FILE - The Gibson Power Plant operates April 10, 2025, in Princeton, Ind. (AP Photo/Joshua A. Bickel, File)
FILE - The Warrick Power Plant, a coal-fired electricity-generating station, operates, April 8, 2025, in Newburgh, Ind. (AP Photo/Joshua A. Bickel, File)
(Editorial Note: Part 423 of a series of further development in the early days that impacted Franklin County. Sources: History of a Valley, ed…
Mary Hess displays air quality data on the IQAir app on her phone Tuesday, April 8, 2025, in Dale, Ind. (AP Photo/Joshua A. Bickel)
Abbie Brockman, right, goes through the results of a water quality test with colleague Karen LaMar, left, Thursday, April 10, 2025, in Leopold, Ind. (AP Photo/Joshua A. Bickel)
The Warrick Power Plant operates Tuesday, April 8, 2025, in Newburgh, Ind. (AP Photo/Joshua A. Bickel)
Mary Hess displays an air monitor outside her home Tuesday, April 8, 2025, in Dale, Ind. (AP Photo/Joshua A. Bickel)
The Rockport Power Plant operates near a group of mobile homes Friday, April 11, 2025, in Rockport, Ind. (AP Photo/Joshua A. Bickel)
Eliza Ethridge, 5, holds her nebulizer Thursday, April 10, 2025, in Evansville, Ind. (AP Photo/Joshua A. Bickel)
A bulldozer moves coal Thursday, April 10, 2025, in Princeton, Ind. (AP Photo/Joshua A. Bickel)