Environment & Science

SoCal Gas won't say if it will comply with state's extensive methane gas leak mitigation plan

Natural gas spewed from a ruptured well at SoCal Gas' Aliso Canyon Storage Facility near Porter Ranch for over four months.
Natural gas spewed from a ruptured well at SoCal Gas' Aliso Canyon Storage Facility near Porter Ranch for over four months.
Maya Sugarman/KPCC

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The state is calling for Southern California Gas Company to offset the methane that its broken storage well near Porter Ranch released over four months. But the gas company won't say if it will comply with the state's plan or pursue a less expensive alternative that would capture less greenhouse gas.

"We're looking to get going on this," said Dave Clegern, spokesman for the state Air Resources Board. The ARB wrote the plan to offset environmental damage from nearly 100,000 metric tons of methane that escaped the ruptured gas well at SoCal Gas's Aliso Canyon Natural Gas Storage Facility.

"We expect them to follow through on their commitment to the governor," Clegern said.

SoCal Gas spokesman Chris Gilbride said the company plans to follow through on its commitment to mitigate the environmental damage. But it didn't say how. 

One option is for SoCal Gas to capture an amount of methane from other polluters, like landfills and dairy farms, equal to the amount the broken well released to the atmosphere. Or the company could capture the carbon equivalent, but the company and state disagree over how that carbon equivalent would be measured.

The Aliso Canyon natural gas leak near Porter Ranch accounted for a large portion of California's methane emissions over the four months the leak was active, adding about 20 percent to the state's total methane count.
The Aliso Canyon natural gas leak near Porter Ranch accounted for a large portion of California's methane emissions over the four months the leak was active, adding about 20 percent to the state's total methane count.
California Air Resources Board

Gilbride declined to state whether SoCal Gas would base its methane and greenhouse gas capture program on a 20-year or 100-year damage scenario.

The gas company prefers the 100-year version, which is predicated on research that a molecule of methane traps 28 times more heat in the atmosphere over 100 years than a molecule of carbon dioxide.

The ARB plan, approved Friday by Gov. Jerry Brown, calls for measuring the damage from the gas leak over 20 years, because methane does most of its damage in the atmosphere in its first dozen years, then dissipates. The 20-year global warming potential scenario says that a molecule of methane has 84 times the heat-trapping power of a molecule of carbon dioxide.

The 100-year version that SoCal Gas prefers would capture less than one-third of the greenhouse gases called for in the 20-year state plan and cost tens of millions of dollars less to accomplish.
 
"There is still much work ahead, but we stand prepared to take the necessary actions to deliver on our commitments," Gilbride wrote in an email statement.

The state plan is voluntary — for now. But the ARB is suing SoCal Gas, and the plan could be made mandatory in a future settlement.