Following extensive review and analysis of the best available science, the U.S. Environmental Protection Agency (EPA) published a final action on July 21, 2020. In it, EPA determined that perchlorate does not occur “with a frequency and at levels of public health concern” within the meaning of the SDWA. In addition, in the judgment of the EPA administrator, regulation of perchlorate does not present a “meaningful opportunity for health risk reduction for persons served by public water systems.” Accordingly, EPA is withdrawing its 2011 determination and is making a final determination not to regulate perchlorate, and therefore will not issue a NPDWR for perchlorate at this time.
Two states have promulgated regulations for perchlorate, California (6 ug/L) and Massachusetts (2 ug/L). Several other states have issued advisory levels for perchlorate as summarized by EPA. The Agency has also documented the progress made in decreasing perchlorate levels.