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Coa."stal Zone )07,57 informationI Center VOLUME 5 Water Supply 41 rAL 7PINE MEN ;@o , 4F_ - Ogg 777, Ache MN%A% Mira% ms n FMIW CMDfnow U..S DEPARTMENT OF COMMERCE NOAA COASTAL SERVICES CENTER 2234 SOUTH HOBSON AVENUE CHARLESTON, SC 29405-2413 )07,37 COUTAL ZONE IWORMATION CENTER PREFACE AUG 2 9 1977 The Corps of Engineers' comprehensive study of Chesapeake Bay is being accomplished in three distinct developmental stages or phases. Each of these phases is responsive to one of the following stated objectives of the study program. 1. To assess the existing physical, chemical, biological, economic and environmental conditions of Chesapeake Bay and its related land resources. 2. To project the future water resources needs of Chesapeake Bay to the year 2020. 3. To formulate and recommend solutions to priority problems using the Chesapeake Bay Hydraulic Model. In response to the first objective of the study, the initial or inventory phase of the program was completed in 1973 and the findings were published in a document titled Chesapeake Bay Existing Conditions Report. Included in this seven-volume report is a description of the existing physical, economic, social, biological and environmental conditions of Chesapeake Bay. This was the first published report that presented a comprehensive survey of the entire Bay Region and treated the Chesapeake Bay as a single entity. Most importantly, the report contains the historical records and basic data required to project the future demands on the Bay and to assess the ability of the resource to meet those demands. In response to the second objective of the study, the findings of the second or future projections phase of the program are provided in this the Chesapeake Bay Future Conditions Report. The primary focus of this report is the projection of water resources needs to the year 2020 and the identification of the problems and conflicts which would result from the unrestrained growth and use of the Bay's resources. This report, therefore, provides the basic information necessary to proceed into the next or plan formulation phase of the program. It should be emphasized that, by design, this report addresses only the water resources related needs and problems. No attempt has been made to identify or analyze solutions to specific problems. Solutions to priority problems will be evaluated in the third phase of the program and the findings will be published in subsequent reports. _3 A lx@ The Chesapeake Bay Future Conditions Report consists of a summary document and 16 supporting appendices. Appendices I and 2 are general background d6cuments containing information describing the history and conduct of the study and the manner in which the study was coordinated with the various Federal and State agencies, scientific institutions and the public. Appendices 3 through 15 each contain information on specific water and related land resource uses to include an inventory of the present status ft*SNWL7 Of C8C Libra2:y and expected future needs and problems. Appendix 16 focuses on the formulation of the initial testing program for the Chesapeake Bay Hydraulic Model. Included in this appendix is a description of the hydraulic model, a list of problems considered for inclusion in the initial testing program and a detailed description of the selected first year model studies program. The published volumes of the Chesapeake Bay Future Conditions Report include: Volume Number Appendix Number and Title I Summary Report 2 1 - Study Organization, Coordination and History 2 - Public Participation and Information 3 3 - Economic and Social Profile 4 4 - Water-Related Land Resources 5 5 - Municipal and Industrial Water Supply 6 - Agricultural Water Supply 6 7 - Water Quality 7 8 - Recreation 8 9 - Navigation 10 - Flood Control I I - Shoreline Erosion 9 12 - Fish and Wildlife 10 13 - Power 14 - Noxious Weeds IS - Biota 12 16 - Hydraulic Model Testing 41 CORSTAL ZONE MFORNATION, CENTER CHESAPEAKE BAY FUTURE CONDITIONS REPORT APPENDIX 5 MUNICIPAL AND INDUSTRIAL WATER SUPPLY TABLE OF CONTENTS Chapter Page- I THE STUDY AND THE REPORT I Authority 2 Purpose 3 Scope 4 Supporting Studies 4 Study Participation and Coordination 6 11 WATER SUPPLY IN THE CHESAPEAKE BAY AREA 7 Description of the Region 7 Resources 9 History I I Existing Public Water Supply 12 Present Water Use 13 Existing Problems and Conflicts 18 Management Responsibilities 21 Existing -Industrial Water Supply 23 Present Industrial Use 25 Existing Problems and Conflicts 31 Management Responsibility 32 Summary 32 FUTURE WATER SUPPLY NEEDS 35 Municipal Water Supply Demands 36 Assumptions 37 Methodology 38 Projected Municipal Demands 42 Industrial Water Supply Demands 42 Discussion 47 Assumptions 51 Methodology, 52 Projected Industrial Demands 55 Available Water Supplies 55 Hydrologic Considerations 55 Assumptions and Criteria 65 Methodology and Results 65 Appendix -5 iii TABLE OF CONTENTS (cont'd) Chapter Page III Future Needs and Problem Areas 75 (cont'd) Subregion 1 78 Subregion 2 81 Subregion 3 81 Subregion 4 84 Subregion 5 86 Subregion 6 90 Subregion 7 90 Subregion 8 92 Subregion 9 94 Subregion 10 96 Subregion 11 98 Subregion 12 100 IV SENSITIVITY ANALYSIS 103 Impact of Population Changes on Municipal Water Demands 103 Impact of Water Reuse on Industrial Demands 106 Assumptions and Methodology 108 Results 108 V MEANS TO SATISFY THE NEEDS 117 Developmental Measures 117 Surface Supplies 118 Groundwater 122 Desalting as an Alternative Source 127 Institutional Measures 129 VI REQUIRED FUTURE STUDIES 131 FOOTNOTES 133 BIBLIOGRAPHY 137 GLOSSARY 139 ATTACHMENTS Or PLATES Appendix iv LIST OF TABLES Number Title Page 5-1 Municipal Water Use, 1970 14 5-2 Service Population: Small Water Systems, By County, 1970 19 5-3 Industrial Water Use in the Chesapeake Bay Area, 1970 26 5-4 Water Use in Manufacturing, By Sector, Chesapeake Bay Area 27 5-5 Industrial Water Withdrawals, By Source, Chesapeake Bay Area 29 5-6 Water Use in Manufacturing, National Comparison, By Use 30 5-7 Projected Municipal and Industrial Demands 43 5-8 Projected Water Use By Small Systems, Chesapeake Bay Area, 1970-2020 46 5-9 Water Use in Manufacturing, By Sector, Chesapeake Bay Area, Projection Set 3 56 5-10 Projected Water Use in Manufacturing, Projection Set 3 58 5-11 Municipal Source and System Capacities 67 5-12 Subregional Freshwater Availability 76 5-13 Peaking Factors for Municipal Demands 77 5-14 Future Municipal Source and System Deficits, Subregion 1 79 5-15 Aggregated Demands Versus Freshwater Resource, Subregion 1 81 5-16 Future Municipal Source and System Deficits, Subregion 2 82 5-17 Aggregated Demands Versus Freshwater Resource, Subregion 2 84 5-18 Aggregated Demands Versus Freshwater Resource, Subregion 3 84 5-19 Future Municipal Source and System Deficits, Subregion 4 85 Appendix 5 V LIST OF TABLES (cont'd Number Title Page 5-20 Aggregated Demands Versus Freshwater Resource, Subregion 4 86 5-21 Future Municipal Source and System Deficits, Subregion 5 87 5-22 Aggregated Demands Versus Freshwater Resource, I Subregion 5 88 5-23 Future Municipal Source and System Deficits, Subregion 6 89 5-24 Aggregated Demands Versus Freshwater Resource, Subregion 6 90 5-25 Future Municipal Source and System Deficits, Subregion 7 91 5-26 Aggregated Demands Versus Freshwater Resource, Subregion 7 92 5-27 Future Municipal Source and System Deficits, Subregion 8 93 5-28 Aggregated Demands Versus Freshwater Resource, Subregion 8 94 5-29 Future Municipal Source and System Deficits, Subregion 9 95 5-30 Aggregated Demands Versus Freshwater Resource, Subregion 9 96 5-31 Future Municipal Source and System Deficits, Subregion 10 97 5-32 Aggregated Demands Versus Freshwater Resource, Subregion 10 98 5-33 Future Municipal Source and System Deficits, Subregion 11 99 5-34 Aggregated Demands Versus Freshwater Resource, Subregion I 1 100 5-35 Future Municipal Source and System Deficits, Subregion 12 101 Appendix -5 vi LIST OF TABLES (cont'd) Number Title Page 5-36 Aggregated Demands Versus Freshwater Resource, Subregion 12 102 5-37 A Comparison of OBERS Series C and Series E Projections 105 5-38 Water Use in Major Systems Under Series E Population Projections 107 5-39 Water Use in Manufacturing with Various Assumptions on Future Technology 109 5-40 Water Intakes in Manufacturing with Varying Technology, By Subregion ill 5-41 Water Use in Manufacturing with Advanced Technology, By Sector, Chesapeake Bay Area 113 5-42 Probability of Low-Flow Occurrence 122 5-43 Representative Groundwater Retrieval Costs, 1970 126 LIST OF FIGURES Number Title Page 5-1 Subregional Breakdown of the Chesapeake Bay Study Area 5 5-2 The Chesapeake Bay Region 8 5-3 Annual Average Freshwater Use By Type, 1970 33 5-4 Non-Industrial Per Capita Use Rate Versus Income, 1970 39 5-5 Rate of Growth in Per Capita Use Rate 40 5-6 Industrial Water Use Technology, Projection Sets I and 2 49 5-7 Trends in Industrial Water Use Technology, Projection Sets 1, 2, and 3 50 5-8 Industrial Water Use with Various Levels of Technological Advance 110 Appendix 5 vii LIST OF FIGURES (cont'd) Number Title Page 5-9 Capacity-Area Curves, Triadelphia Reservoir, Maryland 120 5-10 Storage to Effect a Given Increase in Dependable Flow (Potomac River Basin) 121 5-11 Relationship Between Ground and Surface Waters 123 5-12 Effect of Price on Domestic Water Use 130 LIST OF ATTACHMENTS Number Title Page 5-A Projected Non-Industrial Water Demands, Chesapeake Bay Area, 1980-2020 A- I 5-B Surface Water Flows B-1 5-C Developable Groundwater Resource C_ I 5-D Existing Storage Facilities D-1 5-E Significant Institutional Water Users, By. Subregion E- I 5-F Agricultural Water Use Summary F- I 5@G Comparison of Recent Population Data G-1 LIST OF PLATES Number Title 5-1 Water Supply Subregion 1, 2 (Northern Portion) 5-2 Water Supply Subregion 5 5-3 Water Supply Subregion 2 (Southern Portion), 4 6, 7, and 9 (Northern Portion) 5-4 Water Supply Subregion 3, 8, 9 (Southern Portion), 10, 11, and 12 Appendix 5 viii CHAPTER I THE STUDY AND THE REPORT The Chesapeake Bay Study evolved through the need for a complete and comprehensive investigation of the use and control of the water resources of the Bay Area. Chesapeake Bay is a vast natural resource. Along with its tributaries, the Bay provides a natural transportation network on which the economic development of the Region has been based, a wide variety of water- oriented recreational opportunities, a home for numerous fish and wildlife, a source of water supply for both municipalities and industries, and the site for final disposal of our waste products. All of the natural resources provided by the Bay interact with each other, in conjunction with the activities of man, to form a complex but interrelated system. Unfortunately, problems often arise when man's intended use of one resource conflicts with either the natural environment or man's use of another resource. It was towards a plan for the most efficient use of the Bay's natural resources that the Chesapeake Bay Study was conceived. In the first phase of the Study, the existing physical, biological, economic, social, and environmental conditions and problem areas were identified and presented in the Existing Conditions Report. The Future Conditions Report, of which this appendix is a part, presents the findings of the second or projections phase of the Study. Included as part of the second phase are the projections of future water resource needs and problem areas, identification of general means that might best be used to satisfy those needs, and recommendations for future studies and hydraulic model testing. The results of this phase of the Study and this report constitute the next step toward the goal of developing a comprehensive water resource management program for Chesapeake Bay. The tributaries that flow into the Bay serve as sources of municipal and industrial water supply as do the vast ground water resources that underlie the Bay Region. The demands on both the surface and ground water resources have increased substantially in the past two decades and are expected to increase even more over the next 50 years. As these demands on the Bay's sources of freshwater increase, conflicts will arise between those activities or -101 resources that require freshwater. The subject of this volume is municipal and industrial water supply, and as 40; such, will focus on the existing and future demands for freshwater in the Bay Region. In addition to identif@ying the future water supply demands, this volume also provides an assessment of both available freshwater supplies and potential deficits. Also included is a discussion of the measures that can be Appendix 5 used to either meet or control future water supply demands. Those studies required to develop comprehensive water supply plans for the Chesapeake Bay Region are also identified. AUTHORITY The authority for the Chesapeake Bay Study and the construction of the 4 hydraulic model is contained in Section 312 of the River and Harbor Act of 1�65, adopted 27 October 1965, which reads as follows: (a) The Secretary of the Army, acting through the Chief of Engineers, is authorized and directed to make a complete investigation and study of water utilization and control of the Chesapeake Bay Basin, including the waters of the Baltimore Harbor and including, but not limited to, the following: navigation, fisheries, flood control, control of noxious weeds, water pollution, water quality control, beach erosion, and recreation. In order to carry out the purposes of this section, the Secretary, acting through the Chief of Engineers, shall construct, operate, and maintain in the State of Maryland a hydraulic model of the Chesapeake Bay Basin and associated technical center. Such model and center may be utilized, subject to such terms and conditions as the Secretary deems necessary, by any department, agency, or instrumentality of the Federal Government or of the States of Maryland, .Virginia, and Pennsylvania, in connection with any research, investigation, or study being carried on by them of any aspects of the Chesapeake Bay Basin. The study authorized by this section shall be given priority. (b) There is authorized to be appropriated not to exceed $6,000,000 to carry out this section. An additional appropriation for the study was provided in Section 3 of the River Basin Monetary Authorization act of 1970, adopted 19 June 1970, which reads as follows: In addition to the previous authorization, the completion of the Chesapeake Bay Basin Comprehensive Study, Maryland, Virginia, and Pennsylvania, authorized by the River and Harbor Act of 1965 is hereby 0- authorized at an estimated cost of $9,000,000. As a result of Tropical Storm Agnes, which caused extensive damage in Chesapeake Bay, Public Law 92-607, the Supplemental Appropriation Act of 0 1973, signed by the President on 31 December A72, included $275,000 for additional studies of the impact of the storm on Chesapeake Bay. Appendix 5 2 PURPOSE Historically, measures taken to utilize and control the water and land resources of the Chesapeake Bay Basin have generally been oriented toward solving individual problems. The Chesapeake Bay Study provides a comprehensive study of the entire Bay Area in order that the most beneficial use be made of the water-related resources. The major objectives of the Study are to: a. Assess the existing physical, chemical, biological, economic, and environmental conditions of Chesapeake Bay and its water resources. b. Project the future water resources needs of Chesapeake Bay to the year 2020. c. Formulate and recommend solutions to priority problems using the Chesapeake Bay Hydraulic Model. The Chesapeake Bay Existing Conditions Report, published in 1973, met the first objective of the Study by presenting a detailed inventory of the Chesapeake Bay and its water resources. Divided into a summary and four appendixes, the report presented an overview of the Bay Area and the economy; a survey of the Bay's land resources and its use; and a description of the Bay's life forms and hydrodynamics. The purpose of the Future Conditions Report is to provide a format for presenting the findings of the Chesapeake Bay Study. Satisfying the second objective of the Study, the report describes the present use of the resource, presents the demands to be placed on the resource to the year 2020, assesses the ability of the resources to meet future demands, and identifies additional studies required to develop a management plan for Chesapeake Bay. This particular appendix was developed as the water supply link in the assessment of the future conditions of the Bay. The findings in this volume, as regards the future needs for water, will provide a basis for comparison with other resource categories. Since it is understood that future growth in water supply demand will vary according to many local conditions, the results presented here are not intended as detailed assessments of the future water needs for the individual water systems. Rather, the demands are intended more as a guide for region-wide resource analysis and problem identification. In the sense that future uses and consumptive losses of water may cause A, conflicts with other resource categories and uses, the information presented here will also serve to identify these present or emerging conflicts. Appendix 5 3 SCOPE The scope of the Chesapeake Bay Study and the Future Conditions Report includes the fields of engineering and the social, physical, and biological sciences. The Study is being coordinated with all Federal, State, and local agencies having an interest in Chesapeake Bay. Each resource category or problem area has been treated on an individual basis with demands and potential problem areas projected to the year 2020. The results of the studies conducted for each resource category are presented in a separate appendix to the Future Conditions Report. All conclusions are based on historical information supplied by the preparing agencies having expertise in that field. In addition, the basic assumptions and methodologies are quantified for accuracy in the sensitivity section. Only general means to satisfy the projected resource needs are presented, as specific recommendations are beyond the scope of this report. The geographical area considered in the overall study encompasses those counties or Standard Metropolitan Statistical Areas (SMSA) which adjoin or have a major influence on the Estuary. For purposes of projecting the future demands on the resources of the Bay, economic and demographic projections were made for all subregions and SMSA's within the Study Area. Regarding water supply, the Study Area was divided into 12 subregions as shown on Figure 5-1. The subregions coincide exactly with the standard SMSA and county grouping designations, except Subregions 2 and 4. Subregion 4 is defined for the purpose of this report as Sussex County, Delaware. Subregion 2 is the "non-SMSA," Maryland, portion of the Baltimore Economic Area, expanded to include Cecil County, Maryland. Detailed maps of each of the subregions considered in this appendix are presented as Plates 5-1 through 5-4 at the back of this report. SUPPORTING STUDIES This appendix was prepared and coordinated by the Baltimore District, Corps of Engineers; however, much of the information included in this report was derived from other sources. Population projections were prepared for each county in the Bay Area, and each city of over 2,500 persons, by the Bureau of Economic Analysis, U.S. Department of Commerce. Projections of industrial water supply were prepared specifically for the Chesapeake Bay Study by the Bureau of Domestic Commerce of the U.S. Department of Commerce. In addition, all agricultural demands, including rural domestic, livestock and poultry, and irrigation uses, were projected for this Study by the Economic Research Service, U.S. Department of Agriculture. The Economic Research Service work is presented in its entirety in Appendix 6 - Agricultural Water Supply. The initial data base and resource inventory for all resource categories in the Chesapeake Bay Study, including water supply, were presented in the Aq.nendix 5 4 z 'T, iA i 14ARRISOU Rd SaIem Cecil Harford Carroll New re Bal Castle im E!1 !A L IMORE 41 Howard Ken k-@, n n, ee r 'A r F e DOVER Montgome unde Loudoun A NA L10 Kent Arl Cato @NASHI TO D. line Ta I Fauquier Fairfax falls Ch rch Fairfax rince NP 11C George Prince C Sussex a m exanad Vert Charles DEL Dorchester Culpeper Stafford St- M D Wicomico Marys -IN W ter e Spotsylva ame V orces rse Fr ricks es - mor land Carolihe Ric Nor 1X& m- um erl Essex Lan- Ing Accoma Hanover King 7" caster . . .. ... .0'--N 'lliam ueen 7"@ -"Y" Henrico A New 'TV Kent HHUM D louces- -V orth ter amP, d Chesterliel ritv o Cit to Hopewell 9 Prince bulonia Georg Heights ry Sur etersbutg inwiddie sle of Wi fit IV I r 0o of s- mouth South- ampton Suffolk he k FIGURE 5-1 Subregional Breakdown of the Chesapeake Bay Study Area Appendix 5 5 Chesapeake Bay Existing Conditions Report. Other studies that provided input to this appendix include the Northeastern United States Water Supply Report, and the North Atlantic Regional Water Resources Study prepared by the North Atlantic Division, Corps of Engineers. Numerous water supply studies prepared by local planning agencies were also very helpful in the preparation of this appendix. All sources of data used in this appendix are referenced in the bibliography. STUDY PARTICIPATION AND COORDINATION Due to the wide scope, large geographical area, and many resources covered by the Chesapeake Bay Study, data input was required from many sources. Various Federal, State, and local agencies throughout the Bay Region have customarily developed expertise in certain areas of water resource development. Although overall coordination of the Study effort was provided by the Corps of Engineers, input from these various sources was required in order to obtain the best Study coordination and problem identification. Therefore, an Advisory Group and a Steering Committee were established. Five Task Groups were also formed to guide preparation of reports on related resource categories. They are: I . Economic Projection Task Group 2. Water Quality and Supply, Waste Treatment, Noxious Weeds Task Group 3. Flood Control, Navigation, Erosion, Fisheries Task Group 4. Recreation Task Group 5. Fish and Wildlife Coordination Group Detailed information on the composition of each Task Group as well as the, members of the Advisory Group is presented in the Chesapeake Bay Plan of Study and in Appendix 1, "Study Organization, Coordination, and History." This appendix was prepared by the Baltimore District, Corps of Engineers, under the guidance of the Water Quality and Supply, Waste Treatment, and Noxious 'Weeds Task Group. The Group is chaired by the Environmental Protection Agency and members include the U.S. Departments of Agriculture, Commerce, Interior, Navy, and Transportation; the Federal Power Commission; the Energy Research and Development Administration; the Corps of Engineers; the Susquehanna River Basin Commission; and representatives of the States of Maryland and Delaware, th e Commonwealths of Pennsylvania and Virginia, and the District of Columbia. APDendix 5 6 CHAPTER 11 WATER SUPPLY IN THE CHESAPEAKE BAY AREA Man uses water to meet a wide variety of needs including domestic (drinking, food preparation, waste transport and fire fighting); agricultural (irrigation and livestock watering) and industrial (processing and cooling) purposes. This appendix focuses on municipal and industrial water needs while agricultural and cooling water needs for power generation are addressed in Appendices 6 and 13, respectively. This chapter includes a summary description of the Bay Region and its resources, an inventory of present municipal and industrial water use and problems, and a description of the water supply management entities within the Region. DESCRIPTION OF THE REGION The Chesapeake Bay and the tidal portions of its tributaries combine to form one of the largest estuaries in the United States. The drainage area of the Bay's tributaries totals 64,000 square miles and includes portions of the states of Maryland, West Virginia, Delaware, New York, and the Commonwealths of Virginia and Pennsylvania, and all of the District of Columbia. Many of the more than 150 rivers and creeks which flow to the Bay provide supplies of water needed for municipal, industrial and agricultural purposes. Through these streams, an average of 45,000 million gallons per day of freshwater enter the Bay. The Susquehanna River alone provides approximately 50 percent of the total. Other major rivers in the Bay system include the Potomac, James, York, and Rappahannock, which together provide an additional 40 percent of total inflow. The length of shoreline of the Bay including tributaries to head of tide, is approximately 6930 miles-about 4010 in Maryland, 2920 in Virginia. The Bay averages 28 feet in depth, making it a comparatively shallow estuary. The maximum depth is 178 feet. The surface area of the Bay is approximately 4,400 square miles, and varies in width from 4 to 30 miles. Physiographically, the Bay is the drowned river valley of the Susquehanna River. As shown in Figure 5-2, the estuary lies in the Coastal Plain and borders the Piedmont Province. The division between the upland Piedmont Province and the seaward Coastal Plain Province is marked by what is known as the Fall Line. The outcropping or exposure of the crystalline basement, which underlies the Coastal Plain to the east, forms the "line" and also delineates the head of tide. The Piedmont is characterized by metamorphic ridges and folds and steep-sided stream valleys. In general, layers of southeastwardly dipping, sedimentary, unconsolidated materials comprise the eastern and western ADnenOix 5 .. 7 HARRISBURG PC_ r-l- "00,00 y BALTIMDE000' Prok F, ft 'DOVEW"' %..I?/ A N POLIS WASHINGTON D.C DE MD V kil"-@@'ili 19 �r" IN 0 N MIS, MA@Mwl co t TI 0 ol m154-Po"3 mono f'o-Si ip", "i, olk 04" N 'M cc) @05 V!-` RICH&O IF! @n N g p .1", '41 oi -i@ -orZ 0 g v -f-- < - ys,- FIGURE 5-2 The Chesapeake Bay Rergion Appendix 5 8 shore portions of the Coastal Plain. By virtue of its very nature, the Coastal Plain is predominately flat, being somewhat more rolling on the Western Shore than on the Eastern Shore. The underlying sedimentary deposits provide plentiful groundwater supplies to public systems, industries, and individuals throughout the Province. The Bay Area is characterized by a mild climate, associated with its proximity to the Atlantic Ocean. The annual average temperatures vary between nearly 60' F at the mouth to less than 55' F at the head of the Bay (about 200 miles north). Rainfall averages 44 inches with local variations of from 40 to 46 inches per year. Included in this total rainfall is the water equivalent of an average 13- inch snowfall. RESOURCES As a water resource, the Chesapeake Bay provides many benefits for mankind. Typical among these are the fish and wildlife resources-a part of the earth's ecosystem to which man is inexorably linked; recreation opportunities which provide needed respites from everyday pressures; navigation channels which provide for the economic growth and vit 'ality of the region; and water supply to satisfy the many requirements of a "thirsty" society. In 1970 the navigation arteries of Chesapeake Bay and its tributaries carried nearly 150 million tons of commerce worth billions of dollars. The importance of this *ctivity to the economic structure of the Bay area is thus underscored- especially for the ports of Hampton Roads and Baltimore. These two parts together handle 83 percent of the Bay's commerce. The growing industrial activity associated with port related development has also created large demands for processing and cooling waters. The fish and wildlife resources of the Chesapeake Bay Area are many and varied. The Bay is one of the most productive estuaries on earth due to its wetland marshes, shallow nature, tidal actions, and wide salinity variations. Including land dwellers, the Bay Area provides habitat for over 2,700 species. Great amounts of seafood are harvested commercially, accumulating to 630 million pounds worth $41 million in 1970. Sport yields of finfish and shellfish -A were of an estimated like magnitude. Many of the fish and wildlife resources are sensitive to the alterations in salinity patterns that can result from changes in the freshwater inflows to the estuary. In this regard the use of the freshwater tributaries of the Bay for water supply may have a significant impact on fisheries. Appendix 5 The primary mineral resources found in the area are non-precious as well as non-metallic-primarily sand, gravel, stone, clay. These provide building stone and important manufacturing components for brick, pipe, and other building materials. Certain problems are associated with retrieval of these materials. In the area of water supply, for example, sedimentation and turbidity can accompany riverbed dredging for sand and gravel deposits and degrade downstream water supplies. Land mining may result in scarred, erodable, barren areas which allow increased land runoff, decreased groundwater recharge, and other problems such as acid mine drainage. These problems may be troublesome to water supplier. The Ches apeake Bay also serves as a vast waste assimilator for the activities of the over 8 million Bay Area residents. Municipal, industrial, agricultural, and power heat discharges are increasing along with the population, especially in the urban centers. Presently, most waste discharges and water quality problems in the Bay Area are assimilated and/or confined to the tributary areas. Here, especially in areas of heavy industry, the bottom muds contain massive concentrations of oils, phenols, heavy metals, and other toxic substances. Many acres of shellfish beds are closed for health reasons in areas of heavy waste discharge, as are recreation areas for bacterial pollution. Water quality is a major concern of the supp *ly manager in the design and operation of water treatment facilities in the Bay Region. Most of the land resource of the Bay Area is considered undeveloped-only 5 percent is devoted to residential, commercial, and industrial activity. Most development is concentrated in the urban centers. Agricultural activities comprise another 30 percent, while woodlands add nearly 50 percent to the land account for the Bay Area. Future patterns that emerge in the use of land will invariably impact dramatically on other resource categories, including water supply. The Bay also provides for other needs of the people, the value of which are difficult to evaluate. Recreation, for example, aside from the benefits from marinas, boat sales, and hunting licenses and equipment, provides people with relaxation and a peace of mind that is impossible to quantify. There is an undoubtable !pleasure to be derived in just being in a natural area undisturbed by the activities of man. Consideration must also be made for these more intrinsic values, so that development or use of a water resource does not impact critically on other uses. Appendix 5 10 HISTORY Until the early part of the 19th century, water was generally provided by each individual according to his needs. The country was predominantly rural and supplies of groundwater were readily available. Even in the cities, most homes were supplied by springs or wells-through hand pumps in the kitchen or delivery by cart, sold by the bucket. The earliest municipal water-works system did not appear until early in the 19th century. Philadelphia was the leader in this regard. Local authorities believed that daily flushing of the streets could alleviate the yellow fever epidemics, and, as a result, water flowed from the Schuylkill River to the City in 1801. As in Philadelphia, other cities were motivated less by a desire for A@ household convenience than by the threats of disease and fire. After cholera outbreaks in London were traced to the water supply in 1849, powerful impetus was placed on the cities to develop safe water supply systems. By 1860, there were 136 city water systems, including one in each of the Nation's sixteen largest cities' . Sewage disposal systems, however, numbered only ten. Water systems, proliferated, but no parallel facilities were forthcoming to deal -with the increasing waste loads. At the end of the 19th century, thousands of persons living on streets with sewers were still using old privies and cesspools. Many engineering innovations and much in the way of human acceptance were lacking'@@bqfore the indoor flush toilet became a commonplace household item. Slowly, the evolution towards higher water consumption in the household continued. Human waste contamination of water supplies had increased, and, once the disease risk was clearly demonstrated, it became evident that expanded sewage collection and treatment were needed to protect the public health. By 1920, the mass production of enamelware and invention of the flush toilet marked the beginning of an era-the "bathroom7became an American middle class necessity. Water closets proliferated along with water-using utensils and before World War 11 large American cities had use rates four times that of comparable European cities. Today the trend towards higher water consumption continues. In the Chesapeake Bay Area, there were early advances in water supply development for public use. Baltimore's first system to supply water to the residents of the City began operation in 18072. It was operated by a private company which used the Jones Falls as a source, distributing the water Appendix 5 through wooden mains. By 1881, the system had become public and a new supply on the Gunpowder Falls had been developed. Water was transported to the City through a tunnel. Richmond was the pioneer in the Virginia portion of the Study Area, providing public service in 18303. A water-power system was devised to pump water from the James River. Albert Stein, who also engineered systems for Cincinnati and New Orleans, was the innovator of the project. In the Nation's Capital, Congress, under threat of disease and fear of fire in the government buildings, approved a plan to bring water from above the Great Falls on the Potomac River 4. The plan, devised by Captain M.C. Meigs of the Army Corps of Engineers, included a 12- mile aqueduct which required ten years and many engineering achievements to complete. The project was completed with water flowing in 1853. Much of the other water supply development in the Bay Area progressed more slowly, with private wells being abandoned only recently in some metropolitan areas. It has only been in the urbanized metropolitan areas where pollution of sources, health problems, and fire threats have occurred, that major municipal systems have been required. Many rural residents, especially those using dependable groundwater sources of good quality, continue to develop and use individual systems. EXISTING PUBLIC WATER SUPPLY Of the Bay Area's 7.9 million residents, approximately 6.5 million, or 82 percent, are served by central water supply systems. These systems range in size from those serving as few as 20 persons in small developments to large municipal systems serving commercial, institutional, and industrial establishments, and millions of individuals. For purposes of this study, each of the water supply systems in the Chesapeake Bay Area that serve a population in excess of 2,500 are termed water service areas (WSA's). Together, the WSA's account for 96 percent of the water supplied and 93 percent of the population served by all the central systems. Municipal water systems provide for a variety of needs which may be generally classified as domestic, commercial, industrial, institutional, and public. In general, domestic uses include those of the household; i.e., food preparation, washing, lawn watering, and sanitation. Uses within the commercial category include restaurants, hotels, laundries, and car washes; while hospitals, schools, and country clubs are classified as institutional. Public uses include fire protection, street cleaning, and government buildings and institutions. ADpendix 5 1? Industrial water supply uses can be classified as process, boiler feed, cooling, and sanitary water. Depending on the extent and composition of a city's industrial makeup and the tendency for local industry to pay for and use public water, a city's industrial component of water use may vary radically. There are public water supply systems in the Bay Area that supply no water to industry and others that support an extensive industrial component. In Hopewell, Virginia, for example, industrial uses comprise 80 percent of the water publicly supplied. PRESENT WATER USE To establish a base for projection of future water needs, an inventory was made of public water supply systems, their present population served, and the average water use. The results of the inventory are presented in Table 5-1 for the 49 identified water service areas in the Chesapeake Bay Area. Plates 5-1 through 5-4, located at the rear of the appendix, show the location of each of these service areas. Water supply data for each system were derived primarily from State Department of Health records, County water and sewer reports, and other local and regional plans. Interviews with individuals at the local level were also helpful in gaining additional data. Wide variations in per capita use rate are evident among the systems listed in Table 5-1. Lows of 50 to 80 gallons per capita per day (gpcd) are found at King's Height, Joppatowne, and Waldorf, in Maryland, and Manassas Park in Virginia. Communities with low use rates are typically more residential in character, providing smaller amounts of water for industrial, commercial, and/or institutional needs. Use rates exceeding 150 gpcd occur in a number of cities: Cambridge, Crisfield, Salisbury, Leonardtown, Seaford, Baltimore, Washington, Hopewell, and Williamsburg. These high use rates can be attributed to several factors, not always consistent from system to system. For example, Hopewell's astonishing 689 gpcd is due to an estimated 22 mgd supplied to several large industries. Significant industrial uses also contributes to the high rates at Cambridge, Salisbury, and Baltimore, while institutional and military demands and tourism, contribute to the higher than normal use at Williamsburg. In contrast, the extensive government activity and array of public facilities in Washington, D.C., cause use rates in the Washington aqueduct service area to be among the highest in the Bay Area. Another component of water use in most systems is leakage. In Crisfield, Maryland, for example, losses due to leakage constitute an unusually high 25 percent of the overall use. Most of the remaining public systems (listed in Table 5-1) have use rates that would be expected from an average amount of residential use and the concomitant mix of other uses (approximately 80 to 150 gpcd). Annendix 5 1,1 TABLE 5-1 MUNICIPAL. 14ATER@ USE, 1970 Subregion and Population Average Per capita Water Service Area Served, 1970 Use, mgd Use, gpcd SUBREGION 1 Aberdeen 12,400 1.2 98 Annapolis 40,000 4.3 108 Baltimore 1,542,160 245.0 159 Bel Air 10,200 1.0 98 Crofton 6,280 0.8 127 Edgewood (Perryman) 7,800 1.2 154 Havre de Grace 10,000 1.55 155 Joppatowne 8,060 0.62 77 Maryland City 4,400 0.60 136 King's Heights (Odenton) 7,900 0.53 67 Severna Park (Severndale) 15,580 1.8 115 Sykesville-Freedom 7,500 0.6 80 Westminster 11,000 1.1 100 SUBTOTAL 1,673,820 260.3 156 SUBREGION 2 Cambridge 12,600 3.85 305 Centreville 2,800 0.28 97 Chestertown 4,000 0.53 132 Crisfield 4,040 1.37 339 Annendix 5 14 TABLE 5-1 (continued) MUNICIPAL WATER USE, 1970 Subregion and Population Average Per capita Water Service Area Served, 1970 Use, mgd Use, gpcd SUBREGION 2 (Cont'd) Delmar 3,000 0.30 100 Denton 2,700 0.39 144 Easton 7,800 1.00 128 Elkton 8,500 1.00 118 Pokomoke City 3,330 0.30 90 Princess Anne 2,500 0.22 88 Salisbury 19,000 4.00 210 Snow Hill 3,000 0.47 157 SUBTOTAL 73,270 13.a 188 SUBREGION 3 no large public systems SUBREGION 4 Seaford 5,540 0.84 153 SUBREGION 5 Washington Suburban Sanitary Commission 1,130,000 124.0 110 Washington Aqueduct 1,033,000 200.0 193 Alexandria 110,000 13.0 118 Fairfax County Water Authority 370,000 36.5 99 Appendix 5 15 TABLE 5-1 (continued) MUNICIPAL WATER USE, 1970 SiL!bregion and Population Average Per capita Water Service Area Served, 1970 Use, mgd Use, gpcd SUBREGION 5 (Cont'd) Goose Creek (Fairfax City) 65,000 7.1 109 Manassas 11,500 1.25 109 Manassas Park 7,000 0.35 50 SUBTOTAL 2,726,500 382.2 140 SUBREGION 6 Leonardtown 2,500 0.38 152 Lexington Park 10,000 1.00 100 Waldorf 10,000 0.80 80 SUBTOTAL 22,500 2.18 97 SUBREGION 7 Fredricksburg 19,530 2.6 133 SUBREGION 8 Ashland 3,750 0.35 93 Colonial Heights-Petersburg 67,000 7.10 106 Hopewell 37,440 25.80 689 Mechanicsville 2,880 0.28 100 Richmond System 390,620 41.10 105 SUBTOTAL 501,690 74.6 149 Appendix 5 16 TABLE 5-1 (continued) MUNICIPAL WATER USE, 1970 Subregion and Population Average Per capita Water Service Area Served, 1970 Use, mgd Use, gpcd SUBREGION 9 West Point 2,600 0.26 100 SUBREGION 10 Newport News System 263,266 27.3 104 SUBREGION 11 Norfolk System 509,680 52.5 103 Portsmouth System 123,960 13.7 ill SUBTOTAL 633,640 66.2 104 SUBREGION 12 Williamsburg 16,500 2.50 151 Smithfield 2,710 0.28 103 Suffolk 18,000 1.80 100 SUBTOTAL 37,210 4.58 123 BAY AREA TOTAL 5,959,560 831.2 139 V Apnendix 5 17 In addition to the "large" water supply systems, defined as serving a population of 2,500 or greater, a certain number of smaller public systems exist in the Bay Area. The aggregated population served by the "small" systems for each county was derived from records of the various state departments of health. Table 5-2 lists the total for each county. In addition to those persons that receive their water through public water supply systems, many rural residents derive their water from private wells or other local sources. The water needs of the rural domestic population is presented, along with irrigation and livestock requirements, in Appendix 6 - Agricultural Water Suppkv. A summary of rural domestic, livestock, and irrigation water use is presented in Attachment 5-F. Y, EXISTING PROBLEMS AND CONFLICTS Provision of water for the people of the Bay Area is not accomplished without the water supplier encountering certain problems. Growing affluence and economic development, and the accompanying increased demands for water have required local water authorities to expand treatment and distribution facilities and to search for new sources. In most urban areas, nearby local sources have been completely developed and cities have been searching further and further afield for new supplies. The City of Norfolk, for example, pipes raw water 25 miles from Lake Prince and also maintains a supplementary source on the Nottoway River, which is 50 miles distant. The Newport News water supply network extends 20 miles from the city proper and Baltimore's aqueduct from the Susquehanna River spans 38 miles, overcoming a difference in head of more than 100 feet. Larger and more elaborate projects are certain to emerge in the future as water needs increase and competition grows for dwindling supplies. A shortage in supply is perhaps the most critical problem facing a water supply facility. The shortages become critical when periods of low strearnflow coincide with dry summer periods when consumer demand is highest. Rainfall and other hydrologic and climatic parameters influence the amount of water available in surface sources. Few of those systems that rely on surface waters can effectively develop a source that is 100 percent safe against all droughts without incurring prohibitive costs. Thus, as a matter of course, most utilities must gamble that rainfall will be adequate to replenish dwindling supplies. It is not uncommon, however, for systems dependent on groundwater to have a supply essentially independent of seasonal climatic variation. Due to the massive storage capacity and dampening effect of the aquifers, these systems can usually supply water at a constant rate through the most severe drought. Appendix 5 TABLE 5-2 SERVICE POPULATION: SMALL WATER SYSTEMS, BY COUNTY, 1970 COUNTY POP. COUNTY POP. SUBREGION I SUBREGION 8 MARYLAND VIRGINIA Anne Arundel 61,100 Chesterfield 36,400 Baltimore 0 Dinwiddie 2,400 Carroll 21,200 Hanover 6,860 Harford 12,700 Henrico 10,900 Howard 4,430 Prince George 4,800 SUBREGION 2 SUBREGION 9 MARYLAND VIRGINIA Caroline 4,990 Caroline 1,900 Dorchester 9,050 Charles City 0 Kent 2,370 Essex 3,190 Queen Armes 100 King & Queen 190 Somerset 780 King William 950 Talbot 3,340 Lancaster 5,100 Wicomico 1,740 New Kent 1,700 Worcester 12,600 Northumberland 4,050 Cecil 21,300 Richmond 2,210 Westermoreland 10,000 SUBREGION 3 VIRGINIA SUBREGION 10 Accomack 5,370 VIRGINIA Northampton 4,050 York 5,370 SUBREGION 4 SUBREGION I I DELAWARE VIRGINIA Sussex 12,800 City of Chesapeake 5,110 City of Virginia Beach 3,050 SUBREGION 5 MARYLAND SUBREGION 12 Montgomery 1,550 VIRGINIA Prince Georges 650 Gloucester 2,000 VIRGINIA Isle of Wight 3,830 Fairfax 80,900 James City 5,310 Loudoun 3,390 Mathews 130 Prince William 11,100 Middlesex 1,790 City of Suffolk 6,580 SUBREGION 6 Southampton 5,520 MARYLAND Surry 940 Calvert 5,150 Charles 10,900 St. Marys 7,410 SUBREGION 7 VIRGINIA King George 3,130 Spotsylvania 4,430 Stafford 5,790 Appendix 5 19 Despoilation of sources is another major problem facing water suppliers in the Chesapeake Bay Area. Surface waters, both reservoirs and free-flowing streams, are especially susceptible to pollution. Sprawling urban developments have encroached in some watersheds, contributing to overland runoff, sedimentation, and other sources of pollution. Agricultural activity contributes to overenrichment, sedimentation, and pesticide pollution. Water suppliers that utilize run-of-the-river sources, such as Richmond on the James. River and Washington, D.C., on the Potomac, must contend with domestic and industrial waste discharge from a myriad of upstream sources. Water systems that depend on groundwater as a source of supply are also susceptible to contamination. Seepage from septic systems and landfills are notable sources of pollution in groundwater supplies, saltwater intrusion is another problem affecting some near-shore areas around the Bay. Long periods of withdrawal in excess of the natural rate of replenishment of the aquifer can cause lowering of the water table and eventual intrusion of saltwater from the ocean or other nearby saltwater body. This condition will often render the water in the aquifers unusable for years. In addition to the problems encountered by the water developer, certain conflicts and problems arise with respect to other uses and resources as a result of water supply development. Groundwater pumping, for example, may sometimes lower the water table sufficiently to reduce the quality or quantity of groundwater available in adjacent areas. For example, industrial withdrawals near the City of Franklin, Virginia, have, over man y years, caused a 150-foot decline in the water table at the point of withdrawal and created a cone of influence that affects the water table 20 miles distant at the City of Suffolk. Also, groundwater withdrawals can be ecologically damaging if the water table is lowered beneath wet environments such as bogs, causing them to lose their saturated condition. The impacts associated with development of surface waters are often more pronounced than those of groundwater development. Reservoir construction can result in direct reduction of downstream flows, and possibly impact on other downstream uses, including fish and wildlife, recreation, and waste assimilative capacity. Supersaturated gases, temperature shock, oxygen- depleted releases from the hypolimnion, and sudden releases of large volumes of water are other reservoir-related problems to consider with respect to their impact on downstream aquatic life. On the other hand, fishery resources and recreation can also be enhanced during summer months by the artificially sustained flow made possible by a reservoir. Diversion of water supplies from one watershed to another is an engineering practice that directly removes the water and reduces strearnflow by the amount wthdrawn. Baltimore City's authorized 250 mgd withdrawal from above Conowingo Dam on the Susquehanna River (at present only minimally used) Appendix 5 20 has provoked citizen concern as to potential impacts on the Chesapeake Bay fishery. Conflicts also arise in relation to water rights. In the Western United States, water rights are governed by the law of appropriation which entities a user who is first in time and who applies the water to a beneficial use to that amount of water in perpetuity. The riparian doctrine, characteristic of the Eastern States, protects adjacent landowners from uses which unreasonably diminish water quality or quantity. The problem often arises in that social and public values are neglected in favor of the economic interests of the private sector. Legislative actions are then required in order to optimize social and cultural water uses in conjunction with the conventional economic values. Impacts will naturally occur in any water resource development, but the objective should be to minimize the adverse effects to the overall net public and environmental benefit. Positive action is needed to provide a management structure so that water development, while undeniably needed for our progressing society, will not bear unduly on other uses and resources. MANAGEMENT RESPONSIBILITIES Management of water supply systems entails confrontation with the problems discussed in the previous section. In short, the management authority is charged with the responsibility to provide water of the quantity and quality demanded within the service area. A multitude of combinations of institutional and administrative arrangements are utilized in providing water for the citizens of the Bay Area. Management structures, set up to provide the needed supplies, can be privately or publicly administered, usually at the local level. Public systems are usually operated by their particular town or city government-as is the case for most of the water service areas considered in this report. Privately owned public systems are a less common means of water supply in the Bay Area. Notable examples of privately owned systems are those at Lexington Park and Bel Air, Maryland, and Alexandria and Hopewell, Virginia. Larger areas, including several communities, developments, parts of counties, or even states, may be incorporated under a regional-type authority, or commission, to manage all aspects of the region's water needs. This situation has the potential to enable efficient, safe, and economical service to a developing region-especially those with fragmented and localized source developments and conflicting wastewater control programs. The Appomatox River Water Authority and Fairfax County Water Authority are examples of State chartered regional water systems with authority to acquire, construct, operate, and maintain water systems within particular regions. Sometimes these written authorities are extended to include wastewater collection and disposal. Ay..)pendix 5 21 A unique arrangement for water supply exists in Washington, D.C. Due to its status as the Nation's Capital, water supply is, by law, the unique management responsibility of the Federal Government, specifically the U.S. Army Corps of Engineers. Through its Washington Aqueduct Division, the Corps is responsible for raw water transportation and treatment of water for the many residents, public institutions, and government facilities in Washington, D.C., Falls Church, and Arlington County, Virginia. In addition to specific management structures, various health related, and financial and planning assistance programs are available at the state and Federal level to aid in the development and/or management of 'water supply resources. At the state level, for example, the District of Columbia, Maryland, Virginia, and Delaware Departments of Health have the responsibility under law for maintaining the health integrity of all public drinking water supplies. Consultation services to local public service agencies are also generally available through the Health Departments, as are planning and associated environmental services. Responsibility for the overall water resource management is held at the state level by the following agencies: ( � State Water Control Board in Virginia � Department of Environmental Services in Washington, D.C. � Department of Natural Resources in Maryland � Department of Environmental Resources in Pennsylvania � Department of Natural Resources and Environmental Control in Delaware Generally the scope of these agencies' authority includes planning, program development, regulation, enforcement, and provision of other public services as regard water resources. As stated in the Department of the Army's Digest of Water Resources Policies, the Federal interest in water supply and quality management seeks to "insure a continuing supply of freshwater, adequate in quantity and quality for urban and rural withdrawal and streamflow needs." In practice, however, the policy of the Federal Government has been toward the long range management of supplies, leaving the financial burden of supply to the user. For example, if all costs allocated to water supply are paid by non-Federal interests, the Corps of Engineers has the authority, pursuant to the Water Supply Act of 1958, to include municipal and industrial water supply in any of its reservoir projects. Costs allocated to water supply cannot ordinarily exceed 30 percent of the total project cost, but, if such storage is economicallyjustified, it may be added to any project at any time. Under certain conditions, storage for irrigation on Appendix 5 22 agricultural lands may also be considered as a purpose in Corps dams, but under present interpretation, this applies only to certain western states. Federal level financial assistance is available for rural community water supply development and planning from the Farmer's Home Administration (FHA) of the U.S. Department of Agriculture. Services that are water supply related, (such as watershed and wastewater facilities, financing, and planning,) are also available to the rural areas through FHA. Federal assistance can also be sought in water supply development from the Soil Conservation Service (SCS), U.S. Department of Agriculture, but only as it relates to watershed or flood protection. Under certain cost-sharing and other conditions, water supply storage can be included as a purpose in SCS dam projects. Lastly, the Environmental Protection Agency has public health oriented assistance programs for use by public water utilities. These programs are designed to promote highly reliable, quality supplies through research grants and technical assistance. EXISTING INDUSTRIAL WATER SUPPLY The industrial component of the 1970 water demands in the Chesapeake Bay Area is considered in this section. Only the water supply needs of the manufacturing industries are addressed here, including those industries in Standard Industrial Classifications (SIC's) 20 through 39 (as defined by the Federal Office of Management and Budget). Manufacturing activity in the Chesapeake Bay Area is dominated by Primary Metals (SIC 33), Paper (SIC 26), Chemicals (SIC 28), Petroleum (SIC 29), and Food and Kindred Products (SIC 20). Other industrial sectors, such as Finance, Transportation, Services, and Government, are not included in this analysis, as their water demands generally comprise a portion of the public supply. As noted earlier cooling water needs for power generation, which constitute a major sector of demand, are presented separately in Appendix 13: Power. In general, industrial uses of water can be classified as process, boiler feed, cooling, and sanitary. Quality requirements vary widely depending on these uses, and although generalizations for a particular industry and type of use are difficult to make, some observations can be made. For example, low hardness is desirable for canning peas, and low chlorides are critical in the paper bleaching process 6. In some industries, such as Paper, Chemicals, and Textiles, even the smallest trace of any element such as manganese can make the process impossible 7. Within an industry, variables in quality requirements Appendix 5 23 also occur. In the Paper sector, for example, photographic paper and cardboard have radically different requirements. Cooling water, used in condensing and cooling equipment and for quenching in steel roller mills, can be of almost any quality. For instance, Baltimore City provides about 120 mgd of its treated municipal waste effluent to the Bethlehem Steel Corporation for cooling purposes. Much of the other cooling water withdrawals in the Bay Area are derived from brackish sources, defined for purposes of this report as all waters containing greater than 1,000 ppm dissolved solids. Ideally, cooling water is of low temperature, turbidity, and scale-forming materials, especially if it is to be recycled. Boiler feedwater requires perhaps the most stringent quality control. Only small amounts are needed to replenish that evaporated, but soft water is needed to avoid scale buildup, especially in high-pressure boilers. Water used to meet sanitary needs of industry (toilet facilities, etc.) must, naturally, meet the same drinking water standards as those for municipal supplies. An important concept in industrial water supply is water recycling or reuse. Since large amounts of water can be reused in many industrial processes, significant savings could be realized if this practice was more widely used. The tendency of an industry to recirculate water usually depends ultimately on economics. Water will be reused in a particular situation if the costs of recovery and recirculation are less than costs associated with the development of additional sources, or the costs of treatment of the wastewater. In locations where fresh water is scarce or where quality problems require extensive treatment, recirculation may be heavily utilized. Conversely, in areas with plentiful supplies of high quality water, or where wastewater treatment costs are low, reuse is usually uneconomica120. Efforts to comply with discharge regulations or to reclaim byproducts have in some instances prompted development of equipment to make recirculation more economical. For example, in the pulp and paper industry, development of special filters to remove small amounts of waste fibers from large amounts of water has enabled large recirculation rates in many plantS21. Certain other advances in technology serve to illustrate measures that can result in expanded recirculation practice. In many instances, forced air cooling towers have.replaced natural draft systems, speeded evaporation and reduced the overall size and cost of recirculation systeMS22. Sequential use of water for cooling in several processes, at gradually increasing temperatures, has also been used to advantage. In steel mill, for example, the Appendix 5 24 coldest water can first be used in the power plant condensers, reused to cool process equipment (operating at 100 to 3001 F), and again reused for cooling burner ports or furnace walIS23. Also, development of new ceramic and alloy materials to withstand high temperatures in industrial processes has enabled use of air cooling techniques where water was previously needed to minimize equipment damage24. PRESENT INDUSTRIAL USE Industrial water use in 1970 was inventoried by the Bureau of Domestic Commerce (BDC), U.S. Department of Commerce. With the aid of the Bureau of Census, data were accumulated Nationwide for industries utilizing 10 Ir million gallons per year (mgy) or more. Data accumulated include: identification of the type of industry based on 4 digit SIC identification, intake (mgy), gross use (mgy), source, employment, treatment, and discharge. For those plants that utilize more than 10 mgy and did not respond to the survey, information was obtained from the permit applications submitted for discharge permits under the 1899 Refuse Act, from industry directories, and from discussions with BDC industry experts. For the manufacturing plants with intake requirements of less than 10 mgy, total withdrawal demands were estimated through the use of water use ratios reported in the 1963 Census of Manufacturers and estimates of future subregional shares of Gross Product Originating (GPO). Results of the inventory of industrial water use in the Chesapeake Bay Area are presented in Table 5-3. Due to agreements between the Department of Commerce and the industries participating in the survey, data is not to be released in detail, but is available only on a subregional basis (SMSA and non- SMSA county grouping), as delineated previously in Figure 5-1. For this reason, all tables of industrial water use in this report (except as specifically noted otherwise) include Kent County, Delaware, as part of Subregion 4, ir. addition to Sussex County, Delaware. Water use in manufacturing by 2-digit SIC is presented in Table 5-4. Gross use (G) includes all water used, whether fresh, brackish, or recirculated. Intake (1) represents only the actual withdrawal from stream or bay, or other fresh or brackish water source, plus purchases. The consumption category (C) includes all water lost to evaporation or that becomes incorporated into end products. Discharge (D) is merely the difference between intake and consumption (I - C). The final column lists the percent of the gross use that is recycled water [ (G-I)/Gl As shown in Tables 5-3 and 5-4, total intake from fresh and brackish sources totaled 1,615 mgd mi 1970. Ninety-nine percent of this water was used by only 3 percent of the manufacturing establishments which have demands in excess of ADDendix 5 25 TABLE 5-3 INDUSTRIAL WATER USE IF THE CHESAPEAKE BAY AREA, 1970, mgd G-Il Subregion Gross Use (G) Intake (1) Consumption(C) Discharge(D) G 1 Baltimore SMSA 1,226.1 990.7 43.7 947.0 19.2 2 Non-SMSA, ND 35.5 34.8 0.9 33.9 1.9 3 Non-SMSA, VA 2.6 2.3 0.2. 2.1 11.5 4 Non-SMSA, DE 2 82.7 65.6 1.9 63.7 20.7 5 Washington SMSA 5.4 4.7 0.2 4.5 13.0 6 Non-SMSA, MD 0.8 0.8 0.1 0.7 0.0 7 Non-SMSA, VA 32.9 27.4 1.8 25.6 16.7 8 Richmond and Petersburg SMSA's 400.5 286.8 14.0 272.8 28.4 9 Non-SMSA, VA 52.4 26.5 5.0 21.5 49.4 10 Newport News- Hampton SMSA 114.9 100.2 0.7 99.5 12.8 11 Norfolk- Portsmouth SMSA 32.3 25.3 1.3 24.0 21.7 12 Non-SMSA, VA -621.8 50.4 4.8 45.6 91.9 TOTAL BAY AREA 2,607.9 1,615.5 74.6 1,540.9 38.1 1 G-I = Percent recycled. G 2includes Kent Co., Delaware Appendix 5 26 TABLE 5-4 WATER USE IN MANUFACTURING, BY SECTOR, CHESAPEAKE BAY AREA, mgd G-I Gross Use Intake Consumption Discharge G All Manufacturing 2,607.9 1,615.5 74.6 1,54o.9 38.1 Food & Kindred Products 79.7 74.3 5.6 68.7 6.8 Paper & Allied Products 644.8 72.8 7.6 65.2 88.7 Chemicals 402.5 328.1 14.5 313.6 18.5 Petroleum 81.6 76.3 0.7 75.6 6.5 Primary Metals 1,094.6 882.3 35.1 847.2' 19.4 Other Manufacturing 304.7 181.7 11.1 170.6 40.0 ADnenOix 5 27 10 million gallons per year (mgy). These plants, which, for the purposes of this study, are termed the "large water users," represent 190 of the 5,800 individual manufacturing establishments in. the Bay Area. Thus, most of the plants for which data are aggregated here are small with respect to the amount of water used. Most are also small in terms of employment and production. In addition to the concentration of water use among a relatively small number of plants, there is also a concentration of water use within particular types of industries. In the Chesapeake Bay Area, 82 percent of the total water used is accounted for by three groups of industries: SIC 26, Paper and Allied Products; SIC 28, Chemicals and Allied Products; and SIC 33, Primary Metals, as shown in Table 5-4. Recirculaton of supplies is practiced by some industries to conserve water, meet discharge requirements, or, often, to recover components in the wastewater. A measure of the degree to which recirculation technology is utilized in each subregion is shown in the final column of Table 5-3, and for each major type of industry in Table 5-4. The best recycling efficiency occurs in the paper industry in which 88.7 percent of the gross water used is recycled. In other words, nearly nine times as much water would be needed from the river, or other source, if recirculation was not practiced-645 vs. 73 mgd, on the average. Of the major industries in the Bay Area, the Petroleum industry recycles least, primarily due to the once-through use of brackish water for cooling. However, National figures for Petroleum indicate recirculation at least 10-fold that in Chesapeake Bay. Water withdrawals, categorized as to source, are shown in Table 5-5. The total amount withdrawn in 1970, is estimated to have been 565,355 mgy, or an average of 1,615 mgd (assuming a 350 day work-year). Sixty-one percent of this is used in the Baltimore SMSA alone with the Richmond and Newport News SMSA's following with 18 and 6 percent, respectively. In contrast to the Nation as a whole, in which approximately 75 percent of industrial supplies are obtained from freshwater sources, only about 37 percent of all Bay Area industrial withdrawals are from freshwater sources. Table 5-6 details the National breakdown of industrial water use by source versus that in the Bay Area. Brackish use is shown to constitute a major portion of industrial use in the Bay Area. Because many plants are located on, or in close proximity to the Bay, brackish water is substituted for certain operations. The total quantity amounted to an average of 899 mgd (315 bgy), or 56 percent of all withdrawals in manufacturing in 1970. Nationally, only about 18 percent of industrial withdrawals are brackish. Aloperdix 5 28 TABLE 5-5 INDUSTRIAL WATER WITHDRAWALS, BY SOURCE, MGD CHESAPEAKE BAY AREA, 1970 Self-Supplied Total Percent Subregion Public Ground Surface Brackish Other Total Fresh Fresh I Baltimore, SMSA 70.0 14.4 2.9 781.2 122.2 990.7 87.3 7.8 2 Non-SMSA, Maryland 3.0 30.0 1.1 0.7 0.0 34.8 34.1 97.9 3 Non-SMSA, Virginia 0.3 1.9 0.0 0.1 0.0 2.3 2.2 95.7 4 Non-SMSA, Delaware' 2.7 14.9 48.0 0.0 0.0 65.6 65.6 100.0 5 Washington SMSA 3.3 0.1 1.3 0.0 0.0 4.7 4.7 100.0 6 Non-SMSA, Maryland 0.1 0.7 0.0 0.0 0.0 0.8 0.8 100.0 7 Non-SMSA, Virginia 0.2 0.1 27.1 0.0 0.0 27.4 27.4 100.0 8 Richmond SMSA 22.3 0.3 264.2 0.0 0.0 286.8 286.8 100.0 (also Petersburg) > 9 Non-SMSA, Virginia 0.2 16.0 0.1 10.3 0.0 26.6 16.3 61.3 10 Newport News SMSA 4.6 5.0 0.0 90.6 0.0 100.2 9.6 9.6 (D "o 01 11 Norfolk SMSA 5.6 3.8 0.0 15.9 0.0 25.3 9.4 37.1 F1 x 12 Non-SMSA, Virginia 0.6 44.9 4.8 0.0 0.0 50.3 50.3 100.0 @.n TOTAL BAY AREA 112.7 132.1 349.5 898.8 122.2 1615.5 594.5 36.8 includes Kent Co., Delaware TABLE 5-6 WATER USE IN MANUFACTURING, NATIONAL COMPARISON, BY USE (Billion gallons per year, percent) Total Surface Intake Public Ground Fresh Brackish Nationally' 15,024 1,649 1,653 9,042 2,671 100.0% 11.0% 11.0% 60.2% 17.8% Chesapeake Bay 5652 39 46 122 315 Study Area, 1970 100.0% 6.9% 8.1% 21.6% 55.8% 1 From Census of Manufacturers, 1972 10 2 Includes wastewater reuse (7.6 percent of intake). Perusal of Table 5-5 reveals water use characteristics which are often peculiar to the individual subregions. Industrial water use in Subregion I (Baltimore), for instance, is derived predominantly from brackish sources and is used for cooling purposes. While self-supply is the general rule in most of the Study Area, 80 percent of the freshwater in Subregion I is provided through public systems, particularly the Baltimore City System. Also of interest is the reuse of about 120 mgd of treated municipal waste by the Bethlehem Steel Corporation. This comprises an extraordinary 7.6 percent of the Bay Area's total industrial intake. Water used for manufacturing purposes on the Delmarva Peninsula (Subregions 2, 3, and 4) is dominated by the food processing industry. In Subregion 2, Food accounts for 50 percent of industrial withdrawal,. and Chemicals (SIC 28) an additional 24 percent9. Industrial water use in Subregion 3 (Eastern Shore, Virginia) is predominantly in Food industries. Subregion 4 (lower Delaware) supports large water using industries in the Food and Chemical sectors. Although marked quantities of surface water are used in Subregion 4 (when compared with other Eastern Shore areas), supplies are generally derived from the plentiful Coastal Plain groundwater resource. Manufacturing water use is small in most of the Washington Economic Area (Subregions 5, 6, and 7). Industrial activity in Subregion 5 (the Washington, D.C. SMSA) is dominated by the governmental and service-oriented sectors, and, as such, there is little water use in manufacturing. For the non-SMSA area in Maryland (Subregion 6), water use is concentrated in Food and Lumber) 1. These three counties rely almost entirely on groundwater, but in Subregion 7 (Virginia), 99 percent of withdrawals are fresh surface water. Ninety-five percent of usage in Subregion 7 is by the FMC Corporation at Fredericksburg (SIC 28)12, which withdraws water. directly from the Rappahannock River. Appendix 5 30 Moving southward in the Chesapeake Bay Study Area to the vicinity of the James River, marked increases are observed in industrial water uses, as shown in Table 5-5. 'The Richmond SMSA (Subregion 8) contains a heavy concentration of Chemical industries. Five large plants in Hopewell and Chesterfield Counties account for 72 percent of the subregional industrial use (about 200 mgd). Paper manufacturing ranks second, constituting an additional 9 percent of the overall intake. The primary source of supply in the Subregion is fresh surface water from the James River. Industrial water use in predominantly rural Subregion 9 is dominated by the Chesapeake Corporation (SIC 26) at West Point, which uses 95 percent of all industrial withdrawals in the area. Of note is the effective recirculation technology used by the plant which cuts withdrawal demand by 50 percent. Industrial water use in the balance of the area is light. The dominant source of supply is from wells. Industrial withdrawals in the Newport News-Hampton SMSA (Subregion 10) are approximately 90 percent brackish. About 80 percent of this, or 71 mgd, is used by the American Oil Company at its Yorktown refinery13. In the Norfolk SMSA (Subregion 11), manufacturing usage is again primarily brackish, constituting 63 percent of withdrawals. Public supplies account for an additional 22 percent. Fertilizers and other chemical manufacturing industries use over 40 percent of the subregional industrial water supply. Subregion 12 is the final area under consideration. Usage in the Subregion amounted to 50.3 mgd, of which 76 percent was employed in paper manufacturing. Groundwater supplies nearly 90 percent of the industrial demands of the area. The Union Camp Corporation alone accounts for groundwater withdrawals of 38.4 mgd from the Potomac Aquifer near Franklin, Virginia14. EXISTING PROBLEMS AND CONFLICTS Certain problems and conflicts arise when different interests are competing for use of the same resource. From the point of view of the water supply manager, for instance, there are insufficient controls and institutional arrangements to regulate the effects of upstream users on those downstream. Waste discharges and consumptive losses have traditionally occurred without regard to downstream uses, such as recreation and fish and wildlife, as well as additional public and industrial needs. The downstream users must subsequently contend, at some expense, with the polluted and/ or depleted supplies. All told, some of the costs of providing goods and services to the people must be borne by society and the environment at large. Polluters use the free resource and leave the problem-costs are borne by subsequent users or uses. Appendix 5 31 Water quality standards drawn up at the state level, and Federal goals set forth in the 1972 Amendments to the Water Pollution Control Act, have the potential to somewhat equalize the costs between initial and fin@l users along a watercourse. Higher treatment levels and/ or increased recirculation and reuse in the manufacturing sector have already improved stream quality in some areas and to some extent have had the effect of redistributing costs back to dischargers. Continuing advances toward established water quality goals and new institutional arrangements will be needed to enhance our waterways in the interest of all users. Other problems and conflicts discussed previously in conjunction with public water supply apply equally well here, as regards industrial water supply. For example, excessive groundwater withdrawals which deplete the surrounding aquifer and encourage saltwater intrusion, and depletion of surface water flows by diversion or lack of rainfall are typical problems encountered by water suppliers. In turn, pollution and/or depletion of available water flows, resulting from water supply development and use, will sometimes adversely affect other resources, including fish and wildlife, recreation, and the assimilative capacity of streams. MANAGEMENT RESPONSIBILITY Management responsibility for industrial water supply usually rests with each particular manufacturer. Managers are left to their own devices to seek out the sources that most economically satisfy their particular quantity and quality requirements. Often, if only a relatively small quantity of water, or water of a particular quality, is needed, a public water supply may be an industry's most economical water source. In this case, management responsibility falls to the public water utility. Management responsibilities of the many water supply related state and Federal agencies have been previously discussed in the "Public Water Supply" section. These apply equally as regards industrial water use activities. SUMMARY A summary breakdown of existing freshwater use, by type, is presented in Figure 5-3. Included are average water uses for public systems, self-supplied domestic needs, agriculture (livestock, poultry, and irrigation), and self- supplied industry (including wastewater reuse). The segment that represents agriculture in the diagram includes the irrigation requirement as an annual average during a normal precipitation year. The total amount of water represented in the chart is 1,568 mgd. It should be noted that brackish water Appendix 5 3-) use, which in 1970 averaged about 899 mgd, is not accounted for in the diagram. Water requirements for cooling in the generation of electric power are also not included here, but are addressed in full in Appendix 13: Power. Small public systems (2.3%) Rural domestic (4.0%) Agriculture (2.2%) LARGE PUBLIC SYSTEMS (53.0%) SELF-SUPPLIED INDUSTRIAL (38.5%) FIGURE 5-3: ANNUAL AVERAGE FRESHWATER USE BY TYPE, 1970 ADDendix 5 33; CHAPTER III FUTURE WATER SUPPLY NEEDS This chapter is devoted to a projection of future municipal and industrial water supply needs in the Chesapeake Bay Area. For purposes of this analysis projections were made through the year 2020 for: a. All persons served by central water supply systems b. All manufacturing industries. Also contained in this chapter is a presentation of the capacities of the existing water supply systems and sources that provide service to the major centers of population in the Bay Area. Potential future water supply deficits for these central systems were computed by comparing projected future water supply demands with the yield of presently developed sources and the capacity of existing water treatment plants and pumping facilities. Appendix 6: Agricultural Water Supply, contains the complete methodology and projections of agriculture related water demands, including the quantities of water needed to service livestock, irrigate crops, and fulfill the domestic requirements of those persons residing in rural areas that are not served by central water supply systems. Water supply requirements for use in cooling of electric power generating equipment are presented in Appendix 13: Power. The assessment of the water supply situation for communities which are served by central systems is relatively straightforward. The geographic locations of both the supply source and the demand center are specifically defined and comparisons can be readily made of expected water use and the capacity of existing sources and systems. It is considered to be a safe assumption that future population and economic growth will continue to occur predominantly around the existing urban centers. Except in very isolated instances, however, it is difficult to predict specific future water supply demands for industry and agriculture in terms of specific sources of supply. It was not considered practical, therefore, to be site-specific in projecting the future water supply demands in agriculture as presented in Appendix 6, nor the self-served industrial water supply demands presented herein. Rather, needs of this type have been aggregated and presented as a total for each subregion. The subregional delineations, as shown earlier in Figure 5-1, are the Standard Metropolitan Statistical Areas (SMSA's) and the non-SMSA county _groupings as defined by the U.S. Bureau of Census. It is also of importance to note that all economic projections made by the Department of Commerce for this study are based on the same subregions. Appendix 5 35 In order to assess the capability of the entire freshwater resource of the Chesapeake Bay Area to meet possible future water supply demands, a comparison was made between an estimate of the freshwater available in each subregion and the aggregated water supply demand for each subregion. The total demand was determined by combining the agricultural institutional and self-served industrial water supply demands with the demands generated in areas served by central systems. Possible future deficits were then computed by comparing the total water supply demand with the present yield of all possible water supply sources in the subregion. Types of sources considered include groundwater aquifers, surface streams with significant flows, existing reservoirs, and pipelines importing water from other regions. Brackish water also comprises an element of supply in the Chesapeake Bay Area. Within some of the manufacturing industries, water of this type (with dissolved solid in excess of 1000 mgl) is acceptable for use in once-through cooling processes. Although the assessment of future needs presented in this Chapter are in terms of freshwater demands, and freshwater supplies, projections are also included for the brackish water demands in manufacturing. MUNICIPAL WATER SUPPLY DEMANDS As shown in Chapter 11, water supplied through large public systems in the Bay Area amounted to about 831 mgd in 1970. Based on projections of population and economic development in, the Bay Area, requirements for water to be served through these public systems will more than double by the year 2000. This section presents the assumptions and methodology used in the projection of the public water supply demand and a detailed presentation of results. The quantity, of water used by a municipality is a function of a variety of factors. Of particular significance are population, population density, per capita income, the quality of the water, the price of the water, whether or not it is metered, and the number and types of industries, commercial establishments, institutions, and office complexes involved. A myriad of these and other factors account for the wide variations in use rate evident in Table 5-1: from lows near 60 gpcd to highs of almost 200 gpcd. With the passage of time, changes in any one or a number of these factors may occur which will have a direct influence on the quantity of water used within a community. Therefore, in order to forecast expected water demands, it is desirable to analyze each of these parameters in the context of the future. It is well recognized, however, that scientific methods are not available which will ADvendix 5 36 yield exact answers as to the future. Rather, forecasting is normally accomplished by applying accepted methodologies to a formulated set of assumptions on future trends. It is important for those in water resource management positions to be fully aware of the implications of these assumptions when decisions are made in which the magnitude of a future water demand is a significant factor. An analysis of the effects that certain changes in the basic assumptions may have on the future water supply demand is presented in Chapter IV (Sensitivity Analysis). Included is an analysis of alternative population projections in terms of the effect these alternative projections may have on public water use. In addition, Chapter V (Means to Satisfy the Needs), contains an analysis of certain other variables that affect water use in public systems, such as pricing and metering, to demonstate how they might be used as tools to control demand growth. ASSUMPTIONS Certain assumptions are used in this study in the derivation of municipal water supply demands. The most basic assumptions, which concern population growth, increases in per capita water use, and the industrial portion of public supply in each community, are as follows: a. OBERS projections, Series C, reflect future economic and demographic trends for the Bay Area; b. The service population in each of the water service areas will remain as a constant proportion of the projected census population; c. The 1970 per capita use rate for each water service area, for non- industrial uses, is related to per capita income (see Figure 5-4). d. The per capita use rate (referred to in "c" above) will grow at gradually reducing rates as illustrated in Figure 5-5; (this is based on a 3 percent annual growth rate at 40 gpcd, I percent at 80 gpcd, and one-half percent at 150 gpcd); e. Publicly supplied industrial water us,@ in each community will remain as a constant proportion of the subregional total industrial water publicly supplied (see next section for additional assumptions regarding industrial water demands.) Appendix 5 37 f. Small centralized water supply systems, which are defined as serving fewer than 2,500 persons, have an initial non-industrial use rate of 85 gpcd. Other factors which influence a community's demand for water, such as social taste, community character, and public policies, with respect to water use and development, are not directly addressed in the projections presented in this chapter. Forces within society which tend to influence changes in the magnitudes and types of water use within the cities are assumed to remain constant throughout the study period. However, an analysis of the possible influence on water use that may result from institutional changes, such as the use of metering or pricing, is included in Chapter V. As mentioned previously, the changes in water demand occasioned by changes in population projections are presented in Chapter IV. METHODOLOGY As discussed previously, municipal demands consist of several elements, including domestic (household), commercial (restaurants, hotels, and service stations), institutional (schools and hospitals), public (street cleaning and fire protection), and industrial. Generally speaking, a given service population with a particular character can be assumed to support commercial, institutional, domestic, and public needs that are indigenous to the area. Thus, the non-industrial components of municipal water use can be expected to grow proportionately with population. Industrial demands, however, are more a function of the manufacturing process involved and are not necessarily directly related to a city's population growth. Thus, the industrial, and the aggregated domestic, commercial, and public demands, were projected separately for each water service area. Difficulties arose in attempts to determine the industrial component of the usage in each water service area, as data regarding industrial use are not. normally compiled as part of the management and operation of most water systems. Thus, a Bay-wide relationship between publicly supplied non- industri,ql water use and per capita income was derived in order to disaggregate the non-industrial and industrial components of public usage for each water service area. This approach is supported by the fact that as affluence increases, in areas of more highly developed economies, the demand for water for domestic purposes also tends to increase. People in the higher income levels are better able to afford such water-using appliances as washing machines, dishwashers, and air-conditioning. Increased incomes also tend to be rl accompanied by increased demands for watering of large lawns in suburban areas, and increasing numbers of private swimming pools. Areas of higher per ADnendix 5 38 capita income are also associated with a more extensive and diverse com- mercial activity, as well as increased activity in the public sector. The relationship between per capita income and per capita non-industrial water use is shown in Figure 5-4. As derived in the Bureau of Domestic Commerce survey of industrial water use, subregional values of all water publicly supplied to industry were used in conjunction with aggregated total public usage in each subregion to determine non-industrial per capita use rate for each subregion. These per capita use rates were plotted against the average per capita income in all areas of greater than 2,500 population in each subregion to obtain the curve in Figure 5-4. Using Figure 54 and the q, appropriate per capita income, an estimate of the 1970 non-industrial usage for each water service area was derived. Adjustments were made in certain cases in which results were unreasonable or in conflict with existing data. Also, the relationship in Figure 5-4 was not used for water systems that were known to supply no industrial needs. In these instances, the 1970 non-industrial use rate is merely that presented in Chapter 11, Table 5-1. 180 :6 160 0 CL '140 cc 120 06 CL 100 V C . 80- C 0 z so- z 20OU 3000 4000 5000 6000 7000 Per Capita incomem FIGURE 5-4. NON-INOUSTRJA L PER CAPITA USE RATE VERSUS INCOME, 1970 Appendix 5 39 After the 1970 non-industrial per capita use rates were defined for each water service area, projections of the per capita water uses were made using a methodology derived by the Federal Water Pollution Control Administration (now EPA) for the Ohio River basin Comprehensive Survey. A relationship between per capita use rate and annual growth in use rate, as shown in Figure 5- 5, was derived through a statistical sampling and analysis of consumption in both small and large cities. The curve was used previously in the North Atlantic Water Resources Study and it is assumed that the future growth in per capita water demand in the Bay Area will occur in a like manner. Based on this curve, the annual percent rate of increase in per capita water use will be faster in areas with lower use rates, and slower in areas with higher use rates. For example, the usage in service areas with use rates of 150 gpcd will increase more slowly than it would in areas using 40 gpcd. Also, limits in use rates are approached using this methodology, whereas other commonly used projection methodologies allow growth to unrealistically high levels. For example, a standard approach in many projection methodologies is to assume 3V S 2.0 C 0 cc -i 1.0 C C 01 40 60 so 100 120 140 160 Per Capita Use Rate (any year 1970-2020) FIGURE 5-5., RA TE OF GROWTH IN PER CAPITA USE RA TE) RA TE (15) ADpendix 5 40 a one percent per year increase in the per capita use rate. The following is a comparison of results using the graduated use rate method and the one percent per year compounded method. After 50 Years Initial Use Rate Graduated Method 1% Compounded (gpcd) 40 90 66 66 109 108 too 128 164 150 185 247 Per capita use rates, as derived for each community water system using the graduated use rate method, are presented in attachment 5-A. Following the above determination of projected per capita use rates, the next step in the analysis was to project the population in each of the water service areas. Population projections for the cities and counties of the Chesapeake Bay Area were prepared by the Bureau of Economic Analysis (BEA), U.S. Department of Commerce, from the OBERS Series C economic and demographic projections. Since the service population in many of the water service areas differed from the known census population in many of the communities (usually due to service outside the defined geographical limits of the community), it was assumed that the proportion between the two population numbers would remain constant from the base year (1970) through the year 2020. The ratio between the service and census population for each community, when applied to the projected census population, as provided by BEA, yields the estimated future service population in each community for each goal year. The projected service populations for each water service area are presented in Attachment 5-A. Given the projected per capita use rates and the expected populations of the water service areas, the future non-industrial demands on the large systems are the product of the two parameters. The Industrial water that is publicly supplied in each of the water service areas was disaggregated from the total subregional industrial demands. The projected amount of water publicly supplied to industry for each subregion was disaggregated to the various water service areas based on a shares analysis of future employment growth within each water service area. Implicit in this approach is the assumption that the water utilities will indeed continue to supply expanding industrial needs. It is acknowledged, however, that policy decisions at the local level may influence the future magnitude and distribution of industrial demands in the area. ADnendix 5 A 1 Small water systems (those serving fewer than 2,500 persons) were projected as an aggregate, by subregion, using the same per capita rate of increase curve as for larger systems (Figure 5-5). Populations were derived by relating projections of total county population to the population of small towns and cities. The historical percentage increase in the growth of small towns and cities in the Chesapeake Bay Area was found to vary according to the regression: 6.0 + 2.33Xi, where Xi represents the percent increase in county population over the previous decade. Based on previous studies and observations of average water use in the Eastern United States, an initial non- industrial water use rate of 85 gped was selected as being representative of the average use in small systems in the Bay Area. It was assumed that there was no industrial component of demand in the small systems. PROJECTED MUNICIPAL DEMANDS Based on the methodology discussed in the preceding section the municipal demands were developed. These are presented in Table 5-7, by subregion, for each Water Service Area in the Chesapeake Bay Area. The non-industrial and industrial components, and the total are shown for each goal year, and sums tabulated for each subregion. In some cases, the present demands in some service areas exceed the amount that would normally be expected based on the income or industrial activity of the community. These "unaccounted demands" are carried through as a constant for all the goal years. In such cases, the particular water service area in question is asterisked. These unaccounted for amounts may result from any number of factors, including excess leakage (as is probably the case at Crisfield), unusual military or institutional use (such as at Williamsburg), or public usage in excess of what might be expected (as is the case at Washington). Results for the aggregated water use by small systems in each subregion are detailed in Table 5-8. INDUSTRIAL WATER SUPPLY DEMANDS In the previous chapter, industrial water withdrawals were shown to be 1,615 mgd. Of this, however, only 37 percent was from fresh sources, illustrating the importance of brackish water to the industries around the Chesapeake. Other sources include groundwater, surface water, and one instance of wastewater reuse in the Baltimore area. Most of the demands were shown to be concentrated at Baltimore, Richmond, and the Hampton Roads areas. These centers of industrial activity are expected to form the focus of future growth and industrial expansion as well. jF1 Annendix 5 42 4k) TABLE 5-7 PROJECTED MUNICIPAL & INDUSTRIAL DEMANDS 1970 1980 1990 2000 2020 W. S. A. Total M I Total M I Total M I Twit M I Total SUBREGION I Aberdeen 1.2 3.3 0.7 4.0 5.6 0.8 6.4 8.2 0.9 9.1 15.4 1.2 16.6 Annapolis 4.3 5.4 0.8 6.2 6.0 0.7 6.7 6.6 0.5 7.1 7.1 0.4 7.5 Baltimore 245.0 218.8 66.6 285.4 262.6 50.3 312.9 309.9 46.7 356.6 420.6 50.0 470,6 Bel Air 1.0 1.7 0 1.7 2.4 0 2.4 3.0 0 3.0 4.2 0 4.2 Crofton 0.8 1.2 0 1.2 1.6 0 1.6 1.7 0 1.7 1.8 0 1.8 Edgewood (Perryman) 1.2 1.6 0.5 2.1 2.7 0.5 3.2 4.0 0.6 7.6 1.0 8.6 Havre de Grace 1.55 1.2 0.4 1.6 1.5 0.3 1.8 1.6 0.2 1.8 1.8 0.2 2.0 Joppatowne 0.6 0.9 0 0.9 0.9 0 0.9 1.0 0 1.0 1.2 0 1.2 Maryland City 0.6 1.4 0.1 1.5 2.0 0.1 2.1 2.6 0.1 2.7 4.0 0.1 4.1 King's Heights (Odenton) 0.5 0.8 0 0.8 1.1 to 1.1 1.3 0 1.3 1.8 0 1.8 Severna Park (Severndale) 1.8 3.1 0 3.1 4.4 0 4.4 5.9 0 5.9 9.2 0 9.2 SykegvWe - Freedom 0.6 0.9 0 0.9 1.4 0 1.4 1.6 0 1.6 2.3 0 2.3 Westminster 1.1 1.5 0.1 1.6 2.0 0.1 2.1 2.3 0.1 2.4 2.9 0.1 3.0 Subtotal 260.3 242. 69. 311. 294. 53. 347. 350. 49. 399. 480. 53. 533. SUBREGION 2 Cambridge* 3.9 1.5 0.9 4.2 1.8 0.7 4.3 2.2 0.9 4.9 3.0 1.2 6.0 Centreville 0.3 0.4 0 0.4 0.5 0 0.6 0 0.6 0.9 0 0.9 Chestertown 0.5 0.6 0.1 0.7 0.7 0.1 0.8 0.8 0.1 0.9 1.2 0.1 1.3 Crisfield* 1.4 0.3 0.6 1.5 0.4 0.5 1.5 0.5 0.5 1.6 0.6 0.6 1.8 Delmar 0.3 0.4 0 0.4 0.4 0 0.4 0.5 0 0.5 0.6 0 0.6 Denton* 0.4 0.3 0 0.5 0.3 0 0.5 0.4 0 0.6 0.5 0 0.7 Easton 1.0 1.5 0 1.5 1.9 0 119 2.4 0 2.4 3.5 0 3.5 Elkton* 1.0 1.1 0 1.2 1.3 0 1.4 1.4 0 1.5 1.8 0 1.9 Pocomoke City 0.3 0.4 0 0.4 0.6 0 0.6 0.7 0 0.7 1.0 0 1.0 Princess Anne 0.2 0.3 0 0.3 0.3 0 0.3 0.4 0 0.4 0.6 0 0.6 Salisbury* 4.0 1.9 1.3 4.5 2.2 1.2 4.7 2.7 1.3 5.3 3.6 1.5 6.4 Snow HiR* 0.5 0.4 0.1 0.7 0.5 0.1 0.8 0.6 0.1 0.9 0.8 0.2 1.2 Subtotal* 13.8 9.1 3.0 16.3 10.9 2.6 17.7 13.2 2.9 20.3 18.1 3.6 25.9 SUBREGION 3 No Large Systems SUBREGION 4 > Seaford 0.8 0.8 0.2 1.0 1.1 0.1 1.2 1.3 0.1 1.4 1.8 0.1 1.9 (D Note: See Attachment A for tabulation of populations and use rates. 0 x *Totals include unaccounted for balances TABLE 5-7 (Cont'd) > PROJECTED MUNICIPAL & INDUSTRIAL DEMANDS Id 2000 2020 0 1970 1980 1990 W. S. A. Total M I Total M I Total M I Total M I Total SUBREGION 5 Washington Suburban Sanitary Commission 124.0 167.0 2.1 169.1 220.4 2.2 222.6 293.3 2.9 296.2 448A 4.9 453.3 Washington Aqueduct* 200.0 160.8 1.3 219.7 182.5 1.1 241.2 204.9 1.3 263.8 267.9 1.8 327.3 Alexandria 13.0 16.0 0.2 16.2 19.8 . 0.2 20.0 22.1 0.2 22.3 27.3 0.3 27.6 Fairfax County Water Authority 36.5 68.4 1.0 69.4 103.0 2.4 105.4 146.8 3.5 150.3 275.3 6.7 282.0 Goose Creek - Fairfax City 7.1 15.9 0 15.9 23.3 0.1 23.4 31.5 0.1 31.6 58.2 0.1 58.3 Manassas 1.3 2.1 0 2.1 3.0 0 3.0 3.7 0 3.7 4.8 0 4.8 Manassas Park 0.4 0.8 0 0.8 1.4 0 1.4 2.0 0 2.0 3.9 0 3.9 Subtotal* 382. 431. 5. 494. 553. 6. 617. 694. 8. 760. 1,086. 14. 1,158. SUBREGION 6 Leonardtown 0.4 0.3 0 0.3 0.3 0 0.3 0.3 0 0.3 0.4 0.1 0.5 Lexington Park 1.0 1.5 0.1 1.6 2.6 0.1 2.7 4.0 0.1 4.1 8.5 0.2 8.7 Waldorf 0.8 1.4 0.1 1.5 2.5 0.2 2.7 3.9 0.3 4.2 8.4 0.6 9.0 Subtotal 2.2 3.2 0.2 3.4 5.4 0.3 5.7 8.2 0.4 8.6 17.3 0.9 18.2 SUBREGION 7 Fredricksburg 2.6 18 0.3 3.1 3.4 0.2 3.6 4.0 0.2 4.2 5.5 0.3 5.8 SUBREGION 8 Ashland 0.35 0.5 0 0.5 0.9 0 0.9 1.0 0 1.0 1.3 0 1.3 Colonial Heights - Petersburg 7.1 8.6 0.4 9.0 11.3 0.3 11.6 14.8 0.4 15.2 24.3 0.5 24.8 Hopewell 25.8 5@8 19.8 25.6 7.7 19.5 26.2 10.6 21.1 31.7 18.1 32.0 50.1 Mechanicsville 0.28 1.2 0 1.2 2.3 0 2.3 3.8 0 3.8 8.9 0 8.9 Richmond 41.1 48.6 0.7 49.3 58.5 0.7 59.2 72.2 0.6 72.8 103.3 0.8 104J Subtotal 74.6 65. 21. 86. 81. 20. 100. 102. 22. 124. 156. 33. 189. SUBREGION 9 West Point 0.26 0.3 0 0.3 0.4 0 0.4 0.4 0 0.4 0.6 0 0.6 SUBREGION 10 Newport News System 27.3 34.1 2.7 36.8 40.1 2.2 42.3 47.9 2.1 50.0 64.9 2.6 67.5 *Totals include unaccounted for balances. V. IT TABLE 5-7 (Cont'd) PROJECTED MUNICIPAL & INDUSTRIAL DEMANDS 1970 1980 1990 2000 2020 W. S. A. Total M I Tot M I Total M I Total M I Total SUBREGION 11 Norfolk System 515 60.6 1.1 61.7 70.0 0.8 70.8 82.1 0.9 83.0 107.8 1.1 108.9 Portsmouth System' 13.7 15.5 2.5 18.0 19.5 2.1 21.6 23.5 2.1 25.6 32.3 2.9 35.2 Subtotal 66.2 76.1 3.6 79.7 89.5 2.9 92.4 106. 3.0 109. 140. 4.0 144. SUBREGION 12 Williamsburg* 2.5 3.5 0 4.2 4.0 0 4.7 4.8 0 5.5 6.5 0 7.2 Smithfield 0.3 0.3 0.1 0.4 0.4 0.2 0.6 0.5 0.3 0.8 0.6 0.6 1.2 Suffolk Area 1.8 2.1 0.7 2.8 2.5 0.9 3.4 3.0 1.4 4.4 4.0 2.9 6.9 Subtotal* 4.6 5.9 0.8 7.4 6.9 1.1 8.7 8.3 1.7 10.7 11.1 3.5 15.3 Chesapeake Bay Area Total 835. 870. 106. 1,039. 1,086. 88. 1,237. 1,335. 89. 1,487. 1,981. 115. 2,159. 'Not including Suffolk. *Totals include unaccounted for balances. Ln TABLE 5-8 PROJECTED WATER USE By SMALL SYSTEMS, CHESAPEAKE BAY AREA, 1970-2020 Population 1970 Water Use 1980 Water 1990 Water 2000 Water 2010 Water 2020 Water Subregion (L000's) (mgd) POP. Use POP. Use POP- Use POP, Use POP- Use 1. Baltimore, SMSA 95.0 8.1 162.7 15.1 205.1 20. 7 233.4 25.4 232.2 27.1 224.3 28.0 2. Non-SMSA, ME 56.3 4.8 80.4 7.5 106.5 10.8 136@O 14.8 165.6 19.4 195.0 24.3 3. Non-SMSA, VA 9.4 0.80 10.8 1.0 12.4 1.3 13.7 1.5 15.4 118 17.4 2.2 4. Susse. Co., DF 12.8 1.1 19.4 1.8 27.3 2.8 34.0 3.7 42.3 4.9 51.9 6.5 5. Washington, D. C., SMSA 95.4 8.1 38.0 3.5 57.8 518 75.0 8.2 103.2 12.1 140.0 17.4 6. Non-SMSA, MD 23.5 2.0 35.8 3.3 56.4 5.9 $6.2 9.6 110,2 12.9 124.0 15.5 7. Non-SMSA, VA 13.4 1.1 21.4 2.6 31.5 3.2 45.1 4.9 64.8 7.6 88.0 11.0 8. Richmond, SMSA 61.4 5.2 99.0 9.2 136.6 13.8 175.9 19,2 226.0 26.4 268.6 33.5 9. Non-SMSA, VA 29.3 2.5 39.4 3.7 45.4 4.6 55.7 6.1 67.6 7.9 79.0 9.8 10, Newport News- Hampton S14SA 5.37 0.46 7.89 0.73 12.0 1.1 13.7 115 11.1 1,3 8.04 1.0 11. Norfolk-Ports- mouth SMSA 8.16 0.69 11.0 1.0 14.8 1.5 19.6 2.1 25.4 3.0 26.4 3.3 12. Non-SMSA, VA 26.1 2.2 35.3 3.3 44.3 4.5 59.9 6.4 78.3 9.2 91.0 11.3 TOTAL 436.1 37.0 561.1 52.1 751.1 76.0 949.2 103.4 1,142.1 133.6 1,313.6 163.8 -SI A major consideration in the projection of industrial water supply demands is the fact that federal water quality goals may impact heavily on industrial water use habits. The 1972 Amendments to the Federal Water Pollution Control Act (PL 92-500), require application of "best practicable" treatment technology by 1978, and of "best available" technology by 1983 (without further defining the quoted terms). In addition, the act advocates that a goal of "zero discharge" of pollutants be sought. As a result, improved recycling technology will probably occur as industries begin to comply with directives, and strive for higher levels of waste treatment. Significant reductions in intake demand are associated with increased recirculation within an industry. The more that water is recirculated, the less water is needed to replace that discharged. Future water use patterns will thus depend on the degree to which recirculation technology is utilized by the industries in the Chesapeake Bay Area. In consideration of this, three alternative sets of projections were developed to reflect various degrees of recirculation. The projections vary only in the projected rates of recycling. Such measures of economic growth as production, employment, and earnings are thus the same in all three cases. Following a discussion of the derivation of the alternative projections, the assumptions and methodology used to accomplish the third and final set, which was selected for use in the balance of the report, is presented. The Sensitivity Analysis, to be included as a later chapter in this report, presents, and makes comparisons between, the industrial water supply demands that result from allthree of the alternatives. DISCUSSION The results of the survey of industrial establishments and water use, as presented in Chapter 11, were developed by the Bureau of Domestic Commerce, U.S. Department of Commerce (BDC), under contract with the Baltimore District, U.S. Army Corps of Engineers. The balance of the work performed under this contract involved the projection of future industrial demands. The projections were derived by assuming (in part) that each industry group will achieve, as an average, the maximum theoretically, possible recycling rate (R), by 2020, where R = G/I as defined previously in Chapter 11. Very marked reductions in industrial withdrawal demands and discharges result from this methodology which is termed Projection Set 1. The gross water use and consumption figures generated in this initial analysis also formed the basis for derivation of the intake demands for all three projection sets. The values for "recycling rate", obtained through the BDC survey of individual plants, reflect all combinations of in-plant process technology and/or water recycling in the strict sense. The terms "technology" and "recycling" are thus used interchangeably in this report to refer to advances in efficiency in Appendix 5 47 industrial water use, whether it be through improved production processes (which are important factors in certain types of industry) or recycling (which usually occurs in cooling and/or by-product recovery operations). For comparison purposes, Projection Set 2 was developed which assumed industry would maintain present rates of recycling technology throughout the goal years. Water withdrawal requirements in this case increase proportionally with the projected gross water demand. A comparison of the plots of the recycling rate associated with Projection Set I (assuming implementation of advanced technology) and Set 2 (constant technology) is shown in Figure 5-6. Upon examination, the two projection sets were felt to represent what might best be termed an "envelope" of values that C reflect the impact of recycling in future industrial water use. Ii is felt, for example, that future industrial recycling practice will most probably exceed the conditions of constant recirculation (Set 2). In addition to the influence of the national water quality goals, other factors are known to increase industrial water reuse and subsequently reduce withdrawal requirements. For example, recirculation of supplies is utilized by some industries to recover materials in the process water. Other industries increase their recycling ratios to, very simply, conserve water. Regarding Projection Set 1, it is likely that a future review and analysis of the National water quality goals may eventually result in a redefinition of certain water quality standards. This would in turn permit industry to fall back from the "maximum theoretically possible" recycling rates, as assumed in Projection Set 1. It has been estimated by the National Water Commission, in their report to the President in 1973, that attainment -of the 1983 water quality goals would cost industry $108 billion (in 1972 dollarS51). It is questionable whether the expenditure of these funds by industry (and ultimately the consumer and taxpayer) will provide equal benefits in terms of environmental quality. It has been estimated by a major chemical manufacturer, for example, that by 1977, 93 percent of their potential BOD will be removed. To remove the next 5 percent will require an additional capital investment of $78 niillion-a 50 percent investment increase to achieve a mere 5 percent improvement50. In view of the above considerations, a third set of industrial demands was derived that reflects a moderate future growth in water use technology. Projection Set 3 was made based on a straight-line continuation of the 1975 to 1980 trend in recycling as projected by BDC for each major industrial sector. The resultant plot of Projection Set 3, shown in Figure 5-7 as "moderate technology," illustrates the trend as compared with Projection Sets I and 2, and with historical recycling rates at the national and regional levels. The historical data were compiled from the Special Report Series volume: "Water Use in Manufacturing," from the U.S. Department of Commerce's Census of Manufacturers. AD.pendix 5 48 INDUSTRIAL WATER USE TECHNOLOGY, PROJECTION SETS 1 AND 2 25,, ---- - ------ d loco 20; 7-@ p 10 Constant 1I Projection Set 2: Technology B E3 L7V 0 1970 1980 1990 2000 2010 2020 YEAR FIGURE 5-6 Arlpen(lix 5 1,.(,) TRENDS IN INDUSTRIAL WATER USE TECHNOLOGY, PROJECTION SETS 1,2, AND 3 25 7 Cl 'Ter. nee P'dV8 2 0 - - - - - - ------ 15 C, -J w LU CL cc 4A 4\0 _J 5 obtlo, no Projection Constant Set 2: Technology -44 Regional 1,2:,, 1950 1960 1970 1980 1990 2000 2010 2020 YEAR NOTES: 1. Points Derived From Census Of Manufacturers, U.S. Bureau Of Census. V@ 2. Regional Date includes Water Use In The Delaware And Hudson Rivers As Well As Chesapeake Bay. FIGURE 5-7 ADDendix 5 50 This discussion was presented in order to trace the development of the industrial water demands used in this report. Specific assumptions and details of the methodology are included in the following two sections. ASSUMPTIONS Certain basic assumptions were used in the projection of industrial water use for the Chesapeake Bay Area. Uncertainties as to future trends in such things as employment, the Gross National Product, and National water quality goals \rnake certain assumptions necessary. Basic assumptions are also needed @oncerning the future industrial mix, geographical site locations, and possible improvements in water use technology. As stated previously, gross water demands remain the same in each of the three projection sets. In the methodology used by the Bureau of Domestic Commerce to derive these gross demands, the following assumptions were made: a. Gross demands for each industrial sector grow in relation to Gross Product Originating (GPO), as derived from OBERS projections of earnings. b. Projections of consumptive use are based on a continuation of the 1970 observed relationship of consumption and gross demand. Projection of water intakes for Projection Set I involves a series of assumptions regarding future recycling: a. "Best available technology" is reflected by the average of the 20 highest recycling ratios reported by any particular 4-digit SIC industry in the 1970 BDC National survey, including the more efficient production technologies. b. The weighted average of the 4-digit "20-best" reflect the recycling ratios for the entire industry group (2 digit), by 1985. c. For the year 2000, each industry group will achieve their maximum theoretical recycling rate, towards the National goal of zero discharge of pollutants (the theoretically possible recycling rate is calculated from current gross water uses and projected minimum intakes). Appendix 5 51 Projection of water intakes in Projection Set 2 assumed a continuation of recycling rates at the 1970 level for each major water-using industrial sector. The water intakes derived in Projection Set 3 assume a straight line continuation of the 1975 to 1980 trend projected in Projection Set 1. METHODOLOGY The most important parameter in projecting industrial water needs is the gross water demand, since it is from this that projections of withdrawals and consumptive losses are determined, and upon which the accuracy of all other use components depend. The gross water demand may be expected to vary directly with manufacturing output-the more products, the greater the demand for water. For the manufacturing sector as a whole, this expectation has been confirmed in the last four censuses of manufactures. In those censuses, the gross water demand per unit output (measured in constant dollars value added in manufacturing) has remained relatively constant, varying by less than 2 percent. Gross water demands were projected by developing coefficients for each major water-using industry group and the residual industries as a single group by relating the reported 1970 gross water demands to the production proxy (GPO). The latter was derived from the constant dollar earnings and conversion factors provided for the Chesapeake Bay Study in the economic forecasts of OBERS (Office of Business Economics and the Economic Research Service). The gross water demand can be satisfied by any combination of withdrawal and recycling of water, with the options ranging from once-through use of water, in which case withdrawal equals gross water demand, to a completely closed recycling system in which, after the initial input of water, the withdrawal requirement reduces to zero. It is obvious, then, that if the gross water demand is to be met, the extent to which recycling is practiced determines the amount of water that will be withdrawn. Except for the most simple of manufacturing operations, however, a closed system is impractical, and, manufacturing operations being generally complex combinations of operations, water is consumed or lost from the system by evaporation, leaks, incorporaton into products, etc. In any system in which the gross demand is met in whole or part by recycling, those consumptive losses must be made up by equivalent additions of new intake water. Consumptive losses, then, impose a minimum requirement for withdrawal, and impose a theoretical limit on the ratio of recycled water to gross demand. ADDendix 5 52 Consumption of water as an element-in industrial water use is derived by subtracting reported discharges from reported withdrawals. There are inherent errors in this derivation, however, which result from the lesser reliability of the discharge quantities reported (usually estimated) as compared to the reported withdrawals which are usually obtained from meter readings and pumping records. As a result of this, the relationship of consumptive use to gross water demand, or to value added, appears in the Census of Manufacturers to be inconsistent. In this study, because consumptive losses are a critical parameter in the forecasts for future planning, these inconsistencies have been ignored and projections of consumptive use have been based on a continuation of the observed relationship of consumption to gross demand as revealed in the BDC 1970 survey, converging that relationship to the National averages for any particular industry group for which the regional ratios appeared to be unreasonable. The projected withdrawal requirements (intake) were derived differently for the three alternative projection sets. The methodologies used for derivation of each set are discussed in the following subsections. Projection Set 1 While it is acknowledged that recycling practices in manufacturing are influenced by many factors, the projected withdrawal requirements for Projection Set I were calculated by assuming that improved recycling practices will occur in the future as higher levels of waste treatment are instituted by the manufacturers as required by the 1972 Amendments to the Federal Water Pollution Control Act (PL 92-500). To couple the timetable of improved waste-treatment to projections of industrial water withdrawals, the following assumptions and calculations were made. It is, assumed that the current "best-available" technology is reflected in the average of the 20 highest recycling ratios reported by all individual establishments in any 4-digit SIC industry in the 1970 BDC nationwide survey. The averages are generally referred to as the "20-best" file. Weighing these 20- best averages for the 4-digit SIC industries by the gross water used in each, an equivalent recycling ratio for each 2-digit SIC group was produced. This ratio was then assumed to be achieved by the entire industry group, regionally and nationally, by 1985. For the year 2000, it was assumed that each industry group will, in the process of achieving the national goal of zero discharge of pollutants, achieve the maximum theoretically possible recycling rate. The theoretical maximum recycling rate is calculated from current gross water uses and projected minimum intakes. The latter is the sum of current consumption and additional ADDendix 5 53 consumptive losses that could result from the requirements to abate thermal pollution from all non-contact cooling water used in manufacturing. The losses were estimated on the basis of probable evaporative losses by 2000 from the use of cooling towers and ponds. From the calculated gross water demands and recycling rates from 1985 and 2000, withdrawal requirements were derived and the degree to which recycled water provided for the gross demand was determined as percent recycled water. For the interim years 1980 and 1990, the percentages of recycled water were computed by compound interest rate formulae based on the differences between values developed for 1970, 1985 and 2000. Beyond the year 2000, recycling rates are kept constant at the theoretically maximum achievable year 2000 rates. The results of this analysis are presented in their entirety in the Sensitivity Analysis section of this report. Projection Set 2 Industrial water withdrawals were derived in Projection Set 2 by assuming that the recycling rates identified in the BDC survey of industrial water use would remain constant within each industrial sector through the year 2020. Results of this set of calculations are presented in the Sensitivity Analysis section of this report. Proje ction Set 3 As discussed previously, Projection Set 3 was developed as a compromise between Projection Sets I and 2, being reflective of a more moderate growth in recycling. Future recycling rates for each major industrial sector were determined through a straight-line extension of the 1975 to 1980 trend as projected by the Bureau of Domestic Commerce. Use of Projection Set 3 acknowledges that, while recycling rates will indeed continue to improve, it is more likely that a lesser degree of implementation of technology in industrial water reuse will occur than that assumed in Projection Set 1. It is in response to this possibility, and towards the desire for a more conservative planning guide, that Projection Set 3 was selected for use in the balance of the analysis. ADnendix 5 51, PROJECTED INDUSTRIAL DEMANDS Projections of industrial water demands, as derived through the methodology and assumptions implicit in Projection Set 3, are presented in this section. Gross demands, intake, consumption, and discharge are presented for each major water-using industrial sector, and for the manufacturing industries as a whole, in Table 5-9. Industrial water use is also presented on a subregion by subregion basis in Table 5-10. Water intake requirements for each subregion and each goal year are disaggregated as to source, i.e., whether the supply is expected to derive from fresh or brackish sources, and whether the freshwater will come from ground or surface courses. Table 5-10 also shows whether demands are expected to be met by the industries themselves or through public systems. Each of these components has been computed by assuming that each will remain as a constant proportion of total intake through the entire study period. AVAILABLE WATER SUPPLIES In order to identify future freshwater supply shortages in the major communities of the Chesapeake Bay Area, demands for water supply in each of the defined Water Service Areas are compared with the capacities of the existing systems. Capacities are defined in two ways: as the "safe yield" of presently developed sources, and the capacity of existing pumping systems and treatment plants. The capacities of these systems and sources are presented in this section. The influence of post-treatment storage facilities, as to their effect on the amount of water available during droughts, are neglected for the purposes of this report. This study has also undertaken an analysis of the overall amount of water that could be developed from all possible sources and made available for use in the area. In this analysis, water supply demands in each subregion for all uses (except cooling in electric power generation) are aggregated and compared with the total of all presently developed freshwater resources and estimates of the resources that could potentially be developed. The total resource includes existing strearnflows and diversions, estimates of maximum sustainable groundwater yields, and safe yields of existing reservoirs. HYDROLOGIC CONSIDERATIONS The hydrologic cycle in the Bay Area can be viewed as a closed system. In general, conservation occurs in that the amount of water falling as precipitation balances, in the long run, the amount leaving the region through evapotranspiration, stream runoff, or by the discharge of groundwater out of the area. A particular unit of water may, however, undergo many uses and AnDendix 5 55 TABLE 5-9 WATER USE IN MANUFACTURING, BY SECTOR, CHESAPEAKE BAY AREA, mgd PROJECTION SET 3 Gross Water Recycling Demand Intake Consumption Discharge Rate ALL MANUFACTURING 1970 23607.9 1,615.5 74.2 1,541.3 1.61 1975 [email protected] 1,823.9 112.5 1,711.4 1.93 1980 45408.2 1,581.4 157.5 1,423.9 2.79 1990 6,001.6 1,344.1 246.4 1,097.7 4.47 2000 8,591.5 1,397.8 341.3 1,056.5 6.15 2020 17,290.2 1,822.9 652.4 1,170.5 9.48 FOOD & KINDRED PRODUCTS (SIC 20) 1970 79.7 74.3 5.6 68.7 1.07 1975 95.4 81.3 6.1 75.2 1.17 1980 111.1 75.3 6.4 68.9 1.48 1990 146.0 70.2 6.3 63.9 2.08 2000 196.4 73.2 8.4 64.8 2.68 2020 343.9 88.4 14.8 73.6 3.89 PAPER & ALLIED PRODUCTS (SIC 26) 1970 644.8 72.8 7.6 65.2 8.86 1975 848.2 88.1 17.8 70.3 9.63 1980 1,051.6 100.9 25.2 75.7 10.42 1990 1,546.1 128.7 49.5 79.2 12.01 2000 2,334.9 171.7 -174.6 97.1 13.60 2020 5,145.5 306.7 164.4 142.3 16.78 CHEMICALS (SIC 28) 1970 402.5 328.1 14.5 313.6 1.23 1975 560.1 382.6 19.6 363.0 1.46 1980 719.3 342.3 24.5 317.8 2.10 1990 1,131.5 335.1 33.9 301.2 3.38 2000 1,804.5 388.0 54.2 333.8 4.65 2020 4,319.3 599.9 129.7 470.2 7.20 ApPendix 5 56 TABLE 5-9 (Cont'd) WATER USE IN MANUFACTURING, BY SECTOR, CHESAPEAKE BAY AREA, mgd Gross Water Recycling Demand Intake Consumption Discharge Rate PETROLEUM (SIC 29) 1970 81.6 76.3 0.7 75.6 1.07 1975 99.8 79.4 0.9 78.5 1.19 1980 105.3 63.3 1.2 62.1 J.66 1990 136.9 52.6 1.9 50.7 2.60 2000 178.9 50.5 2.5 48.0 3.54 2020 294.8 54.4 4.1 50.3 5.42 PRIMARY METALS (SIC 33) 1970 1,094.6 882.3 35.1 847.2 1.24 1975 1,423.4 965.5 54.1 911.4 1.47 1980 1,752.1 815.6 78.8 736.8 2.15 2,203.2 630.2 130.0 500.2 3.50 2000 2,823.6 582.9 166.6 416.3 4.84 2020 4,536.8 601.7 267.7 334.0 7.54 OTHER MANUFACTURING 1970 304.7 181.7 10.7 171.0 1.68 1975 490.6 227.0 14.0 213.0 2.16 1980 668.8 184.0 21.4 162.6 3.63 1990 837.9 127.3 24.8 102.5 6.58 2000 1,253.2 131.5 35.0 96.5 9.53 2020 2,649.9 171.8 71.7 100.1 15.42 Appendix 5 57 TABLE 5-10 PROJECTED WATER USE IN MANUFACTURING, MGD PROJECTION SET 3 SUBREGION 1 1970 1980 1990 2000 2020 GROSS USE 1226.1 2179.2 2751.8 3608.4 5997.5 INTAKE 990.7 1034.2 830.2 793.3 856.4 -Public Supply 70.0 69.2 52.6 49.2 52.7 -Brackish 781.2 825.7 638.1 604.5 661.7 -Self-Supplied, fresh 17.3 17.1 13.0 12.0 13.0 Ground 14.4 14.2 10.8 10.0 10.9 Surface 2.9 2.9 2.2 2.0 2.1 -Wastewater 122.2 122.2 126.5 127.6 129.0 CONSUMPTION 43.7 114.2 156.0 201.5 336.4 DISCHARGE 947.0 920.0 674.2 591.8 520.0 SUBREGION 2 - 1970 1980 1990 2000 2020 GROSS USE 35.5 44.5 52.2 71.6 124.1 INTAKE 34.8 34.6 30.8 33.8 41.8 -Public Supply 3.0 3.0 2.6 2.9 3.6 -Brackish 0.7 0.7 0.6 0.6 0.8 -Self-Supplied, fresh 31.1 30.9 27.6 30.3 37.4 Ground 30.0 29.8 26.7 29.1 36.0 Surface 1.1 1.1 0.9 1.2 1.4 CONSUMPTION 0.9 1.4 1.9 2.5 4.0 DISCHARGE 33.9 33.2 28.9 31.3 37.8 Appendix 5 58 TABLE 5-10 (cont'd) PROJECTED WATER USE IN MANUFACTURING, MGD PROJECTION SET 3 SUBREGION 3 1970 1980 1990 2000 2020 GROSS USE 2.6 3.3 4.1 5.4 9.2 INTAKE 2.3 2.0 1.7 1.7 1.9 -Public Supply 0.3 0.3 0.2 0.2 0.2 -Brackish 0.1 0.1 0.1 0.1 0.1 -Self-Supplied, fresh 1.9 1.6 1.4 1.4 1.6 Ground 1.9 1.6 1.4 1.4 1.6 Surface 0.0 0.0 0.0 0.0 0.0 CONSUMPTION 0.2 0.2 0.2 0.2 0.4 DISCHARGE 2.1 1.8 1.5 1.5 1.5 SU73REGION 4' 1970 1980 1990 2000 2020 GROSS USE 82.7 86.4 53.12 81.1 175.0 INTAKE 65.6 43.5 18.0 20.6 29.5 -Public Supply 2.7 1.8 0.7 0.8 1.2 -Brackish 0.0 0.0 0.0 0.0 0.0 -Self-Supplied, fresh 62.9 41.7 17.3 19.8 28.3 Ground 14.9 9.9 4.1 4.7 6.7 Surface 48.0 31.8 13.2 15.1 21.6 CONSUMPTION 1.9 2.8 2.3 3.4 7.5 DISCHARGE 63.7 40.7 15.7 17.2 22.0 lIncludes Kent County, Delaware. 2Water use per dollar Gross Product Originating ($GPO) in predominant food industries was deemed high by BDC. Therefore, use rates were trended to equal Baltimore regional averages by 1990, increasing thereafter. ADY?end.ix 5 59 TABLE 5-10 (cont'd) PROJECTED WATER USE IN MANUFACTURING, MGD PROJECTION SET 3 SUBREGION 5 1970 1980 1990 2000 2020 GROSS USE 5.4 8.0 12.0 18.6 41.8 INTAKE 4.7 6.6 8.5 11.3 19.7 -Public Supply 3.3 4.6 6.0 8.0 13.8 -Brackish 0.0 0.0 0.0 0.0 0.0 -Self-Supplied, fresh 1.4 2.0 2.5 3.3 5.9 Ground 0.1 0.2 0.1 0.2 0.4 Surface 1.3 1.8 2.4 3.1 5.5 CONSUMPTION 0.2 0.3 0.5 0.6 1.2 DISCHARGE 4.5 6.3 8.0 10.7 18.5 SUBREGION 6 1970 1980 1990 2000 2020 GROSS USE 0.8 1.33 2.13 3.47 7.47 INTAKE 0.8 1.33 2.13 3.47 7.47 -Public Supply 0.1 0.17 0.27 0.43 0.93 -Brackish 0.0 0.00 0.00 0.00 0.00 -Self-Supplied, fresh 0.7 1.16 1.86 3.04 6.54 Ground 0.7 1.16 1.86 3.04 6.54 Surface 0.0 0.00 0.00 0.00 0.00 CONSUMPTION 0.1 0.10 0.10 n.10 0.24 DISCHARGE 0.7 1.23 2.03 3.37 7.23 AVDendix 5 60 TABLE 5-10 (cont'd) PROJECTED WATER USE IN MANUFACTURING, XGD PROJECTION SET 3 SUBREGION 7 1970 1980 1990 .2000 2020 GROSS USE 32.9 57.9 89.3 141.1 331.4 INTAKE 27.4 28.4 28.0 32.3 49.4 -Public Supply 0.2 0.3 0.2 0.2 0.3 -Brackish 0.0 0.0 0.0 0.0 0.0 -Self-Supplied, fresh 27.2 28.1 27.8 32.1 49.3. Ground 0.1 0.1 0.1 0.1 0.2 Surface 27.1 28.0 27.7 32.0 48.9 CONSUMPTION 1.8 2.4 2.7 4.2 9.9 DISCHARGE 25.6 26.0 25.3 28.1 39.5 SUBREGION 8 1970 1980 1990 2000 2020 GROSS USE 400.5 746.2 1168.9 1862.0 4458.7 INTAKE 286.8 268.9 250.9 283.4 429.9 -Public Supply 22.3 20.9 19.5 22.0 33.4 -Brackish 0.0 0.0 0.0 0.0 0.0 -Self-Suppliedo fresh 264.5 248.0 231.4 261.4 396.5 Ground 0.3 0.3 0.3 0.3 0.4 Surface 264.2 247.7 231.1 261.1 396.1 CONSUMPTION 14.0 24.7 35.3 56.3 134.5 DISCHARGE 272.8 244.2 215.6 227.1 295.4 Appendix 5 61 TABLE 5-10 (cont'd) PROJECTED WATER USE IN MANUFACTURING, MGD PROJECTION SET 3 SUBREGION 9 1970 1980 1990 2000 2020 GROSS USE 52.4 80.2 115.4 171.0 366.2 INTAKE 26.5 21.6 19.6 21.0 29.0 -Public Supply 0.2 0.2 0.1 0.2 0.2 -Brackish 10.3 8.3 7.6 8.2 11.2 -Self-Supplied, fresh 16.1 13.1 11.9 12.6 17.6 Ground 16.0 13.0 11.8 12.5 17.5 Surface 0.1 0.1 0.1 0.1 0.1 CONSUMPTION 5.0 5.2 3.7 5.5 11.7 DISCHARGE 21.5 16.4 15.9 15.5 17.3 SUBREGION 10 1970 1980 1990 2000 2020 GROSS USE 114.9 184.6 255.4 358.6 720.7 INTAKE 100.2 58.8 46.9 46.0 57.9 -Public Supply 4.6 2.7 2.2 2.1 2.6 -Brackish 90.6 53.2 42.4 41.6 52.4 -Self-Supplied, fresh 5.0 2.9 2.3 2.3 2.9 Ground 5.0 2.9 2.3 2.3' 2.9 Surface 0.0 0.0 0.0 0.0 0.0 CONSUMPTION 0.7 6.1 8.4 12.0 23.7 DISCHARGE 99.5 52.7 38.5 34.0 34.2 ADnendix 5 62 TABLE 5-10 (cont'd) PROJECTED WATER USE IN MANUFACTURING, MGD PROJECTION SET 3 SUBREGION 11 1970 1980 1990 2000 2020 GROSS USE 32.3 53.5 73.3 109.1 236.7 INTAKE 25.3 16.4 13.0 13.6 18.5 -Public Supply 5.6 3.6 2.9 3.0 4.1 -Brackish 15.9 10.3 8.1 8.6 11.6 -Self-Supplied, fresh 3.8 2.5 2.0 2.0 2.8 Ground 3.8 2.5 2.0 2.0 2.8 Surface 0.0 0.0 0.0 0_.O 0.0 CONSUMPTION 1.3 1.6 2.4 3.6 7.7 DISCHARGE 24.0 14.8 10.6 10.0 10.8 SUBREGION 12 1970 1980 1990 2000 2020 GROSS USE 621.8 963.1 1424.0 2161.1 4821.4 INTAKE 50.4 65.1 94.4 137.3 281.4 -Public Supply 0.6 0.8 1.1 1.7 3.5 -Brackish 0.0 0.0 0.0 0.0 0.0 -Self-Supplied, fresh 49.7 64.3 93.3 135.6 277.9 Ground 44.9 58.1 84.3 122.5 251.0 Surface 4.8 6.2 9.0 13.1 26.9 CONSUMPTION 4.8 31.8 47.0 71.3 159.2 DISCHARGE 45.6 33.3 47.4 66.0 122.2 APnendix 5 63 exist in several forms within the cycle. Problems thus arise in an attempt to quantify the supply of water available at a particular time and place, since it varies constantly in quantity and state. It can occur as moisture in the atmosphere, groundwater, reservoir storage, and surface-flowing streams. Water in free-flowing streams is subject to periods of low rainfall during which strearnflows may dramatically decline. The variability of flow in a stream is also a function of topography, the characteristics of the adjacent groundwater aquifers, the type and extent of vegetative ground cover in the basin, and land use. Maintenance of a strearnflow record at a particular stream gaging station, over a period of years, enables construction of a "frequency-duration" curve. This curve can be used to determine the average flow of the stream to be expected for a particular duration (typically 1, 7, or 30 days), and particular recurrence interval (usually years). While the amount of rainfall can have-a critical influence on short-term water availability, other factors influence long-term water availability. Urbanization, for example, can directly and indirectly affect the quality and quantity of available supplies. The replacement of forests and other natural vegetative cover with the impervious surfaces of the city, reduces water penetration to the natural groundwater reservoirs, thus reducing groundwater storage. Groundwater storage, which provides flow to the streams during dry periods, becomes reduced and flooding becomes serious due to the rapid runoff during periods of heavy rainfall. The high concentration of population in urbanized areas also affects the water supply availability downstream due to the massive discharges of municipal and industrial wastes. Thus, the very growth that generates the water supply demands may, at the same time, deplete or degrade the existing available resource. Uncertainty concerning future trends in these factors complicates an assessment of water availability. Areas utilizing groundwater sources, on the other hand, may have additional problems. In coastal or near-shore locations, excessive pumping may cause salt-water intrusion. Fresh groundwater reservoirs normally exert a head on the adjacent salt-water body since they extend above sea level and discharge under the force of gravity to the sea. Under heavy pumping, the water table will drop, and, if not replenished sufficiently by recharge, salt water may pollute the wells. Wells might become useless for years under these conditions. Care must also be taken that septic tank seepage, landfill drainage, or other pollutants are not allowed to penetrate to groundwater supplies. In certain areas of the country subsidence has occurred due to a drawdown of the water table. The removal of water from the pore spaces in the aquifer allows compaction of the soil and a lowering of the overlying land surface. The decrease in porosity of the aquifer causes a reduction in the potential amount Appendix 5 64 of water recoverable. Aside from this, direct curtailment of pumping may be required due to social and economic impacts resulting from the subsidence. Although many factors influence a determination of water supply availability, estimates can, and must be made of the available resource. Thorough hydrologic investigation of an area's resources is necessary in order that potential regional shortages can be forecast. Also planning for urban and community development, at the local level, must, of necessity, include provisions for water supply to insure the health and general well-being of both its citizens and business communities. The assumptions employed in assessing the Bay Area's available water supply are discussed in the following section. ASSUMPTIONS AND CRITERIA The following assumptions and accompanying criteria were necessary to assess the available water resource: a. Well yields for each particular system were assumed to be the 12-hour continious pumping yield as provided by the various State Departments of Health, except as noted. b. Presently developed reservoir capacities are as defined by the particular owner and/or manager of the facility. c. For run-of-the-river sources, the amount available is defined variably as the 30, 7, and 1 -day low flow of the stream, at a 50-year recurrence interval. d. Assessment of the strearnflow available in each subregion, for comparison with demands for all uses, is the sum of the 7-day, 10-year low flows of undeveloped streams of greater than 5 cfs discharge. e. Groundwater availability for each subregion is as estimated by various state and federal studies completed to date. f. The subregional resource evaluation does not make allowance for potential reservoir development, unless presently slated for construction. METHODOLOGY AND RESULTS Water supply availability is defined in two different ways for use in the assessments presented in this report. First, the supply capabilities associated with each water service area are presented, and then the overall resource capability within each of the 12 subregions of the Bay Area is assessed. Appendix 5 65 Water Service Area Supply For purposes of this study, the available supply is defined for each water service area by both the source capacity, and the system ("hardware") capacity. The source capacity is the dependable supply that can be expected under drought conditions, measured in million gallons per day (mgd). The criteria vary depending on the type of supply source. The system capacity refers to the capacity,of the hardware of the system, encompassing for the 4 purposes of this study the intake pipe and pumps and the treatment plant. Source and system capacities for each water service area are listed in Table 5- 11. The smaller of either the source or hardware capacity was used to assess each system's capability to meet future demands. For water service areas supplied by reservoirs, the available supply is taken as the "safe-yield," as defined by the particular water authority. Most of the systems using reservoirs define their safe-yield by the amount of water available during the drought of record. For example, Baltimore's reservoir system has a defined safe-yield of 243 mgd, based on the 1964-65 drought; while Newport News estimates its safe-yield at 35 mgd, based on the 1954-55 drought. Only seven WSA's utilize run-of-the@river flows exclusively for their water supply: Havre de Grace and Bel Air, Maryland; Washington, D.C.; and Fredericksburg, Ashland, Richmond, and Hopewell, Virginia. These systems are particularly vulnerable to stream flow variation since drought deficiencies cannot be made up by drawing on reservoir storage. For these, the 1-, 7-, and 30-day low flows that can be expected once in 50 years were the criteria chosen to evaluate the river sources. Data from U.S. Geological Survey papers were used to derive the low-flow frequency curves for each duration. Systems that use groundwater sources usually have a safe-yield defined by either the 12- or 24-hour pumping capacity of the well system. Long-term, sustained or ultimate yield, however, is generally not defined due to the variabilities inherent in groundwater hydrology. Aquifers used as water sources are often quite extensive, sometimes underlying several counties or entire geographic provinces. Also, since they are by definition contiguous and porous, fluctuations in capacity and yield at a particular point are dependent on the overall pumping pattern. For example, yields of artesian aquifers'in much of southeastern Virginia have changed markedly due to the extensive pumping near the City of Franklin (the water table at that location has declined more than 150 feet). It is estimated that at the current rate of pumping, the flow patterns and water table profile in this area will continue to shift and not stabilize until near 202016. For these reasons, it is difficult, if not impossible, to estimate the sustained or ultimate developable yield at a single Appendix 5 66 L9 g xTpuaddv W cl- M 0 to P. H m cm 0 ct Pi rt 10 0. 0 0 0 m CL 0 m 0. m m m co 0 m m (a F@ F- ri) rt P- rt .0 rl po F@ m 10 w (a 0 cn m @al (D n cn 93 m H 0 0 :j 0 0 PC m cn 0 C., Pi ON Li I_n F- Ul X-- 3Q cn En @< co 0 CD 0 @o 0 Li H 0 0 Ln 0 @A F- M m > FA 03 ON a% rt 10 10 F@ (D pa F@ 0 0 Ul Ln @.n 03 0 0 CD I::) CD 0 rt aq aq 1 1 1 1 H. @r :r m 14 1.4 0 ft rt H r-j I-n 0 00 Ln 0 0 0 F. In co ct m C) 0 rt rt rt F. rt rt rt rt n F4 m t-h rt 14 (D 00 CL TABLE 5-11 (cont'd) Ln MUNICIPAL SOURCE AND SYSTEM CAPACITIES, mgd W.S.A. Source Capacity System Capacity SUBREGION 1 (cont'd) Source mgd how defineT mgd how defined Joppatowne 1 Wells (2) 1.1 PUMP 1.5 tr King's Heights (Odenton) Wells 1.9 PUMP 1.3 tr Maryland City Wells (3) 0.6 PUMP 1.2 it plant" Severna Park (Severndale) Wells (6) 2.7 PUMP 3.7 tr Sykesville-Freedom 2 Baltimore (Liberty Reservoir) 2.0 Agreement 1.5 tr Westminster Cranberry Run & Hull Creek 2.0 "Safe yield" 1.8 tr 1Supplemental supplies available via County owned interconnections. 2New reservoir at Piney Run to provide 3.5 mgd SUBREGION 2 Cambridge Wells (12) 4.6 PUMP 5.0 plant" Centreville Wells (3) 1.0 PUMP - Chestertown Wells (7) 0.6 PUMP 1.0 plant" Crisfield Wells (5) 1.5 PUMP 1.5 plant" Delmar Wells (3) 0.9 PUMP 1.5 plant" TABLE 5-11 (cont'd) MUNICIPAL SOURCE AND SYSTEM CAPACITIES, mgd W.S.A. Source Capacity System Capacity SUBREGION 2 (cont'd) Source mRd how defiTe-d mgd how defined Denton Wells (2) 0.7 PUMP 0.7 tr Easton Wells (6) 1.7 PUMP 2.5 11plant" Elkton Big Elk Creek 4.o "Safe yield" 1.5 tr Pokomoke City Wells (2) 0.8 PUMP - Princess Anne Wells (2) 0.4 PUMP 0.7 11plant" Salisbury Wells (11) 6.3 PUMP 6.5 $#plant" Snow Hill Wells (3) 1.0 PUMP 2.1 11plant" SUBREGION 3 No large central systems. SUBREGION 4 Seaford Wells (3) 1.5 PUMP 1.5 plant" Z:) TABLE 5-11 (cont'd) MUNICIPAL SOURCE AND SYSTEM CAPACITIES, mgd w.s.A. Source Capacity System Capacity SUBREGION 5 Source mgd how defined mgd how defin;@d-- Washington Suburban Potomac River 1 529.0 30-day, 50-yr Sanitary Commission A (avg. flow--6961 mgd) 452.0 7-day, 50-yr ( 240.0 tr 440.0 1-day, 50-yri Patuxent River (2 reservoirs) 43.0 '66 drought 65.0 tr Washington Aqueduct Potomac River 1 529.0 30-day, 50-yr 452.0 7-day, 50-yr 396.0 tr 440.0 1-day, 50-yr Alexandria F.C.W.A. 25.0 Agreement - Fairfax County Occoquan Cr. Water Authority (2 reservoirs) 65.0 "Safe yield" 100.0 tr (F.C.W.A.) Wells (31) 1.8 PUMP - Goose Creek (Fairfax City) Goose Creek (2 reservoirs) 14.4 "Safe yield" 9.5 tr 1Dependable flows will increase by 137 mgd by 1990 due to Bloomington Project. TL g xipuaddV W cn C-- r-I t7i W t, 01 m m 0 0) P) 0 x 0 H 0 :3 H P@ 0 a, H. 0 0 m P) 0 0 0 P) In ca z F@ " OQ 11 CA w H, rt a. ON m m Un 0 rt co :j OQ rt PV C: :rL. :E: :V. z @Q w m (D m m m F- F- F- F@ 0 F- F- F- F- P3 (n (n CL X- 41 F- 0 F-4 w 0 Pi m (D cn > m 00 . 0- cz 41 41 00 CD 0 0 n m 0 pa F. Cl 03 0 "d 10 10 m 14 1@ r" I 14 m GQ @.n I-n -_n M CL m 41 .19 CD En 14 co rr fD M 0 m m rt rt rt f:@ m Fh rt 14 ZL 9 xTpuaddV rn En C., C-- bd > 0 0 rA a W ft C 0 0 @d 0 Fu 0 %D H. P, 00 F6 0 H :E: :j rA rt g < rt F& rt H m m OQ Id 1-4 m rt m M tr OQ :E: > En m 10 0 H 10 C: F- m PV 0 rl (a w 00 m El w I Pd rt 0 rt > En CHI III F@ ON rt :31 rt 0 H i 0 m 0 0 r- M PC e m m @3 pi Pi Pd n M t, M rl) t1a H F- w Ul -4 H H H cn H ko 0 ON @.n 0 ON 0 0@ a% 4.1. rn 0 a M 0 m > C'j w P3 --j 0 --j 0 En H @j M I I rt cn CL CL a. C, m P) 0 m 1@ I m @-h CL Ln Ln tn @.q kA ult m Ln Un I_n F4 Cl CD 0 0 CD 0 H CD C) 0 1 1 1 1 1 1 a. I I I m 14 14 14 H pi Pi ON @o I-D cn 0 rt flt rt rt a. n m Fh 't 14 m TABLE 5-11 (cont'd) MUNICIPAL SOURCE AND SYSTEM CAPACITIES, mgd W.S.A. Source Capacity System Capacity SUBREGION 10 Source mgd how deTI-n-ed mAd how dpflnpd Newport News-Hampton 4 Reservoirs: 40.0 '54-'55 drought 56.0 tr Lee Hall Harwoods Mill Skiffes Creek Diascund (Note: includes supplemental flow from Chickahominy River) SUBREGION 11 Norfolk 3 Reservoirs: 73.0 "Safe yield" 63.0 tr Lake Burnt Mills Lake Prince Western Branch 4 deep wells and Supplemental pumpage from Nottoway & Blackwater Rivers Portsmouth 4 Reservoirs: 21.0 "Safe yield" 37.5 tr Speight's Run Lake Kilby Lake Cohoon Lake Meade 2 deep wells SUBREGION 12 Williamsburg Waller Pond 2.0 "Safe yield" 4.0 tr .(Supplemented by Newport News) TABLE 5-11 (cont'd) 41 L MUNICIPAL SOURCE AND SYSTEM CAPACITIES, mgd W.S.A. Source Capacity System Capacity SUBREGION 12 (cont'd) Source- mgd how defined mgd how defined Smithfield Wells (9) 0.7 PUMP Suffolk Portsmouth (also 2 wells in (See "Portsmouth") reserve) tr., or "plant": treatment plant capacity pipe: capacity limited by pipe size pump: pump capacity appropriation: limit of appropriation by authorizing agency "safe yield": hydrologic capability of supply source data lacking geographical point. However, estimates of the ultimate yields of entire aquifers have been made, based on recharge and transmissibilty studies. The results of studies of this type were used to derive the developable groundwater yields presented for each subregion in Table 5-12 (See also attachment 5-C). Subregional Supply In addition to the treatment of each WSA, as discussed above, the overall available freshwater resource is evaluated on a subregional basis, as summarized in Table 5-12. Groundwater, surface-flowing water, reservoirs, and diversions are addressed, where applicable. Strearnflows are listed for all free-flowing surface waters with flows of greater than 5 cfs during the 7-day, 10-year low flow and that are considered developable for municipal or industrial water supply, based on existing reports and estimates. In some instances, data were adjusted from nearby gages if no record was available for a particular stream. In addition, estimated overall groundwater availability is listed for each subregion, based on U.S. Geological Survey and Siate groundwater survey reports. Safe-yields from existing reservoir developments, if any, are also listed. A detailed accounting of surface flows, developable groundwater, and existing storage is presented in Attachments 5- B, C, and D, respectively. FUTURE NEEDS AND PROBLEM AREAS Previous sections of this report included inventories of existing water supply facilities, projections of municipal and industrial water demands, and evaluations of the freshwater resources available to meet those demands. This section includes an evaluation of the future needs (deficits) based on a comparison of the developed source and system capacities and projected demands for publicly supplied water. Thus, the magnitude and time-frame of future problem areas are identified for each water service area. It should be noted that source deficits identified for systems that are reliant on groundwater supplies reflect the limitations of the pumps only and do not wholly indicate the adequacy of the groundwater aquifers themselves. Many systems can increase their available groundwater supply by merely increasing their pumping capacity-development of alternative sources will not be required. In Chestertown, Maryland, for example, where source deficits are identified as early as 1980, it is estimated that the wells that are already in existence could probably provide twice the stated yield by merely increasing the mechanical pumping capability. Additional source development could be effected through the drilling of additional wells. All demands for the designated WSA's are increased to reflect peaks during maximum 30-, 7-, and I -day periods using the peaking factors shown in Table 5-13. These factors are consistent with values used in other studies, and with observations by others that demand fluctuations are greater in small systems ADDendix 5 75 TABLE 5-12 SUBREGIONAL FRESHWATER AVAILABILITY, mgd Safe Yield Surface Ground of Existing Subregion Waterl Water Storage Other Total 1 5702 200 254 0 1,024 2 115 750 0 865 3 - 250 - 0 250 4 50 240 - 0 290 5 6253 181 130 0 9363 6 - 234 - 0 234 7 44 72 3 0 119 8 487 75 116 0 678 9 60 110 - 0 170 10 - 8 64.54 0 72.54 11 12 94 0 106 12 82 2 0 84 lLow flow during 7-day 10-year drought, see Attachment 5-B for inventory. 21ncludes assumed ultimate allowable from Susquehanna River of 500 mgd. 3Dependable flow will increase by 137 mgd by 1990, due to Bloomington project. 4Safe yield will increase by 20 mgd with Little Creek Reservoir by 1990. Appendix 5 76 (17, 18). The diversity of uses in larger systems can act to dampen wide seasonal variation. Variable peaking factors are used for the Washington, D.C., metropolitan area to be consistent with established procedures used in many prior studies of the region (the Northeastern United States Water Supply Study, among others). Peaking factors at Hopewell were reduced due to the heavy use by industry of the public supply (84 percent). TABLE 5-13 PEAKING FACTORS FOR MUNICIPAL DEMANDS Average 30-Day 7-Day I-Day Large Systems,> 100,000 1.0 1.2 1.4 1.6 District of Columbia Metro Area 1.0 1.33 1.67 1.77 Small Systems,< 100,000 1.0 1.3 1.6 2.0 The water service areas are discussed in the following pages with respect to the identified needs in each. Also, a comparison is made between the overall subregional resource capability, as tabulated in the previous section, and the summation of all demands-municipal, industrial, institutional, and agricultural-within each subregion. Demands are classified as follows: a. Large Public Systems-7-day peak demands for all systems serving a population of greater than 2,500, including the industrial component. b. Small Public Systems-7-day peak demands for systems serving fewer than 2,500 persons. c. Industrial-fresh water demands for use in manufacturing that are not supplied through public systems. . d. Institutional-average demands from private schools, hospitals, military establishments, etc., that are not served by public systems. (see Attachment 5-E for inventory). e. Agricultural-fresh water demands for use by the rural domestic population, for livestock and poultry production, and for irrigation during the maximum month during the dryest year in 10 for vegetables and speciality crops, and the dryest year in 5 for field crops and orchards. This component is derived from the Agricultural Water Supply Appendix, and appears as a summary in Attachment 5-F. Thus, all fresh water withdrawal demands for all uses, which have been derived in a consistent manner for each subregion, are presented and compared with a measure of the available fresh water resource, including discharge of surface- flowing steams, safe-yields of existing reservoirs, and the ultimate sustained groundwater yield. The magnitude and time-frame of a potential regional Appendix 5 77 deficit can thus be identified and a basis formed for area-wide regional planning. Needs will indicate the extent to which a subregion will need reservoir development, importation of supplies from other areas, or other sourc e development, such as reuse or desalination. Needs are not presented here for cooling water consumed in electric power generation facilities, but, inasmuch as most of these will locate on brackish waters around the Bay, this appears to be a reasonable exclusion. To the extent that future power developments may consume portions of the fresh water supply, the amount should be deducted from the available resource of the particular subregion (see the Power Appendix for water demand in that sector). SUBREGION 1 Demands are presented for the 13 water service areas of Subregion I in Table 5-14, along with the developed source and system capacities of each. Projected deficits are thus identified for the 30-, 7-, and 1-day maximum demands for each WSA. Baltimore is the dominant supplier, providing an average of 245 mgd to over 1.5 million persons-nearly 75 percent of the total subregional population. With the projected growth in demand for the City, and assuming a constant 250 mgd allocation from the Susquehanna River, shortages will not occur in Baltimore during the maximum month until 2020. At existing levels of development and without supplemental supplies, significant deficits appar in Table 5-14 for many cities, most notably Aberdeen and Edgewood- Perryman in Harford County, and Maryland City in Anne Arundel County. Many systems in Harford County, however, are interconnected through a central county-owned system enabling redistribution of supplies to deficit areas. Comparing the sum of source capacities for all WSA's with the aggregated demand, shows 7-day deficits amounting to 49 mgd by 2000, increasing to 241 mgd by 2020. Aggregated demands for all freshwater uses in Subregion I are shown in Table 5-15. C6 .mparison with the total available freshwater resources, including unregulated streamflows, estimated groundwater sustained yields, safe yields of existing reservoir development, and an assumed eventual 500 mgd allocation from the Susquehanna River, indicates that the overall subregional resource is adequate through 2020. ADDendix 5 78 TABLE 5-14 FUTURE MUNICIPAL SOURCE AND SYSTEM DEFICITS, m9d SUBREGION I WATER SERVICE AREA 1980 1990 2000 2020 Capacities Avg. 30-day 7-day I-day Avg. 30-dzy 7-day - 14ay Avg. 30-day 7-day I-day Avg. 30-day 7-day I-day (source) (system) Aberdeen Demand 4.0 5.1 6.3 7.9 6.4 8.3 10.2 12.8 9.1 11.8 14.6 18.2 16.6 21.6 26.6 33.2 1.0 Source Deficit 3.0 4.1 5.3 6.9 5.4 7.3 9.2 11.8 8.1 10.8 13.6 17.2 15.6 20.6 25.6 32.2 1.5 System Deficit 2.5 3.6 4.8 6.4 4.9 6.8 8.7 11.3 7.6 10.3 13.1 16.7 15.1 20.1 25.1 31.7 Annapolis Demand 6.2 8.0 9.9 12.4 6.6 8.6 10.6 13.2 7.1 9.1 11.3 14.1 7.5 9.7 11.9 14.9 6.5 Source Deficit 0 1.5 3.4 5.9 0.1 2.1 4.1 6.7 0.6 2.6 4.8 7.6 1.0 3.2 SA 8A 5.1 System Deficit 1.1 2.9 4.8 7.3 1.5 3.5 5.5 8.1 2.0 4.0 6.2 9.0 2.4 4.6 6.8 9.8 Baltimore Demand 285 341 399 456 313 376 438 501 357 428 500 571 471 565 659 754 493 Source Deficit 0 0 0 0 0 0 0 8 0 0 7 78 0 72 166 261 500 System Deficit 0 0 0 0 0 0 0 1 0 0 0 71 0 65 159 254 Bel Air Demand 1.7 2.2 2.7 3.4 2.4 3.1 3.8 4.8 3.0 3.9 4.8 6.0 4.2 5.5 6.7 8.4 Variable Source Deficit 0 1.1 2.4 3.4 0 2.0 3.5 4.8 0 2.8 4.5 6.0 0 4.4 6A 8.4 1.5 System Deficit 0.2 0.7 1.2 1.9 0.9 1.6 2.3 3.3 1.5 2.4 3.3 4.5 2.7 4.0 5.2 6.9 Crofton Demand 1.2 1.6 1.9 2.4 1.6 2.1 2.6 3.2 1.7 2.2 2.7 3.4 1.8 2.3 2.9 3.6 1.0 Source Deficit 0.2 0.4 0.9 A.4 0.6 1.1 1.6 2.2 0.7 1.2 1.7 2.4 0.8 1.3 1.9 2.6 1.8 System Deficit 0 0 0.1 0.6 0 0.3 0.8 1.4 0 0.5 0.9 1.6 0 0.5 1.1 1.8 Edgewood Demand 2.1 3.1 3.3 4.1 3.2 4.1 5.1 6.4 4.6 6.0 7.3 9.1 8.6 11.2 13.8 17.2 (Perryman) 1.9 Source Deficit 0.2 1.2 1.4 2.2 1.3 2.2 3.2 4.5 2.7 4.1 5.4 7.2 6.7 9.3 11.9 15.3 4.0 System Deficit 0 0 0 0.1 0 0.1 1.1 2.4 0.6 2.0 3.3 5.1 4.6 7.2 9.8 13.2 Havre de Grace Demand 1.6 2.1 2.6 3.2 1.8 2.3 2.9 3.6 1.8 2.3 2.8 3.5 2.0 2.6 3.2 4.0 3.0 Source Deficit 0 0 0 0.2 0 0 0 0.6 0 0 0 0.5 0 0 0.2 1.0 3.0 System Deficit 0 0 0 0.2 0 0 0 0.6 0 0 0 0.5 0 0 0.2 1.0 Joppatowne Demand 0.9 1.2 1.4 1.8 0.9 1.2 1.4 1.8 1.0 1.3 1.6 2.0 1.2 1.6 1.9 2.4 1.1 Source Deficit 0 0.1 0.3 0.7 0 0.1 0.3 0.7 0 0.2 0.5 0.9 0.1 O@5 0.8 1.3 1.5 System Deficit 0 0 0 0.3 0 0 0 0.3 0 0 0.1 0.5 0 0.1 0.4 0.7 > Maryland City Demand 1.5 2.0 2.4 3.1 2.1 2.7 3.4 4.3 2.7 3.5 4.4 5.4 4.1 5.4 6.6 8.3 ":I 0.6 Source Deficit 0.9 1.4 1.8 2.5 1.5 2.1 2.8 3.7 2.1 2.9 3.8 4.8 3.5 4.8 6.0 7.9 (D @j 1.2 System Deficit 0.3 0.8 1.2 1.9 0.9 1.5 2.2 3.1 1.5 2.3 3.2 4.2 2.9 41 5.4 7.1 TABLE 5-14 (Contd) FUTURE MUNICIPAL SOURCE AND SYSTEM DEFICITS, mild Ui SUBREGION I WATER SERVICE AREA 1980 1990 2000 2020 Capacities Avg. 3G-day 7-day I-day Avg. 30-day 7-day I-day Avg. 30-day 7-day I-day Avg. 30-day 7-day I-day (source) (system) Kings Heights Demand 0.8 1.0 1.3 1.6 1.1 1.4 1.8 2.2 1.3 1.7 2.1 2.6 1.8 2.3 2.9 3.6 (Odenton) 1.9 Source Deficit 0 0 0 0 0 0 0 0.3 0 0 0.2 0.7 0 0.4 1.0 1.7 1.3 System Deficit 0 0 0 0.3 0 0.1 0.5 0.9 0 0.4 0.8 1.3 0.5 1.0 1.6 2.3 Severna Park Demand 3.1 4.0 5.0 6.2 4.4 5.7 7.0 8.8 5.9' 7.7 9.4 11.8 9.2 12.0 14.7 18.4 (Severndale) 2.7 Source Deficit 0.4 1.3 2.3 3.5 1.7 3.0 4.3 6.1 3.2 5.0 6.7 9.1 6.5 9.3 12.0 15.7 3.7 System Deficit 3.0 0.3 1.3 2.5 0.7 2.0 3.3 5.1 2.2 4.0 5.7 8.1 5.5 8.3 11.0 14.7 Sykesville- Demand 0.9 1.2 1.4 1.8 1.4 1.8 2.2 2.8 1.6 2.1 2.6 3.2 2.3 3.0 3.7 4.6 Freedom 2.0 Source Deficit 0 0 0 0 0 0 0.2 0.8 0 0.1 0.6 1.2 0.3 1.0 1.7 2.6 1.5 System Deficit 0 0 0 0.3 0 0.3 0.7 1.3 0.1 0.6 1.1 1.7 0.8 1.5 2.2 3.1 Westminster Demand 1.6 2.1 2.6 3.3 2.1 2.8 3.3 4.2 2.4 3.0 3.8 4.7 3.0 3.8 4.7 5.9 2.0 Source Deficit 0 0.1 0.6 1.3 0.1 0.8 1.3 2.2 0.4 1.0 1.8 2.7 1.0 1.8 2.7 3.9 1.8 System Deficit 0 0.3 0.8 1.5 0.3 1.0 1.5 2.4 0.6 1.2 2.0 2.9 1.2 2.0 2.9 4.1 Total Demand 311 375 440 507 347 420 492 569 399 483 567 655 533 646 759 879 518 Source Deficit 0 0 0 0 0 0 0 51 0 0 49 137 15 128 241 361 528 System Deficit 0 0 0 0 0 0 0 41 0 0 39 127 5 118 231 351 TABLE 5-15 AGGREGATED DEMANDS VERSUS FRESHWATER RESOURCE, mgd SUBREGION 1 1970 1980 1990 2000 2020 Large Public Systems 367 440 492 567 759 Small Public Systems 13 24 34 40 45 Industrial 17 17 13 12 13 Institutional 14 14 14 14 14 Agricultural 21 58 60 62 70 TOTAL Demand 432 553 613 695 901 Fresh Water Supply 1,024 1,024 1,024 1,024 1,024 Needs 0 0 0 0 0 SUBREGION 2 The Eastern Shore of Maryland contains 12 water service areas. All the systems use groundwater sources except in the fringes of the Piedmont at Elkton where surface water is used. Table 5-16 details source and system deficits that can be expected with present capacities. Four systems will require source development to meet 30-day maximum demands by 1980: Chestertown, Crisfield, Cambridge, and Easton. Cumulative source capacity for all systems in the subregion will be 9.1 mgd short of the 7-day maximum demand by 2000, increasing to 18.0 mgd in 2020. Comparing the overall availability of freshwater with the demands for all uses in Table 5-17, it can be seen that supplies, if developed, should be adequate through 2020. It should be noted that agriculture accounts for nearly 87 percent of the year 2020 demand, of which about 79 percent is for irrigation needs during a dry year. SUBREGION 3 The two counties that comprise the Virginia portion of the Eastern Shore are predominantly rural in character and contain only public water systems serving fewer than 2,500 persons. Table 5-18 details the aggregated demands for all uses for Subregion 3. Even with "dry-year" irrigation demands, which are the major demand components, groundwater resources are a more-than- adequate supply source for this area. Appendix 5 81 ZE xTpuaddv tv tv r. tn m pp p p p p p p t., p p p p p p p p p p p p p p p p r" ER 9 XipuaddV tv tv p p bo i4 p p M 0 bl, p p TABLE 5-17 AGGREGATED DEMANDS VERSUS FRESHWATER RESOURCE, mgd SUBREGION 2 1970 1980 1990 2000 2020 Large Public Systems 22.2 26.1 28.3 32.5 41.4 Small Public Systems 7.7 12.0 17.2 23.7 38.9. Industrial 31.1 30.9 27.6 30.3 37.4 Institutional 2.0 2.0 2.0 2.0 2.0 Agricultural 45.6 108.6 179.6 250.6 744.9 TOTAL Demand 109 180 255 339 865 Fresh Water Supply 865 865 865 865 865 Needs 0 0 0 0 0 TABLE 5-18 AGGREGATED DEMANDS VERSUS FRESHWATER RESOURCE, mgd SUBREGION 3 1970 1980 1990 2000 2020 Large Public Systems 0 0 0 0 0 Small Public Systems 1.3 1.6 2.0 2.4 3.5 Industrial 1.9 1.6 1.4 1.4 1.6 Institutional - - - - - Agricultural 17.7 69.7 61.4 53.3 43.3 TOTAL Demand 21 73 65 57 48 Fresh Water Supply 250 250 250 250 250 Needs 0 0 0 0 0 SUBREGION 4 Seaford is the only water servcie area in the Delaware portion of the Chesapeake Bay Study Area, as shown in Table 5-19. With the presently developed groundwater sources, Seaford should be able to meet average demands until 2000, but may need source development by 1990 to meet maximum 30-day demands. Aggregated demands for all uses, including industrial, agricultural, and municipal, are presented in Table 5-20 in Appendix 5 84 S XTPU@ddV > Z 10 %0 4 TABLE 5-20 AGGREGATED DEMANDS VERSUS FRESHWATER RESOURCE, mgd SUBREGION 4 1970 1980 1990 2000 2020 Large Public Systems 1.3 1.5 1.9 2.1 3.4 Small Public Systems 1.7 2.9 4.4 5.9 10.4 Industrial 62.9 41.7 17.3 19.8 28.3 Institutional Agricultural 17.8 104.4 111.2 120.4 146.8 TOTAL Demand 84 151 135 148 189 Fresh Water Supply 290 290 290 290 290 Needs 0 0 0 0 0 comparison with the estimated overall freshwater availability of 290 mgd. A small amount of freshwater flow in the Nanticoke River is included, but groundwater alone, which constituted 83 percent, or 250 mgd, of the available supply, is sufficient to meet 2020 demands. SUBREGION 5 This subregion contains the Washington, D.C., metropolitan area where seven water service areas provide water to about 2.8 million persons or about 97 percent of the total subregional population. Major use is made of the Potomac River by the Washington Aqueduct Division of the Corps of Engineers, which services the myriad of needs of the District of Columbia and parts of Northern Virginia. The Washington Suburban Sanitary Commission (WSSC) also uses the Potomac in conjunction with two reservoirs developed on the Patuxent to serve large portions of Prince Georges and Montgomery Counties, Maryland. A third major system is the Fairfax County Water Authority (FCWA) which provides water from Occoquan Creek to large portions of Fairfax County, parts of Prince William County, and the City of Alexandria. Deficits for each WSA are presented in Table 5-21 based on a comparison of source and system capacities and projected demands. For evaluation of the Potomac River source, demands for Washington Aqueduct and the WSSC are combined. Source capacities for the two systems are then combined: 30-day, 7- day, and 1-day minimum flows of the Potomac and the safe yield of the two reservoirs on the Patuxent River. Source capacity is thus defined as 572, 495, ADpendix 5 86 LS g xTpuaddV iV 2 V :6 c 0 T@ g P P tv cv a 4 a 1 t@ c g, 'a i@ bo @11 i@ @4 @11 P. Z@ z:l 91 bo P4. pl. @o @o bo t4 "M and 483 mgd for the 30-, 7-, and 1-day low flows, increasing to 709, 632, and 620 mgd, respectively, by 1990, due to the scheduled completion of the Bloomington Lake project. Source deficits amount to 154 mgd during 7-day periods of maximum demand in 1980, increasing to 286 and 670 mgd by 2000 and 2020, respectively. The urgent need for source development is highlighted by the fact that on at least one occasion maximum day demands exceeded the recorded low flow in the Potomac River. Source deficits are also of concern for FCWA and Fairfax City where average day shortages appear by 1980. The sum of demands for all WSA's in the subregion, when compared with the developed source and system capacities, indicates overall 7-day source deficits of 235 mgd by 1980 and 304 mgd by 1990, leaping to 1, 206 mgd by 2020. Aggregated demands for all uses, including public, industrial, and irrigation, are presented in Table 5-22 for Subregion 5. When compared with the available ground and surface supplies and yields of existing reservoirs, significant deficits are identified. Needs amounting to 36 mgd are calculated for the subregion as a whole by 1990, growing to 1015 mgd by 2020. TABLE 5-22 AGGREGATED DEMANDS VERSUS FRESHWATER RESOURCE, mgd SUBREGION 5 1970 1980 1990 2000 2020 Large Public Systems 638 823 1,029 1,268 1,931 Small Public Systems 13 6 9 13 28 Industrial 1 2 3 3 6 Institutional 5 5 5 5 5 Agricultural 15 33 63 86 118 TOTAL Demand 869 1,109 1,375 2,088 Fresh Water Supply 936 936 1,073' 1,073 1,073 Needs 0 0 36 3.02 1,015 'Dependable supply expected to increase by 137 mgd by 1990 due to Bloom- ington Project. Appendix 5 88 TABLE 5-23 FUTURE MUNICIPAL SOURCE AND SYSTEM DEFICITS, angst SUBREGION 6 WATER SERVICE AREA 1980 1990 2000 2020 Capacities Avg. 30-day 7-day I-day Avg. 30-day 7-day 1-day Avg. 30-day 7-day I-day Avg. 30-day 7-day 1-day (source) (system) Leonardtown Demand 0.3 0.4 0.5 0.6 0.3 0.4 0.5 0.7 0.3 0.4 0.5 0'7 0.5 0.7 0.8 1.0 0.6 Source Deficit 0 0 0 0 0 0 0 0.1 0 0 0 0.1 0 0.1 0.2 0.4 0.6 System Deficit 0 0 0 0 0 0 0 0.1 0 0 0 0.1 0 0.1 0.2 0.4 Lexington Park Demand 1.6 2.1 2.7 3.2 2.7 3.5 4.3 5.4 4.1 5.3 6.6 8.2 8.7 11.4 13.9 17.4 1.4 Source Deficit 0.2 0.7 1.3 1.2 1.3 2.1 2.9 4.0 2.7 3.9 5.2 6.8 7.3 10.0 12.5 16.0 1.4 System Deficit 0.2 0.7 1.3 1.2 1.3 2.1 2.9 4.0 2.7 3.9 5.2 6.8 7.3 10.0 12.5 16.0 Waldorf Demand 1.5 2.0 2.4 3.0 2.7 3.5 4.3 5.4 4.2 5.4 6.7 8.4 9.0 11.8 14.4 18.0 1.4 Source Deficit 0.1 0.6 1.0 1.6 1.3 2.1 2.9 4.0 2.8 4.0 5.3 7.0 7.6 10.4 13.0 16.6 1.4 System Deficit 0.1 0.6 1.0 1.6 1.3 2.1 2.9 4.0 2.8 4.0 5.3 7.0 7.6 10.4 13.0 16.6 Total Demand 3.4 4.5 5.6 6.8 5.7 7.4 9.1 11.5 8.6 11.1 13.8 17.3 18.2 23.9 29.1 36.4 3.4 Source Deficit 0 1.1 2.0 3.4 2.3 4.0 5.7 8.1 5.2 7.7 10.4 13.9 14.8 20.5 25.7 33.0 3,4 System Deficit 0 1A 2.0 3.4 2.3 4.0 5.7 8.1 5.2 7.7 10.4 13.9 14.8 20.5 25.7 33.0 % SUBREGION 6 The three counties comprising Subregion 6 lie entirely in the Coastal Plain and rely almost entirely on groundwater sources for their water supply. Nineteen percent of the population is served within three water service areas. As shown in Table 5-23, Waldorf and Lexington Park will require source and system development by 1980 to meet 30-day maximum demands. The cumulative 7- day maximum demands for the three WSA's show that incremental source and system developments of 5.7 mgd will be required by 1990, increasing to 10.5 by 2000 and 25.7 by 2020. Table 5-24 compares the aggregated demands for all uses in the subregion with the overall developable freshwater resource. Even with "dry-year" irrigation requirements, the subregion has abundant supplies of groundwater to meet its projected needs. TABLE 5-24 AGGREGATED DEMANDS VERSUS FRESHWATER RESOURCE, mgd SUBREGION 6 1970 1980 1990 2000 2020 Large Public Systems 3.5 5.6 9.1 13.8 29.1 Small Public Systems 3.2 5.3 9.4 15.4 24.8 Industrial 0.7 1.2 1.9 3.0 6.5 Institutional 3.0 3.0 3.0 3.0 3.0 Agricultural 8.2 20.4 53.2 85.9 116.9 TOTAL Demand 19 35 77 121 180 Fresh Water Supply 234 234 234 234 234 Needs 0 0 0 0 0 SUBREGION 7 This small tricounty area in the Virginia portion of the Washington Econoraic Area, is dominated by the population and industrial concentra- tion at Fredericksburg, which comprises the subregion's only WSA. The source of supply for Fredericksburg is the unregulated Rappahannock River which yields 14.8 mgd during the 30-day duration, 50-year low flow. As shown in Table 5-11, flows decrease to 9.0 and 7.7, for 7-day and I-day low flows, respectively. In Table 5-25 a comparison between projected demands and the available river flow shows that the Rappahannock is sufficient to meet 30-day maximum demands through 2020. Appendix 5 90 s xTpuaddv Aggregated demands for all uses in the subregion are compared with the presently available resource in Table 5-26. No deficits are shown to occur through the year 2020. It is of note, however, that of the 81.5 mgd demand projected for 2020, about 60 percent is for the needs of industry. SUBREGION 8 This five-county area is defined as the Richmond SMSA. Three major public systems-Richmond, Hopewell, and that serving Colonial Heights and Petersburg-provide service to nearly 77 percent of the total subregional population. Table 5-27 lists the WSA's, their projected demands, and the deficits expected based on presently developed source and system capacities. The Appomattox River Water Authority's development at Lake Chesdin on the Appomattox River has a rated safe yield of 100 mgd, which is shown to be adequate for the present water service area far beyond 2020. The James River at Richmond is also sufficient to meet projected needs for the City of Richmond through 2020. Large deficits appear at Hopewell, however, when demands are compared with the natural flow of the Appomattox River. Service to industry at Hopewell amounted to 21.8 mgd, or about 85 percent of all water supplied by the Virginia American Water Company in 1970, and this grows (assuming Hopewell will provide a similar subregional share in the future) to 32.0 mgd by TABLE 5-26 AGGREGATED DEMANDS VERSUS FRESHWATER RESOURCE, mgd SUBREGION 7 1970 1980 1990 2000 2020 Large Public Systems 4.2 4.9 5.8 6.7 9.3 Small Public Systenis 1.8 3.2 5.1 7.8 17.6 Industrial 27.2 28.1 27.8 32.1 49.1 Institutional 0.6 0.6 0.6 0.6 0.6 Agricultural 2.4 4.5 5.2 5.9 4.9 TOTAL Demand 36 41 45 53 82 Fresh Water Supply 119 119 119 119 119 Needs 0 0 0 0 0 Appendix 5 92 E6 9 XTPuaddv > 7 o 2 E ir It. m rn C@0 0 to c @2 @c L> L) 2020 (see Table 5-7). It should be noted that the supply in the Appomattox River is supplemented in the vicinity of the intake at Hopewell by the backup of James River water due to tidal influence. Thus, there is an unknown, but perhaps substantial, increment in the quantity of water ultimately available. Aggregated demands for all uses, including municipal, industrial, and agricultural, are shown in Table 5-28 for Subregion 8. Comparison with the sum of stream discharge, existing safe yield of reservoirs, and of developable groundwater yields, shows overall deficits emerging only after the year 2000. The principal component of demand is that of self-supplied industry, comprising nearly 70 percent of the use in 1970. This decreases to 50 percent, or 397 mgd, by the year 2020. SUBREGION 9 This predominantly rural, lightly developed area extends from the James River in the south to the shores of the Potomac River in the north. Despite its size, only one public Water Service Area is located in Subregion 9 - West Point in King William County. Table 5-29 shows the projected demands for this system and the deficits to be expected based on the present capacities. Groundwater supplies appear sufficiently developed to meet even maximum day demands through the year 2000. TABLE 5-28 AGGREGATED DEMANDS VERSUS FRESHWATER RESOURCE, mgd SUBREGION 8 1970 1980 1990 2000 2020 Large Public Systems 104 116 137 169 260 Small Public Systems 8 15 22 31 54 Industrial 265 248 231 261 397 Institutional I I I I I Agricultural 7 30 51 72 81 TOTAL Demand 385 410 442 534 793 Fresh Water Suppy 678 678 678 678 678 Needs 0 0 0 0 115 Appendix 5 94 TABLE S-29 FUTURE MUNICIPAL SOURCE AND SYSTEM DEFICITS, mgd SUBREGION 9 WATER SERVICE AREA 1980 1990 2000 2020 Capacities Avg. 30-day 7-day I-day Avg. 30-day 7-day I-day Avg. 30-day 7-day I-day Avg. 30-day 7-day I-day (source) (system) West Point Demand 0.3 0.4 0.5 0.6 0.4 0.5 0.6 0.8 0.4 0.5 0.6 0.8 0.6 0.8 1.0 1.2 0.9 Source Deficit 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.1 0.3 0.9 System Deficit 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.1 0.3 Freshwater demands for agriculture-related purposes are expected to increase by more than ten-fold by 2020. Table 5-30 details these and other demands for all uses, the sum of which are then compared with the overall freshwater resource of the subregion. No shortages are identified, indicating the relative wealth of water supplies that are available for use in the area. TABLE 5-30 AGGREGATED DEMANDS VERSUS FRESHWATER RESOURCE, mgd SUBREGION 9 1970 1980 1990 2000 2020 Large Public Systems 0.4 0.5 0.6 0.6 1.0 Small Public Systems 4.0 5.9 7.3 9.7 15.8 Industrial 16.1 13.1 11.9 12.6 17.6 .Institutional 0.1 0.1 0.1 0.1 0.1 Agricultural 4.0 18.5 33.2 47.9 51.1 TOTAL Demand 25 38 53 71 86 Fresh Water Supply 170 170 170 170 170 Needs 0 0 0 0 0 SUBREGION 10 Public water supply in this subregion, located near the mouth of the James River at Chesapeake Bay, is dominated by the system managed by Newport News, which is the only Water Service Area in the subregion. Table 5-31 compares projected demands on the Newport News system with the safe-yield of developed sources and its system ("hardware") capacity. Deficits are indicated by 1980 in both categories, but system deficits are reduced for 1990 due to expected completion of the Little Creek pumped storage facility, which will store water from the nearby Chickahominy River, during periods of peak flow. Source depletion will nonetheless occur again for Newport News by 2000. Continuing source and system development is seen as a necessity for this area. Appendix' 5 96 TABLE 5-31 FUTURE MUNICIPAL SOURCE AND SYSTEM DEFICITS, mgd SUBREGION 10 WATER SERVICE AREA 1980 1990 2000 2020 Capacities Avg. 3G-day 7-day I-day Avg. 30,day 7-day I-day Avg. 30-day 7-day I-day Avg. 30-day 7-day 1-day (source) (system) Newport News- Demand 36.8 44.2 51.5 58.9 42.3 50.8 59.2 67.7 50.0 60.0 70.0 80.0 67.5 81.0 94.5 108 Hampton 40.0' Source Deficit 0 4.2 11.5 18.9 0 0 0 7.7 0 0 10.0 20.0 7.5 21.0 34.5 48.0 56.0 System Deficit 0 0 0 2.9 0 0 3.1 11.7 0 4.0 14.0 24.0 11.5 25.0 38.5 52.0 'Safe yield will increase to 60 mgd by 1990. Aggregated demands for all uses, including municipal, self-supplied industrial, and agricultural, are presented in Table 5-32. Assuming complete development of groundwater and completion of the pumped storage facility at Little Creek, supplies should be adequate through 2000 for the subregion as a whole. Additional needs.for source development of about 12 mgd will be required by 2020. TABLE 5-32 AGGREGATED DEMANDS VERSUS FRESHWATER RESOURCE, mgd SUBREGION 10 1970 1980 1990 2000 2020 Large Public Systems 38.2 51.5 59.2 70.0 94.5 Small Public Systems 0.7 1.2 L8 2.4 1.6 Industrial 5.0 2.9 23 2.3 2.9 Institutional 4.2 4.2 4.2 4.2 4.2 Agricultural 1.4 1.5 1.3 1.1 1.6 TOTAL Demand 50 61 69 80 105 Fresh Water Supply 73 73 931 93 93 Needs 0 0 0 0 12 1 Reflects increase expected with completion of Little Creek pumped storage facility. SUBREGION 11 Two major systems supply the water to the urban population of this subregion: Norfolk and Portsmouth. Through these systems Virginia Beach, City of Chesapeake, and Suffolk (Subregion 12) are also served. Projected source and system deficits, based on existing development, are shown in Table 5-33. immediate needs for source development are indicated for Portsmouth, and the Norfolk system requires increases in both source and system capacities. Together the two systems have maximum 7-day deficits of 21 mgd in 1980, increasing to 63 mgd by 2000, and 117 mgd by 2020. The location of the subregion on coastal saline waters, and the development of nearly all nearby sources, will necessitate large scale development at some distance from the urban center. Annendix 5 98 TABLE 5-33 FUTURE MUNICIPAL SOURCE AND SYSTEM DEFICITS, mgd SUBREGION I I WATER SERVICE AREA 1980 1990 2000 2020 Capacities Avg. 30-day 7-day I-day Avg. 30-day 7-day I -day Avg. 30-day 7-day I -day 77g. 30-day 7-day I-day (source) (system) Norfolk System Demand 61.7 74.0 86.4 98.7 70.8 85.0 99.1 113.3 83.0 99.4 115.5 132.5 108.9 130 152 174 73.0 Source Deficit 0 1.0 13.4 25.7 0 12.0 26.1 40.3 10.0 26.4 42.5 59.5 35.9 57.0 79.0 101 63.0 System Deficit 0 11.0 23.4 35.7 7.8 22.0 36.1 50.3 20.0 36.4 52.5 69.5 45.9 67.0 89.0 Ill Portsmouth System Demand 20.8 25.0 29.1 33.3 25.0 30.0 35.0 40.0 30.0 36.0 42.0 48.0 42.1 50.5 58.9 67.4 (Incl. Suffolk) 21.0 Source Deficit 0 4.0 8.1 12.3 4.0 9.0 14.0 19.0 9.0 15.0 21.0 27.0 20.8 29.2 37.5 45.9 37.5 System Deficit 0 0 0 0 0 0 0 0 0 0 4.5 10.5 4.6 13.0 21.4 29.9 Total Demand 82.5 99.0 115.5 132.0 95.8 115.0 134.1 153.3 113.0 135.4 157.5 180.5 151.0 180.5 210.9 241.4 94.0 Source Deficit 0 5.0 21.5 38.0 1.8 21.0 40.1 59.3 19.0 41.4 63.5 86.5 57.0 86.5 116.9 147.4 100.5 System Deficit 0 0 15.0 31.5 0 14.5 33.6 52.8 12.5 34.9 57.0 80.0 50.5 80.0 110.4 140.9 t.o Demands for water for all uses are aggregated in Table 5-34 and compared with the estimated overall available freshwater resource from groundwater sources and existing reservoir development. Publicly supplied water remains the largest component of demand through 2020. The overall amount of freshwater internally available within the subregion will run about 22 mgd short of demand by 1980. This deficit will increase to 39 mgd by 1990, and 114 mgd by 2020. TABLE 5-34 AGGREGATED DEMANDS VERSUS FRESHWATER RESOURCE, mgd SUBREGION 11 1970 1980 1990 2000 2020 Large Public Systems' 92.7 111.1 128.6 150.5 199.9 Small Public Systems 1.1 1.6 2.4 3.4 5.3 Industrial 3.8 2.5 2.0 2.0 2.8 Institutional' - - - - - Agricultural 6.2 12.8 12.2 11.6 11.9 TOTAL Demand 104 128 145 168 220 Fresh Water Supply 106 106 106 106 106 Needs 0 22 39 62 114 'Not including Suffolk. 'All publicly supplied. SUBREGION 12 Water service areas at Suffolk, Smithfield, and Williamsburg represents the major cities in this largely rural subregion. Table 5-35 details the projected growth in demand for each WSA and identifies source and system deficits to be expected under current capacities. Immediate shortages are identified for Williamsburg, but it should be noted that supplemental supplies through the Newport News system, unaccounted for here, are provided to Williamsburg on a regular basis. Deficits identified can thus be interpreted as the allocation needed from Newport News in lieu of other source development. Tourism causes large fluctuations in demand at Williamsburg. Smithfield will require only modest source and system development to meet needs in 1990. Since Appendix 5 100 TOT S xTpuaddV > EL 8, > > lo 91 Z"i 2. 2. 2. > z 0 bo b L, b po F, I z:l future needs for public water supply in Suffolk will be met through the Portsmouth system, demands for these two service areas are combined for purposes of this report. Aggregated demands for all uses within the subregion are listed in Table 5-36 and compared with the overall available freshwater supply. Shortages totaling 90 mgd by 1990, and 315 mgd by 2020, are due mainly to expected industrial growth. Since most of the Chesapeake Bay freshwater drainage has been already developed for use in Subregion 11, the listed freshwater supply is confined mostly to the potential groundwater yield. Drainage of the Nottoway and Blackwater Rivers south into North Carolina presents a substantial additional source for the southern counties of Subregion 12, and indeed, is being actively sought as a source for Norfolk and Portsmouth. TABLE 5-36 AGGREGATED DEMANDS VERSUS FRESHWATER RESOURCE, mgd SUBREGION 12 1970 1980 1990 2000 2020 Large Public Systems' 7.4 11.8 14.0 17.1 24.5 Small Public Systems 3.6 5.3 7.3 10.3 18.1 -Industrial 49.7 64.3 93.3 135.6 277.9 Institutional 0.1 0.1 0.1 0.1 0.1 Agricultural 7.0 19.0 59.8 100.5 78.7 TOTAL Demand 68 100 174 263 399 Fresh Water Supply 84 84 84 84 84 Needs 0 16 90 179 315 'Including Suffolk. Appendix 5 102 SENSITIVITY ANALYSIS The demands for future water supply identified in the previous chapter were derived on the basis of certain assumptions. These assumptions were needed in order to transform and simiplify the many uncertainties of the future into a single set of demand projections that reflect the "best estimate" of future conditions. While many assumptions were used in Chapter III to arrive at an estimate of future water needs, it was felt that two of the more basic determinants of water demand merited additional consideration. These are the topic of this chapter. First, the sensitivity of the projections of municipal water demand presented in Chapter III are analyzed in terms of changing from Series C OBERS projections of economic activity and population to those of Series E. Second, consideration is given to the future improvements in water reuse in manufacturing that may evolve as manufacturers seek to comply with requirements of the 1972 Amendments to the Federal Water Pollution Control Act (P.L. 92-500). IMPACT OF POPULATION CHANGES ON MUNICIPAL WATER DEMANDS In making economic and demographic projections for the Chesapeake Bay Study Area, a program of economic measurement, analysis, and projection conducted by the Bureau of Economic Analysis (BEA) - formerly the Office of Business Economics (OBE) - of the U.S. Department of Commerce, and the Economic Research Service (ERS) of the U.S. Department of Agriculture was used. The OBERS program, as it has come to be called, deals with the economic activity of the entire Nation and seeks to provide a regional economic information system covering both the past and the future. The OBERS historical and projected data form a National economic framework within which a region's present and future levels of economic development can be assessed and compared with those of other regions. In 1967, the Bureau of the Census developed four sets of projections, Series A, B, C, and D, which assumed varying, fertility rates. By December 1972, the Census Bureau had abandoned the Series A and B projections and had added Series E and F. At the time the Existing Conditions Report was developed the Water Resources Council (WRC) required that all Federal agencies involved in water resources planning use the OBERS Series C projections of population, income, employment, earnings and output. These projections are Appendix 5 103 presented in a multi-volume series of reports entitled the 1972 OBERS Projections - Regional Economic Activity in the U.S. Starting in 1974 however, WRC directed that agencies involved in water resource planning use the Series E projections (generally, the E Series assumes lower fertility rates as well as less defense spending than the C Series). These Series E projections, published in a seven-volume series in April 1974, were derived from more recent economic and demographic data. Both Series of reports served as basic analytical frameworks for the assessment of the economic implications of proposed water and related land resource development activities in the United States. Appendix 3-Economic and Social Profile includes both the Series C and E projections of population and employment for the Study Area. As noted earlier, the Series C projections are considered to be the baseline or reference projections for this Report since the majority of the resource projections, including water supply demands, were made prior to the adoption of the Series E projections. As shown on Table 5-37, the Series E projections are based on slightly differing assumptions from Series C. It is expected that water use in public systems would be less than expected under Series C assumptions if conditions implicit in, the use of Series E projections are in fact realized. Of the two basic determinants of municipal water use, population is the variable with the greatest influence on water use within the cities. Per capita use is the other variable that, when multiplied by population, yields demand. The per capita use rates that would develop under the Series E assumptions would not be expected to differ significantly from those that would develop under Series C. This is because the factors which influence the character of a community, and which also influence per capita demand (i.e., housing density, per capita income, type and extent of commercial activity, etc.) are felt to be largely insensitive to small changes in population. Also, changes that may occur in the industrial component of municipal demand are felt to be largely reflected in the population differences between Series C and Series E. The population projections by OBERS are derived from National and regional figures on employment and earnings, and as such, are considered to be reflections of future industrial activity. Population projections, therefore, remain as the single most important and influential of the many determinants of water use in the cities. Table 5-38 provides a comparison of the large system water demands based on the differences between the Series C and Series E population projections. Differences in the demands shown in the table are directly proportional to the differences in population between Series E and Series C. Appendix 5 104 TABLE 5-37 A COMPARISON OF OBERS SERIES C AND SERIES E PROJECTIONS Item Series C Series E Growth of Fertility rate of 2,800 Gradual decline of fertility rate Population children per 1,000 women from 2,800 to the "replacement Al, fertility rate" of 2,100 children per 1,000 women. Military Projects a decline to 2.07 Projects a decline to 1.57 million Establishment million people by 1975 persons by 1975 and thereafter and thereafter a con- a constant (due to smaller mili- stant. tary establishment and the result- ant smaller need for equipment and supplies, a significantly slow rate of growth in the defense- related manufacturing industries is anticipated). Hours Worked Hours worked per em- Hours worked per employee per Per Year ployee per year are year are projected to decline at projected to decline at 0.35 percent per year. 0.25 percent peryear. Product Per Projected to increase Projected to increase 2.9 percent Man-Hour 3.0 percent per year. per year. Earnings Per Earnings per worker in the individual industries at the na- Worker tional level are projected to converge toward the combined rate for all industries more slowly in the Series E projections than in the Series C projections. Employed Projected to increase Projected to be between 43 and Population from 40 to 41 percent 45 percent of the total population of the total population. (higher percentages with the E Series reflects expected higher participation rates by women). As shown on Table 5-38, the majority of the subregions show reduced water demands using the Series E population projections. The most significant reductions occur in the Baltimore Subregion where a 30 percent reduction or 158 mgd is realized by the year 2020. This large decrease is attributed to reductions in population that result from a slower growth in defense-related industries as projected under Series E. Lesser declines in 2020 demand of 17, 15, and 9 percent are noted for the Richmond, Newport News and Norfolk Subregions, respectively. Appendix 5 105 I Only Subregions 5, 6, and 7, which are components of the Washington Economic Area, show larger water demands under Series E than under Series C, however, this only occurs in certain goal years. These larger demands are due primarily to larger than expected population and employment increases in this Economic Area during the two additional years of the observation between the release of the Series C and E projections. By the year 2020, water demands under series E are shown to be less for all subregions. Periodically, between censuses, the Bureau of Census publishes estimates of population trends in the United States. An analysis of current trends in the Bay Area through 1975 is presented as Attachment 5-G. There is conflicting evidence to indicate the preferability of either Series C or Series E projections. Five of the subregions in the Bay Area (Numbers 3, 4, 9, 11, and 12) show growth in direct disagreement with the Series E trends, while estimated populations in Subregions 5, 6, 7, and 8 indicate trends that are in the same direction as Series E, but that are much more pronounced. Only Subregions 1, 2, and 10 indicate trends that are intermediate to the forecasts of Series C and E. In summary, it should be noted that the water demands to be met by the municipal systems vary directly with the population served. With specific regard to the differences between water demands under the Series C and E OBERS projections, it is expected that the total municipal demands in the Bay Region would be between 4 and 7 percent lower under the Series E assumptions during the planning period (1980 to 2020). IMPACT OF WATER REUSE ON INDUSTRIAL DEMANDS Projections of water demands for use in manufacturing were presented in Chapter 111. It was assumed that improvements in water reuse and recycling will occur in the future as industries seek to reduce pollutant discharges and/ or reclaim by-products from their wastewaters. Under the baseline industrial projections (Projection Set 3) intake demands were found to decline slightly, from about 1,600 mgd in 1970 to around 1,300 mgd by the year 1990. Projections subsequently increase to about 1,800 mgd by 2020 as industrial water demands increase at a faster rate than the assumed technological advances. In 1970, large water users (10 mgy or more) used recirculated supplies to provide 38.7 percent of the gross water needed for production. By 1990, this is shown to increase to 77.6 percent, and by 2020 to 89.6 percent. However, even more impressive recycling rates may occur dependent on the manner in which industry responds to the provisions of the 1972 Amendments to the Federal Water Pollution Control Act (P.L. 92-500). This section is an analysis of the sensitivity of industrial water use projections to changes that may occur in recycling rates in industrial water use. A complete ADDendix 5 106 TABLE 5-38 WATER USE IN MAJOR SYSTEMS UNDER SERIES E POPULATION PROJECTIONS, mgd Subregion Series 1980 1990 2000 2020 1. Baltimore, SMSA C 311 347 399 533 E 281 297 320 375 2. Non-SMSA, MD C 16.3 17.7 20.3 25.9 E 15.1 15.2 16.4 19.5 3. Non-SMSA, VA C 0 0 0 0 E 0 0 0 0 4. Sussex Co., DE C 1.0 1.2 1.4 1.9 E 1.0 1.0 1.1 1.4 5. Washington, D.C., C 494 617 760 1,158 SMSA E 493 639 789 1,146 6. Non-SMSA, MD C 3.4 5.7 8.6 18.2 E 3.6 6.0 9.1 18.1 7. Non-SMSA, VA C 3.1 3.6 4.2 5.8 E 3.2 3.8 4.4 5.7 8. Richmond, SMSA C 86 100 124 189 E 85 99 116 156 9. Non-SMSA, VA C 0.3 0.4 0.4 0.6 E 0.3 0.4 0.3 0.4 10. Newport News- C 36.8 42.3 50.0 67.5 Hampton SMSA E 33.6 38.9 43.9 57.4 11. Norfolk-Ports- C 79.7 92.4 109 144 mouth SMSA E 74.7 88.0 101 131 12. Non-SMSA, VA C 7.4 8.7 10.7 15.3 E 6.6 7.8 9.0 12.1 BAY AREA TOTAL C 1,039 1,237 1,487 2,159 E 997 1,196 1,410 1,923 presentation of the assumptions and methodology used in the analysis is included in Chapter 111. As explained in Chapter 111, the analysis was conducted specifically for the Chesapeake Bay Study by the Bureau of Domestic Commerce (BDC) U. S. Department. of Commerce. Projection Sets 1, 2, and 3 were based on the work of BDC using varying assumptions concerning future recycling. All three projection sets are presented here in order to compare the sensitivity of industrial water needs under the full range of assumptions. .Appendix 5 107 ASSUMPTIONS AND METHODOLOGY In the process of developing a forecast of future industrial water needs for the Chesapeake Bay Area, three separate projection sets were constructed. The projection sets varied only in the assumptions concerning future rates of recycling. Projection Set I was based on a series of assumptions related to the National goal of zero discharge of pollutants as set forth in P.L. 92-500. The methodology culminated in the attainment by each industry group of a "maximum theoretically possible" recycling rate by the year 2000. Projection Set 2 was derived assuming that current rates of recycling within each industry group would remain constant through the year 2020. Projection Set 3, which was selected as the baseline projections for future industrial water supply needs in Chapter 111, was based on a continuation of the 1975 to 1980 trend in improvement in recycling as derived by BDC in Projection Set 1. For purposes of discussion, the three projection sets numbered 1, 2, and 3, are termed "advanced", "constant", and "moderate", respectively, in reference to the degree of implementation of technology assumed in each case. A complete discussion of the assumptions and methodology associated with each of the three projection sets is included in Chapter 111. RESULTS Comparisons of water use in manufacturing for each of the three projection sets is shown in Table 5-39 for the entire Bay Area. Since the measure of production and the amount of water needed per unit production are the same in each projection set, the gross amount of water required and the resulting consumptive losses are also the same in each projection set. By varying the assumptions concerning future rates of recycling, differences are observed in "intake" and "discharge." Intakes are shown to vary by nearly 10 billion gallons per day in the year 2020 between the advanced technology case (Projection Set 1) and the constant technology case (Projection Set 2). Under assumptions implicit in the moderately advancing technology case (Projection Set 3), water intakes are shown to decline slowly through 1990 and .then grow to about 1,800 mgd by the year 2020. This is felt to be the most realistic projection set in terms of planning for Chesapeake Bay. If the water reuse and recycling technology associated with Projection Set I is indeed attained, water withdrawals in the Chesapeake Bay Area would be reduced by approximately I billion gallons per day in 2020. A plot of projected gross demand, consumption, and intake demands for each projection set are shown in Figure 5-8. Appendix 5 108 TABLE 5-39 WATER USE IN MANUFACTURING WITH VARIOUS ASSUMPTIONS ON FUTURE TECHNOLOGY (ingd) Parameter Projection Set 1970 1980 1990 2000 2020 Gross Use All cases 2,608 4,408 6,002 8,592 17,290 Intake 1 1,615 1,581 517 418 804 2 1,615 2,731 3,718 5,322 10,711 3 1,615 1,581 1,344 1,398 1,823 Consumption All cases 74 158 246 341 652 Discharge 1 1,541 1,424 270 76 151 2 1,541 2,573 3,472 4,981 10,058 3 1,541 1,424 1,098 1,057 1,171 A breakdown of the intake demands by subregion is presented in Table 5-40 for each projection set. Figures shown for the moderate technology case (Projection Set 3) were taken from Chapter Ill. These are compared with results assuming attainment of advanced technology and conditions of constant technology (Projection Sets I and 2, respectively). In the projection of industrial water use for the case of advanced technology (Projections Set 1), each major 2-digit industrial sector was investigated. Results of this analysis are presented in Table 5-41 and can be compared with results in Table 5-10 for the moderate technology case. All sectors show impressive recirculation capabilities-the highest being in the Petroleum sector in which 98.6 percent of the gross water use might be recirculated by 2000. This is equivalent to saying that a given unit of intake can be recycled or reused 69 times before being consumed or discharged (recycling rate = G / 1). Recycling rates of about 33 for Chemicals and 31 for Paper and Allied Products indicate these industries' ability to recycle water if the best technology is implemented. At present, the Paper industry possesses a recycling rate of 8.9, the best of all Chesapeake Bay major sectors. This means that 88.8 percent of all needs are met by recycled water. Food industries, which incorporate fair amounts of water into products, presently use a unit of water only 1.08 times, but, with estimates of advanced technology, this would grow to 6.99 by 2020. ADPendix 5 109 10,000 sox @ke Prolocdon S9t 3 co E Lu 1,000-- Lu oil 100 1980 1990 2000 2010 2020 YEAR FIGURE 5-8.- INDUSTRIAL WATER USE WITH VARIOUS LEVELS OF TECHNOLOGICAL ADVANCE Appendix 5- 110 TABLE 5-40 WATER INTAKES IN MANUFACTURING WITH VARYING TECHNOLOGY, BY SUBREGION, mgd Advanced Constant Moderate Gross Technology Technology Technology Subregion Year Demand (Proj. Set 1) (ProJ. Set 2) (Proj ._ Set 3) BAY 1970 2,607.9 1,615.5 1,615.5 1,615.5 AREA 1975 3,512.5 1,823.9 2,175.9 1,823.9 TOTAL 1980 4,408.2 1,581.4 2,730.7 1,581.4 1990 6,001.6 516.8 3,717.8 1,344.1 2000 8,591.5 417.6 5,322.1 1,397.8 2020 17,290.2 803.8 10,710.7 1,822.9 1 1970 1,226.1 990.7 990.7 990.7 1975 1,703.3 1,174.7 1,376.3 1,174.7 1980 2,179.2 1,034.2 1,760.8 1,034.2 1990 2,751.8 282.5 2,223.4 830.2 2000 3,608.4 217.0 2,915.6 793.3 2020 5,997.5 358.8 4,846.0 856.4 2 1970 35.5 34.8 34.8 34.8 1975 39.9 37.8 39.1 37.8 1980 44.5 34.6 43.6 34.6 1990 52.5 14.2 51.2 30.8 2000 71.6 11.7 70.2 33.8 2020 124.1 19.9 121.7 41.8 3 1970 2.6 2.3 2.3 2.3 1975 2.9 2.4 2.6 2.4 1980 3.3 2.0 3.0 2.0 1990 4.1 1.1 3.7 1.7 2000 5.4 0.9 4.8 1.7 2020 9.2 1.6 8.3 1.9 4 1970 82.7 65.6 65.6 65.6 1975 89.5 61.4 71.0 61.4 1980 86.4 43.5 68.5 43.5 1990 53.1 14.0 42.1 18.0 2000 81.1 12.8 64.3 20.6 2020 175.0 27.7 138.8 29.5 5 1970 5.4 4.7 4.7 4.7 1975 6.4 6.0 5.6 6.o 1980 8.0 6.6 7.0 6.6 1990 12.0 6.9 10.4 8.5 2000 18.6 8.2 16.2 11.3 2020 41.8 18.9 36.3 19.7 Appendix 5 TABLE 5-40 (continued) WATER INTAKES IN MANUFACTURING WITH VARYING TECHNOLOGY, BY SUBREGION, mgd Advanced Constant Moderate Gross Technology Technology Technology Subregion Year Demand (Proi. Set 1) (Proi. Set 2) (Proi. Set 3) 6 1970 0.8 0.8 0.8 0.8 1975 1.1 1.1 1.1 1.1 1980 1.3 1.3 1.3 1.3 1990 2.1 2.1 2.1 2.1 2000 3.5 3.5 3.5 3.5 2020 7.5 7.5 7.5 7.5 7 1970 32.9 27.4 27.4 27.4 1975 45.4 32.3 37.8 32.3 1980 57.9 28.4 48.2 28.4 1990 89.3 3.5 74.3 28.0 2000 141.1 4.5 117.4 32-.3 2020 331.4 10.6 275.7 49.4 8 1970 400.5 286.8 286.8 286.8 1975 573.6 326.5 410.7 326.5 1980 746.2 268.9 534.3 268.9 1990 1,168.9 55.7 836.9 250.9 2000 1,862.0 61.0 1,333.2 283.4 2020 4,458.7 144.4 3,192.4 429.9 9 1970 52.4 26.5 26.5 26.5 1975 66.6 26.5 33.7 26.5 1980 80.2 21.6 40.6 21.6 1990 115.4 10.8 58.4 19.6 2000 171.0 5.7 86.5 21.0 2020 366.2 12.3 185.3 29.0 10 1970 114.9 100.2 100.2 100.2 1975 149.7 79.1 130.5 79.1 1980 184.6 58.8 161.0 58.8 1990 255.4 41.2 222.7 46.9 2000 358.6 14.7 312.7 46.0 2020 720.7 29.1 628.5 57.9 11 1970 32.3 25.3 25.3 25.3 1975 41.6 21.0 32.6 21.0 1980 53.5 16.4 41.9 16.4 1990 73.3 13.4 57.4 13.0 2000 109.1 6.7 85.4 13.6 2020 236.7 14.7 185.3 18.5 12 1970 621.8 50.4 50.4 50.4 1975 792.5 55.1 64.2 55.1 1980 963.1 65.1 78.0 65.1 1990 1,424.0 71.4 115.3 94.4 2000 2,161.1 70.9 175.0 137.3 ADpenOix 5 2020 4,821.4 158.3 390.5 281.4 112 TABLE 5-41 WATER USE IN MANUFACTURING WITH ADVANCED TECHNOLOGY, BY SECTOR, CHESAPEAKE BAY AREA, mgd Gross Water 'Recycling Demand Intake Consumption Discharge Rate ALL MANUFACTURING 1970 2,607.9 1,615.5 74.2 1,541.3 1.63 1975 3,512.5 1,823.9 112.5 1,711.4 1.92 1980 4,408.2 1,581.4 157.5 1,423.9 2.71 1990 6,001.6 516.8 246.4 270.4 12.5 2000 8,591.5 417.6 341.3 76.3 23.8 2020 17,290.2 803.8 652.4 151.4 25.2 FOOD & KINDRED PRODUCTS (SIC 20) 1970 79.7 74.3 5.6 68.7 1.08 1975 95.4 81.3 6.1 75.2 1.19 1980 111.1 75.3 6.4 68.9 1.53 1990 146.0 38.9 6.3 32.6 4.86 2000 196.4 39.1 8.4 30.7 6.99 2020 343.9 68.6 14.8 53.8 6.99 PAPER & ALLIED PRODUCTS (SIC 26) 1970 644.8 72.8 7.6 65.2 8.91 1975 848.2 88.1 17.8 70.3 9.69 1980 1,051.6 100.9 25.2 75.7 10.41 1990 1,546.1 112.5 49.5 63.0 13.9 2000 2,334.9 76.5 74.6 1.9 31.3 2020 5,145.5 168.6 164.4 4.2 31.3 CHEMICALS (SIC 28) 1970 402.5 328.1 14.5 313.6 1.22 1975 560.1 382.6 19.6 363.0 1.46 1980 719.3 342.3 24.5 317.8 2.11 1990 1,131.5 42.3 33.9 8.4 29.5 2000 1,804.5 60.5 54.2 6.3 33.3 2020 4,319.3 144.8 129.7 15.1 33.3 Appendix 5 113 TABLE 5-41 (continued) WATER USE IN MANUFACTURING WITH ADVANCED TECHNOLOGY, BY SECTOR, CHESAPEAKE BAY AREA, mgd Gross Water Recycling Demand Intake Consumption Discharge Ratel PETROLEUM (SIC 29) 1970 81.6 76.3 0.7 75.6 1.07 1975 99.8 79.4 0.9 78.5 1.17 1980 105.3 63.3 1.2 62.1 1.66 1990 136.9 2.8 1.9 0.9 50.6 2000 178.9 2.5 2.5 0.03 69.0 2020 294.8 4.2 4.1 0.05 69.0 PRIMARY METALS (SIC 33) 1970 1.094.6 882.3 35.1 847.2 1.24 1975 1,423.4 965.5 54.1 911.4 1.47 1980 1,752.1 815.6 78.8 736.8 2.15 1990 2,203.2 191.3 130.0 61.3 11.5 2000 169.0 166.6 2.4 16.9 2020 -4,536.8 271.5 267.7 3.8 16.9 OTHER MANUFACTURING 1970 304.7 181.7 10.7 171.0 1.82 1975 490.6 227.0 14.0 213.0 2.18 1980 668.8 184.0 21.4 162.6 2.85 1990 837.9 129.0 24.8 104.2 9.72 2000 1,253.2 70.0 35.0 35.0 41.3 2020 2,649.9 146.1 71.7 74.4 41.3 lValue shown is for large water users only. Appendix 5 114 It should be reemphasized that this analysis assumes achievement of maximum theoretical technology in the manufacturing industries as the Nation moves towards the goal of zero discharge of pollutants. No connotation as to desirability or undesirability is implied. This information is presented to aid planners as a future decision-making tool, and is intended only as an indicator of the effect that might be expected due to pursual of water quality goals. Two other considerations are also worthy of note as regards future industrial water use in the Chesapeake Bay Area. First, as was stated in Chapter 11, industrial water use is concentrated in a relatively few large plants in particular types of industry. This suggests that the timing and achievement of water resources management goals in the Chesapeake Bay Region are extremely dependent upon the policies and actions of these existing large water-using plants, and upon the growth and expansion of similar industries. Second, while brackish water is presently utilized as a substitute for fresh water, the continuation of its use in similar proportions as the economy of the region grows may not occur. Essentially all brackish water withdrawals at present are for use as cooling water in heat exchange equipment which results in a heated waste water. If thermal pollution control for discharges into the bay and tributaries is required, it is probable that cooling towers and ponds will be utilized and that the cooling water will be recycled rather than discharged. Under those circumstances, the make-up water added-to the cooling system to replace water lost through evaporation and blowdown is likely to be fresh rather than brackish to prevent an unacceptable buildup of dissolved solids in the cooling water system. These factors make clear the need for periodic surveys and updates of industrial water use and location especially in the planning stages of future managerial actions that may be influenced by changed water use habits. In summary, the future amount of water that may be required to meet the needs of industry will depend on the degree of recycling practiced. Within the range of assumption used, water withdrawals could vary from approximately 800 to over 10,000 mgd by 2020. Under the assumptions of "moderate" technological advance, which are considered the most realistic for purposes of this report, withdrawal demands increase to a value of 1800 mgd by the year 2020. APDendix 5 115 CHAPTER V MEANS TO SATISFY THE NEEDS Chapter III included a presentation of the potential water supply deficits that can be expected under the assumed population and economic growth characteristics. This chapter includes a discussion of the alternative measures by which water shortage problems might be alleviated. Both developmental and institutional measures will be considered. Detailed alternatives investigation for specific water service areas, or type of use (industrial, agricultural, public, etc.), are beyond the scope of this study. Future studies and alternatives analysis will be required to arrive at site-specific costs and engineering designs to meet the needs identified in Chapter 111. DEVELOPMENTAL MEASURES Means to satisfy water supply needs can generally be categorized, as "developmental" or "institutional." Developmental means involve the classical engineering solutions for water supply shortages, such as surface water impoundment, development of ground water, or inter-basin diversion. Transmission and distribution mains, intake structures, and treatment plants are related system engineering developments needed to bring the supply from the source to the consumer. In Chapter 111, the deficits identified were based on the maximum demands for durations of 1, 7, and 30 days. This range of demands was developed to highlight the variations in deficit that occur under conditions of average flow and low flow, and to identify areas where water supply problems exist or are emerging. Development of the full range of demands under varying low-flow conditions is also required in order to evaluate the effectiveness of the various alternative means of meeting water supply deficits. It should also be noted that strearnflows shown as the available supply in Chapter III are those low-flows that may be expected only once in 50 years, and, as such, represent relatively rare occurrences. Use of a less severe low- flow, such as 25-year or 10-year, would require tradeoffs between the threat- of-shortage, and the reduced expense. In the planning stage of an effort to alleviate an identified water supply shortage, the question arises as to what type source to develop-should surface flows, impoundments, wells, or some more unusual source be used, such as desalination or interbasin diversion? Would regionalization of a group of smaller systems under jurisdiction of an area-wide authority provide a more economical and equitable supply for all? Perhaps a small water system would ADpendix 5 117 find it more economical to purchase water from a nearby large system rather than develop its own incremental supply. All these factors, plus other problems, and considerations, such as costs, financing, dependabilty, and quality, must be considered when planning a water supply system. SURFACE SUPPLIES Surface water presently meets the majority of the municipal and industrial water supply demands in the Chesapeake Bay Area, particularly in areas requiring large supplies. Groundwater, while more evenly distributed around the Bay Area and less susceptible to seasonal fluctuation, is generally more difficult to retrieve in large quantities. River flow is fed by runoff and groundwater discharge from its entire basin, sometimes, as in the case of the Susquehanna and Potomac Rivers, covering thousands of square miles. In addition to the quantity of water available, quality considerations are also very important in the development of surface supplies. Generally speaking, surface sources are much more susceptible to pollutants. Municipal and industrial discharges, pesticides and fertilizers from agricultural lands and even natural properties, such as hardness and sediment are just a few of the pollutants that can reduce the utility of the strearnflow for downstream users. Impoundments A major problem in the use of surface water supplies is the seasonal variation in flow. Peak demands usually coincide with the season of lowest flow in the streams. Dam construction is a means by which reduction of variability can be attained, and the dependable flow or safe yield of a watershed increased. Water is stored in the reservoir during periods of excess flow for use during seasonal periods of low flow and high domestic demands. Over the long term, however, average stream flow must exceed demand by a substantial margin in order to maintain a minimum conservation pool, allow for evapotranspiration, and provide a minimal base-flow below the dam. For a particular drainage basin, the amount of storage needed to effect a given increase in dependable stream flow is dependent on several variables, including the chronological sequence of flows and the long term variation in stream flow. Hydrographs of the longest and driest period known (or predicted) can be used to construct a mass diagram of aggregated flow with time. This may be used in conjunction with a mass curve of demand to determine the volume of reservoir storage needed to alleviate dry-season deficitS26. Appendix 5 The capacity of a particular reservoir site must also be investigated with respect to the height of dam and resulting water surface area. Curves can be constructed showing the relation between depth and surface area, and between depth and volume storage, known respectively as "area" and "capacity" curves. A typical example is shown in Figure 5-9 for Triadelphia Reservoir on the Patuxent River, Maryland. Although detailed hydrologic investigations are needed for specific site investigation, generalized relationships can be derived for areas with similar topography, geologic makeup, and climate. For example, using data derived for possible impoundment sites in the Potomac River Basin Study27, a relationship can be derived between storage volume and increased dependable yield, as shown in Figure 5-1028. The sample includes reservoir sites that would provide between 40,000 and 500,000 acre-feet of storage and that would create lakes to be managed as multi-purpose facilities. Thus, assuming the curve is typical of the upland Piedmont Portions of the Chesapeake Bay Area, provision of about 200,000 acre-feet of storage might be expected to increase dependable strearnflow by 175 mgd. Management of supplies strictly for water supply purposes, however, could increase the safe-yield substantially. The cost of a reservoir development is dependent on many variables, often not in the least consistent from project to project. Cost variables to be considered include dam construction, operation, and maintenance; land acquisition; building relocation and demolition; clearing of reservoir site; and highway and railroad relocation. Local site characteristics peculiar to each project will govern overall costs. The geology of an area, for example, will affect both the type and configuration of the dam. Upstream land use will affect storage needed for sedimentation. In addition, local topography will influence the length and height of dam needed to effect a given storage volume. Presence of valuable residences, farms, railroads, and other developments can increase land acquisition and relocation costs significantly, sometimes to more than 75 percent of total. Typically, the projects are designed to serve as far as 50 years into the future. Natural Stream Flow Free-flowing surface waters are another source of supply available to meet expanding needs. The Susquehanna, Potomac, Rappahannock, James, and Appomattox Rivers presently serve as major sources of water supply for the Annendix 5 119 ridges, and fairly steep stream slopes. It is well drained by the many streams and rivers which empty into the Bay30. Use of natural stream flows as water supply sources (without impoundment) depends on the minimum predicted flow exceedng the maximum demand during the driest season. Otherwise, off-stream storage facilities or dams will be needed to store water for use during deficit periods, or for release to supplement downstream flows. Based on stream flow records, estimates can be made of the frequency of occurrence of various low-flows. Although low-flow analysis can be estimated for streams without flow records, by synthesizing data from nearby streams, a minimum of 10 years flow record is recommended for analysis of streams with gaging stations. Attachment B details the stream flow of streams in the Chesapeake Bay Area (greater than 5 cfs average discharge) for a 7-day duration low-flow to be expected once in 10, 25, and 50 years. Tradeoffs are encountered in the development of water supply sources between the threat of shortage and the added expense of developing a more reliable source. The relationship between the low-flow recurrence interval and the probability of its occurrence is shown in Table 5-42. For example, a system designed around a 20-year low-flow has a 5 percent probability of shortage in any given year. The water facilities designer must decide upon the acceptable level of risk to the community. Services for lawn watering and swimming pools, and certain commercial, industrial, and public uses can often be curtailed temporarily without undue hardship or risk to the public health, or community well-being. TABLE 5-42 PROBABILITY OF LOW-FLOW OCCURRENCE Recurrence Interval, Years 50 25 20 10 5 2 Probability of Occurrence in any particular year, Percent 2 4 51 10 20 50 GROUNDWATER Groundwater is another water supply source which can be developed to meet needs in deficit areas. Massive amounts of water are stored in the pore spaces of the soils and rock formations of the Bay Area. However, the amount recoverable is governed by economics, and the geo-hyrologic character of the area. Figure 5-11 illustrates the groundwater situation, as it might typically relate to topography in the Piedmont region of the Study Area. Except for "perched" water tables, in which the water is retained, subsurface flow will ADDendix 5 122 occur from areas of higher head to eventually discharge into streams, lakes, bay, or oceans. Water withdrawals from wells will cause a lowering of the water table in a three dimensional cone of depression around the well. Groundwater supplies generally serve their most valuable function in areas with small scale, evenly dispersed demands, such as those for the rural domestic population; agriculture; and small towns, cities, and other facilities. Establishments requiring concentrated large-scale water supply developments have invariably located in Western Shore areas where there is a greater potential for development of surface waters. Several items must be considered before _proceeding with development of a groundwater supply. Short of a complete scientific investigation including test wells, analysis should be mad 'e of the bore-hole logs of wells previously drilled in the vicinity, and of other groundwater studies and reports to gain perspective of the geohydrologic profile of the substrata. Estimates are needed of the thickness of the various available aquifers, their depth, porosity, permeability, and quality characteristics, so that alternatives can be evaluated along with costs comparison. Effects of the proposed withdrawals with respect to water table stability and salt water intrusion, should also be considered as should the effects of other pumping patterns in the vicinity. Unfortunately, ,.tobte. Vol - V@Ofl - -Und --- 410 06 ro tuo - tj OC - ot Oug we// -Z-- 10 Driven - - - - -- well Source: Babbitt, Doland, and Cleasby; Water Supply En&ineerins_, McGraw Hill Co., 1962. FIGURE 5-11: RELATIONSHIP BETWEEN GROUND AND SURFACE WATERS Appendix 5 123 quantitative assessment of these factors is often difficult due to the lack of necessary data, especially for the deeper aquifers. However, complete neglect of these considerations can hasten the inadequacy or pollution of the source, or cause the supply to become uneconomical as the water has to be lifted from greater and greater depths3l. A detailed assessment of the groundwater system in the Chesapeake Bay Area, including yields, aquifers characterizations, and quality considerations, is presented in Appendix B, Volume 1, of the Existing Conditions, Report of the Chesapeake Bay Study. Some treatment of considerations in groundwater development will be made here, however, including a short discussion of typical costs. Types of Wells Wells can generally be classified by type of construction-whether dug or drilled. Dug wells most commonly occur in rural areas where they are used by the rural domestic population or to meet agricultural needs. They are often excavated by hand with a well lining, casing, or curbing of porous masonry at the aquifer level. Above the aquifer, a watertight masonry liner should be used along with a watertight cover to prevent surface water or other undesirable air- or water-borne debris from entering. Wells excavated in rock are often left unlined. Drilled wells are generally used to retrieve groundwater supplies from the deeper aquifers. The wells are sunk either by percussion or rotary drilling techniques. They should be cemented above the producing aquifer between the outside of the hole and the inner casing to eliminate the downward flow of surface water contaminants, and to prevent erosion of soil outside the casing32. Deep well pumps are generally needed where the suction lift required exceeds 25 feet. Various types of screens and casings are used depending on the geological profile of the aquifer being tapped. Coastal Plain Groundwater The Coastal Plain, lying east of the Fall Line (Figure 5-2) is composed of alternating layers of sand, gravel, clay, mud, and silt, dipping southeasterly at an average of about 80 feet per mile in Maryland and 25 feet per mile in south- ern Virginia. The permeable sand and gravel layers are some of the most productive aquifers in the United States. Yields as high as 4,000 gpm have been achieved from an ancient gravel-filled channel near Salisbury, Maryland.33. Anpendix 5 124 More normally, yields range between 300 and 1,000 gpm, but decrease to near zero at the featheredge of sediments near the Fall Line. Generally, yields of 100 gpin can be developed from the water table aquifier (Quaternary deposits) of Eastern Shore. On the Western Shore portion of the Coastal Plain, a maximum yield of 2,000 gpm has been achieved at Bowie, Maryland34. Groundwater in the Piedmont Typically, only small amounts of water are recoverable from the rock formations of the Piedmont Province portion of the Study Area. Thin layers of weathered material provide for storage and transportation of groundwater and serve as recharge channels to deeper fracture and fault systems. Overlying clays in most areas reduce recharge, however, and yields often respond markedly with varying precipitation. Well yields vary generally between 10 and 50 gpm, but dry well holes are not unknown15. Dependable Yield Although tremendous volumes of water exist in the rocks and sediments of the Chesapeake Bay Area, only a relatively small portion is perennially available for use. The amount recoverable is dependent on several factors including the porosity, permeability, and transmissivity of the aquifer, and, ultimately, on the rate of inflow to the aquifers from stream infiltration, rainfall percolation, and adjacent water-bearing formations. In turn, there are discharges to streams, the Bay, and/or ocean, and losses from the groundwater reservoirs to evapotranspiration. If allowance is made for discharges to the Bay and the Atlantic Ocean and losses to evapotranspiration, estimates can be made of the "base flow" of streams, or the contribution of groundwater to strearnflow. This method was used by the United States Geological Survey (USGS) to derive the developable resource of the Eastern Shore of the Study Area (Delmarva Peninsula)36. Using these results and the data from other reports and studies, the ultimate developable groundwater resource of the Chesapeake Bay Area was determined, as detailed in Attachment 5-C. These figures should be considered only as gross estimates, however, due to the limited data available and the broad generalizations used. 4 Sufficient groundwater for local needs can be attained but excessive pumpage can reduce the water table to dangerous levels. Lowering of the pressure in the freshwater zone allows the gradual penetration of saltwater into the aquifer from ocean, bay, tidal river, or canal. Withdrawals of about 3.5 mgd from the Piney Point artesian aquifer at Cambridge, Maryland, have caused water levels to decline by as much as 25 feet at a point 12 miles from the well site37. ADnendix 5 125 Likewise, heavy use of the Potomac aquifer at Franklin, Virginia, has lowered the water table to 150 feet below sea level since the early 1900'S38. In contrast, however, withdrawals of 10 mgd at Salisbury, Maryland, have not significantly affected the water table due to the particular conditions there. In general, however, it can be expected that concentrated groundwater withdrawals in excess of 3500 gpm will cause some eventual problems due to excessive drawdown39. Groundwater Retrieval Costs Several considerations must be made before costs of groundwater development can be determined40: a. The'probable yield of wells in the various aquifers. b. Drilling costs and equipment. c. Spatial distribution of wells. d. Costs of interconnecting pipelines in multiple well development. e. Amortization of capital costs and addition of annual maintenance and pumping costs ($/ 1000 gallons). As part of the North Atlantic Regional Water Resource Study costs were estimated for development of groundwater in various geologic settings. Although variations will occur depending on local conditions and may other factors, it is noted that costs per 1,000 gallons will vary by only 2 mills for a $2,000 variance in the capital costs of the well4l. Table 543 details estimated costs of groundwater development for a range of well yields in both the Coastal Plain and Piedmont consolidated rocks. Costs shown include capital costs, easements, operation, and maintenance. TABLE 5-43 REPRESENTATIVE GROUNDWATER RETRIEVAL COSTS, 1970 ($/1,000 gallons) Yield per Well (Gallons per Minute) Coastal Plain 150 350 700 1400 1 well $0.035 $0.025 $0.021 $0.020 10 wells $0.045 $0.036 $0.029 $0.024 20 wells $0.049 $0.041 $0.032 $0.027 ApDendi x 5 1-26 It should be noted that cost per 1,000 gallons at the wellhead from a single well, and that for multiple wells, is the same-the higher costs shown in the above table are for the interconnecting pipe. For additional information on well development costs, see the NAR Study, Appendix D, "Geology and Groundwater." DESALTING AS AN ALTERNATIVE SOURCE Conversion of brackish water to fresh water is a technique which can be used in areas which have depleted their conventional sources of supply. Given a supply of sea water or other brackish source, freshwater can be derived by various methods of heating with condensation of the resulting steam. Other methods involving membrane processes and freezing processes have also been used. The choice of a process for application to a particular source of supply is generally based on the least cost to achieve the desired supply. Some of the factors to be considered include: a. Salt concentration and composition of available feedwater. b. Quality needed in product water. c Waste brine disposal difficulties. d. Type and cost of energy sources available. e. Size of plant required. f. Commercial status of the process. Distillation Various distillation processes have been used extensively around the world for reclaiming seawater or the more concentrated brines. These are the vertical tube evaporator (VTE), the multistage flash process (MSF), and the vapor compression processs (VC). The MSF distillation process involves heating the seawater and passing it through progressively lower pressures, causing at each stage some of the water to boil, or "flash," into steam, which then condenses as freshwater. Appendix 5 127 The VTE process drops the saltwater through long metal tubes being heated by steam in large vertical chambers. Some of the saltwater blows off as steam while some of the steam surrounding the cooler tubes condenses as freshwater. The process is repeated through several stages at progressively lower pressures, to obtain higher efficiency in the use of heat energy. The VC process involves, in its simplest form, the boiling of brine inside vertical tubes. The steam produced is pressurized and heated with a mechnical compressor and then condensed on the outside of the same tubes. A combined MSF-VC-VTE process has also been proposed to improve efficiency. The VC process has been widely developed for use on vessels on the high seas and at other places with requirements of between 0.02 and 1.0 mgd. Distillation plants require a source of steam to heat the water and are, for this reason, often most economically operated in conjunction with power generation facilities. Otherwise, steam can be supplied by boilers or vapor compressors. To date, the MSF process has been recognized as the most economical distillation process but development of more efficient heat exchange piping may make VTE more attractive in the future. These processes typically have a waste brine of about 7 to 10 percent salt42. Membrane Processes Membrane processes may have wide application in treating brackish waters of less salinity than seawater - generally 10 ppt is taken as an upper limit. One type of membrane process is electrodialysis. It consists of stacks of membranes that are alternatively permeable to positive and negatively charged ions, but impermeable to ions of the opposite charge. Placed between an anode and cathode, alternate passages between the membranes produce desalinized water. Plants as large as 1.2 mgd have been in operation43. Reverse osmosis is another type of membrane process. Membranes are used that are selective of the components in solution that can pass through. The saltwater is first filtered and then raised to a pressure of between 600 and 1,000 psi. The product portion of the water permeates the membranes. Only plants as large as 0. 15 mgd have been developed. Freezing Process This process involves freezing the saline solution. Freshwater ice crystals are- formed, the salts concentrated in the remaining brine solution. Freshwater is then obtained by washing the ice and melting. One of the more successful Appendix 5 128 freeze processes developed to date involves freezing by vacuum evaporation. The resulting water vapor is then compressed and condensed on the ice crystals in a separate compartment. For outputs of 0.5 mgd, 30 KWH electrical energy are needed per 1,000 gallons product, making this one of the more energy consumptive desalting techniques. Costs The costs of desalted water will vary considerably depending on plant location, size, type of desalting process, financing, costs of energy, and other variables. Current commercial plants of between I and 3 mgd capacity, produce water in the general range of one dollar per 1,000 gallons. This is very expensive considering that surface or groundwater developments rarely exceed $0. 10 per thousand-gallons, even for interbasin diversions over long distances. Studies have indicated, however, that large dual purpose desalting plants may produce at a rate of 20 to 40 cents per 1,00.0 gallons by the 1980'S44. Collection and water conveyance costs could add another 5 to 10 cents per 1,000 gallons. INSTITUTIONAL MEASURES Developmental means will probably continue to be used in most instances to meet expected water demands; however, consideration should also be given in the planning of water supply developments to institutional arrangements (changes in law, custom, or practice) and policy changes which can sometimes increase efficiency of use of existing supplies or otherwise effect a dampening of demand. Examples include pricing and metering to encourage thrift, implementation of plumbing codes to encourage water-saving appliances, and restrictions on use during droughts. Advancing technology and a change in public acceptance could also lead to the reuse of wastewater for municipal purposes in areas depleted of the more traditional sources. Homeowners, commercial establishments, and industries alike will curtail excess usage, to varying degrees, as water supplies increase in cost. One study has shown that a doubling of price, for a representative 21 metered and public- sewered cities, would result in a 10 percent decrease in household use and a decline of 53 percent in summer sprinkling use, as shown in Figure 5-1245. In addition, a survey of many studies has shown that reduction in water use due to installation of meters has varied from 25 to 75 percent46. Thus, water use can be expected to diminish if water costs are in some relation to volume con- sumed, especially for the less essential and more consumptive uses such as lawn sprinkling. It has beer. found that sprinkling of lawns is one of the uses most responsive to metering and that in areas with flat-rate pricing (constant price Ab rate) the tendency is for over-irrigation of lawnS47. Water use restrictions are another method of alleviating water supply shortages in a community. As opposed to increasing the volume of supply, this ADY)endix 5 129 Source: Hanks, S.H. (45) Boo W 700 60o- J W Boo.- 0 Z '3 @ 400- W Z 2- J 2 A 300 Z UJ SUMMER TOTAL cc 200 UJ household IL LU 100 0 20 40 so so 100 120 140 WATER COST (0/1,000 GAL.) FIGURE 5-12. EFFECT OF PRICE ON DOMESTIC WA TER USE method involves dealing directly with the control of demand so that it can be reduced to more closely approximate the available supply during periods of drought. Use restrictions are most effective when they are applied to uses such as lawn watering, car washing, street cleaning, and non-critical commercial and industrial uses in such a way that major inconvenience and/ or economic damage is not suffered by the community. Also, water demands will tend to respond to unit price increases that can be implemented temporarily on those uses that exceed a specified limiting amount. Another demand-controlling measure is to decline requests for new or additional service from both inside and outside the present system. Similar to sewer moratoria, this type of measure can be used to guide and/or control a community's growth. It should be noted, however, that this type of measure may simply result in the demand and perhaps a problem being shifted to another location within the same region. Demands for water in industrial processes are another area in which there is potential for water saving. A major portion of this report has addressed the savings that may occur in industrial water use due to the adoption of new process technology and recycling practices. Further advances in technology, above the levels shown, should be encouraged in order to maximize the supply of water available for the many needs of society. ADDenOix 5 130 CHAPTER VI REQUIRED FUTURE STUDIES The preceding chapters of this appendix include an identification of future water supply requirements and the expected magnitude and time frame of future deficits. In a similar manner, the demands and deficits for other resource categories, such as those for recreation, power, waterborne commerce, and fish and wildlife, are developed and presented in other appendices of this report. Additional studies are required to integrate the needs projected for all resource categories, identify emerging or expected problems and conflicts between Bay users, and develop a comprehensive plan for the overall management of the Bay's resources. This overall plan should be developed and formulated in coordination with Federal, State, and local agencies and the public, with a view toward using the resources of Chesapeake Bay to provide the greatest benefits to the greatest number of people while maintaining the beauty and dignity of the Bay. With specific regard to water supply, studies and research are required to better define both the expected future water demands and the available supply. These studies are particularly critical in some of the highly urbanized areas such as Washington D.C. where increased growth and large water supply deficits are expected. Studies of the applicability and cost of various alternative means of providing additional supply should also be undertaken, and be given especially high priority in critical areas such as Southeastern, Virginia, and Washington, D.C. In addition to the more conventional uses of surface and groundwater, consideration should be given to such measures as desalinization, water reuse, and the use of brackish waters. Studies to determine the impacts in the Bay Region of metering and pricing would also be extremely valuable in evaluating these measures as demand controlling alternatives. Similarly, future increases in the price of water would warrant investigation as to the possible effects on regional site locations and water use habits of industrial and commercial establishments. Additional studies are also required to ascertain the most safe and cost effective means of treating waters for human consumption. Better methods must also be developed for monitoring the quality of treated waters and the ir impact of the wastes from water treatment facilities on the environment. Additional investigation is needed to fully assess the groundwater resources of the Region. Except in some areas where deep test wells have been monitored, knowledge of the groundwater resources is limited. An extensive exploration program would enable better mapping of aquifer composition, depth, and thickness and estimates of ultimate developable yields. Apnendix 5 131 As indicated previously, emerging or expected problems and conflicts between Bay users must be identified. One of the most significant Bay conflicts related to water supply is the impact on the fish and wildlife resources of reduced freshwater inflows into the Bay. These reductions in freshwater inflows are the results of increasing consumptive losses and interbasin diversions associated with increased demands for municipal, industrial, and agricultural water. Considerable study is required to better define the expected changes in salinity patterns that will result from varying decreases in freshwater inflows and the impact that these salinity changes will have on the biota of the Bay. The effects of reduced freshwater inflows on wastewater dispersion and the time distribution of nutrients must also be explored. The Chesapeake Bay Hydraulic Model has the potential to provide some of the physical data that are necessary to make many of the above evaluations. Since varying freshwater inflows can be easily simultated in the model, salinity patterns and flushing characteristics can be developed for any freshwater inflow condition desired. In this manner, the physical impacts of alternative structural or managerial actions can be provided to the appropriate scientists for further evaluation of the environmental impacts. Two of the initial tests planned for the hydraulic model are related to defining the impacts of changing freshwater inflows to the Bay. The objective of the Chesapeake Bay low freshwater inflow test is to determine the response of the Bay system to depressed freshwater inflows due to both droughts and increased consumptive losses. Emphasis will be placed on developing time histories of salinity concentrations for specific low flow conditions. The time required for the system to return to a state of dynamic normalcy following periods of depressed flow will also be determined. The second test will be a combined Potomac River Estuary water supply and wastewater disposal test. The objectives of this test are to define the salinity regime and wastewater dispersion patterns in the Upper Potomac Estuary under several freshwater inflow conditions and to determine the impact on both salinities and wastewater dispersion of pumping water out of the estuary at Washington, D.C. A more detailed discussion of the above tests and the capabilities of the hydraulic model may be found in Appendix 16: Hydraulic Model Testing. Appendix 5 132 FOOTNOTES 1. Daniel J. Boorstin, The Americans - The Democratic Experience (New York: Random House, Inc., 1973). 2. City of Baltimore, Department of Public Works, Bureau of Engineering, Comprehensive Water and Wastewater Plan (Baltimore, Maryland: Office of the Mayor, as revised, 1970). 3. Nelson, M. Blake, Waterfor the Cities (Syracuse: Syracuse University Press, 1956). 4. Washington Aqueduct Division, U.S. Army Engineer District, Baltimore, An Historical Summary of the Work of the Corps oflEngineers in Washington, D. C. and Vicinity, 1852-1952 (Washington, D. C@, .1952). 5. Fairfax County Water Authority,Annual Report (Annandale, Virginia, 1973). 6. Allen V. Kneese and Blair T. Bower, Managing Water Quality: Economics, Technology, Institutions (Baltimore: Johns Hopkins Press for Resources for the Future, 1968). 7. Edward A. Ackerman and George 0. G. 1-8f, Technology in American Water Development (Baltimore: Johns Hopkins Press for Resources for the Future, 1959). 8. The percent that recycled water represents of gross use is G-I/G. Another measure of water use efficiency is the "recycling rate,"or G/l. 9. David F. Bramhall and Edwin S. Mills, Consultants, The Maryland Water Supply and Demand Study, Part 11, Vol. I (Baltimore, Maryland State Planning Department, 1965). 10. U.S. Bureau of the Census, Census of Manufacturers, 1972, Vol. 1: Summary and Subject Statistics (Washington D.C., U.S. Government Printing Office, 1975). 11. Bramhall and Mills, The Maryland Water Supply Study. 12. Virginia, State Water Control Board, Rappahannock River Basin Water Quality Plan, Phase I Addendum (Richmond, 1972). 13. Virginia, SWCB, York River Basin Water Quality Plan, Phase I Addendum (Richmond, 1972). 14. Virginia, SWCB, Lower James River Basin Comprehensive Water Resources Study, Vol. VII-4, Part B, Groundwater Hydrology, by Richard Heil, Engineering Science, Inc., 1972. 15. U.S. Department of the Interior, Federal Water Pollution Control Administration, "Water Supply and Water Pollution Control," Ohio River Basin Comprehensive Survey, Vol. 5, Appendix D (Cincinnati: U.S. Army Engineer Division, Ohio River, 1967). 16. Virginia, SWCB, Lower James River Study: Groundwater Hydrology, 1972. 17. Harold E. Babbitt, James J. Doland, and John L. Cleasby, Water Supply Engineering (6th ed.; New York: McGraw Hill Book Co., Inc., 1962). 19. Gordon M. Fair, and John C. Geyer, Elements of Water Supply and Wastewater Disposal (New York: John Wiley & Sons, Inc., 1958). 19. U.S. Department of Commerce, Bureau of Economic Analysis, and U.S. Department of Agriculture, Economic Research Service, OBERS Projections, Vol. I (Washington, D.C.: Water Resources Council, 1974). 20. Ackerman and L&, Technology in American Water Development, p. 419. 21. Jbid., p. 433. Apnepdix 5 133 22. Ibid., p. 422. 23. Ibid. 24. Ibid., p. 425. 25. Fair and Geyer, Elements of Water Supp@y, 1958. 26. Babbitt, Doland, and Cleasby, Water Supply Engineering, 1962. 27. U.S. Department of the Army, Corps of Engineers, North Atlantic Division, Baltimore District, Potomac River Basin Report, Vol. I (Baltimore, 1963). 28. The relationship for 20 reservoirs in the Potomac River Basin between "increase in dependable flow," x, and "required storage," y, fits closely the curve log y = 1.7382 + 0.003176x, as shown in Figure 5-9. 29. Patrick N. Walker, Flow Characteristics of Maryland Streams, Report of Investigations No. 16 (Baltimore, Maryland Geological Survey, 1971). 30. Ibid. 31. Fair and Geyer, Elements of Water Supply, 1958. 32. Ibid 33. U.S. Department of the Army, Corps of Engineers, Baltimore District, Chesapeake Bay Existing Conditions Report, Appendix B (Baltimore: 1973). 34. A id. 35. Virginia, SWCB, Lower James River Study: Groundwater Hydrology, 1972. 36. U.S. Department of the Interior, Geological Survey, Water Resources ofthe Delmarava Peninsula, by E.M. Cushing, I.H. Kantrowitz, and K.R. Taylor, Professional Paper No. 822 (Washington, D.C: Government Printing Office, 1973). 37. Ibid. 38. Virginia, SWCB, Lower James River Study: Groundwater Hydrology, 1972. 39. U.S. Department of the Interior, Water Resources of the Delmarva Peninsula. 40. U.S. Department of the Interior, Geological Survey, "Geology and Ground Water," North Atlantic Regional Water Resources Study, Appendix D, (U.S. Army Engineer Division, North Atlantic, 1972). 41. Ibid. 42. U.S. Department of the Army, Corps of Engineers, North Atlantic Division, "Water Supply," North Atlantic Regional Water Resources Study, Appendix R, (1972). 43. Ibid. 44. Ibid. 45. Steve H. Hanke, Forecasting Urban Water Demands, unpublished lecture (Department of Environ- mental Engineering, Johns Hopkins Unviersity, Baltimore, n.d.). 46. M.H. Chiogioji and E.N. Chiogioji, Evaluation of the Use of Pricing as a Toolfor Conserving Water, Report to the Department of Environmental Services, Washington, D.C. (Washington, D.C.: Water Resources Research Center, Washington Technical Institute, 1973). 47. Hanke, Forecasting Water Demands. Appendix 5 134 48. U.S. Geological Survey, Water From the Coastal Plain Aquifers in the Washington, D.C., Metropolitan Area, Geological Survey Circular 697, 1974. 49. NAR Study, Appendix D: Geology and Groundwater, 1972, p. D-107. 50. Dallaire, Gene, "Will Industry Meet Water Quality RequirementsT', Civil Engineering, Dec., 1975. 51. National Water Commission, Water Policiesfor the Future, Final Report to the President and the Congress (Washington, D.C.: Government Printing Office, 1973). Appendix 5 135 BIBLIOGRAPHY Ackerman, Edward A., and Lbf, George O.G., Technology in American Water Development. Baltimore: Johns Hopkins University Press for Resource for the Future, 1959. Babbitt, Harold E., and Doland, James J., Water Supply Engineering. 6th ed. New York: McGraw Hill Book Co., 1962. Baltimore Regional Planning Council. Planfor Regional Water Supply to the Year 2020. Hazen and Sawyer, Consulting Engineers, 1969. District of Columbia, Department of Environmental Services. Evaluation of the Use of Pricing as a Toolfor Conserving Water, by M.H. Chiogioji and E.N. Chiogioji. Water Resources Research Center, Report No. 2, 1973. Fair, G.M., and Geyer, J.C. Elements of Water Supply and Wastewater Disposal. New York: John Wiley & Sons, Inc., 1968. Knesse, Allen V., and Bower, Blair T., Managing Water Quality: Economics, Technology, and Institutions. Baltimore: Johns Hopkins Press, 1968. McGauhey, P.H. Engineering Management of Water Quality. New York: McGraw-Hill Book Co., 1968. Maryland Geological Survey, in cooperation with the U.S. Geo!(-,gical Survey Flow Characteristics of Maryland Streams, by Patrick N. Walker. Report of Investigation No. 16, 1971. Maryland State Planning Department. Maryland Water Supply and Demand Study: Part I, by Bramhall and Mills, Consultants, and Part 1I. by Geological Survey, U.S. Department of the Interior, 1965. North Atlantic Regional Water Resources Study Coordinating Com- mittee. North Atlantic Regional Water Resources Study, Main Report and 22 appendices, 1972. Southeastern Virginia Planning District Commission. Regional Water Plan- Supply and Transmission, 1972. U. S. Congress. House. Potomac River Basin Report. H. Doc. 343,91st Cong., 2d Sess. Washington, D.C., G.P.O., 1970. Appendix 5 137 U.S. Department of the Army, Corps of Engineers, Baltimore District. North- eastern United States Water Supply Study: Preliminary Report for the South Central Pennsylvania, Baltimore, and Mason-Dixon Areas, 1970. U.S. Department of the Army, Corps of Engineers, North Atlantic Division. Northeastern United States Water Supply Study: Preliminary Study of Long-Range Water Supply Problems of Selected Urban Metropolitan Areas, by Anders on-Nich ols & Co., Inc., 1973. U.S. Department of the Interior, Geological Survey, Water Resources of the Delmarva Peninsula, by E.M. Cushing, I. H. Kantrowitz, and K.R. Taylor. Professional Paper 822. Washington, D.C.: G.P.O. 1973. U.S. National Water Commission. Water Policies for the Future. Final Report to the President and the Congress. Washington, D.C.: G. P.O. 1973. Virginia State Water Control Board. Potomac- Shenandoah River Basin Comprehensive Water Resources Plan. 1968-. _. Rappahannock River Basin Comprehensive Water Resources Plan. 1970- . York River Basin Comprehensive Water Resources Plan. 1970 - . Small Coastal River Basins and Chesapeake Bay: Comprehensive Water Resources Plan. 1972 _. Lower James River Basin Comprehensive Water Quality Manage- ment Study, prepared in part by Engineering - Science, Inc., 1972-74. Washington, D.C., Metropolitan Council of Governments. Water and Sewerage Plan and Program 1971-72. Washington, D.C., 1971. z Al ADDendix 5 138 GLOSSARY acre-foot - the volume of water required to cover I acre to a depth of I foot, equivalent to 43,560 cubic feet. aquifer - a saturated underground geologic formation of sand, gravel, or other porous material, capable of transmitting water to wells or springs. consumption - the amount of water lost between point of intake and discharge, by incorporation into products, evaporation, etc. discharge - the rate of flow of a stream, or of ground water to a well; also rate of wastewater flow from treat- ment plant or conduit. ecology - the interrelationship between living things, each other, and their environment. evapotranspirtation - combined loss of water to the atmosphere by evaporation from water surfaces and plant transpiration. GPO - Gross product originating - the portion of the Gross National Product originating in each sector of the National economy. groundwater - water occurring beneath the ground in the saturated pore spaces of the underlying geologic formations. instrearn uses - uses for streamflows not requiring withdrawal, such as recreation, fish and wildlife, and navigation. interbasin - physical transfer of water from one river basin to diversion another. precipition - any form of rain or snow falling to the earth's A surface. Appendix 5 139 reservoir - a pond, lake, aquifer, or basin, either natural or manmade, in which water is stored and/or regulated. residual - the sum of those persons not served by any population central water supply facility; all those persons supplying their own water by well or other means. riparian - unwritten law historically recognized in the doctrine Eastern States guaranteeing strearnflows be,un- diminished in quantity or quality due to un- reasonable upstream uses. runoff - the part of precipitation on a drainage basin appearing as strearnflow. S.I.C. - Standard Industrial Classification, as defined for each type of economic activity by the Office of Management and Budget. SMSA - Standard Metropolitan Statistical Area - generally, a designation of the U.S. Bureau of Census, for cities of 50,000 population, or more, and the socially and economically contiguous counties. WSA - Water Service Area - designation for cities or town in the Chesapeake Bay Study Area of 2,500 population, or more, being served by a central water supply agency or authority. water table - the upper surface of saturation of an under- ground water body. withdrawal - the removal of water from a natural watercourse or other source for use by industry, the cities, agriculture, or other purpose - also "intake." yield, dependable refers to quantity of water available for use from or "safe" natural strearnflow, or reservoir development, with a shortage occurring only once in "n" years. Dependability is relative to storage provided and drought probability. Apnendix 5 16,0 yield, ultimate for groundwater, refers to sustained perennial developable amount of water that can be withdrawn- amount cannot exceed recharge of the aquifers. Appendix 5 1 ILI T-V " , s XTPuaduy CD Of 10 co -4 cp@ @m 11 CA ro :9 C- 3: M C2 W CD '.0- W- EA W -0 -D M 0 C3 C2 Cl C-1 C* M 0 ). 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CA @4 :6 r .", 21 ? ? @m 2cl) CA vu @ft w Cb -4 " @n V ra 4@ N) CA (A CA x J, :0 ;46 r 01 N) 10 kA GD ? ,A.Q"@Aolcolouv N) 14 46 14 Z fu W CA %M kA 0.- b@ -0 f f, :11 !" ? !4 21 =@ Fo Pi C3, Ol CA r%) @.n (A A 4@ x cx CA cv, ? ?1 :0 :4 !, !0 t3 43, 1,"- (A GO 10 CA ATTACHMENT 5-B SURFACE WATER FLOWS - SUBREGION 13 Effective Average . Drainage Area4 Flow 7 Day-10 Yr. Low Flow 7 Day-25 Yr. Low Flow 7 Day-50 Yr. Low Flow Stream Sq. Mi. MGD cfs/Sq. Mi. MGD cfs/SQ. Mi. MGD cfs/Sq. Mi. MGD Broad Creek 41 34 0.254 6.8 0.201 5.4 0.148 4.0 Deer Creek 171 140 0.254 28.0 0.201 22.1 0.148 16.3 Bush River 96 77 0.123 7.6 0.087 5.4 0.065 4.0 Little Gunpowder Falls 56 45 0.210 7.6 0.152 5.5 0.119 4.3 South Branch Patapsco River 76 49 0.057 2.8 0.027 1. J 0.017 0.8 Little Patuxent River2 161 108 0.121 12.6 0.095 9.9 0.081 8.4 Big Pipe Creek 102 63 0.066 4.3 0.038 2.5 0.025 1.7 -J Total 69.7 52.1 i 39.5 1Includes Piney Run 21ncludes Middle Patuxent 3Not including flow of Susquehanna River 4Me.asured at mouth or at interface of brackish water. W M ATTACHMENT 5-B (cont'd) SURFACE WATER FLOWS SUBREGION 2 Effective Average Drainage Area Flow 7 Day-10 Yr. Low Flow 7 Day-25 Yr. Low Flow 7 Day-50 Yr. Low Flow Stream Sq. Mi. MGD cfs/Sq. i. MGD cfs/Sq. Mi. MGD cfs/Sq. Mi. MGD Northeast River 44 37 0.086 2.4 0.061 1.7 0.049 1.4 Elk River 105 86 0.169 11.4 0.133 9.0 0.102 6.9 Chester River 181 112 0.154 18.0 0.112 13.1 0.094 11.0 Choptank Riverl 261 180 0.039 6.6 0.027 4.5 0.022 3.7 Nanticoke River2 549 425 0.185 65.5 0.145 51.4 0.132 46.8 3 Pocomoke River 465 330 0.037 11.1 U.UZ?j 8.4 0.023 6.9 Total 115.0 'Includes Tuckahoe Creek 2Includes Marshyhope Creek 31ncludes Dividing Creek SURFACE WATER FLOWS - SUBREGION 3 No significant stream flow during low flow periods. ATTACHMENT 5-B (cont'd) SURFACE WATER FLOWS - SUBREGION 4 Effective Average Drainage Area Flow 7 Day-10 Yr. Low Flow 7 Day-25 Yr. Low Flow 7 Day-50 Yr. Low Flow Stream Sq. Mi. MGD cfs/Sq. Mi. MGD cfs/Sq. Mi. MGD cfs/Sq. Mi. MGD Nanticoke River 339 262 0.185 40.5 0.145 31.7 0.132 28.9 Marshyhope Creek 83 64 0.185 9.9 0.145 7.7 0.132 7.1 I Total 50.4 Note: Above includes only drainage to Chesapeake Bay g xTpuaddV po m 0 :3 rt m @l0 0 0 OQ rt w P) En 1-4 rt 0 rt 1.6 lb H n m m w m .4 m F@ PV m ft m .4 H PV (D n 0 V4 t=p m n rt m m m H (n F4 Ft. H 0 @-h Ps M OQ 0 a% I@j (71 m rt 0 I'D %0 0 F@ m m P) 0 n > m Ln CD 14 a% F- M @-A 0 41 Fh @-4 OQ 1@ In m cn on M Fh M 113 CA t-j rt (a 0) tv el W 0 CD 0 m Ul Ln Ln OD IL F_n rl) Ln Pd F" H Pi 0 P 0 rt 0 Ln Z-1 03 :r. t CL En rn w r_ 0 C% En Fj cn 0 Ln 3 0 rt P-h 0 0 -4 z "I Ln En m CD 0 0 In H Li w w a% H. r., 41 41 0 Ln 41 0 0 14 00 0% 34 n -4 ra to C. CD 0 m I " tj a, Ln Ln Ln 0 0 Ln 41@ @o , !1-1 !", :4 00 tn Ln 9-q 9 xTpuaddV C') 10 > z z Pd 0 H. m '00 " . @o n r. 0 m ct @u I'd go 0 ::r ::r m ct @o > . 0 0 14 ft F, En 0 cn 0 .4 ct C. rt m m 0 ?1 m 0 m lb PC w -'IF ' m F, rt m m 0 m PU m 03 t-i Ptm CA Fl- @-h rpl) M" paM Li -j OQn 41 aqn 00 w mrt 1-11 %0 mrt CD Ul vi aN @o > > @tm @l fD m m cn En m C., m C., F@ OD N3 CD 41 03 U) -4 09 > m 0 M 0 -4 > 0 @4 @-h H rn t:J txj m tj t-I Pd CD Pd I? -m- 114, z 0 0 0 .0 1 --i as 0 -4 @o I_n OD C. cn cn 0 1 0 rt rt t@ cn pi W 0 H ai 2 W to 4.1 00 w 4.1 It txj F. 0 F@ (71 C) 00 @-h m rA tj -c-n CD MM I 14 F-- 41 co Ul 0 Lj 81 0 10 co -D lua Lo t.- OL4 0 -4 @h rA rn :j ? -co- C-n 00 Ln Ln @n @O 6 0 IUI 4.1 uj 0 " li 1@1 ATTACMENT 5-B (cont'd) Ln SURFACE WATER FLOWS - SUBREGION 9 Effective Average Drainage Area Flow 7 Day-10 Yr. Low Flow 7 Day-25 Yr. Low Flow 7 Day-50 Yr. Low Flow Stream Sq. Mi. MGD cfs/Sq. Mi. - MGD cfs/Sq. Mi. MGD cfs/Sq. Mi. MGD Mattaponi River 913 559 0.029 17.1 0.018 10.6 0.011 6.5 Pamunkey River 1,448 811 0.037 34.6 0.024 22.4 0.017 15.9 Chickahominy River 444 291 0.028 8-.0 0.016 4.6 0.010 2.9 Total 59.7 37.6 25.3 lFlow appropriated for use by Newport News (Subregion 10) SURFACE WATER FLOWS - SUBREGIONS 10, 11, and 12 No significant stream flow within Chesapeake basin during low flow periods. ATTACHMENT 5-C DEVELOPABLE GROUNDWATER RESOURCE The following discussion presents an overview of data sources and methodologies used to establish potential sustained groundwater yields in the 12 subregions of the Chesapeake Bay Study Area. SUBREGION 1: The sustained yields in this area were estimated at 200 mgd, based on results computed in the Maryland Water Supply Study, (Part II by the U.S.. Geological Survey) 1965. These in turn were based on studies published in various Bulletins of the Maryland Geological Survey. SUBREGIONS 2, 3, & 4: Results presented in Professional Paper 822 of the USGS: "Water Resources of the Delmarva Peninsula," 1973, were used to establish sustained groundwater yields for these three subregions. Yields from each of seven major aquifers were apportioned based on their areal extent beneath each of the subregions. Results of this analysis appear in the following table. Total S U B R E G 1 0 N Aquifer mgd 2 3 4 Non-marine Cretaceous 80 60 0 0 Magothy 10 7 0 0 Aquia-Rancocas 190 132 0 0 Piney Point-Cheswold 80 45 0 10 Federalsburg 50 17 0 15 Fredericka 50 9 0 8 Manokin-Pokomoke- Quaternary 1,040 480 248 209 749 248 241 Note: Balance of water available accrues to parts of Delaware out of Study Area. 4- Appendix 5 C-1 SUBREGION 5: Sustained yields in this area were based on USGS Circular No. 697, 1974 (48), and estimates presented in the Northern Virginia Water Quality Management Plan, 1973. These amount to 170 mgd and 11 mAd for Maryland and Virginia, respectively. SUBREGION 6: This area is estimated to have a sustained groundwater yield of 234 mgd. The estimated 324 mgd by the Maryland Water Supply Study was reduced by 40 mgd plus 50 mgd to compensate for that allocated to the Y D.C. area (Subregion 5) from the Magothy and Patapsco aquifer, respectively. This 90 mgd is included in the 170 mgd figure mentioned above. SUBREGIONS 7 - 12: Using figures derived for purposes of the NAR Study (49), sustained yields for Subregions 7 through 12 were found by apportioning according to area, as shown in the following table. These are rough figures that assume the supplies are everywhere equally available. - NAR AREA - - - 19: Potomac 20: Rap- York 21: James Chesapeake Bay Coastal Coastal Coastal Region Plain Plain Piedmont Plain Piedmont TOTAL 7 28 7 37 - - 72 8 - 7 21 19 28 75 9 28 72 - 10 - 110 10 - 6 - 2 - 8 11 - - 12 - 12 12 15 - 27 - 42(821) lincludes an additional 40 mgd presently used at Franklin, Virginia. The later figure is used for the overall total in Subregion 12. AnDendix 5 C-2 ATTACBNM 5-D EXISTING STORAGE FACILITIES Safe Yield Namp Location (mgd) Owner SUBREGION 1 Loch Raven - Prettyboy System Baltimore County 148.0 Baltimore Liberty Lake Patapsco River 95.0 Baltimore Atkisson Reservoir Harford County 11.0 Edgewood Arsenal 254.0 SUBREGION 2 none SUBREGIONS 3 and 4 none SUBREGION 5 Triadelphia - Rocky Gorge Washington Suburban System Patuxent River 43.0 Sanitary Commission Occoquan Creek Reservoir Fairfax County 65.0 Fairfax County Water Authority Goose Creek - Beaverdam Creek System Loudoun County 14.4 Fairfax City Broad Run Impoundment Prince William County 8.0 130.4 SUBREGION 6 none Appendix 5 D-1 ATTACHMENT 5-D (Cont'd) EXISTING STORAGE FACILITIES Safe Yield Name Location (mgd) Owner SUBREGION 7 Beaverdam Run Reservoir Aquia Creek 2.5 U. S. Marine Corps SUBREGION 8 Lake Chesdin Appomattox River 100.0 Appomattox River Water Authority Swift Creek Reservoir Chesterfield County 12.0 Chesterfield County Falling Creek Chesterfield County 3.6 Chesterfield County 115.6 SUBREGION 9 none SUBREGION 10 Lee Hall Reservoir Newport News Harwoods Mill Reservoir York County 40.0 Newport News Skiffes Creek Reservoir James City County Diascund Reservoir - James City County Big Bethel Reservoir Hampton 4.o Langley AFB Jones Pond York County 0.5 Cheatham Annex. 64.5 4 Appendix 5 D-2 ATTACHMENT 5-D (Cont'd) EXISTING STORAGE FACILITIES Safe Yield Name Location (mgd) Owner SUBREGION 11 North Landing Reservoir Virginia Beach Lake Burnt Mills City of Suffolk 73.0 Norfolk Lake Prince City of Suffolk Western Branch Reservoir City of Suffolk Speight's Run Reservoir City of Suffolk Lake Kilby City of Suffolk Lake Cohoon City of Suffolk 21 0 Portsmouth Lake Meade City of Suffolk 94.0 SUBREGION 12 Waller Pond York County 2.0 Williamsburg ADpendix 5 D-3 ATTACHMENT 5-E SIGNIFICANT INSTITUTIONAL WATER USERS, BY SUBREGION Use (mgd) Source SUBREGION I Aberdeen Proving Ground 2.5 Deer Creek & Wells Edgewood Arsenal 2.0 Winter's Run & Wells U. S. Naval Academy (includes Naval Ship R & D Center) 2.2 Wells Crownsville State Hospital (Anne Arundel Co.) 1.1 Wells Curtis Creek Coast Guard 0.6 Surface Springfield State Hospital (Carroll Co.) 1.3 Piney Run, South Branch Patapsco River Fort Meade (A. Arundel Co.) 3.5 Little Patuxent River & Wells Maryland House of Correction (A. Arundel Co.) 0.8 Dorsey Run & Patuxent River 14.0 SUBREGION 2 Bainbridge Naval Training Center (Cecil Co.) 1.5 Susquehanna River Perry Point Veterans Hospital (Cecil Co.) 0.5 Susquehanna River 2.0 A.Ppendix 5 E-1 ATTACHMENT 5-E (Cont'd) SIGNIFICANT INSTITUTIONAL WATER USERS, BY SUBREGION Use JLngd) Source SUBREGION 3 A.- no users of greater than 0.1 mgd SUBREGION 4 no users of greater than 0.1 mgd SUBREGION 5 Quantico Marine Base (Prince William Co.) 2.7 Chopawamsic & Aquia Creek & Wells Agricultural Research Center 0.7 Lorton Reformatory (Fairfax Co.) 1.6 Occoquan.Creek 5.0 SUBREGION 6 Patuxtent Naval Air Station (St. Marys Co.) 1.3 Wells U. S. Naval Ord nance Station (Charles Co.) 1.7 Wells 3.0 SUBREGION 7 U. S. Naval Ordnance Laboratory (King George Co.) 0.6 Wells 0.6 4 ADpendix 5 E-2 ATTACHMENT 5-E (Cont'd) SIGNIFICANT INSTITUTIONAL WATER USERS, BY SUBREGION Use (mgd) Source SUBREGION 8 Central State Hospital (Dinwiddie Co.) 0.7 Surface Richard Bland College (Prince George Co.) 0.1 Wells 0.8 SUBREGION 9 Camp A. P. Hill (Caroline Co.) 0.1 Wells 0.1 SUBREGION 10 Langley Air Force Base, NASA 4.o Big Bethel Reservoir Cheatham Annex (York Co.) 0.3 Jones Pond & Wells 4.3 SUBREGION 11 Norfolk Naval Shipyard 57.0 Surface (brackish) 57.0 SUBREGION 12 Frederick College (Suffolk Co.) 0.1 Wells 0.1 Appendix 5 E-3 .P ATTACHMENT 5-F AGRICULTURAL WATER USE SUMMARY*, mgd Subregion Type Use 1970 1980 1990 2000 2020 1 Irrigation 2.9 38.2 40.5 42.9 47.9 Livestock 2.5 2.9 3.1 3.2 3.5 Domestic 15.6 17.2 16.5 15.7 -18.4 Sub-Total 21.0 58.3 60.1 61.8 69.8 2 Irrigation 32.5 94.0 163.1 232.2 722.2 Livestock 4.2 2.7 2.6 2.6 2.2 Domestic 8.8 11.9 13.9 15.8 -20.5 Sub-Total 45.6 108.6 179.6 250.6 744.9 3 Irrigation 15.9 66.6 58.1 49.6 39.1 Livestock 0.2 0.1 0.1 0.1 0.1 Domestic 1.5 3.0 3.2 3.6 4.1 Sub-Total 17.6 69.7 61.4 53.3 43.3 4 Irrigation 12.2 96.9 103.0 111.3 136.8 Livestock 2.0 1.5 1.4 1.3 1.3 Domestic 3.6 6.0 6.9 7.8 8.7 Sub-Total 17.8 104.4 111.2 120.4 146.8 5 Irrigation 3.1 21.6 49.9 72.2 103.1 Livestock 1.7 1.5 1.3 1.1 0.9 Domestic 10.6 10.1 11.3 12.5 13.8 Sub-Total 15.4 33.2 62.5 85.8 117.8 6 Irrigation 3.7 14.4 47.5 80.6 112.7 Livestock 0.3 0.2 0.2 0.2 0.2 Domestic 4.3 5.8 5.5 5.1 3.9 Sub-Total 8.2 20.4 53.2 85.9 116.9 7 Irrigation tr. 0.8 1.2 1.6 2.1 Livestock 0.3 0.3 0.4 0.4 0.4 Domestic 2.0 3.4 3.7 4.0 2.4 Sub-Total 2.4 4.5 5.2 5.9 4.9 *Derived from Appendix 6: Agricultural Water Supply. Appendix 5 F-1 ATTACHMENT 5-F (Cont'd) Subregion Type Use 1970 1980 1990 2000 2020 8 Irrigation 1.8 21.6 42.1 62.5 70.7 Livestock 0.7 0.7 0.6 0.5 0.4 Domestic 4.9 7.9 8.5 9.1 9.9 Sub-Total 7.3 30.2 51.1 72.1 81.0 9 Irrigation 0.5 13.2 27.4 41.6 44.1 Livestock 0.6 0.6 0.6 0.6 0.6 Domestic 2.9 4.6 5.2 5.7 6.4 Sub-Total 4.0 18.5 33.2 47.9 51.1 10 Irrigation 0.2 0.3 0.4 0.4 0.9 Livestock tr. 0.1 0.1 0.1 0.2 Domestic 1.2 1.1 0.8 0.5 0.6 Sub-Total 1.4 1.5 1.3 1.1 1.6 11 Irrigation 4.4 9.3 8.8 8.4 9.1 Livestock 1.2 0.3 0.2 0.2 0.2 Domestic 0.6 3.3 3.1 2.9 2.5 Sub-Total 6.2 12.8 12.2 11.6 11.9 12 Irrigation 2.5 10.5 50.6 90.6 68.7 Livestock 0.6 0.9 1.0 1.0 1.3 Domestic 3.9 7.7 8.2 8.8 8.7 Sub-Total 7.0 19.2 59.8 100.5 78.7 tr. = trace Note : Irrigation use is that during the maximum application month of the dryest year in 10 for vegetables and specialty crops, and the dryest year in 5 for field crops and orchards. 4. Appendix 5 F-2 TD g X-Fpuz)ddV 0 \0 00 -.1 (71 cn 0 C@ > I W 00 w a w w C. "Iw > I > CL> > > > 0 ti" 0 1@ @4 1 > x z 0 > 0 -zi -@i 0 n r@ > > > m to (D "0 Id C: co P) IF 0 0 0(D :1= 7i a)0 CD :s r- IF W (D c-+ '. 0. ?'n(D 00 0 0 @o9(D (D (D a) tv0 10=I'D (D0 0c+ co a, @lT() a, to -j co 0 P- co a, ol 0 to 00 -A %_9m N) %ji C-- cn (D (D -1 ri)m 0 @d 1 0 (D CL ol U) co PO n 0 1 C7, -A 10 'P- \D 37: N CTI ID C, \0 00 Co cn 010 0 91 @4 coZ 0 > co n 10 p 10 co m C7,w -A N) 1@ la, 10 lp- -j0 C% -4 -j N) -,j 0n 0 C', 0 0m > (D 0 0 N r- \0 00 w 113 "A >@l 0 z IF 0 10 2: --j (D -1 0 tQ (D co 0 co ro oll -j rl) :n \0 0 \@ a', \0 -,A -1 -j 0 00 com 10 cc 0 CD co cr, 0 ;o --j P- 00 to 0 (D 0 m m m m 0 n m W m Ln + + + + + + + ++ to \.A -j 00 1-4 lp- I;-Nll@ C@ tzj @i til Chapter Page Delaware 59 Maryland 61 Virginia 6S Irrigation Water Demand 72 Assumptions and Methodology 72 Projected Demands 74 Delaware 74 Maryland 7S Virginia 82 Total Agricultural Water Demand 89 Future Supply 92 Assumptions 92 Sources of Supply 93 Surface Water 93 Ground Water 93 Available Water Supply 95 Future Needs and Problems 96 Erratic Supply 97 Problem 97 Solutions 100 Salinity 101 Problem 101 Solution 106 Environmental Pollutants 106 Fertilizer 107 Problem 107 Solutions 112- Pesticides 113 Problem 113 Solutions 114 Livestock Waste 115 Problem 115 Solutions 117 Sedimentation 119 Problem 119 Solution 120 Processing Wastes 121 Sensitivity Analysis 121 Population 121 Livestock 124 Irrigation 124 Summary 130 IV REQUIRED FUTURE STUDIES 131 4, Appendix 6 ii Chapter Page FOOTNOTES 135 REFERENCES 139 GLOSSARY 143 147 ACKNOWLEDGMENT ATTACHMENT A: 151 Projection by Shares Analysis Graphical Illustration ATTACHMENT B: 155 Rural Population Dwelling Unit Analysis Tables ATTACHMENT C: 163 Water Demands Projected to 1980, 2000, and 2020 -- Maps and Tables ATTACHMENT D: 203 Fertilizer and Livestock Waste Impacts Tables Appendix 6 LIST OF TABLES Number Title Page 6-1 CHESAPEAKE BAY STUDY, COMPOSITION OF SUBAREAS 5 6-2 CLIMATIC SUMMARY PRECIPITATION DATA MONTHLY NORMALS-YEARS 1931 THRU 1960 12 6-3 ANNUAL PER CAPITA USE OF WATER, HOUSEHOLDS WITH AND WITHOUT RUNNING WATER, CHESAPEAKE BAY STUDY AREA, 1950, 1960 AND 1970 is 6-4 POPULATION STATISTICS BY STATE AND SUBAREA, 1950, 1960 AND 1970, CHESAPEAKE BAY STUDY 16,17 6-5 RURAL DOMESTIC WATER USE, BY STATE AND SUB- AREA, 1950, 1960 AND 1970, CHESAPEAKE BAY STUDY 17 6-6 LIVESTOCK AND POULTRY NUMBERS, BY STATE AND 20, SUBAREA, 1950, 1959 AND 1969, CHESAPEAKE BAY 21 STUDY & 22 6-7 ANNUAL LIVESTOCK AND POULTRY WATER USE, CHESA- PEAKE BAY STUDY AREA, 1950, 1959, AND 1969 22 6-8 ANNUAL LIVESTOCK AND POULTRY WATER USE., BY STATE AND SUBAREA, 1950, 1959 AND 1969, CHESAPEAKE BAY STUDY 23,24 6-9 IRRIGATED FARMS, ACRES AND WATER USED, BY STATE AND SUBAREA, 1964 AND 1969, CHESAPEAKE BAY STUDY 26,27 6-10 IRRIGATED ACRES BY CROP, BY STATE AND SUB- AREA, 1969, CHESAPEAKE BAY STUDY 27 6-11 TOTAL POTENTIALLY IRRIGABLE LAND, WITH AND WITHOUT TREATMENT, BY STATE AND SUBAREA, 1969, CHESAPEAKE BAY STUDY 28 6-12 WATER USE BY TYPE OF USE, BY STATE AND SUBAREA, REPORTED YEARS, CHESAPEAKE BAY STUDY 29 6-13 PERCENTAGE OF WATER USE, BY TYPE AND COMPARISON WITH POPULATION AND LAND AREA, BY STATE AND SUB- AREA, 1969-1970, CHESAPEAKE BAY STUDY 30 INC- Appendix 6 iv LIST OF TABLES Number Title Page 6-14 RUNNING WATER USE RATES, FARM POPULATION 39 6-15 SMALL SYSTEM WATER USE RATE 41 6-16 AVERAGE MARKET WEIGHTS, LIVESTOCK AND LIVE- STOCK PRODUCTS, TARGET PROJECTION YEARS 56 6-17 LIVESTOCK WATER USE RATES: 1980, 2000, AND 2020, CHESAPEAKE BAY STUDY 57 6-18 LIVESTOCK NUMBER AND WATER USE COEFFICIENTS 57 6-19 ANNUAL AGRICULTURAL WATER USE BY SUBAREA PROJECTIONS TO 1980, 2000 AND 2020, CHESAPEAKE BAY STUDY 90 6-20 FARM ACREAGE AND AVAILABLE GROUND WATER: CHESAPEAKE BAY STUDY AREA 96 6-21 DROUGHT FREQUENCY 98 6-22 CROP SALINITY HAZARD AND TOTAL DISSOLVED SOLIDS (TDS) 102 6-23 NITRATE ACCUMULATIONS UNDER IRRIGATED GRAIN SORGHUM FIELDS ON A SLOWLY PERMEABLE SOIL FERTILIZED WITH VARYING RATES OF AMMONIUM SULFATE 110 6-24 ANNUAL SOIL AND NUTRIENT LOSSES, BY CROP 112 6-25 CHLORINATED HYDROCARBON INSECTICIDES AND RELATED COMPOUNDS IN MAJOR RIVERS OF THE UNITED STATES 114 6-26 NITRATE CONTENT OF SOIL CORES AND WATER BENEATH VARIOUS LAND-USE PATTERNS IN COLORADO 116 6-27 AVERAGE REDUCTIONS OF VOLATILE SOLIDS, COD, AND K.JALDAHL NITROGEN IN 12 TO 15-DAY LABORATORY AERATION STUDIES CONDUCTED AT TWO TEMPERATURES 118 6-28 ANTICIPATED RESULTS OF AN ANAEROBIC LAGOON RECEIVING ANIMAL WASTES IN A MODERATE CLIMATE 119 Appendix 6 v LIST OF TABLES Number Title Page 6-29 ESTIMATED POLLUTION LOADINGS OF SELECTED AGRICULTURAL PROCESSING INDUSTRIES 122 6-30 SERIES "C" AND "Ell POPULATION PROJECTIONS, CHESAPEAKE BAY ESTUARY AREA 123 6-31 EFFECT OF VARYING RATE OF IRRIGATION EFFICIENCY ON PROJECTED IRRIGATION WATER DEMAND 125 6-32 DISTRIBUTION OF IRRIGATION WATER DEMANDS BY MONTH, FOR NORMAL AND DRY YEARS: PROJECTIONS TO 1980, 2000, AND 2020, CHESAPEAKE BAY STUDY AREA 128 Appendix 6 vi LIST OF FIGURES Number Title Page 6-1 CHESAPEAKE BAY STUDY AREA 6 6-2 MONTHLY MEANPRECIPITATION. CHESAPEAKE BAY STUDY AREA 12 6-3 FALL LINE AND UNDERLYING SEDIMENTS, CHESAPEAKE BAY STUDY AREA 13 6-4 PROJECTED NATIONAL FRAMEWORK OF PRODUCTION REQUIREMENTS 37 6-5 WATER SERVICE IN 1970: POPULATION SERVED BY CENTRAL SUPPLY SYSTEMS, AND RESIDUAL POPULATION (INDEPENDENTLY SERVED). CHESAPEAKE BAY STUDY AREA. 40 6-6 RESIDUAL WATER DEMAND IN DELAWARE: PROJECTIONS TO 1980, 2000 AND 2020. 42 6-7 RESIDUAL WATER DEMAND IN MARYLAND: PROJECTIONS TO 1980, 2000, AND 2020. 43 6-8 RESIDUAL WATER DEMAND IN VIRGINIA: PROJECTIONS TO 1980, 2000 AND 2020. 48 6-9 LIVESTOCK WATER DEMAND IN DELAWARE: PROJECTIONS TO 1980, 2000, AND 2020. 60 6-10 LIVESTOCK WATER DEMAND IN MARYLAND. PROJECTIONS TO 1980, 2000, AND 2020. 62 6-11 LIVESTOCK WATER DEMAND IN VIRGINIA, PROJECTIONS TO 1980, 2000, AND 2020. 66 6-12 IRRIGATION WATER DEMAND IN DELAWARE, PROJECTIONS TO 1980, 2000, AND 2020. 75 6-13 IRRIGATION WATER DEMAND IN MARYLAND. PROJEC- TIONS TO 1980, 2000, AND 2020. 77 6-14 IRRIGATION WATER DEMAND IN VIRGINIA. PROJEC- TIONS TO 1980, 2000, AND 2020. 83 6-15 TOTAL AGRICULTURAL WATER DEMANDS, CHESAPEAKE BAY STUDY AREA 91 Appendix 6 vii Number Title Page 6-16 CHANGE IN SOYBEAN YIELDS DUE TO MOISTURE STRESS.APPLIED AT SELECTED PERIODS OF GROWTH 98 6-17 RAINFALL BY MONTH: MEAN, AND 80 PERCENT CHANC-E OF OCCURRENCE, AND 90 PERCENT CHANCE OF OCCURR- ENCE. CHESAPEAKE BAY STUDY AREA. 99 6-18 SALT TOLERANCE OF VEGETABLE CROPS 103 6-19 SALT TOLERANCE OF FIELD CROPS 103 6-20 SALT TOLERANCE OF FORAGE CROPS 103 6-21 TOLERANCE TO SALINITY: HUMAN, CROP, LIVESTOCK 104 6-22 EXTENT TO BRACKISH WATER IN MARYLAND 105 6-23 NITRATE-N IN THE UPPER 8 FEET OF 4 SOIL TYPES AFTER THE ANNUAL APPLICATION OF N FERTILIZER FOR 7 YEARS TO CONTINUOUS CORN IN MISSOURI 109 6-24 NITRATE-NITROGEN FOUND IN SHARPSBURG SILTY CLAY LOAM PROFILES AFTER CORN HARVEST, AS AFFECTED BY IRRIGATION AND AMOUNTS OF APPLIED NITROGEN 110 6-25 MONTHLY LOSSES OF NO -N AS RELATED TO RUNOFF AMOUNTS, NO -N CONCE11TRATION IN RUNOFF AND FERTILIZATI6N. ill 6-26 AVERAGE NITRATE-NITROGEN DISTRIBUTION WITH DEPTH OF PROFILES AS AFFECTED BY DIFFERENT LAND USES IN EASTERN COLORADO. 116 6-27 LOCATION OF WELLS AND NITRATE CONTAMINATION FROM FEEDLOTS. 118 6-28 URBAN USES DISPLACE AGRICULTURAL LANDS IN THE CHESAPEAKE BAY STUDY AREA 120 6-29 IRRIGATION WATER DEMAND IN MARYLAND SUBAREA 3: PROJECTIONS BASED UPON OBERS ACREAGE PROJECTIONS AND INDIVIDUAL ACREAGE ESTIMATES 126 Appendix 6 viii Number Title Page 6-30 IRRIGATION WATER DEMAND IN MARYLAND SUBAREA 5: PROJECTIONS BASED UPON OBERS ACREAGE PROJECTIONS AND INDIVIDUAL ACREAGE ESTIMATES 126 6-31 IRRIGATION WATER DEMAND IN VIRGINIA SUBAREA 1: PROJECTIONS BASED UPON OBERS ACREAGE PROJECTIONS AND INDIVIDUAL ACREAGE ESTIMATES 126 6-32 IRRIGATION WATER DEMAND IN VIRGINIA SUBAREA 3: PROJECTIONS BASED UPON OBERS ACREAGE PROJECTIONS AND INDIVIDUAL ACREAGE ESTIMATES. 127 6-33 IRRIGATION WATER DE14AND IN VIRGINIA SUBAREA 4: PROJECTIONS BASED UPON OBERS ACREAGE PROJECTIONS AND INDIVIDUAL ACREAGE ESTIMATES 127 6-34 IRRIGATION WATER DEMAND IN VIRGINIA SUBAREA 8: PROJECTIONS BASED UPON OBERS ACREAGE PROJECTIONS AND INDIVIDUAL ACREAGE ESTIMATES 127 6-35 TOTAL WATER DEMANDS, 1950-1970, AND PROJEC- TIONS TO 1980, 2000, AND 2020. IRRIGATION ESTIMATED FOR NORMAL AND DRY YEARS, CHESAPEAKE BAY STUDY 129 Appendix 6 ix CHAPTER I THE STUDY AND THE REPORT AUTHORITY The authority for the Chesapeake Bay Study and the construction of the hydraulic model is contained in Section 312 of the River and Harbor Act of 1965, adopted 27 October 196S, which reads as follows: a. The Secretary of the Army, acting through the Chief of Engineers, is authorized and directed to make a complete inves- tigation and study of water utilization and control of the Chesapeake Bay Basin, including the waters of the Baltimore Harbor and including, but not limited to, the following: navi- gation, fisheries, flood control, control of noxious weeds, water pollution, water quality control, beach erosion, and recreation. In order to carry out the purposes of this section, the Secretary, acting through the Chief of Engineers, shall construct, operate, and maintain in the State of Maryland a hydraulic model of the Chesapeake Bay Basin and associated technical center. Such model and center may be utilized by any department, agency, or instrumentation of the Federal Government or of the States of Maryland, Virginia, and Pennsylvania, in connection with any research, investigation or study being carried on by them of any aspect of the Chesapeake Bay Basin. The study authorized by this section shall be given priority. b. There is authorized to be appropriated not to exceed $6,000,000 to carry out this section. Appendix 6 1 An additional appropriation for the study was provided in Section 3 of the River Basin Monetary Authorization Act of 1970, adopted 19 June 1970, which reads as follows: In addition to the previous authorization, the completion of the Chesapeake Bay Basin Comprehensive Study, Maryland, Virginia, and Pennsylvania, authorized by the River and Harbor Act of 1965 is hereby authorized at an estimated cost of $9,000,000. As a result of the extensive damage caused by Tropical Storm Agnes in the Chesapeake Bay, Public Law 92-607, the Supplemental Appro- priation Act of 1973, signed by the President on 31 October 1972, included $275,000 for additional studies of the impact of the storm on the Chesapeake Bay. The District Engineer, Baltimore District, was assigned the Chesa- peake Bay Study on 3 December 1965. Subsequently, the Chief, Planning Division, Baltimore District, entered into contract with the Economic Research Service to perform a rural water use study in support of the authorized Chesapeake Bay Study. The Economic Research Service is authorized under Section 601 of the Economy Act (31 U.S.C. 886) to enter into interservice agree- ments or arrangements to work for reimbursement for other Federal agencies. The products of the agreement between the Corps of Engineers and the Economic Research Service were a section of the Existing Conditions Report and this Appendix. PURPOSE The Rural Water Use Appendix is a component of the Chesapeake Bay Study undertaken by the Baltimore Corps of Engineers. The objec- tives of the Study, as stated in the Chesapeake Bay Plan of Study, are to: a. Assess the existing physical, chemical, biological, eco- nomic and environmental conditions of Chesapeake Bay and its water resources. b. Project the future water resources needs of Chesapeake Bay to the year 2020. Appendix 6 2 c. Identify the additional studies to include hydraulic model tests that are needed to formulate a water resources management program for the Bay. The Chesapeake Bay Existing Conditions Report, which was published in 1973, met the first objective of the study by presenting a detailed inventory and documentation of the existing condition of Chesapeake Bay and its water resources. The report, divided into a summary and four supporting appendices, presents an overview of the people residing in the Bay area and the economy; a survey of the land surrounding the Bay and its use; and a description of the Bay itself, its life forms and hydrodynamics. The purpose of the Future Conditions Report, as distinct from the study itself, is to provide a format for presenting the findings of the Chesapeake Bay Study. The report, which satisfies the last two objectives of the study, describes the present use of the resource, presents the demands to be placed on the resource to the year 2020, assesses the ability of the resource to meet future demands and identifies the additional studies required to develop a management plan for the Chesapeake Bay. The purpose of this Appendix on Agricultural Water Supply is to (a) appraise the historical and existing rural water use by subarea; (b) forecast future agricultural activity in the Chesapeake Bay Area; (c) estimate future water use resulting from such activity; (d) determine future water needs of rural nonfarm residents depend- ent upon wells; and, (e) identify possible problems and conflicts resulting from projected agricultural production and water use, and (f) assess possible means to satisfy future needs. SCOPE This Appendix identifies and quantifies current agricultural uses of water in the study area. Agricultural demands are then estimated for the target date period through the year 2020. Finally, the ability of the region to meet those demands is addressed, along with their impacts and the potential problems and conflicts engen- dered by the demands. An attempt is also made to test the sensi- tivity of the water use projections by varying several of the basic assumptions made in the analysis. Appendix 6 3 The conclusions reached are based upon analyses of historical and projected water use in rural areas of fifty-six counties in the Chesapeake Bay area. The counties are located in the States of Delaware, Maryland and Virginia, and are aggregated into fourteen subarea groupings of counties which follow the component state's planning districts. As shown in Table 6-1 and Figure 6-1, five of the subareas are in Maryland and eight are in Virginia. The State of Delaware constitutes a subarea by itself. Because this Appendix addresses rural water supply needs, water use in major cities such as Baltimore and Wash- ington is not included. Rural domestic water use for farms and for rural residents not served by municipal systems, livestock consumption, and irrigation water use are addressed in the analysis. In the estimation of irrigation and livestock water demand, projections are made separately for different types of agricultural production, includ- ing 16 selected crops and 8 types of livestock, poultry and dairy products. Water use in the study area is projected to target years of 1980, 2000, and 2020, based upon historical data extending from 1949 to 1970. Among the historical data sources are the United States Censuses of Agriculture and Population, projections of aggregated agricultural production by OBERS (see Glossary for definition), and selected demographic projections furnished by the Baltimore District., Corps of Engineers. SUPPORTING STUDIES Nearly all of the comprehensive river basin studies have est- imated future rural and urban water use as a part of their . overall responsibilities. The North Atlantic Regional Water Resources Study, which included the entire Chesapeake Bay area, served as an important source to this Appendix. Future water use rates were derived and updated from work reported in the Water Supply Appendix.to the Great Lakes River Basin Study (1973). Estimates of future agricultural production of crops and livestock, upon which the water use calculations were based, were derived Appendix 6 4 TABLE 6-1 CHESAPEAKE BAY STUDY COMPOSITION OF SUBAREAS Subarea County Subarea County DELAWARE VIRGINIA Kent 1. Accomack New Castle Northampton Sussex 2. Fairfax Loudoun Prince William MARYLAND 3. King George Spotsylvania 1. Anne Arundel Stafford Baltimore Carroll 4. Chesterfield Harford Dinwiddie Howard Hanover Henrico 2. Caroline Prince George Cecil Kent 5. Caroline Queen Annes Charles City Talbot Essex King & Queen 3. Dorchester King William Somerset Lancaster Wicomico - New Kent Worcester Northumberland Richmond 4. Montgomery Westmoreland Prince Georges 6. York 5. Calvert Charles 7. Chesapeake City St. Marys Virginia City 8. Gloucester Isle of Wight James City Mathews Middlesex Nansemond Southampton Surry Appendix 6 S CHESAPEAKE BAY STUDY AREA New Baltimore astlt Word /Anne Veen Ktot Ciro- line Prince car t Ford X Sussex Pfincc (at illiam art DEL._. chode Dorchester tatfor Marys wicomico ornerse est Caroline h mond umbesiwl Est @?Os Lan .coma( %onovat 1119 (aster ;Cnri(O lid le @ (,, 1. 011t (hall s . m titerf ield City am Prince it ctar urry file a Wight 7 nstmot% ity @Of C FIGURE 6-1 Appendix 6 6 from State-level OBERS projections of the Water Resources Council. Finally, an earlier special study of current and historical agri- cultural water use was completed by ERS in 1972, for the Chesapeake Bay Study. Summarized in the Existing Conditions Report, it formed the basis for the analysis in this Appendix. There has also been coordination with Appendix 5 of the Chesapeake Bay Study in which municipal and industrial water supply are discussed. STUDY PARTICIPANTS AND COORDINATION The District Engineer of the Baltimore District, Corps of Engineers has the overall management responsibility for the Chesapeake Bay Study. Because of the magnitude of the study and the complexity of the problems to be analyzed, a study organization composed of representatives from Federal agencies and the involved states was formed early in the study. Each agency represented has been charged with exercising leadership in those disciplines in which it has special competence and is expected to review and comment on work performed by others. To facilitate coordination among the study participants an Advisory Group, a Steering Committee and five working task groups have been formed. This Appendix was prepared under the general responsibility of the Water Quality and Supply, Waste Treatment, Noxious Weeds Task Group. The Economic Research Service> Agriculture's repre- sentative to the Task Group, conducted the required technical studies and prepared the Appendix. Membership and organization of the Task Group is as follows: WATER QUALITY AND SUPPLY, WASTE TREATMENT, NOXIOUS WEEDS TASK GROUP Environmental Protection Agency (Chairman) Agriculture - Economic Research Service Commerce - National Marine Fisheries Service Corps of Engineers Energy Research and Development Administration Federal Power Commission Interior - Bureau of Mines and U.S. Geological Survey Appendix 6 7 Navy State of Delaware State of Maryland State of Pennsylvania State of Virginia District of Columbia Susquehanna River Basin Commission Transportation - Coast Guard Substantial contribution was made to this Appendix by the Soil Conservation Service, USDA, who provided the analysis and pTojec- tions of irrigation water use. The Office of Business Economics, Department of Commerce, and Corps of Engineers were also important contributors, respectively, of data pertaining to population and to the residual populations unserved by central water systems. Appendix 6 8 CHAPTER II AGRICULTURAL WATER SUPPLY IN THE CHESAPEAKE BAY REGION DESCRIPTION OF REGION THE CHESAPEAKE BAY REGION, RESOURCES AND HISTORY The Chesapeake Bay Study Area is located in the southern portion of the northeastern urban complex in the United States, a sprawling chain of urbanized areas extending from Northern Virginia to Massachusetts. There.has been a general postwar movement into urban areas from rural areas in the United States, but along this urban complex the movement has been even more pronounced than for the country as a whole. (1) In the Chesapeake Bay Estuary Area, ( 2) the population has increased by 60 percent since 1950; from 4,947,215 in 1950 to 7,872,041 by 1970. In the same period, however, the urban population increased by almost 73 percent, while the rural population increased only 16 percent. The urban share of the Estuary Area total population jumped from 7S percent in 1950 to 81 percent by 1970. During the same period, there has been a sharp shift from agri- culture to other areas of employment. As a result of mechanization and other changes, productivity per farm worker has risen at an unprecedented rate. Thus, despite increases in food consumption,the number of agricultural workers has decreased not only as a propor- tion of all workers, but also absolutely. Again, this movement Appendix 6 9 has been more pronounced in the Chesapeake Bay Study Area than in the country as a whole. (3) In 1950 the farm population in the study area was 345,541, or 29 percent of the rural population, and the farm population constituted 7 percent of the total pop- ulation. By 1970 it had decreased.to 98,588, or 7 percent of the rural population and slightly over 1 percent of the total popu- lation. The effect of these population shifts has been two-fold. First, the shift in the rural population from farm to nonfarm has had a significant effect upon domestic water use. The rural nonfarm population has traditionally enjoyed a higher income than the farm population, and can afford more water consuming conveniences. Its water use rate is thus substantially higher than that of the farm population. When the rural population shifts from farm to nonfarm, therefore, rural domestic water demand is increased over what it would be if the farm-nonfarm relation remained constant. Second, the increase in the rural nonfarm population directly affects both the quantity and distribution of land in farms, and hence it significantly affects agricultural demand for water. The rural nonfarm population has exerted an ever increasing demand for land and housing, and it places a value on land with which less profitable agricultural uses simply cannot compete. In response to this pressure, the quantity of land in farms in the Chesapeake Bay Study Area fell from 7.5 million acres in 1949 to 5.1 million acres in 1969, a reduction of thirty percent. Remaining agricultural production is concentrated in the areas with the greatest competitive advantage, where agriculture can compete with alternative uses of land such as residential and recreational uses. The increase in demands of the nonfarm pop- ulation for land thus effects a spatial redistribution and concen- tration of agricultural production. Since the conversion of agricultural land to urban and industrial uses has been most pronounced near the expanding centers of Washington, Baltimore, and Norfolk, these demographic and water use trends have been sharpest in those areas. The Chesapeake Bay Study Area is situated largely in the Atlantic Coastal Plain, with western portions in the Piedmont and Appalachian physiographic provinces. The Atlantic Coastal Plain, separated from the Piedmont by the Fall Line, stretches from Long Island, New York, to the Gulf of Mexico. It is the center of deposition for sediments from the uplifted areas to the west of the Fall Line, and is underlain by a series of unconsolidated, coarse sedi- mentary deposits'. The deposits rest on a basement complex of igneous and metamorphic rock, and they range in thickness from a featheredge at the Fall Line, to 9000 feet at a location north of Appendix 6 10 Ocean City, Maryland (see Figure 6-3). Their slope varies from 50 feet per mile to 160 feet per mile. The sediments thus dip eastward from successive outcrop areas, and are encountered at increasingly great depths. The Piedmont is a relatively narrow, moderate relief plateau between the Coastal Plain and the mountains. It is composed of crystalline rock of the igneous and metamorphic classes, rock which to the east forms the basement complex beneath Coastal Plain sediments. The climate of the study area is best described as temperate. The average annual temperature is 57 degrees Fahrenheit, varying from 37 degrees in January and February to 78 degrees in July. The average temperature during the crop growing season, from April to September, is 70 degrees. (4) Rainfall in the study area averages 44 inches per year. The average varies, however, with location, from less than 40 inches per year to more than 47 inches. Precipitation varies with the season, as well, and most falls during the spring and summer months (see Table 6-2 and Figure 6-2). Descriptive Publications An extensive survey of the water resources of the Delmarva Peninsula, with maps, was completed in 1973 and is available from the U.S. Geological Survey (1973). Also available from the Geological Survey is a study of the water resources in the State of Maryland (1970). The State of Virginia has conducted an elaborate study of its agricultural water resources, including projections to 2020 (1969). PRESENT STATUS Historical rural water use in the Chesapeake Bay Study Area is the summation of three major uses: rural domestic, livestock and poultry, and irrigation. Rural domestic water use is by far the largest component and consists of the water used by rural farm Appendix 6 TABLE 6-2 CLINATIC SWIMARY-PRECIPITATION DATA MONTHLY NORMALS-YEARS-1931 thru 1960 Station Jan Feb Nat Apr Nay June July Aug Sep Oct Nov Dec Annual Elkton, Md. 3.46 2.99 4.19 3.60 4.25 3.96 4.35 5.02 3.56 3,23 3.55 3.19 45.35 Annapolis, Md. 3.14 2.57 3.62 3.31 3.83 3.51 4.14 4.50 3.46 2.63 2.78 2.85 40.34 Crisfield. Md. 3.56 3.15 4.01 3.66 3.69 3.31 5.05 5.05 3.83 3.37 3.24 2.92 44.89 Salisbury, Md. 3.66 3.21 4.13 3.34 3.62 3.49 4.39 6.01 4.44 3.50 3.21 3.13 46.13 Baltimore, Nd. 3.43 2.89 3.82 3.60 3.98 3.29 4.22 5.19 3.33 3.18 3.13 2.99 43.05 w Coleman, Nd. 3.61 2.93 3.86 3.43 4.17 3.64 4.29 4.97 3.71 3.08 3.41 3.18 44.28 Solomons, Md. 3.55 2.78 3.61 3.50 3.76 3.45 5.57 5.00 3.59 3.11 3.33 2.97 44.22 Washington, DiC. 3.03 2.47 3.21 3.15 4.14 3.21 4.15 4.90 3.83 3.07 2.84 2.78 40.78 Richmond, Va. 3.46 2.90 3.42 3.15 3.72 3.75 5.61 5.54 3.65 3.00 3.04 2.97 44.21 Norfolk, Va. A.P. 3.33 3.21 3.45 3.16 3.36 3.61 5.92 5.97 4.22 2.92 3.05 2.74 44.94 Source: Existing Conditions Report, Vol. II. 6 in. - 5 in. - 4 in. - 3 in. 2 in. 1 in Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 4- Kw@E 6-2 Monthly mean precipitation. Chesapeake Bay Study Area. Source: Present Conditions Report, Vol II Appendix 6 12 .T- Ceti '-'eareall Notk( Co.,, wil I BALTIMO Noward Kent IA"n@ to If bander lost /-@. 7)l2tla I Figure 6-3 WASHI GT N D. cals-1 Prin fair andill I Prince 8164 Fall Line and Underlying Sediments, Chesapeake Bay Study Area Charles A DEL fler`4 0 St. Dorchester j, INI @ -- Mary& 4 wi 10 J# spot ail Worcester omrw West, 1, -d Carolina I % Essex 1. /J-N K in H over tKi. ton faster svilliorn No HCH qND In' Ife'l so C, 'I., icily or to PETEgSBU It Suit S !"trip jo I is of NORFOLK' /par, PIEDMONT S, .A co q quaternary deposits V- - CONSOLIDATED ROCK It;) -,I IV-1 'A% dOASTAL PLAIN DEPOSITS Sands,,Gravels, SiItS a CIQYs Source: Modified from Maryland Geological Survey: Water in Maryland. 1970 Appendix 6 13 and rural nonfarm populations. Irrigation water use is the sec- ond largest rural water demand; it accounted for 25 percent of rural domestic water use in 1970. The third largest rural water demand is exerted by livestock and poultry, with about 25 percent of the 1970 rural total. Rural industrial water use was not evaluated for this Appendix, but it is included in the Municipal and Industrial Water Supply Appendix. This section of the report describes historical water use by the nonsystem served domestic, livestock and poultry, and irrigation sectors of the rural economy. Rural domestic water use is est- imated for 1950, 1960, and 1970, livestock and poultry water use for 1950, 1959, and 1969, and irrigation water use for 1964 and 1969. The historical years chosen for analysis of each major use depended upon the availability of Census of Population and Census of Agriculture information. The historical uses summarized in this section are described in detail in Rural Water Uses 1950- 1960-1970 Chesapeake Bay Study Area by John W. Green and available from Economic Research Service, USDA, Broomall, Pa. RURAL DOMESTIC WATER USE The rural population, composed of a rural farm component and a rural nonfarm component, are the major users of water in rural areas. Table 6-4 presents population statistics for the Chesa- peake Bay Study Area and its subareas. Rural population increased 16 percent in the study area between 1950 and 1970. Rural popu- lation in 1970 was 1,368,364, of which 1,275,568 were classified as rural nonfarm and 92,796 as rural farm. The rural farm pop- ulation decreased significantly between 1950 and 1970 but the loss was more than matched by the gain in rural nonfarm popu- lation. Water consumption rates differ for persons with and without run- ning water in their homes. The first step in estimating rural domestic water use was therefore to determine what proportion of the rural population had running water and indoor plumbing in their homes. Since the proportion of homes without such facilities was not expected to be the same for nonfarm and farm households, a dwelling unit analysis was carried out for each group and the data aggregated to determine total rural domestic water use. The dwelling unit analysis consisted of determining the percentage of rural nonfarm and farm dwelling units with running water and Ar multiplying these percentages by the appropriate population number Appendix 6 14 to determine rural nonfarm and farm population served by running water. The population numbers were then multiplied by appropriate water use rates and the results added to obtain total rural dom- estic water use. The Census of Housing reports the number of dwelling units with various combinations of modern facilities. Table 6-B-1 of Attach- ment B shows the total number of nonfarm dwelling units in 1950, 1960, and 1970. It also shows the number of units with running water, toilet, and bath. From this data, the percentage of units with modern facilities was computed. This percentage was then multiplied by the corresponding rural nonfarm population shown in Table 6-4 to determine the rural nonfarm population served by running water, toilet, and bath. It was assumed that the average number of persons per household does not vary with the availability of modern facilities. Table 6-B-2 presents the results of a similar analysis for the rural farm population. Table 6-B-3 shows the aggregated data from Tables 6-B-1 and 6-B-2. The percentage of the rural population served by running water increased substantially from 1950 to 1970, from less than 41 percent to almost 80 percent. In both 1950 and 1960 the per- centage of rural farm dwelling units (and therefore population) served by running water was less than the percentage of rural nonfarm units so served. In 1970, however, the order was reversed in all three state subareas. Table 6-3 shows annual per capita water use rates for households with and without running water in 1950, 1960, and 1970. The use rates were obtained from information published in the U.S. Geological Survey. Table 6-3--Annual pei capita use of water, households with and with- out running water, Chesapeake Bay Study Area, 1950, 1960, and 1970 State and water facility available 1950 1960 1970 Delaware --------- Gallons per capita ---------- With running water 18,250 18,250 21,900 Without running water 3,650 3,650 3,650 Maryland With running water 18,250 18,250 18,250 Without running water 3,650 3,650 3,650 Virginia With running water 18,250 18,250 18,250 Without running water 3,650 3,650 3,650 Source: Estimated Use of Water in the U.S. - 1950-1960-1970, USGS Circulars 115 456, and 676, respectively. Appendix 6 is Attachment Table 6-B-4 presents rural population and water use figures for households with and without running water for 1950, 1960, and 1970. Table 6-5 aggregates the with and without numbers to present total rural domestic water use by state and subarea for 1950, 1960, and 1970. Rural domestic water use in the Chesapeake Bay Study Area increased from-11.3 billion gallons in 1950 to 21.3 billion gallons in 1970. This 88 percent increase was due to installation of plumbing facilities in older homes and to new home construction for the increased rural nonfarm population. Delaware accounted for 5 percent of the total rural domestic water use in 1970, Maryland for 55 percent, and Virginia for 40 percent. Delaware increased its rural water consumption by 121 percent between 1950 and 1970, Maryland by 86 percent, and Virginia by 88 percent. Table 6- 4 -Population statistics by state and subarea, 1950, 1960 and 1970, Chesapeake Bay Study State and Total population. Rural pofflation 1950 1960 1970 subarea 1960 1970 1950 CHESAPZUM BLY 1,918.786 3,004,452 4,321,316 1,276,937 1,359.012 1.368,364 DELAWARE 61,336, 73,145 80,330 49.620 59,484 68,903 MARYLAND 1,141,305 1,896.927 2,722,364 581,251 693,061 736,555 Study Are* I---------- 507,473 867,721 1,164,911 257.853 313,562 326,233 2--------- z 99,274 121,498 131,322 86.050 105.570 110,418 3--------- : 111,349 122,072 127.007 :78,978 86.662 93,512 4---------- 358,583 698.323 1,183,376 93.744 106,993 107.410 5---------- 64,626 87.313 115.748 64.626 80,274 98,982 VIRGINIA 716,145@ 1,034.330 1,518,602 546.066 606,467 562,906 Study Area 1 --------- 51,132 47,601 43,446 48,408 47,601 43,446 2---------- : 142,316 349,715 603.273 115.355 120,545 111,964 3---------- : 30,532 37,938 49,050 30,532 37.938 49,050 4------ ---: 158,243 258,539 322,836 113,721 139,288 122,249 5---------- 76,549 79,639 81.818 76,549 79,639 79.218 6---- 11,750 21,583 33,203 11,750 15,629 25,437 7---------- 142,214 127,736 261.686 55,699 56.884 12,418 8---------- 103,409 111,579 123,290 94,052 108,943 119,124 Source: 1950, 1960, and 1970 Census of Population. Population does not Include Baltimore, Washington, D.C.. or independent Virginia cities. Only Sussex County is Included In Delaware totals. Appendix 6 16 Table 6- 4 Population statistics by state slid subarea, 1950, 1960 and 1970, Chesapeake Bay Study--Continued State and Rural nonfarm population Rural farm population subarea 1950 1960 1970 1950 1960 1970 CHESAPEAKE BOLY 848,203 1,176,934 1,275,568 328,734 182,078 92,796 DELAWARE 32,202 47,679 63,335 17,418 11,805 5,568 @LkRYLAND 434,201 604,748 685,111 147,050 88,313 51,444 A Study Area 1---------- : 204.796 294,294 307,961 53,057 29,26B 18,272 2---------- : 60,170 88,198 100,248 25,880 17,372 10,170 3------ --: 54,879 72,275 85,735 24,099 14,387 7,777 4--------- 71,852 95,199 101,394 21,892 11,794 6,016 42.504 64.782 89,773 22,122 15,492 9,209 VIRGINIA 381,800 524,507 52@,122 164,266 81,960 35,784 Study Area 1---------- 34,296 40.142 41.342 14,112 7,459 2,104 2--------- 91,642 110,693 108,374 .23,713 9,852 3,390 3---------- 19,309 33,870 47,338 11.223 4,068 1,712 4---------- $0,376 123,969 113,224 33,345 15,319 9,025 5---------- 43,539 62,471 72,263 33,010 17.168 6,955 6---------- 10,535 15,208 25,175 1,215 421 2J2 7---------- 46,146 52,262 11,043 9,553 4,622 1.3 5 8---------- 55,957 85,892 108,363 38,095 23,051 10,7 1 Source: 1950, 1960 and 1970 Census of Population. Table 6-5 -Rural domestic water use, by state and subarea, 1950, 1960 and 1970, Chesapeake Bay Study State and Domestic water use subarea :1 1950 1960 1970 --------------- Million gallons ------------------- CHESAPEAKE BAY 11,280.2 18,739.3 21.278.1 DELA14ARE 517.9 828.8 1,146.9 MARYLAND 6,323.8 10,038.4 11,780.4 study Area 1---------- : 3,046.9 4,851.3 5,462.2 2---------- : 828.2 1,441.6 1,675.8 3-------- - : 665.9 1,061.0 1,325.8 4------ ---: 1,145.8 1,602.7 1,823.0 5--------- 637.0 1,081.8 1,493.6 VIRGINIA 4,438.5 7,872.1 8,350.8 Study Area I---------- 367.4 501.9 528.1 2---------- 871.9 1.793.3 1,868.3 269.2 481.3 753.6 4-- - - -- - -: 1,019.8 1,982.8 1.945.9 5---------- : 572.5 873.8 1,017.2 6-------- -: 121.4 237.8 436.3 7---------- : 555.2 793.9 184.7 8---------- : 661.1 1.267.3 1,616.7 Appendix 6 17 LIVESTOCK AND POULTRY WATER USE Livestock and poultry water consumption is another component of rural water use. Water is required to sustain these animals and to produce farm-marketed livestock and poultry products. Livestock and poultry water use was determined by multiplying inventory numbers or, where appropriate, numbers of animals sold alive listed in Table 6-6 by the animal water use rates listed in Table 6-7. The numbers of cattle and calves, hogs and pigs, and broilers increased in the study area from 1950 to 1969. Numbers of the other types of livestock and poultry decreased. Broiler numbers increased 160 percent; the number of milk cows, sheep and lambs, and horses and mules decreased 50 percent or more. The number of cattle and calves in the State of Delaware decreased 33 percent from 1950 to 1969. This decrease was more than offset by a 58 percent increase in the Virginia subarea. The Virginia increase resulted from an increase in pasture farming which allowed farm operators to hold fulltime, off-farm jobs. The number of milk cows decreased substantially in each subarea; there was a 52 percent decline in the study area as a whole. The number of hogs and pigs doubled in Delaware from 1950 to 1969 and it increased in Maryland and Virginia, for a combined 58 percent increase for the study area. The sheep and lamb popu- lation diminished by 46 and 67 percent in Maryland and Virginia, respectively, accounting for most of the 55 percent decline in the study area. The number of horses and mules decreased significantly in all three subareas, resulting in an overall decrease of 70 percent. Chickens 3 months old and over declined in number in all three states between 1950 and 1969, with the decline somewhat greater in Maryland and Virginia than in Delaware. However, broiler production increased in all three states. The 160 percent increase for the study area was largely the result of increases of 90 and 289 percent in Delaware and Maryland, respectively. Turkey production in the study area decreased 24 percent between 1950 and 1969. Maryland and Virginia production decreased 59 and 96 percent, respectively. Delaware, however, increased its turkey production 170 percent. In 1969 most of the production of all types of livestock and poultry, except broilers and turkeys, occurred in Maryland and Virginia. Most of the production of broilers and turkeys in 1969 occurred in Delaware and Maryland. Appendix 6 18 Table 6-8 shows total livestock and poultry water use for the study area for 1950, 1959, and 1969. Total water used by these categories increased from 3.5 billion gallons in 1950 to 5.3 billion gallons in 1969, a 51 percent increase. Livestock and poultry water use in Delaware increased 88 percent from 19SO to 1969, but only accounted for 18 percent of total livestock and poultry water use in the study area in 1969. Water use in Mary- land increased 59 percent between 19SO and 1969, and accounted for 52 percent of total livestock and poultry water use in the study area in 1969. Water use in Virginia increased 24 percent between 1950 and 1969, and accounted for 30 percent of the total live- stock and poultry water use in 1969. Cattle and calves and milk. cows are easily the largest livestock users of water in rural areas. In 1969, cattle and calves and milk cows used 55 percent of all water used by livestock and poultry. The 3S percent increase between 19SO and 1969 is a result of both increased numbers and increased consumption per head. For milk cows, the 52 percent decline in numbers from 1950 to 1969 was more than offset by a 133 percent increase in annual consumptive use per animal because of more stringent sanitation codes and greater production per milk cow. Total water use by cattle and calves and milk cows increased in both Maryland and Virginia between 1950 and 1969. Total water used by hogs and pigs in the study area increased 67 percent between 1950 and 1969, accounting for 9 percent of all livestock and poultry water use in 1969. Water used by hogs and pigs in Delaware, Maryland, and Virginia increased 98, 37, and 102 percent, respectively, between 1950 and 1969. Water use by sheep and lambs and by horses and mules decreased in the study area and in each of the subareas between 1950 and 1969. Dramatic decreases for both types occurred in Virginia. In 1969, sheep and lambs accounted for only 0.3 percent of total livestock and poultry water use in the study area. Horses and mules accounted for 2 percent. Chickens 3 months old and over increased their water use in each State, and by,94 percent in the study area between 1950 and 1969. The increase in water use resulted solely from increases in per bird consumption probably increased as a result of (1) increased use of confinement between 1950 and 1969, (2) improved breeding, resulting in larger birds and more eggs per bird, (3) increased wastage from more automated watering systems, and (4) increased use of water for sanitation. In 1969, water use by chickens 3 months old and over accounted for 1.5 percent of total water use by livestock and poultry. Water use by broilers increased a dramatic 429 percent.in the Appendix 6 19 study area between 1950 and 1969. Increases of 288, 694, and 179 percent were registered in Delaware, Maryland, and Virginia, respectively, for the same period. Increases resulted from both increased numbers and increased consumptive use per bird. Broil- ers accounted for only 8 percent of total livestock and poultry water use in 1950, but by 1969 this share increased to 28 per- cent. Turkeys accounted for only 0.1 percent of total livestock-and poul- try water use in 1969. Total water use by turkeys in the State of Delaware increased 420 percent between 1950 and 1969. This large rise resulted from a 170 percent increase in turkey numbers and a 95 percent increase in consumptive use per bird. The increase in consumptive use per bird was probably the result of (1) great- er confinement, (2) improved birds through breeding, (3) forced feeding, (4) more wastage from automation, and (5) more water for sanitation. Table 6_6 Livestock and poultry numbers, by state and subarea, 1950, 1959 and 1969. Chesapeake Bay Study : rate and Cattle and calves Milk cows ubarea 19au 1959 1950 ---- -------- Inventory number-------- ---Inventory number - - - - - - -- CHESAPEAKE BAY 292,090 383,768 359,880 245,694 195,471 117.732 DEIAWARH 28,254 26,396 18,996 31,452 23,500 11,957 MARYLAND 145,378 195,546 139,701 120,843 73,570 Study Area I---------- : 54,356 89,281 79,353 57,649 55,071 37,843 2---------- : 41,904 47,155 34,240 47,092 42,683 25,155 3--------- : 11,362 12,762 8,187 9,565 6,084 2,662 4---------- : 29,233 31,867 20,893 18,930 13,941 7,172 5--------- t 8,523 14,481 11,429 6,465 3,G64 738 VIRGINIA 118,458 161,826 186,782 51.128 32,205 Study Area 1---------- 2,044 3,387 2,825 1.651 668 340 2---------- : 52,254 58,844 57,582 27,018 19,448 3---------- : 11,394 10,088 14,930 17,689 7,162 4,605 2,630 4--------- : 18,234 30.550 31,622 12.6D9 9,835 6,939 5---------- : 18,296 26,711 25,408 11'"1 7.050, 4,062 6---------- : 277 1,119 1,515 332 767 360 7---------- : 5,005 7,114 5,983 4,919 3,571 2,038 8---------- : 10,954 19,171 44,158 9,389 5,184 5,728 Appendix 6 20 Table 6-6r Livestock and poultry numbers, by state and subarea, 1950, 1959 and 1969, Chesapeake Bay Study--Continued State and -Hogs and pigs Sheep and lambs subarea 1950 1959 1969 1950 1959 1969 -------- Number sold alive ---------- ----------- Inventory number ---------- CHESAPEAKE BKY 485,927 548,398 765,451 71,865 57,775 J2,379 DELAWARE 40,978 43,328 81,272 2,838 4,349 2,057 @LARYLAND 181,559 185,704 248,714 36,003 26,217 19,409 Study Area I---------- 70,930 60,642 55,106 10,696 10,206 8,004 2---------- 52,540 58,340 63,844 11,564 7,938 6,508 3--------- 24,314 33,093 83,468 5,622 3,369 1,169 4---------- 22,605 18,616 16,923 5,641 3,406 3,155 5---------- 11,170 15,013 29,373 2,480 1,298 573 VIRGINIA 263,390 319,366 435,465 33,024 27,209 10,913 Study Area : 1---------- : 5,973 7,534 13.601 2,832 2,609 790 2---------- : 43,465 25,911 20,462 13.271 7,818 4,209 3---------- : 7,640 6,574 5,809 2,198 2,909 526 4---------- : 37,415 58,389 67,080 3,153 2,612 598 5---------- : 31,118 47,081 72,006 5,103 3,941 1,487 6---------- : 525 1.115 919 74 205 196 7---------- : 20,485 25,769 42,238 2,854 1,095 720 8------- --: 116,769 146,943 213,350 3,539 6,020 2,387 Table 6" 6-Livestock and poultry numbers, by state and subarea, 1950, 1959 and 1969, Chesapeake Bay Study--Continued State and Rorses and mules Chickens - 3 months and over subarea 1950 1959 1969 1950 1959 .1969 ---------- Inventory number ---------- ----------- Inventory number ---------- CHESAPEAKE BAY 89,038 28,513 26,576 5,062,745 3,835,506 3,566,849 DELA14ARE 8,288 3,093 2,687 757,369 725,705 680,278 MARYLAND 38,364 12,246 14,740 2.378,392 1,625,643 1,810,564 Study Area 1---------- : 12,328 5,175 7,355 1,087,477 753,494 765,892 2---------- ; 7,849 2,006 2,412 472,662 331,314 206,209 3--------- : 6,398 1,631 IP023 427,697 254,525 745,098 4---------- : 6,014 2,187 2,891 224,302 105,827 26,538 5---------- : 5,775 1,247 1,059 f66,254 180,483 66,827 VIRGINIA 42,386 13,174 9,149 1,926,985 1,484,158 1,096,007 Study Area 1---------- 3,301 792 190 105,741 67,107 203,899 2---------- 6,484 3,251 3,826 206,316 103,249 38,223 3---------- 2,928 1,006 741 150,042 98,385 28,530 4------ 8,511 3,119 1,646 469,088 408,061 171,300 5---------- 8,784 1,998 895 473,497 313.614 171,650 6---------- 238 96 136 10,161 23,697 15,295 7---------- 1,762 715 722 130,516 135,098 58,465 8---------- 10,378 2,197 993 381,624 334,947 408,645 Appendix 6 21 Table 6 -6 Livestock and poultry numbers, by state and subarea, 1950, 1959, and 1969, Chesapeake Bay Study--Continued State and Broilers Turkeys subarea ___f950- 1959 199,9- __1950 1959 1969 -------- Number sold alive ---------- --------- Number sold alive --------- CHESAPEAKE BAY :105,619,502 161,235,116 274,344.590 513,635 720,461 390.583 DELAWARE 59,304,111 71,214,647 112,850,951 103,903 412,607 280,185 MARYLAND 38,761,316 80,147,532 150,868,311 254,117 181,113 103,590 Study Area I----------- 1,151,091 217,200 160,142 103,783 73,120 46,014 2---------- 9,330,766 13,760,681 27,783,424 57,192 33,470 4,209 3-------- - 27,701,341 65,895,051 122,922,845 41,855 59,706 52.120 4---------- 457,420 224,300 0 23,607 9,070 112 5---------- 120.698 50,300 1,900 27,680 5,747 1,135 VIRGINIA 7,554,075 9,872,937 10,625,328 173,615 126,741 6,808 Study Area I---------- 4,506,916 4,882,870 8,568,931 39,375 1,624 0 2---------- 292,903 66,000 0 33,993 51,697 0 3---------- 148,037 160,000 99 11,750 562 0 4---------- 1,457,976 3.993,250 2,048,597 15,722 19,248 3,815 5---------- 386,273 253,130 2,951 26,183 6,063 993 6---------- 13,388 0 0 136 20 0 7---------- 336,789 140,287 0 8,336 5,142 1,930 8---------- 411,793 377,400 4,750 38,120 42,385 70 Source: census of Agriculture for 1950, 1959 and 1969. Table 6- 7 -Annual livestock and poultry water use, Chesapeake Bay Study Area, 19@0, lq@q and 1969 Type Subarea 19@0 1959 1969 -----Gallons per head Cattle and calves Delaware 3,60 3,6-@O 4,380 Maryland ),650 3,6,50 4,380 1/ Virginia 3,65o 3,650 3,6@0= Milk cows Delawam @,475 9,12@ 12,7752/ Maryland 5,475 10,950 12,775 Virginia 5,475 9,125 12,775 Hogs and pigs Delaware 1,460 1,460 1,460 Maryland 1,460 1 4160 1,46o Virginia 1,460 1:460 1,4.60 Sheep and lambs Delaware 730 730 730 Maz7land 730 730 730 Virginia 730 730 730 Horses and mules Delaware 3,65o 3,650 1,380 Maryland 3,650 3,650 1 38011 Virginia 3,650 3,650 3i:650@ - Gallons per bird- Chickens-3 months Delaware 8.0 [email protected] 22.0 and over Maryland 8.0 [email protected] 22.0 Virginia 8.0 1j.0 22.0 Broilers Delaware 2.7 5.0 @-5 Maryland 2.7 5.0 Virginia 2.7 5.0 5 Turkeys Delaware 9.5 11.0 18.5 Maryland 9-@ 11.0 18.@ Virginia 9-5 11.0 ls.@ 11 This water use rate reflects lower water use rates in western Virginia. The state average was used because of lack of specific evidence for higher rates in the Study area. Z/ The rapid increase in the water use of milk cows was due primarily to greater production per silk cow and to more stringent sanitation codes. Source: Kenneth A. MacKichan, "Estimated Use of Water in the U.S., 19SO- 1955-1960-1965," U.S. Geological Survey Circulars; and Virginia Polytechnic Institute in-house data. Appendix 6 22 Table 6- 8 Annual livestock and poultry water use, by state and subarea, 1950, 1959 and 1969, Chesapeake Bay Study State and Cattle and calves Milk cows subarea 1950 1959 1969 1795-0 1959 1969 -------------------------- Million gallons ------------------------------ CHESAPEAKE BAY 1065.8 1400.8 1439.6 1345.2 2004.2 1503.8 DELAWARE 103.1 96.3 83.2 172.2 214.4 152.8 MARYLAND 530.6 713.9 674.9 765.0 1323.3 939.6 Study Area I---------- 198.5 325.9 347.6 315.7 603.0 483.5 2---------- 152.9 .172.1 149.9 257.9 467.5 321.2 3---------- 41.4 46.5 35.8 52.4 66.6 33.9 4---------- 106.7 116.4 91.5 103.6 152.6 91.6 5---------- 31.1 53.0 50.1 35.4 33.6 9.4 VIRGINIA 432.1 590.6 681.5 408.0 466.5 411.4 Study Area I---------- 7.4 12.3 10.3 9.0 6.1 4.3 2---------- 190.7 214.7 210.2 147.9 177.4 128.9 3---------- 41.6 54.4 64.6 39.1 42.0 33.7 4--------- 66.5 111.5 115.4 69.0 89.7 88.6 5---------- 66.7 97.5 92.5 62.9 64.4 51.8 6---------- 1.0 4.1 5.5 1.8 7.0 4.6 7---------- 18.2 26.0 21.8 26.9 32.6 26.3 8---------- 40.0 70.1 161.2 51.4 47.3 73.2 Table 6- 8- Annual livestock and poultry water use, by state and subarea, 1950, 1959 and 1969, Chesapeake Bay Study--Continued State and Hogs and pigs Sheep and lambs subarea 1950 1959 1969 1950 1959 1959 --------------- ---------- Million gallons -------------------------- CHESAPEARE BAY 298.3 358.7 497.7 33.7 27.9 17.0 DELAWARE 35.9 38.0 71.2 2.1 3.2 1.5 MARYLAND 159.1 162.6 218.0 26.2 19.0 14.2 Study Area 1---------- : 62.2 53.1 48.3 7.7 7.4 5.9 2---------- : 46.0 51.1 56.0 8.5 5.7 4.7 3---------- : 21.3 29.0 73.1 4.1 2.5 0.9 4---------- z 19.8 16.3 14.9 4.1 2.5 2.3 5---------- : 9.8 13.1 25.7 1.8 0.9 0.4 VIRGINIA 103.3 158.1 208.5 5.4 5.7 1.3 Study Area 1---------- 12.2 24.4 47.l 0.4 11 0.0 2---------- 15.4 8.8 3.2 1.2 177 0.2 3---------- 5.2 4.8 4.2 0.6 1.0 0.3 4---------- 4.0 20.0 11.2 0.1 0.1 l/ 5---------- 6.2 11.5 15.3 0.8 0.2 CF72 6---------- 0.5 1.0 0.8 0.1 0.1 0.1 7---------- 12.3 16.7 31.8 1.5 0.5 0.1 8---------- 47.5 70.9 94.9 0.7 2.1 0.4 Appendix 6 23 Table 6- 8 Annual livestock and poultry water use, by state and subarea, 1950, 1959 and 1969, Chesapeake Bay Study--Continued State and Horses and mules Chickens - 3 months and over subarea 1950 T959 -1969 1950 -1959 1969 ------ -------- Million gallons --- - ------------ ---- - --- CHESAPEAKE BAY 337.2 106.2 109.7 40.6 58.1 78.8 DELAWARE 30.2 11.3 11.8 6.1 10.9 14.9 MARYLAND 140.0 44.6 64.4 18.8 24.4 39.8 Study Area 3----------- 45.0 18.8 32.2 8.6 11.4 16.9 2---------- 28.6 7.3 10.5 3.7 5.0 4.5 3-------- -: 23.4 5.9 4.5 3.4 3.8 16.4 4---------- 21.9 8.0 12.6 1.8 1.6 0.6 5---------- 21.1 4.6 4.6 1.3 2.6 1.4 VIRGINIA 167..0 50.3 33.5 15.7 22.8 24.1 Study Area I---------- : 12.1 2.9 0.7 0.8 1.0 4.5 2---------- : 23.7 11.8 14.0 1.6 1.6 0.9 3---------- : 10.7 3.7 2.6 1.3 1.5 0.7 4--- - ----- : 31.0 11.4 6.0 3.6 6.2 3.7 5----- ----: 32.0 7.3 3.2 3.9 4.6 3.7 6---- - ---- 13.2 2.6 0.8 0.5 0.8 0.2 7---------- 6.5 2.6 2.7 1.0 2.0 1.3 8---------- 37.8 8.0 3.5 3.0 5.1 9.1 Table 6@8 Annual livestock and poultry water use@ by state and subarea, 1950. 1959 and 1969, Chesapeake Bay Study--Continued State and Broilers Turkeys subarea 1950 1959 1950 1959 1969 - ------ - --------------- - Million gallons --- - -------- CHESAPEAKE BAY 285.4 806.1 1,508.7 4.6 7.5 6.9 DELAWARE 160.0 356.1 620.6 1.0 4.5 5.2 @IXRYIAND 104.5 400.6 829.8 2.3 1.9 1.7 Study Area 1---------- 3.0 1.0 0.9 0.9 0.8 0.8 2---------- 25.2 68.8 152.9 0.6 0.3 l/ 3--------- 74.8 329.5 676.0 0.4 0.7 679 4---------- 1.2 1.1 0.0 0.2 0.1 5---------- 0.3 0.2 l/ 0.2 l/ VIRGINIA 20.9 49.4 58.3 1.3 1.1 0.0 Study Area 1---------- 12.2 24.4 47.1 D.4 l/ 0.0 2---------- 0.8 0.3 0.0 0.3 D76 0.0 3---------- 0.5 0.8 l/ 0.1 l/ 0.0 4---------- 4.0 20.0 n72 0.1 1/ 5---------- 1.2 1.2 1/ 0.1 fl 4 6---------- Y 0.0 c7o 070 7---------- 1.0 0.7 0.0 8---------- 1.2 2.0 0.3 0.4 1/ tess than 0.1. Appendix 6 24 IRRIGATION WATER USE Irrigation water is the third component of total rural water use. The amount of water used varies greatly from year to year, depend- ing on climatological conditions and cropping patterns. In the Northeastern United States the amount of moisture occurring nat- urally as rainfall greatly influences the amount of supplemental irrigation water needed. Cropping patterns, while not usually subject to significant change, also influence the total amount of irrigation water used. The 1969 Census of Agriculture, for the first time, reported the amount of water used for irrigation on Class 1-5 farms (99.5 percent of all irrigated acres in the study area). From this information the amount of irrigation water applied per acre on Class 1-5 farms was computed. That amount was then multiplied by the total number of irrigated acres to obtain an estimate of the total amount of irrigation water applied (Table 6- 9 ). The same application methodology was used for 1964. This method implicitly assumes that climatological conditions and cropping patterns were similar in 1964 and 1969, which was not the case: in 1964 there were five to ten inches less rainfall in the North- east than in 1969. In spite of these weather conditions, the number of acres irrigated increased 19 percent between 1964 and 1969, from 48,922 acres to 58,314 acres. Maryland showed the greatest change between 1964 and 1969--a 39 percent increase. The total number of irrigated acres was distributed fairly evenly among the three states. Table 6- 10shows the distribution of irrigated acres in 1969 by crop. The major irrigated crops in the study area were field corn (6 percent), other field crops (30 percent), veget@@bles (52 percent), and nursery and other crops (8 percent). Most of the irrigated field corn (54 percent) was in Maryland, while most of the other irrigated field crops (82 percent) were in Delaware and Virginia. Most of the irrigated vegetable production (79 percent) was in Delaware and Maryland, and most of the nursery and other crop irrigation (60 percent) was in Virginia. The land irrigated in 1969 constituted only a small share (2.7 percent) of the total number of irTigable acres in the study Department of Agriculture. 'In that estimation, (see Table 6-11) the total shown for each subarea was classified into acres potenti- ally irrigable without additional treatment measures and acres potentially irrigable but requiring additional treatment-measures. Appendix 6 25 SCS developed the data by summing 90 percent of the Class I crop- land, 75 percent of the Class 2 cropland, 50 percent of the Class 3 cropland, and 25 percent of the Class 4 cropland from 1967 Conserva- tion Needs Inventory reports. (5) Over two million acres in the study area are classified as poten@ tially irrigable. Two-thirds of this area (65 percent) would require additional---treatment measures, such as land leveling or drainage. In both Maryland and Virginia, over 300,000 acres could be irrigated without additional treatment measures. Water use rates in 1969 varied from 4.3 inches in Maryland Subarea 3, to 17.8 inches in Virginia Subarea 6. The latter, however, had an insignificant amount of irrigated land (30 acres). Among the subareas with large amounts of irrigated land, the normal application rate ranged from 3.5 to 5.5 inches, and the average rate for the study area was reputed to be 5.1 inches. The rates for Delaware, Maryland, and Virginia were 4.4, 5.4, and 5.5 inches, respectively. With these rates, total irrigation water used in the study area increased from@6,569.7 million gallons in 1964 to 8,022.3 million gallons in 1969. .Table 6-9--Irrigated farms, acres and water used, by state aud subarea, 1964 and 1969, Chesapeake Bay Study All farms 1%4 All farms 1969 State and Acre-f@a-t Acre set subarea Farms Acres water uaed-1/ Farms Acres wat. ;fu..d_2/ CHESAPEAKE BAY 969 48.922 20,157 917 58,314 24,614 DELAWARE 158 17,542 6.522 164 20,421 7,463 M4RYLAND 419 14,307 6,256 491 19,825 8,873 Study Area 1------ -- 108 1,684 1,()09 104 1,195 676 2-------: 67 5,018 2,379 86 9.846 4,805 3------ - - 124 5,817 2,017 1.13 6,214 2,210 4------- -- 47 702 416 78 939 531 5------ - - 73 1,086 435 110 1,631 651 VLRGINIA 392 17,073 7,379 262 18,068 8,278 Study Area 1 103 11,094 4,573 89 11,964 4,932 2------- -- : 14 365 198 14 387 201 3- - - - - --: 3 103 45 2 4 5 4--- - ----- : 196 1,512 670 72 1,285 625 5---------- : 10 370 131 11 309 135 6--- - ---- : 6 38 56 4 33 49 7--- ------ : 38 3,127 1,379 24 3.099 1,352 8---------- : 22 464 327 46 987 979 4@ Appendix 6 26 Table Irrigated farms, acres and water used, by state and subarea, 1964 and 1969, 6- gr Chesapeake Bay Study--Continued Class 1-5 farm 1969 Application rate State and Acre-re-at Water used-3' per acre subarea Farms Acres water used 1964 1969 1969 --Million gallons-- --Ac. CHESAFEAKR BAY 3 864 57,988 24,419 6,569.7 8,021.8 5.1 DELAWARE 154 20,385 7.452 2,125.6 2,432.3 4.4 MARYLAND 457 19,640 8,778 2,038.8 2,891.6 5.4 Study Area ---------- 90 1,098 628 328.8 220.4 6.9 82 9,836 4,800 775.4 1,565.8 5.9 3--------- 110 6,198 2,204 657.3 720.2 4.3 4-------- 68 $80 496 135.5 173.1 6.8 107 1,628 650 141.8 212.1 4.8 VIRGINIA 253 17.963 8,189 2,405.3 2,697.9 5.5 Study Area 1--------- 88 11.946 4,925 1,490.4 1,607.3 4.9 14 387 201 64.6 65.6 6.2 3---------- 2 4 5 14.7 1.6 15.0 4- - - - - -- 69 2.261 613 218.3 203.6 5.8 5---------- 11 309 135 42.8 44.1 5.2 6---------- 4 33 49 18.3 16.0 17.8 7--------- 22 3.087 1,347 449.4 440.6 5.2 8--------- 43 936 914 ID6.8 319.1 11.7 I/ Obtained by the following formula: Acre-foot water used: @l f:= : 11@14 A res 11 f= - 1964 Acre-foot water 11 f 969 Ago.. !11 f - 1%9 used 969 2/ Obtained by the following formula: A:re:faet or used . all farms - 1969 Acres, an farm - 1969 A re feet nt tar used, Class 1-5 farms - 1969 Acres, Class 1-5 farms - 1969 3/ One acre-foot water - 325,900 gallons. Table 6-1 OErrigated acres by crop, by state and subarea, 1%9, Chesapeake Bay Study All other Nursery: State and :Cropland: Field 9=11 field Orch- and subarea :pasture corn Sorghum 1trains crops Silage tables t Berries ard other Tot.,-]L/ - - - ------ - - -- - ----- - -- - ---------- - ---- - CHESAPEAU MY 484 3,701 174 761 18.149 2" 31,811 487 310 4,899 61,075 DELAWARE 6 807 20 205 7.362 38 12,289 39 182 134 21,082 MARYLAND 361 2,010 20 367 3.319 204 12,814 227 ni 1,853 21,286 Study Area 59 138 0 6 203 106 400 6 34 132 1,084 2---- 153 1,393 20 281 488 34 7,264 IS. 42 1,253 10,933 3------ - - 37 469 0 0 778 3 5,060 184 0 259 6,792 4---__: 101 20 0 6 400 49 67 17 6 203 869 5- - - - - - 11 0 0 74 1,450 10 23 5 29 6 1,608 VIRGINIA 117 884 134 189 7,468 57 6,708 221 17 2,912 18,707 Study Area t 1---- - ----2 2 0 0 0 6.506 0 6,014 167 10 191 12,910 2-----,. 0 0 0 22 0 46 3 2 7 28 10& 3----t 0 1 0 0 0 0 0 0 0 3 4 4-----. 48 600 100 10 342 5 173 0 0 27 1,305 0 50 34 0 0 6 13 10 0 200 313 0 0 0 0 0 0 0 0 0 32 32 7--- --: 55 72 0 97 316 0 137 22 0 2,405 3,104 8------ -: 12 161 0 60 304 0 368 0 0 26 931 Source: 1969 Census of Agriculture 1/ This.total differs from the totals in Table 6-13, because of irrigation on acres not classified by the Census as being "in farms." Appendix 6. 27 Table 6- 1 lTotal potentially irrigable land, with and without treatment, by state and subarea, 1969, Chesapeake Bay Study Potentially irrijable land State and With Without subarea Total treatment treatmentl/ -Acres--- CHESAPEAXE BAY 2,076,616 1,353.886 722,730 DELAWARE 351,003 274,620 76,383 MARYLAND 877,134 575,380 301,754 Study Area I---------- 187,137 115,993 71,144 2- -- - -- - - 363,980 221,351 142,629 192,%4 145,939 47,025 4------ - -- 59,682 36,226 23,456 5-------: 73,371 55,871 17,500 VIRGINIA 840,479 503,886 344,593 Study Area : 1---------- : 90,224 47.059 43,165 2--------- : 70,358 42.849 27,509 3--------- : 41,142 24.163 16,979 4--------- : 122,148 74,491 47,657 5--------- : 212, "0 131,426 81,034 6---------- : 1,497 867 630 7- ----- 69,616 42,516 27,100 241,034 140,515 100,519 l/ Does not include acres of land presently irrigated. Source; Soil Conservation Service, USDA. TOTAL WATER USE The rural domestic population is by far the largest rural water user in the study area,as shown in Table 6-12. In 1970, rural domestic water use was five times that of livestock and poultry in 1969, and nearly four times that of irrigation in 1969. Rural domestic use is also the fastest increasing component; its use nearly doubled from 1950 to 1970. This in part resulted from the increasing exodus of suburbanites to the country: as agricultu ral land is developed for nonagricultural uses, there may be fewer numbers of livestock and poultry, and possibly fewer potentially irrigable acres available for agricultural use. Livestock and poultry use of water appears to be leveling off. It increased 38 percent from 1950 to 1959, but only 9 percent from 1959 to 1960. Most types of livestock and poultry are declining in number. Water use rates per head or bird are not likely to increase significantly, indicating a leveling off and possibly a decrease in livestock and poultry water use. Appendix 6 28 Irrigation water use has increased, mostly due to the increase in the number of irrigated acres. It is difficult to draw any further conclusions because of (1) the lack of historical data describing irrigation in the Northeast, and (2) variations in rainfall and its effect on supplemental irrigation. Total -rural water-consumption in the Chesapeake Bay Study Area in 1964, using the 1970 domestic consumption data was 36,340.8 million gallons (see Table 6-13). The State of Maryland accounted for 17,454.4 million gallons, or 48 percent of the study area total. Virginia accounted for 12,646.6 million gallons, (35 percent of the total), and Delaware for 6,239.8 million gallons (17 percent of the total). Table 6- l3also compares the distribution of rural water use in the Chesapeake Bay with the distribution of rural population and land area. Total water use in Delaware accounted for more of the Chesapeake total than either its rural population or its land area. In Maryland total water use accounted for almost as much of the Chesapeake total as its rural population, and more of the total than its land area. Rural water use in Virginia, on the other hand, accounted for less of the total than either its rural population or its land area. Table6-12 Water use by type of use, by state and subarea, reported years, Chesapeake Bay Study State and Domestic use : Livestock and poultry use Irrigation use subarea 1950 1960 1970 1930 1959 1969 1964 1969 -- - - - - -- - ------------ - ------ - -Million gallons - - - - -------------- - ---------------- CHESAPEAKE BAY 12,116.3 20,189.3 22,977.5 3,544.4 4,903.6 5,341.5 6,50.7 8,022.3 DELAWARE 1,353.9 2,278.8 2,846.3 510.6 734.7 961.2 2,125.6 2,432.8 11ARYLAND 6,323.8 10,038.4 11,780.4 1,746.3 2,691.3 2,782.4 2,038.8 2,891.6 Study Area 1---------- : 3,046.9 4,851.3 5,462.2 641.6 1,021.4 936.1 328.8 220.4 2---------- : 828.2 1,441.6 1,675.8 523.4 778.8 699.7 775.4 1,565.8 3--------- : 665.9 1,061.0 1,325.8 221.2 484.5 841.5 657.3 720.2 4--------- : 1.145.8 1,602.7 1,823.0 259.3 298.6 213.5 135.5 173.1 637.0 1,081.8 1,493.6 101.0 108.0 91.6 141.8 212.1 VIRGINIA 4,438.6 7,872.1 8,350.8 1,287.3 1,477.6 1,597.9 2.405.3 2,697.9 Study Area I---------- 367.4 501.9 529.1 49.1 55.2 79.4 1,490.4 1,607.3 2---------- 871.9 1,793.3 1,868.3 412.9 434.8 375.0 64.6 65.6 3---------- z 269.2 481.3 753.,6 101.6 110.4 107.1 14.7 1.6 4---------- 1,019.9 1.982.8 1,945.9 209.2 291.8 284.0 218.3 203.6 5---------- 572.5 873.8 1,017.2 197.9 219.0 215.4 42.8 44.1 6---------- 121.4 237.8 436.3 4.4 13.0 11.8 18.3 16.0 7---------- 555.2 793.9 184.7 73.6 87.3 89.6 449.4 440.6 a--------- 661.1 1,207.3 1,616.7 '238.6 266.1 435.6 106.8 319.1 Appendix 6 29 Table6@1-3 Percentage of water use. by type and comparison with population and land area, by state and subarea, 1969-1970, Chesapeake Bay Study Total Die tributiog of water use Distribution of State and water use Total Domestic Livestock Irrigation Rural pop. Land area Aubarea 1969-1970 1969-1970 1970 1969 1969 1970 1970 Mil. gal. - - ----- CHESAPEAKE BAY 36,340.8 100.00 100.00 100.00 100.00 100.00 100.00 DELAWARE 6,239.8 17.16 12.39 17.99 30.25 10.53 10.00 MARYLAND 17,454.4 48.01 51.27 52.10 35.95 50.71 38.35 Study Area 1---------- : 6,618.7 37.93 46.38 33.65 7.62 44.30 28.69 2--------- : 3,941.3 22.58 14.22 25.15 54.14 14." 21.04 3--------- : 2,887.5 16.54 11.25 30.24 24.90 12.69 23.58 4--------- : 2,209.6 12.66 15.47 7.67 5.98 14.59 12.89 5---------- : 1,797.3 10.29 12.69 3.29 7.34 13.44 13.90 'IRGINTA 12,646.6 34.83 36.34 29.91 33.80 38.76 51.65 Study Area : I---------- : 2,214.8 17.51 6.32 4.97 59.14 7.72 6.80 2---------- : 2,308.9 18.27 22.40 23.47 2.41 19.90 12.30 3---------- : 862.3 6.82 9.02 6.70 D6 8.72 8.38 4--------- : 2,433.5 19.26 23.30 17.77 7.50 21.71 19.00 5---------- : 1,276.7 10.09 12.17 12.66 1.38 16.43 23.87 6---------- : 464.1 3.67 5.22 0.74 0.59 4.52 1.20 7---------- : 714.9 5.64 2.21 5.61 16.21 2.20 5.85 ------ 2,371.4 18.74 19.36 27.26 11.74 21.16 21.50 Subarea percentages are computed relative to state study area totals, and state study area percentages are computed relative to the Chesapeake Bay Study Area total. Appendix 6 30 CHAPTER III FUTURE AGRICULTURAL WATER SUPPLY NEE DS FUTURE DEMANDS The demand analysis is broken into subsections, the first of which lists assumptions of a general nature and the methodology applied to all agricultural projections. Each of the following three subsec- tions pertain to a specific aspect of agricultural water demand: domestic, livestock, or irrigation. Methodology and assumptions particular to each are explained, and the demands are analyzed. The demand projections are separated from the text, and given in Attach- ment C at the end of the Appendix. GENERAL ASSUMPTIONS AND METHODOLOGY The location of agricultural production is influenced by a variety Of factors, each of which must be taken into account in the p-rojec- tion of future activity. On the demand side, projected national markets have been increasingly important with technological advances in food processing. Transportation, population, and income estimates must also be included. On the supply side, Production capacity changes with both availability of resources and technological prac- tices. To take these factors explicitly into account one would have to employ a relatively elaborate econometric model which specifies each of the causal variables leading to a shift in agricultural production A" pendix 6 F 31 toward one area over the others. The econometric approach to agri- cultural projections will no doubt be increasingly refined as the period for which appropriate measures are available lengthens and more accurate causal relations are ascertained. At the present time, however, this approach is severely limited by the paucity of relevant data and information on factors which explicitly lead to changes in the distribution of output. Even after potentially causal factors are specified most econometric forecasting models include as an independent variable the production values from previous time periods, based on the usually high correla- tion of production values across time. Because of fixed investments, economic activity will rarely show a radical change from one period to the next; and many of the factors which lead to comparative fill advantage for an area at one time period are likely to be present in another. In agriculture this is especially true where the physical characteristics of soils, climate, and topography seldom change from one period to the next. Thus at the core of the method of projection used in this report is the relation of a subarea's production in one time period to its pro- duction in past periods; and the response of the subarea's agriculture production to change in projected demands. Both of these elements are present in a form of regional analysis called "shift-share" analysis. A modified form of shift-share analysis is employed in the projections in this Appendix. SHIFT-SHARE ANALYSIS In shift-share analysis it is assumed that the change in a subarea's production from one time period to the next varies directly with the projected change in the state's production during that period. (This assumption is particularly pertinent in the projection of agricultur- al production, where the state's market is of great importance in the determination of subarea production levels). The change in production at the state level-, in turn, is assumed to be distributed among sub- areas so that each reflects the change in production over the previous period. In addition to the state shift is aldistributional shift", or the shift in production whereby a subarea's share of its State's produc- tion changes relative to that of other subareas. Again this assump- tion is pertinent to agriculture in that many of the factors which give one Subarea a comparative advantage over others - soil condi- tions, climate, and topography - may be expected to continue from one period to the next, and are reflected in a shift in production toward that region. -Appendix 6 32 The change in a Subarea's production is thus accounted for by state changes in production and the shifts in the distribution of State production among its Subareas. Each of these effects is taken into account when, by the method used in this Appendix, a Subarea's share of State production is pro- jected and applied to target date estimates of state total�. State- level production changes are allocated among the subareas in propor- tion to their projected shares. Subarea share changes, in turn, take into account the distribution shifts in production among the subareas. (This prozedure is hereafter referred to as a "shares analysis." See Attachment A for graphical illustration). A curvilinear projection of the subarea shares was found to be appropriate in the projection of agricultural activity. If a Sub- area's share increased rapidly in the historical period, it was assumed that such increases would not be sustained through the tar- get dates, and they would gradually be toned down. Similarly, if a Subarea's historical shares of State production showed rapid decreases in the historical period, it was assumed the decreases would not be sustained through the target dates. A projection function which was well suited to these characteristics of agricultural production is the "Spillman" function. For rising subarea shares, the Spillman sets limits by means of a linear regres- sion (6); and it estimated target date shares to approach these limits in a curvilinear fashion., thus registering less rapid increases with time. For a falling trend, the shares were assumed always to remain positive, and zero was set as a limit, with the share approach- ing it again in a curvilinear fashion to register less rapid decreases with time. The state totals which were allocated among the subareas in this analysis were provided by OBERS. Since they were an import- ant part of the projection procedure, it is desirable to go in some depth into the assumptions which underline the OBERS state-level projections. OBERS ASSUMPTIONS The OBERS projections are the output of a program of economic measure- ment, analysis and projection conducted by the Bureau of Economic Analysis and the Economic Research Service. The program is run under cooperative agreement with the Water Resources Council, and it has been an integral part of the comprehensive water resources planning program and national assessments of water and related land resources. Appendix 6 33 The objectives of the OBERS program, as listed in its manual, ( 7) are the development of 1) a regional information system with provi- sions for rapid data retrieval 2) near term (1980) mid-term (2000) and long term (2020) projections of population, economic activity and land use and 3) analytical systems for use in water resources and other public investment planning. There are two levels of assumptions in the OBERS projections which are relevant to this report: those of a general nature underlying all OBERS economic projections, and those specific to the projection of agricultural production. The general assumptions are those pertaining to the economic activity. They include the following, which, being fairly straight-forward, are reproduced in their entirety: a. Growth of population will be conditioned by a decline of fertility rates from those of the 1962-1965 period. This is true of both Series C and E projections. Series C projections are used in this Appendix. b. Nationally, reasonably full employment, represented by a 4 percent unemployment rate, will prevail at the points for which pro- jections are made. As in the past, unemployment will be disproportion- ately distributed regionally, but the extent of the disproportionality will diminish. c. No foreign conflicts are assumed to occur at the projection dates. d. Continued technological progress and capital accumulation will support a growth in private output per manhour of 3 percent annually. e. The new products that will appear will be accommodated within the existing industrial classification system, and, therefore, no new industrial classifications are necessary. f. Growth in output can be achieved without ecological disaster or serious deterioration, although diversion of resources for pollu- tion control will cause changes in the industrial mix of output. The following are assumed for the state economic projections: a. Most factors that have influenced historical shifts in region- al "export" industry location will continue into the future with vary- ing degrees of intensity. Appendix 6 34 b. Trends toward economic area self-sufficiency in local-service industries will continue. c. Workers will migrate to areas of economic opportunities and away from slow growth or declining areas. d. Regional earnings per worker and income per capita will con- tinue to converge toward the national average. e. Regional employment/population ratios will tend to move toward the national ratio. ( 8) In addition to this general class of underlying assumptions, there is a set of assumptions which are specific to agricultural pro- Jections. Based on the Series C projections of population and per capita income projections, per capita consumption of agricultural products were estimated as follows: 1963-65 1968-70 Av. Av. 1980 2000 2020 --------------- Pounds --------------------- Beef and veal 103 115 130 135 140 Poultry 39 47 59 63 65 Dairy products 627 570 475 450 425 Citrus fruit 66 88 110 118 120 Non-citrus fruit 102 101 99 92 86 Potatoes 110 117 110 110 110 Wheat 158 153 ISO 141 134 Total 1205 1191 1133 1109 1080 Source: OBERS projections, Vol. 1 (1972). These figures take into account a rising trend of prices of livestock products relative to those of field crops, but the demands for agri- cultural products are projected under the assumption that the price of agricultural products relative to all other consumer products "will not be materially altered." There are assumed to be no shortages. (9) Appendix 6 35 In addition to food demands for agricultural products, there are assumed to exist several nonfood uses of crops, which are incorpora- ted into the OBERS projections. The livestock and poultry populations are assumed to exert a significant demand on feed grains, protein feeds, and roughage, the extent of which depends upon feed utilization per unit of livestock output. Feed utilization in 1980 is assumed to be consistent with current practices and performances. From 1980 to 2020, however, feed utilization is assumed to decline by ten percent, as more efficient use of feed concentrates, expanded use of sub- stitutes for concentrated food sources, and improvements in manage- ment and breeding take effect. Other domestic nonfood uses of crops are in manufacturing and seed production. The rate of change between the i959-61 average and the 1980 level was utilized in making the 2000 and 2020 projections of the other nonfood uses of feed grains. Nonfood uses of vegetables, potatoes, and noncitrus fruit were projected to change at the same rate as their respective food uses; and projected changes for other agricultural products were based on extensions of historical data. A final component of the projected agricultural demands is net exports. Underlying the OBERS projections in this area is the assumption that beyond 1980 U.S. exports will, despite their con- tinued increases, represent a smaller share of total U. S. produc- tion. No attempt was made to predict changes in national trade and food aid policies. The export projections are considered an inter- pretation of the policies as they existed when the projections were made. In sum, the OBERS agriculture projection incorporates several under- lying assumptions pertaining to all economic activity. From projec- tions of gross national product and population use aye derived per capita and total domestic food consumption; the livestock require- ments, in turn, exert a further demand on crop production, as do the projected nonfood uses and exports. The procedure is schematically represented in the OBERS documentation, and it is reproduced here in a summary reference (Figure 6-4). Appendix 6 36 Figure 6-4 Projected National Framework of Production Requirements Projected Gross National Projected Projected Product Population Employment Projected Projected Personal Feeding Income Efficiencies Projected Per Projected Projected Capita Consump- Food Livestock tion Requirements Requirements Projected Non-Food Uses Projected Net Exports Projected Feed, Non-feed, Food, and Livestock Requirements Source: Water Resources Council 1972, OBERS Projections Volume 1, "Concepts, Methodology and Summary Data." Appendix 6 37 DOMESTIC WATER DEMANDS ASSUMPTIONS AND METHODOLOGY A substantial demand for water in rural area is expected to be exerted by the rural population. Some of it will be satisfied by central water systems, which are addressed in Appendix 5 - Municipal and Industrial Water Supply. In this Appendix, water demands are estima- ted for the remainder of the rural population, or the "residual" popu- lation: the population not served by central water supply systems. The residual, in turn, is divided into its farm and nonfarm components. a. Farm water demand. The farm population was projected as a zfunction of historical land in farms, number of farms, and average per farm population. These factors were selected as measures which most directly affect the farm population. First, state-level projections of land in farms were allocated among the subareas by a shares analysis, taking into account the distribu- tional shifts among the subareas. These estimates of land in farms were then combined with projections of a second factor, average farm size, to estimate the number of farms in each subarea at the target dates. Finally, the average per farm population in each subarea was projected (10) and applied to the.projected subarea number of farms, yielding estimates of farm population. The estimates obtained by this method--incorporating projections of land in farms, average size farm, and persons per farm-- were commensurate with past trends in farm population. In the determination of farm water use rates, a major factor is the large scale conversion of farm households to running water systems. There is assumed to be a changing mix of farm households with and with- out running water, with the former consuming substantially larger quantities of water per capita than the latter. The consumption differential is recognized by the United States Geological Survey in. its estimates of use rates for rural households: in Maryland and Virginia, the 1970 use rate was 50 gallons per capita per day (60 gpcd in Delaware), while for farm households without running water the comparable rate was only 10 gpcd. The domestic water demand exerted by farms with running water is thus estimated at five times that exerted by households without running water. A further difference between farm households with running water and those without is that only for the former do water use rates regularly rise (111. Since per capita income has also tended to Appendix 6 38 rise, the increase in water use may be due to the use of income to purchase water using conveniences. This was assumed to be the case in the projection of use rates for households with running water: that as per capita income rises during the target period (see Appendix 3, Economic and Social Profile), there will also be a rise in per capita water consumption. The water use rates of households with running water were therefore simulated by a function which grew over time. To take into account the satisfaction of demand for conveniences, though, the rate of growth was assumed to diminish over time, leading to a leveling off of the water use rate as its absolute size increases. (12) (See Table 6-14). The use rate for households without running water was held constant at 1970 levels (10 gpcd). Table 6-14. Running water use rates, farm population 1970 1980 2000 2020 - - - - - gals. per capita per day - - - Delaware 60 69 86 103 Md., Va. 50 60 77 94 The overall farm water use rate in a subarea was estimated for the target period by projecting from census data the proportion of farm households with and without running water. The farm water use rate varied between the projected rates of farms with and without running water according to this proportion. b. Domestic nonfarm water demand. The domestic nonfarm water use refe d to in this section pertaii@s to the population not served by central supply systems or the "residual" population. The population served by central supply systems was projected in Appendix 5 by breaking it into two components: the population served by large systems (serving more than 2500 persons) and that served by small systems (serving less than 2500 persons). The former was estimated individually in each subarea and for each large system, the latter as a function of total county population. (13) 4 The remainder of the population was the residual. The nonfarm re- sidual population was estimated,under the assumption that the farm population is not served by central supply systems,by subtracting the projected farm population from the total residual. (See Figure Appendix 6 39 P'gure 6-.,, Water S Supply ervice -'n 19 70. Se System, I POPulat- .rVed). Ches'. and Residual p'on Served by Centr I apeake Bay Stud OPUla Moll.-Farm Y Ar ea.tion (Independeantly dePendently Central Wt Farm ed Smaj I Sys @er SIPP,.Y, rem- 2500 Populat toll Persons) 5 7 2 9z _N'Ro, I. . . . . . . . . . . . .... . .... ...... .... 8 . . . . . . . . . . . . . . . . . . . . . Ce Rrr e SuPP.Ly r Ste N. @.R, 'Duo . . . . . . . . Person.) ...... . . . . . .II... g.: gj@L. . _o. Total populat,on 7 423,210 I@esiduaj Undepend POPulatj ently 012 Served) Populat. Centraij-on Served by s4pply systems APpendil 6 40 Nonfarm residual users of water are assumed to consume more per capita than farmers but less than the population served by small water supply systems. In subareas in which farm households dominated the residual, it was assumed that nonfarm residual use rate would approach the farm rate. Conversely, in subareas with relatively few farms, the nonfarm residual population was assumed to have income and demographic characteristics similar to the population served by small central supply systems and its water use rate would accordingly approach the small systems users' rate. (14) (See Table 6-15). Table 6-15. Small system water use rate (20) 1970 1980 2000 2020 - - - - - - - gpcd - - - - - - - 85 93 109 125 The water use rate for the nonfarm residual was therefore estimated to vary between the farm and small system use rates in direct propor- tion to the percent of the total residual represented by nonfarm component. Where the nonfarm component was largest, its water use rate approximated most closely that attributed to small systems, and .where it was smallest, its use rate approximated that attributed to the farm population. PROJECTED DEMANDS a. Delaware. Only Sussex County was considered in projections of domestic water demand. In 1970, water use of the residual popula- tion totaled 1.73 billion gallons. By 1980, the annual rate of con- sumption is expected to jump to 2.18 billion gallons; by the year 2000, use is expected to total 2.83 billion gallons, and by 2020,the annual consumption rate is expected to rise again to 3.19 billion gallons. Compared with the 1970 total figure, these estimates represent increases of 25 percent for 1980, 63 percent in 2000 and 84 percent by 2020, all substantially greater increases than those projected for the study area as a whole. As in each of the subareas, the farm population in Sussex County is projected to diminish during the target period: from 5.,570 in 1970 to 4,930 in 1980, and to SiSOO by the year 2020. The decreases represent, however, a much less steep rate of change than the average for the Chesapeake Study Area. This reflects the OBERS projection that land in farms in Delaware, in contrast to the rest of the 9tudy area, will Appendix 6 41 diminish only slightly, and the expectation that Sussex' share of state land in farms will increase. As the running water use rate reported for Delaware by the U@ited States Geological Survey for 1970 was.somewhat larger than that of the other States in the study area, farm water use rates are somewhat higher in Sussex than in other subareas. Domestic farm water use is projected to rise from 120 million gallons in 1980 to 131 million gallons by 2020. The nonfarm residual population in Sussex county is projected to rise from the 1970 total of 54,000 to 62,000 in 1980, and to 68,900 in the year 2020. That these increases do not fully reflect the pro- jected rise in population in Sussex during the target period indicates that conversion to central water systems is expected as incomesrise. Following 2000, such conversions outstrip the population increases, and the residual population is projected to fall to 67,800. The water use of the nonfarm residual is expected to rise from 2.06 billion gallons in 1980 to 3.06 billion gallons by 2020. (See Figure 6-6) Figure 6-6 - Residual water demand in Delaware: projections to 1980, 2000 and 2020. 3500 - 2625 It NN N - q. 15 11 11, 11 It r1illion It It eallons 1 .0 75 It 8-475 non-farm residual =,a*#\\ It * I - - .* - -Z - . N,11 It It** .... ... . . tarm 100 19,80 2060 2020 Source: Attachment C, Tables 6-C-2 and 6-C-3. Appendix 6 42 b. Maryland. The total population in the Maryland portion of the study area is projected to rise from its 1970 total of 2.7 million to 6.8 million in the year 2020, a rise of 150 percent. During the same period the residual population is projected to decline from the 1970 total of 418,000 to 357,000. This drop would indicate that most of the population growth will occur in areas which will be served by central water supply systems. The proportion of the population which is independently served is expected to decline from IS percent in 1970 to slightly more than 5 percent in the year 2020. Residual water use is expected to rise from the 1970 level of 11.6 billion gallons to 15.8 billion gallons in 2020. The farm population in the Maryland Study Area is projected to fall from 51,400 in 1970 to only 19,000 by 2020, and its annual water use to drop during the same period from 831 million gallons to 649 million gallons. Because of the decline in land in farms during the target period -- from 2.2 million acres in 1970 to 1.7 million acres in 2020 and the expected increase in the average farm size, the number of Maryland farms is expected to fall from 13,700 to only 5,600. This is coupled with a slight drop projected for the average size of farm family, from 3.7 persons to 3.4 persons, in the projection of farm population. The farm water use rate is expected to rise from the 1970 figure of 44 per capita gallons per day (gpcd) to 94 gpcd in 2020, an increase attributed to a rise in both the running water use rate and the proportion of households served with running water. Figure 6-7. Residual water demand in Maryland: projections to 1980, 2000, and 2020. 17,500- 13,125- nillion gallons 8,7504 z -f arm res idual non I 4,375- f arm .......... 197n 1980 2000 2020 Source: Attachment C, Tables 6-C-2 and 6-C-3. tI Appendix 6 43 The nonfarm residual population is expected to decline, in the Maryland Study Area, from 367,ooo 1. in 1970 to 338,000 by the year 2020. Outweighing the decline, however, is a projected increase in its water use rate, from 80 gpcd in 1970 to 123 gpcd in 2020 as it is expected to more closely approximate that estimated for small systems users. The estimated annual water use of the nonfarm residual therefore rises from 10.8 billion gallons in 1970 to 15.2 billion gallons in 2020, an increase of 41 percent. (See Figure 6-7) Subarea 1. This subarea, composed of Baltimore and its contiguous counties, had in 1970 the largest residual domestic water use of any of the subareas, 6.20 billion gallons per year. By 1980 the total is expected to increase to 6.21' billion gallons per year, but by the year 2000 the size of the residual is projected to diminish, and its water use, is expected to drop to 5.76 billion gallons. By 2020, the general rise in use rates begins once again to outweigh the popu- lation decrease, and estimated water use rises to 6.70 billion gallons per year. The historical data show a decline in land in farms and an increase in the average size of farms which are somewhat sharper than the average for the study area, and this trend is expected to continue into the target period. In 1970, there were 4,360 farms in Subarea 1. a total which is expected to decrease to 4.300 farms in 1980, and 1,550 farms by the year 2020. The farm population is expected to drop from 18,272 in 1970 to 13,170 in 1980, and to only 5,760 in 2020. Its estimated water demand is 274 million gallons in 1980, and 198 million gallons by 2020. The nonfarm residual population is projected to diminish from 198,000 in 1970 to 181,000 in 1980. The sharpest drop is projected to fall between 1980 and 2000,- when there is projected only 141,000 persons. As the Subarea's population is projected to increase during this time, it, can be inferred that large scale conversion to central systems will occur between these dates. Following 2000, population increases once again predominate, and by 2020 the nonfarm residual population is expected to number 144,000. Its water use,following the population trends.-is projected to fall from 6.00 billion gallons in 1980 to 5.52 billion gallons in 2000, and it rises to 6.50 billion gallons by the year 2020. Subarea 2. In this subarea domestic water consumption by the residu 1 is expected to climb continuously, from 2.00 billion gallons in 1970 to 2.51 billion gallons of annual use by 1980, 2.82 billion gallons by 2000 and 3.04 billion gallons by the end of the target period, in 2020. Again, these increases are substan- tially in excess of those projected for the study area as a whole. Although land in farms in Maryland is projected to fall during the target period, the share of land in farms accounted for by Subarea Appendix 6 44 2 rises to offset the change. In contrast to the rest of the study 6rea, then, land in farms is projected to decline only slightly dur- ing the target period. Thus, though the average farm size in this subarea is largest of any, and it increases to offset the change, the farm population in Subarea 2 is projected to decrease at a slightly more gradual rate than in the study area as a whole. In addition, a high proportion of farm households in Subarea 2 have historically utilized running water, so that, by 1980, over 95 per- cent are expected to have this convenience. Reflecting this trend the farm water use rate for Subarea 2 is somewhat higher than the Chesapeake average. Both the farm population figures and high use rates were considered in the projection of relatively slight declines in farm water use: from the 1970 total of 169.2 million gallons of annual use, it only declines to 165.0 million gallons in 1980 and 148.8 million gallons by the end of the target period. In Subarea 2 the total population is projected to rise at a rate somewhat less than that of the study area as a whole: from the 1970 total of 131,000, the total is projected to rise to only 153,000 in 1980, 198,000 in 2000 and 247,000 in 2020. The size of the residual population in Subarea 2 is not expected to substantially change during the target period, reflecting the projection that conversion to central supply systems will roughly keep pace with the population increase. The residual population is estimated at roughly 65,000 and, the projected increase in the water use - from 2.25 billion gallons in 1980 to 2.84 billion gallons by 2020 - is largely due to the increase in its water use rate. Subarea 3. The largest growth in water use of the residual population is expected to occur in this subarea. From the 1970 residual consumption of 1.44 billion gallons, water use is projected to increase to 1.93 billion gallons in 1980. By the year 2000 annual use is expected to reach 3.03 billion gallons and 4.48 billion gallons is the annual.use projected by 2010. Compared with the 1970 total, this represents a 100 percent increase by 2000 and more than a 200*percent increase by the end of the target period. The farm population in Subarea 3 is not expected to diminish as much as other subareas in the Chesapeake Study Area. This is a reflection of relatively slight decreases in land in farms, and the fact that the average number of persons per farm in Subarea 3, only 2.8 in 1970, is not exDected to fall much lower in the target period. The farm population, 7,700 in 1970, is thus expected to diminish to 6,200 by 1980, and to start to level off at 4,800 in the + year 2000 and 4,100 in 2020. Like others in Maryland a high proportion of farms in Subarea 3 use running water, and the Appendix 6 45 water use rate for farms is and is expected to remain relatively high. Thus despite the estimated reduction in farm population, its water use is expected to rise from 129 million gallons in 1980 to 140 million gallons by 2020. The bulk of the increase in Subarea 3's domestic water use is due to the expected expansion of water consumption by the nonfarm residual population. As in the rest of the study area, much growth in total population is expected in Subarea 3: from the 1970 total of 127,000, the population is expected to almost double to 247,2oo by the year 2020. The nonfarm residual population is ex- pected to grow at an even greater rate than the total population. It is expected to jump from the 1970 total of 45,600 to 96,400 in 2020, and it is projected to represent a rising proportion of the total Subarea 3 population. It can be inferred that a substantial portion of the Subarea's population growth will occur in areas not served by central water supply systems. The water use of the nonfarm residual is expected to grow from 1.80 billion gallons in 1980 to 4.34 billion gallons by 2020. Subarea 4. Subarea 4 is composed of the two Maryland coun- ties which are contiguous to Washington, D.C. Perhaps because of the extensive use of central water supply systems, its residual popula- tion - approximately 5,900 in 1970 and through the target period - is the smallest-of any of the subareas, and its water use reflects this. Only 93.8 million gallons per year were consumed in 1970. The total is expected to jump to 128.0 million gallons in 1980, 194.2 million gallons in 2000, and 244.9 million gallons in 2020. The sharp declines in the domestic water demand of farms is a re- flection of several trends which would tend to diminish the farm population. Both the Maryland total and the Subarea's share of Maryland land in farms are expected to drop during the target period, so that from the 1970 total of 208,000, only 177,000 acres in 1980 and 89,000 acres by the year 2020 are expected to remain in farms. The increase in the average size of farms is greater in Subarea 4 than the Chesapeake average, and the relatively high average number of persons per farm, 4.1 in 1970, is likely to fall rapidly during the target period. Taking these trends into account, the farm population is projected to drop from 6,020 in 1970 to 1,170 by the year 2020. Since the size of the total residual population is not expected to vary from the 5,900 registered in 1970, and since at that time the residual was entirely composed of farm families, the decline projec- ted for the farm population are matched by the appearance of a non- farm residual population in the target period. It may be inferred 4- that in Subarea 4 large areas formerly devoted to agriculture will be developed for nonfarm residential use under independent water supply. Appendix 6 46 The high water use rates of this new nonfarm residual population account for the large increases in domestic water use estimated for Subarea 4. From 1980 to 2020, nonfarm water use is expected to rise from 49 million gallons to 205 million gallons, a fourfold increase. Subarea 5. This subarea is the only one in Maryland for which a decline in residual water use is projected for the target period. From an estimated level of 2.16 billion gallons of annual .3, demand in 1980, the total is expected to decline to 1.87 billion gallons in 2000 and 1.43 billion gallons in the year 2020. The farm population is expected to fall from 9,200 in 1980 to 7,980 in 2000 and to 3,600 by 2020. This projection reflects a trend toward a Subarea decline in land in farms which is sharper than that projected for other subareas, although it is mitigated somewhat by the relatively small average size of farms characteristic of the region. Since only 78 percent of farm families had running water in 2000, the farm water use rate lagged behind that of most other subareas. The difference is expected to narrow during the target period, as many farm households convert to running water systems. Farm water use is projected to decline from 147 million'gallons in 1980 to 123 million gallons in 2020. Most of the decline in water use is expected to occur as a result of a shrinking nonfarm residual. Totaling an estimated 60,700 in 1970 and 1980, the nonfarm residual is expected to drop to 45,000 by the year 2000 and to 29,500 by 2020. Since during the same period, the total population is expected to increase, this decline represents a diminishing proportion of population independ- ently served: from 60 percent of the total population in 1970, the residual is expected to represent only 11 percent by the end of the target period. Most of the Subarea's population growth may be expected to occur in areas served by central water supply systems. In the period from 1980 to 2020, nonfarm residual water use is projected to fall from 1.75 billion gallons to 1.31 billion gallons. c. Virginia. The total population in the Virginia portion of the Study Area is estimated to increase even more than that of Maryland: from the 1970 total of 1.5 million it is expected to reach 4.9 million by 2020. As in the other states, however, the residual population is projected to decline during that period, from 468,000 to 389,000. The estimated proportion of the total population which is independently served thus drops sharply from 31 percent in 1970 (the highest of the three States) to only 8 percent by the end of the target period. Estimated residual water use rises from 13.4 billion gallons in 1970 to 17.4 billion gallons in 2020. Appendix 6 47 The farm population in the Virginia Study Area is expected to diminish, during the target period, by more than 70 percent from 35,800 in 1970 to only 10,300 in 2020. During that period, its annual water demand is also projected to decline, though at a lesser rate, from 530 mil- lion gallons to 354 million gallons. Land in farms in the Virginia Study Area is expected to decline during the target period from 2.1 million acres to 1.3 million acres. Coupled with the characteristi- cally large Virginia farms (the 1970 average was 194 acres), this trend leads to an estimated decrease in the number of farms from 10,900 in 1970 to only 3,000 in 2020. The farm water use rate is expected to rise from the 1970 figure of 41 gallons per capita per day (gpcd) to 93 gpcd in 2020, as the proportion of farm households which are served with running water rises from the 1970 figures of only 77 percent to almost 100 percent in 2020. The projected nonfarm residual population in the Virginia'Study Area declines from 432,500 in 1970 to 378,200 by 2020. Despite the decline its annual water use is expected to increase from 12.9 billion gallons in 1970 to 17.1 billion gallons in 2020. This one-third rise is largely a reflection of the expected increase in the per capita use rate from 82 gpcd in 1970 to 124 gpcd in 2020. That increase, in turn, is attributed to a projected rise in the small-system water use rate, which the nonfarm residual rate is expected to approximate as the number of farm households decreases. (See Figure 6-8) Figure 6-,8- Residual water demand in Virginia: Projections to 1980, 2000 and 2020. 18,000- 0 9,000- non-farm residual I, 4,500- farm 1970 1980 2000 2020 Source: Attachment C, Tables 6-C-2 and 6-C-3. Appendix 6 48 Subarea 1. This subarea.-located on the southern tip of the Delmarva Peninsula, is one of the most rural in the Chesapeake region. The water use of the residual population, 0.98 billion gal- lons in 1970, is expected to rise at a rate somewhat higher than the Study Area average: annual use is expected to jump to 1.17 billion gallons in 1980, 1.33 billion gallons by 2000, and 1.50 by the year 2020. Although Subarea 1 is expected to lose some land in farms to other uses during the target period, its loss is the least of any of the subareas. Its 156,000 acres in farms is projected to remain virtu- ally constant through 1980, diminish only slightly to 153,000 acres in 2000, and only to 145,000 acres by the end of the target period. The increasingly large average size of farms in the Subarea, and a fall in the number of persons per farm are reflected in projections of diminishing population, but the decline is expected to level off after the year 2000. The steepest drop in population is expected be- tween the years 1980 and 2000 - from 1,640 to 1,180 - and the farm popu- lation is expected to level off to just under 1,000 by the year 2020. The farm population in this relatively isolated subarea has histori- cally exhibited the lowest proportion in the Chesapeake of households with running water: only 67 percent of all farm households used runn- ing water in 1970. Although the total is projected to rise to 80 percent by 1980, and over 92 percent by the year 2000, the paucity of running water facilities is reflected in projections of low farm water use rates in the first part of the target period. Estimated domestic use of water on farms is 30 million gallons in 1980, and it rises slightly to 32 million gallons by 2020. Subarea 1 is projected to have the smallest increase in total popula- tion of any subarea: the total of 43,000 persons in 1970 is expected to rise only 17 percent to 51,000 by the end of the target period. During this time the residual population is expected to remain constant, at roughly 34,000. Two points of note emerge from these figures: first, Subarea I has the highest proportion of independently served population of any of the subareas - close to three-quarters were so served in 1970, and the figure is estimated to drop to only 64 percent by the year 2020. Second, the decline in the farm population is expected to be offset by a rise in the nonfarm residual, signaling the development of farmland for residual use. The water use of the nonfarm residual is projected to increase from 1.09 billion gallons in 1980 to 1.46 billion gallons by the end of the target period. Appendix 6 49 Subarea 2. Subarea 2, in contrast to Subarea 1, is a rapidly urbanizing area which touches the District of Columbia to the southwest. It is expected to exhibit one of the largest.growth rates in total water use of any of the subareas: from 2.83 billion gallons of annual use in 1970, the residual population is expected to con- sume 3.56 billion gallons annually by 1980, 4.36 billion gallons by the year 2000, and 4.81 billion gallons by 2020. A large drop in land in farms is projected for Subarea 2: from 315,000 acres in 1970, the total is expected to drop to only 187,000 acres by the end of the target period. In addition, large increase are projected for the size of farms, and the conjunction of these two trends makes likely a large drop in the subarea's number of farms. From the 1,350 farms operating in 1970, only 840 are expected to survive tc.1980; and by the end of the target period, only 320 are estimated to remain in operation. The loss of these farms is the major factor behind the projected reduction in the farm population from 3,590 in 1970 to only 1,070 in the year 2020. Its estimated water use totals 47 million gallons in 1980, and 37 million gallons in the year 2020. The total population of the Subarea is expected to increase more than fourfold, from 603,000 in 1970 to over 2,650,000 by the year 2020. Much of this growth is expected in areas served by central supply systems, but enough is expected to occur in areas characterized by independent water supply that the nonfarm residual is projected to grow, as well. Estimated at 90,800 in 1970, the nonfarm residual is estimated to increase to 109,000 in 2000 before it drops to 105,200 in the year 2020. By that time, only four percent of the Subarea's population will be independently served. The water use of the nonfarm residual is projected to rise from 3.51 billion gallons in 1980 to 4.78 billion gallons in 2020. It is the expected increase in the nonfarm residual population, with its high rate of water consumption, which is the principal factor in Subarea 2's increase in domestic water use. Subarea 3. Water use by the residual population in Subarea 3 is expected to rise in the early part of the target period., and then fall off sharply. In 1970 an estimated 0.98 billion gallons of water were consumed, a total which is expected to rise to 1.23 billion gallons of annual use by 1980, and 1.44 billion gallons by the year 2000. Before the end of the target period, however the total is expected to fall off to only 0.86 billion gallons annual use. Trends which affect the farm population in Subarea 3 almost directly parallel those of Subarea 2. The region is marked by a large decline in land in farms (from 148,000 acres in 1970 to an expected 60,000 acres by the end of the target period). At the same time, the average size of farms in the Subarea, already larger than the average Appendix 6 so for the study area as a whole, is expected to increase rapidly. As a result, the number of farms in Subarea 3 is projected to fall off rapidly from 770 in 1970 to 500 in 1980 and only 150 by the end of the target period. The domestic water use on farms is further reduced in Subarea 3 by the low average number of persons per farm (only 2.2 as recorded in the 1970 Census). It is expected to drop from 27 million gallons in 1980 to only 16 million gallons in 2020. The steep increase in population estimated for Subarea 2 does not carry over into Subarea 3. Though the total population is expected to more than double in the target period, from 49,000 in 1970 to 114,000 by 2020, the rate of increase is substantially less than the Study Area average, and is expected to level off toward the end of the target period. The residual population follows the general population growth early in the target period, but, perhaps reflecting a large scale conver- sion to central water supply systems, it is expected to fall off rapidly toward the end of the target period,from 36,000 to slightly over 19,000. It is this expected falloff in the residual population which is reflected in the downward turn in the subarea's residual water use, as it outweighs even the increases in the per capita water use rates of the residual population. Nonfarm residual water use, projected to rise between 1980 and 2000 from 1,202 to 1,420 million gallons, accordingly is expected to fall c-ff to only*845 million gallons by the year 2020. Subarea 4. Residual water consumption in Subarea 4 of Virginia is expected to increase at a rate above the study area aver- age, although not as great as the rates of increase in Subareas 2 and 3. An estimated 2.41 billion gallons were consumed in 1970, a total which is projected to jump to 3.61 billion gallons by the end of the target period in 2020. Although the Subarea's acreage in farms is expected to fall at a slightly greater rate than the study area average, it is the rapid increase in the average size of farms which is primarily responsible for the-reduction in the subarea's number of farms, and hence its farm population. The farm population, numbering qtP30 in 1970, is expected to fall to only 2,510 by the year 2020. Since only 80 per- cent of the farms in 1970 utilized running water, farm water use rates are somewhat lower than the average. The domestic demand on farms is thus expected to drop from 138.1 million gallons of annual use in 1970 to 85.4 million gallons in the year 2020. Projections of total population rise, in Subarea 4, from the 1970 figure of 322,000 to 428,000 in 1980, and to over 1,000,000 in the Appendix 6 51 year 2020. The rate of increase is somewhat above the rate for the Chesapeake Study Area. Despite the population increases, however, the size of the residual population is expected to remain in the range of 80,000 to 90,000, and exhibit only a slight decline during the target period. The rise in the nonfarm residual water use projected for Subarea 5 is therefore almost entirely due to the expected increases in its per capita use rate. Its estimated water use increases from 2.75 billion gallons in 1980 to 3.53 billion gallons in 2020. Subarea S. Despite the size of Subarea 5, its domestic water use in 1970, at 1.35 billion gallons, was relatively small. By, 1980, however, annual residual consumption is expected to increase by 25 percent, to 1.70 billion gallons, and by the year 2000, is expected to reach 2.09 billion gallons. By the end of the target period resid- ual water use is expected to total 2.35 billion gallons, an increase of 73 percent over the 1970 figure. This increase, at a rate twice that of the study area average, is ex- pected to occur despite the diminution of the farm population. Numbering 6,040 in 1970, this component of the residual is projected to drop to 4,920 by 1980, and to only 2,040 by the end of the-target period. The projected fall in the Subarea's farm population has historically been due to the rapid increase in the average farm size of the Subarea, a trend which is expected to continue into the future. Domestic farm water use is estimated to diminish from 94 million gallons in 1980 to 69 million gallons in the year 2020. The expected growth of the domestic water consumption stems from a projected increase in the size of the nonfarm residual population, which is expected to grow from 43,600 in 1970 to 50,600 in 2020. This portion of the population constituted 53 percent of the total Subarea population in 1970, and it is expected to constitute no less than 37 percent by the end of the target period. Its annual demand, estimated to be 2.06 billion gallons in 1980, is projected to rise to 3.06 billion gallons by the year 2020. Subarea 6. The diminutive size of Subarea 6, on the other hand, is directly reflected in its residual water use - one of the smallest of any subarea - and the total is expected to diminish through the target period. Only an estimated 687 million gallons were consumed in 1970. The total is projected to fall off sharply to 406 million gallons in 1980 and to 198 million gallons by the year 2000. By the year 2020 annual water consumption is expected to rise slightly, to 228 million gallons. The small farm population, only 260 in 1970, is expected to be further reduced, during the target period, to less than 100- The Appendix 6 52 reduction is largely a reflection of the trend toward larger farms in Subarea 6., and the expected decline in acreage in farms - from 10,600 in 1970 to 6,600 by the end of the target period. Almost 99 percent of the total residual population is composed of nonfarm households, but this population, too, is expected to fall off sharply, particularly in the early part of the target period. The residual population was estimated at 22,100 in 1970, but it is projected to decrease by almost half - to 11,900 - by the year 1980, and by half again - to less than 5,000 - by the year 2000. Although the nonfarm residual population is projected to level off at the latter figure, its estimated sharp reduction in the beginning of the target period leads to projection of total water use which also fell off sharply. From 403 million gallons of annual use in 1980, the nonfarm residual is expected to consume only 195 million gallons in 2000, a total which rises but slightly, to 225 million gallons, by the year 2020. The decrease in the size of the residual would reflect conversion of parts of the Subarea to central supply systems, as the total population is expected to almost double - from 33,000 to 63,000 - between 1970 and the end of the target period. While almost 68 percent of the total population was recorded as independently served in 1970, the comparable figure projected for the year 2020 is a mere 8 percent. Subarea 7. Like Subarea 6, Subarea 7 is one of the few subareas Cor which a decline in the total residual water use is expected during the target period. The major decline is projected for the decade between 1970 and the start of the target period in 1980, in which annual consumption is expected to drop from 1.86 billion gallons to 1.19 billion gallons. During the target period the estimated reductions are considerably more gradual, as consump- tion is projected to fall to only 1.07 billion gallons in the year 2000 and 0.92 billion gallons in 2020. Subarea 7 is one of the few in which domestic water consumption on farms is expected to rise during the target period. Although the farm population is projected to decline - from 1,380 in 1970 to 750 by 2020 - the decline is not as steep as the average for the study area. Only a slight decrease in land in farms is expected, from 121,000 acres in 1970 to 109,000 acres in 2020. In addition, the relatively high percentage of farm households with running water - 90 percent,in 1970 - is reflected in the farm water use rate, the highest in the Chesapeake Study Area. Domestic farm water consumption is expected to rise from the 23 million gallons consumed in 1970 to 25 million gallons by 1980, and 26 million gallons by the year 2020. Appendix 6 53 It is the estimated decline in the nonfarm residual population which is reflected in the diminishing total residual water demand, as the nonfarm component consumes 98 percent of the residual water used in Subarea 7. There are two factors prominent in the estimated decline in the residual population between 1970 and 1980: first, a less than average increase projected for the total population and second, a sharply decreased proportion of the population which is expected to be independently served. In that decade, the population of Subarea 7 is projected to increase by only 17 percent, from 261,000 to 306,000 persons. During the same period, the proportion of the population which is independently served is projected to decline- from 23.4 percent to only 11.7 percent. As a result of these trends, the residual is expected to decrease sharply, from 59,800 persons in 1970 to only 34,800 in 1980, and its water use from 1,840 million gallons to 1,170 million gallons. After 1980 the proportion of the population which is independently served is expected to continue to fall rapidly, but the decline is offset by the sharp population growth expected in the Subarea. The fall in the residual population is somewhat moderated, therefore, and its water use is projected to fall only io 894 million gallons by the year 2020. Subarea 8. The residual domestic water demand in Subarea 8 is estimated at 2.33 billion gallons of annual use in 1970. Con- sumption is expected to rise fairly rapidly, in the early part of the target period, to 2.80 billion gallons in 1980 and to 3.21 billion gallons by the year 2000. During the latter part of the target period, however, annual consumption is expected to fall off slightly, to 3.17 billion gallons. The number of farms in Subarea 8 is projected to fall rapidly, from the 3,020farms in operation in 1970 to 2,,070 in 19801 and to only 760 by the year 2020. This is a reflection of the projected decline in the Subarea's share of Virginia land in farms - of 444,000 acres in farmland in 1970, only 245,000 acres is expected.to remain in farms by the end of the target period - and increases in the relatively small average size of farms. The farm population is expected to fall accordingly, from a total of 10,760 in 1970 to V40 in 1980 and to 2.,580in the year 2020, and its water use is expected to diminish from 149 million gallons in 1970 to 87 million gallons in 2020. The nonfarm residual population is expected to increase slightly from 75,400 in 1970 to 81,700 in 1980, and fall to 68,500 by the end of the target period. Though it constituted 61 percent of the total in 1970, the projected decline in that proportion to 35 percent in 2020 more than outweighs the relatively slight increase estimated for the Subarea's total population. The estimated nonfarm residual water demand is 2.67 billion gallons in 1980, 3.10 billion gallons in 2000, and 3.08 billion gallons in 2020, an increase due entirely to pro- jected growth in the water use rate. Appendix 6 54 LIVESTOCK WATER DEMAND ASSUMPTIONS AND METHODOLOGY Livestock consumption and sanitary uses represent a second major de- mand for water in the target years. As in the estimation of irriga- tion water demand, water use was projected by estimating production in each subarea by shares analysis. Livestock water demands were then estimated using livestock number and water use coefficients. In this procedure the shares analysis was modified somewhat to take into account the form of the OBERS state livestock projections, which were in terms of live weight demanded at the market in the target date years. Once state level estimates of live weight at market were allocated among the subareas, it was necessary first, to convert market weight into livestock numbers, and second, to take into account the supportive livestock population. State-level demands for livestock and livestock products were con- verted to livestock numbers by dividing them by a set of average livestock weights and - in the case of chickens and milk cows - productivity. The set of average livestock weights developed for the conversion of production to livestock numbers is given in Table 6-16. While the weights roughly parallel the 1970 market weights for the Chesapeake region, they nonetheless reflect changes in livestock production now underway. The conversion weights for pork and sheep are slightly higher than current levels, taking into account the development of more efficient feeding practices and improved breeds. Similarly, milk and egg production are assumed to increase over current levels, due to improvements in nutrition and management practices permitting performance tests and selective breed- ing. The average weight assumed for turkeys, however, is assumed to be slightly below current levels, due to market preferences for slightly smaller birds. Marketed livestock represent only part of the total livestock popu- lation, and only part of livestock water demands. In support of the marketed livestock are breeding flocks and herds, which exert a sub- stantial demand for water. In addition, not all animals are expected to reach marketable age, and those who do not also exert demand for water. Given the numbers of livestock needed to meet de- mands as projected by OBERS, it was possible to estimate the breed- ing stock through fertility coefficients and mortality numbers through mortality rates. Livestock numbers were thus expanded to include the supportive livestock population. Appendix 6 55 Table 6-16-- Average market weights, livestock and live- stock products, target projection years I/ Product Unit 1980 2000 2020 Hogs pigs lb 230 230 230 Sheep lambs lb 110 110 110 Broilers lb 3.5 3.5 3.5 Turkey lb 15 15 15 Eggs/chicken eggs 240 265 280 Milk/cow lb 10818 12097 12218 11 Weight figures represent weighted averages of young stock and fully grown livestock, derived through examination of historical state data and future projections of average weights. for future average weights, source was Lee A. Christensen, The Economic Base of the Southeast Wiscon-sin Rivers Basin with Emphasis on the Agricultural Sector: reference Report 13, USDA, ERS, 1970. These figures were used when it was demonstrated that in historical livestock weights the gap between the two study areas was rapidly closing, and that by 1970 most were within 5% of each other. The water demands of the estimated livestock population were pro- jected on an annual basis,to take into consideration the differ- ent time periods during which each of the three components exert demand. Breeding stock or flocks were assumed to exert demand for water during the entire year,'while livestock to be marketed only exert demand during the period in which they are raised. Given that mortality had an equal chance of occurrence at any moment dur- ing that time it was assumed that mortality exert demand during roughly half the longevity of marketed animals. Approximate water use coefficients for each of the components of the livestock population were developed, and applied to project the water demands of each component. In practice, it was found most straightforward to combine these coefficients with the fertility and mortality rates and with the livestock weight and productivity parameters, to derive single number and water use coefficients (see Tables 6-17 and 6-18). The latter, when applied to the sub- area demands for livestock and livestock products, yielded estimates of livestock numbers and water use. Appendix 6 56 Table 6-17-- Livestock water use rates: 1980, 2000, and 2020, Chesapeake Bay Study 1980 2000 2020 Livestock Prod-: Water Use Coeffi- : Water use : Period: Coeffi-: Water use : Period: Coeffi-: Water use : Period: ucts Marketed : Component :-cient 1/: coefficient: of use: cient coefficient: of use; cient coefficient: of use; Gallons Days Gallons Days Gallons Days HOGS Marketed animals 1.0 4/day 180 1.0 4/day ISO 1.0 4/day 180 Breeding stock 14.5 4/day 36S 16.0 4/day 365 17.0 4/day 365 Mortality .10 1/day 82 .07 1/day 78 .05 I/day 75 SHEEP Marketed animals 1.0 l.S/day 180 1.0 2/day ISO 1.0 2/day 140 Breeding stock 1.2 2/day 36S 1.25 2/day 365 1.25 2/day 365 Mortality .10 .8/day 90 .07 I/day 75 Os I/day 70 EGGS Laying flock 1.0 26/yr. 1.0 26/yr. 1.0 26/yr. Mortality .08 2.5/day/100 180 .06 3/day/100 180 .05 3/day/lOO 180 BROILERS Marketed birds 1.0 1. 5/yr. 1.0 1.5/yr. 1.0 1.5/yr. TURKEYS Marketed birds 1.0 18/yr. 1.0 18/yr. 1.0 18/yr. Breeding flock 50.0 12/day/100 365 50.0 14/day/100 365 50.0 14/day/100 @S Mortality .08 6/day/100 70 .06 6.5/day/100 62 .05 6.5/day/100 62 MILK Milk cows 1.0 14/day 365 110 14/day 365 1.0 14/daY 365 124/day (for milk) 300 127/day (for milk) 300 28/day (for milk) 300 Calves-3/ -6 12/day 365 .6 12/day 365 .6 12/day 365 Mortality .04 6/day ISO - .03 6/day 180 .03 6/day 180 I/ Coefficients relate (1) numbers of marketed animals, or producing animals, to (21 numbers of breeding flocks or herds, and (3) mortality. Numbers of marketed animals or producing animals are estimated by relating projected demands for livestock products to average weights or productivity. Numbers in breeding flocks or herds are estimated by dividing (1) by the coefficients pertaining to (2). Mortality is estimated by multiplying (1) by the rates listed for (3). I/ Gallons per day per 100 birds. .1/ Dairy calves not sold for beef or veal. Numbers are determined by multiplying number of milk cows by factors listed. Table 6-18. Livestock number and water use coefficients 1980 2000 2020 HOGS number 0.0051 0.0049 0.0048 water use 3.6039 3.5509 3.5201 SHEEP number 0.0176 0.0170 0.0168 water use 8.0503 8.0841 7.8864 CHICKENS number 0.0045 0.0040 0.0038 water use 0.1098 0.0993 0.0938 BROIL13RS umber 0.2857 0.2857 0.2857 water use 0.4286 0.4286 0.4286 TURKEYS number 0.0733 0.0720 0.0713 water use 1.2808 1.2843 1.2816 MILK C9WS number 0.0002 0.0001 0.0001 water use 1.3977 1.3208 1.3144 Applied to estimated demand for live weight at market or livestock product (milk, eggs). Source: Tab les 6-16 and 6-17. Appendix 6 57 Two exceptions to this procedure were the estimation of beef cattle and dairy cow water demand. For beef cattle, the dairy cow popula- tion is expected to contribute salvage, heifers, and veal calves to beef demand , and the feedlot beef population was estimated only after these dairy components were subtracted from the beef demand allocated to each subarea. In addition, backup inventory was estimated in pro- portions consistent with each subarea's historical trend. Dairy cow water use was projected to rise proportionally with the increase in milk output per cow. In the analysis of future livestock water demands, it is evident that per unit livestock water use is almost uniformly lower than the per unit use listed in the U.S. Geological Survey (15), the main source of data for the livestock section of the Existing Conditions Report. The difference in rates is largely attributable to the methodology employed in the projections. The point of departure in the projection of livestock water use was the estimation of market numbers, the portion of the livestock popu- lation which would be required to meet subarea demands. It was assumed that for most livestock (16) the water use rate for this portion.of the population would approximate the average rate for a mature animal, the rates given in the U.S. Geological Survey. From the portion of the livestock population needed to meet demand, however, breeding flocks and mortality numbers were derived, each with explicit reference to the number of days per year they consume water and their consumption rate. The analysis of the livestock population with respect to water consumption was therefore more detailed than a simple measure of inventory or sales, and it was judged that the aggregate nature of the Geological Survey water use rates were no longer appropriate. Yearly per unit use rates were de- veloped as an end product of the analysis of each of the three components of the livestock population required to meet the OBERS estimates of livestock demand. On a more explicit level, several factors can be listed which would tend to depress the annual per unit water use rates for livestock. a., Inclusion of backup herd with lower water use rates. This is the case in the analysis of water demands exerted by milk cows. The back-up herd - including heifers and calves - swelled numbers by an average of 64 percent, yet its average water use rate was estima- ted at only 35 percent that of a milk-producing cow. b. Inclusion of demand numbers with lower water use rates. Measurement of numbers by inventory in some cases excludes demand numbers from the analysis. An inventory of sheep taken on January I (as in the 1969 Census of Agriculture) would not include lamb sales, Appendix 6 58 whose 180-day period of water consumption does not begin until later in the year. Though their use rate approximate those of the backup herd, lambs are assumed to have a shorter life span. Annual water use for this portion of the sheep population is thus cut to a fraction of that of the backup herd, and it depresses the aggregate per unit use rate. c. Inclusion of mortality numbers. Inclusion of mortality numbers has a dual effect on the per unit water use rate aggregated over all components: not only does this component tend to swell the numbers of livestock counted, but, due to the truncated life span of the animals it represents, its annual use rate is below that of the rest of the herd. The use rate over all components is thus diminished by its inclusion. d. Combination of factors. The largest differences in per unit use rates are due to a combination of the above three factors. In the case of beef, the water use of one and two year calves is in- cluded in the annual use of the backup herd, and their relatively low use rates depress the average. In addition, demand numbers include animals, such as veal, who are marketed before maturity and whose consumption over a shortened life cycle sharply reduces the overall annual use of this portion of the herd. Finally, the overall use rate is reduced by the inclusion of mortality numbers, which were assumed to consume water at an annual rate much reduced from that of mature animals. In some cases water use rates were projected to increase, due largely to expected increases in per unit output. This effect is seen, for example, in the per unit rate for chickens. The basic rate is projected to jump from 22 gallons per year to 26 gallons per year in the target period, an increase due to an expected increase in annual egg production per bird. Because of these factors, and the influence of changing average live- stock weights, the numbers and per unit water use between 1970 and the target dates are not comparable. PROJECTED DEMANDS a. Delaware. Though livestock and poultry water demands in Delaware are among the largest in the study area, they are expected to decline from a total of 527 million gallons per year in 1980 to 479 million gallons in 2000 and 460 million gallons in 2020. The major livestock users of water in Delaware are broile rs. The demand for broilers from Delaware is expected to jump from the 1964 total of 415 million pounds (17) to 541 million pounds in 1980 and to 581 million pounds in 2020. Numbers of broilers are expected to rise commensurately. From the 1969 census total of 112 million,, the Appendix 6 59 total number of broilers sold is projected to increase to 154 million in 1980 and to 170 million in 2020. Broilers are expected to consume 232 million gallons of water in 1980, or 44 percent of.all Delaware livestock and poultry water use, a figure which rises to 249 million gallons (52 percent) in 2000 and 255 million gallons (55 percent) in 2020. The second major users of water are milk cows. The demand for milk from Delaware is expected to fall from the 164 total of 165 million pounds to 118 million pounds in 1980, and to 100 million pounds in 2020. In 1980, this part of livestock demands is projected to represent 31 percent of the total in Delaware, a proportion which falls slightly during the rest of the target period. Milk cows are expected to consume 164 million gallons of water in 1980, 144 million gallons in 2000, and 131 million gallons in the year 2020. Hogs and pigs account for the other major use of water among live- stock in Delaware. Their estimated consumption is 50 million gallons, or about ten percent of the total. (see Figure 6-9) Figure 6-9. Livestock water demand in Delaware. Projections to 1980, 2000, and 2020. 600" 1 4 450- million ......... . .......... . gallons broilers . .. ....... a A 150- milk cows S7, - - - - - - - - - - ..... .... . . ............... d ....... ..... ggz 1 70 1980 2000 2020 Source: Attachment C,, Tables 6-C-5 thru 6-C-11. Appendix 6 60 b. Maryland. The total livestock demand in the Maryland portion of the study area is projected to rise slightly from 2.31 billion gallons in 1980 to 2.43 billion gallons in 2020. The major livestock users of water in the Maryland Study Area are milk cows, projec ed to account for 46 percent of the total 1980 water use and 55 percent of the 2020 total. Although the proportion of state production accounted for by the study area is expected to diminish from 50 percent in 1980 to 37 percent in 2020, the decline is outweighed by the projected increase in state-level milk production, from 1.6 billion pounds in 1980 to 2.8 billion pounds in 2020. In addition, per unit consumption is expected to rise due to increased productivity and sanitation needs. Water use by milk cows is therefore projected to increase from 1.07 billion gallons in 1980 to 1.34 billion gallons by 2020. The second major users of water are cattle and calves, projected to account for 770 million gallons in 1980 and 660 million gallons in 2020, or 33 and 27 percent, respectively, of the Maryland Study Area total for livestock in each of those years. The expected decline is attributed to the projected fall in state beef production during the target period, from 111 million pounds in 1980 to 102 million pounds in 2020. The study area's share of state production is expected to remain roughly constant at 70 percent. Broilers are the third major users of water in the Maryland Study Area, with a projected demand of 266 million gallons in 1980 and 307 million gallons in 2020. Broiler production in Maryland is expected to be increasingly concentrated in the study area portion of the State, with 88 percent of the State total in 1980 and almost 95 percent by 2020. Broilers are expected to consistently account for 12 percent of the livestock total in the Maryland Study Area. Hog production in Maryland is also expected to be concentrated in the study area portion of the State, with 9S percent of Maryland hogs in 1980, and almost 100 percent in 2020. Despite this increase., however, state pork production is projected to fall off from 44 million pounds in 1980 to 28 million pounds-in 2020, with the result that estimated hog water use falls off from 150 million gallons to 97 million gallons. (See Figure 6-10 below). Subarea 1. Total livestock and poultry use is projected to increase, in this subarea, from 1.07 billion gallons of annual use in 1980 to 1.18 billion gallons in 2000 and 1.33 billion gallons in 2020. It has by a substantial margin the largest livestock water use of any of the subareas. Easily the largest users of water among livestock and poultry are milk cows. The demand for milk in Maryland is expected to almost double by the end of the target period, and Subarea I is projected Appendix 6 61 Figure 6-10- Livestock water demand in Maryland. Projections to 1980, 2000, and 2020. 2,500- 1- = _#I=_ W; -.4 @_- I . *__ - ---__ -other livestock . - 1,875- V ON ON' '*.@ million milk cows ._O: _N, *7. N I gallons 1, 250- 625 1 cal . . . . . . . . . . . . . . . ... ........... ... . .. .. .......... > -ers A A hS2&s an 12 S 1970 1980 2000 2020 Source: Attachment C, Tables 6-C-5 thru 6-C-11. to hold a constant twenty-five percent share of the total. Water demands by milk cows are estimated to increase from 599 million gal- @lons in 1980 (56 percent of the Subarea total) to 730 million gallons in 2000 (62 percent) and to 893 million gallons (67 percent) by the end of the target year. Most of the remaining livestock water in Subarea 1 is used by cattle and calves. Although the Subarea's share of beef sales is expected to increase from 40 percent in 1969 to close to 50 percent by the end of the target period, such increases are offset by projected declines in Maryland beef production. The net result is that water use by beef is expected to remain constant during the target period, at approximately 430 million gallons annually. Appendix 6 62 Subarea 2. Aggregate water use by livestock and poultry is projected t@; -diminish, during the target period, from 597 million gallons in 1980 to 544 million gallons in 2000 and 513 million gallons in 2020. Once again the major livestock users of water are milk cows. Although the Subarea share of Maryland milk sales is expected to diminish from 18 percent in 1970 to 17 percent in 1980 and to 10 percent by the end of the target period, the large increase in demand at the state level more than balances the distributional losses. The number of milk cows and backup herds is expected to remain constant during the target period at around 40,000 animals, and their water use is pro- jected to be 380 million gallons, or 65 to 75 percent of the Subarea total. Cattle and calves represent the next largest users of water, although they are expected to consume diminishing amounts of water during the target period. The decline is due to a falling share of State beef sales - the 16 percent share in 1969 is expected to fall to 11 per- cent by 2020 - and to the projected decline in beef demand at the state level. Thus the estimated water demand of cattle and calves, 155 million gallons and 26 percent of the Subarea's livestock demands in 1980, is expected to drop to 90 million gallons and 18 percent by the end of the target period. Hogs and pigs are expected to account for a roughly constant propor- tion, eight percent, of Subarea livestock demands. Their water demand is projected to fall from 53 million gallons in 1980 to 36 million gallons in 2020, as the increasing Subarea share of State production is offset by the projected decline in Maryland demand for pork. Subarea 3. In Subarea 31, water use by livestock and poultry is projected to increase slightly during the target period, from 390 million gallons of annual use in 1980 to 412 million gallons in 2000 and 422 million gallons in 2020. The small magnitude of the changes in aggregate demand conceals large shifts in its composition. The major livestock consumers of water in the Subarea are broilers. Broiler production in Maryland is expected to rise sharply during the target period, from 151 million in 1969 to 201 million in 1980, 211 million in 2000, and 215 million in 2020. Further, this production is expected'to be increasingly concentrated in Subarea 3. where the 81 percent share in 1970 is projected to rise to 85 percent in 1980, and to 95 percent by 2020. Water use by broilers is projected to rise from 260 million gallons in 1980 to 306 million gallons by 2020, an increase of eighteen percent and from two-thirds to almost three- quarters of the total. Another increase in water demand is expected for cattle and calves. This is mainly due to projected increases in the Subarea's share Appendix 6 63 of State beef production, from 2.2 percent of beef sales in 1969 to 4.1 percent in 1980 and to 5.5 percent by the end of the target period. The estimated cattle and calf water demand rises from 50 million gallons in 1980 to 61 million gallons by 2020, and it repre- sents roughly thirteen percent of the Subarea's livestock demand throughout the target period. These increases are offset, however, by declines in the water use of hogs and pigs and milk tows. The main factor which contributes to the diminishing water use of hogs is the expected decrease in Mary- land pork production; and a steadily falling Subarea share of Maryland milk production accounts for the diminishing water demand by milk cows. Together the two account for a decline in estimated Subarea water use of 23 million gallons between 1980 and 2020. Subarea 4. Livestock water use is projected to decrease sharply in this subarea, from 180 million gallons annually in 1980 to 120 million gallons in 2000 and 83 million gallons in the year 2020. Most of the decline is accounted for by milk cows and cattle and calves, the major livestock water users in the Subarea. Milk cows represent about half of the Subarea's livestock water use. Although state-level demand for milk is expected to -rise in Maryland during the target period, Subarea 4's share of production is expected to decrease from 5.2 percent in 1969 to 4.0 percent in 1980, and to 1.2 percent in 2020. As the distributional decline far outweighs the prodocution increase projected at the state level, water use in milk production is expected to fall sharply, from 89 million gallons annually in 1980 to only 45 million gallons in 2020. Cattle and calves are expected to account for much of the remaining livestock water use in the Subarea, with approximately 45 percent of the total. As with milk cows, the Subarea's share of the State total beef demand is expected to fall sharply during the target period, from 8.0 percent in 1969 to 6.8 percent in 1980 and to 3.2 percent by 2020. Since the distributional effect is augmented by a projected decline in State demand for beef, cattle and calf water use is expected to fall from 82 million gallons in 1980 to 36 million gallons in 2020, a decline of more than fifty percent. Subarea 5. While a changing mix of water-consuming live- stock is projected for this subarea, the annual livestock water demand is expected to remain constant. In 1980 and 2000, demand is projected to total 77 million gallons, and it is expected to rise only slightly, by the year 2020, to 80 million gallons. Livestock water use in Subarea 5 is among the lowest in the Chesapeake Study Area. The relatively high water use rates of beef cattle and their backup herds lie behind their projection as the major livestock water consum- ers in the Subarea. Though only 4 percent of the Maryland beef demand is expected to be filled by Subarea 5, they account for 60 per- cent of the total estimated livestock water demand. Projected Appendix 6 64 consumption by cattle and calves totals 49 million gallons in 1980, a figure which drops slightly to 47 million gallons by the year 2020. Also declining is the water demand expected to be exerted by hogs and pigs. The major factor in this projection is the expected reduction in demand for Maryland-produced pork during the target period, as the subarea's proportion of State demand is projected to rise only slightly from the ten percent it accounted for in 1970. Hog water use is expected to fall from 16 million gallons in 1980 to 12 million gallons in 2020. The effect of the reduction in water use by these two kinds of live- stock is counterbalanced, by the end of the target period, by an increase in the water demand of milk cows. Although Subarea 5 has historically accounted for less than 0.4 percent of state milk pro- duction, its small share is rising. Since, in addition, milk demand is projected to increase at the state level,the number of milk cows is expected to double during the target period (to slightly more than two thousand cows and their backup). Their estimated water demand rises from 9 million gallons in 1980 (12 percent of the Subarea total) to 20 million gallons by the end of the target period (25 per- cent). c. Virginia. Because of a changing mix of livestock water demands in the Virginia portion of the study area, the estimated aggregate fluctuates. From 1.44 billion gallons in 1980, it drops to 1.37 billion gallons in 2000, but it rises again to 1.43 billion gallons in the year 2020. In contrast to both the Delaware and Maryland portions of the study area, the major'livestock users of water in Virginia are cattle and calves, They are expected to consume 55.9 million gallons in 1980, a total which rises to 66.2 million gallons in 2020 -- or 56 percent and 66 percent of the State livestock total, respectively, in ea-Ch of those years. Since the share of the Virginia total accounted for by the study area is expected to drop slightly from the 13 percent regis- tered in 1970, this increase in water use is largely attributed to the sharp increase projected for Virginia beef production in the target period. State beef and veal production is projected to rise from 535 million pounds in 1980 to 931 million pounds by the end of the target period. The second major users of water in the Virginia Study Area are hogs and pigs. Over half of Virginia's production is concentrated in the study area portion of the State, a proportion which is projected to rise slightly to 60 percent by 2020. This is counterbalanced, however, by a projected decline in State production, from 161 million pounds in 1980 to 123 million pounds in 2020. As a result, the estimated water demand of hogs and pigs dips from 297 million gallons in 1980 to 184 million gallons in 2020, a drop from 20 percent to 13 percent of the Virginia Study Area total. Appendix 6 65 Milk cows are the third major users of water among Virginia livestock, accounting for 297 million gallons in 1980 (21 percent of the total), and 183 million gallons in 2020 (13 percent of the total). This decline in water use is principally attributed to a shift in Virginia milk production away from the Chesapeake region. From 13 percent of Virginia State production in 1980, the study area's portion is pro- jected to fall to only 7 percent by 2020. Also expected to exert a significant water demand in Virginia are chickens, with 33 million gallons in 1980 and 40 million gallons in 2020. Slightly over one-fourth of Virginia egg production has been concentrated in the study area, a proportion which is expected to continue into the target period. Thus the increase projected for chicken water use is almost entirely a reflection of the rise pro- jected in Virginia egg production, from 95 million dozen in 1980 to 127 million dozen in 2020. (See Figure 6-11) Figure 6-11. Livestock water demand in Virginia. Projections to 1980, 2000, and 2020. 1,750- 1, 313- other livestock million gallons 'R !A i7i .......... 875 -x, cattle and calves I ...... ......... ..... . . . . .-------- 438-.. hogs and pigs milk cow- hickens 1970 1980 2000 2020 Source: Attachment C, Tables 6-C-5 thru 6-C-11. Appendix 6 66 Subarea 1. In this subarea, as well, a changing mix of livestock is projected, and the water demand aggregated over all livestock uses is expected to fluctuate during the target period. The annual livestock water demand projected for 1980 is 37 million gallons. By 2000 the total falls slightly to 35 million gallons, but by 2020 the projected demand rises to 39 million gallons. The major users of water among livestock in the subarea are expected to be cattle and calves. The OBERS projections show substantial increases in the Virginia demand for beef: from 352 million pounds in 1964 to 535 million pounds in 1980, and 931 million poounds in 2020. Subarea I is expected to account for a roughly constant share of the State total during the target period, and therefore its number of beef cattle are expected to rise accordingly. In 1980 beef cattle are projected to exert 40 per- cent of the Subarea's livestock water demand at 15 million gallons, figures which rise to 59 percent and 23 million gallons by the end of the target period. Production and water use of broilers, on the other hand, is expected to drop during the target period. As the Subarea's share of Virginia demands for broilers is projected to rise only slightly dur- ing the target period, once again the projected change is a reflec- tion of OBERS state-level estimates of broiler demand. OBERS projects Virginia broiler production to drop, during the target period, from the 1964 level of 146 million pounds to only 12 million pounds by the end of the target period. The projected number of broilers in Sub- area 1 thus drops sharply during that period, and their water demand is expected to fall from 8 million gallons in 1980 to only 1 million gallons by 2020. The final significant users of water in Subarea 1 are hogs and pigs. Increases in the Subarea's share roughly cancel projected decreases at the state level, and water use remains fairly constant at 11 million gallons, or thirty percent of the subarea total. Subarea 2. The annual livestock and poultry water demand is expected to decline, in this subarea, from 368 million gallons in 1980 to 295 million gallons in 2000 and 256 million gallons-in 2020. Almost all of this reduction is accounted for by declines in the water use of cattle and calves and milk cows. The large increases in Virginia demand for beef are outweighed, in the subarea, by the distributional effect, as the Subarea's share of the State total is expected to decline from 5.5 percent in 1969 to 4.3 percent by 1980 and 2.1 percent by 2020. The number of cattle and calves is expected to drop, during the target period, from 652000 in 1980 to 55,000 in the year 2020, and projected water use accordingly drops, from 260 million gallons to 227 million gallons. Appendix 6 67 Similarly, a projected decline in the Subarea's share of milk de- mand outweighs the estimated increases in milk demand at the state level. From an 8.5 percent share of milk sales in 1969, Subarea 2 is projected to account for 4.4 percent in 1980 and only 0.9 percent by the end of the target period. Thus the water demands by milk cows are projected to drop sharply, from 99 million gallons in 1980 to only 24 million gallons in 2020. Subarea 3. Livestock and poultry water demands are expected 0 to increase in Subarea 3 from an annual total of 119 million gallons in 1980 to 134 million gallons in 2000 and to 162 million gallons in 2020. The increase is almost entirely due to expected increases in the cattle and calf water demand which, in turn, is primarily a reflec- tion of the State-level increases projected by OBERS. The Sub- area's share of state beef sales is not expected to vary from the 1969 level of 1.5 percent. Due to the state-level increases, the number of cattle and calves is expected to jump from 23,000 in 1980 to 36,000 by 2020. Since water use by beef is high relative to that of other livestock, the water use of this component is expec- ted to rise from 92 million gallons in 1980 to almost 150 million gallons by 2020, or 91 percent of the Subarea total. The pro-jected increase in water use by beef cattle easily overshadows projected declines in water use by milk cows. The Subarea's share of State milk sales is projected to fall from 1.5 percent in 1969 to 1.0 percent in 1980, and to 0.5 percent by 2020, a decline which again outweighs the projected increase in State milk demand. Water demand by milk cows is thus expected to fall in the target period, from 24 million gallons in 1980 to 13 million gallons in 2020. Subarea 4. Livestock water use in Subarea 4 is expected to decline sharply during the target period, from an annual rate of 244 million gallons in 1980 to 185 million gallons in 2000 and 154 million gallons in 2020. Again, major users of water are 'cattle and calves, although their water consumption is expected to drop from 108 million gallons in 1980 to only 24 million gallons by the end of the target period. The major factor behind this projection is the estimated reduction in the Subarea's share of'State beef sales, from 2.5 percent in 1969 to 1.6 percent in 1980 and 0.3 percent in 2020. Thus beef water consumption, projected to represent 44 percent of total Subarea livestock water use in 1980, is expected to drop to only 16 percent of the total by 2020. A rising proportion of livestock water use in the Subarea is Ji@ accounted for by milk cows. The number of milk cows is projected to Appendix 6 68 fall slightly, from 8,000 in 1980 to 7,200 after 2000, and water use, accordingly, is expected to drop only slightly from 74 million gal- lons in 1980 to 71 million gallons in 2020. Neither the Subarea's share (approximately three percent) nor Virginia consumption of' milk is expected to dramatically change during the target period. Finally, hogs and pigs are projected to account for 20 to 33 percent of Subarea livestock demands. Changes in the projected levels of Virginia pork demands, the Subarea's share of those demands, and water use rates tend to cancel each other out, and annual hog water use is expected to remain constant in the target period at approxi- mately 50 million gallons. Subarea 5. The water demanded by livestock in 1980 is projected to remain fairly stable in the target period, declining only slightly from 223 million gallons of annual use in 1980 to 219 million gallons in 2000 and 210 million gallons by the end of the target period in 2020. For each of the major three livestock water consumers in the Subarea, the projected distributional effect roughly balances the projected changes in demand at the State level, and both numbers of animals and their water use show no appreciable change. Approximately 55 percent of the Subarea's livestock water use is accounted for by cattle and calves, in which the Subarea's share of State production is projected to drop from 2.00 percent in 1969 to 1.7S percent in 1980 and to 0.95 percent in 2020. The shift is, however, balanced by projected increases in Virginia demand for beef, and water demand is expected to remain constant at roughly 125 million gallons per year. Almost 30 percent of Subarea 5's livestock water demand is pro- jected for hogs and pigs. Projected declines in Virginia demand for pork are expected to be balanced by the Subarea's share of State sales, which rises from 9 percent in 1969 to an estimated 14 percent in 2020. Hog and pig water consumption is expected to total approximately 60 million gallons throughout the target period. The third major users of water among the Subarea's livestock are milk cows, where a slightly falling share of milk production (from 1.8 percent in 1969) is expected to balance projected increases in Virginia milk demand. The estimated milk cow demand for water declines slightly from 33 million gallons in 1980 to 26 million gallons in 2020. Subarea 6. York County is expected to have the lowest livestock water use of any of the subareas., although such water demands are expected to increase sharply during the target period. Appendix 6 69 Total annual livestock water demands are projected to be 30 million gallons in 1980, a figure which jumps to 42 million gallons by 2000 and 58 million gallons by 2020. Over half the livestock demand for water in Subarea 6 is exerted by milk cows. The share of Virginia milk production accounted for by the Subarea is expected to rise from 0.5 percent in 1969 to 1.2 percent by the end of the target period, and this increase is matched by state-level expansion in demands for milk. The number of milk cows and their backup is thus projected to rise from 2,000 in 1980 to over 3,300 by 2020. Projected water use rises accordingly, from 19 million gallons in 1980 to 33 million gallons in 2020. Most of the remaining livestock water use is accounted for by cattle and calves. Although the Subarea's small share of the State total is expected to increase only slightly during the target period, massive projected increases in the demand for beef at the state level would lead to a large jump in both beef cattle numbers and their water use. Water consumption by cattle and calves is expected to rise from 9 million gallons in 1980 to 22 million gallons by the end of the target period. Subarea 7. Livestock water use is expected to be low in this subarea as well. From only 92 million gallons of annual use in 1980, the total dips to 79 million gallons in 2000 and 72 million gallons in 2020. The major livestock water demand in the Subarea, representing 40 percent of the total, is exerted by cattle and calves. The number of animals is expected to dip slightly, during the target period, from 8,900 in 1980 to 7,000 in 2020. This is primarily a reflection of a sharp decline in the Subarea's share of Virginia beef produc- tion, which is projected to fall from 0.49 percent in 1980 down to 0.22 percent in 2020, and counterbalance the increase in the estimated demand for beef at the state level. Cattle and calf water consump- tion is expected to decline from 3S million gallons in 1980 to 28 million gallons in 2020. The principal decline in water use, however, is projected for milk cows. Although state-level demand for milk is expected to rise dur- ing the target period, the increase in demand for milk is far out- weighed by the declining share of sales projected for the Subarea. From 1.9 percent of State sales in 1969, the portion of State milk demand supplied by Subarea 7 is projected to drop to 1.0 percent in 1980, to 0.5 percent in 2000 and, 0.2 percent by 2020. The estimated water demand of milk cows falls from 22 million gallons in 1980, approximately 24 percent of the Subarea livestock total, to 6 million gallons in 2020, or 8 percent of the Subarea total. Appendix 6 70 Thus in the projections of water use by cattle and calves and milk cows, the historically declining Subarea share of State production has been the major factor. In the latter case, the decline is so severe that the Subarea's milk production is expected to be almost entirely distributed to-other areas within the State. Hogs and pigs are the other major users of water among livestock, and their water use is projected to remain roughly constant at an annual rate of 30 million gallons. The declining production of pork projected at the State level is balanced by an expected increase in the Subarea's share of State production. Subarea 8. The already substantial livestock water use in this subarea is expected to increase sharply during the study period. Three hundred twenty-five million gallons of annual live- stock water use are expected by 1980; this figure is projected to increase to 381 million gallons by 2000 and to 479 million gallons by the end of the target period. Most of the gain reflects an expected increase in the water use of cattle and calves. OBERS projects almost a threefold rise in the State demand for beef between 1964 and 2020. At the same time, Subarea 8 is expected to account for an ever-increasing share of the State total: the 1969 share of 2.2 percent with respect to State beef sales is projected to rise to 2.7 percent by 1980 and 3.5 per- cent by the end of the target period. As a result of these changes the water demands of beef are expected to rise from 160 million gallons in 1980 to 351 million gallons, or almost three-quarters of the total livestock demand in 2020. Another major.water demand in the Subarea is.that of hogs and pigs. In the past the Subarea's share of State production has remained roughly constant at one-fifth, and this situation is expected to continue into the target period. The slight decline projected in the water use of hogs, from 126 million gallons in 1980 to 97 million gallons in 2020, is almost entirely a reflection of the projected pork production at the state level. The volume of water expected to be consumed by cattle and hogs somewhat overshadows the demands of milk cows. Though milk cows have the highest water consumption rates of any of the types of livestock considered, only a small portion (less than one percent) of State demand for milk is expected to be supplied by Subarea 8 during most of the target period. A declining Subarea share of State milk pro- duction accounts for the projected fall in water demand by milk cows, from 26 million gallons in 1980 to 11 million gallons in 2020. Appendix 6 71 IRRIGATION WATER DEMAND ASSUMPTIONS AND METHODOLOGY Water demands for irrigation were estimated with reference to crop demand, yield, and total crop acreage. To begin, crop production in each subarea was projected by a shares analysis, to take into account both distributional shifts among the subareas and the projected changes in state-level demands for each crop. Yields were then projected. It was assumed,, as in the OBERS projec- tions, that the rapid rate of increase in agricultural research and development since the second World War would continue, but at a slower rate, during the period 1970 - 2020. Although more extensive use of fertilizers and pesticides, and improved crop varieties and management practices are expected in the target period, investment in agricultural research and development may be dampened. In addition, a lag is expected in the implementation of new technologies.. Both of these factors would tend to diminish the rate of yield growth. Historical yields were found to vary consistently and significantly: for each crop there appeared differences not only between the Chesapeake Bay Study Area and the rest of the States involved (a discrepancy which was especially large for Virginia), but among the subareas themselves. In the most obvious example, yields of subareas in the Delmarva Peninsula differed for almost all crops from the yields for the Western Shore subareas. It was therefore decided to individually estimate target date yields by crop, for each subarea. Yields were projected by the function employed in the projection of subarea production shares, with a slight alteration to allow them to vary with time more than the subarea shares of state production were allowed to. (18) It was possible to estimate acreage for each crop from the estimates of future crop production and expected yield (production per acre). Irrigation water demand was then projected for each crop and subarea as a function of crop acreage. From past trends and knowledge of present irrigation usage, individuals in each subarea estimated the proportion of subarea acreage to be irrigated in the target period. These proportions were applied to the estimates of total crop acreage to obtain total irrigated acreage. The net irrigation water requirement in acre-feet per year for the estimated irrigated acreage of each crop was projected by the Soil Conservation Service Computer Center which, using a computer Appendix 6 72 program in its library, followed the procedure outlined in SCS Technical Release Number 21. Data considered were subarea averages of latitude, temperature, and rainfall; and crop transpiration curves for water use during the growing season., Of major importance in the calculation was potential evapotranspira- tion (PE), or the amount of water which would be lost to the atmos- phere through transpiration from a green crop and evaporation from the soil surface. For each subarea, potential evapotranspiration was calculated using a modified Blancy-Criddle formula, as a function of daylength (itself a function of latitude), temperature, and the trans- piration rates of the crops under study at different stages of their growth. The net irrigation requirement was then calculated as the difference between PE and effective rainfall plus carry-over soil moisture. Factors entering into the calculation of effective rainfall were percolation and runoff losses, assuming storms of average intensity and duration, and the chance of precipitation occurrence. For small vegetables and other specialty crops (19), effective rainfall during the growing season in each subarea was determined assuming a 90 per- cent chance of occurrence, or assuming the rainfall which is expected to be equalled or exceeded nine years out of ten. For field crops and orchards, effective rainfall was determined assuming an 80 per- cent chance of occurrence. Irrigation water demand is therefore expected to be less than or equal to the estimated amount in nine years out of ten for field crops and orchards. This demand is indicative of water use during years which are drier than the average because critical water needs were judged most important. Irrigation demand in normal precipitation years is discussed in the Sensitivity section below. In the calculation of carry-over soil moisture, the soil water hold- ing capacity was assumed to be uniformly that of a loam soil (medium capacity). The amount of water available to a crop under study varied, however, with its rooting depth, with relatively more water available to deeper rooted crops. Once the net irrigation requirement was determined, gross demands were estimated under the assumption of a 65 percent rate of irriga- tion efficiency. Only 65 percent of the total water application is assumed to be available for crop use, with the remainder lost through evaporation or conveyance.(20) The divergence between the historical records of irrigation water use and the projected demandis partly due to the method of projecting demand as a function of the crops' net water requirement. Since this is an ideal amount, it may be in excess of the applications currently recorded, which are often determined by each farmer on the basis of experience. The divergence is further compounded by bias in the Census determinations of irrigation water usage. A comparison of data obtained from irrigation water suppliers with that obtained Appendix 6 73 from farmers suggests that 1) farmers underestimate the amount of water used for irrigation 2) the suppliers overestimate, or 3) both conditions are true. As stated in the 1969 Census of Agriculture It was evident, in reviewing the records received from farms in some parts of the country, that some irrigators had no basis for estimating water use in terms of gallons, acre-feet, or depth of application. ( 21) Finally, since it has been found relatively easy to correct for errors in responses which overestimate irrigation water by com- paring farmers' reports with acceptable maximum application rates, a greater number of underestimation errors in the Census data go undetected than overestimation errors. The combined effect of ideal.demand projections and underestima- tion bias in historical data - plus the fact that projected demands were given for extremely dry years - leads to larger projected increases in irrigation water demands than for any of the other water uses. PROJECTED DEMANDS a. Delaware. This state is expected to exert one of the largest irrigation water demands of any of the subareas. Total irrigated acreage is expected to increase from 20,000 acres in 1970 to 67,000 in 1980 and 91,000 in 2020. Water demands for irrigation are expected to reach over 16 billion gallons in 1980, 19 billion gallons in the year 2000, and over 22 billion gallons in 2020. Approximately 40 percent of the estimated Delaware irrigation water demand is accounted for by vegetables. State production is expected so to increase that., even with improved yields, total acreage will rise from,39,000 acres in 1970 to 49,000 acres in 1980, and 55,000 acres in 2020. By 1980, three-quarters of all acreage in vegetables is expected to be irrigated, and the proportion is expected to increase until virtually all vegetable acreage is irrigated by the end of the target period. The projected demand of vegetable crops rises from 6.1 billion gallons in 1980 to 9.0 billion gallons in 2020. Most of the remaining water demand by irrigation is accounted for by soybeans, nursery crops, and Irish potatoes, with each representing a fifth of the Delaware total irrigation water demand. Although soybean production is projected to increase in Delaware, these gai ns are expected to be balanced by increases in yield, so that by the end of the target period total acreage will remain about the same as current levels, at 144,000 acres. It is estimated that only slight increases in the proportion of these acres are to Appendix 6 74 be irrigated, with that proportion hovering around ten percent. Ir- rigated soybean acreage in Delaware, then, is projected to remain roughly constant in the target period, at 15,000 acres, with a water demand of approximately 4.0 billion gallons annually. The two other crops which are expected to exert significant water demands are nursery crops and Irish potatoes. The number of irTiga- ted acres in nursery crops is expected to jump from 7,500 in 1980 to 10,000 acres by 2020, and their projected water demand rises from an annual rate of 3.2 billion gallons to 4.3 billion gallons in the same period. The estimated water demand for Irish potato irrigation is expected to rise from 3.4 billion gallons on 6,200 acres in 1980 to 4.0 billion gallons on 7,400 acres in 2020. (see Figure 6-12). Figure 6-12. Irrigation water demand in Delaware. Projections to 1980, 2000, and 2020. 25- 18.8. .4 other crops billion gallons it vegetab. les 12.5- -Ott. ursery . . . . . . . . . . ............ fa . . . . . . . . . . . . so Irish potatoes 19 0 IAO 2dOO 20 0 Source: Attachment C, Table 6-C-12. b. Maryland. A tenfold increase in total irrigated acreage in the Maryland portion of the study area is expected in the target period, from 19,800 acres in 1970 to 217,800 acres in 2020. The estimated irrigation water demand dwarfs other agricultural water demands, as it rises from 3 billion gallons in 1970 to 11 billion gallons in 1980, 31 billion gallons in 2000, and by 2020, 78 billion gallons. Appendix 6 75 Much of this demand is expected to be exerted by corn. Total State production is projected to increase from 37 million bushels in 1970 to 80 million bushels in 2020., almost all of which (93 percent in 2020) is expected to be concentrated in the study area portion of the State. Total acreage in corn is projected to rise from 350,600 in 1970 to 496,800 by 2020. Even more rapid than the total acreage expansion, however, is the increase in irrigated acreage, which is projected to rise from a diminutive 0.5 percent of the total in 1970 to 23 percent in 2020, or from 1.,900 acres to over 112,000 acres. All these trends, but especially the latter, are reflected in the projec- tions of the irrigation water demand of corn, which rises from 2 billion gallons in 1980 to 45 billion gallons in 2000 and 59 billion gallons by the year 2020. The second major users of irrigation water in the Maryland Study Area are nursery crops, due primarily to the high application rates (almost 1.5 feet per acre) characteristic of nursery irrigation. Though only 340 acres were registered as irrigated in 1970, the total is expected to rise to 5.900 acres by 1980 and to 23,000 acres in 2020. Estimated water demands for nursery crops are 2.6 billion gallons in 1980 and 10.4 billion gallons in 2020. The irrigation water demand of soybeans in the Maryland Study Area is also projected to rise sharply during the target period, from 0.8 billion gallons in 1980 to 9.7 billion gallons in 2020. Since study area soybean production is projected to diminish slightly in the face of large yield increases, total acres in soybeans is projected to diminish from 161,000 in 1980 to 98,000 by 2020. Counterbalancing this trend, however, is an expected rise in the proportion of acres irrigated, from less than 2 percent is 1980 to 32 percent by the end of the target period,so that from a total of 2,700 in 1980, the esti- mated irrigated acreage in soybeans rises to 32,000 by 2020. A fourth major user of irrigation water in Maryland is tobacco, the demand of which is projected to rise from 0.9 billion gallons in 1980 to roughly 3.8 billion gallons in 2000 and 2020. As with soybeans, the increase is almost entirely due to.an expansion of tobacco irrigation. From 20 percent in 1980, the proportion of tobacco acre- age expected to be irrigated rises to close to 95 percent in 2000 and virtually 100 percent by the end of the target period. The estimated number of tobacco acres under irrigation rises from 4,500 in 1980 to roughly 19,000 after the year 2000. Finally, vegetables are expected to exert a significant and roughly constant demand for irrigation water in the Maryland Study Area, at 2.6 billion gallons annually throughout the target period. In this projection the estimated decrease in Maryland vegetable acreage - from 62,000 in 1970 to 23,000 in 2020 - is again counterbalanced by an increase in the estimated proportion of acres irrigated from 21 percent in 1970 to almost 65 percent in 2020. (See Figure 6-13.) Appendix 6 76 Figure 6-13. Irrigation water demand in Maryland. Projections to 1980, 2000, and 2020. 80- other crops 60- billion gallons 40- 20. .............. vegetables urser -C A >@ soybe ns '< @ e _r Is ...7@:@ tobacco ... . ..... ........... ...... .......... 1@70 196 2000 20@20 Source: Attachment C, Tables 6-C-13 thru 6-C-17. Subarea 1. In this Subarea, located to the north and west of the Chesapeake Bay, both the number of irrigated acres. and the water demands for irrigation are expected to show dramatic increases during the target period. Land in irrigation is expected to increase from MOO acres in 1980 to 10,800 acres in 2020, and water demands will jump from 2.9 billion gallons to 3.8 billion gallons annually. Over 75 percent of these water demands is expected to be generated by nursery crops. The number of acres in irrigation is projected to increase from 5,000 acres in 1980 to 7,000 acres in 2020. Since these increases are expected to be coupled with relatively high appli- cation rates of close to sixteen inches per acre per year, the irrigation water demand is projected to total from 2 to 3 billion gallons annually. Appendix 6 77 One-quarter of all Maryland vegetables are produced in Subarea 1. Although higher yields and a decrease in total acreage in vegetables are projected, the proportion of irrigated acres in vegetable produc- tion is expected to rise from 20 to 40 percent during the target period. Thus, a constant 3,000 acres of vegetables are expected to be irrigated, generating annual water demands of 500 million gallons, roughly fifteen percent of the Subarea irrigation total. The remaining ten percent of the expected irrigation water demand in the Subarea is accounted for by corn, silage, and fruits and nuts. Subarea 2. Irrigated acreage in this subarea on the Delmarva Peninsula is projected to soar in the target period. From slightly less than 10,000 acres in 1970, the projected irrigated acreage rises to over 15,000 in 1980, to almost 47,000 in 2000, and by 2020 to over 150,000 acres of irrigated crops. In line with the projected acreage, the water demands for irrigation in Subarea 2 are enormous. The Subarea is expected to use 4.3 billion gallons for irrigation in 1980; 16 billion*gallons in 2000; and over 55 billion gallons annually by the year 2020. It is the largest single water use in the target period, and accounts for much of the sharp increase projected for the total irrigation water demand of the Chesapeake Bay Study Area. Most of this projected water demand is accounted for by corn, a crop in which all indicators seem to point to irrigation increases. First, total State production of corn is expected to increase from 37 million bushels in 1970 to 53 million and 65 million in the years 1980 and 2000, respectively. By 2020, State production will have doubled, to close to 80 million bushels. Second, this Subarea, with 40 percent of State production in 1970, is expected to increase its share still further to over 50 percent by the end of the target period. Thus, even though yields are increasing - a factor which would tend to decrease acreage - the net effect is that acreage in corn is expected to jump from 180,000 in 1970 to almost 300,000 by 2020. Finally, the proportion of acres which are irrigated is expected to rise. From a minute 0.75 percent in 1970, the proportion of acres to be irrigated is expected to rise to 1.50 percent by 1980 and to 10.00 percent by the year 2000. By 2020, fully one-third, or 33 percent of the 300,000 acres in corn are projected to be irrigated. Its water demand is expected to rise from 1.6 billion gallons in 1980 to 10.3 billion gallons and 41.2 billion gallons in 2000 and 2020., respectively. The latter figure represents 75 percent of the irrigation water demand of Subarea 2 at that date. 4 Another substantial irrigation water demand in this Subarea is that projected for soybean production. Subarea 2 produces almost half the State's soybeans at the present time,.a figure which is expected to increase slightly during the target period. Although the increase in the Subarea's share of State soybean production is offset by Appendix 6 78 declining total State production and yield increases, which lead to a decrease in the number of acres in soybeans in Subarea 2, the pro- portion of acres to be irrigated is expected to rise sharply from 1.4 percent in 1980 to 12.0 percent in 2000 and 45.0 percent in 2020. The number of irrigated acres in soybeans is projected to rise accordingly, from 1,000 acres in 1980 to 25 '000 acres in the year 2020, in which period the projected annual water demand increases from 0.3 billion gallons to 7.7 billion gallons. Silage represents the third major demand for irrigation water in Maryland Subarea 2. Total State production is expected to double, and, as the Subarea's share is expected to rise from 17 percent in 1970 to roughly 20 percent in the target period, silage production in this Subarea is expected to more than double. Though slight yield gains will tend to moderate the effect of production increases in determining Subarea acreage in silage, the proportion of silage acres in irrigation is projected to jump from a fraction of one percent (0.2 percent) in 1970 to 1.5 percent in 1980, 12.0 percent in 2000 and close to 40.0 percent by 2020, at which time 12,000 acres are projected to be irrigated. The rise in acreage under irrigation is the major factor behind the sharp increases in silage demand for irrigation water, from 0.1 billion gallons in 1980 to 3.7 billion gal- lons in 2020. As the water demand of these three crops increases, those of vegetables and nursery crops are expected to diminish in relative importance in Subarea 2. Although the estimated gross annual water requirement for these two crops increases from 2.3 billion gallons in 1980 to 3.1 bil- lion gallons in 2020, its share of the Subarea total falls from 67 percent to 9 percent during the target period. Subarea 3. This Subarea, located in the middle section of the Delmarva Peninsula, demonstrates the effects of expected in- creases in water application rates. Total irrigated acreage is expected to decline, in the target period, from 9,200 acres in 1980 to 8,400 in 2020. At the same time, however, the average gross application rate is estimated to jump from 8.2 acre inches per year to 12.7 acre inches. The combined effect is that the projected total water demand increases from 2.1 billion gallons in 1980 to 2.7 billion gallons in 2000 and 2.9 billion gallons in 2020. As in Maryland Subarea 2, a major demand for irrigation water is corn, expected to constitute over 70 percent of the Subarea total by the end of the target period. In 1970, Subarea 3 accounted for 30 percent of State corn production, and the share is expected to increase to 40 percent by the end of the target period. The State total for corn production in Maryland is expected to double by 2020, and thus, despite substantial yield increases, total acreage in corn is projected to rise - from 125,000 acres in 1970 to 160,000 in 1980 and close to 190,000 acres by 2020. Its expected annual water demand jumps from 0.8 billion gallons in 1980 to 2.1 billion gallons in 2020. While Appendix 6 79 such acreage in corn might potentially exert a large demand for irrigation water, however, only a small portion of the Subarea's corn acreage is expected to be irrigated: 1.3 percent in 1980, a pro- portion projected to climb to only 3.0 percent by 2020. Corn acreage under irrigation in the target period is thus not expected to exceed 6,000 acres, and its projected water demand in 2020 does not exceed 2.1 billion gallons. Of lesser importance in the subarea are vegetables-and soybeans. Forty-two hundred acres of vegetables are projected to be irrigated by 1980, a number which drops to 1,200 acres by 2020. Its expected water demand totals 700 million gallons in 1980, or 33 percent of the Subarea irrigation total, and 200 million gallons in 2020, or 7 percent of the total. Irrigated land in soybeans is expected to decline from 1,700 acres in 1980 to 750 acres in 2020, due principally to a diminishing Subarea share of State production. Its irrigation water demand is expected to fall from 500 million gallons in 1980 to 200 million gallons in 2020. Subarea 4. This Subarea is expected to show one of the largest increases in irrigated acreage in the Chesapeake Bay Study Area. The 1970 total of only 900 acres in irrigation is projected to double to over 1,900 acres by 1980, and to jump to over 14,000 acres by the end of the target period. Annual water demands for irrigation, only 0.2 billion gallons in 1970, are expected to rise to 0.6 billion gallons by 1980 and to 6.1 billion gallons by the year 2020. Over half the demand for irrigation water in Subarea 4 is accounted for by nursery crops. While only 200 acres of such crops were irri- gated in 1970, the total is expected to increase to 600 acres in 1980, and to 8,000 acres in 2020. These acreage increases are coupled with the high application rates characteristic of irrigation for this type of crop, to generate water demands which account for 50 to 60 percent of the subarea's total for irrigation water and close to 4 billion gallons in 2020. Large increases are also projected in the water demands for corn irrigation in the Subarea. While an insignificant portion of corn acreage, 0.1 percent, was recorded as irrigated in 1970 - a figure which is expected to change little by 1980 - 25 and 50 percent of all acres in corn are projected to be irrigated, respectively, in 2000 and 2020. Although a falling share of State production mitigates these changes, irrigation water demand for corn is expected to in- crease to 1.1 billion gallons annually by 2020. Other water, demands in the Subarea are those of irrigated tobacco and soybeans. Though for tobacco the proportion of acreage in irrigation is expected to rise from 20 percent in 1980 to 95 per- cent after the year 2000, Subarea production is projected to fall to Appendix 6 80 less than half the 1970 level, and initial increases in water de- mands for tobacco are expected to fall off toward the end of the target period,to 500 million gallons. Soybeans are projected to exert demand for irrigation water not in the immediate future, but only by the year 2000, when 850 acres (25 percent of the soybean total) will be irrigated. The water demand for soybean irrigation at that time is expected to total 300 million gallons. The number of irrigated soybean acres, their proportion of the total, and the soybean water demand are all expected to double between 2000 and 2020. Subarea S. This Maryland Subarea, located west of the Chesa- peake Bay and just north.of the Potomac River, is expected to show the largest proportional increases in irrigated acreage and water demands of the subarea in the Chesapeake Study Area. In 1970, only 1,600 acres in the Subarea were irrigated, a use of approximately 0.2 billion gallons. By 1980 over 4,000 acres are projected to be irrigated; by 2000 the figure jumps to 24,000, and it rises over 33,000 acres by the year 2020. Annual water demands are projected to jump to 0.8 billion gallons in 1980, to 5.7 billion gallons in 2000, and to 9.5 billion gallons in 2020. An increasing proportion of demands for irrigated water in the Sub- area stems from nursery crops. The number of irrigated acres in this category is expected to rise from an insignificant quantity in 1970 to 300 acres in 1980, 1,500 acres in 2000, and 8,000 acres in the year 2020. With the high application rates characteristic of nursery irrigation, nursery crop water demands are expected to rise from 12 percent of the Subarea's total in 1980 to nearly 40 percent of the total in 2020, accounting for 0.1 billion gallons at the former date and 3.5 billion gallons at the latter. A.s irrigated nursery crops in the Subarea increase in relative importance, tobacco is expected to decline: from seven-eighths of the Subarea irrigation water demands in 1980 to only one-third in 2020. Since tobacco demands substantially less water per acre than nursery crops (0.5 as opposed to 1.5 feet per acre), it is projected to use less irrigation water -- 3.1 billion gallons in 2020 -- than the smaller quantities of irrigated acreage in nursery crops. Corn and soybean irrigation water demands, though insignificant in T-he beginning of the target period, are expected to be increasingly important in Subarea 5, and account for one-third of the total irrigation water demand in the Subarea after 2000. By 2000, 25 per- cent, and by 2020, 50 percent of the Subarea's corn acreage is pro- jected to be irrigated, and- to exert a demand, respectively, of 1.2 billion gallons and 1.5 billion gallons. Three-quarters of the soybean acreage in 2000 and virtually all of that acreage in 2020 is projected to be irrigated, exerting a demand of 1.2 billion gallons and 1.5 billion gallons, respectively, in those target years. Appendix 6 81 c. Virginia. Irrigated acreage in the Virginia portion of the study area, while not expanding at the Maryland rate, is projected to rise sharply from'the 18,100 recorded in 1970 to 68,300 in 2020. Annual water use, 2.9 billion gallons in 1970, is expected to total 14.6 billion gallons in 1980 and 24.0 billion gallons in the years 2000 and 2020. Among the major users of irrigation water in the Virginia Study Area are nursery crops. Irrigated acreage in nursery crops is expected to rise from the total of 2,800 in 1970 to 7,500 in 1980, 16,000 in the year 2000, and 20,500 in 2020. Their estimated annual demand for irrigation water rises proportionately, from 2.8 billion in 1980, to 7.9 billion gallons in the year 2020. The latter figure represents close to one third of the Virginia Study Area total for all crops. Of similar significance is the water demand expected to be exerted by corn. From a total of 1.1 billion gallons in 1980, its estimated demand rises sharply to 8.0 billion gallons in the year 2000 before dropping once again in 2020 to 6.3 billion gallons. In 1970, only I percent of all acreage in corn was recorded as irrigated, a pro- portion which, however, is expected to rise to 2 percent in 1980, 28 percent in 2000, and 37 percent in 2020. At the same time, total corn acreage in the Virginia Study Area is expected to diminish from 178,600 in 1970 to only 45,000 in 2020, a reflection of a similar decline at the state level. It is the interaction of these two trends which leads to the fluctuating levels of water demand expected of Virginia corn, the estimated increase in the proportion of irrigated acres first outweighing the decrease in total corn acres, then the reverse. A third major user of irrigation water in the Virginia Study Area is Irish potatoes, accounting for an estimated 5.4 billion gallons in 1980, 4.3 billion gallons in 2000, and 3.4 billion gallons in 2020. This decline is principally a reflection of the drop in potato pro- duction projected at the state level, from the 1970 total of 6.2 million bushels to 3.3 million bushels by 2020. It is tempered some- what by the projected concentration, by 2020, of virtually all of Maryland production in the study area portion of the State. Vegetables are expected to exert the last major demand for irrigation water in the Virginia Study Area, at 3.0 billion gallons in 1980 and 1.3 billion gallons in 2020. The decline once again reflects a projected drop in state-level production, from 36,500 acres in 1970 to only 13,400 acres by 2020. The estimated share of State production accounted for by the study area rises only slightly, from the 64 per- cent recorded in 1970 to 72 percent at the end of the target period (see Figure 6-14). Appendix 6 82 Figure 6-14. Irrigation water demand in Virginia. Projections to 1980, 2000, and 2020. 25 - other crops ............. . ........ . e billion ..... nurs ry gallons 12.5 corn. I A r r 7 I V v r I ish potatoes . . . . . . . . . . ty vegetab es 1@70 1980 2000 20120 Source: Attachment C, Tables 6-C-18 thru 6-C-25. Subarea 1. In contrast to each of the Maryland subareas and Delaware, this group of counties - located at the tip of the Delmarva Peninsula - is expected to show a decline in irrigated acreage and water demands. From 22,000 acres in 1980, cropland with irrigation is projected to drop to 16,000 acres in 2000 and 12,000 acres in 2020. Its water demand of 8.4 billion gallons in 1980, the largest of any subarea but Delaware, is expected to fall to 6.3 billion gallons in 2000 and 4.7 billion gallons in the year 2020. The largest demand for irrigation water in this subarea is that of Irish potatoes, constituting over two-thirds of the total. In 1970, -90 percent of all potatoes produced in Virginia were raised in Sub- area 1; the proportion is expected to rise to 95 percent by 1980 and to 98 percent by the end of the target period. This increase is off- set, however, by diminishing State production of potatoes, a decrease of 20 percent by 1980 and close to 50 percent by the end of the tar- get period. Thus, total acreage in potatoes in this subarea is ex- pected to fall from 11,000 in 1980 to 6,800 in 2020, and irrigated acreage, consistently half the total, is projected to fall accordingly. The estimated water demand for potato irrigation drops from S .4 billion gallons in 1980 to 3.4 billion gallons in 2020. Appendix 6 83 A second major demand for irrigation water in this subarea is that of vegetables. As in the case of potatoes, Virginia state production is expected to diminish during the target period, total acres in vegetables falling from 21,000 in 1980 to 14,000 in 2000 and 9,600 in 2020 - close to a 60 percent decline from the 23,000 acres in vegetable production in 1970. Again, as a constant half of the total acreage in vegetables is projected to be irrigated, irrigated acreage in vegetables is expected to show a sharp drop, and the irrigation water demand for vegetables is estimated to fall from 3.0 billion gallons in 1980 to 1.3 billion gallons in 2020. Subarea 2. In this subarea, irrigated acreage is expected to jump from less than 1,000 acres in 1970 to 3,000 acres in 1980, 7,100 acres in the year 2000, and 8,100 acres in 2020. Water use is expected t'o increase from 0.1 billion gallons in 1970 to 1.1 billion in 1980, 2.7 billion in 2000, and 3.1 billion gallons in 2020. Over half of the increase in water demands is accounted for by nursery crops. From a negligible number in 1970, irrigated acreage of these crops is expected to rise to 1,500 acres in 1980, 3,400 acres in 2000 and 4,000 acres in 2020. In addition, nursery crops are pro- jected to require high application rates, 15 inches per acre per year. Their projected water use therefore rises from 0.6 billion gallons in 1980 to 1.7 billion gallons in 2020. Other crops which are expected to exert significant water demands in this subarea are corn, hay, and silage. Although corn production for the state of Virginia is expected to fall to one-third the current amount in the target period, and the share of state production accounted for by Subarea 2 is projected to fall (from 4 percent to just under 3 percent), the proportion of acres in corn to be irrigated is expected to rise from a negligible amount to over 40 percent. The net effect is an increase in irrigated acres in corn from a negligible amount in 1970, to 240 in 1980, and 1,000 in the years 2000 and 2020. The projected irrigated water demands in the latter years, at 400 million gallons, represent roughly 10 percent of the Subarea total. Of similar magnitude are the water demands of hay and silage. The state-level increases in Ya production are expected to be counter- balanced in the target period both by the Subarea's declining,share of that production and by increased yields. The initial increases estimated for hay acreage in the target period are thus not expected to be sustained through the end of the target period. Irrigated acreage is projected to remain a small proportion of the total (only three percent by the end of the target period), and water demands from-this source are not expected to exceed 420 million gallons annually. The rise in State production of silage is expected to be counterbalanced by a falling Subarea share and increased yields to Appendix 6 84 produce a drop in total acreage in silage. This drop is counter- balanced, however, by a rapid increase in the proportion of total acres to be irrigated - from less than 1 percent in 1970 to 3 per- cent in 1980, to 27 percent in 2000 and to almost 60 percent by the year 2020. The number of irrigated acres is therefore expected to level off at approximately 1,100 acres, with an annual water demand of approximately 350 million gallons. Subarea 3. The irrigation water demands exerted by this subarea on the western edge of the study area are the lowest of any except York County. From a negligible amount of irrigated acreage in 1970, the total is not expected to rise above 600 acres at any time in the target period. There are expected to be only 230 irriga- ted acres in 1980, exerting a demand of 84 million gallons; 430 acres in the year 2000, with demands of 164 million gallons; and S60 acres in 2020, exerting demands of only 217 million gallons annually. Roughly two-thirds of the total acreage and water demands are pro- jected to go to nursery crops. Other demands in the Subarea include those exerted by corn and vegetables. Subarea 4. In this subarea, located also on the western edge of the study area but farther south than Subarea 3, irrigated acreage is expected to increase rapidly. From 1,300 acres and a de- mand of 0.2 billion gallons in 1970, the number of irrigated acres is expected to increase to-6,000 in 1980; 17,000 in 2000 and close to 20,000 in 2020. Water demands are expected to amount to 2.0 billion gallons in 1980, 5.8 billion in 2000, and 6.7 billion gallons in 2020. Over half the projected total water demand is accounted for by nursery crops. Although only a negligible amount of irrigation has been em- ployed in this subarea in the past, total irrigated acreage is pro- jected to rise to 2,600 in 1980, 7,800 and then 9,600 in the years 2000 and 2020. Irrigated water demand is projected to rise from 1.0 billion gallons in 1980 to 3.6 billion gallons in the year 2020. A second major demand in this subarea is that exerted by corn. The expected decline in total corn acreage - from 23,500 in 1970 to 18,000 in 1980, 9,500 in 2000, and 5,470 in 2020 - roughly matches the falloff in the projected Virginia total corn production, since the Subarea's falling share of State production, and its expected increase in yield relative to the rest of the State tend to cancel each other out. The proportion of these acres to be irrigated, how- ever, is expected to rise during the target period from 2 percent in 1970 to 3 percent in 1980, and to 47 percent in 2020. The number of irrigated acres is expected to rise from 600 acres in 1980 to 2,600 in the year 2000, where it is expected to level off with an annual water demand of I billion gallons. Appendix 6 85 Silage and hay are expected to each account for 10 percent of the irrigation water demand during the target period. Although the total number of acres in silage is expected to increase only 10 percent from 1970 to 1980, and only 30 percent from 1970 to the end of the target period, the proportion of acres in irrigation is ex- pected to rise from a negligible amount to 6 percent in 1980 and 25 percent in 2000 and 2020. Six hundred acres are expected to be irrigated in 1980, and 3,000 acres in each of the latter years, with water demands jumping from 200 million gallons in 1980 to 800 million gallons after the year 2000. In hay production, the Subarea's share of the Virginia total is expected to decline but slightly from the three percent share recorded in 1970, and the 40 percent increases in State production over 1970 levels are accordingly reflected in Subarea production and acreage. Irrigation demands are kept down, however, by the small proportion of hay expected to be irrigated, a total not exceeding 10 percent even by the end of the target period. Annual water demand is expected not to exceed 800 million gallons during the target period. Subarea S. One of the largest subareas, Subarea 5 is located on the Western shore of the Chesapeake Bay and encompasses ten counties. Despite its size, however, the irrigation demands of this subarea are relatively moderate. By 1980, only 4,100 acres are expected to be irrigated, a figure which increases to roughly 10,000 acres in the latter part of the target period. Total water demands are expected to increase from 1.2 billion gallons in 1980 to 3.3 billion gallons by the year 2000 and 3.6 billion gallons by 2020. The largest component of the projected irrigation water demand is the demand of corn, a crop whose share of total Subarea water demands is expected to rise from 33 percent in 1980 to over 50 percent after 2000. As in some of the other subareas, the major factor in the in- crease is expected to be a sharp rise in the proportion of corn acre- age which will be irrigated. In 1970, only 0.1 percent of all corn acreage was reported to be irrigated - by 1980, the proportion is expected to increase to 1.9 percent, by 2000, 14.4 percent, and by the end of the target period in 2020, 24.6 percent. Thus, despite falling State totals and Subarea production of corn, irrigated acreage is expected to rise to 1,100 acres in 1980, and to 5,000 acres after the year 2000. Its estimated water demand jumps from 0.4 billion gallons in 1980 to 1.9 billion gallons in the latter part of the target period. Other irrigation water demands in Subarea 5 are those of nursery crops and silage. Irrigated acr 'eage in nursery crops is expected to increase from 200 acres in 1970 to 670 acres in 1980, 1,SOO acres in the year 2000 and 2,000 acres in 2020. With relatively high appli- cation rates of fourteen inches per acre per year, nursery crops are Appendix 6 86 projected to account for roughly 25 percent of the irrigation water demand in the Subarea, at 300 million gallons in 1980 and 800 million gallons in 2020. The large increase in silage production estimated for the State of Virginia (a doubling of production by 2020) is moderated by a pro- jected increase in yield. Total Subarea acres in silage production, then, are expected to increase from S,700 in 1970 to only 5,800 by 1980, and 6,800 by the year 2020. Since the proportion of silage acres in irrigation, however, is projected to increase (from 1 percent in 1970 to 18 percent in 1980, and 30 percent after 2000), silage is expected to exert a significant demand for irrigation water in Subarea 5: 300 million gallons in 1980, and 600 million gallons after the year 2000. 4 Subarea 6. Consisting of only one county, York, this sub- area is expected to exert the weakest demand for irrigation water of all the subareas: from 16 million gallons in 1970, the total jumps to 25 million gallons in 1980, 42 million in 2000 and only 83 million gallons in 2020. The only significant use of irrigation water in Subarea 6 in 1970 occurred in the production of nursery crops, a fact which is not ex- pected to change in the target period. In 1970, 33 acres of nursery crops were irrigated. The total is projected to rise to 60 acres by 1980, and to 200 acres by the year 2020. Application rates though, are expected to decrease from 17.8 inches per acre recorded in 1970 to 15.4 inches per acre per year. Thus, the increase expected in the irrigation water demand in Subarea 6 - from 25 million gallons in 1980 to 83 million gallons in 2020 - is attributable to increased acreage in irrigated nursery crops. Subarea 7. In this subarea, consisting of Virginia Beach and Chesapeake City, water demands for irrigation are also expected to be relatively slight. Total irrigated acreage is projected to decline slightly from an estimated 3,100 acres in 1980 (the 1970 total) to 2,950 acres in 2000 and 2,8SO acres at the end of the target period. An increase in application rates, however, is expected to offset the decline, and, from 670 million gallons in 1970, projected irrigation water use jumps to 970 million gallons in 1980, 920 million gallons in 2000 and 930 million gallons in 2020. Nursery crops are expected to account for over 80 percent of all irrigation water demands in the Subarea. The irrigated acreage in nursery crops is projected to decline from the 1970 level of 2,,400 acres to 2,260 acres in 1980 and 2,100 acres in 2000. The slight increase to 2,300 acres in 2020 still leaves the irrigated acres pro- jected for nursery crops below the 1970 level. Annual irrigation water demand in the target period is expected to fluctuate in the range from 730 to 790 million gallons. Appendix 6 87 The remaining irrigation water demands in Subarea 7 are expected to be exerted by corn (approximately 100 million gallons annually) and vegetables (70 million gallons in 1980 and 2000, to drop to half that amount in 2020. Subarea 8. Irrigated acreage in this subarea is expected to jump sharply in the target period from current levels. In 1970, only 1,000 acres of cropland were irrigated; by 1980, this total is projected to reach 2,700 acres, and by 2000, the total is expected to 4. be 18,500 acres. In the latter part of the target period, however, a reduction in the level of crop production in the Subarea is expected to lead to a reduction in irrigated acreage, and the total will fall to 14,900 acres. Paralleling the trend in acreage irrigated is the demand for irriga- tion water. In 1970, 0.3 billion gallons of water were the recorded demand in the Subarea. Demand is expected to -rise to 0.8 billion gallons in 1980 and to 6.3 billion gallons in 2000; but by 2020, the total is projected to fall off to 5.0 billion gallons. The most significant crop use of water in the Subarea is that of corn. The Subarea share of Virginia corn production during the target period is expected to remain at roughly 20 percent (up slightly from 16 percent in 1970). Although, following State reductions, sub- area production of corn is expected to fall, the proportion of acres in irrigation in the Subarea is expected to rise from 0.3 percent re- corded in 1970 to 1.9 percent in 1980, and to close to 50.0 percent after the year 2000. It is largely due to this increase in the pro- duction of corn acreage irrigated that estimated annual corn water demand rises from 0.4 billion gallons to 4.7 billion gallons between 1980 and 2000. In the latter part of the target period, however, projected declines in State corn demand lead to an estimated falloff in that demand to 2.9 billion gallons in the year 2020. A second major user of water in the Subarea is expected to be peanuts. By 1980, Virginia state production is projected to increase by 66 percent, and as the Subarea share is expected to diminish only slightly, Subarea production and acreage are both expected to increase dramatically (a 56 percent increase in production, and 41 percent increase in acreage). One percent of all acreage in peanuts, or 500 acres is expected to be irrigated, exerting an annual demand of 200 million gallons. In the latter part of the target period a declining Subarea share of State production (from 34 percent in 1980 to 12 per- cent in 2020) is more than offset by increases in irrigation and in production at the state level. Two thousand acres are expected to be irrigated in 2000,.and 2,500 acres by 2020, and water demand is projected to jump to 600 million gallons and 800 million gall-ons respectively in each of those years. Appendix 6 88 Other major users of irrigation water in the Subarea are expected to be nursery crops and hay. The total number of irrigated acres in nursery crops is expected to increase from 200 in 1980 to 2,000 in 2020, exerting an annual water demand which rises from 100 million to 700 million gallons in the same period. Projected increases in the proportion -of hay to be irrigated, from I percent in 1980 to roughly 6 percent after 2000, are expected to account for most of the increase in the annual water demand of hay irrigation - from 100 million gallons to 400 million gallons. TOTAL AGRICULTURAL WATER DEMAND In 1980 the agricultural water demand in the Chesapeake Bay Study Area is projected to total 76 billion gallons. 42 billion gallons, or 55 percent of the total is accounted for by irrigation; 30 billion gallons (39 percent) is accounted for by domestic water use, and 4 billion gallons (6 percent) is accounted for by livestock. In the year 2000, the agricultural water demand in the study area is projected to total 114 billion gallons. Seventy-six billion gallons, 67 percent of the total, is attributed to irrigation; 33 billion gall'ons, or 29 percent of the total is attributed to domestic water consumption and 4 billion gallons, 4 percent of the total, is attributed to livestock. In the year 2020, agricultural water demand in the study area is pro- jected at 165 billion gallons. Irrigation water demand is projected to account for 76 percent of the total, at 125 billion gallons. Dom- estic water demand is estimated at 36 billion gallons, or 22 percent of the total, and the water demand exerted by livestock is projected to total 4 billion gallons, or 3 percent of the total. The enormous rise in irrigation water use is due principally to a large increase in the proportion of crop acreage which is expected to be irrigated. See Table 6-19, Figure 6-15, and Attachment C for tabular and graphical representation of these demands. Attachment C contains a detailed breakdown of water demands,by subarea. Appendix 6 89 (D :J CL H. X ON Table 6- 1-9 Annual agricultural ater use by subarea, projections to 1980, 2000 and 2020, Chesapeake Bay Study State and 1980 2000 2020 subarea Uropsl/: Livestock Domestic Cro2slj: Livestock : Domestlc2@ Total Crops_11: Livestock DomestQ1 Total Million gallons CHESAPEAKE BAY 42,238.3 4,276.3 29,928.3 76,442-9 75,937-9 4,177.7 33,439.8 113,55S.4 1-24,881.7 4,318.0 35,488.6 164,687.3 DELAWARE 16,903.1 526.7 2,182.9 19,612.7 19,217.2 478.8 2,833.3 22,529.3 22,390.5 459.S 3,188-9 26,038.9 MARYLAND Study area 10,674.4 2,312.9 12,862.0 25,849.3 31,182.9 2,328.7 13,599.7 47,111.3 78,018.2 2,429.3 15,843.3 96 290 8 1------------ 2,938.2 1,069.8 6,274.1 10,282.1 3,381.3 1,177.2 5,755.9 10,314.4 3,837.5 1,381.9 6,701-1 11:870@5 2------------ 4,251.1 596.9 2,410.8 7,258.8 16,104.1 S44.1 2,748.6 19,396.8 55,671.4 S12.7 2 984.5 59,lS8.6 3------------ 2,050.9 389.8 1,933.7 4,374.4 2,654.9 410.5 3,029.1 6,094.5 2,894.1 422.1 4:483.1 7,799.3 4---------- - 588.5 179.6 128.0 896.1 3,338.7 119.9 194.2 3,6S2.8 6,105.9 82.6 244.9 6,433.4 5------ 845.7 76.8 2,115.4 3,037.9 5,703.9 77.0 1,871.9 7,6S2.8 9,509.3 80.0 1,429.7 11,019.0 VIRGINIA Study area 14,660.8 1,436.7 14,883.4 30,980.9 25,537.8 1,370.2 17,006.8 3,914.8 24,472.0 1,429.2 16,456.4 42,357.6 1------------ 8,408.5 36.7 1,116.6 9,S61.8 6,260.3 3S.3 1,329.0 7,624.6 4,737.4 38.6 1 497.0 6,273.0 1,106.9 367.6 3,561.0 5,035.S 2,701.1 294.6 4,359.4 7,35S.1 3,118.6 255.6 4:813.9 81188.1 84.2 119.2 1,228.9 1,432.3 164.9 133.8 1,440.9 1,739.6 217.1 162.0 860.5 1,239.6 4-------- - -- 2,032.3 244.0 2,875.4 5,151.7 5,M.2 185.4 3,305.0 9,303.6 6,706.0 IS4.1 3 613.6 10 473.7 5- ---------- 1,218.2 222.5 1,697.4 3$138.1 31317.2 219.1 2,094.6 5,630.9 3,581.4 210.3 2:350.9 6:142.6 6------------ 25.1 30.3 406.6 462.0 21.1 42.0 198.5 261.6 83.2 S7.7 228.4 369.3 7------------ 972.5 9115 1,192.7 2,256.7 919.4 79.2 1,068.6 2,067.2 933.9 71.7 919.9 1 925 9 8------------ 813.1 324.9 2,804.8 3,942.8 6,340.6 380.8 3,210.8 9,932.2 5,094.3 479.2 3,172.2 8:745'7 Irrigation demands are for "dry" years. See irrigation "Methodology and Assumptions" for projection methods and "Sensitivity Analysis" for "normal" year irrigation demand. Residual population, independently served. 1950 1960 1970 1980 2000 2020 ANNUAL WATER 'USE? 150,000- A V MILLION GA=NS .7 ,< <7 < ,V 'J Ir -7 c J A r L, 4 4 VA @,J < r 4 1009000. > A r> > > r v&V>'J < r V L. V ,V > V < > A I>A> > '. %' 4 A A L. 'r > , 4 -1 L r r 'J i > ', r it' 6 T r 1,1' .4 V V > > a , .1 ,,,4rA < V IRRIGATION , & A L. r qr > < V6 A I. k ' AA % A 4. A V"A Ar. .1A A A < > V < < "Ir .A I r A > Ir 1:4 v r > 50,000- 7 > A ,V V 7 > r V < r A .7 > < T A < ......... .*0M V r .. .. ..... .... ....... ... ... 211@ K_ --Q _Y D 0 M E S T I C Figure 6-15 Total Agricultural Water Demands, Chesapeake Bay Study Area l/ Irrigation demands are for "dry" years. See irrigation "Methodology and Assumptions" for projection methods and "Sensitivity Analysis" for'hormal" year irrigation demand. FUTURE SUPPLY The agricultural activity projected for the study area is decentral- ized and in most cases dependent upon ground water for its source of supply. It is fortunate, then, that the Chesapeake Bay is located in one of the most water-rich areas in the United States, the Atlantic Coastal region. The water resources of the Chesapeake have the potential to meet all the demands imposed by agriculture in the foreseeable future. In this Appendix the agricultural water demands are projected with reference to farming activity in the target years, and especially to factors such as population and food requirements. The factors which influence water supply, however, are somewhat less affected by man's activity. Some of the factors - including climate and the geological underpinnings of a region - will change little if at all during the period under study. ASSUMPTIONS Meteorological conditions are assumed to remain constant, essentially unaltered by nature or manmade forces during the period under study. Rainfall is assumed to continue in the area at its present rate, as will temperature, wind, and other factors which affect the rate of evapotranspiration. Soil conditions, which affect the rate of seepage, are also assumed to remain constant. No net withdrawals or additions to the ground water reservoir are assumed in the long run. This Appendix represents an analysis of supplies and demand of water within the agricultural sector alone. As in all partial analyses, the interrelations with other demand sectors is kept to a minimum, and it is assumed that these competing demands do not severely deplete the ground water reservoir in agricultural areas. Appendix 5 includes additional information on the availability of water supply. Appendix 6 4 92 SOURCES OF SUPPLY Water to fill the agricultural water demand in the study area is supplied by streams or other surface water., wells tapping the ground water reservoir, and by farm ponds of the impoundment and excavation types. SURFACE WATER a. Streams. Flowing streams are depended upon by.farmers with access to them. Only a small portion of study area water demands are met by streams, though, because of lack of access, variable quality, and poor dependability of flow, especially during periods of drought when spot demands are high. Streamflow is heavily dependent upon precipitation, and where the latter is erratic, supply becomes irregular. (See Chapter IV,"Future Needs and Problem Areas") b. Impoundment Farm Ponds. One solution to the problem of erratic rainfall has been the "impoundment" type farm pond. Designed to capture surface flow and store it for times of shortages, such ponds are, in effect, earth filled dams protected with spillways and vegetation. They vary in size from small livestock watering ponds to sizeable ponds over forty acres in surface area,which have the capacity to store over two hundred acre-feet of water. The impoundment farm pond has been especially-important as a supply source in the Piedmont, where ground water is not as available as it is in the Coastal Plain and the water table is not so easily tapped. Such ponds have been the chief source of water for irrigation and for livestock in the historical period from 1949 to 1969, and they are expected to continue as such into the future. (22) With an abundance of impoundment sites of all sizes, the Piedmont is especially fortunate in its large and well distributed impound- ment sites (in excess of 640 acres), which have the potential, if developed, to meet rural nonfarm and even industrial needs well into the future. It is anticipated that in areas where farm pond sites and streams are scarce there will be an increasing need for ponds'of this type to meet farm and nonfarm demand on a community basis. GROUND WATER The aquifers in the Coastal Plain, wherein most of the study area lies, furnish far greater quantities of fresh water than the streams Appendix 6 93 and rivers. Because its unconsolidated sediments contain an abund- ance of water bearing sands and gravels, the Coastal Plain's ground water from the aquifers is its most widely used source of water. The sediments of the Atlantic Coastal Plain consist of layers of sand, shelly sands, and gravels separated by clays, each part of a complex system rich in water bearing potential. Much of the Atlantic Coastal Plain, including most of the Delmarva Peninsula, is blanketed by the Quaternary group, a group of geologically recent sediments up to 220 feet in thickness. Characterized by a scarcity of interstitial clay and silt, they possess extremely high water transmissivity. The Quarternary sediments are the most productive water bearing unit in the study area. The other physiographic province in the study area is the Piedmont, a relatively narrow, moderate relief plateau between the Coastal Plain and the mountains. It is composed of crystalline rock of the igneous and metamorphic classes, rock which to the east forms the basement complex beneath Coastal Plain sediments. Although it is characterized by a wide variety of water yielding properties, the rock of the Piedmont is not generally considered to be good water bearing material. Ground water may contain unacceptably high concentrations of minerals, depending upon the type of rock from which it was obtained. a. Wells. Springs and wells are an important source of supply for domestic use throughout the study area, for both the farm and the nonfarm residual populations.. In the Coastal Plain the majority of wells are dug or shallow bored. The quality of the water is excellent, and because of the . high%trans- missivity of the aquifers, yields generally run from 300 to 1000 gallons per minute (gpm), with up to 4000 gpm in portions of the study area where the Quaternary aquifer is especially thick. There are several layers of aquifers in the Coastal Plain available to be tapped by wells on the surface. Over most of the Delmarva Peninsula, for example, there are more than five alternative sources of fresh ground water (containing less than 1000 mg/liter dissolved solids). The choice of aquifers is based upon desired water temperature, quality and quantities of the water desired, and the cost of well construction. Despite its drawbacks., the Piedmont's supply of ground water is available almost everywhere from springs and wells of all depths. The influence of topography is frequently more important to the yield of wells in this region than the composition of the underlying rock: yields of wells in valleys are often significantly greater than the yields of wells located on hillsides. In general, however, Piedmont yields are substantially lower than those of the Coastal Plain, running from five to fifty gallons per minute. Though Appendix 6 94, sufficient to meet domestic needs.wells may not meet irrigation and crop requirements. b. Dug Farm Ponds. "Dug" or "excavated" ponds are large, shallow pits usually ten to fifteen feet in depth which tap the ground water reservoir. In the Coastal Plain, the ready accessibility of ground water makes V- the dug pond the most common source of supply. The high recharge rate of ponds of this type outweighs their generally limited storage capacity to make them a good source of water for irrigation and live- stock. Jb AVAILABLE WATER SUPPLY Water for the purposes of irrigation, livestock and the rural domestic population is derived from wells, farm ponds and, to the lesser extent, surface flowing streams as discussed in the previous section. The amount of fresh water that will ultimately be available to meet future demand was estimated under the assumption that the ground water reservoir is under equilibrium; that is, in the long term, ground water discharge from an area is equal to the recharge from precipita- tion and other sources. In the hydrologic cycle, the first demand for precipitation is the replenishment of soil moisture which is depleted by evaporation and transpiration (evapo-transpiration). After this demand is met, water percolates downward through the soil to the water table, or ground water reservoir. Once in the reservoir, most of this water moves downgradient and discharges into streams, the Bay, or the ocean, though a small amount is transmitted to the deeper artesian aquifers to replenish water withdrawn from artesian sources. The base flow of streams is that part of total stream flow which is discharged from underlying aquifers; it is therefore a measure of the perennial ground water yield of the study area. This base- flow has been estimated as high as 26 percent of the 44-inch aver- age annual precipitation, and as low as 15 percent. Weighting its measurements by drainage area upstream, the U.S. Geological Survey in the Existing Conditions Report (Appendix B) estimates the stream baseflow to be 20 to 25 percent of the mean annual precipitation, or an annual flow of about 10 inches. These ten inches represent an annual yield of approximately 275,000 gallons per acre, or 3,521,300 million gallons for the Chesapeake Study Area as a whole (9647.3 mgd). The yield of ground water for farmland, similarly calculated, is presented in Table 6-21. Appendix 6 95 Table 6-20 Farm acreage and available ground water: Chesapeake Bay Study Area 1980 2000 2020 Acreage 4,686,000 4,128,800 3,601,150 Million gallons 1,272,500 1,121,200 977,900 "Go annually Million gallons 3,486.2 3,071.7 [email protected] daily It should be noted in the interpretation of Table 6-20 that the estimation of agricultural water supply for the study area is heavily weighted toward supplies within the Coastal Plain phys- iographic province, which are more dependent than Piedmont supplies upon ground water. Due to the relative impermeability of the under- lying basement rock in the Piedmont, its water supply is of necessity oriented toward surface water supplies in the form of streams and, primarily, the impoundment type farm pond. It is difficult to estimate the proportion of precipitation which is gathered in impound- ments. A complete inventory of the available water supply from all sources which is available for all uses, is given in Appendix 5 of the Future Conditions Report, "Industrial and Municipal Water Supply." FUTURE NEEDS AND PROBLEMS Since in any subarea agricultural demands will be competing with municipal and industrial demands for the available water supply, it is necessary to compare demands of each of these uses with the fresh water supply. Only by such a comparison can the various demands' overall impact on available resources be determined. That analysis is discussed in Appendix S of the Chesapeake Bay Futur-e- Conditions Report. Appendix 6 96 Among the problems discussed in this Appendix are agriculture- related problems of erratic supply, salinity, environmental pol- lutants, and sedimentation. ERRATIC SUPPLY PROBLEM Although the water supply in the Chesapeake Bay Study Area is more than sufficient to meet projected demands when both are con- sidered in aggregate, the analysis would not be complete unless the erratic natures of agricultural demands and of the supply necessary to meet them were considered. On the demand side, it is important in the efficient production of crops for the soil in which they are raised to have adequate soil moisture in the rooting zone at all times. If the soil moisture in the root zone of a crop is insufficient to ensure its development at the normal rate, its yield is reduced and the crop suffers "moisture stress", a condition of drought. The quantity of water needed varies not only by crop and by rooting depth, but also by stage of crop growth, by soil type and by temperature and humidity. From Table 6-21 it can be seen that shallow rooted plants are not as drought resistant as those with deeper rooting systems. Virginia data show that shallow rooted plants such as vegetables can be expected to experience 58 days of water shortage 5 out of every 10 years. Another variable is the stage of a crop's growth. Yields can be drastically reduced by water shortages at crucial times. It is generally most important for a crop to receive adequate moisture late in the growing season. Figure 6-16 shows that soybean yield reductions are much greater if moisture stress is experienced in later stages of growth. When soil moisture available to corn during tasselling or pollination is reduced to the wilting level, yields are reduced by as much as 50 percent. If wheat is exposed to moisture stress late in the season, yield is sharply reduced through the shriveling of grain. Appendix 6 97 Table 6-21 Drought Frequency 1 Average number days when @oil moisture Is Inadequate for optimum crop yields-April to September: Number of days with 0 look of water In: If plant roots ex(end to a depth that the sail In One Two Three Five Its toot zone year years years years will hold; In Ion In Ion In ton In ton I Inch of water 120 97 63 68 2 Inches of water 95 70 51 23 3 inches of water 78 49 29 5 4 Inches of water 58 32 13 0 5 Inches of water 43 19 1 0 It Informational source, V.P.I. Technical Bulletin 128, April 1967. "Agricultural Drought in Virginia.'* FIGuRE 6-1,6 Change in soybean yields 3.0 - - 8 due to moisture stress 2.5 - - 7 applied at selected per- Z - 6 iods of growth 2.0 - - 5 AY Source: Technical Bulle- E 1.5 - - 4 3: tin, No. 1431. USDA, 0 %J (D - 3 ERS. 1974 >_ 1.0 - 2 0.5 - &Y=Y C_Y I 0 1 1 P 0 1 2 3 4 5 6 7 8 Stage of growth at which stress occurs Appendix 6 98 The agricultural water supply can be equally erratic. Although an enormous quantity of ground water is stored in the sediment beneath the study area, only a small portion is recoverable by wells. Further, under the conditions of water table equilibrium assumed in the supply analysis, heavy withdrawals of ground water in one location will both draw down the water table and curtail the base flow of local streams unless sufficient recharge enters the system to cover its losses. The variability which most affects agricultural activity, however, is that associated with precipitation. Annual precipitation in the Chesapeake region averages 40 to 45 inches, of which 8 to 10 inches is runoff. This supply is more 4. than adequate to meet the total agricultural demands of the study area listed in Table 6-19. (see page 90) The aggregate supply of water available for agriculture, though - and especially to crops - is highly variable, and this variability is the key to many of the problems of agricultural water supply. Precipitation in the study area varies from one month to the next, (as seen in the monthly precipitation averages given in Figure 6-17), and in summer months it is often in the form of high intensity thundershowers of brief duration. 5 in.- 4 in.- mean mean 3 in.- 80% % % 2 in.- -90% 2 .90% 1 in.- % April May June July Aug. Sept. Figure 6-17. Rainfall by month: mean, and 80 percent chance of occurrence, and 90 percent chance of occurrence. Chesapeake Bay Study Area. Source: Monthy Precipitation Probabilities by Climactic Divisions: 23 Eastern Study. Miscellaneous Publication No. 1160. Economic Research Service and Environmental Source Services Administrations. 1969. Appendix 6 99 Precipitation is also highly variable from one year to the next (see Figure 6-17), and the rain expected to be exceeded eight or nine years in ten is reduced in some parts of the study area to only 40 and 25 percent, respectively, of its monthly mean. This variability has a particularly adverse effect upon crop produc- tion, for which the main source of supply might be precipitation. It also affects the water supply of excavated farm ponds, as the water table, the surface of such ponds, varies in response to precipitation. Thus in any question of water sufficiency for agricultural demand, it is not yearly aggregates but local supplies and demands which are important. If supply problems do arise, they are likely to be location and time specific. SOLUTIONS The unpredictability of precipitation in the study area and the poor holding capacity of many of its sandy soils (23) have led to a sharp increase in supplemental irrigation in the region, an in- crease reflected in the projected demands for irrigation water. Irrigation is expected to be applied not only to highly valued crops, but with increasing frequency to crops with low per-acre value so that the yield reductions attendant upon moisture stress are avoided. To meet the goal of efficient crop production it is as important in irrigation to achieve the proper distribution of water as it is to achieve the proper volume. It has been*shown, for example, that a total application of 21 inches, infrequently distributed over a season, can result in a 58 percent reduction in potato yield over that obtained using 19 inches frequently and evenly applied. (24) If the water needs of a crop cannot be met through irrigation, the damage to crop yield is permanent, and it cannot be rectified by heavy water applications later in the season. The need for adequate irrigation is particularly important toward the harvest time, for if a crop cannot be brought to maturity because of water shortages, all previous irrigation water will have been wasted. It is thus not only aggregate volume of water, therefore, but a proper distribution of the supply throughout a season which must be ensured if the supply problem is to be met. The monthly distribution of irrigation water requirements is listed in the Sensitivity Analysis below. Measures to meet this need might be the construction of deep wells for irrigation purposes and the development of large storage ponds for community use. The latter measure might be particularly effective in areas where storage sites are limited. During times of extreme dryness, Appendix 6 100 perhaps a necessary measure is the monitoring of ground water withdrawals by other large users of water., such as food processors., located in agricultural areas. Another solution to spot shortages is the use of stream water. The problems in stream water use are more numerous, though, than those of ground water use. Streams are more susceptible to pollution than groundwater, for example, and a major problem in their employment up to the present time has been their lack of accessibility. Further, the base flow of streams can be reduced sharply when the gound water table drops in times of drought. This reduces the water available from streams when it is most needed. Nonetheless, the value of streams as a potential source of water cannot be neglected - particularly in areas with skimpy ground water supplies,and where sediment and pollution problems are minimal. SALINITY PROBLEM If streams are to be considered as potential sources of water, the problem of salt water intrusion must be addressed. Crops, live- stock, and humans all have a limited tolerance for salt consumption. Irrigation and livestock watering practices must each be altered to take into account the presence of even low concentrations of salts in the water supply. When salt concentrations reach a conductance of 8 to 10 millimhos per centimeter (8,000 to 10,000 micromhos), all crops show some yield reduction, and for many the reduction is more than fifty percent. In recognition of this data, and the fact that salt accumulates exponentially with evaporation in the top layers of soil, the Report of the National Technical Advisory Committee to the Secretary of the Interior (1968) recommends the following classification for crop salinity hazard: 6V Appendix 6 101 TDS ma/l CC mmhos/ca Water for which no detri- mental effects will usually be noticcA ................. 0.75 Water wbich can have det- riment.1 effects on sensi- Table 6-22-CrOP .tive crops ................. 500-1.000 0.75-1.50 Water that may have ad- Salinity Hazard verse effects on many and Total Dis- crops and requiring care- ful management practices... 1.000-2,000 [email protected] solved Solids Water that can be used for (TDS) tolerant plants on pCr=S- able soils with careful management practices ........ 2.000-5,000 3.00-7.50 Source: Report ofthe National Technical Advisory Co=nittae to the Secretary of the Interior (1968). Like its demand for fresh water, a crop's tolerance for salt water varies according to its stage of growth. A germinating seedling is most sensitive to salinity, and well established plants tend to be more salt-tolerant than younger plants. Tolerance of salinity also-varies from one crop to the next. As seen in Figures 6-18 through 6-20, vegetables are more sensitive to salinity than field or forage crops. (Also shown in the figures is the non- linear crop response to increases in salinity. For many crops, once the threshold concentration is reached in which yields are re- duced, additional concentrations tend to further reduce yield rapidly). Tolerance of salinity varies for each type of consumer. Adult sheep have the highest tolerance, as they can safely consume water containing 12,900 part per million (ppm) dissolved solids. (See Figure 6-21). Pigs and poultry, respectively, can tolerate 4,290 ppm and 2,860 ppm dissolved solids. Most stringent are the standards in water for human consumption. Water containing less than 500 ppm dissolved solids can be safely consumed without awareness of salinity, Ground water in the study area is generally of good quality, containing less than 250 mg/l dissolved solids. Where it is available, it is generally suitable for all agricultural and domestic uses, except for iron and acidity problems in some locations. Appendix 6 102 Figure 6-_11 8 -0 Salt tolerance of vegetabis crops" EC, IN MiLLMW@(@S 0 7 4 6 a to 12 14 16 PER (V AT 15 C Beet s Spinach 7.,n.10 I Broccoli Potato Corm syooetpolato 'The md"Ild "it tOleld"COS OPPIV to the period of rapid plant growth and Lettuce vall.,ation. from the late seedling stage rd. Crops in each Category ale Bell pepper . r nked in order of decreasing UK lot onmon trance. Width of tile bar riermt to each L IM3011111111111111 crop. indicates the Ififed of increasing Carrot salinity on yield. Crowilimas are placed at 10. 25, and 50-parcent yi@Hd mduc Beans Wns 25% 10% 50% YIELD REDUCTION Figure 6- 19 -S31t tolerance of field crops* EC, IN MiLLIMMIS PER CM. AT 25 C 0 2 6 8 10 1 14 36 Zo 2 Safi,, -,bean Stsbarpa VJ @Ttftv indicated sell tolerAMOS Apply to the period of tepid plant growth am] R,ce ir-dav) I I', biiturAiian. from the We %4*01ne. stage ofmard. Crops in each are C., n rarAed in onder of decreasing San lot. 8'exibea. erance. Width ut the tim MKI to each crop indicates the effect of Increasing fie. salinity an yield. Crosslines we placed at 10, 25. and 50-porcent VWW ro. Beans duct-ond. 25% 10% 50@1,. YIELD REDUCTION Yield Reduction: 0 Figure 6-2Q- so taiiers"fit Of forap cropse EC. IN MiLLI&INGS PER CM At 25 C 0--- 4 6 a 10 12 14 i cr/. St-rmuda grass .1'eingrass Z? ClIsted healgraiis I V 25% Battey may L 5 10*10 Perqnn:jI rye Ma,a.nFXraSs ri siirdsfoot trefoil L *The intimated sisilt tolerances; apply m Beardless ddrya the partial of empal plaint grovift and maturathork himin the late sawdewig "4" ommowd, Cv%m iR oath talmillp ranked in oidw of decriparaing lot. sz Iwo wrAmo. Width of the bar next to each cmis indicalles the Rec of mucresslag Miadow to.t if sm-dy on YWM. Cirosallimas we placed I cloversij A#sl: is rod at 10. 25. and 110jimmoso yield re. ductions. 25% 10% 50% YIELD REDUCTION Source: Report of the National Technical Advisory Comittee to the Secretary of the Interior (1968). Appendix 6 103 Figure 6-21 - Tolerance to Salinity: Human, Crop, Livestock. -SHEEP Adapted from Extent of Brackish PIGS Water in the Tidal Rivers ;--POULTRY of Maryland, Maryland 2000 Geological Survey, 1970 CROPS Soo -HUMAN Soo CONSUMPTION 200 sor too 1044 10,000 124,040 SPECIFIC CONDUCTANCE, IN MIC10111#10S AT 25% Streams in the study area, as well, are low in dissolved solids, and are suitable for most agricultural uses, except in the down- stream reaches of streams which are subject to tidal intrusions of saline water. Figure 6-22 documents the extent of salt water in Maryland and Delaware.. While data on the extent of salinity in Virginia is not available, salt water may be expected to in- trude to Fredericksburg along the Rappahannock River, to West Point on the York River, and to Hopewell along the James River. (2s) The actual extent of salinity in stream water depends in part upon quantity of fresh water stream flow, which, in turn is affected by precipitation, overland flow, and base flow water. In a dry year, the fresh water flow can be expected to be considerably reduced, and brackish water may intrude further upstream than it would if more precipitation fell on the region. Base flow can also be reduced by the use of ground water resources to a degree wheTe the water table is drawn down. This practice tends to reduce stream flow at surrounding locations, leading to more intrusion of saline water than would be the case without such withdrawals. To the extent the withdrawals reverse the normal gradient of ground water, saline water might also intrude into ground water supplies. Although the rate of intrusion into ground water aquifers is minute compared to the surface water rate, (26) the effects can be much more damaging since wells may be unusable for years. Appendix 6 104 P f N III S Y@L V A NI A 1 c I' S Z- A S eN + Aft -4- J@Li, q + + so -41 10V 7.1 -A- 4 Z,, EXPLANATION + Legal boundary between tidal and nonlidal water "%. Maximum observed silent of brackish wooer so Predicted maximum extent of wooer having a 0 specific conductance of 1000 micromhas Predicted minimum extent of water having a specific conductance of $000 micromhos 110 0 IF 20 30MILES Figure 6-22. Extent of brackish water in Maryland. Source: Extent of Brackish Water in the Tidal Rivers of Maryland, Maryland Geological Survey, 1970. + A Appendix 105 Another problem is posed by evaporation. While the above-listed crop salinity tolerances are rough limits within which, under experimental conditions, yields are not affected, in actual prac- tice a considerable part of the gross amount of water applied to crops can be expected to evaporate. Salt concentrations in the soil thus tend to be greater than in application water, and a sur- plus of water over plant needs must be used to flush them from the soil. In this fashion the use of brackish water entails greater applications of irrigation water than would otherwise be necessary, and it creates a danger of salt contamination in ground water supplies. Evaporation factors must be especially taken into account in times of drought, when salt concentrations of even mildly saline water are much increased after application. SOLUTION it is largely a management problem to ensure that withdrawals of water fall within safe consumption limits. Similarly, it is up to the individual manager to safeguard his fields from the effects of concentration buildups due to evaporation. Large withdrawals from the groundwater reservoir, if saline water intrusion is the result, may on the other hand pose a public problem. The effects of such withdrawals should thus be carefully monitored and, where necessary., accompanied with regulation to protect the reservoir from contamination. ENVIRONMENTAL POLLUTANTS As the trend toward larger farms continues, pollutants from agricultural activity can be expected to become a potential source of serious water quality degradation. Large livestock farms require greater quantities of high quality water than the smaller ones, and they accordingly result in larger, more concentrated discharges of pollutants. Livestock wastes are a potential problem since during the target period production is expected to be located more often in large, concentrated feedlots; much of the projected yield increases for crops are predicated upon increased use of chemical fertilizers. As in the case with other agricultural water problems, these wastes are characterized by variability. Unlike municipal sewage systems in which, as one source states, "a liquid waste stream of reasonably predictable composition and quantity Appendix 6 106 arrives continuously through a well-defined outfall line", agricultural wastes are generated in a series of remote functional units, where distance precludes central disposal. (27) The wastes so generated are often discharged only intermittently into the environment - the result, for example, of the flushing action of storm waters, or the periodic exercise of an agricul- tural function such as pumping a manure storage pit or applying pesticides. A_ Agricultural wastes are further characterized as "point" or "non- point" sources according to whether or not the wastes are released in a well-defined flow from a clearly identifiable source. While some agricultural pollutants, such as large feedlots or irrigation wastewaters, fall under the definition of agricultural point sources used by the Environmental Protection Agency (EPX), (28) most are released into the environment in nonpoint, or diffuse, flows which are more difficult to control. The three major types of environmental pollutants discussed in this section are fertilizer, pesticides, and livestock wastes. FERTILIZER a. Problem: In recent years the trend toward more wide- spread use of chemical fertilizer on agricultural land has been largely responsible for their increased productivity. It is an unfortunate side effect of fertilizer use that it may also increase the fertility of'streams where agricultural runoff is received, When such streams feed into ponds, the process of fleutrophication" begins, in which nutrients present in, the water stimulate the growth of aquatic plants. Algae blooms 'Spread across the surface of the water, and taste and odor problems arise; the aging process is quickened, with a bog or swamp the eventual result. Nitrates in the runoff from fertilized agricultural areas can also cause health problems. If such runoff contaminates water for consumption, the presence of nitrate causes methoglobinemia, a disease in which the blood is depri ved of needed oxygen. In livestock the symptoms are watery eyes, a rough hair coat, and loss of appetite resulting in weight losses or diminished pro- ductivity. The United States Public Health Service defines the standard of nitrate nitrogen consumption at a maximum of 10 parts per million (ppm), an amount considered safe for infant feeding. Alga,blooms are generated, however, when the nitrate concentra- tion of pond water reaches only 0.30 ppm and phophorous concen- tration only 0.01 ppm. The environmental impact of fertilization Appendix 6 107 must be considered, then, even where small amounts are involved. Where large amounts of fertilizer are used, as in the high yield production levelsprojected in the target period, impacts may be even more significant. The use of fertilizer in the Chesapeake Bay Study Area is estimated for recommendations for fertilizer applications presented in Attachment Djable 6-D-1. These rates are not expected to change by 1980, but by the latter part of the target period they may repre- sent application rates which are somewhat lower than the appropriate amounts. Even where yield increases are attributed to improve crop varieties, fertilizer application rates would tend to rise, for it is often the efficient utilization of fertilizer which lies behind the productivity of new varieties. Table 6-D-2 lists the recommended fertilizer applications for the estimated level of production in the study area. An estimated 63,000 tons of nitrogen was used in 1970, a total which is expected to rise to 73,000 tons by 1980, and to 77,000 tons by the year 2020. Estimated phosphorous applications rise from 68,000 tons in 1970 to 78,000 tons by 2020; and potassium applica- tions in the same period are expected to rise from 73,000 tons to 82,000 tons. The small increase in fertilizer use, in the face of a general reduction in crop acreage, points to greater concentration of fertilizer. Given these increased concentrations, the question arises as to the amount of this fertilizer which may be expected to enter the surface and ground waters. Rough estimates of losses range from 0.1 percent to 1 percent of all nutrients applied in a watershed to 6 to 10 percent of nutrients applied on steeply sloping experimental plots. But beyond the simple generalizations that nitrates, the most mobile of nutrients, are likely to enter both gound and surface water, and phosphates are likely to be "fixed" in the soil, little can be said without referring to specific crops, fertilization practices, precipitation, slopes, and soil conditions. Nutrients are commonly lost through leaching, or percolation down through the soil, and through runoff. For leaching to occur, it is generally necessary that large quantities of water in excess of the evapo-transpiration require- ment of crops be present in the soil; otherwise evaporatic- near the surface and capillary action tend to hold nutrients near "-he surface. Leaching losses are thus more likely during the winter and spring than during the crop season. Appendix 6 108 The influence of the field capacity of a soil on leaching is seen in Figure 6-23. Nitrates accumulate near the surface in clays and silts, which are relatively high in their water holding capacities. Conversely, the low capacity sandy soils contain relatively small nitrate accumulations. 000 - N APPLIED ANWALLY Figure 6-2 3. Nitrate-N in the Lbs/A upper 8 feet of 4.soil types 0 after the annual a-pplication 800- 100 of N fertilizer for 7 years =200 222300 to continuous corn in Missouri. 600- Source: G.Smith, 1968. OD I 0 400- 'Cr Z 200- 0 CLAY MN SILT SILT LOAM SAND Large amounts of nitrogen, added to the soil as fertilizer, increase the nitrate available for leaching in some cases, but according to one source, no general statement can be made that this is true on a widespread basis. The effect of excess nitrogen fertilizer on the environment is not fully known: in many cases, the nitrate re- mains within the root zone, and is available for succeeding crops even after irrigation (29), (See Figure 6-24) The issue of nitrate accumulation is further clouded by the import- ance of inherent soil fertility. In one experiment (Stewart, 1970), no nitrate accumulated under levels of fertilization (143 kg/ha) which were the average for the test area. Even under very heavy fertilization, there were no accumulations below 30 feet (Table 6-25). The author concludes that the soil fertility level, and not its source, largely determines whether nitrate accumulates. Appendix 6 109 Figure 6-24-Nitrate-nitrogen found I in Sharpsburg silty clay loam profiles after corn harvest, as affected by irrigation and amounts of applied nitrogen. Source: Herron, et al., 1968. 0.3 0.9 1.5 M E a so MO M N applied anzamlly for 5 years. kg/ha Depth 0 143 357 992 meters (feet) N03-N. kg Aa 0-0.3 (0-1) 0.5 1.2 1.8 202 Table 6-23-Nitrate accu- 0.3-0.6 (1-2) 0.0 0.8 6.8 164 0 6-0,9 (2-3) 0.2 0.8 3.9 is mulations under irri- . 0.7 3.1 13 0.9-1.8 (3-6) 0.1 1.8-2.8 (6-9) 0.2 0.5 6.5 33 gated grain sorghum 2: 8-3 7 (9-12) 0.6 0.7 7.8 14 .74:6 02-15) 0. 5 0.2 5.8 14 fields on a slowly per- 4.6-5.5 (15-18) 2.0 - - 20 meable soil fertilized 5.5-6.4 (18-21) 3.4 - - 15 6 - - 10 with varying rates of 7:,-,:, (21-224) 1.4 - 3 4-8 3 (24- 7) 1.0 - 8.3-9.2 (27-30) 0.3 - - 2 ammonium sulfate. 9 2-10.2 (30-33) 1.3 - - 1.4 2.2 10.2-11.1 f33 -36) 1.7 - 11.1-12.0 (36-39) 1.2 - 1.4 12.0-12.9 (39-42) 1.3 - 1.2 Source: B.H. Stewart, 2.9-13.8 (42-45) 1.4 - 9 0:' 0 1970. 13.8-14.8 (45-48) 1.0 - The other type of nutrient loss occurs through runoff. Such losses vary by crop, runoff volume, nutrient application level and season. Figure 6-25 graphically depicts the relation between runoff and nutrients, the impact of increased fertilization on nitrate concen- trations and seasonal variations in runoff and nutrient loss. Nitrate losses were substantially higher in the highly fertilized Watershed 2 than in Watershed 1, and in the winter months than in the summer and fall. The effect of the presence of crops in the summer and their absence in winter is seen in both runoff and nitrate concentration patterns. Despite the facts that summer is the season with most precipitation in the watersheds studied and that snowmelt is not an important factor, runoff is highest in the early spring, and it is reduced in summer months when crops are present. Nitrate concentrations, as well, are sharply reduced during the summer months. Appendix 6 110 N03 N LOST IN RUNOFF 4 4 3 3 W.& 2 2 0 elm a- 0 NOs- 4 CONCENTRATION IN RUNOFF 12 10 6- 4 2 0 a RUNOFF 4 4 2 0 .. . . . . . . . . . . . 0 01 A J@A' 0 O-r-t-r-,-%' A 0 1) F A 0 oij F A" J 3 N 1i M M J S " 1.0 M NJ J A3 N 1964 1909 19?0 1971 1972 MONTH AND YEAM Figure 6-25 - Monthly losses of NO -N as related to runoff amounts, NO 3-@ concentration in runoff, and fertilization. a = surface application of 112 kg N/ha; b = surface application of 56 kg N/ha. Source: V. J. Kilmer, et. al. Table 6-24 shows nutrient loss data pertaining to various crops. The concentration of nutrients in runoff is greatest for fallow fields, followed by continuously planted corn and corn, oats, and hay in rotation. In 1967,'the concentration of total nitrogen in runoff ranged from a high of 85.71 ppm in a fallow field to a low of 0.39 ppm in a hay field in rota- tion. Runoff rates clearly vary between crops. Appendix 6 Table 6-24-Annual soil and nutrient losses, by crop Average ,Crop and year Soil annual Total N MR 4 -N No3 _M P K loss runoff : Wee inches lb/ac ppmY Wee ppm-LI lb/ac pi;;V_ lb/ac pp7j17 lb/-a. p F.1-7 Fallow 7,600 3.80 25.96 30.16 .29 .34 .80 .93 .04 .04 1.78 2.07 Corn-continuous 720 .91 4.00 19.39 .10 .48 .10 .48 .10 .48 .50 2.42 Cora-rotation 380 2.05 2.00 4.31 '.10 .21 .29 .63 .10 .21 .60 1.29 *Owts-rotatLon 20 .20 .10 2.16 0.0 0.0 .10 2.16 0.0 0.0 JO 2.16 0 3.41 .30 .39 0.0 0.0 .10 .13 .10 .13 .80 1.04 4 1967 Tallow 20,560 4.63 N .93 85.71 .20 .19 .48 2.59 2.47 4.55 4.34 Corn-continuous 6,280 2.98 19.18 2B." .30 .45 .80 1.19 .04 .05 1.16 1.72 Corn-rotation 1,239 2.35 6.69 12.58 .10 .18 .07 .13 .10 .18 .60 1.12 -Osts-rotation 2,040 2.09 9.37 19.81 .10 .21 .16 .34 .10 .21 .60 1.26 @Hay-rotatioa 0 3.83 3.71 6.58 0.0 0.0 .04 .04 .29 .34 5.17 5.97 l/ Average concentration of nutrients in runoff. Source: Tinums. D. R., Burwell. R. E., and Holt, R. F. 1%8. Loss of crop nutrients through runoff. Minnesota Sci. 24 (4): 1. b. Solutions: It is difficult to state the exact extent of nitrate losses through leaching. Under some conditions nitrates move into groundwater supplies after only one growing season, while under others, it takes ten to fifty years to move through a forty-foot soil profile to enter the groundwater. It is clear however, that chances of leached nitrate entering groundwater are considerably reduced if nutrients are not applied in amounts substantially in excess of crop needs, particularly on sandy soils. Growing cover crops in the off season also reduces leaching losses. Such measures are especially important if the water table is close to the surface, as it is on some parts of the Delmarva Peninsula. Runoff losses of nutrients, while a much greater problem in the study area than leaching losses, can also be controlled through proper applications of fertilizer. If both crop needs and inher- ent soil fertility are taken into account in fertilizer application, excess nitrate available for runoff is sharply reduced. Fertilizers can be applied in solution for efficient crop utilization. This technology is likely to be employed to an increasing extent with the spread of irrigation systems, as it cuts both labor costs for the farmer and production costs for manufacturers. The quantity of nitrate available for runoff 4 is also reduced by slow-release fertilizers, applied only once per season. Appendix 6 112 PESTICIDES a. Problem: The years following World War II marked a new era in the use of pesticides in the United States with the in- troduction of DDT and others in the chlorinated hydrocarbon group. These pesticides were noted for their toxicity and persistence, and soon became the most popular pesticides used. The very properties responsible for their popularity, however, have made pesticides the source of adverse environmental effects such as mortality, loss of production, and changes in estuarine plant life. A concentration of only one part per billion (ppb) DDT has resulted in a twenty percent reduction in oyster growth, and a similar concentration of another chlorinated hydrocarbon, endrin, has caused the death of fish and aquatic life. The greatest pesticide danger stems from sudden discharges into the environment of relatively high concentrations of the toxic material. A heavy flushing rain over agricultural fields can result in the sudden occurrence in a receiving stream of a pesticide concentration which is overwhelmingly toxic to aquatic life. Seepage from the industrial waste lagoons of pesticide producers, pesticide formulatDrs, and pesticide users has polluted ground and surface waters and rendered them unfit for agricul- tural use. More common than a single large discharge is the steady almost continuous discharge from agricultural land of pesticides in small concentrations. Many pesticides, though insoluble, are tightly held by soil particles, and when soil is washed away by agricultural runoff, the pesticide is carried with it in minute quantities. Such losses rarely account for concentrations of more than one part per billion in receiving streams, though up to five percent of all pesticides applied may be lost with sediment. Table 6-25 is noteworthy, not just for the minute levels of pesticides which are found in the major rivers of the United States, but for the widespread nature of the rivers' contamina tion. Though the levels of pesticides present amount to only fractions of one part per billion, they are generally found in well over 70 percent of the rivers and lakes surveyed, and some, such as DDT and DDE, are found in 95 percent of the sampled waters. The danger to the environment of such small, persistent con- centrations is considerably.greater than their size would seem to indicate. Many pesticides, with DDT a prominent example, leave water preferentially for soil and sediment. Thus, in waters containing only 0.1 ppb of the substance, bottom Appendix 6 113 Sampling Stations Geographic Distribution Positive (No. States with Positive Positive and Or pteSUMptiVely Positive No. Rivers and Quantified Range Compound samples) Lakes Positive No. ppW - Table 6-25-Chlorinated dieldrin 36 39 56 0.002-0.118 endrin 28 23 30 0.003-0.094 hydrocarbon insecti- DDT 28 22 23 0.007-0.087 DDE 28 17 18 0.002-0.018 cides and related tDE I 1 1 0.083 compounds in major aldrin 10 1 1 0.085 heptachlor 16 0 0 - rivers ?@ the United heptachlor epoxide 0 0 0 - States.- BHC 2 0 0 trace *Xcept Alaska and Hawaii. Adapted from data in "Chlorinated Hydrocabon Pesticides in Major Source: H.P. Nicholson U.S. River Bosins" by Weaver, Gunnerson, Breidenbach, & 1.4chtenborl. Public Health Rpla. 491-493. 1965. 1 and D.W. Hill, 1970. .4nimurn detectable concentrations of dieldrin. andrin. DDT, DM aldrin slid beptachlor ranged from 0.002 to 0.010 ppb. Comparable values for TDE. haplachlor apoxide and BHC were 0.075, 0.075, and 0.025 ppb, respectively. sediments have been found to contain from 20 to 500 ppb. Exchange of materials in aquatic life is rapid, and DDT can be found shortly after it appears in the bottom sediments in aquatic plant life. Shortly after it appears in plants it is found in fish. At each step in the food chain, the toxic substance becomes increasingly concentrated, until, by the third or fourth level, the substance reaches a concentration which can cause considerable harm. It is for this reason the minute concentrations of persistent, toxic pesticides are hazardous. b. Solutions: Since most pesticides from agricultural use enter streams through runoff and soil erosion, the problem of pesticide runoff and hazard can be ameliorated with many of the methods used to control soil erosion. One method, for example, has been to create buffer strips of filiage along the banks of streams to prevent pesticides and herbicides from entering them. In some controlled experiments, concentrations in the receiving stream have been considerably reduced using this method. Another solution has been the sharp regulation of industrial wastes in which pesticides have been present. In contrast to pesticide concentrations in agricultural runoff, concentrations in indus- trial wastes have generally been of lethal levels. The problem of small and widespread pesticide concentrations will not be solved until the very persistent pesticides are no longer used. As in the case of fertilizer, an environmental constraint must be added to the optimization procedure, so that a balance is achieved between effectiveness and cleanliness. Recent technological advances in pesticides appear to be making this possible. Appendix 6 4- 114 LIVESTOCK WASTE a. Problem: A major factor in the modern production of live- stock has been the concentration of facilities. Broilers are now grown and processed in large enclosures; the production of hogs in- creasingly takes place in confinement operations; and beef feedlot operations are increasingly concentrated. Enormous quantities of wastes are generated by such operations: � cattle feedlot with 10,000 head has the same sewage output as � city of 160,000 people. Operations of over one thousand live- stock units (30) have been designated point sources of effluent by the Environmental Protection Agency. Although it represents a considerable reduction from current levels, some 18 to 20 million tons of livestock raw waste can be expected to be generated annually in the Chesapeake Bay Study Area during most of the target period (see Attachment D, Tables 6-D-3 and 6-D-4 ). The dangers of runoff from feedlots are well recognized, and it may be expected that during the target period, the combination of environmental controls on small livestock operations and existing controls on increasingly widespread. large operations will solve much of the problem. Even if runoff is eliminated, however, two major problems in livestock operations will remain: the seepage of pollutants from livestock wastes into ground water, and the ultimate disposal of such wastes. Although the soil beneath feedlot operations-tends to be com- pacted and its permeability reduced, enormous concentrations of nitrates nevertheless accumulate beneath such operations. In the experimental results shown in Figure 6-26 and Table 6-26 , an aver- age of 1,436 pounds of nit-rate per acre were found in the soil cores taken beneath feedlots, in contrast to the 261 pounds per acre taken from dryland farms. In the groundwater beneath feedlots was found up to 38 parts per million (ppm) of ammonium nitrogen, and an average of 13 ppm nitrate nitrogen. The second major problem in livestock production is the ultimate disposal of waste matter. At present, the chief means of disposal of captured runoff and the vast quantities of livestock wastes is land spreading. In one ton of manure, there are roughly 10 pounds of nitrate, 5 pounds of phosphate, and 10 pounds of Appendix 6 115 0. - - - - - - - - - -- 70 t 2. 4 A CORRALS 5 ----IRRIGATED FIELDS ....... CULTIVATED DRYLANO FIEL03 6 0 5 2'0 75 Iro 35 11.4 Figure 6-2.6- Average nitrate-nitrogen distribution with depth of profiles as affected by different land uses in eastern Colorado. Source: B. A. Stewart et al., 1967 -4ro-fi-I a-- 0-20 feet Water table No. X03-N No. N03-N Und use sampled - sampled Mean Range lb./acre mg/l. mg/ 1. Virgin grassland .......... 17 90 a 11.5 0.1-19 Dryland farming .......... 21 261 4 7.4 5-9.5 Irrigated land (except alfalfa) ...... 28 506 19 11.1 0-36 Irrigated land (alfalfa) .................. 13 79 11 9.5 144 Feedlots ...................... 47 1,436 33 13.4 0.41 Source: B.A. Stewart, F.G. Viets, Jr., G.L. Hutchinson, and W.D. Kemper. Ni- trate and other pollutants under fields and feedlots. Environ. Sci. Technol. 1:736-739. 1%7. 1 Table 6-26-Nitrate content of soil cores and water beneath various land-use patterns in Colorado. Appendix 6 116 potasium (31). The nutrients can be utilized as fertilizer in crop production, and even under large applications of wastes, crop yields are generally not reduced until the rate exceeds a range of 120 to 240 tons per acre (32). Long before this limit is reached, however, the nutrient with- drawal requirements of most crops will have been satisfied. The surplus of nutrients in the manure then pose serious problems to water quality through runoff and seepage into groundwater. Since land is at a premium in the Chesapeake Bay Study Area, the owner of a livestock operation may not possess enough land to dispose of his wastes without serious impact on the quality of water. b. Solutions: Fortunately, the concentrations of nitrates from feedlots fall off rapidly with distance, as their lateral movement through the soil is slow. There is little evidence of nitrates more than two or three hundred feet from the polluting area (33). Where domestic water supplies are contaminated, therefore, the problem largely reduces to the location and depth of the well. As seen in Figure 6-27, if the source of water is located down the groundwater gradient from the livestock enclosure, pollutants are likely to be picked up, particularly if the well is relatively shallow (Location D). Since feedlots are often located close to the farmhouse, this has frequently been the cause of trouble when nitrate contamination has been found (34). The problem is averted by locating a well up the groundwater gradient from the pollution source and sinking it to a depth sufficient to avoid contaminants (Location A). One of the solutions to the waste disposal problem has been the sale of wastes from concentrated livestock operations to large cropping operations. This involves hig@ labor and transport costs, however, and the practice is frequently not competitive with the use of chemical fertilizer. An alternative solution has been the use of aerobic or anaerobic waste ponds for the purpose of degrading the wastes and reduc- ing the acreage of land required for its safe disposal. The nitrate content of livestock wastes, for example, can be reduced by up to 50 percent in an aerobic waste lagoon, and total solids can be reduced up to 80 percent. (See Tables 6-27 and 6-28. It is expected that the use of waste lagoons will become increasingly important, particularly as public awareness of the problems of nonpoint sources of pollution increases. Appendix 6 117 B N Figure 6-z 7- Location of wells and nitrate contamination from feedlots. Source: R. A. Engberg (1967) Table 6-27-Average reductions of volatile solids, COD, and Kjaldahl nitrogen in 12- to 15-day laboratory aeration studies conducted at two temperatures. Temperature Criteria 24 C 4C Volatile solids reduction ............... 42.3% 20.1% CO-0 reduction (dichromate) ........ 53.6% 24.5% Kjeidahl nitrogen reduction . ...... 43.5% 15.9% Source: Miner, J. R., Farm Animal-Waste Managements. (1972) 4- Appendix 6 118 Table 6-28-Anticipated results of an anaerobic lagoon receiving animal wastes in a moderate climate. Item Effluent compared with influent BOD concentration ......... 70 to 90% reduction Settleable solids ............. Nearly complete removal Total solids ..................... 60 to 80% reduction pH ................................... Little change, remains neutral Ammonia nitrogen .......... Large increase Source: Miner, J. R., Farm Animal- Waste Kanagements. (1971) Another solution to the problem of waste disposal is the technique of mixing dried wastes with hay and silage for feed. The practice, though still in the experimental stage, is confined to poultry and beef waste processing. Such feed supplements have been found to carry no danger of disease, parasites, or carcass quality degrada- tion, and they are competitive in cost with conventional feed. SEDIMENTATION a. Problem: A discussion of the impact of agriculture on the waters of the study area would not be complete unless its con- tribution to sedimentation were mentioned. In addition to nutri- ents and pesticides, enormous quantities of sediment enter those waters each year, and agriculture lands and conversion of crop- land to other uses are the greatest sources. Sediment losses involved in the shift of land from rural to urban use stem from activities such as highway construction, land grad- ing without precautionary measures, and the construction of hous- ing developments. (See Figure 6-28). Also a major source of sedi- ment is untreated ' cropland, as the average sediment loss for this land use is a relatively high 5.5 tons per acre per year. The sediment load interferes with fish production, reduces the capacity of reservoirs, changes the flow of streams, and increases their chances of flooding. 4P Although it is somewhat less a problem on the Delmarva Peninsula than in the rest of the study area overall sediment loads on the Peninsula have been estimated at 2.5 tons per year. (35). Appendix 6 119 M"I _Z' NO Figure 6-2 8- Urban uses displace agricultural lands in the Chesapeake Bay Study Area b. Solutions: Sediment control laws have recently been passed in all three states in the study area and the losses are expected to be considerably reduced in the target period. Since many of the laws involve conservation measures, agricultural runoff volumes are also expected to be diminished. Hence such measures may reduce the level of nutrient and pesticide pollut- ants released into the environment through such runoff. Sediment control measures are expected to be increasingly stringent-during the target period, not only for their value in controlling water turbidity, but for their value in reducing the levels of other agricultural pollutants as well. Appendix 6 120 PROCESSING WASTES Final mention should be made of pollutants emitted during the processing of agricultural products, an activity which often takes place in the region of agricultural production. Since processing most commonly involves the removal of organic matter, the biochemical oxygen demand of wastes emitted is con- siderable. Table 6-29 lists the wastes of various agricultural activities in terms of their five-day biochemical oxygen demand. Of particular significance is the pollution load emitted in the processing of poultry, as it is projected to remain an important and concentrated activity on the Delmarva Peninsula. The effluents, from agricultural product processors should be strictly monitored for their pollutant content. SENSITIVITY ANALYSIS This section explores the effects of varying some of the assump- tions made in the foregoing demand projections. Some cases are easily quantified, such as variations in the rate of irrigation efficiency or in estimates of irrigated acreage. Others, however, are variations whose effects are impossible to gauge precisely, such as changes in the technology of livestock sanitation. In these cases only the general direction of the variations is dis- cussed. POPULATION One of the major shifts in the demographic profile of the United States in recent years has been the sharp decline in the birth rate. This lowered rate would reduce population in the target period from levels estimated with more births, and to take this Appendix 6 121 Table 6,-29 Cstiulmeil willutiul, "inp uf selech4l agriculturul lircK-&Wvtg ijulumtrii-.4 Annual 5AIny 1101) Put'-utild Pnwe-wng pr(Auctilm. Pound-S Pot'laild df@ily BOD 1wr daily 1wipulatiml imiustry MilliOU Data in literature IOU0 16 hiad, oluivulcut. poundi 1000 ib Ittilli"11.4 Conliv.1.4% Apple. 1,218 32 gal 3600 plim RUD ix-r mw uf 2-1. IM). 2j Cial's 13.3 4 1, 0.26 I'vache',; 2,9710 50 gal 2OW ljImn ROD iter Lase of 24 no. 2.1 cuss 8 )69 1.02 Con. 2,36 1 19.5 11) 11013 im-r Rout ow" prtx%@)"A 9.8 63 Q.38 TtiJtIft(tk-.'+ 9,794) U.4 III MM In-'r t'm tmunux'- Imm-emi-.41 '1.2 10 Cautuing, tobtl ... ... ... 1,370 Corti wet milli,ig 10,111K) I Im - 1-2 PE 4.5 133 0.80 prlm-e'@wd 1hrotigh Iltmic PE (1.4'r lim III goml-) dyeiiii; step SiAing 2 I"h-Aizilig %, K iering 101; 4,W) It ".-hilig 17 66 867 5.1-1, hlerverizing limic dy'silig 910 Dairy P0011411 1100 I.T 10,(M 16 mill, '41 1; V A'A Fluid suilk 1. , 1.0 162 1.0 Evaj."-Ifted f1filk I'mis M5 2.25 11.6 11.07 N"ifut ),-v -AL 176 [email protected] 2sj 157 U. 951 Chilld'u. V. he,-.*- 1,1:;7 21.5 23.6 77.6- 0. 17 Clwd-lur whey. dried 241%, of 1, d 111 174 25.0 19.7 0.06 whuy 50'yj Ili WWI 350 ... ZWO 3.0 GAtage chmse 1,421 3SO 161 61.5 0.38 CAUU& CIA.*C Whey 7,5W 350 ... 1.00U 6.0 Ilidw fuld leather 1,300 6W gal 1500 ppin lwr 100 111 bides 81 300 0.10 "Iftughte Aug 1111d packing 59"too 14 111 ROD per 1000 lb live weight 1.1.0 2,300 13.0 Pulier slid pulp %V(XXI pulp m)'Doo 300 Ila BOD per Lost of pulp 150.0 27,000 162 Paper and paper heard !06,600 68 Ili BOD per %on of pupe-r 34.0 9.000 5 1. 110takIes Chipm 7.1 29.3 lb ROD per ton raw I)OtALOCS 14.6 106 0.6f Dehydrated 2.7 71.1111 HOD per Lon raw pbtaIAMS 35.6 93 0.50 Flour and starW 3.2 57.0 Ili BOD per Wit raw putattitmN 2". 5 91 0.5.1 Frozen French fries 5.4 22.0 Ili 11013 liour Vitt raw liotatoc's 11.0 57 I'miltry B':(u) m It, imn Kr mv I-im. 10.0 211215, 1.3 '*oylwau MW 1.7 11, ROD liel 1000 1-61 0.19 0. 1 (1 0.011.3 Sugar mliniug Clum -18,1K)o 5.31 lit BOD wr tami :1.0 1IL41 t.11 lke'L I "wo 6.6 9 11, M t, Wimil mirttriug 130 11 gof '90M I.Jun per 11. W'M.I 267 100 fl.6 Source: S. R. Hoover (1967) Appendix 6 122 into account, a new series of OBERS projections were advanced in 1974. The new projections, entitled Series "Ell, showed reduced levels of population and of the many economic indices which are related to population. In the Chesapeake Bay Estuary Area, the Series E population projections represent a decline from the Series C projec- tions whichamounts to 4.5 percent in 1980, 7.3 percent in the year 2000, and 13.3 percent in 2020, as shown in Table 6-30 Table 6-30 - Series "C" and "Ell population projections, Chesapeake Bay Estuary Area Y 1969 1980 Percen 1/ 2000 Percent 2/ 2020 Percen chanjzei@ change change---@ Series C 7,776,041 9,273,603 19.3 10,850,097 39.5 16,320,028 109.9 Series E 7,776,041 8,8S8,920 13.9 10,343,520 33.0 14,142,280 81.9 Percent change Series C to E -4.5 -7.3 -13.3 I/ Series C projections were used in demand pr ojections in this Appendix 2/ Percent change measured from 1969 total. The effect of a -reduced population would normally be expected to reduce agricultural production demands as well. Coupled with the reduction in population however, is another, more recent develop- ment: the prospect of large scale exports of American agricultural products. If because of a changing political situation the United States becomes committed to exports of its food products to help alleviate a world shortage, the effect of the reduced domestic population will be mitigated and might well be overcome. If exports increase sufficiently, levels of agricultural production might actually rise over levels projected to support a large domestic population, and the use of water in agriculture will increase over the levels projected in this Appendix. Until the export factor can be taken into account more precisely, as it will be in the newest OBERS projections, the effect of a reduced domestic popula- tion on agricultural demand cannot be measured. The reduction should, however, be reflected in the large portion of the rural population which is not connected with farms or farm services - a population analyzed in this Appendix as the nonfarm residual population. The effect of a population reduction depends to a large degree upon its distribution. If the reduced birth rate is largely an urban phenomenon, the effect upon the residual popu- lation will be minimal. If, however, the reduction is evenly Appendix 6 123 distributed or a rural phenomenon, the size of the nonfarm residual can be expected to fall, and its water demand will be reduced accordingly. LIVESTOCK 4.1 In the projection of the livestock water demand, the ratio of the costs of raising livestock to the revenues brought by their sale is of major significance. As the costs of feed increase relative to the revenues farmers receive for the sale of livestock and their products, production is curtailed. Conversely, as the profit margin increases, livestock production increases. In recent years, cost increases have outpaced revenues received for livestock, a situation which forces many livestock producers to curtail or even halt their operations. If the profit squeeze continues into the target period, the level of livestock production and livestock water demands can be expected to fall below the levels projected in this Appendix. Under these conditions trends of increased per capita consumption of livestock products which are implicit in the OBERS projections will be reversed. On the other hand, improvements in the technology of livestock sanitation and the movement toward raising livestock in larger lots and enclosures would tend to increase livestock water use. Improve- ments in sanitation machinery and practices entail a capital outlay which gives the high volume livestock producer an advantage over the low volume producer, insofar as he can spread his investment costs over more animals. The result will tend to accelerate the current movement toward concentration in livestock production. At the same time, the water use rates of livestock raised in concen- trated lots would increase with improvements in sanitation technology, since, as with consumer appliances improvements in sanitation generally involve greater water use. The interaction of cost-related curtailment of production, and sanitation-related increases in livestock water use, will de- termine the deviation of actual livestock water use from the projections presented in this Appendix. IRRIGATION To remain consistent with published state level projections of agricultural production and.acreage, the demand projections in this Appendix 6 124 Appendix were closely tied to the OBERS totals. In contrast to the effects of a population reduction ' however, the effects of a change in the estimated number of irrigated acres can be easily quantified. Alternative projections were made on the basis of opinions of individuals in each of the subareas who were familiar with local agricultural practices. According to some, the OBERS projections overestimate the extent of agricultural activity and irrigated acres in their subarea, while according to others, the OBERS projections underestimate such activity. As seen in Figures 6-29 through 6-34 which chart such divergences, the latter is more often the case. A second source of variation in the irrigation projections is the amount of assumed precipitation. Irrigation needs were projected for extremely dry conditions: the assumed levels of precipitation would be exceeded 8 years out of 10 for field crops and 9 years out of 10 for vegetables and specialty crops. Under more normal conditions of precipitation, the demand for water can be expected to be considerably reduced. Table 6-32 shows, by subarea, the effect of such reductions upon the projected irrigation water demands, and Figure 6-3.5 shows their effect upon the aggregate water demand projected for the study area during the target period. A third assumption whose variation might sharply affect the levels of projected irrigation water is the rate of irrigation efficiency. In the projections in this Appendix, 65 percent of the gross water application is assumed to be utilized by crops, with the rest lost through evaporation or drainage. As the utilization percentage of gross applications drops, more water is necessary to meet crop needs, and, conversely, as it rises, less water is necessary. The rate of irrigation efficiency depends upon a number of factors, including topography, temperature, wind velocity, and soil types. Since it is impossible to exactly predict the figure for large aggregates of irrigated land, the effect of its variation on the amounts of water projected for crop demands is shown in Table 6- 31 Table 6-31 Effect of varying rate of irrigation efficiency on projected irrigation water demand Rate of Percent change in projected Irrigation Efficiency, irrigation water demand .50 +30% .55 +18% .60 + 8% .65 0 .70 - 7% .75 -13% .80 -19% Appendix 6 125 5,000 Million lndivi@uaj_ 3i 750 Gallons Annual 2,500 OBERS Use 1,250 1980 20100 20@0 Figure 6-29-Irrigation Water Demand in Maryland Subarea 3: Projections based upon OBERS Acreage Projections and Individual Acreage Estimates. 15,000 V- Individual Million 11,250 Gallons 7, 5 0 0 Annual BE@S Use 3,750 1980 2@00 2020 Figure 6-30-Irrigation Water Demand in Maryland Subarea 5: Projections based upon OBERS Acreage Projections and Individual Acreage Estimates. 10,000 Million 7,500 OBERS Gallons Annual 5,000 Individual Use 2,500 1980 200 200 Figure 6-31-Irrigation Water Demand in Virginia Subarea 1: Projections based upon OBERS Acreage Projections and Individual Acreage Estimates. KEY ----- Irrigation water demand based upon individual acreage estimates. Irrigation water demand based upon OBERS acreage @@@O B@\E RS projections. Appendix 6 126 300 Million Gallons 225 - Individual 150 - \.@ I Annual OBERS 75 - Use 1980 2000 2020 Figure 6-32-Irrigation Water Demand in Virginia Subarea 3: Projections based upon OBERS Acreage Projections and Individual Acreage Estimates. 8,000 - Million 6,000 - Individual Gallons 4,000 - Annual OBERS 2,000 - Use lgio 2000 20@O Figure 6-33-Irrigation Water Demand in Virginia Subarea 4: Projections based upon OBERS Acreage Projections and Individual Acreage Estimates.. 15,000 Million Gallons 11,250 - Indiv ual,, 7,500 - Annual 3,750 - OBERS Use 1980 2000 2020 Figure 6-34-Irrigation Water Demand in Virginia Subarea 8: Projections based upon OBERS Acreage Projections and Individual Acreage Estimates. KEY Irrigation water dem@,nd based upon individual acreage estimates. Irrigation water demand based upon OBERS acreage projections. Appendi-x 6 127 82:T 9 XT-pueddV - - - - - - - - - - - - - - - - - - - - --- - - - - - - - - - I - - - - - - - - - - - t= z vt w i z C 00 (n Eli rt rp V, Oat Nj C7, 0 0 goo r E;: -I v- Z! Y, !Ir pr !1:1 !, CD W 0 C-+ CD @-t tz Ia. cc S C+ CL (D 0 r!Z Z CS %9 1 P 5 -g p, 15 4'Z 1@ .. .. .. .. .. 0 'S "w oo . r:* 0 15 ZT, ku ** *g *- j -. . !1F M1 4 go E- Z4 !@i 11 o* go --w t@@ CD r ?e 71. 0 19 'ST 0 @J Z:@ go Z@ Figure 6-315 Total water demands, 1950-1970, and pry' ctions to 1980, 2000, and 202a Irrigation estimated for normal and dry yearsYChesapeake Bay Study 1950 1960 19170 1980 2000 2020 ANNUAL WATER USE9 150,000 MILLION GALLONS S dry year dem 100,000. n o rm al y e a r demands 401i I RRIGATIO RRIGATIO Rc, 50,000- 05 . . . . . .. . . . . . . . . .. . ........ E6 F MIT . . . . . . . ........ I - L> 4;4 4,ii-om rr V A A> V A 7V r V L. A A 7 0 A '7 4 A L. f- DOMESTIC,r, .1A If C <4 A% A A A L. A I A7r V &1-1-4 NAVA N A 7 < r < -P4 <7Y V r VA C Dry year irrigation demand is projected assuming 80 to 90 percent chance of precipitation occurrence; normal year irrigation demand is projected assuming 30 year mean level of precipitation. The year 1959 was slightly wetter, and the year 1969 considerably wetter, than the 30 year mean levels of precipitation for summer months in the study area. (Climatological Data, Annual Summary for Maryland and Delaware: 1959, 1969. U.S. Department of Commerce, Environmental Data Service). If the rate of irrigation efficiency varies between 60 and 70 percent, the demand for irrigation water would stay within 8 percent of projected levels. An increase in the efficiency rate to 80 percent, however, would result in a 20 percent reduction in the level of demand, while a fall in the efficiency rate to 50 percent would result in a 30 percent increase in the gross water demand. Other factors which are less susceptible of quantification are variations in the water holding capacity of soils, and in the technology of irrigation. On sandy soils of low holding capa- city, the irrigation water requirement would be slightly greater than that projected assuming a loam soil, and it would be slightly less on clay-loam soils. With respect to technological changes, as irrigation becomes more widespread and the demand for irrigation systems increases, the cost of installing and operating such systems can be expected to fall. The drop in price can be expected to follow not only from economies of large scale manufacture, but from advances in the technology of the systems themselves. Such developments would tend to increase the use of irrigation over levels expected using the current technology. SUNNARY Among the major factors which would tend to reduce the total agricultural water demand in the study area are an increase in the rate of irrigation efficiency, and the presence of more precipita- tion than is assumed in the dry-year projections. Water demand would be further reduced by a decline in the birth rate, affecting both domestic demand and the demand for agricultural products, and by a reduction in livestock production due to profit squeezes. The agricultural water demand in the study area would tend to be increased by a reduction in the rate of irrigation efficiency, by the presence of irrigation conveyance losses.and in areas where sandy soils prevail. The water demand would also be increased by improvements in the technologies of livestock sanitation and of irrigation by exports of agricultural products to foreign countries, and by a redistribution of population to rural areas. Appendix 6 130 CHAPTER IV REQUIRED FUTURE STUDIES In the projection of the residual population, the population served by small central systems was estimated by relating its rate of growth to the rate of growth of small towns. The population served by large systems was projected individually for each system, and the residual remained after these two components were subtracted from estimates of total population. Since the size of the residual is an important part of the projection of rural domestic water use, the reliability of estimates of such water use in this Appendix would be considerably improved if more exact studies of this population were undertaken. Also concerning population, it is important to know the distribution of expected changes: whether birth rates are most reduced in urban areas or in rural areas, where major movements to and from rural areas will occur. In this regard, demographic data per- taining to birth rates among different portions of the population, and to migration within the Study Area, might be profitably analyzed. A study of the age structures in different subareas would also be useful. There is a need for more accurate data concerning water use rates of the residual population. only crude data is currently avail- able pertaining to per capita water use rates: despite the increased use of water-using appliances from 1950-1970, one source lists the rate as unchanged during that period. The accuracy of domestic water use projections would be considerably improved if data pertaining to use rates and factors affecting their growth became available. One of the major needs for agricultural water in the Study Area is the elimination of spot shortages of water, a need especially important to the efficient production of crops. As the solutions Appendix 6 131 to this problem will most likely involve a pooling of resources feasibility and cost benefit studies might well be conducted to bring such projects closer to existence. Such studies would be especially pertinent to the Piedmont region, where availability of ground water is erratic. If central water supplies are to be used in agriculture, studies will be needed as to: a. the areas where agricultural activity is likely to persist, considering both comparative advantage of the area's agriculture and pressures for urbanization, b. the potential sources of water supply in such areas water impoundment, ground water, or stream--which can supply the needs of surrounding farms, and C. the least cost location of the source of supply. In addition, the costs of community supply from streams or from a location where ground water can be obtained should be estimated, as they affect the individual farmer who utilizes the service. Such central services will be important if the value of fertile farmland is not driven down--because of spot shortages of water-- to the point where it cannot compete.with other land uses. A program of studies is needed which directly correlates water quality with agricultural practices in the Chesapeake Bay Study Area. Such studies have been successfully undertaken in other areas of the country such as California, Texas, Missouri, and Alabama. Many of the factors which affect the environmental impacts of agri- culture, however--such as topography, soil types, and precipitation-- are location specific. The results of studies which directly apply to conditions in the Chesapeake Bay Study Area would thus be of greater reliability than the results of studies conducted elsewhere in measuring the extent of agricultural impacts on the environment. The accurate measure- ment of the extent of agricultural impacts on the Chesapeake environ- ment is a necessary step in seeking appropriate and reasonable levels of control consistent with agricultural production goals. Appendix 6 132 Finally, the hydraulic model constructed in connection with the Chesapeake Bay Study may be of some use in tracing the flow of materials associated with agricultural runoff - notably, sediment, agricultural wastes and nutrients, and pesticides. Problems would be posed in such an endeavor by the dispersion and locational interminacy of agricultural activity. Unlike industrial waste sources, the source of potential agricultural pollutants is diffi- cult to pinpoint, since not only does the location of a type of farming shift, but agricultural pollutant sources within a given area shift as well. Despite this drawback,, the magnitude of agricultural impacts upon the environment are such that such a study would be a useful effort. The drawback may be overcome in several ways. Historical levels of agricultural production at the subarea level may be varied and the effects of the variation upon the impacts traced. Percentages of pollutants which reach the waterways may be also varied, to explore the effects of pollutant regulation. (Since programs which regulate agricultural pollutants are in their incipient stages, a measure of their effectiveness may be thus determined using the hydraulic model). Subareas on the Delmarva peninsula are characterized by high levels of agricultural activity and, in some places, poor drainage: more exacting breakdowns of agricultural activity, and the potential flow of its pollutants from various agricultural activities might be justified for these subareas. Alternatively, existing data could be used, in connection with the hydraulic model, to identify the source of existing flows of agri- cultural pollutants. Working backward from effect to cause, the sources of current pollutants may therefore be more effectively monitored. This would be useful not only from the point of view of regulatory agencies, but, since the levels of livestock production and nutrient and pesticide applications can be determined for the source areas, a more exact relationship could be developed linking agricultural activity with its impact upon the Bay. Such a relation would be valuable too in projecting the impact of future agricultural production more exactly than was possible for this Appendix. By continually linking agriculture-related pollutants in the Bay system with the known levels of agricultural activity, the actual effects of regulation, of shifting agricultural activity, and of changing technologies can be estimated as the changes occur. This information would be valuable in assessing the economic and environmental trade-offs associated with alternative water quality standards, various regulations and control methods, and practices that could be used. Appendix 6 133 AGRICULTURAL WATER SUPPLY FOOTNOTES (1) In 1950, for example, 40% of the total population in the United States was rural, and 60% urban. By 1960 the rural population was dropped to 37% and 63% was urban, and in 1970 the population distribution was 26% rural and 74% urban. It should be noted that some of the change in population in 1970 was due to a new urban placp definition. (2) See Chesapeake Bay Study Existing Conditions Report for definition of Chesapeake Bay Estuary Area. (3) On the national level, evidence of this movement is seen in the decrease of the farm population from 23.0 million, or 15.3 percent of the total population in 1950 to 9.7 million, or 4.8 percent of the total population in 1970. The farm population in 1970. (4) The Land, Resources and Use. Chesapeake Bay Study Existing Conditions Report, Appendix B, Volume I. (5) See Conservation Needs Inventory (1967) published by Maryland and Delaware. Total potentially irrigable acres do not include acres presently irrigated. (6) U. S. Water Resources Council: OBERS Projections, Vol. 1: Concepts, Methodology, and Summary Data. Washington, U.S. Water Resources Council, 1972. (7) Ibid. (8) Ibid. (9) There is cited in support of these assumptions "the known reserves of potential cropland." Since the date of the OBERS projections, however, these reserves have been released and there have been both shortages and increases in the price of food relative to other consumer products. (10) The projections were accomplished using the Spillman func- tion. The average per farm population was not expected to fall below 2.5 persons. (11) Estimated Use of Water in the United States: 1960, 1970. United States Geological Survey Circulars 456 and 676. Appendix 6 135 (12) In this functionJ when water use is 40 gpcd, the annual rate of increase is 30 percent. When the use rate increases to 80 gpcd, the rate of increase drops to 1.0 percent, and it tapers off to 0.5 percent when the use rate is 150 gpcd is reached. This relation, used by the Corps of Engineers in the projection of use rates of the population served by central systems, was first developed for the Ohio River Basin Framework Study, U.S. Department of the Interior, Federal Water Pollution Control Administration, 1963. Assuming continuous compounding, use rates may be projected, through an integration procedure, from the equation, UT IT .3.735966) + U 0 1.279948] .781282 where UT = use rate at time T U = base rate at time T 0 0 T = elapsed time, in years from base year T 0* (13) See Chesapeake Bay Study Future Conditions Report, Appendix 5; Municipal and Industrial Water Supply for details of pro- jection procedure for small systems served population. (14) To project water demand for smal 1 systems, an estimated 1970 use rate of 100 gallons per capita per day (gpcd) was judged appropriate, roughly 85 percent of which would go to non- industrial uses. See Chesapeake Bay Study Future Conditions Report, Appendix 5: Municipal and Industrial Water Supply for details of projection procedure for small systems water use rate. (15) Geological Survey Circular No. SS6. Estimated Use of Water in the United States, 1965. (16) A notable exception is the case of broilers, whose assumed ninety-day market cycle would not permit maturity. The water use rate per bird, when averaged over the ninety days, is significantly lower than the water use rate reported for mature birds in the U.S. Geological Survey. (17) In the OBERS projections, 1964 was the most recent historical date in the trend. (18) The procedure by which the limits are set is well documented in the methodology statement of the OBERS report. OBERS Projections, Vol. 1: Concepts, Methodology, and Summary Data. Washington, U. S. Water Resources Council, 1972. Appendix 6 136 (19) The estimated irrigation water demand of nursery and specialty crops is based upon individuals' estimates of nursery and specialty acreage in their subareas. Included in this category are nursery stock, golf courses, and other miscellaneous crops not addressed in the OBERS projections. (20) See Sensitivity section for effects of varying this assumption. (21) U. S. Census of Agriculture, 1969. Volume II: General Report. Chapter 9: "Irrigation and Drainage on Farms." (22) In the State of Virginia, where most farm ponds are in the coastal plain and Piedmont Provinces, ponds were constructed at a rate of 1200 per year in the decade from 1960 to 1970. See Water Resources Report: Opportunities for Virginia Agriculture (1969). (23) Table 6-21 shows the importance of soil texture in drought, since the effect of a sandy soil with poor holding capacity is much the same as the effect of reduced root length. (24) J. S. Robins and C.E. Domingo, "Potato Yield and Tuber Shape as Affected by Severe Sub-Moisture Activity and Plant Spacing." Agronomy Journal, 48 (1956). (25) See Appendix 5 of the Future Conditions Report; MuniciDal and Industrial Water Suppl for detail. (26) In ground water supplies the rate of intrusion is quite slow. It has been estimated that if withdrawals totaled 1-1, mgd at Dover, where the aquifer, thickness, at 30 percent porosity, is 200 feet, it would take 7000 years for the nearest saline water to move 12 miles to the pumping center. (See Water Resources of the Delmarva Peninsula, U. S. Geological Survey Professional Paper 822. (1973). (27) J. R. Miner, "Agricultural Waste Management," (1974). (28) See Amendments to the Federal Water Quality Act. Public Law 92-SOO, 92nd Congress S.2770 (1972). (29) B. A. Stewart, "A Look at Agricultural Practices in Relation to Nitrate Accumulation," (1970). (30) See Amendments to the Federal Water Quality Act. Public Law 92-500, 92nd Congress S.2770 (1972). (31) George E. Smith, "Land Spreading as a Disposal Process," (1968). Appendix 6 137 (32) B. A. Stewart and A.C. Mathers, "Soil Conditions Under Feedlots and on Land Treated with Large Amounts of Animal Wastes," (1971). (33) George E. Smith, "Nitrate Pollution of Water Supplies," (1969). (34) Ibid. (35) North Atlantic Regional Water Resources Study Coordinating Committee. North Atlantic Regional Water Resources Study. Appendix Q: Erosion and Sedimentation, (1972). 71 Appendix 6 138 AGRICULTURAL WATER SUPPLY REFERENCES Articles Engberg, R.A. The Nitrate Hazard in Well Water. Nebraska Water Survey Paper 21. Lincoln: University of Nebraska Conservation and Survey Division. 1967. Goldberg, Marvin C. "Sources of Nitrogen in Water Supplies." In Agricultural Practices and Water Quality (Willrich and Smith, eds.). Ames: Iowa State University Press. 1970 Herron, G.M., Terman, G.L. Drier, A.F., and Olson, R.A. "Residual nitrate nitrogen in fertilized deep loess- derived soils." Agron. J. 60(1968). pp. 477-482. Hoover, Sam R. "Agricultural Processing Wastes: Magnitude of the Problem." In Agriculture and the Quality of Our Environ- ment. Washington: American Association for the Advance- ment of Science, 1967. Kilmer, V. J., Gilliam, J. W., Lutz, J. F., Joyce, R.T., and Eklund, C. D. "Nutrient Losses from Fertilized Grassed Watersheds in Western North Carolina." In J. Environmental Quality, Vol. 3, No. 3 (1974), p. 214-219. Miner, J. Ronald (Ed.). Farm Animal - Waste Management. Ames: Iowa State University, North Central Regional Publication 206. 1971. Miner, J. Ro nald. "Agricultural Waste Management." In Journa I of the Environmental Engineering Division, Proceedings of the American Society of Civil Engineers. Vol. 100, No. EE2 (April, 1974). pp. 363-368. Nicholson, H.P. and Hill ' D.W. "Pesticide Contaminants in Water and Mud and Their Environmental Impact." In The Relation- ship of Agriculture to Soil and Water Pollution. Pro- ceedings of the Cornell University Conference on Agri- cultural Waste Management. January, 1970. Smith, George E. "Nitrate Pollution of.Water Supplies." Paper presented at 3rd Annual Conference on Trace Substances in Environmental Health, Columbia, Missouri, June, 1969. Appendix 6 139 Stewart, B.A. "A Look at Agricultural Practices in Relation to Nitrate Accumulation." In Nutrient Mobility in Soils: Accumulation and Losses. Madison Soil Science Society of America, Inc. 1970. Stewart, B.A., and Mathers, A.C. "Soil Conditions Under Feedlots and on Land Treated with Large Amounts of Animal Wastes." Symposium on Identification and Measurement of Environ- mental Pollutants, Ottowa, Canada. June 14-17, 1971. Stewart, B.A., Viets, F.J., Jr., Hutchinson, G.L., and Kemper, W.D. "Nitrate and Other Pollutants Under Fields and Feedlots." Environ. Science Technology 1 (1967): p. 736-739 Stewart, B.A., Viets, F.G., Jr. and Hutchinson, G.L. "Agricul- ture's Effect on Nitrate Pollution of Groundwater." Journal Soil and Water Conservation 23 (1968): p. 13-15. Timmons, D.R., Burwell, R.E. and Holt, R.F. "Loss of Crop Nutrients Through Runoff." Minnesota Science 24 (1968). Government Publications Federal Water Pollution Control Administration. Water Quality Criteria: Report of the National Technica-1 Advisory Committee to the Secretary of the Interior. Washington: 1968 General Resources Task Force of the Virginia Commission of the Industry of Agriculture. Water Resources R22art-. Opportunities for Virginia Agriculture 1969. Maryland Geological Survey. Water in Maryland. Educational Series No. 2 1970 North Atlantic Regional Water Resources Study Committee. North Atlantic Regional Water Resources Study. May, 197277. U.S. Department of Agriculture, Economic Research Service. Monthly Precipitation Probabilities by Climatic Divisions: 23 Eastern States. Miscellaneous Publication No. 1160. 1969. Christensen, Lee A. The Economic Base of the Southwest Wisconsin Rivers Basin with Emphasis on the Agricultural Sector. USDA, ERS Reference Report No. 13. 1970. U. S. Department of Agriculture, Economic Research Service. A Simulation of Irrigation Systems. Technical Bulletin f431. (Revised). 1974. Appendix 6 140 U.S. Department of the Army, Baltimore District, Corps of Engineers. Chesapeake Bay Existing Conditions Report. Baltimore. 1973. U.S. Department of Commerce. Census of Agriculture: 1949, 19S4, 1964, 1969; Census of Housing: 1950, 1960, 1970; Census of Population: 1950, 1960, 1970. U.S. Geological Survey. Estimated Use of Water in the United States: 1950, 1955, 1960, 1965. U.S. Geological Survey, in cooperation with Maryland Geological Survey. Extent of Brackish Water in the Tidal Rivers of Maryland. Report of Investigation No. 13. 1970. U.S. Geological Survey. Water Resources of the Delmarva Peninsula. Professional Paper 822. Washington: 1973. U.S. Water Resources Council: OBERS Projections: Economic Activity in the United States. Washington, 1972. Appendix 6 141 AGRICULTURAL WATER SUPPLY GLOSSARY agricultural production production of 1) assorted c 'rops and vegetables and 2) livestock including poultry and milk cows. aquifer: a water-bearing stratum of permeable rock, sand, or gravel. breeder numbers: the stock of animals needed to re-establish the marketed population after sale. ceiling/base values: limits within which a projected value is expected to fall. For use in a Spillman extrapolation. control totals: A future estimate for an area which is to be allocated among subareas using the shares technique. demand derived numbers: livestock numbers projected by dividing estimated livestock weight demands by average weights of livestock. distributional effect: the shift in regional or subarea pro- duction which is due to a shift in distri- bution relative to others' production. farm ponds: a. Impoundment: A natural depression backed by an earth filled dam, designed to capture surface runoff and to store it for times of shortage. b. Dug: A large shallow pit, usually ten to fifteen feet in depth, which taps the ground water reservoir. kg/ha.: killograms per hectare, equal to approximately 1.21 pounds per acre. Appendix 6 143 land-capability classifications: An interpretation of soil informa- tion made primarily for agricultural purposes. The first four classes are capable under good management of producing adapted plants, such as forest trees, and the common culti- vated field crops and pasture plants. Class I. Few limitations that restrict their use. Class Il. Some limitations that restrict the choice of plants or require moderate conservation practices. Class III. Severe limitations that reduce the choice of plants or require special conservation practices, or both. Class IV. Very severe limitations that restrict the choice of plants, require very careful management, or both. large water supply system: central water supply systems serving more than 2500 people. mgd: million gallon per day mg/l.: milligrams per liter mho: the meter-kilogram-second unit of electric conductance, equal to the conductance of a conductor in which a potential difference of one volt maintains a current of one ampere. micromho (i4mho): one millionth of a mho. millimho (mnho): one thousandth of a mho. mortality numbers: livestock which are not expected to reach marketable age. state effect: the effect upon subarea pro'duction of increases in production at the state level. OBERS projections: projection of economic activity accomplished by the Bureau of Economic Analysis, the U.S. Department of Commerce, and Economic Research Service, U. S. Department of Agriculture. Appendix 6 144 residual population: population not served by central water supply and sewage systems. rural population: "Rural" population is defined by the 1970 Census of Population as "that portion of the population not classified as urban." Urban population is defined as "all persons living in - a) places of 2SOO inhabitants or more incorporated as cities, villages, borouglis (except Alaska), and towns (except in the New England States, New York, and Wisconsin), but excluding those persons living in the rural portions of extended cities; b) unincor- porated places of 2500 inhabitants or more; and c) other territory, incorporated or unincorporated included in urbanized areas. shares analysis: technique for estimating futute subarea pro- duction whereby a control estimate of an area's production is disaggregated among subarea in accordance with the trends exhibited by the subarea shares in the past. small water supply system: central water supply systems serving fewer than 2500 people. Spillman projection function: function used in the projection of economic activity, which permits pro- jected value to vary, within limits, along a curvilinear trend. subarea: a grouping of counties for projection purposes. Com- position of Chesapeake Study subareas is listed in Table 6-1, and illustrated in Figure 6-1. 41 Appendix 6 145 ACKNOWLEDGMENTS Principal author of this Appendix was Mark A. Helman; John W. Green was responsible for the section on historical water use; James E. Horsfield and John E. Hostetler contributed to portions of the entire report and provided overall guidance. WATER QUALITY AND SUPPLY, WASTE TREATMENT, NOXIOUS WEEDS TASK GROUP, CHESAPEAKE BAY STUDY AGRICULTURE ENERGY RESEARCH AND DEVELOPMENT ADMINISTRATION Dr. John E. Hostetler Economic Research Service Mr. Charles L. Osterberg 1974 Sproul Road, 4th Fl. Manager Broomall, Pa. 19008 Environmental Programs Division of Biomedical and COMMERCE Environmental Research Energy Research and Development Dr. Robert Hanks Administration Plans and Policy Division Washington, D.C. 20545 National Marine Fisheries Service 3300 Whitehaven Street, N.W. ENVIRONMENTAL PROTECTION AGENCY Page Building #2 Washington, D.C. 20235 Mr. Thomas H. Pheiffer (Chairman) Annapolis Field Office Dr. Robert L. Lippson EPA Region III Assistant Coordinator Annapolis Science Center Environmental Assessment Division Annapolis, Maryland 21401 National Oceanic and Atmospheric Administration FEDERAL POWER COMMISSION National Marine Fisheries Service Oxford, Maryland 21645 Mr. Angelo M. Monaco Regional Engineer CORPS OF ENGINEERS Federal Power Commission 26 Federal Plaza Mr. William E. Trieschman, Jr. New York, N.Y. 10007 Baltimore District, Corps of Engr. P.O. Box 1715 Baltimore, Maryland 21203 Appendix 6 147 INTERIOR DISTRICT OF COLUMBIA Mr. C. Gordon Leaf Mr. Arnold Speiser Supervisory Physical Scientist Chief, Planning Division Division of Mineral Resources Water Resources Management U. S. Bureau of Mines Administration 4800 Forbes Avenue Department of Environmental Pittsburgh, Pennsylvania 15213 Services Presidential Building Mr. W. F. White 415 12th Street, N.W. District Chief Washington, D.C. 20004 Water Resources Division U. S. Geological Survey MARYLAND 8809 Satyr Hill Road Parkville, Maryland 21234 Mr. Albert E. Sanderson, Jr. Water Resources Administration NAVY Tawes State Office Building Annapolis, Maryland 21401 Mr. Carl Zillig Code 1045 Mr. Noel C. Valenza Naval Facilities Engineering Command Public Health Engineer Washington, D.C. 20390 Maryland Department of Health and Mental Hygiene TRANSPORTATION 610 North Howard Street Baltimore, Maryland 21201 LTJG Joseph F. Miante III Marine Inspection Office Mr. Charles K. Rawls U. S. Coast Guard Natural Resources Institute Custom House Chesapeake Biological Gay and Lombard Streets Laboratory Baltimore, Maryland 21202 Box 38 Solomons, Maryland 20688 SUSQUEHANNA RIVER BASIN COMMISSION PENNSYLVANIA Mr. Robert J. Bielo Executive Director Mr. Richard M. Boardman Susquehanna River Basin Commission Chief., Division of Water Quality West Shore Office Center Department of Environmental 5012 Lenker Street Resources Mechanicsburg, Pa. 17055 P.O. Box 90 Harrisburg, Pennsylvania 17120 DELAWARE VIRGINIA Mr. Frank Moorshead Supervisor, Water Supply Section Mr. Michael A. Bellanca Department of Natural Resources Director, Bureau of Surveillance and Environmental Control and Field-Studies D Street and Legislative Avenue Virginia State Water Control Dover., Delaware 19901 Board P.O. Box 11143 Richmond, Virginia 23230 Appendix 6 148 VIRGINIA (Cont'd) Dr. Michael E. Bender Chairman Department of Ecology Pollution Virginia Institute of Marine Science Gloucester Point, Virginia 23062 Mr. E. T. Jensen Executive Secretary Virginia State Water Control Board P.O. Box 11143 Richmond, Va. 23230 Appendix 6 149 Attachment A: Projection By Shares Analysis- Graphical Illustration. .4@ r Appendix 6 151 Attachment A. This Attachment gives a graphical illustration of the share project- ions used in this Appendix. First a situation is examined in which only the change in pro- duction at the state level bears upon the subarea's production. Where RT.' RP STJ and SF represent production in the subarea and state, respectively, at times T (present) and F (future), R F T T) - R SF@, the state's rate of production growth, is applied to VS-T ) production in a subarea at the base time T. This implies that R R F -ST T) - SF or that the subarea's share of state production remains constant from time T to time F, as seen in Figure 6-A-1 Figure 6-A-1 RT Subarea share S of state T production T Time Now a distributional effect--the shift in production toward one subarea over others--is introduced. Let RA represent the quantity a subarea produces over or under the production attributed to the national effect. Appendix 6 152 R S F@ R + R F I w-1 T A \OT/ RF SF + RA . SF T '@F which may be put in terms of state production in the future at F as 4@ RF= (RT + RA) - SF _gT (SF This equation, which expresses regional production as a share of the projected state production, is fundamental to the method of projection employed in this Appendix. All subarea production estimates for the target period were derived by projecting the subarea's share--the term in brackets-- and applying it to the published OBERS state totals. Its share at time T, (@RT), when multiplied by S , yields the regional production at F F T accounted for by the state effect. The change in the region's share (RA when similarly multiplied, indicates the distributional effect. SF)' (See Figure 6-A-2 Figure 6-A-2. 101 R SF Subarea share of state production T ST T F Time JRTN rST Appendix 6 153 .4, 11W Attachment B: Rural Population Dwelling Unit Analysis--Tables. _,i_ Appendix 6 155 Attachment B. Table 6-B-1--Rural nonfarm dwelling unit analysis, by state and subarea, 1950, 1960 and 1970, Chesapeake Bay Study 1950 1960 State and W/running W/running W/running W7-running subarea Total water, Per- water, Total water, Per- water, toilet-bath cent toilet-bath toilet-bath cent, toilet-bath --- Dwelling units--- --Population-- ---Dwelling units--- --Population-- CHESAPFAKE BAY 251,833 110,277 43.79 371,961 359,735 2499626 69.39 828,212 DELA14ARE 12,356 6,543 52.95 17,052 20,444 14,382 70.35 33,541 MARYIAM 132,971 69,270 52.09 230,564 187,003 138,324 73.97 452,934 Study Area I---------- 599284 34,401 58.03 118,768 83,472 67,851 81.29 230,956 2---------- 21,240 8,903 41.92 25,376 31,001 20,713 66.81 59,532 3-------- -: 199701 7,364 37.38 19,734 26,783 15,388 57.45 41,645 4---------- 18,755 119721 62.50 44,869 24,898 19,554 78.54 74,719 5---------- 13,991 6,881 49.18 21,817 20,903 14,818 70.89 46,082 VIRGINIA 106,506 34,464 32.36 124,345 152,288 96,920 63.64 341,737 Study Area 1---------- : 11,126 3,296 29.62 109184 15,753 7,075 44.91 18,025 2---------- : 24,131 5,387 22.32 20,301 26,437 20,209 76.44 85,398 3---------- : 5,620 2,435 43.33 8,349 10,210 6,407 62.75 21$247 4---------- : 20,127 7,990 39.70 31,961 32,405 24,421 75.36 92,616 5---------- : 14,733 4,599 31.22 13,104 21,717 11,037 50.82 30,582 6---------- : 2,990 1,368 45.75 4,820 4,422 3,505 79.26 12sO54 7---------- : 10,904 4,802 44.41 20,632 13,780 9,730 72.71 36,923 8---------- : 16,875 4,587 27.18 14,994 27,564 14,536 52.74 44,892 Attachment B., Table 6-B-1--Rural nonfarm dwelling unit analysis, by state and subarea, 1950, 1960 and 1970, Chesapeake Bay Study--Continued 1970 State and W/running W/running subarea Total water, water, toilet-bath Percent toilet-bath ------ Dwelling units ------- --Population-- CHESAPEAKE BAY 412,220 323,682 78.52 1,024,890 DELAWARE 28,123 19,535 69.46 43,994 MARYLAND 216,488 17831256 82.34 576,971 Study Area 1---------- 89,397 80,120 89.62 276,377 2---------- 39,386 28,346 71.97 78,199 3-------- -: 35,217 22,880 64.97 58,942 4---------- 27,065 24,842 91.79 93,066 5---------- 28,423 22,068 77.64 70,387 VIRGINIA 167,609 125,891 75.11 403,925 Study Area 1---------- : 16,834 9,727 57.78 23,892 2---------- : 30,593 27,230 89.01 96,783 3---------- : 14,728 113,751 79.79 37,877 4---------- : 32,170 27,134 84.35 95,547 5---------- : 27,-234 17,086 62.74 44,727 6---------- : 6,916 6,401 92.55 23,299 7---------- : 3,253 2,447 75.22 8,297 8---------- : 35,881 24,115 67.21 73,503 Source: Census of Housing and Calculation. Attachment B. Table 6-B-2--.Rural farm dwelling unit analysis, by state and subarea, 1950, 1960 and 1970, Chesapeake Bay Study 1950 1960 State and W/running W/running W/running W/running subarea Total water, Per- water, Total water, Per- water, toilet-bath cent toilet-bath toilet-bath cent toilet-bath --- Dwelling units--- --Population-- --- Dwelling units--- --Population-- CHESAPEAKE BAY 88,408 28,737 32.50 106,416 48,077 30,857 64.18 115,555 DELA14ARE 5@327 1,839 34.52 6 " 013 3,488 2,469 70.79 8,356 MARYLAND 39,890 15,430 38.68 57,251 23,067 16,167 70.09 61,361 Study Area I---------- 14,160 6,803 48.04 25,456 7,867 6,169 78.42 22,931 2---------- 7,569 2,867 37.88 9,840 4,795 3,535 73.72 12,818 3---------- 7,751 1,968 25.39 65,129 4,187 2,727 65.13 9,364 4---------- 5,250 2,471 47.07 10,175 2,787 1,976 70.90 8,301 5---------- 5,160 1,321 25.60 5,651 3,431 1,760 51.30 7,947 VIRGINIA 43,191 11,468 26.55 43,152 21,522 12,221 56.78 45,838 Study Area 1---------- : 4,505 916 20.33 2,877 2,329 1,418 60.88 4,453 2---------- : 6,182 2,768 44.78 10,578 2,551 1,898 74.40 7,298 3---------- : 3,138 687 21.89 2,455 1,153 639 55.42 2,237 4---------- : 8,302 2,410 29.03 9,458 3,899 2,176 55.81 8,368 5---------- : 8,635 1,833 21.23 6,979 4,437 2,415 54.43 9,364 6---------- : 382 175 45.81 557 117 90 76.92 324 7---------- : 2,527 919 36.37 3,472 1,214 849 69.93 3,233 8---------- : 9,520 1,760 18.49 6,776- 5,822 2,736 46.99 10,561 Attachment B. Table 6-B-2--Rural farm dwelling unit analysis, by state and subarea, 1950, 1960 and 1970, Chesapeake Bay Study--Continued 1970 State and W/running W/running subarea Total water, Percent water, toilet-bath toilet-bath ------ Dwelling units ------- --Population-- CHESAPEAKE BAY 27,459 22,698 82.66 78,223 DELAWARE 1,794 1)634 91.08 5,071 MARYLAND 14,706 12,684 86.25 45,828 Study Area I---------- 5,398 4,786 88.66 16,186 2---------- 3,070 2,730 88.93 9,056 3---------- 2,468 2,145 86.91 8,477 4---------- 1,531 1,281 83.67 4,943 5---------- 2,239 1,742 77.80 7,166 VIRGINIA 10,959 8,380 76.47 27,324 Study Area 1---------- : 693 465 67.10 1,409 2---------- : 1,146 996 86.91 3,194 3---------- : 503 435 86.48 1,479 4---------- : 2,636 2,104 79.82 7,177 5---------- : 2$@245 1,669 74.34 53,140 6---------- 74 64 86.49 227 7---------- 442 401 90.72 1,248 8---------- 3,220 2,246 69.75 7,450 Source: Census of Housing and Calculation. Attachment B. Table 6-B-3--Number and percent of rural population served by running water, by state and subarea, 1950, 1960 and 1970, Chesapeake Bay Study Rural population served Percent served by running water State and by running water subarea 1950 1960 1970 1950 Y 1960 Y 1970 1/ CHESAPFAKE BAY 478,372 943,766 1,101,113 40.65 69.45 79.81 DELA14ARE 23,065 41,897 49,065 46.48 70.44 71.21 MARYLAND 287,813 514,296 62@,799 49.52 74.21 84.55 Study Area 1---------- 144,224 253,887 292,563 55.93 80.97 89.68 2---------- 35,214 72,350 87,255 40.92 68.53 79.02 3-------- -: 25,863 51,009 67,419 32.75 58.86 72.10 4---------- 55,044 83,021 98,009 58.72 77.59 91.25 5---------- 27,468 54,029 77,553 42.50 67.31 78.35 VIRGINIA 167,494 387,573 431,249 30.67 63.91 74.66 Study Area 1---------- : 13,061 22,477 .25,301 41.99 73.37 87.23 2---------- : 30,879 92,697 99,977 26.77 76.90 89.29 3---------- : 10,804 23,485 39,356 35.39 61.90 80.24 4---------- : 41,421 100,984 102,724 36.42 72.50 84.03 5---------- : 20,083 39,946 49,867 26.24 50.16 62.95 6---------- : 5,377 12,378 23,526 45.76 79.20 92.49 7---------- : 24,104 40,155 9,545 43.28 70.59 76.86 8---------- : 21,765 55,451 80,953- 23.14 50.90 67.96 1/ Weighted aggregate percentage obtained by adding number of rural farm and nonfarm households served by running water. Attachment B. Table 6-B-4--Rural population and annual water use, with and without running water, by state and subarea, 1950, 1960 and 1970, Chesapeake Bay Study 1950 1960 State and : With running water Without running water With running water Without running watex subarea : Population Water use Population Water use Population Water use Population Water use Number Mil. gals. Number Mil. gals. Number Mil. gals. Number Mil. gals CHESAPEAKE BAY 478P379 8,730.3 698,.558 2,549.8 943,766 17,223.6 415,245 1,515.5 DELA14ARE 23,065 420.9 26,,555 96.9 41,897 764.1 17,586 b4.2 MARYLAND 287,814 5,252.7 293,437 1,071.0 514,296 9,386.2 178,765 652.6 Study Area 1---------- 144,224 2,632.1 113,629 414.7 253,887 4,633.4 59,675 217.7 2---------- 35,215 642.7 50,835 185.5 72,350 1,320.5 33,220 121.4 3---------- 25,863 472.0 53,115 193.9 51,009 931.0 35,653 130.2 4---------- 55,044 1,004.6 38,700 141.2 83,021 1,515.2 23,972 87.5 5---------- 27,468 501.3 37,158 135.7 54,029 986.1 26,245 95.8 VIRGINIA 167,500 3,056.7 378,566 1,381.9 387,573 7,073.3 218,894 798.7 Study Area 1---------- 13,061 238.3 35,347 129.0 22,477 410.2 25,124 91.7 2---------- 30,879 563.6 84,476 308.4 92,697 1,691.7 27,848 101.6 3---------- jo,804 197.2 19,728 71.9 23,485 428.7 14,453 52.8 4---------- 41,421 755.9 72,300 263.9 100,984 1,843.0 38,304 139.8 5---------- 20,083 366.5 56,466 206.2 39,946 729.0 39,693 144.8 6---------- 5,377 98.1 6,373 23.3 12,378 225.9 3,251 11.9 7---------- 24,104 439.8 31,595 115.4 40,155 732.8 16,729 61.0 8---------- 21,771 397.3 72,281 263.8 55,451 1,012.0 53,492 195.1 Attachment B. Table 6-B-4--Rural population and annual water use, with and without running water, by state and subarea, 1950, 1960 and 1970, Chesapeake Bay Study--Continued 1970 State and With running water Without running water subarea Population Water use Population Water use Number Mil. gals. Number Mil. gals. CHESAPEAKE BAY 1,103,113 20,310.9 265,251 968.2 DELA14ARE 49,065 1,074.5 19,838 72.4 MARYLAND 622,799 11,366.2 113,756 415.2 Study Area 1---------- 292,563 5,339.3 33,670 122.9 2---------- 87,255 1,592.4 23,163 84.4 3---------- 67,419 1,230.5 26,093 95.3 4---------- 98,009 1,788.6 9,401 34.4 5---------- 77,553 1,415.4 21,429 78.2 VIRGINIA 431,249 7,870.2 131,657 480.6 Study Area 1---------- 25,301 461.8 18,145 66.3 2---------- 99,977 1,824.6 11,987 43.7 3---------- 39,356 718.2 9,694 35.4 4---------- 102,724 1,874.7 19,525 71.2 5---------- 49,867 910.0 29,351 107.2 6---------- 23,526 429.3 1,911 7.0 7---------- 9,545 174.2 2,873 10.5 8---------- 80,953 1,477.4 38,171 139.3 > ct C) C+ C+ CD C) n 0 P3 (n0 C+ rt > lid (D 00 lid LA C) ON > r+ r+ tzj C+ (D0 CA ca "Id 0 :31 ct, C+ cn 0 C+ Eg C+ C4 OD -4 C\ \.n -PILA) N) w C: 'In w R) w )> I m 0 04 I'd m :j f7l 9D0 r+ 11411111 fills C+ -4 P' ON @-J N) --4 W ON --4 4:1 00 1 m r . . 0 . L@aP (7\\,O W \0 A) 0:) 0A W )o COW W -PICO w WW CYN k+-n m OD G\ 13% 1 :1 0 M @-j .91 w 110 LAJ \-n 0 N ,.A 00 H M X!, I r- I " 00 -*4 6 Zo @n ZO ;0 !4 ZD Za 6za %) w 0)0 0 pa 1 :3 I-A I (D ct, (7) 0 C+, @-3 m 00 LA.) r \.n LA) LA) \.n 0\ 0,% 'D 0 S OD a\ 3 -91 --4 -PI 00 OD \A w -PI C+ zo 6 ;1 @j za @n ZA 6 DD m H w * @zj * @n !0 r@n po@n I to r. @a tj @n 0 H \,o I-j \,D -4 0:) \.n 0 0 \0 %.n W 0 0 c: e 0 H w U) 00 C/) :3 --4 F\) VI CD W (A) 8\ -PI W C\ C+ \D C\ -P, @- i-j \.n W \.n W -pr \I-j 0 OD H 1@) Zn @0 @n ZY\@D 0 6 6@0 6 !Q @D m 01 0 @-j W OD as 00 N %.A Co W I-a \.n -4 7j '2 1; -PI " ONO 0 00 P, -4 \.n %n a% ?I : C+ 6 @D ZD @) I@n ZA 4- 01 @r-Za -@4 @n V0 m 0 H I%j A) 0 u) W PI .0"\.n \,O U) LA) I a\-4 o \.n P, ow m rio J-j w 00 0 \.n @D 0 w 00 0 A) a\ N 4- Cy\ j W OD w OD pDIZ n \oj' 00 OD -4 48 N) -sr OD 0 c7% w --4 N -wro \.n --4 .1r, U) R) w 0 W 00 --a ro \-n & Fa a w ww I OH 1- 0 \.n W \D w ww 8 '@,n %--,n zn 6 ;YS ZP4, zo @D zn Z7% 6 zo Attachment C.. Table 6-C-2--Daily domestic water use, farm population, by subarea, projections for 1980, 2000 and 2020, Chesapeake Bay Study 198 0 2000 2020 State and Water use Water use Water use Subarea 1-Forulation Per carita Total Population Per capita Total Population Per capita : Total Thousand Thousand Thousand Thousands Gallons gallons Thousands Gallons gallons Thousands Gallons gallons CHESAPEAKE 68.7 55.7 3,823.8 45.0 76.6 3,447.9 32.8 94.8 3,107.8 DEIAWAIRE** 4.9 66.6 328.3 4.0 85.8 345.9 3.5 102.6 358.6 MARYLAND Study Area : 38.8 56.1 2,175.0 25.8 76.4 1,971.3 18.9 94.1 1,778.4 1 - - : 13.2 57.0 750.6 8.3 76.7 637.4 5.8 94.0 541.6 2 - - - - : 7.9 57.3 452.2 5.6 76.9 428.4 4.3 94.1 407.7 3 - - - - : 6.2 56.7 353.3 4.9 76.7 374.9 4.1 94.1 383.6 4 - - - - : 3.9 55.0 215.9 2.0 75.5 152.5 1.2 93.5 109.7 5 - - - - : 7.6 53.1 403.0 5.1 74.8 378.1 3.6 93.2 335.8 VIRGINIA Study Area 25.0 52.8 1,320.5 15.2 74.4 1,130.7 10.4 93.3 970.8 1 - - - - 1.6 49.9 81.7 1.2 72.0 84.9 1.0 91.4 88.5 2 - - - - 2.3 56.4 129.5 1.5 76.4 114.0 1.1 93.9 100.5 3 - - - - 1.3 56.4 74.8 0.8 76.7 57.9 0.5 43.4 4 - - 6.2 53.9 335.2 3.7 75.2 281.6 2.5 93.4 234.0 5 - - 4.9 52.2 256.8 2.9 74.2 217.4 2.0 92.9 189.3 6 - - - - 0.2 56.4 10.4 0.1 76.3 9.2 0.1 93.9 8.0 7 - - - - 1.2 57.6 68.6 0.9 77.o 69.5 0.7 94.1 70.1 8 - - - - 7.2 50.2 363.5 4.1 72.7 296.2 2.6 92.0 237.0 **Sussex County only, at request of.Corps of Engineers Attachment C. Table 6-C-3--.Daily domestic water use, non-farm residual* population, by subarea, projections for 1980, 2000 and 2020, Chesapeake Bay Study 1980 2000 2020 State and Water use Water use Water use Subarea Population Per capita Total Population Per caRita :-- Total Population Per capita Total Thousand Thousand Thousa@d_ Thousands Gallons gallons Thousands Gallons gallons Thousands Gallons gallons CHMPEAKE 864.1 90.5 78,171.5 821.4 107.3 88,167.9 784.2 123.5 96,861.4 DEIAWARE** 62.0 91.1 5,652.3 68.9 107.7 7,416.5 67.8 123.6 8,378.1 MARYIAND Study Area : 368.2 89.8 33,063.4 330.9 106.7 35,288.2 338.1 123.1 41,627.8 1 - - : 181.3 90.7 16,438.7 141.2 107.2 15,132.1 144.2 123.5 17,817.6 2 - - - - : 68.8 89.4 6,152.9 66.7 106.5 7,102.1 63.3 122.7 7,769.0 3 - - : 55.3 89.4 4,944.5 7A. 1 107.0 7,924.0 96.4 123.5 11,898.9 4 - - - - 2.0 67.8 134.8 3.q 97.6 379.6 4.7 118.5 561.2 5 - - - - 60.8 88.7 5,392.5 45.0 105.5 4,750.4 29.5 121.3 3,581.1 VIRGINIA Study Area : 433.9 90.9 39,455.8 421.7 107.8 45,463.2 378.3 123.9 46,855.5 1 - - : 32.7 91.0 2,97-7.5 33.0 107.7 3,556.3 32.4 123.7 4,013.0 2 - - - - : 104.3 92.3 9,626.6 109.0 108.6 11,829.5 105.2 124.4 13,088.3 3 - - - - : 35.9 91.8 3,292.2 35.9 108.3 3,889.7 18.7 124.0 2,314.4 4 - - - - : 83.5 90.4 7,542.6 81.6 107.5 8,773.' 2 78.1 123.7 9,666.3 5 - - - - : 49.2 89.4 4,393.5 51.5 107.1 5,521.3 50.6 123.5 6,251.5 6 - - : 11.9 92.5 1,103.5 4.9 108.2 534.6 5.0 124.2 617.8 7 - - : 34.8 91.9 3,199.1 26.5 107.9 2,858.2 19.8 123.6 2,450.2 8 - - - - : 81.7 89.6 7,320.8 79.3 107.2 8,500.4 68.4 123.5 8,454.0 *Not served by central water supply systems **Sussex County only, at request of Corps of Engineers Attachment C. Table '6-C-4--Daily domestic water use, total residual* population, by subarea, projections for 1980, 2000 and 2020, Chesapeake Bay Study 2000 2020 State and Water use Water use Water use Subarea Population Per carits Tote Population Per capita Total Population Per capita Total Thousand Thousand Thousand Thousands Gallons gallons Thousands Gallons gallons Thousands Gallons gallons CHESAPEAKE 932.8 87.9 81,995.1 866.4 105.7 91,615.9 817.2 122.3 99,969.3 DEIAWARE.** 66.9 89.3 5,980.6 72.9 106.5 7,762.4 71.3 122.6 8,736.7 MARYIAM Study Area : 407.0 86.6 35,238.4 356.6 104.5 37,259.6 357.1 121.6 43,406.5 1 - - : 194.5 88.4 17,189.3 149.5 105.5 15,769.5 150.0 122.4 18,359.2 2 - - - - : 76.7 86.1 6,605.0 72.2 104.2 7,530.5 .67.6 120.9 8,176.8 3 - : 61.5 86.1 5,297.8 78.9 105.1 8,299.0 100.5 122.3 12,282.5 4 - : 5.9 59.3 350.7 5.9 90.0 532.1 5.9 113.5 671.0 5 - - - - : 68.4 84.7 5,795.6 50.1 102.4 5,128.5 33.1 118.2 3,917.0 VIRGINTA Study Area : 458.9 88.9 40,776.1 436.9 106.6 46,593.9 388.8 123.0 47,826.1 1 - - : 34.3 89.1 3,059.2 34.2 106.5 3,641.1 33.4 122.8 4,101.5 2 - - - - : 106.6 91.5 9,756.0 110.5 108-.1 11,943.5 106.3 124.1 13,188.8 3 - : 37.2 90.5 3,366.9 36.7 107.7 3,947.6 19.1 123.2 2,357.6 4 - : 89.7 87.9 7,877.8 85.3 106.1 9,054.9 80.6 122.8 9,900.3 5 - : 54.1 86.0 4,650.3 54.5 105.4 5,738.7 52.7 122.3 6,440.8 6 - : 12.1 92.0 1,113.9 5.1 107.5 543.8 5.1 123.7 625.8 7 - 36.0 90.8 3,267.7 27.4 106.9 2,927.7 20.6 122.5 2,520.4 8 - 88.9 86.4 7,684.3 83.4 105.5 8,796.6 71.0 122.4 8,690.9 @@*Not served by central water supply systems **Sussex.County only, at request of Corps of Engineers > _n V r+ rn rn (D 0 C+ 03 --J 1-4 -n M-, W En C: I- > ..I rD CD tpo co 0) t-I td (D (D rt W LJ t1i t") oll (D C) N) H J., F-- La %D oo N) F- -4 VQ 4-- W F- r.- N.) tj I-n 00 0 00 0 (D 11 10 01 -1- W W 10 V W 10 F- 10 1 10 10 0 (D rQ T-- 1@0 00 N) -j ul CD 00 w -j N) m t-n -P- C> Ul 'D 5 aN as Ln W oo w Ln c% rl) Ln 0 F@ t-n -j oo 4- -j H N 00 0 0 m 0 0 1,0 Ln 1-- 0 Z- co r- t-n LI) all -4 Ul w c 0 -f- ',0 -J H kO 41 LJ T-- "o t.) %0 P. w %D ON %0 F. En 'C. 'L, wW In 'a, '--j 'o, w@- 't,,-, ',o 'a, 1, 'u, "w 'o @j 0 Ln 11.) Un -.j tj F- 4- %D F- F@ Qo 00 a', H aN F" cr, ct .r- -1 f*j "-H N.) %.D w CD -j Ij 4- 4-n oo W t,) -i LI) Ln cm FW C@ ul (D C, CL 0 N@ C) C) .CD 41 Fl tn H N Ln C) H w H %0 00 0 0 1:11. . f- ? ?flYl @4 51 ? f, @4 :4 P, 34 F@ -4 %0 1.0 Lo C) CT% tQ 0 p,@ as w aN -P, 00 00 w (D 0) N) ON " C M Li 00 0 Ili 00 Li 4-1 @10 wrt P)m F- LI) w I'D a@ -i co -i H -j a', O'@ @c m 10H (D rb (DM toW N) F- 0 51 **0 (n F@ N) 00 00 F@ 4-1 -4 1@0 Ln cr r7l w LJ H Ili Ul 4.1 F@ w t1i 4-- Ln t_n I-- N) CD N3 0 rt0 H Ln 9 9: rt -4 H T-- Ln r1i rl 0 -j w F@ m Lo 4-- m %0 rl.) %D Ul m P.m lo w 00 a\ 11 1 1 0 10 w 00 -4 10 00 a, LI) 0 01 0 w 'In a% U.) co LI) 4- --j 00 ui W I-n 00 W %0 C> 0 C+ -j Ul N t.) ON 00 -1 CN w p. w N) 00 1@0 H m (D F- 0 (D W (D @j Ln tQ OD N) w Ln Lo 1.0 F-I @-A w N.) 00 -1 e,:Ij,@n f :11 1@1 f-?, @' @' f @-,;Ij F ID 0 OD co 41 00 00 w -j 110 m all 1.0 CD ON I'D F-- @.o F- c-n -4 00 @,O Ul %,0 as w W 41, 4-1, 0 00 0 00 U.) L@. -i Cs F- k-n I-n W mp, - - C31, -j 00 (D W Fl- 0 0 0 o 0 Li @-o Ln (71 .11 0 Ln fl@ Ul Qo 4-- w a@ w t,.) ON ID H r- H H co F@ -r- IJ ON N) H w ON ON 0 kD 00 4- %0 -t- w "I __j co o 10 ul 0 10 w w 0 t. 03 co o co a% -j 5% op aN Gi ,o co %D ON 00 tn %D .11 w C+ C) w w aN %0 000 -j Li C) 0 I.-n fD FA C:I, CD 0 (D r+ t@: ell e.n W t2l ry m (D 0 @n f" 1+ zr c > OD --4 CY% "Y) Sr W "I r_ n cr t.0) \1 I-j0 Olt 00 P *tu M I M M co A) r\) --3 -P" co -4 @-j H r LA) J-J r\) w Ch \.n Pl i-i \,n OD N) \D --4 -P, a\ 0 @-j 'D \,n r\) \.n _9 --4 M f\) -4 -p, 00 10 @-j 41 w 00 Ic, r)\ 00 w r 1.) OR 8; 2 10 8 r-\,) \Znj -C40 w m cr, M 0 0 rn Fj @-j X- w NJ ra 0\\,n @-j oD \x m) -sr \.n \.n ID z C+ c\\D oww coo o --4 G) %-n .o -4 w P. r%) \0 LJ M LA) W 00 @-n -3 co \In zo zo m R) LA) \-n -P r Foo --j do 00 w C:: co --4 ro \D L43 w \.O H W @-j (D 0 4 C) C+. :3- (D (D C4 9D to w a\ (D W a\ 0% @-j a\ -4 --4 z cr L#J w 11 0 -P, r\) oo a.\ X- X:l oc) @-j W CD ON \.n W 0 H I-j W P' -P' -4 ZD ou m td CA H 0 @@ LA) r \,n )G CY\ \.n oo 0 -prp W O\ \.n w C+ 00 H \0 W \) \.n W -4 F-A \0 0 F@ 0 \0 0 r\) VI Ul 03 ra H w Cl\\,n I-j -4 -j rl) r) \.n 0 ;3 Ct. 00 LA) W CN 00 -P, U) \.n LA) 0 LA) (D M @-j Co% M \0 w 00 -P" ON Zn LA) W M3 ko \-O w La H (7\ 0 8 0 @- \il \n ww 4p- -j 00 \.A 0 -P, -q H r@ L w W 0 0 C+. Ln VA. Fj LA) Ln 0 ww 00 0\ \.n @,O P N) \n -P' W W M rl) :3 W \0 -n OD 0\ U) \10 \0 N) CD M 8\-n*W 03.p,\-n aid \.n \0 -4 -4 N) g r-l (D � -@l @s C', 0 0 rl) 110 9 Lh4l 4 0 OD OD i \0 N) co e lp 0 N) N) -PI, 8 I+D N w ww \9 %10 \-n 0) -4 A) z C+ --4 00 0 H -P, p C\ H 1@0 as OD 0 04 D 0 0 W 1-4 r%) WS &-4 OD \-C W r%) W r \.n @.n 0 w 0 rt) 8 @-j \.n C\ -4 r\) -P, OD %n -4 m 0 \10 -4 \.n C-- 0 0 Attachment C.. TabI6 6-C-7--Sbeep and lambs, numbers and annual water use by state and by subarea, projections for 1980P 2000, and 2020, Chesapeake Bay Study State and 1980 2000 2020 Suberps Numbers Water Use NiTTnb-e r s Water Use Numbers Water Use Thousand gallons Th sand gallons Thousand gallons CHESAPEAKE BAY 19,415 8,851 JA,127 6,717 11,202 5,076 DELAWARE 2,129 975 i,403 667 710 333 W.YLAND 13,899 6.,366 92616 4.,573 7,io4 3,331 Study Area 9.,868 4,480 7,032 3,344 5,345 2,5o6 4,241 1,903 3,205 1,524 2,520 lpl82 3.,911 4791 22936 1',396 2,87 1,072 3 - - - - 445 2o4 138 66 46 22 4 - - - - 1,o67 489 683 325 468 219 5 - - - - 204 93 70 33 24 11 VIRGINIA 2o4,276 93P565 214,928 102.2o6 236,796 111,038 Study Area 7,418 3.,396 5,692 2,7o6 5,147 2,237 47o 215 257 M 146 69 2,2o4 1,010 1.%176 559 657 130 3 - - - - 487 223 292 139 183 86 4 - - - - 399 182 170 81 76 36 5 - - - - 946 433 576 274 368 173 6 - - - - 0 0 0 0 0 0 7 - - - - 281 128 152 72 87 41 8 - - - - 2,631 1,205 3,069 1.,459 3,630 1,702 C+ r+ e! CD rn W cp C+ ;> cl Iz 13 00-4 a%'," W LA)V I 00 1) nzs C+ 0100 1 H co r+ 8 C') go Is 6* of r\) LA) w I-j N) H LA) CO \,n ca H -P, \.n m -cr sr OD N) Ir-W CP\\In Lo t.) OD -Q --4 o \,n \.n o w U) --4 " M LAJ @-j w \.n m CY . . . . . . v w oo -4 (YN 0 @--j f%a H a\ It ID -4 rn 11 L'o \'@n -9 w ro H Nn \20, 8 1 WM f-\-Ol 0 Cb R) rv @-4 z C+ Fl \-n @-J L#J 00 M) \.n R) \,n W OD 0 @A w po r) WN \O-n ?\) @-j 0 --4 r\) -t-n 14 w P8 @-j r+ W 'P, w '0 0 (D La 0-P, --4 SO D \0 0 ID H \.n tTj C- Lo @-n W w -Prl LA) ON \10 --4 (Y\ 11-n w \JD N3 (7\ 03 m OD 0 N) \.n -P, f-j oaw @j co -Arl R) \0 H \@o 0 F\) 0 Q1 .14. w@o w -4 a\ -Pli w FJ N \Jl 0 R) N) @j C+ 0 20D \,O \0 z @j 00 0, 0, W %on IWO Fl -4 0 -4 0 0 CT\ -4 C-4 ro 0 m C+ Uj Lo r I-j I-J Ul :3 (D -P, 01% @-j w CC) W \.n H @-j -P, I-j -P, P. . v @ v @ w w 10 w . V --4 "A Pl N) -PILO C\ \.n R) .n --4 -pl -P, -PI \.n 4- @n C-1 W W &:!@ F-j -gr oc) Co 4:- N) -4 --4 I-j -4 03 to 4-4 \.n vi 0 0 cr\ -Fr -4 w (D 0 0 C+ W 0 --4 LA) w @-j ON --4 @-j w LA) -P, WW\O r \0 41 o n C)a Cr\ W @a LA) Pl W FJ co 43 rQ 0 0 .':'Lo '@o @Dn '8 L\n m 04N8 Wrr ro @-j H \.n ON Cl\ ?1 03 \.n ON J 0 0 ID a) C+ Un :3 ID -4 03 @-j H LA) ro --4 \0 0 00 Q, 00 ro 0 LA) OD @-J 00 N\OW OD a\ 1-n jn \0 X*%Iong@% r\),!@ -4 Uj (I\ \@n -4 H all m C. 0 1-0 .91 0 vl,@o \0 ro --4 \.n 0 LA) OD -P, H 0 :3 Attachment C. Table 6-C-9-- Broilers, numbers and annual water use by state and by subarea, projections for 19802 2000, and 2020, Chesapeake Bay Study State and 1030 2000 2020 Suberea Nurbers Water Use Numbers Water Use Numbers .;ater Use - - - - - - - - - - - - - - - - - - - - - - Thousands - - - - - - - - - - - - - - - - - - - - - - - - CHESAPFAKE BAY: 338,282 506,790 361,248 541,873 374,986 562,479 DEL9.4AM 154,591 231,887 166,o8g 249v134 16gs788 254,682 WYLAND 201,172 301,759 211,o67 316,6oo 215,834 323,450 Study Area 177,882 266,823 193,012 289,517 2o4,,408 3o6,612 I - - 35 53 2 2 P - - - - 4,849 7,273 823 1,234 136 204 3 - - - - 172,998 259,497 192,187 288,28o 2042272 306,408 4 - - - - 0 0 0 0 0 0 5 - - - - 0 0 0 0 VIRGINIA 29,779 44,668 9,897 14,846 3,320 4,980 Study Area 5,8og 8,080 2,147 3,222 790 1,185 1 5,386 8,079 2,117 3,176 788 1,182 P 0 0 0 0 0 0 3 - - - - 0 0 0 0 0 0 4 - - - - 423 1 30 46 2 3 5 - - - - 0 0 0 0 0 0 6 - - - - 0 0 0 0 0 0 7 - - - - 0 0 0 0 0 0 8 - - - - 0 0 0' 0 0 0 *Less than 100 r+ r+ to (/I cn p 0 r+ (D0 C+ En m C+ CN ra 00-4 cr%,..n .01W v I-j %.n 4:,w V W@ i CD 14 1 :4 c) Z$ A3 1C+ C+ :3 :0. lei C:)n bi C-4 r%) L40 --4 W a, 0 LA) SOO W -P' 0 (Y% LA) \.n LA) I-j 0% w @a -91 1.0 ca @-j 0 \.n 0 0\.n 0 %.n ODW H H H 0 ON ra 0 w W 00 \0 0 %lo m @k C+ "n 1" %.n asLA' \0 oN .00 zo 1@0 . . lr@D V 41 W LA) \.n 00 Pl N) \.D w %A C\ 0 ra C+ Co p-4 CY\ \,O \0 4:' oo -P, -4 \.n -P, aN (D *WO 000 0 VI \.n \,n \.O --4 0 110 0 -4 0 (D C4) w 10 m (1) C+ (D bd 0 110 -4 W M M If 03 z OD \.n 0 \.n 00 0) r_u 0*009000cm\ -04 *0 *OOD \.n -pr & C+ C-4 N) F: P, LA) F-I N) \.n LI) C+ LA) (D -4 \0 W W w N. %V 00 LA) N) a\ H 1-4 -13 w U) I'D C@ 0 N) a,% H \.n \.n 0-4 0 0 W 0 0 0\ .91 -P, 0 a\ N) (D 0 C+. 0 rA 0:) 0 L#j 0:) CO 00 CX) P%) ca 0 0 0 0 0 0 000000 0 \0 0 PL) 0 01% P, or\ C+ N) ID 13 H \0 r w 0 H Ul) -n A.n --4 --Q 0 *OOLAJOOOI\) L43 000000 0 ca rn rn En tf) rr, tri fie C+ > Oo -4 a% WW vwOr W V 1-4 9: r+ C6 ct C+ 1 1 1 f I f 00 00 00 .0 00 .0 00 so .0 .6 .0 as .0 00 0 --3 A) F, wLA) -0, W ro N) w 00 ro 0W VI I- \0 to o \.n 0 i3 CD P. 0 0:) -0 "Co rl Iz ID 0 0 I.J i-h 0 C+ N) 'o Fj cr, K) -,o w -p- -P- %0 H m ON M Fj C6 :3 m N) 0 rk) t-A R) \.n W -4 r,3 00 @j (@o R) N) --4 w -P, N) W H \0 N) --4 co -P- OD rO \.n 00 -,1 0- m \,n W W 4,r,.A N) a%" \.n u) Lo -4 OD 6@\W 4 n @--l w $r OD 10 t3l 8 M m 0 r+ 0 C+ 03 ;3 (D :3 .N 4- w 4 PO Fj K) IQ -4 1-1 H ON (7@ Fj -4 K) cy@ C: a, ON @lp @o H -4 --j cy, C06 @o a 0 03 4 W to OD -4 w 0% r@ 4 Pi LA) N) -4 1- N) OD " h) -P, I- \0 0 -4 0 w 0'. %& v " %p Is V 10 W%PV%owlw & \.n W ri) LAI P\. C)N N) f\) g a\.V- .v L*J LAI LIJ 4 C+ cm 0 0 J-h to 03 0 Cf 0 F-i ',13 IQ WF-I V @ p F-J (71 R) o \J, to a, C@ 0 M 0 Attachment C. Table 6-C-12 Future Irrigation Water Requirements State Delaware Subarea No. I Crop :Seasonal 2000 2020 Wet Irrig. :Projected : Seasonal Projected : SeasonaL Frojectea beasurlar. :Requirements: Acres : NIR Acres : N]Ut Acres NIR :(in/ac.) :(ac-ft) : (ac-ft) (ac-ft) 1%'heat Rye Oats Barley Corn (grain) 8.82 1880 647 Is780 1#308 20650 lv948 snags Sorghum(grain): Fruits & Nuts * Vegetables 3.93 36,970 12,9108 hhooso l4s436 5h9820 17,9954 Hay Soybeans 6.22 15,,o4o 7s796 l5s860 .8.,220 15,9780 8sl79 Peanuts Cotton Tobacco Trish Potatoes: l2s92 6,*250 6s,729 6,1570 7,,074 7.,430 8,0000 Sweet Potatoes: Nvz;rsery &Other:. 10,30 7s5OO 6s438 8Y500 7 296 100000 8 0 P *583 Total 1/ 66,640 339718 76,790 38Y334 90,680 l/ Assuming a 65 percent rate of irrigation efficiency, 19 80 2000 2020 gross water demand, in billion gallons per yeai: 16,903 19,217 22,391 Attachment C. Table 6-C-13 Future Irrigation Water Requirements State Maryland Subarea No. I Crop :Seasonal 1960 2000 2020 :Net Irrig. :Frojected:Seasonal Projected : Seasonal Projected Seasonal: .Acres : NIR Acres : NIR Acres NIR :Requirements: (in/ac) : (ac-ft) : (ac-ft) (ac -ft Wheat Rye Oats Barley Corn (grain) 9.47 380 300 400 316 450 355 Silage 7.21 300 180 300 180 320 192 Sorghum (gr) Fruits & Muts: 10-31 90 77 100 86 100 86 Vegetables 4.03 3.9000 19008 3*000 1,0008 3.9000 10008 Hay Soybeans Peanuts Cotton Tobacco IrishPotatoes: SweetPoitatoes: [email protected]: 10.31 5.,000 49296 6,,ooo 5.,155 7#000 6,014 Total 8,770 5,9861 9,800 6s,745 10,870 7s655 l/ Assuming a 65 percent rate of irrigation efficiency, 1980 2000 2020 gross water demand, in billion gallons per year: 2,938 3,381 3,838 4 Attachment C. Table 6-C-14 Future Trrigation Water Requirements State Maryland Subarea No. 2 Crop :Seasonal 1980 2000 2020 :Net Irrig. :Projected Seasonal Projected Seasonal Projected Seasonal :Requirements: Acres NIR Acres NIR Acres NIR (in/ac) (ac-ft) (ac -ft) (ac-ft) 1%'heat Rye Oats Barley Corn (grain) 9,87 39800 3sl25 25vOOO 20,9562 100,1000 820250 Silage 7.34 320 195 3,*000 13,835 12 j, OW 7040 Sorghum (gr) Fruits & Nuts: Vegetables 4.23 9.'000 32173 9080 3006 112000 3,878 Hay Soybeans 7.34 1@0000 612 7.,5oo 4v588 25,,000 152292 Peanuts Cotton Tobacco Ir-ishPotatoes: SweetPotatoes: Nursery&Other:. 11,00 1.,500 1,375 2,0000 10833 2.,500 20292 Total 15,620 8s480 46,880 32,124 150,500 111.9052 l/ Assuming a 65 percent rate of irrigation efficiency, 1980 2000 2020 gross water demand,,in billion gallons pet year: 4,251 16,104 55,671 Attachment C. Table 6-C-15 Future Irrigation Water Requirements State Maryland Subarea No. 3 Crop :Seasonal 1960 2000 2020 :Net Irrig. :Projected.- Seasonal : Projected Seasonal Projected Seasonal :Requirements: Acres NIR : Acres NIR Acres NIR (in/acl :(ac-ft) (ac-ft) (ac-ft) Wheat 9.02 120 90 70 53 50 38 Fqe Oats Barley corn (grain) 9.02 2s130 1,601 4,9230 3s180 59600 42209 Silage Sorghum (grain): Fruits & Nuts 10,46 40 34 20 17 10 9 Vegetables 4.o7 4.s240 1A38 2.,260 767 12190 404 Hay 10.46 450 392 200 174 100 87 Soybeans 6.48 1,0670 902 1,080 583 740 400 Peanuts Cotton Tobacco Irish Potatoes Sweet Potatoes 8.83 70 52 70 52 80 59 Nursery & Other: 10,46 450 392 540 470 650 567 Total 9,170 h9091 81,470 5..296 8,420 5@o773 l/ Ass=ing a 65 percent rate of irrigation efficiency, 1980 2000 2020 gross water demand, in billion gallons per year: 2,051 2,655 2,894 Attachment C. Table 6-C-16 Future Irrigation Water Requirements State Maryland Subarea No. 4 Crop :Seasonal 1990 2000 2020 :Net Irrig. -:Projected:Sea3onal Projected Seasonal Projected 7 Seasonal :Requirements: Acres NIR Acres NIR Acres NIR !(in/ac) :(ac-ft) (ac-ft) fac-ft) Wheat Rye Oats Barley Corn (grain) 10-37 0 0 2,v200 l.'901 2.9630 29273 Silage Sorghum (grain): Fruits & Nuts 11-52 80 77 40 38 20 19 Vegetables 4.33 330 119 480 173 390 140 Hay Soybeans 7.43 0 0 850 526 126oo 991 Peanuts Cotton Tobacco 5.36 900 402 29620 13622 1., 740 1077 Irish Potatoes : Sweet Potatoes : Nursery & Other: 11.52 600 576 2j,500 2.,4oo 89000 70680 Total 1/ 1@910 lj,174 8@690 69660 14,380 129180 l/ Assuming a 65 percent rate of irrigation efficiency, 1980 2000 2020 gross water demand, in , billion gallons per year: 588,487 3,339 6,106 Attachment C. Table 6-C-17 Future Irrigation Water Requirements State Maryland Subarea No. S Crop :Seasonal 1960 2000 2020 :Net Irrig. :Projected: Seasonal Projected Seasonal Projected Seasonal : Acres NIR Acres NIR Acres NIR :Requirements. (ac-ft) :(ac-ft) (ac-ft) : (in/ac) Wheat Rye Oats Barley Corn (grain) 9.11 0 0 32200 2,9429 4,9070 39090 Silage Sorghum (grain): Fruits & Nuts 10-38 5D 43 60 52 80 69 Vegetables 4.01 50 17 100 33 90 30 Fay Soybeans 6.78 0 0 2AO0 1,356 4,52o 29553 Peanuts Cotton Tobacco 4,50 3,650 1*368 16.,560 6.0210 16.,820 6007 Irish Potatoes : Sweet Potatoes : Nursery & Other : 10,38 300 259 li,500 lp298 8sOO0 6.p920 23 820 33,580 Total 1/ 4,050 ls687 11,9378 18,969 1 / Assuming a 65 percent rate of irrigation efficiency, 1980 2000 2020 gross water demand, in , billion gallons per year: 845,583 5,704 9,509 4; Attachment C. Table 6-C-18 Future Irrigation Water Requirements State Virginia Subarea No. 1 :_ - 1280 2000 2020 Crop :Seasonal :Projected :Seasonal Projected - Seasonal Projected : Seasonal :Net Irrig. : Acres KIR Acres NIR Acres : NIR :Requirements: (ac-ft) : (ac-ft) :(ac-ft) (in,/ac) Wheat Rye Oats Barley Corn (grain) Silage Sorghum (grain): Fruits & Nuts : Vegetables 6.71 10,1600 5,v927 7,030 3,931 4..800 2.9684 Fay Soybeans Peanuts Cotton Tobacco Irish Potatoes 11.94 10$900 10.1846 MOO 8.,557 6,,8oo 6#766 Sweet Potatoes Nursery & Other: Total V 21,500 l6s773 15,630 12,0488 113,600 M50 I/ Assuming a 65 percent rate of irrigation efficiency, 1980 2000 2020 gross water demand, in . billion gallons per year: 8,409 -6,260 4,737 Attachment C. Table 6-C-19 Future Irrigation Water Requirements State Virginia Subarea No. 2 1980 2000 2020 Crop :Seasonal :Projected: Seasonal ?rojected: Seasonal Projected : SeasonaL 7 :Net Irrig, Acres : NIR Acres NIR Acres : NIR :Requirements. : (ac-ft) :(ac-ft) : (ac-ft) :(irvac) Wheat Rye Oats Barley Corn (grain) 10.45 240 209 19000 871 10000 871 Silage 7.66 250 16o 1.,100 702 l..100 702 Sorghum (grain): Fruits & Nuts 10.00 400 333 400 333 400 333 Vegetables 2,058 360 89 600 149 600 149 H ay 10.00 200 167 600 500 1.,000 833 Soybeans Peanuts Cotton Tobacco Irish Potatoes : Sweet Potatoes : Nursery & Mer: 10.00 ls500 10250 3,, h 00 2,033 4SOO0 3033 Total 2,950 7,100 8,100 20208 5088 6s221 l/ Assuming a 65 percent rate of irrigation efficiency,. 1980 2000 2020 gross water demand', in , billion- 'gallons per year: 1,107 2,701 3,119 Attachment C. Table 6-C-20 Future Irrigation Water Requirements State Virginia Subarea No. 3 :Seasonal 1980 2000 202Q Crop :Net Irrig. :Prcjected:-3easonal Projected Seasonal Projected Seasonal :Fec--zirements: Acres : NIR Acres NIR Acres NIR (in/ac) : (ac-ft) (ac-ft) (ac-ft) Wheat Rye Oats Barley Corn (grain) 9.6o 80 64 100 80 130 104 Silage Sorghum (grain): Fruits & Nuts : Vegetables 3.03 30 8 30 8 30 8 Hay Soybeans Peanuts Cotton Tobacco Irish Potatoes: Sweet Potatoes: Nursery &Other: 9.64 120 96 300 241 400 321 Total 1/ 230 168 430 329 560 433 1/ Assuming a 65 percent rate of irrigation efficiency, 1980 2000 2020 gross water demand, in billion gallons per year: 84,070 164,881 217,017 Attachment C. Table 6-C-21 Future Irrigation Water Requirements State Virginia Subarea No. 4 :Seasonal 2000 2020 crop :Net Irrig, :.Vrojected:Seasonal Projected : Seasonal Projected Seasonal :Requirements: Acres : MIR Acres : NIR Acres NIR (in/ac) so : (ac-ft) : (ac-ft) (ac-ft) Wheat Rye Oat3 Barley Corn (grain) 8.93 600 446 2.9600 Is 935 29600 lj,935 Silage 6.45 600 322 3s000 1*612 3.,100 1,666 Sorghum(grain)i Fruits & Nuts 8.99 Vegetables 3.18 250 66 300 80 350 93 Hay 8.99 510 382 ls610 ls206 2,0000 1,498 Soybeans Peanuts 1.48 0 0 500 62 600 74 Cotton Tobacco 7.88 1,310 860 1#350 887 1,4oo 919 Irish Potatoes: Sweet Potatoes: Nursery &Other: 8.99 2,640 li, 978 7j,760 5014 9,9600 79192 Total 5,910 4,P054 17,120 10090 19,650 13s377 l/ Assuming a 65 percent rate of irrigation efficiency, 1980 2000 2020 gross water demand, in billion gallons per yeak. 2,032 5,209 6,706 Or Attachment C. Table 6-C-22 Future Irrigation Water Requirements State Virginia Subarea No. 5 Crop :Seasonal 1980 2000 2020 :Net Irr-1g. :Projected: Seasonal Proj=cted Seasonal Projected Seasonal :Requirements: Acres : NIR Acres NIR Acres NIR (in/ac) : (ac-ft) (ac-ft) (ac-ft) Wheat Rye Oits Barley Corn (grain) 9,22 igloo 845 4,900 33765 59000 3,p842 Silage 6.6h 1.'090 603 2,0000 lj,107 2..100 1sl62 Sorghum (grain@ Fruits & Nuts : Vegetables 3.0 900 257 600 172 500 143 Hay Soybeans 7.59 34o 215 730 462 750 475 Peanuts Cotton Tobacco Irish Potatoes : Sweet Potatoes : Nursery & Other-. 9.13 670 510 IMO 12111 22000 19522 Total l/ 4,100 29430 9,690 6s617 10,350 7x144 I/ Assuming a 65 percent rate of irrigation efficiency,, 1980 2000 2020 gross water demand, in., 3,317 3,581 billion gallons per year; 1,218 Attachment C. Table 6-C-23 Future Irrigation Water Requirements State Virginia Subarea No. 6 :Seasonal 1980 2000 2020 Crop *.Net Irrig. :Projected: Seasonal Projected: Seasonal Projected Seasonal 'Requirements: Acres NIR Acres : NIR Acres NIR :(in/ac) (ac-ft) : (ac-ft) (ac-ft) Wheat Rye Oats Barley Corn (Frain) Silage Sorghum (grain) Fruits & Nuts Vegetables Hay Soybeans Peanuts Cotton Tobacco Irish Potatoes: Sweet Potatoes: Nursery &Other: 9.95 60 50 100 42 200 166 Total 77 50 100 42 200 166 l/ Assuming a 65 percent rate of irrigation efficiency, 1980 2000 2020 gross water demand, in., billion gallons per year 25,091 41,709 83,092 1-9 @4 WH 1-30@0 w=-4k]qw wow OW9 0 0 qmilt&OMOMM P. lu IV ;;T C* P. C+ 03 1-4 n, R -"I t- -0s .1 C+ m 9) (A (D EA o)& 0 v M - Uq 0) :3 t- W ID t- m C+ @7- 0 o 0 m C+ C+ :@r aQ CD cr aqo 0 :3 C." CD w m 0 -.%4 "I " III Id 110 0 ca cr � (rQ 0 U) 0 0 @- Re 4 En @-h C: C+ col 03 U) rt El 03 03 z M @-h 0 @-h 0 C+ C+ 4 Z C+ 0 0 0) 03 cm OQ ::r CD (D @-4 Do rt 03 0 0) co 0 0m " 0 4 -.o 1-40 0 M (D M 006 :1 LM 4 C+ 03 r- 0) :03)m .0 co co w 0 " m * 0 z " ww 110 4 0 mQ. "W %A a 1-" 1.- ITI n M CD aq r+ mts :3 03 m m .. .. .. as W (D > C+ r+ as ft r+ tn tj C-J. CD (D CA 0 H. oQ C+ H W CD (D w OQ C+ ::j P, %0 H- r+ OD z 0 C7, 'o 0 H. (ON Ico cn p Ln a) CD 0z W 14P u I@j 0) W rt -3 m 0 CD w C+ 0 N40 0) CD CD I's 0 @-l 0 . 0 0 C-J. 0 41. 00 4 m -,] CD CD 0 :J C+ r+ CD Ln N Ln Q CD w m %D %P Z co 00 =1 H 0 w \.a C+ M z r-r- CY% ONO NO al V oo W N pi m Ul 0 CD 0 4=> 0 co C* CD IZ 00 K) In En 00 40 t-a "i I" 03 \0 C+ 0 Attachment C. Table 6-C-25 .Future Irrigation Water Requirements State, Virginia Subarea No. 8 :Seasonal 2000 202U Crop :Net Irrig, *Projected:Seasonal Projected: Seasonal Projected Seasonal :Requtrements*. Acres : NIR Acres NIR Acres NIR Un/ac) : (ac-ft) (ac-ft) (ac-ft) Wheat Rye Oats Barley Corn (grain) '8.56 19000 713 13.9060 9,9316 8,9000 5,,707 Silage 6.06 360 182 1,9000 505 12000 505 Sorghum (grainj Fruits & Nuts 8.73 30 22 100 3 150 109 Vegetables 3.4o 400 113 500 IV2 300 85 Hay 8.73 180 131 1,0000 728 10000 728 Soybeans Peanuts 7.55 500 315 20000 10258 29$00 1*573 Cotton Tobacco Irish Potatoes: Sweet Potatoes : Nursery &Crther-. 8,73 200 146 860 626 20000 lv455 ToU'l I/ 2P670 10622 18,520 12s648 14,950 100162 l/ As 'suming a 65 percent rate of irrigation effitiency, 1980 2000 2620 gross water demand, in billion gallons per yeai: 812,998 6,340 5,094 ..... . .... 6 ..... .... .77*@ I It 0 WASHI Ain tin Ic N it, 04N: ...UOA. r -b ell, 0(1 fly- it "I,@ dler(d- Wn 46cg 04 rer Qlt -11 I\\- zu Attachment C. J Figure 6-C-1 Total Agricultural J (6 It Water Use; Projections to 1980: A ft Chesapeake S Gnip Bay Study. 0-1999 Million Gallons 2000-5999 6000-9999 10,000-19,999 20,00o 00-IN KC ell WASHIJG: ... ....... . Xmi t X K Xf* .... eqr94N X. r:S dfd Y4 wtp 4 * 4 41 hg A L Flu 7; AttachTqent C. Figure 6-C-2 :14 Total Agricultural Water Use; Projections 0. to 2000: Chesapeake f Bay Study. S Hamp 4r4r lot 0-1999 Million Gallons 2000-5999 6000-9999 10,000-19,999 20,000+ 0 WASH[ io 4, .......... ....... .... .. .. .. 1. W. -otir L Rkk- i klio-, a- .-A Attachment C. 0 Figure 6-C-3 Total Agricultural b ".Fater Use; Projections to 2020: Chesapeake ........ Bay Study. t SHamp X at Million 0-1999 Gallons 2000-5999 6000-9999 10,000-19,999 20,000+ 1 1980 Attachment C. Figure 6-C-4 Annual Domestic Water, Farm Population. Projections to 1980, 2000, and 2020: Chesa.peake Bay Study. X 4-@-: Million 0-40.9 Gallons 41-99.9 100-159.9 160+ 2000 2020 -5: TY-:. VWMA WAS;+j IN Aid ....... At- Attachment C. Figure 6-C-5 Annual Domestic Water Use, 1980 Non-Farm Residual Population. Projections to 1980, 2000J, and 2020: Chesapeake Bay Study. WASHI 0-999 Million x Gallons 1000-2499 01 2500-3999 M If 0 e,za 4000+ 2000 2020 2SIF/ VVASHI WASH +; Ir JI It. Attachment C. Figure 6-C-6 Annual Domestic Water Use, Residual Population. Pro- jections to 1980, 2000, and 2020: Chesapeake Bay Study. . ......... million Gallons WASHI J_ 0-999, 1,000-2,499 _X 2,500-3,999 4,000+ WASHI W-4v WASa-W at Eli Attachment C. 1980 Figure 6-C-7 I/ Livestock Numbers Pro jections to 1980, 2000, and 2020: Chesapeake Bay Study. 14! %N S.".. 0-29,999 30,000-59,999 60,000-99,999 1060,000+ ItExcludes milk cows, poultry; includes backup herds. 2000 2020 SIM OT WAS T @'A X W@ftl I * -7 Attachment C. 1980 Figure 6-C-8 l/ Milk cow Numbers- Projections to 1980, 2000, and 2020: Chesapeake Bay Study. WASmi 1-4999 LEI 5000-9999 10,000-49,999 50,000+ Includes backup herd 2000 2020 woo;-:. @W- WASM WASHI h4f. .p % 4 Attachment C. 1980 Figure 6-C-9 Poultry Numbers. Pro- 2:j jections to 1980, 2000, and 2020: Chesapeake Bay Study. 0-49,999 50 000-99,999 100,000-299,999 @00,000+ 17 11,v, v 2000 2020 A2V WAS;@13(;T N Oc 0'14 k@ .bi. "I, k S -.0 57o:a_@_ 1980 X.- ::,rr... -- Attachment C. Figure 6-C-10 Total Irrigated Acreage; Projections to 1980, 2000, IJ- and 2020: Chesapeake Bay Study. WASHI Acres 1-4999 (Old, 5000-9999 10,000-49,999 50,000-99,999 gill' 100,000+ 2000 2020 U. SHI It MO k3 YI .dw 1980 Attachment C. Figure 6-C-11 ...... .......6 Irrigated Acreage, Food Grains. Projections to 1980, 2000, and 2020: I Chesapeake Bay Study. VM@H-lqw r KEY Acres 1-499 500-999 1000-4999 MON, P 5000+ PETE;ASBUR ORFOLK d Of 2000 2020 T- Pl WASHI GT N OU T WA@ 0 No; A- Y C w 6 -7 Attachment C. 1980 Figure 6-C-12 Irrigated Acreage, Feed Grains. Projections to 1980, 2000, and 2020: .... .. Chesapeake Bay Study. KEY VMS Acres 1-799 DEL 800-999 1000-4999 5000+ 2000 2020 WASHI N 1980 Attachment C. Figure 6-C-13 Irrigated Acreage, Roughage, Projections to 1980, 2000, and 2020: Chesapeake Bay Study KEY Acres 1-499 j6 500- 999 iOOO-4999 5000+ @2000 2u2O 77 V^ IN JI Pf Nonrotic Attachment D: Fertilizer and Livestock Waste Impacts --Tables. Appendix 6 203 Attachment D. Table 6-D- !--Recommended per acre aDplication rates, fertilizer, herbicide and insecticide by crop and yield, Chesapeake Bay Study Crop Yield N P2 05 X20 Lime HerbicidJ/ Insecticide-11 ------- - ---------- - - ----- Wheat --------------- :35 bu. 50 60 60 667 0 0 :50-60 bu. 100 70 70 667 0 0 Rye ---------------- 30 bu. 50 60 70 667 0 0 Corn --------------- 75 bu. 85 60 60 667 2-@ 0 100 bu. 110 80 80 667 2h 0 125 bu. 135 100 100 1,000 211 0 150 bu. 160 120 120 1,000 Vs 0 Silage ----- 12 tons 90 60 90 667 2;j 0 15 tons 112 75 112 1,000 2;j 0 20 tons 150 150 150 1.000 211 0 Sorghum ------------- 90 60 60 667 0 0 Oats ---------- 50 bu. 40 50 50 500 0 0 55 bu. 50 60 60 500 0 0 Barley----------: 50 bu. 50 60 60 667 0 0 Fruits and nuts.!/--: Del.----: 40 41 40 0 24 9 Md.-----: 78 94 25 0 24 9 Va.---: 244 58 53 0 24 9 Vegetables2/__ Del ------ 35 71 70 0 8 5 Md.----: 86 101 100 0 -8 5 Va.---: 30 51 70 0 8 5 Ray- 1-1.5 tons 20 40 40 0 0 0 Soybeans--- 25-30 bu. 10 50 50 1,000 1 0 Peanuts 0 0 31 0 7 3 Tobacco------: 1100 lbs. 40 80 160 500 0 0 1300-1400 lbs. 60 120 240 500 0 0 Irish potatoes--: 175 cwt. 150 200 200 0 16 6 Sweet potatoes---: 350 bu. 75 150 300 250 11 4 *Yield unspecified. 4 l/ Pounds of active ingredients. .j/ For fruits and nuts and vegetables, aggregate application rates were determined from historical use by appropriate state subregion, as listed in Fertilizer Use in the United States, By Crops and Are", 1964 Estimates, Statistical Bulletin No. 408, USDA. 1967. Source: Farm Data Manual, Planning Data for Farming in Maryland, Information Series Number 6, Cooperative Extension Service, University of Maryland. 1970. Attachment D. Table 6-D-2--Annual Fertilizer Requirements, Chesapeake Bay Study: 1970, 1980, 2000, and 2020. 1970 1980 2000 2020 State and Subarea Require- Require- Percent :Require-: Percent - Require--. Percent ment ment Change 1/: ment :Change 11: ment :Change S T Tons Tons Toils lons CHESAPEAKE BAY N- - - - - - - :63,750.9 72,569.8 13.8 74,383.4 16.7 77,582.4 21.7 P205 - - - - - :68,716.5 78,307.3 14.0 76,906.1 11.9 78,758.1 14.6 K2() - - - - - --- 73,223.7 83,487.0 14.0 86,279.6 17.8 82,485.1 12.6 Lime - - - 711,012.3 763,947.9 7.4 765,825.6 7.7 736,763.5 3.6 Herbicide 2@ 2,514.5 2,494.9 -0.8 2,067.1 -17.8 1,898.8 -24.5 Insecticide 2/: 589.7 573.6 -2.7 434.9 -26.3 366.0 -37.9 IEIAWA IE N- - - - - - - 10,971.0 9,375.1 -14.5 10,189.6 -7.1 10,399.0 -5.2 P205 - - - - - 12,824.8 12.824.1 0.0 13,163.2 2.6 13,351.8 4.1 K20 - - - - - - 12,954.9 13,059.0 0.8 13,415.4 3.6 13,329.9 2.9 Lime - - - - - 146,309.2 143,266.7 -2.1 150,366.7 2.8 140,900.0 -3.7 Herbicide 2-1 -: 523.8 462.3 -11.7 469.6 -10.3 477.2 -8.9 Insecticide 2/: 133.5 152.4 14.2 159.1 19.2 168.3 26.1 MARYLAND Study Area W - - - - - - 31,252.1 42,268.8 35.3 47,713.9 52.7 53,436.7 71.0 P205 - - - - -- 31.067.4 39,288.0 26.5 42,295.7 36.1 46,574.7 49.9 K20 - - - - - 32,836.9 41,526.5 26.5 46,087.3 40.4 48,770.3 48.5 Li me - - - - - :309,892.1 344,821.9 11.3 388,127.2 25.2 397,790.6 28.4 Herbicide 2/ -'. 984.7 1,068.0 8.5 944.1 -4.1 923.0 -6.3 Insecticii-e 2/. 190.8 165.2 -13.4 106.9 -44.0 74.0 -61.2 Subarea I I N- - - - - - @-: 7,036.8 8,318.4 18.2 6,630.9 -5.8 5,947.2 -15.5 P205 - - - - -- 6,768.0 7,666i9 13.3 6,162.4 -8.9 5,516.4 -18.5 .KjO - - - - - 7,270.9 8,271.3 13.9 6,958.3 -4.3 6,323.1 -13.0 Lime - - - - - 51,250.4 49,061.5 -4.3 41,603.1 -18.8 41,253.1 -19.5 Herbicide 2 /-- 211.1 199.4 -5.5 149.7 -29.1 119.8 -43.2 Insecticidi@_2 t. 51.4 44.4 -13.6 29.7 -42.2 20.4 -60.3 Subarea 2 N - - - - - - 13,206.0 19,578.4 48.2 22,977.5 74.0 28,917.1 119;0 P205 - - - - - 12,206.6 17,115.3 40.@. 2 19,400.4 58:.9 24,461.7 100.4 K20 - - - - - - 12,435.0 17,524.7 40.9 19,886ol 59.9 24,492.3 97.0 Lime - - - - - 126,873.7 155,137.5 22.3 198,770.,8 56.7 U1,625.0 66.8 Herbicide 2 /-: 395.9 480.2 21.3 469.4 18.6 489.6 23.7. Insecticid;'2 74.8 70.6 -5.6- 50.8 -32.1 36.7 -51.9. Subarea 3 N - - - - - 7,561.7 11,026.4 .45.8 15,153.2 100.4 16,266.7 115.1 P205 - - - - - 8,270.9 10,554.2 27.6 13,086.2 58.2 139515.8 63.4 K20 - - - - -- 8,441.2 10,765.9 27.5 13,688.5 62.2 13,715.3 62.5 Lime - - - - - :98,700.8 106,541.7 7.9 122,078.3 23.7 122,864.6 24.5 Herbicide 2 1-: 296.2 316.1 6.7 279.4 -5.7 279.6 -5.6 InsecticidF 2@ 57.0 44.6 -21.8 23.4 -58.9 14.4 -74.7 Subarea 4 1 N - - .;- - - - 1,707.4 1,511.4 -11.5 1,096.9 -35.8 718.2 -57.9 P205 - - - - - 1,781.9 1,653.8 -7.2 1.160.6 -34.9 810.0 -54.5 K20 - - - - - 2,048.8 1,911.1 -6.7 1,336.4 -34.8 955.8 -53.3 Lime - - - - - 14,175.0 12,819.8 -9.6 8,86lo5 -37.5 6,228.1 -T56. I Herbicide 2 /-: 43.2 36.1 -16.4 20.9 -51.6 13.2 -*69.4 Insecticidg" 2 6.1 4.5 -26.2 2.2 -63.9 1.3 -78.7 Subarea 5 N- - - - - - - 1,739.3 1,834i2 5.5 1,855.5 6.7 1,587.4 -8.7 P205 - - - - - 2,039.9 2,297.9 12o6 2,486.1 21.9 2,270.8 11i.3 K20 - - - - - 2,641.1 3,053.6 15.6 49218.0 59.7 3,283.7 24.3 Lime - - - - -- 18,892.1 21,261.5 12.5 16,813.5 -11.o 15,819.8 -16.3 Herbicide 2 / -: 37.6 36.1 -4.0 24.7 -34.3 20.7 -44.9 InsecticidW 2 A 1.5 1.1 -26.7 0.8 -46.7 1.3 -13.3 Attachment D. Table 6-D-2-- Annual Fertilizer Requirements, Chesapeake Bay Study: 1970, 1980, 2000, and 2020. (Cont.) 1970 1980 2000 2020 State and Subarea '-Require- Require-: Percent Require-: Percent Require-: Percent ment ment I:Change jk ment :Change .1/: ment :Change-11 Tons Tons Tons Tons VIRGINIA N- - - - - - 21,527.8 20,925.9 -2.8 16,479.6 -23.4 13,746.7 -36.1 P205 - - - - - 24,824.3 26,195.2 5.5 21,447.2 -13.6 18,831.6 -24.1 K20 - - - - - 27,431.9 28,901.5 5.4 26,776.8 -2.4 20,384.9 -25.7 Lime- - - - - : 254,811.0 275,859.4 8.3 227,331.7 -10.8 198,072.9 -22.3 Herbfcide 2/-: 1,006.0 964.5 -4.1 653.5 -35.0 498.6 -50.4 insecticid7e- 2/ 265.4 256.1 -3.5 168.9 -36.4 123.7 -53.4 Study Area I _: N- - - - - - 3,515.8 3tO9O.4 -12.1 2,548.4 -27.5 2t218.7 -36.9 P205- - - --: 5,396.8 5,331.1 -1.2 4,659.3 -13.7 4,350.4 -19.4 K20 - - - - - 6,371.4 6,214.7 -2.5 5,666.7 -11.1 5,142.7 -19.3 Lime- - - --: 25,265.4 38,175.0 51.1 39,323.7 55.6 41,743.7 65.2 Herbicide 2/-: 378.8 323.8 -14.5 251.2 -33.7 212.4 -43.9 Insecticide- 2/ 160.2 133.4 -16.7 97.8 -39.0 77.5 -51.6 Study Area 2 * N- - - - - - 2,159.0 1,889.4 -12.5 1,190.4 -44.9 898.4 -58.4 P205- - - --: 2,112.3 2,072.4 -1.9 1,428.2 -R.4 1,136.6 -46.2 K20 - - - - - 2,324.1 2,216.0 -4.7 1,510.7 -35.0 1,176.7 -49.4 Lime- - - --: 14,568.7 10,074.0 -30.9 5,929.2 -59.3 4,158.3 -71.5 Herbicide 2/-: 54.6 37.8 -30.8 21.2 -61.2 13.6 -75.1 Insecticide- 2/ 7.9 6.2 -21.5 4.8 -39.2 3.8 -51.9 Study Area 3 - N - - - - 916.0 953.4 4.1 932.4 1.8 1,110.7 21.3 P205- - - 1,003.2 1,094.7 9.1 1,052.0 4.9 1,360.5 35.6 K20 - - - - - 1,062.0 1,187.8 11.8 1,167.8 10.0 1,361.6 28.2 Lime- - - --: 9.,099.4 9,194.8 1.0 7,975.0 -12.4 8,108.3 -10.9 Herbicide 2/.: 18.9 16.9 -10.6 13.5 -28.6 13.2 -30.2 Insecticide- 2/ 0.7 0.8 14.3 0.4 -42.9 0.4 -42.9 Study Area 4 N- - - - - - 2,615.2 2,457.2 -6.0 2,329.1 -10.9 2,018.7 [email protected] P203r - - - - 2,919.5 3,127.0 7.1 2,859.0 -2.1 2,489.7 -14.7 K20 - - - - - 3.369.6 3,568.5 5.9 3,306.3 -1.9 2,924.4 -13.2 Lime - - - - 31,608.7 35,969.8 13.8@ 32,936.5 4.2 28,883.3 -8.6 Herbicide 2/: 84.4 93.0 10.2 72.9 -13.6 63.6 -24.6 Insecticire 2/ 14.2 17.8 25.4 14.2 0.0 12.5 -12.0 Study Area 5 7 N- - - - - - 5,961.3 6,057.6 1.6 4,933.2 -17.2 4,080.3 -31.6 P205 - - - - 6,632.6 7,292.8 10.0 6,069.5 -8.5 5,079.4 -23.4 K20 - - - - - 6,752.1 7,449.2 10.3 8,779.7 30.0 5,098.3 -24.5 Lime - - - - 89,419.6 94,711.5 5.9 75,652.7 -15.4 63,264.6 -29.2 Herbicide 2/: 157.3 146.1 -7.1 97.8 -37.8 69.5 -55.8 InsecticiCe 2/ 8.6 6.2 -27.9 3.1, -64.0 1.5 -82.6 Study Area 6 N- - - - - - 69.6 95.6 37.4 112.4 61.5 110.1 58.2 P205 - - - - 73.7 94.1 27.7 126.5 71.6 134.6 82.6 K20@- - - - -: 87.1 108.9 25.0 427.7 391.0 135.4 55.5 Lime - - - - 695.0 692.7 -0.3 210.2 -69.8 443.7 -36.2 Herbicide 2/: 3.0 3.5 16.7 3.3 10.0 2.6 -13.3 Insecticide- 2/ 1.0 1.0 0.0 1.0 0.0 0.7 -30.0 Study Area 7 : N- - - - - 2,297.3 2,090.2 -9.0 1,368.4 -40.4 900.7 -60.8 P205 - - - - 2,563.1 2,229.1 -13.0 1,327.9 -48.2 836.9 -67.3 K 0- - 2,638.4 2,257.1 -14.5 1,465.6 -44.5 841.7 -68.1 tK- - 31,449.2 26,787.5 -14.8 13,320.2 -57.6 7,594.8 -75.9 Herbicide 2/: 64.2 48.2 -24.9 24.0 -62.6 15.9 -75.2 Insecticide- 2/ 10.6 6.8 -35.8 3.4 -67.9 3.0 -71.7 Study Area 8 - N- - - - - 3,993.6 4,292.1 7.5 3,065.3 @23.2 2,409.1 -39.7 PZO_ - - - -: 4,123.1 4,954.0 20.2 3,924.6 -4.8 3,443.4 -16.5 K20'3 7- - - 4,827.2 5,899.3 22.2 4,452.5 -7.8 3,704.2 -23.3 Lime - - - - 52,705.0 60,254.2 14.3 51,984.4 -1.4 Herbicide 21: 43,876.0 -16.8 244.8 295.3 20.6 169.7 -30.7 107.8 -56.0 Insecticid-e 21 62.2 84.0 35.0 44.2 -28.9 24.3 -60.9 I/ Percer@t changes from 1970 requirement. 2/ Herbicide and Insecticide measured in pounds of effective ingredients. Attachment D. Table 6-D-3-- Manure production and characteristics per 1000pounds live weight-1/ Dairy Beef Swine : Sheep Poultry Ttem Units Cow Heifer - Sto-c-Fe--F: Feeder Feeder: Breeder* Feeder Layerelroiler :400-700 over 700 lb.: Raw Waste (RW) lb / day 82. 85. 90. 60. 65. 50. 40. 53. 71. Feces/Urine ratio 2.2 1.2 1.8 2.4 1.2 1.0 Total Solids(TS) lb/day 10.4 9.2 11.5 6.9 6.0 4.3 10. 13.4 17.1 % of RW 12.7 10.8 12.8 11.6 9.2 8.6 25. 25.2 25.2 Volatile Solids lb/day 8.6 5.9 4.8 3.2 8.5 9.4 12.0 % of TS 82.5 85. 80. 75. 85. 70. 70. BOD5 lb/day j- 6 1.6 2.1 1.3 0.9 3.5 - % of TS 16.5 23. 33. 30. 9.0 27.0 - COD lb/day 9.1 6.6 5.7 5.2 11.8 12.0 - % of TS 88.0 95. 95. 90. 118. 90. - TKN lb/day .41 .31 .40 .34 .45 .45 .72 1.16 % of TS 3.9 3.4 3.5 4.9 7.5 4.5 5.4 6.8 P lb/day .073 .036 .11 .15 .066 .28 .26 % of TS .7 3.9 1.6 2.5 .66 2.1 1.5 K lb/day .27 .25 .30 .32 .31 .36 % of TS 2.6 3.6 4.9 3.2 2.3 2.1 1/ Actual values may vary from these values due to differences in ration, age, and management practices. 2/ Feces plus urine Source: American Society of Agricultural Engineers, data adapted from Structures and Environment Committee 412 report AW-D-I,, Revised 6-14-73. Attachment D. Table 6-D-4-- Annual Livestock & Poultry, Wastes and Pollutants, Chesapeake Bay Study; 1970, 1980, 2000, and 2020. 1/ 1970 1980 2000 2020 :Percent Pere State and Subarea Pollutant 1 Pollutant Pollutant: Ont :Pollutant : Percent 2 - Change k/. Xhange V : 'Change L/. *Thousand Thousand 9 1 ThousandS I Thounand: Tons I Tons a I Tons t I Tons I CHESAPEAKE BAY Raw Waste- 37,288.8 20,313.4 -45.5 18,854.0 -49.4 18,885.0 -49.4 Total Solids 4,478.6 2,468.2 -44.9 2,292.5 -48.8 2,304.0 -48.6 Volatile Solidi 2,429.9 1,189.6 -51.0 1,073.0 -55.8 1,059.1 -56.4 BOD5 - - - - - 635.1 302.1 -52.4 270.5 -57.4 261.7 -58.8 COD - - - - - - 2,710.5 1,321.9 -51.2 1,189.7 -56.1 1,169.7 -56.8 TKN - - - - - - 193.8 103.3 -46.7 95.3 -50.8 94.8 -51.1 P- - - - - - - 41.2 18.3 -55.6 16.3 -60.4 15.7 -61.9 K- - - - - - 96.7 45.0 -53.5 60.4 -58.2 39.4 -59.3 DELAWARE Raw Waste - - - 2,846.2 1,555.2 -45.4 1,159.8 -59.3 870.0 -69.4 Total Solids -: 348.9 193.9 -44.4 143.1 -59.0 106.7 -69.4 Ralatile Solidi 202.8 118.5 -41.6 95.4 -53.0 72.2 -64.4 BOD - - - - -- 5 54.1 30.7 -43.3 25.0 -53.8 20.0 -63.0 COD - - - - - - 227.5 132.3 -41.8 106.4 -53.2 81.2 -64.3 TKN; -- - - - - - 15.4 8.6 -44.2 6.5 -57.8 5.0 -67.5 P- - - - - - - 3.5 1.9 -45.7 1.5 757.1 1.3 -62.9 K- - - - - - -- 7.9 4.4 -44.3 3.5 -55.7 2.8 -64.6 MARYLAND Raw Waste - - - 20,585.8 11,071.3 -46.2 10,584.5 -48.6 10,805.0 -47.5 Total Solids -: 2,486.0 1,350.7 -45.7 1,289.0 -48.1 1,315.7 -47.1 Volatile Solidi 1,321.8 672.4 -49.1 642.4 -51.4 675.4 -48.9 BOD 5 - - - - - . 331.9 153.6 -53.7 142.3 -57.1 144.5 -56.5 CQD@- - 1,464.6 733.5 -49.9 696.4 -52.5 727.9 -50.3 TJKN- - 105.3 54.5 -48.2 51.5 -51.1 52.0 -5D.6 P- - - - - - - 21.3 8.9 -58.2 8.0 -62.4 8.0 -62.4 K- - - - - - - 51.3 23.9 -53.4 2,2.5 -56.1 23.2 -54.8 Study Are'a 1 Raw Waste- 10,745.8 5,788.3 -46.1 6,060.9 -43.6 6,703.1 -37.6 Total Solids 1,307.3 714.8 -45.3 747.8 -42.8 825.9 -36.8 Ablatile Solidi 671.7 337.5 -49.8 353.7 -47.3 407.9 -39.3 BOD 5 - - - - - : 162.3 72.0 -55.6 72.0 -55.6 80.6 -50.3 COD - - - - - -1 739.2 364.8 -50.6 379.2 -48.7 435.3 -41.1 Ti(N - - - - - - 54.1 27.9 -48.4 28.7 -47.0 31.5 -41.8 P- - - - - - - 10.3 4.0 -61.2 3.9 -62.1 4.3 -58.3 K- - - - - - - 25.5 11.5 -54.9 11.8 -53.7 13.3 -47.8 Study Area 2 Raw 'Waste - - - 5,564.5 3,167.2 -43.1 2,800.2 -49.7 2,618.2 -52.9 Total Solids -: 664.7 381.7 -42.6 336.3 -49.4 314.1 -52.7 Volatile Solidi 374.3 212.0 -43.4 192.3 -48.6 186.5 -50.2 BO - - - - - 92.7 47.4 -48.9 42.4 -54.3 40.3 -56.5 C - - - - -: 413.5 230.6 -44.2 208.5 -49.6 201.5 -51.3 TKN - - - - - - 4- P 28.3 15.5 -45.2 13.7 ---51.6 12.7 -55.1 K 5.8 2.7 -53.4 2.3 -60.3 2.2 -62.1 Study Area 3 14.4 7.5 -47.9 6.7 -53.5 6.4 -55.6 Raw Waste - - - 1,212.8 726.2 -40.1 690.7 -43.0 649.6 -46.4 Total Solids -: 146.7 85.4 -41.8 79.9 -45.5 74.7 -49.1 Volatile Solidi 89.4 46.2 -48.@ 41.1 -54.0 36.3 -59.4 BOD5 --- - - - 28.3 15.1 -46.6 14.1 -50.2 12.6 -55.5 COD - - - - - - 104.1 53.3 -48.8 47.5 -54.4 41.8 -59.8 Tn- - - - - --. P 7.2 4.2 -41.7 4.0 -44.4 3.7 -48.6 K 1.9 1.0 -47.4 0.9 -52.6 0.9 -52.6 3.8 2.0 -47.4 1.9 -50.0 1.7 -55.3 Attachment D. Table 6-D-4-- Annual Livestock & Poultry, Wastes and Pollutants, Chesapeake Bay Study; 1970, 1980 2000, and 2020. (Cont:) 1970 1980 2000 2020 state and Subarea- FPollutan,t -pollutant : Percent @Pollutant i Percent 'Pollutant I Percent 3 Change ;/I schaftse 1/1 tchainge -I/- Mousana i Mlousand : t1hougands i Thoui4nd: T Tons 4 S Tons I I Tenn I Study Area 4 Raw Waste - - - - : 2,198.1 966.5 -56.0 616.1 -72.0 413.7 -81.2 Total Solids- - -. 265.1 118.2 -55.4 75.5 -71.5 50.8 -80.8 Volatile Solids -. A 35. 3 55.6 -58.9 34.8 -74.3 23.5 -82.6 BOD5 - - - - - - -- 33.5 12.3 -63.3 7.5 -77.6 4.9 -85.4 COD - - - - - - -* 149.4 60.3 -59.6 37.7 -74.8 25.4 -83.0 TKN - - - - - - -- 11.1 4.7 -57.7 3.0 -73.0 2.0 -82.0 P- - - - - - - - 2.2 0.7 -68.2 0.4 -81.8 0.3 -86.4 K- - - - - - - -- 5.3 2.0 -62.3 1.2 -77.4 0.8 -84.9 Study Area 5 Raw Waste 864.5 423.1 -51.1 416.6 -51.8 420.3 -51.4 Total Solids- 102.1 50.6 -50.4 49.6 -51.4 50.1 -50.9 Volatile Solids 51.2 21.2 -58.6 20.5 -60.0 21.1 -58.8 6.7 -55.6 6.3 -58.3 6.1 -59.6 BOD5 - - - - - - 15.1 COD - - - - - - -- 58.3 24.5 -58.0 23.6 -59.5 23.9 -59.0 TKN - - - - - - -* 4.6 2.2 -52.2 2.2 -52.2 2.2 -52.2 P- - - - - - - -- 1.0 0.4 -60.0 0.4 -60.0 0.4 -60.0 K- - - - - - - - 2.2 0.9 -59.1 0.9 -59.1 0.9 -59.1 VIRGINIA Raw Waste 13,856.8 7,686.9 -44.5 7,109.7 -48.7 7,209.9 -48.0 Total Solids- 1,643.7 923.6 -43.8 860.4 -47.7 881.7 -46.4 Volatile Solids 905.3 398.7 -56.0 335.3 -63.0 311.7 -65.6 BOD5 - - - - - - -- 249.1 117.9 -52.7 163.2 -58.6 97.2 -61.0 COD - - - - - - -- 1,018.4 456.1 -55.2 386.8 -62.0 360.6 -64.6 TKN - - - - - -- -*@' 73.1 40.2 -45.0 37.3 -49.0 37.7 -48.4 P- - - - - - - -- 16.4 7.6 -53.7 6.7 -59.1 6.4 -61.0 K- - - - - - - - * 37.6 16.7 -55.6 14.4 -61.7 13.4 -64.4 Study Area 1 Raw Waste 264.3 156.2 -40.9 173.2 -34.5 195.3 Total Solids - - - 31.9 19.1 -40.1 21.4 -32.9 24.5 -23.2 Volatile Solids _. 18.0 8.0 -55.6 8.0 -55.6 8.1 -55.0 BOD5 - - - - - - -* 5.5 3.0 -45.5 3.1 -43.6 3.2 -41.8 COD - - - - - - -:' 20.8 9.7 -53.4 9.8 -52.9 9.9 -52.4 TKN - - - - - - -- 1.5 0.9 -40.0 1.0 -33.3 1.1 -26.7 0.2 -50.0 0.2 -50.0 0.2 -50.0 P- - - - - - - -- 0.4 0.4 -50.0 0.4 @50.0 0.4 -50.0 K- - - - - - - -- 0.8 Study Area 2 Raw Waste 4,369.0 2,011.9 -54.0 1,530.9 -65.0 11,263.1 -71.1 Total Solids- 526.3 247.9 -52.9 189.9 -63.9 157.3 -70.1 Volatile Solids 272.1 84.8 -68.8 51.2 -81.2 35.8 -86.8 BOD5 - - - - - - - 69.1 19.8 -71.3 12.4 -82.1 8.9 -87.1 COD - - - - - - -- 301.7 92.8 -69.2 56.3 -81.3 39.5 -86.9 T" - - - - - - - 22.3 9.6 -57.0 7.3 -67.3 6,0 -73.1 P- - - - - - - -- 4.5 1.2 -73.3 0.8 -82.2 .0.6 -86.7 K- - - - - - - - 10.9 3.2 -70.6 2.0 -81.7 1.4 -87.2 Study Area 3 Raw Waste - 1,230.7 643.8 -47.7 696.5 -43.4 -35.1 Total Solids- 2 148.0 79.0 -46.6 86.3 -41.7 98.8 -33.2 Volatile Solids 79.2 28.1 -64.5 26.1 -67.0 26.0 -67.2 BOD5 - - - - - - -* 20.3 7.0 -65.5 6.5 -68.0 6.7 -67.0 COD - - - - - - - 87.9 31.1 -64.6 29.0 -67.0 28.8 -67.2 TKN - - - - - - 2 6.3 3.1 -50.8 3.4 -46.0 3.8 -39.7 P -- 1.3 0.4 -69.2 0.4 -69.2 0.4 -69.2 K- - - - - - - -6 3.2 1.1 -65.6 1.0 -68.8 1.0 -68.8 Attachment D. Table 6-D-4--P-nnual Liyestock & Poultry, Wastes and Pollutants-p Chesapeake Bay Study, 1970. 1980, 2000, and 2020. l/ (Cont.) 1970 1980 2000 2020 BU-b 'Pollutant P*'**t perftat I Pollutant I percent state and area Pollutant Oollutant, I amse-Y4 I Wi_u__*mdI_ 'rhousead 8 1 Mmmands I 7hounandt T=5 I Tons I a Tons I I Tons Study Area 4 Rdw Waste - - - - 2,658.8 1,293.7 -51.3 942.0 -64.6 773.3 -70.9 Total Solids - - 314.8 156.0 -50.4 112.5 -64.3 92.2 -10.7 Volatile Solids@: 178.9 79.9 -55.3 65.5 -63.4 59.6 -66.7 BOD5 - - - - - - : 48.4 23.0 -52.5 19.3 -60.1 17.6 -63.6 COD - - - - - - : 200.4 91.0 -54.6 75.0 -62,6 68.2 -66.0 TKN - - - - - - : 14.0 7.0 -50.0 5.2 -62.9 4.4 -68.6 P- - - - - - - - : 3.2 1.5 -53.1 1.2 -62.5 1.1 -65.6 K7 - - - - - - - : 7.3 3.2 -56.2 2.7 -6.3.0 2.4 -67.1 Study Area 5 Raw Waste - - - - 2,092.0 1,185.5 -43.3 1,125.5 -46.2 1,071.6 -48.8 Total Solids - -: 246.0 138.4 -43.7 129.4 -47.4 122.6 -50.2 Volatile Solids-: 139.2 63.2 -54.6 57.8 -58.5 53.8 -61.4 BM5 - - - - - - 39.4 19.9 -49.5 18.7 -52.5 17.6 -55.3 COD - - - - - - - 157.4 72.9 -53.7 66.8 -57.6 62.2 -60.5 TKN - - - - - - - 11.2 6.3 -43.8 5.9 -47.3 -5.6 -50.0 P- - - - - - - - 2.6 1.3 -50.0 1.2 -53.8 1.1 -57.7 K- - - - - - - - 5.9 2.8 -52.5 2.6 -55.9 2.5 -57.6 Study Area 6 Raw Waste - - - - 143.3 165.0 15.1 220.7 54.0 298.1 108.0 Total Solids 17.6 21.0 19.3 28.3 60.8 38.2 117.0 Volatile Solids-: 8.5 10.1 18.8 12.3 44.7 15.5 82.4 DM5 - - - - - - : @2.2 2.2 0.0 2.7 22.7 3.3 50.0 CO D - - - - - - : 9.5 11.1. 16.8 13.4 41.1 16.9 77.9. TKN - --- - - - : 0.7 0.8 14.3 1.1 57.1 1.5 114.3 P- - - - - - - -: 0.1 0.1 0.0 0.2 100.0 0.2 100.0 X- - - - - - - - 0.3 0.3 0.0 0.4 33.3 0.5 66.7 Study Area 7 Raw Waste - - - - 737.9 481.9 -34.7 406.2 @45.0 359.8 Total Solids - -: 84.9 58.0 -31.7 49.7 -41.5 45.3 -46.6 Volatile Solids-: 51.7 32.1 -37.9 27.3 -47.2 25.2 -51.3 BOBS - - - - - - t 15.1 10.2 -32.5 9.5 -37.1 9.2 -39.1 COD - - - - - - - : 58.8 37.4 -36.4 32.5 -44.7 30.4 -48.3 TKN - - - - - - : 4.0 2.8 -30.0 2.5 -37.5 2.3 -42.5 P- - - - - - - - t 1.0 0.7 -30.0 0.6 -40.0 0.6 -46.0 K- - - - - - - - 1 2.2 1.4 -36.4 1.2 -45.5 1.1 -50.0 Study Area 8 Raw Waste - - - - :21360.6 1,748.7 -25.9 2,014.7 -14.7 2,450.4 Total'Solids - -: 274.3 204.1 -25.6 243.0 -11.4 302.8 10.4 Volatile Solids-: 157.7 92.4 -41.4 87.1 -44.8 87.7 -44.4 BW5 - - - - - - : 49.0 32.8 -33.1 31.1 -36.5 30.8 -37.1 COD - - - - - - : 181.8 110.0 -39.5 104.0 -42.8 104.6 -42.5 TKN - - - - - - : 13.1 9.7 -26.0 11.0 -16.0 13.0 -0.8 p- - - - - - - - : 3.3 - 2.2 -33.3 2.1 -36.4 i.1 -36.4 x- - - - - - - - : 7.0 4.3 -38.6 4.1 -41.4 4.6 -42.9 I/ Percent change fro* 1970 polluntants. CORPS OF ENGINEERS U. S. ARMY % '+ M to ..at BEL 0 41 m nrti 10 % or D E L A \W A R E B A Y LLE #0 OFTON onsboro zg- % V Ml J D M % BALTIMORE SERVICE AREA IN WATER SERVICE AREAS SUBREGION BOUNDARY -V BALTIORIPARTMENT OF THE ARMY MORE DISTIUCT, CORPS OF ErRUNEERS '-,@!AFORV A@D CHESAPEAKE DAY STUDY rY 'V lie FUTURE CONDITIONS REPORT SUBREGIONS I and 2 WATER SUPPLY X UPPER BAY PLATE 5-1 CORPS OF INEERS U. S. ARMY 72@ 0 TA 0 /45 / I -A I 4_1 0- 14, L A- D E L A A R. E B A Y Q A , R FAIRFAX CO. WATER AUTHORITY WASHINGTON SUBURBAN SANITARY COMMISSION "J D.C. -ARLINGTON -FALLS CHURCH WATER SERVICE AREAS SUBREG16N BOUNDARY DEPARTMENT OF THE ARMY @TIMORIE DISTRICT. CORPS OF ENGINEERS CHESAPEAKE BAY STUDY J FUTURE CONDITIONS REPORTS WATER SUPPLY SUBREGION 5 L-REL UPPER BAY PLATE 5-2 NJ CORPS OF ENGINEERS U. S. ARMY 4_1 k@ kill," op 4- 0 Ac- 10 0 Z, g1l L L D E L A \W A R, E B A Y ,kw-z y FAIRFAX CO. WATER AUTHORITY WASHINGTON SUBURBAN SANITARY COMMISSION & ILTI D.C. -ARLINGTON -FALLSCHURCH WATER SERVICE AREAS _NT rl SUBREGION BOUNDARY IDEPARMENT OF THE ARMY IMLTIMORE DISTRICT, CORPS 0 ENGlNMM CHESAPEAKE BA STUDY A FUTURE CONDITIONIS REPORTS 0. WATER SUPPLY a SUBREGION 5 LAUREL I v -nn UPPER BAY PLATE 5-2 CORPS OF EN2iNEFRS U. S. ARMY j Wki till -7 E'a 4i ",Jk , @ ; /V "o, ON AA i cg Orldg 4z Re -b Beach 4-, e_ , - 9 rgetown TOW- A RD "W160 EGIO Q 4, L 1 1,44 -@t) #fnc`6VVmdeiIck\ -@q ELM suagai V @@l (7 N6 y 'CE In OR CKSBURG,- g 2 4- TON s, SSANNE 0', 0 2' o M A C R r SUM IMOKECITY Lockout (Souther 0 Green TA L C su rtl C`B A, ky w A., �1- WATER SERVICE AREAS SUBREGION BOUNDARY MLYIDEPARTMENT OF THE ARMY COR MORE OISrRICT. PS OF ENGINEERS @ I SALTIMORM, AY > BAY 'CHESAPEAKE BAY STUDY FUT RE CONDITIONS REPORT U > SUPPLY WATER -RICHA011 SUBREGIONS. 2 (Southern Portion), 4, 6, 7, and 9 (Northam Portlonl MIDDLE BAY PLATE 5.3 CORPS OF ENGINEERS U. S. ARMY e Jj r, Ste Chumh 3 iAS NO no owt, ANICSVI > 4 to sulift cl C-k on rles City SUBR C, elf I APPOM A WILL71 C4wli. 19 R.- EIG a J@h *60 A.F.B. ITH D 1, vt'" j Lake Bu- AW I$ >1 SERVICE CO ERAGE WATER SERVICE AREAS. SUBREGION BOUNDARY t-ulv DEPAFrrMENT OF THE ARMY BAL.MMORE DISTRICT. CORPS OF ENGINSSRS 110 N CHESAPEAKE SAY STUDY FUTURECONDITIONS REPORT WATER SUPPLY 4, 'SUBREGIONS i, 8, 9 (SoMern Portionj 10, 11, and 12 -3iz PAY LOWER PLATE 54 3 6668 00002 3020