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Last Updated: Wednesday, June 25, 2008 11:48 AM

Areas Subject to Transportation Conformity Requirements in California

County/Planning Area/Air District	Regional Planning Agency Doing Conformity Analysis	Reason for Conformity Requirements (Federal Nonattainment Pollutant, or Attainment with "Section 175A" Maintenance SIP)
Butte	Butte County Association of Governments	Carbon Monoxide (Maintenance) Ozone
Nevada	No MPO — Rural Area Caltrans District 3 Nevada County Transportation Commission	Ozone (western portion of county only)
Yuba and Northern Sutter (outside Sacramento ozone area)	Sacramento Area Council of Governments	Ozone (Sutter Buttes over 2000 feet elevation only)
Sacramento Metropolitan ozone nonattainment area: Sacramento; Southern Sutter; Yolo; Solano (E. part); El Dorado, Placer (except Lake Tahoe basin)	Sacramento Area Council of Governments Metropolitan Transportation Commission (Solano Co. portion)	Carbon Monoxide (Sacramento urbanized area - Maintenance) Ozone Particulate Matter (PM10) (Sacramento County only)
El Dorado, Placer; Nevada Dept. of Environmental Protection (Lake Tahoe basin)	Tahoe Metropolitan Planning Organization	Carbon Monoxide (Maintenance)
Bay Area AQMD: Sonoma (S. part), Napa, Solano (W. part), Marin, Contra Costa, Alameda, San Francisco, San Mateo, Santa Clara	Metropolitan Transportation Commission	Carbon Monoxide (Maintenance) Ozone
Central Mountain Counties (Amador, Calaveras)	No MPO — Rural Area Caltrans District 10 Amador CTC Calaveras COG	Ozone
Southern Mountain Counties (Tuolumne, Mariposa)	No MPO — Rural Area Caltrans District 10	Ozone
San Joaquin	San Joaquin Council of Governments	Carbon Monoxide (Maintenance) Ozone Particulate Matter (PM10 and PM2.5)
Stanislaus	Stanislaus Council of Governments	Carbon Monoxide (Maintenance) Ozone Particulate Matter (PM10 and PM2.5)
Merced	Merced County Association of Governments	Ozone Particulate Matter (PM10 and PM2.5)
Madera	Madera County Transportation Commission	Ozone Particulate Matter (PM10 and PM2.5)
Fresno	Council of Fresno County Governments	Carbon Monoxide (Maintenance) Ozone Particulate Matter (PM10 and PM2.5)
Kings	Kings County Association of Governments	Ozone Particulate Matter (PM10 and PM2.5)
Tulare	Tulare County Association of Governments	Ozone Particulate Matter (PM10 and PM2.5)
Kern (San Joaquin Valley, Mojave Desert, and Indian Wells Valley areas)	Kern County Association of Governments	Carbon Monoxide (Maintenance) Ozone (except Indian Wells Valley) Particulate Matter (PM10) (San Joaquin Valley) Particulate Matter (PM10) (Indian Wells Valley - Maintenance) Particulate Matter (PM2.5) (San Joaquin Valley)
Ventura	Southern California Association of Governments	Ozone
Los Angeles (South Coast Air Basin)	Southern California Association of Governments	Carbon Monoxide (Maintenance) Ozone Particulate Matter (PM10 and PM2.5) Nitrogen Dioxide (Maintenance)
Los Angeles (Antelope Valley)	Southern California Association of Governments	Ozone
Orange	Southern California Association of Governments	Carbon Monoxide (Maintenance) Ozone Particulate Matter (PM10 and PM2.5) Nitrogen Dioxide (Maintenance)
San Bernardino (South Coast Air Basin)	Southern California Association of Governments	Carbon Monoxide (Maintenance) Ozone Particulate Matter (PM10 and PM2.5) Nitrogen Dioxide (Maintenance)
San Bernardino (Trona area)	Southern California Association of Governments	Particulate Matter (PM10)
San Bernardino (Mojave Desert area)	Southern California Association of Governments	Ozone (SE Desert Modified portion only) Particulate Matter (PM10)
Riverside (South Coast Air Basin)	Southern California Association of Governments	Carbon Monoxide (Maintnenance) Ozone Particulate Matter (PM10 and PM2.5) Nitrogen Dioxide (Maintenance)
Riverside (Coachella Valley)	Southern California Association of Governments	Ozone Particulate Matter (PM10)
Imperial	Southern California Association of Governments	Ozone Particulate Matter (PM10)
San Diego	San Diego Association of Governments	Carbon Monoxide (Maintenance) Ozone (nonattainment area excludes certain tribal lands)
Mono (Mono Lake, Mammoth Lakes planning areas)	No MPO — Rural Area Caltrans District 9 Mono County Local Transportation Commission	Particulate Matter (PM10) (specific areas only)
Inyo (Owens Valley, Searles Valley/Coso Jct. planning areas)	No MPO — Rural Area Caltrans District 9 Inyo County Local Transportation Commission	Particulate Matter (PM10) (specific areas only)

Notes:

The latest Air Pollution Control District and Air Quality Management District contact information can be obtained through from California Air Resources Board . Links above were current as of January, 2007.

For the latest contact information related to State and Regional transportation planning agencies, refer to the Caltrans Transportation Planning web site. MPO/RTPA web links were current as of December, 2006.

Maps and other materials related to nonattainment area designations in California can be found at the California Air Resources Board, and at EPA Region IX (both ).

This table is based only on Federal nonattainment and maintenance designations (see 40 CFR 81.305 and the U.S. EPA "Green Book") , which trigger Transportation Conformity requirements under 40 CFR 93 Subpart A . Many additional areas fail to attain one or more State air quality standards. Compliance with State standards is important for environmental analysis purposes but is not part of the Conformity process under the Federal Clean Air Act. More information regarding Transportation Conformity, including links to legislation, regulations, and guidance, can be found at the Federal Highway Administration and EPA web sites (both ).

Sources:

Federal Highway Administration , US Environmental Protection Agency, California Air Resources Board , Metropolitan Planning Organizations shown in table , Caltrans Division of Transportation Planning

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