United States
Environmental Protection
Agency
Office of Research and
Development
Office of Water
Washington, DC 20460
EPA/625/R-93/002
February 1993
vvEPA Seminar Publication
Wellhead Protection:
A Guide for Small Communities
* I, *,£•»•«
^^ ^*w
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DISCLAIMER
This document has been reviewed by the U.S. Environmental Protection Agency and
approved for publication. Mention of trade names or commercial products does not con-
stitute endorsement or recommendation of their use.
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EPA/625/R-93/002
February 1993
SEMINAR PUBLICATION
WELLHEAD PROTECTION:
A GUIDE FOR SMALL COMMUNITIES
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
OFFICE OF SCIENCE, PLANNING AND REGULATORY EVALUATION
CENTER FOR ENVIRONMENTAL RESEARCH INFORMATION
CINCINNATI, OH 45268
OFFICE OF WATER
OFFICE OF GROUND WATER AND DRINKING WATER
GROUND WATER PROTECTION DIVISION
WASHINGTON, DC 20460
Recycled/Recyclable
Printed on paper that contains
at least 50% recycled fiber
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ACKNOWLEDGEMENTS
Many people contributed their expertise to the preparation and review of this publication. The
document was prepared by Eastern Research Group, Inc. Overall technical guidance was provided
by Tom Belk, U.S. EPA Ground Water Protection Division; Dr. James E. Smith, Jr., U.S. EPA
Center for Environmental Research Information; and John Trax, U.S. EPA Ground Water Protection
Division. The following people also provided substantial guidance and review:
Randy Anderson, National Rural Water Association
Marilyn Ginsberg, U.S. EPA Ground Water Protection Division
Janette Hansen, U.S. EPA Ground Water Protection Division
•J" v
Scott Horsley, Horsley and Witten, Inc.
Chuck Jeffs, Rural Water Association of Utah
Jill Jonas, Wisconsin Rural Water Association
John Lukin, Northeast Rural Water Association
Jane Marshall, U.S. EPA Ground Water Protection Division
Appreciation is also expressed to the following individuals for their assistance and input:
John Bokor, Idaho Rural Water Association
Maggie Clover, Iowa Rural Water Association
Chet Fleming, West Virginia Rural Water Association
Danny Foreman, Arkansas Rural Water Association
Ray Fuss, Georgia Rural Water Association
Richard Kunde, Michigan Rural Water Association
Judy Muehl, Pennsylvania Rural Water Association
Tom Taylor, Louisiana Rural Water Association
Clem Wethington, Kentucky Rural Water Association
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CONTENTS
Chapter 1 Introduction 1
Chapter 2 Ground Water Fundamentals 5
The Hydrologic Cycle 5
Aquifers 5
Confined and Unconfined Aquifers 5
Fractured and Carbonate Rock Aquifers 6
Recharge of Aquifers 6
Ground Water Movement 7
Chapter 3 Ground Water Contamination 9
How Ground Water Becomes Contaminated 9
Sources of Ground Water Contamination 10
Natural Sources 10
Septic Systems 10
Disposal of Hazardous Materials 10
Chemical Storage and Spills 11
Landfills 14
Surface Impoundments 14
Sewers and Other Pipelines 14
Pesticide and Fertilizer Use . : 14
Improperly Constructed Wells 15
Highway Deicing 16
Mining Activities 17
Effects of Ground Water Contamination 17
Degradation or Destruction of the Water Supply 17
Costs of Cleaning Up Contaminated Ground Water 17
Costs of Alternative Water Supplies 17
Potential Health Problems 17
Regulations to Protect Ground Water 18
The Safe Drinking Water Act 18
The Resource Conservation and Recovery Act 19
State Programs and Regulations to Protect Ground Water 23
in
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Chapter 4 The Five-Step Process for Wellhead Protection 25
STEP ONE—Form a Community Planning Team 25
Developing Community Representation 25
Selecting the Team Leader 26
Defining the Goals and Objectives of the Project 26
Informing the Public 26
STEP TWO—Delineate the Wellhead Protection Area 26
Reasons for Delineating a Wellhead Protection Area 26
Sources of Information 26
Methods for Delineating a Wellhead Protection Area 37
Hiring a Consultant 47
STEP THREE—Identify and Locate Potential Sources of Contamination 48
Divide the Wellhead Protection Area into Different Land-Use Categories 48
Review Potential Sources of Contamination 48
Identify Activities within the Wellhead Protection Area That Are Potential Sources of Contamination . . 56
Plot the Potential Sources of Contamination on a Map 57
Evaluate the Degree of Threat Each Source Poses 57
STEP FOUR—Manage the Wellhead Protection Area 58
Non-regulatory Management Strategies 58
Regulatory Management Strategies 63
STEP FIVE—Plan for the Future 65
Review the Wellhead Protection Plan Yearly 65
Identify Future Problems and Develop Solutions 65
Develop a Contingency Plan for Alternate Water Supplies 65
Conclusion 66
Chapter 5 Case Studies 67
CASE STUDY ONE: Hill, New Hampshire, Water Works 67
Description of Hill , 67
Overview of Wellhead Protection Issues 67
Approach Used to Form a Community Planning Team 67
Approach Used to Delineate the Wellhead Protection Area 68
Approach Used to Identify and Locate Potential Sources of Contamination 68
Approach Used to Manage the Wellhead Protection Area 68
Approach Used to Plan for the Future 74
Conclusion 74
CASE STUDY TWO: Village of Cottage Grove, Wisconsin 75
Description of Cottage Grove 75
Overview of Wellhead Protection Issues 75
Approach Used to Form a Community Planning Team 75
Approach Used to Delineate the Wellhead Protection Area 75
Approach Used to Identify and Locate Potential Sources of Contamination 78
Approach Used to Manage the Wellhead Protection Area 78
Approach Used to Plan for the Future 87
Conclusion 87
iv
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CASE STUDY THREE: Enid, Oklahoma 88
Description of Enid 88
Approach Used to Form a Community Planning Team 88
Approach Used to Delineate the Wellhead Protection Area 88
Approach Used to Identify and Locate Potential Sources of Contamination 92
Approach Used to Manage the Wellhead Protection Area 92
Approach Used to Plan for the Future 95
Conclusion 95
CASE STUDY FOUR: Descanso Community Water District, San Diego County, California 96
Description of the Descanso Community Water District 96
Overview of Wellhead Protection Issues 97
Approach Used to Form a Community Planning Team 98
Approach Used to Delineate the Wellhead Protection Area 99
Approach Used to Identify and Locate Potential Sources of Contamination 101
Approach Used to Manage the Wellhead Protection Area 101
Approach Used to Plan for the Future 103
Conclusion 104
Chapter 6 Resources for Additional Information 105
1. Publications 105
Technical Guides to Ground Water Contamination and Wellhead Protection (including
STEP ONE—Forming a Community Planning Team) 105
STEP TWO—Delineating the Wellhead Protection Area 106
STEP THREE—Identifying Sources of Contamination 107
STEPS FOUR AND FIVE—Managing the Wellhead Protection Area and Planning for the Future . 107
2. Federal, State, and Local Agencies 109
U.S. Environmental Protection Agency 109
Other Federal Agencies 110
State Agencies 111
Other Organizations 114
Rural Water State Associations 115
3. Financing Wellhead Protection 117
Taxes 117
Fees 117
Private Expenditures 117
Intergovernmental Assistance 117
Publications on Financing Wellhead Protection 118
4. Computer Modeling 118
Appendix A Regional Distribution of Ground Water in the United States 121
Western Mountain Ranges 121
Alluvial Basins 121
Columbia Lava Plateau 122
Colorado Plateau and Wyoming Basin 122
High Plains 122
Nonglaciated Central Region 123
Glaciated Centra! Region 123
Piedmont and Blue Ridge 123
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Northeast and Superior Uplands 123
Atlantic and Gulf Coastal Plain 123
Southeast Coastal Plain 123
Alluvial Valleys 124
Hawaiian Islands 124
Alaska 124
Puerto Rico and the Virgin Islands 124
Appendix B Methods for Delineating Wellhead Protection Areas for Fractured Rock Aquifers 125
Vulnerability Mapping 125
Flow-System Mapping 125
Residence-Time Approach 128
Numerical Models 128
Wellhead Protection Area Delineation Methods for Fractured Rocks That Do Not
Behave as Porous Media 128
Appendix C Methods for Delineating Wellhead Protection Areas for Confined Aquifers 133
Wellhead Protection Area Delineation Methods for Confined Aquifers with
Negligible-Sloping Potentiometric Surfaces 133
Wellhead Protection Area Delineation Methods for Confined Aquifers with
Regional Sloping Potentiometric Surfaces 138
Appendix D Conversion of Units 139
Appendix E Definitions of Hydrogeologic Terms 141
References 143
VI
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FIGURES
Figure Page
1-1 Guide to this publication 2
1-2 The five steps to wellhead protection 2
2-1 The hydrologic cycle 5
2-2 Water levels in wells completed in unconfined and confined aquifers 6
2-3 A fractured rock aquifer 6
2-4 The zone of contribution, zone of influence, and cone of depression 7
3-1 Schematic drawing of a contaminant plume 9
3-2 Some potential sources of ground water contamination 12
3-3 States with EPA-approved wellhead protection programs as of February 1993 19
4-1 Portion of the U.S. Geological Survey topographic map, Lexington Quadrangle 29
4-2 Portion of a set of soils maps from a soil survey by the Soil Conservation Service,
U.S. Department of Agriculture and Cornell University Agricultural Experiment Station 30
4-3 Portion of the Flood Insurance Rate Map (FIRM) for the Town of Lexington, Massachusetts 32
4-4 Portion of a U.S. Geological Survey Hydrologic Investigations Atlas - 662 33
4-5 Water table map 33
4-6 Zoning map 34
4-7 Recreation and open space land use map 35
4-8 Utility map depicting existing drainage piping network 36
4-9 Utility map depicting existing sewer network 36
4-10 Wellhead protection area delineation using the arbitrary fixed radius method 39
4-11 Wellhead protection area delineation using the calculated fixed radius method 39
4-12 Wellhead protection area delineation using the simplified variable shapes method 41
4-13 WHPA delineation using the uniform flow analytical model 42
4-14 WHPA delineation using hydrogeologic mapping (use of ground water divides) 46
4-15 Inventory of potential contaminant sources for a wellhead protection area 55
5-1 Calculations for delineation of the Hill wellhead protection area 69
5-2 Worksheet on delineation of the Hill wellhead protection area 70
5-3 Delineated wellhead protection area on topographic base 72
5-4 Wellhead protection area transferred to village tax map 73
5-5 Zoning map of Cottage Grove with well locations 76
5-6 Delineation of Cottage Grove wellhead protection areas using uniform flow equation 77
5-7 Delineation of Cottage Grove wellhead protection areas using WHPA Code computer program 79
5-8 List of potential contaminant sources for Cottage Grove 80
5-9 Village clerk's memo announcing proposed wellhead protection ordinance and public hearing 81
5-10 Cottage Grove wellhead protection resolution and ordinance 82
5-11 Aquifer and recharge areas for the Cleo Springs Wellfield 89
5-12 Map showing ground water flow and elevations in Enid's Cleo Springs Wellfield 90
5-13 Wellhead delineations for selected wells in Enid's Cleo Springs Wellfield 91
5-14 State survey used by Enid to identify potential sources of contamination 93
5-15 Locus map of the Descanso area, San Diego County, California 96
5-16 Descanso area, Upper Sweetwater River Basin, and location of streamflow measurement sites 97
5-17 Descanso water table map showing flow directions 99
5-18 Wellhead protection areas delineated for Descanso's drinking water 101
vii
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Figure Page
5-19 Descanso's land use/zoning map overlaid on the map of Descanso's wellhead protection area 102
5-20 Article appearing in the Alpine Sun, a Descanso local newspaper, on August 21, 1991 103
A-1 Ground water regions of the United States 121
A-2 Alluvial valleys ground water region .122
B-1 Shaded areas show wellhead protection areas based on vulnerability mapping for the
town of Sevastopol, Wisconsin 126
B-2 Portion of the water-table map of Junction City, Wisconsin 127
B-3 ZOC delineation in crystalline rocks using a field-measured water-table map 129
B-4 ZOC delineation in a deep ground water system in dolomite using a potentiometric-surface map. ... 130
B-5 ZOC delineation in a deep ground water system in dolomite using the uniform flow equation 131
B-6 ZOC predicted by numerical modeling for a well in crystalline rocks 132
C-1 Schematic of a semiconfined (leaky) aquifer. 133
C-2 Ground water flow toward pumping well with a negligible initial potentiometric-surface gradient 133
C-3 Ground water flow field for cone of depression of a pumping well with a regional ground
water flow gradient 134
C-4 Simulation of drawdown versus log distance for hypothetical aquifer for different values of
leakage using computer code PTIC 134
C-5 The lateral extent of a cone of depression of a pumping well can be determined with time versus
distance data 135
C-6 Simulation of time of travel (in years) for hypothetical aquifer for different values of leakage
using computer code PTIC 136
C-7 Example of reverse-path calculation using the WHPA computer program 137
VIII
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TABLES
Table Page
2-1 Porosity Values of Various Soils and Rocks .7
3-1 Typical Sources of Potential Ground Water Contamination by Land Use Category 11
3-2 Potentially Harmful Components of Common Household Products 13
3-3 National Estimates for Pesticides and Nitrates in Wells 16
3-4 Health Risks Associated with Contaminated Ground Water 18
3-5 Maximum Contaminant Levels (MCLs) for Drinking Water 20
4-1 Information Available from Existing Mapping 28
4-2 Costs Associated with Various Wellhead Protection Area Delineation Methods 37
4-3 Required Input for WHPA Model Computational Modules 44
4-4 Potential Sources of Ground Water Contamination 49
4-5 Land Uses and Their Relative Risk to Ground Water 57
4-6 Summary of Wellhead Protection Tools 59
5-1 Hydraulic Conductivity and Specific Yield Values for Soil Types in Enid's Cleo Springs Wellfield 88
5-2 Concentrations of Selected Constituents in 10 Samples from Wells in and near the Descanso
Area, 1988, and California Maximum Contaminant Levels (MCLs) for Domestic Drinking Water .... 98
5-3 Theis Equation Calculations for Descanso Valley 100
5-4 Results of Nitrogen Loading Analysis for Descanso Area 102
6-1 Examples of Funding for Wellhead Protection and Ground Water Protection 119
IX
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Chapter 1
Introduction
Ground water is a life-sustaining resource for small com-
munities throughout the United States. It supplies drinking
water for 95 percent of rural communities and about one-
half of the total U.S. population. It is also used for cooking,
for raising livestock, and for agricultural purposes.
Ground water was once thought to be protected from
contamination by layers of rock and soil that act as filters.
We now know, however, that ground water is vulnerable
to contamination. Contaminants can enter ground water
from landfills and lagoons used for storing waste, chemi-
cal spills, leaking underground storage tanks, and improp-
erly managed hazardous waste sites. Ground water
pollution also can result from a myriad of common prac-
tices, such as the use of fertilizers and pesticides; the
disposal of human, animal, and agricultural waste; and
the use of chemicals for highway de-icing. More than 200
different chemicals, some harmful to human health, have
been detected in ground water in the United States.
Preventing contamination is the key to keeping ground
water supplies safe. Once a drinking water supply be-
comes contaminated, a community is faced with the dif-
ficult and costly task of installing treatment facilities or
locating an alternative source. Wellhead protection—
managing a land area around a well to prevent ground
water contamination—offers an important opportunity to
both ensure a high-quality water supply and save money.
This document provides information that will help you
protect your community's ground water resources.
Ground water supplies drinking water for 95 percent of rural communities in the United States.
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Guidance for setting up wellhead protection programs is
available at the state and federal ie\/Pk hi it innai initiative
is the key to developing an effective program. Each com-
munity can best determine how to develop its own well-
head protection program by taking into account local
hydrogeological characteristics, land uses, and political
and economic conditions.
This publication is designed to help small community de-
cision makers, utility personnel, and other interested com-
munity members take intiative at the local level. It
provides the basic information needed to begin a well-
head protection program (Figure 1-1):
Chapter Two introduces some basic concepts about
ground water thaLarejusetuL in developing wellhead
Chapter Two
Ground Water
Fundamentals
Chapter Three
Ground Water
Contamination
Introduction to Concepts Used in Chapter Four
Chapter Four
The Five Steps to
Wellhead Protection
Chapter Five
Case Studies
Chapter Six
Resources for
Additional Information
Appendix A
Regional Distribution
of Ground Water in
the United States
Appendix B
Wellhead Protection
Delineation Guidance for
Fractured Rock Aquifers
Appendix C
Wellhead Protection
Delineation Guidance
for Confined Aquifers
Appendix D
Conversion of Limits
Appendix E
Glossary
protection programs. It discusses the hydrogeologic
cycle, types of aquifers, and fundamentals of ground
water movement.
• Chapter Three explains how ground water becomes
contaminated, discusses sources of ground water con-
tamination, and describes the potential effects on hu-
man health and local economies. It also discusses
legislation and regulations designed to protect ground
water supplies.
• Chapter Four, the core of the publication, presents the
five steps for developing a wellhead protection pro-
gram (Figure 1-2). These steps form a simple, struc-
tured approach that communities with little or no
experience in ground water protection or hydrogeologic
methods can implement with some assistance (for ex-
Step 1
Form a Community
Planning Team
Step 2
Define the Land Area
to Be Protected
Step3
Identify and Locate
Potential Contaminants
Step 4
Manage the Wellhead
Protection Area
StepS
Plan for the Future
Figure 1-1. Guide to this publication.
Figure 1-2. The five steps to wellhead protection.
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THE EPA/NRWA WELLHEAD PROTECTION PROGRAM
Much of the material in this publication is based on the
experience of a joint Environmental Protection Agency
(EPA)/National Rural Water Association (NRWA) program. In
March 1991, EPA's Office of Ground Water and Drinking
Water provided a grant to NRWA to help small communities
develop and implement wellhead protection programs.
Through the EPA/NRWA Wellhead Protection Program, small
communities gain access to a network of resources to help
them protect their drinking water supplies.
To implement the program, NRWA hired 12 ground
water technicians to work in 14 states: Arkansas, Georgia,
Idaho, Iowa, Kentucky, Louisiana, Michigan, Massachusetts,
New Hampshire, Pennsylvania, Utah, Vermont, West Vir-
ginia, and Wisconsin. The technicians were selected on the
basis of their experience with municipal water programs,
technical knowledge, communications skills, and willingness
to travel. They received intensive training on the program's
objectives, ground water pollution, wellhead protection, the
five-step approach to wellhead protection, outreach and edu-
cation strategies, and follow-up techniques. The technicians
travel to small communities throughout their states, convinc-
ing them of the importance of wellhead protection, providing
technical assistance, and taking them through the five steps
to wellhead protection. Communities are encouraged to take
the lead as they gain expertise in wellhead protection strate-
gies and techniques.
The EPA/NRWA Wellhead Protection Program has
made important strides in showing small communities the
need for wellhead protection and helping them set up local
programs. As of January 1993, 600 water systems had initi-
ated wellhead protection, resulting in protection of the drink-
ing water sources of more than 1 million people. It is unlikely
that any of these systems would have developed wellhead-
protection plans without assistance from the EPA/NRWA
program.
To further disseminate the knowledge gained through
this program, EPA's Office of Science, Planning and Regu-
latory Evaluation is coordinating a major technology transfer
effort, consisting of workshops, publications, and other com-
munications mechanisms. Workshops fn eight states (Cali-
fornia, Georgia, Iowa, New Jersey, Oklahoma, Pennsylvania,
Utah, and Wisconsin) began in Fall 1992. "State Center-
piece" workshops are bringing together individuals and or-
ganizations involved in wellhead protection to coordinate
efforts throughout each, state and explore ways to help local
communities develop wellhead protection plans. "Area-Wide"
workshops promote awareness of ground water and well-
head protection and provide information to small community
decisionmakers on how to set up local programs. This semi- -
nar publication is intended to bring information about well-
head protection to other small communities "across the
nation.
ample, from the state drinking water agency, the State
Rural Water Association, the regional agricultural ex-
tension office, and/or the EPA regional office). Chapter
Four includes an overview of methods for delineating
wellhead protection areas.
NOTE: The reader might wish to begin with Chapter Four
to learn about the steps involved in wellhead protection,
and refer to Chapters Two and Three as needed.
• Chapter Five presents case studies describing the ex-
periences of four small communities in setting up well-
head protection programs.
• Chapter Six lists many publications, financial assis-
tance programs, and regional resources available to
communities.
• Appendix A presents information on ground water re-
gions of the United States.
• Appendices B and C discuss wellhead protection area
delineation for confined aquifers and fractured rock.
• Appendix D provides information to help the reader
convert numbers in this document to metric units.
• Appendix E presents a glossary of terms used in this
publication.
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Chapter 2
Ground Water Fundamentals
People involved or interested in developing a wellhead
protection program should understand some basic scien-
tific concepts about ground water, such as the hydrologic
cycle, the different types of aquifers, and characteristics
of ground water movement. These concepts are intro-
duced briefly below. In-depth resource documents on
ground water can be consulted for additional information
(see Chapter Six). A municipality may choose to seek the
expertise of a professional hydrogeologist to obtain more
information about local ground water conditions and to
perform ground water tests.
The Hydrologic Cycle
The exchange of water between the earth and the atmos-
phere through such processes as evaporation and pre-
cipitation is known as the hydrologic cycle. When rain
or other precipitation reaches the land's surface, some of
the water renews surface waters such as rivers, lakes,
streams, and oceans; some is absorbed by plant roots;
and some evaporates. The rest of the water infiltrates the
ground to become ground water. Ground water moves
beneath the land surface, but most ground water even-
tually discharges into springs, streams, the sea, or other
surface waters. A portion of the surface water evaporates
into the atmosphere, eventually forming clouds and more
precipitation, thus completing the hydrologic cycle. Plants
also contribute to the hydrologic cycle through transpira-
tion, evaporation of moisture from the pores in plant
leaves. Figure 2-1 illustrates the hydrologic cycle.
Aquifers
Aquifers are composed of either consolidated or uncon-
solidated materials and yield useable quantities of water.
Unconsolidated deposits are composed of loose rock or
mineral particles of varying sizes; examples include clay,
silt, sand, gravel, and seashell fragments. Consolidated
deposits are rocks formed by mineral particles combining
from heat and pressure or chemical reactions. They in-
clude sedimentary (previously unconsolidated) rocks,
such as limestone, dolomite, shale, and sandstone, igne-
ous (formed from molten) rocks, such as granite and
basalt, and metamorphic rocks, such as quartzite and
gneiss. Some limestones and sandstones may be only
EVAPORATION
Figure 2-1. The hydrologic cycle.
partly cemented and are considered to be semiconsoli-
dated deposits. Aquifers can range in areas from several
acres to thousands of miles wide and from a few feet to
hundreds of feet thick.1 In the rural setting, aquifer mate-
rials in much smaller-sized deposits are the source of
water to private wells. Depending on their depth and size,
these deposits can be very susceptible to contamination.
Water collects in the fractures, intergranular pores, and
caverns in the rock. Water in the zone where all of the
pores, fractures, and caverns are saturated with water
(the saturated zone) is called ground water. The top of
the saturated zone is called the water table. The under-
ground zone above the water table contains both air and
water and is called the vadose or unsaturated zone.
Confined and Unconfined Aquifers
There are two general types of aquifers, unconfined and
confined. (Figure 2-2 shows an unconfined and a con-
fined aquifer.) The top of an unconfined aquifer is the
water table at atmospheric pressure. For this reason,
11nch-pound units are used in this publication to facilitate its use by the
intended audience. Appendix D contains a table for conversion to met-
ric units.
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WATER LEVEL IN THE WELL
-COMPLETED IN AN UNCONFINED
AQUIFIER
WATER LEVEL
IN THE TIGHTLY
CASED WELL —
COMPLETED IN
THE CONFINED
AQUIFIER
'. •' -'.-. .' ..'•, ICONFINED AQUIFER[ .'... " . :
Rgure 2-2. Water levels in wells completed in unconfined
and confined aquifers. Prepared by Horsley and Witten, Inc.
unconfined aquifers are also called water table aquifers.
Unconfined aquifers can be found anywhere from zero to
thousands of feet below the land surface.
The water table depth and the composition of unsaturated
zone materials above an unconfined aquifer are important
factors in determining how rapidly the aquifer can become
contaminated (U.S. EPA, 1987). Unconfined, shallow
aquifers found close to the land surface are easily acces-
sible, but are also easily contaminated. Conversely, deep
aquifers are often more difficult to obtain water from, but
may be less likely to become contaminated, depending
on hydrogeologic conditions.
Above the confined aquifer is a confining unit of imper-
meable (or very slowly permeable) material such as clay
or shale. It is difficult for water or other materials to flow
through this layer. Confined aquifers are often found at
greater depths than unconfined aquifers. Water in the
confined aquifer is at greater than atmospheric pressures;
for this reason, water in wells tapping confined aquifers
rises above the top of the aquifer. Confined aquifers are
also called artesian aquifers. Some wells in confined
aquifers have so much artesian water pressure that they
flow above the land surface without pumping.
The relatively impermeable materials overlying confined
aquifers protect them from contamination to varying de-
grees. Confined aquifers, however, can become contami-
nated through natural or anthropogenic openings (e.g.,
rock fractures or well casings) or from contaminated
ground water flowing into the aquifer from a distant loca-
tion. Confined aquifers can be characterized as either
semiconfined or highly confined. In semiconfined aqui-
fers, leakage of water and possibly contaminants occurs
through the confining layer above; in highly confined aqui-
fers, leakage is negligible (U.S. EPA, 1991 a). Thus,
semiconfined aquifers are more susceptible to contami-
nation from sources directly above than are highly con-
fined aquifers.
Fractured and Carbonate Rock Aquifers
Fractures in consolidated rock (bedrock) play an impor-
tant role in ground water movement. The structure of
many fractured rock aquifers (Figure 2-3) allows water
fractured^edfQck"«'s~'t ^
Figure 2-3. A fractured rock aquifer.
to flow through them in variable directions, making it dif-
ficult to predict and measure ground water flow (U.S.
EPA, 1987; U.S. EPA, 1991b). In general, the direction of
ground water flow through unconsolidated aquifers is less
variable. (Fractures can, however, be important in dense
unconsolidated materials, such as glacial tills and clay
layers.) Carbonate aquifers are composed of limestone
and other water-soluble rocks whose fractures have been
widened by physical erosion to form sinkholes, caves,
or tunnels (U.S. EPA, 1991b). Water and any accompa-
nying contaminants often move very rapidly in carbonate
aquifers.
Recharge of Aquifers
Replenishment of aquifers is known as recharge. Uncon-
fined aquifers are recharged primarily by precipitation per-
colating, or infiltrating, from the land's surface. Confined
aquifers are generally recharged where the aquifer ma-
terials are exposed at the land's surface (outcrop).
Surface waters also can provide ground water recharge
under certain conditions. Properly identifying the recharge
area is critical in ground water protection because the
introduction of contaminants within the recharge area can
cause aquifer contamination.
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Ground Water Movement
An aquifer's ability to receive, store, or transmit water or
contaminants depends on the characteristics of the aqui-
fer (including the confining layers associated with a con-
fined aquifer or the overlying unsaturated zone of an
unconfined aquifer).
Porosity refers to the amount of space between soil or
rock particles and reflects the ability of a material to store
water. Expressed quantitatively, it is the ratio between the
open spaces and the total rock or soil volume. Table 2-1
illustrates the porosity of various types of subsurface de-
posits. Soils are said to be porous when the percentage
of pore space they contain is large (such as a soil with
porosity of 55 percent).
Table 2-1. Porosity Values of Various Soils and Rocks
Material
Soil
Clay
Sand
Gravel
Limestone
Sandstone,
semiconsolidated
Granite
Basalt, young
Porosity
(%)
55
50
25
20
20
11
0.1
11
Specific
Yield1
(% by vol)
40
2
22
19
18
6
0.09
8
Specific
Retention2
(%)
15
48
3
1
2
5
0.01
3
1The amount of water yielded under the influence of gravity.
^e amount of water rocks or soils will retain against the pull of gravity
to the rock/soil volume.
Source: U.S. EPA, 1990a.
Hydraulic conductivity is a term that describes the ease
with which water can pass through subsurface deposits
(and thus transmit water to a well). Generally, the larger
the pores, the more permeable the material, and the more
easily water can pass through. Coarse, sandy soils are
quite porous and permeable, and thus ground water gen-
erally moves through them rapidly. Bedrock is often not
very porous but may contain large fractures through
which ground water passes quickly. Clay soils are quite
porous but not very permeable, and water moves through
clay very slowly.
Ground water generally moves quite slowly—from about
several feet per day to several feet per year—although it
can move much faster in very permeable soils or in cer-
tain geologic formations, such as cavernous limestone.
Gravity and pressure differences are also important fac-
tors in ground water movement. The direction and speed
that ground water and accompanying contaminants flow
are to a large degree determined by the hydraulic gra-
dient. The hydraulic gradient is the slope of a water table,
or in a confined aquifer, the slope of the potentiometric
surface (the surface defined by the elevation to which
water rises in wells that are open to the atmosphere). In
many cases, the hydraulic gradient parallels the slope of
the land surface. The velocity of ground water movement
also can be measured. Slope and velocity measurements
can provide time of travel estimates, which indicate the
amount of time it will take water or a contaminant to reach
a predetermined location (Pettyjohn, 1989).
Well pumping alters the natural movement of ground
water. When pumped, ground water around the well is
pulled down and into the well. The underground area
affected by the pumping is called the cone of depres-
sion; the same area as viewed on a map of the ground
surface is known as the area or zone of influence (see
Figure 2-4). The cone of depression may extend from a
few feet to many miles, depending on local hydrogeologi-
cal conditions. Generally, the cone of depression for an
VERTICAL PROFILE
Ground
Zone of Contribution ^ /Water
i/ Divide
Figure 2-4, The zone of contribution, zone of influence,
and cone of depression. Prepared by Horsley and Witten,
Inc.
-------
unconfined aquifer is smaller than for a confined aquifer pumping. Any contaminants located in the zone of con-
(U.S. EPA, 1990a). Cones of depression increase the tribution might be drawn into the well along with the water;
hydraulic gradient, and thus pumping can change the therefore, a wellhead protection area should encompass
direction and velocity of ground water flow (U.S. EPA, the zone of contribution if possible.
1990a; Pettyjohn, 1989). The zone of contribution (see
Figure 2-4) is the area of the aquifer that recharges the A selected list of terms frequently used in ground water
well. The zone of contribution also can be altered by hydrology is defined in the glossary (Appendix E).
-------
Chapter 3
Ground Water Contamination
Nearly all public water supplies in the United States pro-
vide water that is safe to drink. Incidents of ground water
contamination, however, have been reported in every
state. The following statistics demonstrate the need for
communities to protect their ground water supplies from
contamination (U.S. EPA, 1990a; U.S. EPA, 1990c):
• More than 200 chemical contaminants have been iden-
tified in ground water.
• Some 52,181 cases of illness associated with ground
water contamination (mostly short-term digestive dis-
orders) were reported between 1971 and 1985.
• Seventy-four pesticides have been detected in the
ground water of 38 states.
• Approximately 10 percent of public water supplies de-
rived from ground water exceed federal drinking water
standards for biological contamination.
This chapter discusses how ground water can become
contaminated, the sources of contamination, and the po-
tential effects on human health and local economies. It
also presents an overview of federal laws and examples
of state regulations designed to prevent ground water
contamination.
How Ground Water Becomes Contaminated
Depending on its physical, chemical, and biological prop-
erties, a contaminant may move within an aquifer in the
same ways that ground water moves. (Some contami-
nants, however, do not follow ground water flow). It is
possible to predict, to some degree, the transport within
an aquifer of those substances that move along with
ground water flow. For instance, both water and certain
contaminants flow from recharge areas to discharge ar-
eas. Soils that are porous and permeable tend to transmit
water and certain types of contaminants with relative ease
to an aquifer below.
Just as ground water generally moves slowly, so do con-
taminants in ground water. Because of this slow move-
ment, contaminants usually remain concentrated in the
form of a plume that often flows along the same path as
the ground water. The size and speed of the plume de-
pend on the amount and type of contaminant, its solubility
and density, and the velocity of the surrounding ground
water (U.S. EPA, 1990c). Figure 3-1 illustrates a contami-
nant plume.
Land Surface
SOURCE
i I I
Figure 3-1. Schematic drawing of a contaminant plume.
Prepared by Horsley and Witten, Inc.
Ground water and contaminants can move rapidly
through fractures in rocks. Fractured rock presents a
unique problem in locating and controlling contaminants
because the fractures are generally randomly spaced and
do not follow the contours of the land surface or the
hydraulic gradient.
In addition, there is growing concern about the contami-
nation of ground water through macropores. These are
root systems, animal burrows, and other systems of holes
and cracks that supply pathways for contaminants.
In areas surrounding pumping wells, the potential for con-
tamination increases because water from the zone of
contribution, a land area larger than the original recharge
area, is drawn into the well and the surrounding aquifer.
Some drinking water wells maintain an adequate water
yield through induced infiltration, whereby water from a
nearby stream, lake, or river contributes to the well dis-
charge. Contaminants present in the surface water can
degrade the water quality of the aquifer. Some wells rely
-------
on artificial recharge to increase the amount of water
infiltrating an aquifer, often using watpr from stomLcmanff^
irrigation, industrial processes, or treated sewage. In sev-
eral cases, this practice has resulted in increased con-
centrations of nitrates, metals, viruses, or synthetic
chemicals in the water (U.S. EPA, 1990a).
Under certain conditions, pumping can also cause the
ground water (and associated contaminants) from an-
other aquifer to enter the one being pumped. This phe-
nomenon is called interaquifer leakage. Thus, properly
identifying and protecting the areas affected by well
pumping is important to the maintenance of ground water
quality. Chapters Two and Four discuss pumping and
wellhead protection in more detail.
Generally, the greater the distance between a source of
contamination and a ground water source, the more likely
that natural processes will reduce the impacts of contami-
nation. Processes such as oxidation, biological decay
(which sometimes renders contaminants less toxic), and
adsorption (binding of materials to soil particles) may take
place in the soil layers of the unsaturated zone and re-
duce the concentration of a contaminant before it reaches
ground water (U.S. EPA, 1990a). Even contaminants that
reach ground water directly, without passing through the
unsaturated zone, can become less concentrated by di-
lution (mixing) with the ground water. Because ground
water usually moves slowly, however, contaminants often
undergo little dilution (U.S. EPA, 1990a; U.S. EPA,
1990c).
SOURCES OF GROUND WATER
CONTAMINATION
Ground water can become contaminated from natural
sources or numerous types of human activities. Residen-
tial, municipal, commercial, industrial, and agricultural ac-
tivities can all affect ground water quality. Contaminants
may reach ground water from activities on the land sur-
face, such as industrial waste storage or spills; from
sources below the land surface but above the water table,
such as septic systems; from structures beneath the
water table, such as wells; or from contaminated recharge
water. Table 3-1 and Figure 3-2 describe common
sources of potential ground water contamination; some
of these sources also are discussed below.
Natural Sources
Some substances found naturally in rocks or soils, such
as iron, manganese, chlorides, fluorides, sulfates, or ra-
dionuclides, can become dissolved in ground water. Other
naturally occurring substances, such as decaying organic
matter, can move in ground water as particles. Whether
any of these substances appear in ground water depends
on local conditions. Some of these substances may pose
a health threat if consumed in excessive quantities; others
may produce an undesirable odor, taste, or color. Ground
water containing these substances often is not used as
-a-sypp(y--fG^^Hnking^r-^ther-domestie-water-uses-ror is-
treated to remove these substances.
Septic Systems
One of the main causes of ground water contamination
in the United States is the effluent (outflow) from septic
tanks, cesspools, and privies (U.S. EPA, 1990a). Approxi-
mately one-quarter of all homes in the United States rely
on septic systems to dispose of their human wastes (U.S.
EPA, 1991c). Although each individual system releases a
relatively small amount of waste into the ground, the large
number and widespread use of these systems makes
them a serious contamination source. Septic systems that
are improperly sited, designed, constructed, or main-
tained can contaminate ground water with bacteria, vi-
ruses, nitrates, detergents, oils, and chemicals (U.S. EPA,
1990c). Commercially available septic system cleaners
containing synthetic organic chemicals (such as 1,1,1-
tricholoroethane or methylene chloride) have contami-
nated drinking water wells. These cleaners also interfere
with natural decomposition processes in septic systems
(Massachusetts Audubon Society, 1985a).
Some state and local regulations require specific separa-
tion distances between septic systems and drinking water
wells. In addition, computer models have been developed
to calculate suitable distances.
Disposal of Hazardous Materials
Hazardous waste should always be disposed of properly
(e.g., by a licensed hazardous waste handler or through
municipal hazardous waste collection days). Many chemi-
cals should not be disposed of in household septic sys-
tems, including oils (e.g., cooking, motor), lawn and
garden chemicals, paints and paint thinners, disinfec-
tants, medicines, photographic chemicals, and swimming
pool chemicals. Table 3-2 shows the potentially harmful
Many common household products contain chemicals that
can contaminate ground water and should not be disposed
of in septic systems.
10
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Table 3-1. Typical Sources of Potential Ground Water Contamination by Land Use Category
Category
Contaminant Source
Agriculture
Commercial
Industrial
Residential
Other
Animal burial areas
Animal feedlots
Fertilizer storage/use
Airports
Auto repair shops
Boat yards
Construction areas
Car washes
Cemeteries
Dry cleaners
Gas stations
Golf courses
Asphalt plants
Chemical manufacture/storage
Electronics manufacture
Electroplaters
Foundries/metal fabricators
Machine/metalworking shops
Mining and mine drainage
Fuel oil
Furniture stripping/refinishing
Household hazardous products
Household lawns
Hazardous waste landfills
Municipal incinerators
Municipal landfills
Municipal sewer lines
Open burning sites
Irrigation sites
Manure spreading areas/pits
Pesticide storage/use
Jewelry/metal plating
Laundromats
Medical institutions
Paint shops
Photography establishments
Railroad tracks and yards
Research laboratories
Scrap and junkyards
Storage tanks
Petroleum production/storage
Pipelines
Septage lagoons and sludge sites
Storage tanks
Toxic and hazardous spills
Wells (operating/abandoned)
Wood preserving facilities
Septic systems, cesspools
Sewer lines
Swimming pools (chemical storage)
Recycling/reduction facilities
Road deicing operations
Road maintenance depots
Storm water drains/basins
Transfer stations
Source: U.S. EPA, 1991 a.
components of common household products. Similarly,
many substances used in industrial processes should not
be disposed of in drains at the workplace because they
could contaminate a drinking water source. Companies
should train employees in the proper use and disposal of
all chemicals used onsite. The many different types and
the large quantities of chemicals used at industrial loca-
tions make proper disposal of wastes especially important
for ground water protection.
Chemical Storage and Spills
Underground and aboveground storage tanks are com-
monly used for chemical storage. Approximately five mil-
lion underground storage tanks exist in the United States
(U.S. EPA, 1990a). Some homes have underground fuel
tanks for heating oil. Many businesses and municipal
highway departments also store fuel oil, diesel, gasoline,
or other chemicals in onsite tanks. Industries use storage
tanks to hold chemicals used in industrial processes or
to store hazardous wastes for pickup by a licensed hauler.
If an underground storage tank develops a leak, which
commonly occurs as the tank ages and corrodes, chemi-
cals can migrate through the soil and reach the ground
water. It has been estimated that about one-third of un-
derground storage tanks nationwide are leaking (U.S.
EPA, 1990a). Newer tanks are more corrosion-resistant,
but they are not foolproof. Abandoned underground tanks
pose another problem because their location often is un-
known. Aboveground storage tanks can also pose a
11
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rv>
Airborne Sulfur &
Nitrogen Compounds
Wfff Acid Rain
"' Recharge to
Ground Water and
Surface Water
Infiltration to
Ground Water
Not drawn to scale
Figure 3-2. Some potential sources of ground water contamination. Source: Adapted from Paly and Steppacher, n.d.
-------
Table 3-2. Potentially Harmful Components of Common Household Products
Product Toxic or Hazardous Components
Antifreeze (gasoline or coolants systems)
Automatic transmission fluid
Battery acid (electrolyte)
Degreasers for driveways and garages
Degr&asers for engines and metal
Engine and radiator flushes
Hydraulic fluid (brake fluid)
Motor oils and waste oils
Gasoline and jet fuel
Diesel fuel, kerosene, #2 heating oil
Grease, lubes
Rustproofers
Car wash detergents
Car waxes and polishes
Asphalt and roofing tar
Paints, varnishes, stains, dyes
Paint and lacquer thinner
Paint and varnish removers, deglossers
Paint brush cleaners
Floor and furniture strippers
Metal polishes
Laundry soil and stain removers
Other solvents
Rock salt
Refrigerants
Bug and tar removers
Household cleansers, oven cleaners
Drain cleaners
Toilet cleaners
Cesspool cleaners
Disinfectants
Pesticides (all types)
Photochemicals
Printing ink
Wood preservatives (creosote)
Swimming pool chlorine
Lye or caustic soda
Jewelry cleaners
Methanol, ethylene glycol
Petroleum distillates, xylene
Sulfuric acid
Petroleum solvents, alcohols, glycol ether
Chlorinated hydrocarbons, toluene, phenols, dichloroperchloroethylene
Petroleum solvents, ketones, butanol, glycol ether
Hydrocarbons, fluorocarbons
Hydrocarbons
Hydrocarbons
Hydrocarbons
Hydrocarbons
Phenols, heavy metals
Alkyl benzene sulfonates
Petroleum distillates, hydrocarbons
Hydrocarbons
Heavy metals, toluene
Acetone, benzene, toluene, butyl acetate, methyl ketones
Methylene chloride, toluene, acetone, xylene, ethanol, benzene, methanol
Hydrocarbons, toluene, acetone, methanol, glycol ethers, methyl ethyl
ketones
Xylene
Petroleum distillates, isopropanol, petroleum naphtha
Hydrocarbons, benzene, trichloroethylene, 1,1,1-trichloroethane
Acetone, benzene
Sodium concentration
1,1,2-trich loro-1,2,2-trif luoroethane
Xylene, petroleum distillates
Xylenols, glycol ethers, isopropanol
1,1,1-trichloroethane
Xylene, sulfonates, chlorinated phenols
Tetrachloroethylene, dichlorobenzene, methylene chloride
Cresol, xylenols
Naphthalene, phosphorus, xylene, chloroform, heavy metals, chlorinated
hydrocarbons
Phenols, sodium sulfite, cyanide, silver halide, potassium bromide
Heavy metals, phenol-formaldehyde
Pentachlorophenols
Sodium hypochlorite
Sodium hydroxide
Sodium cyanide
Source: "Natural Resources Facts: Household Hazardous Wastes," Fact Sheet No. 88-3, Department of Natural Science, University of Rhode Island,
August 1988.
13
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threat to ground water if a spill or leak occurs and ade-
quate barriers are not in place.
If an underground storage tank develops a leak, chemicals
can migrate through the soil and reach the ground water.
Improper chemical storage, sloppy materials handling,
and poor quality containers can be major threats to
ground water. Tanker trucks and train cars pose another
chemical storage hazard. Each year, approximately
16,000 chemical spills occur from trucks, trains, and stor-
age tanks, often when materials are being transferred
(U.S. EPA, 1990a). At the site of an accidental spill, the
chemicals are often diluted with water, washing the
chemical into the soil and increasing the possibility of
ground water contamination (Pettyjohn, 1989).
Chemical spills from trucks and trains can threaten ground
water supplies.
Landfills
Solid waste is disposed of in thousands of municipal and
industrial landfills throughout the country. Chemicals that
should be disposed of in hazardous waste landfills some-
times end up in municipal landfills. In addition, the dis-
posal of many household wastes is not regulated. Once
in the landfill, chemicals can leach into the ground water
byjneans of precipitation and surface runoff. New landfills
are required to have clay or synthetic liners and leachate
(liquid from a landfill containing contaminants) collection
systems to protect ground water. Most older landfills,
however, do not have these safeguards. Older landfills
were often sited over aquifers and in permeable soils with
shallow water tables, enhancing the potential for leachate
to contaminate ground water. Closed landfills can con-
tinue to pose a ground water contamination threat if they
are not capped with an impermeable material (such as
clay) before closure (U.S. EPA, 1990a).
Improperly sited or constructed landfills can be a source
of ground water contamination.
Surface Impoundments
Surface impoundments are relatively shallow ponds
or lagoons used by industries and municipalities to
store, treat, and dispose of liquid wastes. As many
as 180,000 surface impoundments exist in the United
States. Like landfills, new surface impoundments facilities
are required to have liners, but even these liners some-
times leak.
Sewers and Other Pipelines
Sewer pipes carrying wastes sometimes leak fluids into
the surrounding soil and ground water. Sewage consists
of organic matter, inorganic salts, heavy metals, bacteria,
viruses, and nitrogen (U.S. EPA, 1990a). Other pipelines
carrying industrial chemicals and oil brine have also been
known to leak, especially when the materials transported
through the pipes are corrosive.
Pesticide and Fertilizer Use
Millions of tons of fertilizers and pesticides (including her-
bicides, insecticides, rodenticides, fungicides, and avi-
cides) are used annually in the United States for crop
production. In addition to farmers, homeowners, busi-
nesses (such as golf courses), utilities, and municipalities
14
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Sewer pipes sometimes leak fluids into the surrounding
soil and ground water.
also use these chemicals. A number of these pesticides
and fertilizers (some highly toxic) have entered and con-
taminated ground water following normal, registered use.
Some pesticides remain in soil and water for many
months to many years. Another potential source of ground
water contamination is animal wastes on farm feedlots
that percolate into the ground. Feedlots should be prop-
erly sited and wastes should be removed at regular
intervals.
Pesticides and fertilizers have contaminated ground water
following normal, registered use.
EPA's Office of Pesticides and Toxic Substances and Of-
fice of Water conducted a National Pesticide Survey
(NPS) between 1985 and 1992. The purpose of the sur-
vey was to determine the number of drinking water wells
nationwide containing pesticides and nitrates and the
concentration of these substances. It also analyzed the
factors associated with contamination of drinking water
wells by pesticides and nitrates. The survey included
samples from more than 1,300 public community and
rural domestic water supply wells. The NPS found that
approximately 3.6 percent of the wells contained concen-
trations of nitrates above the federal maximum contami-
nant level, and that over half of the wells contained ni-
trates above the survey's minimum reporting limit for
nitrate (0.15 mg/L).
The NPS also reported that approximately 0.8 percent of
the wells tested contained pesticides at levels higher than
federal maximum contaminant levels or health advisory
levels. Only 10 percent of the wells classified as rural
were actually located on farms. The incidence of contami-
nation by agricultural chemicals in farm wells used for
drinking water is greater.
After further analysis, EPA estimated that for the wells
that contain pesticides, a significant percentage probably
contain the chemical at concentrations exceeding these
federal health-based limits (e.g., maximum contaminant
levels or health advisory levels). Approximately 14.6 per-
cent of the wells tested contained one or more pesticides
above the minimum reporting limit set in the survey. (EPA
established specific minimum reporting limits for each
pesticide tested for in the NPS, ranging from 0.10 u.g/L
for dibromochloropropane to 4.5 u,g/L for ethylene
thiourea.) The most common pesticides found were
atrazine and metabolites (breakdown products) of di-
methyl tetrachloroterephthalate (DCPA, commonly known
as Dacthal), used in many utility easement weed control
programs and for lawn care. Table 3-3 lists the percent-
ages of wells in the survey in which pesticides and/or
nitrates were found (U.S. EPA, 1990e; U.S. EPA, 1992).
Improperly Constructed Wells
Several problems associated with improperly constructed
wells can result in ground water contamination from the
introduction of contaminated surface or ground water.
Types of wells that are a source of potential ground water
contamination include:
• Sumps and dry wells, which collect storm water runoff
and spilled liquids and are used for disposal. These
wells sometimes contain contaminants such as used
oil and antifreeze that may discharge into water supply
areas.
• Drainage wells, which are used in wet areas to remove
some of the water and transport it to deeper soils.
These wells may contain agricultural chemicals and
bacteria (U.S. EPA, 1990a).
• Injection wells, which are commonly used to dispose
of hazardous and non-hazardous industrial wastes.
These wells can range from a depth of several hundred
to several thousand feet. If properly designed and
used, these wells can effectively dispose of wastes. But
undesirable wastes can be introduced into ground
water from injection wells when the well is located di-
rectly in an aquifer, or if leakage of contaminants oc-
curs from the well head or casing or through fractures
in the surrounding rock formations (U.S. EPA, 1990a).
15
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Table 3-3. National Estimates for Pesticides and Nitrates in Wells
Estimated
Number
95% Confidence Estimated
Interval (Lower-Upper) Percent
95% Confidence
Interval
(Lower-Upper)9
PESTICIDES
CWS" wells nationally with at 9,850
least one pesticide
CWS wells above HAL0 0
CWS wells above MCLd 0
Rural domestic wells 446,000
nationally with at least one
pesticide
Rural domestic wells above 19,400
HALC
Rural domestic wells above 60,900
MCLd
NITRATES
CWS wells nationally 49,300
CWS wells above MCLd 1,130
Rural domestic wells nationally 5,990,000
Rural domestic wells above 254,000
MCLd
(6,330 - 13,400) 10.4
(0 - 750) 0
(0 - 750) 0
(246,000 - 647,000) 4.2
(170-131,000) 0.2
(9,430-199,000) 0.6
(45,000 - 53,300) 52.1
(370 - 2,600) 1.2
(5,280,000 - 6,700,000) 57.0
(122,000-464,000) 2.4
(6.8- 14.1)
(0 - 0.8)
(0 - 0.8)
(2.3 - 6.2)
(<0.1 - 1.2)
(0.1 - 1.9)
(48.0 - 56.3)
(0.4 - 2.7)
(50.3 - 63.8)
(1.2-2.4)
•Numbers between zero and 0.05 are reported as less than 0.1 (<0.1).
"CWS — Community Water Supply.
'Health Advisory Level (HAL) is the concentration of a contaminant in water that may be consumed over a person's lifetime without harmful effects.
HALs are non-enforceable health-based guidelines that consider only non-cancer toxic effects. Only pesticides with HALs were included in estimating
the number of wells containing pesticides above the HALs.
dMaximum Contaminant Level (MCL) is the maximum permissible level of a contaminant in water that is delivered to any user of a public water
system. MCLs are enforceable standards. Only pesticides with MCLs were included in estimating the number of wells containing pesticides above
the MCLs. Although the MCL is not legally applicable to rural domestic wells, it was used as a standard of quality for drinking water.
Source: U.S. EPA, 1990e.
Improperly abandoned wells act as a conduit through
which contaminants can reach an aquifer if the well
casing has been removed, as is often done, or if the
casing is corroded. In addition, some people use aban-
doned wells to dispose of wastes such as used motor
oil; these wells may reach into an aquifer that serves
drinking water supply wells. Abandoned exploratory
wells (e.g., for gas, oil, coal) or test hole wells are
usually uncovered and are a potential conduit for con-
taminants.
Active drinking water supply wells that are poorly con-
structed can result in ground water contamination.
Construction problems, such as faulty casings, inade-
quate covers, or lack of concrete pads, allow outside
water and any accompanying contaminants to flow into
the well. Sources of such contaminants can be surface
runoff or wastes from farm animals or septic systems.
Contaminated fill packed around a well can also de-
grade well water quality. Well construction problems
are more likely to occur in older wells that were in place
prior to the establishment of well construction stand-
ards and in domestic and livestock wells.
• Poorly constructed irrigation wells also can allow con-
taminants to enter ground water. Often pesticides and
fertilizers are applied in the immediate vicinity of wells
on agricultural land.
Highway De icing
More than 11 million tons of salt are applied to roads in
the United States annually to remove ice from roadways
(U.S. EPA, 1990c). Precipitation can wash the salt into
soil and then into ground water. Stockpiles of salt stored
on the ground can also be washed into the soil. High
sodium levels in water pose a health risk and also dam-
age vegetation, vehicles, and bridges (Massachusetts
Audubon Society, 1987).
16
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Mining Activities
Active and abandoned mines can contribute to ground
water contamination. Precipitation can leach soluble min-
erals from the mine wastes (known as spoils or tailings)
into the ground water below. These wastes often contain
metals, acids, minerals, and sulfides. Abandoned mines
are often used as wells and waste pits, sometimes simul-
taneously. In addition, mines are sometimes pumped to
keep them dry; the pumping can cause an upward migra-
tion of contaminated ground water, which may be inter-
cepted by a well (U.S. EPA, 1990a).
Effects of Ground Water Contamination
Contamination of ground water can result in poor drinking
water quality, loss of a water supply, high cleanup costs,
high costs for alternative water supplies, and/or potential
health problems. Some examples include:
• In Truro, Massachusetts, a leaking underground stor-
age tank released gasoline into the aquifer in 1977.
The wellfield in nearby Provincetown had to be closed
to prevent contamination of the town's drinking water
supply. More than $5 million was spent on aquifer re-
habilitation. More than 13 years later, treatment was
still required, and daily monitoring will be required for
3 years following the completion of the aquifer reha-
bilitation program.
• The public water supply wells in Atlantic City, New
Jersey, were contaminated by leachate from a landfill;
the city estimated that a new wellfield would cost ap-
proximately $2 million.
• In Minnesota, 17 cities have spent more than $24 mil-
lion and 18 companies have expended more than $43
million because of ground water contamination (U.S.
EPA, 1991d; U.S. EPA, 1990c).
Degradation or Destruction of the Water
Supply
The consequences of a contaminated water supply often
are serious. In some cases, contamination of ground
water is so severe that the water supply must be aban-
doned as a source of drinking water. (For example, less
than 1 gallon of gasoline can render 1 million gallons of
ground water nonpotable [U.S. EPA, 1991c].) In other
cases, the ground water can be cleaned up and used
again, if the contamination is not too severe and if the
municipality is willing to spend a good deal of money.
Water quality monitoring is often required for many years.
Costs of Cleaning Up Contaminated
Ground Water
Because ground water generally moves slowly, contami-
nation often remains undetected for long periods of time.
This makes cleanup of a contaminated water supply dif-
ficult, if not impossible. If a cleanup is undertaken, it can
cost thousands to millions of dollars.
Once the contaminant source has been controlled or re-
moved, the contaminated ground water can be treated in
one of several ways:
• Containing the contaminant to prevent migration.
• Pumping the water, treating it, and returning it to the
aquifer.
• Leaving the ground water in place and treating either
the water or the contaminant.
A number of technologies can be used to treat ground
water. They most frequently include air stripping, acti-
vated carbon adsorption, and/or chemical treatment with
filtration. Different technologies are effective for different
types of contaminants, and several technologies are often
combined to achieve effective treatment. The effective-
ness of treatment depends in part on local hydrogeologi-
cal conditions, which should be evaluated prior to
selecting a treatment option (U.S. EPA, 1990a).
Costs of Alternative Water Supplies
Given the difficulty and high costs of cleaning up a con-
taminated aquifer, some communities choose to abandon
existing wells and use other water sources, if available.
Using alternative supplies will probably be more expen-
sive than obtaining drinking water from the original
source. A temporary and expensive solution is to pur-
chase bottled water, but this is not a realistic long-term
solution for a community's drinking water supply problem.
A community might decide to install new wells in a differ-
ent area of the aquifer. In this case, appropriate siting and
monitoring of the new wells are critical to ensure that
contaminants do not move into the new water supplies.
Potential Health Problems
A number of microorganisms and thousands of synthetic
chemicals have the potential to contaminate ground
water. Table 3-4 lists some of these substances and their
health risks. Drinking water containing bacteria and vi-
ruses can result in illnesses such as hepatitis, cholera,
or giardiasis. Methemoglobinemia or "blue baby syn-
drome," an illness affecting infants, can be caused by
drinking water high in nitrates. Benzene, a component of
gasoline, is a known human carcinogen. The serious
health effects of lead are well known: learning disabilities
in children; nerve, kidney, and liver problems; and preg-
nancy risks. These and other substances are regulated
by federal and state laws. Hundreds of other chemicals,
however, are not yet regulated, and many health effects
are unknown or not well understood. Preventing contami-
nants from reaching the ground water is the best way to
reduce the health risks associated with poor drinking
water quality.
17
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Table 3-4. Health Risks Associated with Contaminated Ground Water
Substance
Major Sources
Possible Risk
Lead
Fluoride
Metals
Nitrate
Microbiological Contaminants
Chlorinated Solvents
Pesticides and Herbicides
PCBs
Trihalomethanes
Asbestos
Radon
Piping and solder in distribution system
Geological
Geological, waste disposal practices
Fertilizer, treated sewage, feedlots
Septic systems, overflowing sewer lines
Industrial pollution, waste disposal
practices
Farming, horticultural practices
Transformers, capacitors
Treatment by-product
Geological, asbestos cement pipes
Geological radioactive gas
Learning disabilities in children, nerve
problems, birth defects
Crippling skeletal fluorosis, dental
fluorosis
Liver, kidney, circulatory effects
Methemoglobinemia
(Blue baby syndrome)
Acute gastrointestinal illness, meningitis
Cancer, liver, and kidney effects
Nervous system toxicity, probable cancer
Probable cancer, reproductive effects
Liver, kidney damage, possible cancer
Tumors
Cancer
Source: Adapted from Metealf & Eddy, 1989.
Regulations to Protect Ground Water
Several federal laws help protect ground water quality.
The Safe Drinking Water Act (SDWA) establishes the
Wellhead Protection Program and regulates the use of
underground injection wells for waste disposal. It also
provides EPA and the states with the authority to ensure
that drinking water supplied by public water systems
meets minimum health standards. The Clean Water Act
regulates ground water shown to have a connection with
surface water. It sets standards for allowable pollutant
discharges. The Resource Conservation and Recovery
Act (RCRA) regulates treatment, storage, and disposal of
hazardous and non-hazardous wastes. The Comprehen-
sive Environmental Response, Compensation, and Liabil-
ity Act (CERCLA, or Superfund) authorizes the
government to clean up contamination or sources of po-
tential contamination from hazardous waste sites or
chemical spills, including those that threaten drinking
water supplies. CERCLA includes a "community right-to-
know" provision. The Federal Insecticide, Fungicide, and
Rodenticide Act (FIFRA) regulates pesticide use. The
Toxic Substances Control Act (TSCA) regulates manufac-
tured chemicals. The SDWA and RCRA are discussed in
more detail below.
The Safe Drinking Water Act
As specified in the SDWA, EPA sets standards for maxi-
mum contaminant levels (the maximum permissible level
of contaminant in water delivered to any user of a public
water system) in public drinking water supplies, regulates
underground disposal of wastes, designates sole-source
aquifers, and establishes public water supply protection
programs. By 1986, EPA had developed standards for 34
contaminants, including microorganisms, pesticides, ra-
dionuclides, volatile synthetic organic chemicals, and
some heavy metals.
Amendments to the SDWA were passed in 1986 to en-
hance drinking water protection. These amendments in-
cluded the Wellhead Protection Program and the Sole
Source Aquifer Demonstration Program. EPA provides
technical assistance to the states, which implement these
two programs. The 1986 amendments also required EPA
to set drinking water standards for 83 contaminants and
for an additional 25 contaminants every 3 years. Table
3-5 lists current federal drinking water standards, ex-
pressed as maximum contaminant levels. In addition, the
amendments required EPA to develop regulations for pub-
lic drinking water systems to monitor unregulated con-
taminants.
Wellhead protection emphasizes the prevention of drink-
ing water contamination as a principal goal, rather than
relying on correction of contamination once it occurs. Un-
der the SDWA, each state must prepare a Wellhead Pro-
tection Program and submit it to EPA for approval. Certain
elements must be included in the program, but the law
provides flexibility for states so that they can establish
programs that suit local needs in protecting public water
supplies. State wellhead protection programs must:
18
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Specify the roles and duties of state agencies, local
government offices, and public water suppliers regard-
ing development and implementation of the program.
Delineate a wellhead protection area for each well-
head, based on hydrogeologic and other relevant in-
formation. Delineation criteria might include distance
from the well, drawdown of water from the well, time
of travel of water and/or contaminants to reach the
well, hydrologeologic boundaries, and assimilative ca-
pacity (such as the ability of soils to keep contaminants
from reaching ground water at unacceptable levels).
Identify sources of contamination within each wellhead
protection area.
Develop management approaches (such as ap-
proaches for designating a lead agency; acquiring
technical and financial assistance; and implementing
training, demonstration projects, and education pro-
grams).
Prepare contingency plans (plans for alternative drink-
ing water supplies) for each public water supply system.
Identify sites for new wells that would protect them
from potential contamination.
• Ensure public participation.
Wellhead protection programs require the participation of
all levels of government. The federal government (EPA)
approves state wellhead protection programs and pro-
vides technical assistance, state governments develop
and execute the programs, and local governmental bod-
ies implement wellhead protection programs in their ar-
eas. Figure 3-3 shows states with approved wellhead
protection programs.
The Resource Conservation and
Recovery Act
The Resource Conservation and Recovery Act (RCRA)
regulates the storage, transport, treatment, and disposal
of hazardous and solid wastes to prevent contaminants
from leaching into ground water from municipal landfills,
underground storage tanks, surface impoundments, and
hazardous waste disposal facilities. The "cradle to grave"
mandate of RCRA requires a trail of paperwork (a mani-
fest document) to follow a hazardous waste from the point
of generation, through transport and storage, to final
disposal, to ensure proper handling of the wastes and
provide accountability. RCRA includes technology re-
PUERTO
RICO
HAWAII
PZ3 WHP PROGRAMS APPROVED
Figure 3-3. States with EPA-approved wellhead protection programs as of February 1993.
19
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Table 3-5. Maximum Contaminant Levels (MCLs) for
Chemicals
ORGANICS
Acrylamide
Acrylonitrile
Adipates (diethylhexyl)
Alachlor
Aldicarb
Aldicarb sulfone
Aldicarb sulfoxide
Atrazine
Bentazon
Benz(a)anthracene (PAH)
Benzene
Benzo(a)pyrene (PAH)
Benzo(b)fluoranthene (PAH)
Benzo(k)fluoranthene (PAH)
Bromacil
Bromobenzene
Bromochloroacetonitrile
Bromodichloromethane (THM)
Bromoform (THM)
Bromomethane
Butyl benzyl phthalate (PAE)
Carbofuran
Carbon tetrachloride
Chloral hydrate
Chlordane
Chlorodibromomethane (THM)
Chloroethane
Chloroform (THM)
Chloromethane
Chloropicrin
Chlorotoluene o-
Chlorotoluene p-
Chrysene (PAH)
Cyanazine
Cyanogen chloride
2,4-D
DCPA (Dacthal)
Dalapon
Di[2-ethylhexyl]adipate
Dibenz(a,h)anthracene (PAH)
Dibromoacetonitrile
Dibromochloropropane (DBCP)
Dibromomethane
Dicamba
Dichloroacetaldehyde
Dichloroacetic acid
Regulatory
Status
F
L
P
F
F
F
F
F
L
P
F
P
P
P
L
L
L
L
L
L
P
F
F
L
F
L
L
L
L
L
L
L
P
L
L
F
L
P
P
P
L
F
L
L
L
L
MCL
(mg/L)
TT
—
0.5
0.002
0.003
0.002
0.004
0.003
—
0.0001
0.005
0.0002
0.0002
0.0002
0.1
0.1
0.1
0.04
0.005
—
0.002
0.1
0.1
—
—
—
0.0002
—
—
0.07
0.2
0.4
0.0003
0.0002
— —
—
Chemicals
Dichloroacetonitrile
Dichlorobenzene o-
Dichlorobenzene m-a
Dichlorobenzene p-
Dichlorodifluorom ethane
Dichloroethane (1,1-)
Dichloroethane (1 ,2-)
Dichloroethylene (1,1-)
Dichloroethylene (cis-1,2-)
Dichloroethylene (trans-1,2-)
Dichloromethane
Dichloropropane (1,2-)
Dichloropropane (1,3-)
Dichloropropane (2,2-)
Dichloropropene (1,1-)
Dichloropropene (1,3-)
Diethylhexyl phthalate (PAE)
Dinitrotoluene (2,4-)
Dinitrotoluene (2,6-)
Dinoseb
Diquat
Endothall
Endrin
Epichlorohydrin
Ethylbenzene
Ethylene dibromide (EDB)
ETU
Fluorotrichloromethane
Glyphosate
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloroethane
Hypochlorite
lndeno(1 ,2,3,-c,d)pyrene
(PAH)
Isophorone
Lindane
Methomyl
Methoxychlor
Methyl tert butyl ether
Metolachlor
Metribuzin
Monochloroacetic acid
Monochlorobenzene
Oxamyl (Vydate)
Regulatory
Status
L
F
F
F
L
L
F
F
F
F
P
F
L
L
L
L
P
L
L
P
P
P
P
F
F
F
L
L
P
F
F
P
L
P
L
L
P
L
F
L
F
L
L
L
L
F
P
MCL
(mg/L)
—
0.6
0.6
0.075
—
—
0.005
0.007
0.07
0.1
0.005
0.005
—
—
—
—
0.004
—
—
0.007
0.02
0.1
0.002
TT
0.7
0.00005
—
—
0.7
0.0004
0.0002
0.001
—
0.05
—
—
0.0004
—
0.0002
0.04
—
"
.
0.1
0.2
20
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Table 3-5. Maximum Contaminant Levels (MCLs) for
Drinking Water (continued)
Chemicals
Ozone by-products
Pentachlorophenol
Picloram
Polychlorinated biphenyls
(PCBs)
Prometon
Simazine
Styrene
2,3,7,8-TCDD (Dioxin)
2,4,5-T
Tetrachloroethane (1,1,2,2-)
Tetrachloroethylene
Toluene
Toxaphene
2,4,5-TP
Trichloroacetic acid
Trichloroacetonitrile
Trichlorobenzene (1,2,4-)
Trichloroethane (1,1,1-)
Trichloroethane (1,1,2-)
Trichloroethanol (2,2,2-)
Trichloroethylene
Trichlorophenol (2,4,6-)
Trichloropropane (1 ,2,3-)
Trifluralin
Vinyl chloride
Xylenes
INORGANICS
Aluminum
Antimony
Arsenic
Asbestos (fibers/l>10 urn
length)
Barium
Beryllium
Boron
Cadmium
Chloramine
Chlorate
Chlorine
Chlorine dioxide
Chlorite
Chromium (total)
Copper
Cyanide
Fluoride0
Lead (at tap)
Regulatory
Status
L
F
P
F
L
P
F
P
L
L
F
F
F
F
L
L
P
F
P
L
F
L
L
L
F
F
L
P
c
F
MCL
(mg/L)
—
0.001
0.5
0.0005
—
0.004
0.1
5E-08
—
—
0.005
1
0.003
0.05
—
—
0.07
0.2
0.005
—
0.005
—
—
—
0.002
10
—
0.006
0.05
7MFL
Regulatory
Chemicals Status
Manganese L
Mercury (inorganic) F
Molybdenum L
Nickel P
Nitrate (as N) F
Nitrite (as N) F
Nitrate + Nitrite (both as N) F
Selenium F
Strontium L
Sulfate P
Thallium P
Vanadium L
Zinc L
Zinc chloride (measured as L
Zinc)
RADIONUCUDES
Beta particle and photon F
activity (formerly
man-made radionuclides)
Gross alpha particle activity F
Radium 226/228 P
Radon P
Uranium P
MICROBIOLOGY
Cryptosporidium L
Giardia lamblia F
Legionella F*
Standard Plate Count F*1
Total Coliforms (after F
12/31/90)
Turbidity (after 12/31/90) F
Viruses F"
MCL
(mg/L)
—
0.002
—
0.1
10
1
10
0.05
—
400/500
0.002
—
—
—
4 mrem
15 pCi/L
5 pCi/L
300 pCi/L
20 ug/l
—
TT
TT
TT
**•
PS
TT
"The values for m-dichlorobenzene are based on data for o-dichloroben-
F
P
L
F
L
L
L
L
L
F
F
P
F
F
2
0.001
—
0.005
^_
—
—
"
0.1
TT*
0.2
4
Tf
zene.
bCopper — action level 1 .3 mg/L; Lead — action level
°Under review.
0.01 5 mg/L
dRnal for systems using surface water; also being considered for regu-
lation under ground water disinfection rule.
Key:
F - final
L - listed for regulation
P - proposed (Phase II and V. proposals)
PS - performance standard 0.5 NU - 1.0 NU
TT - treatment technique
MFL - million fibers per liter
** - No more than 5% of the samples per month may be positive.
For systems collecting fewer than 40 samples/month, no more
than 1 sample per month may be positive.
Source: U.S. Environmental Protection Agency, Office
of Water, Drink-
ing Water Regulations and Health Advisories, November 1 992.
21
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MONITORING WAIVERS
In certain cases, having a wellhead protection pro-
gram in place may help a system obtain a waiver from
some of the monitoring requirements under The Safe
Drinking Water Act. Individual states have the authority to
issue waivers consisting of statewide or areawide waivers
for specific contaminants or individual system waivers.
There are two types of monitoring waivers available: use
waivers and susceptibility waivers. EPA allows monitoring
waivers for asbestos, inorganic chemicals, synthetic or-
ganic chemicals, and volatile organic chemicals. Waivers
are not allowed for nitrate/nitrite or for the monitoring re-
quirements under the lead and copper rule.
Use waivers may be granted when it can be shown
that a contaminant has not been used, manufactured, or
stored in the area. A susceptibility waiver is based on prior
analytic results and the environmental persistence and
transport of the contaminant. There also are provisions to
allow grandfathering, using previous analyses and com-
positing for specific contaminants, at the states' discretion.
Systems should request monitoring waivers and fur-
ther information from their state primacy agency.
quirements for treatment, storage, and disposal facilities,
such as the installation of double liners and leachate
detection and collection systems, ground water monitor-
ing, and site inspections.
In 1984, Congress passed the Hazardous and Solid
Waste Amendments (HSWA) to RCRA. These amend-
ments promote waste reduction, recycling, and treatment
of hazardous wastes by requiring generators to certify in
writing that they have taken steps to reduce the volume
of hazardous wastes (such as source separation, recy-
cling, substitution of materials, or manufacturing process
changes). Generators are also encouraged to reduce the
toxicity of their wastes if possible through various physi-
cal, chemical, or biological processes. HSWA also incor-
porates into RCRA the regulation of small quantity
generators and underground storage tanks.
The 1984 amendments also included a Land Disposal
Restrictions (LDR) Program, which prohibits land disposal
of certain hazardous wastes unless they are treated ac-
cording to set standards, thus expanding ground water
protection measures. The standards specify either a con-
centration level or a method of treatment to render wastes
less hazardous. The LDRs do not apply if EPA determines
that the hazardous constituents will not migrate. Sub-
stances such as dioxins, some solvents, liquid hazardous
wastes containing certain metals, cyanides, PCBs, halo-
genated organic compounds, and acidic wastes are cov-
ered by the LDR program.
HSWA also included more stringent standards for land
disposal facilities for hazardous wastes, such as stricter
structural and design conditions for landfills and surface
impoundments (e.g., two or more liners, leachate collec-
tion systems above and between liners, and ground water
monitoring); construction of facilities only in areas with
suitable hydrogeologic conditions; and corrective actions
if a hazardous waste is released.
In 1991, under RCRA, EPA developed revised criteria for
municipal solid waste landfills that protect surface water
and ground water from contamination. The criteria include
location restrictions (such as restrictions on siting near
wetlands, floodplains, or unstable areas, such as karsts);
operating requirements (including a ban on hazardous
wastes and liquid restrictions to control leachate sources);
design standards; recordkeeping; closure and post-clo-
sure procedures; and ground water monitoring and cor-
rective action. The ground water monitoring requirements
include location, design, and installation requirements;
standards for sampling and analysis; and statistical meth-
ods for identifying significant changes in ground water
quality. If significant changes in ground water quality do
occur, an assessment of the nature and extent of con-
tamination (including the establishment of background
values and ground water protection standards), and
evaluation and implementation of remedial measures
must be undertaken by the owner or operator.
In addition, to determine geographic boundaries for a
landfill to which the new solid waste criteria apply, state
agencies must review the hydrogeologic characteristics
of the area, the volume and characteristics of the
WISCONSIN'S GROUND WATER
STANDARDS LAW
Wisconsin passed a Groundwater Standards Law in
1984, which includes enforcement standards and preven-
tive action limits for 60 substances that have been de-
tected in or have the potential to reach ground water in
the state. All applicable state programs (such as programs
overseeing landfills, hazardous waste, wastewater
sludge, septic tanks, salt storage, pesticides and fertiliz-
ers, and underground storage tanks) must use these
standards. Depending on whether the substance is a car-
cinogen, is associated with other health risks, or is regu-
lated only for aesthetic reasons, the preventive action limit
is set at 10, 20, or 50 percent of the enforcement stand-
ard, respectively. The preventive action limit serves as an
"early warning system," letting state agencies know that
low concentrations of certain substances are appearing
in ground water. Several state departments are responsi-
ble for various aspects of ground water protection, as is
the case in most states. Ground water activities are inte-
grated through a Groundwater Coordinating Council,
which includes representatives from individual agencies.
The Council has established a statewide ground water
management program (Wisconsin Department of Natural
Resources, 1989).
22
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leachate, ground water quantity and direction of flow,
ground water quality (including other sources of contami-
nation and cumulative impacts on ground water), the
proximity and withdrawal rate of ground water users, and
the availability of alternative drinking water supplies.
State Programs and Regulations to Protect
Ground Water
Many states are in the process of developing comprehen-
sive ground water protection strategies. State ground
water protection programs often include several compo-
nents: a comprehensive plan for ground water protection,
a set of standards to use to determine when an aquifer
is contaminated, a ground water use classification sys-
tem, land use management, and funding for implementa-
tion of the program. State ground water protection
programs often provide oversight and technical assis-
tance to municipalities.
States also regulate underground storage tanks and pes-
ticide use, sale, application, and disposal. Ground water
protection efforts in Wisconsin and underground storage
tank regulations in Massachusetts (see boxes) are exam-
ples of state ground water protection activities.
UNDERGROUND STORAGE TANK
REGULATIONS IN MASSACHUSETTS
In Massachusetts, underground storage tank regula-
tions were updated in 1986 to include flammable, explo-
sive, and leaking materials from tanks. The current
regulations require owners of new and existing tanks to
obtain permits from local fire departments that include the
size, age, type, location, and use of each tank. New stor-
age facilities must meet design standards to prevent
leaks, and installation must be performed by contractors
certified by the tank manufacturer. Requirements for leak
detection include a continuous monitoring system or in-
ventory control, and tank and pipe tests. The regulations
outline specific procedures to follow if a leak is detected.
A secondary containment system is required for all tanks
installed within Zone 2 (the zone of contribution) of a
public supply well (or within a one-half mile radius if Zone
2 has not been delineated).* The fire department may
require that new tanks installed within 500 feet of a private
well have secondary containment systems or equivalent
protection. The fire department also can deny an applica-
tion or impose conditions for replacement or modification
of a tank if it is determined that the proximity of the tank
to a public or private well, aquifer, recharge area, or sur-
face water body constitutes a danger to the public. Finally,
the fire department may require observation wells or other
leak detection systems on existing tanks that could
threaten public safety, Including water supplies (Massa-
chusetts Audubon Society, 1984).
'Zone 2 or the area of contribution is defined as "that area of ah
aquifer which contributes water to a well under the most severe
recharge and pumping conditions that can be realistically antici-
pated" (527 CMR 5.00, 9.00, 10.12).
23
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Chapter 4
The Five-Step Process for Wellhead Protection
The most effective way to protect the ground water used
as a public water supply is to establish a wellhead pro-
tection program. Through this program, you can manage
potential contamination sources on the land that contrib-
utes recharge to the well (see Chapter Three for a dis-
cussion of ground water contamination). Before planning
a wellhead protection program, it is important to contact
your state drinking water agency to determine whether
there are any state requirements for local wellhead pro-
tection programs. It is also advisable to determine who
might be able to help with the local planning process
(such as a state agency contact, the State Rural Water
Association, the local agricultural extension office, or the
EPA regional office). You then can begin to plan and
implement a wellhead protection program in five steps:
Step One Form a community planning team to initiate
and implement a wellhead protection
program.
Step Two Delineate the wellhead protection area.
This delineation should be compatible with
state or federal wellhead protection
requirements. The wellhead protection area
eventually may become part of a more
extensive ground water protection area.
Step Three Identify and locate potential sources of
contamination.
Step Four Manage the wellhead protection area. The
complexity of this step will vary depending
on the economic, industrial, and political
conditions in your community. Management
techniques can range from public education
to simple permitting restrictions to intricate
regulatory ordinances.
Step Five Plan for the future. This step concerns the
long-term effectiveness of the plan and
includes the development of a contingency
plan to ensure alternate public water
supplies if contamination occurs.
This chapter presents information to help your community
carry out each of these steps.
Before planning a wellhead protection program, it is impor-
tant to identify sources of expertise to assist with the plan-
ning process.
STEP ONE—Form a Community
Planning Team
Developing Community Representation
The first characteristic of a successful community plan-
ning team is representation from the diverse interests of
the community. The planning team might include:
• Public organizations: community service organiza-
tions, environmental groups, public interest groups,
League of Women Voters.
• Regulatory organizations: elected officials, local gov-
ernment agencies(health, planning, natural resources,
conservation), public works director.
• Government/public service organizations: fire de-
partment, public water supplier, local cooperative ex-
tension agent, county Soil Conservation Service office.
• Private organizations: businesses, farmers, land de-
velopers. (The participation of commercial and busi-
ness interests can enhance the effectiveness of the
team's protection strategy during the implementation
stages.)
25
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If wellhead protection areas cross community lines, it is
-critical to develop inter-jurisdictinnal relationships. This
process and will allow your team to determine the
Current quality of your ground water supply.
ensures consistency in designated land use and planning
restrictions and allows communities to work together to
protect your mutual resource. This interaction may involve
the regional planning board, neighboring community
boards, the agricultural extension service, and watershed
associations.
Meetings of the planning team should be advertised in a
local newspaper to attract as many concerned parties as
possible and to inform the public of the aims of the pro-
gram. It might be beneficial to contact your state ground
water office prior to your first meeting. This office might
be able to provide the team with valuable information and
guidance on wellhead protection.
Selecting the Team Leader
The effectiveness of the planning team often depends on
its leader's organizational and consensus-building skills.
A local official who is familiar with the community and
regulatory options and who has already gained commu-
nity support may be a good choice.
Defining the Goals and Objectives
of the Project
Once your planning team has been established, it is criti-
cal to define your team's main goals and the interim steps
necessary to reach them. The long-term goals should
include the delineation of a wellhead protection area to
protect your wells from unexpected contaminant releases
and the development of a management plan to control
high-risk activities within the well's recharge area.
These long-term goals cannot be achieved overnight;
therefore, a number of short-term objectives should be
devised to bring you closer to your ultimate aim of ground
water protection. Each step in the five-step process can
be broken down into smaller tasks that can be handled
easily by individuals on your team. Don't try to achieve
too much too soon; rather, set feasible short-term objec-
tives while maintaining sight of your long-term goals. Your
team's initial short-term objectives should include:
• Finding out whether your state has established a well-
head protection program and how it could be imple-
mented in your community.
• Becoming familiar with the geology of your community
and with the location of your community's wells and
the entire drinking water supply system. This knowl-
edge will give your team insight into your community's
existing and future water supply needs.
• Gathering all of the available information on the hydro-
logic and geologic nature of your community's under-
lying aquifers. This will form a basis for the delineation
of your wellhead protection area in Step Two of the
• Finding out about any existing sources of potential
contamination in your community and what measures
have been taken to safeguard your water supplies.
Often initial goals and objectives are revised or expanded
as the program develops and your planning team
becomes more familiar with the process of wellhead
protection.
Informing the Public
It is important to continually inform the public of your
progress in establishing a wellhead protection program.
This will help educate the community about the need to
protect ground water while generating support for the
program itself. It also gives members of the public an
opportunity to voice their suggestions or complaints about
the program. The success of the program will depend to
a great extent on public support for the program as well
as cooperation among those affected by the program and
those who monitor and enforce the wellhead protection
strategy.
Mailings, advertisements, flyers, and community meet-
ings are low-cost techniques for reaching a broad spec-
trum of the community. Questionnaires can both provide
information on the program and help the team gather
information on ground water issues, particularly in regard
to sources of contamination.
STEP TWO—Delineate the Wellhead
Protection Area
Reasons for Delineating a Wellhead
Protection Area
The purpose of delineating wellhead protection areas is
to define the geographic limits most critical to the protec-
tion of a wellfield. Water yielded by a well may have
traveled thousands of feet along surface (e.g., river) and
subsurface routes to reach the well. Any areas that re-
ceive recharge that contributes water to municipal supply
systems are known as "zones of contribution" (see Chap-
ter Two). These zones are subject to alterations in shape
and size depending on well pumping rates and other
factors. Zones of contribution should be defined in order
to begin protective management practices that could pre-
vent contamination from reaching a well.
Sources of Information
Under the provisions of the 1986 SDWA amendments,
many states have developed wellhead protection pro-
grams. A state program may recommend a particular de-
lineation method. Check with your state ground water
agency for guidance before you start delineating your
wellhead protection area. Your state may actually deline-
ate your wellhead protection area for you. Contact your
26
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Regional EPA office to find out the status of your state's
wellhead protection program (see Chapter Six for a listing
of EPA's Regional offices).
EPA Publications
The U.S. Environmental Protection Agency has published
many documents giving technical guidance on wellhead
protection area delineation techniques (see Chapter Six).
These documents describe a wide range of delineation
methods. Some are complex, involving computerized nu-
merical models. Others are simple, but effective, and in-
volve less time, fewer resources, or less expertise to
implement. In addition, EPA has published an easy-to-
use, semianalytical computer model to delineate wellhead
protection areas (see Chapter Six, Resources for Addi-
tional Information). Contact your Regional EPA office for
more information on EPA publications.
one source. Information collected for one purpose may
not be appropriate for another.
Topographic Maps (Quadrangle Maps). A good choice for
a base map is the U.S. Geological Survey (USGS) topo-
graphic map of your area (see Figure 4-1). These maps
are readily available. Each covers approximately 58
square miles and is usually at a scale of 1:24,000, where
1 inch corresponds to 2,000 feet, or 1:25,000 where 1
inch corresponds to 1,083 feet.2 In addition to marking
constructed features, these show important natural fea-
tures such as lakes and rivers. Most importantly, these
maps show the land surface contour elevations of the
area and allow the map user to visualize the three-dimen-
sional land surface. The scale of this map may be a little
small, depending on the size of your community. You
might choose to enlarge this base map to a scale of 1
inch to 1,000 feet. Other maps then can be reduced or
enlarged as necessary to overlay the base map. (Print
shops can enlarge these maps in full color at a relatively
low price.) In areas where unconfined aquifers occur, the
surface water elevations shown on the USGS topographic
map may provide a preliminary assessment of the hy-
draulic gradient and ground water flow directions.
Geologic Maps and Soil Maps. Geologic information is
available from many sources. Surficial and bedrock geo-
logic maps prepared by USGS geologists may be avail-
able for your community. These maps provide data on
land forms and soil profiles and should be consulted to
locate the permeable soils characteristic of recharge ar-
eas. Hydrogeologic mapping might be available from geo-
logic investigations, including geophysical surveys and
drilling programs. Bedrock maps and historical geologic
maps also may be available from your USGS regional
office. The U.S. Department of Agriculture Soil Conser-
vation Service has prepared soil maps and related reports
called "Soil Surveys" for a large portion of the United
States (see Figure 4-2). These maps delineate soils types
on aerial photographs. The soil survey report accompa-
nying these maps describes various hydrologic and physi-
cal characteristics of each soil type and could be very
useful in identifying recharge zones.
Aerial Photography and Satellite Imagery. Your regional
Department of Agriculture Soils Conservation Service or
Agricultural Stabilization and Conservation Service might
be able to supply you with aerial photography of your
community at a reasonable cost. Generally available in
stereo pairs, these photographs can be viewed through
stereoscopic glasses to give a three-dimensional, realistic
picture of your community. It is possible to have these
photographs enlarged, again at a reasonable cost, to
identify natural features and potential sources of ground
water contamination. Aerial photography can help map
The planning team should establish a base map of the
community.
Base Maps
The first step in any delineation technique involves gath-
ering as much information about the hydrologic and geo-
logic nature of your water resource area as possible. At
this stage the objective of the planning team should be
to establish a base map of the community, giving detailed
information on the natural features of the area, both sur-
face and subsurface, and showing the location of all pub-
lic supply wells and water supply sources. Table 4-1
shows the information contained on maps that may be
available for your community. You can obtain much of the
material you need from your town hall (Assessor's Office,
Engineering Department, Department of Public Works,
Water Board, Board of Health, Planning Board, Conser-
vation Commission), and from state, federal, and regional
natural resource agencies and planning departments.
Once a base map has been prepared, overlay maps can
be drawn up outlining drainage basins, wetlands, flood
zones, ground water resources, sewer service areas,
zoning districts, and land development plans.
The different types of maps that you can use to develop
your base map are described below. It is important to
consider the scale of the maps when using more than
Generally, distances and elevations on 1:24,000-scale maps are given
in conventional units (miles and feet) and on 1:25,000-scale maps in
metric units (kilometers and meters).
27
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Table 4-1. Information Available from Existing Mapping
Ground Water
Resources
Hydrogeologic Information
Soil
Loca- Hy- Profiles Surface
GW tion Trans- draulic and Water Drain-
GW Avail- of missiv- Stora- Conduc- Surface Re- Wet- Flood age
Quality ability Wells ity tivity tivity Geology sources lands Zones Basins
Location
of
Sewer Proposed Possible
Ser- Zoning Land Contam-
vice DIs- Develop- inant
Areas tricts ment Sources
00
Topographic Maps
Geologic Maps
Soils Maps
Aerial Photography
Satellite Imagery
Hydrologic System
Mapping
Wetlands Mapping
Flood Mapping (FEMA,
FIRM)
USGS Hydrologic
Atlases
Well Logs
Test Boring Logs
Water Table Maps
Land Use Maps
Zoning Maps
Roadway and Utility
Maps
'Test boring logs also may be used to obtain information on the subsurface geology of an area.
-------
SCALE 1:25000
o
1000 2000 3000 4000 5000 6000 7000 FEET
1 MILE
CONTOUR INTERVAL 10 FEET
NATIONAL GEODETIC VERTICAL DATUM OF 1929
Figure 4-1. Portion of the U.S. Geological Survey topographic map, Lexington Quadrangle.
29
-------
Scale 1:31,680
0
1 Mile
5000
5000 Feet
KEY
Bb Bemardslon gravelly silt bam. moderately steep
Be Bemardston gravelly silt bam. sloping phase
Df Dutchess gravelly silt loam, eroded hilly phase
(15-30% slopes)
Dh Dutchess gravelly silt loam, hilly phase
Dk Dutchess gravelly silt loam, undulating and rolling phases
Hg Hoosic gravelly loam, nearly level and undulating phases
Md Mansfield silt loam
Mg Muck, acid, deep phase
Me Nassau slaty silt loam, ledgy hilly phase
Ng Nassau slaty silt loam, undulating and rolling phases
Oa Ondawa gravelly loam, alluvai-lan phase
P» Pittsfield gravelly loam, sloping phase
PI Pittsfield-Wassaic gravelly loams, undulating and rolling
phases
Pm Pittstown gravelly silt loam, nearly level and gently sloping
phases
Se Steep ledgy land(Nassau soil material)
Sf Steep ledgy land (Wassaic and Straatsburg soil materials)
Sk Stockbridge gravelly loam, gently sloping phases
Wb Wassaic gravelly loam, ledgy hilly phase
Figure 4-2. Portion of a set of soils maps from a soil survey by the Soil Conservation Service, U.S. Department of
Agriculture and Cornell University Agricultural Experiment Station.
30
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readers gain a better understanding of the community's
surface geology. The planning team may choose to con-
sult with geologists or hydrogeologists who can view sat-
ellite imagery to detect trends of lineaments (distinctive
geologic features or characteristics), which might reflect
zones of high permeability. They can also view images to
detect shallow ground water where a high moisture con-
tent has brought about subtle changes (such as differ-
ences in vegetation) (U.S. EPA, 1990a).
Hydrologic System Mapping. You can draw from many
sources of data to prepare an overlay map of your com-
munity's hydrologic system. This system consists of drain-
age basins (watersheds), wetlands, and flood zones. The
map can be prepared on clear film and then overlaid on
your base map. Drainage basins or catchment areas col-
lect water that might be ultimately transported into the
aquifer. They are determined by finding the highest ele-
vation points on your topographic map and connecting
them by drawing boundary lines perpendicular to the sur-
face contours. The resulting area will probably be much
larger than your final wellhead protection area (and also
may be a very different area). Be aware of scale at the
level of detail.
Wetlands are mapped on topographic maps; however,
more detailed wetland mapping of your area may be avail-
able from your state wetlands regulatory agency or your
regional office of the U.S. Army Corps of Engineers. Wet-
land areas are critical elements of a drainage network
because they act as natural filters for contaminants in
surface water before it percolates down to ground water.
Flood mapping for every state has been prepared by the
Federal Emergency Management Agency (FEMA). Two
types of flood mapping are available: Flood Insurance
Rate Maps (FIRM) and Flood Boundary and Floodway
Maps (see Figure 4-3). These maps delineate the areas
adjacent to surface waters that would be under water in
100-year and 500-year floods. The 100-year and 500-
year floods are hypothetical flood events that might occur
once in 100 years and once in 500 years. Historic flood
data might also be available from your community and
state libraries.
Ground Water Mapping. A major source of information for
your ground water map is the USGS Hydrologic Atlases
(see Figure 4-4). These maps often show the location of
aquifers for entire river basins. They are based on the
interpretation of all available geologic information from
soil profiles, test wells, rock outcrops, observation wells,
seismic surveys, and other means of subsurface obser-
vation. The location of aquifers on these maps is esti-
mated by examining surficial geology, depth to bedrock,
and depth to the water table. Hydrologic atlases give
information on ground water availability, well locations,
ground water quality, surficial deposits influencing trans-
missivity, basin boundaries, flow characteristics of surface
water, and other hydrologic factors.
You can also obtain hydrogeologic information about your
aquifer from an analysis of well logs, both public and private,
and test boring logs. In addition to supplying geological
information on your community's aquifer, well records show
well discharge and water level fluctuations, which can be
used to evaluate an aquifer's hydraulic conductivity, trans-
missivity, and storativity (Pettyjohn, 1989a). Water table
maps, if available, can also be helpful in wellhead protection
area delineation. These maps give information on the flow
directions of ground water and its depth from the surface
(Figure 4-5). These maps should be available from your
state geology or ground water agency. Climatological data
can be obtained from your state weather service. These
data are important because they indicate precipitation
events and patterns, which influence surface runoff and
ground water recharge (U.S. EPA, 1991e).
In general, the following information should be included
on your team's ground water map (Massachusetts
Audubon Society, 1985b):
• The zone of influence and the zone of contribution for
every existing and potential water supply well.
• The location of aquifers and aquifer recharge zones.
• The watershed within which aquifers are located.
• Surface waters from which wells may induce recharge.
• Direction of ground water flow.
• Soil and geology maps.
Land Use Maps. Other maps that might prove useful
when determining potential contaminant sources and land
management techniques include community tax asses-
sors' maps, community zoning maps (see Figure 4-6),
community master development plan, maps of re-
served/conservation lands and waters (see Figure 4-7),
endangered species maps, and roadway and utility maps
(see Figures 4-8 and 4-9).
Once all the information is assembled, consider the
source for each part of the information and how accurate
the data are. You might wish to consider some information
more valuable than other.
Local Talent
Your community planning team can benefit greatly from
individuals within the community who have some exper-
tise, either in the technical aspects of wellhead protection
(engineers, water supply personnel, or agriculturists), or
in regulatory or planning issues. Another source of talent
is people from local universities or colleges that have
programs in geology, hydrology, agriculture, or civil and/or
environmental engineering. Faculty members of these in-
stitutions might be able to offer your planning team guid-
ance, while the institutions might offer the use of such
resources as testing laboratories, libraries, field testing
equipment, or computer facilities. Local expertise might
also be available from private businesses.
31
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-ZONE- ,
\. B ;
ZONES
UM«T OF
0ETA8I.EO STUDY
1000
APPROXIMATE SCALE
0
1000 FEET
i 1
3
500-Year Flood Boundary
100-Year Flood Boundary
Zone Designations* With
Date of Identification
e.g., 12/2/74
100-Year Flood Boundary
500-Year Flood Boundary
Base Flood Elevation Line
With Elevation In Feet**
Base Flood Elevation in Feet
Where Uniform Within Zone**
Elevation Reference Mark
Zone D Boundary
River Mile
-513-
(EL 987)
RM7X
• M1.5
"'Referenced to the National Geodetic Vertical Datum of 1929
Figure 4-3. Portion of the Rood Insurance Rate Map (FIRM) for the Town of Lexington, Massachusetts. Prepared by the
Federal Emergency Management Agency.
32
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"^sfesS^^l^^vl, !,
SCALE = 1:48 000
EXPLANATION
Aquifier Areas and Characteristics
STRATIFIED GLACIAL DEPOSITS
33 Transmissivity greater than 4,000 f^/d (poten-
.. .fg tial well yield greater than 300 gal/min).
Transmissivity 1,350 - 4,000 fftd (potential
well yieldtOO to 300 gal/min).
Transmissivity less than 1,350 ffrd (potential
well yield less than 100 gal/min).
Areas where transmissivity may be greater
than indicated by the color shown.
TILL DEPOSITS
Transmissivity 0-100 ffrd (potential well yield
less than 10 gal/min).
WELL LOCATIONS
Public water-supply or well field
Upper number identifies well. The U.S. Geo-
logical Survey numbers all wells consecutively
with each town. Lower number, if present, is re-
ported pumping capacity, in gallons per minute.
Observation wells
Wells where the U.S. Geological Survey
makes monthly water-level measurements.
Number is U.S.Geological Survey well number.
Figure 4-4. Portion of a U.S. Geological Survey Hydrologic Investigations Atlas - 662.
Water Table Map
Harwich, Massachusetts
Water Table Measurements Taken; 15 November 1991
• 12 Observation Well
"~ — Water Table Contour (feet, msl)
-^|— Direction of Ground Water Flow
300 0
600
scale (feet)
Figure 4-5. Water table map. Prepared by Horsley & Witten, Inc.
33
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SCALE
lobo'eoo' eoo' 460' 200' o
1000'
1800'
2000'
ZONING DISTRICTS
STANDARD ZONING DISTRICTS
RESIDENTIAL DISTRICTS
RO - One family dwelling
RS - One family dwelling
RT - Two family dwelling
[~] RM - Multi-family dwelling
H COMMERCIAL AND INDUSTRIAL DISTRICTS
CB - Central business
CLO - Local office
CM - Manufacturing
CN - Neighborhood business
CRO - Regional office
CRS - Retail ihopphg
CS - Service business
PLANNED DEVELOPMENT DISTRICTS
^| CD - Planned commercial
[T] RD - Planned residential
NOTtl IAOI nJUOICD DEVELOPMENT DISTRICT HAS DIFFERE&T
ITAMDA1DS AKD HUST CCMA1 HITE A SITE DEVELOPMENT AND
usi run APPROVED n m TOW KEETIHC.
OVERLAY DISTRICTS
WPD - Wetland protection
BOUNDARY LINES
BETWEEN RS & HO DISTRICTS
HISTORIC DISTRICTS
OITAILCO HATS SHCUIKG THE BOUNDARIES OF ALL tOHINC
DISTRICTS EXCEPT THE RO AND 15 DISTRICT AAE INCLUDED IN
THE BOOKLET 'EOHIKC DISTRICT MAPS' PUBLISHED BY THE
PLANNING BOARD.
STREET CLASSIFICATION
= STATE HIGHWAY OR TOWN STREET
=.•=.--= UNACCEPTED STREET *
Figure 4-6. Zoning map.
34
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I ^, ^'V.'.
dr^-^»»niior|tA V r'"• » ••i'V. "" . I '" '' s-J^&LVjAx*^U^7!A^3/A I '',
SCALE 1:18 000
Figure 4-7. Recreation and open space land use map.
PIAYFIELD
QUAS PUBLIC/
COMMERCIAL RECREATION
AND EASEMENTS
NON-TOWN OPEN SPACE
SCHOOL ||
PLAYGROUNCVPLAY AREA
35
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Figure 4-8. Utility map depicting existing drainage piping network.
Scale: 1" = 1,600'
Figure 4-9. Utility map depicting existing sewer network.
Scale: 1" = 1,600'
36
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Federal, State, and County Agencies
Fflftaral, stats, and nounly agencies can provide a wealth
tation. A team's choice of delineation method depends on
available resources, hydrogeologic conditions, state regu-
of information for your team. Much of the information de-
scribed above is readily available in the archives of these
agencies. (Massachusetts, for example, has developed a
hydrogeologic information matrix that lists every important
state, USGS, or consultant hydrogeologic report by geo-
graphic location.) It is worthwhile to contact as many of
these governmental agencies as possible, not only to obtain
their technical documents but also to receive guidance and
technical assistance. Some states have developed their
own water supply atlases with overlay maps depicting drain-
age basins, ground water parameters, the location of public
drinking water supplies, and the location of possible sources
of contamination. Agencies that may be helpful include
USGS, U.S. Department of Agriculture Soil Conservation
Service, U.S. Department of Fisheries and Wildlife, U.S.
EPA Office of Ground Water and Drinking Water, County
Extension Service, and state departments of health, envi-
ronment, or natural resources.
Methods for Delineating a Wellhead
Protection Area3
Several methods exist for delineating wellhead protection
areas. These range in complexity and cost of implemen-
latory agency requirements, and the specific goals and
objectives set by your community planning team. Most of
the more sophisticated techniques involve analytical
methods and/or computer modeling. If detailed townwide
mapping of aquifers is required, for example, communi-
ties may need to involve consultants at this stage. Advan-
tages and disadvantages of a number of delineation
techniques are summarized on page 47. Table 4-2 shows
the costs of delineation associated with each method
described below (U.S. EPA, 1987). These costs are rough
estimates only. If a large amount of data collection is
necessary, the upper end of the scale applies.
The delineation techniques described below refer to one
common type of aquifer: the permeable, granular aquifer
existing under unconfined conditions. For information
about delineation of wellhead protection areas in frac-
tured rocks or in confined-aquifer settings, see Appendi-
ces B and C.
3Most of the information on methods for delineation is summarized from
EPA's Guidelines for Delineation of Wellhead Protection Areas. This
publication should be consulted for more detailed technical information
on these techniques.
Table 4-2. Costs Associated with Various Wellhead Protection Area Delineation Methods
Method
Arbitrary Fixed Radii
Calculated Fixed Radii
Simplified Variable Shapes
Analytical Methods
Hydrogeologic Mapping
Numerical Modeling
1 Hourly wages per level of expertise
Person-Hours
Required per
Well
1-5
1-10
1-10
2-20
4-40
10-200+
assumed to be:
Level of
Expertise1
1
2
2
3
3
4
Cost per Well
$12-60
$17-170
$17-170
$60-600
$120-1,200
$350-7,000+
Potential
Overhead
Low
Low
Costs2
Low to Medium
Medium
Medium to
High
High
1. Non-technical $12
2. Junior Hydrogeologist/Geologist $17
3. Mid-Level Hydrogeologist/Modeler $30
4. Senior Hydrogeologist/Modeler $35
Potential Overhead Costs include those for equipment to collect hydrogeologic data, computer hardware and software, and the costs associated
with report preparation. These figures do not reflect the costs for consulting firms potentially engaged in this work.
Source: Adapted from U.S. EPA, 1987.
37
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Arbitrary Fixed Radius
This approach to wellhead protection involves drawing a
circle of specified radius around each well in your com-
munity to delineate the wellhead protection areas (see
Figure 4-10). For example, several communities in Geor-
gia have selected a radius of 1,500 feet around each well;
the state of Louisiana uses a 1-mile radius for confined
aquifers and a 2-mile radius for unconfined aquifers. The
radius length should reflect the hydrogeology of the area.
Using an arbitrary fixed radius is an inexpensive, easily
implemented method of wellhead delineation that re-
quires little technical expertise (see Table 4-2). Choosing
large fixed radii can increase this method's protective
effectiveness and compensate somewhat for its technical
limitations. Many wells can be protected quickly using this
approach. It can be viewed as a temporary measure until
a more sophisticated delineation method can be used. It
can be especially useful if an imminent contamination
threat exists that demands immediate attention.
The disadvantages of this method include the fact that it
is not based on hydrogeologic principles and that there
may be insufficient information available to choose an
appropriate threshold radius. Therefore, this method
might lead to inadequate protection of recharge areas.
Alternatively, it could lead to overcompensation and in-
creased costs of land management in areas that do not
require it—especially in regions exhibiting complex geol-
ogy where significant hydrologic boundaries are present.
In addition, the limited scientific basis for establishing
these wellhead protection areas might make them less
defensible if challenged later.
Looking at potential contaminant sources near the well-
head protection area established with this method, as well
as those inside the circle, can help you determine whether
a more complex method might be needed.
Calculated Fixed Radius4
This delineation approach involves drawing a circular
boundary around a well for a specified time of travel (see
Chapter Two). Figure 4-11 illustrates the use of the cal-
culated fixed radius method. In this method, Equation 4-1
is used to calculate the required radius of protection for
the well. This equation is based on the volume of water
that could be pumped from a well in a specified time
period. The time period is chosen by estimating the time
necessary to clean up ground water contamination before
it reaches a well, or to allow adequate dilution or disper-
sion of contaminants (e.g., 5 years).
Equation 4-1:
Where:
4This method is used mainly for delineating wellhead protection areas
for confined aquifers. See Appendix C for more information about con-
fined aquifers.
Rate~of Weir(ft3"peryeafy
n = Aquifer Porosity (percent)
H = Open Interval or Length of Well Screen (feet)
t = Travel Time to Well (years) — chosen based on
hydrology and contaminant source locations.
7t = 3.1416
As seen above, the input to Equation 4-1 consists of basic
hydrologic parameters. The advantages of this form of
delineation include its ease of application, low cost, and
relatively limited need for technical expertise. As with the
arbitrary fixed radius method, a large number of wells can
be delineated in a relatively short time frame. Although
the calculated fixed radius method does offer greater sci-
entific accuracy than the arbitrary fixed radius method,
AN EXAMPLE OF WELLHEAD PROTEC-
TION AREA DELINEATION USING THE
CALCULATED FIXED RADIUS APPROACH
; * '
A rural village is located over a confined aquifer. The
village well pumps steadily at 500 gallons per minute
(gpm) and the length of the well screen is 100 feet. Avail-
able literature sources cite aquifer porosity as 0.25 as
measured from aquifer samples. Choosing a travel time
of 5 years the wellhead protection area for the village well
can be determined as follows:
(1)Q = 500 gpm
n = 0.25
H= 100ft
t = 5 yrs
t = 3.1416
(2)
1 gpm = 2.23 xlO
Q = [(500X2.23 x 10-3)(86400 sec/day)
(365 daysfyr)] ft3/yr
Q = 3.52x107ft3/yr
(3) r = V(Qt)/(7tnH)
V(3.52x107ffV)(5yrs)
(3.1416) (0.25) (100 ft)
r=V2.24x106ft2
r = 1500 ft
The village uses a circle of 1500-ft radius to delineate
a wellhead protection area for its well.
38
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Figure 4-10. Wellhead protection area delineation using the arbitrary fixed radius method.
Wellhead
Protection
Area
Land Surface
Pumping
Well
Radius (r) is calculated using a simple equa-
tion that incorporates well pumping rate (Q)
and basic hydrogeologic parameters.
The radius determines a volume of water
that would be pumped from well in a speci-
fied time period.
H = open interval or length of well screen.
Figure 4-11. Wellhead protection area delineation using the calculated fixed radius method. (U.S. EPA, 1991 a).
39
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some results may be inaccurate because this technique
does not consider all factors influencing contaminant
transport. Again, tnis limitation is of special concern in
regions of geologic complexity where hydrologic bounda-
ries exist.
Although this method is relatively inexpensive, it may cost
more than the arbitrary fixed radius method because of
the amount of time needed to establish the hydrogeologic
parameters required to solve Equation 4-1 (see Table
4-2).
Variable Shapes
This method involves the use of analytical models to
produce "standardized forms" of wellhead protection ar-
eas using the representative hydrogeological criteria, time
of travel (TOT), and flow boundaries (locations of physical
or hydrologic features controlling ground water flow). Vari-
ous standardized forms are calculated for different sets
of hydrogeologic conditions. Many shapes are possible
for each set of conditions; however, this methodology
chooses a few generalized forms. The most suitable form
is chosen for each well by determining how closely that
form matches the hydrogeologic and pumping conditions
exhibited at the wellhead. Once the appropriate stand-
ardized form has been identified, it must be correctly
aligned around the wellhead based on the direction of
ground water flow (see Figure 4-12). The upgradient ex-
tent of the wellhead protection area is determined by
using a TOT equation and the well's zone of contribution
(the entire area that recharges or contributes water to the
well), including the distance downgradient. The down-
gradient ground water flow boundaries are calculated us-
ing the uniform flow equation (see Figure 4-13).
The advantages of using variable shapes lie in the fact
that this method requires little actual field data and can
be easily implemented once the standardized forms have
been calculated. It offers a more comprehensive technical
delineation than the fixed-radius method with only a minor
increase in cost. Once the standardized forms are devel-
oped, the only necessary information required is well
pumping rate, material type, and the direction of ground
water flow (U.S. EPA, 1987).
The disadvantages of this methodology include the po-
tential for inaccuracies in areas with many geologic
changes and hydrologic boundaries. In addition, a large
amount of data collection is essential to develop the
shapes of the standardized forms accurately and to char-
acterize ground water flow patterns in the locus of the
wellheads adequately. At a simple level, this method is
more well-specific than the arbitrary or calculated fixed
radius methods, but its results can be skewed by small
errors in information.
Analytical Models
Analytical methods involve the use of equations to deline-
ate the boundaries of wellhead protection areas. These
are extremely useful tools for understanding ground water
flow networks and contaminant transportation systems.
The uniform flow equations (Todd, 1980) are used to
define the zone of contribution to a pumping well in a
sloping water table (see Figure 4-13). These equations
also define ground water flow within an aquifer.
Specific hydrogeologic input data are required to satisfy
these equations at each well where this method is imple-
mented. These data can include hydraulic conductivity,
transmissivity, hydraulic gradient, pumping rate, and
thickness of the saturated zone (see Chapter Two and
Appendix E for definitions). Once this information has
been obtained, the equations can be used to define spe-
cific features of the wellhead protection area, such as the
distance to the downgradient divide (stagnation point) and
the appropriate zone of contribution. The upgradient
boundaries of the wellhead protection area are based on
flow boundaries or TOT threshold values.
This method is relatively inexpensive, even though con-
sultants may be involved, and is one of the most exten-
sively used methods for delineating wellhead protection
areas. Costs may escalate if site-specific hydrogeologic
data are not readily available and test holes must be
drilled or pump tests must be performed.
This technique can be used to determine distances that
define the zone of contribution for a well pumping in a
sloping water table, but it generally cannot calculate draw-
down (lowering of water level in well due to pumping)
which determines the well's zone of influence (cone of
depression). Additionally, analytical methods generally do
not assimilate geologic heterogeneities and hydro-
geologic boundaries in their modeling. However, comput-
erized analytical flow and contaminant transport models
have been developed. (See Model Assessment for De-
lineating Wellhead Protection Areas [U.S. EPA, 1988] for
an assessment of these models.)
WHPA Code 2.1
WHPA is a modular semianalytical ground water flow
model developed by U.S. EPA's Office of Ground Water
Protection (currently the Office of Ground Water and
Drinking Water) primarily to assist state and local techni-
cal staff with WHPA delineation. It is distributed by the
International Ground Water Modeling Agency (303-273-
3103; contact this agency for the most recent version).
The WHPA model uses a computer program to solve the
analytical equations for two-dimensional flow to a well
under various hydrologic conditions. WHPA can be used
on most personal computers and is very straightforward
to use. The user is prompted, through a series of pop-up
windows, to provide the specific input required.
The WHPA model contains four independent modules:
RESSQC, MWCAP (Multiple Well Capture Zone),
GPTRAC (General Particle Tracking), and MONTEC (Un-
certainty Analysis). These modules compute the zone of
40
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STEP 1
Delineate Standardized Forms for Certain Aquifer Type
Direction of
Ground Water
Flow
> c»2 > 03
Pumping Rate = Qf
Q2
Various standardized forms are generated using analytical equations using sets of
representative hydrogeologic parameters. Upgradient extent of WHPA is calculated with
Time of Travel equation; downgradient with uniform flow equation.
Apply Standardized Form to Wellhead in Aquifer Type
STEP
2
Direction of Ground
Water Flow
WHPA
Standardized form is then applied to wells with similar pumping rate
and hydrogeologic parameters.
Figure 4-12. Wellhead protection area delineation using the simplified variable shapes method (U.S. EPA, 1987).
41
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GROUND
Q ^SURFACE
ORIGINAL
PIEZOMETRIC
SURFACE
DRAWDOWN CURVE
'^PERMEABLE
(a)
CONFINED
AQUIFER
IMPERMEABLE
FLOW
LINES,
y t+XAPumping EQUIPOTENTIAL LINES 6
'•!-* V Well -.
GROUND WATER
DIVIDE
UNIFORM-FLOW
EQUATION
DISTANCE TO
DOWN-GRADIENT DIVIDE
OR STAGNATION POINT
1 Place in ground water flow field at which ground water is not moving.
YL =
2Kb!
BOUNDARY LIMIT
Where:
Q = Well Pumping Rate
K = Hydraulic Conductivity
b = Saturated Thickness
I = Hydraulic Gradient
FIGURE 4-13. WHPA delineation using the uniform flow analytical model (Todd, 1980).
42
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USING ANALYTICAL EQUATIONS F-OH ZONb Uh CONTRIBUTION (ZOC) DELINEATION
The figure below is a regional water-table map showing
the elevation of the water table and other hydrologic features
around the site of a village well in a fractured-rock terrain.
The well is completed in an unconfined aquifer composed of
fractured igneous rock overlain by thin soils. The water table
is in the fractured rock. The municipal well pumps steadily
at 65 gallons per minute (gpm), and is screened over the
entire aquifer thickness of 150 ft. The only information on the
hydraulic properties of the aquifer comes from literature val-
ues from a general study of the county that cites the hydraulic
conductivity of the aquifer as 3 x 10~* ft/sec.
The ZOC for the village well can be calculated using the
uniform flow equation (see Figure 4-13), and estimating the
horizontal hydraulic gradient from the water-table map.
Q = 65 gpm
K = 3x10" ft/sec
7t = 3.1416
b= 150ft
= 2.23x10~3ft3/sec
(2) Hydraulic Gradient
0.0031
(1)
-Q
(27tKbi)
YL =
±Q
(2Kbi)
(3)
(4) YL =
1600ft
-(65)(2.23x10~3)
27t(3x 10^)0 50) (.0031)
±(65)(2.23x10"3)
2(3x10"*)(150) (.0031)
165ft
520ft
Source: K. Bradbury, Wisconsin Geological and Natural History
Survey.
Regional Water Table
Contour interval 5 ft Scale: 1/2 inch = 1000 ft • - Village
contribution of wells based on a range of input data.
Each module operates completely independently of one
another. The input requirements for each module are
shown in Table 4-3. Each module is discussed in detail
in the EPA guidance manual accompanying the WHPA
software.
The WHPA code can be used to model multiple pumping
and injection wells, and can simulate barrier or stream
boundary conditions that exist over the entire aquifer
depth. Confined, leaky-confined, and unconfined aquifers
with areal recharge can be modelled using WHPA.
The advantages of using the WHPA model in wellhead
delineation are that it determines ground water flow paths
and travel times very precisely, incorporates the effects
of well interference, and provides rapid solution of ana-
lytical equations combined with delineation of the zone of
contribution. The disadvantages include the limitation of
solving only two-dimensional flow problems, the danger
43
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Table 4-3. Required Input for WHPA Model Computational Modules
GPTRAC
Semi-
Required Input RESSQC MWCAP analytical Numerical
Units used
Aquifer type* • • • •
Study area limits •
Maximum step length . • • • •
No. of pumping wells • • •
No. of recharge wells • • • •
Well locations • • •
Pumping/injection rates • • • •
Aquifer transmissivity • • • •
Aquifer porosity • • • •
Aquifer thickness • • • •
Angle of ambient flow • • • •
Ambient hydraulic gradient • • •
Areal recharge rate • • •
Confining layer hydraulic conductivity •
Confining layer thickness •
Boundary condition type • •
Perpendicular distance from well to • •
boundary
Orientation of boundary • •
Capture zone type •
No. of pathlines used to delineate • • • •
capture zones
Simulation time • • •
Capture zone time • • • •
Rectangular grid parameters •
No. of forward/reverse pathlines • • •
Starting coordinates for • • •
forward/reverse pathlines
Nodal head values •
No. of heterogeneous aquifer zones •
Heterogeneous aquifer properties •
'Confined, unconfined, or leaky confined.
Note: The MONTEC module is not listed in this table. It has the same input requirements as MWCAP and semi-analytical GPTRAC, with the addition
that uncertain aquifer parameters and their associated probability distributions must be specified.
Source: U.S. EPA, Office of Ground Water Protection. WHPA—A Modular Semi-Analytical Model for the Delineation of Wellhead Protection Areas.
March 1991.
44
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CRITERIA FOR DELINEATION OF WELLHEAD PROTECTION AREAS
The U.S Environmental Protection Agency (1987) has
recommended five criteria as the technical basis for deline-
ating wellhead protection areas. These criteria are:
• Distance
The distance criterion is used to delineate wellhead pro-
tection areas by calculating a fixed radius or other dimen-
sion, measured from the well to the wellhead protection
. area boundary. This approach is the simplest, least expen-
sive, and most direct approach to wellhead delineation. It
is only recommended as a preliminary step, however, be-
cause it does not include the processes of ground water
flow or contaminant transport.
• Drawdown
Drawdown is the decline in water level elevation induced
by a pumping well. The greatest drawdown occurs at the
well and decreases with distance away from the well until
an outer limit is reached where the water level is not
affected by the pumpage. This outer limit is the zone of
influence or the areal extent of the well's cone of depres-
sion. Ground water flow velocities increase toward a
pumping well; therefore, drawdown can increase the flow
of contaminants toward a well. The drawdown criterion
may be used to delineate the boundaries of the zone of
influence and this may be used as a wellhead protection
area.
• Time of Travel (TOT)
The time of travel criterion is used to represent the time it
takes for ground water or a contaminant to flow from a
. point within a well's zone of contribution to a well. Using
this criterion, isochrons (contours of equal time) of se-
lected time periods are delineated on a map. The lateral
area contained within an isochron is referred to as the
zone of transport (ZOT) and this is used as the wellhead
protection area.
• Row Boundaries
The flow boundary criterion uses determined locations of
ground water divides and/or other physical/hydrologic fea-
tures that control ground water flow to define the geo-
graphic area that contributes ground water to a pumping
well. This area is the zone of contribution (ZOC) of the
well and is used as its wellhead protection area. This
approach assumes that contaminants entering the ZOC
will eventually reach a pumping well. Ground water divides
occur naturally or may be artificial, such as those created
by a pumping well. The flow boundaries criterion is espe-
cially useful for small aquifer systems.
• Assimilative Capacity
The assimilative capacity criterion takes into account the
fact that the saturated and/or unsaturated section of an
aquifer can attenuate the toxicity of contaminants before
they reach a pumping well through the processes of dilu-
tion, dispersion, adsorption, and chemical precipitation or
biological degradation. This approach, however, requires
knowledge of sophisticated contaminant transport model-
ing and extensive information on the hydrology, geology,
and geochemistry of the study area. Therefore, this ap-
proach is unrealistic for limited studies.
of hidden errors due to the simplicity of operation, and
the assumptions in certain modules that the aquifer is
homogeneous and isotropic (having properties that are
the same in all directions). These assumptions could be
very unrealistic.
Hydrogeologic Mapping
This method utilizes geological, geomorphic, geophysical,
and dye tracing methods to map flow boundaries and time
of travel criteria. To determine the appropriate flow
boundaries, geological studies of the aquifer are under-
taken to identify varying rock characteristics which indi-
cate permeable and non-permeable rock material.
Geophysical investigations can also determine the aerial
extent and thickness of unconfined aquifers. Ground
water drainage divides also can be used in hydrogeologic
mapping (U.S. EPA, 1987). Figure 4-14 illustrates the use
of geologic contacts and ground water divides in wellhead
protection area delineation.
This method can be used to delineate wellhead protection
areas for conduit karst aquifers (see Chapter Two), which
exhibit high flow rates and are rapidly recharged due to
their channel-like structure (karst is a region charac-
terized by rock dissolution). The wellhead protection area
can be delineated first by developing catchment area
(drainage divides) mapping and water table mapping, and
second by conducting dye-tracing testing to produce
more accurate mapping of the karst recharge patterns.
(Dye tracing is essential in karst aquifers because ground
water flow patterns commonly do not follow topographic
divides and can change significantly depending on
whether high- or low-flow conditions exist.) This form of
delineation works well for aquifers whose flow boundaries
are relatively near the surface, as found in glacial and
alluvial aquifers, and for aquifers exhibiting different
physical properties in different directions, as found in frac-
tured bedrock and channelled karst (U.S. EPA, 1987).
This delineation technique requires expertise in the geo-
logical sciences and professional judgment in determining
flow boundaries. This approach may prove expensive if
little hydrogeologic data exist and field investigations are
necessary. Great care must be taken if extrapolated data
are used.
Numerical Models
This method utilizes computer modeling techniques to
simulate the three-dimensional boundaries of an aquifer
using numerical equations. Much of the current emphasis
45
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WELLHEAD PROTECTION
AREA
LAND SURFACE
STREAM
VALLEY
WELLHEAD
DRAWDOWN
GROUND WATER
DIVIDE
PROTECTION AREA
CONTOURS
LEGEND
£ Water Table
• Pumping Well
— Ground Water Divide
NS*^ Direction of Ground Water Flow
fe&fl Wellhead Protection Area
Figure 4-14. Wellhead protection area delineation using hydrogeologic mapping (use of ground water divides). (U.S. EPA,
1987).
46
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ADVANTAGES AND DISADVANTAGES OF
WELLHEAD PROTECTION AREA
DELINEATION TECHNIQUES
Karst aquifers exhibit high flow rates and are rapidly re-
charged due to their channel-like structure.
in this field lies in mathematical flow models and contami-
nant transport models. Flow models are used to calculate
changes in the distribution of hydraulic head of fluid pres-
sure, drawdowns, rate and direction of flow, travel times,
and the position of interfaces between immiscible fluids,
while solute transport and fate models predict movement,
concentrations, and mass balance components of water
soluble constituents (U.S. EPA, 1988).
In general, the numerical approach requires the formula-
tion of a grid that simulates the test aquifer. At each node,
values such as water table elevation, hydraulic conduc-
tivity, and aquifer thickness are input. These form the
basis for a matrix of equations that simulate the aquifer.
The model can simulate changes in any of the hydrologic
conditions characterizing the aquifer to investigate the
effects of such alterations.
The main advantage of these computer models is their
ability to model aquifers exhibiting complex hydrogeology.
This requires a significant amount of field information
because the data input usually covers a wide range of
hydrogeologic parameters. A major advantage of com-
puter modeling is the rate at which computers can syn-
thesize and manipulate large amounts of analytical data.
An additional advantage is the predictive nature of mod-
eling techniques, which allows the user to determine the
system's response to a variety of proposed management
options. In addition to these useful predictions, these
models provide a high degree of accuracy.
Because computer and hydrogeological expertise is
needed to produce these models, this method can be
costly. As shown in Table 4-1, it has the potential to be
the most expensive of all the delineation methods dis-
cussed here. If a high degree of accuracy is demanded,
however, this methodology can prove cost-effective, es-
pecially if a large, detailed data base is available from
which to work. For a more extensive discussion of nu-
Arbitrary fixed
radius
Little data necessary
Quick and easy to draw
Very low cost
Not very accurate
Calculated fixed Need limited hydrogeologic data
radius Relatively quick and easy
Inexpensive
Not highly accurate
Variable shapes Based on relatively little field data
Still fairly quick and easy
If data are available, low cost
In complex settings, not very precise
WHPA Code Based on substantial field data ;
(Semianalytic May require technical assistance
model) Automatic delineation of capture zones
Calculates the effects of well
interference
Danger of hidden errors because the
program is simple to operate
Most solutions assume homogeneous
isotropic aquifers
Moderate costs
Analytic Based oh substantial field data
models Probably requires professional help
Moderate costs, if data are available
Widely used, fairly accurate
Numerical Based on extensive field data
models Requires computer/technical expertise
Can be highly accurate
Can be quite expensive
Source: Adapted from Paley and Steppacher, n.d.
merical modeling techniques, see Model Assessment for
Delineating Wellhead Protection Areas (U.S. EPA, 1988).
Hiring a Consultant
Mapping wellhead protection areas might require techni-
cal expertise in the science of hydrogeology, depending
on the complexity of your community's aquifer. If you
cannot obtain sufficient help from a state or federal gov-
ernment agency, your team can consider hiring a hydro-
geologist, engineer, and/or land planner as a technical
adviser. Selecting a consulting engineering firm to under-
take a hydrogeologic study requires careful judgment; the
firm's services can be expensive and the delineated
boundaries of your resource area could be challenged in
court at a later date. The steps involved in choosing an
engineering consulting firm include identifying potential
47
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candidate firms, issuing a request for proposals, inter-
viewing, checking references, and preparing a contract
once a consultant has been selected.
Potential candidates can be easily identified by your com-
munity's past experience, or by contacting your local ex-
tension service, the National Rural Water Association, a
rural community assistance program, or state ground
water agency. These organizations might also be able to
offer you technical support. The National Ground Water
Association, the American Institute of Professional Geolo-
gists, the National Society of Professional Engineers, and
the American Academy of Environmental Engineers are
good sources for consultant information.
A request for proposals will differ for every community,
depending on its size and the nature of your project. This
document should be as specific as possible and should,
at a minimum, describe the major goal of the project, the
anticipated scope of work, and the final product(s) re-
quired (such as reports, ground water mapping, geologic
mapping, delineated wellhead protection areas, zoning
map overlay, and analysis of future needs). It should con-
tain a request for information on personnel qualifications
and experience, and should include the standards by
which the proposals will be judged. The deadline for pro-
posals and the local contact person also should be noted.
Three or four firms should be selected from those that
meet your judging standards. During the interviewing
stages, the wellhead protection planning team should
compare the professional reputation of each firm, its ex-
perience in similar projects, including facilities and equip-
ment capabilities, project cost and billing policy,
understanding of the nature of the project, and the poten-
tial quality of the finished product. The final selection
should be the result of a consensus of the team on who
will do the best job for your community. Once a firm is
chosen, a contract must be prepared and submitted to
local policy makers for approval. The firm's original pro-
posal should be included in this contract.
The planning team should closely monitor and keep up
to date with its consultant's progress. The public should
be informed of this progress regularly.
STEP THREE—Identify and Locate
Potential Sources of Contamination
This step serves two purposes: providing your team with
information about existing and potential sources of
ground water contamination and helping your team begin
the process of land management that will ultimately pro-
tect your ground water supply.
Divide the Wellhead Protection Area into
Different Land-Use Categories
The first stage in identifying potential contaminant
sources is the preparation of a land use overlay map for
your wellhead protection area. This map will help your
team establish the threat that land uses pose to the qual-
ity of your water supply. A good starting point for this map
is your community's zoning map (see Figure 4-6) or cur-
rent land use map, which allocates sections of your com-
munity for specific land uses, including residential,
commercial, and industrial uses. These zones create con-
centrations of businesses; if these concentrations are lo-
cated in the recharge zone of your aquifer, they can
increase the threat to your resource. Many industries are
built along transportation corridors that follow river val-
leys, where high-yield aquifers are often located. Your
team might discover that your community has been inap-
propriately zoned and does not limit high-risk activities
within your aquifer's primary recharge zone. At this stage,
your team might also find the aerial photographs that you
collected in Step One to be very useful.
An important part of preparing your overlay map is iden-
tifying past and present waste disposal sites. These dis-
posal sites might be easily recognizable as sewage
treatment works, landfills, or underground injection wells,
but care must be taken also to locate small commercial
and industrial waste areas, such as lagoons and drywells.
Residential underground septic systems also should be
included on the map. The waste materials discharged at
these sites can include solid waste, sludge, liquids, sol-
vents, and oils. Your team should also establish whether
any of the wastes discharged in your community are haz-
ardous under the Resource Conservation and Recovery
Act (RCRA). Information about industrial disposal facili-
ties can be obtained from state and federal water pollution
control agencies.
When identifying land uses, it is important to consider not
only existing uses but also the historical and intended
uses of the land. The historical uses (such as capped
landfills, underground fuel storage facilities, abandoned
mines, or tanneries) often play a major role in the land's
present capacity to contaminate an aquifer. For example,
land that was used for agricultural purposes at one stage
should be researched to identify chemicals such as
pesticides used, stored, or disposed of on site. Searching
records and/or interviewing long-time residents will help
ensure that you do not overlook past sources of
contamination.
Review Potential Sources of Contamination
To identify potential sources of contamination adequately,
it is useful to prepare a comprehensive inventory. Your
team can list contaminant sources according to land use
or type of source. (Table 3-1 lists some contaminant
sources by land use category. Table 4-4 will help your
team consider the contaminants that might be associated
with various sources.) The inventory will prevent omission
of any potential contaminant source, while making your
team's management strategy easier to handle. Figure 4-15
48
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Table 4-4. Potential Sources of Ground Water Contamination
Source Health, Environmental, or Aesthetic Contaminant1'2'3
NATURALLY OCCURRING SOURCES
Rocks and soils
Contaminated water
Decaying organic matter
Geological radioactive gas
Natural hydrogeological events and
formations
AGRICULTURAL SOURCES
Animal feedlots and burial areas
Manure spreading areas and
storage pits
Livestock waste disposal areas
Crop areas and irrigation sites
Chemical storage areas and
containers
Farm machinery areas
Agricultural drainage wells and
canals
RESIDENTIAL SOURCES
Common household maintenance
and hobbies
Lawns and gardens
Swimming pools
Septic systems, cesspools, and
sewer lines
Underground storage tanks
Apartments and condominiums
Aesthetic Contaminants: Iron and iron bacteria; manganese; calcium and magnesium
(hardness)
Health and Environmental Contaminants: Arsenic; asbestos; metals; chlorides;
fluorides; sulfates; sulfate-reducing bacteria and other microorganisms
Excessive sodium; bacteria; viruses; low pH (acid) water
Bacteria
Radionuclides (radon, etc.)
Salt-water/brackish water intrusion (or intrusion of other poor quality water);
contamination by a variety of substances through sink-hole infiltration in limestone
terrains
Livestock sewage wastes; nitrates; phosphates; chloride; chemical sprays and dips for
controlling insect, bacterial, viral, and fungal pests on livestock; coliform4 and
noncoliform bacteria; viruses
Livestock sewage wastes; nitrates
Livestock sewage wastes; nitrates
Pesticides;5 fertilizers;6 gasoline and motor oils from chemical applicators
Pesticide5 and fertilizer6 residues
Automotive wastes;7 welding wastes
Pesticides;5 fertilizers;6 bacteria; salt water (in areas where the fresh-saltwater
interface lies at shallow depths and where the water table is lowered by
channelization, pumping, or other causes)
Common Household Products? Household cleaners; oven cleaners; drain cleaners;
toilet cleaners; disinfectants; metal polishes; jewelry cleaners; shoe polishes; synthetic
detergents; bleach; laundry soil and stain removers; spot removers and dry cleaning
fluid; solvents; lye or caustic soda; household pesticides;9 photochemicals; printing ink;
other common products
Wall and Furniture Treatments: Paints; varnishes; stains; dyes; wood preservatives
(creosote); paint and lacquer thinners; paint and varnish removers and deglossers;
paint brush cleaners; floor and furniture strippers
Mechanical Repair and Other Maintenance Products: Automotive wastes;7 waste oils;
diesel fuel; kerosene; #2 heating oil; grease; degreasers for driveways and garages;
metal degreasers; asphalt and roofing tar; tar removers; lubricants; rustproofers; car
wash detergents; car waxes and polishes; rock salt; refrigerants
Fertilizers;5 herbicides and other pesticides used for lawn and garden maintenance10
Swimming pool maintenance chemicals11
Septage; coliform and noncoliform bacteria;4 viruses; nitrates; heavy metals; synthetic
detergents; cooking and motor oils; bleach; pesticides;9'10 paints; paint thinner;
photographic chemicals; swimming pool chemicals;11 septic tank/cesspool cleaner
chemicals;12 elevated levels of chloride, sulfate, calcium, magnesium, potassium, and
phosphate
Home heating oil
Swimming pool maintenance chemicals;11 pesticides for lawn and garden maintenance
and cockroach, termite, ant, rodent, and other pest control;9'10 wastes from onsite
sewage treatment plants; household hazardous wastes8
49
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Table 4-4. Potential Sources of Ground Water Contamination (continued)
Source Health, Environmental, or Aesthetic Contaminant123
MUNICIPAL SOURCES
Schools and government offices and
grounds
Park lands
Public and residential areas infested
with mosquitoes, gypsy moths, ticks,
ants, or other pests
Highways, road maintenance depots,
and deicing operations
Municipal sewage treatment plants
and sewer lines
Storage, treatment, and disposal
ponds, lagoons, and other surface
impoundments
Land areas applied with wastewater
or wastewater byproducts
Storm water drains and basins
Combined sewer overflows (munici-
pal sewers and storm water drains)
Recycling/reduction facilities
Municipal waste landfills
Open dumping and burning sites,
closed dumps
Municipal incinerators
Water supply wells, monitoring wells,
older wells, domestic and livestock
wells, unsealed and abandoned
wells, and test hole wells
Sumps and dry wells
Drainage wells
Well pumping that causes inter-
aquifer leakage, induced filtration,
landward migration of sea water in
coastal areas; etc.
Artificial ground water recharge
COMMERCIAL SOURCES
Airports, abandoned airfields
Auto repair shops
Barber and beauty shops
Boat yards and marinas
Solvents; pesticides;9'10 acids; alkalis; waste oils; machinery/vehicle servicing wastes;
gasoline and heating oil from storage tanks; general building wastes13
Fertilizers;6 herbicides;10 insecticides9
Pesticides5'9
Herbicides in highway rights-of-way;5|1° road salt (sodium and calcium chloride); road
salt anticaking additives (ferric ferrocyanide, sodium ferrocyanide); road salt
anticorrosives (phosphate and chromate); automotive wastes7
Municipal wastewater; sludge;14 treatment chemicals15
Sewage wastewater; nitrates; other liquid wastes; microbiological contaminants
Organic matter; nitrate; inorganic salts; heavy metals; coliform and noncoliform
bacteria;4 viruses; nitrates; sludge;14 nonhazardous wastes16
Urban runoff; gasoline; oil; other petroleum products; road salt; microbiological
contaminants
Municipal wastewater; sludge;14 treatment chemicals;15 urban runoff; gasoline; oil;
other petroleum products; road salt; microbial contaminants
Residential and commercial solid waste residues
Leachate; organic and inorganic chemical contaminants; wastes from households8 and
businesses, nitrates; oils; metals
Organic and inorganic chemicals; metals; oils; wastes from households8 and
businesses13
Heavy metals; hydrocarbons; formaldehyde; methane; ethane; ethylene; acetylene;
sulfur and nitrogen compounds
Surface runoff; effluents from barnyards, feedlots, septic tanks, or cesspools;
gasoline; used motor oil; road salt
Storm water runoff; spilled liquids; used oil; antifreeze; gasoline; other petroleum
products; road salt; pesticides;5 and a wide variety of other substances
Pesticides;9'10 bacteria
Saltwater; excessively mineralized water
Storm water runoff; excess irrigation water; stream flow; cooling water; treated sewage
effluent; other substances that may contain contaminants, such as nitrates, metals,
detergents, synthetic organic compounds, bacteria, and viruses
Jet fuels; deicers; diesel fuel; chlorinated solvents; automotive wastes;7 heating oil;
building wastes13
Waste oils; solvents; acids; paints; automotive wastes;7 miscellaneous cutting oils
Perm solutions; dyes; miscellaneous chemicals contained in hair rinses
Diesel fuels; oil; septage from boat waste disposal areas; wood preservative and
treatment chemicals; paints; waxes; varnishes; automotive wastes7
50
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Table 4-4. Potential Sources of Ground Water Contamination (continued)
Source Health, Environmental, or Aesthetic Contaminant1'2'3
Bowling alleys
Car dealerships (especially those
with service departments)
Car washes
Camp grounds
Carpet stores
Cemeteries
Construction trade areas and materi-
als (plumbing, heating and air condi-
tioning, painting, paper hanging,
decorating, drywall and plastering,
acoustical insulation, carpentry, floor-
ing, roofing and sheet metal, wreck-
ing and demolition, etc.)
Country clubs
Dry cleaners
Funeral services and crematories
Furniture repair and finishing shops
Gasoline services stations
Golf courses
Hardware/lumber/parts stores
Heating oil companies, underground
storage tanks
Horticultural practices, garden
nurseries, florists
Jewelry/metal plating shops
Laundromats
Medical institutions
Office buildings and office complexes
Paint stores
Pharmacies
Photography shops, photo process-
ing laboratories
Print shops
Railroad tracks and yards
Research laboratories
Epoxy; urethane-based floor finish
Automotive wastes;7 waste oils; solvents; miscellaneous wastes
Soaps; detergents; waxes; miscellaneous chemicals
Septage; gasoline; diesel fuel from boats; pesticides for controlling mosquitoes, ants,
ticks, gypsy moths, and other pests;5'9 household hazardous wastes from recreational
vehicles (RVs)8
Glues and other adhesives; fuel from storage tanks if forklifts are used
Leachate; lawn and garden maintenance chemicals10
Solvents; asbestos; paints; glues and other adhesives; waste insulation; lacquers; tars;
sealants; epoxy waste; miscellaneous chemical wastes
Fertilizers;6 herbicides;5'10 pesticides for controlling mosquitoes, ticks, ants, gypsy
moths, and other pests;9 swimming pool chemicals;11 automotive wastes
Solvents (perchloroethylene, petroleum solvents, Freon); spotting chemicals
(trichloroethane, methylchloroform, ammonia, peroxides, hydrochloric acid, rust
removers, amyl acetate)
Formaldehyde; wetting agents; fumigants; solvents
Paints; solvents; degreasing and solvent recovery sludges
Oils; solvents; miscellaneous wastes
Fertilizers;6 herbicides;5'10 pesticides for controlling mosquitoes, ticks, ants, gypsy
moths, and other pests9
Hazardous chemical products in inventories; heating oil and fork lift fuel from storage
tanks; wood-staining and treating products such as creosote
Heating oil; wastes from truck maintenance areas7
Herbicides, insecticides, fungicides, and other pesticides10
Sodium and hydrogen cyanide; metallic salts; hydrochloric acid; sulfuric acid; chromic
acid
Detergents; bleaches; fabric dyes
X-ray developers and fixers;17 infectious wastes; radiological wastes; biological
wastes; disinfectants; asbestos; beryllium; dental acids; miscellaneous chemicals
Building wastes;13 lawn and garden maintenance chemicals;10 gasoline; motor oil
Paints; paint thinners; lacquers; varnishes; other wood treatments
Spilled and returned products
Biosludges; silver sludges; cyanides; miscellaneous sludges
Solvents; inks; dyes; oils; photographic chemicals
Diesel fuel; herbicides for rights-of-way; creosote for preserving wood ties
X-ray developers and fixers;17 infectious wastes; radiological wastes; biological
wastes; disinfectants; asbestos; beryllium; solvents; infectious materials; drugs;
disinfectants (quaternary ammonia, hexachlorophene, peroxides, chlornexade, bleach);
miscellaneous chemicals
51
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Table 4-4. Potential Sources of Ground Water Contamination (continued)
Source Health, Environmental, or Aesthetic Contaminant1'2'3
COMMERCIAL SOURCES (continued)
Scrap and junk yards
Sports and hobby shops
Above-ground and underground stor-
age tanks
Transportation services for passen-
ger transit (local and interurban)
Veterinary services
INDUSTRIAL SOURCES
Material stockpiles (coal, metallic
ores, phosphates, gypsum)
Waste tailing ponds (commonly for
the disposal of mining wastes)
Any wastes from businesses13 and households;8 oils
Gunpowder and ammunition; rocket engine fuel; model airplane glue
Heating oil; diesel fuel; gasoline; other petroleum products; other commercially used
chemicals
Waste oil; solvents; gasoline and diesel fuel from vehicles and storage tanks; fuel oil;
other automotive wastes7
Solvents; infectious materials; vaccines; drugs; disinfectants (quaternary
ammonia, hexachlorophene, peroxides, chlornexade, bleach); x-ray developers
and fixers17
Acid drainage; other hazardous and nonhazardous wastes
16
Acids; metals; dissolved solids; radioactive ores; other hazardous and nonhazardous
wastes
15
Transport and transfer stations (truck- Fuel tanks; repair shop wastes;7 other hazardous and nonhazardous wastes15
ing terminals and rail yards)
Above-ground and underground
storage tanks and containers
Storage, treatment, and disposal
ponds, lagoons, and other surface
impoundments
Chemical landfills
Radioactive waste disposal sites
Unattended wet and dry excavation
sites (unregulated dumps)
Operating and abandoned produc-
tion and exploratory wells (for gas,
oil, coal, geothermal, and heat re-
covery); test hole wells; monitoring
and excavation wells
Dry wells
Injection wells
Well drilling operations
Heating oil; diesel and gasoline fuel; other petroleum products; hazardous and
nonhazardous materials and wastes16
Hazardous and nonhazardous liquid wastes;16 septage; sludge14
Leachate; hazardous and nonhazardous wastes;16 nitrates
Radioactive wastes from medical facilities, power plants, and defense operations;
radionuclides (uranium, plutonium)
A wide range of substances; solid and liquid wastes; oil-field brines; spent acids from
steel mill operations; snow removal piles containing large amounts of salt
Metals; acids; minerals; sulfides; other hazardous and nonhazardous chemicals16
Saline water from wells pumped to keep them dry
Highly toxic wastes; hazardous and nonhazardous industrial wastes;16 oil-field brines
Brines associated with oil and gas operations
INDUSTRIAL PROCESSES (PRESENTLY OPERATED OR TORN-DOWN FACILITIES)18
Asphalt plants
Communications equipment
manufacturers
Electric and electronic equipment
manufacturers and storage facilities
Electroplaters
Foundries and metal fabricators
Petroleum derivatives
Nitric, hydrochloric, and sulfuric acid wastes; heavy metal sludges; copper-
contaminated etchant (e.g., ammonium persulfate); cutting oil and degreasing solvent
(trichloroethane, Freon, or trichloroethylene); waste oils; corrosive soldering flux; paint
sludge; waste plating solution
Cyanides; metal sludges; caustics (chromic acid); solvents; oils; alkalis; acids; paints
and paint sludges; calcium fluoride sludges; methylene chloride; perchloroethylene;
trichloroethane; acetone; methanol; toluene; PCBs
Boric, hydrochloric, hydrofluoric, and sulfuric acids; sodium and potassium hydroxide;
chromic acid; sodium and hydrogen cyanide; metallic salts
Paint wastes; acids; heavy metals; metal sludges; plating wastes; oils; solvents;
explosive wastes
52
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Table 4-4. Potential Sources of Ground Water Contamination (continued)
Source Health, Environmental, or Aesthetic Contaminant123
Furniture and fixtures manufacturers
Machine and metalworking shops
Mining operations (surface and
underground), underground storage
mines
Unsealed abandoned mines used as
waste pits
Paper mills
Petroleum production and storage
companies, secondary recovery of
petroleum
Industrial pipelines
Photo processing laboratories
Plastics materials and synthetics
producers
Primary metal industries (blast fur-
naces, steel works, and rolling mills)
Publishers, printers, and allied
industries
Public utilities (phone, electric power,
gas)
Sawmills and planers
Stone, clay, and glass manufacturers
Welders
Wood preserving facilities
Paints; solvents; degreasing sludges; solvent recovery sludges
Solvents; metals; miscellaneous organ ics; sludges; oily metal shavings; lubricant and
cutting oils; degreasers (tetrachlorethylene); metal marking fluids; mold-release agents
Mine spoils or tailings that often contain metals; acids; highly corrosive mineralized
waters; metal sulfides
Metals; acids; minerals; sulfides; other hazardous and nonhazardous chemicals16
Metals; acids; minerals; sulfides; other hazardous and nonhazardous chemicals116
organic sludges; sodium hydroxide; chlorine; hypochlorite; chlorine dioxide; hydrogen
peroxide
Hydrocarbons; oil-field brines (highly mineralized salt solutions)
Corrosive fluids; hydrocarbons; other hazardous and nonhazardous materials and
wastes16
Cyanides; biosludges; silver sludges; miscellaneous sludges
Solvents; oils; miscellaneous organics and inorganics (phenols, resins); paint wastes;
cyanides; acids; alkalis; wastewater treatment sludges; cellulose esters; surfactant;
glycols; phenols; formaldehyde; peroxides; etc.
Heavy metal wastewater treatment sludge; pickling liquor; waste oil; ammonia
scrubber liquor; acid tar sludge; alkaline cleaners; degreasing solvents; slag; metal
dust
Solvents; inks; dyes; oils; miscellaneous organics; photographic chemicals
PCBs from transformers and capacitors; oils; solvents; sludges; acid solution; metal
plating solutions (chromium, nickel, cadmium); herbicides from utility rights-of-way
Treated wood residue (copper quinolate, mercury, sodium bazide); tanner gas; paint
sludges; solvents; creosote; coating and gluing wastes
Solvents; oils and grease; alkalis; acetic wastes; asbestos; heavy metal sludges;
phenolic solids or sludges; metal-finishing sludge
Oxygen, acetylene
Wood preservatives; creosote
11n general, ground water contamination stems from the misuse and improper disposal of liquid and solid wastes; the illegal dumping or abandonment
of household, commercial, or industrial chemicals; the accidental spilling of chemicals from trucks, railways, aircraft, handling facilities, and storage
tanks; or the improper siting, design, construction, operation, or maintenance of agricultural, residential, municipal, commercial, and industrial drinking
water wells and liquid and solid waste disposal facilities. Contaminants also can stem from atmospheric pollutants, such as airborne sulfur and
nitrogen compounds, which are created by smoke, flue dust, aerosols, and automobile emissions, fall as acid rain, and percolate through the soil.
When the sources listed in this table are used and managed properly, ground water contamination is not likely to occur.
Contaminants can reach ground water from activities occurring on the land surface, such as industrial waste storage; from sources below the land
surface but above the water table, such as septic systems; from structures beneath the water table, such as wells; or from contaminated recharge
water.
3This table lists the most common wastes, but not all potential wastes. For example, it is not possible to list all potential contaminants contained
in storm water runoff or research laboratory wastes.
*Coliform bacteria can indicate the presence of pathogenic (disease-causing) microorganisms that may be transmitted in human feces. Diseases
such as typhoid fever, hepatitis, diarrhea, and dysentery can result from sewage contamination of water supplies.
5Pesticides include herbicides, insecticides, rodenticides, fungicides, and avicides. EPA has registered approximately 50,000 different pesticide
products for use in the United States. Many are highly toxic and quite mobile in the subsurface. An EPA survey found that the most common
pesticides found in drinking water wells were DCPA (dacthal) and atrazine, which EPA classifies as moderately toxic (class 3) and slightly toxic
(class 4) materials, respectively.
6The EPA National Pesticides Survey found that the use of fertilizers correlates to nitrate contamination of ground water supplies.
53
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Automotive wastes can include gasoline; antifreeze; automatic transmission fluid; battery acid; engine and radiator flushes; engine and metal
degreasers; hydraulic (brake) fluid; and motor oils.
"Toxic or hazardous components of common household products are noted in Table 3-2.
'Common household pesticides for controlling pests such as ants, termites, bees, wasps, flies, cockroaches, silverfish, mites, ticks, fleas, worms,
rats, and mice can contain active ingredients including napthalene, phosphorus, xylene, chloroform, heavy metals, chlorinated hydrocarbons, arsenic,
strychnine, kerosene, nitrosamines, and dioxin.
"Common pesticides used for lawn and garden maintenance (i.e., weed killers, and mite, grub, and aphid controls) include such chemicals as
2,4-D; chlorpyrifos; diazinon; benomyl; captan; dicofol; and methoxychlor.
"Swimming pool chemicals can contain free and combined chlorine; bromine; iodine; mercury-based, copper-based, and quaternary algicides;
cyanuric acid; calcium or sodium hypochlorite; muriatic acid; sodium carbonate.
"Septic tank/cesspool cleaners include synthetic organic chemicals such as 1,1,1 trichloroethane, tetrachloroethylene, carbon tetrachloride, and
methylene chloride.
"Common wastes from public and commercial buildings include automotive wastes; rock salt; and residues from cleaning products that may contain
chemicals such as xylenols, glycol esters, isopropanol, 1,1,1-trichloroethane, sulfonates, chlorinated phenolys, and cresols.
"Municipal wastewater treatment sludge can contain organic matter; nitrates; inorganic salts; heavy metals; coliform and noncoliform bacteria; and
viruses.
15Municipal wastewater treatment chemicals include calcium oxide; alum; activated alum, carbon, and silica; polymers; ion exchange resins; sodium
hydroxide; chlorine; ozone; and corrosion inhibitors.
"The Resource Conservation and Recovery Act (RCRA) defines a hazardous waste as a solid waste that may cause an increase in mortality or
serious illness or pose a substantial threat to human health and the environment when improperly treated, stored, transported, disposed of, or
otherwise managed. A waste is hazardous if it exhibits characteristics of ignitability, corrosivity, reactivity, and/or toxicity. Not covered by RCRA
regulations are domestic sewage; irrigation waters or industrial discharges allowed by the Clean Water Act; certain nuclear and mining wastes;
household wastes; agricultural wastes (excluding some pesticides); and small quantity hazardous wastes (i.e., less than 220 pounds per month)
generated by businesses.
17X-ray developers and fixers may contain reclaimable silver, glutaldehyde, hydroquinone, phenedone, potassium bromide, sodium sulfite, sodium
carbonate, thiosulfates, and potassium alum.
"This table lists potential ground water contaminants from many common industries, but it does not address all industries.
SOURCES
Cralley, Lewis J. and L.V. Cralley. 1984. Industrial Hygiene Aspects of Plant Operations. MacMillan Publishing Co. New York.
Dadd, Debra. 1986. The Nontoxic Home. Jeremy P. Tarcher, Inc. Los Angeles.
Dadd, Debra. 1984. Nontoxic and Natural. Jeremy P. Tarcher, Inc. Los Angeles.
Horsley and Witten, Inc. 1989. Aquifer Protection Seminar Publication: Tools and Options for Action at the Local Government Level. Barnstable
Village, Massachusetts.
MaoEachern, Diane. 1990. Save Our Planet. Dell Publishing. New York.
Massachusetts Audubon Society. 1987. Road Satt and Ground-Water Protection. Ground-Water Information Flyer #9.
Massachusetts Audubon Society. 1986. Landfills and Ground-Water Protection. Ground-Water Information Flyer #8.
Massachusetts Audubon Society. 1985. Protecting and Maintaining Private Wells. Ground-Water Information Flyer #6.
Massachusetts Audubon Society. 1984. Underground Storage Tanks and Ground-Water Protection. Ground-Water Information Flyer #5.
Meister Publishing Company. Farm Chemicals Handbook, 1991. Willoughby, Ohio.
Metcalf & Eddy. 1989. A Guide to Water Supply Management in the 1990s. Wakefield, MA.
xU.S. Environmental Protection Agency. 1986. Solving the Hazardous Waste Problem: EPA's RCRA Program. EPA Office of Solid Waste.
Washington, D.C. EPA/530-SW-86-037.
U.S. Environmental Protection Agency. 1989. Wellhead Protection Programs: Tools for Local Governments. EPA Office of Water and Office of
Ground-Water Protection.
U.S. Environmental Protection Agency. 1990. Citizen's Guide to Ground-Water Protection. Office of Water, Washington. D.C. EPA 440/6-90-004.
U.S. Environmental Protection Agency. 1990. National Pesticide Survey Project Summary. EPA Office of Water and Office of Pesticides and Toxic
Substances.
U.S. Environmental Protection Agency. 1990. Handbook—Ground Water, Volume I: Ground Water and Contamination. Office of Research and
Development, Washington, D.C. EPA 625/6-90/016a.
U.S. Environmental Protection Agency. 1991. EPA's Pesticide Programs.
U.S. Environmental Protection Agency. 1992. National Pesticide Survey Update and Summary of Phase II Results. EPA Office of Water and Office
of Pesticides and Toxic Substances. EPA/570/9-91-021.
U.S. Environmental Protection Agency, et al. n.d. Companion Workbook for "The Power to Protect."
54
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WELLHEAD PROTECTION AREA
INVENTORY OF POTENTIAL CONTAMINANT SOURCES
DIRECTIONS:
Place a number next to each category that you identify in your wellhead protection area. Place a corresponding
number on a map at the location of the source. Maps that may be used for the inventory include: topography,
zoning, village, city, and utility maps. Please consider ease of photocopying in your selection of a map. If there
is more than one source for a category, label each site with a letter (i.e., 1A, 1B, 1C, 2A, 2B). Record the owner's
name and address of each site on a separate sheet of paper. Please consider all sources within a 1/2-mile radius
of each public water supply well and an assessment within the recharge area(s).
Abandoned Wells
Aboveground Storage Tank
Airport
Animal Feedlot/Waste Storage
Asphalt Plant
Auto Repair/Body Shop/Salvage Washes
Cemetery
Chemical Production/Mixing/Storage
Drainage Canal
Dumps
Electroplaters/Metal Finishers
Fertilizer/Pesticide Storage/
Production/Mixing
Golf Courses/Nurseries
Grain Storage Bin
Holding Pond/Lagoon
I nactive/Abandoned Hazardous Waste Site
Injection Well
Irrigation Practices
Laboratories
Laundromat/Dry Cleaner
Machine Shops
Major Highways and/or Railroads
Military Base/Depot
Mining
Oil/Gas Pipelines
Photo Processors
Printers
Production/Other Wells
Refineries
Refinishing
Road Salt Storage
Septic Systems
Service/Gas Stations
Sewage Plant
Underground Storage Tank
Waste Piles
Wood Preserving
Other (specify)
Figure 4-15. Inventory of potential contaminant sources for a wellhead protection area.
Prepared by Wisconsin Rural Water Association.
55
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presents a form that can be used to take an inventory of
potential contaminant sources in your wellhead protection
area. Your state might have a similar form to help you
inventory potential sources of contamination.
There are many sources of information about potential
contamination sources in your community. These include,
but are not limited to, long-time residents of the commu-
nity; Chamber of Commerce membership lists; the local
phone book; local newspapers; the police and fire depart-
ments; fishermen; the utility companies serving your com-
munity's needs (including electricity supply, water supply,
and waste disposal); community boards such as planning,
conservation, health, engineering, and public works; and
your own visual inspection. Information can also be ob-
tained from state and federal environmental agencies on
the transportation and discharge of hazardous materials,
ground water discharge permitting, and discharges to sur-
face waters. State and federal regulations also mandate
that underground commercial storage tanks be regis-
tered. This information is available from your town hall or
state environmental agency.
It is important that contaminated waters be identified at
this stage of the process. This identification may involve
contacting state water pollution control officials, state
drinking water managers, water companies, and waste
management agencies. The regional health director can
advise you of known contamination problems, but this is
a special opportunity for your team to survey the commu-
nity completely to discover every contamination problem.
Your team should identify the location of any point source
discharges within the community or in any neighboring com-
munities that may affect your wellfield. Point sources dis-
charge waste at a single location and generally consist of
pipe outfalls to surface waters. Examples include sewage
plant outfalls, water treatment plant outfalls, and industrial
users. These discharges are regulated under the federal
Clean Water Act (or a state law where primacy has been
established), which usually requires continuous monitoring
of such discharges. These monitoring logs are an additional
source of water quality information.
Non-point sources are widespread sources of contami-
nation that cumulatively present a threat to ground water.
These sources are not regulated by permits and may be
more difficult to track down. Examples include leakage
from onsite septic systems, combined sewer overflow,
roadway and parking lot drainage, landfill runoff, agricul-
tural runoff, and runoff from stockpiles of roadway deicing
materials, such as salt.
Identify Activities within the Wellhead
Protection Area That Are Potential Sources
of Contamination
In addition to locating actual sources of contamination, it
is important to identify activities within the wellhead pro-
VOLUNTEERS CONDUCT AN INVENTORY OF
CONTAMINANT SOURCES:
THE CITY OF EL PASO, TEXAS
The retired citizens of a community can be an impor-
tant resource to draw upon when it is time to conduct an
inventory of potential contaminant sources in a wellhead
protection area. These individuals often have historical
knowledge of the community, a tradition of local political
involvement, an interest in environmental issues, per-
sonal technical expertise, and free time.
The City of El Paso, Texas, successfully utilized the
talents and energy of retired persons to conduct a source
inventory for its ground water protection pilot project in
1989 and 1990. In November 1989, project officials met
with the El Paso Retired Senior Volunteer Program
(RSVP), which offered to recruit volunteers to conduct an
inventory. (RSVP is a national program, administered by
the federal agency ACTION, with 750 projects and
400,000 volunteers throughout the United States.) El
Paso RSVP members were able to recruit 23 volunteers,
including retired geologists, engineers, planners, and
housewives, to conduct the wellhead protection inventory.
The volunteers attended a day-long ground water
protection seminar and signed up to inventory wellhead
protection areas with which they were familiar. They were
provided with a list of potential contaminant sources, in-
ventory forms in both English and Spanish, maps of their
assigned wellhead protection areas, inventory instruc-
tions, name tags identifying them as volunteer participants
in the project, and a clipboard. Local media ran stories
informing the public about the project and why public
cooperation was needed.
The inventory was expected to take several weeks,
but was actually completed in three and one-half days.
The volunteers identified all known sources of ground
water contamination within the designated areas. They
also suggested several improvements for the inventory,
such as identifying latitude and longitude locations instead
of just a street location, and using a transverse Mercator
grid system to locate potential sources on USGS topo-
graphic maps. After the inventory was completed, five of
the volunteers formed a wellhead protection task force
committee to help ensure that contaminant sources are
properly managed (Cross, 1990).
tection area that might result in ground water pollution.
You can approach this by dividing your wellhead protec-
tion area into small sections and enlisting local volunteers
to identify such activities in the field. Community organi-
zations might be willing to participate in this effort. Volun-
teers should be instructed in how to survey for potential
contaminant sources. Once the volunteers identify an ac-
tivity that could undermine ground water quality, they
should write a description of the activity, its exact location,
the volume of material stored and handled (if readily avail-
56
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able), and the name of an individual to contact for addi-
tional information.
A good map to consult when investigating potentially
damaging activities in your community is the town map-
ping of the sewer service network (see Figure 4-9). The
intent of the sewer network is to collect and transport raw
waste to the sewage treatment plant where it can be
treated prior to disposal. When a map of potential con-
taminant sources is compared to a utility map indicating
where the sewers are, it will become obvious where to
look closely for discharges to ground water—at those
sources not served by a sewer network.
Plot the Potential Sources of
Contamination on a Map
Once all potential sources of contamination have been
identified, each source should be plotted on an overlay
map of your wellhead protection area. This map should
locate waste disposal sites, point sources, underground
septic systems, and underground storage tanks. The map
should indicate where ground water quality has been de-
graded or where there is a good possibility that it has
been impaired. Different symbols should be used to
distinguish among sources of contamination. The main
objective of Step Three in your overall goal of well-
head protection is to prepare a master wellhead protec-
tion area map that shows all existing contaminant
sources and identifies potential threats. This map will fo-
cus your team's protective strategy and land manage-
ment activities.
Evaluate the Degree of Threat Each
Source Poses
To formulate a effective management strategy, it is impor-
tant to evaluate the immediacy and degree of the risk
associated with each potential source of contamination.
Values of risk can be assigned to sources of contamina-
tion based upon their proximity to ground water supply,
contaminant toxicity, the intended use of the ground
water, the degree of local regulatory authority over the
source, or other considerations. Table 4-5 lists general
categories of land uses and ranks them in order of their
risk to ground water. State and federal agencies might be
able to guide your planning team in prioritizing contami-
nant sources according to the degree of threat they pose
to ground water. By assigning risk values like those in
Table 4-5 to the land uses you have identified in your
wellhead protection areas, it will be possible to prepare
a map showing the location and magnitude of potential
threats to your groundwater supply. This map will help
you determine which areas of your community require
immediate attention to prevent contamination. It will also
help you create a long-term defensive planning strategy
for your most vulnerable recharge zones.
Table 4-5. Land Uses and Their Relative Risk to Ground Water
LEAST RISK A. 1. Land surrounding a well or reservoir, owned by a water company.
2. Permanent open space dedicated to passive recreation.
3. Federal, state, municipal, and private parks.
4. Woodlands managed for forest products.
5. Permanent open space dedicated to active recreation.
B. 1. Field crops: pasture, hay, grains, vegetables.
2. Low density residential: lots larger than 2 acres.
3. Churches, municipal offices.
C. 1. Agricultural production: dairy, livestock, poultry, nurseries, orchards, berries.
2. Golf course, quarries.
3. Medium density residential: lots from 1/2 to 1 acre.
D. 1. Institutional uses: schools, hospitals, nursing homes, prisons, garages, salt storage, sewage
treatment facilities.
2. High density housing: lots smaller than 1/2 acre.
3. Commercial uses: limited hazardous material storage and only sewage disposal.
E. 1. Retail commercial: gasoline, farm equipment, automotive, sales and services; dry cleaners; photo
processor; medical arts; furniture strippers; machine shops; radiator repair; printers; fuel oil
distributors.
2. Industrial: all forms of manufacturing and processing, research facilities.
3. Underground storage of chemicals, petroleum.
GREATEST RISK 4. Waste disposal: pits, ponds, lagoons, injection wells used for waste disposal; bulky waste and
domestic garbage landfills; hazardous waste treatment, storage and disposal sites.
Source: Adapted from U.S. EPA, 1989a.
57
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STEP FOUR—Manage the Wellhead
Protection Area5
Your message to the community should include:
~* An dxpicLnation OT wricu ground water is and tl it? ciicols
of ground water contamination on public health.
• Information on how each business and each individual
contributes to ground water pollution.
• Information on how to take good care of a septic sys-
tem.
• Information on the proper disposal of pesticides, sol-
vents, used oil, and other contaminants.
• Water conservation techniques for all activities,
whether commercial, industrial, residential, or agricul-
tural.
• A description of your community's wellhead protection
program, listing your team's accomplishments to date
and goals for the future.
Acquisition of Lands within the Wellhead
Protection Area
The most effective control over susceptible recharge ar-
eas occurs when that land is directly owned or controlled
by the community. In this case, the community can es-
tablish park land, recreation facilities, or other commu-
nity-based land uses. (Alternatively, public access can be
restricted, depending on the nature of the land area.)
Before your community purchases land for the purpose
of wellhead protection, it is important to ensure that the
land is within the aquifer's zone of contribution.
Large-scale land acquisition is extremely expensive and
usually impractical for most small communities. Some
states, however, offer grants to encourage appropriating
vulnerable lands for protection. Some non-profit organi-
zations, such as local or regional land trusts, work to
acquire environmentally sensitive land areas. Often a
public water supplier controls the land directly surround-
ing its water supply wells.
Some alternatives to ownership of land still allow some
control over vulnerable recharge zones. These include
acquisition of "conservation easements" and "restrictive
covenants." Conservation easements are voluntary ar-
rangements restricting a landowner from performing cer-
tain activities (such as using hazardous materials or
installing septic systems) on the land covered by the
easement. The landowners may continue to conduct non-
threatening land use activities in this area. The property
may change hands, but the land restrictions are attached
to the deed. Restrictive covenants are similar to ease-
ments in that they are attached to the deed and apply to
subsequent land owners. Easements are held by another
party who can enforce restrictions, however, whereas re-
strictive covenants can only be enforced by other property
owners similarly restricted. Restrictive covenants may
also prohibit dangerous land practices and restrict devel-
opment densities.
Many wellhead protection area management programs
can be implemented easily and at a low cost to the com-
munity. Several ideas for such programs are presented
below; your planning team, however, should institute
strategies appropriate to the specific needs of your com-
munity. An important place to start is with your most ur-
gent ground water problems. Immediate threats to the
community's water supplies should be addressed first;
then your team can concentrate on the prevention of
potential contamination and the protection of future water
supplies. Table 4-6 summarizes the major non-regulatory
and regulatory tools available for wellhead protection.
Non-regulatory Management Strategies
These management strategies are intended to reach as
broad a spectrum of the community as possible. Ground
water protection is a real possibility only if the whole
community cooperates to achieve this end. The following
programs do not necessarily involve spending a lot of
money or staff time.
Public Education
The major aim of public education is to increase aware-
ness of the threats of ground water contamination, en-
courage voluntary ground water protection (such as
conservation measures and environmentally sound waste
management), and create support for protective regula-
tory initiatives (such as industrial controls and zoning
changes).
To circulate your message throughout the community, you
can use many means, including newspaper articles, local
radio programs, pamphlets, brochures, community meet-
ings, and seminars. A good method of distributing pam-
phlets and other literature is to include them with water
or tax bills. Your committee can develop slide shows or
videos and use them at educational programs or work-
shops. Schools and universities can bring the message
of wellhead protection to all age groups in the community.
School outings to water treatment facilities or to the well-
head area can allow students to look for potential threats
while encouraging them to be aware of how their own
activities can affect drinking water quality. Your commu-
nity should provide alternatives for disposing of potential
contaminant substances (such as by providing a central
location point where waste oil and other materials can be
collected and recycled). Another method of reaching a
large portion of the community is the use of road signs
indicating the most vulnerable areas in your wellhead
protection zone.
For more detailed information on management techniques for well-
head protection areas, see Wellhead Protection Programs: Tools for
Local Governments (EPA 440/6-89-002).
58
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Table 4-6. Summary of Wellhead Protection Tools
Applicability to
Wellhead Protection
Land Use Practice Legal Considerations
Administrative
Considerations
Regulatory: Zoning
Overlay GW
Protection Districts
Prohibition of
Various Land Uses
Special Permitting
Large-Lot Zoning
Transfer of Develop-
ment Rights
Cluster/PUD Design
Growth Controls/
Timing
Used to map wellhead
protection areas
(WHPAs).
Provides for identification
of sensitive areas for
protection.
Used in conjunction with
other tools that follow.
Used within mapped
WHPAs to prohibit
ground-water
contaminants and uses
that generate
contaminants.
Used to restrict uses
within WHPAs that may
cause ground water
contamination if left
unregulated.
Used to reduce impacts
of residential
development by limiting
numbers of units within
WHPAs.
Used to transfer
development from
WHPAs to locations
outside WHPAs.
Used to guide residential
development outside of
WHPAs.
Allows for "point source"
discharges that are more
easily monitored.
Used to time the
occurrence of
development within
WHPAs.
Allows communities the
opportunity to plan for
wellhead delineation and
protection.
Community identifies
WHPAs on practical
base/zoning map.
Community adopts
prohibited uses list
within their zoning
ordinance.
Community adopts
special permit
"thresholds" for various
uses and structures
within WHPAs.
Community grants
special permits for
"threshold" uses only if
ground water quality
will not be
compromised.
Community "down
zones" to increase
minimum acreage
needed for residential
development.
Community offers
transfer option within
zoning ordinance.
Community identifies
areas where
development is to be
transferred "from" and
•to."
Community offers
cluster/PUD as
development option
within zoning ordinance.
Community identifies
areas where
cluster/PUD is allowed
(i.e., within WHPAs).
Community imposes
growth controls in the
form of building caps,
subdivision phasing, or
other limitation tied to
planning concerns.
Well-accepted method of
identifying sensitive areas.
May face legal challenges
if WHPA boundaries are
based solely on arbitrary
delineation.
Well-organized function of
zoning.
Appropriate techniques to
protect natural resources
from contamination.
Well-organized method of
segregating land uses
within critical resource
areas such as WHPAs.
Requires case-by-case
analysis to ensure equal
treatment of applicants.
Well-recognized
prerogative of local
government.
Requires rational
connection between
minimum lot size selected
and resource protection
goals.
Arbitrary large lot zones
have been struck down
without logical connection
to Master Plan or WHPA
program.
Accepted land use
planning tool.
Well-accepted option for
residential land
development.
Well-accepted option for
communities facing
development pressures
within sensitive resource
areas.
Growth controls may be
challenged if they are
imposed without a rational
connection to the
resource being protected.
Requires staff to develop overlay
map.
Inherent nature of zoning
provides "grandfather" protection
to pre-existing uses and
structures.
Requires amendment to zoning
ordinance.
Requires enforcement by both
visual inspection and onsite
investigations.
Requires detailed understanding
of WHPA sensitivity by local
permit granting authority.
Requires enforcement of special
permit requirements and onsite
investigations.
Requires amendment to zoning
ordinance.
Cumbersome administrative
requirements.
Not well suited for small
communities without significant
administrative resources.
Slightly more complicated to
administer than traditional "grid"
subdivision.
Enforcement/inspection
requirements are similar to "grid"
subdivision.
Generally complicated
administrative process.
Requires administrative staff to
issue permits and enforcement
growth control ordinances.
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Table 4-6. Summary of Wellhead Protection Tools (Continued)
AppficaBnitylo
Wellhead Protection
Land Use Practice Legal Considerations
Administrative
Considerations
Performance
Standards
Used to regulate
development within
WHPAs by enforcing
predetermined standards
for water quality.
Allows for aggressive
protection of WHPAs by
limiting development
within WHPAs to an
accepted level.
Regulatory: Subdivision Control
Drainage Require-
ments
Used to ensure that
subdivision road
drainage is directed
outside of WHPAs.
Used to employ
advanced engineering
designs of subdivision
roads within WHPAs.
Regulatory: Health Regulations
Underground Fuel
Storage Systems
Privately Owned
Wastewater Treat-
ment Plants (Small
Sewage Treatment
Plants)
Septic Cleaner Ban
Septic System
Upgrades
Used to prohibit
underground fuel storage
systems (USTs) within
WHPAs.
Used to regulate USTs
within WHPAs.
Used to prohibit small
sewage treatment plants
(SSTP) within WHPAs.
Used to prohibit the
application of certain
solvent septic cleaners,
a known ground water
contaminant, within
WHPAs.
Used to require periodic
inspection and upgrading
of septic systems.
Community identifies
WHPAs and
established
"thresholds" for water
quality.
Community adopts
stringent subdivision
rules and regulations
to regulate road
drainage/runoff in
subdivisions within
WHPAs.
Community adopts
health/zoning
ordinance prohibiting
USTs within WHPAs.
Community adopts
special permit or
performance standards
for use of USTs within
WHPAs.
Community adopts
health/zoning
ordinance within
WHPAs.
Community adopts
special permit or
performance standards
for use of SSTPs
within WHPAs.
Community adopts
health/zoning
ordinance prohibiting
the use of septic
cleaners containing
1,1,1-trichloroethane or
other solvent
compounds within
WHPAs.
Community adopts
health/zoning
ordinance requiring
inspection and, if
necessary, upgrading
of septic systems on a
time basis (e.g., every
2 years) or upon
title/property transfer.
Adoption of specific
WHPA performance
standards requires sound
technical support
Performance standards
must be enforced on a
case-by-case basis.
Well-accepted purpose of
subdivision control.
Well-accepted regulatory
option for local
government.
Well-accepted regulatory
option for local
government.
Well-accepted method of
protecting ground water
quality.
Well-accepted purview of
government to ensure
protection of ground water.
Complex administrative
requirements to evaluate impacts
of land development within
WHPAs.
Requires moderate level of
inspection and enforcement by
administrative staff.
Prohibition of USTs require little
administrative support.
Regulating USTs requires
moderate amounts of
administrative support for
inspection followup and
enforcement.
Prohibition of SSTPs require little
administrative support
Regulating SSTPs requires
moderate amount of
administrative support of
inspection followup and
enforcement.
Difficult to enforce even with
sufficient administrative support.
Significant administrative
resources required for this option.
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Table 4-6. Summary of Wellhead Protection Tools (Continued)
Applicability to
Wellhead Protection
Land Use Practice Legal Considerations
Administrative '
Considerations
Toxic and Hazard-
ous Materials Han-
dling Regulations
Used to ensure proper
handling and disposal of
toxic materials/waste.
Community adopts
health/zoning
ordinance requiring
registration and
inspection of all
businesses within
WHPA using
toxic/hazardous
materials above certain
quantities.
Well accepted as within
purview of government to
ensure protection of
ground water.
Requires administrative support
and onsite inspections.
Private Well
Protection
Used to protect private
onsite water supply wells.
Community adopts
health/zoning
ordinance to require
permits for new private
wells and to ensure
appropriate well-to-
septic-system setbacks.
Also requires pump
and water quality
testing.
Non-regulatory: Land Transfer and Voluntary Restrictions
Sale/Donation
Conservation
Easements
Land acquired by a
community with WHPAs,
either by purchase or
donation. Provides broad
protection to the ground-
water supply.
Can be used to limit
development within
WHPAs.
Limited Development
As the title implies, this
technique limits
development to portions
of a land parcel outside
of WHPAs.
Non-regulatory: Other
Monitoring
Used to monitor ground
water quality within
WHPAs.
Contingency Plans
Used to ensure
appropriate response in
cases of contaminant
release or other
emergencies within
WHPA.
As non-regulatory
technique, communities
generally work in
partnership with non-
profit land conservation
organizations.
Similar to
sales/donations,
conservation
easements are
generally obtained with
the assistance of non-
profit land conservation
organization.
Land developers work
with community as part
of a cluster/PUD to
develop limited
portions of a site and
restrict other portions,
particularly those within
WHPAs.
Communities establish
ground water
monitoring program
within WHPA.
Communities require
developers within
WHPAs to monitor
ground water quality
downgradient from
their development.
Community prepares a
contingency plan
involving wide range of
municipal/county
officials.
Well accepted as within
purview of government to
ensure protection of
ground water.
There are many legal
consequences of
accepting land for
donation or sale from the
private sector, mostly
involving liability.
Same as above.
Similar to those noted in
cluster/PUD under zoning.
Accepted method of
ensuring ground water
quality.
None.
Requires administrative support
and review of applications.
There are few administrative
requirements involved in
accepting donations or sales of
land from the private sector.
Administrative requirements for
maintenance of land accepted or
purchased may be substantial,
particularly if the community
does not have a program for
open space management.
Same as above.
Similar to those noted in
cluster/PUD under zoning.
Requires moderate administra-
tive staffing to ensure routine
sampling and response if
sampling indicates contamination.
Requires significant up-front
planning to anticipate and be
prepared for emergencies.
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Table 4-6. Summary of Wellhead Protection Tools (Continued)
Land Use Practice Legal Considerations
Applicability to
Wellhead Protection
Administrative
Considerations
Hazardous Waste
Collection
Public Education
Legislative:
Regional WHPA
Districts
Land Banking
Used to reduce
accumulation of
hazardous materials
within WHPAs and the
community at large.
Used to inform
community residents of
the connection between
land use within WHPAs
and drinking water
quality.
Used to protect regional
aquifer systems by
establishing new
legislative districts that
often transcend existing
corporate boundaries.
Used to acquire and
protect land within
WHPAs.
Communities, in
cooperation with the
state, regional planning
commission, or other
entity, sponsor a
"hazardous waste
collection day" several
times per year.
Communities can
employ a variety of
public education
techniques ranging
from brochures
detailing their WHPA
program, to seminars,
to involvement in
events such as
hazardous waste
collection days.
Requires state
legislative action to
create a new
legislative authority.
Land banks are usually
accomplished with a
transfer tax established
by state government
empowering local
government to impose
a tax on the transfer of
land from one party to
another.
There are several legal
Issues raised by the
collection, transport, and
disposal of hazardous
waste.
No outstanding legal
considerations.
Well-accepted method of
protecting regional ground
water resources.
Land banks can be
subject to legal challenge
as an unjust tax, but have
been accepted as a
legitimate method of
raising revenue for
resource protection.
Hazardous waste collection
programs are generally
sponsored by government
agencies, but administered by a
private contractor.
Requires some degree of
administrative support for
programs such as brochure
mailing to more intensive support
for seminars and hazardous
waste collection days.
Administrative requirements will
vary depending on the goal of
the regional district.
Mapping of the regional WHPAs
requires moderate administrative
support, while creating land use
controls within the WHPA will
require significant administrative
personnel and support.
Land banks require significant
administrative support if they are
to function effectively.
Source: Horsley and Witten, 1989.
Using Monitoring Wells to Detect Pollution
Ground water monitoring programs around pumping wells
and high-risk sources of contamination can detect poten-
tial pollutants before they infiltrate the public water supply.
A good ground water monitoring program consists of tak-
ing a number of ground water samples on a regular basis,
performing laboratory tests to detect various contami-
nants, and following good quality control/quality assur-
ance procedures. Regular testing will allow your
committee to identify problems quickly and initiate early
remediation procedures. Your success in dealing with
contamination problems depends on the position of the
monitoring wells. The farther these wells are from your
active wells, the more time will be available to rectify the
situation or provide adequate substitute water supplies
should contamination occur. Monitoring might also allow
your team to investigate the effectiveness of source con-
trols (such as limitations on underground storage tanks)
within the wellhead protection area.
Your planning team should do the following before imple-
menting any monitoring program (U.S. EPA, 1989b):
• Collect all of the available existing data pertaining to
your aquifer's water quality. These data can be ob-
tained from your State Department of Environmental
Protection, your State Department of Water Re-
sources, regional agencies, water treatment plants,
hazardous waste facilities, underground injection wells,
consulting engineers, and well-drilling firms.
• Define the overall limits of your ground water monitor-
ing program. This program should be adapted to suit
your community's specific needs with respect to well-
head protection. Your team should decide what geo-
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graphic area the program should cover and what con-
taminants to test for during the laboratory analysis.
• Determine the specifics of the sampling program, in-
cluding sampling frequency, the specific chemical tests
required, and onsite sampling techniques. Your team
could require private well owners to submit samples
for testing to ensure a comprehensive monitoring pro-
gram.
• Investigate the expense of a ground water monitoring
program. Such a program may prove expensive for
small communities because of the costs of drilling new
wells, the need for hydrogeologic expertise to correctly
place the wells, and the costs of using analytical testing
laboratories. Industries should be encouraged to con-
duct self-monitoring.
Monitoring Local Situations
Many potential polluting activities might already be moni-
tored in your community by state and federal authorities.
These include underground injection wells, solid waste
landfills, underground commercial storage tanks, and fa-
cilities that handle hazardous materials. Your team should
identify these activities and, if possible, obtain information
about them from the responsible state agency. Some fa-
cilities, however, might be too small to be inspected by
the state on a regular basis. These should be closely
monitored by your team. Many states grant authority to
local groups to perform inspections. Your team may de-
cide to regularly inspect facilities that are presently un-
regulated or to conduct more extensive inspections of
facilities presently monitored. Inspections should be con-
ducted by trained personnel who can determine what
materials are being used, how they are transported,
where they are stored, what the waste products are, how
they are disposed of, and the safety precautions that
should be taken in the case of a spill (Paly and Step-
pacher, n.d.). This form of local monitoring can also be
implemented at construction sites, which might be a
source of contamination.
Water Conservation
Encouraging water conservation is a crucial element of
any management campaign. This action facilitates your
goal of wellhead protection in two ways: first, by reduc-
ing water withdrawals from your wells, thereby conserving
your primary water source and, second, by protecting
your aquifer from contaminant intrusion by reducing the
rate of contaminant transportation (which is increased by
high pumping rates). Excessive pumping in coastal areas
can result in drawing salt water into the aquifer, causing
poor quality/unpotable water. Where contaminated
plumes exist, conservation might delay contamination at
the wellhead and allow time for remediation work. It is
important to educate the public about the need to con-
serve ground water resources; voluntary efforts might
help the community avoid mandatory controls in the
future.
Encouraging Best Management Practices
Best management practices (BMPs) are standard oper-
ating procedures for a particular industry or commercial
activity that can limit the threat to the environment posed
by ongoing practices, such as pesticide application or
storage and use of hazardous substances (U.S. EPA,
1989b). BMPs prevent the release of toxic substances
into the environment or control these releases in an en-
vironmentally sound manner. BMPs also encourage op-
erating and design standards to ensure the safety of plant
operators and the public.
Facilities in the wellhead protection area that store or
handle hazardous substances—heavy industrial plants,
dry cleaners, gas stations, auto repair workshops, and
transportation facilities such as trucking, railroad, bus de-
pots, and airports—should consider implementing BMPs.
Examples of BMPs include restricting and carefully moni-
toring hazardous materials storage and disposal, and lim-
iting or introducing collection systems for roadway deicing
chemicals. For agriculture, BMPs include minimal chemi-
cal application, chemical application only during dry
periods when infiltration is slow, and erosion and sedi-
mentation controls (U.S. EPA, 1989b).
Your community may choose to enforce mandatory BMPs
or encourage voluntary use through incentives or educa-
tional programs.
Regulatory Management Strategies
Regulatory controls can be adopted by communities to
protect water supplies pursuant to state enabling legisla-
tion. These controls vary in their ability to manage land
uses and activities.
Zoning the Wellhead Protection Area
Communities traditionally have used zoning ordinances
to control and direct development within the community.
Zoning has become a popular process for communities
to safeguard flood plains and wetlands. A community can
consider creating a zoning district to protect aquifers,
recharge areas, and areas of influence by modifying ex-
isting zoning ordinances or creating new ones. Zoning
generally divides communities into specific land use dis-
tricts while specifying a set of applicable regulations for
each district. A ground water zoning ordinance could pro-
hibit specific land uses while requiring special permitting
or performance criteria for less hazardous activities.
Zoning options can provide a variety of opportunities to
prevent high-risk development or activities within your
wellhead protection area. These options depend on the
intensity of development in the areas surrounding the
wells. It is easiest to zone an area that is undeveloped
and "unzoned" (if the community has zoning authority).
Such an area can be zoned for low-density residential
use. This use limits potential contaminant sources in ad-
dition to limiting the amount of impervious material within
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the aquifer's recharge zone. Impervious areas do not
allow precipitation to percolate down to ground water;
therefore, they limit an aquifer's recharge capacity.
Down-zoning consists of changing a zone that has al-
ready been designated for a specific land use to a zone
that is more compatible with your protection goals. This
approach generally involves reducing allowable develop-
ment densities. If an area has been zoned and is partially
developed, it may be possible to "phase-in" zoning re-
quirements over a period of time. For example, a com-
munity can restrict any future construction of high-risk
industrial plants and prohibit the expansion of existing
facilities.
Large-lot zoning of single-family residences is another
method of reducing source contamination through reduc-
ing the number of septic systems. This form of zoning
also protects the permeable acreage of your aquifer's
recharge area by restricting the amount of impervious
material. Large-lot zoning may be less effective in areas
experiencing rapid expansion. Conditional zoning al-
lows certain low-risk land uses, while high-risk uses are
allowed only under strict conditions. This approach can
be used where zones have not been clearly defined.
Cluster zoning is another alternative to controlling resi-
dential development. The aim of this type of development
is to increase the density of a small section of the zone
(cluster of residential units), while maximizing the open
space acreage throughout the zone.
Overlay zoning can be used to define environmentally
sensitive areas over a pre-existing zoning map. The
boundaries of your delineated wellhead protection area
are unlikely to agree with established land-use boundary
zones. An overlay map can help your community imple-
ment management regulations only in those portions of
existing land-use zones that fall within your wellhead pro-
tection area.
It is important to consider the legal aspects of zoning
changes prior to their implementation. Zoning changes
are often sensitive community issues and must not ap-
pear overly restrictive or discriminatory, or court action
could result. Your community's counsel or solicitor should
be able to offer you guidance in this regard. Business
representation on your planning team can help avert po-
tential concerns about zoning changes.
Implementing Subdivision Controls to Minimize
Ground Water Impacts
Subdivision ordinances are most effective in controlling
future land development. They are only applicable when
land is subdivided for sale or development purposes. De-
pending on state enabling legislation, a locality may have
the authority to impose subdivision regulations that con-
trol development. Subdivision ordinances provide guide-
lines for development rather than alter existing land-use
patterns.
The major impetus for subdivision control has been to
protect a community's infrastructure from sudden growth,
and subdivision ordinances to date have reflected this
goal. Subdivision ordinances may also be used, however,
to apply measures for wellhead protection. Such meas-
ures can include requiring low-leakage sewers to inhibit
contamination transportation and requiring the use of en-
vironmentally sound design and construction standards
(such as standards for road and parking lot runoff collec-
tion systems, stream or ditch channels, and road salt
storage areas).
Subdivision control ordinances and zoning ordinances
can be used in combination with site plan reviews and
design and construction standards to formulate an effec-
tive management strategy for wellhead protection. As
with zoning issues, the legitimacy of subdivision control
regulations might be challenged in court. It is therefore
important to seek the advice of your community counsel
or solicitor prior to any enactment of subdivision
amendments.
Implementing Health Regulations to Minimize Risks
to Ground Water
A community can play a significant role in implementing
health regulations to minimize risks to ground water.
Many communities have the authority to adopt regulations
governing any activity that might degrade the quality of
their public water supply. These regulations can include
administering standards for the location, construction,
and operation of septic tanks and leaching fields, and for
regulating solid waste disposal in sanitary landfills. These
duties may be carried out by the Board of Health.
It might be possible to regulate the movement of hazard-
ous materials within your community by limiting the use
of agricultural chemicals over sensitive recharge areas or
restricting and monitoring the use of underground storage
tanks.
Restricting the Storage and Use of Toxic and
Hazardous Materials
Your community might have the authority to regulate haz-
ardous materials, and this can be particularly significant
with respect to commercial and industrial operations in
your wellhead protection area. Many communities require
that any facility handling hazardous materials inform the
local Board of Health about how it uses, stores, trans-
ports, and disposes of these materials. Other regulatory
approaches to controlling the use and storage of hazard-
ous chemicals in your wellhead protection area include
requirements for periodic testing and replacement of un-
derground fuel tanks, permit requirements and corrosion
protection for new tanks, and limitations on herbicide and
pesticide applications.
An approach that has proved successful for a number of
communities is the selection of a hazardous waste coor-
dinator. This coordinator may be a health, fire, or police
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official, or a concerned citizen. The coordinator can help
the community identify and control hazardous sub-
stances, organize hazardous waste committees to pro-
vide advice and support, identify potential sources of
contamination, develop emergency procedures to re-
spond to accidental spills, and educate citizens about
hazardous materials issues.
Requiring Wellhead Monitoring
Ground water monitoring at the wellhead (discussed un-
der Non-Regulatory Strategies above) is essential to as-
sess the quality of the resource and to ensure early
warning of contamination. Many communities require fa-
cilities performing high-risk activities within sensitive re-
charge zones to have monitoring programs and submit
periodic reports to the community.
STEP FIVE—Plan for the Future
Review the Wellhead Protection Plan Yearly
To ensure the long-term success of any wellhead protec-
tion program, it is essential to review and update your
protection plan regularly, perhaps annually. This review
will allow your planning team to improve management
strategies, and it also will give you time to act on any new
information about contaminant sources. Regular review
will help your team deal constructively with new trends
and activities in your community.
Identify Future Problems and Develop
Solutions
A critical aspect of your wellhead protection plan is the
identification of future hazards that threaten your well-
head protection areas. One method of identifying poten-
tial future problems is to analyze your community's
"Development Plan" or "Master Plan." This plan generally
gives some idea of the direction that land development
in the community will take. The plan is usually based on
local zoning maps and zoning regulations. Your team can
use these maps to identify land areas that have been
zoned for commercial and industrial use and that might
prove to be trouble spots. The plan should be carefully
evaluated by your team; it might prove inconsistent with
your overall goals of wellhead protection. Often a devel-
opment plan is only advisory in nature and therefore may
be relatively easy to amend.
In addition to local master development plans, regional
long-term development plans and statewide infrastructure
plans should be reviewed to determine their possible im-
pacts on your community's wellfields. These plans might
indicate highway and major earthworks proposals, new
prison or hospital facilities, and dams or dredging activi-
ties. Major expansion or maintenance plans of local water
and power utilities should also be reviewed. The objective
here is for your team to be aware of forthcoming changes
to your ground water recharge zone so that you can
pursue adequate protection measures.
Another method of determining future risks to your ground
water is to conduct a "build-out analysis" of your commu-
nity's zoning map. This is done by using your land-use
overlay map and existing zoning and subdivision regula-
tions to determine the development potential of each
land-use zone within your wellhead protection area. This
allows you to assess the implications to your aquifer if
every section of developable land within your recharge
zone was built upon. This "saturation analysis" allows
your team to investigate whether your community's zon-
ing and development plans are compatible with its current
and/or long-term need for ground water protection.
One important aspect of a build-out analysis is that it can
be used to help your team anticipate your community's
future water supply needs. It can show the need for new
wells (which should be located to minimize potential con-
tamination). New wells offer your team the opportunity to
implement wellhead protection practices that may have
been difficult to carry out in established wellhead areas.
Your community should consider purchasing land for the
purpose of managing the wellhead protection area for a
future well. Alternatively, you can establish an ordinance
to protect the area around the site for a future well. These
actions will help ensure that the area does not have a
contamination history when the new well is needed.
Develop a Contingency Plan for Alternate
Water Supplies
A vital aspect of a wellhead protection program is the
development of a contingency plan. This ensures that
your community has an alternative water supply in the
event of contamination of your primary source. If possible,
your team should develop both short-term emergency
response alternatives and long-term or permanent water
supply alternatives.
Your team's contingency plan should contain emergency
response procedures to be implemented as soon as pos-
sible following a release of contaminants into the environ-
ment. These procedures should identify the appropriate
personnel to contact at the state and federal level, the
appropriate equipment to have on hand, and a structured
plan of action to respond as quickly and effectively as
possible, to mitigate any environmental damage resulting
from such a release. Your contingency plan will benefit
from good coordination mechanisms, such as an emer-
gency response team, when reacting to emergency spill
situations.
Contact your State Department of Water Resources to
see if it has already developed contingency plans for
public water systems throughout your state, and to gain
information and guidance on contingency planning for
your community's water supply. Your team can adapt
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emergency response frameworks and state contingency
plans for your own community.
Conclusion
The five-step process for wellhead protection can be an
effective way for small communities to prevent contami-
nation of their drinking water sources. This process offers
communities with little or no experience in hydrogeologic
methods a simple, structured approach to establishing a
comprehensive wellhead protection program. Community
planning teams can approach the seemingly daunting
task of ground water protection one step at a time. The
potential rewards of wellhead protection are substantial,
and are well worth the time and effort needed to develop
a successful program. The case studies in Chapter Five
provide a description of how four communities success-
fully tailored elements of this process to their own situ-
ations. Chapter Six lists many of the organizations and
publications that are available to help you develop
and implement a wellhead protection program in your
community.
A wellhead protection plan will help your community avoid the high costs of cleaning up contaminated ground water or
finding a new source of water.
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Chapter 5
Case Studies
CASE STUDY ONE: Hill, New Hampshire,
Water Works
Description of Hill
Hill, New Hampshire, is a small town located in the central
Lakes Region of the state, 21 mi north of Concord, the
state capital. The village district has a population of 325;
the greater town population is 814. The region was origi-
nally a farming and logging area; today, most residents
of Hill make their livelihood as factory workers in the
nearby towns of Bristol and Franklin, or as workers in the t
service industry. The village experienced moderate
growth in the 1980s, which has now tapered off. No more
lot development or building is expected in the village and
slow growth is expected to continue in the region.
The town's village district has a 40-ft-deep, gravel-pack
well drilled in 1941. It supplies water to the village's 125
households. The well has a maximum pumping rate of
36,575 ft3/day with a yield of 190 gallons per minute
(gpm). The drawdown is 0.1 ft, observed during a 3-hr
pump test. Water is used primarily for residential pur-
poses.
The well is located between three mountains to the north,
northwest, and southeast on a shallow slope just upgradi-
ent from Needle Shop Brook and a wet meadow. The well
lies about 1,000 ft southwest from the intersection of a
local and a state road. Upgradient from the well, slopes
are predominantly 8 to 15 percent, although some land
is even steeper (up to 25 percent slope). Closer to the
well, the slope gradient ranges from 3 to 5 percent. Be-
cause of the well's location near the stream and wet
meadow, the water table is assumed to be near the sur-
face, and the saturated thickness is assumed to be 40 ft,
the depth of the well.
The soils upgradient of the well are of the Monadnock
and Lyman series, Monadnock being predominant. The
U.S. Soil Conservation Service (SCS) describes Monad-
nock soils as very deep, well-drained soils on uplands,
formed in a loamy mantle and underlain by sandy glacial
till. They were derived mainly from granite and gneiss and
typically consist of sandy loam to 23 in. deep and gravelly
sand from 23 to 65 in. deep (the substratum). The per-
meability of Monadnock substratum is 2 to 6 in./hr, which
is equivalent to 4 to 12 ft/day. Lyman soils are relatively
shallow (i.e., they reach bedrock at only 17 in.), somewhat
excessively drained, and located on uplands. They were
formed in glacial till and typically consist of a stony loam
surface layer 2 in. deep and a fine sandy loam subsurface
layer from 2 to 4 in. deep. The subsoils are loamy and
range from 4 to 17 in. deep. Lyman soils have the same
permeability as the gravelly sand (2 to 6 in./hr or 4 to 12
ft/day). Flatter land surrounding the well consists of loamy
sands and sandy loams with permeabilities between 6
and 20 in./hr (12 to 40 ft/day). The hydraulic gradient is
0.03 (3 percent).
Overview of Wellhead Protection Issues
Water quality in Hill is considered to be good. To date,
Hill has not experienced problems with contamination of
the water source. When considering the establishment of
a wellhead protection program, the water commissioners
were most concerned about an area immediately sur-
rounding the well, an old farm with very high development
potential. The commissioners and the town selectmen
also were concerned about the way in which a wellhead
protection program would be initiated in the community.
They stressed the need for clear communication and al-
leviation of property owners' fears—both about the quality
of their ground water and control of their properties.
Approach Used to Form a Community
Planning Team
Hill's Water Commissioner Dean Wheeler initially con-
tacted the New Hampshire Department of Environmental
Services to get information about ground water protec-
tion. He was referred to John Lukin, the Northeast Rural
Water Association (NeRWA) ground water technician for
the states of Massachusetts, New Hampshire, and
Vermont.
After a phone conversation in August 1991, the two set
up an exploratory meeting that also included several se-
lectmen, another commissioner, and the farmer and
owner of the lot immediately surrounding the well. Lukin
wrote of his visits with Hill and other New England com-
munities: "Initial visits to systems were never canned
67
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presentations. NeRWA assistance was explained in de-
tail, including the funding source and program objectives.
However, the sessions generally were exchanges with
local officials or the system manager/operator that ob-
tained information about the system and community, while
building rapport." At the end of their meeting, participants
agreed that a ground water protection program for Hill
was a sound idea. A community planning team was cre-
ated, with the two commissioners, the NeRWA technician,
and one of the selectmen as its members. As their first
task, team members agreed to research pump test data
on Hill's well.
Approach Used to Delineate the Wellhead
Protection Area
Fairly good site-specific information on well construc-
tion, soil type, and ground water flow was available for
Hill. The technician used guidance from the New Hamp-
shire Department of Environmental Services (NHDES) to
delineate the area. The guidelines propose a phased
approach that utilizes maximum pump rate data, trans-
missivity, hydraulic gradient, and U.S. Geological Survey
(USGS) topographic information to delineate the well-
head protection area. The wellhead protection area
boundary upgradient of a well is drawn at any ground
water divide (i.e., watershed boundary) or at 4,000 ft,
whichever is encountered first. The topographic upgradi-
ent of the well is also assumed to be the well upgradient.
The boundary of the wellhead protection area down and
side gradient is calculated using transmissivity, pump
rate, and hydraulic gradient information in the uniform
flow equation.
The major topographic features to the north, northwest,
and southeast determine the upgradient boundary of the
Hill wellhead protection area. The wellhead protection
area is delineated at 4,000 ft to the northwest and south-
west, and extends about 2,000 ft southwest to the top of
Huses Mountain. The maximum downgradient distance
of the wellhead protection area, running to the northeast
along Needle Shop Brook, is approximately 400 ft. Be-
cause the down and side gradient area around the well
consists of loamy sand and sandy loam soils, and the
drawdown is 0.1 ft, the transmissivity (T) of the area is
considered representative of the highest permeability (40
ft/day) and is equivalent to 1,600 ft2/day (40 ft/day x
40-ft-deep well). The technician used the 0.03 (3 percent)
gradient for the relatively flat area nearest the well to build
the equation, resulting in a more conservative delineation
(see Figures 5-1 and 5-2 for delineation work).
The wellhead protection area was first mapped on a
USGS topographic map (Figure 5-3) and transferred to a
local property tax map (Figure 5-4). To transfer the infor-
mation, the technician enlarged the topographic map to
match the scale of the tax map and then traced the well-
head protection area onto the tax map. Although this
procedure distorts somewhat the accuracy of the well-
head protection area, it is adequate for identifying the
properties affected by the wellhead protection area. The
technician submitted the Hill wellhead protection area to
the state hydrologist for review before going on with the
next step of the program.
Approach Used to Identify and Locate
Potential Sources of Contamination
Two other planning committee members carried out the
inventory for potential sources of contamination. They
used their own knowledge and town records to establish
ownership and use of the wellhead protection area and
conducted limited fieldwork.
According to their findings, the wellhead protection area
lies over 30 separate parcels. Ten of the parcels are in
residential use, 15 lie over woodland areas, and 5 lie over
open meadows. In addition, the wellhead protection area
incorporates the town solid waste transfer station, State
Highway 3A and town roads, a small engine repair shop,
and the town cemetery. All of these are considered po-
tential sources of contamination. The team used the
NHDES list and other resources to prioritize potential
contaminant sources. By far the area of greatest concern
was the transfer station on Lot R6-40. Although not a
current threat to ground water, farm lot R6-46 to 49 re-
mained a concern to the team.
Approach Used to Manage the Wellhead
Protection Area
The team chose low-cost, attainable measures to man-
age its wellhead protection area. Hill will rely on voluntary
compliance to protect its ground water system. The board
of selectmen will notify landowners and municipal agen-
cies and ask them to incorporate the following practices
into their activities:
Transfer Station—The transfer station will operate in ac-
cordance with New Hampshire regulations governing
such facilities and use Best Management Practices
(BMPs) to guard against ground water contamination.
BMPs include the use of impervious surfaces—such as
metal or concrete—to transfer waste and operating prac-
tices that prevent leakage of contaminants into water and
soil. Hazardous wastes are not to be stored at the site.
State Highway 3A and Town Roads—The Town of Hill will
notify the New Hampshire Department of Transportation
(NHDOT) in writing of State Route 3A's passage through
Hill's wellhead protection area and send the transporta-
tion department a copy of the wellhead protection area
map. The notification will request that the NHDOT apply
minimal road salt to the affected section of the highway.
Hill will deice the local roads in the wellhead protection
area using a sand/salt mixture that minimizes the use of
salt. The town also will post signs along the roadways to
68
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12/8/91 HILL, NH DELINEATION WORK
200'
Gradient: W along Needle Shop Brook = = 0.05
120'
NW along small tributary stream = = 0.03
Pumping Rate: = 190 gpm from USGS information
= 36575 ffVday
Transmissivity
Upgradient of well, dominant soils are of the Monadnock Series. SCS Soil Interpretation Records identify the
substratum (23" to 65") as "gravelly sand." Permeability at this depth is noted as 2.0 to 6.0 in./h = 4.0 to 12
ft/day. These soils (Ca, Ch, Hm) are also labeled Lyman Series, which are shallow to bedrock (17"). Permeability
is the same. Slope is predominantly 8 to 15% with some 15 to 25%.
The flatter land close to the well is loamy sands and sandy loams with permeabilities between 6 and 20 in./h
(12 to 40 ft/day).
Well depth is 40' (USGS, town system generator) and recorded drawdown is 0.1 ft (USGS). Since well is adjacent
to stream and with a wet meadow just downgradient, the water table is assumed to be near the surface. Therefore
40' = saturated thickness.
T = hydraulic conductivity x saturated thickness
T = 4 ft/day x 40' = 160 tf/day
= 12 ft/day x 40' = 480 ft2/day
= 40 ft/day x 40' = 1600 ft2/day
Since down and side gradient soils are the loamy sand/sandy loams, and observed drawdown during a
3 h pump test was 0.1 ft, the uniform flow equation T will be the greatest value of 1600 f^/day.
x_ 36,575 _ 36,575 _ y
502.656
Y = QS'QQ = 457' = maximum width of ZOC - not used here
or
v= _ 36,575 _ _ 36,575 _1g1 _,
(6.2832) (0.03) (1600) 301 .6 ' y
Since land closest to well is relatively flat, the 0.03 gradient is proposed for determining the Phase I recharge
area. The result is a more conservative delineation.
Conversion to 1:24,000 scale for mapping on topo sheet:
1 X 1 Y
@T = 480
24,000 125' 24,000 765'
X = 0.0625" Y = 0.3825" X = 404' = 0.202"
Figure 5-1. Calculations for delineation of the Hill wellhead protection area.
69
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Phase I Wellhead Proieciion Area Delineation Guidance
AppenduTX
WORKSHEET TO ACCOMPANY A PHASE I WHPA DELINEATION
' ' ' ^ "
Town:
Wel1 Name:
ID #
Well Type: Overburden V Bedrock _ / Drilled _ Dug _ Other(specify)
Population Served: '^'C people: Town(s) of "'//• ^^/
Well Owner Information: Name
Address
Phone#
Contact Information: Name
Address
Phone*
P0
trill ,
AS
"T
Street Address of Well Location (attach locus map)
: FT iff
I. Information obtained to perform delineation:(please check on left if found)
_ USGS map: Quadrangle name(s)
_ Surficial geology map: name(s)
0/-/'O/yi/
USGS stratified drift aquifer map: name(s)
]/ SCS map: survey name jv>*
_ WSPCD/WSEB files:
_ well log(s) ' '
_ pump test: date
_ maximum yield
t
duration
page(s)
Dated
Dated
Dated
Dated
\ar
i
_ Owner/Operators files:
_ well k>g(s)
_ •_ >pumptestt date
_ maximum yield
• duration
_ WRD/WMB boring togs:
J/ Other (please ii.»v US/r 5"
(continued on reverse)
Figure 5.2. Worksheet on delineation of the Hill wellhead protection area.
70
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Prase i weimeaa Protection Area delineation Guaance Appendix A (cont'd)
II. Describe hydrogeologic mapping for upgradient boundary (attach sheet(s) if necessary).
Information Utilized:
Narrative:
111. Complete the following chart and show calculation using the Uniform Flow Equation to derive the
WHPA boundary down and side gradient of the well. Identify all flow boundaries encountered before
the calculated distance (attach sheet(s) if necessary).
Parameter Value and Units Source of Information
Maximum Pumping Rate Q = 3^.
Transmissivity* T
•/
Hydraulic Gradient i= fff3
•Specify Hydraulic Conductivity and saturated thickness used if T is calculated
Show the calculation performed using the Uniform Fbw Equation:
fy -
^'
_ s^rzc. - 3/r?
Describe any flow boundary identified within the calculated boundary:
Comments:
IV. Attach the delineation and a copy of all information gathered and utilized. Provide a listing of all
information submitted.
Figure 5.2. Worksheet on delineation of the Hill wellhead protection area (continued).
71
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WELLHEAD PROTECTION PLAN tlAP
Well Name (tt) ; go /
Foster Swamp
CONTOUR INTERVAL 6 METERS
Figure 5-3. Delineated wellhead protection area on topographic base.
72
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Figure 5-4. Wellhead protection area transferred to village tax map.
73
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indicate to motorists that they are driving through a public tions and ensuring that their contractors use BMPs as
water supply recharge area.
Small Engine Repair Shop—Hill will notify the land owner
of the extent to which his property is situated in the well-
head protection area and ask him to cooperate by using
BMPs to run his shop. BMP information will be provided
to the land owner. BMPs include proper storage and dis-
posal of potentially hazardous products like waste oil,
antifreeze, solvents, used filters, paint, and batteries, as
well as practices that minimize leakage. NHDES also
encourages use of alternative products and technologies,
such as aqueous cleaners and high-pressure water
washes for cleaning, and recycling of products such as
solvents, antifreeze, and engine oil.
Residential Properties—Hill zoning allows for "rural resi-
dential uses" within the recharge area. Minimum lot size
is 3 acres. To better protect the public water supply, the
town will seek classification of the ground water in the
recharge area according to the state of New Hampshire's
Ground Water Protection Act (RSA 485-C). In addition,
the town will explore the creation of a ground water pro-
tection overlay district to conform with the wellhead pro-
tection area and promote closer scrutiny of proposed land
use activities within the wellhead protection area.
Hill will notify property owners in writing of the location of
their properties within the wellhead protection area and
will ask them to cooperate by properly operating and
maintaining their septic systems and properly using, stor-
ing, and disposing of household hazardous materials. The
property owners will be provided with information on
these practices.
Woodland—Much of the woodland in the wellhead
protection area is in the New Hampshire Current Use
Program, which provides tax liability reductions for main-
taining open space. Financial penalties are assessed to
change the use. Hill will notify landowners that their land
falls within the wellhead protection area and will ask them
to cooperate by using BMPs during any logging opera-
well, especially when using gasoline and OH.
Fields—Currently, no chemical fertilizers, pesticides, or
herbicides are used on the fields. Hill will ask field land-
owners to continue to refrain from using chemicals on
their properties.
Cemetery—The town will refrain from using herbicides,
pesticides, or fertilizers on the town-owned cemetery
grounds, and the town will ask the owners of the private
cemeteries to do the same.
Approach Used to Plan for the Future
The team felt that the geologic setting of the Town of Hill
Village District well should promote relatively rapid flush-
ing of any contamination of the aquifer adjacent to the
well. Hill's short-term solution to any unanticipated loss
of water from the well will be to supply bottled water. If
Hill permanently loses its present source of water, the
town will continue to implement the short-term solution
until another water source is developed and brought on
line.
Conclusion
The planning team members successfully carried through
the first four steps of the five-step wellhead protection
process: they formed a planning team; with the techni-
cian's assistance, they delineated the wellhead protection
area; they identified potential sources of contamination;
and they created an approach for managing potential
contamination sources. They are now on Step Five, hav-
ing developed a plan for the future, including some con-
tingency plans.
The planning team attributed the success of the program
to date, in part, to meeting the challenges of explaining
the program to the community and thus alleviating poten-
tial concerns. Technician John Lukin has provided edu-
cational materials to the selectmen for use in the wellhead
protection program.
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CASE STUDY TWO: Village of
—Cottage Grove, Wisconsin—
Approach Used to Form a Community
Planning Team
Description of Cottage Grove
The village of Cottage Grove is located in south central
Wisconsin, 15 mi west of the capital city of Madison. Once
a small farming community, the village is now part of the
broad suburban ring that surrounds Madison. Many of its
1,200 residents work in the capital for the state or for the
University of Wisconsin. Several small industries also
support the village. They include Avganic Industries, Inc.;
Hydrite Chemical; the Dane County Farmers Union Co-
operative; Badger Lumber; and a handful of service in-
dustries. A new highway between Madison and Cottage
Grove and the recent sale of public land to developers
have spurred village growth exponentially. The population
grew from 900 to 1,200 between 1989 and 1992, and the
village clerk estimates that 800 dwelling units have been
approved or are about to be approved for construction.
Cottage Grove lies in a region of rolling hills, on a base
of sandstone, mostly of the Wonewoc formation. The
sandstone aquifer under the village wells is approximately
725 ft deep, with an average hydraulic conductivity of 5.5
x 10"5 cm/sec. There are no bodies of water or surface
streams in the area. Like 95 percent of Wisconsin's com-
munities, Cottage Grove relies solely on ground water
wells for its water supply. Two wells serve the village area.
They are located generally in the central district of the
village, surrounded by residences and small businesses.
Well #1 is located on Main Street, the village's north-south
artery, near the intersection of Taylor Street. Well #2 lies
in the midst of a residential development framed by Cot-
tage Grove Road to the north and Main Street to the east
(see Figure 5-5).
Overview of Wellhead Protection Issues
The village was actively involved in surveying and pro-
tecting its ground water when it contacted the Wisconsin
Rural Water Association (WRWA) for technical assis-
tance. The location of Avganic Industries and the adjacent
Hydrite Chemical Company, just 0.5 mi from Well #1 (and
1 mi from Well #2), caused concern about wellwater con-
tamination. Drums containing a multitude of chemicals
had been discovered on the Avganic site, owned and
operated by North Central Chemical in the 1950s. The
drums were found to have leached into the soil through
their cement pad and contaminated much of the site.
Avganic was defining the plumes and preparing for reme-
diation under the Resource Conservation and Recovery
Act (RCRA). The village was also conducting its own
study of the Avganic facility. In addition, serious ground
water contamination problems from atrazine use were
identified in the southern portion of the village near the
Dane County Farmers Union Cooperative.
Village utility director Christine Diebels met the WRWA
ground water technician, Jill Jonas, at a state wellhead
protection conference in May 1991. In early July, the vil-
lage president contacted Jonas to request help with de-
veloping the village's wellhead protection program.
Specifically, the village was interested in assistance with
delineating wellhead protection areas for Wells #1 and #2
and a proposed well (Well #3) (see Figure 5-5) in the
northern area of the village to replace the threatened Well
#1. The WRWA technician agreed to assist the village
with its program.
In mid July, the technician met with the utility director to
discuss the program. They constituted the core of the
team that would take the program through the delineation
phase and provide the impetus for completing the pro-
gram. One distinct advantage that this core team had was
its level of expertise—the village's utility director also is
a trained hydrogeologist. They immediately began work
on delineating the protected areas. As the wellhead pro-
tection program developed, they would bring the village
clerk, the village attorney, the utility board, and area citi-
zens and businesses into the planning process.
Approach Used to Delineate the Wellhead
Protection Area
An abundance of geologic data on Well #1 was available
from the RCRA study. Several documents existed on the
solvent remediation program alone. The team's challenge
was to determine which information would be most useful
in delineating the wellhead protection areas. In addition,
Avganic Industries offered to provide information for sim-
ple calculations of ground water travel time. Research of
existing materials proved to be extensive. Among the
most useful pieces of data was the Geological Survey
Water-Supply Paper 1779-4 developed for the USGS. It
provided essential hydrogeologic information, including a
potentiometric map with a ground water divide. The tech-
nician cross-referenced these data with information from
the remediation project.
Initially the technician used the uniform flow equation (see
Chapter Four) to delineate areas for all three wells. Figure
5-6 shows her delineation of the wellhead protection ar-
eas for all three wells using this method. No guidance or
state oversight on delineation was available from the state
of Wisconsin, which is still in the process of developing
a wellhead protection program for public water supplies.
The technician requested a review of the initial delineation
from a hydrogeologist for the Wisconsin Geological and
Natural History Survey. He recommended using a more
complex delineation approach to account for interference
between the wells. He suggested using the EPA comput-
erized WHPA Code semianalytic model (see Chapter
Four) and provided training.
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Figure 5-5. Zoning map of Cottage Grove with well locations.
76
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Figure 5-6. Delineation of Cottage Grove wellhead protection areas using uniform flow equation.
77
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In the meantime, the village decided to abandon Well #1.
They asked that the technician delineate wellhead pro-
tection areas for Well #2 and proposed Well #3. The
wellhead protection areas for these wells were delineated
using the WHPA Code program, incorporating zones of
contribution for times of travel (TOTs) of 1, 5, 50, and 100
years into the model. The resulting wellhead protection
areas are shown in Figure 5-7. The ground water contrib-
uting to Cottage Grove's wells comes from the northwest
and runs southeasterly. The wells are delineated to the
west by the ground water divide based on the USGS data.
The zone of contribution for 50 years extends approxi-
mately 8,000 ft northwest to Interstate 94, incorporating
several major developments that lie outside the village
jurisdiction in Cottage Grove. To the southeast, the down-
gradient zone of contribution extends approximately 600
ft for both wells. The wellhead protection areas based on
these zones lies beyond the ground water flow affected
by Avganic Industries, Hydrite, and Dane County Farmers
Union Cooperative. It incorporates the northern half of
the village dominated by residential zones and small
businesses.
Approach Used to Identify and Locate
Potential Sources of Contamination
The technician worked closely with the village clerk to
identify potential sources of contamination. Together they
matched maps of the village with ownership and address
information on file to identify owners and uses of lots.
Because they were concerned with managing ground
water contaminants in the entire village, they considered
all lots within the village jurisdiction. They simplified a
cumbersome process of identifying all possible contami-
nant sources from among the 51 lots by using an inven-
tory format developed by the WRWA (similar to Figure
4-15 in Chapter Four). Each known use from the clerk's
list was matched against the established list of "potential
contaminant sources" identified on the inventory sheet
and assigned a reference number. Locations of repeated
use, such as the three cemeteries in Cottage Grove, were
differentiated by letter. Using this method, the clerk and
technician located 48 potential sources of contamination
from among 24 different uses (see Figure 5-8). Twelve of
these were located within the designated wellhead pro-
tection areas. Members of the Cottage Grove Historical
Society also helped with the inventory. The members of
the society, most of them elderly, used their knowledge
of the community and research skills to locate old cisterns
and gas pumps. Of the list of 20 they provided, the team
eliminated 17 (tanks that had already been removed) and
incorporated 3 into its list of potential contamination
sources. Although the wellhead protection areas did in-
clude fuel stations and small repair shops, retailers, a
general store, laundry, and lumber retailer, these potential
sources were not considered major threats to the well-
head protection areas.
Approach Used to Manage the Wellhead
Protection Area
Once the inventory process was complete, the planning
team, with the village clerk, set up a meeting with the
utility board, the parks program, and the planning depart-
ment. Using the comments from this meeting, the utility
board then went to work on drafting a resolution and
ordinance to manage the village's ground water. The
board called on the various skills available in the village
community to draft the document language. The utility
director, in conjunction with the technician, provided tech-
nical guidance, the village attorney provided legal exper-
tise, and village residents provided the "common sense"
that made the ordinance a readable public document. The
ground water ordinance was meant to be a sweeping
long-term plan to include all areas of the village and
ensure safe drinking water into the next century.
Three public hearings were held on the ground water
protection ordinance between November 1991 and April
1992. To encourage public participation, the village clerk
posted announcements of the meetings in seven public
locations, placed notices in the local papers, and issued
a memo to sectors of the community that had a special
interest in the ordinance. The clerk's November 8, 1991,
memo (see Figure 5-9) invited the village board, the utility
commission, the village attorney, the village engineer, the
director of public works, committee chairpersons, and
personnel from Avganic Industries, Dane County Coop,
Hydrite Chemical, and Kessenich General Store to the
public hearing held on December 2, 1991.
Citizens and village businesses were very active in the
hearings. Avganic Industries in particular requested clari-
fication of the technician's methods and suggested a
number of useful modifications. The company's sugges-
tion to use a numerical model to redefine the wellhead
protection areas was considered over a subsequent 30-
day period, but was rejected because of the cost. The
utility director estimates that using such a model would
have cost the village several hundred thousand dollars.
Numerous meetings also were held between the village
attorney, the technician, and the utility director.
On April 20, 1992, the Village Board of Cottage Grove
adopted a resolution (see Figure 5-10) requesting that
"Dane County, the Town of Cottage Grove, and the Wis-
consin Department of Natural Resources . . . consider
wellhead and ground water protection in making permits,
zoning, subdivision, and other related land use ordi-
nances, regulations, or decisions for areas possibly af-
fecting the wells of the Village of Cottage Grove."
The Board also added a Wellhead Protection Ordinance
(Figure 5-10) to the Municipal Code "to institute land use
regulations and restrictions to protect the village's munici-
pal water supply and well fields, and to promote the public
health, safety and general welfare of the residents of the
78
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Figure 5-7. Delineation of Cottage Grove wellhead protection areas using WHPA Code computer program.
79
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Reference: Wellhead Protection Ordinance
Village of Cottage Grove
01A) Blackhawk Airport, Kennedy Rd.
02A) Fredenberg property (inactive silage pit), CTH N north of Natvig Rd.
03A) Two Buck Automotive Rebuilders & Service, 212 V.'Cottage Grove Rd.
03B) " " " " " , 212A W. Cottage Grove Rd.
03C) Village of Cottage Grove (truck and eqpt. storage), 117 Reynolds St.
03D) Village of Cottage Grove (garage), 300 S. Main St.
03E) K £ S Automotive and Grove Machine £ Tool, 351 S. Main St.
03F) Michael Schraufnagel residence (restored old cars in large garage) 132 B Woodview Dr.
03G) Ron Mueller's Service (auto service, UST), CTH TT and CTH N
03H) Larson's Automotive (UST), CTH TT and CTH N
031) Town of Cottage Grove (garage, truck and automotive supplies storage), 4091 CTH N
04A) Cemetery, CTH N south of Gaston Rd.
04B) Cemetery, W. Cottage Grove Rd.
04C) St. Patrick's Church (cemetery), 434 N. Main St.
05A) Hydrite Chemical Co. (chemical packaging company), 150 Donkle St.
06A) Town & Village of Cottage Grove (closed landfill), Natvig Rd. £ CTH N
07A) Dane County Farmers' Union Co-operative (feed mill), 241 Clark St.
07B) Dane County Farmers' Union Co-operative (grain bins, automotive repair, pesticide
truck cleaning, agri-chemical storage), CTH N and Coffeytown Rd.
07C) Garst Seed Co. (Agri-chemical), 2560 Nora Rd.
08A) Huston Bros. Garden Center, CTH N and Coffeytovn Rd.
09A) Dane County Farmers' Union Co-operative (fertilizer plant), 251 Clark St.
09B) Gus Paraskevoulakos (restaurant eqpt. storage - former Dane County Farmers' Union
feed mill), 356 S. Main St.
10A) Gerald Strouse property (sludge lagoons), Vilas Rd.
11A) " " " (sludge spreading), Vilas Rd.
12A) Mall - Suds Your Duds (laundry), 214 W. Cottage Grove Rd.
13A) Chicago & Northwestern Transportation Co. (railroad), division of N & S Main Sts.
13B) Interstate 94 (gas station) 194 £ CTH N
14A) Irving Smith property (former gravel pit filled with highway construction debris)
CTH N £ Gaston Rd.
14B) Gerald Strouse property (active mineral extraction site) CTH N south of Gaston Rd.
14C) Dean £ Barb Everett, d/b/a Viking Stone (active'mineral extraction site), Gaston Rd
north of CTH N
15A) Town of Cottage Grove (salt storage), CTH N south of Village limit
ISA) Eugene Fredenberg residence (unsewered), 357 S. Grove St.
16B) Theron Uphoff residence (unsewered), 377 S. Grove St.
16C) Lisa Vitense £ Rick Hatton residence (unsewered), 362 S. Grove St.
16D) Nondahl Heights subdivision (failing septic systems), Vilas Rd.
17A) Kessenich's General Store, 585 N. Main St.
17B) Dane County Farmers' Union Co-operative (car wash, diesel £ gasoline UST, LP tanks,
hardware store), 205 V. Cottage Grove Rd.
ISA) Dick's Market c/o Jerry Stoddard, 205 E. Cottage Grove Rd. locker plant
18B) Hollywood Dressed Beef (slaughterhouse), Pieper Rd.
19A) LSJ Enterprises (now vacant), 202 W. Cottage Grove Rd.
19B) J. R. Fritz (miscellaneous storage), 127 Reynolds St.
19C) Village of Cottage Grove (storage shed), 116 Reynolds St.
20A) Chase Lumber, 123 E. Cottage Grove Rd.
20B) Badger Lumber (wholesaler), 120 N. Main St.
21A) Universal Hair Design (beauty shop), 214 W. Cottage Grove Rd.
22A) Conklin Electric, 204 W. Cottage Grove Rd.
23A) Avganic Industries (hazardous waste recyclers), 114 N. Main St.
24A) Robert Hartwig (buried railroad tanker for fuel oil), 712 Willow Run Ct.
Figure 5-8. List of potential contaminant sources for Cottage Grove.
80
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lOff OT
J J
156
53521
MEMO
To: Village Board
Utility Commission
Village Attorney
Village Engineer
Director of Public Works
Commission/Committee Chairpersons
Avganic Industries
Dane County Farmers' Union Co-op
Hydrite Chemical
Kessenich General Store
From: Village Clerk
Date: November 8, 1991
Re: Proposed Wellhead Protection Ordinance
The Water & Sewer Commission is proposing that the attached
wellhead protection ordinance be adopted by the Village. A public
hearing has been scheduled for December 2, 1991 at Flynn Hall.
The ordinance would place some restrictions on land use within the
village in an effort to protect the municipal water supply. If you
have any questions about the ordinance or the hearing, please call
me at 839 - 4704.
Figure 5-9. Village clerk's memo announcing proposed wellhead protection ordinance and public hearing.
81
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o
11(5 noo tr«f o0( icc ox 156
5352T
RESOLUTION NO. 92-03
VILLAGE OF COTTAGE GROVE
DANE COUNTY, WISCONSIN
A RESOLUTION OF THE VILLAGE OF COTTAGE GROVE TO DANE COUNTY, THE
TOWN OF COTTAGE GROVE AND TO THE WISCONSIN DEPARTMENT OF NATURAL
RESOURCES, REQUESTING THAT WELLHEAD PROTECTION AND GROUNDWATER
PROTECTION CONSIDERATIONS BE WEIGHED IN MAKING PERMITS AND ZONING,
SUBDIVISION, AND OTHER RELATED LAND USE ORDINANCES, REGULATIONS, OR
DECISIONS.
WHEREAS, it is within the responsibility of the Village of Cottage
Grove, as a public water supplier, to consider the health, safety,
and welfare of it's customer; and
WHEREAS, groundwater contamination can and does occur as a
consequence of a variety of land use activities; and
WHEREAS, it is desirable to preserve and protect the quantity and
quality of our groundwater resources to assure a continued safe,
adequate, and usable supply, now and in the future; and
WHEREAS, protection of current and potential future sources of
groundwater is worthwhile from the standpoint of resource
protection;
NOW, THEREFORE, BE IT RESOLVED by the Village Board of Cottage
Grove, that we do respectfully ask that Dane County, the Town of
Cottage Grove, and the Wisconsin Department of Natural Resources to
consider wellhead and groundwater protection in making permits,
zoning, subdivision, and other related land use ordinances,
regulations, or decisions for areas possibly affecting the wells of
the Village of Cottage Grove.
ADOPTED this 20th day of April, 1992, by the Village Board of
Cottage Grove, by unanimous vote.
Village of Cottage Grove
Official Signature
ATTEST:
Linda S. Ketti^ger, cferk
Figure 5-10. Cottage Grove wellhead protection resolution and ordinance.
82
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AN ORDINANCE CREATING
CHAPTER 18 OF THE MUNICIPAL CODE
FOR THE VILLAGE OF COTTAGE GROVE
The Village Board for the Village of Cottage Grove, Dane County,
Wisconsin, does hereby ordain as follows:
SECTION I; Chapter 18 of the MUNICIPAL CODE FOR THE VILLAGE
OF COTTAGE GROVE is hereby created to read as
follows:
SECTION 18.1. CONSTRUCTION OF ORDINANCE
(a) TITLE
This Chapter shall be known, cited and referred to as the
"Wellhead Protection Ordinance" (hereafter WHP ORDINANCE).
(b) PURPOSE AND AUTHORITY
1. The residents of the Village of Cottage Grove
(hereafter VILLAGE) depend exclusively on groundwater for a safe
drinking water supply. Certain land use practices and activities can
seriously threaten or degrade groundwater quality. The purpose of the
WHP ORDINANCE is to institute land use regulations and restrictions to
protect the VILLAGE'S municipal water supply and well fields, and to
promote the public health, safety and general welfare of the residents
of the VILLAGE.
2. These regulations are established pursuant to the
authority granted by the Wisconsin Legislature in 1983, Wisconsin Act
410 (effective May 11, 1984), which specifically added groundwater
protection to the statutory authorization for municipal planning and
zoning in order to protect the public health, safety and welfare.
(c) APPLICABILITY
The regulations specified in the WHP ORDINANCE shall apply
within the VILLAGE'S corporate limits.
SECTION 18.2. DEFINITIONS
(a) Existing Facilities Which May Cause Or Threaten To Cause
Environmental Pollution - Existing facilities which may cause or
threaten to cause environmental pollution within the corporate limits
of the VILLAGE'S well fields' recharge areas which include but are not
limited to the Wisconsin Department of Natural Resources' draft list
of "Inventory of Sites or Facilities Which May Cause or Threaten to
Cause Environmental Pollution," "Department of Industry, Labor and
Human Relations (hereafter D.I.L.H.R.) list of Underground Storage
Tanks (hereafter UST's) and list of facilities with hazardous, solid
waste permits, all of which are incorporated herein as if fully set
forth.
Figure 5-10. Cottage Grove wellhead protection resolution and ordinance (continued).
83
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(b) Groundwater Divide - Ridge in the water table, or
potentiometric surface, from which ground water moves away at right
angles in both directions. Line of highest hydraulic head in the
water table or potentiometric surface.
(c) Groundwater Protection Overlay District - Shall be defined
as that area contained in the map attached as Exhibit A and
incorporated herein as if fully set forth.
(d) Recharge Area - Area in which water reaches the zone of
saturation by surface infiltration and encompasses all areas or
features that supply groundwater recharge to a well.
(e) Well Field - A piece of land used primarily for the purpose
of supplying a location for construction of wells to supply a
municipal water system.
SECTION 18.3. GROUNDWATER PROTECTION OVERLAY DISTRICT (hereafter
DISTRICT)
(a) INTENT. The area to be protected is the Cottage Grove well
fields' recharge areas extending to the groundwater divide (as
determined by the UNITED STATES GEOLOGICAL SURVEY WATER SUPPLY PAPER
1779-U, incorporated herein as if fully set forth) contained within
the VILLAGE boundary limits. These lands are subject to land use and
development restrictions because of their close proximity to the well
fields and the corresponding high threat of contamination.
(b) PERMITTED USES. Subject to the exemptions listed in Section
18.4, the following are the only permitted uses within the DISTRICT.
Uses not listed are to be considered prohibited uses.
1. Parks, provided there is no on-site waste disposal or
fuel storage tank facilities associated within this
use.
2. Playgrounds.
3. Wildlife areas.
4. Non-motorized trails, such as biking, skiing, nature
and fitness trails,
5. Residential municipally sewered, free of flammable and
combustible liquid underground storage tanks.
(C) REQUIREMENTS FOR EXISTING FACILITIES.
1. Facilities shall provide copies of all federal, state
and local facility operation approvals or certificate
and on-going environmental monitoring results to the
VILLAGE.
-2-
Figure 5-10. Cottage Grove wellhead protection resolution and ordinance (continued).
84
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2. Facilities shall provide additional environmental or
safety structures/monitoring as deemed necessary by the
VILLAGE, which may include but are not limited to
stormwater runoff management and monitoring.
3. Facilities shall replace equipment or expand in a
manner that improves the existing environmental and
safety technologies already in.existence.
4. Facilities shall have the responsibility of devising
and filing with the VILLAGE a contingency plan
satisfactory to the VILLAGE for the immediate
notification of VILLAGE officials in the event of an
emergency.
SECTION 18.4. PERMITTED USES
(a) Individuals and/or Facilities may request the VILLAGE to
permit additional land uses in the DISTRICT.
(b) All requests shall be in writing either on or in substantial
compliance with forms to be provided by the VILLAGE and shall include
an environmental assessment report prepared by a licensed
environmental engineer.
Said report shall be forwarded to the VILLAGE ENGINEER
and/or designee(s) for recommendation and final decision by the
VILLAGE BOARD.
(c) The Individual/Facility shall reimburse the VILLAGE for all
consultant fees associated with this review at the invoiced amount
plus administrative costs.
(d) Any permitted uses shall be conditional and may include
required environmental and safety monitoring consistent with local,
state and federal requirements, and/or bonds and/or sureties
satisfactory to the VILLAGE.
SECTION 18.5. ENFORCEMENT
(a) In the event the individual and/or facility causes the
release of any contaminants which endanger the DISTRICT, the activity
causing said release shall immediately cease and a cleanup
satisfactory to the VILLAGE shall occur.
(b) The individual/facility shall be responsible for all costs
of cleanup, VILLAGE consultant fees at the invoice amount plus
administrative costs for oversight, review and documentation.
1. The cost of VILLAGE employees' time associated in any
way with the cleanup based on the hourly rate paid to
the employee multiplied by a factor determined by the
-3-
Figure 5-10. Cottage Grove wellhead protection resolution and ordinance (continued).
85
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2,
3,
VILLAGE representing the VILLAGE'S cost for expenses,
benefits, insurance, sick leave, holidays, overtime,
vacation, and similar benefits.
The cost of VILLAGE equipment employed.
The cost of mileage reimbursed to VILLAGE employees
attributed to the cleanup.
(c) Following any such discharge the VILLAGE mav require
additional test monitoring and/or bonds/sureties as outlined in
Section 184.4(d)
(d) Enforcement shall be provided pursuant to Section 25.04 of
the Code.
SECTION II.
SECTION III.
Adopted this
CONFLICT AND SEVERABILITY. Section 25.02 of the
Municipal Code of the Village of Cottage grove
applies to this ordinance.
EFFECTIVE DATE. This ordinance shall take effect
upon passage and posting as provided by law.
"*" day of
si f
1992.
BY ORDER OF THE VILLAGE BOARD
VILLAGE OF COTTAGE GROVE
Attest:
Requested By:
Drafted By:
Approved As to
Form By:
Leighton W. Boushea, Village Attorney
Leighton W. Boushea, Village Attorney
-4-
Rgure 5-10. Cottage Grove wellhead protection resolution and ordinance (continued).
86
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village." The ordinance was drawn up in accordance with
authority granted by the Wisconsin Legislature in 1983,
Wisconsin Act 410, specifically adding ground water pro-
tection to the statutory authority of municipal planning
bodies. The ordinance determined that lands within the
Wellhead Protection District be subject to land use and
development restrictions, with use limited to parks, play-
grounds, wildlife areas, nonmotorized trails, and munici-
pally sewered residences. Existing uses of developed lots
are required to meet all local, state, and federal safety
and environmental requirements, and the owners are re-
quired to devise and file an emergency contingency plan
with the village. Additional land uses in the district are
subject to a permitting process. Actions in the case of
release of contaminants endangering the district are de-
termined at the cost of the individual/facility causing the
release, and enforcement is provided pursuant to Section
25.04 of the Village Code.
Approach Used to Plan for the Future
The village ordinance extends management of the village
ground water into the distant future. In the short term,
remediation efforts continue at the two sites where ground
water has been compromised by contaminants. Well #1,
still active as of July 1992, will be shut down as soon as
construction of Well #3 is complete. It will be kept as a
test well. It is expected that Wells #2 and #3 will serve
the growing population of the village. To ensure that future
needs are met, the technician would like to see the village
develop a contingency plan in the event of contamination
of either of these wells.
Education continues to be an important piece of Cottage
Grove's current and future management plan. Believing
that preventive action is more effective than remediation,
the utility director is gathering materials to educate home-
owners on residential contamination sources. Because
the village asked that surrounding communities and the
state take voluntary measures to prevent ground .water
contamination that may affect Cottage Grove, the utility
director is taking steps to encourage as much education
and voluntary participation as possible within the village
community. She feels that the viltege will need to rely as
much on voluntary action as legal compliance to protect
its water. She also foresees that the Wisconsin State
Groundwater Protection Program will require an educa-
tion initiative as part of local ground water protection pro-
grams and views the education program as part of the
village's compliance.
Conclusion
The village of Cottage Grove was unusually active in the
development of a ground water protection program. Its
proactive approach was in part a response to the tangible
threats to its drinking water supply. The village benefited
greatly from the expertise and leadership of its utility di-
rector and the WRWA technician. The WRWA program
enabled the village to tap expertise that would otherwise
have been beyond its means. "We were considered either
too small or too affluent to qualify for most grant pro-
grams," noted Village Clerk Sue Kettinger. The utility di-
rector estimates that the services provided by the
technician would have cost the community between.
$25,000 and $30,000 if they had hired an engineering
consultant.
The success of the Cottage Grove initiative can also be
linked to the open lines of communication established in
the village from the beginning. The planning team actively
sought input from the business and residential sectors of
the community and incorporated suggestions into the final
document. In addition, the team tapped the network of
knowledge and experience from other communities and
state resources such as the University of Wisconsin Ex-
tension Service and the Wisconsin Department of Natural
Resources. The willingness of local businesses, in par-
ticular Hydrite and Avganic, to participate in the estab-
lishment of a ground water protection program was also
an essential part of Cottage Grove's success.
87
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CASE STUDY THREE: Enid, Oklahoma
Description of Enid
Located 85 mi northwest of Oklahoma City, Enid is the
largest ground water user in the state. The city's water
supply serves about 60,000 people, including a metro-
politan population of approximately 46,000 (which in-
cludes Vance Air Force Base and Phillips University) as
well as citizens in neighboring rural communities. Enid's
drinking water is supplied by 153 wells located in five
wellfields drawing from two aquifers. The wellfields are
located in four counties, with the Cimarron River crossing
one of the wellfields. The Cimarron River Terrace Aquifer
provides 80 percent of the water supply, and the Enid
Isolated Terrace Aquifer provides 20 percent. Water qual-
ity in the two aquifers is considered to be very high.
Average water usage is 11 million gallons per day (mgd),
with peak demand at 18 mgd; the water supply system
capacity is 27 mgd. Well water treatment includes chlori-
nation and fluoridation.
Enid's economy is based primarily on agriculture, oil and
gas activities, and manufacturing. In addition, the city
serves as a center of trade, health care, and retirement
for the surrounding rural area. Several railroad lines and
two highways pass through Enid.
Approach Used to Form a Community
Planning Team
The wellhead protection planning team is composed of
members of several city departments, including the Di-
rector of Public Works, who has an engineering back-
ground in ground water resources and geology; members
of the Engineering Department; and staff from the Water
Production Department with geotechnical expertise. The
Oklahoma Water Resources Board provides useful tech-
nical assistance for the wellhead protection program. The
planning team spent 6 months preparing a "total aquifer
management plan," which was completed and approved
by the City Council in March 1990.
Mechanisms also were developed for public participation
in wellhead protection planning and program review. In-
terested citizens and civic and environmental organiza-
tions in the area reviewed and critiqued proposed
program elements. City Council public meetings served
as a forum for this review process.
Approach Used to Delineate the Wellhead
Protection Area
The wellhead protection planning team reviewed existing
data, including water quality test results, water production
records, drillers' logs, test hole data, geologic and hydro-
logic reports and maps, and potential contaminant source
inventories. Field surveys were then conducted to obtain
missing information. The team mapped the data as over-
lays onto a digital base map and developed a geographic
information system (GIS) to organize the data.
The area consists of alluvium (fine-grained, unconsoli-
dated soils deposited by a stream or other body of
running water), terrace deposits (coarse-grained, uncon-
solidated soils, including sand dunes), and consolidated
shale and sandstone. The hydraulic conductivities and
specific yields of these soils are given in Table 5-1. Figure
5-11 shows the aquifers and recharge areas for the Enid,
Oklahoma, area. Figure 5-12 illustrates ground water flow
and elevations in Enid's Cleo Springs wellfield area.
Initially, the project team used semianalytical methods
developed by the Oklahoma Water Resources Board to
delineate the five wellfield boundaries. Team members
then refined these delineations by using the U.S. Geo-
logical Survey (USGS) computer programs MODPATH
and MODFLOW, which allowed aquifer conditions, such
as ground water head and velocity and the area of influ-
ence for each well, to be modeled.
One- and 10-year time of travel criteria were used. The
10-year wellhead protection area was used to include
ground water protection from oil injection wells in the
area. (These wells were used by local oil companies to
recover additional oil from old oil fields that were not
yielding enough oil.) The wellhead protection team stipu-
lated to the oil companies that within the 10-year wellhead
delineation area, only fresh water could be used in the
injection wells; outside of the 10-year delineation area,
the oil companies could use salt water in their injection
wells. Figure 5-13 shows wellhead protection area deline-
ations for several wells in Enid's Cleo Springs wellfield.
Table 5-1. Hydraulic Conductivity and Specific Yield Values for Soil Types in Enid's Cleo Springs Wellfield
Hydraulic Conductivity (gal/d-ft2) Specific Yield
Lithology
Shale
Sandstone
Alluvial deposits
Alluvial deposits
Range
5x 10'3-5x10'7
1 x 101 -8X1CT4
5.1 x103- 1.3 X102
4.0 x 103- 1.1 x103
Average
1.6x 103
2.7 x 103
Range
1.3 x 10'1
2.2 x 10'1
- 1.8x 10'2
-4.8x 10'3
Average
6.4 x 10'2
1.1 xicr1
Source: Enid Municipal Authority. Well Field Analysis. November 1982.
88
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Key
0 Case Study Wellfield
Not To Scale
N
:,«c'-,•-',,! Unconsolidated Aquifers and i
"'-'•' v ; ; Recharge Areas •-—
Consolidated Aquifers
i Known Recharge Areas to
—'•'• Consolidated Aquifers
| Potential Recharge Areas to
-•' Consolidated Aquifers
Source: Maps Showing Principal Ground-Water Resources and Recharge Areas in Oklahoma
Sheet 1 — Unconsolidated Alluvium and Terrace Deposits; Sheet 2 — Bedrock Aquifers and Recharge Areas. Oklahoma Geological Survey.
Figure 5-11. Aquifer and recharge areas for the Cleo Springs Wellfield.
89
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Diagrammatic seclion showing the occurrence and movement of ground water in the
Enid quadrangle. Arrows indicate the general direction of water movement.
Ground water discharge points are seeps and streams-
Key
N
Ground Water Contours
Direction of Ground Water Flow
Existing Water Production Wells
/NotTo,$ca{e-
Rgure 5-12. Map showing ground water flow and elevations in Enid's Cleo Springs Wellfield.
90
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Key
1-Year Wellhead Protection Areas
Water Production Well
N
-10-Year Wellhead Protection Area
Not To Scale
Figure 5-13. Wellhead delineations for selected wells in Enid's Cleo Springs Wellfield.
91
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Approach Used to Identify and Locate
Potential Sources of Contamination
Implementation of a wellfield management system and
wellhead protection program.
The program team began with existing data bases from
federal and state agencies that provided information on
sources such as underground storage tanks and on local
soil conditions. This information was augmented with field
surveys of sources within each wellfield boundary to pro-
vide a comprehensive data base of potential contamina-
tion sources. Figure 5-14 presents a Source Vulnerability
Survey form developed by the State of Oklahoma and
used by Enid to help identify potential contamination
sources.
The team also has developed an aquifer vulnerability
index using EPA's DRASTIC methodology to determine
susceptibility of ground water to contamination from leaks
or spills. The index includes parameters such as depth
to water table, soil type, recharge rate, topography, and
land uses. The team plans to incorporate this index into
a broader risk assessment system that could be inte-
grated with other federal and state programs, such as
SARA Title III and state ground water standards.
Potential sources of ground water contamination to Enid's
wells include oil and gas drilling activities, such as pro-
duction, storage, and transport through pipelines and
trucks; injection wells; herbicide and fertilizer use; irriga-
tion wells; livestock wastes; surface waters; septic sys-
tems; municipal wastewater disposal lagoons; active and
inactive municipal and private landfills; wastewater treat-
ment and land application facilities; a RCRA-approved
hazardous waste disposal facility; underground and
aboveground storage tanks; cemeteries; and vehicle and
rail spills.
Approach Used to Manage the Wellhead
Protection Area
Enid's aquifer management program involves a 10-phase
plan:
• Compilation and review of existing data.
• Development of base mapping.
• Data acquisition.
• Development of a hydrologic model.
• Delineation of wellhead protection areas.
• Development of a data base of potential contamination
sources.
• Review of existing practices of potential polluters and
of relevant federal, state, and local regulations.
• Public education and public participation in policy and
regulation review.
• Initiation of changes, if required.
Public education is a key element in Enid's wellhead
protection program. The program emphasizes public
awareness in part because Enid and surrounding rural
communities do not have regulatory authority—most of
the wellfields are located in rural areas outside of Enid,
and no zoning statutes exist in these rural areas. The
project team has found the public awareness approach
to be effective.
The public education component consists of both struc-
tured and informal strategies. The project team meets in
groups and individually with targeted populations such as
individual landowners, farmers, and oil and gas field per-
sonnel. Farmers in the area are already well educated
about environmental transport and fate of contaminants
in the subsurface and have been receptive to the impor-
tance of wellhead protection. Oil and gas fields share the
same geographic area as the wellfields; discussing well-
head protection with oil and gas field personnel is impor-
tant, since they maintain equipment and are the first to
respond to problems (e.g., leaks). Wellhead project team
members met with oil and gas staff to discuss the well-
head protection program, including what to do if a leak
occurs and whom to contact. A successful informal net-
work continues between wellhead protection and oil and
gas personnel.
Potential surface water contamination of the wells from
the Cimarron River prompted the team to expand ground
water monitoring as part of its wellhead protection pro-
gram. A RCRA-authorized hazardous waste disposal unit
exists 15 miles from one of Enid's wellfields. The wellhead
protection team has since determined that the hazardous
waste disposal site is a minimal threat, since it is not
connected hydrologically to the aquifer that serves the
drinking water wells. The Cimarron River, however, is a
gaining stream—that is, ground water discharges to the
river. Changes in hydrogeologic conditions (e.g., climatic
changes or pumping) could reverse the water flow gradi-
ent, resulting in the river recharging ground water. If this
were to occur, the river would become a potential source
of contamination if any substances from the hazardous
waste site found their way into the river. Therefore, the
wellhead protection team decided that, although it is un-
likely that reverse water flow between the Cimarron River
and ground water will ever occur, monitoring of ground
water elevation is important in this situation to protect
ground water quality because of the hydrologic relation-
ship between the Cimarron River and the area's ground
water.
Previously, ground water monitoring included quarterly
measurements of ground water elevation and measure-
ments of ground water quality every 5 years. The ex-
panded ground water monitoring program now includes
monthly measurements of ground water elevation in 175
92
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SOURCE VULNERABILITY SURVEY
(Complete for Every Source)
SYSTEM:.
CNTY:
ID
DATE:
SOURCE NAME OR WELL*: _
LEGAL LOCATION: 4 .
FINDING LOCATION:
Sec
CONTACT PERSON:
WELL DEPTH:
TWP RGE
M
LOCAL FEATURES: Check all local features that may have affected source water quality within the last 25
years within each approximate distance range from the referenced source.
FEATURE
Residential Features
Septic field
Garden
School
City Park
Golf Course
Commercial Features
Gas Station
Dry Cleaner
Car Wash
Road
Industrial Features
Chemical Plant
Refinery
Chemical Storage
Airport
Railroad
Military Base
Pipeline
Fuel Storage
Waste Disposal Pond
Landfill
Oil Well
Injection Well
LESS THAN
100 FT
100 FT to
1/4 MILE
COMMENTS
*Please complete Ag Chemical Usage form
*Please complete Ag Chemical Usage form
Figure 5-14. State survey used by Enid to identify potential sources of contamination.
93
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••••••i^HplpBllpppllplpHpHppBBSKHHnnifflSHB
•— aW<-m<~C VULIVtKMtSILI 1 T bUKVfcY •
•••:,-•-••-: :-v-:.?;<.;*i;:-,o;y;;;,si-:!r;.;v-v::^;^r^vs:::--i:-:-^B
LOCAL FEATURES (continued): Check all local features that may affect groundwater quality which occur
within each approximate distance range from the referenced well.
FEATURE
Agricultural Features
Irrigated Cropland
Non-irrigated Cropland
Pasture
Orchard/Nursery
Feedlot
(confined animals)
Rangeland
Forestland
Surface Water Features
River, Stream
(Perennial/Ephemeral)
Irrigation Canal
(Lined/Unlined)
Drainage Ditch
Lake/Pond
Salt Flat
Mine/Quarry
Electrical substation/
transformer storage
LESS THAN
100 FT
100 FT to
1/4 MILE
COMMENTS
*Please complete Ag Chemical Usage form
'Please complete Ag Chemical Usage form
*Please complete Ag Chemical Usage form
'Please complete Ag Chemical Usage form
'Please complete Ag Chemical Usage form
*Please complete Ag Chemical Usage form
'Please complete Ag Chemical Usage form
*Please complete Ag Chemical Usage form
*Please complete Ag Chemical Usage form
Estimate the percentage of each general class of land use within each distance range from the well.
FEATURE
Residential
Commercial
Industrial
Agricultural
Other (Explain)
LESS THAN
100 FT
100 FT to
1/4 MILE
COMMENTS
Comments:
Source Vulnerability Survey Cor
Title:
npleted by:
Date:
Figure 5-14. State survey used by Enid to identify potential sources of contamination (continued).
94
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observation and production wells with 17 continuously
rarnrHing olopfrnnic w?tt»r IPX/P! maters anri thrpe rnntinu-
gency plans for different levels of risks will be developed.
In the unlikely event that the water flow gradient between
ously recording precipitation gauges. The elevation read-
ings let the wellhead protection team know whether the
water flow gradient is steady or is being reversed.
The Enid League of Women Voters also played an im-
portant role in the municipality's public education pro-
gram. The local league produced and distributed
information on wellhead protection through newspapers,
newsletters, radio, and television. Some of these materi-
als were financed through a grant the local league re-
ceived from the League of Women Voters Education Fund
and the U.S. Environmental Protection Agency; other
publicity was free (e.g., public service announcements).
Approach Used to Plan for the Future
A contingency plan has been conceptualized and is being
developed. The contingency plan is a geological-based
risk analysis for each wellfield based on all the data ac-
quired through the wellhead protection program. Contin-
the Cimarron River and ground water ever reversed, the
city would take wells nearest the river out of service.
Since Enid now has 60 percent more production capacity
than is currently used, alternative wells already exist
within the system if they are needed. If necessary, the
city has sufficient water rights to develop new wells.
Conclusion
Enid was fortunate to have municipal personnel with ex-
pertise in hydrogeology to develop a sophisticated well-
head protection program for its 153 drinking water wells.
The wellhead protection planning team also drew upon
federal, state, and local resources (e.g., data bases,
technical assistance, and citizen organizations). The city
also established detailed management and contingency
plans to successfully implement its wellhead protection
program.
95
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CASE STUDY FOUR: Descanso Community
Water District. San Diego County. California
tional burdens on the district's ground water in two ways:
first, through increased potable water demands and, sec-
Descrtption of the Descanso Community
Water District
The Descanso area is located along the Descanso and
Sweetwater Rivers in the south central region of San
Diego County in California (see Figure 5-15). The Sweet-
water is the major river in the area and provides an im-
portant source of recharge for the area's aquifers.
Descanso covers an area of approximately 8 square
miles in the upper Sweetwater River Basin. Most of the
ground water pumped from the upper basin occurs in this
area. The northern portion of the Descanso area consists
of Cuyamaca State Park and is protected from develop-
ment (see Figure 5-16). The Descanso area remains
mostly undeveloped, while existing development is
largely residential. Its population was estimated in 1988
at 1,400 full-time residents. These residents depend com-
pletely on privately owned or public wells to satisfy their
water supply needs.
Because a large portion of the land in Descanso remains
undeveloped, the potential for increased residential de-
velopment is high. Further development will place addi-
ond, through increased risk of ground water contamina-
tion, because the primary method of sewage disposal in
the area is through the use of septic systems.
The Descanso Community Water District (DCWD) serves
the water supply needs of the Descanso area and is
responsible for the development and implementation of a
wellhead protection program for the area. DCWD main-
tains seven public supply wells in the area and provides
water to approximately 900 residents.
The area's aquifers consisted of a thin layer (averaging
50 ft) of weathered bedrock or regolith overlying meta-
morphic and granitic bedrock. Most of the ground water
pumped from existing wells is recovered from the regolith
layer. Ground water within the area generally flows toward
the rivers that run through the area. In 1988, ground water
storage in the regolith layer was estimated in the range
of 800 to 2,000 acre-ft, and 300 to 3,000 acre-ft in the
underlying bedrock (USGS, 1990). These estimates do
not account for the physical limitations that inhibit recov-
ering ground water; the actual recoverable ground water
is much less. Surface altitude ranges from 3,300 to 4,100
ft above sea level.
RIVERSIDE COUNTY
SAN DIEGO COUNTY
Descanso
• STUDY AREA
0 10 20
^^^^^^^^^^mBBH
scale (miles)
Figure 5-15. Locus map of the Descanso area, San Diego County, California. Prepared by Horsley & Witten, Inc.
96
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; Location of Streamf low
> Measurement Sites
~ ~ ' Descanso Community Water District
Measurement Site and Number
Boundary of Study Area
Boundary of Upper Sweetwater
River Basin
Figure 5-16. Descanso area, Upper Sweetwater River Basin, and
location of streamflow measurement sites. Prepared by Horsley & Witten, Inc.
There are several types of wells in the DCWD, including
shallow wells in sand, gravel, and decomposed granite,
and deep bedrock wells. The yield from metamorphic and
granitic bedrock is a function of fracturing (Merriam,
1951). Most of the bedrock wells in the Descanso area
are less than 500 ft deep, which probably indicates the
depth of open and hydraulically connected fractures
(USGS, 1990). The depth to ground water and water table
altitude was investigated in several of Descanso's wells
during a 1988 water resource investigation of the area by
the United States Geological Survey. This study revealed
that the water level depth in the study wells ranged from
2 ft below ground level in river valleys to around 46 ft
below ground level on hillsides (USGS, 1990).
This investigation also estimated that ground water re-
charge from precipitation and streamflow in the Descanso
area was approximately 1,000 acre-ft in 1988, while well
pumpage was approximately 170 acre-ft in the same year.
Overview of Wellhead Protection Issues
In general, the water quality from Descanso's seven wells
is acceptable for domestic consumption, although some
wells have yielded water samples with concentrations of
iron and manganese exceeding California maximum con-
taminant levels; however, these levels are based on aes-
thetic criteria and are not toxic levels. Table 5-2 presents
Descanso's annual water quality report.
At this time, there is no known contamination in any of
the DCWD wells. Several potential sources of contami-
nation exist, however, particularly septic system leachate.
Because there are no wastewater treatment sewers in
the area, all residential dwellings use septic systems to
handle wastewater. Pollutants that are released into the
septic systems (primarily nitrogen, nitrates, and house-
hold cleaning products) ultimately can migrate into sur-
rounding aquifers. A preliminary evaluation of the septic
97
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Table 5-2. Concentrations of Selected Constituents in 10
Samples from Wells in and near the Descanso Area, 1988,
and California Maximum Contaminant Levels (MCLs) for
Domestic Drinking Water
Constituent
Median Range
MCL
Microsiemens per centimeter at
25°C
Electrical 522
conductivity
pH 7.6
Calcium, 50
dissolved
Magnesium, 14
dissolved
Sodium, dissolved 30
384-685 900-1,600
Standard units
7.3-8.1 NA
Milligrams per liter
32-82 NA
8-27
NA
Potassium,
dissolved
Alkalinity, total
field
Sulfate, dissolved
Chloride,
dissolved
Fluoride,
dissolved
Silica, dissolved
Dissolved solids
sum of
constituents
Nitrite plus
nitrate, dissolved
as nitrogen
Boron, dissolved
Iron, dissolved
Manganese,
dissolved
3.8
142
33
42
.30
42
322
.20
30
37
62
1.5-5.9
90-235
12-91
27-100
0.10-0.40
28-76
247-424
<0. 10-6.6
<10-60
4-2,800
<1-280
NA
NA
240-5001
250-5001
1.4-2.42
NA
500-1,000'
10
NA
300
50
'No fixed consumer acceptance contaminant level has been estab-
lished. The lower constituent concentrations are recommended, and the
higher levels are acceptable if it is neither reasonable nor feasible to
provide more suitable waters.
2Depends on annual average of maximum daily air temperature.
Source: U.S. Geological Survey, 1990.
system impacts was conducted in the area using a nitro-
gen loading model (U.S. EPA, 1991e). It found that cur-
rent average nitrate-nitrogen concentrations in the ground
water are 2.1 to 3.8 mg/liter. Under drought conditions,
based on the existing level of development, concentra-
tions would be well below EPA's 10 mg/liter maximum
contaminant level (MCL). These concentrations indicate
that septic systems are not having a critical impact on
area ground water quality at this time. An analysis of the
existing zoning ordinance demonstrated that future po-
tential development could result in nitrate-nitrogen con-
centrations in excess of the MCL at one well and near
the MCL at another well. Proposed zoning changes were
also evaluated using the nitrogen loading model.
Approach Used to Form a Community
Planning Team
As part of EPA's Wellhead Protection Program, EPA Re-
gion 9 initiated local training in rural communities to assist
in the design and implementation of wellhead protection
plans. Region 9 obtained assistance from the California
Rural Water Association (CRWA) to identify localities to
participate in the project. Descanso and two other com-
munities were selected for participation. EPA Region 9
funded the research and other project support work nec-
essary for developing wellhead protection plans in these
communities.
In the case of Descanso, establishing a community plan-
ning team was not the first step of the wellhead protection
process. Representatives from EPA Region 9 and Horsley
Witten Hegemann, Inc. (HWH), the consulting firm hired
by Region 9 to assist in the development of the wellhead
protection plan, developed a preliminary wellhead protec-
tion plan for Descanso. The plan delineated the wellhead
protection areas, identified potential sources of contami-
nation, and outlined strategies for wellhead protection.
This preliminary plan was presented at a meeting of the
DCWD Board of Directors in July 1991. Although EPA and
CRWA played a vital role in the design of a wellhead
protection program, the DCWD Board of Directors had
primary responsibility for determining what type of action,
if any, would be taken within the water district to protect
ground water quality.
Participants in the July meeting included a hydrologist
from HWH, a representative from San Diego County, a
hydrogeologist, the Local Planning Group (which is an
advisory group to the County Board of Supervisors), and
the DCWD Board of Directors. Although this group of
participants included people who were not members of
the local community, the group did act as the "community
planning team" in that it included the people who devel-
oped the plan, as well as the people who decided whether
to implement the plan.
The individuals on the community planning team had the
following responsibilities: the representatives from HWH
acted as expert consultants to Descanso; the repre-
sentative from San Diego County served as a liaison
between the team and the county government and as-
sisted the team by providing advice when possible; the
hydrogeologist provided the team with expert advice on
98
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issues related to delineation of the wellhead protection
area and potential sources of ground water contamina-
tion; the Local Planning Group functioned as an advisory
group to the County Board of Supervisors and also rep-
resented the citizens of Descanso in the decision-making
process; and the DCWD Board of Directors had the final
authority to decide if and/or how the proposed plan would
be implemented.
Approach Used to Delineate the Wellhead
Protection Area
HWH contacted Town of Descanso and DCWD officials
to obtain any existing information that could be used to
delineate the wellhead protection area. The information
made available to HWH included water well drillers' re-
ports showing the soils and rock features of the Descanso
wells, well pump tests, a 1990 USGS-Water Resources
Investigations Report giving information on the hydro-
geologic setting of the area, land use maps, and DCWD
water quality reports. HWH used this information to de-
lineate the wellhead protection area of two major wells
currently in operation in Descanso. This was accom-
plished by using the Theis (1935) solution, a set of equa-
tions allowing calculation of the drawdowns on a water
table that occur due to a pumping well, and by using flow
net analysis and darcian ground water velocity calcula-
tions.
The 1990 USGS report described the water levels in 21
wells measured periodically in 1988. From information
obtained from the Town of Descanso and USGS, HWH
developed a regional water table showing ground water
flow directions throughout the community (Figure 5-17).
A pumping rate of 75 gal/min was selected for both of the
wells in the study, and values of 360 ft^/day for transmis-
sivity and 0.02 for storage capacity (storativity) were cho-
sen from the USGS report for input into the Theis
equation.
This set of equations yielded drawdown values that were
subtracted from the regional water table map to determine
the configuration of the pumped water table. Table 5-3
shows the drawdown calculations for different pumping
periods. This analysis examined the drawdown that would
occur within the water table during a 1- and 5-year
drought period, under zero recharge conditions, with con-
tinuous pumping from storage within the aquifer.
Wellhead protection area boundaries were defined using
time of travel criteria thresholds. The chosen thresholds
were the 1- and 5-year time of travel zones. These were
PUBLIC SUPPLY WELL •
Water Table Map
Descanso Community Water District
Water Level Measurements Taken: May, 1988
Observation well with water level data
Direction of ground water flow
scale (feet)
Figure 5-17. Descanso water table map showing flow directions. Prepared by Horsley & Witten, Inc.
99
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Table 5-3. Theis Equation Calculations for Descanso Valley
Q = well discharge (f^/day)
T = transmissivity (ffrday)
t = time pumping (days)
S = storativity
r = distance to well (ft)
100
200
300
500
1000
2000
Q = well discharge (ft3/day)
T = transmissivity (ff/day)
t = time pumping (days)
S = storativity
r = distance to well (ft)
100
200
300
500
1000
2000
Q = well discharge (ft3/day)
T = transmissivity (fftday)
t = time pumping (days)
S = storativity
r = distance to well (ft)
100
200
300
500
1000
2000
14438
360
365
0.02
u
0.000380518
0.00152207
0.003424658
0.009512938
0.03805175
0.152207002
14438
360
120
0.02
u
0.001157407
0.00462963
0.010416667
0.028935185
0.115740741
0.462962963
14438
360
1825
0.02
u
7.61035E-05
0.000304414
0.000684932
0.001902588
0.00761035
0.0304414
Wu
7.25
6
5.09
4
2.75
1.52
Wu
6.2
4.83
4.04
3
1.7
0.56
Wu
8.93
7.53
6.75
5.7
4.32
2.96
u = (r)(r)(S)/4(T)(t)
s + Q(W)(u)/4T;i
s = drawdown (ft)
23.15
19.16
16.25
12.77
8.78
4.85
s = drawdown (ft)
19.80
15.42
12.90
9.58
5.43
1.79
s = drawdown (ft)
28.51
24.04
21.55
18.20
13.79
9.45
Source: U.S. EPA, 1991e.
100
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calculated using flow net analysis and darcian ground
water vfilnrijy regulations. Thfi 1- and 5-year time of
to their existing allowable development densities accord-
ing to the zoning ordinance.
travel zones for each of the wells examined in the study
were delineated on a topographic map of Descanso. Fig-
ure 5-18 shows the wellhead protection areas delineated
for the two public supply wells in the Descanso area.
Approach Used to Identify and Locate
Potential Sources of Contamination
To determine existing and potential sources of contami-
nation a survey of the Descanso area was undertaken.
Survey activities included studying USGS topographic
maps, driving through the local neighborhood to identify
high-risk activities, and interviewing members of the
DCWD Board of Directors and their staff. The survey
confirmed that the predominant sources of potential
ground water contamination in the Descanso area are
residential septic systems. Given the absence of a local
sewer network and the potential for further residential
development in Descanso, septic system impacts needed
to be closely evaluated.
A preliminary estimation of septic system impacts based
on a 1990 USGS hydrologic budget of the area concluded
that Descanso's average nitrate-nitrogen ground water
concentrations are currently below the federal drinking
water standard. This situation could change, however, if
Descanso's ground water recharge zones are developed
At the time of this study, the San Diego County Depart-
ment of Planning and Land Use was proposing an
amendment to the existing zoning ordinance. This change
proposed down-zoning existing residential zones within
Descanso to reduce allowable development densities.
Figure 5-19 was prepared by overlaying Descanso's zon-
ing district map over the wellhead protection areas of the
study wells. This map allowed HWH to determine the
development potential of the land within the delineated
wellhead protection areas. HWH used a nitrogen loading
model (Nelson et al., 1988) to investigate the effects of
potential development under the existing zoning in the
wellhead protection areas, as opposed to that under the
proposed zoning in the wellhead protection areas, on
nitrate-nitrogen concentrations within the study wells. The
results of this analysis suggest that the proposed zoning
changes would result in lower nitrate-nitrogen concentra-
tions in the study wells than if the existing zoning is up-
held (see Table 5-4).
Approach Used to Manage the Wellhead
Protection Area
Following the presentation of the proposed wellhead pro-
tection plan for Descanso at the July meeting of the
DCWD Board of Directors, the community took formal
Wellhead Protection Areas
Descanso Community Water District
0 2500
•===••1^
scale (feet)
Figure 5-18. Wellhead protection areas delineated for Descanso's drinking water.
Prepared by Horsley & Witten, Inc.
101
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Land Use / Zoning Map
Descanso Community Water District
Figure 5-19. Descanso's land use/zoning map overlaid on the map of Dcscanso's wellhead
protection area. Prepared by Horsley & Wltten, Inc.
action to set up a wellhead protection program and set
out to be a pilot program for the State of California. To
get the program started, a committee was established to
help implement wellhead protection measures within Des-
canso. Figure 5-20 presents an article that appeared in
a local community newspaper explaining the process of
wellhead protection to the public and inviting interested
members of the community to serve on the wellhead
Table 5-4. Results of Nitrogen Loading Analysis for
Descanso Area
Well #1
Existing
conditions
Current zoning
Proposed zoning
Well #2
Existing
conditions
Current zoning
Proposed zoning
73 dwellings
150 dwellings
99 dwellings
27 dwellings
107 dwellings
1 04 dwellings
6.2-7.9 mg/liter
11-13 mg/liter
7.8-9.5 mg/liter
3.4-5.1 mg/liter
8.3-10 mg/liter
8.1-9.7 mg/liter
Source: U.S. EPA, 1991e.
protection committee. This committee held regular public
meetings to discuss issues related to wellhead protection.
This public forum was used to educate Descanso resi-
dents about the aims of a wellhead protection program
and to allay community fears that the committee might
implement severely restrictive land use regulations.
Educating the Descanso community about the threat of
contamination to its wells is an important issue for the
Descanso wellhead protection committee. Informational
and educational materials on wellhead protection and
water conservation are available in the DCWD office. The
DCWD annual newsletter regularly contains articles on
water conservation and how to properly dispose of house-
hold toxic materials. In the future, the DCWD will hold
education workshops where hydrogeologists and sanitary
engineers can give detailed information to the community
on the geology of the public supply wells, the threats of
ground water contamination, and the implications of
household toxic waste mismanagement. In addition, the
committee is obtaining signs to inform individuals when
they enter wellhead protection areas. This will encourage
environmental awareness and familiarity with the concept
of wellhead protection.
102
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Descanso takes part in U.S. pilot project
to protect groundwater
Diana Saenger
Alpine Sun Writer
The community of Descanso has been chosen to
participate in a federal "Well Head Protection
Plan" project, and the water district has agreed
to implement the pilot program.
Representatives of the U.S. Environmental Pro-
tection Agency came to a Descanso Community
Water District board meeting to explain what the
project was and how it would work. An EPA study
of all existing wells and well sites in the Descanso
area revealed how much ground surrounding
each well would be needed to provide a five-year
buffer zone from pollution. That is, it would take
five years for pollution to penetrate from the
boundaries of the buffer zone to the well head.
Gale Ruffin, general manager of the Descanso
Water District, said the district became aware of
the project through Harry Brown from the EPA,
The Descanso district had been working with
Brown on improving its well sites and reservoir.
"Mr. Brown wants other districts to see what ef-
fect the pilot program will have on Descanso,"
said Ruffin. Ruffin was extremely pleased the
study was done by the EPA because it is very
expensive and saved the community a great deal
of money.
The program consists of seven steps: 1) organize
a staff for the program; 2} delineate the Well Head
Protection Area; 3} identify anything hazardous
in the ground such as septic or fuel storage and
identify proposed new developments; 4) develop
a contingency plan in case of hazards; 5) man-
agement of testing and looking at new well sites;
6} continue education; 7} make the public partici-
pants and placing of signs designating this is a
"Well Head Protection Area."
The next step for the district is to organize a
committee to get things going. Ruffin has been in
touch with a community in Texas that has the
program already working. If anyone is interested
in working on this committee, please call the
Water District at 445-2330.
Figure 5-20. This article appeared in the Alpine Sun, a Descanso local newspaper on August 21,1991. Source: U.S. EPA,
1991e.
The San Diego County Department of Planning and Land
Use was updating the Central Mountain Sub-Regional
Plan, which regulates zoning in the Descanso area, dur-
ing the time period of this case study. The EPA wellhead
protection study of the area indicated that the proposed
zoning changes would enhance wellhead protection in
Descanso by limiting potential development in the area.
The DCWD decided to take an active role in the public
hearing process regarding the proposed zoning changes;
members recognized that this was an ideal opportunity
to help regulate wellhead protection in the locality. They
submitted letters and supporting documentation to the
San Diego County Department of Planning and Land Use,
requesting that a special clause be incorporated into the
updated zoning ordinance to ensure that no source of
potential contamination be permitted in a wellhead pro-
tection area. They were successful in this endeavor and
the updated regulations will contain such a clause.
Approach Used to Plan for the Future
As a result of a statewide depressed economic climate,
Descanso is not faced with the prospect of heavy devel-
opment that seemed imminent a couple of years ago.
However, DCWD has continued to expand and develop
its wellhead protection program and is committed to pro-
tecting Descanso's ground water from contamination.
The DCWD has applied for federal assistance under
EPA's Wellhead Protection Demonstration Project to fur-
ther develop and implement Descanso's wellhead protec-
tion program. If the application is successful, DCWD will
use the allocated funds to delineate the WHPAof its major
well, site another well, and perform a nitrogen loading
103
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analysis of an area where a major development is pro-
oosed. TheseJunds will also allow the DCWD committee
applying the five-step process to wellhead protection.
However, the main impetus in developing anri implsmftnt-
to continue its efforts to educate the Descanso community
about the daily threat of ground water contamination.
In regard to contingency planning, Descanso is fortunate
to have wells pumping from two different aquifer systems,
the Sweetwater and Descanso river valleys. If major con-
tamination of one aquifer occurs, the community can fall
back on the other.
Conclusion
Wellhead protection in Descanso followed an unusual
path in that the U.S. EPA Region 9 initiated the program,
with the help of consultants and the California Rural
Water Association, by providing "hands on" training in
ing the area's wellhead protection program came from the
DCWD. EPA and its consultants developed a preliminary
plan delineating wellhead protection areas for two of the
area's main wells, investigated potential sources of con-
tamination, and suggested possible management strate-
gies. DCWD then organized a committee to implement
wellhead protection strategies and began the process of
protecting Descanso's ground water in earnest at the
local level.
The DCWD committee recognizes the need for wellhead
protection and is committed to establishing a comprehen-
sive, effective program to protect the community's valu-
able ground water resource.
104
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Chapter 6
Resources for Additional Information
1. Publications
Many documents are available on the subjects of ground
water and wellhead protection. The following publications
(in addition to those listed under "References") may be
useful to your community in establishing a wellhead pro-
tection program.
Technical Guides to Ground Water
Contamination and Wellhead Protection
(including STEP ONE—Forming a
Community Planning Team)
The following publications provide relatively nontechnical
overviews of ground water and wellhead protection.
Born, S.M., D.A. Yanggen, and A. Zaporozec. 1987. A Guide
to Groundwater Quality Planning and Management for
Local Governments. Special Report 9, 92 pp. Wisconsin
Geological and Natural History Survey, 3817 Mineral
Point Rd., Madison, Wl.
Central Connecticut Regional Planning Agency. 1981. Guide
to Groundwater and Aquifer Protection. Bristol, CT.
Community Resource Group, Inc. 1992. The Local
Decision-Makers' Guide to Groundwater and Wellhead
Protection. 16 pp. Available from Rural Community
Assistance Program offices.
Concern, Inc. 1989. Groundwater: A Community Action
Guide. Washington, DC, 22 pp.
Gordon, W. 1984. A Citizen's Handbook for Groundwater
Protection. Natural Resources Defense Council, New
York, NY.
Hall and Associates and R. Dight. 1986. Ground Water
Resource Protection: A Handbook for Local Planners
and Decision Makers in Washington State. Prepared for
King County Resource Planning and Washington
Department of Ecology, Olympia, WA.
Harrison, E.Z. and M.A. Dickinson. 1984. Protecting
Connecticut's Groundwater: A Handbook for Local
Government Officials. Connecticut Department of
Environmental Protection, Hartford, CT.
Hrezo, M. and P. Nickinson. 1986. Protecting Virginia's
Groundwater: A Handbook for Local Government
Officials. Virginia Water Resources Research Center,
Virginia Polytechnic Institute and State University,
Blacksburg, VA.
Massachusetts Audubon Society. 1984-1987. Ground Water
Information Flyer Series. Groundwater and
Contamination: From Watershed into the Well (#2,
1984); Mapping Aquifers and Recharge Areas (#3,
1985); Underground Storage Tanks and Groundwater
Protection (#5, 1985); Local Authority for Groundwater
Protection (#4, 1985); Protecting and Maintaining Private
Wells (#6, 1985); Landfills and Groundwater Protection
(#8, 1986); Road Salt and Groundwater Protection (#9,
1987). Public Information Office, Lincoln, MA.
Massachusetts Department of Environmental Quality
Engineering. 1985. Groundwater Quality and Protection:
A Guide for Local Officials. Boston, MA.
Mullikin, E.B. 1984. An Ounce of Prevention: A Ground
Water Protection Handbook for Local Officials. Vermont
Departments of Water Resources and Environmental
Engineering, Health, and Agriculture, Montpelier, VT.
Murphy, J. n.d. Groundwater and Your Town: What Your
Town Can Do Right Now. Connecticut Department of
Environmental Protection, Hartford, CT.
New England Interstate Water Pollution Control Commission.
1989. Groundwater: Out of Sight Not Out of Danger.
Boston, MA.
Raymond, Jr., L.S. 1986. Chemical Hazards in Our
Groundwater, Options for Community Action: A
Handbook for Local Officials and Community Groups.
Center for Environmental Research, 468 Hollister Hall,
Cornell University, Ithaca, NY.
Sponenberg, T.D. and J.H. Kahn. 1984. A Groundwater
Primer for Virginians. Virginia Polytechnic Institute and
State University, Blacksburg, VA.
Texas Water Commission. 1989. The Underground Subject:
An Introduction to Ground Water Issues in Texas. Austin,
TX.
U.S. Environmental Protection Agency. 1987. Wellhead
Protection: A Decision Maker's Guide.
EPA/440/06-87/009 (NTIS PB88-111893), 24 pp. Also
available from EPA's Safe Drinking Water Hotline.
U.S. Environmental Protection Agency. 1987. An Annotated
Bibliography on Wellhead Protection Programs. Office of
Ground Water Protection, Washington, DC.
105
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U.S. Environmental Protection Agency. 1990. Citizen's Guide
to Ground Water Protection. EPA/440/6-9Q-n04, 33 pp.
Kreitler, C.W. and R.K. Senger. 1991. Wellhead Protection
Strategies for Confined-Aquifer Settings
Available from EPA's Safe Drinking Water Hotline.
U.S. Environmental Protection Agency. 1991. Protecting
Local Ground Water Supplies Through Wellhead
Protection. EPA/570/09-91-007, 18 pp. Available from
EPA's Safe Drinking Water Hotline.
U.S. Environmental Protection Agency. 1991. Why Do
Wellhead Protection? Issues and Answers in Protecting
Public Drinking Water Supply Systems.
EPA/570/9-91-014, 19 pp. Available from EPA's Safe
Drinking Water Hotline.
U.S. Environmental Protection Agency. 1992. Ground Water
Protection: A Citizen's Action Checklist.
EPA/810-F-91-002, 2 pp. Available from EPA's Safe
Drinking Water Hotline.
U.S. Geological Survey. 1976. A Primer on Ground Water.
Washington, DC.
Waller, R.M. 1988. Ground Water and the Rural Homeowner.
U.S. Geological Survey, Reston, VA.
STEP TWO—Delineating the Wellhead
Protection Area
The following publications provide technical information
on basic hydrogeology, methods for hydrogeologic char-
acterization, and wellhead protection area delineation.
Aller, L, T. Bennett, J.H. Lehr, and R.J. Petty. 1987.
DRASTIC: A Standardized System for Evaluating
Ground Water Pollution Potential Using Hydrogeologic
Settings. (NTIS PB87-213914), 641 pp. [Earlier version
EPA/600/2-85/018 published in 1985]. Also published by
National Water Well Association, Dublin, OH.
Berg, R.C., J.P. Kempton, and K. Cartwright. 1984. Potential
for Contamination of Shallow Aquifers in Illinois. Circular
532. Illinois State Geological Survey, Champaign, IL
Driscoll, F.G. 1986. Ground Water and Wells. Edward
Johnson Filtration Systems, St. Paul, MN.
Fetter, C.W. 1980. Applied Hydrogeology. Charles E. Merrill
Publishing Company, Columbus, OH.
Freeze, R.A., and J.A. Cherry. 1979. Groundwater. Prentice
Hall, Inc., Englewood Cliffs, NJ.
Heath, R.C. 1984. Ground-Water Regions of the United
States. 1984. U.S. Geological Survey, Water Supply
Paper 2242. U.S. Government Printing Office. For sale
by the Superintendent of Documents, U.S. Government
Printing Office, Washington, DC.
Heath, R.C. 1987. Basic Ground-Water Hydrology. U.S.
Geological Survey Water-Supply Paper 2220. 84 pp. For
sale by the Books and Open-File Reports Section, U.S.
Geological Survey, Federal Center, Box 25425, Denver,
CO.
Horsley, S. and M. Frimpler. In Press. Delineation of Wellhead
Protection Areas. Lewis Publishers, Chelsea, Ml.
EPA/570/9-91-008, 168 pp. Available from EPA's Safe
Drinking Water Hotline.
National Rural Water Association. 1990. Hiring an Engineer.
Rural and Small Water Systems Technical Bulletin,
Duncan, OK.
Quinlin, J.F., PL Smart, G.M. Schindel, E.G. Alexander, Jr.,
A.J. Edwards, and A.R. Smith. 1991. Recommended
Administrative/Regulatory Definition of Karst Aquifer,
Principles for Classification of Carbonate Aquifers,
Practical Evaluation of Vulnerability of Karst Aquifers,
and Determination of Optimum Sampling Frequency at
Springs. Ground Water Management 10:573-635 (Proc.
3rd Conf. on Hydrogeology, Ecology, Monitoring and
Management of Ground Water in Karst Terranes).
Available from the National Ground Water Information
Center (1-800-332-2104).
U.S. Environmental Protection Agency. 1986. Guidelines for
Ground-Water Classification Under the EPA
Ground-Water Protection Strategy. Office of Ground
Water Protection, Washington, DC.
U.S. Environmental Protection Agency. 1986. Criteria for
Identifying Areas of Vulnerable Hydrogeology Under
RCRA: A RCRA Interpretive Guidance, Appendix D:
Development of Vulnerability Criteria Based on Risk
Assessments and Theoretical Modeling.
EPA/530/SW-86-022D (NTIS PB86-224995).
U.S. Environmental Protection Agency. 1987. Guidelines for
Delineation of Wellhead Protection Areas.
EPA/440/6-87-010. Available from EPA's Safe Drinking
Water Hotline.
U.S. Environmental Protection Agency. 1988. Model
Assessment for Delineating Wellhead Protection Areas.
Office of Ground Water Protection, Washington, DC.
EPA/440/6-88-002 (NTIS PB88-238449), 267 pp.
U.S. Environmental Protection Agency. 1990. Hydrogeologic
Mapping Needs for Ground Water Protection and
Management: Workshop Report 1990.
EPA/440/6-90-002. Available from EPA's Safe Drinking
Water Hotline.
U.S. Environmental Protection Agency. 1991. Delineation of
Wellhead Protection Areas in Fractured Rocks. Office of
Ground Water and Drinking Water. EPA/570/9-91-009,
144 pp.
U.S. Environmental Protection Agency. 1991. A Modular
Semi-Analytical Model for the Delineation of Wellhead
Protection Areas, Version 2.0. Office of Ground Water
Protection, Washington, DC.
U.S. Environmental Protection Agency. 1991. Wellhead
Protection Strategies for Confined-Aquifer Settings.
Office of Ground Water and Drinking Water and Bureau
of Economic Geology, University of Texas at Austin. EPA
570/9-91-008.
U.S. Environmental Protection Agency. 1991. Delineation of
Wellhead Protection Areas in Fractured Rocks. Office of
106
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Ground Water and Drinking Water and Wisconsin
Geological and Natural I listory Survey.
STEPS FOUR AND FIVE—Managing the
Wellhead Protection Area and Planning for
the Future
The following publications may prove useful for develop-
ing approaches for controlling and preventing contamina-
tion in wellhead protection areas.
Born, S.M., D.A. Yanggen, A.R. Czecholinksi, R.J. Tiemey,
and R.G. Henning. 1988. Wellhead Protection Districts in
Wisconsin: An Analysis and Test Applications. Special
Report 10. Wisconsin Geological and Natural History
Survey, Madison, Wl, 75 pp.
Cantor, L.W. and R.C. Knox. 1986. Ground Water Pollution
Control. Lewis Publishers, Chelsea, Ml.
Cantor, L.W., R.C. Knox, and D.M. Fairchild. 1987. Ground
Water Quality Protection. Lewis Publishers, Chelsea, Ml.
Conservation Foundation. 1987. Groundwater Protection.
Washington, DC, 240 pp.
Curtis, C. and T. Anderson. 1984. A Guidebook for
Organizing a Community Collection Event: Household
Hazardous Waste. Pioneer Valley Planning Commission
and Western Massachusetts Coalition for Site Waste
Management, West Springfield, MA.
Curtis, C., C. Walsh, and M. Przybyla. 1986. The Road Salt
Management Handbook: Introducing a Reliable Strategy
to Safeguard People and Water Resources. Pioneer
Valley Planning Commission, West Springfield, MA.
DiNovo, F. and M. Jaffe. 1984. Local Groundwater
Protection: Midwest Region. American Planning
Association, 1313 E. 60th Street, Chicago, IL, 327 pp.
Freund, E.C. and W.I. Goodman. 1968. Principles and
Practices of Urban Planning. International City Managers
Association, Washington, DC.
Getzels, J. and C. Thurow (eds.). 1979. Rural and Small
Town Planning. American Planning Association,
Washington, DC.
Horsely, S. and J. Witten. 1992. Ground Water Protection.
Lewis Publishers, Chelsea, Ml.
Jaffe, M. and F.K. DiNovo. 1987. Local Groundwater
Protection. American Planning Association, Washington,
DC, 262 pp.
Kemp, L. and J. Erickson. 1989. Protecting Groundwater
Through Sustainable Agriculture. The Minnesota Project,
Preston, MN, 41 pp.
Massey, D.T. 1984. Land Use Regulatory Powers of
Conservation Districts in the Midwestern States for
Controlling Nonpoint Source Pollution. Drake Law
Review 33:36-11.
Moss, E. (ed.). 1977. Land Use Controls in the United
States: A Handbook on the Legal Rights of Citizens.
Natural Resources Defense Council/The Dial Press, New
York, NY.
EPA/570/9-91-009, 144 pp.
U.S. Geological Survey. 1977. National Handbook of
Recommended Methods for Water Data Acquisition.
Reston, VA.
Walton, W.C. 1984. Practical Aspects of Ground Water
Modeling. National Water Well Association, Worthington,
OH.
STEP THREE—Identifying Sources of
Contamination
The following publications may be useful for identifying
potential contaminant sources.
Cape Cod Aquifer Management Project (CCAMP). 1988.
Guide to Contaminant Sources for Wellhead Protection.
Available from EPA Region 1 (617-565-3600), or
National Technical Information Service (NTIS), 5285 Port
Royal Road, Springfield, VA.
Conservation Law Foundation of New England Inc. 1984.
Underground Petroleum Storage Tanks: Local Regulation
of a Ground-Water Hazard. Boston, MA.
D'ltri, F.M. and LG. Wolfson (eds.). 1987. Rural Groundwater
Contamination. Lewis Publishers, Chelsea, Ml.
Lukin, J. 1992. Understanding Septic Systems. Northeast
Rural Water Association, Williston, VT, 18 pp.
Miller, D.W. 1982. Groundwater Contamination: A Special
Report. Geraghty & Miller, Inc., Syosset, NY.
National Small Flows Clearinghouse. An EPA clearinghouse
for information about onsite disposal systems; monthly
newsletter and extensive publications list. 258 Stewart
Street, P.O. Box 6064, Morgantown, WV. 1-800-624-8301.
Pye, V.I., R. Patrick, and J. Quarles. 1983. Groundwater
Contamination in the United States. University of
Pennsylvania Press, Philadelphia, PA.
U.S. Environmental Protection Agency. 1986. Pesticides in
Ground Water: Background Document
EPA/440/6-86-002 (NTIS PB88-111976).
U.S. Environmental Protection Agency. 1987. EPA Activities
Related to Sources of Ground Water Contamination.
EPA/440/6-87/002 (NTIS PB88-111901), 125 pp.
U.S. Environmental Protection Agency. 1990. Ground Water
Handbook, Vol I: Ground Water and Contamination.
EPA/625/6-90/016a.
U.S. Environmental Protection Agency. 1991. A Review of
Sources of Ground-Water Contamination from Light
Industry. EPA/440/6-90-005 (NTIS PB91-145938).
107
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National Research Council. 1986. Ground Water Quality
Protection: State and Local Strategies. National
Academy Press, Washington, DC, 309 pp.
Page, W.G. (ed). 1987. Planning for Groundwater Protection.
Academic Press, Orlando, FL.
Potter, J. 1984. Local Ground-Water Protection: A Sampler of
Approaches Used by Local Governments. Misc. Paper
84-2. Wisconsin Geological and Natural History Survey,
Madison, Wl, 17 pp.
Redlich, S. 1988. Summary of Municipal Actions for
Groundwater Protection in the New England/New York
Region. New England Interstate Water Pollution Control
Commission, Boston, MA.
University of Oklahoma. 1986. Proceedings of a National
Symposium on Local Government Options for Ground
Water Pollution Control. Norman, OK.
U.S. Environmental Protection Agency. 1985. Protection of
Public Water Supplies from Ground-Water
Contamination. EPA/625/4-85/016, 181 pp.
U.S. Environmental Protection Agency. 1988. Household
Hazardous Waste: Bibliography of Useful References
and List of State Experts. EPA/530/SW-88-014, 37 pp.
U.S. Environmental Protection Agency. 1988. Protecting
Ground Water Pesticides and Agricultural Practices.
EPA/440/6-88-001. Office of Ground Water Protection.
U.S. Environmental Protection Agency. 1988. Sole Source
Aquifer Designation Petitioners Guidance.
EPA/440/6-87-003 (NTIS PB88-111992).
U.S. Environmental Protection Agency. 1990. Guide to
Ground Water Supply Contingency Planning for Local
and State Governments. EPA/440/6-90-003 (NTIS
PB91-145755).
U.S. Environmental Protection Agency. 1991. Managing
Ground Water Contamination Sources in Wellhead
Protection Areas: A Priority Setting Approach (Draft).
Office of Ground Water and Drinking Water.
U.S. Office of Technology Assessment (OTA). 1984.
Protecting the Nation's Groundwater from Contamination,
2 Vols. OTA-O-233 and OTA-O-276. For sale by the
Superintendent of Documents, U.S. Government Printing
Office, Washington, DC 20402.
Western Michigan University. 1988. Policy Planning and
Resource Protection: A Groundwater Conference for the
Midwest, Institute for Water Sciences, Kalamazoo, Ml.
Yang, J.T. and W.C. Bye. 1979. A Guidance for Protection of
Ground-Water Resources from the Effects of Accidental
Spill of Hydrocarbons and Other Hazardous Substances.
EPA/570/9-79-017 (NTIS PB82-204900), 166 pp.
Yang, J.T. and W.C. Bye. 1979. Methods for Preventing,
Detecting, and Dealings with Surface Spills of
Contaminants Which May Degrade Underground Water
Sources for Public Water Systems. EPA/570/9-79-018
(NTIS PB82-204082), 118 pp.
Yanggen, D.A. and Leslie L. Amrhein. 1989. Groundwater
Quality Regulation: Existing Governmental Authority and
Recommended Roles. Columbia Journal of
Environmental Law. Volume 14, Number 1.
108
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EPA Regions
2. FEDERAL, STATE, AND LOCAL
AGENCIES
Federal Agencies
U.S. Environmental Protection Agency
Tom Belk
Office of Ground Water and Drinking Water (WH 550G)
U.S. Environmental Protection Agency
401 M Street, SW
Washington, DC 20460
Tel (202) 260-7593
Fax (202) 260-4383
U.S. EPA Regional Offices and Ground Water
Representatives
Robert Adler
Office of Ground Water
Water Management Division
U.S. EPA, Region 1
JFK Federal Building
Boston, MA 02203-2211
Tel (617) 565-3601
Fax (617) 565-4940
Virginia Thompson
Office of Ground Water
Water Management Division
U.S. EPA, Region 3
841 Chestnut Street
Philadelphia, PA 19106
Tel (215) 597-2786
Fax (215) 597-8241
Dore LaPosta
Ground Water
Management Section
Water Management Division
U.S. EPA, Region 2
26 Federal Plaza
New York, NY 10278
Tel (212) 264-5635
Fax (212) 264-2194
Beverly Houston
Office of Ground Water
Water Management Division
U.S. EPA, Region 4
345 Courtland Street, NE
Atlanta, GA 30365
Tel (404) 347-3866
Fax (404) 347-1799
Jerri-Anne Garl
Ground Water Protection
Branch
Water Management Division
U.S. EPA, Region 5
77 West Jackson Boulevard
(WG-16J)
Chicago, IL 60604
Tel (312) 353-1441
Fax (312) 886-7804
Robert Fenemore
Office of Ground Water
Water Management Division
U.S. EPA, Region 7
726 Minnesota Avenue
Kansas City, KS66101
Tel (913) 551-7745
Fax (913) 551-7765
Doris Betuel
Office of Ground Water (W-6-3)
Water Management Division
U.S. EPA, Region 9
75 Hawthorne Street
San Francisco, CA 94103
Tel (415)744-1831
Fax (415) 744-1235
Erlece Allen
Office of Ground Water
Water Management Division
U.S. EPA, Region 6
1445 Ross Avenue
Dallas, TX 75202-2733
Tel (214) 655-6446
Fax (214) 655-6490
James Dunn
Office of Ground Water
Water Management Division
U.S. EPA, Region 8
999 18th Street
Denver, CO 80202-2405
Tel (303) 294-1135
Fax (303) 294-1424
William Mullen
Office of Ground Water
Water Management Division
U.S. EPA, Region 10
1200 6th Avenue
Seattle, WA 98101
Tel (206) 553-1216
Fax (206) 559-0165
109
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Department of the
USGS: Circular 777 A Guide to
SAFE DRINKING WATER HOTLINE:
1-800-426-4791
8:30 a.m. to 5:00 p.m. Eastern Time
Monday through Friday
Provides assistance and information to the regulated
community (public water systems) and the public on the
regulations and programs developed in response to the
Safe Drinking Water Act Amendments of 1986.
To order publications from EPA's Office of Ground
Water and Drinking Water, call (202) 260-7779.
Other Federal Agencies
Interior—U.S. Geological
Survey (USGS)
(703/648-4000)
Agency
Department of Agriculture
(202/447-7590)—Soil
Conservation Service
(SCS), Agricultural Stabili-
zation and Conservation
Service (ASCS), U.S.
Forest Service (USFS)
Information Available
SCS: Soil surveys, aerial
photography, hydrologic data
(generally limited to areas where
SCS has conducted watershed
planning). Each state has
county-level (District), multi-
county (Area), and state offices.
ASCS: County-level aerial
photography. USFS: Aerial
photography, soil surveys,
hydrologic data, other resource
data for areas within National
Forests.
Department of the Interior
(Other Agencies)
(202/208-3100)—Bureau
of Land Management
(BLM), Bureau of
Reclamation (USSR).
Department of Com-
merce—National Oceanic
and Atmospheric
Administration
(301/606-4237)
Obtaining Information from the
USGS (available from USGS
Branch of Distribution, 604 S.
Pickett St., Alexandria, VA
22304) provides a good
overview. Topographic Maps:
Often available from state
geological surveys. Otherwise,
USGS Map Sales, Box 25286,
Federal Center, Denver, CO
80225 (303/236-7477).
Hydrologic Data: District Offices
of Water Resources Division
located in each state are the
primary source of information.
Water Resource Investigation
summary reports, available for
each state, list publications by
USGS and cooperating
agencies. Remote Sensing Data:
The EROS Data Center (Sioux
Falls, SD 57198; 605/594-6151)
provides access for NASA's
Landsat satellite multispectral
imagery and aerial photography.
BLM: Aerial photographs,
hydrologic and other data on
lands administered by BLM in 11
western states. Resource
Management Plans developed
by District offices provide good
summaries of geologic,
hydrologic, and other resource
data. USBR. Geologic and
hydrologic data in areas of
western states where Bureau of
Reclamation projects have been
conducted.
Photogrammetry Division (6001
Executive Blvd., Rockville, MD
20852) maintains file of aerial
photographs of the tidal zone of
the Atlantic, Gulf, and Pacific
Coasts. National Climatic Center
(NCC) (Federal Building,
Asheville, NC 28801; 704/259-
0682) is the primary source for
information on climatic data.
Annual summaries of data from
local climatic stations and a wide
variety of other data. The 1988
Selective Guide to Climatic Data
Sources, available from NCC,
provides a more detailed
description of available
information.
110
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State Agencies
Delaware
Division of Water Resources**
State ground water protection contacts are listed below.
Alabama
Department of Environmental Management**
Ground Water Branch
1751 Federal Drive
Montgomery, AL 36130
Alaska
Department of Environmental Conservation**
P.O. Box O
Juneau, AK 99811-1800
American Samoa
EPA, Office of The Governor**
Pago Pago, American Samoa 96799
Arizona
Ground Water Hydrology Section**
Department of Environmental Quality
2005 N. Central Avenue
Phoenix, AZ 85004
Arkansas
Department of Health*
Division of Engineering
.4815 West Markham Street
Little Rock, AR 72205-3867
Department of Pollution Control &
Ecology*
P.O. Box 9583
Little Rock, AR 72219
California
State Water Resources Control Board**
P.O. Box 100
Sacramento, CA 95801
Colorado
Ground Water & Standards Section**
Department of Health
4210 East 11th Avenue
Denver, CO 80220
Connecticut
Department of Environmental Protection**
Room 177, State Office Building
165 Capital Avenue
Hartford, CT 06106
"Wellhead Protection Programs
'State Ground Water Strategies
Ground Water Management Section
Department of Natural Resources &
Environmental Control
P.O. Box 1401
Dover, DE 19903
District of Columbia
Department of Consumer &
Regulatory Affairs*
614 H Street, N.W.
Washington, DC 20001
Florida
Department of Environmental Regulation**
Bureau of Drinking Water &
Ground Water Resources
2600 Blair Stone Road
Tallahassee, FL 32399-2400
Georgia
Department of Natural Resources**
Floyd Towers East, Suit 1252
205 Butler Street, S.E.
Atlanta, GA 30334
Guam
EPA**
P.O. Box 2999
Agana, GU 96910
Hawaii
Department of Health**
Ground Water Protection Program
500 Alamoana Boulevard
5 Waterfront, Suite 250
Honolulu, HI 96813
Idaho**
Water Quality Bureau
Division of Environmental Quality
Department of Health & Welfare
450 West State Street
Boise, ID 83720
Illinois
EPA**
2200 Churchill Road
Springfield, IL 62706
111
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Indiana
Depanmeni of Environmental
Management*1"
105 South Meridian
P.O. Box 6015
Indianapolis, IN 46206
Iowa
Surface & Ground Water Protection
Bureau**
Department of Natural Resources
Wallace State Office Building
900 East Grand Street
Des Moines, IA 50319
Kansas
Department of Health and Environment**
Bureau of Water Protection
Landon State Office Building
9th Floor, 900 S.W. Jackson
Topeka, KS 66612-1290
Bureau of Water Protection*
Department of Health & Environment
Building 740
Forbes Field
Topeka, KS 66620
Kentucky
Division of Water**
Natural Resources &
Environmental Protection Cabinet
18 Reilly Road
Frankfort, KY 40601
Louisiana
Department of Environmental Quality**
P.O. Box 44066
Baton Rouge, LA 70804
Maine
Department of Human Services*
State House Station 10
Augusta, ME 04333
Department of Environmental Protection*
State House #17
Augusta, ME 04333
Marshall Islands
EPA, Office of the President*
Republic of Marshall Islands
Majuro, Marshall Islands 96960
Maryland
Department of the Environment
Room 8L
2500 Broening Highway
Baltimore, MD 21224
Massachusetts
Division of Water Supply*
Department of Environmental Quality
Engineering
1 Winter Street
Boston, MA 02108
Executive Office of Environmental Affairs*
100 Cambridge Street
Boston, MA 02202
Michigan
Department of Public Health*
P.O. Box 30035
Lansing, Ml 48909
Office of Water Resources**
Department of Natural Resources
P.O. Box 30028
Lansing, Ml 48909
Minnesota
Department of Health*
P.O. Box 59040
Minneapolis, MN 55459
Pollution Control Agency*
520 Lafayette Road N, 6th Floor
St. Paul, MN 55155
Mississippi
Ground Water Quality Branch**
Bureau of Pollution Control
P.O. Box 10385
Jackson, MS 39289-0385
Missouri
Department of Natural Resources**
P.O Box 176
Jefferson City, MO 65102
Montana
Water Quality Bureau**
Department of Health &
Environmental Sciences
Cogswell Building, Room A206
Helena, MT 59620
'Wellhead Protection Programs
tState Ground Water Strategies
112
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Nebraska
Department of Environmental Control
State House Station
P.O. Box 98922
Lincoln, NE 68509-4877
1"
Ohio
Division of Ground Water**
Ohio Environmental Protection Agency
Box 1049
Columbus, OH 43266-0149
Nevada
Division of Environmental Protection**
201 South Fall St., Room 221
Carson City, NV 89710
New Hampshire
Ground Water Protection Bureau**
Department of Environmental Services
6 Hazen Drive
Concord, NH 03301
New Jersey
Division of Water Resources**
Department of Environmental Protection
CN029
Trenton, NJ 08625-0029
New Mexico
Environmental Improvement Division**
1190 St. Francis Drive
Santa Fe, NM 87504
Oklahoma
Department of Pollution Control**
P.O. Box 53504
Oklahoma City, OK 73152
Oregon
Department of Environmental Quality**
811 SW 6th Avenue
Portland, OR 97204-1334
Pennsylvania
Office of Environmental Management**
Department of Environmental Resources
P.O Box 2063
Harrisburg, PA 17120
Division of Water Supplies*
Department of Environmental Resources
P.O Box 2357
Harrisburg, PA 17120
New York
Bureau of Water Quality Management**
Department of Environmental Conservation
50 Wolf Road
Albany, NY 12233-3500
North Carolina
Ground Water Section**
Department of Environment, Health &
Natural Resources
P.O. Box 27687
Raleigh, NC 27611
North Dakota
Division of Water Supply & Pollution
Control**
Department of Health
P.O Box 5520
Bismarck, ND 58502-5520
Northern Mariana Islands
Division of Environmental Quality*
P.O. Box 1304
Saipan, Mariana 96950
*Wellhead Protection Programs
i Ground Water Strategies
Puerto Rico
Water Quality Area**
Environmental Quality Board
Box 11488
Santurce, PR 00910
Rhode Island
Department of Environmental
Management**
9 Hayes Street
Providence, Rl 02903
South Carolina
Bureau of Water Supply &
Special Programs**
Department of Health & Environmental
Control
2600 Bull Street
Columbia, SC 29201
South Dakota
Division of Environmental Regulation**
Department of Water & Natural Resources
Joe Foss Building
Pierre, SD 57501-3181
113
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Tennessee
liueiil ul Hcdll.li ctnu Eiiv
Division of Water Supply
150 Ninth Avenue, North
Nashville, TN 37219-5404
Texas
Texas Department of Health*
1100 West 49th Street
Austin, TX 78756
Texas Water Commission**
P.O Box 13087
Austin, TX 78711-3087
Utah
Bureau of Drinking Water/Sanitation*
Division of Environmental Health
288 North 1460 West
Salt Lake City, UT 84116-0690
Bureau of Water Pollution Control*
Division of Environmental Health
288 North 1460 West
Salt Lake City, UT 84114-0700
Vermont
Division of Environmental Health**
Department of Health
60 Main Street
Burlington, VT 05401
Agency of Natural Resources*
1 South Building
103 Main Street
Waterbury, VT 05676
Virginia
Water Control Board**
P.O. Box 11143
Richmond, VA 23230-1143
Virgin Islands
Department of Planning & Natural
Resources**
179 Altona & Welgunst
St. Thomas, VI 00820
Washington
Department of Social and Health Services*
Olympia, WA 98504
Department of Ecology*
Mail Stop PV 11
Olympia, WA 98504
West Virginia
Office of Environmental Health Services*
1800 Washington Street, East, Room 554
Charleston, WV 25305
Department of Natural Resources*
1800 Washington Street, East
Charleston, WV 25305
Wisconsin
Division of Environmental Standards**
Department of Natural Resources
P.O. Box 7921
Madison, Wl 53707
Wyoming
Department of Environmental Quality**
Water Quality Division
Herschler Building, 4th Floor
122 West 25th
Cheyenne, WY 82002
Other Organizations
American Planning Association (Headquarters)
1776 Massachusetts Avenue, N.W.
Washington, DC 20036
(202) 872-0611
American Planning Association Research
Department (Technical Support)
1313 E. 60th St.
Chicago, IL 60637
(312) 955-9100
American Society of Civil Engineers (ASCE)
345 E. 47th St.
New York, NY 10017-2398
(212) 705-7496
(800) 548-ASCE
American Water Works Association
6666 West Quincy Avenue
Denver, CO 80235
(303) 794-7711
National Ground Water Association
6375 Riverside Drive
Dublin, OH 43017
(800) 551-7379
"Wellhead Protection Programs
tState Ground Water Strategies
114
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National Rural Water Association
PO Box "M28
Georgia Rural Water Association
R/"iv
2915 South 13th Street
Duncan, OK 73534
(405) 252-0629
(Also see list of Rural Water State Associations below)
National Society of Professional Engineers
1420 King St.
Alexandria, VA 22314
(703) 684-2810
Rural Water State Associations
Alabama Rural Water Association
4556 South Court Street
Montgomery, Al_ 36105
(205) 284-1489
Arizona Small Utilities Association
1955 W. Grant Road, Suite 125
Tucson, AZ 85745
(602) 620-0230
Arkansas Rural Water Association
P.O. Box 192118
Little Rock, AR 72219
(501) 568-5252
California Rural Water Association
216 W. Perkins Street, Suite 204
Ukiah, CA 95482
(707) 462-1730
Colorado Rural Water Association
2648 Santa Fe Drive, #10
Pueblo, CO 81006
(719)545-6748
Connecticut & Rhode Island Rural Water Association
11 Richmond Lane
Willimantic, CT 06226-3825
(203) 423-6737
Delaware Rural Water Association
P.O. Box 118
Harrington, DE 19952-0118
(302) 398-9633
Florida Rural Water Association
1391 Timberlane Road, Suite 104
Tallahassee, FL 32312
(904) 668-2746
Barnesville, GA 30204
(404) 358-0221
Idaho Rural Water Association
P.O. Box 303
Lewiston, ID 83501
(208)743-6142
Illinois Rural Water Association
401 South Vine
Mt. Pulaski, IL 62548
(217) 792-5011
Indiana Water Association
P.O. Box 103
Sellersburg, IN 47172
(812) 246-4148
Iowa Rural Water Association
1300 S.E. Cummins Road, Suite 103
Des Moines, IA 50315
(515) 287-1765
Kansas Rural Water Association
P.O. Box 226
Seneca, KS 66538
(913) 336-3760
Kentucky Rural Water Association
P.O. Box 1424
Bowling Green, KY 42102-1424
(502) 843-2291
Louisiana Rural Water Association
P.O. Box 180
Kinder, LA 70648
(318) 738-2896
Maine Rural Water Association
14 Maine Street, Suite 407
Brunswick, ME 04011
(207) 729-6569
Maryland Rural Water Association
P.O. Box 207
Delmar, MD 21875
Salisbury, MD 21801
(301)749-9474
Michigan Rural Water Association
P.O. Box 17
Auburn, Ml 48611
(517) 662-2655
115
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Minnesota Rural Water Association
RR 2. Box 29
Northeast Rural Water Association
512 St. George Road
Williston, VT 05495
(802) 878-3276
Ohio Association of Rural Water Systems
P.O. Box 397
Grove City, OH 43123
(614) 871-2725
Oklahoma Rural Water Association
1410 Southeast 15th
Oklahoma City, OK 73129
(405) 672-8925
Oregon Association of Water Utilities
1290 Capitol Street, NE
Salem, OR 97303
(503) 364-8269
Pennsylvania Rural Water Association
138 West Bishop Street
Bellefonte, PA 16823
(814) 353-9302
South Carolina Rural Water Association
P.O. Box 479
Clinton, SC 29325
(813)833-5566
South Dakota Association of Rural Water Systems
5009 West 125th Street, Suite 5
Sioux Falls, SD 57106
(605)336-7219
Tennessee Association of Utility Districts
P.O. Box 2529
Murfreesboro, TN 37133-2529
(615) 896-9022
Texas Rural Water Association
1616 Rio Grande Street
Austin, TX 78701
(512) 472-8591
Rural Water Association of Utah
P.O. Box 661
Spanish Fork, UT 84660
(801)798-3518
Virginia Rural Water Association
133 West 21st Street
Buena Vista, VA 24416
(703) 261-7178
Elbow Lake, MN 56531
(218) 685-5197
Mississippi Rural Water Association
P.O. Box 1995
Hattiesburg, MS 39403-1995
(601) 544-2735
Missouri Rural Water Association
P.O. Box 309
Grandview, MO 64030
(816)966-1522
Montana Rural Water Systems Association
925 7th Avenue South
Great Falls, MT 59405
(406) 454-1151
Nebraska Rural Water Association
P.O. Box 186
Wahoo, NE 68066
(402)443-5216
Nevada Rural Water Association
P.O. Box 837
Overton, NV 89040
(702) 397-8985
New Jersey Association of Rural
Water & Wastewater Utilities
703 Mill Creek Road, Suite D4
Manahawkin, NJ 08050
(609) 597-4000
New Mexico Rural Water Users Association
3218 Silver, SE
Albuquerque, NM 87106
(505) 255-2242
New York State Rural Water Association
P.O. Box 487
Claverack, NY 12513
(518) 851-7644
North Carolina Rural Water Association
P.O. Box 540
Welcome, NC 27374
(704) 731-6963
North Dakota Rural Water Systems Association
Route 1, Box 34C
Bismarck, ND 58501
(710) 258-9249
116
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Washington Rural Water Association
P.O. Box 141588
Spokane, WA 99214-1588
(509) 924-5568
West Virginia Rural Water Association
P.O. Box 225
Teays, WV 25569
(304) 757-0985
Wisconsin Rural Water Association
2715 Post Road (Whiting)
Stevens Point, Wl 54481
(715) 344-7778
Wyoming Association of Rural Water Systems
P.O. Box 1750
Glenrock, WY 82637
(307) 436-8636
3. Financing Wellhead Protection
The cost of wellhead protection varies from community
to community, depending on factors such as the complex-
ity of your aquifer's geology, the number of wells in your
town, and the amount of hydrogeologic data available.
Although the problem of financing a wellhead protection
program may appear daunting to small communities at
first, there is a variety of avenues to explore to raise the
necessary revenues. After all, the cost of cleaning up a
contamination plume or finding an alternative water sup-
ply far outweighs the cost of preventive strategies such
as wellhead protection.
The information below is a brief summary of two EPA
publications on financing for wellhead protection pro-
grams: Local Financing for Wellhead Protection and
Guidance for Applicants for State Wellhead Protection
Program Assistance Funds under the Safe Drinking
Water Act. These and other publications listed below can
be consulted for detailed financial information.
Three main sources of funds exist at the local level:
• Local taxes or fees
• Private expenditures
• Intergovernmental assistance in the form of grants
and loans
These sources of revenue can be used for major wellhead
protection initiatives such as land acquisition; capital fa-
cilities; regulatory measures; and broad-based manage-
ment efforts including information gathering, wellhead
protection area delineation, public education, and contin-
gency planning.
Taxes
The principal taxes that have been used by towns to
generate funds for wellhead protection include personal
property, ad valorem, real estate transfer, and sales taxes.
Fees
The following is a list of fees that can be used to generate
income for wellhead protection:
• Impact Fees. These are paid by developers to local
governments to finance the public facilities servicing
their developments. These fees can be used to pay for
utilities, such as sewer networks, water treatment fa-
cilities, and ground water monitoring, and for corrective
action if necessary.
• Permit and Inspection Fe^es. These fees cover the
costs of permit processing and inspection monitoring
and testing. They are used to cover the administrative
costs of regulatory management efforts in wellhead
protection. The advantage of such fees is that the po-
tential polluter, rather than the public, pays the admin-
istrative control costs.
• Fines and Penalties. This form of fee is designed to change
undesirable existing practices rather than raise funds.
• Unit Charges and Access Fees. Unit charges include
, water consumption charges on water and sewer bills.
Many wellhead protection programs are financed
largely through these types of unit charges. This form
of revenue can be used for land acquisition, utility
infrastructure, ground water monitoring, and manage-
ment techniques. Access fees include connection fees
for water and sewer lines and general facilities charges
for capital costs.
• Service Fees. These fees are charged when services
are difficult to price on a unit basis and users cannot
be charged according to their level of use. This type
of fee was first used to finance storm water drainage
improvements but more recently has been used for
wellhead protection measures.
Private Expenditures
Many towns have chosen to place the costs of wellhead
protection on the private sector. This can serve the dual
purpose of limiting the town's financial burden while en-
couraging the private sector to minimize the cost of im-
plementing wellhead protection management initiatives.
Private-sector financing of wellhead protection can take
the form of a water supply company purchasing lands to
protect them from contamination or a local developer be-
ing required to install monitoring wells in sensitive re-
charge areas if development is proposed in that locality.
Intergovernmental Assistance
• Bonds and Loans. Tax exempt bonds and bank loans
are the most common types of long-term debt available
for public infrastructure programs. As with any loan,
the borrower repays the principal plus interest charges.
• Grants. Grants may be obtained from your state or
from the federal government for assistance in wellhead
117
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protection. The Safe Drinking Water Act established
-requirements for the development and implementation
4. Computer Modeling
of state wellhead protection programs and the authority
for federal grants. EPA awards these development and
implementation grants for 1-year budget periods.
States must apply for assistance funds annually during
the application period that EPA designates. For more
information on this program, see EPA's Guidance for
Application for State Wellhead Protection Program As-
sistance Funds under the Safe Drinking Water Act.
Local communities can apply for federal assistance
under EPA's Wellhead Protection Demonstration Pro-
ject.
Table 6-1 summarizes the protection activities and
funding sources for a number of wellhead protection
programs.
Publications on Financing Wellhead Protection
Allee, D.J. 1986. Local Finance and Policy for Ground Water
Protection. The Environmental Professional, Vol. 8, No. 3.
Jakubiak, S. and R. Mudge. 1987. Financing Infrastructure:
Innovations at the Local Level. National League of Cities.
Litvak, L. and B. Daniels. 1979. Innovations in Development
Finance. Council of State Planning Agencies.
Mushkin, S. 1972. Public Prices for Public Products. The
Urban Institute.
Petersen, J.E. and W.C. Hough. 1983. Creative Capital
Financing for State and Local Governments.
Government Finance Research Center, Municipal
Finance Officers Association.
Stroman, M. 1987. The Aquifer Land Acquisition Program: An
Approach for Protecting Ground Water Resources in
Massachusetts.
U.S. Environmental Protection Agency. 1987. Guidance for
Applicants for State Wellhead Protection Program
Assistance Funds under the Safe Drinking Water Act.
EPA/440/6-87-011.
U.S. Environmental Protection Agency. 1988. Developing a
State Wellhead Protection Program, A User's Guide to
Assist State Agencies under the Safe Drinking Water
Act. EPA/440/6-88-003 (NTIS PB89-173751).
U.S. Environmental Protection Agency. 1989. Funding
Ground Water Protection: A Quick Reference to Grants
Available Under the Clean Water Act. EPA/440/6-89-004
(NTIS PB92-190255).
U.S. Environmental Protection Agency. 1989. Local Financing
for Wellhead Protection. EPA/440/6-89-001 (NTIS
PB92-188705).
Watson, R. 1982. How States Can Assist Local Governments
with Debt Financing for Infrastructure. National
Conference of State Legislatures.
Williams, P.C. 1982. Creative Financing Techniques for Water
Utilities. Journal of the American Water Works
Association.
Several computer programs have been developed by
EPA that may be useful in delineating wellhead protection
areas.
• U.S. Environmental Protection Agency. 1991. WHPA:
Modular Semi-Analytical Model for the Delineation of
Wellhead Protection Areas. Version 2.0. Office of
Ground Water Protection, Washington, DC. Available
from the International Ground Water Modeling Center,
1500 Illinois Street, Golden, CO 80401. 303-273-3103.
This model calculates time of travel contours for a wide
range of aquifer conditions. The most recent version
[2.1] allows consideration of recharge and vertical leak-
age within the wellhead area.
• McDonald, M.G. and A.W. Harbaugh. 1988. A Modular
Three-Dimensional Finite-Difference Ground Water
Flow Model. U.S. Geological Survey Techniques of
Water Resource Investigations, Book 6, Chapter A1,
575 pp. A very versatile model that can address an-
isotropic, layered, heterogeneous aquifer systems.
• Newell, C.J. J.F. Haasbeek, L.P. Hopkins, S.E. Alder-
Schaller, H.S. Rifai, P.B. Bedient, and G.A. Gorry.
1990. OASIS: Parameter Estimation System for Aqui-
fer Restoration Models—User's Manual Version 2.0.
EPA/600/8-90/039 (NTIS PB90-181314). This a soft-
ware package for estimating parameters required for
modeling transport of contaminants in ground water. It
contains data on hydrogeology of major ground water
regions in the United States and data on properties of
common contaminants in ground water. It includes a
simple analytical solute transport model and is de-
signed to be used in conjunction with EPA's
BIOPLUME model for analyzing the potential for biode-
gradation of organic contaminants.
• Schafer, J.M. GWPASS: Interactive Ground-Water
Flow Path Analysis. Illinois State Water Survey, Bulletin
69. Champaign, IL. 42 pp. A reverse path numerical
model that allows calculation of time of travel contours.
A number of more complex computer models have been
developed for analyzing the flow of ground water and
transport of contaminants. EPA's Model Assessment for
Delineating Wellhead Protection Areas (EPA/440/6-88-
002; NTIS PB88-238449), provides information on 64
models with potential value for wellhead delineation.
These models were screened from a data base main-
tained by the International Ground Water Modeling Center
on more than 600 models. Most of these models require
extensive data about an area and specialized expertise
in the selection and use of computer models.
118
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Table 6-1. Examples of Funding for Wellhead Protection and Ground Water Protection
Location/Agency
Activity
Funding Source
State of Arizona
Dept. Environmental Qual.
(602) 257-2300
Town of Easton, MA
Public Water Company
(508) 238-3641
Commonwealth of
Massachusetts
Dept. Env. Qual. Eng.
(617) 292-5526
Town of Harwich, MA
Water Department
(508) 432-0304
County of San Bernardino, CA
Health Department
(714) 387-4646
State of Vermont, Dept.
Devel. & Commun. Affairs
(802) 828-3231
State of Nebraska
Natural Resource
Commission
(402) 471-2081
State of New York, Dept. of
Environmental Conservation
(518) 457-8681
City of Tacoma, WA
Planning Commission
(206) 591-5377
City of Collier, FL
Dept. Environmental Sci. &
Pollution Control
(813) 774-8904
County of Ocean, NJ
Health Department
(201) 341-9700
County of Suffolk, NY
Dept. Health Services
(516) 348-2703
Edwards Undergrd. Water
Conserv. District, TX
(512) 222-2204
South Ctrl.. Connecticut
Regional Water Auth.
(203) 624-6671
Town of Nantucket, MA
Land Bank Commission
(508) 228-7240
South Florida Water
Management District
(407) 686-8800
Performance controls on discharges
Land-use and performance controls
Aquifer land acquisition
Land-use controls
Monitoring, new well permits
Land acquisition, planning, studies
Performance controls
Land acquisition
Land-use and performance controls
(proposed)
Land-use and performance controls
Land-use and performance controls,
new well
Land acquisition
Performance controls (proposed)
Land acquisition, management
Land acquisition
Use and well permits, recharge
Permit fees (proposed)
Unit charges, access fees
General obligation bonds
General revenues, general
obligation bonds
Impact fees, permit fees
Real estate transfer excise tax
Special assessments
General obligation bonds
Permit fees, service fees
(proposed)
General revenues
Permit fees, penalties, permits,
monitoring
Dedicated sales tax
General revenues
Unit charges
Real estate transfer excise tax
Ad valorem property tax rationing
119
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Table 6-1. Examples of Funding for Wellhead Protection and Ground Water Protection (continued)
Location/Agency
Activity
Funding Source
Bourne Water District, MA
(508) 563-2294
Town of Littleton, MA
Dept. Light & Water
(508) 486-3104
Metro. Dade County, FL
Dept. Env. Resource Mgmt.
(305) 375-3303
Santa Clara Valley
Water District, CA
(408) 265-2600
LOTT Operating Agency
and County of Thurston, WA
Department of Health
(206) 786-5439
County of Spokane, WA
Dept. Public Works
(509) 456-3600
Land acquisition
Weil installation
and monitoring
Performance controls
Studies, enforcement, monitoring, and
planning
Operating permits
Plan approval
Surface and ground water supply
Sewer interceptors
Models, monitoring, public education,
planning
Interceptor sewers
Monitoring, public education, regulatory
coordination
Property tax, dedicated tax bonds
Mandatory private, unit charges
Permit fees, unit charges
Taxes
Service fees
(utility surcharge)
Permit fees
Permit fees
Surface water charges, treated
water sales, property taxes,
ground water pumping service
fees
Septic tank use fees, access fees
(general facilities charge), sewer
use service fees
Grants, sewer use service fees,
septic tank fees
Pumping service fees, septic tank
use fees, access fees, dedicated
sales tax, real estate transfer
excise tax
Pumping service fees, septic tank
service fee planning
Note: Table excludes grants.
Source: U.S. Environmental Protection Agency. 1989. Local Financing for Wellhead Protection. Office of Water, Washington DC. EPA/440/6-89/001.
120
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Appendix A
Regional Distribution of Ground Water in the United States
Researchers have identified 15 geographical ground
water regions within the United States, Puerto Rico, and
the Virgin Islands (Figures A-1 and A-2). These regions
have similar rock and soil structures and aquifer charac-
teristics (Heath, 1984; U.S. EPA, 1990a; U.S. EPA,
1990b). The discussion below provides an overview of
hydrogeological conditions in these regions. For a more
detailed discussion of ground water regions, see Ground-
Water Regions of the United States, by R. Heath, avail-
able from the U.S. Geological Survey.
Western Mountain Ranges
Tall mountains and narrow, steep valleys characterize this
region, which includes the Rocky, Sierra Nevada, Coast,
Cascade, Bighorn, Wasatch, Unita, San Juan, and Black
Hills mountain ranges. Although precipitation in the moun-
tains is abundant, much of it runs off into surface waters
in the valleys, and aquifers in these mountain areas are
limited to fractures in crystalline rocks with small storage
capacity. The valleys contain thick deposits of alluvium
(transported sand, gravel, etc. that have been washed
away and deposited by flowing water) that serve as aqui-
fers supplying moderate to large well yields. The alluvial
aquifers often are connected hydrologically to underlying
bedrock.
Alluvial Basins
The alluvial basins include the Basin and Range area of
the Southwest and the Puget Sound/Willamette Valley
Area of the Pacific Northwest. Both areas consist of thick
1 - Western Mountain Ranges
2 - Alluvial Basins
3 • Columbia Lava Plateau
4 - Colorado Plateau and Wyoming Basin
S - High Plains
6 - Nonglaclated Central Region
7 - Glaciated Central Region
8 - Piedmont and Blue Ridge
9 - Northeast and Superior Uplands
10 - Atlantic and Gulf Coastal Plain
11 - Southeast Coastal Plain
12 - Alluvial Valleys (see Figure A-2)
13-Hawaiian Islands
14-Alaska
15 - Puerto Rico and Virgin Islands
Figure A-1. Ground water regions of the United States. Source: Heath, 1984.
121
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— PUERTO HKO AND
VIRGIN ISLANDS
Figure A-2. Alluvial valleys ground water region. Source: Heath, 1984.
alluvial deposits in basins or valleys alternating with rocky
mountain ranges. The Alluvial Basins are the driest areas
in the United States, and ground water is the major water
source. The mountainous areas store and transmit limited
amounts of water in fractured bedrock. The basins in the
Southwest, including the Great Basin, typically are closed
systems through which no surface or subsurface water
leaves the region. All water arriving from other areas is
returned to the atmosphere by evaporation or transpiration.
The movement of water through the permeable deposits in
the basins often involves complex hydrogeologic relation-
ships. Most ground water in this region is obtained from
permeable sand and gravel deposits that are interbedded
with layers of saturated silts and clays. In the Puget
Sound area, most of the water is provided by thick layers
of permeable sands and gravels interbedded with clay
layers. In the Willamette Valley, precipitation is the major
source of recharge to interbedded sands, silts, and clays.
Columbia Lava Plateau
The lava in this area of south-central Washington and
northern Idaho is found in flat-lying sheet-like flows and
is the principal waterbearing unit for the region. High
permeability occurs between the lava flow layers and in
fractured rocks. The area is characterized by interflow
zones, made up of a complex series of relatively horizon-
tal aquifers separated by denser layers of rock; these
often are connected hydrologically by intersecting frac-
tures and faults within the lava sheets. Recharge is from
precipitation and infiltration from streams.
Colorado Plateau and Wyoming Basin
Sandstone with large pore spaces and fractures serves
as the primary ground water source in this area. Some
areas of alluvium in river valleys also yield small to mod-
erate amounts of ground water. Deeper ground water
often contains dissolved minerals and can be saline. Re-
charge is from precipitation and stream infiltration. Aqui-
fers in this region usually discharge to springs and
seepage areas along canyon walls.
High Plains
This region is underlain by the Ogallala formation, a thick
deposit of semiconsolidated alluvial materials made up of
sands, gravels, silts, and clays. The Ogallala is the pri-
mary aquifer; younger alluvial deposits form the aquifer
where the Ogallala is absent. Extensive areas of sand
dunes also are present in the region. In some areas, the
Ogallala is connected hydrologically to underlying con-
solidated deposits. In other areas, the Ogallala is above
rocks that often contain highly mineralized water unus-
able for drinking water.
122
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Recharge to the Ogallala aquifer is from precipitation,
which varies across the region. In permeable areas with
sand dunes, recharge increases. A caliche (a low-perme-
ability calcium carbonate layer at or near the land surface)
is present in some areas, which limits the amount of
precipitation that infiltrates to the aquifer. Extensive agri-
cultural irrigation has led to long-term declines in water
levels in this region and a decrease in aquifer thickness
in some areas.
Nonglaciated Central Region
The Nonglaciated Central region extends from the Appa-
lachian Mountains to the Rocky Mountains, and is under-
lain in most areas by consolidated rocks including
sandstones, shales, carbonates, and conglomerates.
Chemical and mechanical weathering of the bedrock in
this area has formed a layer of regolith (a residual soil
formed from weathered bedrock) that varies in thickness
and composition. Sandstones and limestones are the ma-
jor aquifers in the area, with water found primarily in
bedrock fractures. Karst formations are fairly common.
Mineralized water often is found at deeper levels. Re-
charge is from precipitation, which varies widely in the
region. Small to moderate well yields are typical, with
karst areas sometimes providing higher yields.
Glaciated Central Region
In this area, sandstones, shales, and carbonates are cov-
ered by glacial drift consisting of poorly sorted glacial till
interbedded with sands, gravels, clays, silts, and loess.
The glacial drift varies in thickness within the region;
where it is thick, sands and gravels form major aquifers
with high well yields. Fractured bedrock in the region also
often serves as an aquifer. The glacial drift and bedrock
often are connected hydrologically in this region, with the
drift providing recharge to the bedrock aquifers. Local
ground water quality problems have occurred when poor
quality water has moved from the bedrock into the glacial
drift. Hard water is common because of widespread car-
bonate rocks. Recharge to the glacial drift is by precipi-
tation and stream infiltration, and varies depending on the
type of soil and rock materials encountered.
Piedmont and Blue Ridge
The Piedmont region lies between the coastal plain and
the Appalachian and Blue Ridge mountains. It consists of
low, rounded hills that gradually increase in height until
they become two mountain ranges. The fractured meta-
morphic bedrock in this region is overlain by regolith that
yields small to moderate amounts of water to shallow
wells and serves as a storage reservoir to recharge the
bedrock aquifer. The fractured bedrock aquifers in this
area store a limited amount of water. Well yields in the
region are extremely variable. Wells often are placed in
both the regolith and the bedrock for maximum yield.
Northeast and Superior Uplands
The Northeast includes most of New England and the
Adirondack Mountains, while the Superior Uplands in-
clude most of northern Minnesota and Wisconsin. Both
areas include bedrock that has been fractured exten-
sively, with unconsolidated glacial deposits, varying in
thickness, above the bedrock. The glacial deposits com-
prise poorly sorted glacial tills, clays, and well-sorted
sands and gravels. The sands and gravels serve as im-
portant aquifers capable of producing moderate to high
yields. Ground water also occurs in bedrock fractures, but
the bedrock generally has a low ground water storage
capacity. Recharge to the glacial deposits is primarily
through precipitation; the glacial deposits provide re-
charge to the bedrock by slow seepage. Wells often are
placed close to streams where they can reverse the hy-
draulic gradient, cause induced infiltration, and obtain
greater yields.
Atlantic and Gulf Coastal Plain
This region extends southward from Cape Cod to the Rio
Grande River in Texas. The region consists of semicon-
solidated to unconsolidated deposits of sand, silt, and
clay. All deposits dip toward the Atlantic coast or the Gulf
coast. Limestone and shell beds also occur in some areas
and serve as aquifers. Recharge to aquifers is from pre-
cipitation and stream infiltration. In some areas, clay de-
posits limit recharge, and withdrawal can result in
declining water levels.
Southeast Coastal Plain
This area includes Florida and southern parts of Alabama
and Georgia, and consists of unconsolidated sand,
gravel, silt, and shell beds. The Floridan aquifer is the
primary water source for the entire region and is one
of the most productive aquifers in the United States. It
consists of thick, semiconsolidated to consolidated lime-
stones and dolomites. The Hawthorn formation, consist-
ing of clay and silt, can be found underneath much of the
surface deposits and above the Floridan aquifer, and
often acts as a confining layer. In the northern area, the
Floridan aquifer is unconfined, and recharge occurs
through precipitation; in central and southern Florida, the
Floridan is semiconfined by the Hawthorn formation, and
surface recharge is limited. The Floridan discharges to
numerous springs and streams.
Water in the southern part of the Floridan aquifer is typi-
cally saline, and the Biscayne aquifer, made up of semi-
consolidated limestone beds, is used for drinking water.
The Biscayne aquifer is unconfined and is recharged by
precipitation and surface water infiltration. Sands and
gravels also serve as aquifers throughout the region, with
small to moderate yields.
123
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Alluvial Valleys
These areas consist of thick sand and gravel deposits
often interbedded with silts and clays. The sands and
gravels, which occur mostly within the flood plain and
adjacent terraces, are permeable and can yield moderate
to large amounts of water. Ground water and surface
water often are connected hydrologically in alluvial val-
leys; ground water withdrawal might reverse the hydraulic
gradient, causing induced infiltration to the ground water
from the stream. Recharge in these areas is from streams
and precipitation.
Hawaiian Islands
The Hawaiian Islands consist of various types of lavas.
Lavas formed above sea level contain permeable inter-
flow zones, while those formed below the sea are rela-
tively impermeable. Ground water on the islands includes
dike-impounded water, perched water, and basal ground
water. The dike-impounded and basal ground water are
partially hydrologically connected. Basal ground water is
the principal water source and occurs as a fresh-water
lens floating on denser sea water. Recharge, through
precipitation, occurs quite readily because the volcanic
soils are highly permeable.
Alaska
Much of the bedrock in Alaska is overlain with unconsoli-
dated deposits of gravel, sand, silt, clay, and glacial till.
Climate is an important factor in Alaskan hydrology. Sur-
face and subsurface water often is frozen most of the
year, forming a permafrost zone of varying depths that is
present everywhere but the southern coasts. Ground
water can be found beneath the permafrost and in some
areas beneath deep lakes and alluvial channels or in sand
and gravel deposits. Where no permafrost exists, ground
water can be found in soils and bedrock. Permafrost limits
recharge to this area's aquifers. Most recharge occurs
from stream infiltration.
Puerto Rico and the Virgin Islands
The alluvium, limestone, and volcanic rocks underlying
this region are all water bearing. Geologic processes,
however, have converted these rocks to hard, dense
rocks that now contain interconnected openings only
along fractures and faults. The limestones and overlying
alluvial deposits make up the most productive aquifer, the
most extensive of which underlies the north coastal area
of Puerto Rico. This area receives abundant precipitation,
which recharges the ground water system throughout the
area. However, this and other coastal areas underlain by
productive aquifers contain fresh ground water in direct
contact with sea water. The higher inland areas have
adequate precipitation and are less subject to seawater
encroachment, but are underlain by rocks of very low
permeability, small storage capacity, and small well yields.
124
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Appendix B
Methods for Delineating Wellhead Protection Areas for Fractured Rock Aquifers6
Fractured rock aquifers are less common than unconfined
and confined aquifers (see Chapter Two). They are im-
portant supplies of drinking water, however, and should
be protected from contamination. The following methods
are suitable for delineating wellhead protection areas in
fractured rocks.
Vulnerability Mapping
Vulnerability mapping involves examining a wide range of
geologic and hydrologic maps and aerial photographs to
identify areas surrounding wells that are especially sus-
ceptible to ground water contamination. These areas in-
clude shallow or exposed bedrock, permeable soils, open
surface fractures, and sink holes (U.S. EPA, 1991b). The
maps discussed under Step Two of the Five-Step Process
(Chapter Four) should prove useful when conducting a
vulnerability study. The disadvantage of this mapping is
that it does not directly delineate a zone of contribution
for a well. Instead, once the vulnerable area around the
well has been identified, a wellhead protection area can
be established using the arbitrary fixed radius or the
simplified variable shapes delineation method (see
Chapter Four). (These delineation methods are not particu-
larly suitable for fractured rock aquifers and are best used
as first-step approaches.) Figure B-1 illustrates wellhead
protection areas delineated from vulnerability studies.
Flow-System Mapping
Flow system mapping is a subset of hydrogeologic map-
ping (see Chapter Four). It uses ground water divides
and flow-system boundaries, which can be determined
from water table mapping, to delineate the zone of con-
tribution for a well. Ground water divides and flow-system
boundaries include physical boundaries to ground water
flow and hydrologic features such as rivers, canals, and
lakes. This approach to wellhead protection area deline-
ation requires detailed mapping of the study area's water
table (see Figure B-2). Ideally, this mapping should be a
result of field measurements. If economic and time con-
straints preclude field measurement, a water table map
6Most of this information on delineating wellhead protection areas in
fractured rocks is summarized from EPA's Delineation of Wellhead Pro-
tection Areas in Fractured Rocks (EPA 570/9-91-009). For more de-
tailed technical information on these techniques, please refer to this
publication.
can be constructed from available well construction logs
and existing hydrogeologic studies. To determine the
well's approximate zone of contribution in a localized flow
system, flow lines are drawn perpendicular to the ground
water contours. These flow lines begin at the well and
extend upgradient to the ground water divide (U.S. EPA,
1991b). This method tends to produce conservative esti-
mates for zone of contribution boundaries. The following
two methods use flow-system mapping to delineate the
zone of contribution of a pumping well.
Flow-system mapping is not very suitable for aquifers
where water levels fluctuate widely throughout the year,
because the method assumes that hydrogeologic
boundaries remain relatively stationary through time (U.S.
EPA, 1991 b). This method also is not applicable to ex-
tensive flow systems.
Flow-System Mapping with Time of Travel
Calculations
This method uses a water table map to estimate the
horizontal hydraulic gradient of a welffield, and then uses
this with other hydraulic parameters to calculate ground
water velocity by solving Equation B-1.
Equation B-1:
n
Where:
v = average linear velocity of ground water
(feet/day)
K = horizontal hydraulic conductivity
(feet/second x 86,400 [feet/day])
i = horizontal hydraulic gradient (percent)
n = porosity (percent)
Ground water velocity can be used with a particular time
of travel to limit the wellhead protection area to that por-
tion of the zone of contribution that will contribute water
to the well in a specified time period (U.S. EPA, 1991b).
Time of travel contours are delineated based on the as-
sumption that contaminants in ground water will move in
the same direction and at the same velocity as ground
water (U.S. EPA, 1991b).
125
-------
s
? r*
w
o J»
si
sg
->£
Jo S
to ^
a
•a
i
a
§
o
<
A
TJ
•s.
«Q
?
(A
I
&
I
-------
L '•***
«~ • •"••—— • —» *•.
SCALE 124 000
soo o soowoo 2000
Water-table contour
(inteivaliOft)
Vi8agewe«
-------
Time of travel contours can be delineated using the fol-
lowing equation:
Equation B-2:
d=vt
where:
d = the upgradient distance from the well to the time
of travel line (feet)
v = average linear velocity in feet/year (v from
Equation B-1 x 365)
t = desired time of travel (years)
The advantage of using time of travel criterion in flow
system mapping is that the delineated zone of contribution
is more realistically sized. A disadvantage of this method
lies in the potential for using incorrect estimates of poros-
ity or hydraulic conductivity in Equation B-1, which can
lead to inaccurate wellhead protection area delineations.
Figures B-3 and B-4 illustrate zone of contribution deline-
ations in fractured rocks (U.S. EPA, 1991b).
Flow-System Mapping using the Uniform
Flow Equation
This method is the same as that discussed under Ana-
lytical Models for delineating wellhead protection areas
for unconfined aquifers in Chapter Four. This method
uses data derived from a water-table map to solve the
Uniform Row Equation (Todd, 1980) and delineate the
zone of contribution of a well in a sloping water table (see
Figure 4-13 and Equations 4-2, 4-3, and 4-4). Figure B-5
illustrates the zone of contribution delineation for a well
in crystalline rocks using the Uniform Flow Equation.
Residence-Time Approach
This delineation approach uses water chemistry to identify
ground water travel paths and flow rates (U.S. EPA,
1991b). Two isotopes,? tritium (a radioactive isotope of
hydrogen) and oxygen-18 (an isotope of oxygen), are pre-
sent in ground water and can be used to estimate the age
of water produced by a well. This is applicable to wellhead
delineation in the following ways. Determining the age and
chemical makeup of ground water allows you to check
time of travel calculations, discover the effectiveness of
zone of contribution delineation (where ground water is
hundreds of years old, a zone of contribution might be too
large to be a practical wellhead protection area), and dif-
ferentiate zones of rapid recharge from zones of less rapid
recharge (well water with the same isotopic content as a
river adjacent to it might indicate a fracture network con-
necting the river and the well) (U.S. EPA, 1991 b).
Tritium (3H) is naturally present in the atmosphere, but
its concentration increased substantially following atmos-
pheric atomic testing in the 1950s and 1960s. Tritium
concentrations increased in ground water that was re-
charged following this time period. Tritium is a very good
indicator of how recently ground water was recharged
7lsotopes of the same element have the same atomic number but dif-
ferent atomic weights.
because of its relatively short half-life, 12.3 years (U.S.
EPA, 1991b, citing Egboka et al., 1983; Knott and Olim-
pio, 1986). Tritium data are used to verify the boundaries
of zones of contribution. Oxygen-18 (18O), another natu-
rally occurring isotope, is an indicator of climate when
ground water was recharged (U.S. EPA, 1991b). The ratio
of 18O to 16O, which is the more common isotope of
oxygen present in ground water, is dependent on how
cold the climate is during recharge. This ratio becomes
lower in colder climates and can indicate the age of
ground water. The oxygen isotope ratio is also dependent
on season and helps identify water originating from different
recharge areas (U.S. EPA, 1991b).
The residence-time approach requires the collection of a
large number of high-quality ground water samples that
are subjected to extensive chemical testing. Good geo-
chemical and isotopic interpretation skills are required,
and the method might, therefore, prove expensive. In
addition, this method does not produce a zone of contri-
bution delineation. It is very useful, however, in confirming
zone of contributions and time of travels delineated by
alternative methods.
Numerical Models
Numerical flow/transport models already have been dis-
cussed under methods for mapping wellhead protection
areas for unconfined and confined aquifers (see Chapter
Four and Appendix C). When attempting to model com-
plex aquifers, numerical models are especially useful.
Most of the widely used ground water flow models as-
sume porous-media flow (see Chapter Two under ground
water movement), which is the flow associated with
granular aquifers rather than fractured rock aquifers.
These models can be used to delineate wellhead protec-
tion areas in fractured rocks if the aquifer behaves as a
porous medium at the scale of the study (U.S. EPA,
1991b). Figure B-6 illustrates the zone of contribution
developed for Junction City, Wisconsin, using a USGS
modular three-dimensional model (McDonald and Har-
baugh, 1988).
Wellhead Protection Area Delineation
Methods for Fractured Rocks That Do Not
Behave as Porous Media
The wellhead protection area delineation methods out-
lined above are suitable for fractured rock aquifers that
behave as porous media aquifers. Fractured-rock aqui-
fers that do not behave as porous media aquifers usually
fall into two categories. The first includes aquifers with
numerous interconnected fractures, and the second
includes rocks with very sparse and poorly connected
fractures in a low-permeability matrix. The wellhead pro-
tection area delineation methods that are useful for these
aquifers include vulnerability mapping, hydrogeological
mapping, residence-time approach, and some numerical
modeling (see U.S. EPA, 1991b).
128
-------
/ p It-
SCALE 1-24 000
FEiT 500 0 500 1000 2000
Water-table contour
(intervaMOft)
« » • Ground-water divide
Village we»(JC-9)
Zone of contribution
TOT Time of travel
Rgure B-3. ZOC delineation in crystalline rocks using a field-measured water-table map. A, B, and C are points where
hydraulic gradients and ground water velocities were calculated using the hydraulic conductivity determined from the pumping
test. Source: U.S. EPA, 1991b.
129
-------
OT '
m N
58
si
•o
(Q
I
a
o
I
I
to
1
'
8
-------
SCALE 1:24 000
FEET 500 0 600 1000 2000
-640— Water-table contour
(interval 5 ft)
• • * Ground-water divide
4 Test well (MW-1)
Zone of contribution
Figure B-5. ZOC delineation in a deep ground water system in dolomite using the uniform flow equation.
Source: U.S. EPA, 1991b.
131
-------
SCALE 1:24 000
FilT SOO 0 SOOtOOt) 2000
« • • Ground-water divide
«• Village well (JC-9)
Zone of contribution
TOT Time of travel
'X
ll .
Figure B-6. ZOC predicted by numerical modeling for a well in crystalline rocks. Source: U.S. EPA, 1991b.
132
-------
Appendix C
Methods for Delineating Wellhead Protection Areas for Confined Aquifers8
As discussed in Chapter Two, a confined aquifer is over-
laid by relatively impermeable soils or rocks (see Figure
2-2). The possibility of contamination is higher for uncon-
fined aquifers than for confined aquifers but contamina-
tion can occur in confined aquifers. Therefore, wellhead
protection areas for confined aquifers must be delineated.
Confined aquifers can be categorized as semiconfined
or highly confined aquifers. A semiconfined aquifer is
subject to leakage of water and possibly contaminants
from its confining strata (see Figure C-1). In highly con-
'Ground surface
x
Water table
T
Unconfined aquifer
Aquitard
QA14884C
Figure C-1. Schematic of a semiconfined (leaky) aquifer.
Source: U.S. EPA, 1991 a.
fined aquifers this leakage is negligible. The degree of
confinement of an aquifer is an important consideration
when choosing delineation methods for confined aquifers,
because some methods take vertical leakage into consid-
eration and some do not.
8Most of the information on delineating wellhead protection areas for
confined aquifers is summarized from EPA's Wellhead Protection
Strategies for Confined-Aquifer Settings (EPA 570-9-91-008). For more
detailed technical information on these techniques, please refer to this
publication.
There are many methods for delineating wellhead protec-
tion areas for confined aquifers. The following delineation
methods take into consideration the gradient of the aqui-
fer's regional potentiometric surface. Potentiometric
surfaces in confined aquifers typically are characterized
by very low gradients (see Figure C-2). Steeper initial
Ground Surface
\
Original Potentiometric
Surface^
...••'' Drawdown Curve
, Confining Bed
Confined
Aquifer
Confining Bed
Not to Scale
Figure C-2. Ground water flow toward pumping well with
a negligible initial potentiometric-surface gradient.
gradients can occur within confined aquifers, however,
and this affects the shape of the cone of depression of a
pumping well (see Figure C-3) (U.S. EPA, 1991 a). The
following sections describe delineation methods for both
confined aquifers with very low gradient potentiometric
surfaces and confined aquifers with sloping potentiomet-
ric surfaces.
Wellhead Protection Area Delineation
Methods for Confined Aquifers with
Negligible-Sloping Potentiometric Surfaces
Cone of Depression
This approach to wellhead delineation involves marking
out the lateral (areal) extent of a well's cone of depres-
sion. The lateral extent of a cone of depression occurs
where drawdown because of pumping is less than 1 foot
133
-------
Ground surface
Original
potentiometric
surface
•#SSSSS:#^
Not to scale Impermeable
Figure C-3. Ground water flow field for cone of depres-
sion of a pumping well with a regional ground water flow
gradient. Source: U.S. EPA, 1991a.
{U.S. EPA, 1991 a). The three delineation methods de-
scribed below can be used to determine the lateral extent
of the cone of depression. These methods are recom-
mended for semiconfined aquifers. They are less depend-
able for highly confined aquifers because wellhead
protection areas delineated for highly confined aquifers
using this approach tend to be very large.
Drawdown Versus Distance Curve
is method Involves measuring drawdown in several
monitoring wells located at different distances from a
pumping well. From these data, it is possible to plot draw-
down versus the log of distance to obtain a straight line.
The lateral extent of the cone of depression can be esti-
mated by reading the corresponding distance for 0 to 1
foot drawdown from this graph. Figure C-4 illustrates a
hypothetical drawdown versus log distance graph gener-
ated by a computer modeling technique. Each line refers
to an aquifer exhibiting different leakage characteristics
P', where P'=0.001 is a highly confined aquifer and
P'=10.0 is a semiconfined aquifer.
Drawdown Versus Time
This method uses a "drawdown versus time" curve (see
Figure C-5a) for a single well to determine the lateral
extent of the cone of depression. Once the drawdown
versus time curve has been established for the well in
question, the "drawdown versus distance" curve can be
obtained (see Figure C-5b). The slope of a semilog plot
of drawdown versus distance is twice that of the time
versus drawdown curve (Driscoll, 1986).
Drawdown Versus Distance Using Analytical Models
and Simple Computer Models
Analytical models can be used to determine the lateral
extent of a cone of depression. This involves solving
30
20 1.
10-
• • °
O » 500 gpm
T - 50,000 gpd/ft
S « .00001
O .001
• 0.1
O 10.0
10
100
1,000
Radius (ft)
10,000
100,000
1,000,000
Figure C-4. Simulation of drawdown versus log distance for hypothetical aquifer for different values of leakage using
computer code PTIC. Note curves are linear. At the well maximum depth of drawdown can be determined. As drawdown
approaches zero, the maximum lateral extent of the code of depression can be estimated. Source: U.S. EPA, 1991 a, citing
Walton, 1987.
134
-------
Q = discharge
K = hyHranlin rnnrinrtivity
14
235 10 20 30 50 100 200300 500 1,000
Time since pump started (min)
Data from observation well A
(a)
20-
24
28
1 235 10 20 30 50 100 200300 500 1,000
Distance from pumped well (It)
(b)
Rgure C-5. The lateral extent of a cone of depression of
a pumping well can be determined with time versus dis-
tance data. The slope of drawdown versus log distance is
twice the slope of drawdown versus log time. Used with
permission from Driscoll, Groundwater and Wells, Edition
2,1986, Johnson Filtration Systems Inc. Source: U.S. EPA,
1991 a.
equations using hydrologic parameters obtained from
pump test data or regional data. Two methods are in
general use: the Thiem equation (Thiem, 1906) and the
Theis equation (Theis, 1935). The first of these, the Thiem
equation (see Equation C-1), can be used when a cone
of depression has stopped expanding (in other words,
has reached equilibrium).
Equation C-1:
s=
where:
s = drawdown from the original potentiometric surface
b = aquifer thickness
r = radial distance at point of drawdown observation
re = radial distance of zero drawdown of cone of
depression
For a more detailed discussion on the use of this equation
the reader is referred to Ground Water Hydraulics: U.S.
Geological Survey Professional Paper by S.W. Lehman,
1972.
When a well's cone of depression is still expanding, the
nonequilibrium Theis equation can be used (see Equation
C-2). This equation enables the user to calculate the
lateral extent of the cone of depression at different times.
Equation C-2:
$ = •
W(u) is the well function of u where
1.87r2S
u Tt
s = drawdown
Q = discharge
T = transmissivity
r = radial distance to point of drawdown observation
S = storativity
t = time
For a more detailed discussion on solving this equation,
see Groundwater and Wells, Second Edition by F.G. Dris-
coll (1986).
Cones of depression for equilibrium and nonequilibrium
conditions can be delineated using simple computer pro-
grams. These computer programs are semianalytical
codes with relatively simple boundary conditions that re-
quire the input of certain hydraulic parameters including
storativity, leakage, and hydraulic conductivity (EPA,
1991 a). Information on these computer programs may be
obtained from Groundwater Pumping Tests: Design and
Analysis by W.C. Walton (1987). More complex computer
programs exist that calculate drawdown versus distance
using numerical models rather than analytical solutions;
these programs, however, require more detailed input
data. These computer programs can be used in towns
that have multiple wells with interfering cones of depres-
sion. For a list of existing computer models see Model
Assessment for Delineating Wellhead Protection Areas
(U.S. EPA, 1988).
Time of Travel
Under this delineation approach, the time of travel for a
given distance of flow or the distance of flow for a given
period of time is calculated using known hydraulic pa-
rameters, including transmissivity, porosity, hydraulic gra-
135
-------
dient, and pump discharge (U.S. EPA, 1991a). A widely
used time period in time of travel calculations is 40 years.
Analytical Methods
Equation C-3 can be used to calculate time of travel.
This time period is chosen because waters recharged in
the last 40 years have the distinguishing characteristic of
containing tritium, whereas older waters do not. Tritium
only was released into the atmosphere in the last 40
years. If ground water does not contain tritium, it can be
inferred that it will take at least 40 years for it to be
recharged. The following discussion outlines three time
of travel approaches to wellhead delineation.
The first method discussed under this approach, Cone of
Depression/Time of Travel, is considered the most accu-
rate of the methods outlined here for confined aquifers
with negligible sloping potentiometric surfaces. This is the
most adaptable method because it provides an accurate
delineation for confined and semiconfined aquifers. Ver-
tical leakage is taken into consideration and the time of
travel calculation ensures that the lateral extent of the
wellhead protection area will be limited to a realistic size.
Cone of Depression/Time of Travel
This delineation method calculates time of travel based
on the hydraulic gradient of a well's cone of depression.
The hydraulic gradient (slope of water table or poten-
tiometric surface) decreases very quickly as you move
away from a well (see Figure C-1). Therefore, the hydrau-
lic gradient is dependent on the distance away from the
well. Time of travel contours can be established through
solving analytical equations or through computer model-
ing that takes into consideration the value of the hydraulic
gradient.
Equation C-3:
where:
TOT = time of travel threshold
A1 = distance of travel for a given time period
K = hydraulic conductivity
0 = porosity
i = h/1 is the hydraulic gradient of the cone of
depression between two points of
measurement. Ah is the difference in
hydraulic head between two points of
measurement on a flow line (A1).
This equation can be arranged in order to calculate time
of travel contours:
Equation C-4:
The time of travel is estimated for various incremental
distances away from the well using Equation C-3 and
the appropriate input variables, which can be obtained
from pumping data. These incremental TOTs then are
added to obtain the total time of travel. The log of total
time of travel is plotted against the log of distance to yield
a straight line (see Figure C-6). From this graph, dis-
tances for different TOTs can be read easily. It then is
103 -
10s -
10' -
_ 10° -
o ol travel (
o q
P .3 '
10-" -;
ID'5 -j
10-* -i
i
Q • 500 gpm
T » 50.000 gpd/tt
S . .00001
40 yr
Syr
P1 (gpd/ft2) o
a .001
• 0-1 o
• 1.0 •
o 10.0 o B
3. 5 days §
o I *
50 min o B
0 1
o 1
,•''
1 '
2.500 It
300 It
•
, H
I
6,000 It
•
10
100
Radius (It)
1,000
10.000
Figure C-6. Simulation of time of travel (in years) for hypothetical aquifer for different values of leakage using computer
code PTIC. Source: U.S. EPA, 1991a, citing Walton, 1987.
136
-------
possible to mark out time of travel contours from this
information.
culate flow paths. This method especially is useful for
ostimating tho movoment of contaminants from a pollution
Reverse Path Computer Modeling
Computer models can be used to calculate the recharge
area of a well and time of travel contours. These pro-
grams use numerical techniques to map the potentiomet-
ric surface and calculate ground water flow paths in a
reverse direction. Calculating these flow paths allows the
user to determine the recharge area of a well. These
computer models include GWPATH (Shafer, 1987), and
WHPA [2.1]. WHPA, an integrated semianalytical model
for delineation of wellhead protection areas, is available
from EPA's Office of Ground Water Protection. This pro-
gram calculates wellhead protection areas by calculating
time of travel contours for negligible or sloping regional
hydraulic gradients (see Figure C-7).
Ground water flow paths in a reverse direction are calcu-
lated using either forward or reverse particle tracking
ground water flow models. Forward tracking predicts
where ground water will flow in the future and is the
method used by most ground water flow models to cal-
site. Reverse tracking is the opposite of forward tracking
and calculates where ground water flowed in the past.
Reverse path computer modeling is used for defining
wellhead protection areas because it outlines the re-
charge area of a well and the time of travel for water or
contaminants to get to a well. Estimating wellhead pro-
tection areas using reverse path modeling requires cal-
culating the water level at the well and the surrounding
potentiometric surface and using computer programs
such as those discussed above to determine the reverse
flow paths (see Figure C-7).
The advantage of using this method lies in the realistic
delineations of wellhead protection areas that sophisti-
cated computer programs can produce. These computer
programs are highly complex, however, and require a
good deal of hydraulic and hydrologic data.
Cylinder Method
This method is the same as the Calculated Fixed Radius
method for unconfined aquifers (see Equation 4-1, Chap-
10.000
8,000 -
6,000 -
4)
2
4,000 -
2,000 -
2,000
4,000 6,000
Meters
8,000
10,000
Rgure C-7. Example of reverse-path calculation using the WHPA computer program. Source: U.S. EPA, 1991 a, citing
Blanford and Huyokorn, 1990.
137
-------
ter Four). This equation assumes that all flow is horizon-
tal. This means that vertical leakage is not taken into
consideration and the aquifer is considered highly con-
fined. This can result in unrealistically large radii for cer-
tain times of travel.
Wellhead Protection Area Delineation
Methods for Confined Aquifers with
Regional Sloping Potentiometric Surfaces
Delineation methods that incorporate a sloping regional
potentiometric surface should be considered when an
aquifer's regional potentiometric gradient lies between
0.0005 and 0.001 or greater (Todd, 1980; Bear and Ja-
cob, 1965; Southern Water Authority, 1985).
Zone of Contribution with Identification of Flow
Boundaries Method
This method is the same as that described under Ana-
lytical Models for delineating wellhead protection areas
for unconfined aquifers (Chapter Four). The uniform flow
equation (Todd, 1980) is used to define the zone of con-
tribution to a pumping well in a sloping water table (see
Figure 4-13, and Equations 4-2, 4-3, and 4-4 in Chapter
Four). The Uniform Flow Equation (Equation 4-2) does
not consider vertical leakage; therefore, the wellhead pro-
tection area using this method will be oversized if there
is significant vertical leakage.
Zone of Transport with Time of Travel Contours
Approach
The following three methods calculate a zone of transport
with time of travel contours.
Analytical Solution
Equation C-5 (modified from Bear and Jacob, 1965) al-
lows the calculation of the time of travel of water along a
line parallel to the hydraulic gradient, from a point to a
pumping well (U.S. EPA, 1991a).
Equation C-5:
-.In
where:
Tx = travel time from point x to pumping well
0 = porosity
XL = distance from pumping well over which ground
water travels in Tx (time); XL is either positive or
negative depending on whether point x is
upgradient (+) or downgradient (-) of the
pumping well
Q = discharge
K = hydraulic conductivity
b = aquifer thickness
i = hydraulic gradient
A trial and error process is used to determine travel dis-
tances for specific travel times. These travel distances
and travel times only can be calculated along a line
through the well parallel to the regional hydraulic gradient
(U.S. EPA, 1991 a). This equation probably is most helpful
for determining the impact of the regional potentiometric
gradient on the shape of the wellhead protection area,
since this equation cannot delineate the complete well-
head protection area. A computer solution is necessary
to completely delineate a wellhead protection area in an
aquifer with a sloping potentiometric surface. The ratio of
the distance of ground water travel in the downgradient
direction to that in the upgradient direction for the same
time of travel indicates how noncircular the wellhead pro-
tection area will be (U.S. EPA, 1991 a).
Equation C-5 does not allow for vertical leakage; there-
fore, if the aquifer is semiconfined, the calculated well-
head protection area might be more extensive than
required.
WHPA [2.1] Model
As discussed in the previous section, WHPA [2.1] is an
integrated semianalytical model for delineating wellhead
protection areas (see Figure C-7). This computer program
can be used to determine time of travel contours for
confined aquifers with regionally sloping potentiometric
surfaces. This method is better than the two methods
outlined above because it produces a complete deline-
ation of the wellhead protection area. Additionally, WHPA
[2.1] incorporates vertical leakage in semiconfined aqui-
fers and consequently calculates a more realistic well-
head protection area.
Reverse-Path Calculations
Reverse tracking calculations, as discussed above under
time of travel methods, might also be used to determine
time of travel contours for confined aquifers with a negli-
gible regional potentiometric gradient. This method is the
most accurate of those discussed under this section, but
it can be complicated.
138
-------
Appendix D
Conversion of Units9
Units of measurements used in ground water literature
are gradually changing from the inch-pound units of gal-
lons, feet, and pounds to the International System of units
of meters and kilograms (metric units). It is, therefore,
increasingly important that those who use this literature
become proficient in converting units of measurement
from one system to another. Most conversions involve the
fundamental principle that the numerator and denomina-
tor of a fraction can be multiplied by the same number
(in essence, multiplying the fraction by 1) without chang-
ing the value of the fraction. For example, if both the
numerator and the denominator of the fraction 1/4 are
multiplied by 2, the value of the fraction is not changed.
Thus,
1221 121,1
4*2 = 8-4°r4X2-4 4
Similarly, to convert gallons per minute to other units of
measurement, such as cubic feet per day, we first must
identify fractions that contain both the units of time (min-
utes and days) and the units of volume (gallons and cubic
feet) and that, when they are used as multipliers, do not
change the numerical value. Relative to time, a day is
1,440 minutes. Therefore, if any number is multiplied by
1,440 min/d, the result will be in different units, but its
numerical value will be unchanged. Relative to volume,
a cubic foot is 7.48 gallons. Therefore, to convert gallons
per minute to cubic feet per day, we multiply by these
"unit" fractions, cancel the units of measurement that ap-
pear in both the numerator and denominator, and gather
together the units that remain. In other words, to convert
gallons per minute to cubic feet per day, we have
gallons gallons 1,440 min cubic feet
minute ~ minute d 7.48 gal
and, canceling gallons and minutes in the numerators and
denominators, we obtain
llons 1,440ft3
~ ~
-i
which tells us that 1 gal min~1 equals 192.5 ft3 cT1.
We follow the same procedure in converting from inch-
pound units to metric units. For example, to convert
square feet per day to square meters per day, we proceed
as follows:
ftLft! m2 _ m2
d dX 10.76 ft2 10.76 d
= 0.0929 m2 d"1 =
9.29x10"2m2d"1
9Heath, R. 1982. Basic Ground-Water Hydrology. U.S. Geological Sur-
vey. Water Supply Paper 2220. Washington, DC.
139
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RELATION OF UNITS OF HYDRAULIC CONDUCTIVITY, TRANSMISSIVITY, RECHARGE RATES, AND FLOW RATES
Hydraulic conductivity (K)
Meters per day
(m tf1)
1
8.64x1 02
3.05x1 0"1
4.1x10"2
Centimeters per second
(cm s'1)
1.1 6x10*
1
3.53x1 0"4
4.73x10*
Feet per day
(ft tf1)
3.28
2.83x1 03
1
1.34X10"1
Gallons per day
per square foot
(gal d"1 ft'2)
2.45x1 01
2.12x104
7.48
1
Transmissivtty (T)
Square meters per day (m2 d"1)
Square feet per day (ft2 d'1)
Gallons per day per foot (gal d"1 ft"1)
1
0.0929
0.0124
10.76
1
0.134
80.5
7.48
1
Recharge Rates
Unit depth per year
Volume
(In millimeters)
(In inches)
Flow rates
(m3 s-1)
1
0.0167
0.0283
0.000472
0.000063
(m3 min"1)
60
1
1.70
0.0283
0.00379
(m3 d"1 km'2)
2.7
70
(ft3s"1)
35.3
0.588
1
0.0167
0.0023
(ft3 d"1 mi'2)
251
6,365
(ft3 min"1)
2,120
35.3
60
1
0.134
(gal d"1 mi'2)
1,874
47,748
(gal min"1)
15,800
264
449
7.48
1
UNITS AND CONVERSIONS (Metric to inch-pound units)
LENGTH
1 millimeter (mm) = 0.001 m = 0.03937 in.
1 centimeter (cm) = 0.01 m = 0.3937 in. = 0.0328 ft
1 meter (m) = 39.37 in = 3.28 ft = 1 .09 yd
1 kilometer (km) = 1,000 m = 0.62 mi
AREA
1 cm2 = 0.1 55 in.2
1 m2= 10.758 ft2 =1.1 96 yd2
1 km2 = 247 acres = 0.386 mi2
LENGTH
1 inch (in.) = 25.4 mm = 2.54 cm = 0.0254 m
1 foot (ft) = 12 in. = 30.48 cm = 0.3048 m
1 yard (yd) = 3 ft = 0.9144 m = 0.0009144 km
1 mile (mi) = 5,280 ft = 1,609 m = 1.609 km
AREA
1 in.2 = 6.4516 cm2
1 ft2 = 929 cm2 = 0.0929 m2
1 mi2= 2.59 km2
VOLUME
1 cm3 = 0.061 in.3
1 m3 = 1,000 I = 264 U.S. gal = 35.314 ft3
1 liter (I) = 1,000 cm3 = 0.264 U.S. gal
VOLUME
1 in.3 = 0.00058 ft3 = 16.39 cm3
1 ft3= 1,728 in.3 = 0.02832m3
1 gallon (gal) = 231 in.3 = 0.13368 ft3 =
0.00379 m3
MASS
1 microgram (u.g) = 0.000001 g
1 milligram (mg) = 0.001 g
1 gram (g) = 0.03527 oz. = 0.002205 Ib
1 kilogram (kg) = 1,000 g = 2.205 Ib
MASS
1 ounce (oz) = 0.0625 Ib = 28.35 g
1 pound (Ib) = 16 oz = 0.4536 kg
140
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Appendix E
Definitions of Hydrogeologic Terms
Alluvium. A general term for unconsolidated material de-
posited by a stream or other body of running water.
Aquifer. A water-bearing rock unit that will yield water in
a usable quantity to a well or spring.
Aquifer heterogeneity. A term describing those aquifers
in which hydraulic conductivity is variable.
Bedrock. A general term for the consolidated (solid) rock
that underlies soils or other unconsolidated surficial
materials.
Capillarity. The rise in water level because of adhesion
of water to solid particles.
Capillary fringe. The zone above the water table in which
water is held by surface tension. Water in the capil-
lary fringe is under lower-than-atmospheric pressure.
Cone of depression. The depression of hydraulic heads
around a well caused by the withdrawal of water.
Confined aquifer. An aquifer saturated with water and
bounded above and below by beds having a distinctly
lower hydraulic conductivity than the aquifer itself.
Confining bed. A layer of rock adjacent to an aquifer that
hampers the movement of water into or out of the
aquifer.
Contaminant plume. An elongated and mobile column
or band of a pollutant moving through the subsurface.
Discharge area. An area in which water is lost from the
zone of saturation.
Drawdown. The decline in ground water level at a point
caused by the withdrawal of water from an aquifer.
Freshwater. Water containing only small quantities (gen-
erally less than 1,000 mg/L) of dissolved minerals.
Gaining stream. A stream or reach of a stream that
receives water from the zone of saturation.
Glacial drift. A general term for material transported by
glaciers and deposited directly on land or in the sea.
Ground water. Water in the saturated zone that is under
a pressure equal to or greater than atmospheric pres-
sure.
Ground water divide. A ridge in the water table or po-
tentiometric surface from which ground water moves
away at right angles in both directions. The line of
highest hydraulic head in the water table or poten-
tiometric surface.
Hydraulic conductivity. The capacity of a rock to trans-
mit water; expressed as the volume of water that will
move in unit time under a unit hydraulic gradient
through a unit area measured at right angles to the
direction of flow.
Hydraulic gradient. The slope of the water table or po-
tentiometric surface; that is, the change in water level
per unit of distance along the direction of maximum
head decrease. Determined by measuring the water
level in several wells.
Hydraulic head. In ground water, the height above a
datum plane (such as sea level) of a column of water.
In a ground water system, it is composed of elevation
head and pressure head.
Hydrologic cycle. The exchange of water between the
Earth and the atmosphere through evaporation and
precipitation.
Igneous rock. A rock that solidified from molten or partly
molten material.
Karst. A landscape or region characterized by rock dis-
solution.
Losing stream. A stream or reach of a stream that con-
tributes water to the zone of saturation.
Metamorphic rock. A rock formed when preexisting
rocks undergo mineralogical, chemical, and struc-
tural changes caused by high temperature, pressure,
and other factors.
Mineralized water. Water containing dissolved minerals
in concentrations large enough to affect the use of
the water for some purposes. A concentration of
141
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1,000 mg/L of dissolved solids is used commonly as
the lower limit for mineralized water.
Permeable. Having a texture that permits water to move
through it perceptibly under the head differences or-
dinarily found in subsurface water.
pH. A number used by chemists to express the acidity of
solutions, including water. A pH value lower than 7
indicates an acidic solution, a value of 7 is neutral,
and a value higher than 7 indicates an alkaline so-
lution. Most ground waters in the United States have
pH values ranging from about 6.0 to 8.5.
Porosity. The volume of openings in a rock. When ex-
pressed as a fraction, porosity is the ratio of the
volume of openings in the rock to the total volume
of the rock.
Potentiometric surface. An imaginary surface repre-
senting the level to which water will rise in a well.
Recharge area. The area in which water reaches the
saturated zone by surface infiltration.
Saturated zone. The zone (below the unsaturated zone)
in which interconnected openings contain only water.
Sedimentary rock. A layered rock formed at or near the
Earth's surface (1) from fragments of older rocks, (2)
by precipitation from solution, or (3) from the remains
of living organisms.
Specific capacity. The rate of discharge of water from a
well per unit of drawdown of the water level.
Specific retention. The amount of water that soils or
rocks will retain against the pull of gravity to the
rock/soil volume.
Specific yield. The amount of water yielded (i.e., from a
water-bearing material) under the influence of gravity.
Storativity. The amount of water an aquifer will release
from storage.
Till. An unsorted and unstratified mixture of clay, silt,
sand, gravel, and boulders deposited directly by gla-
ciers.
Time of travel. The amount of time it takes for water to
reach a well from a certain distance.
Total head. The height (usually above sea level) of a
column of water; includes elevation head and pres-
sure head. Ground water flows in the direction of
decreasing total head.
Transmissivity. The capacity of an aquifer to transmit
water; equal to the hydraulic conductivity times the
aquifer thickness.
Transpiration. Evaporation of moisture from the pores of
the skin or from the surface of leaves and other plant
parts.
Unconfined aquifer. An aquifer that contains both an
unsaturated and a saturated zone (i.e., an aquifer
that is not full of water).
Unsaturated zone. The subsurface zone, usually starting
at the land surface, that contains both water and air.
Water table. The level in the saturated zone at which the
water is under a pressure equal to the atmospheric
pressure.
142
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