The Environmental Protection Agency (EPA) has overturned the State of South Dakota's approval of the massive Big Stone II coal-fired power plant. The EPA's decision comes after the state failed to require state-of-the-art pollution controls for the coal plant that would address concerns about harmful soot, smog and global warming pollution.

This decision likely spells the end of Otter Tail Power's Big Stone II coal plant. At a minimum, Otter Tail Power will have to go back to the drawing board and redesign the project to incorporate the best and maximum available control technology for pollution like soot and smog. Sierra Club and Clean Water Action will be pushing for EPA to set limits also for carbon dioxide, the main contributor to global warming.

The permit decision extends protections beyond air pollution. The proposed Big Stone II coal plant would draw millions of gallons of water a day from Big Stone Lake-the headwaters of the Minnesota River. The Minnesota River is already heavily polluted with mercury. Coal plants are recognized as the leading source of this pollution.

With coal-fired power plants accounting for almost 30% of our nation's carbon dioxide emissions, burning less coal and investing in clean energy such as wind and solar instead is a common sense approach to helping meet global warming pollution reduction goals. The proposed Big Stone II 500-megawatt coal plant would have emitted more than 4 million tons of global warming pollution annually.

As the first major coal plant decision by the EPA since President Obama took office, this decision signals that the dozens of other coal plant proposals currently in permitting processes nationwide will face a new level of federal scrutiny. Sierra Club and Clean Water Action have been working to stop the Big Stone II project and ramp up clean energy investments in for more than three years.