On November 5, 2018 the Minnesota Pollution Control Agency (MPCA) officially adopted rule updates to the exempt source/conditionally insignificant activities chapters in the Minnesota Administrative Rules. The rules were published in the January 7, 2019 State Register, and will become effective on January 14, 2019.

These rules have been previously discussed in our February and April 2018 eNews articles. Since the last version of the proposed rules, outlined in our April eNews article, the MPCA has made additional updates to the rules based on the comments received during the public comment period. A brief overview of how the adopted rules have changed since our previous article is detailed below.

Insignificant Activities Changes

The adopted rules added new definitions and made changes to which insignificant activities are and are not required to be listed on permit applications. Since the previous proposed rules publication, the following changes were made:

  • Updated typos and clarifications, such as replacing "or" with "and", i.e., acids that volatize HAPs or VOCs.
  • Added new definitions for Hood and Total enclosure.
    • The definitions used in 7005.0100 are now based off of definitions from part 7011.0060, Standards for Stationary Sources.
  • Non-handheld equipment used for buffing, polishing, carving, cutting, drilling, machining, routing, sanding, sawing, surface grinding, or turning can be considered insignificant activities not required to be listed, as long as the item is used infrequently and not associated with the primary production process
  • Included torch-cutting as an insignificant activity requiring to be listed.
  • Changed the word "finishing operations" to "mechanical finishing operations".
    • Change was to reinforce that these rules were made with physical operations in mind, not chemical.

Conditionally Insignificant Source Changes

The new rules added four new categories of Conditionally Insignificant Sources: Auto-Body Refinishing Facilities, Coating Facilities, Woodworking Facilities, and Insignificant Facilities. These facilities are not required to obtain an air permit. Since the previous proposed rules publication, the following changes were made:

  • Included "finishes" in the definition of woodworking facility
    • This was updated to clear up confusion about the original definition. Now the definition applies to both finishing new products and refinishing existing products.
  • Updated language for the auto-body refinishing facilities and coating facilities language to include a second option for eligibility, emissions calculations.
    • Previously the source was only eligible if they purchased or used less than 2,000 gallons of VOC containing coating and cleaning materials combined.
    • Sources can now calculate emission totals for eligibility. If they emit less than 20,000 lbs of VOC and less than 12,000 lbs of HAPs per calendar year, the source is eligible.
      • Calculations must be completed using the specified process in the Part 7008.2300 and 7008.2400.
      • Additional records must be kept on site as described in Part 7008.2300 and 7008.2400.
  • Painters at an auto-body refinishing source must be trained within 180 days of hiring and every five years after initial training
  • Clarified the size of aerosol or pump spray containers (< 16 ounces) that were excluded from control requirements
  • Woodworking facilities now have a requirement to have less than 25 MMBtu/hr total heat input capacity for all ovens used for curing
  • Additional eligibility criteria of less than 40,000 lbs per calendar year of particulate matter emissions or limiting the aggregate airflow rate out of a control device at the facility to either 177,000 cfm through a total enclosure or 80,000 cfm through a certified hood.
  • Additional control requirements for woodworking facilities based on aggregate airflow rates

Conditionally Insignificant Activities Changes

The new rules added additional requirements to make the conditionally insignificant activities federally enforceable. Since the previous proposed rules publication, the following changes were made:

  • Changed the word finishing to mechanical finishing.
    • Wording change was to focus on physical operations, not chemical.
  • Additional small wording changes, i.e., adding "must" to requirements.
  • Added additional requirements for mechanical finishing operations vented to control equipment.
  • Updated part 7007.1250 to allow an insignificant permit modification to be made if the modification only has conditionally insignificant activities or insignificant activities.
    • Previously, modifications that only had conditionally insignificant activities were not allowed under insignificant permit modifications under the proposed 2016 Omnibus Air Rule.

As noted above, this summary of changes in the adopted rules is not comprehensive of the adopted rules. For more information on the adopted rules, or how these changes could affect your facility, please contact Rydell Klosterman at (651) 275-9900 ext. 9 or rklosterman@trinityconsultants.com.