EPA has proposed a rule that would require public water utilities to monitor tap water for 28 substances, including nine volatile organic compounds (VOCs), seven hormones, four metals, an oxyhalide chlorate, the solvent 1,4-dioxane, six perfluorinated alkyl acids, and two categories of microbe. 76 Fed. Reg. 11,713 (3/3/11). EPA will accept comments on the proposed rule until May 2, 2011.

Section 1445(a)(2) of the Safe Drinking Water Act (SDWA) requires the agency to issue a new unregulated contaminant monitoring rule every five years. The rule can specify as many as 30 contaminants for monitoring, selected from a candidate list maintained by EPA. The proposed rule identifies six EPA-developed analytical methods and four other methods that can be used to assess the selected contaminants. The agency is also soliciting specific comments on its proposal to require utilities that purchase water to monitor as well. Prior monitoring rules applied only to utilities that treated drinking water.