On October 22, 2020, Andrew Wheeler, EPA Administrator, signed the final rule adopting the “project emissions accounting” approach to Step1 of the Prevention of Significant Deterioration (PSD) and major nonattainment area new source review (NNSR) programs. The final rule provides that both increases and decreases resulting from a proposed project can be considered in Step 1 of the major NSR modification applicability test, provided that all changes are part of the same “project” as EPA had defined that term in the 2018 reconsideration of “project aggregation.”
