Okla. Admin. Code § 252:100-11-2
The following words and terms, when used in this Subchapter, shall have the following meaning, unless the context clearly indicates otherwise.
"Actual emissions" for purposes of this Subchapter, means the lowest emission rate in tons per year at which the facility actually emitted a specific pollutant during the three-year period immediately preceding the date of the alternative emissions reduction plan. The DEQ may allow the use of a different time period upon a determination that it is more representative of normal operations.
"Affected emission point" for purposes of this Subchapter, means an emission point that will undergo an emissions reduction or emissions increase in an alternative emissions reduction plan.
"Affected pollutant" for purposes of this Subchapter, means any regulated air pollutant that is reduced or increased as a result of the implementation of an alternative emissions reduction plan.
"Net emissions reduction" means the amount by which emissions from a facility will be reduced in an alternative emissions reduction plan. Net emissions reduction shall be calculated by subtracting the emissions of a specific pollutant allowed under an alternative emissions reduction plan from the facility's actual emissions, potential emissions, the emissions allowed under the operating permit, or the emissions allowed by rule, whichever is least.
"Potential emissions" for purposes of this Subchapter, means the level of emissions a source emits when operating at maximum capacity considering enforceable reductions from air pollution controls and other enforceable restrictions such as hours of operation, types of raw material or fuel, etc.
Okla. Admin. Code § 252:100-11-2