Porter Ranch: California utility regulators want all underground gas wells checked for leaks

The natural gas leak near Porter Ranch in the San Fernando Valley has prompted California state utilities regulators to order all similar gas wells to be checked for leaks.

The California Public Utilities Commission, which oversees investor-owned utilities, gave the operators of 14 underground gas storage projects until 3 p.m. Wednesday to submit their plans to survey wells for leaks.

In a separate order focused on the Porter Ranch leak, the state Public Utilities Commission has ordered the Southern California Gas Company to deliver up just about every scrap of data it has about the leaking natural gas well known as Standard Sesnon 25.

The data dump is going to be huge, partly because the well dates back to 1953. It was originally drilled to extract oil from 8,900 feet underground, but its function was changed in the early '70s to inject and withdraw natural gas to and from an underground rock formation.

The PUC wants specifics — like whether the company replaced a safety valve in 1979. It wants to know why well records show wide temperature changes deep in the well in 1989. And whether the 1994 Northridge earthquake damaged the well. The PUC also wants SoCal Gas to say if it was up-to-date performing mandatory mechanical integrity tests on the well.

PUC spokesman Christopher Chow said the agency was analyzing the reliability of natural gas fuel supplies if Aliso Canyon is not operational next winter — or beyond.

"We are doing this so that we are aware of all the possible options to assure reliability, and in accordance with the governor’s proclamation that directed state agencies to report on the long-term viability of all storage facilities in the state, including Aliso Canyon," Chow said.

Environmentalists and nearby residents have repeatedly demanded the gas field be permanently shut down, and SoCal Gas counters those arguments by saying that the underground reservoir backstops the energy supply for electrical power providers in Los Angeles and Orange counties.

Late Wednesday, Southern California Gas Company announced it would temporarily shut down 18 wells at its natural gas storage field near Porter Ranch. They are about the same age as the 1950s-era well that's been leaking massive amounts of methane into the atmosphere, forcing thousands of nearby families to relocate.

SoCal Gas says the 18 wells will be first in line for inspections and could be put back into service if they are in good condition.

Also, SoCal Gas had been under orders from various regulators to remove as much gas from the underground storage field as fast as it could safely do so to reduce the pressure forcing methane out of the ruptured well.

But that activity halted on Wednesday. SoCal Gas spokeswoman Kristine Lloyd said the halt was to comply with a Public Utilities Commission directive.

The PUC on Jan. 21 ordered SoCal Gas to reduce the amount of "working gas," that is, the amount that is available for sale to customers, to 15 billion cubic feet. That is far below the normal working gas capacity of about 86 billion cubic feet the area can store. The storage area maintains an additional 86 billion cubic feet of "cushion gas" underground which keeps the pressure high enough to allow the injection and production wells to function.

Congressman Brad Sherman, who represents many of those residents, says the gas company has become too reliant on old wells like those dotting its Aliso Canyon gas storage field.

"I think So Cal Gas has a difficult time proving that keeping these wells active as pipes to inject and remove natural gas is a safe thing to do," Sherman said.

Public Utilities Commission request

Public Utilities Commission Orders