We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

AQS Related Resources

AIRData access to annual summaries of air pollution data.

AIRNOW is the EPA site with current Air Quality Index (AQI) levels indicating how clean the air is and whether it will affect your health.

CDX (Central Data Exchange) is the EPA's electronic reporting site.

State and Local Air/Environmental Agencies links to regional, state and local agency pages.

AMTIC (Ambient Monitoring Technology Information Center) contains information and files on ambient air quality monitoring programs, details on monitoring methods, relevant documents and articles, information on air quality trends and nonattainment areas, and federal regulations related to ambient air quality monitoring.

CHIEF (Clearinghouse for Inventories and Emissions Factors) is the EPA site that includes the NEI (National Emissions Inventory) database. The NEI replaces AFS as the EPA's repository of air emissions information for facilities, area, and mobile sources.

AFS (AIRS Facility Subsystem) formerly a subsystem of the Aerometric Information Retrieval System (AIRS) now operated and maintained by the EPA's Office of Enforcement and Compliance Assurance (OECA).


The following links are pointers to other hosts and locations on the Internet. This information is provided as a service. However, the U.S. Environmental Protection Agency does not endorse, approve or otherwise support the non-EPA sites. The following links exit the site Exit

Exchange Network for AQS data exchange (Node to node)

ECOS (Environmental Council of the States)

NACAA (National Association of Clean Air Agencies, formerly STAPPA/ALAPCO, State and Territorial Air Pollution Program Administrators / Association of Local Air Pollution Control Officials)

IMPROVE (National Park Service visibility data, operated by Colorado State University)