LOS ANGELES, Feb. 12 (UPI) -- Southern California Gas Co. said it temporarily controlled the flow of gas leaking for a storage facility near Los Angeles roughly four months after it began.
"We have temporarily controlled the natural gas flow from the leaking well and begun the process of sealing the well and permanently stopping the leak," Jimmie Cho, SoCalGas senior vice president of gas operations, said in a statement.
SoCalGas workers started drilling a relief well to stem the leak in late January. Methane, a greenhouse gas more potent than carbon dioxide, was leaking from the site and other gases associated with the mix may contain chemicals associated with cancer risks.
The utility company said it still needs to inject cement into the well to seal it permanently, and that could take several more days.
"The company also is continuing its preparations to drill a back-up relief well as a precautionary measure and will continue these efforts at least until the leak has been stopped permanently, the timing of which has not been determined yet," it said in a statement.
California Gov. Jerry Brown declared a state of emergency "given the prolonged and continuing duration of the so-called Aliso Canyon gas leak" in early January. State authorities said the leak appeared to be the result of damage to well infrastructure located about 500 feet underground.
Residents who were forced to move as a result of the non-toxic methane leak were notified the relocation program was winding down. Barring some exceptions, SoCalGas said residents that moved to short-term housing like hotels have eight days to return home and others in rental housing have until lease terms expire.