The U.S. Environmental Protection Agency (EPA) and Shell Oil Co. have removed more than 23,000 lb of hazardous toxins from the Del Amo Superfund site waste pits near Torrance, Calif.
With EPA oversight, responsible parties Shell Oil Co. and the U.S. General Services Administration built a soil vapor extraction system at the Del Amo Waste Pits and have been successfully operating it for one year. The system stops further contamination of area groundwater, a potential drinking water resource.
"A common challenge for a project of this nature is how to extract harmful toxins in a safe and effective manner," said Keith Takata, superfund division director for the EPA's Pacific Southwest region. "EPA worked with its partners to select an approach that utilizes natural bacteria in the ground to destroy the contamination. This is an excellent example of how the EPA collaborates with local and state agencies, and community groups to achieve a common goal of protecting human health and the environment."
The site's soil treatment system uses a vacuum to extract vapors from the ground. The majority of the extracted vapors are re-injected underground with the addition of oxygen, enabling natural bacteria underground to flourish and consume the contamination. The remaining extracted vapors are sent through a carbon filtration system and cleansed before being discharged into the area. To date, the treatment system has removed more than 23,000 lb of contaminants.
Throughout the cleanup, the EPA has worked closely with California's Department of Toxic Substances Control to protect area residents. During the early process of identifying and evaluating the best vapor treatment options, EPA officials collaborated with many public interest groups including: the Del Amo Action Committee; California Communities Against Toxics; the Sierra Club; the Los Angeles County Health Department; and the South Coast Air Quality Management District.
The EPA will continue to oversee cleanup efforts at the waste pits area. The efforts are expected to take approximately 10 to 15 years.
