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PHMSA Advisory on Underground Storage Safety Provides Insight into California Storage Leak

By John Erickson posted 02-04-2016 10:42 AM

  

The Pipeline and Hazardous Materials Safety Administration (PHMSA) has issued an advisory urging operators of underground storage facilities to have processes, procedures, mitigation measures, periodic assessments and reassessments, and emergency plans to maintain the safety and integrity of all wells and associated storage facilities whether operating, idled, or plugged. While only one or two public natural gas systems operate underground storage, the advisory contains useful information about the leak at an underground storage facility in Los Angeles that is garnering much press attention. This information may be useful to APGA members to answer questions from constituents.

On October 23, 2015, Southern California Gas Company’s Aliso Canyon Well SS25 failed, causing a sustained and uncontrolled natural gas leak in an area known as Porter Ranch in Los Angeles. At the present time, the well leak is believed to be from a subsurface (downhole) well casing. The well was drilled in 1953 as a production well and was later converted to natural gas storage in 1972. Over 4,400 households have been relocated due to the natural gas odorant according to the Aliso Canyon Incident Command briefing report issued on February 1. On January 6, California Governor Jerry Brown issued a proclamation declaring the Aliso Canyon incident a state emergency. After repeated unsuccessful attempts to contain the leak, a relief well is being drilled to plug the leaking well. The Aliso Canyon underground storage field, which can store up to 86 billion cubic feet of natural gas, has 115 storage wells, and is the second largest storage facility of its kind in the United States. The root cause of this failure is the subject of ongoing investigations, however it is clear that this is not related to Southern California Gas Company’s gas distribution pipelines and is not something that could occur on a distribution system.

PHMSA emphasizes that the processes and procedures should take into consideration the age, construction, maximum operating pressures, operating and maintenance history, product, corrosion, casing and tubing condition (including chemical and mechanical damage), cement condition and depths or heights, safety valves (surface and subsurface), operation of each well, and the amount of time elapsed since the most recent assessment. A copy of PHMSA’s Advisory can be found here. For questions on this article, please contact John Erickson of APGA staff by phone at 202-464-0834 or by email at jerickson@apga.org.

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