By Nia Williams and Valerie Volcovici
CALGARY, Alberta/WASHINGTON, Dec 4 (Reuters) – A U.S.regulator’s preliminary investigation into the biggest oilpipeline spill this year has raised a red flag that couldtrigger an extensive and costly inspection of tens of thousandsof miles of underground energy lines.
The 5,000-barrel leak on TransCanada Corp’sKeystone pipeline on Nov. 16 in South Dakota might have stemmedfrom damage caused by a weight put in place when it was built in2008, the Pipeline and Hazardous Materials Safety Administrationsaid in a report published on Tuesday.
Weights are used to prevent pipelines from moving and reducethe risk of damage or ruptures when water tables rise.
The regulator’s finding has implications for the 2,687-mile(4,324 km) pipeline and others throughout the world. Theweights, which tip the scales at 7,000 pounds (3,175 kg) ormore, are commonly used, but only the pipeline operators knowwhere they are located.
Damage from weights “could happen on other segments of thispipeline and other pipelines,” said Najmedin Meshkati, professorof civil and environmental engineering at the University ofSouthern California.
The Keystone pipeline carries 590,000 barrels per day fromAlberta’s oil sands to U.S. refineries. TransCanada’s proposedKeystone XL line would add another 830,000 bpd of capacity.
Nebraska officials approved the construction of that lineeven after the leak, although it is still unclear if TransCanadawill build it.
Depending on the results of the full investigation,construction plans for new lines such as the Keystone XL mayneed modification. Existing lines may also have to be checked, adifficult and potentially expensive undertaking.
U.S. regulators do not have specific information on thetypes of weights or their locations because pipeline companiesare not required to submit data, said Carl Weimer, executivedirector of the non-profit Pipeline Safety Trust.
PHMSA did not respond to requests for comment on thisquestion.
The Canadian Energy Pipeline Association also saidoperators, not regulators, keep tabs on this information. “Wewould not have an inventory; that would need to come from theindividual companies,” said Carla Beynon, a spokeswoman for theindustry group.
On Tuesday, PHMSA ordered TransCanada to clean up the siteand analyze data on the location of other weights on theKeystone line where the land may have similar characteristics aswhere the leak occurred. TransCanada would not say how manyweights were placed along the pipeline, which runs throughseveral states and Canadian provinces, during construction.
In one of those states, the North Dakota Public ServiceCommission, which regulates pipelines, has asked for briefingswith TransCanada on its monitoring procedures. Commissioners arealso waiting to see the full PHMSA report and results of testingon the damaged section of pipeline.
“If there are issues on how this pipeline was designed andconstructed, we will certainly be concerned,” said commissionChairman Randy Christmann.
Using weights made of sand, gravel or concrete is standard,pipeline companies and industry representatives said.
“This is the first time I’ve heard of this type of issuecausing an incident,” said Association of Oil Pipe Linesspokesman John Stoody.
A handful of companies, including PipeSak Pipeline Products& Services and Keymay Industries, manufacture bagged weightsfilled with gravel or permeable textiles, but pipelines builtbefore 2009 like Keystone would probably have7,000-to-9,000-pound concrete weights.
The Keystone line’s coating may have been scratched duringinstallation, which could have led to corrosion, said PipeSakPresident Geoff Connors.
Weimer, the Pipeline Safety Trust director, said problemsduring Keystone’s construction, when ditches filled up withwater, signaled that weighting was needed in those places.
“We are hoping more information gets released about howprevalent the weights are,” he said.
The 5,000-barrel leak came just days before regulators inneighboring Nebraska approved a route for the long-delayed andcontroversial Keystone XL pipeline.
XL opponents, who have campaigned against the pipeline onconcerns that a spill could pollute areas vital to Nebraska’sagriculture industry, said the PHMSA report reinforced thoseworries.
“This has implications for XL, which crosses over theOgallala aquifer and would require similar construction,” saidAnthony Swift, director of the Natural Resources Defense Councilenvironmental group’s Canada Project.
TransCanada did not say whether it would use a similarpractice of weighting for the XL.
Crystal Rhoades, one of two Nebraska Public Servicecommissioners who voted against the last permit needed forKeystone XL, said the commission had no jurisdiction over safetyissues and therefore probably could not revoke TransCanada’spermit or request additional conditions on the pipeline.
Former TransCanada engineer Evan Vokes, a whistleblower,said spills occurred due to shoddy or outmoded constructiontechniques. He said little could be done to prevent leaks onceweights are installed if they are not built in the right places.
“The time to address this is when you put it in the ditch,”he said.
“It’s a pointless exercise to fix it afterwards. It’s likeputting on a helmet and running through a shooting range.”(Additional reporting by Catherine Ngai in New York; Editing byDavid Gaffen, Simon Webb and Lisa Von Ahn)