We continue to progress our remediation and the root cause investigation at our Keystone Milepost-14 incident site in Washington County, Kansas, with the following updates of note:
- We have advanced our root cause investigation with the completion of an independent mechanical and metallurgical analysis of the failed pipe. The analysis concludes that the failure occurred due to a combination of factors, including bending stress on the pipe and a weld flaw at a pipe to fitting girth weld that was completed at a fabrication facility.
Although welding inspection and testing were conducted within applicable codes and standards, the weld flaw led to a crack that propagated over time as a result of bending stress fatigue, eventually leading to an instantaneous rupture. The cause of the bending stress remains under investigation as part of the broader third-party root cause failure analysis.
The metallurgical analysis identified no issues with the strength or material properties of the pipe or manufactured fitting. The pipeline was operating within its operational design and within the pipeline design maximum operating pressure.
Our focus continues to be the safe operation of the pipeline system. Additional operational mitigations, such as reduced operating pressure, are in place to support the safe operations of our system while we continue our response and investigation. Our team is progressing a remediation plan, including an analysis of other areas with potentially similar conditions, the use of additional in-line inspections, and further operational mitigations.
- We have revised the release volume to 12,937 barrels from the original estimated maximum of 14,000 barrels. The revised volume is the actual measured volume of crude oil injected during the re-fill of the pipeline system during its safe restart.
- Our commitment to remediation, investigation and shared learnings is unwavering. To support this, we have arrived at a cost estimate of US$480 million. This estimate may be adjusted as we continue to progress work on site. We have appropriate insurance coverage in place and are working with our insurers to maximize cost recoveries.
We will continue to provide updates as information becomes available.
