Aliso Canyon gas leak
The Aliso Canyon gas leak (also called Porter Ranch gas leak and Porter Ranch gas blowout) was a massive methane leak in the Santa Susana Mountains near the neighborhood of Porter Ranch in the city of Los Angeles, California. Discovered on October 23, 2015, gas was escaping from a well within the Aliso Canyon underground storage facility. This second-largest gas storage facility of its kind in the United States belongs to the Southern California Gas Company (SoCal Gas), a subsidiary of Sempra Energy. On January 6, 2016, Governor Jerry Brown issued a state of emergency. On February 11, the gas company reported that it had the leak under control. On February 18, state officials announced that the leak was permanently plugged.
Aliso Canyon relief well being drilled on December 14, 2015 | |
| Duration | October 23, 2015 – February 18, 2016 |
|---|---|
| Location | Aliso Canyon Oil Field, Porter Ranch, Los Angeles, California |
| Coordinates | 34°18′54″N 118°33′51″W |
| Also known as | Porter Ranch gas leak / blowout |
| Type | Gas leak / blowout |
An estimated 97,100 tonnes (95,600 long tons; 107,000 short tons) of methane and 7,300 tonnes (7,200 long tons; 8,000 short tons) of ethane were released into the atmosphere. The initial effect of the release increased the estimated 5.3 Gt of methane in the Earth's atmosphere by about 0.002%, diminishing to half that in 6–8 years.
It was widely reported to have been the worst single natural gas leak in U.S. history in terms of its environmental impact.
The entire rest of the South Coast Air Basin combined, with a population of about 18 million people, emits approximately 413,000 tonnes of methane and 23,000 tonnes of ethane annually. The Aliso gas leak's carbon footprint could be larger than the Deepwater Horizon leak in the Gulf of Mexico.
In comparison, a remote sensing satellite found that the Raspadskaya coal mine is releasing 762,120 metric tons, or 832,200 short tons, of methane every year, with no remediation planned.