Amendments to air quality rules - Exempt source/conditionally insignificant activities

The Minnesota Pollution Control Agency (MPCA) has adopted amendments to rules governing air quality, Minnesota Rules chapters 7005, 7007, 7008, 7011, and 7019. The new rules clarify permit requirements for small sources of air emissions, and update rules governing the treatment of small air pollution emitting facilities and activities. The rules also include four new categories of conditionally exempt sources: auto-body refinishing facilities, coating facilities, woodworking facilities, and "insignificant facilities." Rule-related documents are provided below.

The new rules are effective January 14, 2019.

Small sources of air emissions can access notification forms and information specific to the new conditionally exempt sources: Conditionally Exempt Facilities and Insignificant Facility. If you are a small business (less than 100 employees) and have questions, you can contact the Small Business Environmental Assistance Program, 800-657-3938 or 651-282-6143,

Rule implementation

PDF icon Exempt Source/Conditionally Insignificant Activities Rulemaking and Implementation (aq-rule4-08m)

This document provides information on how the MPCA will implement the rule changes.

File Insignificant Facility PTE calculator (p-sbap5-35)

Use this spreadsheet to calculate emissions to determine eligibility as an "insignificant facility" under Minn. R. 7008.2600.

The purpose of the exempt source/conditionally insignificant activities rulemaking is to clarify permit requirements for small sources of air emissions and update rules governing the treatment of small air pollution emitting activities. These activities are described as “insignificant activities” and “conditionally insignificant activities” in the rules. The MPCA is also creating new categories of conditionally exempt sources, such as auto-body refinishing facilities and woodworking facilities. Such facilities that meet applicable technical standards would be exempt from obtaining an air emissions permit.

This rulemaking is needed to address several issues with the requirements for conditionally exempt stationary sources and conditionally insignificant activities, and to meet federal requirements for affected sources. Historically, the MPCA created an air emission permit hierarchy to incentivize the small source facilities, such as auto body refinishing facilities, to reduce their air emissions through more streamlined compliance requirements for low air emissions. The rule amendments will continue to streamline the administrative requirements for the lower emitting small source facilities while complying with applicable state and federal requirements. The main benefit of the rule amendments will be administrative, but they will also ensure that the rules limiting air emissions are federally enforceable.

Notice of Request for Comments

January 9, 2017

Stakeholder engagement

Stakeholder meeting on proposed concepts for amending the rules (January 19, 2017)

Notice of Intent to Adopt Rules

April 23, 2018

Stakeholder engagement Public information meeting on proposed rule amendments (May 10, 2018)
Notice of Adopted Rules January 7, 2019



For questions about rule content or technical aspects of the rule:

Hassan Bouchareb

For questions about the rule process or schedule:

Mary H. Lynn