The soil — excavated from other areas of Moffett — are contaminated with polychlorinated biphenyls (PCBs), zinc, lead, chromium, cadmium, and dichlorodiphenyltrichloroethane (DDT). According to the Environmental Protection Agency, erosion of the soil mounds into the adjacent ponds poses a threat to wildlife, including the endangered salt marsh harvest mouse.
NASA officials say a silt fence around the mounds — typically made of plastic — may have to do for over a year until a "permanent remedy" can be developed.
The nearby pond, known as site 25, was subjected last year to a $9.7 million toxic cleanup by the United States Navy, which handed over Moffett Field to NASA Ames Research Center in 1994.
According the EPA, one source of contamination from the ponds was rainwater runoff from Hangar One, which recently underwent its own toxic cleanup of PCBs, asbestos and lead, also by the Navy. The Navy is still responsible for much of a widespread toxics cleanup effort at Moffett, which includes miles of petroleum lines and tanks that leaked and a massive groundwater plume of the carcinogenic solvent trichloroethylene (TCE).
EPA spokesperson David Yogi said NASA has been cooperative with its portion of the ongoing toxics cleanup at Moffett, but a long-term Federal Facilities Agreement has yet to be negotiated. "NASA is on board" with efforts to get a long-term agreement in place, Yogi said. The California State Regional Water Quality Control Board is also regulating cleanup work at Moffett.
"We wanted to make sure we highlight this as a priority for immediate action," Yogi said. "We have the Navy that's already done work that's close to this site."
NASA Ames deputy director Deb Feng issued a statement about the situation.
"In response to the order — as an interim measure — NASA will install a silt fence barrier this summer around the fill area to prevent contaminated sediments being released to Site 25," Feng said. "NASA will develop a permanent remedy for the fill area to replace the temporary silt fence barrier and expects to complete the project by the summer of 2014. NASA is still assessing the effects that budget sequestration might have on the cleanup project."
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