A marker for a segment of Enbridge Line 6 in northern Wisconsin. A leak in the line in Jefferson County is now under investigation by the Wisconsin Department of Natural Resources. (Photo | Frank Zufall)

The Wisconsin Department of Natural Resources (DNR) is investigating a major leak from a pipeline managed by the Canadian oil giant Enbridge. Last weekend environmental groups sounded the alarm after learning that Enbridge’s Line 6 pipeline had spilled the equivalent of 1,650 barrels — more than  69,000 gallons — of crude oil  in the town of Oakland in Jefferson County. 

The DNR issued a statement saying that a report of a two-gallon spill was sent to the state agency on Nov. 11. Notifications were sent by Enbridge to the DNR, the National Response Center (NRC), and the Pipeline and Hazardous Materials Safety Administration (PHMSA). The DNR then visited the site on Nov. 11 and 12, with additional follow-up on Dec. 6, according to the agency. On Nov. 14, the spill quantity was updated to 126 gallons (or 2-3 barrels). On Dec. 13, Enbridge again revised the spill estimation to 1,650 barrels (or 69,300 gallons) of crude oil. 

“Under Wisconsin law, entities that cause environmental contamination are responsible for reporting and remediating the contamination,” the DNR states. “Enbridge is providing weekly updates to the DNR regarding the investigation and cleanup process. As investigation and cleanup is an iterative process, the DNR continues to evaluate appropriate next steps, including any potential enforcement actions such as a corrective action order.”

Using the GPS coordinates from the accident report and Google Maps, Wisconsin Examiner found that the spill occurred near a roadway running through a grassy, wooded area. The spill occurred near a waterway that flows into Lake Ripley, close to  a grouping of nature preserves and campgrounds. The accident report noted that the pipeline’s leak detection systems did not notify anyone of the leak. 

The Line 6 leak occurred during the same week that environmental and tribal groups filed new legal challenges against Enbridge’s proposed Line 5 pipeline reroute. Opponents of Line 5 are concerned  that the pipeline, which currently runs through the Bad River Band of Lake Superior Chippewa’s reservation, will still present environmental hazards even if it is  rerouted around tribal lands. The Bad River Band argues that the pipeline poses a risk to the health of the Bad River, which the tribe relies on for food, medicine, and important cultural practices. Environmental groups echo those concerns, and feel state and federal agencies have failed to adequately evaluate the environmental risks posed by  Enbridge Line 5.