The EPA proposes to conduct a Clean Air Act-required technology review of the new source performance standards (NSPS) for stationary combustion turbines under 40 CFR part 60, subpart KKKK. This technology review will include an analysis of criteria pollutant emissions, including but not limited to nitrogen oxides (NOx). The EPA previously proposed standards of performance for affected stationary combustion turbines in February 2005, and, in July 2006, finalized emission limits for NOx and sulfur dioxide (SO2). Subpart KKKK currently applies to stationary combustion turbines with a heat input at peak load equal to or greater than 10.7 gigajoules or 10 MMBtu per hour. The EPA has entered into a consent decree for the proposal of the findings of its completed review of subpart KKKK to be signed in November and published in December 2024.