The U.S. Environmental Protection Agency (EPA) established the 2012 PM2.5 annual standard of 12 µg/m3 on January 13, 2013. The Clean Air Act (CAA) mandates the District to develop and submit an attainment plan for the 2012 annual PM2.5 standard to EPA.
EPA initially designated the District as Moderate nonattainment for the 2012 PM2.5 standard in 2015. The District submitted the 2016 PM2.5 Plan to address Moderate area requirements for the 2012 PM2.5 standard and to request to be reclassified to Serious nonattainment. EPA approved the Moderate Plan and reclassified the District to Serious nonattainment, effective December 2021.
The District adopted the Initial State Implementation Plan (SIP) Requirements for the 2012 Annual PM2.5 Standard on October 19, 2023, to fulfill the first portion of SIP elements required by the CAA for Serious PM2.5 nonattainment areas, including an updated emissions inventory, precursor demonstration, and the demonstration that BACM requirements continue to be satisfied in the Valley. Additionally, the District fulfilled Nonattainment New Source Review (NNSR) requirements through amendments to District Rule 2201 (New and Modified Stationary Source Review Rule) in April 2023.
The District adopted the 2024 Plan for the 2012 Annual PM2.5 Standard on June 20, 2024, to fulfill the remaining CAA requirements, including the final modeling analysis, attainment strategy and emission reduction commitments, reasonable further progress/quantitative milestones, and contingency measures. This Plan demonstrates expeditious attainment of the 2012 PM2.5 standard by 2030.
