Background Information on the Aliso Canyon Natural Gas Leak

Public Health was notified on October 28, 2015, that there was a natural gas leak that began on October 23 at the Aliso Canyon Gas Storage Facility near Porter Ranch. Since the beginning of the incident, air samples have been collected to monitor the levels of chemicals associated with the leaking gas. On November 19, Public Health issued a directive to the Southern California Gas Company (SoCalGas) to expedite efforts to stop the leak and in the interim offer free, temporary relocation to affected residents to provide relief from the odorous emissions. On December 16, Public Health directed SoCalGas to work directly with the Los Angeles Unified School District to assist in relocating affected students to alternate locations outside of the impacted area.

Since the beginning of the incident, air samples have been collected to monitor the levels of chemicals associated with the leaking gas. In January 2016, Public Health implemented the Expanded Air Monitoring Plan (EAMP) to include more community air sampling locations, to expand testing for additional chemicals, and to increase sample collection times.

On February 11, SoCalGas reported the flow of gas from Well SS-25 had been stopped, and on February 18, 2016, the California Division of Oil, Gas and Geothermal Resources (DOGGR) confirmed that the leaking well at the Aliso Canyon facility has been permanently sealed. A review of the cumulative monitoring results suggests that levels of chemicals of concern are consistent with expected background levels for the Los Angeles air basin. Outdoor air monitoring continues to be conducted and Public Health continues to address community health concerns and consult with local and State regulatory agencies. For more information on community air monitoring near Aliso Canyon please visit the California Air Resources Board and the South Coast Air Quality Management District

Public Health continues to actively monitor and assess environmental and health issues related to the natural gas leak at the Aliso Canyon Storage Facility. Some residents are continuing to report symptoms that they experienced during the leak upon returning home. Approximately 300 residents have contacted Public Health with health complaints, from mid-February to mid-April. The most common symptoms reported are headaches or migraines, nausea, nosebleeds and respiratory health issues.

Cleaning, as designed by Los Angeles County Department of Public Health (Public Health), was ordered in a ruling by Los Angeles Superior Court on Friday, May 20. The Southern California Gas Company (SoCalGas) was ordered to pay for professional comprehensive cleaning in the homes of residents who are relocated due to the Aliso Canyon Gas Leak disaster. The court’s decision required SoCalGas to offer comprehensive cleaning to relocated residents in advance of their return home.

On Sunday, May 22, Public Health imposed an immediate Stop-Work order to SoCalGas after Environmental Health Specialists observed cleaning performed by SoCalGas that did not comply with Public Health’s cleaning protocol. Public Health demanded SoCalGas to produce a work plan to help make sure cleaning was done in accordance to Public Health’s protocol as per the court order. On Wednesday, May 25, Public Health directed SoCalGas to implement their Interior Home Cleaning Work Plan and to begin cleaning. The work plan imposed several layers of supervision and quality assurance that wasn’t implemented by SoCalGas and their contractors when they began indoor cleaning. To continue to protect the residents’ health, Public Health is in the field monitoring the cleaning done by SoCalGas and their contractors.