In 1987, Sangamo conducted soil and groundwater studies on and around the plant site. Based on these investigations, a remedy was selected to clean up the site in 1990. Remedy design began in 1993. Soil treatment design was completed in 1993. The excavated material is to be transported to the Sangamo plant site for staging and treatment.
Treatment includes thermal desorption and carbon adsorption.
Treated soil is to be stored at the plant site. By early 1994, Sangamo Weston had completed a portion of the cleanup scheduled for completion in 1996. This cleanup included removal of 17,711 cubic yards of contaminated soils and waste from the six former dumpsites and then stockpiling it in a controlled fashion at the Sangamo Weston plant site. The former dumpsites were then returned to their original condition. In 1996, a geotextile liner and soil cap were installed at the Breazeale site to retard the migration of PCB contamination.