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


                                                                           Task 63 FY 90
                                                                           Final Work Product
                       Stafford County Ground Watel, ocqq rqo@
                        Resource Protection Program



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                                       Prepared for:

                                   County of Ste@fford
                                       Staff, ord, VA



                                             By:

                               GKY and Associates, Inc.
                                  Springfield, Virginia


                                    FINAL REPORT


                                   December 31, 1991

         TD
         403
         .S73    lound Water Resource Protection ProVam was funded, in part, by the Vi@giili tz
         1991    f on the Environment's Coastal Resources Management Prograin through
                 NrA90A.4-H-CZ796 of the National Oceanic andAtinospheric Administration
                 fie Coastal Zone Man'agement Act of 1972, as amended.










                                                                                    Received by:
                                                                                Council on the Environment

                                  STAFFORD COUNTY GROUND WATER RESOURCE
                                            PROTECTION PROGRAM                     JAN 29 1992










                                              Prepared for:

                                           County of Stafford
                                           1300 Courthouse Road
                                               P.O. Box 339
                                        Stafford, VA 22554-0339






                                              Prepared by:

                                        GKY and Associates, Inc.
                                          5411-E Backlick Road
                                         Springfield, VA 22151
                                              (703)642-5080






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







                                              December 31, 1991



                                       Property of CSC Library









                                             TABLE OF CONTENTS
                                                                                           Page


             COVER PAGE  ...............................................................     i

             TABLE OF CONTENTS  ........................................................   ii

             LISTS OF TABLES AND FIGURES   ..............................................  iv

             SECTION 1. INTRODUCTION   .................................................     1

                 PURPOSE  ..............................................................     I
                 BACKGROUND  ...........................................................     1

             SECTION 2. GROUND WATER   .................................................     3

                 COUNTY GROUND WATER RESOURCES  .................   ......................   3
                 GROUND WATER COMTAIMINATION   ..........................................    3

             SECTION 3. METHODOLOGY  ...................................................     5

                 DRASTIC OVERVIEW  .....................................................     5
                    Depth to Water  ....................................................     7
                    Net Recharge  .......................................................    7
                    Aquifer Media  .....................................................     7
                    Soil Media  ........................................................     7
                    Topography  ........................................................     8
                    Impact of the Vadose Zone  .........................................     8
                    Hydraulic Conductivity  ............................................     8
                    The DRASTIC Parameters  ............................................     9

                 DRASTIC RANKING SYSTEM  ...............................................   10
                 DRASTIC MODEL  ........................................................   17

            SECTION 4. DATA COLLECTION AND RATING DEVELOPMENT     .......................  18

                 DEPTH TO WATER  .......................................................   18
                 NET RECHARGE  .........................................................   18
                 AQUIFER MEDIA  ........................................................   18
                 SOIL MEDIA  ...........................................................   19
                 TOPOGRAPHY  ...........................................................   19
                 IMPACT OF THE VADOSE ZONE MEDIA  ......................................   19
                 HYDRAULIC CONDUCTIVITY  ...............................................   20

            SECTION 5. RESULTS   ......................................................    21

                 STUDY SUMMARY  ........................................................   21
                 SPREADSHEETS  .........................................................   21
                 SURFER  ...............................................................   21
                 MAPPING DRASTIC RESULTS  ..............................................   22



                                                    ii









                                                TABLE OF CONTENTS
                                                    (continued)
                                                                                                Page


              SECTION 6. GROUND WATER RESOURCE PROTECTION OVERLAY AREAS         ...............  24

                  GUIDELINES FOR LOW GROUND WATER POLLUTION POTENTIAL AREAS        ............  24
                  GUIDELINES FOR MODERATE GROUND WATER POLLUTION POTENTIAL AREAS        .......  25
                  GUIDELINES FOR HIGH GROUND WATER POLLUTION POTENTIAL AREAS        ...........  26

              GLOSSARY  .................................................................        27

              REFERENCES  ...............................................................        28

              APPENDIX A: DRASTIC DATA BASE      ...........................................     30

              APPENDIX B:   GEOGRAPHIC DISTRIBUTION OF DRASTIC PARAMETER RATINGS       ........  43















                                                    LIST OF TABLES


               No.                                                                                   Page
               1.  Assigned Weights for DRASTIC Features       .......                       ......   11
               2.  Ranges  and  Ratings   for  Depth to Water  ................................       12
               3.  Ranges  and  Ratings   for  Net Recharge... *'****  .........................      14
               4.  Ranges  and  Ratings   for  Aquifer Media  *'*****  ...........................    14
               5.  Ranges. and  Ratings   for  Soil Media  .....................................      15
               6.  Ranges  and  Ratings   for  Topography ...................   :**'****''*  ... -* 15
               7.  Ranges  and  Ratings   for  Impact of the Vadose Zone Media      ................  16
               8.  Ranges  and  Ratings   for  Hydraulic Conductivity    .........................    16



                                                   LIST OF FIGURES

               No.                                                                                   Page


               1.  DRASTIC Parameter Schematic      ...........................................         6
               2.  DRASTIC Overlay Scheme     .............. * ..................................     13
               3.  Depth to Water (D) Rating      .............................................       44
               4.  Net Recharge (R) Rating     ...............................................        45
               5.  Aquifer Media (A) Rating     ...............................................       46
               6.  Soil Media (S) Rating     .................................................        47
               7.  Topography (T) Rating    ........ : ........................................       48
               8.  Impact of Vadose Zone (1) Rating       ......................................      49
               9.  Hydraulic Conductivity (C) Rating       .....................................      50
               10. Composite DRASTIC Index Rating      ........................................       51














                                                            iv
















                                                 SECTION I

                                               INTRODUCTION



             PURPOSE

                  The purpose for developing a Ground Water Resource Protection Program as a
             part of the Shoreline Area Management Plan component of the Stafford County
             Comprehensive Plan is to assist the Board of Supervisors and Planning Commission
             in making land use decisions.    The data, maps, and recommendations from this
             document will be used in determining a potential development's impact on the
             County's ground water resources and to provide recommendations which can mitigate
             any potential degradation identified. Development must proceed in a manner that
             is not detrimental to the County's ground water resources.

                  In July 1988, Section 15.1-446.1 of the Code of Virginia (1950), was amended
             to add ground water protection as an item that. local governments should consider
             when evaluating land use proposals. A growing awareness of the vulnerability of
             ground water to pollution, especially from development, has led the County to
             seek a coordinated effort to protect ground water resources.         Residential,
             commercial, and industrial uses rely heavily on ground water to supply a portion
             of their needs. Indeed, in many areas of the County, ground water is the only
             feasible source of water.

                 This Ground Water Resource Protection Program was funded, in part, by the
             Virginia Council on the Environment's Coastal Resources Management Program
             through grant #NA90AA-H-CZ796 of the National Oceanic and Atmospheric
             Administration under the Coastal Zone Management Act of 1972 as amended.

             BACKGROUND

                 Stafford County is located in the northeast region of Virginia approximately
             fifty-six (56) miles north of Richmond and forth (40) miles south of Washington,
             D.C. The County is bisected by 1-95, which is also the' approximate dividing line
             between the two physiographic regions (Coastal Plain and Piedmont) which define
             the surface features of the County.

                 Currently, the County draws its public water supply from two impoundments,
             Abel Lake and Smith Lake, that rely, in large part, upon ground water recharge.
             In addition, approximately one-half of Stafford County residents rely on private
             wells recharged by ground water supplies.     These recharge areas need to be
             identified and strategies developed to ensure a safe and adequate water supply
             for the County.








                   Stafford County is a predominantly rural locality experiencing the pressures
             of suburban development from the Fredericksburg and Northern Virginia.areas. The
             1990 decennial census documented a fifty-one (51) percent growth rate in the
             County from 1980-1990 from 40,470 to 61,236. This has resulted in a greater need
             to ensure that the development which occurs is planned in a way that protects the
             County's ground water resources. This Ground Water Resource Protection Program
             is the first step towards ensuring that as development occurs, specific
             strategies are implemented to protect the County's ground water resources.









































                                                     2
















                                                  SECTION 2


                                                GROUND WATER



             COUNTY GROUND WATER RESOURCES

                  Stafford County is in the position of having ground water reserves; however,
             this supply is a dynamic resource intimately connected with and affected by
             general land use activities. Ground water is generally recharged through water
             percolating through the soil or through direct resupply by surface water in areas
             where ground water aquifers outcrop at the surface. The quantity and quality of
             the water that reaches the ground water aquifers depends on the amount and type
             of topography, vegetation, soils, land use, and underlying bedrock.

                  That ground water is naturally cleansed of pollution as it moves through the
             soil is a common misconception.    Although soil has the capacity to filter and
             absorb pollutants, many pass through the soil layer.     Increasing the amount of
             pollutants entering the soil will lessen the soil's ability and capacity to
             filter pollutants.   In addition, stream, marsh, and wetland environments and the
             sensitive wildlife habitats they support are preserved by ground water during dry
             periods.

                  In Stafford County, a large surface recharge area for the Potomac aquifer
             is located along, and generally parallel to, 1-95. This recharge area is located
             at the fall line (the dividing line between the Coastal Plain and Piedmont
             Physiographic Regions).   This aquifer provides an important water resource to
             residents in the eastern part of the County and for residents in King George
             County.

                  Other aquifers that are within the County include:      the Piedmont in the
             western part of the County, the Chickahominy/Piney Point and the Aquia in the
             southeastern section of the County, and the Potomac in the central and northern
             portions of the County.

                  Residential, commercial, and industrial land uses, if improperly developed,
             can have an adverse impact on the County's ground water resources.    This Ground
             Water Resource Protection Program provides recommendations that can assist'in
             protecting ground water     resources while still     providing for growth and
             development.

             GROUND WATER CONTAMINATION

                 Ground water pollution  is caused by a variety of substances originating from
             many different activities.  In general, pollutants enter ground water through the
             following pathways:   1) improper application of fertilizers, pesticides, and
             other water soluble products on the land surface; 2) runoff frdm development

                                                     3








              sites; 3) leakage from landfills, underground storage tanks, and improperly
              operating septic systems; 4) improper storage and disposal of toxic substances;
              5) the burial in the ground of inorganic (man-made) substances or organic
              substances that nave been chemically treated; 6) the injection of materials into
              the ground; and 7) the leaching of pollutants from the soil or bedrock.
                   After release on the land surface, the pollutant may infiltrate downward
              through the soil. If the volume of pollutant is not great, the pollutant may be
              attenuated.   If the pollutant is not completely attenuated, it may later be
              flushed toward the water table by infiltrating precipitation or additional
              amounts of pollutant.    The majority of pollutants will generally travel in the
              direction of ground water flow at a velocity slightly less than that of the
              ground water.

                   The attenuation process includes mechanisms which reduce the velocity of the
              pollutant through processes such as dilution, dispersion, mechanical filtration,
              volatilization,   biological   assimilation and decomposition,       precipitation,
              sorption, ion exchange, oxidation-reduction, and buffering and neutralization.
              The degree of attenuation which can occur is a function of 1) the time that the
              pollutant is in contact with the material through which it passes, 2) the grain
              size and physical and chemical characteristics of the material through which it
              passes, and 3) the distance which the pollutant has traveled.       In general, for
              any given material, the longer the time the pollutant takes to move through the
              material and the greater the distance of the movement, the greater the effects
              of attenuation.    In a similar manner, the greater the surface area of the
              material through which the pollutant passes, the greater the potential for
              sorption of the pollutant and, hence, for attenuation.            The greater the
              reactivity of the material through which the pollutant passes, the greater the
              potential for attenuation.     Any combination of these processes may be active
              depending on the hydrogeologic conditions and the characteristics of the
              pollutant.  It is therefore necessary to have a general idea of these processes
              and whether they are active.
                   The effectiveness of dilution and attenuation processes is largely
              determined by 1) the rate and loading of the applied pollutant, 2) the
              characteristics   of   the   pollutant,   and  3)   the   physical   and    chemical
              characteristics of the area.   Ultimately, it is these factors which control the
              ground water pollution potential of any area.      The rate and loading factor is
              generally of site-specific character.     However, it is the physical properties
              characterized by the hydrogeologic characteristics of the area that determine the
              extent to which the attenuation'mechanisms may have the potential to be active.

                  Because it is neither practical nor feasible to obtain quantitative
              evaluations of these intrinsic mechanisms from a regional perspective, it is
              necessary to look at the broader physical parameters which incorporate the many
              processes.  This is accomplished under the DRASTIC methodology.        Each of the
              DRASTIC parameters includes various mechanisms which will help to evaluate the
              vulnerability of ground water to pollution.        When this is coupled with an
              understanding of the hydrogeology of the area, the result will be a clearer image
              of the potential for pollutant travel and attenuation.



                                                       4















                                                  SECTION 3

                                                 NETHODOLOGY


             DRASTIC OVERVIEW

                   The DRASTIC (Aller, et al.,   1987) model was used to evaluate ground water
             pollution potential in Si-afTo-rd   County.   This section discusses the DRASTIC
             methodology and how it was applied in this study.

                   DRASTIC is a methodology for evaluating the relative ground water pollution
             potential of an area through the application of an environmental component
             rating system. This rating system allows for the assessment of the vulnerability
             of an area to ground water contamination based on various hydrogeologic
             parameters. DRASTIC was developed by the National Water Well Association under
             the sponsorship of the Environmental Protection Agency. The following discussion
             is largely taken from the DRASTIC documentation (Aller, et al., 1987).

                   DRASTIC  is an acronym that represents the most          important physical
             characteri sti cs, ei ther al one, or i n combi nati on, for determi ni ng suscepti bi 1 i ty
             to ground water contamination.       The DRASTIC factors represent measurable
             parameters for which data is generally available from a variety of sources
             without detailed reconnaissance.

                   D    -    Depth to Water;
                   R    -    (Net) flecharge;
                   A    -    Aquifer Media;
                   S    -    Soil Media;
                   T    -    lopography (Slope);
                   I    -    Impact of the Vadose Zone Media; and
                   C    -    Conductivity (Hydraulic) of the Aquifer.


                   These factors, as shown in Figure 1, form the acronym, DRASTIC, for ease of
             reference. While this list is not all inclusive, these factors, in combination,
             were determined to include the basic requirements needed to assess general
             pollution potential.







                                                     5































                                                                                                                          Pre cipltat4om

                                                                                                     Topography
                                                                                                          (T)






                                                                                   to
                                                                            Water (0)

                                                                                                            0



                                                                                                   V Ol/
                                                                                                IV

                                                                                         INEEM11\',
                                                                                         Hydraulic
                                                                                        Coniuct4vity
                                                                                             (C)








                                                                             Figure 1
                                                 DRASTTC Parameter Schematic



                                                                                           6









             Depth to Water

                   Depth to water is important primarily because it determines the depth of
             material through which a pollutant must travel before reaching the aquifer, and
             it may help to determine the contact time with the surrounding media.              In
             general, there is a greater chance for attenuation to occur as the depth to water
             increases because deeper water levels imply longer travel times. The ranges in
             depth to water as defined in the DRASTIC system have been determined based on
             what are considered to be depths where the potential for ground water pollution
             significantly changes.

             Net Recharge

                  The primary source of ground water typically is precipitation which
             infiltrates through the surface of the ground and percolates to the aquifer. Net
             recharge represents the amount of water per unit area of land which penetrates
             the ground surface and reaches the water table.       This recharge water is thus
             available to transport a pollutant vertically to and horizontally within the
             aquifer.    In addition, the quantity of water available for dispersion and
             dilution of the pollutant in the vadose zone and in the saturated zone is
             controlled by this parameter. Recharge-water, therefore, is a principal vehicle
             for leaching and transporting solid or liquid pollutants to the water table. The
             greater the recharge, the greater the potential for ground water pollution. This
             general statement is true until the amount of recharge is great enough to cause
             dilution of the pollutant, at which point the ground water pollution potential
             ceases to increase and may actually decrease.            This phenomena has been
             acknowledged but the ranges and associated ratings do not reflect the dilution
             factor.

             Aguifer Media

                  Aquifer media refers to the consolidated or unconsolidated material which
             serves as an aquifer (such as sand and gravel or limestone).         An aquifer is
             defined as a subsurface rock unit which will yield sufficient quantities of water
             for use.  Water is contained in aquifers within the pore spaces of granular and
             clastic rock and in the fractures and solution openings of non-clastic and non-
             granular rock. The media that water must flow through is an important control
             (along with hydraulic conductivity and gradient) in determining the time
             available for attenuation processes such as sorption, reactivity, and dispersion
             to occur.   The aquifer medium also influences the amount of effective surface
             area of materials with which the pollutant may come in contact within the
             aquifer.   In general, the larger the grain size and the more fractures or
             openings within the aquifer, the higher the permeability and the lower the
             attenuation capacity of the aquifer media.

             Soil Media

                  Soil media refers to that uppermost portion of the vadose zone characterized
             by significant biological activity.      Soil is commonly considered the upper
             weathered zone of the earth which averages a depth of six feet or less from the
             ground surface. Soil has a significant impact on the amount of recharge which
             can infiltrate into the ground and, hence, on the ability of a pollutant to move

                                                      7








              vertically into the vadose zone.   The presence of fine-textured materials sucn
              as silts and clays can decrease relative soil permeabilities and restrict
              pollutant migration.     Moreover, where the soil zone is fairly thick, the
              attenuation processes.of filtration, biodegradation, sorption, and volatilization
              may be quite significant.    Thus, for certain land surface practices, such as
              agricultural applications of pesticides, soil may have the primary influence on
              pollution potential.   In general, the pollution potential of a soil is largely
              affected by the type of clay present, the shrink/swell potential of that clay,
              and the grai n si ze of the soi 1 . In general , the 1 ess the cl ay shri nks and swel 1 s
              and the smaller the grain size, the less the pollution potential.   The quantity
              of organic material present in the soil may also be an important factor
              particularly in the attenuation of pesticides.      Organic matter is typically
              contained in the surface layer of the soil and composed of undecayed plant and
              animal tissue, charcoal, and" various humic compounds. The organic content of the
              soil generally decreases with depth from the surface.

              Topography

                  As used here, "topography" refers to the slope and slope variability of the
              land surface. Topography influences the likelihood that a pollutant will run off
              or remain on the surface in one area long enough to infiltrate.     Slopes which
              provide a greater opportunity for pollutants to infiltrate will be associated
              with a higher ground water pollution potential.      Topography influences soil
              development and therefore has an effect on pollutant attenuation. Topography is
              also significant because gradient and direction of flow often can be inferred for
              water table conditions from the general slope of the land.    Typically, steeper
              slopes signify higher ground water velocity.

              Impact of the Vadose Zone

                  The vadose zone is defined as that zone above the water table which is
              unsaturated or discontinuously saturated.      The type of vadose zone media
              determines the attenuation characteristics of the material below the typical soil
              horizon and above the water table.  The media also controls the path length and
              routing, thus affecting the time available for attenuation and the quantity of
              material encountered.

              Hydraulic Conductivit

                  Hydraulic conductivity refers to the ability of the aquifer materials to
              transmit water, which in turn, controls the rate at which ground water will flow
              under a given hydraulic gradient. The rate at which the ground water flows also
              controls the rate at which a pollutant moves away from the point at which it
              enters the aquifer.   Hydraulic conductivity is controlled by the amount and
              interconnection of void spaces within the aquifer which may occur as a
              consequence of intergranular porosity, fracturing, and bedding planes.        For
              purposes of this model, hydraulic conductivity is divided into ranges where high
              hydraulic conductivities are associated with higher pollution potential.





                                                     8









              The DRASTIC Parameters

                    From the discussions on the DRASTIC parameter, it is apparent that there is
              overlap between the various parameters.       The depth to the water, for example,
              affects the quantity of material that will be encountered by a pollutant moving
              downward toward an aquifer. The thicker the vadose zone in a given setting, the
              greater the effect may be upon the degradation, retardation, or attenuation of
              the pollutant.

                   However, in considering the impact of the vadose zone, degradation,
              retardation, and other significant attenuation processes are all varied according
              to the nature of the materials present and their condition within the vadose
              zone.   If, for instance, the vadose zone is moderately fractured granite, the
              materials within the vadose zone will have only a slight impact on most
              pollutants entering the vadose zone. The protection provided will be a function
              of depth and the failure of critical fractures to interconnect.

                   If, however, the vadose zone is comprised of unfractured glacial till, it
              can  be   anticipated   that consumptive      sorption will    be moderately      high;
              infiltration will be moderately low; retardation will be significant; and with
              any substantial thickness of till , considerable time will be required for most
              pollutants to penetrate the till.       Thus it can be seen that the overlapping
              consideration of degradation, retardation, and attenuation      within the context of
              both depth to water and impact of the vadose zone is useful in the comparative
              evaluation of sites.

                   Net recharge determines, on an annual basis, the quantity of water from
              precipitation that is available for vertical transport, dispersion, and dilution
              of a pollutant from a specific point of application.        Net recharge exemplifies
              how some parameters can have both positive and negative effects.         For example,
              greater recharge typically means more rapid transport of a pollutant and
              therefore less time for attenuation.      However, in this situation, dilution is
              also greater, thereby exerting a positive influence because the concentration of
              an introduced pollutant will be lessened.         It is also evident that a thick
              unsaturated zone, with a layered sequence of bedded and fractured shales,
              sandstones, and limestones, can have a profound impact on all three of the same
              factors (transport, dispersion, dilution) that are of primary importance to net
              recharge.

                  Topography and soil media also influence net recharge. Topography has site-
              specific influence which determines whether the capacity for recharge is high or
              low at a given point.      The permeability of the surface soils has a similar
              impact.  However, the nature of the surface soil materials has an additional
              impact upon potential pollutant attenuation, consumptive sorption, route length
              and direction, and time available for penetration.

                  In addition to its direct influence upon recharge, topography exerts a
              significant influence upon soil thickness, drainage characteristics, and profile
              development.  For example, in high slope areas, wind and rain are more likely to
              erode the soil surface, diminishing the soil thickness. High slopes also result
              in faster runoff, allowing less time for infiltration to occur.          In addition,
              topography usually bears a predictable relationship to hydraulic gradient, and

                                                        9








             direction of probable pollutant movement under water table conditions, with a
             consequent impact on dispersion and dilution.

                  The upper portion of the vadose zone exerts influence on the type of soils
             developed on the surface. The vulnerability of an aquifer to a given pollution
             event varies in response to the nature of the materials in the vadose zone
             including but not limited to:        grain size, sorting, reactivity, bedding,
             fracturing, thickness, and sorptive character.      In general, finer grain-size
             materials, i.e., clays and silt, have lower hydraulic conductivity and greater
             capacity for the temporary and long-term attenuation of pollutants.             if
             expandable clay minerals are present, the sorptive capacity is further enhanced.
             If a material is even moderately cemented, then grain size and sorting may be
             less s.ignificant than the degree of cementation.

                  If the material in the vadose zone is reactive to the pollutant, or soluble
             in it, then there may be two different effects.      First, the pollutant may be
             retarded (a positive effect) or second, the solution of the vadose zone material
             may actually increase permeability and allow subsequent introduction of
             pollutants to pass through more quickly with less retardation (a negative
             effect). In the case of reactive pollutants, the importance of secondary by-
             products must be considered.   It is here that the risks associated with gaseous
             phase transport are most likely to have an impact on ground water.

                  The thickness of the vadose zone and the degree of fracturing and frequency
             of bedding planes in the vadose zone all impact upon the tortuosity, route
             length, dispersion, and consequent travel time that is required for a pollutant
             to move through the vadose zone.   This is not only of time-delay importance but
             also is important as the control of contact time for reactions to occur.

                  The vadose zone, including the surficial soil, is also of great importance
             as the zone where most of the biologic activity occurs.        There are natural
             organisms found in this zone that break down many polluting substances into
             secondary by-products, both harmless and harmful.      For many chemicals, these
             reactions are very poorly understood, if at all, but it is known that with
             sufficient time, the eventual results are generally beneficial. Among the best
             known of these processes at present are the bacterial fixation of iron and the
             bacterial breakdown of non-chlorinated hydrocarbons under natural conditions.
             Both of these processes occur in the vadose zone and in the aerobic portion of
             shallow aquifers.

                  The hydraulic conductivity, with the gradient of the aquifer beneath a site,
             influences the rate of movement of an introduced pollutant away from the point
             of introduction.    In conjunction with hydraulic gradient, conductivity also
             controls the direction of movement. These are, in turn, affected with regard to
             dispersion, by grain size, bedding, fracturing, and tortuosity.

             DRASTIC RANKING SYSTEM

                 A numeric ranking system to assess ground water pollution potential has been
             devised using the DRASTIC factors. The system contains three significant parts:
             weights, ranges, and ratings.


                                                    10




                                                                                                  i7-71
                                                                                                  I @"-
                    Each DRASTIC factor has been evaluated with respect to the other factors to
              balance the relative importance of each factor in determining an area's
              susceptibility to ground water pollution,. Each DRASTIC factor has been assigned
              a relative weight ranging from 1 to 5 as. shown in Table 1. Those DRASTIC factors
              with a weight of 5 have the greatest impact on whether or not an area is
              susceptible to ground water contamination.     Those with a weight of 1 have the
              least impact.


                              Table 1. Assigned Weights for DRASTIC Features


                                         Feature                                  Weight

                Depth to Water (D)                                                   5
                Net Recharge (R)                                                     4
                Aquifer Media (A)                                                    3
                Soil Media (S)                                                       2
                Topog aphy (T)                                                       I
                Impact of the Vadose Zone Media (1)                                  5
                Hydraulic Conductivity of the Aquif2L_LC)                            3



                   Each DRASTIC factor has been divided into the appropriate ranges or
              significant media type and then assigned a rating. The rating is based on the
              relative pollution potential impact of the range or media type given the factor
              being evaluated. The range for each DRASTIC factor has been assigned a rating
              which varies between 1 and 10 (Tables 2 - 8). The higher the rating, the higher
              the factor's contribution to the pollution potential. This information was not
              modified from the recommendations in the DRASTIC handbook.

                   This system allows the determination of a numeric value for an area by using
              an additive model. This number provides a representative value of the relative
              potential susceptibility to pollution of an area. The equation for determining
              the DRASTIC Index is:


                     PAW +RRRJ + M., + SRSW + TRTW + IR1W + CA =Pollution Potential










             where:

                   R         rating
                   W-        weight


                   The DRASTIC model was used to evaluate ground water pollution potential on
             a grid cell basis. The County was divided into 557 grid cells with a unit length
             of 3,500 feet (grid cell area = 281 acres).     Ratings were determined for each
             hydrogeologic parameter for each grid cell. The DRASTIC Index was then computed
             using the aforementioned equation in an overlay scheme as shown in Figure 2.

                   Once a DRASTIC Index has been computed, it is possible to identify areas
             which are relatively more likely to be susceptible to ground water contamination.
             The higher the DRASTIC Index, the greater the ground water pollution potential.
             The DRASTIC Index provides only a relative evaluation tool and is not designed
             to provide absolute answers such as pollutant loadings to aquifers and resulting
             ground water pollutant concentrations.


                             Table 2. Ranges and Ratings for Depth to Water

                                                 Weight: 5


                                            Depth to Water ("D")
                                Range               (feIet)            Rating

                                0  5                                      10

                                5  15                                     9

                               15  30                                     7

                               30  50                                     5

                               50  75                                     3

                             75  - 100                                    2

                                100+                                      1














                                                      12













                           Variable Weight
         GridCell  3
        Rating Codes 2 Z 5
                 '1101, 3 -"' 6--,7'
                 3  9

                            A    3
               @,@ @6@6
               Z"-- 2 @1    S    2
                 @5@3

                                 5
               ,"- @6@6
                 @4@2       C    3


                          DRAST7C Index




                   Figure 2
             DRASTIC Overlay Scheme



                      13











                                                                                                       NII
                                 Tabl e 3. Ranges and Ratings for Net Recharge

                                                   Weight: 4


                                               Net Recharge (  IIRII)
                                                   (inches/year)
                                  ange                                     Rating

                                 0   2                                       1

                                 2   4                                       3

                                 4   7                                       6

                                 7   10                                      8

                                  10+                                        9



                               Table 4. Ranges and Ratings for Aquifer      Media

                                                   Weight: 3


                                              Aquifer Media ("A")
                                 Range                           Rating         Typical Rating-

                            Massive Shale                        I - 3                 2
                        Metamorphic/Igneous                      2 - 5                 3
                   Weathered Metamorphic/Igneous                 3 - 5                 4
                            Glacial Till                         4 - 6                 5

                  Bedded Sandstone, Limestone and                5 - 9                 6
                           Shale Sequences
                         Massive Sandstone                       4 - 9                 6

                         Massive Limestone                       4 - 9                 6

                          Sand and Gravel                        4 - 9                 8

                               Basalt                            2 - 10                9

                          Karst Limestone                        9 - 10                 10










                                                       14








                                 Tabl e 5.  Ranges and Ratings for  Soil Media

                                                  Weight: 2


                                               Soil Media ("S")

                                 Range                                   Rating

                            Thin or Absent                                  10

                                 Gravel                                     10

                                 Sand                                       9

                                 Peat                                       8

                  Shrinking and/or.Aggregated Clay                          7
                             Sandy Loam                                     6

                                 Loam                                       5

                             Silty Loam                                     4
                              Clay Loam                                     3

                                 Muck                                       2
                Nonshrinking and Nonaggregated Clay                         I


                                 Table 6. Ranges and Ratings for Topography

                                                 Weight: 1


                                              Topography ("T")
                                               (Percent Slope)
                                 Range                T                 Rating

                                 0  2                                       10

                                 2  6                                       9

                                6   12                                      5

                               12   18                                      3

                                 18+                                        1









                                                     15








                        Tabl e 7.   Ranges and Ratings for Impact of the Vadose Zone Media

                                                        Weight: 5


                                        Impact of the Vadose Zone Media ("I")
                                    Range                         Rating Range         Typical Rating

                              Confining Layer                            2                     1
                                 Silt/Cl,ay                           2 -  6                   3
                                    Shale                             2  - 5                   3

                                 Limestone                            2  - 7                   6

                                 Sandstone                            4  - 8                   6
                  Bedded Limestone, Sandstone, Shale                  4  - 8                   6
                   Sand and Gravel with Significant                   4  - 8                   6
                              Silt and Clay
                           Metamorphic/Igneous                        2  - 8                   4
                             Sand and Gravel                          6  - 9                   8

                                   Basalt                             2  - 10                  9

                             Karst Limestone                          8 -  10                  10


                            Table 8. Ranges      and Ratings for Hydraulic Conductivity

                                                       Weight: 3


                                            Hydraulic Conductivity ("C")
                                                        (GpD/ft2)
                                   Range                                        Rating

                                   1    100                                        1

                                 100   300                                         2

                                 300    700                                        4

                                 700   1000                                        6

                                1000   2000                                        8

                                   2000+                                           10






                                                           16










             DRASTIC MODEL

                   DRASTIC was developed using four major assumptions:

                   1.   the pollutant is introduced at the ground surface;
                   2.   the pollutant is flushed into the ground water by precipitation;
                   3.   the pollutant has the mobility of water; and
                   4.   the area evaluated using DRASTIC is 100 acres or larger.


                   In evaluating specific project impacts, there may be special conditions
             which would need to be more fully evaluated.       For example, the methodology
             assumes that a pollutant will start at the surface, enter the soil, travel
             through the vadose zone, and enter the aquifer much like water.       However, a
             pollutant may have unique chemical and physical properties which would restrict
             movement into ground water-.   A pollutant may be denser than water and exhibit
             travel characteristics different from water.    Further, a disposal method which
             injects pollutants directly into ground water negates many of the natural
             attenuation mechanisms assumed in the methodology.      In this particular case,
             DRASTIC does not provide an accurate assessment of ground water pollution
             potential.

                   In assuming areas of 100 acres or larger, the DRASTIC method attempts to
             evaluate ground water pollution potential from an area-wide perspective rather
             than a site-specific focus.   For example, in an area of fractured rock, ground
             water flows in a general direction.   However, ground water flow at any one site
             will be directly controlled by fracture orientation.     In this scenario, exact
             direction of pollutant movement is controlled by a site-specific characteristic.
             Generally, however, the pollutant would still flow in a general direction.




















                                                    17















                                                  SECTION 4

                                   DATA COLLECTION AND RATING DEVELOPMENT


                   This section describes the data collection activities, interpretations, and
             assumptions used in developing DRASTIC parameter ratings.      Relevant references
             are cited.   The detailed data base is included as Appendix A while maps showing
             the distribution of DRASTIC parameter ratings are included in Appendix B.

             DEPTH TO WATER

                   The primary source of data on depth to water is the logs for approximately
             1,300 wells within the County.      The Virginia Water Control Board (VWCB) has
             compiled the well logs and entered the data into the EPA STORET data base. This
             data was downloaded to microcomputer and manipulated in order to develop the
             rating by grid cell.    Powell and Abe (1985) and Meng and Harsh (1988) provided
             supplemental information on depth to water.     A very shallow (0 - 5 feet) depth
             to water was assumed for wide, flat river and overbank areas. This shallow depth
             was also assumed for swamps.    Much of the Piedmont has a rating of 7 (depth to
             water of 15 - 30 feet) but the Coastal Plain varies greatly in rating.

             NET RECHARGE

                  Net recharge information was collected from numerous sources, including
             Aller, et al . (1987), Hamilton and Larson (1986), Harsh and Laczniak (1990),
             O'Brien anTGere (1991), Weston (1976), and Wagner, et al . (1988).            These
             references indicate that, in general, net recharge is betweer@-7 and 10 inches per
             year (rating of 8) in the Piedmont, and over 10 inches per year (rating of 9) in
             the Coastal Plain. Further refinements were made in the Piedmont, to account for
             the impact of topography.     In high slope areas, water moves faster along the
             surface, providing less time for infiltration. Also, higher slope areas tend to
             have larger outcroppings of  impermeable solid rock, since weathered material is
             easily transported away with wind and runoff. A net recharge of 4 - 7 inches per
             year (rating of 6) was used for areas with slopes between 12 and 18 percent, and
             a net recharge of 2 - 4 inches per year (rating of 3) was used where slope is
             greater than or equal to 18 percent.     In the Coastal Plain, 'the soil , vadose
             zone, and aquifer media is predominantly sand and silt, so topography has less
             impact on recharge-

             AQUIFER MEDIA

                  VWCB well data, along with Meng and Harsh (1988), were used to delineate the
             various aquifers within the County.     Meng and Harsh (1988) also describe the
             aquifer media, as do the following references:    Commonwealth of Virginia (1963,
             1971, and 1980), Mixon, et al. (1989), Mixon and Newell (1977), Mixon (1990),
             Pavlides (1976 and 1990), Powell and Abe (1985), Weston (1976), and Wagner, et

                                                     18








               al . (1988).   The Piedmont is predominantly weathered granite and gneiss, which
               correspond to the weathered metamorphic/igneous DRASTIC range (rating of 4).
               Fresh unweathered rack is exposed in high slope areas (assumed to be greater than
               or equal to 12 percent), corresponding to the metamorphic/igneous DRASTIC range
               (rating of 3). The Coastal Plain is predominantly sand and gravel. A rating of
               8 was applied to.the Potomac Aquifer, and 7 to the Aquia and Chickahominy/Piney
               Point aquifers. This difference in ratings accounts for the higher attenuation
               (lower hydraulic conductivity) in the Potomac, which could be caused by the size
               and orientation of clay lenses in the sand and gravel.

               SOIL MEDIA

                    Soil characteristics were derived from the County Soil Survey (Isgrig and
               Strobel, 1974).      Representative cores were reported for the various soil
               classifications. These cores were, in turn, used to develop DRASTIC ranges. The
               Coastal Plain soil media is sandy loam (rating of 6), and the sandy loam
               stretches into a small section of the southeastern Piedmont. The majority of the
               Piedmont has a clay loam (rating of 3) soil media.         The soil media was assumed
               to be thin or absent (rating of 10) in high slope areas (slopes greater than or
               equal to 12 percent).        This is consistent with the Soil Survey and is a
               reasonable assumption because soils erode to a far greater extent in high slope
               areas where they are carried away by runoff and wind.

               TOPOGRAPHY

                    Percent slope was determined by evaluating the Stafford County topographic
               map (U.S. Geological Survey, 1974).       Steep slopes form the flood boundary for
               parts of Aquia Creek, Accokeek Creek, Potomac Creek, Long Branch, and the
               Rappahannock River. Extremely flat areas can also be found, particularly in some
               river overbank areas and around Widewater Beach.


               IMPACT OF THE VADOSE ZONE MEDIA

                    A number of resources were      used to derive the vadose zone media in the
               Piedmont, including Aller, et al.     (1987), Mixon (1990), Pavlides (1976), Powell
               and Abe (1985), and Wagner, et al.    (1988). The vadose zone media in the Piedmont
               is predominantly sand and gravel     with significant silt and clay (rating of 5).
               In high slope areas (where slope is greater than or equal to 12 percent), the
               vadose zone media is assumed to be metamorphic/igneous (rating of 4) since high
               erosion leaves exposed bedrock.     The vadose zone media in the Coastal Plain was
               derived from Aller, et al. (1987), Meng and Harsh (1988), and Weston (1976). The
               vadose zone in the Coastal Plain is also sand and gravel with significant silt
               and clay, although there is far more sand in the Coastal Plain vadose zone than
               in the Piedmont. A rating of 7 was used for the Potomac Aquifer, and a rating
               of 6 was used for the Aquia and Chickahominy/Piney Point Aquifers. As with the
               aquifer media rating, this difference accounts for the higher attenuation (lower
               hydraulic conductivity) in the Potomac, which could be caused by the size and
               orientation of clay lenses in the vadose zone.





                                                         19









              HYDRAULIC.CONDUCTIVITY

                   Hydraulic conductivity was    derived from Harsh and Laczniak (1990) and
              Hamilton and Larson (1986).        Hydraulic conductivity in the Piedmont is
              approximately 50 gallons per day   per square foot (gpd/ ft2), corresponding to a
              rating of 1.      In the Coastal Plain,   2 the Aquia Aquifer has a hydraulic
              conductivity of approximately 110 gpd/ft (rating of 2), the Chickahominy/Piney
              Point Aquifer has a hydraulic conductivity of approximately 90 gpd/    ft2  (rating
              of 1), and the Potomac Aquifer has a hydraulic conductivity of approximately 400
              gpd/ ft2 (rating of 4). These values are not site-specific since conductivity can
              vary substantially within any of the aquifers present. Rather, these values are
              typical of the aquifers and are derived from very limited well pump tests and
              modeling studies.






































                                                     20
















                                                   SECTION 5

                                                    RESULTS



               STUDY SUNNARY

                    The ratings discussed in Section 4 form the basis for the composite DRASTIC
               index. The sum over the seven DRASTIC parameters of the product of the rating
               and the weight determine the index value as described in Section 2. These values
               were determined for each of the grid cells, as shown in Figure 8, and range from
               90 to 179.  In the Piedmont, the DRASTIC Index values generally range from 100
               to 130, while in the Coastal Plain, values range from 130 to 179. The fall line
               separates the two regions and is easily distinguished by the sharp break in
               DRASTIC values between the Piedmont and the Coastal Plain. The Coastal Plain has
               higher composite DRASTIC values, which is associated with greater pollution
               potential, because the sand and gravel in the soil, vadose zone, and aquifer
               media facilitate chemical transport as opposed to the metamorphic/igneous
               formations of the Piedmont. Within the Coastal Plain, the DRASTIC Index values
               are generally lower in the Aquia and Chickahominy/Piney Point Aquifers than in
               the Potomac Aquifer because of the increased attenuation provided by the aquifer
               and vadose zone media in these two aquifers. These results match very well with
               general DRASTIC ratings developed in the Prince William County study (Wagner, et
               al ., 1988) of 111 to 119 in the Piedmont and 127 to 182 in the Coastal Plain.

               SPREADSHEETS

                   Spreadsheets were developed to store grid cell data and determine ratings.
               The spreadsheets are presented in Appendix A. The first two columns specify the
               Virginia grid location of the center of each grid cell .    The third and fourth
               columns specify the depth to ground water and corresponding D rating for the grid
               cell , respectively. The regional aquifer system - Piedmont (P) or Coastal Plain
               (C) - is included in col.umn five. Column six specifies the net recharge rating,
               R. Column seven includes the specific aquifer - Piedmont, or, within the Coastal
               Plain, the Aquia, Chickahominy/Piney Point (CH/P), or Potomac Aquifer.         The
               aquifer media rating, A, and the soil media rating, S, are specified in columns
               eight and nine,   respectively.    The mean percent slope and corresponding
               topography rating, T, are included in columns ten and eleven, respectively. The
               impact of the vadose zone media rating, 1, is specified in column twelve.      The
               hydraulic conductivity (gpd/ft2 ) and corresponding rating, C, are specified in
               columns thirteen and fourteen, respectively.     The final column presents the
               composite DRASTIC Index for the individual grid cells.

               SURFER

                   SURFER (Golden Software, Inc., 1987) is a powerful software tool which can
               create two- and three-dimensional graphics.      SURFER was used to assist in

                                                      21








               interpreting data collected for this project. Much of the well data downloaded
               from the EPA STORET data base were mapped in various ways to assist in data
               collection.    SURFER was used to map the locations of the wells and the
               observations (such as depth to water) at the wells.       SURFER was also used to
               create surface    (topographic) maps of depth to water to assist in data
               interpolation. The figures presented in Appendix B were created with SURFER, and
               are examples of mapping observations (ratings) at sampling locations (grid
               cells).   Engineering judgment and literature review, along with the graphics
               created with SURFER, contributed to the development of the spreadsheets
               previously described.

               MAPPING DRASTIC RESULTS

                    The following presents the methodology for preparing the Ground         Water
               Pollution Potential Map of Stafford County.       The DRASTIC Index values were
               grouped into 3 ranges:   less than 125; 125 to 149; and 150 and greater.     These
               three ranges co 'rrespond to low, moderate, and high       relative ground   water
               pollution potential, respectively. Three ranges were chosen to enhance the   map's
               utility as a general policy tool for ground water protection.       Each of  these
               ranges has an associated shading pattern.    The grid cells were shaded according
               to the range within which their associated index values fall. Shading boundaries
               were smoothed  'to more accurately and aesthetically present the physical
               situation. The County boundary was also mapped.

                   The index values themselves are not included on the map since the shading
               indicates a general range.   The reason these values are not mapped is that the
               methodology is qualitative; quantitative comparisons of index values can lead to
               misapplication of results.   Grid cell tick marks and the corresponding Virginia
               grid location are included on the four sides of the map, which was drafted on
               reproducible mylar.   The map was created on a 1:36,000 scale, which directly
               overlays on the Stafford County planning maps.




















                                                      22
















                                                  SECTION 6


                               GROUND WATER RESOURCE PROTECTION OVERLAY AREAS


                   The goal of this Ground Water Resource Protection Program is to identify the
              relative ground water pollution potential of land areas throughout the County and
              to provide guidelines for protecting ground water quality as development occurs.
              In order for the County to protect the quantity and quality of its ground water
              resources, an overlay scheme is proposed.   The purpose of the overlay is not to
              place undo restrictions on future development, but rather to support land use
              decision making by focusing. data gathering and analysis efforts in those regions
              which are potentially most susceptible to ground water contamination. A further
              objective is to collect well data countywide to support the evaluation of ground
              water resources as a possible supplement in responding to projected water supply
              shortfalls.

                   Through the application of the DRASTIC methodology, ground water pollution
              potential has been evaluated throughout the County.      The resulting pollution
              potential (DRASTIC) index values have been grouped into three categories which
              correspond to areas of low, moderate, and high susceptibility to ground water
              pollution.  These categories form the basis for the ground water protection
              overlay guidelines. The guidelines detailed below account for the ground water
              contamination risks associated with certain land uses and how these risks must
              be managed according to the ground water pollution potential of a given area.
              However, developments should analyze their impact relative to each individual
              DRASTIC parameter as well as implementing strategies that address the overall
              recommendations of the appropriate overlay area.

              GUIDELINES FOR LOW GROUND WATER POLLUTION POTENTIAL AREAS

                  Those areas identified as being the least susceptible to ground water
              pollution are generally located west of 1-95 in the Piedmont Physiographic Region
              and impacting the Piedmont Aquifer. The depth to water is generally greater than
              15 feet with a net recharge of 7-10 inches per year.       The aquifer media is
              generally weathered metamorphic and igneous rock with the predominant soil media
              being clay and sandy loam.      These soil types relate to a low hydraulic
              conductivity as they do not have a great ability to transmit water to the water
              table. However, some isolated gravel areas are present that would be capable of
              effectively transmitting water to the water table.     The percent slope varies
              greatly throughout this overlay area.       The guidelines for areas of low
              susceptibility to ground water pollution are as follows:

                       Discourage the location of landfills and dumps unless they are
                       developed in such a manner as to ensure the protection of ground water
                       resources.




                                                     23








                           Discourage the location of industrial waste disposal sites.

                           Encourage the replacement of older underground storage tanks in a
                           manner and timeliness that is not detrimental to the economic
                           potential of small business owners.

                           Recommend mining operations utilize stormwater Best Management
                           Practices (BMPs) to prevent ground water degradation.

                           Recommend that the storage of petroleum, fertilizer, pesticide, and
                           other toxic substances occur only in containers specifically designed
                           and maintained for these activities.

                           Provide educational opportunities for the storage and application of
                           pesticides, fertilizers, and other toxic materials for agricultural,
                           commercial, industrial, and golf course use.

                           Establish a well- monitoring program to collect data from community
                           residential wells and commercial and industrial wells on the following
                           parameters:

                                average yield, elevation of water table, and monitoring results
                                for:     silica,   iron, manganese, calcium, magnesium, sodium,
                                potassium, bicarbonate, sulphate, chloride, fluoride, nitrate,
                                total dissolved solids, specific conductance (micromhos), pH,
                                fecal coliform bacteria, hardness as CaC03;

                                for new wells, include the following parameters:          static water
                                level   (unpumped level -measured), stabilized measured pumping
                                water level, stabilized yield, time to stabilized yield, water
                                zones.

                                for   commercial    and   industrial    wells,    include    pollutants
                                associated with the particular land use.

              GUIDELINES FOR    MODERATE GROUND WATER POLLUTION POTENTIAL AREAS

                    Those areas identified as being moderately susceptible to ground water
              pollution are generally located in the central and southeastern portions of the
              County in the Coastal Plain Physiographic Region and impacting the Aquia and
              @Chickahominy/Piney Point Aquifers.       The depth to water is greater than 15 feet
              with a net recharge of greater than 10 inches per year.            The aquifer media is
              generally sand and gravel with soils varying from sandy loams to gravel.                 In
              general, these soil types will transmit water at a higher rate (moderate
              hydraulic conductivity) than the areas of low pollution potential.           The percent
              slope varies greatly throughout the overlay area.           Additional guidelines are
              recommended for areas of moderate ground water pollution potential as follows:






                                                          24








                          All guidelines listed under low pollution potential areas.

                          Encourage the use and continued maintenance of BMPs for all       land uses
                          designed   in such a manner so that outlets are not                directing
                          infiltration at points were ground water contamination could occur.

                          Prevent runoff from impervious areas to be directed at points where
                          ground water contamination could occur.

                          Provide vegetated buffers for runoff from impervious.

                          Encourage clustering of developments with the preservation of large
                          undisturbed open areas.

                          Preserve existing vegetation during site development to increase the
                          filtration of pollutants prior to water entering the soil.

                          Regulate the concentration of animals in order to provide additional
                          filtration of nutrient-rich runoff that may degrade ground water
                          quality.

                          Encourage developments to disturb only the area necessary for the
                          desired use and limit the amount of runoff from the site.

                          Improve  land management      practices which     encourage the use       of
                          alternative materials, including the use of non-toxic materials, that
                          support infiltration on the developed site in the appropriate area.

                          Encourage public sewer connections for all land uses except:

                               recreational (active and passive);
                               agricultural;
                               low   intensity   commercial     (local   markets)   and     industrial
                               (warehouse); and
                               low density residential (>1 acre lots).

                          Encourage the continued periodic maintenance of individual sewage
                          disposal systems to provide for maximum treatment of wastewater.

                          Design public sewage treatment systems using best available technology
                          that provides for maximum treatment of wastewater.

                          Provide educational opportunities for the storage and application of
                          pesticides, fertilizers, and other toxic materials for all land uses.

             GUIDELINES FOR HIGH GROUND WATER POLLUTION POTENTIAL AREAS

                   Those areas identified as being the most susceptible to ground water
             pollution are generally located along the fall line. -The band of land area runs
             parallel to and inclusive of 1-95 and Jefferson Davis Highway (US-1) through the
             County.      In addition, the land area which would include the Aquia Harbor
             subdivision and the entire Widewater area from 1-95 to the peninsula is

                                                        25





                                                                                                171

              identified as a high ground water pollution potential area. This area generally
              relates to the Coastal Plain Physiographic Region impacting the Potomac Aquifer.
              The depth to water varies ranging from less than 5 feet to 30 feet with a net
              recharge of greater than 10 inches   per year.   The aquifer media is sand and
              gravel. This soil type relates to a  high hydraulic conductivity which provides
              for rapid transmission of water (and thus pollutants) to the water table.     The
              percent slope varies throughout the overlay area.     Additional guidelines are
              recommended for areas of high ground  water pollution potential as follows:

                   -    All guidelines  listed in  the low and moderate polluti  on potential
                        areas.

                   -    Discourage the establishment of automobile junkyards and salvage
                        operations.

                        Discourage the establishment of quarries, gravel pits, and other
                        surface mining operations.

                   -    Discourage the development of landfills and dumps.

                   -    Discourage the establishment of confined feedlots for livestock.

                   -    Develop more stringent controls for wastewater spray irrigation
                        operations.

                   -    Develop more stringent controls for underground and above ground
                        storage of petroleum, pesticide, fertilizer, and other toxic
                        materials.

                   -    Encourage public sewer connections for all land uses except:

                            recreational (active and passive);
                            agricultural ; and
                            very low density residential (>3 acre lots).


















                                                    26












                                                   GLOSSARY


              Aquifer    -    A waterbearing stratum of rock, sand, or gravel that has the
                              property of transmission.

              Attenuate  -    To reduce the severity of (concentration and/or volume of
                              pollutant, in this case).

              Clastic    -    Made of fragments of pre-existing rocks.

              Dilution   -    The action of diminishing in concentration.

              Dispersion -    The process of dissipating.

              Hydraulic Conductivity - The ability of the aquifer materials to transmit water.

              Igneous    -    Rock formed by the solidification of molten magma.

              Metamorphic     Rock which has been changed by pressure, heat, and water,
                              resulting in a more compact and more highly crystalline
                              condition.

              Net Recharge    The amount of precipitation which infiltrates through to the
                              water table.

              Tortuous   -    Marked by repeated twists, bends, or turns.

              Vadose Zone     The  zone   above  the   water  table   which   is  saturated    or
                              discontinuously saturated.





















                                                     27













                                                    REFERENCES


              1.   Al 1 er, Li nda, et al ., 1987. DRASTIC: A Standardi zed System for Eval uati ng
                   Ground Water P-ollution Potential Using Hydrogeologic Settings. EPA/600/2-
                   87/035.

              2.   Commonwealth of Virginia, 1963.        Geologic Map of Virginia, Division of
                   Mineral Resources.

              3.   Commonwealth of Virginia, 1971. Mineral Resources of Virginia, Division of
                   Mineral Resources.

              4.   Commonwealth of Virginia, 1980.       Geology of Oak Grove Core, Division of
                   Mineral Resources.

              5.   Commonwealth of Virginia, 1987 (revised 1990). A Ground Water Protection
                   Strategy for Virginia, State Water Control Board.

              6.   Golden Software, Inc., 1987, SURFER.

              7.   Hamilton, Pixie A., and Larson, Jerry D., 1986. Hydrogeology and Analysis
                   of the Ground-water Flow System in the Coastal Plain of Southeastern
                   Virginia, U.S. Geological Survey.

              8.   Harsh, John F., and Laczniak, Randall J., 1990.          Conceptual ization and
                   Analysis of Ground-Water Flow System in the Coastal Plain of Virginia and
                   Adjacent Parts of Maryland and North Carolina. Professional Paper 1404-F,
                   U.S. Geological Survey.

              9.   Isgrig, Dan, and Stroebel, Jr., Adolph, 1974. Soil Survey of Stafford and
                   King George Counties, Virginia. Soil Conservation Service.

              10.  Meng, Andrew A., III and Harsh,    John F., 1988. Hydrogeologic Framework of
                   the Virginia Coastal Plain.      Professional Paper 1404-C, U.S. Geological
                   Survey.

              11.  Mixon, Robert B., and Newell, Wayne L., 1977. Stafford Fault System:
                   Structures Documenting Cretaceous and Tertiary Deformation along the Fall
                   Line in Northeastern Virginia. Geology.
              12.  Mixon, Robert B., 1990.      Geologic Map of the Coastal Plain Part of the
                   Joplin Quadrangle, Stafford and Prince William-Counties, Virginia. Open
                   File Report 90-550, U.S. Geological Survey.

              13.  Mixon, Robert B., et al., 1989.         Geologic Map and Generalized Cross
                   Sections of the CoasFa_l Tlain and Adjacent Parts of the Piedmont, Virginia.
                   Miscellaneous Investigations Series Map 1-2033, U.S. Geological Survey.


                                                       28









             14.  O'Brien & Gere, 1991. Comprehensive Water Supply Study, Stafford County,
                  Virginia.

             15.  Pavlides, Louis, 1976. Piedmont Geology of the Fredericksburg, Virginia,
                  Area and Vicinity. U.S. Geological Survey.

             16.  Pavlides, Louis, 1990. Geology of Part of the Northern Virginia Piedmont.
                  Open File Report 90-548, U.S. Geological Survey.

             17.  Powell, John D., and Abe, Joseph M., 1985.     Availability and Quality of
                  Ground Water in the Piedmont Province of Virginia.         Water Resources
                  Investigations Report 85-4235, U.S. Geological Survey.

             18.  U.S. Geological Survey, 1974. Stafford County, Virginia, County Map Series
                  (Topographic).

             19.  Wagner, Terry D., et al., 1988. DRASTIC: A Demonstration Mapping Project;
                  Botetourt, Carroll, Henrico, Middlesex, Prince William, and Rockingham
                  Counties, Virginia.

             20.  Roy F. Weston, 1976. Areawide Waste Treatment Management Plan; Volume IV-
                  Geology and Ground Water Resources..       Rappahannock Area Development
                  Commission.



































                                                   29




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                                                                              STAFFORD COUNTY GROUNDWATER PROTECTION STUDY
                                                                                            SOUTH OF VA 269500
                                                                                             OCTOBER 18,1991
                                                          REGIONAL                          A         S                    T          I                   c       DRASTIC
                VA GRID VA GRID                           AQUIFER RECHARGE                                      MEAN                 IMP.    HYDRAULIC
                  E-W       N-S       DEPTH               SYSTEM     RATING   AQUIFER                 SOIL     SLOPE               VADOSE CONDUCT.
                -------     ------                                            - -----
                2317000     213500         45          5  C                   9AQUIA ----------- 7-------- 6--------  9-------- 5--------  6------ 110 --------2------ 135
                2320500     213500         45          5  C                   9AQUIA             7         6          1         10         6       110         2       140
                2324000     213500         45          5  C                   9AQUIA             7         6          4         9          6       110         2       139
                2327500     213500         45          5  C                   9AQUIA             7         6          4         9          6       110         2       139
                2331000     213500         40          5  C                   9AQUIA             7         6          9         5          6       110         2       135
                2334500     213500         35          5  C                   9AQUIA             7         6          4         9          6       110         2       139
                2310000     217000         40          5  c                   9AQUIA             7         6          4         9          6       110         2       139
                2313500     217000         40          5  C                   9AQUIA             7         6          1         10         6       110         2       140
                2317000     217000         45          5  C                   9AQUIA             7         6          1         10         6       110         2       140
                2320500     217000         50          5  C                   9AQUIA             7         6          1         10         6       110         2       140
                2324000     217000         40          5  C                   9AQUIA             7         6          4         9          6       110         2       139
                2327500     217000         35          5  C                   9AQUIA             7         6          1         10         6       110         2       140
                2331000     217000         30          7  C                   9AQUIA             7         6          4         9          6       110         2       149
                2334500     217000         30          7  C                   9AQUIA             7         6          4         9          6       110         2       149
                2306500     220500         35          5  C                   9AQUIA             7         6          4         9          6       110         2       139
                2310000     220500         35          5  C                   9AQUIA             7         6          4         9          6       110         2       139
                2313500     220500         40          5  C                   9AQUIA             7         6          1         10         6       110         2       140
                2317000     220500         40          5  C                   9AQUIA             7         6          4         9          6       110         2       139
                2320500     220500         40          5  c                   9AQUIA             7         6          4         9          6       110         2       139
                2324000     220500         30          7  C                   9AQUIA             7         6          4         9          6       110         2       149
                2327500     220500         20          7  C                   9AQUIA             7         6          4         9          6       110         2       149
                2331000     220500         20          7  C                   9AQUIA             7         6          4         9          6       110         2       149
                2306500     224000         30          7  C                   9AQUIA             7         6          4         9          6       110         2       149
                2310000     224000         30          7  C                   9AQUIA             7         6          4         9          6       110         2       149
                2313500     224000         35          5  C                   9AQUIA             7         6          9         5          6       110         2       135
                2317000     224000         35          5  C                   9AQUIA             7         6          4         9          6       110         2       139
                2320500     224000         25          7  C                   9AQUIA             7         6          4         9          6       110         2       149
                2324000     224000         20          7  C                   9CH/P              7         6          4         9          6       90          1       146
                2327500     224000         20          7  C                   9CH/P              7         6          4         9          6       90          1       146
                2331000     224000         20          7  C                   9CH/P              7         6          9         5          6       90          1       142
                2303000     227500         30          7  C                   9POTOMAC           8         6          1         10         7       400         4       164
                2306500     227500         30          7  C                   9AQUIA             7         6          4         9          6       110         2       149
                2310000     227500         30          7  C                   9AQUIA             7         6          4         9          6       110         2       149
                2313500     227500         35          5  c                   9AQUIA             7         6          9         5          6       110         2       135
                2317000     227500         30          7  C                   9AQUIA             7         6          4         9          6       110         2       149
                2320500     227500         30          7  C                   9CH/P              7         6          4         9          6       90          1       146
                2324000     227500         15          9  C                   9CH/P              7         6          4         9          6       90          1       156
                2327500     227500         20          7  C                   9CH/P              7         6          9         5          6       90          1       142
                2331000     227500         20          7  C                   9CH/P              7         6          4         9          6       90          1       146
                2299500     231000         50          5  C                   9POTOMAC           8         6          4         9          7       400         4       153
                2303000     231000         60          3  c                   9POT014AC          8         6          4         9          7       400         4       143
                2306500     231000         40          5  c                   9AQUIA             7         6          1         10         6       110         2       140
                2310000     231000         45          5  C                   9AQUIA             7         6          4         9          6       110         2       139
                2313500     231000         40          5  C                   9AQUIA             7         6          4         9          6       110         2       139
                2317000     231000         30          7  C                   9AQUIA             7         6          9         5          6       110         2       145
                2320500     231000         25          7  C                   9CH/P              7         6          4         9          6       90          1       146
                2324000     231000         20          7  c                   9CH/P              7         6          4         9          6       90          1       146
                2327500     231000         20          7  C                   9CH/P              7         6          4         9          6       90          1       146






                                                         REGIONAL                            A          S                    T                             C     DRASTIC
               VA GRID VA GRID                           AQUIFER RECHARGE
                 E-W        N-S       DEPTH                                                                     MEAN                 IMP.   HYDRAULIC
                                                          SYSTEM     RATING   AQUIFER                 SOIL      SLOPE
                                                                                                                     -----------------------------------------------
              ----------------------------------------------------------------------------------------                             VADOSE CONDUCT.
              2331000     231000         40          5C                  9 CH/P                7        6            9        5         6       90          1       132
              2278500     234500         25          7P                  3 PIEDMONT            3        10       18           1         4       50          1       100
              2299500     234500         70          3c                  9 POTOMAC             a        6            9        5         7      400          4       139
              2303000     234500         40          5C                  9 POTOMAC             8        6            4        9         7      400          4       153
              2306500     234500         40          5C                  9 AQUIA               7        6            4        9         6      110          2       139
              2310000     234500         45          5C                  9 AQUIA               7        6            4        9         6      110          2       139
              2313500     234500         55          3C                  9 AQUIA               7        6            9        5         6      110          2       125
              2317000     234500         45          5C                  9 AQUIA               7        6            9        5         6      110          2       135
              2320500     234500         45          5c                  9 CH/P                7        6            4        9         6       90          1       136
              2324000     234500         25          7c                  9 CH/P                7        6            4        9         6       90          1       146
              2327500     234500         25          7c                  9 CH/P                7        6            9        5         6       90          1       142
              2331000     234500         50          5c                  9 CH/P                7        6            9        5         6       90          1       132
              2334500     234500         50          5C                  9 AQUIA               7        10       15           3         6      110          2       141
              2275000     238000         25          7P                  3 PIEDMONT            3        10       18           1         4       50          1       100
              2278500     238000         25          7P                  3 PIEDMONT            3        10       18           1         4       50          1       100
              2292500     238000         70          3P                  8 PIEDMONT            4        6            9        5         5       50          1       104
              2296000     238000         70          3c                  9 POTOMAC             8        6            4        9         7      400          4       143
              2299500     238000         50          5C                  9 POT014AC            8        6            1       10         7      400          4       154
              2303000     238000         35          5C                  9 POTOMAC             8        6            9        5         7      400          4       149
              2306500     238000         35          5C                  9 AQUIA               7        6            4        9         6      110          2       139
              2310000     238000         35          5C                  9 AQUIA               7        6            4        9         6      110          2       139
              2313500     238000         45          5C                  9 AQUIA               7        6            4        9         6      110          2       139
              2317000     238000         40          5c                  9 cm/P                7        6            4        9         6       90          1       136
              2320500     238000         25          7C                  9 CH/P                7        6            4        9         6       90          1       146
              2324000     238000         15          9C                  9 CH/P                7        6            9        5         6       90          1       152
              2327500     238000         25          7c                  9 CH/P                7        10       15           3         6       90          1       148
              2331000     238000         35          5C                  9 AQUIA               7        10       15           3         6      110          2       141
              2334500     238000         50          5C                  9 AQUIA               7        10       15           3         6      110          2       141
              2271500     241500         25          7P                  8 PIEDMONT            4        6            9        5         5       50          1       124
              2275000     241500         25          7P                  8 PIEDMONT            4        6            9        5         5       50          1       124
              2278500     241500         25          7P                  8 PIEDMONT            4        6            9        5         5       50          1       -124
              2282000     241500         25          7P                  3 PIEDMONT            3        10       18           1         4       50          1       100
              2285500     241500         30          7P                  6 PIEDMONT            3        10       15           3         4       50          1       114
              2289000     241500         45          5P                  8 PIEDMONT            4        6            9        5         5       50          1       114
              2292500     241500         65          3P                  8 PIEDMONT            4        6            4        9         -5      50          1       108
              2296000     241500         35          5C                  9 POTOMAC             8        6            9        5         7      400          4       149
              2299500     241500         25          7C                  9 POTOMAC             8        6            9        5         7      400          4       159
              2303000     241500         25          7C                  9 POTOMAC             8        6            4        9         7      400          4       163
              2306500     241500         35          5C                  9 AQUIA               7        6            4        9         6      110          2       139
              2310000     241500         45          5c                  9 AQUIA               7        6            4        9         6      110          2       139
              2313500     241500         45          5c                  9 AQUIA               7        6            4        9         6      110          2       139
              2317000     241500         45          5C                  9 CH/P                7        6            4        9         6       90          1       136
              2320500     241500         25          7C                  9 CH/P                7        6            9        5         6       90          1       142
              2324000     241500         35          5C                  9 CH/P                7        10       15           3         6       90          1       138
              2327500     241500         30          7C                  9 CH/P                7        10       15           3         6       90          1       148
              2331000     241500         25          7C                  9 AGUIA               7        10       15           3         6      110          2       151
              2334500     241500         55          3C                  9 AQUIA               7        10       18           1         6      110          2       129
              2257500     245000         35          5P                  6 PIEDMONT            3        10       15           3         4       50          1       104
              2261000     245000         35          5P                  6 PIEDMONT            3        10       15           3         4       50          1       104
              2268000     245000         35          5P                  8 PIEDMONT            4        6            9        5         5       50          1       1%
              2271500     245000         35          5P                  6 PIEDMONT            3        10       15           3         4       50          1       104





                                                  D       REGIONAL     R                    A           S                    T                             C      DRASTIC
               VA GRID VA GRID                            AQUIFER RECHARGE                                       MEAN                 IMP.  HYDRAULIC
                 E-W        N-S       DEPTH               SYSTEM     RATING   AQUIFER                 SOIL      SLOPE               VADOSE CONDUCT.
               ----------------------------------         ----------------------------------------------------------------------------------------------------
               2275000    245000         25           7   P               8 PIEDMONT           4          6          4         9         5        50          1       128
               2278500    245000         25           7   p               8 PIEDMONT           4          6          9         5         5        50          1       124
               2282000    245000         25           7   P,              8 PIEDMONT           4          6          9         5         5        50          1       124
               2285500    245000         20           7   p               8 PIEDMONT           4          6          9         5         5        50          1       124
               2289000    245000         25           7   p               8 PIEDMONT           4          6          4         9         5        50          1       128
               2292500    245000         60           3   P               8 PIEDMONT           4          6          4         9         5        50          1       108
               2296000    245000         so           5   c               9 POTOMAC            8        10        15           3         7        400         4       155
               2299500    245000         40           5   c               9 POTOMAC            8          6          9         5         7        400         4       149
               2303000    245000         25           7   c               9 POTOMAC            8          6          9         5         7        400         4       159
               2306500    245000         30           7   c               9 AQUIA              7          6          4         9         6        110         2       149
               2310000    245000         50           5   C               9 AQUIA              7          6          9         5         6        110         2       135
               2313500    245000         60           3   c               9 AQUIA              7          6          9         5         6        110         2       125
               2317000    245000         40           5   C               9 AQUIA              7          6          9         5         6        110         2       135
               2320500    245000         30           7   C               9 CH/P               7        10        is           3         6        90          1       148
               2324000    245000         40           5   C               9 CH/P               7        10        15           3         6        90          1       138
               2327500    245000         25           7   c               9 CH/P               7        10        15           3         6        90          1       148
               2331000    245000         25           7   c               9 AQUIA              7        10        15           3         6        110         2       151
               2334500    245000         30           7   C               9 AQUIA              7        10        15           3         6        110         2       151
               2257500    248500         25           7   P               6 PIEDMONT           3        10        15           3         4        so          1       114
               2261000    248500         30           7   P               6 PIEDMONT           3        10        15           3         4
               2264500    248500         35                                                                                                       50          1       114
                                                      5   p               8 PIEDMONT           4          3          4         9         5        50          1       112
               2268000    248500         40           5   p               6 PIEDMONT           3        10        15           3         4        50          1       104
               2271500    248500         45           5   p               6 PIEDMONT           3        10        15           3         4        50          1       104
               2275000    248500         30           7   p               8 PIEDMONT           4          6          9         5         5        50          1       124
               2278500    248500         25           7   P               8 PIEDMONT           4          6          9         5         5        50          1       124
               2282000    248500         25           7   P               8 PIEDMONT           4          6          9         5         5        50          1       124
               2285500    248500         15           9   p               8 PIEDMONT           4          6          4         9         5        50          1       138
               2289000    248500         20           7   P               8 PIEDMONT           4          6          1       10          5        50          1       129
               2292500    248500         45           5   P               8 PIEDMONT           4          6          9         5         5        50          1       114
               2296000    248500         45           5   P               8 PIEDMONT           4          6          9         5         5        50          1       114
               2299500    248500         so           5   C               9 POTOMAC            8          6          9         5         7        400         4       149
               2303000    248500         35           5   c               9 POTOMAC            8          6          9         5         7        400         4       149
               2306500    248500         35           5   c               9 AQUIA              7        10        15           3         6        110         2       141
               2310000    248500         35           5   c               9 AQUIA              7        10        15           3         6        110         2       141
               2313500    248500         25           7   C               9 AQUIA              7        10        15           3         6        110         2       151
               2317000    248500         25           7   C               9 AQUIA              7        10        15           3         6        110         2       151
               2320500    248500         25           7   c               9 CH/P               7        10        15           3         6        90          1       148
               2324000    248500         25           7   c               9 CH/P               7          6          4         9         6        90          1       146
               2327500    248500         25           7   c               9 CH/P               7          6          1       10          6        90          1       147
               2331000    248500         25           7   C               9 AQUIA              7          6          1       10          6        110         2       150
               2334500    248500         25           7   C               9 AQUIA              7          6          1       10          6        110         2       150
               2257500    252000         25           7   P               6 PIEDMONT           3        10        15           3         4        50          1       114
               2261000    252000         30           7   P               6 PIEDMONT           3        10        15           3         4        50          1       114
               2264500    252000         35           5   P               6 PIEDMONT           3        10        15           3         4        50          1       104
               2268000    252000         35           15  P               6 PIEDMONT           3        10        15           3         4        50          1       104
               2271500    252000         35           5   P               8 PIED14ONT          4          6          9         5         5        50          1       1%
               2275000    252000         35           5   P               8 PIEDMONT           4          6          9         5         5        50          1       114
               2278500    252000         20           7   P               8 PIEDMONT           4          6          9         5         5        50          1       124
               2282000    252000         15           9   P               8 PIEDMONT           4          6          9         5         5        50          1       134
               2285500    252000         15           9   P               8 PIEDMONT           4          6          4         9         5        50          1       138
               2289000    252000         25           7   P               8 PIEDMONT           4          6          9         5         5        50          1       124






                                                           REGIONAL                           A           S                    T                              C      DRASTIC
               VA GRID VA GRID                             AQUI FER   RECHARGE
                  E-W       N-S        DEPTH               SYSTEM      RATING    AQUIFER                           MEAN                 IMP.  HYDRAULIC
               ------------------------------                                                           SOIL      SLOPE               VADOSE CONDUCT.
                                                  ---------------------------------------------------------------------------------------------------------
               2292500     252000          25          7   P                 8PIEDMONT            4         6          4          9         5        50          1       128
               2296000     252000          25          7   P                 8PIEDMONT            4         6          4          9         5        50          1       128
               2299500     252000          35          5   C                 9POTOMAC             a         6          9          5         7      400           4       149
               2303000     252000          30          7   C                 9POTOMAC             8         6          9          5         7      400           4       159
               2306500     252000          35          5   C                 9AQUIA               7         6          9          5         6      110           2       135
               2310000     252000          40          5   C                 9AQUIA               7       10         15           3         6      110           2       141
               2313500     252000          50          5   C                 9AQUIA               7         6          4          9         6      110           2       139
               2317000     252000           5        10    C                 9AQUIA               7         6          1       10           6      110           2       165
               2320500     252000           5        10    c                 9CH/P                7         6          1       10           6        90          1-      162
               2324000     252000           5        10    c                 9CH/P                7         6          9          5         6        90          1       157
               2327500     252000          30          7   C                 9CH/P                7       10         18           1         6        90          1       146
               2331000     252000          30          7   C                 9AQUIA               7       10         18           1         6      110           2       149
               2334500     252000          30          7   C                 9AQUIA               7       10         18           1         6      110           2       149
               2338000     252000          35          5   C                 9AQUIA               7       10         15           3         6      110           2       141
               2341500     252000          30          7   C                 9AQUIA               7         6          9          5         6      110           2       145
               2345000     252000          25          7   C                 9AQUIA               7         6          4          9         6      110           2       149
               2254000     255500          25          7   P                 8PIEDMONT            4         3          9          5         5        50          1       118
               2257500     255500          25          7   P                 8PIEDMONT            4         3          9          5         5        50          1       118
               2261000     255500          30          7   P                 6PIEDMONT            3       10         Is           3         4        50          1       114
               2264500     255500          30          7   P                 6PIEDMONT            3       10         15           3         4        50          1       114
               2268000     255500          20          7   P                 8PIEDMONT            4         3          9          5         5        so          1       118
               2271500     255500          25          7   P                 8PIEDMONT            4         6          9          5         5        50          1       124
               2275000     255500          25          7   P                 8PIEDMONT            4         6          9          5         5        50          1       124
               2278500     255500          25          7   P                 8PIEDMONT            4         6          9          5         5        50          1       124
               2282000     255500          25          7   P                 8PIEDMONT            4         6          9          5         5        50          1       124
               2285500     255500          25          7   P                 8PIEDMONT            4         6          9          5         5        50          1       124
               2289000     255500          30          7   P                 8PIEDMONT            4         6          9          5         5        50          1       124
               2292500     255500          35          5   P                 8PIEDMONT            4         6          4          9         5        50          1       118
               2296000     255500          40          5   C                 9POTOMAC             8         6          4          9         7      400           4       153
               2299500     255500          30          7   C                 9POTOMAC             8         6          9          5         7      400           4       159
               2303000     255500          30          7   C                 9POTOMAC             8       10         15           3         7      400           4       165
               2306500     255500          40          5   C                 9AQUIA               7       10         15           3         6      110           2       141
               2310000     255500           5        10    C                 9AQUIA               7         6          1       10           6      110           2       165
               2313500     255500          50          5   C                 9AQUIA               7         6          9          5         6      110           2       135
               2317000     255500          40          5   C                 9AQUIA               7         6          9          5         6      110           2       135
               2320500     255500          40          5   C                 9CH/P                7       10         15           3         6        90          1       138
               2324000     255500          40          5   C                 9CH/P                7       10         18           1         6        90          1       136
               2327500     255500          40          5   C                 9AQUIA               7       10         18           1         6      110           2       139
               2331000     255500          40          5   C                 9AQUIA               7       10         18           1         6      110           2       139
               2334500     255500          40          5   C                 9AQUIA               7       10         18           1         6      110           2       139
               2338000     255500          45          5   C                 9AQUIA               7       10         18           1         6      110           2       139
               2341500     255500           5        10    C                 9AQUIA               7         6          4          9         6      110           2       164
               2345000     255500          30          7   C                 9AQUIA               7         6          4          9         6      110           2       149
               2254000     259000          25          7   P                 8PIEDMONT            4         3          9          5         5        50          1       118
               2257500     259000          25          7   P                 8PIEDMONT            4         3          4          9         5        50          1       122
               2261000     259000          30          7   P                 8PIEDMONT            4         3          9          5         5        50          1       118
               2264500     259000          30          7   P                 8PIEDMONT            4         3          9          5         5        50          1       lis
               2268000     259000          20          7   P                 8PIED14ONT           4         3          4          9         5        50          1       122
               2271500     259000          25          7   P                 8PIEDMONT            4         3          4          9         5        50          1       122
               2275000     259000          25          7   P                 8PIEDMONT            4         6          9          5         5        so          1       124
               2278500     259000          25          7   P                 8PIEDMONT            4         6          9          5         5        50          1       124






                                                      REGIONAL     R                  A          S                 T        I                  C     DRAST I C
                VA GRID VA GRID                       AQUIFER RECHARGE                                  MEAN               I MP.  HYDRAULIC
                 E-W       N-S      DEPTH             SYSTEM     RATING   AQUIFER              SOIL     SLOPE             VADOSE CIONOWT.
              ---------------------------------------------------------------------------------------------------------------------------------------
                2282000    259000        25         7 P               8 PIEDMONT         4        6         9         5         5      50         1      124
                2285500    259000        25         7 P               8 PIEDMONT         4        6         9         5         5      50         1      124
                2289000    259000        35         5 P               8 PIEDMONT         4        6         9         5         5      50         1      114
                2292500    259000        35         5 C               9 POTOMAC          8        6         9         5         7     400         4      149
                2296000    259000        45         5 C               9 POTOMAC          8       10        15         3         7     400         4      155
                2299500    259000        45         5 C               9 POTOMAC          8        6         9         5         7     400         4      149
                2303000    259000        5        10  C               9 POTOMAC          8        6         4         9         7     400         4      178
                2306500    259000        5        10  C               9 AQUIA            7        6         4         9         6     110         2      164
                2310000    259000        45         5 C               9 AQUIA            7       10        15         3         6     110         2      141
                2313500    259000        45         5 C               9 AQUIA            7        6         9         5         6     110         2      135
                2317000    259000        40         5 C               9 AQUIA            7        6         9         5         6     110         2      135
                2320500    259000        40         5 C               9 AQUIA            7        6         9         5         6     110         2      135
                2324000    259000        40         5 C               9 AQUIA            7       10        18         1         6     110         2      139
                2327500    259000        40         5 C               9 AQUIA            7       10        15         3         6     110         2      141
                2331000    259000        40         5 C               9 AQUIA            7        6         9         5         6     110         2      135
                2334500    259000        5        10  C               9 AQUIA            7        6         4         9         6     110         2      164
                2338000    259000        5        10  C               9 AQUIA            7        6         4         9         6     110         2      164
                2341500    259000        35         5 C               9 AQUIA            7        6         9         5         6     110         2      135
                2345000    259000        30         7 C               9 AQUIA            7       10        15         3         6     110         2      151
                2250500    262500        25         7 P               3 PIEDMONT         3       10        is         1         4      50         1      100
                2254000    262500        25         7 P               6 PIEDMONT         3       10        15         3         4      50         1      114
                2257500    262500        30         7 P               8 PIEDMONT         4        3         9         5         5      50         1      118
                2261000    262500        30         7 P               8 PIEDMONT         4        3         4         9         5      50         1      122
                2264500    262500        25         7 P               8 PIEDMONT         4        3         9         5         5      50         1      118
                2268000    262500        20         7 P               8 PIEDMONT         4        3         9         5         5      50         1      118
          Ln    2271500    262500        25         7 P               8 PIEDMONT         4        3         4         9         5      50         1      122
                2275000    262500        25         7 P               8 PIEDMONT         4        3         1        10         5      50         1      123
                2278500    262500        20         7 P               8 PIEDMONT         4        3         4         9         5      50         1      122
                2282000    262500        25         7 P               8 PIEDMONT         4        3         9         5         5      50         1      118
                2285500    262500        30         7 P               8 PIEDMONT         4        3         9         5         5      50         1      118
                2289000    262500        40         5 p               8 PIEDMONT         4        6         9         5         5      50         1      114
                2292500    262500        45         5 C               9 POTOMAC          8        6         9         5         7     400         4      149
                2296000    262500        5        10  C               9 POTOMAC          8        6         4         9         7     400         4      178
                2299500    262500        35         5 C               9 POTOMAC          8        6         9         5         7     400         4      149
                2303000    262500        20         7 c               9 POTOMAC          8        6         9         5         7     400         4      159
                2306500    262500        40         5 C               9 AQUIA            7        6         9         5         6     110         2      135
                2310000    262500        35         5 C               9 AQUIA            7        6         9         5         6     110         2      135
                2313500    262500        35         5 C               9 AQUIA            7        6         9         5         6     110         2      135
                2317000    262500        25         7 C               9 AQUIA            7        6         9         5         6     110         2      145
                2320500    262500        30         7 C               9 AQUIA            7        6         9         5         6     110         2      145
                2324000    262500        40         5 c               9 AQUIA            7        6         9         5         6     110         2      135
                2327500    262500        40         5 C               9 AQUIA            7       10        18         1         6     110         2      139
                2331000    262500        40         5 C               9 AQUIA            7       10        18         1         6     110         2      139
                2334500    262500        45         5 C               9 AQUIA            7       10        18         1         6     110         2      139
                2338000    262500        50         5 C               9 AQUIA            7       10        18         1         6     110         2      139
                2341500    262500        35         5 C               9 AQUIA            7       10        15         3         6     ilo         2      141
                2247000    266000        25         7 P               8 PIEDMONT         4        3         9         5         5      50         1      118
                2250500    266000        25         7 P               6 PIEDMONT         3       10        15         3         4      50         1      114
                2254000    266000        25         7 P               6 PIEDMONT         3       10        15         3         4      50         1      114
                2257500    266000        25         7 P               8 PIEDMONT         4        3         9         5         5      50         1      118
                2261000    266000        25         7 P               8 PIEDMONT         4        3         4         9         5      50         1      122






                                                           REGIONAL                           A           S                    T                              C      DRASTIC
               VA GRID VA GRID                             AQU I FER  RECHARGE                                     MEAN
                  E-W       N-S        DEPTH               SYSTEM      RATING   AQU I FER               SOIL      SLOPE                  IMP.  HYDRAULIC
                                                                                                         ---------------    -------------------------------------------
                                                                                                                                      VADOSE CONDUCT.
               2264500     266000         25          7  P                  8 PIED14ONT          4          3          9          5         5       50           1       118
               2268000     266000         25          7  P                  8 PIEDMONT           4          3          9          5         5       50           1       118
               2271500     266000         25          7  P                  8 PIEDMONT           4          3          9          5         5       50           1       118
               2275000     266000         25          7  P                  8 PIEDMONT           4          3          4          9         5       50           1       122
               2278500     266000         30          7  P                  8 PIEDMONT           4          3          9          5         5       50           1       118
               2282000     266000         30          7  P                  6 PIEDMONT           3        10         15           3         4       50           1       114
               2285500     266000         35          5  P                  6 PIEDMONT           3        10         15           3         4       50           1       104
               2289000     266000         40          5  P                  6 PIEDMONT           3        10         15           3         4       so           1       104
               2292500     266000         45          5  P                  3 PIEDMONT           3        10         18           1         4       50           1         90
               2296000     266000         45          5  P                  6 PIEDMONT           3        10         15           3         4       50           1       104
               2299500     266000         35          5  C                  9 POTOMAC            8        10         15           3         7       400          4       155
               2303000     266000         30          7  C                  9 POTOMAC            8        10         15           3         7       400          4       165
               2306500     266000         30          7  C                  9 AQUIA              7          6          9          5         6       110          2       145
               2310000     266000         35          5  C                  9 AQUIA              7          6          9          5         6       110          2       135
               2313500     266000         35          5  C                  9 AQUIA              7          6          9          5         6       110          2       135
               2317000     266000         30          7  C                  9 AQUIA              7        10         15           3         6       110          2       151
               2320500     266000         45          5  C                  9 AQUIA              7        10         15           3         6       110          2       141
               2324000     266000         35          5  C                  0 AQUIA              7        10         15           3         6       110          2       141
               2327500     266000         35          5  C                  9 AQUIA              7        10         18           1         6       110          2       139
               2331000     266000         35          5  C                  9 AQUIA              7        10         18           1         6       110          2       139
               2334500     266000         25          7  C                  9 AQUIA              7        10         18           1         6       110          2       149
               2338000     266000         25          7  C                  9 AQUIA              7          6          1         10         6       110          2       150













                                                                            STAFFORD COUNTY GROUNDWATER PROTECTION STUDY
                                                                                           NORTH OF VA 269500
                                                                                            OCTOBER 18, 1991
                                                 D       REGIONAL     R                    A          S                   T          I                    C      DRASTIC
              VA GRID VA GRID                            AQUIFER RECHARGE                                      MEAN                IMP.    HYDRAULIC
                 E-W       N-S      DEPTH                SYSTEM     RATING   AQUIFER AQ.   MEDIA     SOIL      SLOPE              VADOSE CONDUCT.
              ---------------------------------------------------------------------------------------------------------------------------------------
              2247000     269500         20           7  P                  6PIEDMONT           3         10         15        3         4       50           1      114
              2250500     269500         20           7  p                  8PIEDMONT           4         3          9         5         5       50           1      118
              2254000     269500         20           7  P                  8PIEDMONT           4         3          9         5         5       so           1      118
              2257500     269500         25           7  P                  8PIEDMONT           4         3          9         5         5       50           1      118
              2261000     269500         20           7  P                  8PIEDMONT           4         3          9         5         5       50           1      118
              2264500     269500         25           7  P                  8PIEDMONT           4         3          9         5         5       50           1      118
              2268000     269500         25           7  P                  8PIEDMONT           4         3          4         9         5       50           1      122
              2271500     269500         25           7  P                  8PIEDMONT           4         3          4         9         5       50           1      122
              2275000     269500         25           7  P                  8PIEDMONT           4         3          9         5         5       50           1      118
              2278500     269500         30           7  P                  8PIEDMONT           4         3          4         9         5       50           1      122
              2282000     269500         30           7  p                  8PIEDMONT           4         3          9         5         5       50           1      118
              2285500     269500         35           5  P                  6PIEDMONT           3         10         is        3         4       50           1      104
              2289000     269500         45           5  P                  6PIEDMONT           3         10         15        3         4       50           1      104
              2292500     269500         50           5  P                  6PIEDMVT            3         10         is        3         4       50           1      104
              2296000     269500         50           5  c                  9POTOMAC            a         10         is        3         7      400           4      155
              2299500     269500         45           5  C                  9POTOMAC            8         6          9         5         7      400           4      149
              2303000     269500
                                         40           5  c                  9POTOMAC            8         6          9         5         7      400           4      149
              2306500     269500         40           5  c                  9POTOMAC            a         6          9         5         7      400           4      149
              23100,00    269500         40           5  C                  9AQUIA              7         6          9         5         6      110           2      135
              2313500     269500         40           5  C                  9AQUIA              7         10         15        3         6      110           2      141
              2317000     269500         40           5  C                  9AQUIA              7         10         15        3         6      110           2      141
              2320500     269500         30           7  C                  9AQUIA              7         10         15        3         6      110           2      151
              2324000     269500         30           7  c                  9AQUIA              7         10         18        1         6      110           2      149
              2327500     269500         25           7  c                  9AQUIA              7         10         18        1         6      110           2      149
              2331000     269500         20           7  c                  9AQUIA              7         10         18        1         6      110           2      149
              2334500     269500         20           7  c                  9AQUIA              7         10         is        3         6      110           2      151
              2338000     269500         20           7  C                  9AQUIA              7         6          1        10         6      lio           2      150
              2341500     269500         20           7  C                  9AQUIA              7         6          1        10         6      110           2      150
              2247000     273000         20           7  P                  8PIEDMONT           4         3          9         5         5       50           1      lie
              2250500     273000         20           7  P                  8PIEDMONT           4         3          9         5         5       50           1      118
              2254000     273000         20           7  P                  8PIEDMONT           4         3          9         5         5       50           1      118
              2257500     273000         30           7  P                  8PIEDMONT           4         3          9         5         5       50           1      118
              2261000     273000         30           7  P                  8PIEDMONT           4         3          9         5         5       50           1      118
              2264500     273000         30           7  P                  8PIEDMONT           4         3          9         5         5       50           1      118
              2268000     273000         30           7  P                  8PIEDMONT           4         3          4         9         5       50           1      122
              2271500     273000         30           7  P                  8PIEDMONT           4         3          9         5         5       50           1      118
              2275000     273000         25           7  P                  8PIEDMONT           4         3          4         9         5       50           1      122
              2278500     273000         25           7  P                  8PIEDMONT           4         3          4         9         5       50           1      122
              2282000     273000         20           7  P                  8PIEDMONT           4         3          4         9         5       50           1      122
              2285500     273000         30           7  P                  6PIEDMONT           3         10         15        3         4       50           1      114
              2289000     273000         40           5  P                  3PIEDMONT           3         10         18        1         4       50           1        90
              2292500     273000         45           5  P                  3PIEDMONT           3         10         18        1         4       50           1        90
              2296000     273000         40           5  c                  9POTOMAC            a         10         15        3         7      400           4      155
              2299500     273000         40           5  c                  9POTOMAC            a         6          9         5         7      400           4      149
              2303000     273000         55           3  c                  9POTOMAC            a         6          9         5         7      400           4      139
              2306500     273000         65           3  C                  9POTOMAC            8         6          9         5         7      400           4      139
              2310000     273000         65           3  C                  9POTOMAC            a         6          9         5         7      400           4      139
              2313500     273000         50           5  C                  9AQUIA              7         6          9         5         6      110           2      135






                                                         D        REGIONAL       R                      A             S                       T                                C      DRAST I C
                  VA GRID VA GRID                                 AVAJIFER RECHARGE                                            MEAN                   IMP.    HYDRAULIC
                    E-W         N-S         DEPTH                 SYSTEM     RAT I NG   AQU I FER                  SOIL       SLOPE                 VADOSE CONDUCT.
                  ---------------------------------------------------------------------------------------------------------------------------------------
                  2317000     273000           55            3    C                9  AQUIA                 7         6             9         5           6       110            2       125
                  2320500     273000           45            5    C                9  AQU I A               7         10         15           3           6       110            2       141
                  2324000     273000           45            5    C                9  AQUIA                 7         10         18           1           6       110            2       139
                  2327500     273000           20            7    C                9  AQUIA                 7         10         18           1           6       110            2       149
                  2331000     273000           is            9    C                9  AQUIA                 7         10         18           1           6       110            2       159
                  2334500     273000           15            9    C                9  AQUIA                 7         6             4         9           6       110            2       159
                  2338000     273000           15            9    C                9  AQUIA                 7         6             4         9           6       110            2       159
                  2247000     276500           20            7    P                8  PIEDMONT              4         3             4         9           5        50            1       122
                  2250500     276500           20            7    P                8  PIEDMONT              4         3             9         5           5        50            1       118
                  2254000     276500           20            7    P                8  PIEDMONT              4         3             9         5           5        50            1       ila
                  2257500     276500           35            5    P                8  PIEDMONT              4         3             9.        5           5        50            1       108
                  2261000     276500           20            7    P                8  PIEDMONT              4         3             9         5           5        50            1       118
                  2264500     276500           25            7    P                8  PIEDMONT              4         3             4         9           5        50            1       122
                  2268000     276500           30            7    P                8  PIEDMONT              4         3             4         9           5        50            1       122
                  2271500     276500           30            7    P                8  PIEDMONT              4         3             4         9           5        50            1       122
                  2275000     276500           25            7    P                8  PIEDMONT              4         3             9         5           5        50            1       118
                  2278500     276500           20            7    P                8  PIEDMONT              4         3             9         5           5        50            1       118
                  2282000     276500           25            7    P                8  PIEDMONT              4         3             9         5           5        50            1       118
                  2285500     276500           40            5    P                6  PIED14ONT             3         10         15           3           4        5D            1       104
                  2289000     276500           35            5    P                6  PIEDMONT              3         10         15           3           4        50            1       104
                  2292500     276500           30            7    P                8  PIEDMONT              4         3             9         5           5        56            1       118
                  2296000     276500           30            7    P                8  PIED14ONT             4         6             9         5           5        50            1       124
                  2299500     276500           30            7    C                9  POT014AC              a         6             9         5           7       400            4       159
                  2303000     276500           50            5    C                9  POTOMAC               8         6             9         5           7       400            4       149
                  2306500     276500           60            3    C                9  POTOMAC               8         6             9         5           7       400            4       139
                  2310000     276500           60            3    C                9  POTOMAC               8         6             9         5           7       400            4       139
          co      2313500     276500           45            5    C                9  POT014AC              8         6             9         5           7       400            4       149
                  2317000     276500           40            5    C                9  POT014AC              8         10         15           3           7       400            4       155
                  2320500     276500           40            5    C                9  POTOMAC               8         10         15           3           7       400            4       155
                  2324000     276500           70            3    C                9  POT014AC              8         10         15           3           7       400            4       145
                  2327500     276500           25            7    C                9  POTOMAC               8         6             9         5           7       400            4       159
                  2331000     276500           15            9    C                9  POTOMAC               8         6             1         10          7       400            4       174
                  2334500     276500           20            7    C                9  POTOMAC               8         6             1         10          7       400            4       164
                  2338000     276500           25            7    C                9  POTOMAC               8         6             1         10          7       400            4       164
                  2250500     280000           20            7    P                6  PIEDMONT              3         10         15           3           4        50            1       114
                  2254000     280000           20            7    P                8  PIEDMONT              4         3             9         5           5        50            1       118
                  2257500     280000           35            5    P                8  PIEDMONT              4         3             4         9           5        50            1       112
                  2261000     280000           25            7    P                8  PIEDMONT              4         3             4         9           5        so            1       122
                  2264500     280000           20            7    P                8  PIEDMONT              4         3             4         9           5        50            1       122
                  2268000     280000           30            7    P                8  PIEDMONT              4         3             4         9           5        50            1       122
                  2271500     280000           30            7    P                8  PIEDMONT              4         3             4         9           5        50            1       122
                  2275000     280000           25            7    P                8  PIEDMONT              4         3             9         5           5        50            1       118
                  2278500     280000           25            7    P                8  PIEDMONT              4         3             9         5           5        50            1       118
                  2282000     280000           30            7    P                6  PIEDMONT              3         10         15           3           4        50            1       1%
                  2285500     280000           30            7    P                6  PIEDMONT              3         10         15           3           4        50            1       114
                  2289000     280000           30            7    P                6  PIEDMONT              3         10         15           3           4        50            1       114
                  2292500     280000           25            7    P                8  PIEDMONT              4         3             9         5           5        50            1       118
                  2296000     280000           20            7    P                8  PIEDMONT              4         3             9         5           5        50            1       118
                  2299500     280000           30            7    P                6  PIEDMONT              3         10         15           3           4        50            1       114
                  2303000     280000           35            5    C                9  POTOMAC               8         6             9         5           7       400            4       149
                  2306500     280000           40            5    C                9  POTOMAC               8         6             9         5           7       400            4       149







                                                            REGIONAL                           A           S                     T         I                    C       DRASTIC
                VA GRID VA GRID                             AQUIFER RECHARGE
                  E-W        N-S       DEPTH                                                                        14EAW                 IMP.   HYDRAULIC
                                                            SYSTEM      RATING   AQU I F ER               SOIL      SLOPE               VADOSE CONDUCT.
                ---------------------------------------------------------------------------------------------------------------------------------------
                2310000    2BU000            45         5   C                9 POTOMAC            8           6          9         5          7      400           4       149
                2313500    280000            35         5   C                9 POTOMAC            8         10           15        3          7      400           4       Iss
                2317000    280000            35         5   c                9 POTOMAC            a           6          9         5          7      400           4       149
                23ZO500    280000            40         5   C                9 POTOMAC            8         10           15        3          7      400           4       155
                2324000    280000            60         3   C                9 POTOMAC            8         10           15        3          7      400           4       145
                2327500    280000            20         7   C                9 POTOMAC            8           6          4         9          7      400           4       163
                2331000    280000            20         7   C                9 POTOMAC            8           6          1       10           7      400           4       164
                2334500    280000            25         7   C                9 POTOMAC            a           6          1       10           7      400           4       164
                2338000    280000            25         7   C                9 POTOMAC            8           6          1       10           7      400           4       164
                2247000    283500            25         7   P                8 PIEDMONT           4           3          9         5          5        50          1       118
                2250500    283500            25         7   P                6 PIEDMONT           3         10           is        3          4        so          1       114
                2254000    283500            30         7   P                8 PIEDMONT           4           3          9         5          5        50          1       Ila
                2257500    283500            30         7   P                8 PIEDMONT           4           3          9         5          5        50          1       Ila
                2261000    283500            30         7   P                8 PIEDMONT           4           3          4         9          5        50          1       122
                2264500    283500            30         7   P                8 PIEDMONT           4           3          9         5          5        50          1       Ila
                2268000    283500            35         5   P                8 PIEDMONT           4           3          4         9          5        50          1       112
                2271500    283500            30         7   P                8 PIEDMONT           4           3          4         9          5        50          1       122
                2275000    283500            25         7   P                8 PIED14ONT          4           3          4         9          5        50          1       122
                2278500    283500            25         7   P                8 PIEDMONT           4           3          4         9          5        50          1       122
                2282000    283500            25         7   P                8 PIEDMONT           4           3          4         9          5        50          1       122
                2285500    283500            25         7   P                8 PIEDMONT           4           3          9         5          5        50          1       118
                2289000    283500            30         7   P                8 PIED14ONT          4           3          9         5          5        50          1       118
                2292500    283500            25         7   P                a PIEDMONT           4           3          9         5          5        50          1       118
                2296000    283500            25         7   P                6 PIEDMONT           3         10           15        3          4        50          1       114
                2299500    283500            35         5   P                8 PIEDMONT           4           3          9         5          5        50          1       108
                2303000    283500            40         5   P                8 PIEDMONT           4           3          9         5          5        50          1       108
                2306500    283500            40         5   C                9 POTOMAC            8           3          9         5          7      400           4       143
                2310000    283500            40         5   C                9 POTOMAC            8           6          9         5          7      400           4       149
                2313500    283500            20         7   C                9 POTOMAC            8         10           15        3          7      400           4       165
                2317000    283500            25         7   C                9 POTOMAC            8         10           15        3          7      400           4       165
                2320500    283500            30         7   c                9 POTOMAC            8           6          4         9          7      400           4       163
                2324000    283500            5         10   c                9 POTOMAC            8           6          9         5          7      400           4       174
                2327500    283500            15         9   C                9 POTOMAC            8         10           18        1          7      400           4       173
                2331000    283500            20         7   C                9 POTOMAC            8           6          9         5          7      400           4       159
                2334500    283500            20         7   C                9 POTOMAC            8           6          1       10           7      400           4       164
                2338000    283500            25         7   C                9 POTOMAC            8           6          1       10           7      400           4       164
                2250500    287000            30         7   P                8 PIEDMONT           4           3          9         5          5        50          1       118
                2254000    287000            30         7   P                8 PIEDMONT           4           3          9         5          5        50          1       118
                2257500    287000            25         7   P                8 PIEDMONT           4           3          9         5          5        50          1       Ila
                2261000    287000            25         7   P                8 PIEDMONT           4           3          4         9          5        50          1       122
                2264500    287000            20         7   P                8 PIEDMONT           4           3          9         5          5        50          1       118
                2268000    287000            25         7   P                8 PIEDMONT           4           3          4         9          5        50          1       122
                2271500    287000            30         7   P                8 PIEDMONT           4           3          4         9          5        50          1       122
                2275000    287000            30         7   P                8 PIEDMONT           4           3          4         9          5        50          1       122
                2278500    287000            25         7   P                8 PIEDMONT           4           3          4         9          5        50          1       122
                2282000    287000            25         7   P                8 PIEDMONT           4           3          4         9          5        50          1       122
                2285500    287000            25         7   P                8 PIEDMONT           4           3          4         9          5        50          1       122
                2289000    287000            25         7   P                8 PIEDMONT           4           3          4         9          5        50          1       122
                2292500    287000            20         7   P                8 PIEDMONT           4           3          9         5          5        50          1       118
                2296000    287000            15         9   P                8 PIEDMONT           4           3          9         5          5        50          1       128
                2299500    287000            25         7   P                8 PIEDMONT           4           3          9         5          5        50          1       Ila






                                                                  REGIONAL       R                      A             S                     T           I                              DRASTIC
                  VA GRID VA GRID                                 AQU I FER   RECHARGE                                         MEAN                    IMP.   HYDRAULIC
                     E-W         N-S        DEPTH                 SYSTEM      RATING AQUIFER                        SOIL       SLOPE                VADOSE CONDUCT.
                  ---------------------------------------------------------                  -----------------------------------------------------------------------------
                  2303000      287000           25            7   P                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2306500      287000           35            5   C                 9  POTOMAC              8         10         15            3           7       400            4       155
                  2310000      287000           40            5   C                 9  POTOMAC              8           3           9          5           7       400            4       143
                  2313500      287000           30            7   C                 9  POT014AC             8           6           4          9           7       400            4       163
                  2317000      287000           20            7   C                 9  POTOMAC              8           6           9          5           7       400            4       159
                  2320500      287000             5          10   C                 9  POTOMAC              8           6           4          9           7       400            4       178
                  2324000      287000           15            9   C                 9  POTOMAC              8         10         18            1           7       400            4       173
                  2327500      287000           20            7   C                 9  POTOMAC              8         10         18            1           7       400            4       163
                  2331000      287000           20            7   C                 9  POTOMAC              8         10         18            1           7       400            4       163
                  2334500      287000           15            9   C                 9  POT014AC             8         10         15            3           7       400            4       175
                  2247000      290500           35            5   P                 8  PIEDMONT             4           3           9          5           5        50            1       108
                  2250500      290500           35            5   P                 8  PIEDMONT             4           3           9          5           5        50            1       108
                  2254000      290500           30            7   p                 8  PIEDMONT             4           3           9          5           5        50            1       118
                  2257500      290500           20            7   P                 8  PIEDMONT             4           3           9
                               290500           20            7   P                 8  PIEDMONT             4           3           9          5           5        50            1       118
                  2261000                                                                                                                      5           5        50            1       118
                  2264500      290500           15            9   p                 8  PIEDMONT             4           3           4          9           s        50            1       132
                  2268000      290500           25            7   p                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2271500      290500           25            7   P                 8  PIEDMONT             4           3           9          5           5        50            1       118
                  2275000      290500           25            7   P                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2278500      290500           25            7   P                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2282000      290500           25            7   P                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2285500      290500           25            7   P                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2289000      290500           25            7   P                 8  PIEDMONT             4           3           9          5           5        50            1       118
                  2292500      290500           25            7   P                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2296000      290500           20            7   P                 8  PIEDMONT             4           3           9          5           5        so            1       118
                  2299500      290500           25            7   P                 8  PIEDMONT             4           3           9          5           5        50            1       118
          C3      2303000      290500           25            7   P                 8  PIEDMONT             4           3           9          5           5        50            1       118
                  2306500      290500           25            7   p                 6  PIEDMONT             3         10         15            3           4        50            1       114
                  2310000      290500           35            5   C                 9  POTOMAC              8         10         15            3           7       400            4       155
                  2313500      290500           35            5   C                 9  POTOMAC              8           6           9          5           7       400            4       149
                  2317000      290500           25            7   C                 9  POT014AC             8           6           9          5           7       400            4       159
                  2320500      290500             5         10    C                 9  POTOMAC              8           6           1         10           7       400            4       179
                  2324000      290500           20            7   C                 9  POT014AC             8         10         18            1           7       400            4       163
                  2327500      290500           35            5   C                 9  POT014AC             8         10         18            1           7       400            4       153
                  2331000      290500           20            7   C                 9  POTOMAC              8         10         18            1           7       400            4       163
                  2334500      290500           20            7   C                 9  POTOMAC              8           6           9          5           7       400            4       159
                  2338000      290500           20            7   C                 9  POTOMAC              8           6           4          9           7       400            4       163
                  2250500      294000           30            7   P                 8  PIEDMONT             4           3           9          5           5        50            1       118
                  2254000      294000           25            7   P                 8  PIEDMONT             4           3           9          5           5        50            1       118
                  2257500      294000           10            9   p                 8  PIEDMONT             4           3           9          5           5        50            1       128
                  2261000      294000           15            9   P                 8  PIEDMONT             4           3           9          5           5        50            1       128
                  2264500      294000           15            9   P                 8  PIEDMONT             4           3           4          9           5        so            1       132
                  2268000      294000           20            7   P                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2271500      294000           30            7   P                 8  PIED14ONT            4           3           4          9           5        50            1       122
                  2275000      294000           15            9   P                 8  PIEDMONT             4           3           4          9           5        50            1       132
                  2278500      294000           20            7   P                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2282000      294000           25            7   P                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2285500      294000           25            7   P                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2289000      294000           25            7   P                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2292500      294000           20            7   P                 8  PIEDMONT             4           3           4          9           5        50            1       122
                  2296000      294000           20            7   P                 8  PIED14ONT            4           3           4          9           5        50            1       122






                                                           REGIONAL                           A          S                   T                              C      DRAST I C
                VA GRID VA GRID                            AQUIFER RECHARGE                                       MEAN                IMP.' HYDRAULIC
                  E-W        N-S       DEPTH               SYSTE14   RAT I NG  AQU I FER                SOIL     SLOPE               VADOSE CONDUCT.
                ---------------------------------------------------------------------------------------------------------------------------------------
                2299500     294000         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2303000     294000         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2306500     294000         20          7   P               6 PIEDMONT            3       10         15          3         4        50          1       114
                2310000     294000         30          7   P               8 PIEDMONT            4         3          9         5         5        50          1       118
                2313500     294000         35          5   c               9 POTOMAC             8         3          9         5         7       400          4       143
                2317000     294000           5        10   C               9 POTOMAC             8         6          4         9         7       400          4       178
                2320500     294000         25          7   C               9 POTOMAC             a         6          9         5         7       400          4       159
                2324000     294000         20          7   C               9 POTOMAC             8       10         15          3         ;r      400          4       165
                2327500     294000         25          7   C               9 POTOMAC             8       10         18          1         7       400          4       163
                2331000     294000         20          7   C               9 POTOMAC             8       10         18          1         7       400          4       163
                2334500     294000         25          7   C               9 POTOMAC             a       10         15          3         7       400          4       165
                2338000     294000         25          7   c               9 POT014AC            8         6          4         9         7       400          4       163
                2254000     297500         30          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2257500     297500         20          7   P               8 PIED14ONT           4         3          9         5         5        50          1       Ila
                2261000     297500         20          7   P               8 PIEDMONT            4         3          9         5         5        50          1       118
                2264500     297500         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2268000     297500         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2271500     297500         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2275000     297500         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2278500     297500         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2282000     297500         25          7   P               8 PIEDMONT            4         3          4         9         5        so          1       122
                2285500     297500         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2289000     297500         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2292500     297500         20          7   P               8 PIEDMONT            4         3          9         5         5        50          1       118
                2296000     297500         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2299500     297500         30          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2303000     297500         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2306500     297500         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2310000     297500         25          7   P               8 PIEDMONT            4         3          9         5         5        50          1       118
                2313500     297500         35          5   c               9 POTOMAC             8         3          9         5         7       400          4       143
                2317000     297500           5        10   c               9 POTOMAC             8         6          1        10         7       400          4       179
                2320500     297500         35          5   c               9 POTOMAC             8         6          9         5         7       400          4       149
                2324000     297500         35          5   c               9 POTOMAC             8         6          9         5         7       400          4       149
                2327500     297500         15          9   C               9 POTOMAC             8       10         15          3         7       400          4       175
                2331000     297500         15          9   c               9 POT014AC            a       10         18          1         7       400          4       173
                2334500     297500         15          9   c               9 POTOMAC             8       10         18          1         7       400          4       173
                2338000     297500         20          7   c               9 POTOMAC             8       10         15          3         7       400          4       165
                2257500     301000         30          7   P               8 PIEDMONT            4         3          9         5         5        50          1       118
                2261000     301000         25          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2264500     301000         25          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2268000     301000         20          7   p               8 PIEDMONT            4         3          4         9         5        50          1       122
                2271500     301000         20          7   P               8 PIEDMONT            4         3          4         9         5        50          1       122
                2275000     301000         20          7   P               8 PIEDMONT            4         3          9         5         5        50          1       118
                2278500     301000         20          7   P               8 PIEDMONT            4         3          9         5         5        50          1       118
                2282000     301000         20          7   P               8 PIEDMONT            4         3          9         5         5        50          1       118
                2285500     301000         20          7   P               8 PIEDMONT            4         3          4         9         5        so          1       122
                2289000     301000         20          7   P               8 PIEDMONT            4         3          9         5         5        50          1       118
                2292500     301000         20          7   P               8 PIEDMONT            4         3          9         5         5        50          1       118
                2296000     301000         20          7   P               8 PIEDMONT            4         3          9         5         5        50          1       118
                2299500     301000         35          5   P               8 PIEDMONT            4         3          9         5         5        50          1       108
                2303000     301000         45          5   P               8 PIEDMONT            4         3          9         5         5        50          1       108







                                                           REGIONAL                          A         S                    T          I                    c       DRASTIC
                VA GRID VA GRID                            AQUIFER RECHARGE                                      MEAN
                    E-W      N-S        DEPTH                                                                                        IMP.    HYDRAULIC
                                                           SYSTEM     RATING    AQUIFER                SOIL      SLOPE              VADOSE CONDUCT.
                   -----------------    ------  ....................    --------------------     -------------         --------- -------------------------------------
               2J06500     301UOO         55          3 P                  8 PIEDMONT            4         3           9         5         5        50           1        98
               2310000     301000         60          3 P                  6 PIEDMONT            3        10           15        3         4        50           1        94
               2313500     301000         55          3 P                  8 PIEDMONT            4         3           9         5         5        50           1        98
               2317000     301000         50          5 c                  9 POTOMAC             8         3           9         5         7       400           4      143
               2320500     301000         35          5 C                  9 POTOMAC             a        10           15        3         7       400           4      155
               2324000     301000         45          5 C                  9 POTOMAC             8        10           15        3         7       400           4      155
               2327500     301000         45          5 C                  9 POTOMAC             8        10           15        3         7       400           4      155
               2331000     301000         15          9 C                  9 POTOMAC             8        10           15        3         7       400           4      175
               2334500     301000         15          9 C                  9 POTOMAC             8        10           18        1         7       400           4      173
               2261000     304500         25          7 P                  8 PIEDMONT            4         3           9         5         5        50           1      118
               2264500     304500         25          7 P                  8 PIEDMONT            4         3           9         5         5        50           1      Ila
               2268000     304500         25          7 P                  8 PIEDMONT            4         3           9         5         5        50           1      118
               2271500     304500         25          7 P                  8 PIEDMONT            4         3           4         9         5        50           1      122
               2275000     304500         25          7 P                  8 PIEDMONT            4         3           4         9         5        50           1      122
               2278500     304500         20          7 P                  8 PIEDMONT            4         3           4         9         5        so           1      122
               2282000     304500         20          7 P                  8 PIEDMONT            4         3           4         9         5        50           1      122
               2285500     304500         20          7 P                  8 PIEDMONT            4         3           4         9         5        50           1      122
               2320500     304500         30          7 c                  9 POTOMAC             8         6           9         5         7       400           4      159
               2324000     304500         30          7 C                  9 POTOMAC             8         6           9         5         7       400           4      159
               2264500     308000         20          7 P                  8 PIEDMONT            4         3           9         5         5        50           1      118
               2268000     308000         25          7 P                  8 PIEDMONT            4         3           9         5         5        50           1      118
               2271500     3080oo         20          7 P                  8 PIEDMONT            4         3           4         9         5        50           1      122
               2275000     308000         20          7 P                  8 PIEDMONT            4         3           4         9         5        50           1      122
               2320500     308000         25          7 C                  9 POT014AC            8        10           15        3         7       400           4      165
               2324000     308000         25          7 C                  9 POTOMAC             8        10           15        3         7       400           4      165
               2264500     311500         25          7 P                  8 PIEDMONT            4         3           4         9         5        50           1      122
               2268000     311500         25          7 P                  8 PIEDMONT            4         3           9         5         5        50           1      118
               2271500     311500         20          7 P                  8 PIEDMONT            4         3           4         9         5        50           1      122
               2320500     311500         25          7 C                  9 POTOMAC             8        10           15        3         7       400           4      165
               2324000     311500         25          7 C                  9 POTOMAC             8         6           4         9         7       400           4      163
               2268000     315000         25          7 P                  8 PIEDMONT            4         3           4         9         5        50           1      122




 I
 I
 I
 I
 I                     APPENDIX B'
 I         GEOGRAPHIC DISTRIBUTION OF DRASTIC
                    PARAMETER RATINGS
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 I
 1                          43
 1














                 2240000     2254000       2268000   228200D      2296000    2310000       2324000   2338000      2352000




                                                                                                                       -136000




            325500                                                                                                     Z25500




            -'15000                                                                                                      -
                                                                                                                         1@-000




            --04500                                                                                                    -C)4-500
                                              7                                         'A,
                                           7                                            5    I\A- 9 9.
                                           7  7 7
                                              7 7                 7                        T
            29401111                                                                                                   294-000
                                 7'                               7
                                        T  7  7 7            7 7
                                           7, 5                                                                        283500
                                                             7
                                                                                                   7
                                    5   7     7
                                        17    7          7     5  5  5  5
            -773000 --7                                                                                                27-5000
                                           7  7                                                       f-\ V I
                                 7  7   7  7  7
                                    7   7     7 7
            2-62500                     1                                                                  4           262500
                                        7                    7               13  5      15 15      s 1 31
                                           7, 7@7                    5     7    16      5  " i     5       1)
                                                                                 5      1011013     '1
                                  1\7   17                              L4@ -              I
            252000               1 \    i                                                                  -           252C,00
                                    7   7                                                  7 7
                                -1
                                                               7'
            241500                                       7,                7
                                                                                                                       241500




            131000   - - -
                                                                                                                       231000


                                                                                        5  7

            220500                                                                                                     2205,


                                                                                        FT                               0000
                 2240000      22-54000    2-268000    @-82000    2296000     2310000     2324000     2338000      2352000



                                                               Fiqure 1
                                                          Depth to Water
                                                              (D) Rating

                                                                   44















                2240000   2254000   2268000   2282000   2296000   2310000   2324000  2338000   2352000



           336000                                                                                   3360M




           325500                                                                                   325500


           315000 -                    m/                                                           315000


           304500 -                         S                                                       304500



           294000                                                                                   294000




           283500                                                                                   283500



           273000                                                           9                       27,3000



           262500                                                                                   262500
                                                                                          4,1



           252000                                                                                   252000




           241500                                                                                   241500




           231000                                                                                   231000




           220500                                                                                   220500




           210000                                                                                   210000
              2240000   2254000    Z268000   2282000   2296000   2310000   2324000   2338000   2352000


                                                      Figure 4
                                                    Net Recharge
                                                     (R) Rating

                                                         45












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            C1099zc                                                                                                                    CINGZ2




            0009C2    - - -                                                                                                            CID092c



                 O0CZ9CZ        COCIPM         000*Z@7    0QOD1i7       00096ZZ       OCCIZ827      00029ZZ      CIOCItSZZ     OODOtZZ
                                                                        C
                                                                                                                           -L







                                               Ead














                2240000   2254000    2268000   2282000    Z296000  2310000    2324000   2338000   2352000



           336000                                                                                      --136000




           325500                                                                                        25500
                                                     I

              15000                                                                                    3 15000




                                                                                                       704500
                                                                                                I  I



           294000                                                                                      994000
                                                                              110

           283500            5       5                    's          5       9                        283500
                                                                                   Kib do 1)
                                                          5                       @VlLl  3 1

                                          15
           273000                                                                                      273000
                                                          3



           262500                                                                                      262500


                             5       3         s
                                  3  3      5  S                    5 3    10)1                        252000
           252000
                               @z                                                        L

           241500                                                                                      241500
                                                              10



           231000                                                                                      231000
                                                                 0  s 9


           ?20500                                                          s                           220500
                                                                        1  101)    10



           2, 0000                                                       -                             210000
               2240000   21540111)  Z2611011C 221121101) 2296000   231011011 23240DO   23311000  2357-0011



                                                       Figure 7
                                                       Topography
                                                                 5

















                                                                                              I -L LJ






                                                      (T) Rating

                                                           48













                   1-240000    2254000     2268000    4-1282000    2296000   2,310000     2324000    2338000    2352000



              7-36000                                                                                                 336000
                                                                         21l

                                           7
              325500                                                                                                  325500




              315000                                                                                                  315000
                                               5                                        1 Yk-7
                                            5       5;                              1     iA                          304500
              -104500                   5,
                                i V 5   3   5  5 5  5               rl

              294000                                                                                                  294000


                                                                              7           '477    7  7
              233500                                   5'                           7   7 7                           283500
                                                                  5           7         7' 7@

                                                                                          41
              27,3000       "(5       5                                                      s
                                                                                             1                        273000
                                                                                          5, 6
              262500                                           5                             s           7 (1         262500

                                      i 4.  4  5 @5    5    5         7                      6    1           ix
                                               4 5                                           E5   S-i
              252000                                                                                                  252DOO
                                               4
                                     4 4                              7 7  7       6    i
                                                    5
              241500                                  5,                                                              241500

                                                                                                j
                                                                                        3-s'si3            I
              231000                                                                                                  231000




              220500                                                                                                  220500


              210000                                                                    1 -T r--@                     210000
                  2240000      2254000   2-268000    2282000     2296000    231C)OOD    2324000     2338DOO    2352000



                                                                Figure 9
                                                        Impact   of Vadose Zone
                                                                          g
                                                               (1) Rati   n
                                                                                          6-1 At



                                                                     49













                    2240000     2254000      2268000     2282000     2296000     2310000     2324000     2338000     2352000



               336000                                                                                                      335000



               325500                                                                                                      325500



               3115-000                                                                                                    315000



               -04500                                                                                                      304500
                                                                      i    A I "s-- 1      44,-/        4'
                                                                                              4  4
               294000         i V      i      i     i                                            4-     4'                 294000
                                                                                           4     4
                                                                                  4              4-

               283500                                                                                                      283,500


                                    i                                                                    Q..
               /73000                                                                                      @-\             273000
                                                    I  I        1        4        +           2



                                                                      4- 4  4-
               262500                                                                                                      262500


                                                                                                        2 -2     r@,       252000
               252000                                                                                             F34


               241500                                                                                                      241500



               231000                                                                                                      231000


               220500                                                                      2                               220500



               210000                                                                                                      210000
                    2240000     2254000     2268000     2282000      2296000     2310000     2324000     2338000     2352000



                                                                  Figure 9
                                                         Hydraulic Conductivity
                                                                 (C) Rating

                                                                       50
                                                                                                        2














                                                  2240000                           2254000                    2268000                       2282000                     2296000                      2310000                              2324000                    2338000                2352000



                                      336000                                                                                                                                                                                                                                                                336000




                                      325500                                                                                                                                                                                                                                                                325500




                                      315000                                                                                                                                                                                                                                                                315000
                                                                                                                                             I 4al
                                                                                                               IIAo                          111$ 112212
                                                                                                               118                           1aJ2 I Z2 12@2 112    2                                                                            a
                                      @04500                -                                                                                I                     '                                                                                                                                        304500
                                      -                                                       'yo              I li2 I i2                    in 112 118 1 8 1 S_L22 1@ 1 6 ll@ -8        68 116 /1)                   93 1 @/l             5@1 1' 15 1,13
                                                                                       !W1 IS                  118 122                       1122 122 1@ 122 1 2 t
                                                                                                                                                          _!2      1     f' a    1 1     112   1 -                                                       1,13         1'
                                      294000                                        I"d 118   ILI              12; 8132                      122 122 1 12 122 Iz2 112 122 1 2    122     in    112    14      IL8@ 1.2 1 a                 10ll@         1i3 1113     1., ly,     I      1                  294000
                                                                                                               I i I                                                                                                  I
                                                                          I I @841  IS lia    1 5              Iji8 Ii2                      112 1JB 122 1:2 1 21;2 1;8  12      d8      1 8   1 8    114     1$5 10 IN                    111,Ls        1Z143        IM
                                                                                              i                                              I                     i2
                                                                                    a  Ila    IS               I@ I i@'8                     142 1212 1 J@; 122 112 121211 8     Ila     1 8   in     1@1     1 13    153    1:'9          113 1,13      1@3 1113     1-5 @ I
                                      283500                              $)1       4  118    1 8              1212 1 1@8                    111 z122 122 122 112.L 8118 1 8     1 4     M     10     1L      10      1115   llis          163 I-p4      13lig        104@                                  283500
                                                                             )1     4  1      81 2             122 122                       122 122 1 aI'S 1 41 4 114   Ila     1 8     1J4   1 -9   114     149     115    14o           1! 15 1% 1    Q-44         144    4
                                                                          Ia @,     a  I      a10              1aI t2                        -1 ZZ 122 1 51 81 a104 134  Ila     1;4     IL),  1 Is   1.19    1 19    1L     1 Z           1! 15 1 -Z                   1 @4
                                                                                                                                                                                   6     1 Q   139    If9     Iz      135    1
                                      7_73000                             1         a  1      a1 5             118 1 18                      122 1 JS 1 @2 122 1 211@ 9@ -M                                                      '5        ILI 1 i9      1@ 111@1 1                                         273000
                                                                                                               I
                                                                          I@ I      a  I      is I B           Ila I li a                    1212 12211 B1@2 1 8104 1 JA         41 @ 5  1.9   1 .9   149     135     111    1   1         151 11.9      1Q1 - Q 1411 0\1 So I                         I
                                                                                                               11 ;                          ;                                                          I             i                                       \ I
                                                                          1111 1    4  1      41 8             12.2 J'8                      118 J8 1 12 1 81 41,14 4. Il4 90    1(4     156   116    1+5     1 @6    135    1   1         1+1 1 .1      1. a1@
                                                                                    1  1      41 9             122 Ila                       Ila 122 113 122 IS Ila 1 14 1 Is    173     1 .9  1S9    1. z    125     1@5    1             115 IJ5       in 1@ 9 t    g I         d
                                      262500                                                                                                                                                                                                                                                                262500
                                                                                                               1                             1ii2 .4 1 4  I@ 4     11'4  1 .9    1 ja    1 9   1 13   114     14.1    135    IM            1. 51.19      1, 11M V     , 1             151
                                                                                       1      81! U            I@a Ila                       J2I1 14 ii
                                                                                                               i                             i                                                                        i
                                                                                              1 8              114 1114                      116 1 i14 It4 1:4 124 t 411* Ile    I       v     1 z    11.1    165     li5    1 6           1:6 116       1z9 1.39 139   119    1 4 1
                                                                                                                                                                                                      91W     14.1    1 i9   I@ 5          IS2 157       1@6
                                                                                              \1               4104                          1;* l14 114 I@ A1@ 118 124  118     128     149   IS                                                        I. .9-L 9      111    1 Alai
                                      252000                                                                                                                                                                                                                                                                252000
                                                                                              114              114@@04                       112+ t4 114  118      1_@_' +       1 4     1+9   1 ig   141     1+1     151    I@ 1          14 IL         4@ @7, o SO
                                                                                    1         1 14 X@4                                       /14 104 1 @@5 1 4114 124 12, 8 1 e  1$-5    49    1! 19  1 L     115     115    1.5           1 45 1 18     1 IS V I     1@
                                      241500                                                                                                 1ix 114 124 1 W, 1 4  114 Ila       1, Is   1'. @q 1 i3  139     139     im     iss           1 .2 IL       1L8 I@ 1     129                                   24.1500
                                                                                                                                                                                 4-r, 0  vA    I g    139     1 L),   1 9    116           14 112        1, 1 A       1,
                                                                                                                                                                                               1! i3  13S     I i9    1 5    1 a           14 116        1 2J2        1@1
                                      231000                                                                                                                                             IW    1 .3   I@Q     1 ;9    119    1 5           IN 1-6        10 1 2                                             231000
                                                                                                                                                                   i                     1 @14        1 19    1 .9    135    1 9           1.5 156       421
                                                                                                                                                                                                        .9    1 .9    ik     1 9           1.9 46        144
                                      '220,500                                                                                                                                                        J@Q 1-0 11.0 1 59 1 @o 14,g                        1 +Ig I @g                                         220500
                                                                                                                                                                                                                      9 Ila 1              .0 1 9 2@0 1
                                                                                                                                                                                                                                                         9

                                      210000                              -                                                                                                                                                                                                                                 210000
                                               22400DO                       2254000                           Z268000                       2282000                  2296000                         2310000                    23240DO                      2338000                       2352000



                                                                                                                                                                   Figure 10
                                                                                                                                             Compo site DRASTIC Index Rating

                                                                                                                                                                                 51





























                                                                                                                DATE DUE

























                                                                                             GAYLORD No. 2333                                  PRINTED IN U.S.A.



























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