A flow of water was observed after Enbridge installed pipe beneath the Marengo River in northern Wisconsin, the company said Oct. 6. The work is part of a planned reroute of its Line 5 oil and gas pipeline. Enbridge spokesperson Juli Kellner said the company is working with the Wisconsin Department of Natural Resources and engineering and environmental specialists to determine what comes next. It was not clear how much water had flowed from the aquifer. The DNR did not respond to a request for comment. The breach adds to scrutiny of Line 5 construction and operations. In August, a damaged section of the pipeline released more than 1.3 million gallons of natural gas liquids. Federal data cited by Wisconsin Public Radio described that release as the largest reported oil or gas spill in Wisconsin and the largest of its kind for Enbridge. Enbridge also breached an aquifer while building its Line 3 pipeline in Minnesota, causing an uncontrolled release of hundreds of millions of gallons of groundwater. Minnesota’s attorney general filed charges against the company in that case. Line 5 can carry up to 23 million gallons of crude oil and natural gas liquids a day from Ontario to the southern United States. The Bad River Band of Lake Superior Chippewa sued Enbridge in 2019 seeking to shut down the pipeline and remove the company from tribal lands. Enbridge is pursuing a route around the reservation, a project opposed by tribal communities and environmental groups over concerns about ecosystems and natural resources. The pipeline’s future remains the subject of federal court battles.