A 2,169-page review of how PolyMet Mining Corp. plans to open Minnesota’s first copper mine and abide by all state and federal environmental laws went public Friday after years of behind-the-scenes drafting.

The revised environmental impact statement — released by the Minnesota Department of Natural Resources, U.S. Army Corps of Engineers and U.S. Forest Service — now is open for public review and comments until March 13.

Meetings have been set in January in Duluth, St. Paul and Aurora, Minn., to explain the review and take questions and comments.

While regulatory agencies and mining industry officials said Friday’s release marks a historic event in the decades-long PolyMet saga, they also made it clear the release is nowhere near an endorsement or approval for the project.

“This demonstrates that the system is working the way it was meant to work. Now we can at least all be working from the same set of facts instead of suggestions and rushes to judgment,” said Frank Ongaro, executive director of Mining Minnesota, a copper industry group.

The document goes into detail on issues including Polymet’s impact on overall water quality and nearby wetlands.

Several chemical elements, including metals, exist naturally in waters in the area. But left uncontrolled, “the proposed project has the potential to elevate three types of constituents,” the report says, including sulfates, metals and mercury.

The Toronto-based company hopes to begin mining in 2016. The project would at first employ about 300 people but at some point could add another 60 jobs if a hydrometallurgical processing plant is built in later years.

The proposed NorthMet mine near Babbitt, Minn., and processing plant near Hoyt Lakes, Minn., would be Minnesota’s first copper-nickel mining operation if it wins all the necessary approvals.

Minnesota DNR Commissioner Tom Landwehr said the release “begins a critical phase” for the PolyMet project as the public gets its chance to impact the process.

“I am inviting Minnesotans to participate in the environmental review process by reviewing the document and providing thoughtful, informed input on the environmental analysis during the public comment period,” Landwehr said in a statement.

Polymet’s proposal includes the construction of two wastewater treatment plants, liner systems to house temporary wastewater stockpiles, groundwater containment systems and other measures.

Critics of the project, though, note it could lead to water pollution for 500 years or more at the mine site near Babbitt, and that ongoing water treatment would be necessary. They’ve also said the project could serve as a gateway for similar mining projects located in the same watershed as the federally protected Boundary Waters Canoe Area Wilderness.

The report notes that the project wouldn’t affect the BWCA, and focuses on wetlands near the proposed targeted areas and the Partridge and Embarrass rivers, which flow into the St. Louis River and then Lake Superior.

The report notes that based on a 90 percent probability, modeling predicted that pollutants from the mine wouldn’t exceed the state’s water quality evaluation criteria, with the exception of aluminum and lead. The levels of those two elements would increase in nearby waters, including the Embarrass River watershed, not because of discharges from the plant, but as a side effect of the project, the report says.

After the public meetings and the comment period, the regulatory agencies will work to address comments and answer questions raised.

At some point in 2014, the agencies will make a decision on whether the environmental review is “adequate” or not. If so, the company then will move into the permitting stage, seeking about a dozen different permits for state and federal agencies to start mining, drain wetlands and other actions.

PolyMet hopes to get those permits late in 2014, then quickly secure loans from banks to start construction.

PolyMet already has spent $150 million of shareholder money to get to this point and would spend another $450 million to build the mine and refurbish the old LTV taconite mine processing center for basic copper/nickel ore processing. The hydrometallurgical plant would cost another $200 million.

John Welbes contributed to this report.