The project employed more than 500 local workers and brought a total of more than 5,000 construction jobs to the region, he said. “We hoped that all parties would accept the result of the thorough, science-based review and multiple approvals of the project. Line 3 passed every test for six years of regulatory and approval review, ”he said.

So far, the protests have had little impact on construction, which began in December and is 60 percent complete, he said.

The current crude oil pipeline was built in the 1960s and was ravaged by corrosion, leaks and leaks, forcing Enbridge to reduce its capacity by half to 390,000 barrels per day in 2008. In 2015, Enbridge cited corrosive pipes and future oil needs to say that Line 3 would be diverted, a move that would allow it to restore its original capacity.

Opponents have tried a number of legal challenges. One case is expected to be ruled this month, filed by tribes and environmental groups in the Minnesota state court, focusing on whether Enbridge has conducted an appropriate environmental review.

Two other cases challenge the project’s permits issued by the Army Corps of Engineers under the Clean Air Act. Opponents argue that the Army Corps failed to fully consider how an oil spill would affect the Lake Superior drainage basin.

Local lawyers and lobbyists are also working on their Washington connections. Late last month, Ms. Houska, the tribal attorney, urged high-ranking Biden officials on what they believe to be a political hypocrisy: How could the government allow Line 3 to continue after Keystone XL was canceled?

“This is a huge project with a huge impact on the climate,” Ms. Houska told Gina McCarthy, the White House’s national climate adviser, and David Hayes, who advises Mr. Biden on land and water policy issues. “You can’t demolish Keystone and then build an almost identical tar sands pipeline,” she said.