Order Code 97-831 ENR
Updated February 13, 2003
CRS Report for Congress
Received through the CRS Web
Clean Water Act and Total Maximum Daily
Loads (TMDLs) of Pollutants
Claudia Copeland
Specialist in Resources and Environmental Policy
Resources, Science, and Industry Division
Summary
Section 303(d) of the Clean Water Act requires states to identify waters that are
impaired by pollution, even after application of pollution controls. For those waters,
states must establish a total maximum daily load (TMDL) of pollutants to ensure that
water quality standards can be attained. Implementation was dormant until states and
EPA were prodded by lawsuits. The TMDL program has become controversial, in part
because of requirements and costs now facing states to implement this 30-year-old
provision of the law, as well as industries, cities, farmers, and others who may be
required to use new pollution controls to meet TMDL requirements. In July 2000, EPA
issued rules to revise and strengthen the program. The rules were widely criticized, and
congressional interest has been high. The Bush Administration delayed the effective
date of the rules until May 2003, to allow for additional review. In December 2002,
EPA proposed to withdraw the 2000 rules while it considers initiating an entirely new
rule or other options; no timetable was announced. This report will be updated.
Background
The Clean Water Act (CWA) contains a number of complex elements of overall
water quality management. Foremost is the requirement in section 303 that states
establish ambient water quality standards for water bodies, consisting of the designated
use or uses of a water body (e.g., recreational, public water supply, or industrial water
supply) and the water quality criteria which are necessary to protect the use or uses.
Through permitting, states or the Environmental Protection Agency (EPA) impose
wastewater discharge limits on individual industrial and municipal facilities to ensure
that water quality standards are attained. However, Congress recognized in the Act that,
in many cases, pollution controls implemented by industry and cities would be
insufficient, due to pollutant contributions from other unregulated sources.
Under section 303(d) of the Act, states must identify lakes, rivers, and streams for
which wastewater discharge limits are not stringent enough to achieve established water
quality standards, after implementation of technology-based controls by industrial and
Congressional Research Service ˜ The Library of Congress

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municipal dischargers. For each of these waterbodies, a state is required to set a total
maximum daily load (TMDL) of pollutants at a level that ensures that applicable water
quality standards can be attained and maintained. A TMDL sets the maximum amount
of pollution a waterbody can receive without violating water quality standards, including
a margin of safety. If a state fails to do this, the Environmental Protection Agency (EPA)
is required to develop a priority list for the state and make its own TMDL determination.
A TMDL is both a planning process for attaining water quality standards and a
quantitative assessment of problems, pollution sources, and pollutant reductions needed
to restore and protect a river, stream, or lake. TMDLs may address all pollution sources,
including point sources such as municipal sewage or industrial plant discharges; nonpoint
sources, such as runoff from roads, farm fields, and forests; and naturally occurring
sources, such as runoff from undisturbed lands.
The TMDL itself does not establish new regulatory controls on sources of pollution.
However, when TMDLs are established, municipal and industrial wastewater treatment
plants may be required to install new pollution control technology. States and EPA
enforce the TMDLs through revisions to existing permits which include the pollutant
limits and a schedule for compliance. For waters impaired by nonpoint source runoff,
because there are no federal controls over these sources under the Clean Water Act, the
primary implementation measures are state-run nonpoint source management programs
coupled with state, local, and federal land management programs and authorities and
financial assistance programs. For example, farmers and ranchers may be asked to use
alternative methods in their operations to prevent fertilizers and pesticides from reaching
streams. States may require cities to manage or control runoff from streets.
Implementation
TMDLs are one element of water quality management programs conducted by states
to implement the CWA. Other activities include standard setting, monitoring, permitting,
and enforcement. Integrating them with the TMDL program is difficult because of factors
such as different program purposes and schedules. Most states have lacked the resources
to do TMDL analyses, which involve complex assessment of point and nonpoint sources
in order to ascribe and quantify environmental effects for particular discharge sources.
Baseline water quality monitoring data for the analyses (to identify impaired waters and
pollution sources) is limited. EPA has both been reluctant to intervene in the states and
has also lacked resources to do so itself. Thus, there had been little implementation of the
provision which was enacted in 1972. Only in 1992 did EPA issue regulations requiring
states every 2 years to list waters that do not attain water quality standards and establish
TMDLs to restore water quality.
Responding to the failure of both states and EPA to meet these requirements,
however, environmental groups have filed 40 lawsuits in 38 states in the last few years.
Environmentalists see implementation of section 303(d) as important both to achieving
the overall goals and objectives of the Act and pressuring EPA and states to address
nonpoint and other sources which are responsible for many water quality impairments
nationwide but have not been controlled up to this point. Of the suits tried or settled to
date, 22 have resulted in court orders requiring expeditious development of TMDLs by
states or EPA.

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The TMDL litigation falls into five general categories, according to EPA: (1)
situations in which a state has failed to perform any section 303(d) activities; (2)
situations in which a state has engaged in some but insufficient activities to implement
section 303(d); (3) challenges to EPA’s listing of impaired waters, TMDL approval
decisions, or EPA’s promulgation of TMDLs; (4) situations in which plaintiffs are using
TMDL requirements to achieve other CWA objectives, such as forcing improved water
quality monitoring programs; and (5) challenges to the substance or content of TMDLs.1
Because of the lawsuits and existing requirements of the law, in August 1997, EPA
issued a policy which for the first time called on states to develop long-term schedules for
implementing TMDLs. Under that policy, EPA directed states to establish TMDLs in
order to meet water quality standards within 8 to 13 years.2 Development of TMDLs is
being initiated at an increasing pace (states and EPA have established about 7,800 since
1996), but most remain to be completed. The most recent state 303(d) lists, submitted in
1998, identified over 20,000 waterbodies as not meeting water quality standards, and EPA
estimates that as many as 40,000 TMDLs may need to be developed for these waters.
In August 1999, EPA proposed revisions to the TMDL regulations to clarify and
strengthen the program. The key proposed changes included: a new requirement for a
more comprehensive list of impaired and threatened waterbodies; a new requirement that
states, territories and authorized Indian tribes establish and submit schedules for
establishing TMDLs; a new requirement that the listing methodologies be more specific,
subject to public review, and submitted to EPA; clarification that TMDLs include 10
specific elements; a new requirement for an implementation plan in TMDLs; and new
public participation requirements. (For additional information, see CRS Report RL30422,
EPA’s TMDL Program: Highlights of Proposed Changes and Impacts on Agriculture.)
EPA’s proposal had few strong supporters, for varying reasons. States, which would
be directly affected by the proposal, criticized the burdens that new requirements would
place on them. They are concerned that they lack the resources to meet tight deadlines
for developing and implementing TMDLs. Further, states say that TMDLs should not
necessarily be prioritized over other elements of existing water quality management
programs. Industry groups are greatly concerned about impacts of new pollution control
requirements. But, municipal and industrial point source groups urge states and EPA to
ensure that TMDL requirements do not fall disproportionately on their discharges, while
possibly failing to address nonpoint source contributions to impaired waters. Farm groups
and others with nonpoint discharges question EPA’s authority to include nonpoint source
pollution in the TMDL program. The forestry industry vigorously criticized potential
impacts of the proposal. Environmentalists, who support the need for a stronger and more
comprehensive TMDL program, objected to the lengthy time periods in the proposal
before water quality improvements are likely to occur. They criticize the lack of
aggressive implementation of a program that has existed in the law since 1972.
1 For a summary of TMDL litigation by state, see information on EPA’s Web site:
[http://www.epa.gov/owow/tmdl/lawsuit1.html].
2 This is a longer time frame than has been mandated as a result of some of the TMDL litigation.
The schedules for TMDLs in 2 lawsuits concluded by consent decrees and settlement agreements
range from 4 years to 20 years; most call for a 10-year development schedule.

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Congressional interest has been high: by the time the final rule was signed in July
2000, 13 congressional hearings had been held, and six legislative proposals to modify
the Clean Water Act or delay the rule had been introduced.3 EPA attempted to respond
to the widespread criticism and signal flexibility on some of the most contentious points.
(For additional information, see CRS Report RL30573, Changes Recently Announced by
EPA to Its TMDL Proposal, May 31, 2000.) While the revised rule was undergoing final
review, Congress adopted a provision in H.R. 4425, the FY2001 Military
Constructions/FY2000 Urgent Supplemental Appropriations Bill, stating that no funds
may be used in FY2000 or FY2001 to “make a final determination on or implement any
new rule relative to” the August 1999 proposal. Because President Clinton intended to
sign H.R. 4425 into law but opposed the TMDL provision, the Administration accelerated
its review, allowing the EPA Administrator to sign it before President Clinton signed the
appropriations bill on July 13 (P.L. 106-246). In the final rule, EPA acknowledged
Congress’ action in H.R. 4425 and delayed the effective date of the rule’s changes until
Oct. 31, 2001. The text of the final rule was published on July 13, 2000.4
The final rule built on the current TMDL regulatory program and added details,
specific requirements, and deadlines that require states to implement plans to clean up
polluted waters. It retained the basic elements of the 1999 proposal for more
comprehensive identification of impaired waters, schedules and minimum elements for
TMDLs, and new public participation requirements. For some interested parties, what was
most of interest was what was not included in the final rule. EPA dropped several
provisions that were most controversial, including some potentially affecting agriculture
and forestry. (For additional information, see CRS Report RL30611, EPA’s TMDL
Program: Highlights of the Final Revised Rule.) The Bush Administration announced
in October 2001 that it would delay the effective date of the rule until May 2003, to allow
for further review. That announcement came after a federal court granted the
Administration’s request for a similar 18-month suspension of litigation which is
challenging the regulation (nearly a dozen interest groups have sued EPA over various
parts of the TMDL rule).
In December 2002, EPA proposed to withdraw the 2000 rule while it considers
initiating an entirely new rule or other options. Officials said that additional time beyond
May is needed to decide whether and how to revise the program and that allowing the rule
to take effect would disrupt the ongoing review. No further timetable was announced.
In the interim, current program requirements under the 1992 regulations and court-
sanctioned TMDL schedules remain in place. Stakeholders now are urging EPA to adopt
different strategies. Environmentalists say that, short of retaining the 2000 rule, the best
action would be to leave the 1992 rules in place, because, though flawed, those rules are
3 During the 106th Congress, hearings were held by the full committee or subcommittees of the
House Agriculture Committee, House Transportation and Infrastructure Committee, Senate
Agriculture, Nutrition and Forestry Committee, and Senate Environment and Public Works
Committee. Legislative proposals included H.R. 3609, H.R. 3625, H.R. 4502, S. 2041, S. 2139,
and S. 2417. H.R. 4922 was introduced after EPA issued the final revised rule.
4 U.S. Environmental Protection Agency. “Revisions to the Water Quality Planning and
Management Regulation and Revisions to the National Pollutant Discharge Elimination System
Program in Support of Revisions to the Water Quality Planning and Management Regulation;
Final Rules.” 65 Federal Register No. 135, July 13, 2000, pp. 43586-43670.

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preferable to a new rule that might weaken the program. States and many industries are
urging EPA to develop a new rule with greater implementation and enforcement
flexibility than either the 2000 rule or existing regulations.
Issues for Congress
A number of issues and options for Congress are apparent.
! Do nothing at this time. EPA had hoped that its regulatory proposals
would achieve improvements to the TMDL program and not require
legislative changes to the Clean Water Act, since the outcome of the
legislative process is uncertain. EPA also hoped that modifications of the
1999 proposal which it included in the final rule would lessen criticism
and perhaps deter congressional action. If the 2000 rule is withdrawn, as
now proposed, stakeholders will carefully analyze future EPA decisions.
! Strengthen the current program. Environmentalists have long sought
to strengthen the program, and some favor amending the Act to: impose
clear deadlines on states and EPA to carry out section 303(d), as there are
no statutory deadlines in current law; make clear that EPA has a non-
discretionary duty to act if a state fails to do so and define what EPA
actions and/or penalties would follow; and ensure that states periodically
update lists of impaired waters, so that TMDL implementation evolves
as water quality conditions change.
! Provide flexibility or limit the program. The need for flexibility to
develop and implement TMDLs is a key issue for states and industry.
Many favor policies that would not commit them to specific timeframes
for establishing and implementing TMDLs, but instead call for schedules
to reflect the availability of sound science and resources. Water quality
data are so limited, particularly concerning nonpoint sources, that many
fear that TMDL decisions will be based on unsound information and will
impose unneeded or inappropriate control mandates. The General
Accounting Office reported in 2000 that inconsistent monitoring, data
collection, and listing procedures used by states to identify impaired
waters have hindered efforts to develop effective TMDL programs
(Water Quality: Key EPA and State Decisions Limited by Inconsistent
and Incomplete Data, GAO-00-54).
! Clarify the program’s impact on nonpoint sources. Nonpoint sources
(both urban and rural) cause or contribute to water quality impairments
throughout the United States. Section 303(d) currently does not specify
whether TMDLs should cover nonpoint sources, but EPA’s long-standing
interpretation is that sources of polluted runoff should be included, along
with point sources. EPA’s interpretation has been upheld in a key court
case (Pronsolino v. Marcus, 91 F.Supp.2d 1337 (N.D.Cal Mar. 30, 2000)
aff’d, Pronsolino v. Nastri, CA9, No. 00-16026, 5/31/02). To limit
TMDL implementation only to point sources would likely impose
disproportionate requirements on cities and industries, which have been
the traditional focus of the CWA’s regulatory requirements. The 2000
rule explicitly included nonpoint source-impaired waters in the program.

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Farming and forestry groups contend that other non-regulatory CWA
programs are directed at nonpoint source pollution, and they were
concerned that EPA intends to regulate their activities through permits.
They favor excluding nonpoint sources from TMDLs, so that they do not
bear the costs of implementation and pollution controls. EPA clarified
in the final rule its understanding that it lacks regulatory authority over
nonpoint sources and only can influence their activities through use of
grants and funding.
! Consider the resource question. Both EPA and states face significant
financial and technical challenges, and costs of the TMDL rule have been
one of the most controversial issues. In 2000, the Agency projected that
the incremental cost of the rule to states will be about $23 million per
year, but states believe that costs will be higher and that assistance to
states should triple to meet their increased needs. The Bush
Administration has requested only limited budget increases in FY2003
or FY2004 for EPA and state TMDL activities.
! Further study and analysis. EPA’s FY2001 appropriation bill, P.L.
106-377, required studies by the National Academy of Sciences (NAS)
and EPA on the scientific basis of the program and on the costs to states
and businesses of implementing the TMDL rules. The NAS report,
issued in June 2001, concluded that scientific knowledge exists to move
forward with the program but recommended changes to improve
implementation. EPA’s current review of the 2000 rule is at least partly
to consider how to respond to those recommendations. EPA issued a
draft report on TMDL program costs in August 2001, estimating that
average annual costs to states and EPA of developing TMDLs could be
$63-$69 million, while implementation costs for pollutant sources could
be between $900 million and $4.3 billion per year, depending on states’
actions. (For information, see CRS Report RL31091, The Clean Water
Act’s TMDL Program: Newly Presented Options and Cost Estimates.)
Finally, the recent attention to the TMDL program raises some challenging questions
about the quality of the nation’s surface waters, those subject to the Clean Water Act.
After 30 years of implementing the law, EPA and states acknowledge that a substantial
portion of the nation’s waters still are impaired or threatened by pollution. The most
recent national inventory of water quality reported that nearly 40% of surveyed water
bodies remain too polluted for fishing, swimming, and other designated uses.5 Yet those
numbers only represent rivers, streams, and lakes actually surveyed by state monitoring
programs – typically about one-third of all waters. The TMDL assessments developed
by states are yielding more precise water quality information and are identifying large
numbers of stream segments which require additional measures before water quality
standards are attained. Full implementation of the TMDL process is likely to inform
policymakers more completely about conditions nationwide. Additional congressional
oversight of these issues also is likely.
5 U.S. Environmental Protection Agency. Office of Water. THE NATIONAL WATER QUALITY
INVENTORY: 2000 REPORT.. Washington, September 2002. 1 vol. EPA-841-R-2-001. Report
is available at: [http://www.epa.gov/305b/2000report/].

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