TSCA GROUND-WATER PROTECTION STRATEGY




          Decentoer 10, 1985

-------
              TSCA GROUND-WATER PROTECTION STRATEGY
I.  INTRODUCTION

     Since the late 1970's, ground-water protection has emerged
as a major environmental concern.  Incidents such as the toxic
contamination of ground water in Montgomery County, Pennsylvania
in 1979 and Miami, Florida in 1984 underscored the potential
health effects of toxic substances contaminating ground-water
supplies used for drinking water.

     This paper outlines a plan for using the Toxic Substances
Control Act (TSCA) to address selected problems of toxic
substance contamination of ground water.  The Toxic Substances
Control Act was enacted in 1976 to address concerns related to
production, distribution, and use of toxic chemicals.  At the
time TSCA was introduced, however, ground-water problems
involving toxic chemicals were just beginning to become
nationally known.  As more episodes of contamination have been
discovered in the last few years, concern for the nation's
ground-water resources, and concern for the health implications
of ground-water use, has grown significantly.  This has also
raised concern for possible health effects for contaminated
ground water used as drinking water.

     In response, EPA issued its Ground-Water Protection Strategy
in August, 1984, and the Agency is now focusing more attention
and resources on the problems involving ground-water
contamination.  Two of the primary objectives of the Agency's
Ground-Water Protection Strategy are to identify actual and
potential ground-water problems and to provide a policy framework
for addressing them.  Part of the EPA Strategy is to use TSCA as
an effective means to deal with certain problems related to toxic
chemicals in ground water.

     TSCA is the EPA statute that provides the broadest range of
authority in protecting human health and the environment from
harmful exposure to toxic chemicals.  As a result, it is an
integrative tool which can be used to:

      1.  Collect and assess data on health and environmental
          effects of toxic substances in ground water [Sections
          4, 5, and 8];

      2.  Provide information needed by other EPA programs to
          fully assess existing and potential problems related to
          toxic substances in ground water [Sections 4, 8, and
          9]; and

-------
      3.  Control the production, transport, storage, disposal,
          and use of toxic substances [Sections 5 and 6]  for
          those problems involving ground-water contamination
          from toxic substances which are only partially
          addressed, or remain unaddressed, in other EPA
          statutes.

     The Office of Toxic Substances (OTS) will use TSCA authority
and expertise to help assess the extent of toxic contamination of
the nation's ground water, to collect information on health
effects of those contaminants, and to examine several specific
problems which are thought to be related to pollutants frequently
detected in drinking water.  The EPA Ground-Water Protection
Strategy includes a three-tiered classification system* for
ground-water sources based on use, value, and vulnerability to
contamination.  Information gathered under TSCA authorities will
be used to help determine management strategies for different
ground water classes.  Three specific problems that TSCA's
information gathering authorities can be used to address are
trichloroethylene (TCE) and other volatile organic chemicals
(VOCs), the chemi'cal constituents of fertilizers, and additives
to septic systems.  These represent three different problems
where contamination of ground water has been widespread.

     The overall goal of the TSCA Strategy is to enhance the
Agency's ability to detect, assess, correct, and prevent ground-
water quality problems caused by toxic substances.

II.  EXTENT OF GROUND-WATER CONTAMINATION FROM TOXIC SUBSTANCES

     Over fifty percent of the U.S. population draw upon ground
water for drinking water use.  As a result, toxic substance
contamination of ground water could result in widespread and
serious adverse effects on human health.  At present, however,
not enough is known about either the extent of contamination or
the potential health effects which may result.  But sufficient
information exists to raise concerns that a widespread problem of
ground-water contamination from toxic substances may exist.

     Anecdotal information and a few surveys (such as EPA's
Ground Water Supply Survey) form the essence of information known
to date on the extent of contamination, but these have only begun
to describe the potential problem.  Nearly every State in the
U.S. has detected toxic contamination in ground water.  There is
enough information to emphasize the need for future programs to
focus on preventative actions to protect the resource, while
*Class I includes special waters highly vulnerable to
contamination and either irreplaceable for substantial
populations or ecologically vital.  Class II includes all other
current and potential sources of drinking water and other
beneficial uses.  Class III includes ground waters not considered
potential drinking water sources and of limited beneficial use.

-------
                              - 3 -
efforts to detect and deal with serious contamination resulting
from past actions continue.  The information we now have
indicates the potential for health and environmental problems
which, if not prevented, could reap serious social and economic
impacts on a scale heretofore unknown.  Cleaning up contaminated
ground water is difficult, expensive, and often unsuccessful.

     Indication of potential exposure includes:

      1.  Nearly 8,000 private, public, and industrial wells have
          been closed or otherwise affected by toxic substances
          and other forms of contaminated ground water;

      2.  Volatile organic chemicals are found at detectable
          levels in 20% of public drinking water supplies and 30%
          of supplies serving over 10,000 people;

      3.  Concentrations of toxic compounds in ground water are
          often much higher than in surface water; and

      4.  Of 38 inorganic substances being surveyed by EPA, 26
          have already been detected in ground-water supplied
          community water systems.  Although this is not in
          itself a measure of concern, the levels at which many
          of these chemicals are being detected raise questions
          of possible health concerns.

     On the health effects side, EPA's Office of Drinking Water
(ODW) is currently developing drinking water standards and health
advisories for some of the toxic substances most commonly found
in ground water.  More information is needed to fully assess
health related problems on additional chemicals, so drinking
water standards or health advisories can be developed for
important chemicals not among the most commonly found.  Previous
monitoring efforts have generally looked for a limited number of
chemical pollutants, so there is little information on the range
of pollutants that might be found in ground water.  A more
systematic look at identifying previously unidentified pollutants
is needed, and the health effects of these pollutants assessed.

     A number of ground-water monitoring efforts have been undertaken
to assess the problems resulting from toxic contamination, but they
have not resulted in a systematic picture of the extent of ground-
water contamination.  Systematic methods must be developed to ensure
that the worst problems are discovered early enough to clean up, or
that potentially vulnerable areas are identified for preventive
measures.  The present ground-water contamination problems are
expected to appear more severe as additional information is collected,
since many currently unrecognized sources are undoubtedly contributing
to the problems.  It is necessary that future studies indicate the
relative significance of various sources to the contamination of
ground water and provide information concerning the fate of
contaminants and their potential impact on human health and the
environment.

-------
     Sources where ground-water contamination from toxic
substances has been found include:  industrial and municipal
landfills; aboveground and underground storage tanks; pesticide
and fertilizer applications; irrigation practices; oil and gas
wells; mining and mine drainage; waste piles and tailings;
pipelines; materials transport and transfer operations; de-icing
salt applications; urban runoff; animal feedlots; radioactive
disposal sites; underground injection activities; open dumps; and
septic systems.

     In reviewing what is currently known, it is clear that
little systematic information exists today on either the extent
or the potential health impacts of toxic contamination of ground
water.  Furthermore, in those areas where problems have been
detected, it has often been difficult to determine the source(s)
of the contamination.  Finally, little has been done to date to
try and identify and prevent future contamination problems.  The
TSCA Strategy will focus, in the short term, on using the
information-gathering authorities under TSCA to provide
appropriate data necessary to address these areas.  In the long
term, the TSCA Strategy will concentrate on controlling
contamination from toxic substances.

III.  TSCA STRATEGY FOR GROUND-WATER PROTECTION

     The overall goal of the TSCA Ground-Water Protection
Strategy is to use TSCA authority and expertise to enhance the
Agency's ability to detect, assess, correct, and prevent ground-
water quality problems caused by toxic substances.  Four
objectives have been identified as key elements in achieving that
goal:

      1.  To develop information needed to identify current
          ground-water contamination problems and to determine
          the potential for future ground-water contamination
          from toxic substances;

      2.  To develop information needed to determine the health
          effects resulting from specific chemicals contaminating
          ground water;

      3.  To improve ground-water assessment methods and to
          incorporate those methods into risk assessments for new
          and existing chemicals; and

      4.  To adopt appropriate controls to prevent or reduce the
          introduction of toxic substances and fertilizer
          components to ground waters.

     The following paragraphs discuss the needs under each of
these objectives, the current activities relevant to those needs,
and the actions EPA plans to take in both the short term (FY86-
87) and long term (FY88 and beyond).

-------
                              - 5 -



A.    Development of information to identify problems.

      1.  Information collection plan.

     No comprehensive or systematic data base exists which
summarizes the extent of ground-water contamination, although
there are many sources of information that provide limited
data.  As a practical matter, the lack of information on the
extent of ground-water contamination and the sources of that
contamination must be addressed before any meaningful steps can
be taken to either clean up existing problems or prevent future
problems.  The Office of Toxic Substances (OTS), in working with
the Office of Ground-Water Protection (OGWP), has prepared a plan
for developing information for both existing problems and
identifying possible future problems.

     The plan has six components:  (a) developing a system for
identifying geographic areas of highest priority to study for
potential ground-water contamination problems, and applying this
priority-setting system to a number of projects; (b) developing a
system for determining sources of ground-water contamination for
a given geographical area; (c) collecting or developing
information on TCE and other VOC contamination of ground water,
and using the systems developed above to help identify likely
sources in high priority areas; (d) collecting or developing
information concerning the components of fertilizers that may be
contaminating ground water; (e) collecting or developing
information concerning ground-water contamination by toxic
substances as a result of septic systems; and (f) performing a
broad-scan analysis of ground-water samples in certain priority
areas to identify contaminants not previously identified using
past analytical procedures.

     Each of these components is discussed below.

      2.  Priority setting system for future work.

      a.  Discussion.  Sampling and analysis for ground-water
contaminants can be time-consuming and expensive.  Given the
current lack of systematic data on the extent of ground-water
contamination by toxic chemicals, a nationwide survey would be
prohibitively expensive.  On the other hand, field data need to
be developed to allow a clearer picture of the extent of the
potential problems which may emerge.  OTS needs to develop a
system to identify geographical areas where limited field work
(or other information collection) might take place to better
define specific problems, such as the VOCs, fertilizers, and
septic system projects described below.

-------
                              - 6 -
          Current Activities.  There are several activities in
other organizations related to identification of contamination
problems.  EPA's Office of Pesticide Programs (OPP) and Office of
Drinking Water (ODW) are planning a monitoring survey beginning
in FY86 to determine the extent of pesticide contamination in
ground water.  OTS will participate in work group efforts related
to this survey and coordinate the OTS efforts in the fertilizer
area with the OPP/ODW survey.

     The Office of Solid Waste, under RCRA authority, has a
limited amount of monitoring data on ground water beneath
hazardous waste facilities, as well as information on pits,
ponds, and lagoons located at manufacturers' plants.

     EPA's Office of Research and Development has conducted a
ground-water research program for almost 20 years to improve the
capability to predict the movement and transformation of organic
chemicals in the subsurface environment, improve monitoring
methods, and more recently, to determine the cost and
effectiveness of aquifer restoration methods.  The EPA Ground
Water Protection Strategy as well as this TSCA Strategy will
depend on maintenance of a strong continuing research program to
accomplish their goals.

     Under the Superfund Program, ground-water criteria are a
major (although not the sole) consideration in feasibility
studies for remedial action.  The sites where data are developed
may or may not be sites with the worst ground-water problems, but
useful monitoring data for some sites may be available.

     The U.S. Geological Survey (USGS) is a primary source of
hydrogeological data on the overall state of the nation's ground-
water resources.  USGS has undertaken cooperative efforts with
States to appraise ground-water resources and develop information
on land use related to hydrologic systems.  Fourteen studies have
been conducted on the fate and movement of contaminants in ground
water, and USGS is expanding this effort, called the National
Program of Toxic Wastes in Ground-Water Contamination.  The
outcome of this effort will be a better understanding of the
processes which control the movement of contaminants in ground
waters.  This work will facilitate the efforts at EPA to develop
information leading to greater protection of ground water related
to the actual or potential contamination from toxic substances.

     EPA and the Department of the Interior signed a Memorandum
of Understanding June 21, 1985, which will promote exchange of
information and cooperation between EPA and USGS.

-------
      c.  Plans.  In FY86, OTS plans to develop a system for
prioritizing areas to study for a variety of possible projects.
The system will focus on inherent hydrogeologic vulnerability as
well as existing and potential ground-water use.  A report
describing the system will discuss the merits and disadvantages
of various ranking tools (DRASTIC Index, exposure models, etc.),
information needed to do the ranking, and compatibility with
supporting the EPA ground-water classification system.  The
report will also discuss the merits, disadvantages, costs,
appropriateness, and potential effectiveness of various ways to
get the information needed to do the ranking (Section 8 rules,
consumer surveys, field work, etc.).  This system will later be
used in specific cases to determine areas for investigation in
the septic systems, fertilizers, and VOCs projects.

      3.  Development of a system for identifying sources of
          ground-water contamination.

      a.  Discussion.  One of the more difficult problems facing
the Agency is the tracing of sources of contamination once
chemicals are detected in ground water.  A good example of this
problem is illustrated by trichloroethylene (TCE), which is found
in many ground-water sources at low concentration levels.  Due to
the many uses of TCE and its diverse distribution in commerce, it
presents a particularly complex challenge if the Agency needs to
control the sources.  A systematic method of approaching the
problem of source identification is needed.

      b.  Current Activities.  Although many studies of ground-
water contamination have identified sources, a general systematic
approach to the problem of identifying sources has not been
developed.

      c.  Plans.  OTS plans to use its expertise in exposure
assessment to develop a system for determining sources of ground-
water contamination for chemicals in a given area.  The system
would employ a decision-tree approach to predicting sources, then
look at various mechanisms for collecting needed data to verify
sources.  The mechanisms discussed will include Section 8 rules,
letter writing, consumer surveys, hydrogeological/geochemical
investigations, etc., and discuss the relative merits,
disadvantages, costs, appropriateness, and potential
effectiveness of each mechanism.  A report on the general system
for identifying sources will be done in the short term, then the
system would be applied later in the three specific projects
(VOCs, fertilizers, septic systems).

-------
      4.  Determining sources of VOCs in ground water.

      a.  Discussion.  VOCs have been detected in numerous public
water systems across the country.  Although contamination is
typically at low levels (less than one part per billion), higher
levels have been found in some systems.   Although VOCs are
frequently detected contaminants around hazardous waste sites, it
is unclear that the increasing amounts of VOCs being detected in
ground water are due to hazardous waste sites.  It is also
unclear what other sources of contamination may exist.

     The presence of VOCs raises considerable concern, because
several have been identified as suspected carcinogens, mutagens,
and/or teratogens.  Numerous other chronic and acute toxic
effects are attributed to many of the VOCs.  Estimates have been
made of as high as 6.4% of the nation's ground-water supplies
having detectable levels of tricholoroethylene (TCE), one of the
VOCs.  VOCs are also a major class of chemicals frequently found
in RCRA and Superfund sites.

      b.  Current Activities.  The uses and monitoring data for
several of the VOCs, including TCE, have been the focus of
information collection within EPA for several years.  Agency-wide
work groups have been formed on several of the VOCs to share
information and discuss possible risks associated with these
chemicals.  To date, however, no systematic effort to identify
specific sources of ground-water contamination has been
undertaken.

      c.  Plans.  In the short term, EPA plans to use the methods
developed under #2 above to select high priority areas for study
of these contaminants.  Much is known about the production and
use of TCE, for example, and this information could be used to
set up hypotheses as to the sources of TCE in these areas.  These
hypotheses can be checked during any subsequent field work in the
areas by incorporating the appropriate sampling into the field
study design.  In the long term (FY88),  EPA plans to apply the
system developed for identification of sources to the VOC
problem.  The results of this effort may lead to information
collection rules or control rules for various sources.

      5.  Determination of possible ground-water contamination
          from fertilizer use.

      a.  Discussion.  The monitoring of select aquifers
indicates that nitrate levels in the ground water of shallow
aquifers underlying agricultural lands have increased
substantially in the past 20 to 30 years.  The use of chemical
fertilizers in the United States has increased from 20 to 40
million tons per year from 1950 to 1970.  Recent figures (1982-
83) indicate a leveling off at 42 million tons after reaching a
peak of 54 million tons in 1980-81.  In addition the average
percentage of nitrogen in all fertilizers has increased from 6.1
to 20.4 percent.

-------
                              - 9 -
     Agricultural use of fertilizers is believed to constitute a
major source for nitrate contamination of shallow aquifers.
Nitrate levels in ground water of the Big Springs area of
Northeastern Iowa have increased from a background level of 10
ppm in 1955 to a current background level of 40 ppm.   Similar
increases have been documented in the ground water underlying the
Platte River Valley of Nebraska.

     Nitrate in drinking water was first associated with infant
methemoglobinemia in 1945.   Since then a total of 2000 cases have
been reported in the United States and Europe, but since the
disease is not "reportable" in the U.S., there may have been
substantially more cases.  Nitrate in ground water has been
"suggested" as a possible factor in other health related
problems, to include: cancer, nervous system impairments, and
birth defects.

     Metals (Cd, Se, Mo, U) present in trace amounts in the
phosphate rock used to produce the superphosphate component of a
mixed fertilizer constitute another potential source of ground-
water contamination.

      b.  Current Activities.  Other than product performance
standards, transportation safety, and point source effluent
guidelines, there is little Federal regulation of fertilizers.
Other than a lOmg/L drinking water standard for nitrate(N), which
is now under reevaluation,  there is no current regulatory effort
dealing with potential human and environmental harm resulting
from fertilizer use.  EPA's Office of Water, however, is
considering the effects of  fertilizer use as a non-point source.

     U.S. Geological Survey has been collecting and analyzing
data on nitrate levels in ground water using their computerized
data base WATSTORE for over 25 years.  In 1984, USGS used this
information to summarize occurrence and distribution of elevated
concentration levels on a national scale.  This is the first
attempt of any federal agency to characterize nitrate occurrences
nationwide.  The report cited chiefly two areas where research is
needed, namely, further evaluation of health risks and fate and
transport studies of nitrogen fertilizers.

     The U.S.  Department of Agriculture (USDA) has focused
efforts on the impact of agricultural activities on ground-water
quality and the fate and transport of pesticides.  Over the past
15 years, the Extension Service and Soil Conservation Service has
advised split application of fertilizers, but possible health
effects of long-term fertilizer use have not been determined.
Several programs, for instance in Long Island, have developed
some data on lawn-use of fertilizers, but such studies are
sporadic.

-------
                            - -  10  -
      c.  Plans.  In the short term, OTS plans to gain a better
understanding of fertilizer constituents, including contaminants,
and the suspected linkage between fertilizer usage and nitrate
contamination of groundwater.  Because little is currently known
about the potential for ground-water contamination from either
nitrate or other toxic substances, information collection is the
first priority.  To get some idea of the magnitude of possible
contamination, consideration will be given to the opportunity to
sample ground water in agricultural areas in conjunction with the
Office of Pesticide Programs/Office of Drinking Water's ground-
water monitoring program mentioned earlier.  After these data are
obtained, existing information on fertilizer use, land management
practices, and fertilizer content can then be compared with
monitoring data to look for correlations.

     In the long term, OTS may do limited field work in areas
ranked as high priority for potential fertilizer contamination.
In any field work done in the high priority areas, information on
the use of fertilizers by homeowners would be important so the
non-farm use of fertilizers can be addressed.  It may be
necessary to use section 8 of TSCA to supplement published
information.

     A better understanding of the leaching dynamics of
fertilizer-related pollutants is also needed to develop
predictive models.  Section 4 of TSCA can be used to require fate
testing for those components suspected of causing ground-water
contamination.  Data gaps also exist in the areas of human and
environmental effects which may occur as a result of nitrate
contamination of water supplies.  Section 4 of TSCA can also be
used to require these tests.

     In the long term, following the establishment of a
sufficient data base to clearly define the problem and to
indicate practicable regulatory approaches, a number of remedial
approaches are possible under TSCA including labeling (e.g.,
application restrictions, geographic restrictions) and use of
chemical advisories.   It is clear that any regulatory approach
selected, however, would need to balance the large benefits.from
fertilizer use against any health or environmental effects.
Consideration should be given to cooperative public education and
information programs in conjunction with the USDA to encourage
efficacious use of management practices that could reduce usage
without severe economic impact and control use in areas where
fertilizer is likely to leach or runoff into water supplies.

-------
                              -  11  -
      6.  Development of information concerning toxic substance
          contamination from septic systems.

      a.  Discussion.  One trillion gallons of liquid waste are
discharged from septic tanks each year and household septic tanks
are the largest single discharge source of wastewater.
Contamination of ground water from septic tanks results from both
normal and improper use of these systems.  Properly functioning
septic systems continuously deliver nitrate, metals, VOCs, and
other organics to shallow ground water.  In urban areas the
nitrate loading from septic systems is comparable to that from
the use of lawn fertilizers.  The use of cleaners containing
chlorinated solvents to clear clogged drainfields can cause
serious contamination of underlying aquifers.  Additionally, high
levels of organic contaminants have been found in ground water
near commercial and light industrial facilities that use septic
systems.  For example, in Lakewood, WA, EPA confirmed that
municipal drinking water wells were contaminated with 1,2-
dichloroethylene (200-600 ug/L) and tetrachloroethylene (600-1300
ug/L).  The source was identified as a septic tank drain field at
a laundry and dry cleaners.  In Florida a statewide small waste
generator survey uncovered a variety of light industrial
establishments such as plating shops and automotive repair shops
operating in areas zoned for warehouses and discharging their
wastes to septic ststems.  A similar survey on Long Island
identified commerciall dry cleaners as a source of ground-water
contamination.  Soil type, hydrogeological characteristics of the
area, and the density of individual units are important factors
in assessing vulnerability of ground water to septic system
contaminants.

      b.  Current Activities.  The permitting of septic tank
installation or the regulation of their use is almost always done
on a local or state level and it is not anticipated that this
TSCA Strategy would affect this process.  Within the last five
years OTS has expended a low level of effort to gather
information on septic tank additives.  EPA's Office of Water and
Office of Research and Development have conducted numerous
studies on design and management of septic systems.  OGWP is
currently preparing a Technical Information Document on septic
system control programs.

      c.  Plans.  In the short term, OTS plans an investigation
to clarify which geological situations are likely to favor
contamination of ground water by solvents or other septic tank
additives.  For areas with these characteristic, surveys can be
conducted to determine what introduced products are likely to
cause contamination problems and to clearly establish that the
appearance of these products in ground water is due to leakage
from septic tanks and not the result of contamination from waste
sites.  For commerical or industrial septic systems, methods
similar to 13 above can be utilized to determine the types of
business and mumber of facilities needed to support a specified
population size.  Combined with data on chemicals used and

-------
                              -  12  -
disposed of by these facilities, an estimate of contaminant
loading to ground water could be made and then verified for
vulnerable areas by monitoring in limited field studies.  In the
long tern, the incorporation of the EPA Ground-Water Protection
Class I, II, and III source classification system should be a
prime consideration in devising and refining an advisory or
regulatory program for additives of septic systems.  More
stringent criteria for siting of septic tanks over Class I
sources would be a possible recommendation to local authorities,
perhaps through a non-regulatory approach (Chemical Advisories)
providing the results of EPA's information gathering efforts to
local authorities.  Finally, because septic tanks, like
fertilizers, are a source of nitrate contamination, the
investigation of nitrate contamination from fertilizers and
septic tanks should be closely coordinated.

      7.  Broad-scan analysis of ground-water samples for
          previously unidentified contaminants.

      a.  Discussion.  Most monitoring efforts focus on a list of
contaminants selected a priori, and during analysis of samples,
only these chemicals are quantified, regardless of what
additional chemicals may be present.  This procedure allows a
substantial savings in cost for the analytical work.  Because of
this practice, however, the full extent of pollutants in ground
water may not be known.  An effort is needed to determine which
pollutants other than the VOCs, metals, and pesticides currently
being measured are important in terms of health effects.

      b.  Current Activities.  OTS currently collects human
exposure data on a nationwide basis, taking samples of human
tissues and fluids from the general population and subjecting
them to broad chemical analyses.  Experience from this program
indicates that humans are being exposed to a number of chemicals
not normally measured in current analytical schemes.  This may
also be the case for exposure through drinking water using
ground-water sources.

     ODW is proposing monitoring for 52 unregulated VOCs as part
of its Revised Primary Drinking Water Regulations.

      c.  Plans.  In the short term, the broad chemical analyses
from the human monitoring program will yield data on toxic
chemicals to which humans are exposed.  Analysis of these data in
wide geographical areas ranked as high priorities in a screening
step for vulnerable areas may result in a list of toxic chemicals
with known human exposure in those areas.  Chemicals suspected of
contributing to exposure through the drinking water route should
be among those looked for in any ground-water monitoring done in
these areas.

-------
                              -  13  -
     In the long term, design and implementation of limited field
studies to statistically survey the high priority areas for
chemical contamination would then result in a defensible answer
to the question of extent of contamination for those high
priority areas.  The mechanism for performing these field studies
could be either a special OTS field study or a cooperative effort
with another organization such as USGS or OPP; the most efficient
and effective mechanism needs to be determined.
B.    Development of information needed to determine health
      effects.

      1.  Discussion.  EPA's Office of Drinking Water is
currently developing drinking water standards for some of the
most commonly found toxic substances in public water supplies.
Health advisories are also issued to inform the public of the
contamination level which, if exceeded, could lead to adverse
health effects at different periods of exposure.  As a result of
efforts to better characterize the extent of contamination
(discussed above), EPA expects to identify chemicals that either
have previously been unreported in drinking water, or that have a
more widespread occurrence than is currently known.  For these
chemicals, it is likely that health advisories or drinking water
standards may need to be established, but complete data defining
health effects may not exist.

      2.  Current Activities.  The Office of Drinking Water has
the principal role in the Agency for developing standards and
guidelines (Health Advisories) for drinking water contaminants.
As part of this effort, ODW has developed, for example, acute as
well as chronic data for nitrates, a primary substance in
fertilizers, but subchronic data (i.e., 90-day studies) are
needed to more fully determine health effects.  ODV7 has currently
issued drinking water standards for 10 inorganic and 10 organic
substances, as well as for several additional radionuclides and
microbial contaminants.  They are currently in the process of
setting standards for an additional 35 organic chemicals and
reexamining the standards for inorganic, radionuclide, and
microbial contaminants.  In addition, they have issued health
advisories for 22 chemicals and are currently preparing health
advisories for an additional 25 chemicals.                .

      3.  Plans.  For TSCA-related toxic substances with
demonstrated widespread exposure, such as the chemicals found in
ground water used for drinking water, TSCA has the authority
under section 4 to require manufacturers of these chemicals to
provide health effects data where data gaps exist.  In the short
term, OTS will work with ODW (advised, where appropriate, by
OGWP) to determine the health effects data needs for those toxic
substances currently under consideration for health advisories or
drinking water standards.  This coordinated effort may result in
one or more section 4 test rules.  In the long term, information
from the broad-scan analysis described above may identify

-------
                                14  -
chemicals where previously unrecoginzed widespread exposure is
demonstrated, but little toxicity information exists.  EPA plans
to evaluate the potential impact of these chemicals by looking at
exposure levels and known toxicity, setting priorities based on
this screening evaluation, and investigating the use of section 4
or section 8(d) to acquire data for eventual consideration of
health advisories or drinking water standards.

C.    Improve ground-water assessment methods for new chemical
      and existing chemical risk assessment.

      1.  Discussion.  TSCA provides a unique opportunity to
prevent future ground-water contamination, because new chemicals
must be assessed for potential risk.  Under section 5 of TSCA
manufacturers or importers of new chemicals must file a
premanufacture notice (PMN) with EPA before commercial
manufacture or import commences.  OTS then assesses the
chemical's potential risk, and if it may be an unreasonable risk,
testin-j requirements, exposure control requirements, or a ban may
be imposed.  Potential ground-water contamination from new
chemicals has been routinely assessed in the PMN program using
state-of-the-art techniques.  Similar techniques, along with
existing monitoring data, have been employed in OTS1 existing
chemicals program in the evaluation of ground-water problems
posed by existing chemicals.

     As more is becoming known about ground-water contamination,
more sophistication is needed in the state-of-the-art assessment
techniques to adequately address the problem.  Little is known,
for example, about the relative frequency of various events
leading to contaminated ground water (leaching through relatively
homogeneous soil, for example, vs. contamination aided by soil
heterogeneities such as cracks, root tubes, etc.).  Existing
models tend to treat soil layers in a given area as homogeneous,
limiting the assessments done to date.  In addition to the
limitation of current models and ground-water contamination data,
more focus is needed on the unique problems in assessing impacts
of contamination of ground water for both drinking water and
other beneficial uses.

      2.  Current Activities.  Ground-water models, including
both saturated zone and unsaturated zone models, have been under
development in EPA (and elsewhere) for a number of years.  OTS
has a close working relationship with EPA's Office of Research
and Development (ORD), and both are working actively to improve
the state-of-the-art in this area.  ORD work done in FY84-85 for
OTS, for example, investigated ways of validating unsaturated-
zone models and laboratory tested several models (developed by
OTS and ORD-OPP) in controlled settings.  In FY85, OTS sponsored
a task to begin examining the question of frequency of events
leading to ground-water contamination- that might not be predicted
using the current modeling state-of-the-art.

-------
                              -  15  -
      3.  Plans.  OTS plans a substantial effort in FY86 to
strengthen the assessment techniques for both the PMN program and
the existing chemicals program.  By the end of FY86, OTS plans to
develop guidance for use in exposure assessment for both
programs.  This guidance will be for use of OTS assessors in
focusing on the unique problems and complications presented by
ground-water exposure assessment.  In the long term, OTS plans to
continue working with ORD and other organizations both inside and
outside EPA to assure state-of-the-art techniques will be used by
OTS assessors, and to encourage improvements to those techniques
where needed.

D.    Controls to prevent or reduce the introduction of toxic
      substances to ground waters.

      1.  Discussion.  With increasing concern over ground-water
issues in the past few years, and with the planned information
collection activities described above, EPA anticipates that TSCA
regulatory authority may be necessary to deal with some problems
related to toxic substances in groundwater.  Certainly section 5
authority will be used to deal with new chemicals.  The three
specific projects noted above (VOCs, fertilizers, septic
systems), after information collection efforts designed to define
the scope of the problems, may result in actions ranging from
TSCA Chemical Advisories (non-regulatory information
dissemination) to restrictions under section 6 of TSCA.  Although
information-collection rules (e.g., section 4 or 8 rules) may be
forthcoming under this Strategy in the next two years, it is
unlikely that section 6 controls will result during that
period.  What is needed in the short term, however, is an
examination of risk management alternatives for the unique
problems presented by toxic substance ground-water
contamination.  The EPA Ground-Water Protection Strategy stresses
the necessity for coordination and consistency among EPA's
ground-water protection efforts.  In keeping with the EPA
Strategy, the TSCA control action strategy must fit, along with
programs from other organizations, as a part of a larger, fully
coordinated effort.

      2.  Current Activities.  The Office of Ground-Water
Protection is actively working with a number of organizations
both inside and outside of EPA concerning their current actions
and plans.  As part of this effort, OGWP has been chairing
various workgroups to coordinate and promote activities in the
ground-water area.  OTS has been working with OGWP and other
offices in one such work group since January, 1985.  This
strategy is the result of that work group's efforts.

-------
                              -  16  -
      3.  Plans.  In the short term, OTS plans to use the
regulatory authority of section 5 of TSCA to reduce potential
ground-water threat for those new chemicals where an unreasonable
risk will occur.  The OTS-OGWP work group will be expanded and
will immediately begin examination of the relative usefulness,
cost, and appropriateness of the many risk management
alternatives available under TSCA for dealing with existing
ground-water contamination problems.  During the next two years,
this work group will actively work toward a control strategy
integrated with other offices' efforts.  In the long term,
control actions, if necessary under TSCA, can be designed to be
effective and coordinated responses to a very complex problem.

IV.   SUMMMARY

     TSCA can significantly help the EPA ground-water protection
effort,  both by collecting information needed by the Agency and
by addressing certain problems not addressed by other offices.
This TSCA Ground-Water Protection Strategy describes an
aggressive program to deal with an important and complicated
problem.  The effort will begin immediately and will be
coordinated with other organizations through the OTS-OGWP work
group,  which will be expanded to include other offices, Regional,
and State participation.  An early goal of the work group will be
to develop an implementation plan which discusses in greater
detail the concepts and projects presented in this Strategy.  The
following paragraphs outline the short-term and long-term
programs.

     Short-term efforts (FY86-87) will start on information
collection and methods development in FY86.  The information and
methods will quickly be put to use starting in FY87 with the
investigation of three specific problems where toxic chemicals
are known to be contaminating drinking water, namely VOCs,
components of fertilizers, and additives to septic systems.
Short-term efforts will also result in guidelines for better OTS
ground-water exposure assessment and a better focus for future
research needs.

     The long-term (FY88+) program will emphasize integrated
problem solving (i.e., use of the best control, whether TSCA or
another method) in dealing with protection of ground-water
contamination from toxic substances.  Long-term research needs
will focus on more sophisticated assessment techniques
commensurate with the level of complexity of control decisions.
Long-term information collection activities will be oriented
toward obtaining data for both OTS and other program office use.

     Finally, this Strategy will be updated before the long-term
program begins, to reflect the results of information collected
in the short term.

-------