SCAQMD Hearing Board Orders SoCalGas to Enact Comprehensive Program to Cut Odors and Air Pollution from Aliso Canyon Gas Leak

January 23, 2016

In response to a petition from the South Coast Air Quality Management District, the agency’s independent Hearing Board today ordered SoCalGas to take immediate action to minimize odors and air pollution from a massive gas leak near Porter Ranch.

“As a result of this order, SoCalGas must take immediate steps to minimize air pollution and odors from its leaking well and stop the leak as quickly as possible,” said Barry Wallerstein, SCAQMD’s executive officer. “It also will require the utility to thoroughly inspect all other wells at its Aliso Canyon storage facility to help prevent another major leak in the future.”

Once the leak is stopped, the order requires that SoCalGas permanently shut down the well causing the leak. It also requires enhanced air quality monitoring in the nearby community and completion of a health study on the potential health effects of well emissions on residents in the Porter Ranch area. And it requires a comprehensive leak detection program for all other wells in the Aliso Canyon facility to help prevent future leaks.

The Hearing Board voted to adopt the order following four separate days of hearings that included testimony from more than 110 residents and elected officials. Hearings were conducted on three Saturdays in the northern San Fernando Valley and one weekday in Diamond Bar.

Today’s order specifically requires SoCalGas to: 

  • Permanently shut down and seal the well and not inject gas into or withdraw gas from it in the future once the leak has stopped;
  • Fund an independent health study to assess any potential health effects to residents from the gas leak, including as a result of exposure to odorants added to natural gas (tertiary butyl mercaptan and tetrahydrothiophene);
  • Fund continuous air monitoring to be conducted by SCAQMD and/or a contractor under the agency’s supervision;
  • Develop and implement an enhanced leak detection and reporting program for all wells at the storage facility;
  • Monitor the leaking well continuously with an infrared camera until 30 days after the leak has stopped;
  • Minimize gas leaking from the facility;
  • Provide SCAQMD with data on the amount of gas injected and withdrawn from the facility and information necessary to calculate the total amount of methane leaked, once the leak has stopped;
  • Submit a plan to SCAQMD for notifying government agencies and the community of any reportable releases of air emissions, as defined in the plan;
  • Report all odor complaints to SoCalGas since Oct. 23, 2015, and on an ongoing basis to SCAQMD; and
  • Not use any odor suppressants or neutralizers in an attempt to reduce odors from the leak, unless approved by SCAQMD.

The Hearing Board will conduct a follow-up hearing to review the status of the order on Feb. 20 at a location to be determined in the San Fernando Valley. The order extends through Jan. 31, 2017, unless SoCalGas has completed all requirements sooner, or the Hearing Board modifies the order.

Today’s order follows an action earlier this month by the South Coast Air Quality Management District’s Governing Board in which it adopted a resolution, sponsored by Los Angeles County Supervisor Michael Antonovich, urging Gov. Jerry Brown to request that greenhouse gas mitigation fees obtained from SoCalGas be used to fund projects benefitting Porter Ranch.

On Oct. 23, 2015, SoCalGas discovered a leak in well SS-25, one of 115 wells in the company’s Aliso Canyon underground natural gas storage facility in the northern San Fernando Valley. The facility – one of the largest in the country -- has the ability to store a working capacity of more than 86 billion cubic feet of natural gas. To date, SoCalGas’s attempts to stop the leak have been unsuccessful and the company projects that it will not be able to fix the leak until late February.

Meanwhile, SCAQMD in cooperation with other environmental agencies continues its intensive air monitoring effort in Porter Ranch to measure levels of methane, the chief component of natural gas, along with air toxics including benzene, and sulfur compounds added to natural gas that give it a foul odor.

Hundreds of residents have reported that the foul odor of leaking natural gas has triggered symptoms including nausea, headaches and dizziness.

SCAQMD’s air monitoring, enforcement, health impact estimates and other activities regarding Aliso Canyon are reported on its website at

The SCAQMD is the air pollution control agency for Orange County and major portions of Los Angeles, San Bernardino and Riverside counties.