A report analyzing the potential vulnerabilities of natural gas storage facilities and ways to address them was released Monday by a group of states organized by the Interstate Oil and Gas Compact Commission and Ground Water Protection Council.

The report cites the recent leak at the Aliso Canyon underground gas storage facility near Los Angeles.

“Most underground gas storage facilities have safe histories of operation and allow large supplies of gas to be stored during times of low demand, and withdrawn from storage when demand for natural gas is high; thereby reducing the need for larger transmission pipelines and allowing for continuous supply of gas in the event of supply interruptions,” the group said. “However, when an accident occurs it can have dramatic impacts to public health, safety and the environment.”

Today there are more than 400 active underground gas storage facilities in the United States, operated by about 120 companies. More than 80% of the U.S. gas storage is in depleted oil or natural gas reservoirs. Most of the remaining storage is in non-potable aquifers or in salt caverns developed specifically for that purpose, with a few facilities utilizing mechanically mined caverns.

Two of the most serious underground gas storage incidents occurred at the Moss Bluff storage facility in Texas and the Yaggy storage field in Kansas. The Moss Bluff facility was a salt cavern storage operation. In August 2004, casing in one of the wells failed, resulting in a large release of gas and an uncontrolled fire that lasted for more than six days, the report said. The Yaggy incident involved a wellbore failure that led to a series of gas explosions in Hutchinson, KS. The explosions and fire damaged 26 businesses and caused two deaths.

The report, “Underground Gas Storage Regulatory Considerations” is intended to provide a resource for regulatory agencies and includes input from experts in academia, industry, non-profit organizations, and other state and federal agencies.

The 130-page report addresses the regulatory framework of underground gas storage, risk management, state permitting, well drilling and construction, well integrity, reservoir integrity, monitoring, and emergency response planning among other topics.

“A lot of thought and expertise went into this report,” said Hal Fitch, co-chair of the group and division director for Michigan’s Oil, Gas, and Minerals Division, Department of Environmental Quality. “We believe it will be a great resource for state and federal agencies as they work to enhance their oversight of gas storage in the U.S.”