EPA collects data from the states and regions on their air quality and state implementation plan (SIP) progress. This information is compiled in a database, and used to create reports, trend charts, and maps.

SIP Status for Nonattainment (Designated Area) Requirements

About these reports: If an area is designated as "nonattainment" (designated areas), states must develop a SIP that details the path to attain and maintain the National Ambient Air Quality Standards (NAAQS). Certain Northeast states, known as the Ozone Transport Region (OTR), must also submit a SIP for the pollutants that form ozone.

• State Designated Area Reports - For each NAAQS, find the status of a state's submissions and EPA actions on those submissions.
• National Designated Area Reports - For a single SIP required element for all applicable states, find the status of state submissions and EPA actions on those submissions.
• NAAQS Designated Area Reports - For each NAAQS, find the status of all state submissions and EPA actions on those submissions.

 See also: Where to find EPA actions on SIP submittals in the Federal Register.

Air Quality and Emissions Data 

• Status and trends of key air pollutants - EPA tracks the levels of criteria air pollutants and how much of each pollutant is emitted from various pollution sources.
• Design values - A design value is a statistic that describes the air quality status of a given location relative to the level of the NAAQS.
• AirNow - Current air quality index.
• AirData - Historical air quality data.
• National Emissions Inventory Interactive Report - Explains how air emissions data are generated and used as well as provides tools that explore emission trends and source contributions to air pollution.

Designations

• Ozone Designations: This web site provides information on the process EPA, the states, and the tribes follow to designate areas as "attainment" (meeting) or "nonattainment" (not meeting) the ground-level ozone standards.
• Green Book: listings of areas designated nonattainment for each NAAQS pollutant. It includes current designation and classification status, area maps, reports, and Federal Register notices.