US EPA recently agreed in federal court to engage in a rulemaking process over the next three-plus years which would culminate in the promulgation of final perchlorate regulations by December 19, 2019. Perchlorate remains the only unregulated contaminant for which US EPA has made a final determination to regulate since the Safe Drinking Water Act (SDWA) was amended in 1996.

Perchlorate is a highly soluble chemical in water and can move quickly from soil contamination into groundwater. It has been used by the US Department of Defense as an oxidizer in munitions and missiles since the 1940s, and 90 percent of its manufacturing is for the defense and aerospace industries.  In a February 2011 declaration, US EPA determined that it should regulate perchlorate in drinking water—giving itself 24 months from that date to propose regulations and another 18 months thereafter to finalize them under the SDWA. However, due in part to the Scientific Advisory Board’s rejection of the model US EPA submitted for perchlorate regulation, these self-imposed deadlines were missed. As a result of the delay, the Natural Resources Defense Council (NRDC) filed a complaint in the US District Court for the Southern District of New York against US EPA in February 2016 to enforce the deadline for proposed perchlorate regulations for public comment.

In the NRDC case, the Agency acknowledged that it failed its legal obligations to propose and promulgate a maximum contaminant level (MCL) and maximum contaminant level goal (MCLG) as a national primary drinking water standard for perchlorate. US EPA’s agreement to promulgate perchlorate regulations by the end of 2019 is embodied in a proposed settlement agreement. Under the proposed agreement, US EPA will: (1) complete an “external peer review process” by October 18, 2017; (2) propose limits by October 31, 2018; and (3) finalize a rule by December 19, 2019.  Given the amount of delay that has already occurred in promulgating federal regulations, it is somewhat surprising that NRDC accepted the length of the proposed schedule. Indeed, despite the pending settlement agreement, NRDC counsel filed its motion for summary judgment on October 12, 2016 and requested that the judge enter an order cementing US EPA’s liability and scheduling reasonable timelines for US EPA compliance.

It is noteworthy that, in likely response to national attention paid to the Flint Michigan crisis, two US House of Representatives Resolutions (H.R. 6116 and H.R. 6140) were introduced on September 22, 2016 that, if passed, would require the US EPA Administrator to publish an MCLG and promulgate a national primary drinking water regulation for perchlorate no later than 12 months following the law’s date of enactment. This proposed legislation amending the federal SDWA has the potential to expedite the rulemaking process outlined in the settlement agreement reached between US EPA and NRDC. Notably, while future federal perchlorate regulations will formally apply to the quality of drinking water measured at the tap in a home or business, the ultimate standard promulgated by US EPA bears watching by companies who are undertaking groundwater remediation associated with industrial activities, for example, as an applicable or relevant and appropriate requirement (ARAR) under CERCLA.