California’s ARB sets out mitigation plan for SoCalGas over Aliso Canyon methane leak

Published 00:04 on March 21, 2016  /  Last updated at 00:52 on March 21, 2016  /  Americas, US  /  No Comments

California clean air regulator ARB has published recommendations over how natural gas provider Southern California Gas (SoCalGas) should mitigate the estimated 8 million tonnes of CO2e released during the four-month Aliso Canyon methane leak.

California clean air regulator ARB has published recommendations over how natural gas provider Southern California Gas (SoCalGas) should mitigate the estimated 8 million tonnes of CO2e released during the four-month Aliso Canyon methane leak.

In a draft document published late on Friday, ARB estimated that the roughly 100,000 metric tonnes of methane leaked from a SoCalGas well in Porter Ranch, California between Oct. 2015 and Feb. 2016 had boosted the state’s methane emissions by around 20% during that period.

And with methane trapping some 80 times more heat than CO2, the Southern California leak has been called the worst accidental discharge of greenhouse gases in US history.

SoCalGas, which is owned by natural gas utilities holding company Sempra Energy, late last year pledged to mitigate the environmental impacts of the leak, and California Governor Jerry Brown subsequently directed ARB to prepare a programme to be funded by the firm.

In the draft, the agency identified a number of greenhouse gas sources, and specifically short-lived climate pollutants such as methane, that can be targeted by projects funded by the firm.

ARB proposed that as its primary emphasis, the portfolio of projects target methane from the agriculture sector, including the dairy industry, and from the waste sector, including landfill and wastewater.  These sectors make up around three-quarters of California’s total methane emissions.

“ARB envisions that methane reduction projects will be the primary focus of the mitigation programme for the simple reason that methane is not well controlled today,” the document said.

ARB said efforts could also promote renewables and energy efficiency or decrease reliance on fossil fuels, for example through initiatives to incentivise the replacement of old appliances or subsidies for low- or zero-emission vehicles.

Additionally, SoCalGas could target methane “hot spots” not presently targeted under federal, state or local laws, such as abandoned oil and gas wells.

Such a programme, ARB added, could “set the stage for substantial additional emission reductions”, but noted that methane from the agricultural and waste sectors would likely need to be the main target in order to meet the overarching mitigation goal.

“The state must seize these opportunities in order to achieve the governor’s goals of a 40% reduction in statewide emissions of greenhouse gases by 2030, and an 80% reduction by 2050.”


ARB ruled out involving allowances or offsets from California’s carbon market, saying their use would be inappropriate for several reasons, including the fact that the reductions would not be additional, and that the cap-and-trade scheme, “with its carefully calibrated annual emission caps, was not designed to capture fugitive emissions from sources such as Aliso Canyon”.

“SoCalGas’s purchase of compliance instruments commensurate with Aliso Canyon emissions, therefore, could tighten the [carbon] markets … and potentially impact the cost and ability of regulated entities to comply,” it added.

ARB said every effort should be taken to look for project opportunities in Southern California, and more specifically in the areas affected by the Aliso Canyon leak, but warned that limiting the programme to certain regions could result in the reductions falling short, coming at an excessive cost, or failing to achieve transformative results.

At a minimum, it said, each project must occur within California, complement existing government efforts, and yield real, verifiable, and permanent reductions that are additional to those that would be achieved under a BAU scenario and those already being undertaken by SoCalGas.

It recommended that any emission reductions occur within a defined timeframe, “ideally five and not more than 10 years” from the start of the leak.

ARB said it is also considering whether to incorporate a minimum supplemental financial commitment in the plan, which would serve as a ‘backstop’ to ensure full mitigation in the event that the projects’ cuts fall short.  But the agency said such a measure should be discussed in connection with the overall programme’s implementation.

ARB is concurrently a plaintiff in a civil lawsuit against SoCalGas over the Aliso Canyon leak.

“The relationship between this lawsuit and the mitigation programme described in this draft remains to be fully determined. If, for example, the pertinent claims in People v. Southern California Gas Company are resolved in the plaintiffs’ favour and the court orders mitigation by SoCalGas, or should the case result in a settlement agreement between the plaintiffs and SoCalGas that is then entered as a consent decree by the court, these resolutions could provide an avenue for enforcing the provisions of any agreed-upon or compelled mitigation programme.”

ARB is inviting comments on its recommendations until Mar. 24, and will publish a final version of its plan on or before Mar. 31.

By Mike Szabo –