Member Pipeline - Legal - November/December 2002 Legal Perspectives

Click Here
to see previous Issues

AMSA Legal Perspectives Logo

Volume I, Issue 8

November/December 2002

“ . . the procedures commonly used in analytical testing to measure the performance characteristic that is termed ‘accuracy’ cannot be applied to WET test methods.”
Preamble, Whole Effluent Toxicity Test Methods Final Rule, 67 Fed. Reg. 69,952 (Nov. 19, 2002)
 

Accuracy and reliability are important elements of any scientific protocol. And yet, the accuracy of the U.S. Environmental Protection Agency’s (EPA) whole effluent toxicity (WET) test methods – codified at 40 CFR Part 136 – has been questioned, challenged, and debated for nearly two decades. In November, EPA ratified several test methods for measuring the toxicity of effluents and receiving waters, withdrew two test methods, and revised other methods to increase confidence in the test results. 67 Fed. Reg. 69,952 (Nov. 19, 2002). EPA’s action was designed to satisfy obligations under a 1998 Settlement Agreement (Settlement Agreement) related to litigation over the original 1995 WET methods (60 Fed. Reg. 53,529) (Edison Electric Institute et al. v. EPA, No. 96-1062, D.C. Cir.).

Early reviews of EPA’s November action by leaders of AMSA’s Legal Affairs Committee and Water Quality Committee have found that many important and troubling WET issues remain unresolved by EPA’s final rule. In the coming weeks, AMSA and other organizations interested in WET policy will be evaluating a variety of avenues to address these outstanding concerns – including meetings with the Agency and potential litigation.

This issue of Legal Perspectives provides an overview of Clean Water Act (CWA) provisions authorizing WET testing, includes a brief history of WET regulation, outlines key WET issues of concern to publicly owned treatment works (POTWs), and offers a sense of where this complex regulatory program may be headed in the future.

The CWA and WET
The CWA mandates the use of two approaches to set effluent limitations in National Pollutant Discharge Elimination System (NPDES) permits – technology-based limitations and water quality-based limitations. Together, these limitations in a permit are designed to meet the statute’s goal of prohibiting “the discharge of toxic pollutants in toxic amounts.” CWA § 101(a)(3). The CWA’s definition of toxic pollutants refers to those pollutants, or combinations of pollutants, which after discharge either directly or indirectly cause, among other effects, death, disease, behavioral abnormalities, physical deformation, genetic mutations, and cancer. See CWA § 502(13).

Under the CWA’s requirement that states set water quality-based standards to protect their waters, most states have either a numeric or narrative criteria for WET. See generally CWA § 303. In WET testing, acute and chronic tests are performed on wastewater samples using surrogate organisms as test species. Exposure durations for the organisms range from a day or more for acute tests, to over seven days for chronic tests. The toxicity endpoints for acute tests are expressed as lethal or effect concentrations, while the chronic toxicity endpoints are expressed as the no-observed-effect and the lowest-observed-effect concentrations.

NPDES permits must contain WET limits where the permitting authority determines that the discharger has a “reasonable potential” to cause an excursion above numeric or narrative WET criterion. 40 CFR § 122.44(d)(1)(iv)-(v). WET limits in permits typically are expressed in numeric form as toxic units (TUs), and the specific pollutants creating the toxicity do not have to be identified. Thus, NPDES permits contain chemical-specific limitations, and if needed, WET limitations to stem the adverse effects of a combination of pollutants in the effluent.

Under the CWA, EPA must promulgate guidelines establishing test procedures for the analysis of any pollutants that must be included in permits. See CWA § 304(h).

EPA’s rulemaking efforts for WET have been designed to set and then to clarify those required procedures.

WET Regulatory History
EPA regions and states generally began effluent toxicity screening programs during the 1970s. In the mid- to late-1970s, EPA published various acute toxicity methods. Methods to detect long-term chronic effects on aquatic life, such as reduced growth and reproduction, were not widely used. In the 1980s, however, chronic methods became more readily available, allowing the detection of some adverse effects on freshwater and marine organisms in nine days or less.

In 1984, EPA published a national WET policy statement entitled “Policy for the Development of Water Quality-Based Permit Limitations for Toxic Pollutants” (WET Policy). 49 Fed. Reg. 9,016 (Mar. 9, 1984). The WET Policy recommended the use of toxicity data to assess and control the discharge of toxic pollutants to the nation’s waters through the NPDES program, and addressed technical approaches for doing so. EPA noted that in addition to enforcing pollutant-specific limits, EPA and the states would use biological techniques to assess toxicity impacts based on the general standard of “no toxic materials in toxic amounts.” The WET Policy was followed in 1985 by EPA’s first WET guidance, the Technical Support Document (TSD).

As WET policy matured, both the District of Columbia and Ninth Circuit Courts of Appeals reviewed and upheld EPA’s authority to measure and set toxicity limits without regulating specific toxic pollutants. NRDC v. EPA, 859 F.2d 156 (D.C. Cir. 1988); NRDC v. EPA, 863 F.2d 1426 (9th Cir. 1988). EPA’s 1989 surface water toxics control program rule both defined WET and described the procedures for determining whether a particular NPDES permit must include a water quality-based effluent limitation. 54 Fed. Reg. 23,868.

The 1989 rule only recommended protocols and guidance to perform WET tests. Later that year, EPA took a major step forward by proposing to add specific acute and chronic WET methods to Table IA, 40 CFR Part 136. 54 Fed. Reg. 50,216. While the rulemaking proceeded, EPA released additional guidance on the use of WET data in a March 1991 TSD (EPA 505-2-90-001), and updated the WET Policy in a 1994 guidance document (EPA 833-B-94-002).

POTW Involvement
AMSA and individual POTW water quality experts and scientists from across the nation were significantly involved in the WET methods development process. As more and more permitting authorities began to include WET limits in permits, POTWs and other NPDES permittees expressed concern that technical problems in WET methods raised questions about the methods’ accuracy and predictive capabilities. These technical limitations included the inappropriateness of various WET endpoints used in the methods; a troubling high degree of variability in the test methods; EPA’s failure to account for the many external factors that affect WET test results; and a general inability to draw clear relationships between effluent toxicity, overall ambient toxicity, and receiving water impacts attributable to WET. AMSA expressed that erroneous WET tests could result in costly and potentially unnecessary requirements for POTWs. While WET tests had a valuable role as informative tools, using them to set enforceable permit limits was questionable.

To respond to some of these concerns, EPA released a National Policy on WET Enforcement (Enforcement Policy) in August 1995. Under the Enforcement Policy, a single exceedance of a WET permit limit causing no environmental harm was not to be treated as a civil penalty violation. EPA clarified that citizens could not bring suits against a discharger on the basis of a single WET violation. EPA also noted that inconclusive toxicity reduction evaluations (TREs) – whereby a permittee after exhaustive investigation and application of appropriate controls still does not meet WET limits – should be resolved through technical support from EPA, rather than through enforcement.

Permittees continued to raise questions, however, about the unreliability of EPA’s proposed WET test methods. At AMSA and EPA’s suggestion, a technical workshop was held in September 1995 by the Society of Environmental Toxicology and Chemistry (SETAC) in Pellston, Michigan, to provide a forum to address these concerns. The Pellston Conference focused on pursuing answers and approaches to the acknowledged unresolved scientific and technical WET issues. In preparation for the Pellston Conference, AMSA members outlined key municipal WET concerns, noting that they “focus not on the concept of toxicity assessment, but on the use of technically demanding, resource- and expertise-intensive tests within the inflexible regulatory context of the NPDES program and its high liabilities for test exceedance.” Discussion-Initiation Paper 2.3, Whole Effluent Toxicity Testing: The Municipal Perspective, P. Ruffier, p. 38 (SETAC, 1996). The Pellston Conference attendees made many conclusions and recommendations regarding WET methods, highlighted needed guidance and training, and identified research needs important to strengthen the scientific and regulatory commmunities’ understanding of the value of WET tests.

Within weeks of the Pellston Conference, EPA finalized the 1989 proposed WET test methods, requiring that all WET testing be conducted according to the codified protocols. 60 Fed. Reg. 53,529 (Oct. 1995).
Litigation over the final methods was immediately filed, resulting in a stalemate on WET permitting activity in some EPA Regions, and having no effect in others.

After significant negotiations, EPA agreed under the 1998 Settlement Agreement to: publish a technical correction notice and method guidance and variability guidance documents; conduct an interlaboratory variability study and publish a peer-reviewed report on the study; address pathogen contamination; propose specific technical method changes; and ratify or withdraw test methods evaluated in the study. AMSA assisted in identifying laboratories for EPA’s interlaboratory study.

EPA then published a proposed rule to address these issues in September 2001. AMSA and other stakeholders provided extensive comments in January 2002. EPA asserts that its November 2002 final rule completes the Agency’s rulemaking obligations in response to the litigation.

WET Method Concerns for POTWs
AMSA’s January 2002 comments on EPA’s proposed WET method changes carried a message consistent with years past. Again, AMSA encouraged EPA to use WET tests as an investigative tool rather than as a basis for enforceable permit limits. AMSA emphasized that since toxicity is a method-defined pollutant, accurate WET methods are critical. AMSA’s comments and those of the AMSA-supported multi-association WET Coalition, noted that:

AMSA’s comments conclude that the numerous legal and technical deficiencies of the WET methods “underscore AMSA’s position that the WET test methods have not been proven to be sufficiently reliable for use in setting enforceable NPDES permit limits.”

It also was apparent to AMSA that EPA’s proposed rule did not address additional key issues of concern to POTWs. These issues included how WET limits would be incorporated into permits; how EPA and the states would use the “reasonable potential” test to determine if a permittee should receive a WET limit; and how EPA would set data quality objectives (or “acceptance criteria”) to determine whether WET data are suitable for their intended purpose. Because EPA viewed these issues as relevant to the implementation of WET policy, rather than as inherent to the methods themselves, AMSA and the WET Coalition raised these concerns in meetings with EPA, and expanded upon these issues in discussion papers submitted to the Agency in May 2002.

The Future
Now that EPA’s final Part 136 methods are available to the states, WET limits will become more common in many POTW NPDES permits. And yet, AMSA’s initial review of EPA’s November 2002 final action reveals that EPA did not meaningfully address our significant and longstanding concerns. The changes EPA made in its November rule do not enhance in any way the accuracy of the WET test methods – particularly the chronic, sub-lethal methods.

EPA continues to assert that the majority of AMSA’s remaining concerns can be addressed and resolved through reasonable WET implementation and enforcement discretion. Whether this is an acceptable solution for POTW WET concerns is unclear. In the coming weeks, AMSA will be evaluating EPA’s final WET action in more detail. In addition, we have scheduled a meeting with the Office of Water for early January to discuss these issues once again. It is likely, however, that protective petitions for review of EPA’s November rulemaking will be filed to, at a minimum, give POTWs and other stakeholders more time to explore resolutions to these longstanding concerns with the Agency.

© 2002 Association of Metropolitan Sewerage Agencies

Legal Perspectives is a monthly publication of the Association of Metropolitan Sewerage Agencies (AMSA).

Founded in 1970, AMSA represents the interests of over 270 of the nation's POTWs. AMSA members serve the majority of the sewered population in the United States and collectively treat and reclaim over 18 billion gallons of wastewater everyday.

AMSA welcomes comments on Legal Perspectives. Please contact Alexandra Dapolito Dunn, General Counsel, at adunn@amsacleanwater.org or 202/533-1803.