On February 2, Administrator Lisa Jackson announced in a press release and in her testimony to the Senate Environment and Public Works Committee that the agency will move forward to develop a regulation for perchlorate in drinking water.
On February 11, EPA’s official regulatory determination for perchlorate was published in theFederal Register (76 FR 7762). A link to the FR site as well as the perchlorate docket and additional information is available.
EPA is evaluating the alternative health reference levels (HRLs) previously presented in its August 9, 2009 FR (74 FR 41883) notice and considers the HRLs to be “levels of public health concern for purposes of this determination.” EPA derived potential alternative HRLs for 14 different age groups using the reference dose (RfD) of 0.7 μg/kg/day recommended by the National Research Council in 2005. The alternative HRLs derived by EPA range from 1 μg/L to 47 μg/L and “are the concentrations of perchlorate in drinking water that may result in total perchlorate exposures (from food and water) greater than the RfD for individuals at each life stage (age group).”
EPA identifies the ability of perchlorate to interfere with the normal functioning of the thyroid gland as the adverse health effect. The FR notice notes that the “thyroid hormones play an important role in the regulation of metabolic processes throughout the body and are also critical to developing fetuses and infants, especially with respect to brain development.”
EPA’s regulatory process for perchlorate will include seeking input from key stakeholders as well as consulting with the National Drinking Water Advisory Council, Science Advisory Board and the Secretary of Health and Human Services. EPA will propose the perchlorate standard by early 2013. This will be the first contaminant that EPA is regulating under the regulatory process outlined in the 1996 Safe Drinking Water Act amendments.