Conference
Proceedings
Protecting Ground
Water From The
Bottom Up:
Local Responses To
Wellhead Protection
Sponsored By
Reqion '
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Conference
Proceedings
Protecting Ground
Water From The
Bottom Up:
Local Responses To
Wellhead Protection
Sponsored By
&EPA
Region 1
UNDERGROUND INJECTION
PRACTICES COUNCIL
RESEARCH FOUNDATION / : 111 i^BSSS Association
New England
Water Works
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Protecting Ground Water £rjim the Bottom Up:
Local Responses to Wellhead Protection
Sponsored By
The Environmental Protection Agency Region I
Underground Injection Practices Council Research Foundation
New England Water Works Association
Ground water is America's silent, hidden source of drinking
water. It lies in vast stores below ground, flowing softly
through bedrock and unconsolidated deposits of sand and
gravel. Ground water is an essential component of the
nation's ground water supply, and is critical to our economic
growth, national agricultural productivity and the overall
quality of life.
In New England, ground water Is a particularly precious
resource. As a whole, more than 50^ of the region's drinking
water comes from underground sources, whereas residents in
rural areas are nearly 100% dependent. But this important
resource is threatened - in recent years, hundreds of water
supply wells in New England have been shut down due to
contamination.
Although there are numerous federal and state regulations
that prevent contaminants from entering the ground, much of
the power to protect water supplies rests at the local level,
with land use planners and local regulators responsible for
future land use development within the resources and the
tools which can be used to protect them.
This ground water conference is designed to share experiences
gained both nationally and regionally, and to develop a
better understanding of the technical and regulatory
interrelationships involved in protecting New England's
ground water resources, now and for the future.
October 2-3, 1989
Danvers, Massachusetts
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TABLE OF CONTENTS
PAGE #
1. Agenda (i)
2. The Wellhead Protection Program: A National and 1
Regional Overview - Steven Roy
3. Developing and Passing State-wide Aquifer Protection 3
Programs Connecticut: A Case Study - Eric Brown
4. Walpole Board o£ Health: Ground Water Protection 31
Program Implementation - Robin Chappell
5. Case Study of Regional Effort: Wellhead Delineation 37
as a Tool for Fostering Regional Cooperation -
Marilyn Cohen,, Timothy Brown
6. Model for Rural Communities to Assess Threats to 53
Their Ground Water Quality - Lynn Rubinstein
7. The Fox(borough) Guarding the Aquifer Coop: Local 71
Control at Work - Kimberly Noake
8. Ground Water Protection Evolution: Acton's 103
Experience - Duncan Wood, Ronald Bartl
9. Easton's Experience and the Canoe River Aquifer 105
Advisory Committee - Wayne Southworth
10. Wellhead Protection for Public Drinking Water Wells 109
in N. Windham, Maine - D_ajaa_ Perkins
11. Bridgeport Hydraulic Co. Aquifer Protection Plan - 111
Mark Johnson
12. Aquifer Protection Through Large-Scale Computer 119
Modeling, Westfield, Massachussetts - David Edson
13. Determining the Area of Contribution to a Wellfield: 123
A Case Study and Methodology for Wellhead Protection
- James Griswold. Jack Donohue
14. The Use of Time of Travel in Zone of Contribution 137
Delineation and Aquifer Contamination Warning -
James Hal 1
15. Ground Water Modeling and Particle Tracking 145
Analysis of Recharge Areas to Public Water Supply
Wells in Stratified Drift Aquifers - Paul Barlow
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PAGE #
16. Development of Aquifer Protection Zones and 167
Evaluation of Contamination Potential in the Town
of Chelmsford, Massachussetts Water Supply Well -
Donald W. Podsen. Charles Myette
17. Determining the Development Potential Within 183
Wellhead Protection Areas and Resulting Impacts
from Nitrogen Loading - Scott Hnraleyr Jon Witten,
Mark Wilson
18. Evaluation o£ Local Regulatory Efforts in 191
Identifying and Controlling the Threat of
Underground Fuel Storage Tanks - Charlotte Stiefel,
George Heufelder
19. Federal-Local Partnerships for Implementing the 213
Class V Program: Two Case Studies - John Malleck,
Susan Osofsky
20. The UIC Class IV-V Well Survey in Maine, a Multi- 215
Faceted Approach to Inventory, Assessment and
Compliance - Mary Rudd James, Tony Pisanelli
21. Planning Techniques for Estimating Ground Water 237
Impacts of On-Site Systems - Carol Lurie, Elizabeth
Beardsley
22. Road Salting Impacts in Massachussetts - James 255
Barrett, Matthew Dillis
23. Creation of Ground Water Protection Programs: A 257
EPA/Local Partnership at Work - Stuart Kerzner
24. A Computerized Data Management System for Wellfield 271
Protection - Thomas Jenkins,. Guy Jameson
25. Ground Water Resource Based Mapping: Nashua 287
Regional Planning Area, New Hampshire - David Delaney
26. A Model Community Program for Private Wells - Roy 293
Jeffrey, Karen Filchak
27. Board of Health Protection for Private Wells and 303
Ground Waters - Marcle Benes (this paper was
presented by William Domey on behalf of Ms. Benes)
28. Private Well Protection in Coastal Sand and Gravel 309
Aquifers - William Kerfoot
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PROTECTING QRQUND WATER FROM THE
BOTTOM UP« LOCAL RESPONSES TO
WELLHEAD PROTECTION
The Sheraton-Tar a Hotel, Danvers, Massachusetts
October 2-3, 3.989
AGENDA
SUNDAY, Qsisb.gr. I
6:00 - 7:30 Hospitality
MONDAY, October £
8 : 00 - 8:45 Speaker s / Mod er at or Br ea k fast
8 : 00 - 9 : 00 Reg i st r at i on
9 : 0 0 — 9:2 0 Open i n g R e m a r k s 2
Paul Roberts, President, UIPC Research Foundation
Raymond Raposa, Executive Director, NtlWWA
David A. Fierra, Director, Water Management Division, EPA
SESSION I ~ Setting t he Stage for. Ground Water Pro.tl.llil.ojl Programs
Moderator - Jerome J. Hssaley^ Chief, Ground Water Management and
Water Supply Branch, U.S. EPA Region I
9: 2O — 9:40 The Wellhead Protection Programs A National and
Regional Overview - STEVEN ROY, Office of Ground
W a t e r P r o t e c t i o n , LJ . S „ E! F' A H e a d q LA a r t e r' s
9: 40 - 10:00 Developing and Passing State- wide Aquifer Protection
Programs Connecticut!! A Case Study - ERIC BROWN,
M u. r t h a. , C u 1 1 i n a , R i c h t e r ?< P i n n e y
1 0 : 0 0 - 1 0 : 2. 0 W a 1 p o 1 e B o a r d o f H e a 1 1 h s G r o u n d W a t e r P r o t e c t i o n
Program Implementation - ROBIN CHAPPELL, Walpole
Board of Health
10:20 ••- 10:30 Discussion
10:30 - 10:45
SESSION II - Cr ea^t i_n_g RecLi.OQ.aL arid. L2£.§.L til.J2.yjld. Water.. Pr.og.rams
Moderator - Robert E. Mondoxa, Chief, Ground Water Management
S e •:: t i o n , U.S. E F1 A R e g i o n I
1 0 : 4 5 - 1 1 : 0 5 C a s e S t u d y o f R e g i o n a 1 E f f o r t s We? 1 1 h e a d D e 1 i n e a t i o n
as a Tool for Fostering Regional Cooperation —
MARILYN COHEN, North Kingstown Planning Department,
Timothy Brown, Kent County Water Authority
(i ')
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11:05 - 11:25 Model for Rural Communities to Assess Threats to
Their Ground Water Quality - LYNN RUBINSTEIN,
Franklin County Planning Department
11:25 - 11:45 The FoxCborouqh) Suardinq the Aquifer Coops Local
Control at Work - KIMBERLY NQAKE, SEA Consultants
11:45 - 12:15 Ground Water Protection Evolutions Acton's Experience
- DUNCAN WOOD, Goldberg-Zed no & Assoc., Ronald Bartl,
Acton Town Planner
12: 15 - 12:30 DifflCUlBtttiOn
12:30 - Is 45 Lunch on Own
SESSION III - Water Ut i 1 i t i es' Experience i,n, Gr oun.d Water Protection
Moderator ~ Savos D«no«, Superintendent, Littleton Water Department
1:45 - 2:05 Easton's Experience and the Canoe River Aquifer-
Advisory Committee - WAYNE SOUTHWORTH, Easton Water
Department
2:05 ~ 2:20 Wellhead Protection for Public Drinking Water Wells in
N. Windham, Maine - DANA PERKINS, Portland Water
District
2s 20 •- 2:40 Bridgeport Hydraulic Co. Aquifer Protection Plan -
MARK JOHNSON, Bridgeport Hydraulic Company
2:40 - 3:00 Aquifer Protection Through Large-Scale Computer
Modeling, West field, Massachusetts - DAVID EDSON,
D LI f r e s n e—H e n r y C o m p a n y
3:00 - 3:15 Dins CUM ion
3:15 -- 3: 30
SESSION IV - Delineation of Recharge Areas to. Water Supply We 1,1s,
Moderator - Michael Frimpter, Chief, Water Resources Division, U.S.
Geological Survey, Boston, Massachusetts
3:30 •-• 3:50 Determining the Area of Contribution to a Well field:
A Case Study and Methodology for Wellhead Protection -
JAMES QRISWOLD, Jack Donohue, BCI Seonetics
3:50 - 4:10 The Use of Time of Travel in Zone of Contribution
Delineation and Aquifer Contamination Warning -•- JAMES
HALL, U.S. Geological Survey
4:10 4:30 Ground Water Modeling and Particle Tracking Analysis
of Recharge Areas to Public Water Supply Wells in
Stratified Drift Aquifers ~ PAUL BARLOW, U.S.
Geological Survey
Cii >
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4:30 - 4:45 Di»eu*«ion
4:45 p.m. Session Adjournment
GROUND WATER PROTECTION VIDEO SESSION
7s30 p.m. A selection of videotapes on ground water protection
will be shown at this time
1 • " The Power to Protect a TJie Local Role in. ground Water
Protect ion " . 1989. A 25 minute documentary about four communities
which have gone through the process of developing ground water
protection programs. This program, which is sponsored by U.S. EPA.,
Massachusetts Audubon Society, New England Water Works Association,
and others, will be unveiled at this time.
2. "Your W«t«?r , Your Li fa". 1988. A 30 minute program on the
importance of community awareness in ground water protection.
Produced by the Public Interest Video Network, Washington, D.C.
3. "The CI ean Water Gam®" . 1989. A 10 minute video describing the
importance of developing a state clean water strategy. Produced by
the New England Interstate Water Pollution Control Commission,
Boston .
4. "Leaking Underground Storage Tanks. . .Little Time Bombm Ticking":
1987. A 25 minute program about the LUST problem, by the
Connecticut Department of Environmental Protection, Hartford.
5- "The Planning Pro.ce, tiff for Local Ground Water Protection"- 1988.
This 25 minute video describes the process used by the? community of
La Moine, Maine to develop a ground water protection program.
Produced by the Maine State Planning Office.
SESSION I ~ Con t ami nant Source Inventory and Risk A s s e s s m e ri t
Moderator - David Edson, P.E., Def resne-Heriry, Inc.
8:30 — 8:50 Role of Local Gover rimentsi n Implementing a Class V —
Underground Injection Control Program •-• FRANCOISE
BRASIER, Chief, UIC Branch, Office of Drinking Water,
EPA Headquarters, Washington, DC
8:50 - 9:10 Development of Aquifer Protection Zones and Evaluation
of Contamination Potential in the Town of Chelmsford,
Massachusetts Water Supply Wells - DONALD W. PODSEN,
Charles Myette, Wehran Engineering
9:10 - 9:30 Determining the Development Potential Within Wellhead
Protection Areas and Resulting Impacts from Nitrogen
Loading •-•• SCOTT HORSLEY, Jon Witten, Mark Wilson,
H o r s 1 e y Witt e n H e g e m a n n , Inc.
( i i i )
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9:30 - 9:50 Evaluation of Local Regulatory Efforts in Identifying
and Controlling the Threat of Underground Fuel Storage
Tanks - CHARLOTTE 8TIEFEL, George Heufelder,
Barnstable County Health Department
9:50 - 10:05 DiflCUWliion
10:05 - 10:20 Break
SESSION II - Contaminant Source Inventory, and Risk. Assessment
Cont i lined
Moderator - Jeffrey S. Lynn, UIPC, Technical Director
10:20 ~- 1O:40 Federal-Local Partnerships for Implementing the Class
V Program: Two Case Studies -- JOHN MALLECK, Susan
Osofsky, U.S. EPA, Region II
10:40 -- lls 00 The UIC Class IV-V Well Survey in Maine, a Multi-
Faceted Approach to Inventory, Assessment, and
Compliance - MARY RUDD JAMES, Maine Department of
Environmental Protection, Tony Pisanelli, U.S. EPA
Region I
11:00 - 11s20 Planning Techniques for Estimating Ground Water
Impacts"of Gn-Site Systems - CAROL LURIE, ELIZABETH
BEARDSLEY, Camp Dresser ?< McKee, Inc.
11:20 - 11:40 Road Salting Impacts in Massachusetts - JAMES
BARRETT, Matthew Dill is, Mormandeau Engineering
11:40 - 11:55 D i sc uss i on
11:55 •••- 1: 15 Lunch
SESSION III - GejDgjraj2.hJcja_l Illfj^ODJliiGIl Systems and Data Man.aqe.ment
111 Ground Water_ Programs
Moderator - Gregory P. Charest, GIS Coordinator, Information
Man ag ement Br anch, U.S. EPA Reg ion I
1:15 - 1:35 Creation of Ground Water Protection Programs: A EPA/
Local Partnership at Work - STUART KERZNER, U.S. EPA
Region III
1 s35 -1:55 A C omp u teri zed Da t a M an a g em en t System for We11f i e1d
Protection - THOMAS JENKINS, Guy Jamesson, Malcolm
Pirnie, Inc.
1:55 - 2:15 Ground Water Resource Based Mapping; Nashua Regional
Planning Area, Mew Hampshire - DAVID DELANEY, u".S. EPA
Region I
2:15 - 2:30 Discussion
2:30 -•- 2:45 Break
C i v)
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SESSION IV ~ Ground Water Protection and. Private Wei Is
Moderator ~ Michael Rapacx, Program Manager, Division of Water-
Sup p 1 y y Mas s a c h u s e 11 s D e p a r t m e n t o f E n v :i. r o n m e n t a 1
Quali ty
2s 45 - 3:O5 A Model Community Program for Private Wells •-•• ROY
JEFFREY, Karen Filchak, University of Connecticut-
Cooper at i ve Ex t en si on
3:05 -- 3:25 Board of Health Protection for Private Wells and
Ground Waters - WILLIAM DOMEY, P.E., Marcia Benes,
Massachusetts Association of Health Board
3:25 ~ 3:45 Private Well Protection in Coastal Sand and Gravel
Aquifers - WILLIAM KERFOQT, K-V Associates, Inc.
3:45 - 4:05 Massachusetts Private Well Guidelines - CYNTHIA
TOMLINSON, Massachusetts Department of Environmental
Quali ty
4:05 - 4:20 Discussion
4:20 - 4:30 Wrapup and Adjourn
Cv)
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THE WELLHEAD PROTECTION PROGRAM -
NATIONAL OVERVIEW
Steven Roy, US. EPA,
Office of Ground-water Protection
Washington, D.C. 20460
The 1986 Amendments to the Safe Drinking Water
Act (SDWA) formalized the concept of State Wellhead
Protection (WHP) Programs to protect wellhead areas to
public water supply wells from contamination. The Act
contains requirements for the minimum program elements
necessary to develop and implement a WHP program.
June 19, 1989 was the statutory deadline for
submission of state WHP programs. This paper presents
a summary of those programs that have been submitted
and provides a status report on the review and
approval process. Specific state examples are
presented to demonstrate innovative approaches to each
of the program elements. Implementation issues and
the role of the local government are explored.
Transfer of WHP concepts from other areas of the
country to the northeastern states is provided.
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Steven P- Roy
Source Management Unit
U.S. Environmental Protection Agency
Office of Ground-Water Protection
401 M St., S.W.
Washington, B.C. 20460
Steven Roy is currently the manager of the Source Management
Unit in EPA's Office of ground-Water Protection. His
responsibilities include overseeing the management of the Wellhead
Protection Program and developing technical assistance materials
for state and local officials on ground-water protection.
Prior to joining EPA, Mr. Roy worked for eight years as
Ground-Water Program Manager and Water Management Director for the
State of Massachusetts. There he developed numerous ground-water
protection programs including the Aquifer Land Acquisition Program
and a water allocation/permit program.
Also, Mr. Roy worked for the Berkshire County Regional Planning
Commission in Pittsfield, Massachusetts as an environmental
planner.
Mr. Roy has a B. S. in Forestry from the University of
Massachusetts, Amherst and an M. S. in Water Resources from the
State University of New York, Syracuse, N. Y.
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DEVELOPING AND PASSING STATEWIDE WELLHEAD PROTECTION PROGRAMS
CONNECTICUT: A CASE STUDY
Eric J. Brown
Murtha, Cullina, Richter and Pinney
CItyPlace
185 Asylum Street, P.O. Box 3197
Hartford, Connecticut 06103
Designing a comprehensive statewide wellhead protection program which is
effective, workable, and politically feasible poses serious challenges to any
state. The process is particularly difficult for those regions such as the
northeast where the general public has yet to perceive of severe shortages or
widespread contamination of their drinking water supplies. Yet proactive
approaches to address the growing pressures on ground-water supplies can be
successfully developed and are clearly preferable to the potential health and
financial costs associated with reactive approaches. One example of such a
proactive approach Is the aquifer protection legislation recently adopted in
Connecticut.
There are many methods and approaches which a state may use to develop
ground-water legislation. In Connecticut, a legislative task force supported by a
committed Department of Environmental Protection and spearheaded by strong
legislative leadership proved to be an effective mechanism for generating the
structure of their aquifer protection program. The open and cooperative process
which the task force utilized in formulating recommendations was a major factor in
the program's ultimate success in the legislature. Other important, yet distinct
processes included forging the task force recommendations into sound legislative
proposals, designing a legislative strategy, and shepherding the proposals through
an often treacherous legislative process.
Although the obstacles to developing comprehensive, statewide wellhead
protection programs are many, the unanimous votes in both chambers of the
Connecticut General Assembly offer strong evidence that such hurdles can be
overcome.
I. Introduction
Clean drinking water is generally considered to be a basic right of every
citizen and is a resource which most take for granted. How is a concept so
fundamental and seemingly uncomplicated as clean drinking water becoming a
controversial issue giving rise to a growing number of angry well owners, heated
local debates, and environmental lawsuits? The answer, at least in part, is
uncertainty about how clean is "clean" coupled with a philosophy of "don't tread
on me." The federal government continues to release updated standards on what
constitutes clean drinking water. These standards are, for the most part, a list
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of six syllable chemical names with concentrations which are difficult to
envision, subject to change, and meaningless to the average citizen.
Additionally, "clean" is a relative term whose meaning and significance varies
with the individual. Most of us remember our dad or uncle taking a big gulp from
a canteen or bottle of soda and passing it over to us. Some of us heartily
grabbed the container taking an equally big swig without giving a single thought
to germs or bacteria. For others, the unsterilized bottle neck held the seeds
from which the world's next great plague would surely sprout.
Coupled with the issue of what constitutes "clean" drinking water is the
problem that protecting ground-water supplies means protecting specific areas of
land which lie above it. Most of us are willing to send money to help storm
victims we have never met, pitch in and work for weeks to help a neighbor rebuild
a house or a barn lost to fire, perhaps even risk our lives to save a friend,
neighbor or even a stranger facing some imminent peril. Just don't try to tell us
how we can and cannot use our land, particularly when our neighbor may not have to
abide by the same constraints. Upon consideration of the societal notions of
private property along with public uncertainty regarding the severity of the
threat to their drinking water supplies, the concept of clean groundwater and its
protection assumes a very couplex nature with a strong emotional component.
In light of these underlying tensions, how can a local, state, or federal
government effectively assure its citizens a plentiful supply of safe drinking
water to which they have a fundamental right? The answer is they cannot--at least
not unilaterally. Ultimately, the people must decide how much government
regulation they are willing to endure in ensuring themselves a drinking water
supply which will remain reasonably plentiful and safe. Realizing this fact, many
have advocated a grass roots educational approach to protecting groundwater
drinking water supplies. Unfortunately, educating the public about one specific
issue in today's complex society generally requires either a tremendous amount of
time and money or a major catastrophe. Attempting to address an issue with the
complexity of ground-water protection in a proactive, grass roots fashion could
involve a prohibitive time span as growing development, population, and land
prices place increasing pressures on drinking water supplies from groundwater.
The remainder of this paper offers an alternative to a purely grass roots
approach to generating wellhead protection legislation. The contents are based on
the experiences of Connecticut which recently passed broad, flexible, and
effective wellhead protection legislation at the state level using a team
approach. It is hoped that some of the material herein will be useful for
individuals and organizations seeking to institute state groundwater protection
measures as well as to communities working to protect their ground-water drinking
water supplies at the local or regional level.
II. Team Approach
A. Legislator
The most important person in the process of developing and passing
ground-water legislation is likely to be the legislator who will ultimately
be the chief sponsor of a wellhead protection bill. This person acts as
coach and general manager of a widely diverse team. The legislator must be
willing to place wellhead protection at the top of his pr her priority list
for perhaps several legislative sessions and therefore will probably
represent a district having a major interest in protecting ground-water
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resources. Because of their critical role in the process, only legislators
who are committed to the successful development of wellhead protection
legislation are likely to be successful. It is also advantageous for this
role to be filled by a member of the majority party and of the legislative
committee responsible for environmental matters as this is the first
legislative committee which will have to approve the wellhead protection
bill. While neither extensive experience nor possession of a legislative
leadership position is necessary to achieve a successful result, political
savvy and having the respect of their legislative colleagues are strong
benefits.
B. State Agency
A second critical player in developing successful wellhead protection
legislation is the state agency responsible for environmental protection.
The agency must be willing and able to actively support the project by
providing personnel and technical assistance as required. In most instances,
the agency will have extensive experience in resource management as well as
knowledge of what types of protection programs have proven to be workable and
effective. This experience and knowledge are vital to the ultimate success
of the project.
C. Task Force
Once the legislator and the environmental agency are in a position to go
forward with the project, the most efficient way to proceed may be to have
the agency and the legislator work together in formulating legislation.
However, this method will probably fail as it likely is too far removed from
a purely grass roots approach. Input from a wider variety of interested
parties is required. Accordingly, the legislator and agency should work to
establish a legislative body charged with studying and making recommendations
regarding wellhead protection legislation. Such a body is not only necessary
to flush out and address the many complex issues involved in wellhead
protection, but also lends credibility to the ultimate proposals. In
Connecticut, the General Assembly allocated funds for the creation of a
legislative task force to study and make recommendations for protecting the
state's public drinking water supplies drawn from groundwater. The task
force provided the forum for identifying issues, along with developing and
evaluating proposals. So critical was Connecticut's Aquifer Protection Task
Force that a closer look at the structure and operation of such an entity is
merited.
1. Composition
The goal of a task force is ultimately to advise the legislature on
how to address the issue of protecting groundwater resources used for
drinking water. Accordingly, the legislator who will be the bill's
chief sponsor should chair the task force. If feasible under
legislative rules, a colleague from the other legislative chamber (House
of Representatives or Senate) of the General Assembly should act as co-
chair of the task force. This is an important consideration as
successful legislation will require a "champion" to politically usher it
through many potential pitfalls in both chambers of the General
Assembly.
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Other House and Senate members, both Republicans and Democrats,
should also be named to the task force. As discussed below, task force
legislators will likely be the most knowledgeable sources regarding the
legislation on the floor of the General Assembly. Having informed
legislators in each political "camp" will be important as the bill makes
its way through the legislative process.
In addition to legislative members, the state Environmental
Protection Agency should be represented at the highest level possible.
Having a highly-ranked and experienced agency representative on the task
force will help assure that the maximum possible amount of Agency
resources will be available to the task force and will also reflect the
level of commitment which the Agency holds for wellhead protection.
The remaining members of the task force should be chosen as
carefully as the co-chairs. It is important to have members who are
knowledgeable, committed to the project, and have flexible schedules
which will allow them to attend meetings arranged on short notice or on
an inconsistent time basis. Most critical to the selection process is
to ensure that many different perspectives are represented on the task
force. A valid approach in this selection process would be to list all
the broad interest groups which one would typically expect to oppose
land use control and increased commercial or industrial regulation.
These groups are generally well organized and often politically
powerful. It is therefore imperative that they be brought into the
process at the outset and that their concerns are understood and
addressed early. To this list should be added local, state, and
possibly federal governmental representatives whose agencies and
constituents might ultimately be affected by the recommendations of the
task force. The task force membership should be geared to represent as
many of these listed individuals, groups, or agencies as possible. Care
should be taken not to underestimate the importance of the agency which
handles state finances. Comprehensive wellhead protection is not free
and the task force needs to have an indication of the state's fiscal
response to its developing proposals.
Examples of those groups represented on the Connecticut Aquifer
Protection Task Force include: Connecticut Business and Industry
Association, Home Builders Association, town planners, local first
selectmen, environmental lawyers, private and public water utilities
along with representatives of the state Departments of Agriculture,
Health Services, and Environmental Protection.
The final critical element in assembling a task force is full-time
staffing. There are a multitude of administrational demands in
operating an effective and efficient task force for which the members
themselves cannot possibly take responsibility. Specific
responsibilities and suggestions on effectively staffing a task force
are discussed below.
2. Operation and Function
In Connecticut, Task Force meetings were conducted in formal
surroundings with room for interested citizens who wished to attend.
This setting provided an excellent forum for raising issues and
discussing well researched and concisely presented proposals. However,
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the meetings proved to be a rather ineffective forum for debating
specific problems in detail. Members often had difficulty with
effectively debating a point of contention with another task force
member who could be 20 feet away and only visible above the circular
committee dais from the neck up while two dozen other heads looked on.
For this reason, the meetings of the Connecticut Task Force were
generally designed to raise issues and review specific proposals on how
major issues might be addressed.
Once the major skeletal elements of the protection program were
defined, the co-chairmen of the Connecticut Task Force requested that
members volunteer to serve on subcommittees formed to address specific
issues associated with each element of the program. Examples included
the agriculture, water softener, land acquisition, regulation, and
mapping subcommittees. The subcommittees generally consisted of 4-7
persons and often included non-Task Force members as well. Groups of
this size were able to work informally around small tables, over coffee
or lunch and hammer out innovative and mutually agreeable proposals.
Each subcommittee was responsible for assembling and presenting a report
to the task force outlining their discussions and proposals. Each task
force member was then given an opportunity to review these reports prior
to discussing them collectively at a subsequent task force meeting. The
subcommittee approach proved very successful in Connecticut and was a
critical element in efficiently achieving a consensus on detailed
solutions to specific problems.
3. Use of Staff
Having at least one full-time employee to staff the task force is an
important element in maximizing its efficiency and productivity. The
main role of the staff is to act as a facilitator. Specifically, staff
should organize and monitor task force, subcommittee, and other
meetings; conduct research on issues related to the task force's goals;
maintain and utilize an updated mailing list of interested individuals
and organizations keeping them informed on the progress of the task
force; be available to quickly address crises as they arise; and
generally act as a vehicle of communication for the task force co-
chairs. It is important that the staff be able to work well with all
parties involved in the process including task force members, lobbyists,
and other legislative staff involved with researching and writing
environmental legislation. The staff may also play a significant role
in writing and editing reports which will be used to communicate the
work and proposals of the task force to legislators, lobbyists, interest
groups, state and local government officials, and interested citizens.
IV. Other Resources
The task force should be prepared to take maximum advantage of all the
resources at its disposal. This section highlights three examples of resources
which played important roles in assisting Connecticut's Aquifer Protection Task
Force.
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A. Lobbyists
Lobbyists are often portrayed as legislative mercenaries ready to carry
any flag for a price. In the vast majority of cases, this is not only a
false perception, but can be a terminal mistake for many legislative
proposals. Lobbyists should rather be viewed as potentially vital assets to
the task force in developing successful legislation as they represent a
valuable source of both technical and political knowledge. Additionally,
lobbyists who are incorporated into the process of developing proposals, will
often feel an extra incentive to work for the legislation ultimately written.
When the bill actually makes its way to the General Assembly, lobbyists can
be valuable foot soldiers responding quickly and competently to sudden
circumstances which may threaten the legislation. Again, it is important to
emphasize that having the environmental, conservation, and water company
lobbyists on your side is very helpful. The proposals have a significantly
better chance of surviving, however, if you can also count organizations
which represent developers, municipalities and business organizations as your
allies. A bill which protects clean drinking water and has the support of
such organizations is very difficult to vote against. However, such support
is likely to be achieved only if representatives of these organizations are
brought into the process early and given every opportunity to participate in
the development of the proposals.
B. Municipalities
Early on in the process of developing proposals, Connecticut's Aquifer
Protection Task Force arranged a trip for themselves and interested
individuals to visit two towns facing different challenges related to
protecting drinking water supplies from groundwater. The group heard
presentations from local officials regarding their efforts to develop
ground-water protection measures and the frustrations they encountered during
this process. Present and future wellfields were visited on tours of each
town hosted by local planning, utility, and conservation officials. During
these tours, different types of land uses near the wellfields were observed
in order to instill an appreciation for the real life issues which face
individual towns attempting to unilaterally protect their groundwater. The
trip proved valuable not only as an education experience, but also helped to
established a close relationship between the task force and the towns. These
communities constituted a continually expanding resource of knowledge gained
through experience which the task force could consult with as their work
proceeded.
C. Private Consultants
Inviting a private consulting firm to make a presentation to the task
force may serve several purposes. If skillfully constructed, such a
presentation can help improve the technical understanding of task force
members on the scientific aspects of protecting groundwater. Additionally,
such an event can help to establish a working relationship whereby the firm
could be called on informally for technical advice and expertise.
In Connecticut, task force members needed to expand their understanding
of groundwater cleanup technology in order to weigh this as an option in
designing a wellhead protection program. The presentation, along with
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follow-up discussions, allowed the task force to make an Informed decision on
this matter and to effectively communicate their decision in the annual
report.
V. Annual Report
For each legislative session, the task force should prepare an annual report
to the legislature. This should be done even if not required as such a report
documents the work and proposals of the task force for the year and helps to
define the challenges yet to be faced. Most importantly, a well written report
will enhance the reputation of the task force and lend credibility to its
proposals.
There are several issues to consider regarding the report. Most importantly,
the report should be well written, contain clear and understandable visuals which
assist the reader in synthesizing the scientific and socio-political elements
involved with wellhead protection, and be readable to a wide range of citizens.
It is fair to assume that many readers will not even know what a wellhead or
aquifer is. Protecting these resources, even at the state level, will involve
local officials and board members many of whom are volunteers with little or no
understanding of groundwater and the complex issues involved in protecting it.
Therefore, the report should start the reader at this elementary level and
gradually lead them to an understanding of the issues considered by the task force
and conclude with an explanation of the ideas proposed to address these issues.
It is a good idea to have several persons unfamiliar with the work of the task
force, but experienced in writing public information documents, review the draft
and make editorial suggestions. In Connecticut, a draft version of the 1989
report was widely circulated utilizing the mailing list mentioned earlier.
Additionally, a public hearing was held by the task force solely to gather
testimony regarding the draft report. A copy of the finished report should be
sent to each state legislator in order to raise their awareness of groundwater
issues, the work of the task force, and the specific proposals.
VI. Legislation
Writing the actual wellhead protection legislation involves a substantially
different process than that of writing the task force report. Here the emphasis
must be on technical correctness. As the proposals are likely to be broad in
scope and detailed in nature, writing the bill will be an arduous and painstaking
process for those unfamiliar with the intricacies of the proposals. For this
reason, it is important to have the legislative staff responsible for writing
environmental legislation fully informed on the progress of the task force and its
evolving proposals. The more involved these staff people are with the task force,
the more skillfully and efficiently they will be able to draft language which is
readable, understandable, and technically accurate. Furthermore, as the
legislation makes its way through the legislative process, it will likely be
subjected to close scrutiny and intense debate making some changes to the bill
inevitable. Having a staff attorney who is fully familiar with all the subtleties
of the bill will permit these changes to be made with maximum efficiency and in
such a way as to minimize their impact on the carefully constructed framework of
the legislation developed by the task force over months or years.
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VII. Legislative Process
Once the task force proposals have been synthesized into a legislative bill,
the final major challenge is shepherding the bill through the legislative process.
Much of the success in meeting this challenge will depend upon the political sense
and savvy of the chief legislative sponsor who must develop a strategy to guide
the bill through a legislative process full of pitfalls and trap doors.
The overall goal of the legislative strategy should be to anticipate problems
before they arise and to have all of the various resources cultivated during the
task force deliberations on hand and solidly prepared to address, in an efficient
and effective manner, any challenges which may threaten the bill.
In Connecticut, part of this strategy consisted of writing the legislation as
a House bill. In doing so, the larger chamber, composed of a wider range of
backgrounds and perspectives, had the first opportunity to debate the bill. If an
agreement could be reached which would allow the bill to pass by a comfortable
margin in the House, it was hoped there would be a greater opportunity for
successful consideration of the bill in the generally less volatile Senate.
A fundamental consideration in developing a legislative strategy is that not
every member of the legislature need be an expert on the details of the bill.
Those legislators who served on the task force will be the primary "experts"
within the legislature along with members of the Environment Committee to a lesser
extent. These legislators will provide the first line of defense, on both sides
of the isle, against any technical questioning or sudden attacks on the bill
occurring on the floor of either chamber. Assuming that not every member of both
the task force and the Environment Committee will be strong advocates of the bill,
it will be important for those who do support the bill to work actively on its
behalf. Off the floor, the corps of lobbyists who participated in developing the
bill should be kept up-to-date on any challenges or changes to the bill during
legislative debate. As major allies of your efforts, lobbyists must be totally
familiar with at least those portions of the bill which affect their clients in
order to function as effective advocates as the tense hours of legislative debate
unfold.
Along with legislators opposed to the bill, procedural pitfalls of the
legislature may pose a threat to the bill's survival and should not be
underestimated. Task force staff should have a good rapport with the staff of
legislative leadership and where possible, with the legislators themselves.
Keeping track of deadlines, filing requirements, and other procedural formalities
is extremely important as even a small oversight in this area can extinguish the
bill's chances even to be considered by the legislature.
Eventually, debate on the bill will come to a close. Months, perhaps years
of preparation, attention to detail, and dozens of concerted attempts to address
everyone's concerns will stand against the ultimate legislative test. A certain
sense of accomplishment is justified in having reached this point. Hundreds of
bills will have died in committee, been amended beyond recognition, or are doomed
as they lie dormant on the legislative calendar.
In Connecticut, most of the major concerns regarding the bill were identified
prior to the start of debate on the floor of the House. The cooperative efforts
of legislators, lobbyists, and staff allowed these concerns to be quickly
10
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addressed with clarifying language and reasonable compromises. Formal debate on
the floor was principally composed of answering questions for the record in order
to provide a clear documentation of legislative intent.
Ultimately, HB 6594 "An Act Concerning Aquifer Protection Areas ..."
unanimously passed the House of Representatives 137-0 and quickly won unanimous
approval in the Senate after a predictably short debate.
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Substitute House Bill No. 6594
PUBLIC ACT NO. 89-305
AN ACT CONCERNING AQUIFER PROTECTION AREAS, AND
LOCAL FLOOD AND EROSION CONTROL BOARDS.
Be it enacted by the Senate and House of
Representatives in General Assembly convened:
Section 1. (NEW) The general assembly finds
that aquifers are an essential natural resource
and a major source of public drinking water; that
reliance on groundwater will increase because
opportunities for development of new surface water
supplies are diminishing due to the rising cost of
land and increasingly intense development; that
numerous drinking water wells have been
contaminated by certain land use activities and
other wells are now threatened; that protection of
existing and future groundwater supplies demands
greater action by state and local government; that
a groundwater protection program requires
identification and delineation of present and
future water supplies in stratified drift aquifers
supplying drinking water wells; that a
comprehensive and coordinated system of land use
regulations should be established that includes
state regulations protecting public drinking water
wells located in stratified drift aquifers; that
municipalities with existing or proposed public
drinking water wells in stratified drift aquifers
should designate aquifer protection agencies; and
that the state should provide technical assistance
and education programs on aquifer protection to
ensure a plentiful supply of public drinking water
for present and future generations.
Sec. 2. (NEW) For the purposes of this act:
(1) "Regulated activity" means any action or
process the commissioner of environmental
protection determines, by regulations adopted in
accordance with section 3 of this act, to involve
the production, handling, use, storage or disposal
of material that may pose a threat to groundwater,
including structures and appurtenances utilized in
conjunction with the regulated activity;
(2) "Commissioner" means the commissioner of
environmental protection;
(3) "Well field" means the immediate area
surrounding a public drinking water supply well or
group of wells;
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Substitute House Bill No. 6594
(4) "Area of contribution" means the area
where the water table is lowered due to the
pumping of a well and groundwater flows directly
to the well;
(5) "Recharge area" means the area from which
groundwater flows directly to the area of
contribution;
(6) "Aquifer" means a geologic formation,
group of formations or part of a formation that
contains sufficient saturated, permeable materials
to yield significant quantities of water to wells
and springs;
(7) "Affected water company" means any public
or private water company owning or operating a
public water supply well within an aquifer
protection area;
(8) "Stratified drift" means a predominantly
sorted sediment laid down by or in meltwater from
glaciers and includes sand, gravel, silt and clay
arranged in layers;
(9) "Municipality" means any town,
consolidated town and city, consolidated town and
borough, city or borough;
(10) "Aquifer protection area" means any area
consisting of well fields, areas of contribution
and recharge areas, identified on maps approved by
the commissioner of environmental protection
pursuant to sections 22a-354b to 22-354d,
inclusive, of the general statutes, as amended by
this act, within which land uses or activities
shall be required to comply with regulations
adopted pursuant to section 8 of this act by the
municipality where the aquifer protection area is
located; and
(11) "Best management practice" means a
practice, procedure or facility designed to
prevent, minimize or control spills, leaks or
other releases that pose a threat to groundwater.
Sec. 3. (NEW) (a) On or before July 1, 1990,
the commissioner of environmental protection shall
adopt regulations in accordance with chapter 54 of
the general statutes for land use controls in
aquifer protection areas. The regulations shall
establish (1) best management practice standards
for existing regulated activities located entirety
or in part within aquifer protection areas and a
schedule for compliance of nonconforming regulated
activities with such standards, (2) best
management practice standards for and prohibitions
of regulated activities proposed to be located
entirely or in part within aquifer protection
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Substitute House Bill No. 6594
(b) The soil and water conservation district
where the aquifer protection area is located shall
establish and coordinate a technical team to
develop each plan. Such team shall include a
representative of the municipality in which the
land is located and a representative of any
affected water company upon request of such
municipality or water company. In developing a
plan, a district shall consult with the
commissioners of environmental protection and
agriculture, the college of agriculture and
natural resources at The University of
Connecticut, the Connecticut Agricultural
Experiment Station, the soil conservation service,
the state agricultural and conservation committee
and any other person or agency the district deems
appropriate.
(c) The plan shall include a schedule for
implementation and shall be periodically updated
as required by the commissioner. In developing a
schedule for implementation, the technical team
shall consider technical and economic factors
including, but not limited to, the availability of
state and federal funds. Any person engaged in
agriculture in substantial compliance with a plan
approved under this section shall be exempt from
regulations adopted under section 8 of this act by
a municipality in which the land is located. No
plan shall be required to be submitted to the
commissioner before July 1, 1991, or six months
after completion of level B mapping where the farm
is located, whichever is later.
(d) On or before July 1, 1990, the
commissioner of environmental protection, in
consultation with the commissioner of agriculture,
the United States Soil Conservation Service, the
cooperative extension service at The University of
Connecticut and the council for soil and water
conservation, shall develop regulations in
accordance with chapter 54 of the general statutes
for farm resources management plans. Such
regulations shall include, but not be limited to,
provisions for manure management, storage and
handling of pesticides, reduced use of pesticides
through pest management practices, integrated pest
management, fertilizer management and the location
of underground storage tanks. In adopting such
regulations, the commissioner shall consider
existing state and federal guidelines or
regulations affecting aquifers and agricultural
resources management.
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Substitute House Bill No. 6594
Sec. 7. (NEW) The zoning commission,
planning commission or planning and zoning
commission of each municipality with an aquifer
protection area shall delineate on any map showing
zoning districts prepared in accordance with
chapter 124 or 126 of the general statutes or any
special act the boundaries of aquifer protection
areas, including areas of contribution and
recharge areas as shown on level A maps approved
pursuant to section 22a-354c of the general
statutes, as amended by section 22 of this act.
Sec. 8. (NEW) (a) Each municipality in which
an aquifer protection area is located shall
authorize by ordinance an existing board or
commission to act as such agency not later than
three months after adoption by the commissioner of
regulations for aquifer protection areas pursuant
to section 3 of this act and approval by the
commissioner of mapping of areas of contribution
and recharge areas for wells located in stratified
drift aquifers in the municipality at level B
pursuant to section 22a-354d of the general
statutes. The ordinance authorizing the agency
shall determine the number of members and
alternate members, the length of their terms, the
method of selection and removal, and the manner
for filling vacancies. No member or alternate
member of such agency shall participate in any
hearing or decision of such agency of which he is
a member upon any matter in which he is directly
or indirectly interested in a personal or
financial sense. In the event of
disqualification, such fact shall be entered on
the records of the agency and replacement shall be
made from alternate members of an alternate to act
as a member of such commission in the hearing and
determination of the particular matter or matters
in which the disqualification arose.
(b) Not more than six months after approval by
the commissioner of mapping at level A, pursuant
to section 22a-354d of the general statutes, the
aquifer protection agency of the municipality in
which such well is located shall adopt regulations
for aquifer protection.
(c) At least one member of the agency or staff
of the agency shall be a person who has completed
the course in technical training formulated by the
commissioner pursuant to section 16 of this act.
Failure to have a member of the agency or staff
with training shall not affect the validity of any
action of the agency and shall be grounds for
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Substitute House Bill No. 6594
revocation of the authority of the agency under
section 13 of this act.
Sec. 9. (NEW) (a) The aquifer protection
agency authorized by section 8 of this act shall,
by regulation, provide for (1) the manner in which
the boundaries of aquifer protection areas shall
be established and amended or changed, (2) the
form for an application to conduct regulated
activities within the area, (3) notice and
publication requirements, (4) criteria and
procedures for the review of applications and (5)
administration and enforcement.
(b) No regulations of an aquifer protection
agency shall become effective or be established
until after a public hearing in relation thereto
is held by the agency at which parties in interest
and citizens shall have an opportunity to be
heard. Notice of the time and place of such
hearing shall be published in the form of a legal
advertisement, appearing at least twice in a
newspaper having a substantial circulation in the
municipality at intervals of not less than two
days, the first not more than twenty-five days nor
less than fifteen days, and the last not less than
two days, before such hearing, and a copy of such
proposed regulation shall be filed in the office
of the town, city or borough clerk, as the case
may be, 141 such municipality, for public
inspection at least ten days before such hearing,
and may be published in full in such paper. A
copy of the notice and the proposed regulations or
amendments thereto shall be provided to the
commissioner of environmental protection, the town
clerk and any affected water company at least
thirty-five days before such hearing. Such
regulations may be from time to time amended,
changed or repealed after a public hearing in
relation thereto is held by the agency at which
parties in interest and citizens shall have an
opportunity to be heard and for which notice shall
be published in the manner specified in this
subsection. Regulations or changes therein shall
become effective at such time as is fixed by the
agency, provided a copy of such regulation or
change shall be filed in the office of the town,
city or borough clerk, as the case may be.
Whenever an agency makes a change in regulations,
it shall state upon its records the reason why the
change was made. All petitions submitted in
writing and in a form prescribed by the agency
requesting a change in the regulations shall be
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Substitute House Bill No. 6594
(f) Any regulations adopted by an agency under
this section shall not be effective unless the
commissioner of environmental protection
determines that such regulations are reasonably
related to the purpose of groundwater protection
and not inconsistent with the regulations adopted
pursuant to section 3 of this act. A regulation
adopted by a municipality shall not be deemed
inconsistent if such regulation establishes a
greater level of protection. The commissioner
shall provide written notification to the agency
of approval or the reasons such regulations cannot
be approved within sixty days of receipt by the
commissioner of the regulations adopted by the
agency.
Sec. 10. (NEW) (a) The commissioner of
environmental protection or any person aggrieved
by any regulation, order, decision or action made
pursuant to sections 8 to 14, inclusive, of this
act, by the commissioner or municipality, within
fifteen days after publication of such regulation,
order, decision or action may appeal to the
superior court for the judicial district where the
land affected is located, and if located in more
than one judicial district, to said court in any
such judicial district, except if such appeal is
from a contested case, as defined in section 4-166
of the general statutes, such appeal shall be in
accordance with the provisions of section 4-183 of
the general statutes and venue shall be in the
judicial district where the land affected is
located, and if located in more than one judicial
district to the court in any such judicial
district. Such appeal shall be made returnable to
said court in the same manner as that prescribed
for civil actions brought to said court. Notice
of such appeal shall be served upon the aquifer
protection agency and the commissioner. The
commissioner may appear as a party to any action
brought by any other person within thirty days
from the date such appeal is returned to the
court. The appeal shall state the reasons upon
which it is predicated and shall not stay
proceedings on the regulation, order, decision or
action, but the court may, on application and
after notice, grant a restraining order. Such
appeal shall have precedence in the order of
trial.
(b) The court, upon the motion of the person
who applied for such order, decision or action,
shall make such person a party defendant in the
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Substitute House Bill No. 6594
appeal. Such defendant may, at any time after the
return date of such appeal, make a motion to
dismiss the appeal. At the hearing on such motion
to dismiss, each appellant shall have the burden
of proving his standing to bring the appeal. The
court may, upon the record, grant or deny the
motion. The court's order on such motion shall be
a final judgment for the purpose of the appeal as
to each such defendant. No appeal may be taken
from any such order except within seven days of
the entry of such order.
(c) No appeal taken under subsection (a) of
this section shall be withdrawn and no settlement
between the parties to any such appeal shall be
effective unless and until a hearing has been held
before the superior court and such court has
approved such proposed withdrawal or settlement.
Sec. 11. (NEW) (a) If upon appeal pursuant
to section 10 of this act, the court finds that
the action appealed from constitutes the
equivalent of a taking without compensation, it
shall set aside the action or it may modify the
action so that it does not constitute a taking. In
both instances the court shall remand the order to
the aquifer protection agency for action not
inconsistent with its decision.
(b) To carry out the purposes of sections 8 to
14, inclusive, of this act, a municipality may at
any time purchase land or an interest in land in
fee simple or other acceptable title, or subject
to acceptable restrictions or exceptions, and
enter into covenants and agreements with
landowners.
Sec. 12. (NEW) (a) If the aquifer protection
agency or its duly authorized agent finds that any
person is conducting or maintaining any activity,
facility or condition which violates any provision
of sections 8 to 14, inclusive, of this act, or
any regulation or permit adopted or issued
thereunder, the agency or its duly authorized
agent may issue a written order by certified mail,
return receipt requested, to such person
conducting such activity or maintaining such
facility or condition to cease such activity
immediately or to correct such facility or
condition. The agency shall send a copy of such
order to any affected water company by certified
mail, return receipt requested. Within ten days of
the issuance of such order the agency shall hold a
hearing to provide the person an opportunity to be
heard and show cause why the order should not
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Substitute House Bill No. 6594
remain in effect. Any affected water company may
testify at the hearing. The agency shall consider
the facts presented at the hearing and, within ten
days of the completion of the hearing, notify the
person by certified mail, return receipt
requested, that the original order remains in
effect, that a revised order is in effect, or that
the order has been withdrawn. The original order
shall be effective upon issuance and shall remain
in effect until the agency affirms, revises or
withdraws the order. The issuance of an order
pursuant to this section shall not delay or bar an
action pursuant to subsection (b) of this section.
The commissioner may issue orders pursuant to
sections 22a-6 to 22a-7, inclusive, of the general
statutes, concerning an activity, facility or
condition which is in violation of said sections 8
to 14, inclusive, if the municipality in which
such activity, facility or condition is located
has failed to enforce its aquifer protection
regulations.
(b) Any person who commits, takes part in, or
assists in any violation of any provision of
sections 8 to 14, inclusive, of this act, or any
ordinance or regulation promulgated by
municipalities pursuant to the grant of authority
herein contained, shall be assessed a civil
penalty of not more than one thousand dollars for
each offense. Each violation of said sections
shall be a separate and distinct offense, and, in
the case of a continuing violation, each day's
continuance thereof shall be deemed to be a
separate and distinct offense. The superior
court, in an action brought by the commissioner,
municipality, district or any person shall have
jurisdiction to restrain a continuing violation of
said sections, to issue orders directing that the
violation be corrected or removed, and to assess
civil penalties pursuant to this section. All
costs, fees and expenses in connection with such
action shall be assessed as damages against the
violator together with reasonable attorney's fees
which may be allowed, all of which shall be
awarded to the municipality, district or person
bringing such action.
(c) Any person who wilfully or knowingly
violates any provision of sections 8 to 14,
inclusive, of this act, shall be fined not more
than one thousand dollars for each day during
which such violation continues or be imprisoned
not more than six months or both. For a
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Substitute House Bill No. 6594
subsequent violation, such person shall be fined
not more than two thousand dollars for each day
during which such violation continues or be
imprisoned not more than one year or both. For the
purposes of this subsection, "person" shall be
construed to include any responsible corporate
officer .
Sec. 13. (NEW) (a) The commissioner of
environmental protection may revoke the authority
of a municipality to regulate aquifer protection
areas pursuant to sections 8 to 14, inclusive, of
this, act upon determination after a hearing that
such municipality has, over a period of time,
consistently failed to perform its duties under
said sections. Prior to the hearing on
revocation, the commissioner shall send a notice
to the aquifer protection agency, by certified
mail, return receipt requested, asking such agency
to show cause, within thirty days, why such
authority should not be revoked. A copy of the
show cause notice shall be sent to the chief
executive officer of the municipality that
authorized the agency and to any water company
owning or operating a public water supply well
within such municipality. Such water company may,
through a representative, appear and be heard at
any such hearing. The commissioner shall send a
notice to the aquifer protection agency, by
certified mail, return receipt requested, stating
the reasons for the revocation and ' the
circumstances for reinstatement.. Any municipality
aggrieved by a decision of the commissioner under
this section to revoke its authority under said
sections 8 to 14, inclusive, may appeal therefrom
in accordance with the provisions of section 4-183
of the general statutes. The commissioner shall
have jurisdiction over aquifers in any
municipality whose authority to regulate such
aquifers has been revoked. Any costs incurred by
the state in reviewing applications to conduct an
activity within an aquifer protection area for
such municipality shall be paid by the
municipality. Any fees that would have been paid
to such municipality if such authority had been
retained shall be paid to the state.
(b) The commissioner shall cause to be
published notice of the revocation or
reinstatement of the authority of a municipality
to regulate aquifers in a newspaper of general
circulation in the area of such municipality.
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Substitute House Bill No. 6594
(c) The commissioner shall adopt regulations
in accordance with the provisions of chapter 54 of
the general statutes establishing standards for
the revocation and reinstatement of municipal
authority to regulate aquifers pursuant to section
8 of this act.
Sec. 14. The commissioner of environmental
protection and the commissioner of transportation,
within available appropriations, shall study
methods to prevent contamination of drinking water
in aquifer protection areas through design,
construction and maintenance of transportation
routes. In conducting the study, said
commissioners shall consider prohibiting the
transportation of potential groundwater
contaminants through aquifer protection areas,
mandating containment molding and drainage control
in the design and construction of roads located
within aquifer protection areas and the
feasibility of nonsalt-based deicing material for
roads within aquifer protection areas. The
commissioners shall submit a report of their
findings and recommendations to the joint standing
committee of the general assembly having
cognizance of matters relating to the environment
on or before February 1, 1990.
Sec. 15. (NEW) The commissioner of
environmental protection shall develop an
incentive program to provide public recognition of
users of land located within aquifer protection
areas who demonstrate successful and committed
efforts to protect drinking water supplies by
implementing innovative approaches to groundwater
protection. Such program shall also promote
groundwater protection through education .of
members of businesses and industry and the public.
Sec. 16. (NEW) The commissioner of
environmental protection shall formulate courses
in technical training for members and staff of
municipal aquifer protection agencies. Such
courses shall provide instruction in the
regulations developed pursuant to section 3 of
this act, potential options for monitoring and
enforcement, and technical requirements for site
plan review. The commissioner may designate any
organization or educational institution to provide
such instruction.
Sec. 17. (NEW) The commissioner of
environmental protection, in consultation with the
commissioner of health services and the
chairperson of the department of public utilities
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Substitute House Bill No. 6594
control, shall prepare guidelines for acquisition
of lands surrounding existing or proposed public
water supply well fields. In preparing such
guidelines the commissioner shall consider
economic implications for mandating land
acquisition including, but not limited to, the
effect on land values and the ability of small
water companies to absorb the cost of acquisition.
Sec. 18. (NEW) (a) The commissioner of
environmental protection, in consultation with the
commissioner of health services and water
companies, shall provide, within available
appropriations, technical, coordinating and
research services to promote the effective
administration of this act at the federal, state
and local levels.
(b) The commissioner shall have the overall
responsibility for general supervision of the
implementation of this act and shall monitor and
evaluate the activities of federal and state
agencies and the activities of municipalities to
assure continuing, effective, coordinated and
consistent administration of the requirements and
purposes of this act.
(c) The commissioner shall prepare and submit
to the general assembly and the governor, on or
before December first of each year, a written
report summarizing the activities of the
department concerning the development and
implementation of this act during the previous
year. Such report shall include, but not be
limited to: (1) The department's accomplishments
and actions in achieving the goals and policies of
this act including, but not limited to,
coordination with other state, regional, federal
and municipal programs established to achieve the
purposes of this act; (2) recommendations for any
statutory or regulatory amendments necessary to
achieve such purposes; (3) a summary of municipal
and federal programs and actions which affect
aquifer protection areas; (4) recommendations for
any programs or plans to achieve such purposes;
(5) any aspects of the program or the act which
are proving difficult to accomplish, suggested
reasons for such difficulties, and proposed
solutions to such difficulties; (6) a summary of
the expenditure of federal and state funds under
this act and (7) a request for an appropriation of
funds necessary to match federal funds and provide
continuing financial support for the program. Such
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Substitute House Bill No. 6594
report shall comply with the provisions of section
46a-78 of the general statutes.
Sec. 19. (NEW) Each water company serving
ten thousand or more customers with wells in
stratified drift aquifers shall prepare a
municipal assistance program, which includes
recommendations for site plan reviews, evaluation
of risks and advice on procedures for dealing with
hazardous waste spills in aquifers. Such program
shall be made available to any municipality in
which wells owned by the water company are
located.
Sec. 20. (NEW) On or before the second
Wednesday after the convening of each regular
session of the general assembly, the commissioner
of health services shall submit a report to the
joint standing committee of the general assembly
having cognizance of matters relating to the
environment, which describes the status of, for
the year ending the preceding June thirtieth, the
water planning process established under sections
25-33g to 25-33J, inclusive, of the general
statutes, as amended by this act, and efforts to
expedite the process.
Sec. 21. Section 25-32d of the general
statutes is repealed and the following is
substituted in lieu thereof:
(a) Each water company as defined in section
25-32a and supplying water to one thousand or more
persons or two hundred fifty or more consumers and
any other water company as defined in said section
requested by the commissioner of health services
shall submit a water supply plan to the
commissioner of health services for approval with
the concurrence of the commissioner of
environmental protection. The concurrence of the
public utilities control authority shall be
required for approval of a plan submitted by a
water company regulated by the authority. The
commissioner of health services shall consider the
comments of the public utilities control authority
on any plan which may impact any water company
regulated by the authority. The commissioner of
health services shall distribute a copy of the
plan to the commissioner of environmental
protection and the public utilities control
authority. A copy of the plan shall be sent to
the secretary of the office of policy and
management for information and comment. A plan
shall be revised at such time as the water company
filing the plan or the commissioner of health
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Substitute House Bill No. 6594
services determines or at intervals of not less
than three years nor more than five years after
the date of initial approval.
(b) Any water supply plan submitted pursuant
to this section shall evaluate the water supply
needs in the service area of the water company
submitting the plan and propose a strategy to meet
such needs. The plan shall include, but not be
limited to: (1) A description of existing water
supply systems; (2) an analysis of future water
supply demands; (3) an assessment of alternative
water supply sources which may include sources
receiving sewage AND SOURCES LOCATED ON STATE
LAND; (4) contingency procedures • for public
drinking water supply emergencies, including
emergencies concerning the contamination of water,
the failure of a water supply system or the
shortage of water; (5) a recommendation for new
water system development; (6) such other
information as the commissioner of health
services, the commissioner of environmental
protection or the public utilities control
authority deems necessary^ [and) (7) a forecast of
future land sales^ AND (8) PROVISIONS FOR
STRATEGIC GROUNDWATER MONITORING.
(c) The commissioner of health services, in
consultation with the commissioner of
environmental protection and the public utilities
control authority, shall adopt regulations in
accordance with the provisions of chapter 54. Such
regulations shall include, but not be limited to,
a process for approval, modification or rejection
of plans submitted pursuant to this section and a
schedule for submission of the plans.
Sec. 22. Section 22a-354c of the general
statutes is repealed and the following is
substituted in lieu thereof:
(a) On or before July 1, 1990, each public or
private water company serving one thousand or more
persons shall map at level B all AREAS OF
CONTRIBUTION AND RECHARGE AREAS FOR its existing
[well fields located] WELLS LOCATED IN STRATIFIED
DRIFT AQUIFERS THAT ARE within its water supply
service area. On or before July 1, 1992, each
public and private water company serving ten
thousand or more persons shall map at level A all
AREAS OF CONTRIBUTION AND RECHARGE AREAS FOR its
existing [well fields located] WELLS LOCATED IN
STRATIFIED DRIFT AQUIFERS THAT ARE within its
water supply service area. The commissioner of
environmental protection may map at level B all
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Substitute House Bill No. 6594
existing [well fields located] WELLS LOCATED IN
STRATIFIED DRIFT AQUIFERS THAT ARE within the
water supply service area of any public or private
water company serving less than one thousand
pe rsons .
(b) Each public or private water company
serving ten thousand or more persons shall map all
[potential well fields] AREAS OF CONTRIBUTION AND
RECHARGE AREAS FOR POTENTIAL WELLS that are
located within stratified drift aquifers
identified as future sources of water supply to
meet their needs in accordance with the plan
submitted pursuant to section 25-33h, AS AMENDED
BY SECTION 24 OF THIS ACT^ (1) at level B two
years after approval of such plan and (2) at level
A four years after approval of such plan. The
commissioner of environmental protection shall
identify and make recommendations for mapping all
remaining significant [well fields] WELLS LOCATED
IN STRATIFIED DRIFT AQUIFERS not identified by a
public or private water company as a potential
source of water supply within the region of an
approved plan. Mapping of ANY OTHER AREA OF
CONTRIBUTION AND RECHARGE AREAS FOR potential
[well fields] WELLS LOCATED IN STRATIFIED DRIFT
AQUIFERS by the commissioner shall be completed at
a time determined by the commissioner.
Sec. 23. (NEW) (a) On or before July 1, 1995,
each public or private water company serving at
least one thousand persons but not more than ten
thousand persons shall map areas of contribution
and recharge areas at level A for each existing
stratified drift wells located within its water
supply area.
(b) Each public or private water supply
company serving at least one thousand but not more
than ten thousand persons shall map areas of
contribution and recharge areas for all of the
potential wells located in stratified drift
aquifers identified as future sources of water
supply in accordance with the plan submitted to
section 25-33h of the general statutes, as amended
by section 24 of this act, at level B not more
than two years after approval of the plan and at
level A not more than five years after approval.
Sec. 24. Section 25-33h of the general
statutes is repealed and the following is
substituted in lieu thereof:
(a) Each water utility coordinating committee
shall prepare a coordinated water system plan in
the public water supply management area. Such plan
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Substitute House Bill No. 6594
shall be submitted to the commissioner of health
services for his approval not more than two years
after the first meeting of the committee. The
plan shall promote cooperation among public water
systems and include, but not be limited to,
provisions for (1) integration of public water
systems, consistent with the protection and
enhancement of public health and well-being; (2)
integration of water company plans; (3) exclusive
service areas; (4) joint management or ownership
of services; (5) satellite management services;
(6) interconnections between public water systems;
(7) integration of land use and water system
plans; (8) minimum design standards; (and] (9) the
impact on other uses of water resources^ AND (10)
ACQUISITION OF LAND SURROUNDING WELLS PROPOSED TO
BE LOCATED IN STRATIFIED DRIFTS.
(b) The plan shall be adopted in accordance
with the provisions of this section. The
committee shall prepare a draft of the plan and
solicit comments thereon from the commissioners of
health services and environmental protection, the
department of public utility control, the
secretary of the office of policy and management
and any municipality, regional planning agency or
other interested party within the management area.
The municipalities and regional planning agencies
shall comment on, but shall not be limited to
commenting on, the consistency of the plan with
local and regional land use plans and policies.
The department of public utility control shall
comment on, but shall not be limited to commenting
on, the cost-effectiveness of the plan. The
secretary of the office of policy and management
shall comment on, but shall not be limited to
commenting on, the consistency of the plan with
state policies. The commissioner of environmental
protection shall comment on, but shall not be
limited to commenting on, the availability of
water for any proposed diversion. The
commissioner of health services shall comment on,
but shall not be limited to commenting on, the
availability of pure and adequate water supplies,
potential conflicts over the use of such supplies,
and consistency with the goals of sections 25-33c
to 25-33J, inclusive^ AS AMENDED BY THIS ACT.
(c) The commissioner of health services shall
adopt regulations in accordance with the
provisions of chapter 54 establishing the contents
of a plan and a procedure for approval.
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Substitute House Bill No. 6594
Sec. 25. (NEW) The commissioner of
environmental protection, in consultation with the
commissioner of health services, water companies,
and business and industry shall develop a
strategic groundwater monitoring plan to be
implemented in aquifer protection areas not more
than one year after completion of level A mapping
pursuant to sections 22a-354b to 22a-354d,
inclusive, of the general statutes, as amended by
this act.
Sec. 26. Section 19a-37 of the general
statutes is repealed and the following is
substituted in lieu thereof:
The commissioner of health services may adopt
regulations in the public health code (pertaining
to protection and location of new water supply
wells or springs for residential construction or
for public or semipublic use) for the preservation
of the public health PERTAINING TO (1) PROTECTION
AND LOCATION OF NEW WATER SUPPLY WELLS OR SPRINGS
FOR RESIDENTIAL CONSTRUCTION OR FOR PUBLIC OR
SEMIPUBLIC USE, AND (2) INSPECTION FOR COMPLIANCE
WITH THE PROVISIONS OF MUNICIPAL REGULATIONS
ADOPTED PURSUANT TO SECTION 9 OF THIS ACT.
Sec. 27. Section 22a-354e of the general
statutes is repealed and the following is
substituted in lieu thereof:
Not later than three months after approval of
the commissioner of environmental protection of
mapping of aquifers at level B, each [municipality
in which such aquifers are located, acting through
its legislative body, shall authorize any board or
commission, or shall establish a new board or
commission to] MUNICIPAL AQUIFER PROTECTION AGENCY
AUTHORIZED PURSUANT TO SECTION 8 OF THIS ACT SHALL
inventory land uses overlying the mapped zone of
contribution and recharge areas of such aquifers
in accordance with guidelines established by the
commissioner pursuant to section 22a-354f. SUCH
INVENTORY SHALL BE COMPLETED NOT MORE THAN ONE
YEAR AFTER AUTHORIZATION OF THE AGENCY.
Sec. • 28. Section 22-6c of the general
statutes is repealed and the following is
substituted in lieu thereof:
The commissioner of agriculture may reimburse
any farmer for part of the cost of the completion
of a component of a farm waste management system,
provided such component has been certified by the
Federal Agricultural Stabilization and
Conservation Service, and the cost is in
accordance with said certification. The total
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Substitute House Bill No. 6594
federal and state grant available to a farmer
shall not be more than seventy-five per cent of
SUCh cost. IN MAKING GRANTS UNDER THIS SECTION
THE COMMISSIONER SHALL GIVE PRIORITY TO CAPITAL
IMPROVEMENTS MADE IN ACCORDANCE WITH A FARM
RESOURCES PLAN PREPARED PURSUANT TO SECTION 6 OF
THIS ACT.
Sec. 29. Subsection (a) of section 25-84 of
the general statutes is repealed and the following
is substituted in lieu thereof:
(a) Any municipality may, by vote of its
legislative body, adopt the provisions of this
section and sections 25-85 to 25-94, inclusive,
and exercise through a flood and erosion control
board the powers granted thereunder. In each
town, except as otherwise provided by special act,
the flood and erosion control board shall consist
of not less than five nor more than seven members,
who shall be electors of such town and whose
method of selection and terms of office shall be
determined by local ordinance, except that in
towns having a population of less than
(twenty-five) FIFTY thousand the selectmen may be
empowered by such ordinance to act as such flood
and erosion control board. In each city or
borough, except as otherwise provided by special
act, the board of aldermen, council or other board
or authority having power to adopt ordinances for
the government of such city or borough may act as
such board. The flood and erosion control board
of any town shall have jurisdiction over that part
of the town outside any city or borough contained
the rein.
Sec. 30. (NEW) Not more than two months
after approval by the commissioner of
environmental protection of mapping at level B
pursuant to section 22a-354d of the general
statutes, the commissioner, in consultation with
the commissioner of agriculture, the cooperative
extension service at The University of Connecticut
and any other person or agency the commissioner of
environmental protection deems necessary, shall
inventory agricultural land uses overlaying the
mapped area. Such inventory shall include, but
not be limited to, the type and size of any
agricultural operation and existing farm resource
management practices. Any such inventory shall be
completed not more than four months after
commencement and shall be made available to
technical teams established pursuant to subsection
(b) of section 4 of this act.
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Substitute House Bill No. 6594
Sec. 31. (NEW) State regulations for aquifer
protection areas adopted by the commissioner of
environmental protection pursuant to section 3 of
this act shall be consistent with regulations
adopted by said commissioner for farm reso.ur.ces
management plans pursuant to section 6 of this
act. /
Sec. 32. This act shall take effect from its
passage, except that sections 1 to 13, inclusive,
and sections 15 to 28, inclusive, shall take
effect July 1, 1989.
Certified as correct by
Legislative Commissioner.
Clerk of the Senate.
Clerk of the House.
Approved , 1989
Governor, State of Connecticut.
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Eric J. Brown
Environmental Analyst
Murtha, Cullina, Richter and Pinney
CityPlace
185 Asylum Street, P.O. Box 3197
Hartford, Connecticut 06103
Mr. Brown received his B.S. degree in geology from the University of Rhode
Island in 1980. After serving as a geological assistant for Mobil Corporation, he
entered Boston College where he worked as a geophysical analyst at the school's
Weston Observatory and received his M.S. degree in 1985. Mr. Brown taught science
for five years at Greens Farms Academy in Westport, Connecticut before leaving to
become executive director of the Connecticut General Assembly's Aquifer Protection
Task Force. He is presently employed by the Hartford/New Haven law firm of
Murtha, Cullina, Richter and Pinney as an environmental analyst and is attending
Western New England College School of Law.
30
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ABSTRACT
PROTECTING GROUND WATER FROM THE
BOTTOM UP: LOCAL RESPONSES
TO WELL-HEAD PROTECTION
WALPOLE BOARD OF HEALTH:
GROUNDWATER PROTECTION PROGRAM IMPLEMENTATION
By Robin Chapell, R.S.
Health Agent
Walpole Board of Health
The Walpole Board of Health has instituted and regulated many programs
to protect its water from contamination. Walpole has been designated as a
sole source aquifer district so it is imperative that its water not be polluted.
The Board has adopted Underground Storage Regulations/ Toxic and Hazardous
Materials Regulations/ Private Well Regulations and Mandatory Sewer Connection
Regulations. The Board is also responsible for implementing several monitoring
programs in town to make certain, that particular landfills and industries
in sensitive areas are not contaminating our aquifer. The Health Department
has organized Household Hazardous Waste Collection Days to help alleviate a
certain amount of illegal dumping. The department has been responsible for
removal or testing of many residential underground tanks. Just recently the
Board of Health strengthened Title V by requiring a bigger set back to wetlands.
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"Walpole Board of Health: Groundwater
Protection Program Implementation"
By Robin Chapell/ R.S.
Health Agent
Walpole Board of Health
Towns and cities need to protect themselves from environmental degradation
at its local level. This should be its first line of defense. Towns and
cities should not wait til state and federal agencies do the work for them.
After all, pollution and degradation of the environment will first be felt
by the residents in the community. Its the residents that have the most at
stake if something happens. Each town has its own special problems/ history
and geography that can be more easily recognized at the local level rather
than by a state or federal agency. Day to day situations can be more easily
monitored locally on a routine basis. This in no way implies that well needed
protection should not occur at the state or federal level, but that it simply
cannot replace local involvement.
One of the best governing bodies to protect the local environment are
the local Boards of Health. They are charged with protecting the public health
of their community under Massachusetts General Laws Chapter III Section 31.
The Walpole Board of Health has taken its importance seriously and has instituted
many varied programs and regulations to protect its groundwater from contamination
as will be discussed later.
The Town of Walpole is located 19 miles south of Boston and 26 miles
north of Providence. Over 19,000 residents reside in town. Walpole is an
old mill town but now most of its residents work in Boston.
The Town of Walpole relies heavily on its aquifer for its drinking source.
In fact/ the town petitioned to be designated a sole source aquifer district
and in 1988, EPA, so did so. This means that Walpole has only one main source
for its drinking water. If this source is contaminated, all of Walpole's
drinking water will be in jeopardy. Being a sole source aquifer district
means certain state and federal projects in this area can be closely scrutinized
if it is felt they can be detrimental to the town's water. Long before Walpole
was designated a sole source aquifer district, the town saw the need to delineate
certain sensitive areas in town where certain activities could influence the
quality of the town's water. The town hired IEP Consultant Engineers to map
out Water Resource Protection Districts in the town.
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This map has been very useful to the Board of Health. When the Board
of Health reviews any preliminary plan, definitive plan, board of appeals
case, or notice of intent, the first question that is asked, is in what protection
district is it in? if it lies in the protection districts, they ask how can
the activity affect the aquifer? In certain instances in town, the Board
has restricted uses, turned down plans, and/or set up monitoring programs.
The monitoring programs help the Board keep up on present and future sources
of contamination. At least four monitoring programs have been initiated within
the town. They monitor either private landfills or industrial parks. Each
program, reports in writing, four times a year to the health agent, and in
turn is reported to the Board. Many times, the health agent is present during
the gathering of samples. The programs are continually updated. The Board
looks for the presence of VOCs, heavy metals, ph, conductivity, and ground-
water levels. If something shows up, more samples need to be taken to explain
its presence. If levels of an unwanted substance are too high, rise or monitoring
ceases that would be reason enough to close the activity down. These monitoring
programs are written in covenants and go with the land, not the owner, to
insure long term participation of these mandatory programs.
The Board of Health also regulates all underground storage tanks. The
Board promulgated regulations on its registration, usage and testing of the
tanks. In the town's most sensitive water protection districts, no new tanks
can go in. All commercial tanks, at age 20 must be removed. Residents have
the option to biyearly test their tanks for leaks if they choose not to remove
them. Town owned tanks are also being removed and replaced. All new underground
tanks must be approved by the fire department and placement of these tanks
must be approved by both the Water and Sewer Commission and the Board of Health.
In 1988 the health department negotiated for the residents with a tank testing
company to come to town and test residential tanks at a very reduced rate.
About 16 tanks were tested. Other residents chose to remove their tanks and
replace them with basement heaters or some switched to gas. At age 15, all
tanks, commercial and residential must be put on a tank tightness monitoring
program. Results are forwarded to the Health Department. All underground
storage tanks in town must register with the Board of Health. All the information
is computerized. Information can easily be retrieved in regards to the age,
type, location, and water protection district of the tank. Since the beginning
of this program many unused tanks have been ordered to be removed from Walpole.
All tanks that are removed are inspected by the fire department and the health
agent. If the integrity of the tanks that are being removed are in question,
all surrounding soils will be treated as hazardous materials.
The Board of Health also regulates toxic and hazardous materials used
in industries using 25 pounds or 50 gallons of hazardous materials stored
on their premises at one time. This information has also been computerized
and shared by the fire department. Each initial registration is followed
by a site visit by the health agent. All new companies in town must comply
with these Board of Health regulations before the town will issue them an
occupancy permit. The health agent requires proper storage of all toxic and
hazardous materials. The Board of Health is also sent all Material Safety
Data Sheets| from companies dealing with hazardous materials.
The Board of Health also regulates the town bylaw for Mandatory Sewer
Hook Up. Every residence, in all Water Protection Districts, must hook up
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to sewer: if sewer is available. The time allowed for compliance for this
relatively new by law depends on what water protection district they are in.
Recently, the health department, had to take a few residents to court because
they have decided not to hook up. Fortunately, as of this writing, the town
has to contend with only one remaining stand out.
Private Well Regulations have recently been implemented by the Board.
All new drinking water wells must be tested for VOCs, heavy metals, coliform,
bacteria, water depth, and pump rate. If the wells do not meet federal standards
for drinking water they cannot be used. Certain standards, such as manganese,
can be met with the aid of a filter. All new dwellings, if on private wells,
will not get their occupancy permit until the Health Department okays their
well. Old well owners are continually encouraged to register their wells,
but the health department knows its information is not nearly complete. The
location of wells is very helpful in knowing how best to protect certain areas,
which areas need to be protected, and what activities should be restricted
where, there are certain flaws with the Board's well regulations. The biggest
flaw is that only an initial test is required. The Health Department educates
as many well owners as possible to the importance of regular testing for their
drinking waters. The town tests its drinking water monthly. Hopefully, this
year the Board will be reexamining these regulations and will be making them
stricter where applicable.
The Board recognizes the problem of illegal dumping of hazardous materials
and sometimes the legal improper disposal of these materials. In 1986 the
Board of Health started implementing a yearly Household Hazardous Waste Day.
Each year this event has become bigger and more costly to the town due to
the increasing participation of the residents.
The Board of Health in Walpole is committed to continuing with this program
in addition to exploring other ways to solve these problems. The Health Department,
through school visits, articles in town papers, and talking to residents are
trying to educate the citizens in using alternative safer household products,
reducing quantities, and recycling.
Very recently the Board of Health examined Title V and its own septic
system regulations to see if it met the town's needs. The Board, after months
of deliberation, decided to strengthen the regulations by requiring a 100
foot set back from the septic tank and 150 foot set back from the leaching
field to wetlands. The Board discussed distances bacteria and viruses could
travel and came up with setbacks they felt more comfortable with for the Town
of Walpole.
The Board of Health in Walpole follows up on leads about illegal dumping,
business practices that might eventually harm the environment and any accidental
spills in town. This way they can routinely press for clean up, monitor its
progress, and hopefully prevent disasters.
The community has been very receptive and appreciative to the Board of
Health in protecting the environment. Other departments have worked hand
in hand implementing these programs. With little desention, the residents
and businesses have complied and taken an active role in voicing their concerns
and coming up with suggestions to protect Walpole's groundwater.
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BIOGRAPHICAL SKETCH
Robin Chapell, R.S.
Health Agent
Walpole Board of Health
Town Hall/School St.
Walpole, Ma. 02081
Robin Chapell is the Health Agent for the Town of Walpole. She has a B.S. in
Environmental Studies from Worcester Polytechnic Institute and an M.S. in
Environmental Sciences (Environmental Health Management) from the Harvard
University School of Public Health. Ms. Chapell is also a registered sanitarian.
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Case Study of Regional Effort: Wellhead
Delineation as a Tool for Fostering
Regional Cooperation
submitted by
Marilyn F Cohen, Director
North Kingstown Department
of Planning & Development
80 Boston Neck Road
North Kingstown, RI 02852
(401) 294-3331
Timothy Brown
Executive Director
Kent County Water
Authority
PO Box 192
West Warwick, RI 02893
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ABSTRACT
Case Study of Regional Effort: Wellhead Delineation as a Tool for Fostering
Regional Cooperation
The presentation proposed is based on current efforts to achieve regional
cooperation in pursuit of groundwater protection. The regional setting is the
Hunt Aquifer in Rhode Island, an aquifer with the capacity to deliver eight
million gallons of water per day. The waters of the Hunt Aquifer are distri-
buted to a population of over 50,000 by three different water suppliers, the
North Kingstown Water Department, the Kent County Water Authority, and the
Rhode Island Port Authority. Five public supply wells lie within 1000 feet of
one another. The primary reservoir area is located at the boundary confluence
of three municipalities, each with distinct political and land use control.
Wellhead delineation has become the vehicle for fostering a regional
cooperative effort. The water suppliers have recognized that the results of a
wellhead delineation study are a tool for determining future acquisition to
protect wellheads; for assigning locations for monitoring potential contamina-
tion sites; and for providing information and direction to the three
municipalities for land use regulation purposes. Additionally, it was
recognized that the proximity of the wells and the likely pumping interaction
necessitated a joint effort. To this end the three water suppliers have
committed funding available in July, 1989, to contract for consulting services
to conduct the wellhead delineation study.
Since November 1988, an ad-hoc committee composed of representatives of
the water suppliers and the municipalities has been meeting to discuss issues
related to groundwater protection as well as institutional constraints to
regional cooperation. Dissimilar municipal zoning, subdivision, and other
regulations are being reviewed. To expand the current information base
available for the wellhead study, the water suppliers have authorized a
cooperative water quality sampling program for their wells. The municipalities
have inventoried land uses with potential for contamination: respective fire
departments have focussed on the well area for MSDS inventorying. Formaliza-
tion of committee efforts is anticipated.
In summary, wellhead delineation became a tool for fostering a regional
cooperative effort for protecting the groundwaters of the Hunt Aquifer. This
effort has led to involvement of water suppliers and municipalities in
expanding the land use data base and pursuing techniques that address long-
term groundwater protection.
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Case Study of Regional Effort: Wellhead Delineation
Tool for Fostering Regional Cooperation
Introduction
Background and Setting
This discussion is based on efforts to achieve
regional cooperation in pursuit of groundwater protection
for the Hunt Aquifer in Rhode Island. The waters of the Hunt
Aquifer are distributed to a population of over 50,000
people by three different water suppliers; -the Town of
North Kingstown Water Department, the Kent County Water
Authority, and the Rhode Island Port Authority, Five of the
seven public water supply wells in the Hunt Aquifer and
belonging to the three water suppliers lie within 1000 feet
of one another. The primary reservoir area, and the site of
the five wells, is located at the confluence of three
municipalities: the Towns of East Greenwich and North
Kingstown and the City of Warwick.
No models existed in Rhode Island upon which to base
the regional effort for groundwater protection. Peculiar to
Rhode Island is the fact that there are no recognized
regional planning agencies. Additionally, the 39 cities and
towns that comprise the Rhode Island communities
historically have operated independently of one another.
Only a few examples exist of intercommunity cooperation.
In the idealised world a community draws its water
resources from within its own boundaries and, thus, would be
able to control the land use activities that could
contribute to the quality of the drinking water. A board of
health would exist to monitor water quality and advise the
community on protection of its resources. Unlike other New
England states, no board of health exists at the local level
in Rhode Island to monitor water quality. The Rhode Island
Department of Health (RIDOH) does monitor water quality but
because its responsibility includes the entire state, it is
unable to focus on individual systems and land use. The
responsibility of assuring water quality rests with the
water supplier, an agency or department that is rarely
staffed with environmental or planning capacity. Moreover,
in the case at hand groundwater crosses municipal boundaries
such that, except for a portion of the Hunt Aquifer lying
within the Town of North Kingstown, none of the three water
suppliers is able to control the land use around their
respective water supply wells.
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Hydrologic setting
The setting for this discussion is the Hunt Aquifer
located in Rhode Island along the west passage of
Narragansett Bay. Figure 1 shows the location of the Hunt
Aquifer (Number 11). The Hunt Aquifer is in the Potowomut
River sub-basin drained by the Hunt, Maskerchugg, and
Potowornut Rivers. The Hunt River flows northeastward and
eventually discharges into Potowomut Pond. The Hunt Aquifer
is a sand and gravel aquifer whose transrnissivities range
from 1000 to more than 4000 gallons per day per foot. The
saturated thickness of the aquifer ranges from less than 20
feet to more than 100 feet. A groundwater reservoir where
transmissivity is greatest is located generally along the
Hunt River basin. All of the wells are located adjacent to
the Hunt River.
The groundwater quality is considered to be generally
good. Some chemical and volatile organic compound
contamination has become evident. The aquifer system is
vulnerable to contamination due to high permeability of
stratified drift, the absence of a confining layer of soil,
and in some areas, a relatively high water table. All of
these conditions offer little resistance to the attentuation
of pollutants.
Drinking Water Supply and Demand
The North Kingstown Water Department (NKWD), the Kent
County Water Authority (KCWA), and the Rhode Island Port
Authority (RIPA) share the Hunt Aquifer which has an
estimated potential yield of 8 million gallons per day.
This yield can be withdrawn using the existing pumping
facilities. The KCWA has the capacity to withdraw 1.0 mgd
from its one well; the RIPA has the capacity to withdraw
4.30 rngd from three wells; and the NKWD has the capacity to
withdraw 3.67 rngd from three wells located in the Hunt
Aquifer groundwater reservoir. Projections for the area
served by the Hunt Aquifer indicate that the total resources
available will be necessary in order to adequately serve new
growth. A lack of alternative drinking water resources was
documented in the Sole Source Aquifer petition for the Hunt
Aquifer.
Kent County Water Authority is a public benefit
corporation that supplies public water to all or a part of
the Rhode Island cities of Cranston and Warwick and the
Towns of Scituate, West Warwick, Coventry, East Greenwich,
and West Greenwich from the Scituate Reservoir. The
available 1.0 rngd from the Authority's well in the Hunt
Aquifer is distributed to residents and businesses in the
eastern portion of the Town of East Greenwich and the
Potowomut area of the City of Warwick to approximately 8000
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Area wide Water
lity Management
Plan
Figure i
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services in total. During peak periods the Authority draws
the maximum capacity from the well to supplement the supply
drawn from the Scituate Reservoir,
The Rhode Island Port Authority, a state agency and
subset of the State Department of Economic Development, is
the governing body for over 1500 acres of industrial land
located within the Town of North Kingstown. This land is
known as the Quonset Foint/Davisville Industrial Park and
was acquired by the State from the Federal government
following the withdrawal and closure in 1973 of most of the
Navy facilities once located at Quonset Point and
Davisville. The Port Authority also acquired the water
supply wells that provided public water to the Navy base.
One of those wells is located in East Greenwich and two are
located in Warwick. Figure 2 shows the location of the
wells in the confluence of the three municipal boundaries.
The Port Authority has available to it in its three wells
4.30 rngd; in 1988 the average daily use was only 0.80 rngd.
The Port Authority expects to reach its pumping capacity in
several years as expansion continues at the Park with
additional industrial development. Several industrial firms
with large water demands have recently made commitments to
locate at Quonset Point,
The Town of North Kingstown had an estimated 1985
population of 25,100. Ninety percent of the homes in the
Town are serviced by the public water supply system. It is
anticipated that the majority of new development will be
connected to public water. The Town at present is wholly
dependent on the use of individual septic disposal systems
for the treatment of domestic sewage. North Kingstown still
has extensive potential for additional growth due to the
availability of land for suburban development. The North
Kingstown Planning Commission has granted final approval for
in excess of 600 lots over the last two years and
approximately 550 lots exist in the review pipeline.
Projections based on build-out growth scenarios indicate all
water resources now available to the Town would be required
to serve the potential development. In addition to its
wells in the Hunt Aquifer, the Town draws groundwater from
two other aquifers--the Annaquatucket and the
Pettaquamscutt Aquifers--which are hydrogeologically
connected to the Hunt and were part of the Sole Source
Aquifer designation. The Annaquatucket has a potential
yield of 3 6 mgd and the Pettaquamscutt a potential yield of
1.8 rngd. The two aquifers combined would not provide
sufficient yield to deliver the peak demand of 7.38 rngd
(July, 1988) required by the Town. Unlike the Hunt, both
the Annaquatucket and the Pettaquarascutt Aquifers lie within.
the Town bounds.
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Land Use Setting
Six wells are proposed for the wellhead delineation
study. Five of these wells lie within 1000 feet of one
another near the intersection of Frenchtown and Post Roads
(see identified area in Figure 2); the sixth well lies
approximately 3500 feet west of the Frenchtown and Post Road
intersection.
Post Road is U.S. Route 1 and has been a primary
transportation route since the founding of the colonies.
Today this area is densely developed with residential,
commercial, and industrial land use. None of the area
around the wells is sewered. Yet residential development
densities range from two-acre lots to 7000 square foot
parcels. Industrial development is not as extensive as the
commercial development activities. A large tool and die
manufacturer has a private sewer treatment system that
discharges to the Hunt River approximately 1200 feet from
the location of three of the wells. Commercial development
is varied but includes automobile repair and service
facilities, several hair salons, and several shopping plazas
including one that pre-dates current soiling and septic
disposal regulations.
II. Impetus for Wellhead Delineation Study
The Town of North Kingstown took the initiative to use
wellhead delineation to protect groundwater. The Town has
had a history of groundwater protection beginning in 1974
with the adoption of groundwater reservoir and recharge
overlay districts within its zoning ordinance. By late
1987, however, there was evidence to suggest the need to
review and refine the mapping upon which the zoning was
based and the effectiveness of the existing regulations.
Whatever new mapping or regulations might be adopted, it was
apparent that in the Hunt Aquifer, unlike the other Town
aquifer systems, a regional approach to protection would be
needed.
At least three factors led to a decision by the North
Kingstown Town Council to authorise undertaking wellhead
delineation studies for the four wellfield areas in which
the Town's ten public water supply wells lie. First, there
existed a heightened consciousness among Town officials and
residents about groundwater protection as the Town undertook
efforts to halt the expansion of an existing demolition
debris landfill located within the drainage basin of the
Annaquatucket Aquifer.
Secondly, a growing awareness of the vulnerability of
local groundwater reserves, as well as a recognition of
limited alternatives, was one product of research
conducted by the Towns of East Greenwich and North Kingstown
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Figure 2: Boundary Line Confluence
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in the preparation of a joint petition to the United States
Environmental Protection Agency (USEPA) for Sole Source
Aquifer status. This petition was prepared in the Fall of
1987. The aquifer system was designated a sole source
aquifer in May, 1988 by USEPA.
Additionally, North Kingstown Planning and Public Works
Department staff had attended area wellhead delineation
conferences where the mandate of the federal legislation and
the underlying concepts of wellhead delineation were
explained. What was made perfectly clear was the fact that
wellhead delineation would be required in the future. But
more importantly, it was evident that wellhead delineation
was a technique that could be used to refine aquifer mapping
and allow for the determination of the sones of contribution
to existing and future public water supply wells. In turn,
the delineation could provide the basis for decisions in:
assigning appropriate land use; identifying parcels for
acquisition in pursuit of groundwater protection; and
identifying sites of potential contamination and
establishing monitoring programs. Town staff conveyed the
conference messages to Town officials and the Planning
Commission who pressed the Town Council for funds to
accomplish wellhead delineation studies,
III. The need for a regional effort
At the request of the North Kingstown Planning
Commission, the Town Council approved the creation of a Town
Groundwater Committee to undertake necessary wellhead
studies to insure Town planning and development activities
were in concert with protection of the drinking water. The
newly formed Groundwater Committee established a
prioritisation of the wells and wellfielcls based on quantity
and quality of the supply. With their ability to each
deliver 1.5 million gallons per day, the Town's two Hunt
Aquifer wells located in East Greenwich and Warwick were
given the highest priority. Planning Department to proceed
with the necessary steps to accomplish a delineation of
these wells. USEPA Office of Groundwai.er Protection
representatives provided the delineation examples that led.
to the important recognition of interrelationships among
proximate wells. For the first time, the Committee
understood that what had been anticipated as a projected
study of ten wells would, actually be one of four wellfields.
IV, Getting underway with regional efforts
In November, 1988, the Town of North Kingstown hosted a
meeting to which representatives of the three Hunt water
suppliers and. the communities that underlie the Hunt. Aquifer-
were invited. Also invited to the meeting were
representatives of state agencies whose purview includes the
protection of the state s drinking water resources: the
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Rhode Island Department of Health; the Rhode Island Water
Resources Board; the State Division of Planning; and the
Rhode Island Department of Environmental Management. The
primary purpose of the meeting was to bring together those
parties with vested interest in assuring the continued
quality of the Hunt Aquifer. From the Town's perspective it
was clear already that a wellhead delineation study must be
accomplished. A secondary purpose was to explore the
assistance, both financial and technical, that would be
available from state agencies for assisting in protection
efforts.
State representatives outlined their respective
jurisdictions and the few financial assistance programs
available but no state office offerred to play key roles in
assisting what could and would become a regional effort.
The only resolution agreed upon was that the three water
suppliers and the three communities should continue to meet.
From the discussion it was evident that of far more
consequence immediately than studies of future quality was
concern about finding ways to address present quality and
the levels of VOC's that were evident in the wells.
Uppermost was the recognition that it would be difficult to
replace the 8 mgd should contamination force their
abandonment. Impressive also was the presentation by the
Department of Health of the proposed National Primary
Drinking Water Regulations both future standards and
required water sampling analyses that were to be adopted and
mandated.
V. Obstacles to Achieving a Regional Effort
Over the months that followed the water suppliers and
the municipalities continued to meet on at least a monthly
basis. One difficulty was overcoming the differing contexts
from which each participant came. The municipal planning
officials tended to view the task in protection terms while
the KCWA and RIPA focused on the current quality of the
water. Both water supply agencies expressed skepticism
about working cooperatively with the same municipalities
whose land use decisions were viewed as the reason for
declining water quality.
Over the last fifteen years both the KCWA and the RIPA
had protested and, even filed suit, over municipal
development approvals near their wells. None of the three
municipalities was without direct responsibility for the
character of the development in the wellfield areas. Zone
changes, subdivision approvals, and zoning board of review
variances and special exceptions have created an area with
little open space, extensive impervious area, and uses
incompatible with the long-term protection of the
groundwater quality.
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Each meeting was a forum for consciousness raising
about different aspects of groundwater protection as well as
the state of the water quality. Two possible avenues of
regional effort were most obvious: a wellhead delineation
study for the wells lying together at the East
Greenwich-Warwick-North Kingstown boundaries; and a program
of regional planning that could use. the results of the
wellhead study for proper land use decision
Finding a common direction towards wellhead delineation
was impossible until a number of issues had been addressed
and all parties were convinced of the following
assumptions: 1) a wellhead delineation study was in the
best interest of each water supplier; 2) identifiying the
sources of present contamination now evidenced in the wells
would require some level of delineation; 3) such delineation
would be required by the Federal and State governments; and
4) a joint initiative would be cost-effective. The latter
assumption was the only one readily accepted based on the
close proximity of the wells and intuitive in the general
principles associated with cost savings.
Discussion of protecting groundwater that shows
evidence of contamination first raised questions about
whether protection should be considered at all. Should
funds be directed at remediation instead? Could the water-
supply be counted on as a future resource? Was abandonment
a likely outcome? Could protection now overcome the effects
of decades of poor land use decisions? These questions were
raised primarily by the water suppliers who had recognised
that the funding of such a study would be their
responsibility, Each of these questions needed a response
prior to consideration of committing to a wellhead study.
VI. Obstacles to Accomplishing Delineation
Funding
Each participant in the ad hoc committee recognized that
undertaking a wellhead delineation study would require
significant funding resources. With no available state or
regional planning grants, the municipalities viewed the
water suppliers as the appropriate funding source as several
options for funding would be available to them. First, the
water suppliers could request rate increases to cover the
costs within a capital budget item. Secondly, a one cent
per hundred gallons surcharge was available to water supply
systems to use for planning efforts (pers commun. Peter
Calise, Rhode Island Water Resources Board).
Expertise
None of the representatives of the water supply systems
or the municipalities had experience with conducting a
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wellhead delineation study. In the winter of 1989 when the
committee initiated discussions about wellhead delineation
even the State had not yet prepareds the Federally required
Wellhead Protection (WHP) Program which would later be
submitted to USEPA. The committee was armed only with USEPA
manuals describing wellhead techniques.
VII. Accomplishments
The efforts of the ad hoc committee have not been
without significant accomplishments. Over the last nine
months jointly or independently the water suppliers and the
municipalities have undertaken projects that directly
support the wellhead delineation and future protection
efforts.
Land Use Mapping of Potential Contamination Sources
In preparation for the wellhead delineation study and
in an effort to support the study, all three municipalities
undertook the mapping of land use within the Hunt Aquifer
with potential for contamination. Commercial, industrial,
and densely developed residential areas were plotted.
Research was conducted during the summer of 1989 by an
intern shared by North Kingstown and East Greenwich. The
intern investigated RIDEM records regarding underground
storage tanks, RCRA sites, and similar locations in order to
map contamination sites for future monitoring programs.
While the mapping was successfully accomplished for each
community, the effort was impeded by the dissimilar scale of
town maps. Time and financial constraints also contributed
to the inability to map the Hunt Aquifer on one piece of
paper.
Water Sampling
In response to the evidence of low levels of VOC
contamination, the water suppliers undertook a joint program
of water sampling analysis. This effort was also undertaken
to supplement and confirm the results of the water sampling
that is annually conducted by the Department of Health. The
program developed by the water suppliers was designed to
present a picture of the Hunt groundwater quality,
particularly in the wellfield. The sampling was conducted
once a month for five months. Each sampling round included
a sample from five wells and each sample was drawn on the
same day at proximate times to insure establishing a
snapshot of impacts on the wells. The samples were analyzed
by the University of Rhode Island's School of Oceanography.
The sampling period spanned the Spring and early Summer
months specifically to test for differences among seasons.
The sampling effort produced results that showed
increasing levels of one VOC at one well site. Armed with
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the findings of the water sampling program and evidence of
increasing contamination in a well with the ability to
deliver over 1.0 mgd, a request for a contamination
investigation by the State DEM was made. That study is now
in progress. Without the supplemental sampling and without
the mutual support of the water suppliers, it is likely that
such a study would have been accomplished.
Inventory of Haaardous Materials
The North Kingstown and East Greenwich Fire Departments
are participating in the regional effort to monitor and
protect the groundwater in the wellfield area. To that end,
the respective fire departments have earmarked the area
around the wells for the first priority in inventorying
hazardous substances handled by commercial and industrial
uses. Each of the Departments is equipped with computer
software that will allow an analysis and comparison of the
materials identified at business establishments with the
type of contamination evident in the Hunt wells. Because
the Potowornut section of Warwick is non-continguous to the
rest of the city but instead lies adjacent to East
Greenwich, the East Greenwich Fire Department is responsible
for the area within the Hunt Aquifer that lies in Warwick
and East Greenwich.
VII. Other Issues
Land Use Regulation
Regional cooperation will always be constrained by the
effects of dissimilar zoning, subdivision, and other
municipal regulations. At present, North Kingstown and East
Greenwich are preparing or modifying aquifer protection
ordinances; Warwick is awaiting the results of a wellhead
study to appropriately designate a protected area.
Staffing and Financial Resources
To date, the Town of North Kingstown has provided the
ongoing staffing for the committee for preparation of
agenda, etc. The Town has also agreed to provide the
necessary staffing for developing and accomplishing the
process of Requests for Qualifications and Proposals.
Necessary to the long term maintenance of a regional
organisation will be the requisite staffing and appropriate
funding to support that staff. The regional effort would
benefit from additional funding resources. Groundwater
resources are most likely to cross municipal boundaries and
be shared by several water supply systems. From a public
policy point of view and based on the experience of the Hunt
Aquifer committee, regional efforts should be encouraged and.
supported with financial, legal, and technical assistance.
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VII. Summary
In spite of what may seem like many obstacles, the
three water suppliers whose wells lie within the Hunt
Aquifer are preparing to undertake a wellhead delineation
study. At writing time, an agreement formalising an
association of the three bodies for accomplishing the study
was expected within weeks. The funding for the study will
be entirely provided by the water suppliers in equal shares.
No direct funding of the wellhead study will be provided by
the municipalities.
The proposed regional wellhead delineation study is the
first such effort to be undertaken in Rhode Island.
Technical assistance has been available upon request from
the State Department of Environmental Management and the
USEPA. The lack of available trained professional staff
dedicated entirely to the regional project will hinder the
effectiveness of this effort. T?ie coordination required
among water suppliers to proceed with the wellhead effort
provided lessons for the future.
The effectiveness of the wellhead delineation study
will depend largely on the regulations and implementation of
same by the three municipalities. There is a vast array of
municipal programs and regulations that could be adopted.
towards groundwater protection. Land use restrictions,
impervious surface limitations, storrnwater rnanagrnent, and a
coordinated review of projects are just a few examples of
programs that could be implemented on a regional basis. To
that end, coordination should be sought among trie
communities for consistency and for maximum protection.
Beyond the regulation level of protection, there are
additional programs that could be adopted that would serve
the goals of groundwater protection. Land acquisition,
monitoring programs, and the sewering of the. delineated
wellfield provide examples of joint programs that would
protect the public's investment in the drinking water
supply.
The goal of accornplisriing a regional wellhead
delineation study is close at hand. The delineation effort.
has been the tool for fostering regional cooperation and
interest in protecting the Hunt Aquifer. Unknown at this
time is whether the regional cooperation will continue
following the completion of the. wellhead delineation study.
It would seem that to fail to continue and participate in
joint programs would frustrate protection efforts. It would.
be easy to dismiss regional efforts by assigning the future
of the Hunt Aquifer to the municipalities who control the
land use. Protection efforts must include the involvement
of the water suppliers who have the capacity to provide
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leadership, program funding, and public policy initiative in furtherance
of drinking water supply protection.
References
-North Kingstown, Town of, and Town of East Greenwich. Petition for
Sole Source Aquifer Designation for the Hunt-Annaquatucket-
Pettaquamscutt Aquifer Region to the United States Environmental
Protection Agency, December 30, 1987-
-Rhode Island Statewide Planning Program, 1979, 208 Water Quality
Management Plan for Rhode Island: Final Plan, August, 1979:
Providence, Rhode Island 468 p.
-Rosenshein, J. S., J.B. Gonthier, and W.B. Allen, 1968,
Hydrologic characteristics and sustained yield of principal
ground-water units, Potowomut-Wickford area, Rhode Island:
U.S. Geologic Survey-Water Supply Paper 1775, 38p.
-United States Geological Survey, Wickford, Rhode Island quadrangle,
1975.
Special Note: The author wishes to express appreciation to Karen J.
Wilson, Rhode Island Coordinator, USEPA Office of Groundwater Protection
for her editing assistance in the preparation of this paper. Ms Wilson has
been a constant source of information and encouragement to the Town of
North Kingstown in our efforts at groundwater protection.
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MODEL FOR RURAL COMMUNITIES
TO ASSESS THREATS TO GROUND WATER QUALITY
Lynn Rubinstein, Land Use Planner
Franklin County Planning Department
425 Main Street, Greenfield, MA 01301
ABSTRACT
Rural communities which rely exclusively on private water supplies, and which
rely on volunteer town boards with no professional staff, often face more difficulty
in identifying threats to their ground water quality than do communities which have
access to professional assistance and public funding for protection of their water
supplies. The key reason for the frequent inability of rural communities to assess
the threats to their ground water is a lack of financial resources to hire
professionals to conduct the evaluation. What we learned through a year long effort
in the town of Conway, Massachusetts is that it is possible for a volunteer effort
to produce an in-depth and valuable ground water risk assessment.
This project was funded through the EPA 205J program and was designed to
conduct a ground water risk assessment in a rural setting, using only volunteer
effort and little or no funding. Conway was a guinea pig. The town's goal was a
ground water risk assessment; the 205J program goal was a model for conducting a
ground water risk assessment in a rural setting, with no public water supply, and no
hired consultants.
Conway is a rural hilltown community in Western Massachusetts with a population
of 1300 people and an area of 40 square miles. It relies entirely on private wells
for its drinking supply and has no professional staff supporting town government.
Businesses in town are primarily agriculture, a heavy equipment supplier, food
processing, and small scale auto repair. It is a community of well educated,
environmentally concerned citizens that are worried about the health and safety of
their water supply.
Included in the volunteer effort were a town wide survey, door-to-door
interviews, mapping, historic records review, geologic examination, public meetings
and presentations, and a final report and recommendations. The intent of the survey
was to locate all wells, septic systems, underground storage tanks, abandoned wells,
and land uses. The one-on-one interviews were critical for gathering information as
well as public outreach and participation. Existing documents were used for
identifying the geology and hydrology of the community.
After identifying their aquifers and potential threats to ground water quality,
final recommendations were developed for future action by the town. These
recommendations included a program of water quality testing and amendments to board
of health regulations and zoning.
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Without staff, money, or expertise, how is a rural community expected to find
out what threats may exist to the quality of its ground water? Why even bother to
delve into the question in the face of such obstacles? In Franklin County,
Massachusetts half of the towns rely exclusively on private wells for their water
supply. There are only three towns in the county which have any surface water
drinking supplies. Ground water quality is a pressing issue in such a setting, but
a lack of funding on the local or state level makes professional studies out of the
question, and thus the towns are left to wonder about what risks may exist to their
sole source of drinking water.
This is ironic because the threats to ground water quality in a rural setting
are usually a less complex and more controllable set of variables than exist in
urban settings. The key reason for the frequent inability of rural communities to
assess the threats to their ground water is a lack of financial resources to hire
professionals to conduct the evaluation. This model is designed to provide a basic
framework for a rural community to define threats to their ground water in the
absence of professional assistance.
What is a "threat to ground water?" As used here, ground water quality is at
risk if a land use presents the capacity to leach contaminants into a ground water
supply which is used for drinking water, and that the contaminants are of sufficient
quantity and type to present the potential for adverse health impacts. In other
words, contamination into ground water which is not used for drinking does not
present a threat because there would not be the potential for health consequences.
Similarly, just because a land use MAY contaminate ground water does not necessarily
mean that there is a threat to public health. The contamination may be in
quantities small enough that no adverse health consequences would result. In other
words, we are not determining that there is or will be contamination, but rather
that under the right circumstances there could be a problem.
Step One — Community Participation
Without the financial resources to hire a hydrologist, engineer, or other
qualified water professional, the town must rely on volunteer community efforts to
conduct the risk assessment. This is central to the success of the project.
Representation from all town boards is essential, as well as the highway
superintendent, the fire chief, and other concerned citizens.
While broad representation will help the process along, the most important
members of the risk assessment committee will be volunteers with backgrounds in
geology, planning, and engineering. Without some in-house expertise in geology and
ground water dynamics, the committees efforts will be significantly more difficult.
Often, local colleges and universities can provide students that may assist the
community effort in return for academic credit. In this way, the necessary
technical support can be supplied without significant financial commitment.
Once the committee is formed, a "leader" needs to be identified. Most likely,
it will be a representative from the board which was the catalyst for the ground
water risk assessment effort. It is also possible that this leader could be from
outside the community. Assistance may be able to be obtained from the Regional
Planning Agency, local colleges, or the local Conservation District. Leadership is
important to provide direction, coordinate efforts, and do such mundane chores as
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organize meetings, do mailings, and keep the community informed of the ongoing
efforts.
The committee should plan on meeting as a group at least once a month, with
substantive work being done between meetings. While this is a volunteer effort, it
will not be cost free. The town should appropriate enough money for the committee
to do a town-wide survey mailing, mail meeting reminders and press releases,
xeroxing, purchasing office supplies, mapping supplies, and copying of their report.
Ideally, there will also be funding for water quality testing. A budget of anywhere
from $1,000 to $5,000 could be sufficient.
Step Two — Collecting Existing Data
The town probably already has access to a surprising amount of information
concerning the town's geology, hydrology, water supplies, and risks to water
supplies. Once the committee is formed their first task will be to start collecting
this information. Their base goals will be to:
understand the geology of the town,
gather information on aquifer(s),
identify ground water research already done in the community,
locate and learn about wells in town,
locate underground storage tanks,
locate septic systems,
locate businesses which may present threats to ground water quality,
learn what town regulations and by-laws are already in place, and
identify town and state public works practices.
This information can be gathered from a variety of sources. Below is a list of
sources to consult for this information:
USGS Surficial Geology map for your town,
USGS Ground-Water Availability map,
USGS — ask whether there are any ground water or geology studies pertaining to
your community,
Soil Conservation Service (SCS) Soils Maps,
DEP Water Supply Atlas Sheet for the town,
Colleges and Universities -- check geology departments and college libraries
for theses addressing geology or ground water in the town,
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Contact consulting engineering firms in the area and ask whether they have any
information on ground water or geology in the community. If they do, they
may indicate who the work was done for and, therefore, who has possession of
the report,
Other towns — If the town is in the watershed or aquifer of a neighboring
community with a public water supply, that town may have pertinent
hydrogeologic information,
Town Hall — look for Open Space and Recreation Plan (the local Conservation
District will also have a copy of this),
Town Hall — the Board of Health should have records on all private wells
constructed in the past ten years. If the records are incomplete, the state
Department of Environmental Management (DEM), Water Resources Division, can
provide copies of the well logs. Well logs include information on the depth
of the well, type of construction, depth of water table, yield of well, and
materials passed through during construction,
Town Hall — the Board of Health should have records on all septic systems.
The DEP, Division of Water Pollution Control, may have copies as well,
Town Hall — the Town Clerk should have permits for all businesses in town,
Fire Department — The Fire Department should have permits for all underground
storage tanks in town,
Town Hall — Collect copies of all town by-laws, zoning by-laws, and Board of
Health regulations,
Local Highway Department — Interview about road salt application practices and
storage,
State Department of Public Works — If there are state roads in town, the same
questions should be asked of the state,
Town Right to Know Coordinator — May have information on businesses in town
which are using hazardous materials. DEP will have this information if it
is not available locally.
Town Hazardous Waste Coordinator — May have information on businesses in town
which produce hazardous waste. The DEP, Division of Hazardous Waste, also
has listings of registered generators of hazardous waste by community,
DEP — Water Pollution Control Division may have data on any streams in town
concerning water quality,
DEP — If the town abuts the Connecticut River, there is a study that was done
pertaining to pesticides and ground water contamination which may be of use,
Regional Planning Agency — May have information about the community use, or
may be able to indicate where else to look.
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Old Town Maps — can be important for historic land use information.
Interviewing senior members of the community and reading books on town
history can also be important for learning about past land uses which could
have left behind potential sources of contamination,
CCAMP Is a multi-agency ground water protection project which has produced
an excellent handbook on contamination sources for wellhead protection. It
includes detailed information on types of threats to ground water; including
descriptions of contaminants, their fate in soils and water, and description
of land use categories. Their matrix of land uses which present threats to
ground water quality is attached as appendix 2, and,
Massachusetts Audubon Society — Has an excellent series of flyers on
ground water protection, including basic information hydrogeology and town
strategies for protecting ground water resources.
Step Three — Filling in the Data Gaps
Despite the reams of valuable information which can be accumulated from the
sources listed above, it is unlikely that this process will have provided all of the
information needed to know about threats to a particular community's ground water.
At this juncture, a town-wide survey is very important. The goal of the survey is
to learn as much about specific sites as possible in order to determine what risks
to ground water quality which may exist. For example, the survey will try to
identify patterns of land use, relative siting of wells, underground storage tanks,
and septic systems, proximity to roads to wells, location of abandoned wells, and
more. In this way, a detailed picture of the town will begin to develop, as opposed
to the generally broader sweep of information provided by gathering existing data.
A sample survey is attached in appendix 1.
Conducting the survey will present several problems. In our experience there
is tremendous community resistance to providing information about private property
to anyone— especially the town. The fear is that the information will somehow "be
used against them." Because of this, it is important that there be adequate
publicity about the survey, the reasons for it, and assurances that the information
is not intended to be used as a basis for action against any individual. Assurances
should also appear on the survey itself.
The survey should be mailed to each address in town. Be sure to include town
owned buildings in the survey. Return postage should be provided, as well as a
convenient location in town for people to drop off their completed surveys. For
example, the library or town hall could have a box out to accept surveys. A name
and phone number for questions should be included on the survey. Publicity
containing reminders to complete the surveys, their importance, and, again,
assurances about their use as part of a study and not as a way of "checking up" on
people should be highlighted. A deadline for returning surveys should be included.
After about two months have gone by and less than the whole community has
responded, it is time to go door-to-door. This is hard work, but very important.
Speaking with individuals serves two important roles: 1) it helps diffuse community
suspicion and concern about what you are "up to," and 2) provides a more complete
survey response.
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On the other hand, door-to-door may not be a feasible approach. One possible
strategy would be to focus on certain key areas of town which are the most likely
sources of contaminants, and restrict the door-to-door canvasing to that area.
Also, if there is a similar pattern of development throughout town, then detailed
information town-wide may not be necessary. Or, it may be that there are two
distinct geologic settings in town and having a core of good data in each is
adequate to determine levels of potential threat to ground water. If you have
enough time and volunteer energy to cover the entire community, this is always
preferable, but obviously not always realistic.
While the surveys are circulating, committee members should start conducting a
windshield survey of the town to locate activities and businesses not previously
identified which may present risks to ground water. Interviewing the owners of
these facilities is a good idea. It helps to develop support for the risk
assessment process, and can provide important information. It also helps prevent
people from feeling that they are being singled out for attack. A listing of
enterprises which may present risks to ground water quality is attached in appendix
2.
What is going to be done with the town-wide and windshield survey results, and
well logs? Plot them on maps. This is not as difficult as it may sound. A good
"base map" will be necessary from which to work. USGS topographic maps are
excellent for this. If there are areas of dense development in town, the scale of
the USGS map will probably be too small. In this case, enlarging the base map to a
scale of perhaps 1:200 would help. This provides plenty of room for plotting of
detailed information. Using a town road map as the base map can also work quite
well. Again, changing the scale may make it more useable. The Regional Planning
Agency in your area can help to arrange the production of a base map and, if
necessary, can teach a member of the risk assessment committee how to plot the
information on the overlays. By using sheets of transparent mylar over the base map
layers of information can be developed.
Mapping all the information accumulated through the process described above
would be difficult and not necessarily helpful. Key pieces of information to plot
on the overlays are:
1) sand and gravel deposits identified on USGS surficial geology map,
2) locations and depths of private wells,
3) locations and identification of land uses which present threats to ground water
quality,
4) locations of underground storage tanks,
5) septic system locations,
6) wells within 100 ft. of a septic system, and
7) wells within 20 ft. of a roadway.
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These overlays are a critical first step in determining what threats to ground
water quality may exist in town. Through the use of the overlays it is possible to
begin to see the relationship between activities and wells, and can highlight areas
of critical concern in, a clear and simple way.
Step Four — Which Land Uses Constitute A Threat to Ground Water Quality?
Not all threats to ground water quality are of equal significance. Some land
uses, while appearing on a list of enterprises which present risks for ground water
contamination, present a low risk. This determination is based upon the type of
contaminants, how they interact with the environment, how they degrade in soil and
water, how fast they move, and how dangerous they are to human health. It is
important in the analysis of threats to ground water that the specific
characteristics of the community are taken into consideration. Many types of
activities will be identified on the attached lists which do not occur in a specific
town. Therefore, it is an important step is to identify which land uses with
potential risk to ground water do occur in a given community and to determine the
level of risk which they present according to the charts given in appendix I. In
addition, identifying any other types of activities that there is reason to be
concerned about which have not appeared on the list should be included.
Do not rely on the level of risk identified on the charts. For example, if
there is a textile dying enterprise in town it is considered to present a slight
risk to ground water. But, in a particular town the business has been illegally
dumping its waste for years, or has a failing septic system, or has five shallow
wells within thirty (30) feet of the site, or any other possible combination of
circumstances that could make this a potentially severe risk for this community.
Using common sense and knowledge of a specific setting to make determinations about
what constitutes a threat to ground water is the key to a complete ground water risk
assessment.
Step Five — Learning From What Has Been Collected
There should now be enough information gathered to critically assess the
potential for ground water contamination in town. It will be important to study the
geologic maps, location of sand and gravel deposits, clay layers, and depths of
wells to determine general patterns of ground water use in town. It is in this step
that the assistance of someone with geologic and hydrogeologic expertise is
critical. That person will be able to study the well logs, geologic maps, survey
results, and DEP and USGS studies to describe the hydrogeologic setting of the town.
Once this is understood the types of land use and risks that they may present can be
analyzed by using the attached charts in combination with a detailed understanding
of the specific site. For example, some land uses present great risks to shallow
wells, but may present little to no risk to bed rock/deep wells. There may also be
settings were septic system failures are more likely due to hydrogeologic settings,
and this can be analyzed by the expert in geology.
Once the hydrogeologic setting is defined and understood, the land uses can be
carefully examined to determine what risks they may present and to whom. For
example, the town may store its winter sand and salt pile out of doors. This may
present a ground water contamination threat to shallow wells in the vicinity. By
knowing that there are shallow wells nearby, rational judgements can be made about
water testing programs and appropriate town response to protect against
contamination.
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Step Six — Now What
By studying the proximity of various land uses with private wells, the depth of
those wells, and the degree of risk presented by the land use, decisions can be made
about what to do next. At this point it should be apparent what activities in town
may have already contaminated ground water, or which may in the future. If there is
reason to believe that ground water may already be contaminated, the community
should immediately implement a water quality testing program.
The water quality testing program should be designed to test for the
contaminants which are believed to be present. For example, if the study indicated
that septic system failure may have occurred in proximity to shallow wells, the
tests would be looking for nitrates and coliform contamination. If the threat is
presented by road salt, saline concentration would be highlighted. On the other
hand, perhaps the threat is seen to be from agriculture. It will be necessary to
identify the types of pesticides believed to have been used in order to test for
them in the ground water. An annual community water testing program will help
monitor long term and changing ground water conditions.
It is a good idea for the town to sponsor and pay for the water quality testing
program. First, it helps ensure community cooperation with the testing program.
Second, it ensures that copies of the test results come to the town. If the town
does not pay for the test, then homeowner permission for copies of the test results
to go to the town will have to be obtained. Third, by conducting a community
program, the cost can be negotiated down below that charged for individual tests.
If contamination is found, be sure to immediately notify DEP, Division of Water
Pollution Control. They can often provide technical support for solving or
remediating the situation.
Without water quality testing it will not be possible to know if there is an
existing problem with ground water quality. If there is a problem, it is important
to take remedial action to protect the health of the water users. If there is no
contamination, then it is important to take steps to ensure against future
contamination. Town regulations and by-laws, as well as public education can be key
in safeguarding future water quality. Examples of town regulations and by-laws
which can work to protect ground water quality include: aquifer protection zoning,
private well regulations, hazardous materials and underground storage tank
regulations, required septic tank pumping regulations, unregistered motor
vehicle by-laws, and, wetlands protection by-laws. The Regional Planning Agency
should be able to provide more information about these strategies. Other town
actions can include: covering of salt piles, decreasing use of road salt, land
acquisition and protection activities, town supported water quality testing, public
education efforts, hiring of professional health agent and planning staff, and,
cooperation in regional efforts to protect ground water.
Step Seven -- Finally
It is key that the results of the volunteer risk assessment be well publicized
and presented to the community. Public education and support for the effort are
essential if behavior is to be changed and town regulations and by-laws passed.
Copies of your report should be distributed around town and made generally
available. Be sure to send copies to the Regional Planning Agency and Conservation
District.
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Unless the town takes affirmative steps as a result of the study about threats
to ground water quality, it is inviting contamination to occur. Perhaps the most
important result of this study will be to educate the town officials about the
threats to public safety which exist in town and the actions which they can take to
protect the public.
APPENDICES
1. Sample survey.
2. Lists of Land Uses Which Present Risks to Ground Water.
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APPENDIX 1.
Sample Survey
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APPENDIX 1
SURVEY OF PRIVATE WELLS AND SEPTIC SYSTEMS
FOR GROUNDWATER RISK ASSESSMENT STUDY
The Town Boards are conducting a study to determine potential
threats to the quality of our drinking water. We need your help.
Please provide the information requested below to the best of your
ability. THIS INFORMATION WILL NOT BE USED BY ANY GOVERNMENTAL ENTITY
AS A BASIS FOR ACTION AGAINST YOU. IT IS SOLELY FOR RESEARCH PURPOSES.
In order to determine what could potentially harm your drinking
water, we need to know where your well is, your septic system, and
other land use features. In this way we will be able to accurately map
threats to ground water supplies, and just how close they are to
private drinking supplies.
Please take a few moments to draw a diagram of your property,
including: house, well, septic system, abandoned wells, underground
storage tanks, railroad tracks, power lines, and other structures. We
would also appreciate any information you have about your well: type,
depth, water table level, how far it is from the road, septic system,
and underground storage tanks. If you have a business on the site,
please describe the type of enterprise. If you have any questions,
please call , at .
Return postage has been provided. Please complete this form and
return no later than . Surveys can also be dropped off at the
library. Thank you very much for your assistance.
PLEASE DRAW RELATIVE LOCATIONS OF HOUSE, WELL, SEPTIC SYSTEM,
UNDERGROUND STORAGE TANK, HIGH POWER LINES, RAILROAD TRACKS, AND OTHER
STRUCTURES, AND SHOW DISTANCES BETWEEN (or guess at distances).
YOUR NAME:
STREET: ADDRESS:
PHONE NUMBER: 63
COMMENTS:
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APPENDIX 2.
Lists of Land Uses Which Present Risks to Ground Water.
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APPENDIX 2.
Lists of Land Uses Which Present Risks to Ground Water.
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GROONDWATER
RELATIVE LEVELS OF RISK
Taking into Consideration Volume, Likelihood of Release,
Toxicity of Contaminants, and Mobility
Compiled and Analyzed by Vermont Department of Health, 1988
SEVERE -
Dry Cleaners
Gas Station
Car Wash with Gas Station
Service Station — full or minor repairs
Painting and Rust Proofing
Junk Yards
Highway Deicing — application and storage
Right of Way Maintenance
Dust Inhibitors
Parking Lot Runoff
Commercial Size Fuel Tanks
Underground Storage Tanks
Injection Wells: automobile service station disposal wells;
industrial process water and waste disposal wells
Hazardous Waste Disposal
Land Fills
Salt Stock Piles
SEVERE TO MODERATE -
Machine Shops: metal working; electroplating; machining; etc
Chemical and Allied Products
Industrial Lagoons and Pits
Septic Tanks, Cesspools, and Privies
Septic Cleaners
Septage
Household Cleaning Supplies
Commercial Size Septic Systems
Chemical Stock Piles
Clandestine Dumping
MODERATE -
Carpet and Upholstery Cleaners
Printing and Publishing
Photography and X-Ray Labs
Funeral Homes
Pest Control
Oil Distributors
Paving and Roofing
Electrical Component Industry
Fertilizers and Pesticides
Paint Products
Automotive Products
Home Heating Oil Tanks Greenhouses and Nurseries
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Golf Courses
Landscaping
Above Ground Fuel Tanks
Agricultural Drainage Wells
Raw Sewage Disposal Wells Abandoned Drinking Wells
MODERATE TO SLIGHT -
Water Softeners
Research Laboratories
Above Ground Manure Tanks
Storm Water and Industrial Drainage Wells " --
Stump Dumps
Construction
SLIGHT -
Beauty Salons
Car Wash
Taxidermists
Dying/Finishing of Textiles
Paper and Allied Products
Tanneries
Rubber and Misc. Plastic Products
Stone, Class, Clay, and Concrete Products
Soft Drink Bottlers
Animal Feedlots, Stables, and Kennels
Animal Burial
Dairy Waste
Poultry and Egg Processing
Railroad Tracks, Yards, and Maintenance Stations
Electrical Power Generation Plants, and Powerline Corridors
Mining of Domestic Stone
Meat Packing, Rendering, and Poultry Plants
Open Burning and Detonation Sites
Aquifer Recharge Wells
Electric Power and Direct Heat Reinjection Wells
Domestic Wastewater Treatment Plant and Effluent Disposal
Wells
Radioactive Waste
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LAND USE/PUBLIC-SUPPLY WELL POLLUTION POTENTIAL MATRIX
Land U*« Consideration*
Potential
Contaminant*
Ovar*J] Thual lo Public Health
Mot-lily
ttaluial B>ckground
L-M
M
M
I.M
L
L
«
ifW;
U
H
^
L
M
fe.
H
L H
^
H
t
L
H
LM
M
M
L.H
m
H
&!§$
&S«sj3
lEpgBpra
H
"
Pi
H
Overall Threat
Land Us. Cai.gorl.m » Pub»« W»*«' Supply*
re Stripping and Pa ml ing
Industrial Lagoons and Pill
Jvwelry and Maul Plal.ng
Machine Shopi/Metal Wwkirv
RaMaich L»bt/Umv«riili«i/Hoipiial*
Road ind Miiniamnce Oepoli
« Lagoon* and S1udg«
Sepix; Srtltmi. C«»pooti and W.lei
The contaminants) released from this land-use category
accordance with federal and state maximum contaminant
may render groundwater at a public-supply well undrinkable in
it levels.
L
This land use category is not generally associated with the release of the particular contaminant in quantities that would
render the groundwater at a public-supply well undrinkable. However, the contaminant may be associated with a particular
activity.
• Low Threat
M = Medium Threat
H = High Threat
This Matrix is based on a literature review and the combined field experience of the Cape Cod Aquifer Management Project (CCAMP) '
THISMATRIXSHOULDBEUSEDASAGUIDEANDHANDYREFERENCE.Itisnotasubstituteforlookingatapanicularlanduse
in detail. There will always be the potential for a business to use an unusual process using chemicals not normally associated with that
business. The land-use categories included in the Matrix and Guide to Contamination Sources for Wellhead Protection are those that
might be found in the primary recharge area of a public-supply well in Massachusetts. This Matrix may be misleading or erroneous if
applied to low-yield private wells.
I. Niuaie has a cumulative Impact on 9rOUndW8tef quality No one caiegorv is responsible lor the releau&f nitrate. A variety of land use categories release nitrate These
mclude an.mal leedlots, landl.lls. sopi.c sysiems, sepiage lagoons, municipal waElew3ler end agrlcullurai activities including rurf maintenance
There are no known insianc
groundwaier from this land u
o fiuirir 1f> Confnmin
mintenance
ol beeuly parlors contaminating well waler in Massachusetts More research is needed to determine the severity of a threat to
s fn, Wullhnad Pro
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BIOGRAPHICAL SKETCH
Lynn Rubinstein, Land Use Planner
425 Main Street
Greenfield, MA 01301
Lynn Rubinstein is the Franklin County Land Use Planner, specializing in ground
water, hazardous waste, and rural preservation. She is a member of the Massachusetts
Hazardous Waste Advisory Committee, and a member of the Board of Directors of the
Valley Land Fund, Inc. Previously, she was the Coordinator of the Franklin, Hampden,
and Hampshire Conservation Districts. Before moving to Massachusetts, Ms. Rubinstein
was a trial attorney with the Department of Justice. She has a B.A. from Wesleyan
University in geology. Publications include: "What Choices Do You Have Besides
Selling Your Farmland For Development?," "Forest and Farm Land Preservation
Techniques,: and "Affordable Limited Development: A Model for Housing in Rural
Communities."
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70
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THE FOX(BOROUGH) GUARDING
THE AQUIFER COOP:
LOCAL CONTROL AT WORK
Kimberly D. Noake, Project Hydrogeologlst
SEA Consultants Inc.
485 Massachusetts Avenue
Cambridge, Massachusetts 02139
Abstract
Both the elected officials and citizens of the Town of Foxborough, Massachusetts have
made a serious commitment to groundwater quality protection and management of potential
contamination sources. Foxborough's wellhead protection strategy is not a product of
a federal or state mandated program, rather, it evolved over a five year period in
response to local needs.
Due to the nature of the groundwater resource, it must be identified and protected at
the local level. Unlike hazardous waste and leaking underground storage tanks which
can be regulated by federal or state legislation regardless of location, occurrence,
or quantity, the identification of aquifers and the development of wellhead protection
strategies is a site-specific process.
The delineation of a wellhead protection area depends upon the hydrogeologic
characteristics of the aquifer, the pumping rate and number of wells, and the amount
of recharge the aquifer receives from precipitation and induced infiltration from
surface water bodies. In Massachusetts, for example, a wellhead protection area in
a buried river valley aquifer will have a different configuration than one in a glacial
outwash plain aquifer. Foxborough recognized the importance of local resource-based
groundwater protection five years ago when it delineated its wellhead protection areas
and adopted a Water Resource Protection District bylaw in 1984.
Recently, over 40 Massachusetts communities have lost major municipal groundwater
supplies to contamination or have experienced severe water shortages. The plight of
neighboring communities prompted Foxborough officials to engage SEA Consultants Inc.
to update the 1984 bylaw and redefine the wellhead protection areas to conform with
recently adopted state guidelines for delineating primary (Zone II) and secondary (Zone
III) aquifer recharge areas. The goal of the town was to have a technically defensible
wellhead protection strategy.
Several carefully tailored approaches were used to delineate the Zone II and Zone III
areas for Foxborough's 11 existing wells and 6 proven well sites. Monitoring wells
were installed and performance tests conducted at each of the town's pumping stations
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using an automated data gathering and processing system. This data logger supplied
aquifer property data collected under uniform ambient conditions for use in a detailed
town-wide aquifer simulation model which delineated the Zone II and Zone III areas for
the 17 wells. Existing pumping test data was re-evaluated using current computer
programs and incorporated into the town-wide model where necessary.
A mass balance analytical nitrate loading model was also used to determine the nitrate
loading in the Zone II areas under maximum build-out conditions. A new Water Resource
Protection District bylaw was written to protect both the Zone II and Zone III areas.
The bylaw includes a comprehensive list of prohibited uses and uses allowed by special
permit that are subject to stringent performance standards. Minimum lot sizes for
various uses were also included to ensure that nitrate concentrations at the wellhead
do not exceed drinking water standards. To further strengthen the town's wellhead
protection strategy, SEA wrote a new Toxic and Hazardous Materials bylaw, recommended
changes to subdivision rules and Board of Health regulations, and designed a
groundwater monitoring program.
Introduction
Over forty municipalities in Massachusetts have lost all or part of their municipal
groundwater supplies to chemical and bacterial contamination due to the siting of
inappropriate land uses in the primary recharge areas of their public supply wells.
All across the state, increasing development pressures threaten the supply of clean,
abundant water; the very resource that enables the economy of a town to flourish.
The primary responsibility for groundwater protection lies not with the federal and
state governments but with local boards and citizens. Although the tracking and
disposal of hazardous waste and leaking underground storage tanks are managed by
federal and state legislation, many other point and nonpoint potential contamination
sources are more effectively controlled by municipal regulations.
The federal Wellhead Protection Program, authorized by the Safe Drinking Water Act
Amendments of 1986, authorized Congress to distribute grants and technical assistance
to states that develop wellhead protection programs. Massachusetts recently submitted
a wellhead protection program to meet federal guidelines. Existing programs at the
state level offer grants for land acquisition in sensitive recharge areas and technical
assistance in delineating wellhead protection areas and drafting protective
legislation. The philosophy at both the state and federal level is that wellhead
protection strategies should be resource-based and thus are inextricably linked to
municipal governments.
Comprehensive local groundwater protection strategies begin with an accurate,
scientifically-based delineation of primary and secondary aquifer recharge areas.
Historically, the use of land in the vicinity of public supply wells, excluding the
400 foot protective radius required by the state, was not stringently controlled. This
occurred for two reasons: (1) the threats to the groundwater resource were not
completely understood, and (2) the aquifers and well recharge areas were not accurately
delineated. Now, however, several tools are available to communities to enable them
to identify, define, and protect existing and potential groundwater supplies,
including: sophisticated three-dimensional numerical computer models that simulate
groundwater flow; innovative zoning and general bylaws; subdivision regulations; and
Board of Health regulations. Conscious land use decisions must be made by citizens
and local boards in order to protect groundwater supplies from contamination. An
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Town Location Map
Foxborough, Massachusetts
73
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exceptional example of a town that has taken substantial steps toward developing a
comprehensive groundwater protection strategy is Foxborough, Massachusetts.
The Town of Foxborough, Massachusetts is located in Norfolk County, approximately 25
miles southwest of Boston. The town comprises approximately 21 square miles and its
entire population of over 15,000 people is served by groundwater from 11 wells. The
wells are between 30 and 40 feet deep and are screened in the unconsolidated glacial
deposits of four buried river valley aquifers. These four aquifers, the Wading River
Aquifer, Neponset Reservoir Aquifer, Billings Brook/Rumford River Aquifer, and the
Canoe River Aquifer, derive a significant amount of recharge by induced infiltration
from nearby surface water bodies. The combined safe yield of the town's 11 wells is
approximately four (4) million gallons per day. Foxborough also has six proven well
sites that will supplement the current system when needed.
Hydrogeology
Foxborough is located in the Eastern Plateau physiographic province of Massachusetts.
In this area, the bedrock forms a flat, well-dissected plateau that gently slopes to
the east. According to the U.S. Geological Survey Bedrock Geologic Map of
Massachusetts (Zen, et al. , 1983), four northeast/southwest trending bedrock units
underlie Foxborough. They are, in order of occurrence from north to south, the Sharon
Syenite, the Dedham Granite, the Wamsutta Formation, and the Rhode Island Formation.
During the Pleistocene Epoch, New England was glaciated several times. The glacier
plucked and scoured the bedrock, entraining sediments that ranged in size from huge
boulders (glacial erratics) to cobbles, pebbles, sand, silt, clay and rock flour.
As the glacier advanced and retreated, it deposited some of its entrained debris,
called till, directly on the ground. Till is a poorly sorted, heterogeneous mixture
of sand, silt, clay and angular rocks of various sizes. The glacier smeared till over
bedrock knobs and along the walls of bedrock valleys and deposited it in elongated till
hills (drumlins) . In some cases, till flowed or slumped off the surface of the melting
ice. This "flow till" can sometimes be observed within sand and gravel deposits.
Over time, the climate changed and the earth experienced a gradual warming trend that
continues to this day. As a result, the glacial ice began to melt. Along the
irregular margin of wasting ice, meltwater streams poured from subglacial tunnels or
through valleys carved in the ice. In the openings between the wasting ice and
till-covered bedrock knobs, these streams sorted and deposited sediments in their
channels (glaciofluvial deposits) as well as in ice-marginal lakes and ponds
(glaciolacustrine deposits). These unconsolidated deposits are called stratified
drift.
Meltwater streams transported, sorted and deposited glacially entrained sediments
according to grain size. High velocity meltwater streams deposited cobbles, gravel,
sand and minor amounts of silt and clay in major outwash plains and valley trains.
The bulk of the fine grained sediments (silt and clay) was held in suspension and
eventually deposited by slow flowing streams in glacial lakes. In Foxborough, the
glacial meltwater streams filled the ancient north/south trending bedrock valleys with
varying thicknesses of interbedded gravel, sand, silt and clay. Thus, the Town's
buried river valley aquifers were created.
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Aquifer Delineation and Mapping
In order to identify the extent of Foxborough's aquifers, locate sites favorable for
future groundwater exploration and designate groundwater protection areas, it was
necessary to delineate areas underlain predominantly by coarse-grained stratified
drift. Unfortunately, detailed surficial geologic maps were not available for Fox-
borough. In the absence of such maps, soil survey maps provided much useful infor-
mation. Although soils maps are a reflection of only the top two to three feet of
soil, this top layer is generally indicative of subsurface materials. Soil maps and
an Interim Soil Survey Report for Norfolk and Suffolk Counties are available for
Foxborough from the U.S. Department of Agriculture, Soil Conservation Service. Certain
soils, such as those of the Charlton-Hollis Association, are typical of glacial till.
Because till does not readily transmit water, areas underlain by glacial till soils
are considered to be non-aquifer areas. Other types of soils are more typical of
stratified drift, which are more uniform sands and gravels generally capable of
transmitting large quantities of water. Areas underlain by stratified drift-derived
soils such as the Hinckley or Merrimac series are considered to be aquifer areas.
Topographic features were also used in mapping glacial deposits. Flat-topped terraces
surrounded by steep slopes are typical of stratified drift, for example, whereas
uniform slopes are generally characteristic of glacial till. Field verification was
an important adjunct to reconnaissance mapping based upon topography and soils.
Bedrock outcrops were noted, as were natural exposures of soil and man-made
excavations. The "micro-topography" of the land, the number, size, and shape of
boulders, drainage, and other factors were also utilized in mapping surficial deposits.
Well and boring data from over 300 locations in Foxborough were also used to delineate
the unconsolidated aquifers (see Plate 1). The surficial geologic units shown on Plate
2 are divided into the two distinct types already discussed: glacial till and strati-
fied drift. The limits of the non-aquifer glacial till areas are delineated on Plate
2 by the diagonal hatched areas and are labeled as "Qt"- The limits of the remaining
aquifer areas, the stratified drift deposits, are labeled as "Qsg".
Aquifer Saturated Thickness
Within the stratified drift aquifer areas shown on Plate 2, the characteristics of the
aquifer were further evaluated by determining the aquifer saturated thickness. The
saturated thickness, or vertical thickness of the aquifer, is a measure of the size
of the groundwater reservoir. The aquifer saturated thickness is calculated from
boring and well log data by subtracting the top of aquifer (water table surface) from
the bottom of aquifer (till or bedrock surface). Areas of highest saturated thickness
(over 30 feet) are generally the most favorable for high yield well development.
The Wading River Aquifer is the most extensive aquifer in Foxborough, with a saturated
thickness exceeding 50 feet in the vicinity of Lake Mirimichi. The Neponset Reservoir
Aquifer appears, based upon existing data, to have a high favorability area limited
to a northeast-southwest trending trough extending from the H.C. Morse proposed well
site to the Foxboro Company. The vertical extent of the groundwater aquifer at Well
Pumping Station No. 4, off of Route 1, is also limited in extent.
The northern portion of the Billings Brook/Rumford River Aquifer in Foxborough has been
extensively explored and developed and is considered to be close to its safe yield.
SEA recommended no further well development beyond the existing and proven well
sites. There is, however, the potential for future well development in the southern
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SUBSURFACE DATA POINTS MAP
SURFACE WATERSHED BOUNDARY
EXISTING PUMPING STATION
FUTURE PROVEN WELL SITES
TOWN LINE
• TEST BORINGS (NUMBER-YEAR)
'-• SEISMIC PROFILES
TOWN-WIDE GROUNDWATER
PROTECTION STUDY
FOXBOROUGH, MASSACHUSETTS
SEA Consultants Inc.
Engineers/Architects
2000 1000 0 2000 4000
SCAI F IN FFFT
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SURFICIAl GEOLOGY AND
AQUIFER SATURATED THICKNESS
MAP
TOWN-WIDE GROUNDWATER
PROTECTION STUDY
FOXBOROUGH, MASSACHUSETTS
SE A Consultants Inc
Engineers/Architects
77
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portion of the Rumford River Aquifer south of Route 140 (Cocasset Street) and east of
Morse Street. The Canoe River Aquifer is the only known aquifer in Town which is not
currently being utilized as a source of water supply. SEA recommended additional
exploration in this aquifer east of East Street and southwest of Beaumont Pond to
better define the favorability of this aquifer.
Aquifer Transmissivity
In addition to the aquifer saturated thickness map, a map of Aquifer Transmissivity
(Plate 3) was prepared. Aquifer transmissivity is a better indicator of potential well
yields than saturated thickness alone. Aquifer transmissivity is equal to the
saturated thickness of the aquifer multiplied by the hydraulic conductivity
(permeability).
Hydraulic conductivity is a quantitative description of the water-transmitting
characteristics of the soil materials comprising the aquifer. It is defined as the
volume of water at the existing kinematic viscosity (field conditions) which will move
in unit time under a unit hydraulic gradient through a unit area normal to the
direction of flow. For this study, the pumping test analyses and previous reports
describing the aquifer in terms of geology and hydraulic conductivity were reviewed.
Available pumping tests were evaluated using computer pumping test analysis programs
(Hall Groundwater Consultants, Inc. , 1986) for time versus drawdown and distance versus
drawdown. The transmissivity of individual test well locations was also calculated
using the boring log descriptions and assigning average hydraulic conductivities to
the various grain size distributions (sand, gravel, silt, clay) which were reported.
Field Exploration Program and Prolonged Pumping Tests
SEA designed a field exploration program and conducted four pumping tests to expand
the aquifer property data base and calibrate the zone of contribution groundwater flow
model. Based upon the data compilation and review, and the aquifer hydrogeologic maps,
specific areas were identified adjacent to the existing pumping stations where
additional data was needed to determine aquifer stratigraphy and the following
properties: saturated thickness, hydraulic conductivity, transmissivity and
storativity. Following site inspections at each pumping station, a field exploration
program was designed consisting of observation well installation, water table elevation
surveying, and completion of a prolonged pump test.
A total of 13 new observation wells were constructed using the drive-and-wash method.
The wells consist of 2.5 inch steel casing with five feet of screen set at either the
bottom of aquifer (deep wells) or just below the surface organic sediment deposits
(shallow wells). Clustered wells, consisting of a shallow and deep well at the same
location, were utilized at Stations No. 1, No. 2 and No. 4 to evaluate the induced
infiltration from adjacent surface water bodies and allow for a more accurate
calculation of aquifer properties.
Four pumping tests were conducted at each of the four existing pumping station
locations (Nos. 1-4) during January 1989. The 13 new observation wells and 10 existing
observation wells were used to monitor water table drawdown in the vicinity of each
pumping station. Each pumping station was shut down for a minimum of two days prior
to commencing the three day pump test to allow the water table to recover to (or close
to) its static elevation. The pumping test itself was conducted for approximately
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AQUIFER TRANSMISSIVITY MAP
TOWN-WIDE GROUNDWATER
PROTECTION STUDY
FOXBOROUGH, MASSACHUSETTS
SEA Consultants Inc.
Engineers/Architects
79
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three days followed by two days of recovery readings. The actual duration of well
shutdown prior to the test, length of the pump test, and recovery, after the test, were
performed as the normal operation of the water supply distribution system allowed.
In order to obtain water level measurements simultaneously from four observation wells
during the pump tests, an automated computer storage and retrieval system consisting
of pressure transducers linked to a data logger was used for both the pumping and
recovery phases of the test.
Water level sampling interval times were programmed into the data logger to correspond
to the Massachusetts Department of Environmental Protection Water Supply guidelines
(DEP, 1989): 10 readings taken at six second intervals, followed by 10 readings taken
at one minute intervals, followed by 10 readings taken at ten minute intervals,
followed by one reading taken each hour for the duration of the pump test. Recovery
sampling intervals were identical to the pump test drawdown intervals.
Zone of Contribution Modeling
A three-dimensional finite difference groundwater flow model was used to delineate the
zone of contribution recharge areas for Foxborough's 11 existing wells and 6 proven
future well sites. SEA chose the U.S. Geological Survey's MODFLOW computer model
(McDonald and Harbaugh, 1984) to simulate groundwater flow in the heterogeneous aquifer
system. MODFLOW simulates groundwater flow in both steady state and transient
conditions. The program code for the Foxborough model was adapted to run on a Digital
Microvax II computer which allowed the simulation of anisotropic, nonhomogeneous
aquifers under varying pumping scenarios. In Foxborough, induced infiltration from
surface waters provides a significant amount of recharge to the public supply wells.
Therefore, the model also simulated the exchange of water between surface waters and
groundwater.
The primary objective of the numerical computer model was to provide a sound technical
basis for delineating water supply protection zones in accordance with Massachusetts
Department of Environmental Protection (DEP) definitions, which are given below:
Zone I: The 400-foot wellhead radius designated by DEP for the protection of the
supply which is owned or controlled by the water supplier.
Zone II: The area of an aquifer which contributes water to a well under the most
severe recharge and pumping conditions that can be realistically anticipated (180 days
with no recharge and continuous pumping at the maximum rated "safe yield" capacities
of the pumping stations). It is bounded by the groundwater divides which result from
pumping the well(s), and by the contact of 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: That land area beyond the area of Zone II from which surface water and
groundwater drain into Zone II. The surface drainage area as determined by topography
is commonly coincident with the groundwater drainage area and will be used to delineate
Zone III. In some locations, where surface and groundwater drainage are not
coincident, Zone III shall consist of both the surface drainage and the groundwater
drainage areas.
Zone I is defined here for the sake of completeness; all land within Zone I is
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currently owned by the Town of Foxborough. Zone II is the primary zone of interest
in this investigation, and the aquifer modeling discussed below was performed
specifically to meet the requirements of defining Zone II. Zone III is integrally
connected to Zone II via surface runoff and surface water bodies which form recharge
boundaries .
Mathematical Model
MODFLOW's aquifer simulation program calculates the hydraulic head in an aquifer under
various recharge and pumping conditions. This is achieved by solving the following
partial differential equation governing the two-dimensional flow of groundwater in an
aquifer :
= S
Where: T - transmissivity of the aquifer
h — head
x,y - rectangular coordinates
S - storage coefficient of the aquifer
t - time
Q — net groundwater withdrawal/recharge rate per unit surface
area
MODFLOW calculates the solution to this equation by solving each node equation of a
column of the model while all the terms in the other columns are held constant. Column
by column and then row by row, the process continues until a convergence is achieved.
Aquifer Hydraulic Properties
The hydraulic properties of the aquifers, including recharge, hydraulic conductivity,
storativity, initial water table elevation, and bottom of aquifer elevation were
entered into MODFLOW by superimposing a variable spaced grid system over maps of the
aquifer properties and then interpolating values at each grid node. Plate 4
illustrates the finite difference grid which was developed to assemble the model data
base. The variably spaced grid consists of a 91 column by 96 row grid superimposed
over the entire Town of Foxborough and the upgradient Billings Brook Aquifer in the
neighboring Town of Sharon. Grid size ranges in size from 200 by 200 feet to 800 by
800 feet. The smallest grid spacing was used over existing and proven well sites to
provide greater resolution and calibration of the model in areas where water table
drawdown during pumping is greatest. Output from the model consists of calculated
water table elevations at each node .
The estimated average annual recharge to the aquifer within the study area from
rainfall and snowmelt, based on U.S. Geological Survey Hydrologic Atlas data and
rainfall data, was assumed to be 15 inches per year for stratified drift aquifer areas
and 6 inches per year for glacial till (nonaquifer) areas.
Hydraulic conductivity at individual nodes within the stratified drift areas was
calculated from pumping tests and boring logs. Each hydraulic conductivity value was
plotted onto the base map and interpolated between data points to define the value at
each node. A value of 1 foot per day was used for all nodes within the glacial till
areas .
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FINITE DIFFERENCE GRID
WITH SURFACE WATER BODIES
TOWN-WIDE GRDUNDWATER
PROTECTION STUDY
FDXBDROUGH MASSACHUSETTS
SEA Consultants Inc
Engineers/Architects
PLATE 4
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The Initial, non-pumping water table elevation was determined using surveyed water
levels from prolonged pumping tests, evaluation of static water levels recorded on
boring logs, and interpretation of surface water elevations from the topographic base
map. Plate 5 is a map illustrating the simulated steady state, or long-term average,
water table elevation.
The aquifer bottom, or bedrock, elevation was calculated by subtracting the saturated
thickness value for each node from the water table elevation for each node. The
surficial geologic map and field investigations were also incorporated into the bedrock
elevation data base.
The storativity (or storage coefficient) of an aquifer is defined as the volume of
water released from or taken into storage per unit surface area of the aquifer per unit
change in the component of hydraulic head normal to that surface. For unconfined
aquifers, like those in Foxborough, the principal source of water is from gravity
drainage, the volume of water derived from expansion of the water and compression of
the aquifer being negligible. Thus, in the case of unconfined aquifers, the
storativity is virtually equal to the specific yield. The specific yield of an aquifer
is defined as the ratio of the volume of water which the saturated portion of an
aquifer will yield by gravity drainage to the volume which is subject to such drainage.
Storativity values were calculated from available pumping tests by the following
formula:
S - 0.3 Tt
Where S — Storativity (dimensionless)
T - Transmissivity (gpd/ft)
t - Time since pumping started (days)
r0 - Intercept at zero drawdown of extended straight line
of distance-drawdown graph (feet)
The calculated storativity values range from 0.03 to 0.50 indicating unconfined aquifer
conditions and, at the higher end of the range, significant amounts, of induced
infiltration from surface waters. Storativity values were also calculated by comparing
soil logs to values reported in the literature for specific yield. These analyses
suggest that a value of 0.20 for Foxborough's sand and gravel aquifers is appropriate.
Storativity was considered to be a constant throughout the modeled stratified drift
aquifer area.
Boundary Conditions
The numerical simulation model extends beyond the Foxborough town line and includes
the entire upgradient watershed area for each aquifer and, most importantly, the Town
of Sharon wells which are within the Billings Brook Aquifer. The surface watershed
boundaries along the edge of the model were simulated as no-flow boundaries. This was
necessary in order to depict the physical system as accurately as possible. The
southern limits of the model, south of the Foxborough.town line, were simulated as
constant head boundaries; the water table elevation was held constant. The direction
of groundwater flow along the southern town line is to the south, or out of town.
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LEGEND
SUk; -
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Thus, the constant head water table elevations along this boundary are lower than
elsewhere in town and the model effectively "drains" water out of the aquifer in this
area.
The MODFLOW "river package" was used to simulate the significant effect that surface
water bodies (streams, rivers, ponds, wetlands and lakes) have on recharging the
groundwater aquifer when the wells are being pumped. Plate 4 illustrates the nodes
which were designated as induced infiltration, or river nodes. The surface water
elevations at each river node were set equal to the input static water table elevation.
Bottom sediment hydraulic conductivities were varied from 0.7 ft/day to 2.0 ft/day
depending upon the substrate observed along the individual induced infiltration areas
during the field investigations.
Model Calibration
The purpose of model calibration is to confirm that the model simulates observed field
conditions. The initial step of model calibration involved development of a steady
state static water table map. The final calibration procedure involved comparing
computer-generated water table elevations and drawdowns with those measured during the
field pumping tests.
Contouring of the static water table was initially performed manually and was then
supplemented by water levels measured during the four pump tests. The static steady
state water table map generated by the computer simulation model as a result of the
boundary conditions, starting head distribution, aquifer properties, and recharge
values discussed above is presented as Plate 5. Comparison of the two maps provided
documented verification of the reliability of the model to accurately represent the
behavior of the actual system under the given conditions.
Water table contours illustrating groundwater discharge into the surface drainage
system are evident in both the regional contouring and the model runs. The water table
contours from the program runs, however, do not have the sharp distinction of the
manually prepared map. This dampening of groundwater contours occurs because the
surface water is modeled as a node-centered system, and is averaged over the entire
grid area. The effect of the rivers cannot be modeled as sharply as actual field
conditions would indicate. However, the overall correspondence between the observed
field conditions and the model-generated contours is quite good with simulated water
levels being within one to two feet of the surveyed water levels and water levels
indicated on the topographic base for the various ponds and streams. Comparison of
drawdowns observed during the pump tests performed by SEA and simulated by the model
for the same duration and pumping rate were also quite good with a residual difference
of one foot or less.
Delineation of Water Resource Protection Zones
Following calibration, MODFLOW was used to simulate the worst-case Zone II scenario
by pumping all existing and proven future wells at their maximum-rated capacities for
180 days with no recharge to the aquifers. This simulation included the Town of
Sharon's existing and proven wells within the Billings Brook Aquifer upgradient of
Foxborough's Station No. 3 and No. 3A. The pumping rates used in the Zone II
simulation are listed in Table 1.1.
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Table 1.1
Well Pumping Rates for Zone II Simulation
Well No.
Sta. #1, Well #1
Well #2A
Sta. #2, Well #4
Well #5
Well #6
Sta. #3,
Well #8
Well #9
Sta.
Sta.
Well #7
#3A, Well #10
#4, Well #12
Sharon
Lamson Road #71
Mill Street #74
Witch Pond #3-87
Witch Pond #1
H.C. Morse #4
West Street #16
Sta. #5
Sta. #7
Wolomolopoag Pond
Pumping Rate
400
350
400
400
400
250
150
400
500
325
350
300
500
700
350
500
300
350
280
Plate 6 is a map of the Simulated Water Table Drawdown for Zone II Conditions and
illustrates water table drawdown after 180 days of pumping with no recharge. Water
table drawdown was calculated by subtracting the water table elevations simulated after
180 days of pumping with no recharge from a second simulation performed for 180 days
with no recharge and no pumping. The difference between the two simulations is the
water table drawdown due solely from well pumping.
The groundwater divides resulting from pumping form the downgradient limits of Zone
II for both the Witch Pond proposed wells and the Billings Brook/Rumford River wells
(Station No. 3 and 3A). The lateral limits of Zone II are the contacts between the
stratified drift aquifer deposits and the glacial till (Zone III) deposits. The
upgradient limits of Zone II were delineated by extending the simulated water table
drawdowns upgradient to the prevailing hydrogeologic boundary, which for the three Zone
II areas, is the groundwater divide forming the limit of the sand and gravel aquifer.
Following the delineation of Zone II, the Zone III areas were determined by delineating
the surface watersheds which contribute recharge into Zone II. Plate 7 is a map of
the Water Resource Protection District calculated for Foxborough's aquifers and
illustrates the extent of the Zone II and Zone III areas.
Future Potential Aquifer Areas were also delineated on Plate 7 and are included within
the Water Resource Protection District. These areas, including the Canoe River Aquifer
and the southern portion of the Rumford River Aquifer, were delineated to include the
stratified drift aquifer deposits with a saturated thickness greater than 10 feet.
These areas may, upon further test well exploration, prove suitable for the development
of high-yield water supply wells.
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SIMULATED WATER TABLE
DRAWDOWN FDR ZONE II
CONDITIONS
C.'JP'r A.CF WATERSHED BOUNDARY
Fx;;,rING PUMPING STATION
FUTURF: PPDVLN WELL SITES
T[;VN LINE
SIMULATED WATER TABLE 3RAVDUVNS
TOWN-WIDE GROUNDWATER
PROTECTION STUDY
FDXBORDUGK MASSACHUSETTS
SEA Consultants Inc.
Engineers/Architects
APRIL 1989
2noo 1000 o 2000 4000
SCALE IN FEET
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WATER RESOURCE
PROTECTION DISTRICT
SURFACE WATERSHED BOUNDARY
EXISTING PUMPING STATION
FUTURE HROVEN V/ELL SITES
TOWN UNE
0 ;ONF. II
' ZONE III
FUTURE AQUIFER AREAS
TOWN-WIDE GROUNDWATER
PROTECTION STUDY
FOXBOROUGH.^MASSACHUSETTS
SEA Consultants Inc
Engineers/Architects
APRIL 1989
2000 1000 0 2000
F IN FFFT
88
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Potential Sources of Contamination
Foxborough is a relatively urbanized town that contains single and multi-family
residential developments and typical service-oriented commercial businesses. The
Foxboro Company, which has several locations throughout the town, is Foxborough's
primary industrial business.
Stratified drift aquifers are highly susceptible to contamination by a wide variety
of land uses. Contaminants may enter the groundwater as leachate from historic
industrial sites and associated waste disposal areas, illegal dumping sites, accidental
spills, or agricultural areas. However, contamination is much more commonly associated
with heavily developed commercial or industrial areas, solid waste landfills,
industrial and commercial wastewater disposal, septic system effluent, and septage
disposal facilities.
Working with town officials, SEA targeted for investigation three categories of
potential contamination sources, underground storage tanks and the storage of toxic
and hazardous materials, road salt storage and application, and septic system effluent.
Best Management Practices (BMPs) designed to mitigate the threat to groundwater quality
posed by these potential contamination sources appear in the bylaws, revised
regulations, and recommendations prepared by S E A.
Underground Storage Tanks and Toxic and Hazardous Materials Storage
Most commercial and industrial facilities store fuel and/or hazardous materials in
underground storage tank systems, above ground tanks or drums. Accidents involving
these storage facilities can and will occur. In the absence of an adequate containment
structure for drums or above ground tank storage areas, secondary containment for
underground storage tanks (including piping), and a spill response contingency plan,
spills or leaks from these facilities pose a serious threat to groundwater quality.
Underground storage tank systems (USTs) are also a serious threat to groundwater
quality. Many types of commercial and industrial facilities store gasoline, diesel
fuel, waste oil, heating oil, solvents and other hazardous materials in USTs. Highway
departments, trucking companies, and service stations may have several different tanks
of varying capacities for the storage of gasoline, diesel fuel and waste oil.
Municipal facilities and public or private institutions such as hospitals, schools,
libraries, and households store heating oil in USTs.
In Foxborough, tank capacity for USTs varies from 275 gallons to 50,000 gallons. Each
underground tank is a potential threat to local public water supplies. Defects in tank
materials, improper installation, corrosion or mechanical failure of the pipes and
fittings may result in leaking USTs. Most early underground tanks were inadequately
designed and manufactured from bare carbon steel. The corrosion of these bare steel
tanks is by far the most common cause of leaking USTs. Although the installation of
bare steel tanks is now illegal, many of the bare steel tanks still in use in
Foxborough have exceeded their life expectancy (commonly 15 years) and have little or
no protection against the corrosive action of the soil and water. Moreover, the exact
age, condition and location of many existing tanks may not be known, making it
extremely difficult to predict or prevent leaks.
A complete inventory and mapping of the location of each residential, commercial and
industrial underground storage tank was beyond the scope of S E A's investigation.
However, a preliminary list of 94 commercial and industrial tanks and 17 municipal
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tanks (with capacities greater than 250 gallons) registered with the Foxborough Board
of Selectmen and Fire Department was compiled. Eighteen of the 111 commercial and
industrial underground storage tanks are located in Zone II areas or the Future
Potential Aquifer areas. The age of only seven of these eighteen tanks is known. At
least one of these tanks has exceeded its 15-year life expectancy. It is likely that
the remaining 11 tanks are at or near their life expectancy. The remaining 93 tanks
are located over till and bedrock in secondary aquifer recharge areas or in sections
of town outside the proposed Water Resource Protection District.
Road Salt Storage and Application
Both the storage and excessive application of road salt in sensitive aquifer recharge
areas are potential sources of groundwater contamination. Several of Foxborough's
existing wells have come close to, or have periodically exceeded, the secondary
drinking water standard for sodium which is 20 milligrams per liter (mg/1).
The amount of salt (sodium chloride, NaCl) used to keep streets and highways clear of
snow and ice has steadily increased since the mid-1940's. Salt is an abundant,
affordable and very effective de-icing agent. Motorists in many states expect "bare
pavement" road conditions throughout the year, regardless of seasonal or climatic
conditions. As a consequence, state and local highway officials in New England bear
the responsibility of providing the highest level of vehicular mobility possible, some
to the point of using straight salt instead of a sand and salt mixture.
Sodium chloride is composed of approximately 40 percent sodium ions and 60 percent
chloride ions by molecular weight. When salt comes in contact with water, the sodium
and chloride ions disassociate and move with the surface water or groundwater. The
degree to which road salt will impact aquifers and public water supplies depends upon
several factors including: the amount, and method of salt applied to roadways, the
amount and method of salt storage, soil types, the distance between the source of salt
and the water supply, and groundwater movement.
Both the Massachusetts Department of Public Works facility, located on Route 140 and
the Foxborough Department of Public Works facility located on Elm Street, maintain
large road salt stockpiles in Foxborough. However, because both facilities are located
outside the boundaries of the proposed Water Resource Protection District and both
facilities store their road salt in enclosed sheds, the risk of groundwater
contamination is relatively low.
The Massachusetts Department of Public Works applies a mixture of 4 parts salt and 1
part calcium chloride (4:1) on state highways and Interstate roadways. The Town of
Foxborough applies a 3:1 sand to salt mixture to town roads. To mitigate the impact
of road salting within the proposed Water Resource Protection District, SEA
recommended that the Foxborough Board of Water and Sewer Commissioners work with the
town Public Works Department to implement the following Best Management Practices
(DEQE, 1981):
o All road crews should be aware of the location of sensitive aquifer
areas.
o Reduced application rates should be developed for roads within the Water
Resource Protection District.
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o Levels of service should be determined prior to the winter season.
Depending upon road type, weather conditions and traffic volumes, these
levels of service can range from no salt use, to mainly plowing and
using sand, to straight salt application on heavily traveled road
sections and critical intersections.
o Various mixtures of salt, calcium chloride and sand should be used in
the Water Resource Protection District. The State of Connecticut
recommends that a 7:2 sand-premix mixture should be used in sensitive
aquifer areas. Premix is 3 parts sodium chloride and 1 part calcium
chloride by weight.
Septic System Effluent and Nitrate Loading Analysis
In Foxborough, septic systems provide for disposal of household sanitary wastes and
sanitary wastewater from a variety of commercial and industrial operations. The 20,000
square foot lots in the center of town are served by a sanitary sewer system. Although
the town has developed a long range sewering plan, most of the sanitary waste in the
community is currently disposed of via septic systems.
The most common contaminant identified in groundwater is dissolved nitrogen in the form
of nitrate (Freeze and 'Cherry, 1979). A nitrate nitrogen loading analysis was
performed in order to evaluate the future potential impact, at 100 percent buildout
under current zoning, that septic system effluent, fertilizers, and roadway runoff
might have on groundwater quality. The goal of the nitrate loading analysis was to
determine, for each Zone II area, the maximum nitrate loading which can be allowed to
occur while maintaining an acceptable margin of safety below the drinking water
standard. As a result of the nitrate loading analysis, the sewage disposal density
and minimum lot size requirements in the Water Resource Protection District bylaw were
developed.
The current federal and state drinking water standard for nitrate nitrogen in drinking
water is 10 mg/1. To allow for an acceptable margin of safety, SEA recommended that
a management guideline of 5 mg/1 be adopted for the following reasons:
o to statistically ensure that actual concentrations which are likely to
fluctuate due to analytical variability, changes in aquifer recharge,
and inherent sampling error, are maintained below 10 mg/1 at least 90%
of the time (Cape Cod Planning and Economic Development Commission,
1979);
o to allow for plumes of higher concentration which could result from
periods of high nitrate loading and low groundwater recharge; and
o to allow for localized plumes of higher concentration resulting from
a continuous point source in a uniform flow field; and
o to be consistent with the findings of several studies performed on Long
Island.
The Long Island studies statistically evaluated nitrate concentrations measured in
numerous groundwater samples and concluded that when the mean concentration was 5.8
mg/1, 10 percent of the samples had concentrations exceeding 10 mg/1. In order to
achieve better than 90 percent compliance with the 10 mg/1 regulation, an average
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concentration of less than 6 mg/1 would be required, thus the recommended management
guideline of 5 mg/1.
Nitrate nitrogen concentrations are typically calculated using a mass-balance approach
over a unit area to determine the appropriate housing density (sewage disposal volume
and minimum lot size). Nitrate levels are thus evaluated on an individual lot basis.
The basic concept of this approach is that the water quality beneath a lot will be the
result of mixing nitrates from sewage, fertilizers, and road runoff with the recharge
from precipitation and septic system effluent.
The basic procedure for determining the future buildout (saturation density) nitrate
concentration was as follows:
1. Calculate total recharge from precipitation and sewage disposal within
each Zone II;
2. Calculate total nitrate loading from sewage, fertilizers and road
runoff;
3. Calculate nitrate concentration by diluting the total loading with the
total recharge.
As described earlier, the average recharge rate within Zone II was determined to be
15 inches per year. For the purposes of this analysis, it was assumed that water
pumped from individual wells is recycled back into the same aquifer such that there
is no net gain or loss of water to the aquifer.
The buildout analysis conducted for the Town of Foxborough by the Metropolitan Area
Planning Council (MAPC) and dated May, 1988 was used as the data base for calculating
the total number of buildable lots within each of zone of contribution. The individual
assessors' sheets were used to determine which of the lots listed by MAPC were within
each respective Zone II.
Nitrate loadings were estimated for individual residential lots using the loading rates
specified in the Water Resource Protection District bylaw as follows:
o 4 persons per dwelling unit
o 7 pounds per person per year
o 2 pounds nitrate per 1000 square feet per year from fertilizer (assumed
6,000 square feet of lawn per lot)
o 69.35 pounds nitrogen per lane mile per year
It was estimated that 7 percent of Zone II consists of roadways and other impervious
areas. The total number of equivalent lane miles was then calculated. The results
of the nitrate loading analysis are presented in Table 1.2.
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Table 1.2
Results of Nitrate Loading Analysis
Wading River Neponset/Rumford
Aquifer River Aquifer
Zone II Area 3.89 1.85
(sq. miles)
Total Recharge 3.8xl09 1.8xl09
(liters/year)
Total Nitrate 21.4xl09 12.7xl09
Loading
(mg/yr)
Nitrate 5.6 7.0
Concentration
(mg/D
Because the projected saturation development nitrate concentration (under current
zoning) exceeds the recommended management guideline of 5 mg/1, SEA recommended that
the minimum residential lot size within the Water Resource Protection District be
60,000 square feet. With this minimum residential lot size, the saturation development
nitrate loading will be below the guideline of 5 mg/1.
Groundwater Protection Strategy
Unlike some towns which have their entire water supply at one location, the Town of
Foxborough is fortunate to have an existing water supply system consisting of eleven
wells which tap four separate aquifer systems throughout town. The Town also has six
proven future well sites for which the required 400 foot protective radius has already
been acquired. Four of the proven future wells will be located in areas (two at Witch
Pond and two at Daniels Street/Mill Street) where the groundwater aquifer is not
currently being tapped. This spatial diversity provides an added degree of protection
from potential groundwater contamination and loss of a majority of the water supply
from a single contamination incident.
Having wells located in several areas throughout town, does, however, have significant
implications in terms of groundwater protection. Instead of concentrating on a small
area for aquifer protection, local officials must realize that a significant portion
of the town is within a water supply well zone of contribution. Foxborough's
groundwater protection strategy must be flexible, innovative, and be applicable
throughout the town. SEA, working closely with the Foxborough Board of Water and
Sewer Commissioners and the Planning Board, developed a groundwater protection strategy
that included a new Water Resource Protection District bylaw and Toxic and Hazardous
Materials bylaw, revisions to the Planning Board's subdivision rules and additions to
the Board of Health regulations. SEA also developed a groundwater monitoring program
to provide the town with an early warning system and a tool to better identify sources
of contamination.
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Water Resource Protection District Bylaw
Zoning has long been used as a means for municipalities to control growth.
Massachusetts General Laws (M.G.L.) Ch. 40A and its 1975 amendment, which is known as
the Zoning Act, list conservation of natural resources as one of the purposes of
zoning. Communities have the authority to enact zoning restrictions to protect
groundwater and often do so by regulating the density of development, allowable uses,
exemptions, and uses allowed by special permit.
The most common zoning technique used to protect groundwater supplies is an Aquifer
Protection or Water Resource Protection District bylaw. These bylaws are "overlay
districts," areas superimposed on the existing zoning map. The rules of the underlying
district continue to be in effect, except where the overlay district imposes more
stringent requirements. These overlay district bylaws are designed to prevent
contaminants from entering the groundwater by regulating land uses in the Zone II and
Zone III areas of public supply wells. Where induced infiltration supplies a
significant source of recharge to a well, surface water bodies are also protected.
Generally, the regulation of various types of land use is divided into four categories:
prohibited uses, restricted uses, permitted uses, and uses allowed by special permit.
Foxborough adopted a Water Resource Protection District bylaw in 1984, four years prior
to hiring SEA. This overlay district bylaw defined three protected areas: Area 1A
- the cone of depression generated by a municipal well after 7 days of continuous
pumping at its rated capacity or a 600-foot protective radius, whichever is greater;
Area IB - 600-foot protective radius around test wells designated as future municipal
wells; and Area 2A the surface of the land lying above the aquifer and designated
recharge areas and a 250-foot protective strip around surface water bodies. The
aquifer and aquifer recharge areas in Area 2A were delineated based upon data obtained
from the U.S. Geological Survey's Hydrologic Atlases and an estimated travel time for
certain contaminants.
The bylaw listed permitted uses, prohibited uses, and special permit uses. Overall,
the bylaw was fairly comprehensive and included, under the special permit process,
requirements for wastewater quality standards and limits on the volume of wastewater
discharged to a lot. Minimum residential lot size in Area 2A was 60,000 square feet.
Oil and grease traps and sediment traps were required before stormwater can be
recharged to the groundwater. Uses allowed in Area 1A and Area IB were limited to
conservation of soil and water, non-intensive agricultural uses, outlook recreation,
hunting, fishing, boating, and foot or bicycle paths. All other uses were prohibited.
Prohibited uses in Area 2A included the disposal of solid waste, hazardous waste,
liquid or leachable wastes, process wastewater, and the storage of petroleum or
hazardous wastes.
Although the list of activities regulated under the bylaw was comprehensive, the method
used to delineate the wellhead protection areas and aquifer recharge areas did not
accurately determine the extent of the town's four buried river valley aquifer systems,
nor did it consider the effect of different pumping and recharge scenarios.
Consequently, the land area protected under the bylaw was much smaller than the actual
area in the town that serves as primary and secondary aquifer recharge areas to the
11 existing wells and 6 proven future well sites. SEA drafted a new Water Resource
Protection District bylaw specifically designed to protect the extensive primary (Zone
II) and secondary (Zone III) aquifer recharge areas that had been delineated using
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MODFLOW. The bylaw regulates Zone II and Zone III areas, Future Potential Aquifer
Areas, and Body of Water 250-foot Setback Areas. On May 11, 1989, the new bylaw was
passed at the Foxborough Town Meeting.
The new bylaw contains an expanded list of prohibited uses which enables the Town to
control the siting of a host of businesses that store hazardous materials or generate
hazardous wastes or wastewater. For example, dry cleaning businesses, painting or wood
preserving businesses, and printing or photocopying establishments, store many
different types of hazardous chemicals on-site and generate contaminated process
wastewater. The disposal of this wastewater into on-site septic systems could pose
a serious threat to groundwater quality.
Based upon the results of the nitrate loading analysis, the bylaw requires that the
minimum lot size for any single or two-family residential lot be 60,000 square feet
(sf) with a minimum of 30,000 sf of upland area. For Zone II areas, the design sewage
flow for new development cannot exceed 165 gallons per day (gpd) per 10,000 square feet
of upland lot area. In Zone III, design sewage flow cannot exceed 165 gpd per 10,000
sf of total lot area. The bylaw also limits the amount of impervious surface area for
each type of lot in the Water Resource Protection District.
The Planning Board, as Special Permit Granting Authority (SPGA). has final authority
over the special permit provisions of the bylaw. Special permits are required for
certain types of new development and the expansion of existing non-residential and
multi-family residential development. Provisions for review by other town agencies
and for public hearings exist within the bylaw. The bylaw also encourages the use of
BMPs for the management of toxic and hazardous materials by specifying the types of
materials which must be submitted to the SPGA by the applicant. These materials
include:
o a complete list of all chemicals, pesticides, fuels, and other
potentially toxic or hazardous materials to be used, generated, stored,
or disposed of on the premises;
o a description of proposed measures to protect hazardous materials
storage areas from vandalism, corrosion and leakage;
o a description of proposed methods to recharge site runoff which must
pass through oil and grease traps before it is discharged to the ground;
o an erosion and sedimentation control plan; and
o projections of nitrogen concentrations and other relevant solutes in the
groundwater at the downgradient property boundary using the standards
listed in the bylaw. The projections may also be required for down-
gradient drinking-water wells.
Toxic and Hazardous Materials Bylaw
Foxborough also has the authority to pass local bylaws it considers necessary for the
protection of the health and welfare of its residents. A commonly adopted general
bylaw is a Toxic and Hazardous Materials bylaw. The purpose of this regulatory tool
is to require certain safeguards for handling and storing toxic and hazardous materials
rather than to regulate specific land uses. A general bylaw differs from a zoning
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bylaw in that pre-existing uses can be regulated by a general bylaw while they are
protected (grandfathered) as non-conforming uses under zoning bylaws. In addition,
unlike the new Water Resource Protection District adopted by Foxborough, a general
bylaw regulates specific practices throughout the town. Many existing small businesses
that use toxic and hazardous materials would not be regulated under the Water Resource
Protection District bylaw including:
o Dry cleaners
o Motor vehicle service and repair shops
o Photographic processing or printing businesses
o Electroplating/metal working shops
o Furniture stripping/woodworking shops
A Toxic and Hazardous Materials bylaw serves a dual purpose: it protects the town's
water resources and ensures the safety of people who work with the chemicals and those
who respond to spills, leaks or other emergencies. Many communities in Massachusetts
have adopted general bylaws that control materials such as pesticides, petroleum
products and toxic or hazardous chemicals.
The residents of Foxborough, recognizing the importance of controlling the storage and
use of hazardous materials by small businesses and industries, had adopted a Hazardous
Materials bylaw several years before this study was undertaken. SEA recommended that
the town strengthen and expand its existing control over toxic and hazardous materials.
The new Toxic and Hazardous Materials bylaw proposed by S E A included the following
important BMPs:
o the development of spill control and countermeasure plans
o requirements for areas where hazardous materials are pumped or
transferred
o guidelines for air emissions of solvents
o expanded requirements for registration of toxic and hazardous materials
o expanded requirements for the above ground and underground storage of
toxic and hazardous materials
o registration requirements for existing underground storage tanks
o notification requirements for the application of herbicides or
pesticides
The Board of Health is designated to enforce the bylaw and issue permits. To aid in
the enforcement of a Toxic and Hazardous Materials bylaw, SEA also recommended that
a local hazardous waste coordinator be appointed to periodically update both the list
and the map of potential contamination sources prepared by S E A.
Subdivision Rules and Regulations
Under M.G.L. Chapter 41, sections 81A-81J, known as the Subdivision Control Law,
Planning Boards are given the power and duty to adopt regulations that govern the
design and construction of ways, drainage, and utilities within proposed subdivisions.
With the appropriate regulations, the Foxborough Planning Board can be effective in
protecting the water resources of the Town.
Toward this end, SEA proposed revisions to the existing regulations that included
additional requirements under the subdivision design standards and expanding the Board
of Health's role in the review of subdivision plans. The existing regulations gave
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the Planning Board discretion to require the developer to pay for the services of an
independent consultant to evaluate the environmental impact of the proposed
development. Under the existing regulations, any report would have to assess the
impacts to:
o surface water quality, level, and runoff;
o groundwater quality and level;
o surface and subsurface soils;
o traffic;
o town services;
o physical environment;
o human environment; and
o entire town.
Additionally, the report should include a detailed statement of:
o any adverse effects which cannot be avoided if the plan is implemented;
o possible measures to mitigate the impact; and
o alternatives to the proposed plan.
SEA recommended that the report also include an assessment of the impact of the
proposed project on the town's water supply, and any proposed water conservation
measures.
Foxborough's subdivision rules and regulations contain detailed design standards for
streets, curbs, sidewalks, storm drainage, utilities, signs and easements. SEA
recommended the addition of the following design standards that focus on groundwater
protection.
Design and construction shall reduce, to the extent possible, the following:
o encroachment within any wetland or floodplain;
o volume of cut and fill;
o area over which existing vegetation will be disturbed, especially if
within 200 feet of a river, wetland or waterbody or in areas having
a slope of more than 15 percent;
o number of trees removed having a diameter at breast height (dbh) of
over 12-inches;
o extent of waterways altered or relocated; and
o dimensions of paved areas (including streets) except as necessary to
safety and convenience, especially in aquifer recharge areas.
In order to reduce erosion accompanying the installation of ways, utilities, and
drainage, and the resultant pollution of streams, wetlands and natural drainage areas,
SEA proposed that the Planning Board require the applicant to submit a sediment
control plan, including control methods such as berms, dikes, detention ponds,
mulching, and temporary sodding. SEA also recommended that the Planning Board limit
the use of de-icing chemicals on ways located within the Water Resource Protection
District.
The Foxborough Board of Health has a very important role in the subdivision review
process (M.G.L. ch. 14, Section 81U). The Board may approve or disapprove definitive
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plans based upon deficiencies in drainage, sewer lines, on-site sewage disposal or the
potential contamination of municipal wells, or any other area within their
jurisdiction.
The Planning Board's current subdivision rules and regulations contained no specific
review guidelines for the Board of Health. Instead, the Board of Health approves or
disapproves definitive plans based upon a determination as to whether any of the land
in the proposed subdivision can be used as building sites without injury to the public
health. In order to provide for a more thorough review of subdivisions proposed for
location within the Water Resource Protection District and supplement the powers of
the Planning Board, SEA recommended that the Subdivision Rules and Regulations be
strengthened to reflect the Board of Health's broad scope of jurisdiction and
authority.
SEA revised the regulations to give the Board of Health specific criteria by which
to review Definitive Plans for subdivisions within the Water Resource Protection
District.
When reviewing subdivision plans within the Water Resource Protection District, the
Board of Health would be required to evaluate the following issues:
o The geologic characteristics and percolation of each lot,
o Downgradient surface water impacts due to the migration of sewage-derived
contaminants. To assist them with their evaluation, the Board of Health
may require the project proponent to submit relevant hydrogeologic
information pertaining to the proposed subdivision that includes:
a geologic description of the parcel that includes the location
and depth of confining layers (silt and clay)
approximate aquifer thickness throughout the parcel,
groundwater flow directions,
determination of downgradient surface water features and wetlands
(on and off-site)
the projection of nitrogen concentrations downgradient of the
subdivision,
the impact of nitrogen, phosphorous, and other contaminants on
downgradient wetlands, ponds, streams and rivers.
Board of Health Regulations
The Town of Foxborough Board of Health Regulations were updated during 1988. The
update focused primarily on increasing setback distances required between septic system
components and wetlands, and revising sewage flow estimates. In general, the
regulations are very comprehensive. SEA proposed two important additions to the
Board of Health regulations to provide a greater degree of groundwater protection.
They were:
1. Increase the vertical separation distance between the maximum seasonal
high water table and the bottom of leaching trench (pit, galley, etc.)
from 4 feet to 5 feet. This will provide a greater degree of filtering
and nutrient attenuation and reduce the potential for septic system
failure due to excessive water table mounding which would flood the
system.
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2. Establish a permanent monitor well network (using existing wells
outside areas of pumping well influence) and monitor the wells monthly
for groundwater level. The groundwater levels should be compared to
the statewide monitoring performed by the U.S. Geological Survey and
a procedure established for applying correction factors to water level
data submitted from septic system deep test holes. The purpose of this
established correction factor is to ensure that septic systems are
designed using maximum historical water table elevation, and not a
single, uncorrected value recorded during a below normal, or dry,
springtime.
Groundwater Monitoring Program
Another component of Foxborough's groundwater protection strategy is the groundwater
monitoring program developed by S E A. In the past, water quality has been monitored
at the wellhead as required by the Massachusetts DEP. Currently, water from the Town's
11 public supply wells is treated for corrosivity. Contaminants of concern from
nonpoint sources include sodium from road salt application and nitrates from subsurface
sewage disposal. However, the major nonpoint source of contamination is the effluent
from the on-site systems which serve various residential, commercial and industrial
uses in the Town. Underground storage tanks and hazardous industrial and commercial
land uses are significant point source threats to groundwater quality. Contaminants
of concern from these point sources include solvents, petroleum products, metals, and
compounds with an extremely high or low pH. S E A's recommended groundwater monitoring
program will provide the Town with an early warning system as well as a tool to better
identify sources of contamination.
The monitoring well locations, upgradient of the wellhead protection areas delineated
by S E A as well as around certain surface water bodies, were chosen based on existing
land use and development patterns and hydrogeologic conditions. For example, induced
infiltration of surface water provides a significant source of recharge to several of
the Town's wells, while the types and amounts of toxic and hazardous materials stored
on-site and the wastes generated by several identified potential sources of
contamination dictated the placement of certain monitoring wells.
The new monitoring wells will be screened at various depths depending upon
site-specified parameters. After the implementation of the monitoring program,
Foxborough can, with minimal cost, strengthen its early warning system by expanding
the proposed monitoring well network to include wells installed by private sector
businesses, industries and residential developments. SEA recommended that the Town
incorporate into their monitoring well network the monitoring wells required for the
installation of new underground storage tanks and the wells required under the new
Toxic and Hazardous Materials bylaw. Foxborough's recently adopted Water Resource
Protection District bylaw requires special use permits for many land uses within the
district. SEA recommended that the town require permanent on-site monitoring wells
for every special permit use within the district boundaries. These wells could then
be incorporated into the well network.
For the first several years, SEA recommended that water quality samples should be
collected from the monitoring wells two times each year in order to establish baseline
water quality data and spot any significant trends. After that, samples can be
collected on an annual basis. At a minimum, the water should be tested for volatile
organic compounds (U.S. EPA Method 524), synthetic organic compounds (U.S. EPA Method
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504), sodium, nitrates, pH, and specific conductance. The Town should also test for
the parameters for which the DEP has established primary and secondary drinking water
standards.
Conclusions
While many other towns have experienced severe water shortages and lost all or part
of their municipal water supply to contamination, Foxborough has hired consultants who
have identified six proven future well sites, delineated the primary and secondary
recharge areas to the 11 existing wells and 6 future well sites, and written new
groundwater protection bylaws and regulations. In addition to the work performed by
its consultants, Foxborough has conducted household hazardous waste collection days
and aggressively acquired conservation land to protect open space and critical aquifer
recharge areas.
In Foxborough, it is clear that the local response to wellhead protection has been
diligent, creative, and successful. The protection of groundwater resources requires
a strong, unified local commitment to developing comprehensive groundwater strategies.
The residents of Foxborough know that in order to ensure the future viability of their
community, they must manage growth at the local level. Foxborough, through its
development of an innovative groundwater protection strategy, will be better equipped
to maintain the delicate balance between the ability of the groundwater. resource to
support growth and its ability to assimilate the resulting wastes.
Acknowle dgements
The material discussed herein is based upon the work performed for the Town of
Foxborough by S E A Consultants Inc. under the direction of Anthony J. Zuena, P.E.,
Principal-in-Charge and Michael J. Hudson, Project Manager. Kosta Exarhoulakos
executed the MODFLOW Model. Richard W. Heeley, P.G. , is also recognized for his sound
hydrogeologic contributions to this study. Mr. Warren McKay, Foxborough Water
Superintendent, the Foxborough Board of Water and Sewer Commissioners, the Foxborough
Planning Board and the residents of Foxborough are all recognized for their contri-
bution of data, as well as their cooperation and dedication to this project.
Selected References
Canter, L.W. and R.C. Knox. 1986. "Septic Tank System Effects on Ground
Water Quality." Lewis Publishers, Inc. Chelsea, Michigan. 336 pp.
Cape Cod Planning and Economic Development Commission. 1979. "Water
Supply Protection Project, Final Report." Barnstable, Massachusetts. 20 pp.
Freeze, R.A. and J.A. Cherry 1979. "Groundwater." Prentice-Hall, Inc.
Englewood Cliffs, New Jersey. 604 pp.
Frimpter, M.H., J.J. Donohue, and M.V. Rapacz. 1988. "A Mass-Balance Nitrate Model
for Predicting the Effects of Land Use on Groundwater Quality in Municipal
Wellhead Protection Areas." Cape Cod Aquifer Management Project. Boston,
Massachusetts. 37 pp.
Hall Groundwater Consultants, Inc. 1986. "Pumping Test Programs Version 7.0." St.
Albert, Alberta, Canada.
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Hughes, B.F., J. Pike and K.S. Porter. 1985. "Assessment of Ground-Water Contami
nation Nitrogen and Synthetic Organics in Two Water Districts in Nassau County,
New York." Center for Environmental Research, Water Resources Program. Cornell
University. Ithaca, New York.
Massachusetts Department of Environmetnal Quality Engineering, Office of Planning
and Program Management. 1981. "Road Salts and Water Supplies: Best Management
Practices." Boston, Massachusetts. 10pp.
Massachusetts Department of Environmental Quality Engineering, Division of Water
Supply, Office of Planning and Program Management. 1985. "Groundwater Quality
and Protection: A Gude for Local Officials." Boston, Massachusetts. 107pp.
Massachusetts Department of Environmental Protection, Division of Water Supply. May
1989. "Guidelines and Policies for Public Water Supply Systems." Boston,
Massachusetts. 160pp.
McDonald, M.G. and A.W. Harbaugh. 1984. "A Modular Three-Dimensional Finite-Differ-
ence Ground-Water Flow Model." U.S. Department of the Interior, U.S. Geological
Survey. Reston, Virginia. 480pp.
Metropolitan Area Planning Council. 1988. "Final Results of the Foxborough Build-
Out Analysis by Selected Scenarios." Presented to the Foxborough Growth Policy
Committee. Boston, Massachusetts.
United States Department of Agriculture, Soil Conservation Service. "Interim Soil
Survey Report for Norfolk and Suffolk Counties." U.S. Government Printing
Office. Washington, D.C.
Zen, E-an, Editor. 1983. "Bedrock Geologic Map of Massachusetts." U.S. Department
of the Interior, U.S. Geological Survey, In Cooperation with the Commonwealth
of Massachusetts, Department of Public Works. Reston, Virginia.
Biographical Sketch
Kimberly D. Noake, Project Hydrogeologist
SEA Consultants Inc.
485 Massachusetts Avenue
Cambridge, Massachusetts 02139
(617) 497-7800
Kimberly D. Noake is a hydrogeologist with SEA were she is responsible for projects
related to aquifer identification and protection. Prior to joining S E A, Ms. Noake
was employed by the CEIP Fund, Inc. as the Principal Investigator for a hydrogeologic
and land use study of Silver Lake, the water supply for Brockton, Massachusetts. While
employed by the Massachusetts Department of Environmental Quality Engineering, she
participated in the Cape Cod Aquifer Management Project (CCAMP) and authored the Guide
to Contamination Sources for Wellhead Protection. Town-wide aquifer identification
and protection studies and working with local communities to develop and implement
comprehensive groundwater protection programs are among Ms. Noake's foremost
professional interests. Ms. Noake received her M.A, degree in Environmental Studies
from Boston University and B.A. degree in Geology from Smith College.
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ABSTRACT
GROUNDWATER PROTECTION EVOLUTION: ACTON'S EXPERIENCE
The Town of Acton, Massachusetts is located 25 miles west of
Boston and is totally dependent on groundwater resources to
supply a population of approximately 18,000 people. In 1979 the
Town lost approximately 50 percent of the developed water supply
well capacity to volatile organics contamination.
Over the next decade the various Town Boards and Committees
worked with both volunteer resources and professional consultants
to study the aquifer systems of the community, existing potential
contamination sources, and possible problems from future
development under existing zoning. A Groundwater Protection
Committee was formed with representatives of each of the Boards
in Town with the authority to implement some aspect of a
groundwater protection program. This paper will review the
sequence of steps, successes and failures, undertaken by the Town
to develop and implement a multi-faceted program. The authors
are a resident who was formerly the Chairman of the Groundwater
Protection Committee during the development and passage of the
first set of groundwater protection zones articles (1985) and the
current Town Planner who was instrumental in the development of
the revised zoning articles adopted in 1989. The first author
worked as a consultant to the Town during a recent study to
technically define aquifer protection zones prior to the revised
zoning. The community's attitude and approach toward groundwater
management has evolved over the decade with each new effort
building upon the experience of the prior effort.
If you would like a copy of this paper, please contact the author
at (617) 969-0050
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Biographical Sketch: Duncan W. Wood
Proposed Speaker: "Groundwater Protection Evolution: Acton's Experience"
Education: Dartmouth College - AB: Engineering Sciences
Thayer School of Engineering - BE: Environmental Engineering
Massachusetts Institute of
Technology - MSCE: Water Resources
Northeastern University - MBA
Professional Experience:
Mr. Wood has 13 years of consulting experience in the water resources field.
Assignments have ranged from flood control planning to permitting for new
water supply wells. Mr. Wood has been an active user and developer of
computer modelling applications for both groundwater and surface water
studies. Mr. Wood is an Associate of the firm of Goldberg-Zoino &
Associates and had overall responsibility for the most recent geohydrologic
modelling study to establish groundwater protection zones for the Town of
Acton.
Community Experience:
Mr. Wood served as a member of the Acton Planning Board from 1982 to 1985.
He represented the Planning Board on the Town's Groundwater Protection
Committee and served as Chairman of that Committee. He was the presenter of
the first set of aquifer protection zoning by-laws adopted by the Town
meeting in 1985.
Biographical Sketch: Roland H. Bartl
Co-Author: "Groundwater Protection Evolution: Acton's Experience"
Education: Universitat Hohenheim,
Stuttgart,
Federal Republic of Germany.
Professional Experience:
Master's Degree,
Environmental Sciences &
Agriculture.
Mr. Bartl has been a professional planner with the Town of Acton since
August 1987. He has been instrumental in formulating and coordinating
Acton's Groundwater Protection District and Zoning Bylaw, adopted by Town
Meeting in April 1989. As planning director, Mr. Bartl is in charge of
reviewing all land development plans and he coordinates Acton's
comprehensive growth management plan. Prior to his Acton experience, Mr.
Bartl researched the effects of land development and agriculture on
endangered wetland species. He also spent 5 years as a farm manager and
teacher.
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EASTON'S EXPERIENCE AND THE CANOE RIVER AQUIFER ADVISORY COMMITTEE
Wayne P. Southworth
Superintendent
Water Division
Town of Easton
Easton, MA
We all take water for granted. We use it and abuse it, never really thinking
how it got to the faucet or if and when it will be there in the future.
The citizens of the Town of Easton, like many communities, are very concerned
and dedicated towards protecting its groundwater and water supply.
The Easton Conservation Commission has been actively acquiring land for many
years, presently having control of 1,364 acres. The State Department of Environ-
mental Management controls the Boderland State Park which comprises 594 acres in
Easton. They have also bought 1,089 acres in the Hockomock Swamp for conservation
purposes.
The Easton Water Division owns 240 acres surrounding its 5 pumping stations,
26 acres of which were recently purchased with a $500,000 Aquifer Land Aquisition
Grant from the State Department of Environmental Protection. There is now over 22%
of the property in Easton under state and local government control.
In 1973 a new Zoning Groundwater Protection District Overlay was established
which consisted of an 800 foot and a 1,600 foot radius around our existing munici-
pal well sites. Any proposed development within this area had to seek approval
from the Board of Appeals. Construction of an on-site sewage disposal system within
800 feet of the well site was prohibited.
In 1986 the Town hired I.E.P. Inc. of Northboro, Massachusetts to do an Aquifer
Protection Study, the purpose of which was to develop a comprehensive groundwater
protection program for the community, including the delineation of critical aquifer
recharge areas and evaluating water quality threats within these areas. Recommenda-
tions would then be made to establish an aquifer protection bylaw.
The study was completed in early 1987 and a model bylaw was proposed at the
Annual Town Meeting in the Spring. The local Planning Board had a few problems with
our proposal, so it was decided to postpone action until we had their full support.
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The Water Division worked with them during the year and held several public meetings.
At the Annual Town Meeting in May of 1988 the Planning and Zoning Board proposed
the new Aquifer Protection Districts and Bylaw themselves and it passed unanimously.
The new overlay covers over one-third of the town. Residential dwellings are
permitted on one acre lots and all other uses must request a special permit from the
Zoning Board of Appeals. A few of the prohibited uses are:
1. Sales or storage of fuels
2. Junk yards
3. Packaged sewage treatment plants
4. Car washes
5. Dry cleaning establishments
6. Metal plating establishments
In applying for a special permit the applicant must supply a list of all chemi-
cals, pesticides, fuels and other toxic materials that are to be manufactured, stored
or used on the premises. Projections of downgradient concentrations of nitrogen and
other relevant chemicals at the property boundaries. Appropriate groundwater models
and nitrogen loading calculations must also be provided.
The Water Division sponsored the first Household Hazardous Waste Collection Day
in the town in 1984. This effort was to educate the public as to the needs of pro-
tecting the community's groundwater through the proper use and disposal of household
chemicals. A permanent waste oil collection site was established at the Landfill at
that time, Since then we have worked on a regional Collection Day with the city of
Brockton. As of September 1989 we will have conducted seven collection days with
the most recent including the city of Brockton, the towns of Avon, East Bridgewater,
Easton and West Bridgewater. These events have been very successful exemplifying how
communities can cooperatie with one another.
The Canoe River Aquifer Advisory Committee (CRAAC)
The Canoe River Aquifer Advisory Committee was formed in February 1987 after
years of discussion among the Water Superintendents of Easton, Norton and Mansfield
regarding the protection of the aquifer that supplied a good portion of water to each
community. The adjoining town of Foxborough joined with us in May of 1987.
State Representative William Vernon worked with the committee to draft and file
legislation which was approved by the State Legislature on October 22, 1987. This
legislation has been regarded as a model for the state. This act gave us legitimacy
specifying that each community shall appoint three members and advise the Boards of
Selectmen, Planning Boards and other committees of the member towns relative to
development, conservation and zoning within the Canoe River Aquifer.
The committee has authority to review all plans of development of land within
the aquifer and report its findings to the appropriate agency.
The committee must inform and educate the public about water conservation and
the condition of the Canoe River Aquifer. An annual report shall be prepared and
provided to the Board of Selectmen of each member town.
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The Legislation was amended to allow the Town of Sharon to join the committee
in May of 1988.
The committee meets on the first Thursday of each month in one of the member
communities between 1:00 - 3:00 p.m. The fifteen members, for the most part, are all
public officials from Selectmen, Planning Board members, Conservation Committee
members, Board of Health, Water Commissioners and Water Superintendents.
Members of CRAAC have been very active since its initial formation. On October
1, 1987, the Executive Office of Communities and Development awarded the committee
a $40,000 strategic planning grant. I.E.P. Inc. was selected as the consultant to
develop a surficial geology map of the aquifer and provide us with a report includ-
ing a developable lot study, nutrient loading analysis, a town by town analysis
comparing the major characteristics of land use regulations for each town, recom-
mendations as to the future actions of the committee and to provide public workshops
as to its findings.
In May of 1987, CRAAC joined the Adopt-A-Stream Program supported by the Mass-
achusetts Department of Fisheries, Wildlife and Environmental Law Enforcement and
adopted the entire Canoe River. Since then, there have been sections of the river
adopted by other groups for specific reasons.
On May 7. 1988, the committee conducted its first annual spring Canoe River
Awareness Day at the Mansfield Fish and Game Club. This event was very successful
with over fifty in attendance. Presentations by state officials and committee mem-
bers were followed by a canoe trip. We received tremendous press and cable coverage
which helped to alert the public as to the needs of protecting this aquifer.
A winter Awareness Day was held at Wheaton College in Norton on February 12,
1989. Over fifty residents and public officials attended from the five communities.
Some of our accomplishments have been the installation of signs indicating the
Canoe River at all road crossings, the education of Highway departments as to proper
road salting practices and the elimination of road salt in sensitive areas around
the well sites. The Towns of Easton and Norton worked together to close an uninhab-
ited road between the two communities which had become a dumping ground since the
closing of area landfills. This area was next to the wells of both communities.
CRAAC held its second annual Canoe River Awareness Day on Saturday, May 6, 1989,
again at the Mansfield Fish and Game Club, which included a river clean-up in all
five towns, presentations by the D.E.Q.E., State Senators and Representatives, a
canoe trip and picnic.
The committee applied for and received a $2,000 grant from the Department of
Fisheries, Wildlife and Environmental Law Enforcement to create a composite asses-
sor's map of the aquifer. This map has been completed by I.E.P. and is now being
used to develop a list of land owners within the aquifer.
The committee is working with the Natural Resources Trusts of Easton, Norton,
and Mansfield to develop a land use conference during the winter of 1990. We will
invite land owners within the aquifer who have parcels that are prone to development.
The activities and accomplishments of this committee demonstrate again how
communities can work together to help protect our most vital natural resource.
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Wayne P. Southworth
Easton Water Division
417 Bay Road
South Easton, MA 02375
Wayne P. Southworth is Superintendent of the Town of Easton Water Division.
A twenty year employee of the Town of Easton, he has served as Superintendent since
1980. He has a Massachusetts grade 4 certification as a Drinking Water Supply
Facilities Operator.
He has been chairman of the Canoe River Aquifer Advisory Committee since its
formation in 1987. He serves on the Governors Hazardous Waste Advisory Committee
and is the First Trustee of the Massachusetts Water Works Association.
In 1988 the Massachusetts Municipal Association named him Outstanding Municipal
Employee of the Year.
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ABSTRACT
WELLHEAD PROTECTION FOR THE CHAFFIN POND WELLS
IN NORTH WINDHAM, MAINE
by W. Dana Perkins, Jr.
Director of Quality Control
Portland Water District - Portland, Maine
The Portland Water District delivers water to approximately 46,000
services, providing water to over 160,000 people in the Greater
Portland Area. Most of the water comes from Sebago Lake, but the
supply is also supplemented by wells in North Windham and
Cumberland. The North Windham system consists of 2 gravel packed
wells approximately 75 feet deep with a total short term pumping
capacity of 1000 gpm.
In 1978 the limits of the aquifer were defined using surface
watershed delineation and geologic inference on the nature of the
subsurface. Because Windham is a fast growing community, it was
desirable to better delineate the aquifer recharge area so as to
not unnecessarily restrict development within the outer boundary
of the recharge area. Bey doing a computerized ground water model
of the aquifer it was possible to separate the recharge area into
3 zones, each with different land use restrictions to accommodate
the appropriate level of protection to the well.
A hydrogeologist was hired to construct a three dimensional
computer model of the recharge area and to present recommendations
for implementation of an aquifer protection ordinance. This report
outlines the advantages gained by use of a 3 dimensional computer
model, over a 2 dimensional model and describes the recommendation
and implementation of an aquifer protection ordinance.
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Mr. Dana Perkins, Jr., the director of quality control of the
Portland Water Dist., Portland, ME., has been with the district
since 1981. Prior to this position, he was chief chemist of the
South Portland Wastewater Treatment plant. Mr. Perkins has also
authored and co-authored several papers related to water and
wastewater treatment in the northeastern area.
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BRIDGEPORT HYDRAULIC COMPANY
AQUIFER PROTECTION PROGRAM
MARK L. JOHNSON, P.E.
VICE PRESIDENT - ENGINEERING
BRIDGEPORT HYDRAULIC COMPANY
835 MAIN STREET
BRIDGEPORT, CT 06601
Abstract
Bridgeport Hydraulic Company (BHC) is the tenth largest
investor-owned water utility in the nation serving a population of
approximately 360,000 in 17 towns in Fairfield. New Haven and
Litchfield counties in Connecticut. BHC has always had an active
source protection program for both its watershed and aquifer
areas. Certain ground water pollution threats to its wellfields
in the mid to late 1980's required BHC to take a more proactive
stance in the area of aquifer protection. BHC initiated a three
stage aquifer protection program which consists of an aquifer
protection plan, aquifer protection workshops, and a public
awareness program. BHC's aquifer protection program has already
shown great benefits in helping to protect these valuable supplies
and developing better relationships with the communities in which
these wellfieids are located. The program has gained recognition
from both federal and state regulatory agencies.
I. Introduction/Background
Bridgeport Hydraulic Company (BHC) is the tenth largest
investor-owned water utility in the nation serving a population of
approximately 360,000 in 17 towns in Fairfield. New Haven and
Litchfield counties in Connecticut. BHC has 15 wellfields located
in 11 of these communities. These ground water supplies range in
capacity from 0.02 mgd to 16 mgd safe yield capacity. BHC's
ground water sources provide a total safe yield of approximately
30 mgd or 30% of the company's total 90 mgd safe yield capacity.
Beginning in 1984, BHC began to experience a series of
pollution threats to several of its wellfields. A summary of
these contamination events is summarized below:
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1. Lakeville Wellfield, Salisbury, CT - During a pump test
operation, BHC detected hydrocarbon in the production water
of its Lakeville Wellfield,, A consultant was immediately
retained to assist BHC in determining the source and
rectifying the problem. The potential source(s) were
located and an intercepter well was installed and the
pollution plume was diverted away from the well head. After
two years of aquifer monitoring, the wellfield was placed
back in service at a reduced pumping rate. BHC has
experienced a total cost to date of approximately $200,000
in monitoring well installation and sampling/laboratory
costs. The well head remains clean but the contamination
threat is still unresolved.
2. Salisbury Wellfield, Salisbury, CT - In 1984 BHC experienced
the detection of low levels of tetrachlorethylene (PCE) at
its Salisbury wellfield. Again, BHC immediately retained
the services of a ground water consultant to identify and
hopefully remediate the situation. Monitoring well
installation and laboratory analysis indicates the potential
source of pollution as a former dry cleaning establishment.
The owners of the dry cleaning establishment have long since
left the area and the existing owners of the property have
virtually no assets. BHC is forced to treat the production
water via air stripping. Total costs spent to date on this
project are approximately $200,000 and future design and
treatment costs are expected to approach $150,000.
3. Oxford Wellfield, Oxford, CT - In late 1987, BHC experienced
a solvent pollution contamination in close proximity to its
Oxford Wellfield. The solvent pollution was discovered as
part of the construction of a small shopping center. The
owner of the shopping center has cooperated with the company
and the Department of Environmental Protection (DEP) in
removing contaminated soils. However, contaminated ground
water still exists at a distance of approximately 800' from
one of the well heads: BHC continues to monitor the water
quality in the aquifer through its own monitoring wells and
wells installed by the owner. Recent heavy rainfall
patterns in Connecticut have assisted in mobilizing the
ground water contamination and BHC is finding the solvents
traveling towards the well head. BHC has spent a total of
approximately $50,000 to date on monitoring and
sampling/laboratory costs.
4. Hamill Wellfield, Litchfield, CT - BHC has experienced a
number of contamination events near this particular
wellfield. Sodium contamination has been identified as
coming from a local salt storage facility. In addition, a
Department of Transportation (DOT) garage facility, although
remote, has been linked to an isolated salt contamination
problem and hydrocarbon spill. In the first 6 months of
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1989, BHC has experienced 4 hydrocarbon spills/threats
around the perimeter of the zone of influence of the Hammill
Wellfield.
BHC has always had an active source protection program for
both its watershed and aquifer areas. However, the events
documented above made it clear to management that a more proactive
stance in the area of aquifer protection was required. In
response to this need BHC initiated a 3 stage aquifer protection
program. The first stage included the preparation of BHC's
aquifer protection plan. A major task in the plan was to model
each of the 15 wellfields using a two dimensional ground water
flow computer program. Once the aquifers were modeled and the
safe yield of each supply was determined, the zone of influence of
each wellfield was plotted on a map of the aquifer area. Within
each zone of influence, a survey was undertaken to determine the
location of potential sources of groundwater contamination. With
the potential sources plotted on the aquifer maps, certain
monitoring well locations were developed to provide an early
warning program for potential pollutants traveling towards the
wells. The plan also suggested aquifer protection ordinances for
those wellfield influence areas, emergency response programs for
contamination events and a list of the key chemicals to analyze at
each monitoring well. The second stage involved presentation of
the plan and a review of ground water protection techniques with
the towns. Finally, the third stage of the program consists of a
general public awareness program on aquifer protection.
II. Aquifer Protection Plan
BHC solicited the services of YWC, Inc. of Monroe, CT to
assist in the preparation of BHC's aquifer protection plan. YWC's
first task was to model each of BHC's 15 wellfields using a two
dimensional radial flow ground water computer program. YWC
actually used 2 ground water models—Aquifer and Plasm. BHC
supplied YWC with all available well drillers' logs, observation
well construction logs, pump test data, drawdown data, production
records, and other historical information to assist in preparing
the ground water models. YWC then took that information along
with information gathered from existing geological survey data
from each aquifer area, and field geological Interpretation and
developed the ground water models with their appropriate cell
configurations and boundary conditions. As part of the modeling
process, BHC was deeply interested in a more accurate
determination of the safe yield of each wellfield and instructed
YWC to calculate the safe yield utilizing the ground water flow
models. The criteria used for developing the safe yield was 180
days of pumping, with no vertical recharge, keeping the water
levels 5' above the screens at all times. Utilizing this
conservative methodology for safe yield, the critical zone of
influence is that area outside the well head which had a drawdown
of 1' under that drought condition.
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With the zones of influence of each wellfield determined and
plotted on an appropriate scale map, YWC then conducted field and
historical pollution inventories of these areas. Of specific
interest were former gas stations, dry cleaning establishments,
land fills, businesses, hazardous materials storage areas, etc.
In addition to actually surveying the entire area, YWC contacted
local officials and townspeople with historical knowledge of the
area for leads to possible contamination spots not visibly
noticed. Upon completion of this inventory of potential
contamination spots, BHC and YWC selected strategic locations for
early warning monitoring well installations. The installation of
the 15 monitoring wells'were scheduled for a two year program.
Water quality sampling from these monitoring wells will accent
BHC's regular water quality sampling program so that any pollution
activities in the aquifer will be immediately noticed and early
remediation plans could be put into effect. The aquifer
protection plan document contains specific water quality
parameters for each monitoring well that BHC's laboratory will
analyze. In addition, as most wellfields were located near a
surface water feature, stream sampling is also included as part of
the early warning system.
The aquifer protection plan also includes sections in the
document relating to emergency response techniques in the event of
an aquifer pollution contamination event, and suggested aquifer
protection ordinances for those towns affected. The emergency
response portion was developed to assist BHC in the event of a
contamination event which requires swift action. Included are
emergency phone numbers and response techniques. Emergency
response includes not only notification of appropriate state and
local officials but also includes a list of suppliers of portable
treatment facilities that could be utilized to treat the pollution
event. Other remediation activities identified for each wellfield
include such things as intercepter wells and alternate sources of
supply. BHC also presented two aquifer protection ordinances that
were developed for the town of Salisbury and the town of Wilton,
CT as suggestions to the other communities for adoption. These
ordinances include the restriction of certain activities such as
gasoline stations, dry cleaning establishments within the zones of
influence of these wellfields and also include hazardous waste
storage regulations.
III. Aquifer Protection Workshops
BHC determined in the early stages that communication of its
aquifer protection plan at the local level was a necessity. BHC
did not want this document to become placid and sit on the shelves
of local planning agencies. The plan pertaining to each community
was forwarded to its First Selectman and five copies were provided
for the various agencies in town. BHC engaged the services of the
Housatonic Valley Association (HVA), a non-profit conservation
group with experience in ground water protection, to assist in
making presentations to the towns' chief elected officials,
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commission members and interested citizens. Throughout the fall
of 1988, BHC visited all 11 communities with the HVA and presented
the aquifer protection workshops. The workshops included, (1) a
slide show on the basics of ground water protection and pollution,
(2) a slide presentation on BHC's contamination experiences, (3) a
review of existing federal, state and local regulations pertaining
to aquifer protection and potential future legislation, (4) a
review of the specifics of BHC's aquifer protection plan for the
wellfield in each community, and (5) a review of the regulatory
and non-regulatory actions each community could take to help
protect not only BHC's supplies but ground water In general.
The response to the workshops was tremendous with BHC being
able to get the message out to over 200 chief elected officials
and commission members. Although geared towards public officials,
most workshops were attended by many interested citizens. Any
aquifer protection program must include a workshop at the local
level for public officials.
IV. Public Awareness Program
The third stage of BHC's Aquifer Protection Plan program
includes a public awareness program. It is essential to Include
the general public in aquifer protection issues because not all
citizens are actively involved with local government. BHC began
an active media program in 1988 during the initiation of the local
workshop program. As mentioned previously, many interested
citizens did attend the workshops. Once the word got out on the
workshop program, several local associations asked BHC to provide
the workshop to their groups. BHC has conducted the workshop for
three towns in which BHC does not have public water supply wells
and civic organizations such as the Audubon Society, etc. In
addition, BHC has prepared press releases for all activities
concerning monitoring well installation, workshop announcements,
BHC's coordination during spill events with the DEP and local
officials, and general interest topics on aquifer protection.
Finally, BHC has prepared an aquifer protection pamphlet which
will be available to all BHC customers and will be distributed at
aquifer protection workshops and other presentations.
BHC plans future media contact with the general public. Such
items will include newspaper advertisements on the hazards of
aquifer contamination and video presentations in conjunction with
conservation groups on aquifer protection.
V. Conclusions
BHC's aquifer protection program has already shown great
benefits not only helping to protect these valuable supplies but
in developing better relationships with the communities in which
these wellfields are located. The aquifer protection plan has
been referred to on numerous occasion by BHC's internal source
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protection task force in regards to review of building development
proposals, highway projects, open space issues, etc. Some
examples of the effectiveness of the plan include:
1. Oxford Wellfield - restrictive covenants with a local
bank constructing a branch office within the zone of
influence. Restrictions in their deed include such things
as (1) no use of salt on driveways, (2) no underground
storage of any hydrocarbons, (3) treatment of all parking
lot runoff, (4) no hazardous chemical storage, and (5) a
complete monitoring system surrounding their proposed septic
system.
2. Cornwall Springs - BHC commented on a proposed residential
pond construction within the zone of influence. The
proposed pond construction could affect local ground water
hydrology. If it is not properly constructed, it could be a
source of contamination during construction. Also, most
ponds are chemically treated at some point in their life and
could affect ground water quality.
3. Westport Wellfield - The town of Westport immediately
adopted aquifer protection ordinances as a result of BHC's
aquifer protection plan.
4. All Wellfields - BHC began its own program of reviewing
underground storage facilities at its wellfield stations.
All underground tanks have now been removed and replaced
with either interior tanks or switched to propane.
5. Salisbury Wellfield and Lakefield Wellfield - BHC's
engineering department coordinated with the town of
Salisbury In preparing a design and specifications for an
underground storage vault for underground storage tanks.
These are just a few of the positive affects of BHC's aquifer
protection plan. The plan has gained recognition from the Federal
Environmental Protection Agency and the State Department of
Environmental Protection. Development of a plan and
implementation of a program such as the one presented can only
benefit other utilities as a tremendous protection and public
relations tool.
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MARK L. JOHNSON, P.E.
BIOGRAPHICAL SKETCH
EDUCATION
BS Civil Engineering
MS Environmental Engineering
Worcester Polytechnic Institute
1976
University of Maine - 1977 (Phi
Kappa Phi Honor Society)
University of Bridgeport - MBA
Program - 21 Credit Hours
EMPLOYMENT
1987 - Present
1983 - 1987
1979 - 1983
1978 - 1979
Bridgeport Hydraulic Company -
Vice President of Engineering
Bridgeport Hydraulic Company -
Director of Engineering
Bridgeport Hydraulic Company -
Superintendent of System
Operations
Bridgeport Hydraulic Company -
Engineer and Assistant Project
Manager - Trap Falls Project
PROFESSIONAL AFFILIATIONS
Geotelec, Inc., Norwalk, CT - Director
American Academy of Environmental Engineers - Diplomate
American Water Works Association - Member
Connecticut Water Works Association - Member
New England Water Works Association - Member
American Society of Civil Engineers - Member
CERTIFICATION
Registered Professional Engineer - Connecticut
Water Treatment Plant Operator - Class IV - Connecticut
Water Distribution Plant Operator - Class III - Connecticut
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PAPERS
"Bridgeport Hydraulic Company's Aquifer Protection Program" -
Wellhead/Aquifer Protection Conference (CWWA/YWC/IWR) -
October, 1988.
"Utility Interconnection - The Southwest Regional Pipeline
Experience" - Connecticut Water Works Association - May, 1986.
"Designing and Constructing the Trap Falls Water Treatment
Plant" - American Water Works Journal - March, 1983.
"The Use of Lamellae Settlers" - New York Water Works
Association - 1983.
"The Transition Problem in Pumped Wells" - American Geophysical
Union - 1978.
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ABSTRACT
"AQUIFER PROTECTION THROUGH LARGE SCALE COMPUTER MODELLING"
by David F. Edson, P.E.
Senior Project Manager
Dufresne-Henry. Inc., Westford, MA
The Barnes Aquifer, one of the largest in central and western
Massachusetts, extends over the eastern portion of the City of Westfield,
Massachusetts. The City has developed six wells in this aquifer, each
producing between 1,400 and 1,600 gpm, representing 90 percent of its total
water supply capability.
In 1985, the City enacted a set of aquifer protection bylaws and
developed a wellhead protection district map based upon surficial geology and
topography. In 1989, 3 sere detailed and thorough delineation of wellhead
protection areas was completed by use of large scale hydrogeologic computer
modelling.
Wellhead protection areas were detailed using MODFLOW, a
three-dimensional finite difference groundwater flow model developed by the
U.S. Geologic Survey. The area modelled was 14,000 feet by 32,000 feet,
represented by a 33 by 70 division grid system yielding 2,310 data nodes.
Node spacing varied between 400 and 900 feet. Aquifer characteristics and
hydrogeologic features incorporated into the model included:'
aquifer permeability, saturated thickness and storativity
initial head distribution, i.e., static water table condition
induced infiltration from surface water bodies
till barrier boundaries
pumping well withdrawal and interferences
Aquifer characteristics and hydrogeologic features were primarily
obtained from:
1. Analyses of City well testing records such as well logs and pumping
test results, and
2. A USGS water resource investigation of the area which at the time was
completed but not published.
Wellhead protection districts were developed based on criteria contained
in Massachusetts state guidelines for "Zone II" which includes 180 days of
continuous well pumping with no recharge from precipitation. Described are
methods of data analyses, our modelling approach, sensitivity analyses and
results. The advantages and disadvantages of the large scale modelling
approach to aquifer protection are discussed along with suggested guidelines
for its use in other communities.
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Professional Profile
DAVID F. EDSON, P.E.
SENIOR PROJECT MANAGER
Specialized Professional Competence
Ground Water Evaluation
Water Facility Design
Utility Management
Representative Assignments
Project Engineer or Manager:
Ground water exploration and supply development. Zone of contribution
delineation and aquifer protection and management.
Ground water quality evaluations, contamination investigations,
discharge permitting, and remediation projects.
Water facility evaluation and design of: wells, pumping systems,
distribution and storage.
Water quality assessments and design of water treatment facilities.
Capital planning and economic feasibility studies.
Professional Background
Registered Professional Engineer in Massachusetts, Maine, and
Connecticut.
Graduate engineering courses, Nottheastern University
M.B.A., State University of New York at Buffalo
B.S. in Civil Engineering, State University of New York at Buffalo
Entered Profession in 1976, joined.Dufresne-Henry. Inc. in 1986
Member: American Water Works Association
Member Ground Water Committee
New England Water Works Association
Chairman, Ground Water Committee
Member, Committee on Management Development
National Water Well Association
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Dufresne-Henry, Inc.
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Professional Profile
DAVID F. EDSON, P.E.
SENIOR PROJECT MANAGER
Publications and Presentations
Edson. D.F., "Re-emergence of the Wellfield", Journal of the New
England Water Works Association. Vol. 102, No. 4.
December. 1988.
Edson. D.F.. "Well Design", presented at Municipal Ground Water Supply
Seminar, sponsored by Resource Education Institute.
Inc., Westborough. KA.. September. 1986.
Edson. D.F.. "Microcomputer Billing for the Small Water Utility".
Journal of the New England Water Works Association. Vol.
96. No. 4. December. 1982.
121
DufresneHenry, Inc.
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DETERMINING THE AREA OF CONTRIBUTION TO A WELL FIELD:
A CASE STUDY AND METHODOLOGY FOR WELLHEAD PROTECTION
by
W. James Griswold and John J. Donohue, IV
BCI Geonetics, Inc.
Laconia, New Hampshire
ABSTRACT
This paper presents a case study of an hydrogeological evaluation for wellhead protection
conducted in an alluvial valley-fill aquifer in central Massachusetts. The criteria for wellhead
protection in Massachusetts are set by the Department of Environmental Quality Engineering
(DEQE) and are among the most technically detailed and sophisticated in the nation. DEQE defines
its wellhead protection areas as the zone of contribution to a well or wellfield under the most severe
pumping conditions that could be reasonably expected, i.e., 180 days of continuous pumping with
no area! recharge. This report presents a practical, technically defensible, step-by-step method
which ground water professionals can employ to produce a product to address the spirit and letter
of the law aimed at wellhead protection.
The evaluation begins with the development of an initial conceptual model of the area, evaluating
such key elements as surficial and bedrock geology, associated contributions to ground water
flow, recharge potential and induced infiltration from streams. The conceptual model is tested and
revised through the installation of monitoring wells. Detailed measurements of ambient conditions
both of ground water and surface water flows are taken to isolate the effects of the well(s) from the
natural variations in the overall flow regime. The aquifer is then subjected to the stress of a
required 120-hour pumping test. The results of analysis of the pumping test and ambient
conditions are used in a numerical model to extrapolate from the 120-hour test to the 180-day,
no-recharge conditions dictated by DEQE regulations. Finally, the modelled 180-day drawdown
results are subtracted from a potentiometric surface map reflecting average non-pumping
conditions. The area of contribution is delineated from a flownet constructed on the resultant
potentiometric surface.
INTRODUCTION
This paper presents a practical means of delineating wellhead protection zones using a case study
conducted in an alluvial valley-fill aquifer system in central Massachusetts. This approach
addresses the particular legal requirements of the State of Massachusetts' Zone n, defined as the
area that contributes recharge to a well or wellfield under the most severe pumping conditions that
could reasonably be expected, i.e., 180 days of continuous pumping with no area! recharge.
Although the wellhead protection requirements for the State of Massachusetts are among the most
technically detailed and sophisticated in the nation, several other states (e.g., New Hampshire) do
employ or are in the process of adopting regulations that incorporate many of the procedures
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demanded by Massachusetts. Thus, the methods described can be modified for other states that
have related statutory requirements.
The objective of the case study was to determine the zone of contribution for the Bondsville Fire
and Water District wellfield in central Massachusetts. The Bondsville wellfield consists of three
production wells constructed in glacial outwash sand and gravel. Two wells functioned reasonably
well, pumping a combined 225 gallons per minute. The third well had seen its yield decline
significantly from its original rated capacity of 125 gpm and had not responded to redevelopment
efforts. A new well had been drilled to serve as its replacement. To receive approval as a new
source in accordance with Massachusetts Department of Environmental Quality Engineering
(DEQE) Safe Drinking Water Guidelines, the water district had to delineate the 180-day,
no-recharge zone of contribution to the wellfield.
This paper is divided into three sections. The first, relatively brief section summarizes the salient
requirements of the Massachusetts Department of Environmental Quality Engineering (DEQE).
These requirements form the basis for the implementation of the hydrogeological program to
determine the zone of contribution. The second and third sections examine the approach used in
the case study to fulfill the DEQE requirements. Section Two concentrates on the steps taken to
formulate an initial conceptual model of the area, to test and update that model from field
investigation data. Section Three deals with the actual delineation of the zone of contribution to the
wellfield, tracking the process of moving from a conceptual to a quantitative model.
SECTION 1: REGULATORY REQUIREMENTS
The commonwealth of Massachusetts Department of Environmental Quality Engineering (DEQE) -
Division of Water Supply regulates the development and operation of all public water supplies.
The functional documentation of this regulatory process is entitled the "Safe Drinking Water
Guidelines and Policies," 1989 edition.
Within these guidelines, the development of a public ground water resource is governed by the
New Source Approval process. The process is a step-by-step exploratory and development
procedure that culminates in the DEQE Division of Water Supply Approval of a Public System.
The process is broken into eight major steps, the emphasis of which is the determination of zones
1,2, and 3 (wellhead protection areas) which are evaluated in relation to existing and future land
use activities, as they impact the long-term integrity of quantity and quality of the wells being
developed. The core of these requirements involves a quantitative hydrogeological evaluation to
determine Zone 2, defined as that area of an aquifer, which supplies recharge to a pumping well
under the most severe recharge and pumping conditions which can be realistically anticipated.
These requirements set forth a well-structured, long-term process intended to provide the necessary
background information for the long-term management of ground water resources. In order to
appropriately address the spirit of these requirements within the limits of realistic budgetary
constraints, creative hydrogeological techniques must be employed to ensure that theoretical and
technical considerations are not compromised.
SECTION 2: CONCEPTUAL MODEL DEVELOPMENT
2.1 Genera! Considerations
The development of a conceptual hydrogeologic model begins with a compilation and thorough
evaluation of material already available about the study area. This secondary data source material
may take the form of available hydrogeologic and geologic reports, mapping efforts by the USGS
and State Geological Surveys, published papers, university theses and dissertations, well logs and
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water quality analyses. A great deal of information can often be derived from conversations with
local drillers, many of whom keep files on work they have done. As trivial or as obvious as this
step appears, its importance is frequently overlooked, and it is often given short shrift, both from a
monetary and time standpoint in the overall project plan. However, it takes only a couple of
instances of drilling and logging an expensive monitoring well only to find that the USGS or the
Army Corps of Engineers has excellent records of a well they drilled in the very same area some
thirty or forty years before to realize the savings that can occur from a thorough perusal of existing
data.
There are a number of ways that secondary source data can be compiled for analysis. One
particularly useful means of obtaining a synoptic view of the study area is using map overlays and
cross sections. We have found that at least two scales of map are necessary in a wellhead
protection program study, one small scale map that provides a more regional perspective,
incorporating most, if not all, of the drainage basin, and a large scale map to show a more detailed
view of the wellfield and its immediate hydrogeologic environment. With properly sized base
maps, a series of overlay maps can be derived to display and correlate various types of data. In
general, we employ a minimum of three separate overlays, including a well location map with a
regional potentiometric surface indicated, a surficial geologic/geomorphic map and a
bedrock/structural geologic map. Other maps are frequently needed, e.g., an isohyetal map, if
precipitation shows significant area! variation, a water main distribution map, and a tax or property
ownership map. These maps can take as simple a form as a mylar overlay on top of a blowup of a
standard USGS quadrangle or it can be input into a more sophisticated mode of storage and
retrieval, such as a computerized geographic information system. In either case, the objective is
the same: to provide first a regional and then a detailed perspective of a variety of data at a glance.
A second means of analysis is with geologic cross-sections. Constructing a series of
cross-sections forces the hydrogeologist to incorporate a number of different data sets leading to an
overall model of the region. Data inconsistencies such as a pronounced head difference across an
area that ostensibly shows little geologic variation point to areas in need of further investigation.
Additionally, cross-section construction focuses attention on the key problem of boundary
conditions to the hydrogeologic system. Ultimately, the question of whether the situation can be
analyzed accurately as a one, two or three dimensional problem must be addressed. Drawing a
number of cross-sections and incorporating various data (surficial and bedrock geology, ground
water conditions) into those sections offers a good first step in qualitatively and quantitatively
addressing those issues.
The methods of analysis described above should be synthesized to create a formal conceptual
model It is important to make this step a written document It forces the hydrogeologist to sift
through, think about, and organize the ideas and data that have been collected. Putting the
conceptual model in print often reveals data gaps and grey areas of information that might
otherwise have been overlooked. It provides a means by which the project team may quickly
examine the state of the project and contribute to the overall effort by offering constructive technical
input The initial model will change as the project proceeds, sometimes radically, but the written
conceptual model focuses on the salient issues of the hydrogeologic environment being studied.
2.2 Bondsville Conceptual Model: Methods
In constructing the initial conceptual model for the Bondsville wellfield, the process described
above was followed. The objective was to obtain the best information possible on the prevailing
hydrogeologic conditions within time and budgetary limitations. Surficial geology was transferred
to the base maps, with particular emphasis on hydraulic properties and attention to recharge
potential to the valley fill aquifer. Well logs from local drillers, the USGS, DEQE and other state
agencies were compiled on two base maps scaled 1:960 and 1:6000. A potentiometric surface map
was drafted based on the available water level data. Investigations into precipitation data and
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possible impacts from regulated flows were made. Aerial photography was examined for the
possibility of significant bedrock structures that might represent zones of enhanced permeability.
Additionally, low-level aerials were used to better examine the surficial geology and glacial
geomorphology. A field reconnaissance of the area was made, ground truthing questions raised
during the process of establishing the data base. In particular, staff gauges were installed on
Jabish Brook, given the potential for induced infiltration. Several geologic cross-sections and an
aquifer thickness map at a 1:6000 scale completed the efforts prior to writing the initial conceptual
model.
2.3 Bondsville Conceptual Model: Written Description
The Bondsville Fire and Water District wellfield is located within the watershed of Jabish Brook, a
tributary of the Swift River in Palmer, Massachusetts. The wellfield lies approximately 1800 feet
above the confluence of Jabish Brook and the Swift River. There are presently three wells in the
wellfield, two on the west side of Jabish Brook and one on the east side. Well No. 3, on the east
side, is in the process of being replaced with an adjacent, newly constructed production well (Well
No. 4).
The Jabish Brook watershed is underlain by the Devonian Belchertown quartz monzodiorite
covered with approximately 15-20 feet of compact glacial till. The aquifer which supplies the
production wells is composed of glacially-derived stratified sand and gravel deposits approximately
50 feet thick in the vicinity of the production wells. The axis of Jabish Brook Valley trends
north-south and includes areas where the sand and gravel is over 100 feet thick. Several feet of
stream terrace deposits composed of sands, silts and gravels overlay the glacial outwash near
Jabish Brook.
There are several key hydrogeological factors that influence the size and shape of the zone of
contribution to this wellfield: leakage from Jabish Brook, the thickness and hydraulic conductivity
of aquifer materials, the behavior of the low permeability boundaries of the aquifer, areal recharge
and the rate and duration of pumping at the wellfield.
From the geologic setting, previous pumping test information, and field observations, it appears
that Jabish Brook acts as a significant source of recharge to the Bondsville Well Field. Induced
infiltration from Jabish Brook will slow the expansion of the cone of influence acting as a line
source of recharge. It is unknown whether this source of recharge will be continuously available
to the well. If the stream goes dry from excessive pumping and/or seasonal variations in ground
water levels, the stream will cease to act as a recharge source.
The stratified sand and gravel deposits that comprise the Jabish Brook Valley aquifer are thickest
along the central axis of the valley and grade into the lateral, north-south trending till and bedrock
boundaries. When the Bondsville wells are pumped, the cone of influence will expand
preferentially along the axis of the valley within the aquifer materials with the highest
transmissivities. These aquifer and boundary conditions will affect the cone of influence into an
elliptical shape with the long axis trending in a north-south direction.
2.4 Conceptual Model Revision: Analytical Modelling
Following its initial development, the conceptual model is subjected to testing. Questions and
hypotheses based on the model are developed and tested to improve the overall understanding of
the hydrogeologic environment. In general, this usually entails monitoring well installation.
However, in order to provide additional guidance in the placement of observation wells,
particularly for those designed for the long term pumping test, analytical modelling should be
performed. In this case, reasonably good control had been achieved on the type, extent and
hydraulic character of the aquifer from previous pumping tests and from well logs. Boundary
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conditions had been established, based primarily on surficial geologic mapping. The regional
gradient was estimated from the potentiometric surface map. Using this database, a preliminary
Zone n boundary was calculated using a uniform flow model and the superposition of radial and
one-dimensional flow fields to determine the area of contribution (Todd, 1980).
The calculations resulted in a downgradient stagnation point distance of 2280 feet and a capture
width of 7000 feet on either side of the wellfield. The 0-foot isopach for saturated sand and gravel
bordered by relatively impermeable till and bedrock was used to delimit the lateral extent of the
estimated zone. To estimate the upgradient boundary, we determined the amount of land needed to
produce the estimated 525 gpm pumped by the wellfield with a recharge rate of 17 inches/year, an
appropriate estimate for the climatic conditions and stratified drift deposits found in Bondsville.
600 acres of stratified drift was enclosed in the initial Zone n estimate.
2.5 Conceptual Model Revision: Monitoring Well Installation
To further refine the model, monitoring wells are installed. Monitoring wells serve several
purposes, functioning as a means to better understand the subsurface distribution and hydraulic
character of materials, as measuring points with which to revise the potentiometric surface map
and, later, as monitoring points for pumping test evaluation.
Well drilling in Bondsville consisted of hollow-stem augering of the hole with split-spoon
sampling at 5 foot intervals. Construction involved the installation of 2-inch, schedule 40 PVC
riser, 2-inch PVC 10-slot screen, sand pack along the screened section, backfilling with well
cuttings, a bentonite plug below a cement grout and a locking cap. Each well was developed with
a suction pump and response tested to ensure proper hydraulic connection to the aquifer. Well
locations and elevations were determined by survey to ensure water level measurements to within
0.01 feet (Figure 1).
2.6 Conceptual Model Revision: Formal Presentation
Following the installation of monitoring wells and the completion of regional and local testing of
the conceptual model, it is vital to revise the conceptual model to incorporate the new findings.
This stage of the program also entails committing to writing the data and analysis gathered since the
early stages of the project At this point, maps, overlays, well logs and cross-sections will play an
increasingly important role and should form a portion of the overall written effort. In essence, this
is the point at which the entire project pauses and takes stock of its position. Whether this revision
takes the form of an in-house presentation, a submission to State authorities or to the client, it
should have the status of an formal report in a usable format for easy future reference.
The conceptual model in the Bondsville study was revised principally based on accurate geologic
logs created from the drilling of each well and updated water level measurements. The logs
revealed the original model in need of only minor revisions of some contours of the aquifer
thickness map. Of greater importance to the model revision process was the result of the revisions
to the potentiometric surface map. With the more detailed information provided by water level
measurements in the monitoring wells, the area of influence resulting from the two operating
production wells was clearly visible. Jabish Brook did not function as a constant head boundary,
but did contribute water to the wells as the area of influence from the existing pumping wells
reached beneath and beyond the stream. Furthermore, the flow in Jabish Brook had decreased
from a measured 27 cfs in March, 1988 to 2 cfs in June 1988. The potentiometric map contours
were redrawn to indicate that Jabish Brook was losing water to the aquifer (Figure 1).
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to
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SECTION 3: ZONE II DELINEATION
Once the conceptual model has been updated and revised, the initial steps to move to a more
quantitative approach were taken. A critical step in the development of an accurate quantitative
model to determine the zone of contribution is die performance of a long term pumping test Both
a step test and a constant rate test were performed. The wellfield is the district's sole source of
water and could not be shut down for the duration of the test. Consequently, Wells No. 1 and 2
would pump continuously throughout all tests at their normal capacities (170 and 80 gpm) to
establish a quasi-steady state condition. Additionally, the Bondsville storage tank was to be filled
prior to all test pumping with a full day's average demand in storage at all times to ensure adequate
water supplies.
3.1 Ambient Condition Measurement
Two weeks before the beginning of the constant rate pumping test, five observations wells (MW's
12,13,14,15, and 19) were equipped with automatic recorders to measure water levels at hourly
intervals. The information from the data plots would be used to correct drawdown data from the
constant rate test for ambient conditions. At the beginning of the constant rate test, the general
trend was downward (Figure 2). Only the change in head with time for the final section of each
curve was used to modify the results of the drawdown measurements in the monitored wells,
adjusting the measured drawdowns for the downward trend.
Two staff gauges had been installed on Jabish Brook several months prior to test pumping, one
upstream and one downstream of the Bondsville wellfield. These were monitored periodically to
acquire some sense of the stream discharge with time. On two occasions rough estimates of the
stream's discharge were made using measured cross sections of the stream and the speed by which
floating objects passed. One measurement followed heavy rains and was approximately 27 cfs.
Several months later, another measurement was made at the same cross section, with only about
2.5 cfs flowing. Using readings from the staff gauges on those days produced an equation used to
determine a general sense of the magnitude of the stream discharge, e.g., whether the stream was
flowing at 5, 15 or 50 cfs. The record of staff gauge readings just prior to the start of the constant
rate test showed the brook was dropping in level.
3.2 Constant Rate Test
The constant rate pumping test lasted for five days. The pumping rate of 200 gpm was measured
with a flowmeter and with an orifice weir at the end of the discharge line. Water from the pumped
well was discharged into Jabish Brook below the downstream gauge, several hundred feet from
the nearest monitoring well to minimize any problem of recharging the aquifer. Six observation
wells were monitored automatically with automatic data loggers (MW's 12, 13,14,15,16, and
19) while all others and the pumping well were monitored by electronic hand probes.
Staff gauges on Jabish Brook were monitored during the first day of the test Unfortunately,
temperatures dropped substantially during the second day and large portions of the stream's water
froze, negating the accuracy and utility of staff gauge readings.
A series of water quality samples were taken on Days 1, 3 and 5 of the test, in accordance with
DEQE requirements. In addition, pH, CO2, specific conductance, and temperature were monitored
both for the pumping well and Jabish Brook. Following pumping, recovery was monitored for
three days, the amount of time needed for the well to recover to within 2 percent of the maximum
drawdown.
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11/23/88
-5.0
FIGURE 2
MONITORING WELL #13: PRE-PUMPING
12/6/88
J_
-8.0
2000 4000 6000 8000 10000 12000 14000 16000 18000 20000
TIME (minutes)
FIGURE 3: OBSERVATION WELL MW 13
DECEMBER 6-11,1988 Q = 200 gpm r = 72 feet
0)
0)
Z
O
cc
O
0.0
.001
.01 .1 1 10 100
t (time since pumping began: minutes)
1000
10000 100000
FIGURE 4: DISTANCE/DRAWDOWN PLOT (All monitoring wells)
DECEMBER 6-11, 1988 t = 7380 minutes
100
RADIAL DISTANCE FROM PUMPING WELL #4 (feet)
1000
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The pumping well essentially stabilized 20 minutes into the test with 98 percent of the maximum
drawdown of 31.6 feet occurring by that time. The time-drawdown curves of near observation
wells indicate that the pumping well began to draw upon water from Jabish Brook quite early in the
test (Figure 3).
Analysis of ambient conditions indicated water levels were generally moving downward in the
period of time prior to the pumping test, and no precipitation occurred during the test which would
alter that trend. Consequently, the drawdowns in those observation wells monitored prior to the
constant rate test were corrected to true drawdowns, that is, drawdowns plus or minus the amount
of change that would have occurred regardless of pumping. That procedure resulted in an adjusted
distance-drawdown plot of corrected monitoring wells which was used to calculate a transmissivity
of 44,000 gpd/ft and a storage coefficient of 0.09 (Figure 4). These values are consistent with the
results of the well log analysis and overall conceptual model derived for this hydrogeologic
environment Analysis of recovery curves confirmed the estimates of transmissivity obtained
using the distance-drawdown curves.
3.3 Revisions to Conceptual Model
The results of pumping test analysis provided an additional opportunity to fine-tune the conceptual
model in preparation for a more quantitative approach to the problem, particularly with regard to
the impact of Jabish Brook. The aquifer appears remarkably homogeneous and isotropic in
character. Observation wells with widely differing locations and orientations from the pumping
well showed a close clustering along the distance-drawdown plot (Figure 4). Preferential
drawdowns along a general east-west orientation can be explained by two factors. First, Wells
No. 1 and 2 are fairly close to one another, along a rough east-west strike. Interference leads to
more drawdown along that trend. With the addition of Well No. 4, that trend of drawdowns is
somewhat enhanced. Second, the presence of boundary conditions represented by the gradation of
thinning aquifer materials into glacial till uplands, particularly those to the east where till constricts
the Jabish Brook valley to a fairly narrow zone, adds to the apparent anisotropy.
The reaction of water levels in wells monitored prior to the constant rate test to a rainfall event
(Figure 2) and the evidence of a partial recharge boundary on the time-drawdown curves (Figure 3)
suggest a fairly significant effect from the stream on the aquifer. To calculate the amount of water
actually contributed from the stream during the pumping test, the distance-drawdown curve was
used to calculate the volume of aquifer affected by the pumping well. The volume was multiplied
by a storage factor to determine the amount of water actually removed. That figure was then
compared to the measured discharge of 200 gpm times the number of minutes pumped. The key
element in this calculation scheme is the storage coefficient Based on the conditions dictated by
the distance-drawdown curve and the 200 gpm pumping rate, the stream would contribute nothing
with S = 0.14, forming an upper bound to the problem. A lower bound might be S = 0.02, which
would entail approximately 85 percent of the discharge. Physical observation of the streambed
materials suggests that the 85 percent figure is unlikely. Noting that the calculated storage
coefficient from the distance-drawdown plots was 0.09, using a storage coefficient of 0.10 results
in a stream contribution of approximately 26 percent, while a storage of 0.08 has the stream
contributing 41 percent of the total discharge. The amount contributed changes with stream stage.
This is an expected response in this kind of stream system, since the base of the stream tends to be
armoured and hydraulically "tight" while the bank sides are sandy and much more permeable.
During periods of low flow, contribution to the aquifer by stream leakage is relatively small due to
the less permeable nature of the stream bottom. When the stage rises, however, water flows easily
into the aquifer through the banks, prompting a rise in the water table. During this test pumping,
more water came from the stream early in the test before the stream froze. Less came afterwards
since available water decreased due to the decline in stage. About 30-40 percent of the water
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discharged under these particular meteorological and hydrogeological conditions came from
infiltrated stream water.
3.4 Quantitative Model Development
To achieve a more accurate delineation of Zone n and to better understand the impact of the third
pumping well in the Bondsville wellfield, we elected to employ a numerical approach to the
problem using the USGS Three-Dimensional Modular Finite Difference Model (MODFLOW),
calibrating the model with the results from the five day pumping test. The problem is
two-dimensional (no confining layers and no flux from underlying till or bedrock), and a single
layer model was constructed.
The Jabish Brook valley was discritized into a variably spaced grid covering 3.77 square miles
(70001 x 15000'). The area of the wellfield was closely gridded to reflect the better data base and
the need for head distribution resolution. The glacial till uplands that flank the valley were modeled
as no-flow boundaries. Geological investigation, both surficial mapping and test drilling, had
revealed that the till in the region is quite "tight"; its water releasing capacity is low, particularly
relative to the transmissivities of the sands and gravels of the valley proper. The Swift River to the
south was modeled as a constant head boundary while the top (north) of the model was represented
as a combination of no-flow boundaries (in the areas of glacial till hills) and constant head
boundaries (in the stream valleys). The map of saturated sand and gravel produced for the initial
conceptual model was employed to provide initial values of aquifer saturated thickness. To
determine a value for hydraulic conductivity, we used the calculated transmissivity from the
pumping test (44,000 gpd/ft) divided by the average saturated thickness (40 feet), resulting in a
value of 146 ft/day. Hydraulic conductivity undoubtedly does vary in other portions of the Jabish
Brook valley, but because we had no direct data to that effect, we decided not to alter the K value
elsewhere in the model. Because saturated thickness varied, transmissivity varied in the model as
well. Specific yield was initially placed at 0.09.
Jabish Brook is a regulated stream. The entire flow is usually diverted upstream of the Bondsville
wellfield to the Springfield City Water System. Because of this situation, the stream can exhibit
significant variation in flow over time subject to the diversion, rainfall events, and groundwater
interflow below the diversion point. Accordingly, Jabish Brook experiences a period of seasonal
low flow in the vicinity of the wellfield. Jabish Brook did contribute water to the Bondsville
wellfield during this test pumping, but we felt that the most stringent pumping conditions that
could be anticipated under a 180-day, no-recharge scenario would be to have no stream
contribution to the wells. Consequently, the stream was not modeled.
The water table elevation was set uniformly at an arbitrary level and calibrated from that initial
condition. We did not have enough data to calibrate to ambient water level conditions, so the
model was employed in a "quasi-numerical" sense to generate drawdowns based on a flat water
table reflecting the varying boundary and aquifer conditions.
The model was run and calibrated using two stress periods to reflect the actual conditions of the
test pumping. The initial stress period consisted of two wells (1 and 2) pumping continuously at
rates of 170 and 80 gpm, respectively. This stress period lasted 30 days, reflecting the fact that
Bondsville's two existing wells pumped continuously prior to, during, and after the pumping test.
The second stress period was five days long, modeling the five day pumping test. It used the head
distribution from the first stress period as an initial condition and consisted of all three wells (wells
1,2 and 4) pumping at 170,80, and 200 gpm. The output from that model run was compared
with actual drawdown values obtained in the field at the end of the five day test pumping.
Calibration involved modifying saturated thickness (using detailed well logs from the test drilling
phase of the project) and uniformly varying specific yield throughout the modeled wellfield area.
The result was a set of modeled drawdowns that compared acceptably with the actual drawdowns.
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The calibrated model was re-run using first the 30-day, 2-well stress period followed by a 180 day
run with all three wells pumping, modeling the 180-day, no-recharge scenario.
3.5 Zone II Determination
To delimit the zone of contribution (as opposed to the zone of influence) to the wellfield involved
superimposing the 180-day modelled drawdown map onto the potentiometric surface map. To
manipulate these two data sets, the water table map was digitized and gridded with a random data
gridder from Geosoft®. The gridded file was filtered using two passes from a 9-point Manning
filter, and the result was a computerized water table map that matched the hand-contoured product.
The drawdown output file from the 180-day run of the numerical model was also gridded. The
two gridded files were then subtracted, creating a new grid that when contoured, represented a map
of the water table reflecting the impact of 180 days of no recharge pumping at the wellfield. A
flow net was constructed to determine where the zone of contribution occurred. From the results
of the flow net analysis, the zone of contribution corresponding to Zone n conditions was
established. This resulted in a Zone n of approximately 0.5 square miles (Figure 5). The zone is
bounded to the east and west by till and bedrock uplands; to the north of a locus of points
representative of a groundwater divide between the portion of the aquifer where groundwater
would discharge to the stream rather than be diverted to the wellfield; and to the south by a locus of
points representative of the downgradient stagnation points. Zone HI, defined as the area
topographically directly upgradient of Zone n was developed utilizing the Zone n and geologic and
topographic maps. It encompasses an area of till and bedrock uplands of approximately 1.2 square
miles.
3.6 Additional Protection Zones
With the establishment of Zones n and DI, the steps required by DEQE for a new source approval
are completed. However, the spirit of the law is concerned with the overall protection of the
aquifer. Recognition of the stream, aquifer, and wellfield interrelationships is a very important
consideration in the formulation of a groundwater protection strategy for this wellfield. Given the
definition of Zone n being "that area of an aquifer which supplies recharge to a well(s) under the
most severe recharge and pumping conditions that can be realistically anticipated," eliminating the
recharge contribution from Jabish Brook is appropriate. However, much of the time this wellfield
will be obtaining a recharge contribution (at times greater than 40 percent) from Jabish Brook.
Under these conditions, the quality of the water in the brook will have an impact on the quality of
the water produced in the wellfield. In summary, it means that contaminant threats outside of the
Zone n and m, but contributory to Jabish Brook may be significant to the long-term management
of this water resource.
CONCLUSIONS
The process of wellhead protection zone delineation to meet Massachusetts DEQE regulations
begins with the development and refinement of a conceptual model of the hydrogeologic
environment. This iterative approach relies heavily on secondary source material in its initial
stages, taking full advantage of published and unpublished material about the hydrogeology of the
area. Later, field checks to ground truth the gathered data, analytical modelling to point out data
gaps and monitoring well installation to better characterize subsurface conditions contribute to the
updating and revision of the model. Once the formal conceptual model is completed, it is possible
to move to a more quantitative approach to the problem. Designing and conducting a long term
pumping test results in the production of data that can be used to calibrate a numerical model of the
area. Running the calibrated model to the requisite 180 days with no areal recharge provides a map
of drawdowns that can be superimposed on an average ambient potentiometric surface map,
revealing, through construction of a flow net, the zone of contribution (not just influence) to the
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well or wellfield. That 180 day zone of contribution is Zone II; Zone El is the area upgradient of
Zone n to the extent of the nearest topographic divide. Delineation of Zones n and IE complete the
legal requirements set out by the DEQE, but it must be recognized, particularly in cases of induced
infiltration from streams, that contaminant threats outside the established protection zones must be
considered for responsible, long-term aquifer management
REFERENCES
Todd, D.K., 1980, Groundwater hydrology, J. Wiley & Sons, New York, NY.
BIOGRAPHICAL SKETCHES
W. James Griswold
BCI Geonetics, Inc.
P.O. Box 529
Laconia, NH 03247
Jim Griswold is a Staff Hydrogeologist with BCI Geonetics, Inc. of Laconia, New Hampshire.
Mr. Griswold's areas of particular interest and expertise include recharge in humid and arid
environments, well design, construction and hydraulics, and wellhead protection. His work in the
Northeast has focused on issues of ground water protection: aquifer delineation and analysis,
contaminant threats, and technical support for protection ordinances. A graduate of Pomona
College, Griswold holds an M.A. (English) and an M.S. (Geology) from Colorado State
University.
John J. Donohue, IV
BCI Geonetics, Inc.
P.O. Box 529
Laconia, NH 03247
Jack Donohue is a Senior Hydrogeologist and Hydrogeology Department Manager with BCI
Geonetics, Inc. of Laconia, New Hampshire. In this role he directs hydrogeologically related
corporate activities which involve the characterization of ground water systems throughout the
United States. Prior to joining BCI, Jack was a Senior Hydrogeologist with the Massachusetts
Department of Environmental Quality Engineering, Division of Water Supply. Jack is a Licensed
Geologist and holds a B.A. in Geological Sciences from the University of Maine at Orono. His
areas of professional concentration involve the characterization and engineering of ground water
systems.
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FIGURES
Figure 1: Monitoring Well Locations and Ambient Potentiometric Surface Map
Figure 2: Ambient Water Level Changes (MW #13)
Figure 3: Time Drawdown Curve (MW #13)
Figure 4: Adjusted Distance Drawdown Plot
Figure 5: Zone n, Resultant Water Table Map and Row Net
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The Use of Time of Travel in Zone of Contribution
Delineation and Aquifer Contamination Warning
James C. Hall, PhD, PE
Island Design
518 Town Hill Road
New Hartford, CT 06057
Determination of the Zone of Contribution for water supply aquifers tradition-
ally depends on the use of drawdown information under specified conditions. In
part, this has been due to the availability of computer models which produce this
information.
Recent advances in computer modelling make possible determination of travel
time as well as drawdown. This alternative tool has advantages in determination of
the zone of contribution as well as having proved useful in determining where mon-
itoring efforts should be located to provide known degrees of protection in terms of
warning time.
This paper discusses some of the principle advantages of the use of time of
travel rather than drawdown, such as:
1. Freedom from the influence of significantly sloping piezometric surfaces.
2. Proper accounting for the effects of high-permeability strata in the
aquifer.
3. Proper inclusion of recharge from nearby low-permeability areas.
4. Clear delineation of where monitoring should occur for definite warning
times.
This paper also discusses the use of computer models for travel time determi-
nation, including:
1. Required input data.
2. Conversion of conventional (e.g. PLASM, MacDonald-Harbaugh) format
models to be used with travel time models.
3. Problems with the use of transmissivity or averaged permeability based
models for the determination of travel times.
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The Zone of Contribution to an aquifer supplying a water supply well is of
considerable interest. Not only are there practical reasons for this, such as deter-
mining what threats may be present to a given water supply source, but there are
now various State and Federal programs requiring delineation of the Zone and spec-
ifying certain activities which may or may not take place within the Zone. Increas-
ingly, these delineations are being incorporated into legal documents, such as plan-
ning and zoning regulations, and thus the need for accuracy and defendability is
great.
The traditional approach to determining the Zone of Contribution to a water
supply aquifer takes one of two forms. The first is a specific radius around the
production well(s), determined either by de jure means (thou shalt protect 400 feet)
or by various approaches which incorporate some flexibility for the geology, such as
Connecticut's Level B mapping, which sets the radius as a function of well yield and
measured or estimated aquifer transmissivity. This approach, whether de jure or
flexible, does not take into account the real geology of the area in anything more
than a cursory fashion. The second approach has been based on observing (or
modelling) the drawdown caused by the production wells under certain specified
conditions and drawing the boundary at a specific value of drawdown. The condi-
tions and the value of drawdown to be used may be based on the best judgement of
the investigators, or may be written into regulations. Obviously, field observation
would be the best approach; equally obviously, it is not generally practical, as the
conditions are intentionally extreme and there is usually a lack of data. All of this
leads to the use of computer models to predict the performance of an aquifer, based
on a calibrated mathematical simulation of the performance of the aquifer.
The first question, however, is: is drawdown a satisfactory measure of the
Zone of Contribution in the first place? If not, why is it used and specified?
One's initial reaction to this question is why not? At first glance, it seems
reasonable to suppose that if the water level in an aquifer is drawn down by
pumping a well, then the water which was lost must have been removed by the well.
This is exactly true only for an aquifer in which there was no initial movement of
the groundwater. In such an aquifer, any drawdown must have come from pumping
the production well. The supposition is not true for an aquifer in which there was
some initial slope and thus some initial ground water flow. In that situation, some
of the drawdown down gradient from the production well is not due to withdrawals
by the production well, but to a reduction in the total quantity of through flowing
water due to the activity of the pumping well. There is a point at some distance
down gradient from the production well, at which the drawdown may be large, but
where the slope of the piezometric surface changes from towards the well to away
from the well. Water farther away from the well than this point does not reach the
production well, even though the drawdown is significant. Further, upgradient from
the well, water will reach the well (in some unspecified time), even though the
drawdown may be insignificant, as there is still a slope of the piezometric surface
towards the production well. At what initial slope of the piezometric surface does
this effect become significant? That is, at what initial slope will the results from
using drawdown instead of consideration of actual ground water slopes under draw-
down conditions become sufficiently different to warrant defense of the later and
rejection of the former? There can be no single answer to that question, as it de-
pends on the nature of the land use, possible contamination problems, and land val-
ues. Clearly in an area of low land values with no contamination problems, it is not
important. Conversely, in an area where land values are high and a proposed use
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of high value may be located within the zone defined by one approach, but not the
other, even small differences may become important.
It would be possible to define the Zone of Contribution to a well as the entire
ground water shed of the well under specified conditions (corresponding, presum-
ably, to those now used for drawdown). That is, it would be the entire area from
which water flows towards the well under those conditions. However, this does not
seem to me to be a particularly practical approach, particularly for wells located in
large watersheds (e.g. one I worked on recently in the lower Housatonic valley) as it
would include vast areas of land from which water would, theoretically, reach the
well—assuming the conditions held constant—but with time spans measured in
decades or centuries.
It seems to me that a more practical approach would be to define the Zone of
Contribution—or, better, several zones of varying stringency of protection—based
on travel time to the well. As a first pass at this, I suggest that the innermost
zone, perhaps corresponding to the State of Massachusetts Zone I, be defined as the
area around the well within which the travel time is so short as to make a change
to an alternative supply and/or provision of treatment, in the event of contamination
being discovered within the zone, prohibitively difficult: in other words, within
which there is a clear risk of a contamination spill reaching the public water supply
system without a chance for correction. The next zone (Zone II?) would be the zone
within which there is sufficient time to provide emergency treatment for the water,
but which is sufficiently close to the well to be clearly connected with it over a
water year: in fact, I suggest that this boundary be set at a travel time of one
year. The outermost zone most logically would be set at a distance corresponding
more or less to the expected useful (or economic) life of the well; perhaps 10 years
would be reasonable.
A second set of reasons for the use of time of travel as a criterion rather
than drawdown or pure slope is the influence of the local geology on the imminence
of a hazard. Consider the case in which an otherwise uniform aquifer of, let us
suppose, medium sand, contains within it a rather thin, but very elongated and nar-
row, stringer of very coarse sands and gravels with a permeability three orders of
magnitude greater than the general sand. This is not an unusual phenomenon in
New England, and could represent a periglacial stream channel in a more generalized
valley fill (for instance). The presence of the small amount of high permeability
material in thickness will not change the overall transmissivity significantly and
thus the ground water slopes will not be significantly affected—but the travel time
along the path of the coarse stringer will be three orders of magnitude less than
from some other point, not in the vicinity of the lens but at the same distance
(discounting the influence of vertical motion to the depth of the lens). Thus the
imminence of hazard from contamination from a source along this stringer will be
much greater. This will be properly accounted for on a travel time model, but not
on a model giving only slope or drawdown information. It is of some practical inter-
est, however, particularly since we often try to site wells to take advantage of such
stingers. Another situation is the one in which a well is close to a till/outwash
boundary. It is common practice to assume that the Zone of Contribution to a well
in outwash ends at the till contact. In fact, many ground water models which I
have had the opportunity to examine as a consultant also end at the boundary, on
the assumption that till is "impermeable" (which, of course, it is not, although the
permeability is rather low in general). A properly constructed model producing
head (and drawdown) distributions, which takes into account the influence of
139
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bedrock permeability as well as the influence of till, may show that there is signifi-
cant drawdown in these areas. But is this drawdown area to be considered part of
the Zone of Contribution and, if it is, which zone? Again, it is not possible to an-
swer this question unequivocally from slope considerations alone, but it can be an-
swered directly from time of travel modelling. (From experience with a number of
different aquifers, the answer turns out to be maybe sometimes.)
The last area which I wish to mention regarding the benefits of the use of
time of travel modelling is in siting monitoring wells, the purpose of which is pre-
sumably to give timely warning of approaching contamination so that alternative
measures can be undertaken. Time of travel siting makes it possible to use a com-
pletely rational approach to siting these wells: the object is to site the well at such
a distance that it will sample a significant fraction of the water (observe the rela-
tive concentration of flow lines, which is another output from the time of travel
mapping) and, more important, that the time of travel from the monitor to the pro-
duction well is adequate. Fortunately, it is very easy to define "adequate": it is
simply the sum of the sampling interval at the monitoring well, plus the time it
takes to analyze the sample, plus the time it takes to set up an alternative scheme.
In fact, it becomes possible to perform a cost/benefit analysis on various monitoring
schemes (within limits), based on the numbers of wells required and their locations
vs. the sampling interval at each well.
Time of travel modelling is not particularly difficult. There is at least one
computer program available to do it which is based directly on, and requires no ad-
ditional data than, the underlying head distribution model. However, it does require
that both the underlying head distribution model be created properly and that ade-
quate geologic information is provided. Since more information is being retrieved
from the model, more information is required going into the model.
Specifically, it is absolutely essential that the model adequately represent, at
each node, all of the significant strata and their permeabilities, including the
bedrock. (Significant strata being those that differ by an order of magnitude from
some sort of average permeability—in most cases, it is appropriate to model them all,
but in some cases, depending very much on the judgement of the modeller, some can
be lumped together). In addition, their depths must be accurately represented as
much as possible, as a high-permeability stratum which dries during the pumping
does not contribute to time of travel while it is dry, but does when it is wet. It is
conceivable to have very different travel times depending on pumping schedule with
the same overall gallonage pumped, if a high permeability stratum is being alter-
nately dewatered and flooded under one schedule, but permanently wet (or dry)
under another.
The model should be constructed so that the grid (finite difference or finite
element) covers the entire watershed of the aquifer, if at all possible. The use of
constant head nodes should be minimal (a properly constructed and calibrated model
should not require any at all), although constant flow nodes may be required at
some border locations either if the model does not cover the entire aquifer (for in-
put from areas beyond the model) or to account for exports from areas outside the
watershed being studied. The stratigraphy at each node must be analyzed and used
as input. Ideally, of course, one would take a core at each node. This is, clearly,
impractical! A completely satisfactory alternative, however, is to use available
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stratigraphic information in combination with a thorough analysis of the geomorph-
ology, stratigraphy, and historical geology of the area to interpolate intermediate
stratigraphy from the available information.
The model, of course, must be able to accept this information. The traditional
PLASM model and, indeed, any strict two dimensional model whether it is finite ele-
ment or finite difference, cannot do so, as they use either a bulk permeability at
the node, converted to transmissivity by multiplying by saturated thickness, or, in
the case of confined models, the bulk transmissivity. There simply is no way to al-
low for the effect of high-permeability stringers in these models. Three dimensional
models can, in principle, allow for these by means of using multiple layers and can
also incorporate bedrock characteristics properly. There are some real problems
with these models in areas of steeply dipping or heterogeneous topography and
geology, however, in that a large number of layers may be required. This may not
be feasible without the use of very large computers. Models do exist, however,
which are fundamentally two dimensional as regards head field output, but which ac-
cept the stratigraphy at each node. If possible, these should be used as the found-
ation for time of travel modelling except in the rare instances where information on
vertical flow rates and head differences is required.
Calibration of models to be used for time of travel outputs must be done with
a great deal of care. As noted earlier, constant head nodes are discouraged, as
they can distort the head field in their vicinity. Constant flow nodes are usable,
provided they are real (that is, there really is a constant flow of some sort in the
area). Streams and lakes must be accounted for by a scheme which allows for
recharge or discharge, depending on the relative heads. Actual infiltration rates for
each node must also be estimated closely, taking into account soil materials and
slopes of the ground surface. Aquifer recharge from interflow at points where val-
ley walls descend onto more level areas can be significant. Calibration is often ac-
complished by adjustments in bulk permeability or transmissivity. All that is re-
quired is to adjust the bulk permeability (or transmissivity) at each node of the
model to adequately reflect the influence of the high or low permeability strata. Not
only will this make time of travel calculations invalid, more subtly, it may make the
range of the model very limited: if the bulk permeability is influenced by a high-
permeability stratum rather high in the section, the model may calibrate perfectly
under normal conditions (and with all available calibration data) and yet fail miser-
ably under more extreme conditions when the high permeability stratum is dewatered
by pumping.
Instead, calibration must be accomplished by carefully keeping in mind the
real geology in the area. Permeability (which directly affects time of travel) should
be adjusted for calibration only to the extent that is consistent with the materials
and the geologic interpretation of the area. Stratigraphy (in particular stratum top
and bottom elevations) must be altered only to the extent that the result is geologi-
cally plausible. Substitution of one formation type for another at a particular ele-
vation at a node, or insertion of a new stratum, is subject to the same constraint.
It is my experience that, if the geology is well thought out and reasonably correctly
interpreted, very little adjustment of either stratigraphic thicknesses or formation
permeabilities will be required to complete calibration. Difficulties in calibration of-
ten indicate errors in geologic interpretation, which can and should be resolved with
further field investigation (it is rarely necessary to do subsurface work). It may
be necessary to seek consultation from an experienced glacial geomorphologist in
some instances.
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Calibration should be checked against all available aquifer information. Wet-
lands which are not perched water table situations should be reflected accurately,
and are a convenient check in areas with few (or no) ground water observations. A
properly calibrated model should simulate with reasonable accuracy any pump test
that has been performed, as well as the actual operating records if they are avail-
able. Perhaps it is worth noting, in passing, that many models do not report the
actual level in the pumping well, but rather the head at the node in which the well
is located. If this is the case, calibration is impossible. Correction must be made to
reflect the performance of the aquifer in the immediate vicinity of the well and the
well itself. The model referred to above does this automatically.
The summary for calibration is that the geology must be correct first; any
geologic approximations can cause large errors, although approximations are accept-
able provided the consequences are carefully thought out and will not affect the
validity or usability of the model. I cannot emphasize this point enough!
Conversion of PLASM and other models, including three dimensional models
which do not include adequate resolution to show significant, but thin layers, to
suitable forms for time of travel modelling is extremely difficult. I do not recom-
mend this, except in situations in which it is impossible for one reason or another to
create the model in the first place with adequate vertical resolution, either by use
of a model with allows full stratigraphy at each node or use of an adequate number
of layers in a three dimensional model (typically ten or more). It is usually cheaper
(and quicker) to remodel the area in question on a model which can handle the
required information.
In summary, I would like to emphasize that time of travel modelling has sev-
eral advantages, among which are proper accounting for the influence of initial
aquifer slope, high-permeability strata, and bedrock, and allowing a rational method
for siting observation wells; secondly, that computer models are available to perform
time of travel modelling; third, that considerably more input information about the
local geology is required to construct and calibrate these models, but that the in-
formation is readily developed by qualified geologists; fourth, that conventional mod-
els with inadequate vertical resolution cannot be used as input for time of travel
modelling and; fifth, that conventional models with inadequate vertical resolution may
give misleading results for head fields under extreme conditions.
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Dr. Hall currently holds two positions: although working for YWC, Inc., Monroe,
Connecticut, he also provides private consulting in computer programming, glacial
geomorphology, and ground water modelling. His address is Island Design, 518 Town
Hill Road, New Hartford, CT 06057.
Dr. Hall has modelled a number of water supply aquifers in Connecticut and
Massachusetts, including several time of travel studies.
His Doctorate in geology is from the University of Massachusetts, his Masters
from Purdue University, and his BA from Carleton College.
Dr. Hall has held posts as a college professor, as well as working for an
environmental regulatory agency and other environmental consulting firms.
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144
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DELINEATION OF CONTRIBUTING AREAS TO PUBLIC SUPPLY WELLS IN
STRATIFIED GLACIAL-DRIFT AQUIFERS
Paul M. Barlow
U. S. Geological Survey
28 Lord Road, Suite 280
Marlborough, Massachusetts 01752
Abstract
Several analytical and numerical methods are available for delineating
contributing areas to public supply wells. These methods employ variable levels
of computational complexity and require differing levels of data specification. A
recent advance in the ability to analyze contributing areas quantitatively has
been the coupling of particle-tracking algorithms to numerical ground-water-flow
models. A demonstration of the use of this method for delineating contributing
areas to hypothetical public supply wells pumping from a stratified glacial-drift
aquifer on Cape Cod, Massachusetts, has shown that (1) the location of a well with
respect to areas of recharge and discharge for the aquifer will have a significant
effect on the shape of a well's contributing area, (2) the recharge rate to an
aquifer and the pumping rate of a well will have a significant effect on the size
of the well's contributing area, (3) multiple pumping wells within an aquifer must
be considered simultaneously in the determination of a well's contributing area,
and (4) the lithology of the aquifer in the vicinity of the well must be well
defined.
The study also has shown that contributing areas determined using
analytical modeling were similar to those determined using numerical modeling
coupled with particle tracking for wells pumping from a thin, single-layer,
uniform aquifer with simple boundary conditions, and that the use of numerical
models for the delineation of contributing areas for wells in such an aquifer may
not be warranted. However, numerical modeling and particle tracking provide a
better quantitative tool than do analytical models for conditions normally
encountered in the field, such as thick, heterogeneous aquifers with complicated
boundary conditions in which several wells are pumping simultaneously. Under
these conditions, analytical models are not capable of providing sufficient detail
to predict accurately the land area which contributes water to a well.
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Introduction
The delineation of contributing areas to public supply wells is an
important component of State and Federal strategies for the protection of ground-
water quality. The delineation of contributing areas requires first, a
conceptual, and second, a quantitative understanding of the ground-water flow
system from which the well is pumping. Many quantitative methods are available
for analyzing ground-water-flow systems and, in particular, the delineation of
contributing areas to supply wells. However, many of the methods used to delineate
contributing areas to large-capacity supply wells are not capable of Integrating
the several hydrologic and well-design factors that may affect the size and shape
of a well's contributing area. Consequently, the accuracy of a contributing area
delineated for a supply well may be directly dependent on the method of analysis
chosen.
A recent, advance In the ability to analyze ground-water-flow systems
quantitatively has been the coupling of particle-tracking algorithms that trace
particle pathllnes within a ground-water-flow system to numerical ground-water-
flow models. The coupling of these methods provides a powerful tool for the
analysis of the factors that affect the response of an aquifer to the pumping of a
large-capacity supply well, and should Improve the delineation of a well's
contributing area. The U.S. Geological Survey Is conducting a project to
demonstrate the use, and assess the effectiveness and limitations, of numerical
modeling and particle tracking for the delineation of contributing areas to public
supply wells that tap stratified glacial-drift aquifers under selected conditions
of aquifer heterogeneity and well configuration. The results of the method are
being compared to contributing areas delineated using analytical models to gain an
understanding of the conditions under which the different analyses are most
appropriate. The study is being conducted In cooperation with the Massachusetts
Department of Environmental Protection, the Massachusetts Department of
Environmental Management, and Bamstable County. Massachusetts.
Purpose and scope
This report outlines two methods for delineating contributing areas to
public supply wells and presents some of the results of an ongoing study to
demonstrate the use, and evaluate the strengths and limitations, of these methods
for wells located in multilayered stratified glacial-drift aquifers. The methods
of analysis evaluated are analytical modeling and numerical modeling coupled with
particle tracking. A brief description of the sources of water to wells pumping
from stratified glacial-drift aquifers is presented as background to the methods
of analysis.
Sources of water to a well pumping from a stratified glacial-drift aquifer
Perhaps the first step in the delineation of a contributing area to a
public supply well is the identification within the hydrogeologic environment of
probable sources of water to that well. The identification of these sources aids
(1) development of a conceptual model of the ground-water-flow system, and (2)
selection of a method of analysis for the delineation of the well's contributing
area. In general, ground water at a well that taps a stratified glacial-drift
146
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aquifer has four sources: (1) recharge from precipitation which falls directly on
the stratified drift; (2) recharge from adjacent aquitards, such as silt, clay,
till and bedrock; (3) recharge from induced infiltration of surface water, such as
a nearby stream, river, lake or pond; and (4) removal from ground-water storage.
Sources (1) and (2) constitute water that is "captured" by a well that otherwise
would discharge at the natural discharge areas of the ground-water system; these
sources are referred to here as captured ground-water discharge.
The volume of water contributed by each source to the total volume of water
withdrawn by a well will change as a function of time. Morrissey (1987) used a
numerical flow model to investigate the transient response of a hypothetical
stratified-drift, river-valley aquifer to the pumping of a large-capacity supply
well located 200 feet from a river. Sources of water to the hypothetical well are
(1) water removed from storage, (2) water from induced infiltration of streamflow,
and (3) captured ground-water discharge. His results, reproduced here in figure
1, indicate that, during the first few hours of pumping, the well is sustained
almost entirely by water removed from ground-water storage. After approximately 1
year, water removed from storage ceases and the well is sustained entirely from
captured ground-water discharge and induced infiltration of streamflow. The
length of time that a supply well will remove water from ground-water storage will
depend on the aquifer in which the well is located and the screened interval of
the well. Wells that are screened near the bottom of a thick aquifer may remove
water from storage for a much longer time than is shown in figure 1.
Captured ground-water
discharge
Induced infiltration
from the river
0.036
(1/2 hour)
0.36
(9 hours)
3.65 36.5
TIME. IN DAYS
365
3650
Figure 1. Graph showing sources of water pumped from a well as a function of time
(modified from Morrissey, 1987, figure 27).
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Although Morrissey's results indicate that the sources of water to a well
may change over time, only steady-state (or equilibrium) conditions were
investigated for this report. Steady state implies that there is no removal of
water from storage. The contributing area determined for steady-state conditions
is the largest area that would be anticipated for a given average recharge rate to
the aquifer and average discharge rate of a well because the land (contributing)
area needed to sustain the discharge rate of the well decreases proportionately
with contributions from ground-water storage.
The area of stratified drift necessary to supply a well with water may be
determined from the discharge rate of the well and the recharge rate to the
aquifer, if recharge from precipitation is the only source of water to the well.
The discharge rate of the well (Q) is equal to the recharge area of the well (A)
multiplied by the recharge rate to the aquifer (r). Therefore, the area necessary
to recharge the well at its steady-state pumping rate is Q/r. This relation
provides a simple means of determining if the recharge area delineated for a well
is large enough to sustain its withdrawal rate.
Methods for delineating contributing areas
Analytical modeling
Several analytical models can be used to delineate contributing areas to
public supply wells. These models require that simplifying assumptions be made
about the ground-water system from which a well is pumping and the geometry of the
well itself. These assumptions include simplifications or idealizations of
aquifer boundary conditions, homogeneity of aquifer properties (such as hydraulic
conductivity), and simplification of well design (such as a fully penetrating well
screen). Several of these models are discussed by U.S. Environmental Protection
Agency (1987), Morrissey (1987), van der Heijde and Biljin (1988), and Newsom and
Wilson (1988) and need not be reviewed here.
The aquifer chosen for study is located in Eastham and the southern part of
Vellfleet, Cape Cod, Massachusetts. The aquifer consists of stratified glacial
outwash approximately 100 feet thick underlain by lacustrine silt and clay
approximately 400 feet thick. These deposits are underlain by granitic bedrock.
Precipitation which falls on the outwash is the only source of recharge to the
aquifer; recharge has been estimated to be 17.4 in/yr (inches per year) (LeBlanc
et al, 1986). Several ponds in the study area are in hydraulic connection with
the aquifer and may be sources of water to wells located near them. A map of
water-table altitudes for the aquifer (figure 2) indicates that ground-water flows
from the central area of Eastham toward Town Cove, Cape Cod Bay. Blackfish Creek,
and the Atlantic Ocean.
Contributing areas to two hypothetical supply wells completed in the
aquifer underlying Eastham were delineated by superimposing (or subtracting)
steady-state drawdowns determined using the Theim-Dupuit method (Kruseman and de
Ridder, 1983) onto a map of prepumping water-table altitudes. The Theim-Dupuit
equation is used to determine steady-state drawdowns in the vicinity of a fully
penetrating well pumping from an unconfined aquifer. The Theim-Dupuit method of
analysis was chosen for this study because the aquifer is unconfined and because
148
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WELLFLEET
4»*4rpo"
ro*oo'oo"
42*00'00"
Cape Cod Bay
STUDY AREA
Atlantic
Ocean
EXPLANAT ION
-S-WATER-TABLE CONTOUR — shows
altitude of water table, in feet.
Dashed where location approximate.
Contour intervals are variable.
Datum is sea level.
Town Cove
2 MILES
KILOMETERS
Figure 2. Location of study area and average water-table altitudes for the
stratified glacial-drift aquifer of Eastham and south Wellfleet, Massachusetts,
149
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there are no impermeable or surface-water boundaries that might influence the
distribution of drawdowns in the vicinity of the wells. It was assumed that the
pumping rate of well B would not cause a landward encroachment of the
saltwater/freshwater boundary at the shore of the Atlantic Ocean, located 2,500
feet downgradient from the well, because the drawdowns were anticipated to be
small for the simulated discharge rate of 0.5 Mgal/d (million gallons per day) and
because a discharge rate of 0.5 Mgal/d Is less than approximately four percent of
the total discharge from the aquifer. The assumption that the
saltwater/freshwater boundary is unaffected by pumping at well B might not be
valid for increased discharge rates. Application of the Theim-Dupuit method to
the determination of drawdowns produced by wells A and B requires that several
assumptions be made. These are (Kruseman and de Ridder, 1983)--
(1) The aquifer Is of infinite lateral extent, homogeneous, isotroplc and
of uniform thickness over the area influenced by the well;
(2) the water-table surface is nearly flat prior to pumping;
(3) the aquifer is pumped at a constant discharge rate;
(4) the well fully penetrates the aquifer and flow is horizontal and
uniform everywhere In a vertical section through the axis of the well;
(5) the velocity of flow Is proportional to the tangent of the hydraulic
gradient;
(6) the aquifer is unconfined;
(7) flow to the well Is In steady state; and
(8) a concentric boundary of constant head surrounds the well.
One further condition which must be specified in the Theim-Dupuit method is
a radial distance from each pumping well at which drawdown is known. For this
analysis, two distances were used at which drawdown was assumed to be equal to
zero. The distances used were 2,300 feet and 11,500 feet. The first distance,
2,300 feet, was chosen because It is the distance required to intersect an area of
stratified drift necessary to sustain the pumping rate of each well for the
condition of a flat water-table surface prior to pumping, for a pumping rate of
0.5 Mgal/d and recharge rate to the aquifer of 17.4 in/yr. The second distance,
11,500 feet, which is five times the first distance, was chosen for comparison.
It must be realized that the assumption of zero drawdown at these distances is
simply a means to compute a rough approximation of drawdown within the cone of
depression of each well, and is a limitation of the analytical model. In
actuality, the cone of depression extends to the concentric boundary of constant
head listed in assumption 8. Assuming a fictitious drawdown of zero at some
distance from a supply well is an arbitrary assumption which might not be
appropriate in many cases. The errors Introduced by using this assumption should
have a negligible effect on the pathlines used to delineate the contributing area
for each well, for the assumption to be valid.
Drawdowns were calculated for several points in the vicinity of two
hypothetical supply wells located in the aquifer. The well locations are shown in
150
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figure 3. Well A is near the crest of a natural recharge mound where the
hydraulic gradients are very flat; well B is located between this ground-water
mound crest and the discharge area of the Atlantic Ocean. Hydraulic
characteristics used in the calculations of drawdown are given in Table 1. These
characteristics were determined from well logs in the area of the hypothetical
wells and from the results of aquifer tests that have been conducted in the
stratified-drift deposits of Cape Cod, Massachusetts (Guswa and LeBlanc, 1986).
Drawdowns were calculated at distances of 500; 750; 1,000; 1,250; 1,500; 1,750;
and 2,000 feet from the pumped wells. Calculated drawdowns were subtracted from
the map of prepumping water-table altitudes to produce new maps of water-table
altitudes in the vicinity of each well (figure 3). Contributing areas were
delineated by constructing a flow net near each supply well. Flow lines were
drawn perpendicular to lines of equal water-table altitudes because the aquifer
was assumed to be homogeneous and isotropic (Freeze and Cherry. 1979).
Table 1.--Parameters used in the determination of drawdown for
wells A and B using the Theim-Dupuit method.
Hypothetical well A B
Horizontal hydraulic conductivity (ft/d) 150 170
Aquifer thickness (ft) 81 46
Transmissivity (ft2/d) 12,150 7,820
Discharge rate at the well (Mgal/d) 0.5 0.5
Contributing areas for the two wells determined using the analytical model
are shown in figure 3. The drawdowns computed using the two assumed distances to
zero drawdown differed in each of the two hypothetical cases. However, the
differences between the drawdown determined using each of the two assumed
distances were not great and did not affect significantly the delineation of
contributing areas to each well. The contributing areas determined using each of
the assumed values did not differ significantly because the accuracy of the hand-
generated pathlines was insensitive to the differences in these drawdowns. Figure
3 shows only the results for the radius of influence equal to 2,300 feet. The
results indicate that the shape of the contributing areas are strongly dependent
on the location of the well in the aquifer. The contributing area delineated for
well A, near the crest of the recharge mound, is ovoid-like in shape; water is
captured about equally from all areas around the well. The contributing area
delineated for well B, located between the crest of the ground-water mound and the
discharge areas of the aquifer, is elongate in shape; water is captured primarily
from areas which lie upgradient from the well.
Numerical modeling and particle tracking
Numerical ground-water flow models have been used extensively for the
conceptual and quantitative analysis of ground-water flow, including the
delineation of contributing areas to public supply wells. Numerical models are
used to determine ground-water heads at specified locations within a simulated
aquifer. Ground-water flow nets then are constructed from these computed heads to
delineate a well's contributing area. The construction of a two-dimensional
ground-water flow net for a three-dimensional flow problem is a time-consuming
task that may yield inaccurate results because it is necessary to ignore flow in
the third dimension.
151
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East
T
We I I f leet
2 VILES
1
3 KILOMETERS
(b)
(t)
EXPLANATION
-s-WATER-TABLE CONTOUR— -shots oltitudc of water tabU, in feet
Dashed where location approximate. Contour intervals are
variable. Datum it sea level.
- ...... Contributing area determined using analytical model.
B Location of hypothetical supply veil.
Figure 3. Water-table contours and contributing areas for hypothetical supply
wells A and B, each pumped at 0.5 Mgal/d, determined using an analytical model.
152
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Particle tracking offers a relatively simple yet quantitatively powerful
alternative to the construction of ground-water flow nets. Particle tracking Is
the tracing of fluid particle pathlines through a ground-water-flow system over
time (Pollock, 1988). The steps in the mathematical determination of pathlines
are as follows: A numerical flow model is used to compute ground-water heads at
individual cell nodes within a simulated aquifer. These nodal values of head are
used to compute intercell flow rates by Darcy's Law; ground-water-velocity vectors
derived from these flow rates may be computed for every point In the flow field.
Pathlines are then determined from the ground-water-velocity vectors.
Particle-tracking algorithms differ in their method of determining ground-
water-velocity vectors. Pollock (1988) has developed a semianalytical particle-
tracking algorithm for use with block-centered, finite-difference, ground-water-
flow models, and has written a computer program based on this algorithm for use
with the modular ground-water-flow model of McDonald and Harbaugh (1988) . The
mathematics of the particle-tracking algorithm may be found in Pollock (1988).
Nt
EXPLANATION
D Activ« cell
HSpecifi«d-h«nd c«ll
0 Inoctiv« c«l I
(or to not mode ltd)
I yiLES
KILOMETERS
It
COLUMN
Figure 4. Grid and boundary conditions for the two-dimensional and top layer of
the three-dimensional ground-water flow models.
153
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COLUMN
o
oc
COLUMN
tl 25
2 MILES
0 1 2 KILOMETERS
EXPLANATION
31
-5-CALCULATED WATER-TABLE CONTOUR—Shows altitude of calculated
water-table altitude, in feet. Datum is sea level.
• Specified-heod cell.
Figure 5. Calculated water-table altitudes for (a) two-dimensional model and (b)
layer 1 of three-dimensional model.
154
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Two-dimensional and three-dimensional ground-water flow models were
developed for the unconfined aquifer of Eastham and south Wellfleet, Massachusetts
(figure 4) to demonstrate the use of numerical modeling and particle tracking for
the delineation of contributing areas to supply wells located in stratified
glacial-drift aquifers, and for comparison to the analytical model results
described previously. The three-dimensional flow model consists of 5 layers, with
48 rows and 39 columns of grid cells in each layer. The simulated aquifer is
bounded laterally by specified-head cells in the top layer and by no-flow
boundaries in the four lower layers; it is bounded on the bottom by a no-flow
boundary. The two-dimensional flow model consists of a single layer, with 48 rows
and 39 columns of grid cells. The single layer, two-dimensional model is bounded
laterally by specified-head cells and vertically by a no-flow boundary. Each of
the models is bounded on the top by a water table that receives a uniform rate of
recharge from precipitation.
The models were calibrated using average ground-water altitudes measured in
16 observation wells and by 7 pond gages in the study area during 1963-88.
Horizontal and vertical hydraulic conductivities were estimated from the
lithologic logs of several test holes completed in the aquifer. Values of
hydraulic conductivity were varied both horizontally and vertically within the
simulated aquifer. Initial estimates of hydraulic conductivity and recharge to
the aquifer were modified during calibration to obtain a root-mean-square error
between observed and simulated ground-water altitudes of 0.8 feet for the two-
dimensional model and 0.9 feet for the three-dimensional model. These mean errors
are consistent with the accuracy of the map of water-table altitudes made for the
study area and with the level of understanding of both the distribution of
hydraulic conductivity within the aquifer and recharge rate to the aquifer;
additional calibration could not be justified on the basis of available data.
Ground-water altitudes determined for the top layer of each model are shown in
figure 5. The similarity of these simulated water-table altitudes with those
shown in figure 2 is clearly evident.
Contributing areas to two hypothetical supply wells, shown in figure 3,
were delineated using the particle-tracking computer program for both the two-
dimensional and three-dimensional ground-water flow models. Particles were placed
at the water table of the simulated aquifer and their pathlines traced through the
model. The area defined by the starting locations of particles that reach a
particular supply well constitutes the well's contributing area. Several
simulations were completed to demonstrate the value of the technique in the
analysis of a multllayered stratified-drift aquifer with multiple pumped wells.
In the first six simulations, each well was pumped individually at three
separate pumping rates, 0.25 Mgal/d, 0.50 Mgal/d, and 1.0 Mgal/d (figure 6). The
results of the particle-tracking analysis indicate that the size of a well's
contributing area depends on the pumping rate at the well. Recharge from
precipitation to the stratified drift is the only source of water to these wells;
therefore, the area necessary to supply each well with water Is equal to Q/r.
This relation was verified for each simulation directly from the results of the
particle-tracking program. The simulations also agree with the observation made
from the results of the analytical model that the shape of a well's contributing
area depends on the location of the well with respect to the recharge and
discharge areas of the aquifer.
155
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N
•t
(b)
2 MILES
1
KILOMETERS
EXPLANATION
Contributing area for pumping rate of 0.25 Mgal/d.
Contributing area for pumping rote of 0.50 Mgal/d.
Contributing area for pumping rate of 1.00 Mgal/d.
• Location of hypothetical supply well.
Figure 6. Contributing areas for pumping rates of 0.25 Mgal/d, 0.50 Mgal/d and
1.00 Mgal/d for (a) well A and (b) well B, determined using the two-dimensional
ground-water-flow model.
The values of hydraulic conductivity and aquifer recharge used in the
development of a ground-water-flow model commonly are only best estimates of the
true field value. One way of evaluating the effects of uncertainties in the
estimates of these properties to the delineation of contributing areas is to
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complete a series of simulations in which the value of each property is varied
over what is felt to be a realistic range of values. As an example, three
simulations were run using the two-dimensional numerical model in which the
recharge rate to the aquifer was varied from 75 to 125 percent of the calibrated
value (figure 7). Because recharge from precipitation is the only source of water
to the well, the size of the well's contributing area is directly dependent on the
value specified for recharge. Figure 7 indicates that the value of aquifer
recharge specified in the model has a significant effect on the area that
contributes water to the well.
2 MILES
KILOMETERS
EXPLANAT ION
Contributing oreo for 75 percent of average recharge.
Contributing area for 100 percent of average recharge
Contributing area for 125 percent of average recharge.
• Location of hypothetical supply well.
Figure 7. Contributing areas to well A for recharge rate to the aquifer equal to
75, 100, and 125 percent of calibrated model value, determined using the two-
dimensional ground-water flow model.
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In order to investigate the effects caused by multiple pumped wells to the
delineation of recharge areas, a two-dimensional simulation was run in which both
wells A and B pumped simultaneously at a rate of 0.5 Mgal/d. The results of the
simulation are shown with the results of two simulations in which each well was
pumped individually at a rate of 0.5 Mgal/d (figure 8). The results indicate the
importance of considering simultaneously the effects of multiple wells on the
delineation of contributing areas. Contributing areas to two or more supply wells
can not overlap simultaneously because a particle of water that reaches the water
table can flow either to one of the wells or to a natural discharge area of the
system; it can not flow to more than one discharge point. The area of overlap in
the contributing areas shown in figure 8a is not possible.
2 MILES
0 1 2 KILOMETERS
EXPLANATION
Contributing area for well A.
Contributing area for well B.
• Location of hypothetical supply well.
Figure 8. Contributing areas to wells A and B for (a) each well pumped
independently at 0.5 Mgal/d and (b) both wells pumped simultaneously at 0.5
Mgal/d, determined using the two-dimensional ground-water flow model.
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Vertical and horizontal heterogeneities in aquifer properties can have a
significant effect on ground-water flow, and, therefore, would be expected to have
an effect on the location and shape of a supply well's contributing area. The
effect of aquifer heterogeneity to the delineation of contributing areas was
investigated using the three-dimensional numerical model by introducing a
discontinuous zone of material of low hydraulic conductivity, representative of
clay, in the vicinity of well B (figure 9). The simulated layer of clay was
placed in layer 2 of the model. The screened interval of the supply well was
located in layer 3 of the model and the well was pumped at a rate of 0.5 Mgal/d.
0
i—
0
2 MILES
KILOMETERS
EXPLANATION
Contributing area for well B.
Location of hypothetical supply well B.
Location of zone of low hydraulic conductivity.
Figure 9. Contributing areas to well B, for (a) simulation of the natural system,
and (b) simulation of a zone of clay in the vicinity of the well. Pumping rate is
0.5 Mgal/d.
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The results of the simulation (figure 9) show that the surface layer
contributing water to the well is greatly changed by the introduction of the
discontinuous zone of clay, which diminishes the rate of vertical movement of
water in the vicinity of the well. As can be seen in figure 9, the surface area
that contributes water to well B does not surround the well. Water which reaches
the water table in the vicinity of well B discharges to the natural boundary of
the aquifer (the Atlantic Ocean) downgradient of the well. The bifurcation of the
contributing areas shown in figure 9 is the result of spatial variations in both
the horizontal and vertical hydraulic conductivities in the third and fourth
layers of the model and the location of the eastern boundary of specified-head
cells. Pathlines of particles initiated at the water table in the row of the
model in which well B is located are also shown in cross section (figure 10).
These pathlines indicate the vertical flow path that particles of water follow
from the water table to discharge points at the well or the specified-head cells.
The results of figures 9 and 10 point to the importance to the determination of a
supply well's contributing area of defining accurately the lithology of an aquifer
in the vicinity of the well.
WELL
t
E
W
0
L
_L
J_
10
5000 feet
J I
20
34
COLUMN
SCALE GREATLY EXAGGERATED
EXPLANATION
Zone of low hydraulic conductivity
Specified-head cells
Screened-interval of well
Pathlines of particles discharged
at well
Pathlines of particles discharged
at specified-head cells
Figure 10. Cross-section of particle pathlines in row 28 for simulation in which a
zone of low hydraulic conductivity overlies the screened-interval of well B.
Pumping rate is 0.5 Mgal/d.
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Evaluation of delineation methods
A comparison between the contributing areas delineated for the two
hypothetical supply wells using the analytical model and the calibrated two- and
three-dimensional numerical models coupled with particle tracking is shown in
figure 11. The differences in the contributing areas delineated using the three
models are greatest at points farthest from the wells. The uniformity in the
horizontal and vertical hydraulic conductivities of the upper layers of this
aquifer produces similar results for the three methods. Part of the difference in
the recharge areas delineated using the three models is the result of differences
in the distribution of ground-water heads in each of the model aquifers. The map
of water-table altitudes used in the analytical model was constructed from field
data on ground-water heads. The water-table altitudes represent the average
response of the ground-water system to recharge, given the geologic framework and
natural boundary conditions of the aquifer. The distribution of heads simulated
by the numerical models are somewhat different than the field-derived map of
water-table altitudes because the models do not replicate exactly the real ground-
water system. Uncertainties in the understanding of the geologic framework of the
aquifer, recharge to the aquifer, and the boundary conditions of the aquifer
result in a distribution of ground-water heads that is only an approximation of
the natural system.
The three methods of analysis presented in this report for the delineation
of contributing areas to public supply wells completed in stratified glacial-drift
aquifers represent three levels of computational complexity that require
increasing levels of data specification. Each of the techniques has several
advantages and disadvantages which should be considered in the selection of a
method of analysis.
The primary advantage to using analytical models of ground-water flow is
that the models generally are computationally simple and require less data than do
numerical models. Data requirements for the analytical model discussed in this
report are a map of water-table altitudes, an estimate of the thickness and
hydraulic conductivity of the aquifer, and the discharge rate of the well. The
primary disadvantage of using analytical models is that they are based on
simplifying assumptions of the ground-water flow system. For instance, the
analytical model used in this report assumes that the aquifer is of infinite areal
extent, homogeneous and uniform in thickness. Additionally, simple boundary
conditions must be assumed, such as an impermeable boundary, an infinite boundary.
or a fully penetrating river boundary. In this report, it was necessary to assume
a distance at which drawdown produced by each well was known. Simplifications of
the hydrogeologic framework and boundaries of the ground-water system may result
in poor predictions of the contributing area to wells located in aquifers which
are arealy and vertically heterogeneous or contain complex natural boundaries.
However, for single wells pumping from uniform aquifers with simple boundary
conditions, the use of analytical models may be justified. Inspection of figure
11 indicates that the delineation of contributing areas to wells pumping from a
thin, single-layer, uniform aquifer, such as the aquifer underlying Eastham and
south Wellfleet, is not greatly enhanced by the use of the more complex numerical
models and particle-tracking algorithm.
161
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»t
,t
b)
2 MILES
0 1 2 KILOMETERS
EXPLANATION
Contributing area determined using analytical model.
Contributing area determined using two-dimensional numerical model.
Contributing area determined using three-dimensional numerical model.
tt Location of hypothetical supply well.
Figure 11. Comparison of contributing areas to (a) well A and (b) well B for
pumping rates of 0.5 Mgal/d, determined using different modeling approaches.
Numerical ground-water flow models coupled with particle tracking offer a
powerful computational tool for the analysis of supply-well contributing areas.
The primary advantage of using numerical modeling and particle tracking is that
these procedures provide a more detailed description than do analytical models of
the factors that affect the location and shape of contributing areas for wells
pumping from complex two- and three-dimensional aquifers. The disadvantage to the
numerical methods is the large amount of data that must be specified. Data
requirements include a map of ground-water altitudes for the aquifer, estimates of
recharge rates and hydraulic parameters throughout the aquifer, the specification
162
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of aquifer boundary conditions, and the location and rate of withdrawal of supply
wells. Furthermore, results of the numerical models are limited by the
understanding of the hydrogeologic framework of the aquifer, the accuracy of the
boundary conditions specified for the model, and the estimates of system
properties. In effect, the numerical models determine an exact solution to a
complex, yet ill-defined, two- or three-dimensional ground-water-flow problem.
However, the numerical models are not limited by as many simplifying assumptions
as are analytical models. The results of numerical models should improve an
understanding of the aquifer under study, and, in particular, help to
conceptualize the effect of a large-capacity supply well on ground-water flow.
This study has shown that particle tracking is of considerable aid in the
delineation of contributing areas in aquifers that are heterogeneous.
Summary
The delineation of contributing areas to public supply wells is an
important component of State and Federal strategies for the protection of ground-
water quality. The delineation of contributing areas requires first a conceptual
and second a quantitative understanding of the ground-water flow system in which
the well is located, so that predictions of the response of the system to the
pumping of a large-capacity supply well can be made. The identification within
the hydrogeologic environment of possible sources of water to a supply well is an
important first step in the development of a conceptual model of ground-water flow
in the study area and in the selection of a method of analysis for delineating a
well's contributing area.
A recent advance in the ability to analyze quantitatively ground-water flow
systems has been the coupling of particle-tracking algorithms to numerical ground-
water flow models. A demonstration of the use of this method for the delineation
of contributing areas to hypothetical supply wells pumping from a stratified
glacial-drift aquifer of Cape Cod, Massachusetts, has shown that (1) the location
of a well with respect to areas of recharge and discharge for the aquifer will
have a significant effect on the shape of a well's contributing area, (2) the
recharge rate to an aquifer and the pumping rate of a well will have a significant
effect on the size of a well's contributing area, (3) multiple pumped wells within
an aquifer must be considered simultaneously in the determination of a well's
contributing area, and (4) the lithology of the aquifer in the vicinity of a well
must be well defined.
The study also has shown that contributing areas determined using
analytical modeling were similar to those determined using numerical modeling
coupled with particle tracking for wells pumping from a thin, single-layer,
uniform aquifer with simple boundary conditions, and that the use of numerical
models for the delineation of contributing areas for wells in such an aquifer may
not be warranted. However, numerical modeling and particle tracking provide a
more powerful quantitative tool than do analtyical models for conditions normally
encountered in the field, such as thick, heterogeneous aquifers with complicated
boundary conditions in which several wells are pumped simultaneously. Under these
conditions, analytical models are not capable of providing sufficient detail to
predict accurately the land area that contributes water to a well.
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References
Davis, S.N. and R.J.M. DeWeist, 1966, "Hydrogeology", John Wiley and Sons, New
York, New York, pp. 201-203.
Freeze, R.A. and J.A. Cherry, 1979, "Groundwater", Prentice-Hall, Englewood
Cliffs, New Jersey, pp 168-172.
Guswa, J.H. and D.R. LeBlanc, 1986, Digital models of ground-water flow in the
Cape Cod aquifer system, U. S. Geological Survey Water-Supply Paper 2209, p. 6.
Kruseman, G.P. and N.A. de Ridder, 1983, "Analysis and evaluation of pumping test
data",Bulletin 11, International Institute for Land Reclamation and Improvement,
The Netherlands, pp. 104-107.
LeBlanc, D.R., J.H. Guswa, M.H. Frimpter, and C.J. Londquist, 1986, Ground-water
resources of Cape Cod, Massachusetts, U. S. Geological Survey Hydrologic Atlas
692, 4 plates.
McDonald, M.G. and A.W. Harbaugh, 1988, A modular three-dimensional finite-
difference ground-water flow model, U. S. Geological Survey Techniques of Water-
Resources Investigations, Book 6, Chapter Al, 586 pp.
Morrissey, D.J., 1987, Estimation of the recharge area contributing water to a
pumped well in a glacial-drift, river-valley aquifer, U. S. Geological Survey
Open-File Report 86-543, 60 pp.
Newsom, J.M. and J.L. Wilson, 1988, Flow of ground water to a well near a stream
Effect of ambient ground-water flow direction, Ground Water, vol. 26, no. 6, pp
703-711.
Pollock, D.W., 1988, Semianalytical computation of path lines for finite-
difference models, Ground Water, vol. 26, no. 6, pp 743-750.
Reilly, T.E., O.L. Franke, and G.D. Bennett, 1984, The principle of superposition
and its application in ground-water hydraulics, U. S. Geological Survey Open-
File Report 84-459, 36 p.
van der Heijde, P. and M.S. Beljin, 1988, Model assessment for delineating
wellhead protection areas, U. S. Environmental Protection Agency, Office of
Ground-Water Protection, 271 pp.
U.S. Environmental Protection Agency, 1987, Guidelines for delineation of wellhead
protection areas, U. S. Environmental Protection Agency, Office of Ground-Water
Protection, pp. 4-1 4-32.
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DEVELOPMENT OF AQUIFER PROTECTION ZONES
AND EVALUATION OF CONTAMINATION POTENTIAL
IN TOWN OF CHELMSFORD MUNICIPAL WELLS
Donald W. Podsen and Charles F. Myette
Wehran Engineering Corporation
100 Milk Street
Methuen, Massachusetts 01844
Abstract
The Town of Chelmsford, Massachusetts, obtains its entire municipal water supply
from 22 groundwater wells. Periodic testing since 1979 has detected trace
concentrations of volatile organic compounds in nearly all of the Town's municipal well
fields, with concentrations in excess of 50 ppb (total volatile organics observed) in
some wells. As a pilot study for protecting public water supplies in developed towns
in the Commonwealth of Massachusetts, the Department of Environmental Protection (DEP)
assigned Wehran Engineering the task of evaluating contamination that has been detected
in Chelmsford water supply wells. The study focused on delineating aquifer protection
zones around these wells, identifying potential past and present contamination sites
in these areas, and prioritizing these sites with respect to their potential to impact
the Town's water supply wells.
To provide a current assessment of the quality of Chelmsford's municipal water
supply, all accessible wells (18 of 22) were sampled in June, 1987 and analyzed for
volatile organic compounds. Analytical results at that time showed; a maximum of
15 ppb in one well, trace concentrations in two other wells, and either non-detectable,
or below detection limit, concentrations of volatile organic compounds in the remaining
wells.
Aquifer protection Zones I, II, and III were delineated for each of the municipal
supply wells in conformance with Massachusetts Division of Water Supply Guidelines.
A records search was conducted to identify and locate potential past or present
sources of contamination that might impact Chelmsford's municipal water supply wells.
A total of 121 potential contamination sites were identified and located. Of these
sites, none were located in Zone I areas, 81 were located in Zone II areas, and 40 in
Zone III. An additional 69 sites were identified, but could not be located.
A ranking system was developed to prioritize sites in terms of their potential
to contaminate municipal supply wells. The system is based on such factors as aquifer
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protection zone designation, relative distance within a zone from a well, the types
of chemicals potentially used, the volume of spills, and the ranking of watersheds
according to the degree of contamination that has been detected in wells. The ranking
system is designed to divide potential sites into groups, with each group assigned a
priority ranking relative to one another.
The 121 potential contamination sites that could be located were prioritized using
this ranking system. It was recommended that, in order to identify sources of
contamination that are impacting Chelmsford's municipal supply wells, preliminary site
assessments be conducted for potential sites in the highest priority groups. These
assessments are likely to reveal that many of these sites can be reassigned to lower
priority groups. Those sites, however, that are found to have a high potential for
contamination will be recommended for additional site investigations.
The DEP has acted on these recommendations by completing preliminary assessments
at over 15 of the highest priority sites. Based on the results of these assessments,
the DEP is currently planning a site investigation (with the installation of monitoring
wells and sampling of groundwater) at the highest priority site.
Introduction
Background
The Town of Chelmsford, Massachusetts, is an industrialized, suburban residential
community that obtains all of its drinking water from groundwater. Periodic testing
of groundwater in municipal supply wells since 1979 has detected trace concentrations
of volatile organic compounds in nearly all of the Town's well fields. As a pilot
study for protecting public water supplies in developed towns in Massachusetts, the
Department of Environmental Protection (DEP) assigned Wehran Engineering the task of
evaluating contamination that has been detected in Chelmsford water supply wells by
delineating aquifer protection zones surrounding the Town's municipal supply wells,
identifying potential past and present contamination sites in these areas, and
prioritizing these sites with respect to their potential to impact the Town's water
supply wells. Based on the results of this study, the DEP may conduct similar
investigations in other Massachusetts Towns.
The Town of Chelmsford covers approximately 22.5 square miles in areal extent
and is located in Middlesex County, Massachusetts. It is bordered to the north by the
Towns of Lowell and Tyngsborough, to the west by Westford, to the south by Carlisle,
and to the east by Billerica (Figure 1). In 1980, the population of Chelmsford was
31,174, and approximately 90 industrial building units were located in the Town.
Water in the Town is supplied by three privately owned water districts designated
as; the East, North and Central Districts. All commercial and industrial users, as
well as the majority of residents are supplied by these three districts. The remaining
residents obtain water from private wells. Presently, the three Districts have a
combined total of 22 supply wells (including one well (field) consisting of 49, 2-
1/2 inch tubular wells). Of these 22 wells, the North District operates 4 wells, the
East District operates 2 wells, and the Central District is responsible for the
remaining 16 wells.
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t
'RIVER MEADOW }
BROOK
WATERSHED
LEGEND:
• Municipal Well
Till / Bedrock
Stratified Drift
Groundwater Flow
Direction
Surface Water Divide
Town Boundaries
APPROXIMATE
SCALE. IN MILES
Figure 1. Site map showing Town of Chelmsford municipal water supply wells, associated watersheds
and distribution of stratified drift versus till/bedrock
-------
Laboratory analyses for volatile organic compounds in water collected from
Chelmsford municipal supply wells have been performed since 1979. Volatile organic
compounds (primarily chlorinated solvents) were detected in ten of the eleven well
fields. The chemicals most commonly reported were trichloroethylene and
tetrachloroethylene. In any given sampling round, volatile organic concentrations are
typically on the order of one to two parts per billion (ppb), or none detected. In
one well, however, a maximum of 340 ppb was detected.
Growth in the Town has been relatively uncontrolled with respect to allowing
development in some of the more environmentally sensitive groundwater recharge areas.
As a result, the contamination that is found in any one of the municipal supply wells
could be attributed to a number of potential contamination sources.
Purpose and Scope
The purposes of this pilot study are to delineate aquifer protection Zones I,
II, and III for each municipal supply well according to Massachusetts Division of Water
Supply Guidelines, to perform a records search to identify and locate potential past
and present sources of contamination in these zones, and to prioritize sites in terms
of their potential impact on the Town's water supply wells. The scope of this
investigation is limited to identifying contamination sources in only those areas that
impact Chelmsford public water supplies. The identification of contamination sources
is based solely on information obtained from the records search and does not include
additional site investigation activities. Furthermore, the delineation of aquifer
protection zones is based on available data only. Wehran identified significant
hydrogeologic data gaps prior to initiating the investigation, however, Wehran and DEP
agreed that it would not be cost- effective to acquire new data to fill these gaps.
Rather, it was decided that Wehran would utilize existing data and make assumptions
where necessary. These assumptions were made conservatively, so that the end result
would be to increase the size of Zone II areas relative to Zone III.
Hydrogeologic Setting
The boundary of the study area is defined by the surface water divides surrounding
the Town of Chelmsford's municipal wells/well fields, as obtained from drainage maps
prepared by the U.S. Geological Survey (USGS) in Boston, Massachusetts, (Figure 1).
This area covers approximately 45 square miles, and incorporates nearly the entire Town
of Chelmsford, small portions of the Towns of Lowell, Billerica, and Carlisle, and a
large portion of Westford. The study area is bordered to the north by the Merrimack
River and is located entirely within the watershed of that river. Figure 1 shows the
four major sub- basins, or watersheds, within the study area as defined by the USGS.
The major streams within each watershed (from west to east across the study area) are
Stony Brook, Black Brook, River Meadow Brook, and Hales Brook.
Groundwater in the study area occurs in three principle formations; 1) bedrock
underlying the entire area, 2) till deposits which overlie bedrock throughout most of
the area and which are exposed on hills and ridges (Baker, 1964), and
3) stratified-drift deposits which occur in valleys and on the lower slopes of
hillsides.
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Bedrock in the vicinity of Chelmsford is composed of a variety of Paleozoic
igneous and metamorphic rocks. Because these rock types are relatively impermeable
compared to the stratified-drift deposits, none of the Town's wells have been completed
in bedrock. Individual wells completed in bedrock typically yield 2-10 gallons per
minute (Brackley and Hansen, 1985).
Throughout most of the study area, bedrock is overlain by glacial till which has
an average thickness of fifteen feet. Due to the poor sorting of the till, wells
completed in these deposits generally yield less than 10 gallons per minute (Brackley
and Hansen, 1985).
In terms of groundwater resource potential, the stratified- drift deposits are
the most important stratigraphic unit in the Chelmsford area because they have much
higher hydraulic conductivity than either the bedrock or till. All municipal supply
wells in the Town of Chelmsford are screened in the stratified drift deposits. In
addition, the majority of private wells in Chelmsford and surrounding towns are
completed in this unit. Individual wells generally yield hundreds of gallons per
minute (Brackley and Hansen, 1985). These deposits are generally sorted and
stratified, and consist of sand and gravel with subordinate amounts of silt and some
boulders. The stratified drift deposits occur in river valleys and range in thickness
from less than one foot, where they pinch out against valley walls, to 140 feet in the
pre-glacial channel of the Merrimack River.
The general direction of groundwater flow is from upland areas to the east, west,
and south of the four major stream valleys towards the Merrimack River on the northern
border of the study area (Figure 1). The altitude of the water table ranges from
approximately 90 feet along the Merrimack River, to more than 250 feet at the western
edge of the study area (Feldman, 1978). The depth to the water table is generally less
than ten feet below land surface in low-lying areas and less than 30 feet below land
surface in hilly areas (Baker, 1964).
According to the Water District Superintendents, safe yield for the wells/fields
ranges from 250 to 700 gallons/minute and the average pumping rate for each well/field
ranges from 250 to 850 gallons/minute. It should be noted that not all wells are
continually pumping; in some cases a well is normally shut down while an adjacent well
is pumping, and vice versa.
Available boring logs for 12 of the 22 wells indicate that all wells are water
table wells, completed in an unconfined sand and gravel aquifer. Available pump test
data in the vicinity of the wells indicate transmissivities ranging from approximately
3,350 to 15,000 squared feet/day, saturated thicknesses of 40 to 65 feet, and average
hydraulic conductivities of 70 to 230 feet/day. The proximity of the wells to various
streams suggests that, depending on their pumping rate, they may cause significant
induced stream infiltration.
Current Groundwater Quality Assessment
One round of groundwater samples was collected from the Chelmsford municipal
supply wells by Wehran personnel on June 1st and 3rd, 1987. The samples were analyzed
for volatile organic compounds using USEPA Test Method 624.
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The analytical results show that one well (the well with highest concentrations
detected in the past) contains 15 ppb total volatile organics. Two other wells show
trace levels (<10 ppb) of volatile organic compounds (defined as less than 10 times
the detection limit), while the remaining wells contained either non-detectable, or
below detection limit (1.0 ppb), levels of volatile organic contamination.
Delineation of Aquifer Protection Zones
The Massachusetts Division of Water Supply has established guidelines (1986) for
the delineation of aquifer protection zones surrounding municipal supply wells,
referred to as Zones I, II and III (Figure 2). Zone I areas are defined as those
portions of aquifers which lie within a 400 foot radius of the wellbore. Because of
their close proximity, contamination sites in these areas have the greatest potential
impact on water quality in the wells.
Zone II is defined as "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 groundwater divides which result from pumping the
well and by the contact of the edge of the aquifer with less permeable materials such
as till and bedrock. At some locations, streams and lakes may form recharge
boundaries". The Guidelines specify the most severe recharge and pumping conditions
as pumping at safe yield for 180 days without recharge. Under these conditions, the
locus of 0.1 feet of drawdown is the predicted area of influence. These drawdowns are
then subtracted from the pre-pumped water table configuration, and subsequent analysis
of flow lines identifies the zone of contribution (Zone II area) for each well.
LEGEND:
*— Groundwater Flow Direction
-*- Water Table Surface
ZONE III
Surface Water
Divide
Till/ Bedrock
Stratified Drift
Water Supply Well
Figure 2. Conceptual block diagram of a stream valley illustrating Massachusetts
aquifer protection zones I, II and III in relationship to a pumping well.
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Zone III is defined as "that land area beyond the area of Zone II from which
surface water and groundwater drain into Zone II. The surface drainage area as
determined by topography is commonly coincident with the groundwater drainage area and
will be used to delineate Zone III. In some locations, where surface and groundwater
drainage are not coincident, Zone III shall consist of both the surface drainage and
the groundwater drainage areas".
Using these definitions, the delineation of the outer boundaries of Zones I and
II is relatively straight forward. After field verification of the well locations,
a line drawn at a radius of 400 feet around each well defines the outer boundary of
the Zone I area. The outer boundary of Zone III coincides with surface water divides
for the tributary. This information was obtained from drainage maps prepared by the
USGS.
The major effort associated with mapping aquifer protection zones is delineating
the boundary between Zones II and III. Defining this boundary first requires locating
the contact between the edge of the aquifer with less permeable materials
(till/bedrock). This geologic contact was obtained from the Hydrogeologic
Investigation Atlas of the study area (Brackley and Hansen, 1985) and is shown on
Figure 1.
The identification of "that area of an aquifer which contributes water to a well
under the most severe recharge and pumping conditions that can be realistically
anticipated" requires an evaluation of groundwater flow to the well. Because numerous
hydrogeologic variables affect groundwater flow, it is difficult to calculate this area
manually. As a result, a digital computer model was developed to perform the
calculations.
Two-dimensional groundwater flow models of the study area were designed and
calibrated to compute hydraulic-head changes in the stratified-drift aquifer under
natural and man-made stress conditions. For these models, Wehran utilized the USGS
three-dimensional groundwater flow model (MODFLOW) developed by MacDonald and Harbaugh
(1984).
The models use a finite-difference method in which differential equations that
describe groundwater flow are solved numerically. The equations require definition
of the geologic and hydrologic properties of the area modeled, the boundaries, and the
pumping stresses.
The study area was divided into two regions to simplify the modeling effort. A
finite-difference grid composed of equal size blocks (500 by 500 feet) was developed
for all areas underlain by stratified drift deposits. The active modeled area covers
approximately 14 square miles and includes over 1,500 active nodes.
Boring logs indicate that the stratified-drift deposits in both model areas are
unconfined aquifers overlying much less permeable till and bedrock. As a result,
although the computer model that was utilized has the capability of simulating a series
of layers within the aquifer (i.e., a three-dimensional flow model), both areas were
modeled as a two-dimensional single layer.
The groundwater flow models were calibrated under steady-state conditions.
Calibration consisted of adjusting input hydrologic parameters to the model until
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differences in water table elevation between model simulations and a groundwater
contour map of the area were within acceptable limits (i.e., within 10 feet over the
majority of the modeled area). A sensitivity analysis of the steady-state models was
then conducted to assess the limitations of the conceptual model and the uncertainty
in the selection of input data values and boundary conditions.
After calibrating the models under steady-state conditions, several transient runs
were made with each model to predict the areas of influence and zones of contribution
for the wells as a result of a specific stress on the aquifers. This stress is defined
by Division of Water Supply Guidelines as pumping at safe yield without recharge for
180 days. The computed steady- state heads for each model were used as starting heads
for each transient run. All wells were pumped simultaneously, and at safe yield, to
simulate worst-case conditions.
To evaluate the zones of contribution to the wells, the amount of drawdown caused
by pumping the wells at safe yield (with no recharge) was subtracted from the observed
heads, i.e., the average steady-state aquifer head distribution. On the downgradient
side of the pumping wells, the creation of localized groundwater divides (lines of
stagnation) where water flows back to the wells were predicted by the models. In these
areas, the model predicts that pumping the wells will cause the natural gradient and
direction of groundwater flow to be reversed causing groundwater to flow back towards
the well, in a direction that is contrary to the "natural" regional flow (Figure 2).
As a result, these local divides (lines of stagnation) form the downgradient margins
of the zones of contribution (Zone II) where contaminated groundwater could potentially
be directed towards the well. Analysis of flowlines was performed to extend the
upgradient boundaries of these capture zones to the hydrogeologic contact between the
stratified-drift deposits and till/bedrock. The zones of contribution (Zone II areas)
are then defined as the areal extent of stratified-drift deposits upgradient of these
boundaries. Inasmuch as the pumping stress was designed to simulate worst-case
conditions (i.e., all wells pumping simultaneously) the zones of contribution were
delineated for groups of wells as opposed to each individual well. Although this
analysis produces larger zones of contribution than if each well were pumped
separately, it provides a better simulation of aquifer protection as opposed to
considering only wellhead protection.
The aquifer protection zones delineated in this study for the Town of Chelmsford's
municipal water supply wells are shown on Figure 3. Zone I consists of the area within
a 400 foot radius around each wellbore. Zone II areas begin at the outer margin of
Zone I, and extend to the margin of the zone of contribution. The lines of stagnation
defining the downgradient margin of the zones of contribution is shown on Figure 3 for
various groups of wells. Zone III areas for each group of wells extends along
flowlines from the outer boundary of Zone II (contact between stratified-drift with
till/bedrock) to the watershed boundary. It should be noted that portions of Zones
II and III overlap between the various groups of wells. Specifically, within a given
watershed, the areas within Zones II and III for upgradient wells are included in the
corresponding Zones of all downgradient wells. Therefore, moving downgradient within
a given watershed, Zones II and III become successively larger as they incorporate the
aquifer protection zones of all upgradient wells.
174
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Contaminant Sites:
a High Priority Sites
• Medium Priority Sites
A Low Priority Sites
LEGEND:
Hi Zone No. I
I ! Zone No. II
Zone No. Ill
V///M Outside Zone
Lines of Stagnation
Surface Water Divides
Chelmsford Town Boundary
Figure 3 Site map showing potential contamination sites in relation to acmif
associated lines of stagnation. For simplification, the 17 groupsidentified i
system Figure 4) have been assigned either a high, mediunf, o/lowpriority
high priority (Groups 1-7), mediu* priority (Groups 8-13), and low priority
APPROXIMATE
SCALE. IN MILES
--
Priority
-------
Identification of Potential Sources of Contamination
A records search was conducted to identify and locate past or present potential
sources of groundwater contamination that may impact Chelmsford's municipal supply
wells. This search addressed the area bounded by the watersheds of all the Town's
municipal supply wells, which includes the majority of Chelmsford and portions of the
Towns of Westford, Carlisle, and, Billerica.
The records search expanded upon a list that had been compiled by the DEP's
Northeast Regional Office based on their files of hazardous waste
violations/complaints. Wehran identified and located additional potential sites
through interviews with Town employees, reviewing Federal, State and Town files,
library searches, and a site reconnaissance survey. The site reconnaissance consisted
of visual observations made while driving along various streets in the study area.
It should be noted that no attempt was made to gain access to any potential sites that
were identified.
A total of 121 potential contamination sites were identified and located. The
majority of these sites fall into several broad categories; known spill sites,
facilities with past hazardous waste violations, National Pollution Discharge
Elimination System (NPDES) permit sites, landfills, industries or businesses that
typically use hazardous chemicals (i.e., dry cleaners), and gas stations.
A table with brief descriptions of each potential contamination site was compiled;
however, because the records search was based on available information, as opposed to
site assessments, many site descriptions are incomplete. In particular, it often was
not possible to identify the type of operation, the types of chemicals that were used
and/or stored, or precisely when a facility was in operation.
A total of 69 potential contamination sites could not be located. The majority
of these sites have gone out of business and documentation regarding their location
was not readily available. An attempt was made to locate the more recent sites during
the site reconnaissance survey.
It should be noted that because the organic compounds that have been detected in
the water supply wells are chlorinated solvents, the records search placed less
emphasis on types of operations that would utilize different types of chemicals. In
particular, it was not considered cost-effective to attempt to identify the locations
of all underground petroleum storage tanks in the study area.
Prioritization of Potential Contamination Sites
Priority Ranking System
The records search identified and located a total of 121 potential contamination
sites which are distributed as follows; no sites in Zone I, 81 sites in Zone II, and
40 sites in Zone III. Because future site assessments may be conducted as a first step
in eliminating these potential sources of contamination, a system has been developed
to rank the sites in terms of their potential health impact on the Town's water supply
wells. It should be noted that because chlorinated solvents are the types of compounds
that have been detected in the water supply wells, the ranking system places higher
176
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priority on sites which may have potentially used chlorinated solvents. The system
is designed to divide the sites into groups, with each group assigned a relative
ranking, from highest (Group 1) to lowest priority (Group 17). The 69 additional
potential contamination sites that were identified, but which could not be located were
excluded from the priority ranking system.
Figure 4 is a flow chart which summarizes the ranking system. The first criteria
used to rank the sites is the determination of whether they are located in Zones I,
II, or III. Any site located in Zone I is assigned to the highest priority group
(Group 1) because these sites are located within 400 feet of a well. In general, Zone
II sites have the next highest priority, because they lie within the zone of
contribution and there is a high potential for contaminants to flow into wells.
However, as shown on Figure 4, several types of Zone II sites are considered to have
lower priority than some Zone III sites. Such Zone II sites include those which are;
1) located more than 15,000 feet from any supply well because of the potential for
substantial dilution and degradation of a contaminant release (Group 16), 2) highly
unlikely to have used chlorinated solvents (Group 14), and 3) spill sites where very
low volumes (less than 30 gallons) were released (Group 14).
The remaining Zone II sites are divided into Gr-oups 2 through 7. These sites are
first subdivided according to watershed, based on the amount of contamination that has
been detected by laboratory analysis in water supply wells within a particular
watershed. Past and present analytical data indicate that wells in the River Meadow
Brook watershed have been more affected by contamination than wells in the other
watersheds. Several wells in the Hales Brook and Stony Brook aquifers have shown minor
contamination, therefore, Zone II sites in these watersheds have lower priority than
Zone II sites in the River Meadow Brook watershed. Similarly, Zone II sites in the
Black Brook watershed have lowest priority, because the one well in this watershed has
shown only trace levels of contamination. Within each watershed, sites that are known
to have used chlorinated solvents are assigned a higher priority than sites that have
only the potential to have used these compounds. It should be noted that because of
the limited nature of the data collected in the records search, for many sites it is
not possible to rule out the potential for use of chlorinated solvents. For example,
gas stations were included in these high priority groups because of the potential that
chlorinated solvents were used in automotive repair work (degreasing, painting, etc.)
Similarly, industries that use chlorinated solvents in the manufacture of certain
products were included in high priority groups even though, in some cases, it is
unknown whether the site was used for manufacturing, or purely retail purposes. A
preliminary assessment that includes interviews with officials of various facilities
may indicate that chlorinated solvents were never used at many sites, in which case
those sites could be reassigned to a lower priority group.
Because of their location, some Zone III sites were given higher priority than
the Zone II sites in Groups 14 and 16. The criteria used to select these Zone III
sites was that they were located in close proximity to a Zone II boundary (less than
1000 feet), and within 10,000 feet of a water supply well. Within this category, those
sites that were unlikely to have used chlorinated solvents, or which had spills of less
than 30 gallons, were given a low priority ranking (Group 15). The remaining Zone III
sites were then subdivided into Groups 8 through 13 using the same criteria that were
applied to the Zone II sites.
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POTENTIAL CONTAMINATION SITES
ZONE I
< 15.000'
from well
ZONE III
> 15.000'
from well
May contain
chlorinated
solvents
Yes I No
Spill > 30 gallons
Yes I No
RIVER MEADOW BROOK
WATERSHED
Known
solvents
HALES BROOK & STONY
BROOK WATERSHEDS
BLACK BROOK
WATERSHED
y
Less than 1000' from
Zone II Boundary and Less
than 10,000 from
Municipal Supply Well
Yes I No
May contain chlorinated solvents
Yes 1 No
Spill > 30 gallons
Yes No
RIVER MEADOW BROOK
WATERSHED
Known —...
solvents other
HALES BROOK & STONY
BROOK WATERSHEDS
BLACK BROOK
WATERSHED
y
Figure 4. Flowchart of priority ranking system of potential contamination sites
The system ranks respective sites from highest priority (Group 1) to lowest
priority (Group 17).
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Zone III sites located more than 1,000 feet from a Zone II boundary were assigned
to the lowest priority group (17) because of their low potential to impact wells. In
addition, Zone III sites located downgradient of lines of stagnation were assigned to
the lowest priority group because groundwater in these areas will not flow toward the
wells. These sites were included in the ranking, however, because they lie within the
watershed and could impact future supply wells.
Results of Prioritization
The priority ranking of the 121 sites into the 17 groups was based solely on data
obtained from the records search. Additional data which is subsequently obtained
regarding a particular site may require an adjustment in the relative priority group
to which a site has been assigned. Because of the limited nature of available data,
a conservative approach was utilized in the ranking of sites so that in general,
additional information will likely shift the priority ranking of many sites to a lower
group.
To simplify the presentation of results, sites in the 17 priority ranking groups
have been assigned either a high, medium, or low priority as follows: high priority
(groups 1 through 7), medium priority (groups 8 through 13), and low priority
(groups 14 though 17). As shown on Figure 3, all high priority sites are located in
Zone II areas, however, some Zone II sites are ranked as low priority. In general,
the majority of low priority sites are located in Zone III, or in a Zone II but many
miles upgradient of municipal supply wells.
Summary and Conclusions
The objectives of this investigation were to evaluate contamination that has been
detected in the Town of Chelmsford's municipal water supply wells by assessing the
current quality of water in the wells, delineating aquifer protection zones around
these wells, identifying potential past and present contamination sites in these areas,
and prioritizing these sites with respect to their potential to impact the Town's water
supply wells.
Eighteen of the Town of Chelmsford's twenty-two water supply wells were sampled
and analyzed for volatile organic compounds. Analytical results showed that the
highest levels of contamination were 15 ppra in one well, trace amounts of contamination
in two wells, and the remaining wells contained either non-detectable, or below
detection limit, levels of volatile organic contamination.
Aquifer protection Zones I, II, and III were delineated for the municipal supply
wells (in conformance with Massachusetts Division of Water Supply Guidelines) using
existing hydrogeologic data.
Well locations were field checked during collection of groundwater samples, to
confirm the location of Zone I areas (400 foot radius around each wellbore). Zone II
areas were delineated utilizing the USGS three dimensional groundwater flow model to
predict the zones of contribution to the wells based on 180 days of continuous pumping
with no recharge. Zone III areas were delineated through the use of the USGS
Hydrologic Investigations Atlas of the area, USGS watershed boundary information, and
the results of the Zone II analysis.
179
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A records search was conducted to identify and locate potential past or present
sources of contamination that might impact Chelmsford's municipal supply wells. A
total of 121 potential contamination sites were identified and located. Of these
sites, none were located in Zone I, 81 were located in Zone II, and 40 in Zone III.
An additional 69 sites were identified, but could not be located.
A ranking system was developed to prioritize sites in terms of their potential
to contaminate municipal supply wells. The system is based on such factors as aquifer
protection zone designation, relative distance within a zone from a well, the types
of chemicals potentially used, the volume of spills, and the ranking of watersheds
according to the degree of contamination that has been detected in wells. The system
is designed to divide potential sites into 17 groups, with each group assigned a
priority ranking relative to one another. Using this system to rank the 121 potential
contamination sites in Chelmsford indicated that some Zone II sites have lower priority
than some Zone III sites.
Recommendations
Based on the results of this investigation, Wehran Engineering makes the following
recommendations for additional work in the evaluation of the contamination potential
of Chelmsford's municipal supply wells, and for the future protection of those wells
and their associated aquifers.
1. To identify sources of contamination that are currently impacting
Chelmsford's municipal water supply wells, preliminary assessments should
be completed for all high priority sites. These assessments would consist
of a records search, site visit, and possibly, interviews with officials of
the facility. Because the ranking of sites was made conservatively using
limited available data, it is anticipated that many of these high priority
sites will be reassigned to lower priority groups based on the results of
the preliminary assessments.
2. After conducting preliminary assessments, it is recommended that those sites
that remain in high priority groups be further evaluated with site
investigations. These investigations will include the compilation of a
detailed site history with some sampling and analysis. The results of such
an investigation will provide the data necessary to further evaluate whether
a particular site is potentially impacting any of the Town's municipal supply
wells and whether there will be a need for either monitoring or some form
of remediation.
3. The Town of Chelmsford should utilize the aquifer protection zones that have
been delineated in this study for future land use planning and water supply
siting.
4. With regard to aquifer/wellhead protection, this pilot study should be
expanded to include the following. First, there should be an educational
program at the local level to explain the need for aquifer protection.
Second, there should be coordination between various groups such as planners,
lawyers, public health officials and water resource specialists in the
development of groundwater protection strategies. These strategies would
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typically involve modifying existing towns by- laws or creating new aquifer
protection overlay districts. The intent of these by-laws would be to
prohibit certain types of development or activities in the more sensitive
groundwater recharge areas, or to place specific performance standards on
those developments. Finally, this pilot program should be expanded to other
industrial towns that are dependent upon groundwater resources. The same
general approach used in this pilot study can be applied to other States
that have different aquifer protection zoning systems, providing those
systems are based on hydrologic principals.
References
Baker, J.A., 1964, Groundwater resources of the Lowell area, Massachusetts:
U.S. Geological Survey Water Supply Paper 1669-Y, 37 pp.
Brackley, R.A., and Hansen, B.P., 1985, Hydrogeology and water resources of tributary
basins to the Merrimack River from Salmon Brook to the Concord River,
Massachusetts: U.S. Geological Survey Hydrologic Investigations Atlas HA-662, 3
pi., 1:48,000.
Feldman, L., 1978, Groundwater resources of Chelmsford, Massachusetts: Boston
University, unpublished PhD dissertation, 242 pp.
McDonald, M. G., and Harbaugh, A. W., 1984, A modular three-dimensional
finite-difference groundwater flow model: U.S. Geological Survey Open File
Report 83-875, 551 pp.
Massachusetts Division of Water Supply, 1986, Hydrogeologic study requirements for
delineation of Zone II and Zone III for new source approvals, 10 pp.
Biographical Sketches
Donald W. Podsen
Wehran Engineering Corporation
100 Milk Street
Methuen, Massachusetts 01844
Donald W. Podsen is a senior geologist with Wehran Engineering Corporation in
Methuen, Massachusetts, where he has been employed for four years. Before joining
Wehran, Mr. Podsen worked in petroleum exploration with ARCO Alaska, for five years.
He has a B.A. in geology (1977) from the University of Vermont and an M.S. in geology
(1981) from the University of Colorado. Since working at Wehran, Mr. Podsen has been
the project manager of numerous hydrogeological investigations of hazardous wastes.
He is a Certified Professional Geologist with the American Institute of Professional
Geologists.
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Charles F. Myette
Wehran Engineering Corporation
100 Milk Street
Methuen, Massachusetts 01844
Charles F. Myette is the Manager of Hydrogeological Services with Wehran
Engineering Corporation in Methuen, Massachusetts where he has been employed for the
past three years. Prior to joining Wehran, Mr. Myette worked 10 years with the Water
Resources Division of the U.S. Geological Survey in Minnesota and Massachusetts as
project manager of numerous hydrogeologic investigations specializing in water resource
management and groundwater flow modeling. He has a M.A. in Hydrology (1977) from the
University of New Hampshire. Since joining Wehran, Mr. Myette has been an expert
witness and project manager of numerous hazardous waste investigations.
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DETERMINING THE DEVELOPMENT POTENTIAL WITHIN WELLHEAD
PROTECTION AREAS AND RESULTING IMPACTS FROM
NITROGEN LOADING
Scott W. Horsley
Christine A. Coughanowr
Mark Nelson
Jon D. Wit ten, AICP
Horsley Witten Hegemann, Inc.
Water Resources Consultants
Cambridge, MA 02139
INTRODUCTION
Considerable progress has been made over the past decade
concerning the delineation of wellhead protection areas (WHPA's).
Protection zones based upon fixed radii have evolved into more
accurate approximations of zones of contribution to pumping
wellfields based upon sophisticated modelling approaches.
Protection strategies for WHPA's have included the development of
overlay zoning districts within which specific potentially
hazardous land uses are prohibited. Such uses may include
landfills, industries or businesses using or producing hazardous
materials, underground fuel storage tanks, sewage treatment
plants, salt storage areas and so forth. Another common approach
in protecting wellhead protection areas has been to require
Environmental Impact Reports for large proposed development
projects which exceed specific thresholds. Project proponents are
usually required to evaluate potential impacts of such large-scale
projects in excruciating detail.
Although these protection strategies are important, they do not
address cumulative impacts of land development within wellhead
protection areas over time. Ground water contamination from
dispersed, non-point residential and agricultural uses can
contaminate public water supplies as effectively as a poorly-sited
landfill. A recent case study on Cape Cod, Massachusetts has
documented a clear correlation between housing densities and
nitrate-nitrogen concentrations in ground water (Nelson et al,
1988). See Figure 1.
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HOUSING UNITS TO OBSERVED NITROGEN CONCENTRATIONS
1960
1965 1970
if HOUSING UNFTS/TIMESTEP
1975
1980 1985
TOTAL INORGANIC N
Figure 1
The approach which is outlined in this paper is a methodology for
examining the cumulative effects of land development within WHPA's
and is comprised of two principal steps: 1) determination of the
development potential; and 2) prediction of the resulting nitrate-
nitrogen concentrations.
DETERMINING THE DEVELOPMENT POTENTIAL
Clearly the first consideration in impact assessment within
wellhead protection areas is the delineation of accurate wellhead
protection area boundaries within which the analysis will be
conducted. A variety of methods have been developed to accomplish
this, ranging from drawing fixed radii around a wellfield, to
mapping based on detailed hydrogeologic field investigations and
modelling. An in depth discussion of appropriate delineation
techniques is beyond the scope of this paper, however, the
importance of an accurate delineation cannot be overemphasized.
Delineation of wellhead protection areas based on fixed radii are
not appropriate for assessing cumulative impacts; some site-
specific hydrogeologic data are required for a meaningful
analysis. In addition to existing public wellfields, potential
water supplies and areas used extensively for private water
supplies should also be considered in a comprehensive aquifer
protection strategy.
Once an accurate understanding of the ground-water flow dynamics
and the WHPA is developed an land use analysis must be undertaken.
The land use analysis should first determine the type, intensity
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and distribution of existing land uses. This can best be
accomplished utilizing assessors' tax maps, aerial photographs and
field checking. This analysis is then supplemented by determining
the development potential of all vacent parcels within the WHPA.
This is done by evaluating the highest development potential of
each parcel according to existing zoning, subdivision and other
land use codes. Wetlands and soil limitations should be
considered during this analysis. Certain parcels may have
permanent conservation restrictions or easements as restricted
open space and therefore should be considered undevelopable.
State land use enabling legislation throughout the country
dictates that once a community programs itself through zoning and
subdivision control, it is tied into a development "blueprint"
which is difficult to alter. Unfortunately, this blueprint often
allows for land development that exceeds the assimilative capacity
of drinking water supplies with respect to a variety of
contaminants, particularly nitrate-nitrogen.
A particularly difficult issue to resolve, in controlling land use
within WHPAs is that of "grandfathered" lots. Most zoning bylaws
and ordinances allow for significant protection of subdivided but
still vacant land from proposed zoning changes. In Massachusetts,
for example, once a preliminary subdivision plan has been filed
with the local planning board, the property owner is protected
from any new zoning changes for a period of 7 years. If during
that time, individual lots are sold to different property owners,
the right to build upon these lots may be protected indefinitely.
Consequently, WHPAs may contain a significant number of small,
vacant lots, which, if developed, could result in significant
contamination of the water supply.
The total development potential of the WHPA is determined by
summing existing development and future potential development.
This calculation will result in a quanitification of the
"saturation" development or "build-out" population. An
illustration of this analysis is provided in Figure 2.
CALCULATING THE NITROGEN LOADING
Once the developable lot analysis has been completed all potential
sources of nitrogen are assessed and tabulated. These sources
typically include wastewater, residential and agricultural
fertilizers, road run-off and precipitation. Several analytical
models have recently been developed to predict nitrate-nitrogen
concentrations in ground water using a mass balance approach
(Nelson et al 1988; Frimpter et al, 1988) . These models predict
nitrate-nitrogen concentrations in ground water by dividing the
annual nitrogen loading from the various sources by the annual
dilution due to natural and artificial ground-water recharge. The
primary source of error in these analytical methods has been in
the assumed nitrogen loading and dilution values used in the
model. To test and verify the conventional nitrogen loading
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LEGEND
DEVELOPED LAND
SUBDIYTOABLE/DEVELOPABLE LAND
RESTRICTED OPEN SPACE
CATEGORY
Developed land
Subdividable/Developable Land
Restricted Open Space
Total
ACRES
31
337
243
611
UNITS
95
219
-
314
2. Developable Lot Analysis of a Wellhead Protection Area
186
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variables typically used, the authors recently developed an
analytical model which was calibrated using actual water quality
data collected on Cape Cod, Massachusetts over a 25-year period
(Nelson et al., 1988) . This model was presented at the NWWA FOCUS
Conference in 1988. The results of this nitrogen loading
analysis, when applied to the WHPA depicted in Figure 2, are
presented in Table 1. This analysis shows that under saturation
development conditions a nitrate-nitrogen concentration is
predicted.
The results of the nitrogen loading assessment are then compared
to acceptable nitrate-nitrogen concentrations within ground water.
The US EPA has established standard of 10 mg/L for nitrate-
nitrogen concen-trations in drinking water; concentrations above
this limit may cause health problems in infants. Using this
standard as a planning guideline is not recommended however. A
statistical analysis of drinking water samples collected on Long
Island revealed that median nitrate-nitrogen concentrations of
less than 5.4 mg/L are required to meet the 10 mg/L federal
drinking water standard 90% of the time (Porter, 1978). Many
communities in Massachusetts have therefore adopted a 5 mg/L
nitrate-nitrogen standard as a conservative planning guideline.
TOOLS FOR CONTROLLING NITROGEN LOADING WITHIN WHPA'S
If the "programmed" development (existing development plus
potential growth) within a WHPA exceeds the assimilative capacity
of the water supply, a variety techniques can be used to mitigate
for existing development and control future growth to achieve
acceptable nitrate-nitrogen concentrations. These techniques can
be grouped into three categories: regulatory, non-regulatory and
legislative approaches (Coughanowr et al, 1989).
Regulatory techniques include zoning, subdivision control and
sewage disposal regulations and are generally implemented at the
local governemntal level. Examples include raising the minimum
lots size or limiting the amount of sewage per lot area. These
techniques are often highly effective in that they can be tailored
to meet*'the physical and political needs of specific communities.
However, grandfathering provisions within zoning codes limit their
effectiveness as noted earlier in this paper.
Non-regulatory techniques include the aquisition of open space and
and structural solutions such as sewering or construction of
private sewage treatment plants. These approaches are often
costly and may be more appropriately used where regulatory
techniques are not sufficient to control growth or where existing
development already exceeds the carrying capacity of the aquifer.
Legislative techniques refer to the establishment of special
legislation where existing legal authority is inadequate.
Examples include cases where wellhead protection areas or aquifer
recharge zones cross jurisdictional boundaries. Special
legislation may be required based upon a "hydroregional" approach
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TABLE 1
NITROGEN LOADING CALCULATIONS UNDER SATURATION BUILD OUT CONDITIONS
Project: Sample Wellhead Protection Area
Date: 21 July, 1989
INPUT FACTORS
Sewage flow (gal/day)
N-conc. in effluent (mg/1)
Lawn area (square feet)
Pavement (square feet)
Roof area (square feet)
Natural area (square feet)
Recharge rate for pervious
area (in/yr)
Recharge rate for impervious
area (in/yr) *
1
103620 I
I 33.9 |
1
1
1
1
1
1 '
3140000 |
1269629 I
628000 |
23147531 |
18 I
40 I
INPUT
CALCULATIONS
RESULTS
Sewage (gal/day)
103,620
Lawn area (sq ft)
3,140,000
Pavement area (sq ft)
1,269,629
Roof area (sq ft)
628,000
Natural area (sq ft)
23,147,531
Recharge from sewage (eal/day)
103,620
Total pervious area (sq ft)
26,287,531
Total impervious area (sq ft)
1,897,629
x N-conc (mg/1) x 3.785 1/gal x 365 days/yr : 454000 mg/lb
x 0.0017 IbN/sq ft
x 0.00031 IbN/sq ft
x 0.00015 IbN/sq ft
x 0.000005 IbN/sq ft
TOTAL NITROGEN LOADING (LBS/YR)
x 365 days/yr : 1,000,000 gal/million gal
x 18 in/yr /12 in/ft x 7.48 gal/cu ft : 1,000,000 gal/million gal
x 40 in/yr /12 in/ft x 7.48 gal/cu ft : 1,000,000 gal/million gal
TOTAL RECHARGE (MGAL/YR)
TOTAL NITROGEN LOAD/TOTAL RECHARGE X 454,000 MG/LB : 3.785.000 L/MGAL
•RECHARGE NITROGEN CONCENTRATION (mg/1 or ppm
CALCULATED LOADING (LBS/YR)
10689
5338
394
94
116
16631
TOTAL RECHARGE (MG/YR)
37.82
294.95
47.31
380.08
5.25
PREPARED BY HORSLEY WITTEN HEGEMANN, INC.
188
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where a new management commission may be created to regulate land
uses within the newly delineated area.
REFERENCES
Coughanowr, Christine A., Witten, Jon D., and Horsley, Scott W.,
"Cumulative Impacts of Land Development Within Wellhead
Protection Areas: Assessment and Control", National Water Well
Association Proceedings Focus on Eastern Regional Ground Water
Issues, 19 October 1989.
Frimpter, Michael H., Douglas, S.J., and Rapacz, M.V., "A Mass-
Balance Nitrate Model for Predicting the Effects of Land Use on
Groundwater Quality in Municipal Wellhead Protection Areas",
Commonwealth of Massachusetts, July 1988.
Nelson, Horsley, Cambareri, Giggey and Pinette. "Predicting
Nitrogen Concentrations in Ground Water - An Analytical Model,"
National Water Well Association Proceedings Focus on Eastern
Ground Water Issues, 27-29 September 1988.
Porter, K.S., "Nitrates" in The Long Island Comprehensive Waste
Treatment Management Plan: VII Summary Documentation, Long
Island Regional Planning Board, Hauppauge, New York (1978) .
BIOGRAPHICAL SKETCHES
Scott W. Horsley, Horsley Witten Hegemann, Inc., P.O. Box
7, 3179 Main Street, Barnstable, MA 02630
Scott Horsley is Vice President of Horsley Witten Hegemann, Inc.
where he provides expert consultation in water quality science and
planning. He has prepared aquifer protection mapping and plans
for over three dozen local governments, has assisted in the
development of four sole source aquifer petitions and has served
as an expert witness in several court cases involving critical
water issues. He serves on National Water Well Association's
Aquifer Protection Committee and was a former member of the
Commonwealth of Massachusetts' Ground-Water Steering Committee.
Scott has authored numerous publications on ground-water resource
delineation and protection. Scott was employed under EPA-funding
with the Cape Cod Planning and Economic Development Commission
where he developed an analytical model and mapped critical zones
of contribution to 130 public supply wells throughout Barnstable
County, Cape Cod, Massachusetts. He holds a Master's degree from
the University of Rhode Island and a Bachelor of Science degree
from Southeastern Massachusetts University with academic training
in geology, biology, planning and environmental law. Scott is an
Adjunct Professor at Tufts University in Massachusetts.
Christine A. Coughanowr, Horsley Witten Hegemann, Inc.,
P.O. Box 7, 3179 Main Street, Barnstable, MA 02630
Christine A. Coughanowr is a hydrogeologist and partner with
Horsley Witten Hegemann, Inc. where she provides consultation in
189
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ground water, wetlands, and coastal processes. She has recently
developed a spread-sheet based methodology for assessing
cumulative impacts of nitrogen loading to ground and surface water
resources. Christine has a Bachelor of Science degree in geology
from Duke University and a Master of Science degree in geology
from the University of Delaware.
Mark Nelson, Horsley Witten Hegemann, Inc., P.O. Box 7,
3179 Main Street, Barns table, MA 02630
Mark Nelson is a hydrogeologist with Horsley Witten Hegemann,
Inc.. He has directed numerous projects delineating wellhead
protection areas, as well as critical ground water resource areas
surrounding lakes, coastal ponds, and estuaries. Together with
Scott Horsley, Mark has recently developed an analytical nitrogen
loading model used to determine land use impacts on ground water
quality. Mark has a Bachelors degree in geology from Brown
University and will receive a Masters degree in environmental
science and engineering from the Oregon Graduate Center in the
spring of 1990.
Jon D. Witten, Horsley Witten Hegemann, Inc., P.O. Box 7,
3179 Main Street, Barnstable, MA 02630
Jon Witten is President of Horsley Witten Hegemann, Inc. where he
directs the firm's land use planning program, and provides public
and private sector consultation in land use planning strategies.
he is currently assisting EPA's Office of Ground Water Protection
to develop training programs for state and local officials. Jon
has successfully authored several hundred local ordinances
designed to protect ground-water resources and developed a unique
regulatory approach for assessing the cumulative water quality
impacts of land development in sensitive water resource protection
areas utilizing a nutrient loading method. He has lectured
nationally on appropriate strategies to mitigate the impact of
land development on natural resources. Jon was the Planner and
Administrative Director for the Town of Falmouth, Massachusetts
for three years and has taught training courses on land planning
and development in Boston for the past four years. He has a
Master's degree in Regional Planning from Cornell University and
is certified by the American Institute of Certified Planners. Jon
is an adjunct assistant professor at Tufts University in
Massachusetts.
1.90
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EVALUATION OF LOCAL REGULATORY EFFORTS IN IDENTIFYING AND
CONTROLLING THE THREAT OF UNDERGROUND FUEL STORAGE TANKS
Charlotte Stiefel and George Heufelder
Barnstable County Health & Environmental Department
Superior Courthouse
Barnstable, Massachusetts 02630
Abstract
For the past two years, the Barnstable County Health and
Environmental Department, a regional advisory agency, has coordinated
a county-wide effort to assist towns in formulating an overall
underground storage tank (UST) management plan for groundwater
protection. Certain key elements for initiating a residential UST
program have been identified and include passage of a comprehensive
regulation, support of regional and local agencies and public education
initiatives. The level of regulation determines the overall reduction
of threat to the groundwater, as evidenced by number of tank removals.
When only registration of residential UST was required, up to 10% of the
residential UST are removed annually- Passage of a comprehensive UST
regulation which also includes testing and removal requirements resulted
in up to 18% tank removal. Reduction in the number of residential UST
can be greatly enhanced if the local municipality takes initiatives to
reduce the removal costs, such as allowing disposal at the local
landfill. Administration of an effective UST control program requires
a significant time commitment; in Barnstable County this has been
supplied at a regional level, with help from local fire and health
departments.
Regarding commercial UST, despite comprehensive state regulations,
over 20% of the tanks in the study area were not in compliance with
testing requirements. Local initiatives in the form of a single
notification letter resulted in an almost-immediate reduction of this
figure to 11%.
Introduction
Leaking underground storage tanks (UST) constitute one of the most
significant threats to groundwater quality in the United States. The
increased awareness of this problem is demonstrated by the number of
191
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state and federal UST regulations which have been adopted in the last
few years. A comprehensive wellhead protection program, however, should
also include local efforts at UST control.
In Barnstable County, Massachusetts (which includes the fifteen
towns comprising Cape Cod) the need for such regulation was underscored
by the 1977 contamination of Provincetown's public water supply from
leaking underground tank. Shaken by this catastrophe, many Cape towns
adopted local health regulations on UST in the early 1980's. These
regulations, like the present state/federal regulations, focused on
"commercial" tanks leaving many tanks exempt from strict controls. In
1986, the Barnstable County Health and Environmental Department (BCHED),
under funding from the US EPA Office of Underground Storage tanks, began
to assist towns in developing a comprehensive UST management program
which addresses not only the commercial installations but the remaining
threat of on-site (mostly residential) heating oil tanks.
The role of the Barnstable County Health & Environmental Department
is strictly advisory; we do not have the authority to mandate
residential UST regulation. Therefore, our approach has been to
encourage towns to adopt regulations and then assist them in
implementing a comprehensive UST management program. As might be
expected, our recommendations are followed to varying degrees among
different towns. This paper evaluates which aspects of a UST program
are the most effective and those factors to consider when instituting
various components. Also included is an analysis of the efficacy of
local efforts in the enforcement of the state/federal regulation of
commercial tanks.
Residential UST Program
The BCHED program includes the development and presentation of a
model Board of Health regulation, tank testing by soil-vapor analysis,
public education, data management and enforcement assistance.
The model regulation, which is included in Appendix A, covers
mandatory tank registration and tagging along with various installation,
maintenance, testing, spill/leak reporting and removal requirements.
Briefly, all heating oil UST are registered with the local health
department and given a numbered tag to attach to the fill pipe. Oil
distributors are then required to report unregistered tanks to the
health department. New installations are required to be double-walled
with interstitial space monitoring. Existing tanks must be tested at age
15 and annually after age 19 and removed at age 30. At this time, 11 of
the 15 Cape towns have revised their original UST regulations in
response to our recent efforts. As mentioned above, many towns have
revised or adopted only parts of the model regulation.
Under the EPA grant, BCHED developed a UST testing program involving
the use of soil-gas analysis as an easy and inexpensive method of
testing heating oil tanks. The method and materials used are explained,
in detail, in REGULATION AND TESTING OF RESIDENTIAL UNDERGROUND FUEL
STORAGE TANKS (Stiefel & Heufelder, 1988). Using this method, a
192
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residential tank can be tested at a first year cost of under $200;
testing in subsequent years would cost under $50. The existence of this
testing program was a very important factor in the acceptance of a
testing requirement on residential UST. Most Boards of Health would have
been reticent to impose expensive restrictions on "innocent" homeowners.
The inclusion of a testing requirement in a town's regulatory effort is
an important factor in the overall success of the program.
The public education efforts of BCHED are another important, though
unquantifiable, factor in the overall success of UST regulation in
Barnstable County. Efforts to speak to appropriate groups and,
especially, to members of the media are critical to the success of any
effort. Foremost, personnel in the fire and health departments must be
made aware of the threat, and, more importantly, be compelled to
alleviate the threat. This is often a problem; Boards of Health and fire
officials have so many responsibilities that they are sometimes
unwilling, or actually unable, to take on another project. In
Barnstable County, this problem was partially addressed by the
assistance that BCHED could supply under the auspices of the grant.
Regardless of the time spent, the philosophy of these departments is
very important. Statements made by local officials as to the importance
of tank testing and removal go a long way toward making it a reality.
Education of the general public is also essential. The average
tankowner must be convinced that the costs involved with testing and/or
removal of UST are outweighed by the protection these measures afford
to the groundwater. This education process must also extend to oil
dealers. Their first reaction, fear of losing customers, must be
alleviated by convincing them that cooperation with these regulatory
efforts is in the best interest of their customers. Since oil dealers
have the most complete information on the locations of UST, obtaining
their cooperation is essential. Many Cape oil dealers have agreed to
send form letters to their customers notifying them of the regulations
- this has proven to be the best way of getting the word out.
An additional BCHED activity offered to local UST management
programs is data management. Computer programs have been written which
allow rapid inquiry, sorting and listing of UST records, facilitating
the issuance of testing and removal notifications in an efficient and
economical manner. These programs were written in a commonly-used
database system and operated from a Personal Computer.
Results and Discussion
To determine which of the towns' programs were the most effective
at reducing the overall risk to groundwater and which components of the
program lead most to its success, we partitioned the towns' actions into
four "levels": registration, tagging and testing; registration and
tagging only; registration only (no oil-dealer participation in the
notification process); and those taking no action. The evaluation
criteria used is the number of tanks taken out of service and is based
on the assumption that a tank removed from service translates to a
reduction in the overall threat to groundwater.
193
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Figure 1 indicates the number of tanks taken out of service in each
of five of the nine towns which have accepted the full regulation.
These five towns were selected for analysis based on the ability to
obtain reliable tank-removal information for both pre-regulation and
regulation periods. The regulations in each of these towns were passed
during 1987 and became effective in the latter part of that year.
Therefore, 1988 is considered the first regulatory year in these towns.
These data are compared with that of five towns (Figure 2) which have
promulgated regulations requiring only registration of tanks (Dennis,
Harwich and Sandwich) or towns having no regulation at all (Eastham and
Yarmouth). These data show that there were greater increases in tank
removal activity in towns having a complete regulation compared with
towns which do not. Towns with a comprehensive regulation generally had
a 4-60 fold increase in tank removals across pre-post regulatory years
(Figure 1) and greater than 5% of the UST population taken out of
service each year (Table 1) . This compares with towns which do not have
a comprehensive regulation and generally exhibit less than a 5-fold
increase in activity across years 1986-1989 (Figure 2) and have less
than 5 % of the UST population removed each year (Table 1).
ORLEANS
BREWSTB*
IVsl 138"
UTTX 19B9
Figure 1 Numbers of residential UST taken out of service in
selected towns having comprehensive UST regulations. Barnstable
County, Massachusetts 1987-1989.
194
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1DO
ISO -
140 -
130 -
8 120-
> 110 -
B 100 -
80 -
BO -
70 -
60 -
30 -
40 -
30 -
20 -
10 -
27
iSH il --= i:>ia
DB*JIS H«iRWICH SANDWICH EASTHAM YARMOUTH
\7~7\ 1880 INNl 1987 V777X 19B8 [?^3 1989
Figure 2 Numbers of residential UST taken out of service in
selected towns without comprehensive UST regulations. Barnstable
County, Massachusetts 1986-1989. ND= no data.
Table 1: Percentage of total residential underground tanks removed in
the years 1986-1989. Numbers in parentheses represent the estimated
number of USTs present in 1987.
1987
1988
1989
Towns with comprehensive UST regulations
Orleans
(440)
.2%
14%
18%
Chatham
(380)
3%
13%
7%
Barnstable
(900)
2%
13%
16%
Falmouth
(650)
.6%
3%
5%
Brewster
(300)
2%
9%
6%
Towns without comprehensive UST regulations
1986
1987
1988
1989
Dennis
(305)
1%
2%
6%
10%
Harwich
(226)
ND
ND
2%
10%
Sandwich
(350)
ND
ND
1%
2%
Eastham
(325)
.6%
3%
4%
.7%
Yarmouth
(600)
.5%
1%
2%
3%
Total number of tanks is estimated, numbers removed are from fire
department records. ND= No data.
Among towns having a comprehensive regulation, there are differences
in the success of the program as evidenced by the number of tanks taken
195
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out of service. Although it is difficult to totally isolate those
factors which account for the success of residential UST programs, our
experience in nine towns allows us to draw some conclusions.
The most successful programs exist in the towns of Orleans and
Barnstable. Several factors contribute to the success in Orleans.
Foremost, since they were the first town to adopt the regulation, they
received maximum input from our department. Also, both the health and
fire departments made strong commitments toward addressing the economic
and regulatory issues associated with tank removal. In early 1987,
while the costs of removing tanks were high due to the absence of Cape
companies in this industry, officials in Orleans, following careful
research of the regulations involved, established policies and
procedures which minimized the costs to the average tankowner. In
short, Orleans encouraged individuals to take advantage of a two-year
abandonment period (following removal of product from the tank), which
spreads the costs of tank removal and replacement over a broader period.
In addition, this town allows the disposal of tanks at the local
landfill (a practice not allowed in some other Cape towns), thus
reducing the overall costs of removal.
The success of the program in Barnstable can largely be attributed
to the commitment of the town in terms of personnel and effort. This
town's hazardous waste specialist was designated the responsibility for
overseeing the UST program and some of the five town fire departments
are quite committed to the program. In addition, the health department
aggressively solicited the participation of the oil dealers in the
notification process. In the Town of Chatham, where there was an
intermediate level of success between Orleans and Barnstable, the
alternate was true. In this town, the fire department took the more
aggressive role in the enforcement of the UST regulation. In addition
to the supportive agencies in each of these three most-successful towns,
another factor, that of the economic level of the community, may come
into play in determining the overall number of UST removals. It is
interesting to note that the Cape towns exhibiting the highest estimated
per capita income levels are Orleans and Chatham (U. S. Bureau of the
Census, 1985) .
Among the Cape towns which opted to adopt only the registration
requirement of the UST regulation or which opted not to update their UST
regulation, there was, again, varying degrees of success in eliciting
removals. In the towns of Dennis and Harwich which have mandatory UST
registration (Dennis requiring oil-dealer participation in the
notification process), it is projected that nearly 10% of the UST will
be removed from service during 1989. When the Town of Harwich recently
adopted a comprehensive regulation, the fire department immediately
received numerous inquiries regarding tank removal. The experience in
Dennis and Harwich contrasts with that of Sandwich, Eastham and Yarmouth
which generally remove less than 5% of their tanks/year.
In summary, our experience indicates that a reduction in the threat
to groundwater is related to the level of regulation adopted. When there
was no residential UST regulation or public education program, we
196
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observed annual removal rates of 1% or less. The general public
education which occurs when there is an aggressive regional program
seemed to also benefit towns which did not adopt any regulation (1-4%
annual removal). Towns actively registering tanks, but having no further
regulation, had up to 10% of their UST removed annually. Adoption of
a comprehensive UST regulation resulted in an annual removal rate as
high as 18%. The most important factors in determining the success of
the UST program in Barnstable County were the support of a regional
agency, commitment of fire and health department personnel at the local
level and a public education effort. The acceptance of the
comprehensive regulation was significantly fostered by the development
and use of inexpensive testing and removal methods.
Commercial UST Program
Existing Massachusetts regulations (527 CMR 9.00 Tanks and
Containers) impose various restrictions on motor fuel UST. Part of
BCHED's program is to assist the local fire departments with the
enforcement of the sections which require these tanks to be registered
and to be tested at certain ages. Our experience in the last two years
has indicated that although compliance with the registration requirement
is quite good (99.5%), many tanks are not being tested as they should.
In the summer of 1989, visits were made to 15 of the 19 Cape fire
departments (at present, visits to remaining departments are being
arranged). Records on approximately 770 tanks were reviewed, updated,
and records of previous tightness tests were checked. Letters were then
sent to tank owner/operators whose fire department files did not show
appropriate tests. Of the 194 (25%) tanks in this category, 31 (16%)
responded with records showing either that the tanks had previously been
removed or that the required testing had been done. The reason for
inaccurate fire department records in these 31 cases could be because
the tank owner/operators were negligent in sending the information to
the fire departments, or because the fire departments lost/misplaced the
information. Of the remaining 163 tanks which still appear to have been
out of compliance at the beginning of the summer, owner/operators of 76
(47%) have responded to our letter with schedules for testing and/or
removal of the tanks. At the time of this writing, owner/operators of
87 tanks (53%) have yet to respond to our letter, however some
notifications have only recently been issued.
In summary, the passage of comprehensive state commercial UST
regulations does not mean, of itself, that the threat to groundwater has
been alleviated. Indeed, over 20% of the active commercial UST in our
area were out of compliance with state testing regulations prior to our
efforts. However, with a fairly-minimal effort such as sending a
reminder letter, a significant increase in compliance can be obtained.
References
Stiefel, C.L. and G.R. Heufelder. 1988. Journal of New England Water
Works Association, Volume 102(4): 254-266.
197
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Appendix
FUEL STORAGE SYSTEM REGULATIONS
Whereas, leaking fuel storage systems pose an immediate and serious
threat to Cape Cod's sole source aquifer, and,
Whereas, the Town of ( ) does not have records to locate all such
systems installed within the Town,
Therefore, under Chapter 111, Section 31, of the Massachusetts General
Laws, the( ) Board of Health hereby adopts the following regulation
to protect the ground and surface waters from contamination with liquid
toxic or hazardous materials.
DEFINITIONS: "Toxic or hazardous materials" shall be defined as
all liquid hydrocarbon products including, but not limited to, gasoline,
fuel and diesel oil, and any other toxic or corrosive chemicals,
radioactive materials or other substance controlled as being toxic or
hazardous by the Division of Hazardous Waste of the Commonwealth of
Massachusetts, under the provisions of Massachusetts General Laws,
Chapter 21C, Section 1, et. seq.
The following regulations apply to all toxic or hazardous material
storage systems:
Section 1. Installation of Fuel Storage Tanks
1-1. Following the effective date of this regulation, the installation
of all underground fuel, gasoline or other chemical storage tanks shall
conform with the following criteria: In that the United States
Environmental Protection Agency designated the Town of ( ) as
overlying a sole source aquifer, secondary containment of tank and
piping and an approved in-tank or interstitial space monitoring system
shall be required for new or replacement tanks.
1-2. Following the effective date of this regulation, all tanks
installed aboveground outside shall be of material approved for
outside use.
Section 2. Tank Registration
The following regulations shall apply to A) all underground tanks
containing toxic or hazardous materials as defined above which are not
currently regulated under 527 CMR 9.26 - Tanks and Containers, to B) all
tanks containing fuel oil, whose contents are used exclusively for
consumption on the premises, and to C) farm and residential tanks of
1,100 gallon capacity, or less, used for storing motor fuel for
non-commercial purposes.
2-1. Owners shall file with the Board of Health, on or before (
) the size, type, age and location of each tank, and the type of
fuel or chemical stored in them. Evidence of date of purchase and
installation, including fire department permit, if any, shall be
included along with a sketch map showing the location of such tanks on
198
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the property. Upon registering the tank with the Board of Health, the
tank owner will receive a permanent metal or plastic tag, embossed with
a registration number unique to that tank. This registration tag must
be affixed to the fill pipe or in such a location as to be visible to
any distributor when filling the tank and to any inspector authorized
by the Town.
2-2. Effective ( ) every petroleum and other chemical
distributor, when filling an underground storage tank, shall note on the
invoice or bill for the product delivered, the registration number
appearing on the tag affixed to the tank which was filled. Every
petroleum and other chemical distributor shall notify the Board of
Health of the existence and location of any unregistered or untagged
tank which they are requested to fill. Such notification must be
completed within two (2) working days of the time the distributor
discovers that the tank registration tag is not present.
2-3. Prior to the sale of a property containing an underground storage
tank, the fire department must receive from the current owner a change
of ownership form for the registration of the underground storage tank.
Such form can be obtained from the fire department.
Section 3. Testing
3-1. The tank owner shall have each tank and its piping tested for
tightness fifteen and twenty years after installation and annually
thereafter. A tank shall be tested by any final or precision test, not
involving air pressure, that can accurately detect a leak of 0.05
gal/hr, after adjustment for relevant variables, such as temperature
change and tank end deflection, or by any other testing system approved
by the Board of Health, as providing equivalent safety and
effectiveness. Piping shall be tested hydrostatically to 150 percent
of the maximum anticipated pressure of the system. Certification of the
testing shall be submitted to the Board of Health by the owner, at the
owner's expense. Those tanks subject to the testing requirements of
this regulation shall submit the certification of testing to the Board
of Health by ( ) . Tanks which are currently tested under the
provisions of 527 CMR 9.13 are exempt from this section. For purposes
of this section, tanks of unknown age are assumed to be 20 years of age.
Section 4. Maintenance of Fuel Storage Systems
4-1. All underground fuel lines which do not have secondary containment
shall be replaced with an approved double-containment system at which
time any service to the system requiring a permit is performed.
4-2. All above-ground elements of a fuel storage system shall be
maintained free of leaks and visible rust.
4-3. All in-tank or interstitial-space monitoring systems shall be
checked on a monthly basis to verify system integrity- Records of these
checks shall be sent to the Board of Health on an annual basis.
Section 5. Report of Leaks or Spills
5-1. Any person who is aware of a spill, loss of product, or unaccounted
for increase in consumption which may indicate a leak shall report such
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spill, loss or increase immediately to the head of the fire department
and to the Board of Health.
Section 6. Tank Removal
6-1. All fuel, gasoline or other chemical tanks not regulated under 527
CMR 9.00 (farm or residential tanks of 1,100 gallons or less and
underground tanks storing fuel for consumptive use at the property) in
service on the effective date of this regulation, shall be removed
thirty (30) years after the date of installation. If the date of
installation is unknown, the tank shall be assumed to be twenty years
old. All underground storage tanks currently subject to the removal
regulation (30 years or older) must be removed by ( ) .
6-2. Prior to the removal of an underground storage tank governed by
this regulation, the owner shall first obtain a permit from the head of
the fire department, pursuant toM.G.L., C. 148.
6-3, Any person granted a permit by the Marshal or the head of a local
fire department to remove a tank under the provisions of M.G.L., C. 148
or 527 CMR 9.00, shall within 72 hours provide the permit granting
authority with a receipt for delivery of said tank to the site
designated on the permit.
6-4. Before any person is granted a permit by the Marshal or the head
of a local fire department to remove a tank under the provisions of
M.G.L., C. 148 or 527 CMR 9.00, and said tank is not being transported
to an approved tank yard, the person requesting the permit shall provide
the permit-granting authority with written approval from the
owner/manager of the disposal site. (Reference: 502 CMR 3.00 for tank
removal and disposal procedure).
Section 7. Costs
7-1. In every case, the owner shall assume responsibility for costs
incurred necessary to comply with this regulation.
Section 8. Variances
8-1. Variances from this regulation may be granted by the Board of
Health after a hearing at which the applicant establishes the following:
(1) the enforcement thereof would do manifest injustice; and (2)
installation or use of an underground storage tank will not adversely
affect public or private water resources. In granting a variance, the
Board will take into consideration the direction of the ground water
flow, soil conditions, depth to ground water, size, shape and slope of
the lot, and existing and known future water supplies.
Section 9. Severability
9-1. Provisions of this regulation are severable and if any provision
hereof shall be held invalid under any circumstances, such invalidity
shall not affect any other provisions or circumstances.
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EVALUATION OF LOCAL REGULATORY EFFORTS IN IDENTIFYING AND
CONTROLLING THE THREAT OF UNDERGROUND FUEL STORAGE TANKS
Charlotte Stiefel and George Heufelder
Barnstable County Health & Environmental Department
Superior Courthouse
Barnstable, Massachusetts 02630
Abstract
For the past two years, the Barnstable County Health and
Environmental Department, a regional advisory agency, has coordinated
a county-wide effort to assist towns in formulating an overall
underground storage tank (UST) management plan for groundwater
protection. Certain key elements for initiating a residential UST
program have been identified and include passage of a comprehensive
regulation, support of regional and local agencies and public education
initiatives. The level of regulation determines the overall reduction
of threat to the groundwater, as evidenced by number of tank removals.
When only registration of residential UST was required, up to 10% of the
residential UST are removed annually. Passage of a comprehensive UST
regulation which also includes testing and removal requirements resulted
in up to 18% tank removal. Reduction in the number of residential UST
can be greatly enhanced if the local municipality takes initiatives to
reduce the removal costs, such as allowing disposal at the local
landfill. Administration of an effective UST control program requires
a significant time commitment; in Barnstable County this has been
supplied at a regional level, with help from local fire and health
departments.
Regarding commercial UST, despite comprehensive state regulations,
over 20% of the tanks in the study area were not in compliance with
testing requirements. Local initiatives in the form of a single
notification letter resulted in an almost-immediate reduction of this
figure to 11%.
Introduction
Leaking underground storage tanks (UST) constitute one of the most
significant threats to groundwater quality in the United States. The
increased awareness of this problem is demonstrated by the number of
201
-------
state and federal UST regulations which have been adopted in the last
few years. A comprehensive wellhead protection program, however, should
also include local efforts at UST control.
In Barnstable County, Massachusetts (which includes the fifteen
towns comprising Cape Cod) the need for such regulation was underscored
by the 1977 contamination of Provincetown's public water supply from
leaking underground tank. Shaken by this catastrophe, many Cape towns
adopted local health regulations on UST in the early 1980's. These
regulations, like the present state/federal regulations, focused on
"commercial" tanks leaving many tanks exempt from strict controls. In
1986, the Barnstable County Health and Environmental Department (BCHED),
under funding from the US EPA Office of Underground Storage tanks, began
to assist towns in developing a comprehensive UST management program
which addresses not only the commercial installations but the remaining
threat of on-site (mostly residential) heating oil tanks.
The role of the Barnstable County Health & Environmental Department
is strictly advisory; we do not have the authority to mandate
residential UST regulation. Therefore, our approach has been to
encourage towns to adopt regulations and then assist them in
implementing a comprehensive UST management program. As might be
expected, our recommendations are followed to varying degrees among
different towns. This paper evaluates which aspects of a UST program
are the most effective and those factors to consider when instituting
various components. Also included is an analysis of the efficacy of
local efforts in the enforcement of the state/federal regulation of
commercial tanks.
Residential UST Program
The BCHED program includes the development and presentation of a
model Board of Health regulation, tank testing by soil-vapor analysis,
public education, data management and enforcement assistance.
The model regulation, which is included in Appendix A, covers
mandatory tank registration and tagging along with various installation,
maintenance, testing, spill/leak reporting and removal requirements.
Briefly, all heating oil UST are registered with the local health
department and given a numbered tag to attach to the fill pipe. Oil
distributors are then required to report unregistered tanks to the
health department. New installations are required to be double-walled
with interstitial space monitoring. Existing tanks must be tested at age
15 and annually after age 19 and removed at age 30. At this time, 11 of
the 15 Cape towns have revised their original UST regulations in
response to our recent efforts. As mentioned above, many towns have
revised or adopted only parts of the model regulation.
Under the EPA grant, BCHED developed a UST testing program involving
the use of soil-gas analysis as an easy and inexpensive method of
testing heating oil tanks. The method and materials used are explained,
in detail, in REGULATION AND TESTING OF RESIDENTIAL UNDERGROUND FUEL
STORAGE TANKS (Stiefel & Heufelder, 1988). Using this method, a
202
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residential tank can be tested at a first year cost of under $200;
testing in subsequent years would cost under $50. The existence of this
testing program was a very important factor in the acceptance of a
testing requirement on residential UST. Most Boards of Health would have
been reticent to impose expensive restrictions on "innocent" homeowners.
The inclusion of a testing requirement in a town's regulatory effort is
an important factor in the overall success of the program.
The public education efforts of BCHED are another important, though
unquantifiable, factor in the overall success of UST regulation in
Barnstable County. Efforts to speak to appropriate groups and,
especially, to members of the media are critical to the success of any
effort. Foremost, personnel in the fire and health departments must be
made aware of the threat, and, more importantly, be compelled to
alleviate the threat. This is often a problem; Boards of Health and fire
officials have so many responsibilities that they are sometimes
unwilling, or actually unable, to take on another project. In
Barnstable County, this problem was partially addressed by the
assistance that BCHED could supply under the auspices of the grant.
Regardless of the time spent, the philosophy of these departments is
very important. Statements made by local officials as to the importance
of tank testing and removal go a long way toward making it a reality.
Education of the general public is also essential. The average
tankowner must be convinced that the costs involved with testing and/or
removal of UST are outweighed by the protection these measures afford
to the groundwater. This education process must also extend to oil
dealers. Their first reaction, fear of losing customers, must be
alleviated by convincing them that cooperation with these regulatory
efforts is in the best interest of their customers. Since oil dealers
have the most complete information on the locations of UST, obtaining
their cooperation is essential. Many Cape oil dealers have agreed to
send form letters to their customers notifying them of the regulations
- this has proven to be the best way of getting the word out.
An additional BCHED activity offered to local UST management
programs is data management. Computer programs have been written which
allow rapid inquiry, sorting and listing of UST records, facilitating
the issuance of testing and removal notifications in an efficient and
economical manner. These programs were written in a commonly-used
database system and operated from a Personal Computer.
Results and Discussion
To determine which of the towns' programs were the most effective
at reducing the overall risk to groundwater and which components of the
program lead most to its success, we partitioned the towns' actions into
four "levels": registration, tagging and testing; registration and
tagging only; registration only (no oil-dealer participation in the
notification process); and those taking no action. The evaluation
criteria used is the number of tanks taken out of service and is based
on the assumption that a tank removed from service translates to a
reduction in the overall threat to groundwater.
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Figure 1 indicates the number of tanks taken out of service in each
of five of the nine towns which have accepted the full regulation.
These five towns were selected for analysis based on the ability to
obtain reliable tank-removal information for both pre-regulation and
regulation periods. The regulations in each of these towns were passed
during 1987 and became effective in the latter part of that year.
Therefore, 1988 is considered the first regulatory year in these towns.
These data are compared with that of five towns (Figure 2) which have
promulgated regulations requiring only registration of tanks (Dennis,
Harwich and Sandwich) or towns having no regulation at all (Eastham and
Yarmouth). These data show that there were greater increases in tank
removal activity in towns having a complete regulation compared with
towns which do not. Towns with a comprehensive regulation generally had
a 4-60 fold increase in tank removals across pre-post regulatory years
(Figure 1) and greater than 5% of the UST population taken out of
service each year (Table 1) . This compares with towns which do not have
a comprehensive regulation and generally exhibit less than a 5-fold
increase in activity across years 1986-1989 (Figure 2) and have less
than 5 % of the UST population removed each year (Table 1).
14O -
13O -
12O -
6: 1OO -
90 -
80 -
TO -
OO -
50 -
4O -
30 -
SO -
W -
0 -
60
i
J=\\
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11
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47
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122
110
:v
22
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o\
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ORLEANS CmTWM BAKNSTABIE FALkd/TH
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27
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Figure 1 Numbers of residential UST taken o".t of service in
selected towns having comprehensive UST regulations. Barnstable
County, Massachusetts 1987-1989.
204
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100
13O -
140
130 -
120 -
110 -
100 -
90 -
60 -
70 -
60 -
SO -
•SO -
30 -
20 -
10 -
IX XI 1987
Figure 2' Numbers of residential UST taken out of service in
selected towns without comprehensive UST regulations. Barnstable
County, Massachusetts 1986-1989. ND= no data.
Table 1: Percentage of total residential underground tanks removed in
the years 1986-1989. Numbers in parentheses represent the estimated
number of USTs present in 1987.
Towns with comprehensive UST regulations
1987
1988
1989
Orleans
(440)
.2%
14%
18%
Chatham
(380)
3%
13%
7%
Barnstable
(900)
2%
13%
16%
Falmouth
(650)
.6%
3%
5%
Brewster
(300)
2%
9%
6%
Towns without comprehensive UST regulations
1986
1987
1988
1989
Dennis
(305)
1%
2%
6%
10%
Harwich
(226)
ND
ND
2%
10%
Sandwich
(350)
ND
ND
1%
2%
Eastham
(325)
.6%
3%
4%
.7%
Yarmouth
(600)
.5%
1%
2%
3%
Total number of tanks is estimated, numbers removed are from fire
department records. ND= No data.
Among towns having a comprehensive regulation, there are differences
in the success of the program as evidenced by the number of tanks taken
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out of service. Although it is difficult to totally isolate those
factors which account for the success of residential UST programs, our
experience in nine towns allows us to draw some conclusions.
The most successful programs exist in the towns of Orleans and
Barnstable. Several factors contribute to the success in Orleans.
Foremost, since they were the first town to adopt the regulation, they
received maximum input from our department. Also, both the health and
fire departments made strong commitments toward addressing the economic
and regulatory issues associated with tank removal. In early 1987,
while the costs of removing tanks were high due to the absence of Cape
companies in this industry, officials in Orleans, following careful
research of the regulations involved, established policies and
procedures which minimized the costs to the average tankowner. In
short, Orleans encouraged individuals to take advantage of a two-year
abandonment period (following removal of product from the tank), which
spreads the costs of tank removal and replacement over a broader period.
In addition, this town allows the disposal of tanks at the local
landfill (a practice not allowed in some other Cape towns), thus
reducing the overall costs of removal.
The success of the program in Barnstable can largely be attributed
to the commitment of the town in terms of personnel and effort. This
town's hazardous waste specialist was designated the responsibility for
overseeing the UST program and some of the five town fire departments
are quite committed to the program. In addition, the health department
aggressively solicited the participation of the oil dealers in the
notification process. In the Town of Chatham, where there was an
intermediate level of success between Orleans and Barnstable, the
alternate was true. In this town, the fire department took the more
aggressive role in the enforcement of the UST regulation. In addition
to the supportive agencies in each of these three most-successful towns,
another factor, that of the economic level of the community, may come
into play in determining the overall number of UST removals. It is
interesting to note that the Cape towns exhibiting the highest estimated
per capita income levels are Orleans and Chatham (U. S. Bureau of the
Census, 1985).
Among the Cape towns which opted to adopt only the registration
requirement of the UST regulation or which opted not to update their UST
regulation, there was, again, varying degrees of success in eliciting
removals. In the towns of Dennis and Harwich which have mandatory UST
registration (Dennis requiring oil-dealer participation in the
notification process), it is projected that nearly 10% of the UST will
be removed from service during 1989. When the Town of Harwich recently
adopted a comprehensive regulation, the fire department immediately
received numerous inquiries regarding tank removal. The experience in
Dennis and Harwich contrasts with that of Sandwich, Eastham and Yarmouth
which generally remove less than 5% of their tanks/year.
In summary, our experience indicates that a reduction in the threat
to groundwater is related to the level of regulation adopted. When there
was no residential UST regulation or public education program, we
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observed annual removal rates of 1% or less. The general public
education which occurs when there is an aggressive regional program
seemed to also benefit towns which did not adopt any regulation (1-4%
annual removal). Towns actively registering tanks, but having no further
regulation, had up to 10% of their UST removed annually. Adoption of
a comprehensive UST regulation resulted in an annual removal rate as
high as 18%. The most important factors in determining the success of
the UST program in Barnstable County were the support of a regional
agency, commitment of fire and health department personnel at the local
level and a public education effort. The acceptance of the
comprehensive regulation was significantly fostered by the development
and use of inexpensive testing and removal methods.
Commercial UST Program
Existing Massachusetts regulations (527 CMR 9.00 Tanks and
Containers) impose various restrictions on motor fuel UST. Part of
BCHED's program is to assist the local fire departments with the
enforcement of the sections which require these tanks to be registered
and to be tested at certain ages. Our experience in the last two years
has indicate'd that although compliance with the registration requirement
is quite good (99.5%), many tanks are not being tested as they should.
In the summer of 1989, visits were made to 15 of the 19 Cape fire
departments (at present, visits to remaining departments are being
arranged). Records on approximately 770 tanks were reviewed, updated,
and records of previous tightness tests were checked. Letters were then
sent to tank owner/operators whose fire department files did not show
appropriate tests. Of the 194 (25%) tanks in this category, 31 (16%)
responded with records showing either that the tanks had previously been
removed or that the required testing had been done. The reason for
inaccurate fire department records in these 31 cases could be because
the tank owner/operators were negligent in sending the information to
the fire departments, or because the fire departments lost/misplaced the
information. Of the remaining 163 tanks which still appear to have been
out of compliance at the beginning of the summer, owner/operators of 76
(47%) have responded to our letter with schedules for testing and/or
removal of the tanks. At the time of this writing, owner/operators of
87 tanks (53%) have yet to respond to our letter, however some
notifications have only recently been issued.
In summary, the passage of comprehensive state commercial UST
regulations does not mean, of itself, that the threat to groundwater has
been alleviated. Indeed, over 20% of the active commercial UST in our
area were out of compliance with state testing regulations prior to our
efforts. However, with a fairly-minimal effort such as sending a
reminder letter, a significant increase in compliance can be obtained.
References
Stiefel, C.L. and G.R. Heufelder. 1988. Journal of New England Water
Works Association, Volume 102(4): 254-266.
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Appendix
FUEL STORAGE SYSTEM REGULATIONS
Whereas, leaking fuel storage systems pose an immediate and serious
threat to Cape Cod's sole source aquifer, and,
Whereas, the Town of ( ) does not have records to locate all such
systems installed within the Town,
Therefore, under Chapter 111, Section 31, of the Massachusetts General
Laws, the( ) Board of Health hereby adopts the following regulation
to protect the ground and surface waters from contamination with liquid
toxic or hazardous materials.
DEFINITIONS: "Toxic or hazardous materials" shall be defined as
all liquid hydrocarbon products including, but not limited to, gasoline,
fuel and diesel oil, and any other toxic or corrosive chemicals,
radioactive materials or other substance controlled as being toxic or
hazardous by the Division of Hazardous Waste of the Commonwealth of
Massachusetts, under the provisions of Massachusetts General Laws,
Chapter 21C, Section 1, et. seq.
The following regulations apply to all toxic or hazardous material
storage systems:
Section 1. Installation of Fuel Storage Tanks
1-1. Following the effective date of this regulation, the installation
of all underground fuel, gasoline or other chemical storage tanks shall
conform with the following criteria: In that the United States
Environmental Protection Agency designated the Town of ( ) as
overlying a sole source aquifer, secondary containment of tank and
piping and an approved in-tank or interstitial space monitoring system
shall be required for new or replacement tanks.
1-2. Following the effective date of this regulation, all tanks
installed aboveground outside shall be of material approved for
outside use.
Section 2. Tank Registration
The following regulations shall apply to A) all underground tanks
containing toxic or hazardous materials as defined above which are not
currently regulated under 527 CMR 9.26 - Tanks and Containers, to B) all
tanks containing fuel oil, whose contents are used exclusively for
consumption on the premises, and to C) farm and residential tanks of
1,100 gallon capacity, or less, used for storing motor fuel for
non-commercial purposes.
2-1. Owners shall file with the Board of Health, on or before (
) the size, type, age and location of each tank,, and the type of
fuel or chemical stored in them. Evidence of date of purchase and
installation, including fire department permit, if any, shall be
included along with a sketch map showing the location of such tanks on
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the property. Upon registering the tank with the Board of Health, the
tank owner will receive a permanent metal or plastic tag, embossed with
a registration number unique to that tank. This registration tag must
be affixed to the fill pipe or in such a location as to be visible to
any distributor when filling the tank and to any inspector authorized
by the Town.
2-2. Effective ( ) every petroleum and other chemical
distributor, when filling an underground storage tank, shall note on the
invoice or bill for the product delivered, the registration number
appearing on the tag affixed to the tank which was filled. Every
petroleum and other chemical distributor shall notify the Board of
Health of the existence and location of any unregistered or untagged
tank which they are requested to fill. Such notification must be
completed within two (2) working days of the time the distributor
discovers that the tank registration tag is not present.
2-3. Prior to the sale of a property containing an underground storage
tank, the fire department must receive from the current owner a change
of ownership form for the registration of the underground storage tank.
Such form can be obtained from the fire department.
Section 3. Testing
3-1. The tank owner shall have each tank and its piping tested for
tightness fifteen and twenty years after installation and annually
thereafter. A tank shall be tested by any final or precision test, not
involving air pressure, that can accurately detect a leak of 0.05
gal/hr, after adjustment for relevant variables, such as temperature
change and tank end deflection, or by any other testing system approved
by the Board of Health, as providing equivalent safety and
effectiveness. Piping shall be tested hydrostatically to 150 percent
of the maximum anticipated pressure of the system. Certification of the
testing shall be submitted to the Board of Health by the owner, at the
owner's expense. Those tanks subject to the testing requirements of
this regulation shall submit the certification of testing to the Board
of Health by ( ) . Tanks which are currently tested under the
provisions of 527 CMR 9.13 are exempt from this section. For purposes
of this section, tanks of unknown age are assumed to be 20 years of age.
Section 4. Maintenance of Fuel Storage Systems
4-1. All underground fuel lines which do not have secondary containment
shall be replaced with an approved double-containment system at which
time any service to the system requiring a permit is performed.
4-2. All above-ground elements of a fuel storage system shall be
maintained free of leaks and visible rust.
4-3. All in-tank or interstitial-space monitoring systems shall be
checked on a monthly basis to verify system integrity. Records of these
checks shall be sent to the Board of Health on an annual basis.
Section 5. Report of Leaks or Spills
5-1. Any person who is aware of a spill, loss of product, or unaccounted
for increase in consumption which may indicate a leak shall report such
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spill, loss or increase immediately to the head of the fire department
and to the Board of Health.
Section 6. Tank Removal
6-1. All fuel, gasoline or other chemical tanks not regulated under 527
CMR 9.00 (farm or residential tanks of 1,100 gallons or less and
underground tanks storing fuel for consumptive use at the property) in
service on the effective date of this regulation, shall be removed
thirty (30) years after the date of installation. If the date of
installation is unknown, the tank shall be assumed to be twenty years
old. All underground storage tanks currently subject to the removal
regulation (30 years or older) must be removed by ( ) .
6-2. Prior to the removal of an underground storage tank governed by
this regulation, the owner shall first obtain a permit from the head of
the fire department, pursuant to M.G.L., C. 148.
6-3. Any person granted a permit by the Marshal or the head of a local
fire department to remove a tank under the provisions of M.G.L., C. 148
or 527 CMR 9.00, shall within 72 hours provide the permit granting
authority with a receipt for delivery of said tank to the site
designated on the permit.
6-4. Before any person is granted a permit by the Marshal or the head
of a local fire department to remove a tank under the provisions of
M.G.L., C. 148 or 527 CMR 9.00, and said tank is not being transported
to an approved tank yard, the person requesting the permit shall provide
the permit-granting authority with written approval from the
owner/manager of the disposal site. (Reference: 502 CMR 3.00 for tank
removal and disposal procedure).
Section 7. Costs
7-1. In every case, the owner shall assume responsibility for costs
incurred necessary to comply with this regulation.
Section 8. Variances
8-1. Variances from this regulation may be granted by the Board of
Health after a hearing at which the applicant establishes the following:
(1) the enforcement thereof would do manifest injustice; and (2)
installation or use of an underground storage tank will not adversely
affect public or private water resources. In granting a variance, the
Board will take into consideration the direction of the ground water
flow, soil conditions, depth to ground water, size, shape and slope of
the lot, and existing and known future water supplies.
Section 9. Severability
9-1. Provisions of this regulation are severable and if any provision
hereof shall be held invalid under any circumstances, such invalidity
shall not affect any other provisions or circumstances.
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BARNSTABLE COUNTY HEALTH AND ENVIRONMENTAL DEPARTMENT
SUPERIOR COURT HOUSE
BARNSTABLE, MASSACHUSETTS 02630
PHONE: 362-2511
EXT. 330
LAB 337
CLINIC 340
Biographical Sketch of Authors
Charlotte S'tiefel is an Environmental Program Specialist with the
Barnstable County Health and Environmental Department. '•She
received a degree in biology, with honors, from Gustavus Adolphus
College in St. Peter, Minn. She has held several positions
related to environmental regulation and has worked in local,
state and federal government offices. She is now in her third
term as an elected water commissioner in the North Sagamore Water
District.
George Heufelder is the Environmental Program Manager with the
Barnstable County Health and Environmental Department. Following
the receipt of his Masters Degree in Biology from Eastern
Michigan University, he was involved in a number of environmental
monitoring projects conducted by Great Lakes Research Division,
University of Michigan. In his capacity at BCHED he is
instumental in writing, obtaining and conducting grants to
address critical environmental issues.
211
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212
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JOINING FORCES:
PUBLIC AND PRIVATE MANAGEMENT OF GROUND WATER RESOURCES
John S. Malleck and Lisa K. Voyce
U.S. Environmental Protection Agency, Region II
ABSTRACT:
This paper describes a new program designed to protect public
water supplies from contamination, the Wellhead Protection
Program; and provides a framework for implementing the Program,
through a collaborative government and business matrix organiza-
tion.
Local involvement is the key to success of any plan to protect
ground water resources; and "local" includes the town council,
planning board, health department, water and sewer authorities,
land developers, and businesses that are responsible for protect
ing, or are using, underground sources of water. Federal and
State government also play a role in determining guidelines for
implementation, providing technical assistance, and developing
funding options for Wellhead Protection.
213
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John S. Maileek
John Malleck currently manages both the Office of Ground Water
Management and Underground Injection Control Section for EPA
Region II. He is responsible for the cross-program implementa-
tion of the Agency's Ground Water Protection Strategy, Sole
Source Aquifer Designation and- Demonstration Programs, the
Wellhead Protection Program, Agricultural Chemicals in Ground
Water Strategy, Superfund compliance with water programs, and
regulation of injection well activity for New York, New Jersey,
Puerto Rico and the Virgin Islands.
Mr. Malleck has worked for EPA for ten years. Prior to his
current assignment, he supervised the beginning stages of the
Underground Injection Control program, when no one really knew
how many wells were in the Region, or where they were. He has
also served as project officer for EPA water and air quality
grants, and was instrumental in developing the national Sole
Source Aquifer program.
He earned a M.S. in Water Resource Management from the University
of Michigan, and a B.S. in Environmental Science from Rutgers -
The State University of New Jersey.
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THE UIC CLASS IV-V WELL SURVEY IN MAINE:
INVENTORY, ASSESSMENT AND COMPLIANCE
Mary Rudd James and Anthony J. Pisanelli
Dept. of Environmental Protection Environmental Protection Agency
State House Station #17 Region I - JFK Federal Building
Augusta, Maine 04333 Boston, MA 02203-2111
Abstract
The Maine Department of Environmental Protection, Bureau of Water Quality
Control administers the Safe Drinking Water Act Underground Injection Control
(UIC) Program. -The focus of Maine's program is on Class IV and Class V
injection wells. In 1988 and 1989, a questionnaire requesting information on
discharges was sent to service stations. The survey responses, in association
with field inspections and categorization of floor drain discharges served as
the basis for the development of a UIC Class IV and Class V program.
This paper will describe the program and how it relates to other state ground
water protection efforts, specifically:
- - the relationship of the UIC program to the Maine Groundwater Management
Strategy and interagency coordination with the Wellhead Protection Program
-- the use of existing state computer database systems to provide information
on potential Class IV and Class V injection wells
-- the use of mail surveys to inventory the nature and extent of UIC
activities
-- how automation of the UIC database efficiently manages survey results in
order to expedite the mailing of regulations and best management practice
notices, and increases the efficiency of compliance and initiation of
enforcement activities
-- the development of a field inspection and enforcement/compliance strategy
with an interagency approach
215
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-- the development of a program for municipal officials to provide technical
assistance information on how communities can control Class IV and Class V
UIC wells
-- the future direction of Maine's UIC program
216
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Introduction
Underground Injection Wells are regulated by the federal Safe Drinking Water
Underground Injection Control Program. The U.S. Environmental Protection
Agency (EPA) promulgated regulations (40 CFR Parts 124, 144, 145 and 146) to
implement the Safe Drinking Water Act (SDWA). The EPA regulations and the
SDWA contain provisions to delegate UIC primary enforcement authority to
states having the necessary legal authority, technical expertise, and
administrative capability. The Maine Department of Environmental Protection
(DEP) demonstrated the necessary requirements and was awarded UIC primacy on
September 26, 1983. (Maine State Planning Office, 1989)
The DEP consists of six Bureaus: Water Quality Control; Air Quality Control;
Land Quality Control; Oil and Hazardous Materials Control; Solid Waste
Management; and Administration. The UIC program resides within the Bureau of
Water Quality Control, which consists of five Divisions: Policy, Information
and Grants; Licensing and Enforcement; Operation and Maintenance; Municipal
Services; and Environmental Evaluation and Lake Studies. The UIC program was
initially the responsibility of the Policy Section, but now is the
responsibility of the Division of Operation and Maintenance.
In Maine, the discharge of pollutants to ground water is a violation of both
state and federal laws. Appendix A contains excerpts from the applicable
state statutes: The Maine UIC program is established by Chapter 543 of the
rules of the Board of Environmental Protection (06-096 Code of Maine Rules
543, July 1983), which is contained in Appendix B. The rules mandate a
program and procedures for the permitting of proposed Class I, II, and III
wells using the authority established in the EPA regulations cited above. The
Board, under the state authority of 38 M.R.S.A. Sections 420(2) and (3).
prohibits the permitting of Class IV wells. Class V wells may also be
maintained, provided a waste discharge license is obtained from the Board and
all other applicable necessary approvals are obtained. A waste discharge
license is not required for subsurface waste water disposal systems designed
and installed in conformance with the Maine Subsurface Wastewater Disposal
Rules (10-144 Code of Maine Rules 241, July 1980) and used only for the
discharge of sanitary waste water.
The UIC Program, a Component of Maine's Groundwater Srategy
The Maine Groundwater Management Strategy (GWMS) was developed to accomplish
the State's ground water management goals and to implement its ground water
policies. The GWMS identifies in detail the necessary elements for sound
ground water management. Contained within the element "Controlling Sources of
Contamination," is a description of the DEP UIC program and the direction it
will take over the next two years. The UIC program plays a central role in
addressing this strategy element in a comprehensive manner. This element, in
combination with the others (Program Coordination; Research; Classification;
Data Management; Compliance and Enforcement; Technical Assistance; Education;
and Public Involvement) describes the necessary components for sound ground
water management. These elements are interdependent and the necessary parts
of a complete state strategy. Each of these elements depend on the
217
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implementation of the others and is important to ensure the continued
availability of high quality ground water for the growing needs of Maine.
(Maine State Planning Office, 1989)
Due to Maine's hydrogeologic setting, the pressurized disposal of large
quantities of waste materials below the land surface is impractical and
ususally not cost effective. Areas of the state with rocky outcrops tend to
be fractured near the land surface. In the majority of these settings, the
openings are saturated with ground water. The pressurized emplacement of
liquid waste materials into the subsurface through these fractured openings is
difficult for most injection well pumps to accomplish.
Other areas of the state contain sand and gravel aquifers that typically
overlay marine clays or areas of fractured bedrock. In these locations, the
pressurized injection of liquid waste is more feasible than in fractured
bedrock settings, yet costs are still high relative to other disposal
practices. In addition, Maine's sand and gravel aquifers are typically used
as both public and private water supplies. More than sixty percent of Maine
households obtain their drinking water from ground water through public and
private wells and springs. (Maine Department of Environmental Protection,
1986)
For the above reasons, the majority of facilities considered UIC wells for the
disposal of waste are gravity feed/low technology systems. They are usually a
dry well or septic tank/leach field system. The term "well" is applied
loosely and in Maine relates to a specialized form of subsurface disposal.
(Maine Department of Environmental Protection, 1986)
In 1981, an inventory of injection wells in Maine found no Class I, II, III,
or IV wells, but fourteen Class V wells were located. In 1986, a reassessment
found that none of the Class V wells were still in operation, although
monitoring was still required at some of the sites. In 1987, additional Class
V wells were reported and actions were taken to eliminate the discharge of
pollutants at these sites.
In 1987, a report to Congress was submitted by EPA summarizing the results of
State surveys concerning Class V injection wells as defined by the 1986
Amendments to the SDWA. Thirty Class V well types were identified nationally
in the survey. Class V wells determined to have a high ground water
contamination potential included septic systems, waste disposal wells, and
automobile service station waste disposal wells. (U.S. Environmental
Protection Agency, 1987) Based on these results, the DEP embarked on a
comprehensive evaluation of threats to ground water quality from service
station floor drains. The DEP's program activities to investigate these
threats included inventory, inspection, enforcement/compliance, technical
assistance, and public education activities geared toward Class IV and Class V
UIC wells. The components of the UIC program are described in the following
sections. Relationships between the UIC program and other state agency ground
water protection efforts and strategy elements will also be discussed. (U.S.
Environmental Protection Agency. 1987)
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Administration
During 1988 and 1989, the goals of the DEP UIC work plan included: 1)
evaluating the nature and extent of selected UIC Class IV and Class V
injection activities in Maine; 2) eliminating Class IV and Class V injection
wells through voluntary compliance and/or formal enforcement actions; and 3)
providing an information program to the general public to assist residents in
better understanding the issues related to the protection of Maine groundwater
resources.
The goals of the UIC program were accomplished through the following
activities:
1. Existing state computer database systems were used to obtain mailing
information on potential Class IV and Class V injection wells, and mail
surveys were used to evaluate the nature and extent of UIC activities.
Surveys were mailed to automobile service stations, businesses likely to have
Class IV or Class V injection wells;
2. Field inspections of selected businesses with suspected Class IV or Class
V injection wells were performed;
3. Facilities operating Class IV or Class V injection wells were notified of
applicable Maine statutes and requested to comply voluntarily;
4. Formal enforcement action was initiated against selected facilities
operating Class IV or Class V injection wells; and
5. Fact Sheets were provided to the potential violators and the general
public explaining the UIC program and the need to protect the groundwater.
The fact sheets also suggested best management practices for materials
commonly found at the targeted facilities.
Use of Existing State Computer Database Systems
Numerous businesses regulated by a variety of state and federal agencies may
have underground injection wells. One area of concern targeted by the UIC
program was floor drains at automobile service stations. The potential for
locating injection wells at these facilities is very high due to the nature of
the materials used during the course of business. Most automobile service
stations have underground oil and gasoline storage tanks, which are regulated
by the DEP, Bureau of Oil and Hazardous Materials Control. Information was
already on file which would assist in the inventory of injection wells.
Tapping into existing computer databases expedited the process of
investigating potential Class IV and Class V injection wells.
The Bureau of Oil and Hazardous Materials Control licenses or registers
facilities dealing with the wholesale oil distribution, retail oil
distribution, oil storage at commercial and industrial establishments, oil
storage at residential, public, agricultural, and federal facilities, chemical
storage, and hydraulic lifts. The UIC program initially targeted retail
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distributors of gasoline. Information on contact official, address,
telephone, and potential impact on groundwater for these facilities is
maintained by the Bureau on the State's mainframe computer. The information
necessary to conduct a UIC survey was downloaded to a microcomputer, and
manipulated using dBase III Plus. The database of retail distributors of
gasoline was further broken down by extracting only motor vehicle inspection
stations. This resulted in a manageable number of facilities which were
surveyed in 1988. Surveys were sent to 1,156 facilities. In 1989. surveys
were sent to the remaining 1,949 facilities on the retail gasoline
distribution list.
Another type of business of concern to the Department was food processors.
Very few of these businesses are licensed under the State's waste discharge
laws, making the possibility of illegal discharges to the surface or
groundwater very high. The State Department of Agriculture, Food and Rural
Resources provided mailing information on licensed food processors. Since the
mailing information is maintained on a microcomputer, the database was easily
converted for use on the DEP microcomputer.
The Use of Mail Surveys
Surveys were mailed to over 3,000 automobile service stations in 1988 and
1989. Facility, owner, and operator information obtained from the Bureau of
Oil and Hazardous Materials Control assisted in personalizing the surveys.
The survey requested information on predominant soil type, number and location
of floor drains, the discharge location of the floor drains, distance to the
nearest water supply, and the type of water supply (public or private). A
self-addressed stamped envelope was provided with each survey, resulting in a
nearly 100% return rate. A copy of the survey is attached as Appendix C.
Surveys were also sent to 175 food processors in 1989. The information
requested was similar to the automobile service station survey, and also asked
for additional information, such as the volume of process or cooling water
used, treatment of the water, discharge location, whether or not cleaning
compounds were used, and if chlorine was added to the water discharged.
Again, the surveys were "personalized" using information obtained from the
State Department of Agriculture.
The information obtained through the survey of automobile service stations and
food processors has assisted the DEP in targeting facilities with potential
Class IV and Class V injection wells for corrective and/or enforcement action.
Automation Efficiently Manages Survey Results
As the surveys were returned, the responses and corrected facility information
were entered into the computer database. The 1988 automobile service station
survey information has been collected and evaluated. Of the 1,156 surveys
sent in 1988, the following breakdown of facilities were targeted for further
attention:
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356 facilities with floor drains discharging directly to the soil
119 facilities with floor drains discharging to septic systems
222 facilities with floor drains discharging to publicly owned treatment
works
75 facilities with floor drains discharging to surface water
Facilities with discharges to surface water were referred to the Water Bureau
Division of Licensing and Enforcement for investigation as illegal overboard
discharges.
As a courtesy, Publicly Owned Treatment Works (POTWs) were notified of
facilities discharging to their treatment plant, with the request that the DEP
be notified if they took any action against the facilities. Of the 100 POTWs
involved, about 25 wrote the DEP about inspections they made of the targeted
facilities, or provided information on local regulation of floor drain
discharges. Many municipal officials called the DEP to discuss the UIC
program and its impact on the town. Overall, the response from local
officials was very good.
Facilities with discharges to the soil or septic systems were targeted for
investigation as part of the UIC program. These facilities, in addition to
those with discharges to a POTW, were sent a letter providing information on
applicable regulations and best management practices (BMPs) for materials
commonly found at automobile service stations. (The "Fact Sheets" containing
this information are attached as Appendix D.) The letters were generated
automatically based on the type of survey response coded into the computer.
The facilities were asked to respond in writing within 20 days and provide
information on their disposal practices of materials such as waste oil, spent
solvents, parts cleaners, and degreasers. Of the 475 facilities required to
respond to the notice of regulation letter (those facilities with discharges
to the soil or septic systems), the breakdown of responses is as follows:
69 facilities eliminated or never had a floor drain
214 facilities discharged only water through the floor drain
8 facilities connected the floor drain to a municipal sewer system
5 facilities connected the floor drain to a holding tank
18 facilities are no longer service stations
1 facility actually discharges to the surface water, not the soil
156 facilities did not respond
4 facilities were duplicates
Those facilities with continuing discharges, and those facilities not
responding to the notice of regulation letter will be further investigated as
part of the UIC program.
The 1989 automobile service station survey information has also been collected
and evaluated. Of the 1,949 surveys sent, the following breakdown of
facilities were targeted for further attention:
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63 facilities with floor drains discharging directly to the soil
47 facilities with floor drains discharging to septic systems
216 facilities with floor drains discharging to POTWs
17 facilities with floor drains discharging to surface water
The notification and enforcement procedure used for the 1988 survey results,
described above, was also used for the 1989 survey results. The responses to
the notice of regulation letter for 1989 survey responses are still being
received, and therefore have not yet been compiled.
The results of the food processing survey have not yet been tabulated.
Enforcement/Compliance Strategy
The DEP initially intended to tie its UIC enforcement program to the State's
Wellhead Protection Program. Injection wells located within wellhead
protection zones would receive top priority for enforcement. However, due to
legislative delays in the implementation of Maine's wellhead program, a
different method for prioritizing enforcement actions was established. The
Maine Department of Human Services, Division of Health Engineering regulates
drinking water supplies in the state, and will administer the Wellhead
Protection Program. Staff of this agency assisted the DEP in reviewing public
water supplies in the State to determine the source and volume provided.
Public water utilities with ground water supplies serving more than 400 people
were given the highest priority for enforcement.
The 156 faci-lities not responding to the notice of regulation letter (1988
survey) were prioritized first. A list of the 20 most critical facilities was
referred to the Division of Licensing and Enforcement for further action. The
Division sent certified letters to the 20 facilities, requiring them to
respond within 20 days to avoid issuance of a consent agreement with monetary
penalty. Most of the facilities responded within the time allowed, and
voluntarily eliminated their floor drain.
Field Inspections
During 1988, assistance with field inspections of UIC facilities was provided
by the Division's field personnel during the course of their regular duties
inspecting treatment plants and investigating complaints. About 184
inspections were made. Field personnel also assisted in collecting Federal
Underground Injection Reporting System (FURS) data elements not collected
originally in the 1988 survey.
A Conservation Aide was hired for the summer of 1989 to perform field
inspections of facilities with potential Class IV and Class V injection wells.
Over 100 facilities were inspected throughout the state. The facilities
targeted were in two categories: 1) those who stated in the 1988 survey they
had a floor drain discharge, then stated in their response to the notice of
regulation letter they had eliminated it; and 2) those facilities targeted for
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enforcement due to a lack of response to the notice of regulation letter. The
results of the 102 facilities inspected in 1989 is as follows:
55 facilities eliminated the floordrain
16 facilities discharged only water through the floor drain
2 facilities connected the floor drain to a municipal sewer system
1 facility connected the floor drain to a holding tank
5 facilities are no longer service stations
13 businesses closed
10 facilities did not plug the floor drain (after stating they would)
Technical Assistance for Municipal Officials
During the summer of 1988, the Maine Department of Human Services, Division of
Health Engineering conducted a pollution source inventory project. Funding
for this effort came from the UIC program. The inventory focused on Class IV
and Class V wells considered to have the potential to contaminate the Portland
Water District ground water supply wells (a Wellhead Protection Area) serving
the town of North Windham, Maine.
This project provided insight to the sources of information available and
steps involved in conducting an inventory. The project was successful, due
largely to the orderly and accurate nature of town records of land use
activities. Based upon the project findings, the water district made
recommendations to the Town of North Windham for incorporation into a land use
ordinance. The intent of the proposed ordinance is to reduce the risk of
contamination of the Town's public water supply. The results of this project
have contributed to the development of a technical assistance program for
municipal officials. (Maine Department of Human Services, 1988)
The DEP is compiling a written handbook detailing threats to groundwater, how
those threats may be mitigated through implementation of BMPs, applicable
statutes, and how other municipalities have managed and controlled threats to
their groundwater. The handbook is intended as a reference book, advising a
municipal official of the responsible agency for groundwater problems. The
Department proposes to identify known threats to the groundwater in each Maine
municipality. This will be done using existing computer databases containing
information on businesses whose activities are likely to affect groundwater.
The Department also proposes to present a series of public information
meetings with municipal officials to present the handbooks, review actions
municipalities may take to control groundwater contamination, and receive the
municipalities input on how the DEP may better serve their needs to protect
Maine's groundwater.
Future Direction of Maine's UIC Program
The DEP plans to continue working with automobile service stations to follow
through on the information collected as a result of the 1988 and 1989 surveys.
All facilities not responding to the NOR letter will be recontacted or
referred for enforcement depending on the facility's proximity to underground
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drinking water supplies. In addition to investigating those facilities not
responding to the NOR letter, all facilities with discharges located near
underground sources of drinking water will be investigated further, even if
they responded to the NOR letter. Facilities not eliminating their floor
drain after stating they would do so will be recontacted and added to the
enforcement list if necessary. Any facility with the potential to endanger
underground sources of drinking water will be required to eliminate its
discharge.
As the UIC program continues, the DEP plans to investigate other businesses
with a high potential for groundwater contamination due to the nature of the
product involved or materials used. Some of the businesses the DEP will
review are: funeral homes; dry cleaners; automobile body shops and
rustproofers; and boatyards.
It is possible floor drain discharges will not be allowed from these types of
facilities in the future, but to implement this policy may require amendment
of the existing regulations. Under the present regulations, a business could
obtain a waste discharge license for a floor drain discharge if all
requirements were met. The DEP feels there is too great a risk involved to
allow floor drain discharges from businesses dealing with materials that could
contaminate ground water supplies if handled incorrectly or in case of an
accident. Since floor drain discharges have continued since the State's UIC
regulations were adopted in 1983, the requirement to eliminate the discharges
after this length of time may not be well received by the businesses affected.
At the very least, the DEP must begin an extensive public education process to
smooth the way for such a major initiative.
References
Maine Department of Environmental Protection, Maine's Underground Injection
Control Program, Revised Interim Report, December 1986.
Maine Department of Human Services, Pollution Source Inventory Pilot Project
(North Windham, Maine), 1988.
Maine State Planning Office, Maine Groundwater Management Strategy, June 1989.
U.S. Environmental Protection Agency. Report to Congress, Class V Injection
Wells, September 1987.
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Biographical Sketches
Mary Rudd James, Maine Department of Environmental Protection, State House
Station #17, Augusta, Maine 04333
Employed by the Maine Department of Environmental Protection since March 1986,
Mary James has been involved in the licensing of surface water discharges and
land use activities, and developed state regulations for the siting of a low-
level radioactive waste disposal facility. She became the UIC Coordinator for
Maine in January 1989. Prior to joining the DEP, she worked for the Maine
Attorney General's Office, the U.S. Attorney's Office, and the National Park
Service. She attended Michigan Technological University, and received a B.S.
in Natural Resources from Michigan State University.
Anthony J. Pisanelli, U.S. Environmental Protection Agency-Region I, JFK
Federal Building, Boston, MA 02203-2111
Since 1987, Anthony J. Pisanelli, Hydrologist, has served as the Maine State
Ground Water Program Manager in the Ground Water Management and Water Supply
Branch of the U.S. Environmental Protection Agency in Region I, Boston,
Massachusetts. Prior to joining EPA he was employed by the New England
Interstate Water Pollution Control Commission as their Ground Water
Coordinator.
Mr. Pisanelli holds a B.A. from Clark University in Biology and Environmental
Affairs and a M.S. from the University of Vermont in Water Resources. In
addition he has completed graduate coursework in geology, hydrogeology and
geochemistry of ground water. Presently he is an associate member of the
American Institute of Hydrology and a member of the National Water Well
Association and American Water Resources Association.
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APPENDIX A
Excerpts from Title 38, Maine Revised Statutes Annotated,
Regulating the Discharge of Pollutants to Groundwater
Section 361-A. Definitions
* * *
1. Discharge. "Discharge" means any spilling, leaking, pumping,
pouring, emptying, dumping, disposing or other addition of any
pollutant to water of the State.
* * *
4-A. Pollutant. "Pollutant" means dredged spoil, solid waste, junk,
incinerator residue, sewage, refuse, effluent, garbage, sewage
sludge, munitions, chemicals, biological or radiological materials,
oil, petroleum products or by-products, heat, wrecked or discarded
equipment, rock, sand, dirt and industrial, municipal, domestic,
commercial or agricultural wastes of any kind.
* * * *
Section 413. Waste discharge licenses
1. License required. No person shall directly or indirectly
discharge or cause to be discharged any pollutant without first
obtaining a license therefor from the board.
* * *
1-B. License required for subsurface waste water disposal systems.
No person shall install, operate or maintain a subsurface waste water
disposal system without first obtaining a license therefor from the
board, except that a license shall not be required for systems
designed and installed in conformance with the State of Maine
Plumbing Code, as promulgated under Title 22, section 42.
* * * *
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Section 420. Certain deposits and discharges prohibited
No person, firm, corporation or other legal entity shall place,
deposit, discharge or spill, directly or indirectly, into the inland
ground or surface waters or tidal waters of this State, or on the ice
thereof, or on the banks thereof so that the same may flow or be
washed into such waters, or in such manner that the drainage
therefrom may flow into such waters, any of the following substances:
1. Mercury.
* * *
2. Toxic or hazardous substances.
* * *
3. Radiological, chemical or biological warfare agents.
* * * *
Section 543. Pollution and corruption of waters and lands of the State
prohibited
The discharge of oil into or upon any coastal waters, estuaries,
tidal flats, beaches and lands adjoining the seacoast of the State,
or into or upon any lake, pond, river, stream, sewer, surface water
drainage, ground water or other waters of the State or any public or
private water supply or onto lands adjacent to, on, or over such
waters of the State is prohibited.
* * * *
Section 1317-A. Discharge prohibited
The discharge of hazardous matter into or upon any waters of the
State, or into or upon any land within the state's territorial
boundaries or into the ambient air is prohibited unless licensed or
authorized under state or federal law.
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Appendix B
06-096 DEPARTMENT OF ENVIRONMENTAL PROTECTION
Chapter 543 RULES TO CONTROL THE SUBSURFACE DISCHARGE OF POLLUTANTS
BY WELL INJECTION.
SUMMARY: These rules specify the State's program to control the subsurface
discharge of pollutants by well injection, in order to protect underground
sources of drinking water. Well injections are classified by type, and
different types are regulated differently. Class I wells (deep well
injection), Class II wells (injection of fluids associated with oil and gas
production), and Class III wells (injection of fluids associated with solution
mining of minerals) are regulated just as they would be if no State program
were adopted, since the applicable federal regulations are incorporated in this
chapter by references. New Class IV wells (injection of hazardous waste or
radioactive waste into or above water-bearing formation) are prohibited and
those in existence are required to be closed. All other types of discharge by
well injection are subject to licensing under 38 M.R.S.A., §413(1-B).
1. Definitions
As used in these rules, the following terms have the following meanings.
Other terms used in these rules have the meanings set forth at 38 M.R.S.A.,
§361-A.
A. Aquifer means a geologic formation, group of formations, or part of a
formation composed of rock or sand and gravel that stores and transmits
significant quantities of recoverable water, as identified (or subsequently
confirmed) by the Maine Geological Survey.
B. Board means the Maine Board of Environmental Protection.
C. Fluid means any material or substance which is capable of movement,
whether in a semisolid, liquid, sludge, gas or other physical state.
D. Formation means a body of rock or sand and gravel characterized by a
degree of lithologic homogeneity that is mappable on the earth's surface or
traceable in the subsurface.
E. Total Dissolved Solids means total dissolved (filterable) solids as
determined by standard test method 92 in "Standard Methods for the Examination
of Water and Wastewater," 14th edition, 1976, which is "Glass Fiber Filtration
at 180 °C."
F. Underground Source of Drinking Water (USDW) means any aquifer, except
those aquifers exempted in accordance with section 5 of these regulations.
G. Well means a bored, drilled or driven shaft or a dug hole, which has a
depth greater than its largest surface dimension.
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2. Classification of Wells
A. Class I. Wells used to discharge hazardous waste or any fluids
beneath the lowermost formation containing an underground source of drinking
water, except those wells that fall within the definition of a Class II or III
well.
B. Class II. Wells used to discharge fluids:
1. Which are brought to the surface in connection with conventional
oil or natural gas production and may be commingled with wastewaters from
gas plants which are an integral part of production operations, unless
those fluids are classified as hazardous waste at the time of their
discharge; or
2. for enhanced recovery of oil or natural gas; or
3. for storage of hydrocarbons which are liquid at standard
temperature and pressure.
C. Class III. Wells used to discharge fluids for extraction of minerals,
including:
1. Mining of sulfur by the Frasch process;
2. in situ production of uranium or other metals. This category (C)
(2) includes only in situ production from ore bodies which have not been
conventionally mined. Solution mining of conventional mines, such as
stopes leaching, is included in Class V.
3. solution mining of salts or potash.
D. Class IV. Wells used to discharge hazardous waste or radioactive
waste into or above an aquifer, whether or not the aquifer is an underground
source of drinking water.
E. Class V. Wells not included in Classes I, II, III, or IV.
3. Prohibited Discharges.
A. General. All subsurface discharges of fluids into or through a well
are prohibited except as authorized in accordance with these rules.
B. Hazardous Wastes. The subsurface discharge of hazardous waste into or
through a Class IV well is expressly prohibited. For the purposes of these
rules, "hazardous wastes" are those substances identified as hazardous by the
Board in Regulations, chapter 850, section 3(C). This prohibition is
established pursuant to the authority conferred upon the Board by Title 38,
M.R.S.A., §420(2), and is subject to the following limited exception.
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A Class IV well being used to discharge hazardous waste on the date these
rules are officially proposed may continue to be used for such a discharge for
a period of no more than six months after the effective date of these rules,
provided that during that time there is no increase in the amount, or change in
the type, of hazardous waste discharged, compared to that previously
discharged.
C. Radioactive Waste. The subsurface discharge of radioactive waste into
or through a Class IV well is expressly prohibited. Any discharge of
radiological warfare agents or high level radioactive waste to the waters of
the State, directly or indirectly, is expressly prohibited by Title 38
M.R.S.A., §420(3). Any other waste that contains radioactivity, regardless of
amount or concentration, is declared to be a toxic or hazardous substance
pursuant to Title 38 M.R.S.A., §420(2), based upon the criteria stated therein,
and its discharge to the groundwater is prohibited.
D. Preservation of Drinking Water Quality. Any subsurface discharge into
or through a Class V well that would cause or allow the movement of fluid into
an underground source of drinking water that may result in a violation of any
Maine Primary Drinking Water Standard, or which may otherwise adversely affect
human health, is prohibited.
NOTE! Maine Primary Drinking Standards are set forth in Rules of the
Department of Human Services, 10-144A CMR c. 231.
4. Permitted Discharges.
A. Class I, II and III wells. Discharges of fluids into or through Class
I, II, or III wells may be maintained, provided that those requirements
applicable to State programs in the regulations adopted by the United States
Environmental Protection Agency pursuant to the Federal Safe Drinking Water Act
on or before April 1, 1983, are satisfied. These regulations are found in
Title 40 of the Code of Federal Regulations, Parts 144, 145, 124 (insofar as
they are made applicable to State programs by 40 CFR §145.11) and 146. For
purposes of this subsection 4(A), the terms "Director" and "State Director"
shall mean the Maine Board of Environmental Protection or its delegated
representative.
NOTE: The subsurface discharge of hazardous waste is also regulated by
Rules of the Board of Environmental Protection, chapter 854, section 5(E).
B. Class V Wells. Discharges of fluids into or through Class V wells may
be maintained, provided that (1) a waste discharge license therefore is issued
by the Board prior to commencement of the discharge (or it is determined by the
Board that the proposed discharge is beyond the Board's waste discharge
licensing jurisdiction), and (2) any other applicable statutes and regulations
administered by the Board are satisfied, including the requirements of section
3(D) of these regulations.
NOTE: Since Class V wells are a catch-all category, it is difficult to
specify what other laws might apply, but for example, the Maine Hazardous
Waste, Septage and Solid Waste Management Act, 38 M.R.S.A. §§1301, et seq., or
the Site Location of Development Act, 38 M.R.S.A., §481 et, seq., might apply.
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5. Exemption of Certain Receiving Waters
After notice and opportunity for a public hearing, and subject to the
approval of the U.S. Environmental Protection Agency, an aquifer or a portion
thereof may be exempted from being an underground source of drinking water when
the Board identifies the location of the aquifer or portion in clear and
definite terms, and finds that it meets each of the following three criteria:
A. The groundwater contained in the aquifer or its portion has been
classified GW-B by the Maine legislature in accordance with Title 38 M.R.S.A.,
§371-B;
B. It is not being used as a public source of drinking water; and
C. It will not in the future serve as a public source of drinking water
because:
1. It is so contaminated or so situated that it would be
economically or technically impractical to recover the water or render it
fit for human consumption; or
2. It is mineral, hydrocarbon or geothermal energy producing, or has
been demonstrated by a license applicant as part of a license application
for a Class II or III well operation to contain minerals or hydrocarbons
that are expected to be commercially producible, considering their quantity
and location.
BASIS STATEMENT: The provisions of this chapter are required in order to
satisfy the State Program requirements of the Underground Injection Control
Program of the Federal Safe Drinking Water Act, 42 U.S.C. §300f ej: seq. The
Board is aware of no existing Class I, II or III wells in Maine and expects
there never will be any. For that reason only, the federal regulations are
incorporated verbatim by reference, as the simplest way to satisfy program
"delegation" requirements. The remaining provisions of this chapter are
somewhat more stringent than federal requirements because of the pervasiveness
of groundwater in Maine, its interconnectedness, and its present and future
wide-ranging use as drinking water.
After public hearing on September 22, 1982, this rule is adopted this 22nd
day of June, 1983.
AUTHORITY: 38 M.R.S.A. §343
38 M.R.S.A. §413
38 M.R.S.A. §420
EFFECTIVE DATE: July 4, 1983
Accepted for filing: June 29, 1983
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Appendix C
State of Maine
DEPARTMENT OF ENVIRONMENTAL PROTECTION
Bureau of Water Quality Control
State House Station #17, Augusta, ME 04333
FLOOR DRAIN SURVEY
NAME OF BUSINESS: ELM STREET MARKET
FACILITY INFORMATION
Facility ID#: MES200000001
Street Address: ROUTE 16 ELH STREET
Town or City: Anson Zip Code: 04958
County: Is the facility on land owned by an Indian Tribe?
Facility Phone: 2075352503 Facility Contact Person:
OWNER INFORMATION
Type of ownership: (private, public, state, federal or other)
If OTHER, please explain:
Owner: Organization (if any) : JOHNSON PRODUCTS, INC.
Street Address: P.O. BOX 300. 2 UEST MAIN ST.
Town or City: NEWTON JUNCTION State: m Zip Code: 03859
Owner Phone: 0033327900
OPERATOR INFORMATION
Operator:
Name of Operator's Business: HIUKLET. HARK it GIENNA
Street Address: ROUTE 16 ELH STREET
Town or City: NORTH ANSQN State: ME Zip Code: 04958
Operator's Phone: 2076352503
*** *** *** *** *** *** *** *** *** *** *** *** ***
PREDOMINANT SOIL TYPE. The facility is located on (check one):
Sand and gravel soils
Clay soils
Shallow to bedrock soils
Do not know
Other (Please explain below)
FLOOR DRAIN(S). Does the facility have floor drains? (Y/N) N
DISCHARGE LOCATION. If YES, indicate the number and discharge location
of the floor drain(s).
Municipal sewer system
Holding tank
Septic system
Pipe to stream or river
Directly into the ground
Other (Please explain below)
DISTANCE TO NEAREST WATER SUPPLY: feet
WATER SUPPLY. Is the water supply public or private? pub. pri.
A self-addressed stamped envelope is enclosed for your return of the
completed survey.
For additional information, please contact Mary James of the DEP at
(207) 289-7i96. Thank you for your assistance and cooperation.
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Appendix D
DEPARTMENT OF
ENVIRONMENTAL PROTECTION
Bureau of Water Quality Control
March 1989
Underground Injection Control Program
Fact Sheet #1
WHAT IS THE UNDERGROUND INJECTION
OONTROLPROGRAM?
The Underground Injection Control (UIC) Program
was established by the federal Safe Drinking Water
Act. The UIC Program regulates the subsurface
discharge of pollutants in order to protect
underground sources of drinking water. In Maine,
the Department of Environmental Protection (DEP)
administers the UIC Program, with support from the
U.S. Environmental Protection Agency (EPA). The
Maine UIC Program has been in effect since 1983,
when the Board of Environmental Protection
adopted regulations to control the subsurface
discharge of pollutants by well injection.
The UIC regulations identify five types of injection
wells. The term "well" is applied loosely and is
basically a specialized form of subsurface
wastewater disposal. Cesspools, septic systems,
wells, pits, ponds, and lagoons are considered
injection wells, and are subject to the UIC
regulations if used for the discharge of pollutants.
increasing the need for potable groundwater. The
continued high quality of this resource is of great
concern. In 1985, the Maine Ground Water Policy
was set forth in an Executive Order. The primary
goal of the Policy is to protect, conserve, and manage
Maine's groundwater resources to protect the public
health, safety, and general welfare; to meet future
water supply needs; and to sustain economic growth.
As the towns of Gray, Friendship, Saco, Winthrop
and Houlton have learned, a single pollution incident
can significantly effect the health and financial
welfare of an area's residents. The regulation of the
subsurface disposal of pollutants is crucial to
protecting underground sources of drinking water.
Contamination effects from UIC sites can range
from minima] decline in water quality to the presence
of toxic levels of heavy metals, organic and
inorganic contaminants, and radioactive materials.
The UIC program attempts to prevent potentially
harmful discharges from occurring, recognizing that
prevention of groundwater contamination is better
than cleanup in terms of health, engineering and cost.
WHY IS THE UIC PROGRAM IMPORTANT?
More than 60% of Maine households draw their
drinking water from groundwater through private
wells, public wells, and springs. Although most of
Maine's groundwater is still of high quality, the
growth and dispersion of Maine's population and
associated land use activities are threatening the
quality of Maine's groundwater resources and
WHO IS REGULATED UNDER THE MAINE
UICPROGRAM?
Anyone disposing of waste or wastewater through an
injection well, including a cesspool, septic system,
well, pit, pond, or lagoon is required under 38
M.R.S.A. Section 413(1-B) to obtain a waste
discharge license from the DEP. A license is not
required for systems designed and installed in
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conformance with the Maine Plumbing Code and
used solely for the discharge of sanitary wastewater.
The UIC regulations include five classes of injection
wells. The first four classes are defined as:
Class I: a well used to inject hazardous wastes
beneath an aquifer.
Class II: a well used to inject fluids associated
with oil and natural gas production.
Class III: a wefl used to inject fluids associated
with mineral extraction.
Class IV: a well used to inject hazardous waste
or radioactive waste into or above an
aquifer.
The DEP is not aware of any Class I, II, or III wells,
but they may be licensed under the regulations if all
requirements are met. Class IV wells are
prohibited in Maine.
A Class V well is any well that does not fall under the
definition of Classes I-IV and typically injects non-
hazardous fluids into or above an aquifer. Class V
wells may also be licensed under the UIC
regulations.
Facilities which discharge wastes to municipal
sewers or directly to surface waters are not regulated
under the UIC program, but are regulated by local
ordinance and other laws administered by the DEP.
WHAT TYPES OF WASTES ARE A THREAT
TO GROUNDWATER?
Industrial and commercial wastes discharged
through subsurface disposal systems can include
petroleum products, cleaning solvents and
degreasers, industrial and agricultural chemicals,
storrn water runoff, and a host of other chemicals.
Because the constituents of these products are often
persistent in groundwater, the cumulative impact of
continual disposal of these wastes from one or
several sources has the potential to cause widespread
contamination of the groundwater resources.
The potential for contamination to groundwater can
vary considerably based on several factors: design,
construction, and operation of the disposal system;
quality and volume of the material discharged;
where disposal occurs in relation to the drinking
water source; and localized hydrogeologic
conditions.
HOW DO YOU OBTAIN APPROVAL FOR A
CLASS V INJECTION WELL?
Facilities utilizing Class V injection wells must
obtain a waste discharge license from the DEP.
Again, a license is not required for systems designed
and installed in conformance with the State of Maine
Plumbing Code and used solely for the discharge of
sanitary wastewater.
The first step in obtaining a waste discharge license
is to submit an application to the DEP. The
application will be reviewed by the DEP and other
state agencies before a decision is made to approve
or deny the discharge. Any discharge must meet the
requirements set forth in the laws and regulations
administered by the Department in order to be
approved.
For more information, please contact:
Department of Environmental Protection
Bureau of Water Quality Control
State House Station #17
Augusta, Maine 04333
(207) 289-3901
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DEPARTMENT OF
ENVIRONMENTAL PROTECTION
Bureau of Water Quality Control
May 1989
Underground Injection Control Program
Fact Sheet #2
AUTOMOBILE SERVICE STATIONS AND
RF.T ATED BUSINESSES
THE PROBLEM. What should be done with waste
ofl, hazardous waste, and contaminated wastewater?
At an automobile service station, these materials
include solvents, cleaners, used oil and fluids,
detergents, heavy metals, gasoline, and kerosene. In
the past, our solution was to pour everything down
the drain, outside on the ground, or in the nearest
stream. We thought, "out of sight, out of mind."
We have become painfully aware of the ignorance of
this concept. What we poured down the drain
yesterday is in our drinking water today. Now, we
are more aware of the danger these materials pose to
our environment, especially to our drinking water
supplies. The Underground Injection Control (UIC)
Program was created in response to this new
awareness.
Danger to Groundwater. The UIC Program
regulates the subsurface discharge of pollutants in
order to protect underground sources of drinking
water. Many situations exist that allow damaging
materials to enter the groundwater and contaminate
drinking water supplies. One example is found at
automobile fuel and service stations, body shops,
rustproofing operations, and automotive
dealerships. These businesses often have floor
drains located in service bays. If the drains are
connected to shallow disposal wells or septic tanks,
materials such as gasoline, oil, antifreeze,
transmission fluid, brake fluid, and kerosene can
enter the drains and adversely effect the groundwater
around the site. Contamination of nearby drinking
water wells could occur. To avoid increasing
contamination, these types of discharges are now
prohibited in Wellhead Protection Zones, which are
areas containing significant underground sources of
drinking water.
The Department of Environmental Protection has
established several Best Management Practices to
assist people located in Wellhead Protection Zones
in complying with state laws and regulations. For
example, in areas not served by a sewer, floor drains
are not permitted unless connected to a holding tank
with automatic shut-off or high level alarm.
Holding tanks (including oil/water separators)
containing hazardous waste must be pumped by a
licensed hazardous waste hauler and shipped with a
legal manifest (shipping document) to a licensed
factility for recyling or disposal. Holding tanks (or
oil/water separators) containing waste oil may be
pumped by a licensed waste oil dealer and hauled to
a waste oil recycling facility.
Floor drains connected to dry wells, cesspools,
septic systems, and other types of wells regulated by
the UIC Program are prohibited in Wellhead
Protection Zones. These disposal methods are a
major source of pollution. Leaching of motor oil,
brake fluid, anti-freeze, etc. will occur and will
contaminate underground sources of drinking
water. Corrective measures include digging up the
wells, removing the contaminated soil, installing a
holding tank, and often finding new drinking water
supplies for a neighborhood or entire town.
Danger to Surface Water. Interior floor drains
discharging directly or indirectly to surface waters
are another potential danger. Spills can occur, and
floor washdown will enter the floor drain. The
discharge of waste oil, contaminated wastewater,
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and hazardous wastes would result in the
contamination of surface waters. Discharges of this
type are not allowed. All other discharges to surface
waters require proper treatment, and a waste
discharge license from the DEP. For more
information on discharges to surface waters, contact
the Division of Licensing and Enforcement within
the Bureau of Water Quality Control at the DEP at
289-3901.
Sanitary Sewer Connections. Floor drains
connected to the sanitary sewer are subject to the
regulation of the local sewer district. State law
prohibits the unlicensed discharge of oil, gasoline,
and hazardous waste to the sanitary sewer. In
addition, many towns have ordinances prohibiting
similar discharges to the sewer system. Some towns
allow floor drain connections to the sanitary sewer if
the discharge is pretreated. Local ordinance may
require that a floor drain be connected to an oil and
grit separator that collects heavier-than-water runoff
before discharging the relatively "clean" water to
the sewer system. For more information on sewer
connections of floor drains, contact your local sewer
district.
Hazardous wastes. Hazardous wastes typically
generated at automobile service stations include
waste solvents from parts cleaning, waste paint
thinners, waste battery acid, and hot tank caustic
cleaners. These wastes must be segregated from
wastewaters, waste oil, and other wastes. Businesses
that generate less than 220 pounds or 25 gallons per
month or accumulate no more than 220 pounds of
hazardous waste at any one time may qualify as
"small quantity generators." At a minimum, such
generators are required to label, properly package,
ship, manifest and use a licensed hazardous waste
tranporter to ship the materials to a hazardous waste
facility. If you generate more waste than the amounts
described above, the requirements are more detailed.
For more information on hazardous waste generator
requirements, contact the Division of Licensing and
Enforcement in the Bureau of Oil and Hazardous
Materials Control at the DEP at 289-2651.
THE SOLUTION. How can you help protect our
drinking water supplies?
1. Substitute. Substitute non-hazardous materials
whenever possible. Environmentally, this is the
preferred solution.
2. Segregate. Segregate waste oil for recycling.
Waste oil may be offered for sale or used as a fuel
supplement if it meets certain standards, has not been
mixed with any hazadous waste, and does not exhibit
any hazardous waste characteristics.
3. Recycle. Use a recycling service to periodically
pick up spent solvents and other hazardous materials,
and replenish your supply. Due to the complex
nature of the requirements concerning the handling,
storage, and disposal of hazardous wastes, many
service stations have minimized the amount of
solvents, paint thinners, and caustic cleaners they use
in order to qualify as small quantity generators.
Many small quantity generators (as well as large
quantity generators) have found contractual
recycling services to be an efficient way to remain in
compliance with the disposal requirements.
Companies offering such services must be licensed
by the DEP as a hazardous waste transporter. Fora
complete list of licensed hazardous waste
transporters, contact the Division of Licensing and
Enforcement in the Bureau of Oil and Hazardous
Materials Control at the DEP at 289-2651.
THE FUTURE. Some of the materials we use on a
daily basis cannot be "disposed of - they will be
with us forever. Whatever was disposed of
improperly in the past is now part of our
environment: the air we breathe, the food we eat, and
the water we drink. Now we must make every effort
to handle materials such as waste oil, hazardous
waste, and contaminated wastewater properly.
Proper use and disposal of these materials is vital to
avoid further damaging one of our most precious
resources ~ water.
For more information, please contact:
Department of Environmental Protection
Bureau of Water Quality Control
State House Station #17
Augusta, Maine 04333
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PLANNING TECHNIQUES FOR ESTIMATING GROUNDWATER IMPACTS
OF ON-SITE SEPTIC SYSTEMS
Elizabeth Beardsley and Carol Lurie
Camp Dresser & McKee Inc.
One Center Plaza
Boston, MA 02108
Abstract
In New England and in many other parts of the country, a large proportion of the
population relies on individual on-site septic systems. Septic systems rely on
several processes for purification of vastewater and pose a potential risk of
contamination to groundwater, particularly in areas with highly permeable soils,
high groundwater, or bedrock fractures. Cumulative effects of septic systems
make pollution from septic systems a serious hazard to groundwater.
There are two distinct approaches to planning and management of individual septic
systems: maintenance/rehabilitation of existing systems, and proper siting of
future systems. Maintenance, upgrade, and/or rehabitation of existing systems is
critical to prevent pollution of groundwater and is a method for managing
existing situations. Planning for the adequate siting of systems, however, can
prevent future contamination problems.
Two analytical planning techniques can be used to assess the impact of individual
septic systems from residential development on groundwater quality: residential
build-out analysis and nutrient loading models.
A residential build out analysis is a technique for determining the number of
residences which can be built in a given area. This number is compared to the
number of existing residences to estimate the potential impacts of residential
growth. An important consideration of bulid-out analyses is that their accuracy
is dependent on that of the data. Realistic soil data, in particular, is needed
to estimate the areas which are unbuildable, and, through the build-out analysis,
project the potential number of residences and septic systems. Build-out
analysis is best used as a rule of thumb analysis to give an idea of order of
magnitude of a situation, and to identify geographical areas of concern.
Nutrient loading calculations are performed to estimate the nutrient contribution
from septic systems to groundwater. There are several different nitrate loading
models which are in use. These models are usually based on a loading rate which
assumes that total nitrification occurs in the system and have the advantage of
minimal data requirements compared to more advanced groundwater models. Nitrate
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loading is an important technique because it is the most readily available method
for quantifying the cumulative effects of septic systems on groundwater.
However, applications of this technique should be undertaken with a thorough
understanding of its inherent assumptions.
Septic system siting is regulated at the state level. Existing septic system
regulations of most New England states are limited in that they do not contain an
upper limit on permeability, and by the regulations' site by site, rather than
cumulative, approach to management of septic system siting.
Introduction
The National Well Drillers Association ranks septic systems third in order of
importance as groundwater pollution sources, behind landfills, and lagoons and
other waste pits. Septic systems pose a potential risk of contamination to
groundwater, particularly in areas with highly permeable soils, high groundwater,
or bedrock fractures. In New England and in many other parts of the country, a
large proportion of the population relies on individual on-site septic systems.
Cumulative effects from these systems make pollution from septic systems a
serious hazard to groundwater, and addressing this hazard becomes important as
water supplies become more precious.
How Septic Systems Work
Septic systems are economical on-site structures designed to dispose of household
wastewater underground. They are designed to perform three functions: trap oil
and grease, digest solids, and percolate remaining wastewater into nearby soils.
A schematic diagram of a typical system is shown in Figure 1. A septic system is
made up of a septic tank and a leaching area, both located underground. The
septic tank is a watertight concrete tank with an inlet, an outlet, and manhole
covers which allow access. Household sewage, including wastewaters from the
bathroom, kitchen, and laundry room, flows by gravity to the tank, where solids
-settle to the bottom and form a sludge. Oil and grease float to the surface and
form a scum.
Typical Household Septic Tank System
Cross Section of Typical Concrete Septic Tank
Figure 1: Typical Septic System
(Source: Lake Cochituate Watershed Association, 1985)
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If the septic system is operating properly, bacteria grow in the septic tank and
reduce some of the sludge and scum to liquid by digestion and partial
decomposition. Oil and grease are not fully digested, but are trapped until
removed from the tank by pumping.
The remaining "conditioned" wastewater flows through the outlet to the leaching
area. The outlet is positioned below the water surface so that the oil and
grease scum remains in the tank. The leaching area may be a leaching field,
leaching pit, or leaching trench, and essentially consists of a distribution box
and several perforated pipes laid in gravel-lined trenches. The purpose of the
leaching area is to disperse wastewater into the soil.
As wastewater percolates from the pipes through the stone and soil, contaminants,
including nutrients, are removed from the wastewater in several purifying
processes. Viruses, nutrients, and bacteria adhere to soil particles, nutrients
are then consumed by organisms in the soil, and consumed by plants. If the
septic system is functioning correctly, the wastewater will be of non-polluting
quality by the time it reaches groundwater resources. Figure 2 illustrates these
processes.
EVAPORATION
PRODUCTION
111111 M 1111111
IIIIIIIIIIIIIUIllllllllllllll
f
IIMIMIIIIIIIIIIIIIIIII
2 feet
mposition
nitrification
danttriflcation
adsorption
• SURFACE WATERS
Adapted from Quadn ,1984-,Frimpter at al,1988.
Figure 2: Subsurface Disposal Processes
Impacts of Septic Systems on Groundwater
Household sewage typically contains subtantial concentrations of ammonia-
nitrogen, phosphorus, and oil and grease, as well as biological oxygen demand
(BOD), chemical oxygen demand (COD), and suspended and dissolved solids. Average
characteristics of household wastewater discharged to septic systems are shown in
Table 1.
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Table 1: Characteristics of Influent Wastewaters to Septic Tank Systems
CONSTITUENT CONCENTRATION (mg/l)
^m^^mm^u^^^^^^*^^*^^^^*^^
BOD
COD
TOO
TS
S3
TKN
Ammonto-N
TP
PhmhaU
OlandQnu*
•^•^•^•^•^•^•^•^•^•^•••^•^•^•^•••••V
300
750
200
780
250
38
12
25
84
04
Souie*: BaiMr. Conrad, and Shtrman. 107B
As septic systems rely on several processes to purify wastewater, there are
numerous conditions which can cause systems to fail to treat household sewage
adequately. The numbers and densities of septic systems make pollution of
groundwater from septic system effluent a significant concern.
One recent public education brochure puts the problem in these terms:
"The indirect discharge of pollutants from improperly located, malfunctioning
or crowded septic systems plus pollutant-rich urban stormwater discharges
cause major problems to the waters of New England. The addition of nutrients
and pathogenic organisms present a potential hazard to both human health and
the water quality of our lakes." (Lake Cochituate Watershed Association,
1985).
The Cape Cod Planning and Economic Development Commission (CCPEDC) has correlated
the increase in groundwater nitrate concentrations with an increase in housing
and septic system density. Contamination from septic systems is a serious threat
to the groundwaters of New England.
Groundwater pollution from septic systems has several different causes:
(1) poor siting of system
soils that do not adequately filter the wastewater before it
reaches groundwater (including excessively permeable soils)
too many systems in a given area, leading to significant cumulative
impacts
(2) poor design and/or construction
tank and/or leaching area undersized
designed for seasonal use and converted to year-round
(3) maintenance or operations problems
leaks in pipes or in the tank
sludge build-up in the tank, leading to overflow and soil clogging
scum build-up
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Groundwater contamination from septic systems with maintenance and/or operational
problems can be prevented by remediation. However, groundwater contamination
from septic systems that are poorly sited cannot easily be mediated. For this
reason, individual and overall siting of septic systems is extremely important.
The main concern, then, for groundwater pollution is the quality of the effluent
from the septic tank portion of the system, and the efficiency of contaminant
removal in the soil underlying the leaching area (Gather, 1985). This efficiency
in constituent removal is affected by several criteria:
the soil character
soil permeability and percolation rate
depth of soil below leaching area to groundwater
presence of clay or impermeable layers
presence of cracks in bedrock
The importance of this concern is supported by the literature, although most
studies cited in the literature appear to have been concentrated on the
efficiency of the septic tank portion, with fewer studies investigating the
leaching area. One research study involved sampling of groundwater under and
adjacent to leaching fields (Cogger et al, 1988). A strong relationship between
wastewater loading rate and nitrate concentration was observed. In addition,
there was a direct relationship between the depth to groundwater and the level of
denitrification which occurred.
For wastewater to be adequately filtered, a certain contact time between the
water and the soil is required. If the soil is not permeable enough, or if a
clay layer is present, a failure will occur, and wastewater may be diverted, such
as through horizontal movement. Furthermore, if the soil is excessively
permeable, it is not able to provide attentuation of contaminants because of the
speed at which the wastewater moves. The depth from the leaching area to
groundwater is important because it is related to the contact and filtering time;
if the depth is insufficient, water will not be sufficiently treated. The
combination of excessively permeable soils and high groundwater conditions is
especially prone to insufficient wastewater purification.
Although septic systems are regulated at the state and local levels, most
regulations are based on a maximum percolation rate (i.e., limit slow
permeability), and do not have a minimum percolation rate. The regulations
neglect to consider potential pollution resulting from siting in excessively
permeable soils. As a result, overall siting of septic systems is inadequate to
protect groundwater.
Planning to Prevent Potential Contamination
An ample body of knowledge exists on how to prevent septic system failure and
malfunctioning through proper maintenance. Recently, it seems that much interest
has been shown in improving the public awareness and use of preventive measures
such as pump-outs at regular intervals and water conservation. From our
observations, cities and towns are becoming interested in enforcing septic system
repairs; in some cases they are mandating septic system maintenance (for example,
the Rhode Island On-site System Maintenance Act).
Repair and maintenance are important; however, they come into play after the
septic system is in place. An important consideration is proper siting of the
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system. If improperly placed, failure and/or groundwater pollution is inevitable
if soil characteristics and other site conditions are not conducive to wastewater
treatment. For example, nitrate-nitrogen, a known public health problem in
groundwater, may persist if sited in excessively permeable soils even if a system
is properly maintained. Groundwater contamination may occur even if the system
has not visibly failed (i.e., if there are no back ups).
Maintenance, upgrade, and/or rehabitation of existing systems is critical to
prevent pollution of groundwater and is a method for managing existing
situations. Planning for the adequate siting of systems, however, can prevent
future contamination problems. If the cumulative contamination of groundwater by
septic systems is to be prevented, the siting of septic systems must be improved.
Planning Techniques
While on-site septic disposal systems are generally not a problem to groundwater
(unless sited too close to wells) when considered individually, the cumulative
impact of many septic systems in areas characterized by unsuitable soils or other
conditions suggests the need for the development of a land use management
strategy to reduce or offset this potential cumulative impact.
This paper examines two related analytical planning techniques used in
determining the impact of individual septic systems from residential development
on groundwater quality: build-out analysis and nutrient loading.
A residential build-out analysis is a technique for determining the number of
residences which can be built in an area served by septic systems, as permitted
by regulatory requirements as well as environmental constraints. This number is
compared to the number of existing residences to study the impacts of residential
growth. Nutrient loading calculations are used to estimate the nutrient
contribution from septic systems to groundwater. Nutrient loading analyses for
nitrates are examined, and conditions and assumptions which limit the
applications of nutrient loading are discussed.
Build-out Analysis
The first step in understanding the magnitude of the possible or existing impact
from septic systems in an area served exclusively by on-site septic disposal
systems is to estimate the potential for development of dwelling units with
associated septic systems in the area. This can help determine possible future
environmental and water quality conditions. One method of determining the
current and future development potential of an area, and by implication the
cumulative impact of septic systems, is by conducting a build-out analysis.
A build-out analysis estimates the maximum amount of dwelling units that can be
built in a defined area based on current zoning and land use regulations, and
regulations governing the location of septic systems. Environmental factors,
including soil characteristics, wetlands, topography, and groundwater levels are
specifically taken into account, often using a series of graphic map overlays.
The estimated number of septic systems in a study area can then be used as a
basis for the nutrient loading calculation to project potential impacts from
septic systems to groundwater resources.
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The build-out analysis assumes that the major current regulatory requirements are
followed. For Massachusetts, these regulations include:
Zoning Regulations
the Wetlands Protection Act
Regulation of Septic System Location and Design (Massachusetts Title V)
There are two main approaches for conducting a build-out analysis:
1) Parcel-by-parcel build-out (tabular or graphical)
2) Generalized build-out (graphical)
In the town of Hopkinton, Massachusetts, we applied the first methodology to
determine the different impacts on land use between residential development using
traditional on-site septic disposal systems versus the use of small private
treatment plants. In the town of South Kingstown, Rhode Island, we conducted a
generalized build-out analysis for several watersheds, the results of which were
used to project the impact of development through nutrient load modeling and
resultant water quality implications.
Build-out Methodology
Essentially, the build-out analysis has three major steps:
A) Determination of vacant developable land
B) Determination of vacant developable land by zoning district
C) Calculation of the potential number of dwelling units (and septic
systems) that could be built in an area
The analysis is conducted by developing a series of map overlays. We have in
some cases used a Geographic Information System (GIS) as a tool in this process.
These steps and components of the build-out analysis are detailed below.
A) Determine vacant developable land
1. Map soils that cannot be built on
Soils cannot be built on for two reasons: (1) the soils
(topography) are too steep to build a residence economically, or
(2) the soils do not meet the minimum requirements to install a
septic system to serve the residence.
For the town of South Kingstown, a map overlay was developed based
on the classification of soils by the U.S. Department of
Agriculture, Soils Conservation Services (SCS). Soils are
classified as severe for septic systems when they exhibit a high
groundwater table, slow percolation rates, susceptibility to
flooding, presence of rocks and boulders, slope, and/or excessive
permeability. Unsuitable areas were then mapped on an overlay.
For the town of Hopkinton, the Soil Conservation Service data was
translated into the criteria specified by Title V, the state
regulation which governs the location and design of septic systems.
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Areas which did not meet minimum criteria, according to SCS data,
were mapped as unbuildable on an overlay.
2. Map wetlands
Wetlands are a constraint to development because federal and state
regulations often restrict filling of wetlands. An overlay map of
wetlands is compiled based on the best available data. This may be
town maps, the U.S. Fish and Wildlife Wetlands Inventories,
U.S.G.S. topographic maps, or aerial photographs.
3. Create composite environmental factors map
The next step is the creation of a composite map of soils and
wetlands that shows the environmental factors that limit
development potential.
4. Map existing land use and developed/undeveloped land
An existing land use map is then developed which shows areas in the
study area that are used for different purposes such as
residential, commercial, industrial, municipal, transportation, and
recreational uses. Maps are either developed from existing
information, or through interpretation of aerial photographs.
The land use categories are divided into two groups - developed and
undeveloped. Developed uses would include those already committed
for use such as residential, commercial, industrial, paved areas
such as highways, and conservation land. Land uses considered
undeveloped include vacant areas, agricultural land (not under
permanent development restrictions), golf courses, or any land
within a community that has the potential for being developed.
Land use categories vary according to study area. Areas which are
undeveloped are identified for input to the next step.
5. Map vacant developable land
The next step in the process creates a map showing land that is
vacant and can be developed (developable). The environmental
constraints composite map is overlain with the land use map. A map
is created showing only land which is undeveloped and has no
environmental constraints, termed "vacant and developable" land
(see Figure 3). This map thus takes environmental factors as well
as existing land use into account.
B. Determination of vacant developable land by zoning district
Once the vacant and developable land is identified, the zoning of the
municipality is taken into consideration.
6. Map zoning districts
The zoning map of the municipality is then superimposed onto the
vacant developable land map. This composite map forms the basis
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Single Family
Multi-Family
S Agricultural
39 Water
QD Educational
59 Commercial
QD Institutional
LAND USE
Developed Land
£3 Environmental
D Vacant Land
VACANT
DEVELOPABLE
LAND
Figure 3: Land Use and Vacant Developable Land
for calculating the potential number of dwelling units by zoning
district.
C. Calculations
7. Measure vacant developable land by zoning district
All areas of vacant developable land falling within each zoning
district are measured. This calculation is simplified if the
mapping is done using a Geographic Information System (CIS).
8. Subtract a percentage for roads and infrastructure
In order to estimate future residential dwelling development
potential, a percentage must be subtracted for land that would be
used for roads, utilities, service easements and other municipal
uses. Typically a factor of fifteen percent is used for
residential development.
9. Calculate the number of new dwelling units
After the total area of land available for building lots is
calculated, the next step is to calculate the number of possible
dwelling units for each zoning district. This is based upon the
minimum lot size requirements as specified by the zoning code.
Each vacant developable area is evaluated in terms of the
permissable number of dwelling units per acre. If the build-out
analysis is being conducted on a parcel-by-parcel basis, several
scenarios may be developed to project different development
patterns which are possible.
10. Calculate the total number of dwelling units and septic systems
Based on the above, the next and final step is to add the potential
number of dwelling units that could be built to the number of
dwelling units that already exist in the study area. The existing
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number of dwelling units, or base case, is determined through
examination of aerial photographs, field checking, and examination
of septic system permits and other town records.
The total number of existing and potential dwelling units and
associated septic systems serving these residences is used as a
basis for calculating nutrient loading on water resources of the
study area.
The build-out analysis thus gives an estimate of the current and future
development potential of an area, and the potential number and location of
on-site septic systems that could be built.
Nutrient Loading Analysis
Nutrient loading analysis is a technique which has been used increasingly as a
tool for determining the density of development that can be sustained given soils
conditions. Nutrient loading utilizes the location and/or number of septic
systems and loading rates to determine the nutrient load to groundwater. It is
sometimes carried further and is used with groundwater flow and quality data to
project the concentration of a parameter resulting from a specific development.
While nutient loading analyses can be performed for phosphorus and other
parameters, this paper focuses on nitrogen, specifically nitrate-nitrogen.
Nitrogen Loading Analysis
Nitrogen loading analyses may take several varied forms. In general, the
analysis involves multiplying the number of septic systems by the quantity of
nitrogen present in the effluent over a given period of time. In different
models or applications, this quantity may be input to other equations to
determine concentration.
The simplest nitrogen loading calculation involves multiplying the number of
actual or potential septic systems in the study area by a loading rate:
N03 load = (Ibs/system/yr) X (systems)
N03 load = (Ibs/person/yr) X (persons/residence)(# residences)
The loading rate is usually in Ibs/person/year, with the result in Ibs/year. It
may be necessary to understand the demographic characteristics of the study area
to determine the average number of persons per residence or septic system.
This technique was used in South Kingstown in conjunction with the build-out
analysis. In the South Kingstown study, the town wanted to predict the effects
of development on several salt ponds which were largely fed by groundwater.
Using nitrogen loading rates, an annual nitrogen budget was developed to show the
nitrogen contribution, in pounds, from different sources such as septic systems,
agriculture, fertilizer, roads, runoff, and precipitation. These calculations
were performed for the existing situation, and also for the build-out condition,
under which many more houses and septic systems would be present in the
watershed.
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Several models have been developed for Cape Cod, Massachusetts. Cape Cod is
characterized by sandy soils which are well to excessively drained, and is a sole
source aquifer. The combination of these environmental conditions and rapid
development rates have caused concern over septic system effects, leading to
modelling efforts, notably by the Cape Cod Planning and Economic Development
Commission (CCPEDC).
The model developed by CCPEDC models the dilution of nitrate moving from septic
systems into groundwater (Quadri, 1984). The model assumes a complete mixture of
two volumes - recharge and septic system effluent - and the formula solves for
the mixture concentration:
N03
concentration
in
groundwater
(recharge vol)(recharge cone.) + (system vol)(system cone.)
recharge volume + system volume
The nitrate concentration of septic system effluent is estimated using standard
septic system flow estimates, and per-person nitrogen loading rates. (This
assumes total conversion of ammonia to nitrate.) CCPEDC has used this model to
estimate the density that can be supported while maintaining desired nitrate
levels in groundwater.
A more advanced version of this nitrogen loading model was developed as part of
the Cape Cod Aquifer Management Project (CCAMP) (Frimpter et al, 1988). The
model presented is more detailed, and is adapted for use specifically in
predicting nitrate concentrations in municipal wells. This model allows for
inclusion of sources other than septic systems:
N03
concentration = nitrate from precipitation + nitrate from sources
in groundwater total volume
(simplified form)
Precipitation and well withdrawal take the place of recharge. Generally,
however, the two models operate on the same principles of total mixing and
dilution.
Other models, such as for Winnebago County, Illinois, involve extensive
groundwater sampling to construct complex mass balance relationships (Jaffe and
DiNovo, 1988).
To assess the impacts of a proposed residential and resort development, one
method used nitrogen loading as a check for a more sophisticated and complex
solute transport model (Atwood, 1989). The solute transport model is more
advanced, but has greater site-specific data requirements, including groundwater
flow, quality, boundary conditions, water table contours, and hydraulic
conductivity. This data is used in solute transport equations which solve for
concentration at different locations of the site. A more advanced model such as
this has the advantage of probable greater accuracy and gives concentrations for
various locations on the site (rather than a single value); however, required
data is often not available, especially for large-scale planning applications.
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Nitrogen loading calculations similar to those developed by CCPEDC were used to
check the validity of the solute transport model.
In Acton, Massachusetts, a different approach was used (Jaffe and DiNovo, 1988).
In this case, the base flow water quality of streams in the study area was
assumed to be proportional to the number of septic systems in the drainage basin.
Once this proportion was established for the existing condition, the effect of
build-out on groundwater could be estimated. This model was used to determine
the maximum density to result in a certain concentration without reliance on a
per-person type rate.
Nitrogen and other nutrient loading models vary from the very simple to the very
complex. Generally, models are based on the concept of septic systems as a
significant, or in some models as the significant, source of nitrate-nitrogen to
groundwater, and are based on a loading rate in the units Ibs/systern/year.
Applications and Implications
Build-out and nitrate loading analyses can be used to assess present and future
effects of septic systems on groundwater. These techniques are useful in
large-scale applications or where limited site-specific data is available. These
planning methods have many different applications and also involve certain
assumptions and implications, as discussed below.
Build-out Analysis
The purpose of the build-out analysis is to estimate the development potential of
an area. The build-out analysis is a very useful tool, but like any simplifying
model, must be only used where appropriate.
Applications. There are many different applications and forms of build-out
analysis.This paper applies the build-out analysis to residential development
utilizing septic systems, which can then be used with nutrient loading analyses.
Build-out analysis of this type is only suitable in an area that is exclusively
served by septic systems. Some other applications of build-out analysis include
maximizing the area of commercial development, and making population and
infrastructure estimates.
Build-out analyses vary in complexity and scale. Some analyses are conducted on
a parcel-by-parcel basis, involving the use of assessors' maps. Generalized
analyses utilize available land use and natural resource maps, usually at a
smaller scale which precludes consideration of individual parcels. Build-out
analyses can be very simple, utilizing existing data, or complex, requiring
extensive data collection and scale transformation efforts. Most build-out
analyses are based on spatial relationships.
Parcel-by-parcel analyses have a greater degree of accuracy and of precision.
However, there may be some loss of accuracy in the application of soil and
wetland constraints, if soil and wetland data is available only at a coarser
level of detail than the parcel size. Also, the parcel-by-parcel analyses are
more time-consuming. Generalized build-out analyses can be somewhat less
accurate than the parcel-by-parcel, but the result is valid as an estimate of the
magnitude of potential growth, rather than a precise number of dwelling units.
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Accuracy of Data. A build-out analysis is only as accurate as its data. In most
cases there are several different data sources involved, each at a different
level of detail and from different base years. Soil and wetlands data vary
substantially in accuracy, and it is imperative that inconsistencies or
limitations of the data are factored into the analysis.
Soils data, in particular, are problematic. If the goal of the analysis is to
determine the number of units which can be built in compliance with regulations,
the soil parameter values which are selected as constraints must be the same as
those unsuitable in the regulations. Translating municipal or regional data
sources to these site-specific parameters can be difficult.
For a build-out analysis in Haverhill, Massachusetts, Soil Conservation Service
soil maps were found to be misleading in terms of whether the area could actually
be developed with a septic system. For many areas, the SCS data indicated
inadequate permeability; however, Board of Health records showed that very few
lots failed to pass a percolation test. Since SCS data suggested that
development could not occur, yet local experience showed that these areas were
allowed to develop, soil factors (in the form of percentages of watershed area)
were developed to account for the soil developability, based more heavily on
slope and rock outcrops than permeability.
The actual areas where septic systems cannot be built could also depend to some
extent on the rigorousness of the Board of Health or agencies permitting the
systems.
In states where regulations do not limit septic system siting in excessively
permeable soils, such soils should not be considered to be constrained from
development. Although these soils may be unsuitable from a groundwater pollution
standpoint, they can (and will) be developed with a septic system and be in
accordance with the regulations.
Validity of Result. While the build-out analysis projects the state of
development when all available land is built upon, the build-out does not imply
that the development will actually happen. The likelihood of development
occuring is dependent on inter-related factors such as the economy, real estate
market, and population trends in the region. In view of these considerations, it
is difficult to bring in a temporal factor, which would be needed to estimate the
phasing of potential development.
Use of Result. Build-out analysis is best used as a rule of thumb analysis to
give an idea of order of magnitude of a problem. It is also well-suited to
identify areas of concern - such as large developable areas without
infrastructure or conservation protection.
Nitrate Loading
Nitrate loading is an important technique because it is the most readily
available method for quantifying the cumulative effects of septic systems on
groundwater. The purpose of nitrate loading calculations is to project the
potential impact of septic systems to groundwater. The result of calculations is
usually in the form of Ibs/year, and can be used as input to further calculations
to project a concentration (i.e. in units of mg/1 or ppm).
249
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Nitrogen loading is important to consider because excess nitrogen loading to
soils can result in conditions of elevated nitrate or ammonia in groundwater
which in turn can cause health problems and/or contaminate wells beyond use. An
understanding of nitrogen loading prior to development is imperative if nitrogen
contamination of groundwater from septic systems is to be minimized.
Applications. There are numerous ways in which nitrate loading calculations are
used. Nitrate loading can be used:
a) for site-specific impacts
b) to evaluate the use of septic systems versus treatment
c) to determine the maximum number of septic systems that could be
supported
d) for an existing situation to determine the percentage of nitrogen
contributed by septic systems
e) to assess future conditions in conjunction with build-out analysis
The loading rate is often applied in site-specific applications as part of
overall nitrogen budgets or in predicting nitrate concentrations in groundwater.
For example, the South Kingstown study calculated nitrogen loads to salt ponds
from septic systems and other sources within the watersheds for the present
situation and the future. These numbers were used to determine the relative
present and future importance of each source of nitrate. Other applications use
nitrogen loading on proposed development sites to determine if on-site septic
systems could be used, or if wastewater treatment is required.
In some circumstances, the calculations are used to make non-specific findings,
such as a general determination of the maximum number of septic systems which
could be supported while maintaining groundwater quality at a certain nitrate
level. For example, nutrient loading was used in a general application by CCPEDC
to calculate the lot size appropriate for septic systems on Cape Cod. When using
the results of a general analysis like this in large-scale planning, it is
imperative to consider the nature of the model, which by nature does not consider
existing nitrate levels, groundwater flows, hydrogeology, and other nitrogen
sources.
Nitrate loading calculations can be dependent or independent of build-out
analysis. In some cases, it may be desired to compute nitrogen loading for an
existing situation, without consideration of future development. For example,
nitrogen loading calculations might be used to determine whether septic systems
are a significant contributor to known groundwater pollution compared to other
sources within a watershed. This might be done through comparison of annual
loads without needing to calculate nitrate concentrations. This has the
advantage of avoiding inherent uncertainty associated with assumptions involved
in the concentration calculations.
To project future groundwater pressures, nitrogen loading calculations must be
used in conjunction with build-out analysis. The result could again be either an
annual load or a projected concentration.
Accuracy of Data. The simplest of nitrate loading models requires for data the
number of existing or potential septic systems, and the nutrient loading rates.
The number of existing septic systems is generally readily estimated, and the
number of potential systems can be projected with the build-out analysis to a
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certain level of accuracy. The accuracy of these simplified nitrate loading
analyses hinge on the appropriateness of the nitrate loading rates.
Nitrate-nitrogen loading rates vary; values used in studies cited herein ranged
from 5 Ibs/person/year to 10 Ibs/person/year. Nitrate loading rates are based on
research which was focussed on estimating flows and contaminant loads to
treatment works, and on some actual monitoring of effluent. These rates are
based on assumptions which include the level of nitrification and the degree of
attenuation through the soil. One rate assumes total nitrification in the septic
system, with no removal of nitrate in underlying soils (Frimpter et al, 1988),
while another assumes 50% nitrification only (COM, 1988).
Nitrogen loading rates were originally developed from septic system research in
1960s and 1970s which was concerned with flow volumes and with the load to the
septic tank rather than the effluent from the leaching area. Recent research in
the area of the actual quality of effluent which leaching fields are discharging
to the ground, and the actual degree of attentuation which various soils are
acheiving in view of different groundwater conditions appears to be lacking.
It is valuable and important to consider the assumptions involved with a
particular rate before its application. It may not be accurate to apply the same
rate to different soil and geohydrologic conditions. Septic tank and leaching
field performance will shape the degree of nitrification which occurs, while
underlying on-site soil conditions and the depth to the water table will affect
the degree of attenuation of nitrate.
One main advantage of nitrate loading is its minor data requirements. The data
necessary to use a more advanced model, such as a solute transport model, is
often not available. Nitrate loading, with all its inherent assumptions, is a
valuable tool for estimating the nitrate contribution of septic systems relative
to other nitrate sources, or for projecting the increase in nitrate load with
development. The projection of nitrate concentrations in groundwater should be
made only with an understanding of the assumptions of the analysis.
Use of Result
In view of the assumptions used in nitrate loading analyses, there are several
ideas to consider in application of the analyses and results. First, there are
problems with transferring loading rates and other absolute numbers from one
study area to another. These rates were developed in part from well-used data
concerning sewage generation, but are also based on nitrification, attenuation,
and other processes which may be shaped by site-specific conditions. An
understanding of on-site soil properties and the processes assumed in the
development of a specific loading rate are advisable.
One good use of the analysis is to estimate the nitrate contribution from septic
systems relative to other sources. While this application still relies on the
loading rate, the same assumptions involved can be used when estimating the
contribution from the other sources. The result of this application is a
relationship, rather than an absolute number. The use of nitrate loading with a
build-out analysis is also useful to project change in nutrient load and relative
contribution of nitrate.
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Regulation of Septic Systems
Build-out and nutrient loading analyses are techniques which help to assess
cumulative impacts of septic systems and development. In order to minimize the
potential for contamination of groundwater from septic system effluent, siting of
septic systems should consider cumulative effects. Currently, however, siting of
septic systems is mainly regulated on an individual system basis.
The siting, as well as the design and installation, of septic systems are
regulated on a state and local level. Regulations typically use parameters such
as soil type or classification, percolation rate, depth of permeable soil, depth
to seasonal high water table, and depth to bedrock to site septic systems.
Regulations also contain setback requirements and detailed sizing and design
guidelines. Table 2 lists selected standards for septic system siting for
several New England states.
Table 2: Septic System Regulations of Selected States
/
SITE CONDITIONS
PERCOLATION RATE:
SLOW LIMIT
FAST LIMIT
SOIL DEPTH ABOVE
HIGH WATER TABLE
SOIL DEPTH ABOVE
IMPERVIOUS LAYER
OR BEDROCK
SLOPE
pHHAyHBBH
30 min/in
None
4 feet
4 feet
slope constrained
by lateral distance
requirements
J^HdHHHH
40 min/in "
None
4 feet
5 feet
HmAiB^B
60 min/in •
4 feet
6 or 8 feet
35%
.--.: - - ' '
Kara
60 min/in
1 min/in
3 feet
3 and 4 feet
10% (trench)
20% (bed or pit)
•nin^Hi
system baaed on
soil profile tenure
15 - 48 inches
15-48inchee
10% (trench)
20% (bed or pit)
(1) Regulations shown apply to leaching bed systems.
" Certain soil types that are floodplain soils or very poorly drained
** 20 min/inch over 2000 gpd.
Analysis of these regulations show that in most states, there is no consideration
for excessively permeable soils. That is, siting regulations rely upon minimum
percolation rates. The installation of a septic system in excessively permeable
soil (i.e., with a percolation rate of 1 min/inch) will be acceptable from a
regulatory standpoint, but is likely to be a potential source of contamination.
When systems are placed in such excessively permeable soils, and high groundwater
and/or shallow depth to bedrock is present, that septic system has a strong
potential for contamination of groundwater.
Other problems with regulations are that often, percolation tests may be repeated
until one test is adequate, although the soil may not be suitable for attenuation
of wastewater on a daily basis. In some areas, soil testing can be done at any
time of year. The depth to groundwater distance (i.e., high water level) may not
be accurate if measured in fall or winter.
The most serious limitation of the regulations in general is their site by site,
rather than cumulative, approach to management and location of systems. Nitrat
loading analyses show that when considered on a cumulative basis, the impact is
considerably greater than the impact of individual systems is believed to be, and
support the need to reevaluate the way that the management and siting of septic
systems is approached.
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Finally, current regulations generally do not provide for planning on a
large-scale basis. Municipal subdivision regulations often allow for wastewater
planning, but where land is developed by individuals, there is currently no real
method for bringing in considerations of cumulative impacts.
Regulation of septic systems began with the goal of protecting human health from
failed systems and from direct well contamination. Now, regulation of septic
systems must have the goal of protecting groundwater as well as the need to
accommodate development at some level.
Conclusion
Septic systems represent a significant threat to groundwater, as there are
various conditions under which insufficiently treated wastewater can reach
valuable groundwater resources. There is a now serious need for the
consideration of cumulative effects in planning and regulation. This need is
reinforced by results from different build-out and nitrate loading applications.
Build-out and nitrate loading analyses are methods that help to assess cumulative
impacts, but the application and validity of these and other methods must be
developed further. Improvement of septic system siting can occur with increased
research on leaching area effluent volume and quality, the development of
different and realistic loading rates for different hydrogeological conditions,
and development of practical methods for accurately estimating the purification
value of a soil sample.
Regulations in most New England states must be changed to address excessively
permeable soils as a first step, and to allow for large-scale siting and planning
as a second step. Innovative development of ways to incorporate these and other
techniques into general planning must occur to protect groundwater while allowing
development.
In conclusion, build-out and nitrate loading analyses indicate that septic system
are a potential threat to groundwater quality. While maintenance of systems is
important, planning for and regulation of septic system siting must be improved
so that cumulative impacts and excessively permeable soils are considered.
References
Atwood, Heather M. 1989. "Quantifying Septic System Impacts to Groundwater
Systems." IEP Inc.
Bauer, D.H., Conrad, E.T., and Sherman, D.G. 1979. "Evaluation of On-Site
Wastewater Treatment and Disposal Options." U.S. EPA. Cincinnati, Ohio.
Camp Dresser & McKee Inc. 1988. South Kingstown Wastewater Management Study.
Canter, Larry W. and Robert C. Knox~I1985. Septic Tank System Effects on Ground
Water Quality. Lewis Publishers, Inc. Chelsea, Michigan.
Frimpter, Michael H., John J. Donohue IV, and Michael V. Rapacz in conjunction
with The Cape Cod Aquifer Management Project (CCAMP). 1988. A Mass-balance
Nitrate Model for Predicting the Effects of Land Use on Groundwater Quality in
Municipal Wellhead Protection Areas.26 pps.
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Cogger, C.G., L.M. Hajjar, C.L. Moe, and M.D. Sobsey. 1988. "Septic System
Performance on a Coastal Barrier Island," J. Environmental Quality, Vol. 17,
no. 3.
Jaffe, Martin and Frank DiNovo. 1987. Local Groundwater Protection. American
Planning Association. Washington DC. 262 pps.
Persky, James H. 1986. The Relation of Ground-water Quality to Housing Density,
Cape Cod, Massachusetts?U.S. Geological Survey, in cooperation with the Cape
Cod Planning and Economic Development Commission. Boston, Massachusetts. 28
pps.
Quadri, Claire Garrison. 1984. The Relationship Between Nitrate-Nitrogen Levels
in Groundvater and Land Use on Cape Cod.Cape Cod Planning and Economic
Development Commission.
Teal, John M. 1983. The Coastal Impact of Ground Water Discharge; An
Assessment of Anthropogenic Nitrogen Loading in Town Cove, Orleans,
Massachusetts.Woods Hole Oceanographic Institution, Woods Hole,
Massachusetts.
Valiela, Ivan and Joseph Costa. 1988. "Eutrophication of Buttermilk Bay, a Cape
Cod Coastal Embayment: Concentrations of Nutrients and Watershed Nutrient
Budgets," Environmental Management, Vol. 12, no. 4, pp. 539-553.
Carol Lurie, AICP
Community Planner
CAMP DRESSER & McKEE INC.
One Center Plaza
Boston MA 02108
Carol Lurie is a community planner with extensive experience in developing
watershed protection programs, comprehensive planning and community
participation. She coordinated the Haverhill, Massachusetts, Watershed
Management Plan, and the South Kingstown, Rhode Island Wastewater
Management District Plan both of which dealt directly with protecting
groundwater quality in fragile environmental areas. She has a Masters
degree in City Planning from the Massachusetts Institute of Technology, and
is currently assisting the City of Providence in developing the city's
Comprehensive Plan.
Elizabeth Beardsley
Environmental Engineer
CAMP DRESSER & McKEE INC.
One Center Plaza
Boston MA 02108
Elizabeth Beardsley is an environmental engineer and planner with
experience in water quality and watershed protection projects. She was
involved in technical analyses for the Haverhill, Massachusetts, Watershed
Management Plan, including review of water quality data, development of
protection measures, and recommending a water quality monitoring program.
She is also involved with a project for Lake Quannapowitt, in Wakefield,
Massachusetts, under the Clean Lakes program. She holds a Bachelor's
degree in Civil Engineering from Stanford University.
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ROAD SALTING IMPACTS IN MASSACHUSETTS
James K. Barrett
Matthew P. Dillis2
Normandeau Engineers, Inc. has completed an evaluation of impacts
from snow and ice control activities on the Massachusetts State Highway
network. This analysis was done for the Massachusetts Department of
Public Works' (MDPW) Snow and Ice Control Program Generic Environmental
Impact Report (GEIR) released in April, 1989. The GEIR evaluated MDPW's
snow and ice control program and the social, environmental, health and
economic implications of deicing chemicals and abrasives use.
Statistical analyses were performed to develop relationships
between road salt application rates and accident frequency using MDPW's
Material Control System, a computerized data bank listing total salt
use, application rates and spreader route length for each spreader truck
and storm event. An extensive literature search provided statistical
relationships between road salt application rates, annual corrosion
costs and health impacts. Literature searches were also used to develop
the environmental impact costs and economic benefits to commerce related
to snow and ice control.
This analysis concluded that snow and ice control provided economic
benefits in the categories of traffic safety and commerce but created
costs in the categories of corrosion, public health and the environment.
Surprisingly, health effects related to sodium in drinking water were
found to be very low in comparison to corrosion costs. Environmental
costs were also small compared to corrosion but this may be due to the
lack of quantitative information. The GEIR concluded that road salt
impacts could be significantly reduced and substantial financial savings
achieved by optimizing road salt use.
Group Manager, Normandeau Engineers, Inc., Concord, New Hampshire.
2
Staff Engineer, Normandeau Engineers, Inc., Concord, New Hampshire.
255
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James K. Barrett, a Group Manager for Normandeau Engineers, Inc.
possesses degrees in engineering and geology. During his 15 years of
professional experience, he has performed and managed numerous ground
water investigations for municipal and industrial water supply
developments, contamination assessments and hazardous waste
investigations. Mr. Barrett's experience includes dewatering
investigations and water quality impacts analyses for major mining and
mill tailings disposal projects; water supply well field design and
installation; hazardous waste investigations at NPL sites throughout the
U.S.; design of ground water monitoring programs and water quality
sampling networks; aerial photography interpretation; isotopic studies;
and computer modeling.
The Massachusetts Department of Public Works has decided to extend
their level of research, therefore the project is still ongoing.
If you would like a copy of the final paper, please contact the author
at (603) 224-5770
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AN EPA/LOCAL PARTNERSHIP AT WORK -
THE CREATION OF A GROUND WATER PROTECTION PROGRAM
Stuart Kerzner
US EPA, REGION III
GROUND WATER PROTECTION SECTION
841 CHESTNUT BUILDING
PHILADELPHIA, PA 19107
Abstract
The Region III Ground Water Protection Section is using
Geographic Information System (CIS) technology to work with
local water resource agencies to develop and implement county-
wide ground water protection plans. The purpose of working with
local agencies is to identify and target for priority regulatory
attention those areas that are susceptible to contamination. The
GIS technology enabled EPA to provide technical assistance to
local agencies in a program with limited federal resources.
The GIS case study demonstrated the use of GIS technology in
ground water protection applications and illustrates how the
Region and the local officials worked together to develop a
mutually beneficial ground water protection program. Program
development, data collection, map coverage construction,
composite map construction and evaluation are topics of
discussion. Emphasis is placed on the application of GIS, its
potential for protecting underground sources of drinking water,
and its impact on management-making decisions. Major project
benefits to the local agency and to EPA are also presented.
Introduction
GIS is a computerized system used for the storage,
manipulation, display and analysis of spatial environmental data.
It is a data integration tool which combines sophisticated
mapping capabilities with a large computing capacity-
It enables extensive multi-media analysis and evaluation in
geographic areas which were previously too time consuming or
difficult to investigate.
257
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In 1988, the Region obtained the GIS, as well as ARC/INFO
software, PRIME computer expansion, a digitizer, plotter and
other mapping accessories. The project team staff time, coupled
with increased PRIME computer use, represent a considerable
investment of resources. This pilot project in Ground Water
Protection applications was undertaken to explore the full use of
this tool in the Region.
The Regional CIS pilot project had these objectives:
* Develop a management tool which would help the Region more
effectively and efficiently address ground water problems
and protect underground sources of drinking water
* Develop Regional expertise and procedures for the use of
GIS software and hardware
* Demonstrate several applications of this technology which
yield tangible results to Regional managers
* Provide recommendations to managers regarding GIS uses
to assist in determining environmental and program
priorities, and directing compliance monitoring and
enforcement efforts of the Region.
Project Description
The project sought to demonstrate an application on a
county-level scale. New Castle County (NCC), Delaware was
selected as the study site:
* It is one of the most vulnerable and ground water dependent
counties in the Region
* Large amounts of digitized data were readily available
for use through a cooperative arrangement with the USGS and
NCC Water Resources Authority (NCC WRA)
* The County has an ongoing interest in implementing wellhead
protection measures.
Initially, the project goals were broadly defined: to
identify public water supplies and potential contamination
sources; to study areas that were susceptible to contamination;
to evaluate risks to ground water; to delineate wellhead
protection areas, and to target areas for priority regulatory
attention.
The initial project was to implement the data collection,
conversion and evaluation. The NCC WRA had an abundance of
digitized information available, but was on a different GIS,
called AERI. The USGS also provided data which was already
digitized in ARC/INFO format. In order for the AERI data to be
258
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scanned, the data was first converted to ARC/INFO format. Once
converted, the data was examined and the necessary information
was extracted for this project. Test plots of facility site
locations were constructed and compared to source maps to
evaluate the quality of the data. Upon completed, these map
coverages were constructed:
* Locations of EPA regulated facilities; including NPDES major
discharges, CERCLA sites, and RCRA facilities
* Location of high risk (ie., older than 15 years) underground
storage tanks (USTs)
* Location of public water supply (PWS) wells
* Location of PWS surface water intakes
* County/subcounty DRASTIC evaluation
* Population density
* Land use applications
* Septic tank suitability evaluation
* Recharge areas
* Aquifers
* Slope
* Soils
* Geology
* Hydrology
Figures 1 and 2 illustrate the methodology and construction
of the map coverages, locating the potential sources of
contamination relative to the public water supply wells, ground
water recharge areas and wellhead protection areas. Site data
for a specific facility can be retrieved from the INFO file (of
ARC/INFO) and displayed as illustrated on Figure 1. Other data
files were constructed (not shown) that contain such information
as: PWSs using ground water that are in violation of maximum
contaminant levels (MCLs), population dependency on ground water,
reported incidents of contamination and status of remediation.
The next aspect of the project was to identify areas that
were vulnerable to contamination. The "DRASTIC" methodology,
developed by the National Well Water Association (NWWA) and EPA,
was used to evaluate ground water pollution potential to assess
the county's vulnerability to ground water contamination (refer
to Figure 3). DRASTIC is an acronym representing the most
259
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-------
LOCATION OF POTENTIAL SOURCES OF CONTAMINATION
RELATIVE TO GROUND WATER RECHARGE AREAS/WELLHEAD PROTECTION AREAS
NEW CASTLE COUNTY, DELAWARE
IIUMD
HICH-FIIOtm
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^ »IUHIA6 PIOIICIIOII AHA
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FIGURE 2
261
-------
POTENTIAL VULNERABILITY BASED ON DRASTIC INDEX
UCDffl
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P IBS 1HM01
g DM2D
g BI-UO
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FIGURE 3
262
-------
important factors controlling ground water pollution potential,
including: Depth to ground water, net Recharge, Aquifer media,
Soil media, Topography, Impact to the vadose zone, and hydraulic
Conductivity of the aquifer. DRASTIC ratings, assigned by the
NWWA to 5.5 acre grid cells, were aggregated and categorized to
reflect the county's total vulnerability range (less than 101 -
greater than 180). The higher the DRASTIC score, the greater the
vulnerability to contamination.
To delineate Wellhead Protection Area (WHPA) boundaries
around PWS wells, the arbitrary fixed radius method was employed.
A two-mile radius was selected to minimize underprotection
resulting from not directly incorporating processes of ground
water flow. In the map on Figure 4, WHPA's and Recharge Areas
containing highly vulnerable hydrogeologic settings - where
DRASTIC scores exceed 160 - were identified for further analysis.
These areas were evaluated relative to each other by this
equation:
RATING = 2 (MCL VIOLATIONS) * 2 (RCRA RELEASES)
* 2 (USTs 15 YEARS OR OLDER) * # of CERCLA
SITES * 2 (RCRA SITES) * 3 (USTs)
The equation incorporates a range of risk-related factors
including potential sources and known incidents of contamination.
The map on Figure 5 shows the ten areas of highest risk for
ground water contamination. Their characteristics are summarized
in Table 1.
Based on this evaluation, the Wellhead Protection Area in
the city of New Castle appeared to be undergoing the highest
degree of environmental stress. It is this area that would
receive the highest priority of EPA compliance monitoring and
enforcement.
Project Results
The CIS project for ground water protection resulted in
both tangible and intangible benefits to the Region and the NCC
WRA. The following are tangible results:
* A true Federal/local partnership was developed to work towards
a common goal - with no money other than in-kind services from
both parties
* The development of a management tool to assist managers in
determining environmental and program priorities
* Delaware and New Castle County were assisted in the development
and implementation of their Wellhead Protection Programs
* EPA provided a technical assistance vehicle for states/locals
in a program where Federal resources are limited
263
-------
WELLHEAD PROTECTION AREAS AND RECHARGE AREAS
CONTAINING HIGHLY VULNERABLE HYDROGEOLOGIC SETTINGS
SC*Lt
nusncMH
f IBS 1HUDI
g BI-BJ
g Bl-ttO
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Q CIOIM VAin HOUSa WOUCIBd AIU
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FIGURE 4
264
-------
TARGETING OF HIGH RISK GROUND WATER AREAS
UIHICIOlUt SIOItGC UIKS
HUN DISK
UltCltlOUID HOIAtt Ul(]
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FIGURE 5
265
-------
TEN GEOGRAPHIC AREAS AT HIGHEST RISK FOR
GROUND WATER CONTAMINATION
WELLHEAD PROTECTION AREAS
AREA 1
RATING 119
25 PWS WELLS
26 USTs
16 HIGH RISK USTs
9 CERCLA SITES
POPULATION SERVED-5,500
AREA 2
RATING 113
15 PWS WELLS
20 USTs
19 HIGH RISK USTs
13 CERCLA SITES
POPULATION SERVED-30,000
RECHARGE PROTECTION AREAS
AREA 1
RATING 59
12 PWS WELLS
13 USTs
7 HIGH RISK USTs
6 CERCLA SITES
POPULATION SERVED-5,500
AREA 2
RATING 34
1 PWS WELL
2 CERCLA SITES
1 RCRA FACILITY
14 RCRA RELEASES
1 MCL VIOLATION
AREA 3
RATING 36
2 PWS WELLS
2 HIGH RISK USTs
2 CERCLA SITES
1 RCRA FACILITY
14 RCRA RELEASES
AREA 3
RATING 21
4 PWS WELLS
5 USTs
3 HIGH RISK USTs
AREA 4
RATING 26
6 USTs
5 HIGH RISK USTs
2 CERCLA SITES
AREA 4
RATING 15
3 USTs
3 HIGH RISK USTs
AREA 5
RATING 26
8 USTs
1 HIGH RISK UST
AREA 5
RATING 12
4 PWS WELLS
2 CERCLA SITES
5 HIGH RISK USTs
TABLE 1
266
-------
* The Region's understanding and assessment of the scope and
nature of environmental problems was dramatically improved
* GIS techniques proved useful to others in the Region and
states.
Future Directions
Based upon successful experience with the GIS project,
the Region committed program resources for a number of GIS
projects. For the Ground Water Protection Program, the
identification of Regional ground water sensitive areas will be
initiated to oversee and direct EPA-funded activities in states
under the Clean Water Act (CWA). Further, a detailed analysis
(on a larger scale) will be implemented for those counties
undergoing environmental stress, due to the number of
contamination sources and higher degree of ground water
vulnerability.
Also proposed are a number of Federal/state/local
cooperative initiatives to use the GIS technology and Regional
expertise to further their ground water protection programs:
* Delaware: To assist in data sharing on pollution site locations
and WHPP assistance.
* Pennsylvania: To identify ground water areas most vulnerable to
contamination, and to assist with their WHPP development.
* West Virginia: To assist the Department of Natural Resources
and the Department of Health promote WHPP development and the
tracking of ground water trends.
* Jefferson County, West Virginia: Begin joint GIS initiative to
facilitate a pesticides management plan.
* Anne Arundel County, Maryland: To explore joint GIS approaches
and WHPP development.
* Carroll County, Maryland: Begin joint GIS initiative to
facilitate WHPP development.
* Lancaster County, Pennsylvania: Begin joint GIS initiative to
facilitate a pesticides management plan.
26T
-------
Ac knowledgements
The author wishes to acknowledge the assistance provided by
the following people at EPA, Region III: Jon Capacasa, Chief of
the Drinking Water/Ground Water Protection Branch, Dr. Ava Nelson
Zandi of the Ground Water Protection Section, and David West of
the Information Resources Management Branch.
268
-------
Biographical Sketch
Stuart Kerzner, Chief
Ground Water Protection Section
Water Management Division
U.S. EPA, Region III
841 Chestnut Building
Philadelphia, Pa. 19107
I am a 1972 graduate of Ohio State University with a B.S. in
Geology, and have completed graduate work in Water Resources
Engineering. I have spent the last 16 years working in the
related fields of environmental engineering and hydrogeology- My
initial involvement was with the New Jersey Department of
Environmental Protection, Division of Water Resources, where I
worked as a ground water geologist and later as an environmental
engineer.
Since 1976, I have been working on the federal level for
EPA, Region III. I have been involved in virtually all existing
surface and ground water related programs. In 1983, I became
involved in the ground water protection program. As a member of
the Ground Water Task Force, I helped develop the Agency's
National Ground Water Protection Strategy in 1984.
Currently, my position is Chief of the Ground Water
Protection Section, which is primarily responsible for the
coordination of all ground water-related programs in the Regional
Office. I oversee the State Ground Water Protection Strategy
Program, the Regional Geographic Information System (GIS) Ground
Water Program, and the Wellhead Protection Program.
269
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270
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A COMPUTERIZED DATA MANAGEMENT SYSTEM FOR WELLFIELD PROTECTION
Thomas F- Jenkins and Guy Jamesson
Malcolm Pirnie, Inc.
6161 Busch Boulevard
Columbus, Ohio 43229
Abstract
The City of Columbus, Ohio operates a municipal wellfield capable
of producing approximately 30 million gallons per day (mgd). Water is
withdrawn from a glacial aquifer by four collector wells adjacent to
the Scioto and Big Walnut rivers. The wellfield land area is presently
subjected to pressures of urban housing, commercial and industrial
development, sand and gravel mining, and highways frequented by
hazardous material cargoes.
The pressures of development and the resulting pollution sources
in the area have created potential for wellfield contamination. The
"Wellfield Protection and Management Plan" prepared by Malcolm Pirnie,
Inc. for the City in July, 1988 proposed creation of a comprehensive
ground water monitoring network covering a two-mile radius around the
wellfield. The monitoring network is expected to generate a large amount
of data regarding the water quality and flow characteristics of the
surface and ground water.
Malcolm Pirnie, Inc. developed for the City of Columbus an easy to
use computerized database management system to effectively manage this
large database. This paper will describe the major components of this
system. The system can store and retrieve data, prepare reports and
create graphics. The graphics program can compare the collector well
discharge to the water quality parameters over the time span of the
data. Having established the background water quality, the database
system can readily show any changes in water quality. In addition, the
water quality data can be exported to a spreadsheet or other programs,
to develop Piper water quality diagrams or perform other more complex
forms of analysis.
The database system generates graphic data presentations as
information is collected. This allows the City to make quick, reasoned
and appropriate decisions regarding wellfield protection.
COSWF.R/tdg
0228-48-1143 271
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Introduction
Any successful wellfield protection program includes three major
phases. First, the aquifer and its relation to surface features is
studied and a suitable protection program is developed. This is the
foundation of the program, where the contamination-susceptible areas
are delineated and a plan of action is developed. Second, the program
is implemented by protecting the areas vital to the wellfield. This is
frequently the most difficult phase because it typically involves
controlling and often changing the land use within the wellfield.
Third, a monitoring system must be developed to detect potential adverse
impacts on water quality and quantity. If this last phase is omitted
or if the data collected is not analyzed, the long term wellfield
protection may be jeopardized.
This paper outlines a data management system which was developed
for the City of Columbus, Ohio, as part of a complete wellfield
protection program.
Background
The City of Columbus operates a 30 mgd wellfield south of the City
referred to as the South Wellfield (Figure 1) . The situation in
Columbus is somewhat unusual, because although the wellfield draws water
from an area of approximately 9 square miles, the City controls only a
very small portion of the land.
The Columbus South Wellfield obtains water from a glacial outwash
valley fill aquifer deposited in a pre-glacial valley. Water is
withdrawn from four collector wells, three located along the Scioto
River and one located along Big Walnut Creek as shown on Figure 1. The
water withdrawn represents a mixture of approximately 87 percent ground
water and 13 percent stream water induced by pumping (Sedam, 1988).
Figure 2 shows three geologic cross sections drawn through the
wellfield. In general, the glacial outwash deposits can be subdivided
into lower and upper sand and gravel units separated by a clay till
which thins toward the center of the valley. Where the clay till is
absent, the upper and lower outwash units coalesce. In some areas of
the wellfield, outwash deposits are separated from the bedrock by
another clay till layer deposited directly on bedrock.
Underlying the glacial valley fill is the Devonian age Ohio shale
and Columbus limestone. The Silurian age Bass Islands dolomite
underlies the Columbus limestone. In the southern portions of the
wellfield, the Columbus limestone thins and may be absent (Schmidt,
1958). The shale-limestone contact bisects the wellfield with shale
underlying glacial deposits to the east and limestone underlying glacial
deposits to the west.
Under the natural ground water flow system in the South Wellfield,
recharge to the glacial outwash flows down the valley to the south with
a large percentage discharging to the Scioto River. This natural ground
water flow system has been locally affected by ground water withdrawal.
Figure 3 shows water levels in the glacial outwash aquifer measured July
COSWF.R/tdg
0228-48-1143 272
-------
1, 1986. Two prominent cones of depression have developed in the area
as a result of pumping. The first is associated with quarry dewatering
north of the wellfield, the second is associated with pumping from the
South Wellfield.
The potentiometric surface in the bedrock aquifer is dominated by
pumping from a private limestone quarrying firm. Most of the ground
water flow in the bedrock is in the limestone and dolomite carbonate
formations which are recharged in outcrop areas to the west. A per-
centage of the carbonate bedrock water discharges into the glacial
aquifer, the remainder flows downdip into a deeper bedrock flow system.
The degree of interconnection between the glacial outwash aquifer and
the carbonate bedrock aquifer is controlled by the presence or absence
of the clay till layer on the bedrock surface.
The water treatment facilities in the South Wellfield were designed
to handle a mixture of ground water and surface water drawn from the
glacial valley fill aquifer. Because of the high concentrations of
dissolved solids in the carbonate bedrock water an increase in the
percentage of water from the carbonate bedrock aquifer could affect the
treatment process. Several authors have evaluated the character of
ground water in the South Wellfield (de Roche, 1984, Schmidt, 1958).
Schmidt (1958) obtained an average hardness of 386 ppm total hardness
from 6 well samples in the glacial aquifer as compared to an average of
1129 ppm total hardness from 11 samples from wells in the Columbus
limestone and Bass Islands dolomite. Ground water from the Bass Islands
dolomite is particularly high in hardness and total dissolved solids,
and is very difficult to treat.
Factors Potentially Affecting the Wellfield
The south side of the City of Columbus is principally an industrial
area, with several manufacturing facilities, landfills, and quarrys. The
landfills are having an effect on ground water quality (deRoche, 1985)
however, they are located near the large limestone quarry located to
the north of the wellfield (Figure 1) . Presently, the large cone of
depression created by quarry dewatering intercepts a large portion of
the ground water flow. If the quarry dewatering were to cease, and the
wellfield was expanded, the possibility exists that landfill affected
water would migrate towards the wellfield. In addition, within the zone
of contribution to the wellfield there is a jet fuel pipeline, two gas
stations, several residential developments and a racetrack. The water
quality of the Scioto river is affected by urban runoff and the
discharge of treated wastewater from the Jackson Pike sewage treatment
plant located upstream. Most of the land use in the South Wellfield is
currently agricultural, however because of the value of the sand and
gravel deposits in the area an increasing percentage of the area is
being mined. Therefore, there are several factors that could have an
adverse impact on the South Wellfield:
surface spills,
infiltration of contaminated river water,
quarry dewatering,
COSWF.R/tdg 273
0228-48-1143
-------
- sand and gravel mining,
- landfill leachate in ground water,
mixing of bedrock water,
droughts
man-made reductions in recharge.
In order to assess the impact of these factors, the City must monitor
precipitation, surface water quality and flow, and ground water quality
and flow. These factors may be subdivided into two categories: water
supply and water quality. The water supply factors that require
monitoring are:
effects of local quarry dewatering
- effects of riverbed siltation
effects of reduced precipitation
effects of sand and gravel mining
effects of wellfield discharge on local private water
supplies
The water quality factors that require monitoring are:
- the influx of bedrock water induced by pumping
the quality of stream water
the impact of surface land use
the impact of nearby landfills
In order to assess the impact of these factors, a wellfield
monitoring plan was designed. Figure 4 shows the location of the
proposed surface and ground water monitoring locations. Under the
proposed monitoring plan:
1. Surface water will be monitored for flow and water quality
within a two mile radius of the wellfield.
2. Ground water level will be monitored continuously at several
locations near the collector wells and semiannually within a
two mile radius.
3. Ground water quality will be monitored within a one mile radius
of the wellfield.
The monitoring program developed was designed to expand on the wellfield
monitoring already being conducted by the US Geologic Survey and the
Ohio EPA. To provide adequate protection, a large area must be moni-
tored; therefore, the volume of data generated is considerable.
Database Management System
For the amount of data generated, manual data reduction would be
neither efficient nor practical. Therefore, the City required an easy-
COSWF.R/tdg 274
0228-48-1143
-------
to-use data management system to quickly demonstrate changes in water
quality and/or quantity. Therefore, a customized application was
developed using the dBASE III PLUS1 database management software and its
programming language. dBASE III PLUS was chosen for the database system
because of its wide use and compatibility with other programs.
Figure 5 depicts the structure of the data base system developed.
All files are linked to a master data file a the site identification
number. The master data file contains information on the location, date
of installation and construction particulars of a particular monitoring
station. The program is operated by responding to a series of menu
driven prompts. Information can be easily input and retrieved via this
menu driven system, and output to printed reports or data files.
Even with a data base which allows easy retrieval of data, the vast
amount of data available makes meaningful interpretation very difficult.
To help solve this problem, a graphics capability was developed within
the database system using the DGE2 program. A user-specified time period
of for any of the database parameters can be graphed by entering the
starting date. The mean, standard deviation and best-fit lines can be
displayed as an option. An example of a yearly graph of chloride
concentration in a collector well is shown in Figure 6. Another option
available is a time series graph. This graph displays the entire data
set on a particular parameter by moving the data horizontally across the
screen, similar to an oscilloscope.
Single parameter graphs are useful for identifying changes from the
historical background, but do not provide much information regarding the
possible causes of changes in background. In order to provide a method
to evaluate changes in background information, several graph types
showing various data comparisons were developed for the database system.
Presently,- the three following graph types can be generated:
- Collector well discharge versus monitoring well water
level and precipitation,
Collector well discharge versus collector well water
quality parameters,
- Stream discharge versus stream water quality.
Examples of each of these graphs are shown on Figures 7 through 9.
As the database system is used and enhanced, additional comparison
graphs will be developed. Figure 7 shows the comparison of water levels
in a monitoring well near collector well 101, the combined collector
well discharge, and the stream discharge measured upstream of the
wellfield. The relation between pumping rate and water level for this
monitoring well is not clearly evident because it is in a location that
1 dBASE III PLUS is a trademark of Ashton-Tate Corpora-
tion
2 DGE is a registered trademark of Pinnacle Publishing
Inc.
COSWF.R/tdg 275
0228-48-1143
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occasionally floods. As the wellfield monitoring system is developed,
additional continuous water levels recorders will be installed to
provide a better picture of the relation between collector well
discharge and water levels in the area.
Figure 8 shows changes in concentrations of hardness, calcium and
alkalinity when collector well number 103 (CW-103) is pumped at a higher
discharge rate of 5.6 mgd. These changes are presumably related to an
increased influx of bedrock water, from either the Columbus limestone
or the Bass Islands dolomite. To date, the other collector wells in the
wellfield have not shown the same increase in these parameters. Because
CW-103 contributes only 18% of the water pumped, the treatment process
has not been affected by the water quality changes observed. Figure 9
shows the same concentrations in CW-101 when pumped at a higher
discharge rate of 7.2 mgd. There is no apparent increase in these
chemical parameters associated with the higher discharge rate in CW-101.
Apparently, in the vicinity of CW-103, there is a better connection
between the bedrock aquifer and the glacial aquifer.
Figure 10 shows the stream discharge in the Scioto River and the
5-day Biochemical Oxygen Demand (BOD5) and Dissolved Oxygen (DO) con-
centrations. This graph shows a good correlation between low DO and
low stream flow. This is probably because there is a sewage treatment
plant upstream of the wellfield and at low flow a large percentage of
the streamflow is treated waste water.
In addition to the above comparisons, water quality data can be
exported to a Lotus 1-2-3 file and graphed in Piper or Stiff diagrams.
A program developed by Cheng (1988) can be used to develop Piper
diagrams. Additional graphs could be developed to compare quarry
dewatering discharge, wellfield discharge, to monitoring well water
levels, combined raw water chemical character to total wellfield
discharge and collector well pumping level to collector well discharge.
Data comparisons like these need to be evaluated frequently for any
wellfield to identify problems in the early stages of development.
Summary
All too often, data on wellfield parameters is collected but not
evaluated for trends or changes in background until a problem has been
developing for some time. The database system developed allows the City
of Columbus plant operators to evaluate wellfield data as soon as it is
collected.
Conducting a wellfield protection study and implementing the
wellfield protection plan is the first step in safeguarding municipal
groundwater supplies. However, a comprehensive monitoring plan and an
easy to use data management system are necessary to provide early
detection factors having an of adverse impact on water quality or
quantity.
Acknowledgements
We appreciate the assistance provided by Bill Eitel, Mike Brown and
the staff of the Parsons Avenue Water Plant in conducting this study-
COSWF.R/tdg 276
0228-48-1143
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References
Cheng, S. 1988, Trilinear Diagram Revisited: Application, Limitation,
and an Electronic Spreadsheet Program, Groundwater, v.26, no. 4, pp.
505-510
de Roche, J.T., and Razem, A.C. 1984, Water Quality of a Stream Aquifer
System, Southern Franklin County, Ohio, U.S. Geological Survey,
Columbus, Water Resources Investigation Report 84-4238, 29 pp.
de Roche, J.T., 1985, Hydrogeology and Effects of Landfills on Ground-
Water Quality, Southern Franklin County, Ohio, U.S. Geological Survey,
Columbus, Water Resources Investigation Report 85-4222, 58 pp.
Schmidt, J.J., and Goldthwait, R.P., 1958, The Ground-Water Resources
of Franklin County, Ohio, Ohio Department of Natural Resources, Division
of Water, Columbus, Bulletin 30, 97 pp.
Sedam, A.C., Eberts, S.M., and Bair, E.S., 1988, Ground-Water Levels,
Water Quality, and Potential Effects of Toxic-Substance Spills or
Cessation of Quarry Dewatering Near a Municipal Ground-Water Supply,
Southern Franklin County, Ohio. U.S. Geological Survey, Columbus, Water
Resources Investigation Report 88-4138, 111 pp.
COSWF.R/tdg
0228-48-1143 277
-------
LEGEND
COLLECTOR *«LL
LIMESTONE QLMWW
LANDFILL
PARSONS AVE.
WATER PLANT
APPROXIMATE ZONE OF
CONTRIBUTION TO WELLFIELD
LOCATION MAP
COLUMBUS SOUTH WELLFIELD
FIGURE 1
278
-------
LEGEND
Cd CLAY
SAND
CHI SAND & GRAVEL
SHALE
LIMESTONE
LOCATION OF CROSS SECTION
0 2000 4000 6000 8000
' ' ' ' '
HORIZONTAL SCALE
50 100 150 200
I I I 'I
VERTICAL SCALE
GEOLOGIC CROSS SECTIONS
279
FIGURE 2
-------
PARSONS AVE
WATER
PLANT
M.
LEGEND
A COLLECTOR WELL
• WELL
— 690— POTENTIOMETRIC LINE
POTENTIOMETRIC LINE,
APPROXIMATE EXTRAPOLATION
PAVED ROAD
GROUND-WATER FLOW PATH
GROUND-WATER DEPRESSION
GROUND WATER LEVEL MAP
JULY 1, 1986
280
QUADRANGLE LOCATION
0 2000 4000 6000 8000
SCALE
CONTOUR INTERVAL = 10 FEET
FIGURE 3
-------
LEGEND
SEMIANNUAL STATIC WATER-LEVEL
O EXISTING
SEMIANNUAL WATER QUALITY AND STATIC WATER-LEVEL
• EXISTING
+ PROPOSED DRILLING LOCATION
CONTINUOUS WATER-LEVEL RECORDER
A EXISTING LOCATION, PROPOSED WATER-LEVEL RECORDER
m AND SEMIANNUAL WATER QUALITY MONITORING
SURFACE WATER SAMPLING LOCATIONS
,0. EXISTING SURFACE-WATER AND SEDIMENTATION
W SAMPLING STATION (OEPA)
.A, PROPOSED SURFACE-WATER AND SEDIMENT
^ SAMPLING LOCATION
A
PROPOSED WATER-LEVEL RECORDER AND SEMIANNUAL
WATER QUALITY MONITORING
PROPOSED WATER-LEVEL RECORDER LOCATION
QUADRANGLE LOCATION
0 2000 4000 6000 8000
SCALE
CONTOUR INTERVAL = 10 FEET
PROPOSED MONITORING NETWORK
261
FIGURE 4
-------
SOUTH WELLFIELD
MASTER FILE
ro
CO
to
MONITORING STATION FILES
WATER
LEVEL
CONTINUOUS
WATER
LEVEL
GROUND
WATER
QUALITY
COLLECTOR
WELL DAILY
PUMPING
RATE
COLLECTOR
WELL
WATER
QUALITY
WELL
CONSTRUCTION
RAINFALL
DATA
STREAM
DISCHARGE
DATA
STREAM
WATER
QUALITY
DATA
DATABASE MANAGEMENT SYSTEM STRUCTURE
FIGURE 5
-------
CALCIUM CONCENTRATION IN CW-103 (mg/1)
From 03/O1/B8 to O2/S8/89
aoo -
IBO -
16O -
c
A 14O -
L
j 120-
U
M 10O -
O9/06/89
O3/01/8B
O5/3O/88 O8/28/8B
DATE
11/26/88
02/24/89
FIGURE 6
RAINFALL
10/O1/B4
12/3O/B4 O3/3O/8S O6/2S/BS
DATA COMPARISON GRAPH - COLUMBUS SWF
O9/26/8E
FIGURE 7
283
-------
ro
CO
n
n n
x x x
XX
i 1 1 1 r
~i r
WATER QUALITY COMPARISON GRAPH - COLUMBUS SWF
COLLECTOR WELL CW1O3 : 07/15/87 TO O7/14/89
FIGURE 8
-------
rO
CC'
HARD .
+ mg/1
CALCIUM 100 -
WATER QUALITY COMPARISON GRAPH - COLUMBUS SWF
COLLECTOR WELL CW1O1 : O7/15/87 TO O7/14/B9
FIGURE 9
-------
tvji
CO
20 -
IB-
BODS. 1B~
mg/1 14 -
12-
10-
D.O.
8-
O mg/1
8-
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2-
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DISCH'ioooo-
CFS 5000-
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FIGURE 10
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Ground Water Resource Based Mapping
Nashua Regional Planning Area
New Hampshire
David Delaney
Hydrologist
U.S. Environmental Protection Agency - Region I
J.F. Kennedy Federal Building (WGP 2113)
(617) 565-3615
INTRODUCTION
The EPA and New England environmental protection, water resource
planning and economic development agencies are becoming
increasingly aware that the collective consideration of water
resources, waste disposal and land use is critical to sound
environmental decision making. EPA, Region I is actively
involved in four principal ground water resource management
initiatives: wellhead protection area delineation and management;
sole source aquifer designation; ground water resource
classification; and, Geographic Information System technology
use.
The New England states and the EPA share a common goal to protect
valuable and highly vulnerable environmental resources. The EPA
is working to improve ground water resource protection by
continuing to develop and use Geographic Information Systems.
Geographic Information Systems (GIS) can facilitate use of
environmental resource data to support in Federal and State
environmental program decisions and work products. Use of Region
I GIS is helping EPA better identify environmental problems and
to assess their nature and importance. Environmental program
management can be enhanced by using GIS to develop more
comprehensive technical bases for regulatory decisions.
EPA encourages proactive environmental protection. Resource
information displayed through GIS is improving our ability to
focus regulatory activity to protect critical resources.
Further, successful integration of EPA data bases with GIS can
improve use of limited staff and contractor resources. Staff
evaluating permits, conducting compliance monitoring and site
inspections and pursuing enforcement can be assigned to
regulatory activities impacting priority resources that are most
at risk. EPA program use of GIS can increase the consistency and
success of EPA environmental decisions resulting in more
efficient water resource planning and protection. GIS link of
EPA data bases will increase our ability to better respond to
EPA, State and Local need for data and technical assistance to
support ground water resource protection and management programs.
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PURPOSE
The often close proximity of contaminant sources to potable water
resources place human health at risk. The purpose of this
mapping initiative is to use CIS to depict ground water resources
in two New England pilot study areas and to show the geographic
relationship between these resources and potential contamination
sources. Maps and information compiled will be used to support
the following Office of Ground Water Protection goals to:
improve EPA and State capability to identify, environmental
problems and to assess their nature and importance,
support state development and implementation of wellhead
protection programs,
promote inter- and intra- agency program coordination of
resource protection efforts, and
demonstrate use of resource mapping to support prioritiz-
ation of EPA program activities.
SCOPE
There are extensive hydrologic, environmental and geographic data
base for New England. The EPA, Region I, Ground Water Management
Section has compiled these types of information to support the
Branch River Basin, Rhode Island, and the Nashua Regional
Planning Area, New Hampshire, mapping initiatives. These pilot
mapping demonstration areas were selected because GIS compatible
digital US Geological Survey maps describing the availability of
ground water in stratified drift aquifers and digital line graph
data are available.
Most of the people living within the pilot areas drink ground
water, a resource that is susceptible to contamination by many
land use activities. Release of contaminants associated with
some land use activities can degrade water resources and other
important environments. A major goal of this initiative is to
show the close geographic relationship between resources and
potential contaminant sources. These pilot areas were chosen
partly because there are a manageable number and a good spectrum
of Federal and State regulated facilities that can contribute to
environmental contamination. State and Federal efforts to
identify contamination sources and critical environmental
resources in these pilot areas offer an opportunity to combine
our water resource protection efforts. These small scale
initiatives support development of a broader regional
understanding of surface and ground water resources as a
framework for addressing issues related to regional water
resource protection, water supply allocation and waste disposal.
2138
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Ground Water Resource Based Mapping
Nashua Regional Planning Area
New Hampshire
NASHUA REGIONAL PLANNING AREA
NEW HAMPSHIRE
EPA initiated a ground water resource-based mapping pilot project
in New Hampshire to provide assistance with ground water protec-
tion. Discussion with the New Hampshire Department of Environ-
mental Services (NH DES) resulted in selection of the Nashua
Regional Planning Area pilot study area. The Groundwater
Protection Bureau of NH DES is actively inventorying Underground
Injection-Class V wells, solid waste dumps, contaminant releases,
wastewater discharges and underground storage tanks and delineating
wellhead protection areas and water resources in support of
groundwater protection within the Nashua Regional Planning Area.
NH DES indicated that they have access to the University of New
Hampshire Geographic Information System (CIS) that will provide the
state with capability to use CIS products.
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The Nashua Regional Planning Area is located in south central New
Hampshire. The area includes the towns of Amherst, Brookline,
Hollis, Hudson, Litchfield, Lyndeborough, Merrimack, Milford, Mont
Vernon, Nashua, Pelham and Wilton, Hillborough County- This 322
square mile area was chosen because of its manageable size and
because the project area is close to Region I, Boston, minimizing
travel and facilitating field work.
There are a number of Federal and State data management systems
containing information describing the Planning Area hydrology,
water resources, water supply, potential contamination sources,
and geography. Approximately 160,000 people live in this rapidly
growing part of southern New Hampshire. Drinking water is provided
primarily by public water supply and private wells. The project
area has cultural and hydrologic characteristics common to rural
New England. Within the project area there are approximately:
198 wells providing public water supply (68 community
wells and 130 noncommunity wells),
5 community surface water supply intakes,
41 national pollutant discharge elimination system
permitted outfalls,
7 national priority listed CERCLA sites,
43 non national priority listed CERCLA sites,
20 facilities reporting as per SARA Title III
regulations,
186 Resource Conservation and Recovery Act regulated
facilities (Nashua Facilities not inventoried), and
110 agricultural chemical application sites
Maps and information compiled can be used to support proactive
environmental protection. Resource and contaminant source
information displayed through CIS can improve our ability to focus
regulatory activity to protect critical resources.
The CIS data bases developed allow identification and delineation
of important Nashua area water resources and facilitate evaluation
of impact of potential contaminant sources near water supply
sources. This information helps provide a data intensive forum for
discussion of water resource and waste disposal management options.
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David Delaney, Hydrologist, U.S. Environmental Protection Agency,
Ground Water Management and Water Supply Branch, Region I, Boston.
Worked from 1967-1979 with U.S. Geological Survey, Water Resources
Division, New England District, conducting water resource
investigations in Massachusetts. Since 1979, worked with EPA as
a senior Water Management Division hydrologist providing program
technical support and conducting special projects associated with
water resource protection and management. Provided technical
support on Waste Management Division RCRA and Superfund enforcement
projects.
291
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292
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A MODEL COMMUNITY PROGRAM FOR PRIVATE WELLS
Roy F. Jeffrey and Karen K. Filchak
University of Connecticut
Cooperative Extension System
Storrs, Connecticut
Abstract
Successful implementation of a comprehensive municipal
groundwater protection program requires knowledgeable consumers.
The University of Connecticut Cooperative Extension System's
"model town" program was set up in order to bring individuals
into the groundwater protection process. Implemented in 1989,
the program provided groundwater information to residents of the
rural towns of Brooklyn and Pomfret so that they could properly
assist in the management of their private and public groundwater
supplies. A variety of delivery systems were used to transfer
drinking water supply information to individuals in the two
municipalities. A key part of the program was the formation of
community advisory groups which included the chief elected
official (first selectman), representatives of municipal agencies
and organizations as well as other interested persons.
The "model town" program methodology was designed to
supplement Connecticut's aggressive groundwater protection
program. The State's effort is targeted at the major aquifers
where most municipal and industrial supplies are located, but
does not directly address many of the more rural areas where over
one-sixth of the population derives its drinking water from
individual and smaller community wells.
Introduction
Protecting groundwater quality has become a major concern in
Connecticut during the 1980's. Because of this concern, the
State has begun an aggressive groundwater protection program.
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The program is multifaceted and is targeted to a wide variety of
audiences. A major focus of this program is the development and
implementation of protection measures in areas which overlay
major public water supply aquifers.
The University of Connecticut Cooperative Extension System
(UConn CES) is part of a unique national public education
organization that serves as a link between knowledge and its
useful application. In Connecticut, this means taking research-
based information to more than one-half million residents
annually.
The design and implementation of educational programs for
the protection of water quality is a major initiative of the
Extension System at both the national and state level. A state
Extension project team received United States Department of
Agriculture (USDA) funding to develop educational programs about
the importance of regular testing of rural water supplies, how to
interpret water test data and treatment methods to assure safe
drinking water. Thirteen Water Quality Fact Sheets were
developed to supplement this program.
As part of the USDA water quality grant, in March 1989 UConn
CES initiated a demonstration "model town" program in the
municipalities of Brooklyn and Pomfret.
The Setting
Connecticut has a population of 3.2 million people with over
32% deriving their drinking water from groundwater sources (Table
1).
Table 1. Groundwater Supply Statistics (Environment Committee, 1989)
(1985 Data)
Pop. % of Water % of all water drawn
Supply Source Served Pop. Withdrawn* from all sources
1400 Commun.
Supply Wells 518,190 16.2 65.6 MGD 16
250,000 Ind
Homes 514,990 16.1 38.6 MGD 10
TOTAL 1,033,180 32.3 104.2 MGD 26
*Million (s) gallons per day (MGD)
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Figure 1 Model Town Location Map
The two towns selected for the program, Brooklyn and
Pomfret, are in northeast Connecticut (Figure 1) and are served
entirely by groundwater sources. Although part of Brooklyn
overlies a public water supply aquifer, most persons residing in
the two municipalities rely on individual groundwater supply
wells (Table 2). Most of these individual wells are located in
areas outside the aquifer areas targeted for protection through
the State program.
Table 2. Water Supply Service Systems (State of Connecticut, 1986)
Brooklyn
Population on community wells
Population on individual wells
Total population
Pomfret
Population on community wells
Population on individual wells
Total population
2484
3346
5830
250
2500
2750
(43%)
(57%)
(100%)
(1%)
(99%)
(100%)
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Planning projections indicate these two communities will
face growth pressures during the next several years from the
Hartford, Providence and Worcester metropolitan areas. Most of
the growth in Brooklyn and Pomfret is expected to occur outside
any major public water supply aquifer area which may be targeted
by the State for protection. As a result, there will be an
increasing need for local government and citizen involvement to
protect water quality.
Why the Model Town Approach
The Connecticut Aquifer Protection Task Force was charged in
1987 by the State Legislature to examine means and methods to
protect the State's groundwater supplies. In their February 15,
1989 report to the legislature the Task Force indicated a need
for education to play a major role, (Environment Committee,
1989) .
"The Task Force feels the role of
education in protecting groundwater
cannot be overstated. As with many
environmental issues, a successful
program for protecting
Connecticut's drinking water
requires a change in the attitudes
of society based on enlightened
sensitivities to the finite
resources upon which it depends."
In order to implement a comprehensive local groundwater
protection program, it is important to educate citizens about the
topic so they may become willing and knowledgeable partners with
the governmental sector. A program of this sort differs from a
more traditional municipally-operated program such as
transportation planning and management which is usually initiated
and carried out almost exclusively at the governmental level.
The "model town" program was designed to bring the individual
into the process of groundwater protection by helping residents
understand how to manage their groundwater supplies as well as
learn how public and private actions can influence water quality.
It was hoped that, if successful in the "model community"
setting, the program could be used by other municipalities in the
State.
Brooklyn and Pomfret were selected because all the residents
in each community received their water from public and private
groundwater sources. In addition, each town had a chief elected
official (first selectman) who was interested and involved in
water quality issues.
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Implementation
A variety of delivery methods were used to transfer drinking
water supply information to the local residents. Approaches
included direct mailings, educational forums, activities with
community organizations, interaction with the media and one-to-
one consultations.
It should be noted that the issue of water quality is not
one in which one agency or organization has sole responsibility-
For this reason UConn CES recognized the need to network with
others interested in water quality and coordinated project
activities with the State Health Department, District Department
of Health and the local Council of Governments.
A key part of the program was the formation of an advisory
group in each community. Membership in the groups included the
chief elected official (first selectman), town commission members
and other interested persons. Individuals in each community were
identified and contacted by the first selectman.
Advisory group meetings were held to explain the project's
goals, present an overview of the town's water supply situation,
discuss possible role(s) of the advisory group, review available
Extension resources and consider means to disseminate
information. Advisory group members could become involved in
several ways:
1. Advisory - recommend methods or potential audiences
with which the Extension project team might work.
2. Coordinating - be involved in scheduling programs,
exhibits, etc.
3. Participation - be available to respond to certain
inquiries or assist in information dissemination (i.e.
distributing fact sheets, staffing exhibits, etc.)
The importance of the advisory groups should be emphasized.
These groups were able to bring local knowledge, guidance and
ideas to the Extension project team that might otherwise have
been overlooked. As a follow up to the meetings, advisory group
members were kept informed by a newsletter.
Activities
Program activities were conducted during the seven month
funding period which began in March 1989. These activities
included:
1. Special Mailing - Because Brooklyn and Pomfret have
relatively small populations (5830 and 2750 respectively), it was
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felt that a direct mailing to all residences would achieve
maximum exposure, while still being economically feasible. An
informational packet was mailed to 2356 residential units with
private wells. The packet contained a cover letter that
described the groundwater quality issues and outlined an
opportunity for residents to take advantage of a reduced rate
standard parameters water test. Also included were the fact
sheets "Testing the Private Well" and "Maintaining Your Septic
System" plus an order form for other Water Quality Fact Sheets.
Informational packets were also mailed to 260 residential
units on a public water supply. They received the same materials
except that the fact sheet "Testing the Private Well" was
replaced with "Customers on Public Supplies."
A follow-up packet with information on how to participate in
the reduced rate water testing was sent to all who inquired.
2. Educational Presentations - Brooklyn and Pomfret had a
limited number of groups to which formal educational
presentations could be made. However, targeted groups did
include local churches, school PTO's and horticultural societies.
3. National Drinking Water Week - This was a national
effort to increase public awareness of the drinking water supply.
The project team participated in this effort by distributing
information packets. One packet was distributed through a local
garden center in Brooklyn and contained information on water
quality and the home landscape. This packet included a cover
letter about National Drinking Water Week (NDWW), a NDWW sticker
and the Extension fact sheet "Well Water and the Home Landscape."
Another packet was distributed in conjunction with a well
drilling and treatment company's efforts to promote National
Drinking Water Week. This packet provided information about how
people with a private water supply could get a water test. The
packet included the same NDWW information but with the Extension
fact sheets "Testing the Private Well" and Nitraties."
4. Water Quality Quiz Board - A self-contained quiz board was
developed and offered at fairs and other public gatherings so
that participants could determine their knowledge of basic water
facts. The portable board was designed with a light-response
mechanism which indicated the correct answer. This board served
to facilitate discussions about water quality issues with
representatives of the project team.
5. Media - A variety of media outlets provided an important and
cost-effective opportunity for information dissemination.
An interview about the program was conducted on radio
station WINY in Putnam. Several public service announcements
(PSA's) about various aspects of the home water supply (water
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testing, septic system management, and the home landscape) were
developed and aired.
The two major newspapers in the two-town area carried
articles about the program. An article in the Norwich Bulletin
promoted the program and an article in the Patriot Observer
provided information on understanding the home water supply.
A one minute educational spot on residential water quality
was produced and aired on Connecticut Public Television (CPTV)
Channel 24. CPTV's viewing audience includes the model town
area.
6. School Programs - The project team initiated work with
Ragged Hill Woods, a non-profit environmental education program
in northeastern Connecticut, to provide water quality curriculum
to participating area schools. Extension water quality materials
were incorporated into the curriculum used in the Ragged Hill
Woods program.
7. Regional Council of Governments - A presentation by the
project team was made to the ten chief elected officials
represented on the Northeast Council of Governments. The
presentation provided an overview of the program. The potential
for similar programs region-wide was highlighted.
8. Agency Coordination - A key component of the program
was coordination with a variety of state, regional and local
organizations. Cooperative Extension, like most other agencies
which have a responsibility in the groundwater protection area,
is a relatively small organization with a state-wide delivery
system. For this reason it is extremely important for agencies
to work together to achieve common objectives. Close
coordination with representatives of the State Health Department,
Northeast Regional Health District, Northeast Council of
Governments and a non-profit environmental education program
enabled the project team to move forward with the program.
Evaluation
Since project activities ended in September, 1989, a formal
evaluation has not been completed. Requests for water testing
information and additional facts sheets, however, indicates a
strong level of interest in this area.
The evaluation instrument that will be administered to
residents of the model town area will determine the:
.Amount of information received
.Source of the information (mailings, media, etc.)
.Value and usefulness o'f the information
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.Readability of the fact sheets
.Any additional information sought or actions taken (i.e.
water tests) as a result of the model town program.
Summary and Conclusions
This program addressed the need for citizen education about
groundwater protection. The small population size of Brooklyn
and Pomfret presented limited opportunities for formal and
informal presentations but did provide an excellent opportunity
for the dissemination of information by direct mailings and
follow-up contacts. Involvement and support of the chief elected
officials was a critical factor to the success of the program.
Based on discussions with representatives of the Northeast
District Department of Health and the Council of Governments,
expansion and transferability of this sort of citizen education
program should include consideration of the following:
. Delivery methods should be expanded through workshops for
local and regional organizations which deal with topics in
this area and have direct contact with the public.
Organizations should include realtors, water testing
laboratories, health departments and local building
inspectors.
. Recognition that local and regional government leadership
should be prepared to respond to increased interest and
participation by citizens in protecting groundwater quality.
Implementation methods may vary in other geographic regions,
specific to those locations, such as population, sources of
drinking water and community involvement.
References
1. Department of Environmental Protection, 1986. Connecticut
Natural Resources Atlas Series: Community Water Systems in
Connecticut. State of Connecticut. Hartford, CT.
2. Environment Committee, 1989. Report of the Aquifer
Protection Task Force. State of Connecticut General
Assembly. Hartford, CT. 72 PP.
Biographical Sketches
Roy F. Jeffrey has been an Extension Educator with the
University of Connecticut Cooperative Extension System since
1980. He is responsible for working on a variety of
300
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environmental management programs at the municipal level,
including composting, groundwater protection and agricultural
land preservation.
Mr. Jeffrey received his BS and MS degrees in Plant and Soil
Sciences from the University of Maine. He has worked extensively
in environmental planning and has previously been a planner with
the City of Bangor, Maine, the Southwestern New Hampshire
Regional Planning Commission, and Prince George's County,
Maryland.
Mailing Address: Roy F. Jeffrey
University of Connecticut
Cooperative Extension System
562 New London Turnpike
Norwich, CT 06360
Karen Filchak has been an Extension Educator with the
University of Connecticut Cooperative Extension System since
1977.
Ms. Filchak has worked with a variety of audiences including
the general public, professional organizations, teachers,
agencies and the media. Among topics addressed in public service
announcements, interviews and articles with television, radio and
newspapers are residential water testing, household hazardous
wastes and septic system maintanance.
Ms. Filchak received her BS and MA degrees from the
University of Connecticut in Design and Resource Management and
Higher Technical and Adult Education, respectively. Additional
graduate studies in public health and water policy were completed
at the University of Massachusetts. She has also completed
Cornell University's course "Local Groundwater Management:
Aquifer Contamination Protection and Community Response."
Ms. Filchak has had statewide program responsibility for
residential water quality since 1985.
Mailing Address: Karen K. Filchak
University of Connecticut
Cooperative Extension System
139 Wolf Den Road
Brooklyn, CT 06234
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BOARDS OF HEALTH PROTECTION FOR PRIVATE WELLS AMD
Haroia Elizabeth. Benes
Executive Director
Massachusetts Association of Health. Boards
56 Taunton St Plainville^ Ma. 02762
Abstract
In Massachusetts, people depending- upon private
are unprotected against improper siting, poor installation
a.±id. eoxvfc.timd.xta.-fc.xoxi t except where1 local health boards have
adopted regulations. Effective private well protection
utterly depends upon the local board of health adopting a
veil protection policy which is consistent with local
needs and conditions. In addition to specific private well
regulations, there are other actions which local boards
oan take as part of an overall groundwater protection
program.
The following paper ± a brief summary of the local
initiatives available for the protection of private wells
and groundwater. For more detailed information, please
refer to the Board of Health Handbook for Private Well
Protection and the references cited therein. To obtain a
copy
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PRIVATE WELL PROTECTION
THE LEGAL AUTHORITY OF BOARDS OF HEALTH
Boards of health in Massachusetts are potentially the single
most effective agent for environmental protection, particularly .for
ground and surface waters. Mass. General Law Ch. Ill s. 31 grants
health hoards broad powers to prevent and abate threats to public
health. State Supreme court rulings have in recent years tended to
affirm and even expand the interpretation of these local powers. For
example, in United Reis Homes. Ino. v. Planning Board of Natick, 359
Mass. 621 (1971) the Court stated, "Boards of Health have plenary
power to make reasonable health regulations and to remove or prevent
nuisances, sources of filth and causes of sickness." In a more
recent case , Independence Park, Inc. v Board of Health of the Town
of Barnstable (S J C. No. 4817 August, 1988), the Supreme Court
ruled that, "If we did not defer to the board of health's conclusion
that an existing regulation mandating sewers in some circumstances
did not preclude an order to build sewers in different
circumstances, we would be forcing boards of health to be
omnisciently comprehensive in writing their regulations. That would
be an intolerable burden and an unattainable objective." In this
broad interpretation of the board of health's authority under MGL
Ch. 41 s.81U, the court recognized that it is impossible for health
boards to foresee and prevent through regulation every circumstance
which might lead to groundwater contamination. And while the board
cannot contradict its own regulations, neither is it limited to them
when it makes binding recommendations on subdivision plans.
Board of health regulations also take precedence over zoning. If
nitrate loading or private well regulations result in the necessity
for larger lot sizes than required under town zoning, the board of
health regulations must be met. It is important to note however,
that local health boards do not have statutory authority to regulate
growth, and therefore, the intent of the regulation must be the
protection of public health and the prevention of nuisances.
In theory, a board of health's regulatory authority is limited
only by its ability to track and measure the causes of groundwater
contamination. Whenever scientific evidence links environmental
and public health, boards of health have a unique ability to
extend their authority quickly and efficiently. As long as a
regulation is neither illegal, arbitrary, unreasonable nor
inconsistent with its stated purpose, there is a legal presumption
in favor of the regulation
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Urtfortunately.. only a small percentage of health boards
actually utilize their full authority. In some communities the
digging or drilling of private wells remains completely unregulated.
It is entirely legal in many parts of the state for a well to be
drilled within a few feet of a septic system.
A strong board of health that is committed to groundwater
protection can act much more efficiently than state or federal
government. To begin with, the local board and its agent should be
familiar with areas of critical environmental concern, such as
aquifers, wetlands and recharge areas. The board of health can also
adopt or amend regulations without going through a lengthy hearing
process. Board of health regulations take effect after they are
voted, published in the local paper and posted with the Town Clerk.
A copy should also be sent to Department of Environmental
Protection. This ability to move swiftly is necessary so that
health officials can act effectively to protect the public health.
If a developer or any other aggrieved party wishes to challenge the
board of health's action in court, the burden is on the complainant
to prove that the contested actions do not tend to protect the
public health.
Across the country, there is a growing recognition of the
economic value of private water supplies and the public health
necessity for protective regulation. It is now recognized that
regions which are served only by private water supplies should be
treated as environmentally sensitive For example . some underground
storage tank regulations and hazardous waste cleanup standards
provide the same level of protection to areas relying upon private
wells as to the zones of contribution to public wells
There are no comprehensive state regulations governing private
wells Although this may be partly due to political and economic
considerations, it would also be very difficult to administer
uniform standards governing private wells in Massachusetts. Natural
conditions vary considerably across the state and result in very
different problems and requirements. Local variables include
geology, groundwater flow arid other hydrologic factors . and land
use For example, in the stratified drift , sole source aquifer of
Cape Cod, regulators must protect relatively shallow wells which are
at risk from rapid transmission of pollutants through porous soils
and which are sited on comparatively small lots within a larger
setting of explosive growth patterns. At the other hydrogeological
extreme are deep drilled wells in bedrock, where yields may be
marginal, and the incidence of natural contaminants such as arsenic
or radon is occasionally high.
Local geology and soil conditions should be addressed in private
well regulations. These conditions include the characteristics of
the aquifer, the soil percolation rate, the depth of the well and
groundwater flow. Local land use patterns should also be considered.
For example, if the well sites are on or near agricultural land, it
may be necessary to test for pesticide contamination. If there are
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major sources o£ pollution, such, as auto junkyards or landfill*
there should be special setback and groundwater monitoring
requirements to map the migration. of any contamination plumes
Creating A. Local Private Veil Policy:
Seven Decisions Which. Define This Policy
1. Water quality standards must be defined.
2. Minimum distances for setback of wells from sources of
contamination must be established.
3. Will board of health regulation be extended to include
construction and quality control?
4. What well water tests will be required?
5. When will water testing be performed?
6. When and under what conditions will water
treatment systems allowed?
\
7 Will non-potable wells be permitted?
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Other Board CXf Health Actions Which Should Be Part 0£ An Overall
Groundwater Protection Strategy
1. Household & small generator hazardous waste pickups
2. Nitrate loading regulations
3. Underground storage tank registration & testing
4. Subdivision review (required under M&L Ch. 41&81U)
5. Public & Environmental Health Review Regulations
6. Registration oJE Private Wells Hear Utility Rights of Way
(333 CMR 11 04:(2)(c), 1986)
7. Banning septic system "cleaners"
\
8. Local pesticide use regulations
9. Local Emergency Response Planning Committees
(required under Federal Emergency Planning and Community Right to
Know Act o* 1986)
10. Toxic materials registration
11. Solid waste disposal regulations
12. Septic system siting and construction regulations
(heyond Title 5)
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Biographical Sketch
Marcia Benes
56 Taunton St..
Plainville, Ma. 02762
Ms. Benes is the Executive Director and past President of the
Massachusetts Association of Health Boards. She is also the founder
and Executive Director of MassCLEAH, a non-profit organization
dedicated to educating and networking local environmental advocates
She is the founder and President of the Natural Resources Trust, of
Plainville, Inc., which maintains the Benjamin Shepard Millt a
nature sanctuary and site of one of the oldest water-powered cotton
mills in the country. She has also served on her local Conservation
Commission and Board of Health.
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PRIVATE WELL PROTECTION IN SAND AND GRAVEL AQUIFERS
William B. Kerfoot
K-V Associates
281 Main Street
Falmouth, MA 02540
ABSTRACT
No state laws exist governing the sighting of private wells
relative to septic systems. Current state laws concentrating on
the sighting of septic systems relative to private wells are quite
limited. Three municipalities on Cape Cod (Falmouth, Mashpee, and
Wellfleet) have enacted public health bylaws to directly provide
for private well protection. The procedure Is currently applied to
proposed subdivisions and to private lot positioning of well and
septic systems In partially bullt-out subdivisions.
The need for private well protection was demonstrated from the
results of a survey of private well contamination In the Mares Pond
region of Falmouth, Massachusetts. The private well survey found
that 29 of our 44 wells had elevated Indications of contamination.
Impacted wells were being affected by plumes of wastewater leachate
from on-lot of neighbor Ing—1ot septic systems, a phenomenon termed
"short-circuiting" or "cross connecting". The source of contam-
ination was more often the next-door neighbors septic system than
the on-lot system. The frequency and Impact of "short-circuiting"
was related to ground water flow velocity (direction and rate) and
to recharge (local precipitation). The special Importance of the
Mares Pond residential well study was that It demonstrated that the
frequency of nitrogen contamination was related to orientation of
septic system and well within the groundwater flow field, not Just
simple distance of separation.
The private well protection procedure Is devised specifically
for unconflned (watertable) sand and gravel aquifers like Cape Cod
and southeastern Massachusetts Local watertables mapping direct
flow measurements and a small pump test are combined to obtain
information about the hydraulic conductivity of the local aquifer,
groundwater flow directions and velocities. Precipitation recharge
values are obtained from the USGS Water Resources Division. A
sensitivity analysis of the factors of velocity, recharge, and
anisotropy (vertical versus horizontal hydraulic conductivity) was
309
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conducted to evaluate the relative Impact on zones of contribution
of the private wells.
An elliptical approach is strongly recommended over circular
distances regions in which groundwater velocities exceed .5 ft/day.
A line is extended upgradient from the proposed position of the
well. The length of the upgradient line is determined by the local
groundwater flow velocity, anisotropy, field porosity, and recharge
rate. Tables of probable distances can be generated for differing
regions of coastal aquifers. A protective distance of 100 ft from
the line is provided as added protection for seasonal variation in
flow and recharge consistent with current circular (fixed distance)
approaches. Civil engineers are required to plot the protective
zones on plat maps of proposed subdivisions showing position of
septic systems, road catch basins, and fuel storage regions.
INTRODUCTION
Except for the limited municipal sewer systems in the towns of
Barnstable, Chatham and Falmouth, Cape Cod residents rely upon on-
site septic systems for wastewater disposal. Roughly 1/3 of all
residents obtain their drinking water from private on-lot wells.
While municipal regulations and the state environmental code for
location of on-site septic systems have emphasized placing the
septic leaching facility away from the private well, as of 1989
there are no comprehensive guidelines for private well construction
and protection. The purpose of this report is to review current
regulations for the sighting of private wells and to propose a
strategy for protecting private wells based upon the natural motion
of groundwater.
Existing Regulations
There are no state laws governing the sighting of private
wells relative to septic systems. Current state laws govern only
the sighting of septic systems relative to private wells and are
quite limited. They are inadequate to ensure protection of
drinking water sources from chemical pollution. The Massachusetts
Environmental Code (Title V; DEQE, 1977) is the primary law
governing septic systems. The code requires a four foot vertical
separation between the bottom of a septic leaching facility and the
maximum water table height, as well as a minimum 100-foot
horizontal distance between the leaching facility and drinking
water wells. The rationale for setting the horizontal separation
distance was based largely on the migration of indicator bacteria.
310
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The Contaminaiton Threat
The family of microorganisms known as coliform bacteria 1s a
common Indicator of pathogenic (I.e. disease-causing) pollution.
Coliform bacteria are attenuated (largely through natural die-off
and some filtration) as they move from a septic leaching facility
through the soil Into the groundwater and then with the groundwater
through an aquifer. The Massachusetts Department of Environmental
Protection (DEP) considers 100 feet a sufficient distance to remove
collforms In addition to bacteria, there may be viruses In domestic
wastewater that flow Into the household septic system from which
the leachate mixes with groundwater. Since tests for the presence
and concentration of bacteria are simple, while tests for viruses
are complex, mandated separation distancees between well and septic
system are generally based on bacterial indicators.
Two non-biological components of septic system effluent are
major threats to private wells: nitrate-nitrogen and organic
chemica1s.
The effluent from a typical household septic system with a
mean flow of 65 gal/day has an average nitrogen concentration of
over 30 ppm (CCPEDC, 1979). Typically this nitrogen reaches the
aquifer as nitrate-nitrogen (NO3 -N) In concentrations of more
than 10 ppm, NO3 -N is known to cause oxygen deficiency in infants
being breast or formula-fed. Physiologically, methemog1obin is
produced instead of normal hemoglobin, impairing the proper supply
of oxygen to the tissues. Increased methoglobin concentrations in
the blood stream have been shown on a physiological continuum down
to about two ppm in children in day nurseries exposed to elevated
nitrate-N in their Ingested water (Subbotin, 1961).
Even minute amounts of organic chemicals in drinking water
present serious health hazards. Such chemicals like solvents
(TCE,benzene) have been shown to cause many types of cancer
(especially cancers of the digestive system and liver), kidney
diseases, diseases of the nervous system, congenital malformations
and fetal deaths (Tardiff and Youngren, 1986).
It is all too easy to attribute pollution by organic chemicals
solely to commercia1/industria1 establishments-e.g., paint and
autobody shops, filling stations, printing enterprises, etc. Yet,
sinks 1n kitchens and bathrooms, toilet bowls and careless disposal
of substances in driveways should also be a major concern. Almost
every household on Cape Cod uses and discards several or all of the
following substances: household cleaning agents and degreasers;
oven cleansers; paint and paint thlnners (trupent1ne); septic
cleaners (acid-organic types); spray deodorants; and garden
herbicides and pesticides.
311
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Small capacity home wells are particularly susceptible to
organic chemical contamination. Whereas municipal wells derive
some protection from their large volumes of mixing and withdrawal,
private wells are not so protected. Domestic sewage has frequently
been found to contain trace amounts of petroleum distillates as
well as benzene, toluene, chlorinated hydrocarbons such as
trichloroethane, trichloroethylene, tetrachloroethylene,
dichlorobenzene and alkyl phenois.
It should be noted that unlike nitrogen and biological
pollutants, organic chemicals do not enter household sewage
continuously. Gasoline, paint thinners, solvents and even
pesticides are typically discharge only at irregular intervals.
Furthermore, once discharged into sewage, some proportion of these
chemicals is absorbed into soil particles or broken down by
bacterial action. That not-withstanding, some organic chemicals
are very persistent, and if a neighbor's septic system lies within
the recipient well's zone of contribution, a quantity of a
discharged chemical will probably enter that well and, as shown in
Table II, the volume of such chemicals sufficient to exceed
recommended concentraion levels in drinking water is very small.
TABLE I
Quantity of organic materials disposed through
a home septic system sufficient ot achieve critical
concentrations in drinking water lying within the
contribution zone of a well with 300 gallons per day
wi thdrawa 1 .
Concent rat i on
in product
Substance
Gasoline, unleaded
Benzane 1 . 0-2 . 1
Toluene 2.2-9.9
Xy1ene 0.7-3.4
Pest i ci des
Aldicarb 1.5-50
Chlordane varies
Sol vents
Trich1oroethy1ene 1-5
Recommended
maximum
concentration
in drinking
water (ppb)
5
2, 000
440
Quantity
to achieve
critical
1 eve!
50
10
1 pint
gallons
gallons
1/10 pints
less than
1/100 pint
1/10-1 pint (TCE)
1986 amendments to EPA Safe Drinking Water Act.
Does not include removal through treatment by the septic system or
adsorption/dispersion in sewage plume.
312
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The Mares Pond Study
In the summer of 1982, the Town of Falmouth, in cooperation
with the Barnstable County Public Health Department, conducted a
survey of private wells in the Mares Pond area. The survey
results indicated high levels of iron, ammonia and nitrate-nitrogen
in numerous wells. The Town health officials and local residents
expressed concern that a health hazard might be developing, hence
the Town undertook a special study of sources of private well
contimination (Kerfoot, 1987).
The results of the private well study were revealing. In the
region adjacent to Mares Pond, 29 out of 44 wells had elevated
MARES POND
IOO 200 FT
KEY
II HOUSE
• WELL
LEACHING FACILITY
SEPTIC PLUME SHOWING
SEASONAL SHIFT
PLUME INTERCEPTING WELL
Figure 1 The location of wells, septic systems
and septic plumes in a small section
of Mares Pond area.
313
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-indicators of contamination. The study showed that the
contaminated wells were being impacted by plumes of wastewater
leachate from on-lot or neighboring-lot septic systems, a
phenomenon termed "short-circuiting" or "cross-connecting." The
source of contamination was more often the next-door neighbor's
septic system than the on-lot system. Apparently more care was
exercised in positioning septic systems in relation to on-lot wells
than to neighbor ing-1ot wells. The Mares Pond area was developed
primarily in single family half-acre lots and exhibited a rapid
groundwater flow, ranging from one to five feet per day, in
sand/gravel soil conditions.
To demonstrate that the septic system plumes could be
contaminating the wells, the frequency of short-circuitings was
projected for the study region using a dispersion plume model
(Wilson and Miller, 1978). The observed frequency showed no
significant difference from the model's predicted occurrence of
short-circuitings . (See Figure 2.) The lengths of the projected
plumes ranged from 150 to 250 feet (using one ppm total nitrogen as
the edge of the plume). Three wells were found to have N03-N
concentrations from 14 to 27 pprn during a drought period from March
to June 1982. By 1983, when the rains increased groundwater
recharge, the nitrate levels dropped to below 10 ppm (the EPA-
recommended level for safe drinking water).
Large lot size did not guarantee adequate protection for the
private wells. One house studied was sighted on a lot larger than
one acre, but its well was nevertheless contaminated. The study
showed that the orientation of the septic systems relative to wells
and groundwater flow was the important factor in producing "short-
circuiting . "
The problems identified in the Mares Pond study are not
unprecedented A 1978 report prepared for the Health Department of
the Town of Barnstable showed a significant correlation between
nitrogen concentration at muunicipal water supply wells and the
expected nitrogen content based upon on-lot septic system and lawn
nitrogen loadings (KVAr 1978) The first detailed report devoted
entirely to private well-water quality on Cape Cod found that the
Barnstable County planning guideline of five ppm NCT-N was exceeded
at 273 wells and the U.S. Environmental Protection Agency drinking
water standard of 10 ppm was exceeded at 93 wells (Persky, 1986).
Figue 3(ibid.) shows the correlation between nitrate-nitrogen in
the private drinking water supply and the density of housing units
per acre. The special importance of the Mares Pond study is that
it demonstrated that the frequency of nitrogen contamination is not
just a simple matter of housing density, but also of the orienta-
tion of private wells and septic systems within the groundwater
f1ow field.
314
-------
UJ
II
li
I- U-
2 O
LU
O CE
2 UJ
O H-
Q -I
UJ _J
2 5
SLOPE = 0.752
INTERCEPT =0.351
CORRELATION COEFFICIENT = 0.802
HOUSING UNITS PER ACRE
Figure 2 Median nitrate concentration as a function of housing density
An Explanation Of Short-Circuiting
How does the short-circuiting of private wells and septic
systems occur? In general, groudwater moves through the aquifer
(the water-yielding subsurface soils) from higher elevation to
lower elevations. Note that the word "elevation" as used here
refers to elevations of the groundwater (or water table) not to
elevations of land.
Groundwater is quite mobile and flows continually beneath the
land surface. Figure 6 (Kerfoot, 1987) is a frequency diagram of
measured velocities of groundwater from over 100 locations in the
Town of Falmouth. With a velocity mean of 2.5 feet per day and a
mode of 1 2 feet per day, groundwater flow is a significant factor
that must be taken into account to protect wells from sources of
contamination. These flow rates have been confirmed by the United
315
-------
States Geological Survey (LeBlanc, et al., 1987). An independent
tracer study at a site in the northern end of Falmouth yielded a
mean velocity of 1.5 feet per day and maximum velocities as great
as three feet per day. As the velocity of flow increases,
FREQUENCY
— _ ro
3 en O ui o
i i i i i
13
13
17
9
10
14
7 ., .
6 >7
[A
0 0
"-11
01 23456 7
GROUNDWATER VELOCITY (FT/DAY)
Figure 3 Frequency distribution of groundwater flow rates in Falmouth, Massachusetts
constituents of a typical sewage plume can travel farther from the
source and the threat of contamination increases.
When a well is placed in the aquifer and pumped, thus
withdrawing groundwater, the configuration of the water table about
the well is modified. (See Figure 4) This modification is known
as a "cone of depression," and is accompanied by changes in
groundwater flow directions in the vicinity of the pumping well
(Driscoll, 1986). These rniodified conditions, coupled with the
natural (or static) groundwater conditions, dictate the area of
capture, or zone of contributionn (ZOC), to the well.
While the volume pumped is considerably smaller for a private
well than for a public supply well, pumping of a private well also
causes a depression in the nearby water table and influences
groundwater flow conditions. A methodology has been developed to
predict these flow conditions and subsequently to deliniate an area
of capture for the well (Kerfoot, 1985). This method is based on
316
-------
the determination of groundwater flow directions and velocities In
the vicinity of the well. The boundaries of the ZOC are then
extrapolated from this basic Information. Water table mapping in
combination with a small pump test, to obtain information about the
hydraulic conductivity of the local aquifer, can be used to
determine groundwater flow directions and velocities.
Based on a typical pumping rate for a private on-lot well
(approximately five gallons per minute for 60 minutes each day) and
typical groundwater flow velocities (approximately one to two feet
per day), a zone of contribution can be calculated that measures
over 150 to 200 feet in length and over 40 to 60 feet laterally,
This zone clearly exceeds the State Environmental Code's 100-foot
regulatory distance in the upgradient direction.
1 i
i i
i '
RAINFALL
I I
I I I i i i
\ t ORIGINAL WATER TABLE
WELL
0
1 I
i
z
2 -i
10 GW
I i
\ \ \ \ Jv CONE OF
" v \ \ \ DFPRF<
^ \\\
DEPRESSION
\
X
\
'ZONE OF
CONTRIBUTION
40
20
0
DISTANCE IN FEET
20
40
Figure 4 Cross-section through a cone of depression.(Adapted from Strahler, 1972)
When houses are built fairly close together on individual
lots, each of which contains a private well and septic system, the
possibility of short-circuiting between wells and septic systems
from nearby lots must be of concern.
317
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Delineating The Zones Of Contribution For Private Wells
To understand how private wells derive their water and how the
zone of contribution develops and is shaped, it is helpful to look
at three examples, starting with the simplest conditions and adding
complexities that better reflect actual hydrogeologic conditions.
An assumption common to the three examples is that the well's
pumping rate is 300 gallons/day.
Example 1: A well pumping in an area where there is no horizontal
groundwater flow:
In areas where there is no significant groundwater gradient
and thus no detectable horizontal groundwater flow, a well will
pull equally in all directions from the surrounding strata. The
immediately surrounding groundwater subsides symetrical1y, causing
a "drawdown" cone of depression around the well pipe. After the
pump is run for a brief period, the cone no longer deepens, but
reaches a steady state. At this time, the volume of groundwater
being withdrawn through the well is balanced by an equivalent
volume of recharge water. The displaced water volume moves outward
until it 1s balanced by the volume of infiltrating recharge. The
recharge area or ZOC of the well becomes a circle whose daily
recharge matches the daily withdrawal (i.e., 300 gallons/day) of
the wel1.
In this simple case, neither the well depth nor the well
screen configuration nor three-dimensional hydraulic conductivity
differences of the geological strata are significant variables.
The ZOC will be circular with an area sufficient to produce a
volume of recharge equal to the wel 1 's withdrawal, if the recharge
varies between 18 inches per year (.004 ft /square foot/day) and 24
inches per year (.0055 ft 3/square foot/day), the area of the
circular ZOC would be between 10,000 ft3 and 7,399 ft5 with a
radius between 56 and 48 feet. (Note-. A higher rate of groundwater
recharge results in a smaller ZOC for a well pumping at a constant
rate.)
The recharge values for a particular area can usually be
obtained from publications of the USGS Water Resources Division.
Generally, during summer the ZOC areas enlarge as withdrawal
Increases with lawn watering and recharge decreases with
evaporat ion.
It is worth repeating that the current Massachusetts sanitary
code (Title V) requires a 100-foot separation between an on-lot
septic leaching facility and a private well. For this example, the
Title V requirements add a protective zone of about 50 feet beyond
the normal recharge zone. If there were no horizontal groundwater
flow, this protective zone would be effective.
318
-------
Example 2:
A well pumping -in an area where groundwater flows
horizontally beneath the site at a rate of one foot/day
and in which the hydrogeologic conditions are
"isotropic" (i.e., water will flow into a pumping well
at an equal rate from both the vertical and horizontal
di rections):
-50
I I I
IOO ISO 200 250 300 350 400 FT
20
SIDE VIEW
TOP VIEW
-10 -
-5 -
0 -
5 L- STAGNATION
ZONE
REAR VIEW
V
ISOTROPIC
HORIZONTAL FLOW = I ft/d
WELL PUMPAGE = 40 f t3/d
VERTICAL RECHARGE = 22 3 in/yr
Figure 5 Computing the recharge zone (ZOC) by flow streamline analysis following
water particle movement
The conditions of Example 2 are common in the area midway
between the center of a groundwater lens and the shoreline when
there is a mixed medium sand substrate. A gentle gradient of
groundwater exists across the area in which the well is dug, often
about 0 3% (0.3 feet vertical drop across 100 feet lateral
distance) Two aspects have changed from Example 1. First, the
circular ZOC now begins to extend upgradient, becomes more
elliptical in shape, and develops a groundwater divide on its
downgradient side. Second, the shape becomes more sensitive to the
depth of penetration of the well screen into the aquifer.
Basically, there are two flow fields, one originally exist ng as a
constant regional flow from elevations of higher water eve! to
lower water level, and a second induced by water being withdrawn
from the well. These combine to form a unique flow field (Figure
5).
319
-------
Figures 5 and 6 show cross-sections of the flow fields. The
rainfall recharge Intercepted by the well now extends farther
upgradient than downgradlent. The pathway of the recharge moves
downward and Is pushed horizontally by the background flow and
pulled by the well withdrawal. With varying rates of recharge, the
boundary of the ZOC changes One can look at the dimensions of the
well withdrawal field by tracing the pathway of recharge water
particles (Figure 10). If the recharge Is 18 Inches/year and there
1s an effective porosity (I.e., void space between soil particles)
of 0.25 (25%) in the sandy substrate, the vertical movement of a
water particle 1s six feet/year downward, assuming a constant
groundwater gradient across the site. A three-foot long well
screen with a uniform withdrawal pattern would pull In water
recharged as far as 350 feet upgradient.
POROSITY'.25
Q = 300g/d or 40fl3/d
RECHARGE:
26in/yr
22.3 in/yr
18 in/yr
RECHARGE
50 100 150 200 250 300 350 FT
ZONE OF CONTRIBUTION
1fl/d
-10
-50 0 '50 IOO 150 200 250 300 350 FT
1-
UJ
UJ
--30
--20
[•-10
- 0
r«IO
••30
^ ZONE OF CONTRIBUTION ^
-------
hydrogeologlcal conditions; that 1s, with water flowing
Into tha well screen four times faster from the
horlzonal direction than from the vertical:
The most common condition observed on Cape Cod 1s represented
rLn^lJ1 u ^ ^^ C°d ^u1fer generally conducts water more
readily in a horizontal than a vertical direction This occurs
because the substrate was deposited In layers (stratified) during
the last glacial period. Commonly, the ratio of vertical to
conduct-iv^y varies from 1:3 to 1-10 (Guswa and LeBlanc,
_ If one substitutes a 1:4 vertical to horizontal conductivity
ratio for the Isotroplc conditions of Example 2 and computes the
flow changes, the ZOC flattens out substantially and shortens
This is because the physical arrangment of sand and sllty
alternating layers causes water to run Into the well more easily
laterally than vertlcallly. Since the vertical withdrawal
shortens, the distance of upgradlent withdrawal lessens. Given a
recharge rate of 18 Inches/year, the lateral distance across the
ZOC increases from about 40 to more than 80 feet and the length of
the ZOC Is shortened to about 125 feet. The area of the ZOC
remains constant at 10,000 ftz , balancing the dally mean
withdrawal. As before, recharge from rainwater falling Inside the
ZOC flows Into the well. Figure 7
The distance from the well to the upstream origin of Incoming
flow lengthens as the regional groundwater flow rate Increases.
VERTICAL VERSUS HORIZONTAL
HYDRAULIC CONDUCTIVITY
TOP
VIEW
PROTECTION ZONE
0 50 100 FT
RECHARGE RATE • 22 3 .n/yr
FIELD POROSITY . 25
FLOW RATE -I ft /d
SIDE
VIEWS
ISOTROPIC I/I
HETEROTROPIC 1/4
Figure 7 Variation in Anisotropy.
321
-------
A Simple Procedure For Private Well Protection
Using a short and simple procedure, health agents and
engineers can delineate an effective protective zone for typical
residential private wells. The procedure is based on the initial
determination of groundwater flow direction and velocity, using a
water table map and data on the hydraulic conductivity of the
regional aquifer and/or direct measurements using a groundwater
flow meter (Kerfoot, 1987).
First, the well is sighted. From that point a line is drawn
directly upgradient, i.e., the upgradient line. Its length is
dependent upon the recharge rate and velocity of the groundwater.
If the groundwater flow rate is zero, Its length is zero, and there
is essentially no upgradient line. Under these conditions, as
ZOC to the residential well is a
of about 53 feet. The Title V
region, out to 100 feet, and provide
(Figure 8) Where there 1s regional
be a significant upgradient line,
will Increase in length with increased flow velocities.
II can be used as a guide for the relationship between
outlined in Example 1, the
circular area with a radius
guidelines extend beyond this
an effective protection zone.
groundwater flow, there will
which
Table
groundwater flow velocity and the length of the upgradient line.
B. Flow = 1.0 «t/d
A. No flow
PROTECTIVE ZONE
Well
ZONE OF CONTRIBUTION
GROUNDWATER FLOW
UPGRADIENT
LINE
Figure 8 Protective Zones
A. Contrast between the fixed protective distance of the
current Title V regulations.
B. The proposed upgradient protective distances.
322
-------
Table II
The relationship between groundwater flow velocity
and the length of the upgradient 1-fne.
Groundwater Length of
Flow Upgradient Line
(ft/day) (ft)
0 0
-5 65
1-0 125
1.5 190
2-0 250
2-5 315
3.0 375
A three-foot well with a five-foot vertical zone of capture 1s
assumed. A hydraulic conductivity ratio (vertical to horizontal)
of 1:4 is assumed. A field porosity of .30 is used for the broad
sandy outwash plains. A mean annual recharge of 18 inches is
assumed. The upgradient line represents an upgradient extension of
the midpoint of the vertical intercepted flow withdrawal by the
well screen (Kerfoot, 1988).
An approximation of the length of the upgradient line can be
obtained from the following equation:
Length of Focal Line
F = 365 SnV
R
Where:
R = Recharge (ft/yr) = 1.5 ft/yr
n = Field porosity = .30
V = Transport Velocity = 1 ft/day
S = Depth of Influence of Screen = 5 ft
a = Vertical Hydraulic Conductivity = 1
b = Horizontal hydraulic conductivity - 4
F = 125 ft
The actual vertical withdrawal zone should be confirmed on
site with a small pump test and direct measurement of hydraulic
conductivity variation.
323
-------
As a final step, a 100-foot buffer zone is drawn about the
upgradient line and its two end points. For and area where there
is no groundwater gradient, the well protection zone would be the
same circle as that mandated by Title V, but for areas with more
usual hydrogeologic conditions the result of this procedure would
be an ellipse-like protective zone as shown in Figure 128.
The elliptical approach has four advantages:
1) It changes the protective zone into a shape which accounts
for the flow dynamics in an aquifer;
2) It is consistent with the concept of the Title V mandated
100-foot protective buffer zone between septic system and
we 1 1 ;
3) It provides additional protection against seasonal
groundwater fluctuations in the direction of groundwater
flow (up to 30-degree directional changes);
4) Its larger size compensates for increased withdrawal rates
and enlargement of the ZOC area during summertime periods
of low recharge.
Summary And Recommendations
There are no state laws or regulations for private well
construction and protection as there are for public water systems.
While the Massachusetts Environmental Code (Title V) requires a
septic system to be at least 100 feet from a drinking water well,
the regulation does not require that a new well be located 100 feet
from an existing septic system. Furthermore, Title V does not
consider local or regional groundwater flow conditions that may
make this distance inadequate to protect the private well from
biological and chemical contamination introduced into the
groundwater by the homeowner or his near neighbors. Adequate
protection can be assured by orientation of septic systems and
private wells, on-site and -on adjacent home lots, that considers
this essential factor. Models for delineating the zone of
contribution (ZOC) of groundwater to a private well are presented
in this report. They are based on typical hydrogeo1ogic conditions
for Cape Cod. Simple procedures are described that will enable
health agents and engineers to delineate an effective protective
zone for local residential wells.
As knowledge of both the characteristics of groundwater on the
Cape and potential health risks from contaminated private wells has
increased, it is essential to use this information to adopt better
approaches for preventing pollution problems.
324
-------
In the interest of the public health of all private well
users, the following recommendations are made:
1) The adoption of local health regulations which require that
well and septic system placement be based on groundwater
direction and rate of flow. Health regulations should also
include provisions for water quality testing of new wells
to determine existing sources of contamination.
2) Development of state regulations more stringent than Title
V for private well protection.
3) A county-wide education program to explain the health risks
involved in groundwater cross-contamination of wells by
septic systems.
4) Development by appropriate state and federal agencies of
procedures for identifying private well zones of
contribution in varying geological conditions for use by
professional civil engineers.
5) Support for more basic studies by the
define groundwater gradients, flow
hydraulic properties, recharge rates
dispersion characteristics.
USGS to further
characteristics ,
and chemical
ACKNOWLEDGEMENTS
The author would like to thank Scott Horsley for his comments
during formulation of the procedures and Victoria Lowell for her
views and critical editing of the APCC Bulletin No. 10. The
support of the Association for the Preservation of Cape Cod is
gratefully appreciated.
REFERENCES
APCC, 1988. Private Well Protection. Informational Bulletin No.
'lO, Association for the Preseravat 1on of Cape Cod, Box 636,
Orleans, Massachusetts 02653
CCPEDC, 1979. Water Supply Protection Final Report. Cape Cod
Planning and Economic Development Commission, Barnstable,
Massachusetts .
DEQE, 1977. State Environmental Code, Minimal Requirements for the
'subsurface Disposal of Sanitary Sewage, Title V. Department of
Environmental Quality Engineering, Boston, Massachusetts.
Driscoll, P.G., 1986. Groundwater and Wells. Johnson Division,
ST. Paul, Minnesota.
325
-------
Eckard, D., Pllpse, W.J. and Oaksford, G.T., 1980. USGS Water
Resources Investigations Report 86-4142.
Guswa, J.H. and LeBlanc, D.R., 1981. Digital Models of Groundwater
Flow in the Cape Cod Aquifer System, Massachusetts. U.S.
Geological Survey Water-Resources Investigations, Open File
Report 80-67.
Horsley, S., 1983. Delineating Zones of Contribution for Public
Supply Wells to Protect Groundwater. Proceedings, National
Water Well Association Eastern Regional Conference of
Groundwater Management, Orlando, Florida. National Water Well
Association, Worthington, Ohio.
Kerfoot, W.B., 1985. The Use of Direct-Reading Groundwater Flow
Meters and Water Levels to Determine the Recovery Zone of a
Pumping Wei 1. Fifth National Symposium and Exposition on
Aquifer Restoration and Groundwater Monitoring, National Water
Well Association, Worthington, Ohio.
Kerfoot, W., 1987. Is Private Well Protection Adequate when
Groundwater Flow is Ignored? Proceedings of the Focus on
Eastern Regional Groundwater Issues: A Conference. National
Water Well Association, Dublin, Ohio.
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BIOGRAPHICAL SKETCH OF AUTHOR
William 8. Kerfoot
William B. Kerfoot is currently the president of K-V
Associates, Inc., 281 Main Street, Falmouth, Massachusetts 02540.
He holds a B.A. from the University of Kansas (1966) and a Ph.D.
from Harvard University (1970). In 1979 K-V Associates, Inc.
introduced the first commercial flow meter for documenting
groundwater flow patterns surrounding porous bottom kettle lakes.
He is currently a member of the Ground Water Technology Division of
the National Well Water Association and a nationally recognized
water quality consultant.
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