Underground Natural Gas Storage
This site is administered by the Pipeline and Hazardous Materials Safety Administration (PHMSA). It provides information concerning Safe Operations of Underground Gas Storage Facilities for Natural Gas.
On December 19, 2016, PHMSA published in the Federal Register an interim final rule (IFR) that revises the Federal pipeline safety regulations to address critical safety issues related to downhole facilities, including wells, wellbore tubing, and casing, at underground natural gas storage facilities. This IFR responds to Section 12 of the Protecting our Infrastructure of Pipelines and Enhancing Safety Act of 2016, which was enacted following the serious natural gas leak at the Aliso Canyon facility in California on October 23, 2015. This IFR incorporates by reference two American Petroleum Institute (API) Recommended Practices (RP): (1) API RP 1170, "Design and Operation of Solution-mined Salt Caverns used for Natural Gas Storage," issued in July 2015, and (2) API RP 1171, "Functional Integrity of Natural Gas Storage in Depleted Hydrocarbon Reservoirs and Aquifer Reservoirs," issued in September 2015. The final rule was published in the Federal Register on February 12, 2020. A correction to the final rule was published in the Federal Register on July 23, 2020.
Gas Leak at Aliso Canyon Underground Natural Gas Storage Facility
On October 23, 2015, a massive gas leak occurred at the Aliso Canyon Underground Natural Gas Storage Facility near Los Angeles, California. In the wake of that incident, an interagency task force was established that consisted of representatives from the Department of Energy (DOE), Department of Transportation (DOT), the Environmental Protection Agency (EPA), the Federal Energy Regulatory Commission (FERC), the Department of Commerce (DOC), the Department of Health and Human Services (HHS), and the Department of the Interior (DOI), and from state and local governments. The Task Force included premier scientists, engineers and technical experts from across the DOE complex, including five National Labs, the other Federal departments, and the Executive Office of the President.
The Task Force issued a report in October 2016 intended to help reduce the risk of future similar incidents.
Advisory Bulletin ADB-2016-02
On February 11, 2016, in response to the Aliso Canyon Underground Natural Gas Storage Facility incident, PHMSA issued Advisory Bulletin ADB-2016-02 to owners and operators of underground pipeline and storage facilities regarding the safe operation of underground storage facilities for natural gas [Docket No. PHMSA-2016-0016].
The bulletin was issued to remind all owners and operators of underground storage facilities used for the storage of natural gas, as defined in 49 CFR part 192, to consider the overall integrity of the facilities to ensure the safety of the public and operating personnel and to protect the environment. The bulletin was intended to inform operators about recommended practices and to urge operators to take all necessary actions, including but not limited to those set forth in the bulletin, to prevent and mitigate breach of integrity, leaks, or failures at their underground storage facilities and to ensure the safety of the public and operating personnel and to protect the environment. Operators should have comprehensive and up-to-date processes, procedures, mitigation measures, periodic assessments and reassessments, and emergency plans in place to maintain the safety and integrity of all underground storage wells and associated facilities whether operating, idled, or plugged. Operators must adhere to applicable State regulations for the permitting, drilling, completion, and operation of storage wells.
All owners and operators of underground storage facilities used for the storage of natural gas, as defined in 49 CFR part 192, should review their operating, maintenance, and emergency response activities to ensure properly and adequately the overall integrity of the facilities. Operators should identify the potential of facility leaks and failures caused by corrosion, chemical damage, mechanical damage, or other material deficiencies in piping, tubing, casing, valves, and associated facilities. Operators must also consider the importance of reviewing the location and operations of shut-off and isolation systems and reviewing and updating emergency plans as necessary.
PIPES Act of 2016
On June 22, 2016, the PIPES Act of 2016 was enacted (Public Law No. 114-183). With regard to Underground Gas Storage Facilities, the PIPES Act of 2016 (the Act) amends 49 U.S.C. section 60101(a) to define "underground natural gas storage facility" as "a gas pipeline facility that stores natural gas in an underground facility, including—(A) a depleted hydrocarbon reservoir; (B) an aquifer reservoir; or (C) a solution-mined salt cavern reservoir." The Act requires PHMSA to issue, within two years of passage, "minimum safety standards for underground natural gas storage facilities." In addition, the Act expressly allows states to adopt more stringent safety standards for intrastate facilities, if such standards are compatible with the minimum standards prescribed in section 12 of the Act. In order to implement the safety standards, the PIPES Act imposes a "user fee" on entities operating underground storage facilities.
- June 2020 presentation to American Gas Association
- May 2019 presentation to American Gas Association
- August 2018 presentation to Southern Gas Association
- February 2018 presentation to the Louisiana Mid-Continent Oil & Gas Association.
Menu links on the left of this page provide additional information regarding the safe operation of underground natural gas storage facilities. This site will be updated as new information becomes available.
- UNGS Final Rule (Correction)
- UNGS Final Rule
- PHMSA Underground Natural Gas Storage IA Question Set
- UNGS IFR
- UNGS IFR (PDF)
- Full Interagency Task Force Final Report "Ensuring safe and relaible Underground Natural Gas Storage"
- DOE Fact Sheet on Interagency Task Force Recommendations
- 49 CFR Part 192
- UNGS FAQs
- Pipeline Safety: Safety of Underground Natural Gas Storage Facilities; Petition for Reconsideration (PDF)
- Pipeline Safety Underground Natural Gas Storage Grants