On Monday, a Los Angeles Superior Court Judge approved a $119.5 million settlement between Southern California Gas (SoCalGas) and the California Air Resources Board (CARB). SoCalGas was responsible for the Aliso Canyon Natural Gas Storage Facility when one of the 115 storage wells at the site started leaking methane dramatically.

Stanching the leak took nearly five months, and in that time 109,000 metric tons of methane was spewed into the atmosphere.

Methane is an extremely potent greenhouse gas, capable of trapping more heat in the atmosphere than carbon dioxide, although methane is shorter-lived. In addition to the headaches and nosebleeds suffered by the people living in the nearby Porter Ranch neighborhood, researchers later concluded that the leak had doubled the methane emissions rate of the whole Los Angeles Basin.

According to CARB, $26.5 million of the $119.5 million that SoCalGas is required to pay will go toward providing loans to build methane digesters at 12 dairy farms in California’s San Joaquin Valley. A company called California Bioenergy will use these loans to construct “conditioning facilities and pipelines to allow the natural gas pipeline system to receive biomethane generated by cattle in the valley’s dairies,” a CARB press release said. (“Dairy manure is responsible for about 25 percent of the state’s total methane emissions,” CARB noted.)

The loans will be paid back into two funds that will support other air-cleaning projects in Southern California. SoCalGas will apparently not be able to recoup the principal or interest, as the money is meant to remove the same amount of methane from the atmosphere that was released by Aliso Canyon between 2015 and 2016. CARB expects that “full mitigation” of the effects of the leak will be completed by 2031.

The rest of the settlement paid by SoCalGas will be divvied up between environmental project funds and penalty payments managed by and collected on behalf of the City of Los Angeles, Los Angeles County, and the California Attorney General’s Office. $19 million will be used to cover leak response costs and litigation costs that the public institutions incurred, and an additional $7.6 million will be “held in reserve for mitigation, if needed,” CARB said.

https://arstechnica.com/?p=1464289