American Electric Power agreed on Monday to stop burning coal at three of its power plants and lower sulfur dioxide emissions across its operations in a settlement with the Environmental Protection Agency and a coalition of environmental groups.

Environmentalists are claiming the settlement as a major climate victory and a blow to coal power.

“This agreement is only the latest sign of progress as our country continues to transition away from dirty, dangerous, and expensive coal-fired power plants,” said Sierra Club spokeswoman Jodi Perras.

But the company, one of the largest electric power utilities in the country, had already planned to retire two of its power plants, AEP spokeswoman Melissa McHenry told The Washington Examiner. AEP has planned for some time to retire the Muskingum River Power plant in Ohio as part of its plan to comply with the EPA’s Mercury and Air Toxics Standards, and requested in December to retire its Big Sandy plant in Kentucky as well.

“It is incorrect to say that this agreement results in the closure of three AEP coal plants,” McHenry said.

Monday’s settlement, initiated by AEP, was actually a small victory for the company. The decision is a modification of a 2007 agreement to reduce emissions and stop burning coal at those plants. AEP on Monday agreed to cap its sulfur dioxide emissions at a lower level and refuel or retire its Tanners Creek, Ind., power plant in addition to the other two. The company also secured permission to use less expensive technology in reducing sulfur dioxide at its Rockport, Ind., plant.

The newer technology comes in at one-fifth the cost of the older technology, which will mean significant savings for customers in Indiana, McHenry said.

That didn’t stop environmentalists from declaring the case as a success in their fight against coal.

“Today’s agreement will protect public health, reduce the threat of climate disruption, and create a cleaner environment for families in Indiana, Ohio and Kentucky,” said Perras.

The EPA and a coalition of environmentalists originally sued the company in 1999 for allegedly violating the Clean Air Act, saying AEP failed to obtain proper permits and avoided installing technology that reduced air pollution.