EPA receives six-month extension to finalize its regulation for perchlorate in drinking water

October 8, 2019

The U.S. Environmental Protection Agency received a six-month extension for finalizing the rule of regulating perchlorate in drinking water. The deadline is now June 19, 2020 to finalize the rule.

The EPA is proposing to set both the enforceable maximum contaminant level (MCL) for the perchlorate regulation and the perchlorate maximum contaminant level goal (MCLG) at 0.056 mg/L (56 µg/L). The EPA is proposing requirements for water systems to conduct monitoring and reporting for perchlorate and to provide information about perchlorate to their consumers through public notification and consumer confidence reports.

The proposal includes requirements for primacy agencies that implement the public water system supervision program under the Safe Drinking Water Act. It also includes a list of treatment technologies that would enable water systems to comply with the MCL, including affordable compliance technologies for small systems serving 10,000 persons or less.

The Natural Resources Defense Council brought a lawsuit against the EPA in 2016 to require the EPA to regulate perchlorate.

Perchlorate is a naturally occurring and manufactured chemical that is commonly used as an oxidizer in rocket propellants, munitions, fireworks, airbag initiators for vehicles, matches, and signal flares. It dissolves easily in water and a known groundwater contaminant. Perchlorate can disrupt the normal function of the thyroid gland in both children and adults.