The Science of Making Belmont Safe

In fact, several engineers said that the anticipated Belmont fix was overkill, noting that they have been installing "lesser" systems all over the L.A. basin without incident. But at Belmont, it would be hard to justify anything but the strictest safety standards.

The quality of these systems has improved since the mid-1970s, when state engineers and contractors were installing methane mitigation for the first time. The process was also new to city and fire-department inspectors who had to sign off on the work after the Fairfax explosion. There is no degree program in vapor-barrier science.

Inevitably, some things went wrong. A faulty barrier system underneath an office building on Wilshire Boulevard has created an ongoing potentially hazardous nuisance.

"Oil was oozing through the walls, and the building had methane sensors that were continually going off," says Louis Pandolfi, whose firm GeoScience Analytical monitors the building for methane accumulation. Even today, he says, "you’ll just see the oil coming through the walls of the subterranean walls. Gas is in the building at all times in the lower levels." As a result, a venting fan must run 24 hours a day, and the encroaching oil must be removed.

Litigation over the failed system eventually led to a $4 million settlement paid to the building’s owners by contractors, subcontractors or their insurers. No one admitted any wrongdoing.

At Belmont, a Hoag-like extraction system would run about $10 million to design and install, according to Pandolfi. Another methane specialist, John Sepich, says a simpler pipe-and-barrier setup would suffice, at a cost of about $2 million.

Sepich designed the barrier system under the Central Library, among other places, as well as the original safety system intended for Belmont. Belmont opponents criticize Sepich because his final design did not protect all of the buildings at Belmont. Critics regard him as overly cost-conscious and more "pro-contractor" than "pro-safety." Sepich vigorously disputes this contention, and insists that the dangers at Belmont have been considerably overrated. The entire site does not need protection, he says, because gas was not detected everywhere and "when you don’t find gas you don’t need a membrane."

District officials incline toward a more conservative view. Despite the added expense, any safety system at Belmont is likely to include all the buildings and the playing fields as well.

Last month, the school district formally invited contractors to submit plans for finishing Belmont. These plans would have to include a safety fix. For Belmont, it’s unlikely that a "passive" system — like the one used by Tofani’s company in Riverside — would be approved by oversight agencies. Instead, the state Department of Toxic Substances Control has indicated its preference for an "active" venting system, one that uses suction to pull methane into its pipes.

A safety system at Belmont also must address the school’s playing fields. In open air, methane poses no danger, but even minuscule amounts of hydrogen sulfide pose health risks. One way to deal with hydrogen sulfide is to install a layer of sand or gravel to disperse the gas to harmless concentrations. This strategy can be combined with laying down venting pipes, which lead into gas-collection tanks.

In Riverside, back underneath the March sky, Fonseca is pushing his crew to hurry up; it’ll get dark soon. "I don’t finish, I don’t go home," he says.

California’s rapid growth is beginning to make scenes like this commonplace. Any open land, it seems, is game for building. At the very least, the boom isn’t going to stop in its tracks because of oil deposits or cow feces — a message brought home by the vista at the Riverside County construction site. The blocks all around are filled with houses that have tell-tale black piping poking above the roofs.

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