Approval and Promulgation of Implementation Plans-Pinal County (Part); West Pinal, AZ PM10 Nonattainment Area; Moderate Area, Serious Area, and Section 189(d) Plan for Attainment of the 24-Hour PM10 Standard
Key claim: EPA is proposing to approve Arizona’s air-quality plan for the West Pinal County PM10 nonattainment area, including motor-vehicle emissions budgets, and would set December 31, 2026 as the date the area must meet the 24-hour PM10 standard.
Abstract
(Proposed Rule · Environmental Protection Agency) The U.S. Environmental Protection Agency (EPA) is proposing to approve a state implementation plan (SIP) revision submitted by the State of Arizona to meet Clean Air Act (CAA or “Act”) requirements applicable to the Pinal County (Part); West Pinal PM10 nonattainment area (“West Pinal County PM10 Nonattainment Area”). The EPA is proposing to find that the submitted SIP revision meets all applicable “Moderate” area, “Serious” area, and CAA section 189(d) requirements for the PM10 national ambient air quality standards (NAAQS). Additionally, the EPA is proposing to approve the PM10 motor vehicle emissions budgets included with the SIP revision for transportation conformity purposes. The EPA is also starting the adequacy process for these budgets. Our proposed approval of the SIP revision would establish an attainment date of December 31, 2026, for the area.
Why this matters
PM10 nonattainment plans like West Pinal’s set the practical rules that constrain local dust-generating activities (agriculture, unpaved roads, construction) and define the motor-vehicle emissions budgets transportation agencies must conform to. EPA’s approval locks in a 2026 attainment deadline, meaning further federal consequences — including possible reclassification or sanctions — hinge on whether monitored PM10 falls below the 24-hour standard on time.