On January 4, EPA rang in the new year with the release of its “Final Regulatory Determinations for Contaminants on the Third Drinking Water Contaminant Candidate List.” Regulatory determinations are required to be made under the Safe Drinking Water Act every five years, and the current group of contaminants considered are from EPA’s third Drinking Water Contaminant Candidate List (CCL3). Four contaminants from CCL3 – dimethoate, 1,3-dinitrobenzene, terbufos and terbufos sulfone – received a negative regulatory determination because they do not occur with sufficient frequency (if at all) in drinking water. However, the contaminant being watched closest by the drinking water community, strontium, did not receive a determination at this time.
The final regulatory determination for strontium, which received a preliminary positive determination in October 2015, is being delayed to allow further study. According to an Office of Water newsletter, EPA “based its decision to delay a final determination for strontium on public comments received and plans to further evaluate scientific information that became available after publication of the preliminary regulatory determinations. By delaying action, the agency can use the best available science to conduct additional scientific analyses to determine if there is a need to develop a national drinking water regulation for strontium.” A specific schedule and process for the further evaluation of strontium is not yet available.
Additional information on the EPA’s final regulatory determinations, including links to the Federal Register notice, is available through EPA’s Contaminant Candidate List (CCL) and Regulatory Determination webpage.