ERC Calculations and Confirmation

(a) Calculation method for ERC generation. The quantity of ERCs generated is determined by subtracting the facility’s permit-limited potential emissions from the facility’s baseline actual emissions for ERC generation in accordance with the procedures in (1) and (2) below. (1) The baseline actual emissions for ERC generation shall be based on the definition of baseline actual emissions in OAC 252:100-8-31 with the changes in (A), (B), and (C) below: (A) Baseline actual emissions for ERC generation are only available for existing units that have been operating for at least 24 months. New units and existing units that have been operating less than 24 months are not eligible for the generation of ERCs. (B) For all units (whether they are classified as existing electric utility steam generating units or not), baseline actual emissions for ERC generation means the average rate, in TPY, at which the unit actually emitted the pollutant during any consecutive 24-month period selected by the owner or operator within the 5-year period immediately preceding the date that a complete permit application is received by the Director for the construction permit whose issuance will result in generation of ERCs. The Director shall allow the use of a different time period upon the determination that it is more representative of normal source operation. (i) The average rate shall include fugitive emissions to the extent quantifiable, and emissions associated with start-ups, shutdowns, and malfunctions. (ii) The average rate shall be adjusted downward to exclude any noncompliant emissions that occurred while the source was operating above an emission limitation that was legally enforceable during the consecutive 24-month period. (iii) For a regulated NSR pollutant, when a project involves multiple emissions units, only one consecutive 24-month period shall be used to determine the baseline actual emissions for ERC generation for all the emissions units affected by the project. A different consecutive 24-month period can be used for each regulated NSR pollutant. (iv) The average rate shall not be based on any consecutive 24-month period for which there is inadequate information for determining annual emissions, in TPY, and for adjusting this amount if required by (ii) above. (C) Units operating under a plantwide applicability limit (PAL), in accordance with OAC 252:100-8-30(c) and 8-38, are not eligible to generate ERCs. AQAC_2026_JUL_SC_7_8_10_RUL 18 June 15, 2026 (2) Calculation of the magnitude of ERCs created on issuance of the NSR permit used for ERC generation. (A) The quantity of ERCs shall be determined by subtracting the facility’s permit limited emissions for ERC generation from the facility’s baseline actual emissions for ERC generation. (B) Determination of surplus emission reductions. (i) In the permit record for the NSR permit establishing the ERCs, DEQ shall perform an assessment to determine whether the ERCs are surplus on generation. (ii) If some portion of the ERCs is determined not to be surplus, the quantity of ERCs shall be reduced accordingly and that determination shall be documented in the permit record. (b) Calculation method for ERC use. The quantity of ERCs that must be extinguished to offset project emission increases shall be determined in accordance with (1) and (2) below. (1) The applicant shall extinguish 1.1 ERC for each 1.0 ton of pre-offset project emission increase. (2) If the calculation in (1) above yields an outcome with fractional part, the number of ERCs that must be extinguished shall be rounded up to an integer value. (c) Determination that ERCs are surplus on generation and on use. DEQ shall confirm that ERCs are surplus on generation and on use in accordance with (1) and (2) below. (1) Applicant requirements. (A) The applicant for the permit that will result in generation of an ERC shall provide a justification demonstrating that the ERCs are surplus on generation. (B) The applicant for the permit that will result in extinguishment of an ERC shall provide a justification demonstrating that the ERCs are surplus on use. (2) An ERC is surplus if it satisfies both (A) and (B) below. (A) The emission reduction is not required by an otherwise applicable federal rule or state requirement enacted as part of the Oklahoma SIP. (B) The emission reduction is not required due to a state or federal enforcement action.