Safe Drinking Water Act: Improvements in Implementation Are Needed to Better Assure the Public of Safe Drinking Water

This testimony discusses highlights of GAO's report on the Environmental Protection Agency's (EPA) implementation of requirements for determining whether additional drinking water contaminants warrant regulation. The number of potential drinking water contaminants is vast--as many as tens of thousands of chemicals may be used across the country, and EPA has identified more than 6,000 chemicals that it considers to be the most likely source of human or environmental exposure. The potential health effects of exposure to most of these chemicals, and the extent of their occurrence in drinking water, are unknown. Under 1996 amendments to the Safe Drinking Water Act, every 5 years EPA is to determine for at least five contaminants whether regulation is warranted, considering those that present the greatest public health concern. EPA issued final regulatory determinations in 2003 and 2008 on a total of 20 contaminants, deciding in each case not to regulate. EPA did not recommend any new contaminants for regulation until February 2011, when it reversed its controversial 2008 preliminary decision to not regulate perchlorate, an ingredient in rocket fuel and other products. This statement summarizes our report being released today that (1) evaluates the extent to which EPA's implementation of the 1996 amendments has helped assure the public of safe drinking water and (2) reviews the process and scientific analyses EPA used to develop the 2008 preliminary decision to not regulate perchlorate..