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United States General Accounting Office: 
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: 

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: 

GAO Contacts: 

Staff Acknowledgments: 

Table: 

Table 1: Percentage of States’ Waters Monitored and Assessed: 

Figures: 

Figure 1: Key Steps in Identifying Impaired Waters: 

Figure 2: Types of Monitoring and the Pollutants or Conditions That 
They Measure: 

Figure 3: Percentage of States’ Rivers and Streams Monitored and 
Assessed: 

Figure 4: Percentage of States’ Lakes, Reservoirs, and Ponds Monitored 
and Assessed: 

Figure 5: The Sabine River Between Texas and Louisiana: 

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: 

[End of section] 

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.[Footnote 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 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. 

Results in Brief: 

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 Department’s December 13, 
2001, letter said that the report covered a complicated and detailed 
topic well (see app. II). 

Background: 

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.[Footnote 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.[Footnote 3] 

States Use Varying Approaches to Identify Impaired Waters: 

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 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: 

[Refer to PDF for image] 

This figure is an illustration of the key steps in identifying impaired 
waters, as follows: 

1) Establish water quality standards; 
2) Collect/access water quality data; 
3) Water Meets standards: 
* Yes: In water was on the 303(d) list, it can be removed; return to 
step 2; 
* No: 303(d) list; return to step 2. 

Note: Not all waters are monitored and assessed each cycle. 

Source: GAO analysis of EPA documents. 

[End of figure] 

Water Quality Standards Are Often Inconsistent: 

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 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: 

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 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: 

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,[Footnote 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: 

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. 

Types of 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 figure 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. 

Figure 2: Types of Monitoring and the Pollutants or Conditions That 
They Measure: 

[Refer to PDF for image] 

This figure illustrates the types of monitoring and the pollutants or 
conditions that they measure, as follows: 

Biological: 
Assesses: 
* structure and function of aquatic communities; 
* habitat, such as condition of riparian vegetation; 
* health and abundance of aquatic species or fish populations; 
* indicator bacteria. 

Physical: 
Measures: 
* temperature; 
* conductivity; 
* transparency; 
* total suspended solids; 
* flow. 

Chemical: 
Tests for levels of: 
* pesticides; 
* organics; 
* metals (cadmium, arsenic, etc.); 
* nutrients (phosphorous, nitrogen); 
* toxic materials in fish tissue; 
* dissolved oxygen. 

Source: GAO analysis and interpretation of EPA data. 

[End of figure] 

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. 
[Footnote 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 only 1 and 2 percent, 
respectively, of their impaired waters as impaired by such pathogens. 

Comprehensiveness of Monitoring Programs: 

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.[Footnote 6] 

Figure 3: Percentage of States’ Rivers and Streams Monitored and 
Assessed: 

[Refer to PDF for image] 

This figure is a map of the United States depicting the percentage of 
rivers and streams assessed in states as follows: 

80% to 100% (8): 
Delaware; 
Hawaii; 
Maine; 
New York; 
North Carolina; 
Tennessee; 
Washington; 
Wyoming. 

60% to 79%(1): 
South Carolina; 

40% to 59% (7): 
Michigan; 
Mississippi; 
Missouri; 
New Jersey; 
Oregon; 
Rhode Island; 
Wisconsin; 

20% to 39% (9): 
Colorado; 
Illinois; 
Indiana; 
Maryland; 
New Hampshire; 
North Dakota; 
South Dakota; 
Virginia; 
West Virginia; 

0 to 19% (25): 
Alabama; 
Alaska; 
Arizona; 
Arkansas; 
California; 
Connecticut; 
Florida; 
Georgia; 
Idaho; 
Iowa; 
Kansas; 
Kentucky; 
Louisiana; 
Massachusetts; 
Minnesota; 
Montana; 
Nebraska; 
Nevada; 
New Mexico; 
Ohio; 
Oklahoma; 
Pennsylvania; 
Texas; 
Utah; 
Vermont. 

Source: EPA’s 305(b) report for 1998. 

[End of figure] 

Figure 4: Percentage of States’ Lakes, Reservoirs, and Ponds Monitored 
and Assessed: 

[Refer to PDF for image] 

This figure is a map of the United States depicting the percentage of 
states’ lakes, reservoirs, and ponds monitored and assessed, as 
follows: 

80% to 100%: 
Alabama; 
Delaware; 
Georgia;
Kansas;
Kentucky; 
Maine; 
Missouri; 
Montana; 
New York; 
North Carolina; 
North Dakota; 
Oregon; 
Rhode Island; 
Tennessee; 
Utah; 
Virginia; 
West Virginia. 

60% to 79%: 
Arkansas; 
Nevada; 
Illinois; 
Minnesota; 
Wisconsin; 

40% to 59%: 
California; 
Connecticut; 
Florida; 
Louisiana; 
Maryland; 
Massachusetts; 
Mississippi; 
New Jersey; 
Oklahoma; 
South Carolina; 
Texas; 
Washington. 

20% to 29%: 
Arizona; 
Colorado; 
Indiana;
New Hampshire; 
South Dakota. 

0 to 19%: 
Alaska; 
Hawaii; 
Idaho; 
Iowa; 
Michigan; 
Nebraska; 
New Mexico; 
Ohio; 
Pennsylvania; 
Vermont; 
Wyoming. 

Source: EPA’s 305(b) report for 1998. 

[End of figure] 

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: 

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. 

Use of Monitored Versus Evaluated Data: 

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. 

Use of Fish Advisories to Make Impairment Decisions: 

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 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. 

Methods to Determine Compliance With Water Quality Standards: 

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.[Footnote 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 Waters Inconsistently: 

Evidence of variability in water quality standards, monitoring 
practices, assessment methods, and delisting methods is perhaps most 
clearly illustrated when examining waters that cross state boundaries 
or serve as 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 figure 5). 

Figure 5: The Figure 5: The Sabine River Between Texas and Louisiana: 

[Refer to PDF for image] 

This figure illustrates the Sabine River between Texas and Louisiana. 

Source: EPA. 

[End of figure] 

* 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 figure 6). 

Figure 6: The Missouri River Between Nebraska and Iowa and Several 
Small Streams on the Border of Nebraska and Kansas: 

[Refer to PDF for image] 

The figure illustrates the Missouri River between Nebraska and Iowa and 
several small streams on the border of Nebraska and Kansas. 

Source: EPA. 

[End of figure] 

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 figure 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: 
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. 

Integrated Water Quality Monitoring and Assessment Report 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 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;[Footnote 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. 

Consolidated Assessment and Listing Methodologies Guidance: 

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 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: 

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: 

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. 

Data Gathered From External Sources: 

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 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. 

State Data Integrity Laws: 

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. 

Balancing Data Availability and Quality Control: 

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.[Footnote 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 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 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. 

Conclusions: 

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 Executive Action: 

To provide greater consistency in the way states list their impaired 
waters, we recommend that the Administrator, EPA: 

* 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. 

Agency Comments and Our Evaluation: 

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 appendix II). 

Scope and Methodology: 

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, 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. 

Signed by: 

John B. Stephenson: 
Director, Natural Resources and Environment: 

[End of section] 

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: Alabama; 
Percentage of rivers and streams assessed: 5%; 
Percentage of lakes, reservoirs, and ponds assessed: 94%; 
Percentage of estuaries assessed: 100%; 
Percentage of ocean shorelines assessed: 15%. 

State: Alaska; 
Percentage of rivers and streams assessed: 0%; 
Percentage of lakes, reservoirs, and ponds assessed: 0%; 
Percentage of estuaries assessed: 1%; 
Percentage of ocean shorelines assessed: 0%. 

State: Arizona; 
Percentage of rivers and streams assessed: 5%; 
Percentage of lakes, reservoirs, and ponds assessed: 22%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Arkansas; 
Percentage of rivers and streams assessed: 10%; 
Percentage of lakes, reservoirs, and ponds assessed: 69%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: California; 
Percentage of rivers and streams assessed: 8%; 
Percentage of lakes, reservoirs, and ponds assessed: 44%; 
Percentage of estuaries assessed: 89%; 
Percentage of ocean shorelines assessed: 57%. 

State: Colorado; 
Percentage of rivers and streams assessed: 27%; 
Percentage of lakes, reservoirs, and ponds assessed: 36%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Connecticut; 
Percentage of rivers and streams assessed: 16%; 
Percentage of lakes, reservoirs, and ponds assessed: 42%; 
Percentage of estuaries assessed: 100%; 
Percentage of ocean shorelines assessed: 0. 

State: Delaware; 
Percentage of rivers and streams assessed: 95%; 
Percentage of lakes, reservoirs, and ponds assessed: 94%; 
Percentage of estuaries assessed: 4%; 
Percentage of ocean shorelines assessed: 100%. 

State: District of Columbia; 
Percentage of rivers and streams assessed: 98%; 
Percentage of lakes, reservoirs, and ponds assessed: 100%; 
Percentage of estuaries assessed: 97%; 
Percentage of ocean shorelines assessed: [B]. 

State: Florida; 
Percentage of rivers and streams assessed: 10%; 
Percentage of lakes, reservoirs, and ponds assessed: 48%; 
Percentage of estuaries assessed: 33%; 
Percentage of ocean shorelines assessed: 0. 

State: Georgia; 
Percentage of rivers and streams assessed: 12%; 
Percentage of lakes, reservoirs, and ponds assessed: 94%; 
Percentage of estuaries assessed: 100%; 
Percentage of ocean shorelines assessed: 0. 

State: Hawaii; 
Percentage of rivers and streams assessed: 100%; 
Percentage of lakes, reservoirs, and ponds assessed: 0%; 
Percentage of estuaries assessed: 100%; 
Percentage of ocean shorelines assessed: 84%. 

State: Idaho; 
Percentage of rivers and streams assessed: 11%; 
Percentage of lakes, reservoirs, and ponds assessed: 0%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Illinois; 
Percentage of rivers and streams assessed: 33%; 
Percentage of lakes, reservoirs, and ponds assessed: 61%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Indiana; 
Percentage of rivers and streams assessed: 24%; 
Percentage of lakes, reservoirs, and ponds assessed: 32%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Iowa; 
Percentage of rivers and streams assessed: 14%; 
Percentage of lakes, reservoirs, and ponds assessed: 52%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Kansas; 
Percentage of rivers and streams assessed: 12%; 
Percentage of lakes, reservoirs, and ponds assessed: 100%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Kentucky; 
Percentage of rivers and streams assessed: 19%; 
Percentage of lakes, reservoirs, and ponds assessed: 96%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Louisiana; 
Percentage of rivers and streams assessed: 9%; 
Percentage of lakes, reservoirs, and ponds assessed: 35%; 
Percentage of estuaries assessed: 40%; 
Percentage of ocean shorelines assessed: 0. 

State: Maine; 
Percentage of rivers and streams assessed: 100%; 
Percentage of lakes, reservoirs, and ponds assessed: 100%; 
Percentage of estuaries assessed: 100%; 
Percentage of ocean shorelines assessed: 0. 

State: Maryland; 
Percentage of rivers and streams assessed: 39%; 
Percentage of lakes, reservoirs, and ponds assessed: 27%; 
Percentage of estuaries assessed: 98%; 
Percentage of ocean shorelines assessed: 100%. 

State: Massachusetts; 
Percentage of rivers and streams assessed: 18%; 
Percentage of lakes, reservoirs, and ponds assessed: 56%; 
Percentage of estuaries assessed: 8%; 
Percentage of ocean shorelines assessed: 0. 

State: Michigan; 
Percentage of rivers and streams assessed: 40%; 
Percentage of lakes, reservoirs, and ponds assessed: 55%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Minnesota; 
Percentage of rivers and streams assessed: 13%; 
Percentage of lakes, reservoirs, and ponds assessed: 77%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Mississippi; 
Percentage of rivers and streams assessed: 47%; 
Percentage of lakes, reservoirs, and ponds assessed: 58%; 
Percentage of estuaries assessed: 28%; 
Percentage of ocean shorelines assessed: 55%. 

State: Missouri; 
Percentage of rivers and streams assessed: 42%; 
Percentage of lakes, reservoirs, and ponds assessed: 100%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Montana; 
Percentage of rivers and streams assessed: 10%; 
Percentage of lakes, reservoirs, and ponds assessed: 94%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Nebraska; 
Percentage of rivers and streams assessed: 5%; 
Percentage of lakes, reservoirs, and ponds assessed: 45%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Nevada; 
Percentage of rivers and streams assessed: 1%; 
Percentage of lakes, reservoirs, and ponds assessed: 60%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: New Hampshire; 
Percentage of rivers and streams assessed: 24%; 
Percentage of lakes, reservoirs, and ponds assessed: 95%; 
Percentage of estuaries assessed: 100%; 
Percentage of ocean shorelines assessed: 100%. 

State: New Jersey; 
Percentage of rivers and streams assessed: 59%; 
Percentage of lakes, reservoirs, and ponds assessed: 44%; 
Percentage of estuaries assessed: 100%; 
Percentage of ocean shorelines assessed: 100%. 

State: New Mexico; 
Percentage of rivers and streams assessed: 4%; 
Percentage of lakes, reservoirs, and ponds assessed: 15%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: New York; 
Percentage of rivers and streams assessed: 100%; 
Percentage of lakes, reservoirs, and ponds assessed: 100%; 
Percentage of estuaries assessed: 100%; 
Percentage of ocean shorelines assessed: 100%. 

State: North Carolina; 
Percentage of rivers and streams assessed: 89%; 
Percentage of lakes, reservoirs, and ponds assessed: 100%; 
Percentage of estuaries assessed: 100%; 
Percentage of ocean shorelines assessed: 0. 

State: North Dakota; 
Percentage of rivers and streams assessed: 22%; 
Percentage of lakes, reservoirs, and ponds assessed: 97%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Ohio; 
Percentage of rivers and streams assessed: 10%; 
Percentage of lakes, reservoirs, and ponds assessed: 0%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Oklahoma; 
Percentage of rivers and streams assessed: 14%; 
Percentage of lakes, reservoirs, and ponds assessed: 57%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Pennsylvania; 
Percentage of rivers and streams assessed: 15%; 
Percentage of lakes, reservoirs, and ponds assessed: 0%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Rhode Island; 
Percentage of rivers and streams assessed: 54%; 
Percentage of lakes, reservoirs, and ponds assessed: 75%; 
Percentage of estuaries assessed: 100%; 
Percentage of ocean shorelines assessed: 100%. 

State: South Carolina; 
Percentage of rivers and streams assessed: 65%; 
Percentage of lakes, reservoirs, and ponds assessed: 58%; 
Percentage of estuaries assessed: 32%; 
Percentage of ocean shorelines assessed: 0. 

State: South Dakota; 
Percentage of rivers and streams assessed: 32%; 
Percentage of lakes, reservoirs, and ponds assessed: 18%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Tennessee; 
Percentage of rivers and streams assessed: 88%; 
Percentage of lakes, reservoirs, and ponds assessed: 100%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Texas; 
Percentage of rivers and streams assessed: 7%; 
Percentage of lakes, reservoirs, and ponds assessed: 50%; 
Percentage of estuaries assessed: 100%; 
Percentage of ocean shorelines assessed: [B]. 

State: Utah; 
Percentage of rivers and streams assessed: 10%; 
Percentage of lakes, reservoirs, and ponds assessed: 96%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Vermont; 
Percentage of rivers and streams assessed: 16%; 
Percentage of lakes, reservoirs, and ponds assessed: 7%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Virginia; 
Percentage of rivers and streams assessed: 39%; 
Percentage of lakes, reservoirs, and ponds assessed: 93%; 
Percentage of estuaries assessed: 99%; 
Percentage of ocean shorelines assessed: 0. 

State: Washington; 
Percentage of rivers and streams assessed: 98%; 
Percentage of lakes, reservoirs, and ponds assessed: 53%; 
Percentage of estuaries assessed: 85%; 
Percentage of ocean shorelines assessed: 0. 

State: West Virginia; 
Percentage of rivers and streams assessed: 24%; 
Percentage of lakes, reservoirs, and ponds assessed: 96%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Wisconsin; 
Percentage of rivers and streams assessed: 40%; 
Percentage of lakes, reservoirs, and ponds assessed: 65%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

State: Wyoming; 
Percentage of rivers and streams assessed: 87%; 
Percentage of lakes, reservoirs, and ponds assessed: 0%; 
Percentage of estuaries assessed: [A];
Percentage of ocean shorelines assessed: [A]. 

[A] State does not have estuaries or ocean shorelines. 

[B] This information was not available. 

Source: EPA’s 305(b) report for 1998. 

[End of table] 

[End of section] 

Appendix II: Comments From the Department of the Interior: 

United States Department of the Interior: 
Office Of The Secretary: 
Washington, D.C. 20240: 
 
December 13, 2001: 

Mr. John B. Stephenson: 
Director, Natural Resources and Environment: 
United States General Accounting Office: 
Washington, D.C. 20548: 

Dear Mr. Stephenson: 

Secretary Norton provided me a copy of your draft report entitled, 
"Inconsistent State Approaches Complicate Nation's Efforts to Identify 
Its Most Polluted Waters" (GAO-02-186) to review. As you know, staff of 
the U.S. Geological Survey (USGS) were contacted by your office to 
provide information. 

While there are no recommendations for the USGS, the USGS staff has 
provided the following comments: 

Overall, we have found that you have covered a complicated and detailed 
topic well. Many of the contributing factors to inconsistent State 
perspectives on water-quality conditions are carefully identified, and 
examples are given to clarify what you have understood. We think this 
document will serve many of your readers well. 

We have some specific comments that we hope will help you further 
clarify the points you are making. 

Page 2: 

"Variation among the States stems from a combination of factors 
including differences in the (1) water quality standards for 
determining which waters...." All four of the points made are necessary 
to understand the inconsistency between States on water-quality 
conditions. One additional issue could be mentioned and that is the 
determination States make of what the specific beneficial uses are. 
Even if States use consistent methods for standards, monitoring, 
assessment, and get consistent guidance on removal of listed reaches, 
if they do not agree on the beneficial uses for water bodies, their 
conclusions on impairment will be different. You point out several 
examples (pages 17-19) where one State sees the water in the same river 
as a drinking water source another State does not, leading to different 
standards and perspectives. 

Page 4, Footnote #2: 

The note indicates that impaired waters that have or are expected to 
have technological controls in place to meet standards do not need a 
Total Maximum Daily Load (TMDL). If there is a time period over which 
the impaired waters are expected to meet standards, thus avoiding the 
need for a TMDL, please state what time frame is specified. 

Page 5: 

First full paragraph discusses when 303(d) lists were due (October 1, 
2002), but, in August 2001, the effective date was postponed, allowing 
18 months for public review of revised regulations. Is there a 
currently identified due date for the 303(d) lists? Will the new 
November 2001 guidance state what the due date is to be? 

Page 9: 

In the last paragraph: "USGS officials recommend that States utilize 
all three types of monitoring to help ensure that water quality 
conditions are adequately characterized." Consider adding: USGS 
officials suggested that, although the endpoint of monitoring for 
States may be the biological condition, if a State decides to obtain a 
different biological outcome than the one they find, a new biological 
condition will be obtained by adjusting the physical or chemical 
conditions. 

Page 10: 

In the figure, consider adding a few additional measures that are key 
to monitoring. For example: Under biological, indicator bacteria; under 
physical, flow; and under chemical, dissolved oxygen. These additions 
point to two of the frequent reasons for 303(d) listing of streams 
(bacteria, oxygen) along with suspended solids and nutrients already 
listed. Flow is important because flow conditions can identify times 
when contaminants have been either diluted or concentrated at a stream 
site. Also, flow information is ultimately required to establish TMDLs. 

Page 11, Footnote #7: 

Consider that probability-based monitoring is important to efficiently 
identify the overall condition of waters in a State as stated; however, 
while the results will provide the percentage of all waters in the 
State that exceed a criteria, the probability monitoring will not 
identify specifically where the reaches are that exceed the criteria. 
Thus, both probability and targeted monitoring are needed for 305(b) 
and 303(d) requirements. 

Page 23: 

First paragraph: "According to USGS officials, the purpose of its 
stringent procedures is...." Consider that statement could be 
rewritten: According to USGS officials, the purpose of its stringent 
procedures is to discover the specific amounts of trace metals in a 
water body depicting current conditions and allowing for quantification 
of water-quality time trends. 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 ambient concentrations 
measured by the USGS methods. 

Page 27: 

In the paragraph discussing the accuracy of data in the TMDL database 
and WATERS, consider that, in addition to the reasons stated in this 
paragraph for inconsistency between States listings, you also 
demonstrate on pages 17-19 that one of the additional reasons for 
variations between States is that States designate different beneficial 
uses for waters. The different uses will lead to variations between 
States in listing waters even if they use consistent methods for 
monitoring, criteria setting, and analysis for impairment decisions. 

Thank you for the opportunity to review and to comment on the draft 
report before it is finalized. 

Sincerely, 

Signed by: 

R. Thomas Weiner, for: 

Bennett W. Raley: 
Assistant Secretary for Water and Science: 

[End of section] 

Appendix III: GAO Contacts and Staff Acknowledgments: 

GAO Contacts: 

John B. Stephenson (202) 512-3841: 
Steve Elstein (202) 512-6515: 

Staff Acknowledgments: 

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. 

[End of section] 

Footnotes: 

[1] Water Quality: Key EPA and State Decisions Limited by Inconsistent 
and Incomplete Data [hyperlink, 
http://www.gao.gov/products/GAO/RCED-00-54], Mar. 15, 2000. 

[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). 

[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. 

[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. 

[6] Because 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. 

[7] 40 CFR 130.7 (b)(6)(iv). 

[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. 

[9] Data are deemed to be “reliable” if they are sufficiently complete 
and error free to be convincing for their purpose and context. 

[End of section] 

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