Aliso Canyon Gas Leak Marks 10 Years of Largest U.S. Methane Disaster

The Aliso Canyon natural gas leak, discovered on October 23, 2015, was the largest methane leak in U.S. history, lasting nearly four months and releasing approximately 109,000 to 120,000 metric tons of methane. This environmental disaster caused widespread health problems for thousands of nearby residents, including respiratory issues, headaches, and long-term effects such as low birth weight in babies, and led to the displacement of many families. Despite the severity of the leak, the storage facility has continued operations under new regulations aimed at preventing similar incidents, though concerns remain among residents. Southern California Gas Co. has paid over $1 billion in settlements and penalties related to the leak, and ongoing studies continue to assess health and environmental impacts. The incident highlighted significant vulnerabilities in the U.S. natural gas system management, prompting increased oversight and advancements in methane detection and regulation. Ten years later, the legacy of the blowout continues to influence public health, climate policy, and community activism in the region.