CLEAN WATER ACT

Changes Needed If 

Key EPA Program Is 

to Help Fulfill the 

Nation’s Water Quality 

Goals

Report to Congressional Requesters

December 2013

GAO-14-80

United States Government Accountability Office
United States Government Accountability Office

Highlights of GAO-14-80, a report to 

congressional requesters

December 2013

CLEAN WATER ACT

Changes Needed If Key EPA Program Is to Help 

Fulfill the Nation’s Water Quality Goals

Why GAO Did This Study

The 1972 Clean Water Act aimed to 

“restore and maintain the chemical, 

physical, and biological integrity of the 

nation’s waters.” Under the act, states 

must establish water quality standards; 

for waters that do not meet these 

standards, states must develop 

TMDLs, which EPA approves. TMDLs 

set targeted limits for pollutants but are 

not self-implementing; EPA and states 

help reduce pollutants by issuing 

permits for point sources, whereas 

they provide voluntary incentives to 

reduce nonpoint source pollution. 

GAO was asked to examine the TMDL 

program, specifically (1) EPA’s and 

states’ responsibilities in developing 

and implementing TMDLs, (2) what is 

known about the status of longestablished TMDLs, (3) the extent to 

which such TMDLs contain features

key to attaining water quality 

standards, and (4) the extent to which 

TMDLs exhibit factors that facilitate 

effective implementation. GAO asked 

water resource experts to review a 

random sample of 25 long-established 

TMDLs and surveyed state officials 

who are responsible for implementing 

a representative sample of 191 longestablished TMDLs. 

What GAO Recommends

GAO recommends that EPA issue new 

regulations for TMDL development, 

adding key features. Further, Congress 

should consider revising the Clean 

Water Act’s approach to addressing 

nonpoint source pollution. EPA did not 

comment on the matter for Congress. 

The agency agreed with the need to 

add key features to TMDLs but did not 

agree to issue new regulations. GAO

believes new regulations are needed. 

What GAO Found

The Environmental Protection Agency (EPA) and the states each have

responsibilities for developing and implementing pollution targets, known as total 

maximum daily loads (TMDL). EPA oversees states’ TMDL efforts by 

establishing in regulations minimum requirements TMDLs need for approval, 

providing funding, and furnishing technical assistance. States develop TMDLs

and generally take the lead in implementing them by identifying pollutants that 

impair water quality and taking actions to reduce them. 

Of about 50,000 TMDLs developed and approved, nearly 35,000 were approved 

more than 5 years ago, long enough for GAO to consider them long established. 

State officials GAO surveyed in its representative sample of 191 TMDLs reported 

that pollutants had been reduced in many waters, but few impaired water bodies 

have fully attained water quality standards.

The sample of 25 TMDLs reviewed by water resource experts GAO contacted 

seldom contained all features key to attaining water quality standards. According 

to the National Research Council and EPA, these features—some that are 

beyond the scope of EPA’s existing regulations—include identifying pollutioncausing stressors and showing how addressing them would help attain such

standards; specifying how and by whom TMDLs will be implemented; and 

ensuring periodic revisions as needed. The experts found, however, that 17 of 25 

long-established TMDLs they reviewed did not show that addressing identified 

stressors would help attain water quality standards; 12 contained vague or no 

information on actions that need to be taken, or by whom, for implementation; 

and 15 did not contain features to help ensure that TMDLs are revised if need be. 

GAO’s review showed that EPA’s existing regulations do not explicitly require 

TMDLs to include these key features, and without such features in TMDLs—or in 

addition to TMDLs—impaired water bodies are unlikely to attain standards.

In response to GAO’s survey, state officials reported that long-established 

TMDLs generally do not exhibit factors most helpful for attaining water quality 

standards, particularly for nonpoint source pollution (e.g., farms and storm water 

runoff). The officials reported that landowner participation and adequate 

funding—factors they viewed as among the most helpful in implementing 

TMDLs—were not present in the implementation activities of at least two-thirds of 

long-established TMDLs, particularly those of nonpoint source TMDLs. Because

the Clean Water Act addresses nonpoint source pollution largely through 

voluntary means, EPA does not have direct authority to compel landowners to 

take prescribed actions to reduce such pollution. In GAO’s survey, state officials

knowledgeable about TMDLs reported that 83 percent of TMDLs have achieved 

their targets for point source pollution (e.g., factories) through permits but that 20 

percent achieved their targets for nonpoint source pollution. In 1987, when the 

act was amended to cover such pollution, some Members of Congress indicated 

that this provision was a starting point, to be changed if reliance on voluntary 

approaches did not significantly improve water quality. More than 40 years after 

Congress passed the Clean Water Act, however, EPA reported that many of the 

nation’s waters are still impaired, and the goals of the act are not being met. 

Without changes to the act’s approach to nonpoint source pollution, the act’s 

goals are likely to remain unfulfilled. 

View GAO-14-80. For more information, 

contact J. Alfredo Gómez at (202) 512-3841 or 

gomezj@gao.gov. 
Page i GAO-14-80 EPA’s TMDL Program

Letter 1 

Background 7

EPA and the States Have Certain Responsibilities for Developing 

and Implementing TMDLs 18

EPA Has Limited Information about the Status of Long-Established 

TMDLs, but States Report That Few Water Bodies with Such 

TMDLs Have Attained Water Quality Standards 27

Long-Established TMDLs Experts Reviewed Seldom Contained All 

Key Features, Some of Which Are Not Included in EPA’s 

Guidance 36

Factors Reported as Facilitating the Implementation of LongEstablished TMDLs, Particularly Those for Nonpoint Source 

Pollution, Are Often Not in Place 49

Conclusions 62

Matter for Congressional Consideration 65

Recommendations for Executive Action 65

Agency Comments and Our Evaluation 66

Appendix I Objectives, Scope, and Methodology 70

Appendix II National Research Council Experts GAO Selected to Review 

TMDLs 78

Appendix III Experts’ Review of Long-Established TMDLs 79

Appendix IV Survey of State TMDL Coordinators Responsible for 

Implementing Long-Established TMDLs 84

Appendix V Comments from the Environmental Protection Agency 98

Appendix VI GAO Contact and Staff Acknowledgments 103

Contents 
Page ii GAO-14-80 EPA’s TMDL Program

Tables

Table 1: Elements for Approvable TMDLs 20

Table 2: Random Subsample of 25 TMDLs Reviewed by Water 

Resource Experts 79

Table 3: Number of Long-Established TMDLs in Which Experts 

Found Key Features Needed to Enable Water Bodies to 

Attain Water Quality Standards 80

Figures

Figure 1: Activities That Can Impair Water Bodies 8

Figure 2: An Eastern Washington Stream Channelized to Maximize 

Crop Yield 10

Figure 3: Extent of Impaired Freshwaters and TMDLs Developed 

since Passage of the Clean Water Act 14

Figure 4: Key Steps in Developing and Implementing TMDLs 19

Figure 5: Scales at Which USDA Aggregates Watershed Data, States 

Implement TMDLs, and EPA Needs GIS Data to Track 

TMDL Implementation Projects 34

Figure 6: Factors Facilitating TMDL Implementation and Extent to 

Which They Were Present in and Considered Helpful for 

Long-Established TMDLs 54

Abbreviations

EPA Environmental Protection Agency

GIS Geographic Information Systems

TMDL Total Maximum Daily Load

USDA U.S. Department of Agriculture

NRC National Research Council

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Page 1 GAO-14-80 EPA’s TMDL Program

441 G St. N.W.

Washington, DC 20548

December 5, 2013

The Honorable Barbara Boxer

Chairman

Committee on Environment and Public Works

United States Senate

The Honorable Benjamin L. Cardin

United States Senate

The Clean Water Act was enacted more than 40 years ago to “restore 

and maintain the chemical, physical, and biological integrity of the 

nation’s waters.”1 Toward this end, the act requires states to establish 

water quality standards protective of public health and the environment 

and considering aquatic wildlife and human consumption and recreation, 

among other uses; the act also requires the Environmental Protection 

Agency (EPA) to maintain and improve water quality by assisting and 

overseeing states’ efforts, among other responsibilities. As of August 

2013, EPA’s assessment of national water quality, however, reported that 

more than half the nation’s assessed waters do not meet these standards

or their designated uses, such as fishing, swimming, or drinking.2 For 

example, the assessment identified more than 12 million acres of lakes 

(or 67 percent of total assessed lake acres nationwide) and more than 

500,000 miles of rivers (or 53 percent of assessed river miles nationwide) 

as impaired; in all, the report shows, more water bodies that have been 

assessed are not meeting water quality standards than at any time in the 

past.3

 

1

The Federal Water Pollution Control Act Amendments of 1972, Pub. L. No. 92-500, § 2, 

86 Stat. 816, codified as amended at 33 U.S.C. §§ 1251-1387 (2013) (commonly referred 

to as the Clean Water Act). For consistency throughout this report, we refer to the statute 

and its amendments as the Clean Water Act. 

Furthermore, the assessment cites pollutants from nonpoint 

sources, such as agricultural runoff and stormwater runoff from some 

2

EPA, “National Summary of State Information” in Water Quality Assessment and TMDL 

Information, accessed August 19, 2013, 

http://ofmpub.epa.gov/waters10/attains_nation_cy.control. 

3

Under the Clean Water Act, states are to report every 2 years to EPA on the quality of 

the water bodies within their boundaries. In 2012, states assessed about 18 million lake 

acres, or 43 percent of lake acres nationwide, and almost 1 million river miles, or 

28 percent of river miles nationwide. 

 
 

Page 2 GAO-14-80 EPA’s TMDL Program

urban and suburban areas, as leading causes of impairment of these 

water bodies. EPA has estimated that at historical funding levels and 

water body restoration rates, it would take longer than 1,000 years to 

restore all the water bodies that are now impaired by nonpoint source 

pollution.

To improve the condition of water bodies that states identify as impaired, 

the Clean Water Act requires states to develop pollutant budgets, known 

as “total maximum daily loads” (TMDL), generally for each pollutant 

impairing a water body. A TMDL is essentially the numeric target for a 

specific pollutant, reflecting the maximum amount of the pollutant that a 

water body can contain and still be considered in compliance with water 

quality standards, and is described in a report that may also provide a 

general plan for how this target is to be achieved in the water body. 

According to EPA documents and officials, the agency’s regulations refer 

to a TMDL generally as a calculation or formula used to address one 

pollutant in one particular part of a water body, but as the program has 

evolved, the concept of a TMDL has become more expansive. Overall, 

the goal of developing a TMDL is to end up with a plan, including the 

actions needed, to meet water quality standards and restore impaired 

water bodies. After states develop TMDLs, they take the lead in 

implementing these plans, and it may take many years to see actual 

improvements in water quality.4

EPA oversees states’ TMDL development and implementation efforts 

under its TMDL program, which is a primary part of EPA’s efforts to 

restore impaired waters. In addition, several key responsibilities related to 

TMDL development and implementation are found in other EPA water 

quality-based programs. For the purposes of this report, we use the term 

“TMDL program” to include the TMDL-related responsibilities in other 

EPA water quality-based programs. To guide the development of TMDLs, 

EPA issued regulations in 1985, and revised them in 1992, which states 

are to use to this day. These regulations establish minimum requirements 

for establishing TMDLs and, according to EPA officials, should lead to 

TMDLs that, if implemented, enable water bodies to attain water quality 

standards. Under the regulations, TMDLs are to identify the applicable 

water body, pollutant of concern, and pollutant sources—as well as the 

 

4

The Clean Water Act does not expressly require implementation of a TMDL, but states 

are required to engage in a continuous planning process that includes TMDLs, among 

other things, and is to achieve water quality standards. 33 U.S.C. § 1313(e) (2013). 
 

Page 3 GAO-14-80 EPA’s TMDL Program

share of pollutant reduction to be achieved by point sources and nonpoint 

sources.5

According to EPA officials, states took little action under the Clean Water 

Act’s requirement to develop TMDLs until the mid-1990s, when citizen 

groups sued EPA in several states for not doing so in the absence of 

state action. Since that time, states developed nearly 50,000 TMDLs, in 

part as a result of EPA efforts to meet the schedules in consent decrees 

stemming from the lawsuits, according to EPA officials.6

Since EPA last revised its TMDL regulations in 1992, the agency and 

others have been asked to evaluate states’ TMDL development and 

implementation. In 1996, EPA convened a Federal Advisory Committee to 

examine the lack of progress in TMDL development and implementation 

and the pervasiveness of nonpoint source pollution.

EPA approved 

about 35,000 of these TMDLs more than 5 years ago, and, according to 

EPA officials, states should have implemented these TMDLs to some 

extent by the time of our review. For purposes of this report, we define 

TMDLs approved by EPA through December 31, 2007—that is, TMDLs 

developed more than 5 years ago—as long-established TMDLs.

7

 In 2001, the National 

Research Council (NRC) of the U.S. National Academies issued a report 

assessing the scientific basis of the TMDL program, which described a 

number of features to strengthen TMDL development and 

implementation.

8

 

5

A point source discharges pollutants from a discrete point, such as a pipe carrying 

effluent from a wastewater treatment plant or an industrial facility. Under Clean Water Act 

regulations, limits in TMDLs for pollutants from point sources are to be implemented 

through National Pollutant Discharge Elimination System permits. Under the Clean Water 

Act, the discharge of pollutants from a point source into U.S. waters is prohibited without a 

permit; facilities obtain permits from authorized states or else from the applicable EPA 

region. If TMDLs have been developed for these waters in question, the permitted limits 

for point sources must be consistent with the pollutant levels called for in the TMDLs.

For example, the report recommended that EPA’s 

TMDL program focus on improving the condition of water bodies as 

6

Consent decrees are settlement agreements signed by the parties and entered, or 

approved, by a court; they are therefore enforceable by the courts.

7

EPA, Report of the Federal Advisory Committee on the Total Maximum Daily Load

(TMDL) Program, EPA-100-R-98-006 (Washington, D.C.: July 1998).

8

National Research Council, Assessing the TMDL Approach to Water Quality 

Management (Washington, D.C.: National Academies Press, 2001). The National 

Academies comprises four organizations: the National Academy of Sciences, National 

Academy of Engineering, Institute of Medicine, and National Research Council.
 

Page 4 GAO-14-80 EPA’s TMDL Program

measured by the attainment of designated uses, such as supporting fish 

populations or human recreation, rather than administrative outputs, such 

as numbers of permits issued or TMDLs developed. The report further 

recommended that TMDLs be implemented adaptively, that is, that 

periodic assessments should determine if water bodies are attaining 

water quality standards, and TMDLs should be revised if water quality is 

not improving. More recently, EPA published a series of papers in 

response to a 2007 EPA Office of Inspector General report, which found 

that the agency had limited data on TMDL implementation activities.9 In 

these papers, EPA identified particular factors associated with TMDLs 

that have been effectively implemented—that is, factors having helped 

the water bodies to which they apply partially or fully attain water quality 

standards—including the targeting of certain federal and state funds 

toward specific practices, such as keeping cattle out of streams, in 

locations where TMDLs have been developed.10

Nearly 20 years after developing the first TMDLs, states have largely 

developed those TMDLs required by consent decree, according to EPA 

officials, but face the task of implementing the projects and activities 

described in these TMDLs to control pollution and developing TMDLs for 

other waters that states have identified as impaired.11

 

9

EPA, Office of Inspector General, Total Maximum Daily Load Program Needs Better Data 

and Measures to Demonstrate Environmental Results, Report No. 2007-P-00036 

(Washington, D.C.: Sept. 19, 2007).

EPA acknowledges 

that it must determine the extent to which the agency will encourage 

states to continue to direct their resources toward developing TMDLs for 

the tens of thousands of impaired water bodies that do not yet have them 

or focus on helping states implement the TMDLs that have already been 

developed. In this context, you asked us to study EPA’s efforts to restore 

10EPA, Developing Effective Nonpoint Source TMDLs: An Evaluation of the TMDL 

Development Process (Washington, D.C.: January 2007); EPA, Developing Effective 

TMDLs: An Evaluation of the TMDL Process (Washington, D.C.: 2007); and Center for 

TMDL and Watershed Studies, TMDL Implementation: Characteristics of Successful 

Projects, Final Report, VT-BSE doc. no. 2006-0003 (Blacksburg, VA: 2006).

11Projects described in TMDLs may include implementing best management practices on 

agricultural land to reduce nutrient-laden runoff, such as planting riparian buffers, which 

are vegetative areas along stream banks that can absorb excess nutrients before they 

enter water bodies. Activities described in TMDLs may include efforts such as nutrient 

management planning, which describes a process to develop a coordinated combination 

of projects that help farmers manage the amount, form, placement, and timing of fertilizer 

to support crop production while also minimizing polluted runoff. 
 

Page 5 GAO-14-80 EPA’s TMDL Program

and maintain the nation’s waters through its TMDL program. Our 

objectives were to examine (1) EPA’s and states’ responsibilities in the 

TMDL program, (2) what is known about the status of long-established 

TMDLs, (3) the extent to which long-established TMDLs contain key 

features that enable attainment of water quality standards, and (4) the 

extent to which such TMDLs exhibit factors that facilitate effective 

implementation.

To address each of these objectives, we reviewed EPA reports and 

independent, peer-reviewed reports on the status of TMDLs and 

assessments of TMDL implementation projects and activities. In addition, 

we visited a nonprobability sample of four states in two of EPA’s 

10 regions to review EPA’s and states’ responsibilities in developing and 

implementing TMDLs, as well as any challenges the states may have 

faced in doing so.12

• To examine the extent to which long-established TMDLs contain key 

features needed to enable a water body to attain water quality 

standards, we selected water resource experts to review a random 

subsample of 25 TMDLs drawn from the nationwide sample of 191 

long-established TMDLs.

We selected these regions and states on the basis of 

the number of TMDLs each state had developed, types of water pollution, 

differences in state authorities to implement TMDLs, and extent of each 

state’s TMDL implementation efforts. To examine what is known about 

the status of long-established TMDLs, we used an EPA database known 

as Assessment, TMDL Tracking and Implementation System. To assess 

the reliability of data from this database, we (1) electronically tested 

required data elements, (2) reviewed existing information about the data 

and the system that produced them, and (3) interviewed agency officials 

knowledgeable about the data. We found these data to be sufficiently 

reliable for purposes of this report. We also used the database to select a 

random, nationwide, representative sample of 191 long-established 

TMDLs, which we defined to be those approved by EPA through 

December 31, 2007. We used the sample of TMDLs in the following ways 

to assess TMDL development and implementation:

13

 

12Because the states we visited made up a nonprobability sample, the information we 

collected from those states is not generalizable to all states but provides examples of how 

the selected states developed and implemented TMDLs.

This subsample of 25 TMDLs is too small 

13These key features were identified in the 2001 NRC report on EPA’s TMDL program and 

in various EPA studies and guidance documents.
 

Page 6 GAO-14-80 EPA’s TMDL Program

to be representative of all TMDLs, but it is an unbiased set that 

provides detailed examples of TMDL development in specific states 

and regions and helps illustrate TMDL development challenges and 

successes. We selected three experts to review these 25 TMDLs from 

among the eight authors of the 2001 NRC report on EPA’s TMDL 

program, which is the most recent effort undertaken by the National 

Academies to evaluate the TMDL approach to water quality 

management. To increase the reliability of our findings, each TMDL 

was independently reviewed by two experts.

• To examine the extent to which long-established TMDLs exhibit 

factors EPA identified that facilitate their implementation, we surveyed 

state TMDL coordinators responsible for implementing the 191 longestablished TMDLs in our representative sample; we received 177 

responses for a 93 percent response rate to our survey.14 To perform 

this analysis, we first identified factors EPA has determined to be 

necessary for facilitating effective TMDL implementation. We then 

developed a survey on whether and to what extent these factors were 

present in the representative sample of 191 long-established TMDLs 

and whether and to what extent water quality had improved. We used 

the results of this survey to determine which factors were viewed by 

our survey respondents as helpful in TMDL implementation and, if so, 

to what extent TMDLs exhibited them. The estimates from our survey 

have a margin of error of no more than 10 percent at the 95 percent 

confidence level, unless otherwise noted.15

We also interviewed officials in each of EPA’s 10 regional offices 

responsible for reviewing and approving TMDLs. We discussed with 

these officials the extent to which regional EPA officials encourage state 

programs to ensure the presence of factors facilitating effective TMDL 

implementation. We obtained information on the regional offices’ review 

and approval of state-developed TMDLs, as well as on their oversight of 

state programs, including how the offices encourage state programs to 

ensure the presence of factors needed for effective TMDL 

 

14The population of long-established TMDLs is 34,794. 

15Survey results based on probability samples are subject to sampling error. The sample 

we drew for our survey is only one of a large number of samples we might have drawn. 

Because different samples could have provided different estimates, we express our 

confidence in the precision of our particular sample results as a 95 percent confidence 

interval. This interval would contain the actual population values for 95 percent of the 

samples we could have drawn. As a result, we are 95 percent confident that each of the 

confidence intervals in this report will include the true values in the target population, 

unless otherwise noted.
 

Page 7 GAO-14-80 EPA’s TMDL Program

implementation. Appendix I describes our objectives, scope, and 

methodology in more detail.

We conducted this performance audit from July 2012 to December 2013 

in accordance with generally accepted government auditing standards. 

Those standards require that we plan and perform the audit to obtain 

sufficient, appropriate evidence to provide a reasonable basis for our

findings and conclusions based on our audit objectives. We believe that 

the evidence obtained provides a reasonable basis for our findings and 

conclusions based on our audit objectives.

The Clean Water Act establishes a nationwide approach to improve and 

maintain the quality of rivers, streams, lakes, and other water bodies, 

which involves different programs aimed at reducing pollution of the 

nation’s waters. Under this approach, states are to set water quality 

standards, monitor water quality, and assess water quality against the 

applicable standards. Through the monitoring and assessment process, 

states are to identify water bodies that do not meet their standards, and 

these water bodies are considered to be impaired. Under the act, point 

source dischargers of pollutants must obtain permits, issued by 

authorized states or EPA regions. The permits limit the amount of 

pollutants according to specific guidelines set by EPA, as well as other 

considerations.16

 

16Section 502(6) of the Clean Water Act defines the term pollutant as “dredged spoil, solid 

waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, 

biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, 

sand, cellar dirt and industrial, municipal, and agricultural waste discharged into water.” 

Section 502(19) of the act defines pollution as “the man-made or man-induced alteration 

of the chemical, physical, biological, and radiological integrity of water.” According to the 

2001 NRC report on EPA’s TMDL program, pollution goes beyond pollutants; it includes 

pollutants and other stressors, such as habitat degradation, flow alteration, channelization, 

and loss of riparian areas.

Under the act and implementing regulations, states 

must develop a TMDL for each of the pollutants affecting each water body 

identified as impaired; in so doing, states typically identify pollutant 

sources and the actions needed to control pollution and restore water 

bodies, according to EPA documents. In identifying pollutants and their 

sources—both point and nonpoint, where applicable—a TMDL is to 

specify the amount by which one or more pollutants needs to be reduced 

to meet water quality standards. EPA’s TMDL program has evolved over 

the last several decades as nationwide efforts have shifted from a focus 

Background 
 

Page 8 GAO-14-80 EPA’s TMDL Program

on controlling point source pollutants to addressing nonpoint source 

pollution. Figure 1 shows some of the activities impairing water bodies.

Figure 1: Activities That Can Impair Water Bodies

Note: The figure shows that impairment of water bodies may stem from pollution by point sources—

which include industrial facilities, such as factories and wastewater treatment plants, and other 

sources that discharge wastewater from pipes or other discrete points—or nonpoint sources such as 

airborne pollution; agricultural fields; forestry; and runoff from roofs, lawns, parking lots, and roads.
 

Page 9 GAO-14-80 EPA’s TMDL Program

Under the Clean Water Act, each state is to establish its own water 

quality standards and review and update these standards every 3 years.17

Water quality standards consist of designated uses and water quality 

criteria.18 Designated uses reflect the intended use and value of a water 

body, such as public drinking water supply; protection of fish, shellfish, 

and other wildlife; or recreational, agricultural, industrial, and navigational 

purposes. Water quality criteria generally describe the chemical, physical, 

and biological conditions necessary to achieve and protect designated 

uses, such as nitrogen concentrations, stream structure, and health of 

aquatic life, respectively.19

EPA approves states’ water quality standards and establishes 

recommended national water quality criteria, which states can adopt, or 

states can develop their own criteria, subject to EPA approval. According 

to EPA documents, water quality standards should be comprehensive 

and strong enough to achieve the Clean Water Act’s goal of “chemical, 

physical, and biological integrity” for the state’s waters. According to the 

2001 NRC report, it is not uncommon for water bodies to be largely free 

of chemical pollutants yet still vulnerable to other stressors, including 

stressors affecting habitat, stream morphology (structure), and 

streamflow, which are critical to supporting aquatic life. For example, a 

river or stream may be channelized, as when farmers straighten the 

waterway to maximize the amount of land that can be farmed and make it 

easier to move machinery across fields, thus altering the waterway’s 

characteristics (see fig. 2). Even if stream channeling does not contribute 

 

17According to EPA documents and officials, the triennial review is to consider all the 

scientific information EPA has issued for specific pollutants since the state last updated its 

standards, adding or revising standards as necessary. EPA is to review new or revised 

water quality standards consistent with Clean Water Act requirements in connection with 

its approval role. EPA can make a determination that new or revised water quality 

standards are necessary to meet the act’s requirements. If EPA makes such a 

determination and the state fails to adopt such standards, EPA must promulgate the 

standards for the state. 

18EPA’s regulations provide that the minimum requirements for state water quality 

standards also include an antidegradation policy to maintain and protect the existing uses 

of water bodies. 

19Water quality criteria are constituent concentrations, levels, or narrative statements 

representing a quality of water that supports a particular use. EPA-recommended criteria 

are to reflect the latest scientific information on the effect of the constituent on health and 

welfare, including aquatic life. States must use EPA-recommended values or other 

scientifically defensible methods for numeric criteria. Where numeric criteria cannot be 

established, states may establish narrative criteria. 

States Set Water Quality 

Standards, Assess Water 

Quality, and Identify 

Impaired Waters
 

Page 10 GAO-14-80 EPA’s TMDL Program

many chemical pollutants to a waterway, it typically removes vegetation 

along stream banks, alters streambed structure and water flows, and 

limits the stream’s capacity to support aquatic life, according to EPA 

documents; such effects may extend far downstream.

Figure 2: An Eastern Washington Stream Channelized to Maximize Crop Yield

After setting water quality standards, states are to monitor and assess 

water quality to determine the degree to which the standards are being 

met. According to EPA documents, states generally base their water 

quality assessments on three broad types of monitoring data: chemical, 
 

Page 11 GAO-14-80 EPA’s TMDL Program

physical, and biological.20

• Chemical data include measurements of specific chemical 

constituents in water, sediments, and fish tissue. Examples include 

measuring the concentrations of metals, oils, pesticides, and nutrients 

such as nitrogen and phosphorus. Monitoring for specific chemicals 

helps states identify specific pollutants and helps trace pollutants to 

their sources.

States assess water bodies, often using each 

data type, and then integrate these data with other data types for an 

overall assessment. According to EPA documents, depending on the 

designated use for a given water body, one type of data may be more 

informative than others.

• Physical data include characteristics of water and water body 

configuration, such as temperature, flow, and physical structure. 

Physical attributes can be useful indicators of potential problems, 

often because they can modify the effects of chemicals.

• Biological data are objective measurements of living aquatic 

communities (usually aquatic insects, fish, or algae) used to evaluate 

the condition of an aquatic ecosystem. Biological data are often the 

most appropriate measures for assessing if waters can support 

aquatic life.

Using existing and readily available water quality-related data and other 

information, states identify impaired waters that do not meet applicable 

water quality standards and need TMDLs. EPA’s regulations require that 

states report biennially to EPA on the quality of their waters, and states 

generally fulfill this requirement by submitting integrated reports to EPA 

 

20According to EPA documents, to supplement these three data types, states may also 

use habitat assessments and toxicity analyses. Habitat assessments include descriptions 

of sites and surrounding land uses; condition of streamside vegetation; and measurement 

of features such as stream width, depth, flow, and substrate (bottom). States can use 

habitat assessments to supplement and interpret other kinds of data. States can generate 

toxicity analyses by exposing selected organisms, such as fathead minnows or daphnia 

(water fleas), to known dilutions of water taken from a sampling location. These tests can 

help determine whether poor water quality stems from toxins or another cause, such as 

degraded habitat.
 

Page 12 GAO-14-80 EPA’s TMDL Program

every 2 years.21

• Category 1: all designated uses are supported, no use is threatened. 

In these reports, which list impaired water bodies, each 

water body is to be listed according to the following categories:

• Category 2: available data and information indicate that some, but not 

all, designated uses are supported. 

• Category 3: there is insufficient available data and information to 

determine whether designated uses are supported. 

• Category 4a: a state developed TMDL has been approved by EPA or 

a TMDL has been established by EPA.

• Category 4b: other required control measures are expected to result 

in the attainment of an applicable water quality standard in a 

reasonable period of time.22

• Category 4c: water quality is impaired by something other than a 

pollutant, such as a dam.

• Category 5: available data and information indicate that at least one 

designated use is not being supported or is threatened, and a TMDL 

is needed. 

The TMDL program has evolved over the last several decades as 

nationwide efforts have shifted from a focus on controlling point source 

pollutants to addressing nonpoint source pollution, according to EPA 

documents. Few TMDLs were developed during the first two decades 

after the TMDL program was created under the Clean Water Act. Figure 3 

shows the extent of state-identified impaired water bodies (in acres of 

 

21Under the act, states are required to monitor and assess waters under section 305(b) of 

the Clean Water Act and to identify impaired waters under section 303(d). In 2002, EPA 

recommended that states submit “integrated reports,” which include information gathered 

under each of these provisions. According to EPA, integrated reports result in a more 

comprehensive and consistent description of states’ waters, including impaired waters. 

Not all states submit integrated reports, however, so the data EPA receives from all states 

are not uniform, according to EPA officials.

22According to EPA guidance, alternative measures are reviewed by EPA on a case-bycase basis and may include (1) permits that are stringent enough to meet water quality 

standards by the end of permit terms in water bodies impaired solely by point sources and 

(2) state regulations requiring nonpoint sources to implement certain projects, along with a 

demonstration that such projects will result in meeting water quality standards in a 

reasonable time. 

Evolution of the TMDL 

Program
 

Page 13 GAO-14-80 EPA’s TMDL Program

lakes and miles of rivers) and the cumulative number of TMDLs 

developed since passage of the act.

23

 

23The measures used by states and EPA for impaired water bodies and for water bodies 

attaining designated uses differ by water body type: specifically, acres of impaired lakes 

and miles of impaired rivers but numbers of water bodies attaining designated uses.
 

Page 14 GAO-14-80 EPA’s TMDL Program

Figure 3: Extent of Impaired Freshwaters and TMDLs Developed since Passage of the Clean Water Act

Note: Before 2002, states identified impaired water bodies using varied methods and reported them 

to EPA in varied ways, making it difficult to reliably identify the number of impaired water bodies 

nationwide, according to EPA officials.
 

Page 15 GAO-14-80 EPA’s TMDL Program

A number of major events have occurred over the last 40 years, which 

have shaped the program as it evolved. After the Clean Water Act was 

passed in 1972, EPA and the states focused primarily on, and made 

progress in, reducing pollutants discharged from point sources, but they 

made less progress in controlling nonpoint source pollution. In 1985, with 

minor amendments in 1992, EPA published regulations requiring the 

establishment of TMDLs and defining the minimum requirements TMDLs 

were to contain to qualify for approval, including the requirement that 

pollutant loads, or amounts, were to be set so as to attain water quality 

standards. Between these years, Congress in 1987 amended the Clean 

Water Act, adding section 319 to explicitly address nonpoint source 

pollution through a cooperative, grant-based program with states.24

In 1996, EPA determined that it needed a comprehensive evaluation of 

the TMDL program, in large part because of limited progress states had 

made in developing TMDLs. Moreover, environmental and public-interest 

organizations had started filing lawsuits alleging that EPA should be held 

accountable under the Clean Water Act for failure to oversee TMDL 

development efforts and should establish TMDLs where states had not 

done so. EPA convened a Federal Advisory Committee, which developed 

more than 170 separate recommendations to strengthen the TMDL 

program, ultimately reporting in 1998 that (1) restoring impaired waters 

should be a high priority; (2) implementing TMDLs, particularly those for 

nonpoint source pollution, should be the key to program success; and 

Among other provisions, the nonpoint source program was to fund 

voluntary projects aimed at curtailing nonpoint source pollution. In 

amending the act, Congress established the nonpoint source program to 

help states implement nonpoint source controls, largely through voluntary 

means and financial incentives, such as those set out in TMDLs. At the 

same time, some Members of Congress indicated that this provision was 

a starting point, to be changed if reliance on voluntary approaches did not 

significantly improve water quality.

 

24Water Quality Act of 1987, Pub. L. No. 100-4 § 316 (1987), adding § 319 to the Clean 

Water Act, codified at 33 U.S.C. § 1329 (2013).
 

Page 16 GAO-14-80 EPA’s TMDL Program

(3) strengthening the federal government’s capacity to carry out the 

TMDL program should be strengthened.25

Following on the heels of the Federal Advisory Committee’s 

recommendations, EPA in 2000 promulgated significant revisions to the 

TMDL program in a rule published in the Federal Register. The preamble 

to the rule stated that although significant improvements had been made 

to water quality—particularly in stemming pollution from point sources—

major challenges remained for addressing nonpoint source pollution. The 

rule specified elements that TMDLs needed to contain to be approved by 

EPA, including (1) implementation plans, which were to contain lists of 

specific actions to reduce pollution and schedules for reducing pollutant 

loads; (2) ”reasonable assurances” that TMDLs for waters impaired by 

point and nonpoint source pollution show that nonpoint source pollution 

would actually be reduced; and (3) a plan for monitoring implementation 

projects and activities and TMDL revision procedures if such projects and 

activities did not have the anticipated effect on water quality. Finally, the 

rule also set a goal of 5 years to implement a given TMDL and 10 years 

for attaining water quality standards whenever practicable. In the 

preamble to the rule, EPA stated that the TMDL program needed new 

regulations because existing regulations had brought about insufficient 

improvement in water quality.

In 2000, however, Congress delayed EPA’s implementation of the rule by 

prohibiting the agency from using funds made available for fiscal years 

2000 and 2001 to make a final determination on, or implement, the 2000 

rule.26

 

25The TMDL Federal Advisory Committee comprised 20 members with diverse 

geographic, policy, and professional perspectives, including state and local governments, 

tribal organizations, environmental groups, industry, agriculture, forestry, and academia. In 

addition, three federal agency officials—from EPA and the Department of Agriculture’s 

Natural Resources Conservation Service and Forest Service—served as nonvoting 

members.

Then, in association with the fiscal year 2001 appropriations bill, 

the congressional appropriations committee directed EPA to contract with 

NRC to evaluate the adequacy of scientific methods and approaches 

available to support development and implementation of TMDLs. NRC 

issued its report in April 2001, identifying features to strengthen TMDL 

development and implementation.

26EPA issued the final rule but delayed its effective date until after the spending 

prohibition would end.
 

Page 17 GAO-14-80 EPA’s TMDL Program

In 2002, EPA withdrew its rule, stating that significant changes would be 

needed before the rule could serve as a blueprint for an efficient and 

effective TMDL program. EPA also stated that it needed more time to 

evaluate whether and how to revise then-current regulations, reporting 

that the agency was not sure how long this effort would take. EPA cited 

significant controversy, pending litigation, and lack of stakeholder 

consensus on key aspects of the rule as the main challenges that a new 

rule would need to overcome. 27

In 2013, EPA drafted a long-term “vision” for its TMDL program, 

acknowledging that many TMDLs have been developed for impaired 

waters, although much remains to be done to restore water bodies to 

which TMDLs apply and to develop TMDLs for still more water bodies. 

EPA’s vision seeks to help states set priorities for TMDLs to be developed 

and implemented, now that states are emerging from several decades of 

consent-decree-driven time frames for TMDL development and have 

more flexibility in addressing technical challenges, limited funding and 

other resources, state-specific legislative and regulatory frameworks, and 

public objectives. For example, by 2016, states are to review; 

systematically set priorities for; and, in their biennial integrated reports, 

Since then, according to EPA officials, 

EPA has focused its efforts on implementing the TMDL program, 

including the review and approval of TMDLs submitted by states 

according to the 1985 regulations and 1992 amendments. EPA has also 

issued additional guidance to states on a range of topics, including on 

specific elements that a TMDL should contain.

 

27According to the Congressional Research Service, EPA’s proposal had few strong 

supporters, for varied reasons. States, which would have been directly affected by the 

rule, criticized the burdens that new requirements would place on them. They were 

concerned that they did not have resources to meet tight deadlines for developing and 

implementing TMDLs. Further, states said that TMDLs should not necessarily take higher 

priority over other elements of existing water quality management programs. Industry 

groups expressed concern about impacts of new pollution control requirements. For their 

part, municipal and industrial point source groups urged states and EPA to ensure that 

TMDL requirements did not fall disproportionately on their discharges, while possibly 

failing to address nonpoint source contributions to impaired waters. Farm groups and 

others with nonpoint discharges questioned EPA’s authority to include nonpoint source 

pollution in the TMDL program. The forestry industry vigorously criticized potential impacts 

of the rule. Environmentalists, who supported the need for a stronger and more 

comprehensive TMDL program, objected to the long periods in the rule before water 

quality improvements were likely to occur. They criticized the lack of aggressive 

implementation of a program that has existed in law since 1972. Congressional Research 

Service, Clean Water Act and Total Maximum Daily Loads (TMDLs) of Pollutants, Order 

Code 97-831 (Washington, D.C.: August 2008).
 

Page 18 GAO-14-80 EPA’s TMDL Program

identify waters for restoration and protection. Also by 2016, states are to 

identify and coordinate implementation of the water quality efforts of other 

federal agencies, such as the U.S. Department of Agriculture (USDA), to 

achieve each state’s water quality goals.

Under the Clean Water Act, EPA and the states each have certain 

responsibilities for developing and implementing TMDLs. EPA establishes 

elements for TMDLs for review and approval, funds some TMDL 

development and implementation, and provides technical assistance to 

states. States are responsible for developing TMDLs and implementing 

the pollution control actions prescribed by the plans for point sources, 

while they take the lead for implementing any actions for nonpoint 

sources.28

 

28According to EPA, “it is the responsibility of the states, through the exercise of state law, 

to implement TMDLs that establish load allocations for nonpoint sources.” See Brief for 

Defendant-Appellants at 9, Sierra Club v. Meiburg, 296 F.3d 1021 (11th Cir. 2002) (No. 

01-14587-G). 

Figure 4 shows the key steps and parties involved in 

developing and implementing TMDLs.

EPA and the States 

Have Certain 

Responsibilities for 

Developing and 

Implementing TMDLs
 

Page 19 GAO-14-80 EPA’s TMDL Program

Figure 4: Key Steps in Developing and Implementing TMDLs

a

The Clean Water Act’s approach to curtailing nonpoint source pollution depends in large part on 

voluntary participation by private landowners; other actors may include state or local regulatory or 

nonregulatory programs.

b

According to EPA officials, it may take years for changes to occur in water quality after 

implementation of best management practices or other projects and activities prescribed by TMDLs.
 

Page 20 GAO-14-80 EPA’s TMDL Program

EPA has three main responsibilities for developing and implementing 

TMDLs. First, EPA establishes regulations and guidance for TMDL 

development and reviews TMDL documents that states submit. Under 

guidance implementing the agency’s regulations promulgated in 1985 and 

amended in 1992, EPA reviews the adequacy of TMDLs on the basis of 

11 elements (see table 1). If EPA rejects a state’s TMDL, EPA must itself 

develop one for the identified water body within 30 days. According to 

EPA program officials, its regional offices review TMDL documents and 

approve them when the information provided in those documents 

demonstrates that if the TMDL were implemented as written, it would 

enable an impaired water body to attain the relevant water quality 

standards.

Table 1: Elements for Approvable TMDLs

TMDL element Description

1. Identification of water body, pollutant of 

concern, pollutant sources, and priority ranking

A TMDL should identify the water body and pollutant for which the TMDL is 

established; link between the pollutant of concern and applicable water quality 

standard; point and nonpoint sources of the pollutant of concern; and point 

source permits, if any.

2. Description of the applicable water quality 

standard and numeric water quality target

A TMDL must describe the applicable water quality standard. The TMDL must 

also identify the numeric water quality target and how meeting the target will 

allow designated uses to be attained.

3. Loading capacity—linking water quality and 

pollutant sources

A TMDL must identify the loading capacity of a water body for the applicable 

pollutant, that is, the greatest amount of a pollutant that the water body can 

receive and still attain the applicable water quality standard.

4. Load allocations A TMDL must include load allocations, which identify the portion of the loading 

capacity assigned to existing and future nonpoint sources—in other words, the 

share of the pollutant limit that nonpoint sources must meet.

5. Wasteload allocations A TMDL must include wasteload allocations, which identify the portion of the 

loading capacity assigned to each existing and future point source—in other 

words, the share of the pollutant limit that point sources must meet.

6. Margin of safety A TMDL must include a margin of safety—such as conservative assumptions—

to account for any lack of knowledge concerning the relationship between load 

and wasteload allocations and water quality.

7. Seasonal variation A TMDL must consider how seasonal variations affect loading capacity, and it 

must describe the method that accounts for seasonal variation.

8. Reasonable assurances When a TMDL is developed for waters impaired by both point and nonpoint 

sources, a “TMDL should provide reasonable assurances that nonpoint source 

control measures will achieve the expected load reductions.” This information is 

necessary for EPA to determine that the TMDL has been established at a level 

necessary to implement water quality standards.

EPA’s Responsibilities
 

Page 21 GAO-14-80 EPA’s TMDL Program

TMDL element Description

9. .Monitoring plan to track TMDL effectiveness EPA recommends that TMDLs include a monitoring plan to track effectiveness of 

implementation, particularly when a TMDL involves both point and nonpoint 

sources (emphasis added). The monitoring plan should describe data to be 

collected to determine if load reductions provided for in the TMDL are occurring 

and leading to attainment of water quality standards.

10. Implementation EPA encourages states to develop implementation plans that include reasonable 

assurances that nonpoint source pollution reductions will occur (emphasis 

added).

11. Public participation EPA recommends full and meaningful public participation in the TMDL 

development process (emphasis added). States must subject TMDL calculations 

to public review. Inadequate public participation may be a basis for disapproving 

a TMDL.

Source: EPA.

EPA’s second responsibility is to provide funding, which helps states 

develop and implement TMDLs. EPA has two grant programs under the 

Clean Water Act: grants for water pollution control programs (section 106) 

and grants for state nonpoint source management programs (section 

319). Portions of grants from EPA for water pollution control give states 

funding to assist in administering programs for the prevention, reduction, 

and elimination of pollution, including, but not limited to, TMDLs. Similarly, 

portions of grants for state nonpoint source management programs fund 

state-selected projects to reduce nonpoint source pollution and restore 

impaired water bodies. These state grant programs generally fund 

implementation of TMDLs addressing nonpoint sources. In implementing 

section 319, EPA awards funds to states, provided they meet various 

minimum conditions, including targeting funds to geographic areas in 

need of restoration and demonstrating annual progress. EPA has 

discretion by statute to (1) add terms and conditions to grants; (2) require 

additional information on applications; and (3) request additional 

information, data, and reports that it considers necessary to determine 

continuing state eligibility for grants. For example, EPA’s regional offices 

establish commitments from each state to develop a specific number of 

TMDLs each year, and each state is to report back to the relevant 

regional office how many it has developed. Under section 319, to receive 

funding, states must obtain a determination from EPA that they made 

satisfactory progress in meeting their nonpoint source program goals from 

the prior year.29

 

29Nonpoint source grant funding under section 319 is allocated to states using a formula 

established by EPA, which incorporates states’ population, cropland, pasture, forest 

harvest acreage, and other factors, set when the grant program began.
 

Page 22 GAO-14-80 EPA’s TMDL Program

For fiscal years 2008 to 2012, EPA budget was $432 million per year, on 

average, for its grants supporting state efforts under its water pollution 

and nonpoint source management programs, including for developing and 

implementing TMDLs. During this time, EPA’s water pollution control 

program was budgeted at $235.5 million per year, on average, and the 

nonpoint source management program was budgeted at $196.5 million 

per year, on average. Less than half of these amounts, however, are 

applied toward TMDL development and implementation because of the 

many other state water quality efforts they also support. For example, 

EPA officials told us, a majority of the agency’s grants under the water 

pollution control program support states’ permitting, monitoring, and 

assessment activities, not TMDL development per se. Moreover, officials 

estimated that about one-third of grants through the nonpoint source 

management program are used to implement TMDLs, whereas the 

remaining two-thirds support other aspects of states’ nonpoint source 

management programs.

EPA’s third responsibility with regard to TMDLs is to provide technical 

assistance to help states restore water bodies through the TMDL process. 

For example, in addition to developing numerous models, monitoring 

methodologies, and databases over the past several decades, the agency 

has developed recent tools to assist states in (1) identifying the causes 

and effects of various impairments and (2) assessing different water 

bodies to identify those with the highest likelihood of successful 

restoration. Specifically, according to EPA documents, EPA has 

developed tools such as the Causal Analysis/Diagnosis Decision 

Information System and the Recovery Potential Screening tools. The first 

is a web-based system that helps scientists and engineers in EPA regions 

and states assess water bodies and identify causes of impairment, with a 

focus on biological assessments. Biological assessments can evaluate 

the cumulative impacts of chemicals for which no water quality standards 

exist, as well as of nonchemical stressors such as flow alteration (e.g., 

stream channeling) and invasive species, according to EPA documents. 

The second tool is also web based and, according to EPA documents, 

assists state officials in considering where to invest their water quality 

restoration efforts for greater likelihood of success, given specific traits of 

their own geographic area and communities. The tool is to help states 

compare the relative restoration and recovery potential of large numbers 
 

Page 23 GAO-14-80 EPA’s TMDL Program

of water bodies by measuring, for each water body or watershed, several 

indicators showing the likelihood that a restoration effort can succeed.30

Under the Clean Water Act, states are responsible for developing TMDLs 

for waters they identify as impaired and, generally, for implementing the 

pollution control actions they prescribe for point sources; whereas for 

nonpoint sources, states take the lead in implementing projects and 

activities intended to achieve pollution reductions.31

• identifying the pollutant responsible for listing a water body as 

impaired;

To develop TMDLs, 

states identify individual pollutants or pollution impairing water quality; 

point and nonpoint sources of the pollution; and, generally, the actions 

needed to reduce pollution to an amount that meets water quality 

standards. TMDL development generally consists of the following steps:

• estimating the water body’s loading capacity for that pollutant;

• estimating pollutant loading in the water body from all sources;

• determining pollutant reductions to meet the loading capacity;

• allocating the allowable pollutant load among different pollutant 

sources—both point (i.e., wasteload allocation) and nonpoint (i.e., 

load allocation)—in a manner that achieves water quality; and

• describing a plan for the actions that should be implemented to 

reduce pollutants from entering the water body.

As part of the TMDL development process, states use different 

approaches for point source and nonpoint source pollution. EPA and the 

 

30For example, according to EPA documents, ecological indicators measure natural 

watershed features, such as the relative abundance of aquatic animals or plants, and the 

tool assigns an “ecological index score” that reflects the watershed’s restoration potential. 

Further, a “social context score” includes factors such as community involvement, local 

regulations, and whether any plans to improve water quality have already been 

developed, which often strongly influences how difficult restoration may be. 

31See, e.g., Sierra Club v. Meiburg, 296 F.3d 1021, 1031 (11th Cir. 2002) (explaining that 

“... the national policy and objectives relating to clean water are most reliably embodied in 

the act itself which puts the responsibility for implementation of TMDLs on the states”). As 

we previously noted, the act does not expressly require implementation of a TMDL, but 

states are required to engage in a continuous planning process which includes TMDLs, 

among other things, and which will achieve water quality standards. With respect to state 

implementation of nonpoint source controls, the act “provides no direct mechanism to 

control nonpoint source pollution but rather uses the ‘threat and promise’ of federal grants 

to the states to accomplish this task.” Pronsolino v. Nastri, 291 F.3d 1123, 1126-27 (9th 

Cir. 2002). 

States’ Responsibilities 
 

Page 24 GAO-14-80 EPA’s TMDL Program

states regulate point source discharges of pollutants by means of 

National Pollutant Discharge Elimination System permits, which are to 

incorporate overall pollutant loads—wasteload allocations—established 

by TMDLs. Under the National Pollutant Discharge Elimination System, 

all facilities that discharge pollutants from any point source into U.S. 

waters must generally obtain a permit, typically from their state or EPA 

region. During TMDL development, a state identifies each point source 

discharging to the water body subject to a TMDL and determines specific 

limits for the pollutants addressed by the TMDL that would enable the 

water body to attain water quality standards. For example, in developing 

one California TMDL, the regional water quality control board determined 

that to meet water quality standards, point sources could discharge no 

more than 5.5 pounds of nitrogen per day into the water body subject to 

the TMDL. States who issue these permits are thus responsible for 

implementing the point source control component of TMDLs. Unlike point 

source pollutants, nonpoint source pollution is not regulated through 

permitting and discharge limits. A state or EPA identifies pollution caused 

by adjacent or upstream lands contributing polluted runoff or other 

pollution to a water body and sets load allocations for particular pollutants 

of concern. The California TMDL, for example, states that nonpoint 

sources, which discharged about 84 pounds of nitrogen per day all 

together, were to collectively discharge no more than 8.5 pounds per day.

Then, depending on the state or EPA office that develops it, a TMDL may 

identify, in more or less detail, the actions needed to control or reduce 

runoff into the water body. Some states’ TMDL documents prescribe 

specific actions to reduce runoff from fields; for example, they include the 

location and type of projects and activities that may be needed to reduce 

pollution from different parcels of land. Such projects and activities 

include agricultural best management practices, such as installing fences 

to exclude cattle from stream banks, planting strips of grass along a 

stream bank to absorb nitrogen and phosphorus runoff from fertilized 

fields, or building in-stream structures to prevent sediment from flowing 

downstream. For example, the TMDL for the South Santiam River in 

Oregon describes and locates soil conditions, vegetation, and human 

uses affecting the river and its tributaries. It also describes in detail 

specific steps to address elevated temperature in the river, including 

restoring stream channels, native vegetation, and natural streamflow, and 

it aligns such steps with the specific conditions and areas within the 

TMDL’s geographic boundary. Other state TMDLs simply direct that 

runoff from all nonpoint sources is to fall below the overall load allocated 

among them. For example, the TMDL for Mariposa Lake in Iowa does not 

identify specific locations from which nonpoint source pollution comes or 
 

Page 25 GAO-14-80 EPA’s TMDL Program

the type and extent of actions needed to enable the lake to attain water 

quality standards. Runoff from 580 acres of nearby farmland flows into 

the lake, which is to support designated uses of swimming and aquatic 

wildlife, but the TMDL identifies a single maximum load of phosphorus to 

be collectively achieved from all these acres, without identifying the 

specific locations contributing the most polluted runoff or the extent to 

which actions are needed that could address polluted runoff.

Once a TMDL is developed for a water body, states have certain 

responsibilities for implementing it—that is, for taking the actions 

prescribed by the TMDL to reduce point source pollution. To implement 

TMDLs for waters impaired by point sources, states are to ensure that 

pollutant discharge levels specified in permits are consistent with the 

assumptions and requirements of any available wasteload allocation for 

the facility specified in TMDL documents.32

In contrast, states take the lead in implementing TMDLs for waters 

impaired by nonpoint source pollution by relying on projects funded 

through their nonpoint source management programs and through a mix 

of other federal and state funds.

Specifically, state staff 

determine whether the overall wasteload allocation for that pollutant can 

be met if each point source of that pollutant discharges no more than its 

permitted limit or whether a facility’s permitted limit for the pollutant in 

question needs to be lower. If a TMDL has been developed for the 

receiving waters, the permitted limits for point sources must be consistent 

with the wasteload allocations in the TMDLs.

33

 

32Forty-six states are approved by EPA to issue permits setting pollutant limits for point 

sources. For the four states that do not have this approval—Idaho, Massachusetts, New 

Hampshire, and New Mexico—EPA is responsible for incorporating TMDL limits for point 

sources into their permits.

In part because most land areas 

responsible for nonpoint source pollution are privately owned, EPA and 

the states use funding to try to secure voluntary landowner participation. 

33States develop their own project selection processes and the criteria their nonpoint 

source management programs are to consider when determining what projects to fund. 

Annually, each state submits its list of selected projects to the applicable EPA regional 

office for incorporation into the state’s work plan, which describes what projects will be 

funded through an EPA program established under section 319 of the Clean Water Act. 

Organizations that apply for funding through this program—often including conservation 

districts, local governments, and nonprofit organizations—submit project proposals to 

states’ nonpoint source management programs and, if selected, are responsible for 

implementing their proposed nonpoint source pollution projects under an agreement with 

the state.
 

Page 26 GAO-14-80 EPA’s TMDL Program

In particular, states are encouraged by EPA (under guidance 

implementing section 319 of the Clean Water Act) to coordinate with other 

agencies, particularly USDA, that fund projects that may help reduce 

nonpoint source pollution. Under the Farm Bill and other legislation, 

USDA administers agricultural conservation programs that fund best 

management practices on agricultural land, providing funding assistance 

to landowners for projects aimed at reducing soil erosion and air pollution, 

as well as nonpoint source water pollution. Such programs, including 

USDA’s Environmental Quality Incentives Program, have in the past 

received more funding than EPA’s nonpoint source management 

program, but not all such funding is specifically directed toward projects in 

impaired or threatened watersheds. For example, of the $1.4 billion in 

fiscal year 2012 that the Environmental Quality Incentives Program 

received, $33 million was specifically set aside to help farmers and 

ranchers implement conservation practices to protect water quality in 

impaired or threatened watersheds.

In addition, according to EPA documents, some states have taken steps 

through state law or guidance to further the implementation of TMDLs. 

Specifically, 10 states had taken steps to require formal TMDL 

implementation plans that specifically identified actions that could reduce 

nonpoint source pollution in a water body, according to a 2008 report.34

Implementation plans may describe how nonpoint source load allocations 

are to be achieved for individual water bodies, for several water bodies 

within a watershed, or for all affected water bodies in the state, according 

to EPA. Moreover, a handful of states regulate nonpoint source pollution 

to some extent, according to the study.35 For example, farms in 

Pennsylvania must have a conservation plan for sediment;36

 

34“State Implementation Information,” compiled by Virginia Polytechnic Institute and State 

University under EPA grant no. 83156301 (September 2008). The states include Arizona, 

California, Delaware, Hawaii, Idaho, Kansas, Minnesota, Oregon, Texas, and Virginia.

compliance 

with the plan can help farmers conserve soil. In Washington, dairies must 

have a nutrient management plan to prevent nutrients from entering 

nearby water bodies. Pennsylvania and Washington officials told us that 

35These states include California, Florida, Hawaii, Oregon, Pennsylvania, Washington, 

and Wisconsin. 

36Specifically, agricultural plowing or tilling activities and animal heavy use areas 

disturbing over 5,000 square feet are required to have a written erosion and sedimentation 

control plan, and to implement best management practices.
 

Page 27 GAO-14-80 EPA’s TMDL Program

the mechanisms are generally limited in scope, and state and local 

officials reported that success or failure to implement TMDLs addressing 

significant nonpoint source pollution depends largely on voluntary 

initiatives.

EPA tracks basic information on TMDL development, such as the 

number, location, and type of long-established TMDLs but, generally, 

does not have information on the extent to which the TMDLs have been 

implemented or have improved the quality of impaired water bodies. 

EPA’s ability to track TMDL implementation is hindered by data system 

limitations and unavailable USDA data. In addition, results from our 

survey of state TMDL coordinators show that states have little information 

on TMDL implementation, and, where information exists, few water 

bodies to which long-established TMDLs apply have attained water 

quality standards.

Through its national databases, EPA systematically tracks basic 

information related to TMDL development, but these databases contain 

limited information on the extent of TMDL implementation and associated 

changes in water quality. This basic information includes the number of 

TMDLs developed, the name of water bodies to which TMDLs apply,

pollutants contributing to impairment, and probable sources of the 

impairments, as well as information on the extent to which states use 

nonpoint source management grant funds to support TMDL development 

and implementation. Generally, EPA has information related to TMDL 

development in its Assessment, TMDL Tracking and Implementation 

System, much of which is entered by EPA regional offices with data 

provided by states. From this database, the agency knows the following 

facts, as of August 2013: 

• EPA has approved 50,184 TMDLs since fiscal year 1996, the year 

states generally began developing TMDLs; 34,794 of these, which we 

refer to as long-established TMDLs, were approved by December 31, 

2007. The information that EPA tracks shows that states have 

developed TMDLs for many water bodies the states have identified as 

impaired and that the probable causes of impairment include 

chemical, physical, and biological stressors.

EPA Has Limited 

Information about the 

Status of LongEstablished TMDLs, 

but States Report 

That Few Water 

Bodies with Such 

TMDLs Have Attained 

Water Quality 

Standards 

EPA Systematically Tracks 

Basic Information on 

TMDL Development but 

Has Limited Information 

on TMDL Implementation 

and Water Quality
 

Page 28 GAO-14-80 EPA’s TMDL Program

• The agency knows that 52 percent address only nonpoint source 

pollution, 5 percent address only point source pollution, and 

41 percent address both point and nonpoint source pollution.37

• The states with the largest number of approved TMDLs include 

Pennsylvania (7,084 TMDLs), New Hampshire (6,006 TMDLs), West 

Virginia (3,819 TMDLs), and Kansas (2,982 TMDLs).38

• Pollutant groups addressed by the largest number of TMDLs include 

pathogens, such as bacteria from feces (addressed in 

11,595 TMDLs); metals other than mercury, such as arsenic, 

cadmium, and zinc (9,010 TMDLs); mercury (7,046 TMDLs); nutrients 

such as nitrogen or phosphorus (5,466 TMDLs); and sediment 

(3,783 TMDLs).

• The probable sources of stressors contributing to impairments may 

vary by type of water body and include agricultural runoff, municipal 

discharges (sewage), and atmospheric deposition39

EPA has two additional databases that contain information about TMDL 

implementation, but these databases contain limited information on the 

extent of TMDL implementation and associated changes in water quality. 

As a result, EPA cannot use its different databases to assess the extent 

to which most TMDLs have been implemented, and it does not have 

comprehensive, nationwide information on whether and to what extent 

TMDLs have led to improved water quality. In its Permit Compliance 

System or Integrated Compliance Information System, EPA tracks data 

on point sources, including permitted pollutant levels associated with 

 into rivers, 

streams, lakes, ponds, bays, and estuaries. Other significant stressors 

include habitat alterations and physical modifications (e.g., altering 

water flow patterns by straightening streams or building dams).

 

37Some TMDLs in the database did not have a TMDL type listed, so the percentages do 

not add to 100. 

38These data do not necessarily mean that states with the most TMDLs have the most 

impaired waters. Pennsylvania’s water body assessment units are relatively small, 

meaning that one stream may have dozens of assessment units and, if impaired, require 

dozens of TMDLs. In addition, New Hampshire was credited with thousands of TMDLs for 

completing one TMDL document—the New England Mercury TMDL—that applied to all 

water bodies in the state. 

39Atmospheric deposition—a process that transfers pollutants from the air to the earth’s 

surface—can significantly impair water quality in the nation’s rivers, lakes, bays, and 

estuaries and harm human health and aquatic ecosystems. In particular, airborne 

pollutants can fall to the ground in precipitation or as a gas or particle and be deposited 

either directly onto the surface of a water body or onto land and then transported into a 

water body through runoff. 
 

Page 29 GAO-14-80 EPA’s TMDL Program

TMDLs.40

• Whether sufficient information existed in the databases to assess 

TMDL implementation status. EPA determined that a limited number 

of TMDLs could be assessed for implementation status. For example, 

in a 2010 report, the agency found that 17 percent of point source 

TMDLs and 8 percent of nonpoint source TMDLs had all of the data 

elements needed for TMDL implementation status to be addressed.

In its Grants Reporting and Tracking System, EPA tracks data 

on EPA-funded projects and activities that may help reduce nonpoint 

source pollution to meet levels called for in TMDLs. To track TMDL 

implementation and any associated effect on water quality, EPA and 

states need to know what actions have been taken to reduce pollution in 

a watershed with a TMDL and how much pollution has been reduced as a 

result, according to program officials. Through several studies, EPA has 

integrated information in its databases, where available, to assess the 

status of pollution control actions prescribed in TMDLs and the extent to 

which water quality improved from these efforts. Specifically, EPA 

conducted several studies, most in response to the 2007 EPA Office of 

Inspector General report, which found that the agency had limited data on 

TMDL implementation activities; these studies examined the following 

issues: 

41

• Whether point source permits had been revised to include TMDL 

limits. EPA found in a 2009 study that wasteload allocations for point 

sources were generally incorporated into discharge permits. 42

 

40EPA and the states are making a transition from the national database known as the 

Permit Compliance System to a database called Integrated Compliance Information 

System: NPDES. The states are divided in their use of the two databases.

The 

study showed that of 399 wasteload allocations set by 100 TMDLs, a 

majority (68 percent) was consistent with existing limits established in 

discharge permits, and no permit revisions were needed. 

Eleven percent required permit revisions and such revisions had been 

made, and 21 percent of wasteload allocations required permit 

revisions, but revisions had not been made. All the wasteload 

allocations for which permit revisions had not been made pertained to 

municipal stormwater or combined sewer overflows, for which permit 

revisions are not straightforward, according to EPA.

41EPA, FY2010 National Report on Implementing Total Maximum Daily Loads (TMDLs), 

Document No. EPA841-R-11-002 (Washington, D.C.: March 2011).

42EPA, Analysis of TMDL Implementation Rates in EPA Region 5, EPA841-R-09-005 

(Washington, D.C.: Dec. 1, 2009).
 

Page 30 GAO-14-80 EPA’s TMDL Program

• Whether TMDLs have implementation plans for carrying out actions to 

control pollution. In a 2007 study, EPA assessed how stakeholder 

participation and implementation planning, which may occur during 

TMDL development, affect implementation.43

• Whether TMDLs have helped improve water quality. A 2008 study 

funded by EPA on TMDL implementation status in Ohio and West 

Virginia,

As part of this study, 

EPA surveyed regional officials responsible for TMDLs and found that 

37 percent of TMDLs often or always have implementation plans, and 

46 percent reported that TMDLs never or seldom have 

implementation plans.

44 that officials responsible for implementing TMDLs were not 

aware of some TMDLs developed for watersheds under their 

jurisdiction and that incremental improvements in water quality had 

occurred in less than 20 percent of watersheds. For example, for the 

63 TMDLs sampled, the study found that agency officials did not know 

whether any TMDL implementation activities had occurred for 18 of 

them. The study found that implementation of pollution control actions 

had occurred in 29 of the 63 watersheds in the sample. Incremental 

improvements in water quality had occurred in 12 of the 

63 watersheds, and full water body restoration had occurred in 2 of 

the 63 watersheds.45

EPA is hindered in its ability to track TMDL implementation results 

because of data system limitations, as well as the fact that data on water 

quality projects paid for by USDA are generally unavailable. First, EPA’s 

databases, which contain information uploaded from states’ databases, 

function independently of one another. Because information relevant to 

TMDL implementation is not consistently tagged with geographic 

information system (GIS) data (i.e., latitude-longitude coordinates on 

water body segments, permitted discharge locations, and the spatial 

extent of projects addressing nonpoint source pollution), as opposed to 

water body names and states, the information on TMDL implementation 

 

43EPA, Developing Effective Nonpoint Source TMDLs: An Evaluation of the TMDL 

Development Process. (Washington, D.C.: January 2007).

44John Hoornbeek et al., Implementing Total Maximum Daily Loads: Understanding and 

Fostering Successful Results (Kent, Ohio: Kent State University, December 2008).

45In the watersheds where water quality improved, it was unclear whether the TMDLs 

caused these incremental improvements or whether the improvements would have 

occurred even in the absence of the TMDLs.

EPA’s Ability to Track 

TMDL Implementation Is 

Hindered by Data System 

Limitations and 

Unavailable USDA Data
 

Page 31 GAO-14-80 EPA’s TMDL Program

projects and impaired water bodies generally cannot be integrated across 

separate databases.46

EPA’s Office of Inspector General, in its 2007 report, recommended that 

EPA annually report on the progress of TMDL implementation activities 

and their effects on water quality. EPA officials explained to us that such 

an effort would be expensive (both to develop the system and to expand 

monitoring efforts to detect changes in water quality) and that limited 

funding should instead be invested in projects to control pollution. EPA 

program officials told us that in the present budget environment, they 

hesitate to ask states to invest additional resources or reallocate funding 

to track the water quality effects of TMDL implementation projects or 

update their databases. Nevertheless, EPA program officials told us, 

requiring states to report GIS data associated with TMDL implementation 

is more feasible than asking them to create new data systems or to 

merge existing ones with EPA’s systems. EPA officials said that they are 

beginning to obtain GIS information associated with projects in the Grants 

Reporting and Tracking System for some nonpoint source TMDLs, but 

they acknowledged that this data-gathering effort will not provide 

As a result, EPA cannot link (1) information on 

TMDL implementation projects and activities from its Grants Reporting 

and Tracking System with (2) information on impaired water bodies or the 

causes of their impairment from the Assessment, TMDL Tracking and 

Implementation System and can therefore not assess the extent to which 

TMDLs have been implemented in watersheds with impaired water 

bodies. According to TMDL program officials, to link TMDL information in 

several databases, the agency must have GIS data—not just the water 

body name—for the extent of waters addressed by each data point for 

each TMDL. Nevertheless, the data that states enter into their own 

systems and upload to EPA’s databases do not consistently include this 

information, in part because EPA does not require the information and in 

part because state officials developed the majority of TMDLs before the 

widespread use of GIS, according to program officials. Without 

consistently obtaining from states GIS data in addition to water body 

names, EPA cannot integrate information on TMDL implementation 

projects and impaired water bodies across separate databases and 

cannot assess whether and to what extent water quality has been 

affected by TMDL implementation.

 

46GISs manipulate, analyze, and graphically present an array of information associated 

with geographic locations.
 

Page 32 GAO-14-80 EPA’s TMDL Program

information on the specific type, amount, or location of projects that have 

been implemented for all the TMDLs in the database—information that 

would generally be needed to ascertain the effect of TMDL 

implementation on water quality.

A second reason that EPA has limited ability to track TMDL 

implementation results is that many USDA-funded projects undertaken on 

agricultural land adjacent to water bodies with TMDLs cannot be tracked 

by EPA or state water quality programs because of privacy provisions in 

the 2008 Farm Bill.47 In more than one thousand watersheds across the 

country, USDA funds conservation projects to implement best 

management practices that reduce soil erosion, water pollution, and air 

pollution, and many of these projects help curb pollutants like nutrient 

runoff from agricultural fields. EPA officials told us that data on the 

location, type, and number of these projects could help identify whether 

and to what extent TMDLs have been implemented and whether water 

quality has improved as a result. Statutory provisions enacted as part of 

the 2008 Farm Bill, however, protect the identity and location of 

landowners and other agricultural producers who participate in USDAfunded conservation programs, including those implementing best 

management practices. Specifically, the provision prohibits USDA 

employees or contractors from sharing certain information concerning the 

land and operations of agricultural producers who participate in USDA 

conservation programs; the department also cannot share GIS 

information about agricultural land or operations.48

According to EPA officials, USDA has collected data on projects that it 

funded, but these data are summarized and presented on fairly large 

geographic scales—scales too large to match to watersheds with TMDLs. 

The provision, 

however, does not prohibit landowners and agricultural producers from 

consenting to disclosure or disclosing information on the specific best 

management practices that USDA has funded on their land. As a practical 

matter, according to EPA program officials, the biggest single information 

gap that limits tracking of implementation of nonpoint source TMDLs is 

the lack of information on the location of USDA-funded best management 

practices. 

 

47Pub. L. No. 110-246 § 1619(b)(2), codified at 7 U.S.C. § 8791(b)(2) (2013).

48The provision has a limited exception for aggregated data and certain statistical 

information.
 

Page 33 GAO-14-80 EPA’s TMDL Program

According to EPA program officials, such aggregated USDA data cannot 

be used to assess the effects of projects put in place to implement 

TMDLs because TMDLs typically apply to much smaller areas than 

represented by these data. To track the effectiveness of TMDL 

implementation, program officials told us, EPA generally needs data on 

specific best management practices implemented at specific sites on 

individual parts of a stream within a watershed. USDA’s data, in contrast, 

are collected and aggregated for areas that cover, on average, 

10,000 square miles, encompassing, for example, several rivers and their 

tributaries, according to EPA officials (see fig. 5).49

 

49In some cases, USDA has aggregated and shared with states data for areas that cover, 

on average, 1,500 square miles, according to EPA officials.

EPA TMDL program 

officials told us that their senior managers have not formally discussed 

with USDA the availability of the department’s data to EPA, primarily 

because of the sensitivity of this issue with USDA and its need to abide 

by the privacy provisions of the Farm Bill. Nevertheless, without access to 

data on the location, type, and number of projects implemented by 

landowners who participate in conservation programs funded by the 

USDA in areas subject to a TMDL, EPA cannot track actions taken to 

implement TMDLs and subsequent changes in water quality associated 

with a core EPA program and a substantial federal investment.
 

Page 34 GAO-14-80 EPA’s TMDL Program

Figure 5: Scales at Which USDA Aggregates Watershed Data, States Implement TMDLs, and EPA Needs GIS Data to Track 

TMDL Implementation Projects 

Note: USDA aggregates watershed data at the scales shown at top left; TMDLs are implemented at 

scales shown at top right (each of the colored stream segments A, B, and C is subject to a TMDL); 

and EPA needs data on the scale of TMDL implementation projects shown at bottom right. To track 
 

Page 35 GAO-14-80 EPA’s TMDL Program

USDA-funded projects implemented near and in impaired water bodies, EPA would need project 

information tagged with GIS data (i.e., latitude-longitude coordinates), in addition to water body 

names and states. According to EPA officials, however, data that USDA has on TMDL projects it 

funded, such as projects to plant or protect vegetation along stream banks (bottom right), are 

summarized and presented on fairly large geographic scales (top left), which are too large to match to 

watersheds with TMDLs (top right).

Our survey of state TMDL coordinators responsible for implementing 

long-established TMDLs showed that state TMDL coordinators do not 

know the extent to which many long-established TMDLs have been 

implemented. For those TMDLs where information exists, state 

coordinators reported that pollutants had been reduced in many waters, 

but few TMDLs had helped water bodies attain water quality standards. 

State TMDL coordinators did not know the status of TMDL 

implementation for slightly less than half of the long-established TMDLs. 

Specifically state coordinators reported that they did not know (1) if 

wasteload allocations had been met for 36 percent of point source 

TMDLs,50

Among state TMDL coordinators who had information on the extent of 

TMDL implementation, coordinators reported that a higher proportion of 

long-established point source TMDLs helped water bodies attain water 

quality standards than did nonpoint source TMDLs. When state TMDL 

coordinators were knowledgeable about TMDLs addressing point 

sources, they reported that for 83 percent of long-established TMDLs, 

wasteload allocations the TMDLs called for had been met.

or (2) whether load allocations had been met for 48 percent of 

nonpoint source TMDLs. Moreover, these coordinators did not know 

whether pollutant levels had changed in 35 percent of nonpoint source 

TMDLs.

51

 

50For certain survey questions, we received fewer than 100 responses. Where the margin 

of error for such responses is greater than 12 percent, we list the 95 confidence interval as 

(X, Y). For this estimate, the 95 percent confidence interval is (21, 50). 

When state 

TMDL coordinators were knowledgeable about TMDLs addressing 

nonpoint sources, however, they reported that 20 percent of load 

allocations had been met. According to state officials, this discrepancy 

exists primarily because actions called for in TMDLs for nonpoint source 

pollution either have not been implemented or have been implemented to 

a limited extent. Furthermore, state TMDL coordinators reported that they 

expected 13 percent of water bodies with TMDLs for nonpoint source 

pollution to attain water quality standards within the next 5 years.

51The 95 percent confidence interval for this estimate is (70, 96). 

States Report Having Little 

Information on TMDL 

Implementation, as Well as 

Limited Improvement in 

Water Quality
 

Page 36 GAO-14-80 EPA’s TMDL Program

Long-established TMDLs often do not contain key features that would 

help water bodies attain water quality standards, in part because EPA’s 

regulations and guidance do not direct TMDLs to contain them. NRC and 

EPA have identified key features that TMDLs should contain to help 

impaired water bodies attain water quality standards. Water resource 

experts who reviewed a sample of 25 long-established TMDLs reported 

that these TMDLs do not contain many of these key features. In addition, 

in reviewing EPA’s guidance on how regional offices are to apply EPA’s 

11 TMDL elements, we found that the guidance does not contain some of 

these key features and that some of these elements are vague, which has 

led EPA’s regional offices to apply them in different ways and to approve 

TMDLs of variable quality.

A 2001 NRC report and several EPA studies and guidance documents 

have identified key features for TMDL development, which would help 

water bodies attain water quality standards if TMDLs were implemented.52

The 2001 NRC report identified key features that help ensure that TMDLs 

accurately identify and address the causes of water body impairment. 

These key features include (1) evidence that impairment is driven by the 

stressor or stressors for which a TMDL is being developed and 

(2) evidence that addressing the stressor or stressors in question will be 

sufficient for the water body to attain its designated use or uses, as 

follows:

We grouped these key features into three categories on the basis of the 

sequence of steps in the TMDL process: those that help ensure that 

(1) TMDLs accurately identify and address causes of impairment, 

(2) TMDLs can be implemented, and (3) TMDLs are revised if found to be 

ineffective in helping water bodies attain water quality standards. The 

steps in these three categories reflect a more expansive view of TMDLs 

than what EPA’s existing regulations require TMDLs to include, according 

to EPA officials. 

• Evidence that impairment is caused by the stressors a TMDL is 

developed to address. The 2001 NRC report recommended that 

states conduct a thorough water body assessment before developing 

a TMDL to accurately and completely identify specific stressors or 

 

52NRC and EPA identified key features in addition to the ones we discuss (see app. III).

Long-Established 

TMDLs Experts 

Reviewed Seldom 

Contained All Key 

Features, Some of 

Which Are Not 

Included in EPA’s 

Guidance 

Certain Features Are Key 

If TMDLS Are to Help 

Water Bodies Attain Water 

Quality Standards

Accurately Identifying and 

Addressing Causes of 

Impairment
 

Page 37 GAO-14-80 EPA’s TMDL Program

causes of impairment. NRC reported that thousands of water bodies 

had been placed on states’ impaired waters lists on the basis of 

limited data, rather than a thorough assessment. Evidence from a 

thorough water body assessment before TMDL development 

establishes whether and to what extent the stressor or stressors 

prompting a state to list a water body as impaired are indeed causing 

impairment.

• Evidence that addressing these stressors will be sufficient for a water 

body to attain designated uses. NRC recommended that TMDLs be 

developed to consider multiple stressors—be they pollutants entering 

a water body, such as sediment or nutrients, or other human-induced 

forms of pollution, such as stream straightening, altered flows, or 

removal of streamside vegetation—in large part because waters are 

often impaired by multiple stressors.53

 

53For example, a water body may no longer support native fish populations because of 

phosphorus runoff from nearby farms, the introduction of invasive species, and degraded 

streamside habitat. These stressors interact with one another, making it difficult to isolate 

and treat one stressor at a time. TMDLs that do not address the multiple stressors causing 

impairment of the water body in question—for example, a TMDL developed on the 

assumption that phosphorus alone is responsible for the absence of native fish—does not 

provide evidence that addressing the stressor or stressors in question will be sufficient for 

the water body to attain its designated use or uses.
 

Page 38 GAO-14-80 EPA’s TMDL Program

EPA studies and guidance documents have identified key features to help 

ensure that TMDLs can be implemented. These key features include (1) a 

plan for TMDL implementation that specifically identifies who must 

undertake what projects to control pollution (i.e., plan specifies actors) 

and on what land areas (i.e., plan specifies locations) and (2) a 

demonstration of reasonable assurances that projects to control nonpoint 

source pollution will actually be implemented, and to an extent that allows 

the water body to meet load allocations specified in the TMDL. These 

features may be described as follows:

• Plan for TMDL implementation. An EPA study recommended that 

states prepare and submit implementation plans for TMDLs to help 

ensure that TMDLs, once developed, actually help lead to attainment 

of water quality standards.54 Other EPA studies have confirmed that 

effective TMDLs include or are accompanied by detailed plans for 

TMDL implementation that specify actors, as well as specific locations 

in need of remediation, to target efforts at those responsible for the 

problem, thus facilitating implementation.55

• Reasonable assurances that implementation activities will occur. EPA 

guidance states that when a TMDL is developed for waters impaired 

by both point and nonpoint sources, a TMDL should provide 

reasonable assurances that measures to control nonpoint source 

pollution will achieve the expected load reductions. According to an 

EPA study, such assurances may include identifying landowners who 

will actually implement necessary projects.56

Key features in the 2001 NRC report that help ensure that TMDLs are 

reviewed and revised if found to be ineffective in helping water bodies 

attain water quality standards include (1) a plan to monitor a TMDL’s 

effect on water quality, including monitoring biological indicators, such as 

Without reasonable 

assurances, EPA cannot be certain that limits in a TMDL for both 

point and nonpoint source pollution have been established at levels 

sufficient to attain water quality standards, according to EPA 

guidance.

 

54EPA, Report of the Federal Advisory Committee. (1998).

55Brian Benham et al., “TMDL Implementation: Lessons Learned,” Proceedings of the 

Water Environment Federation, TMDL 2007, vol. 2007, pp. 428-442 (2007) and Center for 

TMDL and Watershed Studies, TMDL Implementation: Characteristics of Successful 

Projects, Final Report, VT-BSE doc. no. 2006-0003 (Blacksburg, Va: 2006).

56EPA, Report of the Federal Advisory Committee (1998).

Ensuring That Implementation 

Can Be Done 

Revising TMDLs as Needed 
 

Page 39 GAO-14-80 EPA’s TMDL Program

the diversity and abundance of aquatic organisms, and (2) a description 

of an adaptive approach to implementing the TMDL, whereby monitoring 

data will be used to periodically assess progress toward attaining water 

quality standards and to adjust the TMDL if needed, as follows:

• Plan to monitor a TMDL’s effect on water quality. The NRC report 

recommended that TMDLs include plans for post-implementation 

monitoring to ensure that actions taken as a result of a TMDL are 

effective at helping meet water quality standards. Further, according 

to the NRC report, such monitoring should include monitoring 

biological indicators, such as aquatic plants and animals, because 

such indicators provide a more accurate assessment of water body 

health with respect to designated uses, such as fishing or swimming, 

than chemical indicators alone. According to the report, aquatic plants 

and animals reflect the totality of their living conditions, including the 

chemical, physical, and biological stressors that impair specific water 

bodies.

• Adaptive implementation approach. The NRC report recommended 

that TMDLs follow an adaptive approach, in which monitoring data are 

used to revise and improve a TMDL over time. An adaptive approach 

allows states to implement pollution control actions, monitor the 

effects of those actions, and then revise the TMDL as needed. 

According to the NRC report, comparing results predicted during 

TMDL development against empirical data from the water body serves 

to verify that water quality is improving and that progress is in fact 

being made toward attaining designated uses.

Three water resource experts reviewed a sample of 25 long-established 

TMDLs and reported that many of them do not contain features identified 

as key if TMDLs are to help water bodies attain water quality standards.57

 

57Each TMDL was independently reviewed by two experts to increase the reliability of our 

findings. The water resource experts reviewed a random subsample of 25 TMDLs that we 

drew from the nationwide sample of 191 of long-established TMDLs. 

The experts reported that many of the TMDLs they reviewed do not 

contain key features that accurately identify and address the causes of 

water body impairment, about half do not contain key features that help 

ensure that implementation can be done, and few contain key features 

that help ensure that TMDLs are revised if they are found to be ineffective 

in helping a water body attain water quality standards. As a result, they 

Experts Reported That the 

25 TMDLs They Reviewed 

Seldom Contained All 

Needed Key Features
 

Page 40 GAO-14-80 EPA’s TMDL Program

expressed little confidence that most of the TMDLs they reviewed 

would—if implemented—lead to attainment of water quality standards.

The three water resource experts reported that many of the 25 TMDLs 

they reviewed do not contain key features to help ensure that TMDLs 

accurately identify and address the causes of water body impairment. 

Experts also reported that the TMDLs that do not diagnose and aim to 

treat the true causes of water body impairment are unlikely to lead to 

attainment of designated uses.

• Evidence that impairment is caused by the stressors a TMDL is 

developed to address. Experts agreed that although 18 TMDLs they 

reviewed contain sufficient evidence that the water body in question 

was impaired by the stressor the TMDL was developed to address, 

6 other TMDLs do not contain sufficient evidence linking stressor to 

impairment.58

• Evidence that addressing stated stressors will be sufficient for a water 

body to attain designated uses. The experts agreed that 7 of the 

25 TMDLs they reviewed demonstrate that addressing the identified 

stressor would be sufficient to attain the applicable designated use or 

For example, the experts reported that a TMDL from an 

Alabama creek, approved by EPA in 2002, provides monitoring data 

showing that levels of the cause of impairment in question—dissolved 

oxygen—did not indicate impairment. The TMDL states that samples 

drawn from the creek did not identify any violation of the water quality 

standard for dissolved oxygen. Nonetheless, because the creek was 

placed on the state’s impaired waters list as a result of low dissolved 

oxygen, the TMDL was developed to address dissolved oxygen 

levels. The TMDL also refers to physical stressors that could have 

contributed to impairment, such as low water flow, but does not 

thoroughly assess these stressors or seek to treat them, according to 

the experts. The experts said that by targeting an unsubstantiated 

stressor and potentially overlooking other causes of impairment, the 

TMDL is unlikely to help the water body attain its designated use of 

supporting fish and wildlife.

 

58Experts did not agree about whether the remaining TMDL contains sufficient evidence. 

In this section of our report, we generally present only the total number of TMDLs that 

experts agreed do and do not contain particular key features, with the remainder equaling 

the number of TMDLs for which experts (1) did not agree about whether a key feature is 

present or absent, (2) agreed that not enough information was contained in the TMDL to 

determine whether a key feature is present or absent, or (3) agreed that a key feature 

does not apply to the TMDL.

Many of the TMDLs Experts 

Reviewed Do Not Accurately 

Identify and Address Causes of 

Impairment
 

Page 41 GAO-14-80 EPA’s TMDL Program

uses but that 17 other TMDLs do not demonstrate such a link.59 The 

experts said that in the water bodies for which most of these 

17 TMDLs were developed, stressors other than the stressor or 

stressors addressed by the TMDL were at play and that the TMDLs 

do not address these stressors. For example, the experts agreed that 

in 8 of the 17 TMDLs, biological stressors were probably contributing 

to water body impairment, but the TMDLs do not address these 

biological stressors; in 9 other TMDLs, the experts reported that 

physical stressors were probably contributing but that they are not 

addressed in the TMDLs.60

The water resource experts reported that about half of the TMDLs they 

reviewed do not contain key features helping to ensure that 

implementation can be done, which leads to TMDLs that may do little to 

actually improve water quality, as follows:

For example, the experts reported that a 

TMDL approved by EPA in 2007 for a watershed in Maryland, which 

had active and abandoned mining operations, aims to treat low pH, 

indicating acidic water. According to the experts, however, mining is 

likely to result in stressors besides acidity, such as physical stressors 

including habitat degradation from stream channelization, and 

sedimentation caused by past and present land disturbances. The 

experts stated that the TMDL lays out a realistic approach for 

addressing the low pH caused by chemical pollutants and could thus 

likely help meet a numeric water quality target for pH. Nevertheless, 

they said, the TMDL would likely fall short of helping the water body 

attain its designated use—even if the numeric water quality target for 

pH were met—because the physical stressors they said are likely 

present, such as habitat degradation from stream channelization and 

other mining activities, would still be present. One expert said that the 

TMDL’s narrow focus provides a false promise that addressing the 

chemical pollutants would solve the water quality problem.

• Plan for TMDL implementation. The experts agreed that 13 of the 

25 TMDLs they reviewed contain detailed information about 

 

59Experts agreed that the remaining 1 of the 25 TMDLs does not contain enough 

information to determine whether this key feature is present or absent. 

60Overall, 12 of the 17 TMDLs apply to water bodies that are subject to additional TMDLs 

the experts did not review, but most of these other TMDLs also address only chemical 

pollutants and therefore may not mitigate physical and biological stressors. The experts 

reported that the contribution of multiple, nonchemical stressors makes it highly unlikely 

that designated uses will be attained by addressing one or a few chemical pollutants. 

About Half of TMDLs Reviewed 

by Experts Do Not Have 

Features Ensuring That 

Implementation Can Be Done
 

Page 42 GAO-14-80 EPA’s TMDL Program

implementation but that the other 12 TMDLs contain vague or no 

information about implementation.61 Specifically, the experts agreed 

that 4 of these 12 TMDLs do not discuss how the TMDL is to be 

implemented: the TMDLs contain no references to implementation or 

a stand-alone implementation plan. The experts also agreed that the 

other 8 of the 12 TMDLs discuss implementation to some extent, but 

6 of these 8 TMDLs do not identify specific actors who are to support 

implementation, and 7 of these 8 do not identify actions that need to 

occur to attain water quality standards.62

• Reasonable assurances that implementation activities will occur. The 

experts agreed that for a different group of 13 of the 25 TMDLs they 

reviewed, which involved both point and nonpoint source pollution—

TMDLs that, according to the reasonable assurances element in 

EPA’s guidance, are to provide reasonable assurances that projects 

to reduce nonpoint source pollution will achieve expected load 

reductions—5 TMDLs do not include a reasonable assurances 

element but were nevertheless approved. Of the 8 TMDLs that the 

experts agreed discuss reasonable assurances, the experts reported 

that 6 do not provide sufficient evidence that reductions in nonpoint 

source pollution will actually occur, such as identification of 

landowners willing to implement necessary projects to reduce 

For example, the experts 

reported that a South Dakota TMDL, approved by EPA in 2001, briefly 

discusses implementation but does not identify the actions or the 

actors needed to implement the TMDL. The experts told us that this 

brief discussion is unlikely to lead to attainment of water quality 

standards. A South Dakota water quality official who responded to our 

survey of states reported that as part of developing this TMDL, the 

state did not identify the landowners who needed to undertake 

projects to reduce nonpoint source pollution. The official added that 

nonpoint source load allocations have not been met and that nonpoint 

source loads are expected to stay the same over the next 5 years.

 

61Experts reviewed implementation information contained within the 25 TMDL documents 

as well as in accompanying implementation plans, where present, that were issued as 

separate documents. 

62Of the 8 TMDLs that discuss implementation to some extent, the experts agreed that 

2 of them identify actors who are to support implementation but are missing other key 

features related to implementation. They agreed that 1 of these 8 TMDLs identifies actions 

that need to occur to attain water quality standards but is missing another key feature 

related to implementation.
 

Page 43 GAO-14-80 EPA’s TMDL Program

nonpoint source pollution.63

The three experts agreed that almost all of the 25 TMDLs they reviewed 

are missing one or more of the key features that help ensure that TMDLs 

are revised if they are found to be ineffective in helping a water body 

attain water quality standards. Experts said that without adequate 

monitoring plans and an adaptive implementation approach to verify the 

accuracy of the TMDL and the effectiveness of remediation efforts, 

resources may be wasted developing and implementing TMDLs that do 

little to improve the condition of water bodies.

For example, the experts reported that an 

Indiana TMDL, approved by EPA in 2006, does not identify specific 

projects to reduce nonpoint E. coli bacteria stemming from sources 

such as manure applications on farmland and leaking septic tanks. 

The TMDL instead includes a generic list of projects and activities 

related to implementation, such as educating homeowners who have 

septic systems. According to the experts, such a list does not provide 

reasonable assurances that the projects and activities will be put in

place or that load reductions laid out in the TMDL will be achieved. An 

Indiana water quality official responding to our survey of states 

reported that although nonpoint pollutant loads in this water body 

have decreased to some degree, load allocations have not been met 

and are not expected to be met within the next 5 years.

• Plan to monitor a TMDL’s effect on water quality. The experts agreed 

that 7 of the 25 TMDLs do not include a monitoring plan to track the 

TMDLs’ effectiveness. Of the 18 TMDLs that include such a plan, the 

experts reported that 14 do not include indicators of biological 

outcomes, and 3 do.64

 

63Experts did not agree on whether the remaining 2 of the 8 TMDLs that discuss 

reasonable assurances provide sufficient evidence that reductions from nonpoint sources 

will occur.

For example, the experts said that an Oregon 

TMDL for water temperature, approved by EPA in 2007, does not 

include plans to monitor biological indicators, such as the number and 

condition of fish and other aquatic organisms. The experts gave the 

TMDL credit for its plans to monitor temperature changes that might 

result from implementing the TMDL but said that without tracking 

biological conditions affected by temperature, it would be impossible 

to assess whether progress were being made toward the water body’s 

64The experts disagreed about whether the remaining 1 of the 18 TMDLs includes 

indicators of biological outcomes.

Few TMDLs Have Features 

That Ensure They Will Be 

Revised as Needed 
 

Page 44 GAO-14-80 EPA’s TMDL Program

designated use of supporting salmon, trout, and other cold-water fish 

species.

• Adaptive implementation approach. The experts reported that of the 

18 TMDLs that include a monitoring plan, 8 do not describe an 

adaptive approach to TMDL implementation—that is, an approach 

that uses monitoring and data analysis to periodically assess progress 

toward attaining water quality standards and adjust the TMDL as 

needed. The experts agreed that 9 TMDLs describe such an 

approach.65 For example, experts reported that a Connecticut TMDL 

for phosphorus, approved by EPA in 2005, does not describe how 

monitoring data are to be used to assess progress toward water 

quality standards or to adjust the TMDL if implementation actions are 

found to be ineffective. Because the TMDL focuses only on 

phosphorus, a plant nutrient and chemical pollutant, one of the 

experts said that using monitoring data to assess progress toward the 

water body’s designated uses is particularly important because such 

data could show that even while concentrations of phosphorus are 

declining, additional actions may be needed to attain the water body’s 

designated uses of providing fish habitat and recreation. A 

Connecticut water quality official reported that for this TMDL, the 

official does not know whether point and nonpoint pollutant loads in 

the water body have changed or whether wasteload and load 

allocations have been met.

 

65Of the 18 TMDLs with a monitoring plan, experts disagreed about whether 1 of them 

describes an adaptive approach.
 

Page 45 GAO-14-80 EPA’s TMDL Program

In reviewing EPA’s guidance on approvable TMDLs and how regional 

offices are to apply the 11 TMDL elements, we found that the guidance 

did not contain some key features and that some of these 11 elements 

are vague or optional, which has led EPA’s regional offices to apply the 

elements in different ways and to approve TMDLs of variable quality. The 

11 elements for approvable TMDLs described in EPA’s guidance 

generally reflect the agency’s interpretation of TMDL development 

requirements under existing regulations, according to EPA’s guidance. In 

our review, we found that EPA’s guidance does not include two key 

features—specifically, those that help ensure that TMDLs accurately 

identify and address causes of impairment with respect to a designated 

use or uses. First, the guidance does not specify that a TMDL should 

provide evidence that impairment is caused by a stressor or stressors for 

which the TMDL is being developed. Rather, according to the guidance, a 

TMDL need only identify a given pollutant. Second, although guidance 

states that a TMDL must provide evidence that pollutant reductions will 

meet numeric targets, it does not specify that a TMDL is to provide 

evidence that addressing the given stressor or stressors will be sufficient 

for a water body to attain its designated uses. Because these key 

features are not explicitly called for in EPA’s guidance, chemical, 

physical, and biological stressors other than the pollutant identified in the 

TMDL may go unaddressed—unless additional TMDLs are developed for 

the water body—even if a numeric water quality target for the identified 

pollutant is met.66

EPA officials told us that the agency cannot include additional features in 

their guidance without issuing new regulations. Through its 2000 rule, 

EPA had planned to include additional features by conditioning TMDL 

approvals on more-rigorous requirements but withdrew the rule before its 

effective date. Instead, the agency developed guidance in 2002 for states 

 

66EPA has a process to accommodate a nonchemical approach to water body 

assessment and listing, but it appears to be underused by states, according to our 

analysis. States may list water bodies impaired by nonchemical stressors as category 4c 

(water quality is impaired by something other than a pollutant, such as a dam), as 

opposed to category 5 (water quality is impaired, and the water body is waiting for a TMDL 

to be developed). Of water bodies nationwide, about 1,000 were listed as category 4c in 

recent integrated reports out of about 128,000 total assessed water bodies.

EPA’s TMDL Guidance for 

Implementing Regulations 

Does Not Contain Some 

Key Features
 

Page 46 GAO-14-80 EPA’s TMDL Program

and EPA regions to apply in implementing its existing regulations.67

In addition, 3 of EPA’s 11 elements in its TMDL guidance—those for 

(1) implementation, (2) reasonable assurances, and (3) a monitoring plan 

to track TMDL effectiveness—are either vague or stated as options (e.g., 

EPA encourages an implementation plan, EPA recommends inclusion of 

a monitoring plan) and are therefore subject to varying interpretation on 

the part of states developing a given TMDL and the regional offices 

applying the elements in approving TMDLs. Our analysis shows that 

EPA’s regional offices do not apply the elements of the agency’s existing 

guidance consistently. Specifically, several EPA regions have interpreted 

the guidance as calling for key features in state-developed TMDLs, while 

the remaining regions have not. The vagueness of certain elements in 

EPA’s TMDL guidance—coupled with the absence of key features—

According to EPA officials, the guidance contains weaker versions of 

many of the same elements included in the 2000 rule, and they have not 

reinitiated rulemaking, both because the agency wanted more time to 

assess the effectiveness of existing regulations and because rulemaking 

is costly and time-consuming. But because the guidance does not contain 

certain features, states may not always have clear direction to develop 

TMDLs containing key features that can help water bodies attain water 

quality standards. Moreover, guidance does not have the force of 

regulation, and states can choose which and how much information to 

include under the 11 elements as currently stated. All three of the experts 

commented that TMDL development is a complex and costly endeavor 

and that developing TMDLs that do not contain key features—such as 

accurately identifying the causes of water body impairment—can waste 

effort and the limited funds available for the task. Absent the force of 

regulations to direct states to develop TMDLs containing key features, 

TMDLs are likely to continue to do little to attain water quality standards. 

Yet neither EPA’s existing guidance nor the agency’s 2013 long-term 

vision for the TMDL program has the detail on key features that can 

provide such direction.

 

67After EPA withdrew the rule in 2002, it conducted dozens of studies evaluating and 

describing characteristics of TMDLs that enable water bodies to attain water quality 

standards. According to EPA officials, these studies were meant to provide information 

and guidance to states, and certain EPA regions applied study findings in their decisions 

to approve or disapprove TMDLs. EPA has also developed draft guidance, which was not 

final at the time of our review, outlining situations that may warrant TMDL revision, such 

as monitoring results showing that TMDL implementation is not achieving anticipated 

pollution reductions.
 

Page 47 GAO-14-80 EPA’s TMDL Program

results in regional offices’ inconsistently interpreting what a TMDL is to 

contain and approving TMDLs of variable quality. EPA headquarters, 

however, has not worked with the regions to apply existing guidance 

consistently or to develop specific criteria on which to base TMDL 

approvals, as some regions do. EPA headquarters officials told us they 

have not done so because of differences among states’ programs, 

including that some states have been under pressure from consent 

decree schedules to develop a certain number of TMDLs by specific 

dates. Nevertheless, without specific criteria on which to base TMDL 

approvals, some EPA regions are likely to continue to approve TMDLs in 

which the quality or quantity of information is insufficient to help water 

bodies attain water quality standards.

EPA’s element for implementation encourages states to develop TMDL 

implementation plans but existing regulations do not require such plans or 

detail the information they should contain.68

When a TMDL is developed for waters impaired by both point and 

nonpoint sources, EPA guidance states that a TMDL should provide 

For example, the guidance 

describing the element does not specify that implementation plans should 

include information such as who must undertake what projects to reduce 

pollution and at what locations these projects are to be put in place. Our 

analysis showed that EPA’s regional offices vary in how they interpret this 

implementation element. Officials at most regional offices (6 of 10) told us 

they give little scrutiny to whether states include formal implementation 

plans in TMDLs. For example, Region 3 officials told us they do not 

review or approve implementation plans since EPA regulations do not 

require them. They said that most states do not submit such plans. On 

the other hand, officials from 4 of the 10 regional offices told us they 

encourage states to produce implementation plans or ask that states do 

so, particularly for TMDLs involving nonpoint source pollution. Region 2 

officials, for example, told us they have asked states to complete 

implementation plans and that the office reviews and comments on these 

plans. The officials said that information in implementation plans helps 

them determine whether projects to control nonpoint source pollution will 

be implemented.

 

68See 40 C.F.R. §§ 130.7(c), 130.2(i) (2013) (EPA’s TMDL regulations). A court has held 

that neither the Clean Water Act nor EPA regulations define TMDLs as including an 

implementation plan. Sierra Club v. Meiburg, 296 F.3d 1021, 1030-31 (11th Cir. 2002). 

See also Amigos Bravos v. Green, 306 F. Supp. 2d 48, 57 (D.D.C. 2004).

Implementation

Reasonable Assurances
 

Page 48 GAO-14-80 EPA’s TMDL Program

reasonable assurances that actions to control nonpoint source pollution 

will achieve expected load reductions. This information is necessary for 

EPA to determine that TMDLs have been set at levels sufficient to attain 

water quality standards. Nevertheless, EPA’s element for reasonable 

assurances does not describe the type of information needed to 

demonstrate that projects to reduce nonpoint source pollution will achieve 

expected load reductions. For example, the guidance describing the 

element does not state that a TMDL is to detail any available regulatory 

authority over nonpoint source pollution or identify landowners who are 

willing to implement needed projects. Without such specificity, EPA has 

little assurance that projects to reduce nonpoint source pollution will in 

fact be implemented.

We found that the regional offices vary in their review of the reasonable 

assurances element, with most regions (7 of 10) asking for little to no 

information on demonstrating that load reductions for nonpoint source 

pollution will occur. Officials from several regional offices told us they play 

a limited role in encouraging states to demonstrate reasonable 

assurances, although, according to EPA headquarters officials, EPA is 

beginning to put greater emphasis on demonstrating reasonable 

assurances in TMDLs. Officials from one regional office explained that 

many states lack data from which to develop reasonable assurances and 

that states without authority over nonpoint source pollution find it difficult 

to prove that sources of such pollution will take action to implement a 

TMDL. In the absence of specific guidance from EPA headquarters, 

officials from one regional office said that they encourage states to do the 

best they can to demonstrate reasonable assurances and that they do not 

reject TMDLs if reasonable assurances have not been demonstrated, in 

part because they do not have the resources to develop TMDL 

themselves.

Conversely, officials from Regions 1, 5, and 9 told us they ask for 

substantial information demonstrating that load reductions for nonpoint 

sources will actually occur. For example, in describing a decision to 

withdraw approval of a TMDL for Lake Champlain in Vermont, Region 1 

officials explained that they expect reasonable assurances to show 

quantitative reductions anticipated from specific projects to reduce 

nonpoint source pollution and that they expect regulatory or other 

mechanisms to be in place to ensure compliance with the actions and 

reductions called for in the TMDL. In addition, Region 5 officials told us 

that, as part of providing reasonable assurances that nonpoint source 

pollution will be reduced, they ask states to document specific state and 

local regulatory authority over such pollution. By calling for this type of 
 

Page 49 GAO-14-80 EPA’s TMDL Program

information during TMDL development, the officials said that the region 

gains leverage it can call upon later in encouraging states to apply those 

authorities when a TMDL is implemented. EPA has acknowledged that 

the regional offices vary in how exacting they are when reviewing 

reasonable assurances.

EPA’s monitoring plan element recommends that TMDLs include plans 

for monitoring but does not specify that such plans should include 

indicators reflecting biological conditions or adaptive approaches for 

TMDL revision in light of monitoring results. We found that EPA’s regional 

offices again vary in how they interpret and apply the monitoring plan 

element. Officials at most regional offices (7 of 10) told us they do not ask 

for TMDLs to include much, if any, information about monitoring. For 

example, Region 6 officials told us monitoring information is not a focus in 

their review of TMDLs and that only about 1 percent of TMDLs they 

review contain monitoring plans. On the other hand, officials in the other 

three regions ask for monitoring plans to provide assurance that TMDLs 

will lead to improved water quality as intended. For example, Region 8 

officials told us that they ask for monitoring plans for a handful of TMDLs, 

particularly for those in which a high degree of uncertainty exists about 

proposed pollution limits or other elements. They said that asking for a 

monitoring plan gives some assurance that a state will examine whether 

projects to control pollution are working as predicted and will adjust a 

TMDL if needed.

State TMDL coordinators reported that many factors EPA identified as 

helpful for effective TMDL implementation were often not in place in the 

long-established TMDLs they reviewed. EPA has identified a number of 

factors associated with effective TMDL implementation—that is, factors 

that help state TMDL coordinators and other stakeholders take actions, 

prescribed in TMDLs, that ultimately result in attainment of water quality 

standards. State TMDL coordinators reported that many factors, including 

those viewed as most helpful, were often not in place. Some factors are 

absent because EPA has not always asked states to make such factors a 

priority when funding TMDL implementation, and others—including those 

viewed as most helpful for implementation—are beyond EPA’s and 

states’ existing authorities to put in place, according to state TMDL 

coordinators.

Monitoring Plan

Factors Reported as 

Facilitating the 

Implementation of 

Long-Established 

TMDLs, Particularly 

Those for Nonpoint 

Source Pollution, Are 

Often Not in Place
 

Page 50 GAO-14-80 EPA’s TMDL Program

Through its studies and state conferences on TMDLs, EPA and the states 

have identified numerous factors associated with effective TMDL 

implementation, particularly TMDLs for nonpoint source pollution (since 

point sources are subject to regulation through permits and discharge 

limits). These facilitating factors can be organized into the following three 

categories: (1) those securing landowners’ and others’ participation in 

implementing TMDLs, (2) those providing external assistance to 

implement TMDLs, and (3) those improving states’ TMDL program 

functions. According to EPA documents, the agency expects some 

implementation actions to take place within 5 years of TMDL approval 

and all implementation actions to have taken place within 10 years of 

approval, and facilitating factors generally help states meet these goals. 

These facilitating factors—15 in all—can be organized as follows:

• Securing participation includes

• landowners willing to implement projects69

• landowners willing to implement projects in most-effective places

• landowners willing to implement most-effective projects

• citizen participation

• supportive local government leaders

• Providing external assistance includes

• funding enough or more than enough

• assistance from state nonpoint source program

• assistance from USDA

• assistance from state agricultural program

• assistance from EPA

• assistance from state or local planning agency

• assistance from state stormwater program

• Improving states’ TMDL program functions includes

• presence of TMDL implementation plan70

• higher funding priority for water bodies with TMDLs

• consolidation of TMDL responsibilities

 

69Projects prescribed in TMDLs may include landowners’ implementation of best 

management practices on agricultural land to reduce nutrient-laden runoff.

70According to EPA studies, detailed implementation plans are associated with TMDLs 

that have been implemented effectively. Thus, detailed implementation plans are both a 

key feature in TMDL development and a factor facilitating effective TMDL implementation. 

A Number of Factors 

Facilitate Effective TMDL 

Implementation 
 

Page 51 GAO-14-80 EPA’s TMDL Program

The first category of factors aims to secure participation by landowners 

and other stakeholders in implementing TMDLs. Without a federal 

regulatory framework similar to the one governing point source pollution, 

which requires that dischargers meet pollution limits or face penalties, 

most states generally must persuade landowners to implement best 

management practices to reduce nonpoint source pollution. For TMDL 

implementation to address nonpoint source pollution, an EPA study 

found, engaging owners of private land is crucial.71

In a 2007 study, EPA found that citizen-based groups, such as local 

watershed associations and supportive local governmental leaders, can 

have a positive effect on TMDL implementation.

According to the 

study, without landowners’ cooperation—including willingness to 

implement projects that are the most effective at reducing pollution in the 

places where they are most needed—projects to reduce such pollution 

may not be implemented.

72

The second category of factors aims to provide states with external 

assistance to implement TMDLs. EPA found in the 2007 study that 

implementing TMDLs requires adequate funding to undertake projects 

that reduce pollution. For example, states may target funds received as 

grants under EPA’s nonpoint source management program to implement 

best management practices on agricultural lands near water bodies 

subject to TMDLs, or states themselves may provide additional funding 

through other state water resource programs. According to a 2007 study, 

assistance from external agencies and programs (e.g., technical 

Citizen-based groups 

often have strong local support, are well informed on watershed issues, 

and have knowledge and experience that enables them to aid 

implementation, according to the study. When present, these citizenbased groups may lead in implementing a TMDL, such as by pursuing 

funding for projects and monitoring changes in water quality. Without a 

citizen-based group involved in TMDL implementation efforts, no entity 

may be in charge of implementing a TMDL. 

 

71Center for TMDL and Watershed Studies, TMDL Implementation: Characteristics of 

Successful Projects, Final Report, VT-BSE doc. no. 2006-0003 (Blacksburg, Va: 2006).

72Center for TMDL and Watershed Studies and Biological Systems Engineering, TMDL 

Implementation: Lessons Learned (Blacksburg, Va: 2007).

Securing Landowners’ and 

Others’ Participation in 

Implementing TMDLs 

Providing External Assistance 

to Implement TMDLs
 

Page 52 GAO-14-80 EPA’s TMDL Program

assistance) can also be a critical factor in TMDL implementation.73

The third category of factors aims to improve states’ TMDL program 

functions. In several recent conferences sponsored by EPA, state TMDL 

program managers identified ways to foster better TMDL implementation, 

including requiring or providing guidance for development of detailed 

implementation plans, administering funding to target water body 

restoration projects in areas where TMDLs have been developed, and 

consolidating TMDL development and implementation activities within the 

same state agency or program.

Particularly important is the involvement of agencies and programs—such 

as state nonpoint source programs, USDA programs, state agricultural 

agencies, EPA, state and local planning agencies, and state stormwater 

programs—whose participation may be necessary to improve water 

quality. 

Five states have laws or regulations requiring development of TMDL 

implementation plans, and five others provide guidance for such plans, 

according to a 2008 study. In a 2009 conference sponsored by EPA, state 

water quality program officials said that formal implementation plans 

enhance TMDL implementation for nonpoint source pollution by providing 

explicit direction for implementation, such as specific information on 

existing water quality conditions, necessary load reductions for pollutants, 

land areas likely to be contributing to pollution, programs that may help 

provide technical or financial assistance, best management practices and 

where they are to be implemented, and an accurate timeline over which 

implementation will be accomplished and water quality would improve.

In a 2009 conference, state TMDL program managers supported putting a 

high priority on using federal and state funding for reducing nonpoint 

source pollution to support TMDL implementation. Some states have 

 

73The 2007 EPA study found that external agency officials responsible for projects or 

activities related to TMDL implementation were generally unaware of the projects or 

activities identified in TMDLs that are needed to achieve water quality standards. The 

study noted that TMDLs are implemented by many stakeholders, but less than 50 percent 

of external agency stakeholders always or often had knowledge of TMDLs and the 

projects or activities needed to restore water bodies. These data underscore the 

importance of involving representatives from external agencies in the TMDL 

implementation process, to obtain their buy-in and encourage participants in their 

programs to implement best management practices or projects that can help improve 

water quality. EPA, Developing Effective TMDLs (2007).

Improving States’ TMDL 

Program Functions
 

Page 53 GAO-14-80 EPA’s TMDL Program

revised funding criteria under their nonpoint source management 

programs to give higher priority to projects designed to implement best 

management practices where a water body was already identified by the 

state as impaired and had an associated TMDL.

States have also identified the consolidation of their responsibilities for 

TMDL implementation and development activities as a factor that 

facilitates TMDL implementation. Some states have recently integrated 

their TMDL development and implementation responsibilities with their 

nonpoint source management programs, which fosters collaboration 

among staff working toward the same goal who have complementary 

knowledge and skills. Washington State, for example, merged its TMDL 

development and implementation programs into its Department of 

Ecology, and departmental staff reported that both programs are more 

effective. In Virginia, the state’s general assembly recently passed 

legislation that consolidated the agencies responsible for developing and 

implementing TMDLs.

In responding to our survey, state TMDL coordinators reported that the 

factors aiming to secure participation by landowners and other 

stakeholders are among the most helpful in implementing longestablished TMDLs. They also reported that external assistance, such as 

financial or technical assistance from a state nonpoint source program, is 

also very helpful, whereas factors improving state TMDL program 

functions were sometimes helpful. The results of our survey, however, 

showed that many factors, including those viewed as most helpful, were 

often not in place for long-established TMDLs (see fig. 6).74

 

74Appendix IV presents the full results of our survey, including the helpfulness of two 

implementation factors—land development and land retirement—that state TMDL 

coordinators told us were less helpful than the implementation factors we discuss in the 

body of this report.

State TMDL Coordinators 

Reported That Many 

Factors, Including Those 

Viewed as Most Helpful, 

Were Often Not in Place 

for Long-Established 

TMDLs
 

Page 54 GAO-14-80 EPA’s TMDL Program

Figure 6: Factors Facilitating TMDL Implementation and Extent to Which They Were Present in and Considered Helpful for 

Long-Established TMDLs

Note: “Present” (light blue bars) denotes the percentage of long-established TMDLs in which the 

given factor on the y-axis was present during implementation of the TMDL in question. “Considered 

helpful” (teal bars) denotes the percentage of these long-established TMDLs in which the state TMDL 
 

Page 55 GAO-14-80 EPA’s TMDL Program

coordinators responding to our survey indicated that the factor either was helpful (if present) or (if 

factor was not present or TMDL was not yet implemented) would have been or would be helpful in 

implementing the TMDL in question. In general, estimates have a margin of error of no more than 

12 percent. For reporting purposes, we describe a factor as helpful (or less helpful) on the basis of 

the percentages of long-established TMDLs for which state coordinators responding to our survey 

identified that factor as helpful or less helpful in TMDL implementation.

Virtually all state TMDL coordinators reported that factors aiming to 

secure landowners’ and others’ participation in implementing longestablished TMDLs are among the most helpful but, they reported, these 

factors were generally absent from about two-thirds of long-established 

TMDLs, and where they were present, they were not always present to an 

extent needed for effective TMDL implementation.75

Specifically, state TMDL coordinators told us that landowners were willing 

to implement projects, including practices most effective at reducing 

pollution and in the locations where they were most needed, for about 

one-third of long-established TMDLs.

For example, state 

coordinators reported that landowner willingness to implement projects 

was considered helpful in TMDL implementation for 98 percent of longestablished TMDLs. Similarly, according to state TMDL coordinators, 

assistance from other stakeholders was considered helpful: the 

coordinators reported that the assistance of citizen-based groups was 

considered helpful for 97 percent of long-established TMDLs and that the 

assistance of local government leaders was considered helpful for 

93 percent of long-established TMDLs. Yet factors such as these were 

often not present.

76

 

75Our survey asked if state TMDL coordinators found specific factors very helpful, 

somewhat helpful, not helpful, or not applicable for each of 191 TMDLs. For a given TMDL 

factor, “considered helpful” denotes the percentage of these long-established TMDLs in 

which a survey respondent indicated that the factor either was helpful (if present) or (if 

factor was not present or TMDL was not yet implemented) would have been or would be 

helpful in implementing the TMDL in question (see app. IV).

For example, officials with Idaho’s 

Department of Environmental Quality allocated nonpoint source funds to 

a restoration project to reduce stream bank erosion and sediment in a 

particular creek because the landowner was willing to install a gate to 

redirect water flow and alter the streambed to help reestablish the banks. 

76State TMDL coordinators responding to our survey reported that landowners were 

willing to (1) implement best management practices for 36 percent of long-established 

TMDLs (the 95 percent confidence interval for this estimate is [24, 49]), (2) implement the 

most effective best management practices for 35 percent of long-established TMDLs, and 

(3) implement best management practices in the most-effective places for 33 percent of 

long-established TMDLs.

Factors Securing Landowners’ 

and Others’ Participation Are 

Always Helpful but Are Often 

Not in Place 
 

Page 56 GAO-14-80 EPA’s TMDL Program

The creek where these actions were taken, however, contributed 

relatively little pollution to the larger impaired watershed. According to a 

local conservation district official, other projects the district wanted to 

pursue, which would have had a much greater benefit in the watershed, 

stalled because landowners at those locations that contributed pollution 

had not agreed to implement the proposed projects because they lacked 

agricultural value. Moreover, state TMDL coordinators reported that 

relatively small proportions of long-established TMDLs had enough 

landowners who were willing to implement projects to achieve load 

allocations called for in these TMDLs. For example, landowners had 

implemented all needed best management practices for 1 percent of longestablished TMDLs, and landowners had implemented more than half of 

needed best management practices for 19 percent of long-established 

TMDLs. For 79 percent of long-established TMDLs, landowners had 

implemented half or less than half of needed best management 

practices.77

In addition, state TMDL coordinators reported that citizen-based groups 

assisted in implementing 54 percent of long-established TMDLs and that 

local government officials were supportive in implementing 36 percent of 

long-established TMDLs. For example, citizen-based groups are key to 

implementing many TMDLs in Pennsylvania, according to officials from 

the state’s Department of Environmental Protection. Volunteers we met 

with from one stream restoration association—consisting of residents in a 

community directly affected by drainage from an abandoned mine—have 

helped establish and maintain treatment systems that remove metals and 

neutralize acidic water draining from the mine.78

 

77One state TMDL coordinator did not indicate in our survey the extent to which best 

management practices were installed. Other factors, such as limited funding, could also 

help explain the limited extent to which landowners had implemented all necessary best 

management practices. 

State officials told us, 

however, that if this organization had not been involved, they would not 

have put a high priority on funding implementation of this TMDL because 

they would have had little confidence that needed treatment systems 

would have been built or maintained.

78Treatment systems for drainage from abandoned mines, which usually consists of acidic 

water, channel the drainage into ponds, where the acidic water is neutralized through 

contact with limestone, and metal pollutants are removed.
 

Page 57 GAO-14-80 EPA’s TMDL Program

State TMDL coordinators responding to our survey reported that factors 

providing external assistance to implement projects to reduce nonpoint 

source pollution for long-established TMDLs are also helpful. Specifically, 

state TMDL coordinators reported that the provision of funding was 

considered helpful in implementing 97 percent of long-established 

TMDLs. Involvement of agencies other than the one responsible for 

implementing a particular TMDL was also considered helpful. For 

example, technical or financial assistance from state nonpoint source 

pollution programs was considered helpful in 95 percent of longestablished TMDLs, according to our survey respondents, and the 

assistance of other external agencies ranged from 67 percent (for state 

stormwater programs)79

Specifically, state TMDL coordinators told us that enough funding was 

available to implement best management practices for 14 percent of longestablished TMDLs. The need for enough funding is shown by one project

in Pennsylvania, where funding was available from two sources—grants 

under EPA’s nonpoint source management program and the state’s 

cleanup program for nonpoint source pollution—for projects aimed at 

reducing the amount of phosphorus entering a lake used primarily for 

recreation. During the first year after funding was received, best 

management practices that were implemented brought the lake within 

25 percent of the load allocation for phosphorus established in the TMDL. 

With another year’s funding received, Pennsylvania water quality officials 

expect other projects to be implemented that will enable the lake to meet 

its load allocation for phosphorus.

to 91 percent (for state agriculture programs). 

With the exception of assistance from state nonpoint source pollution 

programs, however, such factors were present for less than half of longestablished TMDLs.

State TMDL coordinators also reported that involvement from external 

agencies or programs varied by agency or program. For example, 

according to these coordinators, state nonpoint source management 

programs helped with implementation for 70 percent of long-established 

TMDLs. State TMDL coordinators reported that other agencies or 

programs (e.g., EPA, USDA, state agricultural programs, state and local 

planning agencies, and state stormwater management programs) helped 

with the implementation of less than half of long-established TMDLs.

 

79The 95 percent confidence interval for this estimate is (52, 82).

Factors Providing External 

Assistance Are Almost Always 

Helpful but Are Often Not in 

Place 
 

Page 58 GAO-14-80 EPA’s TMDL Program

State TMDL coordinators reported that one factor aiming to improve 

program function was considered helpful in implementing projects to 

reduce pollution for nonpoint sources for most long-established TMDLs, 

and two others were considered helpful for about half of them. 

Specifically, according to state TMDL coordinators, a formal TMDL 

implementation plan was considered helpful for 89 percent of longestablished TMDLs. Coordinators reported, however, that less than half 

(44 percent) of long-established TMDLs have implementation plans to 

identify who must undertake what actions to reduce pollution and on what 

land areas such actions are to be taken to restore impaired water bodies. 

For example, a TMDL for a largely rural watershed in Pennsylvania that 

we visited has an implementation plan that has, since 2007, resulted in 

implementation of best management practices at 130 different locations 

within the watershed, including one 300-acre farm that has terraced its 

land and implemented other best management practices to minimize soil 

loss into neighboring streams.

On the other hand, two factors—funding priority and consolidation of 

TMDL responsibilities in a single agency—were generally present, but 

state TMDL coordinators considered them helpful for about half of the 

long-established TMDLs. For example, in determining how to allocate 

grant funding from EPA’s nonpoint source management programs to 

reduce nonpoint source pollution, state TMDL coordinators reported that, 

for 93 percent of long-established TMDLs, they assigned water bodies 

associated with a TMDL a higher priority for funding than water bodies 

without a TMDL. State TMDL coordinators reported that allocating grant 

funding in this way was helpful for about half (54 percent) of longestablished TMDLs.80 Similarly, state TMDL coordinators reported that for 

92 percent of long-established TMDLs, TMDL development and 

implementation responsibilities were consolidated within a single state 

agency. State TMDL coordinators reported that the consolidation of 

TMDL programs within the same agency was considered helpful for about 

half (54 percent) of long-established TMDLs in improving water quality in 

the water body to which the TMDL applied.81

 

80The 95 percent confidence interval for this estimate is (41, 66).

81The 95 percent confidence interval for this estimate is (41, 67).

Factors Improving State 

Program Functions Were 

Sometimes Helpful and More 

Often in Place than Other 

Factors 
 

Page 59 GAO-14-80 EPA’s TMDL Program

Some of the factors facilitating TMDL implementation are not often in 

place, either because (1) EPA has not always asked states to make such 

factors a priority when funding TMDL implementation projects or, 

according to state TMDL coordinators, (2) implementing certain TMDLs is 

a low priority. Two other factors, which are those viewed as most helpful, 

are generally beyond EPA’s and states’ existing authorities to put in 

place. Specifically, states (1) may find it difficult to convince landowners 

that actions need to be taken on their properties to reduce nonpoint 

source pollution and (2) may have limited ability to provide funding to 

implement more than a small fraction of TMDLs.

When making grants to states through its nonpoint source management 

or water pollution control programs, EPA has not always asked states to 

make various factors facilitating implementation a priority in selecting 

TMDL implementation projects for funding, particularly for the relatively 

older TMDLs in the scope of our review. Specifically, EPA headquarters 

officials said that in the past the agency rarely asked states to focus on 

more specific conditions, such as demonstrating local stakeholder 

involvement, gaining external assistance, or developing formal TMDL 

implementation plans. Recently, however, EPA has taken steps to target 

nonpoint source management grants toward projects demonstrating some 

of these factors—for example, encouraging states to fund projects that 

target nonpoint source management grant funds to water bodies with 

TMDLs. In 2013, EPA issued new guidance on the use of these grants, 

encouraging states to fund projects with local stakeholder involvement, 

external agency assistance, and formal TMDL implementation plans 

containing specific information on locations likely to be contributing to 

pollution and the projects needed to reduce such pollution.82

 

82EPA, Nonpoint Source Program and Grants Guidelines for States and Territories

(Washington, D.C.: April 2013).

For nonpoint 

source management grants, states must use 50 percent of their annual 

grant funding for implementing plans in watersheds with impaired waters; 

these plans may identify the presence of some of these factors. Although 

the guidance targets funding to where some of these factors may be 

present, the guidance does not require states to follow recommendations 

for selecting projects to fund or include these factors among 

programmatic conditions on annual nonpoint source grants. Without 

incorporating these factors as conditions into annual grants, regarding 

funding specific projects, rather than only plans, EPA may not be 

Some Factors Associated 

with Effective TMDL 

Implementation Are Often 

Not In Place
 

Page 60 GAO-14-80 EPA’s TMDL Program

targeting its limited funds toward TMDL implementation projects that 

exhibit factors facilitating effective TMDL implementation or ensuring that 

the funds are spent on a mix of projects likely to help attain water quality 

standards. Without such targeting, it is likely that the limited improvement 

in attaining water quality standards reported by state coordinators, 

especially for water bodies with associated TMDLs for nonpoint source 

pollution, will continue.

In addition, certain long-established TMDLs may not be a high priority for 

implementation, and circumstances may have discouraged EPA and 

states from focusing on factors facilitating successful TMDL 

implementation. EPA and state officials said that because many TMDLs 

were developed in response to schedules laid out in court-ordered 

consent decrees—not necessarily because they applied to water bodies 

at high priority for restoration—implementing many of these TMDLs is not 

a high priority and that states may therefore be reluctant to invest limited 

resources in drawing up implementation plans for TMDLs they do not plan 

to implement. For example, officials from Virginia’s Department of 

Environmental Quality told us that about one-third of TMDLs developed in 

response to consent decrees have implementation plans, whereas a 

greater share of TMDLs developed without the pressure of a consent 

decree have implementation plans. On the other hand, where consent 

decrees did not drive TMDL development, TMDLs have sometimes 

reflected certain factors that facilitate implementation. For example, 

according to regional officials, states in EPA’s Region 5 developed their 

TMDL programs without constraint from court-ordered schedules, and the 

region has placed strong emphasis on TMDLs that can be implemented. 

As a result, the region’s TMDLs typically contain details that facilitate 

implementation, including identification of individual sources of nonpoint 

pollution and the specific actions that each needs to undertake to achieve 

required load allocations. According to agency officials, EPA’s long-term 

vision, which the agency plans to implement in fiscal year 2014, seeks to 

allow states to rank TMDLs for development and implementation now that 

states are emerging from several decades of consent-decree-driven time 

frames and have more flexibility in allocating their limited resources.

Certain other factors, however, including those state TMDL coordinators 

considered most helpful, are beyond EPA’s and states’ existing 

authorities to put in place, particularly for nonpoint source pollution. 

Specifically, the Clean Water Act addresses nonpoint pollution through 

largely voluntary means and EPA does not have direct authority to require 

landowners to implement activities to reduce nonpoint source pollution. 

As such authority is absent and where additional effective state authority 
 

Page 61 GAO-14-80 EPA’s TMDL Program

is also limited, the inability to find enough landowners willing to implement 

projects to reduce nonpoint source pollution has resulted in limited 

improvements in water quality for waters impaired by such pollution, 

according to our survey results. The act does not provide states with the 

authority to require landowner implementation of projects to control 

nonpoint source pollution, and state TMDL coordinators cited a lack of 

authority as the main reason why nonpoint source TMDLs had not been 

implemented. For example, of the 67 state TMDL coordinators who 

submitted narrative responses to our survey, 46 (69 percent) said that 

long-established TMDLs faced implementation challenges because of the 

inability to secure landowners’ and others’ participation, such as by not 

having authority over nonpoint sources. One survey respondent stated 

that the state had no effective way to compel landowners to implement 

the best management practices called for in a TMDL, and as a result, no 

practices prescribed by that TMDL had been implemented in the 10 years 

since EPA approved it. EPA officials concurred with the state coordinator 

results, saying that the agency works within the authority it has to 

encourage landowners to carry out projects. The officials said that the 

Clean Water Act does not give the agency or states the authority to 

regulate nonpoint source pollution. As noted by some congressional 

members in 1987, when the act was amended to create the section 319 

program, the program would be revisited if the voluntary approaches did 

not significantly address nonpoint source pollution.

For those states with some specific authority over nonpoint source 

pollution, according to state coordinators, the authority may be limited in 

scope or not routinely used. For example, nearly 1,000 Pennsylvania 

TMDLs identify sediment as impairing water quality, and runoff from farms 

is the source of sediment pollution for many of these TMDLs. 

Pennsylvania law requires that all farms have a plan to control or reduce 

sediment entering waterways from fields and animal use areas over a 

certain threshold. Nevertheless, officials said, the state’s Department of 

Environmental Protection has never enforced this law and required farms 

to have, and implement, these plans, even though the law has been in 

effect for more than 40 years. The department’s manager of conservation 

programs told us that the department has not been strict with the 

agricultural community over the years. Of the nearly 1,000 portions of 

water bodies identified as impaired by sediment, 2 have been restored, 

according to data from EPA’s Assessment, TMDL Tracking and 

Implementation System.

EPA and states also are limited by their respective budgets, and, as a 

result, they cannot provide funding to ensure implementation of a 
 

Page 62 GAO-14-80 EPA’s TMDL Program

sufficient number of best management practices, according to state 

TMDL coordinators. Since section 319 was added to the Clean Water Act 

in 1987, EPA has awarded about $150 million per year, on average, in 

grants to the 50 states and others (the District of Columbia, U.S. 

territories, and Native American tribes) to address the primary cause of 

pollution in more than 33,000 water bodies. Most (86 percent) of longestablished TMDLs addressing nonpoint source pollution did not have 

adequate funding, according to state TMDL coordinators, to implement 

the best management practices the TMDLs called for. State TMDL 

coordinators reported that although TMDL implementation is a priority for 

funding under the state’s nonpoint source management grants, funding is 

typically not in proportion with the amount needed to implement projects 

in all areas or at all specific sites where they are needed to reduce 

nonpoint source pollution and enable water bodies to one day attain water 

quality standards. Moreover, 42 of 67 (63 percent) state TMDL 

coordinators reported in narrative responses that limited availability of 

funding impeded TMDL implementation. EPA officials said that they work 

with available funding to leverage funding from other agencies, such as 

USDA grants, for conservation projects in the areas subject to TMDLs 

and have begun to work with states under the 2013 long-term vision to 

prioritize TMDLs for development and implementation.

EPA has worked with the states to develop more than 50,000 TMDLs 

over the past two decades, and these TMDLs have proven useful in 

identifying and reducing pollutant loads in many waters impaired by 

pollutants from point sources. Yet progress toward the Clean Water Act’s 

goals of restoring and maintaining “the chemical, physical, and biological 

integrity of the nation’s waters”—including designated uses of fishing, 

swimming, and drinking—has stalled, largely because nonpoint source 

pollution has not been controlled. As our survey of state TMDL program 

coordinators indicates, few TMDLs have been implemented for nonpoint 

source pollution, and for those that have been implemented, progress has 

generally been incremental, in large part because of long-recognized 

limits to nonpoint source authority and funding. In 1987, when Congress 

amended the Clean Water Act to create a voluntary, incentive-based 

program to address nonpoint source pollution, Members of Congress also 

indicated that this provision was a starting point, subject to change if the 

reliance on voluntary participation did not significantly improve water 

quality. As reported by state TMDL coordinators, the absence of two key 

factors—specifically, legal authority and sufficient funding—has generally 

stymied the implementation of TMDLs meant to curtail nonpoint source 

pollution. The approach for abating nonpoint source pollution established 

Conclusions 
 

Page 63 GAO-14-80 EPA’s TMDL Program

by the 1987 Clean Water Act amendments has not shown much progress 

toward achieving the goals of the act and likely will not do so in the 

foreseeable future. Consequently, more than 40 years after enactment of 

the Clean Water Act, and more than 25 years after Congress amended it 

to institute a program to control nonpoint source pollution, a majority of 

our nation’s waters continue to be impaired. The preamble to EPA’s 2000 

rule recognized this fact, stating that although significant progress had 

been made—particularly in stemming pollution from point sources—major 

challenges remained for addressing nonpoint source pollution. EPA 

officials have said that they are working within existing authorities to make 

TMDL implementation a priority and to target and leverage funding; even 

so, many years will be needed to attain water quality standards. Without 

changes to the program’s voluntary approach to implement projects in 

waters impaired by nonpoint source pollution, the act’s goals are likely to 

remain unfulfilled.

Whether or not changes are made to the Clean Water Act, our review has 

uncovered several shortcomings in EPA’s current implementation of the 

TMDL program, as follows:

• First, the experts’ review shows that, where developed properly, 

TMDLs can be useful tools to identify impaired waters and plan 

actions to reduce water pollution. Yet the 11 elements in EPA’s 

guidance, which generally reflect the agency’s interpretation of TMDL 

development requirements in existing regulations, do not include 

certain features identified by the 2001 NRC report and several EPA 

studies as key for TMDLs to help water bodies attain water quality 

standards, such as comprehensive identification of impairment and 

plans to monitor water bodies to verify that water quality is improving. 

EPA officials said that the agency cannot require TMDLs to include 

additional features without issuing new regulations. Unless key 

features are incorporated into the agency’s regulations—upon which 

future guidance can be based—states may include them in TMDLs 

only sporadically, if at all. Furthermore, without the force of regulations 

to direct states to develop TMDLs containing key features, TMDLs are 

likely to do little to attain water quality standards, particularly the 

designated uses of fishing, swimming, and drinking. EPA withdrew the 

2000 rule before its effective date, and EPA officials have not taken 

action to reinitiate it, they said, both because the agency had wanted 

more time to assess the effectiveness of existing regulations and 

because rulemaking is costly and time-consuming. Nevertheless, 

TMDLs without certain key features may be unlikely to help water 
 

Page 64 GAO-14-80 EPA’s TMDL Program

bodies attain water quality standards and may potentially waste 

states’ limited resources.

• Second, because some elements in the agency’s existing 11-element 

guidance for TMDL development are either vague or stated as 

options, EPA’s regional offices do not apply them consistently. A few 

regional offices have demonstrated, however, that asking states to 

provide more-detailed information about pollution causes and 

abatement actions provides greater assurance that TMDLs, if 

implemented, can achieve tangible water quality results. In the 

absence of clear guidance from headquarters directing all regional 

offices to review TMDLs on the basis of specific criteria, EPA’s 

regional offices are unlikely to systematically ask states for more than 

the limited information described in the existing elements, including 

those that are vague or optional. As a result, some EPA regions may 

continue to approve TMDLs in which the quality or quantity of 

information is insufficient to help water bodies attain water quality 

standards, even if the TMDLs are implemented.

• Third, EPA has studied TMDL implementation and identified specific 

factors facilitating such implementation, but it has generally not placed 

on state grants conditions reflecting these factors for TMDL 

implementation plans and projects. In 2013, the agency issued 

guidance targeting nonpoint source management grant funds to states 

and projects that demonstrate some of these factors for effective 

TMDL implementation (e.g., targeting grant funds to projects where 

implementation plans have been developed and where external 

agency assistance is available). The guidance, however, neither 

requires states to follow these recommendations for selecting projects 

to fund, nor requires EPA regions to include these factors among 

programmatic conditions on annual nonpoint source grants. Without 

incorporating these factors as conditions into annual grants, the 

agency may neither target its limited funds toward effective TMDL 

implementation projects, nor ensure that the funds are spent on the 

mix of projects most likely to attain water quality standards or that they 

meet the purposes for which they are awarded.

• Fourth, the agency has little nationwide information to determine 

whether and to what extent TMDLs have been implemented or to 

what extent implemented TMDLs have helped impaired waters attain 

water quality standards. EPA recognizes that obtaining specific GIS 

data for TMDL implementation projects could help track the status of 

implementation efforts, and the agency has taken steps to gather 

some of these data. According to EPA officials, however, the agency 

has not required states to provide specific GIS data for TMDL projects 

funded in part by EPA that would enable it to link key pieces of such 

data in its own separate databases. Without consistently obtaining 
 

Page 65 GAO-14-80 EPA’s TMDL Program

from states GIS data in addition to water body names, EPA cannot 

integrate information on TMDL implementation projects and impaired 

water bodies across separate databases and cannot assess whether 

and to what extent water quality has been affected by TMDL 

implementation. Regardless, important data related to TMDL 

implementation are collected by USDA on conservation projects it 

funds and, under the 2008 Farm Bill, remain outside of EPA’s 

authority to obtain from USDA without landowners’ consent. Without 

access to data from landowners who participate in conservation 

programs funded by USDA in areas subject to a TMDL (e.g., on 

agricultural land adjacent to water bodies with TMDLs)—data 

including the location, type, and number of projects implemented 

under these programs—EPA cannot track actions taken to implement 

TMDLs or any subsequent changes in water quality associated with a 

core EPA program and a substantial federal investment.

To help ensure effective TMDL implementation in water bodies impaired 

by nonpoint source pollution and to hasten progress toward the Clean 

Water Act’s goals of restoring and maintaining the chemical, physical, and 

biological integrity of the nation’s waters, Congress should consider 

revising the act’s largely voluntary approach to restoring waters impaired 

by such pollution. Specifically, Congress could consider ways to address 

factors, such as limited authority, which currently impede attainment of 

water quality standards, particularly the designated uses of fishing, 

swimming, and drinking.

To enhance the likelihood that TMDLs support the nation’s waters’ 

attainment of water quality standards and to strengthen water quality 

management, we recommend that the Administrator of EPA take the 

following four actions:

• Develop and issue new regulations requiring that TMDLs include 

additional elements—and consider requiring the elements that are 

now optional—specifically, elements reflecting key features identified 

by NRC as necessary for attaining water quality standards, such as 

comprehensive identification of impairment and plans to monitor water 

bodies to verify that water quality is improving.

• To ensure more consistent application of existing TMDL elements and 

to provide greater assurance that TMDLs, if implemented, can 

achieve tangible water quality results, identify regional offices with 

criteria for interpreting and applying such elements in reviewing and 

approving state-developed TMDLs and issue guidance with more 

Matter for 

Congressional 

Consideration 

Recommendations for 

Executive Action
 

Page 66 GAO-14-80 EPA’s TMDL Program

specificity, directing all regional offices to follow the same criteria, 

including requesting that states provide more-detailed information 

about pollution causes and abatement actions.

• Place conditions on states’ annual use of nonpoint source 

management and water pollution control grants to ensure that the 

funds meet the purposes for which they are awarded and achieve 

greater reductions in nonpoint source pollution associated with TMDL 

implementation, such as by targeting funds to states and projects that 

incorporate factors needed for effective TMDL implementation (e.g., 

targeting grant funds to projects where implementation plans have 

been developed and where external agency assistance is available).

• Obtain missing data that currently impede EPA’s efforts to determine 

whether and to what extent TMDLs have been implemented or to 

what extent implemented TMDLs have helped impaired waters attain 

water quality standards by

• directing states to use and report specific GIS data when 

implementing projects to which TMDLs apply and

• requesting that USDA ask landowners who participate in 

conservation programs funded by the department in areas subject 

to a TMDL to disclose information on the location, type, and 

number of projects implemented under these programs.

We provided a draft of this report to the Administrator of the 

Environmental Protection Agency for review and comment. EPA provided 

written comments, reproduced in appendix V, in which the agency 

expressed general agreement with the report’s findings and partial 

agreement with its conclusions and recommendations. Overall, the letter 

cited agreement with the report’s characterization of the challenges facing 

EPA’s water quality-based programs and agreement in principle with the 

kinds of changes that would be able to increase success under the Clean 

Water Act. EPA did not comment on the matter for congressional 

consideration, agreed with one recommendation, agreed with the findings 

of another recommendation but did not agree to take the recommended 

action, and partially agreed with two other recommendations. EPA also 

provided separate technical comments, which we incorporated in the 

report as appropriate.

In response to our recommendation that EPA develop and issue new 

regulations requiring that TMDLs include additional elements, EPA stated 

that it agrees that broader implementation and monitoring requirements 

would be helpful and pointed out that the agency attempted to revise the 

TMDL regulations to include such provisions in 2000. EPA stated that 

Agency Comments 

and Our Evaluation
 

Page 67 GAO-14-80 EPA’s TMDL Program

since Congress prevented those regulations from going into effect, this 

recommendation might be better directed to Congress than to EPA. To 

help address the recommendation, EPA stated that it plans to continue its 

long-standing promotion of comprehensive watershed management well 

beyond the TMDL program. However, these plans do not include initiating 

a rulemaking. We note that while Congress temporarily prevented the 

2000 rule from going into effect, EPA ultimately withdrew the rule in 2002, 

stating that it needed more time to evaluate the effectiveness of existing 

regulations. In withdrawing the rule, EPA stated that the rule would need 

significant changes before it could serve as a blueprint for an efficient and 

effective TMDL program. As we describe in the report, key events have 

transpired since development of the rule that provide EPA and state and 

other water quality managers with a wealth of information on the 

characteristics of effective TMDLs. In addition, and as we reported, ample 

time has passed for EPA to evaluate the effectiveness of existing 

regulations and substantial data shows that EPA’s existing TMDL 

regulations—written nearly 30 years ago—do not go far enough to ensure 

they effectively support attainment of water quality standards. Specifically, 

the agency has gained new information on the characteristics of effective 

TMDLs. For these reasons, we continue to believe that EPA—with its 

expertise and decades of experience in water quality-based programs—

should prepare updated regulations for the TMDL program and create a 

blueprint for an effective TMDL program for the future. 

In response to our recommendation that EPA identify regional offices with 

criteria for interpreting and applying TMDL elements in reviewing and 

approving state-developed TMDLs and issue guidance with more 

specificity, directing all regional offices to follow the same criteria, EPA 

states that it will initiate a dialogue with its regional offices on overall 

TMDL review and approval guidance. EPA further stated that it would 

undertake this dialogue in 2014 and that this dialogue will consider the 

recommended changes in specificity and content that we raised. 

In response to our recommendation that EPA place conditions on states’ 

annual use of nonpoint source management and water pollution control 

grants to ensure that the funds meet the purposes for which they are 

awarded, EPA agreed with the recommendation as it relates to one of two 

grant programs, Section 106, saying that it will review the use of funds 

from one of two grant programs that we examined, and several others 

where our findings may be helpful, to address the recommendation. EPA 

stated that the agency is already implementing the recommendation for 

the second program, Section 319; however, we do not agree that this is 

the case. In particular, EPA stated that it has recently issued new 
 

Page 68 GAO-14-80 EPA’s TMDL Program

guidance for the nonpoint source program that substantially addresses 

much of GAO’s recommendation and that there is no value added in 

revising the guidance for the program. We note, however, that the 

guidance targets funds to watersheds where comprehensive planning has 

taken place, whereas we recommend that EPA further target funds to 

specific on-the-ground TMDL projects for which certain factors—those 

that facilitate effective implementation—have been confirmed. We do not 

agree that these are the same actions, as the existence of a watershed 

based plan does not mean that the projects ultimately chosen to 

implement the plan and the TMDLs within the watershed will, in fact, 

reflect those factors that we and EPA have identified as necessary for 

helping to attain water quality standards. For this reason, we continue to 

believe that EPA should place conditions on grants to states to ensure the 

presence of such factors. 

In response to our recommendation that EPA obtain missing data that 

currently impede its efforts to determine whether and to what extent 

TMDLs have been implemented or have helped impaired waters attain 

water quality standards, EPA stated that it generally agrees that it could 

direct states to use and report specific GIS data when implementing 

projects to which TMDLs apply. The agency disagreed with the second 

part of the recommendation, however, that it should request that USDA 

ask certain landowners—those participating in conservation programs 

funded by the department in areas subject to a TMDL—for permission to 

disclose information on the location, type, and number of projects 

implemented under these programs. EPA agreed that data on the location 

and type of USDA pollution control projects would be useful data for 

tracking implementation and evaluating water quality effects but urged 

GAO to direct this part of the recommendation to USDA. EPA stated that 

as currently written, the recommendation implies that EPA would use 

USDA data to assess individual actions to implement individual TMDLs. 

Recognizing that the state programs that develop TMDLs are partially 

funded by EPA and that many TMDL projects in waters impaired by 

agricultural runoff are also funded in part by EPA, we believe it is 

incumbent upon the agency to try to obtain data that it needs to evaluate 

the effectiveness of a key water quality program. The agency stated that it 

prefers to rely on states’ oversight and tracking programs to assess 

states’ collective progress in TMDL implementation, which may reflect 

data shared with the state by the department. We understand from our 

discussions with EPA and state officials, however, that this approach 

provides data aggregated at levels that are not precise enough to track 

actions taken to implement TMDLs. As we state in the report, without 

access to data on the location, type, and number of projects implemented 
 

Page 69 GAO-14-80 EPA’s TMDL Program

in areas subject to a TMDL, EPA cannot track possible changes in water 

quality associated with a core EPA program and a substantial federal 

investment. For these reasons, we continue to believe that—at the 

least—EPA should ask for these data from those who may be willing to 

provide it. 

As agreed with your offices, unless you publicly announce the contents of 

this report earlier, we plan no further distribution until 30 days from the 

report date. At that time, we will send copies to the Administrator of EPA, 

the appropriate congressional committees, and other interested parties. In 

addition, this report will be available at no charge on the GAO website at 

http://www.gao.gov. 

If you or your staff members have any questions about this report, please 

contact me at (202) 512-3841 or gomezj@gao.gov. Contact points for our 

Offices of Congressional Relations and Public Affairs may be found on 

the last page of this report. GAO staff who made major contributions to 

this report are listed in appendix VI.

J. Alfredo Gómez

Director, Natural Resources and Environment
Appendix I: Objectives, Scope, and 

Methodology

Page 70 GAO-14-80 EPA’s TMDL Program

The objectives of our work were to examine (1) the Environmental 

Protection Agency’s (EPA) and states’ responsibilities in the total 

maximum daily load (TMDL) program, (2) what is known about the status 

of long-established TMDLs, (3) the extent to which long-established 

TMDLs contain key features that enable attainment of water quality 

standards, and (4) the extent to which such TMDLs exhibit factors that 

facilitate effective implementation.

To conduct this work, we reviewed EPA reports and independent, peerreviewed reports on the status of TMDLs and assessments of TMDL 

implementation projects and activities. We interviewed EPA officials in the 

agency’s impaired waters and nonpoint source management programs. 

We also interviewed officials from the Association of Clean Water 

Administrators, National Association of Clean Water Agencies, and the 

Environmental Law Institute. In addition, we visited four states in two EPA 

regions to review the states’ responsibilities in developing and 

implementing TMDLs, as well as any challenges the states may have 

faced in doing so. We selected these regions and states on the basis of 

the number of TMDLs each state had developed, types of water pollution, 

differences in state authorities to implement TMDLs, and the extent of 

each state’s TMDL implementation efforts.

To examine EPA’s and states’ responsibilities in developing and 

implementing TMDLs, we reviewed documents and published reports to 

identify and describe the responsibilities of EPA and the states. Such 

documents and reports included relevant provisions of the Clean Water 

Act, including sections 303(d), 305(b), 319, and 402, which describe the 

responsibilities of EPA and the states with regard to identifying and 

restoring impaired waters. We reviewed EPA’s 1985 regulations and 1992 

amendments, which describe EPA’s implementation of its Clean Water 

Act requirements, as well as the agency’s 2002 “Guidelines for Reviewing 

TMDLs under Existing Regulations Issued in 1992.” We also reviewed 

EPA’s long-term vision for its impaired waters program under section 

303(d) of the Clean Water Act. We reviewed other relevant reports 

addressing responsibilities within the TMDL program, including a 2001 

report by the National Research Council (NRC) of the National 

Academies titled Assessing the TMDL Approach to Water Quality 

Management, which is the most recent effort undertaken by the National 

Academies to evaluate the TMDL approach to water quality management. 

We also reviewed a 2007 report by EPA’s Office of Inspector General 

titled Total Maximum Daily Load Program Needs Better Data and 

Measures to Demonstrate Environmental Results and a 2008 report by 

Appendix I: Objectives, Scope, and 

Methodology 
Appendix I: Objectives, Scope, and 

Methodology

Page 71 GAO-14-80 EPA’s TMDL Program

the Congressional Research Service titled Clean Water Act and Total 

Maximum Daily Loads (TMDLs) of Pollutants. 

To examine what is known about the status of long-established TMDLs, 

we used information from the Assessment, TMDL Tracking and 

Implementation System on the number of impaired water bodies subject 

to TMDLs and the types of TMDLs by source (point, nonpoint, mixed), 

pollutant, and cause of impairment. To assess the reliability of the data 

from this system, we (1) electronically tested required data elements, 

(2) reviewed existing information about the data and the system that 

produced them, and (3) interviewed agency officials knowledgeable about 

the data. We found these data to be sufficiently reliable for purposes of 

this report. In addition, we reviewed EPA reports that examined the status 

of TMDLs, including the following:

• FY2010 National Report on Implementing Total Maximum Daily Loads 

(TMDLs), EPA841-R-11-002 (March 2011)

• Analysis of TMDL Implementation Rates in EPA Region 5, EPA841-R09-005 (December 2009)

• John Hoornbeek et al., Implementing Total Maximum Daily Loads: 

Understanding and Fostering Successful Results (Kent, Ohio: Kent 

State University, December 2008).

• Developing Effective TMDLs: An Evaluation of the TMDL Process

(Washington, D.C.: 2007)

• Developing Effective Nonpoint Source TMDLs: An Evaluation of the 

TMDL Development Process (Washington, D.C.: January 2007).

To examine the extent to which long-established TMDLs contain key 

features needed to enable a water body to attain water quality standards, 

as well as to examine the extent to which long-established TMDLs exhibit 

factors facilitating effective implementation, we used the Assessment, 

TMDL Tracking and Implementation System database to select a 

generalizable, nationwide sample of 191 long-established TMDLs, which 

we defined to be those approved by EPA through December 31, 2007.1

 

1

The population of long-established TMDLs was 34,794. 

From this sample, we drew a random subsample of 25 TMDLs, which we 

asked three authors of the 2001 NRC report to review (see app. II). In 

addition, we used the whole sample of 191 long-established TMDLs in a 

survey of state TMDL coordinators on the water quality status associated 

with long-established TMDLs, such as whether and to what extent water 
Appendix I: Objectives, Scope, and 

Methodology

Page 72 GAO-14-80 EPA’s TMDL Program

quality had improved in the water body subject to the TMDL and whether 

water quality standards had been attained.

To examine the extent to which long-established TMDLs contain key 

features needed to enable a water body to attain water quality standards, 

we hired three water resource experts who had contributed to NRC’s 

2001 report. They reviewed our random subsample of 25 TMDLs drawn 

from our generalizable nationwide sample of 191 TMDLs. Unlike the 

sample as a whole, the subsample is not generalizable to all TMDLs, 

although it is an unbiased set that provides detailed examples of TMDL 

development in specific states and regions, which help illustrate 

challenges and successes in TMDL development. The 25 TMDLs in the 

subsample include TMDLs from all EPA regions except Region 2 and 

were approved by EPA from 1997 to 2007; see appendix III for additional 

information about these TMDLs.

We developed a questionnaire for the experts to use in examining the 

25 TMDLs, and we charged them with identifying those features that are 

most important, or key, if a TMDL is to enable a water body to attain 

water quality standards. We began by reviewing the 2001 NRC report and 

EPA studies and guidance documents, such as the agency’s 2002 

guidelines for reviewing TMDLs, for features important to TMDL 

development and implementation (see app. III for results on features). We 

used the resulting list of features to then develop a total of 82 survey 

questions, which we pretested with the three experts to ensure that 

(1) the questions were clear and unambiguous, (2) the experts interpreted 

terms and questions similarly, (3) terminology was used correctly, (4) the 

information could feasibly be obtained from TMDL documents, and (5) the 

questionnaire was comprehensive and unbiased. We changed the 

questionnaire’s content and format after the pretest according to the 

feedback we received. Independent GAO survey experts also reviewed a 

draft of the questionnaire, and we further revised the questionnaire to 

reflect that review.

To administer the questionnaire, we asked each expert to independently 

review 16 or 17 of the 25 TMDLs, fill out the questionnaire, and then 

compare and discuss responses with one another to reach consensus on 

as many questions as possible; we collected the questionnaire data from 

March through May 2013. We first randomly assigned each expert a set 

of TMDLs to review; we then assigned half of each expert’s set to another 

expert to review, such that each half of one expert’s assignment 

overlapped with half of another expert’s assignments, and, thus, each 

Experts’ Review of LongEstablished TMDLs
Appendix I: Objectives, Scope, and 

Methodology

Page 73 GAO-14-80 EPA’s TMDL Program

TMDL was ultimately reviewed by two experts. The experts reviewed their 

assigned TMDLs using a self-administered electronic version of the 

questionnaire posted on the World Wide Web. We e-mailed the experts 

unique usernames and passwords to ensure that only they could 

participate in the questionnaire. To minimize potential error, we facilitated 

a Microsoft Word-based process for the experts to compare and discuss 

questionnaire responses and to reach agreement on as many responses 

as possible. For each TMDL, we compiled the responses from the two 

experts who reviewed it and sent a copy of the compiled responses to the 

experts. We identified questions to which the experts provided 

substantially divergent responses, which we defined as responses where 

the experts disagreed about the presence or absence of a feature. We 

then asked the experts to exchange comments electronically and, if 

possible, to come to agreement on the best response. Once experts 

reached agreement, we coded their questionnaire responses to reflect 

changes, if any, and to enable us to tally the final responses to each of 

our questions. In the body of our report, we present only those 

questionnaire responses that experts reached agreement on. Two 

independent GAO analysts checked and verified that responses were 

compiled correctly and that any changes were coded correctly.

As a result of our steps to minimize survey error, experts reached 

agreement on 75 percent or more of the survey questions for 24 of the 

25 TMDLs they reviewed.2

For 73 out of 82 questions, experts reached agreement on 75 percent or 

more of the TMDLs they reviewed. The 9 questions with lower rates of 

The remaining TMDL had a lower agreement 

rate, in large part because the experts disagreed about whether this 

TMDL adequately demonstrates that sediment was the cause of 

biological impairment; their differing views on this issue affected their 

responses to many survey questions about this TMDL. Another source of 

divergent answers was the size and scope of some TMDLs. A few TMDLs 

in our sample are part of large TMDL documents encompassing 

numerous water bodies. The experts said that some of these large TMDL 

documents include little to no information about the specific water bodies 

to which the TMDLs in our sample apply, which made it difficult to ensure 

that each expert was basing his evaluations on the same portion of the 

documents.

 

2

Overall, experts agreed on 88 percent of the 1,917 questions they answered.
Appendix I: Objectives, Scope, and 

Methodology

Page 74 GAO-14-80 EPA’s TMDL Program

agreement were mostly of the same type: they asked whether the experts 

thought particular elements of a TMDL contain key features that, if the 

TMDL were fully implemented, would lead to attainment of a given 

numeric water quality target. One expert consistently expressed less 

confidence than the other experts that the models and other analytical 

methods used to develop most TMDLs would lead to attainment of 

numeric water quality targets. The experts generally agreed in their 

responses to a set of related questions: they responded that, for most 

TMDLs they reviewed, elements in the TMDLs do not contain key 

features that, if the TMDL were fully implemented, would lead to 

attainment of a designated use.

To examine the extent to which long-established TMDLs exhibit factors 

that facilitate effective implementation, we surveyed state TMDL 

coordinators responsible for implementing the 191 long-established 

TMDLs in our generalizable sample. The purpose of this survey was to 

examine topics such as the extent of TMDL implementation, the extent of 

water quality improvement; factors that were helpful in implementing each 

TMDL; and factors that would have been helpful in implementing a given 

TMDL if they had been present or, if a given TMDL had not yet been 

implemented, would be helpful if it were present. To identify factors 

pertaining to TMDL implementation and to develop the survey questions, 

we reviewed EPA reports identifying particular factors associated with 

TMDLs that have been effectively implemented—that is, have helped the 

water bodies to which they apply partially or fully attain water quality 

standards (see app. IV for survey results). 

We drew an initial simple random sample of TMDLs for state coordinators 

to examine from EPA’s Assessment, TMDL Tracking and Implementation 

System database, out of a universe of 35,705 TMDLs approved by EPA 

from January 1, 1997, to December 31, 2007. To minimize the burden on 

prospective survey respondents, we drew a stratified random sample of 

191 TMDLs—the smallest number we could have drawn for a nationally 

representative sample—to reflect their proportion in the universe of 

35,075 TMDLs. Stratifying the sample in this way allowed us to reduce 

the number of TMDLs that any one state TMDL coordinator would receive 

for review. From this initial sample of 191 TMDLs, we removed TMDLs 

that were developed for entire states or multistate regions, such as those 

developed for atmospheric pollutants such as mercury or acid rain. We 

then drew a supplemental random sample to replace the TMDLs we had 

removed, so that we still had a representative sample of 191 TMDLs 

nationwide that applied to water bodies. The results of our survey are 

Survey of State TMDL 

Coordinators 
Appendix I: Objectives, Scope, and 

Methodology

Page 75 GAO-14-80 EPA’s TMDL Program

generalizable to the population of TMDLs that were developed by 

December 31, 2007, which we defined as long-established TMDLs, and 

do not apply at statewide or regional scales.

We conducted the survey by means of self-administered electronic 

questionnaires posted on the World Wide Web, and we collected survey 

data from February through May 2013. We pretested the survey 

questions with officials from four states—Illinois, Kansas, Minnesota, and 

North Carolina—to check that (1) the questions were clear and 

unambiguous, (2) terminology was used correctly, (3) the questionnaire 

did not place an undue burden on state agency officials, (4) the 

information could feasibly be obtained, and (5) the survey was 

comprehensive and unbiased. We made changes to the content or format 

of the questionnaire after each pretest according to the feedback we 

received. Independent GAO survey experts also reviewed a draft of the 

survey, and we further revised the survey to reflect that review. We 

contacted survey respondents by e-mail, and we gave each potential 

respondent a unique password and username to ensure that only 

members of the target population could participate in the survey. We sent 

follow-up e-mail messages to those who had not responded by the 

deadline, and, beginning in May 2013, we telephoned all remaining 

nonrespondents for whom contact information was available. We received 

a total of 177 survey responses, which, after certain adjustments needed 

to analyze the data, gave an overall response rate of 93 percent.

To analyze the results of our survey, we first weighted the TMDLs from 

each state coordinator in proportion to the number of TMDLs developed 

by each state; in other words, a TMDL from Pennsylvania, for example—

which had developed roughly five times as many TMDLs as, say, 

Washington State—had more weight in our analyses than a TMDL from 

Washington.

Estimates produced from the sample of projects are subject to sampling 

error. We express our confidence in the precision of our results as a 

95 percent confidence interval. This interval would contain the actual 

population value for 95 percent of the samples we could have drawn. As 

a result, we are 95 percent confident that each of the confidence intervals 

in this report includes the true values in the study population. The 

estimates from our survey generally have a margin of error of no more 

than 12 percent at the 95 percent confidence level, unless otherwise 

noted. Additionally, to encourage honest and open responses, we 

pledged in the introduction to the survey that we would report information 

in the aggregate and not report data that would identify a particular 
Appendix I: Objectives, Scope, and 

Methodology

Page 76 GAO-14-80 EPA’s TMDL Program

respondent. This report does not contain all the results from the survey; 

the survey and a more complete tabulation of the results are provided in 

appendix IV. To eliminate data-processing errors, we independently 

verified the computer program that generated the survey results.

In addition to tabulating and analyzing the frequencies of survey 

responses, we conducted a content analysis of all of the open-ended 

narrative responses received to survey questions 7, 14, 24, 26B, 27, 36, 

39G, 42, 48, and 49. We analyzed the content of the 111 responses to 

question 14, the 115 responses to question 24, the 33 responses to 

question 26B, the 72 responses to question 27, the 93 responses to 

question 36, the 51 responses to question 39G, the 52 responses to 

question 42, the 39 responses to question 45G, the 82 responses to 

question 48, and the 90 responses to question 49. Question 7 was coded 

using the following categories: additional data needed, EPA-developed 

TMDL, natural condition TMDL, new TMDLs are better, and TMDL no 

longer applies. Question 14 was coded using the following categories: 

additional data needed, legal authority lacking, limited verification data, 

low priority, and TMDL was not needed. Question 24 was coded using the 

following categories: additional priorities weighted, data available, lack of 

project sponsorship, not applicable, priority on listing, and too many 

impaired water bodies. Question 26B was coded using the following 

categories: authority rests with another agency, cumbersome or difficulty 

authority to use, improvements too costly, prefer voluntary approach, 

vague authority, and addressed point sources and municipal separate 

storm sewer systems first. Question 27 was coded using the following 

categories: forestry regulation, manure management, septic system, and 

wetland and riparian. Question 36 was coded using the following 

categories: additional data needed, consent decree TMDL, funding 

availability, low priority, more outreach needed, and poor targeting. 

Question 39G was coded using the following categories: discharge 

monitoring reports and geographic information system data. Question 48 

was coded using the following categories: additional data needed, funding 

availability, more time needed, no change expected, no longer applies, 

low priority, and now a municipal separate storm sewer system. Question 

49 was coded using the following categories: funding availability, legal 

authority lacking, stakeholders lacking, new TMDLs are better, resources 

misspent, and TMDL was not the appropriate tool. Coding was performed 

independently by two coders; team members then met to discuss the 

coding categories and reached consensus on the final coding category 

assignment for each response. Measures of reliability between GAO 

coders were calculated before codes were reconciled and found to be 
Appendix I: Objectives, Scope, and 

Methodology

Page 77 GAO-14-80 EPA’s TMDL Program

sufficiently high for purposes of this analysis. The numbers of responses 

in each content category were then summarized and tallied.

We also interviewed officials in each of EPA’s 10 regional offices 

responsible for reviewing and approving TMDLs. We discussed with 

these officials the extent to which they require states’ TMDLs to 

demonstrate key features as conditions of approving TMDLs. Further, we 

discussed with them the extent to which they encourage state programs 

to ensure the presence of factors necessary for effective TMDL 

implementation. We obtained information on the offices’ review and 

approval of state-developed TMDLs, as well as on their oversight of state 

programs, including whether and to what extent regional offices include in 

annual grants to states conditions that encourage presence of factors 

associated with effective TMDL implementation.

We conducted this performance audit from July 2012 to December 2013 

in accordance with generally accepted government auditing standards. 

Those standards require that we plan and perform the audit to obtain 

sufficient, appropriate evidence to provide a reasonable basis for our 

findings and conclusions based on our audit objectives. We believe that 

the evidence obtained provides a reasonable basis for our findings and 

conclusions based on our audit objectives.

Regional Office Review
Appendix II: National Research Council 

Experts GAO Selected to Review TMDLs

Page 78 GAO-14-80 EPA’s TMDL Program

James R. Karr

Professor Emeritus, University of Washington, Seattle 

Vladimir Novotny

Professor Emeritus, Marquette University, Milwaukee, Wisconsin, and 

Northeastern University, Boston, Massachusetts

Chris O. Yoder

Research Director, Midwest Biodiversity Institute, Columbus, Ohio

Appendix II: National Research Council 

Experts GAO Selected to Review TMDLs
Appendix III: Experts’ Review of LongEstablished TMDLs

Page 79 GAO-14-80 EPA’s TMDL Program

To examine the extent to which long-established TMDLs contain key 

features needed to enable a water body to attain water quality standards, 

we appointed water resource experts to review a random, nongeneralizable subsample of 25 TMDLs drawn from a random, 

generalizable nationwide sample (see app. I). Table 2 gives more detail 

about these 25 TMDLs.

Table 2: Random Subsample of 25 TMDLs Reviewed by Water Resource Experts

State 

Year EPA 

approved Water body classification Pollution source Stressor

Alabama 1997 River or stream Point and nonpoint Ammonia (nitrogen)

Alabama 2002 River or stream Point and nonpoint Biochemical oxygen demand 

Arkansas 2006 River or stream Point and nonpoint Copper

California 2006 River or stream Point and nonpoint Siltation

Colorado 2002 River or stream Nonpoint Lead

Connecticut 2005 Lake, reservoir, or pond Point and nonpoint Phosphorus

Georgia 2002 River or stream Point and nonpoint Sediment

Hawaii 2007 River or stream Point and nonpoint Nutrients (nitrogen and phosphorus)

Indiana 2006 River or stream Point and nonpoint E. coli bacteria

Iowa 2004 Lake, reservoir, or pond Nonpoint Algal growth

Kansas 2004 River or stream Point and nonpoint Sulfate

Maryland 2007 River or stream Nonpoint Sulfate

Massachusetts 2002 Lake, reservoir, or pond Nonpoint Phosphorus

Mississippi 2003 River or stream Point and nonpoint Biochemical oxygen demand 

Mississippi 2007 River or stream Nonpoint Sediment

New Mexico 2006 River or stream Nonpoint Turbidity

Oregon 2006 River or stream Point and nonpoint Temperature

Oregon 2007 River or stream Point and nonpoint Temperature

Pennsylvania 2003 River or stream Nonpoint Phosphorus

South Dakota 2001 Lake, reservoir, or pond Nonpoint Eutrophication

South Dakota

a

2003 River or stream Point Ammonia (nitrogen)

Utah 2002 River or stream Nonpoint Phosphorus

Washington 2007 River or stream Point and nonpoint Temperature

Wisconsin 2005 River or stream Nonpoint Sediment

Wyoming 2007 River or stream Point Chlorine

Source: GAO analysis of EPA data.

a

Appendix III: Experts’ Review of LongEstablished TMDLs

Eutrophication is the natural process by which lakes and ponds age as minerals and organic matter 

accumulate in the water over thousands of years. These nutrients promote blooms of algae, which 

drop to the bottom when they die, in turn increasing oxygen-demanding decomposition rates and 

depleting oxygen needed by other forms of life in the lake. As a result, overall diversity of life in the 
Appendix III: Experts’ Review of LongEstablished TMDLs 

Page 80 GAO-14-80 EPA’s TMDL Program

lake declines. Excess nutrients contributed by human activities, such as the application of nitrogenrich fertilizers, hastens this process.

Table 3 shows the results of the experts’ review of the TMDLs listed in 

table 2. These results are expressed as the number of TMDLs containing 

the feature listed in each table row.

Table 3: Number of Long-Established TMDLs in Which Experts Found Key Features Needed to Enable Water Bodies to Attain 

Water Quality Standards

Experts agreed

EPA 

element TMDL key feature

Contain 

feature 

Do not 

contain 

feature 

Not enough 

information 

Feature not 

applicable

Experts did 

not agree

1 Provides sufficient evidence that water 

quality is impaired by the selected 

pollutant of concern

18 6 0 0 1 

Addresses chemical stressors that may 

be affecting attainment of water quality 

standards

14 8 0 3 0 

Addresses biological stressors that may 

be affecting attainment of water quality 

standards

8 11 0 2 4 

Addresses physical stressors that may 

be affecting attainment of water quality 

standards

8 13 0 3 1 

2 Demonstrates that achieving numeric 

water quality target for given pollutant 

will lead to attainment of designated use

7 17 1 0 0 

Describes scientific linkage between 

numeric water quality target and 

pollutant of concern

15 4 0 3 3 

Describes how numeric water quality 

target was calculated

22 3 0 0 0 

Represents numeric water quality target 

in terms of magnitude, or how much 

pollutant of concern can be present 

without loss of water’s designated use

22 1 0 1 1 

Represents numeric water quality target 

in terms of duration, or time period over 

which pollutant levels are to be 

measured to determine how much 

pollutant can be present without loss of 

designated use

18 2 0 2 3 
Appendix III: Experts’ Review of LongEstablished TMDLs

Page 81 GAO-14-80 EPA’s TMDL Program

Experts agreed

EPA 

element TMDL key feature

Contain 

feature 

Do not 

contain 

feature 

Not enough 

information 

Feature not 

applicable

Experts did 

not agree

Represents numeric water quality target 

in terms of frequency, or how often 

numeric water quality target may be 

exceeded without loss of designated 

use 14 5 0 3 3 

Numeric water quality target is 

measurable with reasonably obtainable 

monitoring data 25 0 0 0 0 

Numeric water quality target accounts 

for pollutant loads flowing into or out of 

other water bodies or segments not part 

of geographic area of water body to 

which TMDL applies 15 2 5 0 3 

3 Describes “critical conditions,” or worstcase scenario of environmental 

conditions in water body under which 

relevant pollutant loading will still allow 

water body to attain water quality 

standards 17 4 1 0 3 

Model or other method used to calculate 

loading capacity includes natural 

processes taking place in the watershed 19 2 1 0 3 

Model or other method used to calculate 

loading capacity is appropriately 

complex 14 4 0 0 7 

Explains any assumptions in the TMDL 

analysis 22 1 0 0 2 

Describes strengths and weaknesses in 

analytical process used to calculate 

loading capacity 11 13 0 0 1 

Describes results from any water quality 

modeling used in the TMDL analysis 17 1 0 2 5 

4 Demonstrates that meeting load 

allocations will have desired effect on 

water quality conditions needed to attain 

designated use 12 8 0 2 3 

Identifies the nonpoint sources 

contributing to impairment precisely 

enough for load allocations to be 

implemented 12 5 2 2 4 

5 Specifies pollutant limits in individual 

permits for point source facilitiesa 15 1 1 6 2 
Appendix III: Experts’ Review of LongEstablished TMDLs

Page 82 GAO-14-80 EPA’s TMDL Program

Experts agreed

EPA 

element TMDL key feature

Contain 

feature 

Do not 

contain 

feature 

Not enough 

information 

Feature not 

applicable

Experts did 

not agree

Demonstrates that wasteload 

allocations for individual point source 

permit holders will not cause localized 

impairments 8 5 0 6 6 

Demonstrates that pollutant loads have 

not been reallocated from nonpoint 

sources to point sources 8 2 4 6 5 

6 Refers to a margin of safety 23 1 0 0 1 

Includes an explicit uncertainty analysis 

as basis for determining margin of 

safety 2 19 0 2 2 

Margin of safety adequately

accommodates variability that might 

impair attainment of numeric water 

quality target 9 7 5 2 2 

7 Refers to seasonal variation 23 1 0 0 1 

Includes information about how 

seasonal variations in stressors 

influence water quality 17 3 0 4 1 

Describes method chosen for 

incorporating seasonal variation 18 1 1 4 1 

8 Refers to reasonable assurances 8 5 0 12 0 

Provides sufficient evidence that 

reductions in nonpoint source pollution 

will occur 0 6 0 17 2 

Identifies specific actions that need to 

occur to attain a water quality standard 8 0 0 17 0 

Identifies land areas where actions 

need to occur to attain a water quality 

standard 6 1 0 17 1 

9 Refers to a monitoring plan to track 

TMDL effectiveness 18 7 0 0 0 

Monitoring plan describes data to be 

collected to determine if TMDL’s 

targeted load reductions are occurring 8 5 0 7 5 

Monitoring plan includes indicators 

reflecting biological responses, such as 

measures of biological diversity and 

relative abundance of particular groups 

of aquatic organisms 3 14 0 7 1 

Includes information about combining 

monitoring data and modeling so as to 

assess modeling error 0 13 0 8 4 
Appendix III: Experts’ Review of LongEstablished TMDLs

Page 83 GAO-14-80 EPA’s TMDL Program

Experts agreed

EPA 

element TMDL key feature

Contain 

feature 

Do not 

contain 

feature 

Not enough 

information 

Feature not 

applicable

Experts did 

not agree

Describes an adaptive approach to 

implementing the TMDL, whereby 

monitoring and data analysis will be

used to periodically assess progress 

toward water quality standards and 

TMDL will be adjusted as needed 9 8 0 7 1 

10 Refers to implementation 21 4 0 0 0 

Identifies actors to help support TMDL 

implementation 14 7 0 4 0 

Identifies actions that can help attain 

water quality standards 12 7 0 4 2 

Includes a formal TMDL implementation 

plan 6 19 0 0 0 

Implementation plan identifies actors to 

help support TMDL implementation 5 1 0 19 0 

Implementation plan identifies specific 

actions that need to occur to attain 

water quality standards 5 1 0 19 0 

Implementation plan identifies land 

areas where actions need to occur to 

attain water quality standards 3 2 0 19 1 

Implementation plan provides sufficient 

evidence that reductions in nonpoint 

source pollution will occur 0 5 0 19 1 

11 Refers to public participation 21 4 0 0 0 

Describes extent of public participation, 

such as number or types of public 

meetings 8 10 0 4 3 

Includes a summary of significant public 

comments and state’s response 3 17 0 4 1 

Source: GAO.

Notes: Numbers in this table represent numbers of TMDLs in a random subsample of 25 TMDLs. 

Each TMDL was independently reviewed by two experts to increase the reliability of our findings. For 

each column under “Experts agreed,” the two experts agreed that the given feature in a row was 

present in that number of TMDLs. For the TMDLs tallied in the last column at right, the two experts 

who reviewed them did not reach agreement on the presence or absence of the given feature.

a

Permits are those issued to point source facilities under the National Pollutant Discharge Elimination 

system permit program.
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 84 GAO-14-80 EPA’s TMDL Program

The questions we asked of state TMDL coordinators in a nationwide 

survey of long-established TMDLs are shown below. In our survey, we 

asked both closed and open-ended questions about specific TMDLs. For 

closed questions, we have included the frequency for each response 

option that state TMDL coordinators selected and a representative 

estimate for each response when it was generalizable. Generally, we 

considered a response to be generalizable when the bounds of the 95 

percent confidence interval did not exceed 12 percent. For the openended questions in our survey, we have provided the three most 

prevalent response themes when we could identify them. For a more 

detailed discussion of our survey and sampling methodology see 

appendix I.

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Q1. Was the TMDL for [pollutant] in [water body] 

developed in response to a consent decree or other 

settlement order?

Yes 79 62.7 54-71.4

No 89 36.0 27.4-44.5

Don’t know 6 1.3 0-2.7

Q2. Generally, were land use data available when 

developing the TMDL for [pollutant] in [water 

body]?

Yes 154 92.4 88.4-96.4

No 10 4.9 1.5-8.3

Don’t know 9 2.7 0.5-4.9

Q2A. If yes, how helpful was the availability of land 

use data when developing the TMDL?

Very helpful 77 52.3 42-62.6

Somewhat helpful 51 28.9 20-37.7

Not helpful 23 18.8 9.4-28.3

Q2B. If no, how helpful would the availability of land 

use data have been when developing the TMDL?

Very helpful 2 . Data not generalizable

Somewhat helpful 5 . Data not generalizable

Not helpful 3 . Data not generalizable

Q3. Generally, were land cover data available 

when developing the TMDL for [pollutant] in [water 

body]?

Yes 150 89.7 84.9-94.5

No 12 6.4 2.5-10.4

Don’t know 11 3.9 1.2-6.6

Q3A. If yes, how helpful was the availability of land 

cover data when developing the TMDL?

Very helpful 71 49.8 39.3-60.3

Somewhat helpful 51 30.5 21.3-39.7

Not helpful 25 19.7 10-29.3

Q3B. If no, how helpful would the availability of land 

cover data have been when developing the TMDL?

Very helpful 6 . Data not generalizable

Somewhat helpful 4 . Data not generalizable

Not helpful 2 . Data not generalizable

Q4. Generally, were ambient water quality data Yes 150 89.8 84.5-95.2

Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

TMDL Development
Appendix IV: Survey of State TMDL

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 85 GAO-14-80 EPA’s TMDL Program

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

available when developing the TMDL for [pollutant] 

in [water body]?

No 11 5.8 2.2-9.3

Don’t know 11 4.4 0.2-8.6

Q4A. If yes, how helpful was the availability of 

ambient water quality data when developing the 

TMDL?

Very helpful 122 84.8 78.1-91.5

Somewhat helpful 22 14.2 7.6-20.7

Not helpful 3 1.1 0-2.5

Q4B. If no, how helpful would the availability of 

ambient water quality data have been when 

developing the TMDL?

Very helpful 3 . Data not generalizable

Somewhat helpful 6 . Data not generalizable

Not helpful 1 . Data not generalizable

Q5. Generally, were source loading data available 

when developing the TMDL for [pollutant] in [water 

body]?

Yes 94 63.3 54.5-72.1

No 63 33.5 24.9-42.2

Don’t know 15 3.2 1.2-5.2

Q5A. If yes, how helpful was the availability of 

source loading data when developing the TMDL?

Very helpful 72 79.5 70.2-88.9

Somewhat helpful 20 20.5 11.1-29.8

Q5B. If no, how helpful would the availability of 

source loading data have been when developing 

the TMDL?

Very helpful 27 . Data not generalizable

Somewhat helpful 23 . Data not generalizable

Not helpful 4 3.5 0-7.8

Q6. Were runoff quality data available when 

developing the TMDL for [pollutant] in [water 

body]?

Yes 36 21.6 13.7-29.4

No 110 68.7 60-77.4

Don’t know 25 9.7 4.8-14.6

Q6A. If yes, how helpful was the availability of 

runoff quality data in developing the TMDL?

Very helpful 29 95.6 91.6-99.6

Somewhat helpful 3 2.2 0-4.9

Not helpful 3 2.2 0-4.9

Q6B. If no, how helpful would the availability of 

runoff quality data have been when developing the 

TMDL?

Very helpful 31 23.8 14.4-33.1

Somewhat helpful 47 . Data not generalizable

Not helpful 17 . Data not generalizable

Q7. Is there anything further we should know about the development of the TMDL for [pollutant] in [water body]?

Open-ended response theme Number of responses

Older TMDLs are not as comprehensive or as accurate as newer ones. 14

The state TMDL coordinator had limited information on the TMDL because EPA developed the 

TMDL.

12

Additional data or specificity would have made the TMDL more implementable. 10

Total coded responses 54
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 86 GAO-14-80 EPA’s TMDL Program

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Q8. Was it necessary to revise National Pollutant

Discharge Elimination System (NPDES) permits to 

meet the wasteload allocation in the TMDL for 

[pollutant] in [WATERBODY]?

Yes 36 20.7 12.7-28.7

No 138 79.3 71.3-87.3

Q9. Since EPA approved the TMDL in [year], how 

many of the NPDES permits for [pollutant] 

discharge that needed revision has your state 

been able to revise?

All 24 . Data not generalizable

More than half 4 . Data not generalizable

About half 1 2.9 0-8.7

Less than half 3 4.3 0-10.6

None 4 2.9 0-6.1

Q10. How confident are you in the accuracy of 

your answer to question 9?

Extremely confident 20 . Data not generalizable

Very confident 11 . Data not generalizable

Moderately confident 2 5.1 0-14.1

Somewhat confident 3 . Data not generalizable

Q11. Was it necessary to install best management 

practices to meet the load allocation for [pollutant] 

in [WATERBODY]?

Yes 109 66.7 57.4-76.1

No 52 33.3 23.9-42.6

Q12. Since EPA approved the TMDL in [year], 

about how many of the landowners who needed to 

install best management practices for [pollutant] 

had them installed?

Not checked 1 1.1 0-3.3

All 1 1.1 0-3.3

More than half 15 19.2 8.2-30.2

About half 12 14.0 4.7-23.4

Less than half 50 . Data not generalizable

None 17 10.2 4.1-16.4

Q13. How confident are you in the accuracy of 

your answer to question 12?

Extremely confident 11 9.8 3.2-16.5

Very confident 19 18.3 8.5-28.1

Moderately confident 27 . Data not generalizable

Somewhat confident 22 22.3 11.1-33.4

Not confident 18 16.2 7.8-24.6

Status of TMDL 

Implementation 
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 87 GAO-14-80 EPA’s TMDL Program

Q14. Is there anything else we should know about the implementation status of the TMDL for [pollutant] in [water body]?

Open-ended response theme Number of responses

Limited data exist to verify implementation. 17

No legal authority to compel polluters or landowners to abate nonpoint source pollution. 14

Additional data or specificity would have made the TMDL more implementable. 9 

Total coded responses 50

Factors That Helped or Could Have Helped Implementation

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Q15. Since EPA approved the TMDL in [year], 

was your agency able to find enough 

landowners in the area covered by the TMDL 

who were willing to install best management 

practices on their properties?

Yes 31 . Data not generalizable

No 30 19.0 9.9-28.1

Don’t know 40 . Data not generalizable

Q15A. If yes, how helpful was the willingness 

of landowners to install best management 

practices in implementing the TMDL?

Very helpful 17 . Data not generalizable

Somewhat helpful

a

14 . Data not generalizable

Q15B. If no, how helpful would the willingness 

of landowners to install best management 

practices have been in implementing the 

TMDL?

Very helpful 20 . Data not generalizable

Somewhat helpful 9 . Data not generalizable

Not helpful 1 5.2 0-15.9

Q16. Since EPA approved the TMDL in [year], 

were landowners in the area covered by the 

TMDL generally willing to install the types of 

best management practices that are mosteffective at reducing [pollutant] loads?

Yes 35 . Data not generalizable

No 14 11.2 3.2-19.3

Don’t know 53 . Data not generalizable

Q16A. If yes, how helpful was the willingness 

of landowners to install the most-effective 

types of best management practices in 

implementing the TMDL?

Very helpful 24 . Data not generalizable

Somewhat helpful 10 . Data not generalizable

Q16B. If no, how helpful would the willingness 

of landowners to install the most-effective 

types of best management practices have 

been in implementing the TMDL?

Very helpful 11 . Data not generalizable

Somewhat helpful 2 . Data not generalizable

Q17. Since EPA approved the TMDL in [year], 

were landowners generally willing to install 

best management practices in the area 

covered by the TMDL where they could most 

effectively reduce [pollutant] loads?

Yes 31 . Data not generalizable

No 15 10.7 2.9-18.6

Don’t know 56 . Data not generalizable

Q17A. If yes, how helpful was the willingness 

of landowners to install best management 

practices in the places where they could most 

effectively reduce [pollutant] loads in 

implementing the TMDL?

Very helpful 24 . Data not generalizable

Somewhat helpful 7 . Data not generalizable
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 88 GAO-14-80 EPA’s TMDL Program

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Q17B. If no, how helpful would the willingness 

of landowners to install best management 

practices in places where they could most 

effectively reduce [pollutant] loads have been 

in implementing the TMDL?

Very helpful 11 . Data not generalizable

Somewhat helpful 4 . Data not generalizable

Q18. Since EPA approved the TMDL in [year], 

was enough funding available to implement 

best management practices to reduce 

[pollutant] in [WATERBODY]?

Enough funding was 

available to implement 

best management 

practices

15 14.1 5.5-22.7

Some funding was 

available to implement 

best management 

practices

40 . Data not generalizable

Not enough funding was 

available to implement 

best management 

practices

45 . Data not generalizable

Q18A. If more than enough funding was 

available or enough funding was available to 

implement best management practices, how 

helpful was available funding in implementing 

the TMDL?

Very helpful 9 . Data not generalizable

Somewhat helpful 1 . Data not generalizable

Q18B. If some funding was available or not 

enough funding was available, how helpful 

would the availability of additional funding have 

been in implementing the TMDL?

Very helpful 44 . Data not generalizable

Somewhat helpful 25 . Data not generalizable

Not helpful 4 4.1 0-9 

Q19. Since EPA approved the TMDL in [year], 

was an implementation plan developed to 

reduce [pollutant] in [water body] that 

contained reasonable assurances with specific 

implementation activities and milestones?

Yes 43 . Data not generalizable

No 48 . Data not generalizable

Don’t know 13 14.9 5.1-24.7

Q19A. If yes, how helpful was an 

implementation plan in implementing the 

TMDL?

Very helpful 23 . Data not generalizable

Somewhat helpful 15 . Data not generalizable

Not helpful 5 7.4 0-15.8

Q19B. If no, how helpful would an 

implementation plan have been in 

implementing the TMDL?

Very helpful 16 . Data not generalizable

Somewhat helpful 23 . Data not generalizable

Not helpful 7 . Data not generalizable

Q20. Since EPA approved the TMDL in [year], 

did land in the area covered by the TMDL for 

[pollutant] in [water body] become more 

developed?

Yes 32 32.8 21-44.6

No 48 . Data not generalizable

Don’t know 25 20.3 10.3-30.2

Q20A. If yes, how helpful was land 

development in implementing the TMDL?

Very helpful 4 11.8 0-23.7

Somewhat helpful 6 . Data not generalizable

Not helpful 22 . Data not generalizable
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 89 GAO-14-80 EPA’s TMDL Program

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Q20B. If no, how helpful would land 

development have been in implementing the 

TMDL?

Somewhat helpful 10 . Data not generalizable

Not helpful 35 . Data not generalizable

Q21. Since EPA approved the TMDL in [year], 

has land in the area covered by the TMDL for 

[pollutant] in [water body] been retired?

Yes 16 15.2 6.6-23.8

No 45 . Data not generalizable

Don’t know 44 38.8 26.9-50.6

Q21A. If yes, how helpful was land retirement 

in implementing the TMDL?

Very helpful 5 . Data not generalizable

Somewhat helpful 8 . Data not generalizable

Not helpful 3 . Data not generalizable

Q21B. If no, how helpful would land retirement 

have been in implementing the TMDL?

Very helpful 5 . Data not generalizable

Somewhat helpful 14 . Data not generalizable

Not helpful 23 . Data not generalizable

Q22. Does your agency administer EPA’s 

section 319 nonpoint source management 

Program in your state?

Yes 93 92.0 86.8-97.2

No 12 8.0 2.8-13.2

Q22A. If yes, how helpful was your agency’s 

administration of the section 319 program in 

implementing the TMDL for [pollutant] in [water 

body]?

Very helpful 34 32.1 20.3-43.9

Somewhat helpful 21 18.8 9.6-28.1

Not helpful 33 . Data not generalizable

Q22B. If no, how helpful would administering 

the section 319 program have been in 

implementing the TMDL for [pollutant] in [water 

body]?

Very helpful 6 . Data not generalizable

Somewhat helpful 3 . Data not generalizable

Not helpful 3 . Data not generalizable

Q23. When awarding section 319 funding, 

does your state a give a higher priority to water 

bodies with TMDLs, as compared with water 

bodies without TMDLs?

Yes 95 93.2 88.4-98

No 9 6.5 1.8-11.3

Don’t know 1 0.2 0-0.7

Q23A. If yes, how helpful has giving a higher 

priority to water bodies with TMDLs, as 

compared with water bodies without TMDLs 

been in implementing the TMDL for [pollutant] 

in [water body]?

Very helpful 34 . Data not generalizable

Somewhat helpful 21 17.7 8.2-27.1

Not helpful 39 . Data not generalizable

Q23B. If no, how helpful would giving a higher 

priority to water bodies with TMDLs, as 

compared with water bodies without TMDLs 

have been in implementing the TMDL for 

[pollutant] in [water body]?

Very helpful 3 . Data not generalizable

Somewhat helpful 5 . Data not generalizable

Not helpful 1 . Data not generalizable

a

In the report, we combined the responses to those questions in which the state TMDL coordinators 

responding to our survey indicated that the factor either was helpful (if present) or (if factor was not 

present or TMDL was not yet implemented) would have been or would be helpful in implementing the 

TMDL in question. Unless otherwise noted, those combined estimates had margins of error of no 

more than 12 percent. When presented separately in this appendix, the questions had fewer 

responses and more often had margins of error that exceeded 12 percent, and we do report them as 

not generalizable.
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 90 GAO-14-80 EPA’s TMDL Program

Q24. If not addressed by question 23, how, if at all, does your state prioritize funding for water bodies with TMDLs?

Open-ended response theme Number of responses

The state considers additional or other priorities when prioritizing funding. 22

Lack of a sponsor, such as a citizen-based group, prevents the awarding of 319 funds. 15

Funding is prioritized according to whether a water body is on the state’s 303(d) list, rather than if there’s 

a TMDL to address the listing.

10

Total coded responses 48

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Q25. Does your state have legal authority to compel 

landowners to reduce nonpoint source [pollutant] discharge 

from their properties?

Yes 43 . Data not generalizable

No 61 . Data not generalizable

Q26. If you answered yes to question 25, since EPA 

approved the TMDL in [year], has your state exercised its 

legal authority to compel landowners to reduce nonpoint 

source pollution from their properties?

Yes 10 . Data not generalizable

No 16 . Data not generalizable

Don’t know 14 . Data not generalizable

Q26A. If yes, how many times has your state exercised its legal authority to compel landowners to reduce nonpoint source pollution 

from their properties in the TMDL for [pollutant] in [water body]?

Respondents reported that they used their state legal authority 7 times in the long-established TMDLs in our sample.

26b. If no, why did your state choose not to use its legal authority to compel landowners to reduce nonpoint source pollution from their 

properties?

Open-ended response theme Number of responses

The state prefers to use a voluntary approach. 15

Using the state’s legal authority is cumbersome or difficult because it requires identification of 

specific violators. 

6 

The state’s legal authority to address nonpoint source pollution is vague. 5 

Total coded responses 29

Q27. If local government agencies in your state have legal authority to compel landowners to reduce nonpoint source pollution from 

their properties, please describe this authority and how it applied to the TMDL for [pollutant] in [water body], if at all.

Open-ended response theme Number of responses

Livestock management act, county manure management laws, or local waste storage laws 6 

Septic system enforcement, typically through county health departments 5 

Wetland protection and riparian buffers 4 
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 91 GAO-14-80 EPA’s TMDL Program

Open-ended response theme Number of responses

Total coded responses 14

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Q28. Since EPA approved the TMDL for 

[pollutant] in [water body] in [year], has the U.S. 

Department of Agriculture assisted your agency in 

implementing the TMDL?

Yes 45 . Data not generalizable

No 27 21.5 12-31

No assistance was 

necessary

21 . Data not generalizable

Don’t know 11 7.9 2.1-13.7

Q28A. If yes, how helpful was the assistance of 

the U.S. Department of Agriculture in 

implementing the TMDL?

Very helpful 23 . Data not generalizable

Somewhat helpful 20 . Data not generalizable

Not helpful 2 6.9 0-16.6

Q28B. If no, how helpful would the assistance of 

the U.S. Department of Agriculture have been in 

implementing the TMDL?

Very helpful 8 . Data not generalizable

Somewhat helpful 12 . Data not generalizable

Not helpful 6 . Data not generalizable

Q29. Since EPA approved the TMDL for 

[pollutant] in [water body] in [year], has the U.S. 

Environmental Protection Agency assisted your 

agency to implementing the TMDL?

Not checked 1 1.0 0-2.9

Yes 43 37.1 25.6-48.6

No 43 . Data not generalizable

No assistance was 

necessary

13 9.3 3.3-15.2

Don’t know 5 5.3 0-11.9

Q29A. If yes, how helpful was the assistance of 

the U.S. Environmental Protection Agency in 

implementing the TMDL?

Very helpful 28 . Data not generalizable

Somewhat helpful 13 . Data not generalizable

Not helpful 2 6.6 0-15.9

Q29B. If no, how helpful would the assistance of 

the U.S. Environmental Protection Agency have 

been in implementing the TMDL?

Very helpful 4 9.7 0-20.6

Somewhat helpful 20 . Data not generalizable

Not helpful 13 . Data not generalizable

Q30. Since EPA approved the TMDL for 

[pollutant] in [water body] in [year], has a state 

government agricultural program assisted your 

agency to implementing the TMDL?

Yes 43 . Data not generalizable

No 28 17.6 9.6-25.5

No assistance was 

necessary

24 . Data not generalizable

Don’t know 10 8.5 1.1-15.9

Q30A. If yes, how helpful was the assistance of a 

state government agricultural program in 

implementing the TMDL?

Very helpful 24 . Data not generalizable

Somewhat helpful 18 . Data not generalizable

Not helpful 1 0.6 0-1.8

Q30B. If no, how helpful would the assistance of a 

state government agricultural program have been 

in implementing the TMDL?

Very helpful 5 . Data not generalizable
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 92 GAO-14-80 EPA’s TMDL Program

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Somewhat helpful 13 . Data not generalizable

Not helpful 10 . Data not generalizable

Q31. Since EPA approved the TMDL for 

[pollutant] in [water body] in [year], has a state 

government stormwater program assisted your

agency in implementing the TMDL?

Yes 32 28.2 18.1-38.3

No 32 23.7 13.3-34.1

No assistance was 

necessary

37 . Data not generalizable

Don’t know 4 4.6 0-10.8

Q31A. If yes, how helpful was the assistance of a 

state government stormwater program in 

implementing the TMDL?

Very helpful 15 . Data not generalizable

Somewhat helpful 14 . Data not generalizable

Not helpful 3 7.7 0-17.6

Q31B. If no, how helpful would the assistance of a 

state government stormwater program have been 

in implementing the TMDL?

Very helpful 1 4.2 0-13

Somewhat helpful 8 . Data not generalizable

Not helpful 22 . Data not generalizable

Q32. Since EPA approved the TMDL for 

[pollutant] in [water body] in [year], has a state 

government nonpoint source program assisted 

your agency in implementing the TMDL?

Yes 65 69.6 58.2-81

No 28 22.8 12.1-33.5

No assistance was 

necessary

9 7.0 1.6-12.5

Don’t know 2 0.5 0-1.2

Q32A. If yes, how helpful was the assistance of a 

state government nonpoint source program in 

implementing the TMDL?

Very helpful 43 . Data not generalizable

Somewhat helpful 20 . Data not generalizable

Not helpful 1 2.3 0-6.8

Q32B. If no, how helpful would the assistance of a 

state government nonpoint source program have 

been in implementing the TMDL?

Very helpful 6 . Data not generalizable

Somewhat helpful 14 . Data not generalizable

Not helpful 6 . Data not generalizable

Q33. Since EPA approved the TMDL in [year] for 

[pollutant] in [water body], has a state or local 

government planning agency assisted your 

agency in implementing the TMDL?

Yes 34 37.0 25.1-49

No 53 . Data not generalizable

Don’t know 17 19.5 8.9-30.1

Q33A. If yes, how helpful was the assistance of a 

state or local government planning agency in 

implementing the TMDL?

Very helpful 23 . Data not generalizable

Somewhat helpful 10 . Data not generalizable

Q33B. If no, how helpful would the assistance of a 

state or local government planning agency have 

been in implementing the TMDL?

Very helpful 7 14.3 2.6-26

Somewhat helpful 26 . Data not generalizable

Not helpful 17 . Data not generalizable

Q34. Since EPA approved the TMDL for 

[pollutant] in [water body] in [year], has a citizenbased group such as a watershed organization or 

other nongovernmental organization assisted your 

agency in implementing the TMDL?

Yes 51 . Data not generalizable

No 34 28.6 17.8-39.4

No assistance was 

necessary

4 3.0 0-6.7

Don’t know 15 14.6 6.6-22.6
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 93 GAO-14-80 EPA’s TMDL Program

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Q34A. If yes, how helpful was the assistance of a 

citizen-based group in implementing the TMDL?

Very helpful 34 . Data not generalizable

Somewhat helpful 15 . Data not generalizable

Not helpful 1 0.5 0-1.5

Q34B. If no, how helpful would the assistance of a 

citizen-based group have been in implementing 

the TMDL?

Very helpful 10 . Data not generalizable

Somewhat helpful 16 . Data not generalizable

Not helpful 4 . Data not generalizable

Q35. Since EPA approved the TMDL for 

[pollutant] in [water body] in [year], have local 

governmental leaders generally been supportive 

of implementing the TMDL?

Yes 37 . Data not generalizable

No 20 18.7 8.6-28.8

Don’t know 47 . Data not generalizable

Q35A. If yes, how helpful was the support of local 

governmental leaders in implementing the TMDL?

Very helpful 23 . Data not generalizable

Somewhat helpful 11 . Data not generalizable

Not helpful 1 0.8 0-2.3

Q35B. If no, how helpful would the support of local 

governmental leaders have been in implementing 

the TMDL?

Very helpful 7 . Data not generalizable

Somewhat helpful 6 . Data not generalizable

Not helpful 5 . Data not generalizable

Q36. Is there anything else we should know about the factors that helped or could have helped in implementing the TMDL for 

[pollutant] in [water body]?

Open-ended response theme Number of responses

The availability of funding was an obstacle to implementing the TMDL. 18

The TMDL was not a priority for implementation. 10

More public outreach is needed to implement the TMDL successfully. 9

Total coded responses 44
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 94 GAO-14-80 EPA’s TMDL Program

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Q37. Since EPA approved the TMDL for 

[pollutant] in [water body] in [year], has the 

pollutant load from point sources decreased, 

stayed the same, or increased?

Decreased 18 22.3 11.6-32.9

Stayed the same 19 . Data not generalizable

Don’t know 23 24.7 14.1-35.2

There were no point 

sources.

19 . Data not generalizable

Q38. Since EPA approved the TMDL for 

[pollutant] in [water body] in [year], has the 

wasteload allocation for point sources been met?

Yes 31 . Data not generalizable

No 7 10.9 2.5-19.2

Don’t know 21 . Data not generalizable

There was no 

wasteload allocation 

for point sources in 

the TMDL.

1 0.4 0-1.3

Q39. What is the basis for your response in question 38?

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Q39A. Water quality monitoring Yes 18 . Data not generalizable

No 16 . Data not generalizable

Q39B. Visual inspection Yes 4 . Data not generalizable

No 27 . Data not generalizable

Q39C. Revised NPDES permits Yes 17 . Data not generalizable

No 19 . Data not generalizable

Q39D. Model estimates Yes 4 . Data not generalizable

No 25 . Data not generalizable

Q39E. Land use changes Yes 4 . Data not generalizable

No 26 . Data not generalizable

Q39F. Discharge changes Yes 15 . Data not generalizable

No 19 . Data not generalizable

Q39G. Other. Please specify below Yes 28 . Data not generalizable

No 7 . Data not generalizable

Pollutant Loads from Point 

Sources 
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 95 GAO-14-80 EPA’s TMDL Program

If you checked “Other” above, what was the other source?

Open-ended response theme Number of responses

Discharge monitoring reports 11

Geographic information system data 3 

Total coded responses 15

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Q40. Within the next 5 years, do you expect the 

pollutant load to decrease, stay the same, or 

increase as a result of actions that have already 

been taken for point sources in the TMDL for 

[pollutant] in [water body]?

Decrease 15 . Data not generalizable

Stay the same 23 . Data not generalizable

Increase 1 1.7 0-5.2

Don’t know 20 . Data not generalizable

Q41. Within the next 5 years, do you expect the 

wasteload allocation for [pollutant] in [water 

body] to be met?

Yes 31 . Data not generalizable

No 5 7.4 0.5-14.4

Don’t know 23 . Data not generalizable

Q42. Is there anything else that you think we should know about point source pollutant loads in the TMDL for [pollutant] in [water 

body]?

State TMDL coordinators offered no substantive responses to this question.

Question Response Count

Estimated 

percentage

95 percent 

confidence interval

Q43. Since EPA approved the TMDL for 

[pollutant] in [water body] in [year], has the 

pollutant load from nonpoint sources decreased, 

stayed the same, or increased?

Decreased 42 32.4 22.7-42.2

Stayed the same 38 25.4 16.5-34.2

Increased 1 0.6 0-1.9

Don’t know 67 34.7 25.6-43.8

There were no nonpoint 

sources.

11 6.8 2.4-11.3

Q44. Since EPA approved the TMDL for 

[pollutant] in [water body] in [year], has the load 

allocation for nonpoint sources been met?

Yes 15 9.1 3.9-14.3

No 51 36.6 26.3-47

Don’t know 71 48.2 37.7-58.7

There was no load 

allocation for nonpoint 

sources in the TMDL.

9 6.0 1.6-10.5

Pollutant Loads from 

Nonpoint Sources
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 96 GAO-14-80 EPA’s TMDL Program

Q45. What is the basis for your response in 44?

Question Response Count

Estimated 

percentage

95 percent 

confidence interval

Q45A. Water quality monitoring Yes 65 . Data not generalizable

No 35 . Data not generalizable

Q45B. Visual inspection Yes 33 . Data not generalizable

No 49 . Data not generalizable

Q45C. Implemented best management practices Yes 52 . Data not generalizable

No 39 . Data not generalizable

Q45D. Model estimates Yes 16 15.9 5.3-26.4

No 63 84.1 73.6-94.7

Q45E. Land use changes Yes 28 . Data not generalizable

No 56 . Data not generalizable

Q45F. Discharge changes Yes 12 14.5 5.8-23.2

No 68 85.5 76.8-94.2

Q45G. Other. Please specify below Yes 28 . Data not generalizable

No 51 . Data not generalizable

If you checked “Other” above, what was the other source?

State TMDL coordinators offered no substantive responses to this question.

Question Response Count

Estimated 

percentage

95 percent confidence 

interval

Q46. Within the next 5 years, do you expect that 

the pollutant load for nonpoint sources will 

decrease, stay the same, or increase as a result 

of actions that have already been taken for 

nonpoint sources in the TMDL for [pollutant] in 

[water body]?

Decrease 41 39.9 28.8-50.9

Stay the same 45 30.1 20.4-39.8

Increase 2 0.9 0-2.4

Don’t know 50 29.1 19.7-38.5

Q47. Within the next 5 years, do you expect the 

load allocation for [pollutant] in [water body] to be 

met?

Yes 18 13.0 5.7-20.4

No 43 30.1 20-40.2

Don’t know 77 56.9 46-67.7
Appendix IV: Survey of State TMDL 

Coordinators Responsible for Implementing 

Long-Established TMDLs

Page 97 GAO-14-80 EPA’s TMDL Program

Q48. Is there anything else that you think we should know about nonpoint source pollutant loads in the TMDL for [pollutant] in [water 

body]? 

Open-ended response theme Number of responses

No changes were expected in the water body. 16

It will take more time to see changes in water quality. 11

The TMDL was not a priority for implementation. 10

Total coded responses 49

Q49. Thank you for answering these questions. Please use the following space to share with us any additional thoughts you have 

about the challenges and opportunities that face your state’s TMDL program.

Open-ended response theme Number of responses

The availability of funding was an obstacle to implementing the TMDL. 42

No legal authority to compel polluters or landowners to abate nonpoint source pollution. 25

A lack of stakeholders prevents the TMDL being implemented. 21

Total coded responses 67

Additional Comments
Appendix V: Comments from the 

Environmental Protection Agency

Page 98 GAO-14-80 EPA’s TMDL Program

Appendix V: Comments from the 

Environmental Protection Agency
Appendix V: Comments from the 

Environmental Protection Agency

Page 99 GAO-14-80 EPA’s TMDL Program
Appendix V: Comments from the 

Environmental Protection Agency

Page 100 GAO-14-80 EPA’s TMDL Program
Appendix V: Comments from the 

Environmental Protection Agency

Page 101 GAO-14-80 EPA’s TMDL Program
Appendix V: Comments from the 

Environmental Protection Agency

Page 102 GAO-14-80 EPA’s TMDL Program
Appendix VI: GAO Contact and Staff 

Acknowledgments

Page 103 GAO-14-80 EPA’s TMDL Program

J. Alfredo Gómez, (202) 512-3841 or gomezj@gao.gov

In addition to the individual named above, Susan Iott (Assistant Director), 

Nathan Anderson, Elizabeth Beardsley, Mark Braza, Ellen W. Chu, 

Catherine Hurley, Justin Fisher, Paul Kazemersky, Katherine Killebrew, 

Dan C. Royer, Kelly Rubin, and Kiki Theodoropoulos made key 

contributions to this report.

Appendix VI: GAO Contact and Staff 

Acknowledgments 

GAO Contact

Staff 

Acknowledgments 

(361422)
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