Comment submitted by Persistence Analytics Group LLC on the Proposed Approval of the Detroit, Michigan 2015 8-Hour Ozone Determination of Attainment by the Attainment Date

Persistence Analytics Group LLC submits this comment regarding EPA–R05–OAR–2026–3070, Air Plan Approval; Michigan; Determination of Attainment by the Attainment Date for the 2015 Ozone Standards. PAG does not oppose EPA’s use of the Clean Air Act exceptional-events framework where the statutory and regulatory criteria are met. PAG submits this comment to emphasize implementation integrity. EPA’s proposed determination for the Detroit area relies on the exclusion of certain wildfire-influenced ozone monitoring data from June and July 2023. EPA states that EGLE submitted an exceptional-events demonstration on February 19, 2026, and that EPA concurred on March 24, 2026. That may be legally permissible. But because the resulting attainment determination affects regulatory status, public-health communication, compliance planning, permitting expectations, transportation planning, economic development, and long-term infrastructure assumptions, the exclusion of data must be transparent, reproducible, and verifiable. PAG recommends that EPA include in the final action a clear implementation-verification summary addressing: 1. Which specific monitor-day values were excluded. 2. What evidence supports the conclusion that wildfire smoke materially influenced those ozone concentrations. 3. How the design values change with and without the exceptional-events exclusions. 4. Whether public-health risk communication remains accurate even if the area is deemed to have attained the standard. 5. How EPA will distinguish exceptional-event-driven attainment from durable air-quality improvement. 6. Whether local, state, transportation, industrial, and public-infrastructure planning assumptions should rely on the adjusted attainment determination. 7. What future monitoring, reporting, and public disclosure will confirm whether attainment persists without extraordinary event adjustments. The key issue is not only whether Detroit technically attained the 2015 ozone NAAQS after excluding exceptional-event-influenced data. The key issue is whether the public, regulators, businesses, communities, and infrastructure planners can understand what the determination means — and what it does not mean. Exceptional-event exclusions should not become assumption shortcuts. They should be supported by decision-grade evidence, public transparency, and continued monitoring. PAG recommends that EPA finalize any attainment determination with a plain-language statement explaining: what data were excluded, why the exclusions were justified, what the unadjusted data showed, what the adjusted data show, and what ongoing obligations or monitoring expectations remain. Attainment is not only a legal determination. It is a public-health, infrastructure, economic, and planning signal. That signal must be verified. Respectfully submitted, Neil P. Osnato Founder Persistence Analytics Group LLC | United Grid National Security & Infrastructure Risk Analytics Demand Durability | Grid Stress | Load Integrity SAM.gov Registered Vendor UEI: D3VYU39H6DX9 | CAGE: 19T34 D-U-N-S: 142849930 neil@persistenceanalyticsgroup.com 609-464-9055 https://persistenceanalyticsgroup.com/