EPA is responding to soils contaminated with the pesticide toxaphene, resulting from the disposal activities of a pesticide aerial applicator who ceased operations over 20 years ago. The Site is on lands of the Gila River Indian Community (GRIC). Extensive planning with the Tribe over the past year has resulted in this removal action. Toxaphene concentrations over portions of this 17 acre site pose human health and environmental threats.
Bench-scale and pilot-scale studies over the past yearr have confirmed the effectiveness of anaerobic bioremediation in treating his contamination to levels below concern.
Personnel and equipment were mobilized to the Site on April 14, 2004. Excavation of soils commenced and soils were stockpiled for treatment. As of April 18th, approximately 3,045 cubic yards have been excavated and stockpiled.
Meetings were held with Tribal environmental personnel to review operations. Dust control has been effective. No problems have been encountered tus far.
Excavation of soils will continue during the week of April 19th. Then the treatment cells will be prepared. The contaminated soils will be mixed with treatment amendments and water, and loaded into the lined cells. Areas where contaminated soils were removed will be back-filled with clean soil.
This removal is on the Gila River Indian Community so close coordination with the Tribe is very important.