TCE Cleanup Standard Challenged

[Lenny Siegel <lsiegel@cpeo.org>]

The Loma Prietan (Newsletter of the Loma Prieta Chapter of the Sierra Club
July/August 2004
http://lomaprieta.sierraclub.org/lp_current.html

Bush Administration Pushes Weaker Cleanup Standards for Toxic Sites

By Lenny Siegel, Director of the Center for Public Environmental Oversight

In January 2003, the U.S. EPA began a new approach to public health
protection in Mountain View, where groundwater is contaminated with
trichloroethylene (TCE), a cancer-causing solvent used widely in the
past. EPA officials told the public that TCE was 5 to 65 times as toxic
as previously believed, and warned that TCE in groundwater could
vaporize into overlying homes and other buildings. Long-term exposure to
low levels of TCE is believed to cause cancer, liver disease, and
neurological problems, plus a host of other ailments. The companies and
federal agencies responsible for cleanup initiated comprehensive new air
sampling programs, and the results are cause for concern. However, the
Bush Administration reportedly plans to reverse the EPA's recent
toxicity assessment. When that happens, it will undermine the studies
and remediation, not only in Mountain View, but throughout Silicon
Valley and the nation.

In the early 1980s, TCE pollution was found at dozens of Silicon Valley
sites. One of the largest chemical plumes was found in the Mountain View
industrial area that was the birthplace of the commercial semiconductor
industry. Today it's known as the Middlefield-Ellis-Whisman (MEW) Study
Area. Led by the Silicon Valley Toxics Coalition, the local community
campaigned successfully to add it to the EPA "Superfund" National
Priorities List.

The regulatory agencies and responsible parties (polluters) gradually
undertook a thorough surface and groundwater cleanup program. In
addition, the city of Mountain View relocated a drinking water supply
well and undertook routine water testing to ensure that the public would
not be exposed to TCE and other contaminants. The community-based
Restoration Advisory Board established to oversee cleanup efforts at
Moffett Field became the model for similar boards at hundreds of
contamination sites in the United States.

In Mountain View, in contrast to many other polluted communities, the
system seemed to be working. However, following the Navy's October 2000
discovery of TCE contamination just 10 feet below the Orion Park
military family housing complex, there was concern that contamination
might be entering homes. We called for indoor air sampling. As the issue
gained prominence in other regions of the nation, EPA began a national
effort to understand and respond to what became known as "vapor
intrusion."

Volatile compounds in shallow groundwater vaporize and rise. They move
up through the soil or gaps in foundations into buildings and outdoor
air. The original cleanup programs did not consider this potentially
hazardous pathway.

In August 2001, EPA released its draft toxicity assessment for TCE. In
summary, it found that children were more susceptible to TCE exposure
than adults, and that TCE was 5 to 65 times more toxic than previously
believed. EPA's Science Advisory Board peer review praised the
"ground-breaking" assessment and urged moving quickly to implement the
stronger standard. In 2002, EPA Region 9 adopted new, more stringent
screening levels for TCE in both water and air, and with public input it
began a new air sampling program. To oversee responses, the community
formed the Northeast Mountain View Advisory Council (NMAC). For more
information, see www.whisman.net/nmac/.

Relatively high levels of TCE vapors have been found in a number of
buildings, including some homes. Low levels of TCE have been found
outdoors, inconsistently, throughout the area, including at Slater
Elementary School. Since TCE in the air dissipates quickly, there must
be persistent sources in the northeast Mountain View area.

The local community appreciates the extent to which the responsible
parties, property owners, and regulatory agencies are studying this
problem. Some of the work is cutting edge, but there's room for
improvement. Air contamination above shallow groundwater plumes seems
high enough and consistent enough to merit an additional response. If
continuing studies bear this out, more cleanup may be necessary.

This is the direction where the local EPA's program in Mountain View is
headed, but it could grind to a halt. The Air Force, on behalf of the
entire Defense Department, has challenged the EPA's TCE toxicity
assessment. It is challenging the science, but it's no secret that Bush
appointees consider the cost of investigation and cleanup to be
prohibitive. Reportedly, EPA will delay the new standards and instruct
its regional offices not to use the more protective levels.

This is similar to what has happened with EPA's health assessment for
perchlorate, a principal component of solid rocket fuel. Perchlorate
pollution has been found at many facilities through the Southwest, and
locally at a former highway-flare plant in southern Santa Clara County.
In fact, perchlorate-producer Kerr McGee dumped so much perchlorate into
Lake Mead that the Colorado River, which delivers water to 20 million
people, is contaminated. At the Bush Administration's behest, EPA has
deferred establishing a federal perchlorate health standard.

If the reports about EPA's plans for TCE are true, public health in
Mountain View, and probably hundreds of other sites, will be sacrificed
to the concerns of polluters and the Bush Administration.

After months of requests by one of the NMAC board members, EPA sampled
the air in her home. The results announced in May showed that in her
11-year-old son's bedroom, where he has apparently lived above a TCE
plume during his entire life, TCE was found at levels well above the new
health screening level. If that screening standard is weakened, then he
would supposedly be "safe," even though EPA's Science Advisory Board
commended EPA for coming up with health-based exposure levels designed
to be protective for children.

Local communities are more empowered than most. For the past quarter
century we have been able to get the government and private parties to
address TCE and other pollution in our community in an effective, open
fashion. However, if national standards are rolled back, we'll become
guinea pigs, exposed to unhealthy levels of contaminants until national
policy-makers decide that the key purpose of environmental protection is
to safeguard public health.

--


Lenny Siegel
Director, Center for Public Environmental Oversight
c/o PSC, 278-A Hope St., Mountain View, CA 94041
Voice: 650/961-8918 or 650/969-1545
Fax: 650/961-8918
<lsiegel@cpeo.org>
http://www.cpeo.org