The data summarized in this Web site come directly from the Air Quality System (AQS) Data Mart. The AQS Data Mart contains ambient air pollution data collected by EPA, state, local, and tribal air pollution control agencies from thousands of monitoring stations. The Office of Air Quality Planning and Standards (OAQPS) and other AQS users rely upon the data to assess air quality, assist in Attainment/Non-Attainment designations, evaluate State Implementation Plans for Non-Attainment Areas, perform modeling for permit review analysis, and other air quality management functions.