Calgary-based TransCanada Corp. found the leak in Keystone I pipeline late Friday, patched it and opened the valves Sunday. The leak was found nine days ago by a farmer (NOT by the pipeline company) near a pump station in Freeman, South Dakota, a rural area.
Nearly 17,000 gallons—400 barrels—of oil had leaked before the pipeline was shut down from its origin in Hardisty, Alberta, to Cushing, Oklahoma, and Patoka, Illinois. “Clean-up and land restoration has already started and will continue over the coming days,” the company said.
TransCanada excavated four feet of soil along 275 feet to reach the buried pipeline to find the leak, which took several days. It claims it found no significant environmental impact from the spill. That’s a matter of opinion. Typically, clean-ups do not collect all the spilled oil when leaks occur.
Whatever the level of environmental damage, “significant” accidents are defined as those in which someone is hospitalized or killed, damages amount to more than $50,000, more than five barrels of highly volatile substances or 50 barrels of other liquid are released, or when liquid explodes or burns.
Julie Dermansky at DeSmogblog reports that Evan Vokes, a former TransCanada materials engineer, predicted after he heard about the leak that it would be found at a “transition weld” where the pipeline crossed under a road. Such welds connect thinner-walled pipe to thicker-walled pipe:
It turns out that Vokes’s prediction was right. In a corrective action notice issued to TransCanada on Saturday, the Pipeline and Hazardous Materials Safety Administration (PHMSA), the agency that regulates interstate pipelines, indicated the probable cause of the leak was from a girth weld anomaly at a transition site.
Vokes warned his former employer and PHMSA about the transition welds, which he described as “inherently risky.” Welding different thicknesses of pipe together is harder to do than welding the same thickness, and it is more difficult to get accurate X-rays of welds.
Vokes sent an email to TransCanada CEO Russ Girling noting that the company was ignoring a PHMSA advisory issued in 2003 that warned against using transition welds because they are prone to cracking under stress. Vokes told DeSmogBlog that there could be countless undetected slow leaks in the pipeline because there are so many transition welds along its 3,000-mile route.
The company said it is monitoring the pipeline and running it at reduced pressure for now as part of a conditional start-up agreement with federal regulators. It plans to continue aerial surveillance and visual inspections at the site to ensure that new welds are doing their job. The restart was approved by the Pipeline and Hazardous Materials Safety Administration (PHMSA), an agency of the U.S. Department of Transportation.
The Keystone pipeline normally carries up to 590,000 barrels a day—24.8 million gallons—of light and heavy crude oil in the form of dilbit—diluted bitumen—from the Alberta tar sands to a refinery and storage tank farm in Illinois and refineries in Port Arthur, Texas. Phillips 66 said last week that it was forced to shut down several units of its 306,000-barrel-a-day refinery in Wood River, Illinois, while Keystone was closed.
Last year, an analysis of federal data by the Associated Press found that the annual number of significant leaks in oil pipelines had risen by 60 percent since 2009, more or less a match for the increase in U.S. crude oil production. Around two-thirds of those leaks were caused by corrosion, material failure, bad welds or equipment failures. The rest were caused by natural disasters or human error.
From 1995 to 2015, more than 2,000 significant accidents involving pipelines carrying crude oil and refined petroleum products caused $3 billion in damage to property, according to the PHMSA.
(Originally appeared at DailyKos. Image CC from flickr.)