Skip to main content

Permitting Requirements for Nonattainment Areas in Wisconsin

Areas that currently are or have been designated as being in "nonattainment" of a national ambient air quality standard (NAAQS) have more restrictive permitting requirements, and sources in those areas may be subject to more stringent regulations known as Reasonably Available Control Technology (RACT) standards. This page shows current Wisconsin nonattainment areas and summarizes the applicable permitting requirements for major sources of emissions within these areas. It also contains information about nonattainment area history to assist in determining RACT applicability for specified sources of nitrogen oxides (NOx) and select source categories of volatile organic compounds (VOC). The contents of this page are intended to provide a general overview of the applicable requirements. For more detailed information about RACT applicability, state permitting regulations or for questions related to a specific permit, contact the Air Management Program.

Interactive Map

Click on a county below for a summary of applicable permitting requirements based on nonattainment area designations. The map also provides relevant information for determining NOx RACT applicability for all sources and VOC RACT applicability for the following source categories: miscellaneous industrial adhesives (s. NR 422.128), plastic parts coatings (s. NR 422.084), and metal parts coatings (s. NR 422.151).

Please note: Graphical representations of attainment/nonattainment areas are approximate. For the most precise rule applicability information, type a specific address into the search bar on the map and then click on the map.

Explanation of Information Provided in the Map Legend

Major Emission Sources

Major emission sources for construction permitting purposes in areas that meet or attain the NAAQS are covered by the prevention of significant deterioration (PSD) permitting program. In contrast, major emission sources in nonattainment areas are covered by the nonattainment new source review (NNSR) permitting program.

In general, the NNSR program is more stringent than the PSD program because the goal of NNSR is to accommodate business expansion while improving air quality to attain the NAAQS. The emissions threshold for determining whether a source is subject to major source permitting is usually lower for NNSR than PSD. Projects covered by PSD are required to control emissions to a level defined as best available control technology (BACT), which allows consideration of economic feasibility of the controls. However, projects covered by NNSR are required to control emissions to the level defined as lowest achievable emission rate (LAER), which does not consider economic feasibility.

Major construction covered by NNSR also requires the permit applicant to offset the project's emissions according to a ratio that depends on the severity of nonattainment. Permit applicants can use internal offsets by establishing emission reductions from their own operations, or an applicant can use emission reduction credits. The offsets must represent surplus, permanent, quantifiable and federally enforceable emissions reductions.

Based on nonattainment status, the map above shows which permitting program currently applies in each area in Wisconsin, along with the associated major source threshold and offset ratio (as applicable).


Nitrogen oxides (NOx) RACT requirements apply to specified categories of equipment at facilities located in certain areas that are or have been classified as Moderate, Serious, Severe, or Extreme, nonattainment and emit NOx above an applicability threshold. The level of nonattainment classification determines the applicability threshold. More information on emission regulations and applicability is available on the NOx RACT page.

VOC RACT for Industrial Adhesives and Plastic and Metal Parts Coatings

Some VOC RACT requirements apply to specific facility types located in areas that are currently or were previously classified as Moderate or higher nonattainment for ozone and emit VOCs above an applicability threshold. The facilities subject to these requirements conduct operations using adhesives (s. NR 422.128), plastic parts coatings (s. NR 422.084), or metal parts coatings (s. NR 422.151). Additional VOC RACT rules covering other source categories also apply throughout the state. More information on regulations and applicability can be found on the VOC RACT page.

More information

Refer to air permit options for more information about construction permits.

Contact Information

For more information on major source permitting thresholds, contact:

Kristin Hart
Air Permits and Stationary Source Modeling Section Chief

For more information on state implementation plans (SIPs), control strategies and current air quality, contact:

Jason Treutel
Air Quality Planning and Standards Section Chief