Engineers in California are racing against time to stop massive methane leak at Aliso Canyon, which has led to a state of emergency being declared in the area.
The leak was discovered at the end of October, but in a letter dated December 18, 2015, the Governor of Porter Ranch, Jerry Brown, wrote to the chief executive of the Southern California Gas Company criticising the speed of response. It said: “Since October 23 – eight weeks ago – the natural gas leak at Aliso Canyon has been impacting the local community, polluting the environment and creating a worker safety hazard. I recognise that the gas leak presents a very difficult technical challenge, and your company’s employees are working hard. At this point however, these efforts have proven insufficient.”
Last week the Governor declared a state of emergency in the Porter Ranch area due to the continuing leak. The declaration said major amounts of methane, a powerful greenhouse gas, have been emitted into the atmosphere.
In response to the state of emergency, SoCalGas president and chief executive Dennis Arriola said: “SoCalGas has been communicating with the Governor’s Office and other state agencies from the outset and appreciate their continued support as we work as quickly and safely as possible to stop the leak.
“Our focus remains on quickly and safely stopping the leak and minimizing the impact to our neighbours in Porter Ranch. SoCalGas reaffirms our prior commitment to mitigate the environmental impact of the actual amount of natural gas released from the leak. We look forward to working with state officials to develop a framework that will achieve this goal.
“As we have since this incident began, SoCalGas stands willing and ready to cooperate with the Governor’s office, all state and local officials, and regulatory agencies.”
SoCalGas is drilling two relief wells. These will intercept and directly plug the leak. Drilling began in December, with the earliest estimate for completion the end of February.
The first relief well will be around 450m away and will intercept the leaking well at more than 2,500m underground. Once the leaking well has been intercepted, cement will be pumped into it to permanently cut it off from the natural gas reservoir.
Several government agencies are working to monitor the health and environmental impact of the leak.