Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock (LockA locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Emergency

This is not the current EPA website. To navigate to the current EPA website, please go to www.epa.gov. This website is historical material reflecting the EPA website as it existed on January 19, 2025. This website is no longer updated and links to external websites and some internal pages may not work. More information »

    • Environmental Topics
    • Air
    • Bed Bugs
    • Cancer
    • Chemicals, Toxics, and Pesticide
    • Climate Change
    • Emergency Response
    • Environmental Information by Location
    • Environmental Justice
    • Greener Living
    • Health
    • Land, Waste, and Cleanup
    • Lead
    • Mold
    • Radon
    • Research
    • Science Topics
    • Water Topics
    • A-Z Topic Index
    • Laws & Regulations
    • By Business Sector
    • By Topic
    • Compliance
    • Enforcement
    • Laws and Executive Orders
    • Regulations
    • Report a Violation
    • Environmental Violations
    • Fraud, Waste or Abuse
    • About EPA
    • Our Mission and What We Do
    • Headquarters Offices
    • Regional Offices
    • Labs and Research Centers
    • Planning, Budget, and Results
    • Organization Chart
    • EPA History
    • Staff Directory

Breadcrumb

  1. Home
  2. Air Quality System (AQS)
  3. Related Resources
  4. Quality Assurance and Audits Memos

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.


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

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)

Air Quality System (AQS)

  • AQS User Support
    • New User Registration
    • Training
    • Events Calendar
    • Java Memo
  • All Manuals and Guides
    • User Guide
      • AQS at a Glance
      • ENSC at a Glance
      • Logging On
      • Site ID Format
      • Batch Submission - Overview
      • Batch Submission - Using the ENSC
      • Batch Submission - Loading Using AQS
      • Batch Submission - Type of Data
      • Correct - Overview
      • Correct - Raw Data
      • Correct - 1-PT QC
      • Maintain - Overview
      • Maintain - Site
      • Maintain - Monitor
      • Maintain - Adding Events
      • Maintain - QA
      • Setting Up Samplers
      • Data Reports
      • CA Dump Bucket
      • Logging Off and Additional Info
    • Code Lists
    • Data Dictionary
    • Data Coding Manual
    • AQS Primer
    • Frequent Questions
  • Related Resources
    • Monitoring and Policy Memos
    • AQS Pollutant Memos
    • Quality Assurance and Audits Memos
  • Archive Data
  • Obtaining AQS Data
    • API
    • About AQS Datamart
    • Pre-Generated Data
AQS Contact Us
AQS Contact Us to ask a question, provide feedback, or report a problem.
Last updated on April 29, 2024
  • Assistance
  • Ayuda
  • Arabic
  • Chinese (simplified)
  • Chinese (traditional)
  • Aide
  • Asistans
  • Korean
  • Assistência
  • Russian
  • Tulong
  • Vietnamese
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshot
  • Grants
  • No FEAR Act Data
  • Plain Writing
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data
  • Inspector General
  • Jobs
  • Newsroom
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions

Follow.