Silicon Valley's tech waste problem
By Jane Meredith Adams Special to the Chicago Tribune
January 28, 2003
SAN FRANCISCO -- In Silicon Valley, the land of technological whiz kids, astronomically expensive bungalows and glorious palm trees, the underside of the computer revolution keeps seeping up--literally.
The valley, located about 25 miles south of San Francisco, has been struggling for more than a decade to deal with semiconductor manufacturing solvents that have seeped into the groundwater, a problem that has made pricey Silicon Valley the home of the largest concentration of Superfund toxic waste sites in the nation.
Now the news is worse: The Environmental Protection Agency said last week that the suspected carcinogen trichloroethene, known as TCE, may be many times more harmful than originally thought, and that vapors from the substance have been found inside homes and office buildings.
In addition to the Silicon Valley sites, the EPA said that this new assessment of the risk of TCE also may affect between 500 and 750 Superfund sites across the nation.
`Round-the-clock exposure'
"The sampling data I've seen thus far suggests that a large number of people in Silicon Valley might be breathing TCE at levels higher than what the EPA provisionally considers acceptable," said Lenny Siegel, executive director of the Center for Public Environmental Oversight and a resident of Mountain View, Calif., which has one of the largest concentrations of TCE-contaminated groundwater.
"It's round-the-clock exposure for those of us who live in this area," Siegel said.
In the 1960s and 1970s, businesses including Fairchild Semiconductor Corp., Intel Corp., Raytheon Co., NEC Electronics and Mitsubishi used TCE to clean silicon wafers and disposed of thousands of gallons of TCE in underground metal and fiberglass tanks, according to the EPA.
The tanks corroded and leaked, although it was years before the damage was discovered.
The corporations involved are cleaning up the sites, although they no longer own or operate the former facilities.
The EPA said the solvents have not affected the drinking water in Mountain View because most of the community's water comes from the Hetch Hetchy Reservoir in the Sierra Nevada. Other sources are deep wells and treated surface water not located near Superfund sites.
Residents getting alarmed
When managers from the EPA traveled to Mountain View last week to give citizens an update, many residents expressed concern that their health and property values were in jeopardy. "The news is always presented as `Be not alarmed,'" said Barbara Goodwin, who lives 1 1/2 miles from toxins buried under what is considered to be the birthplace of Silicon Valley: the former Fairchild Semiconductor plant where engineers made the first computer chips in the world. "But I'm alarmed."
Goodwin, 66, has lived in the valley for 10 years and has suffered breast cancer and chronic bronchitis. "I don't think it's smart to be here," said Goodwin, a former nurse.
According to the draft of an EPA toxicity report, TCE is 5 to 65 times more hazardous to human health than previously understood. The agency said that vulnerable populations--which include children and some people with chronic health problems--may face higher risks of kidney, liver, cervical, prostate and lymphatic-hematopoietic cancer.
"There are no immediate health risks," said Alana Lee, EPA project manager for two of Silicon Valley's 29 Superfund sites. "We're really making sure there would be no long-term health effects at the site by taking air samples." The indoor and outdoor sampling is set to begin this spring, she said.
Soil removed, walls erected
Cleanup has consisted of removing contaminated soil, building walls to contain the contamination, and pumping TCE-contaminated groundwater into "air-strippers"--structures that allow TCE to evaporate into the air. Using previous toxicity standards for TCE, the EPA said in 1999 that the emissions from the air-strippers do not pose a significant health risk to occupants of the buildings that have been erected on Superfund sites, including Netscape Communications Corp. and Nokia. Air in those locations will now be retested.
Ted Smith, executive director of the Silicon Valley Toxics Coalition, said many workers have no idea that toxic waste is underneath and around their companies. "Rising from the ashes of the semiconductor industry have been new industries," Smith said. "They've located here without informing their workers that they were coming to work on top of a Superfund site."
Most U.S. semiconductor manufacturing is now done in other parts of the country, including Albuquerque and Austin, Texas, using safer standards for underground storage tanks.
Vapors rising into buildings
In addition to the TCE that is sent into the air through the air-strippers, vapors are rising from the groundwater into the air and entering buildings through floor cracks and plumbing ducts, the EPA said. At the Navy's former base at Moffett Field, which is located across U.S. Highway 101 from former semiconductor plants and on top of its own contaminated groundwater, tests have found TCE at a playground and inside apartments. The levels of TCE are considered to be a potential long-term health risk using the EPA's new draft toxicity assessment.
Dag Nybo, a customer support manager at a technology company, said that he and his wife have begun a crash-course in researching TCE and worry about the health of their children, ages 3 and 1. They live two blocks from a Mountain View Superfund site with TCE.
"My stomach's in a knot," Nybo said. He's thinking of moving about 15 miles away and at the same time, he's worried about publicizing his concerns because his assets are tied up in his house. "I'm concerned about a complete loss of property values," he said.
Jeffrey Segall, a Mountain View resident who has a PhD in chemistry, says that the issue now is whether the EPA will act. "The concerns I've been expressing for a couple of years now have been validated," he said. "Three years ago the EPA was saying, `It's within the margin of safety.' Now they're saying, `We're not so sure.'"
Copyright © 2003, Chicago Tribune
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