These are links about efforts to reduce tropospheric (ground-level) ozone, primarily through voluntary efforts by motorists, employers and industry.

Local and State

• Alabama
  • Birmingham
• California
  • Los Angeles area
  • Sacramento
  • San Francisco Bay area
  • San Joaquin Valley/Fresno area
• Georgia
  • Atlanta
• Illinois
  • Chicago
• Indiana
  • Chicago area
  • Indianapolis ("Knozone")
  • Louisville area
• Kansas
  • Kansas City
• Kentucky
  • Lexington/Bluegrass area
  • Louisville area
• Louisiana
  • Baton Rouge
• Maryland/DC
  • Baltimore/Washington area
• Michigan
  • Detroit area
  • Grand Rapids/Kalamazoo area
• Missouri
  • Kansas City
  • St. Louis
• New Jersey
• New York
  • New York City area
• North Carolina
  • Asheville area (“Land of Sky”)
  • Triad (Winston-Salem area)
• Ohio
  • Cincinnati
  • Cleveland area
  • Dayton area
• Oklahoma
  • Tulsa
• Pennsylvania
  • Philadelphia area
• Texas
  • Austin
  • Corpus Christi
  • Dallas/Fort Worth area
  • Houston/Galveston area: 
    • GHASP
    • Clean Air Action
• Wisconsin

Regional

• US EPA Region V (Indiana, Illinois, Michigan, Minnesota, Ohio, Wisconsin)