The state's environmental assessment of Enbridge's proposed new Line 3 oil pipeline — heavily criticized by pipeline opponents — has been approved by a state judge.

The environmental impact statement (EIS), done by the Minnesota Department of Commerce, was deemed "adequate" in a ruling released Wednesday by Eric Lipman, an administrative law judge.

The EIS made no recommendations. Rather, the August report assessed potential environmental damage from the proposed 340-mile pipeline that would replace Enbridge's current Line 3. The pipeline transports Canadian oil across northern Minnesota to Enbridge's terminal in Superior, Wis.

Administrative law judges rule on aspects of contested cases before the Minnesota Public Utilities Commission (PUC). The PUC itself still must approve the EIS on the way to voting on Line 3 as a whole, but the judge's decision is likely to play a significant role in that process. A separate administrative law judge is weighing whether a new Line 3 is needed and, if so, which route it should take, based on a separate Commerce Department report plus testimony at public hearings.

The EIS has been labeled deficient on several fronts by environmental groups and Indian bands that oppose the pipeline.

But in his ruling, Lipman concluded that the EIS met the requirements of Minnesota law and "addressed the potentially significant adverse or beneficial environmental, economic, employment and sociological impacts generated by the project and its alternatives." The EIS also "adequately presents methods by which adverse environmental impacts can be mitigated," Lipman wrote.

Calgary, Alberta-based Enbridge said the $2.6 billion project is necessary to replace its current Line 3, a 1960s-vintage pipeline that operates at slightly more than half of its capacity due to safety concerns. A new pipeline would allow the company to restore the full flow of 760,000 barrels of oil per day.

The new Line 3 would run on a new route that is south of the current Line 3. Opponents said it would cut through an area of pristine lakes, rivers and wild rice waters, exposing them to oil spill damage.

The EIS looked at Enbridge's preferred route, which jogs south at Clearbrook past the Mississippi headwaters area toward Park Rapids, where it then heads east to Superior. Two other route alternatives largely follow Enbridge's current Minnesota corridor of six pipelines — including the current Line 3 — which runs roughly parallel to U.S. Hwy. 2. The EIS also looked at two routes that would run farther north or south than the current Line 3.

Among criticisms of the EIS, the environmental group Friends of the Headwaters maintained that the EIS did not assess a possible large oil spill into the headwaters of the Mississippi River or other "high consequence areas" in Itasca and Hubbard counties. Specifically, the group wanted an analysis of a potential leak on par with Enbridge's massive 2010 pipeline spill in Michigan, which cost the company more than $1 billion to clean up.

Lipman disagreed, writing that such specific spill modeling wasn't necessary. "The regulatory guidance in this area suggests that if the agency's assessments are broadly representative of the spill impacts likely to be encountered along the pipeline route, those evaluations are adequate," he wrote.

Honor the Earth, an environmental activist group, argued that the EIS failed to assess the environmental impacts of a new Line 3 at its "rated capacity" — 915,000 barrels of oil per day. Lipman disagreed, writing that Enbridge's proposal before the PUC is to operate the new Line 3 at an annual average of 760,000 barrels per day, not at the rated capacity. Enbridge would have to make a second, later request to the PUC to go above the 760,000-barrel mark, Lipman wrote.

Honor the Earth and the Sierra Club, another opponent of Line 3, disagreed with Lipman's decision. "The people of Minnesota deserve a full accounting of the risks of [the Line 3] project, not a half-baked incomplete review," the Sierra Club said Wednesday of the state's EIS.

Enbridge praised Lipman's conclusions, saying in a statement: "This recommendation comes after months of analysis and public comment and participation."

Mike Hughlett • 612-673-7003