Judge backs Big Stone haze reduction upgrade

ST. PAUL, Minn. (AP) — A judge has backed a $489 million pollution-control upgrade for the 36-year-old Big Stone power plant in South Dakota.

The upgrade would cut haze-forming pollutants, bringing the plant into compliance with regulations to protect wilderness areas and national parks, including the Boundary Waters Canoe Area and Voyageurs National Park.

Four environmental groups are pushing to replace it with natural gas and renewable energy like wind power.

But the Star Tribune reports a Minnesota administrative law judge says it makes more financial sense to install the best available pollution controls.

The project still faces scrutiny by the Minnesota Public Utilities Commission and its counterparts in two other states. Big Stone is owned by Fergus Falls-based Otter Tail Power, NorthWestern Energy of Sioux Falls, S.D., and Montana-Dakota Utilities Co. of Bismarck, N.D.