Definition(s)
Nonattainment area:
Nonattainment area means, for any air pollutant, an area that is shown by monitored data or that 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.
Source: Oil and Gas and Sulphur Operations in the Outer Continental Shelf, 30 CFR 250 (2013). Regulations