INDICATORS FOR MEASURING PROGRESS
IN GROUND-WATER PROTECTION
Office of Water
Office of Ground-Water Protection
U.S. Environmental Protection Agency
April 1989
U.S. Environmental .T;;- : .<_.; A.M.-:
Region 5, Library C'vL-l'o'
230 S. Dearborn Stto-ij, nooin 1570
Chicago, IL 60604
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CONTENTS
Pace
ACKNOWLEDGEMENTS j_
EXECUTIVE SUMMARY ±i
I. INTRODUCTION 1
II. SELECTION OF THE INDICATORS 3
III. PUBLIC WATER SUPPLIES 6
IV. HAZARDOUS WASTE SITES 13
V. WASTE SITES AND INDUSTRIAL SITES 21
VI. AREA-WIDE SOURCES GENERALLY 29
VII. AREA-WIDE SOURCES OF POTENTIAL PESTICIDE CONTAMINATION 34
APPENDICES
A. THE ROAD NOT TAKEN INDICATORS REVIEWED BUT NOT CHOSEN
B. INDIVIDUALS AND ORGANIZATIONS INTERVIEWED
C. SURVEY FORM FOR HAZARDOUS WASTE SITE STATUS INFORMATION
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FIGURES
Paoe
1. PERCENT OF DRINKING WATER SYSTEMS WITH MCL VIOLATIONS 7
2. STATE-BY-STATE POPULATION AFFECTED BY MCL VIOLATIONS IN
GROUND-WATER DEPENDENT PUBLIC DRINKING WATER SYSTEMS 9
3. GROUND-WATER SYSTEMS WITH SPECIFIC MCL VIOLATIONS 10
4. MCL VIOLATIONS IN GROUND-WATER SYSTEMS BY CONTAMINANT 11
5. CONTAMINATION AT CERCLA SITES 14
6. POPULATION AFFECTED BY OFF-SITE CONTAMINATION 15
7. CONTAMINATION AT CERCLA SITES BY CONTAMINANT GROUP 17
8. CONTAMINATION AT RCRA SITES 18
9. CONTAMINATION AT RCRA SITES BY CONTAMINANT GROUP 19
10. NATIONWIDE FREQUENCY OF VOC DETECTION 22
11. NATIONWIDE CONCENTRATION OF VOCS DETECTED 24
12. CONCENTRATION DATA FOR SPECIFIC VOCS 25
13. GEOGRAPHIC PATTERN OF NITRATE LEVELS 30
14. STATE TRENDS IN COUNTY AVERAGE NITRATE LEVELS 32
15. USE INTENSITY OF SOLUBLE PESTICIDES 35
16. GROUND-WATER VULNERABILITY 37
17. POTENTIAL FOR GROUND-WATER CONTAMINATION 38
FROM PESTICIDE USE
18. PESTICIDES REVIEWED FOR REREGISTRATION 40
19. NEW PESTICIDE REGISTRATIONS 41
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ACKNOWLEDGMENTS
This document was prepared for the U. S. Environmental
Protection Agency, Office of Ground-Water Protection (OGWP),
under contract 68-01-7288. Caryle Miller of OGWP served as
Work Assignment Manager, with additional assistance provided by
Dr. Norbert Dee and Michele Zenon.
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EXECUTIVE SUMMARY
BACKGROUND
The Environmental Protection Agency's (EPA) Office of
Ground-Water Protection (OGWP) has developed a set of indicators
that the Agency and the States could use to track progress and
set priorities in ground-water protection efforts. This has been
part of a larger effort throughout EPA to identify indicators
that could be used to address environmental problems and to
determine program effectiveness in terms of environmental
results.
SELECTION OF INDICATORS
A three phase process was used to develop this set of
ground-water indicators. The first phase focused on a workshop
cosponsored by OGWP and the Office of Management Systems and
Evaluation. The two-day workshop gathered people from various
EPA Offices, other Federal agencies, state governments, public
interest groups, and technical organizations. The workshop
participants stressed a number of principles that should be
considered when choosing and verifying potential indicators,
including:
indicators should be based on actual data measurement;
indicators should lend themselves to graphic display to
convey trends and other information readily;
whenever possible, existing data should be used rather than
requiring new data collection;
ideally, data should be collected over time at the same
locations; and
data can have limitations and still be useful as an
"indicator" of ground-water problems or progress.
Following the workshop, a second phase was initiated by OGWP
to develop a preliminary list of indicators, conduct interviews
with a number of State, EPA, and Federal officials, and to
further refine the list. The last phase of activity consisted of
the pilot study. Indicators were developed to cover the
following areas of concern:
public drinking water supplies;
hazardous waste sites;
waste sites and industrial sites;
area-wide sources of contamination; and
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area-wide sources of potential pesticide contamination.
Brief descriptions of the chosen indicators follow. A more
detailed look at the specific measures is presented throughout
the document. A summary description of the objectives and
presentation of each indicator is included in Exhibit 1.
The indicators that have been developed to track progress
and trends in ground-water protection efforts can be used by the
States, where data are available, as part of their biennial
National Water Quality Inventory report to Congress under the
Clean Water Act, Section 305(b).
THE INDICATORS
Public Water Supplies
The indicator, maximum contaminant level (MCL), serves as a
measure of the quality of the ground water that is used for
public drinking water supplies, the effectiveness of ground-water
protection regulatory programs, and the population put at risk by
contaminated supplies. While this indicator does track "finished
water" it does give an indication of ground-water problems and
the effectiveness of ground-water regulatory programs.
Data for this indicator are available from the Federal
Reporting Data System (FRDS) which is maintained by EPA with data
collected by the individual states.
Hazardous Waste Sites
The level of contamination in and around hazardous waste
sites regulated under the Comprehensive Environmental Response,
Compensation and Liability Act (CERCLA) and Resource Conservation
and Recovery Act (RCRA) Subtitle C, provides an indication as to
the effectiveness of ground-water protection programs, the
potential risk to drinking water supplies and the population
served by those supplies.
Data for these indicators are available from the RCRA and
CERCLA site managers within a specific region. Survey forms,
which can be easily updated and modified to respond to new
informational requirements, were used to gather the data for this
pilot study.
Waste Sites and Industrial Sites
Volatile organic compounds (VOCs) were chosen to serve as an
indicator of ground-water contamination from industrial and
nonindustrial activity. The indicator also functions as a
surrogate for the detection of ground-water contamination by
other compounds. Data for the indicator used in the pilot study
came from ground-water samples which were taken in the vicinity
of waste sites on the National Priority List, and analyzed for
VOCs.
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Area-Wide Sources Generally
An indicator of area-wide contamination used in the pilot
study was the level of nitrates in ground water. Nitrate levels
reflect the presence of contamination from sources such as
agricultural activity and septic systems. There is an increasing
interest in area-wide sources of ground-water contamination not
only because there are far larger areas potentially at risk from
these sources than from point sources, but also because ground
water is an important, if not primary, water supply in many such
areas.
Data for the pilot study were extracted from STORET, which
is used by many, but not all, States to store nitrate data.
Area-Wide Sources of Potential Pesticide Contamination
The potential degradation of the ground-water resource from
pesticide applications is a problem which impacts both
environmental regulatory policy and agricultural practices. The
following measures provide an indication of the threat posed by
the use of leachable pesticides in areas where the ground water
may be vulnerable:
the measure of pesticide usage in pounds of active
ingredient applied per square mile per year versus ground-
water vulnerability. Vulnerability can be a county-wide
value assigned by the DRASTIC vulnerability index or similar
source; and
the number of pesticide registrations and reregistrations
that have been modified to reflect ground-water concerns.
Data on pesticide usage and ground-water vulnerability can
be collected from individual states. The agricultural department
of the state will normally have information on pesticide usages
and the state's geological survey and/or environmental protection
agency should have ground-water vulnerability information. The
data on registration and reregistration of pesticides by EPA
comes from EPA's Office of Pesticide Programs.
The Pilot Study
A pilot study was performed in order to test the selected
indicators, to develop various presentation methods employing
charts and graphs, and to determine potential applications. The
data used for the pilot study were from existing data sources.
In some instances, data were utilized from two or three States,
and, for one indicator, an EPA Region. Factors to be considered
when working with these indicators and their corresponding data
were developed for each indicator.
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Exhibit 1
GROUND-WATERlNDICATOBSSUMMAR3rTABLE
PRESENTATION
Identify the degree to which ground-water based
water supply systems meet all applicable MCLs
Identify the size of the population at risk from
systems in violation
Provide an understanding of the geographic
distribution of populations potentially at risk
Identify the specific contaminants for which
systems are failing to meet the MCLs
Identify those contaminants which are responsible
for th° <"--°f«f number of MCL violations
PTTBTJr WATER SUPPLIES; MAXIMUM CONTAMINANT LEVEL VIOLATIONS
Percent of systems with MCL violations
Percent of population affected by MCL
violations
Percent of population affected by MCL violations
on a State-by-State basis
Specific MCL contaminants vs number of systems
Contaminant vs number of MCL violations
HAZARDOUS WASTE SITES: ON AND OFF-SITE CONTAMINATION
CERCLA sites with contamination on-site only, off-
Identify the number of CERCLA & RCRA sites
with ground-water contamination on-site
and off-site
Provide an indication of the risk posed by such
contamination to the population in the vicinity of
off-site contamination
Identify the relative frequency with which various
types of contaminants are responsible for ground-
water contamination at CERCLA & RCRA sites
site, or off-site and threatening drinking water
RCRA sites with no contamination, on-site only,
or off-site
0 Population affected by off-site contamination
Contamination at CERCLA sites by contaminant
group
0 Contamination at RCRA sites by contaminant
group
WASTE SITES AND INDUSTRIAL SITES- vni .ATTf.F. ORGANIC COMPOUNDS
Identify the frequency with which various VOCs
are found in ground water
Nationwide frequency of VOC detection
Nationwide concentration of VOCs detected
Distribution of measured concentration for
ic VOCs
AREA-WIDE SOURCES GJEiW.llAffJ.Yi NITRATES
Identify the pattern and level of ground-water
quality with respect to area-wide sources
throughout the country
Display the State-by-state trends over time in
area-wide quality of ground water
County-by-county average concentration versus
a given time span
Number of counties, State-by-state, in which
nitrate levels hi ground water are improving
versus those in which they are worsening
AREA-WIDE SOURCES OF POTENTIAL PESTICIDE CONTAMINATION; PESTICIDE USE
i Identify the relative intensity of pesticide use on
a county-by-county basis
i Identify the relative vulnerability to ground-water
contamination on a county-by-county basis
i Provide an indication of where potential ground-
water problems from pesticide use might occur,
based on geographic patterns of use and
vulnerability
i Measure the regulatory activity that has
addressed ground-water concerns
Pounds of ingredient applied per square mile
per year
Vulnerability SCOrC aCTOSS counties
vulnerability map showing usage rates of
pesticides and vulnerability score
Number of pesticide registrations reviewed which
address ground-water concerns
Number of pesticide reregistrations that have
been reviewed for pound-water concerns
v
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I. INTRODUCTION
BACKGROUND
The protection and management of our nation's ground-water
resources is becoming an environmental priority at all levels of
government. Some States and Regions have been active in ground-
water protection for years and more than two dozen Federal
agencies and offices are presently involved in ground-water
related activities. In all areas of the country, the past decade
has brought a heightened awareness of the vulnerability of ground
water to threats from a myriad of sources.
In 1984, the Environmental Protection Agency (EPA)
established the Office of Ground-Water Protection (OGWP) as the
focus of ground-water policy coordination and planning for the
Agency. In the same year, the Agency published a Ground-Water
Protection Strategy which set forth the agency's goals and
policies in the area. OGWP is responsible for working with the
States to develop and implement state ground-water protection
strategies, for coordinating EPA ground-water policies and
guidelines, enhancing ground-water data management, and
initiating and conducting special studies of ground-water
contamination, among other tasks.
The development of indicators is one element of the Agency's
response to the overall priority that the Administrator has
placed on focusing EPA's programs to achieve maximum
environmental results. The Agency has been engaged in an effort
to identify indicators that could be used to track progress in
EPA's ground-water protection efforts.
INTRODUCTORY MATERIAL
This report presents a set of illustrations reflecting data
which can, in the future, serve as indicators of the condition of
the nation's ground water and of the progress the nation is
making in improving and protecting that resource.
It is important to note that this is not a final all-
inclusive list of ground-water indicators. A number of other
indicators, including one for underground storage tanks or
municipal landfills, may well be added to the program in the
future. A discussion of some of the indicators that were
considered but not included in this report is in Appendix A.
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The use of the indicators by EPA and other Federal and state
agencies will help answer two questions that are fundamental to
the country's ground-water protection programs:
what is the quality of our ground water with respect to
various potential threats?
how are we doing in our efforts to improve it...do the
trends indicate progress?
Managers can use indicators for two specific purposes:
assessing program progress and making management decisions
concerning future efforts and priorities in ground-water
protection; and
communicating results to the public.
Several states have expressed interest in using indicators
as part of the Clean Water Act, Section 305(b) reporting
requirements. Not all states have data readily available. EPA
encourages states to use the indicators, where data are
available, as part of the 305(b) reporting process.
STRUCTURE OF THE REPORT
The next chapter describes the process used to select the
indicators which are presented in this report. The following
five chapters each present the indicators chosen in one area of
concern related to ground water.
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II. SELECTION OF THE INDICATORS
This chapter describes the process that was used to select
the indicators that are presented later in this report.
Throughout the selection process, OGWP has worked closely with
EPA's Office of Management Systems and Evaluation which has
overall responsibility for indicators throughout the Agency.
OGWP has also received support and cooperation from other EPA
Program offices throughout the Agency which have ground-water
responsibilities.
THE 1986 WORKSHOP ON GROUND-WATER INDICATORS
The focal point for the early activities in identifying
potential indicators was a workshop held in 1986 to bring
together representatives of many of the organizations that deal
with ground-water programs and policy. The two-day program
gathered people from various EPA Offices, other Federal Agencies,
state governments, public interest groups, and technical
organizations.
The participants stressed a number of "principles" that they
felt EPA should use in finalizing a list of indicators. These
are:
indicators should be based on actual environmental data
measurement, rather than administrative actions, to the
greatest extent possible;
wherever possible, data should be utilized that is already
being collected for other purposes and little, or no, new
data collection should be required, although new ways of
analyzing or combining data may be required;
the ideal data sets for indicators are those that will be
collected repeatedly over time, preferably at the same
sites, in order to provide good trend information; and
data can have limitations and still be useful for the
purpose of serving as "indicators" of ground-water problems
or progress; the data standards are not as rigorous as they
are, for example, in enforcement settings.
These principles guided the efforts to identify specific
indicators.
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FIELD INTERVIEWS
Following the workshop, a menu of potential indicators was
developed and interviews were then conducted with a number of
State, Regional and Federal officials to further refine the list.
The list included potential measures in three key categories:
public water supplies, point sources of contamination, and area-
wide sources of contamination.
The interviews with EPA personnel centered, for the most
part, on the specific programs with which the individual was most
familiar. This included individuals from the Offices of
Management Systems and Evaluation, Drinking Water, Pesticides and
Toxic Substances, Solid Waste [covering both Superfund and
Resource Conservation and Recovery Act (RCRA) issues], and
Underground Storage Tanks.
Interviews with State and local officials took a broader
perspective and addressed the whole range of issues affecting the
indicator program. A complete list of the individuals contacted,
some of whom attended the workshop, and organizations contacted
is included in Appendix B.
Based on the criteria and principles that had been
established at the workshop the list of potential indicators was
streamlined. A key recommendation was, again, that the best
indicators would be those based on environmental, rather than
administrative, data. While agreeing that new field monitoring
or other raw data collection was infeasible for this purpose,
some people advised caution in utilizing data that was originally
collected for wholly different purposes.
In addition, a number of participants expressed support for
the idea of choosing indicators that would account for the
relative risk posed by the pollution problem. For example, if
maximum contaminant level (MCL) violations were to be used as a
potential indicator, then they should be presented in relation to
the population that is at risk, namely the population that is
served by the water system in violation.
THE PILOT STUDY
To test the selected indicators and develop sample charts
and graphs, a pilot study was initiated using existing data. The
results of the pilot study are presented in the later chapters of
this report.
Data for the pilot study was collected from sources that
either would be the ultimate sources, such as EPA's Federal
Reporting Data System (FRDS) database for drinking water quality
information, or from sources that are representative of what
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would ultimately be used, such as State-by-State information on
area-wide sources.
In some cases the data were taken from two or three States
(Iowa,, Louisiana, and Pennsylvania), or one EPA Region (Region
10). In other cases the data were national, but only fully
developed for a few sample contaminants out of a much larger
universe. Finally, in a few instances where data for different
time periods was not available, some hypothetical results are
shown for illustrative purposes.
The review of the final list focused on the following
questions:
do the data exist in an automated or easily accessible
fashion?
are they readily available?
are the data continuous?
do they show trends?
can the data be used to highlight problems in specific
geographic areas?
The indicators presented in the following chapters were
selected as best meeting these criteria. They are, for the
following areas of concern:
public water supplies: MCL violations by ground-water based
systems in relation to the population they serve;
hazardous waste sites: tracking the status of sites with
respect to on-site and off-site ground-water contamination
and the populations potentially affected;
waste sites and industrial sites: the frequency and level
of detection of volatile organic compound (VOC)
contamination in the vicinity of such sites;
area-wide sources: the levels of nitrates in ground water,
which are generally indicative of a broad range of
contaminants from agricultural activity or septic systems;
and
area-wide sources of potential contamination from
pesticides: tracking the amount of leachable pesticides
used in vulnerable hydrogeological settings; and one
administrative indicator, the number of pesticide
registrations that result in special labelling or other
restrictions because of ground-water considerations.
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III. PUBLIC WATER SUPPLIES
INTRODUCTION
The measure presented below addresses a number of questions
related to one of the most important uses of ground water: as
drinking water. It serves as an indicator of the quality of the
ground water that is used for public drinking water supplies, the
effectiveness of ground-water protection regulatory programs, and
the population put at risk by contaminated supplies. The
indicator provides the following information:
the number and proportion of ground-water based public
drinking water systems meeting applicable quality standards
and some indication of the degree of risk posed by those not
meeting the standards;
the geographic distribution of that risk across States; and
an indication and identification of the specific
contaminants that are responsible for that risk.
The indicator is the maximum contaminant level (MCL). A
measure of risk is provided by the population that is served by
public water systems that fail to meet all MCLs.
PRESENTATION OF THE INDICATOR
Percentage of Systems with MCL Violations (Figure 1}
Objective: to identify the degree to which ground-water
based water supply systems are meeting all applicable MCLs and
the size of the population that is at risk from those systems in
violation.
This graph shows the percentage of ground-water based
systems in the United States that had one or more MCL violations
during the last four years. In addition, the graph displays the
percentage of the population using ground water as its primary
source of drinking water that was served by those systems.
The time series displayed with this indicator allows for an
analysis of trends in both the percentage of systems and the
population served by systems reporting violations. For example,
the data presented in this graph (which are actual results) show
a steady decline, from 1984 through 1987, in both measures.
Since the percentage of systems with violations exceeds the
percentage of individuals served, it demonstrates that smaller
systems are responsible for a disproportionate share of the
reported violations.
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Figure 1
PERCENT OF DRINKING WATER SYSTEMS WITH MCL VIOLATIONS
% National Ground-Water Based Public Water Systems
% Population Affected
12.3
11.1
% Sys with Viol
% Pop Affected
1984
1985
1986
1987
Year
Data Source: FRDS
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State-bv-State Population Affected by MCL Violations (Figure 2)
Objective: to provide an understanding of the geographic
distribution of the populations potentially at risk by
contaminated ground water.
This national map illustrates by State:
1) the percentage of the population served by ground-water
based systems that reported one or more MCL violations in
the most recent year (1987). The map provides an indication
of the geographic distribution of the contamination data
presented in Figure 1.
2) State-by-State trends. The arrows shown on the map
indicate whether the affected population figure represents
an increase or decrease from the previous year.
For example, the chart shows that there is no strong
regional pattern to account for the States with the highest
percentage of population served by systems with MCL violations.
The eight States with the highest percentages are in six
different EPA Regions across the country.
Systems with Specific MCL Violations (Figure 3^
Objective: to identify the specific contaminants for which
ground-water based public drinking water systems are failing to
meet the MCLs.
This chart provides comparative information on the number of
violations for individual contaminants for each of the past two
years. The data presented are the number of ground-water based
public drinking water systems that reported the specific MCL
violations on one or more occasions.
This chart is valuable for two reasons. First, it allows
for a more detailed examination of the specific compounds that
seem to be causing the most frequent problems in the nation's
ground-water drinking supply. For example, three MCLs, bacteria,
nitrates, and fluoride, accounted for half of all violations in
1987.
Second, the year-to-year comparisons indicate whether, and
by how much, violations are increasing or decreasing for specific
compounds.
MCL Violations by Contaminant (Figure 4^
Objective: to identify those contaminants which were
responsible for the greatest number of MCL violations.
Similar to Figure 3, this chart shows the total number of
violations for the 22 chemicals in the past two years. By
including multiple violations for individual systems, these data
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Figure 2
STATE-BY-STATE POPULATION* AFFECTED BY MCL VIOLATIONS IN
GROUND-WATER DEPENDENT PUBLIC DRINKING WATER SYSTEMS
1987
Indicates a greater % of the relevant
population is affected in 1987 than in
1986
% Population* Served by Ground-Water
Wells Containing MCL Violations in 1987
03 - o.OO to 5.00
U - 5.00 to 10.00
^ 10.00 to 15.00
@ - 15.00 to 20.00
- 20.00 to 35.00
Indicates a smaller % of the relevant
population is affected in 1987 than
in 1986
Includes only the population which relies
on ground water as its primary
source of drinking water
Data Source: FRDS
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Figure 3
GROUND-WATER SYSTEMS WITH SPECIFIC MCL VIOLATIONS
Public Drinking Water Supply Systems
beta particle a
combined radium
gross alpha(l)
2,4,5-tp siivex
2,4-D
toxaphene
methoxychlor
lindane
endrin
Bacti
4810
5053
Public Water Supply (2)
Number of Public Ground-Water Supplies with MCL Violations
(1) Gross alpha particle activity excluding radium and uranium
(2) In 1986, of the 46,319 community, active, ground-water
systems reporting, 5,683 had 1 or more MCL violation(s).
In 1987, of the 46,743 community, active, ground-water
systems reporting, 5,209 had one or more MCL violation(s).
Data Source: FRDS
10
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Figure 4
MCL VIOLATIONS IN GROUND-WATER SYSTEMS BY CONTAMINANT
Public Drinking Water Systems
beta particle a
combined radium
gross alpha(l)
2,4,5-tp silvex
2,4-D
toxaphene
methoxychlor
lindane
endrin
Bacti
MCL Violations (2)
1,1231
11836
1000
1500
2000
Number of MCL Violations
(1) Gross alpha particle activity excluding radium and uranium
(2) In 1986, of the 46,319 community, active, ground-water
systems reporting, 5,683 had 1 or more MCL violation(s).
In 1987, of the 46,743 community, active, ground-water
systems reporting, 5,209 had one or more MCL violation(s).
Data Source: ERDS
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indicate the relative persistence of the different types of
violations.
DATA AVAILABILITY
Data for this indicator come from the FRDS database,
maintained by the EPA. The data on MCL violations are collected
by public water utilities and reported to the States per
regulations stemming from the Safe Drinking Water Act. The
States then provide the information to the EPA Regional Offices
which enter the data into the FRDS system.
The database can be accessed by the States or EPA at very
low cost, has good interactive capabilities, and supports various
graphing packages. The data can be sorted and displayed by well
type, contaminant type, population served, or in other ways.
Data on the actual contaminant levels found in water
supplies are not universally available to the FRDS system.
States are required to report violations, but not the specific
contaminant levels to the EPA Regional office. Still, in
approximately 40% of the cases, the concentration information is
supplied to the database.
CAVEATS
Some special aspects of the data should be understood when
interpreting this indicator:
Monitoring results from the drinking water program, in many
instances, measure "finished water" rather than the quality
of raw ground water. However, many ground-water based
systems utilize minimal, if any, treatment methods for
anthropogenic contamination;
The data may be collected in differing monitoring cycles for
different MCLs. Accordingly, all pollutants may not be
monitored for or reported with equal frequency. Some, in
fact, are not monitored annually, so year-to-year
comparisons may be difficult. In addition, not all
standards apply to all systems, standards do change,
additional MCLs are added over time; and
Information on turbidity violations is not included since it
does not reflect the presence or absence of specific
contaminants in the ground water.
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IV. HAZARDOUS WASTE SITES
INTRODUCTION
One of the major environmental hazards from abandoned and
active waste sites is the contamination of ground water. The
measure presented below will serve as an indicator of the level
of protection of ground water around these sites, and the
potential risk to drinking water supplies and to the population
served by those supplies. The indicator provides the following
information:
the number of Comprehensive Environmental Response,
Compensation and Liability Act (CERCLA) and RCRA sites with
ground-water contamination on- and off-site;
some indication of the risk posed by such contamination in
terms of the population in the vicinity of the sites with
off-site contamination; and
an indication of the types of contaminants found at the RCRA
and CERCLA facilities.
PRESENTATION OF THE INDICATOR
Contamination at CERCLA Sites (Figure 5^
Objective: to identify the degree to which ground-water
contamination has migrated from CERCLA sites. For purposes of
this presentation, "off-site" is the area beyond the specific
boundaries defined in the administrative order or the court order
which established the site.
The graph shows the number of sites on the National Priority
List (NPL) with ground-water contamination only at the site, the
number at which contamination has spread off-site, and the number
at which the contamination has reached drinking water supplies.
The time series that can be displayed using this indicator
will illustrate the impacts of corrective actions taken at the
NPL sites and the resulting decrease in the number of sites
showing continued off-site contamination. In the short term, the
number of sites will probably increase as more sites are added to
the NPL, as shown in the hypothetical data on the graph.
Population Affected by Off-Site Contamination (Figure 6)
Objective: to provide an indication of the risk posed by
the contamination from CERCLA sites in populated areas.
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Figure 5
CONTAMINATION AT CERCLA SITES
Number
of Sites
Off-site DW
Off-site
On-site only
DW = drinking water
* hypothetical data
1987
1989
1991
Year
On-site/Off-site: Site boundries are considered to be
those defined within the administrative
or court order
Data Source: Illustrative data for one EPA Region.
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Figure 6
POPULATION AFFECTED BY OFF-SITE CONTAMINATION
CERCLA SITES
800000
600000
Population
400000 -
200000 -
Off-site DW
Off-site
DW = drinking water
* hypothetical data
1983*
1985 *
1987
Year
Off-site: Those who live within a 3 mile radius of sites with off-site contamination.
Off-site DW: Those who live within a 3 mile radius of sites with off-site contamination
whose public drinking water supply has been contaminated.
Data Source: Illustrative data for one EPA Region.
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This graph, which uses hypothetical data, shows the number
of individuals living within three miles of CERCLA sites which
have off-site ground-water contamination. The number of
individuals whose drinking water supply has been contaminated is
shaded separately.
This indicator can provide valuable information as to the
relative risk posed to individuals living near those sites.
Contamination at CERCLA Sites by Contaminant Group (Figure 7^
Objective: to identify the relative frequency with which
various types of contaminants are responsible for ground-water
contamination at CERCLA sites.
This chart shows the number of NPL sites at which ground-
water contamination for metals, pesticides, other organic
compounds, and polychlorinated biphenyls (PCBs) has been found.
The chart will allow for a more detailed examination of the
groups of compounds that seem to be causing the most frequent
problems at or near the hazardous waste sites. In addition, the
year-to-year comparisons indicate whether, and to what degree,
trends seem to emerge. Figure 7 shows actual data for 1987.
These data, for example, show that organics have been the most
frequent off-site contaminant at NPL sites.
Contamination at RCRA Sites (Figure 8^
Objective: to identify the degree to which ground-water
contamination occurs at and has migrated from land disposal sites
that can be regulated under Subtitle C of RCRA.
The graph shows hypothetical data for RCRA land disposal
sites including the number of sites with no ground-water
contamination, with contamination at the site, and the number at
which contamination has spread off-site. Unlike the CERCLA site
data, there is no information collected as to the number of sites
at which the contamination had spread to drinking water supplies.
The time series that can be displayed using this indicator
will illustrate the effectiveness of regulatory actions designed
to limit the impacts on ground water from these sites. Over time
as new sites are permitted, the total number of sites should
increase but one would expect to see a decline in those with
contamination and especially those with contamination leaving the
site.
Contamination at RCRA Sites by Contaminant Group f Figure 9)
Objective: to identify the frequency with which various
types of contaminants are responsible for ground-water
contamination at RCRA sites.
-------
Figure 7
CONTAMINATION AT CERCLA SITES BY CONTAMINANT GROUP
(41 total sites)
Metals
Other Organics
Pesticides
PCBs
3 on-site only
off-site
off-site DW
DW = drinking water
10
20
30
40
Number of Sites
On-site/Off-site: Site boundries are considered to be those defined within
the administrative or court order.
Data Source: Illustrative data for one EPA Region.
17
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Figure 8
CONTAMINATION AT RCRA SITES
50 -\
40 -
Number
of Sites
30 -
20
10 -
46 sites
1987
1989*
Year
1991*
Off-site
On-site Only
No Contain.
* hypothetical data
On-site/Off-site: Site boundries are considered to be
limits of the RCRA site.
Data Source: Illustrative data for one EPA Region.
18
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Figure 9
CONTAMINATION AT RCRA SITES BY CONTAMINANT GROUP
(36 sites illustrated)
Metals
Other Organics
Pesticides
PCBs
10
20
30
Number of Sites
Of the 46 total sites, 36 sites are illustrated. The
remaining 10 sites provided no relevant information and
were therefore omitted from the graph.
On-site/Off-site: Site boundries are considered to be
limits of the RCRA site.
Data Source: Illustrative data for one EPA Region.
19
-------
This chart shows the number of RCRA sites at which ground-
water contamination for metals, pesticides, other organic
compounds, and PCBs has been found.
As with the chart shown on CERCLA sites, this chart will
allow for a more detailed examination of the groups of compounds
that seem to be causing the most frequent problems at or near the
hazardous waste sites. In addition, the year-to-year comparisons
indicate whether, and to what degree, trends emerge. The pilot
data in the chart are actual data for 1987.
DATA AVAILABILITY
The data necessary to complete these tables are available
from the RCRA and CERCLA site managers within a specific Region.
For the results of this study, data were provided by Region 10 of
EPA. Individuals in the Region developed a survey form that was
used to obtain the information from the relevant site managers.
A copy of the form, including some recommended changes to
increase its utility, is attached as Appendix C.
There are a number of existing databases, including but not
limited to the Comprehensive Environmental Response, Compensation
and Liability Information System; Facilities Index System;
Storage and Retrieval of Water Quality Information; and the
Hazardous Waste Data Management System, which contain information
on hazardous waste sites. These databases may, in the future,
provide the information necessary for this indicator, but at the
present time the data are not stored or available in a manner
that would do so. Accordingly, the use of the survey forms,
which can be easily updated and modified to respond to new
informational requirements, should be encouraged. The data,
through the survey forms, are available at low cost, but the
quality of the information could be enhanced if additional time
and resources could be dedicated to its collection. Moreover,
additional staff time would be needed to check the data.
CAVEATS
Some factors to keep in mind when considering this data are:
while the data used in the tables (except for the
hypothetical values) do come from Region 10 surveys, they
are presented for purposes of illustrating the type of
information that could be obtained, rather than as an
accurate reflection of the current situation in
Region 10; and
in certain instances, information was not available for the
pilot study to determine whether, and to what extent, a
chemical had migrated off-site.
20
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V. WASTE SITES AND INDUSTRIAL SITES
INTRODUCTION
The indicator presented in this chapter is intended to
provide information across a broad range of activities that are
potentially threatening to ground water. These can include
landfills, hazardous waste sites, leaking underground storage
tanks, underground injection control wells, spills, industrial
sites generally, and other possible point sources.
This indicator can provide the following information:
the frequency with which point source contamination is
actually found in the testing that is done around industrial
and waste sites;
the average concentrations of individual contaminants that
are found in such testing; and
the pattern, or distribution, of those concentrations among
the samples taken.
The indicator used in this chapter is volatile organic
compounds (VOCs). VOCs serve as an indicator of ground-water
contamination from industrial and non-industrial activities.
This indicator also functions as a surrogate for the detection of
ground-water contamination by other compounds.
PRESENTATION OF THE INDICATOR
Nationwide Frequency of VOC Detection (Figure 10)
Objective: to identify the frequency with which various
contaminants are found in ground water when monitoring is
performed around waste sites and industrial sites.
Figure 10 displays the percentage of ground-water samples at
such sites nationwide that are found to contain VOCs. In
addition, the detection percentage is divided into those samples
in which the VOC levels were at quantifiable levels and those in
which they were too low to be quantified (labelled
"unquantifiable").
Figure 10 displays data for five VOCs out of 31 that were
monitored at approximately 500 CERCLA and RCRA Subtitle C and D
sites (i.e., hazardous and nonhazardous landfills) to illustrate
the indicator. The data show that the most frequently found VOC,
trichloroethene, was detected in over 30% of the ground-water
21
-------
Figure 10
NATIONWIDE FREQUENCY OF VOC DETECTION
CERCLA AND RCRA SUBTITLE C & D SITES
(pilot data shown for 5 compounds only)
cis,l,3-dichloroethene
vinyl chloride
trichloroethene
toluene
tetrachloroethene
chlorodibromomethane
dichlorodifluoromethane
fluorotrichloromethane
bromodichloromethane
bromoform
bromomethane
chlorome thane
methylene chloride
ethylbenzene
trans- 1,3-dichloropropeae
1,2-dichloropropane
1,2-trans-dichloroethene
1,1-dichloroethene
chloroform
2-chloroethylvinyl ether
chloroethane
1,1^,2-tetrachloroethane
1,1,2-trichloroethane
1,1-dichloroethane
1,1,1-trichloroethane
1,2-dichlorobenzene
chlorobenzene
carbon tetrachloride
benzene
acrylonitrile
acrolein
quantifiable
nnqnanfifiahlp.
0
10
20
30
40
% Samples Containing VOCs
Data Source: Lockheed/EMSL-LV Hazardous Waste Disposal Site Database,
based on approximately 500 site investigations.
22
-------
samples taken. It also shows that in all but approximately 4% of
the cases the concentrations were too small to be quantified.
Nationwide Concentrations of VOCs Detected (Figure 11)
Objective: to present the national average concentrations
of those VOCs which were detected at quantifiable levels near
waste sites.
This chart shows the average concentrations (mg/1) for each
of 31 VOCs. The averages are simple arithmetic averages for each
VOC of all the observations in which that VOC was detected at a
quantifiable level. This will highlight those individual VOCs
being released into ground water at high concentrations.
The pilot data for five VOCs, show that two substances,
tricholorethene and chloroform, were detected at average
concentrations that were approximately three or more times as
high as the other VOCs.
This information can be combined with other data such as
detection frequency, half-life, and potential to harm the
resource, to provide indications of relative risk presented by
the various VOCs.
Distribution, or Range, of Measured Concentrations (Figure 12)
Objective: to present information on the degree of
variation among the States regarding quantifiable concentrations
of individual VOCs.
This display is a series of three-chart sets, where each set
represents a specific VOC. The three charts in each set depict
the distribution of statewide minimum, average, and maximum
concentrations. The data in the charts are the numbers of States
in which the statewide statistic fell within the range shown.
The pilot data for chloroform indicate that the statewide
average concentration, where quantifiable, was in the 1 to 10
ug/1 range in 4 States, between 10 and 100 in 10 States, between
100 and 1000 in 10 States, and above that in 7 States. If the
testing procedure was repeated, this information would be useful
for trend analysis.
DATA AVAILABILITY
Data for the indicator in this chapter can come from ground-
water samples taken in the vicinity of waste sites and other
industrial sites and analyzed for VOCs. It is designed so
sampling every year at the same sites is not required. If enough
data are collected for different time periods, another chart
23
-------
Figure 11
NATIONWIDE CONCENTRATION OF VOCs DETECTED
CERCLA AND RCRA SUBTITLE C & D SITES
(pilot data shown for 5 compounds only)
cis,13-dichloroethene
vinyl chloride
trichloroethene
toluene
tetrachloroethene
chlorodibromomethane
dichlorodifluoromethane
fluorotrichloromethane
bromodichloromethane
bromoform
bromomethane
chloromethane
methylene chloride
ethylbenzene
trans- 1,3-dichloropropene
1,2-dichloropropane
1,2-trans-dichloroethene
1,1-dichloroethene
chloroform
2-chloroethylvinyl ether
chloroethane
1,1,2^-tetraciiloroethane
1,1,2-trichloroethane
1,1-dichloroethane
1,1,1-trichloroethane
1,2-dichlorobenzene
chlorobenzene
carbon tetrachloride
benzene
acryionitrile
acrolein
0
T
4
2 4 6
Sample Average of Individual VOCs (mg/1)
Data Source: LockheeoVEMSL-LV Hazardous Waste Disposal Site Database,
based on approximately 500 site investigations.
24
-------
Figure 12
CONCENTRATION DATA FOR SPECIFIC VOCs
CHLOROFORM
MINIMUM CONCENTRATION DATA POINTS
20 -
NUMBER
OF
STATES
10 -
n .
m
-------
Figure 12
CONCENTRATION DATA FOR SPECIFIC VOCs
1,1-DICHLOROETHENE
MINIMUM CONCENTRATION DATA POINTS
20 -
NUMBER
OF
STATES
10 H
0
ABCDEFGHI
LOGARITHMIC SCALE OF CONCENTRATION (UG/L)
AVERAGE CONCENTRATION DATA POINTS
20 -
NUMBER
OF
STATES
10 -
ABCDEFGHI
LOGARITHMIC SCALE OF CONCENTRATION (UG/L)
MAXIMUM CONCENTRATION DATA POINTS
20 -
NUMBER
OF
STATES
10 H
ABCDEFGHI
LOGARITHMIC SCALE OF CONCENTRATION (UG/L)
TRANS-1,2-DICHLOROETHENE
MINIMUM CONCENTRATION DATA POINTS
20 H
NUMBER
OF
STATES
10 H
0
\
ABCDEFGHI
LOGARITHMIC SCALE OF CONCENTRATION (UG/L
AVERAGE CONCENTRATION DATA POINTS
20 -
NUMBER
OF
STATES
10 H
0
ABCDEFGHI
LOGARITHMIC SCALE OF CONCENTRATION (UG/L)
MAXIMUM CONCENTRATION DATA POINTS
20 -
NUMBER
OF
STATES
10 ^
0
iiiyi
ABCDEFGHI
LOGARITHMIC SCALE OF CONCENTRATION (UG/
Data Source: Lockheed/EMSL-LV Hazardous Waste Disposal Site Database.
based on approximately 500 site investigations.
26
-------
Figure 12
CONCENTRATION DATA FOR SPECIFIC VOCs
TRICHLOROETHENE
MINIMUM CONCENTRATION DATA POINTS
NUMBER
OF
STATES
rm
I
\
£3~,
0
ABCDEFGHI
.OGARITHMIC SCALE OF CONCENTRATION (UG/L)
WERAGE CONCENTRATION DATA POINTS
20 -
WMBER
OF
STATES
W -i
ABCDEFGHI
.OGARITHMIC SCALE OF CONCENTRATION (UG/L)
/IAXIMUM CONCENTRATION DATA POINTS
20 -
UMBER
OF
*ATES
10 H
0
TETRACHLOROETHENE
MINIMUM CONCENTRATION DATA POINTS
20 -
NUMBER
OF
STATES
10 H
1
I
ABCDEFGHI
LOGARITHMIC SCALE OF CONCENTRATION (UG/L)
AVERAGE CONCENTRATION DATA POINTS
ABCDEFGHI
LOGARITHMIC SCALE OF CONCENTRATION (UG/L)
MAXIMUM CONCENTRATION DATA POINTS
ABCDEFGH I
)GARITHMIC SCALE OF CONCENTRATION (UG/L)
20 -
NUMBER
OF
STATES
10 H
0
Pis
:::
ABCDEFGHI
LOGARITHMIC SCALE OF CONCENTRATION (UG/L)
Data Source: Lockheed/EMSL-LV Hazardous Waste Disposal Site Database,
based on approximately 500 site investigations.
27
-------
could be developed to show the trends in VOC contamination over
time.
The pilot data in the charts were obtained from the
Lockheed/EMSL-LV Hazardous Waste Disposal Site Database which
contains information based on an examination of 500 CERCLA and
RCRA hazardous waste sites. The data, collected under contract
to EPA, provide a snapshot of the extent of VOC contamination
migrating from waste sites on a nationwide basis. The database
provides minimum, average, and maximum concentration levels for
each of the 31 VOCs, aggregated by State.
CAVEATS
Some special considerations to be kept in mind when
interpreting this indicator are:
VOCs are not all the same, so the same concentration of two
of them should not necessarily imply equal levels of
environmental or public risk;
the data for this indicator do not come from a random
sample. The sites selected for sampling were usually chosen
because they were considered high risk sites, so there is
probably a higher than average likelihood of detecting
ground-water contamination; and
the distributions of State VOC concentrations are expected
to be skewed somewhat to the right, because the upper
(right) end is unbounded but the lower end is bounded by the
detection level.
28
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VI. AREA-WIDE SOURCES GENERALLY
INTRODUCTION
The measures in this section address the degree to which the
nation's ground water is being protected from area-wide sources
of contamination, such as agricultural activity and septic
systems. There is an increasing interest in area-wide sources of
ground-water contamination not only because there are far larger
areas potentially at risk from these sources than from point
sources, but also because ground water is an important, if not
primary, water supply in many such areas.
The indicator presented below provides the following
information:
the geographic pattern of contamination from area-wide
sources, county-by-county across the U.S.; and
the trend over time, State-by-State, in terms of the number
of counties in which the level of such contamination is
declining, not changing or increasing.
The measure that is used as an indicator of area-wide
contamination is the level of nitrates in ground water. Nitrates
have been chosen because they are the most universal contaminant
found in areas that have experienced ground-water contamination
from area-wide sources such as agriculture and septic systems.
In addition, the presence of nitrates can often indicate the
possible presence of other contaminants.
PRESENTATION OF THE INDICATOR
Geographic Pattern of Nitrate Levels (Figure 13}
Objective: to identify the pattern and level of ground-
water quality with respect to area-wide sources throughout the
country.
This map of the United States shows the county-by-county
average nitrate concentrations (mg/1) in ground water for the
past ten years. Average concentrations over entire counties and
over several years have been used to provide a broad-based
indication of area-wide ground-water quality.
For the map in Figure 13, data are shown for three pilot
States to illustrate how the final indicator data will appear.
The map display permits both a comparison of county-level
variations and identification of absolute levels of average
29
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Figure 13
GEOGRAPHIC PATTERN OF NITRATE LEVELS
For the pilot map, counties were selected according to the
criteria listed below. On a nationwide basis, a single cut-off
criteria would be selected.
(PA: includes counties which reported more than 50 observations between 1977-1987)
(IA: includes counties which reported more than 20 observations between 1977-1987)
(LA: includes counties which reported more than 8 observations between 1977-1987)
-------
nitrate concentrations. The data appear to indicate that
counties in Pennsylvania have a greater variation among counties,
and higher absolute concentrations than do counties in Iowa.
State Trends in County Average Nitrate Levels (Figure 14)
Objective: to display the State-by-State trends over time
in area-wide quality of ground water.
This chart provides comparative information on the number of
counties, State-by-state, in which nitrate levels in ground water
are improving (i.e., decreasing nitrate levels) versus those in
which they are not decreasing.
The pilot data compare nitrate levels in 1977-1980 data with
1981-1986 data. While the pilot data in the chart are limited,
they appear to indicate that approximately one-third of the
counties in both Pennsylvania and Iowa are improving in nitrate
concentration levels in ground water.
DATA AVAILABILITY
The data for this indicator are available in STORET for many
States. Not all States currently utilize STORET, so there is no
single, uniform source for all the data for this indicator on a
nationwide basis.
As more States begin to store their data in STORET, this
limitation will diminish. However, specialized data collection
will probably be necessary for some States for an extended period
in order to provide these indicators on a complete nationwide
basis. Even within States the data may not be uniform. Iowa's
Department of Natural Resources, for example, has nitrate data in
three different data systems.
A second difficulty in obtaining the data on nitrates is
that they may be stored under a number of different parameter
codes. In STORET there are over 47 parameter codes for nitrate
information. Considerable time was spent identifying the five
codes which together accounted for over 85% of the nitrate data
in STORET for the three pilot States. They are nitrate dissolved
as N, nitrate total as N, nitrate total as N03, nitrate dissolved
as N03, and N.
For those States which do utilize STORET for ground-water
data, the database can be accessed on-line by the States or EPA
at very low cost.
31
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Figure 14
STATE TRENDS IN COUNTY AVERAGE NITRATE LEVELS
1977-1980 (4yrs) vs. 1981-1986 (6yrs)
DEGRADATION
# of counties /State
showing an increase
in nitrates during the
last six years
15
1 C
21
Alaska
Alabama
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Dist. of Columbia
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
IMPROVEMENT
# of counties /State
showing a decrease
in nitrates during the
last six years
13
-------
CAVEATS
Some factors to consider in using these data are:
It may not be possible to include all counties in each State
in this analysis, due to the paucity of data. For the three
States in the pilot only one-fourth to one-half of the
counties had sufficient data to be included;
In an effort to strive for meaningful averages of nitrate
levels in each county, data were only used for counties that
had some minimum number of sample observations. That
minimum level was varied for the pilot States, from eight
observations in Louisiana to 20 in Iowa and 50 in
Pennsylvania, in order to gather enough data points for
purposes of illustration. The higher the number of sample
observations, of course, the more accurate and reliable the
average figure is for the county; and
There is a limitation on the number of counties for which
trends can be identified on the second indicator chart.
This limitation is simply that there is inadequate data for
some counties for one or the other time period, even though
there may have been enough data overall for the first
indicator chart (the map). For the pilot States, counties
were excluded if there was only data from one of the two
time periods, if fewer than three observations were
available for either time period, or if the number of
observations was very large in one period and very small in
the other.
33
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VII. AREA-WIDE SOURCES OF POTENTIAL PESTICIDE CONTAMINATION
INTRODUCTION
The potential degradation of ground-water resources from
pesticide applications is a problem which impacts both
environmental regulatory policy and agricultural practices. In
rural areas, where pesticide usage is highest, large numbers of
individuals get their drinking water from ground-water sources.
The measures in this chapter will provide an indication of the
likely condition of ground water in agricultural areas.
The measures presented below serve as indicators of the
protection of ground water from the threat posed by the use of
leachable pesticides in areas where the ground water may be
vulnerable. A pesticide's leaching potential is greater relative
to another pesticide's leaching potential when that pesticide is
mobile and persistent in soil and water systems. The indicators
provide the following information:
the geographic patterns of leachable pesticide usage and
ground-water vulnerability, to show the patterns of
potential ground-water contamination by area; and
pesticide regulatory activities at the Federal level that
incorporate ground-water considerations.
The indicators are:
1) the measure of pesticide usage in pounds of active
ingredient applied per square mile per year versus ground-
water vulnerability. Vulnerability can be a county-wide
value assigned by the DRASTIC vulnerability index or similar
source.
2) the number of pesticide registrations and re-
registrations that have been modified to reflect ground-
water concerns.
PRESENTATION OF THE INDICATORS
For purposes of the pilot study, data for the vulnerability
indicator are presented for one of the states (Louisiana) to
reflect the type of data that is available and the way in which
it will be used. When fully implemented, these maps may be
nationwide maps with shading by county.
Use Intensity of Soluble Pesticides by County (Figure 15^
Objective: to identify the relative intensity of pesticide
use on a county-by-county basis.
34
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USE INTENSITY OF SOLUBLE PESTICIDES
LOUISIANA BY PARISH
LBS of ACTIVE INGREDIENT / YEAR
SQUARE MILE
0 TO 400
401 TO 1000
1001 TO 1430
Data Source: Resources for the Future
-------
This first map in the three-map series presents leachable
pesticide use on major crops. The graph shows the information in
terms of use intensity which is the total county-wide pesticide
use divided by the size of the county. For purposes of this
study, the intensity of use was divided into three groupings as
follows:
low intensity (0 - 400 Ibs of active ingredient/square
mile);
medium (401 - 1,000 Ibs of active ingredient/square mile);
and
high (1001 - 1,430 Ibs of active ingredient/square mile).
The pilot data in the map show data for 15 leachable
pesticides on 10 major crops in Louisiana. This map provides a
good indication of the relative intensity of the pesticide usage.
It is interesting to note the apparent higher level of use near
the Mississippi River.
Ground-Water Vulnerability by County (Figure 16)
Objective: to identify the relative vulnerability to
ground-water contamination of the counties.
This second map in the series shows county-wide estimates of
ground-water vulnerability. The specific estimates were
determined using a vulnerability index known as "DRASTIC." The
DRASTIC system assigns a vulnerability score to each county based
on seven hydrogeological factors: JDepth to the water table, Net
Recharge, Aquifer media, jSoil Media, Topography, Impact of the
Vadose Zone,and Hydraulic Conductivity of the aquifer. For
purposes of this map, the following classes were developed:
low vulnerability (DRASTIC score less than or equal to 102);
medium vulnerability (DRASTIC score between 103 and 142);
and
high vulnerability (DRASTIC score equal to or greater
than 143).
As with the pesticide usage data, this information provides
a good indication of those areas in the State that are relatively
more vulnerable to ground-water contamination than others.
Potential Ground-Water Contamination from Pesticide Use
(Figure 17)
Objective: to provide an indication of where potential
ground-water problems from pesticide use might occur, based on
the geographic patterns of use and vulnerability.
36
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Figure 16
GROUND-WATER VULNERABILITY
LOUISIANA BY PARISH
VULNERABILITY
SCORE
LOW
MEDIUM
HIGH
Data Source: Resources for the Future
-------
Figure 17
POTENTIAL FOR GROUND-WATER
CONTAMINATION FROM PESTICIDE USE
LOUISIANA BY PARISH
CO
00
MEDIUM VULNERABILITY, HIGH PESTICIDES
HIGH VULNERABILITY, MEDIUM PESTICIDES
HIGH VULNERABILITY, HIGH PESTICIDES
Data Source: Resources for the Future
-------
This map results from overlaying the two maps described
above to comprise a final vulnerability map. The areas of
highest potential contamination from pesticides are those with
high usage rates of leachable pesticides and also high ground-
water vulnerability scores. The specific shadings of different
combinations of usage rates and vulnerability scores could be
firmed up for the final charts.
The pilot data in the maps show the major areas of concern
in Louisiana to be those along with the Mississippi River where
pesticide usage was of medium intensity and ground-water
vulnerability is high.
Rereoistrations of Pesticides (Figure IB\
Objective: to monitor the trend in Federal regulatory
activity to reregister and require specific labelling or other
actions for leachable and non-leachable pesticides.
The Office of Pesticide Programs at EPA reviews the active
ingredients of pesticides that have to be reregistered. This
graph shows the results of that review since 1980. The data are
shown separately for leachable versus non-leachable pesticides,
since these two types of pesticides pose different degrees of
threat to ground water.
For both types, the chart shows the number of pesticides
acted upon, and the portion for which special labelling or other
restrictions were imposed due to ground-water considerations.
The pilot data indicate that EPA is increasing the number of
pesticide reviews. This means more pesticides are being reviewed
for ground-water effects, along with other factors. These data
also indicate that the majority of the leachable pesticides are
being required to carry special labelling or have other
restrictions with respect to ground water.
New Pesticides Reviewed for Registration in 1987 (Figure 19)
Objective: to monitor the trend in new pesticide
registration activity with respect to ground-water protection.
The graph shows the number of new pesticide registration
actions taken by EPA year-by-year, and the portion for which
special ground-water requirements were imposed. As in the
previous chart, leachable and non-leachable pesticides are shown
separately.
DATA AVAILABILITY
Data for these indicators come from two different sources.
The information for the three maps dealing with pesticide usage
and ground-water vulnerability was obtained from Resources for
the Future (RFF). Information for future studies may be
39
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Figure 18
PESTICIDES REVIEWED FOR REREGISTRATION
LEACHABLE
NONLEACHABLE
1987
1986
1985
1984
20
10
1983
1982
1981
1980
0 0
10
20
30
40
Cancelled
Labelled
No Restrictive Action
Note: All pesticides were evaluated for their potential to leach
Data Source: Office of Pesticide Programs
40
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Figure 19
NEW PESTICIDE REGISTRATIONS
LEACHABLE
NONLEACHABLE
YEAR
1987
1986
1985
1984
10
10
15
NO FIELD LEACHING STUDIES REQUIRED
FIELD LEACHING STUDIES REQUIRED
NOTE: All pesticides were evaluated for their
potential to leach
DATA SOURCE: Office of Pesticide Programs
41
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obtained from sources such as the agricultural department of each
State, that will often have information on pesticide usage in the
State, though it may take some effort and a few analytical
assumptions to break that down to the county level. The
information for the pilot study came from a Resources for the
Future study for 15 leachable pesticides.
The ground-water vulnerability information should normally
be available from a State's geological survey and/or
environmental agency. The characterization for the pilot study
relied upon results from the "DRASTIC" model for vulnerability,
but other sources can be used to determine vulnerability.
The data on registration and reregistration of pesticides by
EPA came from EPA's Office of Pesticide Programs.
CAVEATS
There are several considerations to be kept in mind while
interpreting the results of the indicators in this chapter:
Perhaps the most important one is the implicit assumption
that a pound of one pesticide (active ingredient) is the
same as a pound of another, as long as they are both
leachable;
The categorization of pesticide usage into high, medium, and
low groups, and the similar categorization of ground-water
vulnerabilities into three groups are somewhat arbitrary and
bear careful examination before full-scale application;
Likewise, the combinations of different pesticide use
categories with specific ground-water vulnerability
categories that are shaded differently on the third chart
are somewhat arbitrary and should be considered carefully
for a final application of the methodology; and
There is a clear and intended implication that non-leachable
pesticides are preferable from a ground-water perspective.
However, it should also be recognized that from a public
health perspective, the non-leachable pesticides may be fat-
soluble and may be less desirable in the food chain.
42
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APPENDIX A
INDICATORS REVIEWED BUT NOT CHOSEN
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THE ROAD NOT TAKEN
Indicators Reviewed but not Chosen for Final List
POTENTIAL ADDITIONAL INDICATORS
Throughout the course of this study, from the 1986 workshop
to the present time, a number of potential indicators have been
examined and, for one reason or another, not included in the
final list. A brief discussion of these other measures that were
reviewed but not included in the final report follows.
Underground Storage Tanks
One of the primary sources of ground-water pollution is
leaking underground storage tanks. Among the measures that were
proposed was an administrative measure which monitored the number
of double-walled or otherwise protected tanks that had replaced
existing steel tanks, the number of above-ground tanks that had
replaced the older steel tanks or even the number of States with
EPA Underground Storage Tank (UST) monitoring requirements.
While these measures would provide an indication as to the
implementation of the UST Program and the speed with which the
older tanks were being removed, they could not be related
directly with ground-water quality.
Moreover, and perhaps more importantly, there is no
centralized data or automated database from which to access this
type of information. Obtaining the data for the indicator would,
even if it were possible, be very costly, in terms of time and
money.
Non-Hazardous Waste Sites
Since the data on these sites are collected and maintained
at the State level, and the regulations affecting these
facilities vary so much among localities, it was not practical to
develop an indicator for these sites in this initial pilot
effort.
A State Ranking Indicator
As described briefly in the text, at the end of the initial
identification phase of the project, an indicator that would
provide a ranking of a State's progress in dealing with ground-
water issues had been proposed. A scoring system was proposed
that would evaluate state efforts according to a number of
criteria including:
the existence of a wellhead protection program;
whether the State had identified all its wells;
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the existence of a State-wide underground storage tank
program; and
the existence of a centralized database of ground-water
information.
While this initial survey would provide a general
understanding of the level of effort in different States with
regard to ground-water protection and would possibly highlight
new data sources, it would not provide any information as to the
actual status of the ground-water resource. Accordingly, it was
determined that this measure would not be included, at least at
this time, in the final list of indicators.
Private Drinking Water Supplies
At the time of the 1986 workshop, it was proposed that the
vast number of private wells be included in any comprehensive
indicator program. However, the scarcity of data on these wells,
and the huge costs, in both time and money, that would have to be
expended to obtain better data, made the inclusion of such an
indicator impractical.
REVISIONS TO PRESENT INDICATORS
Over the course of this investigation a number of various
ways to present indicators in the general categories were
rejected or put off at the present time. In general, data
collection for these was found to be unduly burdensome or
expensive or they were seen to be duplicative of the chosen
indicator. One of these, which has been postponed rather than
rejected, is described below.
For hazardous waste sites; an indicator based on the regulatory
status of the RCRA or CERCLA site in question.
At the 1986 workshop, it was suggested that, rather than
collecting specific data on the concentrations of the
contaminants in ground water, EPA could utilize the regulatory
systems already in place to identify sites in three stages of the
program. Each stage, of course, would have significantly
different implications for ground water. For RCRA sites, the
three stages of regulatory status proposed were: sites that had
detected contamination, those that were carrying out corrective
actions, and those in which remedial action had been completed.
A similar procedure could be established for CERCLA sites.
This information could in fact complement, but not replace,
the data that will be obtained from the site managers using the
survey forms described in the text.
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APPENDIX B
INDIVIDUALS AND ORGANIZATIONS INTERVIEWED
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INDIVIDUALS AND ORGANIZATIONS INTERVIEWED
General Contacts
Ed Anton
Kate Blow
Paul Campanella
Peter Truitt
Armando Carbonell
Curtis Harlin
Arnie Kuzmack
Gary Martin
Bill Mullen
Bob Rauscher
Richard Smith
John Voytek
Doug Yoder
Pesticides
David
Anderson
Nancy Andrews
Mary Brown
Dave Fege
Chuck Kent
Carol Stangle
California State Water Resource Control
Board
Office of Policy, Planning & Evaluation,
U.S. EPA
Office of Management & Systems
Evaluation, U.S. EPA
Office of Management & Systems
Evaluation, U.S. EPA
Cape Cod Planning and Economic
Development Commission
Environmental Engineering and Regulatory
Support, U.S. EPA
Office of Drinking Water, U.S. EPA
Ohio EPA
Region 10, U.S. EPA
Energy Resource Consultants
United States Geological Survey
Ohio Department of Natural Resources
Dade County Environmental Resource
Management
Reregistration
Special Review and
Division, OPP, U.S. EPA
Region 4, U.S. EPA
California Department of Food and
Agriculture
Office of Drinking Water, U.S. EPA
Special Review and Registration Division,
OPP, U.S. EPA
Office of Pesticides and Toxic
Substances, U.S. EPA
Waste Sites
Ken Jennings
Barry Nash
Paul Sidowski
D. Vaughn Wright
Jim Pittman
Craig Zamuda
Office of Waste Enforcement, U.S. EPA
Superfund, Region 6, U.S. EPA
Superfund, Region 6, U.S. EPA
RCRA, Region 6, U.S. EPA
Special Waste Branch, U.S. EPA
Superfund, U.S. EPA
Underground Storage Tanks
Dave O'Brien
Database Contacts
William Eckel
Ray Enyart
Duane Geuder
Chris Norman
Bob Small
Office of Pesticides and Toxic
Substances, U.S. EPA
Viar & Company
Office of Drinking Water, U.S. EPA
Contract Lab Programs Database, U.S.
Ground-Water Database (WY)
RCRA Enforcement Division
EPA
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APPENDIX C
SURVEY FORM FOR HAZARDOUS WASTE
SITE STATUS INFORMATION
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Appendix C
REGION 10 SURVEY SHEET
S
o
_o
0.
o
a
tO
_e
2
fa
u
I
ENVIRONMENTAL PROTECTION AGENCY REGION 10
ENVIRONMENTAL INDICATOR QUESTIONNAIRE
PROGRAM:
RCRA;
CERCLA
OTHER:
SITE LOCATION:
STATE:
CONCENTRATION
LEVEL STATUS
Enter the following values for
concentration:
0-unknown
1 - at or below detection limit
2 = above detection limit
3 - above level of concern
GROUND WATER
CONTAMINANTS
PCrTS:
PESTICIDES:
OTHER ORGAN1CS:
METALS:
CONVENTIONAL:
BACTERIA:
HAS THE PLUME BEEN DETECTED OFF-SITE?:
POPULATION POTENTIALLY AT RISK (3 mile radiiu):
IS CONTAMINATION REACHING DRINKING WATER WELLS?:
ACTUAL POPULATION AFFECTED:
we suggest adding a
question concerning the
regulatory status of the
site
a second concentration level
status column is necessary
in order to differentiate on-
site and off-site concentration
level status data
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