The state Department of Natural Resources is investigating a possible oil spill near the Bad River Band of Lake Superior Reservation in far northern Wisconsin.
The department said Enbridge Inc. reported Wednesday that a contractor had encountered soil suspected to be contaminated along the company's Line 5 pipeline south of Ashland about a mile west of the reservation.
The DNR says the company stated it couldn't identify a leak and believes the contamination was from a past discharge.
The department says its staff have been on site and haven't detected any additional petroleum odors or soil staining.
