The hugest methane leak in US history, at the Aliso Canyon natural gas storage field near Porter Ranch, which led to the relocation of thousands this past fall, has been plugged for months, but the effects of that leak, and the precautions to make sure it doesn't happen again here, are still playing out.
Post-leak, the Southern California Gas Company was banned from putting any gas in or taking any out of the field, which is their largest. In order to get the site back to normal operations, the gas company has been ordered to test the wells and each individual well has to pass the tests or be shut down.
As of Friday, when the company filed a formal report on the field with regulators, 31 of the 114 wells at the Aliso Canyon facility have been taken out of service, says KPCC.
Reasons for taking the wells out of commission range from their failure to pass tests to simply their advanced age: many of the wells now offline date back to the 1940s, and the one that notoriously leaked dated to 1953.
SoCal Gas says that it's put 101 wells through the first "basic" battery of tests, and that 58 of those passed, obtaining approval from the Division of Oil, Gas and Geothermal Resources. So far six of those 58 have gone on to the second, more rigorous round of testing, and of those six, one so far has received the next tier of approval.
SoCal Gas has said that they think they can have enough of their wells tested and approved by August to get the field online again in time to avoid potential summer blackouts.