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           Draft Model Comprehensive Plan Ground Water Amendment 9/30/92

                                                                            FY'91               Task 5 2

                                                                                Final Product
                                                                               VA Coastaf Xesoumes Mgt. Program
                                            DRAFT 9/30/92                             12j31 &2










                       MODEL COMPREHENSIVE PLAN GROUND WATER AMENDMENT








                                            Prepared by:
                                     Eastern Shore of Virginia
                                  Ground Water Study Committee













                               Technical Assistance Provided by:

                     Accomack-Northampton Planning District commission
                                             P.O. Box 417
                                         Accomac, VA 23301



           TD                        This document was funded in part by the
           403                        Virginia CounciL on the Environnment's
            M62                        CoastaL Resources Management Program
           1-992                       through Grant #NA170ZO359-01 of the
                               NationaL Oceanic and Atmospheric Administration under the
                                  CoastaL Zone Management Act Of 1972 as amended.








         Draft Model Comprehensive Plan Ground Water Amendment 9/30/92



                                      GROUND WATER



         Background
         Ground water is the only source of supply f or domestic, industrial,
         and agricultural water use on the Eastern Shore of Virginia.            A
         total popul  ation of approximately 47, 000 people use this ground
         water. Because of the limited supply of ground water, in 1976 the
         Virginia State Water Control Board designated the Eastern Shore of
         Virginia a "Ground Water Management Area". The Eastern Shore was
         the second area in Virginia to be declared a ground water
         management area. This declaration was based on the findings that:

               -   Ground water level declines have been observed in two
               sections of Accomack County;
               - -Interference,between wells has been observed in the same
               two sections of Accomack County;
               - Some evidence of localized ground water contamination has
               been observed in the water table aquifer of Accomack County
               but not in the confined aquifers;
               - Even though the ground water supplies in Accomack County
               are not overdrawn and are not expected to be in the near
               future, it should be recognized      that they may overdraw in
               some areas in the future if water withdrawals are not
               distributed throughout the region.           Further, saltwater
               intrusion has not been observed to date but may occur in the
               future if heavy ground water withdrawals are concentrated in
               any one area.

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

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


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         Draft Model Comprehensive Plan Ground water Amendment 9/30/92

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

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

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

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

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

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

         Based upon the ground water modelling studies conducted,
         approximately 11 million gallons per day is recharged to the
         Yorktown-Eastover aquifer. However, it should be noted that this

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         Draft Model Comprehensive Plan Ground Water Amendment 9/30/92

         recharge value is based on average conditions across the entire
         Eastern Shore. Depending upon specific site conditions recharge
         to the Yorktown-Eastover aquifer may vary by a factor of two.

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

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


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


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

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


         Adequate Water Supply for Future Demands

         Although it is estimated that there is only 11 million gallons per
         day available from the Yorktown-Eastover aquifer, current permits
         issued by the Virginia State Water Control Board would allow

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         Draft Model comprehensive Plan Ground Water Amendment 9/30/92

         withdrawals of up 15.6 million gallon per day from this aquifer.
         If this were to occur, problems of well interferences and salt
         water intrusion, already observed near the largest industrial water
         users, will be greatly enhanced.


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

         Recommendations for Water Ouality Protection:
              - Pursue water conservation measures with major industrial
              users.
              - Create an overlay protection zoning district to protect the
              spine recharge area to the Yorktown-Eastover aquifer;
              - Restrict the siting of new mass drainfields in the spine
              recharge area;
              - Review and revise county zoning and subdivision regulations;
              -   Require   the   registration   of currently     unregulated
              underground storage tanks;
              - Incorporate ground water protection requirements into site
              plan review;
                Develop a private well ordinance to control the siting and
              construction of new wells;
              - Support the implementation of agricultural nutrient
              management plans;
                Implement the provisions of the Chesapeake Bay Program.

         Recommendations for Water Ouantity Management
                Revise State Ground Water Act and Regulations to allow for
              re-evaluation of existing permits;
              - Develop an Eastern Shore Water Management District to manage
              water withdrawals;
                Control the siting and development of new water supply wells
              to prevent well interference and reduce the threat of salt
              water intrusion;
                 Continue the Accurate reporting of agricultural water
              withdrawals, by well location and depth.
              - Continue the consideration of mandatory permitting of
              agricultural withdrawals after review of reporting data.
              - Protect open space and undeveloped land in the spine
              recharge area.

         General Recommendations
                Implement a land use/water quality data base;
                Develop a public education program on ground water.

         Continued Research and Investigation
              - Investigate the nature of recharge  to the Yorktown-Eastover
              aquifer;

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          Draft Model Comprehensive Plan Ground Water Amendment 9/30/92

               - Research dilute salt water issues;
               - Conduct additional hydrogeologic studies to better define
               the geology;
               - Evaluate pesticide use on the Eastern Shore;
               - Revise the nitrogen model used in the study over time.


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

          Goals and Objectives for Ground Water Quality Protection

          Goal:           Achieve industrial water conservation.

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


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

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


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

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


          Goal:           Minimize ground water impacts from agricultural
                          activities.                                    I
          Objective:      Provide assistance in developing agricultural
                          nutrient management plans and implement the
                          provisions of the Chesapeake Bay Preservation Act.

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          Draft Model Comprehensive Plan Ground Water Amendment 9/30/92
                                                                          1
          Goals:          Educate the public about proper ground water use and
                          educdtion.

          Objective:      Develop a public education program on ground water.


          Goals and Objectives for Ground Water ouantity Management

          Goal:           Re-evaluate existing ground water permits.

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


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

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

          Goal:           Accurately document agricultural ground water
                          withdrawals.

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

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

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


          Goal:           Improve knowledge of Eastern Shore ground water
                          system.

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


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

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          Draft Model Comprehensive Plan Ground Water Amendment 9/30/92

          Actions for Ground Water Ouality Protection

          Action:   Develop an industrial water conservation program.


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


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


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

          Action:   Develop a public education program on ground water.


          Actions for Ground Water Quantity Management                  I

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

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

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

          Action:   Develop a land use/water quality data base by accurately
                    documenting and recording ground water quantity and
          Action:   quality.
                    Investigate the nature of recharge to the Yorktown-
                    Eastover aquifer, research dilute salt water issues,
                    conduct additional hydogeologic studies to better define
                    the geology, evaluate pesticide use on the Eastern Shore,
                    revise the nitrogen model used in the study over time.



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