Shoppers meandering about Farmers Market in Los Angeles Fairfax District can search for organic tomatoes while enjoying this throwback to earlier times when produce was always fresh off the farm, cities were smaller, and when there was no such thing as a "High Potential Methane Zone."
High-pressure surges of methane, a flammable "natural gas" associated with oil fields, twice have shut down stretches of Third Street: once in 1985, after a gas explosion in a Ross Dress For Less store, and again in 1989, after a fountain of gas, water and mud burst through the ground in front of a nearby bank. Methane, says Fire Department Inspector Lloyd Fukuda, "blew out a whole plug of mud and continued to blow for quite a while."
Methane percolates upward through the underground of Southern California from the Puente Hills to Newport Beach: Its the gas that led planners to change the route of the citys subway, to avoid tunneling through the methane zones along Wilshire Boulevard. Its presence also is cited as an unacceptable hazard at the half-finished Belmont Learning Complex downtown. But comparing to the situation at Belmont is a thorny endeavor.
For one thing, Fairfax contains higher concentrations of methane over a larger area. And the Ross incident occurred in a building with no protection against methane, and before the dangers of methane were even seriously examined locally. Neither condition would apply to Belmont. As it turns out, L.A. Unified operates an elementary school across the street from the Fairfax explosion. That school, Hancock Park Elementary, has methane alarms, and a crude system of fans to blow stagnant air out from underneath its raised foundation, but none of the higher-tech, more modern safeguards envisioned for Belmont. The Belmont site does, however, have one real problem that much of Fairfax does not. Analysts documented two places on the Belmont site where underground soil vapors contained high levels of hydrogen sulfide, a toxic gas which would have to be addressed.
Fairfaxs methane originates in part from crude oil deposits that begin about 600 feet underground. Once called the Salt Lake Oil Field, today its a long-established neighborhood of shops and homes.
A city task-force investigation after the Ross incident determined the immediate source of the exploding gas was a methane bubble 40 feet below ground level, created by subsurface bacteria munching on decaying biomass (including oil). A lawsuit over the explosion targeted McFarland Energy, which drilled slanting wells from its property into oil reserves under adjacent parcels. The lawsuit blamed McFarland for releasing methane gas that drifted upward through abandoned, improperly sealed oil wells. McFarlands experts countered that the methane was caused by natural conditions unrelated to its drilling activities. McFarland settled the suit without admitting any guilt.
The second pressurized gas incident may have been indirectly related to the first, as a pressure-relief well drilled in the Ross parking lot was neglected and, by 1989, was blocked with silt.
Regardless, Fairfax remains a methane-saturated area with the potential for gas explosions. Though methane isnt a problem when it vents directly into open air, concrete foundations and asphalt streets impede its natural flow into the atmosphere. Methane then accumulates underground instead and can seep into basements, building up to an explosive threshold.
In the wake of the Ross incident, the city designated 400 blocks of Los Angeles as a "Potential Methane Zone," an area roughly bounded by Olympic Boulevard on the south, Rossmore Avenue on the east, Oakwood Avenue on the north and San Vicente Boulevard on the west. Inside of that in a swath that includes the Park LaBrea apartments, Hancock Park Elementary, Wilshire Boulevards grand museum row and Farmers Market is the "High Potential Methane Zone." (See map.)
Those who consider Belmont a deathtrap would do well to avoid the Fairfax area entirely. The methane task force, for example, called for the installation of two collection trenches and three new relief wells around Third Street and Ogden Drive, but they were never installed. Business owners dug wells and trenches on their own initiative, but no agency exists to monitor their effectiveness. And though City Code requires all buildings in the area, new and old, to have a methane detector, this provision is not enforced in existing structures. "We dont track that," acknowledges Department of Building and Safety spokesman Bob Steinbach.
Concern over lack of compliance with the citys minimal methane safeguards was raised as far back as 1990 by Joe Cobarrubias, the Building and Safety official who helped lead two methane task forces for the city. Today, inspections for compliance occur most often when the city issues permits for renovation or a building changes owners.
More is required of new construction. Building contractors must submit actual mitigation plans for dealing with methane. In apartment buildings, for example, the City Code requires a vent system capable of pumping in four changes of air per hour. All new buildings, including single-family homes, also must have a membrane under the building to help keep methane out.
These methane systems come in all sorts, sizes and degrees of quality; the Fairfax episode effectively jump-started a cottage industry in methane control, where the desire for inexpensive and pragmatic solutions far out-paced real expertise.
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Something out there seems to be working; large portions of the city have not, in fact, burst into methane-fueled flames. Still, its impossible to say whether the credit goes to applied science or natural forces whose dangers might have been overestimated. Fire Department calls relating to methane have substantially declined since the early 1990s. Even then, says the Fire Departments Fukuda, most calls were false alarms, triggered mostly by people using aerosol sprays. Hollywood studios were especially prone, he says. "It just so happened that some of the sensors were placed in dressing rooms. They were using hair spray and hair spray would set the alarms off."
Methane did force a six-month closure of the Wells Fargo bank at the corner of Beverly Boulevard and Fairfax Avenue in November 1990. But the gas source was traced to leaky underground storage tanks at an Arco station next door.
Methane in Fairfax remains an ever-present threat, even though the spell of methane anxiety has migrated onward to Belmont.