DNR issues notice of violation to Enbridge involving Line 5 reroute and spill response

The Wisconsin Department of Natural Resources has issued a formal notice of violation to Enbridge Energy Company over alleged violations in Iron and Ashland counties.

The notice, issued October 13, involves alleged violations of permit conditions for the Line 5 reroute project and state environmental laws related to construction of an unpermitted bypass around the site of the August 25 Line 5 spill near Saxon.

According to the DNR, the notice covers alleged violations that occurred between March 30 and September 25, 2026.

The alleged violations involve state water quality, wetland, navigable waterway, air quality, stormwater and endangered resources protection laws.

Among the violations, the DNR cites multiple releases of drilling fluid into Vaughn Creek and nearby wetlands during construction of the Line 5 reroute. The notice also identifies sediment-laden water entering a tributary to Vaughn Creek in July.

Other alleged violations involve the placement of timber matting in wetlands and temporary bridges over waterways without required authorization during construction of the bypass near Saxon.

The notice also alleges air pollution violations stemming from the August 25 spill. According to the notice, Enbridge reported that approximately 32,270 barrels of material released during the spill vaporized and dispersed into the atmosphere.

“Based on this information, Enbridge caused significant air pollution, and did not use good operating practices nor take reasonable precautions to prevent the release from occurring,” DNR Environmental Enforcement Specialist David Hon wrote in the notice.

A notice of violation is a formal letter identifying alleged violations and their potential consequences, including forfeitures.

The DNR says it will continue reviewing incidents that occurred after September 21, along with any future incidents that could result in additional enforcement action.

An enforcement conference between the DNR and Enbridge is scheduled for October 26. The conference will give Enbridge an opportunity to discuss the alleged violations before the DNR determines whether additional enforcement action is necessary.

Following that conference and further investigation, the DNR could issue citations or refer the case to the Wisconsin Department of Justice for prosecution, seeking forfeitures or other court-ordered remedies.

The DNR says specific enforcement actions have not yet been determined.

The notice is separate from Enbridge's ongoing responsibility to investigate and clean up the August 25 spill near Saxon. The spill occurred when an unoccupied vehicle rolled into an excavation site and struck the existing Line 5 pipeline during work on a valve.

The DNR previously issued Enbridge a responsible party letter concerning the spill and says it continues to oversee the company's investigation and cleanup efforts.

Civic Media has reached out to Enbridge for comment but has not yet received a response.