Panel Urges Detectors at Gas Leak Site : Methane: City task force recommends that a requirement for the sensors and other safety measures be rigidly enforced in a 400-block risk zone near the Farmers Market.

A city task force has found that a requirement for gas detectors to be installed in homes and commercial structures in the methane risk zone near the Farmers Market is being widely ignored.

The detectors proved themselves as recently as one year ago, when a portable device warned that a dangerous concentration of gas was building up in a store across the street from the spot where a methane explosion and fire injured more than 20 people on March 24, 1985.

To date, 35 of the sensors have been installed in a 400-block area that was declared to be a potentially dangerous area after the 1985 fire, the task force’s chairman, city geologist J. W. Cobarrubias, said Tuesday.

Because city law requires sensors whenever a home or building with a basement that could trap methane changes hands, the actual number should have been much higher, he said.

In the report, which is awaiting action by the Los Angeles City Council, the task force said that wells and ditches should be dug to provide a safe exit for any further gas buildups in the porous soil beneath the corner of 3rd Street and Ogden Drive.

It also called for commercial and industrial buildings to be equipped with ventilation systems that can change the air in a room as soon as a dangerous accumulation of the odorless and colorless gas is noticed by the mechanical sensors.

The task force recommended that a special priority be given to a several-block area close to the Ross Dress for Less store, where the 1985 blast occurred, and that the Fire Department and the Department of Building and Safety be authorized to devote time and money to inspections and other measures to prevent additional explosions.

In this priority area, the task force recommended that a team of inspectors be hired to make a systematic survey of existing apartment houses and commercial and industrial buildings to make sure that the required gas detection and venting systems are in place.

The report also recommended that technical surveys be conducted to identify other potentially dangerous locations in the Fairfax District.

Cost of the surveys was estimated at $75,000, but installation of $133,600 worth of relief wells and collector trenches probably would cost the city no more that $4,600 because state funds would pay for the rest, the report said. The task force recommendations must first be considered by the City Council’s Finance and Revenue Committee, but a spokeswoman for Councilman Zev Yaroslavsky, chairman of the panel, said that it has not yet been scheduled for discussion.

Cobarrubias said Tuesday that the group devoted “a lot of time” to the question of where the methane comes from, but did not reach a conclusion.

One study, funded by a grant from the Gas Research Institute, concluded that the methane seeped up from deposits in an oil field thousands of feet below the surface. But other research paid for by the state of California found that similar gases could be produced by microbes near the surface.

The debate most likely will end up in the courts, where victims of the 1985 explosion and fire in the Ross store are suing McFarland Energy Inc., an oil company that operates 42 wells under the area from a compound behind the Farmers Market.

Cobarrubias declined to take sides in the matter, saying, “It’s a wonderfully nice academic exercise, (but) whichever gas it is, it’s going to vent the same. I’m just there to vent the gas.”

The latest methane incident took place on Feb. 7, 1989, when seepage was so strong that a fountain of gas, water and mud burst through the pavement near 3rd Street and Ogden Drive, outside the Gilmore Bank on the Farmers Market property. The same day, a sensor in the basement of a K mart store across the street detected a dangerous methane buildup.

If approved by the City Council, three wells would be dug near the corner in the hope of providing a safe vent for the gas. Two would be on the Farmers Market property--one in front of the Kiddyland game room and another outside the Gilmore Bank. The third would be in front of K mart.

The wells would extend through a clay bank 42 feet down that is believed to be the barrier that allows gas to gather at dangerously high concentrations before it slips up to the surface.

Although the City Council required in 1986 that gas detectors be installed in nearby homes and buildings with basements where methane could collect, the Building and Safety Department has no way to check on compliance, Cobarrubias said.

“The main line of defense is recognition of (gas) incursion by use of these detectors,” he said. In the 1989 incident, “there’s no telling how long it would have taken people to notice it.”

In that case, workers at K mart saw the alarm flashing when they came in shortly after 6 a.m. Nobody was hurt, but the area was closed off for two days.

The nearby Hancock Park Elementary School stayed open despite the alert. Principal Brenda Steppes said inspectors from the Los Angeles Unified School District take methane readings on the school grounds almost every day and found none that day.

Seven sensors distributed throughout the school are hooked up to an alarm system, she said. Although the monitors have noted some minor methane buildups after earthquakes, they all dissipated quickly, she said.