Silicon Valley: a case study in cross-media management - cross-media pollution

Science News, Feb 23, 1985 by Christine Mlot

California's Silicon Valley may be a model of both the way cross-media problems develop and a means for managing them.

The once-agricultural Santa Clara County, now better known for the semiconductor silicon, is shedding the clean image long associated with its microelectronics industry, as workplace and environmental health risks surface. The reputation grew out of the seemingly sterile conditions for manufacturing integrated circuit chips, the base of the valley's $19 billion industry. Chipmakers in "clean rooms" wear white suits and masks to keep dust off the silicon chip surfaces; the factories themselves are low, smokestackless buildings. But the surrounding landscaped lawns cover underground tanks storing toxic organic solvents used in cleaning the chips as the circuitry is developed on them. And since 1981 a series of tank and pipe leaks contaminating groundwater and soil have been discovered.

One of the first and largest detected leaks, from the Farichild Camera and Instrument Corp. in San Jose, Calif., contaminated a public drinking well with 1,700 to 8,800 parts per billion of the solvent trichloroethane (TCA). (The state standard for TCA is 200 parts per billion.) Last mont the California Department of Health Services released a report of pregnancy outcomes around the time of the leak. The neighborhood serviced by the well experienced three times as many birth defects and twice as many miscarriages as a control neighborhood with uncontaminated water. But the report concluded that without details about specific exposures to the contaminated water, the leak cannot be definitely blamed as the cause, nor can it be ruled out.

To date, about 100 other chemical leaks in the valley have sunk into upper groundwater supplies, closing 38 private and four public wells.

When EPA proposed its 1984 update of new "Superfund" sites needing cleanup, 19 Silicon Valley firms were included because of their common groundwater contamination problem. Most of these firms ranked in the lower half of the 244 new sites, well below the most hazardous smelters and chemical dumps, but an Superfund rankiung designates a site "that appears to present a significant risk to public health or the environment," according to an EPA notice. The sites are to be finally approved by summer 1985 for eventual Superfund cleanup.

Two Santa Clara County firms, IBM and Fairchild, have been pumping 16 million gallons per day of chlorinated solvent-contaminated groundwater, according to an EPA report, and channeling the water to San Francisco Bay after carbon treatment or aeration. The practice has local regulatory approval, but others consider such groundwater aeration to be an example of cross-media transfer of pollutants.

"You're taking the problem from the water and putting it in the air," says Yoram Cohen, a chemical engineering professor at UCLA's National Center for Intermedia Trasport Research. And though chlorinated solvents will eventually break down in sunlight, "the chlorine remains to react form other chlorinated compounds. I don't think it's a solution," he says.

A new way to manage cross-media pollutants, including the diaphanous problem of hazardous organics in the air, is under trial in Silicon Valley. A special $1 million EPA program, the Integrated Environmental Management Project, is designed to take a ringmaster approach to consider contamination problems in all environmental phases at once. The project has chosen 54 toxic chemicals circulating in the valley and is comparing their health risks in all phases.

Ted Smith, head of the Silicon Valley Toxics Coalition, a community watchdog group in San Jose, Calif., calls the project a "nice idea" but questions what its numerical analysis will actually accomplish.

The project's goal is to determine where a contaminant will do the least harm, and then manage it accordingly. Toxic substances demand such a cross-media analysis, says program manager David Morell, because they can't be made to vanish but have to be tackled somewhere.

Similar studies are ongoing in Baltimore and Philadelphia, but so far integrated evnironmental management is an EPA experiment, not the norm.