NACWA Regulatory Alert (RA 05-08)

To: Members & Affiliates
From: National Office
Date: August 16, 2005
Subject: PROPOSED EPA TEST METHODS FOR BIOLOGICAL POLLUTANTS
Reference: RA 05-08

Action Please By:
October 3, 2005

The U.S. Environmental Protection Agency (EPA) has proposed in the August 16 Federal Register to issue new and revised test methods and techniques for analyzing E. coli and enterococci in wastewaters and fecal coliforms and Salmonella in sewage sludge. The proposed rule and a fact sheet are available on EPA’s website (http://epa.gov/waterscience/methods/). Comments on the methods are due October 17. Because the proposal affects publicly owned treatment works (POTWs), which must monitor to comply with National Pollutant Discharge Elimination System (NPDES) permit requirements, NACWA plans to submit comments on the proposed test methods and encourages members to do the same.

Proposed Methods for NPDES Compliance Monitoring
Membrane filtration (MF) and a suite of multiple-tube fermentation (MTF) methods would be available to monitor for E. coli and enterococci in wastewaters and fecal coliforms and Salmonella in sewage sludge as part of state and local monitoring programs, the proposal said. EPA said MF can be used on most tertiary treated wastewaters, but may have limitations where organism density may be underestimated, such as in water samples with high turbidity, toxic compounds, or large numbers of non-coliform bacteria. MFs may also have limited effectiveness where organisms can be damaged by chlorine or toxic compounds that can be found in wastewater that has received primary or secondary treatment. The proposal said if MF technology has not been used previously on an individual water type, a parallel test using MTF should be conducted to demonstrate applicability, lack of interferences, and at least comparable recovery.

MTF methods can be used to detect low concentrations of organisms, especially in samples with heavy particulate matter, toxic compounds, stressed organisms, or high concentrations of heterotrophic plate count bacteria. The MF method may be better in situations involving water soluble toxins. MTF would be applicable for sewage sludge analysis, the proposal said.

Again, NACWA will prepare comments by the October 17, 2005, deadline but needs member input regarding these test methods. Members can submit a copy of any comments to Susan Bruninga, NACWA Manager of Regulatory Affairs, at sbruninga@nacwa.org or to (202) 833-4657 by October 3, 2005, so that they can be incorporated into the Association’s comments.