One of the more contentious issues for POTW wastewater dischargers has been the imposition of general use water quality and effluent limitations for discharges to low-flow or intermittent streams and other limited water bodies. For example, some wastewater treatment plants discharge to stream segments that may have only wet weather flows, where the 7-day, 10-year low flow is zero in the absence of the discharge.
If such treatment plants are required to upgrade treatment processes to meet general use "fishable/swimmable" standards, it can be argued that the costs of such an upgrade may exceed any benefits to the stream environment. A recent federal district court decision focuses on this very issue. Idaho Mining Association Inc. v. EPA, 50 ERC 2000 (D. Idaho 2000).
Several conclusions arise from the Idaho Mining decision.
• In setting standards under the Clean Water Act, there is a presumption that all stream segments can attain fishable/swimmable uses.
• Water quality and effluent standards can be established based on this presumption.
• However, this presumption can be rebutted by a use attainability analysis.
• Lesser use designations for stream segments can be established based on use attainability analysis.
• Economic factors (cost-benefit analysis) may be an integral component of use attainability analysis, where a lesser use designation is proposed for a stream segment.
• Less stringent water quality and effluent standards can be established when a lesser use designation is made.
In the Idaho Mining case, the Court stated that it "will determine whether the EPA’s decision to promulgate a rule establishing aquatic life designated uses for three water bodies in Northern Idaho based on a rebuttable presumption that such uses are attainable was arbitrary and capricious, an abuse of discretion, or otherwise not in accordance with law." 50 ERC 2006. The Court held that EPA’s designation of cold water biota uses for Shields Gulch was an abuse of EPA’s discretion. The only evidence in the record was that the "stream" was dry on the day it was sampled. "The EPA had before it no other biological, chemical or physical data concerning the suitability of Shields Gulch for cold water biota." 50 ERC 2023.
The Court noted that EPA did not have an affirmative obligation to obtain evidence to justify its aquatic life use designation. "However, EPA was required to consider any relevant data it had before it during the rulemaking process to determine whether the presumption of aquatic life attainability had been rebutted. In this case, the Court agrees with Plaintiff that all of the data, or lack thereof, pointed to the conclusion that cold water biota uses are not attainable in Shields Gulch, or at least as the record now stands." 50 ERC 2023.
The Court went on to say, "Defendants have been unable to point to a single citation in the administrative record to support their assertion that water flows in Shields Gulch for even part of the year. Furthermore, even assuming that Shields Gulch does experience seasonal water flow, there is no evidence in the record as to how many months of the year the water flows, the rate of flow, the ambient water quality or the suitability of the water for fish and other aquatic species. Based upon the foregoing, the Court finds that the EPA abused its discretion when it designated Shields Gulch for cold water biota uses. In light of the fact that the only data before the EPA indicate that there was no water in the stream segment to support aquatic life uses, it was arbitrary and capricious for the EPA to have determined that the presumption of fishable/swimmable use attainability had not been rebutted for this particular stream segment." 50 ERC 2023—24.
A significant inference from the Idaho Mining decision is that some measure of common sense should prevail in the setting of water quality and effluent limits by both state environmental agencies and U.S. EPA. In the case of POTWs, whether municipal-owned or investor-owned, ratepayers likely will ultimately bear the burden of any unnecessary plant upgrades to meet higher-use standards. Therefore, POTWs may have an obligation to seek site-specific stream segment standards, based on lower use attainability, when discharge streams may not be capable of attaining general use fishable/swimmable status.
For example, rather than the POTW discharge, low flow, poor habitat, channelization, erosion, siltation, littering, impoundments, contaminated agricultural or urban run-off and other influences may be the limiting factors for the stream and bar recreational uses or any significant aquatic life. If habitat cannot sustain fish or aquatic life to feed fish downstream, or if a stream is only a few inches deep, fishable/swimmable may be an impossibility. In such circumstances, the cost of plant upgrades likely will outweigh any benefits to stream segment uses. The existing POTW discharge may have no material impact on actual or potential uses.
Accordingly, POTWs have the opportunity and obligation to challenge the fishability/swimmability high use attainability presumption, when appropriate. To do so requires a POTW to initiate a thorough study, by an expert consultant of the stream segment involved, the impact of the existing discharge on present and potential uses and a cost/benefit analysis of upgrade versus non-upgrade.
Also required is the courage to sustain the challenge through both administrative and judicial proceedings, with the objective of presenting as thorough and detailed a record in support of the POTW’s position as possible. The Idaho Mining decision teaches that to show that a regulatory agency has abused its discretion in setting a use designation or standard, the challenger must prove that the agency has disregarded cogent evidence and common sense.