Partial Approval and Partial Disapproval of Air Quality State Implementation Plans; Arizona; Prevention of Significant Deterioration Infrastructure Requirements for the 2012 Fine Particulate Matter National Ambient Air Quality Standard
Key claim: EPA proposes to approve Arizona’s 2012 PM2.5 NAAQS PSD infrastructure SIP elements for ADEQ, Maricopa County, and Pinal County while disapproving the Pima County portion.
Abstract
(Proposed Rule · Environmental Protection Agency) The Environmental Protection Agency (EPA) is proposing to partially approve and partially disapprove a revision to the Arizona State implementation plan (SIP) as meeting the requirements of the Clean Air Act (CAA) for the implementation, maintenance, and enforcement of the 2012 fine particulate matter (PM2.5) national ambient air quality standard (NAAQS or “standards”). The EPA is proposing to approve the portions of Arizona’s submission addressing prevention of significant deterioration (PSD) requirements in the permitting jurisdictions of the Arizona Department of Environmental Quality (ADEQ), Maricopa County Air Quality Department (MCAQD), and Pinal County Air Quality Control District (PCAQCD). The EPA is proposing to disapprove the portions of the Arizona submission addressing PSD requirements in the Pima County Department of Environmental Quality (PDEQ) permitting jurisdiction.
Why this matters
Infrastructure SIPs implement the structural Clean Air Act obligations (including PSD permitting for new/modified major sources) that every state must satisfy after a NAAQS is set, regardless of attainment status. A partial disapproval for Pima County could trigger a federal implementation plan backstop or sanctions clock for that jurisdiction, while the approvals lock in state PSD authority elsewhere in Arizona — shaping permitting timelines and costs for new industrial sources statewide.