV.C.3. estimates the mean number of spills less than 1,000 bbl occurring as a result of the
                 proposed action, plus prior and future OCS sales in the CPA. It is assumed that 24 offshore spills and 1
                 onshore spill greater than 1 and less than or equal to 50 bbl will occur each year. Of these spills, it is assumed
                 that a few offshore spills will contact coastal areas. It is assumed that 1 offshore spill per year and I onshore
                 spill every 5 years greater than 50 and less than 1,000 bbl will occur each year. None of the offshore spins will
                 contact the coast. Although an interaction with spills less than 50 bbl is expected, only sublethal effects are
                 expected. It is expected that spills less than 1,000 bbl will infrequently contact or affect Gulf sturgeon.
                      It is assumed that 44 crude oil spills greater than or equal to 1,000 bbl win occur as a result of import
                 tankering and the proposed action, plus prior and future OCS sales in the Gulf of Mexico (Table IV-19).
                 Section IV.C.3. identifies the estimated risk of one or more oil spills greater than or equal to 1,000 bbl
                 occurring and contacting within 10 days coastal areas near Gulf sturgeon. The highest estimated probability
                 of one or more spills greater than or equal to 1,000 bbl occurring and contacting within 10 days nearshore areas
                 (coastline) along the Central Gulf is 85 percent. There is a 9 percent probability of one or more oil spin
                 greater than or equal to 1,000 bbl occurring and contacting within 10 days the coastal areas of Gulf sturgeon
                 (St. Mary Parish, Louisiana; Hancock County, Mississippi; Mobile and Baldwin Counties, Alabama; and
                 Escambia County, Florida). Although an interaction with spills greater than or equal to 1,000 bbl is expected,
                 primarily sublethal effects are expected with infrequent mortalities. It is expected that oil spins greater than
                 or equal to 1,000 bbl will seldom contact or affect Gulf sturgeon or their habitats.
                      Non-OCS operations such as dredge-and-fiff activities and natural catastrophes can cause the loss of Gulf
                 sturgeon habitats, e.g., nearshore wetland areas. Non-OCS activities such as commercial fishing directly impact
                 Gulf sturgeon.
                      Dredge-and-fill activities occur throughout the nearshore areas of the United States. They range in scope
                 from propeller dredging by recreational boats to large-scale navigation dredging and fill for land reclamation.
                 Natural catastrophes, including storms, floods, droughts, and hurricanes, can result in substantial damage to
                 Gulf sturgeon habitats. Sublethal effects on Gulf sturgeon are expected from these activities. It is expected
                 that dredge-and-fiff activities and natural catastrophes will periodically contact and affect Gulf sturgeon habitats.
                      Fishing techniques such as trawling, gill netting, or purse seining, when practiced nonselectively, may reduce
                 the standing stocks of the desired target species as well as significantly impact species other than the target.
                 It is estimated that for every 0.5 kg of shrimp harvested, 4 kg of bycatch, which includes a number of Gulf
                 sturgeon, is discarded (Sports Fishing Institute, 1989). Lethal and sublethal effects are expected from
                 commercial fishing. It is expected that commercial fishing will periodically contact and affect Gulf sturgeon.

                 Summary

                      Activities resulting from the Cumulative scenario have a potential to cause detrimental effects on the Gulf
                 sturgeon. Those activities include oil spills, alteration and destruction of habitat, natural catastrophes, and
                 commercial fishing. The effects of the majority of these activities are expected to be sublethal. Lethal effects
                 are expected from oil spills greater than or equal to 1,000 bbl and from commercial fishing. Oil spills of any
                 size as a result of import tankering, the proposed action, and prior and future lease sales are expected to be
                 infrequent events that will occasionally contact Gulf sturgeon or their habitats. It is expected that the Gulf
                 sturgeon will experience a decline in species numbers or a temporary displacement from their current
                 distribution, a decline or displacement that will last more than one generation.
                      The incremental contribution of the proposed action (as analyzed in Section IV.D.La.(8)) to the cumulative
                 impacts is small because the effects of sale-specific oil spills less than 1,000 bbl are expected to be sublethal.










                 IV-330

                 It is expected that there will be no interaction between sale-related oil spills greater than or equal to 1,000 bbi
                 and oil-spill response activities and the Gulf sturgeon.

                 Conclusion


                     The impact of the Cumulative Case scenario on the Gulf sturgeon within the potentiaD@ affected area is
                 expected to result in a decline in species numbers or a temporary displacement from their current distribution,
                 a decline or displacement that will last more than one generation.

                 (9) Impacts on Commercial Fisheties

                     This Cumulative Analysis considers the status of commercial fishery stocks, the effects of impact-producing
                 factors related to the Central Gulf proposed action, prior and future OCS sales, State oil and gas activity, crude
                 oil imports by tanker, and offshore recreational fishing that may occur and adversely affect the commercial
                 fishing industry in the same general area that may be affected by OCS oil and gas activity located in the CPA-
                 Specific Pipes of impact-producing factors considered in the analysis include commercial fishing techniques or
                 practices, loss of wetlands, structure removal, construction of offshore oil and gas platforms, and
                 OCS-produced-water discharge.
                     Sections providing supportive material for the commercial fisheries analysis include Sections III.B.6.
                 (description of fish resources), III.C.3. (commercial fishing stocks and activities), IV.A.2.d.(.3) (use conflicts),
                 IV.A.2.b.(I) (pipelines), IV.A.2.a.(3) (structure removal), IV.A.2.a.(l) (seismic operations), I'V.C.3. (oil spills),
                 IV.A-2.d.(8) (subsurface blowouts), and IV.A_2.d.(5) (offshore discharges).
                     Competition between large numbers of commercial fishermen, between commercial operations employing
                 different fishing methods, and between commercial and recreational fishermen for a given fishery resource, as
                 well as natural phenomena such as weather, hypoxia, and red tides, may reduce standing populations. Fishing
                 techniques such as trawling, gill netting, or purse seining, when practiced nonselectively, may reduce the
                 standing stocks of the desired target species as well as significantly impact species other than the target
                 Space-use conflicts can result from different forms of commercial operations and between commercial and
                 recreational fisheries. Finally, hurricanes may impact commercial fisheries by destroying oyster reefs, damaging
                 gear and shore facilities, and changing physical characteristics of inshore and offshore ecosystems. The
                 availability and price of key supplies and services, such as fuel, can also affect commercial fishing operations
                 in the Gulf of Mexico.
                     The majority of commercial species harvested from the Gulf of Mexico are believed to be in serious decline
                 from overfishing. Continued fishing at the present levels may result in rapid declines in cornmercial landings
                 and eventual failure of certain fisheries. Commercial landings of traditional fisheries, such as shrimp and red
                 snapper, have declined over the past decade despite increases in fishing effort. Commercial Lindings of recent
                 fisheries, such as shark, black drum, and tuna, have increased exponentially over the past five years, and those
                 fisheries are thought to be in danger of collapse (Angelovic, written comm., 1989; USDOC, NMFS, 1991a).
                 It is expected that overfishing of targeted species and trawl fishery bycatch will adversely affect commercial
                 fishery resources. The severity of the effects of overfishing on the commercial fishing resources could be
                 prominent, involving a decline in populations of commercial importance that will recover to their former level
                 within two to three generation.
                     Because approximately 92 percent of commercially important species are estuarine dependent, the
                 degradation of inshore water quality and the loss of Gulf wetlands as nursery areas are considered significant
                 threats to the commercial fishing industry (Angelovic, written comm., 1989; Christmas et aL, 1988; USEPA,
                 1989). Loss of wetland nursery areas in the CPA is believed to be the result of channelization, river control,
                 and subsidence of wetlands (Turner and Cahoon, 1987). It is expected that wetlands loss and water quality
                 degradation will adversely affect commercial fishery resources. The severity of the effects of wetlands loss and
                 water quality degradation on commercial fishing resources could be considerable, involving a decline in a
                 population of commercial importance, in the quality of essential habitats, or in commercial fishing activity that
                 will recover to its former level and/or condition in two to three generations.











                                                                                                                             IV-331

                      Those species of commercial importance that are not estuary dependent, such as mackerel, cobia, and
                 crevalle, are considered coastal pelagics. Populations of these species exhibit some degree of coastal
                 movement. These species range throughout the Gulf, move seasonally, and are more abundant in the CPA
                 during the summer (Gulf of Mexico Fishery Management Council, 1985). In general, the coastal movements
                 of these species are restricted to one or two planning areas within the Gulf of Mexico Region and are not truly
                 migratory, as is the case with salmon. The coastal movements of these species are related to reproductive
                 activity, seasonal changes in water temperature, or other oceanographic conditions. Discernible effects to
                 regional populations or subpopulations; of these species as a result of OCS oil and gas activities are not
                 expected, because pelagic species are distributed and spawn over a large geographic area and depth range.
                      Structure removals result in artificial habitat loss and cause fish kills when explosives are used. Table IV-7
                 assumes that 1,887 structure removals by explosives will occur in the CPA under the Cumulative scenario
                 during the 35-year life of the proposed action. It is assumed that no more than 94 removals will occur in the
                 CPA during this time in any single year. For the purpose of this analysis, it is estimated that structure removals
                 will have a major effect on Central Gulf fisheries near the removal sites because removals will be routine
                 events. However, only those fish proximate to the removal sites will be killed.
                      The 340 additional platform complexes resulting from the proposed action, plus prior and future OCS sales
                 in the CPA (Table IV-7), are estimated to reduce trawling area by about 15,126 ha (37,361 ac) during the peak
                 year. This represents an inconsequential amount of the total trawling area in the CPA. It is expected that
                 platform emplacement will infrequently affect trawling activity.
                      Oil spills that contact coastal bays, estuaries, and waters of the OCS during the time when high
                 concentrations of pelagic eggs and larvae are present have the greatest potential to damage commercial fishery
                 resources.
                      Section IV.C.3. estimates the mean number of offshore spills less than 1,000 bbl occurring in the CPA-
                 It is assumed that 24 spills greater than 1 and less than or equal to 50 bbl will occur offshore each year. A few
                 offshore spills will contact coastal areas. It is assumed that I spill greater than 50 and less than 1,000 bbl will
                 occur each year. However, none of these spills is assumed to contact the coastline or inshore areas during the
                 35-year life of the proposed action. It is expected that oil spills less than 1,000 bbl will occasionally affect
                 coastal bays and marshes essential to the well-being of the commercial fishery resources in the CPA-
                      Section IV.C.3. estimates the mean number of spills greater than or equal to 1,000 bbl occurring from
                 cumulative activity in the CPA. It is assumed that 7 crude oil spills greater than or equal to 1,000 bbl from
                 platforms and pipelines and 37 spills from tankers will occur in the Gulf of Mexico over the 35-year life of the
                 proposed action. Section IV.C.3. identifies the estimated risk of one or more oil spills greater than or equal
                 to 1,000 bbl resulting from cumulative activity (the proposed action, prior and future OCS leasing, import
                 tankering, and OCS shuttle tankering) occurring and contacting, within 10 days, coastal bays and marshes
                 essential to the well-being of commercial fishery resources in the CPA.
                      The estimated mean number of spills greater than or equal to 1,000 bbl to occur and contact nearshore
                 areas (coastline) in the Cumulative Case in the Gulf is two. The estimated mean number of spills greater than
                 or equal to 1,000 bbl to occur and contact within 10 days deltaic marshes is 1 (Table IV-21). Plaquemines
                 Parish, Louisiana, is the land segment with the highest probability (54% from OCS activities and 21% from
                 imports) of occurrence and contact within 10 days by one or more spills greater than or equal to 1,000 bbl.
                 Barataria Bay is the coastal inshore bay with the highest probability (36% from OCS activities) of occurrence
                 and contact within 10 days by one or more spills greater than or equal to 1,000 bbl. The estimated probability
                 of one or more spills greater than or equal to 1,000 bbl occurring and contacting within 10 days deltaic marshes
                 is 49 percent from platforms, pipelines, and shuttle tankers.
                      Oil spills greater than or equal to 1,000 bbI originating in port from the tankering of imported oil include
                 those that may occur and contact bays and estuaries. The highest estimated probability of one or more oil
                 spills greater than or equal to 1,000 bbl originating from tankering of imported oil occurring and contacting
                 within 10 days a Central Gulf bay or estuary is 93 percent (Mississippi River ports). The estimated mean
                 number of spills greater than or equal to 1,000 bbl originating from tankering of imported oil occurring and
                 contacting within 10 days a Central Gulf bay or estuary is two. The highest estimated probability of one or
                 more oil spills greater than or equal to 1,000 bbl originating from tankering of imported oil occurring and
                 contacting within 10 days OCS waters in the CPA is 97 percent (Louisiana Offshore Oil Port [LOOPJ). The










                  IV-332

                  estimated mean number of spills greater than or equal to 1,000 bbl originating from tankerhig of imported oil
                  and occurring and contacting within 10 days OCS waters in the CPA from LOOP is 3 (Table IV-21).
                      It is expected that, as a result of cumulative activity, the interaction of oil spills greater than or equal to
                  1,000 bbl, either assumed to occur and contact or assumed to occur, with commercial fishery resources in the
                  Central Gulf will have a considerable effect on the commercial fishing industry. It is expected that oil spills
                  will regularly contact and affect Central Gulf coastal bays, estuaries, or coastal areas. As a singular example,
                  the highest estimated probability of one or more oil spills greater than or equal to 1,000 Ibbl occurring and
                  contacting within 10 days Gulf menhaden during their winter spawning in coastal waters Of the CPA is 26
                  percent over the next 35 years. Therefore, this analysis expects noticeable interaction of commercial fishery
                  resources with off spills.

                  Summary

                      Habitat loss results in the decline of commercial populations, essential habitats, and o:)mmercial fishing
                  activity. In the Central Gulf coastal zone, habitat loss occurs from channelization, river control, and subsidence
                  of wetlands.
                      Overfishing results in rapid declines in commercial populations and landings and in the eventual failure
                  and loss of both traditional and recent fisheries. The majority of commercial species harvested from the Gulf
                  of Mexico is believed at present to be in a seriously depleted condition due to overfishing.
                      The emplacement of one production platform eliminates approximately 6 ha (15 ac) of commercial trawling
                  space. The 340 additional offshore platform complexes will remove 15,126 ha (37,361 ac) from commercial
                  trawling.
                      Structure removals result in fish kills in the vicinity of the removals, which represents an inconsequential
                  amount of the total trawling area.
                      Oil spills pose the greatest threat to the commercial fishing industry by direct contact with eggs, larvae,
                  juveniles, or massed spawning adult finfish or shellfish; by contamination of essential estuarine nursery habitat;
                  or by deterrence of commercial fishing activity. It is assumed that 44 oil spills greater than or equal to 1,000
                  bbl will occur during the 35-year life of the proposed action. The highest estimated probability of contact and
                  affect, contamination, or deterrence involving commercial fishing resources is 97 percent.
                      The incremental contribution of the proposed action (as analyzed in Section IV.D.La.(9)) to the cumulative
                  impact is inconsequentialbecause the effects of sale-specific underwater O-CS obstructions, subsurface blowouts,
                  operational discharges, explosive structure removal, space-use conflict, and seismic surveys are expected to be
                  negligible. Substantial effects are expected only from oil spills greater than or equal to 1,000 bbl that will
                  seldom contact areas essential to commercial fisheries.


                  Conclusion


                      The cumulative effect on the commercial fishing industry within the potentially affected area is expected
                  to result in a discernible decline in populations of commercial importance, in the quality of essential habitats,
                  or in commercial fishing activity. Recruitment will return any affected population, habitat, or activity to pre-
                  impact level and/or condition within two to three generations.

                  (10) Impacts on Recreational Resources and Activities

                  (a) Beach Use

                      This Cumulative Analysis considers the effects of impact-producing factors related to the proposed action
                  (Section IV.D.La.(10)(a)), plus those related to prior and future OCS sales, State offshore oil and gas'activity,
                  tankering of crude oil imports, merchant shipping, commercial and recreational fishing, defense operations,
                  recreational use of beaches, and other offshore and coastal activity that results in debris, litter, trash, and
                  pollution, which may occur and adversely affect major recreational beaches. Specific impact- producing factors










                                                                                                                             IV-333

                analyzed include oil spills, trash and debris, and platforms and drilling rigs. Other factors such as land
                development, civil works projects, and natural phenomena have affected, and will continue to affect, beach
                stabilization (Section IV.D.La.(1)(a)); ultimately, these factors may also affect the recreational use of beaches.
                    One or two 10-day-old oil spills of 1,000 bbI or greater (Table IV-21), and a few spills each year of the size
                class greater than I and less than or equal to 50 bbl are assumed to occur and contact land as a result of
                Federal OCS activity and crude-oil import tankering (Section IV.C.4.). Such spill contacts will occur between
                1993 and 2027 and, according to the OSRA model (Table IV-21), are most likely to affect major recreational
                beaches in Texas (Galveston/Bolivar Peninsula) and Louisiana (Cameron beaches). Spills greater than or equal
                to 1,000 bbl (Section IV.C.1) are expected to result in short-term disturbances, causing temporary loss or
                displacement of water-related, nearshore recreational activity on specific beaches directly or indirectly impacted.
                Furthermore, over the next 35 years 16 spills 1,000 bbl or greater (Table IV-19) involving tankers carrying
                imported petroleum liquids could adversely impact beaches in the vicinity of major inshore Gulf of Mexico
                ports from Mobile to Corpus Christi. It is important to realize, especially in the cumulative impact context,
                that of all chronic hydrocarbon pollution existing in the Gulf, less than 1 percent is directly related to Gulf of
                Mexico oil and gas leasing and production (Section IV.C.4.). In terms of effects, chronic natural and human-
                induced hydrocarbon pollution can manifest itself on beaches as tarballs, which would adversely impact beach
                users, recreational developments, and personal property. Current tar ball occurrence on the CPA recreational
                beaches is believed to be derived from sources other than leasing and production in the Gulf of Mexico.
                    Continued and expanded oil and gas operations in the CPA have contributed to the already serious
                problem of debris and trash on coastal beaches. Trash and debris detract from the aesthetic quality of beaches,
                can be hazardous to beach recreational activity, and can increase the cost of beach maintenance programs.
                Other factors such as merchant shipping, naval operations, offshore commercial and recreational fishing, natural
                phenomena, recreational use of beaches, State oil and gas activity, tankering, pipelines, operational discharges,
                condominiums, coastal activity in Mexico and Cuba, and other offshore and coastal activities contribute to
                flotsam, jetsam, pollution, and litter existing on the major Gulf of Mexico recreational beaches. Trash and
                debris are a recognized problem affecting enjoyment and maintenance of recreational beaches in the CPA- It
                has been estimated that OCS oil and gas operations are contributing 10-12 percent of the trash and debris
                affecting Texas and Louisiana recreational beaches (USEPA, 1990; Parker, personal comm., 1990).
                    Reports by Lindstedt and Holmes (1988) and the Center for Marine Conservation (1989) indicate Gulf
                of Mexico beaches from Texas to Mississippi are among the country's most littered shorelines. The reports
                provide insight into the magnitude and composition of the cumulative trash loads affecting CPA coastal
                beaches. Items known to be associated with the oil and gas industry have been frequently identified with the
                beach litter removed from Louisiana and Texas beaches; however, the percentage of the litter attributed to the
                petroleum industry has noticeably declined in the past few years (Amos, 1991). Regulatory, administrative, and
                volunteer programs involvinggovernment; industry-, environmental, school, and civic groups; and private citizens
                are monitoring and reducing the gravity of the beach litter problem Gulfwide.
                    There are currently 3,422 platforms on the OCS in the CPA (Table IV-7), and an additional 340 will likely
                be added from previous sales, this proposal, and future sales over the next 35 years. A total of 169 of these
                platform complexes are projected for coastal Subareas C-1 and C-3. Those platforms and predevelopment
                drilling rigs operating in the first three tiers of Federal lease tracts within 3-10 mi of recreational beaches will
                be visible to beach users during good weather conditions. Vessel and helicopter traffic servicing these
                operations and those farther offshore will from time to time be seen and heard by beach users. Existing and
                future oil and gas developments in State waters can exacerbate these aesthetic impacts or render them less
                onerous. Aesthetic impacts are unlikely to affect the level of beach recreational use in the Gulf Region, but
                may affect the sensibilities of some beach users, especially those enjoying beach wilderness areas such as Gulf
                Island National Wilderness Area.


                Summary

                    For purposes of this analysis, one or two oil spills 1,000 bbl or greater estimated to preclude short-term
                recreational use of some Louisiana or Texas beaches at the park or community levels are expected in the next
                35 years. However, smaller annual spills throughout the planning area are estimated to preclude short-term
                use of the small segments of recreational beaches adversely impacted, but will have little effect on local










                 IV-334

                 recreational use or tourism. Frequent impacts from man-induced debris and litter derived from both offshore
                 and onshore sources are likely to diminish the tourist potential of CPA beaches and to degrade the ambience
                 of shoreline recreational beaches chronically, thereby affecting the enjoyment of recreational beaches
                 throughout the planning area. Platforms and drilling rigs operating nearshore and seaward of coastal beaches
                 may affect the ambience of beach use, especially near beach wilderness areas. However, pollution and debris
                 associated with the proposed sale will contribute minimally to this impact.
                     A ton or more per mile of trash and debris has been removed from recreational beaches cleaned in the
                 CPA each fall since 1988. The incremental contribution of the proposed action (as analyzed in Section
                 IV.D.La.(10)(a)) to the cumulative impact is expected to be minimal because sale-specific: operational activities
                 are unlikely to cause significant beach closures or to generate the need for excessive beach maintenance. Oil
                 pollution events impacting recreational beaches will generate immediate cleanup response from lease site
                 operators, and the oil and gas industry has improved offshore waste management practices and made a strong
                 commitment to participate in the removal of trash and Utter from recreational beaches throughout the CPA.
                 Furthermore, MARPOL Annex V and the special efforts to generate cooperation and sup@ ort for reducing
                 marine debris through the Gulf of Mexico Program's Marine Debris Action Plan should lead to a decline in
                 the level of human-generated trash adversely affecting recreational beaches throughout the Gulf.

                 Conclusion


                     Although trash and accidental oil spills will continue to affect the ambience of recreational beaches
                 between Alabama and Texas, the level of chronic pollution should decline during the life of the proposed
                 action. Beach use at the regional level is unlikely to change; however, closure of specific beaches or parks
                 directly impacted by one or two oil spills greater than or equal to 1,000 bbl is likely during cleanup operations.
                 (b) Marine Fishing

                     This Cumulative Analysis considers the effects of impact-producing factors related to the proposed action
                 (Section IV.D.La.(10)(b)), plus those related to prior and future OCS sales; State offshore oil and gas activity,
                 tankering of crude oil imports; other marine vessel traffic and port congestion; and other commercial, military,
                 and recreational offshore activities that might affect offshore marine recreational fishing.
                     Activity related to OCS oil and gas development is projected to add 340 offshore platforms in the CPA
                 over the next 35 years (Table IV-7). Of these, 169 new platform complexes are projected for the coastal
                 Subareas C-I and C-3. These new platforms will be the most accessible and the most likely to affect offshore
                 fishing, because they function as high profile, de facto artificial reefs. These structures would add to the
                 existing 3,422 petroleum structures on the OCS in the CPA and several permitted artificial reefs also in the
                 planning area. Structure removals are expected to outpace installations in the next 5-10 years (Table IV-7).
                 Studies and observations have shown that, where oil and gas structures are accessible, they are significant
                 attractants of offshore fishermen, and they enhance fishing success. Conversely, anthropogenic pollution and
                 activity (oil and chemical spills, competition between commercial and recreational fishermen and among
                 recreational fishermen, coastal modifications brought on by industrial development and population increases
                 in the coastal zone) and inevitable natural forces, such as subsidence, erosion, anoxia, floods, and freezes, will
                 affect short- and long-term sociological and ecological changes that will indirectly stress lishery resources
                 important to marine recreational fishing and could lead to the increase of restrictive regulations affecting fishing
                 enjoyment and participation. Should there be a sustained, declining trend in offshore 1-ishing trips, the
                 recreational fishing support industry is likely to suffer as wen.
                     The 7 offshore oil spills 1,000 bbl or greater (Table IV-19) from platforms, pipelines, and tankers and 10
                 inshore tanker spills from Mobile to Port Arthur (Table IV-16), estimated to occur over the next 35 years will
                 cause temporary disinterest in recreational fishing within the area of visible oil slicks, but should not affect the
                 level of recreational fishing within the planning area.
                     Offshore oil and gas activity has had a very high level of impact on recreational fishing in the CPA, and
                 continued oil and gas development as a result of continued Federal and State offshore lease sales is expected











                                                                                                                            IV-335

                to assist in maintaining recreational fishing levels in CPA offshore areas over the next 35 years. Because of
                the expected increase in the structure removal rate (currently around 80 per year) and greater interest in
                artificial reef development Gulfwide, more interest in the use of obsolete oil and gas structures as dedicated
                reefs in the marine environment is likely. The National Fishing Enhancement Act of 1934 and management
                measures adopted by NMFS through the planning efforts of the Gulf of Mexico Fishery Management Council
                will also affect the future of offshore fishing in the CPA.

                Summary

                     The incremental contribution of the proposed action (as analyzed in Section IV.D.La.(10)(b)) to the
                cumulative impacts is very low because sale-specific activity will generate only 30 new production platforms in
                the CPA. This represents only I percent of the platforms existing in the CPA. Should any of these platforms
                be placed within 25 mi of shore near major coastal fishing access areas, they will likely attract some fishermen
                and divers, but normal offshore fishing patterns strongly associated with existing offshore off and gas structures
                are unlikely to change until most old structures have been removed and replaced with permitted artificial reefs.

                Conclusion


                     Continued offshore oil and gas development over the next 35 years will continue to support, maintain, and
                facilitate offshore recreational fishing in the CPA and extend the time offshore oil and gas structures are a
                focus of offshore fishing activity.

                (11) Impacts on Archaeological Resources

                     The following analysis considers not only the effects of the impact-producing factors related to the
                proposed action, but OCS activities in the Western Gulf, as well as prior and ftiture OCS sales. Specific types
                of impact-pToducing factors considered in this analysis include drilling rig and platform emplacement, pipeline
                emplacement, anchoring, oil spills, dredging, new onshore facilities, and ferromagnetic debris associated with
                OCS hydrocarbon activities. Included also in this analysis are trawling, sport diving, commercial treasure
                hunting, and tropical storms.
                     Continued OCS off and gas activities will contribute to the cumulative impacts on historic and prehistoric
                archaeological resources. Some 46,816 exploration and production wells, 4,282 platform installations, and
                39,594 kin of pipelines are estimated to occur or to have occurred throughout the entire Gulf of Mexico from
                the proposed action and prior and future OCS sales (Tables IV-7 and IV-8). Bottom disturbance associated
                with these impact-producing factors will have the potential to impact archaeological sites. Beginning in 1974,
                archaeological surveys were required prior to development on the OCS. It is assumed in this analysis that the
                majority of impacts to archaeological resources occurred in association with development prior to 1974.
                     The placement of drilling rigs and production platforms has the physical potential to impact prehistoric
                and/or historic archaeological resources. It is assumed that the standard rig will directly disturb 1.5 ha of soft
                bottom, the average platform 2 ha. Pile driving associated with platform emplacement may also cause sediment
                liquefaction an unknown distance from the piling. This liquefaction could result in disturbance of stratigraphy
                in the area of liquefaction.
                     Pipeline placement has the physical potential to impact prehistoric and/or historic archaeological resources.
                Those pipelines placed in water depths of less than 61 in (200 ft) must be buried. Burial depths of I in (3 ft)
                are required with the exception of shipping fairways and anchorage areas, where the burial depths are 10 ft
                and 15 ft, respectively.
                     The dredging of new channels as well as maintenance dredging of existing channels has the physical
                potential to impact historic shipwrecks (Espey, Huston, & Associates, 1990) and prehistoric sites. At present,
                there are 23 navigation channels that provide OCS access to onshore facilities.










                 IV-336

                      Anchoring associated with platform and pipeline emplacement, as well as service vessel and shuttle tanker
                 activities, may also physically impact prehistoric and/or historic archaeological resources. It is assumed that
                 during pipeline emplacement, an array of eight 20,000-lb anchors is continuously repositioned.
                      Oil spills have the potential to impact both prehistoric and historic archaeological resources. Impacts to
                 historic resources would be limited to visual impacts and, possibly, physical impacts associated with spill cleanup
                 operations. Impacts to prehistoric archaeological sites would be the result of hydrocarbon contamination of
                 organic materials, which have the potential to date site occupation through radiocarbon dating techniques, as
                 well as possible physical disturbance associated with spin cleanup operations.
                      New onshore facilities have the potential to impact historic and prehistoric sites both directly and indirectly.
                 Direct physical impacts to archaeological sites could occur from construction activity. Indirect impacts could
                 occur by the "capping" of historic sites by pouring concrete slabs or placing structures on top of archaeological
                 sites.
                      The OCS oil and gas activities will also generate tons of ferromagnetic structures and debris, which win
                 tend to mask magnetic signatures of significant historic archaeological resources. The task oflocating historic
                 resources through an archaeological survey is, therefore, made more difficult as a result of leasing activity.
                      Trawling has the potential to disturb the uppermost portion of the sediment column (Garrison et al., 1989).
                 There is the potential that transient features associated with archaeological sites (i.e., fight, easily transported
                 artifacts) could be disturbed by commercial fishing activity.
                      Sport diving and commercial treasure hunting are significant factors in the loss of historic data from wreck
                 sites. While commercial treasure hunters generally impact wrecks with intrinsic monetary value, sport divers
                 may collect souvenirs from an types of wrecks.
                      Tropical cyclones have the potential to impact archaeological resources by wave action and currents.
                 Archaeological resources located in shallow water and not protected by sediments could be scattered by wave
                 or current action.

                 (a) Historic

                      Future OCS exploration and development activities in the CPA are expected to result in the drilling of
                 5,890 exploration and delineation wells and 5,130 development wells, the installation of 340 platforms, and the
                 laying of 5,055 kin of offshore pipelines (Table IV-7). The archaeological surveys are expected to reduce the
                 potential for an interaction between an impact-producing activity and an historic prehistoric resource by 95
                 percent in those CPA areas that have a thin Holocene sediment veneer. Archaeological surveys are estimated
                 to be 90 percent effective in those CPA areas that have a thick blanket of unconsolidated Holocene sediments.
                 Archaeological surveys were first required in 1974, and it is therefore assumed that the major impacts to
                 historic resources resulted from development prior to 1974. The potential of an interaction between rig or
                 platform emplacement and an historic shipwreck is greatly diminished by the survey, but still exists. Such an
                 interaction could result in the loss of significant or unique historic information.
                      The placement of 5,055 kin of pipelines in the CPA is projected. According to Table IV-7, there are
                 currently 28,595 kin of pipelines on the Central Planning Area OCS. While the archaeological survey
                 minimizes the chances of impacting an historic shipwreck, there remains a possibility that a wreck could be
                 impacted by pipeline emplacement. Such an interaction could result in the loss of significant or unique historic
                 information.
                      The setting of anchors for drilling rigs, platforms, and pipeline lay barges, and anchoring associated with
                 oil and gas service vessel trips to the OCS have the potential to impact historic wrecks. The archaeological
                 surveys serve to minimize the chance of impacting historic wrecks; however, these surveys are not seen as
                 infallible and the chance of an impact from future activities exists. A total of about 708,000 shuttle tanker,
                 barge, and service vessel trips are projected for the CPA- Impacts from anchoring on an historic shipwreck
                 may have occurred. There is also a potential for future impacts from anchoring on an historicshipwreck. Such
                 an interaction could result in the loss of significant or unique information.
                      Oil spills have the potential to impact coastal historic sites directly or indirectly by physical impacts caused
                 by oil spill cleanup operations. According to Table IV-21 there is up to a 85 percent probability of an oil spill











                                                                                                                            IV-337

                greater than or equal to 1,000 bbI occurring and contacting the CPA coastal area within 10 days. There is up
                to a 73 percent probability that an imported oil spill greater than or equal to 1,000 bbl will occur and contact
                the CPA coastal area within 10 days. However, the impacts caused by oil spills to coastal historic
                archaeological resources are generally short term and reversible.
                    Most channel dredging occurs at the entrances to bays, harbors, and ports. These areas have a high
                probability for historic shipwrecks, and the greatest concentrations of historic wrecks are likely associated with
                these features (Garrison et al., 1989). It is reasonable to assume that significant or unique historic
                archaeological information has been lost as a result of past channel dredging activity. In many areas, the COE
                requires remote-sensing surveys prior to dredging activities to minimize such impacts (Espey, Huston, &
                Associates, 1990).
                    Past, present, and future OCS oil and gas exploration and development will result in the deposition of
                several tens of thousands of tons of ferromagnetic debris on the seafloor. This modern marine debris will tend
                to mask the magnetic signatures of historic shipwrecks, particularly in areas that were developed prior to
                requiring archaeological surveys in the CPA (offshore Subareas C-1, C-2, and C-3). Such masking of the
                signatures characteristic of historic shipwrecks may have resulted or may yet result in OCS activities impacting
                a shipwreck containing significant or unique historic information.
                    Trawling activity in the CPA would only affect the uppermost portions of the sediment column (Garrison
                et al., 1989). On many wrecks, this zone would already be disturbed by natural factors and would contain only
                artifacts of low specific gravity that have lost all original context.
                    According to Table IV-12, 2 gas processing plants requiring 40-60 ha of land will be constructed in coastal
                Subarea C4. In addition, 1 terminal requiring 7-24 ha, 2 separation facilities requiring 6 ha per 100,000 bbl
                oil equivalents processed, 3 pipeline landfalls, and 48 kin of onshore pipelines will be necessary to support total
                Central Planning Area OCS program activities. All of the above onshore facilities are expected to occur within
                coastal Subarea C4. Investigations prior to construction can determine if historic archaeological resources exist
                at the sites.
                    Because MMS does not have jurisdiction over pipelines in State waters, the archaeological resource
                protection requirements of the National Historic Preservation Act (NHPA) are not within MMS's jurisdiction.
                However, other Federal agencies, such as the COE, which lets permits associated with pipelines in State waters,
                            ible for the protection of archaeological resources under the NHPA_ Therefore, the impacts that
                are responsi
                might occur to archaeological resources by pipeline construction within State waters should be mitigated under
                the requirements of the NHPA.
                    Sport diving and commercial treasure hunting are significant factors in the loss of historic data from wreck
                sites. While commercial treasure hunters generally impact wrecks with intrinsic monetary value, sport divers
                may collect souvenirs from all types of wrecks. Since the extent of these activities is unknown, the impact
                cannot be quantified. However, assuming that any of the data lost have been unique, the impact would be very
                high.
                    About half of the coast along the Central Gulf was hit with 16-20 tropical cyclones between the years 1901
                and 1955 (DeWald, 1982). The other half, from Atchafalaya Bay in Louisiana to Texas, had a slightly lower
                incidence of cyclones (11-15). Shipwrecks in shallow waters are exposed to a greatly intensified longshore
                current during tropical storms (Clausen and Arnold, 1975). Under such conditions, it is highly likely that
                artifacts of low specific gravities (e.g. ceramics and glass) would be dispersed. Some of the original information
                contained in the site would be lost in this process, but a significant amount of information would also remain.
                Overall, a significant loss of data from historic sites has probably occurred, and will continue to occur, in the
                Central Gulf from the effects of tropical storms. Some of the data lost have most likely been significant or
                unique.

                Summary

                    Several impact-producing factors may threaten historic archaeological resources of the Central Gulf. An
                impact could result from a contact between an OCS activity (pipeline and platform installations, drilling rig
                emplacement and operation, dredging, and anchoring activities) and an historic shipwreck located on the
                continental shelf. The archaeological surveys and resulting archaeological analysis and clearance that are











                  IV-338

                  required prior to an operator beginning oil and gas activities in a lease block are estimated. to be 90 percent
                  effective at identifying possible historic shipwrecks in areas of the CPA with a high probability for the existence
                  of historic period shipwrecks and a thick blanket of unconsolidated sediments (offshore Subareas C-1, C-2, and
                  C-3). Development of the CPA prior to requiring archaeological surveys has possibly impacted wrecks
                  containing significant or unique historic information.
                      The loss of several tens of thousands of tons of ferromagnetic debris associated with oil and gas exploration
                  and development could result in the masking of historic shipwrecks. It is expected that dredging, sport diving,
                  commercial treasure hunting, and tropical storms have impacted and will continue to impact historic period
                  shipwrecks. Such impact will likely result in the loss of significant or unique archaeological[ information.
                      Onshore development as a result of the proposed action, could result in the direct physiad contact between
                  an historic site and new facility construction and pipeline trenching. It is assumed that archaeological
                  investigations prior to construction will serve to mitigate these potential impacts. While the likelihood of an
                  oil spill occurring and contacting the CPA coastline is high, expected effects on historic coastal resources are
                  temporary and reversible. Loss of significant or unique historic archaeological information from commercial
                  fisheries (trawling) is not expected.
                      The effects of the various impact-producing factors discussed in this analysis have likely resulted in the loss
                  of significant or unique historic archaeological information. In the case of factors related to OCS program
                  activities, it is reasonable to assume that most impacts would have occurred prior to 1974 (the date of initial
                  archaeological survey and clearance requirements). The incremental contribution of the proposed action is
                  expected to be very small due to the efficacy of the required remote-sensing survey and archaeological report
                  However, there is a possibility of an interaction between bottom-disturbing activity (rig emplacement, pipeline
                  trenching, and anchoring) and an historic shipwreck.

                  Conclusion


                      The total of OCS program and non-program related impact-producing factors has likely resulted and may
                  yet result in loss of significant or unique historic archaeological information.

                  (b) P@ehistoric

                      Future OCS exploration and development activities in the CPA are expected to result in the drilling of
                  5,890 exploration and delineation wells and 5,130 development wells, the installation of 340 -platforms, and the
                  laying of 5,055 kin of offshore pipelines (Table IV-7). The archaeological surveys are expected to reduce the
                  potential for an interaction between an impact-producing activity and a prehistoric resource by 90 percent.
                  Because archaeological surveys were first required in 1974, it is assumed that the major impacts to historic
                  resources resulted from development prior to 1974. The potential of an interaction between rig or platform
                  emplacement and a prehistoric site is diminished by the survey, but still exists. Such an interaction could result
                  in the -loss of significant or unique prehistoric information.
                      The placement of 5,055 km of pipelines in the CPA is projected. According to Table IV-7, there are
                  currently 28,595 km of pipelines on the Central Planning Area OCS. While the archaeological survey
                  minimizes the chances of impacting a prehistoric site, there remains a possibility that a site could be impacted
                  by pipeline emplacement. Such an interaction could result in the loss of significant or unique archaeological
                  information.
                      The setting of anchors for drilling rigs, platforms, and pipeline lay barges, and anchoring associated with
                  oil and gas vessel trips to the OCS have the potential to impact shallow, emplaced prehistoric sites. The
                  archaeological surveys minimize the chance of impacting these sites; however, these surve, are not seen as
                  infallible and the chance of an impact from future activities exists. A total of about 708,COO shuttle tanker,
                  barge, and service vessel trips are projected for the CPA (Table IV-12). Impacts from anchoring on a
                  prehistoric shipwreck may have occurred. Such an interaction could result in the loss of significant or unique
                  archaeological information.










                                                                                                                            IV-339

                    Oil spills have the potential to impact coastal prehistoric sites directly, or indirectly by physical impacts
               caused by oil spill cleanup operations. According to Table IV-21 there is up to a 85 percent probability of an
               oil spill greater than or equal to 1,000 bbl occurring and contacting the CPA coastal area within 10 days. There
               is up to a 73 percent probability that an oil spill greater than or equal to 1,000 bbl will occur and contact the
               CPA coastal area within 10 days. The impacts caused by oil spills to coastal prehistoric archaeological
               resources can severely distort information relating to the age of the site. Contamination of the site organics
               by modern hydrocarbons can render dating by C-14 methods useless. This loss might be ameliorated by artifact
               seriation or other relative dating techniques. Coastal prehistoric sites might also suffer direct impact from
               beach cleanup operations. Interaction between off-spill cleanup equipment and a site could destroy fragile
               artifacts or disturb site context, possibly resulting in the loss of information on the prehistory of North America
               and the Gulf Coast Region. Some coastal sites may contain significant or unique information.
                    Most channel dredging occurs at the entrances to bays, harbors, and ports. Bay and river margins have
               a high probability for the occurrence and preservation of prehistoric sites. Prior channel dredging has disturbed
               buried and/or inundated prehistoric archaeological sites in the coastal plain of the Gulf of Mexico. It is
               assumed that some of the sites or site information were unique or significant In many areas, the COE requires
               surveys prior to dredging activities to minimize such impacts.
                    Trawling activity in the CPA would only affect the uppermost portion of the sediment column (Garrison
               et al., 1989). This zone would already be disturbed by natural factors, and site context to this depth would
               presumably be disturbed. Therefore, the effect of trawling on prehistoric sites would be very low.
                    According to Table IV-12, 2 gas processing plants requiring 40 ha to 60 ha of land will be constructed in
               coastal Subarea C4. In addition, 1 terminal requiring 7 ha to 24 ha, 2 separation facilities requiring 6 ha per
               100,000 bbl off equivalents processed, 3 pipeline landfalls, and 48 kin of onshore pipelines will be necessary
               to support total Central Planning Area OCS program activities. All of the above onshore facilities are expected
               to occur within coastal subarea C-4.
                    Because MMS does not have jurisdiction over pipelines in State waters, the archaeological resource
               protection requirements of the NHPA are not within MMS's jurisdiction. However, other Federal agencies,
               such as the COE, which lets permits associated with pipelines in State waters, are responsible for the protection
               of archaeological resources under the NHPA_ Therefore, the impacts that might occur to archaeological
               resources by pipeline construction within State waters should be mitigated under the requirements of the
               NHPA
                    About half of the coast along the Central Gulf was hit with 16-20 tropical cyclones between the years 1901
               and 1955 (DeWald, 1982). The other half, from Atchafalaya Bay in Louisiana to Texas, had a slightly lower
               incidence of cyclones (11-15). Prehistoric sites in shallow waters and on coastal beaches are exposed to the
               destructive effects of wave action and scouring currents. Under such conditions, it is highly likely that artifacts
               would be dispersed and the site context disturbed. Some of the original information contained in the site would
               be lost in this process. Overall, a significant loss of data from prehistoric sites has probably occurred, and will
               continue to occur, in the Central Gulf from the effects of tropical storms.

               Summary

                    Several impact-producing factors may threaten prehistoric archaeological resources of the Central Gulf.
               An impact could result from a contact between an OCS activity (pipeline and platform installations, drilling
               rig emplacement and operation, dredging, and anchoring activities) and a prehistoric archaeological site located
               on the continental shelf. The archaeological surveys and resulting archaeological analysis and clearance that
               are required prior to an operator beginning oil and gas activities in a lease block are estimated to be 90 percent
               effective at identifying possible prehistoric sites in the CPA Development of the CPA prior to requiring
               archaeological surveys has possibly impacted sites containing significant or unique prehistoric information.
               Expected impacts from dredging and tropical storms are estimated to be very high under the Cumulative
               scenario. The likelihood of an off spill occurring and contacting the CPA coastline is high. Such contact could
               result in loss of significant or unique information relating to the dating of a prehistoric site. Onshore
               development as a result of the proposed action, could result in the direct physical contact between a prehistoric
               site and new facility construction and pipeline trenching. It is assumed that archaeological investigations prior










                IV-340

                to construction will serve to mitigate these potential impacts. The shallow depth of sediment disturbance
                caused by commercial fisheries activities (trawling) is not expected to exceed that portion of the sediments
                which have been disturbed by wave-generated forces.
                     The effects of the various impact-producing factors discussed in this analysis have likely resulted in the loss
                of significant or unique prehistoric archaeological information. In the case of factors related to OCS program
                activities, it is reasonable to assume that most impacts would have occurred prior to 1974 (the date of initial
                archaeological survey and clearance requirements). The incremental contribution of the proposed action is
                expected to be very small due to the efficacy of the required remote-sensing survey and concomitant
                archaeological report and clearance. However, there is a possibility of an interaction between bottom
                disturbing activity (rig emplacement, pipeline trenching, and anchoring) and a prehistoric archaeological site.

                Conclusion


                     The total of OCS program and non-program related impact producing factors has likely resulted and may
                yet result in loss of significant or unique prehistoric archaeological information.

                (12) Impacts on Socioeconomic Conditions

                (a) Population, Labor, and Employment

                     The Cumulative Analysis will focus on the direct, indirect, and induced impacts of the OCS oil and gas
                industry on the population, labor, and employment of the counties and parishes in the Central Gulf coastal
                impact area as a result of prior sales, the proposed sales, and future sales in the Gulf of Mexico. Considered
                also are employment impacts associated with the clean-up of oil spilled during import tankering operations.
                There would also be other economic impacts, both direct and indirect, associated with the OCS program
                resulting from its effect on other industries, such as commercial fishing, tourism, and recreational fishing. The
                direct benefit or loss in these industries is addressed in the sections of this EIS related specifically to those
                topics. The OCS program's indirect and induced effect on these associated industries is much more difficult
                to quantify. Nevertheless, it will generally constitute a fraction of the magnitude of the direct impact. Also
                discussed in the Cumulative Analysis are projected changes in the industrial composition of the regional
                economy.
                     Section III.C.1. provides an historical perspective of the oil and gas industry, as well as a brief description
                of recent events that have significantly affected the level of OCS activity in the Gulf of Mexico. A detailed
                discussion of historical trends in population, labor, and employment within the coastal impact area of the
                Central Gulf can be found in Section III.C.2. That section also includes a listing of counties and parishes in
                the Central Gulf coastal impact area, as well as current statistics and future projections of population, labor,
                and employment levels for coastal subareas in the region. These projections will serve as a baseline against
                which impacts will be measured. The methodology developed to quantify these impacts takes into account
                changes in OCS-related employment, along with population and labor impacts resulting from these
                employment changes within each individual coastal subarea. For a detailed description of the methodology
                used in this analysis, see Section IV.D.I.a.(12).
                     Baseline employment projections for the coastal impact area of the Central Gulf of Mexico can be found
                in Figure IV-9. Baseline employment projections, excluding jobs generated in the CPA by the OCS program
                during the 35-year life of the proposed action, are also displayed on this figure. The difference between these
                two sets of projections accounts for OCS program employment impacts to the counties and parishes of the
                Central Gulf resulting from prior sales, proposed sales, and future sales in the Central, Western, and Eastern
                Gulf of Mexico. Sales in the Western and Eastern Gulf can, and do, result in employment impacts to the
                Central Gulf. The methodology discussion in Section IV.D.l.a.(12) provides an in-depth treatment of the
                development of these projections.
                     A total of approximately 3,587,700 person-years of employment (direct, indirect, and induced) are required
                in the Central Gulf coastal subareas in support of the OCS Program in the Gulf of Mexico during the 35-year
















                                   2,600,1000
                                                                           Baseline Projection                 Without OCS Program

                                                                                                                     -------------


                                   2,400,000





                                   2,200,000





                                   2,000,000
                               E


                               E
                              LU   1'8w'oOO




                                   1,600,000





                                   1,400,000
                                                                                                                                 KA


                                                                                                       Year





                  Figure IV-9. Employment Impacts from the OCS Program (Central Planning Area) (USDOI, MMS, Gulf of Mexico <
                                      OCS Region estimates, 1991).










                 IV-342

                 life of the proposed action. Peak-year impacts occur the first year, in 1993, with approximately 151,400 workers
                 involved in primary, secondary, and tertiary industries. After this initial peak-year employment, impacts decline
                 steadily through the year 2027, reflecting the declining level of OCS-related oil and gas activity projected for
                 the Central Gulf. Direct employment in the primary oil and gas extraction industry (SIC 13) accounts for 45
                 percent of the total employment impacts projected for the Central Gulf coastal subareas over the life of the
                 proposed action. Exploratory activities peak in the year 2000. Both exploratory and development activities
                 account for approximately 13 percent of the total direct employment impacts resulting from the OCS program
                 in the Central Gulf during the 35-year life of the proposed action. Development and production operations
                 experience peak levels of activity in 1993, contributing 93 percent of the direct employment peak. The main
                 contributor to the overall total employment impact is production operations. Employmerit in oil and gas
                 production activities and workover operations accounts for over 86 percent of total direct employment impact
                 due to activities in the Central Gulf. Indirect and induced employment impacts in secondary and tertiary
                 industries amount to approximately 30 percent and 25 percent, respectively, of the total employment impact
                 over the life of the proposed action in the Central Gulf.
                     Table IV-31 displays the cumulative model projections of total OCS-related employment impacts (direct,
                 indirect, and induced) for each coastal subarea throughout the life of the proposed action. Table IV-32
                 provides estimates of annual impacts to the population and employment of each coastal subarea as a percent
                 of levels expected in absence of the OCS program. These impact estimates represent changes in the new share
                 of the existing population and employment that will be dependent on the OCS oil and gas industry for support
                 as a result of prior sales, the proposed sales, and future sales in the Gulf of Mexico. The Cumulative scenario
                 population and employment impact projections presented in this document are higher than those estimated
                 for recent past EIS's. The current analysis incorporates the benefit of improved information. on employment
                 level associated with existing offshore structures and workover operations. These data improvements account
                 for the larger impact projections.
                     The greatest impact to employment occurs in coastal Subareas C-1 and C-2, with peak-year impact
                 estimates for 1993 of approximately 18.2 and 14.9 percent, respectively. Coastal Subareas C-1 and C-2
                 collectively provide over 71 percent of the total employment required during the life of the proposed action
                 in support of the OCS program in the Central Gulf, The least impacted coastal subarea is C4, accounting for
                 only 4 percent of the total employment impact to the Central Gulf. Coastal Subarea C-3 contributes the
                 remaining 25 percent of total planning area employment impacts.
                     All coastal subareas are expected to experience peak impacts during the first year of the life of the
                 proposed action. The timing of these peak experiences suggests that activities resulting from prior sales are
                 responsible for a significant portion of the employment impact. New OCS development will allow the
                 continuation of some opportunities in the oil and gas industry for currently employed workers or future entrants
                 into the labor force already living in the area. The level of OCS-related employment projected for the Central
                 Gulf will continue to diminish as existing hydrocarbon resources become depleted. Continued leasing in the
                 OCS will only partially offset the decline in available oil- and gas-related employment in the counties and
                 parishes of the CPA.
                     Employment impacts resulting from oil-spill clean-up activities, because of their highly unpredictable nature,
                 were handled apart from the population and employment model. The level of employment associated with
                 any given clean-up operation is dependent on numerous variables which, in themselves, are also difficult to
                 predict. Nevertheless, the most labor-intensive clean-up operations are those from spills that contact the
                 coastline, particularly recreational beaches. For the purpose of this analysis, it is assumed that only those spills
                 contacting land will involve significant manpower requirements in their clean-up efforts.
                     Section IV.C. presents estimates of the mean number of offshore spills assumed as a result of the
                 Cumulative Case in the Gulf of Mexico. The probability that one or more offshore spills greater than or equal
                 to 1,000 bbl will occur as the result of the OCS program or import tankering and contact land segments of the
                 Central Gulf within 10 days of the accident can be found in Table IV-21. The highest probability that an
                 offshore spill of this size resulting from the OCS program will occur and contact a CPA land segment within
                 10 days is 54 percent for Plaquemines Parish (Land Segment 19) in coastal Subarea C-3. Terrebonne Parish
                 (Land Segment 16) in coastal Subarea C-2 carries the second highest probability of occurrence and contact,
                 with a probability of 32 percent. The probability that an offshore spill of this size will occur and contact any











                                                                                                                                 IV-343














                                                                      Table IV-31

                                           OCS-Related Employment Projections (Direct+Indirect+lnduced)
                                                                  Cumulative Scenario
                                                                    (person-years)


                YEAR                wl           W2            Cl           C2           C3           C4         WGOM*        CGOM**


                1993                  1365         8117         37946        61076        37438         5454         9483        141913
                1994                  1239         7318         34369        55390        33924         4955         8556        128639
                1995                  1287         7542         34153        55176        33562         4935         8829        127825
                1996                  1334         7774         34096        55222        33285         4904         9109        127507
                1997                  1458         8371         34341        55937        32994         4861         9829        128134
                1998                  1517         8658         34375        56163        32794         4854        10175        128185
                1999                  1600         9071         34717        56927        32798         4855        10671        129296
                2000                  1668         9373         34779        57185        32618         4848        11041        129430
                2001                  1544         8713         33682        55188        31965         4761        10257        125595
                2002                  1465         8259         32593        53283        31177         4679         9724        121732
                2003                  1347         7608         31417        51156        30436         4583         8955        117592
                2004                  1243         7001         29983        48619        29369         4437         8245        112408
                2005                  1328         7294         29178        47484        28211         4288         8622        109160
                2006                  1231         6771         28024        45497        27343         4163         8001        105027
                2007                  1179         6467         27201        44103        26612         4046         7646        101962
                2008                  1190         6456         26404        42888        25656         3895         7647        98844
                2009                  1171         6303         25579        41575        24856         3786         7474        95796
                2010                  1193         6366         25121        40909        24198         3672         7559        93900
                2011                  1207         6372         24427        39859        23258         3512         7579        91056
                2012                  1234         6433         23542        38513        22163         3349         7667        87567
                2013                  1235         6364         22481        36871        20991         3181         7598        83524
                2014                  1199         6168         21807        35762        20321         3054         7368        80943
                2015                  1164         5962         21001        34459        19555         2943         7126        77958
                2016                  1170         5941         20344        33462        18753         2817         7111        75377
                2017                  1145         5798         19726        32468        18193         2746         6943        73133
                2018                  1158         5820         19107        31567        17423         2630         6978        70726
                2019                  1120         5611         18391        30398        16727         2520         6731        68036
                2020                  1105         5521         17875        29579        16190         2437         6627        66082
                2021                  1090         5427         17340        28731        15667         2362         6517        64101
                2022                  1095         5436         16921        28099        15143         2277         6531        62440
                2023                  1045         5194         16344        27115        14632         2184         6239        60276
                2024                  1040         5156         15907        26438        14148         2114         6196        58608
                2025                  1017         5047         15541        25834        13840         2070         6063        57285
                2026                  1035         5118         15224        25385        13338         1979         6153        55926
                2027                  1019         5034         14820        24736        12929         1915         6053        54400


                                      43437       233866       888754      1453056       842508        126066       277303      3310383


                    western Gulf of Mexico.
                    Central Gulf of Mexico.

                Source: USDOI, KMS, Gulf of Mexico OCS Region estimates, 1991.






























                                                                                     Table IV-32

                                             Population and Employment Impact Levels for the Cumulative Case Scenario
                                                                            Cumulative Case Scenario
                                                                                     (percent*)



                      EMPLOYMENT IMPACT LEVELS:                                                  POPULATION IMPACT LEVELS:

                      YEAR,      W1         W2        Cl         C2        C3        C4          YEAR       W1        W2        Cl         C. 2       C3      C4


                      1993       0.4%-      0.3%      18. 2!%  14.9%       6.2%      1.4%        1993       0.4%      0.3%    18.2%     14.9%      6.2%      1.4%
                      1994       0.3%       0.3%      15.9%    13.0%       5.5%      1.21        1994       0.4%      0.3%    16.1%     13.2%      5.5%      1.3%
                      1995       0.4%       6.3%      15.4%    12.7%       5.3%      1.2%        1995       0.4%      0.3%    15.8%     12.9%      5.4%      1.2%
                      19961-     0.4%       0.3%      15,1%    12.5%       5.2%      1.2%        1996       0.4%      0.3%    15.7%     12.8%      5.4%      1.2%
                      1997       0.4%       0.3%      15.0%    12.5%       5.1%      1.21        1997       0.4%      0.3%    15.7%     12.9%      5.3%      1.2%
                      1998       0.4%       0.3%      14.8%    12.3%       5.0%      1.2%        1998       0.4%      0.3%    15.6%     12.8%      5.3%      1.2%
                      1999       0.4%       0.3%      14.7%    12.3%       4.9%      1.11        1999       0.4%      0.3%    15.7%     12.9%      5.2%      1.2%
                      2000,-     0.4%       0.3%      14.5%    12.2%       4.8%      1.11        2000       0.5%      0.4%    15.6%     12.9%      5.2%      1.2%
                      2001       0.4%       .0.3%     13.8%    11.6%       4.7%      1.1%        2001       0.4%      0.3%    15.0%     12.2%      5.0%      1.2%
                      2002       0.4%       0.3%      13.2%    11.0%       4.5%      1.1%        2002       0.4%      0.3%    14.3%     11.6%      4.9%      1.1%
                      2063       0.30       0.3%      12.5%    10.4%       4.4%      1.0%        2003       0.4%      0.3%    13.7%     11.0%      4.7%      1.1%
                      2004       0.3%       0.2%      11.7%      9.7%      4.2%      1.0%        2004       0.3%      0.3%    12.9%     10.3%      4.5%      1.1%
                      2005       0.3%       0.2%      11.3%      9.4%      3.9%      1.0%        2005       0.4%      0.3%    12.4%     10.0%      4.3%      1.0%
                      2006       0.31       0.2%      10.7%      8.8%      3.8%      0.9%        2006       0.3%      0.2%    11.8%       9.4%     4.2%      1.0%
                      2007.      0.31       0.2%      10.2i      8.5%.     3.6%      0.9%        2007       0.3%      0.2%    11.3%       9.1%     4.0%      1.0%
                      2008       0.3%       0.2%      9.8%       8.1%      3.5%      0.8%        2008       0.3%      0.2%    10.9%       8.7%     3.9%      0.9%
                      2009       0.31       0.2%      9.3%       7.8%      3.3%      0.8%        2009       0.3%      0.2%    10.5%       8.4%     3.7%      0.9%
                      2010.      0.3%_.     0.2%      9.1%       7.5%      3.2%      0.8%        2010       0.3%      0.2%    10.2%       8.1%     3.6%      0.8%
                      2011       0.3%       0.2%      8.7%       7.3%      3.0%      0.7%        2011       0.3%      0.2%      9.8%      7.9%     3.4%      0.8%
                      2012@      0.3%       0.2%      8.3%       6.9%      2.9%      0.7%        2012'      0.3%      0.2%      9.4%      7.5%     3.3%      0.8%
                      2013       0.3%       0.2%      7.8%       6.5%      2.7%      0.7%        2013       0.3%      0.2%      8.9%      7.1%     3.1%      0.7%
                      2014       0.3%,      0.2%      7.4i       6.3%      2.6%      0.61        2014       0.3%      0.2%      8.5%      6.8%     2.9%      0.7%
                      2015       O.W.       0.21      7.1%       6.0%      2.4%      0.6%        2015       0.3%      0.2%      8.2%      6.5%     2.8%      0.7%
                      2016       0.3%       0.2%      6.8%       5.7%      2.3%      0.6%        2016       0.3%      0.2%      7.8%      6.3%     2.7%      0.6%
                      2011       0.2%@      0.2%      6.5%       5.5%      .2.2%     0.61        2017       0.3%      Or2%      7.5%      6.0%     2.6%      0.6%
                      2018       0.2%       0.2%      6.2%       5.3%      2.1%      0.5%        2018       0.3%      0.2%      7.2%      5.8%     2.5%      0.6%
                      2019,      0.2%       0.2%      5.9%       5.0%      2.0%      0.5%        2019       0.3%      0.2%      6.9%    *5.5%      2.4%      0.6%
                      20iO@      0.2%       0.1%      5.7%       4.8%      1.9%      0.5%        2020       0.3%      0.2%      6.7%      5.3%     2.3%      0.5%
                      2021       0.2%       0.1%      5.4%       4.6%      1.8%      0.5%        2021       0.3%      0.2%      6.4%      5.1%     2.2%      0.5%
                      2022.      0.2%       0.1%      5.2%       4.5%      1.7%      0.4%        2022       0.3%      0.2%      6.2%      5.0%     2.1%      0.5%
                      2623,      0.2%       .0.1%     5.0%       4.3%      1.7%      0.4%        2023       0.2%      0.2%      6.0%      4.7%     2.0%      0.5%
                      2024       0.2%       0.1%      4.8%       4.1%      1.6%      0.4%        2024       0.2%      0.1%      5.8%      4.6%     1.9%      0.4%
                      2025       0.2%       0.1%      4.6%       4.0%      1.5%      0.4%        2025       0.2%      0.1%      5.6%      4.4%     1.9%      0.4%
                      2026       0.2%       0.1%      4.5%       3.8%      1.5%      0.4%.       2026       0.2%      0.1%      5.4%      4.3%     1.8%      0.4%
                      2027       0.2%       0.1%      4.3%       3.7%      1.4%      0.4%        2027       0.2%      0.1%      5.3%      4.2%     1.7%      0.4%


                        Note:    Impact levels represent the percent change in population or employment due to the proposal with respect
                                 to total levels expected in absence of the proposal.
                      Source: USDOI, KMS, Gulf of Mexico OCS Region estim'aies, 1991.'










                                                                                                                            IV-345

                particular land segment of coastal Subarea C4 in Mississippi and Alabama is less than 5 percent. Every land
                segment in coastal Subarea C-1 carries a probability of occurrence and contact equal to 6 percent. Based on
                these probabilities, the assumption is that three offshore spills of approximately 6,500 bbI will occur and contact
                land somewhere in the CPA as a direct result of the OCS program. An MMS study of off slick sizes and length
                of affected coastline provides statistics that lead to the assumption that, on average, a spill of this size would
                affect approximately 30 kin of coastline (USDOI, MMS, 1985c). Based on employment statistics from recent
                spill clean-up operations along the coast, the assumption is that, for every kilometer of coastline subjected to
                heavy oiling, approximately 100 temporary workers will be employed for a maximum of 6 weeks. Therefore,
                an estimated 3,000 workers will spend approximately 6 weeks employed in operations supporting the clean-up
                of each offshore OCS-related spill of this size that will contact the Central Gulf Coast. This estimate is
                equivalent to a total of 1,050 person-years of employment over the 35-year life of the proposed action.
                    The highest probability that an offshore spill greater than or equal to 1,000 bbl will occur from accidents
                involving import tankering and contact a CPA land segment within 10 days is 23 percent for Cameron Parish
                (Land Segment 12) in coastal Subarea C-1. Plaquemines Parish (Land Segment 19), in coastal Subarea C-3,
                has a slightly lower probability of occurrence and contact of 21 percent The probability that an offshore spill
                will occur and contact any particular land segment of coastal Subareas C-2 and C4 is less than 5 percent.
                Based on these probabilities, the assumption is, that one spill of approximately 22,728 bbI will occur from
                import tankering operations and contact a land segment somewhere in the CPA. Given the study and
                assumptions discussed above, this size spill would affect approximately 50 kin of coastline and require an
                estimated 5,000 workers in support of clean-up efforts for approximately 6 weeks. This estimate is equivalent
                to a total of 580 person-years of employment over the life of the proposed action.
                    Thirty three spills of the size category greater than 50 bbI and less than 1,000 bbI are assumed to occur
                in the CPA; however, none will contact the coastline. Eight-hundred and thirty spills of the size category
                greater than I bbl and less than or equal to 50 bbl are assumed to occur in the CPA over the life of the
                proposed action (Section W.C.I.). Of these spills, only a few are estimated to contact land. Furthermore,
                employment impacts resulting from the cleanup of spills this small are expected to be negligible.
                    In addition to the spills referenced in Table IV-19, a number of spins less than 1,000 bbl and crude oil spills
                greater than or equal to 1,000 bbI and petroleum product spills are assumed to occur, primarily in the coastal
                zone. Estimates regarding the size, source, and potential location of these spills can be found in Sections
                IV.C.1. and 3. The level of clean-up action associated with spills of this type will vary.
                    Employment levels in the impact area of the Central Gulf states are expected to increase approximately
                46 percent from the year 1990 over the life of the proposed action (Section III.C.2.). Projected changes in the
                industrial composition of the regional economy are considerable (USDOC, Bureau of Economic Analysis,
                1990). Mining employment is expected to decrease in Louisiana, Mississippi, and Alabama. The service
                industry is projected to exhibit the highest growth.
                    By the year 2020, mining employment in Louisiana is projected to decrease by about 20 percent from 1988
                levels (USDOC, Bureau of Economic Analysis, 1990). The construction industry and the government sector
                in Louisiana will also sustain a significant decline over this time period of approximately 11 percent and 8
                percent, respectively. In addition, the manufacturing and wholesale trade industries are projected to experience
                a modest reduction in employment levels. The sector of highest growth in Louisiana through the year 2020
                will very likely be the service industry, which includes establishments primarily engaged in providing a wide
                variety of services for individuals, business, government, and other organizations. Included in this sector are
                establishments highly dependent on the tourist industry, such as hotels and other lodging places, recreational
                camps and parks, amusement services, museums, art galleries, zoological gardens, automotive rental agencies,
                business advertising, and other miscellaneous personal services. The growth projected for the service industry
                in Louisiana comes as no surprise, considering the State's efforts to strengthen existing tourism activity in the
                region.
                    Mining employment in Mississippi and Alabama is expected to decline by 13 percent and 10 percent,
                respectively (USDOC, Bureau of Economic Analysis, 1990). The government sector is also projected to
                experience modest reductions in employment levels. The highest growth sector in these two states will very
                likely be the service industry. By the year 2020, the service sector in both Mississippi and Alabama is projected
                to grow by about 30 percent from employment levels experienced in 1988.










                IV-346

                    Population in the impact area of the Central Gulf states is expected to increase approximitely 24 percent
                from the year 1990 over the life of the proposed action (Section III.C.2). The greatest impact on population
                from activities associated with the OCS program is expected in those areas with the highest employment
                impacts, namely coastal subareas C-1 and C-2. Peak year population impacts for coastal areas C-1 and C-2
                occur in 1993 and are estimated to be 18.2 percent and 14.9 percent, respectively.

                Summary

                    From a cumulative standpoint, the OCS program has had a significant impact in some areas of the Central
                Gulf. Peak annual changes in the population, labor, and employment of two coastal subareas in the Central
                Gulf represent as much as 18.2 percent and 14.9 percent of the levels expected in absence of the OCS program
                in the Gulf of Mexico. However, although total employment impacts are significant, they do not exceed peak
                levels of activity already experienced in the Central Gulf. It appears that the recent growth in employment to
                levels expected in 1993 will represent the peak impact of the OCS program over the life of the proposed
                action. Employment needs in support of OCS oil and gas activity are likely to be met with the existing
                population and available labor force. Future OCS leasing is expected to offset only partially the declining level
                of activity already taking place in the off and gas industry offshore. Similar declining trends are projected for
                oil and gas production in State waters.
                    In light of the past and projected decline in oil and gas activities in the Central Gulf, there are numerous
                and significant efforts to diversify the local economies, particularly in Louisiana. A diversified economy will
                provide the coastal communities the opportunity to achieve net economic growth in spite of the downturn in
                the off and gas industry. The service industry, in particular, is projected to experience significant growth in the
                region over the life of the proposed action.
                    On a regional level, the cumulative impact from prior sales, the proposed actions, and future sales on the
                population, labor, and employment of the counties and parishes of the Central Gulf coastal impact area is
                significant (approximately 3,587,700 person years of employment over the life of the proposed action). The
                incremental contribution of the proposed action (as analyzed in Section IV.D.1.a.(12)(a)) to the cumulative
                impact level is minimal because peak annual changes in the population, labor, and employment of an coastal
                subareas in the Central and Western Gulf resulting from the proposed action in the Central Gulf represent less
                than 1 percent of the levels expected in absence of the proposal.

                Conclusion

                    On a regional level, the cumulative impact from prior sales, the.proposed actions, and future sales on the
                population, labor, and employment of the counties and parishes of the Central Gulf coastal impact area is
                significant, amounting to approximately 3,587,700 person-years of employment over the life of the proposed
                action, plus at least an additional 1,050 person-years of employment associated with the clean-up of three oil
                spills. Locally, the cumulative impact to population, labor, and employment is highest for coastil Subareas C-1
                and C-2 along the western and central Louisiana coastline, lower for coastal Subarea C-3 in southeast
                Louisiana, and lowest for coastal Subarea C-4 in Mississippi and Alabama. Employment needs in support of
                OCS oil and gas activity are likely to be met with the existing population and available labor force.
                (b) Public Services and Infrastructure

                    The Cumulative Analysis considers the effects of OCS-related, impact-producing factors from the Central,
                Western, and Eastern Gulf of Mexico, as well as the effects of prior, current, and future OCS sales, and the
                effects of non-OCS-related impact-producing factors. Impact-producing factors considered in the analysis
                include fluctuations in the work force, net migration, relative income, oil and gas activity from State waters,
                wetlands loss, and tropical storms. Unexpected events (such as the 1973 Arab Oil Embargo) may influence
                oil and gas activity within the Gulf of Mexico Region. These events cannot be projected ELnd will not be
                considered in this analysis.











                                                                                                                            IV-347

                    Public services and infrastructure, as used in this analysis, include commonly provided public, semipublic,
               and private services and facilities, such as education, police and fire protection, sewage treatment, solid-waste
               disposal, water supply, recreation, transportation, health care, other utilities, and housing. Changes in OCS
               activities, as well as changes caused by non-OCS-related, impact-producing factors, could result in changes in
               demands for and usage of public services and infrastructure. Adverse effects could arise if the amount or rate
               of increase or decrease in the usage significantly exceeded or fell far below the capability of a local area to
               provide a satisfactory level of service. In addition, a natural disaster, such as a hurricane, could significantly
               damage infrastructure and create a greater need for service than would be locally available.
                    Section III.C.1. provides an historical perspective of the oil and gas industry, as well as a brief description
               of recent events that have significantly affected the level of OCS activity in the Gulf of Mexico. Discussions
               of population, labor, and employment; public services; and social patterns are presented in Section III.C.2.
                    As shown in Table IV-31, approximately 3,310,383 person-years of employment (direct, indirect, and
               induced) are required in the coastal subareas of the Central Gulf to support OCS-related activities during the
               35-year life of the proposed action. Peak-year impacts occur during the first year (1993) with approximately
               141,913 workers involved in primary, secondary, and tertiary industries. Impacts decline after the peak-year,
               reflecting the projected decline in the level of OCS-related activities. The largest employment impact will occur
               in onshore subarea C-2 (Table IV-31). Examination of Table IV-32 reveals that the greatest impact to
               employment occurs in Subareas C-1 and C-2, with peak-year (1993) impact estimates of 18.2 and 14.9 percent,
               respectively. It is expected that the level of OCS-related employment projected for the CPA will diminish as
               existing hydrocarbon resources become depleted. It is assumed that continued leasing in the OCS will only
               partially offset the decline in available OCS-related oil and gas employment.
                    Fluctuations in the work force as a result of changing levels of OCS-related oil and gas activity could
               impact public services and infrastructure during the life of the proposed action. As mentioned above, following
               the peak-year (1993), total employment in the CPA is expected to decline. Projected changes in the industrial
               composition of the regional economy over the life of the proposed action reveal a decrease in mining
               employment in Louisiana of about 20 percent from 1988 levels (USDOC, Bureau of Economic Analysis, 1990).
               The growth industry in the CPA is expected to be the service industry. It is assumed for the purpose of analysis
               that the jobs created in the service sector will be lower paying jobs than those in OCS-related activities. This
               development may result in a lower tax base, making financing for new infrastructure needed in response to
               normal growth problematic. Layoffs associated with the projected decline in OCS-related employment may
               place stresses on those private and State agencies responsible for assistance.
                    Peak-year cumulative impacts are expected to occur in 1993. Following the peak-year, total OCS-related
               oil and gas employment in the CPA is expected to decline. As mentioned above, projected levels of mining
               employment in Louisiana are expected to drop by 20 percent by 2020. Expected growth in the service industry
               will most likely provide employment for some of the work force; however, it is assumed that some out-
               migration will occur among those persons seeking pay comparable to that of OCS-related employment. It is
               expected that employment needs in support of OCS oil and gas activity are likely to be met with the existing
               population and available labor force, requiring little to no in-migration. Out-migration could result in a large
               loss of population, particularly in OCS-related staging and administrative centers. This could stress the public
               service and infrastructure base of these centers because of dramatic changes in need.
                    The relatively high wages paid to OCS-related oil and gas industry personnel in the cumulative case will
               increase the tax base in coastal parishes and counties beyond what could be expected if there were no OCS
               activities. As OCS-related employment decreases through time, it is assumed that taxes originating from OCS-
               related wages and expenditures will decrease. Consequently, maintenance of existing infrastructure and
               creation of new infrastructure may become problematic.
                    Oil and gas activity within State waters requires similar public services and infrastructure as do OCS-related
               off and gas activities. Further, it is assumed that oil and gas employment from activities within State waters
               will decline at the same rate, if not faster, than that from Federal OCS waters. Infrastructure needs in support
               of oil and gas activities in State waters would diminish as employment associated with State-regulated activities
               decline. Impacts to public services would include increased numbers of individuals requiring assistance. In
               addition, maintenance of existing infrastructure and creation of new infrastructure may become difficult to
               support at different levels of oil and gas employment











                IV-348

                     About half of the Central Gulf coast was hit with 16-20 tropical cyclones between the years 1901 and 1955
                (DeWald, 1982). The other half, from Atchafalaya Bay in Louisiana to Texas, had a slightly lower incidence
                of cyclones (11-15). Experience with Hurricanes Betsy and Camille has indicated that major hurricanes can
                have a devastating effect on both public services and community infrastructure. Assuming that several major
                storms will impact the Central Gulf coastal subareas during the life of the proposed action, hundreds of millions
                of dollars of damage to existing infrastructure is expected.
                     Section IV.D.Ld.(1)(b) analyzes the cumulative impact to coastal wetlands. Decreases in sediment load
                and dispersal, subsidence, indirect impacts from existing canals, and other impact-producing factors are
                expected to result in the loss of thousands of acres of wetlands per year. Given the physiography of the CPA
                co astal parishes and counties of the CPA and the proximity of much infrastructure to relict geomorphic
                features, it is reasonable to assume that transportation networks (roads, bridges, and railroads) will require
                increasing maintenance and protection from inundation in the future. This is particularly true in the coastal
                marsh areas.


                Summayy

                     Declining levels of OCS and tideland oil and gas employment are expected to occur duririg the life of the
                proposed action. Economic growth is expected to occur in the service industry, however, the level of pay for
                these jobs will not be comparable to those lost from OCS-related employment It is assumed that some out-
                migration will coincide with declining levels of OCS-related employment and that it will primarily occur from
                OCS-staging areas and administrative centers.
                     The decline in the tax base and the needs for public and relocation assistance are expected to result in
                a deterioration of the existing community infrastructure and level of public service delivery.
                     Tropical storm activity has occurred in the past and will occur in the future. It is assumed that several
                major storms will strike CPA coastal parishes and counties during the life of the proposed action. Experience
                has indicated that these storms could have a major impact on public services and community infrastructure.
                     Community infrastructure in the coastal parishes and counties is linked to the region's physiography.
                Continued subsidence and erosion are expected to require expanded maintenance of roads, bridges, and
                railroads, particularly in CPA coastal marsh areas.

                Conclusion


                     The cumulative impact is expected to result in deteriorating conditions of existing infrastructure and
                difficulties in delivering satisfactory levels of public services.

                (c) Social PaUerm

                     The Cumulative Analysis considers the effects of OCS-related, impact-producing factors from the Central,
                Western, and Eastern Gulf of Mexico as well as the effects of prior, current, and future OCS sales. The
                analysis also considers the effects of certain non-OCS-related, impact-producing factors. Impact-producing
                factors considered in the analysis include work force fluctuations, net migration, displacement from traditional
                occupations, relative income, oil and gas activity from State waters, oil spills, wetlands loss, and tropical storms.
                Unexpected events (such as the 1973 Arab OR Embargo) may influence oil and gas activity within the Gulf of
                Mexico Region. These events cannot be projected and cannot be presumed for this analysis.
                     Social patterns, as used in this analysis, will include traditional occupations, folkways, social structure,
                language, family life, and other forms of cultural adaptation to the natural and human environment. It should
                be noted that impacts not treated in the present analysis (such as technological improvements in
                communications and transportation) have caused, and will continue to cause, changes within the analysis area.
                For the purpose of the current analysis, impact-producing factors to social patterns will include work force
                fluctuations, net migration (both in-migration and out-migration), work scheduling, displacement from
                traditional occupations (primarily resulting from wetlands loss), relative income, oil and gas activity within State











                                                                                                                            IV-349

               waters, and tropical storms. Adverse effects to social patterns could arise if disruption of social patterns
               occurred and resulted in changes in traditional occupations, disruption in the viability of extant subcultures, and
               detrimental effects on family life. As mentioned in Section 11I.C.2.c., it may be argued that employment in the
               oil and gas industry could be perceived as a traditional occupation. For the purpose of this analysis, such
               employment will not be considered as a traditional occupation.
                   Section III.C.1. provides an historical perspective of the oil and gas industry, as well as a brief description
               of recent events that have significantly affected the level of OCS activity in the Gulf of Mexico. Discussions
               of population, labor, and employment; public services; and social patterns are presented in Section III.C.2.
               Definitions used in this analysis to assess the OCS program's expected level of impact on social patterns is
               presented in Table S-5.
                   As stated in Section IV.D.Ld.(12)(a), approximately 3,587,700 person-years of employment (direct, indirect,
               and induced) are required in the Central Gulf coastal subareas to support OCS-related activities during the
               35-year life of the proposed action. Peak-year impacts occur in 1993 with approximately 151,400 workers
               involved in primary, secondary, and tertiary industries. Impacts decline after the peak year, reflecting the
               projected decline in the level of OCS-related activities. A breakdown.of total employment projections for the
               life of the proposed action by coastal subareas reveals total employment of 26.8 percent in Subarea C-1, 43.9
               percent in Subarea C-2, 25.5 percent in Subarea C-3, and 3.8 percent in Subarea C-4 (Table IV-33). An
               examination of Table IV-34 reveals that the greatest impact to employment occurs in Subareas C-1 and C-2,
               with peak-year impact (1993) estimates of 18.2 and 14.9 percent, respectively. It is expected that the level of
               OCS-related employment projected for the CPA will diminish as existing hydrocarbon resources become
               depleted. It is assumed that continued leasing in the OCS will only partially offset the decline in available
               OCS-related oil and gas employment.
                   The potential effects of work force fluctuations on extant subcultures in the coastal subareas are expected
               to be greatest when large changes in OCS-related activities result in net positive or negative migration. Under
               the Cumulative scenario, peak-year employment is projected to occur in 1993, with a steady decline in OCS-
               related employment over the life of the proposed action. It is likely that employment in OCS-related activities
               will not require importation of labor and that jobs will be filled by the available labor. Projected changes in
               the industrial composition of the regional economy over the life of the proposed action reveal a decrease in
               mining employment in Louisiana of about 20 percent from 1988 levels (USDOC, Bureau of Economic Analysis,
               1990). The highest growth in the CPA is expected to occur in the service industry. It is assumed for the
               purpose of this analysis that jobs created in the service sector will be lower paying than jobs in OCS-related
               activities. The quality of family life, in some individual cases, could be adversely affected from the stress of
               decreased family income and loss of security resulting from layoffs in the OCS oil and gas industry. As the
               level of employment in the OCS-related industry decreases, it is likely that more persons will engage in
               traditional occupations (such as trapping and shrimping) to supplement their income, possibly leading to
               overfishing of the resource, which could pose a threat to the continued existence of specific traditional
               occupations. The cumulative level of impact from work force fluctuations is expected to impact the quality of
               family life, particularly in Subareas C-1, C-2, and C-3. In addition, impacts to traditional occupations could
               result from overexploitation of the fisheries resource as individuals turn from employment in oil and gas
               activities to more traditional occupations.
                   As mentioned above, projected levels of mining employment in Louisiana are expected to drop by 20
               percent by 2020. Expected growth in the service industry will most likely provide employment for some of the
               work force; however, it is assumed that some out-migration will occur among those persons seeking pay
               comparable to that of OCS-related employment. It is expected that employment needs in support of OCS oil
               and gas activity are likely to be met with the existing population and available labor force, requiring little to
               no in-migration. Out-migration could result in a large population loss, particularly in OCS-related staging and
               administrative centers. Expected impacts would include a diminishment in the number of those persons
               engaged part-time in traditional occupations with the possible loss of cultural knowledge, the serious
               impairment in family life as a result of the departure of extended family members, and potential loss of
               community cohesion within some of the communities that serve as staging and administrative centers. The
               cumulative level of impact on social patterns from migration is expected to be high in some communities that
               serve as staging and administrative centers.











                  IV-350

                       Distance to the site and the type of transportation needed for personnel in OCS-related oil and gas
                  activities results in the normal work schedule occurring as a large block of time on duty (or at site) followed
                  by a large block of time off duty. The schedules may range from 7 days on followed by 7 days off to a 30-day
                  on/30-day off schedule. It has been argued that this type of schedule has allowed for paTticipation in, and
                  continuance of, traditional occupations (Hallowell, 1979; Laska, personal comm., 1991). It is expected that
                  stress will be placed on family life in response to the regular absences of a parent (usually the. father). In some
                  cases, it is expected that adaptation to changing family roles will occur. In other cases, it is expected that
                  adaptation will not occur and that there will be deleterious impacts to family life. In the peak year of 1993,
                  151,400 workers are projected to be involved in primary, secondary, and tertiary industries. Employment in
                  oil and gas production activities and workover operations are projected to account for about 86 percent of this
                  total. Of those persons employed in OCS-related oil and gas activities and working the extended schedule, it
                  is expected that some families will not adapt to these conditions, and deleterious impacts to family fife will
                  occur.
                      Displacement from traditional occupations could originate from destruction of a resource base, space-use
                  conflict, and voluntary shifts from traditional occupations to employment in OCS-related activities. Adverse
                  effects resulting from displacement from traditional occupations could include a diminishment in the number
                  of participants in traditional occupations, the loss of traditional knowledge and cultural heritage, and deleterious
                  impacts to family life. The existence of the Fisherman's Contingency Fund mitigates, to some, extent, space-use
                  conflicts associated with commercial fishing. A total of 1,640 claims have been filed as of 1990; 1,230 of these
                  in the Central Gulf. According to Section IV.D.Ld.(1)(b), the cumulative impact to coastal wetlands is
                  expected to be very high. Decreases in sediment load and dispersal, subsidence, indirect impacts from existing
                  canals, and other impact-producing factors are expected to result in the loss of thousands of acres of wetlands
                  per year. However, the incremental contribution of the proposed action is a very small part of this total. The
                  loss of habitat in the cumulative case is expected to adversely affect the pursuit of traditional occupations, in
                  the CPA over the life of the proposed action. The loss of habitat, over time, could result in a loss of traditional
                  occupations. Deleterious effects to family life could result from displacement and loss of traditional roles. The
                  cumulative level of impact from displacement from traditional occupations is expected to be high.
                      The relatively high wages paid to OCS-related oil and gas industry personnel may result in the voluntary
                  shift of persons engaged in traditional occupations to more lucrative positions within the oil and gas industry.
                  Dependency on these relatively high wages may deleteriously impact family life, particularly in view of the
                  projected decline in OCS-related oil and gas activity over the life of the proposed action. It is expected that
                  many persons who voluntarily leave traditional occupations for employment in OCS-related oil and gas activities
                  will engage in traditional occupations part-time. Some individual cases of serious impairment of family life is
                  expected to occur in association with those persons who, laid off from OCS-related oil and gas activity during
                  the life of the proposed action, cannot find jobs at comparable pay.
                      Oil and gas activities within State waters are assumed to result in similar adverse effects as do OCS-related
                  oil and gas activity. It is assumed that oil and gas employment from activities within State waters will decline
                  at the same rate, if not faster, than that from Federal OCS waters. As employment from these activities
                  declines through time, more persons may turn to full-time participation in traditional occupation, resulting in
                  overutilization of the resource and threatening the continuation of traditional occupations. Family life could
                  also be seriously impacted by the suite of impact-producing factors associa    'ted with activities in State waters.
                     About half of the Central Gulf coast was hit with 16-20 tropical cyclones between the years 1901 and 1955
                  (DeWald, 1982). The other half, from Atchafalaya Bay in Louisiana to Texas, had a slightl, lower incidence
                  of cyclones (11-15). Experience with major hurricanes in the historical record (cf. VujnoviA-.h, 1974), as well
                  as Hurricanes Betsy and Camille, has indicated that major hurricanes can have a devastating effect on both
                  the natural and human environment Temporary disruption of traditional occupations and severe impairment
                  of family life, in some individual cases, can result from the effects of tropical storms. It is assumed that several
                  major storms will impact the Central Gulf coastal subareas during the life of the proposed action.











                                                                                                                              IV-351

                 Summary

                     Several impact-producing factors will contribute to impacts expected to occur on social patterns during the
                 life of the proposed action. It is expected that these impacts will be greatest in coastal Subareas C-1, C-2, and
                 C-3.
                     Declining levels in OCS-related employment are expected to occur during the life of the proposed action.
                 Economic growth is expected in the service industry-, however, the level of pay of these jobs will not be
                 comparable to those lost from OCS-related employment. It is assumed that the decline in OCS-related
                 employment will result in more persons engaging in traditional occupations, resulting in overutilization of the
                 resource base and threaten the loss of traditional occupations. Serious impairment of family life is expected
                 to occur in some individual cases.
                     In the CPA, for the life of the proposed action, OCS-related jobs are expected to be filled by the available
                 labor pool. No in-migration is projected for the coastal subareas. Out-migration may occur as a result of
                 persons seeking pay comparable to that earned in OCS-related industries. Comparatively large amounts of out-
                 migration may occur within localized communities that serve as OCS-related staging and administrative centers,
                 resulting in deleterious impacts to family life in some individual cases. The loss of some persons engaged in
                 the part-time pursuit of traditional occupations would also occur.
                     The specialized schedule that is necessary for the operation of many OCS-related activities is expected to
                 impair family life seriously in the case of families unable to adapt to changing roles. Deleterious effects on
                 traditional occupations are mitigated by schedule flexibility that allows for part-time participation in traditional
                 occupations.
                     Displacement from traditional occupations could occur as a result of destruction of the resource base
                 (primarily loss of wetlands), space-use conflicts, and voluntaryshifts from traditional occupations to OCS-related
                 employment. The loss of wetlands under the cumulative case is expected to amount to thousands of acres per
                 year. This loss, through time, is expected to seriously impact traditional occupations, cultural heritage, and
                 family life; it may result in the loss of traditional occupations.
                     Adverse effects from relative wages are expected to be greatest among families who have grown dependent
                 upon the relatively high level of wage paid to persons employed by OCS-related industries. Serious impairment
                 of family life is expected to occur in some individual cases.
                     Oil and gas activity within State waters is assumed to decline at the same rate, or at a faster rate, than that
                 projected for Federal OCS waters. Impact-producing factors are expected to parallel those found for activity
                 in Federal OCS waters. The levels of impacts are expected to parallel those found for OCS-related activities.
                     It is assumed that several tropical storms will make contact with the Central Gulf coastal subareas during
                 the life of the proposed action. Experience has shown that these storms can have a devastating, but temporary,
                 impact on traditional occupations. Serious impairment of family life is expected to occur in some individual
                 cases.
                       The incremental contribution to the proposed action (as analyzed for the Base Case in Section
                 IV.D.La.(12)(c)) to the cumulative impact level is minimal because there are no expected dramatic short-term
                 increases or decreases in population of the coastal parishes and counties. In addition, minimal net migration
                 into the coastal subareas is expected, and jobs created by the proposed action will reduce out-migration. The
                 extended work schedules and relatively high wages associated with OCS-related employment will cause minor
                 displacement from traditional occupations.

                 Conclusion


                     Under the Cumulative scenario, it is expected that some loss of traditional occupations will occur.
                 Deleterious impacts to cultural heritage and family life are also expected to occur in some individual cases.
                 It is expected that these impacts will be greatest in coastal Subareas C-1, C-2, and C-3.










                 IV-352

                 e. Coastal Zone Management Plans and Land Use

                     Coastal management policies apply to Sale 142 and to all subsequent activities that affect uses or resources
                 of the coastal zone. Section III.C.6. contains an overview of State Coastal Zone Management Plans. The
                 following assessment focuses on the hypothetical direct and indirect effects of postlease activities (the Base
                 Case scenario of the EIS). Changes made by the lessees as they explore, develop, and produce petroleum
                 products from leases offered in Sale 142 would affect the applicability of this assessmen-L The MMS is
                 generally prohibited from issuing drilling permits until after the consistency certification review is completed
                 and affirmed by a State. Additional information on the Base Case scenario can be found in Section IV.A.1.

                 (1) Alabama

                     The sale analysis area closest to the submerged lands of the State of Alabama is Central coastal Area C-3,
                 which extends offshore from the State 3-mi line. The Alabama coastal counties are Baldwin and Mobile.
                     According to NOAA, there are no local coastal management plans approved for the Slate of Alabama.
                 However, local authorities such as municipal and county planning commissions serve in an advisory capacity
                 to local government and, in certain instances, have authority to make development decisions that impact the
                 coastal area. The South Alabama Regional Planning Commission provides ongoing technical assistance to the
                 Alabama Department of Economic and Community Affairs (ADECA) so as to assure consistency with the
                 Alabama Coastal Area Management Plan's (ACAMP) guidelines and objectives when the ADECA lacks
                 sufficient personnel locally to coordinate the coastal area program with local planning commissions. Conflicts
                 with local land use ordinances are not expected to occur as a result of Sale 142, as existing onshore
                 infrastructure is expected to be sufficient.
                     Issues identified in ACAMP include the following coastal resource issues: coastal development and mineral
                 resources, commercial fishing, hazards management, shoreline erosion, recreation, and transportation. In
                 addition, the following natural resource protection policies are listed: biological productivity, air and water
                 quality, water resources, wetlands and submersed grassbeds, beach and dune protection, wildlife habitat
                 protection, endangered species, and cultural resources protection.
                     Based on assumptions fully discussed in Sections IV.A_ and W.C., the impacting factors discussed below
                 are assumed for the purposes of analysis. These factors will affect coastal issues identified in ACAMP.

                 Coastal Resource Use Policies


                     Coastal Development and Mineral Resources

                     The State policy on development encourages and supports "to the maximum extent practicable the
                 continued development of the economic resources of the coastal area, including the port, industrial, energy and
                 recreational resources, so that they may continue their full contribution to the economic well-being of all
                 citizens, and development within coastal Alabama will be carried out in a manner which is consistent with the
                 Board's policies for natural resources" (Policy Statement, Part II, Ch. 3, Sec. LA-1., ACAMP).
                     It is also the State's policy to "encourage the extraction of mineral resources in coastal Alabama consistent
                 with the water quality policies and natural resource policies of the Board" (Policy Statement, Part 11, Ch. 3, Sec.
                 I.A.2., ACAMP).
                     The proposed sale will not directly involve development of mineral resources in State lands, though perhaps
                 common depth point data and/or exploration of leases near State lands could shed light on potential energy
                 resources beneath State acreage. In addition, the lease sale may create new jobs and may generate other
                 economic opportunities to the benefit of Alabama and the Nation. An MMS-funded study (Laska, in progress)
                 evaluates the effect of the downturn in the oil industry on the Gulf economy and investigates alternate uses
                 of existing OCS infrastructure for economic development opportunities. Any change of existing social patterns
                 in coastal Alabama as a result of activities on these offshore leases is highly unlikely. Because the coastal zone
                 resources are currently unemployed and underemployed, the sale will result only in a continuation of existing











                                                                                                                            IV-353

                facilities without notable alteration of social patterns. Jobs created as a result of the sale would likely reduce
                the amount of out-migration when compared to scenarios without the proposal. Economic considerations are
                also evaluated in the Secretarial Issue Document and the Decision Memorandum for this sale.
                    Onshore support activities hypothesized to result from activities on these offshore leases will themselves
                be subject to separate State permits and consistency certification reviews.

                    Commercial Fishing

                    It is the policy of the State of Alabama "to maintain conditions that support present populations, and where
                feasible, to enhance marine species and to encourage conservation practices favoring increases of marine and
                estuarine species which will increase the potential yield of Alabama's coastal fisheries" (Policy Statement, Part
                11, Ch. 3, Sec. I.A.3., ACAMP).
                    Sale 142 is not likely to have any significant effects on recreational or commercial fishing in the Alabama
                coastal zone because the chance of an oil spill occurring and reaching the coast is remote. Further, OCSLA
                mandates MMS to ensure continued protection and viability of OCS commercial fisheries.
                    Several Federal measures are available to mitigate fisheries losses beyond the coastal zone, losses that may
                occur as a result of activities on offshore leases. The Fishermen's Contingency Fund, authorized in OCSLA,
                is available to pay compensation for damages resulting from fishing gear losses. The MMS regulations (30 CFR
                250.40) require identification of subsea object locations and equipment marking to help establish liability for
                fishing gear losses associated with offshore oil and gas operations. Offshore structures enhance fishing
                opportunities.
                    Biological stipulations proposed for this sale contain special provisions for the regulation of discharges and
                siting of facilities within offshore areas recognized as live-bottom areas of exceptional biological productivity.
                These stipulations will help to protect fisheries resources. A large number of studies of mud and cutting
                discharges from offshore oil and gas operations (e.g., NRC, 1983; Zingula, 1975; Menzie, 1983) show rapid
                dispersal by ocean currents with no long-term, significant biological effects.

                Hazards Management

                    Itis Alabama's policy that "human activities within hazard management areas, including flood and hurricane
                prone areas, will be carried out in a manner which sustains the area's natural capability of absorbing the effects
                of flood and hurricane events, and development within these areas shall be designed, located, and constructed
                in a way that minimizes the possibility of property damage and human suffering resulting from hazardous
                events."
                    Future onshore support is expected to be provided from existing facilities. However, if any hypothesized
                postlease onshore activities were to occur in Alabama, they would be subject to specific State permits including
                provisions to ensure consistency with State hazards management programs and policies.

                    Shoreline Erosion


                    It is the policy of Alabama that "the existing natural or manmade character of coastal shorelines shall be
                maintained in a manner to prevent the erosion of the Alabama coastline with primary emphasis on
                nonstructural forms of erosion control, and where feasible, enhancement of the natural protective functions
                of the shoreline shall be encouraged" (Policy Statement, Sec. I.A.5., ACAMP).
                    As indicated in Section IV.Al., onshore support is expected to be provided entirely from existing facilities.
                However, if any hypothesized postlease onshore development were to occur in Alabama, it would be subject
                to control by applicable State regulations to ensure consistency with State hazards management programs and
                policies.










                IV-354


                     Recreation

                     It is the Policy of Alabama that "public access to and use of existing recreational lands and waters, such
                as beaches, marinas, and fishing grounds, will be safeguarded," and the State "encourages the development of
                additional recreational opportunities to enhance the well-being of Alabama citizens as well as residents of other
                States" (Policy Statement, Part 11, Ch. 3, Sec. I.A.6., ACAMP).
                     As indicated in Section W.A., onshore support is expected to be provided from existing facilities. Marine
                debris lost from OCS operations associated with drilling and production throughout the lease life may occur
                from time to time, but the effect of intermittent washup of debris on recreational use of Alabama beaches
                should be low. The regulations at 30 CFR 250.40 require that offshore operators handle, control, mark, and
                dispose of containers, equipment, and solid waste through stringent marking, equipment handling, and storage
                requirements. The MMS inspectors check for compliance with regulations during daffy offshore inspections.
                Failure to comply with regulations leads to official warnings to take corrective action or, if warranted, to cease
                operations.
                     Based on information collected at beach cleanups and during marine debris surveys, the estimate is that
                existing offshore off and gas operations are responsible for 10-15 percent of the trash and debris adversely
                affecting the Gulfs shorefront recreational beaches in the CPA Recent Federal regulations (33 CFR 151)
                stemming from MARPOL Annex V, as well as periodic MMS directives and information seminars on the debris
                issue, should lead to better waste handling and less accidental loss of materials and personal items into the
                marine environment from offshore off and gas operations. Additionally, industry education and training
                emphasis on waste management, along with voluntary stewardship commitments by several major oil companies
                (the adoption of about 30 mi of Louisiana Gulf beaches, and the reduction and recycling of waste materials
                generated offshore), will also be reflected in a positive way on Alabama's beaches.
                     In addition, no oil spill greater than or equal to 1,000 bbl is assumed to contact the coast of Alabama as
                a result of this lease sale. Thus, there is no reason to expect that future activities on offshore leases will affect
                any areas reserved for recreational uses. If such future activities are proposed, they Will be subject to State
                consistency certification review and, in the case of development, separate State permits.

                     Transportation

                     It is the policy of Alabama that "recognizing the need for safe, convenient, rapid and economic access to,
                through and from Alabama's coastal lands and waters, the [ADEM] shall encourage and support the orderly
                growth of the area's transportation network, provided this growth is consistent with the Board's policies
                regarding natural resources" (Policy Statement, Part 11, Ch. 3, Sec. I.A.7., ACAMP).
                     Hypothesized transportation activities related to activities on these offshore leases may include delivery of
                supplies to onshore service bases and subsequent transfer of such supplies to offshore operational locations,
                transport of work crews to and from offshore locations, and possible future delivery of hydroca rbon discoveries
                to onshore process locations.
                     Most of the production from this lease sale may be connected by new pipelines to existing trunk lines for
                transportation to existing onshore processing facilities in Mississippi, Louisiana, and possibly Texas. If
                hypothesized postlease transportation activities occur in Alabama, they will be subject to separate State permits
                and regulations and State consistency review.

                Natural Resource Protection Policies


                     Biological P@oductivity

                     It is the policy of Alabama "to maintain present levels of plants and animals within coastal Alabama; to
                enhance, where feasible, biological productivity; and to monitor directly these levels through regular sampling"
                (Policy Statement, Part II, Ch. 3, Sec. II.A.I., ACAMP).
                     Onshore support facilities and related activities that could result from development on these offshore leases
                are hypothesized to be of very limited extent and are unlikely to have significant effects on coastal resource










                                                                                                                          IV-355

               protection. Such activities will be described in postlease exploration or development and production plans,
               which will be subject to State consistency review and, in the case of development, win need separate State
               permits. Offshore structures enhance biological productivity due to the reef environment created by them.
                   Coastal zone biological resources may be affected by oil spills associated with offshore operations.
               Prevention and containment and cleanup of oil spills are addressed through various Federal mitigation and
               regulation measures. Such measures include MMS requirements for an oil-spill contingency plan, prevention,
               and response (30 CFR 250.33,250.34, and 250.42); the platform verification program (30 CFR 250.131, 250.132,
               and 250.133); and the general OCSLA requirement to apply the best available and safest technologies (BAST).
               The MMS requires that oil-spill contingency plans (30 CFR 250.42) ensure a full-response oil-spill containment
               capability, including specification of appropriate equipment and materials, their availability and deployment
               time, and provisions for varying degrees of response effort, depending on the severity of the spill. The
               USEPA's development and implementation of the National Oil and Hazardous Substances Pollution
               Contingency Plan (NCP) (40 CFR 112) and correlative regional plans are designed to provide a coordinated
               and integrated response by Federal and State agencies to protect the environment from the damaging effects
               of accidental oil spills and pollution discharges.
                   The NCP requires that the U.S. Coast Guard's on-scene coordinator (OSC) obtain the concurrence of the
               USEPA representative to the Regional Response Team (RRT) and, as appropriate, the concurrence of the
               RRT representatives from the states having jurisdiction over the navigable waters threatened by the release
               or discharge; and that, when practicable, the OSC consult with the DOC and DOI natural resource trustees
               prior to authorizing the use of a chemical agent. Approved chemical agents must be listed on the NCP Product
               Schedule. Ile OSC is not required to obtain the aforementioned concurrence when, in the judgment of the
               OSC, the use of a chemical agent is necessary to prevent or reduce substantially a hazard to human life.
               Consistent with this, a Memorandum of Understanding, dated August 16, 1971, between the Department of
               the Interior and the Department of Transportation allows MMS the authority to grant OCS operators approval
               to use chemical agents within a 500-m radius of the source of pollution to abate the source of pollution only
               when such agents are deemed necessary as a measure for the safety of personnel and operations.

                   Water Quality

                   It is the policy of Alabama "to maintain the coastal waters of the State at a quality which will support
               present levels of estuarine organisms, plants and animals and, where feasible, to enhance and restore water
               quality to support optimum levels of estuarine organisms, plants, and animals (Policy Statement, Part II, Ch.
               3, Sec. II.A.2., ACAMP).
                   The quality of nearshore and offshore waters is protected through standards and requirements for NPDES
               permits (40 CFR 122), as mandated in the Federal Water Pollution Control Act (33 U.S.C. 1251 et seq., as
               amended). Marine water quality is protected through regulatory requirements, monitoring, and enforcement
               actions of MMS and USEPA. Discharges in coastal areas are also subject to provisions of the Alabama Code
               establishing the Alabama Water Improvement Commission, which is now the Water Division of the ADEM.
               'Me MMS has established a policy that requires the submission, for approval, of detailed plans for the disposal
               of all produced solids accumulated as a result of OCS activities (LTL dated November 20, 1990). The existing
               authorities on- and offshore cited above are sufficient to ensure that future operations on these offshore leases
               are unlikely to affect water quality adversely.
                   No onshore water quality degradation is likely to occur in Alabama as a result of activities on offshore
               leases because no new service bases are likely to be constructed in Alabama (EIS Base Case scenario).
               Therefore, no additional point source and nonpoint sources of pollution are likely to resUIL In the unlikely
               event of any such occurrence, numerous Federal and State water pollution control regulations exist for
               mitigating any potential adverse effects.

                   Water Resources


                   "Recognizing that the water resources of the coastal area are held in trust by the State of Alabama for the
               population of the State," it is Alabama's policy that "these resources shall be managed to ensure the sufficient










                 IV-356

                 quantities of clean water are available to meet present and future demands" (Policy Statement, Part 11, Ch. 3,
                 Sec. II.A.3., ACAMP).
                     Typically, to about 1,000 ft, only seawater is used in the Gulf for drilling an offshore well; between 1,000
                 and 6,000 ft, only seawater gel mud is used; at greater depths, a freshwater lignosulfonate mud is substituted.
                 A small amount of potable water will be needed for domestic uses of personnel living on ofNhore platforms,
                 but the quantity needed for offshore operations on these leases is likely to be insignificant in coastal Alabama.

                     Air Quality

                     It is the policy of Alabama "to maintain air quality in coastal Alabama at a level which supports the health
                 and well-being of Alabama's citizens and, where feasible, to enhance air quality (Policy Statement, Part II, Ch.
                 3, Sec.1l.A.4., ACAMP).
                     Section 5(a)(8) of the OCSLA grants the Department of the Interior exclusive authority aind responsibility
                 to prescribe regulations requiring offshore sources of air emissions to be consistent with national ambient air
                 quality standards to the extent offshore activities significantly affect the onshore air quality of a State. Thus,
                 the Department's regulations are the applicable air pollution control requirements of ACANIP under Section
                 307(f) of the Coastal Zone Management Act (CZMA) for OCS emissions.
                     The MMS regulations (30 CFR 250.44, 250.45, and 250.46) require offshore lessees to determine through
                 modeling whether their air emissions would result in onshore pollutant concentrations above significance levels.
                 If these levels are projected to be exceeded in an area whose concentrations already exceed air quality
                 standards, the lessee will be required to control fully or offset its emissions so that there would be no effect
                 onshore. If the significance levels are exceeded in areas at present in compliance with standards, the lessee
                 will be required to employ best available control technology (BACT). If predicted onshore concentrations still
                 exceed a standard for the prevention of significant deterioration, measures beyond BACT will be required.
                     Section 328 of the Clean Air Act (42 U.S.C 7401-7642, as amended) directed the Department of the
                 Interior to conduct a research study examining the impacts from activities on the OCS adjacent to Texas,
                 Louisiana, Mississippi, and Alabama on areas that fail to meet the Federal air quality standards for ozone (40
                 CFR 50). The MMS has been consulting with USEPA, the States, and others to design a study that will start
                 in 1992. The study will have the following components: (a) a characterization of meteorological regimes
                 associated with ozone episodes in nonattainment areas, (b) an evaluation of meteorological and air quality data
                 from ozone modeling, (c) application of photochemical modeling to estimate impacts from OCS activities on
                 ozone nonattainment areas, (d) a limited field program to collect meteorological data in offshore and coastal
                 areas for future modeling applications, and (e) a set of recommendations for future monitoring and modeling
                 activities.
                     In addition to the air quality study being planned in Gulf of Mexico, MMS and USEPA have been
                 consulting on the possibility of conducting a preliminary ozone study using the ROM model. A complete set
                 of results and impact assessment will be made when the 3-year study is completed. The EIS (Sections
                 IV.D.La.(4) and IV.D.2.a.(4)) reflects MMS's needs and commitment to gather information on ozone formation
                 and dispersion from OCS emissions.
                     The EIS analysis (Section IV.A.2.d.(6)) indicates that offshore air emissions are not likely to cause
                 degradation of onshore air quality and are not likely to have any significant effect on tionattainment or
                 Prevention of Significant Deterioration Class I areas. Actual measures ordered by the MMS will be determined
                 after additional site-specific studies results are included by lessees when they submit exploration and
                 development and production plans for approval.

                     Wetlands and Submersed Grassbeds

                     It is the policy of Alabama to maintain the "quality and quantity of coastal wetlands and submersed
                 grassbeds ... at the level necessary to provide for present levels of habitat for both terrestrial and aquatic life
                 to play their pivotal role in the aquatic food web and to provide natural control for shoreline erosion and,
                 where practicable, to enhance the quality and quantity of these wetlands and submersed grassbeds" (Policy
                 Statement, Part 11, Ch. 3, Sec. II.A.5., ACAMP).











                                                                                                                               IV-357

                    Wetlands and submersed grassbeds are essential to coastal zone biological productivity. See Section
                IV.D.l.e.(2) (Louisiana) for a relevant discussion of wetland impacts and OCS oil and gas activities. If any new
                onshore facilities are proposed for offshore lease development, potential effects to wetlands and submersed
                grassbeds in the State's coastal zone will be subject to State consistency certification review. Offshore activities
                would be located away from wetlands and submerged grass beds.

                    Beach and Dune Protection


                    "Recognizing the natural value of beaches and dunes for erosion control, wildlife habitat, and recreational
                opportunities," it is Alabama's policy "to maintain the natural integrity of the beach and dune systems and to
                restore and enhance these valuable resources where feasible" (Policy Statement, Part 11, Ch. 3, Sec. II.A-6.,
                ACAMP).
                    No new pipeline landfalls or onshore pipeline projects are anticipated in Alabama as the result of offshore
                lease activities in the Base Case scenario. The chance of an oil spill reaching the coast of Alabama is remote.

                    Wildlife Habitat Protection

                    It is Alabama's policy "to maintain areas of wildlife habitat sufficient to support present levels of terrestrial
                and aquatic life, including fish and shellfish, and preserve endangered species of plants and animals and, where
                feasible, to provide for optimum levels of terrestrial and aquatic life" (Policy Statement, Part II, Ch. 3, Sec.
                II.A.7., ACAMP).
                    As discussed in Section IV.D.j potential effects of activities on these offshore leases to coastal habitats are
                projected to be very low. Furthermore, all postlease activities and onshore facilities will be subject to State
                consistency certification review.

                    Endangered Species

                    It is the policy of Alabama "to promote and encourage the preservation of the critical habitat of recognized
                endangered species" (Policy Statement, Sec. II.A.8., ACAMP).
                    The consultation process established under Section 7 of the Endangered Species Act reviewed possible
                impacts from leasing and exploration activities on endangered and threatened species and concluded that their
                continued existence and habitats are not likely to be jeopardized by activities on these leases.
                    Potential effects on species such as whales, brown pelicans, and loggerhead turtles are considered in this
                EIS and give reason for no significant concern regarding Alabama coastal areas. If concerns for any such
                species are later identified, Federal and State endangered species authorities will take steps to ensure their
                protection.

                    Cultural Resources Protection


                    "Because of the wealth of unique and representative archaeological and historic sites in coastal Alabama
                and their educational and culturalvalues," it is Alabama policy "to support preservation and protection of
                Alabama's cultural resources" (Policy Statement, Part II, Ch. 3, Sec.II.A-9., ACAMP).
                    Protection of cultural resources in coastal areas will be ensured by the State of Alabama through this policy
                and by local units of government through direct land use controls. Further, Federal laws such as the National
                Historic Preservation Act will protect onshore historic and prehistoric resources that might be affected by this
                lease sale. The State Office of Historic Preservation will have opportunities to consult with MMS on protection
                of onshore historic resources, if development is proposed on any lease.

                Policy Erceptions for Compelling Public Interest

                    Uses that are determined to degrade the coastal area may be in compliance with the management program
                if the ADEM finds that there is a "compelling public interest." A compelling public interest is described as










                 IV-358

                 being more than mere convenience. It is a right recognized by law, or an economic, environmental health, or
                 social interest shared by most persons in the coastal area and which, if not recognized and protected, would
                 jeopardize the public well-being. The burden of proof that a particular use is of compelling public interest is
                 upon the applicant. In any determination of compelling public interest, the ADEM must consider (a)
                 significant national interest, (b) enhancementor protection of geographic areas of particular concern and areas
                 of preservation and restoration, and (c) significant economic benefit factors. In each review, the ADEM finds
                 whether the use is, on balance, consistent with the management program (see General Rules, Sec. B.2.,
                 ACAMP).

                 (2) Louisiana

                     The sale analysis area adjacent to the submerged lands of the State of Louisiana is the Central Planning
                 Area, made up of Central coastal Subareas C-1, C-2, and C-3, which extend offshore from the State 3-mi limit
                 T'wenty-one coastal parishes of Louisiana are involved.
                     Appendix C2 of the Louisiana Coastal Zone Management Plan (LCZMP) outlines the rules and
                 procedures for the State's local coastal management programs. Under the LCZMP, parishes are authorized,
                 though not required, to develop local coastal management programs. Approval of these programs gives the
                 parishes greater authority in regulating coastal development projects that entail uses of local concern.
                 Priorities, objectives, and policies of use of local land use plans must be consistent with the policies and
                 objectives of Act 361 and the State guidelines, except for a variance adopted in Section IV.D. of Appendix C2.
                 The Secretaries of the Departments of Natural Resources and Wildlife and Fisheries may Jointly rule on an
                 inconsistent local program based on local environmental conditions or user practices.
                     State and Federal agencies first review parish programs before they are adopted. According to NOAA,
                 the State of Louisiana has seven approved local coastal management programs (Lafourche, Jefferson,
                 Calcasieu, Orleans, Cameron, St Bernard, and St James Parishes). Two others, St. Charles and St. Tammany,
                 are pending NOAA approval. The parish police jury often serves as the permitting agency for projects limited
                 to local concern. Parish level programs function in an advisory capacity to Louisiana's C ZM agency, the
                 Coastal Management Division. The energy facility planning process is comprehensively outlined in Appendix
                 E of the LCZMP. Conflicts with local land use plans or ordinances are not expected to occur as a result of
                 Sale 142, as existing onshore infrastructure is expected to be sufficient.
                     There is currently considerable local concern in the State of Louisiana about OCS waste onshore disposal
                 practices. If OCS drilling and production wastes cannot meet the U.S. Environmental Protection Agency's
                 NPDES effluent limitations or if these limitations require zero offshore discharge, offshore operational wastes
                 must be transported to shore for onshore disposal.
                     New proposed effluent limitations and their changes to current disposal practices are discussed in Section
                 IV.A.2.d.(5). It is expected that OCS waste resulting from Sale 142 leases would be properly disposed of in
                 approved landfills onshore. Onshore disposal of offshore waste products would be in accordance with USEPA!s
                 proposed effluent regulations (40 CFR 435), which list preferred options for each type of waste.
                     Issues identified in LCZMP include the following: general coastal use guidelines; levees; linear facilities
                 (pipelines); dredged spoil deposition; shoreline modifications, surface alteration, hydrologic and sediment
                 transport modifications; waste disposal; uses that result in the alteration of waters draining into coastal waters;
                 oil, gas, and other mineral activities; and air and water quality.
                     Assumptions fully discussed in Sections IV.A- and IV.C. indicate that proposed Sale 142 will generate the
                 impacting factors discussed below. These factors will affect coastal issues identified in Lie LCZMP.

                 Coastal Use Guidelines


                     Guidelines Applicable to All Uses (1. 1 through 1. 10)

                     General guidelines provide basic policy direction for the use of subsequent guidelines. Guidelines 1.1
                 through 1.3 apply to the determination of consistency for this proposal. Guideline 1.2, consistency with











                                                                                                                            IV-359

                 incorporated air and water quality statutes and standards, is also addressed later in this discussion. Guidelines
                 1.4 and 1.5, regarding taking of property or violations of the terms of a grant of lands or water bottoms, are
                 not applicable because no such activities are included or will result from this lease sale.
                     Guideline 1.6 lists the general factors that the permitting authority will use in evaluating whether a
                 proposed use is consistent with other guidelines. Nineteen factors are listed. Examples are as follows:

                         "a) type, nature and location of use."

                         "b)  elevation, soil and water conditions and flood and storm hazard characteristics of site."

                         "g)  economic need for use and extent of impacts of use on economy of locality."

                              existence of necessary infrastructure to support the use and public costs resulting from
                              use."

                         "l)  proximity to and extent of impacts on important natural features such as beaches, barrier
                              islands, tidal passes . . . ."

                         "in) extent to which regional, state and national interests are served . . .

                         "p) proximity to and extent of impacts on public lands or historic, recreational or cultural
                              resources."

                     Additionally, six of the factors deal with effects of the use. Much of the information cited above (e.g.,
                 factor b) concerns activities for which specific information is not available at the lease sale stage.
                     Guideline 1.7 lists 21 categories of adverse effects that potential land and water uses in the coastal zone
                 should avoid creating, to the maximum extent possible.
                     As previously indicated, no new support facilities are expected in Louisiana's coastal zone as a result of
                 this lease sale (EIS Base Case scenario). Transportation of equipment and materials to support offshore
                 operations is expected to use existing navigation channels through coastal areas. These operations would have
                 only minor incremental effects relative to existing facilities.
                     The primary factor of concern for sensitive coastal habitats is contact by accidental oil spills. An oil-spill
                 risk analysis, detailed information concerning oil spills and spill containment and cleanup methods, is included
                 in Section IV.C. Predictive results of a computer model run for the EIS analysis, described below and used
                 throughout the rest of this document, assume that no efforts are made to contain or clean up spills or otherwise
                 protect sensitive resources from spill contact.
                     The mean number of spills over 1,000 bbl estimated to occur in the Central Gulf from Sale 142 is 0.18.
                 This EIS indicates that the sale could result in an approximate 2 percent probability of accidental spills greater
                 than or equal to 1,000 bbI occurring and contacting the coast of Louisiana within 10 days. Further, oil spills
                 greater than or equal to 1,000 bbI that may occur as a result of an accident during exploration or development
                 activities are not assumed to contact coastal habitats proximal to the sale area.
                     There is no direct relationship between offshore oil and gas activities and wetlands destruction. Therefore,
                 it is impossible to determine direct wetland impacts from a specific offshore activity. The MMS has no
                 jurisdictional or permitting involvement in any possible coastal wetlands mitigation activities in the State of
                 Louisiana. Coastal zone impacts are documented by the State in its Coastal Permitting Process.
                     Turner and Cahoon's (1987) estimates of OCS-related wetlands loss attributed a large amount of OCS-
                 related wetland losses to the indirect effects of canals. They estimated the indirect impacts from OCS-related
                 canals to account for 4 to 13 percent of the total amount of wetland loss that occurred in coastal Louisiana
                 between 1955/1956 and 1978. This range was determined by dividing the length of OCS-related canal spoil
                 banks by the length of all spoil banks in the coast, and multiplying this proportion times the total amount of
                 wetlands loss that could not be accounted for in the direct losses attributable to canal dredging and











                 IV-360

                 urban/commercial/agricultural development. The MMS does not consider this indirect impact determination
                 acceptable for several reasons.
                     First, as stated by Turner and Cahoon, OCS spoil banks may have been overestimated in their calculations
                 because-OCS canals and spoil banks tend to be larger and thus more visible on remote-sensing imagery than
                 other canals and spoil banks. Additionally, Turner and Cahoon did not subtract losses related to sediment
                 deprivation and rapid coastal submergence (factors many coastal researchers consider to be the most important
                 causes of wetlands loss) from total wetlands loss before multiplying the total loss number by the proportion of
                 OCS spoil banks.     They, therefore, incorrectly attributed losses caused by sediment deprivation and
                 submergence to the indirect impacts of canals. Finally, Turner and Cahoon did not incorporate the body of
                 data generated by the study, much of which was relevant to the evaluation of indirect impacts, into their
                 method of determining OCS indirect impacts.
                     To conclude, MMS considers the Turner and Cahoon estimates to be no more reliable or better supported
                 by field data than any other attempts in the past to quantify the effects of indirect canal impacts.
                     Many researchers believe that restoring sediment to the wetlands would solve much of the land loss
                 problem and even result in a significant wetlands gain (Cleveland et al., 1981).
                     The MMS has funded another study to determine the effects of pipeline and navigation channels on barrier
                 beach erosion along the Gulf coast from Texas to the Florida panhandle (Wicker et al., 1989). This study
                 showed zero-to-minimal impacts from OCS activities on the Louisiana barrier coast.
                     The MMS is currently funding additional research to evaluate the effects of backfilling OCS channels to
                 restore living resources and enhance fisheries habitat The MMS has also funded a major study of the effects
                 of marsh management practices on wetlands (Cahoon and Groat, 1990).
                     No new nearshore pipelines are expected to be emplaced nor are new channels expected to be dredged.
                 Maintenance dredging in existing navigation channels in Louisiana could adversely affect wetlands if the
                 dredged material is disposed of in continuous spoil banks. New OCS-related pipeline and navigation channel
                 projects in coastal Louisiana will occur much more infrequently than in the past because the network currently
                 in place is adequate to accommodate oil and gas production from future resource development. One channel
                 in the Port Fourchon area will be deepened to accommodate larger vessels. The potential contribution of
                 support activities during exploration and/or production on these offshore leases, as compared to an navigation
                 use of channels, is likely to be very small and will be subject to later State consistency certification review.
                     The northern Gulf coastal zone is one of the major recreational regions of the United States, particularly
                 in connection with marine fishing and beach-related activities. Marine debris lost from operations associated
                 with drilling and production offshore may occur from time-to-time; however, the effect of intermittent washup
                 of debris on the recreational use of Louisiana beaches should be low. The regulations at 30 CFR 250.40
                 require that offshore operators handle, control, mark, and dispose of containers, equipmen@ and solid waste
                 through stringent marking, equipment handling, and storage requirements. The MMS inspectors check for
                 compliance with regulations during daily offshore inspections. Failure to comply with regulations leads to
                 official warnings to take corrective action or, if warranted, to cease operations.
                     Deliberate disposal of any solid waste or garbage items anywhere in the marine environment is strictly
                 prohibited under existing MMS, USEPA, and Coast Guard regulations. Because of increased concern over
                 the prevalence and effects of persistent marine debris, both offshore and on coastal beaches, MMS issued a
                 special advisory (NTL 86-11) in 1986 strongly encouraging the oil and gas industry to take special educational,
                 operational, and awareness measures to reduce or eliminate the their contributions to marine debris in the Gulf
                 of Mexico. Annex V of the International Convention for the Prevention of Pollution from 'Ships, also known
                 as the MARPOL Protocol, prohibits the dumping of all plastic wastes, including plastic packaging materials and
                 fishing gear, from all ships at sea. The MMS has established a policy that requires submission, for approval,
                 of detailed plans for the disposal of all produced solids accumulated as a result of OCS activities (LTL dated
                 November 20, 1990).
                     From information collected at beach cleanups and during marine debris surveys, it has been estimated that
                 existing offshore oil and gas operations are responsible for 10-15 percent of the trash and debris adversely
                 affecting the Gulf's shorefront recreational beaches in the CPA. Recent Federal regulations (33 CFR 151)
                 stemming from MARPOL Annex V, as well as periodic MMS directives and information seminars on the debris
                 issue, should lead to better waste handling and less accidental loss of materials and personal items into the











                                                                                                                              IV-361

               marine environment from offshore oil and gas operations. Additionally, industry education and training
               emphasis on waste management, along with voluntary stewardship commitments by several major oil companies
               (the adoption of about 30 mi of Louisiana Gulf beaches and the reduction and recycling of waste materials
               generated offshore), will also be reflected in a positive way on Louisiana's beaches.
                   Activities on these offshore leases are not expected to have a significant effect on coastal fishery resources.
               In addition, the effects on fishery resources beyond the coastal zone are likely to be minimal. State review of
               consistency certifications of exploration and development and production plans will enable more detailed review
               of site-specific proposed activities as they relate to fisheries and fishing practices. Federal provisions concerning
               fisheries include the Fishermen's Contingency Fund, which requires payment to fishermen for documented
               damages, and 30 CFR 250.40, which requires the charting of subsea obstructions and the marking of equipment
               to establish liability for fisheries losses.
                   Biological stipulations proposed for the sale (discussed in Section II) contain special provisions for the
               regulation of discharges and the siting of facilities within offshore areas recognized as areas of exceptional
               biological productivity. These stipulations will help to protect fisheries resources. Studies of mud (NRC, 1983;
               Zingula, 1975; Menzie, 1983) and cutting discharges from offshore oil and gas operations show rapid dispersal
               by ocean currents with no long-term, significant biological effects.
                   An archaeological resource stipulation has been proposed that will require surveys for investigation and
               avoidance or protection of cultural resources on the OCS. The State Office of Historic Preservation will have
               opportunities to consult with MMS on protection of onshore historic resources, if development is proposed on
               any lease.
                   In addition, the lease sale may create new jobs and may generate other economic opportunities to the
               benefit of Louisiana and the Nation. An MMS-funded study (Laska, in progress) evaluates the effect of the
               downturn in the oil industry on the Gulf economy and investigates alternate uses of existing OCS infrastructure
               for economic development opportunities. Any change of existing social patterns in coastal Louisiana as a result
               of activities on these offshore leases is highly unlikely. The sale will result only in a continuation of existing
               facilities without notable alteration of social patterns because of currently unemployed and underemployed
               resources in the coastal zone. Jobs created as a result of the sale would likely reduce the amount of out-
               migration when compared to scenarios without the proposal. Economic considerations are also evaluated in
               the Secretarial Issue Document and the Decision Memorandum for this sale.
                   The cumulative effects of the proposed actions that relate to the LCZMP are addressed in Section IV.B.
               This evaluation meets the criteria of "cumulative" as used in Guideline 1.7 of the LCZMP because it projects
               all of the reasonably foreseeable effects of the sales, including exploratory drilling, platform installation, support
               vessel traffic, etc. A separate Cumulative Analysis required under NEPA considers a much broader scope of
               effects, including proposed Sale 142; subsequent OCS oil and gas sales that are considered reasonably
               foreseeable; prior OCS oil and gas sales; State oil and gas activity; crude oil imports by tankering; and all other
               major non-OCS activities and occurrences that may occur and affect a resource in question.
                   The proposed lease stipulations, MMS rules and regulations (including requirements for oil-spill
               contingency planning, use of blowout preventers, Best Available and Safest Technology, crew training, and
               other environmental safeguards), compliance with National Pollutant Discharge Elimination System (NPDES)
               permits and standards, and other available Federal regulatory mechanisms will effectively mitigate the possible
               effects of oil and gas activities. Should new onshore facilities be needed for development of these leases, they
               will be subject to State regulations and separate permits, including State consistency certification review.
                   Guideline 1.8 defines "to the maximum extent possible," a phrase that modifies many of the guidelines.
               A use or activity will be consistent, although not fully complying with a standard, if it meets several criteria
               relating to public benefit; or lacks feasible alternatives or serves important local, State or national interests;
               or is dependent on water. Federal regulations at 15 CFR 930.32 also defte the term "maximum extent
               practicable" and recognizes there will be circumstances where full consistency with a State program is not
               possible.
                   Federal offshore oil and gas leasing serves an important national interest because future energy production
               resulting from OCS development will help to reduce the Nation's reliance on foreign imports. The LCZMP,
               through this policy, recognizes the relative importance of a national interest criterion in this guideline to the










                 IV-362

                 extent that, even if a use or activity does not fully comply with a standard, it is consistent 'to the maximum
                 extent possible."
                      Guideline 1.9 requires that uses be, to the maximum extent practicable, designed and carded out to permit
                 multiple uses and to avoid use conflict. This lease sale, as pointed out earlier, may eventually result in an
                 outcome that allows for multiple use and avoids use conflict. Offshore conflicts would be limited in scope
                 because certain multiple-use areas are off limits to oil and gas activities (e.g., shipping fairways and selected
                 military warning areas). Other multiple uses, such as boating and fishing, would result in only limited conflicts
                 because of the small areal extent of space used by oil and gas operations.

                      Guidelines for Levees (2. 1 through 2 6)

                      The guidelines for levees apply to those constructed in the coastal zone. No levee construction activities
                 are expected to occur in Louisiana as a result of this lease sale. If any such activities were to be proposed in
                 Louisiana, the State would have opportunities to review such proposals through consistency certifications of
                 Corps of Engineers permits.

                      Guidelines for Linear Facilities (3.1 through 3.16)

                      Guidelines for linear facilities contain standards for State permitting of siting and installation of pipelines
                 located in onshore or nearshore coastal areas. Most of the production from this lease sale is projected to be
                 sent through existing trunklines for transportation to existing onshore processing facilities in the central and
                 western Gulf coastal areas. No new pipeline landfalls or onshore pipeline projects are anticipated. There may
                 be a small contribution (less than 5%) of barge and tanker operations transporting oil to offloading facilities
                 located at onshore terminals in Louisiana. Any new pipeline construction crossing submerged State lands must
                 be consistent with applicable State regulatory policies to ensure safety in construction and operation.
                      The Gulf Regional Technical Working Group (RTWG), which is an advisory committee, develops
                 transportation plans for OCS areas. One of the purposes of this coordinated planning effort is to establish
                 corridors for consolidating multiple pipelines, an effort aimed at minimizing seafloor obstructions and adverse
                 environmental effects. These and other efforts of RTWG, which include representatives from the State of
                 Louisiana, help to ensure effective coordination on postlease pipeline-related activities.

                      Guidelines for Dredged Spoil Deposition (4.1 through 4.7)

                      Guidelines apply to disposal of dredged material in the coastal zone. No new trunklines are expected from
                 projected production on these offshore leases. No dredging solely related to activities taking place on Sale 142
                 leases is projected to occur. Maintenance dredging of existing canals through barrier passes to accommodate
                 vessel traffic to support the proposed action could alter littoral dynamics in the vicinity of the channel and
                 could affect erosion and deposition patterns. Field studies, however, have not substantiated that dredging has
                 resulted in coastal barrier erosion. In fact, the disposal of dredged material into the coastal, littoral transport
                 system can be used to nourish sediment-starved and eroding coastal barriers. One canal in the Port Fourchon
                 area may be deepened. Should any future exploration or development of Sale 142 leases involve disposal of
                 dredged material, the State will have an opportunity to review such activities in its consistency certification
                 process.

                      Guidelines for Shoreline Modifications (5.1 through 5.9)

                      These guidelines apply to shoreline modification and protection structures and to harbor structures. No
                 such activities or facilities are expected to result from exploration or development activities on Sale 142 leases.
                 Given the availability of existing harbor space, no new shoreline modifications are likely to be needed. If
                 unforeseen postlease support facilities are proposed, the State will have opportunities to conduct consistency
                 certification reviews.











                                                                                                                           IV-363

                    Guidelines for Surface Alteration (6.1 through 6.14)

                    Guidelines for surface alterations contain two general guidelines (6.1 and 6.5) regarding development in
                the coastal zone.
                    Guideline 6.1 encourages industrial, commercial, and other development in suitable areas of the coastal
                zone. Suitable areas are defined as (a) to the maximum extent practicable, lands 5 ft or more above sea level
                or fast lands; or (b) those lands where suitable foundation conditions and minimum flood and storm damage
                risk are already developed or where development would not unreasonably endanger public safety; (c) areas
                having adequate infrastructure; or (d) having a tradition of similar use. Guideline 6.5 states that coastal
                water-dependent uses shall be given special consideration in permitting because of the reduced choice of
                alternatives. Most major postlease activities or facilities in the coastal zone are coastal water-dependent and
                industrial in nature. The consistency certifications contained in exploration and development and production
                plans will enable the State to review these activities for consistency.
                    Other surface alteration guidelines (6.2, 6.4, 6.6 through 6.10, and 6.12 through 6.14) are similar in scope
                to guidelines affecting pipeline siting and construction. They address siting, construction techniques, design
                characteristics aimed at avoiding natural features, and alteration of critical and biological resources.
                    As indicated earlier, no new support facilities are hypothesized to occur in Louisiana's coastal zone.
                However, should they be needed, the State will have opportunities to conduct consistency certification reviews
                and issue separate permits.

                    Guidelines for Hydrologic and Sediment Ransport Modifications (7 1 through 7 9)

                    Hydrologic and sediment transport modification guidelines apply to water control structures and marsh-
                building schemes in the coastal zone. Although these guidelines are not applicable to this lease sale per se,
                because no such structures or activities are included or are likely to result, should a lessee propose development
                activities involving such modifications, he must obtain an affirmative State consistency certification review and
                other State permits.

                    Guidelines for the Disposal of Wastes (8.1 through &9)

                    The guidelines for waste disposal apply to the location and operation of waste disposal facilities in the
                coastal zone and the generation, transportation, treatment, storage, and disposal of hazardous wastes. The
                requirements and standards in NPDES permits (40 CFR 122) and the regulatory requirements of MMS (30
                CFR 250.42) protect the quality of offshore waters. A variety of solid wastes are brought onshore for disposal
                at nonhazardous oil-field waste (NOW) sites and landfills. Oil and gas waste are exempt from Federal
                hazardous waste regulations. Because of recent State regulations (LAC 33:IX.708, effective March 20, 1991),
                impacts from OCS produced waters should be minimized (Section IV.A.Ic.(4)(a)). Current levels of routine
                point source and nonpoint source discharges are expected to continue because no new infrastructure is
                projected (Section IV.A.), and no new sources are expected from this proposal.
                    The oil and gas industry is the dominant supporter and participant in the Louisiana beach adoption and
                cleanup program. Over three-fourths of Louisiana's adopted beaches and cleanup volunteers are directly
                associated with the oil companies (Amoco, Chevron, Conoco, CNG, Exxon, Fina, Kerr-McGee, Koch, LL&E,
                Mobil, Shell, and Texaco). Furthermore, a special subcommittee of the Offshore Operators (Waste Handling
                & Recycling) has been established to develop and to encourage industrywide strategies and procedures that
                will reduce and improve the handling of waste materials generated offshore. For example, many offshore oil
                and gas operators have eliminated the use of styrofoam drinking containers and food packaging materials and
                have increased the use of bulk containers and compactors. Some companies are testing and implementing
                comprehensive recycling projects for reusable waste generated offshore. Several ongoing surveys supported
                and conducted by government, industry, academia, and environmental groups will help monitor industry's
                record in handling, controlling, and disposing of solid waste and other items associated with offshore operations.
                The MMS has taken a leading role in establishing the Take Pride Gulf Wide campaign working through the










                 IV-364

                 Gulf of Mexico Program, in which all Gulf user groups are encouraged through education and participation
                 in stewardship projects to become part of the solution instead of the problem.

                     Guidelines for Uses that Result in the Alteration of Waters Draining into Coastal Waters (9-1 through 9.3)

                     The guidelines apply to water management programs and are not applicable to this lease sale because no
                 such programs are included in or will result from this sale.

                     Guidelines for Oi4 Gas, and Other Mineral Activities (10. 1 throughia14)

                     The guidelines for oil, gas, and other mineral activities address surveying, drilling, or refining activities in
                 the coastal zone and are not applicable to exploration, development, and production activities on the OCS that
                 may occur on Sale 142 leases.
                     However, some of the guidelines (10.3, 10.4, 10.9 through 10.12, and 10.14) could be applicable to the
                 extent that these are defined as associated exploration, development, or production facilides or activities.
                 Those guidelines that would apply to onshore facility development (10.3, 10.4, 10.9 and 10. 10) are modified by
                 the terms "to the maximum extent practicable" or "best practical techniques." The applicable requirement is
                 for exploration and production facilities to be "designed and constructed using best practical techniques to
                 minimize adverse environmental impacts" to the coastal zone.
                     The EIS analysis indicates that projected adverse impacts of hypothetical, future offshore exploration,
                 development, and production operations on the Louisiana coastal zone are likely to be of a very low level.
                 Further, all OCS exploration, development, and production activities and/or associated facilities will be subject
                 to State consistency certification review if and when they are proposed.
                     Guideline 10.11 establishes an absolute requirement for environmental protection and emergency or
                 contingency plans for all mineral operations in the coastal zone. Sale 142, however, will not result in any oil,
                 gas, or other mineral operations in the State's coastal area, nor is there any expectation of new or expanded
                 shore bases or refining facilities. Existing Federal regulations (30 CFR 250.33, 250.34, and 250.42) establish
                 similar but more site-specific requirements for approval of such operations on OCS leases. An oil-spill
                 contingency plan (OSCP) is one such requirement The OSCP's must be submitted for approval with, or prior
                 to, an exploration or development plan. The OSCP, outlining the availability of spill containment and cleanup
                 equipment and trained personneL is reviewed and updated annually. It must ensure that full response
                 capability could be committed during an oil-spill emergency. This commitment would include specifications
                 for appropriate equipment and materials, their availability, and the time needed for deployment. The plan
                 must also include provisions for varying degrees of response effort, depending on the severity of a spill.
                     All OCS exploration or development and production plans will be subject to State consistency certification
                 review and must describe how the operator proposes to comply with the environmental protection requirements
                 of pertinent Federal statutory and regulatory requirements.
                     Guideline 10.12 prohibits the use of chemical agents on coastal zone oil spills without prior approval of
                 the On-Scene Coordinator, in consultation with Louisiana and the USEPA, pursuant to the National Oil and
                 Hazardous Substances Pollution Contingency Plan (40 CFR 112). This guideline duplicates similar Federal
                 requirements.
                     Finally, Guidelines 10. 13 and 10. 14 address the restoration of mineral exploration or prod uction sites and
                 the avoidance of creating underwater obstructions in the coastal zone. No mineral exploration or production
                 activities will be proposed in the coastal zone of Louisiana. However, on the OCS, offshore sites are subject
                 to the Site Clearance requirements of MMS under NTL 90-01. Requirements established under this NTL
                 ensure that any object (e.g., wellheads, platforms, etc.) installed on an OCS lease is properly removed and the
                 site cleared so as not to conflict with other uses of the OCS.











                                                                                                                         IV-365


               State Air and Water Quality Regulatory Provisions

                   Air Quality (Louisiana R.S. 30.1068,1081-1087)

                   State policy on air quality incorporated into the LCZMP is applicable to State onshore areas.
                   Section 5(a)(8) of the OCSLA grants DOI exclusive authority and responsibility to prescribe regulations
               requiring offshore sources of air emissions to be consistent with national ambient air quality standards to the
               extent offshore activities significantly affect the onshore air quality. Thus, the Department's regulations are
               the applicable air pollution control requirements of the LCZMP under Section 307(f) of CZMA for OCS
               emissions.
                   Oil and gas development and production activities on the OCS are required to meet Department air quality
               regulations (30 CFR 250.44, 250.45, and 250.46). These regulations require offshore lessees to determine
               through modeling whether their air emissions would result in onshore pollutant concentrations above
               Department-specified significance levels. If these levels are projected to be exceeded in an area where
               concentrations already exceed air quality standards, the lessee will be required to control fully or offset its
               emissions so that there would be no effect onshore. If the significance levels are exceeded in areas at present
               in compliance with standards, the lessee will be required to employ best available control technology (BACr).
               If predicted onshore concentrations still exceed a standard for the prevention of significant deterioration,
               measures beyond BACT will be required.
                   Because of trends in leasing farther offshore, the levels of activity adjacent to Louisiana parishes are not
               expected to be large as a result of this sale. This trend toward development farther offshore will result in
               greater dispersion of emissions, Le., a very low level of impact.
                   Section 328 of the Clean Air Act (42 U.S.C. 7401-7642, as amended) directed DOI to conduct a research
               study examining the impacts from activities on the OCS adjacent to Texas, Louisiana, Mississippi, and Alabama
               on areas that fail to meet the Federal air quality standards for ozone (40 CFR 50). The MMS has been
               consulting with USEPA, the States, and others to design a study that will start in 1992. The study will have
               the following components: (1) a characterization of meteorological regimes associated with ozone episodes in
               nonattainment areas, (2) an evaluation of meteorological and air quality data from ozone modeling, (3)
               application of photochemical modeling to estimate impacts from OCS activities on ozone nonattainment areas,
               (4) a limited field program to collect meteorological data in offshore and coastal areas for future modeling
               applications, and (5) a set of recommendations for future monitoring and modeling activities.
                   In addition to the air quality study being planned in the Gulf of Mexico, MMS and USEPA have been
               consulting on the possibility of conducting a preliminary ozone study using the ROM model. A complete set
               of results and impact assessment will be made when the 3-year study is completed. The EIS (Sections
               IV.D. I.a.(4) and IV.D.2.a.(4)) reflects MMS's needs and commitment to gather information on ozone formation
               and dispersion from OCS emissions.
                   This EIS analysis (Section IV.A.2.d.(6)) indicates that offshore air emissions are not likely to cause
               degradation of onshore air quality and are not likely to have any significant effect on nonattainment or
               Prevention of Significant Deterioration Class I areas. Actual measures ordered by MMS will be determined
               after reviewing additional site-specific studies submitted by lessees, along with their exploration and
               development and production plans for approval.

                   Water Quality (Louisiana RS. 30.1068, 1091-1096; 38:216)

                   The Federal Water Pollution Control Act (FWPCA) (33 U.S.C. 1251 et. seq., as amended) vests exclusive
               regulatory authority over discharges on the high seas to USEPA. Under Section 307(f) of CZMA, the
               applicable water pollution control requirements are those promulgated pursuant to the FWPCA. Inasmuch
               as Louisiana does not have USEPA approval to administer NPDES permits for coastal waters pursuant to that
               Act, USEPA!s own regulations are the applicable water pollution control requirement of the LCZMP.
                   All OCS exploratory operations involving discharges will be conducted in compliance with NPDES permits
               (40 CFR 122) issued by the USEPA. Operational discharges (drilling muds and cuttings, produced waters, deck
               drainage, and sanitary and domestic wastes) may degrade water quality somewhat, changing measures from










                  IV-366

                  background levels, but with little effect to benthic and pelagic organisms in the water column, and then only
                  very close to the source. (No oil-based drilling muds are allowed to be discharged into Federal waters.) The
                  MMS established a policy that requires the submission, for approval, of detailed plans for the disposal of an
                  produced solids accumulated as a result of OCS activities (LTL dated November 20, 1990). The impact to
                  marine waters from off and gas discharge activities on these offshore leases is considered to be low.
                      The NCP requires that the U.S. Coast Guard's OSC obtain the concurrence of the USEFIA representative
                  to the RRT and, as appropriate, the concurrence of the RRT representatives from the states having jurisdiction
                  over the navigable waters threatened by the release or discharge; and that, when practicable, the OSC consult
                  with the DOC and DOI natural resource trustees prior to authorizing the use of a chemical agent. Approved
                  chemical agents must be listed on the NCP Product Schedule. The OSC is not required to obtain the
                  aforementioned concurrence when, in the judgment of the OSC, the use of a chemical agent is necessary to
                  prevent or reduce substantially a hazard to human life. Consistent with this, a Memorandum of Understanding,
                  dated August 16, 1971, between the Department of the Interior and the Department of Transportation allows
                  MMS the authority to grant OCS operators approval to use chemical agents within a 503-m radius of the
                  source of pollution to abate the source of pollution only when such agents are deemed necessary as a measure
                  for the safety of personnel and operations.
                      Several activities may adversely affect marine water quality on the OCS and, thus, potentially the coastal
                  waters. Drilling operations, platform and pipeline installation, and platform removal operations may resuspend
                  bottom sediments. Some water quality parameters may change from background levels with little effect to the
                  benthic and pelagic life nearby, and then only very close to the source. The impact from these activities to
                  marine water quality above the OCS is considered to be low.
                      Existing onshore infrastructure and associated coastal activities in support of oil and gas activities on these
                  leases have the potential to contribute to a low extent to the degradation of regional coastal and nearshore
                  water quality. The barge trips and service-vessel trips expected to occur in Louisiana (Base Case) may further
                  impact water quality by routine release of bilge and ballast waters (estimated at 2,000 liters per day from
                  service vessels) and low-level antifouling paints. Each activity provides only a small measure of continuous
                  contamination. Discharge locations are widespread. Negligible saltwater intrusion could occur from
                  maintenance dredging or deepening of existing navigation channels for large vessel requirements. Such
                  dredging is likely to result in short-term, low-level impacts to the surrounding waters. All dredging would be
                  pursuant to COE permits (33 CFR 330) or be conducted by COE itself, and would be subJect to consistency
                  determination from that agency.
                      No new service bases are expected to be constructed in Louisiana to support activities from Sale 142 leases.
                  Therefore, no additional point or nonpoint sources of pollution are likely to result. Environmental impacts
                  associated with normal service base use include runoff and spillage of fuels and chemicals from the facility,
                  discharges from supply and crew boats, channel bank erosion from vessel traffic, and disturbance of bottom
                  sediments from maintenance dredging. All new onshore facilities must be proposed in exploration or
                  development and production plans, which the State will review for consistency certification. Separate State
                  permits will also be necessary.
                      Accidental oil spills on the OCS may degrade water quality somewhat, changing measurements from
                  background levels, but with little effect to the pelagic and benthic organisms in the water column and then only
                  in a very limited area close to the source. Accidental oil spills may contribute to a local, low-level impact near
                  some terminals and service bases where the spills have a more probable occurrence; regionally, adverse impacts
                  from such accidental oil spills are assumed to be very low.
                      In both offshore and coastal areas, authorities cited above are sufficient to ensure that future operations
                  related to the proposed lease sale will not adversely affect water quality.

                  (3) Mississippi

                      The Sale 142 analysis area closest to the submerged lands of the State of Mississippi is Central coastal Area
                  C-3, which extends offshore from the State 3-mi line. The Mississippi coastal counties are Hancock, Harrison,
                  and Jackson.











                                                                                                                           IV-367

                    According to NOAA, there are no approved local coastal management plans for the State of MississippL
                The Southern Mississippi Planning and Development District serves in an advisory capacity to the State coastal
                agencies. Conflicts with Mississippi local land use ordinances are not expected to occur as a result of Sale 142,
                as existing onshore infrastructure is expected to be sufficient
                    Issues identified in the Mississippi Coastal Program (MCP) include the following: coastal wetlands; coastal
                industrial development; special management areas; air and water pollution; use of coastal water resources;
                scenic, historical and cultural resources; and fisheries management.
                    Assumptions fully discussed in Sections IV.A.4. and 5. and IV.C. indicate that proposed Sale 142 will
                generate the impacting factors discussed below. These factors will affect coastal issues identified in the MCP.

                Coastal Wetlands and Coastal Industrial Development

                    Two relevant provisions of the MCP provide the following:

                        It is the policy of Mississippi "to favor the preservation of the natural state of the coastal
                        wetlands and to prevent the despoliation and destruction of them, except where a specific
                        alteration of specific coastal wetlands would serve higher public interest in compliance with
                        the public trust in which coastal wetlands are held" (Mississippi Code, Sec. 49-27-3). It is the
                        policy of Mississippi "to provide for reasonable industrial expansion in the coastal area and
                        to insure the efficient utilization of waterfront industrial sites so that suitable sites are
                        conserved for water dependent industry" (Mississippi Code, Sec. 57-15-6(l)(2)).

                Onshore Facilities


                    According to the Base Case scenario, no new service bases are expected to be located in coastal Subarea
                C-4, which includes portions of Mississippi's coastal zone. Onshore development would be subject to State
                regulation, but would generally be a permitted and encouraged use in the Industrial and Port Areas identified
                in the MCP. Should new onshore facilities be needed for development of leases, the facilities would be subject
                to State regulations and separate permits, including State consistency certification review. Such uses would
                generally be permitted and encouraged in the industrial and port areas identified in the MCP.

                Transportation Activities

                    The MMS estimates that most of the production from this lease sale will be transported by new pipelines
                to existing trunk lines for transportation to existing onshore processing facilities in Mississippi and other Gulf
                States. No new pipeline landfalls or onshore pipeline projects are anticipated as a result of the Base Case
                scenario. Any new pipeline construction must be consistent with applicable State regulatory policies to ensure
                safety in construction and operation. It must also have an affirmative consistency dertification review decision
                issued by the State.
                    The Gulf of Mexico RTWG, which was established to facilitate coordinated pipeline planning between the
                State and Federal agencies, would establish pipeline planning corridors to avoid adverse environmental effects.
                The operations of RTWG, which include representation from the State of Mississippi, will help to promote
                consistency with State wetlands management guidelines.

                Offshore Operations

                    A spill resulting from offshore oil and gas operations could affect Mississippi coastal wetlands. See Section
                IV.D.I.e.(2)(Louisiana) for a relevant discussion of wetlands impacts and OCS oil and gas operations).
                Offshore activities would be located away from coastal wetlands. However, the probability of an oil spill
                greater than or equal to 1,000 bbl actually occurring and contacting within 10 days these wetlands areas is low
                (less than 0.5%). This EIS indicates that, under the Base Case scenario, no spills greater than or equal to 1,000
                bbl are assumed to contact the Mississippi coast However, in the event of such occurrence, the requirements










                 IV-368

                 for oil-spill prevention, off-spill contingency planning and response, and the platform verification program
                 mitigate against the possibility of adverse effects on the environment. An oil-spill contingency plan (30 CFR
                 250.42) must contain assurances that a full-response capability exists for commitment in the event of a spill.
                 This plan includes specification of appropriate equipment and materials, their availability and deployment time,
                 and provisions for varying degrees of response effort, depending on the severity of a spiEL The platform
                 verification program (30 CFR 250.131, 250.132, and 250.133) ensures that offshore oil and gas structures are
                 designed, fabricated, and installed to prevent structural failure for the safe conduct of operatiDns. In addition,
                 the OCSLA requirement for use of best available and safest technologies (BAST) also helps to ensure
                 protection of coastal wetlands.
                     Transportation of equipment and materials to support offshore operations is expected to use existing
                 navigation channels through wetland areas. These operations would have only minor incremental effects
                 relative to existing activities.

                 Special Management Areas

                     The MCP provides for regulation of activities in three categories of Special Management Areas (SMA's).
                 One such category is designated Industrial and Port Areas; these include Port Bienville Industrial Park, Pass
                 Christian Industrial Park, Bayou Bernard Industrial Park, Pascagoula River Industrial Park, Bayou Casotte
                 Industrial Park, and the Moss Point Industrial Park. The State's policy on industrial and port areas is "to
                 provide for reasonable industrial expansion in the coastal area and to ensure the efficient utilization of
                 waterfront industrial sites so that suitable sites are conserved for water dependent industry" (Mississippi Code,
                 Sec. 57-15-6(l)(a)). The other SMA categories are Urban Waterfronts and Shorefront AccA-,ss Areas.
                     Among the SMA!s identified in the MCP, areas reserved for port and industrial development are most
                 relevant to these lease sales. Mississippi Code, Sec. 49-27-9, exempts water-dependent industry from the need
                 to secure a permit for erection of structures on sites designated as suitable for it. In terms of this lease sale,
                 no onshore development in Mississippi is hypothesized to result. Furthermore, any postlease onshore
                 development in the Mississippi coastal zone would be subject to the State regulations and consistency
                 certification review and concurrence.


                 Other Provisions Incorporated into the MCP

                     Certain regulatory provisions of the State program are not focused on a designated area basis. These
                 include authorities of the State Air and Water Pollution Control Law, authorities to allocate surface waters and
                 to control the use of groundwater, authorities concerning fisheries management, and authorities for protection
                 of historical and cultural resources.


                     Air and Water Pollution Control


                     The MCP provides that it is the policy of the State of Mississippi "to conserve the air and waters of the
                 state, and to protect, maintain and improve the quality thereof for public use, for the propagation of wildlife,
                 fish and aquatic life, and for domestic, agricultural, industrial, recreational and other legitimate beneficial uses"
                 (Ch. 1, Sec. 1.4, MCP).
                     State policy on air quality incorporated into the MCP is clearly applicable to State onshore areas. This
                 EIS analysis'indicates that activities related to Sale 142 leases (Section IV.A-2.d.(6)) will cause little degradation
                 of onshore air quality with no significant effect on nonattainment or Prevention of Significant Deterioration
                 Class I areas.
                     Section 5(a)(8) of the OCSLA grants DOI exclusive authority and responsibility to prescribe regulations
                 requiring offshore sources of air emissions to be consistent with the Clean Air Act national ambient air quality
                 standards to the extent offshore activities significantly affect the onshore air quality of a State. Thus, the
                 Department's regulations are the applicable air pollution control requirements of the MCP under Section 307(f)
                 of the CZMA for OCS emissions.










                                                                                                                         IV-369

                   OR and gas development and production activities on the OCS are required to meet Department air quality
               regulations (30 CFR 250.44, 250.45, and 250.46). The Department regulations require offshore lessees to
               determine through modeling whether their air emissions would result in onshore pollutant concentrations above
               Department-specified significance levels. If these levels are projected to be exceeded in an area where
               concentrations already exceed air quality standards, the lessee will be required to control fully or offset its
               emissions so that there would be no effect onshore. If the significance levels are exceeded in areas at present
               in compliance with standards, the lessee will be required to employ best available control technology (BACT).
               If predicted onshore concentrations still exceed a standard for the prevention of significant deterioration,
               measures beyond BACT will be required.
                   Section 328 of the Clean Air Act (42 U.S.C. 7401-7642, as amended) directed DOI to conduct a research
               study examining the impacts from activities on the OCS adjacent to Texas, LA)uisiana, Mississippi, and Alabama,
               on areas that fail to meet the Federal air quality standards for ozone (40 CFR 50). The MMS has been
               consulting with USEPA, the States, and others to design a study that will start in 1992. The study will have
               the following components: (1) a characterization of meteorological regimes associated with ozone episodes in
               nonattainment areas, (2) an evaluation of meteorological and air quality data from ozone modeling, (3)
               application of photochemical modeling to estimate impacts from OCS activities on ozone nonattainment areas,
               (4) a limited field program to collect meteorological data in offshore and coastal areas for future modeling
               applications, and (5) a set of recommendations for future monitoring and modeling activities.
                   In addition to the air quality study being planned in Gulf of Mexico, MMS and USEPA have been
               consulting on the possibility of conducting a preliminary ozone study using the ROM model. A complete set
               of results and impact assessment will be made when the 3-year study is completed. The EIS (Sections
               IV.D.I.a.(4) and IV.D.2.a.(4)) reflects MMS's needs and commitment to gather informationon ozone formation
               and dispersion from OCS emissions.
                   Each offshore facility is reviewed individually to determine if its emissions will cause a significant effect
               onshore. Further controls may be required if several facilities combine to create a significant effect. Actual
               measures ordered by the Department will be determined after additional site-specific studies by lessees and
               submission of operational plans for approval.
                   The Clean Water Act (33 U.S.C. 1251 et. seq., as amended) vests exclusive regulatory authority over
               discharges on the high seas in USEPA. Under Section 307(f) of the CZMA, USEPA regulations concerning
               water pollution control are the applicable water pollution control requirements of the MCP for OCS discharges.
                   The NCP requires that the U.S. Coast Guard's OSC obtain the concurrence of the USEPA representative
               to the RRT and, as appropriate, the concurrence of the RRT representatives from the states having jurisdiction
               over the navigable waters threatened by the release or discharge; and that, when practicable, the OSC consult
               with the DOC and DOI natural resource trustees prior to authorizing the use of a chemical agent. Approved
               chemical agents must be listed on the NCP Product Schedule. The OSC is not required to obtain the
               aforementioned concurrence when, in the judgement of the OSC, the use of a chemical agent is necessary to
               prevent or reduce substantiallya hazard to human life. Consistent with this, a Memorandum of Understanding
               dated August 16, 1971, between the Department of the Interior and the Department of Transportation allows
               MMS the authority to grant OCS operators approval to use chemical agents within a 500-m radius of the
               source of pollution to abate the source of pollution only when such agents are deemed necessary as a measure
               for the safety of personnel and operations.
                   The MMS established a policy that requires the submission, for approval, of detailed plans for the disposal
               of all produced solids accumulated as a result of OCS activities (LTL dated November 20, 1990). Discharges
               within State waters are regulated by the NPDES permit system (40 CFR 122) administered by the State of
               Mississippi pursuant to delegation by USEPA.
                   No new service bases will be constructed in Mississippi according to the Base Case scenario. Therefore,
               no additional point source and nonpoint sources of pollution win be created.
                   In both offshore and coastal areas, authorities cited above are sufficient to ensure that future operations
               related to the proposed lease sales will not adversely affect water quality.










                 IV-370

                     Use of Coastal Water Resources

                     It is the policy of the State of Mississippi "to put to beneficial use to the fullest extent of which they are
                 capable the water resources of the state, and to prevent the waste, unreasonable use, or unreasonable method
                 of use of water" (Ch. 1, Sec. 1.5, MCP).
                     Development on the Mississippi OCS will make minimal demands on freshwater supplies. Typically, to
                 about 1,000 ft, only seawater is used in the Gulf for drilling an offshore well; between 1,000 and 6,000 ft, only
                 seawater gel mud is used; at greater depths, a lignosulfonate mud is substituted. Freshwater supplies are
                 required, however, for domestic uses of personnel working on off-shore platforms. No new service bases would
                 be constructed; instead, freshwater would be drawn from surface or groundwater sources at existing service
                 bases in Mississippi or other Gulf states, depending upon the proximity of support facilities. The quantity of
                 potable water needed for offshore operations can be significant in water shortage areas but should be
                 insignificant in an area such as coastal Mississippi. Activities on Sale 142 leases are not likely to cause waste,
                 unreasonable use, or unreasonable method of use of water.

                     Scenic, Historica4 and Cultural Resources

                     It is the policy of the State of Mississippi "to preserve the state's historical and archaeological resources,
                 to prevent their destruction, and to enhance these resources wherever possible" (Ch. 1, Sec. 1.6, MCP).
                 Further, it is the policy of the State "to encourage the preservation of natural scenic qualifies in the coastal
                 area" (Mississippi Code, Sec. 57-15-6(l)(d)).
                     The MCP establishes policies for protecting scenic, historic, and cultural resources. An archaeological
                 resource stipulation has been proposed that will require surveys for investigation and avoidance or protection
                 of cultural resources on the OCS. The State Office of Historic Preservation will have opportunities to consult
                 with MMS on protection of onshore historic resources, if development is proposed on any lease. No major
                 spill is assumed to contact the coast of Mississippi as a result of this lease sale.
                     Marine debris lost from OCS operations associated with drilling and production throughout the Central
                 Gulf over the lease life may occur from time to time, but the effect of intermittent washup of debris on the
                 recreational use of Mississippi beaches should be low. The regulations at 30 CFR 250.40 require that offshore
                 operators handle, control, mark, and dispose of containers, equipment, and solid waste through stringent
                 marking, equipment handling, and storage requirements. The MMS inspectors check for compliance with
                 regulations during daily offshore inspections. Failure to comply with regulations leads to official warnings to
                 take corrective action or, if warranted, to cease operations.
                     From information collected at beach cleanups and during marine debris surveys, it has been estimated that
                 existing offshore oil and gas operations are responsible for 10-15 percent of the trash and debris adversely
                 affecting the Gulfs shorefront recreational beaches in the CPA. Recent Federal regulations (33 CFR 151)
                 stemming from MARPOL Annex V, as well as periodic MMS directives and information seminars on the debris
                 issue, should lead to better waste handling and less accidental loss of materials and personal items into the
                 marine environment from offshore oil and gas operations. Additionally, industry education and training
                 emphasis on waste management along with voluntary stewardship commitments by several major oil companies
                 (the adoption of about 30 mi of Louisiana Gulf beaches and the reduction and recycling of waste materials
                 generated offshore) will also be reflected in a positive way on Mississippi's beaches.

                     Fisheries Management

                     It is the policy of the State "to protect, propagate and conserve the state's seafood and aquatic life in
                 connection with the revitalization of the seafood industry of the State of Mississippi" (Ch. 1, Sec. 1.3, MCP).
                     The Bureau of Marine Resources (BMR) is responsible for enforcement of the Mississippi fisheries code,
                 although the MCP reserves this topic for future development of specific coastal guidelines. Activities on these
                 offshore leases are not expected to have a significant effect on coastal fishery resources. In addition, the effects
                 on fishery resources beyond the coastal zone are likely to be minimal. Potential oil-spill effects on fishery
                 resources are minimal, according to this EIS. State review of consistency certifications of exploration and











                                                                                                                           IV-371

               development and production plans will enable more detailed review of site-specific proposed activities as they
               relate to fisheries and fishing practices. Federal provisions concerning fisheries include the Fishermen's
               Contingency Fund, which requires payment to fishermen for documented damages, and 30 CFR 250.40
               requirements, which require the charting of subsea obstructions and the marking of equipment to establish
               liability for fisheries losses and other pollution prevention measures.

               Consideration of National Interest in Siting of Energy Facilities

                   The MCP provides that it is the policy of the State of Mississippi "to consider the national interest involved
               in planning for and in the siting of facilities in the coastal area" (Mississippi Code, Sec. 57-15-6 (1)(C)).
               Chapter 7, Sec. 1, and Chapter 9, Sec. 7, of the MCP indicate that this policy is to apply to, although it is not
               limited to, the siting of energy facilities, including offshore oil and gas facilities.
                   Federal offshore oil and gas leasing serves the national interest because future energy production resulting
               from OCS development will help to reduce the Nation's reliance on foreign imports. In addition, the lease
               sales may create new jobs and may generate other economic opportunities to the benefit of the State of
               Mississippi and the Nation. The MCP, through this policy, recognizes the national interest involved in the
               development of coastal energy facilities that often result from OCS offshore exploration and development. As
               described in Section IV.A., this lease sale is not expected to result in construction of new onshore support
               facilities in the coastal areas of Mississippi.

               (4) Texas

                   The sale analysis area closest to the submerged lands of the State of Texas includes Western offshore
               Subareas W-1, W-2, and W-3, which extend offshore from the State's 3-marine league line.
                   The Texas Legislature has distributed authority for coastal resource management among 14 State agencies
               (Appendix III, Coastal Responsibilities of Texas State Agencies, Texas Coastal Management Plan, January
               1991). Conflicts with local land use goals or planning are not expected to occur as a result of Sale 142, as
               existing onshore infrastructure is expected to be sufficient
                   The Texas Coastal Management Plan (TCMP) (State-approved plan) includes the following coastal
               resource issues: coastal erosion/dune protection, beach access, wetlands loss and degradation, oil spills, marine
               debris, freshwater inflow, nonpoint-source pollution, and hazardous waste generation and disposal.
                   Based on assumptions fully discussed in Sections IV.A. and IV.C., the impacting factors generated by the
               proposed sale are discussed below. These factors will affect coastal issues identified in the TCMP.

               Coastal ErosionlDune Protection and Beach Access

                   No new support facilities, pipeline landfalls, or onshore pipeline projects are anticipated in Texas as the
               result of activities on offshore leases (Base Case). Several deep-water pipelines will be constructed on
               Matagorda Island along the Texas coast and towed into deep-water areas off Texas and Louisiana. No new
               channels are expected to be dredged. One channel in the Corpus Christi area (coastal Subarea W-1) will be
               deepened to 6.7 m (22 ft) to accommodate larger vessels. Transportation of equipment and materials to
               support offshore operations is expected to use existing navigation channels through coastal areas (Brazos
               Santiago Pass, Port Mansfield Cut, Matagorda Ship Channel, Yarborough Pass, Aransas Pass, Corpus Christi
               Ship Channel, Freeport Harbor Channel, Houston/Texas City/Galveston Ship Channels, and Sabine Pass Ship
               Channel). These operations would have only minor incremental effects relative to existing facilities. If any
               hypothesized, postlease onshore development were to occur in Texas, it would be subject to control by
               applicable State regulations. The Texas General Land Office is responsible for technical assistance and
               compliance under the Dune Protection Act and for implementation of the Texas Coastal Preserve Program
               with the Texas Parks and Wildlife Department. The Texas Attorney General's Office protects the public's
               beach access rights and can bring suit on behalf of other State agencies to enforce State laws.










                 IV-372

                 Wetlands Loss and Degradation

                     Wetlands and submersed grassbeds are essential to the biological productivity of the Texas coastal zone.
                 Given the availability of existing harbor space, no new shoreline modifications are likely to be needed.
                 Additionally, no pipelines are proposed to cross Texas lands. If any new onshore facilities are proposed for
                 development of offshore leases, potential effects to wetlands and submersed grassbeds in the State's coastal
                 zone will be subject to State regulatory review. The TCMP identifies the Texas Parks and Wildlife Department
                 as the State agency that would monitor and enforce a policy of no net loss of wetlands. The Texas Water
                 Commission and the General Land Office would also coordinate with them in this effort.
                     Coastal zone biological resources may be affected by off spills associated with offshore operations.
                 Prevention and containment and cleanup of oil spills are addressed through various Federal mitigation and
                 regulation measures (30 CFR 250.42). Such measures include MMS requirements for an off-spill contingency
                 plan, prevention, and response; the platform verification program; and the general OCSLAL requirement to
                 apply the best available and safest technologies (BAST). The MMS requires that off-spill contingency plans
                 ensure that a full-response capability exists for containment in the event of an oil spill, including specification
                 of appropriate equipment and materials, their availability and deployment time, and provisions for varying
                 degrees of response effort, depending on the severity of the spin. The USEPA!s development and
                 implementation of the National Oil and Hazardous Substances Pollution Contingency Plan (4-0 CFR 112) and
                 correlative regional plans are designed to provide a coordinated and integrated response by Federal and State
                 agencies to protect the environment from the damaging effects of accidental oil spills and poll ution discharges.
                     Maintenance dredging in existing navigation channels in Texas could adversely affect wetlands if the
                 dredged material were disposed of in continuous spoil banks. The potential contribution of support activities
                 during exploration and/or production on these offshore leases as compared to all navigation use of channels,
                 is likely to be very small and will be subject to later State regulatory review. The Texas Department of
                 Highways and Public Transportation is responsible for acquiring easements and rights-of-way from the General
                 Land Office for channel expansion, relocation, or alteration.

                 Oil spills

                     The primary factor of concern for sensitive coastal habitats is contact by accidental oil spills. An ofl-spin
                 risk analysis, detailed information concerning oil spills and spill containment and cleanup methods, is included
                 in Section IV.C. Predictive results of a computer model run for the EIS analysis assume that no efforts are
                 made to contain or clean up spills or otherwise protect sensitive resources from spill contact.
                     The mean number of spills greater than or equal to 1,000 bbl estimated to occur in the Western Gulf from
                 proposed Sale 143 is 0.07. The EIS indicates that the sale could result in an estimated 0.05 percent probability
                 of one or more spills greater than or equal to 1,000 bbl occurring and contacting the coast of' Texas within 10
                 days.
                     An OSCP must be submitted for approval to MMS with, or prior to, an exploration or development plan
                 (30 CFR 250.33, 250.34, and 250.42). This OSCP, outlining the availability of spill containment and cleanup
                 equipment and trained personnel, is reviewed and updated annually. It must ensure that full-response
                 capability could be committed during an oil-spill emergency. This commitment would include specification for
                 appropriate equipment and materials, their availability, and the time needed for deployment. The plan must
                 also include provisions for varying degrees of response effort, depending on the 'severity of a spill.

                 Marine Debfis


                     The State of Texas Gulf coastal zone is one of the major recreational regions of the United States,
                 particularly in connection with marine fishing and beach-related activities. As indicated in Section IV.A.1.,
                 onshore support is expected to be provided from existing facilities. Marine debris lost from OCS operations
                 associated with drilling and production throughout the 35-year life of the lease may occur ftom time to time,
                 but the effect of intermittent washup of debris on the recreational use of Texas beaches should be low. The
                 regulations at 30 CFR 250.40 require that offshore operators handle, control, mark, and dispose of containers,











                                                                                                                           IV-373

                equipment, and solid waste through stringent marking, equipment handling, and storage requirements. The
                MMS inspectors check for compliance with regulations during daily offshore inspections. Failure to comply
                with regulations leads to official warnings to take corrective action or, if warranted, to cease operations.
                     Deliberate disposal of any solid waste or garbage items anywhere in the marine environment is strictly
                prohibited under existing MMS, USEPA, and Coast Guard regulations. Because of increased concern with the
                prevalence and effects of persistent marine debris both offshore and on coastal beaches, MMS issued a special
                advisory (NTL 86-11) in 1986 strongly encouraging the oil and gas industry to take special educational,
                operational, and awareness measures designed to reduce or eliminate their oil and gas industry's contributions
                to marine debris in the Gulf of Mexico. Annex V of the International Convention for the Prevention of
                Pollution from Ships, also known as the MARPOL Protocol, prohibits the dumping of all plastic wastes,
                including plastic packaging materials and fishing gear, from all ships at sea. The MMS has established a policy
                that requires the submission, for approval, of detailed plans for the disposal of all produced solids accumulated
                as a result of OCS activities (LTL dated November 20, 1990).
                     From information collected at beach cleanups and during marine debris surveys, it has been estimated that
                existing offshore off and gas operations are responsible for 10-15 percent of the trash and debris adversely
                affecting the Gulfs shorefront recreational beaches in the WPA. Recent Federal regulations (30 CFR 151)
                stemming from MARPOL Annex V, as well as periodic MMS directives and information seminars on the debris
                issue, should lead to better waste handling and less accidental loss of materials and personal items into the
                marine environment from offshore oil and gas operations. Additionally, industry education and training
                emphasis on waste management, along with voluntary stewardship commitments by several major off companies
                (the adoption of about 30 mi of Louisiana Gulf beaches and the reduction and recycling of waste materials
                generated offshore), will also be reflected in a positive way on Texas' beaches.

                Freshwater Inflow, Nonpoint Source Pollution, and Hazardous Waste Generation and Disposal

                     Potable water will be needed for domestic uses of personnel living on offshore platforms. However, the
                EIS estimates that no new service bases are likely to be constructed. The quantity of freshwater needed for
                offshore operations on these leases is likely to be insignificant in an area such as coastal Texas. The Texas
                Water Commission has the responsibility of overseeing surface water rights.
                     The quality of nearshore and offshore waters is protected through standards and requirements for NPDES
                permits (40 CFR 122), as mandated in the Federal Water Pollution Control Act (33 U.S.C. 1251 et. seq., as
                amended). Marine water quality is protected through regulatory requirements, monitoring, and enforcement
                actions of MMS and USEPA. Discharges in coastal areas are also subject to regulation by the Texas Water
                Commission and Texas Water Development Board.
                     No onshore water quality degradation is likely to occur in Texas as a result of activities on offshore leases
                because no new service bases are likely to be constructed in Texas (Base Case). Therefore, no additional point
                source and nonpoint sources of pollution are likely to result. In the unlikely event of any such occurrence,
                numerous Federal and State water pollution control regulations for mitigating any potential adverse effects
                exist.
                     Operational discharges (drilling muds and cuttings, produced waters, deck drainage, and sanitary and
                domestic wastes) may degrade water quality somewhat, changing measurements from background levels, but
                with little effect to benthic and pelagic organisms in the water column, and then only very close to the source.
                (No oil-based drilling muds are allowed to be discharged into Federal waters.) The impact to marine waters
                from oil and gas discharge activities on these offshore leases is considered to be low.
                     The NCP requires that the U.S. Coast Guard's OSC obtain the concurrence of the USEPA representative
                to the RRT and, as appropriate, the concurrence of the RRT representatives from the states having jurisdiction
                over the navigable waters threatened by the release or discharge; and that, when practicable, the OSC consult
                with the DOHC and DOI natural resource trustees prior to authorizing the use of a chemical agent. Approved
                chemical agents must be listed on the NCP Product Schedule. The OSC is not required to obtain the
                aforementioned concurrence when, in the judgement of the OSC, the use of a chemical agent is necessary to
                prevent or reduce substantiallya hazard to human life. Consistent with this, a Memorandum of Understanding,
                dated August 16, 1971, between the Department of the Interior and the Department of Transportation allows










                IV-374

                MMS the authority to grant OCS operators approval to use chemical agents within a 500-m radius of the
                source of pollution to abate the source of pollution only when such agents are deemed necessary as a measure
                for the safety of personnel and operations.
                     Several activities may adversely affect marine water quality on the OCS and, thus, potenlially the coastal
                waters. Drilling operations, platform and pipeline installation, and platform removal operations may resuspend
                bottom sediments. Some measures of water quality parameters may change from background levels with little
                effect to the benthic and pelagic life nearby, and then only very close to the source. The impact from these
                activities to marine water quality above the OCS is considered to be low. Existing onshoreinfrastructure and
                associated coastal activities in support of oil and gas activities on these leases have the potential to contribute
                to a low extent to the degradation of regional coastal and nearshore water quality. The barge tirips and service-
                vessel trips expected to occur in Texas (Base Case) may further impact water quality by the routine release of
                bilge and ballast waters (estimated at 2,000 liters per day from service vessels) and low-level antifouling paints.
                Each activity provides only a small measure of continuous contamination. Discharge locations are widespread.
                Negligible saltwater intrusion could occur from maintenance dredging of existing navigation channels. Such
                dredging is likely to result in short-term, low-level impacts to the surrounding waters.
                     The MMS has established a policy that requires the submission, for approval, of detailed plans for the
                disposal of all produced solids accumulated as a result of OCS activities (LTL dated November 20, 1990). The
                USEPA!s development and implementation of the National On and Hazardous Substances Pollution
                Contingency Plan and correlative regional plans are designed to provide a coordinated and integrated response
                by Federal and State agencies to protect the environment from the damaging effects of pollution discharges.
                Deliberate disposal of any solid waste or garbage items anywhere in the marine environment is strictly
                prohibited under existing MMS, USEPA, and Coast Guard regulations. The Texas Department of Health
                regulates programs to protect and promote public health, including those addressing the issue of solid waste.
                The Texas Water Commission regulates hazardous and industrial solid waste management.
                     In both offshore and coastal areas, authorities cited above are s  *ufficient to ensure that future operations
                related to the proposed lease sale will not adversely affect water quality.

                2. Proposed Western Gulf Sale 143

                     Proposed Western Gulf Sale 143 is scheduled to be held in August 1993. A detailed description of the
                proposal is included in Section I.A_ Alternatives to the proposed action and mitigating measures are described
                in Section II.B.
                     The analyses of impacts are based on scenarios for the Base Case, High Case, and 0imulative Case.
                These scenarios were formulated to provide sets of assumptions and'estimates on the amounts, locations, and
                timing for OCS exploration, development, and production operations and facilities, both offshore and onshore.
                These are estimates only and not predictions of what will happen as a result of holding this proposed sale. A
                detailed discussion of the development scenarios and major, related impact-producing factors is included in
                Sections IV.A_ and B. The four potential mitigating measures (Live Bottom (Pinnacle Trend), Topographic
                Features, Archaeological Resources, and Military Areas Stipulations) are considered part of the proposed
                action for analysis purposes.

                a. Alternative A - The Proposed Action

                     To facilitate the analysis, the Federal offshore area is divided into subareas. The WPA (mmprises three
                subareas (W-1, W-2, and W-3) and the coastal region is divided into two coastal subareas (W-1 and W-2).
                These subareas are delineated on Figure IV-1.










                                                                                                                          IV-375

                (1) Impacts on Sensitive Coastal Environments

                (a) Coastal Bai7ier Beaches

                    The major impact-producing factors associated with the proposed action that could affect barrier landforms
                include oil spills, pipeline emplacements, navigation canal dredging and maintenance dredging, and support
                infrastructure construction. These impact-producing factors have been discussed in Section IV.D.1.a.(1)(a) and
                are briefly summarized below.
                    Off spills can affect barrier beach stability if cleanup operations remove large quantities of sand, and if the
                oil contacts and damages sand dune vegetation. The Alvenus tanker spill of 1984 provides an example of the
                possible impacts from an oil spill greater than or equal to 1,000 bbl on coastal barriers in the WPA. The size
                of this spill (as much as 65,000 bbl) ranks it as one of the largest to have occurred in the Gulf. The greatest
                accumulation of oil from the spill occurred on middle and western Galveston Island. Road graders were used
                to move beached oil above the high tide zone. In all, 75,OW M3 of sand were removed from the beach (in
                comparison, Hurricane Alicia, a major Gulf storm, is estimated to have removed 750,000 M3 of sand). The
                beach profile changed slightly as a result of the sand removal project, but this change was undetectable after
                a few spring tides.
                    Pipeline landfalls across barrier islands have been identified as possible sites of weakness where an island
                could be breached during storm conditions or where accelerated erosion could thin the island. A recently
                completed, MMS-funded study, however, showed no minimal impacts to barrier beaches as a result of pipeline
                crossings (Wicker et al., 1989) in the coastal area affected by the proposed action.
                    The dredging of new navigation channels through barrier beaches or the stabilization and deepening of
                barrier inlets or passes could affect barrier landform stability by serving as a sediment sink, depriving beach
                areas downdrift from the channel or jetty of beach sediments needed for stability. A recently completed MMS
                study of the navigation channel impacts on barrier beaches indicated accelerated erosion near channels
                immediately downdrift from a jetty (Wicker et al., 1989).
                    The construction of new onshore support facilities could result in loss of barrier habitat and the possible
                need to stabilize the beach from subsequent erosion to protect the construction. Previous studies have shown
                that efforts to stabilize and "armor" beaches can lead to accelerated erosion.


                Base Case Ana4uis

                    Oil spills associated with the proposed action can occur from a number of sources. Spills can occur
                offshore as a result of platform accidents, barge or tanker collisions, and pipeline breaks. Spills can also occur
                inshore as a result of barge, pipeline, and storage tank accidents.
                    According to Table IV-22, there is less than a 0.5 percent chance of an offshore spill greater than or equal
                to 1,000 bbl occurring and contacting a coastal barrier within 10 days. Based on this low probability, the
                assumption is that no spills greater than or equal to 1,000 bbl from offshore sources will occur and contact a
                coastal barrier. Furthermore, no spills greater than or equal to 1,000 bbl from shuttle tankers in port are
                assumed to occur under the Base Case scenario.
                    No offshore spills less than 1,000 bbl are assumed to occur and contact the coast during the 35-year life
                of the proposed action (Section IV.C.1.). No coastal spills greater than 50 bbl and less than 1,000 bbl are
                assumed to occur under the Base Case scenario in the WPA_ Several spills greater than 1 and less than or
                equal to 50 bbl are assumed to occur inshore as a result of barge accidents near terminals. There are several
                ports located behind barrier islands from Matagorda Bay to Sabine Pass that receive barged oil. Further, two
                terminals in western Louisiana receive oil produced in the WPA (Table IV-16). It is assumed that a few spills
                near these terminals will occur. The small slick produced as a result of a less-than-50-bbl spill will evaporate
                and spread as it is transported across a bay or sound before reaching the back side of an island. A small
                percentage of the oil could also be transported through a barrier channel to the seaward side of the island.
                The small amount of oil that contacts the beach would be manually cleaned within a week with no removal
                of beach sand. Furthermore, it is assumed that the Padre Island National Seashore along the South Texas










                IV-376

                coast will not be contacted by the spill associated with the Base Case because no oil terminals iaccur in the area
                (Table IV-16), no oil pipelines make landfall in the area (Visual No. 1), and the offshore area is gas, rather
                than oil, prone.
                     Oil from these spills is not assumed to affect sand dune vegetation. In the area, dune line heights range
                from 0.5 to 1.3 m above mean high tide levels. For tides to reach or exceed these levels, stronly southerly winds
                would have to persist for an extended period prior to or immediately after the spill. An analysis of 37 years
                of tide gauge data from Grand Isle, Louisiana (data are also available for Galveston, Texas, but have not yet
                been analyzed), shows that the probability of water levels reaching sand dune elevations ran:ges from 0 to 16
                percent. The combined probabilities of a small spill associated with the proposed action and tidal inundation
                of sand dune vegetation are a very unlikely event. In addition, the strong winds required to produce the high
                tides would disperse and spread the off slick and reduce oil concentrations along the coast. Furthermore, a
                recent study in Texas has shown that the disposal of oiled sand on vegetated sand dunes had no deleterious
                effects on the existing vegetation or on the recolonization of the oiled sand (Webb, 1988). Given all of these
                considerations, it is assumed that oil spills will not affect sand dune vegetation.
                    No new pipeline landfalls are projected to occur under the Base Case scenario (Table IV-11).
                Furthermore, in the event of a pipeline landfall as a result of an unforeseen hydrocarbon diicovery, modern
                techniques of pipeline emplacement and planning procedures can reduce pipeline crossing impacts to negligible
                (LeBlanc, 1985; Mendelssohn and Hester, 1988; Wicker et al., 1989).
                    No new navigation facilities or infrastructure is expected under the Base Case scenario (Table IV-13);
                therefore, impacts from these activities are precluded. Some periodic maintenance dredgirig of navigation
                channels through barrier passes is expected, but this activity has not been documented as having a noticeable
                effect on barrier morphology. Furthermore, the contribution of the Base Case scenario to the vessel traffic
                within navigation channels is very small (Table IV-6), so that only a small percentage of maintenance dredging
                can be attributed to activities associated with the Base Case.
                    Section IV.A.3.c.(3)(c) states that a channel in onshore Subarea W-1 (the Corpus Christi, Texas, area) win
                be deepened to 6.7 m (22 ft) to provide access for larger service vessels that are expected to be. used for deep-
                water ope rations. Navigable barrier passes in this area exceed this depth. It is assumed that channel
                deepening will occur in waterways located behind barrier islands that provide access to support base locations.
                Deepening the channel will not affect barrier islands.

                Summary

                    Although a few spills greater than 1 and less than or equal to 50-bbl are assumed to occur in coastal areas
                of the WPA and contact barrier landforms, these spills will result in only a light oiling of a small stretch of
                back-barrier beach. The spilled oil will be cleaned manually within a week with no ellects on beach
                morphology.
                   Impacts   from onshore and nearshore construction of OCS-related infrastructure (pipeline landfalls,
                navigation channels, service bases, platform yards, etc.) are not expected to occur, because no new
                infrastructure construction is anticipated as a result of the proposed action. Although some maintenance
                dredging is expected to occur, this activity has not been shown to have a negative impact on barriers, and the
                need for dredging cannot be attributed to the small percentage of vessel traffic in these channels accounted
                for by Base Case activities.

                Conclusion

                   .The proposed action is not expected to result in permanent alterations of barrier beach configurations,
                except in localized areas downdrift from channels that have been dredged and deepened. The contribution
                to this localized erosion is expected to be less than I percent.











                                                                                                                           IV-377


                 High Case Analysis

                     According to Table IV-22, there is less than a 1 percent chance of an offshore spill greater than or equal
                 to 1,000 bbl occurring and contacting a coastal barrier within 10 days. The assumption based on this low
                 probability is that no spills greater than or equal to 1,000 bbI from offshore sources will contact a coastal
                 barrier. Furthermore, no spills greater than or equal to 1,000 bbI from shuttle tankers in port are assumed to
                 occur under the High Case scenario.
                     No offshore spills less than 1,000 bbl are assumed to occur and contact the coast during the 35-year life
                 of the proposed action (Section IV.C.1.). No coastal spills greater than 50 and less than 1,000 bbl are assumed
                 to occur inshore under the High Case scenario (Section IV.C.1.). Several spills greater than 1 and less than
                 or equal to 50 bbl are assumed to occur inshore as a result of barge accidents near terminals. There are
                 several ports located behind barrier islands from Matagorda Bay to Sabine Pass that receive barged oil. In
                 addition, two terminals in western Louisiana receive oil produced in the WPA (Table IV-16). It is assumed
                 that one spill near one of these terminals will occur. The small slick produced as a result of a less-than-50-bbl
                 spill will evaporate and spread as it is transported across a bay or sound before reaching the back side of an
                 island. The small amount of oil that contacts a beach would be cleaned manually within a week with no
                 removal of beach sand. No impacts from these small spills are assumed to occur. Furthermore, it is assumed
                 that the Padre Island National Seashore along the South Texas coast will not be contacted by the spill
                 associated with the High Case because no oil terminals occur in the area (Table IV-16), no oil pipelines make
                 landfall in the area (Visual No. 1), and the offshore area is gas, rather than oil, prone.
                     Oil from these small spills is not assumed to affect sand dune vegetation. In the area, dune line heights
                 range from 0.5 to 1.3 in above mean high tide levels. For tides to reach or exceed these levels, strong southerly
                 winds would have to persist for an extended period prior to or immediately after the spill. An analysis of 37
                 years of tide gauge data from Grand Isle, Louisiana (data are also available for Galveston, Texas, but have not
                 yet been analyzed), shows that the probability of water levels reaching sand dune elevations ranges from 0 to
                 16 percent The combined probabilities of a small spill associated with the proposed action and tidal
                 inundation of sand dune vegetation are a very unlikely event. In addition, the strong winds required to produce
                 the high tides would disperse and spread the oil slick and reduce oil concentrations along the coast.
                 Furthermore, a recent study from Texas has shown that the disposal of oiled sand on vegetated sand dunes had
                 no deleterious effects on the existing vegetation or on the recolonization of the oiled sand (Webb, 1988). The
                 assumption based on all of these considerations is that oil spills will not affect sand dune vegetation.
                     No new pipeline landfalls are projected to occur under the High Case scenario (Table IV-13).
                 Furthermore, in the event of a pipeline landfall as a result of an unforeseen hydrocarbon discovery, modern
                 techniques of pipeline emplacement and planning procedures can eliminate pipeline crossing impacts (LeBlanc,
                 1985; Mendelssohn and Hester, 1988; Wicker et al., 1989).
                     No new navigation facilities or infrastructure are expected to be dredged under the High Case scenario
                 (Table IV-13); therefore, impacts from these activities are precluded. Some periodic maintenance dredging
                 of navigation channels through barrier passes is expected, but this activity has not been documented as having
                 a noticeable effect on barrier morphology. Furthermore, the contribution of the High Case scenario to the
                 vessel traffic within navigation channels is estimated to be only 0.4 percent, so that only a small percentage of
                 maintenance dredging can be attributed to activities associated with the High Case.
                     Section IV.A.3.c.(3)(c) states that a channel in onshore Subarea W-1 (the Corpus Christi, Texas area) will
                 be deepened to 6.7 in (22 ft) to provide access for larger service vessels that are expected to be used for deep-
                 water operations. Navigable barrier passes in this area exceed this depth. It is assumed that channel
                 deepening will occur in waterways that are located behind barrier islands and provide access to support base
                 locations. Deepening the channel will not affect barrier islands.

                 Conclusion


                     The High Case scenario is not expected to result in permanent alterations of barrier beach configuration,
                 except in localized areas downdrift from channels that have been dredged and deepened. The contribution
                 to this localized erosion is expected to be less than 1 percent.










                 IV-378

                 (b) Wedatuls

                     The wetlands considered in this analysis include forested wetlands (swamps), tidal marshes, and seagrasses.
                 Seagrasses are restricted in the WPA to shallow water areas behind barrier islands south of Corpus Christi,
                 Texas. The most extensive areas of seagrass beds occur in Laguna Madre. Impact-producing factors resulting
                 from OCS off and gas activities that could adversely affect wetlands include oil spills, pipeline placements,
                 dredging of new navigation channels, maintenance dredging and vessel usage of existing navigation channels,
                 and construction of onshore facilities in wetland areas. Section IV.D.1.a.(1)(b) contains a di;cussion of these
                 impact-producing factors, which is summarized below.
                     Numerous investigators have studied the immediate impacts of off spills on wetland habitats in the Gulf
                 area. The often times seemingly contradictory impact assessment conclusions from these studies can at least
                 partially be explained by differences in the oil concentrations contacting vegetation, the kinds of oil spilled
                 (heavy or light crude, diesel, fuel oil, etc.), the type of vegetation affected, the season of year, the preexisting
                 stress level of the vegetation, and numerous others factors. In general, however, the data suggest that, in the
                 absence of heavy oiling, impacts will be short-term (plant dieback with recovery within two growing seasons
                 or less) and reversible, i.e., the wetland area will be revegetated without artificial replanting (Webb et al., 1985;
                 Alexander and Webb, 1987; Lytle, 1975; Delaune et al., 1979, Fischel et al., 1989).
                     The concentration of oil above which impacts to wetlands will be long-term (greater than two growing
                 seasons) and irreversible (plant mortality and some permanent wetland loss in the absence of a replanting
                 program or other form of mitigation) is currently unknown. A dearth of data exists on the long-term (three
                 years or more) effects of off spills on wetlands recovery and functioning. This EIS assumes that the minimum
                 oil concentrations that result in long-term, permanent impacts will be one of two values, depending on the
                 wetland type contacted. In the stressed environment of coastal Louisiana, where the wetland loss rate has been
                 as high as 0.86 percent per year within the recent past, wetlands are assumed to be more sensitive to oil
                 contacts than elsewhere in the Gulf. The work of Mendelssohn and his colleagues (Fischel et al., 1989;
                 Mendelssohn et al., 1990) is providing much needed data on the long-term effects of oil spills on coastal
                 marshes in Louisiana. The spill (a 300-bbl spill from a pipeline rupture within the marsh) occurred in 1985.
                 The response and recovery of the marsh vegetation have been monitored since that time. The results of these
                 investigations are used in this analysis to develop assumptions about the effects of an oil spill associated with
                 activities in the WPA on wetlands in the western part of coastal Louisiana.
                     Wetlands in Texas are not experiencing the wetlands loss problem occurring in Louisiana. Texas wetlands
                 occur on a more stable substrate, receive more sediment per unit of wetland area, and have not experienced
                 the alterations (canal dredging) that characterize wetlands in Louisiana. The work of Webb and his colleagues
                 (Webb et al., 1981; Webb et al., 1985; Alexander and Webb, 1983 and 1985) is used to evaluate the impacts
                 of spills in these settings.
                     The following assumptions, based on the above studies, are being used to analyze the effects of oil spills
                 on coastal wetlands. In the western part of coastal Louisiana, it is assumed that the critical concentration of
                 oil that will result in long-term impacts to wetlands is 0.1 I/m2. Concentrations less than this value will cause
                 dieback of the above-ground vegetation for one growing season, but only limited mortality to the vegetation.
                 Concentrations above this value will result in 35 percent of the contacted vegetation experiencing either dieback
                 or mortality. Within 4 years, 35 percent of this affected area will recover. Recovery will occur for 10 years.
                 After 10 years, it is assumed that 10 percent of the affected wetland area will have been permanently lost as
                 a result of accelerated landloss caused by the spill. If the spill contacts wetlands exposed to wave attack,
                 additional accelerated erosion of the wetland fringe will occur, as documented by Alexander and Webb (1987).
                 Oil will persist in the wetland soil for at least five years.
                     In Texas, the critical concentration is assumed to be 1.0 I/M2 (Alexander and Webb, 1983). Concentrations
                 below this value will result in above-ground vegetative dieback for one growing season. Concentrations above
                 this value will result in longer-term impacts to wetland vegetation because some complete plant mortality will
                 occur, and these areas will have to be recolonized. It is assumed that 50 percent of the contacted vegetation
                 will dieback or be killed after contact, and that 10 years will be required for complete recovery. In wetlands










                                                                                                                              IV-379

                 that border the coast or large estuaries, accelerated shore erosion will occur as a result of the weakened roots
                 of the marsh vegetation being unable to hold the soil together against wave attack.
                     Seagrass vegetation has generally experienced minor damage from oil-spill occurrences (Zieman et al.,
                 1984; Chan, 1977). The relative insusceptibility of seagrasses to oil-spill impacts is partly the result of their
                 subtidal location, which protects them from direct contact with oil, and partly the result of seagrasses having
                 a large percentage of their biomass occurring as roots and rhizomes, which are buried in sediment. The large
                 root mass allows the plants to regenerate from damage to their vegetative parts. The major impact to seagrass
                 communities from oil spills has been to the associated faunal assemblages.
                     It is assumed that an oil spill that moves into a seagrass area will cause some damage to the vegetation.
                 The impact will depend on the water depth in the affected area. Seagrasses generally occur at shallow depths.
                 Because of these shallow depths, it is assumed that a spill contact will cause some seagrass dieback for one
                 growing season. No permanent loss of seagrass habitat will result from the spill. The faunal community within
                 the bed will also be affected in terms of community composition and numbers of organisms.
                     Pipeline projects in wetland areas have both direct and indirect impacts on coastal habitats. Today,
                 pipeline canals are backfilled after the pipeline is installed in its ditch. Backfilling, by partially filling in the
                 canal and leveling spoil banks, greatly reduces impacts caused by drainage alterations and encourages the
                 revegetation of the pipeline canal itself. In the area potentially affected by the proposed sale, it is assumed
                 that a pipeline project in wetlands results in 0.68 ha of deteriorated or converted wetland per kilometer of
                 pipeline (Turner and Cahoon, 1987).
                     Pipeline installations through seagrass beds affect the habitat due to direct losses from dredging and
                 indirect losses that result from turbidity effects and prop washing from pipe-laying barges.
                     Service vessels, pipe-laying barges, crude oil barges, and production platforms use navigation channels,
                 some of which were dredged or improved mainly for OCS development, to connect onshore facilities with
                 offshore destinations. The dredging of new navigation canals results in impacts to wetlands similar to the
                 impacts associated with open ditch (nonbackfilled) pipeline canals.
                     Additional impacts to wetlands can occur from periodic maintenance dredging and deepening of navigation
                 channels, and from the erosion of channel banks as a result of vessel wakes.
                     Various kinds of onshore facilities have been constructed to service OCS development (Section W.A.).
                 The construction of these facilities in wetland areas could result in the conversion of wetland habitat to upland.

                 Base Case Ana4uis
                     Oil spills associated with the proposed action can occur from a number of sources. Spins can occur
                 offshore as a result of platform accidents, barge or tanker collisions, and pipeline breaks. Spills can also occur
                 inshore as a result of barge, pipeline, and storage tank accidents.
                     According to Table IV-22, the probability of a spill of 1,000 or more bbl occurring and contacting wetland
                 areas within 10 days under the Base Case ranges from less than 0.5 percent to 1.0 percent. Because of these
                 low probabilities, no spills greater than or equal to 1,000 bbl from offshore sources are assumed to contact
                 coastal wetlands. Further, no spills greater than or equal to 1,000 bbl from shuttle tankers in port are assumed
                 to occur (Table IV-16).
                     No spills greater than 50 and less than 1,000 bbl are assumed to occur and contact the coast (Section
                 IV.C.1.). Eight offshore spills greater than 1 and less than or equal to 50 bbl are assumed to occur, but none
                 is assumed to contact the coast.
                     Fewer than 10 spills (Table IV-5) greater than 1 and less than or equal to 50 bbl are assumed to occur
                 onshore or nearshore as a result of pipeline and/or barge accidents. No spills greater than 50 and less than
                 1,000 bbl are assumed to occur inshore (Table IV-5). The spills greater than 1 and less than or equal to 50
                 bbl are assumed to occur in association with a pipeline, barge, or shuttle tanker accident. According to Table
                 IV-5, nearly all of the oil transported by pipeline will land in onshore subareas W-1 and W-2, with a small
                 percentage landing in C-3. Most barge traffic will offload in W-2, with some offloading in C-1, and most shuttle
                 tanker offloadings, will occur in W-1 and W-2. Based on these considerations, it is assumed that a few spills
                 will occur in onshore subarea W-2, and one spill in W-1. Barge and tanker spills are assumed to occur near
                 terminals. Because many navigation channels used by barge traffic have spoil banks, it is assumed that most










                 IV-380

                 of the spilled oil will be confined to the channel. The slick will be quickly transported and spread through the
                 channel by tidal and wind currents. The small amount of the off transported onto wetland areas is not assumed
                 to have adverse effects on wetland vegetation. The oil will have lost its identity as a slick b, the time that it
                                                                                                                  Y
                 could be transported near seagrass beds. No impacts to the beds are assumed as a result of contact from these
                 low concentrations of oil.
                     Because pipelines traverse wedand areas, a pipeline accident could result in oil directly contacting wetland
                 habitats. Base concentrations of oil could contact limited areas of wetland vegetation as a result of these spills.
                 Using the assumptions developed in the introduction to this analysis, concentrations of oil greater than 1.0 I/m2
                 will result in impacts to wetland vegetation that persist for longer than one growing season. Given the small
                 amounts of oil associated with these spills and the likelihood that much of the oil will be confined to a
                 navigable channel, only small amounts of short-term (one growing season) dieback of above ground vegetation
                 are assumed as a result of these spills.
                     According to Table IV-5, 24,000 bbl of produced sands and 406,000 bbl of drilling fluids wjR be transported
                 to shore for disposal under the Base Case scenario. According to USEPA information, sufficient disposal
                 capacity exists at operating disposal sites, and no new disposal sites will be required to acoammodate these
                 wastes. Therefore, no wetland areas will be disturbed as a result of the establishment of new disposal sites.
                 Some seepage from waste sites may occur into adjacent wetland areas and result in damage to wetland
                 vegetation.
                     Pipeline landfall projects can affect wetland and seagrass habitats in a number of ways. Modern installation
                 methods and planning procedures, however, have reduced levels of impacts associated with pipeline projects
                 (Turner and Cahoon, 1987). Furthermore, no onshore pipeline projects are expected as a result of the Base
                 Case scenario (Section IV.A_3.b.(l)). Therefore, no impacts are expected.
                     No new navigation channel dredging is anticipated (Section W.A.3.c.(3)(c)); however, some maintenance
                 dredging of existing channels will occur during the 35-year life of the proposed action. The disposal of dredged
                 material could negatively affect wetlands if it is deposited onto existing banks or if previously unaffected
                 wetland areas are buried by spoil banks. On the other hand, dredged material could also be used as a
                 sediment supplement in deteriorating wetland areas to enhance wetland growth. As of 1988, however, the use
                 of dredged material for marsh enhancement has been done only on a limited basis (Section IV.B.2.b.(2)).
                 Given an anticipated increasing emphasis on using dredged material for marsh creation purposes, it is assumed
                 that during the 35 year life of the proposed action, dredged material will be used to enhance wetland habitats.
                 Maintenance dredgingwill also temporarily increase turbidity levels, which could deleteriously affect seagrasses.
                 Major navigation canals, however, are not located near seagrass beds in the area. Only 0.2 percent of channel
                 usage will be accounted for by OCS vessels under the Base Case. Because of this small percentage of usage
                 and the likelihood that much of the dredged material will be used to enhance wetland habitats, it is assumed
                 that no impacts will occur to wetlands from maintenance dredging.
                     As discussed in Section IV.A.3.c.(3)(c), OCS activities in deep water are requiring larger service vessels
                 for efficient operations. Currently, service bases in Galveston, Texas, and Berwick, Louisiana, are accessible
                 to the larger vessels, and Empire and Cameron, Louisiana, are considered marginally usable. This document
                 assumes that one channel in onshore Subarea W-1 (the Corpus Christi area) will be deepened to 6.7 m (22 ft).
                 Navigable barrier passes in this area exceed this depth. It is assumed that channel deepening will occur in
                 waterways located near support facility locations. As discussed in the analysis of impacts to wetlands in the
                 CPA (Section IV.A_1.a.(l)(b)), the dredged material generated by the deepening project will be used to
                 enhance wetland growth, rather than be disposed of onto spoil banks adjacent to the channel.. No impacts to
                 wetlands are therefore anticipated as a result of the channel-deepening project.
                    Vessel traffic within navigation channels can cause channel bank erosion in wetland areas. An idea of the
                 magnitude of OCS vessel traffic is provided in Tables IV-5 and IV-6, which show projected numbers of barge,
                 service vessel, and shuttle tanker landings and dockings at various ports. Over the 35-year life of the proposed
                 action, about 9 barge trips and 8,300 service vessel trips will occur within navigation channels. Additional vessel
                 usage of navigation channels will be required for pipe-laying barges and the movement of platforms to offshore
                 locations. Most of this vessel traffic will use channels within the Texas (onshore Subareas W-1 and W-2) and
                 western Louisiana coastal zone where the impacts will be assessed. According to Johnson and Gosselink
                 (1982), channels that have high navigational usage in coastal Louisiana widen about 1.5 m/yr More rapidly than










                                                                                                                         IV-381

              channels that have little navigational usage (2.58 m/yr versus 0.95 m/yr). It is assumed that this figure applies
              to the potential impact area associated with the proposed action, even though most of this area is within the
              State of Texas. According to Table IV-6, there are 15 channels that are used by OCS vessel traffic related to
              Sale 143. The OCS usage of these channels will account for about 0.2 percent of the total channel traffic.
              Assuming an average distance along a channel to a service base and other OCS facilities is 10 kin in the area,
              and that wetlands fringe the channel over one half this distance, the estimate of channel erosion impacts is that
              less than 1 ha of wetlands will be eroded along channel banks during the 35-year life of the proposed action.
                   Ten platform complexes are expected to be installed offshore as a result of the Base Case scenario (Table
              IV-3). The erosion of channel margins as a result of towing production structures through navigation channels
              is accounted for in the calculations in the previous paragraph. The possibility is considered here that increased
              emphasis on deep-water operations in the future may require larger platforms that will cause increased channel
              bank erosion compared to the past As production moves into deep-water areas of the Gulf, the use of floating
              production systems, as opposed to fixed platforms, is being considered, particularly for fields of marginal size
              that cannot economically justify a platform. Two floating production systems are projected to be used under
              the Base Case scenario for Sale 143. Further, compliant structures are being increasingly used for deep-water
              operations. These structures use tethering cables rather than massive steel legs for anchoring the platform deck
              to the seabed. Towing the decks of these platforms through coastal channels will not cause more erosion than
              towing a traditional platform. Furthermore, in recent years some compliant structure decks have been
              purchased from overseas manufacturers. Given the above considerations, this analysis does not expect
              increased erosion of wetlands from the towing of deep-water structures through navigation channels.
                   No new construction of onshore infrastructure is anticipated (Table IV-14). Therefore, no impacts to
              wetlands from new construction projects are expected.

              Summary

                   No oil spills greater than or equal to 1,000 bbl from offshore or inshore sources are assumed to occur and
              contact coastal wetlands under the Base Case scenario. Several smaller spills (greater than I and less than or
              equal to 50 bbl) are assumed to contact wetlands from inshore barge and pipeline accidents in coastal Texas.
              None of these accidents is assumed to result in high-enough off concentrations contacting wetlands to result
              in impacts. Seagrass beds will not be affected by the low oil concentrations associated with these spills.
                   No new dredging projects for pipelines or navigation channels are projected. Few to no impacts from
              maintenance dredging are expected given the small contribution of OCS vessel traffic to navigational usage of
              the channels. Furthermore, alternative dredged material disposal methods that could be used to enhance
              coastal wetland growth exist. Deepening of one channel to accommodate larger service vessels is expected to
              occur. This project will affect only the upper reaches of a navigation channel near a service base complex.
              The dredged material will be disposed of in a way that will enhance wetland habitats.
                   Erosion of wetlands from OCS vessel wakes is expected to result in less than 1 ha of wetlands loss during
              the 35-year life of the proposed action.

              Conclusion


                   The proposed action is expected to result in no permanent alterations of wetland habitats, except for the
              erosion of less than 1 ha of wetlands along navigation channel margins. These losses could be offset or even
              exceeded by wetlands gains from the beneficial disposal of dredged material generated during channel
              maintenance and deepening operations.

              High Case Analysis

                   Oil spills associated with the proposed action can occur from a number of sources. Spills can occur
              offshore as a result of platform accidents, barge or tanker collisions, and pipeline breaks. Spills can also occur
              inshore as a result of barge, pipeline, and storage tank accidents.










                  IV-382

                      According to Table IV-22, the probability of a spill of 1,000 or more bbl occurring and cDntacting wetland
                  areas within 10 days under the High Case ranges from less than 0.5 percent to 1.0 percent. Because of these
                  low probabilities, no spills greater than or equal to 1,000 bbl from offshore sources are assumed to contact
                  coastal wetlands. Further, no spills greater than or equal to 1,000 bbl from shuttle tankers in port are assumed
                  to occur (Table IV-16).
                      No spills greater than 50 and less than 1,000 bbl are assumed to occur and contact the coast (Section
                  W.C.1.). Eight offshore spills greater than 1 and less than or equal to 50 bbl are assumed to occur, but none
                  is assumed to contact the coast
                      Fewer than 10 spills (Table IV-5) greater than I and less than or equal to 50 bbl are assumed to occur
                  onshore or nearshore as a result of pipeline and/or barge accidents. No spills greater than 50 bbl are assumed
                  to occur inshore (Table IV-5). The spills greater than 1 and less than or equal to 50 bbl are assumed to occur
                  in association with a pipeline, barge, or shuttle tanker accident. According to Table IV-5, nearly all of the oil
                  transported by pipeline will land in onshore Subareas W-1 and W-2, with a small percentage Landing in Subarea
                  C-3. Most barge traffic will offload in W-2, with some offloading in C-1, and most shuttle tanker offloadings
                  will occur in Subareas W-1 and W-2. Based on these considerations, it is assumed that a few spills will occur
                  in onshore Subarea W-2, and one spill in W-1. Barge and tanker spills are assumed to occur near terminals.
                  Because many navigation channels used by barge traffic have spoil banks, it is assumed that most of the spilled
                  oil will be confined to the channel. The slick will be quickly transported and spread through the channel by
                  tidal and wind currents. The small amount of the oil transported onto wetland areas is not assumed to have
                  adverse effects on wetland vegetation. The oil will have lost its identity as a slick by the time that it could be
                  transported near seagrass beds. No impacts to the beds are assumed as a result of contact from these low
                  concentrations of oil.
                      Because pipelines traverse wetland areas, a pipeline accident could result in oil directly contacting wetland
                  habitats. High concentrations of oil could contact limited areas of wetland vegetation as a result of these spills.
                  Using the assumptions developed in the introduction to this analysis, concentrations of oil greater than 1.0 I/m2
                  will result in impacts to wetland vegetation that persist for longer than one growing season. Given the small
                  amounts of oil associated with these spills and the likelihood that much of the oil will be confined to a
                  navigable channel, only small amounts of short-term (one growing season) dieback of above-ground vegetation
                  are assumed as a result of these spills.
                      According to Table IV-5, 64,000 bbl of produced sands and 872,000 bbl of drilling fluids will be transported
                  to shore for disposal under the High Case scenario. According to USEPA information, sufficient disposal
                  capacity exists at operating disposal sites, and no new disposal sites will be required to accommodate these
                  wastes. Therefore, no wetland areas will be disturbed as a result of the establishment of new disposal sites.
                  Some seepage from waste sites may occur into adjacent wetland areas and result in damage to wetland
                  vegetation.
                      Pipeline landfall projects can affect wetland and seagrass habitats in a number of ways. Modern installation
                  methods and planning procedures, however, have reduced levels of impacts associated with pipeline projects
                  (Turner and Cahoon, 1987). Furthermore, no onshore pipeline projects are expected as a result of the High
                  Case scenario (Section IV.A.3.b.(I)). Therefore, no impacts are expected.
                      No new navigation channel dredging is anticipated (Section W.A.3.c.(3)(c)); however, some maintenance
                  dredging of existing channels will occur during the 35-year life of the proposed action. The disposal of dredged
                  material could negatively affect wetlands if it is deposited onto existing banks or if previously unaffected
                  wetland areas are buried by spoil banks. On the other hand, dredged material could also be used as a
                  sediment supplement in deteriorating wetland areas to enhance wetland growth. As of 1988, however, the use
                  of dredged material for marsh enhancement has been done only on a limited basis (Section IV.B.2.b.(2)).
                  Based on an anticipated increasing emphasis on using dredged material for marsh creation purposes, it is
                  assumed that during the 35-year life of the proposed action, dredged material will be used to enhance wetland
                  habitats. Maintenance dredging will also temporarily increase turbidity levels, which could deleteriously affect
                  seagrasses. Major navigation canals, however, are not located near seagrass beds in the area. Only 0.4 percent
                  of channel usage will be accounted for by OCS vessels under the High Case. Because of this small percentage
                  of usage and the likelihood that much of the dredged material will be used to enhance wetland habitats, it is
                  assumed that no impacts will occur to wetlands from maintenance dredging.










                                                                                                                          IV-383

                  As discussed in Section IV.A_3.c.(3)(c), OCS activities in deep water are requiring larger service vessels
              for efficient operations. Currently, service bases in Galveston, Texas and Berwick, Louisiana, are accessible
              to the larger vessels, and Empire and Cameron, Louisiana, are considered marginally usable. This document
              assumes that one channel in onshore Subarea W-1 (the Corpus Christi area) will be deepened to 6.7 m (22 ft).
              Navigable barrier passes in this area exceed this depth. It is assumed that channel deepening will occur in
              waterways located near support facility locations. As discussed in the analysis of impacts to wetlands in the
              CPA (Section IV.A.La.(l)(b)), the dredged material generated by the deepening project will be used to
              enhance wetland growth, rather than disposed of onto spoil banks adjacent to the channel. No impacts to
              wetlands are therefore anticipated as a result of the channel deepening project
                  Vessel traffic within navigation channels can cause channel bank erosion in wetland areas. An idea of the
              magnitude of OCS vessel traffic is provided in Tables IV-5 and IV-6, which show projected numbers of barge,
              service vessel, and shuttle tanker landings and dockings at various ports. Over the 35-year life of the proposed
              action, about 22 barge trips and 19,500 service vessel trips will occur within navigation channels. Additional
              vessel usage of navigation channels will be required for pipe-laying barges and the movement of platforms to
              offshore locations. Most of this vessel traffic will use channels within the Texas (onshore subareas W-1 and
              W-2) and western Louisiana coastal zone, where the impacts will be assessed. According to Johnson and
              Gosselink (1982), channels that have high navigational usage in coastal Louisiana widen about 1.5 mlyr more
              rapidly than channels that have little navigational usage (2.58 m/yr versus 0.95 m/yr). It is assumed that this
              figure applies to the potential impact area associated with the proposed action, even though most of this area
              is within the State of Texas. According to Table IV-6, there are 15 channels that are used by OCS vessel traffic
              related to Sale 143. The OCS usage of these channels will account for about 0.4 percent of the total channel
              traffic. Assuming an average distance along a channel to a service base and other OCS facilities is 10 km in
              the area, and that wetlands fringe the channel over one half this distance, the estimate of channel erosion
              impacts is that about 2 ha of wetlands will be eroded along channel banks during the 35-year life of the
              proposed action.
                  Thirty platform complexes are expected to be installed offshore as a result of the High Case scenario
              (Table IV-3). The erosion of channel margins as a result of towing production structures through navigation
              channels is accounted for in the calculations in the previous paragraph. The possibility is considered here that
              increased emphasis on deep-water operations in the future may require larger platforms that will cause
              increased channel bank erosion compared to the past. As production moves into deep water areas of the Gulf,
              the use of floating production systems, as opposed to fixed platforms, is being considered, particularly for fields
              of marginal size that cannot economically justify a platform. Two floating production systems are projected
              to be used under the High Case scenario for Sale 143. In addition, compliant structures are being increasingly
              used for deep-water operations. These structures use tethering cables rather than massive steel legs for
              anchoring the platform deck to the seabed. Towing the decks of these platforms through coastal channels will
              not cause more erosion than towing a traditional platform. Furthermore, in recent years some compliant
              structure decks have been purchased from overseas manufacturers. Based on the above considerations, this
              analysis does not expect increased erosion of wetlands from the towing of deep-water structures through
              navigation channels.
                  No new construction of onshore infrastructure is anticipated (Table IV-14). Therefore, no impacts to
              wetlands from new construction projects are expected.

              Summary

                  No off spills greater than or equal to 1,000 bbl from offshore or inshore sources are assumed to occur and
              contact coastal wetlands under the High Case scenario. Several smaller spills (greater than 1 and less than or
              equal to 50 bbl) are assumed to contact wetlands from inshore barge and pipeline accidents in coastal Texas.
              None of these accidents is assumed to result in high-enough oil concentrations contacting wetlands to result
              in impacts. Seagrass beds will not be affected by the low oil concentrations associated with these spills.
                  No new dredging projects for pipelines or navigation channels are projected. Few to no impacts from
              maintenance dredging are expected given the small contribution of OCS vessel traffic to navigational usage of
              the channels. Furthermore, alternative dredged material disposal methods that could be used to enhance










                  IV-384

                  coastal wetland growth exist. Deepening of one channel to accommodate larger service vessels is expected to
                  occur. This project will affect only the upper reaches of a navigation channel near a sendce base complex.
                  The dredged material will be disposed of in a way that will enhance wetland habitats.
                       Erosion of wetlands from OCS vessel wakes is not expected to result in more than 2 ha of wetlands loss
                  during the 35-year life of the proposed action.

                  Conclusion


                       The High Case of the proposed action is expected to result in no permanent alterations of wetland habitats,
                  except for the erosion of about 2 ha of wetlands along navigation channel margins. These losses could be offiet.
                  or even exceeded by wetlands gains from the beneficial disposal of dredged material generated during channell.
                  maintenance and deepening operations.

                  (2) Impacts on Sensitive Offshore Resources

                  (a) Deep-water Benthic Communities

                       The deep-water benthic communities consist of recently discovered organisms that are apparently most
                  abundant in water deeper than 400 m and that derive their energy, in the absence of light, from chemosynthetic
                  processes rather than the photosynthetic processes of shallow water (see Section III.B.2.b. for a more detailed.
                  discussion of these communities). The primary chemosynthetic organisms are bacteria, both free-living (as
                  "bacterial mats") and symbiotic in the tissues of other organisms, especially in the gills. The predominant, large
                  animals are tube worms, clams, and mussels. As noted in this section for the Central Gulf (Section
                  IV.D.La.(2)(b)), the only impact-producing factor threatening these communities results from those activities
                  that would physically disturb the bottom, such as the routine operations of anchoring, drilling, and pipeline
                  installation, and the rare seafloor blowout accident. Because of the great water depths, routine off and gas
                  effluent discharges such as muds, cuttings, and sanitary wastes will not cause any deleterious impacts to
                  chemosynthetic communities due to the rapid dilution and dispersion of effluent components (in shallower
                  depths, cuttings tend to form a low mound or to be worked into the surrounding sediments, depending upon
                  the nature of the local sediments, depth of disposal, and physical forces acting upon the pile). In these deep
                  waters, such discharges rapidly disperse, can be measured above background at only very short distances from
                  the discharge point, do not build up on the bottom, and have little biological effect except very close to the
                  discharge point. Because these communities use petroleum hydrocarbons as a food source (and indeed have
                  been seen to be living among oil and gas bubbles), oil spills are not considered to be a potential source of
                  adverse impacts. Thus, oil spills will have no impact on these communities.
                       As noted above in Section IV.D.La.(2)(b), the greatest potential for adverse impacts to occur to deep-
                  water chemosynthetic communities would come from those OCS-related, bottom-disturbingactivities associated
                  with pipelaying (Section IV.A_2.b.(1)), anchoring (Section IV.A_2.d.(1)(b)), and structure emplacement (Section.
                  W.A.2.d.(1)(a)), as well as a seafloor blowout (Section IV.A.2.d.(8)). These activities cause localized bottom.
                  disturbances and disruption of benthic communities in the immediate area of the drilling. For a detailed
                  discussion of the potential impacts from these activities, see Section IV.D.La.(2)(b).

                  Base Case Analysis

                     Because high-density chemosynthetic communities are found only in water depths greater than 400 m (1,312
                  ft), they will be found only in the southeast one-eighth of Subplanning Area W-1 and the southern one-third
                  of W-2; they may be found throughout W-3. Thus, these communities will not be exposed to the full level of
                  projected impact-producing factors of Table IV-3. As noted in Table IV-3, in these threesubareas a total of
                  320 wells are assumed to be drilled, 10 platform complexes installed, and 80 km (50 mi) ofpipeline installed.
                     As noted above, the majority of these deep-water communities are of low density and are widespread
                  throughout the deep-water areas of the Gulf. Disturbance to a small area would not result in a major impact










                                                                                                                           IV-385

                  to the ecosystem. For purposes of this Base Case analysis, the frequency of such impact is expected to be once
                  every six months to two years, and the severity of such an impact is judged to result in few losses of ecological
                  elements, with no alteration of general relationships.
                     High-density communities are, as noted above, largely protected by the provisions of NTL 88-11. For
                  purposes of this analysis, the frequency of some small percentage of impact is expected to be once every six
                  months to two years, but the severity of such an impact is such that there may be some loss of ecological
                  elements and/or some alteration of general relationships.

                  Summary
                     The only impact-producing factor threatening the deep-water benthic communities is physical disturbance
                  of the bottom, which would destroy the organisms comprising these communities. Such disturbance would
                  come from those OCS-related activities associated with pipelaying, anchoring, structure emplacement, and
                  seafloor blowouts. Only structure emplacement is considered to be a threat, and then only to the high-density
                  (Bush Hill-type) communities; the widely distributed low-density communities would not be at risk. The
                  provisions of NTL 88-11 (currently in effect), requiring surveys and avoidance prior to drilling, will greatly
                  reduce, but not completely eliminate, the risk.

                  Conclusion

                     The proposed action is expected to cause little damage to the physical integrity, species diversity, or
                  biological productivity of either the widespread, low-density chemosynthetic communities or the rarer, widely
                  scattered, high-density Bush Hill-type chemosynthetic communities. Recovery from any damage is expected
                  to take less than two years.

                  High Case Ana4uis

                     In the High Case Analysis, the deep-water benthic communities (e.g., chemosynthetic communities) would
                  be subject to the same impact-producing factor as in the Base Case: physical disturbance of the bottom where
                  these communities are found, such as disturbance by rig emplacement, platform and pipeline installation, and
                  anchoring. No other impact-producing factor is expected to present a threat to these deep-water communities.
                  As noted under the Base Case, it is highly unlikely that discharges from the proposed activities would adversely
                  impact the benthos in the water depths (greater than 400 m) being discussed, due to the rapid dilution and
                  dispersion of effluent components.
                     Furthermore, as in the Base Case, these communities will be found only in the southeast one-eighth of
                  Subarea W-I and the southern one-third of W-2; they may be found throughout W-3. Thus, these
                  communities will not be exposed to the full level of the projected impact-producing factors of Table IV-3. As
                  noted in Table IV-3, in these three subareas a total of 690 wells are assumed to be drilled, 30 platform
                  complexes installed, and 240 km (150 mi) of pipelines installed.
                     While the opportunities for impact are somewhat higher for this High Case than for the Base Case, NTL
                  88-11 will still be effective in detecting the high-density communities and providing for their avoidance.
                     For purposes of this analysis, the frequency of such impact to the widespread, low-density communities is
                  expected to be once every six months to two years, and the severity of such an impact is judged to result in few
                  losses of ecological elements, with no alteration of general relationships.
                     For purposes of this analysis, the frequency of some small percentage of impact (given NTL 88-11) to high-
                  density communities is expected to be once every six months to two years, but the severity of such an impact
                  is such that there may be some loss of ecological elements and/or some alteration of general relationships.

                  Conclusion

                     The High Case scenario is expected to cause little damage to the physical integrity, species diversity, or
                  biological productivity of either the widespread, low-density chemosynthetic communities or the rarer, widely










                 IV-386

                 scattered, high-density Bush Hill-type chemosynthetic communities. Recovery from any damage is expected
                 to take less than two years.

                 (b) Topographic Features

                     The topographic features of the Western Gulf providing sensitive offshore habitats are listed and described
                 in Section III.B.2.
                     A Topographic Features Stipulation similar to the one described in Section II.B.l.c.(l) has been made a
                 part of appropriate leases since 1973 and may, at the option of the Secretary, be made a part of appropriate
                 leases resulting from this proposal. As noted in Section II.B.l.c.(1), the stipulation would establish an area (No
                 Activity Zone) in which no bottom-disturbing activities would be allowed and areas around the No Activity
                 Zones (in most cases) in which shunting of all drill effluents to near the bottom would be: required. The
                 effectiveness of the stipulation in protecting the biota of the topographic features (banks) is well documented.
                 Thus, the very high potential impacts described in previous EIS's for the biota of the banks would not occur
                 as a result of this proposal if the stipulation were selected for inclusion. The impact analysis presented below
                 is for the proposed action and does include the proposed biological lease stipulation. For a complete
                 description of potential impacts to the banks from oil and gas operations absent the stipulation, see Section
                 IV.D.2.a.(2)(b) of the Final EIS for Sales 131, 135, and 137.
                     As noted in the section for the Central Gulf (Section IV.D.La.(2)(c)), the potential impact-producing factors
                 to the topographic features of the Western Gulf are anchoring and structure emplacement, effluent discharge,
                 blowouts, oil spills, and structure removal. For a detailed discussion of the potential impacts from these
                 activities, see Section IV.D.La.(2)(c). A discussion of these impacts in this specific case is given below.

                 Base Case Ana4uis

                     Eleven of the 23 topographic features of the Western Gulf are located in Subarea W-1; 12 are in W-2 (in
                 both cases they occupy a very small portion of the entire area). Thus, these communities wiL[ not be exposed
                 to the full level of the projected impact-producing factors of Table IV-3; the amounts of wastes discharged in
                 the vicinity of a bank will be some very small fraction of those shown in Table IV-3.
                     As noted above, the proposed Topographic Features Stipulation would serve to eliminate most of the
                 potential impacts to the biota of the banks from oil and gas operations. The impact-producing factors that may
                 still affect the banks from operations outside the No Activity Zones are drilling effluent discharges, blowouts,
                 and oil spills.
                     With the adoption of the proposed Topographic Features Stipulation, no discharges of drilling effluents,
                 including produced water, would take place within the No Activity Zones; discharges in areas of 1,000 in, 1,
                 3, or 4 miles, depending on the bank, around the No Activity Zone would be shunted to within 10 in of the
                 bottom. This procedure would essentially eliminate the threat of drilling effluents and produced water reaching
                 the biota of the bank; however, there may be some small risk of such effluents reaching the bank. For
                 purposes of this analysis, it is estimated that such impacts will occur 5-10 times during the life of this proposal;
                 the severity of such impacts is judged to be such that there may be a loss of a few elements at the regional or
                 local scale, but no interference to the general system performance. Recovery of the system to pre-interference
                 conditions is rapid.
                     Blowouts do not occur with great frequency (see Section IV.A.2.d.(8) and below), and with the application
                 of the proposed stipulation, none could occur within the No Activity Zones. Blowouts outside: the No Activity
                 Zones are unlikely to have an impact on the biota of the banks. Since no blowouts are assumed to occur in
                 Subareas W-1 and W-2, where the banks are found, for purposes of this analysis the frequency of a blowout
                 in the vicinity of a topographic feature is judged not to occur only during the life of this proposal. Even if one
                 were to occur near a bank, it may cause the loss of a few elements at the local scale, but no interference to
                 the general system performance would occur and recovery of the system to pre-interference cDnditions would
                 be rapid.











                                                                                                                           IV-387

                   There is an estimated 6 percent chance of an oil spill greater than or equal to 1,000 bbl occurring in the
                Western Gulf as a result of the proposed action (Base Case) (Table IV-19), and it is assumed that 8 small spills
                of greater than I and less than or equal to 50 bbl will occur each year and that no spills of greater than 50 and
                less than 1,000 bbl will occur during the 35-year life of the proposed action (Section IV.Cl.). It is assumed
                that no oil spills greater than or equal to 1,000 bbl will occur (Section IV.C.l.; Table IV-3). In the Western
                Gulf, the East Flower Garden Bank crests the shallowest at 15 m. Therefore, a surface oil spill would assume
                to have no impact on the biota of the East Flower Garden Bank or the other topographic features because
                any oil that might be driven to 15 m or deeper would be well below the concentrations needed to cause an
                impact. However, spills resulting from this proposal are assumed to be subsurface; such spills are likely to rise
                to the surface, and any oil remaining at depth will be swept clear of the banks by currents moving around the
                banks (Rezak et al., 1983). As noted above, there have been only 28 oil spills resulting from blowouts on the
                OCS between 1956 and 1989, and only 2 blowouts are assumed for the entire WPA over the 35-year life of the
                proposed action (Table IV-3). In the years 1967-1986, there have been only 31 oil spills from pipelines on the
                OCS, 23 of which were between 50 and 1,000 bbl and only 8 greater than or equal to 1,000 bbl (USDOI, MMS,
                1988b). Thus, a blowout is assumed to occur near a bank. If a seafloor oil spill were to occur, the spill would
                have to come into contact with a biologically sensitive feature. The fact that the topographic features are
                widely dispersed in the Western Gulf, combined with the probable random nature of spill locations, would serve
                to limit the extent of damage from any given spill to only one of the sensitive areas. The currents that move
                around the banks will steer any spilled oil around the banks rather than directly upon them, lessening the
                severity of impacts. Furthermore, the No Activity Zones established by the proposed Topographic Features
                Stipulation, would serve to keep such occurrences from very near the banks.

                Summary

                   Several impact-producing factors may threaten the communities of the topographic features.
                   Because of the analytical use of the proposed Topographic Features Stipulation, operational discharges
                (drilling muds and cuttings, produced waters) would have little impact on the biota of the banks. Recovery
                from any impact would be rapid.
                   Blowouts may similarly cause damage to benthic biota, but due to the analytical use of the proposed
                Topographic Features Stipulation, they would have little impact on the biota of the banks. Recovery from any
                impact would be rapid.
                   Oil spills (there is an estimated 6% chance of an oil spill greater than or equal to 1,000 bbl occurring in the
                Western Gulf as a result of this proposed action) will cause damage to benthic organisms if the oil contacts the
                organisms; such contact is considered unlikely and, because of the proposed Topographic Features Stipulation,
                spills would not occur very near to the biota of the banks.

                Conclusion


                   The proposed action is expected to cause little to no damage to the physical integrity, species diversity, or
                biological productivity of the habitats of the topographic features of the Gulf of Mexico. Small areas of 5-10
                M2 would be impacted, and recovery from this damage to pre-impact conditions is expected to take less than
                2 years, probably on the order of 2-4 weeks.

                Effects of the Base Case Without the Proposed Stipulation

                   Several impact-producing factors may threaten the communities of the topographic features.
                   Vessel anchoring and structure emplacement result in physical disturbance of the benthic environment and
                are the most likely activities to cause permanent or long-lasting impacts to sensitive offshore habitats. Recovery
                from damage caused by such activities may take 10 or more years. Impacts from this factor are considered to
                be serious and potentially irreversible.
                   Operational discharges (drilling muds and cuttings, produced waters) may impact the biota of the banks due
                to turbidity and sedimentation, resulting in death to benthic organisms in large areas. Recovery from such










                  IV-388

                  damage may take 10 or more years. Impacts from this factor are also considered to be serious and potentially
                  irreversible.
                      Blowouts may similarly cause damage to benthic biota by resuspending sediments, causing turbidity and
                  sedimentation, and resulting in death to benthic organisms. As noted above, no blowouts are assumed to occur
                  in Subareas W-1 and W-2 where the banks are found; thus, blowouts will have no impact on the biota of the
                  banks.
                  .   Oil spills will cause damage to benthic organisms if the oil contacts the organisms. As noted above, impacts
                  from this factor are not considered to be of concern.
                      Structure removal using explosives (as is generally the case) results in water turbidity, sediment deposition,
                  and potential explosive shock-wave impacts. Severe damage to benthic organisms could result. Recovery from
                  such damage could take more than 10 years. Impacts from this factor are considered to be serious.
                      It follows from the above that activities resulting from this proposal, absent the Topographic Features
                  Stipulation, especially bottom-disturbing activities, have a potential for causing serious and potentially
                  irreversible impacts to the biota of the topographic features.

                  High Case Analysis

                      Higher oil and gas activity may be expected near the topographic features of the Western Gulf as a result
                  of the High Case scenario. The biota of the topographic features would be subject to the same impact-
                  producing factors as in the Base Case--discharges associated with drilling, blowouts, and oil spills. As in the
                  Base Case, the topographic features are found only in Subareas W-I and W-2. Thus, these communities will
                  not be exposed to the full level of the assumed impact-producing factors of Table IV-3; the amounts of wastes
                  discharged in the vicinity of a bank will be some very small fraction of those shown in Table IV-3.
                      As noted above, the proposed Topographic Features Stipulation would serve to eliminate most of the
                  potential impacts to the biota of the banks from oil and gas operations. Because of the application of the
                  proposed Topographic Features Stipulation, operational discharges (drilling muds and cuttings, produced
                  waters) would have little impact on the biota of the banks. Recovery from any impact would be rapid.
                      Blowouts may similarly cause damage to benthic biota, but due to the application of the proposed
                  Topographic Features Stipulation, they would have little impact on the biota -of the banks. Recovery from any
                  impact would be rapid.
                      There is an estimated 16 percent chance of one or more oil spills greater than or equal to 1,000 bbl
                  occurring in the Western Gulf as a result of the High Case (Table IV-16). It is also assumed that 20 spills
                  greater than I and less than or equal to 50 bbl and that 1 spill greater than 50 and less than 1,000 bbl will
                  occur during the 35-year life of the proposed action. In addition, it is assumed there will be 9 spills of diesel
                  oil and other pollutants, the average size of which will be only 34 bbl (Table IV-3). It is assumed that one oil
                  spill greater than or equal to 1,000 bbl will occur (Section IV.C.1.). As with the Base Case, the widely
                  dispersed nature of the banks and the currents at the banks will serve to prevent oil from impacting the banks.
                  Therefore, it is assumed that no spills of any size will contact the biota of the topographic features.

                  Conclusion


                      The High Case scenario is expected to cause little to no damage to the physical integrity-, species diversity,
                  or biological productivity of the habitats of the topographic features of the Gulf of Mexico. Small areas of 5-10
                  M2 would be impacted, and recovery from this damage to pre-impact conditions is expected to take less than
                  2 years, probably on the order of 2-4 weeks.










                                                                                                                              IV-389

                 (3) Impacts on Water Qua1hy

                     Sections providing supportive material for the water quality analysis include Sections III.A.6. (description
                 of water quality), IV.A.2. (OCS infrastructure, activities, and impacts), IV.B.6. (major sources of oil
                 contamination in the Gulf of Mexico) and IV.C.2. (oil spills--characteristics, fates, and effects).

                 Coastal and Estuarine Waters


                     As discussed in the Sale 142 analysis (Section IV.D.La (3)), riverine flows into the Gulf of Mexico
                 determine estuarine and nearshore water quality, with the Mississippi River being the most significant source
                 of pollution to this region. Major point sources along the Gulf Coast include the petrochemical industry,
                 hazardouswaste sites and disposal facilities, agricultural and livestock farming, manufacturing industry activities,
                 fossil fuel and nuclear power plant operations, pulp and paper mill plants, commercial and recreational fishing,
                 municipal wastewater treatment, and maritime shipping activities. The Texas coastal area has been plagued
                 with numerous water quality problems, with most occurring in the Houston-Galveston and Beaumont-Port
                 Arthur areas, where the majority of Texas's energy facilities are located. Galveston Bay receives large nutrient
                 loadings from local sources and has experienced eutrophication problems. The coastal portion of the north-
                 central Gulf of Mexico (primarily Louisiana) is characterized by water quality problems resulting from the
                 discharge or release of industrial and domestic wastes. A more detailed discussion of the Gulfs coastal and
                 estuarine water quality is presented in Section 111-6.
                     Water quality in coastal and nearshore areas adjacent to the WPA may be altered by a number of OCS-
                 related activities resulting from proposed Sale 143. These include routine point and nonpointsource discharges
                 from onshore support facilities; discharges from associated support vessel traffic; canal maintenance dredging
                 and pipeline emplacement actions; onshore disposal of OCS-generated, oil-field wastes; and oil and chemical
                 spills greater than 50 bbl from both onshore and offshore OCS facilities. A general discussion of these impact-
                 producing factors may be found in Section IV.D.l.a.(3).

                 Base Case Analysis

                     Under the Base Case analysis, it is anticipated that the existing onshore infrastructure base in the Central
                 and Western Gulf is sufficient to support proposed Sale 143 activities and that no new infrastructure will be
                 constructed. Despite this, point and nonpoint source discharges (Section IV.A.3.c.) occurring from existing
                 onshore support facilities may impact coastal and nearshore water quality. Most of the onshore OCS support
                 infrastructure located in the WPA exists in the Beaumont-Port Arthur, Houston-Galveston, and Corpus Christi
                 areas. In addition, support will come from infrastructure located in southwestern Louisiana (Cameron Parish).
                 In these areas, it is anticipated that surface-water contamination from support facilities will occur. Waters near
                 support facilities may be expected to be contaminated with oily substances and oil-field wastes from point
                 source effluent discharges and small spills. For the purpose of this analysis, chronic spills and chronic point
                 source contamination are examined together with nonpointsource runoff. Section IV.C.1. provides assumptions
                 for spills from OCS facilities. It is assumed that fewer than 10 spills greater than 1 but less than or equal to
                 50 bbl are assumed to result from OCS sale-related activities throughout the Texas and southwest Louisiana
                 coastal zone. It is further assumed that 8 spills of this size class are assumed to result from proposed offshore
                 sale-related activities in the WPA, but few of these spills will contact the coastline. Petroleum hydrocarbons
                 introduced into marine and coastal waters would have various effects depending on the resource impacted,
                 stage of weathering, and local physical and meteorological conditions. Some crude oil components are highly
                 toxic and may cause damage to marine organisms. This toxicity is directly proportional to the crude's aromatic
                 content (Geraci and St. Aubin, 1988). Lower molecular weight hydrocarbon compounds (benzene, toluene,
                 etc.) are considered acutely toxic, but are rapidly lost through evaporation and dissolution during the first days
                 of a spill (Wheeler, 1978). Normal weathering processes encountered by oil spilled in open waters tend to
                 degrade its toxic components. The toxicity of the oil will be altered as weathering occurs, changing the oil's
                 composition. The oxidized derivatives of petroleum hydrocarbons generated during weathering have been










                 IV-390

                 shown to be more water soluble than the parent hydrocarbons (Mahns et al., 1982a). Boehm and Fiest (1982)
                 indicated that the average reported concentrations of oil generally were less than I 1Ag/I for pristine areas, 2-100
                 Agll for spills in nearshore areas, and 100-800 yg/I in heavily polluted urban areas. Background levels in the
                 Gulf of Mexico were reported at 0-70 gg/I. In shallow areas, oil may become entrained in siLspended particles
                 and bottom sediments, subsequently being reintroduced into the water column. From these estimates, it is
                 estimated that the effect of chronic contamination of WPA coastal waters due to the proposed sale would be
                 negligible, with water characteristics rapidly returning to background levels. These discharfres will, however,
                 remain continuous over the 35-year life of the proposed action.
                     Table IV-6 provides the number of shuttle tanker trips to each major port, the number of barge trips to
                 terminals by waterway, and the number of service vessel trips to service bases by waterway, respectively. Up
                 to 8,300 service vessel trips, 9 barge trips, and 66 shuttle tanker trips are estimated to result from proposed
                 sale-related activities. The Calcasieu River and Freshwater Bayou (C-1) in Louisiana, and Aransas Pass (W-1),
                 Matagorda Ship Channel (W-1), Houston-Galveston Ship Channel (W-2), and Sabine Pass (W-2) in Texas are
                 expected to receive the bulk of sale-related support vessel trips in the WPA. Besides barge trips to and from
                 platforms, some barge traffic carrying oil from terminals to other terminals or refineries is expected to occur
                 along the Gulf Intracoastal Waterway and adjoining navigation channels.
                    Antifouling paints used on boats and tankers have been shown to have toxic effects on some marine biota.
                 Increased loadings within coastal waters of tributyltin and copper compounds contained in antifouling paints
                 are well documented (Geochemical and Environmental Research Group, 1988; Delfino et al., 1984).
                 Tributyltin has recently been regulated to decrease the total amounts released into the environment from
                 marine paints. Without knowing what effects the new regulations will have, but knowing that effects have been
                 documented and that such discharges will take place on a routine basis for some of the fife of the proposed
                 action, impacts from antifouling paints associated with sale-related marine traffic are assumed to be low.
                 Ballast and bilge waters from shuttle tankers are assumed to be discharged at onshore reception facilities and
                 are not expected to impact coastal water quality. While inshore, service vessels are estimated to discharge
                 approximately 3,000 liters of bilge water per trip in support of sale-related activities. An estimated 21 million
                 liters (1,640 liters/day) will be discharged into coastal waters from vessels supporting the proposed sale
                 activities. Most of these discharges are assumed to occur in coastal Subarea W-2, where sale-related vessel
                 traffic are projected to be the greatest. The amount of bilge water discharged from service boats could result
                 in coastal water quality impacts when discharged into confined waters. Bilge waters may contain toxic
                 petroleum products and metallic compounds leaked from machinery. Given the small concentrations expected,
                 the continuous nature of the discharges over the life of the proposal, the widespread nature of the receiving
                 waters, and the assimilative capacity of water, it is expected that there will be some localized, short-term (up
                 to several weeks) changes in water quality characteristics from background levels, depending on the length of
                 the affected channel, flushing rates, etc.
                    No new navigation channels are expected to be dredged in association with sale-related activities; however,
                 maintenance dredging of major navigation channels and deepening of some channels to support service vessel
                 traffic are expected to result. Dredging activities are expected to result in localized impacts (primarily elevated
                 water column turbidities) occurring over the duration of the activities (up to several months). Such activities
                 would preclude some recreational and commercial uses within the immediate area. The periods for expected
                 dredging operations will generally allow for the recovery of affected areas between such activities. Impacts
                 from dredging are expected to be somewhat higher near the mouths of major rivers, where sediment inputs
                 are greater.
                    No new pipelines or canals are projected to be constructed; 82 percent of the oil and most of the gas
                 produced will be transported ashore via the existing pipeline network, while 17 percent of the off will be shuttle-
                 tankered ashore. Pipelines reduce the need for barge and truck transport of petroleum and the potential for
                 transfer spills. The environmental effects associated with chronic pipeline leakage and malfunction are
                 generally considered small (USDOC, NOAA, 1985). Given this and the small percentage of use of the existing
                 pipeline network in support of the proposed action, impacts from leakage and hydrologic alterations associated
                 with pipelines are considered negligible.
                    It is assumed the 18 percent of the drilling muds (approximately 744,000 bbl) associated with sale-related
                 drilling activities and 24,000 bbl of produced sand will be brought ashore for disposal (Table IV-4). The










                                                                                                                          IV-391

               improper storage and disposal of such oil-field wastes and contaminated oil-field equipment could result in
               adverse impacts to surface and ground-waters in proximity to disposal facilities, cleaning sites, and scrap yards.
               Many of these wastes may be contaminated by NORM (Section IV.A.2.d.(5)). Improper design and
               maintenance of such facilities could result in adverse impacts to these waters (Section IV.A.3.c.(4)). The
               quantities of many wastes attributable to OCS activities, and more specifically the proposed action, are largely
               unknown, as are the associated environmental consequences and health risks. However, study efforts are
               currently underway by Federal and State government agencies and the oil and gas industry to gather
               information on NORM, including its fate and effect and disposal and treatment alternatives.
                  The OSRA model (Table IV-22) indicates a very-low chance (1%) of an oil spin greater than or equal to
               1,000 bbl occurring from OCS operations and contacting land along the WPA coastline within 10 days. No oil
               spills of this size class is assumed to occur from the proposed action (Section IV.C.1.). It is further assumed
               that no oil spills greater than 50 and less than 1,000 bbl could occur from sale-related activities in the WPA.
               Should a spill occur, there could be some effects from residual weathered oil reaching coastal waters following
               a major spill event, primarily in the form of tar material. Impacts from low-level contamination were discussed
               earlier. Less than 10 oil spills greater than 1 and less than or equal to 50 bbI are assumed to occur in coastal
               waters from OCS pipelines crossing coastal and nearshore areas or from sale-related shuttle tankering or
               barging activities (Table IV4). Petroleum hydrocarbons introduced into marine and coastal waters may have
               varied effects depending on the resource impacted, stage of weathering, and local physical and meteorological
               conditions. Some crude off components are highly toxic and may cause damage to marine organisms due to
               the crude's aromatic content. It is expected that normal weathering processes encountered will degrade the
               oil by breaking down its toxic components. Background levels in the Gulf of Mexico were reported at 0-70 AgIL
               In shallow areas, oil may become entrained in suspended particles and bottom sediments, and subsequently
               be reintroduced into the water column. Given these estimates and the frequent nature of spills over the life
               of the proposal, the effect of hydrocarbon contamination on the Gulfs coastal waters due to the proposed
               action is considered negligible, with water characteristics rapidly returning to background levels within several
               days to weeks.

               Summary

                  All existing onshore infrastructure and associated coastal activities occurring in support of proposed Sale
               143 will contribute to the degradation of regional coastal and nearshore water quality to a minor extent because
               each activity provides a low measure of continuous contamination and because discharge locations are
               widespread, particularly in the Beaumont-Port Arthur, Houston-Galveston, and Corpus Christi areas of Texas
               and the Cameron Parish area of Louisiana. Process, cooling, boiler, and sewage water effluents Will be
               discharged through the use of the existing infrastructure and facilities. No onshore discharge of OCS produced-
               water discharges are assumed for the proposed sale. Wastes and contaminated equipment from offshore will
               be brought ashore for disposal and storage. Adverse impacts could occur to surface and groundwater in
               proximity to improperly designed and   imaintained disposal sites and facilities. Maintenance dredging is expected
               to take place every one or two years and will result in short-term impacts to the surroundingwaters. The OCS-
               related vessel traffic is likely to impact water quality through routine releases of bilge and ballast waters,
               chronic fuel and tank spills, trash, and low-level releases of the contaminants in antifouling paints. The
               improper storage and disposal of oil-field wastes and contaminated oil-field equipment would adversely impact
               surface and ground waters in proximity to disposal facilities, cleaning sites, and scrap yards. Surface and
               groundwater in proximity to improperly designed and maintained disposal sites and facilities could be adversely
               impacted with elevated concentrations of arsenic, chromium, zinc, cadmium, mercury, lead, barium, penta-
               chlorophenol, naphthalene, benzene, toluene, and radium.
                   No oil spills greater than or equal to 1,000 bbI and greater than 50 and less than 1,000 bbl are assumed to
               occur and contact coastal and nearshore waters. Eighteen spills greater than 1 but less than or equal to 50 bbl
               are assumed to result from OCS sale-related activities both in the coastal zone and from offshore (Tables IV-3
               and IV-5). Of these, fewer than 10, associated with onshore support and vessel activities, are expected to occur
               in coastal waters. Sale-related spills will introduce oil into nearshore waters, creating elevated hydrocarbon
               levels (up to 100+ gg/1) within affected waters. Much of the oil will be dispersed throughoutthe water column










                 IV-392

                 over several days to weeks. In shallow areas, oil may become entrained in suspended particles and bottom
                 sediments. Spills would affect water use for up to several weeks, and then only near the scurce of the stick.
                 Therefore, the effect of chronic contamination of WPA coastal waters due to the proposed sale is considered
                 negligible, with water characteristics rapidly returning to background levels.

                 Marine Waters

                    The Gulf of Mexico is a semi-enclosed water body with oceanic inputs through the Yucatan Channel via
                 the Caribbean and with principal outflow through the Straits of Florida. As previously noted, the presence of
                 the Mississippi River, as well as a host of other major drainage systems, strongly influences the northern Gulf
                 of Mexico's marine water quality. Drainage from approximately two-thirds of the area of the United States
                 and more than one-half the area of Mexico empties into the Gulf. This large amount of runoff, with its
                 nonoceanic composition, mixes into the surface water of the northwestern Gulf and makes the chemistry of
                 parts of this system quite different from that of the open ocean. Degradation of the Gulf's marine waters is
                 associated with coastal runoff, riverine inputs, and effluent discharges from offshore enterprises consisting of
                 OCS activities and marine transportation.
                    Effluents from normal offshore oil and gas operations are complex and may be transformed chemically,
                 biologically, or through radioactive decay when introduced into the marine environment These wastes may
                 be dissolved and form new substances or may be mixed vertically and horizontally in the water column by
                 small-scale turbulence or large-scale currents, and they may precipitate to the bottom and toe absorbed onto
                 bottom sediments, or be recycled by these same processes. These series of transformations will govern a
                 waste's transport through the water column and its effect on marine organisms. The biological effects may be
                 on individual organisms, organism populations, or entire ecosystems, with both long-term and short-term
                 consequences. The method of disposal into the environment, as well as the chemical properties of each
                 constituent, will influence a waste's distribution throughout the Gulf.
                    The impact-producing factors leading to water quality degradation resulting from offshore OCS oil and gas
                 operations include the resuspension of bottom sediments through exploration and development activities,
                 pipeline construction, and platform-removal operations; the discharge of deck drainage, sanitary and domestic
                 wastes, produced waters, drilling fluids, cuttings, and produced waters; and accidental hydrocarbon discharges
                 due to spills, blowouts, or pipeline leaks. These factors are more thoroughly discussed in Section IV.A-2.

                 Base Case Analysis

                    Table IV-3 indicates that, under the Base Case scenario, the addition of 210 exploration. and delineation
                 wells, 110 development wells, 10 platform complexes, and up to 80 km of pipeline is estimated for the WPA.
                 As a result, an estimated 126 MMbbl of produced waters, 2.24 MMbbI of drilling muds, 5445,000 bbi of drill
                 cuttings, 24,000 bbI of produced sand and 335,000 M3 of treated sanitary and domestic wastes :may be expected
                 to be generated from the proposed action.
                    Immediate effects would be brought about by increased drilling, construction, and pipelaying activities,
                 increasing water column turbidities in affected offshore waters. Pipeline construction activities may result in
                 the resuspension of some 40,000  M3 of sediment during the installation of eight kilometers of pipelines in water
                 depths of 61 m (200 ft) and less (Table IV-2). Offshore Subarea W-1 will support all sale-related pipeline
                 burial activities and associated sediment resuspension. Pipeline construction activities may result in the
                 resuspension of settled pollutants, toxic heavy metals, and pesticides, if present. The magnitude and extent of
                 turbidity increases would depend on the hydrographic parameters of the area, nature and duration of the
                 activity, and bottom-material size and composition. Sediments are known to contain the major fraction of trace
                 metals, chlorinated hydrocarbons, and nutrients in aquatic environments. Considering the very low levels of
                 trace metals found in the present-day ocean, despite the continuous output from land sources, sediments serve
                 as a permanent sink for trace metals, etc. Chen et al. (1976) indicated that concerns regarding the release of
                 significant quantities of toxic materials into solution during dredging operations and disposal. are unfounded.
                 Their studies indicate that while some trace metals may be released in the parts-per-billion range, others show
                 no release pattern. Most of the concentrations in the soluble phase are well below the allowable concentration











                                                                                                                            IV-393

                 levels of the ocean water discharge standards. It was pointed out that trace metals and chlorinated
                 hydrocarbons associated with organics and suspended particles released may present an unknown effect. For
                 the purpose of this analysis, the frequency of activities resulting in resuspension of sediment is judged to occur
                 nearly continuously throughout much of the northwestern and north-central Gulf of Mexico. However, the
                 severity of impacts would result only in some measures of water quality (primarily increased water-column
                 turbidities) changing from background levels, and then only within a distance of 1,000 m from the activity.
                     Aside from creating increased water column turbidity, explosive platform removal may adversely impact
                 water quality by releasing explosive by-products into the water column upon detonation of charges to sever the
                 legs and pilings of a structure (Table IV-3). Three platforms associated with the proposal are assumed to be
                 removed by explosive methods. The by-products of these events may be gaseous, liquid, or solid, and may be
                 soluble or insoluble in seawater. Virtually all of the products become airborne in the case of a water surface
                 burst (for scare charges), even from relatively deep explosions. In the latter, the gaseous products form a
                 spherical bubble that rises to the surface, resulting in the ejection of most of the gases. The magnitude and
                 extent of turbidity increases would depend upon several hydrographic parameters, the duration of the activity,
                 and bottom-material size and composition. The consensus of this work is that such resuspension has only a
                 short-term, local effect of a very limited nature. Because most of the gases are ejected into the air during rig
                 removal (by explosive means), the very small amounts that remain in the water column should either be
                 dissolved or dispersed so rapidly that water quality in the area would not be seriously affected.
                     The discharge of 335,000 M3 of treated sanitary and domestic wastes from the various rigs and platforms
                 will increase levels of suspended solids (14-550 mg/1), nutrients, chlorine, and BOD near the point of discharge
                 (Table IV-3). The volume and concentration of such wastes will vary widely over time, occupancy, platform
                 characteristics, and operational situation. Properly operating biological treatment systems at these facilities
                 have effluents containing less than 150 mg/I of suspended solids. These are considered minor discharges and
                 are quickly diluted. The impact to offshore water quality from sale-related, treated sanitary and domestic waste
                 discharges will be negligible, occurring within a few meters of the discharge source.
                     Up to 126 MMbbI of produced waters are estimated to result from the proposed action. Average annual
                 estimates equate to 3.6 MMbbl, or approximately 9,800 bbl per day. Offshore Subarea W-3 will receive the
                 greatest number of these discharges with 111 MMbbl. Analysis of the findings of numerous investigators (e.g.,
                 Mackin, 1973; Gallaway, 1980; Bender et al., 1979; and Reid, 1980) indicates that the estimated effects of these
                 discharges on offshore water quality will be limited to an area in proximity to the discharge source. Higher
                 concentrations of trace metals, salinity, temperature, organic compounds,and radionuclides, and lower dissolved
                 oxygen may be present near the discharge source. Although the distance required to reach background levels
                 will vary according to the volume and characteristics of each discharge, investigators suggest that these levels
                 are reached within a few meters of the source. They agree that rapid dilution and turbulence at the source
                 limit the zone affected by these properties. Because of the continuous nature of oil and gas activities within
                 the northwestern and north-central Gulf of Mexico, the frequency of produced-water discharges is judged to
                 occur somewhat continuously throughout these areas.            (Variable discharge volumes will be released
                 continuously throughout the duration of any oil and gas production operation.) The proposed produced-water
                 discharges will be rapidly diluted within the immediate vicinity of the discharge source. Significant increases
                 in water concentrations of dissolved and particulate hydrocarbons and trace metals are not expected outside
                 the initial mixing zone or immediate vicinity of the discharge source. Within the mixing zone of the discharge,
                 long-term effects to water column processes, consisting of localized increases in particulate metal and soluble
                 lower molecular weight hydrocarbon (e.g., benzene, toluene, and xylenes) concentrations, may be implicated.
                 Trace metals and hydrocarbons associated with the discharge may be deposited within sediments near the
                 discharge point.
                     Some 2.2 MMbbl of drilling muds and 546,000 bbl of drill cuttings are estimated to result from drilling
                 activities associated with the proposed action (Table IV-3). Peak-year estimates are on the order of 283,000
                 bbl of drilling muds and 72,000 bbl of drill cuttings. Drilling muds and cuttings are routinely discharged into
                 offshore waters and are regulated by NPDES permits. As with produced-water discharges, offshore Subarea
                 W-3 would receive the greatest percentage of these potential discharges. An estimated 1.89 MMbbI of drilling
                 muds and 462,000 bbl of cuttings could be generated in offshore Subarea W-3. It is assumed that 18 percent
                 of these drilling muds (400,000 bbl) associated with sale-related drilling activities would be brought ashore for










                 IV-394

                 disposal (Table IV-5). Some 24,000 bbl of produced sands are estimated to be produced in the WPA from
                 the proposed activities. However, these will not be discharged into offshore waters, but rather brought ashore
                 for disposal. As with produced-water discharges, because of the continuous nature of oil and gas activities in
                 the WPA, the frequency of drilling mud and cutting discharges is judged to occur nearly continuously
                 throughout this area. From the work of the investigators cited and previous monitoring studies, it can be
                 concluded that the proposed discharge of drilling fluids and cuttings would encounter rapid dispersion in marine
                 waters. Discharge plumes will be diluted to background levels within a period of several hours and/or within
                 several hundred to 1,000 m of the discharge source. The accumulation of toxic trace metals and hydrocarbons
                 in exposed shelf waters, due to periodic releases of water-based generic muds and cuttings, is unlikely, and the
                 long-term degradation of the water column from such discharges is not a major concern. Few effects are
                 anticipated to most water uses from drilling muds and cutting discharges and then only in an area near the
                 source.
                    Crude offs contain thousands of different compounds. Hydrocarbons account for up to 98 percent of the
                 total composition. Crude oils often contain wide concentrations of the trace metals nickel, vanadium, iron,
                 sodium, calcium, copper, and uranium. Petroleum hydrocarbons introduced into marine waters may have
                 varied effects on the local biota, with impact severity depending on the resource impacted, stage of weathering,
                 and local physical and meteorological conditions. These effects are discussed in greater detail in Section IV.C.
                 and previously in this analysis under coastal and nearshore. Oil released on the surface win be rapidly
                 dispersed by the action of winds and currents, resulting in rapid transport; whereas for a subsurface spill, some
                 of the off would be distributed throughout the water column. It is assumed that no oil spilh, greater than or
                 equal to 1,000 bbl and greater than 50 and less than 1,000 bbl, and approximately eight spills greater than or
                 equal to 1 bbl and less than or equal to 50 bbl will occur from program-related activities offshore in the WPA_
                 In addition, three spills (diesel and oil-based drilling muds) are assumed to occur from drilling and workover
                 activities. The introductionof oil into offshore waters will create elevated hydrocarbon levels (Up to 100+ Izg/1)
                 within affected waters. After 10 days, much of the oil will be dispersed throughout the water column over a
                 period of weeks. Little effect on offshore water use is expected, and then only on to an area. near the source
                 or slick.


                 Summary

                    Based on a review projected sale-related support activities, the estimate is that offshore Subarea W-1 would
                 receive the greatest portion of pipeline burial activities, whereas offshore Subarea W-3 would receive the largest
                 amounts of operational discharges. Immediate effects would be brought about by increased drilling,
                 construction, and pipelaying activities, causing an increase in water column turbidities (lasting @for several hours
                 with mud discharges, and several weeks with dredging-pipelaying activities) to the affected offshore waters.
                 The magnitude and extent of turbidity increases would depend on the hydrographic parameters of the area,
                 nature, and duration of the activity, and bottom-material particle size and composition. Because of the
                 continuous nature of oil and gas activities in the WPA, the frequency of drilling mud and cutting and produced-
                 water discharges is judged to occur nearly continuously throughout these areas. Proposed produced-water
                 discharges will be rapidly diluted within the immediate vicinity of the discharge source. Significant increases
                 in water concentrations of dissolved and particulate hydrocarbons and trace metals are not expected outside
                 the initial mixing zone or the immediate vicinity of the discharge source. Higher concentrations of trace metals,
                 salinity, temperature, organic compounds, and radionuclides, and lower dissolved oxygen may be present near
                 the discharge source. Within the mixing zone of the discharge, long-term effects to water column processes,
                 consisting of localized increases in particulate metal and soluble lower molecular weight hydrocarbons (e.g.,
                 benzene, toluene, and xylenes) concentrations, may be implicated. Trace metals and hydrocarbons associated
                 with the discharge may be deposited within sediments near the discharge point. The proposed discharge of
                 drilling fluids and cutting would encounter rapid dispersion in marine waters. Discharge plumes will be diluted
                 to background levels within a period of several hours and/or within several hundred to 1,000 m of the discharge
                 source. The accumulation of toxic trace metals and hydrocarbons in exposed shelf waters, due to periodic
                 releases of water-based generic muds and cuttings, is unlikely and the long-term degradation of the water










                                                                                                                            IV-395

                column from such discharges is not a major concern. Few effects are anticipated to most water uses from
                routine activities and discharges and then only in an area near the source.
                    Program-related spills will introduce oil into offshore waters and create elevated hydrocarbon levels (up to
                100+ ug/1) within affected waters. After 10 days, much of the oil will be dispersed throughout the water
                column over a period of weeks. Little effect on water use is expected from these spills, and then only in an
                area near the source and slick.


                Conclusion

                    An'identifiable change to the ambient concentration of one or more water quality parameters win be
                evident up to several hundred to 1,000 m from the source and for a period lasting up to several weeks in
                duration in marine and coastal waters. Chronic, low-level pollution related to the proposal will occur
                throughoutthe 35-year life of the proposal.

                High Case Analysis


                Coastal and Estuarine Waters

                    As indicated in the Base Case, it is expected in the High Case scenario that the existing onshore
                infrastructure base in the Gulf is sufficient to support the proposal. Despite this, point and nonpoint source
                discharges (discussed in Section IV.Ac.3.) occurring from existing onshore support facilities may impact coastal
                and nearshore water quality. Most of the onshore OCS support infrastructure located in the WPA exists in
                the Beaumont-Port Arthur, Houston-Galveston, and Corpus Christi areas. In addition, support will come from
                infrastructure located in southwestern Louisiana (Cameron Parish). Waters near support facilities may be
                expected to be contaminated with oily substances and oil-field wastes from point source effluent discharges and
                small chronic spills. For the purpose of this analysis, chronic spills and chronic point source contamination are
                examined together with nonpoint source runoff. It is assumed that approximately 30 spills (greater than one
                bbl and less than 50 bbl) could result in the WPA from activities associated with the proposal. Fewer than 10
                of these spills, primarily in Texas and southwestern Louisiana, are assumed in association with onshore sale-
                related support activities. It is estimated that 75 percent of these smaller spills would range from 1 to 10 bbl
                and occur in association with crude and product transfer operations in port areas. Lower molecular weight
                hydrocarbon compounds (benzene, toluene, etc.) are considered acutely toxic, but are rapidly lost through
                evaporation and dissolution during the first days of a spill (Wheeler, 1978). Normal weathering processes
                encountered by oil spilled in open waters tend to detoxify its components. In shallow areas, oil may become
                entrained in suspended particles and bottom sediments, and subsequently be reintroduced into the water
                column. Given these estimates and the frequent nature of spills over the life of the proposal, the effect of
                chronic contamination on the Gulfs coastal waters due to the proposed action is considered negligible, with
                water characteristics rapidly returning to background levels.
                    Over 19,500 service vessel trips, 22 barge trips, and 171 shuttle tanker trips are estimated to result from the
                proposed action in the WPA. As indicated in Table IV-6, the Calcasieu River and Freshwater Bayou (C-1)
                in Louisiana, and Aransas Pass (W-1), Matagorda Ship Channel (W-1), Houston-Galveston Ship Channel
                (W-2), and Sabine Pass (W-2) in Texas are expected to receive the bulk of sale-related support vessel trips in
                the WPA. Besides barge trips to and from platforms, some barge traffic carrying oil from terminals to other
                terminals or refineries is expected to occur along the Gulf Intracoastal Waterway and adjoining navigation
                channels.
                    Antifouling paints used on support vessels have been shown to have toxic effects on some marine biota.
                Increased loadings within coastal waters of tributyltin and copper compounds contained in antifouling paints
                will take place on a routine basis over the life of the proposal. Ballast and bilge waters from shuttle tankers
                are assumed to be discharged at onshore reception facilities and are not expected to impact coastal water
                quality. While inshore, service vessels are estimated to discharge approximately 3,000 liters of bilge water per
                trip in support of sale-related activities. An estimated 62 million liters (approximately 4,850 liters/day) win be
                discharged into coastal waters from vessels supporting the proposed sale activities. Bilge water may contain










                 IV-396

                 toxic petroleum products and metallic compounds leaked from machinery and could degrade coastal water
                 quality when discharged into confined waters. Given the small concentrations expected and the continuous and
                 widespread nature of the discharges over the life of the proposal, it is expected that there will be some
                 localized, short-term changes (up to several weeks) in water quality characteristics from background levels,
                 depending on the length of the affected channel, flushing rates, etc.
                    No new navigation channels are expected to be dredged as a result of the proposal. However, maintenance
                 dredging of major navigation channels and deepening of some channels to support service vessel traffic are
                 expected. Dredging activities are expected to result in localized impacts (primarily elevated water column
                 turbidities) occurring over the duration of the activity (up to several months). Such activities would preclude
                 some recreational and commercial water uses within the immediate area of this activity. The time periods for
                 expected dredging operations will generally allow for the recovery of affected areas between such activities.
                 Impacts are expected to be somewhat higher in the Mississippi Delta area because of higher sediment inputs.
                 As with the Base Case, it is estimated that no new onshore pipelines will be constructed due to the proposed
                 action. Up to 82 percent of the oil and most of the gas produced will be transported ashore. via the existing
                 onshore pipeline network. Another 17 percent of the oil will be shuttle-tankered ashore. pipelines reduce the
                 need for surface vessel transport of petroleum and the potential for transfer spills. The environmental effects
                 associated with chronic pipeline leakage and malfunction are generally considered small (USDOC, NOAA,
                 1985). Given this and the small percentage of use of the existing pipeline network in support of the proposed
                 activities, impacts from leakage and hydrologic alterations associated with pipelines are considered negligible.
                    As discussed under the Base Case, in addition to those wastes discharged offshore, a number of wastes are
                 brought ashore for disposal. Approximately 872,000 bbl of drilling muds and 64,000 bbI of produced sand from
                 sale-related exploration and production activities would be brought ashore for disposal. In addition, discarded
                 off-field equipment may also pose a potential environmental threat to areas surrounding storage sites, cleaning
                 sites, scrap yards, and metal reclamation yards. Surfaces of production tubing, holding tanks, separators, heater
                 treaters, and other like equipment may be contaminated with scale material containing NORM (Section
                 IV.A.2.d.(5)). The improper storage and disposal of off-field wastes and contaminated off-field equipment
                 would adversely impact surface and ground waters in proximity to disposal facilities, cleaning; sites, and scrap
                 yards. Improper design and maintenance of such storage facilities would result in adverse impacts from
                 elevated levels of radium-226 in surrounding water bodies due to surface runoff (Section IV.A.3.C.(4)).
                   Under the High Case scenario, it is assumed that 1 oil spill greater than or equal to 1,000 bbI would occur
                 from sale-related activities in the WPA_ In addition, I oil spill greater than 50 and less than 1,000 bbl and 30
                 spills greater than 1 and less than or equal to 50 bbl could occur from OCS pipeline, platform, and
                 transportation sources offshore in the WPA_ It is assumed that as much as 75 percent of the original volume
                 of off from the spill source will be lost as a result of weathering processes by the time that the slick contacts
                 these coastal areas. It should be noted that there could be some effects from residual weathered oil that could
                 reach coastal waters following a spill event greater than or equal to 1,000 bbl.        Impacts from low-level
                 contamination were discussed earlier. As indicated, petroleum hydrocarbons introduced into marine and
                 coastal waters may have varied effects depending on the resource impacted, stage of weathering, and local
                 physical and meteorological conditions. Some crude oil components are highly toxic and may cause damage
                 to marine organisms due to the crude's aromatic content. It is expected that normal weathering processes will
                 degrade the oil by breaking down its toxic components. Background levels in the Gulf of Mexico were reported
                 at 0-70 jug/l. In shallow areas, oil may become entrained in suspended particles and bottom sediments,
                 subsequently being reintroduced into the water column. Given these estimates and the frequent nature of spills
                 over the life of the proposal, the effect of hydrocarbon contamination on the Gulfs coastal waters due to the
                 proposed action is considered negligible, with water characteristics rapidly returning to background levels within
                 several days to weeks.

                 Summary

                   All existing onshore infrastructure and associated coastal activities occurring in support of proposed Sale
                 143 will contribute to the degradation of regional coastal and nearshore water quality to a minor extent because
                 each activity provides a low measure of continuous contamination and because discharge locations are










                                                                                                                         IV-397

               widespread, particularly in the Beaumont-Port Arthur, Houston-Galveston, and Corpus Christi areas of Texas
               and the Cameron Parish area of Louisiana. Process, cooling, boiler, and sewage water effluents will be
               discharged due to the use of the existing infrastructure and facilities. No onshore OCS-derived, produced-water
               discharges are assumed for the proposed sale. Wastes and contaminated equipment from offshore will be
               brought ashore for disposal and storage. Adverse impacts could occur to surface and groundwater in proximity
               to improperly designed and maintained disposal sites and facilities. Maintenance dredging is expected to take
               place every one or two years and will result in short-term, low-level impacts to the surrounding waters. The
               OCS-related vessel traffic is estimated to impact water quality through routine releases of bilge and ballast
               waters, chronic fuel and tank spills, trash, and low-level releases of the contaminants in antifouling paints. The
               improper storage and disposal of oil-field wastes and contaminated oil-field equipment would adversely impact
               surface and ground waters in proximity to disposal facilities, cleaning sites, and scrap yards. Surface and
               groundwater in proximity to improperly designed and maintained disposal sites and facilities could be adversely
               impacted with elevated concentrations of arsenic, chromium, zinc, cadmium, mercury, lead, barium, penta-
               chlorophenol, naphthalene, benzene, toluene, and radium.
                 One oil spill greater than or equal to 1,000 bbl and 1 oil spill greater than 50 and less than 1,000 bbl are
               assumed to occur, but not assumed to contact coastal and nearshore waters. An additional 30 spills (greater
               than 1 but less than or equal to 50 bbl) are assumed to result from OCS sale-related activities both in the
               coastal zone and from offshore. Of these, fewer than 10, associated with onshore support and vessel activities,
               are expected to occur in coastal waters. Sale-related spills will introduce off into nearshore waters, creating
               elevated hydrocarbon levels (up to 100+ pg1l) within affected waters. After 10 days, much of the oil will be
               dispersed throughout the water column over a period of weeks. In shallow areas, oil may become entrained
               in suspended particles and bottom sediments. Water uses would be affected for up to several weeks from
               proposed spills and then only near the source of slick. Therefore, the effect of chronic contamination of WPA
               coastal waters due to the proposed sale is considered negligible, with water characteristics rapidly returning to
               background levels.

               Marine Waters

                   Table IV-3 indicates that, under the High Case scenario, the addition of 420 exploration and delineation
               wells, 270 development wells, 30 platforms complexes, and up to 240 krn of pipeline is estimated for the WPA.
               As a result, approximately 305 MMbbI of produced waters, 4.8 MMbbI of drilling muds, 1.16 MMbbI of drill
               cuttings, and 892,000 ml of treated sanitary and domestic wastes may be expected to be generated from the
               proposed action.
                   Immediate effects would be brought about by increased drilling, construction, and pipelaying activities,
               causing an increase in water column turbidities (lasting for hours with mud discharges, to several weeks with
               dredging-pipelaying activities) to the affected offshore waters. Installation of an estimated 240 km of new
               pipelines offshore will result from sale-related activities. Gulfwide, pipeline construction activities may result
               in the resuspension of up to 40,000 M3 of sediment during the life of the proposed program. All burial
               activities will occur in water depths of 200 ft and less. Offshore Subarea W-1 will support all sale-related
               pipeline burial activities and associated sediment resuspension. Pipeline construction activities may result in
               the resuspension of settled pollutants, toxic heavy metals, and pesticides, if present. The magnitude and extent
               of turbidity increases would depend on the hydrographic parameters of the area, nature and duration of the
               activity, and bottom-material size and composition. For the purpose of this analysis, the frequency of activities
               resulting in resuspension of sediment is judged to occur nearly continuously throughout much of the
               northwestern and north-central Gulf of Mexico. However, the severity of impacts would result only in some
               measures of water quality (primarily increased water column turbidities) changing from background levels and
               that in an area within a distance of 1,000 m from the activity.
                   Aside from creating increased water column turbidity, explosive platform removal may adversely impact
               water quality by releasing explosive by-products into the water column upon detonation of charges to sever the
               legs and pilings of a structure. Six platforms associated with the proposal are assumed to be removed by
               explosive methods. The by-products of these events may be gaseous, liquid, or solid, and may be soluble or
               insoluble in water. Virtually all of the products become airborne in the case of a water surface burst (for scare










                  IV-398

                  charges), even from relatively deep explosions. The magnitude and extent of turbidity increases would depend
                  upon several hydrographic parameters, the duration of the activity, and bottom-material sizA., and composition.
                  Because most of the gases are ejected into the air during rig removal (by explosive means), the very small
                  amounts that remain in the water column should either be dissolved or dispersed so rapidly that water quality
                  in the area would not be seriously affected.
                      The discharge of 892,000   M3  of treated sanitary and domestic wastes from the various rigs and platforms
                  will increase levels of suspended solids (14-550 mg/1), nutrients, chlorine, and BOD near the point of discharge.
                  The volume and concentration of such wastes will vary widely over time, occupancy, platform characteristics,
                  and operational situation. Properly operating biological treatment systems at these facilities have effluents
                  containing less than 150 mg/I of suspended solids. These are considered minor discharges and are quickly
                  diluted. The impact to offshore water quality from program-related treated sanitary and domestic waste
                  discharges will be negligible, occurring within a few meters of the discharge source.
                      Up to 304 MMbbI of produced waters are estimated to result from the High Case. Offshore Subareas W-3
                  will receive the greatest number of these discharges (274 MMbbl) over the life of the proposal. According to
                  the findings of numerous investigators (e.g. Mackin, 1973; Gallaway, 1980; Bender et al., 19719; Reid, 1980), the
                  estimate of the expected effects of these discharges on offshore water quality is that the effects will be limited
                  to an area in proximity to the discharge source. Higher concentrations of trace metals, salinity, temperature,
                  organic compounds, and radionuclides, and lower dissolved oxygen may be present near the discharge source.
                  Because of the continuous nature of oil and gas activities in the northwestern and north-central Gulf of Mexico,
                  the frequency of produced water discharges is judged to occur nearly continuously throughout these areas. The
                  assumption, based on the work of the investigators cited and historical data, is that the produced-water
                  discharges resulting from the proposal will be rapidly diluted within the immediate vicinity of the discharge
                  source. Significant increases in water concentrations of dissolved and particulate hydrocarbons and trace metals
                  are not expected outside the initial mixing zone or immediate vicinity of the discharge source. Within the
                  mixing zone of the discharge, long-term effects to water column processes, consisting of localized increases in
                  particulate metal and soluble lower molecular weight hydrocarbons (e.g., benzene, toluene, and xylenes)
                  concentrations, may be implicated. Trace metals and hydrocarbons associated with the discharge may be
                  deposited within sediments near the discharge point.
                      Some 4.8 MMbbI of drilling muds and 1.2 MMbbl of drill cuttings are estimated to result from drilling
                  activities associated with the proposed action. Drilling muds and cuttings are routinely discharged into offshore
                  waters and are regulated by NPDES permits. As with produced water discharges, offshore Subarea W-3 would
                  receive the greatest percentage of these potential discharges. Approximately 4.1 MMbbI of drilling muds and
                  996,000 bbI of cuttings could be generated in offshore Subarea W-3. It is assumed that 18 percent of the
                  drilling muds (872,000 bbl) associated with sale-related activities would be brought ashore for disposal. Some
                  64,000 bbI of produced sands are estimated to be produced in the WPA from the proposed activities.
                  However, these will not be discharged into offshore waters, but rather brought ashore foj'     - disposal. When
                  discharged into the surrounding offshore waters, drilling muds may create turbidity plumes several hundred
                  meters in length. A 1983 NRC study suggests that, for routine oil and gas discharges, the various components
                  measured, including turbidity, are at background levels by a distance of 1,000 in. Ecomar Inc. (1980) indicated
                  that, due to settling and dilution, suspended solid levels and metal concentrations decrease: significantly with
                  distance from the source. As with produced-water discharges, because of the continuous nature of oil and gas
                  activities in the northwestern and north-central Gulf of Mexico, the frequency of drilling mud and cutting
                  discharges is judged to occur nearly continuously throughout these areas. According to the work of the
                  investigators cited and previous monitoring studies, it can be concluded the proposed discharge of drilling fluids
                  and cuttings would encounter rapid dispersion in marine waters. Discharge plumes will be diluted to
                  background levels within a period of several hours and/or within several hundred meters of the discharge
                  source. The accumulation of toxic trace metals and hydrocarbons in exposed shelf watem, due to periodic
                  releases of water-based generic muds and cuttings, is unlikely, and the long-term degradation of the water
                  column from such discharges is not a major concern. Few effects from drilling muds and cutting discharges
                  are expected on water uses, and then only in an area near the source.
                     Crude oils contain thousands of different compounds formed during initial formation. Hydrocarbons
                  account for up to 98 percent of the total composition. Crude oils often contain wide concentrations of the










                                                                                                                            IV-399

                 trace metals nickel, vanadium, iron, sodium, calcium, copper, and uranium. Petroleum hydrocarbons introduced
                 into marine waters may have varied effects on the local biota with impact severity depending on the resource
                 impacted, stage of weathering, and local physical and meteorological conditions. These effects are discussed
                 in greater detail in Section IV.C. Oil released on the surface will be rapidly dispersed by the action of winds
                 and currents, resulting in rapid transport, whereas for a subsurface spill, some of the oil would be distributed
                 throughout the water column. One oil spill greater than or equal to 1,000 bbl, 1 oil spill greater than 50 and
                 less than 1,000 bbl, and approximately 30 spills greater than or equal to 1 bbI and less than or equal to 50 bbI
                 are assumed to occur from program-related activities in the WPA_ In addition, nine spills (diesel and off-based
                 drilling muds) are assumed to occur from drilling and workover activities. The introduction of oil into offshore
                 waters will create elevated hydrocarbon levels (up to 100+ gg/l) within affected waters. Background levels in
                 the Gulf have been reported at 0-70 lAg/l. After 10 days, much of the oil will be dispersed throughoutthe water
                 column over a period of weeks. Little effect on offshore water use is anticipated and then only in an area near
                 the source or stick.


                 Summary
                    Based on analysis of projected sale-related support activities, the estimate is that offshore Subarea W-1
                 would receive the greatest portion of pipeline burial activities, whereas offshore Subarea W-3 would receive
                 the largest amounts of operational discharges. Immediate effects would be brought about by increased drilling,
                 construction, and pipelaying activities, causing an increase in water column turbidities (lasting for several hours
                 with mud discharges, and several weeks with dredging-pipelaying activities) to the affected offshore waters.
                 The magnitude and extent of turbidity increases would depend on the hydrographic parameters of the area,
                 nature and duration of the activity, and bottom-material size and composition. Because of the continuous
                 nature of oil and gas activities in the WPA, the frequency of drilling mud and cutting and produced water
                 discharges is judged to occur nearly continuously throughout these areas. Produced-water discharges resulting
                 from these proposed activities will be rapidly diluted within the immediate vicinity of the discharge source.
                 Significant increases in water concentrations of dissolved and particulate hydrocarbons and trace metals are
                 not expected outside the initial mixing zone or the immediate vicinity of the discharge source. Higher
                 concentrations of trace metals, salinity, temperature, organic compounds,and radionuclides, and lower dissolved
                 oxygen may be present near the discharge source. Within the mixing zone of the discharge, long-term effects
                 to water column processes, consisting of localized increases in particulate metal and soluble lower molecular
                 weight hydrocarbon (e.g., benzene, toluene, and xylenes) concentrations, may be implicated. Trace metals and
                 hydrocarbons associated with the discharge may be deposited within sediments near the discharge point. The
                 proposed discharge of drilling fluids and cuttings would encounter rapid dispersion in marine waters. Discharge
                 plumes will be diluted to background levels within a period of several hours and/or within several hundred
                 meters of the discharge source. The accumulation of toxic trace metals and hydrocarbons in exposed shelf
                 waters, due to periodic releases of water-based generic muds and cuttings, is unlikely, and the long-term
                 degradation of the water column from such discharges is not a major concern. Few effects on most water uses
                 from routine activities and discharges are expected, and then only in an area near the source.
                     Program-related spills will introduce oil into offshore waters and create elevated hydrocarbon levels (up
                 to 100+ ug/1) within affected waters. Much of the oil will be dispersed throughout the water column over
                 several days to weeks. Little effect on water use is anticipated from these spills, and then only in an area near
                 the source and slick.


                 Conclusion


                     As a result of the proposal, an identifiable change to the ambient concentration of one or more water
                 quality parameters will be evident up to several hundred to 1,000 in from the source and for a period lasting
                 up to several weeks in duration in marine and coastal waters. Chronic, low-level pollution related to the
                 proposal will occur throughout the 35-year life of the proposal.










                 IV-400

                 (4) Impacts on Air Quality

                     This discussion analyzes the potential degrading effects on air quality by the activities and developments
                 induced by the proposed sale. The following activities will potentially degrade air quality: platform emissions;
                 drilling activities during exploration, delineation, and development; service vessel operation; evaporation of
                 volatile hydrocarbons from surface oil slicks; and fugitive emissions during hydrocarbon venthig and offloading.
                 Sections presenting supporting materials and discussions are Sections III.A.2. and 3. (description of Gulf of
                 Mexico meteorology and coastal counties air quality status), IV.C.l. (oil-spill assumptions), and IV.A.2.d.(6)
                 (air emissions).
                     The parameters of this analysis are the emission factors, surface winds, stability of the overlaying air
                 column, and the height of the atmospheric mixed layer.
                     Emissions of certain primary pollutants are known to be detrimental to health and welfare. Nitrogen oxide
                 and nitrogen dioxide comprise NO. emissions. Nitrogen oxide is important because it can be converted into
                 nitrogen dioxide, which can be poisonous. Nitrogen dioxide reacts with water to form nitric acid, which is
                 harmful to vegetation and construction materials. Further, nitrogen dioxide is involved in photochemical
                 reactions that yield ozone, which has significant effects on the atmosphere and the global cU[mate and causes
                 respiratory problems. Carbon monoxide (CO) is a toxic gas that reacts with hemoglobin in the blood and
                 blocks the transfer of oxygen to the body. Carbon monoxide increases cardiovascular diseases, affects the
                 central nervous system, and contributes to the global climate cycle. Sulfur oxides (SO.) can combine with water
                 and oxygen to form very corrosive and irritating acids. These sulphur compounds produce aerosols that act
                 as nuclei for rain, which removes sulphur from the atmosphere. Further, a correlation has been found between
                 SO, and respiratory diseases such as bronchitis. Volatile organic compounds (VOC), or hydrocarbons, are
                 poisonous to humans at very high concentrations only, cause eye irritation, and play important roles in
                 atmospheric photochemical cycles. Particulate matter has a trimodal distribution, and particles that are smaller
                 than 10 microns (PM10) are detrimental to visibility and may cause respiratory problems. The visibility
                 reductions are caused primarily by particle scattering and by light absorption to a lesser extent This analysis
                 considers mainly total particulate matter (TSP).
                     Ozone is a secondary pollutant and "is one of the most toxic regulated pollutants under ambient air quality
                 standards" (Godish, 1991, p. 159). It is formed by photochemical reactions involving some of the primary
                 pollutants. Ozone is important to the global climate and causes damage to plants and agricultural crops. At
                 concentrations of 196-784 11gM-3 and exposures of 1-2 hours, it also affects lung functions. These effects are
                 transient and include reduction of tidal volume, increased respiration rates, increased pulmonary resistance,
                 and changed respiration mechanics (Godish, 1991). Ozone can interfere with or inhibit the immune system.
                     Emissions of primary pollutants will occur during exploration, development, and production activities.
                 Typical emissions for exploratory and development drilling activities are presented in Section IV.A.2.d.(6).
                     The above values show that emissions of NO. are between 4 and 34 times greater than emissions for other
                 pollutants during drilling activities. Statistics of wells drilled between 1985 and 1990 show an average hole
                 depth of 10,318 ft and a drilling period of 33 days. These values are similar to the values of hole depth and
                 drilling period employed in calculating typical emissions from wells, above.
                     Platform emissions for the Gulf of Mexico region (Section IV.A-2.d.(6)) show NO            VOC, and CO
                 emissions about three orders of magnitude larger than emissions of SO. and TSP. The NO,,, VOC, and CO
                 emissions seem to be about 10 times greater than emissions from exploratory wells. This discrepancy, however,
                 is just a mathematical artifact, because well rates are based on a 45-day period while platform rates are on a
                 yearly basis. Emission rates during exploration are higher than emission rates during production. Emission
                 factors for other activities, such as helicopters, tankers, loading, and transit operations, were obtained from
                 Jacobs Engineering Group, Inc. (1989) and USEPA (1985).
                     Other sources of primary pollutants are accidents, such as oil spills and blowouts, related to OCS
                 operations. Typical emissions from OCS accidents consist of hydrocarbons; only blowouts with fires produce
                 other primary pollutants. Even though the emissions rates are large, pollutant input to the almosphere is not
                 large because large rates cannot be sustained for long periods. Observe that emission rates decreased
                 approximately 50 percent by the second hour.










                                                                                                                           IV-401

                   Once pollutants are released into the atmo       sphere, transport and dispersion processes start acting.
               Transport processes of pollutants are carried out by the net wind circulation. The mean wind circulation is
               discussed in Section III.A.2. During summer the wind regime in the WPA is predominantly onshore at mean
               speeds of 4 to 6 ms-1. Winter wind circulation is predominantly onshore also at mean speeds of 4 to 5 ms".
                   Pollutant dispersion or mixing depends on emission height, atmospheric stability, and mixed layer height.
               The emission height of platforms of the Gulf of Mexico is determined by storm wave heights, storm tides, and
               a safety factor. For water depths between 10 and 200 in, calculated emission heights are between 31 and 35
               m, well inside the mixed layer. For emissions inside the atmospheric boundary layer, the heat flux, which
               includes effects from wind speed and atmospheric stability (via air-sea temperature differences), is a better
               indicator of turbulence available for dispersion (Lyons and Scott, 1990). Heat flux calculations in the WPA
               (USDOI, MMS, 1988c) indicate an upward flux year-round, being highest during winter and lowest in summer.
               The atmospheric stability along WPA coastal areas of the Gulf of Mexico, discussed in Section III.A.2., is either
               neutral or stable more than 75 percent of the time. Atmospheric stability is also important because it helps
               to distribute and diffuse the available energy or momentum of the atmosphere.
                   A mechanism in part responsible for this distribution is buoyancy. It is well known that air density is
               inversely proportional to temperature. When the sea surface is warmer than the overlying air, the sea heats
               that air in contact with it. The warmer air becomes lighter, starts to rise, and is replaced by cooler air from
               above. The rising air acquires a vertical velocity that, when multiplied by its density, becomes a flux of vertical
               momentum by buoyancy or density difference. Vertical momentum flux can also occur because of mechanically
               generated turbulence, which is totally unrelated to density differences.
                   The mixing height is very important because it determines the space available for spreading the pollutants.
               Although mixing height information throughout the Gulf of Mexico is scarce, measurements near Panama City
               (Hsu, 1979) show that the mixing height can vary between 400 and 1,300 m, with a mean of 900 in. The mixing
               height tends to be higher in the afternoon, more so over land than over water. Further, the mixing height tends
               to be lower in winter, and daffy changes are smaller than in summer.

               Base Case Ana4wis

                   The scenario discussed in Section IV.A- (Table IV-3) for the 35-year life of the proposed action establishes
               that 210 exploration and delineation and 110 development wells would be drilled, and 10 platform complexes
               would be emplaced. The sale area has been subdivided into three offshore subareas: W-1, W-2, and W-3
               (Figure IV-1). Table IV-3 presents the numbers of exploration, delineation, and development wells; platforms
               installed; and service-vessel trips for the proposed action in each subarea. The information presented below
               shows total emissions from wells, platforms, vessels, and other activities in the WPA during the proposed action.
               Observe that NO,, still is the most emitted pollutant, while TSP is the least emitted. More important is that
               this information shows that wells contribute mostly NO,,, platforms contribute mostly NO. CO, and VOC, while
               vessels are contributors of all pollutants. These emissions were calculated by adding the well and platform
               emissions over the 35-year life of the proposed action. Vessel emissions were calculated using the total number
               of service-vessel trips presented in Table IV-3. Emissions from other related activities were calculated using
               information also presented in Table IV-3.










                  IV402


                                                         Total OCS Emissions in the WPA
                                                   (tons over 35-year life of the proposed action)


                                    Activi                        NO.,           CO            SO             THC ,         TSP

                      Service Vessels                            2,797.4        7,327.7          44.2           142.4        197.4
                      LTO Helicopters                               14.2          11.5           2.2             0.6           0.5
                      Cruise Helicopters                            45.8         131.0           9.8            10.7          13.1
                      Blowouts without Fire                          0.0           0.0           0.0             0.2           0.0
                      Spills without Fire                            0.0           0.0           0.0             0.0           0.0
                      Barge Loading                                  0.0           0.0           0.0            12.4           0.0
                      Tanker Loading                                 0.0           0.0           0.0            210.6          0.0
                      Transit Loss                                   0.0           0.0           0.0            168.2          0.0
                      Tanker Exhaust                              150.8           16.5         187.3             0.2          54.2
                      Tug Exhaust                                   16.3           1.6           0.2             0-3           1.0
                      Exploratory Wells                          2,030.7         541.8         237.3            58.8         203.7
                      Development Wells                           930.8          248.3         109.2            273           93.6
                      Platforms                                 17,150.0        2,234.0          30.0         6,500.0         42.0
                      Totals                                    23,136.0        3,512.4        620.2          7,131.2        605.5
                          Total emissions for each subarea in the WPA         during the proposed     action are presented below.
                 Observe that Subarea W-1, which is the closest to land, would generate the smallest emissions of all pollutants,
                 while Subarea W-3, the farthest from land, would generate the greatest amounts of emissions.

                                                          WPA Subareas Total Emissions
                                                (tons over the 35-year life of the proposed action)


                                      Pollutant                W-1                W-2                  W-3

                                         NO.                 2,313.6             4,627.2              16,195.2
                                          CO                   351.2              702.5               2,458.7
                                          So,,                   62.0             124.0                434.1
                                         THC                   713.2             1,426.4              4,992.5
                                         TSP                    60.6              121.1                423.9
                      The total pollutant emissions per year are not uniform. During the early years of the proposed action,
                 emissions would be small but increase over time with production. After reaching a maximum, emissions would
                 decrease rapidly to zero as all platforms and wells are removed and service vessels trips are no longer needed.
                      The peak emissions in tons per year for the primary pollutants during the proposed action are indicated
                 below. It is very important to note that well drilling activities and platform complex peak emissions are not
                 necessarily simultaneous, so the combined maximum emissions are not a simple addition of the individual peak
                 emissions. However, it is assumed that service vessel and well and platform peak emissions occur
                 simultaneously. In this analysis the aggregate peak emissions, which are two to five times the mean emissions,
                 will be employed. Use of the peak emissions will provide the most conservative estimates of impact levels to
                 the onshore air quality.











                                                                                                                          IV-403


                                                    Peak and Mean Emissions in the WPA
                                              (tons over the 35-year life of the proposed action)

                    Pollutant        Wells         Platforms        Vessels          Others          Mean         Aggregate

                       NO.           374.25          857.50          86.41            0.00         661.03          1,001.41
                       CO            99.85            111.70          13.95           0.00         100.35            152.65
                       so.           43.75              1.50           6.96           0.00           17.72            50.16
                      THC            10.85            325.00           4.42           11.86        204.45            342.28
                       TSP           37.55              2.10           7.61           0.00            17.30           44.81

                    The mean emissions were computed by dividing the total emissions by the 35-year life of the proposed
                action. Peak emissions from wells and platforms are obtained from their temporal distribution. Observe that
                platforms and wells have the greatest peak emissions, while vessels have smaller emissions. This is contrary
                to the emission rates, where wells have greater emission rates than platforms.
                    To estimate the potential impact of offshore emissions on offshore and onshore air quality, a steady state
                box model (Lyons and Scott, 1990) was employed. The model is an expression of mass conservation and
                assumes that pollutants are vertically dispersed and sources uniformly distributed. For the purpose of these
                air quality analyses, an assumption of uniform distribution of average size sources throughout the planning
                areas at this stage is a reasonable approach. Predominance of unstable atmospheric conditions over the sea,
                as discussed in Section III.A.2., ensures that pollutants are dispersed homogeneously. The model was applied
                to NO. emissions because these are the largest emissions. Concentrations for other pollutants can be estimated
                by multiplying the NO. concentrations by the ratio of the pollutant emissions over the NO., emissions. These
                concentrations are [COI=0.152[NO.1; [SO.1=0.050[NO.1; and ITSP]=0.333[NO.J. Notice that concentrations
                of primary pollutants other than NO,, would be smaller by more than 80 percent. Because VOC emissions
                are not inert, the box model cannot be used to assess their impacts on air quality. Impacts from VOC and CO
                will be estimated by comparing the offshore and onshore emission rates.
                    The box model was applied to the following conditions: onshore and offshore winds with speeds ranging
                from 1 to 7 ms-1; a mean mixing height of 900 m; and a low mixing height of 300 m. During periods of winds
                blowing offshore, impacts to the onshore air quality from offshore WPA emissions are very low because the
                pollutants are transported offshore. Conditions of onshore winds indicate that concentrations reaching land
                from Subarea W-1 varied between 0.24 and 0.05 /igm-3 for speeds from I to 7 ms-1 and a mixing height of 900
                m; for a 300-m mixing height, concentrations varied from 0.72 to 0.10 LgM-3 under the same wind speeds.
                    Concentrations for pollutants other than VOC would be smaller, as indicated above. The MMS regulations
                (30 CFR 250.44) do not establish annual significance levels for CO and VOC. For these pollutants, a
                comparison of emission rates will be used to assess impacts. Formulas to compute the emission rates in tons/yr
                for CO are 3,400-D2/3 and 33.3-D for VOC. In these formulas, D represents distance in statute miles from the
                shoreline to the source. The CO exempt emission level in Subarea W-1 is 15,781.4 tons/yr, which is greater
                than peak emissions from the whole WPA- The exemption emission level of VOC in Subarea W-1 is 333
                tons/yr, while the aggregate emissions level is estimated as 342.28 tons/yr. Transport of pollutants toward
                onshore areas has a maximum frequency of 85 percent during summer and only 34 percent during winter.
                Thus, the box model results are very conservative estimates of pollutant contributions to the onshore air quality
                status. The modeling effort does not consider removal processes such as rain, which in the WPA has a high
                frequency (Section III.A.2.) and would reduce impact levels to onshore air quality.
                    Using the OCD Model (USDOI, MMS, 1986a), MMS has also studied the impacts of NO, offshore
                emissions. Conducted off the Galveston, Brazos, and High Island Areas, Texas, the study used 250 offshore
                sources and employed a 300-m mixing height, which coincides with the lower mixing height employed in the
                box model. The model run in this study represents an aggregation of all sources. The annual arithmetic mean
                varied between 0.01 and 0.19 /jgM-3' which is below the N02 national standard of 100 AgM-3. All other inert
                pollutants would have lower concentrations.
                    A recent dispersion analysis of NO. emissions from 16 proposed OCS platforms along the Texas offshore
                area was completed (USDOI, MMS, 1991c). Annual average concentrations peaked around 0.04 pgm-3 and










                   IV-404

                   the highest 1-hour concentration never exceeded 1.54jugm-3. These results agree with our previous assessments
                   that the proposed action will have low impacts on the onshore air quality. Therefore, it is reasonable to assume
                   that concentrations derived from emissions associated with the proposed action, 20 platforms spread over 145.3
                   billion square meters, would have a much smaller effect.
                       Oil-spill effects on air quality are examined below. It is assumed that oil spills in the category greater than
                   I and equal to or less than 50 bbl, as well as greater than 50 and less than 1,000 bbl, would have low impacts
                   on air quality degradation because their input of pollutants (it is assumed that 30% of the spin evaporates in
                   three days) would be very small. Information from OCS accidents indicates emissions of fewer than 100
                   tons/hour by the second hour. For spills greater than or equal to 1,000 bbl, emissions are about 285 tons/hour
                   or smaller. But no impacts from spills greater than or equal to 1,000 bbI will occur because it is assumed that
                   no oil spill greater than or equal to 1,000 bbI will occur in the WPA during the proposed action. If the
                   dispersion of emissions is taken into account, effects on offshore air quality would be teMporary.
                       Nearly 18 percent of OCS crude-oil production is offloaded from surface vessel-; at ports. The
                   unintentional emissions from these offloading operations are estimated as 223 tons for the Base Case over the
                   35-year life of the proposed action. This represents 3.1 percent of the total VOC emissions. Emissions from
                   service vessels are expected to produce negligible effects on air quality.
                      Suspended particulate matter is important because of its potential in degrading the visibility in national
                   wildlife refuges or recreational parks, designated as PSD Class I areas. The impact depends on emission rates
                   and particle size. Particle size used in this analysis represents the equivalent diameter, which is the diameter
                   of a sphere that will have the same settling velocity as the particle. Particle distribution in the atmosphere has
                   been characterized as being largely trimodal (Godish, 1991), with two peaks located at diameters smaller than
                   2,um and a third peak with a diameter larger than 2 jAm. Particles with diameters of 2 gni or larger settle very
                   close to the source (residence time of approximately 1/2 day, Lyons and Scott, 1990), so their concentration on
                   these areas would be low. For particles smaller than 2 gm, which do not settle fast, wind transport determines
                   their impacts. Results from the box model indicate that the largest concentration for TSP Nvill be 0.24,UgM-3,
                   which is less than the allowable annual increase level of 5 Agni-3. Section III.A.3. indicates that in coastal areas
                   the PM10 is around 50 AgM-3 and the national standard is 150 Agin-3, making the OCS contribution unimportant.
                   Therefore, matter would have a low impact on the visibility of PSD Class I areas.
                      Blowouts are accidents related to OCS activities and are defined as an uncontrolled flow of fluids from a
                   wellhead or wellbore. In the Gulf of Mexico OCS there have been 116 blowouts over a period of 19 years
                   (1971-1989) (Section 1V.A_2.d.(8)). This represents an average of about 6 blowouts per year, but the number
                   of wells drilled is a better indicator. The estimated number of blowouts, at a rate of 7 blowouts per 1,000 wells
                   drilled, is 2 blowouts during the proposed action in the WPA. The air pollutant emissions from blowouts
                   depend on the amount of oil and gas released, duration of the accident, and the occurrence or not of fire
                   during the blowout.
                      Because of technological advances the duration of blowouts has decreased, and about 61 percent of recent
                   blowouts last 1 day or less, 19 percent last between 2 and 3 days, 7 percent last between 4 and 7 days, and 13
                   percent last more than 7 days (Fleury, 1983). Further, most blowouts occurred without fire (MMS Database).
                   The amount of oil released during these accidents has been small. The total emission of THC is 24 tons over
                   the life of the proposed action. It must be remembered that these are conservative estimates and that the total
                   amount of THC may be less; the VOC will also be less because it is a fraction of the THC.
                      Ozone is of great concern because of its environmental considerations. In the WPA five counties have
                   nonattainment status for this pollutant (Section III.A3.). Ozone measurements (Texas Aj[r Control Board,
                   1989) in 1988 were discussed in Section III.A.3. and details can be found therein. Concentrations at three
                   coastal sites indicate that the national standard was exceeded in two (Houston and the Beauniont-Port Arthur-
                   Brazoria area) and the third was a border case (Corpus Christi). However, impacts from the OCS cannot be
                   assessed because ozone is not emitted but formed by photochemical processes, which were not modeled in this
                   analysis. However, the NO. concentrations, even if all were converted to ozone, will not change the status of
                   the areas discussed above. Recently, MMS awarded one study to do a preliminary ozone exercise with USEPA
                   using the Regional Oxidant Model (ROM) for episodes with onshore transport. A second study is near award
                   for a 3-year study of ozone formation and transport ftom OCS activities in the Gulf of Memico.










                                                                                                                            IV-405


                 Summary

                    Emissions of pollutants into the atmosphere from the activities associated with the proposed action are
                 estimated to have minimal effects on offshore air quality because of the prevailing atmospheric conditions,
                 emission heights, and pollutant concentrations. Effects on air quality from emissions from OCS activities in
                 onshore areas is expected to be small because of the atmospheric regime, the emission rates, and the distance
                 of these emissions from the coastline. The above discussion is based on average conditions; however, there
                 will be days of low mixing heights and wind speeds that could increase impacts. These conditions are
                 characterized by fog formation, which in the Gulf occurs about 35 days a year, mostly during winter. Impact
                 from these conditions is reduced in winter because the onshore winds have the smallest frequency, and rain
                 removal is greatest.

                 Conclusion

                     Emissions of pollutants into the atmosphere from activities for the proposed action are expected to have
                 concentrations that would not change the onshore air quality classifications.             Increases in onshore
                 concentrations of air pollutants from the proposed action are estimated to be about 1 AgM-3 (box model steady
                 concentrations). This concentration will have minimal impacts during winter because onshore winds occur only
                 about 34 percent of the time and maximum impacts in summer, when onshore winds occur 85 percent of the
                 time.


                 High Case Analysis

                     The scenario discussed in Section W.A. (Table IV-3) for the High Case establishes that 420 exploration
                 and delineation wells and 270 development wells would be drilled, and 30 platform complexes would be
                 emplaced. The sale area has been subdivided into three offshore subareas: W-1, W-2, and W-3 (Figure IV-1).
                 This discussion analyzes the potential degrading effects on air quality of OCS-related activities in each subarea.
                 Table IV-3 presents for the High Case the numbers of exploration, delineation, and development wells;
                 platforms installed; and service vessel trips for each subarea.
                     The following table shows total emissions from wells, platforms, and vessels in the WPA for the High Case.
                 Observe that NO, is the most emitted pollutant, while TSP is the least emitted. More important is that this
                 information shows that wells and vessels contribute mostly NO,@ platforms contribute mostly NO           CO, and
                 VOC. These emissions were calculated by adding the well and platform emissions over time. Vessel emissions
                 were calculated using the total number of service vessel trips presented in Table IV-3. Emissions from other
                 related activities were calculated using information presented in Table IV-3 and emission factors from Jacobs
                 (1989) or USEPA (1985).










                IV406


                                                       Total OCS Emissions in the WPA
                                                (tons over 35-year life of the proposed action)

                         Acthft                                 NO            CO            so            THC             TSP

                    Service Vessels                           6,572.2         769.9        103.8           334.41       463.7
                    LTO Helicopters                               40.6         32.8           6.3            1.7           1.6
                    Cruise Helicopters                          131.3         375.0          28.1            30.6         37.5
                    Blowouts without Fire                         0.0           0.0           0.0            0.5           0.0
                    Spills without Fire                           0.0           0.0           0.0          255.0           0.0
                    Barge Loading                                 0.0           0.0           0.0           32.' 2         0.0
                    Tanker Loading                                0.0           0.0           0.0          547.6           0.0
                    Transit Loss                                  0.0           0.0           0.0          437.1           0.0
                    Tanker Exhaust                              390.7          42.7        485.3             0.6        140.4
                    Tug Exhaust                                   39.8          4.0           0.5            1.8           2.4
                    Exploratory Wells                         4,061.4       1,083.6        474.6           117.6        407.4
                    Development Wells                         1,790.0         477.5        210.0             52.5       180.0
                    Platforms                                51,450.0       6,762.0          90.0       19,500.0        126.0

                    Totals                                   64,476.0       9,547.5        1,398.6      21,31 I.S'     1,359.0

                    Total emissions for each subarea in the WPA during the High Case are presented below. Observe that
               Subarea W-1, which is the closest to land, generates the smallest emissions of all pollutants, while Subarea W-3,
               the farthest from land, generates the greatest amounts of emissions.

                                                      Total Emissions in WPA Subareas
                                        (tons over the 35-year life of the proposed action--High Case)


                                    Pollutant               W-1                W-2                   W-3

                                        NO,,               2,149.2          10,746.0             51,580.8
                                        CO                   318.3            1,591.3             7,638.0
                                        so.                   46.6             233.1              1,118.9
                                       THC                   710.4            3,552.0            17,049.4
                                        TSP                   45.3             226.5              1,087.2

                    The total pollutant emissions per year are not uniform. During the early years of the proposed action,
               emissions would be small and increase over time with production. After reaching a maximum,e missions would
               decrease rapidly to zero as all platforms and wells are removed and service vessel trips are no longer needed.
                    The following table presents the peak emissions in tons per year for the primary pollutants during the High
               Case. It is very important to note that well drilling activities and platform peak emissions are; not necessarily
               simultaneous. However, it is assumed that emissions from service vessels and other activities and well and
               platform peak emissions occur simultaneously. In this analysis the aggregate peak emissions, which are two
               to four times the mean emissions, will be employed. Use of peak emissions will provide the most conservative
               estimates of impact levels to the onshore air quality.










                                                                                                                         IV-407


                                                   Peak and Mean Emissions in the WPA
                                                                  (tons/year)

                    Pollutant         Wells       Platforms         Vessels         Others         Mean          Aggregate

                       NO,,          909.64        2,572.50        204.99            0.00        1,842.17        2,849.09
                       Co            242.69          335.10         34.98            0.00          272.79          389.18
                       So,,          106.36            4.50         17.83            0.00           39.96          116.73
                      THC             26.39          975.00         10.55            40.29         612.84        1,027.93
                       TSP            91.28            6.30         18.45            0.00           38.83          103.75

                    The mean emissions were computed by dividing the total emissions by the 35-year life of the proposed
                action. Peak emissions from wells and platforms are obtained from their temporal distribution. Platforms and
                wells have the greatest peak emissions, while vessels have smaller emissions. This phenomenon is contrary to
                the emission rates, where wells have greater rates than platforms.
                    The effects of the pollutants considered in this analysis were described in the Base Case analysis and will
                not be repeated here. The reader may consult that section.
                    Because the meteorological conditions described in the Base Case will not change for this analysis, neither
                will they be repeated. The only changes that occur in the High Case are those related to infrastructures and
                resources. These changes are reflected in an increase of emissions for all analyzed pollutants. A comparison
                of High Case emissions per year with those of the Base Case shows that these would increase by 1.5 to 2 times.
                    To estimate the potential impact of offshore emissions on offshore and onshore air quality, a steady state
                box model (Lyons and Scott, 1990) was employed. The model is an expression of mass conservation and
                assumes that pollutants are vertically dispersed and sources uniformly distributed. For the purpose of these
                air quality analyses, an assumption of uniform distribution of average size sources throughout the planning
                areas at this stage is a reasonable approach. Predominance of unstable atmospheric conditions over the sea,
                as discussed in Section III.A-2., ensures that pollutants are dispersed homogeneously. The model was applied
                to NO. emissions because these are the largest emissions. Concentrations for other pollutants can be estimated
                by multiplying the NO. concentrations by the ratio of the pollutant emissions over the NO. emissions.
                Concentrations of primary pollutants other than NO. would be smaller by more than 80 percent. Because
                VOC emissions are not inert, the box model cannot be used to assess their impacts on air quality. Impacts
                from VOC and CO will be estimated by comparing the offshore and onshore emission rates.
                    The box model was applied to the following conditions: onshore and offshore winds with speeds ranging
                from 1 to 7 ms-1, a mean mixing height of 900 in, and a low mixing height of 300 in. During periods of winds
                blowing offshore, impacts to the onshore air quality from offshore WPA emissions are very low because the
                pollutants are transported offshore. Conditions of onshore winds indicate that concentrations reaching land
                from Subarea W-1 varied between 0.75 and 0.10jugm-1 for speeds from I to 7 ms-1 and a mixing height of 900
                m; for a 300-m mixing height, concentrations varied from 2.24 to 0.30 ligm-3 under the same wind speeds.
                    Concentrations for pollutants other than VOC would be smaller, as indicated above. Impacts to air quality
                from NO. are low because the only ambient concentration reported (94 11gin-3) was below the national standard
                (100 tkgin-3), and the OCS contribution will not cause it to exceed. The MMS regulations (30 CFR 250.44) do
                not establish annual significance levels for CO and VOC. For these pollutants, a comparison of emission rates
                will be used to assess impacts. Formulas to compute the emission rates in tons/yr for CO are 3,400-Dm and
                33.3-D for VOC. In these formulas, D represents distance in statute miles from the shoreline to the source.
                The CO exempt emission level in Subarea W-1 is 15,781.4 tons/yr, which is greater than peak emissions from
                the whole WPA. The exemption emission level of VOC in Subarea W-1 is 333 tons/yr, while the platform
                emission level is estimated at 32.5 tons/yr. Transport of pollutants toward onshore areas have a frequency
                maximum of 85 percent during summer and only 34 percent during winter. Thus, the box model results are
                very conservative estimates of pollutant contribution to onshore air quality. The modeling effort does not
                consider removal processes such as rain, which in the WPA has a high frequency (Section IIIA2.) and would
                reduce impact levels to onshore air quality.










                 IV408

                     Further, using an approved numerical model, the OCD Model (USDOI, MMS, 1986a), IVIMS has further
                 studied the impacts of offshore emissions. Conducted off the Galveston, Brazos, and High Island Areas, Texas,
                 the study used 250 offshore sources and employed a 300-m mixing height, which coincides with the lower mixing
                 height employed in the box model. The model run in this study represents an aggregation of all sources. The
                 annual arithmetic mean varied between 0.82 and 1.83 AgM-3' which is below the national standard of 100
                 Agrn-3. All other inert pollutants will have lower concentrations.
                     A recent dispersion analysis of NO. emissions from 16 proposed OCS platforms along the Texas offshore
                 area was completed (USDOI, MMS, 1991c). Annual average concentrations peaked around 0.04 AgM-3 and
                 the highest 1-hour concentration never exceeded 1.54,UgM-3. These results agree with our pre,%rious assessments
                 that the proposed action will have low impacts on the onshore air quality. Therefore, it is reasonable to assume
                 that concentrations derived from emissions associated with the proposed action, 30 platforms spread over 145.3
                 billion square meters, would have a much smaller effect.
                     Oil-spill effects on air quality are examined below. It is assumed that oil spills in the category greater than
                 I and equal to or less than 50 bbl, as well as greater than 50 and less than 1,000 bbl, would have low impacts
                 on air quality because their input of pollutants (it is assumed that 50% of the spill evaporates in three days)
                 would be very small. Information from OCS accidents indicates emissions of fewer than 100 tons/hourby the
                 secondhour. For spills greater than or equal to 1,000 bbl, emissions are about 285 tons/houror smaller. A
                 single spill greater than or equal to 1,000 bbl is assumed as a result of the High Case. If the dispersion of
                 emissions is taken into account, effects on offshore air quality would be temporary.
                     Nearly 18 percent of OCS crude-oil production is offloaded from surface vessels at ports. The estimated
                 VOC emissions during offloading are 579.8 tons during the 35-year life of the proposed action. These emissions
                 represent 2.7 percent of the total VOC emissions of the High Case. Current industry practice is to extend
                 pipelines to new production facilities when feasible; barging, then, would be needed only during the
                 construction phase. Emissions from service vessels are expected to produce negligible effects on air quality.
                     Suspended particulate matter is important because of its potential in degrading the visibility in national
                 wildlife refuges or recreational parks designated as PSD Class I areas. The impact depends on emission rates
                 and particle size. Particle size used in this analysis represents the equivalent diameter, which is the diameter
                 of a sphere that will have the same settling velocity as the particle. Particle distribution in the atmosphere has
                 been characterized as being largely trimodal (Godish, 1991), with two peaks located at diameters smaller than
                 2 Am and a third peak with a diameter larger than 2 Am. Particles with diameters of 2 Am or larger settle very
                 close to the source (residence time of approximately 1/2 day, Lyons and Scott, 1990), so their concentrations
                 on these areas would be low. For particles smaller than 2 Am, which do not settle fast, wind transport
                 determines their impacts. Results from the box model indicate that the largest concentration for TSP will be
                 0.78 Agm-3, which is less than the allowable annual increase level of 5 ggm-1. Besides, Section III.A.3. indicates
                 that in the coastal areas the suspended particulate matter is around 50 AgM-3 and the national' 24-hour standard
                 is 150 AgM-3, making the OCS contribution unimportant.
                     Blowouts are accidents related to OCS activities and are defined as an uncontrolled flow, of fluids from a
                 wellhead or wellbore. In the Gulf of Mexico OCS there have been 116 blowouts over a period of 19 years
                 (1971-1989) (Section IV.A.2.d.(8)). This represents an average of about 6 blowouts per year, but the number
                 of wells drilled is a better indicator. The estimated number of blowouts, at a rate of 7 blowouts per 1,000 wells
                 drilled, is 5 blowouts during the High Case in the WPA. The air pollutant emissions from blowouts depend
                 on the amount of oil and gas released, the duration of the accident, and the occurrence or not of fire during
                 the blowout.
                     Because of technological advances the duration of blowouts has decreased, and about 61 percent of recent
                 blowouts last 1 day or less, 19 percent last between 2 and 3 days, 7 percent last between 4 and 7 days, and 13
                 percent last more than 7 days (Fleury, 1983). Further, most blowouts occurred without fire (MMS Database).
                 The amount of oil released during these accidents has been small. For this analysis, a blowout of 500 bbl per
                 day will be assumed. Using the distribution of blowouts cited earlier, three blowouts will last 1 (lay, one blowout
                 will last 2.5 days, and one blowout will last 5.5 days. No statistics exist on the amount of gas released during
                 a blowout; however, for this analysis, a rate of 1 Bcf-per-day will be assumed. The emission rate for a blowout
                 without fire is 2,000 lb per hour of THC for a 1,000 bbl-per-day and I Bcf-per-day blowout accident. Using
                 our assumption of oil released, we estimate the rate could then be reduced by half, or 1,000 lb per hour of










                                                                                                                             IV-409

                 THC. The total emission of THC is 138 tons over the life of the proposed action. It must be remembered
                 that these are conservative estimates and that the total amount of THC may be less; the VOC will also be less
                 because it is a fraction of the THC.
                      Ozone is of great concern because of its environmental considerations. In the WPA five counties have
                 nonattainment status for this pollutant (Section Ill.k3.). Ozone measurements (Texas Air Control Board,
                 1989) made in 1988 were discussed in Section III.A.3., to which the interested reader is referred.
                 Concentrations at three coastal sites indicate that the national standard was exceeded in two (Houston and the
                 Beaumont-Port Arthur-Brazoria area) and the third was a border case (Corpus Christi). However, impacts
                 from the OCS cannot be assessed because ozone is not emitted but formed by photochemical processes, which
                 were not modeled in this analysis. However, the NO,, concentrations, even if all were converted to ozone, will
                 not change the status of the areas discussed above.
                      Emissions of pollutants into the atmosphere from the activities associated with the High Case are expected
                 to have a minimal impact on offshore air quality because of the prevailing atmospheric conditions and emission
                 heights. The effects on inshore areas of pollutants from subareas far from the coastline are expected to be low
                 at all times; subareas close to the coastline will have low impacts throughout the year. However, it seems that
                 VOC emissions could pose a problem to the onshore areas of the WPA from the High Case.

                 Conclusion

                      Emissions of pollutants into the atmosphere from activities for the High Case are expected to have
                 concentrations that would not change the onshore air quality classifications.              Increases in onshore
                 concentrations of air pollutants from the High Case are estimated to be about 1 ggm-3 (box model steady
                 concentrations). This concentration will have minimal impacts during winter because onshore winds occur only
                 about 34 percent of the time and maximum impacts in summer, when onshore winds occur 85 percent of the
                 time. However, these concentrations will be reduced by rain removal, which is high through most of the year.

                 (5) Impacts on Marine Mammals

                 (a) Nonendangered and Nonthreatened Species

                      This section discusses the effects of the proposed action on nonendangered marine mammals. Twenty-eight
                 nonendangered species of marine mammals of the Order Cetacea, which includes whales and dolphins, have
                 been identified in the Gulf of Mexico (Table 111-5). By an order of magnitude, the bottlenose dolphin is the
                 most common cetacean in this area. Its distribution and movement suggest that there are several distinctive
                 populations in the Gulf.
                      The major impact-producing factors related to the proposed action that may affect Gulf nonendangered
                 cetaceans include operational discharges, helicopter and service-vessel traffic, platform noise, explosive platform
                 removals, seismic surveys, oil spills and oil-spill response activities. These impact-producing factors are
                 discussed in detail by the National Research Council (1985), Boesch and Rabalais (1987d), Geraci and St.
                 Aubin (1988), USDOI, MMS (1982a and 1987d), and API (1989) and are described below.
                      Produced waters, drilling muds, and drill cutting discharges can potentially impact cetaceans by displacing
                 or reducing their food sources. Offshore operational discharges are not lethal to cetaceans and are diluted and
                 dispersed rapidly to the extent that adverse effects to cetacean food sources do not occur (API, 1989; NRC,
                 1983). The suspended particulate matter in the discharge plume could temporarily inhibit the ability of a
                 cetacean to locate its prey visually or acoustically.
                      Noise from helicopter and service-vessel traffic may elicit a startle reaction from cetaceans or mask their
                 sound reception. This effect is sublethal and at worst of a short-term temporary nature (Gales, 1982).
                 Dolphins are known to actively seek out and accompany service vessels for some distance with no adverse
                 effects. Service vessels could collide with and directly impact cetaceans, but due to dolphin maneuverability
                 and echo-location, encounters of this type are extremely rare (Slijper, 1979; Kraus, personal comm., 1987).










                 IV410

                     Exploration, delineation, and production structures produce sounds at intensities and frequencies that can
                 be heard by cetaceans. The decibel levels of these sounds dissipate to the tolerance of most cetaceans within
                 15 m of the sound source. Odontocetes (toothed cetaceans) communicate and echo-locate at frequencies
                 higher than the dominant sounds generated by offshore drilling and production activities. For example,
                 bottlenose dolphins are sensitive to sound levels in the 143-180 dB range; this high range is unlikely to be
                 generated by offshore drilling operations (Gales, 1982).
                     Explosive platform removals can interfere with communications, disturb behavior, reduce hearing sensitivity
                 or cause hemorrhaging in cetaceans (USDOI, MMS, 1990b). The effects are primarily sublethal and
                 short-term; however, cetaceans proximate to detonationwould likely sustain fatal injuries. Mortalities and fatal
                 injuries have been speculated, but none has been documented. In order to minimize the likelihood of removals
                 occurring when cetaceans may be nearby, MMS has issued guidelines for explosive platlorm removal to
                 offshore operators. These guidelines include daylight detonation only, staggered charges, placement of charges
                 5 in below the seafloor, and pre- and post-detonation surveys of surrounding waters.
                     The sources of acoustical pulse used in seismic surveys are generated by airguns. Should seismic-generated
                 soundwaves exceed the ambient "background"noise they may interfere with cetacean communicationor disturb
                 behavior. Although ambient sound levels in marine environments are highly variable, effects from seismic
                 surveys are limited because seismic sound pressure dissipates to under 200 dB at distances beyond 30 in from
                 the acoustic source (Gales, 1982). Of course, cetaceans in proximity to the source of acoustic transmission
                 could be disturbed by noise. However, the pressure encountered by cetaceans during dives and from natural
                 underwater sounds are often in excess of those produced by seismic activities at the acoustic source. In
                 addition, cetacean populations are highly dispersed, and individual cetaceans easily avoid acoustic interference.
                 The effects on cetaceans from seismic surveys are primarily sublethal and mostly constitute short-term
                 avoidance behavior.
                     Oil spills and oil-spill response activities can adversely affect cetaceans, causing skin and eye irritation,
                 asphyxiation from inhalation of toxic fumes, food reduction or contamination, oil ingestion, and displacement
                 from preferred habitats or migration routes (Goodale et al., 1981; Gruber, 1981; Geraci and St Aubin, 1988).
                 When an oil spill occurs, many factors interact to delimit the severity of effects and the extent of damage to
                 cetaceans. Determining factors include geographic location, oil type, oil dosage, impact area, oceanographic
                 conditions, meteorological conditions, and season (NRC, 1985; USDOI, MMS, 1987b). Cetaceans themselves
                 may actively avoid an oil spill, thereby limiting the effects and lessening the extent of -damage to their
                 populations. Less severe, sublethal effects are defined as those that impair the ability of an organism to
                 function effectively without causing direct mortality (NRC, 1985).
                     Geraci and St. Aubin (1988) noted that determining the risk to cetaceans from an interaction with oil was
                 extremely difficult because of the host of variables involved in the interaction. Generally, species with large
                 ranges and mobility that feed in the water column versus at the surface or on the bottom are less vulnerable
                 to oil. This suggests that Mysticetes (baleen whales) are the most vulnerable, followed by bottlenose dolphins
                 and wide-ranging odontocetes. Although the coastal habitats of the bottlenose dolphin are assumed to be oiled
                 than offshore areas, Geraci and St. Aubin (1982) suggest that dolphins are able to detect and avoid oil. Skin
                 and eye irritation and respiratory disorders caused by contacting oil are sublethal and of a temporary nature
                 (Geraci and St. Aubin, 1988). Death or debilitating illness caused by oil ingestion or by consumption of
                 contaminated food requires large volumes and long-term chronic interactions. Long-term interactions, which
                 could shorten life expectancy or reduce fecundity, have not been studied.

                 Base Case Analysis

                     The major impact-producing factors analyzed below are related to the proposed action and include
                 operational discharges, helicopter and vessel traffic, platform noise, explosive platform removals, seismic
                 surveys, oil spills, and oil-spill response activities.
                     An estimated 2,241,000 bbl of drilling muds, 546,000 bbl of drill cuttings, and 1.3 MM.bbl of produced
                 waters are assumed to be generated offshore as a result of the proposed action. These effluents are routinely
                 discharged into offshore marine waters and are regulated by the U.S. Environmental Protection Agency's
                 NPDES permits. It is estimated that nonendangered cetaceans will have some interaction with these










                                                                                                                             IV-411

                discharges. Direct effects to cetaceans are expected to be sublethal, and effects to cetacean food sources are
                not expected due to the rapid offshore dilution and dispersion of operational discharges. It is estimated that
                operational discharges will rarely contact and affect nonendangered cetaceans.
                     It is assumed that helicopter traffic will occur on a regular basis averaging about 4,000 trips per year. The
                FAA Advisory Circular 91-36C encourages the use of fixed-wing aircraft above an elevation of 152 m and
                helicopters above 300 m. It is estimated that at these elevations no cetaceans will be affected by OCS
                helicopter traffic. It is also estimated that helicopter traffic will rarely disturb and affect nonendangered
                cetaceans because of special prohibitions and adherence to the general, FAA-recommended minimum ceiling
                of 300 m.
                     It is assumed that about 237 OCS-related oil/gas service vessel trips will occur annually as a result of the
                proposed action and that 66 shuttle tanker trips will occur during the 35-year life of the proposed action (Table
                IV-3). Noise from service-vessel traffic may elicit a startle reaction from cetaceans or mask their sound
                reception. This effect is sublethal and, at worst, of a short-term, temporary nature. Cetaceans can avoid
                service vessels, and operators can avoid cetaceans. It is estimated that service vessel traffic will rarely contact
                and affect nonendangered cetaceans.
                     It is assumed that 210 exploration and delineation wells and 110 development wells will be drilled and will
                produce sounds at intensities and frequencies that could be heard by cetaceans. It is estimated that noise from
                drilling activities will last no longer than two months at each location. However, the decibel level of these
                sounds dissipates to the tolerance of most cetaceans within 15 m of the source. Odontocetes communicate at
                higher frequencies than the dominant sounds generated by drilling platforms. Sound levels in this range are
                not estimated to be generated by drilling operations (Gales, 1982). The effects on cetaceans from platform
                noise are expected to be sublethal. It is estimated that drilling noise will rarely disturb and affect
                nonendangered cetaceans.
                     Explosive platform removals can interfere with communication, disturb behavior, reduce hearing sensitivity,
                or cause hemorrhaging in cetaceans. It is estimated that three production platforms will be removed by
                explosives from the Gulf of Mexico as a result of the proposed action. These removals are assumed to occur
                during the last 12 years of the life of the proposed action and no more than one in any given year. It is
                expected that structure removals will cause sublethal effects on cetaceans. No mortalities are expected because
                of the MMS guidelines for explosive removals (USDOI, MMS, 1990a, Appendix B). It is estimated that
                structure removals will rarely disturb and affect nonendangered cetaceans.
                     Seismic surveys use airguns to generate pulses. It is assumed that only these methods will be used in
                seismic surveys as a result of the proposed action (Section IV.A.2.). It is expected that effects on cetaceans
                from seismic surveys are primarily sublethal constituting short-term avoidance behavior.
                     Oil spills and oil-spill response activities can adversely affect cetaceans, causing skin and eye irritation,
                asphyxiation from inhalation of toxic fumes, food reduction or contamination, oil ingestion, and displacement
                from preferred habitats or migration routes. In the event that oiling of cetaceans should occur from sale-
                related oil spills greater than or equal to 1,000 bbl, the effects would primarily be sublethal; few mortalities are
                assumed. The effects of sale-related oil spills less than 1,000 bbl are assumed to be solely sublethal due to the
                inconsiderable area affected and their rapid dispersion. It is assumed that the extent and severity of effects
                from sale-related off spills of any size will be lessened by improved coastal oil spill contingency planning
                (Section IV.C.5.) and by active avoidance of oil spills by cetaceans.
                     Section IV.C.1. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                in the WPA. It is assumed that 8 spills greater than I and less than or equal to 50 bbI will occur during the
                35-year life of the proposed action. It is estimated that the 8 spills will occur offshore and that none will
                contact land. It is assumed that no spill greater than 50 and less than 1,000 bbl will occur during the 35-year
                life of the proposed action. Although an interaction with spills less than 1,000 bbl may occur, only sublethal
                effects are assumed. It is estimated that spills less than 1,000 bbl will infrequently contact and affect
                nonendangered cetaceans.
                     Section IV.C.1. estimates the mean number of spills greater than or equal to 1,000 bbI resulting from the
                proposed action in the WPA. It is assumed that no crude oil spill greater than or equal to 1,000 bbI will occur
                from either a platform or pipeline in the Western Gulf during the 35-year life of the proposed action. It is










                  IV412

                  estimated that an off spill greater than or equal to 1,000 bbI will not contact or affect nonendangered cetaceans
                  in the WPA.

                  Summary

                       Activities resulting from the proposed action have a potential to affect nonendaingered cetaceans
                  detrimentally. These cetaceans could be impacted by operational discharges, helicopter and vessel traffic,
                  platform noise, explosive platform removals, seismic surveys, oil spills, and oil-spill response activities. The
                  effects of the majority of these activities are estimated to be sublethal. Lethal effects are estimated only from
                  oil spills greater than or equal to 1,000 bbl. Sale-related oil spills of any size are estimated to be extraordinary
                  events that will rarely contact nonendangered and nonthreatened cetaceans.

                  Conclusion

                       The impact of the Base Case scenario on nonendangered and nonthreatened cetaceans within the
                  potentially affected area is expected to result in sublethal effects that occur periodically and result in short-term
                  physiological or behavioral changes, as well as some degree of avoidance of the impacted area(s).

                  High Case Analysis

                       The major impact-producing factors analyzed below are related to the proposed action and include
                  operational discharges, helicopter and vessel traffic, platform noise, explosive platform removals, seismic
                  surveys, oil spills and oil-spill response activities.
                       An estimated 4,819,000 bbI of drilling muds, 1.1 MMbbl of drill cuttings, and 3 MMbbI of produced waters
                  are assumed to be discharged annually as a result of the proposed action. These effluents are routinely
                  discharged into offshore marine waters and are regulated by the U.S. Environmental Protection Agency's
                  NPDES permits. It is estimated that nonendangered cetaceans will have some interaction with these
                  discharges. Direct effects to cetaceans are assumed to be sublethal, and effects to cetacean food sources are
                  not assumed due to the rapid offshore dilution and dispersion of operational discharges. It is estimated that
                  operational discharges will rarely contact and affect nonendangered cetaceans.
                       It is assumed that helicopter traffic will occur on a regular basis, averaging about 10,OCO trips each year.
                  The FAA Advisory Circular 91-36C encourages the use of fixed-wing aircraft above an elevation of 152 in and
                  helicopters above 300 in. It is estimated that at these elevations no cetaceans will be affected by OCS
                  helicopter traffic. It is also estimated that helicopter traffic will rarely disturb and affect nonendangered
                  cetaceans because of special prohibitions and adherence to the general, FAA-recommended minimum ceiling
                  of 300 in.
                       It is assumed that about 557 OCS-related oil/gas service vessel trips will occur annually as a result of the
                  proposed action and that 171 total shuttle tanker trips will occur during the 35-year life of the proposed action
                  (Table IV-3). Noise from service-vessel traffic may elicit a startle reaction from cetaceans or mask their sound
                  reception. This effect is sublethal and at worst of a short-term, temporary nature. Cetaceans; can avoid service
                  vessels, and operators can avoid cetaccans. It is estimated that service vessel traffic will rarely contact and
                  affect nonendangered cetaceans.
                       It is assumed that 420 exploration and delineation wells and 270 development wells will be drilled and will
                  produce sounds at intensities and frequencies that could be heard by cetaceans. It is estimated that noise from
                  drilling activities will last no longer than two months at only one location. However, the decibel level of these
                  sounds dissipates to the tolerance of most cetaceans within 15 in of the source. Odontocetes communicate at
                  higher frequencies than the dominant sounds generated by drilling platforms. Sound levels in this range are
                  not likely to be generated by drilling operations (Gales, 1982). The effects on cetaccans from platform noise
                  are expected to be sublethal. It is estimated that drilling noise will rarely disturb and affect nonendangered
                  cetaceans.
                       Explosive platform removals can interfere with communication, disturb behavior, reduce hearing sensitivity
                  or cause hemorrhaging in cetaceans. It is estimated that six structures will be removed by explosives from the










                                                                                                                             IV413

                Gulf of Mexico as a result of the proposed action. These removals are assumed to occur during the last 12
                years of the life of the proposed action and no more than 2 in any single year (rabic IV-3). It is expected that
                structure removals will cause sublethal effects on cetaccans. No mortalities are expected because of the MMS
                guidelines for explosive removals (USDOI, MMS, 1990a, Appendix B). It is estimated that structure removals
                will rarely disturb and affect nonendangered cetaccans.
                     Seismic surveys use airguns to generate pulses. It is assumed that only these methods will be used in
                seismic surveys as a result of the proposed action. It is expected that effects on cetaceans from seismic surveys
                are primarily sublethal, constituting short-term avoidance behavior.
                     Oil spills and oil-spill response activities can adversely affect cetaceans, causing skin and eye irritation,
                asphyxiation from inhalation of toxic fumes, food reduction or contamination, oil ingestion, and displacement
                from preferred habitats or migration routes. In the event that oiling of cetaceans should occur from sale-
                related oil spills greater than or equal to 1,000 bbl, the effects would primarily be sublethal; few mortalities are
                assumed. The effects of sale-related oil spills less than 1,000 bbl are assumed to be solely sublethal due to the
                inconsiderable area affected and their rapid dispersion. It is assumed that the extent and severity of effects
                from sale-related off spills of any size will be lessened by improved coastal off-spill contingency planning
                (Section IV.C.5.) and by active avoidance of oil spills by cetaceans.
                     Section W.C. 1. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                in the WPA. It is assumed that 20 spills greater than 1 and less than or equal to 50 bbl will occur during the
                35-year life of the proposed action. It is estimated that the 20 spills will occur offshore and that none will
                contact land (Section MA-2.). It is assumed that 1 spill greater than 50 and less than 1,000 bbI will occur
                during the 35-year life of the proposed action, and it is estimated that the spill will occur offshore and that
                none of the oil will contact land. Although an interaction with spills less than 1,000 bbl may occur, only
                sublethal effects are assumed. It is estimated that spills less than 1,000 bbl will infrequently contact and affect
                nonendangered cetaceans. The impact level is assumed to be low.
                     Section MCA. estimates the mean number of spills greater than or equal to 1,000 bbl resulting from the
                proposed action in the WPA. It is assumed that one crude oil spill greater than or equal to 1,000 bbl will occur
                from either a platform or pipeline in the Western Gulf during the 35-year life of the proposed action. Table
                IV-22 identifies the estimated risk of one or more oil spills greater than or equal to 1,000 bbl occurring and
                contacting areas within 10 days where cetaceans have been surveyed. There is a 5 percent probability that an
                oil spill greater than or equal to 1,000 bbl will occur and contact within 10 days cetacean habitats at or beyond
                the shelf break of the WPA. There is a I percent probability that an oil spill greater than or equal to 1,000
                bbl will occur and contact within 10 days coastal areas of Texas (Table IV-22). Although an interaction with
                spills greater than or equal to 1,000 bbl may occur, infrequent mortalities are assumed with primarily sublethal
                effects. It is estimated that an oil spill greater than or equal to 1,000 bbl will rarely contact and affect
                nonendangered cetaceans in the WPA_
                     Activities resulting from the proposed action have a potential to affect nonendangered cetaceans,
                detrimentally. These cetaceans could be impacted by operational discharges, helicopter and vessel traffic,
                platform noise, explosive platform removals, seismic surveys, oil spills, and oil-spill response activities. The
                effects of the majority of these activities are estimated to be sublethal. Lethal effects are estimated only from
                off spills greater than or equal to 1,000 bbl. Sale-related oil spills of any size are estimated to be extraordinary
                events that will rarely contact nonendangered and nonthreatened cetaceans.

                Conclusion

                     The impact of the High Case scenario on nonendangered and nonthreatened cetaceans within the
                potentially affected area is assumed to result in sublethal effects that are chronic and could result in persistent
                physiological or behavior changes, as well as some degree of avoidance of the impacted area(s).










                 IV414

                 (b) Endangered and Threatened Species

                      This section discusses the effects of the proposed action on blue, right, sei, humpback, fin, and sperm
                 whales. For a detailed discussion of these species, see Section III.B.3.a.(2). The sperm whale is the species
                 most commonly seen in the Gulf of Mexico.
                      The major impact-producing factors related to the proposed action are discussed in detail by the National
                 Research Council (1985), Boesch and Rabalais (1987), Geraci and St. Aubin (1988), USDOI, MMS (1982a and
                 1987d), and API (1989), and are described in the preceding section (Section IV.D.2.a.(5)(a'
                                                                                                                  ,i, nonendangered
                 and nonthreatened species).

                 Base Case Analysis

                      The major impact-producing factors analyzed below are related to the proposed action and include
                 operational discharges, helicopter and vessel traffic, platform noise, explosive platform removals, seismic
                 surveys, oil spills, and oil-spill response activities.
                      An estimated 2,241,000 bbl of drilling muds, 546,000 bbl of drill cuttings, and 1.1 MMbbI of produced
                 waters are assumed to be generated offshore as a result of the proposed action (Table IV-3). These effluents
                 are routinely discharged into offshore marine waters and are regulated by the U.S. Environmental Protection
                 Agency's NPDES permits. It is estimated that endangered cetaceans will have some interaction with these
                 discharges. Direct effects to cetaceans are expected to be sublethal, and effects to cetacean food sources are
                 not expected due to the rapid offshore dilution and dispersion of operational discharges. It is estimated that
                 operational discharges will rarely contact and affect endangered cetaceans.
                      It is assumed that helicopter traffic will occur on a regular basis, averaging about 4,000 trips per year. The
                 FAA Advisory Circular 91-36C encourages the use of Exed-wing aircraft above an elevation of 152 m and
                 helicopters above 300 m. It is estimated that at these elevations no cetaceans will be affected by OCS
                 helicopter traffic. It is also estimated that helicopter traffic will rarely disturb and affect endangered cetaceans
                 because of special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 m.
                      It is assumed that about 237 OCS-related oil/gas service-vessel trips will occur annually as a result of the
                 proposed action and that 66 shuttle tanker trips will occur during the 35-year life of the proposed action (Table
                 IV-3). The shuttle tanker trips are expected to occur in coastal Subarea W-3, inshore of the areas where sperm
                 and fin whales have been sighted. Noise from service vessel traffic may elicit a startle reaction from cetaceans
                 or mask their sound reception. This effect is sublethal and, at worst, of a short-term, temporary nature.
                 Cetaceans can avoid service vessels, and operators can avoid cetaceans. It is estimated that service-vessel
                 traffic will rarely contact and affect endangered cetaceans.
                      It is assumed that 210 exploration and delineation wells and 110 development wells will be drilled and win
                 produce sounds at intensities and frequencies that could be heard by cetaceans. It is estimated that noise from
                 drilling'activities will last no longer than two months at each location. However, the decibel level of these
                 sounds dissipates to the tolerance of most cetaceans within 15 m of the source. Odontocetes communicate at
                 higher frequencies than the dominant sounds generated by drilling platforms. Sound levels in this range are
                 not likely to be generated by drilling operations (Gales, 1982). The effects on cetaceans from platform noise
                 are expected to be sublethal. It is estimated that drilling noise will rarely disturb and affect endangered
                 cetaceans.
                      Explosive platform removals can temporarily interfere with communication, disturb behavior, permanently
                 reduce hearing sensitivity, or cause hemorrhaging in cetaceans. It is estimated that three production platforms
                 will be removed using explosives from the Gulf of Mexico as a result of the proposed action. These removals
                 are assumed to occur during the last 12 years of the life of the proposed action, with no more than 1 removal
                 in any given year (Table IV-3). It is expected that structure removals will cause sublethal effects on cetaceans.
                 No mortalities are expected because of the MMS guidelines for explosive removals (USDOI, MMS, 1990a,
                 Appendix B). It is estimated that structure removals will rarely disturb and affect endangered cetaceans.










                                                                                                                            IV-415

                    Seismic surveys use airguns to generate pulses. It is assumed that only these methods will be used in
               seismic surveys as a result of the proposed action (Section IV.A.2.). It is e   xpected that effects on cetaceans
               from seismic surveys are primarily sublethal, constituting short-term avoidance behavior.
                    Oil spills and ofl-spill response activities can adversely affect cetaceans, causing skin and eye irritation,
               asphyxiation from inhalation of toxic fumes, food reduction or contamination, oil ingestion, and displacement
               from preferred habitats or migration routes. In the event that oiling of cetaceans should occur from sale-
               related oil spills greater than or equal to 1,000 bbl, the effects would primarily be sublethal; few mortalities are
               assumed. The effects of sale-related oil spills less than 1,000 bbl are assumed to be solely sublethal due to the
               inconsiderable area affected and their rapid dispersion. It is assumed that the "tent and severity of effects
               from sale-related oil spills of any size will be lessened by improved coastal oil-spill contingency planning
               (Section IV.C.5.) and by active avoidance of oil spills by cetaceans.
                    Section IV.C. 1. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
               in the WPA. It is assumed that eight spills greater than 1 and less than or equal to 50 bbl will occur during
               the 35-year life of the proposed action. It is estimated that the eight spills will occur offshore and that none
               will contact land. It is assumed that no spill greater than 50 and less than 1,000 bbl win occur during the 35-
               year life of the proposed action. Although an interaction with spills may occur, only sublethal effects are
               assumed. It is estimated that small spills will infrequently contact and affect endangered cetaceans.
                    Section IV.C.1. estimates the mean number of spills greater than or equal to 1,000 bbl resulting from the
               proposed action in the WPA. It is assumed that no crude oil spill greater than or equal to 1,000 bbl will occur
               from either a platform or pipeline in the Western Gulf during the 35-year fife of the proposed action. It is
               estimated that a off spill greater than or equal to 1,000 bbl will not contact or affect endangered cetaceans in
               the WPA_


               Summary

                    Activities resulting from the proposed action have a potential to affect endangered cetaceans detrimentally.
               These cetaceans could be impacted by operational discharges, helicopter and vessel traffic, platform noise,
               explosive platform removals, seismic surveys, oil spills, and oil-spill response activities. The effects of the
               majority of these activities are estimated to be sublethal. Lethal effects are estimated only from oil spills
               greater than or equal to 1,000 bbl. Sale-related oil spills of any size are estimated to be extraordinary events
               that will rarely contact endangered and threatened cetaceans.

               Conclusion

                    The impact of the Base Case scenario on endangered and threatened cetaceans within the potentially
               affected area is assumed to result in sublethal effects that occur periodically and result in short-term
               physiological or behavioral changes, as well as some degree of avoidance of the impacted area(s).

               High Case Analysis

                    The major impact-producing factors analyzed below are related to the proposed action and include
               operational discharges, helicopter and vessel traffic, platform noise, explosive platform removals, seismic
               surveys, oil spills, and oil-spill response activities.
                    An estimated 4,819,000 bbl of drilling muds, 1. 1 MMbbl of drill cuttings, and 3 MMbbI of produced waters
               are assumed to be generated offshore as a result of the proposed action. These effluents are routinely
               discharged into offshore marine waters and are regulated by the U.S. Environmental Protection Agency's
               NPDES permits. It is estimated that endangered cetaceans will have some interaction with these discharges.
               Direct effects to cetaceans are expected to be sublethal, and effects to cetacean food sources are not expected
               due to the rapid offshore dilution and dispersion of operational discharges. It is estimated that operational
               discharges will rarely contact and affect endangered cetaceans.
                    It is assumed that helicopter traffic will occur on a regular basis, averaging about 10,000 trips per year.
               The FAA Advisory Circular 91-36C encourages the use of fixed-wing aircraft above an elevation of 152 m and










                    IV416

                    helicopters above 300 in. It is estimated that at these elevations no cetaceans will be affected by OCS )
                    helicopter traffic. It is also estimated that helicopter traffic will rarely disturb and affect endangered cetaceans
                    because of special prohibitions and adherence to the general, FAA-recommended mininium ceiling of 300 in.
                         It is assumed that about 557 OCS-related oil/gas service-vessel trips will occur during the peak year of the
                    proposed action, and that 171 total shuttle tanker trips will occur during the 35-year life of the proposed action
                    (Table IV-3). Noise from service vessel traffic may elicit a startle reaction from cetaceans or mask their sound
                    reception. This effect is sublethal and, at worst, of a short-term, temporary nature. Cetaceans can avoid
                    service vessels, and operators can avoid cetaceans. It is estimated that service-vessel traffic will rarely contact
                    and affect endangered cetaceans.
                         It is assumed that 420 exploration and delineation wells and 270 development wells WE] be drilled and will
                    produce sounds at intensities and frequencies that could be heard by cetaceans. It is estimated that noise from
                    drilling activities will last no longer than two months at only one location. However, the decibel level of these
                    sounds dissipates to the tolerance of most cetaceans within 15 in of the source. Odontocetes communicate at
                    higher frequencies than the dominant sounds generated by drilling platforms. Sound levels in this range are
                    not likely to be generated by drilling operations (Gales, 1982). The effects on cetaceans from platform noise.
                    are expected to be sublethal. It is estimated that drilling noise will rarely disturb and affect endangered
                    cetaceans.
                         Explosive platform removals can interfere with communication, disturb behavior, reduce hearing sensitivity,
                    or cause hemorrhaging in cetaceans. It is estimated that six production platforms will be removed by explosives
                    from the Gulf of Mexico as a result of the proposed action. These removals are assumed to occur during the
                    last 12 years of the life of the proposed action, with no more than 2 in any given year (Table IV-3). It is
                    expected that structure removals will cause sublethal effects on cetaceans. No mortalities are expected because
                    of the MMS guidelines for explosive removals (USDOI, MMS, 1990a, Appendix B). It is estimated that
                    structure removals will rarely disturb and affect endangered cetaceans.
                         Seismic surveys use airguns to generate pulses. It is assumed that only these methods will be used kk
                    seismic surveys as a result of the proposed action (Section IV.A.2.). It is expected that effects on cetaceans
                    from seismic surveys are primarily sublethal, constituting short-term avoidance behavior.
                         Oil spills and oil-spill response activities can adversely affect cetaceans, causing skin and eye irritation,
                    asphyxiation from inhalation of toxic fumes, food reduction or contamination, oil ingestion, and displacement
                    from preferred habitats or migration routes. In the event that oiling of cetaceans should occur from sale..
                    related oil spills greater than or equal to 1,000 bbl, the effects would primarily be sublethal; few mortalities are
                    assumed. The effects of sale-related oil spills less than 1,000 bbI are assumed to be solely sublethal due to the
                    inconsiderable area affected and their rapid dispersion. It is assumed that the extent and severity of effect,;
                    from sale-related oil spills of any size will be lessened by improved coastal oil-spill contingency planning,
                    (Section IV.C.5.) and by active avoidance of oil spills by cetaceans.
                         Section IV.C. I estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                    in the WPA_ It is assumed that 20 spills greater than 1 and less than or equal to 50 bbI will occur during the:
                    35-year life of the proposed action. It is estimated that the 20 spills will occur offshore and that none will.
                    contact land. It is assumed that 1 spill greater than 50 and less than 1,000 bbl will occur during the 35-year
                    life of the proposed action, and it is estimated that the spill will occur offshore and that no oil will contact land.
                    Although an interaction with small spills may occur, only sublethal effects are assumed. It is estimated that
                    small spills will infrequently contact and affect endangered cetaceans.
                         Section IV.C.1. estimates the mean number of spills greater than or equal to 1,000 bbl resulting from the
                    proposed action in the WPA. It is assumed that one crude oil spill greater than or equal to 1,000 bbI will occur
                    from either a platform or pipeline in the Western Gulf during the 35-year life of the proposed action. Table
                    IV-22 identifies the estimated risk of one or more oil spills greater than or equal to 1,000 bbI occurring anti
                    contacting areas within 10 days where cetaceans have been surveyed. There is a 5 percent probability that an
                    oil spill greater than or equal to 1,000 bb] will occur and contact within 10 days cetacean habitats at or beyoncl
                    the shelf break of the WPA. There is a I percent probability that an oil spill greater than or equal to 1,000
                    bbi will occur and contact within 10 days coastal areas of Texas (Table IV-22). Although an interaction with
                    spills greater than or equal to 1000 bbl may occur, infrequent mortalities are assumed with primarily sublethal.










                                                                                                                          IV-417

                effects. It is expected that an oil spill greater than or equal to 1,000 bbl will rarely contact and affect
                endangered cetaceans in the WPA.
                    Activities resulting from the proposed action have a potential to affect endangered cetaceans detrimentally.
                These cetaceans could be impacted by operational discharges, helicopter and vessel traffic, platform noise,
                explosive platform removals, seismic surveys, oil spins, and oil-spill response activities. The effects of the
                majority of these activities are estimated to be sublethal. Lethal effects are estimated only from oil spins
                greater than or equal to 1,000 bbl. Sale-related oil spins of any size are estimated to be extraordinary events
                that will rarely contact endangered and threatened cetaceans.

                Conclusion

                    The impact of the High Case scenario on endangered and threatened cetaceans within the potentially
                affected area is assumed to result in sublethal effects that are chronic and could result in persistent
                physiological or behavioral changes, as well as some degree of avoidance of or displacement from the impacted
                area(s).

                (6) Impacts on Marine Turtles

                    This section discusses the effect of the proposed action on the loggerhead, Kemp's ridley, hawksbill, green,
                and leatherback marine turtles of the Gulf of Mexico. The major impact-producing factors related to the
                proposed action are discussed in detail in Decline of the Sea nilles: Causes and Prevention (NRC, 1990) and
                are described below.
                    The major impact-producing factors related to the proposed action that may affect Gulf marine turtles
                include anchoring, structure installation, pipeline placement, dredging, operational discharges, vessel traffic,
                explosive platform removals, OCS-related trash and debris, oil-spill response activities, and oil spins.
                    Anchoring, structure installation, pipeline placement, dredging, and operational discharges may adversely
                affect marine turtle habitat through destruction of seagrass beds and live-bottom communities. Effects to these
                habitats from the above mentioned impact-producing factors are described and analyzed in detail in Sections
                IV.D.La.(1) and (2).
                    Noise from service-vessel traffic may elicit a startle reaction from marine turtles. This effect is sublethal
                and, at worst, of a short-term, temporary nature (NRC, 1990). Service vessels could collide with and directly
                impact marine turtles. Vessel-related injuries were noted in 9 percent of the marine turtles stranded in the
                Gulf of Mexico during 1988 (USDOC, NMFS, 1989b). This observation was not able to distinguish between
                live and dead turtles struck by boats. Marine turtles spend no more than 4 percent of their time at the surface,
                and less time than that during the winter (Byles, 1989; Lohoefener et al., 1990).
                    Explosive platform removals can cause capillary damage, disorientation, and loss of motor control in marine
                turtles (Duronslet et al., 1986). The effects are primarily sublethal and short-term; however, marine turtles
                proximate to detonationwould likely sustain fatal injuries. Mortalities and fatal injuries have been speculated,
                but none has been documented. Although marine turtles occur near offshore off and gas structures, aerial
                surveys in the Western Gulf have shown no statistical correlation between marine turtles and offshore structures
                (Lohoefener, personal comm., 1989). To minimize the likelihood of removals occurring when marine turtles
                may be nearby, MMS has issued guidelines for explosive platform removal to offshore operators. These
                guidelines include daylight detonation only; use of high-velocity explosives each less than 23 kg; staggered
                charges; placement of charges 5 in below the seafloor, and pre- and post-detonation surveys of surrounding
                waters.
                    Marine turtles can become entangled in monofilament fishing line, netting, 6-pack yokes, etc., which may
                result in injury or mortality. Marine turtles are known to be attracted to floating plastic debris because of its
                resemblance to their preferred food, the jellyfish. Ingestion of plastic and styrofoam materials could result in
                drowning, lacerations, digestive disorders or blockage, and reduced mobility resulting in starvation (Balazs,
                1985; Carr, 1987; USDOC, NOAA, 1988d; Heneman and the Center for Environmental Education, 1988;
                USDOI, MMS, 1989a). The MMS prohibits the disposal of equipment, containers, and other materials into










                 IV-418

                 offshore waters by lessees (30 CFR 250.40). In addition, MARPOL, Annex V, Public Law 100-220 (101 Statute
                 1458), which prohibits the disposal of any plastics at sea or in coastal waters, went into effect January 1, 1989.
                     Oil-spffl response activities, such as vehicular and vessel traffic in shallow areas of seagrass beds and live-
                 bottom communities, can adversely affect sea turtle habitat and cause displacement from these preferred areas.
                 These habitats receive particular consideration during oil-spill cleanup. Because of the special designation and
                 general status of those areas, oil-spill contingency plans include special notices to minimize adverse effects from
                 vehicular traffic during cleanup activities and to maximize the protection efforts to prevent contact of these
                 areas with spilled oil (Section IV.C.5.).
                     Oil spills can adversely affect marine turtles by toxic external contact, toxic ingestion or blockage of the
                 digestive tract, asphyxiation, entrapment in tar or oil sticks, habitat destruction, and di;placement from
                 preferred habitats (Fritts and McGehee, 1981; Vargo et al., 1986; Boesch and Rabalais, 1987; Lutz, 1989).
                 Pelagic life stages are particularly vulnerable to contacting or ingesting oil because the currents that concentrate
                 oil spills also form the debris mats that these life stages inhabit (Vargo et al., 1986). Fritts and McGehee
                 (1982) noted that sea turtle eggs were rendered infertile on contact with oil.
                     When an oil spill occurs, many factors interact to delimit the severity of effects and the extent of damage
                 to cetaceans. Determining factors include geographic location, oil type, oil dosage, impact area, oceanographic
                 conditions, meteorological conditions, and season (NRC, 1985; USDOI, MMS, 1987b). Less severe, sublethal
                 effects are defined as those that impair the ability of an organism to function effectively without causing direct
                 mortality (NRC, 1985).

                 Base Case Analysis

                     The major impact-producing factors related to the proposed action that may affect Gulf marine turtles
                 include anchoring, structure installation, pipeline placement, dredging, operational discharges, OCS-related
                 trash and debris, vessel traffic, explosive platform removals, oil-spill response activities, and oil spills.
                     The impact from anchoring, structure installation, pipeline placement, dredging, and operational discharges
                 on seagrass bed and five-bottom sea turtle habitat is analyzed in detail in Sections IV.D.l.a.(I) and (2).
                     To summarize the effects on wetlands and estuaries, it is expected that a dieback of up to 10-15 ha of
                 wetlands will occur for less than one growing season from contact with spilled oft. Up to 5.5 ha of wetlands
                 and estuaries could be eroded along navigation channels as a result of vessel traffic within the channels. Effects
                 to wetlands and estuaries will occur along the north Texas coast. To summarize the effects on seafloor habitats
                 little or no damage is expected to the physical integrity, species, diversity, or biological productivity of
                 topographic features or live bottoms. Small areas of 5-10 m2 would be affected for less than two years,
                 probably on the order of four weeks. Offshore operational discharges are not lethal to marine turtles and are
                 diluted and dispersed rapidly within 1 kin of the discharge point to the extent that adverseeffects to marine
                 turtle food sources do not occur (API, 1989; NRC, 1983). It is expected that effects on marine turtles from
                 anchoring, structure installation, pipeline emplacement, and dredging will be indistinguishable from the long-
                 term (25-50 years I  natural variability within populations of marine turtles. It is expected that marine turtles
                 will avoid 5-10 in of live-bottom areas for up to a month and that this avoidance of impoverished foraging
                 areas will have no effect on marine turtles. The suspended particulate matter in operational discharges
                 offshore is expected to cause sublethal effects by inhibition of the ability of marine turtles to locate their prey
                 visually within 1 kin of the discharge point for the short time period (less than one hour) spent traversing the
                 plume.
                     Sublethal effects on marine turtles or their habitats are expected from these impact-producing factors.
                 Based on the aforementioned analyses, the estimate is that anchoring, structure installation, pipeline placement,
                 dredging, and operational discharges will rarely contact and affect marine turtles or their habitats.
                     Marine turtles can become entangled in or ingest trash and debris. It is assumed that some OCS-related
                 trash and debris will be accidentally lost into the Gulf and available for interaction with marine turtles.
                 Although mortalities could occur, primarily sublethal effects are expected. It is estimated that OCS off- and
                 gas-related trash and debris will rarely interact with and affect marine turtles.
                     Explosive platform removals can cause capillary damage, disorientation, loss of motor control, and fatal
                 injuries in marine turtles. It is estimated that three production platforms will be removed by explosives from










                                                                                                                              IV-419

                the Gulf of Mexico as a result of the proposed action. It is assumed that these removals occur during the last
                12 years of the life of the proposed action with no more than 1 in any single year and that some of the
                platform removals will occur beyond the continental shelf. As benthic feeders, Gulf of Mexico hard shell
                marine turtles do not use habitats beyond the shelf break. Although the pelagic life stages of all marine turtles
                use these habitats, there is no correlation between marine turtles and the presence of offshore structures
                beyond the shelf break. It is expected that structure removals will cause sublethal effects on marine turtles.
                No mortalities are expected because of the MMS guidelines for explosive removals (USDOI, MMS, 1990a,
                Appendix B) and because the removals occur away from preferred offshore habitats. It is estimated that
                structure removals will rarely disturb and affect marine turtles.
                    It is assumed that about 237 OCS-related oil and gas service-vessel trips will occur annually as a result of
                the proposed action and that 66 shuttle tanker trips will occur during the 35-year life of the proposed action
                (Table IV-3). Noise from service-vessel traffic may elicit a startle reaction from marine turtles. This effect is
                sublethal and, at worst, of a short-term, temporary nature. Collision between service vessels and surfaced
                marine turtles would likely cause fatal injuries. It is assumed that service-vessel traffic and marine turtles will
                rarely be in close proximity. Although a low percentage of stranded marine turtles have shown indications
                of vessel collision, it cannot be determined what types of vessel were involved and whether these injuries
                occurred before or after death. Marine turtles are known to spend 4 percent or less of their time at the
                surface and to sound upon vessel approach. In addition, marine vessel operators can avoid marine turtles.
                It is estimated that service-vessel traffic will rarely contact and affect marine turtles.
                    Oil spills and oil-spill response activities can adversely affect marine turtles by toxic external contact, toxic
                ingestion or blockage of the digestive tract, asphyxiation, entrapment in tar or oil slicks, habitat destruction,
                and displacement from preferred habitats. Oil-spill response activities such as vehicular and vessel traffic are
                assumed to contact marine turtle habitat, such as shallow areas of seagrass beds and live-bottom communities,
                in the event of contact with a oil spill greater than or equal to 1,000 bbl. Sublethal effects are assumed due
                to the particular consideration these areas receive during oil-spill cleanup to minimize adverse effects from
                traffic during cleanup activities and to maximize protection efforts to prevent contact of these areas with spilled
                oil. It is estimated that oil-spill response activities will rarely contact and affect marine turtle habitat
                    In the event that oiling of marine turtles should occur from sale-related oil spills greater than or equal to
                1,000 bbl, the effects would primarily be sublethal; few mortalities are assumed. The effects of sale-related oil
                spills less than 1,000 bbI are assumed to be solely sublethal due to the inconsiderable area affected and their
                rapid dispersion. It is assumed that the extent and severity of effects from sale-related oil spills of any size will
                be lessened by improved coastal oil-spill contingency planning (Section IV.C.5.) and by active avoidance of oil
                spills by marine turtles.
                    Section IV.C.1. estimates the mean number of spills less than 1,000 bbI occurring from the proposed action
                in the WPA_ It is assumed that eight spills greater than 1 and less than or equal to 50 bbI will occur during
                the 35-year life of the proposed action (Table IV-3). It is estimated that the 8 spills Will occur offshore and
                that none will contact land. It is assumed that no spill greater than 50 and less than 1,000 bbI will occur during
                the 35-year life of the proposed action. Although an interaction with spills less than 1,000 bbI may occur, only
                sublethal effects are assumed. It is estimated that small spills will infrequently contact and affect marine turtles.
                    Section IV.C.I. estimates the mean number of spills greater than or equal to 1,000 bbI resulting from the
                proposed action in the WPA. It is assumed that no crude oil spill greater than or equal to 1,000 bbI will occur
                from either a platform or pipeline in the Western Gulf during the 35-year life of the proposed action. It is
                estimated that an oil spill greater than or equal to 1,000 bbl will not contact and affect marine turtles in the
                WPA.


                Summmy

                    Activities resulting from the proposed action have a potential to affect marine turtles detrimentally. Marine
                turtles could be impacted by anchoring, structure installation, pipeline placement, dredging, operational
                discharges, OCS-related trash and debris, vessel traffic, explosive platform removals, oil-spill response activities,
                and oil spills. The effects of the majority of these activities are estimated to be sublethal. Lethal effects are










                  IV420

                  estimated only from off spills greater than or equal to 1,000 bbl. Sale-related oil spills of any size are estimated
                  to be extraordinary events that will rarely contact marine turtles.

                  Conclusion


                       The impact of the Base Case scenario on marine turtles within the potentially affected Effea is assumed to
                  result in sublethal effects that are chronic and could result in persistent physiological or behavioral changes.

                  High Case Ana4uis

                       The major impact-producing factors related to the proposed action that may affect Gulf marine turtles
                  include anchoring, structure installation, pipeline placement, dredging, operational discharges, OCS-related trash
                  and debris, vessel traffic, explosive platform removals, oil-spill response activities, and off spills.
                       The impact from anchoring, structure installation, pipeline placement, dredging, and operational discharges
                  on seagrass bed and live-bottom sea turtle habitat is analyzed in detail in Sections IV.D.Lai.(1) and (2).
                       To summarize the effects on wetlands and estuaries, it is expected that a dieback of up to 10-15 ha of
                  wetlands will occur for less than one growing season from contact with spilled oil. Up to 5.5 ha of wetlands
                  and estuaries could be eroded along navigation channels as a result of OCS-vessel traffic wi4hin the channels.
                  Effects to wetlands and estuaries will occur in Louisiana and along the north Texas coast. To summarize the
                  effects on seafloor habitats, little or no damage is expected to the physical integrity, species, diversity, or
                  biological productivity of topographic features or live bottoms. Small areas of 5_10 M2 would be affected for
                  less than two years, probably on the order of four weeks. Offshore operational discharges are not lethal to
                  marine turtles and are diluted and dispersed rapidly within 1 km of the discharge point to the extent that
                  adverse effects to marine turtle food sources do not occur (API, 1989; NRC, 1983). It is expected that effects
                  on marine turtles from anchoring, structure installation, pipeline emplacement, and dredging will be
                  indistinguishable from the long-term (25-50 years) natural variability within populations of marine turtles. It
                  is expected that marine turtles will avoid 5-10 M2 of live-bottom areas for up to a month and that this
                  avoidance of impoverished foraging areas will have no effect on marine turtles. The suspended particulate
                  matter in operational discharges offshore are expected to cause sublethal effects by inhibition of the ability of
                  marine turtles to locate its prey visually within 1 km of the discharge point for the short time period (less than
                  one hour) spent traversing the plume.
                       Sublethal effects on marine turtles or their habitats are expected from these impact-'producing factors.
                  Based on the aforementioned analyses, the estimate is that anchoring, structure installation, pipeline placement,
                  dredging, and operational discharges will rarely contact and affect marine turtles or their habitats.
                       Marine turtles can become entangled in or ingest trash and debris. It is assumed that -some OCS-related
                  trash and debris will be accidentally lost into the Gulf and available for interaction with marine turtles.
                  Although mortalities could occur, primarily sublethal effects are expected. It is estimated that OCS oil- and
                  gas-related trash and debris will rarely interact with and affect marine turtles.
                       Explosive platform removals can cause capillary damage, disorientation, loss of motor control, and fatal
                  injuries in marine turtles. It is estimated that six production platforms will be removed by explosives from the
                  Gulf of Mexico as a result of the proposed action. It is assumed that these removals occur during the last 12
                  years of the life of the proposed action with no more than 2 in any single year and that some of the platform
                  removals will occur in habitats beyond the continental shelf. As benthic feeders, Gulf of 'Mexico hard-shell
                  marine turtles do not use habitats beyond the shelf break. Although the pelagic life stages of all marine turtles
                  do use these habitats, there is no correlation between marine turtles and the presence of offshore structures
                  beyond the shelf break. It is expected that structure removals will cause sublethal effects on marine turtles.
                  No mortalities are expected because of the MMS guidelines for explosive removals (USDOI, MMS, 1990a,
                  Appendix B) and because the removals occur away from preferred offshore habitat It is estimated that
                  structure removals will rarely disturb and affect marine turtles.
                       It is assumed that about 557 OCS-related oil and gas service-vessel trips will occur annually as a result of
                  the proposed action and that 185 shuttle tanker trips will occur during the 35-year life of the proposed action
                  (Table IV-3). Noise from service-vessel traffic may elicit a startle reaction from marine turtles. This effect is










                                                                                                                                IV-421

                sublethal and, at worst, of a short-term, temporary nature. Collision between service vessels and surfaced
                marine turtles would likely cause fatal injuries. It is assumed that service-vessel traffic and marine turtles win
                rarely be in close proximity. Although a low percentage of stranded marine turtles have shown indications
                of vessel collision, it cannot be determined what types of vessel were involved and whether these injuries
                occurred before or after death. Marine turtles are known to spend 4 percent or less of their time at the
                surface and to sound upon vessel approach. In addition, marine vessel operators can avoid marine turtles.
                It is estimated that service-vessel traffic will rarely contact and affect marine turtles.
                     Oil spills and oil-spill response activities can adversely affect marine turtles by toxic external contact, toxic
                ingestion or blockage of the digestive tract, asphyxiation, entrapment in tar or oil slicks, habitat destruction,
                and displacement from preferred habitats. Ofl-spill response activities such as vehicular and vessel traffic are
                assumed to contact marine turtle habitat, such as shallow areas of seagrass beds and live-bottom communities,
                in the event of contact with an oil spill greater than or equal to 1,000 bbl. Sublethal effects are assumed due
                to the particular consideration these areas receive during oil-spill cleanup to minimize adverse effects from
                traffic during cleanup activities and to maximize protection efforts to prevent contact of these areas with spilled
                oil. It is estimated that oil-spill response activities will rarely contact and affect marine turtle habitat.
                     In the event that oiling of marine turtles should occur from sale-related oil spills greater than or equal to
                1,000 bbl, the effects would primarily be sublethal; few mortalities are assumed. The effects of sale-related oil
                spills less than 1,000 bbI are assumed to be solely sublethal due to the inconsiderable area affected and their
                rapid dispersion. It is assumed that the extent and severity of effects from sale-related oil spills of any size will
                be lessened by improved coastal oil-spill contingency planning (Section IV.C.5.) and by active avoidance of oil
                spills by marine turtles.
                     Section IV.C.1. estimates the mean number of small spills less than 1,000 bbI occurring from the proposed
                action in the WPA. It is assumed that 20 spills greater than 1 and less than or equal to 50 bbl will occur during
                the 35-year life of the proposed action. It is estimated that the 20 spills will occur offshore and that none will
                contact land. It is assumed that one spill greater than 50 and less than 1,000 bbl will occur during the 35-year
                life of the proposed action, and it is estimated that the spill will occur offshore and that no oil will contact land.
                Although an interaction with small spills may occur, only sublethal effects are assumed. It is estimated that
                small spills will infrequently contact and affect marine turtles.
                     Section IV.C.1. estimates the mean number of spills greater than or equal to 1,000 bbI resulting from the
                proposed action in the WPA_ It is assumed that 1 crude oil spill will occur from either a platform or pipeline
                in the Western Gulf during the 35-year life of the proposed action. Table IV-22 identifies the estimated risk
                of one or more oil spills occurring and contacting marine turtle habitat within 10 days. The highest estimated
                probability of one or more oil spills greater than or equal to 1,000 bbI occurring and contacting marine turtle
                habitat within 10 days in the Western Gulf is 1 percent (Texas coastal areas). There is a 5 percent probability
                that a off spill will occur and contact within 10 days pelagic turtle habitat beyond the shelf break of the WPA_
                Although an interaction with spills greater than or equal to 1,000 bbl may occur, infrequent mortalities are
                assumed with primarily sublethal effects. It is expected that an oil spill greater than or equal to 1,000 bbI will
                rarely contact and affect marine turtles in the WPA.
                     Activities resulting from the proposed action have a potential to affect marine turtles detrimentally. Marine
                turtles could be impacted by anchoring, structure installation, pipeline placement, dredging, operational
                discharges, OCS-related trash and debris, vessel traffic, explosive platform removals, oil-spill response activities,
                and oil spills. The effects of the majority of these activities are estimated to be sublethal. Lethal effects are
                estimated only from oil spills greater than or equal to 1,000 bbl. Sale-related oil spills of any size are estimated
                to be extraordinary events that will rarely contact marine turtles.

                Conclusion


                     The impact of the High Case scenario on marine turtles within the potentially affected area is assumed to
                result in sublethal effects that are chronic and could result in persistent physiological or behavioral changes.










                 IV422

                 (7) Impacts on Coastal and Marine Birds

                      The sources and severity of impacts to coastal and marine birds associated with the proposed action in the
                 WPA are those sale-related activities discussed for the Base Case in the CPA. As noted in Section IV.D.La.(7)
                 for the Base Case, effects on coastal and marine birds could come from oil spills, disturbance from OCS
                 service-vessel and helicopter traffic, displacement from onshore pipeline landfalls and facility construction, and
                 entanglement and ingestion of offshore oil- and gas-related plastic debris. A more detailed discussion of the
                 potential effects from these impact-producing factors is found in Section IV.D.La.(7).
                      Sections providing supportive material for the coastal and marine bird analysis include Sections III.B.5.
                 (description of coastal and marine birds), IV.C. 1. and 3. (oil spills), IV.A.2.c. (support activities), IV.A_3.a.(1)
                 (service and construction facilities), and IV.A-2.d.(9) (loss of trash and debris).
                      When an oil spill occurs, many factors interact to delimit the severity of effects and the extent of damage
                 to coastal and marine bird populations. The direct effect of oiling on birds occurs through the matting of
                 feathers and subsequent loss of body insulation and water-repellency, the ingestion of oil, the depression of egg-
                 laying activity, and the reduction of hatching success. The impacts from spills less than 1,000 bbl differ in
                 severity and kind from those of spills greater than or equal to 1,000 bbl.
                      Rehabilitation of oiled birds and deterrence away from the immediate area of an oil spill are procedures
                 proven to limit the severity of the effect and lessen the extent of damage to populations of coastal and marine
                 birds. Survival of rehabilitated oiled birds varies from 30 to 90 percent.
                      Disturbance created from OCS-related service-vessel traffic could affect coastal and marine birds, resulting
                 in reduced use or desertion of coastal feeding, resting, or breeding/nesting habitats. Helicopter traffic that is
                 OCS-related could disturb feeding, resting, or breeding/nesting behavior of birds or cause abandonment of
                 preferred habitat. Disturbance by either service-vessel or helicopter traffic could contribute to population losses
                 by relocation of birds to areas where they may experience increased environmental or physiological stress.
                      Pipeline landfalls and coastal construction can displace coastal and marine birds from coastal feeding,
                 resting, or nesting habitats. Dredging can displace coastal and marine birds, and the resultant habitat may be
                 so changed that it is no longer suitable as feeding, resting, or nesting habitat. Coastal construction can alter
                 coastal habitat to the extent that the area can no longer be suitable as feeding, resting, or breeding/nesting
                 habitat for coastal and marine birds. Displacement can contribute to population losses by relocation of birds
                 to areas where they may experience increased environmental or physiological stress.
                      Coastal and marine birds can also be adversely affected by entanglement or ingestion of OCS-related trash
                 and debris. The MMS prohibits the disposal of materials into offshore waters by lessees (30 C FR 250.40). In
                 addition, MARPOL, Annex V, Public Law 100-220 (101 Statute 1458), which prohibits the disposal of plastic
                 at sea, went into effect January 1, 1989.

                 (a) Nonendangered and Nonthreatened Species

                 Base Case Ana4uis

                      The Gulf of Mexico is populated by migrant and nonmigrant species of coastal and marine birds. This
                 broad category consists of four main groups: seabirds, waterfowl, wading birds, and shorebirds.
                      The major impact-producing factors analyzed below are related to the proposed action and include oil
                 spills, OCS helicopter and service-vessel traffic, pipeline landfalls and coastal facility construction, and oil- and
                 gas-related plastic debris.
                      In the event that oiling of coastal and marine birds should occur from sale-related spills, the effect of any
                 oiling is assumed to be lessened due to the nature of Southern Louisiana Crude: directly, by its chemical
                 composition and traits; and indirectly, by an increase in the percentage of survival from rehabilitation efforts.
                 The effect of spilled oil on coastal and marine birds is assumed to result in a partial, short-term decrease in
                 a local population within the vicinity of spilled oil.
                      In the event that sale-related oil spills should occur in critical feeding habitats of coastal and marine birds,
                 sublethal and some lethal effects are assumed. Sublethal effects are assmed to be lessened by deterrence of











                                                                                                                                IV-423

                 birds away from the oiled area and improved coastal oil-spill contingency planning and response (Section
                 IV.C.5.). Sublethal effects of spilled oil within critical feeding habitats of coastal and marine birds are assumed
                 to result in a partial, short-term decrease in a local population within the vicinity of the affected feeding
                 habitats.
                      Section IV.C.1. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                 in the WPA_ It is assumed that 8 offshore spills and fewer than 10 onshore spills greater than 1 and less than
                 or equal to 50 bbl will occur during the 35-year life of the proposed action. None of the offshore spills will
                 contact the coastline. It is assumed that no spill greater than 50 and less than 1,000 bbl will occur during the
                 35-year life of the proposed action as a result of the proposed action. For the purpose of this analysis, it is
                 estimated that spills less than 1,000 bbl will rarely contact and affect feeding, resting, or nesting habitats. The
                 effect to Gulf coastal and marine birds is assumed to be negligible.
                      Section IV.C.l. estimates the mean number of oil spills greater than or equal to 1,000 bbI resulting from
                 the proposed action in the WPA. It is assumed that no crude oil spill greater than or equal to 1,000 bbl will
                 occur and contact feeding, resting, or nesting habitat of coastal and marine birds in the WPA. For the purpose
                 of this analysis, it is estimated that an OCS oil spill greater than or equal to 1,000 bbl will not interact with Gulf
                 coastal and marine birds or their feeding, resting, or nesting habitats.
                      The majority of coastal and marine bird feeding habitats occur nearshore. It is assumed that no crude oil
                 spills greater than or equal to 1,000 bbl will occur and contact nearshore feeding habitats in the WPA_ For
                 the purpose of this analysis, it is estimated that an OCS oil spill greater than or equal to 1,000 bbl win not
                 interact with Gulf coastal and marine birds or their nearshore feeding habitats.
                      It is assumed that no spills greater than or equal to 1,000 bbl, originating from OCS tankering, will occur
                 and contact a Western Gulf bay, estuary, or nearshore area. For the purpose of this analysis, it is estimated
                 that a oil spill greater than or equal to 1,000 bbl and originating from OCS tankering will not interact with Gulf
                 coastal and marine birds or their feeding, resting, or nesting habitats.
                      Helicopter and service-vessel traffic related to OCS activities could disturb feeding, resting, or nesting
                 behavior of birds or cause abandonment of preferred habitat. This impact-producing factor could contribute
                 to population losses by displacement of birds to areas where they may experience increased environmental or
                 physiological stress. The FAA Advisory Circular 91-36C prohibits the use of fixed-wing aircraft lower than an
                 elevation of 152 in and helicopters lower than 300 m during the period of October 15 through April 15 in the
                 vicinity of numerous national wildlife refuges along the Gulf of Mexico in order to prevent disturbances to the
                 birds (Biological Opinion - Section 7 Consultation, Proposed Exploration Plans for OCS in the Gulf of Mexico;
                 FWS/OES 375.0). The majority of these wildlife refuges provide important feeding, resting, and nesting areas
                 for coastal and marine birds. Although an incident may occur and be disruptive, the effect is, at worst, of a
                 temporary nature. It is assumed that helicopter traffic will not disturb Gulf coastal and marine birds because
                 of special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 in. For the
                 purpose of this analysis, it is estimated that OCS-related flights at the appropriate altitude will rarely disturb
                 Gulf coastal and marine birds. The effect on Gulf coastal and marine birds is assumed to be negligible.
                      It is assumed that about 237 OCS-related oil and gas service-vessel trips will occur annually as a result of
                 the proposed action and that 66 shuttle tanker trips will occur during the 35-year life of the proposed action
                 (Table IV-3). For the purpose of this analysis, it is estimated that service-vessel traffic will rarely disturb
                 feeding, resting, or nesting habitats. The effect on Gulf coastal and marine birds will be negligible.
                      Disturbance of coastal and marine bird nesting and feeding habitats from pipeline landfalls and onshore
                 construction could result in a reduction of or desertion by birds that use the habitats. It is assumed that no
                 new OCS oil- and gas-related pipeline landfalls or coastal facilities will be constructed as a result of the
                 proposed action in the WPA (Section IV.A.3.b.). For the purpose of this analysis, it is estimated that pipeline
                 landfalls and onshore construction will not interact with feeding, resting, or nesting habitats of Gulf coastal and
                 marine birds.
                      Coastal and marine birds can become entangled in or ingest trash and debris. Interaction with plastic
                 materials can be especially injurious and cause mortalities. It is assumed that coastal and marine birds will
                 seldom become entangled in or ingest OCS-related trash and debris. The MMS prohibits the disposal of
                 equipment, containers, and other materials into offshore waters by lessees (30 CFR 250.40). In addition,
                 MARPOL, Annex V, Public Law 100-220 (101 Statute 1458), which prohibits the disposal of any plastics at sea










                  IV-424

                  or in coastal waters, went into effect January 1, 1989. For the purpose of this analysis, it is esainiated that OCS
                  oil- and gas-related plastic debris will rarely interact with Gulf coastal and marine birds, and the effect will be
                  negligible.

                  Summary

                       Activities resulting from the proposed action have the potential to affect Western Gulf coastal and marine
                  birds detrimentally. It is estimated that the effects from the major impact-producing factors on coastal and
                  marine birds are negligible and of nominal occurrence. As a result, there will no perceivable disturbance to
                  Gulf coastal and marine birds.


                  Conclusion


                       The impact of the Base Case scenario on nonendangered and nonthreatened coastal and marine birds
                  within the potentially affected area is assumed to result in no discernible decline in a population or species,
                  and no change in distribution and/or abundance on a local or regional scale. Individuals experiencing sublethal
                  effects will recover to predisturbance condition in less than one generation.

                  High Case Analysis

                       The major impact-producing factors analyzed below are related to the proposed action and include oil
                  spills, OCS helicopter and service-vessel traffic, pipeline landfalls and coastal facility construction, and off- and
                  gas-related plastic debris.
                       In the event that oiling of coastal and marine birds should occur from sale-related spills, the effect of any
                  oiling is assumed to be lessened due to the nature of Southern Louisiana Crude: directly, by its chemical
                  composition and traits; and indirectly, by an increase in the percentage of survival from rehabilitation efforts.
                  The effect of spilled oil on coastal and marine birds is assumed to result in a partial, short-terin decrease in
                  a local population within the vicinity of spilled oil.
                       In the event that sale-related oil spills should occur in critical feeding habitats of coastal and marine birds,
                  sublethal effects are assumed. These are assumed to be lessened by deterrence of birds away from the oiled
                  area and improved coastal oil-spill contingency planning and response (Section IV.C.6.). Sublethal effects of
                  spilled oil within critical feeding habitats of coastal and marine birds are assumed to result in a partial, short-
                  term decrease in a local population within the vicinity of the affected feeding habitats.
                       Section IV.C.l. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                  in the WPA. It is assumed that 20 offshore spills and fewer than 10 onshore spills greater than I and less than
                  or equal to 50 bbl will occur during the 35-year life of the proposed action. None of the offshore spills win
                  contact the coastline. It is assumed that one offshore spill greater than 50 and less than 1,000 bbl will occur
                  during the 35-year life of the proposed action and that it will not contact the coastline. For the purpose of this
                  analysis, it is expected that spills less than 1,000 bbl will rarely contact and affect feeding, resting, or nesting
                  habitats, and that the effect on Gulf coastal and marine birds is assumed to be negligible.
                       Section IV.C.I. estimates the mean number of oil spills greater than or equal to 1,000 bbl resulting from
                  the proposed action in the WPA_ It is assumed that one crude oil spill greater than or equal to 1,000 bbl win
                  occur from either a platform or pipeline in the Western Gulf during the 35-year life of the proposed action.
                  Table IV-22 identifies the estimated risk of one or more oil spills greater than or equal to 1,000 bbl occurring
                  and contacting within 10 days coastal and marine birds and their feeding, resting, or nesting habitats. The
                  highest probability of one or more oil spills greater than or equal to 1,000 bbl occurring. and contacting a
                  coastal bay in the Western Gulf within 10 days is 1 percent (Galveston Bay). The highest estlinated probability
                  of one or more spills greater than or equal to 1,000 bbl occurring and contacting Texas coastal marshes within
                  10 days is 1 percent. For the purpose of this analysis, it is expected that an oil spill greater than or equal to
                  1,000 bbl will rarely contact and affect Gulf coastal and marine birds or their feeding, resting, or nesting
                  habitats. The effect to Gulf coastal and marine birds is assumed to be negligible.










                                                                                                                          IV-425

                    The majority of coastal and marine bird feeding habitats occur nearshore. The highest estimated
                probability of one or more spills greater than or equal to 1,000 bbl occurring and contacting nearshore feeding
                habitat (coastline) along the Western Gulf within 10 days is 2 percent. For the purpose of this analysis, it is
                expected that an oil spill greater than or equal to 1,000 bbl will rarely contact and affect nearshore feeding
                habitats. The effect on Gulf coastal and marine birds is assumed to be negligible.
                    It is assumed that no spills greater than or equal to 1,000 bbl originating from OCS tankering will occur
                and contact within 10 days a Western Gulf bay, estuary, or nearshore area. For the purpose of this analysis,
                it is expected that an oil spill greater than or equal to 1,000 bbl from OCS-related activities will not interact
                with Gulf coastal and marine birds or their feeding, resting, or nesting habitats. Therefore, the impact level
                is assume to be very low.
                    Helicopter and service-vessel traffic that is OCS-related could disturb feeding, resting, or nesting behavior
                of birds or cause abandonment of preferred habitat. This impact-producing factor could contribute to
                population losses by displacement of birds to areas where they may experience increased environmental or
                physiological stress. The FAA Advisory Circular 91-36C prohibits the use of fixed-wing aircraft lower than an
                elevation of 152 m and helicopters lower than 300 in during the period of October 15 through April 15 in the
                vicinity of numerous national wildlife refuges in the Gulf of Mexico to prevent disturbances to the birds
                (Biological Opinion - Section 7 Consultation, Proposed Exploration Plans for OCS in the Gulf of Mexico;
                FWS/OES 375.0). The majority of these wildlife refuges provide important feeding, resting, and nesting areas
                for coastal and marine birds. Although an incident may occur and be disruptive, the effect is, at worst, of a
                temporary nature. It is assumed that helicopter traffic will not disturb Gulf coastal and marine birds because
                of special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 in. For the
                purpose of this analysis, it is estimated that OCS-related flights at the appropriate altitude will rarely disturb
                Gulf coastal and marine birds. The effect on Gulf coastal and marine birds is assume to be negligible.
                    It is assumed that about 557 OCS-related oil and gas service-vessel trips will occur during the peak year
                of the proposed action and that 171 shuttle tanker trips will occur during the 35-year life of the proposed action
                (Table IV-3). For the purpose of this analysis, it is estimated that service-vessel traffic will rarely disturb
                feeding, resting, or nesting habitats. The effect on Gulf coastal and marine birds will be negligible.
                    Disturbance of coastal and marine bird nesting and feeding habitats from pipeline landfalls and onshore
                construction could result in a reduction of or desertion by birds that use the habitats. It is assumed that no
                new OCS off and gas-related pipeline landfalls and one pipeyard will be constructed as a result of the proposed
                action in the WPA (Section IV.A.3.b.). For the purpose of this analysis, it is estimated that pipeline landfalls
                and onshore construction will not interact with feeding, resting, or nesting habitats of Gulf coastal and marine
                birds.
                    Coastal and marine birds can become entangled in or ingest trash and debris. Interaction with plastic
                materials can be especially injurious and cause mortalities. It is assumed that coastal and marine birds will
                seldom become entangled in or ingest OCS-related trash and debris. The MMS prohibits the disposal of
                equipment, containers, and other materials into offshore waters by lessees (30 CFR 250.40). In addition,
                MARPOL, Annex V, Public Law 100-220 (101 Statute 1458), which prohibits the disposal of any plastics at sea
                or in coastal waters, went into effect January 1, 1989. For the purpose of this analysis, it is estimated that OCS
                oil and gas-related plastic debris will rarely interact with seabirds. The effect on Gulf coastal and marine birds
                will be negligible.
                    Activities resulting from the proposed action have the potential to affect Western Gulf coastal and marine
                birds detrimentally. It is estimated that the effects from the major impact-producing factors on coastal and
                marine birds are negligible and of nominal occurrence. As a result, there will no perceivable disturbance to
                Gulf coastal and marine birds.


                Conclusion

                    The impact of the High Case scenario on nonendangered and nonthreatened coastal and marine birds
                within the potentially affected area is assume to result in no discernible decline in a population or species, and
                no change in distribution and/or abundance on a local or regional scale. Individuals experiencing sublethal
                effects will recover to predisturbance condition in less than one generation.










                  IV-426

                  (b) Endangered and Threatened Species

                      This section discusses the effects of the proposed action on endangered and threatened birds, including
                  the brown pelican, Arctic peregrine falcon, bald eagle, and piping plover. It summarizes and incorporates the
                  discussion of the effects on the brown pelican and piping plover in Section IV.13.2.a.(7)(a) (nonendangeredand
                  nonthreatened birds) of this document, and additional information as cited. Oil spills, OCSservice-vessel and
                  helicopter traffic, onshore pipeline construction, and entanglement and ingestion of offshore 6[1- and gas-related
                  plastic debris are sources of potential adverse impacts. The effects on birds from these impact-producing
                  factors are discussed under nonendangered and nonthreatened birds (Section IV.13.2.a.(7)(a)). Any activity
                  that is a result of the proposed action and that results in the mortality of an endangered or threatened bird
                  represents a substantial impact on the species under discussion, as above.

                  Base Case Ana4w&

                      It is assumed that helicopter traffic will occur on a regular basis, averaging about 4,000 trips per year. The
                  FAA Advisory Circular 91-36C prohibits the use of fixed-wing aircraft lower than an elevation of 152 in and
                  helicopters lower than 300 in during the period of October 15 through April 15 in the vicinity of numerous
                  national wildlife refuges in the Gulf of Mexico to prevent disturbances to the birds (Biological Opinion - Section
                  7 Consultation, Proposed Exploration Plans for OCS in the Gulf of Mexico; FWS/OES 375.0). The majority
                  of these wildlife refuges provide important critical habitats (feeding, resting, or nesting areas) for endangered
                  and threatened species. Although interactions may occur and be disruptive, effects are expected to be sublethal
                  and, at worst, of a temporary nature. It is estimated that helicopter traffic near critical feeding, resting, or
                  nesting areas will rarely disturb the brown pelican, Arctic peregrine falcon, bald eagle, or piping plover because
                  of special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 m.
                      It is assumed that about 237 OCS-related oil and gas service-vessel trips win occur as a result of the
                  proposed action and that 66 shuttle tanker trips will occur during the 35-year life of the proposed action (Table
                  IV-3). Most of the OCS-related oil and gas traffic occurs in and out of areas that are well away from critical
                  habitats (feeding, resting, or nesting areas) for the Arctic peregrine falcon, bald eagle, or piping plover. Some
                  OCS-related service vessel traffic occurs in the vicinity of Port O'Connor, Freeport, Galveston,, and Sabine Pass,
                  Texas, within several miles of critical habitats (feeding, resting, or nesting areas) for the brown pelican.
                  Although incidents may occur and be disruptive, effects are expected to be sublethal and, at worst, of a
                  temporary nature. It is estimated that service-vessel traffic will rarely disturb the brown pellican.
                      Disturbance of brown pelican, Arctic peregrine falcon, and piping plover critical feeding, resting, or nesting
                  habitats from pipeline landfalls and onshore construction could result in a reduction or desertion of birds that
                  use the habitats. It is assumed that no new OCS oil- and gas-related pipeline landfalls or coastal facilities will
                  be constructed as a result of the proposed action in the WPA (Section IV.A.3.b.). It is estimated that pipeline
                  landfalls and onshore construction will not interact with critical feeding, resting, or nesting habitats of the brown
                  pelican, Arctic peregrine falcon, or piping plover.
                      The brown pelican, Arctic peregrine falcon, bald eagle, and piping plover can become entangled in or
                  ingest trash and debris. Interaction with plastic materials can be especially injurious. The MMS prohibits the
                  disposal of equipment, containers, and other materials into offshore waters by lessees (30 CFR 250.40). In
                  addition, NLARPOL, Annex V, Public Law 100-220 (101 Statute 1458), which prohibits the disposal of any
                  plastics at sea or in coastal waters, went into effect January 1, 1989. It is assumed that very little trash and
                  debris will be lost into the Gulf of Mexico as a result of the proposed action. Although interactions may occur,
                  effects are expected to be sublethal. It is estimated that the brown pelican, Arctic peregrine falcon, bald eagle,
                  and piping plover will rarely become entangled in or ingest OCS-related trash and debris.
                      When an oil spill occurs, many factors interact to delimit the severity of effects and the extent of damage
                  to endangered and threatened birds. Determining factors include geographic location, oil type, oil dosage,
                  impact area, oceanographic conditions, meteorological conditions, and season (NRC, 1985:; USDOI, MMS,
                  1987b). The direct effect of oiling on birds occurs through the matting of feathers and subsequentloss of body
                  insulation and water-repellency, the ingestion of oil, the depression of egg-laying activity, and the reduction of











                                                                                                                              IV-427

                hatching success (Holmes and Cronshaw, 1977; Ainley et al., 1981; Peakall et al., 1981). Transfer of off from
                adults to eggs and young during nesting results in significant mortality for new eggs and deformities in
                hatchlings from eggs further along in incubation (Clapp et al., 1982a). Indirect effects of oil spills include
                contamination, displacement, and reduction of food sources. Food contamination may cause less severe,
                sublethal effects decreasing survival and fecundity, affecting behavior, and decreasing survival of young. Less
                severe, sublethal effects are defined as those that impair the ability of an organism to function effectively
                without causing direct mortality (NRC, 1985).
                    In the event that oiling of the brown pelican, Arctic peregrine falcon, bald eagle, or piping plover should
                occur from sale-related oil spills greater than or equal to 1,000 bbl, the effects would primarily be sublethal;
                few mortalities are assumed. The effects of sale-related oil spills less than 1,000 bbl are assumed to be solely
                sublethal due to the inconsiderable area affected. In the event that sale-related oil spills of any size should
                occur in critical habitats for feeding, resting, or nesting, such as inshore, intertidal, and nearshore areas,
                sublethal effects are assumed. It is assumed that the extent and severity of effects from sale-related oil spills
                of any size will be lessened by improved coastal oil-spill contingency planning and response, deterrence of birds
                away from the immediate area of an oil spill, and increased percentage of survival from rehabilitation efforts
                (Section IV.C.5.).
                    Section IV.C.1. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                in the WPA_ It is assumed that 8 offshore spills and fewer than 10 onshore spills greater than 1 and less than
                or equal to 50 bbl will occur during the 35-year life of the proposed action. None of the spills will contact the
                coastline. It is assumed that no spill greater than 50 and less than 1,000 bbl will occur during the 35-year life
                of the proposed action. It is estimated that spills less than 1,000 bbl will not interact with the brown pelican,
                Arctic peregrine falcon, bald eagle, and piping plover.
                    Section IV.C.1. estimates the mean number of spills greater than or equal to 1,000 bbI resulting from the
                proposed action in the WPA. It is assumed that no crude oil spill greater than or equal to 1,000 bbl will occur
                from a platform, pipeline, or OCS tankering in the Western Gulf during the 35-year life of the proposed action.
                It is estimated that an oil spill greater than or equal to 1,000 bbl will not interact with the brown pelican, Arctic
                peregrine falcon, bald eagle, and piping plover in the WPA_
                    Some critical feeding habitats of the brown pelican, Arctic peregrine falcon, and piping plover occur
                nearshore. It is assumed that no crude oil spills greater than or equal to 1,000 bbl will occur and contact
                critical feeding habitats (nearshore areas) in the Western Gulf. It is estimated that an oil spill greater than or
                equal to 1,000 bbI will not interact with nearshore areas (coastline) critical to the feeding of the brown pelican,
                Arctic peregrine falcon, and piping plover.

                Summary

                    The brown pelican, Arctic peregrine falcon, bald eagle, and piping plover may be impacted by helicopter
                and service-vessel traffic, onshore pipeline landfalls, entanglement in and ingestion of offshore oil- and gas-
                related plastic debris, and oil spills. The effects of these activities are estimated to be sublethal. Lethal effects
                are estimated only from oil spills greater than or equal to 1,000 bbl. Sale-related oil spills of any size are
                estimated to be extraordinary events that will rarely contact threatened and endangered birds or their critical
                feeding, resting, or nesting habitats.

                Conclusion


                    The impact of the Base Case scenario on endangered and threatened birds within the potentially affected
                area is assumed to result in no discernible decline in a population or species, and no change in distribution
                and/or abundance on a local or regional scale. Individuals experiencing sublethal effects will recover to
                predisturbance condition in less than one generation.











                    IV-428

                    High Case Ana4uis

                        It is assumed that helicopter traffic will occur on a regular basis, averaging about 10,000 trips per year.
                    The FAA Advisory Circular 91-36C prohibits the use of fixed-wing aircraft lower than an elevation of 152 M.
                    and helicopters lower than 300 m during the period of October 15 through April 15 in the vicinity of numerous
                    national wildlife refuges in the Gulf of Mexico to prevent disturbances to the birds (Biologi(al Opinion-Section.
                    7 Consultation, Proposed Exploration Plans OCS in the Gulf of Mexico; FWS/OES 375.0). The majority of
                    these wildlife refuges provide critical habitats (feeding, resting, or nesting areas) for endangered and threatened
                    species. Although interactions may occur and be disruptive, effects are expected to be sublethal and, at worst,
                    of a temporary nature. It is estimated that helicopter traffic near critical habitats (feeding., resting, or nesting
                    areas) will rarely disturb the brown pelican, Arctic peregrine falcon, bald eagle, or piping, plover because oil'
                    special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 in.
                      . It is assumed that 557 OCS-related oil and gas service-vessel trips will occur as a result of the proposecl
                    action and that 171 shuttle tanker trips will occur during the 35-year life of the proposed action (Table IV-3).
                    Most of the OCS-related oil and gas traffic occurs in and out of areas that are well away from critical habitats
                    for feeding, resting, or nesting areas of the Arctic peregrine falcon, bald eagle, or piping plover. Some OCS.-
                    related service vessel traffic occurs in the vicinity of Port O'Connor, Freeport, Galveston, and Sabine Pass,
                    Texas, within several miles of critical feeding, resting, or nesting areas for the brown pelican. Although
                    incidents may occur and be disruptive, effects are expected to be sublethal and, at worst, of a temporary nature.
                    It is estimated that service-vessel traffic will rarely disturb the brown pelican.
                        Disturbance of brown pelican, Arctic peregrine falcon and piping plover critical feeding, resting, or nesting
                    habitats from pipeline landfalls and onshore construction could result in a reduction or desertion of birds that
                    use the habitats. It is assumed that no new OCS oil- and gas-related pipeline landfalls or coastal facilities will,
                    be constructed as a result of the proposed action in the WPA (Section IV.A-3.b.). It is estimated that pipeline
                    landfalls and onshore construction will not interact with critical feeding, resting, or nesting habitats of the brown
                    pelican, Arctic peregrine falcon, or piping plover.
                        The brown pelican, Arctic peregrine falcon, bald eagle, and piping plover can become entangled in or
                    ingest trash and debris. Interaction with plastic materials can be especially injurious. The MMS prohibits the
                    disposal of equipment, containers, and other materials into offshore waters by lessees (30 CFR 250.40). In
                    addition, MARPOL, Annex V, Public Law 100-220 (101 Statute 1458), which prohibits the disposal of any
                    plastics at sea or in coastal waters, went into effect January 1, 1989. It is assumed that very little trash and
                    debris will be lost into the Gulf of Mexico as a result of the proposed action. Although interactions may occur,
                    effects are expected to be sublethal. It is estimated that the brown pelican, Arctic peregrine falcon, bald eagle,.
                    and piping plover will rarely become entangled in or ingest OCS-related trash and debris.
                        In the event that oiling of the brown pelican, Arctic peregrine falcon, bald eagle, or piping plover should
                    occur from sale-related oil spills greater than or equal to 1,000 bbl, the effects would primarily be sublethal;
                    few mortalities are assumed. The effects of sale-related oil spills less than 1,000 bbl are assumed to be
                    sublethal. In the event that sale-related oil spills of any size should occur in critical feeding, resting, or nesting,
                    habitats, such as inshore, intertidal, and nearshore areas, of the brown pelican, Arctic peregrine falcon, and
                    piping plover, sublethal effects are assumed. The extent and severity of effects from sale-related oil spills will
                    be lessened by improved coastal oil-spill contingency planning and response, deterrence of birds away from the
                    oiled area, and increased percentage of survival from rehabilitation efforts (Section IV.C.5.).
                        Section IV.C.1. estimates the mean number of spills less than 1,000 bbl occurring from the proposed action
                    in the WPA. It is assumed that 20 offshore spills and fewer than 10 onshore spills greater than 1 and less than
                    or equal to 50 bbl will occur during the 35-year life of the proposed action. None of the spills will contact the
                    coastline. It is assumed that 1 offshore spill greater than 50 and less than 1,000 bbl will occur during the 35-
                    year life of the proposed action and that it will not contact the coastline. Although an interaction with spills
                    less than 1,000 bbI may occur, only sublethal effects are assumed. It is estimated that small spills will seldom
                    contact and affect the brown pelican, Arctic peregrine falcon, bald eagle, and piping plover.
                        Section IV.C.1. estimates the mean number of oil spills greater than or equal to 1,000 bbl resulting from
                    the proposed action in the WPA. It is assumed that one crude oil spill greater than or equal to 1,000 bbl will
                    occur from either a platform or pipeline in the Western Gulf during the 35-year life of the proposed action..










                                                                                                                              IV429

                Table IV-22 identifies the estimated risk of one or more oil spills greater than or equal to 1,000 bbl occurring
                and contacting within 10 days critical habitats for feeding, resting, or nesting of the brown pelican, Arctic
                peregrine falcon, bald eagle, and piping plover in the WPA. The highest probability of one or more oil spills
                greater than or equal to 1,000 bbl occurring and contacting within 10 days a coastal bay in the Western Gulf
                is 1 percent (Galveston Bay). The highest estimated probability of one or more spills greater than or equal
                to 1,000 bbl occurring and contacting Texas coastal marshes within 10 days is I percent. Although an
                interaction with spills greater than or equal to 1,000 bbl may occur, primarily sublethal effects are expected with
                infrequent mortalities. It is estimated that an oil spill greater than or equal to 1,000 bbl will rarely contact and
                affect the brown pelican, Arctic peregrine falcon, bald eagle, and piping plover in the WPA.
                     Some feeding habitats of the brown pelican, Arctic peregrine falcon, and piping plover occur nearshore.
                The highest estimated probability of one or more spills greater than or equal to 1,000 bbl occurring and
                contacting within 10 days nearshore areas (coastline) along the Western Gulf is 2 percent. Although an
                incident may occur, sublethal effects are assumed. It is estimated that an oil spill greater than or equal to 1,000
                bbl will rarely contact and affect nearshore areas (coastline) critical to the feeding of the brown pelican, Arctic
                peregrine falcon, and piping plover.
                     The brown pelican, Arctic peregrine falcon, bald eagle, and piping plover may be impacted by helicopter
                and service-vessel traffic, onshore pipeline landfalls, entanglement in and ingestion of offshore oil- and gas-
                related plastic debris, and oil spills. The effects of these activities are estimated to be sublethal. Lethal effects
                are estimated only from oil spills greater than or equal to 1,000 bbl. Sale-related oil spills of any size are
                estimated to be extraordinary events that will rarely contact threatened and endangered birds or their critical
                habitats for feeding, resting, or nesting habitats.

                Conclusion


                     The impact of the High Case scenario on endangered and threatened birds within the potentially affected
                area is assumed to result in no discernible decline in a population or species, and no change in distribution
                and/or abundance on a local or regional scale. Individuals experiencing sublethal effects will recover to
                predisturbance condition in less than one generation.

                (8) Impacts on Commercial Fisheries

                     The sources and severity of impacts to commercial fisheries in the WPA are the same as those discussed
                for the Base Case in the CPA- As noted in Section IV.D.l.a.(9) for the Base Case, effects on commercial
                fisheries could come from emplacement of production platforms, underwater OCS obstructions, production
                platform removals, seismic surveys, oil spills, subsurface blowouts, and OCS discharges of drilling muds. A
                more detailed discussion of the potential effects from these impact-producing factors can be found in Section
                IV.D.La.(9).
                     Sections providing supportive material for the commercial fisheries analysis include Sections III.B.6.
                (description of fish resources), III.C.3. (commercial fishing stocks and activities), IV.A.2.d.(3) (use conflicts),
                IV.A.2.b.(l) (pipelines), IV.A.2.a.(3) (structure removal), IV.A_2.a.(1) (seismic operations), IV.C.1. and 3. (oil
                spills), IV.A-2.d.(8) (subsurface blowouts), IV.A.2.d.(5) (offshore discharges), IV.A-3.c.(5) (onshore discharges),
                and IV.D.I.a.(9) (impacts on Central Gulf commercial fisheries).
                     The emplacement of a production platform, with a surrounding 100-m navigational safety zone, results in
                the loss of approximately 6 ha of bottom trawling area to commercial fishermen and causes space-use conflicts.
                Gear conflicts from underwater OCS obstructions such as pipelines result in losses of trawls and shrimp catch,
                business downtime, and vessel damage.
                     Lessees are required to remove all structures and underwater obstructions from their leases in the Federal
                OCS within one year of the lease's relinquishment or termination. The great majority of platforms are removed
                with subbottom plastic explosives. There is concern over a possible connection between the lethal effects of
                platform removals to reef fish and declines in reef fish populations in the Gulf.










                 IV-430

                     The sources of acoustical pulse used in seismic surveys are generated by airguns. Airguns have little effect
                 on even the most sensitive fish eggs at distances of 5 in from the discharge.
                     When an oil spill occurs, many factors interact to delimit the severity of effects and the extent of damage
                 to commercially important fish populations. The direct effects of spilled oil on fish occur through the ingestion
                 of off or oiled prey, the uptake of dissolved petroleum products by adults and juveniles, and ibrough mortality
                 of eggs and decreased survival of larvae. The effects from chronic or small oil spills differ in severity and kind
                 from those of spills greater than or equal to 1,000 bbl.
                     The effects on and the extent of damage from an oil spill to Gulf commercial fisheries are restricted by
                 time and location. For OCS-related oil spills to have a substantial effect on a commercial fishery resource, a
                 large number of eggs and larvae would have to be concentrated in the immediate spill area. Oil components
                 also would have to be present in highly toxic concentrations during the time when both eggs and larvae were
                 in the pelagic stage (Longwell, 1977).
                     Subsurface off- and natural gas-well blowouts resuspend sediments and release varying amounts of
                 hydrocarbons into the water column (USDOI, MMS, 1987a). Both effects may be detrimental to commercial
                 fishery resources.
                     Commercial fishery resources could also be adversely affected by the discharge of drilling muds. Drilling
                 muds contain materials toxic to marine fishes; however, dilution is extremely rapid in offshore waters.

                 Base Case Ana4u&

                     The major impact-producing factors analyzed below are related to the proposed action and include
                 underwater OCS obstructions, OCS drilling mud discharge, production platform removal, production platform
                 emplacement, seismic surveys, oil spills, and subsurface blowouts.
                     Gear conflicts are caused by underwater OCS obstructions such as pipelines. Section INI.A.4.b. estimates
                 the kilometers of new offshore pipeline resulting from the proposed action in the WPA_ It is expected that
                 80 kin of pipeline will be installed in the WPA during the 35-year life of the proposed act[on (Table IV-3).
                 In Subarea W-1, the area of concentrated bottom trawl fishing, only 10 percent, or 8 km, of pipeline will be
                 installed during the 35-year life of the proposed action. Gear conflicts are mitigated by the FCF. During Fiscal
                 Year (M 1990, 198 claims were processed, with 77 percent being approved for a total of $836,799. The
                 economic loss from gear conflicts for FY 90 was less than 0.2 percent of the value ($640 million) of Gulf
                 commercial fisheries landings for 1990. For the purpose of this analysis, it is expected that installed pipelines
                 will rarely conflict with bottom trawl fishing and will have a negligible effect on Western Gulf fisheries.
                     Drilling mud discharges (Table IV-3) contain chemicals toxic to marine fishes; however, this is only at
                 concentrations four or five orders of magnitude higher than those found more than 300 in from the discharge
                 point. Offshore discharges of drilling muds will rapidly dilute to background levels and havea negligible effect
                 on Western Gulf fisheries.
                     Structure removal results in artificial habitat loss and causes fish kills when explosives are used. Table IV-3
                 estimates that three structure removals using explosives will occur in the WPA during the 3.5-year life of the
                 proposed action. It is assumed that these removals will occur during the last 12 years of the life of the
                 proposed action and no more than one in any given year. For the purpose of this analysis, it is estimated that
                 structure removals will have a negligible effect on Western Gulf fisheries because removals will be rare events
                 that kill only those fish proximate to the removal site.
                     Ten offshore platform complexes (Table IV-3) are expected to result from the proposed action, eliminating
                 300 ha (741 ac) of the trawling area during the 35-year life of the proposed action in the VVPA. In subarea
                 W-1, the area of concentrated bottom trawl fishing, only one platform complex will be installed, eliminating
                 15 ha (37 ac). For the purpose of this analysis, it is estimated that space-use conflicts are rare. The effect of
                 space lost to trawl fishing in the Gulf from the construction of platforms is negligible because, the extent of the
                 area lost to commercial trawling is less than 0.01 percent of the available trawl fishing area in either Subarea
                 W-1 or in the WPA_
                     Seismic surveys will occur in both coastal and offshore areas of the WPA. For purposes of this analysis,
                 it is assumed that seismic surveys will have a negligible effect on Gulf commercial fiLsheries because of the
                 prevalent use of airguns (Section IV.A-2.).











                                                                                                                           IV-431

                    In the event that sale-related oil spills should occur in coastal bays, estuaries, and waters of the OCS
               proximate to mobile adult finfish or shellfish, the effects and the extent of damage are expected to be limited
               and lessened due to some capability of adult fish to avoid an oil spill and to metabolize hydrocarbons and to
               excrete both metabolites and parent compounds from their gills and liver. For floating eggs and larvae
               contacted by spilled oil, the effect is expected to be lethal. The effect of off spills on commercial fishery
               resources is expected to result in a partial, long-term decrease in a commercial population, in an essential
               habitat, or in local fishing activity.
                    Section IV.C.1. estimates the mean number of oil spills less than 1,000 bbI resulting from the proposed
               action in the WPA. It is assumed that eight spills greater than 1 and less than or equal to 50 bbI will occur
               during the 35-year life of the proposed action and that none of the offshore spills will contact the coastline.
               It is assumed that no spill greater than 50 and less than 1,000 bbI will occur during the 35-year life of the
               proposed action. For the purpose of this analysis, it is estimated that spills less than 1,000 bbI will rarely
               contact and affect the coastal bays and marshes critical to the well-being of commercial fisheries in the WPA.
               The effect on Gulf commercial fisheries is expected to be negligible.
                    Section IV.C.1. estimates the mean number of oil spills greater than or equal to 1,000 bbl resulting from
               the proposed action in the WPA_ It is assumed that no crude oil spills greater than or equal to 1,000 bbI will
               occur and contact the coastal bays and marshes critical to the well-being of commercial fisheries in the WPA_
               For the purpose of this analysis, it is estimated that an OCS oil spill greater than or equal to 1,000 bbI will not
               interact with Gulf commercial fisheries. .
                    Although the quantity of commercial landings in the WPA of migratory species is comparatively small,
               these species are of high value. Migratory species could be affected by oil spills occurring in the coastal area.
               It is assumed that no crude oil spills greater than or equal to 1,000 bbl will occur and contact nearshore and
               coastal areas critical to migratory commercial fisheries in the WPA. For the purpose of this analysis, it is
               estimated that an OCS oil spill greater than or equal to 1,000 bbl will not interact with Gulf commercial
               fisheries.
                    Oil spills greater than or equal to 1,000 bbl originating in port from OCS-related tankering include those
               that may occur and contact coastal bays, estuaries, and nearshore areas. It is assumed that no spills greater
               than or equal to 1,000 bbl originating from tankering will occur and contact a Western Gulf bay, estuary, or
               nearshore area. For the purpose of this analysis, it is estimated that an oil spill greater than or equal to 1,000
               bbl and that is OCS-related will not interact with Gulf commercial fisheries.
                    Subsurface blowouts of both oil and natural gas wells are detrimental to commercial fishery resources.
               Loss of well control and resultant blowouts are rare on the Gulf OCS (only 157 out of approximately 27,000
               exploration and development wells since 1956, with 12 resulting in the release of more than one barrel of oil).
               It is assumed that there will be 2 blowouts in the WPA resulting from the proposed action during the 35-year
               life of the proposed action. For the purpose of this analysis, it is estimated that the rare subsurface blowout
               on the Gulf OCS will have a negligible effect on Gulf commercial fisheries.

               Summary

                    Activities resulting from the proposed action may detrimentally affect Western Gulf commercial fisheries.
               It is estimated that the effects from the major impact-producing factors on commercial fisheries in the WPA
               are negligible and of nominal occurrence. As a result, there will be no perceivable disturbance to Gulf
               commercial fisheries.


               Conclusion

                    The impact of the Base Case scenario on commercial fisheries within the potentially affected area is
               expected to result in no discernible decrease in a population of commercial importance, its essential habitat,
               or in commercial fisheries on a local scale. Any affected population is expected to recover to predisturbance
               condition in less than one generation.










                  IV432

                  High Case Ana4@@

                       The major impact-producing factors analyzed below are related to the proposed action and include
                  underwater OCS obstructions, OCS drilling mud discharge, production platform removal, prOduction. platform
                  emplacement, seismic surveys, oil spills, and subsurface blowouts.
                       Gear conflicts are caused by underwater OCS obstructions such as pipelines. Section Fv'.A3.b. estimates
                  the kilometers of new offshore pipeline resulting from the proposed action in the WPA_ It is expected that
                  240 km of pipeline will be installed in the WPA during the 35-year life of the proposed action (Table IV-3).
                  In subarea W-1, the area of concentrated bottom trawl fishing, only 3 percent, or 8 km, of pipeline will be
                  installed during the 35-year life of the proposed action. Gear conflicts are mitigated by the FCF. During FY
                  90, 198 claims were processed, with 77 percent being approved for a total of $836,799. This economic loss
                  from gear conflicts for FY 90 was less than 0.2 percent of the value ($640 million) of Gulf commercial fisheries
                  landings for 1990. For the purpose of this analysis, it is expected that installed pipelines will rarely conflict with
                  bottom trawl fishing and will have a negligible effect on Western Gulf fisheries.
                       Drilling mud discharges (Table IV-3) contain chemicals toxic to marine fishes; however, this is only at
                  concentrations four or five orders of magnitude higher than those found more than 300 in firorn the discharge
                  point. Offshore discharges of drilling muds will rapidly dilute to background levels and have a negligible effect
                  on Western Gulf fisheries.
                       Structure removal results in artificial habitat loss and causes fish kills when explosives are used. Table IV-3
                  estimates that six structure removals using explosives will occur in the WPA during the 35-year life of the
                  proposed action. It is assumed that these removals will occur during the last 12 years of the life of the
                  proposed action, with no more than two in any single year. For the purpose of this analysis, it is estimated that
                  structure removals will have a negligible effect on Western.Gulf fisheries because removals will be rare events
                  that kill only those fish proximate to the removal site.
                       Thirty offshore platform complexes (Table IV-3) are expected to result from the proposed action,
                  eliminating 300 ha (741 ac) of trawling area during the 35-year life of the proposed action in the WPA. In
                  Subarea W-1, the area of concentrated bottom trawl fishing, only one platform complex will be installed,
                  eliminating 15 ha (37 ac). For the purpose of this analysis, it is estimated that space-use conflicts are rare.
                  The effect of space lost to trawl fishing in the Gulf from the construction of platforms is negligible because the
                  extent of the area lost to commercial trawling is less than 0.01 percent of the available trawl fishing area in
                  either Subarea W-1 or in the WPA-
                       Seismic surveys will occur in both coastal and offshore areas of the WPA_ For purposes of this analysis,
                  it is assumed that seismic surveys will have a negligible effect on Gulf commercial fisheries because of the
                  prevalent use of airguns (Section MA-2.).
                       In the event that sale-related oil spills should occur in coastal bays, estuaries, and waters of the OCS
                  proximate to mobile adult finfish or shellfish, the effects and the extent of damage are expected to be limited
                  and lessened due to some capability of adult fish to avoid an oil spill and to metabolize hydrocarbons and to
                  excrete both metabolites and parent compounds from their gills and liver. For floating: eggs and larvae
                  contacted by spilled oil, the effect is expected to be lethal. The effect of oil spills on commercial fishery
                  resources is expected to result in a partial, long-term decrease in a commercial population, in an essential
                  habitat, or in local fishing activity.
                       Section MCA. estimates the mean number of oil spills less than 1,000 bbl resulting from the proposed
                  action in the WPA It is assumed that 20 offshore spills greater than 1 and less than or equal to 50 bbl will
                  occur during the 35-year life of the proposed action and that none of the offshore spill; will contact the
                  coastline. It is assumed that one spill greater than 50 and less than 1,000 bbl will occur during the 35-year life
                  of the proposed action, and that it will not contact the coastline. For the purpose of 1:his analysis, it is
                  estimated that small spills will rarely contact and affect the coastal bays and marshes critical to the well-being
                  of commercial fisheries in the WPX and that the effect on Gulf commercial fisheries is expected to be
                  negligible.
                       Section MCA. estimates the mean number of oil spills greater than or equal to 1,000 IN resulting from
                  the proposed action in the WPA_ It is assumed that one crude oil spill greater than or equal to 1,000 bbl will
                  occur from either a platform or pipeline in the Western Gulf during the 35-year life of the proposed action.










                                                                                                                             IV-433

               Table IV-22 identifies the estimated risk of one or more oil spills greater than or equal to 1,000 bbl occurring
               and contacting within 10 days the coastal bays and marshes critical to the well-being of commercial fisheries
               in the WPA. The highest probability of one or more oil spills greater than or equal to 1,000 bbI occurring and
               contacting within 10 days a coastal bay in the Western Gulf is 1 percent (Galveston Bay). The highest
               estimated probability of one or more spills greater than or equal to 1,000 bbl occurring and contacting within
               10 days the Texas coastal marshes is 1 percent. For the purpose of this analysis, it is expected that a oil spill
               greater than or equal to 1,000 bbl will seldom contact and affect the coastal bays and marshes critical to the
               well-being of commercial fisheries in the WPA.
                   Although the quantity of commercial landings in the WPA of migratory species is comparatively small,
               these species are of high value. Migratory species could be affected by oil spills occurring in the coastal area.
               The highest estimated probability of one or more spills greater than or equal to 1,000 bbl occurring and
               contacting within 10 days the nearshore and coastal areas along the Western Gulf is 2 percent. For the
               purpose of this analysis, it is estimated that an oil spill greater than or equal to 1,000 bbI will occur but rarely
               contact and affect nearshore and coastal areas critical to migratory commercial fisheries in the WPA.
                   Oil spills greater than or equal to 1,000 bbl originating in port from OCS-related tankering include those
               that may occur and contact coastal bays, estuaries, and nearshore areas. It is assumed that no spills greater
               than or equal to 1,000 bbl from tankering will occur and contact a Western Gulf bay, estuary, or nearshore
               area. For the purpose of this analysis, it is expected that an off spill greater than or equal to 1,000 bbl and that
               is OCS-related will not interact with Gulf commercial fisheries.
                   Subsurface blowouts of both oil and natural gas wells are detrimental to commercial fishery resources.
               Loss of well control and resultant blowouts are rare on the Gulf OCS (only 157 out of approximately 27,000
               exploration and development wells since 1956, with 12 resulting in the release of more than one barrel of off).
               It is assumed that there will be 5 blowouts in the WPA resulting from the proposed action during the 35-year
               life of the proposed action. For the purpose of this analysis, it is estimated that the rare subsurface blowout
               on the Gulf OCS will have a negligible effect on Gulf commercial fisheries.
                   Activities resulting from the proposed action may detrimentally affect Western Gulf commercial fisheries.
               It is estimated that the effects from the major impact-producing factors on commercial fisheries in the WPA
               are inconsequential and of nominal occurrence. As a result, there will be little perceivable disturbance to Gulf
               commercial fisheries.


               Conclusion


                   The impact of the High Case scenario on commercial fisheries within the potentially affected area is
               expected to result in a partial, short-term decrease in a population of commercial importance, in an essential
               habitat, or in commercial fisheries on a local scale. Any affected population is expected to recover to
               predisturbance condition in one generation.

               (9) Impacts on Recreational Resources and Activities

               (a) Beach Use

                   Section IV.D.l.a.(10)(a) presents a general discussion regarding chronic trash and debris and oil spills
               greater than or equal to 1,000 bbI as the major threats to the use and appreciation of recreational beaches
               exposed to the effects of Gulf of Mexico OCS leasing and development in the WPA. Described also is the
               severity of impact assumed to occur to beach use from interaction with a major oil spill or chronic trash and
               debris. Visual No. 2 identifies the general location of major shorefront recreational beaches along the Texas
               coast










                  IV434

                  Base Case Analysis

                      Exploration and production on blocks leased in the Western Gulf of Mexico, and transportation of
                  produced oil and gas, could lead to oil spills greater than or equal to 1,000 bbI (6% probability) (Table IV-19)
                  throughout the 35-year life of the proposed action (1993-2027). Wind, waves, and currents could cause spills
                  to interact with major shorefront recreational beaches throughout the WPA and CPA.
                      The OSRA estimates (Table IV-22) indicate the proposed action is estimated (less than a 0.05%
                  probability) to result in the occurrence and contact of an oil spill greater than or equal to 1,000 bbl within 10
                  days of an accident with a major recreational beach anywhere in the Gulf region. It is assumed, therefore, for
                  purposes of this analysis that an oil spill greater than or equal to 1,000 bbl will not impact recreational beaches
                  in the VVPA from operations resulting from proposed Sale 143.
                      As noted in Section IV.C.I., one spill in the size class greater than I and less than or equal to 50 bbI is
                  estimated to occur every five years during the 35-year project life. None of these chronic, offshore, sale-related
                  spills is assumed to contact a recreational beach; therefore, no impact to recreational beaches is assumed from
                  this size spill.
                      Some litter from OCS accidents, carelessness, and noncompliance with OCS antipollution regulations and
                  directives is estimated to come ashore on recreational beaches from OCS operations associated with the
                  proposed action. New operational practices and continuing industry training and awareness programs focused
                  on the beach litter problem are expected to minimize the level of indiscriminate and irresponsible trash disposal
                  and accidental loss of solid wastes from OCS oil and gas operations. Recreational beaches in Texas are
                  esimated to be impacted from this waterborne trash. Incremental effects from the proposed action on litter
                  are unlikely to be perceptible by beach users or administrators because the activity from the proposal win
                  constitute only a very small percentage of the existing OCS activity in the WPA and is estimated to be offset
                  by the number of terminating leases in the next 35 years. Litter on recreational beaches from OCS operations
                  will adversely affect the ambience of the beach environment, will detract from the enjoyment of beach activities,
                  and can increase administrative costs on maintained beaches.


                  Summaty

                      Marine debris lost from OCS operations associated with drilling 320 new wells and producing oil and gas
                  from 10 new platform complexes throughout the WPA will occur from time to time; however, the incremental
                  impact from intermittent washup on Texas beaches from proposed Sale 143 should be minimal.

                  Conclusion


                      The proposed action is expected to result in periodic loss of solid waste items estimated to wash up on
                  recreational beaches, which is expected to diminish enjoyment of some beach visits but is unlikely to affect the
                  number or type of visits currently occurring on Texas beaches.

                  High Case Analysis

                      The causes and severity of impacts associated with the High Case scenario would be derived from the same
                  impacting factors identified under the Base Case scenario, above. Included are oil spills and trash and debris.
                      The OSRA estimates (Table IV-22) indicate that, even with more optimistic oil and gras finds from the
                  proposed action, the estimated probability of an oil spill greater than or equal to 1,000 bbl occurring and
                  contacting within 10 days a major recreational beach anywhere in the Gulf region is estimated up to 1 percent
                  chance. As noted in Section IV.C.1., it is assumed that about 1 spill greater than I and less than or equal to
                  50 bbl will occur every two years, but only a small number will occur in proximity to coastal resources, and none
                  will reach the beach.
                      With 690 wells drilled and 30 platform complexes producing oil and gas throughout the life of the proposed
                  action (Table IV-3), it is estimated that the level of accidental and irresponsible trash loss from OCS operations
                  will increase from the Base Case, and most of this solid waste will wind up on Texas' recreational beaches.










                                                                                                                            IV-435


                 Conclusion

                      The proposed action is expected to result in periodic loss of solid waste items estimated to wash up on
                 recreational beaches, which is expected to diminish enjoyment of some beach visits but is unlikely to affect the
                 number or type of visits currently occurring on Texas beaches. Although the level of chronic pollution to Texas
                 beaches is estimated to increase from the Base Case, the level of beach use should not change.

                 (b) Marine Fishing

                      Section IV.D.La.(10)(b) presents a general introductory discussion on how oil and gas production platforms
                 might affect offshore fish and offshore fishing. Described also is the severity of impact is estimated to occur
                 to recreational fishing from oil spills.

                 Base Case Analysis
                      The impacting factors considered in the Base Case analysis and discussed below include platform
                 installations and removals and oil spills.
                      Table IV-3 projects the installation of 10 new platform complexes (25 structures) as the result of proposed
                 Sale 143. Most of these platforms will be emplaced in the first 5-15 years of the 35-year project life and will
                 remain on site for about 20 years prior to termination of production and removal. Only one platform complex
                 is projected for installation in coastal Subarea W-1 (Table IV-3) and could be placed from 10 to 80 mi from
                 shore. The other nine platform complexes will be placed at least 50 mi from shore (coastal Subareas W-2 and
                 W-3) and will have little effect, if any, on marine recreational fishing. Platforms installed in coastal Subarea
                 W-1 that are within 30 mi of shore and near major fishing access areas such as Galveston, Brownsville, or Port
                 Aransas are expected to attract many offshore recreational fishing boats. Fishing success is likely to be much
                 better around oil and gas structures than in most other offshore areas of the WPA- There are about 380
                 platform complexes (Table IV-8) off the Texas coast in Federal waters, and individual platform installations
                 are unlikely to have a major influence on the scope of Texas offshore fishing. However, they could influence
                 individual fishermen who would visit these new platforms during the estimated 20-year platform life span. The
                 one new platform complex installed in coastal Subarea W-1 would replace fishing opportunities being lost by
                 platforms that will be removed in the next 5-10 years and would extend the time offshore platforms continue
                 to be a principal focus of offshore recreational fishing in the WPA.
                      The 10 platform complexes (25 structures) resulting from this sale will be removed towards the end of the
                 project life. Therefore, any nearshore structures placed in coastal Subarea W-1 will be lost as fish-attracting
                 devices accessible to recreational fishermen, and their effect on recreational fishing would be negated.
                 Removal of the structures resulting from this proposal with the use of explosives (80% of installations) will kill
                 or adversely impact the sport fish directly associated with the structure at the time of removal, but Will have
                 no detectable effect on the amount or enjoyment of offshore fishing in general.
                      Even though there is an estimated 6 percent probability in the WPA for an oil spill of 1,000 bbl or greater
                 to occur from the proposed sale (Table IV-19), such a spill is unlikely to impact marine recreational fishing
                 beyond the area of the oil slick during the short time it is detectable on the water. Eight spills greater than
                 1 and less than or equal to 50 bbI are assumed to occur (Table IV-3) and may also temporarily redirect some
                 marine recreational fishing activity.

                 Summary
                      One platform complex (2-3 structures) installed as a result of this proposal within 30 mi of shore is
                 expected to attract fishermen and to improve fishing success in the immediate vicinity of the platform complex
                 for a period of about 20 years. No oil spills greater than or equal to 1,000 bbl are assumed to occur, and the
                 few spills greater than 1 and less than 50 bbl that are assumed will have little or no impact of marine fishing.










                  IV-436


                  Conclusion


                      One platform complex (2-3 structures) installed as a result of this proposal within 30 mi of shore is
                  expected to attract fishermen and improve fishing success in the immediate vicinity of the platform complex
                  for a period of about 20 years.

                  High Case Ana4uis

                      Under the High Case analysis it is estimated one platform complex (2-3 structures), the same number
                  projected for the Base Case, will be installed in coastal Subarea W-1 (Table IV-3). This complex could be
                  placed within 10 to 30 mi of shore and become a popular fishing location for offshore marine recreational
                  fishermen. The number of projected platform complexes in offshore Subarea W-2 will increase from 2 to 5,
                  and in offshore Subarea W-3 from 7 to 24. These additional structures will function as artificial reefs and
                  attract sport fish, but are unlikely to have much impact on offshore recreational fishing be(ause they will be
                  located over 50 mi from shore.
                      The estimated probability of an off spill greater than or equal to 1,000 bbl occurring increases from 6 to
                  16 percent under the High Case scenario (Table IV-19). However, the general effect of one spill greater than
                  or equal to 1,000 bbI on offshore recreational fishing, if the spill were to occur, is expected not to extend
                  beyond the immediate area and short-term life of the associated slick.

                  Conclusion


                      The High Case scenario will result in the installation of one platform complex (2-3 structures) that should
                  attract offshore recreational fishermen and improve fishing success. The effect of the High Case on
                  recreational fishing is expected to be the same as for the Base Case

                  (10) Imp"ts on Ardwologicd Resources

                      Lease blocks with a high probability for the occurrence of prehistoric, prehistoric and historic, or historic
                  archaeological resources may by found in the Western Gulf. Those blocks with a high probability for
                  prehistoric archaeological resources may be found landward of a line that roughly follows the .45-m bathymetric
                  contour. Those blocks with a high probability for historic archaeological resources have been recently refined
                  as a result of an MMS-funded study (Garrison et al., 1989). A new Notice to Lessees (NTL 91-02) concerning
                  remote-sensing survey methodology and report writing requirements for archaeological resources in the Gulf
                  of Mexico OCS has been issued. Briefly stated, the NTL increases remote-sensing survey linespacing density
                  for historic shipwreck survey to 50 in from the previous 150 in. The NTL also requires submission of an
                  increased amount of magnetometer data to facilitate in-house MMS analysis. Survey and report requirements
                  for prehistoric site survey have not been changed. Since 1974, leases offered have containedan archaeological
                  resource stipulation. Section II.A-l.c.(3) presents a proposed stipulation as a mitigating measure for leases
                  resulting from the proposed action, the impact analysis for which, including the proposed archaeological
                  resource stipulation, is presented below.
                      It should be noted that a rulemaking, which will incorporate the archaeological stipulation into regulation
                  under 30 CFR 250.25, has been proposed. Presently, lessees or operators are required to comply with the
                  remote-sensing survey and report requirements upon invocation of the stipulation by MMS. The proposed
                  rulemaking will convert the stipulation into an operational regulation.
                      Sections providing supportive material for the archaeological resources analysis include Sections III.C.5.
                  (description of archaeological resources), IV.AA (offshore infrastructure), IV.A.5. (onshore infrastructure), and
                  W.C.I. and 3. (oil spills)
                      A number of OCS-related factors may cause adverse impacts to archaeological resources. Damage caused
                  by the placement of drilling rigs, production platforms, pipelines, dredging, and anchoring could destroy artifacts
                  or disrupt the provenance and stratigraphic context of artifacts, sediments, and paleoindicators from which the










                                                                                                                            IV-437

               scientific value of the archaeological resource is derived. Oil spills could destroy the ability to date prehistoric
               sites by radiocarbon dating techniques. Ferromagnetic debris associated with OCS off and gas activities would
               tend to mask magnetic signatures of significant historic archaeological resources.
                    Offshore development could result in an interaction between a drilling rig, platform, pipeline, dredging,
               or anchors and an historic shipwreck. This direct physical contact with a wreck site could destroy fragile ship
               remains, such as the hull and wooden or ceramic artifacts, and could disturb the site context. The result would
               be the loss of archaeological data on ship construction, cargo, and the social organization of the vessers crew,
               and the concomitant loss of information on maritime culture for the time period from which the ship dates.
                    The placement of drilling rigs and production platforms has the physical potential to impact prehistoric
               and/or historic archaeological resources. It is assumed that the standard rig will directly disturb 1.5 ha of soft
               bottom, the average platform 2 ha. Pile driving associated with platform emplacement may also cause sediment
               liquefaction an unknown distance from the piling, disrupting stratigraphy in the area of liquefaction.
                    Pipeline placement has the physical potential to impact prehistoric and/or historic archaeological resources.
               Those pipelines placed in water depths of less than 61 in (200 ft) must be buried. Burial depths of 1 in (3 ft)
               are required with the exception of shipping fairways and anchorage areas, where the requirements are 10 and
               15 ft, respectively.
                    The dredging of new channels, as well as maintenance dredging of existing channels, has the physical
               potential to impact historic shipwrecks (Espey, Huston, & Associates, 1990). There are 23 navigation channels
               that provide OCS access to onshore facilities. It is assumed that one channel in the Western Gulf will have
               to be deepened to provide access for larger offshore boats serving deeper waters.
                    Anchoring associated with platform and pipeline emplacement, as well as service vessel and shuttle tanker
               activities, may also physically impact prehistoric and/or historic archaeological resources. It is assumed that
               during pipeline emplacement, an array of eight 20,000-lb anchors is continuously repositioned.
                    Oil spills have the potential to impact both prehistoric and historic archaeological resources. Impacts to
               historic resources would be limited to visual impacts and, possibly, physical impacts associated with spill cleanup
               operations. Impacts to prehistoric archaeological sites would be the result of hydrocarbon contamination of
               organic materials, which have the potential to date site occupation through radiocarbon dating techniques, as
               well as possible physical disturbance associated with spill cleanup operations.
                    The OCS oil and gas activities will also generate tons of ferromagnetic structures and debris, which will
               tend to mask magnetic signatures of significant historic archaeological resources. The task of locating historic
               resources through an archaeological survey is, therefore, made more difficult as a result of leasing activity.

               (a) Historic

               Base Case Ana4uis

                    Since likely locations of archaeological sites cannot be delineated without first conducting a remote-sensing
               survey of the seabed and near-surface sediments, MMS, by virtue of the proposed Archaeological Resource
               Stipulation, would require an archaeological survey be conducted prior to development of lease tracts within
               the high probability zones for historic and prehistoric archaeological resources. Generally, in the western
               portion of the WPA, where unconsolidated sediments are thicker, it is likely that sidescan sonar win not detect
               shipwrecks buried beneath the mud. In this area (portions of Subarea W-1), the effectiveness of the survey
               for detecting historic shipwrecks of composite and wooden construction would depend on the capability of a
               magnetometer towed at a 50-m line spacing (as specified in NTL 91-02) to detect ferromagnetic masses of the
               size characteristically associated with shipwrecks.         Clausen and Arnold (1975) have concluded that
               magnetometer reliability for detecting ferrous objects at 150-m survey line spacing is Z5-30 percent It is
               assumed that an initial survey at a 50-m linespacing interval will be 90 percent effective at locating historic
               shipwrecks. The survey would therefore reduce the potential for an interaction by 90 percent.
                    According to Table IV-3, under the Base Case, 210 exploration, delineation, and development wells will
               be drilled, and 10 production platforms and 80 kin of pipelines will be installed in the Western Gulf. Of this
               number, 30 exploration, delineation, and development wells will be drilled, and 3 platforms and 24 km of










                  IV-438

                  pipelines will be installed within Subareas W-1 and W-2, where the majority of lease blocks with a high
                  probability for historic period shipwrecks are located. Under current survey requirements, as much as 10
                  percent of this activity would occur without accurate information about the proximity of ihe activity to an
                  historic resource. Ile recent MMS study (Garrison et al., 1989) has refined the high probability area (ARZ1)
                  for the occurrence of historic period shipwrecks. A Letter to Lessees was issued on November 30, 1990,
                  redefining the high probability area for historic shipwrecks. The location of any proposed activity within a lease
                  block that has a high probability for historic shipwrecks requires archaeological clearance prior to operations.
                  Considering that the expanded database contains 159 shipwrecks in the entire Western Gulf OCS, the
                  probability of an OCS activity contacting and damaging a shipwreck in the western part of the WPA is fairly
                  low. If an oil and gas structure contacted an historic resource, there could be the loss of significant or unique
                  information.
                       In the eastern part of the WPA, where shipwrecks are more likely to be detected by sidescan sonar due
                  to a thin Holocene sediment veneer overlying an indurated Pleistocene surface, the increasedsurvey linespacing
                  density (50 m) will reduce the potential for a direct physical contact between an impact-producing factor and
                  a shipwreck by an estimated 95 percent. The effectiveness of the survey would reduce the potential impacts
                  of OCS activities to historic shipwrecks in the eastern part of the WPA. There is a very small possibility that
                  an historic shipwreck could be impacted by OCS activities. Should such an impact occur, however, significant
                  or unique archaeological information could be lost.
                       Onshore historic properties include sites, structures, and objects such as historic buildings, forts, lighthouses,
                  homesteads, cemeteries, and battlefields. Sites already listed on the National Register of Historic Places and
                  those considered eligible for the Register have already been evaluated as being able to make a unique or
                  significant contribution to science. At present, unidentified historic sites may contain unique historic
                  information and would have to be assessed after discovery to determine the importance of the data.
                       Onshore development as a result of the proposed action could result in the direct physical contact between
                  the construction of new onshore facilities or pipeline canals and previously unidentified historic sites. This
                  direct physical contact with an historic site could cause physical -damage to, or complete destruction of,
                  information on the history of the region and the Nation. However, no new onshore pipelines or facilities are
                  projected in the Base Case for proposed Sale 143. There is, therefore, no expected impact to onshore historic
                  sites in the WPA from onshore development.
                       Maintenance dredging associated with the proposed action has the potential to impact a historic shipwreck.
                  Maintenance dredging in the Port Mansfield Entrance Channel is believed to impact the Santa Maria de Yciar,
                  which sank on April 29, 1554 (Espey, Huston & Associates, 1990). Table IV-6 indicates that, under the Base
                  Case less than 0.1 percent of the ship traffic through the Port Mansfield Cut is related to OCS use. Therefore,
                  the impact to the Santa Maria de Yciar directly attributable to OCS use as a result of the proposed action is
                  extremely low. As this shipwreck is a unique historic archaeological resource, the impact level of maintenance
                  dredging, in general, is considered to be very high. That portion of the impact attributable to OCS activities
                  resulting from the Base Case is extremely low. Table IV-6 lists eight major navigation channels in the WPA.
                  The percent of OCS usage of these channels in all cases is less than 0.1 percent
                       Should an off spill contact a coastal historic site, such as a fort or a lighthouse, the major impact would be
                  visual because of oil contamination of the site and its environment. According to Table IW 22 the probability
                  of a spill occurring and contacting within 10 days the coast of the WPA is I percent under the Base Case. This
                  impact is expected to be temporary and, reversible.
                       Since all platform locations within the high probability areas for the occurrence of historic and prehistoric
                  archaeological resources are given archaeological clearance prior to setting the structure, removal of the
                  structure should not result in any adverse impact to archaeological resources. This is consistent with the
                  findings of the Programmatic Environmental Assessment: Structure Removal Activities, Central and Western Gulf
                  of Merico Planning Areas (USDOI, MMS, 1987c).

                  Summary

                       The greatest potential impact to an historic archaeological resource as a result of the proposed action
                  would result from a contact between an OCS offshore activity (platform installation, drilling irig emplacement,










                                                                                                                           IV-439

               dredging, or pipeline project) and an historic shipwreck. A recently completed, MMS-funded study (Garrison
               et al., 1989) has resulted in the refinement of the high probability areas for the location of historic period
               shipwrecks.
                   A new NTL for archaeological resource surveys in the Gulf of Mexico Region (NTL 91-02) has increased
               the survey linespacing density for historic shipwreck surveys from 150 rn to 50 m.
                   Most other activities associated with the proposed action are expected to have very low impacts on historic
               archaeological resources. No new onshore infrastructure construction or pipeline landfalls are expected as a
               result of the proposed action. Historic cultural resources, therefore, will not be affected by these activities.
               The chance of contact from an off spill associated with the proposed action is very low. Furthermore, the
               impact from an off-spill contact on an historic coastal site, such as a fort or lighthouse, would be visual due to
               oil contamination. These impacts would be temporary and reversible. Impacts from dredging are expected
               to be low.
                   An OCS activity could contact a shipwreck because of incomplete knowledge on the location of shipwrecks
               in the Gulf. Although this occurrence is not probable, such an event would result in the disturbance or
               destruction of important historic archaeological information. Other factors associated with the proposed action
               are not expected to affect historic archaeological resources.

               Conclusion

                   There is a very small possibility of an impact between OCS oil and gas activities and a historic shipwreck
               or site. Should such an impact occur, unique or significant historic archaeological information could be lost.

               Effects of the Base Case Without the Proposed Stipulation

                   The greatest impact to an historic cultural resource as a result of the proposed action would result from
               a contact between an OCS offshore activity (platform installation, drilling rig emplacement, and pipeline
               projects) and an historic shipwreck. The Archaeological Resource Stipulation, which is considered part of the
               proposed action, requires remote-sensing surveys in areas designated to have a high probability for historic
               archaeological resources. It should also be noted that a proposed new regulation under 30 CFR 250.25 Will
               incorporate the stipulation into operational regulations. The OCS Lands Act, as amended, states that a permit
               for geological exploration shall be issued only if such exploration does not disturb any site, structure, or object
               of historical or archaeological interest As the only means to determine whether objects of historical or
               archaeological interest would be impacted by geological exploration, the archaeological surveys that are
               required under the current stipulation would still be necessary to comply with the OCS Lands Act, as amended.
               The effects of the impact-producing factors on historic archaeological resources without the Archaeological
               Resource Stipulation in place would, therefore, remain the same as those when the stipulation is considered
               part of the proposed action.
                   The archaeological surveys (under NTL 91-02) that are conducted prior to initiating oil and gas activities
               within a lease block are estimated to be 95 percent effective in locating historic shipwrecks in areas where
               sidescan sonar is effective in identifying shipwrecks. In areas where sidescan sonar is ineffective because of
               thick accumulations of sediment on the seafloor (these areas roughly account for 50% of the WPA),
               magnetometer data, which is estimated at being 90 percent effective at locating ferrous objects from historic
               shipwrecks at the 50-m linespacing required in NTL 91-02, will be the only means to detect shipwrecks. A
               recently completed, MMS-funded study (Garrison et al., 1989) has provided new data on shipwreck locations.
                   Most other activities associated with the proposed action are not expected to affect historic archaeological
               resources. No new onshore infrastructure construction or pipeline landfalls are expected as a result of the
               proposed action. Historic cultural resources, therefore, will not be affected by these activities. The chances
               of contact from an oil spill associated with the proposed action is very low. Furthermore, the impact from an
               off-spill contact on an historic coastal site, such as a fort or a lighthouse, would be visible due to oil
               contamination. These impacts would be temporary and reversible. Impacts from dredging directly attributed
               to the proposed action are considered to be low.










                  IV440

                      To summarize, because of incomplete knowledge on the location of shipwrecks in the Gulf, an OCS activity
                  could contact a shipwreck. Although this occurrence is not probable, such an event would result in the
                  disturbance or destruction of important historic archaeological information. Other factors associated with the
                  proposed action are not expected to affect historic archaeological resources.

                  High Case Analysis

                      I-ease blocks with a high probability for the occurrence of prehistoric, prehistoric and historic, or historic
                  archaeological resources may by found in the Western Gulf. Those blocks with a high probability for
                  prehistoric archaeological resources may be found landward of a line that roughly follows the 45-m bathymetric
                  contour. An LTL dated November 30, 1990, redefined the high probability areas for the presence of historic
                  period shipwrecks. An NTL (91-02), which changes survey methodology requirements forhistoric shipwreck
                  survey, shall become effective February 17, 1992. Section II.B.I.c.(2) presents a stipulation as a proposed
                  mitigating measure for leases resulting from the proposed action, the impact analysis for which, including the
                  potential archaeological resource stipulation, is presented below. It should also be noted that a proposed
                  rulemaking that creates an operational regulation to replace the Archaeological Stipulation has been issued.
                      Sections providing supportive material for the archaeological resources analysis include. Sections III.C.5.
                  (description of archaeological resources), IV.A.4. (offshore infrastructure), IV.A-5.a. (onshore infrastructure),
                  and IV.C.1. and 3. (oil spills).
                      A number of OCS-related factors may cause adverse impacts to archaeological resources. Damage caused
                  by the placement of drilling rigs, production platforms, pipelines, dredging, and anchoring could destroy artifacts
                  or disrupt the provenance and stratigraphic context of artifacts, sediments, and paleoindicators from which the
                  scientific value of the archaeological resource is derived. Oil spills could destroy the ability to date prehistoric
                  sites by radiocarbon dating techniques. Ferromagnetic: debris associated with OCS oil and gas activities would
                  tend to mask magnetic signatures of significant historic archaeological resources.
                      The placement of drilling rigs and production platforms has the physical potential to impact prehistoric
                  and/or historic archaeological resources. Pile driving associated with platform emplacement may also cause
                  sediment liquefaction an unknown distance from the piling. Pipeline placement has the physical potential to
                  impact prehistoric and/or historic archaeological resources. The anchoring associated with platform and
                  pipeline emplacement, as well as service vessel and shuttle tanker activities, may also physically impact
                  prehistoric and/or historic archaeological resources.
                      Maintenance dredging associated with the proposed action has the potential to irripact an historic
                  shipwreck. As a shipwreck may represent a unique historic archaeological resource, dredging may result in
                  damage or loss of significant or unique archaeological information; however, the frequency of impact related
                  to the proposed action is extremely low.
                      Oil spills have the potential to impact both prehistoric (by contamination of organic materials, which have
                  the potential to date site occupation through radiocarbon dating techniques) and historic archaeological
                  resources (limited to visual impacts and physical impacts associated with spill cleanup operations).
                      The OCS oil and gas activities will also generate tons of ferromagnetic structures and debris, which will
                  tend to mask magnetic signatures of significant historic archaeological resources.
                      According to Table IV-3, under the High Case, 690 exploration, delineation, and development wells will
                  be drilled, and 20 production platforms and 240 kin of pipelines will be installed in the Western Gulf. Of this
                  number, 100 exploration and production wells will be drilled, and 6 platforms and 48 kin of pipelines will be
                  installed within Subareas W-1 and W-2, where the majority of lease blocks with a high probability for historic
                  period shipwrecks are located. Under current survey requirements, as much as 10 percent of this activity would
                  occur without accurate information about the proximity of the activity to an historic resource. The recent MMS
                  study (Garrison et al., 1989) and LTL have redefined the high probability area for the occurrence of historic
                  period shipwrecks. The location of any proposed activity within a lease block that has a high probability for
                  historic shipwrecks requires archaeological clearance prior to operations. Considering that the expanded
                  database contains 159 shipwrecks in the entire Western Gulf OCS, the probability of an OCS activity contacting
                  and damaging a shipwreck is fairly low. If an oil and gas structure contacted an historic resource, there could










                                                                                                                                IV-441

                be damage to or loss of significant or unique historic archaeological information. The greater effectiveness of
                the survey would further reduce the potential impact to historic shipwrecks in the eastern part of the WPA.
                     Onshore historic properties include sites, structures, and objects such as historic buildings, forts, lighthouses,
                homesteads, cemeteries, and battlefields. Development as a result of the proposed action could result in the
                direct physical contact between the construction of new onshore facilities or pipeline canals and previously
                unidentified historic sites. No new offshore facilities are projected to be constructed under the High Case.
                Because no land is projected to be disturbed, impacts to coastal historic properties in the WPA are not
                expected to occur.
                     Should an off spill contact a coastal historic site, such as a fort or a lighthouse, the major impact would be
                visual because of off contamination of the site and its environment. This impact would most likely be
                temporary and reversible.
                     Since all platform locations within the high probability areas for the occurrence of historic and prehistoric
                archaeological resources are given archaeological clearance prior to setting the structure, removal of the
                structure should not result in any adverse impact to archaeological resources. This is consistent with the
                findings of the Programmatic Environmental Assessment: Structure Removal Activities, Central and Western Gulf
                of Mexico Planning Areas (USDOI, MMS, 1987c).

                Conclusion


                     There is a very small possibility of an impact between OCS oil and gas activities and an historic shipwreck
                or site. Should such an impact occur, unique or significant historic archaeological information could be lost

                (b) P@ehistoric

                     Offshore development as a result of the proposed action could result in an interaction between a drilling
                rig, a platform, a pipeline, dredging, or anchors and an inundated prehistoric site. This direct physical contact
                with a site could destroy fragile artifacts or site features and could disturb artifact provenance and site
                stratigraphy. The result would be the loss of archaeological data on prehistoric migrations, settlement patterns,
                subsistence strategies, and archaeological contacts for North America, Central America, South America, and
                the Caribbean.


                Base Case Ana4uis

                     The archaeological surveys, coupled with archaeological analysis and clearance of proposed location of
                operations, are estimated to be 90 percent effective in allowing identification and avoidance of high probability
                areas for site occurrence. According to Table IV-3, under the Base Case, 210 exploration, delineation, and
                development wells will be drilled, and 10 production platforms and 80 kin of pipelines will be installed in the
                Western Gulf. In-house analysis by MMS shows it is likely that some of these potential impacts will occur
                within Subarea W-3 which has no potential for the occurrence of prehistoric archaeological sites. Removing
                Subarea W-3 from the projected impacts resulting from the proposed action leaves 30 exploration, delineation,
                and development wells; 3 production platforms; and 24 km of pipelines installed (Table IV-3). The limited
                amount of impact to the seafloor throughout the WPA, coupled with the effectiveness of the survey and
                resulting archaeological clearance, is sufficient to assume a low potential for interaction between an impact-
                producing factor and a prehistoric archaeological site.
                     Onshore prehistoric archaeological resources include sites, structures, and objects such as shell middens,
                earth middens, campsites, kill sites, tool manufacturing areas, ceremonial complexes, and earthworks.
                Currently, unidentified onshore prehistoric sites would have to be assessed after discovery to determine the
                uniqueness or significance of the information that they contain. Sites already listed in the National Register
                of Historic Places and those considered eligible for the Register have already been evaluated as having the
                potential for making a unique or significant contribution to science. Of the unidentified coastal prehistoric sites
                that could be impacted by onshore development, some may contain unique information.










                  IV-442

                      Onshore development as a result of the proposed action could result in direct physical contact between
                  construction of new onshore facilities or a pipeline landfall and a previously unidentified prehistoric site. This
                  direct physical contact with a prehistoric site could destroy fragile artifacts or site features and could disturb
                  the site context. The result would be the loss of information on the prehistory of North America and the Gulf
                  Coast Region. No new onshore facilities or pipeline landfalls, however, are projected for the Base Case as a
                  result of proposed Sale 143 (Table IV-12). There should, therefore, be no impact to onshore WPA prehistoric
                  sites from onshore development
                      Should an oil spill contact a coastal prehistoric site, the potential for dating the site using C-14 could be
                  destroyed. This loss of information might be ameliorated by ceramic or lithic seriation or other relative dating
                  techniques. Previously unrecorded coastal sites could also experience an impact from. oil-spill cleanup
                  operations. Cleanup equipment could destroy fragile artifacts or site features and could disturb the site context
                  The result would be the loss of information on the prehistory of North America and the Gulf Coast Region.
                  Some of the coastal prehistoric sites that might be impacted by beach cleanup operations may contain unique
                  information. In coastal Texas, prehistoric sites occur frequently along the barrier islands and mainland coast
                  and the margins of bays and bayous. Thus, any spill that contacts the land would involve a potential impact
                  to a prehistoric site. The probability of a spill greater than or equal to 1,000 bbl occurringand contacting the
                  WPA coast within 10 days is I percent (Table IV-22). Based on this low probability, the assumption is that
                  no spills greater than or equal to 1,000 bbl will affect prehistoric archaeological resources.
                      Furthermore, it is assumed that a small spill of greater than 50 and less than 1,000 bbl win occur and
                  contact the coastline during the 35-year life of the proposed action. A few spills greater than 1 and less than
                  or equal to 50 bbl is assumed to contact the coast during the 35-year life of the proposed action. By the time
                  these spills contact the shore, however, there it is expected that not enough oil is available to cover an exposed
                  shell midden or other site to the extent that a large percentage of the organic remains in the site would be
                  contaminated.
                      All platform locations within the high probability areas for the occurrence of historic and prehistoric
                  archaeological resources are given archaeological clearance prior to setting the structure; removal of the
                  structure should not result in any adverse impact to archaeological resources. This is consistent with finding
                  of the Programmatic Environmental Assessment: Structural Removal Activities, Central anti Western Gulf of
                  Mexico Planning Areas (USDOI, MMS, 1987c).

                  Summary

                      Several impact-producing factors may threaten the prehistoric archaeological resources of the Western
                  Gulf. An impact could result from a contact between an OCS activity (pipeline and platform installations,
                  drilling rig emplacement and operation, dredging, and anchoring activities) and a prehistoric site located on
                  the continental shelf. The archaeological surveys and archaeological clearance of sites thatare required prior
                  to an operator beginning oil and gas activities in a lease block are estimated to be 90 percent effective at
                  identifying possible prehistoric sites. The survey and clearance provide a significant reduction in the potential
                  for a damaging interaction between an impact-producing factor and a prehistoric site. There is a very small
                  possibility of an OCS activity contacting a prehistoric site. Should such contact occur, there could be damage
                  to or loss of significant or unique archaeological information.
                      Onshore development as a result of the proposed action could result in the direct physical contact from
                  new facility construction, pipeline trenching, and navigation canal dredging. None of these activities is expected
                  to occur under the Base Case.
                      Should an oil spill contact a coastal prehistoric site, the potential for dating the site using radiocarbon
                  methods could be destroyed. Oil-spill cleanup operations could physically impact coastal prehistoric sites.
                  Previously unrecorded sites could also experience an impact from oil-spill cleanup operations on beaches. The
                  probability of a spill greater than or equal to 1,000 bbl occurring and contacting a coastal prehistoric site within
                  10 days is very low (1%) (Table IV-22), and it is assumed that no contact will occur. A few spills greater than
                  1 and less than or equal to 50 bbl are assumed to contact the coast, but these small spills would probably not
                  cover an exposed site, such as a shell midden, with enough oil to contaminate all the datable organic remains.
                  The impact level from oil-spill contact is assumed to be very low.











                                                                                                                           IV-443


                Conclusion

                     There is a very small possibility of an impact between OCS oil and gas activities and a prehistoric
                archaeological site. Should such an impact occur, there could be damage to or loss of significant or unique
                prehistoric archaeological information.

                Effects of the Base Case Without the Proposed Stipulation

                     Several impact-producing factors may threaten the prehistoric archaeological resources of the Western
                Gulf. An impact could result from a contact between an OCS activity (pipeline and platform installations,
                drilling rig emplacement and operation, and anchoring activities) and a prehistoric site located on the
                continental shelf. The Archaeological Resource Stipulation, which is considered part of the proposed action,
                requires remote-sensing surveys in areas designated to have a high probability for prehistoric archaeological
                resources. It should also be noted that a proposed new regulation under 30 CFR 250.25 win incorporate the
                stipulation into operational regulations. The OCS Lands Act, as amended, states that a permit for geological
                exploration shall be issued only if such exploration does not disturb any site, structure, or object of historical
                or archaeological interest As the only means to determine whether objects of historical or archaeological
                interest would be impacted by geological exploration, the archaeological surveys that are required under the
                current stipulation would still be necessary to comply with the OCS Lands Act, as amended. The effects of
                the impact-producing factors on prehistoric archaeological resources without the Archaeological Resource
                Stipulation in place would, therefore, remain the same as those when the stipulation is considered a part of
                the proposed action.
                     The archaeological surveys that are required prior to an operator beginning oil and gas activities in a lease
                block are estimated to be 90 percent effective in identifying possible prehistoric sites. The survey provides a
                significant reduction in the potential for a damaging interaction between an impact-producing factor and a
                prehistoric site.
                     Should such an impact occur, there could be damage to or loss of significant or unique prehistoric
                archaeological information.
                     Onshore development as a result of the proposed action could result in the direct physical contact between
                new facility construction, pipeline trenching, and navigation canal dredging. None of these activities are
                expected to occur under the Base Case.
                     Should an oil spill contact a coastal prehistoric site, the potential for dating the site using radiocarbon
                methods could be destroyed. Previously unrecorded sites could also experience an impact from oil-spin cleanup
                operations on beaches. The probability of a spill greater than or equal to 1,000 bbI contacting a coastal
                prehistoric site is very low, and it is assumed that no contact will occur. It is also assumed that no oil spills
                greater than 1 and less than or equal to 50 bbl win contact the coast.

                High Case Ana4uis

                     The higher level of offshore development projected for the High Case would increase the potential for an
                interaction between an impact-producing factor and a prehistoric site. Should an interaction occur, the
                potential exists for the loss of significant or unique archaeological information.
                     Offshore development as a result of the proposed action could result in an interaction between a drilling
                rig, a platform, a pipeline, dredging, or anchors and an inundated prehistoric site. This direct physical contact
                with a site could destroy fragile artifacts or site features and could disturb artifact provenance and site
                stratigraphy. The result would be the loss of archaeological data on prehistoric migrations, settlement patterns,
                subsistence strategies, and archaeological contacts for North America, Central America, South America, and
                the Caribbean.
                     Likely locations for archaeological sites can be delineated with high-resolution seismic data. As the high
                probability zone for the occurrence of prehistoric sites on the OCS approximates the 45-m bathymetric contour,
                Subarea W-3, which is deeper than 45 in in its entirety, is assumed to have no potential for the occurrence of
                these sites.










                  IV-444

                       The archaeological surveys, coupled with archaeological analysis and clearance of proposed location of
                  operations, are estimated to be 90 percent effective in allowing identification and avoidance of high probability
                  areas for site occurrence. According to Table IV-3, under the High Case, 690 exploration, delineation, and
                  development wells will be drilled, and 30 production platforms and 240 kin of pipelines will be installed in the
                  Western Gulf. Removing Subarea W-3 from the projected impacts resulting from the High Case leaves 100
                  exploration, delineation, and development wells; 6 production platforms; and 48 km of pipefines installed. The
                  limited amount of impact to the seafloor throughout the WPA, coupled with the effectiveness of the survey and
                  resulting archaeological clearance, is sufficient to assume a low potential for interaction between an impact-
                  producing factor and a prehistoric archaeological site.
                       No new onshore development is expected as a result of the High Case. Because no hand is projected to
                  be disturbed, impacts to coastal WPA prehistoric archaeological sites are not expected to occur.
                       Should an oil spill contact a coastal prehistoric site, the potential for dating the site using C-14 could be
                  destroyed.    Previously unrecorded coastal sites could also experience an impact from oil-spill cleanup
                  operations, which could destroy fragile artifacts or site features and disturb the site contexL The result would
                  be the loss of information on the prehistory of North America and the Gulf Coast Region. In coastal Texas,
                  prehistoric sites occur frequently along the barrier islands and mainland coast and the margins of bays and
                  bayous. Thus, any spill that contacts the land would involve a potential impact to a prehistoric site. The
                  probability of a spill greater than or equal to 1,000 bbl occurring and contacting the WPA coast within 10 days
                  is 1 percent (Table IV-22). Based on this low probability, the assumption is that no spills greater than or equal
                  to 1,000 bbl will affect prehistoric archaeological resources. Furthermore, it is estimated that a spill greater
                  than 50 and less than 1,000 bbl will occur and contact the coastline during the 35-year life of the proposed
                  action. It is also assumed that no OCS spills greater than I and less than or equal to 50 bbl Will contact the
                  coast during the 35-year life of the proposed action.
                       All platform locations within the high probability areas for the occurrence of historic and prehistoric
                  archaeological resources are given archaeological clearance prior to setting the structure; removal of the
                  structure should not result in any adverse impact to archaeological resources. This is consistent with finding
                  of the Programmatic Environmental Assessment: Structural Removal Activities, Central and Western Gulf of
                  Mexico Planning Areas (USDOI, MMS, 1987c).

                  Conclusion


                       There is a very small possibility of an impact between OCS oil and gas activities and a prehistoric
                  archaeological site. Should such an impact occur, there could be damage to or loss of significant or unique
                  prehistoric archaeological information.

                  (11) Impacts on Socioeconomic Conditions

                  (a) Populatiot4 Labor, and Employment

                       The importance of the off and gas industry to the coastal communities of the Gulf of Mexico is significant,
                  particularly in Louisiana and eastern Texas. Dramatic changes in the level of OCS oil and gas activity over
                  recent years have brought forth similar fluctuations in population, labor, and employment in the Gulf of Mexico
                  region. State government and citizen concern over the Gulf Coast's economic dependence on the oil and gas
                  industry has made clear the need for an analysis of the impact of the OCS program on the social and economic
                  well-being of affected communities.
                       This section focuses on an analysis of the direct, indirect, and induced impacts of the; OCS oil and gas
                  industry on the population, labor, and employment of counties and parishes in the Central and Western Gulf
                  coastal impact area caused by the proposed action in the Western Gulf. There would also be other economic
                  impacts, both direct and indirect, associated with the proposed actions because of their effect on other
                  industries, such as commercial fishing, tourism, and recreational fishing. The direct beneflit or loss in these
                  industries is addressed in the sections of this EIS related specifically to those topics. The OCS program's










                                                                                                                             IV-445

                 indirect and induced effect on these associated industries is much more difficult to quantify. Nevertheless, it
                 will generally constitute a fraction of the magnitude of the direct impact.
                     Section III.C.1. provides an historical perspective of the oil and gas industry, as well as a brief description
                 of recent events that have significantly affected the level of OCS activity in the Gulf of Mexico. A detailed
                 discussion of historical trends in population, labor, and employment within the coastal impact area of the
                 Central and Western Gulf can be found in Section III.C.2. Included also in that section is a listing of counties
                 and parishes in the Central and Western Gulf coastal impact area, as well as current statistics and future
                 projections of population, labor, and employment levels for coastal subareas in the region. These projections
                 will serve as a baseline against which impacts will be measured.
                     The methodology developed to quantify these impacts on population, labor, and employment takes into
                 account changes in OCS-related employment, along with population and labor impacts resulting from these
                 employment changes within each individual coastal subarea. For analysis purposes, the projections of OCS-
                 related employment are classified into three categories: direct, indirect, and induced employment.
                     Direct employment associated with the oil and gas industry consists of those workers involved in oil and
                 gas exploration, development, and production operations, including geophysical and seismograph surveys,
                 exploratory drilling, well operation, maintenance, and other contract support services. These activities are
                 covered under the Standard Industrial Classification (SIC) Code 13--Off and Gas Extraction. To facilitate the
                 analysis, several assumptions were made regarding the employment associated with SIC 13 activity projected
                 to result from the proposed action. These assumptions are estimates of typical levels of activity and
                 employment based on historical observations:

                         Exploration Activity -     One rig can drill an average of nine per wells per year with
                                                    approximately 133 workers.

                         Development Activity -     One platform rig can drill an average of six wells per year with a
                                                    crew of approximately 115 workers.

                         Production Activity -      One offshore platform can operate with an average crew of 28
                                                    workers.

                     A population and employment computer model developed at MMS uses these and other assumptions to
                 translate estimates of exploration, development, and production activities associated with the proposed action
                 into annual projections of direct employment for each planning area. Planning area level employment
                 projections are apportioned to offshore subareas on the basis of each offshore subarea's hydrocarbon resource
                 potential and projected share of the offshore infrastructure. Employment within each offshore subarea is then
                 allocated to coastal subareas on the basis of an allocation matrix developed at MMS. This matrix allocates
                 direct employment offshore to those coastal subareas where the onshore support facilities for that particular
                 offshore site are expected to be located. The matrix was derived from an analysis of the historical and
                 proposed location of onshore support facilities for the different actual or planned drilling sites offshore. The
                 allocation matrix also accounts for the fact that employment impacts from offshore activity are not constrained
                 by planning area or subarea boundaries. In other words, oil and gas development in the CPA can and does
                 impact the coastal communities of the Western Gulf and vice versa.
                     Indirect employment resulting from activities in the primary oil and gas extraction industry occurs in
                 secondary or supporting off- and gas-related industries. Section III.C.2. provides a listing of those industries
                 considered in the projection of indirect employment. Employment in the Sanitary Service Industry, which
                 supports oil-spill clean-up activities (SIC 4959), was not included as part of indirect employment in the model
                 because the manpower requirements for oil-spill clean-up activities are highly unpredictable. The level of
                 employment involved in any given clean-up effort is influenced by a variety of factors, such as whether or not
                 the oil comes ashore, the coastal formation, weather conditions at the time of the incident, type and quantity
                 of off spilled, as well as the extent and duration of the oiling. Nevertheless, employment in off-spill clean-up
                 activities has been included in the Base Case analysis as an external adjustment to the population and










                IV446

                employment model, using assumptions regarding the size of potential oil spills presented in Section IV.C.1 and
                IV.C.3.
                     Based on an analysis of actual industry-specific employment levels in the counties of the coastal impact
                area, a multiplier was determined to estimate indirect employment from direct employment projections for the
                oil and gas extraction industry. The indirect employment multiplier determined for this analysis was 0.67.
                     Induced employment in tertiary industries is generated from both direct and indirect employment and
                includes jobs that are created or supported by the expenditures of employees in primary and secondary
                industries. Induced employment results from the demand for consumer goods and services such as food,
                clothing, housing, and entertainment. Based on a previous MMS analysis of employment impacts, the induced
                employment multiplier for this analysis was estimated to be 0.33.
                     The total employment impact to each coastal subarea because of the proposed action is the sum of its
                direct, indirect, and induced employment impact projections. The population dependent on the income from
                oil- and gas-related employment for their subsistence was derived from total employment estimates based on
                an analysis of the historic ratio of population to employment in the coastal subareas. Labor impacts were
                addressed using both population and employment data to assess the supply and demand for workers trained
                in oil- and gas-related trades.
                     To arrive at a bottom-line level of impact for population, labor, and employment, the population and
                employment model is used to convert the projections to a format that facilitates analysis and comparison. This
                conversion involves the estimation of annual changes in population, labor, and employment projections for the
                proposed action as a percent of the population, labor, and employment levels expected in absence of the
                proposal for each coastal subarea. The projections of population and employment described in Section III.C.2.
                were used as a baseline for the analysis. These baseline projections assume the continuation of existing social,
                economic, and technological trends; therefore, they also include population and employment resulting from the
                continuation of current patterns in OCS leasing activity. To derive population and employment levels in
                absence of the proposal, the population and employment impacts estimated for the proposed action were
                subtracted from the baseline projections which, inherently, include impacts from the proposal.

                Base Case Ana4uis

                     Baseline employment projections for the coastal impact area of the Central and Western Gulf can be found
                in Figure IV-10. Displayed also on this figure are baseline employment projections excluding jobs generated
                by the proposed action in the Western Gulf. The methodology discussion preceding this Base Case analysis
                provides a description of these projections. A total of approximately 24,000 person-years of employment
                (direct indirect, and induced) are required in the Central and Western Gulf coastal subareas in support of the
                proposed sale in the Western Gulf throughout its 35-year life. Over 72 percent of the total employment
                generated by the proposed action in the Western Gulf is expected to be supported by the coastal communities
                of the CPA. Peak-year impacts occur in 1997 and 1998, with a total of approximately 1,500workers involved
                in primary, secondary, and tertiary industries. Exploratory activities, which occur during the first 11 years of
                the life of the proposed action, are the main contributor to peak-year direct and total employment impacts.
                After this initial peak in 1997 and 1998, total employment impacts begin to decline as oil and gas exploration
                is reduced in areas leased under the proposed action. Employment impacts resulting from development
                activities remain fairly steady from 1995 through 2016. A second, smaller total employment peak impact is
                experienced during the years 2009 through 2015, when employment resulting from production activities offshore
                reaches its peak. Oil and gas production operations are the greatest contributor to overall employment
                impacts, accounting for approximately 50 percent of total direct employment impacts caused by activities in the
                Western Gulf. Direct employment in the primary oil and gas extraction industry (SIC 13) accounts for 45
                percent of the total employment impact projected for the coastal subareas of the Central arid Western Gulf.
                Indirect and induced employment impacts in secondary and tertiary industries amount to approximately 30
                percent and 25 percent, respectively, of the total employment impacts over the life of the proposed action in
                the Western Gulf.
                     Table IV-33 displays the model projections of total OCS-related employment impacts (direct, indirect, and
                induced) from Sale 143 in the Western Gulf to the coastal subareas of the CPA and WPA throughout the life










                                                                                                                           IV-447


                                                       A. Western Planning Area
                             5,000,000
                                                           Baseline Projedon       Mhout Proposal


                             4,500,000




                             4,000,000



                           (D
                           1 3,500,000
                           E
                           LU

                             3,000,000




                             2,500,000
                                                                         &                              10@1 10

                                                                         Year
                                                       B.    Central Planning Area
                             2,600,000
                                                           Baseline Projection      Without proposal
                                                                                        ----------


                             2,400,000
                           U)


                           0 2,200,000


                           (D
                           1 2,000,000
                           E
                           LU
                             11800,000




                             1,600,000



                                                                           Year



                       Due to the very low Impact olf the proposed action on employment, the projections graphed on the figure may appear to overlap.


                Figure IV-10. Base Case Employment Impacts from Western Gulf Sale 143 (USDOI,
                                    MMS, Gulf of Mexico OCS Region estimates, 1991).










                  Iv4a














                                                                       Table IV-33

                                       Base Case OCS-Related Employment Projections (Direct+Indirect+Induced)
                                                                  western Gulf Sale 143
                                                                     (person-years)


                  YEAR              Wl           W2           Ci           C2           C3           C4           WGC,K*      CGOM**


                  1993                     0            0            0            0            0            0            0            0
                  1994                     3          34           31           96             0            0          38           126
                  1995                   21          165          145          436             0            0          186          582
                  1996                   21          165          145          436             0            0          186          582
                  1997                   39          317          281          849             0            0          356        1130
                  1998                   39          317          281          849             0            0          356        1130
                  1999                   40          298          263          784             0            0          338        1046
                  2000                   44          314          275          814             0            0          357        1089
                  2001                   41          242          207          589             0            0          283          796
                  2002                   41          242          207          589             0            0          283          796
                  2003                   42          223          188          523             0            0          265          712
                  2004                   38          189          158          428             0            0          227          585
                  2005                   43          185          151          393             0            0          228          545
                  2006                   43          185          151          393             0            0          228          545
                  2007                   43          185          151          393             0            0          228          545
                  2008                   43          185          151          393             0            0          228          545
                  2009                   47          201          164          424             0            0          247          587
                  2010                   47          201          164          424             0            0          247          587
                  2011                   47          201          164          424             0            0          247          587
                  2012                   47          201          164          424             0            0          247          587
                  2013                   47          201          164          424             0            0          247          587
                  2014                   47          201          164          424             0            0          247          587
                  2015                   47          201          164          424             0            0          247          587
                  2016                   43          185          151          393             0            0          228          545
                  2017                   36          139          ill          274             0            0          175          385
                  2018                   32          123           99          244             0            0          155          342
                  2019                   28          108           86          213             0            0          136          300
                  2020                   24           93           74          183             0            0          116          257
                  2021                   20           77           62          152             0            0          97           214
                  2022                   16           62           49          122             0            0          78           171
                  2023                   12           46           37           91             0            0          58           128
                  2024                     a          31           25           61             0            0          39           86
                  2025                     4          15           12           30             0            0          19           43
                  2026                     4          15           12           30             0            0          19           43
                  2027                     0            0            0            0            0            0            0            0


                                       1094         5544          4649       12727             0            0         6638        17376



                     Western Gulf of Mexico.
                     Central Gulf of Mexico.

                  Source: USDOI, MMS, Gulf of Mexico OCS Region estimates, 1991.










                                                                                                                              IV-449

                of the proposed action. Table IV-34 provides estimates of annual impacts to the population and employment
                of each coastal subarea as a percent of levels expected in absence of the proposal. These impact estimates
                represent changes in the new share of the existing population and employment that will be dependent on the
                OCS oil and gas industry for support as a result of the proposed action. These impact estimates alone do not
                provide enough information to determine whether employment needs will be met with the population and labor
                force in the area or with immigrants and new labor force from other areas. However, this issue will be
                addressed later in the Base Case analysis.
                     The greatest impact to employment is expected in coastal Subareas C-1 and C-2, with peak-year impact
                estimates for 1997 and 1998 of 0.11 and 0.17 percent, respectively. The coastal communities of the CPA are
                expected to support over 72 percent of the total employment generated by the Western Gulf sale. Coastal
                Subareas W-1 and W-2 both have relatively small peak employment impacts of 0.01 percent. The WPA
                contributes the remaining 28 percent of the total employment required in support of the proposed action in
                the Western Gulf.
                     Employment impacts resulting from oil-spill clean-up activities, because of their highly unpredictable nature,
                were handled apart from the population and employment model. The level of employment associated with
                any given clean-up operation is dependent on numerous variables which, in themselves, are also difficult to
                predict. Nevertheless, the most labor-intensive clean-up operations are those from spills that contact the
                coastline, particularly recreational beaches. For the purpose of this analysis, it is assumed that only those spills
                contacting land will involve significant manpower requirements in their clean-up efforts. Based on employment
                statistics from recent spill clean-up operations along the coast, the assumption is that for every kilometer of
                coastline subjected to heavy oiling, approximately 100 temporary workers will be employed for a maximum of
                6 weeks.
                     Section IV.C.1. presents estimates of the mean number of offshore spills assumed to result from the
                proposed action in the WPA. The probability that one or more spills greater than or equal to 1,000 bbl will
                occur and contact land within 10 days of the accident is 1 percent (Table IV-22). Based on the low probability
                of a spill of this size occurring and contacting land within 10 days, the assumption is that no significant
                employment requirements will result from the clean-up of offshore spills of this size category in the Base Case.
                No spills of the size category greater than 50 bbl and less than 1,000 bbl are assumed to occur or contact the
                coastline of the Western Gulf (Table IV-3). Eight spills of the size category greater than 1 bbl and or equal
                to 50 bbl are estimated to occur in the WPA over the life of the proposed action. However, none is assumed
                to contact the coastline of the Western Gulf (Section IV.C.I.). Furthermore, employment impacts resulting
                from the clean-up of spills this small are assumed to be negligible.
                     In addition to the offshore spills referenced above, a number of small onshore spills are expected to occur
                (Table IV-5). The level of clean-up action associated with spills of this size will be minimal.
                     The greatest impact on population from activities associated with Sale 143 is expected in coastal Subareas
                C-1 and C-2 with peak year impact estimates for 1997 and 1998 of 0.11 and 0.17 percent, respectively (Table
                IV-34). The coastal communities of the Western Gulf have relatively small peak population impacts of 0.01
                percent
                     The level of OCS-related employment expected to result from the proposed action in the Western Gulf
                is not significant enough to attract new residents and labor force to the area. Analysis of historical trends has
                shown that only population impacts greater than 1 percent typically involve positive net migration to any given
                area. None of the coastal subareas is projected to experience population impacts greater than 1 percent
                because of the proposed action. Ubor force impacts will parallel population and employment impacts. Jobs
                are expected to be filled by currently unemployed or underemployed workers or by future entrants into the
                labor force already living in the area. Therefore, employment demands in support of the proposed action will
                be met with the existing population and available labor force.

                Summary

                     Peak annual changes in the population, labor, and employment of all coastal subareas in the Central and
                Western Gulf resulting from the proposed action in the Western Gulf represent less than I percent of the levels
                expected in absence of the proposal. The coastal communities of the CPA are expected to support over 72









                  IV-450













                                                                         Table IV-34

                                          Population and Employment Impact Levels for the Base Case Scenario
                                                                   Western Gulf Sale 143
                                                                          (percent-)



                  EMPLOYMENT IMPACT LEVELS:                                         POPULATION IMPACT LEVELS:

                  YEAR      W1       W2       Cl       C2       C3       C4         YEAR    W1       W2       Cl       C2        C3     C4


                  1993     0.00%    0.00%     0.00%   0.00%    0.00%    0.00%       1993    0.00%   0.00%   0.00%    0.00%   0.00%    0.00%
                  1994     0.00%    0.00%     0.01%   0.02%    0.00%    0.00%       1994    0.00%   0.00%   0.01%    0.02%   0.00%    0.00%
                  199S     0.011    0.01%     0.06%   0.09%    0.00%    0.00%       1995    0.01%   0.01%   0.06%    0.09%   0.00%    0.00%
                  1996     0.01%    0.01%     0.06%   0.09%    0.00%    0.00%       1996    0.01%   0.01%   0.06%    0.09%   0.00%    0.00%
                  1997     0.01%    0.01%     0.11%   0.17%    0.00%    0.00%       1997    0.01%   0.01%   0.11%    0.17%   0.00%    0.00%
                  1998     0.01%    0.01%     0.11%   0.171    0.00%    0.00%       1998    0.01%   0.01%   0.11%    0.17%   0.00%    0.00%
                  1999     0.011    0.01%     0.10%   O.lS%    0.00%    0.00%       1999    0.01%   0.01%   0.10%    0.161   0.00%    0.00%
                  2000     0.01%    0.01%     0.10%   O.lS%    0.00%    0.00%       2000    0.01%   0.01%   0.11%    0.16%   0.00%    0.00%
                  2001     0.01%    0.01%     0.07%   0.11%    0.00%    0.00%       2001    0.01%   0.01%   0.08%    0.12%   0.00%    0.00%
                  2002     0.01%    0.01%     0.07%   o.il%    0.00%    0.00%       2002    0.01%   0.01%   0.08%    0.12%   0.00%    0.00%
                  2003     0.01%    0.01%     0.07%   0.10%    0.00%    0.00%       2003    0.01%   0.01%   0.07%    0.10%   0.00%    0.00%
                  2004     0.01%    0.01%     0.06%   0.08%    0.00%    0.00%       2004    0.01%   0.01%   0.06%    0.08%   0.00%    0.00%
                  2005     0.01%    0.01%     0.05%   0.07%    0.00%    0.00%       2005    0.01%   0.01%   0.06%    0.08%   0.00%    0.00%
                  2006     0.01%    0.011     0.05%   0.07%    0.00%    0.00%       2006    0.01%   0.01%   0.06%    0.07%   0.00%    0.00%
                  2007     0.01%    0.01%     0.05%   0.07%    0.00%    0.00%       2007    0.01%   0.01%   0.06%    0.07%   0.00%    0.00%
                  2008     0.01%    0.01%     0.05%   0.07%    0.00%    0.00%       2008    0.01%   0.01%   0.061    0.07%   0.00%    0.00%
                  2009     0.01%    0.01%     0.05%   0.07%    0.00%    0.00%       2009    0.01%   0.01%   0.06%    0.08%   0.00%    0.00%
                  2010     0.01%    0.01%     0.05%   0.07%    0.00%    0.00%       2010    0.01%   0.011   0.06%    0.08%   0.00%    0.00%
                  2011     0.01%    0.01%     0.051   0.07%    0.00%    0.00%       2011    0.01%   0.01%   0.06%    0.08%   0.00%    0.00%
                  2012     0.01%    0.01%     0.05%   0.07%    0.00%    0.00%       2012    0.01%   0.01%   0.06%    0.08%   0.00%    0.00%
                  2013     0.01%    0.01%     0.05%   0.07%    0.00%    0.00%       2013    0.01%   0.01%   0.06%    0.08%   0.00%    0.00%
                  2014     0.01%    0.011     0.05%   0.07%    0.00%    0.00%       2014    0.01%   0.01%   0.06%    0.08%   0.00%    0.00%
                  2015     0.01%    0.01%     0.05%   0.07%    0.00%    0.00%       2015    0.01%   0.01%   0.06%    0.08%   0.00%    0.00%
                  2016     0.01%    0.01%     0.05%   0.06%    0.00%    0.00%       2016    0.01%   0.01%   0.05%    0.07%   0.00%    0.00%
                  2017     0.01%    0.000     0.03%   0.04%    0.00%    0.00%       2017    0.01%   0.00%   0.04%    0.05%   0.00%    0.00%
                  2018     0.01%    0.00%     0.03%   0.04%    0.00%    0.00%       2018    0.01%   0.00%   0.03%    0.04%   0.00%    0.00%
                  2019     0.01%    0.00%     0.03%   0.03%    0.00%    0.00%       2019    0.01%   0.00%   0.03%    0.04%   0.00%    0.00%
                  2020     0.00%    0.00%     0.02%   0.03%    0.00%    0.00%       2020    0.01%   0.00%   0.03%    0.03%   0.00%    0.00%
                  2021     0.00%    0.00%     0.02%   0.02%    0.00%    0.00%       2021    0.00%   0.00%   0.02%    0.03%   0.00%    0.00%
                  2022     0.00%    0.00%     0.01%   0.02%    0.00%    0.00%       2022    0.00%   0.00%   0.02%    0.02%   0.00%    0.00%
                  2023     0.00%    0.00%     0.01%   0.01%    0.00%    0.00%       2023    0.00%   0.00%   0.01%    0.02%   0.00%    0.00%
                  2024     0.00%    0.00%     0.01%   0.01%    0.00%    0.00%       2024    0.00%   0.00%   0.01%    0.01%   0.00%    0.00%
                  2025     0.00%    0.00%     0.00%   0.00%    0.00%    0.00%       2025    0.00%   0.00%   0.00%    0.01%   0.00%    0.00%
                  2026     0.00%    0.00%     0.00%   0.00%    0.00%    0.00%       2026    0.00%   0.00%   0.00%    0.00%   0.00%    0.00%
                  2027     0.00%    0.00%     0.00%   0.00%    0.00%    0.00%       2027    0.00%   0.00%   0.00%    0.00%   0.00%    0.00%




                    Note:  Impact levels represent the percent change in population or employment due to the proposal with respect
                           to total levels expected in absence of the proposal.

                  Sourcet USDor, KMS, Gulf of Mexico OCS Region estimates, 1991.










                                                                                                                             IV-451

                percent of the total employment generated by the Western Gulf sale. The WPA contributes the remaining 28
                percent of total employment impacts. Employment resulting from oil-spill clean-up activities due to the
                proposed action is negligible. It is expected that employment demands in support of the proposed action will
                be met with the existing population and available labor force in the region.

                Conclusion

                     The Base Case impact of the proposed action in the Western Gulf on the population, labor, and
                employment of the counties and parishes of the Central and Western Gulf coastal impact area is expected to
                be less than 1 percent of the levels expected in the absence of the proposal.

                High Case Ana4uis
                     Population, labor, and employment impacts resulting from the Western Gulf proposed action in the High
                Case are approximately two-and-a-half times as high as those expected in the Base Case. A total of
                approximately 62,600 person-years of employment (direct, indirect, and induced) are required in the Central
                and Western Gulf coastal subareas in support of the proposed action for the High Case. Over 75 percent of
                the total employment generated by the proposed action in the Western Gulf is expected to be supported by
                the coastal communities of the CPA- Peak-year impacts occur in 1998, with approximately 3,400 workers
                involved in primary, secondary, and tertiary industries. Direct employment in the primary oil and gas extraction
                industry (SIC 13) accounts for 45 percent of the total employment impact projected for the coastal subareas
                of the Central and Western Gulf over the life of the proposed action. Exploratory activities, which occur
                during the first 12 years of the life of the proposed action, are the main contributor to peak-year direct and
                total employment impacts. After their initial peak in 1998, total employment impacts begin to decline as oil
                and gas exploration is reduced in areas leased under the proposed action. Peak employment impacts resulting
                from development activities take place soon after exploratory activities reach their peak, but are much less
                intense. Even though exploratory activities drive peak-year employment impacts, the greatest contributor to
                overall employment impacts for the High Case is production operations. Employment in oil and gas production
                activities accounts for approximately 56 percent of total direct employment impacts resulting from production
                in the Western Gulf. Indirect and induced employment impacts in secondary and tertiary industries amount
                to approximately 30 and 25 percent, respectively, of the total employment impacts over the life of the proposed
                action in the Western Gulf.
                     Table IV-35 displays the model projections of total OCS-related employment impacts (direct, indirect, and
                induced) from Sale 143 in the Western Gulf to the coastal subareas of the CPA and WPA throughout the life
                of the proposed action in the High Case. Table IV-36 provides estimates of peak annual impacts to the
                population and employment of each coastal subarea as a percent of levels expected in absence of the proposal.
                These impact estimates represent changes in the new share of the existing population and employment that
                will be dependent on the OCS oil and gas industry for support as a result of the proposed action. These
                impact estimates alone do not provide enough information to determine whether employment needs will be
                met with the existing population and labor force in the area or with immigrants and new labor force from other
                areas.
                     The greatest impact to employment is expected in coastal Subareas C-I and C-2, with peak-year impact
                estimates for 1998 of 0.24 percent and 0.39 percent, respectively. The coastal communities of the CPA are
                expected to support over 75 percent of the total employment generated by the Western Gulf sale. Coastal
                Subareas W-1 and W-2 have small peak employment impacts of 0.02 and 0.03 percent, respectively. The WPA
                contributes the remaining 25 percent of the total employment required in support of the proposed action in
                the Western Gulf.
                     Employment impacts resulting from oil-spill clean-up activities, because of their highly unpredictable nature,
                were handled apart from the population and employment model. The level of employment associated with
                any given clean-up operation is dependent on numerous variables which, in themselves, are also difficult to
                predict. Nevertheless, the most labor-intensive clean-up operations are those from spills that contact the
                coastline, particularly recreational beaches. For the purpose of this analysis, it is assumed that only those spills










                   IV-452













                                                                          Table IV-35


                                         High Case OCS-Related Employment Projections (Direct+Indirect+Induced)
                                                                    Western Gulf Sale 143
                                                                        (person-years)


                   YEAR               Wl           W2            Cl            C2           C3           C4           WG4)M-      CGOM**


                   1993                      0            0            0             0            0             0            0            0
                   1994                      7          68           62           191             0             0          75          253
                   1995                    32          292          261           799             0             0         323         1061
                   1996                    32          292          261           799             0             0         323         1061
                   1997                    58          539          483          1476             0             0         597         1959
                   1998                    77          720          646          1981             0             0         798         2627
                   1999                    69          625          559          1701             0             0         694         2261
                   2000                    80          712          635          1927             0             0         792         2562
                   2001                    70          590          523          1560             0             0         660         2082
                   2002                    76          634          562          1683             0             0         710         2245
                   2003                    69          563          498          1471             0             0         632         1969
                   2004                    62          495          436          1280             0             0         557         1716
                   2005                    66          510          447          1295             0             0         576         1742
                   2006                    66          510          447          1295             0             0         576         1742
                   2007                    66          510          447          1295             0             0         576         1742
                   2008                    66          510          447          1295             0             0         576         1742
                   2009                    66          507          444          1275             0             0         573         1718
                   2010                    66          507          444          1275             0             0         573         1718
                   2011                    66          507          444          1275             0             0         573         1718
                   2012                    66          507          444          1275             0             0         573         1718
                   2013                    66          507          444          1275             0             0         573         1718
                   2014                    66          507          444          1275             0             0         573         1718
                   2015                    66          507          444          1275             0             0         573         1718
                   2016                    62          479          419          1206             0             0         542         1625
                   2017                    55          421          368          1049             0             0         476         1416
                   2018                    49          379          331           946             0             0         428         1277
                   2019                    44          337          295           843             0             0         381         1138
                   2020                    33          251          219           617             0             0         284          836
                   2021                    27          209          182           514             0             0         236          697
                   2022                    22          167          146           411             0             0         189          557
                   2023                    16          125          109           309             0             0         142          418
                   2024                    11           84           73           206             0             0          95          279
                   2025                      5          42           36           103             0             0          47          139
                   2026                      4          28           24            69             0             0          32            93
                   2027                      0            0            0             0            0             0            0            0


                                         1690        13639         12023        35242             0             0       1,5329        47265



                      Western Gulf of Mexico.
                      Central Gulf of Mexico.

                   Source: USDOI, MKS, Gulf of Mexico OCS Region estimates, 1991.











                                                                                                                           IV453













                                                                   Table IV-36

                                    Population and Employment impact Levels for the High Case Scenario
                                                              Western Gulf Sale 143
                                                                     (percent*)



                EMPLOYMENT IMPACT LEVELSs                                     POPULATION IMPACT LEVELS:

                YEAR      W1       W2       Cl       C2       C3       C4     YEAR    W1       W2       Cl       C2       C3      C4


                1993     0.00%    0.00%     0.00%   0.00%    0.00%    0.00%   1993    0.00%  0.00%   0.00%   0.00%   0.00%   0.00%
                1994     0.00%    0.00%     0.02%   0.04%    0.00%    0.00%   1994    0.00%  0.00%   0.02%   0.04%   0.00%   0.00%
                1995     0.01%    0.01%     0.10%   0.16%    0.00%    0.00%   1995    0.01%  0.01%   0.10%   0.17%   0.00%   0.00%
                1996     0.01%    0.01%     0.10%   0.16%    0.00%    0.00%   1996    0.01%  0.01%   0.10%   0.16%   0.00%   0.00%
                1997     0.02%    0.02%     0.18%   0.29%    0.00%    0.00%   1997    0.02%  0.02%   0.19%   0.30%   0.00%   0.00%
                1998     0.02%    0.03%     0.24%   0.39%    0.00%    0.00%   1998    0.02%  0.03%   0.25%   0.40%   0.00%   0.00%
                1999     0.02%    0.02%     0.21%   0.33%    0.00%    0.00%   1999    0.02%  0.02%   0.22%   0.34%   0.00%   0.00%
                2000     0.02%    0.03%     0.23%   0.37%    0.00%    0.00%   2000    0.02%  0.03%   0.25%   0.38%   0.00%   0.00%
                2001     0.02%    0.02%     0.19%   0.29%    0.00%    0.00%   2001    0.02%  0.02%   0.20%   0.31%   0.00%   0.00%
                2002     0.02%    0.02%     0.20%   0.31%    0.00%    0.00%   2002    0.02%  0.02%   0.22%   0.33%   0.00%   0.00%
                2003     0.02%    0.02%     0.18%   0.27%    0.00%    0.00%   2003    0.02%  0.02%   0.19%   0.29%   0.00%   0.00%
                2004     0.02%    0.02%     0.15%   0.23%    0.00%    0.00%   2004    0.02%  0.02%   0.17%   0.25%   0.00%   0.00%
                2005     0.02%    0.02%     0.16%   0.23%    0.00%    0.00%   2005    0.02%  0.02%   0.17%   0.25%   0.00%   0.00%
                2006     0.02%    0.02%     0.15%   0.23%    0.00%    0.00%   2006    0.02%  0.02%   0.17%   0.25%   0.00%   0.00%
                2007     0.02%    0.02%     0.15%   0.23%    0.00%    0.00%   2007    0.02%  0.02%   0.17%   0.24%   0.00%   0.00%
                2008     0.02%    0.02%     0.15%   0.23%    0.00%    0.00%   2008    0.02%  0.02%   0.17%   0.24%   0.00%   0.00%
                2009     0.02%    0.02%     0.15%   0.22%    0.00%    0.00%   2009    0.02%  0.02%   0.16%   0.24%   0.00%   0.00%
                2010     0.02%    0.02%     0.15%   0.22%    0.00%    0.00%   2010    0.02%  0.02%   0.16%   0.24%   0.00%   0.00%
                2011     0.02%    0.02%     0.15%   0.22%    0.00%    0.00%   2011    0.02%  0.02%   0.16%   0.23%   0.00%   0.00%
                2012     0.01%    0.02%     0.14%   0.21%    0.00%    0.00%   2012    0.02%  0.02%   0.16%   0.231   0.00%   0.00%
                2013     0.01%    0.01%     0.24%   0.21%    0.00%    0.00%   2013    0.02%  0.02%   0.16%   0.23%   0.00%   0.00%
                2014     0.01%    0.01%     0.14%   0.21%    0.00%    0.00%   2014    0.02%  0.02%   0.16%   0.23%   0.00%   0.00%
                2015     0.01%    0.01%     0.14%   0.21%    0.00%    0.00%   2015    0.02%  0.02%   0.16%   0.23%   0.00%   0.00%
                2016     0.01%    0.01%     0.13%   0.20%    0.00%    0.00%   2016    0.02%  0.02%   0.15%   0.21%   0.00%   0.00%
                2017     0.02%    0.01%     0.11%   0.17%    0.00%    0.00%   2017    0.01%  0.01%   0.13%   0.18%   0.00%   0.00%
                2018     0.01%    0.01%     0.10%   0.15%    0.00%    0.00%   2018    0.01%  0.01%   0.12%   0.16%   0.00%   0.00%
                2019     0.01%    0.01%     0.09%   0.13%    0.00%    0.00%   2019    0.01%  0.01%   0.10%   0.15%   0.00%   0.00%
                2020     0.01%    0.01%     0.07%   0.10%    0.00%    0.00%   2020    0.01%  0.01%   0.08%   0.11%   0.00%   0.00%
                2021     0.01%    0.01%     0.05%   0.08%    0.00%    0.00%   2021    0.01%  0.01%   0.06%   0.09%   0.00%   0.00%
                2022     0.00%    0.00%     0.04%   0.06%    0.00%    0.00%   2022    0.01%  0.00%   0.05%   0.07%   0.00%   0.00%
                2023     0.00%    0.00%     0.03%   0.05%    0.00%    0.00%   2023    0.00%  0.00%   0.04%   0.05%   0.00%   0.00%
                2024     0.00%    0.00%     0.02%   0.03%    0.00%    0.00%   2024    0.00%  0.00%   0.02%   0.03%   0.00%   0.00%
                2025     0.00%    0.00%     0.01%   0.02%    0.00%    0.00%   2025    0.00%  0.00%   0.01%   0.02%   0.00%   0.00%
                2026     0.00%    0.00%     0.01%   0.01%    0.00%    0.00%   2026    0.00%  0.00%   0.01%   0.01%   0.00%   0.00%
                2027     0.00%    0.00%     0.00%   0.00%    0.00%    0.00%   2027    0.00%  0.00%   0.00%   0.00%   0.00%   0.00%



                  Note:  Impact levels represent the percent change in population or employment due to the   proposal with respect
                         to total levels expected in absence of the proposal.

                Source3 USDOI, RKS, Gulf of Mexico OCS Region estimates, 1991.










                 IV454

                 contacting land will involve significant manpower requirements in their clean-up efforts. Based on employment
                 statistics from recent spill clean-up operations along the coast, the assumption is that, for every kilometer of
                 coastline subjected to heavy oiling, approximately 100 temporary workers will be employed for a maximum of
                 6 weeks.
                     Section IV.C.1. presents estimates of the mean number of offshore spills assumed to result from the
                 proposed action for the High Case in the WPA_ The probability that one or more spills greater than or equal
                 to 1,000 bbl will occur and contact land within 10 days of the accident is 2 percent (Table IV-22). Based on
                 the low probability of an offshore spill of this size occurring and contacting land within 10 dars, the assumption
                 is that no significant employment requirements will result from the clean-up of offshore spills of this size
                 category in the High Case. One spill of the size category greater than 50 bbl and less than 1,000 bbl is assumed
                 to occur (Table IV-3); however, it will not contact the coastline (Section IV.C.1.). Twenty spills of the size
                 category greater than 1 bbl and less than or equal to 50 bbl are assumed to occur in the W'PA over the fife
                 of the proposed action. However, none of these spills is assumed to contact land (Section IV.C.1.).
                 Furthermore, employment impacts resulting from the clean-up of offshore spills this small is assumed to be
                 negligible.
                     In addition to the small offshore spills referenced above, a number of small onshore spills are expected
                 to occur (Table IV-5). The level of clean-up action associated with spills of this size are minimal.
                     The greatest impact on population from activities associated with Sale 143 in the High Case is expected
                 in coastal Subareas C-1 and C-2 with peak-year impact estimates for 1998 of 0.25 and 0.40 percent, respectively
                 (Table IV-36). The communities of the Western Gulf coastal Subareas W-1 and W-2 have relatively small peak
                 population impacts of 0.02 and 0.03 percent, respectively.
                     The level of OCS-related employment expected to result from the proposed action for the High Case in
                 the Western Gulf is approximately two-and-a-half times as large as that estimated for the Base Case. However,
                 it is still not significant enough to attract new residents and labor force to the area. Analysis of historical trends
                 has shown that only population impacts greater than 1 percent typically involve positive net migration to any
                 given area. None of the coastal subareas is projected to experience population impacts greater than 1 percent
                 as the result of the proposed action in the High Case. Labor force impacts will parallel population and
                 employment impacts. Jobs are expected to be filled by currently unemployed or underemployed workers or
                 by future entrants into the labor force already living in the area. Therefore, employment demands in support
                 of the proposed action for the High Case in the Western Gulf will be met with the existing population and
                 available labor force.
                     Peak annual changes in the population, labor, and employment of all coastal subareas in. the Central and
                 Western Gulf resulting from the proposed action in the Western Gulf for the High Case represent less than
                 I percent of the levels expected in absence of the proposal. The coastal communities of the CPA are expected
                 to support over 75 percent of the total employment generated by the Western Gulf sale. The 'NTA contributes
                 the remaining 25 percent of total employment impacts. Employment resulting from oil-spill clean-up activities
                 due to the proposed action is negligible. It is expected that employment demands in support of the proposed
                 action will be met with the existing population and available labor force in the region.

                 Conclusion


                     The High Case impact of the proposed action in the Western Gulf on the population, labor, and
                 employment of the counties and parishes of the Central and Western Gulf coastal impact area is expected to
                 be less than 1 percent of the levels expected in the absence of the proposal.

                 (b) Public Services and Infrastructure

                     Public services and infrastructure, as used in this analysis, include commonly provided public, semipublic,
                 and private services and facilities, such as education, police and fire protection, sewage treatment, solid-waste
                 disposal, water supply, recreation, transportation, health care, other utilities, and housing. Changes in demands
                 for and usage of public services and infrastructure could result from OCS activities. Adverse effects could arise










                                                                                                                          IV-455

               if the amount or rate of increase or decrease in the usage significantly exceeded or fell far below the capability
               of a local area to provide a satisfactory level of service.
                   Sections providing supportive material for this analysis include Sections III.C.2. (description of
               socioeconomic issues), IV.A.2. (offshore infrastructure), IV.A.3. (onshore infrastructure), IV.C. 1. and 3. (oil
               spills), and IV.D.2.a.(11)(a) (impacts on population, labor, and employment).
                   For the purpose of this analysis, OCS-related, impact-producing factors to public services and community
               infrastructure will include work force fluctuations, migration (both in-migration and out-migration), and the
               effect of relative income. These impact-producing factors are interrelated and derive from or result in
               increased population. It should be noted that these impact-producing factors also pertain to social patterns
               and will be analyzed in Section IV.D.2.a.(11)(c).

               Base Case Analysis

                   Baseline employment projections and information relating to the model analysis used to arrive at these
               projections are presented in Section IVD.2.a.(11)(a). This information is incorporated by reference.
               Unexpected events (such as the 1973 Arab Oil Embargo) may influence oil and gas activity within the Gulf of
               Mexico Region. These events cannot be projected and will not be considered in this analysis.
                   Approximately 24,014 person-years of employment (direct, indirect, and induced) are required to sustain
               the proposed action throughout its 35-year life (Table IV-33). Over 72 percent of the total employment
               generated by the proposed action in the Western Gulf is expected to be supported by the CPA coastal
               communities. Total employment breakdown by coastal subarea for the life of the proposed action is 5 percent
               for Subarea W-1, 23 percent for Subarea W-2, 19 percent for Subarea C-1, and 53 percent for Subarea C-2.
               In the peak year of 1997, approximately 1,486 person-years of total employment will be required to support
               the proposed action. The greatest amount of this employment is expected to lie within Subarea C-2. A
               comparison between the expected population and employment impacts for the coastal subareas as a result of
               the proposed action and the expected population and employment without the proposal may be seen in Table
               IV-34. The greatest impact to employment is expected to occur in coastal Subareas C-1 and C-2, with peak-
               year impact estimates in 1997 of 0.11 and 0.17 percent, respectively.
                   A major impact of OCS-generated activities, new population associated with increased service demands,
               will be significantly mitigated by planning and other measures undertaken at the Federal, State, regional, and
               local levels. All the potential onshore development areas either have or participate in local and/or regional
               planning programs. The objectives of these programs include orderly and efficient growth management that
               minimizes fiscal, social, and environmental impacts. This analysis assumes that future Federal, State, and local
               management efforts will be effective at avoiding or mitigating many potential adverse effects on the quality of
               public services and infrastructure that might occur as a result of the kinds of planned, long-term economic
               growth and development anticipated by the local and regional planning community.
                   Short-term fluctuations in the work force as a result of changing levels of OCS-related oil and gas activity
               could impact social services and community infrastructure in several ways. Large amounts of short-term layoffs
               of oil and gas industry personnel could stress the abilities (both in terms of work load and available funding)
               of public and private agencies whose mission is to aid persons with severe financial difficulties. The need for
               public or private assistance could force the diversion of funds needed for the maintenance of community
               infrastructure, such as schools and roads. Large, short-term increases in the work force could result in net
               positive migration and cause a scarcity of housing, a shortage of municipal personnel (i.e., policemen, firemen,
               engineers, etc.), and an increase in the cost of living. A comparison with Table IV-34 reveals that there are
               no significant differences expected in population and employment between the proposed action and levels
               expected without the proposal in coastal Subareas C-3 and C4. None of the coastal subareas in the CPA and
               WPA is expected to experience population impacts greater than 0.17 percent (1997-peak year) as a result of
               the proposed action. It is expected that employment related to the proposed action will not require
               importation of labor and that the existing labor pool will be adequate to supply labor needs. The proposed
               action is expected to provide jobs for unemployed, underemployed, and new employees already living in the
               area (Section IV.D.2.a.(11)(a)). Excess labor capacity of the coastal subareas is expected to provide sufficient
               human resources to maintain adequate levels of public services and infrastructure.










                  IV456

                      Migration into a coastal subarea (in-migration) as a response to increased levels of OCS-related off and
                  gas activity could result in increased stress on both public and private agencies in assisting newly relocated
                  persons and in providing basic services to an expanding population. In addition, not all persons who migrate
                  to an area seeking employment will find it. This failure causes additional stress on social service agencies. In-
                  migration into an area may result in dramatic population increases, stressing community schools, roads, law
                  enforcement agencies, and other community infrastructure. Migration out of a coastal subarea (out-migration)
                  in response to lowered levels of OCS-related off and gas activity could jeopardize secondajqt and tertiary jobs
                  that were created during periods of increased population, stressing social service agencies. Community
                  infrastructure created in response to a larger population could become a redundant expense as a result of out-
                  migration. An analysis of historical trends indicates that population impacts of greater than I percent involve
                  positive net migration into a given area. Table IV-34 indicates that population impacts are not expected to
                  exceed this figure under the Base Case. Therefore, it is expected that the proposed action will not produce
                  in-migration into the coastal subareas of the Gulf of Mexico. The proposed action will result in the need for
                  approximately 24,014 person-years of total employment throughout its 35-year fife. These jobs are expected
                  to be filled by unemployed, underemployed, and newly employed persons already living in the area. By
                  providing these jobs, the proposed action will reduce the amount of out-migration comparative to that which
                  might occur without the proposal.
                      The relatively high wages paid to OCS-related oil and gas industry personnel could result in an increase
                  in population from in-migration and a concomitant increase in the local cost of living. Impacts to social services
                  could come from the need for assistance of those living on fixed incomes, as well as those unemployed as a
                  result of the decline of businesses unable to operate in an environment of high wage scale. Impacts to
                  community infrastructure could come from the defection of community workers from infrastructure-related
                  activities to higher paying jobs in the oil and gas industry. The employment needs of the proposed action are
                  not expected to exceed the labor capacity of the Gulf coastal subareas. As mentioned above, an analysis of
                  historical trends indicates that in-migration should not be expected as a result of the proposed action. In
                  addition, jobs created by the proposal would likely reduce the amount of migration out of the coastal subareas
                  when compared to scenarios without the proposal. It is expected that employees leaving public service and
                  infrastructure-based jobs could be replaced by the existing labor pool and area residents, entering the job
                  market. Revenues generated by Federal, State, and local taxes from employment related to the proposed
                  action are expected to mitigate any increased needs for public services generated by the proposed action.

                  Summaq

                      Impacts to public services and infrastructure would be related to dramatic population increases or
                  decreases, which are not projected as a result of the proposed action. Specific impact-producing factors
                  examined in this analysis include work force fluctuations, migration into or out of the coastal subareas, and the
                  relatively high wages made by personnel involved in the oil and gas industry. An analysis of historical trends
                  indicates that population impacts of greater than I percent involve positive net migration into a given area.
                  Under the Base Case, population impacts are not expected to exceed peak-year impacts of 0.17 percent. No
                  positive net migration into the coastal subareas of the Central and Western Gulf is expected to occur as a result
                  of the proposed action. It is expected that employment needs will be met by those currend, employed in the
                                                                                                                 Y
                  oil and gas industry as well as the unemployed and the underemployed, and new employees already living in
                  the area. In addition, jobs created by the proposal would likely reduce the amount of migration out of the
                  coastal subareas when compared to scenarios without the proposal. It is expected that employees leaving
                  public service and infrastructure-related jobs could be replaced from the existing labor pool.

                  Conclusion


                      Population and employment impacts that result from the proposed action under the Base Case scenario
                  will not result in disruption to community infrastructure and public services beyond what is anticipated by in-
                  place planning and development agencies.










                                                                                                                           IV-457

                High Case Ana4wis

                    Baseline employment projections and information relating to the model analysis used to arrive at these
                projections are presented in Section IV.13.2.a.(11)(a). This information is incorporated by reference.
                Unexpected events (such as the 1973 Arab Oil Embargo) may influence oil and gas activity within the Gulf of
                Mexico Region. These events cannot be projected and will not be considered in this analysis.
                    Approximately 62,594 person-years of employment (direct, indirect, and induced) are required to sustain
                the proposal under the High Case throughout its 35-year life (Table IV-35). Over 75 percent of the total
                employment generated by the High Case in the Western Gulf is expected to be supported by the CPA coastal
                communities. Total employment breakdown by coastal subarea for the life of the proposal under the High
                Case is 3 percent for Subarea W-1, 22 percent for Subarea W-2, 19 percent for Subarea C-1, and 56 percent
                for Subarea C-2. In the peak year of 1998, approximately 3,425 person-years of total employment are required
                to support the High Case. The greatest amount of this employment is expected to lie within Subarea C-2. A
                comparison between the expected population and employment impacts for the coastal subareas as a result of
                the High Case and the expected population and employment without the proposal may be seen in Table IV-38.
                The greatest impact to employment is expected to occur in coastal Subareas C-1 and C-2, with peak-year
                impact estimates in 1998 of 0.24 and 0.39 percent, respectively.
                    A major impact of OCS-generated activities, new population associated with increased service demands,
                will be significantly mitigated by planning and other measures undertaken at the Federal, State, regional, and
                local levels. All of the potential onshore development areas either have or participate in local and/or regional
                planning programs. The objectives of these programs include orderly and efficient growth management that
                minimizes fiscal, social, and environmental impacts. This analysis assumes that future Federal, State, and local
                management efforts will be effective at avoiding or mitigating many potential adverse effects on the quality of
                public services and infrastructure, effects that might occur as a result of the kinds of planned, long-term
                economic growth and development anticipated by the local and regional planning community.
                    Short-term fluctuations in the work force as a result of changing levels of OCS-related oil and gas activity
                could impact social services and community infrastructure in several ways. Large amounts of short-term layoffs
                of oil and gas industry personnel could stress the abilities (both in terms of work load and available funding)
                of public and private agencies whose mission is to aid persons with severe financial difficulties. The need for
                public or private assistance could force the diversion of funds needed for the maintenance of community
                infrastructure, such as schools and roads. Large, short-term increases in work force could result in net positive
                migration and cause a scarcity of housing, a shortage of municipal personnel (i.e., policemen, firemen,
                engineers, etc.), and an increase in the cost of living. A comparison with Table IV-36 reveals that there are
                no significant differences in population and employment between the proposed action and the levels expected
                without the proposal in coastal Subareas C-3 and C-4. None of the coastal subareas in the CPA and WPA is
                expected to experience population impacts greater than 0.40 percent (1998-peak year) as a result of the High
                Case. It is expected that employment related to the High Case will not require importation of labor and that
                the existing labor pool will be adequate to supply labor needs. The High Case is expected to provide jobs for
                the unemployed and the underemployed, and new employees already living in the area (Section
                IV.13.2.a.(11)(a)). Excess labor capacity of the coastal subareas is expected to provide sufficient human
                resources to maintain adequate levels of public services and infrastructure.
                    Migration into a coastal subarea (in-migration) as a response to increased levels of OCS-related oil and
                gas activity could result in increased stress on both public and private agencies in assisting newly relocated
                persons and in providing basic services to an expanding population. In addition, not all persons who migrate
                to an area seeking employment will find it, causing additional stress on social service agencies. In-migration
                may result in dramatic population increases, stressing community schools, roads, law enforcement agencies, and
                other community infrastructure. Migration out of a coastal subarea (out-migration) in response to lowered
                levels of OCS-related oil and gas activity could jeopardize secondary and tertiary jobs that were created during
                periods of increased population, stressing social service agencies. Community infrastructure created in response
                to a larger population could become a redundant expense as a result of out-migration. An analysis of historical
                trends indicates that population impacts of greater than I percent involve positive net migration into a given
                area. Table IV-38 indicates that population impacts are not expected to exceed this figure under the High










                IV458

                Case. It is therefore expected that the proposal will not produce in-migration into the coastal subareas of the
                Gulf of Mexico. The High Case will result in the need for approximately 62,594 person-years of total
                employment throughout the 35-year life of the proposed action. These jobs are expected to be filled by the
                unemployed and the underemployed and newly employed persons already living in the area. By providing these
                jobs, the High Case will reduce the amount of out-migration compared to that which might cccur without the
                proposal.
                     The relatively high wages paid to OCS-related off and gas industry personnel could result in a population
                increase from in-migration and a concomitant increase in the local cost of living. Impacts to social services
                could come from the need for assistance of those living on fixed incomes, as well as those unemployed
                as a result of the decline of businesses unable to operate in an environment of high wage scale. Impacts to
                community infrastructure could come from the defection of community workers from infrastructure-related
                activities to higher paying jobs in the oil and gas industry. The employment needs of the High Case are not
                expected to exceed the labor capacity of the Gulf coastal subareas. As mentioned above, an analysis of
                historical trends indicates that in-migration should not be expected as a result of the proposal. Inaddition,jobs
                created by the proposal would likely reduce the amount of migration out of the coastal subareas when
                compared to scenarios without the proposal. It is also assumed that the High Case will not produce out-
                migration from the Coastal Subareas of the Gulf of Mexico. It is expected that employees leaving public
                service and infrastructure-based jobs could be replaced from the existing labor pool and new employees in the
                area entering the job market Revenues generated by Federal, State, and local taxes from em- loyment related
                to the High Case are expected to mitigate any increased needs for public services generated by the proposal.
                     Impacts to public services and infrastructure would be related to dramatic population increases or
                decreases, which are not projected as a result of the proposed action. Specific impact-producing factors
                examined in this analysis include work force fluctuations, migration into or out of the coastal subareas, and the
                relatively high wages made by personnel involved in the oil and gas industry. An analysis of historical trends
                indicates that population impacts of greater than I percent involve positive net migration into a given area.
                Under the High Case, population impacts are not expected to exceed a peak-year (1998) impact of 0.40
                percent. No positive net migration into the coastal subareas of the Central and Western Gulf is expected to
                occur as a result of the High Case. It is expected that employment needs will be met by those currently
                employed in the off and gas industry as well as the unemployed and the underemployed, and new employees
                already living in the area. In addition, jobs created by the proposal would likely reduce migration out of the
                coastal subareas when compared with scenarios without the proposal. It is expected that employees leaving
                public service and infrastructure-related jobs could be replaced from the existing labor pool.

                Conclusion


                     Population and employment impacts that result from the proposed action under the High Case scenario
                will not result in disruption to community infrastructure and public services beyond what is anticipated by in-
                place planning and development agencies.

                (c) Social PaUems

                     This impact analysis includes the coastal parishes and counties of the Central and Western Gulf of Mexico
                (Section III.C.2.(a)). Social patterns, as used in this analysis, include traditional occupations, folkways, social
                structure, language, family life, and other forms of cultural adaptation to the natural and human environment.
                It should be noted that impacts unrelated to OCS oil and gas activity (such as technological ihiprovements in
                communications and transportation) have caused, and will continue to cause, changes within the analysis area.
                However, the present analysis will consider only the effects of OCS-related oil and gas activity on the social
                patterns of the Central and Western Gulf coastal subareas.
                     Sections providing supportive material for this analysis include Sections III.C.3. (description of
                socioeconomic issues), IVA (offshore infrastructure), IV.C.l. and 3. (oil spills), IV.D.2.a.(1)(b) (impacts on











                                                                                                                           IV-459

                sensitive coastal environments), IV.D.2.a.(8) (impacts on commercial fisheries), IV.13.2.a.(11)(a) (impacts on
                population, labor, and employment), and IV.13.2.a.(11)(b) (impacts on public services and infrastructure).
                    For the purpose of this analysis, OCS-related, impact-producing factors to social patterns will include work
                force fluctuations, net migration (both in-migration and out-migration), work scheduling, displacement from
                traditional occupations, and relative income. Many of these impact-producing factors result in or derive from
                population growth. Adverse effects to social patterns could arise if disruption of social patterns occurred and
                resulted in changes in traditional occupations, disruption in the viability of extant subcultures, and detrimental
                effects on family life. As mentioned in Section III.C.2.c., it may be argued that employment in the oil and gas
                industry could be perceived as a traditional occupation; however, for the purpose of this analysis, it will not
                be so.


                Base Case Ana6wis

                    Baseline employment projections and information relating to the model analysis used to arrive at these
                projections are presented in Section IV.13.2.a.(11)(a). This information is incorporated by reference.
                Unexpected events (such as the 1973 Arab Oil Embargo) may influence oil and gas activity on the OCS within
                the Gulf of Mexico Region. These events cannot be projected and cannot be presumed for this analysis.
                    The proposed action will result in approximately 24,000 person-years of employment (direct, indirect, and
                induced) throughout its 35-year life (Table IV-33). Over 72 percent of the total employment generated by the
                proposed action in the Western Gulf is expected to be supported by the CPA coastal communities. Total
                employment breakdown by coastal subarea for the life of the proposed action is 5 percent for Subarea W-1,
                23 percent for Subarea W-2, 19 percent for Subarea C-1, and 53 percent for Subarea C-2. In the peak year
                of 1997, approximately 1,500 person-years of total employment are required to support the proposed action.
                The greatest amount of this employment is expected to lie within Subarea C-2. A comparison between the
                expected population and employment impacts for the coastal subareas as a result of the proposed action and
                the expected population and employment without the proposal is shown in Figure IV-10 and in Table IV-34.
                The greatest impact to employment is expected to occur in coastal Subareas C-1 and C-2, with peak-year
                impact estimates in 1997 and 1998 of 0.11 and 0.17 percent, respectively.
                    Short-term fluctuations in the workforce as a result of changing levels of activities could affect social
                patterns in several ways. Large amounts of short-term layoffs in oil and gas industry personnel could result
                in large numbers of persons returning to traditional ways of employment (i.e., fishing, trapping, farming, etc.),
                thereby stressing the various resources that would be exploited. A large increase in the hiring of off and gas
                industry personnel could attract persons engaged in traditional occupations, leaving fewer persons in them in
                the coastal subareas and, perhaps, resulting in the loss of traditional knowledge associated with these
                occupations.
                    The potential effects of work force fluctuations on extant subcultures in the coastal subareas are expected
                to be greatest when large changes in OCS-related activity result in net positive or negative migration. The
                quality of family life, in pertinent individual cases, could be adversely affected from the stress of decreased
                family income and loss of security resulting from layoffs in the OCS oil and gas industry. The expected impact
                on family life, in pertinent individual cases, from increased hiring in the OCS-related off and gas industry would
                be decreased monetary stress and an increased financial security. Problems related to work scheduling may
                arise and are discussed below. As mentioned above, employment impacts under the proposed action are not
                expected to exceed 0.17 percent in the peak years of 1997 and 1998. Projected employment associated with
                the proposed action is expected to come from those already employed in OCS-related activities and from the
                unemployed and underemployed, and new employees already living in the coastal subareas. It is expected that
                the proposed action will not result in large increases or decreases in OCS-related employment within the
                Central and Western Gulf coastal subareas.
                    Both in-migration and out-migration could adversely affect social patterns in the Central and Western Gulf
                coastal subareas. Expected adverse effects of in-migration include the loss of cultural homogeneity, the loss of
                community cohesion, and changes in the quality of life with possible associated stresses to social patterns.
                Expected adverse effects of out-migration include stress placed on family life by the departure of extended
                family members; the departure of persons who are engaged, part-time, in traditional occupations, and impacts










                 IV-460

                 to community cohesion by the departure of long-time residents. Projected population impacts in the Central
                 and Western Gulf coastal subareas are not expected to exceed 0.17 percent (1997 and 1998--peak years). An
                 analysis of historical trends indicates that only population impacts greater than 1 percent typically. involve
                 positive net migration into a given area. None of the coastal subareas is projected to experience population
                 impacts greater than I percent as a result of the proposed action. Employment in support of the proposed
                 action is expected to come from those currently employed in OCS-related oil and gas activities as well as the
                 unemployed and underemployed, and new employees already living in the area. It is assumed that employment
                 as a result of the proposal will decrease the amount of out-migration compared to that which would occur
                 without the proposal.
                     Distance to the site and the type of transportation needed for personnel in OCS-retated oil and gas
                 activities result in the normal work schedule occurring as a large block of time on duty (or at site) followed by
                 a large block of time off duty. The schedules may range from 7 days on followed by 7 days. off to a 30 day-
                 on/30 day-off schedule. It has been argued that this type of schedule has allowed for the participation in, and
                 continuance of, traditional occupations (Hallowell, 1979; Laska, personal comm., 1991). It is expected that
                 stress will be placed on family life in response to the regular absences of a parent (usually the father). In some
                 cases, however, it is expected that adaptation to changing family roles will occur. In other cases, however, it
                 is expected that adaptation will not occur and that deleterious impacts to family life, in pertinent individual
                 cases, will occur. In the peak years of 1997 and 1998, approximately 1,500 person-years of total employment
                 are required to support the proposed action. Many of those employed will be working in secondary and
                 tertiary jobs and will not encounter the extended work schedule mentioned above. Impacts to family fife are
                 expected to be serious in some individual cases.
                     Displacement from traditional occupations could originate from destruction of a resource. base, space-use
                 conflict, and voluntary shifts from traditional occupations to employment in OCS-related ac,dvities. Adverse
                 effects resulting from displacement from traditional occupations could include a diminishment in the number
                 of participants in traditional occupations, the loss of traditional knowledge and cultural heritage, and deleterious
                 impacts to family life. Space-use conflicts have been discussed in Section IV.D.2.a.(8). The existence of the
                 Fisherman's Contingency Fund mitigates, to some extent, space-use conflicts associated with commercial fishing.
                 A total of 239 claims was filed in 1990 and $212,453.24 were paid to persons attributing damage to OCS-related
                 debris. According to Sections IV.D.La.(I)(b) and IV.13.2.a.(I)(b), the proposed action is expected to have a
                 very low impact on coastal wetlands in both the CPA and WPA_ It is therefore assumed that very little
                 displacement from traditional occupations will occur as a result of OCS-related destruction of wetlands. As
                 mentioned above, the extended work schedule associated with many OCS-related jobs may allow for continued
                 participation in traditional occupations. It is expected that relatively few persons will be: displaced from
                 traditional occupations as a result of the proposed action.
                     The relatively high wages paid to OCS-related oil and gas industry personnel can result in the voluntary
                 shift of persons engaged in traditional occupations to more lucrative positions within the oil and gas industry.
                 Dependency on these relatively high wages may have deleterious impacts on family life, pariicularly if layoffs
                 occur and the wage-earner cannot find work at comparable pay. It is assumed that some persons engaged in
                 lower-paying traditional occupations will seek employment in OCS-related oil and gas activities. Thoseengaged
                 in extended work schedules will retain the ability to participate in traditional occupations on it part-time basis.
                 Employment projections for the life of the proposed action indicate that peak-year employment (1997 and
                 1998) will total approximately 1,485 persons for each of the two peak years throughout the Central and
                 Western Gulf coastal subareas. It is expected that employment will come from persons already working in
                 OCS-related oil and gas activities, as well as the unemployed and underemployed, and new employees already
                 living in the area. The relatively small amount of employment associated with the proposed action in
                 comparison with total employment in the Central and Western Gulf lessens the impact of relatively high wages
                 paid to OCS-related oil and gas industry personnel on social patterns.

                 Summary

                     Impacts on social patterns would be related to dramatic changes in population and the disruption of
                 environmental resources, as well as conditions inherent to OCS-related employment (i.e., work scheduling and










                                                                                                                        IV461

              rate of pay). Specific impact-producing factors examined in this analysis include work force fluctuations,
              migration into or out of the coastal subareas, work scheduling, displacement from traditional occupations, and
              relative income. An analysis of historical trends indicates that population impacts of greater than I percent
              typically involve positive net migration into a given area. Under the Base Case, population impacts are not
              expected to exceed the peak-year impact of 0.17 percent. No positive net migration into Central and Western
              coastal subareas is expected to occur as a result of the proposal and that employment will occur from those
              currently employed in the oil and gas industry, as well as the unemployed and underemployed, and new
              employees already living in the area. It is expected that jobs created by the proposal would likely reduce the
              amount of out-migration when compared to scenarios without the proposal. It is expected that minor
              displacement from traditional occupations will occur as a result of the proposed action. This displacement will
              be mitigated, to some extent, by the extended work schedule associated with OCS-related employment. The
              extended work schedule is expected to have some deleterious effects on family life in some individual cases.
              Impacts caused by the displacement of traditional occupations and relative wages are expected to occur to a
              minimal extent.


              Conclusion


                   No net migration is expected to occur as a result of the proposed action. Deleterious impacts on social
              patterns are expected to occur in some individual cases as a result of extended work schedules, displacement
              from traditional occupations, and relative wages.

              High Case Ana4uis

                   Baseline employment projections and information relating to the model analysis used to arrive at these
              projections are presented in Section IV.13.2.a.(11)(a). This information is incorporated by reference.
              Unexpected events (such as the 1973 Arab Oil Embargo) may influence oil and gas activity on the OCS within
              the Gulf of Mexico Region. These events cannot be projected and cannot be presumed for this analysis.
                   Approximately 62,600 person-years of employment (direct, indirect, and induced) are required to sustain
              the proposed action in the High Case throughout its 35-year life (Table IV-35). Over 75 percent of the total
              employment generated by the High Case in the Western Gulf is expected to be supported by the CPA coastal
              communities. Total employment breakdown by coastal subarea for the life of the proposed action under the
              High Case is 3 percent for Subarea W-1, 22 percent for Subarea W-2, 19 percent for Subarea C-1, and 56
              percent for Subarea C-2. In the peak year of 1998, approximately 3,400 person-years of total employment are
              required to support the High Case. The greatest amount is expected to occur within Subarea C-2. A
              comparison between the expected population and employment impacts for the coastal subareas as a result of
              the High Case and the expected population and employment without the proposal is shown in Table IV-35.
              The greatest impact to employment is expected to occur in coastal Subareas C-I and C-2, with peak-year
              impact estimates in 1998 of 0.24 and 0.39 percent, respectively.
                   Short-term work force fluctuations as a result of changing levels of activities could affect social patterns
              in several ways. Urge amounts of short-term layoffs in oil and gas industry personnel could result in large
              numbers of persons returning to traditional ways of employment (i.e., fishing, trapping, farming, etc.), thereby
              stressing the various resources that would be exploited. A large increase in the hiring of oil and gas industry
              personnel could attract persons engaged in traditional occupations, leaving fewer persons in them in the
              coastal subareas and, perhaps, resulting in the loss of traditional knowledge associated with these occupations.
                   The potential effects of work force fluctuations on extant subcultures in the coastal subareas are expected
              to be greatest when large changes in OCS-related activity result in net positive or negative migration. The
              quality of family life, in pertinent individual cases, could be adversely affected from the stress of decreased
              family income and loss of security resulting from layoffs in the oil and gas industry. The expected impact on
              family life, in pertinent individual cases, from increased hiring in the OCS-related oil and gas industry would
              be decreased monetary stress and an increased financial security. Problems related to work scheduling may
              arise and are discussed below. As mentioned above, employment impacts under the High Case are not
              expected to exceed 0.39 percent in the peak year of 1998. Projected employment associated with the proposal










                  IV-462

                  is expected to come from those already employed in OCS-related activities and from the unemployed and
                  underemployed, and new employees already living in the coastal subareas. It is expected that the High Case
                  will not result in large increases or decreases in OCS-related employment within the Central and Western Gulf
                  coastal subareas.
                      Both in-migration and out-migration could have an adverse effect on social patterns hi the Central and
                  Western Gulf coastal subareas. Expected adverse effects of in-migration could include the loss of cultural
                  homogeneity, the loss of community cohesion, and changes in the quality of life with possible associated stresses
                  to social patterns. Expected adverse effects of out-migration could include stress placed on family life by the
                  departure of extended family members; the departure of persons engaged, part-time, in traditional occupations;
                  and impacts to community cohesion by the departure of long-time residents. As mentioned above, projected
                  population and employment impacts in the Central and Western Gulf coastal subareas are not expected to
                  exceed 0.40 percent (1998-peak year). An analysis of historical trends indicates that only population impacts
                  greater than 1 percent typically involve positive net migration into a given area. None of the coastal subareas
                  is projected to experience population impacts greater than I percent as a result of the High Case. Employment
                  in support of the proposal is expected to come from those currently employed in OCS-related oil and gas
                  activities as well as the unemployed and underemployed, and new employees already living in the area. It is
                  assumed that employment as a result of the proposal will decrease the amount of out-migration, compared to
                  that which would occur without the proposal.
                      Distance to the site and the type of transportation needed for personnel in OCS-related oil and gas
                  activities result in the normal work schedule occurring as a large block of time on duty (or at site) followed by
                  a large block of time off duty. The schedules may range from 7 days on followed by 7 days off to a 30 day-
                  on/30 day-off schedule. It has been argued that this type of schedule has allowed for the participation in, and
                  continuance of, traditional occupations (Hallowell, 1979; Laska, personal. comm., 1991), thereby assisting in
                  the maintenance of cultural viability. It is expected that stresses will be placed on family life in response to
                  the regular absences of a parent (usually the father). In some cases, it is expected that adaptation to changing
                  family roles will occur. In other cases, it is expected that adaptation will not occur and that deleterious impacts
                  to family life, in pertinent individual cases, will occur. In the peak year of 1998, approximately 3,400 person-
                  years of total employment are required to support the proposed action. Many of those employed will be
                  working in secondary and tertiary jobs and will not encounter the extended work schedule mentioned above.
                  Of those persons employed in OCS-related oil and gas activity and working the extended schedule, it is
                  expected that some families will not adapt to these conditions and that deleterious impacts to family life will
                  occur. Impacts to family life are expected to be serious in some individual cases.
                      Displacement from traditional occupations could originate from destruction of a resource base, space-use
                  conflict, and voluntary shifts from traditional occupations to employment in OCS-related activities. Adverse
                  effects resulting from displacement from traditional occupations could include a diminishment in the number
                  of participants in traditional occupations, the loss of traditional knowledge and cultural heritage, and deleterious
                  impacts to family life as a result of the displacement. Space-use conflicts have been discussed in Section
                  IV.D.2.a.(8). The existence of the Fisherman's Contingency Fund mitigates, to some extent, space-use conflicts
                  associated with commercial fishing. A total of 239 claims was filed and $212,453.24 were paid to persons
                  attributing damage to OCS-related debris. According to Sections IV.D.La.(l)(b) and IV.D.2.a.(l)(b), the High
                  Case is expected to have a very low impact on coastal wetlands in both the CPA and WP,&- It is therefore
                  assumed that very little displacement from traditional occupations will occur as a result of OCS-related
                  destruction of wetlands. As mentioned above, the extended work schedule associated with niany OCS-related
                  jobs may allow for continued participation in traditional occupations. It is expected that relatively few persons
                  will be displaced from traditional occupations as a result of the High Case.
                      The relatively high wages paid to OCS-related off and gas industry personnel can result in the voluntary
                  shift of persons engaged in traditional occupations to more lucrative positions within the oil and gas industry.
                  Dependency on these relatively high wages may have deleterious impact on family life, particularly if layoffs
                  occur and the wage-earner cannot find work at comparable pay. It is assumed that some persons engaged in
                  lower-paying traditional occupations will seek employment in OCS-related oil and gas activities. Thoseengaged
                  in extended work schedules will retain the ability to participate in traditional occupations on a part-time basis.
                  Employment projections for the life of the proposed action under the High Case indicate that peak-year










                                                                                                                      IV-463

              employment (1998) will total approximately 3,400 persons throughout the Central and Western Gulf coastal
              subareas. It is expected that employment will come from persons already working in OCS-related oil and gas
              activities, as well as the unemployed and the underemployed, and new employees already living in the area.
              The relatively small amount of employment associated with the High Case in comparison with total
              employment in the Central and Western Gulf lessens the impact of relatively high wages paid to OCS-related
              oil and gas industry personnel on social patterns.
                   Impacts to social patterns would be related to dramatic changes in population and the disruption of
              environmental resources, as well as conditions inherent to OCS-related employment (Le., work scheduling and
              rate of pay). Specific impact-producing factors examined in this analysis include work force fluctuations,
              migration into or out of the coastal subareas, work scheduling, displacement from traditional occupations, and
              relative income. An analysis of historical trends indicates that population impacts of greater than 1 percent
              typically involve positive net migration into a given area. Population impacts under the High Case are not
              expected to exceed the peak-year impact of 0.40 percent. No positive net migration into Central and Western
              Gulf coastal subareas is expected to occur as a result ofthe proposal. It is expected that employment will
              occur from those currently employed in the oil and gas industry, as well as the unemployed and underemployed,
              and new employees already living in the area. It is expected that jobs created by the proposal would likely
              reduce the amount of out-migration when compared to scenarios without the proposal. It is also expected that
              minor displacement from traditional occupations will occur as a result of the proposed action. This
              displacement will be mitigated, to some extent, by the extended work schedule associated with OCS-related
              employment. However, the extended work schedule is expected to have some deleterious effects on family life
              in some individual cases. Impacts caused by the displacement of traditional occupations and relative wages are
              expected to occur to a minimal extent.

              Conclusion

                   No net migration is expected to occur as a result of the proposed action. Deleterious impacts on social
              patterns are expected to occur in some individual cases as a result of extended work schedules, displacement
              from traditional occupations, and relative wages.
              b. Alternative B - The Proposed Action Excluding the Blocks Near Biologically Sensitive
                   Topographic Features

                   Alternative B would offer 4,628 unleased blocks in the WPA for leasing; it differs from Alternative A (the
              proposed action) only by not offering the 87 unleased blocks of the 200 total blocks that are possibly affected
              by the Topographic Features Stipulation (Section II.B.l.c.(l)), plus the two deferred blocks at the Flower
              Garden Banks. All the assumptions and estimates are the same as in the Base Case of Alternative A. Details
              are presented in Sections I.A. and II.B.2.
                   The analyses of impacts are based on the Base Case scenario of Alternative A- These scenarios were
              formulated to provide sets of assumptions and estimates on the amounts, locations, and timing for OCS
              exploration, development, and production operations and facilities, both offshore and onshore. These are
              estimates only and not predictions of what will happen as a result of holding this proposed sale. A detailed
              discussion of the development scenarios and major related impact-producing factors is included in Sections
              IV.A. and B.
                   It should be emphasized that the analyses of impacts to the various resources under Alternative B are very
              similar to those for Alternative A. The reader should refer to the appropriate discussions under Alternative
              A for additional and more detailed information regarding impact-producing factors and their expected effects
              on the various resources.
                   To facilitate the analysis, the Federal offshore area is divided into subareas. The WPA is comprised of
              three subareas (W-1, W-2, and W-3) and the coastal region is divided into two coastal subareas (W-1 and W-2).
              These subareas are delineated on Figure IV-1.










                   IV464
                   (1) Impacts on Sensftive Coasial Environments

                   (a) Coastal Banier Beaches

                       The activities that could affect barrier beaches under Alternative B include oil spills, pipeline
                   emplacements, dredging of new navigation channels, maintenance dredging and vessel usage of existing,
                   navigation channels, and the construction of onshore facilities on barrier features. Alternative B does not
                   directly affect the severity of impacts expected from activities associated with OCS development because the
                   deleted offshore sensitive habitats are located at a distance offshore from coastal barriers.
                       No spills greater than or equal to 1,000 bbl or spills greater than or equal to 50 and less than 1,000 bb].
                   are assumed to occur and contact WPA coastal barriers under Alternative B. As in the Base Case, there is
                   a less than 0.5 percent chance of occurrence of and contact from a spill of 1,000 bbl or greater, and no spills
                   greater than or equal to 50 and less than 1,000 bbl are assumed to contact barrier features. One or two spills
                   greater than I and less than 50 bbl will occur inshore and contact the landward side of barrier beaches. These
                   spills will contact about 2 kni of coast and will be cleaned without the removal of sand. No off will contact sand
                   dune areas. The barrier features will not be affected by contact from these spills.
                       No pipeline landfalls, navigation channels, or new infrastructure construction projects are expected as a
                   result of Alternative B. Maintenance dredging of existing navigation channels cannot be attributed to
                   Alternative B because of the small percentage of vessel usage attributable to the Alternative.
                       No channel deepening projects will occur in an area that could affect barrier landforins.

                   Conclusion


                       Alternative B is not expected to result in permanent alterations of barrier beach configuration, except in
                   localized areas downdrift from channels that have been dredged and deepened. The contribution to this
                   localized erosion is expected to be less than 1 percent.

                   (b) Wedatuts

                       The activities that could affect wetlands under Alternative B include oil spills, pipeline emplacements,
                   dredging of new navigation channels, maintenance dredging and vessel usage of existing navigation channels,
                   and the construction of onshore facilities. Alternative B does not directly affect the severity of impacts
                   expected from activities associated with OCS development under the Base Case scenario, because the deleted
                   offshore sensitive habitats are located at a distance offshore coastal barrier habitats.
                       No spills greater than or equal to 1,000 bbl or spills greater than 50 bbl and less than 1,000 bbl are
                   assumed to occur and contact WPA coastal wetlands under Alternative B. As in the Base Case, there is a less
                   than 0.5 percent chance of occurrence and contact within 10 days from a spin greater than or equal to 1,000
                   bbl, and no spills greater than 50 and less than 1,000 bbl are assumed to contact wetlands. Several spills
                   greater than 1 and less than or equal to 50 bbl will occur from onshore sources and contact wetlands. These
                   spills will result in short-term impacts of up to several hectares of WPA wetlands, involving die-back of the
                   above-ground vegetation. No accelerated erosion of wetland margins is expected as a result of the spills.
                       Oil terminals and barge traffic do not commonly occur in WPA areas that contain extensive seagrass beds;
                   no impacts from off spills to these resources are therefore assumed to occur.
                       No pipeline landfalls, navigation channels, or new infrastructure construction projects are expected as a
                   result of Alternative B. Although no new waste disposal sites are projected to be built to accommodate OCS-
                   generated wastes, some seepage from existing sites could occur into nearby wetlands. Maintenance dredging
                   of existing navigation channels cannot be attributed to Alternative B because of the small percentage of vessel
                   usage that can be attributed to the alternative. The deepening of one navigation channel to    rovide access for
                   deeper draft service vessels is projected to occur. This analysis assumes that the dredged material will be used
                   to enhance or create marsh habitat Alternative B will result in a reduction in resource development compared
                   with the Base Case scenario. The amount of vessel traffic required under Alternative B lbr supply vessels,










                                                                                                                             IV-465

                 barges, and shuttle tankers will be less than or equal to that required under the Base Case. Impacts of OCS
                 vessel traffic on wetlands along channel margins are expected to be result in less than one hectare of
                 accelerated wetland erosion.


                 Conclusion

                     Alternative B is expected to result in no permanent alterations of wetland habitats, except for the erosion
                 of less than one ha. of wetlands along navigation channel margins. These losses could be offset or even
                 exceeded by wetlands gains from the beneficial disposal of dredged material generated during channel
                 maintenance and deepening operations.

                 (2) Impacts on Sensitive Offshore Resources

                 (a) Deep-water Benthic Communities

                     The sources and severity of impacts associated with this alternative are those sale-related activities
                 discussed for the Base Case. As noted in Section IV.D.2.a.(2)(a) for the Base Case, the only impact-producing
                 factor threatening these communities results from those activities that would physically disturb the bottom, such
                 as the routine operations of anchoring, drilling, and pipeline installation, and the rare seafloor blowoutaccident.
                 A more detailed examination of this potential impact-producing factor is presented in that section.
                     As noted in Section IV.D.2.a.(2)(a) above, high-density chemosynthetic communities are found only in
                 water depths greater than 400 m (1,312 ft). Thus, they will be found only in the southeast one-eighth of
                 Subarea W-1 and the southern one-third of W-2; they may be found throughout W-3. Thus, these
                 communities will not be exposed to the full level of the projected impact-producing factors of Table IV-3.
                 None of these excluded blocks are in areas in which chemosynthetic communities may be expected, because
                 the excluded blocks are in much shallower water near the topographic features.
                     The majority of these deep-water communities are of low density and are widespread throughout the deep-
                 water areas of the Gulf, and disturbance to a small area would not result in a major impact to the ecosystem.
                 For purposes of this analysis, the frequency of such impact is expected to be once every six months to two
                 years, and the severity of such an impact is judged to result in few losses of ecological elements with no
                 alteration of general relationships.
                     High-density communities are largely protected by the provisions of NTL 88-11. For purposes of this
                 analysis, the frequency of some small percentage of impact is expected to be once every six months to two
                 years, but the severity of such an impact is such that there may be some loss of ecological elements and/or
                 some alteration of general relationships.

                 Conclusion

                     Alternative B is expected to cause little damage to the physical integrity, species diversity, or biological
                 productivity of either the widespread, low-density chemosynthetic communities or the rare, widely scattered,
                 high-density Bush Hill-" chemosynthetic communities. Recovery from any damage is expected to take less
                 than two years.

                 (b) Topographic Features

                     The sources and severity of impacts associated with this alternative are those sale-related activities
                 discussed for the Base Case. As noted in Section IV.D.2.a.(2)(b) for the Base Case, the potential impact-
                 producing factors to the topographic features of the Western Gulf are anchoring and structure emplacement,
                 effluent discharge, blowouts, oil spills, and structure removal. A more detailed examination of these potential
                 impact-producing factors is presented in that section.










                  IV466

                       Eleven of the 23 topographic features of the Western Gulf are located in Subarea W-1; 12 are in W-2 (in
                  both cases they occupy a very small portion of the entire area). Thus, these communities will not be exposed
                  to the full level of the projected impact-producing factors of Table IV-3. This alternative differs from
                  Alternative A by excluding the 1 unleased block near the topographic features in W-1 and the 87 unleased
                  blocks near the banks in W-2. (These excluded blocks are the blocks that would be subject to the proposed
                  Topographic Features Stipulation under Alternative A. It should be noted that 113 of the total of 200 blocks
                  that would be subject to the stipulation are currently leased; 2 blocks at the Flower Garden Banks are deferred
                  from leasing.) The amounts of wastes discharged in the vicinity of a bank will be some veri small fraction of
                  those shown in Table IV-3.
                      Of the potential impact-producing factors to the topographic features, anchoring, structure emplacement,
                  and structure removal will be eliminated by the adoption of this alternative. Effluent discharge and blowouts
                  will not be a threat because blocks near enough to the banks for these events to have an impact on the biota
                  of the banks will have been excluded from leasing. Thus, the only impact-producing factor remaining, from
                  operations in blocks included in this alternative (i.e., those blocks not excluded by this alternative), is an oil
                  Spill.
                      There is an estimated 6 percent chance of an oil spill greater than or equal to 1,000 btil occurring in the
                  Western Gulf as a result of this alternative (it will be the same as the Base Case of Alternative A) (Table IV-
                  19), and it is assumed that 8 spills of greater than 1 and less than or equal to 50 bbl will oo.-ur each year and
                  that no spills of greater than 50 and less than 1,000 bbl will occur during the 35-year life of the proposed action.
                  In addition, it is assumed there will be 3 spills of diesel oil and other pollutants, the average size of which will
                  be only 34 bbI (Table IV-3) (Section IV.C.1.). No oil spill greater than or equal to 1,000 bbl is assumed to
                  occur during the 35-year life of the proposed action (Section IV.C.1.). In the Western GuH*, the East Flower
                  Garden Bank crests the shallowest at 15 in. Therefore, a surface oil spill would likely have no impact on the
                  biota of the East Flower Garden Bank or the other topographic features, because any oil that might be driven
                  to 15 in or deeper would be well below the concentrations needed to cause an impact. However, spills
                  resulting from this proposal are assumed to be subsurface; such spills are likely to rise to the surface, and any
                  oil remaining at depth will be swept clear of the banks by currents moving around the banks (Rezak et al.,
                  1983). A seafloor oil spill would have to come into contact with a biologically sensitive feature to have an
                  impact. The fact that the topographic features arc widely dispersed in the Western Gulf, combined with the
                  probable random nature of spill locations, would serve to limit the extent of damage from any given spill to
                  only one of the sensitive areas. The currents that move around the banks will steer any spilled oil around the
                  banks rather than directly upon them, lessening the severity of impacts.

                  Conclusion


                      Alternative B is expected to cause little to no damage to the physical integrity, species diversity, or
                  biological productivity of the habitats of the topographic features of the Gulf of Mexico. Small areas of 5-10
                  1112 would be impacted, and recovery from this damage to pre-impact conditions is expected to take less than
                  2 years, probably on the order of 24 weeks. Selection of Alternative B would preclude oil and gas operations
                  in the unleased blocks affected by the proposed Topographic Features Stipulation.
                  (3) Impacts on Water Qua1hy

                      All existing onshore infrastructure and associated coastal activities occurring in support of the proposed
                  action will contribute to the degradation of regional coastal and nearshore water quality to a minor extent
                  because each provides a low measure of continuous contamination and because discharge locations are
                  widespread. The effect of chronic contamination on the Gulfs coastal waters due to the proposed action is
                  considered negligible, with water characteristics rapidly returning to background levels. The OCS-related vessel
                  traffic is likely to impact water quality through routine releases of bilge and ballast waters, chronic fuel and tank
                  spills, trash, and low-level releases of the contaminants in antifouling paints. Given the small concentrations
                  of the releases anticipated, and their continuous and widespread nature, it is assumed that there will be some










                                                                                                                            IV-467

                localized short-term change (up to several weeks) in water quality characteristics from background levels,
                depending on the length of the affected channel, flushing rates, and other factors. The improper storage and
                disposal of offfield wastes and contaminated ofifield equipment would adversely impact surface and ground
                waters in proximity to disposal facilities, cleaning sites, and scrap yards. Surface and groundwater in proximity
                to improperly designed and maintained disposal sites and facilities could be adversely impacted with elevated
                concentrations of arsenic, chromium, zinc, cadmium, mercury, lead, barium, penta-chlorophenol, naphthalene,
                benzene, toluene, and radium.
                    Immediate effects would be brought about by increased drilling, construction, and pipelaying activities,
                causing an increase in water column turbidities (lasting for several hours for mud discharges to several weeks
                for pipelaying and dredging activities) to the affected offshore waters. The magnitude and extent of turbidity
                increases would depend on the hydrographic: parameters of the area, nature and duration of the activity, and
                bottom-material size and composition. Offshore Subarea W-1 would receive the greatest portion of program-
                related pipeline burial activities, whereas offshore Subarea W-3 would receive the largest amounts of program-
                related operational discharges. Because of the continuous nature of off and gas activities in the northwestern
                and north-central Gulf of Mexico, discharges of drilling muds and cuttings and produced water are judged to
                be of nearly continuous frequency throughout these areas. Proposed produced-water discharges will be rapidly
                diluted within the immediate vicinity of the discharge source. Significant increases in water concentrations of
                dissolved and particulate hydrocarbons and trace metals are not expected outside the initial mixing zone or
                immediate vicinity of the discharge source. Higher concentrations of trace metals, salinity, temperature, organic
                compounds, and radionuclides, and lower dissolved oxygen may be present near the discharge source. Within
                the mixing zone of the discharge, long-term effects to water column processes, consisting of localized increases
                in particulate metal and soluble lower molecular weight hydrocarbon (e.g., benzene, toluene, and Xylenes)
                concentrations, may be implicated. Trace metals and hydrocarbons associated with the discharge may be
                deposited within sediments near the discharge point. The proposed discharge of drilling fluids and cutting
                would encounter rapid dispersion in marine waters. Discharge plumes will be diluted to background levels
                within a period of several hours and/or within several hundred meters of the discharge source. The
                accumulation of toxic trace metals and hydrocarbons in exposed shelf waters, due to periodic releases of water-
                based generic muds and cuttings, is unlikely, and the long-term degradation of the water column from such
                discharges is not a major concerns.
                    No oil spills greater than or equal to 1,000 bbl and greater than 50 and less than 1,000 bbI are assumed
                to occur and contact coastal and nearshore waters. Eighteen spills greater than 1 but less than or equal to 50
                bbI are assumed to result from OCS sale-related activities both in the coastal zone and from offshore. Of
                these, fewer than 10, associated with onshore support and vessel activities, are assumed to occur in coastal
                waters. Program-related spills will introduce oil into nearshore waters, creating elevated hydrocarbon levels
                (up to 100+,ug/1) within affected waters. Much of the oil will be dispersed throughout the water column over
                several days to weeks. In shallow areas, oil may become entrained in suspended particles and bottom
                sediments. Water uses would be affected for up to several weeks from proposed spills and then only near the
                source of slick.


                Conclusion


                     An identifiable change to the ambient concentration of one or more water quality parameters will be
                evident up to several hundred to 1,000 meters from the source and for a period lasting up to several weeks
                in duration in marine and coastal waters. Chronic, low-level pollution related to the proposal will occur
                throughoutthe 35-year life of the proposed action.

                (4) Impacts on Air Quality

                     This alternative will offer for lease all those unleased blocks in the proposed action, excluding the 73 blocks
                near biologically sensitive topographic features in the WPA.










                 IV468

                     The subsequent analysis is presented to provide insights to any modification in the environmental
                 protection provided under Alternative B, as compared with the estimated impacts of Alternative A. A
                 description of the air quality in the WPA is provided in Section III.A3., and descriptions of the potential
                 impact-producing factors are provided in Section IV.A, An analysis of the impacts of Alternative A is
                 presented in Section IV.D.2.a.(4). The reader may refer to these sections for more details of the resources,
                 impact-producing factors, and derived impacts.
                     The size of the area and the number of blocks available for lease under Alternative A is large. Because
                 73 blocks would be withheld from proposed Sale 141 if this alternative were adopted, it is sal.7e to assume that
                 activities, infrastructure, and other factors described in that analysis will not change appreciably. The reader
                 may consult Table IV-3 for the number of wells and platforms related to Alternative A It is conceivable, given
                 the small size of the changes produced by Alternative B, that the analyses described in Alternative A will not
                 be changed.
                     The proposed action projects that 210 exploration and delineation wells and 110 development wells will
                 be drifted, and 10 platforms will be emplaced. The following table estimates emission rates for each subarea
                 during the life of the proposed action.

                                                      Total Emissions in )ATA Subareas
                                               (tons over the 35-year life of the proposed action)

                                     Pollutant              W-1                   W-2                 W-3


                                        NO,,                2,313.6            4,627.2            16,195.2
                                        CO                    351.2              702.5             2,458.7
                                        so,,                   62.0              124.0               434.1
                                        THC                   713.2            1,426.4             4,992.5
                                        TSP                    60.6              121.1               423.9

                     The discussion of the meteorology and pollutant dispersion presented under Alternative A indicates that
                 the release of pollutants over the Gulf waters occurs relatively close to the surface (30 m) and that prevailing
                 atmospheric conditions will promote vertical and horizontal mixing of the plume, in general. 'During night and
                 morning hours and in the winter, even though turbulence is available, the mixing height would be low, so that
                 little dilution would occur. During summer, the available turbulent energy and the greater mixing heights win
                 allow greater dispersion and dilution of pollutants. During high-wind conditions, the dispersion will be much
                 larger, reducing the concentrations to even lower levels. The only pollutant that may remain in large
                 concentrations is NOx.
                     More important are the potential impacts of these emissions on the inshore air quality. It is reasonable
                 to expect that emissions reaching land will be minimal from Subareas W-2 and W-3. Emissions carried inshore
                 from the subarea close to land, W-1, will arrive with small concentrations due to the intensive mixing over the
                 Gulf waters. At the coastline, the impacts then will depend on the level of concentration of the arriving
                 pollutant. Most will have low concentrations when arriving onshore. For NOx, however, the concentrations
                 may not be low. Numerical modeling by MMS of pollutant transport to inshore areas reveals that inert
                 pollutants have low concentrations when reaching inshore.
                     Oil spills of all categories will produce temporal impacts on the offshore air quality and are limited to the
                 immediate vicinity of the spill. Impacts to inshore areas from these spills are small because of the dispersion
                 of pollutants and the limited input of pollutants to the atmosphere.
                     Offloading of crude oil from surface vessels at ports is estimated to be nearly 19 percent of the OCS
                 production. The emission rates from these operations are small; thus, these unintentional emissions are
                 estimated to be negligible in the WPA Emissions from the tugboats in these operations are expected to
                 produce negligible effects on air quality.
                     Suspended particulate matter is important because of its potential in degrading the visibility in national
                 wildlife parks or recreational parks designated as Type I areas. Particles larger than 10 microns would have
                 very low concentrations because they settle fast. Particles of 10 microns or less remain floating for long










                                                                                                                            IV-469

               periods, but they produce a low impact on the visibility of these areas because of their low concentrations. The
               selection of Alternative B can diminish impacts on air quality from the above impact-producing factors, but not
               enough to change the level of the estimated impacts under Alternative A.

               Conclusion

                    Emissions of pollutants into the atmosphere from activities for the proposed action are expected to have
               concentrations that would not change the onshore air quality classifications.               Increases in onshore
               concentrations of air pollutants are estimated to be about 1 jLgm-1 (box model steady concentrations). This
               concentration will have minimal impacts during winter because onshore winds occur only about 34 percent of
               the time, and maximum impacts in summer when onshore winds occur 85 percent of the time.

               (5) Impacts on Marine Mammals

               (a) Nonendangered and Nonthreatened Species

                    This section discusses the impact of the adoption of Alternative B, which excludes biologically sensitive
               offshore habitats, on nonendangered and nonthreatened cetaceans, including whales and dolphins. The level
               of activity associated with the alternative is the same as the summary of infrastructure and activity described
               for the Base Case in Table IV-3. The sources and severity of impacts for nonendangered and nonthreatened
               species in Alternative B are the same as those discussed for the Base Case (Section IV.13.2.a.(5)). The impacts
               include operational discharges, helicopter and vessel traffic, drilling operations, explosive platform removals,
               seismic surveys, and oil spills. The effects of these activities are estimated to be primarily nonlethal and the
               probability of an interaction is unlikely. Lethal effects are estimated only from oil spills greater than or equal
               to 1,000 bbl.


               Conclusion

                    The impact of Alternative B on nonendangered and nonthreatened marine mammals is expected to result
               in sublethal effects that occur periodically and result in short-term physiological or behavioral changes, as wen
               as some degree of avoidance of the impacted area(s).

               (b) Endangered and Threatened Species

                    This section discusses the impact of the adoption of Alternative B, which excludes biologically sensitive
               offshore habitats, on endangered and threatened cetaceans, includingwhales and dolphins. The level of activity
               associated with the alternative is the same as the summary of infrastructure and activity described for the Base
               Case in Table IV-3. The sources and severity of impacts for endangered and threatened cetaceans in
               Alternative B are the same as those discussed for the Base Case (Section IV.13.2.a.(5)). The impacts include
               operational discharges, helicopter and vessel traffic, drilling operations, explosive platform removals, seismic
               surveys, and oil spills. The effects of these activities are estimated to be primarily nonlethal and the probability
               of an interaction is unlikely. Lethal effects are estimated only from oil spills greater than or equal to 1,000 bbl.

               Conclusion

                    The impact of Alternative B on nonendangered and nonthreatened marine mammals is expected to result
               in sublethal effects that occur periodically and result in short-term physiological or behavioral changes, as well
               as some degree of avoidance of the impacted area(s).










                   IV470

                   (6) Impacts on Marine Turtles

                       This section discusses the impact of the adoption of Alternative B, which excludes bicilogically sensitive
                   offshore habitats, on marine turtles. The level of activity associated with the alternative is the same as the
                   summary of infrastructure and activity described for the Base Case in Table IV-3. The sources and severity
                   of impacts for endangered/threatened and nonendangered/nonthreatened species in this alternative are the
                   same as those discussed for the Base Case (Section IV.D.2.a.(6)). The impacts include indirect impacts from
                   anchoring, structure and pipeline placement, dredging, and operational discharges; and the direct impacts of
                   trash and debris, off spills and oil-spill cleanup, vessel traffic, and the explosive removal of offshore structures.
                   The effects of these activities are estimated to be primarily nonlethal and the probability of an interaction is
                   unlikely. Lethal effects are estimated only from oil spills greater than or equal to 1,000 bbl.

                   Conclusion


                       The impact of Alternative B on marine turtles is expected to result in sublethal effects that are chronic and
                   could result in persistent physiological or behavioral changes.

                   (7) Impacts on Coastal and Marine Birds

                   (a) Nonendangered and Nonthreatened Species

                       The Gulf of Mexico is populated by migrant and nonmigrant species of coastal and marine birds. This
                   broad category consists of four main groups: seabirds, waterfowl, wading birds, and shorebirds.
                       The sources and severity of impacts associated with this alternative to coastal and marine birds associated
                   with this alternative are those sale-related activities discussed for the Base Case (Table IV-3). As noted in
                   Section IV.D.2.a.(7) for the Base Case, effects that may result from this alternative include oil spills, disturbance
                   from OCS service-vessel and helicopter traffic near coastal areas, displacement from onshore pipeline landfalls
                   and facility construction near coastal areas, and entanglement and ingestion of offshore ofl- and gas-related
                   plastic debris.
                       It is estimated that the effects from the major impact-producing factors on coastal and marine birds are
                   negligible and of nominal occurrence. As a result, there will no perceivable disturbance to Gulf coastal and
                   marine birds.


                   Conclusion


                       The impact of Alternative B on nonendangered and nonthreatened coastal and marine birds is expected
                   to result in no discernible decline in a population or species, and no change in distribution and/or abundance
                   on a local or regional scale. Individuals experiencing sublethal effects will recover to predisturbance condition
                   in less than one generation.

                   (b) Endangered and Threatened Species

                       This section discusses the impact of the adoption of Alternative B, which excludes biologically sensitive
                   offshore habitats, on endangered and threatened coastal and marine birds, including the pipling plover, brown
                   pelican, bald eagle, and Arctic peregrine falcon.
                       The level of activity associated with the alternative is the same as the summary of infrastructure and activity
                   described for the Base Case in Table IV-3. The sources and severity of impacts in Alternative B for
                   endangered and threatened coastal and marine birds are the same as those discussed for the Base Case
                   (Section IV.D.2.a.(7)). The impacts include oil spills, OCS service-vessel and helicopter traffic, onshore pipeline
                   construction, and entanglement and ingestion of offshore oil- and gas-related plastic debris. The effects of










                                                                                                                            IV-471

                these activities are estimated to be primarily nonlethal and the probability of an interaction is unlikely. Lethal
                effects are estimated only from oil spills greater than or equal to 1,000 bbl.

                Conclusion

                    The impact of Alternative B on endangered and threatened coastal and marine birds is expected to result
                in no discernible decline in a population or species and no change in distribution and/or abundance on a local
                or regional scale. Individuals experiencing sublethal effects will recover to predisturbance condition in less than
                one generation.

                (8) Impacts on Commercial Fisheries

                    The sources and severity of impacts to commercial fisheries are the same in this alternative as those
                discussed for the Base Case (Table IV-3). As noted in Section IV.D.2.a.(8) for the Base Case, effects that
                may result from this alternative include emplacement of production platforms, underwater OCS obstructions,
                production platform removals, seismic surveys, oil spills, subsurface blowouts, and OCS discharges of drilling
                muds.
                    It is estimated that the effects from the major impact-producing factors on commercial fisheries in the
                WPA are negligible and of nominal occurrence. As a result, there will be no perceivable disturbance to Gulf
                commercial fisheries.


                Conclusion

                    The impact of Alternative B on commercial fisheries is expected to result in no discernible decrease in a
                population of commercial importance, its essential habitat, or in commercial fisheries on a local scale. Any
                affected population is expected to recover to predisturbance condition in less than one generation.

                (9) Impacts on Recreational Resources and Activities

                (a) Beach Use

                    The sources and severity of beach use impacts associated with the offering of Alternative B are the same
                as the sale-related activities discussed for the Base Case. As noted in Section IV.D.2.a.(9)(a) for the Base
                Case, effects that may result on beach use from this alternative include off spills and trash and debris.
                    No oil spills of 1,000 bbl or greater and a few spills greater than 1 and less than or equal to 50 bbI are
                assumed to occur and contact a major recreational beach in the WPA (Section IV.C.3.). There will also be
                the intermittent effect of litter or trash associated with sale-related OCS operations. Removing tracts
                associated with the protected biological features (noted far offshore on Visual No. 2) will have little or no
                incremental effect on the amount of oil or trash and debris assumed to impact Texas coastal beaches adversely.
                As in the proposal, a few oil spills greater than 1 and less than or equal to 50 bbl are assumed to affect
                portions of WPA beaches, however, with little disruption of recreational activities.

                Conclusion


                    Alternative B is expected to result in periodic loss of solid-waste items Rely to wash up on recreational
                beaches, which is expected to diminish enjoyment of some beach visits but is unlikely to affect the number or
                type of visits currently occurring on Texas beaches.










                  IV472

                  (b) Marine Fishing

                       The sources and severity of marine fishing impacts associated with the offering of Alternative B are the
                  same as the sale-related activities discussed for the Base Case. As noted in Section IV.13.2.a.(9)(b) for the Base
                  Case, effects that may result on marine fishing from this alternative include platform installations and removals
                  and oil spills. Offshore platforms attract fish and fishermen; explosive removal of platforms will kill or critically
                  injure closely associated sport fish at the time of detonation; and oil spills will tend to discourage fishing.
                       The platform complex expected to be installed and ultimately removed in coastal Subarea W-1 win most
                  likely be unaffected by this alternative, as all of the tract deletions associated with this alternative are in
                  offshore Subareas W-2 and W-3, which are too far from shore to have much effect on recreational fishing. A
                  few oil spills greater than 1 and less than or equal to 50 bbl being assumed (Section MCA), the impact on
                  marine recreational fishing from this pollution will be short term and minor.

                  Conclusion


                       One platform complex (2-3 structures) installed as a result of Alternative B within :30 mi of shore is
                  expected to attract fishermen and to improve fishing success in the immediate vicinity of the platform complex
                  for a period of about 20 years.

                  (10) Impacts on Archaeologicd Resources

                       A number of OCS-related factors may cause adverse impacts to archaeological resources. Damage to both
                  historic and prehistoric archaeological resources could be caused by the placement of drilling rigs, production
                  platforms, and pipelines; dredging; and anchoring. These activities could destroy artifacts or disrupt the
                  provenance and stratigraphic context of artifacts, sediments, and paleoindicators, from which the scientific value
                  of the archaeological resource is derived. Oil spills could contaminate site organics and destroy the ability to
                  date prehistoric sites by radiocarbon dating techniques. Ferromagnetic debris associated with OCS oil and gas
                  activities would tend to mask magnetic signatures of significant historic archaeological resources.
                  (a) Historic

                       The offering for lease of all WPA blocks, with the exception of the lease blocks near biologically sensitive
                  topographic features, would result in the deletion of six lease blocks considered to have a high probability for
                  the occurrence of historic archaeological resources. Given the small number of lease blocks involved, adoption
                  of the alternative will not change expected impacts from those discussed under the Base Case scenario (Section
                  IV.D.2.a.(10)).
                       Offshore development could result in an interaction between a drilling rig, a platform, a pipeline, dredging,
                  or anchors and an historic shipwreck. The result would be the loss of archaeological data on ship construction,
                  cargo, the social organization of the vessel's crew, and the concomitant loss of information on maritime culture
                  for the time period from which the ship dates.
                       Likely locations of archaeological sites on the OCS cannot be delineated without first conducting a remote-
                  sensing survey of the seabed and near-surface sediments. The location of any proposed activity within a lease
                  block that has a high probability for historic shipwrecks requires archaeological clearance prior to operations.
                  If the expanded database containing 159 shipwrecks in the entire Western Gulf OCS is considered, the
                  probability of an OCS activity contacting and damaging a shipwreck is fairly low. However, if an oil and gas
                  structure contacted an historic resource, significant or unique archaeological information could be lost. The
                  frequency of such an occurrence, however, is expected to be low. The limited number of blocks that would
                  be deleted if the alternative were adopted would not change the expected impacts from those found for the
                  Base Case.
                       The greatest impact to an historic archaeological resource as a result of the proposed action would result
                  from a contact between an OCS offshore activity (platform installation, drilling rig emplacement, dredging and










                                                                                                                           IV-473

                 pipeline projects) and an historic shipwreck. Deletion of the blocks near biologically sensitive topographic
                 features would not result in the deletion of any block considered to have a high probability for historic and/or
                 prehistoric archaeological resources.
                     Because of incomplete knowledge on the location of shipwrecks in the Gulf, an OCS activity could contact
                 a shipwreck. Although this occurrence is not probable, such an event would result in the disturbance or
                 destruction of significant or unique historic archaeological information. Other factors associated with the
                 proposed action are not expected to affect historic archaeological resources.

                 Conclusion

                     There is a very small possibility of an impact between OCS oil and gas activities and an historic shipwreck
                 or site. Should such an impact occur, significant or unique archaeological information could be lost.

                 (b) ftehistoric
                     Prehistoric sites anticipated to occur offshore in WPA waters include all types that occur onshore. The
                 baseline study for the Gulf of Mexico (CEI, 1977) identified distinct, high-probability geomorphic features for
                 the occurrence of prehistoric archaeological sites. Two possible prehistoric sites have been located in the
                 western portion of the CPA as a result of an MMS-funded study (CEI, 1986). These possible sites occurred
                 in association with the ancient Sabine River valley and were identified by coring within Sabine Area, Block 6.
                 While no prehistoric sites have been identified on the Federal OCS in the WPA, artifacts have been discovered
                 at McFaddin Beach, Texas, but these appear to have been transported from areas offshore (CEI, 1977).
                     Offshore development as a result of the proposed action could result in an interaction that could destroy
                 fragile artifacts or site features and could disturb artifact provenance and site stratigraphy. The limited amount
                 of impact to the seafloor throughout the WPA, coupled with the effectiveness of the archaeological survey and
                 resulting archaeological clearance, is sufficient to assume a low potential for interaction between an impact-
                 producing factor and a prehistoric archaeological site. The adoption of Alternative B will not change expected
                 impacts from those expected under the Base Case.
                     The survey and clearance provide a significant reduction in the potential for a damaging interaction
                 between an impact-producing factor and a prehistoric site.

                 Conclusion

                     There is a very small possibility of an impact between oil and gas activities and a prehistoric archaeological
                 site. Should such an impact occur, there would be damage to or loss of significant or unique archaeological
                 information.

                 (11) Impacts on Socioeconomic Conditions

                 (a) Populatior4 Labor, and Employment

                     Resource estimates and associated infrastructure for the proposed action in the Western Gulf, excluding
                 blocks near biologically sensitive topographic features, are not significantly different from those estimated for
                 the proposed action in the Base Case. Estimates include the drilling of 210 exploration and delineation wells,
                 the emplacement of 10 platform complexes, and the drilling of 110 development wells (Table IV-3). The
                 sources and severity of impacts to population, labor, and employment are, therefore, the same as those assessed
                 for Western Gulf Sale 143 in the Base Case. A total of approximately 24,000 person-years of employment
                 (direct, indirect, and induced) are required in the Central and Western Gulf coastal subareas in support of
                 Alternative B throughout its 35-year life. Peak annual changes in the population, labor, and employment of
                 all coastal subareas in the Central and Western Gulf resulting from Alternative B represent less than 1 percent
                 of the levels expected in absence of the proposal. The coastal communities of the Central Gulf are expected










                  IV474

                  to support over 72 percent of the total employment generated by the Western Gulf sale under this alternative.
                  Employment resulting from ofl-spill. clean-up activities is negligible. It is expected that employment demands
                  in support of this alternative will be met with the existing population and available labor force.

                  Conclusion


                      The impact of Alternative B in the Western Gulf on the population, labor, and employment of the counties
                  and parishes of the Central and Western Gulf coastal impact area is expected to be less than 1 percent of the
                  levels expected in the absence of the proposal.

                  (b) Public Services and Infrastructure

                      Impacts on public services and infrastructure would be related to dramatic increases or decreases in
                  population. No positive net migration into the coastal subareas of the Central and Western Gulf is expected
                  to occur as a result of Alternative B. It is expected that employment will occur from those currently employed
                  in the oil and gas industry as well as the unemployed and underemployed, and new employees already living
                  in the area. In addition, jobs created by the proposal would likely reduce the amount of migration out of the
                  coastal subareas when compared with scenarios without the proposal. It is expected that employees leaving
                  public service and infrastructure-related jobs could be replaced from the existing labor pool.

                  Conclusion


                      Population and employment impacts that result from the proposed action under Alternative B will not
                  result in disruptions to community infrastructure and public services beyond what is anticipated by in-place
                  planning and development agencies.

                  (c) Social Patterns

                      Impacts on social patterns would be related to dramatic changes in population and the disruption of
                  environmental resources, as well as conditions inherent to OCS-related employment (i.e., work scheduling and
                  rate of pay). No positive net migration into coastal subareas of the Central and Western Crulf is expected to
                  occur as a result of the proposal. It is expected that employment will occur from those currently employed in
                  the oil and gas industry, as well as the unemployed and underemployed, and new employees already living in
                  the area. It is expected that jobs created by the proposal would likely reduce the amount of out-migration
                  when compared to scenarios without the proposal. It is expected that minor displacement from traditional
                  occupations will occur as a result of Alternative B. This displacement will be mitigated, to some extent, by the
                  extended work schedule associated with OCS-related employment. The extended work schedule is expected
                  to have some deleterious effects on family life in pertinent, individual cases. ImpacLs caused by the
                  displacement of traditional occupations and relative wages are expected to occur to a minimal extent

                  Conclusion


                      Deleterious impacts on social patterns are expected to occur in some individual cases as a result of the
                  extended work schedule, displacement from traditional occupations, and relative wages.










                                                                                                                            IV-475

                 c. Impacts from Alternative C - The Proposed Action Excluding the Western Naval
                      Operations Area

                 Description of the Alternative

                      This alternative would delete about 340 lease blocks (approximately 1.7 million acres) in Western Naval
                 Operations Area located east of Corpus Christi, Texas (Figure 1-1). In late 1990, MMS and the Department
                 of Defense (DOD) agreed to the deferral of this area from Western Gulf lease Sale 135 (held in August 1991)
                 and proposed Western Gulf lease Sale 141 (scheduled for August 1992). It was also agreed that the deferral
                 would be subject to a two-year review period, after which a decision would be made to either continue the
                 deferral for another two years or move the area to another acceptable location. Consultation has begun
                 between DOD and MMS and negotiations are continuing regarding this deferral area. Since negotiations
                 regarding this matter are still ongoing, the deletion of this 340-block area is included in this EIS as a separate
                 alternative.


                 Effects of the Alternative

                      The resource estimates and the projected level of activity (Le., numbers of wells, platforms, vessel trips,
                 etc.) and amount of spills for the proposed action (Base Case, High Case, and Cumulative Scenario) would
                 remain unchanged as a result of adopting this alternative.
                      It is expected that the deletion of this area would not change the impacts for the various resources analyzed
                 under Alternative A, except for a potential reduction in impacts to fixed resources (i.e., deep-water benthic
                 communities and archaeological resources) that may occur within the deleted area. Any potential for OCS-
                 related impacts to fixed resources in this area would be eliminated if the area is not available for lease.

                 (1) Impacts on Sensitive Coastal Environments

                 (a) Coastal Banier Beaches

                      The activities that could affect barrier beaches under Alternative C include oil spills, pipeline
                 emplacements, dredging of new navigation channels, maintenance dredging and vessel usage of existing
                 navigation channels, and the construction of onshore facilities on barrier features. Alternative C does not
                 directly affect the severity of impacts expected from activities associated with OCS development because the
                 deleted offshore sensitive habitats are located at a distance offshore from coastal barriers.
                      One or two spills greater than 1 and less than 50 bbl will occur inshore and contact the landward side of
                 barrier beaches. These spills will contact about 2 kin of coast and will be cleaned without the removal of sand.
                 No oil will contact sand dune areas. The barrier features will not be affected by contact from these spills. No
                 pipeline landfalls, navigation channels, or new infrastructure construction projects are expected as a result of
                 Alternative C. Maintenance dredging of existing navigation channels cannot be attributed to Alternative C
                 because of the small percentage of vessel usage attributable to the alternative. No channel deepening projects
                 will occur in an area that could affect barrier landforms.


                 Conclusion

                      Alternative C is not expected to result in permanent alterations of barrier beach configuration, except in
                 localized areas downdrift from channels that have been dredged and deepened. The contribution to localized
                 erosion is expected to be less than one percent.










                 IV-476

                 (b) Wetlands

                     The activities that could affect wetlands under Alternative C include oil spills, pipeline emplacements,
                 dredging of new navigation channels, maintenance dredging and vessel usage of existing navigation channels,
                 and the construction of onshore facilities. Alternative C does not directly affect the severity of impacts
                 expected from activities associated with OCS development under the Base Case scenario because the deleted
                 offshore sensitive habitats are located at a distance offshore from coastal barrier habitats.
                     Several spills greater than 1 and less than or equal to 50 bbl will occur from onshore sources and contact
                 wetlands. These spills will result in short-term impacts to up to several hectares of WPA wetlands, involving
                 die-back of the above-ground vegetation. No accelerated erosion of wetland margins is expected as a result
                 of the spills. Oil terminals and barge traffic do not commonly occur in WPA areas that contain extensive
                 seagrass beds; no impacts from oil spills to these resources are therefore assumed to occur. No pipeline
                 landfalls, navigation channels, or new infrastructure construction projects are expected as a result of Alternative
                 C. Although no new waste disposal sites are projected to be built to accommodate OCS-grnerated wastes,
                 some seepage from existing sites could occur into nearby wetlands. Maintenance dredging of eAsting navigation
                 channels cannot be attributed to Alternative C because of the small percentage of vessel m;age that can be
                 attributed to the alternative. The deepening of one navigation channel to provide access for deeper draft
                 service vessels is projected to occur. This analysis assumes that the dredged material will be used to enhance
                 or create marsh habitat Alternative C will result in a reduction in resource development compared to
                 Alternative A. The amount of vessel traffic required under Alternative C for supply vessels, barges, and shuttle
                 tankers will be less than or equal to that required under the Base Case. Impacts of OCS vessel traffic on
                 wetlands along channel margins are expected to be result in less than 1 ha of accelerated wetland erosion.

                 Conclusion


                     Alternative C is expected to result in no permanent alterations of wetland habitats, except for the erosion
                 of less than 1 ha of wetlands along navigation channel margins. These losses could be offset or even exceeded
                 by wetlands gains from the beneficial disposal of dredged material generated during channel maintenance and
                 deepening operations.

                 (2) Impacts on Sensitive Offshore Resources

                 (a) Deep-water Benthic Communities

                     The sources and severity of impacts associated with this alternative are those sale-related activities
                 discussed for Alternative A. As noted in Section IV.13.2.a.(2)(a) for the Base Case analysis, the only impact-
                 producing factor threatening these communities results from those activities that would physically disturb the
                 bottom, such as the routine operations of anchoring, drilling, and pipeline installation, and the rare seafloor
                 blowout accident. A more detailed examination of this potential impact-producing factor is presented in that
                 section.
                     High-density chemosynthetic communities are found only in water depths greater than 4,00 m (1,312 ft);
                 thus, they will be found only in the southeast one-eighth of Subarea W-1, the southern one-third of W-2, and
                 throughout W-3. The majority of these communities will not be exposed to the full level of the projected
                 impact-producing factors of Table IV-3. This alternative differs from Alternative A by offering all of the blocks
                 of Alternative A except for approximately 340 blocks that comprise the Western Naval Operations Area
                 (Figure I-1). Of these blocks, all or part of 197 blocks are in water deeper than 400 m, and 6 of these are
                 under active lease. Thus, if Alternative C is adopted, those blocks would not be subject to the potential
                 impacts described for Alternative A (Section IV.13.2.a.(2)(a)). Not leasing these 191 unleased blocks (6% of
                 the 3,104 unleased blocks in the WPA in water deeper than 400 in) will not alter the conclusions reached in
                 the analysis for Alternative A.










                                                                                                                           IV-477

                    The majority of these deep-water communities are of low density and are widespread throughout the deep-
                water areas of the Gulf, and disturbance to a small area would not result in a major impact to the ecosystem.
                For purposes of this analysis, the frequency of such impact is expected to be once every six months to two
                years, and the severity of such an impact is judged to result in few losses of ecological elements with no
                alteration of general relationships.
                    High-density communities are largely protected by the provisions of NTL 88-11. For purposes of this
                analysis, the frequency of some small percentage of impact is expected to be once every six months to two
                years, but the severity of such an impact is such that there may be some loss of ecological elements and/or
                some alteration of general relationships.

                Conclusion


                    Alternative C is expected to cause little damage to the physical integrity, species diversity, or biological
                productivity of either the widespread, low-density chemosynthetic communities or the rare, widely scattered
                high-density Bush Hill-type chemosynthetic communities. Recovery from any damage is expected to take less
                than 2 years.

                (b) Topographic Features

                    The sources and severity of impacts associated with this alternative are those sale-related activities
                discussed for the Base Case. As noted in Section IV.13.2.a.(2)(b) for the Base Case, the potential impact-
                producing factors to the topographic features of the Western Gulf are anchoring and structure emplacement,
                effluent discharge, blowouts, oil spills, and structure removal. A more detailed examination of these potential
                impact-producing factors is presented in that section.
                    Eleven of the 23 topographic features of the Western Gulf are located in Subarea W-1; 12 are in W-2 (in
                both cases they occupy a very small portion of the entire area); therefore, these communities will not be
                exposed to the full level of the projected impact-producing factors assumed under Alternative A- This
                alternative differs from Alternative A by offering all of the blocks of Alternative A except for approximately
                340 blocks that comprise the Western Naval Operations Area (Figure 1-1). None of the topographic features
                of the Western Gulf are located within these 340 blocks. Thus, the topographic features of the Western Gulf
                would be subject to all of the potential impacts described for Alternative A (Section IV.13.2.a.(2)(b)).

                Conclusion


                    Alternative C is expected to cause little to no damage to the physical integrity, species diversity, or
                biological productivity of the habitats of the topographic features of the Gulf of Mexico. Small areas of 5-10
                M2  would be impacted, and recovery from this damage to pre-impact conditions is expected to take less than
                2 years, probably on the order of 2-4 weeks.

                (3) Impacts on Water Qua1hy

                    All existing onshore infrastructure and associated coastal activities occurring in support of Alternative C
                will contribute to the degradation of regional coastal and nearshore water quality to a minor extent because
                each provides a low measure of continuous contamination and because discharge locations are widespread. The
                OCS-related vessel traffic is likely to impact water quality through routine releases of bilge and ballast waters,
                chronic fuel and tank spills, trash, and low-level releases of the contaminants in antifouling paints. It is
                therefore assumed that there will be some localized short-term change (up to several weeks) in water quality
                characteristics from background levels, depending on the length of the affected channel, flushing rates, etc.
                The improper storage and disposal of oil-field wastes and NORM-contaminated oil-field equipment would
                adversely impact surface and groundwaters in proximity to State permitted disposal facilities, cleaning sites, and
                scrap yards. As a result of site runoff, surface and groundwater in proximity to improperly designed and










                 IV-478

                 maintained storage/disposal sites and facilities could be adversely impacted with elevated concentrations of
                 arsenic, chromium, zinc, cadmium, mercury, lead, barium, penta-chlorophenol, naphthalene, benzene, toluene,
                 and radium.
                     Immediate effects would be brought about by increased drilling, construction, and pip-.laying activities,
                 causing an increase in water column turbidities (lasting for several hours for mud discharges to several weeks
                 for pipelaying/dredging activities) to the affected offshore waters. Offshore Subarea W-1 would receive the
                 greatest portion of program-related pipeline burial activities, whereas offshore Subarea W-3 would receive the
                 largest amounts of program-related operational discharges. Proposed produced-water discharges will be rapidly
                 diluted within the immediate vicinity of the discharge source. Significant increases in water concentrations of
                 dissolved and particulate hydrocarbons and trace metals are not expected outside the initial mixing zone or
                 immediate vicinity of the discharge source. Higher concentrations of trace metals, salinity, temperature, organic
                 compounds, and radionuclides, and lower dissolved oxygen may be present near the discharge source. Long-
                 term effects to water column processes, consisting of localized increases in particulate metal and soluble lower
                 molecular weight hydrocarbons (e.g., benzene, toluene, and xylenes) concentrations, may be implicated within
                 the mixing zone of the discharge. Trace metals and hydrocarbons associated with the discharge may be
                 deposited within sediments near the discharge point The proposed discharge of drilling fluids and cuttings
                 would encounter rapid dispersion in marine waters. Discharge plumes will be diluted to background levels
                 within a period of several hours and/or within several hundred meters of the discharge source. The
                 accumulation of toxic trace metals and hydrocarbons in exposed shelf waters, due to periodic releases of water-
                 based generic muds and cuttings, are unlikely and the long-term degradation of the water column from such
                 discharges are not a major concern.
                     Eighteen spills greater than 1 but less than or equal to 50 bbl are assumed to result from OCS sale-related
                 activities both in the coastal zone and from offshore. Of these, fewer than 10, associated with onshore support
                 and vessel activities, are assumed to occur in coastal waters. Program-related spills will introduce oil into
                 nearshore waters, creating elevated hydrocarbon levels (up to 100+ Ag1l) within affected waters. Afterl0days,
                 much of the oil will be dispersed throughout the water column over a period of weeks. In shallow areas, oil
                 may become entrained in suspended particles and bottom sediments. Water uses would be affected for up to
                 several weeks from proposed spills and then only near the source of the slick.

                 Conclusion


                     As a result of Alternative C, an identifiable change to the ambient concentration of one or more water
                 quality parameters will be evident up to several hundred to 1,000 m from the source and for a period lasting
                 up to several weeks in duration in marine and coastal waters. Chronic, low-level pollution related to the
                 proposal will occur throughout the life of the proposed action.

                 (4) Impacts on Air Quality

                     The size of the area and the number of blocks available for lease under Alternative A is large. Because
                 340 blocks would be withheld from proposed Sale 143 if this alternative were adopted, it is assumed that
                 activities, infrastructure, and other factors described in that analysis will not change appreciably. The reader
                 may consult Table IV-3 for the number of wells and platforms related to Alternative A. It is conceivable, given
                 the small size of the changes produced by Alternative C, that the analyses described in Alternative A will not
                 be changed.
                     The only pollutant that may retain large concentrations is NOx. It is expected that, in general,
                 concentrations will be very low for pollutants other than NOx over the Gulf waters. Duringstable conditions
                 over the Gulf waters, concentrations can reach moderate values. It is reasonable to expect that emissions
                 reaching land will be minimal from Subareas W-2 and W-3. Emissions carried inshore from the subarea close
                 to land, W-1, will arrive with small concentrations due to the intensive mixing over the Gulf waters. At the
                 coastline, the impacts will depend on how low the concentrations are upon arrival. Numerical modeling by










                                                                                                                           IV-479

                MMS of pollutant transport to inshore areas reveals that inert pollutants have very low concentrations when
                reaching inshore areas.
                    Oil spills of all categories will produce temporal impacts on the offshore air quality and are limited to the
                immediate vicinity of the spill. Impacts to inshore areas from these spills are small because the dispersion of
                pollutants and their limited input of pollutants to the atmosphere.
                    Offloading of crude oil from surface vessels at ports is estimated to be near 19 percent of the OCS
                production. The emission rates from these operations are small; thus, these unintentional emissions are
                estimated to be negligible in the WPA. Emissions from tugboats in these operations are expected to produce
                negligible effects on air quality.
                    Suspended particulate matter is important because of its potential in degrading the visibility in national
                wildlife parks or recreational parks designated as Type I areas. Particles larger than 10 microns would have
                very low concentrations because they settle fast. Particles of 10 microns or less remain floating for long
                periods, but they have low concentrations. The selection of Alternative C can diminish impacts on air quality
                from the above impact-producing factors but not enough to change the level of the estimated impacts under
                Alternative A.


                Conclusion

                    Emissions of pollutants into the atmosphere are expected to have concentrations that would not change
                the onshore air quality classifications. Increases in onshore concentrations of air pollutants are estimated to
                be about I pgm-3 (box model steady concentrations). This concentration will have minimal impacts during
                winter because onshore winds occur only about 34 percent of the time, with maximum impacts in summer when
                onshore winds occur 85 percent of the time.

                (5) Impacts on Marine Mammals

                (a) Nonendangered and Nonthreatened Species

                    The level of activity associated with the alternative is the same as the summary of infrastructure and activity
                described for Alternative A (Table IV-3). The sources and severity of impacts for nonendangered and
                nonthreatened species in Alternative C are the same as those discussed for Alternative A (Section
                IV.13.2.a.(5)). The impacts include operational discharges, helicopter and vessel traffic, drilling operations,
                explosive platform removals, seismic surveys, and oil spills. The effects of these activities are estimated to be
                primarily nonlethal, and the probability of an interaction is unlikely. Lethal effects are estimated only from
                oil spills greater than or equal to 1,000 bbl.

                Conclusion

                    The impact of Alternative C on the nonendangered and nonthreatened marine mammals is expected to
                result in sublethal effects that occur periodically and result in short-term physiological or behavioral changes,
                as well as some degree of avoidance of the impacted area(s).

                (b) Endangered and nreatened Species

                    The level of activity associated with the alternative is the same as the summary of infrastructure and activity
                described for Alternative A (Table IV-3). The sources and severity of impacts for endangered and threatened
                species in Alternative C are the same as those discussed for Alternative A (Section IV.13.2.a.(5)). The impacts
                include operational discharges, helicopter and vessel traffic, drilling operations, explosive platform removals,
                seismic surveys, and oil spills. The effects of these activities are estimated to be primarily nonlethal, and the
                probability of an interaction is unlikely. Lethal effects are estimated only from oil spills greater than or equal
                to 1,000 bbl.









                  IV4W

                  Conclusion

                      The impact of Alternative C on the endangered and threatened marine mammals is expected to result in
                  sublethal effects that occur periodically and result in short-term physiological or behavioral changes, as wen
                  as some degree of avoidance of the impacted area(s).

                  (6) Impacts on Marine Turties

                      The level of activity associated with the alternative is the same as the summary of infrastructure and activity
                  described for Alternative A (Table IV-3). The sources and severity of impacts for endangered/threatened and
                  nonendangered/nonthreatenedspecies in this alternative are the same as those discussed :for Alternative A
                  (Section IV.D.2.a.(6)). The impacts include indirect impacts from anchoring, structure and pipeline placement,
                  dredging, and operational discharges; and direct impacts from trash and debris, oil spills and oil-spill cleanup,
                  vessel traffic, and the explosive removal of offshore structures. The effects of these activities, are estimated to
                  be primarily nonlethal, and the probability of an interaction is unlikely. Lethal effects are estimated only from
                  oil spills greater than or equal to 1,000 bbl.

                  Conclusion


                      The impact of Alternative C on marine turtles is expected to result in sublethal effects that are chronic and
                  could result in persistent physiological or behavioral changes.

                  (7) Impacts on Coastal and Marine Birds

                  (a) Nonendangered and Nonthreatened Species

                      The sources and severity of impacts to coastal and marine birds associated with this alternative are those
                  sale-related activities discussed for Alternative A (Table IV-3). As noted in Section IV.D.2.a.(7) for Alternative
                  A, effects that may result from this alternative include oil spills, disturbance from OCS service-vessel and
                  helicopter traffic near coastal areas, displacement from onshore pipeline landfalls, facility construction near
                  coastal areas, and entanglement in and ingestion of offshore oil- and gas-related plastic debris.
                      It is estimated that the effects from the major impact-producing factors on coastal and marine birds are
                  negligible and of nominal occurrence. As a result, there will no perceivable disturbance to Gulf coastal and
                  marine birds.


                  Conclusion

                     The impact of Alternative C on nonendangered and nonthreatened coastal and marine birds is expected
                  to result in no discernible decline in a population or species, and no change in distribution and/or abundance
                  on a local Or regional scale. Individuals experiencing sublethal effects will recover to pre-disturbance condition
                  in less than one generation.

                  (b) Endangered and Threatened Species

                     The level of activity associated with the alternative is the same as the summary of infrastructure and activity
                  described for Alternative A (Table IV-3). The sources and severity of impacts for endangered and threatened
                  coastal and marine birds in Alternative C are the same as those discussed for Alternative A (Section
                  IV.D.2.a.(7)). The impacts include oil spills, OCS service-vessel and helicopter traffic, onshore pipeline
                  construction, and entanglement in and ingestion of offshore oil- and gas-related plastic debris. The effects of
                  these activities are estimated to be primarily nonlethal, and the probability of an interaction is unlikely. Lethal
                  effects are estimated only from oil spills greater than or equal to 1,000 bbl.










                                                                                                                               IV-481


                   Conclusion

                       The impact of Alternative C on endangered and threatened coastal and marine birds is expected to result
                   in no discernible decline in a population or species, and no change in distribution and/or abundance on a local
                   or regional scale. Individuals experiencing sublethal effects will recover to pre-disturbance condition in less
                   than one generation.

                   (8) Impacts on Commercial Fisheries

                       The sources and severity of impacts to commercial fisheries in this alternative are the same as those
                   discussed for Alternative A (Table IV-3). As noted in Section IV.D.2.a.(8) for Alternative A, effects that may
                   result from this alternative include emplacement of production platforms, underwater OCS obstructions,
                   production platform removals, seismic surveys, oil spills, subsurface blowouts, and OCS discharges of drilling
                   muds.
                       It is estimated that the effects from the major impact-producing factors on commercial fisheries in the
                   WPA are negligible and of nominal occurrence. As a result, there will be no perceivable disturbance to Gulf
                   commercial fisheries.


                   Conclusion

                       The impact of Alternative C on commercial fisheries is expected to result in no discernible decrease in a
                   population of commercial importance, in an essential habitat, or in commercial fisheries on a local scale. Any
                   affected population is expected to recover to pre-disturbance conditions in less than one generation.

                   (9) Impacts on Recreational Resources and Activities

                   (a) Beach Use

                       The sources and severity of beach use impacts associated with the offering of Alternative C are the same
                   as the sale-related activities discussed for Alternative A. As noted in Section IV.D.2.a.(9)(a) for Alternative
                   A, effects that may result on beach use from this alternative include oil spins and trash and debris.
                       No off spills greater than or equal to 1,000 bbl and a few spills greater than 1 and less than or equal to 1-50
                   bbl are assumed to occur and contact a major recreational beach in the WPA (Section IV.C.3.). There will
                   also be the intermittent effect of litter or trash associated with sale-related OCS operations. Removing tracts
                   associated with the protected biological features (noted far offshore on Visual No. 2) will have little or no
                   incremental effect on the amount of oil or trash and debris assumed to impact Texas coastal beaches adversely.
                   As in the proposal, a few oil spills greater than 1 and less than or equal to 50 bbI are assumed to affect
                   portions of WPA beaches; however, there will be little disruption of recreational activities.

                   Conclusion

                       The periodic loss of solid-waste items likely to wash up on recreational beaches is expected to diminish the
                   enjoyment of some beach sites, but it is unlikely to affect the number or type of visits currently occurring on
                   Texas beaches.

                   (b) Matine Fishing

                       The sources and severity of marine fishing impacts associated with the offering of Alternative C are the
                   same as the sale-related activities discussed for the Alternative A. As noted in Section IV.D.2.a.(9)(b) for
                   Alternative A, effects that may result on marine fishing from this alternative include platform installations and
                   removals and oil spills. Offshore platforms attract fish and fishermen; explosive removal of platforms will kill










                IV-482

                or critically injure closely associated sport fish at the time of detonation; and oil spills will tend to discourage
                fishing.
                    The platform complex expected to be installed and ultimately removed in coastal Subarea W-1 win most
                likely be unaffected by this alternative, as all of the tract deletions associated with this alternative are in
                offshore Subareas W-2 and W-3, which are too far from shore to have much effect on recreational fishing.
                Given that a few oil spills greater than 1 and less than or equal to 50 bbl are assumed (Section IV.C.1), the
                impact on marine recreational fishing from this pollution win be short term and minor.

                Conclusion

                    One new platform complex (2-3 structures) installed as a result of this proposal (within 30 mi of shore)
                is expected to attract fishermen and to improve fishing success in the immediate vicinity of the platform, lasting
                for a period of about 20 years.

                (10) Impacts on Archaeological Resources

                (a) Historic

                    The offering for lease of all WPA blocks, with the exception of 340 lease blocks offshore Corpus Christi,
                Texas, would result in the deletion of 12 lease blocks considered to have a high probability for the occurrence
                of historic archaeological resources. Given the number of lease blocks involved, adoption ofthe alternative
                will not change expected impacts from those discussed under Alternative A (Section IV.13.2.a.(10)).
                   Offshore development could result in an interaction between an historic shipwreck, and a drilling rig,
                platform, pipeline, dredging, or anchor. The result would be the loss of archaeological data on ship
                construction, cargo, the social organization of the vessel's crew, and the concomitant loss of information on
                maritime culture for the time period from which the ship dates. The probability of an OCS activity contacting
                and damaging a shipwreck is very low. However, if an oil and gas structure contacted an historic resource,
                significant or unique archaeological information could be lost. The frequency of such an occurrence, however,
                is expected to be low. The limited number of blocks that would be deleted if the alternative were adopted
                would not change the expected impacts from those found for Alternative A- The greatest impact to an historic
                archaeological resource as a result of the proposed action would result from a contact between an OCS
                offshore activity (platform installation, drilling rig emplacement, dredging and pipeline projects) and an historic
                shipwreck.
                   Because of incomplete knowledge on the location of shipwrecks in the Gulf, an OCS activity could contact
                a shipwreck. Although this occurrence is not probable, such an event would result in the disturbance or
                destruction of significant or unique historic archaeological information. Other factors associated with the
                proposed action are not expected to affect historic archaeological resources.

                Conclusion

                   There is a very small possibility of an impact between OCS oil and gas activities and an historic shipwreck
                or site. Should such an impact occur, significant or unique archaeological information could be lost.
                (b) Prehistoric

                   While no prehistoric sites have been identified on the Federal OCS in the WPA, artifacts have been
                discovered at McFaddin Beach, Texas, but these appear to have been transported from areas offshore (CEI,
                1977). Offshore development as a result of the proposed action could result in an interaction that could
                destroy fragile artifacts or site features and could disturb artifact provenance and site stratigraphy. The limited
                amount of impact to the seafloor throughout the WPA, coupled with the effectiveness of the archaeological
                survey and resulting archaeological clearance, is sufficient to assume a low potential for interaction between











                                                                                                                          IV-483

               an impact-producing factor and a prehistoric archaeological site. The adoption of Alternative C will not change
               expected impacts from those expected under Alternative A, since the area of deferral is outside the prehistoric
               high-probability area. The survey and clearance provide a significant reduction in the potential for a damaging
               interaction between an impact-producing factor and a prehistoric site.

               Conclusion

                   There is a very small possibility of an impact between oil and gas activities and a prehistoric archaeological
               site. Should such an impact occur, there would be damage to or loss of significant or unique archaeological
               information.

               (11) Impaca on Socioeconomic Conditions

               (a) Population, Labor, and Employment

                   Resource estimates and associated infrastructure for the proposed action in the Western Gulf, excluding
               340 blocks offshore Corpus Christi@ Texas, are not significantly different from those estimated for the proposed
               action in Alternative A. The sources and severity of impacts to population, labor, and employment are,
               therefore, the same as those assessed for Western Gulf Sale 143 in Alternative A. A total of approximately
               24,000 person-years of employment (direct, indirect, and induced) are required in the Central and Western Gulf
               coastal subareas in support of Alternative C throughout its 35-year life. Peak annual changes in the population,
               labor, and employment of all coastal subareas in the Central and Western Gulf resulting from Alternative C
               represent less than 1 percent of the levels expected in absence of the proposal. The coastal communities of
               the Central Gulf are expected to support over 72 percent of the total employment generated by the Western
               Gulf sale under this alternative. Employment resulting from oil-spill clean-up activities is negligible. It is
               expected that employment demands in support of this alternative will be met with the existing population and
               available labor force.


               Conclusion

                   The impact of Alternative C on the population, labor, and employment of the counties and parishes of the
               Central and Western Gulf coastal impact area is expected to be less than 1 percent of the levels expected in
               the absence of the proposal.

               (b) Public Services and Infrastructure

                   Impacts on public services and infrastructure would be related to dramatic increases or decreases in
               population. No positive net migration into the coastal subareas of the Central and Western Gulf is expected
               to occur as a result of Alternative C. It is expected that employment will occur from those currently employed
               in the oil and gas industry, as well as the unemployed and underemployed and the new employees already living
               in the area. In addition, jobs created by the proposal would likely reduce the amount of migration out of the
               coastal subareas when compared with scenarios without the proposal. It is expected that employees leaving
               public service and infrastructure-related jobs could be replaced from the existing labor pool.

               Conclusion

                   Population and employment impacts that result from the proposed action under Alternative C will not
               result in disruptions to community infrastructure and public services beyond what is anticipated by in-place
               planning and development agencies.











                 IV-494

                 (c) Social Pauerm

                     Impacts on social patterns would be related to dramatic changes in population and the disruption of
                 environmental resources, as well as conditions inherent to OCS-related employment (i.e., work scheduling and
                 rate of pay). No positive net migration into coastal subareas of the Central and Western Gulf is expected to
                 occur as a result of the proposal. It is expected that employment will occur from those currently employed in
                 the off and gas industry, as well as the unemployed and underemployed and the new employees already living
                 in the area. It is expected that jobs created by the proposal would likely reduce the amount. of out-migration
                 when compared to scenarios without the proposal. It is expected that minor displacement from traditional
                 occupations will occur as a result of Alternative C. This displacement will be mitigated, to some extent, by the
                 extended work schedule associated with OCS-related employment. The extended work schedule is expected
                 to have some deleterious effects on family life in pertinent, individual cases. Impacts caused by the
                 displacement of traditional occupations and relative wages are expected to occur to a minimal extent.

                 Conclusion


                     Deleterious impacts on social patterns are expected to occur in some individual cases as a result of the
                 extended work schedule, displacement from traditional occupations, and relative wages.

                 d. Impacts from Alternative D - No Action

                 Description of the Alternative

                     Alternative D is equivalent to cancellation of a sale projected for a specific timefrarne. Sales in the
                 Western Gulf are scheduled on an annual basis. By canceling the proposed sale, the opportunity is postponed
                 or foregone for development of the estimated 0.05 BBO and 0.74 tcf of gas that could have resulted from
                 proposed Sale 143 in the Western Gulf.

                 Effects of the Alternative

                     If Alternative D is selected, all impacts, positive and negative, associated with the proposed action would
                 be canceled. This alternative would, therefore, result in no effect on the sensitive resources and activities
                 discussed in Section IV.D.2.a. The incremental contributionof the proposed action to cumulative effects would
                 also be foregone, but such effects from other activities, including other OCS sales, would remain. One
                 contribution to cumulative effects that could increase is oil-spill risk due to the importation. of foreign oil to
                 replace the resources lost through cancellation of the proposed action.
                     Alternative energy strategies that could provide replacement resources for lost domestic OCS oil and gas
                 production include energy conservation; conventional oil and gas supplies; coal; nuclear power; oil shale; tar
                 sands; hydroelectric power; solar and geothermal energy; and imports of oil, natural gas, and LNG. These are
                 discussed in some detail in Appendix D. A National Energy Strategy is under development by the DOE, and
                 their interim report was published April 2, 1990. The energy equivalents that may be required from several
                 alternative energy sources, should this lease sale be permanently canceled, are shown on Table D-8 and are
                 based on the resources estimated by MMS to be produced as a result of the proposed action. For the purpose
                 of clarity, this table has separately identified each potential alternative source of energy regarding substitution
                 requirements. It is unlikely, however, that there would be a single choice between these alternatives sources,
                 but instead, some combined effort to explore and develop further many or all of these forms as a substitute
                 for OCS oil and gas production.










                                                                                                                                IV-485

                 e. Impacts of Cumulative Actions

                     This section analyzes "cumulative"actions, defined as other past, present, and reasonably foreseeable future
                 actions, both Federal and nonfederal (40 CFR 1508.7) that when added with actions resulting from the
                 proposed actions result in an incremental impact to the resources of concern. The time period that these
                 future impacts are examined is limited to the time of the proposed actions (1993-2027), and the resources
                 analyzed are those identified as potentially being impacted from the proposed actions. Cumulative impacts
                 can result from individually minor but collectively significant actions taking place over a period of time. See
                 Section IV.B. for details regarding the cumulative scenario and assumptions on which the following analyses
                 are based.


                 (1) Impacts on Sensitive Coastal Environments

                 (a) Coastal Banier Beaches

                     This Cumulative Analysis considers the effects of impact-producing factors related to the proposed action,
                 plus those related to the Central Gulf proposed action, prior and future OCS sales, State oil and gas activities,
                 other governmental and private projects and activities, and pertinent natural processes that may affect barrier
                 features.
                     Specific impact-producing factors considered in the Cumulative Analysis include sediment reduction,
                 pipeline landfalls, navigation canal and onshore facility construction, oil spills, beach protection and stabilization
                 projects, and recreational activities.
                     Reductions in sediment supply along the Texas coast will continue to have a significant impact on barrier
                 landforms.     Dam construction on coastal rivers upstream has trapped sand-size sediments.                       The
                 compartmentalization of the coast with groins and jetties has trapped sediment on the updrift sides of the
                 structures. Seawall construction along eroding stretches of islands has reduced the amount of sediment
                 introduced into the littoral system as a result of shore erosion. In addition, the Texas coast has experienced
                 a natural decrease in sediment supply as a result of climatic changes that have occurred during the past few
                 thousand years (Morton, 1982). In addition, the eastern part of the affected area is influenced by the sediment
                 discharge of the Mississippi River, which has decreased by over 50 percent since the 1950's (Turner and
                 Cahoon, 1987).
                      Oil spill contacts to barrier landforms can occur from a number of sources. The effects of oil spills to
                 barrier features under the Cumulative scenario will be evaluated for OCS Program spins and for
                 imported/onshore crude and petroleum products spills. Spills from offshore and onshore sources will be
                 considered.
                     No spills greater than 1 and less than or equal to 50 bbl or spills greater than 50 and less than 1,000 bbl
                 are assumed to occur offshore and contact barrier features as a result of OCS Program activities. The offshore
                 occurrence of seven spills greater than or equal to 1,000 bbl is assumed to occur as a result of OCS Program
                 activities. According to Table IV-22, the probability of occurrence and contact within 10 days from these spills
                 ranges from 12 percent along the Chenier Plain coast in Louisiana to less than 0.5 percent along the Padre
                 Island barriers. Spill contacts that occur along the Louisiana coast as a result of OCS Program activities have
                 been discussed and analyzed in Section IV.D.l.a.(I)(a) and will not be covered here. Based on the probabilities
                 in Table IV-22, this analysis assumes no contacts will occur along the Texas coast.
                     Onshore spills could also occur from OCS operations and contact coastal barriers. These spills could occur
                 as a result of pipeline accidents and barge or shuttle tanker accidents during transit or offloading. Most oil
                 terminals are located on the back side of or inland from barrier islands, so an accident there would either not
                 likely result in contact to a barrier feature or would contact mainly the back side of the island. A barge or
                 shuttle tanker accident in transit could occur as the vessel approached or was travelling through a barrier pass
                 or while the vessel was traveling through the Intracoastal Waterway after entering coastal waters and making
                 the final approach to the terminal. Under this scenario, it is assumed that a spill will contact the lagoonal,
                 rather than the ocean side, of a barrier beach.










                 IV486

                      This analysis assumes that about six spills greater than I and less than or equal to 50 bbl, one spill greater
                 than 50 and less than 1,000 bbl, and one spill greater than or equal to 1,000 bbl will occur onshore as a result
                 of OCS Program activities. The assumption, based on an analysis of historic spill locations, which have been
                 concentrated in the Galveston-Houston area, is assumed that two contacts to barrier land forms will occur,
                 resulting in 10-50 km of back barrier coast contacted. Because of the low-energy environment of this setting,
                 cleanup will be accomplished without erosion or alteration of the island configuration.
                      Non-OCS spills can occur as a result of import tankers, tidelands oil activities, and petroleum productspills.
                 It is assumed that numerous spills greater than I and less than or equal to 50 bbl and greater than 50 and less
                 than 1,000 bbl will occur and contact the ocean and land sides of barrier islands. Most of these spills will result
                 in only small amounts of offing. Eighty crude oil and product spills greater than or equal to 1,000 bbl,
                 averaging 7,000 bbl each, are assumed to occur during the life of the proposed action from offshore and
                 onshore sources. Numerous contacts to barrier beaches are assumed. Because of the heavy and frequent
                 oilings of beaches in this scenario, it is assumed that cleanup operations will disturb and remove some sand,
                 which could result in short-term (up to two years) adjustments in beach configuration if the sand is not replaced
                 and regraded as a mitigation measure. It is assumed that about 50 km of beach will be contacted by each spill.
                      As discussed in Section IV.D. La.(l)(a), the probability that tide levels could reach or exceed the elevations
                 of sand dune vegetation on barrier beaches ranges from 0 to 16 percent, depending on the particular coastal
                 setting and the elevation of the vegetation. Given the higher frequency of spill occurrence and the heavier
                 oilings from onshore spills greater than or equal to 1,000 bbl, it is assumed that the lower e[evations of some
                 sand dune vegetation will be contacted. Considering the results of an investigation of the effects of the disposal
                 of offed sand on dune vegetation in Texas, which disposal showed no deleterious impacts on existing vegetation
                 or colonization of the sand by new vegetation (Webb, 1988), it is assumed that contacts to small areas of lower
                 elevated sand dunes will not result in destabilization of the sand dune area or the barrier landform.
                      An area of special concern along the South Texas coast is the Padre Island National Seashore. This area
                 is not assumed to be contacted by an oil spill because of the limited opportunities for a spill to occur near the
                 National Seashore. No off pipeline landfalls occur in the vicinity of these islands; no oil has been developed
                 in the OCS areas offshore from the seashore. The closest oil port and terminal facilities are near Corpus
                 Christi, located about 20 kin to the north of the northern edge of the seashore. Furthermore, a spill that
                 occurs in the Corpus Christi area is assumed to occur within the protected waters of Corpus Christi Bay, and
                 oil is assumed to be introduced into the coastal current system and be carried directly to the Padre Island area.
                      Pipeline landfalls have been identified as possible causes of impacts to barrier landforms. A recently
                 completed MMS study, Pipelines, Navigation Channels and Facilities in Sensitive Coastal Habitats: An Ana4wis
                 of Impacts, Coastal Gulf of Mexico (Wicker et al., 1989), investigated pipeline emplacement finpacts on barrier
                 landforms along the Texas coast. After studying numerous landfalls within the Texas barrier island system and
                 nearby areas of coastal Louisiana, they concluded that the direct and indirect impacts of OCS pipelines were
                 virtually nil. At least part of the reason for this low level of impact was ascribed to a barrier island system with
                 adequate sediment in transport and a relatively stable and firm marsh substrate behind the islands. This
                 analysis assumes that existing pipeline crossings along the Texas and western Louisiana coasts will not result
                 in breachings or accelerated erosion.
                      The addition of three new pipeline landfalls is estimated to result from future and prior OCS sales in the
                 WPA_ Current environmental regulations and pipeline emplacement techniques are sufficient for minimizing
                 impacts from future pipeline projects.
                      The construction and maintenance of navigation canals through barrier island passes can have impacts on
                 the surrounding landscape. Stabilization of these channels with jetties can interfere with longshore sediment
                 transport, resulting in the accumulation of sediments on the updrift side of the jetty and erosion on the
                 downdrift side. Wicker et al. (1989) have documented this effect at the Matagorda ship channel. Although
                 no new navigation canals are expected to result from the proposed action, the ongoing impact from existing
                 channels is likely to affect barrier landforms. The impact from navigation channels is limited to the immediate
                 area downdrift from the channel jetties. Accelerated erosion immediately downdrift from the channel will be
                 coupled with accretion updrift from the channel jetty. No new navigation canals are expected to be installed
                 during the next 35 years for other purposes. The basis for this assumption is that the large number of existing
                 navigation canals can accommodate future navigation needs.










                                                                                                                             IV-487

                     Section IV.A.3.c.(3)(c) states that a channel in onshore Subarea W-1 (the Corpus Christi@ Texas, area) will
                 be deepened to 6.7 m (22 ft) toprovide access for larger service vessels that are expected to be used in deep-
                 water operations. Navigable barrier passes in the area exceed this depth. It is assumed that channel deepening
                 will occur in waterways that are located behind barrier islands and provide access to support base locations.
                 Deepening the channel will not affect barrier beaches.
                     Three new terminals are projected to be constructed along the coast under the Cumulative scenario (Table
                 IV-11). Two of the terminals are assumed to be located in the industrial areas of Matagorda and Mustang
                 Islands, the third on Matagorda Peninsula. No impacts to barrier landforms will result from the construction
                 of these facilities.
                     Efforts to stabilize the Gulf shoreline have impacted barrier landscapes. Undoubtedly, efforts to stabilize
                 the Texas coast with seawalls, groins, and jetties have contributed to coastal erosion. Although these structures
                 stabilize the immediate areas they are designed to protect, erosion can occur away from the structure. Morton
                 (1982) identifies coastal structures as one of the major causes of coastal erosion along the Texas coast.
                     The barrier islands in Texas are accessible for recreation because of their proximity to shore, their
                 connection to the mainland in many cases, and the large population that inhabits the coastal counties in Texas.
                 The Texas Open Beaches Act (1959) guarantees the public's right to unimpeded use of the State's beaches.
                 It also provides for means of public acquisition of private beachfront property. Public recreation along the
                 Texas coast is thus encouraged by the State. Recreational use of barrier islands can have impacts on the
                 stability of the landform. Vehicle and pedestrian traffic on sand dunes can weaken the vegetation that binds
                 and stabilizes the dune. Dunes that are affected in this way can be eroded by wind and wave forces. Judd et
                 al. (1988) documented that as much as 18 percent of the total dune area along parts of South Padre Island had
                 experienced damage from vehicular traffic.

                 Summary
                     Several impact-producing factors may threaten barrier landforms under the Cumulative scenario. The
                 amount of sediment that is delivered to the Texas coast has decreased because of dam construction on coastal
                 rivers, compartmentalization of the coast with groins and jetties, and a natural decrease in sediment supply as
                 a result of climatk changes during the past several thousand years.
                     Pipeline landfalls have been alleged to be possible sites of accelerated shore erosion and island breaching
                 along the Texas coast. A recently completed, MMS-ftinded study of pipeline landfall impacts (Wicker et al.,
                 1989), however, documented little to no impacts of pipeline landfalls.
                     Oil spills from several sources could contact barrier landforms. It is assumed that several spills greater than
                 or equal to 1,000 bbl from both onshore and offshore sources and that several smaller spills will contact coastal
                 barriers. The impacts of the cleanup of these spills along the Texas coast could result in short-term (up to two
                 years) adjustment in beach profiles and configurations as a result of sand removal and disturbance during
                 cleanup operations.
                     Three new pipeline landfalls are projected for the Western Gulf under the Cumulative scenario. Modern
                 techniques that do not result in noticeable impacts to coastal habitats will be used to install pipelines.
                     The construction and maintenance of navigation channels through barrier passes can interfere with littoral
                 dynamics and cause localized, accelerated erosion. Wicker et al. (1989) have documented localized accelerated
                 erosion downdrift of jetties installed to stabilize navigation channels. Localized erosion in these settings is
                 expected to continue.
                     Beach stabilization projects, such as groins, jetties, and seawalls, are expected to cause accelerated coastal
                 erosion. The impacts of fixed structures on the erosion of the barrier coast have not been quantified.
                     Recreational usage of barrier beaches in the Western Gulf is intense because of the proximity of the
                 beaches to shore, their connection to the mainland, and the large population that inhabits the coastal counties
                 in Texas.
                     During this century, the annual rate of coastal land loss in Texas has increased from 13 ha at the turn of
                 the century to nearly 65 ha in 1980 (Morton, 1982). According to Wicker et al. (1989), approximately 280 kni
                 of the Texas coast are experiencing erosion. The weighted average erosion rate along this stretch of coast is










                  IV488

                  5.9 m/yr. Another 212 kin of coast are experiencing aggradation at an average rate of 2.9 m/yr. The average
                  change over the entire Texas coast has been erosional at a rate of 2.1 m/yr.
                      The contributionof OCS activities associated with the Cumulative scenario to coastal barider beach impacts
                  is expected to be very low because oil-spill cleanup operations, pipeline landfalls, and navigation channel
                  deepening and maintenance projects will not result in large amounts of barrier beach changes.

                  Conclusion


                      Under the Cumulative scenario, the observed erosional trend of barrier features will continue along the
                  Gulf Coast in the area of potential impact. The major causes of the impacts are the reduction in sediment
                  being delivered to the coastal littoral system, sea level rise, the effects of navigational and erosion control
                  structures, and some recreational impacts.

                  (b) Wetlan&

                      This Cumulative Analysis considers the effects of impact-producing factors related to the proposed action,
                  plus those related to the Central Gulf proposed action, prior and future OCS sales, State oil and gas activities,
                  other governmental and private projects and activities, and pertinent natural processes and events that may
                  occur and adversely affect wetlands. As a result of these activities and processes, several impact-producing
                  factors will contribute to impacts on wetlands during the life of the proposed action.
                      Oil-spill contacts to coastal wetlands can occur ftom a number of sources. This analysis considers spills
                  in three size categories: greater than 1 and less than or equal to 50 bbl; greater than 50 and less than 1,000
                  bbl; and greater than or equal to 1,000 bbl. The effects of oil spills to wetlands under the Cumulative scenario
                  will be evaluated for OCS Program spills and for imported/onshore crude and petroleum products spills. Spins
                  from offshore and onshore sources will be considered.
                      No spills less than 1,000 bbl are assumed to occur offshore and contact wetlands as a result of OCS
                  Program activities. Seven offshore spills greater than or equal to 1,000 bbl are assumed to occur as a result
                  of OCS Program activities. According to Table IV-22, the probability of occurrence and contact within 10 days
                  from these spills ranges from 12 percent along the Chenier Plain coast in Louisiana to 6 and 9 percent for the
                  Central and East Texas wetlands respectively. Spill contacts that occur along the Louisiana coast as a result
                  of OCS Program activities have been discussed and analyzed in Section IV.D.La.(1)(b) and va not be covered
                  here. Based on the low probabilities in Table IV-22, this analysis assumes no contacts will occur along the
                  Texas coast.
                      Onshore spills could also occur from OCS operations and contact coastal barriers. These spills could occur
                  as a result of pipeline accidents or barge and shuttle tanker accidents during transit or offloading. According
                  to Table IV-13, about two-thirds of the oil transported by pipeline will land in onshore Subarea W-2, and
                  another one-fourth will land in Subarea W-1. The most likely area for pipeline accidents would, therefore, be
                  in Subarea W-2. Further, according to Table IV-13, Subareas W-1 and W-2 are the most likely places for the
                  occurrences of barge and shuttle tanker accidents. This analysis assumes that about six spills greater than 1
                  and less than or equal to 50 bbl, one spill greater than 50 and less than 1,000 bbl, and one spill greater than
                  or equal to 1,000 bbl will occur onshore as a result of OCS Program activities. Most of these spills will occur
                  in onshore Subarea W-2; the rest will occur in Subarea W-1. Assuming that a few of these spills result in
                  contact to wetlands and that 75 percent of the oil contacts wetlands, a spill averaging 6,000 1Jbl could result in
                  32 ha of wetlands vegetation experiencing dieback and plant mortality. Most of the contacted vegetation is
                  assumed to recover within three growing seasons. Some wetlands, particularly along channel margins, where
                  the marsh soil is susceptible to wave attack, will be eroded.
                      Non-OCS spills can occur as a result of import tankers, tidelands oil activities, and petroleum product spills.
                  It is assumed that numerous category spills less than 1,000 bbl will occur and contact wetlands. Most of these
                  will be spills less than or equal to 1 bbl, resulting in only small amounts of oiling. Eighty crude oil and product
                  spills greater than or equal to 1,000 bbl (7,000-bbl average) are assumed to occur during the life of the
                  proposed action from offshore and onshore sources. Several contacts to wetlands are assumed. A few hundred










                                                                                                                           IV-489

                or more hectares of wetlands are assumed to be affected similarly to the effects described above for the
                onshore OCS spills.
                     Under the Cumulative scenario, spills that occur in or near Padre Island and Corpus Christi could
                potentially contact seagrass beds. Spills in these areas could result from accidents involving import tankers and
                barges travelling to refineries and oil storage facilities near Corpus ChristL As discussed in the Base Case
                analysis (Section IVD.La.(1)(b)), oil-spill impacts to seagrasses are usually buffered by the subtidal position
                of seagrasses, resulting in little direct contact to the seagrass vegetation from a spill. Furthermore, because so
                much of the seagrass biomass is contained in roots and rhizomes, which are buried in sediment, seagrasses have
                a high regenerative capacity when their vegetative parts are contacted by oil. Seagrass beds in the area,
                however, occur at shallow depths, because of which it is assumed that a spill contact will result in some
                vegetation dieback. Because of the large number of potential spills from barge and tanker accidents in and
                near Corpus Christi, it is assumed that several contacts to seagrass beds will occur and will result in grass
                vegetation dieback. The affected vegetation will be replaced, for the most part, with healthy new growth within
                one growing season. Although no to little direct permanent mortality of grass beds is assumed as a result of
                oil-spill occurrences, contact of seagrasses with crude and refined oil could be a causative factor in the decline
                of grass beds and in the observed changes in species composition within beds.
                     Under the Cumulative scenario, three new terminals are expected to be constructed onshore (Table IV-13).
                These terminals are expected to be constructed on developed industrial areas of barrier islands and on upland
                areas of the mainland. No impacts to wetlands are anticipated.
                     Three new pipelines traversing 120 kin of coastal habitat are expected as a result of previous and future
                OCS leasing during the life of the proposed action. Wicker et al. (1989) observed no significant differences
                in plant cover and productivity between back-filled pipeline canal rights-of-way and nearby undisturbedwetland
                areas in the affected area. This analysis assumes impacts of 0.68 ha/km of onshore pipeline. Assuming the
                pipeline right-of-way is entirely within wetlands, up to 82 ha of wetlands could be affected.
                     No new navigation channels are projected under the Cumulative scenario (Table IV-13). Some deepening
                and maintenance dredging of existing channels may occur. Maintenance dredging could harm wetlands if the
                dredged material is deposited onto wetlands, resulting in burial or impoundment of marsh areas. This
                document assumes, however, an increasing implementation of dredged material disposal for wetland
                enhancement and creation during the life of the proposed action. Furthermore, according to Table IV-15, the
                channels used by vessel traffic associated with OCS program activities in the WPA have only a small percentage
                of their usage accounted for by OCS activities.
                     As discussed in Section IV.A.3.c.(3)(c), OCS activities in deep water are requiring larger service vessels
                for efficient operations. Currently, service bases in Galveston, Texas, and Berwick, Louisiana, are accessible
                to the larger vessels, and Empire and Cameron, Louisiana, are considered marginally usable. This document
                assumes that one channel in onshore Subarea W-1 (the Corpus Christi area) will be deepened to 6.7 m (22 ft).
                Navigable barrier passes in this area exceed this depth. It is assumed that channel deepening will occur in
                waterways located near support facility locations. As discussed in the analysis of impacts to wetlands in the
                CPA (Section IV.A.La.(1)(b)), the dredged material generated by the deepening project will be used to
                enhance wetland growth, rather than be disposed of onto spoil banks adjacent to the channel. No impacts to
                wetlands are therefore expected as a result of the channel deepening project.
                     Vessel traffic within navigation channels can cause channel bank erosion in wetland areas. An idea of the
                magnitude of OCS vessel traffic is provided in Tables IV-13 and IV-15, which show projected numbers of
                barge, service vessel, and shuttle tanker landings and dockings at various ports. Over the 35-year life of the
                proposed action, about 759 barge trips and 211,000 service vessel trips will occur within navigation channels.
                Additional vessel usage of navigation channels will be required for pipelaying barges and the movement of
                platforms to off-shore locations. Most of this vessel traffic will use channels within the Texas (onshore Subareas
                W-1 and W-2) and western Louisiana coastal zone, where the impacts will be assessed. According to Johnson
                and Gosselink (1982), channels that have high navigational usage in coastal Louisiana widen about 1.5 m/yr
                more rapidly than channels that have little navigational usage (2.58 m/yr versus 0.95 m/yr). It is assumed that
                this figure applies to the potential impact area associated with the proposed action, even though most of this
                area is within the State of Texas. According to Table IV-15, there are 15 channels that are used by OCS vessel
                traffic related to Sale 143. The OCS usage of these channels will account for about 10 percent of the total










                IV-490

                channel traffic. Assuming that an average distance along a channel to a service base and other OCS facilities
                is 10 km in the area and that wetlands fringe the channel over one-half this distance, the est[mate of channel
                erosion impacts is that about 40 ha of wetlands will be eroded along channel banks during the 35-year life of
                the proposed action. General navigation activity in these channels should result in at least nine times more
                erosion, based on the 10-percent proportion of the traffic attributed to OCS vessels.
                    According to Table IV-13, 602,000 bbl of produced sands and 9,322,000 bbl of drilling fluids Will be
                transported to shore for disposal under the High Case scenario. According to USEPA information, sufficient
                disposal capacity exists at operating disposal sites, and no new disposal sites will be required to accommodate
                these wastes. T'herefore, no wetland areas will be disturbed as a result of the establishment of new disposal
                sites. Some seepage from waste sites may occur into adjacent wetland areas and result in damage to wetland
                vegetation.
                    The WPA nonforested wetland habitat base, 245,700 ha (611,760 ac), is decreasing; however, no composite
                annual rate of decrease is available. Preliminary examination of available data sources indimtes as much as
                a 35-percent loss of coastal marshes between the mid-1050's and the mid-1970's (Texas Parks and Wildlife
                Dept., 1989). These estimates, however, are not based on rigorous or controlled analyses of the existing data
                sources. Areas of most extensive wetland loss occur in the Galveston-Houston area (White et al., 1985) and
                the Beaumont-Port Arthur area (Gosselink et al., 1979). Observed changes in WPA wetland patterns reflect
                the effects of submergence on wetland habitats. Wetlands are migrating landward over terrestrial habitat while
                eroding along their seaward margin in response to a marine transgression. The rate of erosion exceeds the rate
                at which terrestrial zones are being converted to wetlands, resulting in a net loss of wetland area (White et al.,
                1985). The rate of wetland loss in Texas has not been quantified, although in some areas of Texas, bay
                shorelines are eroding by as much as 2.4 m/yr (White et al., 1985). This erosion is the result of natural
                processes (sea level rise), perhaps exacerbated by localized, human-induced coastal subsidence caused by fluid
                withdrawals (Ratzlaff, 1980).
                    The contributionof OCS activities associated with the Cumulative scenario to wetland impacts is expected
                to be very low because of the small proportion of the total impacts to wetlands that can be attributed to OCS
                related spills, the small percentage of the vessel usage of navigation channels that can be attributed to OCS
                activities, the small amount of expected new infrastructure construction in wetland areas, and the dominating
                importance of sediment deprivation and submergence to the wetlands loss problem.

                Summary

                    Several oil spills smaller than 1,000 bbl and greater than or equal to 1,000 bbl from onshore and offshore
                sources are assumed to contact coastal wetlands in Texas. The combined impacts of these spills are assumed
                to affect up to a few hundred hectares of wetlands. In the affected areas, the vegetation could be killed back
                or stressed for up to two years, and accelerated erosion along marsh shorelines could occur where marsh
                vegetation has been affected by spilled oil. Some seagrass beds in the Corpus Christi area could be contacted
                by crude and refined oil. These contacts will result in some short-term dieback of the grasses and general
                weakening of the seagrass communities.
                    Onshore construction of oil and gas infrastructure is not expected to result in the conveision of wetlands
                to commercial land. No new navigation channels are expected to be dredged for OCS activities, although some
                new channels or deepening of existing channels may occur for other navigational purposes. Dredged material
                from maintenance dredging and channel deepening is expected to be disposed of to enhance or create wetland
                habitats. About 40 ha of wetlands along navigation channel margins are expected to be eroded as a result of
                OCS Program activities. A much larger amount of erosion is expected from general navigation activity.
                    Wetlands along the Texas coast and adjacent areas of Louisiana are eroding as a result of riatural processes
                (e.g., coastal submergence). Although wetland erosion rates have not been quantified, wetland erosion has
                been commonly observed along the Texas coast.










                                                                                                                          IV491


               Conclusion

                    Under the Cumulative scenario, losses of wetlands are expected to continue. The major cause of this loss
               is expected to be coastal submergence.

               (2) Impacts on Sensitive Offshore Resources

               (a) Deep-water Benthic Communities

                    Cumulative factors considered to impact the deep-water benthic communities of the Western Gulf include
               both oil- and gas-related and non-oil- and gas-related activities. The latter type of impacts includes activities
               such as fishing, trawling, and anchoring. However, fishing and trawling in the deeper waters of the Central and
               Western Gulf are minimal and impacts are minimal. Oil- and gas-related activities include pipeline and
               platform emplacement activities and anchoring, instances of which are expected to be higher than under the
               Base Case (Section IV.13.2.a.(2)(a)). This analysis considers the effects of these factors related to the proposed
               action and to prior and future OCS sales.
                    The greatest potential for adverse impacts to occur to the deep-water benthos stems from pipeline and
               platform emplacement and associated anchoring activities. The impacts to benthos from these activities are
               discussed above. As exploration and development continue on the Federal OCS, activities in the Central and
               Western Gulf regions have moved into the deeper water areas of the Gulf of Mexico. With this trend comes
               the certainty that increased development will occur in these areas, accompanied by stress to the deep-water
               benthos from bottom disturbances and disruption of the seafloor from associated activities. The extent of this
               disturbance shall be determined by the intensity of development in these deep-water regions, as well as the
               types of structures and mooring systems utilized. For instance, Table IV-8 indicates that in the WPA an
               estimated 5,280 exploration and delineation wells and 2,050 development wells will be drilled, and 140
               platforms will be installed. However, as noted in Section IV.13.2.a.(2)(a) above, NTL 88-11 operates to protect
               high-density chemosynthetic communities in a high percentage of the cases (but not 100% of the time); for
               purposes of this analysis, the frequency of impact from bottom disturbance is considered to be once every six
               months to two years, but the severity of impact is such that the loss of elements and/or relationships will not
               occur.


               Summary

                    The only impact-producing factor threatening the chemosynthetic communities is physical disturbance of
               the bottom, which would destroy the organisms comprising these communities. Only structure emplacement
               is considered to be a threat, and then only to the high-density (Bush Hill-type) communities; the widely
               distributed low-density communities would not be at risk. The provisions of NTL 88-11 (currently in effect),
               requiring surveys and avoidance prior to drilling, will reduce, but not completely eliminate, the risk.
                    Activities not related to the OCS oil and gas program include fishing, trawling, and anchoring. Because
               of the water depths in these areas, these activities are not expected to have any impact on the chemosynthetic
               communities.
                    The cumulative impacts are expected to be due entirely to the activities of the proposed action (as analyzed
               in Section IV.13.2.a.(2)(a)) because activities unrelated to the OCS oil and gas program, such as fishing,
               trawling, and anchoring, are not expected to have any impact on these chemosynthetic communities.

               Conclusion


                    The activities associated with the Cumulative scenario are expected to cause little damage to the physical
               integrity, species diversity, or biological productivity of either the widespread, low-density chemosynthetic
               communities or the rarer, widely scattered, high-density Bush Hill-type chemosynthetic communities. Recovery
               from any damage is expected to take less than two years.










                  IV492

                  (b) Topographic Features

                      Oil and gas leasing has been increasing around the topographic features of the Western Gulf, and this
                  trend is expected to continue in the future. Of the 200 blocks in the WPA that are neair the topographic
                  features, 113 are under active lease (Appendix A). Many oil and gas operations on the previously leased blocks
                  are subject to the provisions of a biological stipulation. The impact analysis below is presented for the
                  proposed action and does include the Topographic Features Stipulation. These operations are not expected
                  to have an adverse impact on the biota of the topographic features. Thus, the impact from cumulative oil and
                  gas routine operations would be limited to those from the operations conducted as a result of any future OCS
                  sales held without benefit of the stipulation. These impacts are estimated to be very destructive of the reef
                  communities of the banks (Section II.B.l.c.(l)). The impacts from cumulative oil and gas routine operations
                  include those from the operations conducted as a result of the proposed action (as explained in Section
                  IV.D.2.a.(2)(b)). The operations include anchoring and structure emplacement, effluent discharge, blowouts,
                  oil spills, and structure removal, future OCS sales, past sales (which include the biological stipulation of Section
                  II.B.1.c.(I)), hurricanes, the activities of scuba divers, the collapse of the tops of the features due to dissolution
                  of the underlying salt structure, ocean dumping, and the tankering of imported oil.
                      Anchor damage and damage from structure emplacement are considered to be the most serious threats
                  to coral and coral-community areas (Bright and Rezak, 1978; Rezak and Bright, 1981). The biological
                  stipulation on the existing leases and proposed for leases resulting from this proposed action would prohibit
                  the anchoring of industry-related vessels and the emplacement of structures by the industry in the No Activity
                  Zones; the potential stipulation would not affect other activities such as anchoring, fishing, or recreational scuba
                  diving. No data are available on the extent to which such anchoring may take place; however, all three
                  activities are known to occur in proximity to the topographic features. Nearly all the banks are near established
                  shipping fairways. The banks are apparently well-known fishing areas. Several of the shallower cresting banks
                  are scuba trip destinations. Anchoring at a topographic feature by a vessel involved in any of these activities
                  would cause significant damage to the biota, and although the degree of damage would depend on the size of
                  the anchor and chain, there is the potential for serious anchor damage to the biota of the topographic features.
                  Treasure hunters have destroyed large areas of Bright Bank by using explosives to blast through the coral reef.
                  The impact has been high to Bright Bank (in the Central Gulf) as a result of this blasting activity, however,
                  such blasting is not a common event. All of the impacts described above for the Base Case would also pertain
                  in this case. Thus, for the purpose of this analysis, the frequency of these events is judged to be once or twice
                  each year, and the severity of the impact is considered to be such that there is no loss of' elements and/or
                  relationships. Such perturbations would last for periods from 6 months to 2 years at the regional scale and for
                  periods of 2-5 years at the local scale. Recovery of the system to pre-interference conditions is probable.
                      The routine discharge of drilling muds and cuttings will greatly increase under this scenario. As noted
                  above under the Base Case, most water-based fluids are relatively nontoxic (the more toxic effluents are not
                  allowed to be discharged under the NPDES permit), and their effects are limited to the immediate vicinity of
                  the discharge (NRC, 1983). No effects to the biota of the topographic features are assumed due to toxicity.
                  Small amounts of drilling effluent may reach a bank from wells drilled more than 1,000 nt away; however, these
                  amounts from single wells, where measurable, would be extremely small and would have no effect on the biota.
                  Effluents discharged at the water's surface within 1,000 m of a bank could impact the biota of the bank,
                  although the currents at the banks would tend to keep the bank swept clean of fine sediments and would
                  prevent the accumulation of drilling muds at the bank. The muds and cuttings can smother the sessile benthic
                  invertebrates; turbidity from the discharge can reduce light levels to benthic organisms and clog the feeding
                  mechanisms of sessile invertebrates. These conditions can lead to reduced productivity,, susceptibility to
                  infection, and mortality. The MMS, as a condition of the operational plan approval, can require the operator
                  of a lease to perform certain measures, such as shunting, that would reduce the impacts to the biota of the
                  banks to very low. The USEPA, through its NPDES permitting procedures, may also require mitigative
                  measures. Current leases contain, and leases resulting from this proposed action near topographic features
                  may contain, at the option of the Secretary, a biological stipulation that protects the biota of the bank from
                  most impacts from oil and gas operations, but leases resulting from future lease sales may not contain this










                                                                                                                             IV-493

                restriction. For purposes of this analysis, it is assumed that such impacts will occur once each year and that
                the severity of the impacts is judged to be such that there is no loss of elements and/or relationships. Such
                perturbations would last for short periods at both the regional and local scales. Recovery of the system to pre-
                interference conditions would be rapid.
                    There is an estimated 79-percent chance of an oil spill (1,000 bbl or greater) occurring in the Western Gulf
                as a result of the OCS Program Table IV-19. It is also assumed that 183 spills of greater than 1 and less than
                50 bbl will occur each year, and that 7 spills greater than 50 and less than 1,000 bbl will occur during the 35-
                year life of the proposed action (Section IV.C.1.). It is assumed that 2 oil spills 1,000 bbl or greater will occur
                on the OCS from OCS oil and gas operations, with an additional 37 spills resulting from import tankering
                (Section IV.C.1.). Because of the water depths in which topographic features are found, no oil will reach the
                biota of concern. As discussed for the Base Case, blowouts are rare in the Gulf and, even if one occurred, it
                is assumed that any oil spilled into the water column from a blowout would reach the biota of a topographic
                feature. Therefore, it is assumed that no spills of any size will contact the biota of the topographic features.
                    Many platforms could be removed during the life of this proposal; some may be near topographic features.
                However, the proposed Topographic Features Stipulation (Section II.B. l.c.(1)), which has been applied in the
                past to all leases on or near such features and which could be applied to leases resulting from this proposed
                action, prevents the installation of platforms in the near vicinity of the biota of concern, thus reducing the
                potential for impact from this factor. Therefore, the impact from this factor would be negligible. See Section
                IV.A-2.a.(3) for more information regarding structure removals.
                    Impacts to the topographic features could occur as a result of operational discharges from import and
                shuttle tankers. Due to the dilution factor and the depths of the banks, this activity is expected to have a very
                low level of impact on the topographic features. This is also true for the very low level of ocean dumping that
                occurs in the Gulf (and which is being phased out).
                    Impacts from natural occurrences such as hurricanes are not expected to result in damage to the biota of
                the banks. Collapse of the crest of the banks from dissolution of the underlying salt structure is possible, but
                unlikely and certainly uncontrollable by human activity.
                    Scuba divers may visit the shallow banks, and their collecting activities may have an adverse impact on the
                biota of those banks. Other than anchor damage, however, such activities are not expected to have major
                impacts on the banks.
                    The other impacts to the biota of the topographic feature described above for the Base Case would also
                obtain here, but at a greatly increased level.

                Summary

                    Those activities causing physical disturbance to the bottom of the topographic features and presenting the
                greatest threat to the biotic communities of the banks would be prevented by the imposition of the
                Topographic Features Stipulation.
                    Non-OCS oil and gas activities are judged to have little, if any, impact on the biota of the topographic
                features (except for anchoring, described in detail above). These activities include hurricanes, activities of scuba
                divers, the collapse of the tops of the banks, ocean dumping, and the tankering of imported oil.
                    Activities resulting from this proposed action, especially bottom-disturbing activities, have a potential for
                causing low impacts to the biota of the topographic features. While some of the activities are expected to
                result in lower impacts, those having the greatest impacts are also those most likely to occur.
                    The cumulative impact to topographic features is expected to be low. The incremental contribution of the
                proposed action (as analyzed in Section IV.13.2.a.(2)(b)) to the cumulative impact level is very low because of
                the implementation of the Topographic Features Stipulation, which would limit operational discharges and to
                the low probability (and thus risks) of accidental OCS-related events such as blowouts and oil spills.










                 IV-494


                 Conclusion


                     The activities assumed for the Cumulative scenario are expected to cause little to no damage to the
                 physical integrity, species diversity, or biological productivity of the habitats of the topographic features of the
                 Gulf of Mexico. Small areas of 5-10 m2 would be impacted, and recovery from this damage to pre-impact
                 conditions is expected to take less than 2 years, probably on the order of 2-4 weeks.

                 (3) Impacts on Water Quality

                 Coastal and Estuarine Waters


                     The Cumulative Analysis considers the effects of low-level routine point and nonpoint source discharges,
                 such as industry effluents, both chronic low-level and large accidental hydrocarbon and cheinical discharges,
                 and natural seepage entering the coastal or nearshore waters of the northern Gulf of Mexico. These discharges
                 occur from urban and agricultural expansion, municipal and industrial wastes, recreational and commercial
                 boating, maritime commerce, dredging activities, natural events, State oil and gas development activities, and
                 the proposed action plus other OCS oil and gas development activities due to past and future sales. Section
                 IV.B. presents information on major activities occurring in the Gulf and its coastal areas.
                     Those non-OCS activities that impact coastal and estuarine water quality include nonpoint source
                 contamination,vessel traffic, dredging, and State oil and gas activities (Section IV.D. Ld.(3)). Dredging activities
                 (Section IV.B.) associated with maintenance dredging and deepening of channels, and creation of ports,
                 marinas, and private docks will continue to impact the Gulfs coastal waters. Maintenance dredging is ongoing,
                 especially in major port areas (Houston Ship Channel, Galveston and Corpus Christi Bays, and Sabine Pass)
                 and along the Gulf Intracoastal Waterway (GIWW). Dredging activities are expected to result in localized
                 impacts (primarily elevated water column turbidities) occurring over the duration of the activity (up to several
                 months).
                     Continued offshore and onshore oil and gas activities will contribute to the cumulative impacts on coastal
                 and nearshore water quality. An unknown number of additional structures and facilities may be constructed
                 as a result of resource development in State waters and coastal areas. The construction and operation of
                 onshore facilities supporting domestic and international oil and gas activities may impact coastal and nearshore
                 water quality by routine point and nonpoint source pollution. Increased effluent discharges from support
                 facilities may contribute to point source pollution within coastal areas. Surface runoff from existing refining
                 and processing facilities is extensive and can adversely impact the surrounding area. Because the majority of
                 the facilities expected to support oil and gas refining and processing activities are located primarily in coastal
                 Texas and Louisiana, impacts of chronic discharges from these sources are expected to be focused there.
                     Oil-field wastes generated from coastal and offshore oil and gas development activities and disposed of in
                 the Texas and Louisiana coastal zones area may contaminate groundwater and coastal water quality. Produced
                 waters discharged from State oil and gas activities have been substantial and have had adverse, effects at many
                 of the discharge sites. Boesch and Rabalais, (1989a) estimated that 823,575 bbl of produced waters from Texas
                 State off and gas activities were discharged daily into Texas State waters. At present, the State of Texas is
                 examining the issue of produced water discharging into its coastal and nearshore waters. The estimate, based
                 on the Boesch and Rabalais studies, is that elevated levels of salinity (50-150 ppt), dissolved and dispersed
                 petroleum hydrocarbons (10-50 ppm), organic acids, radionuclides, and trace metals may result around sites
                 discharging into coastal and nearshore waters. Concentrations of the organic constituents will depend on the
                 separation and treatment technologies employed. Substantial hydrocarbon contamination of fine-grained
                 sediments may extend out from several hundred meters to over one kilometer from the point of discharge.
                 Concentrations of aromatic hydrocarbons in sediments may exceed background levels by over an order of
                 magnitude.
                     It is assumed that 37 oil spills greater than or equal to 1,000 bbl will occur from import tankering in the
                 Gulf of Mexico during the life of the proposal. The average size of an import tanker spill is estimated at
                 30,000 bbl. Eight import spills (approximate size of 7,665 bbl) are assumed to occur in nearshore waters and










                                                                                                                             IV-495

                 in port areas. The Houston-Galveston port area is assumed to receive the greatest number of these spills.
                 Another 44 spills (average size of 10,000 bbl) are estimated to occur in the Texas coastal zone from coastwise
                 movement of petroleum products. Most of these spills are assumed to occur in the GIWW. Petroleum
                 hydrocarbons introduced into marine and coastal waters may have varied effects depending on the resource
                 impacted, stage of weathering, and local physical and meteorological conditions. Some crude oil components
                 are highly toxic and may cause damage to marine organisms due to the crude's aromatic content. It is expected
                 that encountered, normal weathering processes will detoxify the oil by breaking down its toxic components.
                 Background levels in the Gulf of Mexico were reported at 0-70 gg/l. In shallow areas, off may become
                 entrained in suspended particles and bottom sediments, and subsequently be reintroduced into the water
                 column. The assumption, based on these estimates and the frequent nature of spills over the life of the
                 proposal, is that the effect of hydrocarbon contamiation on the Gulfs coastal waters due to the proposed
                 action is considered negligible, with water characteristics rapidly returning to background levels within several
                 days to weeks.
                    With regard to OCS-related activities, within the Gulfs coastal zone, much of the existing infrastructure
                 supporting offshore OCS oil and gas activities is distributed throughout coastal Texas and Louisiana. About
                 90 percent of the existing capacity or frequency usage of the oil industry infrastructure will support OCS
                 operations in the future. The addition of three new pipeline landfalls (W-1), 120 km of onshore pipelines (80
                 kin in W-1 and 40 kin in W-2), and three new terminals (W-1) is estimated to result from the cumulative OCS
                 activities in the WPA. Both the use of new oil and gas facilities once constructed and the use of the existing
                 facility network would contribute to the number of effluents expected to be discharged into coastal waters from
                 petroleum activities primarily in the Louisiana coastal zone. The construction and operation of onshore
                 facilities supporting OCS activities may impact coastal and nearshore water quality by routine point and
                 nonpoint source pollution. Increased effluent discharges from support facilities may contribute to point source
                 pollution within coastal areas. These effluents are commonly discharged into surface waters after treatment.
                 Surface runoff from existing OCS facilities is extensive and can adversely impact the surrounding area. Runoff
                 from these facilities is likely to contain oil, brine, particulate matter, heavy metals, petroleum products, process
                 chemicals, and soluble inorganic and organic compounds leached from the soil surface. Aside from adding
                 contaminants to coastal waters, runoff from such facilities may alter circulation in wetland areas and affect
                 flushing rates and salinity gradients. Because the majority of the facilities expected to support offshore oil and
                 gas activities are located in Texas and Louisiana, impacts of chronic discharges from these sources are expected
                 to be focused there.
                     Vessel traffic associated with OCS oil and gas industry activities is expected to be extensive in the Texas
                 and Louisiana coastal areas, especially within the Mississippi Delta area. Approximately 211,000 service vessel
                 trips are estimated to support cumulative OCS activities in the WPA. Waterways along the Texas coast, where
                 projected service vessel traffic will be the greatest, include Houston-Galveston Ship Channel, Sabine Pass, and
                 Aransas Pass. The other navigation channels will have significant but less OCS vessel traffic. Import tankering
                 and barge trips (759 barge vessel trips related to OCS production activities) carrying both domestic and
                 imported crude oil and products between terminals and refineries along the GIWW, adjoining navigation
                 channels, and along coastal nearshore fairways will add to this traffic. Shuttle tankering associated with OCS
                 production in the WPA will result in 960 trips. While inshore, service vessels are estimated to discharge
                 approximately 3,000 liters of bilge water per trip in support of OCS-related activities. An estimated 669 billion
                 liters (5 million liters/day) will be discharged into coastal waters of the WPA from vessels supporting OCS
                 activities. Discharges from service boats and barges, although diluted and discharged slowly over large lengths
                 of channel, will be great enough to result in some water quality degradation in the traversed navigation
                 channels and GIWW. As noted in Alternative A, antifouling paints used on boats and tankers have been
                 shown to have toxic effects on some marine biota. Increased loadings within coastal waters of tributyltin and
                 copper compounds contained in antifouling paints are expected. Ballast and bilge waters from shuttle tankers
                 are assumed to be discharged at onshore reception facilities and are not expected to impact coastal water
                 quality. Operational discharges from shuttle tankering offshore are expected to add to the overall hydrocarbon
                 contamination of nearshore open waters. Tarballs formed from these service vessel discharges will impact the
                 Gulf's coastal beaches. Because no new service base locations are projected for OCS activities, and none is
                 likely for State activities, operational discharges associated with OCS service vessel traffic will not impact











                  IV496

                  coastal water quality. Impacts from such sources are substantial enough to cause low-level effects when
                  discharged into confined waters over a long time p@riod. Impacts to open waters are expected to be negligible.
                      No new navigation channels ar6'expected to be dredged; however, maintenance d:redging of major
                  navigation channels and deepening of some channels to support service vessel traffic are expected to result.
                  Dredging activities are expected to result in localized impacts (primarily elevated water column turbidities)
                  occurring over the duration of the activities (up to several months). Such activities would preclude some
                  recreational and commercial uses within the immediate area. The periods for expected dredging operations
                  will generally allow for the recovery of affected areas between such activities. Impacts from dredging are
                  expected to be somewhat higher near the mouths of major rivers, where sediment in-puts are greater.
                  Approximately 120 kin of new pipelines are projected to be constructed in association with OCS activities; 98
                  percent of the off and all of the gas produced will be transported ashore via the existing pipeline network.
                  Pipelines reduce the need for barge and truck transport of petroleum and the potential for transfer spills. The
                  environmental effects associated with chronic pipeline leakage and malfunction are generally considered small
                  (USDOC, NOAA, 1985). Given this and the small percentage of use of the existing pipeline network in
                  support of the proposed action, impacts from leakage and hydrologic alterations associated with pipelines are
                  considered negligible.
                      It is assumed that IS percent of the drilling muds (9.3 MMbbl) associated with sale-related drilling activities
                  and 602,000 MMbbI of produced sand will be brought ashore for disposal. The improper storage and disposal
                  of such oil-field wastes and contaminated oil-field equipment could result in adverse impacts to surface and
                  ground waters in proximity to disposal facilities, cleaning sites, and scrap yards. Many of these wastes may be
                  contaminated by NORM. Improper design and maintenance of such facilities could result in adverse impacts
                  to these waters. The quantities of many wastes attributable to OCS activities, and mote specifically the
                  proposed action, are largely unknown, as are the associated environmental consequences and health risks.
                      Under the Cumulative scenario, two oil spills greater than or equal to 1,000 bbl would occur in the
                  northwestern Gulf offshore Texas. One of these oil spills would originate from a pipeline, whereas the other
                  would originate from a platform. The average size of these spills is 6,500 bbl. It is assumed that as much as
                  75 percent of the original volume of oft from the spill source would be lost as a result of weathering processes
                  by the time the slick contacts the coast. It should be noted that there could be some effects from residual
                  weathered oil that could reach coastal waters following a spill event, primarily in the form of tar material.
                  Impacts from low-level contamination were discussed earlier. It is further assumed that 7 offspills greater than
                  50 and less than 1,000 bbl and 183 oil spills greater than 1 and less than or equal to 50 bbl could occur from
                  OCS pipeline, platform, and transportation sources within the WPA. Of these, it is assumed that few would
                  contact coastal and estuarine waters. An additional 88 spills (less than 50 bbl--average size of 34 bbl) are
                  assumed to occur in the WPA from spills related to the use of diesel and other potential pollutants. The
                  effects of off spills on coastal and marine waters were discussed previously under import spins.
                      Petroleum product spills are of great concern because the refined products of crude oil are often more
                  toxic than crude itself. In general, refined oils are considered more toxic than crude due to the higher
                  concentrationof aromatic hydrocarbonsand their greater ability to dissolve and disperse into the water column
                  as a result of their less viscous nature. Refined oil, such as gasoline and kerosene, is assumed to cause
                  biological damage due to its toxicity over a relatively short period of time. Up to 44 petroleum product spills
                  (average size 10,000 bbl) and another 500 smaller spills (most are less than 1 bbl) will occur in the WPA. Of
                  these, most will occur in Louisiana port areas, along the GIWW, and near the Gulf coastline.

                  Summary

                      Routine point and nonpoint source discharges from non-OCS activities, such as agriculture, general
                  construction projects, hydromodification, silviculture, septic tank leakage, urban runoff, and especially oil and
                  gas activities will degrade coastal and estuarine waters within the Gulf of Mexico's coastal zone. In addition,
                  maritime activities are expected to contribute to the degradation of waters near ports and major navigation
                  channels. Total hydrocarbon concentrations measured in Gulf of Mexico oyster and sediment samples from
                  the NOAA Status and TrendsProgram were generally lower than hydrocarbon concentrations at east and west
                  U.S. coast locations, probably because the sites in the Gulf are farther removed from point sources. The











                                                                                                                             IV-497

                 following conclusions about hydrocarbon contamination can be made from the study: (a) chronic petroleum
                 contamination is taking place, possibly from oil and gas operations along the Gulf of Mexico coastline, but also
                 due to contamination of the discharge from the Mississippi River; and (b) water quality degradation is not
                 taking place to such an extent to show marked increases over U.S. coastal areas that do not have as many oil
                 operations.
                     All existing onshore infrastructure and associated coastal activities occurring in support of the proposed
                 action will contribute to the degradation of regional coastal and nearshore water quality to a minor extent
                 because each provides a low measure of continuous contamination and because discharge locations are
                 widespread throughoutthe Gulf Region. The effect of chronic contamination on the Gulfs coastal waters due
                 to the proposed action is considered negligible, with water characteristics rapidly returning to background levels.
                 The OCS-related vessel traffic is assumed to impact water quality through routine releases of bilge and ballast
                 waters, chronic fuel and tank spills, trash, and low-level releases of the contaminants in antifouling paints.
                 Depending on the length of the affected channel, flushing rates, etc., it is expected that there will be some
                 localized short-term change (up to several weeks) in water quality characteristics from background levels. The
                 improper storage and disposal of oil-field wastes and contaminated oil-field equipment would adversely impact
                 surface and ground waters in proximity to disposal facilities, cleaning sites, and scrap yards. Surface and
                 groundwater in proximity to improperly designed and maintained disposal sites and facilities could be adversely
                 impacted with elevated concentrations of arsenic, chromium, zinc, cadmium, mercury, lead, barium,
                 penta-chlorophenol, naphthalene, benzene, toluene, and radium.
                     Accidental spills will introduce off into nearshore waters, creating elevated hydrocarbon levels (up to 100+
                 gg/1) within affected waters. Much of the off would be dispersed throughout the water column over several
                 days to weeks. In shallow areas, off may become entrained in suspended particles and bottom sediments.
                 Water uses would be affected for up to several weeks from proposed spills and then only near the source of
                 slick. Other spills will occur from import tankering, transporting oil products throughout the Gulf, barging
                 crude oil, etc. Refined oils are considered more toxic than crude due to the higher concentration of aromatic
                 hydrocarbons and their greater ability to dissolve and disperse into the water column as a result of their less
                 viscous nature. Products such as gasoline and kerosene are assumed to cause biological damage due to their
                 toxicity over a relatively short period of time.

                 Marine Waters

                     This Cumulative Analysis considers the effects of impact-producing factors related to the proposed action,
                 plus those related to tankering and other vessel traffic, the Strategic Petroleum Reserve Program (SPRP), and
                 industrial waste disposal activities that may occur and adversely affect the offshore water quality in the northern
                 Gulf of Mexico. Specific types of impact-producing factors considered in the analysis include well-drilling
                 discharges, pipeline emplacement, hydrocarbon production formation waters, dredging, accidental oil spillage,
                 routine operational discharges, ocean disposal of hazardous material, and industrial waste discharges.
                     Those non-OCS factors that impact marine water quality include marine transportation, ocean dumping,
                 and the Strategic Petroleum Reserve Program (Section IV.D.Ld.(3)).
                     Spills from import tankering (average spill size 30,000 bbl) and Guliwide OCS activities may affect offshore
                 water quality as indicated (see previous discussion under Coastal and Estuarine Waters). It is assumed that
                 37 off spills greater than or equal to 1,000 bbl will occur from import tankering in the Gulf of Mexico during
                 the life of the proposal.
                     With regard to OCS activities, as indicated in the Base Case analyses, immediate effects would be brought
                 about by increased drilling, construction and pipelaying activities, causing an increase in water column
                 turbidities to the affected offshore waters. Pipeline construction activities may result in the resuspension of
                 some 1.2 million yd3  of sediment Offshore Subarea W-1 will support the greatest portion of program-related
                 pipeline burial activities and associated sediment resuspension, with 701,000 yd        3.  Pipeline construction
                 activities may result in the resuspension of settled pollutants, toxic heavy metals, and pesticides, if present.
                 Impacts resulting from resuspension of bottom sediments following an explosive structure removal include
                 increased water turbidity and mobilization of sediments containing hydrocarbon extraction waste (drill mud,
                 cuttings, etc.) in the water column. The discharge of 19.7 MMM3 of NPDES-regulated, treated sanitary and










                   IV498

                   domestic wastes from the various rigs and platforms will increase levels of suspended solids, nutrients, chlorine
                   and BOD near the point of discharge. These are considered minor discharges and are quickI          'y diluted. Treated
                   deck drainage and domestic wastes are most often taken ashore for proper disposal at an approved site. Up
                   to 2.4 Bbbl of produced waters are estimated to result from cumulative OCS activities in the WPA. Offshore
                   Subarea W-3 will receive the greatest number of these discharges with 1.54 Bbbl. From the findings of
                   investigators, MMS expects the effects of these discharges on offshore water quality to be limited to an area
                   in proximity to the discharge source.
                       Some 51.5 MMbbI of drilling muds and 12.7 million yd      3 of drill cuttings are estimated to result from drilling
                   activities associated with the cumulative OCS activities in the WPA_ As indicated in the Base Case analyses,
                   it is assumed that 18 percent of all muds used (9.3 MMbbl) will be brought ashore for disposal. Drilling muds
                   and cuttings are routinely discharged into offshore waters and are regulated by NPDES permits. As with
                   produced-water discharges, offshore Subarea W-3 would receive the greatest percentage of these potential
                   discharges, with an estimated 28.6 MMbbI of drilling muds and 7.2 million yd             3 of cuttirigs that could be
                   potentially discharged offshore. When discharged into the surrounding offshore waters, drilling muds may
                   create turbidity plumes several hundred meters in length. Studies indicate that these impacis are restricted to
                   an area within 300-500 ni of the discharge site. Dilution is extremely rapid in offshore waters. A 1983 NRC
                   study suggests that for routine oil and gas discharges, the various components measured, including turbidity,
                   are at background levels by a distance of 1,000-2,000 m. As in the Alternative A analysis, the natural processes
                   of dispersion, degradation, and sedimentation will result in immeasurably low concentrations of these materials
                   within a few meters to a few kilometers of the discharge site.
                       It has been recognized that spills of hazardous materials may, in many cases, pose a more serious threat
                   to marine ecosystems than oil spills. Substantial amounts of oil and hazardous materials enter the marine
                   environment as a result of accidental spills. Alternative A analyzes the severity of oil spills -to water quality in
                   general. Program-related spills are discussed in the previous section under Coastal and Estuarine Waters. It
                   is assumed that 44 petroleum product spills (10,000 bbl in size) will occur in the WPA from OCS-related
                   activities. As previously noted refined oils are considered more toxic than crude due to the higher
                   concentration of aromatic hydrocarbons and their greater ability to dissolve and disperse into the water column
                   as a result of their less viscous nature. Products such as gasoline and kerosene are assumed to cause biological
                   damage due to their toxicity over a relatively short period of time. Although the focus in the past has been
                   on the cleanup and mitigation of spilled oil, national attention has been shifting toward hazardous materials
                   as the cause for most immediate concern. Much has been learned in the past 10 years about how to respond
                   to off spills; far less is known for spills of hazardous material. Unlike oil, whose properties are fairly uniform,
                   hazardous materials have a wide variety of physical and chemical forms, complicating and making the response
                   necessary for their cleanup and disposal much more difficult. Methods for the cleanup and mitigation of
                   hazardous materials are not well established.


                   Summary

                       Those activities that would impact the Gulf's marine waters include marine transportation and OCS oil and
                   gas activities. Vessels range from small recreational craft used primarily in coastal waters to defense-related
                   naval vessels and ships of the merchant marine fleet up to several hundred thousand tons in size. Pollutants
                   from vessel traffic include large amounts of domestic waste products such as sewage, food waste, and trash
                   from the human activities on board. Other problems are related to the movement of crude oil and concern
                   offshore unloading terminals (deep-water ports).
                       With regard to OCS activities, immediate effects would be brought about by increased drilling, construction
                   and pipelaying activities, causing an increase in water column turbidities (lasting for several weeks) to the
                   affected offshore waters. The magnitude and extent of turbidity increases would depend on the hydrographic
                   parameters of the area, nature and duration of the activity, and bottom-material size and composition.
                   Offshore Texas would receive the greatest portion of program-related pipeline burial activities, whereas
                   offshore Louisiana would receive the largest amounts of program-related operational dischUges. Because of
                   the continuous nature of oil and gas activities in the northwestern and north-central Gulf of Mexico, the
                   frequency of drilling mud and cutting and produced-water discharges is judged to occur nearly continuously










                                                                                                                          IV-499
                throughout these areas. Proposed produced water discharges will be rapidly diluted within the immediate
                vicinity of the discharge source .. Significant increases in water concentrations of dissolved and particulate
                hydrocarbons and trace metals are not expected outside the initial mixing zone or the immediate vicinity of the
                discharge source. Mgher concentrations of trace metals, salinity, temperature, organic compounds, and
                radionuclides, and lower dissolved oxygen may be present near the discharge source. Within the mixing zone
                of the discharge, long-term effects to water column processes, consisting of localized increases in particulate
                metal and soluble lower molecular weight hydrocarbon (e.g., benzene, toluene, and xylenes) concentrations,
                may be expected. Trace metals and hydrocarbons associated with the discharge may be deposited within
                sediments near the discharge point. The proposed discharge of drilling fluids and cuttings would encounter
                rapid dispersion in marine waters. Discharge plumes will be diluted to background levels within a period of
                several hours and/or within several hundred meters of the discharge source. The accumulation of toxic trace
                metals and hydrocarbons in exposed shelf waters, due to periodic releases of water-based generic muds and
                cuttings, is unlikely, and the long-term degradation of the water column from such discharges is not a major
                concern. No effects to water uses from routine activities and discharges are expected.
                    Program-related and nonrelated crude oil spills will introduce off into offshore waters and create elevated
                hydrocarbon levels (up to 100+ Ag1l) within affected waters. Much of the oil will be dispersed throughout the
                water column over several days to weeks. Little effect to water use is expected from these spills, and then only
                in an area near the source and slick. Other spills will occur from import tankering (including oil from the
                TransAlaskan Pipeline), transporting oil products throughout the Gulf, barging crude oil, etc. Refinedoilsare
                considered more toxic than crude due to the higher concentration of aromatic hydrocarbons and their greater
                ability to dissolve and disperse into the water column as a result of their less viscous nature. Products such as
                gasoline and kerosene are assumed to cause biological damage due to their toxicity over a relatively short
                period of time.

                Conclusion


                    Cumulative demands resulting from the proposal are expected to result in significant changes to the
                ambient concentration of one or more water quality parameters, up to several hundred meters from the source
                of activities and for a period lasting up to several weeks or months in duration. In marine waters and well-
                flushed coastal water bodies, this change will be less noticeable due to rapid dilution and dispersion of
                contaminants. Chronic, low-level pollution related to the proposal will occur throughout the 35-year life of the
                proposal. Overall cumulative impacts, which include the effects of non-OCS-related factors (routine point and
                nonpointsource discharges from agriculture, general construction projects, hydromodification,silviculture, septic
                tank leakage, urban runoff and State oil and gas activities) and OCS activities will significantly degrade water
                quality, primarily within the Gulf of Mexico's coastal zone in highly urbanized and industrialized coastal areas.
                Maritime activities are expected to contribute to water quality degradation near ports and major navigation
                channels. In restricted or poorly flushed coastal waterbodies, localized increases in pollutant concentrations
                (nutrients, organic matter, trace metals, organotins, hydrocarbons, etc.) may be severe and persist for months
                or longer. Low dissolved oxygen levels will result in localized hypoxia in the coastal and nearshore waters. As
                indicated above, water quality degradation will be less noticeable in marine waters and well-flushed coastal
                water bodies due to rapid dilution and dispersion of contaminants. Chronic, low-level pollution will continue
                to persist in marine and coastal waters.

                (4) Impacts on Air Quality

                    The Cumulative Analysis considers the impacts from the following factors and/or activities: the proposed
                action, past and future OCS sales, power generation, industrial activities, and transport in the WPA.
                    The scenario discussed in Section IV.A. (Table IV-8) for the Cumulative Case establishes that 5,280
                exploration and delineation wells and 2,050 development wells would be drilled, and 140 platform complexes
                would be emplaced. The sale area has been subdivided into three offshore subareas: W-1, W-2, and W-3
                (Figure IV-1). This discussion analyzes the potential degrading effects of OCS-related activities on air quality









                 IV-500

                 in each subarea. Table IV-8 presents for the Cumulative scenario the numbers of exploration., delineation, and
                 development wells; platforms installed; and service vessel and helicopter trips for each subarea. The following
                 table shows total emissions from wells, platforms, vessels, and other OCS-related activities in the WPA for the
                 Cumulative Case. Observe that NO. is the most emitted pollutant, while SO,, is the leasit emitted. More
                 important is that this information shows that wells and vessels contribute mostly NO,,; plaiforms contribute
                 mostly NO., CO, and VOC. These emissions were calculated by adding the emissions from wells and platform
                 complexes over time. Emissions of vessels were calculated using the total number of service vessel trips
                 presented in Table IV-8.


                                                        Total OCS Emissions in the WPA
                                      (tons over the 35-year life of the proposed action--Cumulative Case)


                     Activi                                      NO            CO             so            THC             TSP

                     Service Vessels                           71,114.8      8,331.2       1,123.6         3,618.9       5,017.1
                     LTO Helicopters                              512.9        414.2           78.9           21.4           19.7
                     Cruise Helicopters                         1,656.9      4,734.0          355.1           385.9        473.4
                     Blowouts without Fire                         0.0            0.0           0.0           24.2           0.0
                     Spills without Fire                           0.0            0.0           0.0           510.0          0.0
                     Barge Loading                                 0.0            0.0           0.0           299.8          0.0
                     Tanker Loading                                0.0            0.0           0.0        3,298.2           0.0
                     Transit Loss                                  0.0            0.0           0.0        2,835.8           0.0
                     Tanker Exhaust                             2,193.3        239.8       2,724.5              3.6        788.2
                     Tug Exhaust                                1,372.0        136.7           17.7           61.8          82.3
                     Exploratory Wells                        50,815.9      13,557.9       5,938.2         1,471.4       5,097.3
                     Development Wells                         14,678.0      3,915.5       1,722.0         74430.5       1,476.0
                     Platforms                               212,752.8      27,713.7          372.2        80,635.2        521.0

                     Totals                                  355,096.6      59,043.0       12,332.2        93,596.7     13,475.0

                     Total emissions for each subarea in the WPA during the Cumulative Case are presented below. Observe
                 that Subareas W-1 and W-2, which are closest to land, generate the largest emissions, while Subarea W-3
                 generates the smallest amounts of all pollutant emissions.

                                                       Total Emissions in WPA Subareas
                                     (tons over the 35-year life of the proposed action--Cumulative Case)

                                     Pollutant              W-1                   W-2                  W-3

                                        NO,,              146,431.6         142,770.8              65,894.2
                                         CO                24,347.6          23,738.9              10,956.4
                                         so.                5,085.4            4,958.3             2,288.4
                                        THC                38,596.6          37,631.7              17,368.5
                                         TSP                5,556.7            5,417.8             2,500.5

                     The total pollutant emissions per year are    not uniform. During the early years of the OCS program
                 activities, emissions would be large and decrease over time as reserves and production decrease. After a
                 maximum, emissions would decrease rapidly as platforms, wells, and service vessel trips decrease to a minimum.
                     The following table presents peak emissions of primary pollutants from OCS programmatic activities in
                 tons per year. It is very important to note that well drilling activities and platform peak emissions are not
                 necessarily simultaneous. However, it is assumed that peak emissions from service vessels and other activities










                                                                                                                        IV-501

               and well and platform peak emissions occur simultaneously. In this analysis the aggregate peak emissions,
               which are generally larger than average emissions, will be employed. Use of peak emissions results in
               conservative impact level estimates from the OCS program activities.

                                                   Mean and Peak Emissions in the WPA
                                                                 (tons/year)


                    Pollutant         Wells        Platforms        Vessels       Others           Mean         Aggregate

                       NO.           4,438.95      8,306.56         2,195.71        0.00         10,145.60        13,304.61
                       CO            1,184.30      1,082.03          395.88         0.00          1,686.94         2,419.68
                       so.            519.05          14.53          122.85         0.00            352.35           628.75
                      THC             128.80       3,148.26          116.90        244.51         2,719.61         3,567.41
                       TSP            445.45          20.34          182.31         0.00            385.00           623.01

                    The mean emissions were computed by dividing the total emissions by the 35-year life of the proposed
               action. Peak emissions from wells and platforms are obtained from their temporal distribution. Platforms and
               wells have the greatest peak emissions, while vessels and other OCS-related activities have smaller emissions.
               This phenomenon is contrary to the emission rates, where wells have greater rates than platforms.
                    The effects of the pollutants considered in this analysis were described in the Base Case analysis and will
               not be repeated here. The reader may consult that section.
                    Because the meteorological conditions described in the Base Case will not change for this analysis, neither
               will they be repeated. The only changes that occur in the Cumulative Case are those related to infrastructures
               and resources. These changes are reflected in an increase of emissions for all analyzed pollutants. A
               comparison of Cumulative Case emissions per year with those of the Base Case shows that these Cumulative
               emissions are 10-15 times greater.
                    To estimate the potential impact of offshore emissions on offshore and onshore air quality, a steady state
               box model was employed (Lyons and Scott, 1990). The model is an expression of mass conservation and
               assumes that pollutants are vertically dispersed and sources uniformly distributed. For the purpose of these
               air quality analyses, an assumption of uniform distribution of average size sources throughout the planning
               areas at this early stage is a reasonable approach. Predominance of unstable atmospheric conditions over the
               sea, as discussed in Section III.A.2., ensures that pollutants are dispersed homogeneously. The model was
               applied to NO,, emissions because these are the largest emissions. Because VOC emissions are not inert, the
               box model cannot be used to assess their impacts on air quality. Concentrations for other pollutants can be
               estimated by multiplying the NO. concentrations by the ratio of the pollutant emissions over the NO. emissions.
               Concentrations of primary pollutants other than NO. would be smaller by more than 75 percent. Impacts from
               VOC and CO will be estimated by comparing the offshore and onshore emission rates.
                    The box model was applied to the following conditions: onshore and offshore winds with speeds ranging
               from 1 to 7 m/s-1, a mean mixing height of 900 m, and a low mixing height of 300 m. During offshore wind
               conditions, impacts to the onshore air quality from offshore WPA emissions are very low because the pollutants
               are transported offshore. Conditions of onshore winds indicate that concentrations reaching land from Subarea
               W-1 varied between 2.42 and 0.26 Agm-3 for speeds from 1 to 7 ms-1 and a mixing height of 900 in; for a 300-m
               mixing height, concentrations varied from 7.26 to 0.77 jjgM-3 under the same wind speeds. Concentrations for
               pollutants other than VOC would be smaller, as indicated above. Impacts to air quality from NO. are low
               because the only ambient concentration near the coastal area is well below the national standard, and the OCS
               contributions will not exceed it. Impacts from CO, SO,, and TSP are low because the concentrations arriving
               onshore do not exceed national standards when these contributions are added to the existing ambient
               concentrations presented in Section III.A.3. for Texas. The MMS regulations (30 CFR 250.44) do not establish
               annual significance levels for CO and VOC. For these pollutants, a comparison of emission rates will be used
               to assess impacts. Formulas to compute the emission rates in tons/yr for CO are 3,400-13213 and 33.3-D for
               VOC. In these formulas, D represents distance in statute miles from the shoreline to the source. The CO










                  IV-502

                  exempt emission level in Subarea W-1 is 15,781.4 tons/yr, which is greater than peak emissioris from the whole
                  WPA_ Therefore, CO impacts on air quality will be low. The exemption emission level of VOC in Subarea
                  W-1 is 333 tons/yr, while the platform emission level is estimated at 30.7 tons/yr. Therefore, VOC impacts to
                  air quality would be low.
                      Transport of pollutants toward onshore areas has a maximum frequency of 85 percent during summer and
                  only 34 percent during winter. Thus, the box model results are very conservative estimates of pollutant
                  contributions to the onshore air quality status. The modeling effort does not consider removal processes such
                  as rain, which in the WPA has a high frequency (Section III.A-2.) and would reduce impactlevels to onshore
                  air quality.
                      The MMS has also studied the impacts of offshore emissions using the OCD Model (USDOI, MMS,
                  1986a). The study was conducted off the Galveston, Brazos, and High Island Areas, Texas, using 250 offshore
                  sources and employing a 300-m mixing height, which coincides with the lower mixing height employed in the
                  box model. The model run in this study represents an aggregation of all sources. The annual arithmetic mean
                  varied between 0.82 and 1.83 pgm-3, which is below the national standard of 100 jLgm-3. All other inert
                  pollutants would have lower concentrations.
                      A recent dispersion analysis of NO. emissions from 47 OCS sources, which included 31 existing sources and
                  16 proposed platforms, along the Texas offshore area was completed (USDOI, MMS, 1991c). Annual average
                  concentrations peaked around 0.08 LgM-3 and the highest 1-hour concentration never exceeded 2.31 jagm-3.
                  These results indicate that OCS contributions to onshore air quality problems are small. Therefore, it is
                  reasonable to assume that mean hourly concentrations derived from emissions associated with OCS program
                  activities (2.42 Agm-3) and spread over 145.3 billion square meters would have a moderate effect
                      Oil-spill effects on air quality are examined below. It is assumed that oil spills in the category,greater than
                  and equal to 50 bbl, or less than 50 bbl, as well as greater than 50 bbI and less than 1,000 bbl, would have low
                  impacts on air quality because their input of pollutants (it is assumed that 50% of the spill evaporates in three
                  days) would be very small. Information from OCS accidents indicates emissions of fewer than 100 tons/hr by
                  the second hour. For spills greater than or equal to 1,000 bbl, emissions are about 285 tons/hr or smaller. If
                  the dispersion of emissions is taken into account, effects on offshore air quality would be temporary.
                      Nearly 12 percent of OCS crude-oil production is offloaded from surface vessels at ports. The
                  unintentional emissions from these offloading operations are estimated to be 3,598 tons, which represent less
                  than 1.1 percent of the total VOC emissions and are considered negligible in the WPA. Towboat emissions
                  in these operations are expected to produce negligible effects on air quality.
                      Suspended particulate matter is important because of its potential in degrading the visibility in national
                  wildlife refuges or recreational parks designated as PSD Class I areas. The impact depends on emission rates
                  and particle size. Particle size'uscd in this analysis represents the equivalent diameter, which is the diameter
                  of a sphere that will have the same settling velocity as the particle. Particle distribution in the atmosphere has
                  been characterized as being largely trimodal (Godish, 1991), with two peaks located at diameters less than 2
                  jam and a third peak with a diameter larger than 2 ILm. Particles with diameters of 2 Am or larger settle very
                  close to the source (residence time of approximately 1/z day, Lyons and Scott, 1990), so their impact on these
                  areas would be low. For particles smaller than 2 /.tm, which do not settle fast, wind transport determines their
                  impacts. Results from the box model indicate that the largest concentration for TSP will be 0.34 AgM-3, which
                  is less than the allowable annual increase level of 5 tLgM-3. Besides, Section III.A.3. indicates that in the coastal
                  areas the suspended particulate matter is around 50 pgm-3 and the national standard is 150 jjgM-3' making the
                  OCS contribution unimportant. Therefore, suspended matter would have a small effect on the visibility of PSD
                  Class I areas.
                      Ozone is of great concern because of its environmental considerations. In the WPA five counties have
                  nonattainment status for this pollutant (Section III.A.3.). Ozone measurements (Texas Air Control Board,
                  1989) in 1988 were discussed in Section III.A.3. and details will not be repeated here. Concentrations at three
                  coastal sites indicate that the national standard was exceeded in two (Houston and the Beaumont-Port Arthur-
                  Brazoria area), and the third was a border case (Corpus Christi). However, impacts from OCS activities cannot
                  be assessed because ozone is not emitted but formed by photochemical processes, which were not modeled in
                  this analysis.










                                                                                                                           IV-503

                    The amount of power generation is very difficult to predict because it depends on many nonquantiflable
                 factors. Therefore, different sets of assumptions result in different estimates. The envelope of predictions
                 shows that energy consumption should increase up to the year 2010; after this, predictions show more variation
                 but generally indicate an increase of energy consumption. Because energy production is the largest single
                 pollutant generator, it is safe to assume that emissions must also increase (USDOE, 1990). However, advances
                 in control technology and the use of alternative energy sources can change the correlation between energy
                 production and emissions. The available information (USDOE, 1990) indicates that SO., emissions from energy
                 generation decreased 16.4 percent between 1970 and 1987. Other pollutants that showed a decrease over the
                 1970-1987 period are particulate matter and NO, Although CO and VOC increased over the same period,
                 the overall amount of emitted pollutants decreased.
                    Emissions of the primary pollutants related to industrial activities decreased over the 1970-1987 period.
                 The reduction in the total amount of pollutants was 51 percent (Godish, 1991). The projected increase in
                 employment (Section III.C.2.) can be interpreted as an increase of industrial activities. However, if the
                 decreasing trend of emissions holds during the next 35 years, it is safe to assume that industrial emissions would
                 not increase; or, at worst, they would remain at the present levels.
                    Transportation-related emissions are an important consideration in regard to inshore air quality because
                 vehicles constitute the second largest emitters of S02 and NO. and the largest source of carbon monoxide
                 (USDOE, 1990). Emissions of particulate matter and SO. increased, while NO,, emissions remained the same
                 over the 1970-1987 period. Emissions of CO and hydrocarbons decreased over the same period. The overall
                 emissions showed a reduction of almost 44 percent during the 1970-1987 period (Godish, 1991). Vehicular use
                 is population-dependent and the demographic trends through most of the 1980's have shown a population
                 decrease in most Gulf Coast States. A recent projection for MMS (Section III.C.2.) indicates that this trend
                 will be reversed, and population will increase. Thus, vehicular use will increase, but as the consequence of
                 advances in fuel efficiency, alternative gasoline developments, and better emission controls, emissions will
                 probably decrease or, at worse, remain at the same level.
                    Blowouts are accidents related to OCS activities and are defined as an uncontrolled flow of fluids from a
                 wellhead or wellbore. In the Gulf of Mexico OCS there have been 116 blowouts over a period of 19 years
                 (1971-1989) (Section IV.A-4.b.(4)). This represents an average of about 5 blowouts per year, but the number
                 of wells drilled is a better indicator. The estimated number of blowouts, at a rate of 7 blowouts per 1,000 wells
                 drilled, is 74 blowouts during the Cumulative Scenario in the WPA_ The air pollutant emissions from blowouts
                 depend on the amount of oil and gas released, the duration of the accident, and the occurrence or not of fire
                 during the blowout
                     Because of technological advances the duration of blowouts has decreased, and about 61 percent of recent
                 blowouts last 1 day or less, 19 percent last between 2 and 3 days, 7 percent last between 4 and 7 days, and 13
                 percent last more than 7 days (Fleury, 1983). Further, most blowouts occurred without fire (MMS Database).
                 The amount of oil released during these accidents has been small. The total emission of THC is 1,614 tons
                 over the Cumulative scenario. It must be remembered that these are conservative estimates and that the total
                 amount of THC may be less; the VOC will also be less because it is a fraction of the THC.
                     State oil and gas production occurs in State waters off Texas. These platforms also release air pollutant
                 emissions that cause impacts to the onshore air quality. The latest information that MMS has regarding the
                 Texas oil and gas industry indicates that about 86 production platforms and about 15 drilling rigs exist in State
                 waters. Assuming that these facilities are similar to those used in the OCS offshore waters, an estimate of their
                 emissions can be made. The 86 platforms represent about 18 percent of the platforms available in the OCS
                 Program for the WPA. The NO,, emissions that these facilities will contribute to the onshore areas is estimated
                 as 2,359 tons during the peak year and also decre"ing in time. Thus, the total concentrations arriving onshore
                 from OCS and State activities are about 20 percent underestimated because they do not include the State
                 emissions. However, MMS still needs better information regarding these activities to make any assessment of
                 these activities.










                  IV-504

                  Sunimaty

                       The scenario discussed in Section IV.A. (Table IV-13) for the Cumulative Case establishes that 5,280
                  exploration and delineation wells and 2,050 development wells would be drilled and that 140 platform
                  complexes would be emplaced. This is in addition to the 1,106 platforms that were considered as sources in
                  this analysis. These latter sources exist as a result of past sales. It is also assumed that power generation,
                  transportation, and industry will cause enough emissions to keep the present impact at their actual levels.
                  Maintenance of the present impact levels is due to the continuation of actual trends in energy consumption
                  or technological developments in fuel and motor efficiency.
                      The incremental contribution of the proposeclaction (as analyzed in Section IV.13.2.a.(4)), to the cumulative
                  impacts is low because of the prevailing atmospheric conditions and mixing heights affecting the transport and
                  dispersion of emissions, and the concentrations of pollutants reaching the onshore areas.

                  Conclusion

                      Emissions of pollutants into the atmosphere from activities assumed for the OCS Program within the WPA
                  are expected to have concentrations that would not change the onshore air quality classifications. Increases
                  in onshore concentrations of air pollutants from the proposed action are estimated to be about 1 Agrn-3 (box
                  model steady concentrations). This concentration will have minimal impacts during winter, because onshore
                  winds occur only about 34 percent of the time, and maximum impacts in summer, when onshore winds occur
                  85 percent of the time.

                  (5) Impacts on Marine Mammals

                  (a) Nonendangered and Nonthreatened Species

                      This Cumulative Analysis considers the effects of impact-producing factors related to the Western Gulf
                  proposed action, prior and future OCS sales, State oil and gas activity, commercial fishing, removal of live
                  specimens for public display, and pathogens that may occur and adversely affect noliendangered and
                  nonthreatened cetaceans; in the same general area that may be affected by OCS oil and gas activity located in
                  the WPA_
                      Sections providing supportive material for the nonendangeredand nonthreatenedcetacean analysis include
                  III.B.3. (description of cetaceans), IV.A-2.a.(I) (seismic operations), IV.A-2.a.(3) (structure removal), IV.A-2.c.
                  (support activities), IV.A.2.d.(5) (offshore discharges), IV.C.l. and 3. (oil spills), and IV.C.5. (oil-spill response
                  activities).
                      An estimated 5.2 MM bbI of drilling muds, 1.3 MMbbl of drill cuttings, and 2.5 BbbI of produced waters
                  are assumed to be generated offshore as a result of the proposed action plus prior and future OCS sales.
                  These effluents are routinely discharged into offshore marine waters and are regulated by the U.S.
                  Environmental Protection Agency's NPDES permits. An unknown but expected substantial amount would also
                  be discharged into nearshore waters from State oil and gas activities. It is expected that nonendangered
                  cetaceans will periodically interact with these discharges. Direct effects to cetaceans art-, expected to be
                  sublethal, and effects to cetacean food sources are not expected due to the rapid offshore dilution and
                  dispersion of operational discharges. It is expected that operational discharges will periodically contact and
                  affect nonendangered cetaceans.
                     It is assumed that helicopter traffic will occur on a regular basis, averaging about 135,000 trips per year.
                  The FAA Advisory Circular 91-36C encourages the use of fixed-wing aircraft above an elevation of 152 in and
                  helicopters above 300 in. It is expected that at these elevations no cetaceans will be affected by OCS helicopter
                  traffic. It is expected that helicopter traffic will rarely disturb and affect nonendangered cetaceans because of
                  special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 in.
                     It is assumed that, during the peak year, 12,000 OCS-related oil/gas service-vessel trips, .33 shuttle tanker
                  trips, and 26 barge traffic trips will occur as a result of the proposed action, plus prior and future OCS sales











                                                                                                                            IV-505

                in the WPA (Table IV-8). Noise from service-vessel traffic may elicit a startle reaction from cetaceans or mask
                their sound reception. This effect is sublethal and, at worst, of a short-term, temporary nature. Service vessels
                could collide with and directly impact cetaceans, but due to dolphin maneuverability and echo-location,
                encounters of this type are extremely rare. Cetaceans can avoid service vessels, and operators can avoid
                cetaceans. It is expected that service-vessel traffic will rarely contact and affect nonendangered cetaceans.
                     It is assumed that, during the peak year, 385 exploration and delineation wells and 100 development wells
                will be drilled as a result of the proposed action, plus prior and future OCS sales in the WPA (Table IV-8),
                and will produce sounds at intensities and frequencies that could be heard by cetaceans. It is estimated that
                noise from drilling activities will last no longer than two months at each location. However, the decibel level
                of these sounds dissipates to the tolerance of most cetaceans within 15 m of the source. Odontocetes
                communicate at higher frequencies than the dominant sounds generated by drilling platforms. Sound levels
                in this range are not likely to be generated by drilling operations (Gales, 1982). The effects on cetaceans from
                platform noise are expected to be sublethal. It is expected that drilling noise will rarely disturb and affect
                nonendangered cetaceans.
                     Explosive platform removals can temporarily interfere with communication, disturb behavior, permanently
                reduce hearing sensitivity, or cause hemorrhaging in cetaceans. It is estimated that 231 production platforms
                will be removed by explosives from the WPA as a result of the proposed action, plus prior and future OCS
                sales. It is assumed that these removals will occur during the last 12 years of the life of the proposed action,
                with no more than 12 in any given year. It is expected that structure removals will cause sublethal effects on
                cetaceans. No mortalities are expected because of the MMS guidelines for explosive removals (USDOI, MMS,
                1990a, Appendix B). It is expected that structure removals will periodically disturb and affect nonendangered
                cetaceans.
                     Seismic surveys use airguns to generate pulses. It is assumed that only this method will be used in seismic
                surveys as a result of the proposed action, plus prior and future OCS sales. It is expected that effects on
                cetaceans from seismic surveys are primarily sublethal, constituting short-term avoidance behavior.
                     Oil spills can adversely affect cetaceans, causing skin and eye irritation, asphyxiation from inhalation of
                toxic fumes, food reduction or contamination, oil ingestion, and displacement from preferred habitats or
                migration routes. In the event that oiling of cetaceans should occur from oil spills greater than or equal to
                1,000 bbl, the effects would primarily be sublethal; few mortalities are assumed. The effects of oil spills less
                than 1,000 bbl are assumed to be solely sublethal due to the inconsiderable area affected and their rapid
                dispersion. It is assumed that the extent and severity of effects from oil spills of any size will be lessened by
                improved coastal oil-spill contingency planning (Section IV.C.5.) and by active avoidance of oil spills by
                cetaceans.
                     Section W.C.I. estimates the mean number of spills less than 1,000 bbl occurring as a result of the
                proposed action, plus prior and future OCS sales in the WPA. It is assumed that 5 offshore spills greater than
                1 and less than or equal to 50 bbl will occur each year and that none will contact land. It is assumed that I
                spill greater than 50 and less than 1,000 bbl will occur every 5 years and that none will contact land. No spills
                less than 1,000 bbl are assumed to occur and contact nearshore areas. Although an interaction with spills less
                than 1,000 bbl is assumed, only sublethal effects are assumed. It is estimated that spills less than 1,000 bbl will
                periodically contact and affect nonendangered cetaceans.
                     It is assumed that 39 crude oil spills greater than or equal to 1,000 bbl will occur as a result of import
                tankering and the proposed action, plus prior and future OCS sales in the Gulf of Mexico (Table IV-22).
                Section IV.C.1. identifies the assumed risk of one or more oil spills greater than or equal to 1,000 bbl occurring
                and contacting areas within 10 days where cetaceans have been surveyed. There is a 71 percent probability
                from import tankering and a 30 percent probability from the OCS program that an oil spill will occur and
                contact cetacean habitats at or beyond the shelf break of the WPA. There is a 22 percent probability that an
                oil spill greater than or equal to 1,000 bbl will occur and contact coastal areas of Texas where cetaceans have
                been sighted. Although an interaction with spills grater than or equal to 1,000 bbl is assumed, primarily
                sublethal effects are assumed with infrequent mortalities. It is assumed that an oil spill greater than or equal
                to 1,000 bbl will periodically contact and affect nonendangered cetaceans in the WPA.
                     Commercial fishing equipment entangles and drowns cetaceans during routine activities or during accidental
                "ghost" fishing by lost or discarded gear (Tucker & Associates, Inc., 1990). Although the extent of incidental










                  IV-506

                  take and death during "ghost" fishing is largely undocumented, it has been noted as an activity of concern by
                  the NMFS and the Marine Mammal Commission. It is expected that both routine commercial and accidental
                  "ghost" fishing will cause few mortalities of cetaceans. It is expected that commercial fishing equipment will
                  periodically contact and affect nonendangered cetaceans in the WPA.
                      Nonendangered and nonthreatened cetaceans; are captured and removed for public display and research.
                  These activities are concentrated on bottlenose dolphins, and not all endeavors are successful. Dolphins
                  occasionally elude capture or escape during acquisition. Catch quotas are set by the NIVFS to ensure a
                  sustainable yield, and capture is occasionally banned if populations are considered depleted. It is assumed that
                  bottlenose dolphins will be captured and removed from the WPA_ The effects on those dolphins that elude
                  or escape capture are expected to be sublethal. It is expected that live capture and removalwill rarely contact
                  and affect nonendangered cetaceans in the WPA.
                      Epidemic die-offs or mass strandings occur in several species of nonendangered cetaceans. The causes are
                  difficult to diagnose, as has been the case with abnormal bottlenose dolphin mortality in the Gulf in 1989-1990
                  and along the Atlantic Seaboard in 1988 (USDOC, NMFS, 1990b). Naturally occurring and anthropogenic
                  toxins have been the hypothesized cause. Sources include algal blooms, oil spills, ocean clumping, industrial
                  and municipal effluents, and agricultural runoff. These concentrations are not widespread, and mortalities
                  occur in localized populations. It is expected that toxins will periodically contact and affect nonendangered
                  cetaceans in the WPA.


                  Summary

                      Activities resulting from the Cumulative scenario have a potential to affect nonenclangered cetaceans;
                  detrimentally. These cetaceans could be impacted by operational discharges, helicopter and vessel traffic,
                  platform noise, explosive platform removals, seismic surveys, oil spills, commercial fLshing, capture and removal,
                  and pathogens. The effects of the majority of these activities are estimated to be sublethal. Lethal effects are
                  assumed only from oil spills greater than or equal to 1,000 bbl, commercial ffihing, and pathogens. Off spills
                  of any size as a result of import tankering, the proposed action, and prior and future OCS sales are estimated
                  to be infrequent events that will periodically contact nonenclangered and nonthreatened cetaceans.
                      The incremental contribution of the proposed action (as analyzed in Section IV.D.2.a.(5)(a)) to the
                  cumulative impact is inconsequential because the effects of sale-specific operational discharges, helicopter and
                  service-vessel traffic, and seismic activity are estimated to be sublethal. No mortalities are expected from
                  explosive platform removal because of MMS guidelines. It is assumed that there will be no interaction between
                  sale-related oil spills and nonenclangered and nonthreatened cetaceans.

                  Conclusion


                      The impact of the Cumulative Case scenario on nonenclangered and nonthreatened cetaceans within the
                  potentially affected area is assumed to result in a decline in species numbers or temporary displacement from
                  their current distribution, a decline or displacement that will last more than one generation.

                  (b) Endangered and Threatened Species

                      This Cumulative Analysis considers the effects of activities related to the Western Gulf'proposed action,
                  prior and future OCS sales, State oil and gas operations, migration, and recreational whale-watching on the
                  blue, sei, humpback, fin, and sperm whale. The sperm whale is the species most seen in the Gulf of Mexico.
                      The major impact-producing factors are described in the preceding section (Section IV.13.2.e.(5)(a),
                  nonendangered and nonthreatened species). Sections providing supportive material for the endangered
                  cetacean analysis include III.B.3. (description of cetaceans), IV.A.2.a.(l) (seismic operations), IV.A-2.a.(3)
                  (structure removal), IV.A.2.c. (support activities), IV.A2.d.(5) (offshore discharges and noise emissions), IV.C.3.
                  (oil spills), and IV.C.5. (oil-spill response activities).










                                                                                                                         IV-507

                   An estimated 5.2 MMbbI of drilling muds, 1.3 MMbbI of drill cuttings, and 2.5 BbbI of produced waters
              are assumed to be discharged annually as a result of the proposed action plus prior and future OCS sales.
              These effluents are routinely discharged into offshore marine waters and are regulated by the U.S.
              Environmental Protection Agency's NPDES permits. An unknown but expected substantial amount would also
              be discharged into nearshore waters from State oil and gas activities. It is estimated that endangered cetaceans
              will periodically interact with these discharges. Direct effects to cetaceans are expected to be sublethal and
              effects to cetacean food sources are not expected due to the rapid offshore dilution and dispersion of
              operational discharges. It is expected that operational discharges will periodically contact and affect
              endangered cetaceans.
                   It is assumed that helicopter traffic will occur on a regular basis, averaging about 133,000 trips per year.
              The FAA Advisory Circular 91-36C encourages the use of fixed-wing aircraft above an elevation of 152 rn and
              helicopters above 300 m. It is estimated that at these elevations no cetaceans will be affected by OCS
              helicopter traffic. It is expected that helicopter traffic will rarely disturb and affect endangered cetaceans
              because of special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 m.
                   It is assumed that, during the peak year, 12,000 OCS-related oil/gas service-vessel trips, 33 shuttle tanker
              trips, and 26 barge traffic trips will occur as a result of the proposed action, plus prior and future OCS sales
              in the WPA (Table IV-8). Noise from service vessel traffic may elicit a startle reaction from cetaceans or mask
              their sound reception. This effect is sublethal and, at worst, of a short-term, temporary nature. Service vessels
              could collide with and directly impact cetaceans, but due to dolphin maneuverability and echo-location,
              encounters of this type are extremely rare. Cetaceans can avoid service vessels and operators can avoid
              cetaceans. It is expected that service vessel traffic will rarely contact and affect endangered cetaceans.
                   It is assumed that, during the peak year, 385 exploration and delineation wells and 100 development wells
              will be drilled as a result of the proposed action, plus prior and future OCS sales in the WPA (Table IV-8),
              and will produce sounds at intensities and frequencies that could be heard by cetaceans. It is estimated that
              noise from drilling activities will last no longer than two months at each location. However, the decibel level
              of these sounds dissipates to the tolerance of most cetaceans; within 15 m of the source. Odontocetes
              communicate at higher frequencies than the dominant sounds generated by drilling platforms. Sound levels
              in this range are not likely to be generated by drilling operations (Gales, 1982). The effects on cetaceans; from
              platform noise is expected to be sublethal. It is expected that drilling noise will rarely disturb and affect
              endangered cetaceans.
                   Explosive platform removals can temporarily interfere with communication, disturb behavior, permanently
              reduce hearing sensitivity, or cause hemorrhaging in cetaceans. It is assumed that 231 production platforms
              will be removed by explosives from the WPA as a result of the proposed action plus, prior and future OCS
              sales. It is assumed that these removals will occur during the last 12 years of the life of the proposed action
              and that no more than 12 are likely to occur in any single year. It is expected that structure removals will cause
              sublethal effects on cetaceans. No mortalities are expected because of the MMS guidelines for explosive
              removals (USDOI, MMS, 1990a, Appendix B). It is expected that structure removals will periodically disturb
              and affect endangered cetaceans.
                   Seismic surveys use airguns, to generate pulses. It is assumed that only these methods will be used in
              seismic surveys as a result of the proposed action, plus prior and future OCS sales (Section IV.A.2.). It is
              expected that effects on cetaceans from seismic surveys are primarily sublethal constituting short-term
              avoidance behavior.
                   Oil spills can adversely affect cetaceans, causing skin and eye irritation, asphyxiation from inhalation of
              toxic fumes, food reduction or contamination, oil ingestion, and displacement from preferred habitats or
              migration routes. In the event that oiling of cetaceans should occur from oil spills greater than or equal to
              1,000 bbl, the effects would primarily be sublethal, few mortalities are assumed. The effects of off spills less
              than 1,000 bbl are assumed to be solely sublethal due to the inconsiderable area affected and their rapid
              dispersion. It is assumed that the extent and severity of effects from oil spills of any size will be lessened by
              improved coastal oil-spill contingency planning (Section W.C.S.) and by active avoidance of oil spills by
              cetaceans.
                   Section IV.C.I. estimates the mean number of spills less than 1,000 bbl occurring as a result of the
              proposed action, plus prior and future OCS sales in the WPA. It is assumed that 5 offshore spills greater than










                   IV-508

                   I and less than or equal to 50 bbl will occur each year and that none will contact land. It is assumed that 1
                   spill greater than 50 and less than 1,000 bbl will occur every 5 years and that none will contact land. Although
                   an interaction with spills less than 1,000 bbl is assumed, only sublethal effects are assumed. It is expected that
                   spills less than 1,000 bbl will periodically contact and affect endangered cetaceans.                          I
                       It is assumed that 39 crude oil spills greater than or equal to 1,000 bbl will occur as a result of import
                   tankering and the proposed action, plus prior and future OCS sales in the Gulf of Mexico (Table IV-22).
                   Section IV.C.3. identifies the assumed risk of one or more oil spills greater than or equal to 1,000 bbl occurring,
                   and contacting areas within 10 days where cetaceans have been surveyed. There is a 71 percent probability.
                   from import tankering and a 30 percent probability from the OCS Program that an oil spill greater than or
                   equal to 1,000 bbl will occur and contact cetacean habitats at or beyond the shelf break of the WPA_ There
                   is a 22 percent probability that an oil spill greater than or equal to will occur and contact coastal areas of Texas
                   where cetaceans have been sighted. Although an interaction with spills greater than or equal to 1,000 bbl is
                   assumed, primarily sublethal effects are expected, with infrequent mortalities. It is expected that an oil spill
                   greater than 1,000 bbl will periodically contact and affect endangered cetaceans in the WPA_
                       It is assumed that the migratory behavior of the great whales exposes them to potential adverse impacts
                   generated from all Gulf of Mexico and Atlantic OCS planning areas, as well as routine activities and accidental.
                   events originating from Western America, North America, Europe, and the Caribbean. The incremental
                   contribution of each impact cannot be determined nor its effect estimated because of the multitude of sources.
                        Recreational whale-watching is an applicable impact-producing factor only to large cetaceans and great
                   whales. Although whale-watching vessels have the potential to displace or collide with whales, no incidents of'
                   this nature have been reported. These activities are not popular in the Gulf; however, it is assumed that they
                   regularly occur on the Eastern Seaboard. It is assumed that these activities cause sublethal effects. It is
                   estimated that recreational whale-watching activities rarely contact and affect great whales that migrate to the
                   WPA.


                   Summary

                      Activities resulting from the Cumulative scenario have a potential to affect endangered and threatened
                   cetaceans detrimentally. These cetaceans could be impacted by operational discharges, helicopter and vessel
                   traffic, platform noise, explosive platform removals, seismic surveys, oil spills, oil-spill response operations,
                   natural and anthropogenic activities contacted during migration, and recreational whale-watching. The effects
                   of the majority of these activities are estimated to be sublethal. Lethal effects are estimated only from oil spills
                   greater than or equal to 1,000 bbl. Oil spills of any size as a result of import tankering, the proposed action,
                   and prior and future OCS sales are estimated to be infrequent events that will periodically contact endangered
                   cetaceans.
                      The incremental contribution of the proposed action (as analyzed in Section IV.131.a.(5)(b)) to the
                   cumulative impact is inconsequential because the effects of sale-specific operational discharges, helicopter and
                   service-vessel traffic, and seismic activity are estimated to be sublethal. No mortalities are assumed from
                   explosive platform removal because of MMS guidelines. It is assumed that there will be no interaction between
                   sale-related oil spills and endangered and threatened cetaceans.

                   Conclusion


                      The impact of the Cumulative Case scenario on endangered and threatened cetaceans within the
                   potentially affected area is assumed to result in a decline in species numbers or temporary displacement from
                   their current distribution, a decline or displacement that will last more than one generation.

                   (6) Impacts on Marine Turtks

                      This Cumulative Analysis considers the effects of impact-producing factors related to the Western Gulf
                   proposed action, prior and future OCS sales, State oil and gas activity, migration, dredge-aind-fill operations,










                                                                                                                              IV-509

                 natural catastrophe, pollution, commercial fishing, hopper dredge operation, recreational boat traffic, and
                 human consumption on the loggerhead, Kemp's ridley, hawksbill, green, and leatherback marine turtles.
                     The effects from the major impact-producing factors are discussed in detail in Section IV.13.2.a.(6), and
                 described below. Sections providing supportive material for the marine turtle analysis include III.A.2.
                 (meteorological conditions), III.B.4. (description of marine turtles), IV.A-2.a.(3) (structure removal), [email protected].
                 (support activities), IV.A.2.d.(5) (offshore discharges), W.B.I.c. (other major coastal/onshore activities), W.C.I.
                 and 3. (oil spills), and IV.C.5. (oil-spill response activities).
                     Anchoring, structure installation, pipeline placement, dredging, and operational discharges as a result of
                 the proposed action, plus prior and future OCS sales, may adversely affect marine turtle habitat through
                 destruction of nearshore wetland areas and live-bottom communities. The impact to such habitats under the
                 Cumulative Case scenario from the above activities is analyzed in detail in Sections IV.D.1.d.a.(1) and (2).
                     To summarize the effects on wetlands and estuaries, it is assumed that 500 ha of coastal areas will be
                 affected by oil spills as a result of the proposed action, prior and future OCS sales, and State oil and gas
                 activities. An estimated dieback of up to 50 ha of wetlands, mainly along the Texas and Louisiana coasts, will
                 occur for several growing seasons from contact with spilled oil. Up to 80 ha of wetlands could be eroded as
                 a result of maintenance dredging and deepening of navigation channels in coastal Texas. Three new pipeline
                 landfalls will affect a total of 16 ha of wetlands in Matagorda, Calhoun, and Nueces Counties in Texas. The
                 main causes of wetland and estuary loss within the Gulf of Mexico are sediment deprivation and rapid coastal
                 submergence.
                     To summarize the effects on nesting beaches, it is assumed that minor changes in beach profiles will occur
                 as a result of oil-spill cleanup operations that remove some sand from the littoral zone. Prespill configurations
                 are assumed to be reestablished within 2-4 months. Recreational use of accessible beaches near large
                 population centers, such as in Texas, will result in damage to beach features. The main causes of nesting beach
                 loss within the Gulf of Mexico are the reduction in sediment being delivered to the coastal littoral system, rapid
                 rate of relative sea level rise, and continued coastal urbanization. To summarize the effects on seafloor
                 habitats, little or no damage is expected to the physical integrity, species diversity, or biological productivity of
                 topographic features. Small areas of 5-10 M2 Would be affected for less than two years, probably on the order
                 of four weeks. However, damage is expected to one or more components of physical integrity, species diversity,
                 or biological productivity in the regionally common habitats or the communities of live-bottom areas. Fewer
                 than five live-bottom areas of 5-10 m2 would be affected for 10 years. Offshore operational discharges are not
                 lethal to marine turtles and are diluted and dispersed rapidly within 1 kin of the discharge point to the extent
                 that adverse effects to marine turtle food sources do not occur (API, 1989; NRC, 1983). It is expected that
                 effects on marine turtles from anchoring, structure installation, pipeline emplacement, and dredging will be
                 indistinguishable from the long-term (25-50 years) natural variability within populations of marine turtles. It
                 is expected that marine turtles will avoid 5-10 m2 of topographic feature areas for up to a month and that this
                 avoidance of impoverished foraging areas will have no effect on marine turtles. It is expected that marine
                 turtles will avoid 5-10 m2 of live-bottom areas for up to 10 years and that this avoidance of impoverished
                 foraging areas will have no effect on marine turtles. The suspended particulate matter in operational
                 discharges offshore is expected to cause sublethal effects by inhibition of the ability of marine turtles to locate
                 their prey visually within 1 kni of the discharge point for the short time period (less than one hour) spent
                 traversing the plume.
                     Sublethal effects on marine turtles or their habitats are expected from these impact-producing factors. The
                 expectation is that anchoring, structure installation, pipeline placement, dredging, and operational discharges
                 will periodically contact marine turtles or their habitats.
                     Marine turtles can become entangled in or ingest trash and debris, which may result in injury or mortality.
                 It is assumed that some OCS-related trash and debris will be accidentally lost into the Gulf of Mexico and
                 available for interaction with marine turtles. Although mortalities could occur, primarily sublethal effects are
                 expected. It is expected that OCS oil- and gas-related trash and debris will rarely interact with and affect
                 marine turtles.
                     Explosive platform removals can cause capillary damage, disorientation, loss of motor control, and fatal
                 injuries in marine turtles. It is assumed that 231 production platforms will be removed by explosives from the
                 WPA as a result of the proposed action, plus prior and future OCS sales. It is assumed that these removals










                   IV-510

                   will occur during the last 12 years of the life of the proposed action with no more than 12 in any single year
                   and that some of the platform removals will occur beyond the continental shelf. As benthic feeders, Gulf of
                   Mexico hard-shell marine turtles do not use habitats beyond the shelf break. Although the pelagic life stages
                   of all marine turtles use these habitats, there is no correlation between marine turtles and the presence of
                   offshore structures beyond the shelf break. It is expected that structure removals will cause sublethal effects
                   on marine turtles. No mortalities are expected because of the MMS guidelines for explosive removals (USDOI,
                   MMS, 1990a, Appendix B) and because the removals occur away from preferred offshore habitats. It is
                   expected that structure removals will rarely disturb and affect marine turtles.
                       It is assumed that, during the peak year of the proposed action, 12,000 OCS-related oil and gas service-
                   vessel trips, 33 shuttle tanker trips, and 26 barge trips will occur in the WPA as a result of the. proposed action,
                   plus prior and future OCS sales (Table IV-8). Noise from service-vessel traffic may elicit a startle reaction
                   from marine turtles. This effect is sublethal and, at worst, of a short-term, temporary nature (NRC, 1990).
                   Collision between service vessels and surfaced marine turtles would likely cause fatal injuries. It is assumed
                   that service-vessel traffic and marine turtles will infrequently be in close proximity. Although a low percentage
                   of stranded marine turtles have shown indications of vessel collision, it cannot be deterniftied what types of
                   vessel were involved and whether these injuries occurred before or after death. Marine turtles are known to
                   spend 4 percent or legs of their time at the surface and to sound when large vessels approach. In addition,
                   marine vessel operators can avoid marine turtles. It is expected that service-vessel traffic will rarely contact
                   and affect marine turtles.
                       Oil spills and oil-spill response activities can adversely affect marine turtles by toxic external contact, toxic
                   ingestion or blockage of the digestive tract, asphyxiation, entrapment in tar or oil slicks, habitat destruction,
                   and displacement from preferred habitats. Oil-spill response activities, such as vehicular and. vessel traffic, are
                   assumed to contact marine turtle habitat, such as shallow areas of turtle grass beds and live-bottom
                   communities, in the event of contact with an oil spill greater than or equal to 1,000 bbl. Sublethal effects are
                   assumed due to the particular consideration these areas receive during oil-spill cleanup to minimize adverse
                   effects from traffic during cleanup activities and to maximize protection efforts to prevent contact of these areas
                   with spilled oil. It is assumed that oil-spill response activities will rarely contact and affect marine turtle habitat.
                       In the event that oiling of marine turtles should occur from oil spills greater than or equal to 1,000 bbl,
                   the effects would primarily be sublethal; few mortalities are assumed. The effects of oil spills less than 1,000
                   bbl are assumed to be solely sublethal due to the inconsiderable area affected and their rapid dispersion. It
                   is assumed that the extent and severity of effects from oil spills of any size will be lessened by improved coastal
                   oil spill contingency planning (Section IV.C.5.).
                       Section IV.C.I. estimates the mean number of spills less than 1,000 bbl occurring as a result of the
                   proposed action plus, prior and future OCS sales in the WPA_ It is assumed that 5 offshorespills greater than
                   1 and less than or equal to 50 bbl will occur each year and that none will contact land. It is assumed that 1
                   spill greater than 50 and less than 1,000 bbl will occur every 5 years and that none will contact land. No spills
                   less than 1,00 bbl are assumed to occur and contact nearshore areas. Although an interaction with spills less
                   than 1,000 bbl is assumed, only sublethal effects are assumed. It is, estimated that spills less than 1,000 bbl will
                   periodically contact and affect marine turtles.
                       It is assumed that 39 crude oil spills greater than or equal to 1,000 bbl will occur as a result of import
                   tankering and the proposed action, plus prior and future OCS sales in the Gulf of Mexico (Table IV-22).
                   Section IV.C.1. identifies the assumed risk of one or more oil spills greater than or equal to 1,000 bbl occurring
                   and contacting marine turtle habitat within 10 days. There is a 22 percent probability from import tankering
                   and an 8 percent probability from the OCS program that an oil spill greater than or equall to 1,000 bbl will
                   occur and contact marine turtle habitats in nearshore areas of the WPA. There is an 85 percent probability
                   that an oil spill greater than or equal to 1,000 bbl will occur and contact within 10 days pelagic turtle habitat
                   beyond the shelf break of the WPA. Although an interaction with spills greater than or equal to 1,000 bbl is
                   expected, primarily sublethal effects are assumed with infrequent mortalities. It is estimated that an oil spill
                   greater than or equal to 1,000 bbl will periodically contact and affect nonendangered cetaceans in the WPA_
                       Non-OCS operations, such as dredge and fill operations, pollution, and natural catastrophes, can cause the
                   loss of marine turtles habitats, e.g., nesting beaches, nearshore wetland areas, and live-bottom communities.










                                                                                                                             IV-511

                 Non-OCS operations such as commercial fishing, hopper dredge activities, nearshore boat traffic, human
                 consumption, and loss of anthropogenic debris can directly impact marine turtles.
                    Dredge-and-fill activities occur throughout the nearshore areas of the United States. They range in scope
                 from propeller dredging by recreational boats to large-scale navigation dredging and fill for land reclamation.
                 Pollution resulting in loss of turtle grass beds includes the alteration of salinity, as in Florida Bay, as well as
                 man-induced increases in turbidity, witnessed in Tampa Bay. Disturbances to nesting beaches occur from a
                 variety of sources, including construction, vehicle traffic, and deprivation of sand. Natural catastrophes,
                 including storms, floods, droughts, and hurricanes, can result in substantial damage to sea turtle habitat.
                 Sublethal effects on marine turtles are expected from these activities. It is expected that dredge-and-fill
                 activities, pollution, and natural catastrophes will periodically contact and affect marine turtle habitats.
                    Drowning that results from forced submergence in commercial fishing trawls has a substantial effect on
                 marine turtle populations in the Gulf of Mexico. Shrimp trawling in the southeastern United States has
                 received extensive scrutiny because of its incidental catch of marine turtles. The National Research Council
                 (1990) has identified shrimp trawling as the greatest cause of human-induced mortality in marine turtles. The
                 use of turtle excluder devices is legislatively mandated in order to decrease losses. Dismemberment of turtles
                 by hopper dredging has resulted in turtle mortalities. Specific dredging projects include the Canaveral Ship
                 Channel in Florida, the King's Bay Submarine Channel in Georgia, and channel dredging of ports throughout
                 the Gulf. Data from the Sea Turtle Stranding Network indicate a large number of marine turtles are hit by
                 boats. In the Eastern Gulf, the incidence of stranded marine turtles exhibiting indications of vessel collision
                 has been related to the volume of recreational boat traffic. However, the number of mortalities caused by
                 collisions is unknown. The human consumption of turtle eggs, meat, or by-products occurs worldwide (Mack
                 and Duplaix, 1979; Cato et al., 1978). Human use is probably substantial, but the frequently illegal nature of
                 the activity generates unreliable estimates of mortality. In addition to the incremental amount of trash and
                 debris generated by the proposed action, plus prior and future OCS sales, trash and debris that could affect
                 marine turtles find their way into the Gulf of Mexico from both commercial and recreational endeavors in the
                 Gulf of Mexico, South and Central America, and North Africa. The volume of marine debris from these
                 sources is unknown (USDOC, NMFS, 1989b; Heneman and the Center for Environmental Education, 1988).
                 Both mortalities and sublethal effects on marine turtles are expected from these activities. It is expected that
                 hopper dredge activities, nearshore boat traffic, human consumption, and loss of anthropogenic debris will
                 periodically contact and affect marine turtles.
                     It is assumed that the migratory behavior of marine turtles exposes them to potential adverse impacts
                 generated from all Gulf of Mexico and Atlantic OCS planning areas, as well as routine and accidental events
                 originating from Central America, North America, Europe, and the Caribbean. The incremental contribution
                 of each impact cannot be determined, nor its effect estimated, because of the multitude of sources.

                 Summary

                     Activities resulting from the Cumulative scenario have a potential to affect marine turtles detrimentally.
                 Those activities include anchoring, structure installation, pipeline placement, dredging, operational discharges,
                 loss of trash and debris, explosive platform removals, vessel traffic, oil-spill response operations, oil spills,
                 dredge-and-fill operations, pollution, natural catastrophes, commercial fishing, hopper dredge operations,
                 recreational boat traffic, human consumption, and natural and anthropogenic activities contacted during
                 migration. The effects of the majority of these activities are estimated to be sublethal. Lethal effects are
                 expected from ingestion of trash and debris, off spills greater than or equal to 1,000 bbl, commercial fishing,
                 hopper dredge operations, and human consumption. Off spills of any size as a result of import tankering, the
                 proposed action, and prior and future OCS sales are estimated to be infrequent events that will periodically
                 contact endangered cetaceans.
                     The incremental contributionof the proposed action (as analyzed in Section IV.D.2.a. (6)) to the cumulative
                 impact is inconsequential because the effects of sale-specific anchoring, structure installation, pipeline
                 placement, dredging, operational discharges, service-vessel traffic, and trash and debris are estimated to be
                 sublethal. No mortalities are expected from explosive platform removal because of MMS guidelines. It is










                 IV-512

                 expected that there will be no interaction between sale-related off spills and endangered and threatened marine
                 turtles.


                 Conclusion


                     The impact of the Cumulative Case scenario on marine turtles within the potentially affected area is
                 expected to result in a decline in species numbers or a temporary displacement from their current distribution,
                 a decline or displacement that will last more than one generation.

                 (7) Impacts on Coastal and Marine Birds

                 (a) Nonendangered and Nonthreatened Species

                     The Gulf of Mexico is populated by migrant and nonmigrant species of coastal and marine birds. This
                 broad category consists of four main groups: seabirds, waterfowl, wading birds, and shorebirds.
                     This Cumulative Analysis considers the status of populations and migratory habits of coastal and marine
                 birds, and the effects of impact-producing factors related to the proposed action, plus those related to prior
                 and future OCS sales; State oil and gas activity; crude oil imports by tanker; and other commercial, military,
                 recreational offshore and coastal activities that may occur and adversely affect those populations. Specific types
                 of impact-producing factors considered in the analysis include habitat loss and degradation, oil spins, vessel
                 traffic, pipeline landfalls and coastal construction, dredging, fishing gear, plastic debris, and water
                 contamination.
                     See Section III.B.5.a. for a fully detailed discussion of coastal and marine birds in the Gulf of Mexico. The
                 four major types of coastal and marine birds have experienced decreases in population (National Geographic
                 Society, 1983a; Spendelow and Patton, 1988).
                     Nonmigrant populations of coastal birds that nest in the WPA are believed to be in decline due to habitat
                 loss from urbanization of coastal wetlands and water management practices (Section III.B.l.b.) (National
                 Geographic Society, 1983a; Texas Parks and Wildlife Dept., written comm., 1989). Overwintering migrant
                 waterfowl in the WPA are believed to be in decline due to loss and degradation of their nestirig habitat in the
                 north-central United States and south-central Canada from encroaching agriculture and drought (Ducks
                 Unlimited, 1989). Should habitat loss cease, the population will return to its pre-impact level within one to two
                 generations. However, the assumed continual loss of crucial habitat will have a deleterious impact on coastal
                 and marine birds during several or all lifestages of migratory and resident species, respectively.
                     Many coastal and marine bird populations in the Gulf of Mexico are overwintering migrants or migrants
                 passing through to wintering grounds outside the country. Waterfowl journey to Gulf feeding grounds using
                 specific flight corridors that run the length of the continental U.S. These corridors terminate in distinct
                 localities along the Gulf Coast Some waterfowl exhibit a limited degree of coastal movement within their
                 terminal locality, but do not cross planning areas (Bellrose, 1968).
                     Resident wading bird populations are augmented during the winter by migrants from as far away as
                 southern Canada. The Mississippi Delta divides migrating wading birds into distinct east-west groups in the
                 Gulf. Migrating adults of each group terminate and remain in distinct localities along the Gulf Coast, while
                 juveniles usually continue migration outside the country. Migration by Eastern Gulf juveniles begins in southern
                 Florida and terminates in the Caribbean or on the Yucatan Peninsula. Juvenile migration in the Western Gulf
                 begins and continues southwestward along the Gulf Coast, terminating in Mexico and CentralAmerica (Byrd,
                 1978; Ogden, 1978; Ryder, 1978).
                     Resident shorebird and seabird populations are augmented during the winter by migrants from as far away
                 as the North American Arctic Circle. Some species overwinter in discrete localities within a single planning
                 area of the Gulf of Mexico Region, while other species are split into distinct groups east or west of the
                 Mississippi Delta. A few species of shorebirds may continue migration. Those in the Western Gulf continue
                 along the coast into Mexico and Central America. Those in the Eastern Gulf continue to the Caribbean.
                 Those that remain on the Western or Eastern Gulf Coast exhibit a limited degree of coastal movement within










                                                                                                                                IV-513

                their terminal locality, but do not cross planning areas (Clapp, 1982a and b; Fritts et al., 1983; National
                Geographic Society, 1983b).
                     Discernible effects to regional populations or subpopulations of these migrating costal and marine birds
                as a result of OCS oil and gas activities are not expected because these species have a large areal distribution
                and do not migrate through more than one planning area.
                     Section W.C.I. estimates the mean number of offshore spills less than 1,000 bbl occurring from the
                proposed action in the WPA. Five offshore spills and one onshore spill greater than I and less than 50 bbl
                are assumed to occur each year; a few will contact the coastline. It is assumed that one offshore spill greater
                than 50 and less than 1,000 bbl will occur every 5 years and that it will not contact the coastline. It is assumed
                that one onshore spill greater than 50 and less than 1,000 bbl will occur every 10 years. For the purpose of
                this analysis, it is estimated that spills less than 1,000 bbl will seldom contact and affect coastal and marine
                birds.
                     It is assumed that 39 crude oil spills greater than or equal to 1,000 bbl win occur as a result of import
                tankering and the proposed action, plus prior and future OCS sales in the Gulf of Mexico (Table IV-22).
                Section IV.C.1. identifies the estimated risk of one or more off spills greater than or equal to 1,000 bbl resulting
                from the proposed action, prior and future OCS leasing, and import and OCS shuttle tankering occurring and
                contacting, within 10 days, the Gulf of Mexico coastline at 73 percent for imports and 85 percent for the OCS.
                In the WPA, OCS spills have a higher probability of occurrence and contact within 10 days with coastal
                Galveston, Chambers, and Cameron Counties (Table IV-22); imported oil in the WPA has the highest
                probability (23%) of an occurrence and contact within 10 days with the same counties.
                     For purposes of this analysis, it is estimated that oil spills greater than or equal to 1,000 bbl will often
                contact and affect Western Gulf inshore habitats or the coastline. Therefore, this analysis expects noticeable
                interaction between coastal and marine birds and oil spills.
                     The OCS-related helicopter traffic could disturb feeding, resting, or breeding behavior of birds, or cause
                abandonment of preferred habitat. This impact-producing factor could contribute to population losses by
                displacement of birds to areas where they may experience increased environmental or physiological stress. It
                is assumed that air traffic will adhere to the FAA Advisory Circular 91-36C prohibition of flights below a ceiling
                of 300 m over national wildlife refuges and national park lands. At this elevation, it is assumed that birds will
                not be disturbed.
                     It is assumed that, during the peak year, 12,000 OCS-related oil and gas service-vessel trips, 33 shuttle
                tanker trips, and 26 barge traffic trips will occur as a result of the proposed action, plus prior and future OCS
                sales in the WPA (Table IV-8). Noise from service-vessel traffic may elicit a startle reaction from cetaceans
                or mask their sound reception. This effect is sublethal and, at worst, of a short-term, temporary nature.
                Service vessels could collide with and directly impact coastal and marine birds, because dolphin maneuverability
                and echo-location encounters of this type are extremely rare. The OCS-related vessel traffic represents a
                meager amount of the total annual vessel traffic in the Gulf of Mexico and occurs in and out of existing port
                areas. Coastal and marine birds can avoid service vessels, and operators can avoid coastal and marine birds.
                It is estimated that service-vessel traffic will rarely contact and affect nonendangered coastal and marine birds.
                     The frequency and severity of cumulative impacts will moderately increase as a result of OCS-related
                onshore construction of 3 pipeline landfalls, 120 km of onshore pipeline, and 3 marine terminals (Table IV-13).
                An unknown but substantial amount of coastal construction is possible due to further urbanization. Coastal
                development falls under the jurisdiction of individual states.
                     Entanglement in commercial and recreational fishing gear and plastic debris causes injuries and death of
                birds. Coastal storms and hurricanes cause flooding and destruction of nesting areas, resulting in coastal and
                marine bird losses. High levels of oil and organic chemical contamination in the river runoff into the northern
                Gulf of Mexico could cause direct mortality or indirect food loss to avian species. Collision with power lines
                and supporting towers causes additional bird mortality (Avery et al., 1980).

                Summary

                     Habitat loss results in the decline of populations of coastal and marine birds. In the Western Gulf coastal
                zone, habitat loss of nonmigrating birds occurs from urbanization of coastal wetlands and water management










                  IV-514

                  practices. In the north-central United States and south-central Canada, habitat loss of migrating birds occurs
                  from encroaching agriculture and drought.
                      The OCS-related helicopter and service-vessel traffic results in displacement of birds from nesting and
                  feeding habitats. At worst, the effect of vessel or air traffic during any time of year is of a very short-term
                  nature. The FAA Advisory Circular 91-36C prohibits flight elevation below 300 m during the time of year of
                  greatest concentration of coastal and marine birds (mid-October to mid-April). Pipeline luidfalls and coastal
                  facility construction result in possible desertion of birds from feeding and breeding habitats. Entanglement or
                  ingestion of commercial fishing and recreational fishing plastic debris may injure or kill coastal and marine
                  birds. Oil spills pose the greatest threat to coastal and marine birds by direct oiling, food source contamination,
                  or breeding habitat pollution. It follows that activities have the potential to affect coastal and marine birds
                  adversely.
                      The incremental contribution of the proposed action (as analyzed in Section IV.13.2.a.(7)(a)) to the
                  cumulative impact is negligible because the effects of sale-specific helicopter and service-vessel traffic and trash
                  and debris are estimated to be sublethal. No sale-specific pipeline landfalls and coastal facility construction
                  are estimated to occur or to interact with coastal and marine birds. It is assumed that there will be no
                  interaction between sale-related oil spills and nonendangered and nonthreatened coastal and marine birds.

                  Conclusion


                      The cumulative effect on coastal and marine birds within the potentially affected area is expected to result
                  in a discernible decline in a local coastal or marine bird population or species, resulting in a change in
                  distribution or abundance. Recruitment will return the population or affected species to its pre-impact level
                  and/or condition within one to two generations. It is doubtful that this impact will affect regional populations.
                  (b) Endangered and Threatened Species

                      This Cumulative Analysis considers the effects of impact-producing factors related to the Western Gulf
                  proposed action, prior and future OCS sales, State oil and gas operations, migration, and habitat loss and
                  degradation on endangered and threatened birds, including the brown pelican, Arctic peregrine falcon, bald
                  eagle, and piping plover. Specific Pipes of impact-producing factors considered in the analysis include migratory
                  behavior, helicopter and service-vessel traffic, pipeline landfalls and coastal construction, fishing equipment,
                  plastic debris, coastal dredge-and-fill operations, and land use changes.
                      The effects from the major impact-producing factors are discussed in detail in Section IV.13.2.a.(7)(b) and
                  are described below. Sections providing supportive material for the endangered and threatened bird analysis
                  include III.B.5.(b) (description of endangered and threatened birds), IV.A-2.c. (support activities), IV.A-2.d.(5)
                  (offshore discharges), IV.B.I.c. (onshore infrastructure, activities, and impacts), IV.C.3. (oil spills), and IV.C.5.
                  (off-spill response activities).
                      Endangered birds that nest in the WPA, such as some piping plovers, bald eagles, and brown pelicans, are
                  believed to be in decline due to habitat loss from urbanization of coastal wetlands and water management
                  practices (Section III.B.1.) (National Geographic Society, 1983a; Texas Parks and Wildlife Dept., written comm.,
                  1989). Overwintering migrant, endangered birds, such as the Arctic peregrine falcon and some piping plovers,
                  are believed to be in decline due to loss and degradation of their breeding habitat in far northern latitudes of
                  the North American continent (National Geographic Society, 1983a). It is expected that habitat loss win
                  periodically affect endangered birds.
                      As previously described (Section III.B.5.b.), some piping plovers and the Arctic peregrine falcons are
                  overwintering migrants and/or migrants passing through to wintering grounds outside the country. These birds
                  use specific flight corridors that run the length of the continental U.S. These corridors terminate in distinct
                  localities along the Gulf Coast. Most piping plovers and Arctic peregrine falcons overvinter in discrete
                  localities within a single planning area of the Gulf of Mexico Region. A few of these endangered birds may
                  continue migration. Those in the Western Gulf continue along the coast into Mexico and Central America.
                  Those in the Eastern Gulf continue to the Caribbean. Those that remain on the Western or astern Gulf coast










                                                                                                                           IV-515

                exhibit a limited degree of coastal movement within their terminal locality, but do not cross planning areas
                (Clapp, 1982a and b; Fritts et al., 1983). Discernible effects to these endangered birds as a result of OCS off
                and gas activities are not expected because these species have a large areal distribution and do not migrate
                through more than one planning area.
                    It is assumed that helicopter traffic will occur on a regular basis, averaging about 135,000 trips per year.
                The FAA Advisory Circular 91-36C prohibits the use of fixed-wing aircraft lower than an elevation of 152 m
                and helicopters lower than 300 m during the period of October 15 through April 15 in the vicinity of numerous
                national wildlife refuges in the Gulf of Mexico to prevent disturbances to the birds (Biological Opinion - Section
                7 Consultation Proposed Exploration Plans for OCS in the Gulf of Mexico; FWS/OES 375.0). The majority
                of these wildlife refuges provide important critical habitats (feeding, resting, or breeding areas) for endangered
                and threatened species. Although interactions may occur and be disruptive, effects are expected to be sublethal
                and, at worst, of a temporary nature. It is expected that helicopter traffic near critical feeding, resting, or
                breeding areas will rarely disturb the brown pelican, Arctic peregrine falcon, bald eagle, or piping plover
                because of special prohibitions and adherence to the general, FAA-recommended minimum ceiling of 300 m.
                    It is assumed that, during the peak year, 12,000 OCS-related oil and vessel trips, 33 shuttle tanker trips,
                and 26 barge traffic trips will occur as a result of the proposed action plus prior and future OCS sales in the
                WPA (Table IV-8). Most of the OCS-related oil and gas traffic occurs in and out of existing port areas that
                are well away from critical feeding, resting, or breeding habitats of the Arctic peregrine falcon, bald eagle, or
                piping plover. Some OCS-related service vessel traffic occurs in the vicinity of Cameron, Intracoastal City,
                Morgan City, and Venice, Louisiana, within several miles of critical habitats for feeding, resting, or breeding
                areas of the brown pelican. Although incidents may occur and be disruptive, effects are expected to be
                sublethal and, at worst, of a temporary nature. It is expected that service-vessel traffic will rarely disturb the
                brown pelican.
                    Disturbance of brown pelican and piping plover critical feeding, resting, or breeding habitats from pipeline
                landfalls and onshore construction could result in a reduction or desertion of birds that use the habitats. It
                is assumed that three new OCS oil- and gas-related pipeline landfalls and three new coastal facilities will be
                constructed as a result of the proposed action, plus prior and future OCS sales (Table IV-13). Sublethal effects
                are expected from these activities. It is expected that pipeline landfalls and onshore construction will
                infrequently interact with critical feeding, resting, or breeding habitats of the brown pelican, Arctic peregrine
                falcon, or piping plover.
                    The brown pelican, Arctic peregrine falcon, bald eagle, and piping plover can become entangled in or
                ingest trash and debris. Interaction with plastic materials can be especially injurious. The MMS prohibits the
                disposal of equipment, containers, and other materials into offshore waters by lessees (30 CFR 250.40). In
                addition, MARPOL, Annex V, Public Law 100-220 (101 Statute 1458), which prohibits the disposal of any
                plastics at sea or in coastal waters, went into effect January 1, 1989. It is assumed that little trash and debris
                will be lost into the Gulf of Mexico as a result of the proposed action, plus prior and future OCS sales.
                However, it is expected that some trash and debris will be lost or discarded into the Gulf from non-OCS
                commercial and recreational endeavors, which are not as highly regulated. Although interactions may occur,
                effects are expected to be sublethal. It is expected that the brown pelican, Arctic peregrine falcon, bald eagle,
                and piping plover will periodically become entangled in or ingest trash and debris.
                     When an oil spill occurs, many factors interact to delimit the severity of effects and extent of damage to
                threatened and endangered birds. Determining factors include geographic location, oil type, off dosage, impact
                area, oceanographic conditions, meteorological conditions, and season (NRC, 1985; USDOI, MMS, 1987b).
                The direct effect of oiling on birds occurs through the matting of feathers and subsequent loss of body
                insulation and water-repellency, the ingestion of oil, the depression of egg-laying activity, and the reduction of
                hatching success (Holmes and Cronshaw, 1977; Ainley et al., 1981; Peakall et al., 1981). Transfer of oil from
                adults to eggs and young during nesting results in significant mortality for new eggs and deformities in
                hatchlings from eggs further along in incubation (Clapp et al., 1982a). Indirect effects of oil spills include
                contamination, displacement, and reduction of food sources. Food contamination may cause less severe,
                sublethal effects decreasing survival and fecundity, affecting behavior, and decreasing survival of young. Less
                severe, sublethal effects are defined as those that impair the ability of an organism to function effectively
                without causing direct mortality (NRC, 1985). In the event that offing of the brown pelican, Arctic peregrine










                  IV-516

                  falcon, bald eagle, or piping plover should occur from oil spills less than 1,000 bbl, the effecis would primarily
                  be sublethal; few mortalities are assumed. The effects of oil spills less than 1,000 bbl are assumed to be solely
                  sublethal due to the inconsiderable area affected. In the event that oil spills of any size should occur in critical
                  habitats for feeding, resting, or breeding, such as inshore, intertidal, and nearshore areas, sublethal effects are
                  assumed. It is assumed that the extent and severity of effects from oil spills of any size will be lessened by
                  improved coastal off-spill contingency planning and response, deterrence of birds away from the immediate area
                  of an oil spill, and increased percentage of survival from rehabilitation efforts (Section IV.C.5.).
                      Section IV.C.1. estimates the mean number of spills less than 1,000 bbl occurring as a result of the
                  proposed action plus prior and future OCS sales in the WPA_ It is assumed that five offshore spills and one
                  onshore spin greater than one and less than or equal to 50 bbl will occur each year; few will contact coastal
                  areas. It is assumed that one offshore spill greater than 50 and less than 1,000 bbl will occuir every five years
                  and that it will not contact coastal areas. It is assumed that 1 onshore spill greater than 50 and less than 1,000
                  bbl will occur every 10 years. Although an interaction with spills less than 1,000 bbl is assumed, only sublethal
                  effects are assumed. It is assumed that spills less than 1,000 bbl will periodically contact and affect the brown
                  pelican, Arctic peregrine falcon, bald eagle, and piping plover.
                      It is assumed that 39 crude oil spills greater than or equal to 1,000 bbl will occur as IL result of import
                  tankering and the proposed action, plus prior and future OCS sales in the Gulf of Mexico (Table IV-22).
                  Section IV.C.I. identifies the estimated risk of one or more oil spills greater than or 1,000 bbI occurring and
                  contacting critical habitats within 10 days for feeding, resting, or breeding of the brown pelican, Arctic peregrine
                  falcon, bald eagle, and piping plover in the WPA. The highest probability of one or more oilspills greater than
                  or equal to 1,000 bbl occurring and contacting a coastal bay in the Western Gulf within 10 (lays is 22 percent
                  (Galveston -Bay).- The highest estimated probability of one or more spills greater than or equal'to 1,000 bbl
                  occurring and contacting within 10 days Texas coastal marshes is 27 percent. Although an interaction with spins
                  greater than or equal to 1,000 bbl is expected, primarily sublethal effects are assumed with infrequent
                  mortalities. It is assumed that an oil spill greater than or equal to 1,000 bbl will periodically contact and affect
                  the brown pelican, Arctic peregrine falcon, bald eagle, and piping plover in the WPA.
                      Some critical feeding habitats of the brown pelican, Arctic peregrine falcon, and piping plover occur
                  nearshore. The highest estimated probability of one or more spills greater than or equal to 1,000 bbl occurring
                  and contacting within 10 days nearshore areas (coastline) along the Western Gulf is 85 percent. Although an
                  incident is expected, sublethal effects are assumed. It is assumed that an oil spill greater than or equal to 1,000
                  bbl will periodically contact and affect nearshore areas (coastline) critical to the feeding of the brown pelican,
                  Arctic peregrine falcon, and piping plover.

                  Summary

                      The brown pelican, Arctic peregrine falcon, bald eagle, and piping plover may be impacted by helicopter
                  and service-vessel traffic, onshore pipeline landfalls, entanglement in and ingestion of offshore oil- and gas-
                  related plastic debris, and oil spills. The effects of these activities are estimated to be sublethal. Lethal effects
                  are assumed only from oil spills greater than or equal to 1,000 bbl. Oil spills of any size are estimated to be
                  infrequent events that will periodically contact threatened and endangered birds or their critical feeding, resting,
                  or breeding habitats.
                      The incremental contribution of the proposed action (as analyzed in Section IV.D.2.a.(7)(b)) to the
                  cumulative impact is inconsequential because the effects of sale-specific helicopter and sen,ice-vessel traffic,
                  trash and debris, and onshore pipeline landfalls are estimated to be sublethal. It is assumed that there will be
                  no interaction between sale-related oil spills and endangered and threatened coastal and marine birds.

                  Conclusion

                      The impact of the Cumulative Case scenario on endangered and threatened birds within the potentially
                  affected area is assumed to result in a decline in species numbers or a temporary displacement from their
                  current distribution, a decline or displacement that will last more than one    generation.










                                                                                                                            IV-517

               (8) Impacts on Commercial Fisheries

                   This Cumulative Analysis considers the status of commercial fishery stocks, the effects of impact-producing
               factors related to the Western Gulf proposed action, prior and future OCS sales, State oil and gas activity,
               crude oil imports by tanker, and offshore recreational fishing that may occur and adversely affect the
               commercial fishing industry in the same general area that may be affected by OCS oil and gas activity located
               in the WPA. Specific types of impact-producing factors considered in the analysis include commercial fishing
               techniques or practices, loss of wetlands, structure removal, and construction of offshore oil and gas platforms.
                   Sections providing supportive material for the commercial fisheries analysis include Sections III.B.6.
               (description of fish resources), III.C.3. (commercial fishing stocks and activities), IV.A.2.d.(3) (use conflicts),
               IV.A.2.b.(l) (pipelines), IV.A-2.a.(3) (structure removal), IV.A.2.a.(l) (seismic operations), IV.C.3. (oil spills),
               IV.A.2.d.(8) (subsurface blowouts), IV.B.Lb.(4)(e) (offshore discharges), and IV.B.l.c. (onshore discharges).
               Competition between large numbers of commercial fishermen, between commercial operations employing
               different fishing methods, and between commercial and recreational fishermen for a given fishery resource, as
               well as natural phenomena such as weather, hypoxia, and red tides, may reduce standing populations. Fishing
               techniques such as trawling, gill netting, or purse seining, when practiced nonselectively, may reduce the
               standing stocks of the desired target species as well as significantly impact species other than the target.
               Space-use conflicts can result from different forms of commercial operations and between commercial and
               recreational fisheries. Finally, hurricanes may impact commercial fisheries by destroying oyster reefs, damaging
               gear and shore facilities, and changing physical characteristics of inshore and offshore ecosystems. The
               availability and price of fuel can also affect commercial fishing operations in the Gulf of Mexico.
                   The majority of commercial species harvested from the Gulf of Mexico are believed to be in serious decline
               from overfishing. Continued fishing at the present levels may result in rapid declines in commercial landings
               and eventual failure of certain fisheries. Commercial landings of traditional fisheries, such as shrimp and red
               snapper, have declined over the past decade despite increases in fishing effort. Commercial landings of recent
               fisheries, such as shark, black drum, and tuna, have increased exponentially over the past five years, and those
               fisheries are thought to be in danger of collapse (Angelovic, written comm., 1989; USDOC, NMFS, 1989a).
               It is expected that overfishing will adversely affect commercial fishery resources. The severity of the effects
               of overfishing on the commercial fishing resources could be prominent, involving a decline in populations of
               commercial importance that will recover to pre-impact level within two to three generations.
                   Because approximately 92 percent of commercially important species are estuarine dependent, the
               degradation of inshore water quality and the loss of Gulf wetlands as nursery areas are considered significant
               threats to the commercial fishing industry (Angelovic, written comm., 1989; Christmas et al., 1988; USEPA,
               1989). Loss of wetland nursery areas in the WPA is believed to be the result of urbanization of coastal
               wetlands and water management practices (Texas Parks and Wildlife Dept., written comm., 1989). It is
               expected that wetlands loss and water quality degradation will adversely affect commercial fishery resources.
               The severity of the effects of wetlands loss and water quality degradation on commercial fishing resources could
               be considerable, involving a decline in populations of commercial importance that will recover to pre-impact
               level within two to three generations.
                   Those species of commercial importance that are not estuarine dependent, such as mackerel, cobia, and
               crevalle, are considered coastal pelagics. Populations of these species exhibit some degree of coastal
               movement These species range throughout the Gulf, move seasonally, and are more abundant in the WPA
               during the summer (Gulf of Mexico Fishery Management Council, 1985). In general, the coastal movements
               of these species are restricted to one or two planning areas within the Gulf of Mexico Region and are not truly
               migratory, as is the case with salmon. The coastal movements of these species are related to reproductive
               activity, seasonal changes in water temperature, or other oceanographic conditions. Discernible effects to
               regional populations or subpopulations; of these species as a result of OCS oil and gas activities are not
               expected, because pelagic species are distributed and spawn over a large geographic area and depth range.
                   Structure removals result in artificial habitat loss and cause fish kills when explosives are used. Table IV-8
               assumes that 231 structure removals by explosives will occur in the WPA under the cumulative scenario during
               the 35-year life of the proposed action. It is assumed that no more than 12 removals will occur in the WPA










                  IV-518

                  during this time in any single year. For the purpose of this analysis, it is estimated that structure removals may
                  have a minor effect on Western Gulf fisheries because removals will be unusual events killing only those fish
                  proximate to the removal site.
                      The 140 additional platform complexes resulting from the proposed action, plus prior and future OCS sales
                  in the WPA (Table IV-8), are estimated to reduce trawling area by about 1,602 ha (3,957 ac) during the peak
                  year. This represents an inconsequential amount of the total trawling area in the WPA. It is expected that
                  platform emplacement will rarely affect trawling activity.
                      Off spills that contact coastal bays, estuaries, and waters of the OCS during the time when high
                  concentrations of pelagic eggs and larvae are present have the greatest potential to damage commercial fishery
                  resources.
                      Section IV.C.I. estimates the mean number of offshore spills less than 1,000 bbl occurring from the
                  proposed action, plus prior and future OCS sales in the Gulf of Mexico. Although spills greater than 1 and
                  less than 50 bbl may occur each year, none is assumed to occur in proximity to coastal environments. It is
                  assumed that oil spills, plus prior and future OCS sales in the Gulf of Mexico, will not affect coastal bays and
                  marshes essential to the well-being of the commercial fishery resources in the WPA-
                      Section IV.C.I. estimates the mean number of spills greater than or equal to 1,000 bbl occurring from
                  cumulative activity in the WPA. It is assumed that 2 crude oil spills greater than or equal to 1,000 bbI from
                  OCS platforms and pipelines and 37 spills from import tankering will occur in the Gulf of Mexico over the
                  35-year life of the proposed action. Section IV.C.3. identifies the estimated risk of one or more oil spins
                  greater than or equal to 1,000 bbl, resulting from cumulative activity (the proposed action, prior and future
                  OCS leasing, import tankering, and OCS shuttle tankering), occurring and contacting, within 10 days, coastal
                  bays and marshes essential to the well-being of commercial fishery resources in the WPA-
                      The estimated mean number of spills greater than or equal to 1,000 bbl to occur and contact within 10 days
                  nearshore areas (coastline) in the Cumulative Case in the Gulf is two. The estimated mean number of spins
                  greater than or equal to 1,000 bbl to occur and contact within 10 days Texas coastal marshes is less than 1
                  (Table IV-22). Galveston County, Texas, is the land segment with the highest probability (22% from imports)
                  of occurrence and contact by one or more spills greater than or equal to 1,000 bbl. Galveston Bay is the
                  coastal inshore bay with the highest probability (22% from imports) of being contacted by one or more spins
                  greater than or equal to 1,000 bbl. The highest estimated probability of one or more spills greater than or
                  equal to 1,000 bbl occurring and contacting within 10 days the Texas coastal marshes is 27 percent for east
                  Texas coastal marshes from import tankers.
                      Off spills greater than or equal to 1,000 bbl originating in port from the tankering of imported oil include
                  those that may occur and contact bays and estuaries. The highest estimated probability of one or more oil
                  spills greater than or equal to 1,000 bbl originating from tankering of imported oil occurring and contacting
                  within 10 days a Western Gulf bay or estuary is 98 percent (Houston). The estimated number of spills greater
                  than or equal to 1,000 bbl from tankering of imported oil occurring and contacting within 1.0 days a Western
                  Gulf bay or estuary in the next 35 years is eight. There are no offshore ports in the Western Gulf The closest
                  offshore port is the Louisiana Offshore Oil Port (LOOP). The highest estimated probability of one or more
                  oil spills from tankering of imported oil occurring and contacting within 10 days OCS waters from LOOP is
                  97 percent. The estimated number of spills greater than or equal to 1,000 bbl from tankering of imported oil
                  occurring and contacting within 10 days OCS waters from LOOP is eight (Section MCA).
                      It is assumed that the interaction of oil spills greater than or equal to 1,000 bbl, either assumed to occur
                  and contact or assumed to occur, as a result of cumulative activity, with commercial fishery resources in the
                  Western Gulf will have a considerable effect on the commercial fishing industry. It is estimated that oil spills
                  will regularly contact and affect Western Gulf coastal bays, estuaries, or coastal areas. As a singular example,
                  the highest estimated probability of one or more oil spills greater than or equal to 1,000 bbl occurring and
                  contacting within 10 days Gulf menhaden during their winter spawning in coastal waters of the WPA is 31
                  percent from platforms, pipelines, or shuttle tankers. Therefore, this analysis expects noticeable interaction
                  between commercial fishery resources and oil spills greater than or equal to 1,000 bbl.











                                                                                                                          IV-519


                 Summary

                     Several impact-producing factors may threaten the commercial fishing industry.
                     Habitat loss results in the decline of commercial populations, essential habitats, and commercial fishing
                 activity. In the Western Gulf coastal zone, habitat loss of nonmigrating birds occurs from urbanization of
                 coastal wetlands and water management practices.
                     Overfishing results in rapid declines in commercial populations and landings and in the eventual failure
                 and loss of both traditional and recent fisheries. The majority of commercial species harvested from the Gulf
                 of Mexico are believed at present to be in a seriously depleted condition due to overfishing.
                     Structure removals result in habitat loss and cause fish kills in the vicinity of the removal.
                     Off spills pose the greatest threat to the commercial fishing industry by direct contact with eggs, larvae,
                 juveniles, or massed spawning adult finfish or shellfish; by contamination of essential estuarine nursery habitat
                 or by deterrence of commercial fishing activity.
                     It follows that activities have the potential to affect the commercial fishing industry detrimentally.
                     The incremental contributionof the proposed action (as analyzed in Section IV.D.l.a.(9)) to the cumulative
                 impact is inconsequentialbecause the effects of sale-specific underwater OCS obstructions, subsurface blowouts,
                 operational discharges, explosive structure removal, space-use conflict, and seismic surveys are expected to be
                 negligible. It is estimated that there will be no interaction between sale-related oil spills and areas essential
                 to commercial fisheries.


                 Conclusion

                     The cumulative effect of the above-listed, impact-producing factors on the commercial fishing industry
                 within the potentially affected area is expected to result in a discernible decline in populations of commercial
                 importance, in the quality of essential habitats, or in commercial fishing activity. Recruitment will return any
                 affected population, habitat, or activity to pre-impact level and/or condition within two to three generations.

                 (9) Impacts on Recreational Resources and Activities

                 (a) Beach Use

                     This Cumulative Analysis considers the effects of impact-producing factors related to the proposed action
                 (Section IVD.2.a.(9)(a)), plus those related to prior and future OCS sales, State offshore oil and gas activity,
                 tankering of crude oil imports, merchant shipping, commercial and recreational fishing, defense operations,
                 recreational use of beaches, and other offshore and coastal activity that results in debris, litter, trash, and
                 pollution, which may occur and adversely effect major recreational beaches. Specific impact-producing factors
                 analyzed include oil spills and trash and debris. Other factors such as commercial, industrial, and residential
                 land developments, civil works projects, and natural phenomena have affected, and will continue to affect,
                 beach-associated characteristics, such as barrier island stabilization (Section IVD.2.a.(l)(a) and air quality
                 (Section IV.D.2.a.(4); ultimately, these factors may also affect the recreational use of beaches.
                     A mean number of two oil spills greater than or equal to 1,000 bbl (Table IV-19), and a few spins each
                 year greater than I and less than or equal to 50 bbl are assumed to occur and contact land as a result of
                 Federal OCS activity and crude-oil import tankering (Section IV.C.4.). Estimates of one or more spills greater
                 than or equal to 1,000 bbl occurring and contacting within 10 days major recreational beaches in Texas
                 (Galveston/Bolivar Peninsula) and Louisiana (Cameron beaches) are presented in Table IV-22. Spills of 1,000
                 bbl (Section IV.C.1.) are assumed to result in short-term disturbances, causing temporary loss or displacement
                 of water-related, nearshore recreational activity on specific beaches directly or indirectly impacted.
                 Furthermore, over the next 35 years 16 spills greater than or equal to 1,000 bbl (Section IV.C.l.) involving
                 tankers carrying imported petroleum liquids could adversely impact beaches in the vicinity of major inshore
                 Gulf of Mexico ports from Mobile to Corpus Christi. It is important to realize, especially in the cumulative
                 impact context, that of all chronic hydrocarbon pollution existing in the Gulf, less than 1 percent is directly










                  IV-520

                  related to Gulf of Mexico oil and gas leasing and production (Section IV.C.4.). In terms of effects, chronic
                  natural and human-induced hydrocarbon pollution can manifest itself on beaches as tarballs, which would
                  adversely impact beach users, recreational developments, and personal property.
                      Continued and expanded off and gas operations in the VVTA have contributed to the already serious
                  problem of debris and trash on coastal beaches. Trash and debris detract from the aesthetic quality of beaches,
                  can be hazardous to beach recreational activity, and can increase the cost of beach maintenance programs.
                  Other factors, such as merchant shipping, naval operations, offshore commercial and recreational fishing,
                  natural phenomena, recreational use of beaches, State off and gas activity, tankering, pipelines, operational
                  discharges, condominiums, coastal activity in Mexico and Cuba, and other offshore and coastal activities,
                  contribute to flotsam, jetsam, pollution, and litter existing on Gulf of Mexico recreational beaches. Trash and
                  debris are a recognized problem affecting enjoyment and maintenance of recreational beaches in the WPA.
                  It has been estimated that OCS oil and gas operations are contributing 10-12 percent of the trash and debris
                  affecting Texas and Louisiana recreational beaches (USEPA, 1990; Parker, personal comm., 1990).
                      A recent report resulting from a detailed marine debris monitoring program at coastal national parks (Cole
                  et al., 1990) indicates plastics compose a preponderance of litter and debris items at Padre Island National
                  Seashore, and plastic pellets used in plastics manufacturing composed the most numerous item within the
                  plastics category (73%). Although microplastics have little effect on recreational beach use, large plastic items,
                  drums, and broken glass, which are also recorded, can adversely impact beach use. Items known to be
                  associated with the oil and gas industry have been frequently identified with the beach litter removed from
                  Texas and Louisiana beaches; however, some of these items, such as computer write-protection rings, have
                  noticeably declined in the past few years. Regulatory, administrative, and volunteer programs involving
                  government, industry, and private citizens, and environmental, school, and civic groups are monitoring and
                  reducing the gravity of the beach litter problem GullWide.

                  Summary

                      For purposes of this analysis, one or two oil spills greater than or equal to 1,000 bbl that are assumed to
                  preclude short-term recreational use of some Texas beaches at the park or community levels for the next 35
                  years. However, smaller annual spills throughout the planning area are assumed to preclude short-term use
                  of the small segments of recreational beaches adversely impacted, but will have little effect on local recreational
                  use or tourism. Frequent impacts from man-induced debris and litter derived from both offishore and onshore
                  sources are assumed to diminish the tourist potential of beaches in the WPA and to degrade chronically the
                  ambience of shorefront recreational beaches, thereby affecting the enjoyment of recreational beaches
                  throughout the planning area. However, pollution and debris associated with the proposed sale will contribute
                  minimally to this impact.
                      A ton or more per mile of trash and debris has been removed from some Texas recreational beaches
                  cleaned each fall since 1986. Sale-specific operational activities are not assumed to cause beach or park
                  closures or to generate the need for excessive beach maintenance. Accidental loss of solid waste from offshore
                  activities generated by this sale is assumed to impact Texas beaches; however, this incremental litter is unlikely
                  to be perceptible by beach users or administrators because it will constitute only a very small percentage of
                  the existing trash and litter found on Texas beaches. Improved offshore waste management practices,
                  implementation of recently imposed MARPOL regulations, and participation and support by most marine user
                  groups and public agencies in implementing the Gulf of Mexico Program's Marine Debris Action Plan should
                  gradually improve the recreation quality of Texas beaches.

                  Conclusion


                      Although trash and accidental oil spills will continue to affect the ambience of Texas recreational beaches
                  adversely, the level of chronic pollution should decline during the life of the proposed action. Beach use at
                  the regional level is unlikely to change from existing patterns; however, closure of specific beaches or parks
                  directly impacted by one or two oil spills greater than or equal to 1,000 bbl is assumed during cleanup
                  operations.










                                                                                                                              IV-521

                 (b) Marine Fishing

                      This Cumulative Analysis considers the effects of impact-producing factors related to the proposed action
                 (Section IV.13.2.a.(9)(b), plus those related to prior and future OCS sales; State offshore oil and gas activity;
                 tankering of crude oil imports; other marine vessel traffic and port congestion; and other commercial, military,
                 and recreational offshore activities that might affect offshore marine recreational fishing.
                      Activity related to OCS oil and gas development is projected to add 140 offshore platform complexes in
                 the WPA over the next 35 years (Table IV-8). Of these, 15 new platforms are projected for the W-1 coastal
                 subarea. Platforms here will be those closest to shore and assumed to affect offshore fishing because they
                 function as accessible, high profile, de facto artificial reefs. These structures would add to the existing 380 OCS
                 petroleum structures currently in the WPA and several permitted artificial reefs also in the planning area.
                 Studies and observations have shown that, where oil and gas structures are accessible, they are significant
                 attractants of offshore fishermen and they enhance fishing success. Conversely, anthropogenic pollution and
                 activity (oil and chemical spills, competition between commercial and recreational fishermen and among
                 recreational fishermen, coastal modifications brought on by industrial development and population increases
                 in the coastal zone) and inevitable natural forces, such as subsidence, erosion, anoxia, floods, and freezes, will
                 affect long-term sociological and ecological changes. These pollution events, fishing activities, and changes win
                 directly and indirectly stress fishery resources important to marine recreational fishing and could lead to the
                 increase of restrictive regulations affecting fishing enjoyment and participation. Should there be a sustained,
                 declining trend in offshore fishing trips, the recreational fishing support industry is likely to suffer as wen.
                      The two offshore off spills greater than or equal to 1,000 bbl (Table IV-19) from either platforms, pipelines,
                 or tankers and eight inshore tanker spills from Houston to Corpus Christi assumed to occur over the next 35
                 years will cause temporary disinterest in recreational fishing within the area of visible oil slicks, but should not
                 affect the level of recreational fishing within the planning area.
                      Offshore oil and gas activity (platforms) has had a major impact on recreational fishing in the WPA in that
                 it has helped to focus the location of offshore fishing and enhanced fishing success. A continuation of oil and
                 gas development as a result of continued Federal and State offshore lease sales is expected to help maintain
                 recreational fishing levels in offshore areas of the WPA over the next 35 years. Because of the expected
                 increase in the structure removal rate in the Federal waters of the Gulf of Mexico (currently around 100 per
                 year off Louisiana and Texas), and greater interest in artificial reef development Guffwide, more interest in
                 the use of obsolete oil and gas structures as dedicated reefs in the marine environment is likely. The National
                 Fishing Enhancement Act of 1984 and management measures adopted by NMFS through the planning efforts
                 of the Gulf of Mexico Fishery Management Council will also affect the future of offshore fishing in the WPA.

                 Summary

                      Both anthropogenic and natural events (fishing, degradation and loss of wetlands, environmental change
                 brought on by extreme weather conditions, and the degradation of coastal and offshore water quality from all
                 types of pollution) will adversely affect marine recreational fishing.
                      The incremental contribution of the proposed action (as analyzed in Section IV.13.2.a.(9)(b)) to the
                 cumulative impact is minimal because sale-specific activity will generate only a few offshore platforms readily
                        'ble to marine recreational fishermen.
                 accessi


                 Conclusion


                      Continued offshore oil and gas development over the next 35 years will continue to support, maintain, and
                 facilitate offshore recreational fishing in the WPA and extend the time offshore oil and gas structures are a
                 focus of offshore fishing activity.










                 IV-522

                 (10) Impacts on Archaeological Resources

                 (a) Histotic

                     Thefollowing analysis considers not only the effects of the impact-producing factors related to the
                 proposed action, but OCS activities in the Central Gulf, as well as prior and future OCS sales. Specific types
                 of impact-producing factors considered in this analysis include drilling rig and platform emplacement, pipeline
                 emplacement, anchoring, oil spills, dredging, new onshore facilities, and ferromagnetic debris associated with
                 OCS hydrocarbon activities. Included also in this analysis are trawling, sport diving, commercial treasure
                 hunting, and tropical storms. A discussion of each impact-producing factor is presented in Section
                 IV.D.l.d.(11).
                     Future OCS exploration and development activities in the WPA are expected to result in the drilling of
                 5,280 exploration and delineation wells and 2,050 development wells, the installation of 140 platforms, and the
                 laying of 3,510 km of offshore pipelines (Table IV-8). The archaeological surveys are expected to reduce the
                 potential for an interaction between an impact-producing activity and an historic resource by 95 percent in
                 those WPA areas that have a thin Holocene sediment veneer (eastern part of the WPA). Archaeological
                 surveys are estimated to be 90 percent effective in those WPA areas that have a 'thick blanket of
                 unconsolidated Holocene sediments (western portion of WPA). Archaeological surveys were first required in
                 1974; therefore, it is assumed that the major impacts to historic resources resulted from development prior to
                 1974. The potential of an interaction between rig or platform emplacement and an historic shipwreck is
                 diminished by the survey, but still exists. Such an interaction could result in the loss of significant or unique
                 historic information.
                     The placement of 3,510 km of pipelines in the WPA is projected. According to Table IV-8, there are
                 currently 4,654 kin of pipelines on the Western Planning Area OCS. While the archaeological survey minimizes
                 the chances of impacting an historic shipwreck, there remains a possibility that a wreck could be impacted by
                 pipeline emplacement. Should such an impact occur, significant or unique historic archaeological information
                 could be lost.
                     The setting of anchors for drilling rigs, platforms, and pipeline lay barges, and anchoring associated with
                 oil and gas vessel trips to the OCS have the potential to impact historic wrecks. The archaeological surveys
                 serve to minimize the chance of impacting historic wrecks; however, these surveys are not ;seen as infallible,
                 and the chance of an impact from future activities exists. A total of about 212,000 shuttle tanker, barge, and
                 service vessel trips are projected for the WPA (Table IV-13). Impacts from anchoring on an historic shipwreck
                 may have occurred. There is also a potential for future impacts from anchoring on an historic shipwreck. Such
                 an interaction could result in the loss of significant or unique information.
                     Oil spills have the potential to impact coastal historic sites directly or indirectly by physical impacts caused
                 by oil spill cleanup operations. According to Table IV-22, there is an estimated 85 percent probability of one
                 or more oil spills greater than or equal to 1,000 bbl occurring and contacting the WPA coastal area within 10
                 days. There is up to a 73 percent probability that an imported oil spill greater than or equall. to 1,000 bbl will
                 occur and contact the WPA coastal area within 10 days. However, the impacts caused by oil spills to coastal
                 historic archaeological resources are generally short term and reversible.
                     Most channel dredging occurs at the entrances to bays, harbors, and ports. These areas have a high
                 probability for historic shipwrecks, and the greatest concentrations of historic wrecks are likely associated with
                 these features (Garrison et al., 1989). It is assumed that significant or unique archaeological information has
                 been lost as a result of past channel dredging activities. In many areas, COE requires remote-sensing surveys
                 prior to dredging activities to minimize such impacts (Espey, Huston, & Associates, 1990).
                     Past, present, and future OCS oil and gas exploration and development will result in the deposition of
                 several tens of thousands of tons of ferromagnetic debris on the seafloor. This modern marine debris will tend
                 to mask the magnetic signatures of historic shipwrecks, particularly in areas that were developed prior to
                 requiring archaeological surveys in the WPA (offshore Subareas W-1 and W-2). Such masking of the signatures
                 characteristic of historic shipwrecks may have resulted in OCS activities impacting a shipwreck containing











                                                                                                                             IV-523

                 significant or unique historic information. Potential impacts caused by the masking of magnetic signatures
                 could result in the damage to or loss of significant or unique historic archaeological information.
                      Trawling activity in the WPA would only affect the uppermost portion of the sediment column (Garrison
                 et al., 1989). On many wrecks, this zone would already be disturbed by natural factors and would contain only
                 artifacts of low specific gravity that have lost all original contact According to Table IV-13, 3 terminals (each
                 requiring 7-24 ha of land), 3 pipeline landfalls, and 120 km of onshore pipelines will be necessary to support
                 total Western Planning Area OCS program activities. Investigations prior to construction can determine if
                 historic archaeological resources exist at the sites.
                      Because MMS does not have jurisdiction over pipelines in State waters, the archaeological resource
                 protection requirements of the National Historic Preservation Act (NHPA) are not within MMS's jurisdiction.
                 However, other Federal agencies, such as the COE, which lets permits associated with pipelines in State waters,
                             ible for the protection of archaeological resources under the NHPA_ Therefore, the impacts that
                 are responsi
                 might occur to archaeological resources by pipeline construction within State waters should be mitigated under
                 the requirements of the NHPA.
                      Sport diving and commercial treasure hunting are significant factors in the loss of historic data from wreck
                 sites. While commercial treasure hunters generally impact wrecks with intrinsic monetary value, sport divers
                 may collect souvenirs from all types of wrecks. Since the extent of these activities is unknown, the impact
                 cannot be quantified. It is assumed that some of the data lost have been significant or unique.
                      About one-third of the coast in the Western Gulf was hit with 16-20 tropical cyclones between the years
                 1901 and 1955 (DeWald, 1982). The other two-thirds had a slightly lower incidence of cyclones (11-15).
                 Shipwrecks in shallow waters are exposed to a greatly intensified longshore current during tropical storms
                 (Clausen and Arnold, 1975). Under such conditions, it is highly likely that artifacts of low specific gravities
                 (e.g., ceramics and glass) would be dispersed. Some of the original information contained in the site would
                 be lost in this process, but a significant amount of information would also remain. Overall, a significant loss
                 of data from historic sites has probably occurred, and will continue to occur, in the Western Gulf from the
                 effects of tropical storms. Some of the data lost have most likely been significant or unique.

                 Summary

                      Several impact-producing factors may threaten historic archaeological resources of the Western Gulf, An
                 impact could result from a contact between an OCS activity (pipeline and platform installations, drilling rig
                 emplacement and operation, dredging, and anchoring activities) and an historic shipwreck located on the
                 continental shelf. The archaeological surveys and resulting archaeological analysis and clearance that are
                 required prior to an operator beginning oil and gas activities in a lease block are estimated to be 90 percent
                 effective at identifying possible historic shipwrecks in areas of the WPA with a high probability for the presence
                 of historic period shipwrecks and a thick blanket of unconsolidated sediments (western part of the WPA).
                 Development of the WPA prior to requiring archaeological surveys has possibly impacted wrecks containing
                 significant or unique historic information.
                      The loss of tons of ferromagnetic debris associated with oil and gas exploration and development could
                 result in the masking of historic shipwrecks. It is expected that dredging, sport diving, commercial treasure
                 hunting, and tropical storms have impacted and will continue to impact historic period shipwrecks. Such impact
                 will likely result in the loss of significant or unique archaeological information.
                      Onshore development as a result of the proposed action could result in the direct physical contact between
                 an historic site and new facility construction and pipeline trenching. It is assumed that archaeological
                 investigations prior to construction will serve to mitigate these potential impacts. While the likelihood of an
                 oil spill occurring and contacting within 10 days the WPA coastline is high, assumed effects on historic coastal
                 resources are temporary and reversible. Loss of significant or unique historic archaeological information from
                 commercial fisheries (trawling) is not expected.
                      The effects of the various impact-producing factors discussed in this analysis have likely resulted in the loss
                 of significant or unique historic archaeological information. In the case of factors related to OCS Program
                 activities, it is reasonable to assume that most impacts would have occurred prior to 1974 (the date of initial
                 archaeological survey and clearance requirements). The incremental contribution of the proposed action is










                  IV-524

                  expected to be very small due to the efficacy of the required remote-sensing survey and archaeological report
                  However, there is a possibility of an interaction between bottom-disturbing activity (rig empticement, pipeline
                  trenching, and anchoring) and an historic shipwreck.

                  Conclusion


                      The total of OCS program and non-program-related impact-producing factors have likely resulted and may
                  yet result in the loss of significant or unique historic archaeological information.

                  (b) ftehistotic

                      Future OCS exploration and development activities in the WPA are expected to result in the drilling of
                  5,280 exploration and delineation wells and 2,050 development wells, the installation of 140 platforms, and the
                  laying of 3,510 Ian of offshore pipelines (Table IV-8). The archaeological surveys are expected. to reduce the
                  potential for an interaction between an impact-producing activity and a prehistoric resource by 90 percent.
                  Because archaeological surveys were first required in 1974, it is assumed that the major impacts to historic
                  resources resulted from development prior to 1974. The potential of an interaction between rig or platform
                  emplacement and a prehistoric site is diminished by the survey, but still exists. Such an interaction could result
                  in the loss of significant or unique prehistoric information.
                      The placement of 3,510 km of pipelines in the WPA is projected. According to Table IV-8, there are
                  currently 4,654 kin of pipelines on the Western Planning Area OCS. While the archaeological survey minimizes
                  the chances of impacting a prehistoric site, there remains a possibility that a site could be impacted by pipeline
                  emplacement Should such an impact occur, significant or unique prehistoric archaeological information could
                  be lost.
                      The setting of anchors for drilling rigs, platforms, and pipeline lay barges, and anchoring associated with
                  oil and gas vessel trips to the OCS have the potential to impact shallow, emplaced prehistoric sites. The
                  archaeological surveys serve to minimize the chance of impacting these sites; however, these surveys are not
                  seen as infallible, and the chance of an impact from future activities exists. A total of about 212,000 shuttle
                  tanker, barge, and service vessel trips are projected for the VvTA (Table IV-13). Impacts from anchoring on
                  a prehistoric site may have occurred. There is also a potential for future impacts from anchoring on a
                  prehistoric site. Such an interaction could result in the loss of significant or unique information.
                      Oil spills have the potential to impact coastal prehistoric sites directly, or indirectly by physical impacts
                  caused by off spill cleanup operations. According to Table IV-22, there is an estimated 85 percent probability
                  of an oil spill greater than or equal to 1,000 bbl occurring and contacting the WPA coastal area within 10 days.
                  There is an estimated 73 percent probability that an oil spill greater than or equal to 1,000'bbl win occur and
                  contact the WPA coastal area within 10 days. 'Me impacts caused by off spills to cDastal prehistoric
                  archaeological resources can severely distort information relating to the age of the site. Contamination of the
                  site organics by modem hydrocarbons can render dating by C-14 methods useless. This loss might be
                  ameliorated by artifact seriation or other relative dating techniques. Coastal prehistoric sites might also suffer
                  direct impact from beach cleanup operations. Interaction between oil-spill cleanup equipment and a site could
                  destroy fragile artifacts or disturb site context, possibly resulting in the loss of information on the prehistory
                  of North America and the Gulf Coast Region. Some coastal sites may contain significant or unique
                  information.
                      Most channel dredging occurs at the entrances to bays, harbors, and ports. Bay and river margins have
                  a high probability for prehistoric sites. It is assumed that significant or unique archaeologicil information has
                  been lost as a result of past channel dredging activities. In many areas, COE requires survey-s prior to dredging
                  activities to minimize such impacts.
                      Trawling activity in the WPA would only affect the uppermost portion of the sediment column (Garrison
                  et al., 1989). This zone would already be disturbed by natural factors and site context to this depth would
                  presumably be disturbed.










                                                                                                                             IV-525

                    Investigations prior to construction can determine if prehistoric archaeological resources exist at the sites.
                According to Table IV-13, 3 terminals (each requiring 7-24 ha of land), 3 pipeline landfalls, and 120 kin of
                onshore pipelines will be necessary to support total Western Planning Area OCS program activities.
                    Because MMS does not have jurisdiction over pipelines in State waters, the archaeological resource
                protection requirements of the NHPA are not within MMS's jurisdiction. However, other Federal agencies,
                such as the COE, which lets permits associated with pipelines in State waters, are responsible for the protection
                of archaeological resources under the NHPA. Therefore, the impacts that might occur to archaeological
                resources by pipeline construction within State waters should be mitigated under the requirements of the
                NHPA.
                    About one-third of the coast in the Western Gulf was hit with 16-20 tropical cyclones between the years
                1901-1955 (DeWald, 1982). The other two-thirds had a slightly lower incidence of cyclones (11-15). Prehistoric
                sites in shallow waters or on coastal beaches are exposed to the destructive effects of wave action and scouring
                currents. Under such conditions, it is highly likely that artifacts would be dispersed and the site context
                disturbed. Some of the original information contained in the site would be lost in this process. Overall, a
                significant loss of data from prehistoric sites has probably occurred, and will continue to occur, in the Western
                Gulf from the effects of tropical storms. Some of the data lost have most likely been significant or unique.

                Summary

                    Several impact-producing factors may threaten prehistoric archaeological resources of the Western Gulf.
                An impact could result from a contact between an OCS activity (pipeline and platform installations, drilling
                rig emplacement and operation, dredging, and anchoring activities) and a prehistoric archaeological site located
                on the continental shelf. The archaeological surveys and resulting archaeological analysis and clearance that
                are required prior to an operator beginning oil and gas activities in a lease block are estimated to be 90 percent
                effective at identifying possible prehistoric sites in the WPA_ Development of the WPA prior to requiring
                archaeological surveys has possibly impacted sites containing significant or unique prehistoric information.
                    Expected effects from dredging and tropical storms are estimated to result in damage to or loss of
                significant or unique archaeological information. The likelihood of an oil spill occurring and contacting within
                10 days the WPA coastline is high. Such contact could result in loss of significant or unique information
                relating to the dating of a prehistoric site. Onshore development as a result of the proposed action could result
                in the direct physical contact between a prehistoric site and new facility construction and pipeline trenching.
                It is assumed that archaeological investigations prior to construction will serve to mitigate these potential
                impacts. Loss of significant or unique historic archaeological information from commercial fisheries (trawling)
                is not expected.
                    The effects of the various impact-producing factors discussed in this analysis have likely resulted in the loss
                of significant or unique prehistoric archaeological information. In the case of factors related to OCS Program
                activities, it is reasonable to assume that most impacts would have occurred prior to 1974 (the date of initial
                archaeological survey and clearance requirements). The incremental contribution of the proposed action is
                expected to be very small due to the efficacy of the required remote-sensing survey and archaeological report.
                However, there is a possibility of an interaction between bottom-disturbing activity (rig emplacement, pipeline
                trenching, and anchoring) and a prehistoric archaeological site.

                Conclusion


                    The total of OCS program and non-program-related impact-producing factors have likely resulted in and
                may yet result in the loss of significant or unique prehistoric archaeological information.










                 IV-526

                 (11) Impacts on Socioeconomic Conditions

                 (a) Population, Labor, and Employment

                     The Cumulative Analysis will focus on the direct, indirect, and induced impacts of the OCS oil and gas
                 industry on the population, labor, and employment of the counties in the Western Gulf coasul impact area as
                 a result of prior sales, the proposed sales, and future sales in the Gulf of Mexico. Considered also are
                 employment impacts associated with the clean-up of oil spilled during import tankering operations. There
                 would also be other economic impacts, both direct and indirect, associated with the OCS program resulting
                 from its effect on other industries, such as commercial fishing, tourism, and recreational fishing. The direct
                 benefit or loss in these industries is addressed in the sections of this EIS related specificall, to those topics.
                 The OCS program's indirect and induced effect on these associated industries is much more difficult to
                 quantify. Nevertheless, it will generally constitute a fraction of the magnitude of the direct impact. Also
                 discussed in the Cumulative Analysis are projected changes in the industrial composition of the regional
                 economy.
                     Section III.C.1. provides an historical perspective of the oil and gas industry, as well as a brief description
                 of recent events that have significantly affected the level of OCS activity in the Gulf of Mexico. A detailed
                 discussion of historical trends in population, labor, and employment within the coastal impact area of the
                 Western Gulf can be found in Section III.C.2. That section also includes a listing of counties in the Western
                 Gulf coastal impact area, as well as current statistics and future projections of population, labor, and
                 employment levels for coastal subareas in the region. These projections will serve as a baseline against which
                 impacts will be measured. The methodology developed to quantify these impacts takes into account changes
                 in OCS-related employment, along with population and labor impacts resulting from these employment changes
                 within each individual coastal subarea. For a detailed description of the methodology used in this analysis, see
                 Section IV.D.2.a.(11).
                     Baseline employment projections for the coastal impact area of the Western Gulf can be found in Figure
                 IV-11. Baseline employment projections, excluding jobs generated in the WPA by the OCS program during
                 the 35-year life of the proposed action, are also displayed on this figure. The difference between these two
                 sets of projections accounts for OCS program employment impacts to the counties of the Western Gulf
                 resulting from prior sales, proposed sales, and future sales in the Central, Western, and Eastern Gulf of
                 Mexico. Sales in the Central Gulf can, and do, result in employment impacts to the Western Gulf. The
                 methodology discussion in Section IV.D.2.a.(l 1) provides an in-depth treatment of the development of these
                 projections.
                     A total of approximately 277,300 person-years of employment (direct, indirect, and induced) are required
                 in the Western Gulf coastal subareas in support of the OCS Program in the Gulf of Mexico during the 35-year
                 life of the proposed action. Peak-year impacts occur in 2000, with approximately 11,050 workers involved in
                 primary, secondary, and tertiary industries. After this initial peak-year employment, impacts decline through
                 the year 2027, reflecting the declining level of OCS-related oil and gas activity projected for the Western Gulf.
                 Direct employment in the primary oil and gas extraction industry (SIC 13) accounts for 45 percent of the total
                 employment impacts projected for the coastal subareas of the Western Gulf over the life of the proposed
                 action. Of these total direct employment impacts, exploratory and development activities collectively account
                 for almost 38 percent. Exploratory activities peak in the year 2000, contributing almost 46 percent of the direct
                 employment peak. Development operations peak five years later, in the year 2005. Production operations
                 peak in 1993, the first year of the life of the proposed actions. The main contributor to the overall total
                 employment impact is also production operations. Employment in oil and gas production activities and
                 workover operations account for approximately 62 percent of total direct employment impact due to activities
                 in the Western Gulf. Indirect and induced employment impacts in secondary and tertiary industries amount
                 to approximately 30 percent and 25 percent, respectively, of the total employment impact over the life of the
                 proposed action in the Western Gulf.
                     Table IV-31 displays the cumulative model projections of total OCS-related employment impacts (direct,
                 indirect, and induced) for each coastal subarea throughout the life of the proposed action. Table IV-32
















                                    5,000,000



                                                                          Baseline Projection                   Without OCS Program

                                                                                                                      -------------
                                    4,500,000






                                    4,000,000





                               E
                               >%   3,500,000
                               .9
                               CL
                               E
                               LU




                                    3,000,000






                                    2j5OOvOOO
                                                                                                                                                                 to     A
                                              114P -COP                   le     le lop                                                                               I&,
                                                                                                           YON



                  Figure IV-11. Employment Impacts from the OCS Program (Western Planning Area) (USDOI, MMS, Gulf of Mexico
                                      OCS Region estimates, 1991).










                  IV-528

                  provides estimates of annual impacts to the population and employment of each coastal subarea as a percent
                  of levels expected in absence of the OCS program. These impact estimates represent changes in the new share
                  of the existing population and employment, changes that will be dependent on the OCS oil and gas industry
                  for support as a result of prior sales, the proposed sales, and future sales in the Gulf of Mexico. The
                  Cumulative scenario's population and employment impact projections presented in this document are higher
                  than those estimated for recent past EIS's. The current analysis incorporates the benefit of improved
                  information on employment levels associated with existing offshore structures and workover operations. These
                  data improvements account for the larger impact projections.
                      The greatest contributor to the overall employment impact in the Western Gulf is - coastal Subarea W-2,
                  which accounts for about 84 percent of the total planning area impact expected for the Cumulative Case.
                  Coastal Subarea W-1 contributes the remaining 16 percent Peak-year impacts of 0.4 and 0.3 percent occur
                  in both coastal Subareas W-1 and W-2, respectively, during most of the first 10 years of the life of the proposed
                  action.
                      AD coastal subareas of the Western Gulf are projected to experience peak-year employment impacts of
                  less than I percent due to activity resulting from prior sales, the proposed sales, and future sales in the Gulf
                  ofMexico. New OCS development will allow the continuation of some opportunities in the oil and gas industry
                  for currently employed workers or future entrants into the labor force already living in the area. After their
                  peak in the year 2000, the level of OCS-related employment projected for the Western Gulf will continue to
                  diminish as existing hydrocarbon resources become depleted. Continued leasing in the OCS, will only partially
                  offset the decline in available oil- and gas-related employment in the counties of the WPA,
                      Employment impacts resulting from oil-spill clean-up activities, because of their highly unpredictable nature,
                  were handled apart from the population and employment model. The level of employment associated with
                  any given clean-up operation is dependent on numerous variables which, in themselves, are also difficult to
                  predict. Nevertheless, the most labor-intensive clean-up operations are those from spill-; that contact the
                  coastline, particularly recreational beaches. For the purpose of this analysis, it is assumed that only those spills
                  contacting land will involve significant manpower requirements in their clean-up efforts.
                      Section IV.C.1. presents estimates of the mean number of offshore spills assumed to occur as a result of
                  the Cumulative Case in the Gulf. The estimated probability that one or more offshore spills greater than or
                  equal to 1,000 bbl from import tankering will occur and contact land segments of the Western Gulf within 10
                  days of the accident can be found in Table IV-22. The highest probability that an offshore spill of this size
                  resulting from the OCS program will occur and contact a WPA land segment within 10 da, is 8 percent for
                                                                                                                  Ys
                  Galveston and Chambers Counties (Land Segment 10) in coastal Subarea W-2. Calhoun County (Land
                  Segment 7) in coastal Subarea W-1 carries the second highest probability of occurrence and contact within 10
                  days, with a probability of 3 percent. Based on these low probabilities, the assumption is that no offshore spin
                  of this size category will occur and contact land somewhere in the WPA as a direct result of the OCS program.
                      The highest probability that an offshore spill greater than or equal to 1,000 bbl will oa-ur from accidents
                  involving import tankering and contact a WPA land segment within 10 days is 22 percentfor Galveston and
                  Chambers Counties (Land Segment 10) in coastal Subarea W-2. All remaining counties have a probability of
                  occurrence and contact within 10 days of less than 10 percent. Aransas County (Land Segment 6), in coastal
                  Subarea W-1, has the second highest probability of occurrence and contact within 10 days, 9 percent. Based
                  on these probabilities, the assumption is that one offshore spill of approximately 22,728 bbl will occur from
                  import tankering operations and contact a land segment somewhere in the WPA. An MMS study of oil slick
                  sizes and length of affected coastline provides statistics that lead to the assumption that, on average, a spill of
                  this size would affect approximately 50 km of coastline (USDOI, MMS, 1985c). Based on employment statistics
                  from recent spill clean-up operations along the coast, the assumption is also made that, for every kilometer of
                  coastline subjected to heavy oiling, approximately 100 temporary workers would be employed for a maximum
                  of 6 weeks. Thus, an estimated 5,000 workers would spend approximately 6 weeks employed in operations
                  supporting the clean-up of one OCS-related spill greater than or equal to 1,000 bbl that is assumed to contact
                  the Western Gulf coast This estimate is equivalent to 580 person-years of employment over the life of the
                  proposed action. Assuming the spill occurred at the height of employment impacts to coastal Subarea W-2.
                  total impacts would still be less than 1 percent of the employment levels assumed that year in absence of the
                  OCS program in coastal Subarea W-2.










                                                                                                                               IV-529

                     No offshore spills of the size category greater than 50 bbl and less than 1,000 bbl are assumed to occur
                and contact the Western Gulf co    ,astline. One-hundred and eighty three spills of the size category greater than
                1 bbl and less than or equal to 50 bbl are assumed to occur each year in the WPA over the life of the proposed
                action. Of these spills, only a few are assumed to contact land (Section IV.C.1.). Furthermore, employment
                impacts resulting from the cleanup of spills this small is assumed to be negligible.
                     In addition to the spills referenced in Table IV-22, a number of crude oil and petroleum product spills of
                less than 1,000 bbl and greater than and equal to 1,000 bbl are assumed to occur, primarily in the coastal zone.
                Estimates regarding the size, source, and potential location of these spills can be found in Section IV.C.1. The
                level of clean-up action associated with spills of this type will vary.
                     Employment levels in the impact area of the Western Gulf are expected to increase approximately 77
                percent from the year 1990 over the life of the proposed action (Section III.C.2.). Projected changes in the
                industrial composition of the regional economy are considerable (USDOC, Bureau of Economic Analysis,
                1990). The mining sector will sustain a significant reduction in employment levels. By the year 2020, mining
                employment in the State of Texas is projected to decrease by about 16 percent from 1988 levels. The sector
                of highest growth in Texas through the year 2020 will very likely be the service industry, which includes
                establishments primarily engaged in providing a wide variety of services for individuals, business, government,
                and other organizations. Included in this sector are establishments highly dependent on the tourist industry,
                such as hotels and other lodging places, recreational camps and parks, amusement services, museums, art
                galleries, zoological gardens, automotive rental agencies, business advertising, and other miscellaneous personal
                services. By the year 2020, the service industry is expected to grow by about 40 percent from employment
                levels experienced in 1988. Retail trade, finance, insurance and real estate, and transportation and public
                utilities are also projected to exhibit considerable growth over this time period.
                     Population in the impact area of the Western Gulf is expected to increase approximately 52 percent from
                the year 1990 over the life of the proposed action (Section III.C.2.). Population impacts from activities
                associated with the OCS Program are expected to be relatively low in the Western Gulf. Peak-year population
                impacts for coastal Subareas W-1 and W-2 are estimated to be 0.4 and 0.3 percent, respectively.

                Summa7y

                     From a cumulative standpoint, the OCS program has had a much lower impact on the coastal subareas
                of the Western Gulf than on those of the Central Gulf. Peak annual changes in the population, labor, and
                employment of all coastal subareas in the Western Gulf represent less than 1 percent of the levels expected
                in absence of the OCS program in the Gulf of Mexico. As much as 13 percent of activity in offshore Subarea
                W-1, 47 percent of activity in offshore Subarea W-2, and 83 percent of activity in offshore Subarea W-3 is
                supported by the coastal subareas of the Central Gulf (coastal Subareas C-1 and C-2). It appears that the
                growth in employment to levels expected in the year 2000 will represent the peak impact of the OCS program
                over the life of the proposed action. Employment needs in support of OCS oil and gas activity are likely to
                be met with the existing population and available labor force. Future OCS leasing is expected to offset only
                partially the declining level of activity already taking place in the oil and gas industry offshore. Similar declining
                trends are projected for off and gas production in State waters.
                     In light of the past and projected decline in oil and gas activities in the Western Gulf, there have been
                numerous and significant efforts to diversify the State's economy. A diversified economy will provide the
                coastal communities the opportunity to achieve net economic growth in spite of the downturn in the oil and
                gas industry. The service industry, in particular, is projected to experience significant growth in the region over
                the life of the proposed action.
                     The cumulative impact from prior sales, the proposed actions, and future sales on the population, labor,
                and employment of the counties of the Western Gulf coastal impact area is approximately 277,300 person-years
                of employment over the life of the proposed action. The incremental contribution of the proposed action (as
                analyzed in Section IV.D.2.a.(11)(a)) to the cumulative impact level is minimal because peak annual changes
                in the population, labor, and employment of all coastal subareas in the Central and Western Gulf resulting
                from the proposed action in the Western Gulf represent less than 1 percent of the levels expected in absence
                of the proposal.










                  IV-530


                  Conclusion


                      The Cumulative Analysis impact from prior sales, the proposed actions, and future sales on the population,
                  labor, and employment of the counties of the coastal impact area is approximately 277,300 person-years of
                  employment over the life of the proposed action. Employment needs in support of OCS oil and gas activity
                  are likely to be met with the existing population and the available labor force.

                  (b) Public Services and Infrastructure

                      The Cumulative Analysis considers the effects of OCS-related, impact-producing factors from the Central,
                  Western, and Eastern Gulf of Mexico, as well as the effects of prior, current, and future OCS sales and the
                  effects of non-OCS-related impact-producing factors. Impact-producing factors considered in the analysis
                  include work force fluctuations, net migration, relative income, oil and gas activity from State waters, wetlands
                  loss, and tropical storms. Unexpected events (such as the 1973 Arab Oil Embargo) may influence oil and gas
                  activity within the Gulf of Mexico Region. These events cannot be projected and will not be considered in this
                  analysis.
                      Public services and infrastructure, as used in this analysis, include commonly provided public, semipublic,
                  and private services and facilities, such as education, police and fire protection, sewage treatment, solid-waste
                  disposal, water supply, recreation, transportation, health care, other utilities, and housing. Changes in OCS
                  activities as well as changes caused by non-OCS-related, impact-producing factors, could result in changes in
                  demands for and usage of public services and infrastructure. Adverse effects could arise if the amount or rate
                  of increase or decrease in the usage significantly exceeded or fell far below the capability of a local area to
                  provide a satisfactory level of service. In addition, a natural disaster, such as a hurricane, could significantly
                  damage infrastructure and create a greater need for service than would be locally available.
                      Section III.C.1. provides an historical perspective of the oil and gas industry, as well as a brief description
                  of recent events that have significantly affected the level of OCS activity in the Gulf of Mexico. Discussions
                  of population, labor, and employment; public services; and social patterns are presented in Section III.C.2.
                      As shown in Table IV-35, approximately 277,303 person-years of employment (direct, indirect, and induced)
                  are required in the coastal subareas of the Western Gulf to support OCS-related activities during the 35-year
                  life of the proposed action. Peak-year impacts occur in 2000, with 11,041 workers involved in primary,
                  secondary, and tertiary industries. A breakdown of total employment projections for the life. of the proposed
                  action by coastal subarea reveals total employment of 16 percent in Subarea W-1 and 84 p--rcent in Subarea
                  W-2. Examination of Table IV-34 reveals that the impact to employment is 0.4 percent in coastal Subareas
                  W-1 and 0.3 percent in coastal Subarea W-2 during the peak year (2000) of the life of the proposed action.
                  It is expected that the level of OCS-related employment projected for the WPA will diminish as existing
                  hydrocarbon resources become depleted. It is assumed that continued leasing in the OCS will only partially
                  offset the decline in available OCS-related oft and gas employment.
                      Fluctuations in the work force as a result of changing levels of OCS-related oil and gas activity could
                  impact public services and infrastructure during the life of the proposed action. As mentioned above, following
                  the peak year (2000), total employment in the WPA is expected to decline. Projected changes in the industrial
                  composition of the regional economy over the life of the proposed action reveal a decrease in mining
                  employment in Texas of about 16 percent from 1988 levels (USDOC, Bureau of Economic Analysis, 1990).
                  The highest growth industry in the WPA is expected to be the service industry. It is assumed for the purpose
                  of analysis that the jobs created in the service sector will be lower paying than jobs in OCS-related activities.
                  This development could result in a lower tax base, making financing for new infrastructure needed in response
                  to normal growth problematic. However, the more diversified economy is expected to buffer the effects of the
                  decline in OCS-related employment.
                      Peak-year cumulative impacts are expected to be maintained from 1993 to 2002. Following this period,
                  total OCS-related oil and gas employment in the WPA is expected to decline. As mentioned above, projected
                  levels of mining employment in Texas are expected to drop by 16 percent by 2020. Expected growth in the
                  service industry will most likely provide employment for some of the work force; however, it is assumed that










                                                                                                                            IV-531

                 a small amount of out-migration will occur among those persons seeking pay comparable to that of OCS-
                 related employment It is expected that the diversified economy of the WPA will provide the opportunity for
                 coastal communities to achieve net economic growth despite the projected downturn in OCS-related activities.
                 Out-migration as a direct result of lower employment in the OCS oil and gas industry is not expected to occur
                 in large amounts.
                     The relatively high wages paid to OCS-related oil and gas industry personnel in the cumulative case will
                 serve to increase the tax base in the coastal parishes and counties beyond what could be expected if there were
                 no OCS activities. As OCS-related employment decreases through time, it is assumed that taxes originating
                 from OCS-related wages and expenditures will decrease. Consequently, maintenance of existing infrastructure
                 and creation of new infrastructure may become problematic.
                     Oil and gas activity within State waters requires similar public services and infrastructure as do OCS-related
                 oil and gas activities. Further, it is assumed that oil and gas employment from activities within State waters
                 will decline at the same rate, if not faster, than that from Federal OCS waters. Infrastructure needs in support
                 of oil and gas activities in State waters would diminish as employment associated with State-regulated activities
                 declines. Impacts to public services would include increased numbers of individuals requiring assistance. In
                 addition, maintenance of the existing infrastructure and the creation of new infrastructure may become difficult
                 to support at different levels of oil and gas employment.
                     About one-third of the WPA coast was hit with 16-20 tropical cyclones between the years 1901 and 1955
                 (DeWald, 1982). The other two-thirds had a slightly lower incidence of cyclones (11-15). Experience with
                 Hurricanes Carla and Beulah has indicated that major hurricanes can have a devastating effect on both public
                 services and community infrastructure. Assuming that several major storms will impact the Western Gulf
                 coastal subareas during the life of the proposed action necessitates an assessment of very high local impact
                 where these storms hit.
                     Coastal erosion and submergence appear to be the greatest factors in the loss of wetlands. Continuance
                 of these processes will likely result in some impact to community infrastructure, primarily roads and bridges
                 in proximity to coastal wetlands.

                 Summary

                     Several impact-producing factors will contribute to the impacts expected to occur to public services and
                 community infrastructure during the life of the proposed action.
                     Declining levels of OCS-related employment are expected to occur during the life of the proposed action.
                 The diversified economic base of the WPA is expected to buffer the effects of the declining growth in the OCS-
                 related oil and gas industry. Economic growth is expected to occur in the service industry.
                     It is assumed that a small amount of out-migration will coincide with declining levels of OCS-related
                 employment. Oil and gas activity within State waters is assumed to decline over the life of the proposed action.
                 Impacts to public services would occur as persons formerly employed required assistance. Impacts to
                 community infrastructure would occur as the lieed for the infrastructure diminished and funding for
                 maintenance and replacement declined.
                     Tropical storm activity has occurred in the past and will occur in the future. It is assumed that several
                 major storms will strike the WPA coastal counties during the life of the proposed action. Experience has
                 indicated that these storms could have a major short-term (1-3 years) impact on public services and community
                 infrastructure.
                     Community infrastructure in the coastal parishes           counties is linked to the region's physiography.
                 Continued coastal erosion and coastal submergence are expected to require expanded maintenance of roads,
                 bridges, and railroads.

                 Conclusion

                     The cumulative impact on public services and community infrastructure is not expected to result in long-
                 term (greater than 3 years) disruptions in delivery of public services or maintenance of community










                 IV-532

                 infrastructure because of the diversified local economy and the small percentage of impact of the OCS Program
                 on local employees and demographies.

                 (c) Social PaUerns

                     The Cumulative Analysis considers the effects of OCS-related, impact-producing factors from the Central,
                 Western, and Eastern Gulf of Mexico, as well as the effects of prior, current, and future OCS sales. The
                 analysis also considers the effects of certain non-OCS-related, impact-producing factors. Unexpected events
                 (such as the 1973 Arab Oil Embargo) may influence oil and gas activity within the Gulf of Mexico Region.
                 These events cannot be projected and cannot be presumed for this analysis.
                     Social patterns, as used in this analysis, will include traditional occupations, folkways, social structure,
                 language, family life, and other forms of cultural adaptation to the natural and human environment. It should
                 be noted that impacts not treated in the present analysis (such as technological improvements in
                 communications and transportation) have caused, and will continue to cause, changes within the analysis area.
                 For the purpose of the current analysis, impact-producing factors to social patterns will include work force
                 fluctuations, net migration (both in-migration and out-migration), work scheduling, displacement from
                 traditional occupations (primarily resulting from wetlands loss), relative income, oil and gas activity within State
                 waters, and tropical storms. Adverse effects could arise if disruption of social patterns occurred and resulted
                 in changes in traditional occupations, disruption in the viability of extant subcultures, and detrimental effects
                 on family life. As mentioned in Section III.C.2.c., it may be argued that employment in the oil and gas industry
                 could be perceived as a traditional occupation. For the purpose of this analysis, such employment will not be
                 considered as a traditional occupation.
                     Section III.C.1. provides an historical perspective of the oil and gas industry, as well as a brief description
                 of recent events that have significantly affected the level of OCS activity in the Gulf of Mexico. Discussions
                 of population, labor, and employment; public services; and social patterns are presented in Section III.C.2.
                     As stated in Section IV.13.2.d.(11)(a), approximately 277,300 person-years of employment (direct, indirect,
                 and induced) are required in the Western Gulf coastal subareas to support OCS-related activities during the
                 35-year life of the proposed action. Peak-year impacts occur in the year 2000, with approximately 11,050
                 workers involved in primary, secondary, and tertiary industries. A breakdown of total employment projections
                 for the life of the proposed action by coastal subarea reveals total employment of 16 percent. in Subarea W-1
                 and 84 percent in Subarea W-2. An examination of Table IV-34 reveals that the impact to employment ranges
                 from 0.4 percent in Subarea W-1 and 0.3 percent in W-2 in the peak year 2000 to 0.2 and 0.1 percent,
                 respectively, in 2027. Population impacts closely track employment impacts. It is expected that the level of
                 OCS-related employment projected for the WPA will diminish as existing hydrocarbon resources become
                 depleted. It is assumed that continued leasing in the OCS will only partially offset the decline in available
                 OCS-related oil and gas employment.
                     Fluctuations in the work force as    a result of changing levels of OCS-related oil and gas activity could
                 impact social patterns and infrastructure during the life of the proposed action. As mentioned above, total
                 employment in the WPA is expected to decline after the peak year (2000). Projected changes in the industrial
                 composition of the regional economy over the life of the proposed action reveal a decrease in mining
                 employment in Texas of about 16 percent from 1988 levels (USDOC, Bureau of Economic Analysis, 1990).
                 The highest growth industry in the WPA is expected to be the service industry. It is assumed. for the purpose
                 of analysis that the jobs created in the service sector will be lower paying than jobs in OCS-related activities.
                 The quality of family life, in some individual cases, could be adversely affected from the stress resulting from
                 decreased family income and loss of security resulting from layoffs in the OCS oil and gas industry. However,
                 the more diversified economy in the WPA is expected to buffer the effects of the decline in OCS-related
                 employment.
                     Peak-year cumulative impacts are expected to occur in the year 2000. Following the peak year, total
                 employment in the WPA is expected to decline in OCS-related oil and gas employment. As mentioned above,
                 projected levels of mining employment in Texas are expected to drop by 16 percent by 2020. Expected growth
                 in the service industry will most likely provide employment for some of the work force; however, it is assumed










                                                                                                                           IV-533

                that a small amount of out-migration will occur among those persons seeking pay comparable to that of OCS-
                related employment It is expected that the diversified economy of the WPA will provide the opportunity for
                coastal communities to achieve net economic growth despite the projected downturn in OCS-related activities.
                Out-migration as a direct result of lower employment in the OCS oil and gas industry is not expected to occur
                in large amounts.
                    Distance to the site and the type of transportation needed for personnel in OCS-related oil and gas
                activities results in the normal work schedule occurring as a large block of time on duty (or at site) followed
                by a large block of time off duty. The schedules may range from 7 days on followed by 7 days off to a 30 day
                on/30 day off schedule. It has been argued that this type of schedule has allowed for participation in, and
                continuance of, traditional occupations (Hallowell, 1979; Laska, personal comm., 1991). It is expected that
                stress will be placed on family life in response to the regular absences of a parent (usually the father). In some
                cases, it is expected that adaptation to changing family roles will occur. In other cases, it is expected that
                adaptation will not occur and that there will be deleterious impacts to family life. In the peak year of 2000,
                approximately 11,050 workers are projected to be involved in primary, secondary, and tertiary industries.
                Employment in oil and gas production activities and workover operations is projected to account for about 62
                percent of this total. Of those persons employed in OCS-related oil and gas activities and working the
                extended schedule, it is expected that some families will not adapt to these conditions and that deleterious
                impacts to family fife will occur.
                    The relatively high wages paid to OCS-related oil and gas industry personnel in the cumulative case may
                result in the voluntary shift of persons engaged in traditional occupations to more lucrative positions within the
                oil and gas industry. Dependency on these relatively high wages may have a deleterious impact on family life,
                particularly in view of the projected decline in OCS-related oil and gas activity over the fife of the proposed
                action. Some individual cases of serious impairment of family life are expected to occur in association with
                those persons who, laid off from OCS-related oft and gas activities, cannot find jobs at comparable pay.
                    Oil and gas activity within State waters is assumed to result in adverse effects as do OCS-related oil and
                gas activity. It is assumed the oil and gas employment from activities within State waters will decline at the
                same rate, if not faster, than that from Federal OCS waters. As employment from these activities decline
                through time, it is expected that the diversified economy of the WPA will absorb most of these personneL It
                is expected that some of those former OCS personnel will engage in full-time participation in traditional
                occupations. Serious impacts to family life would be expected in some individual cases involving the layoff of
                personnel working for oil and gas industries associated with State jurisdiction.
                    About one-third of the WPA coast was hit with 16-20 tropical cyclones between the years 1901-1955
                (DeWald, 1982). The other two-thirds had a slightly lower incidence of cyclones (11-15). Experience with
                hurricanes in the historical record (such as the 1900 hurricane that destroyed Galveston) and more recent,
                storms such as Hurricanes Carla and Beulah has indicated that major hurricanes can have a devastating effect
                on both the natural and human environment. Temporary disruption of traditional occupations and severe
                impairment of family life, in some individual cases, can result from the effects of tropical storms. It is assumed
                that several major storms will impact the Western Gulf coastal subareas during the life of the proposed action.
                    Displacement from traditional occupations could originate from destruction of a resource base, space-use
                conflict, and voluntary shifts from traditional occupations to employment in OCS-related activities. Adverse
                effects resulting from the displacement from traditional occupations could include a diminishment in the
                number of participants in traditional occupations, the loss of traditional knowledge and cultural heritage, and
                deleterious impacts to family life. The existence of the Fisherman's Contingency Fund mitigates, to some
                extent, space-use conflicts associated with commercial fishing. A total of 1,640 claims was filed as of 1990, of
                these, 407 originated in the Western Gulf of Mexico. Section IV.D.Ld.(1)(b) states that the expected
                cumulative impact to coastal wetlands is expected to be moderate. Coastal erosion and submergence appear
                to be the greatest factors in the loss of wetlands. Continuance of these processes will likely result in some
                impact to traditional occupations in the WPA over the life of the proposed action, resulting in the serious
                impairment of family life in some individual cases.










                 IV-534

                 Summary

                      Several impact-producing factors will contribute to impacts on social patterns during the life of the
                 proposed action.
                      Declining levels in OCS-related employment are expected to occur during the life of the proposed action.
                 Economic growth is expected to occur in the service industry. The diversified economic base of the WPA is
                 expected to buffer the effects of declining growth in the OCS-related oil and gas industr@ to some extent.
                 However some deleterious impact to family life is expected to occur in individual cases.
                      It is assumed that a small amount of out-migration will coincide with declining levels of OCS-related
                 employment. Given the low percentage of projected impacts on total population and emplo,
                                                                                                                yment from OCS-
                 related activities and the diversified economic base of the WPA, minimal impacts from migration on social
                 patterns is expected.
                      Adverse effects from relative wages are expected to be greatest among families who have grown dependent
                 upon the relatively high level of wage paid to persons employed by OCS-related industries. Serious
                 impairment of family life is expected to occur in some individual cases.
                      Oil and gas activity within State waters is assumed to decline over the life of the proposed action. Impact-
                 producing factors are expected to parallel those found for activity in Federal OCS waters. 'Me level of impact
                 is also expected to parallel that for OCS-related activities.
                      It is assumed that several tropical storms will make contact with the WPA coastal subareas during the life
                 of the proposed action. Experience has shown that these storms can have a devastating, but temporary, impact
                 on traditional occupations. Serious impairment of family life is expected to occur in some individual cases.
                      Displacement from traditional occupations could occur as a result of the destruction of the resource base
                 (primarily loss of wetlands), space-use conflicts, and voluntaryshifts from traditional occupations to OCS-related
                 employment. The loss of wetlands under the cumulative case is expected to be a few hundred hectares. This
                 loss, through time, is expected to have some deleterious impacts on family life in some individual cases.
                      The incremental contribution of the proposed action (as analyzed for the Base Case in Section
                 IV.D.2.a.(11)(c)) to the cumulative impact level is minimal because there are no expected dramatic short-term
                 increases or decreases in population of the coastal parishes and counties. In addition, minimal net migration
                 into the coastal subareas is expected, and jobs created by the proposed action will reduce out-migration. The
                 extended work schedules and relatively high wages associated with OCS-related employment will cause minor
                 displacement from traditional occupations.

                 Conclusion

                      Under the Cumulative scenario, it is expected that some displacement from traditional occupations will
                 occur. Deleterious impacts to family life are also expected to occur in some individual cases.

                 f. Coastal Zone Management Plans and Land Use

                      Coastal management policies apply to Sale 143 and to all subsequent activities that affect uses or resources
                 of the coastal zone. Section III.C.6. contains an overview of State Coastal Zone Management Plans.
                      The following assessment focuses on the hypothetical direct and indirect effects of postlease activities (the
                 Base Case scenario of the EIS). Changes made by the lessees as they explore, develop, and produce petroleum
                 products from leases offered in Sale 143 would affect the applicability of this assessment. The MMS is
                 generally prohibited from issuing drilling permits until after the consistency certification review is completed
                 and affirmed by a State. Additional information on the Base Case scenario can be found hi Section W.A.










                                                                                                                             IV-535

                 (1) Louisiana

                     The sale analysis area adjacent to the submerged lands of the State of Louisiana is the Central Planning
                 Area, made up of Central Coastal Subareas C-1, C-2, and C-3, which extend offshore from the State 3-mi line.
                 Twenty-one coastal parishes of Louisiana are involved.
                     Appendix C2 of the Louisiana Coastal Zone Management Plan (LCZMP) outlines the rules and
                 procedures for the State's local coastal management programs. Under the LCZMP, parishes are authorized,
                 though not required, to develop local coastal management programs. Approval of these programs gives the
                 parishes greater authority in regulating coastal development projects that entail uses of local concern.
                 Priorities, objectives, and policies of use of local land use plans must be consistent with the policies and
                 objectives of Act 361 and the State guidelines, except for a variance adopted in Section IV.D. of Appendix C2.
                 The Secretaries of the Departments of Natural Resources and Wildlife and Fisheries may jointly rule on an
                 inconsistent local program based on local environmental conditions or user practices.
                     State and Federal agencies first review parish programs before they are adopted. According to NOAA
                 the State of Louisiana has seven approved local coastal management programs (Lafourche, Jefferson,
                 Calcasieu, Orleans, Cameron, St. Bernard, and St. James Parishes). Two others, St. Charles and St. Tammany,
                 are pending NOAA approval. The parish police jury often serves as the permitting agency for projects limited
                 to local concern. Parish level programs function in an advisory capacity to Louisiana's CZM agency, the
                 Coastal Management Division. The energy facility planning process is comprehensively outlined in Appendix
                 E of the LCZMP. Conflicts with local land use plans or ordinances are not expected to occur as a result of
                 Sale 143, as existing onshore infrastructure is expected to be sufficient.
                     There is currently considerable local concern in the State of Louisiana about OCS waste onshore disposal
                 practices. If OCS drilling and production wastes cannot meet the U.S. Environmental Protection Agency's
                 NPDES effluent limitations or if these limitations require zero offshore discharge, offshore operational wastes
                 must be transported to shore for onshore disposal.
                     New proposed effluent limitations and the changes to current disposal practices are discussed in Section
                 IV.A.2.d.(5). It is expected that OCS waste resulting from Sale 143 leases would be properly disposed of in
                 approved landfills onshore. Onshore disposal of offshore waste products would be in accordance with USEPA's
                 proposed effluent regulations (40 CFR 435), which list preferred options for each type of waste.
                     Issues identified in LCZMP include the following: general coastal use guidelines; levees; linear facilities
                 (pipelines); dredged spoil deposition; shoreline modifications, surface alteration, hydrologic and sediment
                 transport modifications; waste disposal; uses that result in the alteration of waters draining into coastal waters;
                 off, gas, and other mineral activities; and air and water quality.
                     Assumptions fully discussed in Sections IV.A. and IV.C. indicate that proposed Sale 143 will generate the
                 impacting factors discussed below. These factors will affect coastal issues identified in the LCZMP.

                 Coastal Use Guidelines


                     Guidelines Applicable to All Uses (1. 1 through 1. 10)

                     General guidelines provide basic policy direction for the use of subsequent guidelines. Guidelines 1.1
                 through 1.3 apply to the determination of consistency for this proposal. Guideline 1.2, consistency with
                 incorporated air and water quality statutes and standards, is also addressed later in this discussion. Guidelines
                 1.4 and 1.5, regarding taking of property or violations of the terms of a grant of lands or water bottoms, are
                 not applicable because no such activities are included or will result from this lease sale.
                     Guideline 1.6 lists the general factors that the permitting authority will use in evaluating whether a
                 proposed use is consistent with other guidelines. Nineteen factors are listed. Examples are as follows:

                          "a)      type, nature and location of use."

                          "b)      elevation, soil and water conditions and flood and storm hazard characteristics of
                                   site."










                 IV-536

                  g)      economic need for use and extent of impacts of use on economy of locality."

                          existence of necessary infrastructure to support the use and public costs resulting from
                          use."


                 "l)      proximity to and extent of impacts on important natural features such. as beaches,
                          barrier islands, tidal passes .....

                 "in)     extent to which regional, state and national interests are served

                 wp)      proximity to and extent of impacts on public lands or historic, recreational or cultural
                          resources."


             Additionally, six of the factors deal with effects of the use. Much of the information cited above concerns
        activities for which specific information is not available at the lease sale stage.
             Guideline 1.7 lists 21 categories of adverse effects that potential land and water uses in the coastal zone
        should avoid creating, to the maximum extent possible.
             As previously indicated, no new support facilities are expected in Louisiana's coastal zone as a result of
        this lease sale (EIS Base Case scenario). Transportation of equipment and materials to support offshore
        operations is expected to use existing navigation channels through coastal areas. These operations would have
        only minor incremental effects relative to existing facilities.
             The primary factor of concern for sensitive coastal habitats is contact by accidental oil spills. Ari oil-spill
        risk analysis, detailed information concerning oil spills and spill containment and cleanup methods, is included
        in Section IV.C. Predictive results of a computer model run for the EIS analysis, described below and used
        throughoutthe rest of this document, assume that no efforts are made to contain or clean up spills or otherwise
        protect sensitive resources from spill contact.
             The mean number of spills over 1,000 bbl estimated to occur in the Central Gulf from Sale 142 is 0.18.
        This EIS indicates that the sale could result in an approximate 2 percent probability of accidental spills
        occurring and contacting within 10 days the coast of Louisiana within 10 days. Further, oil spills greater than
        or equal to 1,000 bbI that may occur as a result of an accident during exploration or development activities are
        not assumed to contact coastal habitats proximal to the sale area.
             There is no direct relationship between offshore oil and gas activities and wetlands destruction. Therefore,
        it is impossible to determine direct wetland impacts from a specific offshore activity. Offshore activities would
        be located away from coastal wetlands. The MMS has no jurisdictional or permitting involvement in any
        possible coastal wetlands mitigation activities in the State of Louisiana. Coastal zone impacts are documented
        by the State in its Coastal Use Permitting Process.
             Many researchers believe that restoring sediment to the wetlands would solve much of the land loss
        problem and even result in a significant wetlands gain (Cleveland et al., 1981). The MMS has funded a study
        to determine the effects of pipeline and navigation channels on barrier beach erosion along the Gulf Coast
        from Texas to the Florida panhandle (Wicker et al., 1989). This study showed zero-to-minimal impacts from
        OCS activities on the Louisiana barrier coast. The MMS is funding additional research to evaluate the effects
        of backfilling OCS channels to restore living resources and enhance fisheries habitat. The MMS has also
        funded a major study of the effects of marsh management practices on wetlands (Cahoon and Groat, 1990).
             No new nearshore pipelines are expected to be emplaced nor are new channels expected to be dredged.
        Maintenance dredging in existing navigation channels in Louisiana could adversely affect wetlands if the
        dredged material is disposed of in continuous spoil banks. New OCS-related pipeline and navigation channel
        projects in coastal Louisiana will occur much more infrequently than in the past because the network currently
        in place is adequate to accommodate oil and gas production from future resource development. One channel
        in the Port Fourchon area will be deepened to accommodate larger vessels. The potential contribution of
        support activities during exploration and/or production on these offshore leases, as compared to all navigation
        use of channels, is likely to be very small and will be subject to later State consistency certification review.
             Offshore structures enhance long-term biological productivity due to creation of reef habitat. The State










                                                                                                                              IV-537

                of Louisiana has been a leader in establishment of an artificial reef program, recognizing the value of offshore
                platforms to the commercial and recreational fishing industries.
                    The northern Gulf coastal zone is one of the major recreational regions of the United States, particularly
                in connection with marine fishing and beach-related activities. Marine debris lost from operations associated
                with drilling and production offshore may occur from time-to-time; however, the effect of intermittent washup
                of debris on the recreational use of Louisiana beaches should be low. The regulations at 30 CFR 250.40
                require that offshore operators handle, control, mark, and dispose of containers, equipment, and solid waste
                through stringent marking, equipment handling, and storage requirements. The MMS inspectors check for
                compliance with regulations during daffy offshore inspections. Failure to comply with regulations leads to
                official warnings to take corrective action or, if warranted, to cease operations.
                    Deliberate disposal of any solid waste or garbage items anywhere in the marine environment is strictly
                prohibited under existing MMS, EPA, and Coast Guard regulations. Because of increased concern with the
                prevalence and effects of persistent marine debris both offshore and on coastal beaches, MMS issued a special
                advisory (Notice to Lessees No. 86-11) in 1986 strongly encouraging the oil and gas industry to take special
                educational, operational, and awareness measures designed to reduce or eliminate their contributions to marine
                debris in the Gulf of Mexico. Annex V of the International Convention for the Prevention of Pollution from
                Ships, also known as the NLARPOL Protocol, prohibits the dumping of all plastic wastes, including plastic
                packaging materials and fishing gear, from all ships at sea. The MMS has established a policy that requires
                submission, for approval, of detailed plans for the disposal of all produced solids accumulated as a result of
                OCS activities (LTL dated November 20, 1990).
                    From information collected at beach cleanups and during marine debris surveys, it has been estimated that
                existing offshore oil and gas operations are responsible for 10-15 percent of the trash and debris adversely
                affecting the Gulfs shorefront recreational beaches in the CPA. Recent Federal regulations (33 CFR 151)
                stemming from NLARPOL Annex V, as well as periodic MMS directives and information seminars on the debris
                issue, should lead to better waste handling and less accidental loss of materials and personal items into the
                marine environment from offshore oil and gas operations. Additionally, industry education and training
                emphasis on waste management, along with voluntary stewardship commitments by several major oil companies
                (the adoption of about 30 mi of Louisiana Gulf beaches and the reduction and recycling of waste materials
                generated offshore), will also be reflected in a positive way on Louisiana's beaches.
                    Activities on these offshore leases are not expected to have a significant effect on coastal fishery resources.
                In addition, the effects on fishery resources beyond the coastal zone are likely to be minimal. State review of
                consistency certifications of exploration and development and production plans will enable more detailed review
                of site-specific proposed activities as they relate to fisheries and fishing practices. Federal provisions concerning
                fisheries include the Fishermen's Contingency Fund, which requires payment to fishermen for documented
                damages, and 30 CFR 250.40, which requires the charting of subsea obstructions and the marking of equipment
                to establish liability for fisheries losses.
                    Biological stipulations proposed for the sale (Section 11) contain special provisions for the regulation of
                discharges and siting of facilities within offshore areas recognized as areas of exceptional biological productivity.
                These stipulations will help to protect fisheries resources. Studies of mud (NRC, 1983; Zingula, 1975; Menzie,
                1983) and cutting discharges from offshore oil and gas operations show rapid dispersal by ocean currents with
                no long-term, significant biological effects.
                    An archaeological resource stipulation has been proposed that will require surveys for investigation and
                avoidance or protection of cultural resources on the OCS. The State Office of Historic Preservation will have
                opportunities to consult with MMS on protection of onshore historic resources, if development is proposed on
                any lease.
                    In addition, the lease sale may create new jobs and may generate other economic opportunities to the
                benefit of Louisiana and the Nation. An MMS-funded study (Laska, in progress) evaluates the effect of the
                downturn in the oil industry on the Gulf economy and investigates alternate uses of existing OCS infrastructure
                for economic development opportunities. Any change of existing social patterns in coastal Louisiana as a result
                of activities on these offshore leases is highly unlikely. The sale will result only in a continuation of existing
                facilities without notable alteration of social patterns because of currently unemployed and underemployed
                resources in the coastal zone. Jobs created as a result of the sale would likely reduce the amount of out-










                 IV-538

                 migration when compared to scenarios without the proposal. Economic considerations are also evaluated in
                 the Secretarial Issue Document and the Decision Memorandum for this sale.
                      The cumulative effects of the proposed actions that relate to the LCZMP are addressed. in Section IV.B.
                 This evaluation meets the criteria of "cumulative" as used in Guideline 1.7 of the LCZMP because it projects
                 all of the reasonably foreseeable effects of the sales including exploratory drilling, platform installation, support
                 vessel traffic, etc. A separate Cumulative Analysis required under NEPA considers a much broader scope of
                 effects, including proposed Sale 143; subsequent OCS oil and gas sales that are considered reasonably
                 foreseeable; prior OCS oil and gas sales; State oil and gas activity; crude oil imports by tankering; and all other
                 major non-OCS activities and occurrences that may occur and affect a resource in question.
                      The proposed lease stipulations, MMS rules and regulations (including requirements for off-spill
                 contingency planning, use of blowout preventers, Best Available and Safest Technology, crew training, and
                 other environmental safeguards), compliance with National Pollutant Discharge EliminationSystem (NPDES)
                 permits and standards, and other available Federal regulatory mechanisms will effectively mitigate the possible
                 effects of off and gas activities. Should new onshore facilities be needed for development of these leases, they
                 will be subject to State regulations and separate permits, including State consistency certification review.
                      Guideline 1.8 defines "to the maximum extent possible," a phrase that modifies many of the guidelines.
                 A use or activity will be consistent, although not fully complying with a standard, if it meels several criteria
                 relating to public benefit, or lacks feasible alternatives, or serves important local, State or national interests,
                 or is dependent on water. Federal regulations at 15 CFR 930.32 also define the term "maximum extent
                 practicable" and recognize there will be circumstances where full consistency with a State program is not
                 possi
                      Federal offshore oil and gas leasing serves an important national interest because future energy production
                 resulting from OCS development will help to reduce the Nation's reliance on foreign imports. The LCZMP,
                 through this policy, recognizes the relative importance of a national interest criterion in this guideline to the
                 extent that, even if a use or activity does not fully comply with a standard, it is consistent "to the maximum
                 extent possible."
                      Guideline 1.9 requires that uses be, to the maximum extent practicable, designed and carried out to permit
                 multiple uses and to avoid use conflict. This lease sale, as pointed out earlier, may eventually result in an
                 outcome that allows for multiple use and avoids use conflict. Offshore conflicts would be limited in scope
                 because certain multiple-use areas are off limits to oil and gas activities (e.g., shipping fairways and selected
                 military warning areas). Other multiple uses, such as boating and fishing, would result in only limited conflicts
                 because of the small areal extent of space used by oil and gas operations.

                      Guidelines for Levees (21 through 26)

                      The guidelines for levees apply to those constructed in the coastal zone. No levee construction activities
                 are expected to occur in Louisiana as a result of this lease sale. If any such activities were to be proposed in
                 Louisiana, the State would have opportunities to review such proposals through consistency certifications of
                 Corps of Engineers permits.

                      Guidelines for Linear Facilities (3.1 through 3.16)

                      Guidelines for linear facilities contain standards for State permitting of siting and installation of pipelines
                 located in onshore or nearshore coastal areas. Most of the production from this lease sale is projected to be
                 sent through existing trunklines for transportation to existing onshore processing facilities in the central and
                 western Gulf coastal areas. No new pipeline landfalls or onshore pipeline projects are anticipated. There may
                 be a small contribution (less than 5%) of barge and tanker operations transporting oil to offloading facilities
                 located at onshore terminals in Louisiana. Any new pipeline construction crossing submerged State lands must
                 be consistent with applicable State regulatory policies to ensure safety in construction and operation.
                      The Gulf Regional Technical Working Group (RTWG), which is an advisory committee, develops
                 transportation plans for OCS areas. One of the purposes of this coordinated planning effort is to establish
                 corridors for consolidating multiple pipelines, an effort aimed at minimizing seafloor obstructions and adverse











                                                                                                                             IV-539

                environmental effects. These and other efforts of RTWG, which include representatives from the State of
                Louisiana, help to ensure effective coordination on postlease pipeline-related activities.

                     Guidelines for Dredged Spoil Dqosition (4.1 through 4.7)

                     Guidelines apply to disposal of dredged material in the coastal zone. No new trunklines are expected from
                projected production on these offshore leases. No dredging solely related to activities taking place on Sale 143
                leases is projected to occur. Maintenance dredging of existing canals through barrier passes to accommodate
                vessel traffic to support the proposed action could alter littoral dynamics in the vicinity of the channel and
                could affect erosion and deposition patterns. Field studies, however, have not substantiated that dredging has
                resulted in coastal barrier erosion. In fact, the disposal of dredged material into the coastal, littoral transport
                system can be used to nourish sediment-starved and eroding coastal barriers. One canal in the Port Fourchon
                area may be deepened. Should any future exploration or development of Sale 143 leases involve disposal of
                dredged material, the State will have an opportunity to review such activities in its consistency certification
                process.

                     Guidelines for Shoreline Modifications (5.1 through 5.9)

                     These guidelines apply to shoreline modification and protection structures and to harbor structures. No
                such activities or facilities are expected to result from exploration or development activities on Sale 143 leases.
                Given the availability of existing harbor space, no new shoreline modifications are likely to be needed. If
                unforeseen postlease support facilities are proposed, the State will have opportunities to conduct consistency
                certification reviews.


                     Guidelines for Surface Alteration (61 through 614)

                     Guidelines for surface alterations contain two general guidelines (6.1 and 6.5) regarding development in
                the coastal zone.
                     Guideline 6.1 encourages industrial, commercial, and other development in suitable areas of the coastal
                zone. Suitable areas are defined as (a) to the maximum extent practicable, lands 5 ft or more above sea level
                or fast lands; or (b) those lands where suitable foundation conditions and minimum flood and storm damage
                risk are already developed or where development would not unreasonably endanger public safety; (c) areas
                having adequate infrastructure; or (d) having a tradition of similar use. Guideline 6.5 states that coastal
                water-dependent uses shall be given special consideration in permitting because of the reduced choice of
                alternatives. Most major postlease activities or facilities in the coastal zone are coastal water-dependent and
                industrial in nature. The consistency certifications contained in exploration and development and production
                plans will enable the State to review these activities for consistency.
                     Other surface alteration guidelines (6.2, 6.4, 6.6 through 6.10, and 6.12 through 6.14) are similar in scope
                to guidelines affecting pipeline siting and construction, They address siting, construction techniques, design
                characteristics aimed at avoiding natural features, and alteration of critical and biological resources.
                     As indicated earlier, no new support facilities are hypothesized to occur in Louisiana's coastal zone.
                However, should they be needed, the State will have opportunities to conduct consistency certification reviews
                and issue separate permits.

                     Guidelines for Hydrologic and Sediment Transport Modi Ications (7 1 through Z 9)
                                                                               fi

                     Hydrologic and sediment transport modification guidelines apply to water control structures and marsh-
                building schemes in the coastal zone. Although these guidelines are not applicable to this lease sale per se,
                because no such structures or activities are included or are likely to result, should a lessee propose development
                activities involving such modifications, he must obtain an affirmative State consistency certification review and
                other State permits.










                 IV-540

                      Guidelines for the Disposal of Wastes (8.1 through 8.9)

                      The guidelines for waste disposal apply to the location and operation of waste disposal facilities in the
                 coastal zone and the generation, transportation, treatment, storage, and disposal of hazard,DUS wastes. The
                 requirements and standards in NPDES permits (40 CFR 122) and the regulatory requirements of MMS (30
                 30 CFR 250.42) protect the quality of offshore waters. A variety of solid wastes are brought onshore for
                 disposal at nonhazardous oilfield waste (NOW) sites and landfills. Oil and gas waste are exerript from Federal
                 hazardouswaste regulations. Because of recent State regulations (LAC 33:IX.708, effective "March 20, 1991),
                 impacts from OCS produced waters should be minimized (Section IV.A.3.c.(4)(a)). Current levels of routine
                 point source and nonpoint source discharges are expected to continue because no new infrastructure is
                 projected (Section IVA.), and no new sources are expected from this proposal.
                      The oil and gas industry is the dominant supporter and participant in the Louisiana beach adoption and
                 cleanup program. Over three-fourths of Louisiana's adopted beaches and cleanup volunteers are directly
                 associated with the off companies (Amoco, Chevron, Conoco, CNG, Exxon, Fina, Kerr-McG-,e, Koch, LL&E,
                 Mobil, Shell, and Texaco). Furthermore, a special subcommittee of the Offshore Operators (Waste Handling
                 & Recycling) has been established to develop and to encourage industrywide strategies and procedures that
                 will reduce and improve the handling of waste materials generated offshore. For example, many offshore oil
                 and gas operators have eliminated the use of styrofoam drinking containers and food packaging materials and
                 have increased the use of bulk containers and compactors. Some companies are testing and implementing
                 comprehensive recycling projects for reusable waste generated offshore. Several ongoing surveys supported
                 and conducted by government, industry, academia, and environmental groups will help monitor industry's
                 record in handling, controlling, and disposing of solid waste and other items associated with offshore operations.
                 The MMS has taken a leading role in establishing the Take Pride Gulf Wide campaign working through the
                 Gulf of Mexico Program, in which all Gulf user groups are encouraged through education and participation
                 in stewardship projects to become part of the solution instead of the problem.

                      Guidelines for Uses that Result in the Alteration of Waters Draining into Coastal Waters (9.1 through 9.3)

                      The guidelines apply to water management programs and are not applicable to this lease sale because no
                 such programs are included in or will result from this lease sale.

                      Guidelines for Oi4 Gas, and Other Mineral Activities (10. 1 through 10. 14)

                      The guidelines for oil, gas, and other mineral activities address surveying, drilling, or refining activities in
                 the coastal zone and are not applicable to exploration, development, and production activities on the OCS that
                 may occur on Sale 143 leases.
                      However, some of the guidelines (10.3, 10.4, 10.9 through 10.12, and 10.14) could be applicable to the
                 extent that these are defirted as associated exploration, development, or production facifities, or activities.
                 Those guidelines that would apply to onshore facility development (10.3, 10.4, 10.9 and 10.10) are modified by
                 the terms "to the maximum extent practicable" or "best practical techniques." The applicable requirement is
                 for exploration and production facilities to be "designed and constructed using best practical techniques to
                 minimize adverse environmental impacts" to the coastal zone.
                      The EIS analysis indicates that projected adverse impacts of hypothetical, future offshore exploration,
                 development, and production operations on the Louisiana coastal zone are likely to be of a very low level.
                 Further, all OCS exploration, development, and production activities and/or associated facilities will be subject
                 to State consistency certification review if and when they are proposed.
                      Guideline 10.11 establishes an absolute requirement for environmental protection and emergency or
                 contingency plans for all mineral operations in the coastal zone. Sale 143, however, will not result in any oil,
                 gas, or other mineral operations in the State's coastal area, nor is there any expectation of new or expanded
                 shore bases or refining facilities. Existing Federal regulations (30 CFR 250.33, 250.34, and 250.42) establish
                 similar but more site-specific requirements for approval of such operations on OCS leases. An oil-spill
                 contingency plan (OSCP) is one such requirement. The OSCP's must be submitted for approval with, or prior










                                                                                                                        IV-541

              to, an exploration or development plan. The OSCP, outlining the availability of spill containment and cleanup
              equipment and trained personnel, is reviewed and updated annually. It must ensure that fun response
              capability could be committed during an off-spill emergency. This commitment would include specifications
              for appropriate equipment and materials, their availability, and the time needed for deployment. The plan
              must also include provisions for varying degrees of response effort, depending on the severity of a spill.
                  All OCS exploration or development and production plans will be subject to State consistency certification
              review and must describe how the operator proposes to comply with the environmental protection requirements
              of pertinent Federal statutory and regulatory requirements.
                  Guideline 10.12 prohibits the use of chemical agents on coastal zone oil spills without prior approval of
              the On-Scene Coordinator, in consultation with Louisiana and the USEPA, pursuant to the National Oil and
              Hazardous Substances Pollution Contingency Plan (40 CFR 112). This guideline duplicates similar Federal
              requirements.
                  Finally, Guidelines 10.13 and 10.14 address the restoration of mineral exploration or production sites and
              the avoidance of creating underwater obstructions in the coastal zone. No mineral exploration or production
              activities will be proposed in the coastal zone. However, on the OCS, offshore sites are subject to the Site
              Clearance requirements of MMS under NTL 90-01. Requirements established under this NTL ensure that
              any object (e.g., wellheads, platforms, etc.) installed on an OCS lease is properly removed and the site cleared
              so as not to conflict with other uses of the OCS.


              State Air and Water Quality Regulatory Provisions

                  Air Quality (Louisiana R.S. 30.1068,1081-1087)

                  State policy on air quality incorporated into the LCZMP is applicable to State onshore areas.
                  Section 5(a)(8) of the OCSIA grants DOI exclusive authority and responsibility to prescribe regulations
              requiring offshore sources of air emissions to be consistent with national ambient air quality standards to the
              extent offshore activities significantly affect the onshore air quality. Thus, the Department's regulations are
              the applicable air pollution control requirements of the LCZMP under Section 307(f) of CZMA for OCS
              emissions.
                  Oil and gas development and production activities on the OCS are required to meet Department air quality
              regulations (30 CFR 250.44, 250.45, and 250.46). These regulations require offshore lessees to determine
              through modeling whether their air emissions would result in onshore pollutant concentrations above
              Department-specified significance levels. If these levels are projected to be exceeded in an area where
              concentrations already exceed air quality standards, the lessee will be required to control fully or offset its
              emissions so that there would be no effect onshore. If the significance levels are exceeded in areas at present
              in compliance with standards, the lessee will be required to employ best available control technology (BACT).
              If predicted onshore concentrations still exceed a standard for the prevention of significant deterioration,
              measures beyond BACT will be required.
                  Because of trends in leasing farther offshore, the levels of activity adjacent to Louisiana parishes are not
              expected to be large as a result of this sale. This trend toward development farther offshore will result in
              greater dispersion of emissions, i.e., a very low level of impact.
                  Section 328 of the Clean Air Act (42 U.S.C. 7401-7642, as amended) directed the Department of the
              Interior to conduct a research study examining the impacts from activities on the OCS adjacent to Texas,
              Louisiana, Mississippi, and Alabama on areas that fail to meet the Federal air quality standards for ozone (40
              CFR 50). The MMS has been consulting with USEPA, the States, and others to design a study that will start
              in 1992. The study will have the following components: (a) a characterization of meteorological regimes
              associated with ozone episodes in nonattainment areas; (b) an evaluation of meteorological and air quality data
              from ozone modeling; (c) application of photochemical modeling to estimate impacts from OCS activities on
              ozone nonattainment areas; (d) a limited field program to collect meteorological data in offshore and coastal
              areas for future modeling applications; and (e) a set of recommendations for future monitoring and modeling
              activities.










                   IV-542

                       In addition to the air quality study being planned in the Gulf of Mexico, MMS and USEPA have been
                   consulting on the possibility of conducting a preliminary ozone study using the ROM model. A complete set
                   of results and impact assessment will be made when the 3-year study is completed. The EIS (Sections,
                   IV.D.I.a.(4) and IV.D.2.a.(4)) reflects MMS's needs and commitment to gather information on ozone formation
                   and dispersion from OCS emissions.
                       This EIS analysis (Section IV.A.2.d.(6)) indicates that offshore air emissions are not likely to cause
                   degradation of onshore air quality and are not likely to have any significant effect on nonattainment or
                   Prevention of Significant Deterioration Class I areas. Actual measures ordered by MMS will be determined
                   after reviewing additional site-specific studies submitted by lessees, along with thebr exploration and
                   development and production plans for approval.

                       Water Quality (Louisiana R S. 30:1068, 1091-1096; 38:216)

                       The Federal Water Pollution Control Act (FWPCA) (33 U.S.C. 1251 et. seq., as amended) vests exclusive
                   regulatory authority over discharges on the high seas to USEPA_ Under Section 307(f) of CZMA, the
                   applicable water pollution control requirements are those promulgated pursuant to the FWPCA. Inasmuch
                   as Louisiana does not have USEPA approval to administer NPDES permits for coastal waters pursuant to that
                   Act, USEPA!s own regulations are the applicable water pollution control requirement of the LCZMP.
                       All OCS exploratory operations involving discharges will be conducted in compliance with NPDES permits
                   (40 CFR 122) issued by the USEPA. Operational discharges (drilling muds and cuttings, produced waters, deck
                   drainage, and sanitary and domestic wastes) may degrade water quality somewhat, changing measures from
                   background levels, but with little effect to benthic and pelagic organisms in the water column, and then only
                   very close to the source. (No off-based drilling muds are allowed to be discharged into Federal waters.) The
                   MMS established a policy that requires the submission, for approval, of detailed plans for the disposal of all
                   produced solids accumulated as a result of OCS activities (LTL dated November 20, 1990). The impact to
                   marine waters from oil and gas discharge activities on these offshore leases is considered 1.0 be low.
                       The NCP requires that the U.S. Coast Guard's OSC obtain the concurrence of the USEPA representative
                   to the RRT and, as appropriate, the concurrence of the RRT representatives from the states having jurisdiction
                   over the navigable waters threatened by the release or discharge; and that, when practicable, the OSC consult
                   with the DOC and DOI natural resource trustees prior to authorizing the use of a chemical. agent Approved
                   chemical agents must be listed on the NCP Product Schedule. The OSC is not required to obtain the
                   aforementioned concurrence when, in the judgment of the OSC, the use of a chemical agent is necessary to
                   prevent or reduce substantially a hazard to human life. Consistent with this, a Memorandum of Understanding,
                   dated August 16, 1971, between the Department of the Interior and the Department of Transportation allows
                   MMS the authority to grant OCS operators approval to use chemical agents within a 5CO-in radius of the
                   source of pollution to abate the source of pollution only when such agents are deemed necessary as a measure
                   for the safety of personnel and operations.
                       Several activities may adversely affect marine water quality on the OCS and, thus, potentially the coastal
                   waters. Drilling operations, platform and pipeline installation, and platform removal operations may resuspend
                   bottom sediments. Some water quality parameters may change from background levels With little effect to the
                   benthic and pelagic life nearby, and then only very close to the source. The impact from these activities to
                   marine water quality above the OCS is considered to be low.
                       Existing onshore infrastructure and associated coastal activities in support of oil and gas activities on these
                   leases have the potential to contribute to a low extent to the degradation of regional coastal and nearshore
                   water quality. The barge trips and service-vessel trips expected to occur in Louisiana (Base Case) may further
                   impact water quality by routine release of bilge and ballast waters (estimated at 2,000 liters per day from
                   service vessels) and low-level antifouling paints. Each activity provides only a small measure of continuous
                   contamination. Discharge locations are widespread. Negligible saltwater intrusion could occur from
                   maintenance dredging or deepening of existing navigation channels for large vessel requirements. Such
                   dredging is likely to result in short-term, low-level impacts to the surrounding waters. All dredging would be
                   pursuant to COE permits (33 CFR 330) or conducted by the Corps itself, and would be subject to consistency
                   determination from that agency.










                                                                                                                            IV-543

                      No new service bases are expected to be constructed in Louisiana to support activities from Sale 143 leases.
                 Therefore, no additional point or nonpoint sources of pollution are likely to result. Environmental impacts
                 associated with normal service base use include runoff and spillage of fuels and chemicals from the facility,
                 discharges from supply and crew boats, channel bank erosion from vessel traffic, and disturbance of bottom
                 sediments from maintenance dredging. All new onshore facilities must be proposed in exploration or
                 development and production plans, which the State will review for consistency certification. Separate State
                 permits will also be necessary.
                      Accidental oil spills on the OCS may degrade water quality somewhat, changing measurements from
                 background levels, but with little effect to the pelagic and benthic organisms in the water column and then only
                 in a very limited area close to the source. Accidental oil spills may contribute to a local, low-level impact near
                 some terminals and service bases where the spills have a more probable occurrence; regionally, adverse impacts
                 from such accidental oil spills are assumed to be very low.
                      In both offshore and coastal areas, authorities cited above are sufficient to ensure that future operations
                 related to the proposed lease sale will not adversely affect water quality.

                 (2) Texas

                      The Sale 143 analysis area closest to the submerged lands of the State of Texas includes Western offshore
                 Subareas W-1, W-2, and W-3, which extend offshore from the State's 3-marine league line.
                      @ The Texas Legislature has distributed authority for coastal resource management among 14 State agencies
                 (Appendix III, Coastal Responsibilities of Texas State Agencies, Texas Coastal Management Plan, January
                 1991). Conflicts with local land use goals or planning are not expected to occur as a result of Sale 143, as
                 existing onshore infrastructure is expected to be sufficient.
                      The Texas Coastal Management Plan (TCMP) (State-approved plan) includes the following coastal
                 resource issues: coastal erosion/dune protection, beach access, wetlands loss and degradation, oil spills, marine
                 debris, freshwater inflow, nonpoint-source pollution, and hazardous waste generation and disposal.
                      Based on assumptions fully discussed in Sections IV.A_ and IV.C., the impacting factors generated by the
                 proposed sale are discussed below. These factors will affect coastal issues identified in the TCMP.

                 Coastal ErosionlDune Protection and Beach Access

                      No new support facilities, pipeline landfalls, or onshore pipeline projects are anticipated in Texas as the
                 result of activities on offshore leases (Base Case). Several deep-water pipelines will be constructed on
                 Matagorda Island along the Texas coast and towed into deep-water areas off Texas and Louisiana. No new
                 channels are expected to be dredged. One channel in the Corpus Christi area (coastal Subarea W-1) win be
                 deepened to 6.7 in (22 ft) to accommodate larger vessels. Transportation of equipment and materials to
                 support offshore operations is expected to use existing navigation channels through coastal areas (Brazos
                 Santiago Pass, Port Mansfield Cut, Matagorda Ship Channel, Yarborough Pass, Aransas Pass, Corpus Christi
                 Ship Channel, Freeport Harbor Channel, Houston/Texas City/Galveston Ship Channels, and Sabine Pass Ship
                 Channel). These operations would have only minor incremental effects relative to existing facilities. If any
                 hypothesized, postlease onshore development were to occur in Texas, it would be subject to control by
                 applicable State regulations. The Texas General Land Office is responsible for technical assistance and
                 compliance under the Dune Protection Act and for implementation of the Texas Coastal Preserve Program
                 with the Texas Parks and Wildlife Department The Texas Attorney General's Office protects the public's
                 beach access rights and can bring suit on behalf of other State agencies to enforce State laws.

                 Wetlands Loss and Degradation

                      Wetlands and submersed grassbeds are essential to the biological productivity of the Texas coastal zone.
                 Given the availability of existing harbor space, no new shoreline modifications are likely to be needed.
                 Additionally, no pipelines are proposed to cross Texas lands. If any new onshore facilities are proposed for










                  IV-544

                  development of offshore leases, potential effects to wetlands and submersed grassbeds in the State's coastal
                  zone will be subject to State regulatory review. The TCMP identifies the Texas Parks and Wildlife Department
                  as the State agency that would monitor and enforce a policy of no net loss of wetlands. The Texas Water
                  Commission and the General Land Office would also coordinate with them in this effort.
                      Coastal zone biological resources may be affected by oil spills associated with offiliore operations.
                  Prevention and containment and cleanup of oil spills are addressed through various Federal mitigation and
                  regulation measures (30 CFR 250.42). Such measures include MMS requirements for an oil-spill contingency
                  plan, prevention, and response; the platform verification program; and the general OCSLA. requirement to
                  apply the best available and safest technologies (BAST). The MMS requires that oil-spifl,mntingency plans
                  ensure that a full-response capability exists for containment in the event of an oil spill, including specification
                  of appropriate equipment and materials, their availability and deployment time, and provisions for varying
                  degrees of response effort, depending on the severity of the spill. The USEPA's development and
                  implementation of the National Oil and Hazardous Substances Pollution Contingency Plan (40 CFR 112) and
                  correlative regional plans are designed to provide a coordinated and integrated response byFederal and State
                  agencies to protect the environment from the damaging effects of accidental oil spills and pollution discharges.
                      Maintenance dredging in existing navigation channels in Texas could adversely affect wetlands if the
                  dredged material were disposed of in continuous spoil banks. The potential contribution of support activities
                  during exploration and/or production on these offshore leases, as compared with all navigation use of channels,
                  is likely to be very small and will be subject to later State regulatory review. The Texas Department of
                  Highways and Public Transportation is responsible for acquiring easements and rights-of-way from the General
                  Land Office for channel expansion, relocation, or alteration.

                  oil Spills

                      The primary factor of concern for sensitive coastal habitats is contact by accidental oil spills. An oil-spill
                  risk analysis, detailed information concerning oil spills and spill containmentand cleanup methods,are included
                  in Section IV.C. Predictive results of a computer model run for the EIS analysis assume that no efforts are
                  made to contain or clean up spills or otherwise protect sensitive resources from spill contact.
                      The mean number of spills over 1,000 bbl estimated to occur in the Western Gulf from proposed Sale 143
                  is 0.07. The EIS indicates that the sale could result in an approximate 0.05 percent probability of accidental
                  spills occurring and contacting the coast of Texas within 10 days.
                      An OSCP must be submitted for approval to MMS with, or prior to, an exploration or development plan
                  (30 CFR 250.33, 250.34, and 250.42). This OSCP, outlining the availability of spill containment and cleanup
                  equipment and trained personnel, is reviewed and updated annually. It must ensure that full-response
                  capability could be committed during an oil-spill emergency. This commitment would include specification for
                  appropriate equipment and materials, their availability, and the time needed for deployment. The plan must
                  also include provisions for varying degrees of response effort, depending on the severity of a spill.

                  Marine Debris


                      The State  of Texas Gulf coastal zone is one of the major recreational regions of the United States,
                  particularly in connection with marine fishing and beach-related activities. As indicated in Section IV.A.L,
                  onshore support is expected to be provided from existing facilities. Marine debris lost from OCS operations
                  associated with drilling and production throughout the 35-year life of the lease may occur from time to time,
                  but the effect of intermittent washup of debris on the recreational use of Texas beaches should be low. The
                  regulations at 30 CFR 250.40 require that offshore operators handle, control, mark, and dispose of containers,
                  equipment, and solid waste through stringent marking, equipment handling, and storage requirements. The
                  MMS inspectors check for compliance with regulations during daily offshore inspections. Failure to comply
                  with regulations leads to official warnings to take corrective action or, if warranted, to cease, operations.
                      Deliberate disposal of any solid waste or garbage items anywhere in the marine environment is strictly
                  prohibited under existing MMS, USEPA, and Coast Guard regulations. Because of increased concern with the
                  prevalence and effects of persistent marine debris both offshore and on coastal beaches, MMS issued a special











                                                                                                                             IV-545

                advisory (NTL 86-11) in 1986 strongly encouraging the oil and gas industry to take special educational,
                operational, and awareness measures designed to reduce or eliminate their contributions to marine debris in
                the Gulf of Mexico. Annex V of the International Convention for the Prevention of Pollution from Ships, also
                known as the MARPOL Protocol, prohibits the dumping of all plastic wastes, including plastic packaging
                materials and fishing gear, from all ships at sea. The MMS has established a policy that requires the
                submission, for approval, of detailed plans for the disposal of all produced solids accumulated as a result of
                OCS activities (LTL dated November 20, 1990).
                     From information collected at beach cleanups and during marine debris surveys, it has been estimated that
                existing offshore oil and gas operations are responsible for 10-15 percent of the trash and debris adversely
                affecting the Gulfs shorefront recreational beaches in the WPA- Recent Federal regulations (30 CFR 151)
                stemming from MARPOL Annex V, as well as periodic MMS directives and information seminars on the debris
                issue, should lead to better waste handling and less accidental loss of materials and personal items into the
                marine environment from offshore oil and gas operations. Additionally, industry education and training
                emphasis on waste management along, with voluntary stewardship commitments by several major oil companies
                (the adoption of about 30 mi of Louisiana Gulf beaches and the reduction and recycling of waste materials
                generated offshore), will also be reflected in a positive way on Texas' beaches.

                Freshwater Inflow, Nonpoint Source Pollution, and Hazardous Waste Generation and Disposal

                     Potable water will be needed for domestic uses of personnel living on offshore platforms. However, the
                EIS estimates that no new service bases are likely to be constructed. The quantity of freshwater needed for
                offshore operations on these leases is likely to be insignificant in an area such as coastal Texas. The Texas
                Water Commission has the responsibility of overseeing surface water rights.
                     The quality of nearshore and offshore waters is protected through standards and requirements for NPDES
                permits (40 CFR 122), as mandated in the Federal Water Pollution Control Act (33 U.S.C. 1251 et. seq., as
                amended). Marine water quality is protected through regulatory requirements, monitoring, and enforcement
                actions of MMS and USEPA. Discharges in coastal areas are also subject to regulation by the Texas Water
                Commission and Texas Water Development Board.
                     No onshore water quality degradation is likely to occur in Texas as a result of activities on offshore leases,
                because no new service bases are likely to be constructed in Texas (Base Case). Therefore, no additional point
                source and nonpoint sources of pollution are likely to result. In the unlikely event of any such occurrence,
                numerous Federal and State water pollution control regulations for mitigating any potential adverse effects
                exist.
                     Operational discharges (drilling muds and cuttings, produced waters, deck drainage, and sanitary and
                domestic wastes) may degrade water quality somewhat, changing measurements from background levels, but
                with little effect to benthic and pelagic organisms in the water column, and then only very close to the source.
                (No oil-based drilling muds are allowed to be discharged into Federal waters.) The impact to marine waters
                from oil and gas discharge activities on these offshore leases is considered to be low.
                     The NCP requires that the U.S. Coast Guard's OSC obtain the concurrence of the USEPA representative
                to the RRT and, as appropriate, the concurrence of the RRT representatives from the states having jurisdiction
                over the navigable waters threatened by the release or discharge; and that, when practicable, the OSC consult
                with the DOC and DOI natural resource trustees prior to authorizing the use of a chemical agent. Approved
                chemical agents must be listed on the NCP Product Schedule. The OSC is not required to obtain the
                aforementioned concurrence when, in the judgment of the OSC, the use of a chemical agent is necessary to
                prevent or reduce substantially a hazard to human life. Consistent with this, a Memorandum of Understanding,
                dated August 16, 1971, between the Department of the Interior and the Department of Transportation allows
                MMS the authority to grant OCS operators approval to use chemical agents within a 500-m radius of the
                source of pollution to abate the source of pollution only when such agents are deemed necessary as a measure
                for the safety of personnel and operations.
                     Several activities may adversely affect marine water quality on the OCS and, thus, potentially the coastal
                waters. Drilling operations, platform and pipeline installation, and platform removal operations may resuspend
                bottom sediments. Some measures of water quality parameters may change from background levels with little










                 IV-546

                 effect to the benthic and pelagic life nearby, and then only very close to the source. The impact from these
                 activities to marine water quality above the OCS is considered to be low.
                      Existing onshore infrastructure and associated coastal activities in support of oil and gas activities on these
                 leases have the potential to contribute to a low extent to the degradation of regional coastal and nearshore
                 water quality. Ile barge trips and service-vessel trips expected to occur in Texas (Base Cise) may further
                 impact water quality by the routine release of bilge and ballast waters (estimated at 2,000 liters per day from
                 service vessels) and low-level antifouling paints. Each activity provides only a small measure of continuous
                 contamination. Discharge locations are widespread. Negligible saltwater intrusion could occur from
                 maintenance dredging of existing navigation channels. Such dredging is likely to result in shoirt-term, low-level
                 impacts to the surrounding waters.
                      The MMS has established a policy that requires the submission, for approval, of detailed plans for the
                 disposal of all produced solids accumulated as a result of OCS activities (LTL dated November 20, 1990). The
                 USEPXs development and implementation of the National Oil and Hazardous Substances Pollution
                 Contingency Plan and correlative regional plans are designed to provide a coordinated and integrated response
                 by Federal and State agencies to protect the environment from the damaging effects of poUution discharges.
                 Deliberate disposal of any solid waste or garbage items anywhere in the marine environment is strictly
                 prohibited under existing MMS, USEPA, and Coast Guard regulations. The Texas Department of Health
                 regulates programs to protect and promote public health, including those addressing the issue of solid waste.
                 The Texas Water Commission regulates hazardous and industrial solid waste management.
                      In both offshore and coastal areas, authorities cited above are sufficient to ensure that ifuture operations
                 related to the proposed lease sales will not adversely affect water quality.

                 E. ANALYSIS OF A LARGE OIL SPILL

                      The MMS has evaluated the consequences of a large oil spill that could be associated with proposed Sales
                 142 and 143. Included here is an analysis of the potential effects of a hypothetical large spill that occurs under
                 unfavorable conditions. The analysis that follows assumes that a spill of 100,000 bbl occurs and contacts the
                 Gulf of Mexico shoreline. The spill occurs as a result of an accident involving a shuttle tanker transporting oil
                 produced as a result of either of the proposed actions. Although this section considers the impacts of a
                 100,000-bbl spill, the probability of occurrence of a spill of this magnitude resulting from the proposed actions
                 for Sales 142 and 143 is extremely low.

                 1. Background

                      As oil and gas exploration and production extends farther offshore into deeper water tracts, the use of
                 shuttle tankers to bring oil to shore for processing, rather than the installation of pipelines in deep water, may
                 occur. The EIS estimates that less than 1 percent of the oil produced under the Base Case lbr proposed Sale
                 142 and 19 percent of the oil produced under the Base Case for proposed Sale 143 will be transported by
                 shuttle tanker into Gulf Coast terminals.
                  . In the early stages of scenario development, the MMS Gulf of Mexico OCS Region considered different
                 cases of tanker, pipeline, and platform spills for several places along the coast and at all seasons of the year.
                 From these possibilities, the scenario that was selected for analysis here was a winter Spill at the entrance to
                 the Port Arthur ship channel.
                 2. Scenario to be Analyzed

                 a. Assumptions About the Occurrence of the Spill

                      It is assumed in this scenario that approximately 100,000 bbl of Louisiana crude oil are spilled within 24
                 hours during the winter from a shuttle tanker accident that occurs four miles from the coastline at the entrance










                                                                                                                           IV-547

                to the Port Arthur, Texas, ship channel. Average climatological conditions for this part of the Gulf are
                assumed at the time of the spilL Winds are blowing from the east at 11 kn, surface drift currents are moving
                west to northwest at 0.75 kn, and the surface water temperature is 610F. Severe storm conditions are not
                assumed because, historical1y, such conditions have dispersed spilled oil, and no surface slick remains after the
                passage of the storm. The spill. is assumed to occur in 33 ft of water. Tankers transporting crude oil produced
                as a result of proposed Sales 142 and 143 could be expected to move through this area enroute to terminals
                at Port Arthur, Texas.
                    The leading edge of the oil is assumed to rapidly wash ashore and contact the shoreline in approximately
                four hours. Offshore cleanup efforts are assumed to be ineffective at containing a significant amount of the
                spilled off, and dispersant use is not approved because of the proximity of the sensitive resources. Beach
                removal of off is assumed to be effective, and the majority of the oil wifl be cleaned from major recreational
                beaches after six weeks.


                b. Assumptions About the Offshore and Shoreline Zone of Contact

                    It is assumed that 10 percent of the spilled oil will not move directly to shore but will remain in the
                nearshore waters, moving with coastal current patterns. By the end of three days, the remaining oil slick is
                assumed to have been carried onto and along the coast by tidal and longshore currents. The off is assumed
                to be stranded along 80 mi of coastline from about nine miles west of the Sabine River in Jefferson County,
                Texas, to San Luis Pass at the south end of Galveston Island in Galveston County, Texas. The primary area
                of potential contact includes a 4 by 80 mi area offshore, the 80-mi stretch of shoreline, and on land, to the
                extent of the maximum inland movement of the off. Both the slick moving towards shore and the offshore slick
                would appear as a series of windrows. Oil slicks do not remain intact as discrete entities; therefore, it is
                assumed that they would be smeared or streaked over the primary area of contact.

                c. Assumptions About the Onshore Zone of Contact

                    With the exception of barrier passes at the entrance to Bolivar Roads and San Luis Pass at either end of
                Galveston Island, the entire stretch of coastline within the primary area is fronted by barrier island or chenier
                ridge beaches. The stranded oil would be deposited on the foreshore areas and lower berms of these beaches
                for a distance of 100 ft back from the normal low tide line. It is assumed that no stranded oil will move across
                barrier beaches into back barrier marshes. Any oil that reaches the passes between the two barrier islands,
                within the primary area of contact, is expected to be transported through these two barrier passes on incoming
                tides into the back barrier estuarine environment. It is assumed that 5 percent (1,750 bbl) of the oil that
                reaches the coast wiU be transported into Galveston Bay, and 1 percent (350 bbl) wil] be transported into San
                Luis Pass, based on the percentage of the shoreline that these passes occupy. In addition, it is assumed that
                50 bbI of oil wW be transported through Rollover Pass, a small breach in Bolivar Peninsula.
                    The oil that is transported into Galveston Bay is assumed to spread for six miles along the back sides of
                the barrier islands along either side of the barrier pass and for six miles along the mainland shore. The oil that
                is transported into San Luis Pass is assumed to spread for one mile on either side of the pass along the back
                side of the barrier. Discontinuous wetland areas occur in these settings. Twenty percent of the oil that is
                transported into the estuary is assumed to move 30 ft back onto these wetlands. Oil deposited in wetlands
                could accumulate in clumps of marsh vegetation or in protected pools or embayments, resulting in isolated thick
                layers of oil on such marsh surfaces and in sediments. The rest of the estuarine shoreline consists of bluffs cut
                into Pleistocene terraces, developed land, and scattered tidal flats. Here, oil will pile up along the shore or
                will coat the surface of tidal flats. The smaU amount of oil that is assumed to be transported through Rollover
                Pass wil] be deposited onto back barrier wetland areas within a few hundred yards on either side of the pass.
                    There is some smearing of the oil along the coast, or breakup and reemergence of the weathered oil
                farther up or down the coast over time. All of the oil that contacts recreational beaches is cleaned up to the
                extent that oil is not visible and that remnant oil will not interfere with the recreational use of the beach.
                Onshore efforts to contain or intercept the off as it reaches the shoreline are ineffective.










                 IV-548

                 d. Assumptions About the Fate of the Spilled Oil

                     Thirty-three percent of the oil would be lost from the slick surface as a result of weathering by four hours,
                 the time assumed for the leading edge of the oil to first contact land. About one-half of the a mount lost is due
                 to evaporation. In three days, it is assumed that the slick contains 35,000 bbl of oil with evaporation accounting
                 for 40 percent of the loss of slick volume. This assumption is based on conditions that allow the slick to spread
                 over a large surface area. By the end of 10 days, approximately 50 percent of the oil could be lost due to
                 evaporation and a total of 67 percent of the oil could have weathered from the slick surface.
                     Of the 10 percent of the spilled oil that remains offshore, 60 percent would be lost as a result of
                 weathering after 24 hours. The remaining offshore oil slick would cover less than one square mile of sea
                 surface by 24 hours.

                 3. Effects of a lArge Oil Spill

                     Resources assessed under the proposed actions are analyzed below with the exception of the sensitive
                 offshore habitats and communities category (Section IV.D.La.(2)). These resources will not be contacted by
                 oil spills because of their water depths.

                 a. Impacts on Sensitive Coastal Habitats

                 Coastal Baniers


                     The primary threat to a barrier landform from a large oil spill is the potential for the removal of large
                 quantities of sand in association with cleanup operations. The configuration of a barrier landform is
                 determined by the balance between the sand supply reaching the beach and the erosional processes that are
                 acting to remove the sand. On a sand-deficient beach, if the sand supply is depleted as a result of cleanup
                 operations, the beach could migrate and/or erode in adjustment to the new balance between erosional forces
                 and sand supply. Erosion and migration will cause loss of beach and island area and possible damage to fixed
                 structures on or near the beach (buildings, roads, power lines, etc.)
                     The length of coast that could be contacted by the spill includes accreting and eroding segments. The
                 Galveston Island shore face is a stable or accreting segment. Cleanup efforts along the Galveston Island
                 shoreline would not have a large impact on beach and island morphology. After the tankerAlvenus spill (about
                 67,000 bbl of oil), for example, 90,000 yd3 of sand were removed from the beaches along middle and western
                 Galveston Island. This amount of sand removal was considered equivalent to the amount that would be
                 removed by a minor storm. By comparison, Hurricane Alicia, a major Gulf hurricane, removed 900,000 yd3
                 of sand from Galveston beach. As a result of the cleanup and the associated sand removal, the beach profile
                 changed slightly, but this change was undetectable after a few spring tides.
                     Along the remaining sections of the coast that could be contacted by the spill, beaches are undergoing
                 varying rates of erosion. Removal of sand from these areas as a result of cleanup operations could alter the
                 cross-sectional and plan configurations of the coastline as a result of beach adjustments to a lowered sand
                 supply. Techniques that do not remove large quantities of sand could be used to clean the beach. These
                 cleanup approaches would probably be more expensive than simply scraping the oiled sand off the beach, but
                 they would result in reduced impacts to the beach.
                     Impacts to coastal barriers as a result of contact from the large spill would be short-term changes in beach
                 profile where sand had been scraped away and not replaced during cleanup operations. No long-term impacts
                 will occur at Galveston Island. Elsewhere, some accelerated erosion of the barrier shoreline may occur where
                 large quantities of sand were removed from the beach and not replaced. The use of cleanup methods that do
                 not remove sand from the beach will lower erosional impacts.











                                                                                                                             IV-549


                Wetlands


                    Along the coastal area affected by the spill, wetlands occur either in back barrier estuarine settings
                (Galveston County) or directly behind mainland barrier beaches (Jefferson and Chambers Counties). The
                continuous length of barrier beach along the coast in Jefferson and Chambers Counties will prevent the spilled
                oil that is moved onto the beach from being deposited in the wetlands. In Galveston County, oil will be
                transported through barrier passes at Bolivar Roads (the entrance to Galveston harbor) and at San Luis Pass
                at the southern end of Galveston Island. There is also a small cut through Bolivar Peninsula that win allow
                a small quantity of oil to move into the estuary. The total amount of oil that will be transported onto wetland
                areas through these three passes is approximately 2,150 bbl. About five miles of marsh shoreline will be
                contacted by the off. If this oil were spread evenly over the contacted marsh area, the concentration of oil on
                the marsh surface will be approximately 0.017 gallons/square foot. This concentration is below the amount
                (0.35 gallons/square foot) that was shown to have a detrimental effect on the vigor and survival of Spartina
                alterniflora vegetation in Galveston Bay, Texas, when varying concentrations of oil were applied to the marsh
                (Alexander and Webb, 1985).
                    Although it is likely that the oil will be spread across a large expanse of wetlands with the tides, this
                spreading will not be completely uniform. Lower elevation and protected wetland areas will likely accumulate
                greater concentrations of oil. Alexander and Webb (1987) have reported that areas of a Spanina alterniflora
                marsh, which had become heavily oiled (5-50 parts of oil per 1,000 parts of marsh soil) after a spill in Galveston
                Bay, showed significantly reduced growth for 18 months after the spill. Accelerated erosion of marsh shorelines
                that had received heavy oiling was apparent by 16 months and continued through 32 months. Other areas that
                had received lighter concentrations of oil were not affected by the spill.
                    The results of the 1987 Alexander and Webb study provide a realistic scenario for assessing impacts from
                the occurrence of the very large off spill in the WPA. Investigations that use Spartina alterniflora as the test
                species are useful for the analysis of the impacts of the spill being considered because this grass dominates the
                vegetation of saline marshes, which will characterize much of the coastal fringe 30 ft back from the shoreline.
                Furthermore, the Alexander and Webb spill occurred in the same coastal region of Texas and involved a spill
                with dimensions of the same order of magnitude as the one being considered (160 bbl spilled along four miles
                of coast).
                    Based on the results of this study, most of the wetland areas contacted by the spill will be unaffected by
                the oil because the oil on the marsh will have been spread out to a low concentration. Some areas, probably
                close to the shore, will receive heavier concentrations of oil, resulting in reduced plant vigor and dieback during
                the following two growing seasons and in accelerated marsh shoreline erosion because of the greater
                susceptibility of the shoreline to wave attack after the marsh grass roots have died.
                    The affects of the spilled oil on coastal wetlands are expected to persist for 1-3 years, except in areas where
                the marsh shoreline has eroded. In these cases, the loss of wetland areas will be permanent. However, only
                a small percentage of the total wetland acreage in an area contacted by the large spill will be destroyed or
                altered as a result of the spill.

                b. Impacts on Water Quality

                    The effect of oil spills on water quality is determined by the amount of oil that resides within the contacted
                water body. Significant degradation of offshore water quality is directly proportional to the areal coverage of
                the surface slick, the concentration of oil transported into the water column, and the residence time of the oil
                in the water column. The slick itself, defined as the oil spread on the water surface, is a short-lived phenomena
                and is only important in determining water quality impacts because of its contribution of hydrocarbons into the
                water column. The concentration of oil in the surface slick of the 100,000-bbl spill averages 0.0024
                gallons/square foot of surface water (NRC, 1985) by the third day of the spill incident.
                    Major weathering processes removing oil from the surface of the water include spreading, evaporation,
                dissolution, dispersion (often called vertical transport), photochemical oxidation, adsorption to suspended
                particulate matter, and microbial degradation. Section IV.C.2. describes these processes in more detail. Oil
                spilled from a subsurface source, such as the tanker spill being considered here, will form a subsurface plume.
                This plume, although poorly understood, is assumed to rapidly rise to the sea surface to form a surface slick










                 IV-550

                 that moves with the currents and winds. Spilled oil can be mixed into the water column primarily through three
                 mechanisms. First oil in the surface slick can be dispersed back into the water due to wave, action. Second,
                 dissolution of the lower molecular weight hydrocarbons would occur from the surface slick and subsurface
                 plume. Dissolution does not play a significant role in the mixing of oil into the water column, usually resulting
                 in less than a 1 percent loss from the total slick hydrocarbon concentration. Third, turbulence in the water,
                 caused by the rapidly rising subsurface plume, would result in the greatest dispersion of water droplets into the
                 surrounding water column during the spill incident.
                     Such weathering processes, which remove off      from the water surface, would be slowed during winter
                 because the processes are temperature dependent. During winter, the average coastal water surface
                 temperature is 610F.

                 Offshore

                     The oil spill is assumed to occur from a grounded tanker, four miles from the coastline near the entrance
                 to the Port Arthur ship channel. It is assumed that the oil is released from the bottom of the grounded
                 tanker's hull. Oil spilled at the seafloor would form a subsurface plume that rapidly rises to the sea surface
                 to form surface slicks. Two primary slicks are assumed to be formed at the surface of the water over the
                 discharge site. The majority of the floating oil is assumed to be pushed directly toward land. This primary slick
                 becomes stranded along the shoreline within the surf zone in the first three days following the accident.
                 Because of shifting winds, however, it is not expected that all of the oil would move directly toward the
                 shoreline. Ten percent of the oil would move as a separate discreet slick, moving westward within nearshore
                 waters.
                     As described above, oil would become incorporated into the water column in two ways: (1) at the
                 subsurface discharge point, due to turbulence from the rising oil and (2) under the floating surface slicks, due
                 to dispersion and dissolution processes. Concentrations of hydrocarbons in the water column surrounding the
                 discharge point decrease with distance away from the spill, and will likely decrease tenfold seven miles on either
                 side of the plume (USDOI, MMS, 1987e). It is assumed that the majority of the oil dispersed into the water
                 column would occupy the top 20 ft of the water column similar to conditions recorded during the Lr1oc spill
                 (Fiest and Boehm, 1980). Therefore, the major volume of water affected by the primary slick moving landward
                 would be 4 mi (distance from shore) by 14 mi (7 mi on each side of the plume) by 20 ft (water depth affected).
                     The surface slick, formed from the 10 percent of the oil remaining offshore, would persist for
                 approximately 4.5 days before disappearing from the water surface due to weathering processes. It would cover
                 a maximum area of I mi2 before breaking up. The volume of water affected by this slick would be I mi2 by
                 20 ft.
                     Calculations of the maximum amount of oil within the water column were then made for the affected areas.
                 Approximately 9,000 bbl of oil would be contained in the water column after three days under the major
                 surface slick heading towards shore, and about 2,600 bbl of oil would be contained under the offshore slick
                 after four days. Given all of the above, maximum hydrocarbon loadings of the affected waters would be 30,000
                 ppb. This figure is very high when compared to the average reported concentrations of oil in pristine waters
                 of less than I ppb (Fiest and Boehm, 1980).
                     It is assumed that the contaminated water would mix with surrounding water and would become diluted.
                 After several weeks, enough mixing would take place so that, within the primary area of contact, hydrocarbon
                 quantities would approach background levels.
                     In conclusion, hydrocarbon concentrations would increase in the primary area of contact by several orders
                 of magnitude. This condition would persist for days to weeks. Effects on regional water quality conditions
                 would not be considered significant due to the relatively small areal extent of impact.

                 Coastal and Nearshore


                     It is assumed that the slick will spread out along the shore, contacting 80 mi of west Te,,ms chenier ridge
                 beaches and barrier islands by the end of three days. Nearshore coastal water quality adjacent to the
                 contaminated 80 mi would be affected by the oil due to backwashing of the oil into the surf zone. Oil returning










                                                                                                                           IV-551

               to the surf would likely be trapped by longshore currents and, therefore, would remain within nearshore waters.
               Surf conditions would accelerate the amount of hydrocarbons dispersed into the shallow water column.
               Therefore, in nearshore waters contacting the beaches, it is expected that hydrocarbon concentrations would
               be significantly higher than background levels. Waters containing significantly higher levels of hydrocarbons
               than background levels are assumed to be contaminated and of poor water quality. This contamination would
               continue until the source of the contamination, the oil on the beaches, is removed. Cleanup of beaches is
               assumed to be completed in about six weeks. Prior to this time, it is assumed that the longshore currents would
               continually be carrying some contaminated water westward beyond the primary area of contact. The
               contaminated water that remains after the beaches are cleaned would mix with surroundingwater as it moves
               westward with nearshore currents and become diluted to background levels within several weeks. It is therefore
               expected that the 100,000-bbl spill would significantly alter the water quality of Texas nearshore waters for
               several weeks.
                   It is assumed that 2,100 bbl of the oil would reach the back bay area behind Galveston Island through the
               Bolivar Roads and San Luis Pass inlets. Another 50 bbl of oil would enter the back barrier area through the
               Rollover inlet, a small channel through Bolivar Peninsula. Of the 2,150 bbl of oil that enter the inland coastal
               waters, 430 bbl are assumed to reach coastal wetlands along a total of five miles of bay shoreline. The oil win
               move back 30 ft into wetland waters. The majority of the oil covering wetlands would weather, and quantities
               of hydrocarbons would likely return to background levels within several months after the spill occurred. The
               colder weather occurring in the winter would impede weathering processes so that the oil may remain above
               ambient conditions until warmer weather returns. Some of the oil, however, could be pushed into clumps of
               marsh vegetation or into protected pools or embayments, resulting in a thick layer of oil on these water bodies
               or marsh surfaces. Dissipating factors reducing the concentrations of oil would operate slower due to the low
               energy of the isolated water bodies, due to the thickness of the oil on the marsh surface, and due to the cold
               weather. These isolated pools of oft would weather more slowly and may release oil into the surroundingwater
               bodies for a much longer time period. Past studies (discussed in Section IV.D.1.a.(1)(b)) documented that this
               type of dense oiling has occurred, releasing oil from oiled sediments and vegetation for over one year from the
               time of the spill. Given the above, a large spill entering the inland estuarine environment of Galveston Bay
               would result in impacts in a few, scattered wetland and pond areas because of thick accumulations of off. It
               is expected that the remaining bay environment, based on this scenario, would also experience impacts.

               c. Impacts on Air Quality

                   Evaporation of total hydrocarbons from the large oil spill results in emissions into the atmosphere of the
               Port Arthur and Galveston area. These emissions would discharge a number of volatile organic compounds
               (VOC), which are a constituent in the formation of photochemical oxidants (0.), in particular ozone.
                   Emissions of hydrocarbons and VOC would occur at a variable rate. The greatest rate of evaporation
               would occur during the first hour and would decrease continuously afterwards. It is assumed that 17 percent
               of the original spilled oil would evaporate during the first four hours, 40 percent (23 percent more) by the third
               day, 42 percent in five days, and 50 percent by the 10th day.
                   The duration and magnitude of the concentrations depend on air and water temperature, wind speed and
               direction, and the amount of sun irradiance occurring during the spill. The spill scenario assumes an easterly
               wind with a mean speed of 3 ms-1 and water temperature of 160C, which represent seasonal average wind and
               sea surface conditions for the area. Heat flux peaks during this time, which is indicative of strong vertical
               mixing.
                   By the end of the first 4 hours, a total of 2,499 tons would have evaporated into the atmosphere. This
               estimate was calculated by expressing the amount of spilled crude oil in tons and multiplying by the preceding
               evaporation rates. By the third day, evaporated oil would amount to 5,879 tons, and by the end of the tenth
               day, approximately 7,349 tons. During winter, potentially very stable atmospheric and low mixing heights
               conditions can occur, causing high short-term (24 hours) air quality impacts in localized areas. The addition
               of these emissions under normal climatic conditions could increase ozone levels in the coastal environment.










                  IV-552

                  However, long-term impacts of the large crude oil spill on the coastal air quality will be lower because the
                  increase of pollutants represents about 21 tons a year of hydrocarbons.

                  d. Impacts on Endangered and Threatened Species

                      The following threatened and endangered species and their habitats between San Luis Pass and Sea Rim
                  State Park, Texas, could be impacted by a 100,000-bbl spill or its subsequent containment/cleanup operations
                  because they are located within the area of potential impact: piping plover, eskimo curlew, bald eagle, Arctic
                  peregrine falcon, brown pelican, and the Kemp's ridley, green, loggerhead, and hawksbill turtles. If these
                  animals or their habitat were contacted by spilled oil or were in proximity to the resultant con tainment/cleanup
                  operations, the impacts could include mortality or displacement of food, displacement from. critical habitats,
                  mortality or disfunction from ingestion or contact, reduced reproductive capacity, and debilitating or terminal
                  stress. These impacts could be acute as well as long term and could impact all life stages from prenatal to
                  adult. Protected species, which occur in or on the Gulf Coast but do not inhabit areas that occur in the area
                  of potential impact, include the jaguarundi, ocelot, Mississippi sandhill crane, Alabama beach mouse,
                  Choctawatchee beach mouse, and Perdido Key beach mouse, whooping crane, leatherback sea turtle, and the
                  great whales (blue, sei, right, fin, and sperm). The marine species occur farther offshore than the spill will
                  contact, and the terrestrial species occur inland of the landward extent of the spill.

                  Piping Plover

                      The piping plover migrates to and congregates along the sandy shores of the central and western Gulf
                  Coast during the winter. Based on the scenario, the spill and cleanup/containment operations would contact
                  piping plover habitat in Bolivar Flats and San Luis Pass, Texas. The spill, occurring during the winter, could
                  contact the piping plover and its habitat because the bird's primary congregating, feeding, resting, and roosting
                  areas are within the area of impact (i.e., 10 m of the mean low tide on Gulf Coast sandy shores). Impacts to
                  the birds from such a contact are discussed in the first paragraph of this section. A significant portion of the
                  population is assumed to be in the area of impact because the fourth largest piping plover ag regation, which
                                                                                                                   19
                  was observed in a 1987-1988 survey, was located at Bolivar Flats, with a smaller aggregation at San Luis Pass.
                  It is likely that a portion of the local population could die or be reproductively disabled as a result of contact;
                  such mortality has been documented. A local population decline could occur, and this decline would take more
                  than three generations to recover. Such losses would eliminate the piping plover from ul to 80 mi of its
                                                                                                                   P
                  wintering range and could reduce the gene pool of the species to a point that could impair its ability to recover.

                  Arctic Peregrine Falcon

                      The Arctic peregrine falcon migrates through and concentrates along the coast of the western and central
                  Gulf of Mexico during the spring, fall, and winter. The greatest threat to peregrine falcons from the spin is
                  the external oiling and toxic ingestion of oil during and after the capture of oiled prey. Based on the scenario,
                  the spill and cleanup/containment operations would contact Arctic peregrine habitat in coastal Texas between
                  San Luis Pass and Sea Rim State Park. A spill occurring during the winter could contact Arctic peregrine
                  falcons and their habitat because the birds' primary feeding areas are within the area of impact (i.e., 10 m of
                  the mean low tide on the central and western Gulf Coast). Impacts to the birds from such a contact are
                  discussed in the first paragraph of this section. A significant portion of the population may be in the area of
                  impact because the North American Arctic peregrine population concentrates in a coastal corridor from
                  Louisiana through Mexico during its spring, fall, and winter migration. A significant portion of the species or
                  its habitat may come in contact with oil or cleanup/containment operations because the peregrine's prey inhabit
                  the area of potential impact. It is likely that a significant portion of the population could be reproductively
                  disabled with some mortalities as a result of contact; such mortality has been documented. A population
                  decline could occur and this decline could take more than three generations to recover. Such losses would be
                  acute, as in the case of birds starving because of their inability to fly after being oiled, or long term, where oil
                  ingestion results in infertile or thin-shelled eggs.











                                                                                                                           IV-553


               Brown Pelican


                   The brown pelican is protected in Louisiana and Texas because of population declines in these states. The
               protected population nests in lower Laguna Madre, Corpus Christi Bay, and Aransas Bay in Texas, and
               Barataria Bay and Mississippi Sound in Louisiana. The majority of the species occurs in a healthy, unprotected
               population along the Gulf Coast of Florida. Based on the scenario, the spill and cleanup/containment
               operations could contact brown pelicans and their habitat in Galveston Bay. The spill, occurring during the
               winter, could contact the brown pelican and its habitat because the bird's primary congregating, feeding, resting,
               and roosting areas are in the area of impact (Le., in coastal waters or within 10 m of the mean low tide).
               Impacts to the birds from such a contact are discussed in the first paragraph of this section. A significant
               portion of the protected brown pelican population is not assumed to be in the area of impact because no
               nesting rookeries exist in the Galveston Bay area. A significant portion of the protected population or its
               habitat will therefore not come in contact with oil or cleanup/containment operations. However, that portion
               of the population that occurs in the Galveston Bay area is at risk because the bird's primary habitat is within
               the area of potential impact. The portion of the population in Galveston Bay could die or become
               reproductively disabled as a result of contact; such mortality has been documented. A local population decline
               could occur and this decline could take one generation to recover.

               Bald Eagle

                    The bald eagle is endangered throughout most of the Nation. They occur throughout the continental
               United States and Alaska including the Gulf of Mexico coast. They build nests near water and hatch eggs from
               November to April. Eagles feed primarily on fish, shorebirds and waterfowl, of ten preferring carrion over
               predation. Based on the scenario, the spill and cleanup/containment operations could contact bald eagle
               habitat between Sea Rim State Park and San Luis Pass, Texas. The spill, occurring during the winter, could
               contact the bald eagle and its habitat because the bird's primary feeding areas are in the area of impact (Le.,
               in coastal waters or 10 in of the mean low tide). Impacts to the birds from such a contact are discussed in the
               first paragraph of this section. A significant portion of the local population will not be in the area of impact
               because no nests are reported for the area of primary impact. A significant portion of the species or its habitat
               will not come in contact with oil or cleanup/containment operations because of the small number of eagles in
               the area of potential impact. A small portion of the population could die or be reproductively disabled as a
               result of contact; such mortality has been documented. Birds from the interior would recolonize coastal areas
               within a generation if coastal birds were extirpated by a spill. Such losses would be acute, as in the case of a
               birds starving because of their inability to fly after being oiled, or long term, where oil ingestion results in
               infertile or thin-shelled eggs.

               Sea nrtles


                   Five species of sea turtles occur in the northern Gulf of Mexico. The loggerhead and Kemp's ridley sea
               turtles are the only species that nest in the central and western Gulf of Mexico. For the purposes of discussion,
               this analysis will concentrate on these two species because more is known about their distribution and
               abundance in the Gulf of Mexico. Based on the scenario, the spill and cleanup/containment operations would
               contact sea turtle habitat between Sea Rim State Park and San Luis Pass, Texas. The spill, occurring during
               the winter, could contact sea turtles and their habitat because their primary feeding areas are in the area of
               impact (i.e., in coastal waters and on land within 10 in of the mean low tide). Impacts to the turtles from such
               a contact are discussed in the first paragraph of this section. Although little is known about the distribution
               and abundance of sea turtles, for the sake of analysis this discussion assumes that a significant portion of the
               sea turtle populations do not occur in the area of impact because so few sightings have been reported in the
               area. The exception is the Kemp's ridley turtle, which periodically strands in large numbers along this portion
               of the coast Although mortality from contact and ingestion of oil has been documented, a significant portion
               of the population will not be affected, except in the case of the Kemp's ridley. A population decline could
               occur and this decline could take one generation to recover for loggerhead, hawksbill, and green turtles. The










                  IV-554

                  Kemp's ridley could sustain a population decline as large as 5 percent, which could last as long as two to three
                  generations.

                  e. Impacts on Marine Mammals

                       More than twenty species of nonendangered marine mammals occur in the northern Gulf of Mexico. Eight
                  species have been observed with regularity, the bottlenose dolphin being the most common. The bottlenose
                  dolphin is the only species that would be contacted by the spill because they occur nearshore within the primary
                  area of potential contact in the spill scenario. All other species will not contact or be impacted by the spill or
                  its cleanup operations because they occur outside the primary area of impact. Contact with bottlenose dolphins
                  will result in dysfunction as a result of skin irritation, displacement from preferred habitats, ingestion, and loss
                  of food sources. The impact on dolphins would be greatest in those populations that have high accumulations
                  of toxic metabolites and during periods of poor water quality (i.e., red tide).

                  f. Impacts on Coastal and Marine Birds

                       The back barrier estuarine environment, barrier islands, beaches, and nearshore waters of Chambers,
                  Jefferson, and Galveston Counties in Texas are populated by both migrant and resident species of waterfowl,
                  wading birds, and shorebirds. Refer to Section IV.D.La.(7) for a detailed discussion of the effects of oil on
                  coastal and marine birds.
                       A very large spill 4 mi off Port Arthur, Texas, will contact barrier islands and beaches on the Texas coast
                  Most of the off (90 percent) will come ashore. The oil will wash ashore 100 ft back from the normal low tide
                  line. Approximately 1,750 bbl of the oil will be transported through Bolivar Roads Pass into Galveston Bay
                  and the back barrier estuarine environment, spreading six miles across from and six miles both east and west
                  of the Pass. Approximately 50 bbl of the oil will be transported through Rollover Pass into the back barrier
                  estuarine environment, spreading a few hundred feet across from and a few hundred feet both east and west
                  of the Pass. Approximately 350 bbl of the oil will be transported through San Luis Pass into Redfish Cove and
                  the back barrier estuarine environment, spreading one mile across from and one mile both east and west of
                  the Pass.
                       The majority of the waterfowl population (e.g., ducks and geese) are overwintering migrants. The
                  occurrence of a very large spill during the winter would contact those duck species of the ixntral flyway that
                  migrate to the back barrier estuarine environment, barrier islands, beaches, and nearshore waters found in
                  Chambers, Jefferson, and Galveston Counties. These ducks (e.g., lesser scaup, mergansers, and fulvous
                  whistlers) are gregarious and feed on marine fish and shellfish while in coastal areas.
                       Wading birds (e.g., herons, egrets, and ibis) are both overwintering migrants and residents of the Texas
                  coast and would be vulnerable to contact from a large spill. Major wading bird habitats include the protected
                  bays, back barrier estuarine environment, barrier islands, and open beaches found in Chambers, Jefferson, and
                  Galveston Counties. Under the spill scenario, wading birds that occupy the foreshore area of the islands and
                  the oiled areas of the back barrier estuarine environment near the barrier passes would be contacted by oil.
                       Shorebirds (e.g., gulls, terns, sandpipers, and shearwaters) are both overwintering migrants and residents
                  of the Texas coast and would be vulnerable to contact from a large spill. Shorebirds are closely associated with
                  the marine environment. Major shorebird habitats include the back barrier estuarine environment, barrier
                  islands, open beaches, and nearshore waters found in Chambers, Jefferson, and Galveston. Counties. Under
                  the spill scenario, birds roosting in the nearshore part of the primary area of potential contact (80 mi along
                  the coast by 4 mi offshore) would be contacted by oil. In addition, shorebirds that occupy the foreshore area
                  of the islands and the oiled areas of the back barrier estuarine environment near the barrier passes would be
                  contacted by off. Shorebirds nest on the barrier islands of Chambers, Jefferson, and Galveston Counties,
                  between the dunes and the normal low tide line. Under the spill scenario, these nesting sites would be
                  contacted and contaminated by oil. However, beach cleanup operations would be completed within six weeks
                  of the spill before shorebird nesting activities take place on these beaches in the spring. Therefore, it is
                  expected that shorebird nesting sites would not be impacted from a large oil spill.











                                                                                                                             IV-555

                     It is expected that contact between the spilled oil and birds associated with the coastal area in the settings
                 described above would result in both lethal and sublethal impacts on the contacted birds. It is expected that
                 no more than 1,000 birds associated with the coastal area will be contacted by the spilled off. Direct contact
                 between partially weathered oil and adult birds would result in lethal impacts, whether or not the birds were
                 completely oiled, due to ingestion and toxic poisoning, drowning, or hypotherinia. Direct contact between
                 heavily weathered oil and adult birds would result in sublethal impacts including decreased survival and
                 fecundity and modifications of normal behavior. Any oil remaining in the protected bays and back barrier
                 estuarine environments found in Chambers, Jefferson, and Galveston Counties would exist as probable
                 contaminated areas or sources of contaminated food for several months. Adults of both resident and migrant
                 birds associated with the coastal area would be susceptible to sublethal impacts from feeding in these
                 contaminated areas or on contaminated food. Within the limited geographical area affected, both migrant and
                 resident coastal bird populations would decline and change their distribution and/or abundance for one to two
                 generations or for two to three years.

                 g. Impacts on Commercial Fisheries

                     Commercial fisheries in the Gulf of Mexico are dominated by estuarine-dependent species. The back
                 barrier estuarine environment, nearshore waters, and passes of Chambers, Jefferson, and Galveston Counties
                 in Texas serve as nursery grounds and immigration routes for eggs, larvae, and/or juveniles of commercial
                 finfish and shellfish that are spawned offshore. Refer to Section IV.D.l.a.(9) for a detailed discussion of the
                 effects of oil on finfish and shellfish.
                     A very large spill 4 mi off Port Arthur, Texas, will contact barrier islands and beaches on the Texas coast.
                 Most of the oil (90%) will come ashore. The oil will wash ashore 100 ft back from the normal low tide line.
                 Approximately 1,750 bbl of the oil will be transported through Bolivar Roads Pass into Galveston Bay and the
                 back barrier estuarine environment, spreading 6 mi across from and 6 mi both east and west of the Pass.
                 Approximately 50 bbl of the off will be transported through Rollover Pass into the back barrier estuarine
                 environment, spreading a few hundred feet across from and a few hundred feet both east and west of the Pass.
                 Approximately 350 bbl of the oil will be transported through San Luis Pass into Redfish Cove and the back
                 barrier estuarine environment, spreading one mile across from and one mile both east and west of the Pass.
                     Important commercial fisheries species in Chambers, Jefferson, and Galveston Counties that could be
                 contacted by a very large off spill include brown shrimp, blue crab, American oyster, flounder, and several
                 species of sciaenids. All stages of larval shrimp are distributed within the upper portion of the water column
                 while nearshore. Postlarval shrimp become benthic after entering nursery grounds. Young blue crabs are
                 distributed within the upper portion of the water column while nearshore. Blue crabs become benthic after
                 entering nursery grounds, but retain the ability to swim for short distances especially with tidal currents. Oyster
                 larvae remain within back barrier environments and once settled as adults do not change location. Except for
                 flounder, young finfish are distributed within the upper portion of the water column while nearshore. Juvenile
                 finfish remain pelagic in back barrier estuarine environments, but occupy shallow water areas along with young
                 flounder.
                     The greatest potential for damage to commercial fisheries would occur when oil contacts nearshore waters
                 and back barrier estuarine environments during the time when high concentrations of planktonic larvae, or
                 developing young, are present. Young finfish and shellfish (e.g., shrimp, blue crabs, and sciaenids) would be
                 vulnerable to contact from a very large spill. Under the spill scenario, young finfish and shellfish would be
                 contacted by oil as they migrate from nearshore waters through the primary area of potential contact (80 mi
                 along the coast by 4 mi offshore) into back barrier estuarine environments found in Chambers, Jefferson, and
                 Galveston Counties. Under the spill scenario, all life stages of oysters that occupy the oiled areas of the back
                 barrier estuarine environment near the passes would be contacted by oil.
                     It is expected that contact between the spilled oil and important commercial fish and shellfish species in
                 the settings described above would result in both lethal and sublethal impacts on the contacted species. Direct
                 contact between partially weathered oil and the eggs, larvae, or juvenile stages of finfish or shellfish would
                 result in lethal impacts, due to ingestion and toxic poisoning and/or uptake of dissolved oil through the










                 IV-556

                 epithelium or gills and toxic poisoning. Direct contact between heavily weathered off and juvenile fish and
                 shellfish would result in sublethal impacts including decreased resistance to disease and reduced growth rates.
                 Any off remaining in the protected bays and back barrier estuarine environments found in Chambers, Jefferson,
                 and Galveston Counties would exist as probable contaminated areas or sources of contaminated food for
                 several months. Juvenile firifish and shellfish would be susceptible to sublethal impacts frorn feeding in these
                 contaminated areas or on contaminated food. In addition, low concentrations of the spilled oil could taint the
                 flesh of adult oysters rendering them unmarketable.
                      Fishermen tend to fish within a limited, traditional area. This area may be only hours from their home
                 port. Fishermen are reluctant and often unable to switch gear type or to change target species. Within the
                 limited geographical area affected, commercial fisheries would be depressed with local fishermen out of work
                 and secondary employment affected for one to two years after the spill.

                 h. Impacts on Recreational Resources and Activities

                     A large oil spill affecting up to 80 mi of north Texas coastline between the Sabine Riverand San Luis Pass
                 would have short-term adverse impacts on several designated park areas and general-use beach areas,
                 extending the entire length between Sabine Pass and Galveston Island. Sea Rim State Park, a 5.2-mi stretch
                 of designated beach park in Jefferson County, would likely receive the initial oiling from an assumed spill off
                 Port Arthur. About 5-10 percent of annual visitations occur during the winter season and consist mainly of
                 recreational vehicle campers traveling the Gulf Coast. The attention associated with a major winter spill could
                 even attract more winter leisure travelers to the park than normal. Within the next two days, intermittent oiling
                 of the extensive dispersed use recreational beaches fronting on Jefferson and Chambers Counties would be
                 adversely affected also. By the third day, the 9 mi of Gulf recreational beaches associated with the City of
                 Galveston Island, Galveston Island State Park's 1.5 mi of beachfront, and Seawolf Park are likely to be
                 impacted by residual oil from an assumed spill off the Port Arthur ship channel. Although beach use,
                 particularly swimming and sunbathing, declines appreciably after Labor Day, residual use of coastal beach
                 parks, pier, jetty, and surf fishing continues through the fall and winter months, especially in Galveston County.
                 Very little recreation activity is focused on beach activities in Galveston County during the winter months, but
                 publicity associated with a very large spill event, which pollutes the city's major natural recreational amenity,
                 is likely to result in some cancellations of discretionary leisure travel planned to the city of Galveston and may
                 discourage attendance at Sea Wolf Park.
                     In general, the socioeconomic impact of a large oil spill on beach communities is unlikely to be severe
                 during the off season but would preclude or detract from public use and enjoyment of directly impacted
                 beaches for several days on up to six weeks, depending on current, tides, weather, aarss, and cleanup
                 effectiveness. Cleanup of beaches extensively affected by crude oil is labor intensive and can result in beach
                 closures and sand displacement, removal, and disposal problems. As noted from the large spills and accidents
                 that have impacted major Gulf of Mexico beaches with oil in the past, recreational use and enjoyment of
                 coastal beaches and shoreline fishing platforms return to normal after evidence of the spill was gone.


















   SECTION V

   CONSULTATION AND
   COORDINATION                  v











                                                                                                                              V-3
                V. CONSULTATION AND, COORDINATION

                A. DEVELOPMENT OF THE PROPOSED ACTIONS

                    The draft 5-Year OCS Oil and Gas Leasing Program Schedule for 1992 to 1997 (tentatively scheduled for
                completion in mid 1992) authorizes proposed lease Sale 142 covering the Central Gulf of Mexico, to be held
                in March 1993, and proposed lease Sale 143 covering the Western Gulf of Mexico, to be held in August 1993.
                     The Area Identification process was initiated on June 13, 1991, with the Federal Register publication of
                the Call for Information (Call) and the Notice of Intent to Prepare an EIS (NOI). The Call covered all
                unleased blocks in the CPA and WPA, with the exception of two highly sensitive blocks in the WPA: Blocks
                A-375 and A-398 in the High Island Area, East Addition, South Extension (East and West Flower Garden
                Banks, respectively).
                    In late 1990, MMS and the Department of Defense (DOD) agreed to the deferral of the Western Naval
                Operations Area from proposed Western Gulf lease Sales 135 and 141 scheduled for August 1991 and August
                1992. The deferral area, containing 340 lease blocks and approximately 1.7 million acres, is located east of
                Corpus Christi, Texas (Figure I-1). It was also agreed that the deferral would be subject to a two-year review
                period, after which a decision would be made to either continue the deferral for an additional two years or
                move the area to another acceptable location.
                    Consultation has begun between DOD and MMS to review the two-year deferral. Comments received
                from industry concerning this deferral have been relayed to the appropriate parties at DOD. On August 7,
                1991, a meeting was held between MMS, DOD, and industry representatives at the Gulf of Mexico Regional
                Office to discuss the current and planned operational conditions in the deferral area and to allow industry to
                further express their concerns. Industry representatives requested MMS and DOD to consider adjusting the
                configuration and location of the carrier operations area to accommodate industry interest in the area to the
                maximum extent possible within the constraints posed by DOD. The MMS committed to establishing a process
                by which companies can identify areas of interest in or near the Corpus Christi carrier operations area for
                subsequent evaluation by DOD and MMS.

                B. DEVELOPMENT OF THE DRAFT EIS

                    In accordance with NEPA requirements and CEQ regulations, MMS followed scoping procedures for
                contacting and coordinating with Federal, State, and local governments; academic institutions; public interest
                groups; and concerned individuals throughout the development of this document. The scoping process utilized
                in determining the issues and concerns for the proposed 1993 Gulf of Mexico sales is discussed in Section I.B.2.
                At the time of the Call/NOI, the scoping process for the proposed sales was officially initiated. Federal, State,
                and local governments, along with other interested parties, were requested to send written comments to the
                Region on the scope of the EIS. These comments are summarized below.
                C. RESPONSES TO THE CALL FOR INFORMATION AND THE
                     NOTICE OF INTENT TO PREPARE AN EIS

                    There were 10 responses to the Call/NOI--5 from industry, 3 from Federal agencies, 1 from the State of
                Alabama, and 1 from an environmental organization. These comments were considered in the identification
                of the area to be offered for lease in proposed Sales 142 and 143 and in the development of the issues,
                alternatives, and mitigating measures addressed in the Draft EIS.

                    Industry responses were received from the following companies:

                    Mobil Exploration and Producing U.S., Inc.











                 V-4

                     Shell Offshore, Inc.
                     Chevron U.S.A., Inc.
                     Unocal
                     Pogo Producing Company

                     Industry interest and comments as submitted by the companies indicate the following:

                          -        A general support for the continuation of areawide leasing for the 1993 sales in the
                                   Central and Western Gulf of Mexico.


                          -        One company stated it could also support a slower paced leasing alternative for
                                   tracts in water depths greater than 5,000 ft.                        I                                       z

                          -        Support was expressed for the annual offering of the CPA and WPA-

                          -        Two companies opposed the deferral of acreage for naval operations in the Western
                                   Gulf.


                          -        One company recommended MMS remain flexible regarding the naval operations
                                   area and refrain from making this a permanent deferral.

                          -        One company expressed support for the current minimum bid requirernent and
                                   recommended a fixed 10-year term for leases in all water depths greater than 400
                                   In.

                          -        One company supported the continuation of all current lease terms.

                          -        One company suggested including the entire OCS off Alabama in the CPA (except
                                   any acreage subject to existing moratoria).

                          -        Two companies identified and prioritized specific areas of interest for leasing in the
                                   Central and Western Gulf OCS.


                     The Department of the Navy expressed concern for the provision of safe and adequate sea room for
                 training carrier operations in the Western Gulf. They are currently working with MMS on the development
                 of an appropriate deferral configuration for consideration in the presale process for Sale 143.
                     The State of Alabama expressed support for the centralization of gas cleansing and processing facilities
                 in southern Alabama but maintained that the affected coastal communities should share in the financial benefits
                 resulting from this OCS production. The States of Louisiana, Texas, and Mississippi did not respond to the
                 Call.
                     Several commentors expressed concerns of an environmental nature. These commentors were the U.S.
                 Fish and Wildlife Service (FWS), the U.S. Environmental Protection Agency (USEPA), the State of Alabama,
                 and Project ReeflKeeper (an environmental group). When submitting their comments on the Call/NOI, the
                 USEPA also attached a copy of their comments on the Draft EIS for proposed lease Sales 139 and 141 (1992
                 lease sales), and these are also included in the summary list presented below. Project Reefkeeper, in their
                 response to the Call/NOI, attached a copy of their comments on proposed lease Sales 131 and 135, and these
                 are also included in the summary list presented below.

                     Environmental comments and concerns received in response to the Call/NOI include the following.











                                                                                                                             V-5

                U.S. Fish and Wildlife Service

                                   The FWS noted that their Panama City Field Office continues to provide biological
                                   information to the MMS Gulf of Mexico OCS Office as it becomes available and
                                   continues to work cooperatively with the office on a regular basis to identify and
                                   assist in resolving resource issues.

                U.S. Environmental Protection Agency

                          -        The MMS should undertake a comprehensive ozone study.

                          -        The MMS should provide an interim ozone air quality analysis in the next draft EIS.

                          -        The USEPA is concerned about the beach litter problem in the Gulf of Mexico.

                          -        Industry should be more diligent in securing operational debris to reduce the
                                   problem of marine debris.

                          -        The USEPA objects to unrestricted leasing without inclusion of protective
                                   stipulations to protect biologically sensitive habitats including topographic features
                                   and pinnacles.

                          -        The USEPA is concerned about the discharge of produced waters into coastal water
                                   bodies and about impacts to estuarine animals.

                State of Alabama

                     The State of Alabama supports the existing Live Bottom Stipulation applied to the pinnacle trend areas
                in the Main Pass and Viosca Knoll Areas.

                Project ReefKeeper

                          -        The Pinnacle   Trend and other shelf-edge coral banks should be safeguarded by
                                   deleting them from lease sales.

                          -        Project ReefKeeper requests deletion of all Gulf coral habitat areas.

                          -        They are concerned about impacts to the Flower Garden Bank and 19 other shelf-
                                   edge banks off Texas and Louisiana.

                          -        They are concerned about the, impacts of anchoring, discharge of drilling muds and
                                   cuttings, and explosive structure removals on shelf-edge banks.

                          -        They are concerned about the impacts of oil from a pipeline break or subsurface
                                   blowout.


                          -        They are concerned about the long recovery period for damaged coral ecosystems.










             V-6
             D. DISTRIBUTION OF THE DRAFT EIS FOR REVIEW AND
                  COMMENT

                The following public and private agencies and groups will be provided the opportunity to review and
             comment on this Draft EIS.


             Federal Agencies

             Congress
                Congressional Budget Office
                  House Committee on Merchant Marine and Fisheries
                        Subcommittee on Panama Canal and OCS
                  Senate Committee on Energy and Natural Resources
                        Subcommittee on Energy and Mineral Resources
             Department of Commerce
                National Marine Fisheries Service
                National Oceanic and Atmospheric Administration
                  Office of Ecology and Environmental Conservation
                  Office of Ocean and Coastal Management
             Department of Defense
                Department of the Air Force
                Department of the Army
                  Corps of Engineers
                Department of the Navy
             Department of Energy
             Department of the Interior
                Bureau of Mines
                Fish and Wildlife Service
                Geological Survey
                Minerals Management Service
                National Park Service
                  Gulf Island National Seashore
                  Office of Environmental Project Review
                  Padre Island National Seashore
             Department of State
             Department of Transportation
                Coast Guard
                Office of Pipeline Safety Regulations
             Environmental Protection Agency
             Marine Mammal Commission
             Nuclear Regulatory Commission

             State and Local Agencies


             Alabama
                Governor's Office
                Alabama Department of Environmental Management
                Alabama Department of Conservation and Natural Resources
                Alabama Geological Survey
                Alabama Highway Department











                                                                                                                  V-7


                  Alabama Historical Commission and State Historic
                   Preservation Officer
                  Alabama State Clearinghouse
                  Alabama State Oil and Gas Board
                  Dauphin Island Marine Laboratory
                  State Docks Department

              Mississippi
                  Governor's Office
                  Bureau of Marine Resources
                  Mississippi Department of Archives and History
                  Mississippi Department of Natural Resources
                  Mississippi Department of Wildlife Conservation
                  Mississippi State Clearinghouse
                  State Oil and Gas Board


              Louisiana
                  Governor's Office
                  Department of Culture, Recreation, and Tourism
                  Department of Environmental Quality
                  Department of Natural Resources
                  Department of Transportation and Development
                  Department of Urban and Community Affairs
                  Department of Wildlife and Fisheries
                  Louisiana Geological Survey
                  Louisiana State Archaeologist

              Florida
                  Governor's Office
                  Executive Office of the Governor
                  Florida Department of Community Affairs
                  Florida Department of Environmental Regulation
                  Florida Department of Labor and Employment Security
                  Florida Department of Natural Resources
                  Florida Department of State
                  Florida Game and Freshwater Fish Commission
                  Florida State Clearinghouse
                  Florida State Historic Preservation Officer


              Texas
                  Governor's Office
                  Bureau of Economic Geology
                  Texas A&M University
                  Texas Air Control Board
                  Texas Department of Highways and Public Transportation
                  Texas Employment Commission
                  Texas General Land Office
                  Texas Historical Commission
                  Texas Parks and Wildlife Department
                  Texas Railroad Commission
                  Texas State Clearinghouse
                  Texas Water Commission










                V-8

                    Texas Water Development Board
                    The Attorney General of Texas

                Other


                    Alaska Department of Game and Fish

                Libraries


                Alabama
                    Auburn University Library
                    City of Mobile Public Library
                    City of Montgomery Public Library
                    Dauphin Island Sea Lab Library
                    Gulf Shores Public Library
                    University of Alabama at Huntsville Library

                Florida
                    Charlotte Glades Regional Library
                    Collier County Public Library
                    Florida A&M University, Coleman Memorial Library
                    Florida Atlantic University Library
                    Lee County Library
                    Leon County Public Library
                    Marathon Public Library
                    Northwest Regional Library System
                    St. Petersburg Public Library
                    Tampa-Hillsborough County Public Library
                    University of Florida Library
                    University of Miami Library
                    University of South Florida Library
                    West Florida Regional Library

                Louisiana
                    Calcasieu Parish Library
                    Howard Tilton Memorial Library, Tulane University
                    Lafayette Public Library
                    Louisiana State University Library
                    Louisiana Tech University Library
                    New Orleans Public Library
                    Nicholls State University Library

                Mississippi
                    Gunter Library
                    Harrison County Public Library
                    Jackson George Regional Library System


                Texas
                    Abilene Christian University, Margaret and Herman Brown Library
                    Austin Public Library
                    Baylor University Library
                    Brazoria County Library











                                                                                                                V-9

                 Dallas Public Library
                 East Texas State University Library
                 Houston Public Library
                 Lamar University Library
                 La Ratama Library
                 Rosenburg Library (Galveston)
                 Stephen F. Austin State University, Steen Library
                 Texas A&M University Library
                 Texas Southmost University Library
                 Texas State Library at Austin
                 Texas Technical University Law Library
                 University of Houston Library
                 University of Texas at Arlington Library
                 University of Texas at Dallas Library
                 University of Texas at El Paso Library
                 University of Texas Library
                 University of Texas at San Antonio Library

             Academic Institutions


                 Colorado State University
                 Florida Institute of Oceanography
                 Florida Sea Grant
                 Gulf Coast Research Lab
                 Louisiana State University
                 Louisiana Universities Marine Consortium Council
                 Mississippi Sea Grant Advisory Service
                 Oregon State University
                 Swarthmore College
                 State University System of Florida
                 Texas A&M University
                 University of Wisconsin
                 Woods Hole Oceanographic Institute

             Industrial Firms


                 Amoco Production Company
                 Atlantic Richfield Company
                 Chevron U.S.A. Inc.
                 Conoco Inc.
                 EP Operating Company
                 ERT Houston
                 Exxon Corporation
                 Florida Petroleum Council
                 The Louisiana Land and Exploration Company
                 MAR, Inc.
                 Pennzoil Exploration and Production Company
                 Placid Oil Company
                 Rowan Companies, Inc.
                 Shell Offshore Inc.
                 Texaco Inc.
                 TXP Operating Company










                 V-10

                     Unocal Exploration Corporation
                     Walter Oil & Gas Corporation

                Groups and Individuals

                     Apalachee Audubon Society
                     Audubon Society, Mississippi Coast
                     Audubon Society, Mobile Bay, Alabama
                     Audubon Society, New Orleans, Louisiana
                     Audubon Society, Sanibel, Florida
                     Audubon Society, Southwest Florida
                     Audubon Society, Venice, Florida
                     Center for Environmental Health
                     Coastal Conservation Association
                     Concerned Shrimpers of America
                     Environmental Confederation of Southwest Florida
                     Environmental Information Center (Florida)
                     Fisheries Association, Mississippi Coast
                     Florida Conservation News
                     Florida Public Interest Research Group
                     Florida Wildlife Federation
                     Ft. Myers Beach Chamber of Commerce
                     Fowl River Protective Association, Inc.
                     Greenpeace
                     Gulf of Mexico Fishery Management Council
                     HEART
                     Izaak Walton League of America
                     League of Women Voters
                     Louisiana Environmental Professionals Association
                     Louisiana Nature Center
                     Louisiana Wildlife Biologist Association
                     Louisiana Wildlife Federation
                     LUMCON
                     Lyle St. Amant Marine Lab
                     MANASOTA 88
                     Mississippi Coast Fisheries Association
                     Mississippi Sea Grant Advisory Service
                     Mississippi Wildlife Federation
                     Natural Resources Defense Council, Inc.
                     Organized Florida Fishermen
                     Oystershell Alliance
                     Petroleum Information Corporation
                     Sarasota Audubon Society
                     Save Our Wetlands
                     Sierra Club, Florida Chapter
                     Sierra Club, Houston Chapter
                     Sierra Club, Lone Star Chapter
                     Sierra Club, Long Beach, Mississippi
                     Sierra Club, New Orleans Chapter
                     Southwest Culture Resources Center
                     Tampa Audubon Society
                     Texas Water Conservation Association






















    SECTION VI

    BIBLIOGRAPHY AND                 ---
    SPECIAL REFERENCES              V-L











                                                                                                                              VI-3

               VI. BIBLIOGRAPHY AND SPECIAL REFERENCES

               The following references are cited in the text:

               Acoustic Society of America. 1980. San Diego Workshop on the Interaction Between Man-Made Noise and
                        Vibration and Arctic Marine Wildlife.

               Addy, SX and E.W. Behrens. 1980. Time of accumulation of hypersaline anoxic brine in Orca basin (Gulf of
                        Mexico). Mar. Geol. 37:241-252.
               Ainley, D.G., C.R. Grau, T.E. Rodybush, S.H. Morrell, and J.N. Utts. 1981. Petroleum ingestion reduces
                        reproduction in Cassin's auklets. Mar. Poll. Bull., 12:314-317.

               Alexander, S.Y_ and J.W. Webb. 1983. Effects of oil on growth and decomposition of Spartina alterniflora. In:
                        Proceedings, 1983 Oil Spill Conference, San Antonio, TX Washington, DC: American Petroleum
                        Institute. pp. 529-532.
               Alexander, SX and J.W. Webb. 1985. Seasonal response of Spartina altemiflora to oil. In: Proceedings, 1985
                        oil spill conference, February 25-28, 1985, Los Angeles, CA. Washington, DC: American Petroleum
                        Institute. pp. 355-357.

               Alexander, SX and J.W. Webb. 1987. Relationship of Spartina altemiflora growth to sediment oil content
                        following an oil spill. In: Proceedings, 1987 oil spill conference. . April 6-9, 1988, Baltimore, MD.
                        Washington, DC. American Petroleum Institute. pp. 445-450.

               Alpert, B. Pipeline inspection set in bill. The Times-Picayune, National News, Wednesday, October 17, 1990.
                        p. A-4.

               American Petroleum Institute (API). 1989. Effects of offshore pCtTOleum operations on cold water marine
                        mammals: a literature review. Washington, D.C.: American Petroleum Institute.

               Amos, A. 1991. Monitoring, assessment, and prevention of marine debris on Gulf beaches: post-MARPOL V.
                        As presented at the MMS, Gulf of Mexico OCS Region, Eleventh Annual Information Transfer
                        Meeting, New Orleans, Lk

               Anderson, C. 1990. Personal communication, U.S. Dept of the Interior, Minerals Management Service,
                        Branch of Environmental Operations and Analysis, Herndon, VA.

               Anderson, C.M. and R.P. LaBelle. 1990. Estimated occurrence rates for analysis of accidental off spills on the
                        US outer continental shelf. Oil & Chemical Pollution. England: Elsevier Science Publishers Ltd. pp.
                        21-35.

               Anderson, J.W., J.M. Neff, B.A. Cox, H.E. Tatem, and G.M. Hightower. 1974. Characteristics of dispersions
                        and water-soluble extracts of crude and refined oils and their toxicity to estuarine crustaceans and fish.
                        Mar. Biol. 27:75-88.

               Angelovic, J.W. 1989. Written communication. Condition of the fisheries. St. Petersburg, FL: U.S. Dept.
                        of Commerce, National Marine Fisheries Service, Southeast Fisheries Center, Internal Memorandum.
                        5 pp.











                 VI-4

                 Avery, M.L., P.F. Springer, and N.S. Dailey. 1980. Avian mortality at man-made structures: an annotated
                         bibliography (revised). FWS/OBS-80/54. Washington, DC: U.S. Fish and Wildlife Service, Biological
                         Services Program, National Power Plant Team.

                 Baca, B.J. and C.D. Getter. 1984. The toxicity of oil and chemically dispersed oil to the seagrass Thalassia
                         testudinum. In: Allen, T.E., ed. Oil spill chemical dispersants: research, experience, and
                         recommendations, STP 840. Philadelphia, PA.- American Society for Testing and Materials. pp.
                         314-323.


                 Bahr, L.M. and M.W. Wascom. 1984. Weiland trends and factors influencing wetland use in the area
                         influenced by the lower Mississippi River: a case study. Prepared for the U.S. Congress Office of
                         Technology Assessment by Louisiana State University, Center for Wetland Resources.

                 Bak, R.P.M. and J.H.B.W. Elgershuizen. 1976. Patterns of oil-sediment rejection in corals. Nlar. Biol. 37:105-
                         113.


                 Baker-Hughes. 1990. Rig Count. September 1990.

                 Balazs, G. 1985. Impact of ocean debris on marine turtles: entanglement and ingestion. In: Shomura, R.S.
                         and H.O. Yoshida, eds. Proceedings of the Workshop on the Fate and Impact of Marine Debris,
                         November 27-29, 1984, Honolulu, Hawaii. U.S. Dept. of Commerce, NOAA Tech. Memo.
                         NMF'S-NOAA-TM-NMFS-SWFS-54. pp. 387-429.

                 Balsillie, J.H. 1985. Post-storm report: Hurricane Elena of 29 August to 2 September 1985. Beaches and shores
                         post-storm report no. 85-2. Florida Dept. of Natural Resources. Tallahassee, FL.

                 Bao-Kang. 1987. Analysis of significant oil spill incidents from ships, 1976-1985. In: Proceedings, 1987 oil spill
                         conference, April 6-9, 1987, Baltimore, MD. Washington, DC- American Petroleum Institute. pp.
                         4347.


                 Barkuloo, J.M. 1988. Report on the conservation status of the Gulf of Mexico sturgeon, Acipenser oxyrhynchus
                         desotoL U.S. Fish and Wildlife Service, Panama City, FL.

                 Barnard, W.R. and P.N. Froelich, Jr. 1981. Nutrient geochemistry of the Gulf of Mexico. In: Proceedings
                         of a symposium on environmental research needs in the Gulf of Mexico (GOMEX), K ey Biscayne, FL,
                         30 September-5 October, 1979. Miami, FL: U.S. Dept of Commerce, Atlantic Oceanographic and
                         Meteorological Laboratories. Vol. 2A, pp. 128-135.

                 Barrett, B.B., J. W. Tarver, W.R. Latapie, J.F. Pollard, W.R. Mack, G.B. Adkins, W.J. Gaidry, C.J. White, and
                         J.S. Mathis. 1971. Cooperative Gulf of Mexico estuarine inventory and study, Louisiana: phase 11,
                         hydrology. New Orleans, LA. Louisiana Wildlife and Fisheries Commission. pp. 9-130.

                 Baxter, VX 1990. Common themes of social institution impact and response. As presented in the "Impact of
                         Offshore Oil Exploration and Production on the Social Institutions of Coastal Louisiana" session of the
                         MMS, Gulf of Mexico OCS Region, Tenth Annual Information Transfer Meeting, November 13-15,
                         1990. New Orleans, Lk

                 Bedinger, C.A., ed. 1981. Ecological investigations of petroleum production platforms in the central Gulf of
                         Mexico. Volume 1: Pollutant fate and effects studies. Prepared by the Southwest Research Institute
                         for the Bureau of Land Management under contract no. AA551-CT8-17. San Antonio, TX











                                                                                                                          VI-5


               Bellrose, F.C 1968. Waterfowl migration corridors East of the Rocky Mountains in the United States. Illinois
                        Natural History Survey,'Biological Notes No. 61. State of Illinois Dept. of Registration and Education
                        Natural History Survey Division. 24 pp.

               Bender, M.E., J.M. Sharp, D.J. Reish, S.G. Appan, and CH. Ward. 1979. An independent appraisal of the
                        offshore ecology investigation. In: Proceedings 11th Annual Offshore Technology Conference,
                        April 30-May 3, 1979, Houston, TX pp. 2163-2172.

               Berrigan, M.E. 1986. Personal communication. Florida Dept of Natural Resources, Tallahassee, FL. In: U.S.
                        Dept. of the Interior, Minerals Management Service. 1986. Final environmental impact statement,
                        proposed OCS oil and gas lease Sales 110 and 112 (central and western Gulf of Mexico)--Appendix
                        D. OCS EIS/EA MMS 86-0087.

               Berry, W.L. 1972. Pollution control aspects of the Bay Marchand fire. Jour. Petrol. Tech. 24(3):241-249.

               Berryhill, H.L. 1987. Late quaternary facies and structure, northern Gulf of Mexico: interpretations from
                        seismic data. Association of American Petroleum Geologists Studies in Geology no. 23, Tulsa, OK 289
                        PP.

               Blumer, M. 1971. Scientific aspects of the oil spill problem. Environ. Aff. 1:54-73.

               Bobra, M.A., P.I. Kawamura, M. Fingas, and D. Velicogna. 1987. Laboratory and tank test evaluation of
                        Elastol. In: Proceedings of the Tenth Arctic and Marine Oilspill Program Technical Seminar,
                        Edmonton, Alberta, Canada; June 9-11, 1986.

               Boehm, P.D. and D.L. Fiest. 1982. Subsurface distributions of petroleum from an offshore well blowout - the
                        IXTOC-1 blowout, the Bay of Campeche. Environmental Science and Technology 16:67-74.

               Boesch, D.F. 1988. Environmental effects of coastal produced water discharges: ongoing and planned studies.
                        In: Proceedings: Spring ternary, Gulf of Mexico studies meeting, March 1988. Prepared for the U.S.
                        Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA
                        by Geo-Marine, Inc. OCS Study MMS 88-0041. pp. 37-40.

               Boesch, D.F. and N.N. Rabalais, eds. 1987. Long-term environmental effects of offshore off and gas
                        development Essex, NY: Elsevier Applied Science Publishers Ltd. 708 pp.

               Boesch, D.F. and N.N. Rabalais. 1989a. Produced waters in sensitive coastal habitats: an analysis of impact,
                        central coastal Gulf of Mexico. Prepared under MMS Contract 14-12-001-30325. New Orleans, LA.-
                        U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region. OCS Study
                        MMS 89-0031. 157 pp.

               Boesch, D.F. and N.N. Rabalais. 1989b. Environmental impact of produced water discharges in coastal
                        Louisiana. Report prepared for the Louisiana Division of the Mid-ContinentOil and Gas Association.
                        July 1989. 287 pp.

               Bohlinger, H.L. 1990. Regulation of naturally occurring radioactive material in Louisiana. In: Proceedings of
                        the First International Symposium on Oil and Gas Exploration and Production Waste Management
                        Practices. U.S. Environmental Protection Agency. pp. 833-840.











                 VI-6

                 Bortone, S.A. and J.L. Williams. 1986. Species profiles: life histories and environmental requirements of coastal
                          fishes and invertebrates (south Florida)--gray, lane, mutton, and yellowtail snappers. U.S. Fish and
                          Wildlife Service, Biological Report 82(11.52). U.S. Army Corps of Engineers, TR EL-82-4. 18 pp.

                 Brandsma, M.G. and R.C. Sauer. 1983. The OOC model: prediction of short term fate ofdrilling fluids in
                          the ocean. Part two: model results. In: Proceedings of Minerals Management Service Workshop on
                          Discharges Modeling, Santa Barbara, CA, February 7-10, 1983.

                 Brandy, J.E. 1971. History of oil well drilling. Houston, TX Gulf Publishing Company. 1,525 pp.

                 Brazzel, J. 1992. Personal communication. Manager, Campbell Wells, Jennings, LA_

                 Bright, T.J. 1975. Personal communication. Texas A&M University, College Station, TY_

                 Bright, T.J. and W.C. Jaap. 1976. Ecology and management of coral reefs and organic banks. Paper
                          presented at the annual meeting of the American Institute of Biological Sciences in New Orleans, 1A
                          June 1, 1976.

                 Bright, T.J. and R. Rezak. 1978. Northwestern Gulf of Mexico topographic features study. Final report to
                          the BLM, Contract No. AA550-M-15. College Station, TX Texas A&M Research Foundation and
                          Texas A&M University, Department of Oceanography-, 667 pp. Available from NTIS, Springfield, VA.-
                          PB-294-769/AS.

                 Bright, T.J., G.P. Kraemer, G.A_ Minnery, and S.T. Viada. 1984. Hermatypes of the Flower Garden Banks.
                          Bull. Mar. ScL 34(3):461-476.

                 Bright, T.J., J.W. Tunnell, L.H. Pequegnat, T.E. Burke, C.W. Cashman, D.A. Cropper, J.P. Ray, R.C. Tresslar,
                          J. Teerling, and J.B. Wills. 1974. Biotic zonation on the West Flower Garden Bank. pp. 4-45. Bright,
                          T.J. and L. Pequegnat, eds. Biota of the West Flower Garden Bank. Houston, TX Gulf Publishing
                          Company. 435 pp.
                 Brinkman, R. 1991. Personal communication. Telephone conversation regarding seismic activity in the Gulf of
                          Mexico. September 24,1991. New Orleans, LA.

                 Britsch, L.D. and E.B. Kemp. 1990. Land loss rates: Mississippi River Deltaic Plain. U.S. Dept. of the Army,
                          Waterways Experiment Station, Vicksburg, MS. Technical Report GL-09-2. 25 pp.

                 Brook-VanMeter, V. 1987. Florida's sea turtles. Florida Power and Light Company. #83809-807.

                 Brookhaven National Laboratory. 1991. Produced water radionuclide hazard/risk assessment - Phase I.
                          Hamilton, L.D., A.F. Meinhold, and J. Nagy. API Publication. In press.

                 Brooks, J.M. 1979. Sources and distributions of petroleum hydrocarbons in the Gulf of Mexico: summary of
                          existing knowledge. Texas A&M University, Dept. of Oceanography, Technical Report 80-17-T.

                 Brooks, J.M. and B.B. Bernard. 1977. Report to Pennzoil Oil Company through Decca Survey Systems, Inc.
                          on geochernical study around a platform blowout in High Island, South Addition, Block 563. Houston,
                          TX Pennzoil Co.











                                                                                                                        VI-7

              Brooks, J.M. and C.P. Giammona, eds. 1988. Mississippi Alabama marine ecosystem study, annual report year
                       2. Volume 1: Technical narrative. OCS Study MMS 89-0095. U.S. Dept of the Interior, Minerals
                       Management Service, Gulf of Mexico OCS Region, New Orleans, I.A 348 pp.

              Brooks, J.M., B.B. Bernard, and W.M. Sackett. 1977. Input of low-molecular-weight hydrocarbons from
                       petroleum operations into the Gulf of Mexico. In: Wolfe, D.A., ed. Fate and effects of petroleum
                       hydrocarbons in marine organisms and ecosystems. Pergamon Press. pp. 373-384.

              Brooks, J.M., H.B. Cox, W.R. Bryant, M.C. Kennicutt 11, R.G. Mann, and T.J. McDonald. 1986a. Association
                       of gas hydrates and oil seepage in the Gulf of Mexico. Org. Geochem. 10:221-234.

              Brooks, J.M., M.C. Kennicutt 11, and R.R. Bidigare. 1986b. Final cruise report for Offshore Operators
                       Committee study of chemosynthetic marine ecosystems in the Gulf of Mexico. Geochemical and
                       Environmental Research Group, Department of Oceanography, Texas A&M University, College
                       Station, TX

              Brooks, J.M., M.C. Kennicutt 11, C.R. Fisher, S.A_ Macko, K Cole, J.J. Childress, R.R. Bidigare, and R.D.
                       Vetter. 1987. Deep-sea hydrocarbon seep communities: evidence for energy and nutritional carbon
                       sources. Science 238:1138-1142.


              Brooks, J.M., M.C. Kennicutt 11, I.R. MacDonald, D.L. Wilkinson, N.L. Guinasso, Jr., and R.R. Bidigare. 1989.
                       Gulf of Mexico hydrocarbon seep communities: part IV--descriptions of known chemosynthetic
                       communities. Offshore Technology Conference, May 14, 1989, Houston, TX

              Brower, W.A., J.M. Meserve, and R.G. Quayle. 1972. Environmental guide for the U.S. Gulf Coast. Asheville,
                       NC: U.S. National Climatic Center. 177 pp.

              Brown, L.R. 1980. Fate and effect of oil in the aquatic environment, Gulf Coast region. . final report.
                       EPA/600/3-80-058a. Mississippi State, MS: Mississippi State University. 114 pp. Available from
                       NTIS, Springfield, VA; PB81-142499.

              Burns, KA. In Press. Hydrocarbon analyses. pp. 85-104. In: Keller, B.D. and J.B.C. Jackson, eds. Long-term
                       assessment of the oil spill at Bahia Las Minas, Panama, interim report supplemen U.S. Dept. of the
                       Interior, Minerals Management Service, Gulf of Mexico OCS Regional Office, New Orleans, LA. OCS
                       Study MMS 91-0049.

              Burns, KA. and A.H. Knap. 1989. The Bahia Las Minas off spill: hydrocarbon uptake by reef building corals.
                       Mar. Poll. Bull. 20: 391-398.

              Burrell, V.G., Jr. 1986. Species profiles: life histories and environmental requirements of coastal fishes and
                       invertebrates (south Atlantic)--American oyster. U.S. Fish and Wildlife Service. Biological Report
                       82(11.57). U.S. Army Corps of Engineers, TR EL-824. 17 pp.

              Butler, J.N., B.F. Morris, and J. Sass. 1973. Pelagic tar from Bermuda and the Sargasso Sea. Bermuda Biol.
                       Stn. Res. Special publication No. 10. (St. George's West): Bermuda Biological Station for Research;
                       346 pp.

              Butler, J.N., B.F. Morris, and T.D. Sleeter. 1976. The fate of petroleum in the open ocean. In: Proceedings
                       of the symposium: sources, effects, and sinks of hydrocarbons in the aquatic environment, Washington,
                       DC, August 9-11, 1976. Arlington, VA_- American Institute of Biological Sciences. pp. 287-297.










                 VI-8

                 Byles, R.A. 1989. Satellite telemetry of Kemp's ridley sea turtle, Lepidochelys kempi, in the: Gulf of Mexico.
                         In: Eckert, S.A-, K.L. Eckert, and T.H. Richardson, comp. Proceedings of the Ninth Annual
                         Workshop on Sea Turtle Conservation and Biology.                   NOAA Technical Memorandum
                         NMFS-SEFC-232. 306 pp.

                 Byrd, M.A. 1978. Dispersal and movements of six North American Ciconfiforms. In: Sprunt A., IV, J.C.
                         Ogden, and S. Winckler, eds. Wading birds. National Audubon Society, New York, NY. pp. 161-185.

                 Cahoon, D.R. and C.G. Groat, eds. 1990. A study of marsh management practice in coastal Louisiana, volume
                         I: executive summary. Final report submitted to the U.S. Dept. of the Interior, Minerals Management
                         Service, Gulf of Mexico OCS Region, New Orleans, LA. Contract no. 14-12-Offll-30410. OCS Study
                         MMS 90-0075. 36 pp.

                 Caillouet, C.W., Jr. and A.M. Land ry, Jr. (compilers). 1989. Proceedings of the first international symposium
                         on Kemp's ridley sea turtle biology, conservation, and management Texas A&M University Sea Grant
                         Publication 89-105, August 1989.

                 Caillouet, C.W., W.B. Jackson, G.R. Gitschlag, E.P. Wilkens, and G.M. Faw. 1981. Review of the
                         environmental assessment of the Buccaneer gas and oil field in the northwestern Gulf of Mexico. In:
                         Proceedings of the Thirty-third Annual Gulf and Caribbean Fisheries Institute, SanJose, Costa Rica;
                         November 1980. Miami, FL: GCFI; June 1981. pp. 101-124.

                 Caillouet, C.W., AM. Landry, M.J. Duronslet, S.A. Manzella, C.T. Fontaine, D.B. Revera, K.L. Indelicato, T.D.
                         Williams, and D. Fo rcucci. 1986. Preliminary evaluation of biological impacts of underwater explosions
                         associated with removal of an oil field structure from the Gulf of Mexico near Crystal Beach, Texas.
                         U.S. Dept. of Commerce, National Marine Fisheries Service, Southeast Fisheries Ctitter. 32 pp.

                 Calhoun, M. 1988. Louisiana almanac: 1988-1989. Gretna, Lk- Pelican Publishing Co.

                 Canevari, G.P. 1985. The effect of crude oil composition on dispersant performance. In: Proceedings, 1985
                         oil spill conference, February 25-28, 1985, Los Angeles, CA. Washington, DC. American Petroleum
                         Institute. pp. 441-444.

                 Carr, A. 1987. Impact of nondegradable marine debris on the ecology and survival outlook of sea turtles. Mar.
                         Poll. Bull. 18:352-356.


                 Caruso, B. 1989. Personal communication, Tidewater Marine, Inc., New Orleans, LA.

                 Caruthers, J.W. 1972. Water masses at intermediate depths. In: Capurro, L.R.A. and. J.L. Reid, eds.
                         Contributions on the pyysical oceanography of the Gulf of Mexico, volume 2. Texas A&M University
                         Oceanographic Studies. Houston, TX Gulf Pub. Co. pp. 53-63.

                 Cary, C., B. Fry, H. Felbeck, and R.D. Vetter. 1989. Multiple trophic resources for a chemoautotrophic
                         community at a cold water brine seep at the base of the Florida Escarpment. Mar. Biol. 100:411418.

                 Cato, J.C., F.J. Prochaska, and P.C.H. Pritchard. 1978. An analysis of the capture, marketing and utilization
                         of marine turtles. Purchase Order 01-7-042-11283. St Petersburg, FL: National Marine Fisheries
                         Service. 119 pp.

                 Centaur Associates, Inc. 1985. Facilities related to Outer Continental Shelf oil and gas development offshore
                         California: a factbook. U.S. Dept. of the Interior, Minerals Management Service, Pacific OCS Region.
                         Contract No. 14-12-OWl-30164. 180 pp.











                                                                                                                           VI-9

                Centaur Associates, Inc. and Center for Environmental Education. 1986. Issue report and work plan for the
                        development of a marine debris education program for the northwestern Atlantic and Gulf of Mexico.
                        Prepared for the U.S. Dept. of Commerce, National Marine Fisheries Service. 62 pp.

                Center for Environmental Education, undated. Sea turtles and shrimp trawlers. Center for Marine
                        Conservation, Washington, D.C. Center for Marine Conservation. 1989. Trash on America's beaches:
                        a national assessment. Washington, DC.

                Chan, E.I. 1977. Oil pollution and tropical littoral communities: biological effects at Florida Keys oil spill.
                        In: Proceedings, 1977 oil spill conference, March 8-10, 1977, New Orleans, LA- Washington, DC:
                        American Petroleum Institute. pp. 539-542.

                Chatry, M. 1986. Personal communication. Louisiana Dept of Wildlife and Fisheries, Grand Isle, LA. In: U.S.
                        Dept. of the Interior, Minerals Management Service. 1986. Final environmental impact statement,
                        proposed OCS oil and gas lease Sales 110 and 112 (central and western Gulf of Meidco)--AppendLx
                        D. OCS EIS/EA MMS 86-0087.

                Chen, KY., SK Gupta, A.7- Sycip, J.C.S. Lu, M. Knezevic, and W. Choi. 1976. Research study on the effect
                        of dispersion, settling, and resedimentation of chemical constituents during open-water disposal of
                        dredged materials. U.S. Dept. of the Army, Corps of Engineers, Waterways Experiment Station,
                        Vicksburg, MS. Contract report D-76-1.

                Choi, D.R. 1982. Coelobites (reef cavity dwellers) as indicators of environmental effects caused by offshore
                        drilling. Bull. Mar. Sci. 32:880-889.

                Christmas, J.Y. and C.K Eleuterius. 1973. Hydrology, Phase 11. In: Christmas, J.Y., ed. Cooperative Gulf
                        of Mexico estuarine inventory and study, Mississippi. Ocean Springs, MS: Gulf Coast Research
                        Laboratory, Mississippi Marine Conservation Commission. pp. [731-121.

                Christmas, J.Y. and R.S. Waller. 1975. Location and time of menhaden spawning in the Gulf of Mexico.
                        Performed with the National Marine Fisheries Service under Contract No. 03-4-042-24. Ocean Springs,
                        MS: Gulf Coast Research Laboratory. 20 pp.

                Christmas, J.Y., D.J. Etzold, L.B. Simpson, and S. Meyers. 1988. The menhaden fishery of the Gulf of Mexico
                        United States: a regional management plan. Gulf States Marine Fisheries Commission. Ocean
                        Springs, MS. 139 pp.

                Christmas, J.Y., J.T. McBee, R.S. Waller, and F.C. Sutter 111. 1982. Habitat suitability index models: Gulf
                        menhaden. U.S. Dept. of the Interior, Fish and Wildlife Service. FWS/OBS-82/10.23. 23 pp.

                Christmas, J.Y. and R.S. Waller. 1975. Location and time of menhaden spawning in the Gulf of Mexico. Gulf
                        Coast Research Laboratory, Ocean Springs, MS, for the U.S. Dept. of Commerce, National Marine
                        Fisheries Service Contract No. 03-4-042-24. 24 pp.

                Clagett, J. 1990. Written communication. 1989 fishing license data. Texas Parks and Wildlife, Coastal
                        Fisheries Division, computer data. 4 pp.

                Clapp, R.B., R.C. Banks, D. Morgan-Jacobs, and W.A. Hoffman. 1982a. Marine birds of the southeastern
                        United States and Gulf of Mexico. Volume 1. Gaviiformes. Washington, DC: U.S. Fish and Wildlife
                        Service, Office of Biological Services. FWS/OBS-82/01.










                 VI-10
                 Clapp, R.B., R.C. Banks, D. Morgan-Jacobs, and W.A. Hoffman. 1982b. Marine birds of the southeastern
                          United States and Gulf of Mexico. Volume 11. Pelicaniformes. Washington, DC: U.S. Fish and
                          Wildlife Service, Office of Biological Services. FWS/OBS-82/01.
                 Clark, J. 1976. Barrier islands and beaches - technical proceedings of the Barrier Island Workshop. Prepared
                          for The Conservation Foundation.

                 Clausen, C.J. and J.B. Arnold 111. 1975. Magnetic delineation of individual shipwreck sites; a new control
                          technique. Bull. of the Texas Archaeological Soc. 46:69-86.
                 Clean Gulf Associates (CGA). 1989. Clean Gulf Associates Operations Manual, Volume 1, Administration
                          and Equipment. Clean Gulf Associates.
                 Clean Gulf Associates (CGA). 1991. Clean Gulf Associates quarterly status report no. 65.
                 Cleveland, C.J., C. Neill, and J.W. Day, Jr. 1981. The impact of artificial canals on land loss in the Barataria
                          Basin, Louisiana. Paper presented at the International Symposium for Energy and Ecological
                          Modelling, April 20-23, 1981, Louisville, KY. Sponsored by the International Society for Ecological
                          Modelling.
                 Coastal Environments, Inc. (CEI). 1977. Cultural resources evaluation of the Northern Gulf of Mexico
                          continental shelf. Prepared for Interagency Archaeological Services, Office of Archaeology and
                          Historic Preservation, National Park Service, U.S. Dept. of the Interior. Baton Rouge, LA. 4 vols.
                 Coastal Environments, Inc. (CEI). 1982. Sedimentary studies of prehistoric archaeological sites. Prepared
                          for. Division of State Plans and Grants, National Park Service, U.S. Dept. of the Interior. Baton
                          Rouge, LA
                 Coastal Environments, Inc. (CEI). 1986. Prehistoric site evaluation on the northern Gulf of Mexico outer
                          continental shelf. ground truth testing of the predictive model. Prepared for the U.S. Dept of the
                          Interior, Minerals Management Service.
                 Cochrane, J.D. and F.J. Kelly. 1986. Low-frequency circulation on the Texas-Louisiana continental shelf.
                          Journal of Geophysical Rescarch 91(C9):10,645-10,659.
                 Cohen, L.M. 1984. Chinese in the post-Civil War South: a people without a history. Baton Rouge, LA.
                          Louisiana State University Press. 211 pp.
                 Cole, C.A_, J.P. Kumer, D.A. Manski, and D.V. Richards. 1990. Annual report of national park marine debris
                          monitoring program: 1989 marine debris survey. Washington, DC: U.S. Dept. of the Interior, National
                          Park Service. Technical Report NPS/NRWV/NRTR-90/04.
                 Collard, S.B. and L.H. Ogren. 1989. Dispersal scenarios for pelagic post-hatchling sea turtles. Bulletin of
                          Marine Science.

                 CONCAWE. 1981. A field guide to coastal oil spill control and cleanup techniques, Report No. 9/81.
                          CONCAWE, The Hague.
                 Connor, J.G., Jr. 1990. Underwater blast effects from explosive severance of offshore platlbrm legs and well
                          conductors. Naval Surface Warfare Center, Silver Springs, MD. NAVSWC TR 90-532. 34 pp.










                                                                                                                        VI-11

               Continental Shelf Associates, Inc. (CSA). 1982. Study of the effect of oil and gas activities on reef fish
                        populations in the Gulf of Mexico OCS area: executive summary. Prepared for the U.S. Dept. of the
                        Interior, Bureau of Land Management, New Orleans OCS Office under Contract No. AA551-M-36.
                        Tequesta, Fl- 14 pp.

               Continental Shelf Associates, Inc. (CSA). 1985. Live-bottom survey of drill-site locations in Destin Dome Area
                        Block 617. February 1985.

               Continental Shelf Associates, Inc. (CSA). 1987. Assessment of hurricane damage in the Florida Big Bend
                        seagrass beds. Prepared under MMS Contract No. 14-12-OWl-30188. New Orleans, LA.- U.S. Dept.
                        of the Interior, Minerals Management Service, Gulf of Mexico OCS Region. OCS Study MMS
                        87-"l. 95 pp.

               Continental Shelf Associates, Inc. (CSA). 1989. Site-specific oil spill contingency plan prepared for Mobil
                        Exploration and Producing U.S. Inc., for Pensacola Area, Blocks 845, 846, 889, 890, 933, 934.
                        Continental Shelf Associates, Jupiter, FL.

               Corcoran, E.F. 1973. Chemical oceanography. In: Jones, J.I., R.E. Ring, M.O. Rinkel, and R.E. Smith, eds. A
                        summary of knowledge of the eastern Gulf of Mexico. St. Petersburg, FL. State University System of
                        Florida, Institute of Oceanography. pp. IICl-IIC86.

               Corliss, J.B., J. Dymond, L.I. Gordon, J.M. Edmond, R.P. von Herzen, R.D. Ballard, K Green, D. Williams,
                        A. Bainbridge, IC Crane, and T.H. van Andel. 1979. Submarine thermal springs on the Galapagos
                        Rift. Science 203:1073-1083.


               Crawford, W.W. 1991. Personal communication. Conversation regarding past, present, and probable future
                        types and uses of explosives to remove platforms from the Gulf of Mexico, during pre-job meeting
                        concerning removal of OXY USA, HI-520-A structure, August 13,1991. DEMEX Intemational,LTD.
                        Teledyne Movible Offshore, Ameila, LA.

               Crawley, W.W. and R.T. Branch. 1990. Characterization of treatment zone soil conditions at a commercial
                        nonhazardous oilfield waste land treatment unit. In: Proceedings of the First International Symposium
                        on Oil and Gas Exploration and Production Waste Management Practices. U.S. Environmental
                        Protection Agency. pp. 147-158.

               Crocker, M.J. 1985. Design considerations for a large sweep width skimming system. In: Proceedings, 1985
                        Oil Spill Conference, February 25-28,1985, Los Angeles, CA. Washington, DC- American Petroleum
                        Institute. pp. 47-50.

               Dallmeyer, D.G., J.W. Porter, and G.J. Smith. 1982. Effects of particulate peat on the behavior and physiology
                        of the Jamaican reef-building coral Montastrea annularis. Mar. Biol. 68:229-233.

               Darnell, R.M. 1988. Marine biology. In: Phillips, N.W. and B.M. James, eds. Offshore Texas and Louisiana
                        marine ecosystems data synthesis. Draft final report to the Minerals Management Service, Gulf of
                        Mexico OCS Region, Contract No. 14-12-OMI-30380. Vol. II, pp. 203-338.

               Darnell, R.M. and J.A- Kleypas. 1987. Eastern Gulf shelf bio-atlas: a study of the distribution of demersal
                        fishes and penacid shrimp of soft bottoms of the continental shelf from the Mississippi River delta to
                        the Florida Keys. OCS Study MMS 86-0041. 548 pp.

               Darnell, R.M. and T.M. Soniat. 1979. The estuary/continental shelf as an interactive system. In: Livingston,
                        R.J., ed. Ecological processes in coastal and marine systems. Plenum Press. 39 pp.










               VI-12

               Darnell, R.M., R.E. Defenbaugh, and D. Moore. 1983. Atlas of biological resources of the o:)ntinental shelf,
                       NW Gulf of Mexico. BLM Open File Report No. 82-04. New Orleans, LA: U.S. Dept. of the
                       Interior, Bureau of Land Management.

               Davenport, G. 1991. Written communication. 1990. Commercial fishery landings by species, State, and Gulf-
                       wide. Miami, FL. U.S. Dept. of Commerce, National Marine Fisheries Service, Statistics Division,
                       Computer Generated Landings Data. 8 pp.

               Defenbaugh, R.E. 1976. A study of the benthic macroinvertebrates of the continental shelf of the northern
                       Gulf of Mexico. Unpublished Ph.D. dissertation. College Station, TX Texas A&M University. 476
                       PP.

               Delaune, R.D., W.H. Patrick, and R.J. Bureh. 1979. Effect of crude oil on a Louisiana Spailina altemiflora
                       salt marsh. Environ. Poll. 20:21-31.

               Delfino, J.J., D.L. Frazier, and J.L. Nepshinsky. 1984. Contaminants in Florida's coastal zone: a review of
                       present knowledge and proposed research strategies. A summary of a workshop held April 5-6, 1984.
                       Sea Grant Project No. IR-83-13. Report Number 62, Florida Sea Grant College.

               Delvigne, G.A.L. 1985. Experiments on natural and chemical dispersions of oil in laboratory and field
                       circumstances. pp. 507-514. In: Proceedings of the 1985 Oil Spill Conference, American Petroleum
                       Institute, Washington, DC. 651 pp.

               Demond, J. 1991. Personal communication. Manager, Consistency Section, Coastal Management Division,
                       Louisiana Dept. of Natural Resources.

               DeWald, 0. 1982. Severe storm and hurricane impacts along the Gulf and lower Atlantic coasts. In: U.S.
                       Dept. of the Interior, Bureau of Land Management Environmental information on hurricanes,
                       deepwater technology, and Mississippi Delta mudsfides in the Gulf of Mexico, Section III. BLM Open
                       File Report 80-02. New Orleans, LA. 10 pp.

               Dillon, T.M., J.M. Neff, and J.S. Warner. 1978. Toxicity and sublethal effects of No. 2 fuel oil on the
                       supralittoral Lygia exotica. Bull. Environ. Contain. Toxicol. 20:320-327.
               Ditton, R.B. and J. Auyong. 1984. Fishing offshore platforms central Gulf of Mexico - An analysis of
                       recreational and commercial fishing use at 164 major offshore petroleum structures.               OCS
                       Monograph/MMS 844X)06. Metairie, LA. Minerals Management Service, Gulf of Mexico OCS
                       Regional Office. 158 pp. Available from NTIS, Springfield, VA-- PB84-216605.

               Ditton, R.B. and A.R. Graefe. 1978. Recreational fishing use of artificial reefs on the Texas coast. College
                       Station, TX Texas A&M University, Department of Recreation and Parks. 155 pp.

               Dodge, R.E., S.C. Wyers, H.R. Frith, A.H. Knap, S.R. Smith, and T.D. Sleeter. 1984. The effects of oil and oil
                       dispersants on the skeletal growth of the hermatypic coral Diploria strigosa. Coral Reefs 3:191-198.

               Dolan et al. 1982. In: Coastal barrier resource system - draft report to Congress. U.S. Dept. of the Interior.

               Ducks Unlimited. 1989. Status and condition of North American waterfowl populations. 36)(3):5-7.

               Dugas, R., V. Guillory, and M. Fischer. 1979. Oil rigs and offshore fishing in Louisiana. Fisheries 4(6):2-10.











                                                                                                                          VI-13

               Dunbar, J.B., LD. Britsch, and E.B. Kemp. 1990. Land loss rates: report 2, Louisiana Chenier Plain. U.S.
                        Dept. of the Army, Corps of Engineers, Waterways Experiment Station, Vicksburg, MS. Technical
                        report GL-90-2. 21 pp.

               Duronslet, M.J., C.W. Caillouet, S. Manzella, Y-W. Indelicato, C.T. Fontaine, D.B. Revera, T. Williams, and
                        D. Boss. 1986. The effects of an underwater explosion on the sea turtles Lepidochelys kempi and
                        Carelta careua with observations of effects on other marine organisms (trip report). Galveston, TX
                        U.S. Dept. of Commerce, National Marine Fisheries Service, Southeast Fisheries Center.

               Ecomar, Inc. 1980. Maximum and discharge study conducted for Offshore Operators Committee,
                        Environmental Subcommittee under direction of Exxon Production Research Company. New Orleans,
                        LA. Offshore Operators Committee. 114 pp.

               El-Sayed, S.Z 1972. Primary productivity and standing crop of phytoplankton in the Gulf of Mexico. In: El-
                        Sayed, S.Z et al., eds. Chemistry, primary productivity and benthic algae of the Gulf of Mexico. Serial
                        atlas of the marine environment, folio 22.. New York, NY: American Geograhic Society. pp. 8-13.

               Eleuterius, LN. 1987. Seagrass ecology along the coasts of Alabama, Louisiana, and Mississippi. Florida Marine
                        Research Publications, No. 42. pp. 11-24.

               Energy Resources Company. 1982. Ixtoc oil spill assessment, final report prepared for the Bureau of Land
                        Management, contract No. AA851-CTO-71. Cambridge, MA. ERCO/Energy Resources Co., Inc.,
                        Environmental Sciences Division; 3 vols. Available from NTIS, Springfield, VA.- Vol. I -
                        PB82-197781; Vol. 2 - PB82-197799; and Vol. 3 - PB82-1977783.

               ERCE. 1991. Onshore disposal of offshore drilling waste: Capacity and cost of onshore disposal facilities.
                        Prepared for the U.S. Environmental Protection Agency, Industrial Technology Division, Washington,
                        DC. Unpublished report.

               Espey, Huston & Associates. 1990. Remote-sensing survey, diver verification and cultural resource assessment,
                        Port Mansfield entrance channel and vicinity, Willacy County, Texas. Prepared under Contract No.
                        DACW64-89-D-OW2 for the U.S. Dept. of the Army, Corps of Engineers, Galveston, TX

               Evans, D.R. and S.D. Rice. 1974. Effects of oil on marine ecosystems: a review for administrators and policy
                        makers. Fishery Bull. 72(3):625-637.

               Exxon. 1979. Oil spill cleanup manual. Volume II, response guidelines.

               Falk, M.R. and M.J. Lawrence. 1973. Seismic exploration: its nature and effects on fish. Winnipeg, Manitoba,
                        Canada: Dept. of the Environment, Fisheries and Marine Service, Fisheries Operations Directorate,
                        Central Region. Technical Report Series, No. CEN T-73-9. 51 pp.

               Faulkner, D. and R. Chesher. 1979. Living corals. New York, NY: Clarkson N. Potter. 310 pp.

               Federal Fisheries News Bulletin. 1989a. Reduction of open area of Tortugas shrimp sanctuary. St.
                        Petersburg, FL: National Marine Fisheries. August 89-25. 1.

               Federal Fisheries News Bulletin. 1989b. Sharks to come under management in U.S. Atlantic ocean waters.
                        St. Petersburg, FL. National Marine Fisheries. October 89-32. 1.








                VI-14.

                Fiest, D.L. and P.D. Boehm. 1980. Subsurface distributions of petroleum from an offshore w,.U blowout - the
                        Ixtoc 1 blowout, Bay of Campeche. In: Proceedings of a symposium on preliminary results from the
                        September 1979 Researcher/Pierce Ixtoc-1 cruise, Key Biscayne, FL, June 9-10, 1980. Boulder, CO.
                        U.S. Dept. of Commerce, National Oceanic and Atmospheric Admin. pp. 169-180.

                Fischel, M., W. Grip, and I.A_ Mendelssohn. 1989. Study to determine the recovery of a Louisiana marsh
                        from an oil spill. In: Proceedings, 1989 oil spill conference ... February 13-16, 1989, San Antonio,
                        TX Washington, DC: American Petroleum Institute.

                Fleury, M.G.R. 1983. Outer continental shelf oil and gas blowouts: 179-1982. U.S. Geologiml Survey Open
                        File Report 83-562. 27 pp.

                Flint, R.W. and N.N. Rabalais, eds. 1980. Environmental studies South Texas outer continental shelf, 1975-
                        1977, submitted to the Bureau of Land Management ... Contract No. AA551-CT8-5-1. Port Aransas,
                        TX University of Texas, Marine Science Institute; 3 vols. Available from NTIS, Springfield, VA_
                        Vol. 1, PB80-181506; Vol. 2, PB80-181514; and Vol. 3, PB80-181522.

                Florida Dept of Environmental Regulation. 1987. Air quality report Division of Air ResourcBs Management

                Freeman, K 1991. Tracking the gentle giants. WorkBoat. 48(5/6):28-30.

                Freeman, R.L., S.M. Holland, and R.B. Ditton. 1985. Measuring the impact of the Ixtoc I oil spill on
                        visitation at three Texas public parks. CZM Journal, 13(2):177-200.

                Fritts, T.H. and M.A. McGehee. 1981. Effects of petroleum on the development and survival of marine turtle
                        embryos. Belle Chasse, LA.- U.S. Fish and Wildlife Service, Denver Wildlife Research Center.

                Fritts, T.H. and M.A- McGehee. 1982. Effects of petroleum on the development and survival of marine turtle
                        embryos. Prepared for the Minerals Management Service, Gulf of Mexico OCS Region under
                        Contract No. 14-16-0009-80-946.

                Fritts, T.H., A.B. Irvine, R.D. Jennings, L.A_ Collum, W. Hoffman, and M.A. McGehee. 1983. Turtles, birds,
                        and mammals in the northern Gulf of Mexico and nearby Atlantic waters. U.S. Fish and Wildlife
                        Service, Division of Biological Services, Washington, DC. FWS/OBS-82/65. 455 pp.

                Gainesville Sun. 1983. Outdoors Section. March 25, 1983.

                Gales, R.S. 1982. Effects of noise of offshore oil and gas operations on marine mammals - an introductory
                        assessment. Technical Report 844. Naval Ocean Systems Center, San Diego, CA.

                Gallaway, B.J. 1980. Environmental assessment of Buccaneer gas and oil field in the northwestern Gulf of
                        Mexico, 1975-1980. Vol. II Fishes and macrocrustaceans/biofouling communities. Galveston, TX
                        U.S. Dept. of Commerce, National Marine Fisheries Service; 115 pp. NTIS microfiche PB81-1883-4.

                Gallaway, B.J. 1981. An ecosystem analysis of oil and gas development on the Texas-Louisiana continental
                        shelf, FWS/OBS-81/27. Washington, DC: U.S. Fish and Wildlife Service, Office of Biological Services.
                        89 pp.

                Gallaway, B.J. and G.S. Lewbel. 1982. The ecology of petroleum platforms in the northwestern Gulf of Mexico:
                        a community profile. U.S. Dept. of the Interior, Fish and Wildlife Service (Report FWS/OBS 82/27)
                        and Bureau of Land Management, Gulf of Mexico OCS Region (Open File Report 82-03). New
                        Orleans, LA











                                                                                                                           VI-15

                Gallaway, B.J., M.F. Johnson, F.J. Margraff, R.L. Howard, L.R. Martin, G.L. Lewbel, and G.S. Boland. 1981.
                        The artificial reef studies: volume 11. In: Bedinger, CA, Jr. Ecological investigations of petroleum
                        production platforms in the Central Gulf of Mexico. Submitted to the BLM, Contract No.
                        AA551-CT8-17. San Antonio, TX Southwest Research Institute. 199 pp. Available from NTIS,
                        Springfield, VA. PB82-167826.

                Garrison, E.G., C.P. Giammona, F.J. Kelly, A.R. Tripp, and G.A. Wolff. 1989. Historic shipwrecks and
                        magnetic anomalies of the northern Gulf of Mexico: reevaluation of archaeological resource
                        management zone 1. U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS
                        Region, New Orleans, LA. 3 vols. OCS Study MMS 894X)23, 89-0024, and 89-0025.

                Geochernical and Environmental Research Group. 1988. Analyses of bivalves and sediments for organic
                        chemicals and trace elements from Gulf of Mexico estuaries. Second annual report to the U.S. Dept.
                        of Commerce, National Oceanic and Atmospheric Administration, Status and Trends Mussel Watch
                        Program. Geochemical and Environmental Research Group, Dept. of Oceanography, Texas A&M
                        University, College Station, TX

                Geraci, J.R. and D.J. St. Aubin. 1982. Study of the effects of oil on cetaceans. Final report prepared for the
                        U.S. Dept. of the Interior, Bureau of Land Managcmcnt, New York OCS Office, July 20, 1982. 274
                        PP.

                Geraci, J.R. and D.J. St. Aubin. 1988. Synthesis of the effects of oil on marine mammals. Washington, DC:
                        U.S. Dept. of the Interior, Minerals Management Service. OCS Study MMS 88-0049.

                Getter, C.D. and B.J. Baca. 1984. A laboratory approach for determining the effects of oils and dispersants
                        on mangroves. In: Allen, T.E., ed. Oil spill chemical dispersants: research, experience, and
                        recommendations, STP 840. Philadelphia, PA. American Society for Testing and Materials. pp. 5-13.

                Getter, C.D. and T.G. Ballou. 1985. Field experiments on the effects of oil and dispersants on mangroves.
                        In: Proceedings, 1985 oil spill conference, February 25-28, 1985, Los Angeles, CA. Washington, DC-
                        American Petroleum Institute. pp. 577-582.

                Geyer, R.A. 1980. Marine environmental pollution,, 1. Hydrocarbons. New York, NY. Elsevier Scientific
                        Publishing Co.

                Geyer, R.A. 1981. Naturally occurring hydrocarbons in the Gulf of Mexico and the Caribbean. In:
                        Proceedings, 1981 oil spill conference. . March 2-5, 1981, Atlanta, GA. Washington, DC- American
                        Petroleum Institute; pp. 445-451.

                Gill, S.D., R.H. Goodman, and J. Swiss. 1985. Halifax '83 sea trial of oil dispersant concentrates. pp. 479-482.
                        In: Proceedings of the 1985 Oil Spill Conference, American Petroleum Institute, Washington, DC. 651
                        PP.

                Godcharles, M.F. and M.D. Murphy. 1986. Species profiles: life histories and environmental requirements of
                        coastal fishes and invertebrates (south Florida)--king mackerel and Spanish mackerel. Fish and Wildlife
                        ,Service Biological Report 82(11.58). U.S. Army Corps of Engineers, TR EL-824. 18 pp.

                Godish, T. 1991. Air quality. 2nd ed. Michigan: Lewis Publishers, Inc. 422 pp.










                VI-16

                Goodale, D.R., M.A. Hyman, and H.E. Winn. 1981. Cetacean responses in association with the Regal Sword
                         oil spill. In: A characterization of mature mammals and turtles in the Mid- and North-Atlantic areas
                         of the U.S. Outer Continental Shelf, annual report for 1979. University of Rhode Island. Washington,
                         DC: U.S. Dept. of the Interior, Bureau of Land Management.

                Gordon, W.R., Jr. 1987. Rigs-to-Reefs selection criteria: what attracts Louisiana offshore recreational fishermen
                         to petroleum structures. In: U.S. Dept of the Interior, Minerals Management Service. 1990.
                         Proceedings: Seventh Annual Gulf of Mexico information transfer meeting. Sponsored by Minerals
                         Management Service, Gulf of Mexico OCS Region, November 4-6,1986, New Orleans, LA. OCS Study
                         MMS 87-0058. pp. 331-334.

                Gosselink, J.G., C.L. Cordes, and J.W. Parsons. 1979. An ecological characterization study of the Chenier
                         Plain coastal ecosystem of Louisiana and Texas, Vol. 1: Narrative report. FWS/013S-78/9. Slidell,
                         IA- U.S. Fish and Wildlife Service, Office of Biological Services. 302 pp.

                Gramling, R. 1984. OCS activities and their relationship to occupational shifts in the coastal zone parishes.
                         In: Gramling, R. and S. Brabant. The role of outer continental shelf oil and gas activities in the
                         growth and modification of Louisiana's coastal zone. Grant No. NA-83-AA-D-CZ025. U.S. Dept. of
                         Commerce, National Oceanic and Atmospheric Administration. pp. 103-116.

                Gramling, B. and S. Brabant 1986. Boomtowns and offshore energy impact assessment. Sociological
                         Perspectives 29(2):177-201.

                Gramling, R. and W.R. Freudenburg. 1990. A closer look at "local control": communities, commodities, and
                         the collapse of the coast. Rural Sociology 55:541-558.

                Grimes, C. 1988. Aggregation of icthyoplankton about the Mississippi River plume front: potential
                         importance of the plume to recruitment. In: Proceeding; Ninth annual Gulf of Mexico informational
                         transfer meeting. Sponsored by Minerals Management Service, Gulf of Mexico OCSRegion, October
                         25-27, 1988. New Orleans, LA. OCS Study MMS 89-0060- pp. 130-134.

                Groat, C.G. 1984. Personal communication. Louisiana Geological Survey. Dept. of Natural Resources.
                         October 22, 1984.

                Gruber, J.A. 1981. Ecology of the Atlantic bottlenosed dolphin (74niops truncatus) in the Pass Cavallo, Area
                         of Matagorda Bay, TX M.Sc. Thesis, Texas A&M University. 182 pp.

                Guillot, J. 1980. Masters of the marsh: an introduction to the ethnography of the Islenos of lower St. Bernard
                         Parish, Louisiana.

                Gulf Fishery News. 1989. Shark managment becomes high priority. Tampa, FL: Gulf of' Mexico Fishery
                         Managment Council. February/March 9(2) 1.

                Gulf of Mexico Fishery Management Council. 1985. Final amendment I Fishery management plan and
                         environmental impact statement for coastal migratory pelagic resources in the Gulf of Mexico and
                         South Atlantic Region. Tampa, FL. 135 pp.

                Gulf of Mexico Fishery Management Council. 1989. Amendment number 1 to the ireef fish fishery
                         management plan: includes environmental assessment, regulatory impact review,, and regulatory
                         flexibility analysis. Tampa, FL. 177 pp.











                                                                                                                          VI-17

               Gulf of Mexico Fishery Management Council. 1990. Public hearing comments on the proposed amendment to
                        the Gulfof Mexico Reef Fish Management Plan. New Orleans, LA_

               Gulf States Marine Fisheries Commission. 1988. Thirty-eighth annual report (1986-1987) to the Congress of
                        the United States and to the governors and legislators of Alabama, Florida, Louisiana, Mississippi, and
                        Texas. Ocean Springs, MS. 90 pp.

               Guzman, H.M. and J.B.C. Jackson. 1991. Subtidal reef corals. pp. 121-151. In: Keller, B.D. and J.B.C. Jackson,
                        eds. Long-term assessment of the oil spill at Bahia Las Minas, Panama, interim report, volume II:
                        technical reporL U.S. Dept of the Interior, Minerals Management Service, Gulf of Mexico OCS
                        Regional Office, New Orleans, 1A OCS Study MMS 90-0031. 450 pp.

               Guzman, H.M., J.B.C. Jackson, and E. Weil. 1991. Short-term ecological consequences of a major oil spill on
                        Panamanian subtidal reef corals. Coral Reefs 10:1-12.


               Hall, R. 1990. Environmental consequences of mismanagement of wastes from oil and gas exploration,
                        development, and production. In: Proceedings of the First International Symposium on Oil and Gas
                        Exploration and Production Waste Management Practices. U.S. Environmental Protection Agency. pp.
                        387-402.


               Hallowell, C. 1979. People of the bayou: Cajun life in lost Louisiana. New York, NY E.P. Dutton Press.
                        141pp.

               Hamilton, P., J. Singer, R. Wayland, and E. Waddel. 1989. The Loop Current and warm eddies in the Central
                        and Eastern Gulf. Chapman Conference on the Physics of the Gulf of Mexico, Florida.

               Haney, J.L, S.G. Douglas, LA_ Gardner, and C.S. Burton. 1990. Application of the urban airshed model in
                        the Baton Rouge seven-parish study area. Systems Applications, Inc. in Air & Waste Management
                        Annual Meeting, Pittsburgh, PA.

               Hanley,  P. 1984. Briefing material on geophysical research of the U.S.A. outer continental shelf. Texas
                        Instruments Inc. and GSI International Operations. TI-13032. 11 pp.

               Harper, D.E. 1986. A review and synthesis of unpublished and obscure published literature concerning
                        produced water fate and effects. Prepared for the Offshore Operators Committee, Environmental
                        Science Task Force (Chairman, R.C. Ayers, Exxon Production Research Co., Houston, TX).

               Harrison, P. 1983. Seabirds: an identification guide. Houghton Mifflin Co. 448 pp.

               Hayman, P., J. Marchant, and T. Prater. 1986. Shorebirds: an identification guide to the waders of the world.
                        Houghton Mifflin Co. 412 pp.

               Heaton, M.G., R.J. Wilke, and M.J. Bowman. 1980. Formation of tar balls in a simulated oceanic front.
                        Texas Jour. Sci. 32(3).

               Hecker, B. 1985. Fauna from a cold sulfur-seep in the Gulf of Mexico: comparison with hydrothermal vent
                        communities and evolutionary implications. Biol. Soc. Wash. Bull. 6:465-473.

               Hedges, J.I. and P.L. Parker. 1976. Land-derived organic matter in surface sediments from the Gulf of Mexico.
                        Geochemica et Cosmochimica Acta 40:1019-1029.










                  VI-18

                  Helicopter Safety Advisory Conference. 1991. Sensitive area booklet and maps: resolving issues involving flight
                          in sensitive environmental areas. 21 pp.

                  Heneman, B. and the Center for Environmental Education. 1988. Persistent marine debris in the North Sea,
                          northwest Atlantic Ocean, wider Caribbean area, and the west coast of Baja California. A report to
                          the Marine Mammal Commission and the National Ocean Pollution Program Office, NOAA/DOC.
                          Contract MM3309598-5. Washington, DC. Chapter V. 36 pp.

                  Herbert, B. 1991. Personal communication. Chairman, Waste Handling and Recycling Subcommittee, Offshore
                          Operators Committee.

                  Hildebrand, H.H. 1982. A historical review of the status of sea turtle populations in the western Gulf of
                          Mexico. In: Bjorndal, KA, ed. Biology and conservation of sea turtles. Proc. World Conf. Sea
                          Turtle Conserv. November 26-30, 1979. Smithsonian Institution Press. Washington, DC. 583 pp.

                  Hoi-Chow, L. and F. Mcow-Chan. 1985. Field and laboratory studies on the toxicitics of oils to mangroves. In:
                          Proceedings, 1985 oil spill conference, February 25-28, 1985, Los Angeles, CA. Washington, DC:
                          American Petroleum Institute. pp. 539-596.

                  Hopkins, T.S., D.R. Blizzard, and D.K Gilbert. 1977. The molluscan fauna of the Florida Middle Ground with
                          comments on its zoogeographical affinities. Northeast Gulf Sci. 1:39-47.

                  Horst, J. 1989. Black drum. Baton Rouge, LA_ Louisiana Cooperative Extension Service. Sea Grant
                          Program Lagniappe. September 13(9):1.

                  Hsu, S.A. 1979. An operational forecasting model for the variation of mean maximum mixing heights across
                          the coastal zone. Boundary-layer Meteorology, 16:93-98.

                  Hudson, J.H., E.A_ Shinn, and D.M. Robbin. 1982. Effects of offshore oil drilling on Philippine reef corals.
                          Bull. Mar. Sci. 32:890-908.


                  Hubbard, J.A.E.B. 1974. Scleractinian coral behavior in calibrated current experiments: an index to their
                          distribution patterns. Proc. 2nd. Int. Coral Reef Symp. Brisbane, Australia. 2:107-126.

                  Humm, H.J. 1973. The biological environment: seagrass. In: Jones, J.I., R.E. Ring, M.O. Rinkel, and R.E.
                          Smith, eds. A summary of knowledge of the eastern Gulf of Mexico. St. Petersburg, FL: State
                          University System of Florida, Institute of Oceanography (SUSIO). pp. IIIC1-IIIC10.

                  Hunt, G.L., Jr. and D.C. Schneider. 1987. Scale-dependent processes in the physical and biological environment
                          of marine birds. In: Croxall, J.P., ed. Seabirds: feeding ecology and role in marine ecosystems.
                          Cambridge University Press. pp. 7-42.

                  Ichiye, T., H. Kuo, and M. Carnes. 1973. Assessment of currents and hydrography of the eastern Gulf of
                          Mexico. Contribution number 601. College Station, TX Texas A&M University, Dept. of
                          Oceanography. 217 pp. in various pagings.

                  Intergovernmental Maritime Consultative Organization (IMCO) et al. 1969. Abstract of first session report
                          on joint group of experts on the scientific aspects of marine pollution. Water Res. 3:995-1005.

                  International Tanker Owners Pollution Federation, Ltd. 1982. Technical Information Paper: Use of oil spill
                          dispersants. pp. 1-8.











                                                                                                                       VI-19

               Irvine, A.B., M.D. Scott, R.S. Wells, and J.H. Kaufman. 1981. Movements and activities of the Atlantic
                       bottlenose dolphin, 71irsiops truncatus, near Sarasota, Florida. Fishery Bulletin (U.S.) 79.671-688.

               Iverson, R.L and T.L. Hopkins. 1981. A summary of knowledge of plankton production in the Gulf of Mexico:
                       recent phytoplankton and zooplankton research. In: Proceedings of a symposium on environmental
                       research needs in the Gulf of Mexico (GOMEX), Key Biscayne, FL, 30 September-5 October, 1979,
                       volume ILA- MiamL FL. U.S. Dept. of Commerce, National Oceanic and Atmospheric Admin.,
                       AOML pp. 147-211.

               Jaap, E.C. and P. Hallock. 1990. Reef ecosystems. In: Meyers, R.L and J.J. Ewel, eds. Ecosystems in Florida.
                       Orlanda, FL: University Central Florida Press. pp. 574-616.

               Jackson, C. 1991. Written communication. Statistics on all Gulf of Mexico claims filed under the Fishermen's
                       Contingency Fund for fiscal years 1990 and 1991. Silver Springs, MD: U.S. Dept of Commerce,
                       National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Financial
                       Services Division. 1 p.

               Jackson, J.B.C., J.D. Cubit, B.D. Keller, V. Batista, K. Burns, H.M. Caffey, R.L Caldwell, S.D. Garrity, C.D.
                       Getter, C. Gonzalez, H.M. Guzman, K.W. Kaufmann, A.H. Knap, S.C. Levings, M.J. Marshall, R.
                       Steger, R.C. Thompson, and E. Weil. 1989. Ecological effects of a major oil spill on Panamanian
                       coastal marine communities. Science 243:37-44.

               Jacobs Engineering Group Inc. 1989. Air quality impact of proposed OCS lease sale no. 95, final report.
                       Contract no. 14-12-OWl-30127.

               Jeffrey, LM. 1977. Progress report on bacterial degradation of oil and floating tar concentrations in the Gulf
                       of Mexico. College Station, TX Texas A&M University, Dept. of Oceanography, 40 pp.

               Jeffrey, LM., W.E. Pequegnat, E.A. Kennedy, A. Vos, and B.M. James. 1974. Pelagic tar in the Gulf of
                       Mexico and Caribbean Sea. In: Marine pollution monitoring (petroleum), proceedings of a
                       symposium and workshop held at the National Bureau of Standards, Galthersburg, MD, May 13-17,
                       1974. NBS special pub. 409. Washington, DC: U.S. Government Printing Office. 316 pp.

               Johnson, W.B. and J.G. Gosselink. 1982. Wetland loss directly associated with canal dredging in the Louisiana
                       coastal zone. In: Boesch, D.F., ed. Proceedings of the conference on coastal erosion and wetland
                       modification in Louisiana: causes, consequences, and options. Baton Rouge, LA. U.S. Dept. of the
                       Interior, Fish and Wildlife Service. FWS/OBS-82/59. pp. 60-72.

               Johnson, P.A., W.E. Westermeyer, and J.E. Mielke. 1990. Coping with an oiled sea. U.S. Congress, Office of
                       Technology Assessment. Washington, DC: Government Printing Office. Available as OTA-BP-M3.
                       70 pp.

               Jokiel, P.L. and S.L. Coles. 1977. Effects of temperature on the mortality and growth of Hawaiian reef corals.
                       Mar. Biol. 43:201-208.


               Jones, J. 1991. Personal communication. Energy Coating, Houston, TX

               Jordan, R. 1992. Personal communication. U.S. Environmental Protection Agency, Industrial Technology
                       Division, Washington, DC.










                 VI-20

                 Jordan, R.E. and J.R. Payne. 1980. Fate and weathering of petroleum spills in the marine environment. Ann
                         Arbor, MI: Ann Arbor Science. 174 pp.

                 Judd, F.W., R.I. Lonard, J.H. Everitt, and R. Villarreal. 1988. Effects of vehicular traffic in the secondary
                         dunes and vegetated flats of South Padre Island, Texas. Coastal Zone '89. Ameriain Society of Civil
                         Engineers, New York. 5 vols. pp. 4,634-4,645.

                 Kanwisher, J.W. and S.A. Wainwright. 1967. Oxygen balance in some reef corals. Biol. Bull. 133:378-390.

                 Kasoulides, G.C. 1988. Identification of the sources of discharged pollutants. Mar. Poll. Bull. 19(7):307-310.

                 Keller, B.D. and J.B.C. Jackson, eds. 1991. Long-term assessment of the oil spill at Bahia Las Minas, Panama,
                         interim report, volume II: technical report. U.S. Dept. of the Interior, Minerals Management Service,
                         Gulf of Mexico OCS Regional Office, New Orleans, LA. OCS Study MMS 90-0031. 450 pp.

                 Kennedy, V.S., ed. 1984. The estuary as a filter. Orlando, Fl- Academic Press.

                 Kennicutt, M.C., 11 and B. Gallaway. 1985. Recent discoveries of deep water communities in the northwestern
                         Gulf of Mexico. Abstract of presentation of contract No. 30212 at Minerals Management Service's
                         Information Transfer Meeting in New Orleans, I.A October 22-24, 1985.

                 Kennicutt, M.C. II, J.M. Brooks, R.R. Bidigare, and G.J. Denoux. 1988. Gulf of Mexico hydrocarbon seep
                         communities --- I. Regional distribution of hydrocarbon seepage and associated fauna. Deep-Sea
                         Research 35:1639-1651.


                 Kilgen, R.H. and R.J. Dugas. 1989. The ecology of oyster reefs of the northern Gulf of Mexico: an open file
                         report U.S. Fish and Wildlife Service, National Wetlands Research Center, Slidell, 1-k NWRC-open
                         file report 89-02. 113 pp.

                 Knap, A.H., S.C. Wyers, R.E. Dodge, T.D. Sleeter, H.R. Frith, S.R. Smith, and C.B. Cook. :1985. The effects
                         of chemically and physically dispersed oil on the brain coral Diploria strigosa (Dana) - a summary
                         review. In: Proceedings 1985 Oil Spill Conference, February 25-28, 1985, Los Angeles, Ck
                         Washington, DC: American Petroleum Institute. pp. 547-551.

                 Koski, W.R. and W.J. Richardson. 1976. Review of waterbird deterrent and dispersal systems for oil spills.
                         Prepared for the Petroleum Association for Conservation of the Canadian Environment. PACE
                         Report No. 76-6.

                 Kraemer, G.P. 1982. Population levels and growth rates of scleractinian corals within the Diploria-Montaslrea-
                         Poiites zones of the East and West Flower Garden Banks. M.S. Thesis. Department of Oceanography,
                         Texas A&M University, College Station, TX 139 pp.

                 Kraus, S. 1987. Personal communication. New England Aquarium.

                 Kushlan, J.A. 1978. Feeding ecology of wading birds. In: Sprunt, A., J.C. Odgen, and S. Winckler, eds. Wading
                         birds. Research report no. 7 of the National Audubon Society. pp. 248-298.

                 Lanfear, K.J. and D.E. Amstutz. 1983. A reexamination of occurrence rates for accidental oil spills on the
                         U.S. Outer Continental Shelf. presented at the Eighth Conference on the Prevention, Behavior,
                         Control, and Cleanup of Oil Spills. San Antonio, Texas; February 28-March 3, 1983.










                                                                                                                            VI-21

               Lang, J.C. 1973. Interspecific aggression by scleractinian corals. 11. Why the race is not only to the swift. Bun.
                        Mar. Sci. 23:260-279.


               Lange, R. 1985. A 100 ton experimental oil spill at Halten Bank, off Norway. In: Proceedings, 1985 Oil Spill
                        Conference, February 25-28,1985, Los Angeles, CA. Washington,DC: American Petroleum Institute.

               LaRock, P. and H.L. Bittaker. 1973. Chemical data of the estuarine and nearshore environments in the eastern
                        Gulf of Mexico. In: Jones, J.I., R.E. Ring, M.O. Rinkel, and R.E. Smith, eds. A summary of knowledge
                        of the eastern Gulf of Mexico. St. Petersburg, F1-- State University System of Florida, Institute of
                        Oceanography (SUSIO). pp.IIC8-IIC86.

               Laska, S. 1991. Personal communication. Director, Environmental Social Science Research Institute, University
                        of New Orleans, LA.

               Lazauski, H.G. 1990. Written communication. 1989 fishing license data. Alabama Dept. of Conservation and
                        Natural Resources, Marine Resources Division, computer data. 3 pp.

               LeBlanc, D.J. 1985. Environmental and construction techniques involved with the installation of a gas pipeline
                        across Timbalier Island, Louisiana. In: Proceedings, Sixth annual Gulf of Mexico information transfer
                        meeting. Sponsored by Minerals Management Service, Gulf of Mexico OCS Region, October 22-24,
                        1985. New Orleans, LA. OCS Study MMS 86-0073. pp. 203-205.

               Lee, W.Y., A. Morris, and D. Boatwright. 1980. Mexican off spill: a toxicity study of oil accommodated in
                        seawater on marine invertebrates. Mar. Poll. Bull. 11:231-234.


               LeGore, S., D.S. Marszalek, L. Danek, M.S. Tomlinson, J.E. Hoffman, and J.E. Cuddeback. 1989. Effect of
                        chemically dispersed oil on Arabian Gulf corals: a field experiment. pp. 375-380. In: Proceedings 1985
                        International Oil Spill Conference. American Petroleum Institute, Washington, DC. 587 pp.

               Lewis, J.B. and W.S Price. 1975. Feeding mechanisms and feeding strategies of Atlantic reef corals. J. Zool.
                        London 176:527-544.


               LGL Ecological Research Associates, Inc. and Texas A&M University. 1986. Gulf of Mexico continental slope
                        study, annual report: year 2. Prepared for the Minerals Management Service, Gulf of Mexico OCS
                        Region, Contract No. 14-12-"1-30212. 3 vols. OCS Study/MMS 86-ON9, 86-0090, and 86-0091.

               Lichtenthaler, R.G. and P.S. Daling. 1983. Dispersion of chemically treated crude oil in Norwegian offshore
                        waters. pp. 7-14. In: Proceedings of the 1983 Oil Spill Conference, American Petroleum Institute,
                        Washington, DC. 586 pp.

               Lichtenthaler, R.G. and P.S. Daling. 1985. Aerial application of dispersants - comparison of slick behavior of
                        chemically treated verses non treated slicks. pp. 471478. In: Proceedings of the 1985 On Spill
                        Conference, American Petroleum Institute, Washington, DC. 651 pp.

               Linden, 0., J.R. Sharp, R. Laughlin, Jr., and J.M. Neff. 1979. Interactive effects of salinity, temperature, and
                        chronic exposure to oil on the survival and development rate of embryos of the estuarine killfish
                        Fundulus heteroclitus. Mar. Biol. 51:101-109.

               Lindstedt, D.M. and J.C. Holmes, Jr. 1988. September sweep: Louisiana's 1987 beach cleanup. Prepared
                        under DNR Interagency Agreement No. 21912-88-15.










                VI-22

                Linton, T.L. 1988. Sociocconomics. In: Phillips, N.W. and B.M. James, eds. Offshore Texas and Louisiana
                         marine ecosystems data synthesis. Final report to the Minerals Management ServirA@, Gulf of Mexico
                         OCS Region, Contract No. 14-12-"1-30380. Vol. 11, pp. 339-364 and Vol. III, pp. 457-529.

                Lohoefener, R. 1989. Personnal communication. National Marine Fisheries Service, Pascagoula, MS.

                LA)hoefener, R., W. Hoggard, K Mullin, C. Roden, and C. Rogers. 1990. Association of sea turtles with
                         petroleum platforms in the north-central Gulf of Mexico. U.S. Dept. of the Interior, Minerals
                         Management Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study MMS 90-0025. 90
                         pp-

                Long, B.F., J.H. Vandermeulen, and T.P. Ahern. 1981. The evolution of stranded oil within sandy beaches.
                         In: Proceedings, 1981 oil spill conference, March 2-5,1981, Atlanta, GA. Washingtoii,DC. American
                         Petroleum Institute. pp. 519-524.

                Longwefl,A.C. 1977. A genetic look at fish eggs and oil. Oceanus. 20(4):46-58.

                Louisiana Dept. of Enviromental Quality. 1988. State of Louisiana: Nonpoint source pollution assessment
                         report (draft). August 30, 1988.

                Louisiana Dept. of Environmental Quality. 1989. Ambient air quality data annual report Metairie, LA. 94 pp.

                Louisiana Dept. of Environmental Quality. 1990. Produced water radium data compiled as part of the
                         Emergency Rule, February 20, 1989. Unpublished data.

                Louisiana Geological Survey. 1985. SHORE LINES Coastal Protection Newsletter. December 1985. Baton
                         Rouge, LA.

                Louisiana Geological Survey. 1986. SHORE LINES Coastal Protection Newsletter. January 1986. Baton Rouge,
                         1A

                Lowery, G.H. 1974. The mammals of Louisiana and its adjacent waters. Baton Rouge, LA.- Louisiana State
                         University Press. 565 pp.

                Loya, Y. and B. Rinkevich. 1980. Effects of oil pollution on coral reef communities. Mar. Ecol. Progr. Ser.
                         3:167-180.


                Ludwick, J.C. and W.R. Walton. 1957. Shelf-edge, calcareous prominences in the norfllwestern Gulf of
                         Mexico. In: Bulletin of the American Association of Petroleum Geologists (September 1957).
                         41:9(2054-2101).

                Lutz, P. 1989. Methods for determining the toxicity of oil and dispersants to sea turtles. In: Oil and
                         dispersant toxicity testing: proceedings of a workshop on technical specifications, January 17-19, 1989,
                         New Orleans, LA. Prepared by Technical Resources Inc. under Contract No. 14-1.7--OWl-30447.

                Lyons, T.J. and W.D. Scott. 1990. Principles of air pollution meteorology. Boca Raton, FL: CRC Press, Inc.
                         225 pp.

                Lytle, J.S. 1975. Fate and effects of crude oil on an estuarine pond. Proceedings of the conference on
                         prevention and control of oil pollution. San Francisco. pp. 595-600.











                                                                                                                          VI-23

                 MacDonald, I.R., G.S. Boland, J.S. Baker, J.M. Brooks, M.C. Kennicutt II, and R.R. Bidigare. 1989. Gulf of
                         Mexico hydrocarbon seep communities. Mar. Biol. 101:235-247.

                 Mack, D. and N. Duplaix. 1979. The sea turtle: an animal of divisible parts. International trade in sea turtle
                         products. Presented at the World Conference on Sea Turtle Conservation, 1979. Washington, D.C.
                         86 pp.

                 Mackin, J.G. 1973. A review of significant papers on effects of oil spills and off field brine discharges on
                         marine biotic communities. Texas A&M Research Foundation Project 737. College Station, TX pp.
                         4-8.


                 Madge, S. and H. Burn. 1988. Waterfowl: an identification guide to the ducks, geese, and swans of the world.
                         Houghton Mifflin Co. 298 pp.

                 Mager, A. and R. Ruebsamen. 1988. National Marine Fisheries Service habitat conservation efforts in the
                         coastal southeastern United States. Mar. Fish. Rev. 50(3):43-50.

                 Malins, D.C., S. Chan, H.O. Hodgins, U. Varanasi, D.D. Weber, and D.W. Brown. 1982. The nature and
                         biological effects of weathered petroleum. Environmental Conservation Division, Northwest and
                         Alaska Fisheries Conter, National Marine Fisheries Service, Seattle. 43 pp.

                 Malme, C.L., P.R. Miles, C-W, Clark, P. Tyack, and J.E Bird. 1984. Investigations of the potential effects of
                         underwater noise from petroleum industry activities on migrating gray whale behavior. Contract No.
                         14-12-"2-29033. Anchorage, AK- U.S. Dept. of the Interior, Minerals Management Service.

                 Marine Environmental Sciences Consortium. 1981. Transportation of oil and gas in the coastal area of the
                         State of Alabama: emphasis on the location of pipelines. South Alabama Regional Planning
                         Commission: Mobile, AL. 14 pp.

                 Marine Industry Group. 1991. Oil spill response resource and logistics directory.

                 Martin, R.P. 1990. Written communication. 1990 survey of brown pelican rookeries along coastal Louisiana.
                         Louisiana Natural Heritage. Unpublished data. I p.

                 Martin, P.A., Jackson, and W.E. Galloway. 1984. Structural and depositional styles of Gulf Coast Tertiary
                         continental margins: applicaion to hydrocarbon exploration. Continuing education course note series
                         no. 25. pp. 29-31.

                 McAuliffe, C.D., A.E. Smalley, R.D. Groover, W.M. Welsh, W.S. Pickle, and G.E. Jones. 1975. Chevron
                         Main Pass Block 41 oil spill: chemical and biological investigation. In: Proceedings 1975 Conference
                         on Prevention and Control of Oil Pollution, March 25-27, 1975, San Francisco, CA. Washington, DC:
                         American Petroleum Institute.

                 McAuliffe, C.D., B.L. Steelman, W.R. Leek, D.F. Fitzgerald, J.P. Ray, and C.D. Barker. 1981. The 1979
                         southern California dispersant treated research oil spills. In: Proceedings 1981 Oil Spill Conference,
                         March 2-5, 1981, Atlanta, GA. Washington, DC: American Petroleum Institute. pp. 269-282.

                 McCarthy, C. 1989. Personal communication, Louisiana Dept. of Natural Resources, Office of Conservation,
                         Dept. of Enforcement.










               VI-24

               McGrail, D.W., D. Huff, and S. Jenkins. 1978. Current measurements and dye diffusion studies. In:
                        Northwestern Gulf of Mexico topographic features study-, final report to the Bureau of Land
                        Management, Contract No. AA550-CT7-15. College Station, TX Texas A&M University. pp. 111-3
                        to 111-7.

               McGowen, J.C., C.G. Groat, L.F. Brown, W.L. Fisher, and A.J. Scott. 1970. Effects of Hurrimne "Celia" - a
                        focus on environmental geology problems of the Texas coastal zone. Geol. Circ. 761-3. Austin, TX
                        University of Texas. 35 pp.

               Mendelssohn, I.A. and M.W. Hester. 1988. Texaco USA.- coastal vegeta       tion project, Timbalier Island. New
                        Orleans, LA. Texaco USA. 207 pp.

               Mendelssohn, I.A., M.W. Hester, C. Sausser, and M. Fishel. 1990. The effect of a Louisiana cr-uide oil discharge
                        from a piepline break on the vegetation of a southeast Louisiana brackish marsh. Oil and Chemical
                        Pollution 7(1990):1-15.

               Menzie, C.A. 1982. The environmental implications of offshore oil and gas activities. Environ. Sci. Technol.
                        16(8):454A-472A.

               Menzie, C.A. 1983. Diminishment of recruitment: a hypothesis concerning impacts on benthic communities.
                        Mar. Poll. Bull.

               Middleditch, B.S., ed. 1981. Environmental effects of offshore oil production, the Buccaneer gas and oil field
                        study. New York and London: Plenum Press.

               Mors, T.A., R.G. Rolan, and S.E. Roth. 1982. Interim final assessment of environmental fate and effects of
                        discharges from offshore oil and gas operations. Prepared by Dalton, Dalton, and :,14ewport for the
                        U.S. Environmental Protection Agency; Washington, DC.

               Morton, R.A. 1982. Effects of coastal structures on shoreline stabilization and land loss - the Texas
                        experience. In: Boesch, D.F., ed. Proceedings of the conference on coastal erosion and wetland
                        modification in Louisiana: causes, consequences, and options. Washington, DC: U.S. Fish and
                        Wildlife Service, Biological Services Program. FWS/OBS-82/59.

               Mueller, A.J. and C.H. Mendoza. 1983. The Port Bolivar, Texas, oil spfll--a case history of oi[ed bird survival.
                        In: Proceedings, 1983 oil spill conference, February 28-March 3,1983, San Antonio,'IX Washington,
                        DC: American Petroleum Institute. pp.521-523.

               Mulino, M. and M. Rayle. 1992. Produced water radionuclides fate and effects. Steimle and Associates, Inc.,
                        Metairie, LA- In: Proceedings, International Produced Water Symposium, San Diego, Ck In press.

               Muncy, R.J. 1984. Species profiles: life histories and environmental requirements of coastal fishes and
                        invertebrates (south Atlantic) -- white shrimp. U.S. Dept. of the Interior, Fish and Wildlife Service
                        (FWS/OBS-82/11.27) and U.S. Army Corps of Engineers, Coastal Ecology Group, Waterways
                        Experiment Station (TR EL-824). 19 pp.

               Nakassis, A. 1982. Has offshore oil production become safer? U.S. Geological Survey Open File Report
                        82-232. Reston, VA. U.S. Geological Survey. 27 pp.

               National Geographic Society. 1983a. Field guide to the birds of North America. The National Geographic
                        Society, Washington, DC. 464 pp.











                                                                                                                           VI-25

               National Geographic Society. 1985b. Bird migration in the Americas (map). The National Geographic
                        Society, Cartographic Division. Washington, DC.

               National Research Council (NRC). 1983. Drilling discharges in the marine environment. Panel on
                        Assessment of Fates and Effects of Drilling Fluids and Cuttings in the Marine Environment. Marine
                        Board; Commission on Engineering and Technical Systems; National Research Council. Washington,
                        DC. National Academy Press.

               National Research Council (NRC). 1985. Oil in the sea: inputs, fates, and effects. Washington, DC:
                        National Academy Press. 601 pp.

               National Research Council (NRC). 1989. Using oil spill dispersants on the sea. Washington, DC.- National
                        Academy Press. 355 pp.

               National Research Council (NRC). 1990. The decline of sea turtles: causes and prevention. Committee on
                        Sea Turtle Conservation. Washington, DC: National Academy Press. 183 pp.

               Neff, J.M. 1981. Fate and biological effects of oil well drilling fluids in the marine environment; a literature
                        review. Final technical report No. 15077 to the U.S. Environmental Protection Agency. Gulf Breeze,
                        FL.- U.S. Environmental Protection Agency, Environmental Research Laboratory.

               Neff, J.M., J.W. Anderson, B.A. Cox, R.B. Laughlin, Jr., S.S. Rossi, and H.E. Tatem. 1976. Effects of
                        petroleum on survival, respiration and growth of marine animals. In: Sources, effects, and sinks of
                        hydrocarbons in the aquatic environment. Washington, DC- American Institute of Biological Sciences.
                        pp. 515-540.

               Neff, J.M., T.C. Sauer, and N. Maciolek. 1989. Fate and effects of produced water discharges in nearshore
                        marine waters. Prepared for the American Petroleum Institute, Washington, DC.

               Nelson, D.A. 1988. Life history and environmental requirements of loggerhead turtles. U.S. Fish and Wildlife
                        Service Biological Report 88(23) TREL-86-2 (rev.).

               Nelson, W.R. and D.W. Ahrenholz. 1986, Population and fishery characteristics of Gulf menhaden, Brevoortia
                        patronus. Fishery Bulletin 84(2):311-325.

               NERBC (New England River Basins Commission). 1976. Factbook. In: Onshore facilities related to offshore
                        oil and gas development. Boston, MA.

               Nichols, J. 1990. Personal communication, Meeting regarding threatened and endangered species on the
                        Chandeleur and Breton Islands, 1A August 30, 1990. Slidell, LA.

               Nichols, J.A. and H.D. Parker. 1985. Dispersants. Comparison of laboratory and field trials with practical
                        experience at spills. pp. 421-427. In: Proceedings of the 1985 Oil Spill Conference, American
                        Petroleum Institute, Washington, DC. 651 pp.

               NPA Data Services, Inc. 1991. Key indicators of county growth, 1970-2010.1991 edition, Washington, DC: NPA
                        Data Services, Inc.

               Nowlin, W.D., Jr. 1972. Winter circulation patterns and property distributions. In: Capurro, I-R.A. and
                        Reid, J.L., eds. Contributions on the physical oceanography of the Gulf of Mexico. Vol. 2, Texas
                        A&M University oceanographic studies. Houston, TX Gulf Pub. Co. p. 3.










               VI-26


               Offshore Operators Committee. 1991. Unpublished data presented at the MMS/OOC NORM meeting, August
                        20,1991.

               The Offshore International Newsletter. 1991. Offshore Data Services. 1(1). July 1, 1991.

               Ogden, J.C. 1978. Recent population trends of colonial wading birds on the Atlantic and Gulf coastal plains.
                        In: Sprunt A., IV, J.C. Ogden, and S. Winckler, eds. Wading birds. National Audubon Society, New
                        York, NY. pp. 137-154.

               Ogren, L., F. Berry, K Bjorndal, H. Kumpf, R. Mast, G. Medina, H. Reichart, and R. Witham. (compilers).
                        1.989. Proceedings of the second Western Atlantic turtle symposium, October 12-16, 1987, Mayaguez,
                        Puerto Rico. Panama City, FL. U.S. Dept of Commerce, National Oceanic and Atmospheric
                        Administration. NOAA Technical Memorandum NMFS SEFC-226.


               Oil and Gas Journal. 1991. Baker-Hughes rig count. 89(43):104 pp. (October 28, 1991).

               Oil Spill Intelligence Report 1982. Overview- The international oil spill organization (May 21, 1982).

               Oil Spill Intelligence Report. 1984a. Booms. Vol. VII, No. 45 (November 16, 1984).

               Oil Spill Intelligence Report. 1984b. Skimmers. Vol. VII, No. 50 (December 21, 1984).

               Oil Spill Intelligence Report. 1984c. New sorbent products. Vol. VII, No. 13 (April 13, 19,84).

               Oil Spill Intelligence Report. 1988. USCG proposes to apply oil pollution prevention rules to Hazmat
                        Transfers. Vol. XI, No. 25 (June 20, 1988).

               Oil Spill Intelligence Report 1991. Notable spills in 1990. Vol. XIV, No. 1 (January 3, 1991).

               O'Keeffe, D.J. and G.A_ Young. 1984. Handbook on the environmental effects of underwater explosives.
                        NSWC TR 83-240. Naval Surface Weapons Center. Dahlgren, VA., and Silver Springs, MD.

               Olds, W.T., Jr. 1984. In: U.S., Congress, House, Committee on Merchant Marine Fisheries, Offshore Oil and
                        Gas Activity and Its Socioeconomic and Environmental Influences, 98th Cong., 2d sess., 1984, pp. 54-
                        55.

               Osborne, N. 1991. Personal communication. Vice-President, Petroleum Helicopters, Inc.

               Osburn, H.R., M.F. Osborn, and H.R. Maddux. 1988. Trends in finfish landings by sport-boat fishermen in
                        Texas marine waters, May 1974-May 1987. Texas Parks and Wildlife Dept., Austin, TX

               Otvos, E.G. 1979. Barrier island evolution and history of migration: north central Gulf coast. In: Leatherman,
                        S., ed. Barrier islands from the Gulf of St. Lawrence to the Gulf of Mexico. New York, NY:
                        Academic Press. pp. 219-319.

               Parker, M. 1990. Personal communication. Exxon, New Orleans, LA

               Parker, R.D., Morrison, J.M., and Nowlin, W.D. Jr. 1979. Surface drifter data from the Caribbean Sea and
                        Gulf of Mexico, 1975-1978. Dept. of Oceanography, Texas A&M Univ., Reference 79-8-T, 157 pp.











                                                                                                                       VI-27

              Paull, C.K, B. Hecker, R. Commeau, R.P. Freeman-Lynde, C. Neumann, W.P. Corso, S. Golubic, J.E. Hook,
                       E. Sikes, and J. Curray. 1984. Biological communities at the Florida Escarpment resemble
                       hydrothermal vent taxa. Science 226:965-967.

              Paull, C.K, A-J.T. Jull, L.J. Toolin, and T. Linick. 1985. Stable isotope evidence for chemosynthesis in an
                       abyssal seep community. Nature 317:709-711.

              Peakall, D.P., J. Tremblay, W.B. Kinter, and D.S. Miller. 1981. Endocrine dysfunction in seabirds caused by
                       ingested oil. Environmental Research, 24:6-14.

              Penland, S. and R. Boyd. 1982. Assessment of geological and human factors responsible for Louisiana coastal
                       barrier erosion. In: Boesch, D.F., ed. Proceedings of the conference on coastal erosion and wetland
                       modification in Louisiana: causes, consequences, and options. Washington, DC. U.S. Fish and
                       Wildlife Service, Biological Services Program. FWS/OBS-82/59. pp. 14-38.

              Penland, S. and R. Boyd, eds. 1985. Transgressive depositional environments of the Mississippi River delta
                       plain. Baton Rouge, LA. Louisiana Geological Survey. 233 pp.

              Pequegnat, W.E. 1983. The ecological communities of the continental slope and adjacent regimes of the
                       northern Gulf of Mexico. Final report to MMS (Contract No. AA851-CTI-12).

              Perret, W.S., J.E. Weaver, R.O. Williams, P.L Johansen, T.D. McIlwain, R.C. Raulerson, and W.M. Tatum.
                       1980. Fishery profiles of red drum and spotted seatrout. April 1980, No. 6. Gulf States Marine
                       Fisheries Commission. 60 pp.

              Peterson, J.H. 1987. Current research on Gulf Coast Indians. Proceedings: eighth annual Gulf of Mexico
                       information transfer meeting. Sponsored by Minerals Management Service, Gulf of Mexico OCS
                       Region, December 1987. New Orleans, LA. OCS Study MMS 88-0035. 456 pp.

              Petrazzuolo,G. 1981. Preliminary report: an environmental assessment of drilling fluids and cuttings releases
                       onto the outer continental shelf. Washington,DC: U.S. Environmental Protection Agency.

              Phillips, N.W. and B.M. James, eds. 1988. Offshore Texas and Louisiana marine ecosystems data synthesis.
                       Volume 11: synthesis report. U.S. Department of the Interior, Minerals Management Service, Gulf of
                       Mexico OCS Region, New Orleans, LA. OCS Study MMS 88-0067. 477 pp.

              Portnoy, J.W. 1977. Nesting colonies of seabirds and wading birds, coastal Louisiana, Mississippi@ and
                       Alabama. FWS/OBS-77/07. Washington, DC. U.S. Fish and Wildlife Service, Office of Biological
                       Services. 126 pp.

              Price, J. 1991. Written communication, Oil Spill Risk Analysis Report. U.S. Dept. of the Interior, Minerals
                       Management Service, Branch of Environmental Operations and Analysis, Herndon, VA.

              Quinn, T. 1990. Written communication. 1989 fishing license data. Mississippi Dept of Wildlife, Fisheries
                       and Parks, Bureau of Marine Resources, computer data. 4 pp.

              Rabalais, S.C., C.R. Arnold, and N.S. WohIschlag. 1981. The effects of Lrtoc I oil on the eggs and larvae of
                       red drum (Sciaenops ocellata). The Texas Journal of Science, 33(l):33-38.










                VI-28

                Rabalais, N.N., B.A. McKee, D.J. Reed, and J.C. Means. 1991. Fate and effects of nearshore discharges of
                         OCS produced waters. U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS
                         Region, New Orleans, LA_ OCS Study MMS 91-0004 through 91-0006. 3 vols.

                Raloff, J. 1991. NORM: The new hot wastes. Science News. 140(17):264-267.

                Randolph, T.M., R.C. Ayers, R.A. Shaul, A.D. Hart, W.T. Shebs, J.P. Ray, S.A. Savant-Malhiet, and R.V.
                         Rivera. 1992. Radium fate and oil removal for discharged produced sand. In: Proceedings, 1992
                         International Produced Water Symposium, San Diego, CA. In press.

                Ratzlaff, K.W. 1980. Land-surface subsidence in the Texas coastal region. U.S. Depl- of the Interior,
                         Geological Survey, Open-File Report 80-969. 19 pp.

                Reggio, V.C., Jr., comp. 1989. Petroleum structures as artificial reefs: a compendium. Fourth International
                         Conference on Artificial Habitats for Fisheries, Rigs-to-Reefs Special Session, November 4, 1987,
                         Miami, Fla. OCS Study MMS 89-0021. 176 pp.

                Reid, D.F. 1980. Data provided by Dr. David F. Reid, Naval Ocean Research & Development Activity,
                         National Space Technology Laboratory, Bay St. Louis, MS.

                Restrepo and Associates. 1982. Lrtoc I oil spill economic impact study. Final report prepared for the Bureau
                         of Land Management, contract No. AA851-CTO-65. El Paso, TX 3 vols.

                Rezak, R. and T.J. Bright. 1981. Northern Gulf of Mexico topographic features study. Final report to the
                         BLM, contract No. AA551-CT8-35. College Station, TX Texas A&M Research Foundation and
                         Texas A&M University, Department of Oceanography. 5 vols. Available from NTIS, Springfield, VA_
                         PB81-248635.

                Rezak, R., T.J. Bright, and D.W. McGrail. 1983. Reefs and banks of the northwestern Gulf of Mexico: their
                         geological, biological, and physical dynamics. Final Technical Report No. 83-1-T.

                Rezak, R., T.J. Bright, and D.W. McGrail. 1985. Reefs and banks of the northwestern Gulf of Mexico: their
                         geological, biological, and physical dynamics. New York, NY: John Wiley and Sons.

                Roach, E.R., M.C. Watzin, J.D. Scurry, and J.B. Johnston. 1987. Wetland trends in coastal Alabama. In:
                         Lowery, T.A. ed. Symposium on the natural resources of the Mobile Bay estuary. Alabama Sea Grant
                         Extension Service, Auburn University. MASGP-87-007. pp 92-101.

                Roberts, H.H. 1991. Geologic hazards of the northern Gulf of Mexico continental slope: implications to
                         resource development. International Transfer Meeting. In press.

                Roberts, H.H., R. Sassen, and P. Aharon. 1988. Petroleum-derived authigenic carbonates of the Louisiana
                         continental slope. In: Proceedings of Oceans '88, October 31-November 2, 1988. Baltimore, MD:
                         Marine Technology Society, IEEE.

                Roberts, K.J. and M.E. Thompson. 1983. Petroleum production structures: economic resources for Louisiana
                         sport divers. Louisiana Sea Grant College Program. Baton Rouge, LA. Louisiana State University,
                         Center for Wetland Resources.










                                                                                                                       VI-29

              Robinson, M.K. 1973. Atlas of monthly mean sea surface and subsurface temperature and depth of the top of
                       the thermocline Gulf of Mexico and Caribbean Sea. Scripps Institution of Oceanography, reference
                       73-8, 12 pp. + 93 figures.

              Rogers & Associates Engineering Corporation. 1990. Management and disposal alternatives for NORM wastes
                       in oil production and gas plant equipment Prepared for the American Petroleum Institute, Dallas, TX

              Rossi, S.S., J.W. Anderson, and G.S. Ward. 1976. Toxicity of water-soluble fractions of four test oils for the
                       polychaetous annelids. Neanthes arenaceodentata and Capitella capitata. Environ. Pollut. 10:9-18.

              Rushton, W.F. 1979. The Cajuns: from Acadia to Louisiana. New York, NY. Farrar Straus Giroux. 342 pp.

              Ryan, P.G. 1988. Effects of ingested plastic on seabird feeding: evidence from chickens. Mar. Poll. Bull.
                       19(3):125-128.

              Ryder, R.R. 1978. Breeding distribution, movements, and mortality of snowy egrets in North America. In:
                       Sprunt A., IV, J.C. Ogden, and S. Winckler, eds. Wading birds. National Audubon Society, New York,
                       NY. pp. 197-206.

              Schmied, R.L. and E.D. Burgess. 1987. Marine recreational fisheries in the southeastern United States: an
                       overview. Mar. Fish. Rev. 49(2):2-7.

              Schmidly, D.J. 1981. Marine mammals of the southeastern United States coast and the Gulf of Mexico.
                       FWS/OBS-80/41. Washington, DC: U.S. Fish and Wildlife Service, Office of Biological Services. 163
                       PP.

              Schroeder, W.W., M.R. Dardeau, J.J. Dindo, P. Fleischer, KL Heck, Jr., and W. Schultz. 1988. Geological and
                       biological aspects of hardbottom environments on the L:MAFLA shelf, northern Gulf of Mexico. In:
                       Proceedings, Oceans '88: a partnership of marine interests, volume 1. Baltimore, MD. pp. 17-21.

              Schulze, R.H. 1991. Practical guide to atmospheric dispersion modeling. Trinity Consultants, Inc., Dallas, TX
                       (Training course notes, February 4, 1991.

              Science Applications International Corporation (SAIC). 1986. Gulf of Mexico physical oceanography program
                       final report: Years 1 and 2, Vol. 11: Technical report. Prepared for the Minerals Management
                       Service, Gulf of Mexico OCS Region. OCS Study MMS 85-0094. 378 pp.

              Scott, G.P., D.M. Burn, L. Hansen, and R.E. Owen. 1989. Estimates of bottlenose dolphin abundance in the
                       Gulf of Mexico from regional aerial surveys. National Marine Fisheries Service, Miami Laboratory,
                       Coastal Resources Division. Contribution Number CRD-88/89-07.

              Sharkey, J. 1990. Written communication. 1989 fishing license data. Louisiana Dept of Wildlife and
                       Fisheries, Seafood Division, computer data. 4 pp.

              Shaw, A. 1991. Personal communication. Telephone conversation concerning platform removals for 1989 and
                       1990. September 26,1991, New Orleans, LA

              Shaw, R.F., J.H. Cowan, Jr., and T.L. Tillman. 1985. Distribution and density of Brevoortia patronus (Gulf
                       menhaden) eggs and larvae in the continental shelf waters of western Louisiana. Bull. Mar. ScL
                       36(l):96-103.










                VI-30

                Shinn, A.D. 1971. Possible future petroleum potential of upper Miocene and Pliocene. In: Future petroleum
                        provinces of the U.S.--their geology and potential. American Association of Petroleum Geologists
                        Memoir 15(2):824-835.

                Shuba, P.J. and A_J. Heikamp, Jr. 1989. Toxicity tests on biological species indigenous to the Gulf of Mexico.
                        In: Proceedings, 1989 Oil Spill Conference ... February 13-16, 1989, San Antonio, TX Washington,
                        DC. American Petroleum Institute. pp. 309-316.

                Sikora, W.B., J.P. Sikora, and R.E. Turner. 1983. Marsh buggies, erosion, and the air-cushioned alternatives.
                        In: Proceedings of the Water Quality and Wetland Management Conference, New Orleans, LA.

                Sims, H.W. 1970. Operation bird wash. The Florida Naturalist. 43(2):4345.

                Skinner, S.YL and WX Reilly. 1989. The Exxon Valdez oil spill. A report to the President.

                Slijper, E.J. 1979. Whales. Ithaca, NY: Cornell University Press.

                Snavely, E.S., Jr. 1989. Radionuclides in produced waters: a literature review. American Petroleum Institute
                        Publication No. 4517.


                Sorensen, P.E. 1990. Socioeconomic effects of OCS oil and gas development. In: Synthesis of available
                        biological, geological, chemical, socioeconomic, and cultural resource information for the South Florida
                        area. Jupiter, FL: Continental Shelf Associates, Inc. pp. 609-629.

                Southwest Research Institute (SRI). 1981. Ecological investigations 'of petroleum production platforms in the
                        central Gulf of Mexico submitted to Bureau of Land Management. . Contract No. AA551-CT8-17.
                        San Antonio, TX pp. 5-14.

                Spain, D., S. Laska, R. Seydlitz, E. Triche, and IC Bishop. 1990. The social and economic impact of offshore
                        oil extraction and production on involved communities. As presented in the "Impact of Offshore Oil
                        Exploration and Production on the Social Institutions of Coastal Louisiana" session of the MMS, Gulf
                        of Mexico OCS Region, Tenth Annual Information Transfer Meeting, November 1.3-15, 1990. New
                        Orleans, LA

                Spell, R. 1990. Evaluation and use of a pit management system. In: Proceedings of the First International
                        Symposium on Oil and Gas Exploration and Production Waste Management Practices. U.S.
                        Environmental Protection Agency. pp. 491-502.

                Spendelow, J.R. and S.R. Patton. 1988. National atlas of coastal waterbird colonies contiguous United States:
                        1976-1982. U.S. Fish and Wildlife Service Biological Report 88(5). x+326 pp.

                Spitzer, N.R. 1987. Cultural conservation on the Gulf Coast. In: Proceedings: eighth annual Gulf of Mexico
                        information transfer meeting. Sponsored by Minerals Management Service, Gulf of Mexico OCS
                        Region, December 1987. New Orleans, LA. OCS Study MMS 88-0035. 456 pp.

                Sports Fishing Institute. 1988. Economic impact of sport fishing in Louisiana, Mississippi, Alabama, Texas,
                        and Florida. Washington, DC.

                Sports Fishing Institute. 1989a. TED issue heats up. Bulletin No. 407. Washington, DC. 11). 6.

                Sports Fishing Institute. 1989b. Marine fisheries bycatch issues. Bulletin No. 405. Washington, DC. p. 6.











                                                                                                                            VI-31

               St Pb, KM. 1990. An assessment of produced water impacts to low-energy, brackish water systems in southeast
                        Louisiana. In: Proceedings of the First International Symposium on Off and Gas Exploration and
                        Production Waste Management Practices. U.S. Environmental Protection Agency. pp. 3142.

               State of Florida Marine Fisheries Commission. 1988. Written communications. Various biological reports
                        prepared for the commission meetings as information background. 60 pp.

               Steele, P. and H.M. Perry (eds). 1990. The blue crab fishery of the Gulf of Mexico United States: a regional
                        management plan. Gulf States Marine Fisheries Commission, Ocean Springs, MS. No. 21. 150 pp.

               Stephenson, M.T. 1991. Components of produced water- a compilation of results from several industry studies.
                        In: Proceedings, First International Conference on Health, Safety, and Environment, The Hague, The
                        Netherlands, 10-14 November 1991 In press.

               Stephenson, M.T. and I.R. Supernaw. 1990. Offshore Operators Committee 44 platform study- radionuclide
                        analysis results. November 1990.

               Stone, R.B., H.L. Pratt, R.O. Parker, Jr., and G.E. Davis. 1979. A comparison of fish populations on a artificial
                        and natural reef in the Florida Keys. Mar. Fish. Rev. 41(9):1-11.

               Subra, W.A. 1990. Unsuccessful ofifield waste disposal techniques in Vermilion Parish, Louisiana. In:
                        Proceedings of the First International Symposium on Off and Gas Exploration and Production Waste
                        Management Practices. U.S. Environmental Protection Agency. pp. 995-1000.

               SUSIO (State University System of Florida, Institute of Oceanography). 1977. Baseline monitoring studies,
                        Mississippi, Alabama, Florida outer continental shelf 1975-1976. Executive summary prepared for the
                        Bureau of Land Management, Contract No. 08550-CT5-30. St. Petersburg, FT_ pp. 41-55. Available
                        from NTIS, Springfield, VA. PB-282-801/AS.

               SUSIO (State University System of Florida, Institute of Oceanography). 1978. Final report on the baseline
                        environmental survey of the MAFLA lease areas, Contract No. 08550-CT4-11 submitted to the Bureau
                        of Land Management .. June 21, 1976 ... revision submitted April 1978. St. Petersburg, FL. pp.
                        134-136.

               Sutter, F.C. and T.D. McIlwain. 1987. Species proffies: life histories and environmental requirements of coastal
                        fishes and invertebrates (Gulf of Mexico)--sand seatrout and silver seatrout. U.S. Fish and Wildlife
                        Service Biological Report 82(11.72). U.S. Army Corps of Engineers, TR EL-82-4. 16 pp.

               Swanson, R.L. and C.I. Thurlow. 1973. Recent subsidence rates along the Texas and Louisiana coasts as
                        determined from tide measurements. Journal of Geophysical Research. 78(15):2665-2671.

               Symposium. 1980. Research on environmental fate and effects of drilling fluids and cuttings. Proceedings of
                        a symposium held January 21-24, 1980, Lake Buena Vista, FL. Washington, DC. Symposium. 2 vols.

               Tatum, W.M. 1985. Alabama Dept. of Conservation and Natural Resources' letter to the Honorable H.L.
                        Calagan in Washington, DC. Gulfshore, AL.

               Teas, H.J., E.O. Duerr, and J.R. Wilcox. 1986. Effects of South Louisiana crude off and dispersants on
                        Rhizophora mangroves. American Petroleum Institute.

               Teas, W. 1989. Personal communication. Sea Turtle Stranding and Salvage Network, MiamL F1_










                 VI-32

                 Tennyson, E.J. 1988. Personal communication. U.S. Dept. of the Interior, Minerals Management Service,
                         Washington, DC.

                 Texas Air Control Board. 1989. Air monitoring report, 1988. Austin, TX 40 pp.

                 Texas A&M University. 1988. Second annual report to the National Oceanic and Atmospheric Administration
                         Analysis of bivalves and sediments for organic chemicals and trace elements from Gulf of Mexico
                         estuaries. 600 pp.

                 Texas Parks and Wildlife Department 1989. Written communication. Texas colonial waterbird census
                         summary - 1988. Nongame and Endangered Species Program Wildlife Division - Texas Parks and
                         Wildlife Department: 7-N-570-02/13/89. 123 pp.

                 Thompson, N.B. 1988. The status of loggerhead, Caretta caretta; Kemp's ridley, Lepidochelys kernpi; and
                         green, Chelonia mydas sea turtles in U.S. waters. Mar. Fish. Rev. 50(3).

                 Thorhaug, A., J. Marcus, and F. Booker. 1986. Off and dispersed off on subtropical and tropical seagrasses
                         in laboratory studies. Mar. Poll. Bull. 17(8):357-361.

                 Tonetti, R. 1990. Perspectives on oil and gas issues in RCRA reauthorization. U.S. Environmental Protection
                         Agency, Washington, DC. Speech given at a citizen's conference on the problems of off and gas waste;
                         sponsored by the Deep South Network on Oil and Gas Waste and the National Audubon Society,
                         September 8, 1990, New Orleans, LA

                 Torgrimson, G. 1981. Personal communication. Formula taken from evaporation model using oil spill fate
                         model OSSM of NOAA, based on D. Mackay and S. Paterson.

                 Tresslar, R.C. 1974. Corals. pp. 116-139. In: Bright, T.J. and L. Pequegnat, eds. Biota oj'the West Flower
                         Garden Bank. Gulf Publishing Company, Houston, TX 435 pp.

                 Tucker & Associates, Inc. 1990. Sea turtles and marine mammals of the Gulf of Mexico, proceedings of a
                         workshop held in New Orleans, August 1-3, 1989. OCS Study MMS 90-0009. U.S. Dept. of the
                         Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA.

                 Tunnel, J.W., Jr. 1981. Sebree Bank: observations derived from scuba dive during a Bureau of Land
                         Management sponsored cruise during August 24-27, 1981.

                 Turner, R.E. and M.S. Brody. 1983. Habitat suitability index models: northern Gulf of Meidco brown shrimp
                         and white shrimp. Washington, DC. U.S. Fish and Wildlife Service. FWS/OBS-82/10.54. 24 pp.

                 Turner, R.E. and D.R. Cahoon. 1987. Causes of wetland loss in the coastal Central Gulf of Mexico. Prepared
                         under MMS Contract 14-12-OWl-30252. New Orleans, LA.- USDI, Minerals Management Service,
                         Gulf of Mexico OCS Region. OCS Study MMS 87-0119 (Vol. 1: Executive Summary), 87-0120 (Vol.
                         II: Technical Narrative), and 87-0121 (Vol. III: Appendices).

                 Tuttle, J.R. and A.J. Combe 111. 1981. Flow regime and sediment load affected by alterations of the
                         Mississippi River. In: Cross, R.D. and D.L. Williams, eds. Proceedings, National Symposium.
                         Freshwater inflow estuaries.     U.S. Fish and Wildlife Service, Office of Biological Services.
                         FWS/OBS-81/104. pp. 334-348.











                                                                                                                         VI-33

               U.S. Dept. of the Army. Corps of Engineers. 1991. Port Fourchon, Louisiana: draft feasibility report and draft
                        environmental impact statement New Orleans District, New Orleans, LA.

               U.S. Congress. Office of Technological Assessment 1985. Oil and gas technologies for the Arctic and
                        deepwater. Washington, DC. 227 pp.

               U.S. Congress. Office of Technological Assessment. 1991. Bioremediation for marine spills. Background paper
                        OTA-BP-0-70. Washington, DC.

               U.S. Dept of Commerce. 1967. United States coast pilot 5. Atlantic coast, Gulf of Mexico, Puerto Rico and
                        Virgin Islands, 6th ed. Washington, DC:- U.S. Coast and Geodetic Survey, Environmental Science
                        Services Administration. 301 pp.

               U.S. Dept. of Commerce. Bureau of Economic Analysis. 1990. BEA regional projections to 2040. Vol. 1: states.
                        Washington, DC: U.S. Government Printing Office.

               U.S. Dept. of Commerce. National Marine Fisheries Service. 1977. Environmental assessment of an active
                        oil field in the northwestern Gulf of Mexico, 1976-1977. Galveston, TX U.S. Dept. of Commerce,
                        National Marine Fisheries Service, Southeast Fisheries Center. 759 pp.

               U.S. Dept. of Commerce. National Marine Fisheries Service. 1988a. Aerial surveys of the U.S. Gulf of Mexico
                        waters, 1983-1986. Unpublished data.

               U.S. Dept. of Commerce. National Marine Fisheries Service. 1988b. Processed fishery products, annual
                        summary 1986. Current fisheries statistics no. 8386. Washington, DC.

               U.S. Dept. of Commerce. National Marine Fisheries Service. 1989a. Fisheries of the United States, 1988.
                        Current fisheries statistics no. 8800. Washington, DC.

               U.S. Dept. of Commerce. National Marine Fisheries Service. 1989b. Annual report of the sea turtle stranding
                        and salvage network--Atlantic and Gulf coasts of the United States, January-December 1988.
                        CRD-88/89-19. Southeast Fisheries Center, Miami@ FL.

               U.S. Dept. of Commerce. National Marine Fisheries Service. 1990a. Fisheries of the United States, 1989.
                        Current fisheries statistics no. 8900. Washington, DC.

               U.S. Dept. of Commerce. National Marine Fisheries Service. 1990b. Status of investigation of Gulf of Mexico
                        bottlenose dolphin deaths. National Oceanic and Atmospheric Administration, National Marine
                        Fisheries Service, Southeast Fisheries Science Center, Miami, FL MIA-89/90-08.

               U.S. Dept. of Commerce. National Marine Fisheries Service. 1991a. Fisheries of the United States, 1990.
                        Current fisheries statistics no. 9000. Washington, DC. 111 pp.

               U.S. Dept. of Commerce. National Marine Fisheries Service. 1991b. Fishing trends and conditions in the
                        southeast region, 1990. Newlin, K., ed. Southeast Fisheries Center, Miami, FL. 84 pp.

               U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration. 1961-1986. Environmental Data
                        Service, National Climate Center.

               U.S. Dept of Commerce. National Oceanic and Atmospheric Administration. 1978. Tropical cyclones of the
                        north Atlantic Ocean, 1871-1980 (with storm track maps updated through 1985). Asheville, NC:
                        NOAA, Environmental Data Service, National Climatic Center. 174 pp.










                VI-34
                U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration. 1984. Analysis of oil discharges
                         from proposed tankering operations in the eastern Gulf of Mexico.      Office of Oceanography and
                         Marine Services, Strategic Assessment Branch. Rockville, MD. 16 pp.
                U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration.        1985. Gulf of Mexico coastal
                         and ocean zones strategic assessment: data atlases. February 1985.
                U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration.        1988a. Coastal management:
                         solution's to our Nation's coastal problems. Technical Assistance Bulletin No. 101. December 1988.
                U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration. 1988b. National estuarine
                         inventory: the quality of shellfish growing waters in the Gulf of Mexico. 43 pp.
                U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration. 1988c. National estuarine
                         inventory data atlas. Volume 4: public recreation facilities in coastal areas. 'December 1988.
                         Washington, DC.
                U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration. 1988d. Interagency task force
                         on persistent marine debris. Office of the Chief Scientist, Ecology and Conservation Division.
                U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration. 1989. Coastal zone
                         management: a Federal-State partnership the management of coastal and marine resources. CZM
                         Information Exchange. January 1989.
                U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration. 1990. 50 years of population
                         change along the Nation's coasts: 1960-2010. U.S. Dept. of Commerce, National Oceanic and
                         Atmospheric Administration. Rockville, MD. 41 pp.
                U.S. Dept. of Commcrcc. National Oceanic and Atmospheric Administration. 1991., Coastal zone
                         management: a Federal-State partnership in the management of coastal and marine resources. CZM
                         Information Exchange, May 1991.
                U.S. Dept. of Energy. 1990. Interim report, National Energy Strategy: a compilation of public comments.
                         Springfield, VA. U.S. Dept. of Commerce. 230 pp.

                U.S. Dept. of Energy. 1991a. Petroleum supply annual, vol. 1. DOE/EIA-0340(90)/l.

                U.S. Dept. of Energy. 1991b. Petroleum supply annual, vol. 2. DOE/EIA-0340(90)/2.
                U.S. Dept. of the Interior. Bureau of I-and Management. 1982. Environmental information on hurricanes,
                         deepwater technology, and Mississippi deltaic mudsfides in the Gulf of Mexico. Open File Report 80-
                         02. New Orleans, LA- U.S. Dept of the Interior, Bureau of Land Management. 139 pp.
                U.S. Dept. of the Interior. Fish and Wildlife Service. 1986. Whooping crane recovery plan. U.S. Fish and
                         Wildlife Service, Albuquerque, NM. vi+383 pp.
                U.S. Dept. of the Interior. Fish and Wildlife Service. 1987. Recovery plan for the Choctawhatchee, Perdido Key
                         and Alabama beach mouse. U.S. Dept. of the Interior, Fish and Wildlife Service, Atlanta, GA. 45 pp.
                U.S. Dept. of the Interior. Fish and Wildlife Service. 1988. Great Lakes and Northern Great plains piping
                         plover recovery plan. Twin Cities, MN: U.S. Dept. of the Interior. Fish and Wildlife Service. 160
                         PP.











                                                                                                                           VI-35


               U.S. Dept of the Interior. Fish and Wildlife Service. 1989. Annual narrative report. San Bernard National
                        Wildlife Refuge, Angelton, TX 6 pp.

               U.S. Dept. of the Interior. Geological Survey. 1984. Office of Energy and Marine Geology, personal
                        communication, October 1984.

               U.S. Dept. of the Interior. Minerals Management Service. 1982a. Final environmental impact statement.
                        Proposed OCS oil and gas lease Sale 70, SL George Basin. Washington, DC.

               U.S. Dept of the Interior. Minerals Management Service. 1982b. Proceedings: Third Annual Gulf of Mexico
                        information transfer meeting. Sponsored by Minerals Management Service, Gulf of Mexico OCS
                        Region, August 24-26, 1982, New Orleans, LA. TAMRF-MMS contract AA851-CT1-55. College
                        Station, TX Texas A&M Research Foundation. 230 pp.

               U.S. Dept of the Interior. Minerals Management Service. 1983. Final regional environmental impact
                        statement. Proposed OCS oil and gas lease Sales 72, 74, and 79 (Central, Western, and Eastern Gulf
                        of Mexico). Washington, DC. Available from NTIS, Springfield, VA.- Vol. 1, PB84-102805 and Vol.
                        2, PB84-102813.

               U.S. Dept of the Interior. Minerals Management Service. 1984a. OCS Map Series, Sheets I-VIII, Port
                        Arthur and Bouma Bank Quads. MMS 84-OW3.

               U.S. Dept. of the Interior. Minerals Management Service. 1984b. Final environmental impact statement,
                        proposed oil and gas lease Sales 94, 98, and 102 (eastern, central, and western Gulf of Mexico).
                        Washington,DC. OCS EIS/EAMMS84-0057. Available ftomNTIS,Springfleld,VA.- PB85-179737/AS.

               U.S. Dept of the Interior. Minerals Management Service. 1984b. Proceedings: Fourth Annual Gulf of Mexico
                        information transfer meeting. Sponsored by Minerals Management Service, Gulf of Mexico OCS
                        Region, November 15-17, 1983, New Orleans, LA. SAI-MMS Contract 29158. 1. Raleigh, NC: Science
                        Applications, Inc. 474 pp.

               U.S. Dept of the Interior. Minerals Management Service. 1985a. Final proposed program 5-year outer
                        continental shelf off and gas leasing program for mid-1987 through mid-1992.

               U.S. Dept of the Interior. Minerals Management Service. 1985b. Proceedings: Fifth Annual Gulf of Mexico
                        information transfer meeting. Sponsored by Minerals Management Service, Gulf of Mexico OCS
                        Region, November 28-29, 1984, New Orleans, LA SAIC-MMS Contract 29158.2. Raleigh, NC-
                        Science Applications, Inc. OCS Study MMS 85-0008. 497 pp.

               U.S. Dept of the Interior. Minerals Management Service. 1985c. Oil slick sizes and length of coastline affected:
                        a literature survey and statistical analysis. Prepared for the U.S. Dept of the Interior, Minerals
                        Management Service, Pacific OCS Region under Contract No. 14-12-Owl-30224.

               U.S. Dept of the Interior. Minerals Management Service. 1986a. Gulf of Mexico inert pollutant study. Internal.
                        report, summary.

               U.S. Dept. of the Interior. Minerals Management Service. 1986b. Proceedings: Sixth Annual Gulf of Mexico
                        information transfer meeting. Sponsored by Minerals Management Service, Gulf of Mexico OCS
                        Region, October 22-24, 1985, New Orleans, LA SAIC-MMS Contract 29158. OCS Study MMS
                        86-0073. 348 pp.










                VI-36

                U.S. Dept of the Interior. Minerals Management Service. 1987a. Oil spill response measures for offshore
                        oil and gas operations. Minerals Management Service, Alaska OCS Region, OCS Report MMS
                        87-0062.


                U.S. Dept. of the Interior. Minerals Management Service. 1987b. Final environmental impact statement.
                        Proposed OCS off and gas lease Sales 113, 115, and 116 (Central, Western, and Eastern Gulf of
                        Mexico). Washington, DC. Available from NTIS, Springfield, VA. PB88-128723.

                U.S. Dept. of the Interior. Minerals Management Service. 1987c. Programmatic environmental assessment:
                        structure removal activities, central and western Gulf of Mexico planning areas. OCS EIS/EA-MMS
                        874)002.


                U.S. Dept of the Interior. Minerals Management Service. 1987d. Northern California oil and gas lease Sale
                        91. Draft environmental impact statement Volume 1. Los Angeles, CA. OCS EIS/EA-MMS
                        87-0032.


                U.S. Dept. of the Interior. Minerals Management Service. 1987e. Proceedings: Seventh Annual Gulf of
                        Mexico information transfer meeting. Sponsored by Minerals Management Service, Gulf of Mexico
                        OCS Region, November 4-6, 1986, New Orleans, LA. Contract No. 14-12-"1-30,305. OCS Study
                        MMS 87-0058. 381 pp.

                U.S. Dept. of the Interior. Minerals Management Service. 1988a. National potential incident of
                        noncompliance (PINC) list. Revision no. 1. Offshore Inspection and Enforcement Division. May
                        1988.


                U.S. Dept. of the Interior. Minerals Management Service. 1988b. Accidents associated with oil and Lyas
                                                                                                                        0--
                        operations, Outer Continental Shelf, 1956-1986. OCS Report MMS 88-0011. Washington, DC.

                U.S. Dept. of the Interior. Minerals Management Service. 1988c. Meteorological databaseand synthesis for
                        the Gulf of Mexico. Prepared by Florida A&M University for the U.S. Dept. of the Interior, Minerals
                        Management Service, Gulf of Mexico OCS Region, New Orleans, Lk OCS Study MMS 88-0064. 486
                        pp-

                U.S. Dept. of the Interior. Minerals Management Service. 1989a. Proceedings: Ninth annual Gulf of Mexico
                        information transfer meeting. Sponsored by Minerals Management Service, Gulf of Mexico OCS
                        Region, October 25-27, 1988, New Orleans, Lk Contract No. 14-12-0001-30305. OCS Study MMS
                        89-0060. 430 pp.

                U.S. Dept. of the Interior, Minerals Management Service. 1989b. Federal offshore statistics: 1988. OCS
                        Report MMS 89-0082. 102 pp.

                U.S. Dept. of the Interior. Minerals Management Service. 1990a. Gulf of Mexico Sales 131, 135, and 137:
                        central, western, and eastern planning areas-final environmental impact statement 'Washington, DC.
                        OCS EIS/EA MMS 90-0042. Available from NTIS, Springfield, VA. P1390-273590.

                U.S. Dept. of the Interior. Minerals Management Service. 1990b. The Offshore Environmental Studies
                        Program (1973-1989): a summary of Minerals Management Service research conducted on the U.S.
                        outer continental shelf. OCS Report MMS 90-0095.

                U.S. Dept. of the Interior. Minerals Management Service. 1990c. Effects of noise on marine mammals. Draft
                        report, August 1990.











                                                                                                                      VI-37

              U.S. Dept of the Interior. Minerals Management Service. 1991a. OCS natural gas and oil resource
                      management comprehensive program, 1992-1997, proposed July 1991. 2 vols.

              U.S. Dept. of the Interior. Minerals Management Service. 1991b. Gulf of Mexico Sales 139 and 141: central
                      and western planning areas--draft environmental impact statement. Washington, DC. OCS EIS/EA
                      MMS 91-0054. Available from NTIS, Springfield, VA. PB 92-125376/AS (volume I) and PB 92-
                      125384/AS (volume II).

              JLLS. Dept of the Interior. Minerals Management Service. 1991c. Dispersion of NO. emissions from OCS
                      sources, Western Planning Area of the Gulf of Mexico. Unpublished internal report U.S. Dept. of
                      the Interior, Minerals Management Service, Gulf of Mexico OCS Region. 19 pp.

              U.S. Dept of the Interior. Minerals Management Service. 1991d. Unpublished database on oil spills.
                      Environmental Policy and Programs Division, Washington, DC.

              U.S. Dept of the Interior. National Park Service. 1982. Padre Island National Seashore: Texas General
                      Management Plan, Development Concept Plan.

              U.S. Dept. of the Interior. National Park Service. 1988. Statement for the Management of Gulf Islands
                      National Seashore.


              U.S. Dept of Transportation. Coast Guard. 1989. Polluting incidents in and around U.S. waters. Washington,
                      DC. Comdtinst M16450.2H.

              U.S. Environmental Protection Agency. 1976. Development document for interim final effluent limitations
                      guidelines and proposed new source performance standards for the oil and gas extraction point source
                      category. EPA 440/1-76-055a. Washington, DC. 154 pp.

              U.S. Environmental Protection Agency. 1980. Fact sheet on ocean dumping of radioactive waste materials.
                      Office of Radiation Programs, Washington, DC.

              U.S. Environmental Protection Agency. 1985. Compilation of air pollutant emission factors/volume I:
                      stationary point and area sources. AP-42, fourth edition. Research Triangle Park, NO U.S.
                      Environmental Protection Agency.

              U.S. Environmental Protection Agency. 1987. Report to the Congress on the management of waste from the
                      exploration, development, and production of crude oil, natural gas, and geothermal energy.
                      EPA-530-SW-88-003.

              U.S. Environmental Protection Agency. 1988. Report to Congress: Management of wastes from the
                      exploration, development, and production of crude oil, natural gas, and geothermal energy. Volume
                      1: Oil and gas. Office of Solid Waste and Emergency Response, Washington, DC. Available from
                      NTIS, Springfield, VA_- P1388-146220.

              U.S. Environmental Protection Agency. 1989. Our national Gulf treasure: Fact sheet GMP-FS-001. Office
                      of the Gulf of Mexico Program, John C. Stennis Space Center, Stennis Space Center, MS.

              U.S. Environmental Protection Agency. 1990. Methods to manage and control plastic wastes, report to
                      Congress. EPA/530-SW-89-051.










                 VI-38

                 U.S. Environmental Protection Agency. 1991. Office of Water, Washington, DC. Development document for
                          effluent limitation guidelines and standards for the offshore subcategory of the oil and gas extraction
                          point source category. EPA 440/1-91/055. Also supportive documents produced by the Office of Water
                          Regulations and Standards, Washington, DC. Economic impact analysis of proposed effluent limitation
                          guidelines and standards for the offshore oil and gas industry. Prepared by Eastern Research Group,
                          Inc. EPA 440/2-91-001.

                 Union Exploration Partners, Ltd. 1988. Plan of exploration: Pulley Ridge Blocks 629 and 630, leases OCS-G
                          6491 and 6492. Houma, LA.

                 University of Texas at Austin. 1981. Fundamentals of petroleum. Petroleum Extension Serfice: University of
                          Texas at Austin. Austin, TX

                 Van Buuren, J.T. 1984. Ecological survey of a North Sea gas leak. Great Britain: Pergamon Press Ltd. Mar.
                          Poll. Bull. 15(8):305-307.

                 Vargo, S., P. Lutz, D. Odell, E. Van Fleet, and G. Bossart. 1986. Effect of oil on marine turtles. Final report
                          to the Minerals Management Service, Contract No. 14-12-0001-30063. Prepared by the Florida
                          Institute of Oceanography.

                 Vaughan, D.S., J.V. Merriner, and J.W. Smith. 1988. The U.S. menhaden fishery- current status and utilization.
                          In: N. Davis (ed.). Fatty fish utilization: upgrading from feed to food. pp. 15-38. Raleigh, NC: Univ.
                          of North Carolina, Sea Grant Publ. 88-04. 405 pp.

                 Viada, S.T. 1980. Species composition and population levels of scleractinian corals within the Diploria-
                          Montastrea-Porites zone of the East Flower Bank, northwestern Gulf of Mexico. M.S. Thesis. Texas
                          A&M University, Dept. of Oceanography, College Station, TX 96 pp.

                 Vittor, B.A. and Associates, Inc. 1985. Tuscaloosa Trend regional data search and synthesis study (volume
                          I - synthesis report). Final report submitted to Minerals Management Service, Metairie, LA. Contract
                          No. 14-12-"1-30048. 477 pp.

                 Vujnovich, M.M. 1974. Yugoslavs in Louisiana. Gretna, LA- Pelican Publishing Company. 246 pp.

                 Walk, Haydel, and Associates, Inc. 1984. Potential impact of proposed EPA BAT/NSPS standards for
                          produced water discharges from offshore oil and gas extraction industry. Report to the Offshore
                          Operators Committee, New Orleans, LA-

                 Wallace, D.W. 1980. Distribution of Mississippi River water under high flow conditions in the Gulf of Mexico.
                          Florida Marine Research Publications, Florida Dept. of Natural Resources, Marine Research
                          Laboratory. 40 pp.

                 Ward, C.H., M.E. Bender, and D.J. Reish, eds. 1979. The offshore ecology investigation: effects of oil drilling
                          and production in a coastal environment Houston, TX William Marsh Rice University.

                 The Washington Post. 1990. Transformed oil states coming back from bust: Gulf crisis intensifies recovery
                          trend. October 16, 1990. Washington, DC.

                 Watkins, W.A. 1977. Sperm whale feeding. J. Mammal. 57(l):58-66.

                 Webb, J.W. 1988. Establishment of vegetation on oil-contaminated dunes. Shore and Beach. October. pp.
                          20-23.











                                                                                                                            VI-39

                Webb, J.W., S.K. Alexander, and J.K. Winters. 1985. Effects of autumn application of oil on Spartina
                         alterniflora in a Texas salt marsh. Environ. Poll., Series A- 38(4):321-337.

                Webb, J.W., G.T. Tanner, and B.H. Koerth. 1981. Oil spill effects on smooth cordgrass in Galveston Bay,
                         Texas. Contributions in Marine Science 24:107-114.

                Wells, P.G. 1984. The toxicity of off spill dispersants to marine organisms--a current perspective. In: Allen,
                         T.E., ed. Oil spill chemical dispersants: research, experience, and recommendations, STP 840..
                         Philadelphia, PA_- American Society for Testing and Materials. pp. 177-202.

                Westcott, Lt. Com. P. 1989. Personal communication, U.S. Dept. of Transportation, Coast Guard, Morgan City
                         Marine Safety Office.

                Wheeler, R.B. 1978. The fate of petroleum in the marine environment: special report. Houston, TX: Exxon
                         Production Research Co.


                White, W.A., T.R. Calnan, R.A. Morton, R.S. Kimble, T.G. Littleton, J.H. McGowen, H.S. Nance, and KE.
                         Schmedes. 1985. Submerged lands of Texas, Galveston-Houston area. Bureau of Economic Geology,
                         University of Texas. Austin, TX 145 pp.

                White, W.A., T.R. CaInan, R.A. Morton, R.S. Kimble, T.G. Littleton, J.H. McGowen, H.S. Nance, and K.E.
                         Schmedes. 1986. Submerged lands of Texas, Brownsville-Harlingenarea. Bureau of Economic Geology,
                         University of Texas. Austin, TX 138 pp.

                Wicker,  K.M. and N. Rabalais. 1988. Impacts of the outer continental shelf (OCS) related activities on
                         sensitive coastal habitats. In: Proceedings, ninth annual Gulf of Mexico information transfer meeting.
                         Sponsored by Minerals Management Service, Gulf of Mexico OCS Region, October 25-27,1988. New
                         Orleans, LA

                Wicker, K.M., R.E. Emmer, D. Roberts, and J. van Beek. 1989. Pipelines, navigation channels, and facilities
                         in sensitive coastal habitats: an analysis of Outer Continental Shelf impacts, Coastal Gulf of Mexico.
                         Volume I: technical narrative. U.S. Dept. of the Interior, Minerals Management Service, Gulf of
                         Mexico OCS Region, New Orleans, LA. OCS Report MMS 89-0051. 470 pp.

                Williams, R.H. 1954. Distribution of chemical constituents of seawater in the Gulf of Mexico. In: Galtsoff, P.S.,
                         ed. Gulf of Mexico, its origin, waters and marine life. Fishery Bulletin 89. 55:143-149. Washington, DC.
                         U.S. Dept of the Interior, Fish and Wildlife Service.

                Williams, J., W.F. Grey, E.B. Murphy, and J.J. Crane. 1977. Drift bottle anabysis of eastern Gulf of Mexico
                         surface circulation. Memoirs of the Hourglass Cruises, volume IV, part III. Florida Dept. of Natural
                         Resources, Marine Research Laboratory. 134 pp.

                Wingert,R.C. 1988. Geophysical survey and commercial fishing conflicts, environmental studies, and conflict
                         mitigation in the Minerals Management Service Pacific OCS Region. In: Oceans'88: apartnership
                         of marine interests. NewYorkNY. Institute of Electrical and Electronics Engineers. Vol.1,pp.
                         150-155.


                Winker, C.D. 1982. Cenozoic shelf margins, northwestern Gulf of Mexico Basin. Trans. Gulf Coast Assoc. Geol.
                         Soc. 32:427-448.











                 VI-40
                 Witzig, J. 1986. Rig fishing in the Gulf of Mexico--1984, marine recreational fishing survey results. In:
                          Proceedings, sixth annual Gulf of Mexico information transfer meeting. Sponsored by Minerals
                          Management Service, Gulf of Mexico OCS Region, October 22-24, 1985. New Orleans, LA OCS
                          Study MMS 86-0073. pp. 103-105.
                 Witzig, J. 1990. Personal communication. U.S. Dept. of Commerce, National Marine Fisheries Service, National
                          Fishery Statistics Program, Silver Springs, MD

                 Woodward-Clyde Consultants. 1982. Draft abstract hydrography-southwest Florida shelf ecosystems study.
                          Contract no. AA851-CTO-50. New Orleans, IA- Woodward-Clyde Consultants. 5 pp.

                 Workshop. 1983. Mobile Bay area drilling fluids transport workshop, December 6-8, 1983, Mobile, AL.
                 Wyers, S.C., H.R. Frith, R.E. Dodge, S.R. Smith, A.H. Knap, and T.D. Sleeter. 1986. Behavioral effects of
                          chemically dispersed off and subsequent recovery in Diploria stfigosa (Dana). Mar. Ecol. 7(l):23-42.

                 Zaloudek, D.A. 1992. Personal communication. Program Manager, Louisiana Dept. of Environmental Quality,
                          Radiation Protection Division, Licensing and Registration Section.

                 Zieman, J.C. 1982. The ecology of the seagrasses of south Florida: a community profile. FWS/OBS-82/25.
                          Washington, DC: U.S. Fish and Wildlife Service, Office of Biological Services.

                 Zieman, J.C., R. Orth, R.C. Phillips, G. Thayer, and A Thornhaug. 1984. The efffects of off on seagrass
                          ecosystems. In: J. Cairns and A Buikema, eds. Recovery and restoration of marine ecosystems.
                          Stoneham, MA. Butterworth Publications. pp. 37-64.

                 Zingula, R.P. 1975. Effects on drilling operations on the marine environment. In: Conference proceedings:
                          environmental aspects of chemical use in well-drilling operations (May 1975, Houston, TX).
                          Washington, DC: U.S. Environmental Protection Agency, Office of Toxic Substances. pp. 433-449.

                 Zobell, C.E. and J.F. Prokop. 1966. Microbial oxidation of minerals oils in Barataria Bay bottom deposits. Z
                          Allg. Mikrobiol 6:143-162.


                 The following references were used as background references and are not cited in the text:

                 Alabama Dept of Industrial Relations, Research and Statistics. 1990. Alabama county historical series; annual
                          average, 1986-1989. January-August 1990. Montgomery, AL.

                 American Petroleum Institute (API). 1988. Basic petroleum data book, petroleum industry statistics. Volume
                          VIII, No. 2. May 1988.

                 American Petroleum Institute. 1989. Fate and effects of produced water discharges in nearshore marinG
                          waters. Washington, DC. American Petroleum Institute.

                 Amos, A.F. 1989. The occupance of hawksbills (Eretmochelys iinbricata) along the Texas coast In: Proceedings
                          of the ninth annual workshop on Sea Turtle Conservation and Biology. U.S. Dcpt. of Commerce,
                          National Oceanographic and Atmospheric Administration. Technical Memorandum NMFS-SEFC-232.
                          306 pp.











                                                                                                                             VI-41

                Anderson, J.W. 1985. Toxicity of dispersed and undispersed Prudhoe crude oil fraction to shrimp, fish and
                         their larvae. Prepared for the American Petroleum Institute, Washington, DC. 60 pp.

                Anderson, C.M. and R.B. LaBelle. 1988. Update of occurrence rates for accidental off spills on the U.S.
                         Outer Continental Shelf. In: Proceedings of Oceans '88, October 31-November 2, 1988. Baltimore,
                         MD: Marine Technology Society, IEEE. pp. 1673-1676.

                Antonius, A. and A. Weiner. 1982. Coral reefs under fire. J. Mar. Ecol. 3:255-277.

                Applied Technology Research Corporation. 1990. Socioeconomic impacts of declining outer continental shelf
                         oil and gas activities in the Gulf of Mexico. Preliminary draft report prepared for the U.S. Dept. of
                         the Interior, Minerals Management Service under Contract No. 14-12-0001-30335.

                Armstrong, H.W., K Fucik, J.W. Anderson, and J.M. Neff. 1979. Effects of oil field brine effluent on
                         sediments and benthic organisms in Trinity Bay, Texas. Mar. Environ. Res. 2:55-69.

                Artic Laboratories Limited, ESL Environmental Sciences Limited, and SKM Consulting Ltd. 1983. Draft
                         report: Offshore oil and gas production waste characteristics, treatment methods, biological effects,
                         and their applications to Canadian regions. April 1983. DSS File No. 47SS-KE145-2-0245.

                Aten, L.E. 1983. Indians of the upper Texas coast. New York, NY: Academic Press.

                Auburn University. 1987. Travel in Alabama, 1987: a study of travelers in Alabama during 1987 and the
                         economic impact of their spending. Prepared by Dr. James W. Adams, Dept of Marketing and
                         Transportation, Auburn Univ. Published by the Alabama Bureau of Tourism and Travel.

                Bahr, Jr., L.M., J.W. Day, Jr., S.E. Bayley, C. Neill, S.G. Leibowitz, J. Fruci. 1983. Ecological characterization
                         of the Mississippi Deltaic Plain Region: a narrative with management recommendations. Washington,
                         DC: U.S. Fish and Wildlife Service, Biological Services Program. FWS/OBS-82/69.

                Bak, R.P.M. 1978. Lethal and sublethal effects of dredging on reef corals. Mar. Poll. Bull. 9-14-16.

                Bak, R.P.M. 1987. Effects of chronic oil pollution on a Caribbean coral reef. Mar. Poll. Bull. 18(10):534-539.

                Bak, R.P.M. and J.H.B.W. Elgershuizen. 1976. Patterns of oil sediment rejection in corals. Mar. Biol.
                         37:105-113.


                Baker, J.M. 1971. The effects of oil on plant physiology. In: Cowell, E.B. (ed.). Ecological effects of oil
                         pollution. London: Applied Science Publishers. pp. 88-98.

                Ballou, T.G., R. Dodge, S. Hess, and A. Knap. 1989. Tropical oil pollution investigations in coastal systems
                         (tropics): the effects of untreated and chemically dispersed Prudhoe Bay crude off on mangroves,
                         seagrasses, and corals in Panama. In: Flaherty, L.M., ed. Oil dispersants: new ecological approaches,
                         ASTM, STP 1018. American Society for Testing and Materials, Philadelphia, PA. pp. 229-256

                Barrett, B.B. and E.J. Ralph. 1976. Environmental conditions relative to shrimp production in coastal
                         Louisiana. Louisiana Dept. of Wildlife and Fisheries. Technical Bulletin No. 21. 20 pp.

                Baxter, L II, E.E. Hays, G.R. Hampson, and R.H. Backus. 1982. Mortality of fish subjected to explosive shock
                         as applied to oil well severance on Georges Bank. Woods Hole Oceanographic Institution Technical
                         Report WHOI-82-54. Woods Hole, MA-











                VI-42
                Beeler, E.E. and T.J. O'Shea. 1988. Distribution and mortality of the West Indian Manatee (Trichechus
                         manatus) in the southeastern United States: a compilation and review of recent information. Volume
                         2: The Gulf of Mexico coast. National Geology Research Center, report no. 88-09.

                Bellrose, F.C. 1976. Ducks, geese and swans of North America: a completely new and expanded version of
                         the classical work by F.H. Kortright. 2nd ed. rev. Harrisburg, PA-- Stackpole Books. 543 pp.

                Berryhffl, H.L., Jr., A.R. Trippett, and D. MihalyL 1982. Geology of the continental shelf edge and upper
                         continental slope of southwest Louisiana. BLM Open File Report 82-02. U.S. DepiL of the Interior,
                         Bureau of Land Management. New Orleans, LA- 6 maps.

                Boehm, P.D. and D.L. Fiest. 1980a. Aspects of the transport of petroleum hydrocarbon; to the offshore
                         benthos during the Lrtoc-l blowout in the Bay of Campeche. In: Proceedings of a symposium on
                         preliminary results from the September 1979 Researcher/Pierce Lxtoc-l cruise, Key Biscayne, FL, June
                         9-10, 1980. Boulder, CO: U.S. Dept. of Commerce, National Oceanic and Atmospheric Admin. pp.
                         267-340.

                Boehm, P.D. and D.L. Fiest 1980b. Surface water column transport and weathering of petroleum
                         hydrocarbons during the Ixtoc-1 blowout in the Bay of Campeche and their relation to surface oil and
                         microlayer compositions. In: Proceedings of a symposium on preliminary results from the September
                         1979 Researcher/Pierce Ixtoc-1 cruise, Key Biscayne, FL, June 9-10, 1980. Boulder, CO: U.S. Dept
                         of Commerce, National Oceanic and Atmospheric Admin. pp. 267-340.

                Boesch, D.F. 1987. Louisiana estuaries: issues, resources, status, and management. In: Magoon, O.T., H.
                         Converse, D. Minor, L.T. Tobin, D. Clark, and G. Domurat, eds. Proceedings of the Fifth
                         Symposium on Coastal and Ocean Management, Seattle, WA.

                Brooks, J.M., M.C. Kennicutt 11, I.R. MacDonald, D.I-Wilkinson, N.L. Guinasso Jr., and R.R. Bidigare. 1989.
                         Gulf of Mexico hydrocarbon seep communities: Part IV --- descriptions of known chemosynthetic
                         communities. Offshore Technology Conference, May 14, 1989, Houston, TX
                Brooks, J.M., D.A. Weisenburg, C.R. Schwab, E.L. Estes, and R.F. Shokes. 1981. Surficial sediments and
                         suspended particulate matter. In: Middleditch, B.S. ed. Environmental effects of offshore oil
                         production. New York, NY: Plenum Press. pp. 69-111.

                Bryan, C.E. T.J. Cody, and G.C. Matlock. 1982. Organisms captured by the commercial shrimp fleet on the
                         Texas brown shrimp (Penaeus aztecus Ives) grounds. Texas Parks and Wildlife Department, Technical
                         Series No. 31. 26 pp.

                Bull, G.D. 1982. Scleractinian coral communities of two inshore high island fringing reefs at Magnetic Island,
                         North Queensland. Mar. Ecol. Prog. Ser. 7:267-272.

                Burk and Associates, Inc. 1977. Unique ecological features of the Louisiana coast Prepared for the
                         Louisiana State Planning Office, Coastal Resources Program, Baton Rouge, LA. 2nd printing, revised.

                Burns, ICA- and A.H. Knap. 1989. The Bahia las Minas oil spill, hydrocarbon uptake by reef building corals.
                         Mar. Poll. Bull. 20(8):391-398.

                Carlson, P.R., Jr., and J.G. Acker. 1985. Effects of in situ shading on Thalassia testudinum: preliminary
                         experiments. In: Proceedings of the 12th annual conference on wetlands restoration and creation,
                         sponsored by Hillsborough Community College, Tampa, FL. pp. 64-73.











                                                                                                                         VI-43

               Centaur Associates, Inc. 1986. Indicators of the direct economic impacts due to oil and gas development in
                        the Gulf of Mexico. OCS Study MMS 86-0016. U.S. Dept. of the Interior, Minerals Management
                        Service, Gulf of Mexico OCS Region, New Orleans, LA. 424 pp.

               Center for Environmental Education (CEE). 1988. 1987 Texas coastal cleanup report. 105 pp.

               Conklin, P.J., D.G. Doughtie, and KA. Roa. 1980. Effects of barite and used drilling muds on crustaceans,
                        with particular reference to the grass shrimp, Palaemonetes, pugio. In: Research on environmental fate
                        and effects of drilling fluids and cuttings proceedings, Lake Buena Vista, FL. 2:912-943.

               Continental Shelf Associates, Inc. (CSA). 1984. Impact reconnaissance following an anchoring incident at the
                        East Flower Garden Bank coral reef, August 1984.

               Continental Shelf Associates, Inc. (CSA). 1986. Southwest Florida shelf regional biological communities
                        survey, marine habitat atlas - year 3; volume 1, maps. OCS Study MMS 86-0072.

               Continental Shelf Associates, Inc. (CSA). 1991. Southwest Florida nearshore benthic habitat study, narrative
                        report. New Orleans, LA. U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico
                        OCS Region. OCS Study MMS 89-0080. 55 pp.

               Continental Shelf Associates, Inc. (CSA) and Martel Laboratories, Inc. 1985. Florida Big Bend seagrass
                        habitat study, narrative report. A final report by Continental Shelf Associates, Inc. submitted to the
                        Minerals Management Service, Metairie, LA- Contract No. 14-12-OMI-30188.

               Cook, C.B. and A.H. Knap. 1983. Effects of crude, oil and chemical dispersants on photosynthesis in the brain
                        coral Diplofia strigosa. Mar. Biol. 78:21-27,

               Cox, B.A- 1987. Structure removal: an offshore operators committee perspective. Unpublished report by
                        Marathon Oil Company, Technology Center, Littleton, CO.

               Cummins, J.E. 1988. Extinction: the PCB threat to marine mammals. The Ecologist 8(6).

               Curl, H., Jr. 1957. The hydrography of the inshore northeastern Gulf of Mexico. Contribution No. 113 from
                        the Oceanographic Institute, Florida State University, Tallahassee, FL.

               Dames and Moore. 1979. Mississippi, Alabama, Florida (MAFLA) outer continental shelf baseline
                        environmental survey 1977/1978. Final report to the Bureau of Land Management, Contract No.
                        AA550-CT7-34. New Orleans, LA.- Vol. 1-A, pp. 101-121; Vol. 1-B, p. 281. Available from NTIS,
                        Springfield, VA. (1-A) PB-294-227/AS; (1-B) PB-294-228/AS.
               Danek, L.J. and M.S. Tomlinson. 1981. Currents and hydrography of the Buccaneer Field and adjacent
                        waters. In: Middleditch, B.S. ed. Environmental effects of offshore oil production. New York, NY:
                        Plenum Press. pp. 355-383.

               Davenport, G. 1989. Written communication. 1988. Commercial fisheries landings by inshore water body.
                        Miami, FL: U.S. Dept. of Commerce, National Marine Fisheries Service, Statistics Division, Landings
                        Data. 4 pp.









                VI-44
                Day, R.H., D.H.S. Welite, and F.C. Coleman. 1985. Ingestion of plastic pollutants by marine birds. In:
                        Shomura, R.S. and H.O. Yoshida, eds. Proceedings of the workshop on the fate and ftnpact of marine
                        debris, November 27-29,1984, Honolulu, HA. U.S. Dept. of Commerce, NOAA Tech. Memo., NMFS,
                        NOAA-TM-NMFS-SWFC-54. pp. 344-386.
                Diener, R.A. 1975. Cooperative Gulf of Mexico estuarine inventory and study, Texas: area description.
                        NOAA technical report NMFS circular 393. Seattle, WA. U.S. Dept. of Commerce, National Oceanic
                        and Atmospheric Administration. p. 2.
                Dodge, R. 1982. Growth characteristics of reef-building corals within and external to a naval ordnance range:
                        Vieques, Puerto Rico. In: Proc. Fourth Int. Coral Reef Symp., Manila, 1981.
                Dodge, R.E. and J.R. Vaisnys. 1977. Coral population patterns: responses to sedimentafion and turbidity
                        associated with dredging. J. Mar. Res. 35:715-730.
                Dornbusch, D.M. and Company, Applied Economic Systems, and Abt Associates. 1987. Impacts of outer
                        continental shelf (OCS) development on recreation and tourism--volume 2: final report and case
                        studies. A final report to the Minerals Management Service, Los Angeles, CA, under Contract No.
                        14-12-OWl-30166.

                Dugas, R.J. 1988. Administering to the Louisiana oyster fisheries. In: Program abstracts ofthe 1988 annual
                        meeting. National Shellfisheries Association, New Orleans, LA.
                Dustan, P. and J. Halas. 1987. Changes in the reef-coral community of Carysfort Reef, Key Largo, Florida:
                        1974 to 1982. Coral Reefs 6:91-106.

                Egana, A.C. and L.H. DiSalvo. 1982. Mass expulsion of zooxanthellae by Eastern Island corals. Pac. Sci.
                        36:61-63.

                Ehrhardt, R. 1989. Personal communication. U.S. Environmental Protection Agency, Water Permits Division,
                        Region V1, Dallas, TX

                Environmental Science and Engineering, Inc. and LGL Ecological Research Associates, Inc. 1986. Southwest
                        Florida shelf benthic communities study, year 5, annual report.         Prepared for the Minerals
                        Management Service, Gulf of Mexico OCS Region, Contract No. 14-12-"1-30211. 3 vols. OCS
                        Study MMS 86-0074, 86-0075, and 86-0076.
                Environmental Science and Engineering, Inc., LGL Ecological Research Associates, Inc., and Continental Shelf
                        Associates, Inc. 1987. Southwest Florida shelf ecosystems study data synthesis report Submitted
                        under Contract No. 14-12-0001-30276 to the Minerals Management Service, New Orleans, LA_ 3 vols.

                FAO-ACMRR. 1978. Mammals in the seas. Volume 1: Food and Agricultural Organization of the United
                        Nations, Rome, Italy. 264 pp.
                Fernandez-Partagas, J. and M.A. Estoque. 1981. Climatology and meteorology of the Gulf of Mexico.
                        Proceedings of environmental research needs in the Gulf of Mexico (GOMEX), Vol. IIA_ U.S. Dept.
                        of Commerce. pp. 89-126.
                Fischel, M. 1987. Preliminary assessment of the effect of an oil spill on a Louisiana marsh. In: Proceedings,
                        1987 oil spill conference... April 6-9,1987, Baltimore, MD. Washington,DC: American Petroleum
                        Institute. pp. 489-494.











                                                                                                                       VI-45
               Fitzpatrick, M. 1990. Common misconceptions about the RCRA Subtitle C exemption for wastes from crude
                       off and natural gas exploration, development and production. In: Proceedings, First International
                       Symposium on Oil and Gas Exploration and Production Waste Management Practices, September 10-
                       13, 1990, New Orleans, LA- U.S. Environmental Protection Agency. pp. 169-178.
               Florida Dept. of Environmental Regulation. 1988. 1988 Florida water quality assessment--305(b) Technical
                       Assessment. 289 pp.

               Florida Dept. of Labor and Employment Security. Bureau of Labor Market Information. 1990. Labor force
                       summary, 1990 preliminary estimates. Tallahassee, FL.

               Fry, D.M., LE. Addiego, and C.R. Grau. 1987. Seabird oil toxicity. Final report to the Minerals Management
                       Service, Pacific OCS Region, Contract No. 14-12-0001-29112/SBO408(A)-81-C-0509.
               Fucik, KW., T.J. Bright, and KS. Goodman. 1984. Measurement of damage, recovery, and rehabilitation of
                       coral reefs exposed to oil. In: Cairns, J., Jr. and A.L. Buidemo, Jr., eds. Restoration of habitats
                       impacted by oil spills. Boston, MA. Butterworth Publishers. pp. 115-133.
               Gabanski, L 1989. Personal communication, U.S. Dept. of the Army, Corps of Engineers, Operations
                       Division, New Orleans District

               Gagliano, S.M., KJ. Meyer-Arendts, and KM. Wicker. 1981. Land loss in the Mississippi River deltaic plain.
                       In: Transactions, 31st Annual Meeting, Gulf Coast Association of Geological Societies. 31:295-300.
               Gallaway, B.J. 1981. An ecosystem analysis of oil and gas development on the Texas-Louisiana continental
                       shelf. FWS/OBS-81/27. Washington, DC. U.S. Fish and Wildlife Service, Office of Biological
                       Services. 89 pp.

               Gambell, R. 1968. Aerial observations of sperm whale behavior. Norsk Hvalfangsttidende 57(6):126-138.
               Geraci, J.R. and D.J. St. Aubin. 1980. Offshore petroleum resource development and marine mammals: a
                       review and research recommendation. Marine Fisheries Review. November 1980; 112 pp. (Reprint).
               Getter, C.D., G.I. Scott, and J. Michel. 1981. The effects of oil spills on mangrove forests: a comparison of
                       five oil spill sites in the Gulf of Mexico and the Caribbean Sea. In: Proceedings, 1981 oil spill
                       conference, March 2-5, 1983, Atlanta, GA. Washington, DC.- American Petroleum Institute. pp. 535-
                       540.

               Giezentanner, B. 1989. Personal communication. Refuge Manager, Aransas National Wildlife Refuge, Texas.
               Gittings, S.R., and T.J. Bright. 1986. Assessment of coral recovery following an incident of anchoring damage
                       at the Flower Garden Bank, northwestern Gulf of Mexico. Report to NOAA, National Marine
                       Sanctuaries Division, Washington, DC. 45 pp.
               Goertner, J.F. 1981. Fish-kill ranges for oil well severance explosions. Naval Surface/Weapons Center Report
                       NSWC TR 81-149. Silver Springs, MD.
               Gollop, J. 1989. The eskimo curlew. In: Chandler, W.J. and L Labate, eds. Audubon Wildlife Report
                       1988/1989. San Diego, CA. Academic Press, Inc. pp. 583-595.
               Gollop, J.B., T.W. Barry, and E.H. Iversen. 1986. Eskimo curlew- a vanishing species? Saskatchewan Natural
                       History Society, Special Publication No. 17. 160 pp.










                 VI-46


                 Gollop, M.S., J.R. Goldsberry, and R.A_ Davis. 1974. Disturbance to birds by gas compressor noise simulators,
                          aircraft, and human activity in the Mackenzie Valley and the North Slope, 1972. Arctic Gas, Biological
                          Report Series, Vol. 14, second edition. L.G.L. Limited and Environmental Research Associates. pp.
                          88-91.

                 Grant, E.M. 1970. Notes on an experiment upon the effect of crude oil on live corals. Fish. Notes Dept. Prim
                          Ind. Brisbane. 1:1-13.

                 Gulfwatch. 1989. Galveston Bay. Galveston, Texas: Texas Sea Grant Program at Texas A&M University at
                          Galveston. Vol. 1, No. 2. (March 1989). 8 pp.

                 Halbouty, M.T. and G.C. Hardin, Jr. 1956. Genesis of salt domes of Gulf Coastal Plain. AAPG Bull.
                          40(4):737-746.

                 Hannon, L.J. and E. Lear. 1989. Draft oil spill risk estimates: Gulf of Mexico Outer Continental Shelf Sales
                          131/135/137. (draft copy).
                 Hannon, L.J. and E.M. Lear. 1990. Draft od-spill risk estimates: Gulf of Mexico (Proposed Lease Sales
                          131/135/137) Outer Continental Shelf. U.S. Dept. of the Interior, Minerals Management Service,
                          Branch of Environmental Modeling. 412 pp.

                 Hele, I., D. deSylva, and C.A. Carpenter. 1955. Drift currents in the red tide area of the east coast region
                          of the Gulf of Mexico. Report to Florida State Board of Conservation. Marine Laboratory, the
                          University of Miami. 31 pp.
                 Hightower, M. 1989. Written communication. 1988 commercial fisheries landings by inshore water body.
                          Galveston, TX U.S. Dept. of Commerce, National Marine Fisheries Service, Statistics Division,
                          Landings Data. 4 pp.

                 Hofman, B. 1990 Personal communication. May 9, 1990. Marine Mammal Commission.

                 Hofstetter, R.P. 1988. Trends in the Galveston Bay oyster fishery, 1979-1984. Texas Parks and Wildlife
                          Department, Coastal Fisheries Branch, Management Data Series No. 125. 36 pp.

                 Hofstetter, R.P. and I.M. Ray. 1988. Managing public oyster reefs: Texas experience. In: Program abstracts
                          of the 1988 annual meeting. National Shellfisheries Association, New Orleans, LA.

                 Hoggard, W. 1990. Personal communication. Meeting regarding threatened and endangered species on the
                          Chandeleur and Breton Islands, LA. August 30, 1990. Slidell, LA.

                 Holt, S., S. Rabalais, N. Rabalais, S. Cornelius, and J.S. Holland. 1975. Effects of an oil spill on salt marshes
                          at Har'bor Island, Texas. 1. Biology. Conference on Assessment of Ecological Impacts of Oil Spills.
                          Institute of Biological Sciences, Washington, DC. pp. 344-353.

                 Holmes, W.N. 1984. Petroleum pollutants in the marine environment and their possible effects on seabirds.
                          In: Hodgson, I.E., ed., Reviews in Environmental Toxicology. Elsevier, NY: Elsevier Science
                          Publishers. pp. 251-317.

                 Holmes, W.N. and J. Cronshaw. 1977. Biological effects of petroleum on marine birds. In; Malins, D.C., ed.
                          Effects of petroleum on Arctic and subarctic marine environments and organisms. Volume 2:
                          Biological effects. New York, NY: Academic Press. pp. 359-398.











                                                                                                                         VI-47

              Hudson, J.H. and D.M. Robbin. 1980. Effects of drilling mud on the growth rate of the reef-building coral,
                       Montastrea annularis. In: Geyer, R.A. (ed.) Marine Environmental Pollution, 1. Hydrocarbons.
                       Amsterdam, Elsevier Scientific Publishing Co. pp. 455-470.

              Humphrey, W.E. 1956. Tectonic framework of northeast Mexico. Trans., GCAGS. 6:25-35.

              Jaap, W.C. 1979. Observations on zooxanthellae expulsion at Middle Sambo Reef, Florida Keys. Bull. Mar.
                       ScL 29-414-422.


              Jaap, W.C. 1984. The ecology of the south Florida coral reefs: a community profile. U.S. Fish and Wildlife
                       Service, Biol. Serv. Program. FWS/OBS-82/08; OCS Study MMS 84-0038.

              Jeffrey, L.M. 1979. Status of knowledge. Summary of the Tar Ban Workshop, Co-hosted by Texas
                       Department of Water Resources and National Oceanic and Atmospheric Administration, June 26-27,
                       1979, Austin, TX

              Johannes, R.E. 1975. Pollution and degradation of coral reef communities. In: Wood, E.G.F. and R.E.
                       Johannes, eds. Tropical marine pollution. Amsterdam: Elsevier Scientific Publishing Co. pp. 13-51.

              Kallio, R.E. 1976. The variety of petroleums and their degradations. In: Sources, effects, and sinks of
                       hydrocarbons in the aquatic environment Amer. Inst. Biol. Sci., Washington, DC.

              Keithly, W.R. 1989. The effect of decline in Louisiana's hydrocarbon activity on the commercial seafood
                       industry. In: Proceedings: Ninth Annual Gulf of Mexico information transfer meeting. Sponsored
                       by Minerals Management Service, Gulf of Mexico OCS Region, October 25-27, 1988. New Orleans,
                       LA_ OCS Study MMS 89-0060. pp. 358-360.

              Keithly, W.R. and A.W. Liebzeit. 1987. The Louisiana commercial fishing sector: a review of commercial
                       landings, fishermen and craft, and processing and wholesaling, 1960-86. Louisiana Sea Grant, Center
                       for Wetland Resources, Louisiana State University, Baton Rouge, LA. 39 pp.

              Keller, B.D., J.B.C. Jackson, J.D. Cubit, J.D. Brawn, K.A. Burns, R.L. Caldwell, N.C. Duke, S.D. Garrity, H.M.
                       Guzman, K.W. Kaufmann, S.C. Levings, M.J. Marshall, R.Steger, and R.C. Thompson. 1989. Effects
                       of the Panama off spill: biology. As presented in the "Oil Spills in Tropical Environments" session of
                       the MMS Gulf of Mexico OCS Region 1989 Information Transfer Meeting, December 5-7, 1989, New
                       Orleans, LA.

              Kendall, J.J. Jr., E.N. Powell, S.J. Connor, and T.J. Bright. 1983. The effects of drilling fluids (muds) and
                       turbidity on the growth and metabolic state of the coral Acropora ceMcomis, with comments on
                       methods of normalization for coral data. Bull. Mar. Sci. 33:336-352.

              Kendall, J.J. Jr., E.N. Powell, S.J. Connor, T.J. Bright, and C.E. Zastrow. 1984. The importance of monitoring
                       metabolic recovery in the coral Acropora cervicomis after short-term exposure to drilling muds:
                       calcification rate and protein concentration. Coral Reefs 2:215-225.

              Kendall, J.J. Jr., E.N. Powell, S.J. Connor, T.J. Bright, and C.E. Zastrow. 1985. Effects of turbidity on
                       calcification rate, protein concentration and the free amino acid pool of the coral Aaopora cervicomis.
                       Mar. Biol. 87:33-46.










                  VI-48

                  Knap, AH., R.E. Dodge, T.D. Sleeter, S.C. Wyers, H.R. Frith, and S.R. Smith. 19&,!. The effects of
                          chemically dispersed off on corals: research in progress. In: Oil spill dispersants: five years of'
                          research. Abstracts. Philadelphia, PA- American Society for Testing and Materials.

                  Knap, AH., T.D. Sleeter, R.E. Dodge, S.C. Wyers, H.R. Frith, and S.R. Smith. 1983. The effects of oil spills
                          and dispersant use on corals: a review and disciplinary experimental approach. Oil and Petrochemical
                          Pollution. 1(3):157-169.

                  Knecht, AT. 1988. The impact of produced water discharges from oil and gas operations on the estuarine
                          environment in Louisiana: a literature review. Prepared for the State of Louisiana, Department of'
                          Environmental Quality.

                  Knowlton, N., J.C. Lang, M.C. Rooney, and P. Clifford. 1981. Evidence for delayed mortality in
                          hurricane-damaged Jamaican staghom corals. Nature 294:251-252.

                  Kolpack, R.L, R.W. Stearns, and G.L. Armstrong. 1978. Sinking of oil in Los Angeles Harbor, California,
                          following the destruction of the Sansinena. In: Proceedings of the conference on assessment of'
                          ecological impacts of oil spills, 14-17 June 1978, Keystone, CO. Washington, DC: American Institute
                          of Biological Sciences. pp. 378-392.

                  Kcc)ns, C.B. and P.H. Monaghan. 1976. Input of hydrocarbons from seeps and recent biogenic sources. In:
                          Sources, effects and sinks of hydrocarbons in the aquatic environment: Proceedings of the Symposium.
                          American Univ. pp. 94-108.

                  Koons, C.B., C.D. McAuliffe, and F.T. Weiss. 1977. Environmental aspects of extraction operations in
                          offshore coastal waters. Jour. Petrol. Technol. 29:723-729.


                  Kraemer, T.F. and D.F. Reid. 1984. The occurrence and behavior of radium in formation waters of the U.S.
                          Gulf Coast region. Isotope Geoscience 2:153-174.

                  Krahl, R. 1989. Written communication. Memorandum entitled "Pollution Spills, Outer Cbntinental Oil and
                          Gas Operations," dated August 10, 1989.

                  Krahl, R.B. 1990. Written communication. Memo dated June 4, 1990, Pollution spills, outer continental shelf'
                          oil and gas operations.

                  Lasker, H.R. 1980. Sediment rejection by reef corals: roles of behavior and morphology in Montastrea
                          annularis (Linnaeus). J. Exp. Mar. Biol. Ecol. 47:77-87.

                  Leatherman, S.P. 1982. Barrier island handbook. University of Maryland. 109 pp.

                  Leatherwood, S. and R.R. Reeves. 1982. Bottlenose dolphin (Tursiops truncatus) and other toothed
                          cetaceans. In: Chapman, J.A and G.A. Feldhamer, eds. Wild mammals of North America.
                          Baltimore, MD: John Hopkins University Press. pp. 369-414.

                  Leatherwood, S., D.K. Caldwell, and H.E. Winn. 1976. Whales, dolphins, and porpoises of the western North
                          Atlantic: a guide to their identification. NOAA Technical Report NMFS CIRC-396.

                  Lee, R.F. 1977. Fate of oil in the sea. In: Fore, P.L., ed. Proceedings of the 1977 Oil Spill Response
                          Workshop. FWS/OBS-77/24. Washington, DC: U.S. Fish and Wildlife Service, Office of Biological
                          Services. pp. 43-54. Available from NTIS, Springfield, VA- PB-282-375.











                                                                                                                             V149

                Louisiana Dept. of Environmental Quality. 1990. Monthly data summaries of ozone measurements across
                        southern Louisiana for 1989 and 1990.

                Louisiana Dept. of Labor. 1990. Labor market information, 1986-1989. January-August 1990. Baton Rouge,
                        LA

                Louisiana Dept. of Natural Resources. 1991. Information Supplement. Lease Sale #135. July 29, 1991.

                Louisiana Office of Tourism 1989. Louisiana travel journal, special edition. July 1989. Baton Rouge, LA

                Loya, Y. 1976. Effects of water turbidity and sedimentation on the community structure of Puerto Rican
                        corals. Bull. Mar. Sci. 26:450-466.


                Loya, Y. and B.C. Rinkevich. 1980. Effects of oil pollution on coral reef communities. Mar. Ecol. Prog. Ser.
                        3:167-180.


                Mackay, D., I. Buist, R. Mascarenhas, and S. Paterson. 1979. Experimental studies of dispersion and emulsion
                        formation from oil slicks. In: Workshop on the Physical Behavior of Off in the Marine Environment,
                        Princeton University. Prepared for the National Weather Service, Silver Springs, MD. pp. 1.17-1.40

                Malins, D.C., H.O. Hodgins, U. Varanasi, S. Chan, B.B. McCain, D.D. Weber, and D.W. Brown. 1982.
                        Sublethal effects of petroleum hydrocarbons and trace metals, including biotransformations, as
                        reflected by morphological, chemical, physiological, pathological, and behavioral indices.
                        Environmental Conservation Division, Northwest and Alaska Fisheries Center, National Marine
                        Fisheries Service, Seattle. 268 pp.

                Malme, C.I., P.R. Miles, C.W. Clark, P. Tyack, and J.E. Bird. 1983. Investigations of the potential effects of
                        underwater noise from petroleum industry activities on migrating gray whale behavior. Final Report
                        for the period June 7, 1982-July 31, 1983. No. 5366 prepared for the U.S. Dept. of the Interior,
                        Minerals Management Service, Alaska OCS Region, Anchorage, AIC

                Malme, C.I., P.R. Miles, C.W. Clark, P. Tyack, and J.E. Bird. 1985. Investigations of the potential effects of
                        underwater noise from petroleum industry activities on feeding humpback whale behavior. BBN
                        Report No. 5851. Prepared under contract no. 14-12-OWl-29033 for the U.S. Dept of the Interior,
                        Minerals Management Service, Alaska OCS Region, Anchorage, AK OCS Study MMS 85-0019.

                Malme, C.I., P.R. Miles, G.W. Miller, W.J. Richardson, D.G. Roseneau, D.H. Thompson, and C.R. Greene,
                        Jr. 1989. Analysis and ranking of the acoustic disturbance potential of petroleum industry activities and
                        other sources of noise in the environment of marine mammals in Alaska. Report No. 6945. Final
                        report prepared under contract 14-12-0001-303654 for the U.S. Dept. of the Interior, Minerals
                        Management Service, Alaska OCS Region, Anchorage AK

                Martineau, D. 1989. Mass mortality of bottlenose dolphins: review of the final report of Dr. GeracL
                        Unpublished report by the Department of Avian and Aquatic Animal Medicine, New York State
                        College of Veterinary Medicine, Cornell University, Ithaca, NY.

                McKennhan, D.S. 1989. Personal communication. Vice President of INTEC Engineering, Inc.

                McKinna, T.G. 1985. The Alvenus oil spill. In: Proceedings, Sixth annual Gulf of Mexico information transfer
                        meeting. Sponsored by Minerals Management Service, Gulf of Mexico OCS Region, October 22-24,
                        1985. New Orleans, LA OCS Study MMS 86-0073. pp. 84-86.











                  VI-50
                  Mead, J.G. 1977. Records of sei and Bryde's whales from the Atlantic coast of the United States, the Gulf
                           of Mexico, and the Caribbean. In: Report of the Special Meeting of the Scientific Committee on Sei
                           and Bryde's Whales. Rept. Int. Whal. Comm. (Special Issue 1), International Whaling Commission.
                           Cambridge, UX pp. 113-116
                  Meade, N.F. and V.R. Leeworthy. 1986. Public expenditures on outdoor recreation in coastal areas of the
                           USA. Washington, DC: U.S. Dept of Commerce, NOAA, NOS, Strategic Assessment Branch, Ocean
                           Assessments Division. 18 pp.
                  Mendelssohn, I.A. 1982. Sand dune vegetation and stabilization in Louisiana. In: Boesch, D.F., ed.
                           Proceedings of the Conference on Coastal Erosion and Wetland Modification in Louisiana: Causes,
                           Consequences, and Options. Washington, DC: U.S. Fish and Wildlife Service, Biological Services
                           Program. FWS/OBS-82/59. pp. 187-207.

                  Mendelssohn, I.A. and K. L. McKee. 1987. Experimental field and greenhouse verification of the influence
                           of saltwater intrusion and submergence on marsh deterioration: mechanisms of action. Chapter 8.
                           In: Turner, R.E. and D.R. Cahoon, eds. 1987. Causes of wetland loss in the coastal Central Gulf of
                           Mexico. Vol. II: technical narrative. OCS Study MMS 87-0120. Prepared under MMS Contract 14-
                           12-OWI-30252. New Orleans, LA. USDOI, Minerals Management Service, Gulf of Mexico OCS
                           Region.
                  Mendelssohn, I.A., M. Hester, C. Sasser, and M. Fischel. Submitted. The effect of Louisiana crude oil
                           discharge from a pipeline break on the vegetation of a southeast Louisiana brackish marsh.

                  Mendelssohn, I.A., K.L. McKee, and W.H. Patrick, Jr. 1981. Oxygen deficiency in Spartina altemiflora roots:
                           metabolic adaptation to anoxia. Science 241:439-441.

                  Milan, C.S. and T. Whelan 111. 1978. Accumulation of petroleum hydrocarbons in a salt marsh ecosystem
                           exposed to steady state oil input. In: Proceedings of the conference on assessment of ecological
                           impacts of oil spills, 14-17 June 1978, Keystone, CO. Washington, DC: American Institute of
                           Biological Sciences. pp. 875-893.
                  Miles, P.R., C.I. Malme, and W.J. Richardson. 1987. Prediction of drilling site specific interactions of industrial
                           acoustic stimuli and endangered whales in the Alaskan Beaufort Sea. Report No. 61509. Prepared for
                           the U.S. Dept. of the Interior, Minerals Management Service, Alaska OCS Region, Anchorage, AK
                           OCS Study MMS 87-0084. Report No 6509.
                  Mississippi State Employment Service. 1990. Labor market trends, 1986-1989. January-August 1990. Jackson,
                           Ms.

                  Mixon, R.B., G.E. Murray, and T. Diaz. 1959. Age and correlation of Huizachal Group (Mesozoic), State of
                           Tamaulipas, Mexico. AAPG Bull. 43(4):757-771 and 43:2499 (addendum).
                  Muller, R. 1989. Written communication. 1988 annual landings summary. Florida Dept. of Natural
                           Resources. Division of Marine Resources, Marine Fisheries Information Landings Data. 22 pp.

                  Murray, G.E. 1961. Geology of the Atlantic and Gulf coastal province of North America. New York, NY:
                           Harper Bros. 692 pp.
                  National Research Council (NRC). 1985. Disposal of offshore platforms. Washington, DC: 'National Academy
                           Press. 88 pp.











                                                                                                                           VI-51

                Neff, J.M., W.L McCulloch, R.S. Carr, and K_A_ Retzer. 1980. Comparative toidcity of four used offshore
                         drilling muds to several species of marine animals from the Gulf of Me)dco. In: Research on
                         environmental fate and effects of drilling fluids and cuttings proceedings, Lake Buena Vista, FL.
                         2:866-881.


                Nelson, H.F. and E.E. Bray. 1970. Stratigraphy and history of the Holocene sediments in the Sabine-High
                         Island Area, Gulf of Mexico. In: Morgan, J.P., ed. Deltaic sedimentation; modern and ancienL
                         Special Publn. No. 15. Tulsa, OK- SEPM.

                Nero and Associates. 1983. Seabird-oil spill behavior study. Vol. I: Executive summary. Prepared for the
                         Minerals Management Service, Pacific OCS Region, Contract No. SB00408
                         (a)-80-C-550/AA851-CTO-70.

                Nicholls, J.L 1989. Distribution and other ecological aspects of piping plovers (Charadrius melodus) wintering
                         along the Atlantic and Gulf coasts. Masters Thesis, Auburn University.

                Offshore Operators Committee. 1975. Environmental aspects of produced waters from off and gas extraction
                         operations in offshore and coastal waters. Prepared by Sheen Technical Subcommittee. New Orleans,
                         IA- Offshore Operators Committee. 32 pp.

                Offshore Operators Committee. 1976. Environmental aspects of drilling muds and cuttings from oil and gas
                         extraction operations in offshore and coastal waters. Prepared by Sheen Technical Subcommittee.
                         New Orleans, LA. Offshore Operators Committee. 50 pp.

                Ogren, L.H. 1989. Distribution of juvenile and subadult Kemp's ridley sea turtles: preliminary results from
                         1984-1987 surveys.

                Oil Spill Intelligence Report. 1983. Whale mortality (August 1983).

                Otto, G.H. 1989. A national survey on naturally occurring radioactive materials (NORM) in petroleum
                         producing and gas processing facilities. Submitted to the American Petroleum Institute, July 1, 1989.

                Ottway, S.V. 1976. The comparative toxicities of crude oils, refined oil products and off emulsions. In: Baker,
                         J.M., ed. Marine ecology and oil pollution: (proceedings). New York, NY John Wiley & Sons. pp.
                         287-302.


                Otvos, E.G. 1980. Barrier island formation through nearshore aggradation - stratigraphic and field evidence.
                         Mar. Geo. 43:195-243.


                Payne, J.R., N.W. Flynn, P.J. Mankiewicz, and G.S. Smith. 1980a. Surface evaporation/dissolution partitioning
                         of lower-molecular-weight aromatic hydrocarbons in a down-plume transect from the Lrtoc-1 wellhead.
                         In: Proceedings of a symposium on preliminary results from the September 1979 Researcher/Pierce
                         Lrtoc-1 cruise, Key Biscayne, FL, June 9-10,1980. Boulder, CO: U.S. Dept of Commerce, National
                         Oceanic and Atmospheric Admin. pp. 239-266.

                Payne, J.R., G.S. Smith, P.J. Mankiewicz, R.F. Shokes, N.W. Flynn, V. Moreno, and J. Altamirano. 1980b.
                         Horizontal and vertical transport of dissolved and particulate-bound higher-molecular-weight
                         hydrocarbons from the Lrtoc-1 blowout In: Proceedings of a symposium on preliminary results from
                         the September 1979 Researcher/Pierce Lrtoc-I cruise, Key Biscayne, FL, June 9-10,1980. Boulder, CO:
                         U.S. Dept. of Commerce, National Oceanic and Atmospheric Admin. pp. 119-168.










                VI-52

                Pearson, C.E., comp. 1981. Investigation of an eighteenth century shipwreck off the Louisiana coast.
                        Anthropological study No. 2. Baton Rouge, LA. Dept. of Culture, Recreation and Tourism, Louisiana
                        Archaeological Survey and Antiquities Comm. 46 pp.

                Pearson, R.G. 1981. Recovery and recolonization of coral reefs. Mar. Ecol. Prog. Ser. 4:1105-122.

                Penland, S. and J.R. Suter.       1988.    Barrier island erosion and protection in Louisiana: a coastal
                        geomorphological perspective.      Transactions Gulf Coast Associations of Geological Societies.
                        38:331-342.

                Perry, H.M. and T.D. McIlwain. 1986. Species profiles: life histories and environmental requirements of
                        coastal fishes and invertebrates (Gulf of Mexico) -- blue crab. U.S. Dept. of the Interior, Fish and
                        Wildlife Service (Biological Report 82 (11.55)) and U.S. Army Corps of Engineers, Coastal Ecology
                        Group, Waterways Experiment Station (TR EL-82-4). 21 pp.

                Perry, H.M., G. Adkins, R. Condrey, R.C. Hammerschmidt, S. Heath, J.R. Herring, C. Moss, G. Perkins, and
                        P. Steele. 1984. A profile of the blue crab fishery of the Gulf of Mexico. October 1984. No. 9
                        (completion report--Contract No. 000-010). Ocean Springs, MS: Gulf States Marine Fisheries
                        Commission. 80 pp.

                Phillips, N.W. and M.J. Thompson. 1989. Offshore benthic communities. In: Continental Shelf and
                        Associates, eds. Chapter 5, Synthesis of available biological, geological, chemical, socioeconomic, and
                        cultural resource information for the south Florida area.


                Powell, E.N., M. Kasschau, E. Chen, M. Koenig, and J. Pecon. 1982. Changes in the free amino acid pool
                        during environmental stress in the gill tissue of the oyster, Crassostrea V*ginica. Comp. Biochem.
                        Physiol. A. Comp. Physiol. 71:591-598.

                Powell, E.N., S.J. Connor, J.J. Kendall, Jr., C.E. Zastrow, and T.J. Bright. 1984a. Recovery by the coral
                        Acropora cervicomis after drilling mud exposure. The free amino acid pool. Arch. Environ. Contam.
                        Toxicol. 13:243-258.


                Powell, E.N., J.J. Kendall, Jr., S.J. Connor, C.E. Zastrow, and T.J. Bright 1984b. Effect of eight outer
                        continental shelf drilling muds on the calcificaiton rate and free amino acid pool of the coral Acropora
                        cervicomis. Bull. Environ. Contam. Toxicol. 33:362-372.


                Quast,  W.D., M.A_ Johns, D.E. Pitts, Jr., G.C. Matlock, and J.E. Clark. 1988. Texas oyster fishery
                        management plan. Texas Parks and Wildlife Department, Coastal Fisheries Branch. Austin, TX 178
                        PP.

                Rabalais, N.N. 1990. Fate and effects of produced water discharges in coastal environments. In: Proceedings
                        of the First International Symposium on Oil and Gas Exploration and Production Waste Management
                        Practices. U.S. Environmental Protection Agency. pp. 503-514.

                Ray, J.P. 1980. The effects of petroleum hydrocarbons on corals. In: Petroleum and the Marine
                        Environment, Proceedings of Petromar 80. London: Graham and Trotman Ltd.

                Reed, A.R. 1987. Appendix B: Summary of ports and waterways use by OCS activities. In: Turner, R.E. and
                        D.R. Cahoon, eds. Causes of wetland loss in the coastal central Gulf of Mexico. Volume III. Prepared
                        under MMS Contract 14-124)001-30252. New Orleans, LA. U.S. Dept. of the Interior, Minerals
                        Management Service, Gulf of Mexico OCS Region. OCS Study MMS 87-0121.










                                                                                                                       VI-53

               Reggio, V.C., Jr. 1989. Response to beach debris in the Gulf of Mexico. In: Magoon, O.T., H. Converse,
                       D. Miner, L.T. Tobin, and D. Clark, eds. Coastal Zone '89: proceedings of the Sixth Symposium on
                       Coastal and Ocean Management, the Omni Hotel, Charleston, SC, July 11-14,1989. Volume 2. New
                       York, NY: American Society of Civil Engineers. pp. 1279-1284.

               Reimer, A.A. 1975. Effects of crude off on corals. Mar. Poll. Bull. 6:39-42.

               Renfro, W.C. and H.A. Brusher. 1982. Seasonal abundance, size distribution, and spawning of three shrimps
                       (Penaeus aztecus, P. seliferus, and A duorarum) in the northwestern Gulf of Mexico, 1961-1962. NOAA
                       Technical Memorandum NMFS-SEFC-94. 47 pp.

               Rhode Island, University of (Dept of Ocean Engineering and Graduate School of Oceanography) and Applied
                       Science Associates (Wakefield, RI). 1981. Assessing the impact of oil spills on a commercial fishery.
                       Final interim report for contract No. 11851-CTO-75. U.S. Dept. of the Interior, Bureau of Land
                       Management, New York OCS Office.

               Risebrough, R.W. 1978. Pollutants in marine mammals: a literature review and recommendations for research.
                       Prepared for the Marine Mammal Commission, Washington, DC. Available from NTIS, Springfield,
                       VA. PB-290 728.


               Rogers, C.S. 1983. Sublethal and lethal effects of sediments applied to common Caribbean reef corals in the
                       field. Mar. Poll. Bull. 14:378-382


               Rogers & Associates Engineering Corporation. 1989. Methods for measuring naturally-occurring radioactive
                       materials in petroleum production equipment. Prepared for American Petroleum Institute. RAE-
                       8837/1-1.

               Roy, KJ. and S.V. Smith. 1971. Sedimentation and coral reef development in turbid water: Fanning Lagoon.
                       Pac. Sci. 25:234-248.


               Rubinstein, N.I., R. Rigby, and C.N. D'Asaro. 1980. Acute and sublethal effects of whole used drilling fluids
                       on representative estuarine organisms. In: Research on environmental fate and effects of drilling
                       fluids and cuttings proceedings, Lake Buena Vista, FL. Vol 2:828-M.

               Runde, D. 1989. Written communication. 1987-88 aerial survey, Florida wading bird colonies. Florida Game
                       and Fresh Water Fish Commission, Nongame Wildlife Program, Survey Data. 40 pp.

               Scaffe, W.W., R.E. Turner, and R. Costanza. 1983. Coastal Louisiana recent land loss and canal impacts.
                       Baton Rouge, LA. Louisiana State University, Center for Wetlands Resources. Environ. Mgmt.
                       7(5):433-442.

               Schmidly, D.J. and D.L. Scarborough. 1990. Marine mammals of the Gulf of Mexico: past, present, and future.
                       In: Tucker & Associates, Inc. 1990. Sea turtles and marine mammals of the Gulf of Mexico,
                       proceedings of a workshop held in New Orleans, August 1-3, 1989. OCS Study MMS 904)009. U.S.
                       Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA.
                       pp. 63-64.

               Schroeder, W.W., M.R. Dardeau, J.J. Dindo, P. Fleischer, ICL Heck, Jr., and W. Schultz. 1988. Geological
                       and biological aspects of hardbottom environments on the L'MAFLA shelf, northern Gulf of Mexico.
                       In: Proceedings, Oceans '88: a partnership of marine interests. Volume 1. Baltimore, MD. pp. 17-21.










                VI-54

                Scott, L.M. 1989. Radioactive scale in petroleum production equipment and pipe. Louisiana Energy Indicators,
                         Louisiana State University. LSU/CES 89E-02.

                Shane, S.H., R.S. Wells, and B. Wursig. 1986. Ecology, behavior, and social organization of the bottlenose
                         dolphin: a review. Marine Mammal Science, 2(l):34-63.

                Shinn, E.A. 1972. Coral reef recovery in Florida and the Persian Gulf. Houston, TX Shell Oil Co.,
                         Environmental Research Dept 9 pp.

                Shinn, E.A., P.A. Dustan, and B.H. Lidtz. 1989. Impact assessment of exploratory wells drilled offshore
                         Florida. U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New
                         Orleans, LA. OCS Study MMS 89-0022.

                Smith, N.P. 1980. On the hydrography of shelf waters off the central Texas Gulf coast. Journal of Physical
                         Oceanography 10(5):806-813.

                Smultea, M. and B. Wursig. In press. Bottlenose dolphin reactions to the Mega Borg oil spill. In: U.S. Dept.
                         of the Interior, Minerals Management Service. Proceedings: Tenth annual Gulf of Mexico information
                         transfer meeting. Sponsored by Minerals Management Service, Gulf of Mexico OCS Region,
                         December 5-7, 1990, New Orleans, LA. Contract no. 14-354)001-30499. OCS Study MMS 90-0027.

                Sports Fishing Institute. 1987. Number of paid fishing license holders, license sales, and cost to fishermen,
                         fiscal year 1986. Bulletin No. 387. August 1987. Washington, DC. p. 5.

                Stanley, J.G. and M.A. Sellers. 1986. Species profiles: life histories and environmental requirements of coastal
                         fishes and invertebrates (Gulf of Mexico) -- American oyster. U.S. Dept. of the Interior, Fish and
                         Wildlife Service (Biological Report 82 (11.64)) and U.S. Army Corps of Engineers, Coastal Ecology
                         Group, Waterway Experiment Group (TR EL-82-4). 25 pp.

                Stright, M.J. 1988. Inundated archaeological sites of the Florida coastal region: a regional overview. In: U.S.
                         Dept of the Interior, Minerals Management Service. 1989. Archaeology on the Gulf of Mexico outer
                         continental shelf: a compendium of studies. U.S. Dept. of the Interior, Minerals Management, Gulf
                         of Mexico OCS Region, New Orleans, LA.

                Szaro, R.C., M.P. Dieter, G.H. Heinz, and J.F. Ferrell. 1978. Effects of chronic ingestion of South Louisiana
                         crude on mallard ducklings. Environmental Research. 17:426-436.

                Tagatz, M.E, J.M. Ivey, and J.L. Oglesby. 1979. Toxicity of drilling-mud biocides to developing estuarine
                         macrobenthic communities. Northeast Gulf Sci. 3:88-95.


                Texas A&M Research Foundation. 1974. Bathymetric map of Big and Little Adam Rock. Surveyed by Decca
                         Survey Systems, Inc. November 1974.

                Texas A&M University. 1972. Report on the environmental aspects of a supertanker port on the Texas Gulf
                         coast. TAMU-SG-73-201.


                Texas Employment Commission. 1990. Labor force estimates for Texas counties, 1986-1989. January-August
                         1990. Austin, TX

                Texas Water Commission. 1988. The State of Texas water quality inventory: 9th edition. LP 88-04.










                                                                                                                            VI-55

                Thompson, J.H. and T.J. Bright. 1977. Effects of drill mud on sediment clearing rates of certain hermatypic
                         corals. In: Proceeding, 1977 oil spill conference, March 8-10, 1977, New Orleans, LA. Washington,
                         DC. American Petroleum Institute.

                Thompson, M.J., A-D. Hart, and C.W. Kerlin. 1989. Exposure of deep seagrass beds off the west coast of
                         Florida to discharged drilling effluents. In: Englehardt, F.R., J.P. Ray, and A.H. Gillam, eds. Drilling
                         wastes. London: Elsevier Applied Science.

                Thompson, J.H., E.A. Shinn, and T.J. Bright. 1980. Effects of drilling muds on seven species of reef building
                         corals as measured in the field and laboratory. In: Geyer R.A- (ed.). Marine Environmental
                         Pollution, 1. Hydrocarbons. Amsterdam: Elsevier Scientific Publishing Company. pp. 433-454.
                Thorhaug, A. 1989. Dispersed oil effects on tropical nearshore ecosystems. pages 257-273 In: Flaherty, L.M.
                         ed. Oil dispersants: new ecological approaches, ASTM, STP 1018. American Society for Testing and
                         Materials, Philadelphia, PA-

                Timmermanns, W.J. 1989. Technology for larger deepwater pipelines lags behind industry's development
                         plans. Oil and Gas Journal, May 1, 1989. OGJ Special. pp. 68-78.

                U.S. Dept of Commerce. Bureau of Economic Analysis. 1988. Survey of current business. Volume 68, No.
                         4.

                U.S. Dept. of Commerce. Bureau of the Census. 1989. County business patterns, 1987: Alabama, Louisiana,
                         Mississippi, and Texas. Washington, DC: U.S. Government Printing Office.

                U.S. Dept of Commerce. Bureau of the Census. 1990a. County and city data book, 1988. Washington, DC:
                         U.S. Government Printing Office.

                U.S. Dept. of Commerce. Bureau of the Census. 1990b. Current population reports, Series P-26, No. 88-S-SC.
                         1988 population and 1987 per capita income estimates for counties and incorporated places: South.
                         Washington, DC. U.S. Government Printing Office.

                U.S. Dept of Commerce. National Marine Fisheries Service. 1987. Marine recreational fishery statistics
                         survey, Atlantic and Gulf Coasts, 1986. Current Fishery Statistics No. 8392. Washington DC. 127 pp.

                U.S. Dept of Commerce. National Marine Fisheries Service. 1988. Fisheries of the United States, 1987;
                         Current fisheries statistics no. 8700. Washington, DC.

                U.S. Dept. of Commerce. National Marine Fisheries Service. 1990. Fishing trends and conditions in the
                         southeast region, 1989. Washington, DC.

                U.S. Dept. of Commerce National Ocean Survey. (1975). Coastline of the U.S. (pamphlet). Washington, DC:
                         U.S. Government Printing Office.

                U.S. Dept. of Commerce National Oceanic and Atmospheric Administration. 1981. Operational discharges
                         of oil from marine transportation sources in the Gulf of Mexico. Office of Oceanography and Marine
                         Services, Strategic Assessment Branch. Rockville, MD. 17 pp.

                U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration. 1986. Marine environmental
                         assessment: Gulf of Mexico 1985 annual summary. Washington, DC.










                  VI-56

                  U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration. 1988. National status and
                          trends program for marine environmental quality. Progress report: a summary of selected data on
                          chemical contaminants in sediments collected during 1984, 1985, 1986, and 1987. NOAA Technical
                          Memorandum NOS OMA 44.


                  U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration. 1989a. National Estuarine
                          Reserve Research System, Status Report, May 1989.

                  U.S. Dept. of Commerce. National Oceanic and Atmospheric Administration. 1989b. NO,.okA Estuary of the
                          Month Seminar Series No.11--Tampa and Sarasota Bays: issues, resources, status, and management.
                          215 pp.

                  U.S. Dept. of     Energy. Energy Information Administration. 1990a. Monthly energy review, 1990.
                          DOE/EIA-0035.

                  U.S. Dept. of Energy. Energy Information Administration. 1990b. Natural gas monthly, 1990. DOE/EIA-0130.

                  U.S. Dept. of the Interior. Fish and Wildlife Service. 1979. Toxicity of crude oil to sandhill cranes (Grus
                          canadensis). Preliminary report P-D-1-6.12. Pautuxent Wildlife Research Center.

                  U.S. Dept. of the Interior. Fish and Wildlife Service. 1982. Life history requirements of selected finfish and
                          shellfish in Mississippi Sound and adjacent areas. FWS/OBS-81/51. 97 pp.

                  U.S. Dept. of the Interior. Fish and Wildlife Service. 1988. 1985 national survey of fishing, hunting, and
                          wildlife associated recreation. November 1988. Washington, DC. 167 pp.

                  U.S. Dept of the Interior. Fish and Wildlife Service. 1989. Recovery plan for the roseate tern-northeastern
                          population. U.S. Fish and Wildlife Service. Newton Corner, MA. 78 pp.

                  U.S. Dept. of the Interior. Minerals Management Service. 1974-1990a. Weekly reports, 1974-1990. New
                          Orleans, LA. Minerals Management Service, Gulf of Mexico OCS Region.

                  U.S. Dept of the Interior. Minerals Management Service. 1974-1990b. Monthly statistics and quarterly reports,
                          1974-1990. New Orleans, LA. Minerals Management Service, Gulf of Mexico OCS Region.

                  U.S. Dept. of the Interior. Minerals Management Service. 1984a. Environmental assessment for geological
                          and geophysical exploration activities on the outer continental shelf. September 1984. OCS Report
                          MMS 84-0051.

                  U.S. Dept. of the Interior. Minerals Management Service. 1984b. Federal offshore statistics: leasing exploration
                          production revenue. OCS Report MMS 84-0071. 123 pp.

                  U.S. Dept. of the Interior. Minerals Management Service. 1986. Oil spills, 1976-85; statistical report. OCS
                          Report/MMS 86-0085.

                  U.S. Dept. of the Interior. Minerals Management Service. 1987. Rigs-to-Reefs: the use of obsolete
                          petroleum structures as artificial reefs. New Orleans, LA. Minerals Management Service, Gulf of
                          Mexico OCS Region. OCS Report MMS 87-0015. 17 pp.

                  U.S. Dept. of the Interior. Minerals Management Service. 1988. North Atlantic oil and gas lease Sale 96, draft
                          environmental impact statement. OCS EIS/EA MMS 88-"l. 613 pp.










                                                                                                                     VI-57

               U.S. Dept of the Interior. Minerals Management Service. 1990a. Federal offshore statistics: 1989. OCS
                       Report MMS 9O4W2.104 pp.

               U.S. Dept. of the Interior. Minerals Management Service. 1990b. Mineral revenues, 1989. U.S. Dept. of the
                       Interior, Minerals Management Service. Washington, DC: U.S. Government Printing Office.

               U.S. Dept. of the Interior. Minerals Management Service. 1990c. Study of inert pollutants in Western
                       Planning Area. Internal Report.

               U.S. Dept. of Transportation. Coast Guard. 1989a. Boating statistics, 1988. COMDTPUB P16754.1. p. 4.

               U.S. Dept. of Transportation. Coast Guard. 1989b. Personal communication with Galveston Marine Safety
                       Office.


               U.S. Environmental Protection Agency. 1991. Economic impact analysis of proposed effluent limitation
                       guidelines and standards for the offshore oil and gas industry. Prepared by Eastern Research Group,
                       Inc. EPA 440/2-91-001.

               U.S. Travel Data Center. 1987. The economic impact of travel on Mississippi counties, 1986. Prepared for
                       the Mississippi Dept of Economic Development by the U.S. Travel Data Center's county travel
                       economic impact model (CTEIM).

               University of Texas at Austin. 1987. Economic impact of travel on Texas counties, 1986. Smith, J. and E.
                       Echeverri-Caffol, eds., Bureau of Business Research.

               Usie, L. 1989. Written communication. 1988 commercial fisheries landings by inshore water body. New
                       Orleans, LA- U.S. Dept. of Commerce, National Marine Fisheries Service, Statistics Division,
                       Landings Data. 8 pp.

               von Bodunden, G. 1988. Personal communication. Louisiana Dept. of Environmental Quality, Baton Rouge,
                       LAL

               Watson, W.G. 1989. Personal communication. Manager, Engineering, Louisiana Offshore Off Port (LOOP).

               Wells, J.T., S.J. Chinburg, and J.M. Coleman. 1983. Development of the Atchafalaya River Deltas: generic
                       analysis. Waterways Experiment Station, Vicksburg, MS. DACW 39-80-C-0082. 98 pp.

               Wells, R.S., A.B. Irvine, and M.D. Scott. 1980. The social ecology of inshore Odontocetes. In: Herman,
                       L.M., ed. Cetacean behavior: mechanisms and functions. New York, NY: John Wiley & Sons. pp.
                       263-317.


               White, W.A., T.R. CaInan, R.A. Morton, R.S. Kimble, T.G. Littleton, J.H. McGowen, H.S. Nance, and K.E.
                       Schinedes. 1986. Submerged lands of Texas, Brownsville-Harlingen area. Bureau of Economic
                       Geology, University of Texas. Austin, TX 138 pp.

               Williams, J., W.F. Grey, E.B. Murphy, and J.J. Crane. 1977. Drift bottle analysis of Eastern Gulf of Mexico
                       surface circulation. Memoirs of the Hourglass Cruises, Vol. IV, part III. Fla. Dept. of Natural
                       Resources, Marine Research Laboratory. 134 pp.

               Wilson, H. 1989. Personal communication, Tidewater Marine, Inc., New Orleans, LA.










               VI-58
               Wilson, R.D., P.H. Monaghan, A. Osanik, L.C. Price, and M.A. Rogers. 1973. Estimate of annual input of
                       petroleum to the marine environment from natural marine seepage. Trans. Gulf Coast Assoc. Geol.
                       Soc. 23:182-193.

               Winters, K and P.L. Parker. 1977. Water-soluble components of crude offs, fuel oils, and used crankcase oils.
                       In: Proceedings 1977 Oil Spill Conference, New Orleans, LA, March 8-10, 1977. Washington, DC-
                       American Petroleum Institute. pp. 579-582.

               Woodward-Clyde Consultants and Continental Shelf Associates, Inc. 1984. Southwest Floridashelf ecosystems
                       study - year 2. Report to the Minerals Management Service, Contract No. 14-12-0031-29144.

               Zobell, C. 1973. Microbial degradation of oil: present status, problems, and perspectives. From a workshop
                       held at Georgia State University, Atlanta, GA. Eds. O.G. Ahearn and S.P. Meyers, LSU Press
                       Publications.


                       These references are available for review by the public in the Gulf of Mexico OCS 'Region's library.
               Most of these references may also be found in public or university libraries. The library will, upon request,
               provide assistance to anyone having difficulty locating any of these publications.

               Contact:  Librarian
                         Minerals Management Service
                         Gulf of Mexico OCS Region
                         1201 Elmwood Park Boulevard
                         New Orleans, Louisiana 70123-2394
                         (504) 736-2522 or FrS 686-2522

























    SECTION VII
    PREPARERS                      VI'L







               V11. PREPARERS

               Joseph A- Christopher, Chief, Environmental Assessment Section
               Mary R. Bartz, Coastal Unit Chief, Supervisory Environmental Protection Specialist
               Dennis L. Chew, Offshore Unit Chief, Supervisory Environmental Protection
                  Specialist, Coordinator


               Darice K Breeding, Environmental Protection Specialist
               Patricia R. Bryars, Statistical Assistant
               Ann Scarborough Bull, Biologist
               Linda Castafio-Velez, Economist
               Elmo J. Cooper, Visual Information Specialist
               T. Gerald Crawford, Supervisory Petroleum Engineer
               Janet Y, Diaz, Secretary
               Michael E. Dorner, Jr., Regional Editor
               Norman L. Froomer, Physical Scientist
               Gary D. Goeke, Supervisor, Information Management Team
               John R. Greene, Archaeologist
               Charles W. Hill, Jr., Natural Resource Specialist
               Bonnie Laborde Johnson, Physical Scientist
               Alexis Lugo-FernAndez, Physical Oceanographer
               Anne M. Maranto, Clerk-Typist
               Deborah H. Miller, Technical Publications Editor
               Gail B. Rainey, Natural Resource Specialist
               Villere C. Reggio, Jr., Outdoor Recreation Planner
               John L. Rodi, Economist
               R. Mark Rouse, Environmental Protection Specialist
               Gary J. Rutherford, Geologist
               Joseph C. Souhlas, Visual Information Specialist
               Wilfred W. Times, Visual Information Specialist
               Darcel D.Waguespack, Cartographic Technician


























    SECTION VIII
    GLOSSARY                      vil,










                                                                                                                             VIII-3


                 V111. GLOSSARY

                 Acute -- Sudden, short term, severe, critical, crucial, intense, but usually of short duration.

                 Aliphatic -- Of or pertaining to organic compounds characterized by a chain of carbon atoms; subgroups of
                          such compounds are alkanes, alkenes, and alkynes, and their cyclic analogs.

                 Analysis area -- An OCS subplanning area or other OCS area plus the adjacent coastal subarea.

                 Anoxia -- Absence of oxygen.

                 Anthropogenic -- Coming from human sources, relating to the effect of humankind on nature.

                 Anticline -- An upfold or arch of stratified rock in which the beds or layers bend downward in opposite directions
                          from the crest or axis of the fold.

                 Aphotic zone -- Zone where the levels of light entering through the surface are not sufficient for photosynthesis
                          or for animal response.

                 API gravity - A standard adopted by the American Petroleum Institute for expressing the specific weight of
                          oil, also known as the Baume gravity. The API gravity equals [(141.5/specific gravity at WF) - 131-51.

                 Areas of high marine productivity -- Areas such as open bays, estuaries, and sounds that are used by finfish and
                          shellfish as nursery and/or spawning grounds and may contain oyster reefs; nearshore Gulf areas that
                          are important harvest grounds for menhaden and industrial bottomfish and/or finfish and shellfish
                          spawning grounds; and coral areas in the vicinity of the Florida Keys.

                 Aromatic -- Applied to a class of organic compounds containing benzene rings or benzenoid structures.

                 Asphaltene -- Any of the dark, solid constituents of crude oils that are soluble in carbon disulfide but insoluble
                          in paraffin napthas.

                 Attainment area -- An area that is shown by monitored data or that is calculated by air quality modeling no to
                          exceed any primary or secondary ambient air quality standards established by the USEPA.

                 Barrel (bbl) -- A volumetric unit used in the petroleum industry equivalent to 42 U.S. gallons or 158.99 liters.

                 Base Case -- An estimate of the resources expected to be leased, developed, and produced, assuming that
                          hydrocarbons exist in the area (i.e., a conditional estimate), and an estimate of the exploration,
                          development, production, and transportation activities appropriate to that level of resources.

                 Basin -- A depression of the earth in which sedimentary materials accumulate or have accumulated, usually
                          characterized by continuous deposition over a long period of time; a broad area of earth beneath which
                          the strata dip, usually from the sides toward the center.

                 Biological opinion -- An appraisal from either FWS or NMF`S evaluating the impact of a proposed activity on
                          endangered and threatened species.

                 Block -- A geographical area, as portrayed on an official MMS protraction diagram or leasing map, that contains
                          approximately nine square miles (2,331 ha or 5,760 ac).










                VIII-4

                Blowout -- An uncontrollable flow of fluids from a wellhead or wellbore. Unless otherwise specified, a flow of
                         fluids from a flowline is not considered a blowout as long as the wellhead control valves can be
                         automatically or manually activated. If the wellhead control valves become inoperative, the flow is
                         classified as a blowout.

                Blowout preventer (BOP) -- A stack or an assembly of heavy-duty valves attached to the top of the casing to
                         control well pressure.

                Bunker fuel -- Heavy residual fuel oil used in ship boilers and in large heating and generating plants.

                Caprock - A disk-like plate over all or part of the top of most salt domes in the Gulf Coast States, composed
                         of anhydrite, gypsum, limestone, and occasionally sulfur. Caprock may also be a comparatively
                         impervious stratum immediately overlying an oil- or gas-bearing rock in an anticline.

                Centistoke -- A derived unit of viscosity in customary use as a measure of a fluid's resistance to flow or change
                         of form by internal forces of friction.

                Central Planning Area (CPA) -- The sale area south from territorial sea at approximately 87o45'W. longitude
                         to approximately 290N. latitude, thence west to approximately 87o55'W. longitude, thence south to
                         approximately MoN. latitude, thence west to approximately 91055W longitude, except that between
                         approximately 88023W longitude and 9100W longitude the boundary is the U.S.-Mexico provisional
                         maritime boundary; thence north to approximately 27055'N. latitude, thence generally west to
                         approximately 93o25'W. longitude, thence northwest to the juncture of the territorial sea at
                         approximately 93o5O'W. longitude, thence east along the territorial sea to the point of origin.

                Cetacean -- A marine mammal such as whales, dolphins, porpoises, and related forms.

                Coastal subareas -- Discrete analysis areas (consisting of several counties/parishes) within the larger offshore
                         coastal areas.

                Coastal waters -- Inshore waters within the geographical areas defined by each State's. Coastal Zone
                         Management Program.

                Coastal wetlands -- Forested and nonforested habitats, mangroves, and all marsh islands that are exposed to
                         the Gulf of Mexico waters. Acreage and shoreline distances for these categories can be found on Visual
                         No. 14 of Final EIS 94/98/102. Included in forested wetlands are hardwood hammocks, cypress-tupelo
                         gum swamps, and fluvial vegetation/bottomland hardwoods. Nonforested wetlands include fresh,
                         brackish, and salt marshes. These areas directly contribute to the high biological productivity of coastal
                         water by input of detritus and nutrients, by providing nursery and feeding areas for shellfish and finfish,
                         by serving as habitat for many birds and other animals, and by providing waterfowl hunting and fur
                         trapping.

                Coastal zone -- The coastal waters (including the lands therein and thereunder) and the adjacent shorelands
                         (including the waters therein and thereunder), strongly influenced by each other and in proximity to
                         the shorelines of the several coastal states; the zone includes islands, transitional and intertidal areas,
                         salt marshes, wetlands, and beaches and extends seaward to the outer limit of the United States
                         territorial sea. The zone extends inland from the shorelines only the extent necessary to control
                         shorelands, the uses of which have a direct and significant impact on the coastal waters. Excluded from
                         the coastal zone are lands the use of which is by law subject to the discretion of or which is held in trust
                         by the Federal Government, its officers, or agents.

                Coelobite -- Organisms that live in the cavities of reefs--cryptic organisms. They are normally small and
                         encrusting and include foraminifers.











                                                                                                                              VIII-5

                Commingling -- The intentional mixing of petroleum products having similar specifications.

                Completion    Conversion of a development well or an exploratory well into a production well of oil and/or gas.

                Condensate    Liquid hydrocarbons produced with natural gas; they are separated from the gas by cooling and
                         various other means. Condensate generally has an API gravity of 50o-1200 and is water-white, straw, or
                         bluish in color.

                Conditional resources -- Assessment of oil or gas resources under the assumption that economically recoverable
                         resources exist within the area of interest.

                Continental margin -- The ocean floor that lies between the shoreline and the abyssal ocean floor. It includes
                         the provinces of the continental shelf, continental slope, and continental rise.

                Continental shelf -- The continental margin province that lies between the shoreline and the abrupt change in
                         slope called the shelf edge, which generally occurs around a water depth of 200 in. The shelf is
                         characterized by a gentle slope (ca. 0.1o).

                Continental slope -- The continental margin province that lies between the continental shelf and continental
                         rise, characterized by a steep slope (ca. 30-60) and located around depths of 3,000-4,000 in.

                Contingency plan -- A plan for possible offshore emergencies prepared and submitted by the oil or gas operator
                         as part of the Plan of Development and Production.

                Critical habitat -- Specific areas essential to the conservation of a protected species and that may require special
                         management considerations or protection.

                Crude oil -- An oily, flammable bituminous liquid that occurs in many places in the upper strata of the earth,
                         either in seepages or in reservoirs; essentially a complex mixture of hydrocarbons of different types
                         with small amounts of other substances; as distinguished from refined oil manufactured from it.

                Deferral -- Action taken by the Secretary of the Interior at the time of the Area Identification to remove certain
                         areas/blocks from the proposed sale. Deferred areas could receive environmental description in the EIS
                         but are not assessed as alternatives.

                Deletion alternative -- An option available to the Secretary of the Interior to alter the proposed action in
                         Alternative A by deleting areas/blocks from the sale. This action would normally take place after
                         completed analysis is available in the Final EIS.

                Delineation well -- A well that is drilled for the purpose of delineating a discovered oil or gas reservoir, thereby
                         enabling the lessee to determine whether to proceed with development and production.

                Designated environmental preservation areas -- Gulf of Mexico shorefront areas that have been established
                         for the quality and significance of their natural environments. They have been legislatively,
                         administratively, or privately protected from the developmental influences of humans and are managed
                         solely for the preservation, understanding, and appreciation of their natural attributes. Included are
                         National Parks and Preserves, National and State Wilderness Areas, National Marine and Estuarine
                         Sanctuaries, National Landmarks, Wildlife Sanctuaries, Florida Aquatic Preserves, and Environmentally
                         Endangered Lands.

                Detritivores -- Animals whose diet consists of detritus and the microbial fauna attached to detrital particles.

                Detritus -- Particulate organic matter originating primarily from the physical breakdown of dead animal and
                         plant tissue (may also include the breakdown of inorganic material).










                  VIII-6



                  Development -- Activities that take place following discovery of minerals in paying quantities, including
                           geophysical activity, drilling, platform construction, and operation of all onshore support facilities, and
                           that are for the purpose of ultimately producing the minerals discovered.

                  Development/Production Plan (DPP) -- A plan describing the specific work to be performed, including all
                           developmentand production activities that the lessee(s) propose(s) to undertake during the time period
                           covered by the plan and all actions to be undertaken up to and including the commencement of
                           sustained production. The plan also includes descriptions of facilities and operations to be used, well
                           locations, current geological and geophysical information, environmental safeguards,, safety standards
                           and features, time schedules,and other relevant information. Under 30 CFR 250.34-2, all lease operators
                           are required to formulate and obtain approval of such plans by the Director of the Minerals
                           Management Service before development and production activities commence.

                  Development/production service base -- A service base that is used in support of offshore development and
                           production activity.

                  Developmentwell -- A well drilled to a known producing formation in a previously discovered field; distinguished
                           from a wildcat or exploratory well and from an offset well.

                  Diapir -- A piercing fold; an anticlinal fold in which a mobile core, such as salt, has broken through the more
                           brittle overlying rocks.

                  Discharge -- Something that is emitted; flow rate of a fluid at a given instant expressed as volume per unit of
                           time.


                  Discovery -- The initial find of significant quantities of fluid hydrocarbons on a given field on a given lease.

                  Dispersion -- A distribution of finely divided particles in a medium.

                  Dome -- A roughly symmetrical upfold, the beds dipping in all directions, more or less equally, from a point;
                           any structural deformation characterized by local uplift approximately circular in outline, for example,
                           the salt domes of Louisiana and Texas.

                  Drilling mud -- A special mixture of clay, water or refined oil, and chemical additives pumped downhole through
                           the drill pipe and drill bit. The mud cools the rapidly rotating bit, lubricates the drill i ipe as it turns in
                           the well bore, carries rock cuttings to the surface, serves to keep the hole from crumbling or collapsing,
                           and provides the weight or hydrostatic head to prevent extraneous fluids from entering the well bore and
                           to control downhole pressures that may be encountered (drilling fluid).

                  Drill ship -- A self-propelled, self-contained vessel equipped with a derrick amidship for drilling wells in
                           deepwater.

                  Eastern Planning Area (EPA) -- The sale are south from territorial sea at approximately 8745W longitude to
                           approximately 29oN. latitude, thence west to approximately 87o55'W. longitude, thence south to
                           approximately 26oN. latitude, thence east to approximately 85055'W. longitude, thence south to the
                           limit of U.S. jurisdiction, thence southeast to approximately 83055'W. longitude at 24olst. latitude, thence
                           east to 830W. longitude, thence north to the limits of the territorial sea, thence east to approximately
                           82025'W. longitude, thence north and east along the territorial sea abutting the Florida Keys, thence
                           north and east to approximately 81o55'W. longitude, thence North to the limits of the territorial sea,
                           thence North and West along the territorial sea to the point of origin.











                                                                                                                             VIII-7

                Economically recoverable resource estimate -- An assessment of hydrocarbon potential that takes into account
                         the physical and technological constraints on production and the influence of costs of exploration and
                         development and market price on industry investment in OCS exploration and production.

                Effluent -- The liquid waste of sewage and industrial processing.

                Emissionoffset -- Emission reductions obtained from facilities, either onshore or offshore, other than the facility
                         or facilities covered by the proposed Exploration Plan or Development and Production Plan.
                Endangered and threatened species -- Those species identified in 43 FR 238 (December 11, 1978) and
                         subsequent publications.

                Environmental impact statement (EIS) -- A statement required by the National Environmental Policy Act of
                         1969 (NEPA) or similar State law in relation to any major action significantly affecting the environment;
                         an NEPA document.

                Essential habitat -- Specific areas crucial to the conservation of a species and that may necessitate special
                         considerations.

                Estuary -- Sernienclosed coastal body of water that has a free connection with the open sea and within which
                         seawater is measurably diluted with fresh water.

                Eutrophic(ation) -- An enrichment of nutrients in the water column by natural or artificial methods With an
                         increase of respiration, which may create an oxygen deficiency.

                Exclusive Economic Zone (EEZ) -- The maritime region adjacent to the territorial sea, extending 200 nautical
                         miles from the baseline of the territorial sea, in which the United States has exclusive rights and
                         jurisdiction over living and nonliving natural resources.

                Exploration -- The process of searching for minerals. Exploration activities include: (1) geophysical surveys,
                         where magnetic, gravity, seismic, or other systems are used to detect or infer the presence of such
                         minerals, and (2) any drilling, except development drilling, whether on or off known geological
                         structures. Exploration also includes the drilling of a well in which a discovery of oil or natural gas in
                         paying quantities is made and the drilling, after such a discovery, of any additional well that is needed
                         to delineate a reservoir and to enable the lessee to determine whether to proceed with development
                         and production.

                Exploration Plan (EP) -- A plan based on available relevant information about a leased area that identified, to
                         the maximum extent possible, the potential hydrocarbon accumulations and the wells that the lessee(s)
                         propose(s) to drill to evaluate the accumulations within the entire area of the lease(s) covered by the
                         plan. Under 30 CFR 250.34-1, lease operators are required to formulate and obtain approval of such
                         plans by the Director of Minerals Management Service before significant exploration activities may
                         commence.


                Exploratory well -- A well drilled in unproven or semi-proven territory for the purpose of ascertaining the
                         presence underground of a commercial petroleum or natural gas deposit.

                Exposed coastline -- Shoreline areas that can be directly impacted by activities in OCS waters.

                Fault    A fracture in the earth's crust accompanied by a displacement of one side of the fracture with respect
                         to the other.

                Field    An area within which hydrocarbons have been concentrated and trapped in economically producible
                         quantities in one or more structural or stratigraphically related reservoirs.










                VIII-8


                Florida hammocks -- Areas of higher elevation than their surroundings and characterized by hardwood and/or
                        palm vegetation.

                Frasch technique -- Technique used for mining sulphur whereby heated seawater injected into the
                        mineral-bearing formation results in melting of the elemental sulphur. Air pumped to the level of the
                        molten sulphur lifts the sulphur to the surface.

                Fugitive emissions -- Emission into the atmosphere that could not reasonably pass through a stack, chimney,
                        vent, or other functionally equivalent opening.

                Gathering lines -- Pipelines and flowlines used to bring oil from production leases by separate lines to a central
                        point in the production complex or to a trunk pipeline.

                Geochem ical -- Of or relating to the science dealing with the chemical composition of and the actual or possible
                        chemical changes in the crust of the earth.

                Geologic hazard -- A naturally occurring or manmade geologic condition or phenomenon that presents a risk
                        or is a potential danger to life and property. Examples include subsidence and marine slides.

                Geomorphology -- The science of surface landforms and their interpretation on the basis of geology and climate.

                Geophysical -- Of or relating to the physics of the earth, especially the measurement and interpretation of
                        geophysical properties of the rocks in an area.

                Geophysical survey -- The exploration of an area during which geophysical properties and relationships unique
                        to the area are measured by one or more geophysical methods.

                Habitat -- A specific type of place that is occupied by an organism, a population, or a community.

                Herbivores    Animals whose diet consists of plant material.

                High Case     An estimate of a significantly higher level of resource recovery and attendant exploration and
                        development activity, which could result from leasing more acreage than may occur in the Base Case
                        or which could result from the discoveries of larger oil and gas accumulations than estimated under
                        the Base Case assumptions.

                High density offshore shellfish areas -- Nearshore areas known to have the highest concentrations of
                        commercially important shrimp, spiny lobster, and stone crab.

                Hydrocarbon -- Any of a large class of organic compounds containing primarily carbon and hydrogen.
                        Hydrocarbon compounds are divided into two broad classes: aromatic and aliphatics. They occur
                        primarily in petroleum, natural gas, coal, and bitumens.

                Hypoxia -- Depressed levels of dissovled oxygen in waters, usually resulting in decreased metabolism.

                Incidental take -- Takings that result from, but are not the purpose of, carrying out an otherwise lawful activity
                        conducted by the Federal agency or applicant.


                Industry infrastructure -- The facilities associated with oil and gas development, e.g., refineries, gas processing
                        plants, etc.

                Interaction -- An event during which a resource comes in contact with and is affected by an impact- producing
                        factor.










                                                                                                                           VIII-9



                Jack-up rig -- A barge-like, floating platform with legs at each corner that can be lowered to the sea bottom to
                         raise the platform above the water.

                Landfall  The site at which a marine pipeline comes to shore.

                Landfill  Location where disposal of solid waste occurs by burying in layers of earth in low ground.

                Land segment -- A subarea, usually consisting of one or more counties or parishes, within the coastal subarea.

                Land use -- The function for which people employ an area of land.

                Lay barge -- A shallow-draft, barge-like vessel used in the construction and laying of underwater pipelines.

                Lease -- Any form of authorization that is issued under Section 8 or maintained under Section 6 of the Outer
                         Continental Shelf Lands Act and that authorizes exploration for, and development and production of,
                         minerals.

                Lease sale -- The competitive auction of leases granting companies or individuals the right to explore for and
                         develop certain minerals under specified conditions and periods of time.

                Lease term -- For oil and gas leases, a period of either 5 years or up to 10 years (when a longer period is
                         necessary to encourage exploration and developmentin areas becauseof unusually deep water orother
                         adverse conditions (see primary term)).

                Lessee -- A party authorized by a lease, or an approved assignment thereof, to explore for and develop and
                         produce the leased deposits in accordance with regulations at 30 CFR 250.

                Major shorefront recreational beaches -- Those frequently visited sandy areas along the shorefront exposed to
                         the Gulf of Mexico that support a multiplicity of recreational activity, most of which is focused at the
                         land-water interface. Included are National Seashores and other selected areas in the National Parks
                         System, State Park and Recreational Areas, countyand local parks, urban beachfronts, and private resort
                         areas.


                Marshes -- Persistent, emergent nonforested wetlands characterized by vegetation consisting predominantly of
                         cordgrasses, rushes, and cattails.

                Militarywarning area -- An established area within which the public is warned that military activities take place.


                Minerals -- As used in this document, minerals include oil, gas, sulphur, and associated resources, and all other
                         minerals authorized by an Act of Congress to be produced from public lands as defined in Section 103
                         of the Federal Land Policy and Management Act of 1976.

                Nearshore waters -- Offshore, open waters that extend from the shoreline out to the limit of the territorial seas
                         (12 nautical miles).

                Nepheloid -- A layer of water near the bottom that contains significant amounts of suspended sediment causing
                         an increase of turbidity.

                Nonattainment area -- Any area that is shown by monitored data or that is calculated by air quality modeling
                         to exceed any primary or secondary ambient air quality standards established by the USEPA.










                 Vill-10

                 OCS program activities -- All oil and gas activities occurring Gulfwide during the life of the proposals as a result
                          of past, proposed, and future sales in the OCS.
                 Offloading -- Another name for unloading; offloading refers more specifically to liquid cargo, crude oil, and
                          refined products.

                 Offshore marine recreational fishing -- Hook-and-line sport fishing for fun, food, and occasional incidental
                          profit, inclusive of spearfishing, from a boat seaward of the beach in the Gulf of Me7dco.

                 Operational discharge -- A release of oil that is part of the routine operations of a function.
                 Operator -- An individual, partnership, firm, or corporation having control or management of operations on a
                          leased area or portion thereof The operator may be a lessee, designated agent of the lessee, or holder
                          of operating rights under an approved operating agreement

                 Organic matter -- Material derived from living plant or animal organisms.
                 Outer Continental Shelf (OCS) -- All submerged lands that comprise the continental margin adjacent to the
                          United States and seaward of State offshore lands.

                 Penaeids    Chiefly warm water and tropical prawns belonging to the family Penaeidae-
                 Plankton    Passively floating or weakly motile aquatic plants and animals.
                 Platform    A steel or concrete structure from which offshore development wells are drilled.
                 Poisson process -- A process that occurs as discrete and independent trials with a low probability of success (p)
                          in each trial but with a large number of trials (N) such that the product Np = a has a moderate size.
                          The probability of having successes is given by

                                                             P (n) = ane@a; n = 0, 1, 2, 3....
                                                                        n!

                          The area under the curve P(n) is mostly concentrated around the integers near n = EL. It can also be
                          shown that if in N trials the total observed number of successes is T than a - T/N.

                 Porous   Containing void spaces that may be occupied by fluids.

                 Potable   Suitable for drinking.
                 Primary production -- Organic material produced by photosynthetic or chemosynthetic autotrophs organisms.
                 Primary term -- The initial period of oil and gas leases, normally 5, 8, or 10 years (see lease term).
                 Production -- Activities that take place after the successful completion of any means for the removal of minerals,
                          including such removal, field operations, transfer of minerals to shore, operation monitoring,
                          maintenance, and workover drilling.
                 Production curve -- A curve plotted to show the relation between quantities produced during definite consecutive
                          time intervals.

                 Production schedule -- A percentage distribution intended to show quantities of oil or gas produced over a
                          consecutive time interval.











                                                                                                                            VIII-11

                Production well --A well that is drilled for the purpose of producing oil or gas reserves. It is sometimes termed
                         development well.

                Province -- An area throughout which geological conditions have been similar or that is characterized by
                         particular structural, petrographic, or physiographic features.

                Recoverable reserves -- The portion of the identified oil or gas resource that can be economically extracted
                         under current technological constraints.

                Recoverable resource estimate -- An assessment of oil and gas resources that takes into account the fact that
                         physical and technological constraints dictate that only a portion of resources can be brought to the
                         surface.

                Refining -- Fractional distillation, usually followed by other processing (for example, cracking).

                Relief -- The elevations or inequalities of a land surface.

                Reserves -- Identified oil or gas resources.

                Reservoir -- An accumulation of hydrocarbons that is separated from any other such accumulation.

                Rig -- A structure used for drilling an oil or gas well.

                Right-of-way -- A legal right of passage, an easement; the specific area or route for which permission has been
                         granted to place a pipeline and ancillary facilities and for normal maintenance thereafter.

                Risked, economically recoverable resource estimate -- An assessment of oil or gas resources that has been
                         modified to take into account: (1) physical and technological constraints on production; (2) the influence
                         of the costs of exploration and development and market price on industry investment in OCS exploration
                         and production; (3) and the uncertainty of the estimate and to account for the possibility that
                         economically recoverable resources may not be found within the area of interest.

                Rookery -- The nesting or breeding grounds of gregarious (i.e., social) birds or mammals; also a colony of such
                         birds or mammals.

                Royalty -- A share of the minerals produced from a lease paid in either money or in kind to the Treasury
                         Department by the lessee.

                Saltwater intrusion -- Phenomenon occurring when a body of saltwater; because of its greater density, invades
                         a body of freshwater, occurs in either surface or groundwater sources.
                Sciaenids -- Fishes belonging to the croaker family (Sciaenidae).
                Seagrass beds -- More or less continuousmats of submerged, rooted, marine, flowering vascular plants occurring
                         in shallow tropical and temperate waters. Seagrass beds provide habitat, including breeding and feeding
                         grounds, for adults and/orjuveniles of many of the economically important shellfish and finfish. As such,
                         this habitat type is especially sensitive to oil-spill impacts.
                Sediment -- Material deposited (as by water, wind, or glacier) or a mass of deposited material.
                Sedimentary rocks -- Rock formed of mechanical, chemical, or organic sediment.
                Seeps--petroleum -- Gas or oil that reaches the surface along bedding planes, fractures, unconformities, or fault
                         planes through connected porous rocks.











                 VIII-12



                 Seismic -- Pertaining to, characteristic of, or produced by earthquakes or earth vibration; having to do with
                          elastic waves in the earth.

                 Sensitive coastal habitats -- Coastal habitats susceptible to damage from off- and gas-related OCS activities.

                 Sensitive offshore area -- An area containing species, populations, communities, or asseinriblages of living
                          resources, to which normal oil and gas exploration and development activities may cause irreparable
                          damage, including interference with established ecological relationships.

                 Shunting -- A method used in offshore oil and gas drilling activities where expended drilling cuttings and fluids
                          are discharged near the ocean seafloor.

                 Single point mooring (SPM) -- Offshore anchoring and loading or unloading point connected to shore by an
                          undersea pipeline.

                 Sour oil -- Crude oil containing significant quantities of hydrogen sulfur gas.

                 Stratigraphic trap -- A geologic feature that includes a reservoir, capable of holding oil or gas, that is formed
                          from a change in the character or extent of the reservoir rock. Such a trap is harder to identify because
                          it is not dependent on structural closure and is thus not readily revealed by geological or geophysical
                          surveys.

                 Suliplanning area -- A discrete subarea within the larger offshore planning area.

                 Subsea completion -- A self-contained unit to carry men from a tender to the ocean bottom and enable them
                          to install, repair, or adjust wellhead connections in a dry, normal atmosphere.

                 Subsea complex -- A development well in which the assembly of valves, pipes, and fittings used to control the
                          flow of oil or gas is located on or near the ocean floor.

                 Subsidence -- A sinking of a part of the earth's crust.

                 Summary report -- A document prepared by the Department of the Interior pursuant to 30 CFR 252.4 that is
                          intended to inform affected State and local governments as to current OCS reserve estimates, projections
                          of magnitude and timing of development, transportation planning, and general location and nature of
                          nearshore and onshore facilities.

                 Supply boat -- A vessel that ferries food, water, fuel, and drilling supplies and equipment to a rig and returns
                          to land with refuse that cannot be disposed of at sea.

                 Sweet crude -- Crude oil containing very little sulfur or sulfur compounds and having a good odor.

                 Sweet gas -- Natural gas free of significant amounts of hydrogen sulfide (HS) when produced.

                 Taking -- To harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, collect, or attempt to engage in any
                          such conduct (including, but not inclusive of actions that induce stress, adversely impact critical habitat,
                          or result in adverse secondary or cumulative impacts).

                 Total suspended solids -- The total content of suspended and dissolved solids in water.

                 Trunk line -- A pipeline for the transportation of oil and or gas from producing areas to refineries or terminals.











                                                                                                                        VIII-13


              Turbidities -- High-density currents carrying nearshore deposits consisting of coarse, unsorted clastic deposits
                       alternating with uniform fine-grain deposits out into the ocean.

              Turbidity -- Reduced water clarity resulting from the presence of suspended matter.

              Undiscovered resources -- Quantities of oil and gas estimated to exist outside known fields.

              Unit -- Administrative consolidation of OCS leases held by one or more companies, but explored, developed,
                       and/or produced as one lease by one operator for purposes of conservation, eliminating unnecessary
                       operations and/or maximizing resources recovered.

              Vascular plants -- Plants containing food- and water-conducting structures; higher plants that reproduce by
                       seeds.


              Volatile organic compound (VOC) -- Any organic compound that is emitted to the atmosphere as a vapor.

              Water test areas -- Areas established within the Eastern Gulf where research, development, and the testing of
                       military planes, ships, and weaponry take place.

              Weathering -- The aging of oil due to its exposure to the atmosphere, causing marked alterations in its physical
                       and chemical makeup.

              Western Planning Area (WPA) -- The sale area east from the territorial sea along the U.S.-Mexico provisional
                       maritime boundary to approximately 25045'N. latitude, thence along approximately 260N. latitude to
                       approximately 91055W longitude, thence north to approximately 27055'N. latitude, thence generallywest
                       to approximately 93o25'W. longitude, thence northwest to the juncture of the territorial sea at
                       approximately 93*50'W. longitude, thence along the territorial sea to the point of origin.

              Wetlands -- Areas periodically inundated or saturated by surface or groundwater and that support vegetation
                       typically adapted for life in saturated soil conditions.






























    SECTION IX
    APPENDICES                         I lAw












                                                                 Appendix A



                                                        Blocks Affected by the
                                              Topographic Features Stipulations
                                       in the Central and Western Gulf of Mexico











                                                                                                                     A-3


                                                        Centml Gulf of MeAco


                  A total of 167 blocks in the Central Gulf would be affected by the topographic features stipulation, 105 of
               which are currently leased. The blocks affected, leasing status, and affected bank follow (as of January 31,
               1992).

                                                    West Cameron, South Addition

                       Block                        OCS-G No. (if leased)               Bank

                       569                                9427                          29 Fathom
                       570                                5188                          29 Fathom
                       589                                5352                          29 Fathom
                       590                                9430                          29 Fathom
                       591                                                              29 Fathom
                       592                                                              29 Fathom
                       611                                                              29 Fathom
                       612                                2557                          29 Fathom and MacNeil
                       613                                3286                          MacNeil
                       614                                                              MacNeil
                       633                                2238                          MacNeil
                       634                                10603                         Rankin
                       635                                12811                         Rankin
                       636                                                              Bright
                       637                                                              Bright
                       638                                2026                          Bright
                       645                                3973                          Geyer
                       646                                                              Geyer
                       648                                4268                          Bright
                       649                                                              Bright
                       650                                                              Bright
                       651                                                              Bright
                       652                                                              Rankin and Bright
                       653                                12812                         Rankin
                       654                                                              Rankin
                       655                                                              Rankin and Bright
                       656                                11819                         Bright
                       657                                11820                         Bright
                       658                                                              Bright
                       659                                                              Bright
                       660                                11821                         Bright
                       661                                                              Bright
                       662                                                              Bright and Rankin
                       663                                12813                         Rankin


                                                     East Cameron, South Addition

                       Block                        OCS-G No. (if leased)               Bank

                       361                              10639                           McGrail
                       362                              11853                           McGrail










              A4


                                             East Cameron, South Addition (continued)

                      Block                      OCS-G No. (if leased)               Bank

                      363                               11854                        McGrail
                      377                                                            McGrail
                      378                               12856                        McGrail
                      379                                9486                        McGrail


                                                     Vermilion, South Addition

                      Block                      OCS-G No. (if leased)               Bank

                      284                                9508                        Sonnier
                      285                                                            Sonnier
                      286                               11883                        Sonnier
                      297                               11885                        Sonnier
                      298                               11886                        Sonnier
                      299                                8674                        Sonnier
                      300                               11887                        Sonnier
                      303                                                            Sonnier
                      304                               11889                        Sonnier
                      305                               11890                        Sonnier
                      306                               11891                        Sonnier
                      317                               11894                        Sonnier
                      318                                4427                        Sonnier
                      319                                                            Sonnier
                      320                                2087                        Sonnier
                      361                                                            Bouma
                      362                               10687                        Bourna
                      363                                9522                        Bourna
                      369                                2274                        Bouma
                      370                                2275                        Bouma
                      371                                9524                        Bouma
                      372                                                            Bourna
                      382                                                            Bourna and Rezak
                      383                                                            Bourna and Rezak
                      384                                                            Bourna
                      385                               12880                        Bourna
                      386                                2278                        Bourna
                      387                                                            McGrail
                      388                                                            McGrail
                      389                                                            McGrail
                      390                                                            McGrail
                      391                                9528                        McGrail and Bouma
                      392                                                            Bouma
                      393                                8677                        Bourna and Rezak
                      394                               11900                        Bouma and Rezak
                      395                               11901                        Rezak
                      396                                                            Rezak
                      403                                                            Rezak
                      404                                8678                        Rezak










                                                                                                                A-5

                                              Vermilion, South Addition (continued)

                     Block                       OCS-G No. (if leased)              Bank

                     405                                                            Rezak
                     406                                                            Rezak and Bouma
                     407                                11902                       Bouma
                     408                                 9532                       McGrail
                     409                                 9533                       McGrail
                     410                                11903                       McGrail
                     411                                10693                       Sidner and Rezak
                     412                                 6685                       Sidner and Rezak


                                                South Marsh Island, South Addition

                     Block                       OCS-G No. (if leased)              Bank

                     161                                 4809                       Alderdice
                     162                                                            Alderdice
                     163                                                            Alderdice
                     169                                 9554                       Alderdice
                     170                                                            Alderdice
                     171                                11921                       Alderdice
                     172                                11922                       Alderdice
                     173                                 2887                       Alderdice
                     176                                 5221                       Alderdice
                     177                                                            Alderdice
                     178                                 9555                       Alderdice
                     179                                 9556                       Alderdice
                     180                                 9557                       Alderdice
                     185                                 9559                       Alderdice and Parker
                     186                                 9560                       Alderdice and Parker
                     187                                                            Alderdice and Parker
                     188                                                            Alderdice and Parker
                     193                                                            Parker
                     194                                11926                       Parker
                     195                                11927                       Parker
                     196                                 9562                       Parker
                     197                                11928                       Parker
                     200                                                            Parker
                     201                                                            Parker
                     202                                                            Parker
                     203                                                            Parker
                     204                                                            Parker


                                                  Eugene Island, South Addition

                     Block                       OCS-G No. (if leased)              Bank

                     335                                12927                       Fishnet
                     355                                                            Fishnet
                     356                                                            Fishnet










               A-6

                                               Eugene Island, South Addition (continued)

                       Block                        OCS-G No. (if leased)               Block

                       381                                  8703                        Jakkula
                       382                                  9603                        Jakkula
                       383                                 10756                        Jakkula
                       390                                 11970                        Jakkula
                       391                                 11971                        Jakkula
                       397                                 11973                        Jakkula


                                                      Ship Shoal, South Addition

                       Block                        OCS-G No. (if leased)               Bank

                       325                                 10800                        Ewing
                       326                                 12956                        Ewing
                       327                                 12005                        Ewing
                       328                                 12006                        Ewing
                       329                                 10801                        Ewing
                       334                                 10804                        Ewing
                       335                                 12957                        Ewing
                       336                                                              Ewing
                       337                                  9633                        Ewing
                       338                                                              Ewing
                       339                                 12007                        Ewing
                       348                                 10807                        Ewing
                       349                                 12008                        Ewing
                       350                                  8716                        Ewing
                       351                                 12959                        Ewing
                       352                                 10808                        Ewing
                       353                                                              Ewing
                       356                                  5206                        Ewing
                       357                                 12960                        Ewing
                       358                                 12009                        Ewing
                       359                                 12010                        Ewing

                                                    South Timbalier, South Addition

                       Block                        OCS-G No. (if leased)               Bank

                       314                                                              Diaphus
                       315                                  8728                        Diaphus
                       316                                 10862                        Diaphus
                       317                                                              Diaphus

                                                      West Delta, South Addition

                       Block                        OCS-G No. (if leased)               Bank

                       147                                 10887                        Sackett











                                                                                                                   A-7

                                                West Delta, South Addition (continued)

                        Block                      OCS-G No. (if leased)               Bank

                        148                               12074                        Sackett


                                                            Green Canyon

                        Block                      OCS-G No. (if leased)               Bank

                        4                                 12180                        Jakkula
                        5                                 12181                        Jakkula
                        6                                   6987                       Jakkula
                        7                                 13152                        Jakkula
                        49                                                             Jakkula
                        50                                  7989                       Jakkula
                        90                                11020                        Sweet


                                                             Ewing Bank

                        Block                      OCS-G No. (if leased)               Bank

                        903                                 5803                       Ewing
                        932                                                            Jakkula
                        933                                                            Jakkula
                        944                                 5809                       Ewing
                        945                                                            Ewing
                        947                                 5803                       Ewing
                        975                                                            Jakkula
                        976                                                            Jakkula
                        977                                                            Jakkula


                                                          Mississippi Canyon

                        Block                      OCS-G No. (if leased)               Bank

                        316                                                            Sackett











                A-8



                                                           Western Gulf of Mvdco


             A total of 200 blocks in the Western Gulf would be affected by the topographic features stipulation, 113 of which
             are currently leased. The blocks affected, leasing status, and the affected bank follow (as of January 31, 1992).

                                                     North Padre Island, East Addition

                         Block                        OCS-G No. (if leased)                 Bank

                         A-30                                  8965                         Dream
                         A-31                                  8966                         Dream
                         A40                                   8967                         Dream
                         A-41                                  8968                         Dream
                         A-72                                 11213                         Blackfish Ridge
                         A-83                                 12408                         Mysterious
                         A-84                                 12409                         Mysterious

                                                               Mustang Island

                         Block                        OCS-G No. (if leased)                 Bank

                         A-3                                  11240                         North Hospital
                         A-4                                                                North Hospital and Hospital
                         A-9                                                                Southern
                         A-16                                  3011                         Southern


                                                       Mustang Island, East Addition

                         Block                        OCS-G No. (if leased)                 Bank

                         A-54                                 10176                         Small and Big Dunn Bars
                         A-61                                 13282                         Baker
                         A-62                                                               Baker
                         A-86                                 12427                         Baker and South Baker
                         A-87                                                               Baker and South Baker
                         A-95                                                               South Baker
                         A-117                                10184                         Aransas and North Hospital
                         A-118                                10185                         Aransas
                         A-136                                                              Aransas, Hospital, and
                                                                                              North Hospital
                         A-137                                                              Hospital

                                                         High Island, South Addition

                         Block                        OCS-G No. (if leased)                 Bank

                         A-446                                 2359                         Claypile
                         A-447                                 2360                         Claypile
                         A-448                                 2361                         Claypile
                         A-463                                                              Claypile











                                                                                                                        A-9

                                                High Island, South Addition (continued)

                       Block                        OCS-G No. (if leased)                 Bank

                       A-464                                                              Claypile
                       A-465                                 9123                         Claypile
                       A486                                  6227                         Stetson
                       A-487                                                              Stetson
                       A-488                                13337                         Stetson
                       A-501                                12580                         Stetson
                       A-502                                                              Stetson
                       A-503                                11387                         Stetson
                       A-512                                13338                         Stetson
                       A-513                                                              Stetson
                       A-514                                                              Stetson
                       A-527                                 9129                         Stetson
                       A-528                                                              Stetson
                       A-529                                 9130                         Stetson
                       A-534                                                              32 Fathom
                       A-535                                13340                         32 Fathom
                       A-573                                 2393                         West Flower Garden
                       A-578                                                              Applebaum
                       A-579                                                              Applebaum
                       A-580                                                              Applebaum
                       A-589                                12586                         Applebaum
                       A-590                                10304                         Applebaum
                       A-591                                                              Applebaum
                       A-596                                 2722                         West Flower Garden

                                              High Island, East Addition, South Extension

                       Block                        OCS-G No. (if leased)                 Bank

                       A-311                                                              29 Fathom
                       A-312                                 2409                         29 Fathom
                       A-327                                 2418                         29 Fathom
                       A-328                                                              29 Fathom
                       A-329                                11403                         29 Fathom
                       A-330                                 2421                         29 Fathom
                       A-331                                                              29 Fathom
                       A-332                                 2422                         29 Fathom
                       A-340                                 2426                         Coffee Lump
                       A-346                                                              MacNeil
                       A-347                                 9151                         MacNeil
                       A-348                                 9152                         MacNeil
                       A-349                                 2743                         MacNeil
                       A-350                                 2428                         MacNeil
                       A-351                                 2429                         MacNeil and East Flower Garden
                       A-352                                 9153                         East Flower Garden and MacNeil










                 A-10



                                         High Island, East Addition, South Extension (continued)

                         Block                      OCS-G No. (if leased)               Bank

                         A-353                                                          East Flower Garden
                         A-354                               9154                       East Flower Garden
                         A-355                               2745                       East Flower Garden
                         A-358                                                          Coffee Lump
                         A-359                                                          Coffee Lump
                         A-360                                                          Coffee Lump
                         A-361                               9155                       Coffee Lump and
                                                                                         West Flower Garden
                         A-362                                                          West Flower Garden
                         A-363                               9156                       West Flower Garden
                         A-364                                                          East and West Flower Garden
                         A-365                               2750                       East Flower Garden
                         A-366                                                          East Flower Garden
                         A-367                                                          East Flower Garden
                         A-368                               2433                       East Flower Garden,
                                                                                         Rankin, and MacNeil
                         A-369                               2751                       MacNeil and Rankin
                         A-370                               2434                       MacNeil and Rankin
                         A-371                               9157                       Rankin
                         A-372                               9158                       Rankin and MacNeil
                         A-373                               7367                       East Flower Garden,
                                                                                         Rankin, and MacNeil
                         A-374                              11405                       East Flower Garden
                         A-375                                                          East Flower Garden
                         A-376                               2754                       East Flower Garden
                         A-377                              11406                       East and West Flower Garden
                         A-378                                                          West Flower Garden
                         A-379                                                          West Flower Garden
                         A-380                                                          West Flower Garden
                         A-381                                                          West Flower Garden
                         A-382                               2757                       West Flower Garden
                         A-383                              11407                       West Flower Garden
                         A-384                               3316                       West Flower Garden
                         A-385                              10311                       West Flower Garden
                         A-386                               9159                       East and West Flower Garden
                         A-387                                                          East Flower Garden
                         A-388                              12592                       East Flower Garden
                         A-389                               2759                       East Flower Garden
                         A-390                               9161                       East Flower Garden and Rankin
                         A-391                               9162                       Rankin
                         A-392                              12593                       Rankin
                         A-393                              12594                       Rankin
                         A-394                                                          East Flower Garden
                         A-395                              13346                       East Flower Garden











                                                                                                                          A-11


                                          High Island, East Addition, South Extension (continued)

                        Block                         OIC;5-G No. (if leased)                Bank

                        A-396                                 12595                          East and West Flower Garden
                        A-397                                                                West Flower Garden
                        A-398                                                                West Flower Garden
                        A-399                                 13347                          West Flower Garden
                        A-400                                                                West Flower Garden
                        A-401                                 13348                          West Flower Garden
                        A-402                                                                West Flower Garden
                        A-403                                 13349                          East Flower Garden


                                                                 East Breaks


                        Block                         OCS-G No. (if leased)                  Bank

                        121                                                                  Applebaum
                        122                                   12596                          Applebaum
                        123                                                                  Applebaum
                        124                                                                  Applebaum
                        165                                     6280                         Applebaum
                        166                                   11413                          Applebaum
                        167                                   13351                          Applebaum
                        168                                   12598                          Applebaum
                        173                                   12600                          West Flower Garden
                        217                                                                  West Flower Garden


                                                                Garden Banks


                        Block                          OCS-G No. (if leased)                 Bank

                         26                                     9197                         McGrail
                         27                                                                  McGrail
                         28                                                                  McGrail
                         29                                                                  McGrail
                         30                                                                  Rezak and Sidner
                         31                                                                  Rezak and Sidner
                         33                                                                  Rezak and Sidner
                         61                                                                  Geyer
                         62                                                                  Geyer
                         63                                                                  Geyer
                         70                                     9200                         McGrail
                         71                                     9201                         McGrail
                         72                                   13363                          McGrail
                         73                                   13364                          McGrail
                         74                                                                  Sidner
                         75                                                                  Sidner
                         76                                                                  Sidner
                         77                                                                  Sidner
                         81                                                                  Parker
                         82                                                                  Parker











                  A-12


                                                                Garden Banks (continued)

                            Block                            OCS-G No. (if leased)                      Bank

                            83                                        11450                             Parker
                            84                                        11451                             Parker
                            85                                        10327                             Parker
                            95                                                                          East Flower Gar-den
                            96                                                                          East Flower Garden
                            97                                         9204                             East Flower Garden and Rankin
                            98                                         9204                             Rankin
                            102                                       10328                             Bright
                            103                                       12630                             Bright
                            104                                                                         Geyer
                            105                                       10329                             Geyer
                            106                                       10330                             Geyer
                            107                                                                         Geyer
                            108                                                                         Geyer and Elvers
                            109                                                                         Elvers,
                            110                                                                         Elvers
                            119                                                                         Sidner
                            120                                       12632                             Sidner
                            121                                       10331                             Sidner
                            126                                       11453                             Parker
                            127                                       11454                             Parker
                            128                                       11455                             Parker
                            133                                                                         West Flower Garden
                            134                                       13366                             West Flower Garden
                            135                                                                         West Flower Garden
                            136                                                                         West Flower Garden
                            138                                                                         East Flower Garden
                            139                                                                         East Flower Gar-den
                            140                                                                         East Flower Gar-den
                            141                                        9210                             Rankin
                            142                                        8217                             Rankin
                            144                                       11456                             Bright
                            145                                       11457                             Bright
                            146                                                                         Bright
                            148                                                                         Geyer
                            149                                                                         Geyer
                            150                                                                         Geyer
                            151                                       11459                             Geyer
                            152                                       10333                             Geyer and Elvers
                            153                                                                         Elvers,
                            154                                        9212                             Elvers,
                            155                                                                         Elvers,
                            177                                                                         West Flower Garden
                            178                                                                         West Flower Garden
                            179                                       11464                             West Flower Garden
                            180                                                                         West Flower Garden
                            192                                        3301                             Geyer











                                                                                                                   A-13


                                                     Garden Banks (continued)

                      Block                        OCS-G No. (if leased)                Bank

                      193                                   4130                        Geyer
                      194                                                               Geyer
                      195                                 10336                         Geyer
                      196                                 11468                         Geyer and Elvers
                      197                                                               Elvers
                      198                                 10338                         Elvers
                      237                                   2812                        Geyer
                      238                                                               Geyer
                      239                                 11475                         Geyer













                                                                       Appendix B



                                                                Biological Opinions




















                                                                  APPENDIX B


                                                           BIOLOGICAL OPINIONS

                     In compliance with Section 7(a)(2) of the Endangered Species Act of 1973 (16 U.S.C. 1531-1543), as amended,
                MMS initiated endangered species consultation with the U.S. Fish and Wildlife Service (FWS) and the National
                Marine Fisheries Service (NMFS) for proposed Gulf of Mexico Oil and Gas Lease Sales 142 and 143. A copy of
                this Draft EIS has been officially transmitted to the appropriate FWS and NMFS offices as an attachment to the
                letters requesting initiation of consultation. This Draft EIS will be used as the primary information base for the
                consultations. The MMS, Gulf of Mexico Regional Office continually consults and coordinates with the
                appropriate FWS and NMFS field offices regarding endangered species that may be affected by oil and gas
                operations. There have been no known significant changes to the endangered species situation in the Gulf; thus,
                the Biological Opinions resulting from this consultation are not expected to change significantly from the most
                recent Opinions for Sales 139 and 141, which were published in the Final EIS for those sales (USDO1, MMS,
                1991a). These Opinions are republished here for information purposes. The Biological Opinions for proposed
                Sales 142 and 143 will be published in the Final EIS for these sales, along with any changes to the EIS that may
                result from the consultations.
                    For more information, see Section I.B.4.c. and the appropriate parts of Sections III.B. and I'V.D.















I                   National Marine Fisheries Service

                           Biological Opinion

                             Gulf of Mexico

                            Sales 139 and 141











                                                             WI"IKO STATUO OKP^P"42@" OP 00100CU                   MKS hassuals cooperated With NMFS in conducting exploratory
                                                             PAnuorAW Ck@    Aw-*P@                                    i
                                                                                                                    aer al   rvoys of deep water areas in the north-central GON.
                                                                                                                    Areas studied included underwater canyons, a cliff and a seamount
                                                                     -0 @o                                          with depths ranging from 200-1800m. Over 2900 dolphins and
                                                            -6 CW*CTOR                                              whales were counted in 113 siqhtings. The endangered spars whale
                                                                                                                    W a the most commonly sighted species. NMFS conducted a pilot
                                                                             FEB 0 8 1991                           vessel survey in 1990 to evaluate the feasibility of using vessel
                                                                                                                    surveys to determine marine mammal abundance and trends in the
                       Mr. James W. Workman                                                                         d                  a GON. Sighting rates from the research
                                                                                                                    v:eper waters of th
                       Deputy Associate Director                                                                       mal were comparable to those observed in research cruises in
                         for Offshore Leasing                                                                       Pa:ific waters, indicating that vessel surveys are a viable means
                       U S. Department of Interior                                                                  of assessing cotacean populatioas in deep waters of the GON.
                       Minerals Management Service                                                                  NMFS intends to continue vessel surveys on a regular basis to
                       Washington, D.C. 20240                                                                       further assess deepwater catacean and turtle populations.
                       Dear Mr. Workman:                                                                            Both of these efforts suggest that cetaceans may be relatively
                                                                                                                    ab ndant in deeper offshore waters of the GON. If these
                       This is in response to Minerals Management Service's (MS)                                    prueliminary finding: prove correct, the potential impacts of oil
                       request for an Endangered Species Act (ESA) Section 7                                        and gas activities o cotaceans   wi 11 be of increasing concern as
                       Consultation on proposed Gulf of Mexico (GOM) oil and gas      lease                         the industry expands further offshore. Additional information on
                       sale 139 in the central GON, and an unnumbered western GON                                   these populations will be needed, at some point, to satisfy
                       offering. Lease sale 139 is comprised of blocks in the central                               Section 7 information requirements.
                       GOM planning area, and the unnumbered offering encompasses blocks
                       in the western GON planning area. These areas constitute                                     Because no "new" information that might alter our previous
                       approximately 84 million acres offshore Texas, Louisiana,                                    opinion has become available, and because the areas and species
                       Mississippi, and Alabama. Documents provided with your letter                                impacted by the proposed activity remain unchanged   ,
                       indicate that the proposed action may                                                                                                               the
                                                               adversely affect sea                                 conclusions of our November 2, 1987, opinion are valid and are
                       turtles.                                                                                     applicable to proposed lease sale 139 and the unnumbered lease
                       The proposed lease sales are a reoffering of unleased blocks in                              sale in the western GOM.
                       the central and western GON. The National Marine Fisheries                                   This concludes consultation responsibilities under Section 7 of
                       service (NMFS) consulted with MMS on oil and gas lease sales                                 the ESA. However, consultation should be rainitiated if new
                       113/115/116, and issued a Biological Opinion on November 2, 1987                             information reveal* impacts of ;he identified activity that may
                       (enclosed). This opinion considered all phases of exploration,                               affect listed species or their critical habitat, a new species is
                       development, and production activities that have occurred or are                                              t
                       proposed in the GON.                                                                         listed, the iden ified activity is subsequently modified or
                                              In the November 2, 1987, opinion, NMFS                                critical habitat determined that may be affected by the proposed
                       concluded that those activities were not likely to jeopardize the                            activity.
                       continued existence of any endangered and threatened species
                       under our Jurisdiction. Opinions issued for lease sales 123 and                              I look forward to your continued cooperation in future
                       125 on May 22, 1989, and lease sales 131/135/137 on                                          consultations, and in developing the needed information.
                       April 9, 1990, (enclosed) were also for reofferings of lease
                       sales 113/115/116.                                                                                                                Sincerely,

                       since issuance of our November 2, 1987, opinion, MMS and NMFS
                       have conducted cooperative research activities to better assess
                       potential interactions between sea turtles and listed cetaceans                                                                   414  60 .
                       and oil and gas activities. Data collected thus far have                                                                          William W. Fox, Jr.
                       provided important information regarding the frequency and
                       location Of sea turtle and marine mammal/platform associations.                              Enclosures
                       MKS recently funded additional cooperative research to conduct
                       radio, sonic and satellite turtle tracking experiments in the
                       vicinity of the Chandelour islands, Louisiana, where turtle
                       occurrence was found to be correlated with presence of
                       structures. This study should provide important information on
                       turtle habitat utilization and movements within an area of high
                       platform concentrations.

                                                                -E ASM- AOMNG@TCR
                                                                         @RES






                                                                                                                                                                                                     tZ




















                                                                  TUN@ AffiVQ PVS@-CRES SERVICE
                                                               S,- So-g- M--V4-o aceia                                      injured or killed during any phase    of the proposed activity, the
                                                                                                                            incident must be reported to NOAA Fisheries Southeast Regional
                                                                                                                            Director an soon  *0 possible. HOAA Fisheries will cooperate with
                                                                                                                            MKS in a review of the incident to determine the need for
                         Mr. Barry Williamson                                                                               developing appropriate mitigation measures.
                         Director                                                                                           This concludes consultation responsibilities under Section 7 of
                         Minerals Management Service                                                                        the ESA. However, consultation should be rainitiated if new
                         U.S. Department of Interior                                                                        information reveals impacts of the identified activity that way
                         Washington, D.C. 20240                                                                             affect listed species or their critical habitat, a new species is
                                                                                                                            listed, the identified activity is subsequently modified or
                         Dear Mr. Williamson:                                                                               critical habitat determined that may be affected by the proposed
                         This responds to Minerals Management Service's (MMS) request for                                   activity.
                         an Endangered species Act Section 7 consultation on proposed Gulf                                  NOAA Fisheries is looking forward to participating in MKS'
                         of Mexico (GMX) oil and ga! Lease S4,i:!il            --   scheduled.                              Protected Species Workshop scheduled for August 1-3, 1989, in Now
                                                               p      !?Y!nd 125            3
                         for March 1990 and August 990, res                  Lease Sale 12 is                               Orleans, Louisiana, which should prove useful in identifying and
                         comprised of blocks in the central GMX planning area, and Sale                                     prioritizing research projects that have direct application to
                         125 encompasses blocks in the western GMX planning area.                                           our Section 7 information needs.
                         Excerpts from the Draft Environmental Impact Statement provided
                         with your letter indicate that the proposed action may adversely                                   1 look forward to your continued cooperation in future
                         affect sea turtles.                                                                                consultation*, and in developing needed information.
                         The National Marine Fisheries Service (NOAA Fisheries) has                                                                          Sincerely,
                         reviewed the information provided with your letter and concludes
                         that the proposed lease sales are a reoffering of unleased blocks
                         addressed in our November 2, 1987, Biological opinion on oil and
                         gas Lease Sales 113/115/116. Thq 1987 opinion considered all
                         phases of exploration, development, and production activities                                                                       James W. Brennan
                         that have occurred or are proposed in the GMX. In the                                                                               Assistant Administrator
                         November 2 opinion, NOAA Fisheries concluded that these                                                                               for Fisheries
                         activities were not likely to jeopardize the continued existence
                         of any endangered or threatened species under our jurisdiction.

                         Since there is no new information that might alter our previous
                         opinion, and because the areas and species impacted by the
                         proposed activity remain unchanged, the conclusions of the
                         November 2, 1987, opinion are valid and are applicable to
                         proposed Laase Sales 123 and 125.

                         No records of sea turtle take in the course of oil and gas
                         exploration activities have boon reported. However, there is a
                         growing body of evidence that oil and gas related activities
                         (i.e.. exposure to oil spills, vessel collisions, disorientation
                         by vessel/platform lights, etc.) may adversely affect sea
                         turtles. These potential impacts were discussed in the
                         November 2, 1987, opinion. NOAA Fisheries does not
                         anticipate any sea turtle take as a result of leasing and
                         exploration activities associated with Iease Sales 123 and 125.
                         However, as a condition of this statement, if a sea turtle is





                         cc: F/CU(2), F/PR2(2), GCF
                         F/PR2:RZiobro:427-2322:5/11/89:dat      (f)    (123-1.25Z.MKS)



















                                                            UNITSO STATES OC.^p,-KNT Op CCM@gcs                     and
                                                                                                                    b ito develop & prioritized list of research objectives.       NMFS
                                                                    V-NC PS@E,@ES SE.@CE                            el eve* that the workshop results adequately reflect information
                                                                                                                    needs for future Section 7 Lease Sale Consultations in the Gulf
                                                            s@
                                                                                                                    of Mexico, and we hop* that KMS will continue to support studies
                                                                                                                    directed toward providing this information.
                                                      APR 7    113cl
                                                                                                                    B cause no "now" information that might altar our previous
                      Mr. Barry Williamson                                                                          o:inion has become available, and because the areas and species
                      Director                                                                                      impacted by the proposed activity remain unchanged, the
                      U.S. Department of Interior                                                                   conclusions of our November 2, 1987, opinion are valid and are
                      Minerals Management Service                                                                   applicable to proposed Lease Sales 131, 135, and 137.
                      Washington, D.C. 20235
                                                                                                                    This concludes consultation responsibilities under Section 7 of
                      Dear Mr. Williamson:                                                                          the Endangered Species Act. However, consultation should be
                                                                                                                    rainitiated if now information reveals impacts of the identified
                      This responds to Minerals Management Servic:tl (MMS) request for                              activity that may affect listed species or their critical
                      an Endangered Species Act Section 7 Consult      on an proposed Gulf                          habitat, a now species is listed, the   identified activity is
                      Of Mexico (GON) oil and gas Lease Sales 131, 135, and 137.        Lease                       subsequently modified or critical habitat determined that    may be
                      Sale 131 is comprised of blocks in the central GOM planning area,                             affected by the proposed activity.
                      Lease Sale 135 encompasses blocks in the western GOM planning
                      area, and Lease Sale 137 includes blocks in the eastern GOM                                   I look forward to your continued cooperation in future
                      planning area.   Documents provided with your letter indicate that                            Consultations and in developing the needed information.
                      the proposed action may adversely affect sea turtles.
                      The National Marine Fisheries Service (NMFS) has reviewed the                                                                Sincerely,
                      information provided and concludes that the proposed lease sales
                      are a reoffering of unleased blocks addressed in our November 2,
                      1987, Biological opinion on oil and gas Lease Sales 113/115/116
                      (enclosed) . The 1987 opinion considered all phases of                                                                       William W. FOR, Jr.
                      exploration, development, and production activities that have                                                                Assistant Administrator
                      occurred or are proposed in the GON.    In the  November 2 opinion,                                                            for Fisheries
                      NMFS concluded that these activities were not likely to
                      jeopardize the continued existence of any endangered and                                      Enclosure
                      threatened species under our jurisdiction.
                      Since issuance of our November 2, 1987, opinion, KMS and 'NMFS
                      have conducted cooperative research activities to better assess
                      potential interactions between sea turtles and listed cetaceans
                      and oil and gas activities. Data collected thus far have
                      provided important information regarding the frequency and
                      location of turtle and marine mammal/Platform associations.
                      While the data remain inconclusive, turtle occurrence was found
                      to be correlated with presence of structures in one of five areas
                      studied, while correlations were not Observed in the remaining
                      four study areas. These preliminary data suggest that it may be
                      possible to identify areas and times of potential "high risk-- to
                      listed species, while potent  ial risks to endangered and
                      threatened species may be minimal in other areas and times.                                   cc:  F/CU(2), GCF    Gleaves, F/SER23    T. Henwood,
                      in addition to the cooperative research efforts described above,                                   F/PR2 - Ziobro, F/PR2 - Holman
                      MMS recently sponsored a workshop on sea turtles and marine
                      mammals. The purpose of the workshop was to identify information
                      gaps in our knowledge of listed species in the Gulf of Mexico,



                                                                                           M'.


                                                                                                                                                                                                      tZ













                                                                                                                                                                                                       tZ
                                                                                                                                                                                                       60



                                                                                       FCOMMEAC9                    with various types of explosives or removal techniques.
                                                                                                                    Therefore, we believe that consultations on all platform removals
                                                                                                                    using explosive means should be continued on a case-by-case basis
                                                 S/                                                                 until additional data are available to allow a more complete
                                                           NOV 2                                                    assessment of the effects of such actions on listed species.
                                                                                                                    I look forward to your continued cooperation in future
                                                                                                                    consultations.
                      Mr. William D. Bettenberg
                      Director                                                                                                                       Sincerely,
                      Minerals management Service
                      U.S. Department of the Interior
                      Washington, D.C. 20240

                      Dear Mr. Bettenberg:
                      This responds to your January 12, 1987# request for an Endangered                                                              @Xiliam E. Evans
                                                                                                                                                     ,Assistant Administrator
                      Species Act Section 7 Consultation on proposed oil and-Q    Is ' :a@e                                                            for Fisheries
                      sales 113/115/116 in the Gulf of Mexico Outer Continental Sh     lf
                      (OCS) Oil and Gas       n
                                        _I&AL" planning area.      These sales are                                  Enclosure
                      tentatively scheduleU T5-r March, August and November, 1988. The
                      Draft Environmental Impact Statement received in May 1987
                      indicates that the proposed action may adversely affect sea
                      turtles.

                      Enclosed is the Biological Opinion prepared by the National Marine
                      Fisheries Service (NMFS) concerning the proposed activities. At
                      the request of MMS, this opinion addresses all phases of OCS
                      exploration, development, and production activities that have
                      occurred or are proposed in the GOM. NMFS concludes that these
                      actions are not likely to jeopardize the continued existence of
                      any endangered or threatened species under our jurisdiction.       In
                      formulating this opinion NMFS used the best available information,
                      including scientific and commercial data and past records of oil
                      and gas lease sales.

                      Rhile NMFS has concluded that the proposed activities are not
                      likely to jeopardize endangered and threatened species, -e believe
                      that at some point the additive effects of oil and gas activities
                      and all other activities in the GOM may constitute a jeopardy
                      s i tuat ion. To determine when this point may be reached,
                      additional research is needed to quantify all sources of mortality
                      and to determine existing population levels.

                      With regard to the issue of rig removals using explosives, NMFS
                      had hoped that sufficient data would,be available to enable us to
                      render an opinion on the effects of Gulfwide abandonment
                      activities on endangered and threatened marine species. However,
                      few removals have occurred and we still have little data from
                      which to draw conclusions about the potential impacts associated



                                                                                         i. WIW F)















                               Endangered Species Act - Section 7 Consultation                                      In the biological opinion on proposed OCS Lease Sales 110 and 112,
                                                                                                                    NMFS only addressed the leasing and exploration phases. The
                                             BIOLOGICAL OPINION                                                     development* production, and abandonment phases were not
                                                                                                                    considered. In a letter of September 9, 1986, MMS stated their
                        Agency: Minerals management Service (MKS), U.S. Department                                  intent to request formal consultation on the effects of all ocs
                               of interior (DOI).                                                                   development, production, and abandonment activities that have
                                                                                                                    occurred and are proposed in the GOM. MMS initiated formal
                        Activitys outer Continental Shelf (OCS) Oil and Gas Lease                                   consultation for these components of OCS-related activities on
                                  Sales in the Eastern, central and Western Gulf of                                 January 12, 1987 in conjunction with upcoming Lease Sales
                                  Mexico (GOM).                                                                     113/115/116. However, in view of the scant information available
                                                                                                                    on which to base an assessment of impacts of all abandonment
                        Consultation Conducted By: National Marine Fisheries                                        activities on endangered and threatened species in the GOM, NMFS
                                                    Service, Southeast Regional                                     determined that consultations for future abandonment activities
                                                    Office                                                          should continue to be conducted on a case-by-case basis until
                                                                                                                    :ufficient datoacare av:ilabll,tooallow a more complete assessment
                        Date issued:   yfly -                                                                        f impacts ass iated ith p tf rm removal using explosives.
                                                                                                                    This biological opinion responds to the MMS January 12, 1987,
                        Backgrounds                                                                                 letter. It is based on the best scientific and commercial data
                        In accordance with Section 7(a) of the Endangered Species Act, MMS                          available and incorporates information from: (1) the 1979 NMFS
                        in a letter dated January 12, 1987, requested formal consultation                           biological opinion; (2) the DEIS prepared by MMS for the proposed
                        on proposed Oil and Gas Lease Sales 113/115/116 in Federal waters                           oil and gas Lease Sales; (3) the scientific literature; and (4)
                        of the Eastern, Central and Western Gulf of Mexico (GOM) OCS Oil                            other pertinent and available information.    The conclusions
                        and Gas Leasing planning Areas.   This consultation was to consider                         offered in this opinion are based on current information on the
                        the effects Of leasing and exploration associated with these sales                          distributions and abundance of threatened and endangered species,
                        as well as all OCS oil and g::V:evelopment, production and                                  probable effects of all OCS oil and gas development, prodaction
                        abandonment activities that       occurred and are proposed in the                          and abandonment scenarios, and potential effect to listed
                        GON through the year 2023.                                                                  species.
                        On March 29, 1979, the National Marine Fisheries service (NMFS)                             Proposed Activity
                        issued a biological opinion for a regionwide consultation on the                            This consultation addresses the potential effects of OCS oil and
                        OCS oil and gas leasing program in the Gulf of Mexico.    This                              gas exploration, production and development activities associated
                        opinion addressed, in general terms, the effects of the MMS GOM                             with past, present and proposed future lease offerings through
                        leasing programs on endangered and threatened species under the                             2023 in the Eastern, Central and Western Gulf of Mexico with the
                        jurisdiction of the NNFS.   Several consultations on specific OCS                           exception of administratively deferred areas as identified in the
                        lease sale* in the GON have been conducted since the March 1979
                        opinion. Those Consultations resulted in the determination that                             DEIS (MMS 1987).
                        the lease sales did not substantively modify the earlier lease                              Central Gulf of Mexico Lease Sale 113
                        sale proposals covered by the NMFS regionwide biological
                        opinion.  At the time Of these previous consultations,    nonclusions                       The proposed action will offer for lease all unleased acreage in
                        significant now information was available to alter the co   ies been                        the Central Planning Area (CPA) which amounts to approximately
                        reached in the NKFS 1979 opinion, nor had additional SPOC                                   34.5 million acres or 6,341 blocks. This area is located from 3
                        listed am endangered or threatened, or critical habitat                                     to 220 miles offshore in water depths ranging from 4 m to 3,200 m.
                        designated. that would be affected by the proposed actions.                                 MMS has provided a mean-case scenario resource estimate of 0.220
                        On December 30, 1995, KHS sought from NMFS concurrence on its                               billion barrels of oil and 1.840 tcf of gas during the period of
                        determination that reinitiation of formal Section 7 consultation                            1990-2011.  MMS estimates that the sale will result in the
                        was not needed for OCS Lease Sale 110 and 112 in the GOM.      The                          drilling of 281 exploration and delineation wells# installation of
                        NMFS responded in a March 10, 1986, letter that nev information                             30 production platforms, drilling of 345 development wells and the
                        relative to the potential impacts ofsoil on sea turtles may be                              emplacement of 150 miles of pipeline. Based on this development
                        available.  in a July 24, 1 986, Is tt r the MKS reinitiated formal                         scenario, MKS estimates the probability of one or more large oil
                        consultation for OCS Lease Sales 110 and 112 on the basis of the                            spills (more than 1,000 bbIs) to be 41%, medium spills (50-999
                        availability Of now information and the need to update and revise                           bbls) to be 95%, and small spills (1-49 bbls) to be 99+&.
                        the earlier 1979 biological opinion.


                                                                                                                                                    2









                                                                                                                                                                                                            tz



                          MMS also provided a cumulative mean-case scenario resource                                       MMS has provided a mean-case scenario resource estimate of 0.030
                          estimate for the Central GON of 3.02 billion bble of oil and 24.16                               billion barrels of oil and 0.180 tcf of gas during the period of
                          tcf of gas to be developed during the period of 1988-2023.       MMS                             1990-2011. MMS estimates that the sale will result in the
                          estimates that subsequent to the proposed sale, 2,560 exploration                                drilling of 10 exploration and delineation wellsi installation of
                          and delineation wells will be drilledp 330 production platforms                                  2 production platformso drilling of 19 development wells and the
                          constructed, 4,430 development wells will be drilled and 2,400                                   emplacement of 35 miles of pipeline. Based on this development
                          miles of pipelines emplaced.    These will be in addition to the                                 scenario, MMS estimates the probability of one or more large oil
                          existinq offshore infrastructure of 3,6SS platforms and 15,000                                   spill (more than 1,000 bbla) to be 61, medium spills (50-999 b1bls)
                          miles of pipelines.    Estimates of the probability of large, medium                             to be 341, and small spills (1-49 bbls) to be 99+1.
                          and small oil spills all exceed 99+%.
                                                                                                                           MMS also provided a cumulative mean-case scenario resource
                          western Gulf of Mexico Lease Sale 115                                                            estimate for the Eastern GOM of 0.42 billion bbls of oil and 2.06
                                                                                                                           tcf of gas to be developed during the period of 1988-2023.    MmS
                          The proposed action for Sale 115 will    offer for lease all unleased                            estimates that subsequent to the proposed sale, 300 exploration
                          acreage in the Western Planning Area with the exception of                                       and delineation wells will be drilled* 24 production platforms
                          administratively deferred areas.    Areas available for leasing are                              constructed, 340 development wells will be drilled and 540 miles
                          approximately 29.0 million acres or 5,244 blocks located from 9-                                 of pipelines emplaced. No offshore infrastructure presently
                          222 miles offshore in water depths ranging from 8m to over                                       xists. Estimates of the probability of large, medium and small
                                                                                           Flower                          oil spills all exceed 99+%.
                          3,000m. Excluded from the offering are Blocks A-375 (East                                        e
                          Garden Bank) and A-398 (West Flower Garden Bank) in the High
                          Island area.
                          11MS has provided a mean-case scenario resource estimate of 0.110                                Listed Species and Critical Habitat
                          billion barrels of oil and 1.610 tcf of gas during the period of                                 Listed species under the jurisdiction of the NMFS that may occur
                          1990-2011. MMS estimates that the sale will result in the.                                       in the project area include:
                          drilling of 187 exploration and delineation wells, installation of
                          20 production platforms, drilling of 230 development wells and the                               Listed Species Scientific Name        Status   Date Listed
                          emplacement of 120 miles of pipeline. Based on this development
                          scenario, MMS estimates the probability of one or more larqe oil                                 Sperm whale   ;hfs            n          E      12/2/70
                          spills (more than 1,000 bbls) to be 22%, medium spills (50-999                                   Fin whale                     ysalus     E      12/2/70
                          bbls) to be 791, and small spills (1-49 bbls) to be 99+t.                                        Humpback -hale negapter novaeangliae     E      12/2/70
                                                                                                                           Sei whale     3alaenopteca boreali,      E      12/2/70
                          The cumulative mean-case scenario resource estimate for the                                      Right whale   Eubaleana giaciaLIS        E;     12/2/70
                          Western GOM is 1.75 billion bbls of oil and 24.33 tcf of gas to be                               Blue whale    Salaenoptera musculus      E      12/2/70
                          developed during the period of 1988-2023. MMS estimates that
                          subsequent to the proposed sale, 1,780 exploration and delineation                               Kemp's ridley Levidochelys kempi         E      12/2/70
                          wells will be drilled, 220 production platforms constructed, 3,400                               Green         Chelonia mydas             T E*   7/28/78
                          development wells will be drilled and 1,780 miles of pipelines                                   Hawksbill     E-re-t-m-oc-h-el-y-s-TimbricataE    6/2/70
                          emplaced.   These will be in addition to the existing offshore                                   Leatherback   Dermochelys coci-ac-ea'    E        6/2/70
                          infrastructure of 365 platforms and 2,000 miles of pipelines.                                                                                    7/28/78
                          Estimates of the probability of large, medium or small oil spills                                Loggerhead    Caretta caretta            T
                          all exceed 99+1.                                                                                 -All of the U.S. green turtle populations are listed as
                                                                                                                           threatened, except for the Florida breeding population which is
                          Eastern Gulf of Mexico Lease Sale 116                                                            listed as endangered.
                          .The proposed action for Sale 116 will   offer for lease all unleased                            No critical habitat has been identified by NMFS for the above
                          acreage in the Eastern Planning Area with the exception of                                       species within the project area.
                          administratively deferred areas. Areas available for leasing are
                          approximately 71.8 million acres or 12,744 Blocks located from 10-                               Marine Mammals
                          300 miles offshore in water depths ranging from 10 m to over
                          3,400m. Excluded from the offering are 23 blocks in the Florida                                  Sperm Whale
                          middle Ground area, 186 blocks containing seagrass beds, and 251
                          blocks in the Oestin Dome Official Protraction Diagram area.                                     Little information on the distribution and abundance of endangered


                                                                                                                                                      4














                           whales in the Gulf of Mexico is available, but it is believed that                                    not known to frequent the GOMr although there are have been
                           the sperm whale is the most numerous of the listed whales.                    Berzin                  occasional sightings off south Florida (Schmidly 1981).
                           (1971) reports sperm whales are restricted to waters deeper than
                           300m, while Watkins (1977) states that their primary distribution                                     Sea Turtles
                           is in waters deeper than 1,000 m.        Of 61 sperm whales sighted in
                           the GON/South Atlantic regions during aerial surveys conducted in                                     Loggerhead turtle (Caretta caretta)
                           1980 and 1981 (Fritts at al. 1983), water depths ranged from 104
                           to 2v742m.    This species is often found near the continental shelf
                           break or in association withi:reas of upwelling (Gosho at al.                                         The threatened loggerhead turtle is the most abundant species
                           1984).   Sperm whales feed pr arily on deep water cephalopods                                         occurring in GOM waters.      Loggerheads inhabit coastal areas of the
                           (squid) which aggregate in large numbers near areas of cold and                                       continental shelf where they foraqe around rocky places, coral
                           warm water convergence such as bottom drop-off areas (Marcuzzi and                                    reefs, shellfish beds and old boat wrecks; they commonly enter
                           Pilleri 1971).    The current estimated population of sperm whales                                    bays, lagoons and estuaries (Ernst and Barbour 1972).            Aerial
                           in the North Atlantic is 99     '500 (Braham 1984); no estimates of the                               surveys of loggerhead turtles at sea indicate that they are most
                           sperm whale population size in the GUM are available.                                                 common in waters less than 50 m in depth (Shoop at al. 1981;
                                                                                                                                 Fritts at al. 1983)p but they occur pelagically as well.            The
                           The best available information on sperm whales in the           Gulf of                               ?rimary food sources of the loggerhead turtle are benthic
                           Mexico is provided by Fritz at al. (1983).         The major    findings of                           invertebrates including molluscs, crustaceans and sponges
                           their survey included: (1) more sperm whale sightings           occurred                              (Mortimer 1982).    Crabs and conchs were identified (Carr 1952) as
                           beyond the continental shelf off the Texas coast than           in the other                          the most frequently found items in stomachs, although loggerheads
                           survey areas (LA, West FL and East FL), (2) the average depth of                                      often eat fish, clams, oysters, sponges and jellyfish.           Ernst and
                           sightings in the GOM was lol67m (N-19). (3) sperm whales were                                         Barbour (1972) included marine grasses and seaweeds, mussels,
                           associated with oceanographic features such as the Loop Current,                                      borers, squid, shrimp, amphipods, crabs, barnacles and sea urchins
                           Gulf Stream and other currents, and (4) calves made up 20% of all                                     among the foods of loggerhead turtles.
                           whales observed.     Mixed group sizes ranqed from 2 to 14
                           individuals.                                                                                          In the GOM, loggerhead turtles commonly occur throughout -the inner
                           Other Listed Marine mammals                                                                           continental shelf.     Populations of loggerheads have been under
                                                                                                                                 str ss for a number of years due, among other things, to
                           Data on the other listed whales which                                                                 mortalities caused by the incidental drowning in shrimp trawls.
                                                                       potentially occur in the GOM                              An eietimated 3 ,129 individuals are killed annually by shrimp
                           is limited.    Fritz at al. (1983) did not sight fin, sei, humpback,                                  t raw rs in the GOM (Henwood and Stuntz 1986).
                           right or blue whales in their Gulf of Mexico surveys.           Right
                           whales (Eubaleana glacialis) are not common in the GOM, but                                           The green turtle (Chelonia mydas)
                           Schmidly (L981) rerrtga.the sighting of two right whales near
                           Sarasota, Florida     n 1   3 and one stranding near Freeport, Texas                                  Green turtles are circumglobally distributed mainly in waters
                           in 1972.   In the western North Atlantic, right whales primarily                                      between the northern and southern 200 C isotherms (Hirth 1971). In
                           range in the waters off east Florida to Iceland.          Most recent                                 the western Atlantic, several major nesting assemblages have been
                           population estimates for right whales in the western North                                            identified and studied (Peters 1954; Carr and Ogren 1960; Duellman
                           Atlantic are between 200 and 400 individuals (Xraus at al. 1986)              .                       1961; Parsons 1962; Pritchard 1969a; Schulz 1975; Carr and Carr
                                                                                                                                 1978 ). How  ve%ci  n   he    ntinental U.S., the only known green
                           Blue whale       1                                                                                       t                              t
                                     t: (%a :On-Vt rga,muculus) are primarily coldwather                                         tur 1. nestling    Cure oncthe A lantic coast of Florida (Ehrhart
                           inhabitan      n   r. tF,:.   t to avoid warmer waters (Mi      .roc et al.                           1979). The major portion of the qreen turtle's life is spent on
                           1984).   There are two questionable records of the occurrence of                                      the foraging grounds.     Some of the principal feeding pastures in
                           this species in the GOR (Schmidly 1981). One stranding was
                                                                     Texas and the other near the                                northwestern coast of Yucatan peninsula, south coast of Cuba,
                           reported in 1940 in Braxoria County,                                                                  the western Atlantic Ocean include: upper west coast of Florida,
                           mouth of Sabine Pass, Louisiana in 1924. Records of sei whale                                         Mosquito Coast of Nicaragua, Caribbean coast of Panama, scattered
                           (Balaenoptera borealis) occurrence in the GUM are limited to two                                      areas along Colombia# and Scattered areas off the Brazilian coast
                           strandings from the coasts of Mississippi and Louisiana and one                                       (Hirth 1971). The preferred food sources in these areas are:
                           from Campech*v Mexico (Schmidly 1981).        Fin whales (Balaenoptera                                Cymodoceap Thalassia, Zostera, in Sagittaria and Vallisneria
                           physalus),are thought to be more abundant 1:,th:xGOM          wher                                    (Bab ock 1937; Underwood 1951; Carr 1954; Carr 1952; Neill 1958;
                           stranding have been documented in Louisian           T    a and Florida.                              Mexico 1966).
                           Based on the apparent presence of fin whales in the northern GOM
                           throughout the year* Schmidly ( 1981) speculates that there may be                                    In the GON, the only major feeding pasture where juvenile and
                           an isolated stock.     Humpback whales (Megaptera novaeanoliae) are                                   subadult green turtles (carapace lenqth less than 81 cm) are known


                                                                5                                                                                                  6












                                                                                                                                                                                                                 tZ



                           tosoccur is the upper west coast of Florida.       Green turtles                                pollution, etc.    An estimated 501 individuals are killed annually
                           hi torically flourished in the inshore bays of Texas, but these                                 by shrimp trawlers in the GON (Henwood and Stuntz 1987).
                           populations were exploited by a fishery in the late 1800's
                           (Hildebrand 1980; 19821  Dough ty  1984).   Green turtles occurring      in                     Rawksbill turtle (Eretmochelys imbricate)
                           other areas of the GON may be in the omnivorous stage of their
                           life cycles prior to the age of recruitment to feeding pastures.
                           Older green turtles are unlikely to permanently reside in most                                  The hawksbill turtle is relatively uncommon in the waters of the
                           areas of the GOM because of the scarcity of suitable sea grass                                  continental U.S.    The preferred habitat of this species is coral
                           pastures.                                                                                       reef, such as is found in the Caribbean and Central America.
                                                                                                                           However, there are accounts of hawksbill3 in South Florida and a
                           The Kemp's ridley turtle (LePidochelys kempi)                                                   surprising number are encountered in Texas.        Most of the Texas
                                                                                                                           records are small turtles, probably in the 1-2 year class range.
                           Of the seven extant species of sea turtles of      the world, the                               Many of these captures or strandings are of individuals in an
                           Kemp's ridley is probably in the greatest danger of extinction.                                 unhealthy or injured condition (Hildebrand 1980; 1982).         The lack
                           The only major nesting area for this species is a single stretch                                of sponge-covered reefs and the cold winters in the northern GOM,
                           of beach near Rancho Nuevo, Tamaulipas, Mexico (Carr 1963;                                      probably prevent hawksbills from establishing a viable population
                           Hildebrand 1963).   Virtually the entire world population of adult                              size in this area.
                           females nest annually in this single locality      (Pritcharo 1969b).
                                                                                                                           Leatherback turtle (Dermochelys coriacea)
                           When nesting aggregations at Rancho Nuevo were discovered in 1947,
                           adult female populations were estimated to be      in excess of 40,000                          The leatherback turtle is found throughout the waters of the
                           individuals (Hildebrand 1963).     By the early 1970's, the world                               Atlantic, Pacific, Caribbean and the Gulf of Mexico (Ernst and
                           population estimate of mature temale Kemp's ridleys had been                                    Barbour 1972).    It is the most pelagically distributed of the sea
                           reduced to 2500-5000 individuals.     Most recent estimates of the                              turtles feeding primarily off jellyfish (Rebel 1974).
                           total population of sexually mature female Kemp's ridleys. aire less                            Leatherbacks are occasionally taken by shrimp trawlers and
                           than 260 turtles (Byles pers comm 1987).                                                        longline vessels in GOM offshore waters# but these records are
                                                                                                                           scarce and Hildebrand (1982) speculates that the resultant
                           The foraging range of mature Kemp's ridley turtles is restricted                                mortality is small.
                           to the Gulf of Mexico.    Evidence provided by tagging programs
                           (Chavez 1968), suggests that post-nestinq females move in                                       Assessment of Impactst
                           comparable numhers to the north (mostly to Louisiana) and to the
                           south (mostly to Campeche) (Pritchard and Marquez 1973).                                        Cetaceans
                           movements of hatchling Kemp's ridleys may be controlled by current
                           patterns: either the Loop Current for northward transport or an                                 The effects of oil and gas activities on whales in the Gulf of
                           eddy for southward transport with occasional transportation                                     Mexico have never been studied, but the DEIS (MMS 1987) concludes
                           through the Florida Straits via the Gulf Stream       (Hildebrand                               that the proposed activity will have a very low level of impact to
                           1982).  If distribution is controlled by currents, approximately                                whales.   This determination appears justified considering the
                           half of the annual hatchling production from Rancho Nuevo will                                  scarcity  of whales in the GOM and their preference for deeper
                           recruit to the nearshore waters of the central GOM.                                             waters.   The following are some concerns regarding the potential
                           Kemp's ridley turtles feed primarily in shallow coastal waters           on                     impacts of GON oil and gas activities to whale populations:
                           bottom-lLving crustaceans (Hildebrand 1982).       Organisms identified                         (1)   Increased ship traffic associated with OCS-related activities
                           from stomachs include crabs (Palyonchus, Hepatus, Callinectes,                                        increases the potential for collisions with whales.         Fritz et
                           Panopeus, Menippe, Ovalipes, Calappa, Portunus, Arenaeus), fish                                       al. (1903) noted that this source of Injury/mortality could
                           (Lutjanust Leiostomus) and molluscs (Noculana, Corbula, Mulinia,                                      increase the danger to sperm whale populations in the GOM.
                           Nassarius) (Dobie at al. 1961; Pritchard and Marquez 1973).              All                          Numerous accounts of accidental collisions between sperm
                           of these genera are forms common in the Gulf of Mexico and the                                        whales and a variety of boat/vessel classes have been
                           eastern coast of the United States.                                                                   documented (Berzin 1971; Gaskin 1964; Slijper 1979; Caldwell
                                                                                                                                 et al. 1966), but the potential impact of OCS-related vessel
                           In the Gulf of Mexico, the number of stranded Kemp's ridleys has                                      collisions to sperm whales and other marine mammals in the
                           increased in the last 5 years.     This is possibly due to a variety                                  GON is unknown.    Because of the deep water habitat preference
                           of factors which include better identification of the species, a                                      of sperm whales, N14PS anticipates that OCS vessel traffic
                           more efficient stranding network and an increase in mortality                                         will have minimal effects.
                           caused by shrimp trawlers, boat collisions. entanglement,


                                                            7














                         (2)  Noise disturbances from OCS oil and gas exploration and                                   regarding the effects of oil contamination on turtles has become
                              development have been identified as potential sources of                                  available.   Of particular importance was a two year research
                              impact to whales.   Considerable research emphasizing bowhead,                            project to determine the possible effects of oil on hatchling,
                              gray and humpback whale behavioral responses to vessel and                                juvenile and adult sea turtles conducted by the Florida Institute
                              aircraft noises, drilling activities and seismic surveys has                              of Oceanography (PTO 1986).    This research generated new
                              been conducted in the North Pacific.     In general, these                                experimental information on oil impacts on two selected species,
                              studies have demonstrated that whale avoidance reactions are                              the green turtle (Chelonia inydas) and the loggerhead turtle
                              limited to relatively close disturbance ranges (Malmo at al.                              (Caretta caretta)-__TFe_stuZy-oealt principally with oil exposure
                              1984), with more pronounced behavioral reactions observed on                              experiments to deter-mine the physiological and clinicopathological
                              the breeding/calving grounds (Dahlheim 1983).      In the central                         effects of oil on sea turtles.    Behavioral avoidance tests were
                              GOM, no areas of whale concentrations (feeding, breeding or                               also conducted and strategies to minimize the effects of oil
                              calving grounds) have been identified.     However, it should be                          contamination on sea turtles were recommended.
                              noted that little cetacean research has been conducted in the
                              Gulf of Mexico# and our knowledge of whales in this                                       A brief summary of the PTO (1986) study follows:
                              geographic area is extremely limited.
                                                                                                                            (1)   Experiments on the physiological and clinicopathological
                         (3)  Another potential impact to whales from the proposed                                                effects of oil conducted on juvenile loggerhead turtles
                              activities is the chance of encountering oil spills which                                           demonstrated that major body systems were adversely
                              could occur during exploration, development and production                                          affected by limited exposures to oil (South Louisiana
                              phases of oil and gas operations.     Whales may be affected by                                     Crude Oil - SLCO).   These include:   (a) changes in the
                              spilled oil in a number of ways.     Metabolic and physiologic                                      respiration in acutely oiled turtles, (b) the reddening
                              properties of the whale's skin may be impaired by toxic                                             and sloughing off of the skin of exposed turtles, (c)
                              fractions in crude oil.    Ingestion of oil would not likely                                        effects on the integumentary system (i.e., skin lesions
                              occur in sufficient quantity to kill the animals, but                                               which increase the susceptibility to infections), (d)
                              petroleum fractions are subject to bioaccumulation which                                            significant changes in the blood chemistry and
                              potentially may impact long-term survival.      Fouling bf" baleen                                  compositiont and (a) the temporary loss of salt gland
                              plates may occur, although Geraci and St. Aubin (1982)                                              function in acutely oiled turtles.
                              indicate a rapid cleaning of the plates. Eyes and sensitive
                              mucous membranes may be irritated by toxic vapors.       The                                  (2)   There were inconclusive laboratory results on determining
                              ability of holes to detect and avoid spilled oil is                                                 if young sea turtles selectively strike at tar balls
                              unknown.   Adverse effects associated with a large oil spill                                        floating on the surface of the water.
                              are more likely to be associated with the production and
                              development phases than the exploration phase.      The DEIS (MMS                             (3)   In experiments to determine the effects of an oil slick
                              1987) for the proposed oil and gas lease sales concludes                                            on the behavior of sea turtles, it was demonstrated that
                              that, based on the known distribution of whales in the GOM                                          the turtles would spend significantly more time in the
                              relative to areas being offered for lease, the chance of a                                          water column and would surface to breathe more frequently
                              whale contacting an oil spill as a result of the proposed                                           in the unoiled water.   This was attributed to the
                              activity is low.                                                                                    turtle's visual avoidance reaction to the darker oil and
                                                                                                                                  not necessarily to the chemical cues associated with the
                         Cetacean Conclusions                                                                                     petroleums.
                         NMFS concludes that the proposed activities are not likely to                                      (4)   After analyzing Florida's sea turtle stranding data
                         jeopardize the continued existence of sperm, fin, sei, right, blue                                       (1980-1984)p it was determined that 3.2% (50 turtles) of
                         or humpback whales.   The sperm whale and possibly the fin whale                                         the strandings were petroleum related.    Approximately 92%
                         are the only species likely to occur in the Gulf of Mexico with                                          of these petroleum related strandings were juveniles.
                         any regularity or abundance.    Sperm whales generally feed in deep                                      Petroleum related strandings included turtles that had
                         waters and do not routinely visit the shelf areas where most oil                                         been *fouled' in oil or had ingested petroleum residue
                         and gas activity would occur.    Little is known about fin whales in                                     such as tar balls.
                         the GOM, although their migrations also occur in deepr open waters
                         rather than along the coastlines.                                                                  (5)   Hydrocarbon analysis of some oil-fouled sea turtles
                                                                                                                                  indicat d th t most of the ingested/fouling tar came from
                         Sea Turtles                                                                                              crude o 1 ta&nker discharge.
                         Since the 1979 Biological opinion, considerable new information                                As a result of the PTO study and other related studies, it is


                                                            9

                                                                                                                                                         10


















                           b coming clear that serious adverse effects to listed sea turtles                              to the species.
                           m:y occur as a result of oil spills. The potential for impacts to
                           sea turtles is increased by the fact that oil contaminants tend to                             There is little doubt that the overall affect of OCS oil and gas
                           concentrate in areas of convergence or divergence (driftlines)                                 activities in the GON to listed species is negative.       In this
                           which also play a vital role in the early years of sea turtles                                 opinion, NMFS has discussed some of the major potential affects of
                           (Carr 1986).  Hatchlinq turtles are believed to be associated with                             these activities which include: oil/gas related oil spills,
                           sargassum rafts during  their early development, and these rafts                               collisions with offshore support vessels# platform removals, noise
                           tend to concentrate along driftlines.    Several field studies have                            disturbances from OCS oil/gas activities, offshore lighting, and
                           demonstrated that the sargassum community can be measurably                                    offshore oil/gas related debris and trash.     Considering the
                           contaminated by petroleum (Morris et &1. 1976; Burns and Teal                                  magnitude of MMS mean case scenario estimates of present and
                           1973).                                                                                         future development in the GOM, the probabilities of impacts to
                                                                                                                          listed species are high.
                           NMFS is particularly concerned with the potential impacts of a
                           major oil spill in the GOM on hatchling Kemp's ridley turtles,                                 Some other activities in the GON which have negative impacts on
                           whose distributions are believed controlled by current patterns                                listed species, but are not related to OCS oil and gas activities
                           and driftlines (Hildebrand 1982).                                                              includez commercial and recreational fishing; ocean disposal of
                                                                                                                          chemicals, radioactive wastes, munitions, etc.; marine trash and
                           MMS expects effects of oil and gas activities on sea turtles in                                debris; loss of turtle nesting beaches through development; turtle
                           the Gulf of Mexico to be moderate in the central and western Gulf                              eqg predation; oil and tar balls from natural seeps, bilge
                           and very low in the eastern GOM (MMS 1987).     The following are                              cleaning and tanker spills; non-oil and gas related vessel
                           some concerns regarding the potential impacts of GOM oil and gas                               traffic; pollution of rivers, bays, estuaries, etc.; and channel
                           activities on sea turtles.                                                                     dredging.  The additive effects of these activities plus the
                                                                                                                          potential effects of oil and gas activities may at some point
                           (1)  An increase in offshore oil and gas related vessel traffic        in                      jeopardize the potential for the survival and recovery of listed
                                the GOM increases the potential for injuries to sea turtles                               species.
                                through turtle/vessel collisions. This source of ttirtle
                                mortalities in the Gulf of Mexico has not been quantified,                                Of all the activities which may have negative impacts on listed
                                but based on records of the Sea Turtle Stranding and Salvage                              species, the only quantitative information available concerns the
                                Network (STSSN) the number of turtles with suspected                                      catch and mortality of sea turtles by shrimp trawlers.
                                propeller wounds has been increasing.     These data, however,                            Appropriate measures are being taken to minimize adverse impacts
                                could be misleading and may refle   ct an increased efficiency                            to endangered and threatened sea turtles associated with shrimp
                                of the reporting network or an increase in overall vessel                                 trawling.  The magnitude of potential impacts from other
                                traffic in the Gulf of Mexico.                                                            activities is unknowns and without this information, it     is
                                                                                                                          difficult to determine if and when a species may be jeopardized by
                           (2)  Another Dotential impact to sea turtles associated with OCS                               any single ac tivity.
                                platforms is disorientation of hatchlings, which can result
                                from offshore artificial lighting.     Newly-hatched turtles                              A final NMFS concern is the potential impacts of a major oil spill
                                utilize light (the brighter horizon) to find the ocean and                                in the Gulf of Mexico should it contact the Kemp's ridley nesting
                                this orientation continues while at sea.      While nesting in                            beaches at Tamaulipas, Mexico.    A disaster of this nature could
                                the central GON is relatively uncommont Kemp's ridley turtles                             seriously reduce the potential for survival and recovery of this
                                originating from the beaches of Rancho Nuevo, Mexico could                                species.  Oil spills can result from well blowouts, pipeline
                                potentially be affected by offshore lights.      However, this                            ruptures, leakage, spillage during transfer activities and
                                possible impact is speculative and has never been documented.                             shipping activities.   Of these activities, the most likely source
                                                                                                                          of spilled oil is from spillage during transfer and shipping
                           With the exception of abandonment, this consultation addresses all                             activities.  Well blowouts are more likely to occur during the
                           phases of oil and gas activities in the GOM including ongoing and                              development and production phase than during exploration
                           anticipated future production through the year 2023, therefore it                              activities. Since the proposed lease sales include the entire
                           is neces:darytto examine not only the impacts of the proposed sales                            GOM, it is possible that an oil spill in the western Gulf could
                           but the   di ive impacts of all other oil and gas activities in                                impact Mexican beaches. However, based on MMS oil spill risk
                           the GON. it is also necessary to consider the potential impacts                                analysis and trajectory calculations for development and
                           of other activities in the GON.    As the government agency                                    production in the western GOM, the risk of spilled oil contacting
                           responsible for protecting listed marine species, we Must attempt                              the ridley nesting beach in Rancho Nuevo is extremely remote.
                           to determine at what point the additive effects of all activities
                           impinging on the survival of listed species constitutes a jeopardy


                                                                                                                                                         12

















                         Sea Turtle Conclusions                                                                                            INCIDENTAL TAKE STATEMENT
                         It is our opinion that the OCS oil and gas exploration, production
                         and development activities for the proposed lease sales are not                                Section 7(b)(4) of the Endangered Species Act requires that when a
                         likely to jeopardize the continued existence of the Kemp's ridley,                             proposed agency action is found to be consistent with Section
                         loggerhead, green, hawksbill or leatherback turtle.                                            7(a)(2) of the Act and the proposed action may incidentally take
                                                                                                                        individuals of listed species, NMFS will issue a statement that
                                                                                                                        specifies the impact (amount or extent) of such incidental taking
                                                                                                                        and the terms and conditions that must be followed.       Only
                                                                                                                        incidental taking by the Federal agency or applicant that complies
                                                                                                                        with the specified terms and conditions of this statement is
                                                                                                                        authorized and exempt from the taking prohibition of the ESA.

                                                                                                                        No records of sea turtle take in the course of oil and gas
                                                                                                                        activities have been reported. However, there is a growing body.
                                                                                                                        of evidence that oil and gas related activities (i.e. exposure to
                                                                                                                        oil spills, vessel collisions, disorientation by platform lights,
                                                                                                                        etc.) may adversely affect sea turtles.      These potential impacts
                                                                                                                        have been addressed in the consultation for oil and gas lease
                                                                                                                        sales 113, 115 and 116. NMFS does not anticipate any sea turtle
                                                                                                                        take as a result of exploration, production and development
                                                                                                                        activities associated with lease sales 113, 115 and 116.        As a
                                                                                                                        condition of this statement, if a sea turtle is injured or killed
                                                                                                                        during any phase of the proposed activity, the incident must be
                                                                                                                        reported to the NMFS Southeast Reqional Director as soon as
                                                                                                                        possible.   NMFS will cooperate with MMS in a review of the
                                                                                                                        incident to determine the need for developing appropriate
                                                                                                                        mitigation measures.

                                                                                                                        Section 7(b)(4)(C) of the ESA specifies that in order to provide
                                                                                                                        an incidental take statement for an endangered or threatened
                                                                                                                        species of marine mammal, the taking must be authorized under
                                                                                                                        Section 101(a)(5) of the marine mammal Protection Act of 1972
                                                                                                                        (MMPA).   Since no taking incidental to the proposed activity has
                                                                                                                        been requested or authorized under Section 101(a)(5) of the MMPA,
                                                                                                                        no statement on incidental take of endanqered or threatened marine
                                                                                                                        mammals is provided, and no take is authorized.















                                                                                                                                                         14


                                                          13




                                                                                                                                                                                                            tZ




















                                      CONSERVATION RECOMMENDATIONS                                               (d)  Relationships between oil and gas platforms and
                                                                                                                      sea turtles/marine mammals should be assessed on a
                                                                                                                      temporal and spatial basis.
                       In formulating our opinion on the potential impacts to listed
                       species of oil and gas related activities, NMFS used the best                             (a)  In conjunction with the existing sea turtle
                       available information. However# to adequately evaluate the                                     stranding network, additional studies to determine
                       probable impacts of various oil and gas development/production                                 "cause of death" are needed. If strandings could
                       scenarios, quantitative information is essential. Specifically,                                be attributed to specific activities, potential
                       for each listed species we need to know: (1) what is the existing                              impacts of these activities might be quantified.
                       population size, (2) how many individuals may be affected as a
                       result of the proposed activity, and (3) how many mortalities are
                       expected to occur as a result of all other non-related
                       activities? With this minimal information, it is possible to make
                       a subjective judgment concerning whether an activity might
                       jeopardize the continued existence of a species.

                       The NKFS acknowledges the past and present research efforts funded
                       by MtIS which address oil and gas related impacts to endangered and
                       threatened species. while these studies have provided some
                       valuable information, many questions remain unanswered. The
                       following are NMFS research recommendations for future studies.
                       Data derived from such studies will aid in our interagency
                       responsibilities to ensure that oil and gas development will not
                       jeopardize protected species.

                       (1)  NMFS considers the scarcity of basic biological
                            information on listed species to be the major limiting
                            factor in our ability to adequately assess the
                            potential impacts of activities in the GOM. Studies of
                            age, growth, survival, distribution, seasonality,
                            movements, migrations, habitat, populations, etc. for
                            all listed species are needed. An overall research
                            plan including Federal agencies (NMFS, FWS, MMS,
                            COE, etc.). States, private institutions and
                            universities should be developed to prioritize and fund
                            needed research.

                       (2)  Some specific recommendations for research as related
                            to GON OCS oil and gas activities are:

                            (a)  Tar samples collected from stranded turtles,
                                 beaches, and driftlines should continue to be
                                 analyzed to determine their source.

                            (b)  Research is needed to identify neonatal turtle
                                 habitatt particularly for the Kemp's ridley, and
                                 to determine the extent to which these turtles are
                                 associated with driftlines.

                            (c)  The possible effects of chemical dispersants on
                                 marine mammals and sea turtles should be
                                 determined.




                                                       15                                                                                  16


















                                                     REFERENCES                                                        Carr, A. P. and L. Ogren. 1960. The ecology and migrations
                                                                                                                            of sea turtles 4. The green turtle in the Caribbean
                                                                                                                            Sea. Bull. Amer. Mus. Nat. Mist. 131(1): 1-48.

                           Anonymous. 1985.    Offshore Georgia: Calving ground for an                                 Carr, A., L. Ogren and C. NcVea. 1980. Apparent hibernation
                                 Endangered Species. Coastlines, Vol. 8, No.                                                by the Atlantic loggerhead turtle of Cape Canaveral,
                                                                                1, pp 8-11.                                 Florida. Siol. Conserv. 191 7-14.
                           Babcock, H. L. 1937. The sea turtles of the Bermuda Islands,                                Carr, A. and D.K. Caldwell. 1956. The ecology and migrations
                                 withia survey of the present state of the turtle                                           of sea turtles 1. Results of field work in Florida,
                                 fish ng industry. Proc. Zool. Soc. Lond. 107: 595-601.                                     1955. Amer. Mus. Novitates 1793: 1-23.
                           Bacon, P., F. Berry, K. Bjorndal, H. Hirth, L. Ogren and M.                                 Carr, 0. and P. H. Carr. 1976. Survey and reconnaissance of
                                 Weber. 1984. Proceedings of the Western Atlantic                                           nesting shores and coastal habitats of marine turtles
                                 Symposium. Vol. I San Jose, Costa Rica, 17-22 July                                         in Floridat Puerto Rico and the U.S. Virgin Islands.
                                 1983. IOCARIBE and FAD. RSnAS Printing, Miami,                                             NMFS report. 34pp.
                                 Florida. 306 pp.
                           Berzin, A.A. 1971. Kashalot (The Sperm Whale). lzd.                                         Chavez, H. 1968. Mercado y recapture de individuos de
                                                    h                                                                       tortugs lore Lepidochelys kempi (Garman), Inst. Nac.
                                 -Pishcevaya Promys lennost" Moscow. (In Russian,                                           Inv. Biol. Pes., Mexico, Vol 19, 28pp.
                                 translated by Israel Program of Scientific
                                 Translations, 1972, 394p., avail. U.S. Dept. of                                       Chavez, H. 1969. Tagging and recapture of the Lora turtle
                                 Commerce, National Technical Information Service,                                          (Lepidochelys kempi). International Turtle Tortoise
                                 Springfield, VA. as TT71-501521.                                                           Society Journal 3tl4-19.
                           Braham, H.W. 1984. The status of endangered whales: An                                      Dobie, J. L., L. H. Ogren and J. F. Fitzpatrick, Jr. 1961.'
                                 overview. Marine Fisheries Review, 46(4);2-6.                                              Food notes and records of the Atlantic ridley turtle
                                                                                                                            (Lepidochelys kempi) from Louisiana. Copeia 1961(l):
                           Burns, K.A. and J.M. Teal. 1973. Hydrocarbons in the Pelagic                                     109-110.
                                 Sargassum Community. Deep Sea Research 20:207-211.
                                                                                                                       Dahlh7i           '3 Acouutictl !tudies on the gray whale
                                                                                                                             Ems' M!%t'9 ;obu  8   9) n aguna San Ignacio, Baja
                           Byles, R. Personal Communication. U.S. Fish and Wildlife                                            chr c ius        t
                                 Service.                                                                                   California Sur, Mexico. Final report to the Department
                           Caldwell, D.K., M.C. Caldwell and D.W. Rice. 1966. Behavior                                      of2Peace, Mexico City, Mexico. Section II-Permit No.
                                 of the Sperm Whale, Physeter catodon L.    In: K.S.                                        24 .2-00227-140. 52pp.
                                 Norris ad. Whales, dolphins and porpoises. univ.                                      DeSilva, G.S. 1982. The status of sea turtle populations in
                                 California Press, Berkley, CA. 678-717.                                                    East Malaysia and the South China Sea.     pp. 327-337 In:
                                                                                                                            Biology and Conservation of Sea Turtles. K.A. Bjorndal
                           Carr, A. F. 1952. Handbook of turtles. Ithaca, New York:                                         (ad.). SmIthsonian Institution Press, Washington D.C.
                                 Cornell University Press.
                                                                                                                       Doughty, R.W. 1984. Sea turtles in Texas: A forgotten
                           Carr, A. F. 19S4. The passing of the fleet. A.I.B.S. Bull.,                                      commerce. Southwestern Historical Quarterly
                                                                                                                            88(l)t43-70.
                           Carr, A. F. 1963.  Panspecific reproductive convergence in                                  Duellman, W. E. 1961. The amphibians and reptiles of
                                 Lepidochelys kempi. Ergebn. Biol. 26: 298-303.                                             Michoacan, Mexico. Publ. Univ. Kans. Mus. Nat. Mist.,
                           Carr, A. 1986. Rips, FADS and little loggerheads. Rio                                            15: 1-149.
                                 Science 36(2): 92-100.                                                                Ehrhart, L. M. 1979. A survey of marine turtle nesting at
                           Carr, A. P., M. H. Carr and A. B. Meylan. 1978. The ecology                                      Kennedy Space Center, Cape Canaveral Air Force Station,
                                 and migrations of sea turtles. 7. The western Caribbean
                                 green turtle colony. Bull. Amer. Kus. Nat. Mist.
                                 162(l): 1-46.


                                                                                                                                                      is
                                                           17




                                                                                                                                                                                                       tZ















                                                                                                                                                                                                               00


                          Hildebrand, H. H. 1963. Haliazgo del area de anidacion de I&                                    Marcuzzi, G. and G. Pilleri. 1971. On the zoogeography of
                               tortugs marina 'lora', Lepidochelys kempi (Garman), an                                           Cetacea. pp 101-170 In: Investigation on Cetacea, Vol
                               la cost& occidental del Gulfo do Mexico. Ciencia, mex                                            3. G. Pilltri (ed.). University of Berne, Institute for
                               22(4): 105-112.                                                                                  Brain Anatomy, Berne, Switzerland.
                          Hildebrand, H.H. 1980. Report on the incidental capture,                                        Mendonca, M. T. and L. M. Ehrhart. 1982. Activity,
                               harassment and mortality of sea turtles in Texas.                                                population size and structure of immature Chelonia
                               Report to NMFS Pascagoula, MS 34pp.                                                              mydas and Caretta caretta in Mosquito Lagoon, Florida.
                                                                                                                                Copoia (1982)1: 161-167.
                          Hildebrand, H. H. 1982. A historical review of the status of
                               sea turtle populations in the western Gulf of Mexico.                                      Mexico. 1966. Instituto Nacional do Investigaciones
                               pp 447-4S3 In: Biology and conservation of sea turtles.                                          Biologico-Posqueras. Programa nacional do marcaco de
                               K. A. Bjorndal. (ad.) Smithsonian Institution Press,                                             tortugas marinas. Mexico, INIBP: 1-39.
                               Washington, D.C.
                                                                                                                          Minerals Management Service, 1987. Draft environmental
                          Hirth, H. F. 1971. Synopsis of biological data on the green                                           assessment for proposed central Gulf of Mexico OCS
                               turtle Cholonia mydas(Linnaeus) 17S8, FAD Fisheries                                              sulphur/salt lease sale. U.S. Department of Interior.
                               Synopsis No. 85; 1-77.
                                                                                                                          Mizroch, S.A., D.W. Rice and J.M. Breiwick. 1984. The blue
                          Hooper, C.H. (ed.) 1981. The IXTOC I oil spill: The federal                                           whale, Balaenoptera musculus. marine Fisheries Review
                               scientific response. NOAA Special Report from NOAA                                               46(4)s 15-19.
                               Hazardous Materials Response Project. 202pp.
                                                                                                                          Morris, B.F., J. Cadwallader, J. Geiselman and J.N. Butler.
                          Jeffrey, L.M., W.E. Pequegnat, E.A. Kennedy, A. Vos and       B.M.                                    1976. Transfer of petroleum and biogenic hydrocarbons
                               James. 1974. Pelagic tar in the Gulf of Mexico and                                               in the sargassum community. pp 235-259 In: Marine            . .
                               Caribbean Sea. In: Marine pollution monitoring                                                   Pollutant Transfer. H.L. Windom and R.A. Duce (eds.).
                               (petroleum), proceedings of a symposium and workshop                                             Lexington Books.
                               held at the National Bureau of Standards# Gaithersburg,
                               MD., May 13-17, 1974.    NBS Spec. Pub. 409. U.S.                                          Mortimer,J. 1982. Feeding ecology of sea turtles.        pp
                               Government Printing office, Washington D.C. 316pp.                                               103-109 In: Biology and conservation of sea turtles. K.
                                                                                                                                A. Sjorndal (ad.) Smithsonian Institution Press,
                          Klima, E. 1966. Summary report on biological impacts of                                               Washington, D.C.
                               offshore petroleum platform severance using explosives.
                               Unpub. N?iFS Report$ Galveston, TX. 7pp.                                                   Neill, W. T. 19S8. The occurrence of amphibians and reptiles
                                                                                                                                in salt water areas, and a bibliography. Bull. Mar.
                          Kraus, S.D., J.H. Prescott and A.R. Knowlton. 1986.                                                   Sci. Gulf Caribb. 8: 1-97.
                               wintering right whales (Eubaleana glacialis) along the
                               southeastern coast of the United States, 1984-1996. New                                    Owens, D. 1983. Oil and sea turtles in the Gulf of Mexico: A
                               England Aquarium report submitted to: World Wildlife                                             proposal to study the problem. pp 34@49 In! Proceedings
                               Fund - U.S. and Minerals Management Service. 15pp.                                               of a workshop on cotaceans and sea turtles in the Gulf
                                                                                                                                of Mexico. Minerals Management Service and U.S. Fish
                          Lazall, J. 0. 1980. New England waters: critical habitat       for                                    and Wildlife Service FWS/OBS-83/03.
                               marine turtles. Copoia 1980(2): 290-295.
                                                                                                                          Parsons, J. J. 1962. The green turtie and man. Gainesville,
                          Leary, T.R. 19S7. A schooling of leatherback turtle,                                                  University of Florida Press.
                               Dermochelys coriacea coriacea, on the Texas coast.
                               Copoia 3:232.                                                                              Peters, J. A. 1954. The amphibians and reptiles of the coast
                                                                                                                                ;nd,coa;t:l,sierra of Michoacan, Mexico. Occ. Pap. Mus.
                          Lutcavage, M. and J.A. Musick. 1985. h9pects of the biology                                            oo . 5 4    -37
                               of sea turtles in Virginia. Copeia 1985(2);449-456.
                                                                                                                          Pritchlrd,SP;tC.MH 1969i4ei-turtles of the Guianas. Bull.
                          Mann, T.M. 1977. Impact of developed coastline on nesting                                             F a.  t a u;. 13(           139.
                               and hatchling sea turtles in southeastern Florida. M.S.
                               Thesis, Florida Atlantic University.



                                                           19                                                                                              20



















                      Pritchard, P. C. H. 1969. The survival status of ridley sea
                           turtles in American waters. Biol. Cons. 2(l): 13-17.

                      Pritchard, P. C. H. and R. Marquox. 1973. Kemp's ridley
                           turtle or Atlantic ridley. I.U.C.N. Monograph No. 2,
                           Morgos, Switzerland.

                      Rabelais, S.C. and M.N. Rabelais. 1980. The occurrence of
                           sea turtles on the south Texas coast. Contr. Mar. Sci.
                           23: 123-129.

                      Rebel, T. P. 1974. Sea turtles and the turtle industry of
                           the West Indiest Florida and the Gulf of Mexico. Univ.
                           Miami Press, Coral Gables, FloridA.

                      Ross, J. P. 1982. Historical decline of loggerhead, ridley
                           and leatherback sea turtles. pp 185-195 In: Biology and
                           conservation of sea turtles K. A. Bjorndal (ad.)
                           Smithsonian Institution Press, Washington, D.C.

                      Schmidly, D.J. 1981. Marine mammals of the southeastern
                           United States coast and the Gulf of Mexico. U.S. Fish
                           and wildlife Service, Office of Biological Services,
                           Washington, D.C. FWS/OBS-80/41. 163pp.

                      Schulz, J. P. 1975. Sea turtles nesting in Surinam. Sool,
                           Verh. 143: 1-143.

                      Shoop, C., T. Doty and N. Bray. 1981. Sea turtles in the
                           region between Cape Hatteras and Nova Scotia in 1979.
                           pp IX 1-8S In: A characterization of marine mammals
                           and turtles in the mid- and north-Atlantic areas of the
                           U.S. outer continental shelf: Annual report for 1979.
                           Univ. Rhode Island, Kingston.

                      Slijper, E.J. 1979. Whales. Cornell University Press,
                           Ithaca, N.Y. SlIpp.

                      Underwood# G. 1951. Introduction to the study of Jamaican
                           reptiles. Part 5. Nat. Hist. Notes Nat. Hist. Soc.
                           Jamaica 46t 209-213.

                      Watkins, N.A. 1977. Acoustic behavior of sperm whales.
                           Oceanus 20(2)1 50-58.

                      Woolfenden, G.R. 1903. Rare, threatened and endangered
                           vertebrates of southwest Florida and potential OCS
                           activity impacts. FWS/OBS-82/03. Report to National
                           Coastal Ecosystems Team. Contract No.
                           92375-9313-000-33.







                                                   21





                                                                                                                                                                                           tZ





















                       U.S. Fish and Wildlife Service

                            Biological Opinion

                          Central Gulf of Mexico

                                 Sale 139














                                                                                                           ua@         i                      addition, this Opinion provides an informal conference for the proposed
                                            United States Department of the Interior                      2&r@@                               Gulf of Mexico sturgeon and advisory guidance for the candidate snowy
                                                         FISH AND WILDLIFE SERVICE                                                            plover. Sea turtles have split jurisdiction between the National Marine
                                                              75 SPRING STREET. S.W.                       mm@w                               Fisheries Service and the Fish and Wildlife Service; therefore, this
                                                               ATLANTA. GEORGIA                                  IN    a                      Opinion will only cover that portion of the species' life history that
                                                                      30303                                                                   occurs an land.
                                                                   MAR 15 W1                                                                  Figure 1 shows the boundaries of the Central Gulf of Mexico Planning Area
                                                                                                                                              for which this Opinion was written. The Planning Area is offshore of the
                                 Memorandum                                                                                                   States of Louisiana, Mississippi. and Alabama.
                                 To,        Assmiate Director for Offshore Leasing. Minerals Management                                       Opinion Preparation and Tnformarloo Assumptions;
                                            Service, Washington, D.C.                                                                         All previous Opinions for Outer Continental Shelf oil and gas activities in
                                            Attn. Dr. Robert Middleton                                                                        the Central Gulf of Mexico were reviewed in preparation of the current
                                 From,   e@@\Q ional Director, Fish and   Wildlife Service. Atlanta, Georgia                                  Opinion. Ms. Lorna Patrick, Panama City. Florida. Field Office. prepared
                                            (AWE/TS)                                                                                          the Opinion In consultation with the Fish and Wildlife Service's Washington
                                                                                                                                              Office, Southeast Regional Office, and Jacksonville. Florida; Lafayette,
                                 Subject@ Biological Opinion on Outer     Continental Shelf Oil and Gas                                       Louisiana, Jackson. Mississippi; and Daphne. Alabama. Field Offices; and
                                            Leasing.                                                                                          coastal national wildlife refuges in Alabama, Mississippi. and Louisiana;
                                                     Exploration. Development. Production, and Abandonment in                                 and the Washington and the Gulf of Mexico Regional Offices of the Minerals
                                            the Central Gulf of Mexico, Lease Sale 139                                                        Management Service. In addition. the Minerals Management Service furnished
                                                                                                                                              the preparer environmental analyzes, oil spill analyses. other documents
                                 Introduction                                                                                                 and naps which were used in preparing the Opinion.
                                 The Minerals  Management Service, by memorandum dated October 4. 1990,                                       Exploration development. and production requires certain onshore support
                                                                                                                                              factlities @ncluding office space, helicopter And fixed-ing Aircraft
                                 requested formal Section 7 consultation for Lease Sale 139 and an                                            facilities, navigation channels and docks for boating activities, platform
                                 unnumbered sale encompassing blocks in the Central and Western Gulf of                                       And drilling rig construction yards, pipelines, oil and gas processing and
                                 Mexico Planning areas. respectively. This consultation will include all                                      separating facilities, refineries, And supply bases. Oil and gas
                                 aspects of oil and gas exploration, development. production, and                                             activities in the Central Gulf of Mexico began more than 30 years ago;
                                 abandonment activities as requested by the Minerals Management Service for                                   therefore. necessary onshore facilities to support those activities are
                                 the Central Gulf of Mexico Planning Area. Our Southwestern Regional Office                                   already in place and no major new facilities are anticipated as a result
                                 in Albuquerque. New Mexico. will respond to your request regarding the                                       Sale 139. Due to the uncertain nature of oil and gas supply and demand,
                                 unnumbered Western Gulf of Mexico Lease Sale.                                                                companies Are generally unwilling to construct new facilities. They prefer
                                 The Fish and Wildlife Service Concurs that the current Biological Opinion                                    instead to use existing areas and facilities.
                                 (Opinion) for the Central Gulf of Mexico Planning Area issued on July 18.                                    At the present, there are numerous onshore facilities throughout the Gulf
                                 1989. and revised on August 25, 1989, is generally up-to-date. However,                                      of Mexico being used for Outer Continental Shelf oil and gas activities.
                                 the Fish and Wildlife Service believes that the availability of seasonal                                     Should the use of these facilities be changed or additional onshore
                                 oil-spill risk estimates require a re-evaluation of some species.                                            facilities be needed which may affect listed species or their habitats,
                                 Opinion Coverage                                                                                             consultation would need to be rainitiated.
                                                                                                                                              Potential for large oil spills (greater than or equal to 1,0W barrels)
                                 The Central Gulf  of Mexico Planning Area proposed for leasing under Sale                                    resulting from oil and gas activit-as in the Central Gulf of Mexico is
                                 139 encompasses all unleased blocks in the planning area consisting of                                       unlikely. Small chronic spills can and often do occur in the vicinity )f
                                 approximately 48 million acres.                                                                              drilling and production platforms . These spills are usually locali=ed And
                                 The following Opinion, therefore. covers all phases of Outer Continental                                     are due to leakage from service and support vessels and small diameter
                                 Shelf oil and gas activity including leasing. exploration. development.                                      pipes associated with oil production. including fuel transfer and rout:@ne
                                 production, and abandonment for the Central Gulf of Mexico Area. In                                          operations. The Minerals Management Service does not regulate the

                                                                                                                                                                                   z




                                                                                                                                                                                                                                                 tIz









                            transportation of oil and gas from the production sites or refineries as                                       oil. Because Louisiana crude evaporates rapidly, slicks observed in gulf
                            final products   and therefore. is not responsible for accidents or spills                                     waters have disappeared within days. Very few oil slicks have ever been
                            that occur during these activities. However. the agency is responsible for                                     tracked for more than 30 days. Spills from the Torrey Canyon, Amoco Cadiz,
                            overseeing accidents or Spills that may occur in the lease blocks. Species                                     and Ixtoc (which released oil over a long time period) remained on the sea
                            in the vicinity of these small spills are usually those under the                                              surface longer than 30 days. but their volume was many times larger than
                            jurisdiction of the National Marine Fisheries Service. An exception to                                         the average spill. In contrast. a slick from South Pass Block 60 of
                            this is the Gulf of Mexico sturgeon which makes marine migrations during                                       42,000 barrels. spilled on August 2. 1973. was reported dissipated with
                            the winter months.                                                                                             only small patches remaining after 5 days. Based on the above, 10 days is
                                                                                                                                           chosen as the most likely sea surface residence time. Assumptions
                            The following Information was used In preparation of this Opinion regarding                                    regarding dominant weathering processes indicate that after 10 days the oil
                            potential oil spill Impacts on endangered and threatened species in the                                        properties have changes extensively and the original volume has decreased
                            Central Gulf of Mexico Planning Area. South Louisiana crude is a typical                                       greatly. The floating oil is largely devoid of its volatile (acutely
                            crude oil from the Central Gulf of Mexico. It is an oil that is light-                                         toxic) components and is gradually forming emulsions (U.S.Minerals
                            weight and relatively nonpersistent. Historically, the vast majority of                                        management service 1990).
                            oil spills in the Gulf at Mexico from Outer Continental Shelf operations
                            have consisted of South Louisiana crude.                                                                       This Opinion does not provide an assessment for oil spill cleanup
                                                                                                                                           activities on listed. proposed, or candidate species. The Fish and
                            A review of 92 crude oils produced from fields on the Central Gulf of                                          Wildlife Service does not believe it is practical to provide a generic oil
                            Mexico Planning Area outer continental shelf and coastal Louisiana shows                                       spill cleanup evaluation. The Opinion can only address those activities or
                            that a majority (51 percent) of the crude oils have API gravities between                                      permits controlled by or under jurisdiction of the Minerals Management
                            33' and 38' API. However. the range of variability is great. with the                                          Service. This eliminates transportation related oil spills outside
                            lowest being 21.6' and the highest being 47.3' API Minerals Management                                         Minerals Management Service control or authority and oil spill cleanup
                            Service 1990). There have been few very large oil spills (greater than                                         outside the leased blocks. The U.S. Coast Guard and U.S. Environmental
                            10,000-barrels)from Central Gulf of Mexico outer continental shelf-related                                     Protection Agency would have jurisdiction in most instances of spilled oil.
                            operations. These spills include a 160,638-barrel spill from in anchor
                            damaged pipeline in block 73, West Delta Area on October 17, 1967. and                                         Offshore oil and gas structure removal (abandonment) has become a concern
                            another 19,833-barrel spill from an anchor damaged pipeline in block 317.                                      n recent years in regard to impacts on marine mammals and endangered and
                            Eugene Island Area on April 17, 1974. Two platform blowouts occurred in                                        threatened species. Historically. approximately 55 to 65 of these
                            1970, a 53,000-barrel spill at block 26, South Timbalier Area and a                                            structures are removed annually from offshore waters. The structures are
                            20,000-barrel spill at block 41. Main Pass Area. No tanker spills related                                      removed by nonexplosive or explosive methods. The only species under the
                            to Outer Continental Shelf activities have been reported for the Central-                                      jurisdiction if the Fish and Wildlife Service that could potentially be
                            Planning Area (U.S. Minerals Management Service 1990).                                                         affected by structure removal is the Gulf of Mexico sturgeon.
																											 
                            A number of processes occur when oil is spilled in water. altering the                                         Public and private interests have indicated that debris and trash
                            chemical and physical characteristics of the original oil mixture almost                                       associated with oil and gas operations (oil drums, large plastic sheeting
                            immediately.  Collectively, these are referred to as weatherng or aging of                                     and containers. computer read-write rings. seismic markers,styrofoam
                            the oil and will determine, along with physical oceanography, the late of                                      floats, pipe-thread protectors. diesel filters. and hard hats) is a serious
                            the spilled oil. Weathering involves a number of physical/ chemical and                                        and chronic problem on major recreational beaches, national seashores, and
                            biological processes that change the characteristics of the crude oil                                          national wildlife refuges In the Western and Central Gulf of Mexico
                            mixture and reduce trio concentration of oil components in the slick. These                                    (U.S. Minerals Management Service 1990; Wiggington 1990). Removal,
                            processes include evaporation. dispersion. dissolution. emulsification,                                        analysis, and disposal of 55-gallon drums along South Texas teaches cost
                            biodegradation. photo-oxidation, sinking. and sedimentation. Any or all of                                     the Federal government nearly $400,000 In 1985. Over one-half of the 300
                            these processes can be expected to operate an spilled oil. Their relative                                      drums whose contents were analyzed in 1985 were found to contain hazardous
                            importance is largely dependent on oceanographic and meteorological                                            materials. thereby, posing potential health hazards to beach users, marine
                            conditions at the time of the spill. Eventually. a tar-like residue may be                                     resources, and wildlife. Other impacts caused by marine debris and trash
                            left, which would break up into tar lumps or tar balls (U.3. Minerals                                          include entanglement of birds, fish. sea turtles, and marine mammals in
                            Management Service 1990).                                                                                      plastic rope. strips, or netting and the ingestion of plastic bags,
                                                                                                                                           sheeting. 6-pack rings. and styrofoam particles (U.S. Minerals Management
                            Spilled Louisiana crude disperses and degrades rapidly under the influences                                    Service 1990).
                            of the Gulf of Mexico's warm climatic conditions and the properties of the


                                                                 3                                                                                                               4
 







                               Because of increased concern with the prevalence and effects of persistent                                    1986. and June 22. 1987. concluded that formal consultation need not be
                               marine debris both offshore and on coastal beaches. the Minerals Management                                   reinitiated. The above referenced Opinions covered only oil and gas
                               Service issued a special advisory (NTL 86-11) In 1986 strongly encouraging                                    leasing and exploration. Consultation was reinitiated in January 1989, to
                               the oil and gas industry to take special educational. operational, and                                        include all phases of Outer Continental Shelf oil and gas activities
                               awareness measures designed to reduce or eliminate the oil and gas                                            Consisting of leasing. exploration. development. production, and
                               industry's contributions to marine debris in the Gulf of Mexico                                               abandonment. This resulted in an Opinion dated July 18, 1989, and revised
                               (U.S. Minerals Management Service 1990). In addition. the Minerals                                            on August 25. 1989. The most recent Opinion and review by the Fish and
                               Management Service has promulgated regulations (30 CFR 250.40) to assure                                      Wildlife Service on July 26, 1990. concluded that formal consultation need
                               lessees do not create conditions that will pose an unreasonable risk to                                       not be reinitiated.
                               public health, life, property. aquatic life. wildlife. recreation,
                               navigation. commercial fishing, or other uses of the ocean during offshore                                    Biological Information
                               oil and gas operations. The rules also prohibit the disposal of equipment,
                               cables. chains, containers, or other materials into offshore waters.                                          The following species are included in this Opinion as being potentially
                               Portable equipment, spools or reels, drums. pallets, and other loose Items                                    affected by the proposed actions.
                               weighing 40 pounds or more must be marked in a durable manner with the
                               owner's name prior to use or transport over offshore waters. Smaller                                          Federal Listing in Each State
                               objects must be stored in a marked container when not in use. Should
                               equipment, material. containers. drums. or other items be lost overboard,                                     Listed Species                           Louisiana		Mississippi	     Alabama
                               they are to be recorded an the facility's daily report and reported to the
                               Minerals Management Service (U.S. Minerals Management Service 1990).                                          Brown pelican (Pelecanus occidentalis)        E             E			 --	
                                                                                                                                             Bald eagle (Halzaeecus leucocephalus)         E             E			 E
                               The Marine Pollution Research and Control Act (MARPOL) of 1987 is a recent                                    Piping plover (Charadrius melodus)            T             T			 T
                               United States law implementing Annex V of the International Convention for                                    Arctic peregrine falcon
                               the Prevention of Pollution from Ships. Under provisions of the law. all                                         (Falco peregrinus tundraus)                T             T			 T
                               ships and watercraft, including all commercial and recreational vessels,                                      Loggerhead sea turtle (Caretta caretta)       E             E			 E
                               are prohibited from dumping plastics at sea. The law also severely                                            Alabama beach mouse
                               restricts the dumping of other vessel generated garbage and solid waste                                         (Peromyscus polionotus ammobatas)          ----		   ----		 E,CH	
                               items both at sea and in United States navigable waters. Interum final                                        Perdido Key beach mouse
                               rules explicitly state that fixed and floating platforms or all. drilling                                       (Peromyscus polionotus trissyllepsis)      ---- 		   ----		 E,CH
                               rigs, manned production platforms, and support vessels operating under a									  
                               Federal oil and gas lease are required to develop Waste Management Plans                                     Proposed Species
                               (U.S. Minerals Management Service 1990).                                                                      Gulf of Mexico sturgeon
                                                                                                                                                (Acipenser exychynchus desotoi)             PT            P			 PT
                               In the Central Gulf of Mexico Planning Area, staff at the Breton National								  
                               Wildlife Refuge has noted a continuing accumulation of oil and gas related                                   Candidate Species
                               refuse on the Breton refuge beaches. Hard hats and a variety of Plastic								  
                               containers are routinely observed in what Is considered some of the United								  
                               States' most productive tern colonies (Wigginton 1990). Although marine                                      Southeastern snowy plover
                               trash may not be a major factor in the continued existence of any listed                                         (Charadrius alexandrinus tanulrostris)       C		    C			 C	
                               species in the area, it has become a justified concern In regard to										  
                               protected species' management.																  
                                                                                                                                            E  - Endangered
                               Consultation History - Central Gulf of Mexico                                                                T  - Threatened
                                                                                                                                            CH - Critical Habitat
                               The original Opinion for Outer Continental Shell oil and gas activities                                      -- - Not listed for that State
                               in the Gulf of Mexico was submitted by the Fish and Wildlife Service on                                      P  - Proposed
                               April 10. 1979. Consultation for the Central Gulf of Mexico Planning                                         C  - Candidate
                               Area was reinitiated in November 1981. which resulted in an Opinion dated
                               June 30. 198Z. which was amended October 09, 1982. Subsequent reviews of
                               Opinions by the Service dated April 9, 1984, January 15, 1985, January 29.




                                                                  5                                                                                                                 6
 









                                The following other species have been considered in this consultation.                                                 refuge more during the winter months and the coastal barrier island during
                                                                                                                                                       the spring. They suspect that the majority of the pelican that use the
                                They are the American peregrine falcon (Falco Peregrinus anatum, the												   
                                Eskimo curlew (Numenius borealis), American alligator (Alligator                                                       refuge are Immature and nonbreeding birds (Wigginton 1990).
                                mississippionsis). green sea turtle (Chelonia avdas), leatherback sea         								  
                                turtle (Dermochelys coriacea). hawksbill sea turtle (Eretmochelys                                                  Brown pelicans use the water around Breton National Wildlife Refuge
                                imbricata                                         kempii). least tern                                                  (St. Bernard and Plaquemines Parishes) as loafing. feeding, and nesting
                                         , Kemp's ridley sea turtle (Lapidochelys 												   
                                (Sterna antillarun). red wall. (Canis rutus). and West Indian manatee                                                  areas. Flocks typically containing 50 to 100 birds are routinely observed
                                (Trichechus manatus).                                                                                                  by refuge staff on or near all islands in Breton and Chandeleur Sound
                                Existing and proposed oil and gas activities are not expected to impact the                                            (Curlew. Grand Gosier, and Breton Islands) (Wigginton 1990).
                                American peregrine falcon or the Eskimo curlew or their habitat needs. The                                             Over the past 5 years, brown pelicans have continued to increase in numbers
                                American alligator has been reclassified as 'threatened due to similarity                                              in Breton and Chandeleur Sound. The refuge's 1990 annual survey nest count
                                of appearance" for enforcement purposes, but is not biologically endangered                                            recorded 1,331 nests on North Island. Approximately 1,500 adult brown
                                or threatened. The green. leatherback. hawksbill. and Kemp's ridley sea                                                pelicans were observed during the count in and around the island: and on
                                turtles are not known to nest on beaches within the Central Gulf of Mexico                                             North Gosier Island. a new pelican colony was established and 52 nests with
                                Planning Area.                                                                                                         eggs were counted In June 1990 (Wigginton 1990).
                                The least tern is listed as endangered in Louisiana and Mississippi except                                             The brown pelican nests In colonies on small coastal islands in salt and
                                within 50 miles of the coast. The tern freely mixes with other terns and                                               brackish waters. Nests are constructed from available vegetation. The
                                shorebirds along the coast. The red wolf has been placed on Horn Island                                                major food of the pelican is fish, including menhaden, mullet, sardines
                                off Mississippi (national seashore) for captive breeding purposes because                                              and pinfish. The pelican catches these fish by plunge-diving in coastal 
                                of the need for isolation. The occurrence of the manatee in coastal                                                    waters. Brown pelicans are rarely found away from saltwater and typically
                                Central Gulf of Mexico waters is rare. It is the Fish and Wildlife                                                     do not venture more than 20 miles (32 kilo-meters) out to sea. Extensive
                                Service's Opinion that existing and proposed oil and gas leasing,                                                      use of pesticides which were ultimately ingested by the brown pelican has
                                exploration. development, production, and abandonment activities in the                                                been noted as the primary cause of decline of the species (U.S. Fish and
                                Central Gulf of Mexico Planning Area are not likely to jeopardize the                                                  Wildlife Service 1989b).
                                continued existence of these species or destroy or adversely modify their
                                critical habitat. Further, if significant new information not considered                                               The brown pelican is extremely susceptible to disturbance and habitat
                                by the Minerals Management Service or the Fish and Wildlife Service in this                                            alteration of key nesting areas. It is important to prevent disturbance of
                                Opinion becomes available. reinitiation of Section 7, consultation may be                                              nesting colonies that could cause nest desertion and egg losses. Potential
                                required.                                                                                                              sources of impact to the brown pelican from existing, and proposed oil and
                                                                                                                                                       gas activities are from development of onshore facilities.associated
                                Brown Pelican  (Pelocanus occidentalis)                                                                                aircraft and boat vessel traffic. offshore ail and gas related trash and 
                                                                                                                                                       debris. and the possibility of an all spill reaching the coast and
                                The brzwn pelican was originally listed thrcughout its range as endanqered                                             contaminating the pelican and its food source (U.S. Fish and Wildlife
                                an October 13, 1970. The species was delisted in Alabama on February 4.                                                Service 1989b).
                                1985, but is still listed as endangered In Louisiana and Mississippi 
                                (U.S. Fish and Wildlife Service 1989a, 1989b).                                                                         Future onshore oil and gas-related facility construction is expected to be
                                                                                                                                                       minimal in the Central Gulf of Mexico Planning Area from this lease sale.
                                T																							   
                                 hree nesting colonies exist in Louisiana, one on North Island. one on                                                 Impacts to the brown pelican from ingestion. contact, or entanglement of
                                North Grosier Island. and one at the "mud lumps" of the Mississippi River.                                             trash and debris are not anticipated to be significant. The Gulf of Mexico
                                The colony at the mud lumps (Plaquemines pariah) was established in                                                    Outer Continental Shelf Region Office. Minerals Management Service, by
                                No nesting rookeries have been identified in Mississippi (Wiggingtan 1990;                                             letter dated August 30. 1990, recommends to lessees and operators that they
                                Rabat 1990).                                                                                                           require all aircraft used in support of their Outer Continental Shelf oil 
                                                                                                                                                       and gas operations to maintain altitudes of 2,000 feet or more when flying
                                Historically, the brown pelican used the Shell Keys National                                                           over all lands located within national wildlife refuges and national parks
                                Refuge (Iberia Parish). However. it is unknown whether the bird currently                                              and seashores (Pearcy 1990).
                                nests on the refuge (Emmons 1990). Refuge staff at Delta National Wildlife										   
                                Refuge (Plaqueminas Parish) have noted that brown pelicans tend to use the                                             Pelicans may be susceptible to oil spills. Even though the island nesting
                                                                                                                                                       sites in Louisiana might he partially protected from direct impact of an
                                                                                                                                                       offshore oil spill by the seaward portion of the barrier islands, the wide-
  



                                                                            7																			8
 













                               ranging nature of the birds when foraging would amplify the possibility of                                     probability) brow pelican nesting or foraging habitat is low, it is the
                               oil contamination. Their entire body can be coated with oil as rho birds                                       Fish and Wildlife Service's Opinion that leasing. exploration, development
                               dive for fish. However. It is reasonable to assume that adult brown                                            production, and abandonment activities for existing and proposed Central
                               pelicans may in fact avoid feeding in oiled water$ because of the                                              Gulf of Mexico Planning area leases are not likely to jeopardize the
                               difficulty in observing fish beneath the surface. very small amounts of                                        continued existence of the brown pelican. However, if new information not
                               certain crude and refined oils applied to the surface of eggs cause high                                       considered by the Minerals Management Service or the Fish and Wildlife
                               embryonic mortality or morphological abnormalities in a variety of avian                                       Service in this Opinion becomes available regarding the brown pelican,
                               species. If spills occurred during the nesting season of the brown                                             reinitiation of Section 7 consultation may be required.
                               pelican. oil can be transferred to eggs from feathers or feet of adults,									 
                               resulting in reduction in hatching success and hatchling survival                                              Bald Eagle (Haliaeatus leucocephalus)
                               (U.S. Fish and Wildlife Service 1989b).																	  
                                                                                                                                              The bald eagle was initially considered to have two disttinct subspecies
                               According to Oil Spill Risk Estimates. the highest annual conditional                                          when the southern bald eagle was listed as an endangered species in the
                               probability of an oil spill starting in the existing and proposed lease                                        Federal Register of March 11, 1967. The entire species was listed as
                               sale area and contacting the Chandeleur brown pelican nesting and foraging                                     endangered in 43 of the conterminous 48 States and threatened in the
                               habitats within 10 days, is a 27 percent chance. The highest seasonal                                          remaining five States an February 14. 1978.
                               probabilities for spring and summer are less than the highest annual								  
                               probability (Hannon and Lear 1990).                                                                            Historically. the bald eagle was a common nesting species throughout the
                                                                                                                                              coastal plain of the Southeast as well as along major lakes and rivers.
                               The conditional probability of an oil spill greater than or equal to                                           Hence. the breeding range was uninterrupted along the east coast from the
                               1,000 barrels occurring from the proposed sale base case. high case.or                                         Chesapeake Bay to the Florida Keys and north along the west coast of
                               all Central Gulf of Mexico Planning Area oil and gas platform activities                                       Florida to the panhandle. The nesting range also appears to have been
                               is a 8. 13. or 98 percent chance. respectively. The highest combined                                           continuous along the entire Mississippi and other major rivers, through
                               probability of an oil spill greater than or equal to 1,000 barrels                                             Louisiana and into test Texas with a low density along the gulf coast. The
                               occurring and reaching brown pelican nesting or foraging habitats within                                       breeding range has been reduced to the remnant population in South
                               10 days is a 5 percent chance (Hannon and Lear 1990).                                                          Carolina. Louisiana. and test Texas, with apparently secure nesting only in
                                                                                                                                              Florida.
                               The highest annual or seasonal conditional probability spill estimate									    
                               from an offshore pipeline spill of contacting Chandeleur brown pelican                                         The bald eagle actively nests in Louisiana and Mississippi; there is no
                               nesting or foraging habitats within 10 days is a 24 percent chance                                             known, nesting in Alabama. In Alabama, on Son Secour National Wildlife
                               The conditional probability of an oil spill greater than or equal to                                           Refuge. bald eagles are sighted. but none are known to nest. The refuge
                               1,000 barrels occurring from the proposed sale base case, high case. or                                        has started a hacking program to reintroduce the eagle (Fulton 1990). In
                               all Central Gulf of Mexico Planning Area oil and gas pipeline Activities                                       1990, three birds were introduced at the refuge. However, there are no
                               is a 9, 15, or 98 percent chance, respectively. The mean number of spills                                      plans for hacking any eagles on the refuge in 1991 Hicks 1991). All the
                               from pipelines for the above conditions is 0.09, 0.16, and 4.17, spills,                                       bald eagles to be introduced into Alabama in 1991 will be the northern part
                               respectively (Hannon and Lear 1990).                                                                           of the State (Hicks 1991).
																												 
                               It is projected that there may be a total of three and four Shuttle tanker                                     There were 45 active bald eagle nests located in coastal Louisana parishes
                               trips for the proposed sale's base and high case scenarios, respectively.                                      during the 1989 to 1990 winter nesting period. The majority of the nesting
                               The planning and analysis area where the trips would originate is Central                                      sites are west of the Mississippi River to the AtChafalaya Basin with a few
                               coastal area 3 (C-3) which encompasses the most eastern portion of                                             scattered nests east of the Mississippi River. In Mississippi, the only 
                               Louisiana. The highest seasonal (winter) conditional probability for a                                         known active nest near the coast in 1989, was in Harrison County just north
                               spill to reach brown pelican habitats within 10 days from a shuttle tanker                                     of the junction of Biloxi River and Say within visual distance of
                               spill is a 3 percent chance within the C-3 area. The highest annual                                            Interstate 10. no nest was destroyed during one of the 1985 hurricanes;
                               condition probability within the C-3 area is a I percent chance                                                however. a pair of bald eagles have since been observed in the area.
                               (U.S. Minerals Management Service 1990).                                                                       Current nesting success is unknown. An active nest was reported in Hancock
                                                                                                                                              County, Mississippi, near the town of Logtown off Mississippi Sound in
                               Since new onshore facilities construction is anticipated to be    minimal and                                  1988. However. the status of that nest for 1990 is unknown (Bagley 1989;
                               the possibility of an oil spill occurring and contacting (combined                                             Robot 1990).

                                                                                                                                                                                 10
                                                                   9
 
















                                According to the Bald Eagle Recovery Plan. essential habitat is an area of                                   the Exxon Valdez in Prince William Sound in Alaska. The most important
                                concentrated nesting that is looked upon as a nuclear population. The loss                                   adverse impact of an oil spill on bald eagles would probably be on
                                or substantial alteration of a population center would seriously jeopardize                                  reproduction through contamination of eggs from adults carrying oil
                                the long-term survival chances for the species In Louisiana. Wetland                                                breast feathers and feet. Bald eagle nesting in Alaska following the Exxon
                                coastal habitats in Louisiana have been designated as essential habitat                                      Valdez tanker spill had an 85 percent nest failure rate in heavily oiled
                                (U.S. Fish and Wildlife Service 1989c).                                                                      areas and a 50 percent nest failure rate in lightly oiled areas. The main
                                                                                                                                             reason for failure was from direct contamination of the eggs from oiled
                                Eagles are opportunistic feeders, with fish constituting the bulk of their                                 adults. Another factor included disturbance of the breeding adult eagles
                                diet. They will feed an waterfowl and shorebirds, particularly sick or                                    from the helicopter and boat traffic related to the oil spill cleanup. A
                                injured individuals, as well as carrion. Throughout most of the bald                                         year later. decreased breeding rates were noted in the oiled areas compared
                                eagle's range. its population decline has been largely attributed to the                                     to the unoiled areas (Schempf 1990).
                                effect of pesticide ingestion (Which resulted in eggshell thinning) and
                                indiscriminate shooting of both immature and adult birds (U.S. Fish and                                      The conditional probability of an oil spill greater than or equal to
                                Wildlife Service 1989b).                                                                                     1,000 barrels occurring from the proposed sale base case, or all
                                                                                                                                             Central Gulf of Mexico Planning Area oil and gas platform activities is a
                                Potential sources of impact to the eagle from existing and proposed oil and                           	   8, 13, or 98 percent chance. respectively. The combined probability of an
                                gas activities are disturbance to its nests. resulting from development of                            	   oil spill greater than or equal to 1,000 barrels occurring and reaching
                                onshore facilities and aircraft and boat vessel traffic, trash and debris,                                   bald eagle nesting or foraging habitats within 10 days has a high of
                                and the possibility of an oil spill reaching the coast and contaminating                                     I percent chance for the sale base and high case. and a high of 58
                                the eagle and its food source U.S. Fish and Wildlife Service 1989).                                       percent chance for all Central Gulf Planning Area (Hannon and Lear 1990)

                                Future onshore oil and gas-related facility construction is expected to be                                   Annual and seasonal conditional probability spill estimates for a spill
                                minimal in the Central Gulf of Mexico Planning Area from his lease sale.                                    originating from a pipeline starting and contacting bald eagles nesting or
                                Impacts on the bald eagle from ingestion, contact, or entanglement from                                      foraging habitats within 10 days are moderate to high (30 to 98 percent
                                trash and debris is not expected to be significant. The Gulf of Mexico                                      chance). The conditional probability of in oil spill gre
                                Outer Continental Shelf Region Office, Minerals Management Service, by                                      to 1,000  barrels occurring from the proposed sale base case, high case, or
                                letter dated August 30, 1990, recommends to lessees and operators that they                                  all Central Gulf of Mexico Planning Area oil and gas pipeline activities is
                                require all aircraft used in support of their Outer Continental Shelf oil.                                   a 9, 15, or 98 percent chance. respectively. The mean number of spills
                                and gas operations to maintain altitudes of 2,000 feet or more when flying                                    from pipelines for the above conditions is 0.09, 0.16, and 4.17 spills,
                                over all lands located within national wildlife refuges and national parks                                 respectively (Hannon and Lear 1990).
                                and seashores (Pearcy/1900).
                                                                                                                                            It is projected that there may be a total of three and four shuttle tanker
                                According to the Oil Spill Risk Estimates, land segments in Louisiana and                                  trips for the proposed sale's base and high case scenario, respectively
                                Mississippi where the bald eagle nesting occurs are 14, 15, 16, 17, 12, 19,                                The planning and analysis area where the trips would originate is Central
                                20. and 21. The highest annual or seasonal (winter. spring) conditional                                      coastal area 3 (C-3) which encompasses the most eastern portion of
                                probabilities of an oil spill starting in the existing and proposed lease                                   Louisiana. The highest seasonal (spring) conditional probability for a
                                sale area and contacting these land segments within 10 days are 9 percent,                                  spill to reach bald eagle habitats within 10 days from a shuttle tanker
                                15 percent, 36 percent, 27 percent, 12 percent, 66 percent, 3 percent, and                                   spill is a 64 percent chance within the C-3 area. The highest annual
                                26 percent, respectively. This represents a low to moderate threat.                                          condition probability within the C-3 area is a 41 percent chance
                                                                                                                                             (U.S. Minerals Management Service 1990).)
                                it can be expected that bald eagles might be attracted to the area of a
                                spill by dead and dying fish and birds as a food source. and -thereby,                                       Since new onshore facilities construction Is anticipated to be minimal
                                consume oil adhering to prey species. Never the less. evidence from other                                   the possibility of an oil spill occurring and contacting (combined
                                species of birds suggests that adult birds may be able to tolerate the                                       probability) from the proposed lease sale is low, it is the Fish and
                                Ingestion of fairly high concentrations of crude oil. Also, the direct                                       Wildlife Service's Opinion that leasing, exploration, development
                                effect of oil on plumage is perhaps not as significant a factor with bald                                    production, and abandonment activities !or existing and
                                eagles since adults, at least. tend to have minimal contact with the watar                                  Gulf of Mexico Planning Area leases are not likely to jeopardize the
                                from which they are taking pray. However, some direct mortality of adult                                    continued existence of the bald eagle. However, if new information not
                                bald eagles from oiling was observed after the 1983 tanker oil spill from                                   considered by the Minerals Management Service or the Fish and Wildlife
                                                                                                                                             Service in this Opinion becomes available regarding the bald eagle
                                                                                                                                             reinitiation of Section 7 consultation may be required.



                                                                                                                                                                                       12
 














                                  Piping plover (Charadrius melodus)
                                                                                                                                                 40. 7. and 21 percent chance. respectively, of receiving oil within 10 days
                                  The piping plover was federally listed as endangered in the Great Lakes                                        of an oil spill occurring In the existing and proposed lease area (Hannon
                                  watershed and threatened elsewhere in its range on January 10. 1986. This                                      and Lear 1993).
                                  species breeds only in North America in three geographic regions. The
                                  bird's primary winter range is along the Atlantic and gulf coasts from                                         The conditional probability of an oil spill greater than or equal to
                                  North Carolina to Mexico (U.S. Fish and Wildlife Service 1989a. 1989b).                                        1,000 barrels occurring from the proposed sale base case, high case, or
                                                                                                                                                 all Central Gulf of Mexico Planning Area oil and gas platform activites 
                                  Recreational activity. coastal development, and dune stabilization have                                        is a 8, 13 or 98 percent chance, respectively. The highest combined
                                  resulted in loss of appropriate sandy beaches and other littoral habitats.                                     probability of an oil spill greater than or equal to 1,000 barrels
                                  Where breeding does occur. breeding success is curtailed because of human                                      occurring from this lease sale and reaching piping plover wintering
                                  disturbance (foot and vehicular traffic) which destroys nests and young                                        habitats within 10 days is less than a 0.5 percent chance (Hannon and Lear 
                                  (U.S. Fish and Wildlife Service 1988. 1989b).                                                                  1990).

                                  In a 1987 to 1988 survey of piping plovers along the gulf coast (Florida                                       Other impacts may result from pipeline placement and construction, onshore
                                  to Texas ) approximately 323 birds. 7.7 percent of the total breeding                                          facility construction near wintering habitats, and trash and debris.  The
                                  population were found along the coasts of Alabama, Mississippi, and                                           probability of impacts from these disturbances are anticipated to be low
                                  Louisiana. Of the total gulf coast survey, piping plovers were observed                                        due to the anticipated minimal activity or construction as a result of this
                                  most frequently in Alabama. Mississippi, and Louisiana (53 to 60 percent of                              lease sale. The impact on the piping plovar from ingestion, contact, or
                                  the sites had birds).                                                                                          entanglement is not anticipated to be significant.

                                  Sites surveyed in the three States having the highest densities Included                                    Offshore pipeline annual and seasonal conditional probability spill
                                  Chandeleur Islands and Rockefeller Refuge. Louisiana. and Little DauphIn                                     estimates have a high of a 58, 4. and 25 percent chance, respectively, of
                                  Island. Alabama. Along with these sites, Buccaneer State park.                                                 contacting within 10 days piping plover important wintering habitats in
                                  Mississippi; and Isle Dernieres East, Louisiana are considered                                                 Louisiana, Mississippi, and Alabama.  The conditional probability of an oils 
                                  piping plover wintering sites. Other wintering habitats are located at                                        spill greater than or equal to 1,000 barrels occurring from the proposed 
                                  Fort Morgan and Little Dauphin Island - Son Seccur National wildlife Refuge                                sale base case, high case, or all Central Gulf of Mexico Planning Area til
                                  in Alabama;Horn Island, Ship Island, and East Ship Island -Gulf Islands                                      and gas pipeline activities is a 9, 15, or 98 percent chance, respectively.
                                  National Seashore, Hewes Avenue  and Moses Pier- Gulf Port.  Pass Christian                                     The mean number of pills from pipelines for the above conditions is 0.09,                                                    
                                  and American Legion Pier in Mississippi; Fourchon Pass, Elmer's Island.                                         0.16. and 4.17, spills, respectively (Hannon and Lear 1990).                           		   
                                                                        						                                       
                                  Timbalier Island, Harsh Island, East Jetty Beach, and Smith's Bayou in
                                  Louisiana (Nichalls 1389). Critical habitat has not been designated !or                                        It is projected that there may be a total of three and four shuttle tanker
                                  piping plover along the gulf coast.                                                                            trips for the proposed sale's base and high case scenarios, respectively
                                                                                                                                                 
                                                                                                                                                 The planning and analysis area where the trips would originate is Central
                                  The plover usually forages on sandflats adjacent to passes and inflats, on                                               coastal area 3 (C-2) which encompasses the most eastern portion of
                                  mudflats near sandy beaches, on overwash sandy mudflats, and on the                                            Louisiana. The highest seasonal (winter) conditional probability for a 
                                  foreshore of open beaches, plucking invertebrates from the surface layer.                                           spill to reach the piping plover important wintering habitats within
                                  Most feeding occurs during low or falling tides (Nicholls 1989). 								10 days from a shuttle tanker spill is less than an 0.5 percent chance		                                    
                                                                              									            within the C-3 area (U.S. Minerals Management Service 1990).
                                  Impacts to the piping plover from oil spills would be caused by fouling of                                     
                                  wintering habitat. The plover may be among the more vulnerable species                                    Temporary displacement by aircraft traffic say also have an impact on the 
                                  because they forage in intertidal areas. Ingestion of oil could occur                                          piping plover. The Gull of Mexico Outer Continental Shelf Region Office,
                                  during the feeding process.  Some oiling may occur through direct sentact                                       Minerals Management Service, by letter dated August 30, 1990, recommends to
                                  with oiled sediments or waves in the splash zone. Impacts on  piping plover                                          lessees and operators that they require all aircraft used in support of
                                  were documented from a 1979 oil spill in Texas.                                                                their Outer Continental Shelf oil  and gas operations maintain altitudes
                                                                                                                                                   of 2,00 feet or more when flying over all lands located within national
                                                                                                                                                 wildlif refuges and national parks and seashores (Pearcy 1990).
                                                                                                                                                 
                                  According to the Oil Spill Risk Estimates, seasonal conditional probabil-                                                                     
                                  Louisiana, Mississippi. and Alabama (land segments 12,20,30) have a
                                                                                                                                                 New onshore facilities construction is anticipated to be minimal and the
                                                                                                                                                 possibility of an oil spill occurring and contacting (combinrd probability)
                                                                                                                                                 piping plover Louisiana. Mississippi, and Alabama, important wintering


                                                                     13
                                                                                                                                                                                   14























                               habitat is low. Therefore, it is the Fish and Wildlife Service's Opinion                                          habitats of receiving oil within 10 days of an oil spill occuring in the
                               that leasing. exploration. development, production, and abandonment                                               existing and proposed lease area, is a 66 percent chance (Hannon and Lear
                               activities for existing and proposed Central Gulf of Mexico Planning area                                         1990).
                               leases are not likely to Jeopardize the continued existence of the piping
                               plover. However, If new information not considered by the Minerals                                               The conditional probability of an oil spill greater than or equal to
                               Management Service or the Fish and Wildlife Service in this Opinion becomes                                      1,000 barrels occurring from the proposed sale base case, high case, or all
                               available regarding the piping plover, reinitiation of Section 7                                                 Central Gulf of Mexico Planning Area oil and gas platform activities is a
                               consultation may be required.                                                                                    8, 13. or 98 percent chance. respectively.  Tne highest combined
                                                                                                                                                probability of an oil spill greater than or equal. to 1.000 barrels
                               Arctic Pereqrine Falcon (Falco peregrinus; tundrius)                                                             occurring and reaching the peregrine falcon's wintering or migratory
                                                                                                                                                habitats within 10 days is a I percent chance for the proposed and high
                               The Arctic peregrine falcon was listed as an endangered species in the                                           case sale and 58 percent for all Central gulf lease sales (Hannon and Lear
                               Federal Register on October 13, 1970. The bird is a subspecies of the                                            1990).
                               peregrine falcon (Falcon peregrinus). This subspecies breeds in the North
                               American tundra and winters along the gulf coast from Florida west to the                                        Offshore pipeline seasonal conditional probability spill estimates havae a
                               eastern Mexican coast and Bala California, south to mid-Chile and mid-                                           high of a 27 percent chance of contacting the peregrine falcon's wintering
                               Argentina. and possibly on Pacific Islands. Critical habitat has not yet                                         or migratory habitats within 10 days. The conditional probability of an
                               been determined for this subspecies (U.S. Fish and Wildlife Service 1989a,                                       oil spill greater than or equal to 1,000 barrels occurring from the
                               1989b).                                                                                                          proposed sale base case, high case, or all Centrall Gulf of Mexico Planning
                                                                                                                                                Area oil and gas pipeline activities is a 9, 15, or 96 percent chance.
                                Field and laboratory evidence indicates that the decline of pereqrine                                           respectively. The mean number os spills from pipelines for the above                                                                                                              
                               population is generally due to the presence of chlorinated hydrocarbon                                           conditions is 0.09, 0.16, and 4.17 spills, respectively (Hannon and Lear
                               pesticides in the falcon's food supply. This leads to reproductive failure                                       1990).
                               through eggshell thinning and non-viable eggs, as well as increased adult
                               mortality. Other factors which may cause local decreases in reproductive                                         It is projected that there may be a total of three and four shuttle tanker
                               success ire human disturbance and adverse weather conditions during nesting.                                    trips for the proposed sale's base and high ease scenarios
                               (U.S. Fish and Wildlife Services 1979. 1989b).                                                                  The planning and analysis area where the trips would orginate is Central
                                                                                                                                               coastal area 3 (C-3) which encompasses the most eastern portion of
                               While the arctic peregrine migrates scuth through a broad area of Eastern.                                      Louisiana. The highest seasonal winter) conditional probability for a
                               and Middle North America to the gulf coast, it funnels into coastal areas                                       spill to reach the peregrines' wintering or migratory habitats within
                               and concentrates along the beaches and barrier islands. During spring,                                          10 days from a shuttle tanker spill is a 32 percent chance
                               migrating falcons are observed offshore along tile coastal areas of the                                         area (U.S. Minerals Management Service 1990).
                               Central Gulf of Mexico. The falcons are occasionally sighted on Breton
                               island and Son Secour National Wildlife Refuges during the winter. At                                           Potential sources at impact to the Arctic peregrine falcon
                               Delta National Wildlife Refuge, the falcons are frequently observed on the                                      and proposed oil and gas activities are temporary, disturbance of winter
                               refuge during the winter. In 1987, peregrines peaked in late October at						     migratory habitats resulting from development of onshore facilities, and 
                               8 to 12 birds and were present most of the winter. The winter population                                        trash and debris (U.S. Minerals Management Service 1990).                           															                                    
                               has remained stable for the last 3 years, and one or more birds can be seen
                               perching on survey towers or pilings on any given day (U.S. Fish and                                             Future onshore oil- and gas-related facility Construction is expected to be
                               Wildlife Service 1989b. Wigginton 1990; Fulton 1990).                                                            minimal in  the Central Gulf of Mexico Planning Area from this lease sale.
                                                                                                                                                Impacts on the peregrine falcon from ingestion, contact, or entanglement
                               The possible impacts on Arctic peregrines from existing and proposed oil                                	     from trash and debris are not expected to be significant.
                               and gas activities include the contamination at the peregrine's food
                               sources from an oil spill. The Arctic peregrine feeds mostly on a wide                                          Another activity that could have an impact on the peregrine falcon is
                               variety of birds and occasionally on small mammals. Peregrines will kill                                        temporary displacement by aircraft and boat vessel traffic on their
                               ailed birds and in doing so, ingest considerable numbers of feathers wit.                                        wintering grounds or along their migration route. The Gulf of Mexico Cutar
                               their meal.                                                                                                      Continental Shelf Region Office. Minerals management Service by letter
                                                                                                                                                dated August 30, 1990, recommends to lessees and operators that they
                               According to the Oil Spill Risk Estimates, the highest seasonal                                                require all aircraft used in support of their Outer Centinental Shield oil.
                               (winter) probability, of Artic peregrine falcon wintering or migratory





                                                                                                                                                                                      16
 
















                                and gas operations to maintain altitudes of 2,000 feet or more when flying                                          Aerial surveys conducted by National Marine Fisheries Service found
                                over all lands located within national wildlife refuges and national parks                                          surfaced sea turtles (probably loggerheads) offshore of the Chandleur and
                                and seashores (Pearycy 1990).                                                                                       Bruton Islands were 6 to 30 times more abundant than surface sea turtles
                                                                                                                                                    west of the Mississippi River. The Fish and Wildlife Service. National
                                                                                                                                                    Marine Fisheries Service, and Louisiana State University has been 
                                Since new onshore facilities construction is anticipated to be minimal and                                          conducting aerial surveys and ground trathinq efforts on the islands since
                                the possibility of an oil spill occurring from the lease sale and                                                   1988 (Fuller 1988, 1989, 1990).
                                contacting (combined probability) pereqrine falcon wintering or migratory
                                habitats is low, it is the Fish and Wildlife Service's Opinion that                                                 Sea turtle nesting habitat may be impacted by oil spills and human
                                leasing. exploration, development, production. and abandonment activities                                           disturbance resulting from Outer Continental Shelf activities. Disturbance
                                for existing and proposed Central Gulf of Mexico Planning area leases are                                           by development and other human use of beaches is incompatible with
                                not likely to jeopardize the continued existence of the Arctic peregrine                                            successful sea turtle nesting. Artificial lights in the nesting beach
                                falcon. However, If new information not considered by the Minerals                                                  areas reduce nesting activity and disorient hatching randering the young 
                                Management Service or the Fish and Wildlife Service In this Opinion becomes                                         turtles vulnerable to road traffic, or predators, and desiccation (Ogran
                                available regarding the Arctic peregrine falcon. reinitiation of Section 7                                          1990: Possardt 1990).
                                consultation may be required.                                                                                       
                                                                                                                                                    Effects of petroleum on the development and survival of marine turtle
                                Loggerhead Sea Turtle (Caritta caretta)
                                                                                                                                                    embryos are variable. Study results indicate that oil remaining on the 
                                The loggerhead was listed as threatened in the Federal Register on july 28.                                    	    beach approximately 1 year after 3 spill did not cause significant
                                1978 .U.S. Fish and Wildlife Service 1989. 1989).                                                                   mortality in sea turtle eggs; however, fresh crude oil deposited on sand
                                                                                                                                                    above a nest can cause extensive mortality to incubating sea turtle egs
                                The loggerhead sea turtle is found in temperata and subtrcpical waters                                      	   (Fritts and McGehee 1982). Important variables in determining the chance
                                worldwide. United States nesting occurs on suitable Southeastern beaches                                            of damage are the stage of nesting, the amount of weathering the oil has
                                from Virginia to the Chandeleur Islands, Louisiana. The major nesting                                              undergone, and the height of deposition on the beach.  In addition, it has
                                beaches, however. occur alont the east coast of Florida from Brevard to                                            been proposed that olfactory clues are imprinted on the turtle and guide it
                                Broward County. In the Gulf of Mexico, loggerhead nest on various barriars                                         back to the natal beach for nesting when it reaches maturity. Oil on the
                                islands and beaches throughout the Florida Keys and up the Florida west                                            beach could interfere with these chemical guides (Lutz et al., 1985: Ogren
                                coast with scattered nesting occurring throughout the northern Gulf of                                             1990; Possardt 1990).
                                Mexico. No critical habitat has been designated for the Loggerhead in the
                                Gulf of Mexico (U.S. Fish and Wildlife Service 1989, 1989; Possardt                                              Studies have shown that sea turtles do not seem to avoid oil slicks  and may 
						                                                                                                             ingest or become fouled with the oil. The direct effects of oil can be                           
                                                                                                                                                lethal or sublethal involving reduction or alteration of organ functions
                                Major factors which threaten the loggerhead an nesting beaches include the                                      such as salt excretion and respiration (Lutz et al., l985,.
															
                                problem of hatzhlng disorientation arising from artificial lights,                                                
                                destruction and ingredation of nesting habitats from teach armoring and							According to Oil Spill Risk Estimates, the highest annual conditional
                                excessive nest and hatchling predation (U.S. Fish and Wildlife Service                                          probability of an oil spill starting in the sale area and reaching
                                1989. Ogren 1990; Possardt 1990)                                                                                Chandeleur and Breton Islands and Alabama nesting habitats within 10 days 
                                                                                                                                                is a 29 percent and a 16 percent chance, respectively. The highest
                                Loggerhead nesting in the Central Gulf Planning Area begins in Alabama                                          seasonal (summer) conditional probability for the above scenario is a
                                where one nest per mile is usually found on Bon Secour National Wildlife                                        55 and 17 percent chance, respectively (Hannon and Lear 1990). The
                                Refuge in Baldwin County (Fulton 1190). In 1989, 13 nests were counted at                                       moderate conditional probabilities al receiving oil during sea turtle
                                Gulf Shores and Fort Morgan (Eley 1989; Elley and Papadelias 1990). In                                          nesting season on the Chandeleur and Breton islands are a concern/
                                Metals County, Alabama, the sea turtle nests on the western end of Dauphin                                          
                                island and has had a nesting density ranging from a low of : per year to #							The conditional probability of an oil spill greater than or equal to
                                high of 12 per year (Fulton 1990; South and Tucker 1991). Also in 1989,                                         1,000 barrels occurring from the proposed sale base case, high case                                                                              
                                Mississippi (Elay 1989; Eloy and Papadelias 1990). Loggerhead nesting has                                      is a 8, 13, or 98 percent chance, respectively. The hignest combined
                                been recently reported at Biloxi. Mississippi (Gulf Coast Research                                              probability of an oil spill greater than or equal to 1,000 barrels
                                Laboratory 1990: South and Tucker 1991).  It is now thought that the                                              occurring and reaching loggerhead nesting habitats within l0 days is a
                                Chandler Island may support a significant mount of loggerhead nesting.						      4 percent chance (Hannon and Laer 1990)
                                


                                                                                                                                                                                                18



                                                                         17



















                                Construction of pipelines across barrier islands onto coastal teaches could                                         Service's Southeast Region Gulf of Mexico Regional Technical Group
                                impact loggerhead sea turtle nesting by habitat disturbance or elimination.                                         member has nominated and recommended that both these types of studies
                                Minimal pipeline landfalls or onshore pipeline projects are anticipated as                                          conducted or continued. The Fish and Wildlife Service Sea Turtle Recovery
                                a result of the Proposed sale base and high case scenario and future                                                Coordinator and staff of the National Wetlands Research Center have
                                activities.                                                                                                         participated in study formulation and planning regarding the above issues.
                                Offshore pipeline annual and seasonal conditional probability spill                                                 Alabama beach mouse (Paromvscus poioonotus ammobates)
                                estimates have a high of a 33 and 17 percent chance. respectively, of
                                contacting Chandeleur and Breton Islands and Alabama coastal loggerhead                                             Perdido Key beach mouse (Paromvscus polionotus trissyllepsis)
                                nesting habitats within 10 days. The conditional probability of in oil
                                spill greater than or equal to 1,000 barrels occurring from the proposed                                             The Alabama beach mouse and the Perdido Key teach mouse were federally-
                                sale base case, high case. or all Central Gulf of Mexico Planning Area oil                                          listed as endangered on June 6. 1985. The mice are two of five species
                                and gas pipeline activities is a 9, 15, or 98 percent chance, respectively.                                         of the old field mouse (Peromyscus polionotus) that occur on the gulf coast
                                The mean number of spills from pipelines for the above conditions is                                                of Alabama and Florida (U.S. Fish and Wildlife Service 1989a, 1989b).
                                O.09. 0.16. and 4.17 spills. respectively (Hannon and Lear 1990).
                                                                                                                                                    The Alabama beach mouse presently survives an disjunct tracts from Fort
                                It is projected that there may be a total of three and four shuttle tanker                                          Morgan State Park to the Bon Secour National Wildlife Refuge, but has
                                trips for the proposed sale's base and high -ease scenarios. respectively.                                          apparently disappered or is non-functional from most of it
                                Tne planning and analysis area where the trips would originate is central                                            range. including all of Cno Island. Critical habitat for the mouse has
                                coastal axes 3 C-31 which encompasses the most eastern portion of                                                 been designated at Fort Morgan. Ben Secour National Wildlife Refuge, and a
                                Louisiana. 'he highest annual or seasonal (summer)conditional probabiltv                                          portion of the Gulf Shores Unit of the Gulf State Park, in Baldwin County
                                far a spill to reach either the Chandeleur and Breton  Islands or Alabama                                          Alabama (U.S. fish and Wildlife service 1989b). However, the mouse appears
                                coastal loggerhead nesting habitat within 10 days from a shuttle tanker                                            to be absent from this area (Moller 1991).
                                spill is less than a 0.5 percent chance within the C-3 area. U.S. Minerals
                                Management Service 1990; Hannon and Lear 1990).                                                                         The Perdido Key beach mouse is the most endangered of the three subspecies
                                                                                                                                                        Listed by the Fish and Wildlife Service. In 1986, the only known
                                Some sea turtles may not feed during the nesting process. and in these                                                  population of this mouse was at Gulf State Park Alabama. Since then the
                                cases,ingestion of oil and gas activity related trash and deoris should                                                 subspecies has been reintroduced to Gulf's Islands National Seashore on
                                                                                                                                                        Peridido Key by transaction of individuals forom Gulf State Park through a
                                not to be an impact. Also, since nesting and hatching emergence accur at                                          
                                night, disturbance from aircraft or boat vessel traffic should be minimal.                                              cooperative State and Federal effort Holler 1989; 1990, U.S. Fish and 
                                an the beaches.                                                                                                         Wildlife Service 1987,1989b).
                                Although, the chances of oil reaching loggerhead sea turtle nesting beaches                                             Critical habitat for the subspecies has bee designatedd at three different
                                with in 10 days of a summer spill  are moderate to high, the chances of an                                              sites on Peridido Key, on in Alabama and two in Florida. In Alabama,
                                
                                oil spill occurring and contacting combined probability; is low and the                                                 critical habitat is located in Gulf State Park, Baldwin County, in Florida.
                                number of nests which could be harmed is low. Therefore. it is the Fish                                                 critical habitat is located in the Peridido Key State Preserve and in the
                                and wildlife Service's Opinion that leasing. exploration. development,                                    		  Peridido Key Unit f the Gulf Islands Mational Seashore , Escambia County	
                                production. and abandonment oil and gas activities for existing and                                                 (U.S. Fish and Wildlife Service 1987, 1989b).
                                proposed Central Gulf at Mexico Planning Area leases are not likely to
                                jeopardize the continued existence of the loggerhead sea turtle. However,                                           Loss of habitat is considered to be the primary factor for both subspecies
                                if now information not considered by the Minerals Management Service or 'he                                        decline. Also, the loss at habitat has resulted -a fragmented populations
                                Fish and Wildlife Service in this opinion becomes available regarding the                                          of the beach mice. Tropical storms are the greatest current hazard to
                                loggerhead sea turtle, reinitation of Section 7 consultation may be                                                further loss Of the subspecies. Thai-- habitat is requested to the primary
                                required.                                                                                                           and secondary sand dunes and scrub dunes along the gulf. The beach mice
                                                                                                                                                    dig burrows mainly on the lee side back side; of the primary dunes and in
                                Additional study is needed regarding the actual sea turtle nesting that                                             other secondary and interior dunes where the vegetation provides suitable
                                occurs an the Chandeleur Islands. Also, information is still needed                                                 cover .  The  mice also use ghost crab Oocypoodda guadmatus brroows. The
                                regarding chemical and physical empact to sea turtles from oil dispersants                                          Perdido Key and Alabama teach mice are nocturnal omniveres.
                                and/or oil as well as sea turtle behavior in regard to oil spill                                                    that  the teach mice feed primarily an the seeds of beach grass
                                avoidance or ingestion of weathered oil products. The Fish and Wildlife                                            Amarum and P. rapens, and sea oates (Unida paniculata and on insects and


                                                             19
                                                                                                                                                                                             20
 





















                                small invertebrates. inland forms feed primarily on seeds and
                                invertebrates ( mainly insects) (Holler 1-990. 1991; U.S. Fish and Wildlife                                    Offshore pipeline annual and seasonal conditional probably
                                Service 1987, 1989b).                                                                                          estimates have a high of a 28 percent chance of contact in
                                                                                                                                               habitats within 10 days. The conditional probability of
                                Although the primary  habitat of the beach mice subspecies is on the lee                                       greater than or equal to 1,000 barrels occurring from the
                                side of the dunes and their inferred food source. sea oats and beach grass,                                    base case. high case. or all Central Gulf of Mexico Plann
                                are located above the high tide line, there is a potential for impacts !ram                                    gas pipeline activities is a 9. 15, or 98 percent chance,
                                an oil spill. The National Park Service describes the following occurrence                                     The mean number of spills from pipelines for the above 
                                during a small oil spill on Horn Island, Mississippi, in September 1989.                                       0.09. 0.16. and 4.17 spills. respectively (Hannon and Lea.

                                      -Several days after landfall of the Horn Island spill. strong surf                                       It is projected that there may be a total of three and 
                                      action and winds combined to remobilize and distribute significant                                       trips for the proposed sale's base and high case scenario
                                      amounts of oil from the beach face up into the adjacent primary                                          The planning and analysis area where the trips would orig
                                      dunes. The spray generated by the wind and surf action was                                               coastal area 3 (C-3) which encompasses the most eastern 
                                      sufficiently oily to completely coat most of the dune vegetation,                                        Louisiana. The highest annual or seasonal conditional are
                                      and resulted in leaf browning which persisted until the next growing                                     spill from a shuttle tanker within the C-3 area to reach
                                      season" (Zimmerman 1990).                                                                               within 10 days is less than an 0.5 percent chance (U.S. H
                                                                                                                                               Service 1990).
                                Given the relatively narrow width of the beaches at Gulf State Park, an Oil
                                spill occurring during an episode of high winds and seas (a relatively                                          Since new onshore facilities construction is anticipated
                                common occurrence) could result in significant contamination of the primary                                     the Possibility Of an oil spill occurring and contacting
                                dune habitat.                                                                                                   probability  Alabama beach mouse or Perdido Key beach mic
                                                                                                                                               it is the Fish and Wildlife Service's Opinion that leasn
                                Other related. existing. and proposed Oil and gas activities which could                                       development, production, and abandonment activities for 
                                have an impact on the beach mice include -onshore pipeline construction and                                    proposed Central Gulf of Mexico Planning Area leases are
                                Placement, onshore facility construction. associated aircraft and :oat                                         jeopardize the contued existence of the Alabama beach 
                                vessel traffic, and offshore related trash and debris. Pipeline                                                Perdido Key beach acuse or destroy or adversely modify 
                                construction and placement as well as Onshore facilites should be                                            habitat, However, should my onshore pipelines or facilities
                                accomplished outside of the dune habitat witihin the beach mouse ranges         and                            activities requiring any action by the Minerals Managemen
                                their critical habitat. Aircraft and boat vessel traffic should have                                           prosposed in either it the beach mice's crtical habitat,
                                minimal impact on the beach mice due to the mice s nocturnal behavior. It                                      consultation will be required.
                                is unknown whether the beach mice nest marine trash and debris mistaking
                                it far food. Although ingestion could affect the mice by interterence with                                     in addition. if new information not considered by the Minerals Management
                                the digestive process or produce a fatal response. Accumulations Of trash                                      Service or the  Fish and Wildlife Service in this Opinion becomes available
                                and debris do not appear to be a severe proclam in beach -mice habitats.                                       regarding the Alabama beach mouse or the Perdido Key beach mouse
                                                                                                                                               reinitiation of Section 7 consulration may be required.
                                According to the Oil Spill Risk Estimates, the highest annual conditional
                                probability of an oil spill starting in the existing and proposed lease                                        Biological Opinion
                                areas and reaching beach mice habitat (land segments 2-2 and 2-1) within
                                10 days. is an IS percent chance. The highest seasonal conditional                                                is the Fish and Wildlife Service's Opinion that the existing and
                                probability for the same scenario is a 21 percent chance (Hannon and Lear                                      proposed Outer Continental Shelf oil and gas leasing. exploration
                                                                                                                                               development. production, and abandonment activities in the area of the
                                                                                                                                               Central Gulf of Mexico Planning Area under the leasing and regulatory
                                The conditional probability Of an oil spill greater than Or equal to                                           authorities Of the Minerals Management Service. are not likely
                                1,000 barrels occurring from the proposed sale base case. high case,over all                                jeopardise te continued existence of listed species and under the Fish and
                                central Gulf of Mexico Planning Area oil and gas platform activities         is a                           Wildlife Service's jurisdiction or destroy or adversely a
                                8, L3. or 98 percent chance. respectively.     The hignest combined                                            critical habitat.
                                probability of an oil spill greater than or eqUal to 1,000 barrels
                                occurring and reaching Alabama beach mice or Perdido Key beach mice habitat                                    Also. formal consultation must be reinitiated If new info
                                within 10 days Is a 1 percent chance ;Fannon and Lear 1990.                                                     impacts an listed species or their habitat from Minerals



                                                                    21
                                                                                                                                                                                     22
 























                                 actions that were not considered in this Opinion. if the proposed project                                                   clay, and silt, with frequent incursions of organic nepheloid layers.
                                 is subsequently modified, or it a new species is listed or critical habitat                                                 almost the opposite of conditions in the eastern gull. (Barkuloo 1988)
                                 is designated which may be affected by the existing and proposed actions.
                                                                                                                                                             The Gulf of Mexico sturgeon would be most vulnerable to oils spills during
                                 Incidental Take                                                                                                             the winter marine migrations. Since the sturgeon is a benthic feeder,
                                                                                                                                                             ingestion of contaminated sediments, organisms, or vegetation could occur
                                 In meeting the provisions for incidental take in Section 7(b)(4) of the                                                     once spilled oil has settled to the seafloor. The ability to sense and
                                 Endangered Species Act. we have reviewed the Opinion and all available                                                      avoid oiled areas by sturgeon is unknown.
                                 information relevant to oil and gas activities. Based on the review,
                                 incidental take is not anticipated and, thus. not authorized for listed                                                      The adult sturgeon does little or no feeding In freshwater
                                 species. If the taking of a listed species under Fish and Wildlife Service                                                  its growth and reproductive potential depend entirely on the resources
                                 jurisdiction should occur. the Fish and Wildlife Service's Regional office                                                 accumulated by feeding during winter migrations.  Consumption of
                                 in Atlanta should be notified immediately at (404) 331-3580 to determine                                                     contaminated food sources could lead to general body deterioration, lower
                                 whether reinitiation of consultation is necessary.                                                                          reproductive potential, and lower viability of offspring.  Information is
                                                                                                                                                             also lacking on whether sturgeon aggregate during the winter migrations.
                                 Proposed Species                                                                                                            Data suggests, however, that adults rend to enter and leave the freshwater
                                                                                                                                                             system within a very narrow time period (Barkuloo 1988).
                                 Gulf of Mexico sturgeon (Acipenser oxyrhycchus desotoi)
                                                                                                                                                             The conditional probability of an oil spill' greater than or equal to
                                 The secretary of the Interior approved listing of the Gulf of Mexico                                                    1,000 barrels occurring from the proposed sale base case, high case, or all
                                 sturgeon as threatened in April l990. The Proposed Rule was published in                                                      Central Gulf of Mexico Planning Area oil, and gas platform activities is a 
                                 the Federal Register May 2, 1990                                                                                           8. 13. or 98 percent chance. respectively.

                                 The Gulf of Mexico sturgeon is a subspecies if the Atlantic sturgeon and                                                    The Gulf of Mexico sturgeon would be most affected by offshore oil and gas
                                  is a known to occur in most major rivers from the Mississippi River to the                                             related structure removal (abandonment) during the winter migrations.  The
                                 Suwannee River and in marine waters of the Central and Eastern Gulf of                                                 sturgeon is a benthic feeder and could be attracted to offshore structures.
                                 Mexico south to Florida Bay.  Sturgeon in Alabama. Mississippi, and                                                    However, it has not been documented how far offshore Gulf of Mexico
                                 Louisiana can be described as rare; recent specimans have been obtained                                                sturgeon migrate in winter. Also, the ability of thesturgeon to avoid an 
                                 from Lake Ponchartrain, Pearl River, Pascagcula River, and the Motile                                                  area where an offshore structure is being removed is unknown.
                                 River.  No catches of Gulf of Mexico sturgeon been recorded in Federal       
                                 waters in the Gulf of Mexico. There has been no effort to the surgeon                                                  Analysis of known information on the Gulf of Mexico sturgeon indicates that
                                 during their Offshore migration. Critical habitat is act proposed for the                                          leasing, exploration, development, production, and abandonment of oil and
                                 Gulf of Mexico sturgeon Parkuloo 1988.                                                                        gas activities from the existing and proposed lease sale is not likely to
                                                                                                                                               jeopardize the continued existence of the Gulf of Mexico sturgeon.  This
                                 The sturgeon virtually disappeared throughout much of its range at the turn 						constitutes an informal conference on the species for the existing and
                                 of the century. The declines were attributed to damming of rivers and                                             proposed activities. Should the Gulf of Mexico sturgeon be final listed or
                                 other forms of habitat destruction, over-exploitation, and deterioraton of                                             new information be developed before this action, consultation may need to
                                 water quality (Barkuloo 1988).                                                                                              be reinitiated.

                                                                                                                                                           Incidental take is not anticipated. and thus, not authorized
                                 The Gulf of Mexico sturgeon spends a major portion of its life in rivers or								species. If the taking of this species should occur, the Fish and wildlife	
																										Service's Regional Office In Atlanta should be notified immediately at
                                 bays. and makes winter marine migrations as they grow older. No studies                                                     (404) 321-3580 to determine whether reinitation of consultation is
                                 have delineated the Gulf of Mexico sturgeon's marine habitats.  Limited                                                    necessary.
                                 stomach analyses from Suwannee and Apalachicola River sturgeon indicate                                                            
                                 that sand bottom, hard bottom, and seagrass communities are probably very                                                       
                                 important marine habitats for a. o. desotoi. Our conclusion on habitat
                                 preference/utilication is circumstantial; however. it true, this could                                                     There is a major gap in information on the Gulf of Mexico sturgeon's  
                                 explain why the Eastern Gulf of Mexico has historically had larger                                                         migratory habits.  The offshore marine habitats have not been located due
                                 populations than the central gulf, and why their range does not include the                                                to researcher's inability to locate or trick these fish in salt water.  A
                                 western gulf, Senthic marine habitats in the western gulf are mostly mud,


                                                                                                                                                                                                    24


                                                                              23
 





















                                  study of this fish using acoustic tracking devices has been ranked                                                     Impacts to the snowy plover from oil spills would be caused by fouling of
                                  moderately high by the Gulf of Mexico Regional Technical Working Group for                                             foraging habitat.  Ingestion of oil could occur during the feeding process.
                                  inclusion into Minerals Management Service's Environmental Studies Program                                             Some oiling may occur through direct contact with oiled sediments or waves
                                  regarding Outer Continental Shelf oil and gas activities.                                                              in the splash zone.

                                  Candidate Species                                                                                                      According to the Oil Spill Risk Estimates, the highest annual probability
                                                                                                                                                         of an oil spill starting in the existing and proposed lease areas and
                                  Southeastern Snowy Plover (Charadrius a1exandrinus tenuirostris)                                                       reaching snowy plover habitat (land segments 21, 22, and 23) within
                                                                                                                                                         10 days, Is 23 percent. The highest seasonal (winter or summer)
                                  The Fish and Wildlife Service considers the Southeastern snowy plover to be                                            conditional probability for the same scenario is 23 percent (Hannon and
                                  a Category 2 candidate for listing. Category 2 comprises taxa for which                                                Lear 1990).
                                  information now in possession of the Fish and Wildlife Service indicates
                                  that proposing to list as endangered or threatened is possibly appropriate.                                            The conditional probability of an oil spill greater than or
                                  but for which conclusive data on biological vulnerability and threat are                                               1,000 barrels occurring from the proposed sale base case, high case, or all
                                  not currently available to support proposed rules. However, a recent                                                   Central Gulf of Mexico Planning Area oil and gas platform activites is a
                                  report by the Florida Game and Fresh Water Fish commission, partially                                                  8, 13, or 98 percent, respectively. The highest combined probability of an
                                  funded by the Fish and Wildlife Service.  Indicates that the species could							   oil spill greater than or equal to 1,000 barrels occurring and reaching
                                  be proposed for listing in the foreseeable future.                                                                     snowy plover habitat within 10 days is a 3 percent (Hannon and Lear 1990).                 
                                                                                                                                                  
                                  The southeastern snowy plover is one of two subspecies of the snowy plover                                             Probably the greatest impact resulting from proposed oil and gas activities
                                  Charadrius Alexandrinus. The Southeastern snowy plover breeds  along the                                               would be from onshore pipeline placement and construction, onshore facility
                                  gulf coast from Mexico to south Florida and on larger islands in the                                                   construction, and disturbance by aircraft. All these activities could
                                  Caribbean.  In Alabama, Mississippi. and Louisiana, snowy plovers occur								   cause reduced or abandonment of nesting sites and temporay displacement
                                  Only along sand beaches on the gulf coast.  The snowy plove requires both                                              from wintering habitats.                                            
                                  dry and tidal sand flats for foraging. The birds feed an small crustaceans                                                                              
                                  mollusks, worms, and insects that they glean from beaches  and sand flats
                                  (Gore 1990).																		   Offshore pipeline annual and seasonal spring conditional probability
                                                                                              								               spill estimates have a high of a 56 percent chance of contacting snowny
                                  Throughout its range in the Southeast, the snowy plover's requirements for                                             plover habitats with in 10 days.  The conditional probability of an oil  
                                  the birds prefer for nesting are also highly desirable recreational.                                                   spill greatern than or equal to 1,000 barrels occuring from the proposed , 
                                  resources for human populations.  Unfortunately, snowy plovers do not                                                  sale base case, or all Central Gulf of Mexico Planning Area oil                                                             
                                  tolerate much disturbamce near their nests, and typically avoid or abandon							   and gas pipeline activities is 9, 15, or 98 percent, respectively.  The 
                                  Beaches that are fequented by people.  This loss of nesting habitat has								   Mean number of spills from pipelines for the above conditions is 0.09,
                                   led to an apparent decline in the number of snowy ploves breeding in the								   0.16, and 4.17 spills, respectively Hannon and Lear 1990.

                                   Southeast.  Other known causes of decline include storms, vehicles, nd                                                Although there is 3 moderately high chance that snowy plover habitats would
                                  predators (Gore 1990).																   be contacted with in 10 days of an pipeline oil spill, the probability of
                                                                                                                                                         impacts from these disturbances are anticipated to be law due to the
                                    During a breeding population survey in 1989, approximately 30 pairs of the                                          anticipated minimal activity or construction as a result of this lease                                                      
                                  bird were estimated in Alabama and Mississippi (Chase and Gore 1989: Gore                                             sale. Impacts on the snowy plover from ingestion, contact,or entanglement
                                                                                                                                                         from trash and debris is not expected to be significant.
                                                                               													
                                  1990). In Alabama the plover has regularly nested at Fort Morgan, Baldwin
                                  County and Dauphin Island, and Sand land, Mobile County in the past                                                Temporary displacement by aircraft traffic may also have an impact on the
                                  Chase and Gore 1989).  The plover occurs an Horn, Petit Bois, and East							     snowy plover. The Gulf of Mexico Outer Continental Shelf Region Office.
                                  and West Ship islands off Mississippi.  In 1990 to 1991.                                                           Minerals Management Service, by letter dated August 30, 1990
                                  30 breeding pairs were observed on the gulf-facing side of the islands.                                            lessees and operators that they require all aircraft used in support of
                                  Another 60 birds were counted as wintering on the island in 1990 to 1991.                                          their Outer Continental Shelf oil and gas operations to maintain altitudes
                                  Wintering birds use habitat at the tips of the islands (Chase and Gore				                       of 2,000 feet or more when flying over all lands located within national
                                  1989; Simons 1991).  In a 1990 survey conducted in conjuction with a sea                                           wildlife refuges and national parks and seashores   (Pearcy 19990).
                                  turtle nesting/stranding survey on Breton National ildlife Reguge no snowy        
                                  plovers were observed (Fuller 1990)                    
                                  


                                                                                                                                                                                                26

                                                                         25
 




















                                 It is projected that there may be a total of three and four shuttle tanker                                       be included for each Plan of Exploration. Development, Production
                                 trips for the proposed sale's base and high case scenarios. respectively.                                        pipeline applications in the following lease blocks:
                                 The planning and analysis area where the trips would originate is Central
                                 coastal area 3 (C-3) which encompasses the most eastern portion of                                                     -Mobile Area blocks 766, 809-816, 819-824, 826-830, 853-874,898-
                                 Louisiana. The highest annual or seasonal conditional probability for a                                                   918, 942-962, 987-1006
                                 spill from a shuttle tanker within the C-3 area to reach snowy plover                                                  -South Pass Area blocks 28, 32-34. 36-38, 43-58, 59-69,70-73, 78
                                 habitat within 10 days is less than an 0.5 percent chance (U.S. Minerals                                               -South Pass South Addition Area blocks 74-96
                                 Management Service 1990).                                                                                              -Mississippi Canyon Area blocks 21. 22, 109 110, 147-153, 191-197,
                                                                                                                                                           234-241, 265, 266. 278-285, 309-313, 321-329, 353-373, 397-417
                                 The Fish and Wildlife Service has no specific advisory guidance to provide                                                441-461, 485-505
                                 for the southeastern snowy plover at this time.                                                                        -West Delta Area blocks 17-24, 28-36, 39-50, 57-69, 69-80, 85-134
                                                                                                                                                        -West Cameron Area blocks 19-30, 34-48, 53-88, 90-118, 128-156,
                                 Conservation Recommendations                                                                                              161-191, 195-227, 287-315
                                                                                                                                                        -Sabine Pass Area blocks 6-15
                                 The Minerals Management Service requires that lessees prepare and submit                                               -Ship Shoal Area blocks 9-14, 25-38, 49-63, 68-100
                                 oil spill contingency plans with all permit applications in accordance with
                                 30 CFR 250.33, 30 CFR 250.34, and 30 CFR 250-42.  The plans must contain                                         Pipeline applications only lease blocks:
                                 assurances that a full response capability exists for commitment in the                                                -Main Pass Area all blocks
                                 event of an oil spill. Such a commitment includes specification of                                                     -Grand Isle Area all blocks
                                 appropriate equipment and materials, their availability and deployment                                                 -South Pelto Area all blocks
                                 time, and provisions for varying degrees of response effort, depending                                                 -South Timbalier Area blocks 20-10, 123-120
                                 the severnity Of the spill. A Letter to Lessees (LTL) was issued by the                                                -Eugene Island Area blocks 19-144
                                 Minerals Management Serice Gulf If Mexico Cuter Continental Shelf Regional
                                 office on February 1, 1989, and September 5, 1989, providing guidelines for                                      The response plans should include cut not are limited to, identification of
                                 preparation of the oil spill contingency plans.                                                                  the identified species habitat, oil spill trajectory modeling to ascertain
                                                                                                                                                  the time for oil to reach the Habitats, implementation 
                                 The historical record for Gulf of Mexico oil and gas offshore operations                                         of the nesting habitats in case of an oil spill. Cleanup methods, and State
                                 including exploration. development, production, and abandonment activities                                      and Federal resource manager contacts.
                                 from rigs, platforms, and pipleines excluding oil transported by shuttle                              
                                 tanker or barge to snore-base-facilities) indicates five oil spills of                                          In accordance with 5O CFR 27.34 the unauthorized operation
                                 10,000 barrels or more have occurred from 1969 to 1989. An estimated                                             altitudes resulting in harassment of wildlife above refuges is prohibited.
                                 279,000 barrels have been spilled. Spills occurring in the early years                                          Refuge boundaries are designated on Federal Aviation Administration
                                 Were closer to the coast, whereas current activities are concentrated                                            aeronautical charts.
                                 further offshore. thereby, increasing distances to share.
                                                                                                                                                  To further minimize impacts to endangered and threatened
                                 In order to reduce impacts on threatened and endangered species, we                                              recommend the Minerals Management Service continue to recommend that
                                 recommend that the Minerals Management Service continue to require the                                           lessees' aircraft operators to adhere to the above altitude restrictions
                                 petroleum industrys to prepare adequate oil spill contingency plans for all                                      over national wildlife refuges and parks (including national seashores
                                 activities.  This should include the strategic placement of appropriate                                          In particular, Minerals Management Service should determine
                                 spill cleanup equipment. personnel training in cleanup techniques. and                                           significant pelican nesting and specifically recommend the
                                 demonstration of response capabilities and implementation. Further, the                                          aircraft operators maintain the minimum altitude restrict
                                 Fish and Wildlife Service recommends the Minerals Management Service adopt                                       areas during the pelican's nesting season.
                                 the following conservation recommendations to minimize any potential
                                 impacts on the nesting and foraging habitats of the bald eagle, the nesing                                     As cited in the Opinion, the Minerals Management Service
                                 activity of loggerhead sea turtles, winter habitats of the piping plover.                                        special advisory (NTL 96-11) and promulgated regulations (20 CFR 250.40) to
                                 and the winter migrationr habitat of the Arctic peregrine falcon.                                                 assure lessees do not create conditions that will pose an unreasonable risk
                                                                                                                                                  to public health, life, property, aquatic life, wildlife, recreation.
                                      Specific oil spill contingency response plans for protecting the above3                                     navigation, commercial fishing, or other uses of the ocean during offshore
                                 identified species' activities, except the peregrine falcon for pipelines.                                        oil and gas operations U.S. Minerals Management Service 1990.


                                                                         27                                                                                                                29
 



















                                                                                                                                                                                          References

                                   To further minimize impacts to endangered and threatened species, we                                               Auburn University.    1984.   Vertebrate Wildlife of Alabama.  Alabama
                                   recommend the Minerals Management Service continue to enforce,their                                                       Agricultural Experiment Station. 44 pp.
                                   regulations regarding marine debris disposal from offshore oil and gas
                                   operations.                                                                                                        Bagley. F. 1989. Personal communication on Louisiana,  Mississippi, and
                                                                                                                                                             Alabama populations of brown pelican, bald eagles, and sea turtles
                                                                                                                                                             U.S. Fish and Wildlife Service Field Office, Jackson, Mississippi.

                                                                                                                                                      Barkuloo, J.M. 1988. Report on the conservation status of the Gulf of
                                                                                                                                                             Mexico sturgeon (Acipenser oxythychus desototi).  U.S. Fish and 
                                                                                                                                                             Wildlife Service. Panama City. Florida. 33 pp.

                                                                                                                                                      Chase. C.A. and J.A. Gore. 1989. Snowy plover breeding
                                                                                                                                                             to 1989. Survey and monitoring. Final performanc,
                                                                                                                                                             Game and Fresh Water Fish Commission. Panama City
                                                                                                                                                             Prepared for the U.S. Fish and Wildlife Service.
                                                                                                                                                             Florida.

                                                                                                                                                      Eley,  T.J. 1989. Letter regarding Survey of sea turtle nesting in
                                                                                                                                                             Escamcia. Santa Rosa. and Okaloosa Counties. Florida,
                                                                                                                                                             areas in Alabama and Mississippi. University of West Virginia
                                                                                                                                                             Assistant Professor Of Geography and Resource Management
                                                                                                                                                             Pensacola, Florida. November

                                                                                                                                                      Eley. T.J. and C.A. Papadelias. 1990. An assessment of nesting sea turtles
                                                                                                                                                             on the Gulf Islands National Seashore and adjacent beaches.
                                                                                                                                                             University of West Florida. Occasional Papers in Coastal Studies.
                                                                                                                                                             25 pp.

                                                                                                                                                      Emmons. S.  1990.  Personal communication regarding Federally listed
                                                                                                                                                             endangered species occurrence on Shell Keys National Wildlife
                                                                                                                                                             Refuge. U.S. Fish and Wildlife Service. November 13.

                                                                                                                                                      Fritts. T.H. and H.A. McGehee.  1982. Effects of petroleum on the
                                                                                                                                                             development and survival of marine turtle embryos.  U.S. Fish and
                                                                                                                                                             Wildlife Service Office of Biological Services. Washington, D.C.
                                                                                                                                                             FWS-0BS-82/37. 41, pp.

                                                                                                                                                      Fuller. D.A. 1988. The occurrence of sea turtles on the Chandeleur an
                                                                                                                                                             Breton Islands, Louisiana. Louisiana State University
                                                                                                                                                             Rouge, Louisiana.  LSU-CFI-88-14.  October. 13 pp.  Prepared for the
                                                                                                                                                             U.S. Fish and Wildlife Service. Jackson, Mississippi.

                                                                                                                                                      Fuller. D.A. 1989. Sea turtles strandings on the Chande
                                                                                                                                                             Islands, Louisiana. State University.  Baton Rouge.
                                                                                                                                                             Louisiana. LSU-CFI-89-06.  October. 14 pp. Prepared for the
                                                                                                                                                             U.S. Fish and Wildlife Service. Jackson. Mississippi






                                                                               29


                                                                                                                                                                                           30
 





















                                       Fuller, D.A.     1990.   1990 surveys for nesting and stranded sea turtles on                                             Mount. R.H.  (editor).   1986.    Vertebrate animals of Alabama in need of
                                               the Chandeleur and Breton Islands. Louisiana.  Louisiana State                                                    special attention.  Alabama Department of Conservation and Natural
                                               University. Baton Rouge. Louisiana.  LSU-CFI-90-03. September.                                                             Resources. Game and Fish Division. April.  124 pp.
                                               14 pp. Prepared for the U.S. Fish and Wildlife Service. Jackson,
                                               Mississippi.                                                                                                      Mueller. A.  1990. Personal communication regarding Arc
                                                                                                                                                                         falcon and species behavior during an oil spill.
                                       Fulton, J.  1990.   Personal communication regarding endangered and                                                               Wildlife Service. Assistant Field Office Supervisor.  Clear Lake,
                                               threatened Species occurring on Bon Secour National Wildlife Refuge.                                                      Texas.
                                               U.S. Fish and Wildlife Service.
                                                                                                                                                                 Murphy. T.M., F.M. Bagley, W. Dubuc, D. Mager. S.A. Nesbitt, W.B.
                                       Gore. J. 1990. Personal communication regarding snowy plovers in the                                                              Robertson, Jr., and B. Sandus. 1989. Southeastern States Bald
                                               Southeast. Florida Game and Fresh Water Fish Commission.  Panama                                                eagle recovery plan.  41 pp. with Appendices A to J.
                                               City. Florida.
                                                                                                                                                                 Nicholls. J.L.     1989.   Distribution and other ecological
                                       Gulf Coast Research Laboratory. 1990. Turtle hatching makes history.                                                              plovers (Charadrius melodus) wintering along the Atlantic and Gulf
                                               Marine Briefs. pg. 5. September-October.                                                                                  coasts. Masters Thesis. Auburn University, Alabama.  150pp.

                                       Hannon, L.J., and S.M. Lear.  1990. Draft Oil-Spill Risk Estimates; Gulf                                             Ogren. L.    1990. Personal communication regarding sea turtles and
                                               of Mexico (Proposed Lease Sales 131/135/137) Cuter Continental                                                            potential impacts from offshore oil and gas activities.  National
                                               Shelf. U.S. Minerals Management Service.  CCS Statistical Report.                                                          Marine Fisheries Service Laboratory. Panama City, Florida.
                                               MMS  90-0011. 410 pp.                                                                                                   
                                       																				Possardt, E. 1990. Personal communication regarding sea turtles and
                                       Hicks.  S.  1391. Personal communication regarding baid eagle hacking program                                                     potential impacts from offshore oil and gas activ1ties.  U.S.  Fish
                                               on Bon Secour National Wildlife Refuge. Assistant Refuge Manager.                                                         and Wildlife Service. Southeastern Region sea turtle coordinator.
                                               U.S. Fish and Wildlife Service.                                                                                           Jacksonville, Florida.
                                       Holler. N.R. 1989. Letter to Jay Troxel. U.S. Fish and Wildlife Service.                                            Pearcy. J.R. 1990. Letter to lessees and operators of oil and gas
                                               Panama City Field Office Florida, regarding a U.S. Navy proposed                                                         operations in the Outer Continental Shelf Gulf of Mexico Planning
                                               Perdido Key beach mouse monitoring program at the Gulf Islands                                                           Area regarding aircraft altitudes above national wildlife refuges
                                               National Seashore. Alabama Cooperative Fish and Alabama Cooperative Fish and Wildlife Research                           and national parks and seashores. August 30. 2 pp
                                               Unit. Auburn University, Alabama.         3 PP.                                                             Rabot. T.    1990.  Personal communication regarding federally listed 
                                       Holler, N. R.   1990. Letter to Lorna Patrick, U.S.  Fish and Wildlife                                                             endangered species in Louisiana and Mississippi.  U.S.  Fish and
                                               Service, Panama City Field Office. Florida regarding draft                                                                 Wiildlife Service.  Lafayette Field Office, Louisiana.
                                               Biological. Opinion for Sale 137, Eastern Gulf of Mexico. Alabama                                               Cooperative Fish and Wildlife Research Unit. Auburn University,                                                  Schempt. P.  1990. Personal communication regarding bald eagle nesting in
                                               Alabama.   1 p.                                                                                                           Alaska following the 1989 Exxon Valdez oil spill in Prince William
                                                                                                                                                                         Gound. U.S. Fish and Wildlife Service. Office of Migratory Birds.
                                       Holler, N.R. 1991. Letter to Lorna Patrick. U.S. Fish and Wildlife                                                                Juneau, Alaska (907) 586-7243.
                                               Service, Panama City Field Office, Florida. regarding draft
                                               Biological Opinion for Sale 139, Central Gulf of Mexico.  Alabama                                     Simons. T. 1991. Personal communication regarding snowy plovers on Gulf
                                               Cooperative Fish and Wildlife Research Unit. Auburn University,                                                          Islands National Seashore. National Park Service.  Ocean Springs,
                                               Alabama.   I p.                                                                                                           Mississippi.

                                                                                                                                                                                                                                   
                                       Lutz,  P.L. and D.K. Odell, L.M. Llewelyn, E.S. Van Vleet, R. Witham.  G.D.                                  South, C. and S. Tucker. 1991. personal communication regarding sea turtle
                                               Bossart, S.L. Vargo. J.S. Kepley.  1985. Draft final report.                                                        nesting in the State of Alabama. U.S. Fish and Wildlife Service.
                                               Effects of oil and marine turtles. Volumes  1,2 and 3. Florida                                                      Daphne Field Office. Alabama.
                                               Institute of Oceanography.                                                                                       U.S. Fish and Wildlife Service.  1971, 1988, and 1989.  Annual          
                                                                                                                                                                    narrative for Lacassine National Wildlife Refuge. 
                                                                                                                                                                         


                                                                                 31



                                                                                                                                                                                                              32
 






                                                                                                                               B-39







                                             Figure 1: Central Gulf of Mexico Outer Continental Shelf
                                                                       Planning Area


                   U.S. Fish and Wildlife Service.  1979.  Eastern peregrine falcon recovery                                                                      
                        plan.  Eastern peregrine falcon recovery team.  May.  147 pp.

                   U.S. Fish and Wildlife Service.  1987.  Recovery plan for the
                        Choctawhatchee, Perdido Key, and Alabama beach mice.  U.S. Fish and
                        Wildlife Service.  Atlanta, Georgia.  45 pp.

                   U.S. Fish and Wildlife Service.  1988.  Atlantic coast piping plover
                        recovery plan.  U. S. Fish and Wildlife Service.  Newton Corner,
                        Massachusetts.  77 pp.

                   U.S. Fish and Wildlife Service.  1989a.  Endangered and threatened wildlife
                        and plants.  50 CFR 17.11 & 17.12  34 pp.

                   U.S. Fish and Wildlife Service.  Southeast Region.  1989b.  Individual
                        species accounts for Federally listed threatened and endangered
                        species.

                   U.S. Fish and Wildlife Service.  Southeast Region.  1989c.  Southeastern
                        status bald eagle recovery plan.  Atlanta, Georgia.  41 pp. with
                        appendices A - J. 

                   U.S. Minerals Management Service.  1990.  Final environmental impact
                        statement, Gulf of Mexico Salas 131, 135, and 137.  Gulf of Mexico
                        Region.  New Orleans, Louisiana.

                   Wigginton, J.  1990.  Memorandum regarding federally listed endangered
                        species occurrences on Southeast Louisiana Refuges.  U.S. Fish and
                        Wildlife Service.  December 10.  7 pp.

                   Zimmerman, C. S. 1990.  Letter dated May 16 regarding review of trade
                        U.S. Fish and Wildlife Biological Opinion for Sale 137 Eastern Gulf
                        of Mexico Planning Area.  National Park Service, Gulf Breeze,
                        Florida.

                                                       33




                                                                         


















                       U.S. Fish and Wildlife Service

                             Biological Opinion

                          Western Gulf of Mexico

                                  Sale 141


















                                                                                                                                                                                                                       Attacnment 1
                                                United Stum Deputinent of the Intnior                                                                       United States Department of the Interior at rod
                                                           Fish and W&M Semoe                                                                                                rISH AND WILDLIFE SERVICE                               seems
                                                                                                                                                                                POST OFFICE BOX 1306
                                                        DIVISION OF ECOLOGICAL SERVICES                                                                                       ALBUQUERQUE.N.M. 87103
                                                         17629
                                                              EL CAMINO REAL. SUITE 211
                                                                     K TEXAS 77058
                                                             .4 r"s-T-0                                                                           In R ply Refer To:                 JUN 19 1987
                                                                                                                                                    Re;ion 2/FWE
                                                                 January 4, 1991



                               KEM0RI1WDnK          A,-                                                                                                                                         Consultation No.: 2-13-87-F-28
                               To:            Associate Director for Offshore Minerals Management,                                                1111MIA111"
                                              Minerals Management Service, Washington, D.C.                                                       To:        Director, Mlnerals Management Service, Washington, DC
                               From:          Acting Field Supervisor, U.S. Fish & Wildlife Service,                                              From:      Regional Director, U.S. Fish and Wildlife Service, Region 2.
                                              Ecological Services, Houston, TX                                                                              Albuquerque, NH
                               Subj ect:      Formal Consultation for Proposed Outer Continental                                                  Subject:  Endangered Species Act: Biological Opinion for Outer Continental
                                              Shelf Oil and Gas Lease Sale (Unnumbered) for the                                                              Shelf Oil and Gas Lease, Sale No. 115, Western Gulf of Mexico.
                                              Western Gulf of Mexico under the Endangered Species
                                              Act  , Section 7
                                                                                                                                                  By memorandum dated January 12,        1987, the Minerals Management Service
                                                                                                                                                  requested the reinitiation of formal consultation with the U.S. Fish and
                                                                                                                                                  Wildlife Service under Section 7 of the Endangered Species Act to consider
                               Your let or dated October 4, 1990, requesting formal consultation                                                  .11 operat one pertaining to Outer Continental Shelf oil and gas lease No.
                               for the troposed lease sale, pointed out that the June 19, 1987,                                                   115.  This biological opinion covers the western Gulf of Mexico planning
                                         p                                                                                                        area, which borders Texas.       This consultation was extended to June 15,
                               biological opinion for the Gulf of Mexico Western Planning Area                                                    1987, by mutual agreement.
                               (WPA) was up-to-date and effective. We concur with this finding
                               and you may consider the biological opinion and conservation                                                       This biological opinion updates our October' 25, 1982, opinion for the pro-
                               recommendations as current.                                                                                        grammatic eastern. central, and western Gulf of Mexico oil and gas lease
                                                                                                                                                  also.    The previous opinion addressed only the leasing and exploration
                               If you have any questions, please contact Fred Werner, the Gulf WPA                                                %pects of oil and gas operations whereas this will, In addition, evaluate
                               Coordinator, here at our Clear Lake Field Office (FTS: 526-6700).                                                  development and production. Platform removal will be included in National
                                                                                                                                                  Marine Fisheries Service biological opinions.

                                                                                                                                                  Background Information

                                                                                                                                                  Since this is a reinitiation of a previous consultation on essentially the
                                                                                                                                                  same region, comments will generally reference the previous biological
                               cc                                                                                                                 opinion of October 25, 1982, and the statements in that opinion stand
                               Regional Director, Gulf of Mexico OCS, Minerals Management Service,                                                unless now information    and now activities consulted an necessitate addi-
                                                                                                                                                    n    C
                                 Attn: Patrick Mangan, New Orleans, LA                                                                            ti:lal,,, consent.   This Opinion in also based on updated oil spill risk
                           --b5irector, FWS, Washington, D.C.                 (FWS/DHC/BFA)                                                       an ye , discus ons      with exports an the various threatened and endangered
                               Regional Director, FINS, Attn:          HC (Paul Fore), Albuquerque, NN                                            pecies, field observations of species distribution and their reaction to
                                                                                                                                                  :il spillso and selected literature.

                                                                                                                                                  There are two areas of concern when considering potential effects of oil
                                                                                                                                                  and gas activities on endangered or threatened species.             First in the
                                                                                                                                                  chance of an oil spill impacting listed species.         for this evaluation we
                                                                                                         AW
                                                                                                        MW











































                                                                                                                                                  used the accepted risk analysis for the spills from the western Gulf of
                                                                                                                                                  Mexico =der the Met Likely Find Scenario for sale 115, and for spills
                                                                                                                                                  from the total aggregate of sources including past, proposed, and future





















                                                                    -2-                                                                                                         -3-

                              sal:us for the entire Gulf, as well as transportation of imported oil                                       Pelicans may be susceptible to oil spills.        As brown pelicans d1ve for
                              thr  gh the Culf.    Spill projections presented are the percent probability                                fish, their entire body can be coated with oil.        This my contribute to
                              that one or more spills of at least 1,000 barrels will strike a given                                       direct mortality (King at al. 1979) or could result in a secondary impact
                              target within 30 days of the Initiation of the @pill during the expected                                    in reduced hatchability of eggs that may become oiled by a contaminated
                              35-year production life of the proposed lease area.                                                         adult bird.   Even though the Island nesting site in Texas might be par-
                                                                                                                                          tially protected by seaward barrier islands from the direct impact of an
                              The second major source of potential impact is the development of onshore                                   oil spill in the open Gulf, the vide-ranging nature of the birds when
                              facilities that Include pipelines, separator facilities, offices, heli-                                     foraging would amplify the possibility of oil contamination.          The most
                              copter and fixod-wing aircraft facilities. boat docks, refineries, gas                                      damaging effect of oil contamination on brown pelicans would likely be on
                              processing plants, and other support bases.      There is an extensive history                              reproduction.   Due to the bird's feeding habits, it is reasonable to &same
                              of Intensive oil and gas activity in the Gulf of Mexico, and numerous                                       that adult brow pelicans might in fact avoid feeding in oiled waters
                              onshore facilities have been established throughout the region.         The de-                             because of the difficulty in observing fish beneath the surface.       But very
                              velopment of now onshore facilities is difficult to predict.        This evalu-                             small mounts of certain crude and refined oil& applied to the surface of
                              ation is, therefore, based largely on our past experiences with onshore                                     eggs cause high embryonic mortality or morphological abnormalities in a
                              facility development.                                                                                       variety of avian species (Albert 1982, King and Lefever 1979, Lewis and
                                                                                                                                          Malocki 1984, White et al. 1979).        If spills occur during the nesting
                              The following endangered species occur in Texas coastal counties, but are                                   season of the brown pelican, oil can be transferred to eggs from feathers
                              not likely to be affected by the proposed action:       Aplomado falcon (Falco                              or feet of adults, resulting in reduced hatching rates.     Under a worst cane
                              famoralis), Attvater's greater proirie-chicken (Tympanuchus cupido att-                                     oil spill scanario, a full year's reproduction could be lost and an unknown
                              wateri), r*d-cockaded woodpecker (Picoides borealis), black lace cactus                                     number of adults killed.   The impact of oil spills on the recoverability of
                              (Echinoceraus roichenbachii var. alberti), slander-rush pea (Roffmanneeggia                                 brown pelicans in the Texas coastal region could be substantial.      The prob-
                              tonalla) ' and Texas bitterweed (H   Too"'     texana).   The red wolf (Canis                               ability of Nuec*s County receiving spilled oil from the proposed sale is 2
                              Tu-fu.7-n. longer occurs In Tax...    The Nath-arback. sea turtle (Dermochelvs                              percent and 35 percent from the aggregate of sources.
                              coriaces) occurs in Texas waters, but not on shores covered by this
                              opinion.     The National marine Fisheries Service biological opinion will                                  Whooping Crane (Grus americans)
                              address any potential waterborne impacts to sea turtles and marine @als.
                                                                                                                                          The wintering range of the entire reproducing wild population of the whoop-
                              Brown Pelican (Palecanus occidentalis)                                                                      Ing crane exists along the Texas coast, including a portion of the critical
                                                                                                                                          habitat (Aransas, Calhoun, and Matagorda Counties).       In recent years, as
                              The nesting habitat of these colonial birds Is small coastal islands in                                     their population has increased, there has been a tendency for aomm uhoopers
                              salt and brackish waters.    Nests are constructed from available vegetation.                               to defend smaller winter territories than in the past, which results In
                              The major food of the pelican to fish, including menhaden, mullet, set-                                     more whooping cranes per unit of area in the traditional use areas.
                              dines, and pinfish.     The brow pelican catch*$ fish by plunge-diving in                                   Others, though, are wintering away from these areas.         These birds faed
                              coastal waters.     Brown pelicans are rarely found away 'from saltwater and                                largely on crabs and clans while wading in tidal flats, shallow bays and
                              typically do not venture more than 20 miles out to son.       Extensive use of                              channels.  Oiled waters in these habitats could pose a considerable threat
                              pesticides, which are ultimately ingested by the brown pelican, is the                                      If a spill occurred between November and late April, when the cranes are on
                              primary cause of the current population decline.                                                            their wintering grounds. As with brown pelican nesting sites, this winter-
                              There Is only on* remaining brown pelican nesting site In Texas - Pelican                                   Ing habitat of whooping cranes is protected to some extent from oil spills
                                                                                                                                          In the open Gulf by barrier islands, but the lose of even a relatively
                              Island In Nuaces County. However, this colony is prospering with 300 nest-                                  small portion of a population, estimated to consist of approximately 110
                              Ing pairs In 1986. Current recovery planning aims at transplanting some of                                  individuals, could have a drastic impact an the continued existence of the
                              these nestlings to other Texas coastal islands, to establish additional                                     species. The probability of whooping crane foraging habitat being impacted
                              brooding locations, but the specific transplant islands have not been iden-                                 by one or more substantial oil spills is 2 percent for the proposed lease
                              tifled. The brown pelican Is extremely susceptible to disturbance, includ-                                  sale. This Increases to 49 percent for the total aggregate of oil sources.
                              ing low flying aircraft, and habitat alteration of key nesting areas.        The
                              disturbance of nesting colonies can cause nest desertion and OSS losses.                                    Like the brown pelican, the whooping crane Is subject to disturbance from
                                                                                                                                          low flying aircraft, particularly helicopters.






















                                                                      -4-


                              Bald Eagle (Haliaeatus loucocephalus)
                              Bald angles are opportunistic feeders, with fish constituting the bulk of                                      hummocks, or the ground.     While the Arctic peregrine falcon aigrates south
                              their diet.    They will also feed on waterfowl and shorebirds, particularly                                   through a broad area of eastern and middle North America to the gulf coast,
                              sick or injured individuals, as veil as carrion.         Throughout most of the                                It funnels into coastal areas and concentrate@ &long the beaches and bar-
                              bald eagle's range, its population decline has been largely attributed to                                      rier islands, especially on Padre Island, Texas.       The total North American
                              the effect of pesticide ingestion, which resulted in eggshell thinning, and                                    population of Arctic peregrine falcons is escimsted to be 20.000.            Each
                              indiscriminate shooting of both Immature and adult birds.                                                      year 2,000 - 5,000 of these birds migrate through Padre Island, with an
                                                                                                                                             average stay of 10 - 12 days.     An additional 100 - 200 birds winter on the
                              In 1986, there vote 10 active bald eagle nests in four Texas coastal                                           Texas coast.
                              counties: Victoria (3). Calhoun (1). Matagorda (2), and Brazoria (4).            in
                              additton, there is a larger population of wintering bald eagles distributed                                    The possible impacts on Arctic peregrino falcons from the oil and gas
                              throughout the upper Texas coast, with concentrations at reservoirs and                                        activities include the contamination of food sources and disruption of
                              major waterfowl wintering sizes.                                                                               habitat along their migration rout*.

                              The two potential sources of impact to the eagle from the oil and gas                                          Jagu&rundi (Felis yaxou&roundi cacomitli)
                              activities are disturbance to its nests, resulting from development of
                              onshore facilities, and the possibility of an oil spill reaching the coast                                     The jaguarundi was listed as an endangered species on June 14, 1976.         This
                              and contaminating the food source of the eagle.         It can be expected that                                =all nocturnal cat is very elusive and difficult to study.           About twice
                              bald eagles might be attracted to the area of a spill by dead and dying                                        the size of a domestic cat, it has two color phase@, one grayish, the other
                              fish and birds as a food source and, thereby, consume oil adhering to prey                                     reddish.   Males are about 3.5 feet long, of which the tail is more than
                              species.   Nevertheless, evidence from other species of birds suggests that                                    half (Davis 1974).    It Is thought to occur in the lower Lio Grande valley
                              adult birds may be able to tolerate the ingestion of fairly high concentra-                                    with sporadic unconfirmed sighting$ as far north as Brazoris County.         Loss
                              tions of crude oil.      However, oil on plumage could adversely affect repro-                                 of its prime habitac, native brushland., is the main reason for its
                              duction through contamination     of eggs from adults carrying oil on breast                                   decline.
                              feathers and feet.
                                                                                                                                             The development of onshore oil and gas service bases has caused the clear-
                              Arctic Peregrine Falcon (Falco    peregrinus tundrius)                                                         ing of native brush.      Future similar developments would further reduce
                                                                                                                                                ilable habitat.
                              This subspecies breeds in the     North American tundra and winters along the
                              gulf coast from Florida, vast     to the eastern Mexican coast and Baja Cali-                                  :::lot (Polio pardalis)
                              fornia, south to aid-Chile and mid-Argentina, and possibly on Pacific
                              Islands.                                                                                                       The ocelot me listed as an endangered species on July 21, 1982.              This
                                                                                                                                             spotted cat is also relatively unstudied.      Adult malet may be an much as 3
                              Field end laboratory evidence indicates that the decline of paregrins popu-                                    feet. 10 inches long; females up to 3 feet, and weigh 20 - 35 pounds (Davis
                              lotions is generally due to the prosenct of chlorinated hydrocarbon pasci-                                     1974).
                              c1des in the falcon's food supply (Evans 1982). This leads to reproductive
                              failure through eggshell thinning and mon-viable eggs, as well as increased                                    In the United States, the ocelot is confined to native brushlands in the
                              adult mortality.    Other factors which may cause local decreases in repro-                                    lower Lin Grande valley, and a small area of southeast Arizona.           Predator
                              ductive success are human disturbance and adverse weather conditions during                                    control activities and brush clearing have greatly reduced the population.
                              nesting.                                                                                                       Brush clearing associated with onshore oil and gas developments in south
                                                                                                                                             Texas would contribute to its decline and inhibit recovery efforts.
                              The Arctic peregrine falcon foods mostly on a wide variety of birds. ?are-
                              Stints will kill oiled birds and in doing so, ingest considerable numbers                                      Eskimo Curlew (Numenius borealis)
                              of feathers with their meal. The impact of this ingested oil is unknown.
                                                                                                                                             The Eskimo curlew was listed as an endangered species an March 11, 1967.
                              tosential habitat for the Arctic paregrins falcon includes preferred broad-                                    This formerly abundant shorebird previously nested in the Arctic tundra and
                              ing areas near rivers. lakes. or the sea in the Arccic tundra, here                                            wintered in southern South America.      The population decreased drastically
                              nesting &Its& Include cliffs, dikes, cutbanks. and occasionally boulders,                                      in the 1880's. apparently from spring market hunting (Gallup at al. 1986).







                                                                                                                                                                                                                                              tZ
                                                                                                                                                                                                                                              t





















                                                                                                                                                                                      -7-

                                1ince.1945, ther:,h&ve been eleven sighting* of one or more Eskimo curlews                                      Incubating as& turtle eggs.   important variables In determining the chance
                                .n th  Texas  co   t.   The most recent sighting on May 7, 1981 , was of 23                                     of damage are the stage of nesting, the mount of weathering the oil has
                                birds on Atkinson Island in Galveston Bay.        Habitats used have Included                                   undergone, and the height of deposition on the beach (Fritts and McGehee
                                sand flats, Brassy marshes, and grated pasture.       The most recant sighting                                  1982). In addition, it has been proposed that the release of some chemical
                                anywhere "a of 6 birds on Kendall Island. Northwest Territories, Canada                                         substance guides the turtle on Its return from the sea to the natal beach
                                on July 10, 1985.                                                                                               for nesting (Lutz at al. 1986).      Oil an the beach could interfere with
                                                                                                                                                the@* chemical guides, as well as physically impede nesting attempts.        More
                                This species Is nearly extinct, so the loss of even one Individual would be                                     definitiv:t Information Is needed to assess the impacts of oiling on sea
                                very serious.   The Texas coast was, and possibly Is, a regular stopping                                        turtle no ing beaches.
                                point on its spring migration (fall migration was primarily over the
                                Atlantic Ocean off the eastern United States).        Eskimo curl&.$ could be                                   Kemp's Ridley Sea Turtle (Lovidochelys kompli)
                                killed by an oil @pill striking the Texas coast.     The probability of an oil
                                @pill striking Galveston County Is 3 percent from the proposed sale and 89                                      Except for sporadic nests on Padre Island, Texas, and at scattered loca-
                                percent from the aggregate sources.                                                                             tions on the Mexican Gulf coast, the entire population of this species
                                                                                                                                                n :tso on approximately 17 miles of beach at Rancho Nuevo, Tamaulipas ,
                                Piping Plover (Charedrius solodus)                                                                              M: ic (H Pkine and Richardson 1984).     Since 1978, the U.S. Fish and Wild-
                                                                                                                                                life Service has been Involved In an international cooperative project
                                The piping plover is listed as endangered in the Great Lakes watershed and                                      designed to establish nesting sites in the United States.        Eggs are col-
                                as threatened in the remainder of Its range, including Texas.      This species                                 lectod in Mexico, transported to Padre Island National Seashore, and placed
                                has three primary breading areas: the aid-contitient prairies, the Great                                        in artificial nests.  After hatchlings are released free theme nests into
                                Lakes, and the Atlantic coast from North Carolina to the maritime provin-                                       the water, they are recaptured and raised in -head start" facilities until
                                coo.  It winters an the Atlantic ocean and Gulf of Mexico coasts and on                                         they are mature enough to be released into the Gulf.     It is hoped that this
                                Caribbean islands.    Preliminary information indicates that Texas is the                                       procedure will result in turtles that are Imprinted an Padre Island as a
                                most important wintering area.      The estimated world population is 4,000                                     nesting site, and that they will return there when sexually mature.          The
                                birds with at least 400 wintering In Texas (Haig and Oring 1985).        Through-                               impacts of a fresh oil @pill would probably be significant if the oil hit
                                out its range, the piping plover uses urvegetated open sand areas where it                                      the boaches during the nesting season.     The probability of a 1,000 barrel
                                foods mainly on surface and infaunal invertebrates.       In Texas, the exten-                                  or more oil #pill striking some part of Padre Island within 30 days of its
                                siva sand flats of the Laguna Madre and sand flats associated with barrier                                      Inception is 3 percent.  When the aggregate of oil sources are considered,
                                island passes and river mouths arm the most important habitats.             These                               this probability climbs to 51 percent.     Such probability figures are high
                                areas are subject to heavy disturbance from recreational use, and are also                                      enough to warrant concern.
                                susceptible to damage from oil spills. Although shorebirds have'& tendency
                                to avoid oiled beaches, this does not totally eliminate direct oiling of                                        The likelihood of oil spilled from a wall in the U.S. western Gulf of
                                birds. In addition, an oil spill forces birds to use less desirable feed-                                       Mexico striking the Rancho Nuevo beach is small, approximately I percent.
                                ing areas until the cleanup is completed.      There Is also some evidence of                                   If tanker oil transported in U.S. waters is considered, the probability
                                long-tars reduction of Infounal populations following an oil spill.          This                               increases to at least 16 percent.     Oil production in Mexican waters in-
                                could lower the habitat quality of prime wintering mites for an undater-                                        creases the probability by an unknown but significant mount.          The IXTOC
                                stood period.                                                                                                   oil spill In 1979 oiled the Rancho Nuevo beaches.

                                Because the piping plover is so very restricted to coastal sand habitats,                                       Green Sea Turtle (Cholonis 2ydan)
                                it is on* of the species that could be most severely damaged by an oil
                                spill.                                                                                                          The green me& turtle Is listed as threatened in all of its range except the
                                                                                                                                                ;rate waters of Florida and the Pacific coast of Mexico, where it is ondan-
                                Sea Turtles                                                                                                     arad. This turtle has a broad, heart-shaped @hall and a small head, and
                                                                                                                                                Is found throughout the world In tropical and semi-tropical waters.           In
                                Studies on the effect$ of petroleum on the development and survival of                                          eastern North America. It Is found free the coasts of Massachusetts to
                                marine turtle embryos are inconclusive.    The results of these studies indi-                                   Mexico. The known U.S. nesting is limited to southern Florida beaches.        It
                                cate that oil remaining on the beach approximately one year after a spill                                       also nests in small numbers at @tattered locations on the Mexican gulf
                                did net cause significant mortality in "a turtle eggs; however, fresh                                           coast. Oil spill probabilities for the Mexican gulf coast are as described
                                crude oil deposited an send above a nest can cause extensive mortality to                                       for the Rancho Nuevo beaches.




















                                                                                                                                                                                      -9-

                               Loggerhead Sea Turtle (C&ratt& caretta)                                                                        CONSERVATION RECO?0(ENDkTIONS
                               The threatened loggerhead sea turtle nesting to scattered along most of the
                               Gulf of Mexico.    The oil spill probabilities for the Mexican gulf coast are                                  In order to reduce impacts on threatened and endangered species, we racom-
                               &a described for the Rancho Nuevo beaches.                                                                     mend that the Minerals Management Service continue to require the patrols=
                                                                                                                                              indu atry to prepare oil spill contingency plans for all activities.           This
                               Bswksbill Sea Turtle (Eretuoch*Iya imbricate)                                                                  should include the strategic placement of spill cleanup equipment, training
                                                                                                                                              personnel in both cleanup techniques and providing them with locations of
                               The distribution of the bawksbill In the Atlantic Ocean      extends from south-                               sensitive threatened and endangered species habitats. To avoid disturbance
                               ern Brazil to Massachusetts.        Nesting occurs on scatcared islands and                                    of brown pelican nesting activities, we recommend all aircraft, both heli-
                               shores generally between 25 degrees north and south latitude, including                                        copter and fixed wing$ be required to avoid flying lower than 1,000 feet
                               beaches in the states of Campeche and Yucatan, Mexico.                                                         above ground level over Pelican Island or within a 2,000 foot perimeter
                                                                                                                                              around this island in Corpus Christi Bay.       In addition, to avoid disturbing
                               Hawksbills frequent rocky areas, reefs, shallow coastal areas, lagoons of                                      wintering whooping crane& between October 15 and April 15, all aircraft
                               oceanic islands, and narrow creeks and passes, and are generally found in                                      shouldcfly,above 1,000 feet over Aransas National Wildlife Refuge; whooping
                               water less than 20 asters deep.        Hatchlings are often found floating in                                  crane   ric cal habitat In Aransas, Calhoun, and Refugio Counties; Blackjack
                               masses of sea plants.    The hsvksbill feeds on the bottom and forages close                                   Peninsula; the northern 1/2 of San Jose island; and the southern two-thirds
                               to shores and reefs.    It is omnivorous although It prefers invertebrates.                                    of Matagorda Island.
                               Precise population estimates are not available.        Although the former dis-                                To avoid or reduce oil spill damages to sea turtle nesting activities, we
                               tribution me probably equal to the present, population numbers have                                            recommend that the Minerals Management Service continue to require the
                               declined considerably.     Many nesting beaches have been abandoned due to                                     patrol*= Industry to prepare contingency plans to remove eggs from beaches
                               natural disasters (such as hurricanes and erosion), alteration of habitat,                                     that are   imminently expected to receive spilled oil.        The eggs should be
                               or commercial utilization by "a.                                                                               incubated and the young        turtles  released in an uncont sminstod        area.
                                                                                                                                              Research  should be conducted on the measures needed to rehabilitate oil
                               The probability of oil spilled from a wall in the U.S. western Gulf of                                         impacted turtles.
                               Mexico striking the Campeche and Yucatan nesting beaches to less than one
                               percent.   Tanker oil transport and Mexican offshore oil and gas operations                                    There remains for consideration the cumulative Offset@ Of State and private
                               increase the probability by an unknown amount.                                                                 actions in the western Gulf of Mexico region that are reasonably certain to
                                                                                                                                              OC cur prior to completion of the Federal action which is the subject of
                               BIOLOGICAL OPINION                                                                                             this consulcation.     Since no specific information on such actions has been
                                                                                                                                              provided to us, wa reserve the right to make a supplementary comment on the
                               it is my biological opinion that the proposed activities are not likely to                                     potential effects of these projects (emulative effects).
                               jeopardize the continued existence of any species addressed in this biolog-
                               Ical opinion.   it to also not likely Chat the proposed action would result                                    formal consultation must be rainitiated If new information reveal$ impacts
                               In the destruction or adverse modification of critical habitat of the                                          an listed species of their habitats from this federal project that ware no        t
                               whoopLr4 crane.                                                                                                considered in this opinion, If the proposed project is subsequently modi-
                                                                                                                                              fied, or If a now species is listed or critical habitat to designated which
                               INCIDENTAL TAKE                                                                                                may be affected by the proposed actions.

                               no lncidimt&l take of any species 16 anticipated to result from the pro-
                               posed action.    In the event that an incident Occurs as part of and during
                               the course of the activities covered by this opinion that could result in
                               the Incidental take of listed species, the activities causing the incident
                               must be terminated and consultation must be rainitistod so the degree and
                               amount of anticipated Incidental take can be assessed and reasonable and
                               prudent measures can be developed to reduce the levels of such take.





                                                                 -10-


                                                             SELECTED REFERENCES


                               Albers, P.M. 1982.     Effects of oil on avian reproduction:  a review and
                                    discussion.  Pages 78-96.  In:  The effects of oil on birds a multi-
                                    disipline symposium.  The Wetlands Institute, Stone Harbor, NJ.

                               Davis, W.B. 1974.  The mammals of Texas.  Texas Parks and Wildlife Depart-
                                    ment, Austin. Bulletin No. 41. 294 pp.

                               Evans, D.L. 1982.  Status reports on twelve raptors.  U.S. Fish and Wild-
                                    life Service, Washington, D.C.  Special Scientific Report - Wildlife
                                    No. 238. 68 pp.

                               Fritts, T.B. and M.A. McGehee. 1982.  Effects of petroleum on the develop-
                                    ment and survival of marine turtle embryos.  U.S. Fish and Wildlife
                                    Service, Office of Biological Services, Washington, D.C.  FWS/OBS-
                                    82/37. 41 pp.

                               Gallup, J.B., T.W. Barry, and E.B. Iversan. 1986.  Eskimo curlew a vanish-
                                    ing species?  Saskatchewan Natural History Society Special Publication
                                    No. 17. 160 pp.

                               Haig, S.R. and L.W. Oring. 1985.  Distribution and status of the piping
                                    plover throughout the annual cycle.  J. Field Ornithol.  56:334-345.

                               Hopkins, S.R. and Richardson, J.I. (eds.). 1984.  Draft recovery plan for
                                    marine turtles.  The Marine Turtle Recovery Team. 282 pp.

                               King, K.A. and C.A. Lefever.  1979.  Effects of oil transferred from incuba-
                                    ting gulls to their eggs.  Marine Pollution Bulletin 10:319-321.

                               King, K.A., S. Macko, P.L. Parker, and E. Payne. 1979.  Resuspension of
                                    oil:  probable cause of brown pelican fatality.  Bull. Environm.
                                    Contam. Toxicol. 23:800-805.

                               Lewis, S.I. and  R.A. Malocki. 1984. Effects of egg oiling on Larid produc-
                                    tivity and population dynamics. Auk 101:584-592.

                               Lutz, P.L., D.E. Odell, L.M. Ehrhart, I.S. Van Vlost, R. Witham, and G.D.
                                    Bossart. 1986.  Study of the effects of oil on marine turtles.
                                    Minerals Management Service, Vienna, VA.  OCS Study MMS 86-0070.     3
                                    Vols.

                               White, D.H., K.A. King, and N.C. Coon. 1979.  Effects of No. 2 fuel oil on
                                    hatchability of marine and estuarine bird eggs.  Bull. Environm.
                                    Contam. Toxicol. 21:7-10.
 











                                                                       Appendix C



                                                      Resource Estimates Guidelines











                                                                                                                                     C-3

                              ESTIMATES OF QUANTITIES OF UNDISCOVERED RESOURCES

                1. Resource Assessment Methodology
                     Estimates of potential quantities of undiscovered oil and gas are vital to essential long-range national planning.
                The Federal Government's offshore oil and gas leasing program depends heavily on projections of the potential
                amounts of undiscovered hydrocarbon resources on the Outer Continental Shelf (OCS) and on an estimate of those
                resources that may be technologically and economically recoverable. The pace of discovery and development of
                these resources affects national security, the economic health of a large sector of the economy, the balance of trade,
                and many other important national issues.
                     The Minerals Management Service (MMS) develops estimates of the undiscovered oil and gas resource base
                and economically recoverable undiscovered hydrocarbons in support of the OCS leasing program. These estimates
                are used in a number of public and internal documents related to leasing, such as sale-specific Environmental
                Impact Statements (EIS), Action Update Memorandums (AUM), the Biennial Report to Congress (Section 606,
                OCS Lands Act), formulation of the 5-year leasing program, and technical publications.
                     The EIS's for specific lease sales and events such as the development of a 5-year leasing program use the
                estimates as a basis for analyzing potential environmental impacts of a proposed activity, e.g., oil spin risk analysis,
                sale alternatives and deferral options, or any other requirement for which the potential resources in specific areas
                may serve as the basis for evaluating potential actions. In the AUM, estimates of the amounts and locations of
                potential resources are used to assist the Secretary of the Interior in balancing the economic benefits of
                development against the environmental consequences resulting from the leasing of offshore areas for petroleum
                exploration and development. Estimates provided in the Biennial Report to Congress may be used by the legislative
                branch and others for national strategic and economic planning purposes.
                     Estimating the economically recoverable amounts of oil and gas remaining to be discovered on the OCS is a
                difficult task because of the uncertainties inherent in the process. The actual existence of hydrocarbon
                accumulations is not known with certainty prior to exploratory drilling. The only information concerning the
                existence of a potential producing field is derived from inferences, extrapolations, and subjective judgments.
                Geophysical data provide clues as to the existence and location of possible traps (prospects) and their general
                dimensions, but geologic data on the quality of any potential reservoir rocks or source materials are usually absent.
                Generally, until drilling operations commence, no data will be available on the nature and distribution of included
                hydrocarbons or indeed whether hydrocarbons are present at all. Obviously, an exact prediction of resource
                quantities under such circumstances is impossible because the uncertainties in the input data set translate directly
                to uncertainties in the estimates.
                     Wo main types of undiscovered resource estimates are commonly used, each responding to different needs.
                Conditional, undiscovered resource estimates represent the amount of resources anticipated if a certain condition
                exists, the condition being that recoverable quantities of oil and/or gas are present in the area of study. In other
                words, if oil and/or gas are found to exist in an area, the conditional estimates represent the amount of hydrocarbons
                determined to be ultimately recoverable. These estimates are used, for instance, to assess the potential
                environmental impacts in an area if leasing, exploration, development, and production were to occur; the condition
                that hydrocarbons exist must be assumed, otherwise impacts would not be a concern.
                     However, if the economic value of a resource is being considered, conditional estimates are not the appropriate
                measure. In these cases, such as the economic analysis prepared for salc-specific AUM's, the resource estimates
                must incorporate the probability (or risk, which is often extremely high in frontier areas) that recoverable
                hydrocarbons may not be present in the entire area. The conditional estimates are modified by consideration of
                the probability that recoverable resources do not exist (that is, factoring in the risk) and are then said to be fisked
                resource estimates.
                     Because of the uncertainty of geologic and engineering variables associated with hydrocarbon traps, resource
                estimates are usually presented as a range or distribution of values; reporting just one value lends a false sense of
                precision to the estimate. If a single estimate is required, the mean value of the distribution of possible values is
                the single best indicator of central tendency, since it reflects both the probability and magnitude of the estimates.
                The mean, also known as the expected value, is the arithmetic average of all values in the distribution. It is not the
                "most likely' estimate. The most likely estimate is a probability-weighted average called the mode. Another
                indicator is the median, which is the value that divides a probability distribution into two equal parts; it corresponds
                to the 50th percentile on a cumulative frequency distribution. The figure below depicts these three measures on
                a sample probability density curve. The 95-percent estimate shown on the graph indicates a low estimate having











                C-4






                Probability of                                     mode
                X amount occurring                                        median


                                                                                       n







                                            95%
                                                                                                           5%






                                                                      X                              Resources



                a 19-in-20 chance that the actual amount will be greater. The 5-percent value is a high estimate, with a 1-in-20
                likelihood that the actual amount will be greater.
                    The resource estimation process used by MMS to generate estimates under conditions of uncertainty
                incorporates a computer program called PRESTO (Probabilistic Resource ES711mates Offshore). The MMS
                requires a model that provides a range of estimates, both conditional and risked.
                    The program is objective and utilizes a large geological and geophysical database, not only from the offshore
                areas, which MMS has accumulated through regulation of OCS oil and gas exploration and development activities,
                but also from onshore and offshore State lands. The results are reproducible and revisable. This flexibility allows
                new data or new interpretations to have a quantifiable effect on the resource estimates. Results are presented as
                ranges of values rather than as single-point estimates, so that useful limits can be provided for plaiming purposes.
                The model is also functional under a wide range of uncertainty, since our knowledge of potential offshore petroleum
                provinces varies from considerable to practically none.
                    The current PRESTO program is in its third generation and incorporates many new, state-of-the-art
                enhancements. The program uses the types of geologic and geophysical data normally used by the oil industry to
                locate and defme potential hydrocarbon-bearing geologic features. These data are analyzed, interpreted, and
                eventually refined to a set of input values that numerically model all potential prospects in the study area.
                    Since these values are rarely exactly known, uncertainty is accounted for by range-of-values estimation, i.e.,
                the inputs for variables can be entered as distributions over an appropriate range of possible values. The results
                are also presented as ranges of possible values with associated probabilities of occurrence. The -variables used to
                define prospects and their resource potential are:

                         (1)      areal extent (acres);

                         (2)      zone pay thickness (feet);

                         (3)      oil recovery factor (stock tank barrels/acre-feet);
                                       V
                                                                          me(



                                                                                  mea







                                            95%

































                         (4)      gas recovery factor (thousand cubic feet/acre-feet);

                         (5)      proportion (PROP) of the zone pay thickness consisting of gas;

                         (6)      solution gas-to-oil ratio (standard cubic feet/stock tank barrel); and










                                                                                                                                C-5
                     (7)      condensate yield (stock tank barrels/million cubic feet of gas).

                Dependencies among these input variables can be specified where appropriate. TWo other zone properties
            that may be specified are (1) probability of all oil (OPROB) and (2) probability of all gas (GPROB) for each zone.
                Before calculating resources, the model first determines if hydrocarbons are present. Next it determines
            whether a reservoir contains all oil, all gas, or both (by using OPROB, GPROB, and PROP). Then PRESTO
            calculates volumes of oil, associated and nonassociated gas, condensate, and solution gas, as appropriate, for all
            hydrocarbon-bearing prospects on each trial by the following equations:

                     (1)      volume of oil, barrels = (acres) x (thickness) x (1-PROP) x (oil recovery factor);

                     (2)      volume of nonassociated and associated gas, million cubic feet = (acres) x (thickness) x
                              (PROP) x (gas recovery factor) x (0.001);

                     (3)      volume of condensate, barrels = (condensate yield) x (nonassociated and associated gas);
                              and

                     (4)      volume of solution gas, thousand cubic feet = (gas-to-od ratio) x (oil, barrels) x (0.001).

                Using the above set of inputs as the basis for estimates of resource volumes, the program uses sophisticated
            statistical sampling techniques to calculate resources. Since each input can be represented by a distribution of
            values, one point on the distribution for each variable is randomly sampled, and the selected values are entered
            into the volumetric equations to solve for resource amounts. This process is called a "driffing simulation trial" or
            "pass" and can be repeated as many as 10,000 times. On each of these trials, the model simulates a state of nature
            by "discovering!' which prospects will be hydrocarbon-bearing by using input risks to simulate drilling of each
            prospect.
                The program uses a four-level risk assessment (zone, prospect, basin, and area) to determine the number of
            trials that a prospect or zone contributes to the total. The evaluator must enter risk values that measure the
            probability that the prospect or zones within a prospect will be dry and the overall probability that the basin (and
            area) may be dry.
                Estimates of minimum economic field size for each prospect and minimum economic basin and area reserves
            in barrels of oil equivalent (BOE) are required to determine the portion of the undiscovered resource base that is
            economically recoverable. Minimum economic field sizes are calculated exogenously through use of a discounted
            cash flow (DCF) model. They represent the smallest resource amount that would balance development and
            operating costs (including transportation costs for the gathering system) for a prospect and yield a minimum rate
            of return. The minimum economic field size is tailored to the prospect, considering factors such as water depth,
            distance from shore, depth to the potential pay horizon, and current and projected economic conditions.
                By comparing the calculated resource volumes of each successful prospect to the minimum economic field
            size values provided by the user, PRESTO develops estimates of economically recoverable resources on a trial.
            The gas volumes caslculated for a prospect are converted to a volume of oil equivalent on the basis of energy or
            economic equivalency and then added to the oil volume to yield a total BOE for the prospect. If the calculated
            prospect resource volume in BOE exceeds the minimum economic field size, the prospect is considered to be
            economically viable, and its resources contribute to the total. If the calculated prospect resources are less than the
            minimum economic field size, then the prospect is considered noncommercial, and its resources are set equal to
            zero for that trial. Resource amounts greater than the minimum economic field size for prospects within a basin
            are aggregated on each trial and compared to a minimum economic basin reserve. The minimum economic basin
            reserve, also calculated exogenously, is the minimum amount of resources necessary tojustify a regional production
            infrastructure in a basin. Finally, resource amounts for all basins in an area on a given trial are compared to a
            minimum economic area reserve to determine whether enough resources are present to justify production facilities
            for the area. This feature is more appropriate for frontier areas than for mature areas with an existing
            infrastructure.
                When the specified number of trials are completed, the solutions of each trial are sorted and ranked, and the
            results are defined by distributions of solutions. Thus, the full range of possible volumetric solutions is represented
            by a single curve with each point on the distribution having an equal probability of occurrence. PRESTO outputs
            include both conditional and risked distributions. Since the output of PRESTO is a distribution of resource
            estimates, for convenience the results are usually reported using only the mean value and the 5th and 95th











                      C-6

                      percentiles. The 5th percentile can be considered a high case where there is a 5-percent chance of that amount or
                      more occurring; the 95th a low case where there is a 95-percent chance of that amount or more occurring; the mean
                      is the average value of all trials.
                           Conditional resource estimates are constrained by a number of statistical caveats, which are not intuitive. By
                      statistically aggregating the estimates of resources in each individual prospect, PRESTO calculates planning area
                      resource estimates (or any subset such as an alternative sale configuration). It does not follow, however, that the
                      total planning area estimate is the arithmetic sum of the prospect estimates. This is because each prospect has a
                      different condition (i.e., the marginal probability of hydrocarbon occurrence in the prospect). Prospect resources
                      can be aggregated to planning area totals only by rerunning the program using all prospect data and making any
                      required risk adjustments.
                           An important number associated with conditional estimates is the marginal probability. The condition. is
                      quantified by assigning it a numerical value, the marginal probability (MP). The MP is a measure of the probability
                      that hydrocarbons exist in an area and is represented as a decimal fraction. (For economically recoverable
                      resources, the MP is a measure of the probability that commercial hydrocarbons exist in the area.) An MP of L00
                      indicates certainty of hydrocarbon occurrence in the area; an MP of zero indicates no chance whatsoever. The
                      MP applies to the entire conditional distribution. As an example, consider an area having an MP equal to 0.25.
                      This means that the area has a 25-percent chance of containing a hydrocarbon accumulation. If hydrocarbons do
                      exist, then the conditional distribution represents the range of possible values. By removikg the condition and
                      incorporating the risk that the entire area may be barren of hydrocarbons, the estimates are said to be risked.
                           The following graphs illustrate conditional and risked resource distributions. Cumulative percentages are
                      given on the vertical axis and oil volumes on the horizontal axis. The conditional curve has, a corresponding MP
                      of 0.25 and, if hydrocarbons do exist, the conditional curve displays the calculated range of -values. It can be seen
                      on the conditional curve that the 50th percentile corresponds to 2.9 billion bbl of oil (BBO), i.e., there is a 50-percent
                      probability that at least 2.9 BBO will be found if there are accumulations of oil present in the area (the mean or
                      average value is 2.8 BBO, which corresponds to the 54th percentile in this case). The graphs'below show the risked
                      distribution of estimates. Note that the risked mean estimate is only 0.7 BBO (0.25 x 2.8), reflecting the low
                      probability of success in this hypothetical area. The risked curve also shows that the chance of resource amounts
                      being greater than or equal to zero is 25 percent (corresponding to the MP); there is a 75-percent chance the area
                      is dry.





                                                         100     -

                                                           75 -                                Conditional mean - 2.8 13130
                                                                                                       (54th percentile)
                    Cumulative percent                     50
                     greater than or equal to
                                                           25                                                  Marginal probability -025

                                                             0


                                                                    0                        2.9                         5.8
                                                                         Estimated volume of oil (13130)











                                                                                                                                      C-7




                                                         100 -


                                                           75 -                 Risked mean - 0.7 BBO


                 Cumulative percent                        50 -
                 greater than or equal to
                                                           25 -

                                                             0 -    I
                                                                    0                      2.9                      5.8
                                                                     Estimated volume of oil (13130)

                     The conditional mean multiplied by the MP yields the risked mean, i.e., the average value factoring in the
                 potential risk of no hydrocarbons existing in the area. However, this is statistically valid only for the mean value;
                 the 5th and 95th percentiles cannot be multiplied by the MP for risked 5th and 95th percentiles. (The 5th and 95th
                 percentiles on the conditional distribution, when multiplied by the marginal probability, will correspond to different
                 percentiles on the risked distribution.)
                     The risked mean values can be added or subtracted. However, conditional means are not additive; conditional
                 or risked percentile estimates (such as the 5th- and 95th-percentile estimates) cannot be added or subtracted.
                 Risked mean resource values are most useful in comparing different areas for ranking purposes. However, as
                 mentioned earlier, it is the conditional and not risked mean that is the amount anticipated if recoverable (or
                 commercial) quantities of oil and gas occur in nature. The following example illustrates the essential difference
                 between the two types of estimates and the need to consider both in making informed judgments and decisions.
                 Two areas have been assessed, resulting in very different conditional mean resource levels and marginal
                 probabilities:

                                                          Conditional Mean                                     Risked Mean
                                                             (million bbl)                 MP                  (million bbl)

                              Area A                             1,000                     0.10                     100
                               Area B                               125                    0.80                     100

                     The risked mean values calculated for both areas are the same. However, Area A has a larger potential (eight
                 times larger than Area B), with only a small chance (10%) of hydrocarbons existing in the area. If Area B contains
                 hydrocarbons, the average amount anticipated is much smaller, but the chance of hydrocarbons existing in the area
                 is greater (80%).
                     The distinction between conditional and risked results is further illustrated by the following example. The
                 undiscovered resources for a fictitious OCS basin are estimated to be between I and 7 BBOE, with an average of
                 3 BBOE if hydrocarbons are present in the basin. However, it is estimated that there is only a 25-percent chance
                 that this condition will be met (hydrocarbons present in the basin). In other words, if there were 100 basins in the
                 world similar to this fictitious basin, 75 would be dry and 25 would contain hydrocarbons. The 25 basins cont i i g
                 hydrocarbons would each have between I and 7 BBOE, with the average size being 3 BBOE. The average amount
                 found in the 100 basins would be reported as 750 MMbbl. This is the "risked mean" estimate. Therefore, based
                 on current geologic, engineering, and economic knowledge, if this one fictitious basin is fully explored and
                 hydrocarbons are found, the amount found will be between 1 and 7 BBOE, with an average value of 3 BBOE.
                 There is, however, only a 25-percent chance of hydrocarbons being present, so the risked mean estimate is reported
                 at 750 MMBOE. In actuality, the amount found (if our models are correct) would be either zero or between 1 and
                 7 BBOE and not the risked mean estimate of 750 MMBOE.











                 C-8
                 II. Categories of Resource Estimates
                     Various categories of undiscovered resource estimates, each responding to a different question or need, can
                 be developed using the models and methodologies described above. These estimates can be derived from a baseline
                 data set comprised of all prospects in the area. These resource estimates form a nested hierarchy, where each
                 estimate is a subset of previous estimates.

                                                                Geologic Province
                                                          (Conventionally Recoverable)
                                                             Planning I Estimate
                                                           (Economically Recoverable)


                                                                Sale Area Estimate
                                                           (Economically Recoverable)


                                                            Economically Recoverable
                                                            Resources Assumed to be
                                                                Leased Due to Sale
                                                                        f
                                                            Resources Assumed to be
                                                            Leased Due to Alternative
                                                                Sale Configurations
                     Geologic Province Estimates are the top tier of undiscovered resource estimates. These estimates were based
                 fundamentally upon analysis and review of the province petroleum geology, exploration history, play analysis,
                 finding rate studies, and structural analyses.
                     The conventionally recoverable estimates include the quantities of oil and gas resources in excess of 1 MMBOE
                 in undiscovered accumulations analogous to those in existing fields producible with current recovery technology
                 and efficiency, but without reference to economic viability. These estimates involve statistical projections based
                 upon large-scale geologic observations in entities such as basins and provinces and, as such, may not directly
                 translate to administrative regions such as planning areas.
                     For the Gulf of Mexico, the undiscovered conventionally recoverable resource estimates are divided into two
                 provinces--Cenozoic and Mesozoic. The Western and Central Planning Areas are almost entirely in the Cenozoic
                 province. The Cenozoic and Mesozoic Province estimates for the entire Gulf of Mexico are shown in the following
                 chart:

                                                                Oil                     Gas                    BOE
                                                               (BBO)                    (tcf)                (BBOE)

                              Conditional
                                   95th Percentile              5.52                    63.02                  16.73
                                   Mean                         9.57                 103.34                    27.96
                                   5th Percentile               15.12                156.92                    43.04

                              Marginal Probability     1.00

                              Risked
                                   95th Percentile              5.52                    63.02                  16.73
                                   Mean                         9.57                 103.34                    27.96
                                   5th Percentile               15.12                156.92                    43.04











                                                                                                                                     C-9
                      PlanningArea Estimates are for policy guidance and, as such, they are broad and all encompassing in nature.
                 They are used, for example, to develop the 5-year leasing program and the Biennial Report to Congress (as required
                 by Section 606, OCS Lands Act). These estimates include both prospects identified through interpretation of
                 geologic and geophysical data and prospects postulated by the extrapolation of geologic trends into areas having
                 scant data. Where justified, they may also include speculative plays, which are poorly defined by the available
                 information.
                      Planning area estimates that are described as economically recoverable include resources only from those
                 prospects that are of sufficient size to be economically producible and marketable, based on current and projected
                 economic conditions and foreseeable technological trends.
                      For the Central Gulf, the economicaUy recoverable estimates are shown in the following chart:

                                                                   oil                     Gas                      BOE
                                                                 (BBO)                     (tco                  (BBOE)

                               Conditional
                                    95th Percentile                0.30                    3.34                     0.89
                                    Mean                           1.87                    18.36                    5.14
                                    5th Percentile                 4.05                    38.57                    10.91

                               Marginal Probability      1.00

                               Risked
                                    95th Percentile                0.30                    3.34                     0.89
                                    Mean                           1.87                    18.36                    5.14
                                    5th Percentile                 4.05                    38.57                    10.91

                      For the Western Gulf, the economically recoverable estimates are shown in the foflowing chart:

                                                                   oil                     Gas                      BOE
                                                                 (BBO)                     (tcf)                 (BBOE)

                               Conditional
                                    95th Percentile                0.09                    1.73                     0.40
                                    Mean                           1.22                    17.95                    4.41
                                    5th Percentile                 3.13                    44.98                    11.13

                               Marginal Probability      1.00*

                               Risked
                                    95th Percentile                0.09                    1.66                     0.39
                                    Mean                           1.22                    17.91                    4.41
                                    5th Percentile                 3.10                    44.63                    11.04

                      For the Eastern Gulf, the economically recoverable estimates are shown in the following chart:

                                                                   Oil                     Gas                      BOE
                                                                 (BBO)                     (tco                   (BBOE)

                               Conditional
                                    95th Percentile                0.31                    0.85                     0.46
                                    Mean                           0.80                    1.11                     1.00
                                    5th Percentile                 1.54                    1.35                     1.78


                               Marginal Probability = 1.00

                        The rounding of marginal probability will not necessarily be evident in risked estimates.











                     C-10

                                                                       CONDITIONAL RESULTS - CENTRAL GULF

                                     C       100
                                     U                                                                                 95% - 0.89BBOE-
                                     M       80                                                                       MEAN - 5.14 BBOE
                                     U                                                                                 5% -10.91 BBOE,
                                     L       60
                                     A
                                     T       40
                                     I
                                     v       20
                                     E

                                               0
                                     %            0            2           4           6            8           10          12           14          16
                                                                                   BOE - BILLION BARRELS



                                                                       CONDITIONAL RESULTS - WESTERN GULF

                                     C      100   -
                                     U                                                                                 95% - 0.40 BBOE-
                                     M       80                                                                       MEAN - 4.41 BBOE
                                     U                                                                                 5% -11.13 BBOE
                                     L       60
                                     A
                                     T       40
                                     I
                                     v       20
                                     E

                                     %         0
                                                  0            2           4                        8           10          1*2          14           16
                                                                                    BOE - BILLION BARRELS



                                                                         CONDITIONAL RESULTS - EASTERN GULF
                                     C      100
                                     U
                                                                                                                       95% - 0.46 BBOE
                                     M       80                                                                       MEAN - 1.00 BBOE
                                     U                                                                                  5% - 1.78 BBOE
                                     L       60
                                     A
                                     T
                                     1       40
                                     v
                                     E       20


                                     %         0
                                                   0                  0.5                  1                 1.5                  2                  2.5
                                                                                         BOE - BILLION BARRELS











                                                                                                                                   C-11

                                                                 Oil                      Gas                      BOE
                                                               (BBO)                      (tco                  (BBOE)

                              Risked
                                  95th Percentile               0.31                      0.85                     0.46
                                   Mean                         0.80                      1.11                     1.00
                                  5th Percentile                1.54                      1.35                     1.78

                     Although estimates are shown at the 95th percentile, 5th percentile, and mean cases, these are only three
                possible numbers from a full and continuous distribution of possible values. Figures below show a conditional
                distribution for the economically recoverable resources in BOE. Gas volumes are converted to barrels of oil on
                an energy equivalent basis and then added to the oil volume. One BOE equals 5.62 Mcf of gas based on 5.8 MM
                Btulbbl and 1,032 Btu/cu ft of gas. Every point on these curves is equally probable. However, the low and high
                estimates indicate the range of possible values, and the conditional mean represents the average amount
                anticipated, given that recoverable hydrocarbons exist in at least one of the prospects modeled.
                     Sale Area Estimates are prepared to comply with sale-specific analytical requirements related to
                environmental analyses and cost/benefit studies. Oftentimes the area offered for lease is smaller than the entire
                planning area. Therefore, prospects lying outside of the proposed sale area must be deleted from the assessment.
                These estimates are undiscovered, economically recoverable resources that are based on current economic and
                technological conditions and projections. Since these estimates are more area-specific and of nearer term use than
                planning area estimates, postulated (unmapped) prospects generally are not included, except where justified on a
                case-by-case basis.
                     For Central Gulf Lease Sale 142 and Western Gulf Lease Sale 143 the entire planning area is offered for lease.
                Therefore, the economically recoverable resource estimates for the entire area offered for lease are the same as
                those estimates for each planning area.
                     The sale area estimates represent the amount of undiscovered resources offered for lease. The Resources
                Assumed to be Leased represent an assessment by the MMS staff of the amount of the sale area resources that
                would be leased, discovered, and produced as a result of the sale and, therefore, the amount upon which the impact
                analysis is to be based. For proposed Sales 142 and 143, the MMS staff considered previous leasing rates, industry
                interest, prospect distribution, economic and technological considerations, and infrastructure distribution.
                Recognizing the inherent uncertainty associated with resource estimates, the EIS includes an analysis of a range
                of potential outcomes as represented by three distinct scenarios: (1) Low Case, (2) Base Case, and (3) High Case.
                The Low Case is an exploration-only case, based on a scenario of a reasonably anticipated level of exploration
                activity, but assuming that no commercial accumulations are discovered. The Low Case is analyzed in frontier
                planning areas. The Base Case analyzes an estimate of the resources assumed to be leased, developed, and
                produced, given that hydrocarbons exist in the area (i.e., a conditional estimate) and an estimate of the exploration,
                development, production, and transportation activities appropriate to that level of resources. The High Case
                analyzes a significantly higher estimate of resource recovery and attendant exploration and development activity
                that could result from higher leasing interest than estimated for the Base Case or that could result from the
                discoveries of larger oil and gas accumulations than estimated under the Base Case assumptions. An examination
                of these levels of resources and subsequent development will cover the range of possible outcomes and impacts
                that could reasonably be anticipated to occur as a result of each sale.
                     The economically recoverable resources assumed to be leased, developed, produced, and transported as a
                result of Sale 142 are the following:

                                                             Conditional              Conditional              Conditional
                                                                  oil                     Gas                      BOE
                                                                (BBO)                     (tco                  (BBOE)

                              Low Case                           N.A.*                    N.A.*                    N.A.*
                              Base Case                          0.14                     1.40                     0.39
                              High Case                          0.31                     2.93                     0.83

                              Marginal Probability = 1.00

                              *N.A. = not applicable.










                C-12


                     The economically recoverable resources assumed to be leased, developed, produced, and transported as a
                result of Sale 143 are the following:
                                                            Conditional             Conditional             Conditional
                                                                Oil                     Gas                     BOE
                                                              (BBO)                     (tcf)                (BBOE)

                             Low Case                          NA.*                     NA.*                    NA.*
                             Base Case                          0.05                    0.74                    0.18
                             High Case                          0.13                    1.82                    0.45

                             Marginal Probability     1.00

                             *NA. = not applicable.

                     The procedures used to determine these different categories of resource estimates are similar in all cases.
                While subjectivity exists in determining inputs and which prospects are likely to be leased, judgments are
                consistently applied by specialists in each discipline. For example, inputs such as acreage and net pay are provided
                by geologists, reservoir engineering parameters are estimated by petroleum engineers, and so forth. The
                advantages of the model are that subjectivejudgments of subject matter experts are handled in an objective manner,
                and written documentation of the various judgments is provided so that the estimates can be readily updated in
                the future as new information and interpretations become avaflable.

                111. Rationale for Multiple Scenarios in Environmental Impact Statements (EIS)
                     Estimates of remaining undiscovered, economically recoverable oil and gas in a proposed sale area are
                reported in EIS's to provide the basis for an assessment of the environmental, social, and economic impacts that
                might realistically be assumed to result from a specific sale. Resource estimates serve as the focus of the assumed
                exploration and development activities that are fundamental to a rigorous assessment of the potential effects of a
                proposed sale.
                     Formerly, the impact analyses for sales were conducted on the conditional mean sale area resource (except in
                the Gulf of Mexico) with a much abridged high (5th percentile) and low (95th percentile) case analysis separated
                from the primary analysis. The assumption that the total resources estimated to be present in the sale area would
                be leased, developed, and produced as a result of the sale overstated the level of activity that would result. Since
                the bulk of the analysis involved the mean resource, a perception developed among some readers that this amount
                of resource would, in fact, be discovered and produced. This and the resulting estimates of subsequent exploration
                and development activities acquired a validity among some readers that generally could not be supported by the
                available leasing data. The uncertainty inherent in the estimates, and by inference, in the complex series of
                environmental, economic, and social effects predicated on them needed to be emphasized.
                     Recognizing the inherent uncertainty associated with resource estimates, the EIS includes an analysis of a
                range of potential outcomes as represented by three distinct scenarios. This procedure acknowledges the
                uncertainties associated with estimating the amounts of resources that will be leased and emphasizes that the
                resource estimates are presented as a range. The limits of the range of resources are constrained by low and high
                estimates, both of which represent realistic levels of exploration and development activity. Within the range is a
                Base Case estimate of resources that are believed likely to be leased, developed, and produced as a result of the
                sale. The Base and High Cases, and their attendant impacts, are presented in the EIS for the proposed action.
                     The Base Case includes undiscovered resources estimated to be leased, developed, and produced, ass          i
                that hydrocarbons exist in the area (i.e., a conditional estimate), and an estimate of the exploration, development,
                production, and transportation activities appropriate to that level of resources. The Base Case estimate is
                presumed to be the expected result if hydrocarbons are present in the sale area in commercial quamtities and if the
                sale occurs as proposed. Post-exploration NEPA analysis is obviously pointless if commercial oil and/or gas does
                not exist; therefore, the Base and High Case resources are reported as conditional estimates because these
                estimates assume that economically recoverable hydrocarbons exist and will be discovered, developed, produced,
                and transported to the market. Most of the analytical effort is focused on the Base Case because it represents the
                resource quantity that is expected to be found and developed as a result of the sale if hydrocarbons are present in
                economic volumes in the sale area. The Base Case estimate reflects the following: successes or failures since the











                                                                                                                                   C-13
                previous sales in a planning area, previous leasing rates; perceived industry interest, costs associated with
                exploration and development, existing infrastructure to transport oil or gas to market, and so forth.
                    The High Case is an estimate of a significantly higher level of resource recovery and attendant exploration and
                development activity that could result from leasing more acreage than may occur in the Base Case or that could
                result from the discoveries of larger oil and gas accumulations than estimated under the Base Case assumptions.
                The High Case estimate is a larger but stiff reasonable quantity of resources that may produce distinctly different
                impacts. Ordinarily, the effects of this scenario would be higher than those of the Base Case because they are
                predicated on more and larger discoveries. The High Case represents a more optimistic scenario and assumes
                higher than expected leasing rates, favorable geologic conditions, or improved economics.
                    An examination of these levels of resources and subsequent development will cover the range of probable
                outcomes and impacts that could be anticipated to occur as a result of a sale.
                    The object of the analysis is to scrutinize a spectrum of activity levels, rather than to assess a single scenario,
                which can change because specific estimates change during the 2- to 3-year prelease process. Representing
                resource estimates as a range recognizes the uncertainties associated with the estimation methodologies and allows
                some flexibility if the estimates should change. If revisions remain within the range of the Base to High Case
                estimates of the original assessment, no changes in the scenarios and analysis in the EIS would be necessary.
                    Regional offices develop Base Case resource estimates consistent with the data available to them. The Gulf
                of Mexico Region uses an historical approach that derives the Base Case from a rigorous analysis of past leasing
                rates. The result is a time-dependent decline in resource volume for a succession of sales, wherein each sale is
                assumed to contribute a percentage of the total planning area resource. Other Regions use (with variations) a
                methodology that extracts and aggregates the resource volumes of those prospects considered most attractive from
                the PRESTO database. These prospects usually have high industry interest and are the most likely to yield the
                highest rate of financial return by reason of size, distance from shore, proximity to transportation infrastructure,
                water depth, etc., and are thus the most likely to be leased as a result of the sale.

                TV. Exploration and Development Scenarios
                    Infrastructure for each EIS scenario (Low, Base, and High Cases) is estimated for the Exploration and
                Development (E&D) Report based on the amounts of conditional resources assumed to be leased and subsequently
                discovered and developed. The E&D Report is composed of timetables with the yearly numbers of successful and
                unsuccessful exploration, delineation, and production wells for oil and gas; the number of platforms; oil and gas
                pipeline mileage; and production schedules. The E&D infrastructure is estimated using methodologies that are
                specific to each MMS Region and based on the amount of historical information available, the evaluator's
                professional judgment, and the geologic, engineering, and economic uncertainties associated with each sale area.

                V Cumulative Analysis
                    In August 1989, USGS and MMS published the National Oil and Gas Resource Assessment (NOGRA) of the
                undiscovered conventionally recoverable oil and natural gas resources of the United States. It considers new
                geological, technological, and economic information and uses more definitive methods of resource appraisal than
                previous assessments. The assessment was conducted over a period of more than two years and reflects data and
                information available as of January 1, 1987. The Eastern Gulf was reassessed through the acquisition and
                interpretation of geological and geophysical data after the NOGRA was released; the Central and Western Gulf
                resources were updated to reflect leasing, and resource estimates are dated as of January 1, 1990, and published
                in July 1991 by MMS in the report Estimates of Undiscoverei4 Economically Recoverable Oil and Gas Resources.
                The NOGRA is the basis for the generation of both the sale area resource estimates and the Cumulative Case
                resource estimate.
                    Conditional resource estimates are directly comparable between Gulf of Mexico planning areas, since they
                are generally based on equivalent marginal probabilities (M.R = 1.00 for all three planning areas). Planning area
                resource estimates derived from the NOGRA will be provided for the Cumulative Case Analysis for individual
                lease sale EIS's. This resource estimate takes into consideration the marginal probabilities of each planning area.
                It provides a resource estimate that gives a better indication of the likelihood of oil and gas activities occurring
                within the planning area over the life of the proposal and provides consistency in the Cumulative Analysis from
                one EIS to the next.
                    For the purposes of EIS analysis, conditional mean resource estimates derived for any planning area assume
                that the sales on the 5-year schedule in that planning area will result in exploration, development, and production.










                 C-14
                 It is logical to assume that exploration and/or development could occur from more than one salt. in the pl
                 area at the same time, and this could continue throughout the life of the leases from those sales. Therefore,
                 Cumulative Analysis is based upon an estimation of the resources explored, developed, and produced during the
                 productive life of leases in a planning area from the proposed sale, reasonably foreseeable future sales, and prior
                 sales.
                     The cumulative number will remain valid until the NOGRA is changed. Consequently, the analysis of the
                 cumulative case for a sale in a given planning area will be similar for all other sales in that planning area, provided
                 the NOGRA does not change. There will likely be some differences in the discussion of the contribution of the
                 proposal to cumulative impacts from EIS to EIS, which will provide a consistent analysis of the Cumulative Case
                 for all sales on the 5-year schedule in a given planning area. This method of analysis avoids the problem. of using
                 a different basis for the Cumulative Analysis in a given area from one EIS to the next, which would result in
                 inconsistent, conflicting analyses in the EIS's.












                                                                       Appendix D



                                                      Alternative Energy Resources
















                                                      ALTERNATIVE ENERGY SOURCES AS AN                                                                                                              In response to these events, the U.S. and the rest of the world instituted a wide variety of measures to
                                                                                                                                                                                                coriserve energy and to find alternative sources of supply. The results of these efforts to reduce imports
                                                         ALTERNATIVE TO THE OCS PROGRAM                                                                                                         generally haw been successful. The underlying market structure for energy has heen altered. World demand
                                                                                                                                                                                                for oil peaked in 1977 and appears to be in a structural decline. Gross national products haw been rising
                                       A. INTRODUCTION                                                                                                                                          alongwith nonenergyoutputallemadve-energysouroes, and non-OPEC (Organization of Petroleum Exporting
                                                                                                                                                                                                Countries) production. The Overall success for these measures -as reflected by the 1984 decline in the world
                                                                                                                                                 oduction.                                          The inability of the OPEC to secure the cooperation of its members to reduce production and halt this
                                           The oil and gas that could become available from the proposalcould add to National domestic pr                                                       oil price to about S29.00 per barrel.
                                       TO delay or eliminate the proposed sale in pan or in whole would reduce future OCS oil and gas production.                                               price slide contributed to decisions by certain OPEC memben to substantially increase production. During
                                       necessitate escalated imports of oil and gas. and/or require the development of alternative-energy sources to                                            1986, the combination of lower clentand-initially brought about as a response to high OPEC pricing--and the
                                       replace the energy resources expected to be recovered if the proposed sales took place.                                                                  decisions to increase rates of production resulted in very rapid declines in oil prices to levels that -ere
                                           If the proposed sales were canceled, an additive effect of greater 00 and gas deficits could be expected to                                          inconceivable only months earlier. During 1986, world oil prices on the spot markets also frequently fell to
                                       result in increased imports; and the following energy actions or sources might be used as substitutes. (Some                                             levels well below $10.00 per barrel; by year's end, prices had increased modestly to approximately S15.00 per
                                       of these actions are not feasible at this time and may not be feasible during the estimated production fife of                                           barrel.
                                       the proposed actions.)
                                           Imported Oil and Gas                                     (See Section B of this appendix)                                                            2. Environmental Effects
                                           Coal                                                     (See Section C)
                                           Coal Conversion to Synthetic Fuels                       (See Section D)                                                                                 The primary hazard to the environment from increased oil and gas imports is the possibility of oil spills,
                                           Oil-Shale Conversion to Synthetic Fuels                  (See Section E)                                                                             which can result from intentional or accidental (tanker casualties) discharges. For a more detailed discussion
                                           Biomass Conversion to Synthetic Fuels                    (See Section F)                                                                             of the environmental effects from oil spills, see Section IV.A_ of this EIS. Intentional discharges would result
                                           Domestic Onshore Oil and Gas                             (See Section G)                                                                             largely from uncontrolled deballasting of tankers. The effects of this chronic, low-level pollution are largely
                                           Geothermal Power                                         (See Section H)                                                                             unknown. The worldwide tanker-caswity analysis indicates that, overall, an insignificant amount of the total
                                           Solar Power                                              (See Section 1)                                                                             w1unic of transported oil is spilled due to tanker accidents. Howewr, a single incident--suchas the breakup
                                           Wind-Turbine Power                                       (See Section J)                                                                             of the Torrey Canyon in 1967 or the Amoco Cadiz in 19178--can haw disastrous results. Further. even relatively
                                           Hydroclecuric Power                                      (See Section K)                                                                             small spills from tankcring of imported oil can have major effects on serisitive coastal environments. For
                                           Nuclear Power                                            (See Section L)                                                                             example, in Less than one year, two spills occuirred off San Francisco and generated serious effects on marine
                                           conservation                                             (See Section M)                                                                             and coastal birds around the Farallon Islands National Marine Sanctuary and up and do" the mast of
                                                                                                                                                                                                California. Owr 2,000 seabirds wen: killed by the Puerto Rican tanker spilL which contacted the Farallon
                                           This appendix briefly discusses these alternatives. For more detailed information on each of these energy                                            Islands. The assessment of currittlatin effects in the Proposed 5-Year OCS Leasing Program (USDOI. MMS,
                                       sources and their respective environmental effects, refer to "Energy Alternatrws: A Comparatwe Analysts"                                                 1987) includes the "finniated mean number of oil spills associated with importing oil and refined products via
                                       (University of Oklahoma, 1975). prepared for the Bureau of Land Management by the Science and Public                                                     tanker. The assumed frequency of tanker spills greater than 1,000 barrels wast 1.3 spills per billion barrels
                                       Policy Program of the University of Oklahoma and the Proposed 5-Year Outer Continental Shelf Oil and Gas                                                 transported. Further, only one-half of the 1.3 spills per billion barrels was assumed to occitr in U.S. waters.
                                       Leasing Program, Mid-1997 to Mid-1992 (USDOI, MMS, 1987).                                                                                                The estimated most likely number of Large oil spills from tankering of imported oil used in the cumulative
                                                                                                                                                                                                case-based on estimated imports over a 30-year period-was equal to 61 spills of 1.000 barrels or greater. This
                                       B. IMPORTED OIL AND GAS                                                                                                                                  compares with an estimated most liliely number of 157 spills from all sources (all past and future OCS leasing,
                                                                                                                                                                                                all domestic and import tankering). Thus. oil spills associated with imports represent nearly 40 percent of all
                                       1. Background Considerations                                                                                                                             oil spills greater than 1,000 barrels over the 30-year period used in the assessment of cumulative effects.
                                                                                                                                                                                                3. Conclusions
                                           Spurred by new discowries and competition. Middle East oil production expanded in the 1950's and 1960's.
                                       New markets were opened and prim softened. Between 1948 and 1977, the real price of oil fell. The U.S.                                                       Major oil spills from waluers could result in the most significant environmental effect associated with the
                                       consumption of oil simultaneously increased while production remained constant; imports were relied upon to                                              use of imported 0101. Addithimad major environmental conmins include effects from tanker spills that Occur in
                                       make up the difference.                                                                                                                                  sensittye &mss that are otberwise protected from Oil spills, e.g., the Farallon Islands; air-quality effects
                                           Three major shocks to the world oil market focused public attention on oil-supply issues. The 1973-1974                                              associated with tanker unkladings; and increased vessel traffic and port congestion.
                                       Arab oil embargo cut off Middle Eastern oil sources from unrestricted trade in world oil markets and resulted
                                       in escalation of oil prim from a pre-embargo world price of $7.74 per barrel in 19,70 to a postembargo price
                                       of S24.40 in 1975. The world oil market received its second major jolt during the 1979-1980 Iranian revolution,
                                       which once spin reduced oil-supply Levels and accelerated prim to a 1980 world price of S4136 per barrel.
                                       In 1990, the political instability of the Arab region once, again forced world oil prices to the S40.00 per barrel
                                       price range.



                                            


     C. COAL

     1. Background Considerations                                                                                                                                                                                  Coal Overview
    
           C oal is our Nation's most abundant fossil fuel, with more than one-quarter of all the world's known coal                                                                                                (million short tons)
     within U.S. borders. More than one-half of our Nation's electric power is coal generated (DOE, 1990).
        Coal is a combustible rock that contains mom than 50 percent by weight and 70 percent by volume of
     carbonaceous material from the accumulation, and physical and chemical alteration, of vegetation.                                                 Year                      Production       Consumption               Imports        Exports
    Classification of coal is based on chemical analysis and certain physical reactions; that measure the progressive
     response of coal to  heat and/or pressure. The analysis involves the determination of four constituents: (a)
                moisture, (b) mineral impurity (ash), (c) volatile material (gas/vapor), and (d) fixed carbon (solid residue after                                1980                      829.7            702.7                     1.2            91.7
     removal of the gases). Based upon these constituents, coal is ranked from low-ranked lignite through                                              1981                      823.8            732.6                     1.0            112.5
     subbituminous and bituminous coal to high-ranked anthracite and meta-anthracite.  Ninety-seven percent of                                         1982                      838.1            706.9                     0.7            106.3
     the U.S. coal reserves are either bituminous (66%) or subbituminous (31%), with the remaining coal being                                          1983                      784.9            736.7                     1.3            77.8
     anthracite.                                                                                                                                       1984                      895.9            791.3                     1.3            81.5
        Most of the bituminous coal produced in the U.S. is burned to obtain thermal energy for generating                                             1985 (a)                  886.1            818.6                     2.0            92.7
     electricity, processing raw or manufactured material, and heating industrial complexes (Tables D-1 and D-2).
     Other uses include gasification and liquefaction (Sections Cl. and C-2. of this appendix).
                                      
                                                            Table D-1                                                                                                            Source:  Energy Information Administration, Annual Energy Review 1985, (a) Preliminary.

                                               Coal Consumption by End-Use Sector                                                                                        The total demonstrated U.S. reserve base is about 488 billion tons (Table D-3).  The Federal Government
                                                        (million short tons)                                                                                        manages about 60 percent of the coal resources within Colorado, Montana, New Mexico, North Dakota, Utah,                                
                                                                                                                                                                    and Wyoming.  At the close of Fiscal Year 1983, 18 competitive and noncompetitive coal leases were issued
                                                                                                                                                                    covering 22,108 acres.  As of September 3
0, 1982, 691 coal leases covering 1,288,310 acres were active (USDOI,
                                                                                                     Residential                                                    1984a).
                                    Electric           Coke                    Other                    and
           Year                     Utilities         Plants                 Industrial              Commercial                                                                                             Table D-3

                                                                                                                                                                             Demonstrated Reserve Base of the Major Coal Provinces in the United States
           1980                     569.3             66.7                      60.3                     6.5                                                                                             Demonstrated reserves
           1981                     596.8             61.0                      67.4                     7.4                                                                                             (in millions of tons)
           1982                     593.7             40.9                      64.1                     8.2
           1983                     625.2             37.0                      66.0                     8.4                                                              Province                  Underground              Surface                    Total                                                                Surface
           1984                     664.4             44.0                      73.7                     9.1          1985(a)                  693.5             40.9  

 Appalachian               97,000                      19,200       
                                                                                                                                                                                                                                                             Interior                  94,000                      41,400
           Source:  Energy Information Administration, Annual Energy Review 1985,(a) Preliminary.                                                          Western                   140.900                     95,200
                                                                                                                                                                                                                                                  331,900                    155,800

																											
                                               

                                                                                                                                                                                                   Source: Energy Information Administration, Annual Energy Review 1985.

                                                                                                                                                                                                   Coal showed a slight recovery in 1984 and 1985 after a series of setbacks due to the recession and the                                                                                                                      Coal showed a slight recovery in 1984 and 1995 after a writs of setba                                                                                                                                                    falling export market (Table D-2).  Coal usage indicated an increase of Coal consumption, particularly by the
                                                                                                                                                                                                   utilities and steel industries (Table D-1). Coal production has increased steadily to a record 975 million tons
                                                                                                                                                                                                   in 1989.
    















                                                2. Environmental Effects                                                                                                                                          transportation facility. The transport of coal necessarily involves fugitive dust emision, which further affects
                                                                                                                                                                                                                  the air quality
                                                    Numerous environmental effects can result from the mining and combustion of coal-and-disturbance                                                                 Combustion of coal results in the emission of carbon dioxide, sulfur oxides, and nitrogen oxides, which
                                                effects of mining, reclamation procedures; acid-mine-drainage problems; problems of air pollution, including                                                      contribute to the problems of acid min and potential climatic warming (greenhouse effect). Acid rain is beiing
                                                the local and global effects of sulfur oxides and carbon-dioxide emissions; and problems associated with                                                          recognized as a major environment concern that adversely affects aquatic and terrestrial ecosystems. Many
                                                transportation. While existing environmental problem related to the present coal-fuel cycle am likely to                                                          uncombusted or partially combusted carbon compounds, including known or potential mutagens and
                                                increase in scale, additional problem are Likely to arise as; new coal-gasification and liquefaction plants begin                                                 carcinogens such as polycyclic aromatic hydrocarbons am also emitted during coal conbustion. These
                                                operating. Thew new plants may be needed to offset the shortfall in availability of existing fuels if OCS oil                                                     carbon-compound emissions am cause for ecological and human-health concern
                                                and gas is reduced through delay or elimination, in part or whole, of the proposed OCS leasing program.
                                                    Coal cars be mined by two methods-surface mining and underground mining. Surface-minabie coal                                                                 3. Conclusions
                                                accounts for about 32 percent of the demonstrated coal reserves in the U.S. (Table D-3). Surface mining can
                                                result in effects on air, land, and water by creating conditions that promote water and wind erosion, destruction                                                      The major environmental effects of expanding coal production include disruption of large areas of land
                                                of topsoil. elimination of vegetation, and contamination of sod and water from weathering of toxic straw.                                                         surface with surface mines, additional acid-mine-drainage problems, and the greater air-quality effects
                                                    According to Federal Office of Surface Mining Final EIS (1980), surface mining of coal completely                                                             associated with burning coal rather than natural gas or ad in power plants.
                                                eliminates existing vegetation, destroys the genetic soil profile, displaces or destroys wildlife and wildlife habitat.
                                                degrades air quality in the area, alters the current land uses, and-to some extent--changes the general                                                          D. COAL CONVERSION TO SYNTHETIC FUELS
                                                topography of the area being mined. without diligent reclamation, surface-mined lands are often unsuitable
                                                for other uses.
                                                    The Department of Energy (DOE) Environmental Development Plan on Coal Extraction and Preparation                                                              1. Background Considerations
                                                (USDOE, 1979) reports significant water-qualily degradation from former mining sites, with severe effects on
                                                aquatic ecosystem. Streams and reservoirs (primarily in the eastern U.S.) have been affected by sedimentation                                                          Synthetic-fuel development has, slowed down due to the sagging price of crude oil that resulted from a
                                                from surface mines, acid-mine drainage, and erosion of spoil piles from mining and coal cleaning and                                                                world surplus. Oil-price moderation, soaring costs, and lack of Federal assistance have led operators
                                                preparation.                                                                                                                                                      throughout the U.S. to shelve, delay, or abandon commercial syafuel ventures. Some operators have kept their
                                                    Surface-mining effects on ground water include: (a) drainage of usable water from shallow aquifers. (b)                                                        projects in order to alleviate future depression of fossil fuels.
                                                lowering of the water table in adjacent areas and changes in flow direction within aquifers, (c) contamination                                                         Coal can be converted to synthetic fuel by either gasification (synthetic gas) or liquefaction (synthetic
                                                of aquifers below mine operations from leakage of mine waters, and (d) increased infiltration of precipitation                                                    liquid). These processes involve the breaking, or "cracking:, of heavy hydroc
                                                on spod piles. The improper removal of overburden can cause the [on of topsoil and exposure of the parent                                                       molecules and the simultaneous enrichment of the molecules with hydrogen.
                                                material. and can create vast wastelands. The stockpiling of topsail from the area ran destroy or alter many                                                           Water is required in both processes as a source of hydrogen and for other process steps (e.g., removing
                                                of the natural sod characteristics.                                                                                                                               sulfur compounds and in a cooling component). In general, lower-quality coals (lignitic, subbituminous, and
                                                    Surface mining of coal causes indirect and direct effects on wildlife that mine primarily from the removal                                                    bituminous) are more efficiently converted in synthetic fuels than anthracite (Rickert et al., 1979).
                                                and redistribution of the land surface. The area being surface mined (open pit) and the associated stockpiles
                                                am not capable of providing food or cover for wildlife. Without proper rehabilitation, the area must go                                                            a. Coal Gasification
                                                through a weathering period and may require a few years to several decades before vegetation is re-established.
                                                Broad and long-Lasting effects on wildlife within the area can occur from this alteration of the habitat.                                                               The coal-gasification process uses coal to produce gaseous fuel products that can be directly combusted
                                                    Mechanical cleaning of coal also causes effects on land use. Although the amount of land required for                                                        in a boiler, used as chemical feedstock. or used as a product that can be converted into liquid fuels (see Sec.
                                                disposal of coal-cleaning wastes varies with coal- extraction techniques and characteristics, National estimates                                                     D.l.b of this appendix).
                                                range from 0.3 to 0.9 acres used per million ton of coal cleaned.                                                                                                       Three ingredients are required to chemically synthesize gas from coal- carbon, hydrogen, and oxygen. The
                                                    Underground mining of coal has the potential to result in subsidence, dropping of the water table, or                                                          synthesis is performed by reacting coal under sufficient heat with steam and air. Depending on combustion
                                                interception of surface-water drainages. Subsidence is probable inmost underground coal mining. Depending                                                            (air vs. pure oxygen), the gas produced is either a low-Btu (100-200 Btu's standard ft') or medium-Btu (300-650
                                                upon the degree of extraction, subsidence occurs immediately or at wine future time. Subsidence may disrupt                                                       Btu's) gas. The medium-Btu gas can be further processed by methanation to produce high-Btu (950-1,050
                                                aquifers, damage surface facilities, and trigger mud slides or rock falls. In wine cases, subsidence can lead to                                                   Btu's) gas (Bentz and Salmon. 1981).
                                                permanent loss of coal resources.                                                                                                                                    Several types of gasifiers are commercially available for the production of low and medium Btu gas
                                                    The health and safety of mine workers are major concerns associated with both surface and underground                                                          (Koppers - Tetzek, Winker, and Lurgi). A detailed discussion on the chemical and design considerations, as
                                                mining. Safety and health hazards to the workers, especially in underground mining, am the highest of any                                                         well as a process description, can be found in "Environmental. Health, and Control Aspects of Coal
                                                industry. Additional discussion on effects associated with coal development can be found in the Final EIS on                                                     Conversion: An Information Overview" (Braunstein et al., 1977).
                                                the Proposed Federal Coal Leasing Program (USDOI, 1974).                                                                                                               Coal gasification seems to be the leading commercial-scale synfuel project throughout the world. In the
                                                    Coal is transported by rail, truck, water, slurry pipeline, or conveyor belt. The environmental effects of coal                                                   U.S., only 30 coal-to-synthetic-fuel projects were in operation in 1981. Of these, only 8 are commercial
                                                transport occur during loading. while enroute, and during unloading. All forms of coal transport exhibit                                                           operations. The remainder are demonstration/pilot plants or process-development plants.
                                                common environmental-effect factors. All forms use land for terminal/handling plan is or for railroad                                                          The state-of-the-art gasifier available for use in gasification of the highly caking easternbituminous coal and
                                                installations or pipeline throughways. Rail transport and trucks cause damage to buildings, and trucking cause                                                     other coals is an atmospheric Koppers-Totzek unit. The most advanced gasifier is the pressurized Texaco
                                                major structural damage to highways. Air pollutants and nose are emitted from engines powering the                                                                gasifier.
																																															D-5








																																															D-6



                                             b. Gas liquefaction                                                                                                                                            E. OIL-SHALE CONVERSION TO SYNTHETIC
                                                 Coal can be liquefied by both direct and indirect processes. Indirect-liquefaction processes convert coal                                                 1. Background Considerations
                                             to liquid products by first gasifying coal to a mixture of carbon monoxide and hydrogen (synthetic gas) and then
                                             allowing these gases to react in the presence of a catalyst to form liquid products. In the direct-liquefaction                                                    The production of synthetic fuels from oil shale provides an alternative- energy source. Oil shale is a
                                             process, a coal slurry is reacted directly with hydrogen in the presence of a catslyst, thus eliminating the step                                              fine-grained, sedimentary rock containing material called kerogen. Kerogen is of high molecular weight and
                                             involving the indirect-liquefaction  process. After hydrogeneration. the Solids and liquids am separated. The                                                  has low solubility in any solvent. The only practical method of recovering hydrocarbons from the oil shale is
                                             residual solids are then burned in a gasifier to generate hydrogen and steam. The quality of the liquid can be                                                 by heating the rock to high temperatures (approximately 500C and thereby recovering shale oil and
                                             either a boiler-fuel grade or a synthetic-crude grade.                                                                                                          hydrocarbon gases process known as retortin. The retorting of oil shale can be achieved by (a) surface
                                                 The Fisher-Tropsch process, which converts synthetic gas to a liquid product has been operating in South                                                   retorting, (b) in stitu retorting, and (c) modified in just retorting.
                                             Africa's Sasol plants using a commercial gasifier (Lurgi). These facilities convert coal mined onsite into 27                                                      Them are two methods for surface retorting of oil shale-the direct- and indirect-heat methods. In both
                                             different fuel and chemical products. The combined coal consumption of all three plants will be about 33                                                      cases, heat is required to bring about pyrolysis of the raw shale. In the direct-heated process, the heat is
                                             million metric tons per year. It is predicted that Sasol, Ltd., could produce sufficient quantites of hydrocarbon                                              supplied by the creation of a combustion zone within the retort. In the indirect-heated processes, gases are
                                             to make South Africa self-sufficient (Engineering and Mining Journal, November 1982).   Four major                                                               circulated to an external reactor for combustion. Heat is transferred back to the retort by recirculating gases
                                             direct-liquefaction processes am underdevelopment Solvent Refined Coal (SRC) I and 11, H-Coal. and Donor                                                         or solids through the retort and the external reactor.
                                             Solvent.                                                                                                                                                           In situ retorting refers to a process of retorting the shale in place, without the removal of any material.
                                                                                                                                                                                                            This eliminates the disposal problem associated with surface processing. In this process, the oil shale is
                                             2. Environmental Effects                                                                                                                                       fractured underground, after which heat is introduced to liquefy the kerogen. The produced oil is then
                                                                                                                                                                                                            removed through wells, utilizing natural permeability.
                                                 The major potential environmental, health, and socioeconomic problems related to coal conversion are                                                           The modified in situ oil-shale process involves mining or removing up to 30 percent of the shale from the
                                             terrestrial, air- and water-quality, effects resulting from discharged effluents, air emissions, and solid-waste                                               retort zone so that void volume is created and permeability is increased. The remaining oil shale in the retort
                                             disposal associated with mining, transportation. and processing of the coal. (See Section C of this appendix                                                   is then explosively fractured and retorted in place. In the case of leached shale, the shale is not fractured: hot
                                             for a discussion of the effects associated with the Mining of coal 10 Supply coal-gasification or liquefaction                                                gas is injected  the retorting medium. Retorting can then be accomplished by moving the retorted oil enher
                                             plants.)                                                                                                                                                       horizontally or vertically.
                                                 In its EIS on Synthetic Fuels and the Environment - An Environmental and Regulatory Impact Analysis                                                            After retorting, the raw shale oil is processed to remove water and other contaminants by a separation
                                             (USDOE, 1980), the DOE reports that substantial quantities of solid-waste material will be generated or each                                                     system that typically consists of a closed-cycle processing unit. such as impingement or centrifugal separators,
                                             stage of Elie coal-conversion process. Waste material will be generated directly from the process that is part                                                or mechanical demisters. The principal functions of the system are separation and recovery of oil or gaseous
                                             of the original feed. such as ash, unreacted carbon in the form of chars and tan. and fly ash from auxiliary                                                   products from contaminants that include water produced in the retorting process as well as particulate material
                                             boilers. Secondary wastes consist of added materials/chemicals, such as catalysts or coal conditioners, time from                                                carried over the retort.
                                             scrubbers, and added reactants from water treatment.                                                                                                                Following product recovery, crude shale oil requires further treatment to remove nitrogen, oxygen, and
                                                 There is concern for the health and safety of workers since many hazardous and toxic substances are                                                         sulfur compounds and to reduce viscosity and pour points to allow pipeline or tanker transport. Removal of
                                             formed and used in the synfuel process. Many substances am identified carcinogenic materials that can form                                                     the nitrogen compounds requires a special refinery procces.
                                             in coal conversion, e.g., benzo(A)pyrene, dibenz(a,h)anthracene, chrysene, and 7-methylbenz(c)-acridine as well                                               Large areas of the western U.S. are known to contain oil-shale deposits; those in the Green River
                                             as aromatic asmines (e.g., naphthylamine and benzidine) (USDOE. 1980).                                                                                        Formation in Colorado. Wyoming, and Utah have the greatest commercial potential. the oil-shale resources
                                                 Air-quality emissions; from coal-conversion fatilities can include sulfur oxides, particulate matter, nitrogen                                              of the Omen River Formation am estimated at 54 billion barrels of recoveralbe oil with an assay of 30 gallons
                                             oxides, hydrocarbons, hydrogen sulfides ammonia, hydrogen cyanide. polunuclear aromatic hydrocarbons,                                                            per ton, and 600 billion barrels of reserves in place from shale with an assay exceeding 25 gallons per ion.
                                             nitrogen and sulfur containing heterocyclic compounds, and trace elements. The appropriate use of existing                                                     Therefore, the Green River Formation represents 20 to 30 times the known reserves of conventional crude oil
                                             available technology should control source emissions to levels in compliance with applicable current regulations.                                             in the U.S.
                                                 Wastewater will result from numerous sources within the process. Standard treatment system using                                                               Development in the U.S. shale industry is concentrated in Colorado's piceance Basin, where approximately
                                             flocculation and biodigestions should prevent water quality problems.                                                                                           85 percent of the western high-grade deposits are found (Rickets et al. 1979). The oil-shale projects, in some
                                                                                                                                                                                                            cases, are funded or underwritten by the DOE Several of the projects am experiencing the effects of soaring
                                             3. Conclusions                                                                                                                                                 costs, sagging oil prices, and delayed development. Many of the companies are extending their timetables and
                                                                                                                                                                                                            reducing production goals.
                                                                                                                                                                                                                In the eastern U.S., the shale deposits underlie Indiana, Ohio, Illinois, Kentucky, Tennessee, Michigan, and
                                                 The major environmental effects of expanding the use of coal in synthetic-fuel production include                                                         Pennsylvania. The eastern shales are of a lower quality than the western shales, but the deposits are more
                                             air-quality effects generated by synthetic-fuel plants, wastewater generated in the production of synthetic fuels,                                             extensive. The eastern shale has a poor carbon-hydrogen ratio and is therefore required to be retorted in the
                                             and concerns for the health and safety of writers in synthetic-fuel plants.                                                                                     presence of hydrogen. In contrast, Elie western shale requires only the application of heat to release the oil.
                                                                                                                                                                                                                There is an estimated I trillion barrels of recoverable reserves within U.S. deposits. The 1-trillon-barrel
                                                                                                                                                                                                            figure is based on hydrogen retorting rather than on Fischer assay (international Petroleum Encyclopedia.
                                                                                                                                                                                                            1982).



















                                         and uncertainties related to the vegetation of retorted shale include water requirements, accumulation of toxic                                           2. Environmental Effects
                                         trace substances in the vegetation, and long-term stability.
                                              Potential problems with stability of waste piles will require several years to emerge. and uncertainties will                                           The conversion of oil shale to synthetic fuels will haw effects on air, land, and water quality. These effects
                                         remain for 10 to 20 years. Spent shale can either be returned to the mine or stockpiled above, in which case                                             am  related to various air emissions, effluent discharges, and solid-waste disposal (spent shale from surface
                                         it will becompacted and vegetated or otherwise stabilized to prevent erosion by wind or water. Dust control will                                         retorting).
                                         be accomplished by application of water or chemical wetting agents. Surface-disposal options include filling                                                   Air-quality concerns relate to (a) the production of both criteria pollutants and (b) particulate matter and
                                         valleys and recontouring surfaces. The major consideration is to ensure that the large quantities of spent shale                                            noncriteria pollutants associated with dust from mining and crushing of raw shale, and resuspension of disposed
                                         can be economically disposed of with minimum out environmental damage.                                                                                     spent shale.
                                              The occupational work force will be exposed to an environment largely uncharacterized in terms of                                                      Control of particulates resulting from the production of oil shale can be a problem. For large surfaces at
                                         industrial hygiene and safety analyses. The miners will be subject to exposure to possible toxic materials.                                                the mime, "wetting" or vegetation of the stock piles is an adequate control, whereas for more limited areas (e.g.,
                                                                                                                                                                                                  conveyors and crushers), baghouse filters, scrubbers, and cyclones am used to control particulate emissions,
                                         3. Conclusions                                                                                                                                           Fugitive emissions due to traffic and wind am a potential problem and may require the use of chemical
                                                                                                                                                                                                  additives and best control-management practices.
                                              The major environmental effects of oil-shale development include: effects from disposal of spent shale,                                                 Sulfur in raw-oil shale amounts to about 0.7 percent by weight, either as organic sulfur or associated with
                                         air-quality effects from dust and vehicle emissions, disruption of land. the large quantities of water needed in                                        iron pyrite. During retorting, about 40 percent of the organic sulfur in shale appears as H2S in the produced
                                         processing, and water-quality effects from wastewater disposal.                                                                                        gases; and the other 60 percent appears a heavier sulfur compounds in the raw shale oil, spent shale, or water
                                                                                                                                                                                                  residuals. If shale oil or low-Btu gas from the retort is used for steam generation or any other combustion
                                         F. BIOMASS CONVERSION TO SYNTHETIC FUELS                                                                                                                 process, sulfur oxides will be formed and flue-gas-desulfurization scrubbers will need to be used for tail-gas
                                                                                                                                                                                                  cleanup. The kerogen fraction of the raw shale can contain up to 2 percent of nitrogen. The extent of NO
                                                                                                                                                                                                  formation from the use of retort off-gases or shale oil to hear the retort will be related to 
                                         1. Background Considerations                                                                                                                             flame-temperatrue-residence time and the air/fuel mixture. Combustion efficiency during oil-shale retorting
                                                                                                                                                                                                  is not expected to be a significant problem. Ile HC and CO emissions will therefore be small. The low-Btu
                                              Biomass conversion is the process of transforming biomass (organic material) into usable energy sources.                                            gas formed during retorting will either be flared or used for onsite steam prpdictopm with traditional
                                         This conversion transforms the biomass into (a) liquid form (alcohol) or (b) methane gas.                                                                flue-gas-cleanup controls.
                                              A boimass-fueled gasification project that will convert peach pits into gas is planned for a greenhouse in                                                 Water-resource effects encompass effluent control and water-supply issues. In the semiarid Piceance and
                                         Lodi, California. This is the first commercial application of an automated, small-scale. biomass-fueled gasifier                                            Uinta geological basins in Colorado and Utah. where most of the high-quality-oil-shale resource is found, water
                                         in California (California Energy Commission, 1984). The gas produced will be Used to supply heat to                                                      pumped from mines or drawn for process use is expected to be recycled or consumed. Effluent problems are
                                         greenhouses. The system will result in a substantially reduced energy cost compared with the existing natural                                            focused on potential contamination of aquifers and surface waters by leachign form spent-shale piles,
                                         gas system. As a result, the growers will be able to expand their growing seasons, increase plant yield, and                                             evaporative and lagoon concentrates, or burned-out in situ retorts, rather than from direct emmissions.
                                         expand their market to include high-energy plants.                                                                                                       Problems with in sisu processes concerning backflood water and fugitive-gas emissions may result in
                                                                                                                                                                                                  contamination of ground-wateraquifers. Ground-watersupplies and surface-water supplies fed by ground-water
                                         a. Ethanol and Methanol                                                                                                                                    aquifers might be affected for very king periods of time, thereby creating difficulties in securing adequate water
                                                                                                                                                                                                  supplies for retort operation.
                                              Ethanol from grain is one of the alternative fuels that can be produced from a renewable resource.                                                      Wastewater from surface-retorting operations (up to 8 gallons/ton of input shale and more from some in
                                         Ethanol can partially replace current transportation fuels derived from petroleum. Although ethanol can be                                                     Operations) and process water from product, upgrading operations will have to be controlled. Wastewater
                                         produced from grain, 70 percent of the high-proof ethanol is made synthetically from ethylene gas derived from                                               can then be used for moisturizing spent shale. Under current planning, oil-shale developers envision zero
                                                                                                                                                                                                  discharge of their wastewaters.
                                         petroleum (USD0E,1980).                                                                                                                                     Disposal of spew shale and storage of raw shale could create land disturbances of large magnitude,
                                              Ethanol may also be derived from any carbohydrate source, such as starch in corn and other grains. The
                                         DOE (1980) reports that nearly 12 billion gallons Of ethanol would be required to produce a National                                                        potential accumulation of toxic substances in vegetation, and contamination of ground waters and surface
                                         10-percent alcohol/gasoline blend by the year 2000. Assuming an average yield of 100 bushels per am and                                                    waters from runoff.
                                         an ethanol yield of 2.5 gallons per bushel, this amount of alcohol would require 48 million additional acres of                                                  The DOE (1980) reports that retorted shale contains varying amounts of organic and inorganic residuals
                                         corn production.                                                                                                                                         depending on the retorting process. It presents a major solid-waste-management and disposal problem for the
                                              Methanol production a based upon the gasification of wood to produce a medium-Btu gas followed by a                                                  surface and modified in situ operations from both the amount and its content. Retorted shale will have a 
                                         chemical reaction to combine water and carbon monoxide to form hydrogen and carbon dioxide (Section C                                                    density of about 75 to 100 pounds per cubic foot after compaction. This means that for every 50,000 barrels
                                         of this appendix).  Additional carbon monoxide is combined catalytically with hydrogen to produce methanol.                                               of surface-retorted shale oil produced, there will be enough spent shale to occupy a volume of almost 2 million
                                              Forest residue-"slash" cattings left behind after conventional logging, stump/toot system-can be used                                          cubic feet or about a 2-foot depth over a square mile for every month of operation.
                                         to generate methanol. A recent assessment estimated that forest-industry waste(lumber and pulp mills) could                                             Above-ground-retorted shale from modified in situ operations would have considerably less solid waste for
                                         serve as the major resource for methanol production.                                                                                                     disposal. Large areas are required for the storage of raw shale and the disposal of retorted shale. The
                                                                                                                                                                                                  resulting potential loss of habitat for plant and animal communities and natural erosion of the disposal piles
                                                                                                                                                                                                  by wind and water may not be fully mitigated by vegetating or physically stabilizing the  disposal piles. Problems


																																																	D-7 








                                                                                                                                                                    

















																																														D-8



                                             b. Organic (Urban) Waste                                                                                                                                      Residual wastes (solids remaining after the fermentation process) have been estimated for a 
                                                                                                                                                                                                       20-million-gallon-per-day ethanol plant. The amount of raw waste might range from approximately 12 to 55
                                                 The basic processes for converting urban waste to energy are combustion, pyrolysis, and bioconversion.                                                gallons per Salkin of product. The waste may contain contaminants equivalent to 0.12 to 0.17 pound of (5-day
                                             Each process requires waste collection and transportation. some processes require mechanical preprocessing                                                  biochemical oxygen demand/gallon of ethanol product). 
                                                                                                                                                                                                           Approximately 0.5 pound of excess activated sludge can be expected for ea
                                             to separate the municipal solid waste into are refuse-derived fuel and other noncombustible and                                                             Assuming that the raw waste contains 0.17 pound of BOD5 per gallon of product
                                             nonbiodegradable materials. Some of the noncombustible and nonbiodegradabe materials such as ferrous
                                             metal, aluminum. and glass are recyclable.                                                                                                                 corresponds to 961 tons of BODS removed per 1,012 Btu's produced. Excess
                                                                                                                                                                                                       per 1,012 Btu's.
                                                 Combustion of urban wastes in waterfall boilers is the most developed process, with eight plants                                                               For a 170,000-gallon-per-day methane plant with activated-sludge treatment, it has been estimated that 0.64
                                             commercially operating in U.S. cities. Urban-waste furnaces am being demonstrated at a facility processing                                                   ton per day of SODS would be produced along with 6 tons per day of waste-activated solids and 25 tons per
                                             600 tons per day in Milwaukee, Wisconsin; and a 200-ton-per-day unit has been undergoing tests (joint                                                      day of ash and unburned carbon.
                                             Environmental Protection Agency [USEPA] and DOE sponsorship) with 50-percent refuse-derived fuels at
                                             Ames, Iowa. since 1974.
                                                 Pyrolysis or thermal-gasification processes have been tested in Charleston, West Virginia; Baltimore,                                                  b. Organic (Urban) Waste
                                             Maryland; and El Cajon, California. Municipal solid waste is decomposed in an oxygen-deficient atmosphere
                                             to produce combustible gas and liquids. Scrubbing is used to remove hydrochloric acid, hydrogen sulfide. and                                                   Waste-conversion processes greatly reduce municipal solid-waste volume but still leave waste residuals that
                                             SO, Wastewater is a byproduct that requires treatment.                                                                                                    go  into landfills or impoundments. The chemical composition and source (domestic, industrial) of the
                                                 The bioconversion process for convening solid and liquid urban wastes into methane is in the research and                                         municipal solid waste-leachability of fly and bottom ash, pyrolysis byproducts, scrubber sludge, and the
                                             early pilot-plant stages. The processes leave a waste-disposal problem in the form of liquid-digester residues,                                           anaerobic digestion sludge-is a concern. Selection of landfill sites and facility siting may be affected
                                             microorganisms, and inorganic nonbiodegradable material. A DOE-sponsored digestion plant at Pompano                                                           Effluents discharged at disposal Sims (pits, ponds, lagoons) are likely to contain the same ingredients that
                                             Beach, Florida, and the ANFLOW project am currently producing methane.                                                                                    are present in raw municipal waste and my pose a hazard to water resources and ecosystems.
                                                                                                                                                                                                           Waste-plant, front-end processing, storage, and transport operations may pose an occupational hazard to
                                             2. Environmental Effects                                                                                                                                  workers. Data indicate that dust, micro-organisms, hazardous chemicals, and noise are all highest close to
                                                                                                                                                                                                       equipment for providing and storage of municipal wild waste. Emissions from combustion and co-combustion
                                                                                                                                                                                                       facilities am known to contain fly ash, organic compounds, and trace elements and are a health-and-welfare
                                                 Biomass conversion to Synthetic fuels, and its residual wastes, will have effects on water and air quality and                                        concern.
                                             on the land (erosion and nitrogen depletion of the soil). Additionally, the general public may be exposed to                                                    The presence of combustible dust may create explosion hazards. These operations also expose the general
                                             aesthetic problems-dust, noise, and odor. Following is a description of the adverse effects on the ecosystem                                              public to aesthetic problems (dust, noise, and odor), which can result in siting problems. Traffic flow in the
                                             from biomass conversion.
                                                                                                                                                                                                       vicinity of the plant is also a concern.
                                             a. Ethanol and Methanol                                                                                                                                   3. Conclusions
                                                 Growing core for ethanol production requires large amounts of nitrogen. In order to prevent nitrogen loss                                                The major environmental effects associated with expanded production of synthetic fuels generated from
                                             in the sod, rotation of crops with legumes or the use of anhydrous ammonia would be required. The runoff                                                  biomass include the land erosion associated with farming and silviculture water-quality effects associated with
                                             and leaching of pesticides and fertilizers would accompany increased gram cultivation. This can have an
                                             adverse effect on the ecosystem and possibly on humans.                                                                                                   wastewater disposal, residual solid wastes, and air-quality effects-especially from burning urban waste for power
                                                 The loss of Sediments due to erosion, as well as the leaching of sales, could cause a wide variety of effects                                         generation.
                                             on ecosystems and could came a reduction in land productivity.
                                                 Extensive Production Of methanol from silviculture-biomass resources may disturb up to 50 percent (350                                               G. DOMESTIC ONSHORE OIL AND GAS
                                             million ACM) of current forest land. In addition to pollution effects, methanol production has the potential
                                             to cause Severe ecosystem effects, such as the elimination of the range of certain species, elimination of                                                1. Background Considerations
                                             threatened and endangered species, and elimination of specific ecotypes.
                                                 Silviculture-biomass production and residue-removal schemes have the potential to significantly increase                                                                                                                              
                                             air and water erosion of the soil Erosion of the soil from cleared areas is fairly predictable and can be serious                                               The Annual Energy Review 1985 estimated that onshore, undescoverable oil resources ranged
                                             in areas Of high rainfall and hilly topography.                                                                                                              from 42 billion barrels (Bbbl) of oil with a 95-percent probability to 71 Bbbls with a 5-percent probability
                                                 Silviculture for methanol productions should not contribute to air pollution as dusting does to farming. For                                               (mean resource of 55 Bbbl). Onshore, natural gas resources range from 320 trillion cubic feet (tcf) of gas with
                                             a plant that would process 2,000 tons per day of green wood and produce 170,ODD gallons per day of methanol,                                                 a 95-percent probability to 570 tcf of gas with a 5-percent probability (mean resource of 430 tcf).
                                             it has been estimated that 1,000 tons per day of COS, would be vented into the atmosphere (USDOE. 1980).                                                      The major areas for oil and gas activities (exploration and development)
                                             With the generation of methanol from wood using an estimate of 0.25-percent product loss to the air, 1.4 tons                                              regions: the Rocky Mountain Region, the Mid-Continent, and the Eastern Overthrust Belt. According to the
                                             per day of hydrocarbons am estimated. The facility would also generate 0.44 ton per day of particulate                                                    1984 international petroleum Encyclopedia, 7,914 new-field wildcat wells were completed during 1982, with
                                             emission from the grinding room. When grain starch is converted to alcohol by means of hydrolysis and                                                     1,402 wells completed as producers-for a success rate Of 17.72 percent That compares with 17.67 percent
                                             fermentation, approximately equal weights of ethanol and carbon dioxide are formed in the process.                                                           producers in 1981 and a record 19.05 percent in 1980. The 1,402 new-field discoveries of 1982 represent a
                                                                                                                                                                                                       1.5-percent decrease from 1981. The American Association of Petroleum Geologists estimated that 1982's














                                             new-field discoveries contained reserves of 651.64 million barrels of oil and condensate and 3.84 tcf of gas-                                                H. GEOTHERMAL POWER
                                             decrease of 0.2 percent in liquids and 10.7 percent in gas from figures reported for 1981.                                                                  1. Background Considerations
                                             2. Environmental Effects
                                                                                                                                                                                                             Geothermal energy is the heat contained in and continuously flowing from the earth. Today, it is proving
                                                 The environment can be affected by the different phases of oil and gas activiry- exploration and                                                         to be a viable source of energy for the generation of electricity and space heating. There are four different
                                             development, and production. The environmental effects of onshore oil and gas are similar to those already                                                      types of high-grade geothermal reservoirs that my be exploitable-(a) the hyperthermal system, (b) the
                                             described (SectionsIVA. and IV.B. ofthis EIS). Them include physical, biological, and socioeconomic effects.                                                geopressured system, (c) the molten-rock system, and (d) the hot-dry-rock system. At the present time, only
                                             resulting from drilling activities, transportation, and processing of the oil and gas.                                                                     the hyperthermal system is viable.
                                                 In the exploratory phase, two activitities-off-road-vehicle, traffic and exploratory techniques-would have an                                                The hypertbermat systems that are being exploited around the world have extremely high temperatures
                                             effect on wildlife populations and habitaits. Noise from heavy-duty exploratory vehickes and associated human                                                (500-600F) and often occur at depth (frequently 2 miles). All occur in hot, fractured rock with a high water
                                             involvement would adversely affect wildlife, particularly ground-nesting birds, reptiles, and burrowing animals.                                           content. This water serves as a heat-exchanage, medium that flows into the boreholes. The heat is then carried
                                             Seismic exploration utilizza explosives, thumpers, and vibrators to test for oil and gas resources. These                                                  to the surface and to the electrical-generating turbines. The pressure of the overlying rock and water generally
                                             techniques disturb wildlife by disrupting their habitat and creating loud, sudden noise.                                                                   keeps the water in the reservoir in a liquid state, even when temperatures are far above the liquid's boiling
                                                 Off-road vehicles, seismic activity, drilling of test wells, excavation of construction materials (sand and                                             point. However, as the drill bit penetrates the cap rock of the reservoir, the pressure is relieved and the
                                             gravel), and building of service roads and drilling pads muse sail particles to become unconsolidated and                                                  contained water flashes to steam. A few reservoirs such as those found at the Geysers, California, and
                                             increase the sod's susceptibility to wind and water erosion. The disposal of drilling muds and dumping of waste                                             Lardarello, Italy, consist ofsuperheated, high-pressure steam.
                                             oil in sump pits would contaminate sails in the area of drilling sites.                                                                                         The largest geothermal development is underway at the Geysers Geothermal Field in California's Sonoma

                                                 In areas where unstable soils are located and the potential for natural revegetation is low, such activities                                           and Lake Counties, located about 90 miles north of San Francisco. The Field yields almost 750,000 kilowatts
                                             can muse long-range effects on surfact-water quality, increase erosion, and decrease wildlife habitat and                                                  ofinstaffedelectrical-geacmtingmpacity. I'Lanspresently call for an additional 220,000 kilowatts of
                                             vegetative cover. Accidents such as fires, explosions, well blowouts, spills, and leaks can lead to major                                                  Predictions are that full development in the Geysers Field will account for about 2 million kilowatts of
                                             contamination and higher temperatures for surface waters when oil entem streams, ponds, or lakes, and to                                                   generating capacity by the end of the decade (International Petroleum Encyclopedia, 1982).Pacific Gas and
                                             adverse effects on terrestrial vegetation.                                                                                                                 Electric Comparrys complex of 17 geothermal power plants at the Geysers produced a record 6 billion
                                                 Oil and gas activity can cause degradation of water quality and reduction of water supplies. During                                                    kilowatt-hours of electricity in 1983 (California Energy Update, AugustS, 1984). Table D-4 for annual U.S.
                                             exploration, water supplies can be lost or reduced from seismic testing, stratigraphic testing,and wildcat drilling                                          production of electricity from geothermal sources.
                                             During exploration, the ground-water hydrology can be altered from the fracturing of impermeable zones below
                                             aquifers, permitting the water resources to be lost or reduced through vertical drainage. Well drilling can also                                                                                                  Table D4
                                             require large quantities of water, especially if porous and permeable formations are encountered. Oil spills
                                             and/or leaks, blowouts, and spills or leaks of caustic, salty, or polluted water can mine adverse effects.                                                                                  Production of Electricity from Geothermal Source
                                                 During the development and production phase, the removal and handling of water from producing wells
                                             and separation facilities can cause further degradation of surface-water quality. Upon abandonment of a
                                             producing oil field, those facilities that contain residual oil, brine waste, or solid wastes may cause further water
                                             pollution. Batteries, tanks, sumpt, and pipelines may deteriorate and release pollutants into adjacent surface                                                                                                   Net Summer						
                                             and ground waters.                                                                                                                                                                                                   Capacity				Production 	
                                                 Injection of additional waters into a producing well may become necessary during the production phase                                                                                                            On-Line				(million
                                             to obtain additional oil production through flooding with massive amounts of water. This maybe either fresh                                                              Year                                  (thousand kilowatt&)			kilowatt-hours)
                                             or produced (brackish) water. Such production techniques generally require additional water resources and
                                             deplete the availability of ground-water supplies.
                                                                                                                                                                                                                     1979                                            667				3,889
                                             3. Conclusions                                                                                                                                                          198D                                            909				5,073
                                                                                                                                                                                                                     1981                                            909				5,686
                                                 The major environmental effects associated with expanded production of onshore oil and gas resources                                                                1982                                          1,022				4,843
                                             include effects on pristine areas from roads; off-road-vehicle traffic; and other oil and gas infrastructure that                                                        1993                                         1,207				6,075
                                             generates loss of natural vegetation and erosion, effects on air quality, and effects on water quality.                                                                   1984                                        1,231 				7,741
                                                                                                                                                                                                                     1985                                          1,590				9,325


                                                                                                                                                                                                                     Source: Energy Information Administration. Annual Energy Review, 1985.




	Another development program is underway in southern California's Imperial Valley. The geothermal
resources present would generate more than 3 million kilowatts of electrical power capacity.  A second
prospect, Herber, in the Imperial Valley, contains enough geothermal energy to provide a capacity of 500,000
kilowats for at least 30 years (International Petroleum Encyclopedia, 1982).
	Utah Power and Light has proposed a 20,000-kilowat electrical power generating plant fueled by
geothermal energy from Roosevelt Hot Springs, in southwest Utah.  Phillips Petroleum has also entered into
a commercial geothermal venture at Roosevelt Hot Springs. The Roosevelt prospect is thought to be capable
of supporting 200,000 to 400,000 kilowatts of power capacity.  Other areas of potential development include
the Jemez Mountians in New Mexico, Dixie Valley in Nevaga, and Desert Peak in California.

2. Environmental Effects

	Enviromental effects from the development of geotherman resources vary depending upon the pre- and
postlease exploration and development activities, and the nature of the geothermal find. The chief effect from
the use of geothermal power occurs during the period of development of the field and construction of the
steam-gathering lines and power plants.  Natural steam does contain a small percentalge of noncondensable
gases, including hyfrogensulfide and methane, that are vented to the air and that may affect air quality in
the area.
	Any effects of geothermal development upon climate will be localized and should not affect regional
patterms.  Local themerature patterns will change by several degrees due to waste heat emitted from the power
plants, particulary form the cooling towers.
	According to the Department of the Interior (1980) Final EIS for Proposed Leasing within the COSO
Known Geothermal Resource Area, the principal gaseous emissions associated with geothermal development
are the noncondensable gases hydrogen sulfide (H2O) and carbon dioxide (CO2), and water vapor from flow
testing and from cooling towers.  In addition, fugitive dust will be emitted into the atmosphere as a result of
construction and vehicle activity and by wind erosion.
	Noise effects can result form direct geothermal acitvities such as well drilling and power-plant operation,
and from related activities such as automobile and truck traffic.  noise can also result from developmental
operations, during perparation and construction of well pads and power plants. Futher noise effects are likely
to occur during drilling, cleanout, and flow testing of new wells; noise associated with these activities is
short-term.
	The operation of the power plant represents the major long-term, continuous noise source resulting from
geothermal development. Major contributors to the noise inclide cooling towers, turbines, and steam-jet
ejectors. The cooling towers, which are physically large and have a large-band-frequency spectrum, become
the dominant noise source at distances greater than 200 ft from the unit.
	Subsidence and seismic acitvites may be accentuated during the production phase.  The potential for
subsidence is greatest in hot water systems produced from unconsolidated sediment. Since the majority of
geothermal systems are in more competent rock, they are not subject  to large amounts of subsidence.
Geothermal systems are often found in areas of seismic activity. Possible fault movements can result from the
removal and reinjection of fluids causine cyclic variations in reservior pressures.
	Geothemal development requires cooling water, which could displace other uses or degrade other supplies.
It also produces enormous amounts of liquid waste requiring disposal.  Exploration and well drilling and
construction of development facilities can cause short-term effects of surface erosion and drilling waste disposal.
This could cause alteration of surface runoff and erosion patterns, sediment yield, and ground water
degradation. The development and production of geothermal energy could lower the water table. Degradation
of the natural water could locally reduce the temperature of the fluids, causing mineral precipitation and/or
depletion of the geothermal reservoir.
	The amount of land used and altered ranges from zero in the very earlist stages of exploration to many
tens of acres in a field that has undergone fuel-stage development. Surface-disturbing activities generally are
(a) road building; (b) drill-pad, power-line, and/or other facility site construction; and (c) construction and
clearance of pipelines and transmission facilities.
	Effects on wildlife could result due to increased vehicular traffic, drilling activities, removal of wildlife
habitat, and noise associated with construction and production activities.
	Recreational use would be affected by noise, dust, traffic conflicts, or physical displacement from specific
recreation-use areas. Public-safety concerns could restrict recreational use of an area until drilling operations
ceased, Geothermal development could modify the landscape character of an area if striking contrasts ocurred
in form, line, color, or texture of land-scape features.

3. Conclusions

	The major enviromental effects generated by increasing use of geotherman resources include the
considerable noise associalted with the operation of many geothermal-power plants, air-quality effects,
development pressures in pristine areas, and water quality effects.

I. SOLAR POWER

1. Background Considerations

	The sun is the earth's most abundant source of energy. Only an infinitesimal fraction of the sun's radiant
energy strikes the earth.  It is estimated that about 180 trillion kilowatts of electrivity- more than 25,000 times
the world's present industrial-power capacity- is received. However, this energy requires conversion to a 
suitavle form.
	Solar energy can be captured either directly through rooftop collectors, photovoltaic cells, and 
building-design features or indirectly through storage of solar energy in nature. In comparison to producing
energy from conventional fuels, direct solar energy is relatively clean and pollution-free.
	Solar systems convert the sun's radiation into energy for heating and air conditioning by means of
absorptive coolers, industrial- process heat, and electricity generation. Photovoltaic cells convert sunlight directly
into electricity, although the relatively low conversion efficiency required large collector areas. Another method
of utilizing solar power is solar thermal, where in the sun's rays are directed by mirrors to a central point and
are then capable of being used as the heating source for a thermal-ower plant.  There are four different
solar-thermal systems that have different temperature ranges, applications, and types of collectors: (a) solar
pond, 140-180 Degrees F; (b) flat plate, 100-205 Degrees F; (c) parabolic concentrating, 300-1,500 degrees F; and (d) heliostats,
500-2,000 Degrees F. Much of the recent work in solar energy production has focused on reducing the manufacturing
costs of solar collectors, improving their efficientes and reliabilities, and simplifying their design and
installation.
	Solar technologies will require more land per unit of capacity than will conventional-energy system due
to the diffuse nature of the solar resource and the generally low effciencies of solar devices. If the facility is
to provide process steam to an industry or utility, the collectors must be in close proximity to the point of end
use. If the plant is electricity generating, it must give a clear access for an electrical interconnection with the 
local-utility-grid network. The amount of available solar radiation at a specific geographic location dictates the 
number and size of the collertors required. The amount of available solar radiation can vary dramatically from
site to site. Table D-5 gives an estimate of the collectors-area-to-land-area ratios.




















                                                                                                     Table D-5                                                                                                  The solar reflections from heficistats and parabolic collectors Can be wry qinte
                                                                                                                                                                                                           must be talmn when working in the arm of operating collectors. The solar
                                                                                     Solar Energy Collector to Land Ratios                                                                                 approximately 70 heliostats in Albuquerque, New Mexico, melted through a one-
                                                                                                                                                                                                           minutes. Therefore, cleaning and maintaining the mirrored surfaces must be a ni
                                                                                                                                                                                                                Biological resources can be affected during the installation and development s
                                                   Collector                                      Collector Arm                              Land Area                                                     possible effects from support activities, such as road building to provide access to
                                                                                                                                                                                                           ofelectric-leader and transmission lides, and constructionand maintenance ofsubs
                                                                                                                                                                                                           low due to solar-encrgy development would occur during the constiruction of roads,
                                                   Solar Pond                                                                                      1.0                                                    power-distrioution and transmission lines. Other indirect effects include increased
                                                   Flat Plate                                              1.0                                 2.0-2.2                                                     visual disturbance, and subtle habitat changes, such as the invasion of new plant
                                                   Photovoltaic Amy                                        1.0                                 20-2.2
                                                   Parabolic Trough                                        1.0                                 2.2-2.4                                                     3. Conclusions
                                                   Parobolic Dish                                          1.0                                 3.4-3.9
                                                   Heliostats                                              1.0                                 3.0-3.8                                                          The major environmental effects generated by increased use of solar-eneqrgy p
                                                                                                                                                                                                           major land areas needed for reflectors or heliosuits with attendant loss of wildlife
                                                                                                                                                                                                           from hctiostats; and air- and water-quality effects associated with the manufa
                                                           Source: Sheahan, 1981.                                                                                                                          However, operation of solar-energy-production facilities does not cause air- or -a

                                                   Legal right to the sun is an important aspect ofsolar power. Height of structures, trees, or land features
                                              on adjacent Land-especially on the south side-is important because of potential shading of the collectors.                                                   J. WIND-TURBINE POWER
                                              Sheahan(1981) reports the recommendation that there be an uninterrupted view ofthe south down to an angle
                                              of 10 degrees above the horizimand clear to the southwestland the southeast. 10 the point-here the sun rises                                                   1. Background Considerations
                                              and sets on the summer solstice. This area may need to be controlled through legal restrictions or land
                                              acquisition.                                                                                                                                                      Wind has been used as an energy source for centuries. Historians believe tha
                                                   Land surfaces need to be as flat u possible with grades not exceeding 10 percent. If the land is contoured,                                            probably were primitive devices used to grind grain in Persia around 200 B.C. N
                                              mom spacing would be required due to potential shading from collectors on the higher ground.                                                                 producing small wind machines (less than 100 kilowatts) to be used in homes,
                                                   Areas with excessive wind would need to be avoided, since windblown sand and dirt would erode mirrored                                                  businesses. Although the home market for -led turbines is growing rapidly, ener
                                              collector surfaces. Similarly, high wind could cause structural damage to the sail-like crillectors. Hailstones and                                          of wind technology most beneficial it) the Nation will he the large turbines that fe
                                              heavy snowfalls could also damage the collectors. In addition, adjacent industrial facilities may give off air                                               Sewral utilities are experimenting with wind power.
                                              emissions that could erode mirrored collector surfaces.                                                                                                           A wind turbine needs a supply of wind in order to operate. The whicity, dir
                                                                                                                                                                                                           and duration) of the wind would need to be calculated prior to site selection. Po
                                              2. Environmental Effects                                                                                                                                     buildings, vegetation. and other wind turbines can affect the supply of wind to a w
                                                                                                                                                                                                           velocity can be altered, and the turbulence can be increased.
                                                   'Me major environmental effect of solar-energy-conversion systems results from the relatively large surface                                                   A decrease in veloLity means that reduced energy output and an increase in
                                              area required for the collectors and from disruptions that occur during development. During the manufacture                                                  the energy output and, perhaps more critically, reduce the useful life of the turbin
                                              of phatrivotatic cells, minimal air-quality effects would result, with some waver-qualfty degradation occurring                                             am mom of a problem with small machines and with machines in urban areas. 7
                                              due to discharge of wastr-rinse solutions. Other effects from solar-energly development include cooling-water                                                 in rural areas that would affect wind turbines is another wind turbine.
                                              (aqmde-tlkermal-poflutioa)requirements, height requirements forat solar-powcr tower, and heat and fight-beam                                                      Southern California Edison's 10-year resource plan calls for generation of 2,1
                                              intensity from mirror collectom                                                                                                                              renewable resources by 1990. Wind turbines could contribute almost 7 percent
                                                   Solar energy will mot contribute to air pollution except during the production of solar equipment or during                                             1.226 trillion kilowatt hours on an annual basis (USDOI. 1982). Southern Ca
                                              the cleaning of the nibrors. Increasing solar use will cut emissions of particulate$. hydrocarbons, sulfur oxides,                                           360,000 kilowatts of ind-Vilerated power by 1990 (international Petroleum En
                                              carbon monstiodes, and nitrogen oxides. At the same time, solar syster" will not increase atmospheric                                                            Imerrtationalfttroieurs Encyclopedia (1982) reports that the Pacific C43 and
                                              cartion-dioxide levels that could cause major changes in global climate.                                                                                     signed a otintract with Whadfamna. Ltd.. of San Francisco to buy most of the 360,OC
                                                   Some solar-thermal electric plants with once-througly cooling could haw significant water requirements.                                                 This pro)= will entaff installation of 146 wind turbines at a cost of about $700
                                              Lzakage and disposal of antifreeze and anticorrosion fluids from solar heating and hot-water systems could                                                   1989, it could yield as much as 963 million kilowatt-hours of electricity.
                                              produce a minor water-pollution problem                                                                                                                           PG&E also plans to purchase all the electricity to be generated by a win
                                                   'Me height of a solar-power tower is significant and could be potentially as high as lj(M It (cc a                                                      Windpower of Butingtors, Masaachusetis. The project urvohm installation Of 600
                                              IOD-megawatt plailL Therefore, if a solar-plant site is proposed in proximity to an airport or major airline                                                at an estimated cost of S60 in 11 n.
                                              route, special pnecautions are required.                                                                                                                          California Energy Update (August 8, 1984) reports that wind-project deve
                                                                                                                                                                                                           announcing and installing record numbers of wind turbines. Over Z400 wind tort,
                                                                                                                                                                                                           megawatts have been approved by zoning commissions and planning councils
 










                                                                                                                                                                                                                                                                                                                                            C1





                                          developers. Major permitted wind-turbine projects include Altamont Pass, a total of 7,626 wind turbines: San                                              worseningof flood-hazard potential and downstream-sedimentcleposition. Changes in natural drainage mums
                                          Gorgonio Pass. a total of 1,352 wind turbines; and Tehachap4 280 wind turbines. A total of 2,400 turbines have                                            could also increase channel erosion,
                                          already been erected at Altamont Pam.                                                                                                                          Wind turbines may interfere with television reception by causing visual distortions. Sengupta et al. (1980)
                                                                                                                                                                                                    report that interference to television reception is caused by the scattering of television signals by the wind
                                          2. Environmental Effects                                                                                                                                  turbines. In the vicinity of an appropriately oriented wind turbine, a television receiver will receive the
                                                                                                                                                                                                    scattered signals in addition to the direct signal. The scattering by the rotating blades of the wind turbine will
                                                The primary environmental effects that would result from wind-turbin"nerly production include adverse                                               Produce both amplitude and phase modulations of the signals at the m4miver. Since video information in
                                          ecological effects from site ilmlopmentand presence ofthe structures, noise levels, interference with television                                          television signals is transmitted by amplitude modulation, any extraneous amplitude modulation will. if
                                          reception. and potential recreational and visual conflicts.                                                                                               sufficiently strong, distort the video recieption.
                                                Biological resources can be affected by many stages ofwind-energy development, including initial material                                                The upper ultra-high-frequency channels am found to be particularly vulnerable to such distortions. For
                                          acquisition and processing. turbine production and assembly, and turbine installation and operation. Thereare                                             a given television channel, the maximum distance from the wind turbine at which adverse interference may
                                          also many possible effects from support activities, such as road building to provide accesa to turbine sites,                                             occur is a function of the ind-turbine-blade dimensions and orientations and the recetving@ntenna
                                          developmentofelectric-feeder and transmission lines, and construction and maintenance of substations. Other                                               characteristics. The size of the interference decreases as, the television-channel number is decreased.
                                          indirect effects include increased human activity, noise and visual disturbance,and subtle habitat changes, such
                                          as the invasion of new plant species in disturbed areas.                                                                                                  3. Conclusions
                                                The USDOI (1982) reports that the direct effects of wind-energy development on biological resources
                                          include two min categories; (a) low of animals through surface disturbance at turbine sites and in road and                                                    Expanding the generation of electricity with wind power would cause the following major environmental
                                          along powerline rights- of@war, and (b) at substation sims, disturbance of animal behavior through interferc=                                             effects: disturbance of sizable areas with thousands of giant windmills disrupting existing uses and affecting
                                          with courtship, rearing of the young, feeding, and other necessary aspects of animal-life histories.                                                      wildlife, visual impacts, considerable noise generated by the operation of windmills, and wind turbines
                                                Wildlife activity "old decrease significantly in the immediate constructionarea or facility site. and animal                                        interfering with television reception.
                                          habitats near development will often be deserted. If associated long-term indirect effects are high, the
                                          developed area may be permanently abandoned. Such indirect effects include immediate habitat loss as well                                                 K. ENDROELECTRIC POWER
                                          as long-term, cumulative habitat deterioration.
                                                The potential exists for low incident rates of collision between birds and wind-turbine generaton.
                                          Placement of Large turbines along ridge tops may affect the behavior of large soaring birds that utilize air                                              1. Background Considerations
                                          currents deflected upwards by the terrain as a source of lift Certain species, including small mammals and
                                          lizards, would be very vulnerable to crushing and other direct effects from construction of the turbines and                                                   Hydroelectric sites operating today were developed in the early 1950's. 'Me total developed and
                                          roads.                                                                                                                                                    undeveloped hydroelectric power in the U.S. is 6.75 trillion kilowatt hours (Table D-6).
                                                Noise effects can result from the construction of the wind turbines by earth-moving equipment and
                                          increased traffic on [omI roads and highways in the study area. There are a number of potential noise sources                                                                                                  Table D-6
                                          fromwind-turbineoperations. Noise would be generated from the operation of the generator, the transformer,
                                          and the gearbox, and from the wind-turbine blades. 'Me turbine blades would be the predominant noise source                                                                          Hydroelectric Power in the United States - Total Potential
                                          in the far-field of the wind turbine. "Me other noise sources would generally be discernible only in the
                                          near-Geld of the wind turbine.
                                                Noise would be generated from a number of phenomena associated with wind- turbine-blade interaction                                                                                                                               Average Annuai
                                          with the air. The primary causes of noise are (a) fluctuating lift resulting from the interaction of the blades                                                                                                                               Generation
                                          with the atmospheric turbulence of the wind, (b) interaction of the blade turbulent-boundary layer with the                                                            Geographic Division                                           (1,000 kilowatt hours)
                                          trailing edge of the blade. (c) direct acoustic radiation from the turbulent-boundary layer, (d) direct accustic
                                          radiation from the wakes of the bladm and (c) interaction of the tower wake with the turbine blades on wind
                                          turbines where the blades are downwind of the tower. Of these causes, the first two are the dominant muses
                                          of noise. Noise associated with the operation of the wind turbines has become an increasing concern with                                                               New England                                                            13,599,232
                                          residents in the area of the wind park.                                                                                                                                Middle Atlantic                                                        37,763,815
                                                Placement of the turbines in an amsi can cause a reduction in the area's suitability for recreational and                                                        East North Central                                                     9,779,997
                                          other Land uses. Conflicts have &risen due to the potential placement of wind parks in areas designed for                                                              West North Central                                                     17,645.343
                                          wilderness review, and in areas of highly concentrated archaeological resources. Wind turbines are highly                                                              South Atlantic                                                         34,324,480
                                          visible because of their height. Wind development in an area would haw a significant visual effect on the                                                              East South Central                                                     27,879,762
                                          character of the existing landscape. Visual aesthetic effects would result from removal of vegetation; soil                                                            West South Central                                                     10,595,090
                                          disturbanots associated with construction of -irul-tower pads, amiess and service roads. electrical-transmission                                                       Mountain                                                               97,658,028
                                          lines; and introduction of a variety of wind-turbine structures.                                                                                                       Pacific                                                                249.284.546
                                                Wind and water erosion are likely to result from the construction of wind farms in an and environment.                                                           Alaska                                                                 176,290,145
                                          Localized desert-pavement development would occur as a result of consiLruction. This could result in a                                                                 Hawaii                                                                    333,400
                                                                                                                                                                                                                 Total - United States                                                  675,133.&M

                                                                                                                                                                                                                 Source: Federal Power Commission, 1976.


















                                           a. Hydroelectric Dams                                                                                                                               the system. An increase in basin evaporation loss could occur due to (a) the existence of a large open body
                                                                                                                                                                                               of water and (b) increased evapotranspiration of emergent aquatic plants.
                                               Conventional hydroelectric developments convert the energy of naturally regulated stream flowS to produce                                            A change of water chemistry would be detectable within the reservoir, and in some cases would cause
                                           electric power. The construction of a dam for hydroelectric power interrupts the flow of a river, creating a lake                                   stratification of the water, represented by deep-water, oxygen-depleted zones. These zones would be unable
                                           or reservoir behind the clarn. This alters the physically unstable fiveruse ecosystem and shifts it into a relatt"                                  to support fish life. Decomposition within the reservoir of submerged vegetation and organic material may
                                           stable tacustrum ecosystem.                                                                                                                         produce an explosive release of chemical nutrients into the bicsystem. Alteration of water temperature would
                                               PG&E's 65 hydroelectric pistils produced three times more energy in 1983 (almost 18.1 billion                                                   occur not only within the reservoir but also downstream influenced by lake-water outflow from the dam.
                                           kilowatt-hours) than in 1982. In addition to production from its oust hydro plants, PG&E purchased 24.5                                                 Depending on factors such as moisture content. temperature, and movement of air masses, along with
                                           billion kilowatt-hours of economical hydro power produced mainly in the Pacific NorthWeSL Hydroelectric                                             regional topography and size of reservoir, alteration in the local nucroclinnate may result from a hydroelectric
                                           poomr accounted for 59 percent of the electricity available to PG&E customers in 1993.                                                              impoundment. The biological systems in the reservoir area and downstream usually show marked changes as
                                                                                                                                                                                               a result of the dam's effect on the hydrologic system. This mn have an effect on both terrestrial and aquatic
                                           b. Pumped-Storage Project																				     ecosystems. The terrestrial habitat above the dam shrinks as the reservoir fills, yet the land/water interface 
                                                                                                                                                                                               increases.  Both factors will be reflected in the floral and faunal changes.
                                               Pumped-storage projects generate electric power by releasing water from an upper pool to a lower storage                                            If seasonal flooding has been arrested downstream, long-established patterns of water/soil-fertility
                                           pool and then pumping the "ter back to the upper pool for repeated use. A pumped-storage project                                                    relationships would be altered. Net reduction of sod-moisture content and changes in nutrient input and
                                           consumes mom energy than it generates but Converts off-peak, low-value energy to high-value, peak energy.                                           nutrient cycling would result in changes in flora and fauna.
                                           To meet peak-load requirements, power companies haw been utiliting puMped-storage hydroelectric stations                                                The initial flooding that covers plants, animals, and organic-soil components stage for a sudden
                                           to a greater degree. Them are many advantages to pumped-storage hydroelectric power. which increases the                                            release of nutrients into the water. This mn cause an increase in the density and extent of higher aquatic
                                           number of sites acceptable for Construction of dam whose primary purpose is to supply peak-po.er needs.                                             plants. An increase in the aquatic plants within the reservoir can, in turn, cause interference with human
                                               Relatively small strearn flows can support large generating Capacities, since "ter is stored and a portion                                      activities such as boasting, fishing, and even power generation (should the turbines or water intakes become
                                           ofitcanbereused. The pumped-storage plant also does not require a large stream in a deep, natural valley.                                           clogged). For migratory aquatic (e.g., fish) species, a hydroelectric dam may act as a physical barrier that can
                                               The PG&E announced in 1984 that the Helms Pumped-Storage Project the largest hydroelectric plant in                                             be ultimately destructive to a species population.
                                           its 65-plant hydro system, had begun Commercial operatiors. Located about 50 miles east of Fresno, California,
                                           the plant produces electricity during peak hours by drawing "ter from the Courtright Reservoir. Once the                                            b. Pumped-Storage Projects
                                           water passes through the hydraulic-turbinegenentuir, it is released into Wishon Reservoir. The units are then
                                           reversed and the "ter is pumped back up to the Courtright Reservoir for use during the next peak period.                                                Lakes and impoundments created for pumped storage are usually much smaller than those created by
                                           Each of the three units at the Helms Project is Capable of generating 402.000 kilowatts (California Energy                                          dams. The effect on local water systems caused by the construction of a dam can be severe (Section J.2 of this
                                           Update, July 1984), and touil capacity would be approximately 1.2 million kilowatts. This makes any one of                                          appendix) and can affect total changes in the area. The pumped-storage-project changes need not be as great,
                                           the units among the largest reversible hydroelectric system in the world.                                                                           since they are physically smaller and constitute branches of local water systems.  Water in pumped-storage
                                                                                                                                                                                               system can be reused. Natural flows are required only for make-up purposes and the initial filling.
                                           2. Environmental Effects                                                                                                                            Percolation from the upper reservoir into locally surrounding land can cause land instability and water-quality
                                                                                                                                                                                               effects. The reservoirs can cause disruption of migratory-fish species. Nonmigratory species seem to survive
                                              The generation of hydroelectric power causes a varity of enviromental effects.  The following information						     in the upper reservoirs; therefore, this area can be utilized for sportfishing.
                                                                                                                                                                                                  Although each case is special-involving local characteristics of terrain, water quality and flow patterns, fish
                                           describes effects resulting from hydroelectric dams and pumped-storagi: projects.                                                                   populations, human factors, and effects on visual appearance of the countyside-the total adverse effects are
                                           a. Hydroelectric Dams                                                                                                                               less than those of the conventional hydroelectric-power plant.
                                               Construction of a dam represents an Irreversible commitment of the Land resources beneath the newly                                             3. Conclusions
                                           created like. Flooding eliminates wildlife habimt and prevents uses such as agriculture, mining, and some
                                           recireadiual actilvides. The interruption of the rtwr's flow, even if only temporarily eliminated during the                                           The major environmental effects associated with increased use of hydroelectric power include irreversible
                                           period required for the reservoir Ming, can affect the flora and fauna downstream However, with the                                                 commitment of the land and resources beneath newly constructed lakes, modification to destruction of river
                                           construction of a dam. new water-related recreational facilitits will be generated.                                                                 or streamflow pattens below the dam, and changes in the ecology of the floodplain below the dam.
                                               Changes to the horologic system resulting from the construction and operation of a hydroelectric dam are
                                           physical but can directly and indirectly bring about changes in all the dependent biological and human systems.                                     L. NUCLEAR POWER
                                               With the construction of a dam. the relative stabilization of the water level in the basin would affect the
                                           volume of discharge and current velocity downstream. thereby affecting the energy flow of the ecosystem.
                                           Increased input to ground-water supplies could result in possille benefits to distant aquifers. In comparison                                       1. Background Considerations
                                           to the previous riverine ecosystem, reduction in turbidity through settling of sediments and possibly from the
                                           reduction of erosion in the new take could resulL Furthermore, probable reduction Of turbidity downstream                                                Commercial use of nuclear fission as an energy source has a history of less than 30 years.  This first
                                           may also mflect settling (basin action) of the reservoir, in addition to benefits of stabilized water flow through                                  electric-power-generating plant went into operation at Shippingport, Pennsylvania, in 1957.  At the present
                                                                                                                                                                                               time, there are 110 operable nuclear-power-generating plants in the U.S. Although nuclear energy is an
 


















                                           altemative-energy source, delays and cancellation of plants have occurred. Since the incident at Three-Mile                                                 2. Environmental Effects
                                           Island occurred, it has been argued that nuclear-poer pistils are unsafe and uncronomical.
                                                Ile two main "a of nuclear reactors include light-water mactors-.hich are widely used in the U.S.                                                           In addition to numerous land use and ecological effects associated with the coftstmctionofa nuclear-power
                                           breeder reactors, and gas-cooled reactors-which are used in the United Kingdom. Ught-water reactors include                                                 plant, them am environmental effects that may result from the utilization of nuclear energy. Them include
                                           two types-the boiling-water reactors and pressurized-water reactors. The fuel in both is usually slightly                                                   thermal pollution of cooling water, leakage of radiation into water and air. production and transport of the fuel
                                           enriched uranium in the form of oxide pellets contained in stainiesa-steel and zircaloy tubes. Water is used as                                             to the use site, radioacLive-waste management including transportation and storage or disposal, and the
                                           both coolant and moderator.                                                                                                                                 potential for a catastrophic nuckar-reactor accident.
                                                In the boding,water reactor, the ODO&g..ater bods in the core, and the steam generated is used directly                                                     Nuclear plants am essentially the mine cooling Process as, fossil-fueled plants and, thus, sham the problem
                                           to drive a steam turbine, thereby driving a generator. The steam is then condensed to water and pumped back                                                 of heat dissipation from cDoling@water. However, nuclear plants obtain 33-percent conversion to electricity with
                                           to the reactor to complete the cycle. Thus, the reactor acts as the boder in the process.                                                                   all the remaining 67 percent going to the cooling water. thereby requiring larger amounts ofoooling water and
                                                In the pressurized-water reactors, the core4mling water is kept at a very high pressure and is heated to
                                           600-C. The water is then sent to a separate hut exchanger, where a seciondarywater supply is boiled and =it                                                 discharging greater amounts of waste heat to the water than comparably sized fossil-fuel plants. Incomparison,
                                           to drive the turbines.                                                                                                                                      per anitofelectric energy generated, modem fossil-fucl plants contribute 1.2 units of aquatic-LIterrital poUuuon,
                                                                                                                                                                                                       while nuclear plants contribute 2.0 units.
                                                Tte problem with the boiling-water-M)e reactor is that the cooling water becomes radioactive from slight                                                    Thermal pollution causes damp by upsetting or modifying aquatic ecosystems. Thermal pollution can
                                           leaks in the thin claddingof the fuel rods and/or radioactively induced by the neutrons just outside the cladding.                                          dismpt an ecosystem in a variety of ways: (a) large temperature increases that' can kill many aquatic species;
                                           The radioactive steam goes directly to the turbines, so great care must be exercised to avoid steam leaks in the                                            (b) reduction of available oxygen (a temperature increases. solubility of oxygen decreiises); (c) alteration of
                                           turbine. This problem is avoided in the pressurized@water-rcactor system, because the cooling water and the                                                 the rate of biological activity ji.e., rapid growth ofalgae or pond weeds); (ill reductionof resistance to diseases;
                                           steam for driving the turbines are separate.                                                                                                                (e) alteration of behavior patterns; and (f) providing a competitive advantage to species that can tolerate
                                                McMullan et al. (1983) report that there are two main criticism of light- -ter-moderated reactors. First.                                              temperature changes.
                                           it is alleged that the technologyof welding the very heavy steel sheets of the pressure vesmLs is not capable                                                    Increased concern has been raised regarding the potential danger of radiation leakage. Whenanorganism
                                           of providing the necessary reliability. This is important due to the potential catastrophe that would ooc,ur if                                             sustains a large dose of radiation, acute somatic damage can result. Radiation can cause faial damage to a
                                           the pressure vessel ruptured. Second, there are the possible effects of a sudden failure in the water supply to                                             large number of cells, resulting in sickness (nausca, vomiting, headaches, weakness. and sometimes death)
                                           the core; if this occurred. the large mass of fuel and radioactive-fission products could become so hot as to
                                           cause a meltdown. From a meltdown. radioactive containment could possibly infiltrate the ground-wa(er supply                                                and delayed somatic damage -hen an organism receives a dose of radiation that is not fatal. Cells that are
                                                                                                                                                                                                       lethally damaged by the dose will not reproduce and will be eliminated. Cells that are nonlethally damaged
                                           and become a hazard.                                                                                                                                        will stay with the organism and may Later caum malfunctions (cancer, cataracts, prenatal abnormalities, and
                                                In breeder reactors, neuLromam captured by -U to form -PU. No moderator is used in the reactor core                                                    nonspecific shortening of lifespan). Genetic damage may result where a reproductive =11 is nonlethally
                                           to slow the neutrons down; as a result, the neutrons arc captured by the uranium. From this reaction, the                                                   affected, and this may give rise to a genetically defective offspring.
                                           reactor produces significant quantities of plutonium.                                                                                                            While effects associated with an accident in a nuclear-power plant am serious, a more long-term effect can
                                                The breeder reactor has some unpleasant characteristics that am regarded by its critics as rendering it                                                result due to the storage problem associated with the waste products from power generation. Low-level
                                           unacceptable for generating cleatric power. The first of them is that plutonium is highly toxic@ It also has a                                              radioactive wastes from normal operation of a nuclear plant most be collected, placed in protective wntainem.
                                           very low thermal conductivity that adds to the difficulty of extracting the heat from the reactor core. Further,
                                           there is no moderator. The core runs at a very-high-energy density and must be cooled, not by water or by                                                   and shipped to a federally licensed storage site and buried. High-level wastes created within the fuel elements
                                           a gas, but by a liquid metal-sodium. Therefore, the sodium must reach extremely high speeds in the tightly                                                  remain there until the ftiel elements are processed. Them exists a potential for radioactive leakage during
                                           packed core in order to remove the heat that is generated. Failure to remove the heat would lead to a                                                       transportation activities or a=WcntL
                                           situation that could cause a meltdown, if left uncorrected.                                                                                                      Low-level radioactive solid wastes are buried in near-surface trenches at specific sites where topography,
                                                Sodium macts explosively with water. In the breeder reactor, the sodium is pumped around the reactor                                                   meteorology, and hydrokillyare such that migration of radioactivity is not anticipated. Low-level waste from
                                           cure at an elevated temperature; after a while, the coolant becomes radioactive. Any rupture or leak in the                                                 a 1,000-mepwart plant and the fuci-cycle activity attributed to the plant require about 2.0 acres of land per
                                           cooling system would muse an extremely violent maction.                                                                                                     year.
                                                Another major criticism of the breeder reactor is that it uses plutonium in its fuel. The fuel rods are                                                     High-levellwastes are currentlystoried as liquids in tanks, although storage in bedded-salt formations deep
                                           enriched in -PIJ, which can be used as fuel for a nuclear bomb. However, it is likely that any country with                                                 underground has been suggested. Spent fuel is currently stored at facilities licensed by Elie Nuclear Regulatory
                                           the capability to build and operate a series of nuclear-power facilities on a commercial scale also will have the                                           Commission. Plans call for recovering unused fuels at reprocessing plants. solidifying the "stes, and placing
                                                                                                                                                                                                       them in stomp at Federal repositories.
                                           capability to construcathe rather Was complex facilities needed to prepare fimile materials for nuclearweapons.                                                  The effects associated with the mining and milling of uranium om are similar to those for coal mining
                                                Most failures of commercial reactors haw been minor in nature except for the incidents at Three-Mile                                                   (Section C of this appendix), with the exception of radioactive tailings and "ter being produced.
                                           Island and Chernobyl, U.S.S.R., which indicate the potential dangers of nuclear-power generation. Since the
                                           Thme-Mile-Islamd incident occurred, them has been a Large increase in public concern for the safety of them
                                           power plants. Attempits have been made to stop all future construction and shut do" all existing nuclear                                                    3. Conclusions
                                           plants in some amas. Yet dependence on this power source tends to preclude total shutdown, because no
                                           suitable alternative is available.                                                                                                                               The major enviromentaleffects associated with expanded use ofauclear energy include the need to mine,
                                                                                                                                                                                                       process, and use radiciactin materials that would result in the release of small amounts of radiation; disposal
                                                                                                                                                                                                       of the heated coolingwater, difficulties associated with selecting and usinga suitable disposialsite for spent fuel;
                                                                                                                                                                                                       and considerable public concern about possible accidents.





M. CONSERVATION

1. Background Considerations


	This section briefly addresses reducing energy consumption through a variety of improvements in the
energy efficiency of each of the five energy-consuming sectors of the U.S. economy-transportation, residential,
commercial, industrial, and transformation. Over the past decade, projections of future energy consumption
by the U.S. have changed dreamatically as a result of much higher world energy prices. A decade ago,
projections of U.S. energy consumption in the year 2000 ranged from 150 to 175 quads. The NEPP's 1985
projections of energy consumption in the year 2000 range form a low of 88.8 quads in the high
U.S. energy efficiency case, to a high of 104.8 quads in the high U.S. energy supply case, with the reference case
at 98.6 quads. (The 1985 NEPP was prepared before the rapid decline of world oil prices in 1986, If lower
world oil prices persist, future U.S. energy consumption will increase in response to both lower prices and
higher world economic wealth. Nevertheless, projections of future U.S energy consumption include substantil
improvements i the efficiency with which energy is used in the U.S. economy.) Table D-7 provides a
comparison of the projected energy consumption for each sector under the assumptions of both the 
NEPP-reference case and the high U.S. energy-efficiency case.
	The NEPP reference case includes future improvements in energy conservation that are both
technologically expected and economically efficient. Future energy consumption is projected for each sector
using the energy conservation improvements that are either already available or expected, given anticipated
technological improvements. The rate at which these energy-conservation improvements enter in the 
NEPP reference case is determined by consumer preferences under projected future energy prices. Projected
improvements in energy efficiencey play a major role in the projected future energy consumption by each sector
of the U.S. economy.

	Within each of the five categories of energy use, the demand for energy services is the result of two
typically offsetting trends- and upward trend caused by population and economic growth, and a downword trend
caused by increased effciency in the use of energy stimulated by higher energy prices. Brief summaries of the
expected energy consevation for each sector, which are abstracted from the 1985 NEPPP reference case are
presented below.
	In the residential sector, energy is consumed for space conditioning, lighting, and operating applicances.
Total energy use in this sector is dependent on the total number of households and the energy consumed by
each.  The Census Bureau estimated that, between 1984 abd 2010 (the projection period for the 1985 NEPPP),
the number of housing units will increase by 30 percent. The estimated 1984 average end use efficiency for
the residential sector was 72 percent. The rate of energy efficiency improvements is projected to be 14 percent
over the 1984-to-2010 period. Thus, the set result under the assumptions of the NEPPP reference case is a 
gradual increase in total residential energy consumption.
	In the commercial sector, energy also is consumed for space conditioning, lighting, and operating
appliances. Since 1970- apparently in response to the energy price increases of the last
decade commercial energy ise per square foot has been declining at a little less than 2 percent per year.  The
estimated 1984 average end use efficiency of the commercial setor equipment was 81 percent. The pattern
of increased energy efficiency in the commercial sector is expected to continue through the projection period.
The net result may be a leveling off in the commercial sector energy payments per square foot despite the
projected increase is energy prices.
	The industrial sector consumes energy  resources for space conditioning, lighting, operating machinery, and
feedstocks used to manufacture certain products. In response to the energy price increases of the 1970's, the
decline in energy use per unit of industrial ourput accelerated from 2 percent per year to 4 percent per year.
It is likely that the rate of energy efficiency improvements has peaked and, therefore, that an average
improveent of 2 percent per year is used in the projections.  Decreaded energy use per unit of output is
projected to result from improved process effciency and a change in the product mix being produced, with
energy intensive productions decreasing as a share of the total.

Motor vehicles (cars and trucks) use the largest share of energy consumed- about 75 percent- to transport
people and goods. About one fourth of the energy consumed in the transportation sector is used in the 
operation of pipeline, air, rail, and marine transportation. Because of improvements in both the design and
mechanics of motor vehicles, it is estimated that the actual road miles per gallon (mpg) for the entire fleet
of motor vehicles has increased by as much as 85 percent since the early 1970's. (The actual road mpg for the
entire fleet of cars and trucks should not be confused with the USEPA's estimated mpg for new cars.) The
85 percent improvement is the actual road mpg represents less than a 2 mpg improvemtne for the entire fleet
of cars and trucks to its persent level of around 15 mpg. Improvements in the energy efficiecy of the total
U.S. fleet are expected to plateau at around 23 mpg toward the end of the projection periond. However, the
average fleet road mpg will continue to increase beyond 2010.
	The two energy transformation sector industries are electric utilities and synthetic fuels. Large energy
losses are unavoidable in these industries. In terms of energy actually delviered to the end use sectors, the
utility industry has been, for at least the last 20 years, and is expected to continue to be around 32 percent
efficient.  This is not to say that little has changed or will change in the uitlity industry. In the 1960's coal and
hydro facilities lost share to oil and natural gas. In the 1970's, this movemtne reversed; and oil and gas lost
share to coal and newly completed nuclear facilites. This trend is expected to continue through the year 2000.
See the sections of this appendix that address coal and nuclear and synthetic fuels for futher discussion of 
these trends.
	The high energy efficiency case in the 1985 NEPPP used assumptions that generate a 10 percent
improvement in the overall end use efficiency in the year 2000 by comparison to the reference case. The
efficiency assumptions that were changed to generate this improvement include the consumer discount rate,
the energy demand per unit of industrial output, and the fuel efficiency of each transportation mode. Perhaps
the most important factor is the assumde change in the discount rate that consumers use in deciding to 
purchase higher efficiency equipment like furnaces, air conditioners, and insulation. (By assuming a lower
discount rate for consumer decisions, the economic attractiveness of energy efficient investments is improved.)
Further, the high energy efficiency case decreased the energy use per unit of industrial output such that energy
use was 50 percent lower than in the reference case. The higher fuel efficiency assumptions for the
transportation sector increased actual road mpg 10 to 12 percent over those used in the reference case. (See
Table D-7 for the full sector by sector comparisons and the changes in total energy consumption over the
projecton period.)
	Five major types of conservation options are often proposed as substitutes for a wide variety of
energy developemtn projects: (a) improved gas milegage performance. (b) greater use of mass transit, (c)
improved energy efficiency of household appliances, (d) higher energy conservation. The proposals to
commercial sectors, and (e) augments publ8ic and private research in energy conservation. The proposals to
use conservation rather than to develop an energy resource typically start with an observation of histroical
improvement in the efficiency of energy use in the U.S. and other economies. They then assume a specific
rate or amount of future improvement and calculate energy savings via the difference between present use
rates and the assumed future use rates. All such proposals should be examined against the information
provided above concerning projections of future gains in U.S. energy efficiency. Very considerable futher
improvements in energy efficiency are part of the expectations built into the projections of future energy
consumption. Thus, much of the calculated energy savings or conservation assumed for each of the five major
energy conservation options are already counted.
	Nearly all energy conservation policies can be classified in one of five broad categories prices, supply
restriction/allocation, regulation, incentives, and information.
	Price: Energy consumtion would be cut by relying on consumers reaction to higher prices, either for
petroleum or for all forms of energy.
	Supply Restricion/Allocation: In order to reduce energy consumption, energy supplies would be restricted
to a fixed level. Then, employing some noamarket allocation or rationing scheme, the limited supply world
be distributed amound competing uses or users.
	Regulation: Regulations could be developed that would place restrictions on how energe could be used
and would outlaw those used or technologies throught by lawmakers to be the most wasteful.












                                                    Incentives. Incentives, usually monetary, can be developed for energy-saying form of production and                                                           N. COMBINATION OF ALTERNATIVES
                                               consumption. On the other hand, disincentives, such as taxes, could be used to discourage specific kinds of
                                               waste.                                                                                                                                                               A combination of some of the most viable energy sources available to this area (discussed above) could
                                                    Information: Programs would be developed to change consumers habits of energy use, either by exhorting                                                      be utilized to attain an energy equivalent comparable to the estimated production within the anticipated field
                                               them to change their lifestyles or by pointing out the economics and other advantages of particular                                                              life of this proposed action. However, in order to attain the needed energy mix peculiar to the infrastructure
                                               energy-saying practices.                                                                                                                                         of this area, this combination of alternatives would have to consist of energy sources--attainable now or within
                                                                                                                                                                                                                the suggested timeframe-that are transferable to the technology presently used.  Viable substitutes would have
                                                                                                                                                                                                                to be available for the petroleum and natural gas required by the petrochemical-industrial complex the
                                               2. Environmental Effects                                                                                                                                         petroleum used for the transportation sector, and the electricity and fuels used in residential and commerical
                                                    The reduced production and consumption of energy resources associated with various energy-conservation                                                      sectors.
                                               proposals generates much of the public appeal for these proposals.  Simply by learning to use less energy,                                                       Allowing favorable technologies economies, the most viable domestically available energy alternatives
                                               which appears to have neither cost not environmental effects, the adverse environmental effects caused by							                would probably consist of the use of coal, oil shale, tar sands, and biomass to produce synthetic liquids; nuclear
                                              																					                                        energy and coal to compete for the utility market; and renewables to supply a sizable portion of total energy
							     																											    requirements.  The environmental effects of each of these alternatives have been discussed briefly in the
                                               production and use of the energy resources conserved will be avoided or reduced.  Potential energy savings                                                       
                                               through conservation methods would result in reduction of the environmental effects associated with energy                                                       previous sections. The result will be a long-term energy-supply transition from crude oil to alternative-energy
                                               production and use.                                                                                                                                              sources and less dependence on oil imports. Such patterns will require new and efficient technologies, major
                                                    This summary of the environmental effects of energy conservation separates possible future energy                                                           capital investments, and a high rate of growth in coal production.
                                               conservation into two parts. The first is the energy conservation that is expected to occur as a result of                                                            The future U.S. energy-source mix will depend on a multiplicity of factors-the identification of resources,
                                               improved technology in response to future energy prices. This part is included in the 1985 NEPPP-reference                                                       research-and-development efforts, development of technology, rate of economic growt, economic climate,  
                                               case, and it is called "expected conservation" in this summary of environmental effects. The second part of                                                      changes in lifestyle and priorities, capital-investment decisions, energy prices, world oil prices,
                                               possible future energy conservation includes all additional energy censervation that could result from changes                                                   environmental-quality priorities, government policies, and availability of imports.
                                               in government policies. (These possible policy changes are summarized at the end of Section M.1 in this                                                               It is unlikely that there will ever be a single definitive choice among energy sources, or that development
                                               appendex.) This part of possible future energy conservation is called "additional conservation" in this summary                                                  of one source will preclude development of others. Different energy sources will differ in their rate of
                                               of environmental effects.														                                                    development and the extent of their contribution to total U.S. energy supplies.  Understanding of the extent
                                                    The environmental effects associated with the expected part of possible future energy conservation are                                                      to which they may replace or complement offshore oil and gas requires reference to the total National energy                                              
							     wholly beneficial. The reductions in energy consumption in the four energy end-use sectors expected to occur                                                     picture. Relevant factors are:
                                               under the assumptions of the NEPPP-reference case will mean that fewer pollutants associated with energy use
                                               will be emitted.                                                        													                       - Historical relationships indicate that energy requirements will grow in proportion to the
                                                    The environmental effects associated with the additional part of possible future energy conservation are                                                             gross National product.
                                               primarily berieficial. The reductions in future energy use that could result from changes in government policies
                                               would further reduce the levels of pollutants associated with energy use.                                                                                                 Energy requirements can be constrained to some degree through the price mechanisms in
                                                                                                                                                                                                                         a free market or by more direct constraints. One important type of direct constraints that
                                                    There are, however, costs associated with the additional conservation scenario. Energy-conservation                                                                                                                            
                                               improvements that are mandated by government programs rather than in response to consumer preferences                                                                     operates to reduce energy requirements is the substitution of capital investment in lieu
                                               reduce the total value of the Nation's goods and services and thus reduce National income. Such reductions                                                                of energy, e.g., insulation to save fuel. Other potentials for lower energy use have more
                                               are a form of adverse effect on the quality of the human environment.                                                                                                     far-reaching effects and may be long-range in their implementation-they include rationing,
                                                    Conserving energy resources under government-poilicy changes could require considerable investments in                                                               altered transportation modes, and major changes in living conditions and lifestyles.  Even
                                               new or retrofitted equipment. There are environmental effects associated with production of the capital goods                                                             severe constraints on energy use can be expected only to slow, not halt, the growth in
                                               needed for most energy-conservation options. For example, production of the more fuel-efficient boilers used                                                              energy requirements within the timeframe of this statement.
                                               in retrofitting existing commercial and industrial buddings would generate a variety of adverse environmental
                                               effects that otherwise would not occur. Similarly, in order in render existing buildings more energy-efficient,                                                           Energy sources are not completely interchangeable. For example, solid fuels cannot be
                                               materials whose production entails adverse environmental effects may be used.                                                                                             used directly in internal-combustion engines. Fuel-conversion potentials are severely
                                                                                                                                                                                                                         limited in the short term, although somewhat greater flexibility exists in the longer term
                                               3. Conclusions                                                                                                                                                            and generally involves choices in energy consuming capital goods.
                                                    Reduction of the environmental effects associated with production and consumption of energy resources                                                                The principal competitive interface between fuels is in electric-power plants.   Moreover,                                               is one of the primary advantages of energy-conservation measures. However, the investments and programs                                                                         the full range of flexibility in energy use is limited by environment
                                               often associated with improved energy efficiency generate environmental effects. Thus, energy-conservation											 the full range of flexiblity in energy use is limited by environmental considerations.
                                               options are not void of environmental effects.
 





















                                                                                                                                                      Table D-7

                                                                                                                  Comparison of NEPPP-Referenoe and High-Evergy-EfficienLy Cases
                                                                                                                                                      (Quads)


                                                                                                                                                         Energy Used by Final Consumers
                                                                                                                                                      Excluding Inputs to Utilities and Syniheiies
                                                                               Energy
                                                            Total              Loses
                                                            Energy          Transfor-                                                Coal                             Renew-                                                 Com-                               Trans-
                                       Year                 to U.S.            mation           Liquids           Gases              Solids           Electricity       able,        Total             Residential         mercial         Industrial        portanion

                                       Estimate
                                       1994                 76.6               -18.0            29.6              15.2               M                7.8               2.8          58.8                  9.9               6.1              22.6               19.8

                                       Projected

                                       1990
                                       Ref. Case            87.3               -22.1            32.3              16.7               3.8              9.1               3.3          65.2                  10.8              7.2              28.2               19.2
                                       High Effic.          81.6               -20.6            30.6              15.3               3.5              8.5               3.1          6.0                   9.7               6.7              26.2
                                                                                                                                                                                                                                                                 18.5
                                       1995
                                       Ref. Case            93.1               -25.2            32.3              17.5               3.7              10.3              4.0          67.9                  11.2              7.8              29.6               19.4
                                       High Effic@          95.4               -23.3            30.0              15.5               3.3              9.5               3.7          62.1                  9.7               7.2              27.0               18.4

                                       2000
                                       Ref. Case            98.6               -28.0            32.9              17.4               3.9              11.5              4.8          70.6                  11.3              8.4              30.4               20.7
                                       High Effic.          8&8                -25.6            30.0              15.0               3.4              10.5              4.3          63.3                  9.6               7.7              27.0               19.2

                                       2OU5
                                       Ref. Case            104.2              -30.9            32.9              17.2               4.6              12.8              5.8          73.3                  11.3              8.8              31.9               21.4
                                       High Effic.          92-7               -28.0            29.6              14.5               3.9              11.5              5.3          64.8                  9.4               8.0              27.7               19.7

                                       2010
                                       Ref. Case            110.8              -34.5            33.0              16.8               5.4              14.3              6.9          76.3                  11.2              9.4              33.5               22.3
                                       High Effic.          97.9               -31.0            29.4              13.9               4.4              12.8              6.3          66.8                  9.5               8.6              28.4               20.4

                                       'Renewable central electric is included in electric column

                                       Source: U.S. Department of Energy, National Energy Policy Plan Projections to 2010, December 1985.















                                                                                                                                                                                                                                                                                                                              00




                                                                                                                                                                                                                                              Table D-8

                                                                                                                                                                                                                                   Replacement Energy Needs
                                             Regulation of oil and gas prices lowered the price below the product level that ferMCFS                                                                                          Central and Western Planning Areas
                                             (and consumers) paid for domestic Oil and prevented the incremental cost of all domestic
                                             producing fields from equaling to the price of imports. This impaired the econom3es                                                                                                              (Base Case)
                                             ability to adjust to world energy prices. Under deregulation, the neat prices of oil and gas
                                             will be closer to the marginal costs of altemathe energy.                                                                                                                                                Central Gulf             Western Gulf
                                             A broad spectrum of research and development is being directed toward energy                                                                                                                               Sale 142                  Sale 143
                                             conversion-more efficient nuclear reactors, coal gasifkation and liquefaction, liquefied                                                 Btu equivalents: *(trillion Btu)
                                             =rural gas, and shale retorting, among others.                                                                                                       Oil -    0.14 billion barrels                             784.0
                                      Several of these factors could assume important roles in supplying future energy requirements, although                                                              0.05 billion barrels                                                       280.0
                                 their future competitive relationship is not yet predictable.                                                                                                    Gas -    1.40 trillion cubic feet                         1,429.4
                                                                                                                                                                                                           0.74 trillion cubic feet                                                   755.5
                                                                                                                                                                                      Oil equivalents:     '(billion barrels)
                                                                                                                                                                                                  Oil from other sources needed to directly
                                                                                                                                                                                                  replace expected Oil Production                              0.14                     0.05
                                                                                                                                                                                                  Oil from other sources needed to replace
                                                                                                                                                                                                  expected gas production                                      0.255                    0.135
                                                                                                                                                                                      Gas equivalents: '(trillion cubic feet)
                                                                                                                                                                                                  Gas from Other sources needed to replace
                                                                                                                                                                                                  expected Oil production                                      0.768                    0.274
                                                                                                                                                                                                  Gas from other sources needed to directly
                                                                                                                                                                                                  -place expected gas production                               1.40                     0.74
                                                                                                                                                                                      Coal equivalents: *(billion short tons)                                  0.097                    0.043
                                                                                                                                                                                      Electrical equivalents: *(billion kilowatt/hour)
                                                                                                                                                                                                  Substitutes for end uses-                                 337.3                     157.8
                                                                                                                                                                                                  Substitutes for input
                                                                                                                                                                                                  to electricity generation...                              207.6                     97.1


                                                                                                                                                                                      Notes:      *Conversion factor used:
                                                                                                                                                                                                     1 barrel of oil = 5.6 x 106 Btu.
                                                                                                                                                                                                     I cubic foot of natural gas = 1,021 Btu.
                                                                                                                                                                                                     I short ton of bituminous coal - 24 x 106 Btu.
                                                                                                                                                                                                     I kilowatt hour - 3,412 Btu at the thcOfetkal conversion rate of other energy forms of
                                                                                                                                                                                                     electricity at 100% efficiency.
                                                                                                                                                                                                     'Based on a 65% average efficiency of end use of oil and gas (such as oil and gas heating) and
                                                                                                                                                                                                     a Plant load factor of 80%.
                                                                                                                                                                                                  -Efficiency of fossil fuel elp,-t,jj,v
                                                                                                                                                                                                     equals 80%.                            1 ------                                      I Ile plant ioad factors
                                                                                                                                                                                      Source: USDOI, Minerals Management Service, Gulf of Mexico OCS Region, IM.












                                                                     Appendix E



                                                      Recent Mitigating Measures













          tsT Or
                                                                                TAKEN@@=
                      United States Department of the Interior                              E-3

                                  MINERALS MANAGEMENT SERVICE
            Ich 31.                 GULF OF MEXICO OCS REGION
                                  1201 ELMWOOD PARK BOULEVARD
                                 NEW ORLEANS, LOUISIANA 70123-2394


            In Reply Refer To: MS 5221                                    November 20, 1990










            Gentlemen:


            Recent questions and concerns have been raised regarding the disposal of
            solids removed from production vessels located on the Outer Continental Shelf.
            Many of these concerns are related to the disposal of solid accumulations
            which contain naturally occurring radioactive materials (NORM).

            In accordance with 30 CFR 250.40(b)(2), approval of the method of disposal
            of drill cuttings, sand, and other well solids shall be obtained from the
            appropriate district supervisor. Due to the Increasing concerns and
            occurrence of NORM, the Minerals Management Service regional office is
            directing more attention to the approval and discharge of all solids.
            Therefore, operators planning to remove solid accumulations from production
            vessels and/or flow lines or tubing must now submit a full description of
            the method that will be used in the removal and disposal. of these so2ids.
            Approval must be received from the regional office prior to the diocharge or
            disposal of any such materials. Radioactive readings must be recorded and the
            results submitted on all solid materials. Any filtered wash water involved in
            the removal of produced sand and pipe scale that has a radioactivity le-vel at
            or below that of produced water may be disposed overboard in accordance witi,
            the conditions of your NPDES permit.

                                                   Sincerely,




                                                   D. J. Bour6ois
                                                   Regional Supervisor
                                                   Field Operations







                       United States Department of the Interior                             E-5

                                   MINERALS MANAGEMENT SERVICE
                                     GULF OF MEXICO OCS REGION
             ,A 3.
                                   1201 ELMWOOD PARK BOULEVARD
                                  NEW ORLEANS, LOUISIANA 70123-2394
            In Reply Refer To: MS 5221                               DEC 11 1991









            Gentlemen:


            The purpose of this letter is to provide clarification of our Letter to
            Lessees and Operators (LTL) dated November 20, 1990, concerning the removal
            and disposal of well solids produced from Gulf of Mexico (GOM) OCS Region
            lease operations; specifically, those solids containing natural occurring
            radioactive material (NORM). This letter will also serve to establish interim
            guidelines for the reporting, disposal, and transportation of produced well
            solids until the data collected during the interim period is evaluated and
            formal policy can be promulgated.

            In accordance with the November 20, 1990, LTL, approval of methods for
            disposal of drill cuttings, sand, scales, and other well solids is handled
            by the GOM OCS Regional Office. Only well solids produced from GOM OCS Region
            lease operations may be approved for disposal. It has been determined that
            the information available concerning the occurrence of these solids has not
            been sufficiently addressed. Accordingly, the interim guidelines contained
            herein were devised to closely monitor the disposal of well solids containing
            NORM and assist in the collection of data pertinent to the establishment of
            regulations necessary for disposal of this material.

            The following will provide the GOM OCS Region application of the provisions
            of 30 CFR 250.40(b)(2):


            I. DISPOSAL CRITERIA


            Overboard Discharge of Produced Well Solids

            The operator must submit an application for each facility where overboard
            discharge is proposed. Overboard discharges may be approved based on the
            following criteria:

                 1. The discharge site is not in close proximity to a biologically
            sensitive area.


                 2. Adherence to the Environmental Protection Agency (EPA) discharge
            requirements outlined in the National Pollutant Discharge Elimination System
            (NPDES) general permit.











            E-6
                                                                                          2

                 3. A representative I-liter sample of the material to be discharged
           must  be acquired and analyzed for radiation dose equivalent rate. Based on
           this  analysis, the material must demonstrate a radiation dose equivalent rate
           of no greater than 25 microroentgens per hour above background.

                 4. The volume of well solids to be discharged cannot exceed 100 barrels
           per day. However, more stringent volume constraints may be required at time
           of application approval depending upon water depth, location, current, and
           other such parameters.

                 5. The sample(s) described in Item 3 for each discharge during each
           3-month period in which discharges occur must be stored as a composite, mixed,
           and subsampled. These subsamples must be analyzed by a laboratory capable of
           supplying accurate results for concentrations of Radium 226 and Radium 228.
           Records concerning these data, tests, and details such as discharge dates,
           volume discharged, and radiation dose equivalent rates must be maintained and
           made available for review by this office upon request.

                 6. Based on the data provided in Item 5, a quarterly calculation must
           be made to determine the total radium discharged to date. Should the total
           radium discharged surpass 50,000 microcuries this office must be notified
           and all future discharges stopped until an assessment of the area is
           completed. More stringent total radium constraints may be imposed at time of
           application approval depending upon water depth, location, and oceanographic
           conditions.


           Discharge of Well Solids Encountered Durinz Workover Operations

           During well workover operations, solids recovered may be discharged without
           prior approval if the following criteria are met:

                 1. Adherence to the EPA discharge requirements as outlined in the NPDES
           general permit.

                 2. Approval is obtained from the appropriate District Supervisor for
           the workover operation. Disposal procedures must be specified in the sundry
           notice if there is a possibility that produced solids will be recovered.

                 3. A minimum of two representative 1-liter samples are acquired and
           analyzed for radiation dose equivalent rate. Based on this analysis the
           material must have a rate of no greater than 5 microroentgens per hour above
           background.

                 4. A detailed report concerning the discharge is submitted to the
           appropriate District Supervisor with the subsequent sundry notice. This
           report should include the lease number(s), well, area, block, date(s) of
           discharge, volume, description of the material, and dose rate measured.

           Specific approval must be obtained from this office for the discharge of
                                                                                    D
           produced well solids encountered during workover operations which do not
           meet the previously-described criteria.











                                                                                       E-7
                                                                                     3

           Alternative Methods of DisRosal

           If onshore disposal/storage is proposed or the material is unsuitable for
           overboard discharge, this material may be transported to shore for subsequent
           storage and/or disposal without prior approval from this office. All
           associated activities must adhere to applicable federal and state guidelines
           concerning the transportation, storage, and ultimate disposal of NORM.
           Documentation detailing the volume, activity level, facility of origin, and
           final destination must be submitted to the Regional Supervisor within seven
           days of such disposal from OCS facilities.

           Other DisRosal Methods

           The overboard discharge of produced well solids having a dose equivalent
           rate of greater than 25 microroentgens per hour above background will be
           considered by this office on a case-by-case basis following the submittal
           of an application containing information such as, but not limited to, the
           dose equivalent rates, radioactive isotope concentrations, total radium,
           discharge modeLing, location, and oceanographic conditions.

           All other disposal alternatives such as downhole injection, encapsulation,
           or offshore storage will require prior approval. These disposal methods
           may be approved by the Regional Director based upon the submittal of
           environmental, geological, and operational data which demonstrate that the
           operation is safe and environmentally sound.

           II. APPLICATION REQUIREMENTS

           Overboard Discharge of Produced Well Solids

           The application for overboard discharge of produced well solids from a
           facility should include:

                1. Identification of the platform from which the discharge will occur
           including water depth and oceanographic conditions.

                2. If applicable, a listing of other facilities from which solids were
           generated that will be transported to the discharge site for processing and
           discharge.

                3. Expected frequency and volume of materials to be discharged.

                4.  Preliminary activity measurements.

                5.  Proposed program for monitoring, sampling, and recordkeeping.

                6.  Description and characterization of material to be discharged.

                7.  Method of discharge (i.e., at surface).








          E-8                                                                       4


          Alternative Methods of Disposal

          As discussed previously, disposal options not meeting the criteria for
          overboard discharge or other approved methods will require an extensive
          geological, operational, and environmental review. Therefore, all data
          pertinent to the proposed operation should be submitted with the application
          to expedite its evaluation. Some proposals may require a detailed assessment
          and mathematical modeling, as well as other information, such as the radio-
          active isotope concentrations, volume, disposal site, and transportation and
          handling procedures.

          III. SAMPLING, TESTING, AND RECORDKEEPING

          Sampling and testing protocol should be performed using the best technology
          available to provide accurate results. A suggested method to obtain a
          representative sample would be to place the material in "cutting boxes," take
          at least 9 random cores that include the entire column of material, combine,
          and mix the cores in a 1-liter or larger wide-mouth high-density polyethylene
          or similar container which should be lightly packed as full as possible with
          the material to minimize any air spaces and capped. Details of the collection
          such as sample identification, date, and location should be attached to the
          container.


          It is understandable that for operations such as sand jetting the above
          procedure would be impractical. Therefore, other sampling procedures must be
          approved to ensure precautions are taken to obtain a representative 1-liter
          sample for testing during each of these operations.

          The radiation detection instruments to be used for dosage rates should
          adequately measure alpha, beta, and gamma radiations. State-of-the-art
          radiation detectors capable of properly measuring 1 microroentgen per hour
          through 500 microroentgens per hour and calibrated by a qualified person at
          intervals not to exceed 6 months should be used. The survey, calibration,
          and measurements are to be performed by trained personnel.

          All measurements should be made with the meter's sensing element in contact
          with the sample container. Measurements recorded in microroentgens per hour
          should be taken at the center of the bottom of the filled container while it
          is lying on its side. Additional measurements should be made against the
          side of the container at the longitudinal and vertical center by rotating
          the container 360 degrees, taking a measurement every 90 degrees. The
          measurements should then be averaged, documented, maintained at the site,
          and made available upon request by a representative of this office.

          For the quarterly specific activity measurements in accordance with routine
          discharge criteria, the 1-liter samples acquired as mentioned above, should
          be stored as a composite with samples from other discharges occurring within
          the 3-month sampling period, mixed, and subsampled. An analysis should then
          be performed to accurately determine the concentration of Radium 226 and
          Radium 228 expressed in picocuries per gram. The method of analysis is to
          be gamma-ray spectroscopy. A qualified laboratory should be used and results
          of laboratory quality control test recorded.







                                                                                     5 E-9

            Additionally, documentation pertaining to the transportation, storage,
            disposal method, sampling, and testing for those produced well solids which
            are transported to shore must be maintained at the field office and made
            available upon request by a representative of this office.

            These guidelines were prepared for an interim period to assist in the
            collection of data pertinent to the establishment of regulations for the
            handling of produced well solids. Therefore, your cooperation in providing
            this office with information concerning the occurrence of NORM in produced
            well solids as accurately and completely as possible is greatly appreciated
            and will expedite the preparation of appropriate regulations.

                                                 Sincerely,





                                                 D.     ourge s
                                                 Regional Supervisor
                                                 Field Operations
                                                 D. @@JMurge @s











                                                                            E-11

                         UNITED STATES DEPARTMENT OF THE INTERIOR
                                MINERALS MANAGEMENT SERVICE
                                 GULF OF MEXICO OCS REGION


            91-02                                          December 20, 1991


            NOTICE TO LESSEES AND OPERATORS OF FEDERAL OIL. GAS, SULPHUR, AND
            SALT LEASES AND PIPELINE RIGHT-OF-WAY HOLDERS IN THE OUTER
            CONTINENTAL SHELF, GULF OF MEXICO OCS REGION


            OUTER CONTINENTAL SHELF ARCHAEOLOGICAL RESOURCE REQUIREMENTS FOR
                               THE GULF OF MEXICO OCS REGION


            The Federal Government's responsibilities in archaeological
            resource management and protection on the Outer Continental Shelf
            (OCS) are based on the requirements of the National Historic
            Preservation Act of 1966, as amended, and on other applicable
            laws and regulations. The Minerals Management Service (MMS) has
            issued regulations at 30 CFR 250.33(b)(15), 250.33(o),
            250.34(b)(8)(v)(A), 250.34(s), 250.157(a)(5), as well as lease
            stipulations which, if invoked, require OCS operators to conduct
            surveys and prepare reports designed to fulfill these
            archaeological resource legal responsibilities. Notices to
            Lessees and operators (NTL) Nos. 74-10 and 75-3 were issued by
            the Gulf of Mexico OCS Region (GOMR) to implement the provisions
            of the lease stipulations. on October 1, 1982, NTL No. 75-3 was
            revised 4nd issued by the GOMR to provide guidance on uniformity
            and consistency of archaeological resource field surveys and
            reports.

            In June 1987, the MMS contracted with Texas A & M University to
            update and improve a i977 historic resources study and to broaden
            the historic shipwreck database. This study was specifically
            designed to reevaluate the zone of historic shipwreck high
            probability. In November 1989, the study was completed. Based
            on the study results, the MMS has redefined the high probability
            areas for the occurrence of historic shipwrecks. This has
            resulted in a substantial reduction in the number of lease blocks
            in the Gulf of Mexico (i.e., approximately 50%) requiring a
            magnetometer survey. The study also demonstrated a compelling
            need to increase magnetometer data density in the high
            probability areas in order that historic shipwreck magnetometer
            patterns may be recognized. This shall be accomplished by
            reducing the survey linespacing interval, in the historic
            shipwreck high probability areas, from 150 meters (m) to 50 m.
            The NTL is presented as a series of enclosures. Enclosure No. 1.
            is titled Requirements for Archaeological Field surveys.
            Enclosure 2. is titled Standards for Archaeological Resource
            Reports. Enclosure No. 3. is titled Recruirements for Mitigation
            and Operational Restrictions.











         E-12
         The provisions of this NTL shall become effective as of
         February 17, 1992.
                                    - 9             -.
                                    J. Rogers Pe rcy
                                    Regional Director

         Enclosures
                                 ,@-z   Q-@@
                                               a






























































                                       2









                                     ENCLOSURE NO 1.                      E-13


           REQUIREMENTS FOR ARCHAEOLOGICAL RESOURCE FIELD SURVEYS

           I.   Introduction

           After a lease is issued the GOMR will:

                (1) Notify the operator, in writing, if the decision is
           made to invoke the archaeological resource report requirement
           portion of the stipulation.

                (2) Identify to the operator the type of report (historic,
           shipwreck, historic shipwreck/prehistoric site, or prehistoric
           site) and the standards that shall be required for compliance.

           After notification from the GOMR of the decision to invoke the
           report requirement of the stipulation, the operator shall conduct
           the appropriate high-resolution remote sensing survey to
           determine the potential existence of archaeological resources
           that may be affected by future lease operations. In most cases,
           the archaeological resource field survey requirements will be
           similar to those for surveys conducted for shallow hazards or
           other purposes. The operator is encouraged to conduct the
           surveys concurrently. Pipeline right-of-way holders are directed
           to contact the Regional Supervisor, Leasing and Environment,
           GOMR, for determination of the type of archaeological resource
           field survey and report that will be required.
           In the letter of invocation, the GOMR may request to be notified
           at least 72 hours prior to commencement of the survey so that
           arrangements can be made for observation of field procedures. An
           archaeologist and geophysicist need not be present while the
           archaeological resource field survey is being conducted, but they
           should be involved in'survey planning. The survey shall be
           conducted prior to submitting an Exploration Plan, Development
           Operations Coordination Document, or pipeline application which
           proposes bottom disturbing operations.
           When any of the following requirements cannot be met for
           technical or logistical reasons, an explanation of the problem
           shall be provided in the archaeological resource report.

           II. Data Acquisition Instrumentation

           Geophysical instrumentation for archaeological resource field
           surveys shall be representative of the state-of-the-art in
           technological development and shall be deployed in a manner which
           minimizes interference among the instrumentation systems. All
           data recorders shall be interfaced into the navigation system to
           assure proper integration of information. The equipment operator
           shall ensure that all instrumentation is adequately tuned and

                                            3










         B-14
         that all recorded data are readable, accurate, and properly
         annotated.

         The following instrumentation shall be utilized in conducting
         archaeological resource field surveys:

              A.   Magnetometer

         A magnetometer need be used only for historic shipwreck (HS) and
         historic shipwreck/prehistoric site (HS/PS) surveys. Total field
         intensity instruments shall be used to determine the possible
         presence of historic shipwrecks. Data obtained shall be of such
         quality so as to permit detection and evaluation of magnetic
         anomalies within the survey area.                               I
         The sensor of the magnetometer shall be towed as near as possible
         to the seafloor; a distance of six meters or less is required. A
         mechanical or digital depth sensor shall be attached to the
         magnetometer sensor, and each survey line shall be annotated with
         tow sensor depth and with the start of the line (SOL) and end of
         the line (EOL) times.
         Magnetometer sensitivity shall be one gamma or less, with the
         data sampling rate not to exceed one-second intervals. The use
         of the "zero-model' setting during magnetometer surveyinc i
                                                                  F is
         prohibited. This surveying mode does not measure the ambient
         magnetic field as required. Background noise level shall not
         exceed three gammas peak to peak. Analog strip chart recorders
         shall be equipped with dual trace pens. Recording scales shall
         include both 1,000-gamma and 100-gamma full scale, respectively.
         Shot points and recorder speed must be annotated on the strip
         charts for each survey line. The GOMR recommends that the strip
         chart recorder speed be approximately two inches per minute.
         Whenever possible, the magnetometer should be towed a minimum
         distance of two and one-half vessel lengths behind the vessel to
         eliminate the magnetic influence and effect of the vessel.

               B.   Dual Channel Side-Scan Sona

         A dual channel side-scan sonar system shall be used to record
         continuous planimetric images of the seafloor. The system shall
         be operated in a manner that provides 100 percent coverage of the
         seafloor in the survey area. Data obtained should be of such
         quality so as to permit detection and evaluation of seafloor
         objects and features within the survey area.
         Whenever possible, the side-scan sonar sensor shall be 'towed
         above the seafloor at a distance of 10 to 20 percent of the range
         of the instrument. The vertical sound beam width shall be
         appropriate to the water depth, and the horizontal sound beam
         width shall provide optimum resolution. Tuning should be
         accomplished in a manner that enhances the echo returns from

                                          4











                                                                         E-15
           small nearby objects and features without sacrificing the quality
           of echo returns from more distant objects and features.

                C.   Subbottom Profiler

           A subbottom profiler system shall be used to determine the
           character of near-surface geological features. Data obtained
           should be of such quality so as to permit evaluation of these
           features for determining any possible prehistoric archaeological
           significance. The system used shall be capable of providing at
           least one to two meters of resolution within the upper 15 meters
           of sediment.


                D.   Depth Sounder

           Continuous water depth measurements shall be made using a high-
           frequency narrow-beam depth sounder. Bathymetric data shall be
           recorded with a recording sweep appropriate to topography and
           water depth.

                E.   Additional Investigations

           Under certain conditions, MMS may require additional
           instrumentation and methods such as underwater television; still,
           video, or movie cameras; divers; remote or manned submersibles;
           coring; and additional geophysical survey lines. The operator
           will be notified, by letter, of such requirements at the time of
           stipulation invocation. Right-of-Way Pipeline holders are
           directed to contact the Regional Supervisor, Leasing and
           Environme'nt, to ascertain whether additional instrumentation and
           methods are required.

           III. Survey Parameters

           The following navigati'on and survey pattern requirements shall be
           adhered to when conducting archaeological resource field surveys:

                A.   Navigation

           Navigation for the survey shall be accomplished by using a state-
           of-the-art continuous positioning system correlated to annotated
           geophysical records. The system shall have an accuracy of
           5 meters or less. The nominal fix spacing shall be no more than
           152 meters.


                B.   Survey Pattern

                     1.    Lease Surveys - When multiple operations on the
           lease are planned or probable, it may be advantageous to conduct
           a lease survey. This survey shall cover the entire area of the
           lease, as well as that portion external to the lease within which
           operational activities may cause physical and/or long-term

                                            5










          E-16
          magnetic disturbances. The area of physical disturbances
          includes, but is not limited to, the area within which drilling
          vessel anchors may be placed, but does not include the area
          within which work boat anchors may be placed or the area within
          which similar minimal disturbances may occur. The survey shall
          be run along parallel primary lines spaced at a maximum of So
          meters for HS or HS/PS surveys and at a maximum of 300 meters for
         .prehistoric site (PS) surveys with cross-tie lines spaced at a
          maximum of 900 meters for each type of survey. Tighter line
          spacing may be required by the GOMR in areas of known significant
          or potentially significant archaeological resources. The
          operator will be notified by letter of such requirements at the
          time of stipulation invocation.

          Lease HS and HS/PS surveys which are conducted on lease blocks
          that have been identified by the letter of invocation as being in
          water depths greater than 60 m shall have the same survey pattern
          as lease PS surveys.

                    2.   Single Drill Site/Platform Surveys (Site Specific
          Surveys) - These surveys shall be run in an area approximately
          914 meters (3,000 feet) square centered upon the proposed drill
          site with primary lines spaced at a maximum of 50 meters for HS
          or HS/PS surveys or at a maximum of 300 meters for PS surveys
          with three equidistant cross-tie lines. Additional survey lines
          may be necessary so that the area surveyed includes the area
          within which operations may cause physical and/or long-term
          magnetic disturbances. Tighter line spacing may be required by
          the GOMR in areas of known significant or potentially significant
          archaeological resources. The area of physical disturbances
          includes, but is not limited to, the area within which drilling
          vessel anchors may be placed, but does not include the area
          within which work boat anchors may be placed or the area within
          which similar minimal disturbances may occur. Single drill
          site/platform surveys @re not required in areas where lease
          surveys have already provided sufficient archaeological coverage
          of the area.

          site-specific HS and HS/PS surveys which are conducted -on lease
          blocks that have been identified by the letter of invocation as
          being in water depths greater than 60 m shall have the same
          survey pattern as site-specific PS surveys.

                    3.   Pipeline Surveys

                         (a) Right-of-Way Pipelines - The survey pattern
          for all right-of-way pipelines shall include a line along the
          proposed pipeline route (center line) and offset parallel lines
          (on either side of the center line) spaced at a maximum of 50
          meters for HS and HS/PS surveys. For PS surveys, the survey
          shall include a line along the proposed centerline with offset
          parallel lines spaced at a maximum of 300 meters. The number of
          offset parallel lines must be sufficient to provide adequate
          survey coverage of the area within which operations may cause
          physical and/or long-term magnetic disturbances. A minimum of

                                          6










                                                                         E-17
            two offset parallel lines shall be required. The area of
            physical disturbances includes, but is not limited'to, the area
            where pipeline lay barge anchors will be placed.
            A survey for a right-of-way pipeline which will be laid in an
            area where an HS or HS/PS survey is required and will be in water
            depths greater than 60 meters shall include a center line with
            offset parallel lines spaced at a maximum of 300 meters. The
            number of offset parallel lines must be sufficient to provide
            adequate survey coverage of the area within which operations may
            cause physical and/or long-term magnetic disturbances. A minimum
            of two offset parallel lines shall be required.

                           (b) Lease-Term Pipelines - Archaeological
            resource surveys for lease-term pipelines which will be laid
            within leases that have been previously surveyed at 50 m line
            spacing interval (i.e., HS, or HS/PS) are not required. Surveys
            for lease-term pipelines which will be laid within block(s) that
            have been previously surveyed and are exclusively considered to
            have a high potential for prehistoric archaeological resources
            (i.e., PS) are also not required.

            In water depths shallower than 60 meters, surveys for lease-term
            pipelines on leases designated to have a high probability for
            historic period shipwrecks (i.e., HS, HS/PS) shall be conducted
            using the survey pattern discussed in paragraph 3(a) for right-
            of-way pipelines. Previous surveys of these leases at 150 or
            300 meter linespacing will not be adequate.
            Surveys for lease-term pipelines which will be laid within leases
            in water depths greater than 60 meters are not required.
            However, for these pipelines, an archaeological resource report
            based on'data obtained from a previous shallow hazard survey
            shall be required.























                                            7










         E-18
                                   ENCLOSURE NO. 2


                 STANDARDS FOR ARCHAEOLOGICAL RESOURCE REPORTS

         I. Introduction

         An evaluation and synthesis of data gathered during an
         archaeological resource survey shall be included in a report
         prepared and signed by an archaeologist and a geophysicist.
         Professional personnel in these fields should have credentials
         and experience sufficient to ensure that they are able to
         adequately perform the necessary work. As needed, specialists in
         other fields may participate in data analysis and report
         preparation.

         All original  data used to prepare the archaeological resource
         report shall  be maintained by the lessee or permittee and be made
         available to  the GOMR upon request at any time prior to lease
         termination or pipeline right-of-way relinquishment.
         Prior to commencing any drilling, production, or construction
         operations, the operator/applicant/permittee shall submit to the
         Regional Supervisor, Field operations, an original report and
         three (3) copies to determine the potential existence of any
         archaeological resource that may be affected by the operations.
         In the case of historic shipwreck reports, the required
         representative magnetometer data samples must be included in the
         original report and two (2) of the three (3) copies. The report
         shall be based on an assessment of the data from remote-sensing
         surveys i'n accordance with the specifications of this NTL,
         subsequent appropriate LTL's, and other pertinent archaeological
         and environmental information. Data required for shallow hazard
         surveys and platform foundation analyses shall generally be
         sufficient for PS resource reports.

         II. Contents of Archaeological Resource Reports

         Archaeological resource reports shall include the following
         information:

              A.    A description of the area surveyed including lease
         number(s), block numbers(s), OCS lease area(s), and water depths.

              B.    A listing of personnel and duties for individuals
         involved in survey planning, survey conduct, and report
         preparation.

              C.    A discussion of the archaeological resource field
         survey including the following:

                    (1) A brief description of the navigation system with
         a statement of its estimated accuracy for the area surveyed.

                                          8











                                                                        E-19
                     (2) A brief description of survey instrumentation
           including scale, sensitivity settings, sampling rate per second,
           and tow depths where required.

                     (3) A description of the survey vessel including
           vessel size, sensor configuration, navigation antenna locations,
           and cable lengths.

                     (4) Vessel speed and course changes.

                     (5) Sea state and weather conditions.

                     (6) A copy of the original daily survey operations
           log.

                     (7) A description of survey procedures including a
           statement of survey and record quality, a comparison of survey
           line crossings, and a discussion of any problems which may affect
           the ability of the report preparation personnel to determine the
           potential for archaeological resources in the survey area.

               D.    A navigation postplot map of the survey area at a scale
           of 1:12,000 showing survey lines, shot points at 152 meter
           (500 feet) intervals, line direction in the grid projection in
           which the lease is described, e.g., UTM, Lambert, TM, etc., and
           x, y grid coordinates and tics placed every five inches thereon
           with geodetic graticules every 60 seconds. This map, or separate
           maps at the same scale which also show survey lines, shot points,
           and line direction, shall be oriented to true north and shall
           delineate the following, as appropriate:

                     (1) The horizontal and vertical extent of all relict
           geomorphic features having potential for associated prehistoric
           sites. Such areas include, but are not limited to, tidal
           estuaries, embayments,'barrier islands, beach ridge sequences!
           spits, alluvial terraces, and stream channels. When relict
           fluvial systems are recorded, the map shall:

                          (a) differentiate between generations of
           channeling when more than one generation is present;

                          (b) show any internal channel features such as
           point bar deposits and terraces;

                          (c) delineate any channel margin features such as
           natural levee ridges; and

                          (d) indicate all depths of channel banks and
           channel axes.

           Note: An isopach map of channel fill sediments is often the most
           efficient means of conveying the above information, but this

                                           9










         E-20
          method alone will not allow differentiation between more than one
          generation of channeling.

                     (2) Bathymetry.

                     (3) All magnetic anomalies and seafloor side-scan
          sonar contacts of unknown source (i.e., magnetic anomaly, map
          symbol =    ; side-scan sonar contact, map symbol = (SSS). The
          duration of all magnetic anomalies shall be plotted on the survey
          map at a scale of 1:12,000.

                     (4) Sites of proposed oil and gas operations (i.e.,
          proposed well locations, platform sites, and/or pipelines), when
          available at the time of report preparation.

                     (5) Sites of former oil and gas operations (i.e.,
          abandoned well locations, platform sites, and/or pipelines).

               E.    If an analysis of the potential for prehistoric sites
          within the survey-area is required, the report shall include:

                     (1) A review of current existing literature on the
          late Pleistocene and Holocene geology, paleogeography and sea
          level change in the area, marine and coastal prehistory, and
          previous archaeological resource reports in the area, when
          available. A list of suggested references will be made available
          upon request.

                     (2) A discussion of relict geomorphic features and
          their archaeological potential to include the following:

                          (a) the type, age, and association of the
          features mapped;

                          (b) thv-a acoustic characteristics of channels and
          their fill material;

                          (c) evidence for preservation or erosion of
          channel margins;

                          (d) evidence for more than one generation of
          fluvial downcutting; and

                          (e) the sea level curves used in the assessment.

                     (3) A discussion of the potential for identification
          and evaluation of buried prehistoric sites based on the
          capabilities of current technology in relation to the thickness
          and composition of sediments overlying the area of a potential
          site.




                                           10











                                                                          E-21
                F.   If an analysis of the potential for historic shipwrecks
           within the survey area is required, the report shall include, as
           appropriate, the following:

                     (1) A current review of existing records for reported
           shipwreck locations in the survey area and adjacent areas;

                     (2) A list of the magnetic anomalies with the lease
           block and survey line location (corrected for sensor offset),
           gamma intensity, lateral extent (duration), whether the anomaly
           is characterized by a dipolar or monopolar signature, and
           magnetometer sensor tow depth of each;

                     (3) A list of side-scan sonar contacts with the leasp
           block and survey line location (corrected for sensor offset),
           size, shape, and height of protrusion above the seafloor of each;

                     (4) A discussion of any magnetic anomalies and side-
           scan sonar contacts of unknown source in terms of their potential
           as historic shipwrecks;

                     (5) A discussion of any correlation between magnetic
           anomalies or side-scan sonar contacts and known or probable
           sources;

                     (6) A discussion of the potential for shipwreck
           preservation in terms of the effects of past and present marine
           processes; and

                     (7) A discussion of the potential for identification
           and evaldation of potential shipwrecks based on the capabilities
           of current technology in relation to the water depth, probable
           thickness and composition of sediments overlying the potential
           shipwreck location, and the preservation potential.
                                 I
                G.   Representative data samples, as appropriate, shall be
           submitted for the following:

                     (1) A representative sample of subbottom profiler data
           for each type of relict landform identified. When more than one
           generation of fluvial channeling is evident, a sample depicting
           each shall be submitted. Each sample must be readable and
           include horizontal and vertical scales. Any interpretive
           highlighting or annotation of the sample data shall be on either
           a separate overlay or a copy of the representative sample data.
           In no instance should original survey data be highlighted. If
           relict channel features are referenced in the text of the
           archaeological report, representative copies of the subbottom
           profiler record of these geologic features shall be included in
           the report.











           E-22
                     (2) A copy of the side-scan sonar data where contacts
           representing unidentified objects are recorded. The copies must
           be readable and shall include the scale. Any highlightIM or
           annotation of the sample data shall be on either a septrate
           overlay or a copy of the representative sample data. In no
           instance should original survey data be highlighted.

                     (3) Magnetometer data as follows:

                          (a) for lease surveys and site specific: surveys,
           a clear copy of three complete lines of magnetometer data. Two
           of these lines shall be representative data samples of primary
           survey lines and the third survey line shall be a cross-tie line.
           The primary survey lines shall be adjacent lines and run in two,
           different cardinal directions (e.g., one survey line heading
           north and the other heading south). Whenever possible these
           survey lines shall include unidentified magnetic anomalies.

                          (b) for pipeline surveys (i.e., lease term or
           right-of-way) that are three miles or longer in length, a clear
           copy of approximately one-quarter (25%) of the magnetometer data
           (analog strip chart) for the center line of the survey. For
           pipeline surveys less than three miles in length, the entire
           center line magnetometer survey shall be submitted. These data
           shall include representative samples of unidentified magnetic
           anomalies (if any) that were recorded on the center line. Sample
           data may be reduced in size for report reproduction. Data
           quality must be sufficient to clearly depict both the 1000-gamma
           and 100-gamma scale traces of the analog strip chart recorder.

               H.   A summary of conclusions and recommendations supported
           by the archaeological resource field survey data and
           archaeological analyses including:

                     (1)  A discu@,sion of known or potential archaeological
           resources;


                     (2)  Recommendations for avoidance or for further
           archaeological investigations; and/or

                     (3)  Recommendation that operations be permitted
           because data recovery negates adverse effects to archaeological
           resources.

               I.   A discussion of the data and results from any
           additional investigations that may be required by the GOMR shall
           be appended to the archaeological resource report.






                                           12










                                                                        E-23
          III. Review of Archaeological Resource Reports

               A.   The GOMR will determine whether a report meets the
          requirements contained in the invocation notification and/or this
          NTL. The review will be conducted by personnel with
          archaeological, geophysical, and other appropriate expertise.
          The GOMR will determine if the survey was performed properly and
          will evaluate the geophysical interpretations and archaeological
          conclusions.

               B.   If the report is not adequate or complete, the GOMR
          will notify the operator or right-of-way holder, in writing, of
          the problems and identify the data or information necessary to
          correct or complete the report.

               C.   Based on the GOMR review of the report findings, the
          GOMR will notify the operator or right-of-way holder, in writing,
          of any mitigating measures or operational restrictions which may
          be required.

               D.   Apreviously submitted archaeological resource report
          may be acceptable for satisfying the archaeological resource
          report requirements under a new lease agreement, particularly if
          the lease falls exclusively within the area of high probability
          for the occurrence of prehistoric archaeological resources.
          Prior to submittal of an Exploration Plan or Development
          Operations Coordination Document, the operator shall submit to
          the Regional Supervisor, Leasing and Environment, a written
          request for review of an archaeological report prepared for an
          expired lease to determine its compliance with current MMS
          requirements. A clean copy of the report to be reviewed shall be
          included with the operator's request.





















                                          13








         E-24                      ENCLOSURE NO. 3

              REQUIREMENTS FOR MITIGATION AND OPERATIONAL RESTRICTIONS

              A.    When an archaeological resource field survey and report
          indicate that a potential archaeological resource may be present
          and lease operations or pipeline right-of-way operations are
          proposed within its immediate area, the GOMR will require the
          operator or right-of-way holder to either:

                    .1.  Locate the operation so as not to adversely affect
          the area of the archaeological resource; or

                    2.   Establish to the satisfaction of the GOMR that an
          archaeological resource does not exist or will not be adversely'
          affected by operations. This shall be done by further
          archaeological investigation, conducted by an archaeologist and a
          geophysicist, using survey equipment and techniques deemed
          necessary by the GOMR. A report on the investigation shall be
          submitted to the GOMR for review.

               B.   If the GOMR determines that an archaeological resource
          is present in the area and may be adversely affected by
          operations, the operator or right-of-way holder will be notified
          immediately. Under these circumstances, the GOMR is required to
          engage in additional consultations in accordance with 36 CFR
          800.4. The operator or right-of-way holder shall take no action
          that may adversely affect the archaeological resource until the
          GOMR has concluded these consultations and has provided the
          operator with instructions on how to protect the resource.

               C.   If the operator or right-of-way holder discovers any
          archaeological resource while conducting operations, a report of
          the discovery shall be immediately made to the GOMR. The
          operator or right-of-way holder shall make every reasonable
          effort to preserve the archaeological resource until the GOMR has
          issued instructions on how to protect it.















                                          14





























                                                                                                                                                                           DA E DUE



















                                                                                                                                               GAYLORD No. 2333                                                  PRINTED IN U S A



















                                                                                                                                                                      3 6668 14106 8173