In a unanimous vote on Thursday, November 15, 2018, the Oregon Environmental Quality Commission (EQC) approved the Cleaner Air Oregon (CAO) rules codified in Oregon Administrative Rules (OAR) 340-245. The Oregon toxics rulemaking process and program overhaul began in April 2016, with the first draft rule published in October 2017. The Oregon Department of Environmental Quality (DEQ) published a second draft of the rule in June 2018 taking into account Senate Bill 1541 (March 2018). On October 31, 2018, DEQ submitted a Staff Report to EQC including the final rule for approval, responses to public comments from both draft rules, and additional relevant information.

The basic attributes of the final rule requires existing air quality permit holders (or those who have submitted a complete application to DEQ by November 16, 2018) to complete the following actions. Actions #3 and beyond detailed below are only required after Action #2 has occurred.

  1. Triennially submit a toxic emission inventory (first submittal in 2020 for 2019 reporting year) - required for all air permit holders and those requested by DEQ.
  2. Complete a facility wide Risk Assessment (or demonstrate exemption) when:
    1. Notified in writing by DEQ, or
    2. Facility is modified under division 224, New Source Review (PSD modification, with minor exceptions).
  3. Complete required actions based on the facilities calculated Risk (identified as Risk Action Levels (RALs) in rule) which may include:
    1. Obtaining a toxic permit,
    2. Community engagement meeting,
    3. Demonstrate toxic best available control technology (tBACT), and/or
    4. Risk Reduction Plan.
  4. Submit an application to modify the Toxic Permit Addendum or operating permit:
    1. Prior to constructing a new or modified significant toxic emission units (TEUs), or
    2. If a new or modified TEU will invalidate facilities exemption from the CAO program.
  5. Submit an annual report indicating compliance with Toxic Permit Addendum or operating permit and review of TBACT and zoning changes.

The Risk Assessment has 4 levels of evaluation with an increasing level of complexity. This has not changed since the previous rule iteration. As a reminder, the assessment levels are as follows:

  • Level 1 - ∑ (Published Dispersion Factor x Emission Rate)/Risk Based Concentrations
  • The summation is for each pollutant and each stack
  • Level 2 - ∑ AERSCREEN (or comparable model approved by DEQ) Model Results/Risk Based Concentrations
  • The summation is for each pollutant and each stack
  • Level 3 - ∑ AERMOD (or comparable model approved by DEQ) Model Results/Risk Based Concentrations
  • The summation is for each pollutant; AERMOD results are for combined stack concentration
  • Level 4 - Air Dispersion Modeling + Health Risk Assessment (evaluation of bioaccumulation and toxicity)

Some notable changes from the June 2018 draft include:

  • Risk Assessment Timing - DEQ updated timelines for submittals, and added approvals, as detailed below:
    • Emission Inventory due 90 days after DEQ Notice date;
    • Modeling Protocol is due 30 days after DEQs approval of Emission Inventory (required for all levels of review);
    • Level 1 or Level 2 Risk Assessment is due 60 days after receiving DEQ approval of Modeling Protocol;
    • Level 3 or Level 4 Work Plan is due 60 days after receiving DEQ approval of the Emissions Inventory;
    • Level 3 Risk Assessment is due 120 days after receiving DEQ approval of the Level 3 Work Plan; and
    • Level 4 Risk Assessment is due 150 days after receiving DEQ approval of the Level 4 Work Plan.
  • Note a facility is not required to submit all levels of Risk Assessment, only the one selected by the facility.
    • Upon completion of the required Risk Assessment, assuming a Risk Reduction Plan and/or Monitoring Plan is not required, an Application for the Toxic Air Contaminant Permit Addendum is due 30 days after DEQs approval of the Level 1-4 Risk Assessment
  • Source Permit Level - DEQ updated the RAL requiring existing facilities to obtain a Toxic Permit Addendum from a calculated cancer risk of 0.5 in a million to five (5) in a million.
  • Exempt TEU - DEQ had previously proposed that categorically insignificant activities listed in OAR 340-200-0020(23) would also be exempt under CAO regulations with the exception of maintenance shops (OAR 340-200-0020 (23)(m)) and de minimis levels of chemicals within a mixture (OAR 340-200-0020 (23)(a)). In the final rule, maintenance shops are exempt; however, DEQ may request information specific to a maintenance shop to assess risk (OAR 340-245-0060(3)(c)). Exempt TEU are not required to be included in the Risk Assessment (this is consistent with previous draft).
  • Aggregate TEU - this is a new term in the current rule. A facility may designate any number of emission units/activities with a total cumulative risk less than the Aggregate TEU level to be an aggregated TEU.
    • Aggregated TEUs are not required to be included in the Risk Assessment.
    • The same emission units/activities must be designated for all evaluations of risk (cancer, chronic noncancer, and acute noncancer).
    • A facility must request approval to change sources designated as aggregated TEUs, modify existing sources, or add new sources assuming all sources remain below the threshold.
  • New or Modified Equipment Notification - DEQ made a few changes related to facility equipment updates.
    • A facility is required to submit a construction approval application under the CAO rule for significant TEUs, but only after a Toxic Permit Addendum has been issued for the facility.
    • If a facility chooses to add additional TEUs during the Risk Assessment process, an updated Risk Assessment will be required.
    • The previous rule had a "Risk Assessment Notification" which required notification for any facility changes (exempt or significant). This term has been removed from the rule.
  • Fugitive Sources - DEQ has added Table 5C and 5D for the Level 1 Risk Assessment to include fugitive sources. Facilities that had fugitive sources previously were not allowed to use the Level 1 Risk Assessment.

Trinity would highly recommend facilities begin completing a Risk Assessment to allow sufficient time to complete the desired level of review resulting in a desirable action level. To review historical Oregon related articles Trinity has published please use this link.

For questions on the final CAO rules, please contact our Seattle Office at (253) 867-5600.