This database maintains compliance information on facilities regulated under the Clean Air Act, as well as Titles I, III, IV, and V of the Amendments. The compliance information within the database pertain to major sources of hazardous and criteria air pollutants. A major source is defined as any stationary source or group of stationary sources located within a contiguous area and under common control that emits or has the potential to emit air pollutants above thresholds specified in the Clean Air Act and its Amendments. The submission process includes checks during data entry to minimize errors.
Regions provide quality assurance for the data provided by the States within that Region.
State compliance data coverage within AIRS-AFS is uneven as a result of varying State definitions and requirements, as well as differences in the structure and operation of State data collection, translation, and reporting activities. Analyses using only the nationally required data are more meaningful in situations where consistency is required. AIRS-AFS data are appropriate for both spatial and temporal analyses. Spatial analyses are possible through utilization of address and ZIP code information which is consistently available. Updates to AIRS-AFS are made quarterly, but some States may be more diligent than others with regard to the timeliness of their updates, which may result in temporal inconsistencies.