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Are TDMLs the Answer to The contrasting views of two analysts highlight underlying
Making TMDLs Work Further consideration of underlying science and policy issues is needed for the program to work better. T A M A R A S A LT M A N
For many people who work with them, TMDLs have become a dirty word. In fact, more people probably think “too many d*@! lawyers” when they hear the abbreviation than think “Total Maximum Daily Loads”. There is more to the story, however. TMDLs are also about science and policy. Simply put, thinking in terms of TMDLs (see sidebar on page 252A, (1)) changes not only the questions that regulators, policy developers, managers, and scientists need to ask about water quality protection, but also the data requirements and conceptual frameworks needed to answer them. U.S. water resource protection has been transformed by TMDLs from a source-by-source approach to an approach dictated by ecological health and function, or at least some proxy of those things. Already, they are changing which water pollution sources are controlled and how they are controlled. The shifting focus is creating new challenges for scientists whose work is relevant to environmental management issues and whose best efforts and hard-earned wisdom need to be included in the public debate about what TMDLs are, why they are important, and why good minds should contribute to the TMDL process.
Concerns about TMDLs have led to lawsuits, many of them citizen suits that are aimed at pushing public policy and management. At this writing, the U.S. EPA has been sued in 35 states, mainly by citizens’ groups, over its failure to complete one or more of the steps of the TMDL process (approve lists, approve TMDLs, or complete federal TMDLs). Lawsuits have also been filed (www.epa.gov/owow/tmdl/lawsuit. html) by industry stakeholders and other groups who feel threatened by the development and implementation of TMDLs (2). The lawsuits prompted EPA to issue a new TMDL rule in July 2000, but after holding hearings on the issue, Congress blocked the agency from implementing it. A court of law is not the most efficient or congenial place to hammer out environmental policy, but 248 A
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Lawsuits as policy drivers
© 2001 American Chemical Society
Water Quality Protection?
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concerns about science, policy, and data quality.
TMDL at the Crossroads Unless critical data needs are addressed, the Total Maximum Daily Loads will not be supported by sound science. R AY W H I T T E M O R E A N D G E O R G E I C E
A crisis is looming. Although the Clean Water Act (CWA) was passed in 1972, many U.S. water bodies still do not meet its water quality standards. The CWA’s Total Maximum Daily Load (TMDL) program addresses this problem but requires an undertaking of staggering proportions. Within the next 10–15 years, 40,000 TMDL assessments will have to be carried out and approved by EPA for 20,000 water bodies nationwide. This, the most comprehensive reevaluation of water quality since CWA’s passage, has left both the regulated and regulators alike scratching their heads and wondering just what exactly can be accomplished and how. A TMDL, essentially a mass balance of a pollutant flowing in and out of a watershed, calculates the maximum amount of contaminant that a water body can receive and still meet applicable water quality standards. The calculated total is allocated over all sources of the pollutant so that in sum, these do not exceed the maximum. In principle, if pollutant source releases are held to within the specified allocations, water quality objectives are satisfied. Section 305(b) of the CWA requires states and other jurisdictions to submit water quality reports to the U.S. EPA. Under Section 303(d), they are required to identify waters not attaining water quality standards, submit a list to EPA of those impaired waters, and develop TMDLs for them. EPA and its partners are working together to develop a consolidated 305(b)/303(d) assessment approach that will streamline and improve these two reporting requirements. With state and federal resources for monitoring water quality diminishing, the workload required to develop TMDLs could result in poor decision making. Progress could be further hindered, if the courts, in responding to lawsuits filed by environmental groups because of the perceived slow pace of the program, requires TMDL development at a rate that does not allow for comprehensive, accurate, and defensible assessments. An additional complication is that monitoring data needed to support assessment decisions are inadequate. These issues, as well as the models © 2001 American Chemical Society
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as the Clean Water Act (CWA) acknowledges in authorizing citizen suits, it is sometimes the only place. There are consequences, however: Court deadlines almost always push managers and scientists to make decisions about TMDLs sooner than they would feel comfortable making them. Sometimes this is a good thing—one could go on collecting data forever, but at some point, a decision has to be made on the basis of available knowledge. At other times, deadlines can be damaging—decisions made with too few data under great pressure do not always turn out to be wise ones. Especially because of this latter point, scientists should make every possible effort to contribute whatever wisdom they have gained in their careers to improving the TMDL process. It will be a loss to all if such participation is not forthcoming.
A new paradigm The TMDL program represents a turning point in policy and management practices aimed at providing protection of water resources. To understand what is different, controversial, and perhaps paradigmchanging about TMDLs, it is necessary to examine the current CWA structure. In most places, there is a wall between point and nonpoint sources in the CWA (3). Point sources can be regulated by the federal government or by delegation of federal authority to the states. Regulation usually takes the form of National Pollutant Discharge Elimination System (NPDES) permits. Primary direct control of nonpoint source discharges, however, is through state law, mostly implementation of voluntary measures called best management practices. What makes the TMDL program different is that it appears to allow or even force states to require nonpoint sources to reduce the amount of pollution they generate. This is because the TMDL rule requires the pollutant budget to be allocated among all sources. EPA, states, and the courts have interpreted allocation among all sources to mean point, nonpoint, and atmospheric deposition sources. The program has its limits, however; because the TMDL program does not
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contain any new authority, states must implement TMDLs using their existing authorities. Many stakeholders, formerly unregulated nonpoint sources, in particular, consider this an instance of the federal government putting its long regulatory arm where it has never been and where it does not belong. This however, is an unfair characterization of EPA’s role. First, each state has its own process for developing TMDLs, which includes participation from any and all interested parties. At the conclusion of that process, it is the state, not EPA, that decides how to allocate pollutant loads among sources. EPA does not approve or reject TMDLs on the basis of how much is allocated to which sources. Rather, approval depends on whether the TMDL contains all the required pieces and whether, if implemented, the allocations are reasonably expected to get the water body clean enough to meet the water quality standard(s) that it is violating. The only instance in which states do not have a choice about whether to regulate nonpoint sources is if they are the only sources impairing a waterbody. Second, and not a small matter, the distinction between point, nonpoint, and atmospheric sources in the CWA was created in a different era. At that time, point sources were clearly causing huge water quality problems. Nonpoint sources were considered a “local” problem, and the law as developed gave little indication that the cumulative impacts of nonpoint and atmospheric sources were well understood (2). We are no longer in that era. We now know that nonpoint sources are the most important sources of water quality impairments in most water bodies nationwide (4). It is therefore now reasonable to have a national discussion about whether current regulatory authority is adequate and whether there is an appropriate distribution of authority among federal, state, and local levels, to address this problem. TMDLs appear to be triggering this discussion. Answers remain elusive, but whatever the outcome, it will be better for all stakeholders if informed science is an integral part of the discussion.
Atmospheric deposition Atmospheric deposition of pollutants is a well-known phenomenon in the scientific community, but it is only just beginning to be acknowledged in management circles. It has often been left out of TMDLs, perhaps because of its new relevance to the issue, the complications it raises, or the result of conventional practice. That omission is no longer possible: The new rule requires that TMDLs be performed for water bodies impaired primarily or exclusively by atmospheric deposition (1). This requirement has created a huge need for atmospheric deposition data, a need that is far greater
TMDL at the Crossroads / Ray Whittemore and George Ice
used for developing the TMDLs, were examined at the Watershed 2000 conference last July, and participants noted that the TMDL program is in critical need of sound science support. Addressing this challenge will require developing and implementing effective modeling and monitoring strategies. A watershed protection approach could be an effective strategy for protecting and restoring aquatic ecosystems and protecting human health, but, as currently implemented, differs little from earlier command-and-control scenarios. TMDLs have been characterized as more science-based than discharge permit allocations (1), but this distinction currently has little to do with sound science—TMDLs largely depend on modelers and having sufficient resources to check calculations. More robust model calibrations are needed. Decisions at a watershed scale must balance between being too detailed, overly expensive, and cumbersome to apply, versus being so reductionist that processes and watershed information are truncated to the point that control options and management opportunities are missed.
Information weaknesses The TMDL program depends on three elements: a listing process that prioritizes water bodies to be studied; models and associated data to develop and verify the allocations for achieving compliance; and long-term monitoring data that tests management decisions. These elements all suffer from the paucity and mixed quality of watershed and water quality information available to states (2). There are also inadequate historical monitoring data to support modeling efforts. Default data are often used, a practice that is not sound science. The status of water quality listing requirements is in flux. EPA is reviewing the requirements as part of its Consolidated Assessment and Listing Methodology. This guidance document, which includes modules for monitoring objectives, design, and quality (see www.epa.gov/owow/monitoring/calm.html), should be available for use in the 2002 listing cycle. An available TMDL tracking system database indicates listed waters, causes of impairment, and TMDL status (www.epa.gov///OWOW/tmdl/trcksys. html). Previously, this information was not available at a national scale in an easily accessible and consistent electronic format. Additional state-specific TMDL information is also available (www.epa.gov/OWOW/ tmdl). This includes program caveats, analysis tools, and reports detailing how the load estimate was developed and what monitoring was required. In some cases, states have developed TMDL tracking information comparable to the EPA effort. Program costs are a concern. A National Council for Air and Stream Improvement study (3) estimated
that modeling costs would exceed U.S. $5 billion if all currently listed water bodies are assessed as mandated by the CWA. The cost issues will be difficult to address because the models are needed to assess water quality conditions in relation to established standards and to investigate possible reductions in pollutant sources to meet water quality standards. Even these standards may be inappropriate for dynamic nonpoint sources, especially in headwater reaches (4).
An implementation nightmare? Although EPA’s initiative to develop the TMDLs and protect watersheds is nearly 20 years old, a defensible water quality monitoring program for developing credible watershed assessments has not been forthcoming. To meet the remaining challenges, EPA has promoted a more holistic, location-specific approach to river management involving local stakeholders. The approach, which began in 1991, is based upon the principles that continuous watershed improvement requires sound science and that watersheds transcend political, social, and economic boundaries and are nature’s boundaries. TMDLs surviving stakeholder scrutiny and approved by EPA will have credible supporting data that document water body impairment. EPA’s vision is to achieve clean and healthy watersheds that support aquatic life and important human uses. Encouraging and maintaining comprehensive water resource management tailored to meet local needs rather than a one-size-fits-all approach will help meet this vision. The Clean Water Action Plan (http://cleanwater.gov/anniv2/intro.html), released February 1998, describes the agency’s vision. The watershed initiative has fostered the development of innovative assessment methodologies and created new and often contentious stakeholder issues related to the program’s integrity, for example, establishing credible water quality standards, prioritizing watershed assessments, balancing between monitoring and modeling, trading pollutants, and balancing water quality socioeconomic considerations against ecological health. These and other concerns face off in the TMDL arena, pitting industry, regulatory agencies, nongovernmental organizations, environmental groups, and the public against each other.
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than the information available to fill it. Notwithstanding the deficit, neither the law nor court rulings to date allow lack of information to keep TMDLs from being completed. Arizona, Louisiana, Florida, Wisconsin, North Carolina, and South Carolina have developed (or are in the process of developing) TMDLs for waterbodies primarily impaired by atmospheric deposition of mercury, and Florida, Delaware, and North Carolina have each identified atmospheric deposition of nitrogen as a pollution source to consider in developing TMDLs. Some of these were done in response to legal pressure, but some were not. The court pressure is not necessarily a bad thing. A lot is already known about atmospheric deposition, and it can be negligent to wait until we know everything before doing anything. Where information is lacking, the scientific community should consider what else can be done or if this is the best it can offer.
Regulatory options There are several possible ways for atmospheric emissions to be regulated to protect water quality. Perhaps the simplest option for controlling atmospheric deposition is through national or regional across-theboard regulation that addresses equity issues by ensuring that all communities are equally protected. This approach would not require the complex and expensive source–receptor modeling used in formulating source-by-source controls. It also gives populations living downwind confidence that upwind
The TMDL process TMDLs are addressed in a formerly obscure section (303(d)) of the 1972 Clean Water Act (CWA) and are intended to bridge the gap between point source water quality controls and clean water—the former does not always guarantee the latter. This bridging is accomplished through a simple mass balance and budgeting exercise. The total safe pollution load for each impaired water body (one that does not meet standards) is set, and all pollution sources are allocated a portion of that load. In principle, when each source does what is necesary to meet their budgeted load allocation, the water will be protected. There are two distinct steps to completing a TMDL. The first is called listing. States place waters identified as impaired on a list called the 303d list. The second step is for states to develop the TMDLs according to a schedule. Separate EPA approval is required for both steps: EPA first approves the list, then approves the TMDLs for those listed waters. EPA has the power both to add waters to state lists and to perform the TMDL if the state does not submit an approvable TMDL. Under a new, but as yet unimplemented TMDL rule finalized in July 2000, states would have up to 15 years to complete all TMDLs and must update their 303d lists every 4 years. Each TMDL must contain, among other things, an implementation plan for how the load allocations (for nonpoint sources) and wasteload allocations (for point sources) will actually be reached. There is no time limit (other than public or political will) on how long it can take to implement an approved TMDL (1).
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sources in other states will make the necessary changes. This approach has been used to control acid rain under Title IV of the Clean Air Act (CAA) and has been effective in achieving the legislated emissions reductions. EPA announced in December 2000 that atmospheric emissions of mercury from coal- and oil-fired power plants will be limited because the mercury is deposited into ecosystems where it makes its way into fish and then into humans. Other national and regional air legislation includes improving water quality as a secondary benefit, for example, the 1997 ozone and fine particulate matter National Ambient Air Quality Standards and the 1998 NOx State Implementation Plan call that will reduce summertime NOx emissions in the eastern United States (5). The primary disadvantage of across-the-board regulations is that it is difficult, if not impossible, to create a reasonable national standard that will reasonably solve specific water quality problems in all locations. For any authority to protect all water bodies, it must be able to respond to local and regional needs for water quality control protection measures. One way to do this is to reduce emissions on a source-by-source basis as needed. The federal government’s residual risk authority allows it to do this for air pollution sources that emit hazardous air pollutants (HAPs), including mercury but not nitrogen. Before activating this authority, the CAA requires Maximum Achievable Control Technology (MACT) performance standards to be promulgated for the source category. Within eight years of promulgating a MACT standard, EPA must evaluate whether there is remaining or “residual risk” from those sources. If so, EPA must issue residual risk standards that are tighter than the MACT standard. EPA has reserved the right to apply residual risk standards on a fine scale, for example, a particular air emissions source that is causing a particular water quality impairment. Such fine-scale application has not been tested because EPA has not yet proposed any residual risk standards. This may be the best authority to enable impaired water bodies to recover in some cases, but in others, the cost of proving what harm a particular source causes to a particular water body may be prohibitive. The long time lag between recognizing a problem and applying a residual risk remedy is also a significant problem. In seeking to manage atmospheric deposition, EPA’s approach has often been to rely on secondary benefits from existing national regulations and to ask states to require whatever additional reductions are needed. This can be done under state law within their borders or through agreements with neighboring states. There are few examples, however, of states achieving desired benefits by reducing their own pollutant emissions when emissions are still arriving from out-of-state. Moreover, states have rarely been successful in convincing upwind neighbors to send
TMDL at the Crossroads / Ray Whittemore and George Ice
One of the most fully developed examples of a watershed approach is Watershed Analysis (WA), which is part of the Washington Forest Practices program. WA was developed to assess the cumulative watershed effects of forest practices, especially those that might affect salmon. WA involves a series of formal modules that assess management hazards imposed on the watershed and resources at risk. Watershed inventories and analyses are conducted by professionals trained in WA, and managers develop solutions to the identified problems. A Washington Forest Practices Board manual of Standard Methodology for Conducting Watershed Analysis provides detailed guidance on assessing for mass wasting, surface erosion, hydrology, riparian functions, stream channel conditions, fish habitat, water quality, water supplies and public works, and watershed routing (5). After a WA is completed and watershed-specific management requirements (forest practice rules) are adopted, a monitoring program is implemented to confirm that hypotheses about the watershed were accurate, and watershed objectives are being achieved. Regrettably, use of WA in Washington has significantly declined because landowners have been unwilling to endure the time and expense of conducting a WA, only to have further assessments required as part of the TMDL process.
Too few data An Environmental Science & Technology editorial (6) notes an over-reliance on modeling in environmental decision making and suggests that more monitoring data are needed to restore good scientific principles. Although modeling and monitoring are strongly related, one should not be excluded at the expense of the other. The alarming trend noted at the Watershed 2000 meeting is that monitoring is being replaced by modeling. To address data issues and assist states in overcoming TMDL assessment backlogs, EPA provides a multipurpose environmental analysis system, the BASINS toolkit (www.epa.gov/y2k/basins.html). However, Beebe et al. (7) contend there are insufficient data to use the system to perform credible TMDLs in some watersheds. The study notes that users of the BASINS toolkit sometimes have to find alternative data sources or rely on BASIN’s Append Water Quality Observation Data Utility to address data shortcomings. EPA offers training to address these critical information deficits, but the Beebe et al. study suggests this service is inadequate. Beebe et al. also find that at the watershed scale, the data resolution used by the BASINS toolkit is inadequate, and it lacks water quality data for many of the watersheds examined. In addition, BASINS uses data in which the average watershed has 5.4 water quality stations averaging 50 miles apart with sta-
tions closest to the pour point (the lowest elevation point along the boundary of the watershed) accounting for
