Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

Clean Water Act and Pollutant Total

Maximum Daily Loads (TMDLs)

(name redacted)

Specialist in Resources and Environmental Policy

January 17, 2014

Congressional Research Service

7-....

www.crs.gov

R42752

CRS Report for Congress

Prepared for Members and Committees of Congress

Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

Summary

Section 303(d) of the Clean Water Act (CWA) 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. A TMDL is both a quantitative assessment of pollution sources and pollutant reductions

needed to restore and protect U.S. waters and a planning process for attaining water quality

standards. Implementation of Section 303(d) was dormant until states and the Environmental

Protection Agency (EPA) were prodded by lawsuits. The program has been controversial, in part

because of requirements and costs faced by states, as well as industries, cities, farmers, and others

who may be required to use new pollution controls to meet TMDL requirements.

Despite controversies, the TMDL program has become a core element of overall efforts to protect

and restore water quality. States and EPA develop several thousand TMDLs annually, but many

more need to be completed. The most recent information indicates that over 41,000 waterbodies

do not meet water quality standards and need a TMDL to initiate corrective measures. The 303(d)

program has evolved, and especially during the last decade, EPA and states have addressed more

complex issues, including TMDLs involving both point (direct discharges) and nonpoint sources

(diffuse discharges) such as stormwater; TMDLs for less-traditional causes of impairment such as

climate change; TMDLs for pollutants such as mercury that involve coordination among water,

air, and other environmental programs; and multi-jurisdictional TMDLs.

The largest multi-jurisdictional TMDL, for the Chesapeake Bay watershed, has drawn

considerable attention. It was developed by EPA and was necessitated because previous largely

voluntary restoration efforts by the Bay jurisdictions were insufficient to attain water quality

standards. It addresses all segments of the Bay and its tidal tributaries that are impaired from

discharges of nitrogen, phosphorus, and sediment, with a goal of having TMDL implementation

measures in place by 2025. The Chesapeake Bay TMDL has a number of novel elements,

including Watershed Implementation Plans in which the jurisdictions identify specific measures

to achieve needed pollutant reductions, and biennial reports to the public on progress in

implementation. The Bay TMDL has been controversial with a number of groups concerned

about the costs of implementation and the likely mandatory nature of many of EPA’s and states’

actions. EPA’s authority to develop the TMDL was upheld, after a legal challenge.

When a TMDL is developed, implementation is a major uncertainty. First, Section 303(d) does

not require implementation, and states’ strategies for implementation vary widely. Only a few

have laws requiring implementation plans, while many others rely on less structured policies.

Second, a number of barriers to implementation can be identified. The most prominent is

insufficient funding, but technical impediments such as insufficient scientific data also are a

challenge. At the same time, factors that may aid effective implementation include active

involvement of stakeholders and governments, and adequate resources.

The TMDL program is in a period of transition and increasingly is addressing new challenges—

more complex TMDLs, larger scale impairments, and nonpoint sources. Other than oversight

hearings on the Chesapeake Bay TMDL, Congress has not shown active interest in the TMDL

program for more than a decade. Some stakeholders, especially states, believe that several issues

present Congress with an opportunity to examine the TMDL provisions of the CWA.

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

Contents

Background ...................................................................................................................................... 1

Implementation of Section 303(d) ................................................................................................... 2

Revising the TMDL Rules ......................................................................................................... 3

Recent Developments and Challenges ...................................................................................... 5

Administrative Developments ............................................................................................. 5

Addressing Nonpoint Sources in TMDLs ........................................................................... 5

Stormwater .......................................................................................................................... 6

Mercury ............................................................................................................................... 7

Ocean Acidification ............................................................................................................. 8

Climate Change ................................................................................................................... 9

Multi-Jurisdiction TMDLs ................................................................................................ 10

Chesapeake Bay TMDL .......................................................................................................... 12

Outside Assessments of the TMDL Program .......................................................................... 16

Factors Affecting Implementation ........................................................................................... 17

Conclusion ..................................................................................................................................... 19

Contacts

Author Contact Information........................................................................................................... 20

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

Background

The Clean Water Act (CWA) contains a number of complex and interrelated 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. Standards are then used to

determine which waters must be cleaned up, how much effluent may be discharged, and what is

needed for protection. 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 to attain and maintain

water quality standards, due to pollutant contributions from other unregulated sources.

Under CWA Section 303(d), states must identify waters for which discharge limits specified in

permits are not stringent enough to achieve established water quality standards, after

implementation of technology-based controls by industrial and municipal dischargers. For each

waterbody or segment, states1 are 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 is essentially a pollution budget, a quantitative estimate of what it takes to

achieve state water quality goals, setting the maximum amount of pollution a waterbody can

receive without violating water quality standards, including a margin of safety to account for

seasonal variations and uncertainty between pollutant loads and the quality of receiving waters.

As such, TMDLs provide a scientific calculation of how much pollutant loads need to be reduced

to meet those standards.

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 and allocate needed pollutant

reductions among categories of sources that contribute to the water quality impairment, including

point sources, such as municipal sewage treatment or industrial plant discharges (wasteload

allocation or WLA); and nonpoint sources (load allocation or LA), such as runoff from roads,

farm fields, and forests, atmospheric deposition, naturally occurring sources, and background

sources of the pollutant.

The goal of the TMDL is to eliminate an impairment, not meet a pollutant limit for its own sake.

The TMDL itself does not establish new regulatory controls on sources of pollution, and it does

not set discharge limits. Nor is it self-implementing. However, when TMDLs are established,

municipal and industrial wastewater treatment plants may be required to install new or improved

pollution control technology. For waters impaired by point source discharges, TMDLs are

enforced through revisions to existing CWA 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 (there is no CWA permit requirement as there is for point

sources), the primary implementation tools are state-run nonpoint source management programs,

coupled with state, local, and federal land management programs and authorities, and financial

1

Reference throughout this report to states includes states, U.S. territories, and Tribes authorized by EPA to administer

water quality standards on tribal lands.

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assistance and incentive programs. States can but are not required to regulate nonpoint sources to

achieve goals set out in a TMDL. For example, farmers or ranchers may be asked by states to use

alternative methods in their operations to prevent fertilizers and pesticides from reaching streams,

and they may receive funds to help them install on-farm pollution management systems or

practices.

EPA has specific responsibilities under Section 303(d). First, EPA is required to review and

approve a state’s list of impaired waters and TMDLs. Second, if a state fails to identify impaired

waters and develop a TMDL where one is needed, the CWA requires EPA to develop an impaired

waters list for the state and make its own TMDL determination. EPA is not authorized to

implement a TMDL, but the agency provides technical assistance and funding, which help states

develop and implement TMDLs.

Implementation of Section 303(d)

EPA acknowledges that a vigorous TMDL program is needed because significant water quality

problems persist in the nation’s waters, nearly 40 years after enactment of the CWA. An estimated

40% of the nation’s waters assessed by states do not meet water quality standards.2 Under the

CWA, states are responsible for developing TMDLs for waters that they identify as impaired and

for implementing pollution control actions to reduce pollution to an amount that meets water

quality standards. TMDLs are one element of state water quality management programs. Other

activities include standard setting, monitoring, permitting, and enforcement, and all must be

integrated with the TMDL program. Most states have lacked the resources to do TMDL analyses,

which involve complex assessment in order to ascribe and quantify environmental effects from

particular discharge sources. Baseline water quality monitoring data for the analyses (to identify

impaired waters and pollution sources) have been limited. EPA has both been reluctant to

intervene in the states and also lacked resources to do so itself. Thus, there was little initial

implementation of the provision enacted in 1972. Only in 1992 did EPA issue regulations

requiring states, every two years, to list waters that do not attain water quality standards and

establish TMDLs to restore water quality.

Responding to the failure of states and EPA to meet these requirements, however, environmental

groups filed lawsuits in more than three dozen states to compel compliance with the law’s

requirements. Environmentalists see implementation of Section 303(d) as important both to

achieving the overall goals and objectives of the act and to pressuring EPA and states to address

nonpoint and other sources that are responsible for many water quality impairments nationwide

but have not been well controlled. Of the suits tried or settled, nearly two dozen resulted in court

orders requiring expeditious TMDL development by states or EPA.

The TMDL litigation falls into three general categories: (1) challenges intended to compel EPA to

step in to fulfill TMDL requirements where a state has failed partially or completely to do so; (2)

challenges to EPA’s listing of impaired waters, TMDL approval decisions, or EPA’s promulgation

of TMDLs; and (3) challenges to the substance or content of TMDLs.3

2

U.S. Environmental Protection Agency, National Water Quality Inventory: Report to Congress, 2004 Reporting

Cycle, EPA 841-R-08-001, January 2009, http://water.epa.gov/lawsregs/guidance/cwa/305b/2004report_index.cfm.

3

For information on TMDL litigation by state, see http://water.epa.gov/lawsregs/lawsguidance/cwa/tmdl/lawsuit.cfm.

However, this information is a partial list that is not comprehensive or current.

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Because of the lawsuits and existing requirements of the law, in 1997, EPA issued interpretive

guidance which for the first time called on states to develop long-term schedules for

implementing TMDLs. There is neither a CWA nor a regulatory deadline for states to develop

TMDLs. Under the 1997 guidance, EPA recommends that states establish TMDLs in order to

meet water quality standards within 8 to 13 years of listing the water as impaired.4 Development

of TMDLs has increased (since 1996, states and EPA have established more than 51,000), but

many more remain to be completed. The most recent state 303(d) lists, most of them submitted in

2010 and 2012, identified over 41,000 waterbodies as not meeting water quality standards and in

need of a TMDL, affecting more than 300,000 miles of rivers and shorelines and 5 million acres

of lakes and resulting from nearly 72,000 causes of impairment.5 Nationwide, more than 50% of

all impairments are caused by nutrients and sediment, metals including mercury, and pathogens

(e.g., fecal coliform, E. coli, enterococcus bacteria, and other). Pathogens are the largest single

cause of impairments.6

Development of TMDLs does not equate automatically with restoration that attains water quality

standards. Implementation is complex and highly dependent on state and local stakeholders. It

takes time, as does demonstrating results. EPA has adopted a goal of having 3,360 waters (8.2%

of all impaired waters identified in 2002) in attainment with applicable water quality standards by

2015.7

Revising the TMDL Rules

In 1999, EPA proposed revisions to the 1992 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 a TMDL

implementation plan (Section 303(d) does not mandate implementation, a widely acknowledged

gap; see “Factors Affecting Implementation,” below); and new public participation requirements.

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

were concerned that they lack the resources to meet tight deadlines for developing and

implementing TMDLs. Further, states said that TMDLs should not necessarily be prioritized over

and should be integrated with other elements of existing water quality management programs.

Industry groups were greatly concerned about impacts of new pollution control requirements that

result from TMDLs. But, municipal and industrial point source groups urged 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 questioned EPA’s authority to include nonpoint source pollution in the

4

This is a longer time frame than has been mandated as a result of some of the TMDL litigation. The schedules for

TMDLs in lawsuits concluded by consent decrees and settlement agreements range from 4 years to 20 years; most call

for a 10-year development schedule.

5

Many waters are impaired by more than one pollutant or other cause.

6

For information, see http://iaspub.epa.gov/waters10/attains_nation_cy.control?p_report_type=T#causes_303d.

7

U.S. Environmental Protection Agency, Office of Water, National Water Program Guidance, Fiscal Year 2013,

April 2012, p. 32. In 2002, states identified 39,503 specific waterbodies as impaired.

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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 have criticized the lack of aggressive implementation of a program that has existed

in the law since 1972.

Congressional interest was high: by the time the final rule was signed in July 2000, 13

congressional hearings had been held, and a number of legislative proposals to modify the Clean

Water Act or delay the rule had been introduced.8 EPA attempted to respond to the criticism with

flexibility on some of the most contentious points. While the revised rule was undergoing final

review, Congress adopted a provision in the FY2001 Military Constructions/FY2000 Urgent

Supplemental Appropriations Bill (P.L. 106-246), stating that no funds could be used in FY2000

or FY2001 to “make a final determination on or implement any new rule relative to” the 1999

proposal. Because President Clinton intended to sign the bill into law but opposed the TMDL

limitation, the Administration accelerated its review, allowing the EPA Administrator to sign it

before President Clinton signed the appropriations bill. In the final rule, EPA acknowledged

Congress’s action in the legislation and delayed the effective date of the rule’s changes until

October 31, 2001. The text of the final rule was published on July 13, 2000.9

The final rule built on the existing regulatory program and added details, specific requirements,

and deadlines requiring states to implement plans to clean up polluted waters. It retained key

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. In

efforts to respond to criticism, EPA dropped several provisions that were most controversial,

including some potentially affecting agriculture and forestry.10

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, but in March 2003, EPA withdrew the 2000 rule

in order to consider initiating an entirely new rule or other options. Officials said that additional

time was needed to decide whether and how to revise the program and that allowing the rule to

take effect in May 2003 would disrupt the ongoing review. No further timetable was announced.

One EPA view, widely reported at the time, was that a new rule is not essential, because states are

improving and will continue to improve the pace at which TMDLs are established, even under

existing rules. Many environmentalists have said that, short of retaining the 2000 rule, the best

action would be to leave the 1992 rules in place, because, although flawed, those rules are

preferable to a new rule that might weaken the program. Other stakeholders have urged EPA to

adopt different strategies. Many states and industries favor a rule with more flexibility than either

the 2000 rule or existing regulations. In mid-2002, EPA developed a draft revised rule which it

8

During the 106th Congress, hearings were held by the House Agriculture Committee; House Transportation and

Infrastructure Committee; Senate Agriculture, Nutrition and Forestry Committee; and Senate Environment and Public

Works Committee.

9

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. 4358643670.

10

See CRS Report RL30611, EPA's Total Maximum Daily Load (TMDL) Program: Highlights of the Final Revised

Rule, by (name redacted).

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informally circulated among interest groups and federal agencies for many months, but it did not

propose a new rule. In early 2009, there were some reports of discussion among EPA officials of

reviving review of the 2000 rule, but the Obama Administration has not come forward with

proposed regulatory changes.

As a result, program requirements under the 1992 regulations and court-sanctioned TMDL

schedules remain in place and are the drivers for much of the current TMDL activity.

Recent Developments and Challenges

The earliest TMDLs developed by EPA and states often addressed impairments resulting from

single pollutants and a limited number of sources. Developing even these relatively

straightforward TMDLs presented substantial technical and scientific challenges, but the national

program has by now become a core element of overall efforts to protect and restore water quality.

States and EPA develop several thousand TMDLs annually (e.g., EPA approved 2,885 in 2012

and 2,359 in 2013). At the same time, the 303(d) program has evolved, and especially during the

last decade, EPA and states have addressed more complex issues, including TMDLs for lesstraditional causes of impairment, TMDLs involving both point and nonpoint sources, and multijurisdictional TMDLs. Legal challenges continue to influence implementation of the program.

Administrative Developments

Several provisions of the CWA direct states to report periodically to EPA on water quality

conditions and trends. The 303(d) requirement to identify impaired waters is one of these

provisions. Others are found in CWA Section 305(b), which calls for a biennial assessment of all

navigable waters in the state, and Section 314, which requires a biennial report on water quality

conditions of lakes. Since 2001, EPA has taken steps to minimize the administrative burden on the

states of implementing these overlapping provisions by integrating the requirements into a single

submission that enables a broad-scale, national inventory of water quality conditions. These

Integrated Report (IR) requirements are detailed in guidance memoranda; the most recent was

issued in March 2011.11 The IR format uses a five-part categorization approach for classifying the

status for each water segment, ranging from Category 1 (all designated uses are supported, and no

use is threatened) to Category 5 (at least one designated use is not supported or is threatened, and

a TMDL is needed—these are the waters that comprise 303(d) lists).

EPA has issued a number of guidance and other documents to support states as they address

emerging TMDL issues and concerns, which are discussed next.

Addressing Nonpoint Sources in TMDLs

The traditional focus of the CWA has been on controlling direct pollutant discharges to surface

waters from municipal and industrial point sources, through regulations and permits. Over time,

as these sources have abated pollution, uncontrolled nonpoint sources have become a larger

relative portion of remaining water quality problems. Nonpoint source pollution results from

indirect discharges to surface waters from diffuse sources such as land runoff, precipitation,

11

See “Information Concerning 2012 Clean Water Act Sections 303(d), 305(b), and 314 Integrated Reporting and

Listing Decisions,” http://water.epa.gov/lawsregs/lawsguidance/cwa/tmdl/ir_memo_2012.cfm.

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atmospheric deposition, drainage, seepage, or hydrologic modification. Nonpoint sources (both

urban and rural) are known to cause or contribute to water quality impairments throughout the

United States.

Whether and how to address nonpoint sources has been a key issue in the TMDL program. As

previously described, when states or EPA develop a TMDL, they have flexibility in making use of

available water quality management tools to allocate pollutant reductions. They can, for example,

tighten discharge limits on point sources through enforceable permits. But municipalities and

industries contend that limiting TMDLs only to point sources imposes disproportionate

requirements on their operations, especially in waters that are impaired both by point and

nonpoint sources.

Farming and forestry groups have long been concerned about how their activities might be

addressed in TMDLs and whether they might be subject to CWA regulation of some sort, even

though the act does not provide EPA with regulatory authority over nonpoint sources. EPA only

can influence activities of nonpoint sources through use of grants and funding, such as CWA

Section 319, which addresses nonpoint source pollution through state-run nonpoint pollution

management programs.12 CWA Section 303(d) does not specify whether TMDLs should cover

nonpoint sources, but EPA’s long-standing interpretation has been that nonpoint sources of

polluted runoff should be addressed, along with point sources, where they contribute to water

quality impairment. That interpretation was upheld in a key court case in 2002.13

Because their pollutant contributions are intermittent and because the principal policy tools

available to government are voluntary or incentive-based programs, not regulatory programs,

addressing nonpoint pollution sources in TMDLs is more challenging than is addressing point

sources. A TMDL must include a “reasonable assurance” component that needed load reductions

can be attained, but making this demonstration can be problematic when nonpoint sources are a

significant source of impairment, since there is no permit or similar enforcement mechanism to

provide accountability. Tracking implementation of practices to manage nonpoint pollution and

verifying results are difficult, especially practices that are done voluntarily and without federal or

state cost-share assistance. Some state officials contend that TDMLs for restoring impaired waters

are ineffective when nonpoint sources with few or no controls are the main sources of

impairment.14 One observer, however, has suggested that states avoid allocating reductions to

point sources “by relying on rather fanciful reductions from nonpoint dischargers (which, because

they have no permits, can be as fanciful as one wishes).”15

Stormwater

Throughout the United States, stormwater discharges are responsible for thousands of water

quality impairments. Stormwater is generated when precipitation from rain and snowmelt events

flows over land or impervious surfaces (paved streets, parking lots, and building rooftops) and

12

While the 319 program is voluntary at the federal level, states may include regulatory components in their 319

programs.

13

Pronsolino v. Marcus, 91 F.Supp.2d 1337 (N.D.Cal 2000) aff’d, Pronsolino v. Nastri, 291 F.3d 1123 (CA9 2002).

14

Amena H. Saiyid, “TMDLs Ineffective for Waters Impaired by Nonpoint Sources, State Officials Tell GAO,” Daily

Environment Report, vol. 141 (July 24, 2012), p. A-8.

15

Oliver A. Houck, “The Clean Water Act Returns (Again): Part 1, TMDLs and the Chesapeake Bay,” Environmental

Law Reporter, vol. 41, no. 3 (2011), pp. 10208-10228, 10211.

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does not percolate into the ground. It may be conveyed through pipes or ditches, or it may flow

over land and discharge directly into a waterbody. As the runoff flows over the land or impervious

surfaces, it accumulates debris, chemicals, sediment, or other pollutants that could harm water

quality if the runoff is discharged without treatment. The most common pollutants coming from

stormwater are nutrients, pathogens, sediment, and metals, according to EPA.

Most stormwater sources are point sources, which are regulated under the federal stormwater

regulatory program and thus are subject to CWA permit requirements. This program applies to

stormwater discharges from several broad categories: municipal separate storm sewer systems

(MS4s) that serve populations greater than 100,000 and smaller MS4s in Census-defined

urbanized areas; construction activity one acre and larger; and specified categories of industrial

activity.16

Other stormwater sources are nonpoint sources and thus are nonregulated by the CWA. Sources

include runoff from residential and commercial application of fertilizer and manure, land

disturbance and erosion, and atmospheric deposition.

Many impairments result from point source and nonpoint source stormwater discharges, and

TMDLs can address both. In developing these TMDLs, data needed to characterize loads from

regulated stormwater activities are generally available from CWA permitting programs. Assigning

wasteload allocations to these sources is done by adjusting their permit requirements. Data to

characterize loads from unregulated stormwater sources can be more difficult to obtain, and

assigning cleanup obligations to them presents the types of allocation and implementation

challenges previously discussed concerning nonpoint sources generally. The TMDL also must

recognize that stormwater may not be the only source of pollutants such as nutrients or metals in

an impaired waterbody.17

Mercury

Mercury is the cause of more than 4,700 impairments in thousands of 303(d) listed waterbodies;

more than 60% of these impairments are indicated by high mercury levels in fish. Mercury

accumulates in fish tissue as methylmercury, the form that presents the greatest risk to human

health through consumption of contaminated fish.

In many waterbodies, mercury originates largely from air sources, such as coal-fired power

plants, municipal waste combustors, and medical waste incinerators that deposit mercury in

waters or on adjacent lands that then wash into nearby waters. Contributions may come from a

combination of local, regional, and international sources. In some cases, the presence of mercury

results from past practices, such as legacy gold mining, or from geologic deposits. Some mercury

may be discharged to water from existing industrial point sources, although in many waterbodies,

the amounts are very small compared to other sources, according to EPA.

16

For information, see CRS Report 97-290, Stormwater Permits: Status of EPA’s Regulatory Program, by (name re

dacted).

17

Pathogens, metals, nutrients, and sediments are the cause of nearly 57% of impairments in 303(d) listed waters. See

http://ofmpub.epa.gov/tmdl_waters10/attains_nation_cy.control?p_report_type=T#status_of_data. How many of those

impairments are from stormwater sources is unknown.

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Since 1996, states and EPA have developed nearly 7,000 mercury TMDLs. Given the variety of

potential mercury sources, developing and implementing TMDLs for mercury-impaired waters

often involves coordination among multiple programs—water, air, waste, and toxics programs—

and multiple stakeholders. Technical and organizational challenges can be significant, particularly

where mercury is predominantly from atmospheric sources. Water management programs

generally do not control sources of air emissions, and controlling deposition that originates

outside a single jurisdiction is difficult.

Two TMDLs that notably have addressed these types of challenges are a statewide mercury

TMDL developed in Minnesota, consisting of two regional TMDLs in the state that cover 998

waterbody/pollutant combinations, and a regional mercury TMDL developed by seven northeast

states (Connecticut, Maine, Massachusetts, New York, New Hampshire, Vermont, and Rhode

Island).18 These and many other mercury TMDLs expect to be accomplished over time through

existing and future regulatory controls outside of the CWA (such as Clean Air Act regulation of

mercury emissions from coal-fired powerplants and other sources), making it difficult to estimate

with confidence the effectiveness of mercury reduction strategies. Thus, most anticipate periodic

reevaluation by the seven participating states to determine progress and the need for additional or

revised reductions to meet water quality standards.

Ocean Acidification

Oceans naturally absorb carbon dioxide (CO2) from the atmosphere, but too much CO2 can cause

them to become overly acidic. Scientists believe that ocean acidification (OA) is primarily caused

by increasing CO2 concentrations in the atmosphere. In a 2010 report, the National Research

Council of the National Academies of Sciences concluded that ocean chemistry is changing at an

unprecedented rate and magnitude due to anthropogenic CO2 emissions and that “there is a risk of

ecosystem changes that threaten coral reefs, fisheries, protected species, and other natural

resources of value to society.”19

Activists have been pressing EPA on a variety of fronts to address the role of increasing emissions

of CO2, a greenhouse gas, on climate change, including under the TMDL program. In 2009, the

Center for Biological Diversity (CBD) sued EPA in a challenge to the agency’s approval of

Washington’s 303(d) list, because the state’s list failed to include coastal waters as impaired for

marine pH due to CO2.20 CBD also sought to force EPA to revise and strengthen its existing water

quality criterion for pH in marine waters, issued in 1976. Under the CWA, EPA issues water

quality criteria, which are scientific information regarding concentrations of specific chemicals in

water which protect aquatic life or human health. States, in turn, use these EPA-recommended

criteria as a basis for developing water quality standards. CBD argued to EPA that the existing

marine pH criterion is not protective enough to address decreasing pH levels due to increased

CO2 emissions. The group contended that if states adopted more stringent marine pH criteria in

their water quality standards, more waters likely would be identified as impaired, thus requiring

18

U.S. Environmental Protection Agency, “Examples of Approved Mercury TMDLs,” http://water.epa.gov/lawsregs/

lawsguidance/cwa/tmdl/mercury.cfm.

19

National Research Council, National Academies of Science, Ocean Acidification: A National Strategy to Meet the

Challenges of a Changing Ocean, National Academies Press, 2010, p. 15. For additional information, see CRS Report

R40143, Ocean Acidification, by (name redacted) and (name redacted).

20

In chemistry, pH (potential (of) hydrogen) is a measure of the concentration of hydrogen ions in a solution, hence, its

acidity or alkalinity.

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TMDLs to achieve reduction in CO2 emissions that are responsible for the standards violations.

EPA has said that it has insufficient data to revise the national marine pH criterion at this time.

To settle the CBD lawsuit, EPA agreed to look for opportunities to use the CWA to address OA (it

did not commit to revising the existing marine pH water quality criterion). In 2010, EPA

published a Federal Register Notice seeking public comment on what considerations it should

take into account when deciding how to address the listing of waters as threatened or impaired by

OA under the TMDL program, including how to develop TMDLs for such listed waters.21 Also as

part of the settlement, EPA subsequently issued a memorandum that advised coastal states to list

waters that do not meet standards for marine pH when data are available, but the memo did not

elevate in priority the assessment and listing of waters for OA. The memo said, “EPA recognizes

that information is absent or limited for OA parameters and impacts at this point in time and,

therefore, listing for OA may be absent or limited in many States.”22 The agency expects to

provide additional guidance to states when future OA research provides improved monitoring and

assessment methods.

CBD has continued to pressure EPA. In 2013, the organization sued EPA for approving lists of

impaired waters in Oregon and Washington that exclude segments of ocean waters polluted by

acidification. Adding ocean waters to the states’ impaired lists would require the states or EPA to

develop TMDLs to protect the waters from ocean acidification.23

Climate Change

Even for relatively straightforward impairments (e.g., a single pollutant such as a heavy metal

discharged from known sources), TMDL development is complex and resource-intensive. The

process requires extensive data on current water quality conditions, pollutants and sources

causing impairments, and modeling to analyze effects of load and wasteload allocations that will

attain water quality standards with a margin of safety. Climate change considerations add even

greater complexity to the analyses, including the need to assess future conditions that are

themselves uncertain and sources that can be both domestic and global. Nevertheless, a 2011 EPA

draft report notes that climate change may alter attainability of some designated uses and

parameters related to water quality standards (e.g., lower streamflow may increase stream

temperature) and recommends that “TMDLs and water quality standards should be examined to

ensure that these remain protective of aquatic life uses under changing climatic conditions.”24

The number of future TMDLs that could or should include potential climate change effects is

unknown. According to EPA, “It is probable that most existing TMDLs do not take climate

change considerations into account, and due to the number of TMDLs in existence (~40,000) it is

not feasible to re-open each TMDL with the sole purpose of incorporating climate change

21

U.S. Environmental Protection Agency, “Clean Water Act Section 303(d): Notice of Call for Public Comment on

303(d) Program and Ocean Acidification,” 75 Federal Register 13537-13540, March 22, 2010.

22

Denise Keehner, Director, EPA Office of Wetlands, Oceans and Watersheds, memorandum, “Integrated Reporting

and Listing Decisions Related to Ocean Acidification,” November 15, 2010, p. 4.

23

Center for Biological Diversity v. EPA, W.D. Wash., No. 2:13-cv-01866, filed Oct. 16, 2013.

24

U.S. Environmental Protection Agency, Global Change Research Program, National Center for Environmental

Assessment, Implications of Climate Change for Bioassessment Programs and Approaches to Account for Effects,

Preliminary Draft, EPA/600/R-11/036A, March 2011, p. 7-1, http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=

233810. EPA expected to issue a final report in mid-2011 but has not done so.

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

considerations.” In the future, however, EPA will encourage development of TMDLs that

incorporate projected climate impacts and uncertainty, as appropriate.25

Consideration of climate change currently is occurring in a few TMDLs, including Vermont’s

phosphorus TMDL for Lake Champlain. A TMDL is required for Lake Champlain because

phosphorus concentrations in many segments of the lake are higher than levels allowed in

Vermont water quality standards. The states of Vermont and New York jointly developed a

phosphorus TMDL, which EPA approved in 2002. However, EPA’s approval of the TMDL was

challenged in a federal lawsuit, which asserted a variety of flaws, including insufficiently

stringent wasteload allocations of pollutants for point sources coupled with a lack of reasonable

assurances that nonpoint source reductions would occur; an inadequate margin of safety;

inadequate specificity of the stormwater component of the wasteload allocations; and failure to

consider water resource effects associated with documented and predicted climate change.26

In April 2010, EPA signed a settlement agreement with the environmental plaintiffs, and in

January 2011, the agency reconsidered its previous approval of the Lake Champlain TMDL and

disapproved the Vermont portion. After re-reviewing the 2002 TMDL, EPA concluded that two of

the four contested elements are not consistent with EPA regulations and guidance available at the

time of TMDL approval: margin of safety, and reasonable assurance. EPA found the two other

elements of the complaint—the stormwater component, and climate change considerations—to be

consistent with then-current rules and guidance.

Under Section 303(d)(2) of the CWA, upon disapproval of a TMDL, EPA must establish a new

TMDL to implement applicable water quality standards, and EPA has begun a new phosphorus

TMDL for the impaired Vermont segments in Lake Champlain. EPA informed the state of

Vermont that, in doing so, it may refine several aspects of the TMDL, not just the components

that were determined to be inadequate. Although EPA did not reject the challenged climate

change considerations in the 2002 TMDL, they are being addressed now: one component of

preparing the TMDL is a study of potential effects of climate change and phosphorus loads to

Lake Champlain.27 EPA is collaborating with Vermont state agencies and expects to release the

draft TMDL for public comment in spring 2014.28

Multi-Jurisdiction TMDLs

For some time, EPA has encouraged states to develop TMDLs using a watershed approach,

recognizing that, where multiple impaired segments are clustered within a watershed, it

frequently is more efficient to organize restoration activities across the watershed, instead of

doing TMDLs for individual stream segments. One of the first states where this approach was

used is Montana, but it is also reflected in other locations. In cases where the watershed spans

more than one state, TMDLs have been developed jointly or in coordination by several states.

Beyond the expected challenges of TMDL development in a single stream segment (e.g., data,

25

U.S. Environmental Protection Agency, National Water Program 2012 Strategy: Response to Climate Change,

Public Comment Draft, March 2012, p. 51, http://water.epa.gov/scitech/climatechange/upload/

NWP_Draft_Strategy_03-27-2012.pdf.

26

Conservation Law Foundation v. U.S. Environmental Protection Agency, No. 2:08-cv-00238wks (D. Vt. 2008).

27

Tetra Tech, Inc., Lake Champlain Basin SWAT Climate Response Modeling, report prepared for EPA Region I, May

2013, http://www.epa.gov/region1/eco/tmdl/lakechamplain.html.

28

http://www.epa.gov/region1/eco/tmdl/lakechamplain.html.

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

resources, scientific uncertainties), these multi-jurisdiction TMDLs present additional challenges

(e.g., differing priorities, institutional coordination).

•

Several states have developed statewide TMDLs for a single pollutant, such as

Minnesota’s mercury TMDL (described above). Other states (e.g., Florida and

North Carolina) are developing statewide TMDLs for mercury-impaired waters.

Several states also have developed statewide bacteria TMDLs (Rhode Island,

Connecticut, New Hampshire, and Vermont). New Hampshire has developed a

statewide chloride TMDL.

•

Because air deposition from outside a single region is a prominent source of

mercury impairments, many mercury TMDLs are being developed on a multijurisdiction basis, including the six-state Northeast Regional Mercury TMDL

discussed above.

•

New York and Connecticut developed TMDLs with measures needed to attain

water quality standards for dissolved oxygen in Long Island Sound. The TMDLs

require wastewater treatment plants and other point sources in both states to

reduce nitrogen discharges that contribute to the Sound’s water quality

impairment.

•

Water quality monitoring data show that approximately half of the length of the

Ohio River (475 miles) is now listed as impaired for contact recreational use. As

a result, a bacteria TMDL is now under development for the entire river due to

the diverse sources that contribute to impairments, including municipal sewer

overflows, animal feedlots, and textile and pulp mills, as well as nonpoint

sources such as leaking septic systems and land application of manure. Two EPA

regions, the six states along the river, and the Ohio River Valley Water Sanitation

Commission (ORSANCO) are participating in the TMDL.

•

In 2010, EPA approved a TMDL developed by the Washington Department of

Ecology to address nutrient enrichment problems which have caused algae

blooms and low dissolved oxygen levels in Lake Spokane. The TMDL applies to

a 63-mile stretch of the Spokane River from the Idaho-Washington border to the

lake. It is one of the first TMDLs to coordinate point source reductions across

state boundaries; it includes cross-boundary wastewater and stormwater sources

in Idaho, because the Spokane River originates in that state, and modeling

determined that those point sources contribute to water quality impairments in

the watershed in Washington. Among the challenges for Washington and EPA

was developing a TMDL with equitable allocations for dischargers in Washington

and Idaho, one that would not call for disproportionate pollutant reductions in

either state.29

The largest multi-jurisdictional TMDL, for the Chesapeake Bay watershed, is discussed next.

29

Michael A. Bussell, Director, Office of Water & Watersheds, U.S. EPA Region 10, letter to Kelly Susewind,

Washington Department of Ecology, “Approval of the Spokane River Dissolved Oxygen TMDLs.” May 10, 2010, p.

19, http://www.epa.gov/region10/pdf/tmdl/spokane_tmdl_approval_may2010.pdf.

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

Chesapeake Bay TMDL

One TMDL that touches on several of the issues discussed above and that has drawn considerable

attention and controversy, including from Members of Congress, was developed by EPA for the

64,000-square-mile Chesapeake Bay watershed.

Despite several decades of activity by governments, the private sector, and the general public,

efforts to improve and protect the Chesapeake Bay watershed have been insufficient to meet

restoration goals. Although some specific indicators of Bay health have improved slightly or

remained steady recently (such as blue crabs and underwater bay grasses), others remain at low

levels of improvement, especially water quality. Overall, the Bay and its tributaries remain in

poor health, with polluted water, reduced populations of fish and shellfish, and degraded habitat

and resources. The primary pollutants causing impairments are nutrients (nitrogen and

phosphorus) and sediment discharged from multiple urban, suburban, and rural sources around

the Bay.

In May 2009, President Obama issued an executive order that declared the Bay a “national

treasure” and charged the federal government with assuming a strong leadership role in restoring

the Bay.30 The executive order established a Federal Leadership Committee for the Chesapeake

Bay to develop and implement a new strategy for protecting and restoring the Chesapeake region.

The resulting strategy, which was released in May 2010, launched major specific environmental

initiatives to establish new clean water regulations on stormwater discharges and pollution

discharges from animal feedlots in the Bay watershed, put new agricultural conservation practices

on farms in the region, and restore land and water habitat.31

A central feature of the overall strategy is EPA’s establishment of a TMDL for Chesapeake Bay,

which was necessitated because the Bay states’ previous restoration efforts were insufficient to

attain water quality standards. Under a consent decree resolving litigation over impairment of Bay

waters, EPA was required to establish a Chesapeake Bay TMDL no later than May 1, 2011.32 EPA

issued the TMDL on December 29, 2010.

The Chesapeake Bay TMDL—which is actually divided into three separate TMDLs—is the

largest single TMDL developed to date. It addresses all segments of the Bay and its tidal

tributaries that are impaired from discharges of nitrogen, phosphorus, and sediment, with a goal

of having TMDL implementation measures in place by 2025. Nitrogen and phosphorus are

considered the main contributors to poor Bay water quality because, in excess amounts, they spur

algae blooms, which block sunlight critical to underwater grasses that support crabs, fish, and

waterfowl. When the algae die, they sink to the bottom and decompose in a process that depletes

the water of oxygen, creating so-called dead zones. Sediment also depletes water of oxygen. To

meet the TMDL goals, the amount of nitrogen entering the Bay needs to be reduced by 75.39

million pounds a year, phosphorus needs to be cut by 14.55 million pounds, and sediment needs

to be reduced by 3.7 million tons from 2009 levels. The TMDL allocates needed reductions of

these pollutants to all jurisdictions in the watershed. Detailed plans identifying specific reductions

30

Executive Order 13508, “Chesapeake Bay Protection and Restoration,” 74 Federal Register 23099-23104, May 15,

2009.

31

For information, see http://www.chesapeakebay.net/news_federalstrategy.aspx?menuitem=51207.

32

Fowler v. U.S. EPA, Case No. 1:09-CV-00005-CKK (D.D.C.), May 10, 2010.

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

are to be developed by the seven jurisdictions located in the Chesapeake Bay watershed in

Watershed Implementation Plans (WIPs).33

As part of the TMDL process, states are to prepare WIPs in three phases identifying specific

reductions and control measures to achieve needed pollutant reductions from point sources (i.e.,

industrial and municipal facilities and large animal feeding operations) and nonpoint sources (i.e.,

farms and forests). The WIPs are part of the accountability framework for the Bay TMDL. Phase

I WIPs were developed in December 2010. They generally outlined the types of controls and best

management practices (BMPs) that will be utilized to meet the first major goals of the TMDL:

that 60% of needed practices to achieve water quality standards will be in place by 2017. Each of

the states’ plans is different and reflects the states’ choices regarding localized identification of

needed controls and BMPs. Phase II WIPs describe how the jurisdictions will work with specific

localities over the next five years to reduce sources of impairment. The Bay jurisdictions are to

submit Phase III WIPs by 2017, including any modifications needed to meet the 2025 goal of

having in place 100% of practices needed to achieve the nutrient reduction targets.

The use of WIPs as part of the restoration strategy provides states flexibility to determine the mix

of specific controls they deem appropriate to meet the overall reduction goals. EPA fully expects

that the jurisdictions will meet commitments in the WIPs, but the agency also identified a number

of potential “backstop” actions available to it under the CWA if a state fails to do so, including

expanding permit coverage to currently unregulated sources, requiring net improvement offsets,

conditioning EPA grants, or increasing federal enforcement in the watershed. These CWA

backstop authorities are always available to EPA, but EPA’s use of them in the Chesapeake Bay

TMDL has been very controversial. It also marks a change from the historic nature of Bay

restoration, which was based primarily on stakeholder agreements.34 EPA’s review of the WIPs

has led to discussions with each jurisdiction to resolve certain issues, such as providing

reasonable assurance that allocation targets will be achieved. EPA’s approval of the Phase I WIPs

included certain backstops for New York, Pennsylvania, and West Virginia.35

The Chesapeake Bay TMDL has a number of novel elements. For example, building on a 2009

voluntary agreement by the Bay states, the TMDL requires the jurisdictions to commit to and

report on short-term milestones every two years to help government and the public assess

progress in implementing cleanup plans. Federal and state officials evaluated progress under the

first two-year milestone goals, which were to be reached by the end of 2011, and concluded that

in general, states have made significant overall progress and accelerated nutrient reduction

efforts, but that improvements are still needed in many areas. The mixed findings were not

unexpected. A review by environmental groups for a subset of important pollution controls found

that each state was ahead of schedule in implementing some actions, such as nutrient reduction

from wastewater treatment plants, but behind in others, such as implementing agriculture

33

New York, Pennsylvania, Maryland, Delaware, Virginia, West Virginia, and the District of Columbia.

U.S. Government Accountability Office, Chesapeake Bay Restoration Effort Needs Common Federal and State

Goals and Assessment Approach, GAO-11-802, August 2011, p. 10.

35

In New York, EPA required installation of biological nutrient removal at all wastewater treatment plants in the Bay

watershed. In Pennsylvania, EPA moved 50% of the state’s stormwater allocation into wasteload allocation, meaning

that the state likely will have to regulate those stormwater sources through MS4 permits. In West Virginia, EPA shifted

75% of the state’s animal feeding operation (AFO) load into wasteload allocation, meaning that sources could

potentially be subject to state or federal CWA permits as necessary to protect water quality if West Virginia does not

achieve reductions in agricultural loads from nonpoint sources, as identified in the WIP.

34

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

conservation management plans.36 The first milestones under the TMDL were submitted by states

in 2012.

The TMDL also reflects the view of many that nutrient trading can be a promising strategy for

meeting nutrient load limits in a cost-effective way. In water quality trading, sources with high

costs of reducing pollution can purchase equal or greater pollution reductions from sources with

lower costs. Entities with lower abatement costs are able to economically lower their pollution

discharge, enabling them to sell their excess reductions, while entities with higher abatement

costs benefit by meeting their abatement goals at a reduced price. Under this market-based

strategy, sources such as municipal wastewater and industrial facilities achieve their individual

load limits by purchasing load reductions from other sources such as farmers for a lower cost than

if the point source were to install technology on-site. Three states in the Bay watershed (and a

number of other states outside the region) have initiated nutrient trading programs, but little

implementation has occurred. In the Bay TMDL, EPA supports (but does not mandate) trading to

meet the plan’s nutrient reduction targets and to account for and manage new or increased

loadings in the future, and each of the Bay jurisdictions included nutrient trading in its Phase II

WIP.

Many supporters believe that trading has the potential to result in substantial overall cost savings,

but actual predictions depend on numerous considerations and uncertainty (e.g., required trading

ratios, potential tradeable loads, geographic scope of trading, transaction costs). Trading is also

seen as a means of encouraging agriculture’s participation in Bay restoration, since it has the

potential of generating new revenue for the agricultural sector (since a point source may pay a

farmer to reduce pollutants that the point source would otherwise have to control). It is generally

believed that installing measures to control agricultural sources of nutrients is more cost-effective

than, for example, urban nonpoint source practices such as street sweeping or installing urban

forest buffers.37 To support these types of efforts, USDA awarded $2.35 million to five projects in

FY2012 to promote water quality trading in the Chesapeake Bay watershed. The supported

projects are intended to help completion of state water quality market rules and organizations

needed to carry out trading between point sources and farmers and ranchers.

At the same time, some observers are cautious about the role of water quality trading in restoring

impaired waters, and states face numerous challenges about where to set parameters for what

constitutes credits and other issues. One assessment of nutrient trading in the Bay watershed

summarized both positive aspects of nutrient trading—such as potential to use market forces and

increase stakeholder support—and negative aspects—trading to reduce water pollutants is

technically complicated, interstate trading is hindered by differing state requirements, and

verifying results is difficult.38 Several groups that otherwise support the Chesapeake Bay TMDL

filed a lawsuit challenging the legality of the water quality trading portion of the plan, saying that

trading programs are filled with uncertainty and are vulnerable to nonpoint source owners selling

credits based on unverified pollution reductions. A federal court dismissed the challenge in

December 2013. The court ruled that the groups were unable to show that the previous trading

36

Chesapeake Bay Foundation and Choose Clean Water, “2011 Milestone Analysis Shows Progress,” July 9, 2012,

http://www.cbf.org/page.aspx?pid-3815.

37

RTI International, Nutrient Credit Trading for the Chesapeake Bay, An Economic Study, prepared for the

Chesapeake Bay Commission, May 2012.

38

Willamette Partnership, Pinchot Institute for Conservation, and World Resources Institute, In it Together: A How-To

Reference for Building Point-Nonpoint Water Quality Trading Programs, Case Studies (Part 3 of 3), July 2012, pp. 3244.

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

provisions within the TMDL plan to clean up the Bay were a final agency action that was being

forced upon states, but it did not rule on whether water quality trading is legal under the CWA.39

EPA’s TMDL and the overall federal Bay restoration strategy under the executive order are

controversial with a number of groups that are concerned about the likely mandatory nature of

many of EPA’s and states’ upcoming actions. A major concern is that the strategy will be very

costly to implement and will hamper the region’s economic recovery. Critics point out that EPA

has not prepared a cost-benefit analysis of restoring the watershed. EPA is now preparing such an

analysis, based on the Phase I WIPs, and expects to complete it by the end of 2012. Estimating

benefits is more complicated than estimating costs because of the difficulty of monitoring and

verifying results, according to EPA.

Implicit in much of the criticism of the Chesapeake Bay TMDL is concern that EPA will use it as

a model for developing similar large-scale TMDLs in other locations. As previously described,

EPA has developed and approved a number of multi-state TMDLs (e.g., the Northeast Regional

Mercury TMDL), but some observers worry that what they view as an aggressive and inflexible

TMDL strategy for the Chesapeake Bay will be replicated for other waterbodies.

Legal challenges to the TMDL were brought by agricultural and home builder groups, who argue

that EPA has exceeded its CWA authority (for example, by imposing detailed pollutant allocations

and using backup authority to strengthen WIPs) and impinged on the responsibilities of states to

assign pollution reductions to individual sources. They also question the science and accuracy of

computer models that EPA used in setting overall pollution limits. EPA contends that

development of the TMDL was well within its authority under the CWA, and the agency disputes

that it overrode state authority, noting that states were fully involved in the TMDL development

process. Several environmental groups and municipal water utility groups intervened on EPA’s

side in the litigation. In September 2013, a federal court rejected the legal challenge and upheld

the Bay TMDL.40 The court’s ruling has been appealed.

Environmental activists have expressed support that the federal government is finally asserting a

leadership role to restore the Bay and have endorsed legislation that would codify requirements of

the Bay TMDL in the Clean Water Act, while authorizing grants and other assistance for

implementing required measures. Companion bills to do so were introduced in the 111th Congress

(S. 1816 and H.R. 3852), but no legislation was enacted. The House Agriculture Committee also

approved separate legislation in the 111th Congress (H.R. 5509) that would have authorized an

expanded role for the Department of Agriculture in Chesapeake Bay restoration, to counter EPA’s

role in the TMDL. Legislation similar to H.R. 5509 was introduced in the 112th Congress (H.R.

4153). Congress has shown interest in the impact of the plan on agriculture through oversight

hearings by the House Agriculture Subcommittee on Conservation, Energy, and Forestry (on

March 16 and November 3, 2011).

39

Food & Water Watch v. United States Envtl. Prot. Agency, No. 12-01639, 2013 U.S. Dist. LEXIS 174430 (D.D.C.

Dec. 13, 2013).

40

Am. Farm Bureau Fed'n v. United States Envtl. Prot. Agency, No. 11-00067, 2013 U.S. Dist. LEXIS 131075

(M.D.Pa. Sept. 13, 2013).

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

Outside Assessments of the TMDL Program

Over the last decade, several assessments have recommended ways to strengthen the TMDL

program. One Government Accountability Office (GAO) report examined whether available

water quality data are sufficient to allow state officials to make key decisions about activities such

as identifying waters that do not meet water quality standards and developing strategies to address

those waters. Water quality data are so limited, particularly data for nonpoint sources, that many

fear that TMDL decisions will be based on unsound information and will impose unneeded or

inappropriate control mandates, according to GAO. Inconsistent monitoring, data collection, and

listing procedures used by states to identify impaired waters have hindered efforts to develop

effective TMDL programs, GAO found.41

In 2002, GAO issued a related report that examined the different approaches used by states to

identify impaired waters. Some of the approaches have no appropriate scientific basis, GAO said,

and states apply a range of quality assurance procedures to ensure the quality of data used to

make impairment decisions. GAO concluded that, because of inconsistencies in states’

approaches to identifying impaired waters, the information in EPA’s database of impaired waters

is of questionable reliability, and EPA cannot reliably tally the number of TMDLs that must be

completed nationwide.42

EPA’s responses to both reports are reflected in the Integrated Report guidance in place since

2004 (see “Administrative Developments”). It provides guidance on how states can document the

scientific and technical rationale for categorizing their waters, and it lists key elements that must

be included in states’ descriptions of their methodologies. In addition, in order to encourage a

long-term process of incremental improvement in state water monitoring programs, EPA

published a document recommending the basic elements of such a program.43

Following EPA’s controversial revisions of the TMDL program regulations in 2000 (which were

subsequently withdrawn in 2003), the agency’s FY2001 appropriation bill, P.L. 106-377, required

a study by the National Academies of Sciences (NAS) on the scientific basis of the program. The

NAS report, issued in 2001, concluded that scientific knowledge exists to move forward with the

program but recommended certain types of changes, such as utilizing iterative, adaptive

implementation and revision, as scientific data and information improve.44 EPA’s review of the

2000 rule after 2001 was at least partly to consider how to respond to those recommendations,

and many of the more recent TMDLs explicitly allow for and anticipate use of adaptive

management techniques.

In 2007, EPA’s Inspector General (IG) reported on TMDL implementation, particularly EPA’s

attention to information and systems to track and evaluate implementation. The IG found that a

lack of information prevents EPA from determining if TMDL implementation activities are

41

U.S. General Accounting Office, Key EPA and State Decisions Limited by Inconsistent and Incomplete Data,

RCED-00-54, March 14, 2000.

42

U.S. General Accounting Office, Inconsistent State Approaches Complicate Nation’s Efforts to Identify Its Most

Polluted Waters, GAO-02-186, January 11, 2002.

43

U.S. Environmental Protection Agency, Elements of a State Water Monitoring and Assessment Program, EPA 841B-03-003, March 2003.

44

National Research Council of the National Academies of Science, Water Science and Technology Board, Assessing

the TMDL Approach to Water Quality Management, June 2001.

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

occurring in a timely manner, and the extent to which TMDLs are restoring impaired waters. EPA

tracks specific outcomes—for example, numbers of TMDLs developed—but not functional

results of water quality improvement. The report noted that EPA has recently taken steps to

measure results and improve program data, including sponsoring studies of TMDL

implementation and evaluating additional results measures. These tasks are challenging, the IG

acknowledged, but the report urged EPA to provide more management direction to improve its

ability to assess how well the program is functioning.

EPA concurred with many of the IG’s conclusions, but responded in part that the agency has only

limited authority to require new post-TMDL monitoring, data tracking, and reporting. The IG had

recommended that EPA report annually on nationwide implementation activities, such as BMPs

completed and inclusion of wasteload allocations in point source discharge permits. EPA said that

“there are substantial cost and logistical implications of reporting annually and nationally on

TMDL implementation and TMDL environmental outcomes. After a point, tradeoffs between

level of effort invested in reporting and actually restoring impaired waters must be made by EPA

and the States.”45

A 2014 GAO report looked at a number of long-established TMDLs (i.e., approved more than

five years ago) to assess their status and the extent to which such TMDLs contain features that are

key to attaining water quality standards. GAO found that more than 80% of the reviewed TMDLs

have achieved their targets for point source pollution through permits, but that only 20% achieved

their targets for nonpoint source pollution. The absence of two key factors—legal authority and

sufficient funding—has generally stymied implementation of TMDLs meant to curtail nonpoint

source pollution, the report said. In a highly critical review, GAO also found that EPA’s existing

regulations do not explicitly require TMDLs to include key features, such as specifying how and

by whom TMDLs will be implemented and ensuring periodic plan revisions as needed. Without

such features in TMDLs, GAO said, impaired waterbodies are unlikely to attain standards. GAO

recommended that EPA issue new rules for TMDL development and that Congress should

consider revising the CWA’s largely voluntary approach to restoring waters impaired by nonpoint

source pollution.46

Factors Affecting Implementation

EPA and other stakeholders frequently point out that TMDLs are not the only approach to

restoring water quality and that TMDLs are sometimes inseparable from the combined effect of

multiple surface water protection program activities. TMDL implementation is only one of

several factors contributing to water quality improvements, and it is likely to be a small

percentage, the agency says. Other factors besides TMDL implementation could influence

whether a waterbody is in attainment with water quality standards, including new monitoring data

or a change in water quality standards, with data showing that the waterbody meets the new

standards.

45

Office of Inspector General of the U.S. Environmental Protection Agency, Total Maximum Daily Load Program

Needs Better Data and Measures to Demonstrate Environmental Results, Report No. 2007-P-00036, September 19,

2007, p. 17.

46

U.S. Government Accountability Office, Clean Water Act, Changes Needed If Key EPA Program Is to Help Fulfill

the Nation's Water Quality Goals, GAO-14-80, December 2013, pp. 65-66.

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

Further, states point out that there can be advantages and disadvantages of using TMDLs to

address impairments. Some say, for example, that relying on TMDLs is the right approach when

the problem and the source of impairment are unknown, and more scientific evidence is needed to

allocate pollutant reductions. Others say that doing TMDLs for some types of sources (e.g.,

agriculture) provides transparency and assurance to the public about what the state is doing to

improve water quality. But in view of the technical and resource challenges of doing TMDLs, in

some cases, alternative approaches may also be appropriate. For example, a state may lawfully

avoid listing an impaired water as needing a TMDL if it can demonstrate to EPA that other

pollution control programs provide reasonable assurance that water quality standards will be met,

such as imposition of point source permit limits, or state regulations and local ordinances for

nonpoint sources. However, this use of non-TMDL options is a relatively new idea and has been

little used. Some think that alternative approaches are more difficult to achieve than a TMDL.

One approach, in the state of Washington, is called “straight to implementation.” It involves

working directly with landowners, which enables actions to prevent pollution without first

developing a TMDL, especially when the state has clear enforcement authority over all types of

sources, including nonpoint. Also, a TMDL may not be necessary in cases where the source of

impairment is clearly known and control measures and funding are known and available.47

That said, when a TMDL is developed, implementation is a huge gap in the program for several

reasons. First, as noted previously, CWA Section 303(d) requires development of a TMDL for

impaired waters but does not require implementation. States’ strategies for implementation vary

widely. A 2008 survey determined that five states have laws requiring TMDL implementation

plans, either separately after the TMDL is approved or during development of the TMDL. In five

other states, formal implementation plans are not required, but are completed pursuant to state

guidance. In a third category are 15 states that develop implementation plans based on an

unwritten state initiative or rely on federal guidance. And finally, another 15 states have less

intensively developed implementation plans, which generally are a brief section in the TMDL

report. No information was found for nine states. The survey also examined how states implement

nonpoint source pollutant reductions. It found that 10 states have regulations to address some or

all types of nonpoint source pollution, while most states use incentive-based and voluntary

programs instead of a regulatory approach.48

Second, a number of barriers to TMDL implementation can be identified.49 The most prominent

hindrance is funding. The CWA provides no dedicated funding for TMDL development or for

implementation. Inadequate resources are cited as a problem for BMP implementation for

nonpoint sources, for point source upgrades such as wastewater treatment plants, for abandoned

mine land restoration, for staffing and technical expertise, and for data collection, modeling, and

follow-up monitoring. Technical impediments are a related challenge, such as insufficient

47

See Environmental Law Institute, National Workshop to Advance State TMDL Programs, Final Project Report &

Workshop Proceedings, November 2008, http://www.eli.org/pdf/tmdl/TMDL.FinalReport.pdf. Hereafter, National

Workshop.

48

Virginia Tech University, Biological Systems Engineering Department and the Center for TMDL and Watershed

Studies, State-Specific TMDL Implementation Information, September 2008, http://water.epa.gov/lawsregs/

lawsguidance/cwa/tmdl/upload/2009_09_09_tmdl_results_27_st_imp_info_va_tech.pdf.

49

See, for example, Brian Benham, Rebecca Zeckoski, and Gene Yagow, “TMDL Implementation: Lessons Learned,”

Proceedings: Water Environment Federation TMDL 2007 Conference, pp. 428-442, http://water.epa.gov/lawsregs/

lawsguidance/cwa/tmdl/upload/2009_09_09_tmdl_results_27_st_imp_info_va_tech.pdf; Environmental Law Institute,

State TMDL Program Resource Center, “State TMDL Program Snapshots,” http://www.eli.org/program_areas/Events/

StateTMDLProgramSnapshots.cfm; and National Workshop.

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

scientific data on the pollutant removal performance of BMPs for nonpoint sources, or inability to

link water quality impacts to sources or causes due to lack of data and understanding of pollutant

fate and transport.

At the same time, several factors that seem to aid effective implementation also can be identified.

These include active involvement of stakeholders and local and state governments; using a

diversity of approaches to address sources; existence of a watershed plan that is focused on issues

in the watershed and achievable through corrective actions; targeted or phased implementation;

and adequate resources to implement corrective measures, monitor progress, and provide

technical assistance.

Conclusion

After 40 years of implementing the CWA, 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. 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 yield more precise water quality

information and identify large numbers of waters requiring additional measures before water

quality standards are attained.

The TMDL program is in a period of transition. Many states are emerging from earlier consent

decree mandates and are increasingly addressing new challenges—for example, more complex

and resource-intensive TMDLs, larger scale impairments, and nonpoint sources. Whether the

program as it now exists is well suited to address problems such as ocean acidification or climate

change is debatable. In 2011, EPA and state program managers launched discussions of

developing new goals for the program. Two years later, these discussions produced a “vision

plan” for reforming the process, which includes allowing states the option to consider prioritizing

healthy waters, using alternative approaches that incorporate adaptive management, and

integrating TMDLs with other CWA and Safe Drinking Water Act programs.50

Other than recent oversight hearings on the Chesapeake Bay TMDL, Congress has not shown

active interest in the TMDL program for more than a decade. Some stakeholders, especially

states, believe that several issues present Congress with an opportunity to examine the TMDL

provisions of the CWA. Issues could include integrating TMDLs into a larger clean water

program that considers all steps—from designation of uses to implementation—in order to meet

water quality standards, recognizing and striking a balance between water quality restoration and

pollution prevention, changing focus from point sources to nonpoint sources, and addressing

resource and funding needs.

50

“New Vision for the CWA 303(d) Program—An Updated Framework for Implementing the CWA 303(d) Program

Responsibilities,” December 5, 2013, http://water.epa.gov/lawsregs/lawsguidance/cwa/tmdl/programvision.cfm.

Congressional Research Service

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Clean Water Act and Pollutant Total Maximum Daily Loads (TMDLs)

Author Contact Information

(name redacted)

Specialist in Resources and Environmental Policy

#redacted#@crs.loc.gov, 7-....

Congressional Research Service

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