Xcel Energy Inc. has agreed to curb smokestack emissions at its giant coal-burning Sherco power plant in Becker, Minn., to settle a lawsuit alleging they caused haze over national parks in Michigan and Minnesota.
The settlement, which must be approved by a federal judge, would end a lawsuit filed in 2012 by six environmental groups against the U.S. Environmental Protection Agency. The suit sought to enforce rules under the U.S. Clean Air Act to protect visibility in Voyageurs National Park in Minnesota and Isle Royale National Park in Michigan.
"There are going to be visibility improvements," said Kevin Reuther, legal director for the Minnesota Center for Environmental Advocacy, a St. Paul environmental law firm that was part of the lawsuit.
Xcel, which intervened in the lawsuit, said a recent $50 million upgrade to controls known as scrubbers on two older generating units, and planned modifications to a newer generator will reduce the Sherco plant's sulfur dioxide (SO2) emissions by 50 percent by 2017.
"This leverages off an investment we have made at the Sherco facility that has recently been proven to achieve significant SO2 reductions," Jack Ihle, director of environmental policy for Xcel, said in an interview. "So we are using that performance to reach an agreement with the parties to reduce the emissions overall."
The National Parks Conservation Association and five other groups filed the lawsuit in U.S. District Court in Minnesota, citing a section of the federal Clean Air Act with special protections for national parks. Haze is mainly a visibility problem, obscuring pristine vistas in parks and wilderness that Congress wanted to preserve.
But Reuther said sulfur dioxide also plays a role in the formation of fine dusts that pose a risk to human health.
The U.S. Interior Department, parent agency of the National Park Service, declared in 2009 that Sherco units 1 and 2 were the source of air pollution affecting the parks. The EPA and Xcel have disputed that finding, and Ihle said Xcel doesn't concede its power plant is to blame.