v>EPA
United States
Environmental Protection
Agency
Office of
Ground-Water Protection (WH-550G)
Washington DC 20460
January 1987
Workshop on Guidance
for the Wellhead Protection
and Sole Source Aquifer
Demonstration Programs:
Hydrogeologic Criteria
-------
United States Office of January 1987
Environmental Protection Ground-Water Protection (WH-550G)
Agency Washington DC 20460
Workshop on Guidance
for the Wellhead Protection
and Sole Source Aquifer
Demonstration Programs:
Hydrogeologic Criteria
Headquarters Repository
USEPA West Bldg
1301 Constitution Avenue N.W.
Room 3340
Washington, DC 20004
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C. 20460
January 7, 1987
OFFICE OF
WATER
Dear Participants:
Welcome, and thank you for participating in this workshop to
develop guidance for implementing the Safe Drinking Water Act
Amendments of 1986. Enactment of these amendments instituted two
new programs to protect the ground-water resource: the Wellhead
Protection Program (WHP) and the Sole Source Aquifer Demonstration
Program (SSA). The Office of Ground-Water Protection at EPA
Headquarters, together with EPA regional offices, is responsible
for implementing and administering the programs.
Among its implementation responsibilities, EPA must, by
June 1987, develop and issue to the States technical guidance
which they may use in determining the boundaries of a wellhead
protection area and guidance and rule requirements for the receipt
of Federal grant support under both the WHP and SSA programs.
This workshop is intended to obtain a wide range of opinion
which will assist EPA in developing this guidance. You and the
other participants of this workshop were selected to represent
the groups involved in, or otherwise affected by, ground-water
protection efforts. Among those represented are state and local
governments, environmental groups, business and industry, other
federal agencies, and academic experts.
The goal of this workshop is to provide a forum for these
individuals and organizations to express their opinions and
viewpoints. I can assure you that the input you provide to EPA
as a participant of this workshop is vital to the implementation
of these programs. EPA will use and build upon your ideas and
comments as it develops guidance.
Again, welcome, Best wishes for a productive and interesting
workshop.
Very truly yours,
r"i
Larry Jensen
Assistant Administrator
for Water
-------
WORKSHOP BOOK
TABLE OF CONTENTS
TOPICS PAGE
Letter to Participants ii
Agenda iii
List of Participants vii
I. Introduction to the Workshop 1-1
II. Background Information on the Wellhead Protection
Program and the Sole Source Aquifer Demonstration
Program II-l
III. Criteria for Delineation of Wellhead Protection
Areas III-l
A. Introduction III-l
B. Definition of Criteria III-2
C. Matrix of WHPA Criteria/Evaluation Factors III-6
D. Guide for Team Discussion Session 111-10
IV. Methods for Delineating WHPAs IV-1
A. Introduction IV-1
B. Description of WHPA Methods IV-4
C. Matrix of WHPA Methods/Evaluation Factors IV-8
D. Guide for Team Discussion Session IV-11
V. Guide for Cross Cutting Issues Session V-l
Appendix A: Safe Drinking Water Act Amendments of 1986
Appendix B: SSA Congressional Conference Report
Appendix C: List of State WHPA Methods References
Appendix D: Glossary of Hydrogeologic Terminology
-------
AGENDA
WORKSHOP ON HYDROGEOLOGIC CRITERIA AND GUIDELINES
DATE
Wednesday. January 21
6:30-8:00 p.m. Reception
Thursday. January 22
8:30-9:00 Welcome to Participants
9:00-9:45 Background on SDWA
Amendments and EPA
Implementation Efforts
9:45-10:30 An Overview of Methods
and Criteria Used in the
U.S. for WHPA Delineation
10:30-10:45 BREAK
10:45-11:30 Presentation on Western
European WHPA Experiences
FIRST ISSUE
11:30-11:45 Prepare Work Groups for
First Issue
11:45-1:00 LUNCH
1:00-2:30 Work Groups Separate to
Discuss First Issue (Criteria)
2:30-4:00 Work Groups Convene to Make
Individual Presentation on
First Issue (Criteria)
SECOND ISSUE
4:00-4:15 Prepare Work Groups for
Second Issue
4:15-5:30 Work Groups separate to
Discuss Second Issue (Methods)
11
-------
DATE
Friday. January 23
8:30-8:45 Welcome
SECOND ISSUE (cont'd)
8:45-10:00 Presentation by Work Groups
on Second Issue (Methods)
10:00-10:15 BREAK
THIRD ISSUE
10:15-10:45 Introduce Groups to
Third Issue
10:45-12:15 Work Groups Separate to
Discuss Third Issue (Cross-Cutting)
12:15-1:15 LUNCH
1:15-2:45 Presentation by Work Groups
on Third Issue (Cross-Cutting)
2:45-3:15 Workshop Wrap-Up; General
Discussion
IV
-------
TENATIVE LIST OF PARTICIPANTS
HYDROGEOLOGY WORKSHOP
Mr. Bevin Beaudet
(American Water Works Association)
Palm Beach County Water
P. 0. Box 16097
West Palm Beach, FL 33416
Mr. Richard Boardman
Associate Deputy Secretary
Office of Environmental Management
Pennsylvania Department of Environmental
Resources
P.O. Box 2063
Harrisburg, PA 17120
Dr. Steven Born
Department of Urban and
Regional Planning
Old Music Hall
University of Wisconsin
Madison, WI 53706
Ms. Francoise Brasier
Office of Drinking Water
WH-550A -
US EPA
401 M Street, SW
Washington, DC 20460
Mr. Gary Broetzman
Director, Water Quality Control Division
Colorado Department of Health
4210 East llth Avenue
Room 320
Denver, CO 80220
Dr. Keros Cartwright
Illinois State Geological Survey
Natural Resource Building
615 East Peabody Drive
Champaign, IL 61820
Mr. Phillip J. Cherry
Delaware Dept of Natural Resources
Division of Water Resources
Ground Water Section
Supervisor, Water Supply Branch
P.O. Box 1401, 39 'Kings Highway
Dover, DE 19903
-------
Dr. Rodney S. DeHan
Assistant Bureau Chief
Department of Environmental Regulation
2600 Blairstone Road
Tallahassee, FL 32301
Mr. Jack Donohue
Division of Water Supply
Massachusetts Department of
Environmental Quality Engineering
1 Winter Street •
Boston, MA 02108
Mr. Michael Donohue
New Hampshire Department of
Environmental Services
Water Supply and Pollution
Control Division
P.O. Box 95
Hazen Drive
Concord, NH 03301
Ms. Jerri-Anne Garl
Chief, Office of Ground Water
Water Management Division
US EPA, Region V
230 South Dearborn Street
Chicago, IL 61604
Ms. Maxine Goad
New Mexico Environmental
Improvement Division
Ground Water/Hazardous Waste Bureau
P.O. Box 968
Santa Fe, NM 87504-0968
Ms. Wendy Gordon
Natural Resources Defense Council
122 East 42nd Street
New York, NY 10021
Mr. Mario Hegewald
Special Assistant to
Assistant Administrator
Office of Water
WH-556
US EPA
401 M Street, S.W.
Washington, DC 20460
Mr. Bob Hilton
Assistant to Deputy Commissioner
Indiana Department of Environmental
Management
105 S. Meridian Street
Indianapolis, IN 46225
-------
Ms. Maurine Hinkel
National Audubon Society
645 Pennsylvania Avenue, SE
Washington, DC 20003
Mr. Steven Hirsch
Office of General Counsel
LE-132S
US EPA
401 M Street, SW
Washington, DC 20460
Mr. Russell Jones
(National Agricultural Chemical Association)
Union Carbide
Agricultural Products Company
P. 0. Box 12014
Research Triangle Park, NC 27709
Mr. Kevin Kessler
Wisconsin Department of Natural Resources
101 South Webster
Madison, WI 53702
Mr. Bill Klemt
(National Drinking Water Advisory Council)
Texas Water Commission
P.O. Box 13087
Capital Station
Austin, TX 78711
Dr. Charles Kreitler
Texas Bureau of Economic Geology
University of Texas
University Station
Austin, TX 78712
Mr. Bruce Leavitt
(American Mining Congress)
Consolidation Coal Company
1800 Washington Road
Pittsburgh, PA 15241
Dr. Jay Lehr
National Water Well Association
500 West Wilson Bridge Road
Worthington, OH 43085
Mr. Matt Lorber
Office of Pesticides and Toxic Substances
TS-769C
US EPA
401 M Street, SW
Washington, DC 20460
-------
Mr. Stewart McKenzie
(National Association of Counties)
Montgomery County Council
Office Building
100 Maryland Avenue
Rockville, MD 20850
Mr. Charles Maddox
Division of Hygiene
Texas Department of Health
1100 West 49th Street
Austin, TX 78753
Mr. John Maileek
Chief, Office of Ground Water
Water Management Division
US EPA Region II
Room 805
26 Federal Plaza
New York, NY 10278
Mr. Robert E. Malpass
(Association of State and Territorial
Solid Waste Management Officials)
Chief of the Bureau of Water Supply
and Special Programs
Department of Health and Environmental Control
2600 Bull Street
Columbia, SC 29201
Mr. George Matthess
Institute of Geology and Paleontology
University of Kiel
Olshausenstrasse 40/60
2300 Kiel, West Germany
Mr. Bob Mendoza
Director, Office of Ground Water
Water Management Division
US EPA Region I
Room 2113
JFK Federal Building
Boston, MA 02203
Mr. Tom Merski
Chief, Office of Ground Water
Water Management Division
US EPA Region III
841 Chestnut Street
Philadelphia, PA 19107
Mr. Louis Mirando
(National Association of Water Companies)
Water Technical Committee Chairman
Long Island Water Corporation
Lynbrook, NY 11563
-------
Mr. Larry Mize
Utah Bureau of Drinking Water
P.O. Box 16690
Salt Lake City, UT 84116-0690
Mr. Erik Olson
National Wildlife Federation
1325 Massachusetts Avenue, NW
Washington, DC 20005
Mr. Bill Parrish
Division of Water Supply
Maryland Department of Health and Mental Hygiene
Office of Environmental Programs
201 West Preston Street, 2nd Floor
Baltimore, MD 21201
Mr. Gene Patten
United States Geological Service
Office of Ground Water
411 National Center
12201 Sunrise Valley Drive
Reston, VA 22092
Mr. Robert Paul
West Virginia Health Department
1800 Washington Street, East
Charleston, WV 25305
Ms. Hope Pillsbury
Office of Policy, Planning and Evaluation
PM-220
US SPA
401 M Street SW
Washington, DC 20460
Mr. Joe Power
Chief, Water Supply Branch
Alabama Department of Environmental Management
1751 Federal Drive
Montgomery, AL 36130
Mf5. Janet Rosati
Environmental Protection Specialist
Office of Ground Water (W-l-1)
US EPA Region IX
215 Fremont Street
San Francisco, CA 94105
Mr, Charles Rossoll
Division of Health and Engineering
State House Station 10
Augusta, ME 04333
-------
Mr. Geary Schindel
Kentucky Division of Water
Ground Water Section
18 Reilly Road
Frankfort, KY 40601
Mr. Gene Schmidt
(American Petroleum Institute)
Amoco Corporation
P.O. Box 591
Tulsa, OK 74102
Mr. Harold Seifert
Division of Engineering
Arkansas Department of Health
4815 West Markhaoi
Little Rock, AR 72205-3867
Mayor Frank Sherrill
National League of Cities
P.O. Box 565
Social Circle, GA 32079
Mr. Rhey Soloman
Hydrogeologic Research Program Manager
Watershed and Air Division
Forest Service
Room 1210 RT-E
P.O. Box 96090
Washington, DC 20013-6093
Dr. Walt Spofford
Resources for the Future
1616 P Street, NW
Washington, DC 20036
Mr. James Tripp
Environmental Defense Fund
122 Park Avenue
New York, NY 10010
Mr. Fred van Alstyne, Chief
Geotechnical Services Section
New York Department of Environmental Conservation
50 Wolf Road
Albany, NY 12233-3500
Mr. Hubert G. van Waegeningh
National Institute of Public Health
and Environmental Hygiene
P. 0. Box 150
Leidschendati
2260 AD The Netherlands
-------
Mr. Jerry Vineyard
Public Drinking Water Program
Missouri Department of Natural Resources
P.O. Box 176
Jefferson City, MO 65102
Mr. John Voytek
Ohio Department of Natural Resources
Fountain Square
Columbus, OH 43224
Mr. Mike Weber
Nuclear Regulatory Commission
Mail Stop 623SS
Washington, DC 20555
Mr. Bill Wiley
Arizona Department of Health Services
2005 North Central
Phoenix, AZ 85004
-------
This document was compiled by:
U.S. Environmental Protection Agency
Office of Ground-Water Protection
Marian Mlay, Director
with assistance from:
DAMES & MOORE
and
Booz-Allen and Hamilton, Inc.
under contract no. 68-03-3304
-------
-------
I.
INTRODUCTION TO THE WORKSHOP-
-------
CHAPTER I
I. INTRODUCTION TO THE WORKSHOP
Ground-water protection has received increasing emphasis
over the past decade as an important environmental responsibility
for the states and the federal government. Some states and
regions have been active in ground-water protection for years.
In all areas of the country, however, the decade has brought a
heightened awareness of the vulnerability of ground-water to
threats from a myriad of sources.
In 1984, the U.S. Environmental Protection Agency (EPA) took
two significant steps to improve and coordinate programs at the
federal level that affect ground water and to assist the states
in their efforts. First, EPA established the Office of Ground-
Water Protection (OGWP) as the focus of ground^water policy
coordination and planning for the Agency. OGWP is responsible
for working with the states to develop and implement ground-water
protection strategies, for coordinating EPA ground-water policies
and guidelines, enhancing ground-water data management systems .
and capabilities, and initiating and conducting special studies
of ground-water contamination, among other tasks.
Also in 1984, after several years of development, EPA
adopted a formal "Ground-Water Protection Strategy" which set
forth goals and objectives for the Agency and described the
Agency's management approach to this field. The strategy
recognized the need to enhance protection of ground-water quality
through improved programs at the Federal and State levels, and
acknowledges the States' principal role in resource protection in
contrast to EPA's statutory authorities related to specific
sources of contamination and contaminants. It called for: (a)
an EPA policy of differential protection based on use, value and
vulnerability of the resource; (b) greater policy consistency and
coordination among ground-water related programs; (c) greater
attention to sources of contamination of national concern; and
(d) support to states in ground-water strategy development and
implementation.
Nearly every State has underway or is completing a state
ground-water protection strategy, in part with the support of EPA
grants (CWA/106). About half of the States have or are
establishing their own ground-water classification systems or
other approaches to providing protection.
Last summer, the President signed the Safe Drinking Water
Act Amendments of 1986 (SDWAA) into law. The Amendments include
two new ground-water provisions: the Wellhead Protection (WHP)
Program and the Sole Source Aquifer (SSA) Demonstration Program.
Both are- designed to support development of state and local
efforts to protect ground-water resources. Included, as
-------
1-2
Appendix I, is a copy of the statutory language creating these
new programs. In addition, that portion of the Congressional
conference report which describes the programs is included as
Appendix II.
A new Section 1427 of the Act establishes a demonstration
program to protect critical aquifer protection areas (CAPA)
within designated sole source aquifers. The goal of the
demonstration programs, which can be developed by any state or
local political subdivision that identifies a CAPA within its
jurisdiction, is to demonstrate innovative technologies and
control mechanisms that can be used to ensure the maintenance of
ground-water quality for the protection of human health,
environment, and ground water.
The second new program, Section 1428 of the Act, is designed
to protect the wellhead areas of all public water systems from
contaminants that may have adverse human health effects.
Wellhead protection areas are defined as any surface or
subsurface areas adjacent to public water supply wellheads
through which containments may move and reach the wellfield.
These two programs represent major new responsibilities for
OGWP. In its continuing efforts to assist States in developing a
comprehensive strategic approach to ground-water protection, EPA
will, to the extent possible, support state efforts to
incorporate these new ground-water programs into their
approaches.
Both programs are similar in some respects—they are
voluntary programs for which some federal support may be
available, and both are designed to help keep ground water free
from contamination and to protect human health. However,
differences exist in both the goals and expected implementation
of each program. Each program is discussed in more detail in
Chapter 2.
The Workshop
Since passage of the Amendments last June, OGWP has been
actively working with a number of experts both within and outside
of EPA to help implement the new law. In soliciting this
assistance, EPA recognizes and endorses the primary role of the
states in ground-water protection. Four technical committees
have been established to assist OGWP in this effort: a SSA
designation committee; a hydrological criteria committee; a
management protection plan committee; and a grant guidelines
committee.
As noted above, ground-water protection is primarily a state
prerogative. Accordingly, EPA intends to ensure that the
guidances developed will provide states and localities maximum
flexibility in developing the programs while ensuring that the
goals and objectives of the law are met.
-------
1-3
As part of its information gathering process, OGWP is
conducting two workshops during January 1987. The goal of the
workshops is to assist OGWP in developing guidances, which EPA
intends to publish for the WHP program by June 1987. The
guidances will be used by states and municipalities to develop
their programs and to apply for -federal grants.
The primary focus of the workshops is directed at the WHP
program, rather than the SSA program. Clearly the two are
related and much of the information gathered at the workshops
will be applicable to the development of guidelines and material
for each. Still, EPA is interested in focusing the attention of
these workshops on the wellhead protection program.
The first workshop will focus on the guidance that should be
provided to the states in their efforts to delineate wellhead
protection areas around various wellfields. As described in
Subsection.1428(e) of the statute, EPA may consider
several factors such as the radius of influence around a
wellfield, the depth of drawdown of the water table by the
wellfield at any given point, the time and rate of travel as well
as the distance from the wellfield of potential contaminants, or
other factors affecting the likelihood of contaminants reaching
the well and wellfield.
The second workshop will focus on those elements of the
state program that are enumerated in the statute to ensure the
contamination of public water supply wells is avoided. The
workshop is designed to help EPA decide, as required by the
statute, how to judge whether a state program adequately meets
the goals of the law. The workshop will deal with four areas:
the definition of an "adequate state program" as defined in the
statute; identification and assessment of potential contaminants
and their sources; the management and control of such
contaminants; and the need to coordinate the roles of state and
local agencies in the design and implementation of the program.
Overview
In developing an "adequate" state program that will be
eligible for receipt of federal funds, states will have to go
through a number of steps as shown diagramatically in Figure
1-1. Key elements of these stages will be discussed and
evaluated in the two workshops.
Both workshops will consider the overall question of what
makes an adequate program and the relative roles and
responsibilities of state and local governments in developing and
implementing a plan.
The first workshop will -also deal with the technical
questions concerning the designation of the wellhead protection
area (WHPA) around public water supply wells. The second
workshop will address more programmatic concerns including the
-------
definition of contaminants and their sources, an inventory of the
sources, an assessment of the potential threat posed by the
sources, and any necessary controls or other management
approaches that have to be imposed to ensure protection of the
WHPA.
FIGURE I - 1
Major Stages in Developing and
Implementing a State WHP Program
PROGRAM
DESIGN:
Definition
of an'Adequate"
Program
ACTIVITIES:
ROLES AND
RELATIONSHIPS:
Designation of
WHP Area
.-
Inventory
tne Sources
Define
Contaminants
Assessment of
Potential
Threat
Define
Sources
Management
and
Control
Institutional
Considerations
Workbook Outline
Chapter 2 provides background information on the two
programs and a review of current state activities in wellhead
protection. The remaining chapters address the major issues for
discussion. Each issue is summarized and several options are
presented along with some advantages and disadvantages of each.
Workshop Structure
The workshop will contain four key elements, as follows:
1 . Full-Group Discussion—Review of the Working Papers
Full-group, or plenary, discussions will take place in the
main meeting room at several points during the workshop. The
purpose of these discussions will be to identify and discuss the
principal issues presented in this workbook as well as other
issues raised by the workshop participants in preparation for
more detailed discussions that occur among individual teams.
-------
1-5
2. Team Discussions
At several points during the workshop, the participants will
break into smaller teams. Each team will be expected to
independently evaluate options and develop a preliminary position
on the topic assigned. In so doing participants will be asked to
discuss"and review a number of options that EPA could use in
developing its guidance. Moreover, participants will be
encouraged to develop new options on their own.
3. Brief Team Progress Reports
At the conclusion of each of these team working sessions,
each team will present to the full working group approximately a
five-minute report of its discussion and conclusions. The
purpose of these reports will be to provide an indication to the
full group of each team's direction and, to the extent achieved,
any recommendations to the EPA.
4. Final Discussion
After the team presentations, the participants will discuss
the issues raised and the team recommendations made. The
workshop will not attempt to reach a consensus on individual
issues. Its focus will be on obtaining a full discussion of
issues and options for EPA's subsequent use in developing the
guidance.
-------
II
-------
II.
BACKGROUND INFORMATION ON THE WELLHEAD PROTECTION
PROGRAM AND THE SOLE SOURCE AQUIFER
DEMONSTRATION PROGRAM
-------
CHAPTER II
I. BACKGROUND INFORMATION ON THE WELLHEAD PROTECTION
PROGRAM AND THE SOLE SODRCE AQUIFER DEMONSTRATION PROGRAM
On June 19, 1986, President Reagan signed into law the Safe
Drinking Water Act Amendments (SDWAA) of 1986. Included in this
legislation were two programs that call for a new role for the
federal government in ground-water protection.
While ground-water protection is traditionally the
responsibility of state and local governments, in recent years
the Congress has shown increased interest in helping to address
the problem from the national" level. Both new programs are
designed to strengthen state and local efforts to address present
ground-water problems and to help eliminate future ones.
During consideration of these, and other, amendments to the
Safe Drinking Water Act, the Administration expressed concerns
about the potential Federal intrusion into highly localized
decisions such as those involving land use policy. The final
committee conference report (See Appendix II) addressed some of
these concerns and spelled out the Congress' view on the range
and scope of the new programs. The report states, inter alia,
that:
• A state's existing authority to manage, regulate, protect
or identify ground-water resources not be limited, e.g.,
a State may identify significant recharge areas not
contiguous to a well(s) in defining WHPAs.
• The program be structured to afford States maximum
flexibility in formulating a protection strategy, e.g.,
not required to adopt a regulatory program.
• States can be expected to take a wide variety of
approaches to wellhead protection and each could develop
a different approach for the whole state and within
different protection areas.
• EPA should use its disapproval power judiciously. The
only penalty for State failure to submit a plan is not
receiving grants.
As part of its efforts to implement the new law, EPA intends
to produce four documents by June, 1987.
• A technical guidance, as required by the statute, for
states to use in determining the extent of an appropriate
wellhead protection area
• A grants guidance for states to use in developing state
wellhead protection programs and in applying for grants
under the Act
-------
II - 2
• A rule required by statute that will establish criteria
for identifying critical aquifer protection areas
(CAPA's) eligible for funding consideration under the
sole source aquifer demonstration program, and
• A guidance that states and localities can use to develop
sole source aquifer demonstration programs and to apply
for a grant under provisions of the law
STATE PROGRAMS TO ESTABLISH
WELLHEAD PROTECTION AREAS (WHPAs)
Under Section 1428 of the new Amendments, States shall
develop programs to protect the wellhead areas of all public
water systems within their jurisdiction from contaminants that
may have any adverse effects on the health of humans.
WHP Grant Guidance
In order to obtain a WHP grant, a state must submit a
program to EPA that is "adequate" to protect the WHP's from
contamination. The Act specifies that the following elements be
incorporated into state programs.
• Duties of State and local agencies and public water
supply systems in implementing the program
• Delineation of wellhead protection areas for each
public well
• Identification of all potential anthropogenic sources
within the protection area
• A program that contains, as appropriate: technical
assistance; financial assistance; implementation of
control measures; education; training; and
demonstration projects to protect the wellhead areas
from contaminants
• Contingency plans for alternative water supplies in
case of contamination
• Siting considerations for all new wells
• Procedures for public participation
This program must be submitted to the Administrator of EPA
within three years after enactment. The State is expected to
implement this program within two years after it has been
approved by the Administrator. The only impact on a State for
failing to participate in the Wellhead Protection Program,
however, is the loss of related funds.
-------
II - 3
The statute is structured to allow States maximum
flexibility in formulating their programs. The Administrator
will disapprove a program only if it is not adequate to protect
public water wells from contamination. Any disapproval must be
made within nine months of submittal and should a program be
disapproved the State must modify the program and resubmit its
plan within six months.
The Administrator shall make 50-90 percent matching grants
to the State for costs for the development and implementation of
the state program. The Congress has authorized $20 million for
each of FY 1987 and 1988 and $35 million for each FY 1989 through
1991 for these purposes.
Each State which receives funds under this section must
submit a biennial State report describing its progress in
implementing the program and any amendments to the program
resulting from new wells. The Act further specifies that all
Federal programs are subject to and will comply with the
provisions of a state program. However, the President may exempt
any potential sources of pollution from the law if he determines
that the exemption serves the paramont interest of the United
States.
WHP Technical Guidance
One of the requirements of an adequate state program is that
it contains a determination of wellhead protection areas for each
public water supply. The term "wellhead protection area" is
defined in the SDWA as "the surface and subsurface area
surrounding a water well or wellfield, supplying a public water
system, through which contaminants are reasonably likely to move
toward and reach such water well or wellfield." The precise
delineation of the area is not specified in the law, but is left
to be determined by the individual State.
EPA is required to issue technical guidance by June 1987
which States may use in determining the extent of the WHP area.
According to the statute, the guidance may consider factors such
as radius of influence around a well or wellfield, the depth of
drawdown of the water table by such well or wellfield at any
given point, the time and rate of travel of various contaminants
in various hydrologic conditions, and distance from the well or
wellfield.
The terminology used to describe wellhead protection areas
is exhibited in Figure II-1 on the following page. In general, a
wellhead protection area represents a portion of an aquifer which
includes all or part of the area of influence around a pumping
well and sometimes portions of upgradient recharge areas or
portions of the surrounding aquifer as well. The "area of
influence" is the area surrounding a pumping or recharging•well
-------
II - 4
within which the potentiometric surface has been changed. .The
"recharge area" is that permeable layer through which
precipitation and surface water may percolate to the aquifer and
eventually reach the well. It is important to remember that the
Amendments allow considerable flexibility to the States in
defining which portion of this theoretical model would apply in
specific cases.
Some governments have defined wellhead protection areas to
be only hundreds or a few thousand feet from the well. Other
governments have defined them to be a mile or several miles from
the well. Wellhead protection areas are fairly common in Western
European countries such as Germany, Switzerland, and the
Netherlands and are being used in parts of the United States such
as Dade County, Florida and Cape Cod, Massachusetts.
FIGURE II - 1
DRAWDOWN CONTOURS
I 1 Are* of Influence
Area of Contribution
[ j Additional Recharge Area J to We"he*
| J Remaining Portion of Aquifer
Generalized Ground-water Flow Directions
TERMINOLOGY FOR WELLHEAD
PROTECTION AREA DELINEATION
-------
II - 5
SOLE SOURCE AQUIFER (SSA) DEMONSTRATION PROGRAM
This new Section, 1427 of the Act, builds upon the existing
Sole Source Aquifer program, Sec. 1427(e) of the SDWA. It is a
demonstration program establishing critical aquifer protection
areas (CAPA) within designated sole source aquifers to ensure the
maintenance of ground-water quality for the protection of human
health, environment and ground-water. The purpose of any
demonstration is to assess the impact of programs on ground-water
quality and to identify protection measures that are found to be
effective in protecting ground-water resources. EPA must develop
by June 1987 a rule including hydrogeological, social, and
economic criteria that will be used to identify critical aquifer
protection areas. Finally, using information obtained by the
states on their programs, EPA must provide to Congress by
September 30, 1990, a report assessing the accomplishments of the
demonstration program.
Any State or local government, municipality or other
political subdivision which identifies a CAPA over which it has
jurisdiction may apply to the EPA Administrator to have that area
selected for the demonstration program. The Governor must be a
co-applicant. An area can be defined as a CAPA if it is a
designated sole source aquifer or is part of a sole source
aquifer for which an application and designation has been
received and approved within twenty-four months of enactment and
meets CAPA criteria. Designated SSAs with an approved area-wide
ground-water quality plan under section 208 of the Clean Water
Act as of the date of enactment are defined as CAPAs under the
statute.
An applicant for a demonstration program approval must
prepare or complete several activities including the development
of a comprehensive management plan for the proposed critical
aquifer protection area (CAPA). This plan must contain the
following:
• A map detailing the boundary of the critical aquifer
protection area
• Existing and potential point and non-point sources of
ground-water contamination
• An assessment of the relationship between activities on
the land surface and ground-water quality
• Proposed actions and management practices to prevent
adverse ground-water quality impacts
• Identification of the authority adequate to implement the
plan, estimates of costs, and sources of matching funds
-------
II - 6
An applicant can include optional components in the
management plan including an assessment of the quality of
existing ground-water recharged through the area and a
comprehensive statement of land use management. If an applicant
has an approved ground-water quality management plan at the time
of enactment under Section 208 of the CWA this can be submitted
in place of the comprehensive management plans. During the
development of the plan the applicant is required to hold public
hearings and consult with all affected governmental entities.
The Administrator must approve any application received
within 120 days based on a determination that the application
meets the definition of a critical aquifer protection area and
meets the objectives of the sections. Should the application be
rejected it may be modified and resubmitted.
If the demonstration program application is approved the
Administrator may enter into a cooperative agreement with the
applicant to establish a demonstration program. The applicant
may receive 50 percent matching grants for both the development
and implementation of the program. However, the total amount of
the grant cannot exceed $4 million per year per aquifer. The
program has been authorized $10 million for FY 1987, $15 million
for FY 1988, and $17.5 million for each of the three fiscal years
1989 through 1991.
The State must prepare a report assessing the impact the
program on ground-water quality and identify those measures found
to be effective in protecting ground water. A report is due from
the State to EPA by December 31, 1989. EPA must submit a com-
bined report to the Congress by September 30, 1990.
-------
II - 7
CURRENT STATE ACTIVITIES IN WELLHEAD PROTECTION
Within the past five years most states have initiated ground
water protection programs. The structure and scope of these
programs is variable and reflects differing demographic, political and
hydrogeological conditions.-
A handful of states and municipalities have developed
wellhead protection programs as part of an overall ground-water
protection program. The main focus of these programs is the
delineation of wellhead or recharge protection areas within which land
use controls are often imposed to protect water supply wells.
Numerous methods have been developed to delineate these
protection areas. Six of the most common techniques used in the
U.S. and in Western Europe in these delineations are listed in
Figure II-2.
FIGURE I1-2 WHPA DELINEATION METHODOLOGY
CRITERIA, AND USE RELATIONSHIPS
METHOD
1. Arbitrary Fixed Radius -
A circle of standardized
dimensions having little to
no hydrogeologic basis.
2. Calculated Fixed Radius -
A circle of standardized
dimensions determined
mathematically with
hydrogeologic basis.
3. Simplified Variable Shapes -
Standardized recharge areas
derived from analytical
calculations.
4. Analytical Flow Model -
A mathematical determination
of the area in which ground-
water contributes to a
pumping well.
5. Geologic/Geomorphic - An area
defined by flow boundaries
detected through geologic
field study and observation.
Numerical Flow/Transport Model
A computerized approximation
to the solution of
differential equations (e.g.,
ground-water flow and/or
solute transport).
CRITERIA
RELIED ON
Distance
Distance
Time of Travel
Time of Travel
Drawdown
Drawdown
Physical Features
Physical Features
Time of Travel
Drawdown
SELECTED
LOCATIONS
WHERE USED*
Nebraska
Florida
Edgartown, MA
Duxbury, MA
Florida
England
Cape Cod, MA
Duxbury, MA
Edgartown, MA
West Germany
Holland
Vermont
Midstate Reg.
Planning Agen.,
CT
Duxbury, MA
Dade Co., FL
Broward Co.,FL
Palm Beach, FL
or being considered
-------
II - 8
The methods range in sophistication from those which can be
applied simply by non-technicians (e.g., Fixed Arbitrary Radius)
to very complex methods which require a highly trained, technical
specialist (e.g., Numerical Flow/Transport Model). Each has
inherent strengths and limitations which must be considered in
method selection and program implementation. The less
sophisticated forms can be easily applied and are relatively
simple to administer. They are, however, less likely to
reproduce actual conditions. They may therefore provide
"inadequate" or "excessive" protection in different settings.
More sophisticated methods more closely reproduce actual
conditions, however, they are more expensive to implement and
more complex to administer. Thus, certain tradeoffs or method
combinations may be required when designing WHPA programs in
order to adequately define the area to be protected.
A brief review of wellhead protection activities in selected
states follows. While not exhaustive, this survey will give
workshop participants an indication of what is already being done
at the state and local level in wellhead protection.
State of Florida
Florida's state and county governments have some of the most
sophisticated ground-water protection program in the nation. The
state has also proposed amendments to Chapter 17-3 of the Florida
Administrative Code that would establish a wellhead protection
program for highly vulnerable aquifers. The program would
require protection zones around wellheads in which land use
controls would be used to restrict activities that could
potentially contaminate the ground-water supply.
The proposed law establishes two protection zones around
major public community drinking water supplies (with an average
daily withdrawal of at least 100,000 gallons of ground-water).
The zones are defined as two concentric areas around the major
public water supply well(s) or wellfield(s) of 200 feet and five
years ground-water travel time respectively.
Discharges into the ground-water from storm water
facilities, underground storage facilities, underground
transportation pipes and other sources are subject to varying
degrees of control depending on their proximity to the wellhead.
The proposed law, for example, prohibits new discharges and
new installations within the 200 foot zone of protection. Within
the five year zone of protection, new discharges from several
types of facilities are subject to varying levels of control and
monitoring requirements. New discharge of industrial waste that
contains hazardous constituents is prohibited and new discharge
of treated domestic waste effluent is allowed provided a number
of conditions are met.
-------
II - 9
Dade Countyf Florida
Dade County has developed a comprehensive wellhead
protection program. The County's program consists of five
elements: water management, water and wastewater treatment, land
use policy, environmental regulation and enforcement, and public
awareness and involvement. The program consists of an array of
prohibitions, restrictions, permit requirements, land use tools
and management controls designed to protect all of Dade County's
public water supply wells from contamination by the approximately
900 substances the county has identified as hazardous. Features
of the county's program include:
• Delineation of recharge areas around wellfields, using
computer modeling
• An array of restrictions applied within designated
wellfield protection zones. Examples include
No new activities involving hazardous materials
Annual permitting and inspection of all
non-residential uses
Density restrictions within protection zones
Expedited sewering of unsewered protection areas
Expedited clean-up of known areas of contamination
• Information programs to educate the public concerning
the importance and methods of protecting drinking
water
• Treatment programs to adequately purify drinking water
(including air stripping of volatile organics) and for
safe disposal of wastewater and other wastes.
Clean-ups of known sources of contamination are
included
• A water management program, including canal
construction, to protect wellfield recharge areas from
existing contamination, and a monitoring program to
verify the results
• A regulatory program including extensive permitting
and inspection of all non-residential activities in
wellfield areas plus extensive design criteria for
development
• A land use control program prohibiting or limiting
certain land uses in proximity to wellfields as a
function of hydraulic travel time.
-------
11-10
Furthermore," Dade County maintains a computerized inventory of
contaminant sources and issues approximately 10,000 operating
permits per year to recognized, non-residential, users within the
delineated wellfield protection zones.
Massachusetts
Massachusetts implements its wellhead protection program
through the Aquifer Land Aquisition Program (ALA). The goals of
the program are to help local officials define the primary water
recharge areas around public water supply wells, to work with
local officials to properly address land uses within the recharge
areas of these wells, and to reimburse eligible applicants for
land aquired in the recharge area for water supply protection
purposes. The program encourages a mix of strategic land
aquisition and effective land use controls to achieve water well
protection.
As part of the program the Massachusetts Department of
Environmental Quality Engineering (DEQE) has defined 3 zones of
contribution that compose the total recharge areas to a public
well. Theoretically these 3 zones constitute the geographic area
in which land uses may impact the drinking water supply well.
• Zone 1, the 400' radius or other designated area
surrounding a water supply well, must be in compliance
with DEQE Drinking Water Regulation (310 CMR 22.00)
• Zone II is that area of an aquifer which contributes
water to a well under the most severe recharge and
pumping conditions that can be realistically
anticipated. It is bounded by the ground-water
divides which result from pumping the well and by the
edge of the aquifer with less permeable materials such
as till and bedrock. At some locations, streams and
lakes may form recharge boundaries.
• Zone III is that land area beyond the area of Zone II
from which surface water and ground water drain into
Zone II. The surface drainage area as determined by
topography is commonly coincident with the
ground-water drainage area and will be used to
delineate Zone III. In some locations, where surface
and ground-water drainage are not coincident, Zone III
shall consist of both the surface drainage and the
ground-water drainage areas.
The delineation and management of these 3 zones forms the
basis of a competitive ALA grant program through which local
governments compete to obtain funds from the state to purchase
land for water well protection purposes.
-------
II - 11
The Commonwealth has restricted the reimbursement for land
purchases to Zone II. The rationale for this decision was that
Zone II areas consist of relatively permeable surficial deposits
and represent the area of the municipality in which land uses
have the greatest potential for adversely impacting the local
water well(s). Zone I was eliminated from the reimbursement
scheme because under Massachusetts law the water supplier is
already required to control land use within the 400 foot radius
surrounding the well.
The program requires applicants to supply four major
categories of information: aquifer/water supply information,
land use information, resource protection plans, and land
aquisition information. Under the first category, Zones I, II
and III must be delineated and mapped. Any pump tests or
modelling used to delineate zones must be documented.
Some level of land use information must be supplied for all
three zones. All major land use activities such as commercial,
residential, agricultural, and industrial uses in Zone II must be
mapped and public transportation and corridors identified. For
areas in Zone III, only those land use activities that pose
significant threats to ground water such as hazardous waste
sites, surface impoundments, landfills, auto junkyards,
underground storage tanks, salt storage sheds, and sand and
gravel operations that occur in the zone, need be documented.
A water resource protection strategy that identifies
existing and/or proposed land use controls designed to protect
the supplies must be included in the package on the suggested
land and/or easement purchase. The state uses this information
to determine whether there is a sound basis for the locality
aquiring the land and whether the town will indeed be able to
complete the land aquisition should an award be granted.
All applications are ranked and prioritized based on two
major criteria: the value and use of the resource and the degree
of resource protection that can be expected from the proposed
water protection strategy.
Vermont
The state is in the process of developing a state wide
wellhead protection program. As part of this program, the Agency
for Environmental Conservation is developing regulations that
will be used to map the cone of influence, the primary recharge
areas and the secondary recharge areas of water wells in Vermont.
These maps will be used by AEC and other regulatory agencies in
their permitting activities.
-------
11-12
One tool currently available to state regulatory agencies in
making management decisions are the existing maps of recharge
areas or Aquifer Protection Areas that were delineated in the
Vermont Aquifer Protection Area (APA) Project in the 1970's. The
APA project resulted in 209 individual APA's located in 104 of
Vermont's towns. These APAs are defined as the land surface area
that encompasses the recharge, collection, transmission, and
storage zones for a town's well or spring.
Eight categories of APAs were delineated based on
hydrogeological factors:
• Wells in unconfined and leaky unconsolidated aquifers
with available engineering pump tests.
• Wells in unconfined and leaky unconsolidated aquifers
without engineering pump tests.
• Wells in confined unconsolidated aquifers.
• Bedrock wells, using an infiltration model
• Bedrock wells, using a leakage model
• Springs in unconsolidated material and at the
interface between unconsolidated material and bedrock,
with high relief in the upgradient direction
• Springs in unconsolidated material and at the
interface between unconsolidated material and bedrock,
with low relief in the ungradient direction
• Springs emanating from bedrock
There are no regulations associated with mapped APAs but existing
state regulatory programs use APAs to flag areas needing special
consideration during the review process on development
applications.
European/Experience
At least eleven European countries have developed some form
of wellhead protection concept, with West Germany and the
Netherland having the most extensive experience in this area.
In both countries, the first protective zone lies
immediately around the wellhead, with a secondary zone
representing the distance that ground-water will travel in 50
(West Germany) or 60 .(Netherlands) days. This second zone is
designed to protect the well from microorganisms.
-------
II - 13
Each country then has a "water protection" area, comparable
to the WHPA boundaries seen in the United States. In West
Germany this zone extends to 2 kilometers from the well (until
aquifer boundaries are reached) while in the Netherlands, the
"protection zone" extends to 10 and 25 year travel times. These
correspond approximately to distances of 800 meters and 1200
meters from the wells. Finally, an outermost zone is drawn,
in each country, to the recharge area boundary. Within these
zones, restrictions are imposed on a number of activities
including, but no limited to, waste disposal sites, the transport
and storage of hazardous chemicals, wastewater disposal, and the
application or leachable pesticides. The degree of restriction
decreases as the distance from the wellhead increases.
-------
iii
-------
CHAPTER III
CRITERIA FOR DELINEATION OF
WELLHEAD PROTECTION AREAS
-------
CHAPTER III
CRITERIA REQUIRED IN DELINEATING WHPA's
A. Introduction
Many conditions exist which control the manner, rate and
volume of ground-water movement in the earth. These conditions
greatly influence the amount of water that can be pumped from a
well, the impact a pumping well may have on local water
resources, the characteristics of recharge to a wellhead, or the
extent to which a contaminant might be carried by a ground-water
flow system. It is necessary to identify the interrelated
criteria on which these conditions are based. This must be done
before we can develop methodology to determine "adequate"
protective distances around producing wells. Thus, in developing
a WHPA programs, an initial step is to evaluate the various
criteria that will ultimately be used to provide the basis for
boundary determinations. It will be necessary to consider which
types of criteria might be specified, should minimum thresholds
be set for the criteria and then, what methods should be used to
translate the criteria to "on-the-ground" WHPA boundaries.
The Agency's guidance on delineation approaches must, by
statute, recognize a wide range of hydrogeologic settings. A
comprehensive wellhead protection program would include the
delineation of some geographical area across which monitoring,
source identification, and control strategies would be applied.
While the States need not use the guidance in designing or
implementing their programs, the Agency must still decide if the
States' approach meets the overall "standard" in the Amendments.
This chapter is divided into three remaining sections. The
first two provide background information on WHPA criteria,
III-l
-------
whereas, the final section will be used to focus team
discussions.
B. Definition of Criteria
For simplicity, "criteria" in this workshop identify those
hydroaeoloqic factors which must be considered in establishing a
boundary line of protection around a well or wellfield. These
criteria are usually related to an overall program goal, examples
of which are depicted in Figure III-3.
The most common criteria available or presently used in the
United States and in Western Europe to delineate WHPAs involve
combinations of: 1) Distance; 2) Drawdown; 3) Time-of-Travel
(TOT); 4) Physical Boundaries; and 5) Assimilative Capacity. The
following paragraphs discuss these hydrogeologic factors.
1. Distance - Measured length away from a pumping well to the
point of concern.
Discussion - The point of concern may be based on either
administrative (e.g. fixed radius) or hydrogeologic criteria. For
the first example, an administrator may determine that some set
distance is preferable over no such set distance, and therefore,
select an arbitrary set distance for the WHPA criterion. From a
hydrogeologic perspective, the point of concern might be
calculated based on state-wide average conditions, or where
drawdown effects are considered negligible under average pumping
scenarios. One number might be chosen to represent such
conditions, and that number be universally applied.
Example - Nebraska has designated a WHPA as a ring having a
1,000 foot radius around a well. Florida has a Zone I area of
protection which has a 200 foot radius. West Germany has 2 km
(6,560 feet) for Zone III-A.
III-2
-------
2. Drawdown - Relative change in the position of the static
water level in an aquifer because of ground-water withdrawal.
Discussion - The pumping of a well induces drawdown in the
surrounding aquifer. Basing the criteria on drawdown implies
that all or a part of the "area of influence" of the well will be
included in the WHPA. Areas of zero drawdown are outside the
area of influence per se, but may be upgradient and thus still
"recharge" the well. Drawdown is directly proportional to the
rate of withdrawal and the length of time that the withdrawal has
been occurring. It is inversely proportional to the aquifer's
hydraulic conductivity, saturated thickness, storativity, and
distance between the well and the point at which the drawdown is
being observed. Given the asymptotic slope of the drawdown
curve, minor changes in the threshold could lead to major changes
in the area encompassed by the WHPA.
Example - Massachusetts uses the 0.1 foot drawdown contour
while Dade County, FL uses the 0.25 foot drawdown contour and
Palm Beach and Broward Counties, FL use 1.0 foot drawdown
contour.
3. Time-of-Travel - Time it takes for a molecule of water, or a
contaminant flowing at an equivalent rate (i.e., advective flow),
to reach a well.
Discussion - Time-of-travel could be independent of drawdown
and distance. Commonly however, the Time-of-Travel is directly
proportional to the length of the flow path and the effective
porosity of the aquifer. The Time-of-Travel is inversely
proportional to the aquifer's hydraulic conductivity and the
hydraulic gradient.
III-3
-------
t = nx Where: t = Time-of-Travel
ki n = porosity
x = distance
k = Hydraulic -Conductivity
i = Hydraulic Gradient
Example - West Germany uses a 50-day travel-time. Palm
Beach uses a 30-day travel time for Zone I, a 210-day travel time
for Zone II and the greater of a 500-day travel time or a one
foot drawdown contour for its Zone III. Broward and Bade
Counties use travel times of 10 days, 30 days and 210 days (or
1.0 foot drawdown if larger) to designate their zones. The State
of Florida uses five years for their Zone II and the Netherlands
use 10-25 years for their Zone Ilia. A conceptual sketch of TOT
is shown in Figure III-l.
4. Physical Boundaries - The physical boundaries of the local
or subregional ground-water flow system act as no-flow barriers
(or assumed no-flow barriers in the case of surface-water
divides).
Discussion - Barriers exist which make it nearly impossible
for ground water to move from a location towards a pumping well.
Examples of conditions which might provide isolation include
regional ground-water divides that separate adjoining basins,
perennially gaining canals and rivers, or confining units which
may separate deeper units from shallower ones. The degree of
isolation that exists may be critical in determining the extent
to which a potential pollution source could contaminate a well.
Example - Edgartown and Duxbury, Mass, use or are
considering methods that include the delineation of upgradient
and downgradient divides. The State of Vermont in its prototype
also defined a secondary area of protection based on the
upgradient recharge area by using, the surface water divide as a
close approximation for the ground-water divide.
III-4
-------
IDEALIZED SKETCH OF WHPA CRITERIA:
EXAMPLE FROM SE FLORIDA
INDIVIDUAL DOMESTIC
WATER SUPPLY WELL
SEPTIC TANK \
PUBLIC UTILITY
WATER SUPPLY WELL
CONE OF DEPRESSION
DISTANCE FROM WELL
TOT-TIME OF TRAVEL
EXHIBIT NOT TO SCALE
SOURCE: Dade Co., FL, Dept. of Environmental Resources Management (1983)
FIGURE III 1
-------
Assimilative Capacity - An area (of protection) where
natural attenuation processes are capable of reducing
contaminant's concentration to a target level.
Discussion - Attenuation processes such as filtration,
biodegradation, dilution, sorption, and volatilization decrease
the concentration of contaminants as they pass through the soil,
bedrock and ground water. The ability of natural systems to
restore ground waters to their original or "acceptable" state
varies widely. The nature and volume of the contaminant, the
quality of the attenuating materials and the amount of dilution,
diffusion and dispersion which can occur are examples of factors
which influence assimilation.
Example - No known examples can be cited where assimilation
capacity or retardation factors are included in the delineation
of WHPA boundaries. However, some ground-water protection
efforts have been targeted to reduce nitrate loadings (e.g., Long
Island) which might be conceptually utilized. The Amendments
imply that such an approach might be valid for WHPA delineation.
'C. Matrix of WHPA Criteria/Evaluation Factors
A matrix has been prepared (Figure III-2) to rank the
criteria against a number of evaluation factors that could
influence the selection and/or application of WHPA criteria.
Workshop participants will be asked to comment on this matrix in
terms of its overall structure, as well as the tentative
assessments within the matrix itself.
The evaluation factors used in the matrix are defined as
follows:
III-6
-------
WHPA CRITERIA/EVALUATION FACTORS
\. EVALUATION
^XF ACTORS
CRITERIA^^
DISTANCE
DRAWDOWN
TIME OF
TRAVEL
PHYSICAL
BOUNDARIES
ASSIMILATIVE
CAPACITY
ABILITY TO
UNDERSTAND
CRITERIA
L/M/H
T N
H
H
L-M
M-H
L-M
H
n-H
L-M
L-M
L
USER
SOPHISTI-
CATION
L/M/H
L
M
M-H
M-H
M
EASE OF
QUANTIFI-
CATION
L/M/H
H
M-H
M-H
L
L
VARIABILITY
UNDER
ACTUAL
CONDITIONS
L/M/H
L
M-H
M-H
L
L
FIELD
VERIFICATION
L/M/H
H
M
L-M
L-H
L
ABILITY TO
REFLECT
AMBIENT
GW STD.
L/M/H
L
L-M
H
L-H
H
SUITABILITY FOR
DELINEATION
METHODS
L/M/H
1 2 3 4J5J6 7
H
L-
n
L
L
L
L
M
L
L
L
L
M
H
M
L
L
L
M-
H
M-
H
L
L
M
M
H
L
H
L
L
H
H
L
L
L
i~
M
H
M
H
CRITERIA
DEVELOPMENT
COST
L/M/H
L
M-H
M-H
M-H
H
SUITABILITY
FOR
GEOLOGIC
SETTINGS
L.M.H
H
M-H
M-H
M-H
L-M
1- ARBITRARY FIXED RADIUS L-LOW
2 - CALCULATED FIXED RADIUS M-MEDIUM
3 - SIMPLIFIED VARIABLE SHAPES H-HIGH
4 -ANALYTICAL MODELS T-TECHNICAL
6 - OEOLOGIC/GEOMORPHIC MAPPING N-NON TECHNICAL
6 -NUMERICAL MODELS
7 - MISCELLANEOUS METHODS-TRACING
FIGURE 111-2
-------
1. Ability to Understand Criteria - Degree to which the
principles underlying a criterion can be readily comprehended and
used by hydrogeologists/non-technical people.
Comment - How easily a criterion can be understood relates
to its application. Only ground-water specialists may be able to
apply complex, highly technical approaches to criterion
development while others, such as distance, may easily be
utilized by policy or program specialists.
2. User Sophistication - Technical abilities of user necessary
to understand the basis of criteria, the application of their
input data requirements and how their results can be evaluated.
Comment - Compatibility between user knowledge and criterion
use is necessary before valid results can be developed and relied
on. Thus, the more technologically demanding criteria requires
more specialized user abilities.
3. Ease of Quantification - Ability to place a numerical value
or threshold on a criterion.
Comment - Certain criteria are expressed in numerical terms
such as TOT. Others such as those based on geologic or
hydrogeologic boundaries are more difficult to describe in such
terms in a regulation, etc. Consequently, the clarity of
communicating or legally defining criterion values varies widely.
4. Variability Under Actual Conditions - Extent to which an
area resulting from a criterion will vary with time due to
changes in hydrologic conditions.
Comment - Criteria, such as Time-of-Travel or drawdown
dimensions are influenced by variables which can change if the
III-8
-------
external conditions on which they are based, e.g., recharge
rates, also change. In contrast, an arbitrarily established
distance dimension will remain constant regardless of what site
specific changes might occur.
5. Field Verification - Ability to confirm values placed on a
criterion through actual on-site testing or inspection.
Comment - It is often very difficult to accurately reproduce
calculated values in the field, time-of-travel values for
example. Others can be reasonably confirmed through inspection
such as field checking the surface divide of a basin whose
boundaries were originally determined on a topographic map.
(Proving the ground-water extrapolation of this boundary is more
difficult.)
6. Ability to Reflect Ambient Ground-Water Standards - Degree
to which a criterion can be used to define the meeting of a
particular ground-water quality standard, either at the well or
at some location in the surrounding WHPA.
Comment - One consideration for selecting a WHPA criterion
is the potential for relating it to some overall water quality
standard (in the well or in ground water). Criteria, such as
assimilative capacity, may provide values which can be used to
closely approximate the concentration of contaminants and their
relation to acceptable limits. Others, however, such as an
arbitrary distance, will not (unless very extensive).
7. Suitability for Delineation Methods - Extent to which a
criterion can be specified on the ground through application of
particular methodologies (discussed in Section IV).
Comment - The viability of a method is dependent on the
specific set of criteria which form its basis. Arbitrary,
III-9
-------
analytical, calculated or geologic/geomorphic methods of WHPA
delineation inherently incorporate criteria in their application.
8. Criterion Development Cost - Expenses related to developing
criteria values.
Comment - The cost of developing a criterion.may inhibit or
encourage its use. Generally, criteria which are highly
technical, rely on a complex data base, or are labor intensive
will be expensive to produce. This may deter their application
and acceptance even though their validity may be great.
9. Suitability for Geologic Settings - The ability to apply a
criterion under a wide range of hydrogeologic conditions.
Comment - Hydrogeologic controls over ground water under
natural conditions vary widely. The extent of confinement,
consolidation, fracturing and solution channel development are
some of the major physical controls which may influence the
appropriateness and ease of criterion development.
D. Guide for Team Discussion Session
Introduction
The previous sections of this chapter discussed the program
goals and issues that are related to consideration of criteria
selection and use. Before the methods of WHPA delineation can be
addressed, the work group teams will focus their attention on the
types of criteria that exist, their appropriateness, how they
relate to the previously identified goals and issues and any
other points the team may wish to discuss.
Two separate items follow which should be individually
evaluated. The first is a list of six questions. The second is
111-10
-------
an issue question with four options. They are being provided to
you in order to facilitate team recommendations. EPA is very
interested in the opinions of participants on these issues;
therefore, it is hoped that you might provide your thoughts on
the options and as many of the questions as you can. The team
group is not restricted to only these materials and is free to
approach the subject in any manner it feels appropriate.
Remember, however, that the final summary should assess the
relevant issues in a manner that will facilitate EPA's efforts to
develop WHPA delineation criteria.
III-ll
-------
ITEM 1 - SIGNIFICANT QUESTIONS ON WHPA CRITERIA
A. ARE THE CRITERIA IDENTIFIED IN THE MATRIX VALID?
B. ARE THERE ADDITIONAL CRITERIA WHICH SHOULD BE LISTED?
C. ARE THERE OTHER EXAMPLES OF STATES OR LOCALITIES THAT
SELECT OR UTILIZE ADDITIONAL THRESHOLDS FOR CRITERIA?
D. HOW ADEQUATE ARE THE THRESHOLDS USED BY THE STATES AND
OTHERS?
E. ARE SOME CRITERIA MORE VALID FOR CERTAIN GEOLOGIC
SETTINGS? WHAT ARE THOSE SETTINGS?
F. WHAT ARE THE INHERENT ADVANTAGES AND DISADVANTAGES TO
EACH OF'THE SPECIFIC CRITERIA?
G. WHAT ARE "REASONABLE" SAFE DISTANCES, TOT VALUES AND
OTHER CRITERIA THRESHOLDS?
111-12
-------
ITEM 2 - ISSUE: HOW SHOULD EPA ESTABLISH THE PRINCIPAL
CRITERIA FOR ADEQUATE DELINEATION OF WELLHEAD PROTECTION
AREA?
An examination of the wellhead programs in Western
Europe and the few localities using or debating such
techniques in the United States, points to at least four
major program goals (Figure III-3). Each of these goals is
approached through the establishment of various technical
criteria which delimit the area of protection. The
underlying question that considerations should be related
to, is the extent to which EPA should establish national
goals and criteria for delineation. Six questions and four
general options will be evaluated in the team discussion
sessions. The options range from the least restrictive
approach to the States, to ones where EPA plays a more
active role in selecting the actual criteria used in
defining the goal.
Option 1 - All or nearly all goals and criteria for
delineation are adequate given different circumstances. The
States must defend the appropriateness of their choice, and
the specific criteria selected.
Advantages/Disadvantages
o Provides maximum flexibility required by the
Amendments;
o Recognizes that our knowledge in this field is
limited and provides a forum for improving basic
approaches;
o Greater chance of "overprotection"/"xinderprotection"
given State conditions.
111-13
-------
FIGURE III-3
BROAD GOALS AND CRITERIA
FOR DELINEATING WELLHEAD PROTECTION AREAS
GOALS
Provide a wellfield manage-
ment area in major portion
of recharge area
Provide a renovation zone
for contaminant attenuation
from sources to well
Provide a remedial action
zone to protect well
from unexpected contaminant
releases
Manage entire recharge area
under current and foresee-
able conditions
EXAMPLE CRITERIA
0.25 foot drawdown contour
(Dade Co. . Florida)
2Km/10-25 year TOT
(W. Europe)
Meet percentage of MCL in
raw water supplying well
5-year TOT to well
(State of Florida)
Physical limits of aquifer
and surface drainage
(some parts of
Massachusetts)
PRO
Broadest definition:
can be tailored by
States as appro-
priate; can incor-
porate other options
Most directly
addresses specific
contaminants of
concern and
"standard" in SDWA
Deals directly with
most threatening
sources in a manner
understandable to
regulated community;
"compatible" with
existing programs
Can be interpreted
as most protective;
especially appro-
priate to small
aquifers (e.g., less
than 10-20 square
miles)
CON
May lead to "over-
protection" in
some States;
"under-protection"
in others
Currently viable
only for simple
problems such as
microbial contam-
inants; conserva-
tive parameters
(e.g. , synthetic
organ ics more
problematic)
Implies capa-
bility/success
of corrective
action measures
at all relevant
sources
"Overprotective"
for moderate to
large aquifers
ADEQUACY OF DELINEATION
(HYDROGEOLOGY)
Based on reasonable
application of hydro-
geologic concepts to
data available.
Analysis sufficiently
thorough to show that
zone is extensive
enough to meet target
concentrations at well.
High confidence in
accuracy of time-of-
travel determinations
at specific wellhead
areas.
Analysis shows full
recharge area under
existing and potential
pumping scenarios.
IMPLEMENTATIONS FOR
"MANAGEMENT" PLAN ADEQUACY
Based on reasonable
consideration of relevant
management factors.
Displays understanding of
contamination sources,
locations, contaminant
characteristics, Impacts
of controls.
Possible ban of all high
risk activities within
WHPA; controls/monitoring
of all significant sources
within recharge area,
especially those beyond
WHPA.
"Controls" extend to all
potential contamination
sources within recharge
area.
-------
Option 2 - All or nearly all goals are adequate, but EPA
establishes "minimum adequate" criteria (e.g.. 1.000 foot
radius or 5-vear TOT).
Advantages/Disadvantages
o Provides a base level of protection which provides
a significant improvement over current levels;
o Provides some level of national consistency;
o Will be underprotective in certain settings, and
may present a difficult precedent for States who
wish to take a more protective approach;
o May not meet the full intent of the "standard."
Option 3 - All or nearly all goals are adeguate. but EPA
establishes or recommends significantly more protective
criteria (e.g.. 2 mile radius or 25 to 50 year TOT).
Advantages/Disadvantages
o Provides a moderate to high degree of protection
given current knowledge;
o More closely meets intent of "standard";
o Will be opposed by States considering more limited
criteria; public/private sector concerns of
"overregulation."
111-15
-------
Option 4 - Only one goal and set of criteria for delineation
are adequate (e.g.. provide 10 year TOT management area).
Advantages/Disadvantages
o Establishes most consistency among States;
o Provides easiest administrative test to approve
"adequacy;"
o Could range in protectiveness depending on goal/
criteria chosen;
o Least response to Amendment's emphasis on
flexibility; States may not pick up WHPA program;
o Greatest effort for EPA to determine appropriate
goal/criteria for entire nation.
111-16
-------
IV
-------
IV. METHODS FOR DELINEATING WHPAs
-------
CHAPTER IV
I. METHODS FOR DELINEATING WHPAs
Introduction
This chapter describes some of the methods that can be used
to apply a technical criterion in delineating a WHPA boundary.
In the development of its hydrogeologic guidance, the Agency
plans to analyze the strengths and limitations of each method
before recommendations can be developed as to where each one may
be most appropriate. Parallel efforts under the direction of
OGWP are presently addressing particularly management programs
within the zones of protection.
As previously discussed in Figure II-2, information has been
collected to determine how various water resource programs in the
United States and Western Europe implement their WHPA boundary
designation. The delineation methodologies obtained have been
categorized into seven general groups: Arbitrary Fixed Radii,
Calculated Fixed Radii, Simplified Variable Shapes, Analytical
Models, Geologic/Geomorphic Mapping, Numerical Flow/Transport
Models and Miscellaneous.
Figure IV-1 shows that more than one approach can be
utilized in the application of a single method. It also relates
the different approaches used to existing or proposed programs.
The various delineation methods essentially form a continuum
with three end points (Figure IV-2). The three points vary in
sophistication from the selection of arbitrary values, e.g., a
simple fixed radius with no scientific .basis; the utilization of
complex highly quantified approaches, e.g., analytical, numerical
models based on extensive site specific data; and more
descriptive approach of studying the physical features of an area
to determine the geologic or geomorphic controls on ground-water
IV-1
-------
WHPA METHODS
METHODS
ARBITRARY
FIXED
RADII
APPROACHES
ARBITRARY
CRITERIA
EXAMPLES
Nebraska
CALCULATED
FIXED
RADII
VOLUMETRIC
EQUATION AND
5 YEAR
TRAVEL TIME
Florida
SIMPLIFIED
VARIABLE
SHAPES
UNIFORM FLOW
APPROACH AND
50 DAY
TRAVEL TIME
•
Southern
Water
England
ANALYTICAL
MODELS
Uniform
Flow
Approach
and Sub-
regional
Flow
System
Uniform
Flow
Approach
and
Aquifer
Bounda-
ries
Cape Cod,
MA
Analytical
Time of
Travel
Equation
50 Day
Ouxbury,
MA
Edgartown,
MA
Germany
Holland
GEOLOGIC/
GEOMORPHIC
MAPPING
Mapping
Only
Mapping
(Based on
Yield)
Vermont
Mapping
Plus
Analytical
Flow
Model,
Land Use,
etc.
Conn.
NUMERICAL
FLOW/
TRANSPORT
MODELS
Numerical
10 day(tot)
30 davltot)
210day(tot)
or 1 ft.
Drawdown
Vermont
Mass.
Numerical
30 dayltot
ZIOdayltot
500day(tot
or 1 ft.
Drawdown
Dade and
Broward
County,
Florida
Palm
Beach
County,
Florida*
MISCEL-
LANEOUS
METHODS
Tracing
Analytical
Fate&
Transport
FIGURE IV-1
-------
INTERRELATIONSHIPS OF WHPA METHODS
QUANTITATIVE
ANALYTICAL, NUMERICAL
MODEL
FIXED
RADIUS
CALCULATED
FIXED
RADIUS
MODELED
REGIONAL
FLOW
ARBITRARY
FIXED RADIUS
WITH EXTENSION TO
REGIONAL DIVIDES
GEOLOGIC/
GEOMORPHIC
PHYSICAL
FEATURES
FIGURE IV-2
-------
flow. Intermediate methods are formed when combinations of
endpoints are made. WHPAs delineated by a calculated radius
based on generalized regional would be a combination of the
Arbitrary and Quantitative methods. Regional flow models can be
developed by combining the Quantitative and Physical Features
methods. An approach which starts with a fixed radius•and then
extends the area to a basin divide would combine the Arbitrary
and Physical Features methods. Numerous permutations can be
developed by combining two or three of the endpoints.
Description of WHPA Methods
A brief description of each method presented in Figure IV-1
is provided below:
1. Arbitrary Fixed Radii
General Description; This method is based on an "arbitrary"
selection of a circular area around a well to delineate a WHPA.
Although, at times, it may appear that the selection of the area
is not based on scientific principles, the area may have been
selected based on very generalized hydrogeologic considerations
and/or professional judgement. The threshold selected is
typically applied to all wells uniformly across a county, state,
or region.
Example; The state of Nebraska is delineating WHPA's by a
circle of 1,000 ft radius. Florida is proposing to use a 200 ft.
radius for its Zone I; Duxbury, MA., uses a 400 ft. radius for
its Zone I; and Edgartown, MA., used a 2,500 ft. radius for its
preliminary zone (until a more detailed analytic method is
available).
IV-4
-------
2. Calculated Fixed Radii
General Description: This method is based on the use of an
equation to compute a fixed radius for a circular area of
protection around a well or wellfield.
Example; Zone II of Florida's proposed two zone system is
defined as a circle of a radius calculated using a volumetric
equation that incorporates a time of 5-years, the well pumping
rate, and aquifer porosity and saturated thickness.
3. Simplified Variable Shapes
General Description; Any method which attempts to
incorporate site specific characteristics will result in an
infinity of sizes and/or shapes. This method attempts to
simplify the condition by selecting a small number of
representative areal forms from the large array of potential
possibilities. These standardized forms are then applied where
ranges of conditions fit into appropriate categories, e.g., a
form of predesignated shape and size is used for a specified
range of well yield.
Example; This method of delineating WHPAs is most popular
in Europe. For example, a water authority in Southern England
uses methods which are based on uniform flow and time of travel
equations in determining WHPAs. In these instances, the shapes
of the "standardized" forms are developed by applying the
analytical ground-water flow equations to sets of representative
hydrogeologic parameters, e.g., generalized aquifer properties,
directions of ground-water flow, hydraulic gradients and well
yields.
IV-5
-------
4. Analytical Models
General Description; This method is based on the use of
equation(s) .to define ground-water flow or contaminant transport.
For example, a general approach often-used defines the area of
contribution to a pumping well .in a sloping water table, i.e.,
the uniform flow equations (Todd, 1980).1
Example; Edgartown, MA, calculates the downgradient
stagnation point and the envelope of the area of contribution
using the uniform flow equations. The upgradient limit is set as
the upgradient regional ground-water divide. Duxbury, MA
delineates its Zone II using the uniform flow model to calculate
distance to the downgradient stagnation point and the envelope of
the area of contribution. The upgradient limit of Zone II is
drawn as the geologic contact between the unconsolidated aquifer
and bedrock having low permeability.
Cape Cod, MA uses a mass-balance approach in conjunction
with pumping test data and analytical equations to determine the
WHPA.
5. Geologic/Geomorphic Mapping (Combined with Analytical Flow
Models. Fixed Radii. Aquifer Yield)
General Description; Geologic/geomorphic mapping is used to
delineate the possible physical boundaries of the hydrogeologic
system. Boundaries of WHPAs are in some cases divided into
primary and secondary protection areas. Primary areas are
delineated by known or inferred radii of influence based on
simple formulae for various hydrogeologic settings. The
applicable method used to outline the primary area depends upon
Todd, O.K., 1980, Groundwater Hydrology, John Wiley &
Sons, Inc.
IV-6
-------
aquifer type and the availability of site specific data. When
data on aquifer parameters and/or information on ground-water
recharge are available, simple analytical equations are used.
When the data are not available, the primary area is drawn using
circles of arbitrary distance around the well and/or geologists'
experience. Secondary areas extend from the primary areas
upslope, primarily based on surficial topography and the location
of surface water divides.
Example; Vermont utilizes a method in which
geologic/geomorphic mapping is combined with simplified fixed-r
ring calculations that are then modified by regional flow
information. The Midstate Regional Planning Agency in
Connecticut mapped its WHPAs using aquifer yield information and
surface water basin morphology. Duxbury, MA also utilizes basin
morphology to define the upgradient recharge area for its Zone
III.
6. Numerical Flow/Transport Models
General Description; Numerical flow/transport models are
used to delineate well field protection areas. This is done
where boundary conditions are such that analytical models may not
provide accurate results or in areas where the importance of the
delineation warrants the most sophisticated or costly tools. The
use of numerical models to delineate WHPAs is usually
accomplished in two steps. First a hydraulic head field
distribution is generated with a numerical flow model under a
prescribed set of hydrologic conditions. The travel-distance
zones are delineated using a solute transport model based in part
on the hydraulic head field generated in the first step as input.
Example; The Florida counties of Broward, Bade and Palm
Beach utilize a time of travel criterion to delineate their zones
of protection. Palm Beach uses a 30 day travel time for Zone I, a
IV-7
-------
210 day travel time for Zone II and the greater of a 500 day
travel time or a one foot drawdown contour for its Zone III.
Broward and Bade Counties use travel times of 10 days, 30 days
and 210 days (or 1 foot drawdown if larger) to designate their
zones (NW wellfield in Bade County is based on 1/4' drawdown
contour and/or an approximate 25-40 year TOT.)
7. Miscellaneous Methods
General Bescription; All of the WHPA delineation methods
reviewed which are in current use or being proposed can be
grouped in one of the previous six methodology categories.
Consequently, only methods which are not normally associated with
WHPA designation but which may have potential use are mentioned
here.
Two methods may warrant future consideration, tracing (e.g.,
Isotope Study) and analytical fate and transport modeling. Each
has been used in research or specific problem solving usually
related to activities such as Karst ground-water flow analysis
and characterization of pollution dispersion. The agency would
be interested in knowing the suitability and application of these
or other miscellaneous methods.
Matrix of WHPA Methods/Evaluation Factors
A matrix (Figure IV-3) has been developed to compare
delineation methods against a number of evaluation factors that
could influence the selection and/or application of a WHPA
method. The blocks have been completed with proposed values for
consideration by workshop participants. The factors used to
evaluate the methods are defined as follows:
1. Ability to Understand the Method - Degree to
which the principles underlying the method
can be readily understood by hydrogeologist and non-
technical people.
IV-8
-------
(
WHPA METHODS/EVALUATION FACTORS
METHOD
1. ARBITRARY FIXED
RADIUS
2. CALCULATED FIXED
RADIUS
3. SIMPLIFIED
VARIABLE SHAPES
4. ANALYTICAL
FLOW MODELS
5. GEOLOGIC/
GEOMORPHIC
MAPPING
6. NUMERICAL FLOW/
TRANSPORT MODELS
7. MISCELLANEOUS
METHODS (TRACING)
ABILITY TO
UNDERSTAND
METHOD
L/M/H
T N
H
H
H
M-H
M-H
M
IVH
H
H
M-H
L-M
L-M
L
tt-H
USER
SOPHISTI-
CATION
L/M/H
L
L
L-n
M-H
M-H
H
M
EXTENT
OF USE
L/M/H
M-H
L-M
L
H
M
L-h
L
EXTENT
OF INPUT
DATA
REQUIRED
L/M/H
L
L-M
L
M
M-H
M-H
M
ABILITY TO
INCORPO-
RATE
DIFFERENT
HYDRO-
GEOLOGIC
CONDITIONS
L/M/H
L
L
L-M
M-H
M-H
M-H
L-tA
ACCU-
RACY
L/M/H
L
L
L-M
M
M-H
M-H
H
TIME TO
IMPLEMENT
METHOD
L/M/H
L
L
M
h
M-H
H
h
COST
L/M/H
L
L
L-tt
A1
M
M-H
L-M
DEGREE TO
WHICH THE
TECHNICAL
BASIS
CAN BE
CHALLENGED
L/M/H
H
H
M-H
M
L-M
L-M
L-M
L-LOW T-TECHNICAL
M-MEDIUM N-NON TECHNICAL
H-HIGH
FIGURE IV-3
-------
2. User Sophistication - Technical abilities of
user necessary to understand the basis of the
method and the input data requirements, to
apply the method, and to evaluate method
results.
3. Extent of Use - Identifies how commonly the
method is used, e.g., whether it is presently
used by regulatory agencies or in the process
of being adopted.
4. Extent of Input Data Required - Amount and
type of data required for method application;
data may be site-specific (i.e., developed
specifically for method application) or
regional (i.e., approximate and already
available).
5. Ability to Incorporate Different
Hydroaeologic Conditions - Capabilities of
the method to be applied to varied
hydrogeologic conditions, such as "sources"
and "sinks," boundary conditions, or variable
aquifer parameters.
6. • Accuracy - Degree to which the results from
method application can be expected to compare
with actual field conditions.
7. Time to Implement Method - Time required to
adequately apply the method and evaluate
results, in accordance with the qualitative,
analytical, or numerical characteristics of
the method.
IV-10
-------
8. Cost - Relative cost incurred in applying the method to
one wellhead, well field, or main fields in a state, in
terms of data acquisition, professional labor, computer
time, graphics, reporting, etc.
9. Degree to Which Technical Basis can be
Challenged - Degree to which the principles,
accuracy and applicability of the method can
be questioned by hydrogeologists and other
technical people.
Team Discussion Session
Introduction
During this discussion session, team participants will be
asked to focus on the merits of the different methods, the
conditions under which they might be suitable, and decision
making options that relate to methodology selection. The
participant should review the matrix carefully, since many
questions will be focused on this item.
A list of eight significant questions follows to help guide
team discussions. Participant input is desired on as many of
them as possible in the time available. Input and experience of
the participants on other method-related information would also
be valuable.
IV-11
-------
SIGNIFICANT QUESTIONS ON WHPA METHODS
A. HAVE ANY METHODS BEEN MISSED THAT YOU KNOW ARE BEING
USED SOMEWHERE? BY WHOM?
B. IS THIS EVALUATION OF METHODS CORRECT IN YOUR
EXPERIENCE AND WHAT CHANGES WOULD YOU MAKE IN THE
MATRIX?
C. ARE THERE OTHER FACTORS WHICH WE SHOULD USE TO EVALUATE
THE METHODS (FIGURE IV-3)?
D. WHAT ARE THE MAJOR WEAKNESSES AND STRENGTHS OF THE
DIFFERENT DELINEATION METHODS?
E. WHAT ROLE SHOULD EPA PLAY IN THE SELECTION OF
APPROPRIATE DELINEATION METHODS?
F. SHOULD A PHASED APPROACH TO METHOD SELECTION (E.G., AN
ARBITRARY FIXED RADIUS REPLACED BY A CALCULATED ZONE AS
MORE SITE SPECIFIC INFORMATION BECOMES AVAILABLE) BE
UTILIZED? HOW WOULD IT BE STRUCTURED AND IMPLEMENTED?
G. WHAT METHOD PROVIDES THE MOST PROTECTION? THE LEAST?
H. SHOULD DELINEATION METHOD REQUIREMENTS BE RELATED TO
DIFFERENT WELL SIZES OR NUMBERS OF USERS DEPENDENT ON A
WELLHEAD? WHAT ELEMENTS SHOULD BE CONSIDERED AND HOW
SHOULD SUCH METHODS BE STRUCTURED?
IV-12
-------
V
-------
V.
CROSS-CUTTING ISSUES
-------
CHAPTER V
CROSS-CUTTING ISSUES
The previous chapters dealt specifically with questions
concerning the guidance that EPA should develop to assist states
in the delineation of WHP areas. The determination of the WHPA
represents only one of the activities a state must undertake in
developing a state WHP program that will be eligible for federal
funding, as can be seen in Figure V-I below.
In another workshop to be held next week, participants will
focus on the other five activities that make up a state's efforts
in designing a WHP program.
FIGURE V - 1
Major Stages in Developing and
Implementing a State WHP Program
PROGRAM
DESIGN:
Definition
of an'Aflequate'
Program
ACTIVITIES:
Designation of
i •
Inventory
the Sources
Define
Contaminants
Assessment of
Potential
Ttireat
Define
Sources
Management
and
Control
ROLES AND
RELATIONSHIPS:
Institutional
Considerations
In addition to specific technical considerations, the EPA
would like each workshop to address what it refers to as
cross-cutting issues. These additional issues, which are
highlighted in Figure V-I above, are the definition of an
adequate state WHP program and a review of institutional
considerations, specifically the relationship among federal,
state and local governments, that must be addressed in designing
and implementing a WHP program.
Consideration of these questions is important to
participants in both workshops if they are -to adequately advise
EPA on the development of guidances for both the hydrogeologic
criteria and management protection plans.
-------
V - 2
DEFINITION OF AN "ADEQUATE" STATE WHP PROGRAM
This chapter first addresses the orientation of an "adequate"
program to protect wellhead areas. According to Webster,
"adequate" is defined as sufficient for a specific requirement, or
as barely sufficient. EPA is not, then, charged with approving and
providing funds for the best possible program, but for a
satisfactory one. The guidance will, by necessity, allow for a
great deal of flexibility on the part of various states to develope
programs that adequately meet the goals of the Act; those that do
are eligible to receive funds.
In this part of the session, participants will address two
questions. The first is the key issue in determining whether or not
the Administrator will approve a state-submitted program:
1. Which general programmatic approaches should EPA view as
adequate?
The second considers the timing of actions taken in a state
program:
2. On what basis may an adequate state program phase-in its
delineation of wellheads and identification of sources?
-------
V - 3
ISSUE 1. WHICH PROGRAMMATIC APPROACHES SHOULD EPA VIEW AS
ADEQUATE?
According to the statute, the EPA Administrator must
disapprove a State program, or any portion of it, which is not
adequate to protect public water systems from contaminants which
may have any adverse effect on human health. In addition to this
rather explicit statutory directive, the Congress has also directed
EPA, in the conference report that accompanied passage of the law,
to give states a great deal of flexibility in defining wellhead
protection areas (WHPAs) and attendant protection programs. In the
guidance, EPA must determine what overall standard it will use to
determine whether a state program is "adequate" to meet the goals
of the Act.
This general view of "adequacy" will have implications for
the options discussed in later sessions on questions such as which
potential contaminants and sources should be identified and what
control measures should be applied.
Unlike later issues, where one or a few options may clearly be
best for a particular issue, the question of what makes an adequate
program has no single answer. There are many forms that an
adequate program could take: it could be linked to a specific
standard of ground-water quality, or it could be based on applying
certain management practices to various potential pollutants.
In order to help OGWP develop its guidance on this matter,
workshop participants will address the following question — should
EPA view the following programmatic approaches as adequate? If
yes, are there certain conditions or circumstances under which a
particular approach may not be adequate?
Given the breadth of this first issue, participants may
conclude that all of the following options are acceptable; on the
other hand, some may not fit in. Participants are encouraged to
develop additional options as well. In reviewing any options,
participants should consider the feasibility of implementing
various options, and the statutory language.
Option 1 - One which provides for no degradation of ground-water
quality
Advantages
• Would theoretically provide the highest level of protection
to the ground-water resource and drinking water supply
• A number of states currently use this standard for the
entire state or for highly sensitive areas
-------
V - 4
Disadvantages
• Implementation may well be infeasible in urban settings and
beyond the financial and technical capacity of states and
local entities
• States would have to develop elaborate models to show the
program was working
Option 2 - One which provides wellhead protection by achieving
drinking water standards for raw water entering the wellhead
Advantages
• Allows flexibility for source control measures as long as
standards are met at the wellhead
• Extends requirements of the Act for finished water to raw
water at the wellhead
Disadvantages
• Protects drinking water, but not necessarily the
ground-water resource as a whole
• Does not address contaminants for which drinking water
standards have not been issued
• States would have to develop models to apply this approach
• May be infeasible in urban and other areas
Option 3 - One which improves raw water quality to the extent that
drinking water standards may be met using existing drinking water
treatment technology'
Advantages
• Easy to implement
• Would ensure that drinking water at the tap meets standards
Disadvantages
• May be inconsistent with the goals of the Act
• May discourage innovative source controls and encourage
treatment of raw water
• Does not address contaminants for which there are no
drinking water standards
• Inconsistent with most Federal and State ground-water
programs which do not permit degradation of current
drinking water supplies below drinking water standards
-------
V - 5
• Nearly all small systems drawing from ground water lack the
ability to finance or maintain the sophisticated level of
treatment needed to remove man-made chemicals
Option 4 - One which applies best management practices (BMP)/best
engineering judgment (BEJ) to all sources of contamination within
the WHPA
Advantages
• Focuses on attainment of technically and economically
feasible quality standards in a given location
• Is similar to approach used in other EPA programs such as
the Clean Air Act and Clean Water Act
Disadvantages
• BMP/BEJ may not lead to adequate levels of contaminants in
ground water
• Requires definition of BMP/BEJ for a variety of sources
Option 5 - One that the State demonstrates is comparable with the
approach of an adequate program as defined by the Technical
Committee
Options 5 and 6 differ from the first four since adequacy is
measured more subjectively. The first four options link adequacy
to measurable indicators of water quality or to application of
technology standards. Option 5 presumes development, by EPA's
management protection plan committee, of a program scenario
composed of elements selected from review of the options presented
in both workshops. The State must then demonstrate how its program
elements will produce effects similar to the EPA scenario.
Advantages
• The State is not limited to an overall goal that is
infeasible or impractical in some cases
Disadvantages
• States must demonstrate how the effects of their approach
compare with the effects of an acceptable program
• The program must describe the actions to be taken and their
implementation; states could expand considerable effort in
program development and rationalization
-------
V - 6
Option 6 - One that the State certifies has an objective that meets
the statute's goal and its six specific elements
Like Option 5, Option 6 proposes a more subjective measure of
adequacy. The State does not follow specific EPA guidelines, but
instead certifies that its program will achieve the goal of the Act
and includes the six elements listed in Section 1428(a).
Advantages
• Most flexible for the state
Disadvantages
• EPA would have difficulty ascertaining the effectiveness of
the program
• States would lack a basis on which to judge EPA's action on
their applications
-------
V - 7
ISSUE 2; ON WHAT BASIS MAY AN ADEQOATB STATE PROGRAM PHASE IN ITS
DELINEATION OF WELLHEADS AND IDENTIFICATION OF SOURCES?
Section 1428(a) states that:
"The Governor or Governor's designee of each State shall,
within 3 years of the date of enactment of the Safe
Drinking Water Act Amendments of 1986, adopt and submit to
the Administrator a State program to protect wellhead ares
within their jurisdiction from contaminants which may have
any adverse effect on the health of persons."
Subsection 1428(d) further states that:
"After the date 3 years after the enactment of this
section, no State shall receive funds authorized to be
appropriated under this section except for the purpose of
implementing the program...."
The statute provides that after June 1989 States may receive
funds only to implement'their EPA-approved WHP programs that meet
each of the program elements described in subsection 1428(a).
States, therefore, will be ineligible for development funding after
year three. In order.to qualify for implementation funding, States
will be required to submit their developed program plans to EPA for
review and approval by the end of FY 89. Approved plans, then, will
be eligible to receive implementation funding for subsequent program
years.
EPA may have some latitude in interpreting the program
requirements in subsection 1428(a) that States must meet in order to
qualify for funding after FY 89. In considering this issue, EPA has
determined that four of the six requirements present little problems
in determining what must be required by year three. For example,
1428(a)(1) requires States to specify the duties of governmental
entities that will have a part in the development and implementation
of the State WHP program; States, therefore, would be required to
provide EPA with a listing of each governmental unit involved. Such
a requirement would place little burden on the State and is feasible
within three years. A more complicated requirement is in Section
1428(a)(3):
"identify within each wellhead protection area all
potential anthropogenic sources of contaminants...."
These options deal with the timing of this requirement.
-------
V - 8
Option 1 - Within three years states must identify each WHPA around all
public water systems^ within its borders and identify specifically
all sources of anthropogenic pollution within each wellhead; all
activities for these elements are ineligible for funding after FY 89
Advantages
• Is the simplest option for which to provide implementation
guidance to States
• Requires States to expedite their programs and would speed
actual work for addressing potential WHP problems
• May help direct WHP funds to implementation rather than
program development
Disadvantages
• Is not an implementable option in most States
• Does not take into account the limited amount of funds that
States will probably receive and have available within the
State to accomplish these actions
• Stresses completion of the program at the expense of more
thorough planning and priority setting
• May limit State participation in the WHP program because
the requirements are too strict
Option 2 - Within three years states must determine, through a
mechanism such as a general rule, all WHPAs within its borders~and
identify generically all sources of anthropogenic pollution within
each wellhead
Advantages
• States may refine (e.g., more fully characterize specific
characteristics of WHPAs) these elements after FY 89 as a
part of program implementation
• May help direct WHP monies to implementation rather than
development; also would help expedite the actual "field
• work" of delineating and inventorying
• Better takes into account a State's financial and other
resource limitations
Public water systems include community water supply systems
and non-community water supply systems, e.g., truck stops,
restaurants, schools.
-------
V - 9
Disadvantages
• Presents problems in strictly definng "development" vs.
"implementation" in guidance to recipients/applicants. Also
may complicate EPA audits of recipients' financial records,
since it may be very difficult to distinguish where development
ends and implementation begins
• May limit State participation in the WHP program because the
requirements are too strict
• May still be impractical to implement
Option 3 - Within three years states must determine WHPAs only for
large (e.g., serving over 500 people) community water systems, and
reserve smaller CWS and non-GWS for FY 90 and after; contamination "
sources are addressed generically
Advantages
• Provides clear priority for areas with higher population
risk
• More realistic to implement
• Consistent with rules regarding public water system testing
and State well registration programs
Disadvantages
• Phasing is inconsistent with statute
• Ignores factors other than population that may increase risk
in a wellhead
Option 4 - Within three years states must submit only plans for
determining WHPAs and identifying pollution sources; costs for
developing these plans are ineligible for funding after FY 89, but
States can receive funding for implementing these plans later
Advantages
• More time available to set priorities
• Takes into account States' differing capabilities, resource
availability, and workloads
• Will allow for more State participation in the WHP program
than either Option 1 or 2
Disadvantages
• Does not fulfill the statutory requirements of Section
1428(d)
-------
V - 10
• Directs a higher proportion of WHP authorized funds to
planning rather than delineating wellhead areas and
inventorying sources
• Like Option 2, may pose a problem to EPA in defining the
exact point where development ends and implementation
begins
-------
V - 11
INSTITUTIONAL CONSIDERATIONS
During the remainder of this session of the workshop,
participants will be asked to address the final topics of concern,
namely the roles and relationships of state and local authorities
in effectively implementing and enforcing a wellhead protection
program. The key questions are:
1. To what extent would an adequate program make use of or
enhance existing state and local programs and regulatory
requirements to carry out protection for WHP areas?
2. To what extent must the implementing agency demonstrate,
in the program application, its ability to ensure
coordination in implementation of the plan by appropriate
state and local entities?
The applicable statutory language, Subsection 1428(a),
requires that an adequate program:
"specify the duties of state agencies, local governmental
entities, and public water supply systems with respect to
the development and implementation of programs required
by this section."
Underlying these issues is EPA's recognition of the
sensitivity that it must bring to bear in dealing with the state
and local governments in areas such as land use and ground-water
protection. To the extent possible, EPA wants to ensure that the
WHP program is administered in a manner that is consistent with
existing State ground-water protection strategies and plans.
The major question for participants to address is how does
EPA, while respecting the primary role of the states, ensure'that
sufficient coordination will occur to allow for the implementation
of an adequate program?
-------
V - 12
ISSUE 3 - TO WHAT EXTENT WOULD AN ADEQUATE PROGRAM MAKE CJSE OF OR
ENHANCE EXISTING STATE AND LOCAL PROGRAMS AND REGULATORY
REQUIREMENTS TO CARRY OUT PROTECTION FOR WHP AREAS
The subquestion to this issue is, in implementing an adequate
program, should the state create a new agency or institution, or
should it employ existing state and local programs.
Option 1 - An adequate program will utilize, to the maximum extent
possible, existing state statutes, regulations, and agencies
Advantages
• No need for new state bureaucracy
• Avoids duplication of effort
• More expeditious implementation
Disadvantages
• May have program conflicts within existing agencies
• May lack authority in dealing with non-related state
agencies or with federal agencies
Option 2 - Encourage, where possible, new institutions to implement
the programs
Advantages
• Institutions could be specifically tailored to the needs of
the program
Disadvantages
• Could lead to duplication of effort with existing State and
local programs
• May be more costly to the states
Option 3 - An adequate program need not address this question
Advantages
• Maximum flexibility to state
-------
V - 13
Disadvantages
• Could limit integration with existing state program
• Would not fulfill statutory requirement to indicate the
roles of state and local agencies in developing and
implementing the programs
-------
V - 14
ISSUE 4 - TO WHAT EXTENT MUST THE IMPLEMENTING AGENCY DEMONSTRATE,
IN THE PROGRAM APPLICATION, ITS ABILITY TO ENSURE COORDINATION IN
IMPLEMENTATION OF THE PLAN BY APPROPRIATE STATE AND LOCAL ENTITIES
Implementation of an adequate program may well require that a
number of diverse agencies and services operate together in new
ways. For example, local zoning agencies may have to coordinate
efforts with public health agencies.
The means of achieving such coordination could include:
• New state legislation authorizing a designated implementing
agency to manage and coordinate all State agencies and
local entities for the purposes of carrying out the WHP
program
• A Governor's executive order establishing a special task
force, commission or oversight committee to manage and
coordinate all State agencies and local entities
participating in the WHP program
• A Governor's designation of a lead agency to manage and
coordinate all State agencies and local entities
participating in the WHP program
In all cases, the test of adequacy will be whether there is
sufficient management and coordination authority to administer the
program's operational requirements.
Option 1 - Require that the identified State Implementing Agency
demonstrate some statutory authority by which it can manage and
coordinate the program among all participating entities
Advantages
• Would provide a legal basis for adequate program management
and coordination among several agencies and entities at
both the State and local levels of activity
Disadvantages
• May not be legally feasible
• May take too long
Option 2 - Require a demonstration of some administrative mechanism
(e.g., a Governor's Task Force or Oversight Committee) by which
program management and coordination will occur
Advantages
• Could provide adequate program management and coordination
without need for new legislation
-------
V - 15
Disadvantages
• May not be effective without statutory underpinning
Option 3 - Require identification of a lead agency to be
responsible for managing and coordinating the efforts of program
implementation
Advantages
• Is the simplest means of providing program management and
coordination
Disadvantages
• Mere designation of a lead agency may not adequately ensure
needed coordination
• May cause "turf" problems within a state
Option 4 - Require no showing of management and coordination
ability; simply require a listing of duties by Agency or
jurisdiction
Advantages
• Maximum flexibility "to the states
Disadvantages
• This option is the least liTcely to provide adequate program
management and coordination
-------
VI
-------
APPENDIX A: Safe Drinking Water Act Ammendments of 1986
-------
17
SEC. t03. SOLE SOURCE 4QUIFEK DEMONSTRATION PROGRAM.
Part C of the Safe Drinking Water Act is amended by adding the
following new section after section 1426:
"SEC. HIT. SOLE SOURCE AQUIFER DEMONSTRA TION PROGRAM.
"(a) PURPOSE.—The purpose of this section is to establish proce-
dures for development, implementation, and assessment of demon-
stration programs designed to protect critical aquifer protection
areas located within areas designated as sole or principal source
aquifers under section 1424(e) of this Act.
"(b) DEFINITION.—For purposes of this section, the term 'critical
aquifer protection area' means either of the following:
' (1) All or part of an area located within an area for which
an application or designation as a sole or principal source aqui-
fer pursuant to section 1424(e), has been submitted and ap-
proved by the Administrator not later than 24 months after the
enactment of the Safe Drinking Water Act Amendments of 1986
and which satisfies the criteria established by the Administra-
tor under subsection (d).
"(2) All or part of an area which is within an aquifer desig-
nated as a sole source aquifer as of the enactment of the Safe
Drinking Water Act Amendments of 1986 and for which an
areawide ground water quality protection plan has been ap-
proved under section 208 of the Clean Water Act prior to such
enactment.
"(c) APPLICATION.—Any State, municipal or local government or
political subdivision thereof or any planning entity (including any
interstate regional planning entity) that identifies a critical aquifer
protection area over which it has authority or jurisdiction may
apply to the Administrator for the selection of such area for a dem-
onstration program under this section. Any applicant shall consult
with other government or planning entities with authority or juris-
diction in such area prior to application. Applicants, other than the .
Governor, shall submit the application for a demonstration program
jointly with the Governor.
"(d) CRITERIA.—Not later than 1 year after the enactment of the
Safe Drinking Water Act Amendments of 1986, the Administrator
shall, by rule, establish criteria for identifying critical aquifer pro-
-------
18
lection areas under this section. In establishing such criteria, the
Administrator shall consider each of the following:
"(1) The vulnerability of the aquifer to contamination due to
hydrogeologic characteristics.
"(2) The number of persons or the proportion of population
using the ground water as a drinking water source.
"(3) The economic, social and environmental benefits that
would result to the area from maintenance of ground water of
high quality.
"(4) The economic, social and environmental costs that would
result from degradation of the quality of the ground water.
"(e) CONTENTS OF APPLICATION.—An application submitted to the
Administrator by any applicant for a demonstration program under
this section shall meet each of the following requirements:
"(1) The application shall propose boundaries for the critical
aquifer protection area within its jurisdiction.
"(2) The application shall designate or, if necessary, establish
a planning entity (which shall be a public agency and which
shall include representation of elected local and State govern-
mental officials) to develop a comprehensive management plan
(hereinafter in this section referred to as the 'plan') for the criti-
cal protection area. Where a local government planning agency
exists with adequate authority to carry out this section with re-
spect to any proposed critical protection area, such agency shall
be designated as the planning entity.
"(3) The application shall establish procedures for public par-
ticipation in the development of the plan, for review, approval,
and adoption of the plan, and for assistance to municipalities
and other public agencies with authority under State law to im-
plement the plan.
"(4) The application shall include a hydrogeologic assessment
of surface and ground water resources within the critical protec-
tion area.
"(5) The application shall include a comprehensive manage-
ment plan for the proposed protection area.
"(6) The application shall include the measures and schedule
proposed for implementation of such plan.
"(f) COMPREHENSIVE PLAN.—
"(1) The objective of a comprehensive management plan sub-
mitted by an applicant under this section shall be to maintain
the quality of the ground water in the critical protection area in
a manner reasonably expected to protect human health, the en-
vironment and ground water resources. In order to achieve such
objective, the plan may be designed to maintain, to the maxi-
mum extent possible, the natural vegetative and hydrogeological
conditions. Each of the following elements shall be included in
such a protection plan:
(A} A map showing the detailed boundary of the critical
protection area.
"(E) An identification of existing and potential point and
nonpoint sources of ground water degradation.
(C) An assessment of the relationship between activities
on the land surface and ground water quality.
19
"(D) Specific actions and management practices to be im-
plemented in the critical protection area to prevent adverse
impacts on ground water quality.
'(E) Identification of authority adequate to implement
the plan, estimates of program costs, and sources of Stale
matching funds.
"(2) Such plan may also include the following:
"(A) A determination of the quality of the existing
ground water recharged through the special protection area
and the natural recharge capabilities of the special protec-
tion area watershed.
"(B) Requirements designed to maintain existing under-
ground drinking water quality or improve underground
drinking water quality if prevailing conditions fail to meet
drinking water standards, pursuant to this Act and State
law.
"(C} Limits on Federal, State, and local government, fi-
nancially assisted activities and projects which may con-
tribute to degradation of such ground water or any loss of
natural surface and subsurface infiltration of purification
capability of the special protection watershed.
"(D) A comprehensive statement of land use management
including emergency contingency planning as it pertains to
the maintenance of the quality of underground sources of
drinking water or to the improvement of such sources if
necessary to meet drinking water standards pursuant to
this Act and State law.
"(E) Actions in the special protection area which would
avoid adverse impacts on water quality, recharge capabili-
ties, or both.
"(F} Consideration of specific techniques, which may in-
clude clustering, transfer of development rights, and other
innovative measures sufficient to achieve the objectives of
this section.
"(G) Consideration of the establishment of a State insti-
tution to facilitate and assist funding a development trans-
fer credit system.
"(H) A program for State and local implementation of
the plan described in this subsection in a manner that will
insure the continued, uniform, consistent protection of the
critical protection area in accord with the purposes of this
section.
"(I) Pollution abatement measures, if appropriate.
"(g) PLANS UNDER SECTION 208 OF THE CLEAN WATER ACT.—A
plan approved before the enactment of the Safe Drinking Water Act
Amendments of 1986 under section 208 of the Clean Water Act to
protect a sole source aquifer designated under section 1424(e) of this
Act shall be considered a comprehensive management plan for the
purposes of this section.
(h) CONSULTATION AND HEARINGS.—During the development of a
comprehensive management plan under this section, the planning
entity shall consult with, and consider the comments of, appropriate
officials of any municipality and State or Federal agency which has
jurisdiction over lands and waters within the special protection
-------
20
area, other concerned organizations .and technical and citizen advi-
sory committees. The planning entity shall conduct public hearings
at places within the special protection area for the purpose of pro-
viding the opportunity to comment on any aspect of the plan.
"(i) APPROVAL OR DISAPPROVAL.—Within 120 days after receipt of
an application under this section, the Administrator shall approve
or disapprove the application. The approval or disapproval shall be
based on a determination that the critical protection area satisfies
the criteria established under subsection (d) and that a demonstra-
tion program for the area would provide protection for ground water
quality consistent with the objectives stated in subsection (f). The
Administrator shall provide to the Governor a written explanation
of the reasons for the disapproval of any such application. Any peti-
tioner may modify and resubmit any application which is not ap-
proved. Upon approval of an application, the Administrator may
enter into a cooperative agreement with the applicant to establish a
demonstration program under this section.
"(j) GRANTS AND REIMBURSEMENT.—Upon entering a cooperative
agreement under subsection (i), the Administrator may provide to
the applicant, on a matching basis, a grant of 50 per centum of the
costs of implementing the plan established under this section. The
Administrator may also reimburse the applicant of an approved
plan up to 50 per centum of the costs of developing such plan, except
for plans approved under section 208 of the Clean Water Act. The
total amount of grants under this section for any one aquifer, desig-
nated under section 1424(e), shall not exceed $4,000,000 in any one
fiscal year.
"(k) ACTIVITIES FUNDED UNDER OTHER LAW.—No funds author-
ized under this subsection may be used to fund activities funded
under other sections of this Act or the Clean Water Act, the Solid
Waste Disposal Act, the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 or other environmental
laws.
"(1) REPORT.—Not later than December 31, 1989, each State shall
submit to the Administrator a report assessing the impact of the
program on ground water quality and identifying those measures
found to be effective in protecting ground water resources. No later
than September 30, 1990, the Administrator shall submit to Con-
gress a report summarizing the State reports, and assessing the ac-
complishments of the sole source aquifer demonstration program in-
cluding an identification of protection methods found to be most ef-
fective and recommendations for their application to protect ground
water resources from contamination whenever necessary.
"(m) SAVINGS PROVISION.—Nothing under this section shall be
construed to amend, supersede or abrogate rights to quantities of
water which have been established by interstate water compacts, Su-
preme Court decrees, or State water laws; or any requirement im-
posed or right provided under any Federal or State environmental
or public health statute. ".
SEC. 104. EMERGENCY POWERS.
Section 1431 of the Safe Drinking Water Act is amended as fol-
lows:
21
(1) In the first sentence of subsection (a) add the words "or an
underground source of drinking water" after the words "to
enter a public water system ".
(2) In the last sentence of subsection (a} add "including orders
requiring the provision of alternative water supplies by persons
who caused or contributed to the endanger men t," after the
words "including travelers),".
(3) In subsection (b):
(A) Strike "willfully".
(B) Strike "fined not more than " and insert in lieu there-
of "subject to a civil penalty of not to exceed".
SEC. 205. STATE PROGRAMS TO ESTABLISH WELLHEAD PROTECTION
AREAS.
The Safe Drinking Water Act is amended by adding the following
new section after section 1427, as added by section 203 of this Act:
"SEC. 1428. STATE PROGRAMS TO ESTABLISH WELLHEAD PROTECTION
AREAS.
"(a) STATE PROGRAMS.—The Governor or Governor's designee of
each State shrill, within 3 years of the date of enactment of the Safe
Drinking Vfare» Act Amendments of 1986, adopt and submit to the
Administrator a State program to protect wellhead areas within
their jurisdiction from contaminants which may have any adverse
affect on the health of persons. Each State program under this sec-
tion shall, at a minimum—
"(1) specify the duties of State agencies, local governmental
entities, and public water supply systems with respect to the de-
velopment and implementation of programs required by this sec-
tion;
"(2) for each wellhead, determine the wellhead protection
area as defined in subsection (e) based on all reasonably avail-
able hydrogeologic information on ground water flow, recharge
and discharge and other information the State deems necessary
to adequately determine the wellhead protection area;
"(3) identify within each wellhead protection area all poten-
tial anthropogenic sources of contaminants which may have
any adverse effect on the health of persons;
"(4) describe a program that contains, as appropriate, techni-
cal assistance, financial assistance, implementation of control
measures, education, training, and demonstration projects to
protect the water supply within wellhead protection areas from
such contaminants;
"(5) include contingency plans for the location and provision
of alternate drinking water supplies for each public water
system in the event of well or wellfield contamination by such
contaminants; and
"(6) include a requirement that consideration be given to all
potential sources of such contaminants within the expected
wellhead area of a new water well which serves a public water
supply system.
"(b) PUBLIC PARTICIPATION.—To the maximum extent possible,
each State shall establish procedures, including but not limited to
the establishment of technical and citizens' advisory committees, to
encourage the public to participate in developing the protection pro-
-------
22
gram for wellhead areas. Such procedures shall include notice and
opportunity for public hearing on the State program before it is sub-
mitted to the Administrator.
"(c) DISAPPROVAL.—
"(1) IN GENERAL.—If, in the judgment of the Administrator, a
State program (or portion thereof, including the definition of a
wellhead protection area), is not adequate to protect public
water systems as required by this section, the Administrator
shall disapprove such program (or portion thereof). A State pro-
gram developed pursuant to subsection (a) shall be deemed to be
adequate unless the Administrator determines, within 9 months
of the receipt of a State program, that such program (or portion
thereof) is inadequate for the purpose of protecting public water
systems as required by this section from contaminants that may
have any adverse effect on the health of persons. If the Admin-
istrator determines that a proposed State program (or any por-
tion thereof) is inadequate, the Administrator shall submit a
written statement of the reasons for such determination to the
Governor of the State.
"(2) MODIFICATION AND RESUBMISSION.—Within 6 months
after receipt of the Administrator's written notice under para-
graph (1) that any proposed State program (or portion thereof) is
inadequate, the Governor or Governor's designee, shall modify
the program based upon the recommendations of the Adminis-
trator and resubmit the modified program to the Administra-
tor
"(d) FEDERAL ASSISTANCE.—After the date 3 years after the enact-
ment of this section, no State shall receive funds authorized to be
appropriated under this section except for the purpose of implement-
ing the program and requirements of paragraphs (4) and (6) of sub-
section (a).
"(e) DEFINITION OF WELLHEAD PROTECTION AREA.—-As used in
this section, the term 'wellhead protection area' means the surface
and subsurface area surrounding a water well or wellfield, supply-
ing a public water system, through which contaminants are reason-
ably likely to move toward and reach such water well or wellfield.
The extent of a wellhead protection area, within a State, necessary
to provide protection from contaminants which may have any ad-
verse effect on the health of persons is to be determined by the State
in the program submitted under subsection (a). Not later than one
year after the enactment of the Safe Drinking Water Act Amend-
ments of 1986, the Administrator shall issue technical guidance
which States may use in making such determinations. Such guid-
ance may reflect such factors as the radius of influence around a
well or wellfield, the depth of drawdown of the water table by such
well or wellfield at any given point, the time or rate of travel of var-
ious contaminants in various hydrologic conditions, distance from
. the well or wellfield, or other factors affecting the likelihood of con-
taminants reaching the well or wellfield, taking into account avail-
able engineering pump tests or comparable data, field, reconnais-
sance, topographic information, and the geology of the formation in
which the well or wellfield is located.
"(f) PROHIBITIONS.—
23
"(1) ACTIVITIES UNDER OTHER LAWS.—No funds authorized to
be appropriated under this section may be used to support ac-
tivities authorized by the Federal Water Pollution Control Act,
the Solid Waste Disposal Act, the Comprehensive Environmen-
tal Response, Compensation, and Liability Act of 1980, or other
sections of this Act.
"(2) INDIVIDUAL SOURCES.—No funds authorized to be appro-
priated under this section may be used to bring individual
sources of contamination into compliance.
"(g) IMPLEMENTATION.—Each State shall make every reasonable
effort to implement the State wellhead area protection program
under this section within 2 years of submitting the program to the
Administrator. Each State shall submit to the Administrator a bi-
ennial status report describing the State's progress in implementing
the program. Such report shall include amendments to the State
program for water wells sited during the biennial period.
' (h) FEDERAL AGENCIES.—Each department, agency, and instru-
mentality of the executive, legislative, and judicial branches of the
Federal Government having jurisdiction over any potential source of
contaminants identified by a State program pursuant to the provi-
sions of subsection (aX3) shall be subject to and comply with all re-
quirements of the State program developed according to subsection
(a)(4) applicable to such potential source of contaminants, both sub-
stantive and procedural, in the same manner, and to the same
extent, as any other person is subject to such requirements, induct-
ing payment of reasonable charges and fees. The President may
exempt any potential source under the jurisdiction of any depart-
ment, agency, or instrumentality in the executive branch if the
President determines it to be in the paramount interest of the
United States to do so. No such exemption shall be granted due to
the lack of an appropriation unless the President shall have specifi-
cally requested such appropriation as part of the budgetary process
and the Congress shall have failed to make available such requested
appropria tions.
(i) ADDITIONAL REQUIREMENT.—
"(1) IN GENERAL.—In addition to the provisions of subsection
(a) of this section, States in which there are more than 2,500
active wells at which annular injection is used as of January 1,
1986, shall include in their State program a certification that a
State program exists and is being adequately enforced that pro-
vides protection from contaminants which may have any ad-
verse effect on the health of persons and which are associated
with the annular injection or surface disposal of brines associ-
ated with oil and gas production.
"(2) DEFINITION.—For purposes of this subsection, the term
'annular injection' means the reinjection of brines associated
with the production of oil or gas between the production and
surface casings of a conventional oil or gas producing well.
"(3) REVIEW.—The Administrator shall conduct a review of
each program certified under this subsection.
"(4) DISAPPROVAL.—// a State fails to include the certifica-
tion required by this subsection or if in the judgment of the Ad-
ministrator the State program certified under this subsection is
not being adequately enforced, the Administrator shall disap-
-------
24
prove the State program submitted under subsection (a) of this
section. ' »• <'• •
"(j) COORDINATION WITH OTHER LAWS.—Nothing in this section
shall authorize or require any department, agency, or other instru-
mentality of the Federal Government or State or local government to
apportion, allocate or otherwise regulate the withdrawal or benefi-
cial use of ground or surface waters, so as to abrogate or modify any
existing rights to water established pursuant to State or Federal
law, including interstate compacts.".
-------
APPENDIX B: SSA Congressional Conference Report
-------
SECTION 203—SOLE SOURCE AQUIFER DEMONSTRATION PROGRAM
Senate bill.— The Senate bill establishes administrative proce-
dures for the development, implementation, and assessment of
demonstration programs designed to protect ground water re-
sources within designated sole source aquifer areas.
The Administrator is required, within 16 months of enactment,
to establish criteria for identifying "critical aquifer protection
areas" within sole source aquifer areas designated under Section
M24(e) of the Act by the date of enactment.
41
Any government or any planning entity that identifies a "critical
aquifer protection area" over which it has authority or jurisdiction
may apply to the Administrator for the selection of such area for a
demonstration program.
The provision establishes specific elements that are to be includ-
ed in such application. The Administrator must approve or disap-
prove the application within 120 days of receipt. Upon approval of
an application, the Administrator may enter into a cooperative
agreement with the applicant to establish a demonstration pro-
gram and may provide, on a matching basis, a grant of 50 per cent
of the costs of developing and implementing the plan.
An annual authorization of $20,000,000 is provided for grants for
fiscal years 1987-1990. The total amount of grants for any designat-
ed sole source aquifer in a fiscal year shalf not exceed $4,000,000.
Each State participating in the program is required to submit a
report to the Administrator no later than December 31, 1989, as-
sessing the impact of the program. No later than September 30,
1990, the Administrator is required to submit a report to Congress
summarizing State reports and assessing the accomplishments of
the sole source aquifer demonstration program.
House amendment.—The House amendment establishes proce-
dures for the development and implementation of a protection pro-
gram for any aquifer designated as a sole or principal source aqui-
fer under section 1424(e) of the Act. Upon designation of a sole or
principal source aquifer, any municipality within the area may ini-
tiate proceedings for the designation of a "special protection area"
within such area by petitioning the Governor to apply to the Ad-
ministrator for such designation. A petition must contain hydrogeo-
logic and other information specified in the provision.
If the Administrator approves- the petition, the Administrator is
authorized to provide to the State, on a matching basis, a grant of
50 percent of the costs incurred in preparing the petition and de-
veloping the plan. After such approval, the planning entity is di-
rected to prepare a comprehensive management plan for the spe-
cial protection area. Plans are required to include thirteen ele-
ments specified in the House bill. The Administrator is authorized
to provide to the State a matching grant of 50 percent of the costs
of implementing the plan (60 percent in the case of an aquifer serv-
inga population of 10,000 or less).
The amendment also prohibits the disposal of solid waste over
the unconsolidated Quarternary aquifer in the Rockaway River
Basin, New Jersey, currently designated as a sole or principal
source aquifer under section 1424(e) of the Act, or the recharge
zone or streamflow source zone of that aquifer.
Conference agreement.—The Conference agreement adopts a pro-
vision combining the House and Senate language with modifica-
tions.
The provision establishes procedures for the development, imple-
mentation, and assessment of demonstration programs designed to
protect critical aquifer protection areas located within areas desig-
nated as sole or principal source aquifers under section 1424(e) of
the Act. A critical aquifer protection area is defined as: (1) all or
part of an area located within an area for which an application or
designation as a sole or principal source aquifer (pursuant to sec-
-------
42
tion 1424(e)) has been submitted and approved by the Administra-
tor not later than 24 months after the date of enactment and
which satisfies the criteria established by the Adminstrator; and (2)
all or part of an area which is within an aquifer designated as a
sole source aquifer, as of the date of enactment of these amend-
ments, and for which an areawide ground water quality protection
plan has been approved under section 208 of the Clean Water Act
prior to such enactment.
Any State, municipal or local government or political subdivision
thereof or any planning entity that identifies a critical aquifer pro-
tection area over which it has authority or jurisdiction may apply
to the Administrator for the selection of such area for a demonstra-
tion program. Applicants, other than the Governor, shall submit an
application jointly with the Governor.
The Administrator is required to establish criteria, not later
than one year from the date of enactment, for identifying "critical
aquifer protection areas." In establishing such criteria, the Admin-
istrator shall consider a number of specified hydrogeologic, econom-
ic, social and environmental factors.
An application submitted to the Administrator by any applicant
is required to: (1) propose boundaries for the critical aquifer protec-
tion area within its jurisdiction; (2) to designate a planning entity
to develop a comprehensive management plan for the critical pro-
tection area; (3) establish procedures for public participation; (4) in-
clude a hydrogeologic assessment of surface and ground water re-
sources within the critical protection area; (5) include a comprehen-
sive management plan for the proposed protection area; and (6) in-
clude the measures and schedule proposed for implementation of
such plan.
The provision specifies elements to be included in a protection
plan, the objective of which should be to maintain the quality of
the ground water in the critical protection area in a manner rea-
sonably expected to protect human health, the environment and
ground water resources. There are a number of additional elements
specified that states may choose to include in a plan to meet this
objective.
Within 120 days after receipt of an application under this sec-
tion, the Administrator must, approve or disapprove the application
based on a determination that the critical protection area satisfies
the established criteria and that a demonstration program for the
area would provide protection for ground water quality consistent
with the stated objectives.
Upon approval of an application, the Administrator may enter
into a cooperative agreement with the applicant to establish a dem-
onstration program and provide to the applicant, on a matching
basis, a grant of 50 per cent of the costs of implementing the plan.
The Administrator may also reimburse the applicant of an ap-
proved plan up to 50 per cent of the costs of developing a plan,
except for plans approved under section 208 of the Clean Water
Act. The total amount of grants under this section for any one aq-
uifer, designated under section 1424(e), shall not exceed $4,000,000
in any one fiscal year.
No funds authorized under this subsection may be used to fund
s funded under other sections of this Act or the Clean
43
Water Act, the Solid Waste Disposal Act, the Comprehensive Envi-
ronmental Response, Compensation and Liability Act of 1980 or
other Federal environmental statutes.
States are required, not later than December 31, 1989, to submit
to the Administrator a report assessing the impact of the program
on ground water quality and identifying those measures found to
be effective in protecting ground water resources. No later than
September 30, 1990, the Administrator is required to submit to
Congress a report summarizing the State reports, and assessing the
accomplishments of the sole source aquifer demonstration program.
The provision establishes that nothing under this section is to be
construed to amend, supersede or abrogate rights to quantities of
water which have been established by interstate water compacts,
Supreme Court decrees, or State water laws; or any requirement
imposed or right provided under any Federal or State environmen-
tal or public health statute.
SECTION 204—EMERGENCY POWERS
Senate bill.—The Senate bill has no provision.
House amendment.—The House amendment provides that if the
Administrator or the delegated State enforcement authority deter-
mines that any person has caused or contributed to the presence of
any contaminant that may adversely effect the health of persons in
any sole or principal source aquifer (designated under section
1424(e)), which supplies or can be expected to supply a public water
system, then either authority may issue an order requiring such
persons to provide adequate supplies of potable drinking water to
the persons served by the public water system. Provisions for judi-
cial review of such orders and civil penalties are also established.
Conference agreement.—The conference agreement changes the
House language to clarify the Administrator s existing authority to"
take such action as deemed necessary upon receipt of information
that a contaminant, which is present m or is likely to enter.a
public water system or underground source of drinking water, may
present an imminent substantial endangerment to the health of
persons and that appropriate State and local action have not been
taken. Such action may include orders requiring the provision of
alternative water supplies by persons who caused or contributed to
the endangerment.
SECTION 205—STATE PROGRAMS TO ESTABLISH WELLHEAD PROTECTION
AREAS
Senate bill.— The Senate bill has no provision.
House amendment.—The House bill requires States to submit to
the Administrator a comprehensive plan to protect current and po-
tential sources of drinking water within three years of the date of
enactment.
Each plan must: (1) specify the agency responsible for imple-
menting the plan; (2) identify each underground source of drinking
water in the State and describe the characteristics of each source;
(3) describe the location and types of human development which
affect each source; (4) set out the regulations and other measures
(including best management practices) for activities that may con-
-------
44
taminate sources; and (5) guarantee or provide for an alternative
drinking water supply when an underground drinking water source
is contaminated.
Each State is to make every reasonable effort to implement the
State plan under this section within two years of its adoption.
Within two years after the approval of each State plan under this
section, each State is to submit to the Administrator a status
report describing the State's progress in implementing the plan.
A State that has not complied with the requirements of this sec-
tion may not receive assistance for its underground injection con-
trol program established under the Act.
Conference agreement.—In a new Section 205, the conference
modifies the House provision and requires each State to submit a
program within three years to protect wellhead areas within its ju-
risdiction from contaminants that may have any adverse effect on
the health of persons. The purpose of such programs is to protect
underground drinking water supplies from such contamination.
Each program must: (1) specify the duties of State and local
agencies and public water systems with respect to the development
and implementation of programs; (2) determine the wellhead pro-
jection area based on all reasonably available hydrogeologic infor-
mation on flow, recharge and discharge and other information the
State deems necessary to adequately determine the area; (3) identi-
fy within each protection area all potential anthropogenic sources
of contaminants which may have any adverse effect on the health
of persons; (4) describe a program that contains, as appropriate,
technical or financial assistance, implementation of control meas-
ures, education, training and demonstration projects to protect the
water supply within wellhead protection areas; (5) include contin-
gency plans for locating and providing alternate drinking water
supplies in the event of contamination of a water supply; and (6)
require consideration of all potential anthropogenic sources of con-
taminants within the expected wellhead area of a new water well.
A 'wellhead protection area is defined as the surface or subsur-
face area, surrounding a water well or wellfield supplying a public
water system, through which contaminants are likely to move
toward.and reach the well or wellfield. The State is to determine
the extent of the wellhead protection area so as to provide protec-
tion from contaminants that may have any adverse effect on the
health of persons.
Within one year of enactment, the Administrator is to provide
technical guidance that the States may use to determine the pro-
tection area: The guidance is to reflect factors affecting the likeli-
hood of. contaminants reaching the well or wellfield.
Each State has the responsibility for defining the wellhead pro-
tection areas within that State as required by the definition in this
section. This section does not, however, limit the existing authority
of States to manage, regulate, protect, or identify groundwater re-
sources. A State may, in its discretion, identify areas of significant
recharge not contiguous to a well or wellfield in defining a well-
head protection area under this section.
With respect to identification of sources of contamination within
the protection area, the term "anthropogenic sources" means those
sources resulting directlv .or indirectly from human activities.
45
Therefore, State inventories of potential sources of contamination
should include those sources that are man-made and contribute pri-
marily man-made contaminants and those sources created by
human activities that result in the concentration and movement of
naturally-occurring contaminants in or toward a well. Specifically,
however, the mere drawing down of water in a well should not be
considered an "anthropogenic source".
Each State has the responsibility of determining how best to de-
scribe a program to protect the water supply within each protec-
tion area in the State. The provision is structured to afford States
maximum flexibility in formulating a protection strategy. A State
is not required to develop a regulatory program unless it chooses to
do so; a program incorporating one or more of the following ele-
ments—technical and financial assistance, education and training,
and demonstration projects—could be determined by a State to
achieve the required protection.
States can be expected to take a wide variety of approaches to
protection of wellhead areas within their jurisdiction, and it is con-
ceivable that each State could develop its own unique approach.
Protection strategies may also vary for different protection areas
within one State. The amendment recognizes that States are best
able to assess specific problems within their jurisdictions, and to*'
develop and implement necessary protection measures. As a result,"
no groundwater classification assigned by the Administrator is to
lessen the level of protection assigned to an aquifer by the State in -
a wellhead protection area.
The Administrator is granted authority to disapprove a State's
program if it does not include one or more of the required enumer-
ated elements and is, therefore, not adequate to protect public'
water systems as required by this section. If after nine months, the
Administrator has not disapproved a program, it will be deemed to-
be approved.
Because of the important State role in protecting groundwater,
the Administrator's disapproval authority should be used judicious-
ly. In the event a program is disapproved, the Administrator must
submit to the Governor a written statement of the reasons for dis-
approval, and the State must modify and resubmit the program
within six months.
The penalty for failure of a State to have an approved program
is that the State will not be eligible for Federal funds to implement
the program, beginning three years after enactment. This is the
only penalty for failure to develop an adequate plan./
Federal agencies having jurisdiction over any potential source of
contaminants identified by a State program must comply with all
applicable requirements of the State program, including payment
of reasonable charges and fees, in the same manner and to the
same extent as any other person. The President may exempt indi-
vidual sources after determining it to be in the paramount interest
of the United States to do so, but no exemption can be made be-
cause of a lack of funds unless the President requested adequate
funds and Congress failed to appropriate them. This provision is
not intended to modify or alter obligations and responsibilities
under other Federal or State laws. Moreover, it cannot operate to
-------
46
waive or limit more stringent requirements established under such
other laws.
An additional requirement of this section applies to any State in
which there are more than 2500 active wells at which annular in-
jection of brines associated with oil or gas production, is used as of
January 1, 1986. Any such State must include in its program a cer-
tification to the Administrator that a State program exists and is
being adequately enforced that provides protection from contami-
nants which may have any adverse effect on the health of persons
and which are associated with the annular injection or surface dis-
posal of brines associated with oil and gas production. The Admin-
istrator's review under this provision is to assure that the required
certification is submitted by the State and to assure, on the basis of
existing information reasonably available to him, that the program
is adequately enforced. Such review should be limited to the ques-
tion of certification and enforcement and will not affect separate
determinations under this Act, such as the granting of primacy to
a State under the UIC program. Brine presents the most signifi-
cant problem in the State of Ohio, which has older oil and gas-pro-
ducing wells. As the product depletes, brine makes up a higher pro-
portion of the fluid pumped and so creates a more pressing disposal
problem. This provision, therefore, is particularly aimed at Ohio,
which has proven to be remiss in its enforcement of brine-related
problems.
The conference substitute clarifies that nothing in this Act au-
thorizes or requires activity by any government entity which would
alter existing water rights or priorities. While not authorizing or
requiring any such government activity, neither does it limit the
existing authority of States to manage, regulate, protect, or identi-
fy groundwater resources within their jurisdiction.
In order to assure that the monies authorized to be appropriated
under this section are directed toward making state groundwater
protection efforts as effective as possible, the conference substitute
states that such funds cannot be used to support activities under
other Federal Acts or other sections of this Act.
-------
APPENDIX C: List of State WHPA Methods References
i
-------
STATE REFERENCE DOCUMENT
MASSACHUSETTS 2. Heath, D.L., "Hydrogeologic Considera-
tions of Zone of Contribution Methods
Used By Cape Cod Planning and Eco-
nomic Development Commission and SEA
Consultants, Inc. for Public Supply
Wells in Barnstable, Massachusetts,"
(Office of Groundwater Protection
U.S. Environmental Protection Agency)
3. Gallagher, T. and Nickerson, S., "The
Cape Cod Aquifer Management Project:
A Multi-Agency Approach to Ground
Water Protection," Proceedings of the
National Water Well Association Third
Annual Eastern Regional Ground-Water
Conference, (1986)
4. Roy, Steven P., and Drake, J.ohn T.,
"Development of the Massachusetts
Ground-Water Monitoring Program,"
p. 145-149
5. Evaluation of Approaches to Determine
Recharge Areas for Public Supply
Wells, Report, (Cape Cod Aquifer
Management Project Aquifer Assessment
Committee, April 1986)
6. Edgartown Water Resource Protection
Program, Final Report, (Anderson-
Nichols & Co., Inc., May 1985)
7. Groundwater Protection Strategy, Report,
(Comonwealth of Massachusetts Depart-
ment of Environmental Quality Engi-
neering Division of Water Supply,
January 1983)
8. Horsley, Scott W. , and Cambareri,
Thomas C., "Delineating Zones of
Contribution for Public Supply Wells
to Protect Ground Water in New
England," Proceedings of the National
Water Well Conference. (Journal
NEWWA, March 1986)
Note: 'Awaiting Delivery
-------
LIST OF REFERENCES
FOR STATES SURVEY OF WHPA METHODS
STATE
REFERENCE DOCUMENT
CONNECTICUT
*1
*2
FLORIDA
ILLINOIS
MASSACHUSETTS
EXPLANATION AND EXAMPLE OF AQUIFER
MAPPING TECHNIQUE
EXPLANATION OF CONNECTICUT'S AQUIFER
CLASSIFICATION SYSTEM
Wellfleld Travel Time Model for Selected
Dade, Broward, and Palm Beach
Counties Florida, Final Report,
9243-110 (Camp Dresser & McKee, Inc.,
August 1982)
The Study of Water Supply and The Selec-
tion of Future Wellfield Sites in
Broward County, Florida, Executive
Summary (James M. Montgomery,
Consulting Engineers, Inc. in associ-
ation with Dames & Moore, June 1986)
Palm Beach County Well Field Protection
Model, Draft Report, (Dames & Moore,
October 1986)
Dade County's Regulatory Approach to
Wellfield Protection, Report, (Metro-
politan Dade County Environmental
Resources Management)
DeHan, R.S., "New Approach to Protection
of Sensitive Aquifers in Florida,"
Department of Environmental Regula-
tion
A Plan For Protecting Illinois Groundj-
water, Conceptual Plan, (Ground-Water
Section, Division of Public Water
Supply)
New England Project Proposal, Demonstra-
tion of the Use of Three-Dimensional
Ground-Water Modeling to Delineate
Zones of Contribution to Public
Supply Wells, Cape Cod. Massachu-
setts , (Northeastern Water Resources
Division, April 1986)
Note: *Awaiting Delivery
-------
STATE
REFERENCE DOCUMENT
MASSACHUSETTS
PENNSYLVANIA
SOUTH CAROLINA
SOUTH DAKOTA
VERMONT
9. Horsley, Scott W., "Delineating Zones of
Contribution for Public Supply Wells
to Protect Groundwater," Proceedings
of the National Water Well Conference
(Journal NEWWA, November 1983)
*10. Cape Cod Planning and Economic Develop-
ment Commission, "Water Supply
Protection Project Report," 1979.
*11. Offer, Stuart A. and Grahame J. Larson,
"Determination of Recharge Rates to a
Drift Aquifer Using Bomb Tritium
Within the Saturated Zone," (Michigan
State University, 1982)
*12. U.S. Department of the Interior Geo-
logical Survey, "Digital Models of
Ground-Water Flow in the Cape Cod
Aquifer System, Massachusetts," Open-
File Report 80-67, (Water Resources
Investigations, 1981)
*13. Grgundwater and Water Resource Pro-
tection Plan for the Town of
Barnstable, Massachusetts, Report,
(SEA Consultants, Inc., 1985)
1. Proposals for the Management of Ground-
Water Quality in Pennsylvania:
Protection and Monitoring, (Division
of Water Quality Bureau of Water
Quality Management, July 1985)
•1. TECHNICAL PAPER(S) DISCUSSING ISOTOPE
AND TRITIUM DATING TECHNIQUES.
•1. PRELIMINARY REPORTS DISCUSSING PROPOSED
METHODOLOGY FOR DELINEATING WELL HEAD
PROTECTION AREAS
1. Vermont Aquifer Protection Area Refer-
ence Document, Aquifer Protection
Areas Prototype Project, (Department
of Water Resources and Environmental
Engineering)
2. "Groundwater Protection," Ground Water
Protection Law. Chapter 48.
Note: *Awaiting Delivery
-------
STATE
REFERENCE DOCUMENT
VERMONT
8
WASHINGTON
Ground-Water Resources of the Rutland
Area, Vermont, Water-Resources
Investigations 82-4057, (U.S. Geo-
logical Survey, 1983)
Ground Water Favorability Map of the
Nulhegan-Passumpsic River Basin,
Vermont, (Vermont Department of
Water Resources and the U.S. Geo-
logical Survey, 1967)
Ground Water Favorability Map of the
Otter Creek Basin, Vermont, (Vermont
Department of Water Resources and the
U.S. Geological Survey, 1967)
Ground Water Favorability Map of the
Lamoille River Basin, Vermont,
Vermont Department of Water Resources
and the U.S.Geological Survey, 1967)
Ground Water Favorability Map of the
Missisquoi River Basin, Vermont,
(Vermont Department of Water
Resources and the U.S. Geological
Survey, 1967)
State of Vermont Ground Water Favora-
ability Map of the Batten Kill.
Walloomsac River and Hoosic River
Basins, (Vermont Department of Water
Resources and the U.S. Geological
Survey, 1966)
Guidelines for Development of Ground
Water Management Areas and Programs,
Chapter 173-100 WAC, (Water Resources
Planning and Management Section
Washington State Department of
Ecology, April 1986)
Note: *Awaiting Delivery
-------
APPENDIX D: Glossary of Hydrogeologic Terminology
-------
GLOSSARY
The purpose of this Glossary is to provide to the Workshop
Participant a list of terms commonly used by hydrogeologists.
The definitions provided in this glossary are not necessarily
endorsed by EPA nor are they to be viewed as suggested language
for regulatory purposes. Numbers in brackets indicate the
reference source.
Adsorption. The assimilation of gas, vapor, or dissolved matter
by the surface of a solid [1]. The attraction and adhesion of a
layer of ions from an aqueous solution to the solid mineral
surfaces with which it is in contact; [2].
Advection. The process by which solutes are transported by the
bulk motion of the flowing ground water [1].
Aeration. The process of bringing air into intimate contact with
water, usually by bubbling air through the water to remove
dissolved gases like carbon dioxide and hydrogen sulfide or to
oxidize dissolved materials like iron compounds [1].
Air stripping. A mass transfer process in which a substance in
solution in water is transferred to solution in a gas, usually
air [1].
Alkaline. Any of various soluble mineral salts found in natural
water and arid soils having a pH greater than 7. In water
analysis, it represents the carbonates, bicarbonates, hydroxides,
and occasionally the borates, silicates, and phosphates in the
water [1].
Alluvial. Pertaining to or composed of alluvium or deposited by
a stream or running water.[1]
Alluvium. A general term for clay, silt, and sand, gravel, or
similar unconsolidated material deposited during comparatively
recent geologic time by a stream or other body of running water
as a sorted or semisorted sediment in the bed of the stream or on
its floodplain or delta, or as a cone or fan at the base of a
mountain slope.[1]
Anisotropic. Having some physical property that varies with
direction.[1]
Anisotropy. The condition under which one or more of the
hydraulic properties of an aquifer vary according to the
direction of flow.[2]
-------
Aquiclude. A saturated, but .poorly permeable bed, formation, or
group of formations that does not yield water freely to a well or
spring. However, an aquiclude may transmit appreciable water to
or from adjacent aquifers.[l]
Aquifer. A formation, group of formations, or part of a
formation that contains sufficient saturated permeable material
to yield economical quantities of water to wells and springs.[1]
Rock or sediment in a formation, group of formations, or part of
a formation which is saturated and sufficiently permeable to
transmit economic quantities of water to wells and springs.[2]
Aquifer, unconfined. An aquifer in which there are no confining
beds between the zone of saturation and the surface. There will
be a water table in an unconfined aquifer. Water-table aquifer is
a synonym.[2]
Aquifer test. A test involving the withdrawal of measured
quantities of water from or addition of water to, a well and the
measurement of resulting changes in head in the aquifer both
during and after the period of discharge or addition.[1]
Aquitard. A geologic formation, group of formations, or part of
a formation through which virtually no water moves.[1]
Artesian well. A well deriving its water from a confined aquifer
in which the water level stands above the ground surface;
synonymous with flowing artesian well.[l]
Artificial recharge. Recharge at a rate greater than natural,
resulting from deliberate actions of man.[1] The process by
which water can be injected or added to an aquifer. Dug basins,
drilled wells, or simply the spread of water across the land
surface are all means of artificial recharge.[2]
Basalt. A general term for dark-colored iron- and magnesium-rich
igneous rocks, commonly extrusive, but locally intrusive. It is
the principal rock type making up the ocean floor.[1]
Baseflow. That part of a stream discharge derived from ground
water seeping into the stream.[2]
Bedrock. A general term for the rock, usually solid, that
underlies soil or other unconsolidated material.[1]
Buried valley. A depression in an ancient land surface or in
bedrock now covered by younger deposits, especially a preglacial
valley filled with glacial drift.[1]
Calibration. Adjustment of the input data until computed heads
match the field values.[3]
-------
Capillary fringe. The zone at the bottom of the vadose zone
where ground water is drawn upward by capillary force.[1] The
zone immediately above the water table, where water is drawn
upward by capillary attraction.[2]
Carbonate. A sediment formed by the organic or inorganic
precipitation from aqueous solution of carbonates of calcium,
magnesium, or iron.[l]
Carbonate rocks. A rock consisting chiefly of carbonate
minerals, such as limestone and dolomite.[1]
Cathode. Any negatively charged electrode, as in an
electrolytes, characteristically moving toward a negative
electrode.[1]
Cation. An ion having a positive charge and, in electrolytes,
characteristically moving toward a negative electrode.[1]
Cation exchange. Ion exchange process in which cations in
solution are exchanged for other cations from an ion
exchanger.[1]
Chlorine. A gas, C12, widely used in the disinfection of water
and as an oxidizing agent.[1]
Clastic. Pertaining to a rock or sediment composed principally
of broken fragments that are derived from pre-existing rocks or
minerals and that have been transported some distance from their
places of origin.[1]
Coefficient of permeability. An obsolete term that has been
replaced by the term hydraulic conductivity.[1]
Coefficient of storage. The volume of water an aquifer releases
from or takes into storage per unit surface area of the aquifer
per unit change in head.[l]
Coefficient of transmissivity. See Transmissivity.[1]
Colloid. Extremely small solid particles, 0.0001 to 1 micron in
size, which will not settle out of a solution; intermediate
between a true dissolved particle and a suspended solid which
will settle out of solution.[1]
Cone of depression. A depression in the ground water-table or
potentiometric surface that has the shape of an inverted cone and
develops around a well from which water is being withdrawn. It
defines the area of influence of a well. [1]
-------
Confined aquifer. A formation in which the ground water is
isolated from the atmosphere at the point of discharge by
impermeable geologic formations; confined ground water is
generally subject to pressure greater than atmospheric.[1]
Confining bed. A body of material of low hydraulic conductivity
that is stratigraphically adjacent to one or more aquifers. It
may lie above or below the aquifer.[2]
Contamination. The degradation of natural water quality as a
result of man's activities. There is no implication of any
specific limits, since the degree of permissible contamination
depends upon the intended end use, or uses, of the water.[1]
Darcy's law. A derived equation for the flow of fluids on the
assumption that the flow is laminar and that inertia can be
neglected.[1]
Density. Matter measured as mass per unit volume expressed in
pounds per gallon (lb/gal). pounds per cubic ft (lb/ft3), and
kilogram per cubic m (kg/nr).[l] The mass of quantity of a
substance per unit volume. Units are kilograms per cubic meter
or grams per cubic centimeter.[2]
Diagenesis. The chemical and physical changes occurring in
sediments before consolidation or while in the environment of
deposition.[2]
Digital computer model. A model of ground-water flow in which
the aquifer is described by numerical equations with specified
values for boundary conditions which are solved on a digital
computer.[2]
Direct precipitation. Water that falls directly into a lake or
stream without passing through any land phase of the runoff
cycle.[2]
Discharge area. An area in which there are upward components of
hydraulic heat in the aquifer. Ground water is flowing toward
the surface in a discharge area and may escape as a spring, seep,
or aseflow, or by evaporation and transpiration.[2]
Discharge velocity. An apparent velocity, calculated for Darcy's
law, which represents the flow rate at which water would move
through an aquifer if the aquifer were an open conduit. Also
called specific discharge.[2]
Dispersion. The spreading and mixing of chemical constituents in
ground water caused by diffusion and mixing due to microscopic
variations in velocities within and between pores.[1]
-------
Drainage basin. The land area from which surface runoff drains
into a stream system.[2]
Drawdown. The distance between the static water level and the
surface of the cone of depression.[1] A lowering of the water
table of an unconfined aquifer or the potentiometric surface of a
confined aquifer caused by pumping of ground water from wells.[2]
Dynamic equilibrium. A condition of which the amount of recharge
to an aquifer equals the amount of natural discharge.[2]
Effective porosity. The amount of interconnected pore space
through which fluids can pass, expressed as a percent of bulk
volume. Part of the total porosity will be occupied by static
fluid being held to the mineral surface by surface tension, so
effective porosity will be less than total porosity.[2]
Equipotential line. A contour line on the water table or
potentiometric surface; a line along which the pressure head of
ground water in an aquifer is the same. Fluid flow is normal to
these lines in the direction of decreasing fluid potential.[1] A
line in a two-dimensional ground-water flow field such that the
total hydraulic head is the same for all points along the
line.[2]
Equipotential surface. A surface in a three-dimensional ground-
water flow field such that the total hydraulic head is the same
everywhere on the surface.[2]
Evapotranspiration. Loss of water from a land area through
transpiration of plants and evaporation from the soil.[l] The
sum of evaporation plus transpiration.[2]
Evapotranspiration, actual. The evaporation that actually occurs
under given climatic and soil-moisture conditions.[2]
Evapotranspiration, potential. The evapotranspiration that would
occur under given climatic conditions if there were unlimited
soil moisture.[2]
Flow lines. Lines indicating the direction followed by ground
water toward points of discharge. Flow line are perpendicular to
equipotential lines.[1]
Flow Model. A digital computer model that calculates a hydraulic
head field for the modeling domain using numerical methods to
arrive at an approximate solution to the differential equation of
ground-water flow.[3]
Glacial drift. A general term for unconsolidated sediment
transported by glaciers and deposited directly or land or in the
sea.[1]
-------
Ground water. The water contained in interconnected pores
located below the water table in an unconfined aquifer or located
in a confined aquifer.[2]
Ground-water basin. A rather vague designation pertaining to a
ground-water reservoir which is more or less separate from
neighboring ground-water reservoirs. A ground-water basin could
be separated from adjacent basins by geologic boundaries or by
hydrologic boundaries.[2]
Ground-water, confined. The water contained in a confined
aquifer. Pore-water pressure is grater than atmosphere at the
top of the confined aquifer.[2]
Ground-water flow. The movement of water through opening in
sediment and rock which occurs in the zone of saturation.
Ground-water, perched. The water in an isolated, saturated zone
located in the zone of aeration. It is the result of the
presence of a layer of material of low hydraulic conductivity,
called a perching bed. Perched ground water will have a perched
water table.[2]
Ground-water table. The surface between the zone of saturation
and the zone of aeration; the surface of an unconfined
aquifer.[1]
Ground-water, unconfined. The water in an aquifer where there is
a water table.[2]
Hydraulic conductivity. The rate of flow of water in gallons per
day through a cross section of one square foot under a unit
hydraulic gradient, at the prevailing temperature (gpd/ft2). In
the SI System, the units are m3/day/m2 or m/day.[l] A
coefficient of proportionality describing the rate at which water
can move through a permeable medium. The density and kinematic
viscosity of the water must be considered in determining
hydraulic conductivity.[2] Hydraulic Conductivity (K) is a
measure of the capacity of a porous medium to transmit water. It
is governed by the size and shape of the pores, the effectiveness
of the interconnection between pores,and the physical properties
of the fluid.[3]
Hydraulic gradient. The rate of change in total head per unit of
distance of flow in a given•direction.[1] The change in total
head with a change in distance in a given direction. The
direction is that which yield a maximum rate of decrease in
head.[2] The difference in hydraulic heads (h^ - h2), divided by
the distance (L) along the flowpath.[3]
i = (hx - h2) / L
-------
Hydrodynamic dispersion. The process by which ground water
containing a solute is diluted with uncontaminated ground water
as it moves through an aquifer.[2]
Hydrogeologic. Those factors that deal with subsurface waters
and related geologic aspects of surface waters.[1]
Igneous rocks. Rocks that solidified from molten or partly
molten materials, that is, from a magma.[1]
Infiltration. The flow of water downward from the land surface
into and through the upper soil layers.[2]
Interference. The condition occurring when the area of influence-
of a water well comes into contact with or overlaps that of a
neighboring well, as when two wells are pumping from the same
aquifer or are located near each other.[1]
Intrinsic permeability. Pertaining to the relative ease with
which a porous medium can transmit a liquid under a hydraulic or
potential gradient. It is a property of the porous medium and is
independent of the nature of the liquid or the potential
field.[2]
Ion. Any element or compound that has gained or lost an
electron, so that it is no longer neutral electrically, but
carries a charge.[1]
Isotropic. Said of a medium whose properties are the same in all
directions.[1]
Isotropy. The condition in which hydraulic properties of the
aquifer are equal in all directions.[2]
Karst topography. A type of topography that is formed on
limestone, gypsum, and other rocks by dissolution, and is
characterized by sinkholes, caves, and underground drainage.[1]
Kinematic viscosity. The ratio of dynamic viscosity to mass
density. It is obtained by dividing dynamic viscosity by the
fluid density. Units of kinematic viscosity are square meters pr
second.[2]
Laminar flow. Water flow in which the stream lines remain
distinct and in which the flow direction at every point remains
unchanged with time. It is characteristic of the movement of
ground water.[1] That type of flow in which the fluid particles
follow paths that are smooth, straight, and parallel to the
channel walls. In laminar flow, the viscosity of the fluid damps
out turbulent motion. Compare with Turbulent flow.[2]
-------
Leachate. The liquid that has percolated through solid waste and
dissolved soluble components.[1]
Leaky confining layer. A low-permeability layer that can
transmit water at sufficient rates to furnish some recharge to a
well pumping from an underlying aquifer. Also called
aquitard.[2]
Limestone. A sedimentary rock consisting chiefly of calcium
carbonate, primarily in the form of the mineral calcite.[1]
Metamorphic rocks. Any rock derived from pre-existing rocks by
mineralogical, chemical, and/or structural changes, essentially
in the solid state, in response to marked changes in temperature,
pressure, shearing stress, and chemical environment, generally at
depth in the Earth's crust.[1]
Molecular diffusion. Dispersion of a chemical caused by the
kinetic activity of the ionic or molecular constituents.[1]
Molecule. A stable configuration of atomic nuclei and electrons
bound together by electrostatic and electromagnetic forces. It
is the simplest structural unit that displays the characteristic
physical and chemical properties of a compound.[1]
Moraine. A mound, ridge, or other distinct accumulation of
unsorted, unstratified glacial drift, predominantly till,
deposited chiefly by direct action of glacier ice.[1]
Naturally developed well. A well in which the screen is placed
in direct contact with the aquifer materials; no filter pack is
used.[1]
Observation well. A well drilled in a selected location for the
purpose of observing parameters such as water levels and pressure
changes.[1] A nonpumping well used to observe the elevation of
the water table or the potentiometric surface. An observation
well is generally of larger diameter than a piezometer and
typically is screened or slotted throughout the thickness of the
aquifer.[2]
Outwash. Stratified sand and gravel removed or washed out from a
glacier by meltwater streams and deposited in front of or beyond
the end moraine or the margin of an active glacier. The coarser
material is deposited nearer to the ice.[l]
Outwash plain. A broad, gently sloping sheet of outwash.[l]
Overburden. The loose soil, silt, sand gravel, or other
unconsolidated material overlying bedrock, either transported or
formed in place; regolith.[1]
8
-------
Partial penetration. When the intake portion of the well is less
than the full thickness of the aquifer.[1]
Perched water. Unconfined ground water separated from an
underlying main body of ground water by an unsaturated zone.[1]
Percolate. The act of water seeping or filtering through the
soil without a definite channel.[1]
Permeability. The property or capacity of a porous rock,
sediment, or soil for transmitting a fluid; it is a measure of
the relative ease of fluid flow under unequal pressure.[1]
pH. A measure of the acidity of alkalinity of a solution,
numerically equal to 7 for neutral solutions, increasing with
increasing alkalinity and decreasing with increasing acidity.
Originally stood for the words potential of hydrogen.[1]
Piezometer. A nonpumping well, generally of small diameter,
which is used to measure the elevation of the water table or
potentiometric surface. A piezometer generally has a short well
screen through which water can enter.[2]
Piezometer nest. A set of two or more piezometers set close to
each other but screened to different depths.[2]
Pollutant. Any solute or cause of change in physical properties
which renders water unfit for a given use.[2]
Pollution. When the contamination concentration levels restrict
the potential use of ground water.[1]
Porosity. The percentage of the bulk volume of a rock or soil
that is occupied by interstices, whether isolated or
connected.[1] The ratio of the volume of void spaces in a rock
or sediment to the total volume of the rock or sediment.[2]
Potentiometric surface. An imaginary surface representing the
total head of ground water in a confined aquifer that is defined
by the level to which water will rise in a well.[l] A surface
that represents the level to which water will rise in tightly
cased wells. If the head varies significantly with depth in the
aquifer, then there may be more than one potentiometric surface.
The water table is a particular potentiometric surface for an
unconfined aquifer.[2]
PUmping cone. The area around a discharging well where the
hydraulic head in the aquifer has been lowered by pumping. Also
called cone of depression.[2]
-------
Pumping test. A test that is conducted to determine aquifer or
well characteristics.[1] A test made by pumping a well for a
period of time and observing the change in hydraulic head in the
aquifer. A pumping test may be used to determine the capacity of
the well and the hydraulic characteristics of the aquifer. Also
called aquifer test.[2]
Radial flow. The flow of water in an aquifer toward a vertically
oriented well.[2]
Radius of influence. The radial distance from the center of a
well bore to the point where there is no lowering of the water
table or potentiometric surface (the edge of its cone of
depression).[1]
Recharge. The addition of water to the zone of saturation; also,
the amount of water added.[1]
Recharge area. An area in which there are downward components of
hydraulic head in the aquifer. Infiltration moves downward into
the deeper parts of an aquifer in a recharge area.[2]
Recharge basin. A basin or pit excavated to provide a means of
allowing water to soak into the ground at rates exceeding those
that would occur naturally.[2]
Recharge boundary. An aquifer system boundary that adds water to
the aquifer. Streams and lakes are typical recharge
boundaries.[2]
Runoff. That part of precipitation flowing to surface streams.[1]
The total amount of water flowing in a stream. It includes
overland flow, return flow, interflow, and baseflow.[2]
Safe yield. The amount of naturally occurring ground water which
can be economically and legally withdrawn from an aquifer on a
sustained basis without impairing the native ground-water quality
or creating an undesirable effect such a environmental damage.
It cannot exceed the increase in recharge or leakage from
adjacent strata plus the reduction in discharge, which is due to
the decline in head caused by pumping.[2]
Saline-water encroachment. The movement, as a result of human
activity, of saline ground water into an aquifer formerly
occupied by fresh water. Passive saline-water encroachment
occurs at a slow rate due to a general lowering of the freshwater
potentiometric surface. Active saline-water encroachment
proceeds at a more rapid rate due to the lowering of the
freshwater potentiometric surface below sea level.[2]
Sandstone. A sedimentary rock composed of abundant rounded or
angular fragments of sand set in a fine-grained matrix (silt or
10
-------
clay) and more or less firmly united by a cementing material.[1]
Saturated zone. The zone in which the voids in the rock or soil
are filled with water at a pressure greater than atmospheric.
The water table is the top of the saturated zone in an unconfined
aquifer.[2]
Sedimentary rocks. Rocks resulting from the consolidation of
loose sediment that has accumulated in layers.[1]
Seepage velocity. The actual rate of movement of fluid particles
through porous media.[2]
Shale. A fine-grained sedimentary rock, formed by the
consolidation of clay, silt, or mud. It is characterized by
finely laminated structure and is sufficiently indurated so that
it will not fall apart on wetting.[1]
Solute Transport Model. Mathematical model used to predict the
movement of particles in the aquifer through time.[3]
Specific capacity. The rate of discharge of a water well per
unit of drawdown, commonly expressed in gpm/ft or m/day/m. It
varies with duration of discharge.[1]
Specific yield. The ratio of the volume of water that a given
mass of saturated rock or soil will yield by gravity to the
volume of that mass. This ratio is stated as a percentage.[1]
Stagnation point. A place in a ground-water flow field at which
the ground water is not moving. The magnitude of vectors of
hydraulic head at the point are equal but opposite in
direction.[2]
Static water level. The level of water in a well that is not
being affected by withdrawal of ground water.[1]
Storage specific. The amount of water released from or taken
into storage per unit volume of a porous medium per unit change
in head..[2]
Storativity. The volume of water an aquifer releases from or
takes into storage per unit surface area of the aquifer per unit
change in head. It-is equal to the product of specific storage
and aquifer thickness. In an unconfined aquifer, the storativity
is equivalent to the specific yield. Also called storage
coefficient.[2]
Stream, gaining. A stream or reach of a stream, the flow of
which is being increased by inflow of ground water. Also known
as an effluent stream.[2]
11
-------
Stream, losing. A stream or reach of a stream that is losing
water by seepage into the ground. Also known as an influent
stream.[2]
Total dissolved solids, TDS. A term that expresses the quantity
of dissolved material in a sample of water, either the residue on
evaporation, dried at 356°F (180°C), or, for many waters that
contain more than about 1,000 mg/1, the sum of the chemical
constituents.[1]
Transmissivity. The rate at which water is transmitted through a
unit width of an aquifer under a unit hydraulic gradient.
Transmissivity values are given in gallons per minute through a
vertical section of an aquifer one foot wide and extending the
full saturated height of an aquifer under a hydraulic gradient of
1 in the English Engineering system; in the International System,
transmissivity is given in cubic meters per day through a
vertical s.ection of an aquifer one meter wide and extending the
full saturated height of an aquifer under a hydraulic gradient of
1.[1] The rate at which water of a prevailing density and
viscosity is transmitted through a unit width of an aquifer or
confining bed under a unit hydraulic gradient. It is a function
of properties of the liquid, the porous media, and the thickness
of the porous media.[2]
Transpiration. The process by which water absorbed by plants,
usually through the roots, is evaporated into the atmosphere from
the plant surface.[1] The process by which plants give off water
vapor through their leaves.[2]
Turbulent flow. Water flow in which the flow lines are confused
and heterogeneously mixed. It is typical of flow in surface-
water bodies.[1] That type of flow in which the fluid .particles
move along very irregular paths. Momentum can be exchanged
between one portion of the fluid and another. Compare with
Laminar flow.[2]
Unconfined aquifer. An aquifer where the water table is exposed
to the atmosphere through openings in the overlying materials.[1]
Unsaturated zone. The zone between the land surface and the
water table. It includes the root zone, intermediate zone, and
capillary fringe. The pore spaces contain water at less than
atmospheric pressure, as well as air and other gases. Saturated
bodies, such as perched ground water, may exist in the
unsaturated zone.[2]
Vadoze zone. The zone containing water under pressure less than
that of the atmosphere, including soil water, intermediate vadose
water, and capillary water. This zone is limited above by the
land surface and below by the surface of the zone of saturation,
that is, the water table.[1]
12
-------
Viscosity. The property of a substance to offer internal
resistance to flow. Specifically, the ratio of the shear stress
to the rate of shear strain.[1] The property of a fluid
describing its resistance to flow. Units of viscosity are
newton-seconds per meter squared or pascal-seconds. Viscosity is
also known as dynamic viscosity.[2]
Water budget. An evaluation of all the sources of supply and the
corresponding discharges with respect to an aquifer or a drainage
basin.[2]
Water table. The surface between the vadose zone and the ground
water; that surface of a body of unconfined ground water at which
the pressure is equal to that of the atmosphere.[1] The surface
in an unconfined aquifer or confining bed at which the pore water
pressure is atmospheric. It can be measured by installing
shallow wells extending a few feet into the zone of saturation
and then measuring the water level in those wells.[2]
Well, fully penetrating. A well drilled to the bottom of an
aquifer, constructed in such a way that it withdraws water from
the entire thickness of the aquifer.[2]
Well interference. The result of two or more pumping wells, the
drawdown cones of which intercept. At a given location, the
total well interference is the sum of the drawdowns due to each
individual well.[2]
Well, partially penetrating. A well constructed in such a way
that it draws water directly from a fractional part of the total
thickness of the aquifer. The fractional part may be located at
the top or the bottom or anywhere in between the aquifer.[2]
Well point. A screening device, equipped with a point on one
end, that is meant to be driven into the ground.[1]
Well screen. A filtering device used to keep sediment from
entering a water well.[l]
Well yield. The volume of water discharged from a well in
gallons per minute or cubic meters per day.[1]
13
-------
GLOSSARY REFERENCES
[1] Driscoll, F.G. 1986
Groundwater and Wells. Second Edition,
Johnson Division, St. Paul, Minnesota. 1089
P-
[2] Fetter, C.W., 1980
Applied Hydrocreology. Charles E. Merrill
Publishing Company, Columbus, OH 488 p.
14
------- |