NACWA Regulatory Alert (RA 06-09)

The U.S. Environmental Protection Agency (EPA or Agency) recently released several items relating to the implementation of its 1986 bacteria criteria, which are based on Escherichia coli (E. coli) and enterococci as indicators of bacterial contamination. Most critical is the final approval of analytical test methods for the enumeration of E. coli and enterococci in wastewater matrices and Salmonella and fecal coliform in biosolids. NACWA has long criticized EPA’s implementation of the 1986 bacteria criteria without approved test methods for evaluating the indicators in wastewater effluent. NACWA has also criticized EPA over the lack of implementation guidance for the 1986 criteria. Two new fact sheets developed by EPA Headquarters provide limited guidance on implementing discreet elements of the 1986 criteria, with a specific focus on the application of the 1986 criteria in the Agency’s November 2004 promulgation of bacteria criteria for coastal recreation waters in certain states. Prepublication versions of the new test methods and the associated Federal Register notice are available on EPA’s website (http://www.epa.gov/waterscience/methods/). The fact sheets are also available online (http://www.epa.gov/waterscience/criteria/humanhealth/microbial/index.html#wqs).

Much of the Agency’s recent work relating to the 1986 criteria, including the November 2004 establishment of criteria for certain coastal waters, involves EPA’s efforts to meet provisions of the Beaches Environmental Assessment and Coastal Health (BEACH) Act of 2000. NACWA continues to question the validity of the 1986 criteria and the Association’s Board of Directors recently approved NACWA’s intervention in litigation surrounding the BEACH Act to ensure the Association has a seat at the table in anticipated negotiations. The Natural Resources Defense Council (NRDC) is suing U.S. EPA over its failure to meet certain BEACH Act deadlines, and NACWA will intervene to help ensure EPA has adequate time to establish reasonable, scientifically sound standards.

New Test Methods for Bacterial Indicators
EPA has finalized test methods for measuring E. coli and enterococci, the key indicator organisms in the Agency’s 1986 bacteria criteria, in wastewater effluent. The new methods, listed below, use culture-based approaches to detect enterococci and E. coli in wastewater. Additional tests identify Salmonella and fecal coliform bacteria in biosolids. The approved methods are:

• EPA Method 1103 - Escherichia coli (E. coli) in Water by Membrane Filtration Using membrane-Thermotolerant Escherichia coli Agar (mTEC)

• EPA Method 1106 - Enterococci in Water by Membrane Filtration Using membrane-Enterococcus-Esculin Iron Agar (mE-EIA)

• EPA Method 1600 - Enterococci in Water by Membrane Filtration Using membrane-Enterococcus Indoxyl-β-D-Glucoside Agar (mEI)

• EPA Method 1603 - Escherichia coli (E. coli) in Water by Membrane Filtration Using Modified membrane-Thermotolerant Escherichia coli Agar (Modified mTEC)

• EPA Method 1680 - Fecal Coliforms in Sewage Sludge (Biosolids) by Multiple-Tube Fermentation using Lauryl Tryptose Broth (LTB) and EC Medium

• EPA Method 1681 - Fecal Coliforms in Sewage Sludge (Biosolids) by Multiple-Tube Fermentation using A-1 medium

• EPA Method 1682 - Salmonella in Sewage Sludge (Biosolids) by Modified Semisolid Rappaport-Vassiliadis (MSRV) Medium

Several NACWA members involved in the validation of these methods had expressed concerns with Method 1600’s false negative rate. Additional validation work was done to try and address this concern, but it is unclear at this point whether these concerns were addressed in the final methods. NACWA will be reviewing the methods in more detail to determine if there are lingering issues associated with the false negative rates or other concerns regarding the use of these new methods.

Fact Sheets Provide Guidance for Coastal State Implementation of 1986 Criteria
In accordance with the BEACH Act, EPA promulgated bacteria criteria (based on the 1986 criteria) for coastal recreation waters in those states that had not yet developed their own criteria that were as protective as EPA’s. NACWA provided substantial comments (http://www.nacwa.org/getfile.cfm?fn=2004-08-09OW_2004_0010.pdf) on EPA’s proposed promulgation and prepared a Regulatory Alert (http://www.nacwa.org/private/regalerts/ra04-18.cfm), including a list of the affected states, on the final November 2004 rule. The two fact sheets, both dated August 2006, were developed to provide guidance on implementing EPA’s November 2004 rule, but they also provide insight into EPA’s current approach to implementing its criteria in states not impacted by the BEACH Act.

Fact Sheet – Considerations for States as They Select Appropriate Risk Levels
The first fact sheet, Considerations for States as They Select Appropriate Risk Levels, provides guidance on whether a state’s existing criteria are as protective as EPA’s criteria. This threshold of ‘as protective as’ EPA’s criteria was used to determine what states would be included in the November 2004 promulgation, but also could be critical in the future as other states seek EPA approval of their water quality standards. EPA considered states that used an illness rate of 1.0% or less for fresh waters (i.e., 10 illnesses per 1,000 swimmers) to have criteria as protective of human health as the 1986 criteria, and therefore, did not promulgate criteria for these states. The fact sheet provides additional information on how the Agency established its risk levels for fresh and marine waters and what flexibility states have in setting risk levels.

Fact Sheet – Using Single Sample Maximum Values in State Water Quality Standards
The second fact sheet, Using Single Sample Maximum Values in State Water Quality Standards, explains EPA’s current position on using the single sample maximum (SSM) specifically in BEACH Act waters, but could provide general guidance for the use of the SSM value from the 1986 criteria in other states. The issue of the SSM was the focus of NACWA’s comments on EPA’s proposal to promulgate bacteria criteria for certain coastal waters. NACWA’s primary concern was that the SSM value would be used for making regulatory compliance decisions. This fact sheet clarifies that the geometric mean value, not the SSM, is the more relevant value for ensuring that appropriate actions are taken to protect and improve water quality. The fact sheet further notes, among other things, that:

• The SSM is best used for making beach notification and closure decisions;

• SSM values were not developed as acute criteria;

• There are instances where the concentration of bacteria in one or more individual samples will be higher than the acceptable geometric mean concentration; exceedance of the geometric mean value, or even the SSM value, by one or more individual samples, does not necessarily indicate that the criterion has actually been exceeded; and

• It would not be appropriate for a state to use the SSM as a substitute for the geometric mean if there is more than one measurement (sample).

Next Steps
NACWA will keep the membership informed of its efforts to intervene in the pending litigation over EPA’s failure to meet all of the requirements in the BEACH Act and any efforts to develop new criteria. NACWA is also planning to nominate members to participate in an upcoming expert’s workshop on EPA’s development of a science plan for new recreation water quality criteria, an effort that appears to have been accelerated due to the NRDC lawsuit.