MINNEAPOLIS — Federal and state regulators have conceded the possibility that some potentially polluted water from the proposed PolyMet copper-nickel mine could flow toward the Boundary Waters Canoe Area Wilderness.

As a result, the U.S. Environmental Protection Agency is urging state officials and propose a solution in the final version of the environmental review of the project, which is due out later this year.

Environmentalists and Indian tribes said documents show the project’s water model is badly flawed, and that the review understates the environmental risk. The problem, identified by scientists who work for the Minnesota Chippewa Tribe, was first reported by an Ely weekly newspaper, the Timberjay.

PolyMet Corp. said it’s confident that its water modeling is valid, and that questions will be addressed by regulators.