California utility regulators have ordered the owners of all underground gas storage fields in the state to undergo immediate checks for leaks.
The directive from the state Public Utilities Commission accompanies an order by environmental regulators requiring Southern California Gas Co. to turn over all records it has on its gas storage field in Aliso Canyon, where a well has been leaking massive amounts of methane since late October. Noxious fumes from that leak have forced thousands of downwind residents in Porter Ranch and other communities from their homes.
The letters bear Tuesday's date, though they were not publicly posted by the commission until Wednesday.
"We are taking additional safety assurance measures and directing the operators to demonstrate that their storage facilities are safe by conducting this special leak survey," said commission spokeswoman Terrie Prosper.
Environmental regulators give Southern California Gas until Monday to turn over all records and documents the company has on its Aliso Canyon gas storage project.
In particular, the Department of Conservation's gas and oil division wants copies of all records regarding the subsurface safety valve believed to have been installed on the well in 1979, and a record of its history of leaks. The agency seeks details on how the well was operated, including whether the company pumped gas through both the well's inner tubing as well as an outer, unprotected steel casing.
The gas company did not respond to questions about the new state requirements, but released its own statement disputing reports it had agreed to shut down and plug the 18 oldest wells at Aliso Canyon. The storage project is based on an old oil field and many of the wells there date to the 1940s.
The gas company said it has instead temporarily installed plugs on those wells so that they can be inspected.