EPA announced the release of a notice of proposed rulemaking for regulating perchlorate in drinking water May 23. The proposal was published in the Federal Register on June 26. The proposed rule sets both a Maximum Contaminant Level (MCL) and a Maximum Contaminant Level Goal (MCLG) of 56 parts per billion (ppb), but is also seeking public input on three alternative regulatory options:
- An MCL and MCLG set at 18 ppb.
- An MCL and MCLG set at 90 ppb.
- Withdrawal of the agency’s 2011 determination to regulate perchlorate in drinking water.
The agency is seeking comment on “all relevant aspects of the proposed rule but is especially interested in the perchlorate monitoring and reporting requirements for public water systems and a list of treatment technologies that would enable water systems to comply with the MCL.” Comments are also sought on the agency’s methodology for deriving the MCLG, and the underlying assumptions and analysis of its cost and benefit estimates. A nine-page summary of the proposal can be found on AMWA’s website.
The public has until August 26 to provide comments. EPA has been mandated by consent decree to propose an MCL for perchlorate by May 28, 2019. The agency now has until December 19, 2019 to finalize a rule. AMWA is developing comments in consultation with the regulatory committee. If you have any questions or would like to provide comments for AMWA's letter, please reach out to Stephanie Hayes Schlea by Friday, August 2.