On May 20, 2021, Ohio EPA began accepting public comments on draft changes to Ohio Administrative Code (OAC) Chapter 3745-110, “Nitrogen Oxides – Reasonably Available Control Technology.” The comment period ends on June 22, 2021.

These draft changes are being made to adopt mandatory Reasonably Available Control Technology (RACT) requirements for the Cincinnati and Cleveland 2015 ozone nonattainment areas. The Cincinnati ozone nonattainment area includes facilities located in Butler, Clermont, Hamilton, and Warren Counties. The Cleveland ozone nonattainment area includes facilities located in Cuyahoga, Geauga, Lake, Lorain, Medina, Portage, and Summit Counties.

The following is a summary of the most substantive changes:

  1. OAC rule 3745-110-02(A)(1)(c) is being added to regulate the following sources located in Butler, Clermont, Hamilton, or Warren Counties:
    • Existing very large boilers, large boilers, mid-size boilers, small boilers, stationary combustion turbines, stationary internal combustion engines, or reheat furnaces or
    • Existing sources located at a facility that has the potential to emit a total of more than one hundred tons per year of NOx emissions from all sources at that facility.
  2. OAC rule 3745-110-03(B) is being revised for mid-sized boilers as follows:
    • The NOx emission limit is being lowered from 0.10 lbs/MMBtu to 0.08 lbs/MMBtu for both tangential and wall gas-fired mid-sized boilers.
    • The NOx emission limit is being lowered from 0.12 lbs/MMBtu to 0.10 lbs/MMBtu for tangential, wall, and cyclone distillate oil-fired mid-sized boilers.
    • The NOx emission limit is being lowered from 0.23 lbs/MMBtu to 0.20 lbs/MMBtu for tangential, wall, and cyclone residual oil-fired mid-sized boilers.
  3. OAC rule 3745-110-03(C) is being revised for large boilers as follows:
    • The NOx emission limit is being lowered from 0.10 lbs/MMBtu to 0.08 lbs/MMBtu for both tangential and wall gas-fired large boilers.
    • The NOx emission limit is being lowered from 0.12 lbs/MMBtu to 0.10 lbs/MMBtu for tangential, wall, and cyclone distillate oil-fired large boilers.
    • The NOx emission limit is being lowered from 0.23 lbs/MMBtu to 0.20 lbs/MMBtu for tangential, wall, and cyclone residual oil-fired large boilers.
  4. OAC rule 3745-110-03(D) is being revised for very large boilers as follows:
    • The NOx emission limit is being lowered from 0.10 lbs/MMBtu to 0.08 lbs/MMBtu for both tangential and wall gas-fired very large boilers.
    • The NOx emission limit is being lowered from 0.12 lbs/MMBtu to 0.10 lbs/MMBtu for tangential, wall, and cyclone distillate oil-fired very large boilers.
    • The NOx emission limit is being lowered from 0.23 lbs/MMBtu to 0.20 lbs/MMBtu for tangential, wall, and cyclone residual oil-fired very large boilers.
  5. OAC rule 3745-110-03(E)(1) is being revised for simple cycle turbines as follows:
    • The NOx emission limit is being lowered from 42.0 ppmvd to 25.0 ppmvd, corrected to fifteen percent oxygen for simple cycle combustion turbines rated at greater than or equal to 3.5 MW firing only natural gas.
    • The NOx emission limit is being lowered from 96.0 ppmvd to 65.0 ppmvd corrected to fifteen percent oxygen for simple cycle combustion turbines rated at greater than or equal to 3.5 MW firing distillate oil or diesel fuel.
  6. OAC rule 3745-110-03(E)(2) is being revised for combined cycle turbines as follows:
    • The NOx emission limit is being lowered from 42.0 ppmvd to 25.0 ppmvd, corrected to fifteen percent oxygen for combined cycle combustion turbines rated at greater than or equal to 3.5 MW firing only natural gas.
    • The NOx emission limit is being lowered from 96.0 ppmvd to 65.0 ppmvd corrected to fifteen percent oxygen for combined cycle combustion turbines rated at greater than or equal to 3.5 MW firing distillate oil or diesel fuel.
  7. Under OAC rule 3745-110-03(F), NOx emission limits for stationary combustion engines are being expanded from engines greater than 2,000 hp to engines greater than 500 hp.
  8. The exemption OAC rule 3745-110-03(K)(18) is being removed that previously exempted boilers, stationary internal combustion engines, or stationary combustion turbines subject to 40 CFR 97 Subparts AAAAA, BBBBB, or EEEEE from the requirements of paragraphs (A) through (G).
  9. The exemption OAC rule 3745-110-03(K)(19) is being removed that previously exempted any boiler subject to paragraph (C)(1) of OAC rule 3745-14-01 (NOx budget rule) from the requirements of paragraphs (A) through (G).
  10. OAC rule 3745-110-04(A)(3) is being added to require sources located in Butler, Clermont, Cuyahoga, Geauga, Hamilton, Lake, Lorain, Medina, Portage, Summit, or Warren counties for which the director has established a site-specific definition of RACT in accordance with paragraph (J) of OAC rule 3745-110-03 to submit an updated RACT study to Ohio EPA within one year of the effective date of this rule.
  11. OAC rule 3745-110-04(B) is being revised to allow facilities two years to comply if combustion modifications are required to demonstrate compliance with the applicable emission limitations or three years to comply if add-on controls are required to demonstrate compliance with the applicable emission limitations.

More information on this public notice can be obtained at https://www.epa.ohio.gov/dapc/DAPCrules#188902674-interested-party-review.

Contact Ron Hansen at rhansen@gtenvironmental.com or (614) 794-3570 Ext. 121 for assistance with complying with these rule changes.