[CPEO-MEF] TCE challenge at Orion Park

[Lenny Siegel <lsiegel@cpeo.org>]

THE TCE CHALLENGE AT MOFFETT'S ORION PARK HOUSING AREA
Lenny Siegel
December, 2004

Background

The Orion Park Housing Area is one of the last remaining environmental
challenges associated with historic contamination at the former Moffett
Naval Air Station, adjacent to my community of Mountain View,
California. Orion Park has underlying groundwater contamination with TCE
and other volatile organic compounds, and Navy-run investigations
suggest that some of the military families may be subject to hazardous
levels of toxic air contamination. Somehow, the Orion Park plume escaped
detection until 1999, when NASA detected TCE in downgradient
groundwater. Subsequent sampling found widespread TCE readings in the
hundreds of parts per billion range in the top two aquifers. There is no
question that the groundwater needs to be cleaned up, but because it is
not clear where the contamination comes from, the cleanup process is
proceeding much too slowly.

Orion Park covers about 72 acres, separated from the main Naval
installation by NASA Ames Research Center, which took over most of the
rest of Moffett Field in 1994. Orion Park, along with two other military
housing parcels, was transferred to the Air Force at that time, but
after another round of base closure it was transferred to the Army,
which now operates the housing for the families of military personnel
still stationed at Moffett as well as other locations in the San
Francisco Bay Area. Following the demolition of 32 substandard
buildings, there are more than 400 remaining housing units, not all of
which are occupied. The Army initially included Orion Park in its plan
to privatize, refurbish, and reconstruct Moffett military housing, but
the contamination has delayed this portion of the project..

Vapor Intrusion

Groundwater is shallow (at points less than 10 feet below ground) at
Orion Park, so the community and regulatory agencies pressured the Navy
to conduct a series of vapor intrusion investigations at the site. No
matter what its sampling finds, the Navy always concludes that there
isn't a vapor intrusion problem. 

At the November 2004 meeting of the Moffett Field Restoration Advisory
Board, the Navy gave the results of its sampling of representative
vacant units. It found indoor air concentrations of TCE, in the range of
1.5 to 3 micrograms per cubic meter, in two Orion Park units, about 10
percent of those sampled. (In one of those units, the November, 2003
readings were lower.) These results were not only far above U.S. EPA
Region 9's stringent .017 micrograms per cubic meter screening level,
but they were undeniably above California's enforceable standard of .96
micrograms per cubic meter, corresponding to old risk characterizations
of one excess lifetime cancer per million people.

Yet the Navy concluded, "There is no significant vapor migration from
any of the chemicals into indoor air from contaminated groundwater."
That is, there is no cause for concern that contamination was found in
the vacant units because, after all, they are vacant. No one is being
exposed. However, when the investigations began, the Navy selected
representative vacant units, instead of occupied units, to avoid
interference from household products. The "hits" in vacant units suggest
that some of the residents of other apartments are being exposed as
well. 

The Navy also found, "There is no apparent correlation between air
sampling results and the presence (or absence  of groundwater
contamination." This argument is spurious, too. The two units with
significant vapor intrusion are in fact located above some of the
highest TCE concentrations in the groundwater. The fact that other units
above tainted groundwater didn't show vapor intrusion may be because
they are effectively sealed off or vented, or because there are
preferential pathways leading the vapors in another direction. It does
not undermine the conclusion that vapor intrusion is occurring at some
Orion Park buildings.

Whose Problem?

Even if the Navy agrees that action should be taken, it doesn't agree
that it should pay. At Orion Park, each potentially responsible party -
the Navy, NASA, and a group of electronics companies - has presented
radically different plume maps, based upon essentially the same data.

This is the underlying challenge. Records show that Orion Park has been
used for housing and, before that, agriculture. There is no obvious
source of TCE on site. The Navy argues that it comes from the south,
from the far side of Highway 101, but it says it cannot sample off site
there because the contamination is off-site and upgradient - that is,
not from Navy activities. The electronics companies south of 101 say
there is no link to their plume, which is further east. The scanty
evidence is thus far inconclusive.

Meanwhile, NASA is installing a permeable reactive barrier to intercept
and treat the Orion Park plume where it enters Ames Research Center -
the portion of the Moffett complex that NASA owned even before base
closure. NASA argues that the Navy should conduct a full remedial
investigation and feasibility study, under the Federal Facilities
Agreement that it signed for the Moffett Field "Superfund" National
Priorities List site. But the Navy apparently doesn't agree that Orion
Park is within the boundaries of the Moffett NPL site.

NASA also reminds the Navy of the Memorandum of Understanding (MOU) that
it signed with NASA at the time that the bulk of the base was
transferred to NASA: "As part of that MOU, the Navy agreed to address
any contamination migrating from the former [Naval Air Station Moffett
Field], regardless of the source of that contamination."

EPA has been able to get the Navy to lead groundwater and vapor
intrusion investigations at Orion Park, but it appears unable to force
it to fund south-of-101 sampling. It is looking for such money
elsewhere, but even if it is able to determine the likely source of
contamination, it won't be able to fund remedial action.

For more than 15 years, community activists have watched potentially
responsible parties fight over liability for environmental cleanup at
Moffett, and our view has been consistent. While we would like the
allocation of responsibility to be fair, based upon the "polluter pays"
principle as much as practical, we don't want investigations and
remediation delayed. That is, EPA should require one or more responsible
parties to take action, and they all can sort out the financial
liability later.

At Orion Park, that means that EPA should require the Navy to conduct a
full remedial investigation and feasibility study, including off-site
investigations that might lead to the identification of other
responsible parties. If indeed another financially viable responsible
party is identified, then it should contribute to the remediation. We
wouldn't necessarily object to EPA contributing funds to the off-site
investigation, but we don't want essential action delayed while EPA
staff stand outside department stores ringing bells.

Today, significant levels of TCE and other compounds are polluting the
groundwater, and military families are being exposed to contamination at
levels that are unhealthy and which are likely to delay rehabilitation
or replacement of old housing units. At Orion Park, Cleanup is overdue.

-- 


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
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