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Incorporating Federal “Tailoring” Rules into Wisconsin’s Major Source Permitting Rules

Most Recent Action

EPA is proposing to approve revisions to the Wisconsin SIP, Dec. 28, 2012


The EPA has adopted GHG rules that will subject sources of GHG emissions to regulations under the existing major source permitting program. This rule will subject thousands of small and previously unregulated sources to permitting requirements, so the EPA has found it necessary to also propose to adopt another rule to set higher applicability thresholds in order to avoid unduly burdening many small sources with the cost of meeting permitting requirements.

A revision of existing state major source permitting rules consistent with this federal action is necessary to ensure that smaller sources will not be subject to major source permitting requirements for GHG emissions in Wisconsin.

The Natural Resources Board approved an emergency rule to incorporate the federal tailoring rules into Wisconsin’s rulesat its December 8, 2010 meeting.

The emergency rule expires on July 13, 2011, so the DNR is also promulgating a permanent rule.



In Massachusetts v. EPA, 549 US 497, the Supreme Court found that GHG are air pollutants covered by the Clean Air Act and directed the EPA to make a finding as to whether emissions of these gases from new motor vehicles cause or contribute to air pollution which may be reasonably anticipated to endanger public health or welfare. On December 7, 2009 the EPA made their official finding, referred to as the “endangerment finding” establishing the prerequisite to regulating GHG emissions from motor vehicles.

Subsequent to this finding, the EPA and the US DOT finalized regulations on April 1, 2010 establishing standards for GHG emissions from new light duty motor vehicles, starting with model year 2012.

The combined effect of the Supreme Court decision and the finalized motor vehicle rule adds GHG to the list of pollutants that are regulated under the Clean Air Act. This in turn subjects stationary sources (i.e., electric utilities, factories, small business, etc.) to the prevention of significant deterioration (PSD) & Title V permitting programs if their GHG emissions exceed established threshold amounts.

Section 285.11(16), Wis. Stats., requires the DNR to promulgate rules that specify the amounts of emissions that result in a stationary source being classified as a major source. This section requires the rules to be consistent with the Clean Air Act.

Section 285.11(1), Wis. Stats., gives the DNR authority to promulgate rules consistent with ch. 285, Wis. Stats.

Section 227.11(2)(a), Wis. Stats., gives state agencies general rulemaking authority.

Section 227.14(1m)(b), Wis. Stats., allows agencies to use the format of federal regulations in preparing a proposed rule if it determines that all or part of a state environmental regulatory program is to be administered according to standards, requirements or methods which are similar to standards, requirements or methods specified for all or part of a federal environmental program.

Section 227.24(1)(a), Wis. Stats., gives agencies the authority to promulgate a rule as an emergency rule without complying with notice, hearing, and publication requirements under ch. 227, Wis. Stats., if necessary for the preservation of public welfare.


Proposed Standards

Wisconsin sources became subject to permit and emission control requirements on January 2, 2010. As the statutes and code exist right now, Wisconsin sources will not benefit from the federal tailoring rule limiting applicability under air permit and emission control regulations.

The emergency rules and the proposed permanent rules would revise the administrative code to make it consistent with the new federal rule. Specifically, the proposed rules:

  • Define greenhouse gases as the six pollutants listed in the endangerment finding (carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride);

  • Define how to calculate a carbon dioxide equivalency (CO2e) for the six pollutants;

  • Define a major source of GHG emissions at 100,000 tons per year CO2e;

  • Define a significance level for PSD permitting at 75,000 tons per year CO2e; and

  • Establish a two step phased-in implementation schedule.

In addition to the federal requirements above, the rules propose to:

  • Define an inclusion level for emission sources that will be included in a Title V permit; and

  • Establish the global warming potential for the greenhouse gases being regulated.


Related Documents

Wisconsin’s Response to the EPA’s request that the state allow the EPA to regulate PSD and part 70 title V permitting programs.

Emergency Rulemaking Order, December 15, 2010

Permanent Rule Documents:

Statement of Scope

Rules Proposed for Hearing, Background Memo and Fiscal Estimate

Public Hearing Notice

Clearinghouse Review of Rule

Report to the Legislature

Final Proposed Rulemaking Order

EPA Response:

EPA is proposing to approve revisions to the Wisconsin SIP, Dec. 28, 2012