AWWA ACE58305

Since the discovery of perchlorate contamination in a number of California groundwaters in 1997, it has been detected in many other locations across the country. The United States Environmental Protection Agency (USEPA) estimates that groundwaters in 40 states have the potential to be contaminated with perchlorate, and actual drinking water contamination with this chemical has been documented in approximately half of them. Perchlorate (ClO4 -) appears to be linked to the historical manufacturing, usage, or processing of ammonium perchlorate (NH4ClO4), a solid rocket fuel. In March 1998, the USEPA formally added perchlorate to the drinking water contaminant candidate list (CCL). Its monitoring in drinking water supplies was mandated in 1999 under the Unregulated Contaminants Monitoring Rule (UCMR). The primary concerns over perchlorate toxicity include its known adverse effect on the thyroid gland, as well as possible carcinogenic, developmental, reproductive, and immunotoxic effects. As a collaborative effort between MWH and the University of Houston, the two primary objectives of this on-going research are to: demonstrate the long-term performance of conventional ion-exchange technology for perchlorate removal; and, evaluate three disparate alternatives (chemical, biological, electrolytic) for brine treatment and reuse. While addressing these objectives, the underlying requirement of the pilot-scale system is to ensure that the treated water perchlorate concentration remains below the recently lowered California Department of Public Health Services perchlorate Advisory Action Level of 4 ug/L. Includes tables, figures.