Enbridge puts Line 5 leak cost at least $15.1 million

Estimated costs

Enbridge estimates its response to an August leak from Line 5 in Iron County will cost at least. The estimate appears in an accident report the company filed with the federal Pipeline and Hazardous Materials Safety Administration.

Emergency response accounts for nearly of the total. Enbridge put public and private property damage and repair costs at about. Environmental cleanup and the value of lost product make up the rest.

The leak and shutdown

Enbridge said an unoccupied flatbed truck belonging to a subcontractor rolled into an open excavation for a Line 5 valve project. The truck struck and punctured the pipeline.

The company isolated the affected section and shut down Line 5. No one was injured, and one nearby rural home was evacuated as a precaution. Enbridge told regulators that about 33,000 barrels, or more than 1.3 million gallons, of natural gas liquids escaped. Most of the propane and butane vaporized, while 165 barrels were recovered from the trench.

A preliminary finding in a federal corrective action order said the truck had been left unattended in neutral on a slope. The cause remains under investigation. Enbridge said it shut down the pipeline within three minutes, and Line 5 returned to service Sept. 13.

Investigation and monitoring

Enbridge said air monitoring outside the incident site has shown safe conditions and monitoring wells have found no contamination. The company also said wildlife and water have not been affected, while soil and water monitoring continues. It plans to test, remove and dispose of soil from the excavation area.

Federal investigators will inspect the truck. Stress Engineering Services will conduct mechanical and metallurgical testing on the damaged pipe section. PHMSA may take further enforcement action if its investigation finds federal safety violations or a need for additional corrective work.