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


                                                             FY 1992 FINAL PRODUCT Task 51
                                                                     E. Shore Groundwater Ord.














                                    DRAFT GROUNDWATER AMENDMENT



                               Accomack County Comprehensive Plan

                                         September 30, 1993







                                   FOR DISCUSSION PURPOSES ONLY




















                                Technical Assistance Provided by:
                      Accomack-Northampton Planning District Commission
                                            P. 0. Box 417
                                         Accomac, VA 23301









                                    A pubtication of the Virginia Deparom t of Environmentat QuaLity's Coastat
                                    Resources Management Program pursuant to mationat Oceanic and Atmospheric
                                    Administration Award No. 027OZO312-01









          Draft Comprehensive Plan Ground Water Amendment 9/30/93



                                       GROUND WATER



          Introduction
          The availability of water will play an increasingly important role
          in the development of Accomack County.      Accomack County's water
          supply is provided by ground water.       No major streams or other
          surface water supplies exist to supply potable water for human
          needs.    Because ground water is only replenished by rainfall,
          potable drinking water is a renewable but limited resource in
          Accomack County.


          Background
          Ground water is the only source of supply for domestic, industrial,
          and agricultural water use on the Eastern Shore of Virginia.         A
          total population of approximately 45,000 people use this ground
          water. Because of the limited supply of ground water, in 1976 the
          Virginia State Water Control Board designated the Eastern Shore of
          Virginia a "Ground Water Management Area". The Eastern Shore was
          the second area in Virginia to be declared a ground water
          management area. This declaration was based on the findings that:

                -    Ground water level declines have been observed in two
                     sections of Accomack County;

                -    Interference between wells has been observed in the same
                     two sections of Accomack County;

                -    Some evidence of localized ground water contamination has
                     been observed in the water table aquifer of Accomack
                     County but not in the confined aquifers;

                -    Even though the ground water supplies in Accomack County
                     are not overdrawn and are not expected to be in the near
                     future, it should be recognized that they may overdraw
                     in some areas in the future if water withdrawals are not
                     distributed throughout the region.     Further, saltwater
                     intrusion has not been observed to date but may occur in
                     the future if heavy ground water withdrawals are
                     concentrated in any one area.

          At the request of Accomack and Northampton Counties, in 1990 the
          Accomack-Northampton Planning District Commission commissioned the
          development of a Ground Water Management and Supply Protection Plan
          to provide a comprehensive and practical series of options,
          alternatives and specific actions to promote compatibility between
          the Eastern Shore's water resources and the counties' land use
          plans.





                   -Z.)
                   r,-
                 Z









           Draft Comprehensive Plan Ground Water Amendment 9/30/93

           The bi-county Eastern Shore of Virginia Ground Water Study
           Committee was formed to oversee the development of the Ground Water
           Plan.   The Committee consists of two members from each County's
           Board of Supervisors, one citizen appointed by each Board of
           Supervisors, the County Administrator from each county, and the
           Executive Director of the Accomack-Northampton Planning District
           Commission. On May 5, 1992 the Committee adopted the Ground Water
           Supply Protection and Management Plan for the Eastern Shore of
           Virginia. The plan includes a detailed analysis of Eastern Shore
           ground water resources and issues, and makes recommendations for
           the protection and management of the ground water.


           Eastern Shore of Virginia Ground Water Syste
           The aquifers on the Eastern Shore are strongly influenced by
           geology, rainfall, and ground water use. There are basically two
           components to the Eastern Shore ground water system, the upper
           Columbia aquifer, and the lower Yorktown-Eastover aquifer.

           Columbia Aquifer. The upper Columbia aquifer is unconfined, and is
           roughly 80 to 100 feet thick. This aquifer is used primarily for
           private on-site domestic wells, and agricultural irrigation.
           Approximately 2 million gallons per day are withdrawn from the
           Columbia aquifer by private on-site wells for domestic use. Some
           portion of the 8.7 million gallons per day withdrawn for irrigation
           comes from the Columbia aquifer.

           Yorktown-Ea stover Aquifer.     The Yorktown-Ea stover Aquifer is a
           confined aquifer system consisting of coarse shelly sand found in
           three layers that are separated by clay confining units.           This
           aquifer can range in depth from 80 to 800 below the land surface,
           though most wells are pumping form layers between 150 and 300 feet
           deep.

           Industrial withdrawals and public water supply wells are
           exclusively screened in the Yorktown-Ea stover aquifer, while wells
           used for agriculture and private household use are withdrawn from
           the upper aquifer.     Currently 4.5 million gallons per day are
           withdrawn from the Yorktown-Eastover aquifer for industrial use and
           public water supply.

           Ground Water Recharge. Annual precipitation of 42 inches per year
           provides the recharge to the Eastern Shore aquifers. Approximately
           12-24 inches per year of precipitation recharges the Columbia
           aquifer on the Eastern Shore of Virginia. At an average recharge
           rate of 17 inches per year, approximately 324 million gallons per
           day recharge the Columbia aquifer. Most of this water flows from
           the middle of the peninsula and discharges to the Chesapeake Bay
           and the Atlantic Ocean, providing an important source of fresh
           water for our tidal creeks and bays.

                                             2









          Draft Comprehensive Plan Ground Water Amendment 9/30/93

          The clay confining layers that separate the Columbia aquifer from
          the Yorktown -Ea stover serve to protect the aquifer from many of the
          water quality threats. But the clay confining units also act to
          impede the amount and rate of recharge to the aquifer.         Only a
          small percentage of the precipitation that recharges the Columbia
          aquifer contributes to the recharge of the deeper confined aquifer.
          It is estimated that only 1.2 inches of precipitation recharge the
          Yorktown-Eastover aquifer annually.

          Based upon the ground water modelling studies conducted,
          approximately 11 million gallons per day is recharged to the
          Yorktown-Eastover aquifer. However, it should be noted that this
          recharge value is based on average conditions across the entire
          Eastern Shore. Depending upon specific site conditions recharge to
          the Yorktown-Eastover aquifer may vary by a factor of two.

          Ground Water Ouality.     Water quality in the Columbia aquifer is
          threatened by the many land uses that discharge, leach or dispose
          of contaminants to the ground water.        Nitrate-nitrogen is the
          primary contaminant of concern to the Columbia aquifer. Sources of
          nitrate    nitrogen   include:       septic   systems;    agricultural
          fertilizers; manure storage and animal disposal; septage lagoons;
          and landfills.    In addition, pesticides and underground storage
          tanks are also threats.

          The average nitrogen concentration in the ground water was
          calculated to be 2.0 milligrams per liter. The national drinking
          water standard for nitrogen is 10 milligrams per liter. On average
          the shallow ground quality is considered very good, however those
          areas located down slope from major nitrogen users or disposers may
          experience much higher nitrogen concentration.


          Ground Water Issues and Concerns
          Local planning and elected officials on the Eastern Shore have been
          concerned for a number of years about the quality and availability
          of ground water.      The Virginia State Water Control Board has
          conducted several studies and has developed a network of ground
          water monitoring wells on the Eastern Shore to document problems.
          In addition, through cooperative studies, the U.S. Geological
          Survey has developed reports and modelled the hydrogeology. The
          results of these investigations all agree that the major ground
          water issues are:

                - Development Impacts, Septic Systems, Underground Tanks
                - Industrial and Public Water Supply Wells
                - Well Interference, Salt Water Intrusion
                - Agriculture, Water Quality and Quantity
                - Animal Wastes
                - Adequate Water Supply for Future Demands

                                             3










                                     Figure 2-5 Generalized EastfWest Cross Section





                                GENERALIZED EAST / WEST CROSS-SECTION
                               OF GROUND WATER FLOW ON THE EASTERN
                                             SHORE OF VIRGINIA






                            WEST                 lCentral Plateau                 EAST
                          Chesapeake            PRECIPITATION                     Atlantic
                             Bay                                                  Ocean


                                                                    Water Table
                                                                           Piezometric Level


                                                             . ..............


                                                                  ........... ......
                                                      ....... ......       ........
                                                . . . . . ............. . ....... . . . . ... ....
                                                     ...... ......  ...............
                                                                                  J:
                                                                 . . . ... .......




                                           ........ ...............
                                               . .. .... ..      ...
                                                                 . ..... .... . .....

                                                               v. ........
                                                ......... . ....
                                            ........ . . .. ...... .. . ... .

                                                         . .................





                                                                  .............


                                                         ...........  ......
                                                               .. .... ......


                                Saft                                           Saft
                               Gr
                                 ound                                          roun
                                                                              Water
                                 ater R
                                        f
                                        F
                              TIT**



                           Lj Fresh Water Aquifer
                           E]   Fresh Water Aquitard







                       Ground Water Supply Protection and Maragement Plan for the Eastern Shore of Virginia

                                                       4









          Draft Comprehensive Plan Ground Water Amendment 9/30/93

          Each of these activities/concerns have an impact on water use and
          quality for either the upper aquifer, the lower aquifer or both.
          The Ground Water Supply Protection and Management Plan For the
          Eastern Shore of Virginia provides a review of each of these
          threats.



          Adequate Water SupplV for Future Demands

          Although it is estimated that there is only 11 million gallons per
          day available from the Yorktown-Eastover aquifer, current permits
          issued by the Virginia State Water Control Board would allow
          withdrawals of up 15.6 million gallon per day from this aquifer.
          If this were to occur, problems of well interferences and salt
          water intrusion, already observed near the largest industrial water
          users, will be greatly enhanced.


          Recommendations
          Based upon the analyses conducted and the review of existing
          information, the study proposes the following actions:


          Recommendations for Water Ouality Protection:

                -    Pursue water conservation measures with major industrial
                     users.


                -    Create an overlay protection zoning district to protect
                     the spine recharge area to the Yorktown-Eastover aquifer;

                -    Restrict the siting of new mass drainfields in the spine
                     recharge area;

                -    Review and revise county zoning and subdivision
                     regulations; - Require the registration of currently
                     unregulated underground storage tanks;

                -    Incorporate ground water protection requirements into
                     site plan review;

                -    Develop a private well ordinance to control the siting
                     and construction of new wells;

                -    Support the implementation of agricultural nutrient
                     management plans;

                -    Implement the provisions of the Chesapeake Bay Program.



                                            5









                        FIGURE 2-6.
                        Conceptual Hydrogeologic Model of Non-Pumping Ground Water Conditions.
                        on the Eastern Shore of Virginia



                      Chesapeake            Columbia                            Confining                                   Upper Yorktown -Eastover                            Upper Yo rktown- Eastover                  Atlantic
                      Bay                   Aquifer                             Unit                                         Aquifer                                            Confining Unit                              Ocean






                                                                                                                                                                                                                T @@i
                                                                    . . . . . . . . . . . . .


                         salt                                                                                                                                                                                              salt
                        W a ter.,:
                                                                                                                                                                                                                          Water


                                                                                                                                        . . . . . . . . . . . . . . . .

                                                                                                                 @4 . ........ .. ..


                                                                                                                                                           ..........
                                                                                                                                                                        ..... ... ........
                                                                                                                  . . . ..... .
                                                                                                                              .......        ..
                                                                                                                                                                                           ....... ...
                                                                                                                                    ............




                                                                                                                                                           ...........................




                                                      Middle Yorktown-Eastover                                  Middle Yorktown-Eastover                               Lower Yorktown -Eas tove r
                                                      Aquifer                                                   Confining Unit                                         Aquifer
                                     F-1 Recharge Pathway Flow to Columbia Aquifer
                                     El       Recharge Pathway Flow to Upper York town-Eastover Aquifer
                                                                                                                                    I.-















                                              Recharge Pathway Flow to Middle York town-Ea stover Aquifer
                                              Recharge Pathway Flow to Lower Yorktown-Eastover Aquifer

                                                                                                                     6















                                                                                             ATLANTIC              OCEAN


                                            WPA-A
                                                                            WPA-B                WPA-C
                                                                                                                                                 WPA-D                        WPA-E

                                                                                                                                                                       6-1;










                                                                                                                                         J,










                                                                                                                                   8 4y
                                                                                                            c   -S4qcPv

                          WELLHEAD PROTECTION AREA
                          (maximum permitted pumping rates)

                          WELLHEAD PROTECTION AREA
                          (existing pumping rates)


                          SPINE RECHARGE AREA
              ...... ......





                   li@                  22.000 33.000









          Draft Comprehensive Plan Ground Water Amendment 9/30/93

          Recommendations for Water Ouantity Management
               -     Revise State Ground Water Act and Regulations to allow
                     for re-evaluation of existing permits; ,

               -     Develop an Eastern Shore Water Management District to
                     manage water withdrawals;

               -     Control the siting and development of new water supply
                     wells to prevent well interference and reduce the threat
                     of salt water intrusion;

               -     Continue the Accurate reporting of agricultural water
                     withdrawals, by well location and depth.

               -     Continue the consideration of mandatory permitting of
                     agricultural withdrawals after review of reporting data.

               -     Protect open space and undeveloped land in the spine
                     recharge area.


          General Recommendations

                     Implement a land use/water quality data base;

                     Develop a public education program on ground water.


          Continued Research and Investigation

               -     Investigate the nature of recharge to the Yorktown-
                     Eastover aquifer;

               -     Research dilute salt water issues;

               -     Conduct additional hydrogeologic studies to better define
                     the geology;

               -     Evaluate pesticide use on the Eastern Shore;

               -     Revise the nitrogen Tnodel used in the study over time.


          Goals and  Objectives for Ground Water Protection
          The Eastern Shore of Virginia is situated over a very valuable
          ground water resource that is the sole source of water supply to
          the inhabitants and is also necessary for both industrial and
          agricultural use.   Protection of the water quality and quantity
          requires the development of goals and objectives designed to
          maintain water quality, prevent over use of the aquifer, and

                                           8









           Draft Comprehensive Plan Ground Water Amendment 9/30/93

           provide for the future needs to accommodate growth on the Eastern
           Shore.


           Goals and Obiectives for Ground Water Ouality Protection

           Goal:           Achieve industrial water conservation.

           objective:      Work with local industry to develop industrial
                           water conservation programs.


           Goal:           Protect the spine recharge area to the Yorktown-
                           Eastover aquifer.

           objective:      Restrict the siting of new mass drainfields,
                           septage lagoons, and landfills, and protect open
                           space in the spine recharge area.


           Goal:           Protect groundwater from development impacts such
                           as overly dense development, failed septic systems,
                           and leaking underground storage tanks.

           objective:      Revise county zoning and subdivision regulations to
                           include development standards and site plan review
                           which provide for proper land development and
                           proper siting and construction of septic systems,
                           private wells, and underground storage tanks.


           Goal:           Minimize ground water impacts from agricultural
                           activities.

           objective:      Provide assistance in developing agricultural
                           nutrient management plans and implement the
                           provisions of the Chesapeake Bay Preservation Act.
           Goals:          Educate the public about proper ground water use
                           and education.

           objective:      Develop a public education program on ground water.


           Goals and Objectives for Ground Water Ouantity Management

           Goal:           Re-evaluate existing ground water permits.

           objective:      Revise State Ground Water Act and Regulations to
                           allow for re-evaluation of existing permits.



                                             9









           Draft Comprehensive Plan Ground Water Amendment 9/30/93

           Goal:           Control the siting and development of new water
                           supply wells to prevent well interference and
                           reduce the threat of salt water intrusion by
                           managing Eastern Shore ground water withdrawals.

           objective:      Develop an Eastern Shore Water Management District
                           to manage water withdrawals.

           Goal:           Accurately document agricultural ground water
                           withdrawals.

           objective:      Continue the accurate reporting of agricultural
                           water withdrawals, by well location and depth.

           Goal:           Accurately document and record ground water
                           quantity and quality.

           Objective:      Implement a land use/water quality data base;


           Goal:           Improve knowledge of Eastern Shore ground water
                           system.

           Objective:      Investigate the nature of recharge to the Yorktown-
                           Eastover aquifer, research dilute salt water
                           issues, conduct additional hydogeologic studies to
                           better define the geology, evaluate pesticide use
                           on the Eastern Shore, revise the nitrogen model
                           used in the study over time.


           Actions for Ground Water Protection and Management
           Protection of the water quality and quantity will require the
           implementation of many actions designed to maintain water quality,
           prevent over use of the aquifer, and provide for the future needs
           to accommodate growth on the Eastern Shore.


           Actions for Ground Water Ouality Protection

           Action:   Develop an industrial water conservation program.


           Action:   Develop regulations to restrict the siting of new mass
                     drainfields, septage lagoons, and landfills, and to
                     protect open space in the spine recharge area.


           Action:   Revise county zoning and subdivision regulations to
                     include development standards and site plan review which

                                             10









          Draft Comprehensive Plan Ground Water Amendment 9/30/93

                     provide for proper land development and proper siting and
                     construction of septic systems, private wells, and
                     underground storage tanks.


          Action:    Provide assistance in developing agricultural nutrient
                     management plans and implement the provisions of the
                     Chesapeake Bay Preservation Act.

          Action:    Develop a public education program on ground water.


          Actions for Ground Water Ouantity Management

          Action:    Participate in re-evaluation of existing ground water
                     withdrawal permits.

          Action:    Develop an Eastern Shore Water Management District to
                     manage water withdrawals and control the siting and
                     development of new water supply wells to prevent well
                     interference and reduce the threat of salt water
                     intrusion by managing Eastern Shore ground water
                     withdrawals.

          Action:    Document the accurate reporting of agricultural water
                     withdrawals, by well location and depth.

          Action:    Develop a land use/water quality data base by accurately
                     documenting and recording ground water quantity and
                     quality.

          Action:    Investigate the nature of recharge to the Yorktown-
                     Eastover aquifer, research dilute salt water issues,
                     conduct additional hydogeologic studies to better define
                     the geology, evaluate pesticide use on the Eastern Shore,
                     revise the nitrogen model used in the study over time.







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