ST. PAUL, Minn. (AP) - Gov. Mark Dayton says his administration on Thursday will announce its long-awaited decision on whether it will approve the final environmental review for the proposed PolyMet copper-nickel mine in northeastern Minnesota.

In an interview on Tuesday, Dayton declined to say what the decision will be.

The decision will come from the Department of Natural Resources. On the outskirts of the Governor's Water Summit on Saturday, DNR Commissioner Tom Landwehr reaffirmed previous statements that he expected to certify the review as "adequate" unless unexpected new issues emerged.

While PolyMet's supporters tout the hundreds of jobs the project would create, environmental groups have challenged assurances that the minerals can be mined without serious risks to waters downstream of the mine near Babbitt and processing plant near Hoyt Lakes.