California gas leak now 'permanently sealed'

A METHANE well in Southern California, US, which has been leaking at a rate of over 20,000 kg/h since October 2015 until early February, has now been “permanently sealed” according to a state regulator.

The California Division of Oil, Gas and Geothermal Resources (DOGGR) has verified that the Aliso Canyon storage well, operated by the Southern California Gas Company (SoCal) has been sealed since 17 February.

SoCal reports its relief well was completed, and was used to pump heavy fluids (to control the flow of leaking gas) and cement to seal the base of the leaking well.

Dennis Arriola, chairman and CEO of SoCal, said, “We’ve already started inspecting all of the other wells at Aliso Canyon and will work closely with DOGGR to verify that the wells can be operated safely in the future.

“Now that DOGGR has confirmed that the well is permanently sealed, the operations focus will shift to determining the cause of the leak.”

The California Air Resources Board (ARB) estimates a total of over 94,000 t of methane has leaked into the atmosphere, based on incremental measurements. The board will continue to monitor the residual methane levels to determine how the air quality will affect the health of the nearby Porter Ranch residents.

Richard Corey, executive officer at ARB said, “[ARB] is committed to continuing to make available to Aliso Canyon area residents comprehensive monitoring data about the air quality around their homes. We are also working to ensure that SoCal fully mitigates the climate impact from the leak.”

Health concerns, including short-term symptoms of headaches and nausea forced over 2,000 households to be evacuated in December 2015, and ARB officials are recommending that air quality criteria should be met over a period of consecutive days before residents consider returning.

The Los Angeles County Department of Public Health told residents currently in the area, “Mercaptans and other odorants have not been associated with long-term health effects and short-term symptoms will go away once the odour exposure has diminished.”

Some of the residents are considering legal action against SoCal for the gas leak. The legal firm Weitz & Luxenberg is considering bringing criminal charges against SoCal on behalf of residents, for human health and environmental damages.

Robin Greenwald, head of environmental litigation at Weitz & Luxenberg, said, “This is a major step forward for the residents who have suffered at the hands of SoCal. When companies fail to inform the public in a timely manner that they are in the midst of an environmental and health crisis, they should be responsible both civilly and criminally for such violations of public trust.”

SoCal claims it is not responsible for these damages, claiming the company acted in “collaboration with state regulatory agencies to expedite the response,” lawfully.