TC Energy Mill Creek Oil Spill Emergency Response

Following completion of oil removal activities within the 216 OAs in Mill Creek, the impacted stretch of the creek was refilled with water to levels above normal flow conditions to ensure oil-impacted creek banks were saturated. Water was maintained at this level for 5 days and visual inspections were conducted. This activity was completed to identify any residual areas of oil or oil-contaminated soil/sediment that require further cleanup. No sheening or oil associated with a source that could be addressed was observed in these segments. The full extent of Mill Creek, impacted by the oil spill, has been visually inspected and no areas of concern have been noted.

Approximately 3.5 miles of Mill Creek have been dewatered and oil removal activities completed for all 216 OAs within the oil-impacted segment of Mill Creek. Response activities ongoing include completion of excavation work at the pipeline discharge location to remove the remaining oil-contaminated soil, disposal of oil-impacted soil and sediment, and the restoration of lands impacted by the response. All wastes generated during the cleanup are being sampled for characterization and transported for disposal at appropriate off-site facilities. Phase II Diversion of Mill Creek remains in operation to allow for restoration activities to be conducted.

On May 8, 2023, the USACE authorized TC Energy to begin restoration work on Mill Creek under Nationwide Permit 27.

Approximately 2.2 miles of Mill Creek remain dewatered. Phase II Diversion of Mill Creek is completed and begins operation. Construction and implementation of the surface water treatment system completed. Daily effluent of treated surface water confirmed no detectable concentration of oil-related contaminants.

Approximately 2.2 miles of Mill Creek has been dewatered to allow for in-channel oil-impacted bank and sediment removal. Mill Creek has been anecdotally divided in to 100-foot sections, called Operational Areas. Following removal of all oil-impacted water, sediments, and vegetation; each Operational Area will be qualitatively and quantitatively assessed to determine if cleanup standards have been accomplished. Construction of improved diversion and surface water treatment system is on-going.

Approximately 1.25 miles of Mill Creek has been dewatered to allow for in-channel oil-impacted bank and sediment removal. Construction of a Phase II diversion system begins, which will increase the volume of surface water that can be diverted from 20 cubic feet per second (cfs) to 100 cfs. Construction of the surface water treatment system continues. Two members of the U.S. Coast Guard - Atlantic Strike Team mobilize to the response to support EPA oversight activities.

TC Energy begins construction of a large surface water treatment system, including a 5-acre treatment pond with a volume of 18.8 million gallons, and begins dewatering Mill Creek. Removing surface water from the creek will allow TC Energy to efficiently recover oil impacted banks and sediments through manual and mechanical tactics.

Sample results from domestic-use drinking water wells do not identify any contamination associated with the discharged oil. Freezing conditions again complicate oil removal progress.

TC Energy completes bulk oil recovery. To illustrate oil recovery progress, the extent of oil that was bank-to-bank on Mill Creek on December 15, 2022, was approximately 1.5 miles in length. Additionally, oil on the surface of Mill Creek measured more than 10 inches in depth in portions of that 1.5 mile stretch. As of January 25, 2023, the extent of bank-to-bank oil was approximately 500 feet in length and the depth of oil on the creek surface was generally less than 1 inch. Recovery tactics begin shifting to address the remaining areas of oil on the surface water, banks, and sediments of Mill Creek.

Improved weather conditions and implementation of effective recovery tactics have reduced the heaviest oiling of Mill Creek to locations in and around the 20th Road bridge.

Agencies including the U.S. Army Corp of Engineers, U.S. Fish and Wildlife Service, and Kansas State Historic Preservation Office are consulted on TC Energy's requirements during the response to remove oil from Mill Creek.

KDHE rescinds the Mill Creek stream advisory downstream of 21st Street bridge due to improved surface water conditions that were a result of the diversion implementation.

 Click here to view Mill Creek stream advisory information on KDHE website. 

EPA issues TC Oil Pipeline Operations, Inc. a Clean Water Act Section 311 (c) and (e) enforcement order to ensure a comprehensive approach to assessment and cleanup activities under EPA's oversight.

TC Energy completed isolation of the impacted reach of Mill Creek and implemented a diversion that pumps surface water upstream of the pipeline rupture to a location downstream of the underflow dams. The National Weather Services begins provided support to response.

TC Energy completes repair and restarts the Keystone pipeline.

TC Energy begins using mechanical recovery operations to collect ice and oil due to freezing conditions. Recovery locations are limited to areas in and around the 20th Road bridge.

KDHE issues TC Energy an emergency order for effluent standards for treated water discharge.

Freezing conditions begin to slow oil recovery operations.

EPA deployed an additional three OSCs for response oversight. A second underflow dam was constructed downstream of the first underflow dam. An estimated 3.74 miles of Mill Creek were visibly impacted, of which 1.32 miles remained heavily impacted. Oil recovery tactics include the use of vacuum trucks and skimmers. Other primary response activities include:

• Air monitoring
• Pipeline repair
• Oil impacted soil excavation
• Surface water sampling
• Wildlife assessments

EPA deployed an additional OSC and two START contractors and established roving air monitoring points at perimeter locations near residential properties.

Kansas Department of Health and Environmental issues a Stream Advisory for Mill Creek from 18th Road to it's confluence with the Little Blue River.