Federal Implementation Plan for Nonattainment New Source Review Program; Mojave Desert Air Quality Management District, California

The Environmental Protection Agency (EPA) is finalizing a Federal Implementation Plan (FIP) under the Clean Air Act (CAA) that consists of Nonattainment New Source Review (NNSR) rules for areas within the jurisdiction of the Mojave Desert Air Quality Management District (MDAQMD or "District") in which air pollutant concentrations are above specific National Ambient Air Quality Standards (NAAQS). The NNSR rules will apply to construction of new major stationary sources and major modifications at existing major stationary sources of air pollution. The FIP will be implemented by the EPA, unless and until it is replaced by an EPA-approved state implementation plan (SIP). In this action, the EPA is also responding to a September 5, 2024 decision of the United States Ninth Circuit Court of Appeals for the Ninth Circuit, which remanded the EPA's disapproval of a MDAQMD rule provision related to the calculation and generation of emissions offsets. This response again disapproves MDAQMD Rule 1304(C)(2)(d) and provides additional information to support that decision.