Sulfur Dioxide (1971) Maintenance Area (Redesignated from Nonattainment) Area/State/County Report

Data is current as of November 30, 2025

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Ajo (Pima County), AZ (Primary - Maintenance)

ARIZONA (Region IX)

Pima County (P)

Allegheny County Air Basin: Hazelwood monitor, PA (Primary - Maintenance)

PENNSYLVANIA (Region III)

Allegheny County (P)

Benton County; (part) TVA Johnsonville, TN (Primary, Secondary - Maintenance)

TENNESSEE (Region IV)

Benton County (P)

TVA Johnsonville

Boyd County (part), KY (Primary - Maintenance)

KENTUCKY (Region IV)

Boyd County (P)

Brown County: Green Bay, WI (Primary - Maintenance)

WISCONSIN (Region V)

Brown County (P)

Central Steptoe Valley, NV (Primary - Maintenance)

NEVADA (Region IX)

White Pine County (P)

Colbert County (part); TVA Colbert Plant, AL (Secondary - Maintenance)

ALABAMA (Region IV)

Colbert County (P)

Coshocton County; Franklin Township, OH (Primary - Maintenance)

OHIO (Region V)

Coshocton County (P)

Franklin Township

Cuyahoga County, OH (Primary - Maintenance)

OHIO (Region V)

Cuyahoga County (P)

Dane County: Madison sub-city area, WI (Primary - Maintenance)

WISCONSIN (Region V)

Dane County (P)

Douglas (Cochise County), AZ (Primary - Maintenance)

ARIZONA (Region IX)

Cochise County (P)

East Helena Area, MT (Primary, Secondary - Maintenance)

MONTANA (Region VIII)

Lewis and Clark County (P)

Gallia County; Addison Township, OH (Secondary - Maintenance)

OHIO (Region V)

Gallia County (P)

Addison Township

Grant County, NM (Primary - Maintenance)

NEW MEXICO (Region VI)

Grant County (P)

AQCR 012: Portions of Grant County

Hancock County (part): Weirton, WV (Primary, Secondary - Maintenance)

WEST VIRGINIA (Region III)

Hancock County (P)

The city of Weirton, including Butler and Clay Magisterial Districts.

Humphreys County; (part) TVA Johnsonville, TN (Primary, Secondary - Maintenance)

TENNESSEE (Region IV)

Humphreys County (P)

TVA Johnsonville

Jefferson County; (part) Steubenville & Mingo Junction, OH (Primary - Maintenance)

OHIO (Region V)

Jefferson County (P)

La Porte County, IN (Primary - Maintenance)

INDIANA (Region V)

LaPorte County (P)

Lake County, IN (Primary - Maintenance)

INDIANA (Region V)

Lake County (P)

Lake County; (part) Eastlake, Timberlake, Lakeline, Willoughby, Mentor, OH (Primary - Maintenance)

OHIO (Region V)

Lake County (P)

Eastlake, Timberlake, Lakeline, Willoughby, and Mentor

Lauderdale County (part); TVA Colbert Plant, AL (Secondary - Maintenance)

ALABAMA (Region IV)

Lauderdale County (P)

Lorain County, OH (Primary - Maintenance)

OHIO (Region V)

Lorain County (P)

Lucas County, OH (Primary - Maintenance)

OHIO (Region V)

Lucas County (P)

Marathon County: Rothschild Sub-city area, Rib Mountain, Weston, WI (Primary, Secondary - Maintenance)

WISCONSIN (Region V)

Marathon County (P)

Marion County: Lawrence, Washington, and Warrant Townships, IN (Primary - Maintenance)

INDIANA (Region V)

Marion County (P)

The area included within Lawrence, Washington, and Warren Townships.

Miami (Gila County), AZ (Primary - Maintenance)

ARIZONA (Region IX)

Gila County (P)

Millinocket AQCR 109, ME (Primary - Maintenance)

MAINE (Region I)

Penobscot County (P)

Milwaukee, WI (Primary - Maintenance)

WISCONSIN (Region V)

Milwaukee County (P)

Minneapolis-St. Paul, MN (Primary - Maintenance)

MINNESOTA (Region V)

Anoka County

Carver County

Dakota County

Hennepin County

Ramsey County

Scott County

Washington County

Morenci (Greenlee County), AZ (Primary - Maintenance)

ARIZONA (Region IX)

Greenlee County (P)

Morgan County: Center Township, OH (Secondary - Maintenance)

OHIO (Region V)

Morgan County (P)

Muhlenberg County, KY (Secondary - Maintenance)

KENTUCKY (Region IV)

Muhlenberg County

Muscatine County, IA (Primary - Maintenance)

IOWA (Region VII)

Muscatine County (P)

New Manchester-Grant magisterial district in Hancock County, WV (Primary - Maintenance)

WEST VIRGINIA (Region III)

Hancock County (P)

New Manchester-Grant magisterial district in Hancock County.

Olmsted County; City of Rochester, MN (Primary - Maintenance)

MINNESOTA (Region V)

Olmsted County (P)

City of Rochester

Oneida County: Rhinelander Sub-city area, WI (Primary, Secondary - Maintenance)

WISCONSIN (Region V)

Oneida County (P)

Peoria County: Hollis twp, IL (Primary, Secondary - Maintenance)

ILLINOIS (Region V)

Peoria County (P)

Peoria, IL (Primary - Maintenance)

ILLINOIS (Region V)

Peoria County (P)

Polk County, TN (Primary, Secondary - Maintenance)

TENNESSEE (Region IV)

Polk County

San Manual (Pinal County), AZ (Primary - Maintenance)

ARIZONA (Region IX)

Pinal County (P)

Tazewell County: Groveland twp, IL (Primary - Maintenance)

ILLINOIS (Region V)

Tazewell County (P)

Vigo County, IN (Primary - Maintenance)

INDIANA (Region V)

Vigo County

Warren County, NJ (Primary, Secondary - Maintenance)

NEW JERSEY (Region II)

Warren County (P)

Northeast Pennsylvania-Upper Delaware Valley Interstate AQCR

Warren County: Conewago Twp, PA (Primary - Maintenance)

PENNSYLVANIA (Region III)

Warren County (P)

Conewango Twp.

Warren County: Warren Boro, Pleasant Twp, Glade Twp, PA (Primary, Secondary - Maintenance)

PENNSYLVANIA (Region III)

Warren County (P)

Warren Boro, Pleasant Twp, Glade Twp

Washington County: Waterford Township, OH (Secondary - Maintenance)

OHIO (Region V)

Washington County (P)

Wayne County: Boston, Center, Franklin, Wayne & Webster Townships, IN (Primary - Maintenance)

INDIANA (Region V)

Wayne County (P)

Boston, Center, Franklin, Wayne, and Webster Twps

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