[CPEO-MEF] EPA's Mountain View Indoor Air Meeting

[Lenny Siegel <lsiegel@cpeo.org>]

On January 22, 2003, U.S. EPA Region 9 convened a public meeting in my
community, Mountain View, California, to discuss indoor air
contamination at four federal cleanup sites. Three of those sites -
Moffett Federal Airfield, the Middlefield-Ellis-Whisman (MEW) Study
Area, and JASCO Chemical - are on the "Superfund" National Priorities
List (NPL). The fourth, GTE Government Systems, has been addressed under
the Resource Conservation and Recovery Act. MEW, named for surface
streets that help define it on the map, actually combines three separate
NPL sites.

Remedies are in place for all but two recently discovered groundwater
contamination plumes on the four sites. Two sites have undergone
redevelopment; redevelopment is planned for other two. Current land uses
include commercial/office space and housing.

In the fact sheet announcing the meeting, EPA explained, "EPA has been
overseeing cleanup activities at these four sites for many years.
However, new information concerning TCE [trichloroethylene] and
potential indoor air quality impacts from site contamination has led EPA
to begin additional studies and take actions concerning the
groundwater-to-indoor-air pathway."

Probably over 400 people attended the afternoon poster session or the
formal evening meeting. Many people stayed for hours. Most appeared to
be residents or employees at the four sites or adjacent properties. As
denizens of one of the towns that form the heart of Silicon Valley, many
are technical or medical professionals, capable of quickly understanding
the technical material presented at the meeting.

In lay terms, the meeting consisted of two parts. First people from the
government told the audience not to worry. Then, in the question and
answer period, people said, "We're worried."

In more technical terms, EPA experts briefly described how risk
assessments are conducted, and they explained the "vapor intrusion
pathway." They also covered the new national EPA toxicity assessment for
TCE. Then representatives from NASA and the Navy profiled conditions and
responses at Moffett Field, and EPA personnel explained what is
happening at the three private sites.

Mountain View is one of the first locations, around the country, where
EPA is applying recently developed science on the indoor air pathway, as
well as the findings of the toxicity assessment. That assessment, which
has concluded that TCE is 5 to 65 times as toxic as previously believed,
is provisional, but Region 9 has already incorporated it into its
preliminary remediation goals - concentration levels used primarily for
screening purposes. In addressing the Mountain View sites, EPA is saying
that existing remedies may not be as protective as it originally
concluded. It has requested or required indoor and outdoor air samples
at the Mountain View sites, and it is prepared to call for additional
cleanup and mitigation measures.

When I spoke, I commended EPA for recognizing the indoor air pathway and
utilizing the results of the toxicity assessment. Most of my neighbors,
however, were less charitable. They viewed EPA's recent response as too
little, too late, since they've been breathing contaminated air - at
levels that may or may not represent a significant risk - for years. A
number of them - probably trained as engineers - tried to pick apart the
official risk assessment. One resident reminded everyone of the report,
from the weekly Mountain View Voice, that several long-time residents on
one street near the MEW Study Area had contracted Parkinson's disease.
EPA scientists said they didn't know whether there might be a link.

_From what I heard, I've drawn at least five key observations:

1. Perhaps because few of the meeting's participants actually live
directly above the plumes, they expressed more concern over outdoor air
than indoor air. In addition to any direct migration through the soil,
groundwater treatment systems in the area directly vent small quantities
of untreated volatile organic compounds into the air, exposing people
who live or work nearby.

2. Participants did not accept the subtraction of "background" risk from
risk calculations. There have been reports that TCE is actually found in
ambient air in Silicon Valley at levels that may cause health impacts.
Indeed, the Navy has suggested that ambient air contamination is the
source of indoor TCE detections at Moffett. (I'm skeptical.) However,
since TCE (unlike common background contaminants such as arsenic and
manganese) does not occur in nature, toxic air pollution that does not
directly rise from the groundwater plumes probably enters the nearby air
indirectly, from the plumes and treatment systems. The responsible
parties (polluters) still need to address the "background" risk.

3. Members of the audience also felt that the risk assessments presented
tended to fragment risk. Isn't risk higher if someone goes from a
contaminated home to a contaminated workplace? NASA's assessment of
proposed campus housing assumed a five-year maximum residence, but what
if a person moves to another contaminated property? How are exposures to
multiple contaminants considered? Are the effects synergistic? Even if
each source generates levels of risk that are deemed acceptable,
receptors (people) may suffer unacceptable combined exposures

4. Though a few of us have been watching some of these sites for more
than twenty years, most of the people at the meeting appeared to be
relatively new arrivals in time. In fact, the area around MEW and the
GTE site have experienced gentrification. There was no way for the new
residents to participate in the original cleanup process because they
weren't here, yet they must live with the impact. Where redevelopment
happens or turnover occurs for other reasons, the long-term public
participation process should better inform them and listen to each new
generation of public stakeholders. 

The parties aren't starting from scratch. The Moffett Restoration
Advisory Board, generally considered a model for effective public
oversight, meets regulatory, and EPA arranged for concerned community
members to meet with representatives of the MEW companies a couple of
years ago, but the January 22 meeting demonstrated that even more
communication is needed.

5. Finally, though most of the community participants in the meeting
probably don't know the jargon to express it this way, I heard a general
note of opposition to the concept of risk-based cleanup. Instead of
spending a great deal of time and money calculating the likely risk -
based on this year's science - of exposure to off-gas from the
groundwater treatment systems, the audience clearly indicated its desire
to have those emissions captured or treated. That is, rather than guess
how much exposure is unsafe, and keeping the levels just below that
figure, they wanted a common sense cleanup.

EPA's meeting is likely to generate continuing public involvement at the
private sites. (Those channels are already open at Moffett.) Activists
have called for the formation of a Community Advisory Group, and they
expect the private responsible parties to fund its operation. The
Silicon Valley Toxics Coalition has taken initial steps to revive its
Technical Assistance Grant for the MEW Area.

Perhaps Mountain View, with its educated, empowered, yet diverse
population will again be a model for public participation. This time it
will be to oversee long-term site management. Members of the community
expect to influence the five-year review, the redevelopment of Moffett,
and activities at the other sites.

Despite the frustration expressed by many of my neighbors - or perhaps
because they had the opportunity to express that frustration - EPA and
the community are off to a good new start.


-- 


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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