DC Bureau
Inergy Seeks Approval for Gas Storage in Once Deemed Unusable Salt Caverns
Other Major Safety and Environmental Issues Confront Inergy in the New York Finger Lakes Region
Inergy Salt Plant, Watkins Glen, NY
WATKINS GLEN, N.Y.—A Kansas City energy company is urging New York and federal regulators to disregard explicit warnings about the structural integrity of two salt caverns that it plans to use to store millions of barrels of highly-pressurized liquid propane and butane.
One cavern was plugged and abandoned 10 years ago after a consulting engineer from Louisiana concluded that its roof had collapsed in a minor earthquake. He deemed the rubble-filled cavity “unusable” for storage. It is now scheduled to hold 600,000 barrels of liquid butane.
The other cavern sits directly below a rock formation weakened by faults and characterized by “rock movement” and “intermittent collapse,” according to a 40-year-old academic study that cautioned that the cavern might be plagued by “difficulties in production arising from the geological environment.” That cavern is scheduled to hold 1.5 million barrels of liquid propane.
Both warnings were overstated, according to Inergy LP, which begins the fourth year of its bid to obtain an underground storage permit from the state Department of Environmental Conservation. “There is no reason to believe now that a roof cavern collapse did in fact occur,” Inergy wrote in a confidential 2010 report to the DEC.
The company claims its own tests show the caverns to be structurally sound and suitable for storing the liquefied petroleum gases, or LPG, under pressure of 1,000 pounds per square inch.
Public details of contrary opinions are scarce because Inergy, which bought the caverns from US Salt in 2008, has insisted that their history is a confidential “trade secret.”
Both the DEC and U.S. Environmental Protection Agency have generally accepted that argument and withheld or redacted many historical documents requested under state and federal Freedom of Information laws. However, the EPA did provide one document to DCBureau that disclosed the name of the Louisiana consulting engineer—Larry Sevenker. The DEC later released documents that summarized Sevenker’s 2001 analysis of “Well 58,” the entry point for the cavern now set to hold liquid butane.
