Wisconsin's Anti-Ozone Plan Wins EPA Nod of Approval
Published Date: 4/2/2026
Proposed Rule
Summary
The EPA is proposing to approve Wisconsin’s plan to keep ozone pollution in check in Kenosha, Milwaukee, and Sheboygan areas by 2023. This plan includes rules for car emissions checks, new pollution controls, and progress goals to keep the air cleaner. If approved, these changes help protect public health without adding big costs, and folks can comment until May 4, 2026.
Analyzed Economic Effects
4 provisions identified: 2 benefits, 2 costs, 0 mixed.
15% Ozone-Precursor Reductions Approved
The EPA is proposing to approve Wisconsin's Moderate area reasonable further progress (RFP) plan showing at least a 15% reduction in ozone precursor emissions between the 2017 base year and the 2023 milestone year for the Kenosha County area, the Milwaukee area, and Sheboygan County. This approval recognizes that the State's plan meets the 15% RFP requirement and supports cleaner air and public-health protection in those areas.
2023 Motor-Vehicle Emissions Budgets Set
The State submitted 2023 motor vehicle emissions budgets (Budgets) for transportation conformity: Kenosha County VOC 0.89 tpd and NOX 1.22 tpd; Milwaukee Area VOC 10.77 tpd and NOX 14.80 tpd; Sheboygan County VOC 0.56 tpd and NOX 0.95 tpd. Wisconsin included an assumed VMT increase of 7.5% for Kenosha and Milwaukee and 15% for Sheboygan for 2023. If approved, federally funded transportation projects in these areas must conform to these 2023 Budgets.
Nonattainment New Source Review Applies
EPA is proposing to approve Wisconsin's nonattainment new source review (NNSR) program for the Kenosha County area, the Milwaukee area, and Sheboygan County. The NNSR program includes the Moderate-area requirement for greater emissions offsets for new or modified major stationary sources in nonattainment areas.
Motor Vehicle I/M Program Certified
Wisconsin is certifying its existing motor vehicle inspection and maintenance (I/M) program meets the EPA's Enhanced performance standard (analysis year 2025) and the State says the program satisfies the Basic I/M requirements for the Kenosha County and Milwaukee areas under the 2015 ozone NAAQS. Vehicle owners in the affected nonattainment areas will remain subject to the SIP-approved I/M testing regime.
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Key Dates
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