#### § 550.302 Definitions concerning air quality.

For purposes of §§ 550.303 and 550.304 of this part:

*Attainment area* means, for any criteria air pollutant, an area which is shown by monitored data or which is calculated by air quality modeling (or other methods determined by the Administrator of EPA to be reliable) not to exceed any primary or secondary ambient air quality standards established by EPA.

*Best available control technology (BACT)* means an emission limitation based on the maximum degree of reduction for each criteria air pollutant and VOC subject to regulation, taking into account energy, environmental and economic impacts, and other costs. The BACT shall be verified on a case-by-case basis by the Regional Supervisor and may include reductions achieved through the application of processes, systems, and techniques for the control of each criteria air pollutant and VOC.

*Criteria air pollutant* means any air pollutant for which the EPA has established a primary or secondary national ambient air quality standard pursuant to section 109 of the Clean Air Act.

*Emission exemption threshold* (EET) means the rate of projected emissions, calculated for a criteria air pollutant or VOC or TSP, above which a facility would be subject to the requirements of § 550.303(e) through (i) or § 550.304(b) through (e).

*Emission offsets* mean emission reductions obtained from facilities, either onshore or offshore, other than the facility or facilities covered by the proposed Exploration Plan (EP), Development and Production Plan (DPP), or Development Operations Coordination Document (DOCD).

*Existing facility,* as used in § 550.303, means an OCS facility described in an Exploration Plan, a Development and Production Plan, or a Development Operations Coordination Document approved before June 2, 1980.

*Facility* means any installation or device permanently or temporarily attached to the seabed which is used for exploration, development, and production activities for oil, gas, or sulphur and which emits or has the potential to emit any air pollutant from one or more sources. All equipment directly associated with the installation or device shall be considered part of a single facility if the equipment is dependent on, or affects the processes of, the installation or device. During production, multiple installations or devices will be considered to be a single facility if the installations or devices are directly related to the production of oil, gas, or sulphur at a single site. Any vessel used to transfer production from an offshore facility shall be considered part of the facility while physically attached to it.

*National Ambient Air Quality Standard* (NAAQS) means a national air quality standard for any given criteria air pollutant, established pursuant to section 109 of the Clean Air Act.

*Nonattainment area* means, for any criteria air pollutant, an area which is shown by monitored data or which is calculated by air quality modeling (or other methods determined by the Administrator of EPA to be reliable) to exceed any primary or secondary ambient air quality standard established by EPA.

*Projected emissions* mean emissions, either controlled or uncontrolled, from a source(s).

*Source* means an emission point. Several sources may be included within a single facility.

*Temporary facility* means activities associated with the construction of platforms offshore or with facilities related to exploration for or development of offshore oil and gas resources which are conducted in one location for less than 3 years.

*Volatile organic compound (VOC)* means any organic compound that is emitted to the atmosphere as a vapor. Unreactive compounds are excluded from the preceding sentence of this definition.

[76 FR 64623, Oct. 18, 2011, as amended at 85 FR 34936, June 5, 2020]