EPA begins on-site cleanup of AMCO Chemical Superfund Site

Oakland resident Queen Thurston was one of the first to show up at this weekend’s community event to celebrate the installation and start-up of a new groundwater and soil treatment system at the AMCO Chemical Superfund Site, located one block south of the West Oakland BART station.

In the 1990s, Thurston was among a group of protesters who staged rallies calling for an investigation into the environmental condition of the area. For about 20 years—until the late 1980s when AMCO Chemical stopped its operation—the company had been off-loading bulk chemicals from a rail spur at that site and storing them in tanks, raising residents’ concerns about toxic chemicals and a strong odor. The community members alleged that the site had harmed their property values, and claimed it had caused everything from breathing problems to cancer and miscarriage—although no analysis by experts ever concluded that the site had caused such severe health effects.

“I’m happy they are cleaning up now, although I don’t know what took them so long,” Thurston said.

The United States Environmental Protection Agency (EPA) has been supervising the site for many years and trying to work out a remediation strategy. The EPA has negotiated with residents about whether to dig out the contaminated soil and ship it offsite, or resort to a cheaper plan, treating the chemicals on-site.

The EPA became involved in 1996, after investigators from PG&E and the California Department of Transportation inspected the site following utility workers’ complaints about chemical odors and found chlorinated solvents, which are human carcinogens, on or near the site. The state concluded they did not pose an immediate threat to residents, but “may pose a potential threat if nothing is done,” according to the EPA’s online report about the site. The state’s Department of Toxic Substances Control requested help from the EPA that year.

In 2003, the AMCO site was added to the National Priorities List (NPL), which identifies hazardous waste sites in the United States eligible for long-term remedial action (cleanup) financed under the federal Superfund program.

The cleanup has been funded with taxpayers’ money, drawn from the federal budget, because AMCO Chemical declared bankruptcy.

“AMCO was gone. Nobody left. But this is not uncommon with contaminated sites, when former owners abandon them” said Kelly Manheimer, the EPA’s project manager for the AMCO site.

Two partial cleanups have already been performed at the site, removing some of the volatile organic compounds and lead detected in soil and groundwater. But the treatment system was turned off in 1998 after members of the community raised concerns about contaminants coming from the system’s exhaust stack. A more advanced cleanup system had to be designed. It took the EPA almost a year to construct, and it will cost the federal budget about $10 million.

In the course of the treatment, 69 electrodes placed underground throughout the site will heat the soil and groundwater to vaporize and capture con­taminants, such as trichloroethylene (TCE) and vinyl chloride, both types of volatile organic compounds classified by the EPA as human carcinogens.

“It is like an old-fashioned coil heater that you used to boil water with,” Manheimer said.

In the next stage, the chemicals will get sucked into a pipe that will work like “a vacuum cleaner, pulling contaminants in and preventing them from spreading,” said Manheimer. Then they will run through a treatment system and be disposed of offsite.

But even this modern technology will not remove all the chemicals. In about six to eight months, after the procedure is finished, the EPA will test the soil and groundwater, evaluate the remediation results, and start discussing with the local community how to develop the site further, according to Manheimer.

“It is hard to put up with something harmful being there underground, close to your home,” Thurston said at Saturday’s event. “It is a relief to know it is going to be gone for good.”