A leaking natural gas storage well at Southern California Gas Co.'s (SoCalGas) largest underground storage field north of Los Angeles may not be fixed for months, officials said Monday, and that has government regulators and environmental groups expressing growing concerns.

Since the Sempra Energy gas-only utility reported well-plugging activity resuming after high winds curtailed work crews the end of last week (see Daily GPINov. 19), the California Air Resources Board (CARB) issued a preliminary snapshot of the methane emissions and global warming implications from the month-old leak at the 86 Bcf Aliso Canyon storage field, equating the volumes with one-quarter of the state's overall methane emissions for the period of Oct. 23 through last Friday (Nov. 20).

On Monday, officials at the Environmental Defense Fund (EDF), which is leading a multi-year national effort to reduce methane emissions across the oil and natural gas supply chain, estimated the emissions from the Aliso Canyon leak at 1.67-1.9 Bcf of lost gas and equating its 20-year global warming impact with the collective emissions of all of the state's refineries or six large coal-fired power plants, or roughly seven million passenger cars.

A SoCalGas spokesperson did not respond specifically to these estimates, or a report over last weekend in the Los Angeles Times noting that residents on the periphery of the sprawling, 3,600-acre storage field are growing impatient and the South Coast Air Quality Management District has counted nearly 500 odor complaints from individuals smelling the leaking gas. The utility is addressing the issues, but at a measured pace that now indicates the plugging of the well may be weeks or even months away.

SoCalGas now plans to drill a relief well adjacent to the 62-year-old well that is leaking, but the utility spokesperson said the relief well process is complex and similar efforts have been known to take several months. "Construction of the well can begin later this week if needed, but we won't be able to provide a more specific estimate of how long this will take until we have a good sense of the initial progress."

From the utility's perspective, there has not been an "unusual increase" in customer calls complaining about the odors, but the company is nevertheless embarking on applying a process that sprays the leaking gas with an environmentally and public health approved product that reduces the mercaptan (odorant) in the gas to make it less annoying to surrounding populations, the closest of which are a mile away in a suburban community called Porter Ranch. The utility also plans to capture more of the leaking gas, the spokesperson said.

In the meantime, on Friday the Los Angeles City Council approved a motion from the local councilman in the area, summoning SoCalGas executives to a meeting with environmental, fire and health officials so the utility can  answer the questions of city officials concerning an incident that has turned out to be anything but routine.

EDF is now describing the leak as "gigantic" and raising questions in local news media of how much the overall natural gas infrastructure is contributing to the emissions of global warming gases on an ongoing basis.

SoCalGas Environmental Services Director Jill Tracy said that once the leak is contained, the utility will calculate the overall volume of the leak and how much gas is still stored underground. "We will use established methods to calculate accurately how much leaked," Tracy said. "We care about the environment and share the public's concern; we are working collaboratively with CARB and other researchers to respond to the incident and reduce any environmental impact."

CARB cautioned that its preliminary estimates are based on "a small number of measurements, and assumes a constant emission rate," which it recognizes is not realistic. A complete calculation will take several months, the agency said.

"The ongoing crisis in Aliso Canyon shows how much is at risk as California's natural gas infrastructure ages," said Tim O'Connor, EDF senior attorney and director of its Climate California program. "It is also a call to action that California needs to get serious about improving oversight and regulatory measures to ensure methane emissions from the oil and gas sector stay in the pipes where they belong."

Although unsubstantiated at this point, the SoCalGas storage well leak is becoming a rallying point for EDF and advocates for the Obama administration's war on methane leakage (see Daily GPIJan. 14).

Aside from the environmental implications and increasing pressure from state officials, SoCalGas' spokesperson said there are no impacts on the operations of the overall Aliso Canyon underground storage field heading into winter. "We don't foresee any system impacts associated with the well leak," he said.