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Next to a national wildlife refuge, Indiana’s Gibson Lake provides a prime fishery for bass and an attractive rest spot for hundreds of species of birds, including endangered least terns.
But the manmade lake, built by one of the world’s largest coal-fired power plants to hold its wastewater, contains high levels of selenium that jeopardize the birds and rendered fish unsafe to eat.
Selenium is an essential nutrient, but in wildlife and people excess amounts can be dangerous. Now the U.S. Environmental Protection Agency is preparing a new regulation that would require more than 600 coal-fired power plants to clean up—perhaps even eliminate—wastewater discharged into lakes, rivers and other waterways.
The new national standards, scheduled to be unveiled in 2012, will replace a patchwork of state regulations that EPA officials say are too lax to protect fish and wildlife from toxic metals and other elements, particularly selenium, in the power plants’ wastewater. Some states allow the plants to emit selenium at levels hundreds of times higher than EPA’s water-quality standards, while others don’t even require monitoring for it.
High selenium levels can deform or kill fish and birds, sometimes even wiping out species.
“For selenium, that boundary between … the optimum amount that you actually need and stepping over that line to toxicity is just a knife edge,” said Marjorie Brooks, an assistant professor in the zoology department at the University of Southern Illinois and co-editor of an upcoming book about selenium in aquatic environments. “We do need to be really vigilant about how much is there and how much is leaching into the system.”
Power plants that burn coal require large volumes of water for their cooling towers so they are typically situated close to lakes and rivers, said C. Richard Bozek, director of environmental policy at the Edison Electric Institute, a trade association of shareholder-owned electric companies.
The EPA has regulated the industry’s wastewater since 1982 for other contaminants, but regulation of selenium and metals has been left to individual states.
In September, after studying some coal-fired power plants, the EPA concluded that “current regulations have not kept pace with changes that have occurred in the electric power industry over the last three decades.”
The study “revealed significant concerns around metals from discharge from these power plants,” said Mary Smith, director of the engineering and analysis division of the EPA’s Office of Water.
Duke Energy’s Gibson Generating Station is one of many plants that have drawn the attention of environmental agencies. Rather than rely on the nearby Wabash River for its plant, which serves Indianapolis and nearby areas, Duke Energy constructed a 3,000-acre lake in the 1970s to use as a cooling pond and to store its waste. The lake was closed to fishing in 2007 because selenium concentrations in the fish exceeded levels safe for subsistence fishing.