The Sierra Club is targeting a southern Spencer County power plant in its campaign to close aging coal-fired power stations.
The environmental group says it has collected more than 1,000 signatures from Indiana Michigan Power customers urging the utility to replace half of the power generation at its Rockport plant with renewable energy sources.
A recent U.S. Environmental Protection Agency report shows the Ohio River plant released more than 5.9 million pounds of toxic pollution in 2014.
Indiana Michigan spokeswoman Melissa McHenry says the report is misleading because more than half of the 5.9 million pounds were from ash generated by burning coal.
She says the company plans to install new technology to control sulfur dioxide from the plant.