Perchlorate (ClO 4 -
) contamination of ground and surface waters has placed drinking water supplies at risk in communities throughout the US, especially in the West. Several major assessment studies of that risk in terms of health and environmental impact are expected to be released by the US Environmental Protection Agency in early 1999, and preparations for how best to manage and minimize that risk are underway. Perchlorate salts are used in rocket and missile propulsion; therefore, it is believed that the pollution is derived primarily from defense and supporting industry. Due to the perchlorate anion's fundamental physical and chemical nature, the contamination is difficult to treat or remediate. The current work describes the evolution of the unique team-based governmental response to the problem and the rapidity of its development. Technologies under consideration that may prove feasible for treating contaminated water supplies are discussed and evaluated. The impact of these treatment technologies on other regulatory compliance matters and limitations of space, cost, and other resources are considered. Practical guidelines for approaching the problem are outlined, and current research needs are identified.