HomeMy WebLinkAboutAgenda - 05-05-1997 - 9c 1
ORANGECOUNTY
BOARD OF COMNIISSIONERS
ACTION AGENDA ITEM ABSTRACT
Meeting Date: May 5, 1997
Action Agenda
Item # Q_ (L
SUBJECT: Phase H of the Orange County ground water resources investigation
DEPARTMENT: County Manager PUBLIC HEARING: Yes No
ATTACHMENT(S): BUDGET AMENDMENT: Yes No
County Engineer's Memorandum INFORMATION CONTACT:
USGS' Draft Scope of Work County Engineer Extension 2303
TELEPHONE NUMBERS:
Hillsborough - 732-8181
Durham - 688-7331
Mebane - 227-2031
Chapel Hill - 967-9251/968-4501
PURPOSE: To present, for the BOCC's review, approval and commitment of funding, a draft
scope of work for the phase two portion of the water resources investigation.
BACKGROUND: In 1993, the Board of County Commissioners created the Orange County Water
Resource Committee(WRC). The committee was charged with assessing the status
of the County's ground water resource, in terms of quantity and quality, in general
conformance with the provisions of the County's adopted ground water resource
goal.
In accordance with its charge, the WRC worked with the US Geological
Survey to develop a proposal for a first step or initial phase of a ground water
investigation. This initial phase was intended to utilize an analysis of ground water
recharge to streams to provide a broad summary of baseline information on the
quantity of ground water in the different drainage basins and sub-basins of the County.
The investigation's approach to evaluating the resource on a drainage basin-by-basin
approach toward was intended to a provide better general understanding of ground
water availability. It was not intended to provide data that would allow for site-specific
estimates of ground water quantity. The proposal for the initial or phase one portion of
the ground water investigation was authorized by the BOCC on March 21, 1995. The
USGS report on this investigation, entitled"Ground Water Recharge to the Regolith-
Fractured Crystalline Rock Aquifer System, Orange County,NC", was formally
presented to the BOCC on December 2, 1996.
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During the fall of 1996, the Water Resource Committee began work developing a
proposed scope of work for a second phase ground water investigation that would
address the provisions of the BOCC's water resource goal in greater detail. The phase
two investigation was intended to accomplish two primary goals: 1)to refine the
ground water quantity information provided by the phase one study by evaluating the
distribution and range of ground water recharge rates within basins and sub-basins;
and 2)to characterize ground water quality throughout the County and to identify
areas that either presently suffer or are subject to ground water contamination. A
draft scope of work and an estimated budget of$200,000 to $250,000 for a phase
two ground water investigation were presented to the BOCC at its December 7,
1996 goal setting retreat.
As per the direction of the BOCC, the Water Resource Committee and staff have
worked with the USGS to refine a scope of work and budget for a phase two
ground water investigation. A final draft scope of work is attached for the Board's
review and approval. The budget for the proposed phase two study requires a
County contribution of approximately $80,000 per year for three consecutive fiscal
years beginning in FY 1997-98. The figures for County funding assume a USGS fifty
percent funding match or cost share for all three years. At present, USGS funding at
the fifty percent level is available for all three years of this project. However,
competition for matching USGS funds is currently very intense. The USGS will not
encumber its share of the project funding without a formal commitment to the
project by Orange County. If the County wishes for the USGS to produce the phase
two ground water study while providing fifty percent of the funding, the BOCC must,
at this time, formally commit the County to this project and to providing its share of
the project funding. If the County cannot commit to the project until a later date this
year, it is possible or even probable that USGS funds available for this project could
be drastically reduced. Unless there is a formal County commitment to the project at
this time, there is no assurance that the USGS will be able to participate in this type of
project or provide any funding at all in future years.
RECOMMENDATION: As the elements of the proposed phase two water resources investigation have
been designed specifically to address the provisions of the BOCC's water
resource goal, the Manager recommends that the Board: 1) approve the
proposed scope of work; 2) commit the funding necessary to pay the County
share of the project; and 3) direct staff to provide a letter outlining the Board's
actions in this matter and making the necessary assurances to USGS as to
the County's formal agreement to participate in the phase two study.
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MEMORANDUM
TO: County Commissioners
John Link, County Manager
COPIES: Don Cox, Chair-Water Resouces Committee
Marvin Collins, Planning Director
Sally Kost, Budget Director
David Stancil, Planner II
FROM: Paul Thames, PE, County Engineer
DATE: May 1, 1997
SUBJECT: Formal approval of County participation in and scope of work for proposed Phase II
Ground Water Resources Investigation
Please find attached the latest revision to the draft scope of work for the proposed Phase II Ground
Water Resources Investigation(GWRI). This scope of work has been developed by local USGS staff(in
coordination with County staff and the Water Resources Committee). This draft has been also been
submitted to the regional USGS office for preliminary approval as a part USGS' process to secure and
encumber federal matching funding for the project.
I have been recently informed by Dr. Charles Daniel of the USGS, member of the County's Water
Resources Committee and probable USGS project manager for the Phase II GWRI, that encumbering the
funds for the USGS fifty percent cost share will require a formal notice of intent to participate on the part
of Orange County. Apparently, competition for USGS funds is very intense. The only way to ensure that
fifty percent matching funds are available is for the BOCC to formally commit to the project as soon as
possible.
In terms of background related to the attached scope of work, you may recall that the Water Resources
Committee and County staff created and approved a draft scope of work for the Phase II ground water
investigation in late fall 1996. The WRC draft, along with an estimated $200,000 to $250,000 local share
budget, was forwarded for BOCC review and discussion at the December 1996 Goal Setting Retreat.
The attached USGS draft scope of work was developed as a reworking and fine-tuning of the WRC draft
document. An earlier USGS draft was reviewed by Water Resources Committee, committee staff and by
the Planning Director. The attached draft contains several revisions that attempt to respond to the
comments evoked by the earlier draft. Specifically, language has been added to Item 6 on page 9 to
provide for meetings between USGS and County staff to discuss study findings (data) and to determine
the potential implications of these findings on existing and potential County planning strategies and
policies. The"Reports" section on page 10 has been revised to include periodic status reports to the
Water Resources Committee and an interim oral report to the BOCC ("oral" is emphasized to indicate
that USGS' elaborate publishing process will not be involved in the interim report).
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Other differences between the WRC proposed scope of work and that proposed in this USGS draft scope
are found in Item 4 on page 7 and in the last sentence of Item 5 on page 9. Specifically, Item 4 has been
revised to set up a process by which County staff will be able to evaluate well-head capture areas for
public water supply wells (community wells) and maintain and update the data base(s) related to these
wells. The initial proposal involved USGS evaluating and creating a database for all existing community
water supply wells but had no component for updating database(s) or for training of County staff to
maintain or update the databases. The revision stated in Item 5 involves establishing guidelines for a
monitoring well program. The initial WRC scope of work actually provided for a network of ten
monitoring wells to be provided. Both the Item 4 and Item 5 modifications are for the purposes of
reducing project costs (approximately $15,000 County costs).
If the County is to commit itself to an obligation of approximately$80,000 per year for three years to
participate in a project with the USGS, there are several important things which should be noted. The
most important factor to keep in mind is that USGS is not a"consultant"; it undertakes projects more in
the role of partner. Unlike a consultant, the USGS has a vested scientific and financial interest in the data
and outcome produced by any project it undertakes. Thus one major advantage to USGS participation is
that USGS' precision and independence combine to produce a study in which results and findings are of
high quality and therefore cannot be easily assailed on the basis of bias or bad science. If there is a
disadvantage to participating in a project with USGS (as compared to a hired consultant), it is that
USGS' vested interest in the project makes USGS, its investigative/analytical processes and procedures
and the project itself more difficult to redirect or guide. The USGS study process is generally more
expensive, in the sense of total costs rather than local share cost, than a consultant generated project.
The additional expense results from USGS' exacting process for obtaining uncontaminated field data,
providing data analysis of high order precision and USGS's exhaustive internal peer review process.
One other important factor in undertaking a project with USGS rather than a consultant is that, once the
County signs a contract with USGS, it is committing itself to funding the project for all three years.
If the County wishes to cut costs for this project, the cleanest cut involves the elimination of the water
quality element. It is possible and even probable that this portion of the project could be accomplished
more cheaply by a consultant. It could certainly be accomplished at a later date. The total cost of the
water quality element of the proposed study is approximately$50,000 with a County savings of
approximately $25,000. However, I believe that eliminating the water quality portion of this project
would be a mistake. While ground water quality does not appear to be a serious or widespread problem
in Orange County, it is a major component of the BOCC's ground water goal. Water quality is certainly
a high profile issue that can be expected to generate public concern and interest, perhaps more so than
ground water quantity. I do not believe that the savings are sufficient to justify the elimination of the
ground water quality portion of the project.
If I may provide additional information, please advise.
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T=: NVESTIGATION OF GROUND-WATER AVAI1LAB11JTY
AND QUALITY IN ORANGE COUNTY,N.C.
INTRODUCTION:
Studies of Orange County's ground-water resources are needed to overcome a significant
deficiency in information related to the resource. The County proposes to employ information
about the quantity,quality and location of ground-water resources provided by these studies to
develop a database which will be utilized to evaluate ground-water quality and quantity and
potential threats to the resource. This information,in turn.will enable the County to develop
policies to protect and manage the source of water which currently supplies approximately 40
percent of the County's population. This information will become even more important as the
county's rural population increases and surface-water resources are fully allocated.
A pilot study was conducted by the U.S.Geological Survey(USGS)during 1995-1996. The
pilot study,"Ground-Water Recharge to the Regolith-Fractured Crystalline Rock Aquifer
System,Orange County,N.C.,"determined recharge rates in twelve drainage basins and
subbasins of the County(fig. 1). The proposed"Investigation of Ground Water Availability and
Quality"will build on information provided by the 1995-19%USGS study.
Data on ground-water availability,use,and water quality that is to be gathered in the
proposed study will supplement the information provided by the USGS recharge study,enabling
the County to learn mote about the area's carrying capacity or"the amount of ground water that
can be removed from the ground-water system without exceeding recharge or depleting long-
term storage." The study will also identify potential water-quality problems,both natural and
anthropogenic,that may restrict utilization of ground water for potable supplies.
PROBLEM:
Water supplies for rural residents in Orange County,like most counties in North Carolina,are
provided primarily by wells. There has recently been public concern about contaminated ground
water and availability of water supplies in Orange County. Although there have been a few
studies that have investigated ground water in Orange County over the last 50 years,these studies
are,in most cam,regional studies that include Orange County as part of large,multi-tarty
study areas and study results tend to be general in nature. Development in rural areas of the
County will require reliable water supplies and,to plan for this development.comprehensive,
detailed studies of ground-water resources in the County are needed. In addition,there currently
is no baseline ground-water quality data base that can be used to reliably evaluate ground water
quality. Thus,utilization of ground water to meet expected future increases in demand for water
supplies will require better knowledge of(1)ground-water availability,and(2)ground-water
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Figure 1.Regional setting of the Orange County study area in the Piedmont physiographic province of
North Carolina,selected drainage basins, and locations of gaging stations used in the ground-water
recharge analysis.
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Ground-water Availability
The number of people that can be supported by ground-water supplies in the County is
limited by the availability of ground water. Ground water is available in Orange County from
wells tapping the iegolith bedrock aquifer system that is present throughout the Piedmont.
Although previous investigations have addressed well yields and general hydrogeologic
characteristics,there has been no assessment that can be easily used by planners and water
managers to evaluate water-supply availability or to identify favorable areas for ground-water
supply development.
A recently completed study by the U.S.Geological Survey determined rates of recharge to the
ground-water system in 12 drainage basins and subbasins in the county. The recharge rates
represent the upper limit of long-term ground-water availability and can be used for planning on
a regional scale;however,these recharge rates are the average for an entire basin or subbasin,and
little is known about the distribution and range of recharge rates within a basin or subbasin. For
water-supply development,especially for large supplies such as community systems or
commerciailmdustrial systems,more detailed information is needed about the distribution of well
yields,saturated thickness of regolith,variability of recharge rates,current ground-water use,and
possible sauces of contamination within these basins and subbasins. Few well records,or other
information related to ground-water availability and current use,are available in computerized
files.
Ground-water Quality
There is a need to characterize ground-water quality,identify general areas of ground-water
contannnati�,including areas vulnerable to contamination,and to design a data base that the
County can use to manage ground-water resources and ground-water quality in Orange County.
Most available water-quality data consist of information derived from tap samples which were
not collected in a uniform manner and cannot be used to characterize ambient ground-water
quality. Many of the well records have been stored in files by address and street or road name.
As a result,ground-water quality cannot easily be related to hydrogeologic units or geographic
areas. Data on many constituents and properties have not been entered into a computerized data
base. Most chemical data are available only from paper file copies.
Preliminary results from an ongoing study in nearby Guilford County indicate radon levels in
ground water from some hydrogeologic units are as much as 20 times higher than the EPA
proposed level of 300 pCi/L(picocuries per liter). Similar hydrogeologic units occur in Orange
County and tests for radon appear warrented.
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OBJECTIVES:
The following list of objectives describes the information about ground-water resources that
Orange County requires in order to formulate policies for managing the resource. The study is
designed to attain the following goals and objectives regarding(1)ground-water availability,and
(2)groundwater quality so that the County can develop(3)planning and management strategies
for the use and protection of the resource:
Ground Water Availability
1. Evaluate the distribution of well yields in Orange County,based on an inventory of existing
wells,in relation to hydrogeologic units,fracture zones,and construction characteristics,
2. Estimate the total amount of ground water available for use in Orange County from ground
water in storage and recharge,
3. Estimate the amount of ground water currently being used in Orange County,and evaluate
effects of current and projected future demand on availability of ground water.
4. Delineate wellhead capture areas for several(3 or 4)high-yield wells in the County,and
document delineation procedures so they can be used as examples for training cocmty staff.
Ground Water Quality
S. Characterize the chemical quality of the County's ground water and its relative suitability for
development as a water source.
Planning and Manage==Strategies
6. Identify alternative planning and management strategies regarding general land-use patterns,
ground-water use,and ground water protection.
SCOPE:
The area of investigation will include Orange County,North Carolina and areas in adjacent
counties extending to hydrologic or hydrogeologic boundaries. The study will span 36 months
following the beginning date established in a joint funding agreement. It is proposed that the
study be carried out during the period from July 1, 1997 through June 30,2000.
The nature and characteristics of aquifers,hydrogeologic units,soil types,topographic
divides,and other hydrogeologic features,are not constrained by political boundaries such as
county lines. likewise,factors affecting the quality and quantity of the ground-water resource
are not bounded by these political boundaries. Therefore,it is assumed that the investigation of
the resource will address those circumstances that occur outside Orange County but that affect,or
have the potential to aff xx,the resource within the County.
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APPROACH:
The project will have three major work tasks. The first two are designed to characterize
ground-water availability and ground-water quality in the county. Study results will be
summarized in a published report and electronic documents. The third task involves
participation in meetings at the conclusion of the study to present study results and to identify
potential uses of the results for planning and management purposes.
Task I—Ground-Water Availability
This component will involve compilation and analysis of available information on
hydrogeology,soils,topography,well construction,static water levels,well yields,water use,and
population. Information on wells will be compiled from Orange County,State and Federal
agencies.well drilling companies,and well owners to obtain a database of a size(number of
records)suitable for statistical analysis and mapping of the distribution of well yields,depth to
the water table,thickness of regolith,and other ground-water related characteristics across the
County. The characteristics of each major aquifedhydrogeologic unit will be described in
relation to properties such as well yield,specific yield,and lithologic composition.
1. Evaluate the distribution of well yields:
A major goal of the study will be to develop a data base of well records that have been field
checked and that is sufficiently large to perform statistical analyses with high significance. The
statistical analyses will be made to relate well data to hydrogeologic information and water-use
information for the purpose of projecting well yields,estimated future groundwater use,and
overall carrying capacities of various subsections of the study area. It is acknowledged that there
exists an inherent problem of biases that arise from the selection of various types of wells,well
data,well sites,and well construction techniques. The investigation,to the extent practicable,
will use techniques that compensate for these biases to produce an accurate picture of the
quantity of ground water present and available for consumption.
The most recent geologic and hydrogeologic unit maps available will be digitized and will
form the basis for describing bedrock geology and hydrogoology in the County. A well inventory
of about 400 water supply or observation wells will be conducted. These wells will be selected
to provide statistically representative samples of well characteristics within the major
hydrogeologic units in the County. Well characteristics of particular interest include yield,total
depth,casing depth,diameter,and static water level. The major hydrogeologic units consist of
metaigneous and metavolcenic rocks of various cormpositions and phyllite. Lesser areas are
underlain by argillite and sedimentary rocks of Triassic age. The locations of all inventoried
wells will be verified by site visits;latitudes and longitudes will be determined from topographic
maps or by a Global Positioning System(GPS)instrument. Well records will be compiled into
digital files that can be transferred to the County's computer system;this information will also be
entered into the U.S.Geological Survey's Ground water site Inventory(GWSl)database.
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An analysis of drainage patterns and landforms using a combination of topographic maps,
geologic maps,and site visits will be made to identify and map suspected fracture traces. Aerial
photographs,perhaps in combination with satellite imagery,will be analyzed for photo
lineaments that may indicate large-scale(regional)fracture systems. Any photo lineaments not
related to cultural features will be included on the fracture-trace map. Possible correlations
between well yields,the distribution of well yields,and fracture traces or lineaments will be
evaluated by mapping wells and interpreted fractures,and evaluating the spatial relation between
these features.
2. Estimate the total amount of ground water available:
Available ground water consists of two components,drainable storage and recharge. By
measuring the depth to the water table at sampling wells and accounting for aquifer
characteristics such as rock type,porosity,and specific yield,it is possible to estimate the total
amount of ground water in storage and the quantity available horn storage.
Long-team availability of ground water also depends on the rate of recharge to the aquifer,
which is determined by the type of rock forming the aquifer,amount of rainfall,soil type,land
use and vegetation,land surface slope,and depth to the water table. The USGS pilot study
(completed for the County in 1996)provides the recharge rates and areas for the major watershed
areas of Orange County. This information will be integrated into analysis of long-term
availability.
Using data on ground-water storage and recharge in the County,the safe yield—the amount of
water that can be withdrawn without causing long-term water-table decline--will be estimated for
major aquifers/hydrogeologic units. The evaluation is to contain sufficient detail that it will
enable the County to establish a base line for evaluating the effects of long-term seasonal
climatic patterns,changes in land use and impervious surface on ground-water levels and aquifer
storage,ground-water withdrawals,and other factors. For example,the program will be designed
to mount for variations in hydrogeologic units,topography,and soil characteristics.
3. Estimate ground-water use and possible effects of increased demand:
In order to ascertain the County's future water supply needs and to assess the long-term
ability of ground water to mace these needs,it is necessary to evaluate the projected growth in
demand for ground-water resources given various land use plans and the associated effects of
population distribution. This evaluation process is to be accomplished by using water supply
demand projections which are based on population projections from various sources for various
land use patterns in conjunction with past water demand data and estimates of per capita
consumption rates. The Orange County Planning staff will provide the necessary population
projections,including Orange County,adjacent county,and State figures. The project staff will
acquire and analyze available community water supply records,census-tract records,and will
also employ the USGS statewide water use report to develop rural water consumption rate
estimates. The County's future water supply needs and the availability of ground water will be
analyzed and graphed. Different growth scenarios will be evaluated by means of a planning
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model which will show and account for the effects of the relationships among and between
population densities,land use(impervious surface,ground cover,infiltration capacity)and
hydrogeologic conditions(soil types,topography,hydrogeologic units). Consideration shall be
given to the potential effects of modifications to the plumbing section of the North Carolina
Building Code.
Estimates of recharge rates for each aquifer will be compared with rates of -water use
estimated from representative wells or average ruai consumption rates and with estimated losses
associated with various waste-water treatment practices to determine whether each aquifer's
water table is--m theocratically should be—rising,falling or remaining constant. Information on
waste-water treatment systems,including onsite septic and offsite treatment plants,will be
compiled from local utilities and census data The project staff will set up its data reporting and
analysis format such that,on completion of the investigation,County staff can continue the
process of making orisons of water level records with current monitoring results to further
understand water quantity trends. The delineation of ground-water usWosses is to be
calculated on the finest resolution possible based on hydrogeologic boundaries.
The resulting data on ground-water availability and current use will be displayed on a map
and entered into a database compatible with the County's ESRI ARC-INFO Geographic
Infasmtion System(00). The resulting database will facilitate the future drafting of policy by
enabling the combination of these data with other information relevant to land use such as
psolected population,zoning distracts,and nature!areas.
4. Delineate wellhead capture areas for several high-yield wells:
The importance of wellhead capMM areas lies in their direct link to ground-water
consumption and implications for health. Knowing the approximate location and extent of these
areas is necessary to make land-use decisions that protect them from contamination.
To the extent possible,all public supply wells identified from State and County records will
be included in the well inventory. Wellhead capture areas will be estimated for several(3 or 4)
high-yield wells(dwsc yielding geaw than 25 gallons per mi )using techniques
rzconuMended by the N.C.Division of Water Quality,Ground-Water Section. These win be
available as examples for training sessions on capture area delineation to be included in
information transfer meetings.
Task II—Water Quality
This please will involve compilation of available information on the quality of the the
County's ground water with respect to natural and man-made constituents,known ground-watear
contamination sites,and locations and withdrawal rates of pound-water based public supplies.
In addition,new infomation will be obtained by sampling representative wells for selected
chemical constituents such as radon,nutrients,trace metals silica.and hardness. Tests for
possible contaminants such as bacteria,components and derivatives of motor and heating fux.ls,
and herbicide/pesticide residues may be indicated for some wells.
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S. Characterize the chemical quality of the County's ground water.
If ground water is to continue to serve as a major source of potable water for Orange County
residents,the quality of the water must be assured. In the Piedmont region of North Carolina,
water supply problems generally involve quantity rather than quality. However,the project team
will compile and map existing information of ground-water quality and pollution sources in the
County and will develop and assist with implemeatatioa of a local well testing program which
will enable the County to assemble the data necessary to formulate public information and land
use policies.
The expense involved in performing a detailed analysis of water quality dictates the necessity
to limit this part of the investigation. Rather than test for all of the pollutants that could be found
in ground water,tests will only be made for pollutants common to Orange County and in areas
characterized by rural development. Nitrogen compounds and bacteria common to human and
animal wastes are likely in an area characterized by agriculture and rural populations dependent
on septic tanks. Furthermore,the agricultural nature of the County indicates the possible
Presence of pesticidVIieftode residues. Screening tests will be conducted for the most likely
pesticide/herbicide components. Screening techniques that enable the testing for selected
constituents can provide general water-quality information and indicate possible problem areas
without requiring great expense. In addition,existing data on water quality can provide a
baseline level which can be compared to data generated by earlier or later water-quality tests to
show a change in water quality. The project staff will compare newly obtained water quality data
with data that will be obtained from various State and County agencies which are and have been
traditional collectors and repositories of water quality and pollution data.
The project staff will evaluate ground-water quality by collecting ground-water samples and
performing chemical analyses. Samples will be collected at well sites selected according to a
stratified sampling plan based on hydrogeologic units and the area of each unit in the county.
Well sites within each unit will be selected to provide uniform areal coverage. As in the case of
the ground-water quantity investigation,samples also may be drawn from wells in adjacent
counties.
About SO of the invootoded wells will be sampled to characterize the wafer quality of the
major hydrogeologic units in the County. All SO wells will be sampled for specific conductance,
pH,temperature,major ions,nutrients(including nitrate),and will be screwed for BTEX
(organic compounds associated with gasoline)and selected pesticides using immunossaay
methods(contingent on availability of pesticide-specific immunoassay kits). About 30 of these
50 wells will be sampled for radon and trace elements. All laboratory analytical results will be
compiled and stored in WATSTORE data bases.
Natural water quality,or those water-quality parameters not resulting from man-made
pollution,such as hardness and iron,corrosivity,manganese and silica concentrations,
determines the desirability of ground water as a source for human consumption. Radon can also
occur at undesirable levels in ground water,especially in areas underlain by fiesic igneous or
metamorphic rocks. Elevated levels of radon have recently been identified in nearby Guilford
County which is underlain by crystalline rocks similar to Orange County. Maps of selected
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chemical constituents will be prepared in order to graphically relate the occurrence of these
constituents and to identify which areas in the County are most suitable for -water use.
The data produced by the water-quality analyses,like that produced by the quantity analysis,
will refer to the entire County and be entered into a database and mapped The data and neap will
be compatible with the quantity map and the Orange County FSRI ARC-INFO GIS to allow the
combination of multiple characteristics of a given location. Sites that pose a particular threat of
ground-water contamination also will be indicated Guide lines for establishing an observation-
well monitoring program will be developed
Task III—Planning and Management Strategies
6. Identify alternative planning and management strategies:
One or more meetings may be held between project staff and County representatives to
discuss study results and how they could be used by the County for development of planning and
management strategies. It is anticipated that examples illustrating use of ground-water
availability,land use,well yield,water use,population growth,and other data for planning and
management of the resource will be developed. Training sessions on methods of wellhead
capture area delineation will be hold for County staff,if requested.
County staff have indicated that a desired outgrowth of this study will be an ongoing ground
water quality/water table/well yield monitoring program that can be operated by the County.
Project staff will assist in development of plans for a monitoring program to achieve these goals.
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REPORTS:
A USGS Water Resources Investigations Report(WRIR)will be prepared to summarize
findings about ground-water availability and groin-water quality. These will be supported by
map products in digital format that can be transferred to the County's ARCINFO-based
Geographic Information System. An oral status report,supported by maps,graphs,and
summaries of available data,will be presented to County staff and officials midway through the
study. Status reports also will be made to the County's Water Resources Committee when
requested-
The WRIR will present findings related to the distribution of well yields within the county,as
well as maps showing the relation of well yields to hydrogeologic units,hw=e traces,
lineaments,and other geologic features that affect the distribution of well yield and grand-water
availability. Other findings to be presented in this resort include ground-water use,locations of
high-yield public-supply wells.and estimated losses associated with various wastewater
treatment practices.
The WRIR also will present findings related to ground-water quality and identified areas of
ground-water boa. Water quality data will be statistically summarized. Maps showing
water types and characteristics,known contamination sites.and potential contamination sites,
also will be included. Water-quality data fmm samples collated as part of this study will be
published in the U.S.Geological Survey's Annual Water-Resources Data Report.
Additional products of the study will include maps and data bases in digital format that will
be compatible with,and can be transferred to,the County's ARCIWO-based GIS(Geographic
Information System). A GIS version of the watershed map in the USGS Phase I study will be
prepared showing basins and sub-basins to which recharge estimates apply. The electronic data
bases will include non-map products such as well inventories.iechargc duration tables and
hydrographs of monthly recharge estimates.
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BENEFITS:
Information supplied by this study and contained within the final report products(a Water
Resources Investigations Report plus GIS coverages of map products)will be useful for purposes
of county-wide planning for future population growth and development. It will also be useful as
a guide for the management and protection of ground-water resources in Orange County. Water-
supply planting at the county level is becoming increasingly important as rapid growth continues
in rural areas of the Piedmont of the Southeast. Other benefits include protection of &nddng-
watea supplies,development of techniques and methods for ground-water supply development
and management in a complex hydrogeologic environment, and development of computerized
databases. Specific benefits for Orange County and the USGS include the following:
Orange County--
1. Production of map(s)of potential ground-water resource availability.
2. Production of baseline water quality data base for comparision with future analyses,
3. Screen selected county wells for BTEX and pestiod0therbicide contamination,
4. Identify area of potential groundwater contamination,
5. Satisfy State requirement for Well Head Protection Act delineation of capture areas.and
6. Development of plans for an observation well network for water level and water quality
monitoring.
7. Combine all of the above for
a) County-wide planning,and
b) management and protection of ground-water resources.
USGS--
1. Ground-water resource evaluation methodology transferrable to rest of Piedmont in North
Carolina and Southeast,
2. Protection of the Nation's drinidng--water supplies,
3. Increase ground water and water quality data bases,and
4. Continue development of approaches for resource evaluation that combine hydrologic
research with GIS methods.
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TIlME FRAME:
Following approval and funding,the study will be conducted over a 36-month period. For
budgetary considerations,it is proposed that the work be conducted during the period from July
1, 1997 through June 30,2000. Work tasks will proceed as follows:
Month 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36
Task
1. Literature and data
base searches
2. Conduct well
inventory
3. Compile and
analyze hydrologic
data
4. Prepare base maps -
5. Graphical output of results
Of I drogoologic analyses
in figures,tables,and maps
6. Compile available
ground-water quality data
7. Collect water samples for
new analyses
8. Identify and inventory potential
sauces of grand-water
contamination
9. Graphical output of results
of water-quality analyses
and site inventories
10.Preparation of WRRI
report manuscript
11.Review and approval
process
12.Preparation and
parroting of WRRI report
13.Finalize GIS coverages
of map products
14.Transfer GIS coverages to
Orange County computer system
15. Hold meetings with Canty staff
to assist with development of
planning and management strategies ----
16. Conduct training sessions on wellhead
capture area delineation,if requested
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PERSONNEL:
Analysis of data and production of the final report will be performed by personnel of the U.S.
Geological Survey,North Carolina District,Raleigh,North Carolina:
Hydrologic Studies Unit
Hydrologist GS 12/13(Project Chief) 75% time(for first 24 months)
70% time(for last 12 months)
Hydrologist GS 11/12(data analyst,GIS) 25% time(for 1g months)
Hydrologic technician GS 516!7 50% time(for 24 months)
Publications Unit
Draftsman 50% time(for 5 months)
Editor 25% time(for 5 months)
Typist 25% time(for 5 months)
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18 '
BUDGET:
Category Year 1 Year 2 Year 3
(7197-&98) (7/98-6/99) (7/99-62000)
Personnel $132,350 146,060 132,670
Supplies $ 2,160 720 720
Travel $ 980 3,890 980
Vehicles $ 2,260 4,550 2,260
Chemical analyses
Major ions $ 12,220
Radon $ 1,870
Trace elements $ 4,030
Nutrients $ 3,890
BTEX screening $ 450
FIerbicide4x*dcide screening $ 3,060
Immunoassay kits and standards $ 8,9%
Handling and shipping to lab $ 540
Report preparation $ 9,730
Printing $ 3,M
Reproduction $ 630 630 630
Total $147,370 $181,910 $150,230
FUNDING:
Year 1 Year 2 Year 3
(7/'97-6198) (7/98-6/99) (7/99-&=)
Orange County $ 73,685 $ 90,955 $ 75,115
U.S.Geological Survey $ 73,685 $ 90,955 $ 75,115
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