EPA finalized new source performance standards for stationary combustion and gas turbines, determining that basic combustion controls are the best system of emissions reductions (BSER) for all but new, large turbines with 12-month capacity factors greater than 45 percent. For this select category, EPA requires combustion controls and selective catalytic reduction (SCR), which was recommended for all stationary combustion turbines under the Biden administration. EPA estimated its final ruling will reduce nitrous oxide emissions by significantly less than the proposed rule under Biden, and declined to estimate the monetary benefits of improved public health.