The Corps stated in its 54-page decision that tunnel construction complies with all applicable federal laws and regulations, including environmental, cultural, engineering and community requirements, and authorizes Enbridge to work within federally-regulated waters. The Corps does not regulate design or operation of the pipeline itself or anything transported within it.

The permit was granted under a Trump administration’initiative, which Assistant Secretary of the Army for Civil Works Adam Telle said in a statement is “cutting unneeded red tape” and “accelerates the delivery of critical infrastructure.”

The project approval reflects "more than six years of rigorous, comprehensive [Corps] review,” Enbridge spokesperson Ryan Duffy said in an email. 

Bay Mills Indian Community President Whitney Gravelle, whose Tribal organization has been fighting the project over that same period, called the decision "shameful" and "a profound breach of the United States’ treaty trust responsibility to Tribal Nations."

She referenced the 1836 Treaty of Washington in which the Ottawa and Chippewa (Ojibwe) nations ceded nearly 14 million acres, about 40% of the Michigan Territory to the U.S., which enabled Michigan to become a state in 1837. In exchange, the U.S. promised money, goods, and continued hunting and fishing rights. 

"They disregarded our treaty rights, ignored the information we provided through consultation, and pushed past cultural resource obligations under the manufactured excuse of an ‘energy emergency,'" said Gravelle.