MINNEAPOLIS — Clean air advocates, the U.S. Environmental Protection Agency, and a subsidiary of Xcel Energy have reached a settlement that will reduce emissions from the Sherco plant in Sherburne County.

The settlement was filed Friday in U.S. District Court.

The environmental groups say the agreement requires Northern States Power Co. to reduce sulfur dioxide emissions from two Sherco units by about 10,000 tons annually by October. Further reductions are required by 2017.

The groups sued the EPA and Northern States Power in 2012, saying pollution from the coal-fired Sherco plant near Becker is unhealthy and is a major contributor to haze that obscures the views at Voyageurs and Isle Royale national parks and the Boundary Waters Canoe Area.

There will be an opportunity for public comment before the settlement takes effect.