At issue was replacing about 282 miles of existing pipeline in the state with 330 miles of new 36.-in.-dia line and associated facilities. About 90% of the project was “co-located” with other Enbridge pipelines, third-party lines, roads, railroads, or highways, the firm said, also claiming the new line improved environmental protections. “The Corps evaluation was limited to 10% of the project,” Liebesman said.

Line 3, which completed construction in 2021, carries crude oil 1,097 miles from Edmonton, Alberta, to Superior, Wis. The project replaced and expanded the original 1960s-era pipeline, which Enbridge said was corroding and operating at only 50 % capacity. The Minnesota segment was its last to be replaced.

Precision Pipeline, a unit of U.S. contractor MasTec, began construction in December 2020 on the Enbridge Minnesota section.

The dispute centered on whether the Corps should have considered environmental effects of the replacement line’s operation as well as its construction. Plaintiffs claimed the agency violated federal law by not adequately considering direct, indirect, and cumulative project impacts and by not taking a “hard look” at the line’s contribution to climate change.

They said the Corps should have conducted its own environmental impact statement on Line 3—instead of relying on one done by the state—and also failed to fully assess project impacts on tribal treaty rights.

Federal district court Judge Coleen Kollar-Kotelly in Washington, D.C., said in her Oct. 7 decision that the NEPA review is limited to environmental effects associated with specific activity in the Corps permits and “does not extend to the entire pipeline construction, or operation, because the [agency] does not have sufficient control and responsibility … to warrant an expanded analysis.” 

She said the Corps did not need to repeat the state's environmental review.

Opponents had argued that the limit on analysis of operating effects on the environment was “arbitrary and capricious.” 

Beyond Scope

Kollar-Kotelly said that was beyond the mandated Corps review scope, which did not include assessing a potential oil spill that could result from line operation—noting that state environmental assessment included extensive analysis of climate conditions, greenhouse gas emissions, operation impacts, social cost of carbon and upstream and downstream effects.

“The federal court has again failed Indian people and Minnesota's most pristine waterways and landscapes,” said Honor the Earth executive director Winona LaDuke in a statement. Previous rulings in federal and state courts have all upheld project permits. In its statement, Enbridge said the latest decision “acknowledges the thorough, inclusive and science-based [Corps] review.”

Meanwhile, Enbridge has an ongoing legal dispute with the state of Michigan over continued operation of the firm’s aging Line 5 oil pipeline under the Straits of Mackinac. 

The Corps now is conducting an environmental review of the firm’s proposal to construct a $500-million tunnel beneath the straits to contain a new segment of Line 5. A final statement is expected in fall 2024.

Earlier this month, however, the U.S. Environmental Protection Agency raised concerns over the project risks in an environmental review comment.

“We urge [the Corps] to ensure that the [draft review] fully analyzes and discloses spill risks and potential impacts and demonstrates that the project proponent is prepared to adequately prevent and address spills,” EPA said.

In a statement, Enbridge said the planned tunnel “will provide extra layers of safety and environmental protection,” and has said it has spent more than $100 million on the project.

In addition to its fossil fuel projects, Enbridge said it is expanding its renewable energy business, noting offshore wind power investments in Europe and a just announced plan to acquire the third largest U.S. onshore wind developer, Tri Global Energy, for $270 million.