(AP) — The operator of an oil pipeline says a faulty weld at a bend in an oil pipeline contributed to a spill that dumped nearly 13,000 bathtubs' worth of crude oil into a northeastern Kansas creek.


Canadian-based TC Energy also estimated Thursday that the cost of cleaning up the spill will be $480 million. The spill occurred Dec. 7 on the company's Keystone system in rural pastureland in Washington County.


The company says the weld was for a fitting that connected two sections of pipe, and the fitting and weld came from a manufacturing plant. TC Energy said it's analyzing other parts of the pipeline that could have similar issues.  The company, which is responsible for overseeing inspections of its pipeline system, said it still is investigating the cause of the pipeline stress and is analyzing "other areas with potentially similar conditions."


No one was evacuated following the spill, and officials said it did not affect the two larger rivers and reservoir downstream. With federal regulators' permission, the company reopened the affected segment a little more than three weeks after the spill, though at a lower pressure than before.


But Bill Caram, executive director of the advocacy group Pipeline Safety Trust, said it's "troubling" that TC Energy said the flawed weld came from a "fabrication facility." He said conditions there should have been ideal for making a weld that would not fail — as opposed to welding in the field. Caram said, "It begs the question of how many other bad welds are on the Keystone pipeline from this same fabrication facility."


The spill was the largest onshore in nine years and larger than than 22 previous spills on the Keystone system combined, according to U.S. Department of Transportation data. That's even though the company decreased its estimate for its size from its initial figure of 14,000 barrels. The company's statement Thursday said an analysis of the pipeline's metal showed no issues with it or its strength.

Local farmer Bill Pannbacker said the rupture occurred near his property line, spraying crude onto his pasture at a point after the pipe goes under a creek and starts to ascend an 80-foot hill. He said crews swarmed over the area as they cleaned up the mess, aided by relatively dry weather.

Calling it, "like a little city out there," Pannbacker, a former Kansas House member...said they are working hard.


The Kansas House energy committee plans to have hearings on the oil spill in March. The 2,700-mile Keystone system carries heavy crude oil extracted from tar sands in western Canada to the Gulf Coast and to central Illinois.