[CPEO-MEF] Kelly Air Force Base (TX) Indoor Air

[Lenny Siegel <lsiegel@cpeo.org>]

[For a formatted version of this report, a 756 KB PDF file with photos, 
go to http://www.cpeo.org/pubs/KellyVI.pdf.]


Kelly Air Force Base: Indoor Air Testing Is Needed
by Lenny Siegel
April 2007

On April 10-11, 2007 I visited the former Kelly Air Force Base in San 
Antonio, Texas. I attended a meeting of the Restoration Advisory Board 
(RAB), met with community activists, and reviewed documents in the Air 
Force-sponsored repository in the San Antonio library.

Kelly was an Air Logistics Center, a major 4,000-acre industrial 
operation employing 30 thousand civilians at its peak. It was designated 
for closure in 1995, and it halted operations in 2001. In general, it 
has been a partial reuse success, serving as a home to private aerospace 
companies. The flight line was realigned to adjacent Lackland Air Force 
Base.

Contamination includes massive shallow groundwater plumes, containing 
tetrachloroethylene (PCE) and trichloroethylene (TCE), which flow under 
low-income, predominantly Hispanic neighborhoods east of the base. There 
are also releases of TCE, PCE, and other pollutants into Leon Creek. The 
Air Force has spent at least $331 million thus far on environmental 
projects, and it expects to spend a great deal more. Under the oversight 
of the Texas Commission on Environmental Quality (TCQ) and U.S. EPA, it 
has installed numerous innovative remedies, including in situ 
bioremediation at source areas and permeable reactive barriers.

I first visited Kelly Air Force Base in August 2003 as part of the 
National Environmental Justice Advisory Council's Federal Facilities 
Working Group. From that visit, meeting with community members at 
workshops and conference, and correspondence - strongly reinforced by 
statements by RAB members this April - I learned that members of 
adjacent neighborhoods blamed their health problems on exposure to 
pollution from Kelly. They also charged that the Air Force had spent 
most of its cleanup money enabling industrial reuse, ignoring the health 
of people in the neighborhoods. The groundwater remedies are designed to 
prevent additional off-post migration, but no action is being taken to 
clean up volatile compounds that have already pooled under the community.

The Air Force and other government agencies say that the claims of 
health injury are baseless because people don't drink water from the 
shallow aquifers. If there is no pathway, then the decision to let the 
PCE and TCE already under the neighborhoods degrade naturally, with 
monitoring, makes sense.

But since my first visit, I've wondered whether vapors from shallow 
groundwater contamination, well above 100 parts per billion in places 
for both PCE and TCE, was volatilizing and migrating into people's 
homes. If the inhalation pathway has been complete, that might explain 
some of the health problems that the neighbors associate with the 
contamination. It may also, as some community members want, lead to 
active treatment approaches that would more rapidly reduce groundwater 
contamination under the neighborhoods.

Recently, I found some data that reinforces my concerns. In a February 
2007 Public Health Assessment for the East Kelly area, the U.S. Agency 
for Toxic Substances and Disease Registry (ATSDR) reported maximum PCE 
and TCE concentrations in soil gas of 14,230 and 618 micrograms per 
cubic meter (ug/m3), respectively. Though ATSDR uses the 
Johnson-Ettinger model to predict currently acceptable (according to 
virtually every regulatory agency's action level) indoor air 
concentrations of .345 and .016 (ug/m3), that seems to be based on an 
extraordinarily low attenuation factor of about .000025.

Typically, however, (according to U.S. EPA's national data base), the 
attenuation factor is .02 (1/50) to .001 (1/1000), and some studies, by 
EPA's Office of Research and Development and the state of New York, 
suggest that in some cases the measured attenuation is even less 
significant. If the soil gas concentration near homes are close the 
reported maximums, that could indicate indoor levels of from 14 to 285 
ug/m3 for PCE and from 12 to .6 ug/m3 for TCE, generally above action - 
that is, requiring mitigation - levels, which are around 1 ug/m3 for 
both compounds in leading jurisdictions with active vapor intrusion 
programs.

The data doesn't prove that residents are being/have been exposed to 
unacceptable levels of these compounds, generally believed to cause 
cancer, but it suggests a need for indoor air sampling. If indoor 
testing above the highest plume concentrations indicates a problem, then 
widespread sampling is called for.

As I pointed out at the RAB meeting, the Air Force, at still-operating 
Hill Air Force Base in Utah (also an Air Logistics Center), routinely 
tests homes for vapor intrusion, and it is operating mitigation systems 
at many of them. According to Hill Air Force Base officials, they have 
tested 1400 homes, finding TCE in about 16%.

Furthermore, in researching the Administrative Record, I found a 
December 2000 letter from Laura Stankosky, an EPA Region 6 Scientist, in 
which she suggested indoor air testing:

"The model may indicate that the concentrations are below risk-based 
levels in the intermediate step of measured vapor monitoring wells but 
other numerous variables may be working to potentially create 
unsatisfactory conditions in the indoor air. The model does not take 
into account the various other factors that influence vapor migration, 
such as preferential flow paths caused by cracks in the soil, root 
holes, burrowing animal tunnels, subsurface conduits leading into 
buildings such as sewer and drinking water lines, etc. Actual sampling 
of indoor air could be justified as it would provide direct results; 
however, in measuring indoor air there is the problem of interference 
from household-originating vapors that would need to be addressed. Even 
with this hurdle, direct measurement would provide more definitive data."

The more recent soil gas data makes an even stronger case for indoor air 
testing. The Kelly neighbors have long sensed that something is wrong, 
but they haven't had the technical basis to reinforce their demands. The 
available soil gas data is strong enough to trigger indoor air sampling 
along with subslab soil gas and outdoor air sampling. Agencies such at 
the Air Force, TCEQ, and ATSDR should stop denying that there is a 
problem unless they have real, point-of-exposure data to prove it.



--


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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