Review of New Source Performance Standards for Stationary Combustion Turbines and Stationary Gas Turbines

The Environmental Protection Agency (EPA) is proposing amendments to the Standards of Performance for new, modified, and reconstructed stationary combustion turbines and stationary gas turbines based on a review of available control technologies for limiting emissions of criteria air pollutants. This review of the new source performance standards (NSPS) is required by the Clean Air Act (CAA). As a result of this review, the EPA is proposing to establish size-based subcategories for new, modified, and reconstructed stationary combustion turbines that also recognize distinctions between those that operate at varying loads or capacity factors and those firing natural gas or non-natural gas fuels. In general, the EPA is proposing that combustion controls with the addition of post-combustion selective catalytic reduction (SCR) is the best system of emission reduction (BSER) for limiting nitrogen oxide (NO<INF>X</INF>) emissions from this source category, with certain, limited exceptions. Based on the application of this BSER and other updates in technical information, the EPA is proposing to lower the NO<INF>X</INF> standards of performance for most of the stationary combustion turbines included in this source category. In addition, for new, modified, and reconstructed stationary combustion turbines that fire or co-fire hydrogen, the EPA is proposing to ensure that those sources are subject to the same level of control for NO<INF>X</INF> emissions as sources firing natural gas or non-natural gas fuels, depending on the percentage of hydrogen fuel being utilized. The EPA is proposing to maintain the current standards for sulfur dioxide (SO<INF>2</INF>) emissions, because after reviewing the current SO<INF>2</INF> standards, we propose to find that the use of low-sulfur fuels remains the BSER. Finally, the Agency is proposing amendments to address specific technical and editorial issues to clarify the existing regulations.