Do All Old Oil and Gas Lines Need Pressure Testing?
How safe are all the old oil and gas pipelines that crisscross the U.S., and does it make sense to pressure-test most of them? The federal Pipeline and Hazardous Material Safety Administration is developing a verification process that may subject to hydrostatic pressure testing as much as 95%, or 182,000 miles, of the U.S. pipelines that transport crude oil, gasoline and other liquids. Up-to-date records also would be required.
Evan Vokes, a pipeline safety consultant for Tar Sands Blockade, a coalition of grassroots opponents to the Keystone XL pipeline, sees much sense in the initiative, but oil and gas companies already are questioning the program's legality. In a Feb. 20 joint letter from the American Petroleum Institute and the Association of Oil Pipelines, pipeline operators submitted their first official response to PHMSA's proposal. The groups argued that Congress had not given PHMSA the authority to develop an integrity verification process.
Operators have reasons to squirm. The biggest proposed process would end the grandfather clause that exempts legacy pipelines from pressure testing. This means all pipelines would be pressure-tested, upgraded or repaired according to operating pressure limits contained in federal regulations. Half of all U.S. pipelines in operation were built before 1970. The amount of work could cost billions of dollars.
The ghosts of recent pipeline accidents loom over the debate and public perception. Among the recent well-publicized failures are ExxonMobil's Pegasus Pipeline, which leaked hundreds of thousands of gallons into an Arkansas river in 2013; TransCanada's new Bison Pipeline in Wyoming blew up in 2011; and Pacific Gas and Electric's San Bruno, Calif., pipeline blast killed eight people in 2010. "The writing is on the wall," Vokes says. "PHMSA knows what can happen if some of these pipelines are kept in operation."
The Feb. 20 letter also acknowledged that the San Bruno explosion probe "revealed inaccurate and incomplete documentation to substantiate the maximum allowable operating pressure of the failed natural-gas pipeline." The oil-and-gas sector claims, however, that hydro-testing almost 100,000 miles of pipeline would require billions of dollars and divert attention away from "higher priorities." Plus, says the institute, extensive hydro testing can actually damage a pipeline.
Vokes says hydro testing is the best public safeguard. "The only reason not to hydro-test a pipeline is if you have a low-frequency electric resistance weld that makes cracks worse by hydro testing," Vokes claims."If a pipe is destroyed by a pressure test, then there you go—that's your answer: It's a piece of crap."
The real problem may have to do with pipeline operators not knowing the true strength of their pipelines and making wrong assumptions. PG&E's records for the San Bruno line had the wrong long-seam type, specified minimum yield strength and depth of cover, according to the National Transportation Safety Board's investigation. On one pipeline segment, PG&E assumed a specified minimum yield strength of 52,000 psi, contrary to regulations requiring operators to use a value of 24,000 psi when the yield strength is unknown.
PHMSA doesn't usually direct operators to replace large pipe segments. The new process, which still must survive PHMSA's rule-making protocols, would represent a major expansion of its regulations, says Susan Olenchuk, attorney for Van Ness Feldman LLP, which provides counsel to natural-gas and oil pipeline operators. If the process survives the rulemaking procedure, "the alternatives to pressure-testing, which pipeline operators have been allowed to perform, would no longer be acceptable for establishing maximum operating pressure," says Olenchuk. "So, a majority of vintage pipelines would have to be pressure-tested and either abandoned or replaced if they failed."
The time line for implementation is unclear, but the final result could trigger a vast amount of repair and rebuilding.
