An administrative law judge has found that Minnesota pollution regulators properly considered the construction impacts of Enbridge's controversial new pipeline, a blow to the oil pipeline's opponents.

The ruling by Judge James LaFave stems from a challenge to the draft water permits for the pipeline's construction, which were approved by the Minnesota Pollution Control Agency (MPCA) in February.

Three environmental groups and two Ojibwe bands asked for a "contested case" hearing over the draft permits. The MPCA agreed and a hearing was held this summer before LaFave.

In an opinion released Friday, LaFave wrote that the challengers "failed to prove" that construction of the pipeline — a replacement for Enbridge's current Line 3 — would permanently impact water quality and wetlands. Also, that there was no proof that the MPCA and Enbridge had undercounted the amount of wetland affected by the construction.

The $2.6 billion, 340-mile pipeline across northern Minnesota would cross 212 streams and affect more than 700 acres of wetlands.

The MPCA must decide whether to issue final water-quality permits for the new Line 3 by mid-November. The agency said Friday it will take the administrative law judge's report and public comments under advisement.

Enbridge said the judge's decision "confirms that Enbridge and the [MPCA] have identified the best and most prudent method" for stream and wetland protection.

The Laborers Union called the decision "very welcome news." Line 3 would be one of the biggest Minnesota construction projects in recent years, employing more than 4,000 trades workers at its peak, Enbridge said.

Environmental groups lambasted the ruling. "The biggest issues in this case remain whether the MPCA can abdicate its clean water and wetland protection responsibility to the Public Utilities Commission (PUC)," said Scott Strand, attorney for Friends of the Headwaters.

The PUC, which reapproved Line 3 in February, is the primary regulator of oil pipelines in Minnesota.

LaFave, in his opinion, noted that the environmental groups and tribes "vehemently disagreed" with the MPCA's decision to limit the contested case to just five issues.

The groups argued that the MPCA also should have reviewed, among other things, contentions that the new Line 3 violates tribal treaty rights; and that the MCPA's "narrow definition" of its scope and authority is "arbitrary and capricious."

LaFave wrote that "issues raised by Line 3 challengers are very important and go to the ultimate question of whether the MPCA should grant the [water permit] certification."

However, "those issues are not properly before this tribunal and will not be considered as part of this contested case hearing," the ruling said. "The administrative law judge has no authority to second-guess the [MPCA] commissioner's decision or to consider issues other than those that she identified."

Winona LaDuke, head of Honor the Earth, said in a statement that "the Administrative Law Judge had his hands tied by the MPCA before the hearing even started … The agency chose to prohibit the ALJ from considering the potential impacts of oil spills on our waters and resources, including wild rice."

The contested case over the so-called "401" water permits was filed by Honor the Earth, an Indigenous environmental group; Friends of the Headwaters; the Sierra Club; and two Ojibwe bands, White Earth and Red Lake. The MPCA has not granted such a contested case in at least 10 years.

The MPCA's 401 water-quality review goes in tandem with the U.S. Army Corps of Engineers' "404" review.

The state was supposed to complete the 401 by Aug. 15, or the Army Corps could have simply gone ahead and issued its 404 permit. With the contested case, the Army Corps extended the deadline to Nov. 14. The 401 and 404 permits regard construction of the pipeline.

The PUC originally approved Line 3 in June 2018. But that decision was negated when the Minnesota Court of Appeals later shot down the PUC's blessing of the project's environmental impact statement.

The PUC approved a revised environmental study in February, and reapproved Line 3 at the same time.

Enbridge's new pipeline would replace its aging Line 3, transporting crude from Alberta, Canada, to Superior, Wis.

Calgary-based Enbridge has said the pipeline is a critical safety enhancement. The current Line 3 is corroding and therefore running at only half capacity. The new pipeline would restore full oil flow.

Environmental groups and some Indian bands have said the pipeline — which follows a new route — would open a new region of pristine waters to the prospect of oil spills, as well as abetting increased greenhouse gas emissions.