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Air permit types for small businesses

Certain regulations are enacted to minimize the amount of pollution present in the air we breathe. For Wisconsin, both the U.S. Environmental Protection Agency and the state Department of Natural Resources implement and enforce a range of air pollution regulations.

Businesses with emissions of air pollution above certain thresholds must have an air pollution permit to construct, modify and operate. Knowing whether you need a permit, submitting an application, and operating under your air pollution permit is a complex process. Many small businesses may be exempt from needing permits, whether operation or construction permits or both. If you are not exempt but have relatively low emissions, you may be eligible for a registration permit. General permits are intended only for specific industries and have a simplified application process.


If your construction or modification project requires a permit, you must wait to begin any construction activities until the DNR has issued the final air permit.

Review the following information to help you determine how the air pollution permit requirements apply to your business. As you read through this information, it may be helpful to have the Air Program Acronyms (SB-101) list on hand. If you are exempt from needing an air permit, other air pollution requirements may apply. Review the Complying with regulations page for more information.

Getting started

How to get started on the air permit process

Federal and state laws require all air pollution sources in Wisconsin to have a permit unless the source is determined to be exempt. To get started, review the information under each tab here to understand the basics concerning the various permits applicable to small businesses, including application deadlines, definitions and who to contact for more assistance. Then go through the following steps:

Application process

Air permit application process

The air permit process is designed to be transparent. Almost all permit-related documents are open records, including applications, modeling analyses and permit drafts. Input from the public and the permit applicant is encouraged throughout the process and can affect the content of the permit.


Permit to construct, reconstruct or modify your business

A construction permit is required prior to beginning any construction, modification, expansion or replacement of an air pollution source. Once issued a construction permit, a company is allowed to perform that construction, modification, expansion or replacement and then operate the source for an initial trial period. Then the company is issued an operation permit which allows operation for extended periods. The trial period under a construction permit is used to test equipment and demonstrate compliance with permit conditions. The source may be entirely new or part of an existing facility. Administrative code requirements for construction permits are found in ch. NR 406, Wis. Adm. Code.

If you have a business that installed equipment after 1979 or recently started up certain equipment or activities and did not receive an air pollution construction permit for the equipment or activities, you may want to review the following documents to see if you are in compliance with the requirement to obtain a permit prior to construction, reconstruction or modification.

Fees for construction permits

The fee for a construction permit depends on the complexity of the permit review. An application fee of $7,500 must be submitted with any permit application, regardless of the complexity of the permit review. If the DNR decides a permit is required, the application fee will be deducted from the final permit review bill. If the final review fee is less than the application fee, the remainder will be refunded. If no permit is required, the application fee is refunded.

The cost for a construction permit varies depending on the facility and type of permit required. Some of the possible review costs may include:

  • $3,000 base fee for minor source review;
  • $800 per emission source, when two or more are reviewed;
  • $1,000 for an air quality analysis for a minor source or minor modification; and
  • $5,000 for expedited review of minor source (speeds up the process but is not required).

A full listing of the fees is found in NR 410, Wis. Adm. Code.

Construction permit waiver

A construction permit waiver can be issued to certain sources in situations where they can demonstrate undue hardship if the waiver is not granted. Undue hardship may result from adverse weather conditions, catastrophic damage of existing equipment, a substantial economic or financial hardship that may preclude the project, or another unique condition on a case-by-case basis.

The waiver request should detail the situation necessitating the request. There is also a $300 non-refundable fee required. Submittal of a complete construction permit application to the DNR is one condition of gaining approval of a waiver request.

How long until the permit is issued

After the application is complete, the DNR will prepare a preliminary decision document stating whether the permit application will be approved or denied. The document must be prepared within 90 days from the date the DNR considers the application complete for minor sources, or within 120 days for major sources. A 30‐day public participation period is required for each permit following the preliminary decision, and a public hearing may be held following the public participation period if requested or the level of public interest warrants.

For general questions about construction permits, contact your local DNR office.


Permit to operate a source of air pollution

Unless it is exempt, any company that has processes or activities that generate air pollution is required to obtain an Air Pollution Operation Permit. The operation permit covers all equipment and activities that result in air emissions. As a result of the Clean Air Act Amendments of 1990, many small businesses are required to obtain these air permits.

An Air Operation Permit is basically a contract between you, the DNR and the public. The permit is a legal document identifying all state and federal air pollution regulations that apply to your facility. In your permit, you and the DNR set mutually agreeable conditions for all the regulated processes within your facility that generate air pollution. Those conditions tell you how to comply with the different regulations.

Whether your business needs an operation permit could depend on where your business is located and the kinds and quantities of pollutants your business puts into the air. Moreover, certain processes or activities may be exempt from operation permit requirements. Some commonly regulated processes include: manufacturing lines, painting or coating operations (spray booth, dip coating, hand applied stains), boilers and furnaces, and wood processing. These are types of small businesses that may need operation permits:

  • Lithographic, screen and other commercial printers;
  • Solvent parts cleaners;
  • Industrial adhesive applications (such as kitchen counter top contact cement);
  • Wood furniture manufacturing; and
  • Metal finishing operations.

Types of operation permits

If your evaluations of the exemption options show you need an air operation permit, your next step is to identify what type of permit you'll need. You do this by calculating your facility's "maximum theoretical emissions" (MTE) and "potential to emit" (PTE). Links are provided above for resources to help you with these calculations. Once you know your emissions, based on which threshold you meet you can apply for the appropriate permit:

  • A "Title V Permit" (also called a "Part 70" Permit) is for businesses with a PTE over one of the threshold values:
    • any single criteria pollutant (PM, SO2, NOX, CO) or volatile organic compounds (VOC) above 100 tons per year;
    • a single federally regulated hazardous air pollutant above 10 tons per year; or
    • total of all federally regulated hazardous air pollutants above 25 tons per year.
  • A "Synthetic Minor" permit is for a business who has the potential to be a major source, but agrees by permit conditions to stay under major source emission limits. This could be done by requesting restrictions on hours of operation, type or amount of material processed, etc., to limit PTE.
    • One option is to take a synthetic minor limit under 99 tons per year. Anything between 99 tons per year and 80 tons per year is called SM80. You may see that code on different DNR documents.
    • You may also request synthetic minor limits at less than 80 tons per year (called "SM") for less stringent compliance and enforcement policies and lower fees.
    • Lower emissions caps in a synthetic minor permit may be needed in Nonattainment Areas, where the status of the area establishes a lower threshold for major sources.
  • If your business is not a major source, you will need a "Minor Source Operation Permit" (also called a "Non-Part 70 Permit"). There are multiple minor source operation permit options available. Review the Registration and General permit tabs on this page for more details.


There are no direct fees required to be issued an operation permit. However, everyone who is required to get an operation permit is required to pay annual fees. Review the pages Annual fee schedule for Title V Sources required to have an air permit and Annual air pollution fees for Non-Title V sources required to have an air permit for details.

How long until the permit is issued

The DNR processes source specific operation permit applications as quickly as possible given staffing conditions. The backlog of applications to review is nearly eliminated.

Before you receive a final operation permit, the department issues a draft permit for public review. This is also the company's opportunity to provide feedback on conditions in the permit, and whether they may be difficult to comply with. Also, you can begin to prepare to comply with the permit based on the draft by developing documentation that will be needed. This documentation may include:

  • Develop tracking sheets to be used on the unit or process line to collect compliance records.
  • Set up a compliance calendar, including reminders of regular inspections, reports, and other deadlines.
  • Set up a folder for all compliance records. Collect all "one time records", e.g., physical stack parameters, and verify compliance. Add a date and signature to records that you verify.
  • Prepare any plans required by the permit. These may include: Malfunction Prevention and Abatement Plan, Fugitive Dust Control Plan, and Standard Operating Procedures.

Final permit is issued

DO NOT just file the permit away as your ticket to operate and then forget about it in the file cabinet. The final permit outlines all the conditions you will be required to meet on a regular basis. As with your draft permit, pay attention to all the little details. Then make sure you have a system in place that will help you show the DNR, or anyone else who asks, that you are meeting each condition in your permit.

There is a five year life to Title V (major source) operation permits, but all other operation permits do not expire. It is a good idea to reread your permit at regular intervals to make sure you haven't missed anything. If you ever have any questions about how to comply with a certain requirement, contact your local DNR compliance contact.


Registration permits

A registration permit allows small emitters to quickly register themselves for a permit in return for keeping emissions low. The permits contain facility-wide emission caps as well as monitoring, recordkeeping and reporting requirements. Registration permits have a review time of no more than 15 days on all applications received by the DNR. To learn more about which type of Registration Permit may fit your operation, review the information on Registration Permit Options.

Compliance assistance reminders

Because the registration permit does not spell out all of the requirements that may apply to an individual facility, the Small Business Environmental Assistance Program worked together with the Air Program's Registration Permit Coordinator to send out quarterly reminders on different topics of concern. Review previous emails sent to ROP facilities on Registration Permits.


General permits available for certain industries

A general permit is intended for facilities that:

  • perform the same or similar operations;
  • emit similar air contaminants;
  • use the same or similar emission control technologies; and
  • are subject to the same limitations, standards and requirements.

General construction permits and operation permits have been developed for asphalt plants and rock crushing facilities. The general operation permits for the crushing facilities and hot mix asphalt plants do not expire. To learn more about which type of General Permit may fit your operation, review the information on the Air Program Permit Options page.

Additional resources