[CPEO-BIF] My visit to Playa Visa (Los Angeles, CA)

[Lenny Siegel]

[For a formatted version of this report, with photos, download the 1.2 
MB Word file from http:www.cpeo.org/pubs/PlayaVista.doc.]


Playa Vista
Los Angeles, California
Lenny Siegel
Summer, 2006

On July 18, 2006, I visited Playa Vista, at nearly 1,100 acres one of 
the largest developments in the history of Los Angeles County, 
California. My host was activist Patricia McPherson, of the Grassroots 
Coalition (http://www.grassrootscoalition.org). McPherson and many 
others, including my parents, have opposed and/or criticized Playa Vista 
for its impact on one of the last remaining wetlands areas in Los 
Angeles, the massive seepage of methane gas from underground, and other 
problems, including toxic contamination.

On September 12 I met with officials from the Los Angeles Regional Water 
Quality Control Board (LARWQCB), the agency principally responsible for 
environmental cleanup at the site, and reviewed documents pertaining to 
volatile organic compounds at the site.

When I grew up in Culver City, just a few miles away, I knew the 
property as Hughes Aircraft. The flat area north of the Westchester 
bluffs and (a little further away) the Los Angeles International Airport 
contained its own airstrip. Indeed, one of the features of the new 
development is the historic hangar in which Hughes built the giant 
wooden aircraft known as the Spruce Goose.

After Hughes and its corporate successors stopped manufacturing on the 
site, the hangars were used for movie production. In the late 1990s (or 
maybe later), developers proposed a massive new community, to contain 
several thousand housing units, offices, and commercial development. A 
collection of environmental and other community groups, including 
McPherson's, organized in opposition. They challenged the scale of the 
development and the traffic it would generate, and they called instead 
for restoration of the historic wetlands ecosystem of the Ballona Marsh.

In 2002, the developers proposed a scaled-back development, and today 
the first phase, with 3,200 housing units, is nearly complete. Today its 
web site (www.playavista.com) touts a "new urbanist" lifestyle, and it 
advertises the restored Ballona Freshwater Marsh. The wetlands once 
covered more than 2,000 acres in the Playa Vista, Marina Del Rey, and 
Venice sections of Los Angeles. Now only about 200 acres remain.

Opponents warn that methane seeping from underground is an enormous 
threat to the safety of the occupants of present and future buildings. 
The local NBC affiliate, KNBC-4, won a Peabody Award for "Burning 
Questions," a four-part 2005 news series featuring McPherson and her 
scientific advisers, documenting the methane problem. In October, 2005 
opponents won a California Appellate Court ruling in which the court 
ordered the City of Los Angeles to follow the California Environmental 
Quality Act and to reconsider the methane mitigation measures built into 
the original buildings. Thus far, critics have successfully blocked the 
construction of a new school in a methane-susceptible area.

Much of the methane debate centers upon whether the source is natural - 
much of West Los Angeles is an old oilfield - or the result of leakage 
from Southern California Gas Company's underground gas storage 
reservoir. In my view, the more important question is whether the 
mitigation systems of plastic lining and ventilation built into the new 
buildings are adequately containing the methane. KNBC and the Grassroots 
Coalition have demonstrated mitigation system failures, in which methane 
vapors intruded into at least some of the Playa Vista buildings.

While the debate over methane intrusion has been going on for some time, 
little public attention has been paid to the toxic groundwater 
contamination typical of aerospace production and airfields. The shallow 
aquifer under parts of the property contains TCE (trichloroethylene), 
vinyl chloride, and BETX (benzene, ethylbenzene, toluene, and xylene) in 
the thousands of parts per billion. The contaminant of greatest concern 
appears to be vinyl chloride, formed by the apparent biodegradation of TCE .

The Playa Vista site has been undergoing remediation for more than a 
decade, under the supervision of the LARWQCB. The developer has employed 
innovative in situ technologies, and the Water Board has designated the 
state drinking water standards as long-term remediation goals. However, 
it has also accepted, with minor qualifications, less protective, 
site-specific Health-Based Remediation Goals (HBRGs) proposed by the 
developer's consultant and reviewed by California's Office of 
Environmental Health Hazard Assessment. The HBRGs supposedly take into 
account the vapor intrusion pathway, the potential migration of volatile 
compounds from the subsurface into overlying structures.

Each segment of the property must meet those standards before 
development may occur. That is, construction is permitted when soil, 
groundwater, and soil gas measurements of vinyl chloride and other 
contaminants falls below the HBRGs, even while cleanup systems continue 
to pursue the legally mandated groundwater goals. Furthermore, the 
developer has agreed to use the HBRGs created for residential - that is, 
unrestricted - use, and to build mitigation into its structures. The 
Water Board would require institutional controls - legally binding 
activity and use limitations - if residential HBRGs are not met.

There are several vinyl chloride hot spots on the property. The highest 
concentrations - in the thousands of parts per billion - are in the 
"Campus Area," the area including the historic hangars. According to 
Water Board officials, no construction has occurred directly over those 
hot spots. According to McPherson, there is still an active proposal to 
construct a new school on or near the old Hughes fire training burn pit, 
but that - under California's school review law - is being evaluated by 
another agency, the Department of Toxic Substances Control.

In my view, the application of a second set of remediation goals to 
approve construction over the toxic hot spots is innovative, and on its 
surface, a good way to balance the objectives of property use and 
environmental protection. However, the HBRGs for vinyl chloride are 
surprisingly high (weak). The residential-scenario vinyl chloride 
groundwater HBRG is 26.5 parts per billion (ppb). The soil-gas HBRG for 
vinyl chloride is 3,710 micrograms per cubic meter. At these levels, I 
believe, unacceptable concentrations of vinyl chloride could migrate 
into overlying structures.

Conceivably, the vapor mitigation measures being designed into new 
buildings could protect occupants, even from high subsurface levels of 
vinyl chloride and other compounds. But vapor membranes can be 
perforated during construction or by subsequent human or natural 
activity. Because they have been employed only in recent years, we don't 
know how long they will remain effective. Furthermore, experience 
elsewhere suggests that it difficult to predict vapor intrusion from 
groundwater and external soil gas concentrations, both because of 
geospatial heterogeneity in the soil and the fact that buildings tend to 
increase the forces that pull up toxic vapors.

Therefore, in my opinion, the only way to ensure that the occupants of 
buildings at Playa Vista are not exposed to unacceptable levels of 
volatile organic compounds is to periodically test the indoor air in 
those buildings until the residual contamination beneath them is reduced 
to legal standards - not the HBRGs. Existing buildings, in which artists 
currently work, should be sampled as well. It may be that 
methane-monitoring equipment can demonstrate that no vapor intrusion is 
occurring, but only in those areas with high methane levels. Where vapor 
barriers fail, additional mitigation, such as active subslab ventilation 
or positive air pressure systems, should be required.

The intrusion of toxic vapors into homes and other structures is not the 
only issue at Playa Vista. It's not the reason that a broad coalition of 
activists continues to oppose the project. But it is an issue that has 
escaped public notice, and I'm concerned, without more stringent HBRGs 
and recurring indoor air sampling, that residents and other building 
occupants may be exposed to unsafe levels of vinyl chloride and other 
toxic compounds.

-- 
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
http://www.cpeo.org