United States
Environmental Protection
Agency
Office of Exploratory
Research
Washington DC 20460
Research and Development
EPA-600/S6-84-004 Mar. 1984
v>EPA Project Summary
Institutional Responses to
Contamination of Ground Water
Used for Public Water Supplies:
Implications for EPA R&D
Programs
Theodore R. Breton and Steven N. Payne
The objectives of this ground-water
assessment were threefold: (1) to im-
prove the U.S. Environmental Protec-
tion Agency's (EPA's) understanding of
problems faced by the states and
municipalities in ensuring that ground-
water is safe for drinking; (2) to provide
guidance to EPA in setting research and
development priorities in ground water
and drinking water areas; and (3) to pre-
sent data on the original and final sets
of ground-water contamination cases
examined, with source lists for contacts
at each organization dealing with the
problem.
The scope of this assessment includes
public water systems with confirmed
drinking water contamination from syn-
thetic organic chemicals in ground
water. From a preliminary list of munici-
palities with ground-water contamina-
tion problems, a group of cases was
selected for in-depth analysis. These
select cases, chosen with the assistance
of regional EPA and state officials, were
studied through site visits and extensive
telephone interviews.
This Project Summary was developed
by EPA's Office of Exploratory Re-
search, Washington, DC, to announce
key findings of the research project that
is fully documented in a separate report
of the same title (see Project Report
ordering information at back).
Introduction
Ground water is a vast but vulnerable
natural resource. About 25 percent of all
fresh water used in this country comes from
ground water sources, and somewhat over
50 percent of the U.S. population relies on
ground water, often untreated, as a primary
source of drinking water. Ground-water use
is proportionately higher for small water
utilities and in rural areas, where over 90 per-
cent of the population is dependent upon
public or, more often, private wells for drink-
ing water. Although more than 20 trillion
gallons of ground water are withdrawn an-
nually, the nation is not facing a problem
with the quantity of ground water, because
natural recharge is usually ten times as large
as withdrawal.
The current problem associated with
ground-water supplies is with quality rather
than quantity. In many instances, organic
chemicals are associated with ground-water
contamination. Even though national or-
ganics monitoring programs earlier focused
attention on trihalomethanes in surface
water systems, as recently as five years ago,
ground water was still thought to be rela-
tively secure from organics contamination.
Several major national studies by EPA
from 1975 through 1979 showed that a
number of volatile chlorinated hydrocarbons
(besides trihalomethanes) were frequently
found in ground water. More recent studies
confirmed earlier reports that several organic
chemicals associated with solvents, espe-
cially trichloroethylene and tetrachloro-
ethylene, were present in a significant
number of water systems using ground
water.
A recent survey showed that EPA drink-
ing water research and development
-------
assistance was the highest priority request
from the States. The largest areas of con-
cern in the drinking water field are related
to the measurement, assessment, chronic
health effects, and treatment of trace
organics in ground water. This study was ini-
tiated to investigate trends in cases of
ground-water contamination and to com-
ment on the needs of States and munici-
palities in studying and resolving local cases
of drinking water problems caused by con-
taminated ground water. The final report is
organized into sections addressing the
methodology employed, characteristics of
the cases analyzed, research and develop-
ment needs, and conclusions on trends in
organic contamination of ground water. In-
cluded as appendices in the final report are:
the results of the initial survey of water
systems, complete case studies, and a list
of contacts at every agency involved in each
case.
Technical Discussion
In the course of this study, several distinct
patterns of ground-water problems became
apparent. Eighty percent of the cases in-
volved trichloroethylene, detected at levels
as high as 5,700 ppb in public wells.
Tetrachloroethylene, trichloroethane, and
other volatile halogenated organic com-
pounds were detected less frequently and at
lower levels. The major sources of these
organic solvents were military contractors or
airports, followed closely by plating in-
dustries, electronics industries, and chemical
waste handlers. The most common point
sources of pollution were leaking under-
ground tanks or improper disposal of sol-
vents. Several patterns of institutional
response became apparent during the study.
When organic-contaminated drinking water
was identified, the local water utility would
close the contaminated wells immediately
and invoke conservation measures or pur-
chase water to replace lost capacity. State
and technical consultants would then deter-
mine the source of contamination and
restore long-term water supplies. In the ma-
jority of cases, new or recompleted wells
were selected over water treatment or
aquifer rehabilitation as a long-term water
source.
Typically, local water authorities would be
working with the county health or en-
vironmental department, the state health
department and environmental agency, and
regional U.S. Environmental Protection
Agency (EPA) officials. The capabilities of
state agencies, which often took the lead in
resolving ground-water contamination cases,
varied widely. The State of New York, for
example, has studied organics in ground
water extensively, while the State of
Washington has barely enough staff or fund-
ing to conduct any investigations at all.
Several states, such as Arizona, have set up
their own versions of Superfund (CERCLA)
to attempt to respond to hazardous waste
problems. The Department of Defense also
has become involved in a significant number
of cases through programs such as the Air
Force's Installation Restoration Program.
The major technical deficiency en-
countered was a paucity of information on
the health effects of organics in drinking
water and a lack of consistent health
guidelines. Evaluating the hazards of keep-
ing contaminated wells in service, informing
the public, and designing treatment tech-
niques were all made difficult by weaknesses
in health data and inconsistencies in recom-
mended allowable levels of contamination.
Tracing the sources of organics in ground
water was a serious problem. Several in-
vestigations were limited by costly drilling
techniques, by complicated data re-
quirements for ground-water modeling, or by
an overall lack of institutional coordination.
Many regions face a shortage of qualified
hydro/geological personnel to carry out ex-
tensive subsurface studies.
The state-of-the-art of treatment tech-
niques to remove organics from drinking
water was not a limiting factor; either EPA
personnel or engineering consultants were
able to design effective treatment plants.
Aeration techniques were usually employed,
although little is known about the levels of
air contamination due to aeration. The major
constraints in designing treatment methods
were the uncertainties in specifications for
allowable effluent levels of organics. Most
municipalities examined in this study handled
the problem of organic chemicals in their
ground-water fairly well, but more work is
needed to improve several areas of response.
The most critical research and development
need for states and municipalities is in health
effects research, followed by establishment
of consistent guidelines or standards for
organics in drinking water. The dissemina-
tion of technical information on detection,
analysis, and engineering control techniques
is also necessary to help local and state of-
ficials to make informed decisions on resolv-
ing problems with organic contaminants in
ground water.
In most cases, testing and monitoring
techniques were adequate; however,
development of more comprehensive and
less expensive methods of analysis and
development of standardized monitoring
protocols would improve the detection and
resolution of organic contamination
problems.
Theodore R. Breton and Steven N. Payne are with ICF Incorporated Washington
DC 20006.
Marvin Rogul is the EPA Project Officer (see below).
The complete report, entitled "Institutional Responses to Contamination of
Ground Water Used for Public Water Supplies: Implications for EPA R&D
Programs," (Order No. PB 84-140 326; Cost: $19.00, subject to change) wit/be
available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Office of Exploratory Research
U.S. Environmental Protect/on Agency
Washington. DC 20460
U.S GOVERNMENT PRINTING OFFICE. 1984—759-015/7610
-------
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
5Ss
STREET
IL 60604
------- |