Sixteen weeks after high levels of methane gas were detected leaking from a storage facility owned by Southern California Gas Company (SoCal Gas - the nation's largest natural gas distribution utility) in Aliso Canyon, the California Department of Conservation has declared that the leak has been permanent sealed with concrete.

The South Coast Air Quality Management District and the California Air Resources Board will continue to monitor the air in the coming weeks, looking at the levels of methane, mercaptans, benzene and hydrogen sulfide. Meanwhile, no more gas will be injected into the underground reservoir until all of the 114 remaining wells are inspected using new standards.

Rep. Brad Sherman (D-Porter Ranch) called for "tough new regulations" for the other 114 injection wells at the 3,600-acre underground natural gas storage facility, which is among the nation's largest. The gas company has said that many of those wells are aging, corroded and mechanically damaged.

6500 area residents who were forced to leave their homes in the wake of the leak will now be able to return. SoCal Gas will reimburse these residents for expenses incurred through relocation and the company expressed its readiness to work with state regulators in enhancing the security of the remaining wells in the Aliso Canyon storage facility.