Water Quality: Inconsistent State Approaches Complicate Nation's
Efforts to Identify Its Most Polluted Waters (11-JAN-02,
GAO-02-186).
The Environmental Protection Agency (EPA) believes that more than
20,000 bodies of water throughout the country are too polluted to
meet water quality standards. States use different approaches to
identify impaired waters. This variation has led not only to
inconsistencies in the listing of impaired waters but also to
difficulties in identifying the total number of impaired waters
nationwide and the total number of total maximum daily loads
(TMDL) needed to bring such waters up to standards. Under the
Clean Water Act and its regulations, EPA has given the states
some flexibility to develop listing approaches that are tailored
to their circumstances. However, some of the approaches have no
appropriate scientific basis. States apply a range of quality
assurance procedures to ensure the quality of data used to make
impairment decisions. Although states have long used quality
assurance procedures for the data they collect directly, they
have become increasingly vigilant about applying such procedures
to data from other sources. Because of inconsistencies in states'
approaches to identifying impaired waters, the information in
EPA's database of impaired waters is of questionable reliability.
The number of impaired waters cannot be compared from one state
to the next, and EPA cannot reliably tally the number of TMDLs
that must be completed nationwide. EPA's database also distorts
the size of some of the states' impaired waters when they are
mapped on EPA's website.
-------------------------Indexing Terms-------------------------
REPORTNUM: GAO-02-186
ACCNO: A02657
TITLE: Water Quality: Inconsistent State Approaches Complicate
Nation's Efforts to Identify Its Most Polluted Waters
DATE: 01/11/2002
SUBJECT: Data integrity
Information resources management
Quality assurance
Water quality
Web sites
EPA National Water Quality Inventory
EPA TMDL Tracking System
EPA Total Maximum Daily Loads Program
EPA Watershed Assessment Tracking and
Environmental Results System
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GAO-02-186
GAO
Report to Congressional Requesters
January 2002
WATER QUALITY
Inconsistent State Approaches Complicate Nation's Efforts to Identify Its
Most Polluted Waters
GAO-02-186
Contents
Letter
Results in Brief
Background
States Use Varying Approaches to Identify Impaired Waters
States Use a Range of Quality Assurance Procedures
Reliability of EPA's Impaired Waters Database Limited by
Inconsistent Data Conclusions Recommendations for Executive Action Agency
Comments and Our Evaluation Scope and Methodology 1
2 4 5 22
27 29 30 30 32
Appendix I Status of States' Monitoring and Assessment of Their Waters
Appendix II Comments From the Department of the Interior
Appendix III GAO Contacts and Staff Acknowledgments 40
GAO Contacts 40 Staff Acknowledgments 40
Table Table 1: Percentage of States' Waters Monitored and Assessed
Figures
Figure 1: Key Steps in Identifying Impaired Waters 6 Figure 2: Types of
Monitoring and the Pollutants or Conditions That They Measure 10 Figure 3:
Percentage of States' Rivers and Streams Monitored and Assessed 12 Figure 4:
Percentage of States' Lakes, Reservoirs, and Ponds Monitored and Assessed 13
Figure 5: The Sabine River Between Texas and Louisiana 18
Figure 6: The Missouri River Between Nebraska and Iowa and Several Small
Streams on the Border of Nebraska and Kansas
Abbreviations
CALM Consolidated Assessment and Listing
Methodologies EPA Environmental Protection Agency PCB Polychlorinated
biphenyl TMDL Total maximum daily load USGS United States Geological Survey
WATERS Watershed Assessment, Tracking, and
Environmental Results
United States General Accounting Office Washington, DC 20548
January 11, 2002
The Honorable Don Young
Chairman, Committee on Transportation and Infrastructure
House of Representatives
The Honorable John J. Duncan, Jr.
Chairman, Subcommittee on Water Resources and Environment
Committee on Transportation and Infrastructure
House of Representatives
Although the precise number is not known, the Environmental Protection
Agency (EPA) believes that over 20,000 bodies of water throughout the
country are too polluted to meet water quality standards. Among the
primary concerns associated with these waters are human health
problems, caused either directly by coming into contact with
contaminated waters or indirectly through consumption of contaminated
fish. Under the Clean Water Act, states must identify bodies of water that
are not meeting applicable state water quality standards and submit a list
of those waters to the EPA, along with an explanation of the methodology
used to identify them. To bring these waters into compliance with the
standards, states are required to establish a pollutant "budget"-or a total
maximum daily load (TMDL)-for each pollutant causing a body of water
to be impaired. A TMDL is the maximum amount of a pollutant that can
enter into a body of water without exceeding the water quality standard
for a pollutant.
In March 2000, we reported that states have little of the information they
need to assess the quality of their waters and, in particular, to identify
those that are impaired-a particularly serious problem, given the
resources needed to address such impairments.1 Concerned about possible
inconsistencies in the way that states identify impaired waters and EPA
conveys information about such waters to the public, you asked us to (1)
identify and assess the effects of any differences in states' approaches to
identifying impaired waters, (2) determine how states ensure the quality of
data used to identify impaired waters, and (3) assess the reliability of the
information in EPA's database of impaired waters. To respond to your
1 Water Quality: Key EPA and State Decisions Limited by Inconsistent and
Incomplete Data (GAO/RCED-00-54, Mar. 15, 2000).
Results in Brief
questions, we analyzed written methodologies that all 50 states and the
District of Columbia submitted to EPA with their lists of impaired waters.
We also completed a telephone survey of water quality officials from 15
randomly selected states to obtain more detailed information about states'
processes for identifying impaired waters, identify the methods they use to
ensure the quality of data collected, and determine how accurately they
believe their state's water quality is reflected in information that EPA
provides to the public on the Internet. We also analyzed the EPA database
containing states' data on impaired waters and TMDLs.
The approaches used to identify impaired waters vary considerably among
states. Variation among the states stems from a combination of factors,
including differences in the (1) water quality standards (including
designated or beneficial uses and criteria) for determining which waters are
impaired; (2) types of monitoring practices used to ascertain whether these
standards are exceeded; (3) procedures used to assess water quality data to
make listing decisions; and (4) guidance EPA regions give on grounds for
removing waters from state lists of impaired waters. This variation leads
not only to inconsistencies in the listing of impaired waters but also to
difficulties in identifying the total number of impaired waters nationwide
and the total number of TMDLs that states say will be needed to bring such
waters up to standards. Of particular note, there have been numerous cases
in which neighboring states share a common body of water that is listed as
impaired by one state but not by the other. Under the Clean Water Act and
its regulations, EPA has provided some flexibility to states to develop
listing approaches that are appropriate to their ecological and other
conditions. However, some of the variations in approaches have no
appropriate scientific basis. EPA has published one set of guidance that it
believes will address some of these inconsistencies. It is also planning to
issue a second set of guidance to improve consistency among state approaches
and in state methodologies.
States apply a range of quality assurance procedures to ensure that data
used to make impairment decisions are of sufficient quality. In general, the
procedures vary in their rigor. While states have long used quality
assurance procedures for the data they collect directly, they have become
increasingly vigilant about applying such procedures to the data they use
from other sources. Because of the significant consequences of designating a
body of water as impaired, officials from all 15 states that we contacted
said that they examine data from other sources to determine quality-although
the level of quality assurance that the states apply varies. For example, we
identified seven states across the country that
have passed data integrity laws prescribing minimum data requirements, such
as the number of samples needed to make water quality determinations. EPA
officials told us that, overall, these states' efforts are an attempt to
increase the quality and credibility of their listing decisions. They
cautioned, however, that states should balance the need for quality with
EPA's requirement that they consider all readily available data to avoid
rejecting data that indicate an impairment could exist.
Owing, in part, to the inconsistencies in states' approaches to identifying
impaired waters, the information in EPA's database of impaired waters is of
questionable reliability. EPA has undertaken significant efforts to
integrate states' data and present it to the public over the Internet, but
the information it presents can be only as good as the information the
agency enters into the underlying database. Inconsistencies in the data that
states submit are compounded by the different ways that they submit data to
EPA for inclusion in the system. For example, some states submit lists that
count several small segments of a river or stream as individually impaired
waters, while other states submit lists that identify larger segments of a
river or stream as impaired. As a result, the numbers of impaired waters
cannot be compared from one state to the next and EPA cannot reliably tally
the number of TMDLs that must be completed nationwide. In addition, EPA's
database distorts the size of some of the states' impaired waters when they
are mapped on EPA's Web site. Less than one-third of the state water quality
officials that we interviewed told us that their state's water quality is
reflected "very" or "somewhat" accurately on the EPA Web site.
We are making recommendations to EPA aimed at increasing consistency in the
ways that states develop and make changes to their lists of impaired waters.
We are also recommending that EPA improve the way it characterizes
information on its Web site so that users more clearly understand the
limitations of the data presented. In commenting on a draft of the report,
EPA said that the recommendations were reasonable, and noted that the agency
has several initiatives under way to address some of the issues raised in
the report. We agree that EPA's initiatives will help to address some of our
recommendations. One of the initiatives, however, a key guidance document
called the Consolidated Assessment and Listing Methodologies guidance, has
not yet been issued. In addition, the EPA initiatives do not fully address
recommendations designed to promote greater consistency in how states remove
waters from their impaired waters lists, and how they list interstate
waters. Accordingly, we did not revise the recommendations contained in our
draft report. We also provided the draft to the Department of the Interior
for comment. The
Background
Department's December 13, 2001, letter said that the report covered a
complicated and detailed topic well (see app. II).
The primary objective of the Clean Water Act is to "restore and maintain the
chemical, physical, and biological integrity of the Nation's waters." As
authorized under the act, states have primary responsibility for
implementing programs to manage water quality. As a first step, states set
water quality standards to achieve designated (or beneficial) uses for
waters, such as recreational, agricultural, industrial, or other uses. These
standards are then used to determine whether the states' waters are
impaired, among other things.
In addition to establishing water quality standards, states are also
responsible for monitoring the quality of their waters, assessing all
readily available water quality data to determine whether the criteria for
particular waters are being met, and reporting on the quality of their
waters to EPA. Generally, to monitor water quality, states select the
rivers, lakes, and other waters for which they plan to collect data during a
specific period of time and collect water samples from them. After the data
are collected, the states analyze the data and compare the results to their
standards to assess whether the water bodies are meeting standards. In
assessing their waters, state agencies responsible for water quality
programs can also use data collected by other state agencies, federal
agencies, volunteer or academic groups, and other entities. For example, one
source used by many states is the U.S. Geological Survey (USGS) within the
Department of the Interior, which has a large program for monitoring water
quality. Under section 305(b) of the act, states are responsible for
reporting biennially on the quality of their waters, and EPA is responsible
for compiling these reports into the National Water Quality Inventory. As
part of this effort, EPA provides guidance to states on monitoring and
assessing their waters.
In addition to reporting on the overall quality of their waters, the Clean
Water Act requires states to identify waters that do not meet applicable
water quality standards. Specifically, section 303(d) of the act requires
states to list the waters within their state boundaries for which certain
technological controls required under the act are not stringent enough to
implement applicable standards. Under the act, EPA must approve the states'
lists. The 303(d) lists identify waters in which pollutants need to be
reduced. States are required to develop a TMDL for each of the pollutants
affecting each impaired body of water. Under the act, if states do not
establish TMDLs for impaired waters, EPA must do so.
While the states are primarily responsible for managing water quality, EPA
is responsible for developing regulations and guidance implementing the act.
In 1985, EPA issued water quality regulations requiring states to provide a
list of impaired waters.2 In 2000, EPA finalized major revisions to these
regulations that would have required the states to develop more
comprehensive lists of impaired waters and would have clarified the required
elements of a TMDL. However, Congress postponed implementation of these
revisions, in part because of widespread concerns among a variety of groups.
Because the regulations were in flux during 2000, EPA waived the requirement
for states to submit their lists that year; instead, states are required to
submit their next list by October 1, 2002. In October 2001, EPA further
postponed the effective date of the revised regulations to April 30, 2003.
Prior to that time, EPA plans to develop a second set of revised
regulations.
Concern over the impaired waters program has led to years of litigation
among states, EPA, and interest groups. Lawsuits in 38 states have resulted
in almost two dozen consent decrees requiring states to develop TMDLs or
requiring EPA to develop them if states fail to do so. At congressional
hearings in 2000, we and other organizations raised concerns over the
ability of states to gather the data needed to monitor their waters, and in
particular to support the identification of impaired waters needing TMDLs.
As a result of these concerns, Congress requested the National Academy of
Sciences' National Research Council to study the scientific basis for the
TMDL program. The council issued a report in June 2001 that expressed
support for the TMDL program but called for improvements in how impaired
waters are identified and how TMDLs are developed.3
While the general process that states follow to identify impaired waters is
similar, the specific approaches they use vary considerably among states.
Generally, the process involves establishing water quality standards,
gathering data on water quality through monitoring, and assessing the data
to determine whether the criteria and standards are being met or whether a
body of water is impaired (see fig. 1). If a state determines that a
previously listed body of water is no longer impaired, then it can seek
States Use Varying Approaches to Identify Impaired Waters
2 EPA revised these regulations in 1992 to make the list a biennial
requirement.
3 National Research Council, Assessing the TMDL Approach to Water Quality
Management (Washington, D.C.: National Academy Press, 2001).
EPA's approval to remove that body of water from its list. Variation in the
approaches that states use occurs at each step in the process and causes
inconsistencies in the listing of impaired waters. These inconsistencies are
particularly apparent in cases of interstate waters. EPA published one set
of guidance in November 2001 that it believes will address some of these
inconsistencies. It plans to issue a second set in early 2002 to address
other causes. However, EPA officials stated that the underlying causes of
inconsistent listings require long-term action.
Figure 1: Key Steps in Identifying Impaired Waters
Note: Not all waters are monitored and assessed each cycle.
Source: GAO analysis of EPA documents.
Water quality standards can vary significantly among states. Variations in
water quality standards arise from differences among states in two
components of the standard-setting process: (1) the identification of
designated (or beneficial) uses for a particular body of water and (2) the
development of water quality criteria to protect each use. According to EPA,
some of these variations are appropriately based on different ecological
conditions but others are not. For example, states with coastal
Water Quality Standards Are Often Inconsistent
Designated Uses
plains could appropriately have lower standards for dissolved oxygen than
states with high mountain streams. The agency also notes that other
variations are often not appropriate. Inappropriate variations may arise if
states with shared or immediately adjacent water bodies designate them for
different uses. For example, one may consider the water suitable for
swimming and therefore have more stringent water quality criteria, while a
neighboring state may consider the same water to be used for wading, which
requires less stringent criteria.
Designated uses are the beneficial uses established by states, based on
social and environmental factors that waters are intended to support. For
example, a water may be designated for use as a public water supply or to
support aquatic life, irrigation, or contact recreation. Officials in some
states said that the designated uses in their states are appropriate while
others did not. Of the 15 state officials that we interviewed, 8
acknowledged that designated uses in their states need to be revised. For
example, all waters in Virginia are designated for swimming even though some
of the waters are inaccessible and too shallow for swimming purposes. Other
waters in Virginia are impaired by bacteria from wildlife sources and cannot
achieve the primary contact use. As a result, these waters do not meet the
water quality standard set for them. In other states, in some cases where
designated uses are inappropriate and need revision, waters may be
considered impaired by natural water quality conditions. Yet, one state may
list such waters as impaired, while another might not. For example,
according to their 1998 303(d) listing methodologies, Arizona precludes the
listing of waters impaired by naturally-occurring conditions while
California includes such waters on its list.
One explanation for the problems with many designated uses is that states
established many of them en masse in the early 1970s in order to meet the
requirements of the Clean Water Act. States had 180 days to put designated
uses in place, and many used the highly general goals of the Clean Water
Act-fishable-swimmable waters-as their designated uses. In addition,
implementation of the act initially focused on installing controls on
individual point sources of pollution and little attention was paid to
whether overall water quality met specific standards.
Reflecting these concerns, the National Research Council's recent report
states that many designated uses are too broad and need to be refined in
order to incorporate the range of scientific data and social needs for water
quality. The Council's report recommended that states' designated uses
should be divided into several tiers to more adequately represent water
quality conditions and that water quality criteria should have a more
Water Quality Criteria
logical link to the designated use to sufficiently measure attainment.
According to responses from our 15-state survey, such a refinement in
states' designated uses and water quality criteria would most likely result
in different waters being listed.
Water quality criteria provide thresholds for determining whether bodies of
water can support their designated uses. As with designated uses, criteria
used by states vary and in many states need updating. Variation among states
is primarily caused by different states focusing on different pollutants,
mainly because of differences in water quality criteria. Illinois, for
example, has numeric water quality criteria for two pollutants- sediment and
nutrients-for which neighboring Indiana does not have numeric criteria. As a
result, Illinois listed 32 percent of its waters as impaired by sediment,
while Indiana listed none. Similarly, Illinois listed 22 percent of its
waters as impaired by nutrients, but Indiana listed less than 1 percent as
so impaired. In some instances, neighboring states may both have numeric
criteria for a given pollutant, but the criteria may differ significantly.
Connecticut and New York on the Long Island Sound have different criteria
for dissolved oxygen and, therefore, list the Sound differently.
States also vary in the extent to which they use narrative criteria versus
numeric criteria to make a listing determination. For example, Nevada
focuses its listing determinations on violations of numeric water quality
criteria. On the other hand, Massachusetts used narrative criteria to list
approximately one-third of its reported impairments because it felt that the
designated use was impaired. With the criteria, Massachusetts considered a
lake to be impaired (for swimming) if noxious aquatic plants covered over 50
percent of its area. Massachusetts' officials conceded that their narrative
criteria may not correctly identify when a lake is impaired for various
uses, and they are currently working on revising the water quality
standards.
Other states also discussed the need to revise criteria that are difficult
to use in identifying impairments. Officials in 14 of the 15 states
represented in our interviews believe that water quality criteria in their
states need to be revised. Their views are consistent with the National
Research Council, which noted in its report that criteria should be measured
by reasonably obtainable monitoring data and should be defined in terms of
magnitude, frequency, and duration. Some state officials mentioned that they
would like to switch their narrative criteria to numeric criteria to provide
a clearer threshold for demonstrating whether an impairment exists.
Officials indicating their water quality criteria need to be revised told us
that such revisions could change the waters states have listed and the
number of waters listed. The most common pollutants for which the state
officials we interviewed believe water quality criteria need to be revised
are nutrients,4 bacteria, sediment, dissolved oxygen, and metals. These five
pollutants have been found to be among the leading causes of impairment
nationwide.
Monitoring Practices Differ Significantly
Types of Monitoring
States use a variety of monitoring practices. In order to determine whether
water quality standards are being met, states monitor their waters by
collecting samples of water or other indicators such as sediment, fish, or
macroinvertebrates. To establish a monitoring system, states select which
water bodies to monitor and determine, based on their water quality
standards, the conditions for which they will sample and test. They also
determine how often to take samples. In addition to their own data, states
can use data from other sources such as universities, other federal and
state agencies, and volunteer groups. Variation in states' practices can be
seen in the types and comprehensiveness of each state's monitoring.
States monitor water quality conditions in three ways: chemical monitoring
is used to assess levels of dissolved oxygen, suspended sediments,
nutrients, metals, oils, and pesticides; physical monitoring is used to
assess general conditions such as temperature, flow, water color, and the
condition of stream banks and lake shores; and biological monitoring is used
to assess the abundance and variety of aquatic plant and animal life and the
ability of test organisms to survive in sample water (see fig. 2). USGS
officials recommend that states utilize all three types of monitoring to
help ensure that water quality conditions are adequately characterized. The
officials suggested that although biological indicators may be used to
identify the condition of the waters, physical and chemical factors such as
improving habitat or reducing discharges will be adjusted to achieve
biological goals. Similarly, the National Research Council reported that
biological indicators integrate the effects of multiple stressors over time
and space and recommended that they be used in conjunction with physical and
chemical criteria.
4 EPA issued guidance for numeric nutrient criteria in October 2001.
Wisconsin officials told us that the number of waters on their 303(d) list
would increase by approximately 10 percent if they switched to this guidance
from the narrative criteria they currently use.
Figure 2: Types of Monitoring and the Pollutants or Conditions That They
Measure
Source: GAO analysis and interpretation of EPA data.
States vary in their emphasis on these different types of monitoring. For
example, Illinois, Maine, and Ohio rely primarily on biological monitoring
while Texas and Utah rely on chemical and physical monitoring. A 1998 Ohio
study suggests how these divergent monitoring approaches may yield different
impairment determinations for waters.5 This study found that of 645 waters
monitored, 50 percent met chemical but not biological criteria. It also
showed that the number of impaired waters in the state increased from 9
percent of assessed waters in 1986 to 44 percent in 1988, and that the
increase was due primarily to the increased use of biological monitoring to
support numeric biologic criteria. Water quality managers in Utah stated
that they hope to increase biological and habitat monitoring depending on
available funding and it is probable that more impaired waters would be
identified and listed as a result.
In addition to differences in the types of monitoring that states perform,
states also differ in the emphasis that they place on various pollutants in
their monitoring programs. For example, according to Indiana officials,
Indiana conducts more bacteriological monitoring than bordering states, and
has consequently identified 13 percent of its impaired waters as impaired by
bacteriological pathogens. In comparison, neighboring Illinois and Ohio,
which conduct less bacteriological monitoring, have identified
5 Chris Yoder and Edward T. Rankin, "The Role of Biological Indicators in a
State Water Quality Management Process," Environmental Monitoring and
Assessment, vol. 51 (1998), pp. 61-88.
Comprehensiveness of Monitoring Programs
only 1 and 2 percent, respectively, of their impaired waters as impaired by
such pathogens.
States also vary in the comprehensiveness of their monitoring programs. In
1998, the percentage of rivers and streams monitored and assessed by states
ranged from 0 to 100 percent; 39 states had monitored and assessed under 50
percent of their rivers and streams. Similarly, the percentage of lakes,
reservoirs, and ponds monitored and assessed by states ranged from 0 to 100
percent; 18 states monitored and assessed less than 50 percent of these
waters (see figs. 3 and 4). Finally, several states that have estuaries and
ocean shorelines monitored and assessed 100 percent of these waters;
however, other states have not monitored and assessed these waters (see app.
I for a detailed list of the percentages by state). As we noted in our March
2000 report, state officials told us that more comprehensive monitoring
would have identified more impaired waters. In the 50-state survey conducted
for that report, just 18 states reported that they had a majority of the
data they needed to place assessed waters on their 303(d) list. Most
respondents said that increased monitoring of their state's waters would be
most helpful in improving their 303(d) lists.6
6Because monitoring all waters in a state is prohibitively expensive, states
generally choose sites to monitor either on a targeted basis or on a random
basis-called probability-based monitoring. Currently, many states use a
targeted approach to monitor their waters, which means that monitoring
points are selected judgmentally or for a purpose. The points can be placed
either in a fixed fashion or can be done by rotating basin, which involves
the state monitoring and assessing a portion of its watersheds each year in
a rotating fashion. With targeted sampling, unless complete coverage can be
achieved, the data cannot be used to draw conclusions about the extent to
which the state's entire inventory of waters is attaining water quality
standards. Probability-based monitoring involves placing monitoring points
in a statistically random pattern, which allows the state to reach
conclusions about the status of all its waters. EPA guidance encourages
states to incorporate probability-based monitoring into their monitoring
practices. Thirty states are experimenting with probability-based
assessments, with six states already using them. However, while the results
will provide a percentage of all waters in the state that exceed criteria,
probability monitoring does not identify the location of specific segments
of water that exceed criteria. Thus, both probability and targeted
monitoring are needed for 305(b) and 303(d) reporting.
Figure 3: Percentage of States' Rivers and Streams Monitored and Assessed
Source: EPA's 305(b) report for 1998.
Figure 4: Percentage of States' Lakes, Reservoirs, and Ponds Monitored and
Assessed
Source: EPA's 305(b) report for 1998.
States are required by regulation to assemble and evaluate "all existing and
readily available water quality-related data and information," including
data from external sources such as federal agencies, volunteer or academic
groups, and other entities. However, states vary in their use of these
sources of data. Officials we interviewed from 7 of the 15 states said that
they used external sources of data to a "moderate" extent and officials from
5 states said they use the sources to a "minor" or "very minor" extent. Most
state officials commented that external data and information
received, although not used to make listing determinations, triggered
follow-up monitoring by the state.
States Use Different Data Assessment Methods
Use of Monitored Versus Evaluated Data
Use of Fish Advisories to Make Impairment Decisions
After states collect data, they must have methods in place to assess the
data to determine whether waters are impaired. States vary widely in their
use of such assessment methods. The key differences that we found in states'
assessment methods were (1) the extent to which states make listing
determinations based on "monitored" versus "evaluated" data, (2) how states
use fish consumption advisories in making impairment decisions, and (3) how
states compare water quality data with water quality criteria in determining
whether waters meet standards.
According to EPA, monitored data are those that have been collected within
the past 5 years and are believed to accurately portray water quality
conditions. In contrast, evaluated data include monitored data that are more
than 5 years old, as well as other types of information such as land-use
data, predictive models, and other less precise indicators of water quality.
The extent to which states use evaluated versus monitored data varies. For
example, officials from 4 of the 15 states we contacted told us that at
least 20 percent of the waters they listed as impaired were based solely on
evaluative data, while officials in another 4 states explained that none of
their impairment listings were based solely on such data. States also vary
in how they define monitored data. According to our analysis of the 50
states' methodologies, some states considered data as "monitored data" only
if the data were collected within the past 5 years (as recommended by EPA),
while other states used a 7- to 10-year threshold.
States varied considerably in their reliance on fish consumption advisories
as a basis for listing impaired waters. In 1998, 47 states issued a fish
consumption advisory of some kind, according to EPA's National Listing of
Fish and Wildlife Consumption Advisories database. However, only 15 states
had waters that were listed as impaired because of a fish consumption
advisory, based on their 1998 303(d) list. Most of the other states either
chose not to list their waters as impaired or counted a fish advisory as a
single impairment for the entire state rather than counting each of the
state's affected waters. For example, Wisconsin issued 447 fish consumption
advisories for individual waters in 1998 and listed 307 waters as impaired
for a fish consumption advisory in their 1998 303(d) list. On the other
hand, Minnesota issued 825 fish consumption advisories for individual waters
in 1998 but listed no waters as impaired for a fish consumption advisory in
their 1998 303(d) list. EPA issued guidance on October 24, 2000, to help
remedy this inconsistency between states by
Methods to Determine Compliance With Water Quality Standards
recommending that a state list a body of water as impaired if a fish
consumption advisory shows that water quality standards are not being met.
States also vary widely in the methods they use to compare water quality
data with water quality standards to determine whether waters are impaired.
To determine whether water quality data demonstrate an impairment, states
need to compare the data to the appropriate criteria. For monitored data,
which may include multiple samples from one body of water, states decide how
many samples need to exceed the criterion for a particular pollutant before
that water is considered impaired. States vary both in the percentage of
samples exceeding water quality standards that are needed to consider a body
of water as impaired, and in the number of samples that need to be taken to
consider the sampling data as representative of actual conditions. For
example, as recommended by EPA, most states list waters as impaired by
conventional pollutants if 10 percent of the samples taken exceed water
quality standards. However, some states, such as Kansas and Nevada, list
waters as impaired only if the water quality standard is exceeded in more
than 25 percent of collected samples. In addition, some states require a
minimum data set of 10 samples, while other states, such as Nevada and
Arizona, require only 4 samples. Time frames within which the minimum number
of samples must be collected also vary. Wyoming requires 10 samples to be
collected over a 3-year period, while Nebraska requires 10 samples to be
collected over a 5-year period.
States Remove Waters From Their Lists for Various Reasons
The option for states to remove listed waters is important because, as EPA
and states acknowledge, in the past many waters were listed inappropriately.
The reasons vary. For example, officials in one state said that they
mistakenly assessed some waters against higher standards than necessary,
which resulted in a number of waters being placed inappropriately on their
303(d) list. In some cases, waters were listed initially on the basis of
little or no data. For example, officials from one state told us that about
half the waters on its 303(d) list were listed on the basis of evaluated
data. Upon additional monitoring of these waters, the state found that many
meet standards and should therefore be removed from the 303(d) list.
EPA regulations require states to demonstrate "good cause" before an
impaired water can be removed from a 303(d) list.7 Specifically, once a
water body is listed as impaired, it must remain on the list until a TMDL is
developed unless good cause is shown to remove it. According to the
regulations, good cause includes (1) new data showing improvement in the
water; (2) new information showing a flaw in the original impairment
decision; or (3) changes in technological conditions, such as the use of new
control equipment. Nonetheless, based on our analysis of the 50 states'
methodologies, states vary in their methods and justifications for delisting
waters. These findings were corroborated by our interviews with officials in
the 15 states we contacted, which demonstrated a widely diverse experience
in the delisting process. For example, officials in 11 of the 15 states
represented in our interviews cited a variety of reasons for delisting
waters, including their belief that some waters were incorrectly listed in
the first place; that the quality of some waters had improved; or that a
TMDL was established for the water, eliminating the need to keep it on the
303(d) list.
We found that EPA regions play a key role in advising states on delisting
matters. Some state officials told us that they had received guidance from
their EPA regional counterparts on how to remove waters from their lists,
while others reported receiving no such guidance. Moreover, the states that
did receive guidance from their regional EPA office were provided with
different "burdens of proof" before a body of water could be delisted. For
example, state officials in one region said that their region's policy
allowed them the flexibility to delist a water using the same method that
was used to list the water in the first place without new data. State
officials in another region, however, said that regardless of how a body of
water was originally listed, they could remove it only if they had new data
showing that the body of water was now meeting water quality standards.
Similarly, one region will allow states to remove waters that are not
meeting water quality standards but that have an EPA-approved TMDL in place.
Another region, however, will not support a delisting based only on an
approved TMDL.
States List Interstate Evidence of variability in water quality standards,
monitoring practices,
Waters Inconsistently assessment methods, and delisting methods is perhaps
most clearly illustrated when examining waters that cross state boundaries
or serve as
7 40 CFR 130.7 (b)(6)(iv).
a boundary between states. Interstate waters often lie in areas with similar
ecological conditions. Yet because of varying approaches by states in
identifying impairments, situations have arisen frequently in which one
state designates a body of water as impaired while another state does not,
or in which one state designates a body of water as impaired for a certain
pollutant while another state finds it impaired for a different pollutant.
EPA and the states have identified numerous inconsistencies of this kind.
Examples include the following:
* According to the 1998 303(d) list, Rhode Island lists the Abbot Run Brook,
which flows from Massachusetts into Rhode Island, as impaired to protect the
brook's designated use as a drinking water source. Massachusetts does not
list the brook because the state has not designated it for use as drinking
water-a more stringent designated use.
* The Rio Grande, which flows from New Mexico and then forms the border
between Mexico and Texas, is considered by Texas to be used for swimming-a
"primary" human contact-and, therefore, Texas has a stringent standard for
fecal coliform bacteria in the river. Texas currently lists the river as
impaired for this pollutant according to its 1998 303(d) list. New Mexico,
however, designates the river for wading-a "secondary" human contact. It
therefore uses a less stringent standard for fecal coliform bacteria, and
therefore does not list the river.
* The Sabine River along the border between Texas and Louisiana, south of
the Toledo Bend Reservoir, is listed by Texas as impaired for pathogens on
its 1998 303(d) list but not by Louisiana. The discrepancy is attributed to
a difference in water quality criteria for fecal coliform bacteria to meet
the contact recreation designated use as set in both states (see fig. 5).
Figure 5: The Sabine River Between Texas and Louisiana
Source: EPA.
* The Menominee River, which forms the boundary between the northeast corner
of Wisconsin and the southern tip of the Upper Peninsula of Michigan, is
included in Michigan's 1998 303(d) list as impaired because of dioxin,
pathogens, mercury, and a fish consumption advisory for polychlorinated
biphenyls (PCB). The river is listed for a fish consumption advisory for
mercury and PCBs in Wisconsin but it is not listed for dioxin or pathogens
because of differences in the timing of monitoring and the type of
monitoring conducted by the two states.
* Sugar Creek, flowing from North Carolina into South Carolina, is listed as
impaired for zinc in South Carolina but is not listed for zinc in North
Carolina according to the 1998 303(d) list. Both states have the same water
quality standard for zinc, but the pollutant was not identified in North
Carolina because it uses different monitoring practices than South Carolina.
* The Missouri River, along the border between Nebraska and Iowa, is listed
in the 1998 303(d) list as impaired for pathogens in Nebraska but not in
Iowa. Both states have the same primary contact recreation standard, but
Iowa made its determination based on data from one monitoring station while
Nebraska used data from multiple monitoring stations. On the other hand, the
river is listed as impaired for sediment in Iowa but not in Nebraska.
Neither state has a numeric criterion for sediment; hence, the difference in
interpretations has led to a difference between the two states (see fig. 6).
Figure 6: The Missouri River Between Nebraska and Iowa and Several Small
Streams on the Border of Nebraska and Kansas
Source: EPA.
* For several small streams on the border of Kansas and Nebraska, Kansas has
done more monitoring than Nebraska, which is in the process of developing
its monitoring network. As a result, Kansas has identified waters with
impairments, while Nebraska has not (see fig. 6).
Officials in 12 of the 15 states that we contacted told us they believe it
is "somewhat" or "very" important that states collaborate when making
listing decisions regarding cross-jurisdictional waters. At the same time,
officials from 10 of the states also told us that they have not collaborated
with neighboring states to make listing decisions, and officials from 5 of
the states reported that they do not plan to collaborate with neighboring
states in the future. According to a recent report by EPA's Office of
Inspector General, lack of collaboration between neighboring states was a
primary contributor to inconsistent interstate listings.
Importantly, officials in 13 of the 15 states that we contacted reported
that they have not received any guidance or assistance from EPA aimed at
increasing consistency in the way states list interstate waters. Most of the
states told us that they believe EPA should play a facilitator/mediator role
and help states work together to make listing decisions on interstate
waters. In connection with this, EPA officials noted that river basin
commissions may serve as a forum for resolving inconsistent interstate
listings. For example, the Delaware River Basin Commission, the Ohio River
Valley Water Sanitation Commission, and the Susquehanna River Basin
Commission have brought states together to discuss different approaches and
data.
EPA Has Recently Begun Efforts to Improve Consistency Among States
Integrated Water Quality Monitoring and Assessment Report Guidance
EPA and many states have acknowledged variations in states' listing
approaches and the consequent inconsistencies, while at the same time
recognizing that some level of state flexibility is appropriate in
developing standards, monitoring water quality, and performing assessments.
To improve consistency, EPA published one set of guidance in November 2001
and plans to issue a second set in early 2002. The first set is the 2002
Integrated Water Quality Monitoring and Assessment Report (Integrated
Listing) guidance and the second set is the Consolidated Assessment and
Listing Methodologies (CALM) guidance.
EPA's Integrated Listing guidance will merge existing guidance for
monitoring and assessing waters under section 305(b) of the Clean Water Act
and identifying impaired waters under section 303(d) and, according to EPA,
will result in a more comprehensive and consistent description of states'
waters, including impaired waters. States are currently required to provide
two separate lists of their impaired waters-one for EPA's National Water
Quality Inventory under section 305(b) and the other under section 303(d).
The lists in each case have been created for different purposes. In the case
of the inventory, the impaired waters are listed as part of a general effort
to characterize the condition of each state's and the
Consolidated Assessment and Listing Methodologies Guidance
nation's waters. The impaired water lists required under section 303(d) are
prepared for the more significant purpose of determining which waters need
TMDLs and potential remediation. In addition to the administrative burden of
submitting two separate lists, the divergent purposes of these lists have
led to inconsistencies between the two.
To address these inconsistencies, the Integrated Listing guidance will
create five categories in which states will rank their waters: (1) waters
that are attaining standards, (2) waters that are either meeting some
standards and are not threatened in other standards, or that do not have
enough information to list; (3) waters with insufficient data to make a
listing decision; (4) waters that are impaired or threatened for one or more
standards but for which a TMDL does not need to be developed;8 and (5)
waters that are impaired and need a TMDL. The guidance also recommends that
the states use the National Hydrography Dataset to geographically define and
reference their waters. The dataset provides comprehensive coverage of all
waters and allows for a common framework for all states to use in addressing
individual segments of waters across the United States.
EPA's proposed CALM guidance relies on state methodologies as a vehicle to
increase the consistency among state approaches in developing their lists.
The guidance contains "best practices" from state methodologies, such as
appropriate ways to document statistical approaches used to assess monitored
data or to document data quality considerations. In the short run, the CALM
guidance is intended to improve states' listing approaches by improving the
documentation of their water quality assessments and by making their listing
decisions more transparent. In the long run, the guidance is also expected
to result in more comprehensive and effective state water quality monitoring
programs. According to EPA officials, sharing best practices among states
increases the likelihood of states adopting similar approaches.
Our findings support EPA's assessment that state methodologies need to be
more thorough and that the states' decision-making processes should be more
transparent. States are required to include their methodologies for listing,
including a reason for any decision not to use existing and
8 Waters that are impaired but do not need a TMDL may include those for
which TMDLs have been completed and those for which the states plan
additional actions that will improve the waters.
States Use a Range of Quality Assurance Procedures
readily available data and a description of the methodology used to develop
the list, with their lists. However, we found that the 1998 methodologies
that the states submitted were inconsistent in the amount and type of
information provided. The methodologies ranged from a few pages that
generally explained state decision-making processes to much more
comprehensive documents detailing state monitoring practices and assessment
methods. According to EPA, encouraging states to disclose more about their
methods could help to alleviate inconsistencies in state listings by more
fully explaining sources of inconsistency.
States use a range of quality assurance procedures to ensure that the data
they use to assess their waters are valid. Most states have quality
assurance programs for their own monitoring efforts, which are generally
based on EPA guidance. In addition to the data that they generate themselves
to make listing decisions, states are required by regulation to consider
existing and readily available data from other sources, such as
universities, volunteer groups, and other state or federal agencies. In
doing so, states are relying increasingly on quality assurance requirements
to help ensure the accuracy and reliability of such external data. For
example, some states passed credible data or data integrity laws that
establish requirements for the quality or quantity of all data used to make
impairment decisions. EPA officials told us that increasing quality
assurance improves the reliability of the data on impaired waters, but they
cautioned that avoiding some data because of quality concerns could increase
the risk of not being able to identify some impaired waters.
Quality Assurance Programs Designed to Support Impairment Decisions
Quality assurance programs for environmental data are designed to provide
assurance that the data are of sufficient quality and quantity to support
impairment decisions. As recipients of EPA funding, states are required to
have both a quality management plan and quality assurance project plans to
help ensure the validity of impairment decisions. A quality management plan
is a management tool that documents an organization's system for planning,
implementing, documenting, and assessing its environmental data collection
and assessment methods. Within the overall plan, an organization develops
project-specific quality assurance project plans that serve as a "blueprint"
for data collection, handling, analysis, and management on that particular
project. EPA has guidelines for states to follow in designing both their
quality management plans and their project plans.
A key element of quality assurance for environmental data, including water
quality data, is the use of standard operating procedures for data
collection and analysis. Standard operating procedures involve specific
activities to manage a data collection project, collect and handle water
samples, analyze the samples, and manage the resulting database. These
procedures demonstrate that the data created and used by the states are
scientifically valid, legally defensible, and credible. For example, one
procedure to assure the integrity of the data is to have a "chain of
custody" for water samples, if a chemical analysis is to be undertaken. This
chain of custody is evidence that the water samples could not be tampered
with or tainted. Another example of a procedure to assure the quality of a
water sample is the calibration of testing instruments.
The use of standard sampling procedures, in particular, is important to
provide accurate data for impairment decisions. For example, because its
previous methods were determined to be inadequate, USGS developed stringent
procedures to sample for trace metals and EPA has recommended that these
procedures be used by states. However, according to USGS and EPA officials,
states have the flexibility to select their sampling and data analysis
procedures and not all states use the more stringent methods. According to
the officials, the stringent methods are more intensive and expensive and
could place a burden on state monitoring programs. According to USGS
officials, the purpose of its stringent procedures is to discover the
specific amounts of trace metals in a water body to depict current
conditions and allow for delineation of trends in water quality. On the
other hand, states may only need to know if their standards or criteria are
met, and those criteria levels may be much higher than the actual
concentrations measured by USGS methods. The officials also said that states
can use alternative procedures if they collect quality control data for
their water samples. Such quality control data include a variety of "blank"
tests, which are samples that can be used to identify whether any
contaminants are coming from the sampling equipment, such as the containers,
filters, and fixatives used to collect samples.
According to an EPA monitoring official, the most important and challenging
quality assurance issue that states face is the sufficiency of their
monitoring networks and the amount of data available to make impairment
decisions. For each water body sampled, states need to have a sufficient
number of samples to support an impairment decision. However, because of the
large number of waters that states need to monitor and the fact that the
waters need to be sampled several times, the states are often constrained in
the number of samples they can take for each one.
According to USGS officials, sampling is sometimes complicated by the need
to take samples at different times. Depending on the pollutant, water
samples need to be taken at various times of the day to reflect different
physical conditions in a water body. For example, dissolved oxygen
fluctuates naturally during a 24-hour cycle and as a result, samples taken
at different times of the day will likely provide different levels of
dissolved oxygen.
Water Quality Data Are Increasingly Subjected to Quality Assurance
Requirements
Data Gathered From External Sources
States have had quality assurance programs in place for their own data for
several years. As recipients of federal funds for water quality monitoring,
states are required to have such programs for their own data gathering
efforts. Officials in 14 of the 15 states represented in our interviews said
that they have procedures that must be followed during their own state
monitoring efforts. Officials from the remaining state said that much of its
work is contracted out or granted to groups that use quality assurance
steps. State officials said that their procedures were documented in manuals
and guidance. EPA officials stated that the states' efforts to increase
quality of data will result in more credible listings, but that states
should continue to consider existing and readily available data and be wary
of rejecting any data that may indicate that an impairment exists.
States are considerably more wary about the quality of the data that they
use from external sources. While states generally do not require external
groups to follow their own data collection procedures, they have become
increasingly concerned about the quality of data that external groups submit
and are therefore asking them to document their quality assurance
procedures. Officials from most of the 15 states contacted told us that they
attempt to assess the quality of the data presented from external sources.
Officials from eight states said they require that data from other sources
be accompanied by a quality assurance plan and that if no quality assurance
plan is submitted with the data, they do not use that data. Some other state
officials that we interviewed said that, while they do not require the
submission of a quality assurance plan or the use of specific collection
procedures, they do require the analysis of the samples to be done by a
state certified lab. Officials from one state mentioned that they are
comfortable with data obtained from either federal or other state agencies
because they are familiar with the agencies' data collection methods and
accept the data accordingly.
As a result of their concern over the quality of data, many states limit the
data they use from outside sources. Officials from 7 of the 15 states told
us that there are some sources of data that the state will not use to make
State Data Integrity Laws
Balancing Data Availability and Quality Control
listing determinations, including voluntarily collected data. The officials
in the remaining states said that they do not limit sources of data, but may
eliminate data that are not of sufficient quality for listing purposes.
Officials from 5 of the 15 states said that they use external data to a
"minor" or "very minor extent." For example, South Carolina makes most of
its impairment decisions based on its own state data, in part because it
does not receive much external data. Only three states use data from
external sources to a "great" or "very great" extent. For example, Georgia
accepts most external sources of data, including data from universities,
state and federal agencies, and local governments. Utah, through its
cooperative monitoring program with local, state, and federal entities, also
attempts to use many of the monitoring data provided by external sources.
Even when state officials decline to use data from external sources to make
listing decisions, they sometimes find it useful as a "trigger" for further
monitoring work. Officials from 8 of the 15 states said they use external
sources to identify potentially impaired areas in which to conduct future
state monitoring and assessment efforts.
In light of states' increased concerns over the quality of data used to make
important impairment decisions, we identified seven states nationwide that
have passed data integrity laws that establish requirements for the quality
or quantity of data used to make these decisions. Many states use EPA
guidance that provides that waters with 10 percent of the data showing an
exceedance of a criterion can be listed as impaired. After passing such a
law in 2000, Florida has since written state regulations providing that the
state should have at least 20 data points to make an impairment decision. In
addition, the regulations establish the number of exceedances that are
needed to declare a water impaired. For example, the regulations require
that at least 5 samples should exceed the water quality standard for a water
with 20 samples overall. Arizona's regulations require that state water
quality officials use only "reasonably current, credible, and scientifically
defensible data." Data are considered credible and scientifically defensible
if appropriate quality assurance and control procedures were used and
documented in collecting data. Virginia's law requires the state water
quality officials to consider reasonable data as data that are no older than
5 years. Wyoming's law requires the state to have three types of
data-chemical, physical, and biological-in order to list a body of water as
impaired.
EPA officials told us that, overall, the data quality improvements states
are seeking are appropriate. They cautioned, however, that the need for
quality must be balanced with the requirement under regulations to use all
readily available data as part of the assessment of water quality. Under
EPA's regulations for listing impaired waters, states are to consider all
readily available data as they assess the quality of their waters. However,
increasing standards of data quality may result in the rejection of some
data, with the risk that some impaired waters might not be identified. State
and EPA officials suggested that the preferred way to handle data that do
not meet quality assurance standards is to use the data as a trigger for
follow-up monitoring, as some states appear to be doing based on our
interviews. Furthermore, EPA and some state officials indicated that data
from external sources can extend the state's monitoring resources.
Accordingly, they have sought to establish guidance and training for
volunteer monitoring programs. For example, Massachusetts has developed
guidance for volunteer monitors and uses quality assured data gathered by
these groups along with its own data to make decisions about whether or not
waters are impaired and should be on the 303(d) list. Where data quality is
questionable, Massachusetts identifies the segment in its water quality
assessment reports for additional follow-up monitoring to confirm and
document the impairment.
The National Research Council report supports the idea of using
lower-quality data to identify states' monitoring needs. The report
addressed the issue of data quality by suggesting that a "preliminary list"
of waters be developed to report waters suspected of being impaired and
needing further monitoring. The Council states that in situations where
minimal data or evaluated data are available, the data may not be sufficient
for listing a body of water as impaired but may be valuable for identifying
potentially impaired waters. As noted previously, EPA's Integrated Listing
guidance incorporates the concept of different lists and also recommends
that states develop a monitoring strategy to deal with waters for which
sufficient data do not exist. Officials from two-thirds of the 15 states
that we interviewed agreed that such a list would be useful as a way to deal
with uncertain data. Officials from the remaining states cautioned that the
list may not be a good idea. One state said that it could be perceived as a
requirement to monitor the waters, which could create a burden on state
monitoring programs and resources.
Reliability of EPA's Impaired Waters Database Limited by Inconsistent Data
Owing, in part, to the inconsistencies in states' approaches to identifying
impaired waters, the information in EPA's database of impaired waters is of
questionable reliability. EPA has incorporated the states' data on impaired
waters into a large database and has recently made this information
available to policymakers and the public over the Internet. In addition to
the inconsistencies in the ways that states identify their waters as
impaired, there are inconsistencies in how states report critical
information to EPA for inclusion in the database. In some cases, EPA's
database and the information portrayed on its Web site contain inaccuracies.
One-third of state officials we interviewed said that EPA's Web site did not
portray their state's data accurately.
EPA has undertaken efforts to improve the public's access to information on
impaired waters nationwide by upgrading its Internet capabilities.
Specifically, EPA has used the data on impaired waters submitted by the
states to create a large database of information, called the TMDL Tracking
System, which is one of the databases used by the Watershed Assessment,
Tracking, and Environmental Results (WATERS) system. Both the TMDL database
and WATERS are used to convey information on EPA's Web site. The TMDL
database includes data related to states' listings, the causes of
impairment, court decisions related to the lists, TMDL schedules, and other
information necessary to understand the status of states' listings and TMDL
programs. The database can be used to generate summary reports on the
impaired waters of a state. The TMDL database is linked to WATERS, which
enables the data to be displayed on maps. WATERS unites water quality
information previously available only on individual state agency homepages
and in several EPA databases that support EPA's Web site. In the future, EPA
plans to include additional information, such as no discharge zones and
monitoring stations.
With any such system, the information presented can be only as good as the
data entered into the supporting database. Accordingly, inconsistencies in
the data submitted by states, as well as inaccurate data in some cases,
raise questions about the reliability of the TMDL database and of WATERS.9
Of greatest consequence, the variation in states' standards, monitoring,
assessment, and listing practices, as discussed previously, results in
inconsistencies in EPA's database. For example, the wide variation in
states' monitoring programs means that states have
9 Data are deemed to be "reliable " if they are sufficiently complete and
error free to be convincing for their purpose and context.
widely different bases upon which to make impairment decisions, resulting in
varying numbers of impaired waters among states. Such inconsistencies help
to explain why the numbers of waters identified as impaired by states range
from as low as 37 for one state but exceed 1,000 for several others. These
inconsistencies also make it difficult to aggregate data from individual
states into a national picture or to compare the quality of waters from one
state to the next.
Variations in how states report critical data to EPA for incorporation into
the TMDL database also undermine its reliability. Because states identify
the size of impaired waters differently, EPA's tally of both the total
number of impaired waters nationwide and the number of TMDLs that must be
established is not reliable. More specifically, some states submit lists
that count several small segments of a river or stream as individually
impaired waters, while others submit lists that count larger segments of a
river or stream as impaired. Illinois, for example, breaks the Mississippi
River into many segments, while Missouri breaks the Mississippi River into
three segments. As another example, Indiana's impaired water segments for
one river were reported separately by EPA for each impairment, while
Illinois' impaired water segments for the same river were listed once, with
all impairments noted under the single listing. As a result, according to an
Indiana water official, the state may therefore appear to have more impaired
water segments than it actually does. This variation may be alleviated by
EPA's Integrated Listing guidance. As recommended by the National Research
Council, the guidance encourages states to use one georeferencing system,
called the National Hydrography Dataset, to define the waters within their
borders.
Because states currently use a number of different ways to define their
waters, when EPA transfers their data into the WATERS system, errors may
result in the presentation of the information on the Web site. Overall, less
than one-third of the state water quality officials that we interviewed told
us that their state's water quality is reflected "somewhat" or "very"
accurately on the EPA Web site. A Connecticut water quality official
explained that the state's water quality is inaccurately reflected on EPA's
Web site as a result of a scaling problem. The official explained that while
there are waters in Connecticut that are impaired for very localized areas,
the EPA Web site depicts that impairment over a much larger area, thereby
overestimating the problem area and giving the public the sense that the
problem is bigger than it truly is. Similarly, Massachusetts uses
smaller-scale watersheds to identify impaired waters, and EPA uses
larger-scale watershed data. This results in the waters in Massachusetts
being listed at the aggregate level, thus inappropriately documenting the
geographical
Conclusions
extent of the problem. This oftentimes results in giving the sense of a
larger problem than the one conveyed by the state and will mask multiple
problems within a smaller geographical area. EPA officials said that the
agency attempts to present states' data as submitted to avoid
misrepresenting the information, and that the agency provides states with
the opportunity to review and revise the database information. They further
noted that this issue may be resolved by the states using the National
Hydrography Dataset.
States need some degree of flexibility in the way they list their impaired
waters to account for their particular ecological conditions and other
unique characteristics. Indeed, some flexibility in key listing-related
functions, such as the adoption of water quality standards and water quality
monitoring, is provided under both the Clean Water Act and EPA regulations.
However, flexibility currently exists beyond what is needed to address local
ecological characteristics or other differences. States have developed
varied approaches to setting water quality standards, monitoring water
quality, and assessing water quality data to make listing determinations.
States have also developed inconsistent methods and justifications for
removing waters from their lists, based in part, on inconsistent
interpretations of EPA guidance by EPA regions. Moreover, current EPA policy
has allowed wide disparities in how states describe their methodologies for
identifying and listing impaired waters.
The inconsistency in state approaches is most apparent in bodies of water
that are shared by neighboring states but which are often listed differently
by them. Such inconsistencies can engender doubt about the accuracy of the
listings and states' abilities to correctly identify impaired waters. If
states cannot correctly identify impaired waters, they cannot efficiently
channel efforts or resources to develop TMDLs for improving water quality.
While the problem of inconsistent interstate listings has been clearly
demonstrated, few states have received any guidance or assistance from EPA
on how to address it. Many have indicated that EPA can usefully serve as a
mediator and/or facilitator in helping states to work together in making
listing decisions on such waters.
In its regulatory role, EPA needs to be able to ascertain the nature and
extent of impairments on a national level and to provide a coherent picture
of water quality to policy makers and the public. Inconsistent state
approaches have undermined EPA's ability to provide such a picture. We
acknowledge the inherently difficult problems EPA faces in presenting an
accurate picture of states' impairment data, and its efforts to address
them. While EPA has undertaken significant efforts to convey information
about impaired waters over the Internet, this information is potentially
misleading in its current state and will be of limited value until EPA
improves the reliability of the data.
Recommendations for To provide greater consistency in the way states list
their impaired waters, we recommend that the Administrator, EPA,
Executive Action
*
*
* *
Agency Comments and Our Evaluation
provide additional guidance to the states on carrying out the key functions
(including standard-setting, water quality monitoring, and data
assessment) that influence how states identify the waters for their section
303(d) lists;
work with the agency's regional offices to ensure a more consistent
interpretation of the agency's policies on the criteria that states must
meet
to remove waters from their section 303(d) lists;
provide clear guidance to the states on the information they should use to
describe their methodologies for developing their section 303(d) lists; and
work with the states to help resolve discrepancies that arise in the listing
of interstate waters. In pursuing such a role, the agency could benefit from
the activities of the nation's river basin commissions, which are already
attempting to assist their states in making interstate listing decisions.
In addition, until EPA's Office of Water resolves problems relating to
inaccurate and/or misleading data contained in its WATERS database, we
recommend that the Administrator direct that office to explain clearly and
visibly to users of its impaired waters Web site the potential
misinterpretations that may arise from its current presentation of these
data.
We provided EPA and the Department of the Interior with a draft of this
report for review and comment. EPA did not submit a formal letter but did
provide comments from officials in the agency's Office of Water. Overall,
the officials said that our treatment of the issues raised in the report
accurately reflects discussions we have had with Office of Water officials
and that our recommendations are reasonable. The officials also described
initiatives under way that are germane to our recommendations
concerning the need to (1) increase greater consistency in how states list
their waters and (2) convey to users of EPA's impaired waters Web site the
potential misinterpretations that may arise from the site's current
presentation of listing data.
Regarding consistency of listings, EPA noted that it recently distributed to
the states and regions its 2002 Integrated Water Quality Monitoring and
Assessment Report guidance. EPA expects this guidance to reduce the
inconsistencies in state practices for monitoring their waters,
characterizing their water quality standards attainment status, and
identifying those waters requiring the establishment of TMDLs. EPA also
pointed out that the states' development of integrated reports will provide
a much clearer summary of the quality of the nation's waters. While we agree
that the integrated report will provide a useful summary of states' water
quality and will likely reduce inconsistencies in how they report on the
quality of their waters, we do not believe that the integrated reporting
guidance will help significantly in reducing inconsistencies in states'
approaches for identifying impaired waters. In particular, the guidance does
not address the key functions that most influence how states interpret their
water quality standards, monitor their waters, and assess the water quality
data used to identify impaired waters.
On the other hand, EPA's draft Consolidated Assessment and Listing
Methodologies guidance (CALM) has the potential to more directly address
sources of inconsistency. Specifically, the guidance seeks to encourage
states to improve their assessment and listing methodologies and, in the
longer term, strengthen their monitoring programs. The guidance also has the
potential to address inconsistencies in states' water quality monitoring and
assessment practices, and in how they describe their approaches through the
methodologies they submit to EPA along with their 303(d) lists. However, as
of December 2001, the CALM guidance had not yet been published.
EPA did not comment directly on our recommendation that it should work with
its regional offices to ensure a more consistent interpretation of the
agency's policies on removing waters from their 303(d) lists. We note,
however, that the need for consistent regional interpretation of the
agency's delisting guidance will grow significantly in the future under the
agency's new Integrated Listing guidance. Specifically, only the fifth of
five categories of waters in EPA's new categorization process is considered
to be the 303(d) list. EPA expects that states will transfer waters from
this category to other categories, with significant implications for which
state waters will be targeted for TMDL development. As such, it will be
essential that EPA's guidance on these decisions be interpreted consistently
from one region to another. EPA also did not comment directly on our
recommendation that it should work with states to help resolve discrepancies
that arise in the listing of interstate waters.
Regarding our recommendation concerning the potential misinterpretation by
users of listing information on EPA's impaired waters Web site, EPA noted
that it will continue to assist states in georeferencing their waters to
document impairments in a consistent manner and that it will continue to
update the WATERS database. In addition, EPA's Integrated Listing guidance
recommends that states use one standard format for physically defining all
of their waters. These efforts should help to increase the consistency of
reporting the size and number of impaired waters in future lists. However,
until the inconsistencies in states' approaches are resolved, the reporting
of impaired waters will continue to be highly variable. For this reason, we
continue to recommend that EPA explain to users the potential
misinterpretations that may arise from the current presentation of the data.
In its letter dated December 13, 2001, the Department of the Interior said
that our draft report "covered a complicated and detailed topic well" and
that "many of the contributing factors to inconsistent state perspectives on
water quality conditions are carefully identified . . . ." The letter
included a number of technical comments and suggestions from the
department's U.S. Geological Survey, which have been incorporated as
appropriate (see app. II).
To identify and assess the effects of any differences in states' approaches
to identifying impaired waters, we conducted a telephone survey of the state
officials responsible for developing such lists of impaired waters for 15
randomly selected states. We also reviewed and analyzed the written
methodologies that each of the 50 states and the District of Columbia
submitted to EPA. The methodologies are prepared by the states to explain
the methods they use to decide whether waters are impaired. In addition, we
identified several instances of waters that share state boundaries and
appeared to be inconsistently listed by the states. We discussed these
examples with EPA headquarters and regional officials to determine the
reasons for the apparently inconsistent listings.
To determine how states ensure the quality of the data used to identify
impaired waters, we first reviewed EPA's quality assurance guidance to
determine what is required of states. We included questions on the quality
assurance procedures that states use in our 15-state survey of state water
quality officials. We also interviewed appropriate officials at 9 of 10 EPA
regional offices to determine what procedures states in each region are
following to ensure the quality of the data used to create their lists.
Finally,
Scope and Methodology
we reviewed data credibility regulations written by two states and discussed
them with state and regional officials.
To assess the reliability of the information in EPA's database of impaired
waters, we took steps to determine the consistency, completeness, and
accuracy of this information. We reviewed EPA's guidance for preparing the
303(d) report and other EPA guidance relevant to the monitoring and
assessment of waters. We requested EPA to provide us specific data by state
and examined the data for completeness. To determine the accuracy of EPA's
WATERS Web site and other EPA sites based on the database, we requested the
officials who participated in our 15-state survey to look at their state
information and provide us with an assessment of how accurately the data
were portrayed. We also used the Web site to attempt to gather information
that would allow us to determine the nature and magnitude of the nation's
water quality problems, however, we were unable to do so. We discussed these
matters with EPA headquarters officials.
We conducted our work from April through November 2001 in accordance with
generally accepted government auditing standards.
As we agreed with your offices, unless you publicly announce the contents of
this report earlier, we plan no further distribution of it until 30 days
from the date of this letter. We will then send copies to appropriate
congressional committees and other interested parties and make copies
available to those who request them.
If you or your staff have any questions about this report, please call me or
Steve Elstein at (202) 512-3841. Key contributors to this report are listed
in
appendix III.
John B. Stephenson
Director, Natural Resources and Environment
Appendix I: Status of States' Monitoring and Assessment of Their Waters
States use a variety of monitoring practices and assessment methods; as a
result, the percentage of waters monitored and assessed across states varies
greatly. States report the percentage that they have monitored and assessed
for (1) rivers and streams; (2) lakes, reservoirs, and ponds; (3) estuaries;
and (4) ocean shorelines. Because rivers, streams, estuaries, and ocean
shorelines are reported in miles, while lakes, reservoirs, and ponds are
reported in acres, the percentage for each category is reported separately
below, in table 1.
Table 1: Percentage of States' Waters Monitored and Assessed
State
Percentage of rivers and streams assessed Percentage of lakes, reservoirs,
and ponds assessed
Percentage of estuaries assessed
Percentage of ocean shorelines assessed
Alabama 5 94 100
Alaska 0 0 1
Arizona 5 22 a a
Arkansas 10 69 a a
California 8 44 89
Colorado 27 36 a a
Connecticut 16 42 100
Delaware 95 94 4
District of Columbia 98 100 97 b
Florida 10 48 33
Georgia 12 94 100
Hawaii 100 0 100
Idaho 11 0 a a
Illinois 33 61 a a
Indiana 24 32 a a
Iowa 14 52 a a
Kansas 12 100 a a
Kentucky 19 96 a a
Louisiana 9 35 40 0
Maine 100 100 100 0
Maryland 39 27 98 100
Massachusetts 18 56 8 0
Michigan 40 55 a a
Minnesota 13 77 a a
Mississippi 47 58 28 55
Missouri 42 100 a a
Montana 10 94 a a
Nebraska 5 45 a a
Nevada 1 60 a a
New Hampshire 24 95 100 100
Appendix I: Status of States' Monitoring and Assessment of Their Waters
er" valign="middle"
>
Percentage lakes, Percentage Percentage and
of reservoirs, of of ponds
Percentage rivers ocean streams New New er" New gn="middle"
>North
of and estuariesshorelines Stateassessed assessedassessed assessedJersey 5944 100 Mexico 4 15a aYork 100100 100 Carolina 89 100100 Dakota 2297 aa Ohio10 0a aOklahoma 1457 aa Oregon47 9426 Pennsylvania 150 aa Island 54 75100 Carolina 6558 32 Dakota 32 18a aTennessee 88100 aa Texas7 50100 bUtah 1096 aa Vermont16 7a a
er" New gn="middle"
>North
aa
West Virginia 24 96
aa
Wisconsin 40 65
aa
Wyoming 87 0 aState does not have estuaries or ocean shorelines. bThis
information was not available. Source: EPA's 305(b) report for 1998.
Appendix II: Comments From the Department of the Interior
Appendix II: Comments From the Department of the Interior
Appendix II: Comments From the Department of the Interior
Appendix III: GAO Contacts and Staff Acknowledgments
GAO Contacts
Staff Acknowledgments
(360072)
John B. Stephenson (202) 512-3841 Steve Elstein (202) 512-6515
In addition to those named above, Aaron Alton, Susan E. Iott, Nathan A.
Morris, and Barbara L. Patterson made key contributions to this report. Also
contributing to this report were Nancy Crothers, Barbara Johnson, Karen
Keegan, Trish McClure, and Cynthia Norris.
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