AWWA JAW36082

The US Environmental Protection Agency (US EPA) has been attempting for several years to set a maximum contaminant level (MCL) for radon in drinking water. On July 18, 1991, US EPA proposed National Primary Drinking Water Regulations for six radionuclides, including radon. Most of the more than 600 sets of public comments submitted in response to this proposal focused on radon. US EPA's proposed MCL of 300 pCi/L for radon in drinking water has received severe criticism. There is widespread agreement among state health and radiation protection agencies, the scientific community, water suppliers, and other federal government agencies that the US EPA has overestimated the incremental benefits associated with the proposed MCL, while it has underestimated the cost of compliance. Following the close of the public comment period in November 1992, US EPA began to evaluate the proposal and prepare a response to the comments in order to develop a final rule. Concern remains regarding the rationality of the proposed MCL for radon. At the time of proposal, USEPA was under a court order to publish the final radionuclides rule no later than April 1993. This article focuses on developments and chronological history since the proposed rule was published. Includes 25 references, tables.