SoCalGas: Newly Discovered Release Of Methane At Aliso Canyon Near Porter Ranch Poses No Health Risks

PORTER RANCH (CBSLA.com) — The newly discovered methane seeping out of the soil near a gas well that was plugged earlier this year following a four-month leak in the Aliso Canyon Storage Facility poses no health risks to Porter Ranch residents, according to a Southern California Gas Company spokesman.

Using Infra-red technology, inspectors discovered "a very slight and intermittent observation of methane" at the SS-25 wellhead of the Aliso Canyon Storage Facility at 7:45 a.m. Saturday, according to spokesman Sergio Jimenez.

"We believe this is a continuation of off-gassing from the soil that has previously been observed at the site," Jimenez said. "This recent off gassing of the soil coincides with the recent intense rain events at the site and is not believed to pose a present or potential hazard to human health safety or the environment."

"No anomalies have been detected through other monitoring techniques, including the fence line monitoring system and visual inspections, and there is no discernible odor at the site," he said.

The utility's spokesman, Chris Gilbride, likened the amount of the recent incident to "the wisping vapors of a single table candle," and said monitoring indicates that the slight methane releases are contained to the well site, and that levels in the community remain normal.

According to Gilbride, the recent rain storms triggered the slight release of natural gas that was previously trapped in the soil following last year's leak.

When the well was sealed in February, "some amount of residual methane trapped in the soil is expected to seep out of the ground around the leaking well after the well is successfully controlled and then sealed," he said.

The 2015 methane leak, which scientists called the largest in U.S. history, displaced at least 7,000 Porter Ranch area residents for months.

That leak, which spewed 109,000 metric tons of methane, at the 3,600-acre underground storage facility was detected on Oct. 23, 2015 and capped in early February.

SoCalGas has asked for state approval to resume natural gas injections at the site, but neighbors and environmental activists want it shut down permanently.