EPA Signs Federal Advisory Committee Agreement - The U.S. Environmental Protection Agency (EPA) and a diverse group of stakeholders signed the Stage 2 Microbial and Disinfection Byproducts Federal Advisory Committee Agreement in Principle in September 2000. The agreement will effectively lower exposure to disinfection byproducts while still protecting consumers from bacteria, viruses and other disease-causing organisms in water. The Advisory Committee consisted of representatives of the EPA, the Chlorine Chemistry Council, other chemical and equipment manufacturers, public interest groups, public health and regulatory agencies, local officials, Indian tribes and drinking water suppliers. The agreement was issued to the public via the Federal Register on December 29, 2000.

Background - The agreement was prompted by 1996 amendments to the Safe Drinking Water Act, which required the EPA to promulgate a Stage 2 Disinfection Byproducts Rule by May 2002. The agreement addresses drinking water regulations focusing on risks from microbial pathogens and disinfection byproducts (DBPs). The Stage 2 rule is being developed simultaneously with the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR ) in order to address the risk trade-offs between pathogen control and exposure to DBPs. The EPA will propose these two rules later in 2001 based on the recommendations in the agreement. The revised standards reflect new data collected from 300 large public water systems and 120 surveys of small systems.

Impact on Disinfection - The Stage 2 MCLs Maximum Contaminant Level (MCL) will remain 80 parts per billion (ppb) for trihalomethanes (THMs) and 60 ppb for haloacetic acids (HAAs). The stage 2 DBP rule will NOT reduce the MCLs for THMs to 40 ppb and HAAs to 30 ppb as previously proposed. We anticipate that chlorine-based products - the only disinfectants that maintain water quality all the way to the tap - will remain the disinfectant of choice.

Implementation - The rule will be implemented in two phases. During Phase 1 of the implementation, the MCLs for THMs and HAAs will be 80 ppb and 60 ppb respectively (based on each utility's system-wide running annual averages). Additionally, locational running annual averages (sample site-specific) of 120 ppb and 100 ppb will be introduced. During Phase 2, compliance sites will be changed based on the sites determined by a system wide study of disinfection byproduct levels. In addition, the maximum levels for the more stringent locational running annual averages will be reduced to 80 ppb for THMs and 60 ppb for the HAAs.

Timeline of significant developments:

2002 EPA will promulgate the Stage 2 Disinfectants and Disinfection Byproducts Rule.

2005 All systems that do not require capital improvements must comply with Phase 1 requirements.

2007 Systems that required capital improvements must comply with Phase 1.

2008 All large (greater than 10,000) and medium (500 - 9,999) systems not requiring capital improvements must comply with Stage 2 requirements.

2010 Small systems (less than 500) that do not require capital improvements must comply with Phase 2. Medium and large systems that required capital improvements must comply with Phase 2.

2012 Small systems that required capital improvements must comply with Phase 2.

For More Information - Visit the Federal Register of Environmental Documents.