As discussed in our February 2018 eNews, the Minnesota Pollution Control Agency (MPCA) proposed several amendments to the air rules found in the Minnesota Administrative Rules regarding exempt sources and conditionally insignificant activities. The purpose of these amendments is to clarify permit requirements for small sources of air emissions and to update rules governing the treatment of small air pollution emitting activities (i.e., insignificant activities or conditionally insignificant activities). The MPCA provided a notice of intent to adopt the proposed amendments without a public hearing, and is currently in the process of reviewing public comments. A summary of the significant proposed changes is listed below:

  • Under Minn. R. 7007.1300, Subpart 1, emissions calculations must now be provided in a permit application if the insignificant emission units are described in either 7007.1300 subpart 3, Item F or subpart 4.
  • The MPCA transitioned various insignificant activity categories from Minn. R. 7007.1300, Subpart 3 (Insignificant Activities Required to be Listed) to Subpart 2 (Insignificant Activities Not Required to be Listed), such as handheld aerosol cans, hot metals extrusion, and blueprint copiers or photographic processes.
  • New emission units have been added to the list of insignificant activities that are not required to be listed in a permit application under Minn. R. 7007.1300, Subpart 2, such as plasma or laser cutting operations using a water table, electric steam sterilizers, and handheld equipment used for buffing, polishing, carving, cutting, drilling, machining, routing, sanding, sawing, surface grinding, or turning.
  • Proposed changes to Minn. R. Chapter 7008 would create four new categories (Auto-Body Refinishing, Coating Facility, Woodworking Facility, and Insignificant Facility) and modify two existing categories (Gasoline Service Stations, Concrete Manufacturing Facilities) of conditionally exempt sources where emissions primarily come from one type of activity.
  • The proposed changes also include modification to both 7008.4100 and 7008.4110 to align state rules with federal requirements for affected facilities to ensure the rules limiting air emissions are federally enforceable. The changes include adding new federally enforceable numeric emission limits for conditionally insignificant activities covered under 7008.4100
    • Under Minn. R. 7008.4100, owners or operators of coating and solvent cleaning operations that are conditionally insignificant activities must now limit VOC emissions to less than 10,000 pounds, or VOC containing material usage to be less than 1,000 gallons, for a calendar year.
    • Under Minn. R. 7008.4110, emissions of particulate matter from all finishing operations must be limited to less than 10,000 pounds for each calendar year.
    • Changes to Minn. R. 7008.4110 also introduce additional applicability rules, recordkeeping and monitoring requirements, and particulate matter emission calculation requirements.
  • Due to the proposed changes, permittees must include emission calculations for conditionally insignificant emission units as described in Minn. R. 7008.4100 and Minn. R. 7008.4110 in permit applications if the units:
    • Are part of a Part 70 permit or amendment to Part 70 permit;
    • Are subject to additional requirements under section 114(a)(3) or Section 112 of the Clean Air Act;
    • Are part of a Title I modification; or
    • When included in the facility total cause the facility to exceed the Part 70 permitting thresholds.

As noted above, this summary of proposed rule changes is not comprehensive of the proposed edits made by the MPCA. For more information on the proposed updates to these rules, or how the proposed changes could affect your facility, please contact Rydell Klosterman at (651) 275-9900 x9 or rklosterman@trinityconsultants.com.