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发帖数: 1416 | 1 UPDATE, March 25, 2013: This story updates to include a link to the
Geosyntec contamination report.
For at least two months, Google employees were exposed to excessive levels
of a hazardous chemical after workers disabled a critical part of the
ventilation system at the company’s new satellite campus on a Superfund
toxic waste site, records show.
From mid-November to mid-January, levels of trichloroethylene, or TCE,
exceeded concentrations considered safe by the federal Environmental
Protection Agency at a Google office complex in Mountain View, according to
a detailed report to the EPA obtained by the Center for Investigative
Reporting. The buildings sit on a Superfund site three miles from the
company’s headquarters.
TCE, an industrial solvent used in making computer chips, is known to cause
cancer and birth defects. The EPA recently adopted a more stringent safety
threshold for TCE after finding it can cause cardiac abnormalities in
developing fetuses.
Pregnant women who are exposed to low levels of the chemical during a
crucial three-week period in their first trimester face an increased risk of
having a baby born with holes in the heart, a 2011 EPA analysis found.
In response to questions from CIR, the EPA said last week that it would “
take a more aggressive approach to ensure prompt action” when TCE levels at
the Superfund site exceed safe levels. The agency also said women of
childbearing age should consult a doctor if they are concerned they were
exposed to TCE.
“While EPA cannot verify how many employees were in the Google buildings in
question, we encourage women who are concerned about potential exposure to
contaminants at the site to speak with their obstetrician or pediatrician,”
agency spokesman David Yogi said in an email.
More than 1,000 employees work in the two buildings where elevated levels of
TCE were found. Google confirmed that employees were exposed to the
hazardous chemical but would not say how many.
Google spokeswoman Katelin Todhunter-Gerberg said employees in the two
buildings had access to information on the company’s intranet, but she
declined to say whether they were warned of any health risk. She said
employees were never in danger.
“We take several proactive measures to ensure the healthiest indoor air
environment possible in our workplace,” she said by email.
Google, which was not involved in manufacturing chips with TCE, is a
newcomer to the Superfund site. It leased buildings previously occupied by
Netscape Communications and began moving employees in last summer.
During the 1960s and '70s when computer chip manufacturers such as Intel
Corp., Fairchild Semiconductor Corp. and Raytheon Co. occupied the site,
large quantities of contaminants leaked or were dumped there.
In 1981, TCE was discovered in the soil and groundwater beneath the three
companies’ plants. The federal government designated the area as a
Superfund site, and since 1989, more than 100,000 pounds of TCE and other
contaminants have been removed.
When Netscape occupied the Google site, a controversial “air stripper”
operated there for more than a decade, emitting toxic chemicals into the air
without monitoring, according to Lenny Siegel, executive director of the
Center for Public Environmental Oversight, an activist group based in
Mountain View. In 1999, Netscape was acquired by AOL, which declined to
comment.
The Superfund site covers about 400 acres above the contaminated plume in a
Mountain View neighborhood near Middlefield Road, Whisman Road and Ellis
Street
The site is now home to about 85 businesses, including the software firm
Symantec Corp., the insurance company eHealthInsurance, a patent law firm, a
baby ultrasound center, an adoption service, a restaurant and a cafe. All
told, thousands of people work at the site. Companies contacted by CIR
declined to discuss any potential health risk.
Google leases its campus from Keenan Lovewell Ventures, a Palo Alto property
developer. Perry Palmer, the partner who handled the lease, would not
discuss any disclosure he may have provided Google.
Over the years, the plume of contamination has spread to surrounding
residential neighborhoods and nearby Moffett Field. In December, TCE was
found under more homes outside the boundaries of the Superfund site.
The main threat from TCE is posed by vapors from the contaminated
groundwater seeping into buildings and accumulating in interior spaces.
The new Google campus features four two-story office buildings linked by
steel-reinforced fences that require a key card to enter. Inside is a
stretch of grass and food carts, giving the area the feel of a college
campus.
On a recent afternoon, young women, pregnant women and visitors with young
children could be seen relaxing in the courtyard. One Google employee who
was visibly pregnant was asked if she was aware of risks associated with TCE
exposure.
“We’re really not allowed to talk about it,” she said. “Sorry.”
The danger of vapor intrusion into buildings was not as well understood when
the EPA and the city of Mountain View agreed in the 1990s to allow
commercial use of the site.
In 2012, the EPA’s Region 9, which oversees California, began setting
stricter standards for TCE exposure.
Region 9 now requires that it be notified if the level of TCE in a building
exceeds the safety threshold of 5 micrograms per cubic meter of air. One
recent EPA document indicates that prolonged exposure at even lower levels
may cause cancer.
Since 2011, the EPA also has required that new buildings at the Mountain
View Superfund site have subslab ventilation systems and vapor barriers to
prevent TCE from accumulating indoors.
But since the Google campus was renovated, not newly built, the company
relies on a “positive pressure” ventilation system to pump fresh air into
the building and keep toxic vapors from collecting.
A 1,300-page report prepared by environmental consulting firm Geosyntec
Consultants, Inc. and obtained by CIR from the EPA details the extent of the
contamination at the Google site and efforts to correct it. The report was
commissioned by Schlumberger Technology Corp., the oilfield services company
, which acquired part of the site in 1979 and assumed legal responsibility.
The problem at Google was discovered when routine air sampling found TCE at
a level of 7.8 micrograms per cubic meter in a hallway of one building on
Nov. 21. The EPA was notified as required. It is unclear how long the levels
had been above the danger threshold. The previous sampling in September
2010 found nearly nondetectable levels.
In an effort to reduce the vapors, workers sealed cracks in floors and walls
where TCE might get in. But despite their efforts, samples collected on Dec
. 29 found the problem was getting worse: TCE exceeded the 5-microgram
safety threshold in five locations in two of the four buildings.
On Jan. 14, the team finally inspected the heating, ventilation and air
conditioning system (often referred to as HVAC) and found it had been
switched to manual, which prevented the positive pressure system from
running continuously.
The move was motivated by a desire to keep the buildings warm as the weather
turned colder in the fall, the report shows.
“The HVAC systems were operating in a manual mode (i.e. automatic system
was overridden) in order to maintain the temperature in the buildings,” the
Geosyntec report concluded.
The system was reset to automatic on Jan. 19. Three days later, tests showed
that TCE vapors in the offices had been reduced to acceptable levels.
If employees were exposed to dangerous levels of TCE without warning, Google
could be vulnerable to legal action under Proposition 65, California’s
tough anti-toxics law, which sets a cancer risk threshold of 50 micrograms
of TCE per day. Someone working in an office with TCE vapors measuring 5
micrograms per cubic meter would inhale that amount in 10 hours.
After CIR questioned why there was no risk level for birth defects under
Prop. 65, the state Office of Environmental Health Hazard Assessment
announced last week that it would examine whether TCE also should be listed
as a chemical known to the state to cause reproductive harm.
The EPA said in its email to CIR that it would establish a new notification
system for companies at the site and launch a website to provide information
to the public. It also said it will make its toxicologists available to
speak with employees’ physicians about TCE.
“Everyone who works or lives near the (Mountain View) Superfund site should
have access to clear and timely information about the contaminants at the
site,” said EPA Region 9 Administrator Jared Blumenfeld.
This story was edited by Richard C. Paddock and copy edited by Christine Lee
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