MADISON, Wis. — State regulators have approved plans for a $700 million power plant on the shores of Lake Superior despite conservationists' concerns that the facility will harm the environment.

The Wisconsin State Journal reports that the state Public Service Commission voted 2-1 on Thursday to approve a permit for the Nemadji Trail Energy Center in Superior. The plant will be jointly owned by La Crosse-based Dairyland Power Cooperative and Duluth, Minnesota-based Minnesota Power. Plans call for the plant to use natural gas to produce 625 megawatts' worth of power.

The utilities argue that the plant will help them move away from coal-fired power generation. But environmental groups insist the companies should find cheaper and cleaner options than a plant that will produce millions of tons of heat-trapping gases. The Sierra Club said the plant will be "an environmental and economic disaster."

The Wisconsin Department of Natural Resources also has expressed concerns about the plant's impacts, including erosion, wetland loss and groundwater depletion.

Natural gas plants produce only about half as much carbon dioxide as coal-fired plants, but mining and transporting natural gas can release far more potent heat-trapping gases.

Commission Chairwoman Rebecca Valcq voted against the project, citing the potential environmental damage. But Commissioners Mike Huebsch and Ellen Nowak, who were both appointed by former Republican Gov. Scott Walker, voted for the facility, saying the DNR would ensure protection of the environment.

The project still faces obstacles in Minnesota. An appeals court in that state in December revoked Minnesota Power's authorization to invest in the plant, ruling regulators must consider environmental damage.

The Minnesota Public Utilities Commission voted 3-2 to approve Minnesota Power's role in the deal, even though a judge determined the utility could meet its needs more cheaply using renewable generation. The PUC said an environmental review wasn't needed because the plant would be built in Wisconsin.