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OPA - TC Energy Mill Creek - UCGPE23702

Site Contact:
Jeff Pritchard
On-Scene Coordinator


Site Location:
Washington, KS 66968
NRC#: 1354446


On the morning of December 8, 2022, TC Energy reported a pressure drop in a 36-inch crude oil pipeline, part of the Keystone pipeline system near Washington, Kansas. The pressure drop was documented at approximately 9:30 pm on December 7, 2022. The pressure drop was confirmed to be from a line rupture south of a Mill Creek crossing. The pipeline rupture resulted in wide-spread vegetation staining. In addition, oil discharged overland and into Mill Creek, a nearby perennial stream. TC Energy estimates the total oil volume discharged as 588,000 gallons (14,000 barrels).

Two EPA On-Scene Coordinators (OSC) mobilized to the response the morning of December 8, 2022, integrating into Unified Command with Kansas Department of Health and Environment (KDHE) and TC Energy. TC Energy enacted their pipeline response plan and commenced oil containment and recovery activities mobilizing numerous resources including oil containment booms, vacuum trucks, frac tanks, light stands for night operations, and heavy equipment. Impacts to Mill Creek initially extended approximately three miles downstream to a bridge crossing at 20th Street. To provide containment and prevent downstream migration of oil on Mill Creek, an underflow dam was constructed on the creek at a low water crossing road approximately four miles downstream of the pipeline rupture.

Operations have primarily utilized mechanical and traditional recovery methods to remove oil from Mill Creek. As of January 29, 2023, the recovery of bank-to-bank oil on Mill Creek was complete. Additionally, segments of Mill Creek have been dewatered, allowing for low-ground pressure machinery to mechanically recover oil-impacted debris, sediment, and vegetated shoreline. Manual recovery is being conducted in sensitive areas to reduce negative impacts. Pre- and post-removal assessments that include sediment sampling are conducted to evaluate the effectiveness of the cleanup actions.  

The dewatering of Mill Creek entails pumping the surface water into a phase separation pond that is part of a larger water treatment system that is currently under construction. The water treatment and discharge are being conducted under KDHE oversight. In addition, diversion of surface water from Mill Creek upstream of the pipeline rupture began on January 5, 2023, and is ongoing. The water is diverted to a location downstream of the underflow dam to reduce the flow of surface water into the impacted portions of Mill Creek. Construction is also underway for additional infrastructure to increase diversion pumping capacity. The upgraded diversion is scheduled to be completed by early March 2023.    

EPA and TC Energy signed a Clean Water Act Consent Order in January 2023 that requires TC Energy to perform the response under EPA oversight. Additionally, EPA OSCs continue to coordinate with federal, state, and local response personnel.