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Recent Judicial Decisions on TMDL Implementations: What Every Discharger should know

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The Clean Water Act requires that wastewater discharges achieve instream water quality objectives that are “necessary to protect public health and the environment.” See, Leather Industries of America v. EPA 40 F. 3d 392 (D.C. Cir 1994). Such water quality objectives may be expressed as either numeric or narrative standards. For TMDL purposes, the implementation of numeric standards should be rather straightforward as the precise level of acceptable water quality is known. Narrative criteria, however, provide no objective basis for determining compliance and are required to be converted into a numeric value for TMDL calculation purposes.

Recently, both the federal and state regulatory agencies have begun to impose very restrictive TMDLs for a range of pollutant parameters based upon alleged exceedances of numeric and narrative criteria. Such narrative criteria are often related to a “balanced indigenous population,” “excessive nutrient enrichment,” “organic enrichment,” or “excessive sedimentation.” Requirements for detention ponds and other storage facilities will be mandated based upon these TMDLs for many communities. Numeric violations may be related to concerns arising under wet weather or average flow conditions, but are used to impose more restrictive limits on point sources during low flow conditions. Putting aside the issue of whether such impairment actually exists in such waters, the degree of control required through such TMDLs often does not properly implement the Clean Water Act and applicable regulatory requirements (e.g., 40 CRF ยง131.11).

In addition, generic issues appear to arise in most TMDLs relating to “margin of safety,” “reserve capacity,” reinterpretation of existing standards, period of application and regulation of deminimus sources. Depending upon the state or regional office conducting the TMDL, arbitrary factors that further restrict allowable discharges are included by invoking the mantel of “best professional judgment,” “uncertainty,” or “margin of safety.” Case law has been clear that such assertions must be supported and be grounded in analysis of the actual risks involved. Moreover, such conclusions are, in general, inconsistent with EPA's prior pronouncements that the steady-state modeling methods typically employed by states are extremely conservative, such that an additional margin of safety is not needed to ensure water quality standards compliance.

Reinterpretation of standards has been two-edged sword. While flexibility inherent in existing standards associated with natural conditions and the need to only regulate the “toxic fraction” of a pollutant (40 CFR 131.36 (metals) are often overlooked (contrary to numerous decisions including National Gypsum v. EPA (DC Cir. 1992)) federally approved TMDLs lists have also been overturned where the precise language of the existing rules (e.g., no exceedance “at any time”) has not been fully implemented (Florida PIRG v. EPA, (11th Cir, 2004)). Thus, certain TMDL decisions may be under or over protective, depending upon how the permitting authority has chosen to interpret its TMDL responsibilities.

This paper will review the legal requirements associated with proper implementation of numeric and narrative criteria under the TMDL program. Several case studies where improper implementation has occurred will be reviewed as will the options for affected parties to achieve more appropriate results.

Document Type: Research Article


Publication date: 2006-01-01

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