Perchlorate Contamination of Drinking Water: Regulatory Issues and Legislative Actions
Publication Date: November 2008
Publisher(s): Library of Congress. Congressional Research Service
Perchlorate is the explosive component of solid rocket fuel, fireworks, road flares, and other products. Used mainly by the Department of Defense (DoD) and related industries, perchlorate also occurs naturally and is present in organic nitrate fertilizer from Chile. This very soluble, persistent compound has been disposed of in the ground for decades and has been detected in sources of drinking water for more than 11 million people. It also has been found in milk, fruits, grains and vegetables. Thus, concern has increased about the potential health risks from perchlorate exposure. The Environmental Protection Agency's (EPA's) effort to make a determination whether to regulate perchlorate in drinking water has been slowed by uncertainties regarding the health effects of exposure at low levels and by the need for further research on occurrence and treatment technologies. Related issues include environmental cleanup and water treatment costs, which will be driven by federal and state standards. Because of scientific uncertainties and interagency disagreement regarding the risks of perchlorate exposure, several federal agencies asked the National Research Council (NRC) to assess perchlorate's health effects and the EPA's draft risk assessment. The NRC issued its report in January 2005, and the EPA has adopted the NRC's recommended reference dose (i.e., the expected safe dose) for perchlorate exposure. The reference dose provides a basis for developing a standard; however, the EPA has not decided to regulate perchlorate, and new studies raise more questions about what level of exposure might be safe. This report reviews perchlorate water contamination issues and related actions.