proofread " Evaluating the installation of Selective Catalytic Reduction (SCR) systems on each turbine or through a combined Heat Recovery Steam Generator (HRSG) path offers significant benefits, including the reduction of nitrogen oxides (NOx) emissions to 2-5 ppmvd, which leads to substantial ozone season mass reductions and savings in emissions allowances. This retrofit not only enhances local air quality but also ensures the facility is prepared for anticipated stricter regulatory requirements, such as revisions to state Implementation Plans (SIPs) or updates to the Good Neighbor Plan. When implementing SCR, it is crucial to select the appropriate catalyst typeeither high-temperature based on the exhaust temperature profile, while incorporating ammonia slip monitoring (typically 5 ppm) and effective reagent handling controls. Additionally, installing oxidation catalysts downstream of the turbine or SCR can achieve over 90% reductions in carbon monoxide (CO) and volatile organic compounds (VOCs), including formaldehyde, thereby mitigating emissions during startup and low-load conditions and aligning with common Best Available Control Technology (BACT) standards