The Indiana Department of Environmental Management issued the new plant's air permits in 2008 and, importantly, under the settlement they remain approved with no changes. The dispute centered on technical issues surrounding the permits that enabled the company to build and operate the plant. The settlement also addresses deadlines for retiring units at Duke Energy's Wabash River Station in West Terre Haute. Prior to the settlement, the company had announced it planned to retire four, 1950s-vintage units totaling 350 megawatts at the station by the 2015 federal mercury rule deadline. In the agreement, the company agrees to complete the retirements by the compliance deadline or, if the mercury rule is vacated or delayed, by June 1, 2018, whichever occurs first.