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United States
Environmental Protection
Agency
Risk Reduction
Engineering Laboratory
Cincinnati OH 45268
Research and Development
EPA/600/S2-89/027 Feb. 1990
£EPA Project Summary
Point-of-Entry Drinking Water
Treatment Systems for
Superfund Applications
Catherine D. Chambers and Thomas A. Janszen
The U.S. Environmental Protection
Agency (EPA) and State Superfund
agencies need a technical assistance
manual to assist their personnel in
the selection of an effective drinking
water treatment system for individual
households in areas where the
drinking water has been adversely
affected by Superfund site con-
taminants and no other alternative
water supply is available or feasible.
Commercially available water treat-
ment systems for Individual house-
holds are of two basic types: point-of-
use (POU) and polnt-of-entry (POE). A
POU device consists of equipment
applied to selected water taps to
reduce contaminants at each tap. A
POE device consists of equipment to
reduce the contaminants in the water
distributed throughout that structure.
This study was Initiated to collect
monitoring, operation and mainte-
nance, performance, and design data
on existing Superfund POE water
treatment systems. Evaluation of the
collected data showed that existing
data are not sufficient for the
preparation of a technical assistance
document to meet the objectives of
EPA and State Superfund personnel.
There is a need for additional study
to develop a technical assistance
document. Because most of the
existing data and field experience
related to POE water treatment is
concerned with granular activated
carbon filters and air strippers for the
treatment of organic contaminants,
the authors recommend that further
detailed study center around these
two technologies.
This Project Summary was devel-
oped by EPA's Risk Reduction En-
gineering Laboratory, Cincinnati, ON,
to announce key findings of the re-
search project that Is fully docu-
mented In a separate report of the
same title (see Project Report or-
dering information at back).
Introduction
Point-of-entry (POE) systems can take
a variety of forms, entail the use of
various technologies, and be used either
singularly or in combination to address
numerous water quality problems. Gen-
erally, the three contaminant categories
of concern are organic compounds,
inorganic compounds, and microbio-
logical agents. The most common POE
systems for removal of organic chemicals
involve the use of granular activated
carbon (GAC) and/or aeration. Those
used for removal of inorganic contam-
inants can involve reverse osmosis (RO)
or deionization (Dl). Systems used to
eliminate microbiological agents may in-
clude filtration (through ceramic filters),
chemical disinfection, and ultraviolet (UV)
irradiation.
When properly selected, operated, and
maintained, POE systems can be both
effective and safe. Often, the operation
and maintenance of installed units is
critical to health protection. For example,
GAC filters can act as a growth medium
for bacteria. In some cases, water being
treated with GAC may also require some
type of disinfection (e.g., UV irradiation).
Superfund-financed POE water treat-
ment systems have been installed on
individual household wells in which the
well water has been contaminated with
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toxic compounds from a Superfund site.
These installations have been made on a
case-by-case basis depending on the
ability and resourcefulness of the persons
involved.
This report presents the findings of the
study to evaluate POE water treatment
systems for Superfund applications. It
involved an assessment of the status of
currently operating POE systems at
Superfund or comparable sites and the
collection and evaluation of available
operating, performance, and design data
for these systems. Based on this
assessment, recommendations are made
concerning the development of a
technical assistance manual.
Data collection consisted of contacting
EPA Regional Superfund offices to
identify sites where POE treatment is
being used. Several State and local
agencies also were contacted to obtain
information related to State-supervised
POE system installations. The available
information consisted of monitoring data,
system descriptions, some system de-
sign details, and operation and main-
tenance practices. Several suppliers/
manufacturers of the POE treatment
systems also were contacted to obtain
information on the design and operation
of their systems. Data on GAG filter sys-
tems and aeration systems were obtained
from these sources.
Conclusions
Data collection activities resulted in the
following general findings:
• Existing Superfund applications of
POE treatment systems are pri-
marily located in EPA Regions 2, 3,
and 5.
• State and local agencies in Florida,
Maine, New York, and New Jersey
are also applying POE water treat-
ment at sites with types and levels
of contaminants similar to those
found as a result of Superfund site
contamination.
• The application of POE treatment
has occurred primarily at sites
where organic contamination (i.e.,
chlorinated solvents, pesticides, and
petroleum products) has affected
drinking water supplies.
• Granular-activated-carbon (GAG)
filters and air stripping are the two
most common POE technologies
used for treating organic
contaminants.
• The use of GAG filters, either single
units or two units in series, is
successful in treating water
contaminated with chlorinated sol-
vents and pesticides.
• Air stripping, either diffused or
packed-tower aeration, is more
effective than GAG for treating water
contaminated with petroleum
products.
• In some cases, air stripping is used
to pretreat water with elevated
levels of solvents before the water
passes through a GAG filter. This is
done to extend the effective life of
the carbon filter.
• On individual wells in which radon
contamination is a problem, POE
treatment by air stripping is being
used.
Most of the existing Superfund appli-
cations of POE water treatment were
identified during this phase of the study.
Some information relative to system de-
sign and operation was identified; how-
ever, the level of detail of the design in-
formation (i.e., unit specifications) is
somewhat lacking. System suppliers and
designers have been either reluctant or
unable to provide the type of information
needed.
In most cases, no quality control (QC)
data on the analytical data obtained dur-
ing Phase I were available, including test
methods, protocols, and QC samples.
Some samples were analyzed by field
gas chromatographs to determine the
presence or absence of contaminants.
Although these data are useful for deter-
mining contaminant exposure, they may
not provide the level of confidence re-
quired for the development of a technical
assistance document.
Recommendations
Although the POE systems being ap-
plied at Superfund or comparable sites
are capable of effective treatment of the
contaminants of concern, the design, de-
velopment, operation, maintenance, and
monitoring of these systems varies from
site to site. There is a need for additional
study to develop a technical assistance
document. Because most of the existing
data and field experience related to POE
water treatment are concerned with GAG
filters and air strippers for treatment of
organic contaminants, it is recommended
that further detailed study center around
these two technologies for treatment of
organics.
The document user may need specific
guidance on the following technical
issues:
• Design flow requirements for
operating the POE system.
• Sampling points of interest for t
POE treatment systems.
• Design life of activated carbon 1
the contaminants of concern.
• Effect of contaminant mixtures i
carbon life.
• Cost-effectiveness of changing a
tivated carbon frequently versi
sampling and analysis to monitor f
breakthrough.
• Design considerations for spac
restrictions in homeowner
basements.
• Minimum contact time for raw wati
with GAG or air stripping systems.
• Properties of activated carbon cril
cal to designing a POE treatmei
system (e.g., pore size, carbo
mass, particle size).
• Ground-water constituents that a
feet GAG filter or air stripper effec
tiveness or operation (e.g., dis
solved solids, pH, heavy metal;
hardness).
• Spent carbon disposal practices.
The full report was submitted in fulfill
ment of Contract No. 68-03-3413 by PE
Associates, Inc., under sponsorship of th<
U.S. Environmental Protection Agency.
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Catherine D. Chambers and Thomas A. Janszen are with PEI Associates, Inc.,
Cincinnati, OH 45246.
tH?ry K. Stlnson is the EPA Project Officer (see below).
The complete report, entitled "Point-of-Entry Drinking Water Treatment Systems
for Superfund Applications," (Order No. PB 89-195 010/AS; Cost: $15.95,
subject to change) will 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:
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
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