The Stringfellow site is an inactive hazardous waste disposal facility in Riverside County, California, approximately 50 miles east of Los Angeles. The site is divided into four zones. From 1956 to 1972, approximately 34 million gallons of industrial waste from metal finishing, electroplating, and DDT production were disposed of in unlined evaporation ponds located throughout Zone 1. Some of the wastes from these ponds migrated into the ground water system. In 1980, EPA removed approximately 10 million gallons of contaminated water, reinforced containment barriers, and improved a truck loading area. Further removal actions included installing french drain system fences; removal of all remaining surface liquids; partially neutralizing and capping the wastes; installing a gravel drain network, monitoring wells, and surface channels; and contructing a surface barrier and leachate collection system downgradient from the original evaporation ponds. In 1983, the first Record of Decision (ROD) provided an interim remedial measure and addressed additional fencing of the site and implemented erosion control and offsite disposal of the extracted leachate. The fourth ROD addresses the contaminated ground water in Zone 1 and in Zone 4, and proposes treatability studies to remediate the source material in Zone 1.