Owners of the Keystone pipeline knew a defect had formed years before the strain finally caused the pipeline to burst and flood a Kansas creek with oil last year.
The Keystone pipeline, owned by TC Energy, burst near the Kansas-Nebraska border late last year, spilling almost 13,000 barrels of oil onto adjacent farmland and into Mill Creek.
It was the largest spill since the pipeline started operating a decade ago and larger than all the others combined. While the December spill was the most severe, it was caused by a manufacturing defect that worsened under stress, like most earlier breaches.
