"Our goal is to protect the people living and working in this community from the harmful effects of vapor intrusion," said Jared Blumenfeld, EPA's Regional Administrator for the Pacific Southwest. "This settlement requires the final cleanup of the groundwater, eliminating the potential for contaminants to enter homes and buildings."
From 1970 to 1985, CTS Printex manufactured circuit boards at a site bordered by Colony Avenue to the north and Sierra Vista Avenue to east, using solvents that contaminated the soil and groundwater. Townhouses were built on the site a few years ago, and indoor air samples taken after construction found no TCE vapors. TCE vapor intrusion through the soil and floors can cause cancer and birth defects, among other problems, according to the EPA.
EPA officials told the Voice that there will be no more clean-up work under the homes.
"Contaminants there (under the homes) are at very low levels — either at or very close to the cleanup standards," wrote EPA spokesman David Yogi in an email. "EPA will continue to monitor the groundwater levels beneath the townhomes to ensure contaminant levels are decreasing."
Yogi said the site could be cleaned up to EPA standards within 10 years. Until then, groundwater use is restricted and building plans must be cleared with the EPA.
EPA's chosen cleanup method for the site is "bioremediation" which involves injecting a substrate into the ground for TCE-eating bacteria, likely to be used on a concentrated area of contamination in a parking lot among commercial buildings just north of the original site. There will also be "monitored natural attenuation" — which means making sure the remaining levels of TCE naturally break down.
CTS Printex employed about 400 people at the Mountain View plant and decided to move to Fremont when it couldn't comply with Mountain View's ordinance for hazardous materials storage and disposal, recalled Lenny Siegel, director of the Center for Public Environmental Oversight. Fremont residents protested the company's move there, he added.
The site is one of 23 in the county the EPA is working to clean up, most of them contaminated with TCE.
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