EPA Revamps Rules to Tame Nitrogen Oxides from Gas Turbines
Published Date: 1/15/2026
Rule
Summary
The EPA is updating rules for stationary combustion and gas turbines to cut pollution, especially nitrogen oxides (NOX). These changes affect new, modified, or rebuilt turbines, grouping them by size, fuel, and use, and set clearer pollution controls. The new rules kick in January 15, 2026, and some small or temporary turbines get easier requirements, helping businesses save money while keeping the air cleaner.
Analyzed Economic Effects
4 provisions identified: 1 benefits, 2 costs, 1 mixed.
New NSPS Apply to Recent Turbine Projects
The EPA’s final rule creates a new NSPS subpart (KKKKa) that applies to stationary combustion turbines and stationary gas turbines that began construction, modification, or reconstruction after December 13, 2024. The final rule is effective January 15, 2026, so turbines that started those activities after December 13, 2024 must meet the updated standards once the rule is in effect.
Turbines Grouped into Size/Use Subcategories
The EPA is establishing subcategories for new, modified, or reconstructed stationary combustion turbines based on size, rates of utilization, design efficiency, and fuel type. This means owners/operators will face different emission control requirements depending on which subcategory their turbine falls into.
NOX Controls: Combustion Controls; SCR for One Group
The EPA determined that combustion controls are the best system of emission reduction (BSER) for NOX for most new, modified, or reconstructed stationary combustion turbines. For one specific subcategory, the EPA determined BSER is combustion controls with the addition of selective catalytic reduction (SCR).
Easier Rules for Temporary and Small Turbines
The EPA added a subcategory for stationary combustion turbines used in temporary applications and is exempting certain sources from title V permit requirements. The preamble says some small or temporary turbines get easier requirements, which can reduce compliance costs for those businesses.
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Key Dates
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