Enbridge says Line 5 Wisconsin NGL release on track for Sept. 12 restart as crews finish temporary bypass

Line 5 restart remains scheduled for Sept. 12

Enbridge said on Sept. 9 that crews are continuing around-the-clock work on a temporary bypass at the site of a third-party line strike in northern Wisconsin, and that the work remains on schedule to bring Line 5 back into service by Sept. 12. "Enbridge crews are working around the clock at the site of a third-party line strike in northern Wisconsin and have made good progress towards gaining full access to the site and restoring service to the pipeline," the company said in a Sept. 9 update posted at 4:30 p.m. CT. "Crews are on track to restore service to Line 5 by Sept. 12."

Ongoing monitoring shows no contamination outside evacuation zone

Enbridge said community air monitoring continues to show safe air quality outside the evacuation zone and in the area where crews are working. Samples of surface water and from a nearby residential well have been tested and show no impacts, while newly installed water monitoring wells around the site also continue to show no contamination. The company added that soil and water monitoring plans are in place, as are plans to test, remove, and properly dispose of soil in the trench, and that the flatbed truck involved in the incident remains onsite pending removal in conjunction with ongoing investigations. A no-fly zone ordered by the Iron County Sheriff remains over the site.

Cause and current status of the pipeline

According to Enbridge, the incident occurred on Tuesday, Aug. 25, when a parked and unoccupied subcontractor flatbed truck delivering equipment to a Line 5 valve project rolled forward into an open excavation, struck the pipe and released natural gas liquids, mainly propane and butane. The company said NGLs are transported by pipeline as liquids but rapidly vaporize into gases when exposed to normal outdoor conditions. No one was injured, a nearby rural home was evacuated as a precaution, the affected section of pipe was immediately isolated, and Line 5 remains shut down pending completion of the bypass work.

Federal data places the August release among Wisconsin's largest spills

Separately, a WPR review of federal Pipeline and Hazardous Materials Safety Administration data found that the Aug. 25 Iron County release of 31,000 barrels — about 1.3 million gallons — of natural gas liquids is the largest oil and gas pipeline spill reported in Wisconsin in more than 50 years. WPR's analysis of hazardous liquid accident data submitted by Enbridge and its predecessor Lakehead Pipe Line Company since 1970 showed the next-largest release at 6,000 barrels of crude oil in Jefferson County in 1973. Enbridge spokesperson Juli Kellner said the "vast majority of the remaining two thousand barrels of liquid initially contained within the excavation site have now also vaporized and dispersed," and that crews continue removing remaining liquid from the trench. PHMSA is investigating the incident, and environmental groups including Clean Wisconsin and the National Wildlife Federation are pressing the Wisconsin Department of Natural Resources and Governor Tony Evers for an independent investigation and a review of permits for Enbridge's roughly $1 billion Line 5 reroute; the governor's office referred questions to the DNR, which did not immediately respond.