Enbridge reported construction crews breached an aquifer in northern Wisconsin during the last week of September. The incident occurred while drilling under the Marengo River for a controversial project to reroute its Line 5 oil pipeline.
Groundwater has been flowing to the surface. The company stated it is working with the Wisconsin Department of Natural Resources (DNR) to manage and contain the flow.
This marks the project's second significant environmental event in just over a month. In late August, a different pipeline section released over a million gallons of natural gas liquids.
These repeated incidents intensified calls from the Bad River Band of Lake Superior Chippewa and environmental groups. They demand regulators revoke the project's permits.