Toxic gas enters offices Toxic gas enters offices (August 29, 2003)

Through electrical conduits and cracks in the floor, TCE moves from ground water into buildings

By Justin Scheck and Tamar Lando

Toxic gas is moving out of the ground and into a group of office buildings in north Mountain View.

According to data released this month by the U.S. Environmental Protection Agency (EPA), the air in at least five separate office developments off Middlefield Road has high enough levels of a cancer- causing solvent to warrant immediate action.

EPA officials say that health risks are long term; the chemical vapors do not present an immediate danger, but could raise the odds that a longtime worker in these buildings will get cancer at some point in his or her life. The agency is therefore trying to lower TCE levels in the offices as quickly as possible, at the same time working on a long-term plan to reduce the levels of chemicals that can enter buildings.

In the meantime, environmental advocates are saying that no amount of cancer-causing chemicals -- even at a barely detectable level -- is safe; they want EPA to speed up the cleanup of contaminated ground water and to ensure that the buildings are toxin free.

The main chemical of concern is trichloroethene (TCE), a solvent used extensively in the manufacture of computer chips. From the late 1950s through the '80s, seminal chip developers like Intel, Raytheon and Fairchild leaked TCE from underground tanks into shallow ground water.

The factories were located in the area bounded by Middlefield Road, Ellis Street and Whisman Road, called the "MEW" site. Contamination there has been the subject of a decades-long federal Superfund cleanup, but only recently -- after the EPA said last year that TCE is far more toxic than previously thought -- have tests been conducted to see whether toxins in the ground are insinuating themselves into buildings above. These tests came on the heels of recent studies which have also shown elevated TCE levels in outdoor air around the city.

While environmentalists are concerned about the chemical's health effects on workers, tenants of the toxic sites have had mixed reactions, some saying the levels are too low to worry about.

This past spring, tests found TCE in trace amounts in most of the buildings that sit atop the tainted ground water. But according to Alana Lee, EPA's project manager for the site, five office complexes had levels of the chemical that EPA considers risky. Some of these buildings had TCE at levels where, for every 1,000 people exposed over 25 years, there could be at least one extra cancer case; some offices had higher levels, although most were lower.

Highest risk

John Fisher owns 644 National Ave., where his company, Test Equipment Systems, employs about 12 people. In that building, TCE levels in the basement -- which Fisher said is used as storage space -- were more than 100 times EPA's safe level due to fissures that allow TCE-laced ground water to move into the basement. Levels were considerably lower on the second and third floors, though still more than 10 times the safety threshold. But Fisher -- who works in the building -- says he's skeptical that there is any danger at hand.

"I really don't see it as a big deal," he said, adding that while he believes extremely high levels of TCE exposure are dangerous, he is not convinced that EPA's new, lower thresholds are based on sound science.

"Just because they lower the levels, I'm not buying off that the risk is higher than they thought. There's all sorts of politics in EPA. ... Until there's some sort of consensus, I'm sticking by the fact that the levels there are kind of low," he said.

Fisher's building is part of the former Fairchild Semiconductor plant, a complex that now houses a new generation of tech companies. Tests found relatively high levels in three nearby buildings on National Avenue that shared one trait: their heating and ventilation systems were not working.

TCE seems to be moving into the former Fairchild buildings through cracks in their concrete foundations, Lee said. While concentrations were highest near these cracks, ambient air inside the buildings' work space had levels of TCE that far exceed what EPA says is safe, in some cases more than 10 times the safety threshold. Without working ventilation systems, Lee said, TCE is believed to build up within the office space.

George Fiegl's company, Adema Technologies, grows silicon crystals for solar cells in another of the old Fairchild buildings, at 401 National Ave. He says the findings don't worry him.

"I'm not concerned. I think the levels are low," he said, although tests show TCE in office air at more than 10 times EPA's safe level. Lee said cracks in the building's floor have been patched, and that building owners are planning to turn on a ventilation system to reduce TCE levels. But Fiegl argues that the ventilation is costly and unnecessary.

He said that he spends 16 to 18 hours a day in the building, and hopes to one day buy it (he owned it until his former company, UniSil, went bankrupt in 1999). "People have worked here for a long time and don't see any reason for alarm," he added. Fiegl currently has about 15 employees, although he said that generally, only a couple are in the office at a time.

Fisher said he is planning to install a ventilation system recommended by EPA that should lower TCE levels. A third building with high amounts of TCE, 425 National Ave., is newly built and not yet occupied; Lee said it will be retested once a ventilation system is installed and running.

Elevated risk

Two other complexes in the MEW area had high levels of TCE entering from the ground, but ventilation systems dissipated the chemical to levels below the EPA's safety threshold.

Energy Sales occupies 365 East Middlefield Rd., a former Intel factory where TCE levels in ambient air were below EPA's threshold, but near cracks in the floor, levels exceeded 10 times the safe amount.

"I am truly concerned about it. My problem is, I don't know who I can talk to to get unbiased information. EPA has one point of view, Intel has another," said Valerie Franco, the Energy Sales manager. She said her company has been leasing the building -- which is co-owned by 49ers legend Y.A. Tittle -- since 1991.

She said that EPA and the building's owners have been working to improve ventilation and seal cracks in the floors. But for her and her workers, the data is both worrying and difficult to digest.

"Though it's public information, I don't think we know how to interpret it -- we're not scientists or medical experts," she said.

The Middlefield building is old, dating from the '60s. The situation at 350-380 Ellis St. is quite different.

The former site of a Raytheon factory, it has housed Veritas' high-tech campus since 2000. Lee said an impermeable concrete slab beneath the buildings has apparently served its function of preventing TCE intrusion. But the chemical is entering offices via electrical conduits that lead from equipment housed in underground vaults.

While ambient air inside offices showed readings near -- and in one case, exactly at -- EPA's safe threshold, air in the vaults and where the electrical conduits enter the office buildings had far higher readings.

Veritas officials could not be reached for comment before press time.

What's next?

As EPA and tenants of occupied buildings work to minimize levels of toxic gas, environmental health advocates are calling for a new approach to dealing with the MEW site.

Amanda Hawes began litigating toxics cases more than 20 years ago, and has sued a host of Silicon Valley companies for exposing workers to TCE, often in the tech manufacturing process. She challenges EPA's assertion that there exists a "safe" exposure level to TCE or any other carcinogen, and 25 years ago started an unsuccessful effort to ban the chemical.

"Nobody should be exposed to these things. ... This is like Son of Sam that this stuff is still around," she said.

Hawes argues that EPA's approach to dealing with TCE often follows a flawed presumption: that "the solution to pollution is dilution." This notion, she said, is tied to the belief that small amounts of a dangerous chemical are not dangerous; Hawes disagrees, saying that over the past two decades, science has repeatedly lowered the "safe" exposure level to TCE.

But, she added, "No matter what concentration workers are exposed to, someone will always get up and say this wasn't enough to cause a problem." In the end, she said it is the responsibility of government and employers to make sure that workers are not exposed to any TCE, even "safe" amounts.

Lenny Siegel, a longtime Mountain View resident and head of the Center for Public Environmental Oversight, said that once TCE levels in these offices are brought below EPA's threshold, the agency must start looking at ways to quickly reduce amounts of the chemical in shallow ground water. Although a complex filtration system has been working for nearly 15 years to remove TCE from MEW ground water, Siegel said its progress has been too slow to solve the problems with indoor air.

"I think it's pretty clear that TCE is moving out of the ground over a wide area. ...There's this plume of ground water down there. It's not just coming up into the buildings. It's coming up everywhere," he said.

Lee said that once short-term mitigation measures are in place -- patching cracks where TCE can enter, turning on ventilation systems -- indoor air will be retested. Most of the results should be available by the end of next month. She said the agency is still studying the data, looking toward long-term solutions.

E-mail Justin Scheck at editor@mv-voice.com