Less than a day after state regulators gave the final approval for Enbridge to start building a new $2.6 billion pipeline across northern Minnesota, the Canadian oil company got to work.

The building began "across Minnesota," Enbridge said, even as environmental and Indigenous groups launched another lawsuit seeking to stop construction.

"We will continue to use every legal avenue available to stop the degradation of our waters for future generations to enjoy our treaty-protected resources on and off reservation," White Earth Band of Ojibwe attorney Frank Bibeau said in a statement Tuesday.

The suit challenges the construction stormwater permit issued by the Minnesota Pollution Control Agency and claims the MPCA gave "virtually no consideration of long-term impacts" to the climate or treaty rights.

It joins several legal actions seeking to stop or at least stall construction of the 340-mile pipeline that would carry an average 760,000 barrels of oil per day between Alberta and the Enbridge terminal in Superior, Wis.

Last week the Red Lake Band of Chippewa and the White Earth Band asked the Minnesota Public Utilities Commission to pause its approval of pipeline construction while the Minnesota Court of Appeals considers permit challenges.

The PUC will consider that request at 10 a.m. Friday.

"Some big questions need to be asked: What if the Appeals Court sides against Enbridge in the legal cases before it?" said Honor the Earth Executive Director Winona LaDuke in a statement Tuesday.

Enbridge previously said in a statement that the bands' petition "only seeks to delay" the new pipeline. "There is no legitimate basis for this filing. The Line 3 replacement project has passed every test."

The $2.6 billion pipeline has been under review for six years and will replace a 50-year-old line that has been running at half capacity because of its age and condition. Enbridge said the replacement pipeline, which will largely follow a new route across the state, will improve safety.

"The replacement of Line 3 is a safety- and maintenance-focused $2.6 billion private investment in Minnesota's energy infrastructure," the company said. "It is the best option for protecting the environment and communities while meeting the region's energy needs."

Pipeline supporters cheered the permit issuance on Monday for the jobs it will bring to a pandemic-ravaged economy.