TOPEKA, Kan. (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.