By KATHERINE PETERSEN
The U.S. Navy is testing a new way to detoxify contaminated water from Moffett Federal Airfield and nearby Silicon Valley computer chip makers.
A wall of iron filings 25 feet high and six feet thick has been installed at Moffett Field. As groundwater passes through this "iron curtain," which was put in place last month, contaminants in the water chemically react with the iron to create inert particles, said Stephen Chao, environmental project manager for the Navy, which is responsible for Moffett's cleanup effort.
"The water comes out the other side a lot cleaner," Chao said, adding that the new technology will help the Navy save money.
The solvents used to clean airplane engines and other hazardous materials are not just separated from the water and then disposed of, but are neutralized using this new process.
'We won't have pumps or piping to maintain," he said.
The cost of the pilot study is $300,000. If the Navy were to institute a full-scale program, it could save upward of $5 million over 30 years.
Chao said the required thickness of the wall depends on the amount of solvents in the water.
"Only five iron curtains are in place in the world. The other one in Silicon Valley is at Intercil in Sunnyvale," Chao said. Intercil's curtain was put in place in November 1994.
There are 190 other Navy sites with similar contamination problems that could benefit from this technology.
After detoxification, the water moves toward the bay to storm water retention ponds, Chao said. If the water is not cleaned, it could migrate away from Moffett and pollute other areas.
Cleaning up water at Moffett, home to several Superfund sites, was of concern to the Navy, the Environmental Protection Agency and the surrounding communities.
Paul Lesti, former community co-chairman of the Moffett Field Restoration Advisory Board, said the Navy came to the advisory board for community input on the pros and cons of the proposed "iron curtain."
Lesti said anyone can attend the advisory board meetings, which take place every second Thursday of the month at the Mountain View Police and Fire Administration Building auditorium at 7 p.m.
This article appeared in the Sunnyvale Sun, May 8, 1996.
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