On June 15, 2005, the EPA revoked the 1-hour ambient air quality standard for ozone for all areas of the nation, except the 8-hour ozone nonattainment Early Action Compact Areas. The EPA retained the former 1-hour ozone designations and classifications as of June 15, 2004 in subpart C of 40 CFR Part 81 solely for purposes of the anti-backsliding provisions of 40 CFR 51.905. In a series of federal circuit court cases, the EPA was directed to expand the scope of the anti-backsliding provisions in Section 172(e) of the CAA [42 USC 7502(e)] that applied to areas not meeting the 1-hour standard.
In Wisconsin, based on 2003 through 2005 monitoring data, the Milwaukee-Racine ozone nonattainment area again attained the 1-hour ozone standard, two years ahead of mandated 2007 attainment date. The area continues to measure attainment of the 1-hour ozone standard.
The DNR redesignated Milwaukee-Racine nonattainment area (Kenosha, Milwaukee, Racine, Ozaukee, Washington and Waukesha Counties) to attainment of the 1-hour standard under state law. (See below under “Implementation/Conformity).
42 USC Sec. 7409 (CAA) – National Primary and Secondary Ambient Air Quality Standards: December 31, 1970. This section of the CAA provides the EPA authority to promulgate National Ambient Air Quality Standards (Primary and Secondary) or, NAAQS.
40 CFR Part 52 – Approval and Promulgation of Implementation Plans; Wisconsin; July 2, 2002.
WDNR – Wisconsin’s 2000 SIP Submittal: “Attainment Demonstration for Ozone for the Year 2007: The Phase 3 Attainment State Implementation Plan for the Eastern Wisconsin Nonattainment Areas”; Dec. 22, 2000.
40 CFR Part 52 – Approval and Promulgation of Implementation Plans; Wisconsin; June 20, 2003.
Health and Environmental Affects
EPA – Health and Environmental Effects of Ground-Level Ozone: July 17, 1997.
NR 437 – Voluntary Emission Reduction Registry Rule (state rule): Effective November 1, 2002.