Savannah River Site workers have toiled for years to strip millions of pounds of hazardous solvents from ground water at the federal nuclear weapons site. Now SRS officials say they have reached a milestone in cleanup of one of the site's worst plumes of contamination.
As of this month, SRS workers have treated more than 4 billion gallons of contaminated ground water in the 5.5-square-mile plume, which is located less than a half-mile from the site's northwest boundary in its "A" and "M" areas.
Although the water cannot be returned to a pure state and will require many more years of treatment just to reach regulatory standards, SRS officials said this week that the 4 billion gallon mark was notable.
"We've made a substantial dent in the solvent inventory of the subsurface," said Christopher Bergren, who manages the cleanup project for SRS contractor Bechtel Savannah River Inc.
"We know we're not going to be able to walk away from here and say that it's pristine," Mr. Bergren said. "There just aren't enough technologies at our disposal. We're still several years away from determining what the final cleanup standards are going to be."
A local observer said cleanup of the plume is crucial, but that the site shouldn't call the 4 billion mark a "milestone."
"Containing this pollution on government property is clearly a critical mission for SRS, and one that we greatly encourage," said Don Moniak, an Aiken resident and community organizer for Blue Ridge Environmental Defense League. "But SRS shouldn't be trumpeting the accomplishment of pumping and treating 4 billion gallons of water unless they can also say with confidence that the situation is improving.
"Public relations and science don't mix well."
The cleanup project has removed about 1 million pounds of the plume's originally estimated 3.5 million pounds of tetrachloroethylene and trichloroethylene, Mr. Bergren said.
If inhaled or ingested in large amounts, trichloroethylene can harm the nervous system, liver, and lungs and even cause death. Exposure to high levels of tetrachloroethylene also can be lethal, and the chemical is suspected to be the cause of menstrual problems and spontaneous abortion in women.
From the 1950s through the early 1970s, SRS workers often dumped the solvents into open air, earthen basins in A and M areas, believing that the compounds would evaporate harmlessly into the atmosphere.
Instead, the chemicals seeped into the earth, polluting the soil and ground water below. The site's cleanup effort is intended to contain and treat the plume to prevent it from contaminating more soil and ground water, or reaching streams, from which the chemicals could flow off-site.
The cleanup effort, which began in 1985, costs about $2.5 million per year, Mr. Bergren said.
Reach Brandon Haddock at (706) 823-3409.