Number: RS21961
Title: Perchlorate Contamination of Drinking Water: Regulatory Issues and Legislative Actions
Authors: Mary Tiemann, Resources, Science, and Industry Division 
Abstract: Members of Congress have urged the Environmental Protection Agency (EPA) to set a federal drinking water standard for this chemical. Regulatory issues involve the relative health benefits and costs of federal regulation, including environmental cleanup and water treatment costs, both of which are driven by federal and state standards. (California and Massachusetts have set standards.) EPA has spent years assessing perchlorate's health effects and occurrence (including its occurrence in food) to determine whether a national standard is warranted. Interagency disagreements over the risks of perchlorate exposure led several federal agencies to ask the National Research Council (NRC) to evaluate perchlorate's health effects and EPA's risk analyses. In 2005, the NRC issued its report, and EPA adopted the NRC's recommended reference dose (i.e., the expected safe dose) for perchlorate exposure. Subsequent studies raised more concerns about potential effects of low-level exposures, particularly for infants in certain cases. In October 2008, EPA announced its preliminary determination not to regulate perchlorate in drinking water.
Pages: 6
Date: November 24, 2008