A plume of TCE runs beneath neighborhoods and businesses in El Cajon. It can turn into a gas, filter up through the ground and collect indoors in unventilated spaces.
A plume of TCE runs beneath neighborhoods and businesses in El Cajon. It can turn into a gas, filter up through the ground and collect indoors in unventilated spaces.

[one_third][/one_third]There is no doubt now that some residents of two mobile home parks in El Cajon have been exposed to toxic gas seeping into their homes from a plume of contaminated groundwater. Recent air testing and a newly released health risk study make that clear.

Residents of the Starlight Mobile Home Park and Greenfield Mobile Estates will have their first chance this week to question public officials since the testing of 17 initial homes.

“Anybody who is above the plume, who wants it, should have sampling conducted right away,” said Lenny Siegel with the Center for Public Environmental Oversight in Mountain View, Calif.  Siegel has worked on more than 200 contaminated sites. His organization consults with communities that live above toxic plumes.

An environmental chemist and vapor expert involved in past testing at Magnolia Elementary School, which is also next door to the industrial site where chemicals leaked, was surprised that more has not been done to remedy the pollution by now.

“They had enough data, they should have been sampling both the school and the surrounding neighborhood earlier,” said Blayne Hartman, with Hartman Environmental Geoscience. If the Environmental Protection Agency were overseeing the site, he said, it would want testing in any home where the concentration underground is 5 micrograms trichloroethylene per liter of groundwater or more.

“Someone is doing a heck of a job of blocking the investigation of what should be going on,” he said of the delay.

It has long been known that contamination stemming from years of disposal of dangerous chemicals at a former El Cajon aerospace manufacturing firm reached shallow groundwater and flowed under the neighborhood. Some of the chemicals have a propensity to leave the water and vaporize up through the soil.

A representative for Ametek, Dr. Mary McDaniel, an environmental medicine physician, said a proposal for additional testing “does align closely” with a practice of testing any home that sits atop the groundwater plume wherever the plume contains more than 5 micrograms per liter of trichloroethylene. Ametek is one of the former aerospace manufacturers and the legally responsible party.

That would include homes even beyond the plume map inewsource published last year.

But a draft copy of a plan for next steps proposes testing only 21 more homes, and basing any further home testing on results from those. A state official with the Department of Toxic Substances Control, which is taking over as a lead agency in addressing the now 1.3-mile toxic plume, stressed that the document is preliminary. 

The contaminant in the plume is the chemical trichloroethylene (TCE), which has been linked to serious health conditions. When pregnant women are exposed to trichloroethylene during their first trimester, research indicates it can cause a fetal heart defect. The chemical is also linked to sexual and reproductive issues in men, as well as kidney cancer.

Fourteen years have passed since state toxics officials told the companies responsible for polluted land and water at the manufacturing site to make sure workers were not being exposed to fumes. Twenty years have passed since state water officials found that soil soaked with solvent was leaching into groundwater. Thirty years have passed since the company Ametek paid to dig up and haul off the most highly polluted soil from a hole in the ground at the site.

But in all those years, no one insisted on protection for the mobile home residents who live next door.

The new 1,700 page health risk study, posted by the San Diego Regional Water Quality Control Board, shows test results for 17 homes. Some had multiple samples taken. Five homes had at least one air test with results above the Environmental Protection Agency’s accelerated response action level for trichloroethylene, or TCE. Two of the five were even higher, above the urgent response action level. That means that immediate action such as air filtration or relocation is recommended. One home tested five times the urgent level. inewsource first reported on the home testing last month.

Siegel and Hartman emphasized that TCE levels can vary in a building throughout the day and from one day to the next.

The technicians who performed the tests also probed the soil for chemicals. In some spots – inside the boundaries of the mobile home parks – they found amounts of TCE in shallow soil that translate to cancer risk much higher than the risk often considered acceptable.

Water board officials said the fact that solvent gas is penetrating homes came as a surprise. Siegel blamed that surprise on an institutional tendency to ignore communities adjacent to pollution sources.

“The water board really focuses on the source sites, the former industrial sites,” he said. “No one is looking at the adjacent neighborhood.”

The facts in this case seem to support that. The Department of Toxic Substances Control has known about the site for years, and has been actively involved in making sure Magnolia Elementary School is safe.  But the agency has not insisted on testing of the homes. Asked why, Russ Edmondson, an information officer, pointed to the water board as the lead agency.

TCE is a powerful grease cutter and the most prevalent chemical in the El Cajon plume. Across the country, it is the primary pollutant at thousands of tainted groundwater sites.

The new health risk assessment also reviewed results from soil tests at the Alder Woods Condominiums, west of the mobile parks, and about 1500 feet west of the former aerospace facility. There is measurable solvent there as well, as well as several other chemicals. But the TCE levels there are generally acceptable, the report said. They vary enough that more testing might be recommended.

Going forward, Siegel said, El Cajon residents will probably have to organize if they want action. He offered to come to San Diego to provide a community primer on toxic plumes.

“The number one factor in ensuring your community gets protected is the level of community engagement in that community, whether it is the city council or a community organization or an environmental group,” he said.

The community meeting is at 6 p.m. at Magnolia Elementary School on June 14.

Ingrid Lobet is a reporter at inewsource specializing in the environment. To contact her with tips, suggestions or corrections, please email ingridlobet@inewsource.org.