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Pollutant-Specific Significant Contribution Finding for GHG Emissions from New EGUs, and Process for Determining Significance of Other NSPS Source Categories

January 7, 2021 - EPA is providing a framework for criteria for making a significant contribution finding for greenhouse gas emissions from a source category, for the purpose of regulating those emissions under section 111(b) of the Clean Air Act. The framework sets an emissions threshold of 3 percent of total gross U.S. GHG emissions (as measured in carbon dioxide equivalent, i.e., CO2e) from a stationary source category as the primary criterion in making a pollutant-specific significance determination. This provides certainty regarding EPA’s process and gives regulated entities insight into EPA’s approach to making a determination of significance under this part of the Act.