LOS ANGELES (CN) – More than three years since the country’s largest methane gas blowout at the Aliso Canyon storage field, a new report released Friday found the leak was caused by a corroded pipe saturated with groundwater.
More than 100,000 tons of methane leaked out of the Southern California Gas Company’s storage field near Porter Ranch that forced thousands of families to flee their homes for over 100 days.
The report details inadequate surveillance by SoCal Gas along with a lack of analysis on well leaks going back to 1970.
Microbial levels found on the outside of the pipe that burst in 2015 were on par with levels that would be able to cause metal corrosion according to the 258-page report compiled by a third-party energy consultant.
The report from the state Public Utilities Commission also places blame on SoCal Gas for not performing detailed follow-up inspections after previous leaks going back to the 1970s.
In 1988, an internal SoCalGas memo recommended that an inspection of the outside of 20 wells to see the condition of each well casing. The wells were selected based on the amount of activity they saw. Each well was ranked and the pipe that burst in 2015 was ranked low, but despite all the previous leaks in the field there was no overall review done that would have led to detect corrosion as a potential problem.
A year before the blowout, the utility company formally acknowledged the limitations of their normal well monitoring practices and their standard practices only identified problems that already existed.
The 2015 blowout lasted for 111 days and efforts to shut it down failed because the utility company’s methods were unsuccessful, according to the report, including an emergency response plan being inadequate along with a lack of a well surveillance system.
SoCal Gas reached a $120 million settlement with state and local agencies over the blowout and hundreds of civil lawsuits from residents are currently being coordinated in Los Angeles County Superior Court. Residents complained of headaches, nose bleeds and other symptoms before the utility company notified the public of the blowout.
The leak has caused the utility company more than $1 billion.
The new study was commissioned by the Department of Conservation’s Division of Oil, Gas and Geothermal Resources and the state’s Public Utilities Commission. New safety regulations put in place after the blowout have addressed most of the major concerns, according to the report.