BAKERSFIELD, Calif. (AP) — Crews have sealed 13 oil wells in California’s San Joaquin Valley that leaked methane, some reportedly at levels that risk an explosion, a state official said Friday.
“The wellheads have been repaired,” and there were no readings of methane emissions in a nearby neighborhood, said Uduak-Joe Ntuk, head of the California Geologic Energy Management, the conservation department division that oversees wells.
Inspectors last week discovered that six idle oil wells near Bakersfield homes had been leaking methane, the conservation department announced earlier this week. Seven additional leaking wells were later discovered for a total of 13, the department confirmed Friday.
The department didn’t say how much methane had leaked but at least three of the original six wells found to be leaking had methane concentrations of 50,000 parts per million in the air surrounding them, according to a report from the state. Methane is potentially explosive at air concentrations of 50,000 ppm, according to federal guidelines.
Residents and environmentalists in the region first became concerned when they were alerted by Clark Williams-Derry, an energy analyst, that two wells were hissing within a few hundred feet of homes. He was visiting the area on May 10 with a French documentary crew that’s working on a film about cleaning up oil and gas infrastructure around the globe.
“One of them was leaking; it was making an audible hiss,” Williams-Derry told The Associated Press. “And I was like ‘What the hell is going on?’ I thought these things were supposed to be essentially sealed.”
CalGEM had earlier said there was no reason to alert the public of the leaks, but advocates in the region disagreed. In the days following discovery of the first leaks, Cesar Aguirre, senior community organizer for the Central California Environmental Justice Network, canvassed the neighborhood surrounding the wells to notify residents.
Aguirre said he was warning residents about the potential of an explosion or fire in their community, but also about other possible pollution, like acute levels of ozone or smog, that might be forming around the leaking wells.
David J.X. González, lead author on a recent study on the distribution of abandoned wells in urban areas, echoed some of Aguirre’s concerns and said earlier this week that the leaks were an “urgent public health issue.”
“Researchers have found that methane emissions from abandoned wells, which are disproportionately located in Black and Latinx neighborhoods, likely means other air toxics are being emitted too, which can cause birth defects, neurological damage, impaired hearing, and some cancers,” he said in a statement.
At an online community meeting Friday, air quality and public health officials said they had sampled the air and were assessing the risk to public health.
Ntuk also was questioned about the risks of explosions from a buildup of methane underground.
Ntuk said gauges have been placed on the idled wells to monitor underground pressure, although he added that there is little chance of a well blowout because the oil field is old and low-pressured.
Ntuk said CalGEM planned to eventually make sure the wells weren’t just capped but declared abandoned and entirely plugged with cement. The idled wells, which sit in a vast, century-old oil field, were only inspected recently, he added.
Ntuk said his department has about 100 inspectors to handle 37,000 idled oil wells around the state.
But getting well owners to deal with them or declare them abandoned can be challenging, he added.
“Unfortunately, we have bankrupt operators; we have operators who have been gone for decades,” he said.