Utah.

Utah—1971 Sulfur Dioxide NAAQS [Primary and Secondary] Designated area Does not meet primary standards Does not meet secondary standards Cannot be classified Better than national standards Salt Lake County 1 X 1 X Portions of Tooele County 1 X 1 X Rest of State X 1 EPA designation replaces State designation. Utah—2010 Sulfur Dioxide NAAQS [Primary] Designated area 1 Designation Date 2 Type Statewide: Beaver County Attainment/Unclassifiable. Box Elder County Attainment/Unclassifiable. Cache County Attainment/Unclassifiable. Carbon County Attainment/Unclassifiable. Daggett County Attainment/Unclassifiable. Davis County Attainment/Unclassifiable. Duchesne County Attainment/Unclassifiable. Emery County Attainment/Unclassifiable. Garfield County Attainment/Unclassifiable. Grand County Attainment/Unclassifiable. Iron County Attainment/Unclassifiable. Juab County Attainment/Unclassifiable. Kane County Attainment/Unclassifiable. Millard County Attainment/Unclassifiable. Morgan County Attainment/Unclassifiable. Piute County Attainment/Unclassifiable. Rich County Attainment/Unclassifiable. Salt Lake County Attainment/Unclassifiable. San Juan County Attainment/Unclassifiable. Sanpete County Attainment/Unclassifiable. Sevier County Attainment/Unclassifiable. Summit County Attainment/Unclassifiable. Tooele County Attainment/Unclassifiable. Uintah County Attainment/Unclassifiable. Utah County Attainment/Unclassifiable. Wasatch County Attainment/Unclassifiable. Washington County Attainment/Unclassifiable. Wayne County Attainment/Unclassifiable. Weber County Attainment/Unclassifiable. 1 Includes any Indian country in each county or area, unless otherwise specified. EPA is not determining the boundaries of any area of Indian country in this table, including any area of Indian country located in the larger designation area. The inclusion of any Indian country in the designation area is not a determination that the state has regulatory authority under the Clean Air Act for such Indian country. The lands of the Navajo Nation, including those lands located geographically within Utah, are excluded, as they are separately designated under Section 81.303. 2 This date is April 9, 2018, unless otherwise noted. Utah—Carbon Monoxide Designated Area Designation Classification Date 1 Type Date 1 Type Ogden Area Weber County (part) city of Ogden 5/8/2001 Attainment Provo Area Utah County (part) city of Provo 1/3/2006 Attainment Salt Lake City Area 3/22/1999 Attainment Salt Lake County (part), Salt Lake City Rest of State Unclassifiable/Attainment Beaver County Box Elder County Cache County Carbon County Daggett County Davis County Duchesne County Emery County Garfield County Grand County Iron County Juab County Kane County Millard County Morgan County Piute County Rich County Salt Lake County (part) Remainder of Salt Lake County San Juan County Sanpete County Sevier County Summit County Tooele County Uintah County Utah County (part) Remainder of Utah county Wasatch County Washington County Wayne County Weber County (part) Remainder of Weber county 1 This date is November 15, 1990, unless otherwise noted. Utah—Ozone (1-Hour Standard) 2 Designated area Designation Classification Date 1 Type Date 1 Type Salt Lake City Area: Davis County Attainment Salt Lake County Attainment Rest of State Unclassifiable/Attainment Beaver County Box Elder County Cache County Carbon County Daggett County Duchesne County Emery County Garfield County Grand County Iron County Juab County Kane County Millard County Morgan County Piute County Rich County San Juan County Sanpete County Sevier County Summit County Tooele County Uintah County Utah County Wasatch County Washington County Wayne County Weber County 1 This date is October 18, 2000, unless otherwise noted. 2 The 1-hour ozone standard is revoked effective June 15, 2005 for all areas in Utah. The Salt Lake City area is a maintenance area for the 1-hour NAAQS for purposes of 40 CFR part 51 subpart X. Utah—PM-10 Designated Area Designation Classification Date Type Date Type Salt Lake County 3/27/2020 Attainment Utah County 3/27/2020 Attainment Ogden Area Weber County (part) City of Ogden 3/27/2020 Attainment Rest of State 1 11/15/1990 Unclassifiable 1 Denotes a single area designation for PSD baseline area purposes. Utah—1997 Annual PM 2.5 NAAQS [Primary and Secondary] Designated area Designation a Classification Date 1 Type Date Type Box Elder County, UT (part): Box Elder County (except Brigham City) Unclassifiable/Attainment Brigham City, UT: Box Elder County (part) Unclassifiable/Attainment The area surrounding Brigham City, as described by the following Townships or the portions of the following Townships in Box Elder County: T9N 2W, T9N R1W, T8N 2W Cache County, UT (part): Cache County (except Lower Cache Valley) Unclassifiable/Attainment Davis County, UT (part): Davis County (except Wasatch Front) Unclassifiable/Attainment Grantsville, UT: Tooele County (part) Unclassifiable/Attainment The area surrounding Grantsville, as described by the following Townships or the portions of the following Townships in Tooele County: T2S R6W, T2S R5W, T2S R4W, T3S R6W, T3S R5W, T3S R4W, T4S R6W, T4S R5W, T4S R4W Lower Cache Valley, UT: Cache County (part) Unclassifiable/Attainment The Cache Valley, below 6500 ft. msl. This area is described by the following list of Townships or the portions of the following Townships in Cache County: T15N R1E, T15N R2W, T15N R1W, T14N R2W, T14N R1W, T14N R1E, T13N R2W, T13N R1W, T13N R1E, T12N R2W, T12N R1W, T12N R1E, T11N R1W, T11N R1E, T10N R1W, T10N R1E, T9N R1E Salt Lake County, UT (part): Salt Lake County (except Wasatch Front) Unclassifiable/Attainment Tooele County, UT (part): Tooele County (remainder) Unclassifiable/Attainment Utah County, UT (part): Utah County (except Wasatch Front) Unclassifiable/Attainment Wasatch Front, UT: Davis County (part) Unclassifiable/Attainment The portion of the Wasatch Front residing in Davis County, as described by the following Townships or the portions of the following Townships in Davis County: T5N R3W, T5N R2W, T5N R1W, T4N R2W, T4N R1W, T3N R1W, T3N R1E, T2N R1W, T2N R1E, T1N R1W, T1N R1E. Salt Lake County (part) Unclassifiable/Attainment The portion of the Wasatch Front residing in Salt Lake County, as described by the following Townships or the portions of the following Townships in Salt Lake County: T1N R2W, T1N R1W, T1N R1E, T1S R3W, T1S R2W, T1S R1W, T1S R1E, T2S R3W, T2S R2W, T2S R1W, T2S R1E, T3S R3W, T3S R2W, T3S R1W, T3S R1E, T4S R3W, T4S R2W, T4S R1W, T4S R1E. Utah County (part) Unclassifiable/Attainment The portion of the Wasatch Front residing in Utah County, as described by the following Townships or the portions of the following Townships in Utah County: T4S R2W, T4S R1W, T4S R1E, T4S R2E, T5S R2W, T5S R1W, T5S R1E, T5S R2E, T6S R3W, T6S R2W, T6S R1W, T6S R2E, T6S R3E, T6S R1E, T7S R3W, T7S R2W, T7S R1W, T7S R1E, T7S R2E, T7S R3E, T8S R3W, T8S R2W, T8S R1W, T8S R3E, T8S R2E, T8S R1E, T9S R3W, T9S R2W, T9S R1E, T9S R3E, T9S R2E, T9S R1W, T10S 2W, T10S R2E, T10S R1E, T10S R1W, T1S R2W, T11S R1W, T12S R2W. Weber County (part) Unclassifiable/Attainment The portion of the Wasatch Front residing in Weber County, as described by the following Townships or the portions of the following Townships in Weber County: T7N R2W, T7N R1W, T7N R3W, T6N R3W, T6N R2W, T6N R1W, T5N R3W, T5N R2W, T5N R1W Weber County, UT (part): Weber County (except Wasatch Front) Unclassifiable/Attainment Rest of State: Beaver County Unclassifiable/Attainment Carbon County Unclassifiable/Attainment Daggett County Unclassifiable/Attainment Duchesne County Unclassifiable/Attainment Emery County Unclassifiable/Attainment Garfield County Unclassifiable/Attainment Grand County Unclassifiable/Attainment Iron County Unclassifiable/Attainment Juab County Unclassifiable/Attainment Kane County Unclassifiable/Attainment Millard County Unclassifiable/Attainment Morgan County Unclassifiable/Attainment Piute County Unclassifiable/Attainment Rich County Unclassifiable/Attainment San Juan County Unclassifiable/Attainment Sanpete County Unclassifiable/Attainment Sevier County Unclassifiable/Attainment Summit County Unclassifiable/Attainment Uintah County Unclassifiable/Attainment Wasatch County Unclassifiable/Attainment Washington County Unclassifiable/Attainment Wayne County Unclassifiable/Attainment a Includes Indian Country located in each county or area, except as otherwise specified. 1 This date is 90 days after January 5, 2005, unless otherwise noted. Utah—2012 Annual PM 2.5 NAAQS [Primary] Designated area 1 Designation Classification Date 2 Type Date 2 Type Statewide: Beaver County Unclassifiable/Attainment Box Elder County Unclassifiable/Attainment Cache County Unclassifiable/Attainment Carbon County Unclassifiable/Attainment Daggett County Unclassifiable/Attainment Davis County Unclassifiable/Attainment Duchesne County Unclassifiable/Attainment Emery County Unclassifiable/Attainment Garfield County Unclassifiable/Attainment Grand County Unclassifiable/Attainment Iron County Unclassifiable/Attainment Juab County Unclassifiable/Attainment Kane County Unclassifiable/Attainment Millard County Unclassifiable/Attainment Morgan County Unclassifiable/Attainment Piute County Unclassifiable/Attainment Rich County Unclassifiable/Attainment Salt Lake County Unclassifiable/Attainment San Juan County Unclassifiable/Attainment Sanpete County Unclassifiable/Attainment Sevier County Unclassifiable/Attainment Summit County Unclassifiable/Attainment Tooele County Unclassifiable/Attainment Uintah County Unclassifiable/Attainment Utah County Unclassifiable/Attainment Wasatch County Unclassifiable/Attainment Washington County Unclassifiable/Attainment Wayne County Unclassifiable/Attainment Weber County Unclassifiable/Attainment 1 Includes areas of Indian country located in each county or area, except as otherwise specified. 2 This date is April 15, 2015, unless otherwise noted. Utah—1997 24-Hour PM 2.5 NAAQS [Primary and Secondary] Designated area Designation a Classification Date 1 Type Date Type Logan, UT-ID: Cache County (part) Unclassifiable/Attainment. All portions of Cache County west of and including any portion of the following townships located within Utah: Township 15 North Range 1 East; Township 14 North Range 1 East; Township 13 North Range 1 East; Township 12 North Range 1 East; Township 11 North Range 1 East; Township 10 North Range 1 East; Township 9 North Range 1 East. Provo, UT: Utah County (part) Unclassifiable/Attainment. The area of Utah County that lies west of the Wasatch Mountain Range (and this includes the Cities of Provo and Orem) with an eastern boundary for Utah County to be defined as the following Townships: Township 3 South Range 1 East; Township 4 South Range 2 East; Township 5 South Range 3 East; Township 6 South Range 3 East; Township 7 South Range 3 East; Township 8 South Range 3 East; Township 9 South Range 3 East; Township 10 South Range 2 East. Salt Lake City, UT: Box Elder County (part) Unclassifiable/Attainment. The following Townships or portions thereof as noted (including Brigham City): Township 7 North Range 2 West; Township 8 North Range 2 West; Township 9 North Range 2 West; Township 10 North Range 2 West; Township 11 North Range 2 West; Township 12 North Range 2 West; Township 13 North Range 2 West; Township 9 North Range 3 West; Township 10 North Range 3 West; Township 11 North Range 3 West; Township 12 North Range 3 West; Township 13 North Range 3 West; Township 13 North Range 4 West; Township 12 North Range 4 West; Township 11 North Range 4 West; Township 10 North Range 4 West; Township 9 North Range 4 West; Township 13 North Range 5 West; Township 12 North Range 5 West; Township 11 North Range 5 West; Township 10 North Range 5 West; Township 9 North Range 5 West; Township 13 North Range 6 West; Township 12 North Range 6 West; Township 11 North Range 6 West; Township 10 North Range 6 West; Township 9 North Range 6 West; Township 7 North Range 1 West (portion located in Box Elder County); Township 8 North Range 1 West (portion located in Box Elder County); Township 9 North Range 1 West (portion located in Box Elder County). Davis County Unclassifiable/Attainment. Salt Lake County Unclassifiable/Attainment. Tooele County (part) Unclassifiable/Attainment. The following Townships or portions thereof as noted (including Tooele City: Township 1 South Range 3 West; Township 2 South Range 3 West; Township 3 South Range 3 West; Township 3 South Range 4 West; Township 2 South Range 4 West; Township 2 South Range 5 West; Township 3 South Range 5 West; Township 3 South Range 6 West; Township 2 South Range 6 West; Township 1 South Range 6 West; Township 1 South Range 5 West; Township 1 South Range 4 West; Township 1 South Range 7 West; Township 2 South Range 7 West; Township 3 South Range 7 West; all Sections within Township 4 South Range 7 West except for Sections 29, 30, 31 and 32; Township 4 South Range 6 West; Township 4 South Range 5 West; Township 4 South Range 4 West; Township 4 South Range 3 West. Weber County (part) Unclassifiable/Attainment. The area of Weber County that lies west of the Wasatch Mountain Range with an eastern boundary for Weber County to be defined as the following Townships (or portion thereof) extending to the western boundary of Weber County: Township 5 North Range 1 West; Township 6 North Range 1 West; all Sections within Township 7 North Range 1 West located within Weber County except for Sections 1, 2, 3, 4, 11, 12, 13 and 24; Township 7 North Range 2 West (portion located in Weber County). Rest of State: Beaver County Unclassifiable/Attainment. Box Elder County (remainder) Unclassifiable/Attainment. Cache County (remainder) Unclassifiable/Attainment. Carbon County Unclassifiable/Attainment. Daggett County Unclassifiable/Attainment. Duchesne County Unclassifiable/Attainment. Emery County Unclassifiable/Attainment. Garfield County Unclassifiable/Attainment. Grand County Unclassifiable/Attainment. Iron County Unclassifiable/Attainment. Juab County Unclassifiable/Attainment. Kane County Unclassifiable/Attainment. Millard County Unclassifiable/Attainment. Morgan County Unclassifiable/Attainment. Piute County Unclassifiable/Attainment. Rich County Unclassifiable/Attainment. San Juan County Unclassifiable/Attainment. Sanpete County Unclassifiable/Attainment. Sevier County Unclassifiable/Attainment. Summit County Unclassifiable/Attainment. Tooele County (remainder) Unclassifiable/Attainment. Uintah County Unclassifiable/Attainment. Utah County (remainder) Unclassifiable/Attainment. Wasatch County Unclassifiable/Attainment. Washington County Unclassifiable/Attainment. Wayne County Unclassifiable/Attainment. Weber County (remainder) Unclassifiable/Attainment. a Includes Indian Country located in each county or area, except as otherwise specified. 1 This date is 90 days after January 5, 2005, unless otherwise noted. Utah—2006 24-Hour PM 2.5 NAAQS [Primary and Secondary] Designated area Designation a Classification Date 1 Type Date 2 Type Logan, UT-ID: Cache County (part) June 18, 2021 Attainment All portions of Cache County west of and including any portion of the following townships located within Utah: Township 15 North Range 1 East; Township 14 North Range 1 East; Township 13 North Range 1 East; Township 12 North Range 1 East; Township 11 North Range 1 East; Township 10 North Range 1 East; Township 9 North Range 1 East. Provo, UT: Utah County (part) 12/19/2025 Attainment. The area of Utah County that lies west of the Wasatch Mountain Range (and this includes the Cities of Provo and Orem) with an eastern boundary for Utah County to be defined as the following Townships: Township 3 South Range 1 East; Township 4 South Range 2 East; Township 5 South Range 3 East; Township 6 South Range 3 East; Township 7 South Range 3 East; Township 8 South Range 3 East; Township 9 South Range 3 East; Township 10 South Range 2 East Salt Lake City, UT: Box Elder County (part) 12/19/2025 Attainment The following Townships or portions thereof as noted (including Brigham City): Township 7 North Range 2 West; Township 8 North Range 2 West; Township 9 North Range 2 West; Township 10 North Range 2 West; Township 11 North Range 2 West; Township 12 North Range 2 West; Township 13 North Range 2 West; Township 9 North Range 3 West; Township 10 North Range 3 West; Township 11 North Range 3 West; Township 12 North Range 3 West; Township 13 North Range 3 West; Township 13 North Range 4 West; Township 12 North Range 4 West; Township 11 North Range 4 West; Township 10 North Range 4 West; Township 9 North Range 4 West; Township 13 North Range 5 West; Township 12 North Range 5 West; Township 11 North Range 5 West; Township 10 North Range 5 West; Township 9 North Range 5 West; Township 13 North Range 6 West; Township 12 North Range 6 West; Township 11 North Range 6 West; Township 10 North Range 6 West; Township 9 North Range 6 West; Township 7 North Range 1 West (portion located in Box Elder County); Township 8 North Range 1 West (portion located in Box Elder County); Township 9 North Range 1 West (portion located in Box Elder County). Davis County 12/19/2025 Attainment. Salt Lake County 12/19/2025 Attainment. Tooele County (part) 12/19/2025 Attainment. The following Townships or portions thereof as noted (including Tooele City): Township 1 South Range 3 West; Township 2 South Range 3 West; Township 3 South Range 3 West; Township 3 South Range 4 West; Township 2 South Range 4 West; Township 2 South Range 5 West; Township 3 South Range 5 West; Township 3 South Range 6 West; Township 2 South Range 6 West; Township 1 South Range 6 West; Township 1 South Range 5 West; Township 1 South Range 4 West; Township 1 South Range 7 West; Township 2 South Range 7 West; Township 3 South Range 7 West; all Sections within Township 4 South Range 7 West except for Sections 29, 30, 31 and 32; Township 4 South Range 6 West; Township 4 South Range 5 West; Township 4 South Range 4 West; Township 4 South Range 3 West. Weber County (part) 12/19/2025 Attainment. The area of Weber County that lies west of the Wasatch Mountain Range with an eastern boundary for Weber County to be defined as the following Townships (or portion thereof) extending to the western boundary of Weber County: Township 5 North Range 1 West; Township 6 North Range 1 West; all Sections within Township 7 North Range 1 West located within Weber County except for Sections 1, 2, 3, 4, 11, 12, 13 and 24; Township 7 North Range 2 West (portion located in Weber County). Rest of State: Beaver County Unclassifiable/Attainment Box Elder County (remainder) Unclassifiable/Attainment Cache County (remainder) Unclassifiable/Attainment Carbon County Unclassifiable/Attainment Daggett County Unclassifiable/Attainment Duchesne County Unclassifiable/Attainment Emery County Unclassifiable/Attainment Garfield County Unclassifiable/Attainment Grand County Unclassifiable/Attainment Iron County Unclassifiable/Attainment Juab County Unclassifiable/Attainment Kane County Unclassifiable/Attainment Millard County Unclassifiable/Attainment Morgan County Unclassifiable/Attainment Piute County Unclassifiable/Attainment Rich County Unclassifiable/Attainment San Juan County Unclassifiable/Attainment Sanpete County Unclassifiable/Attainment Sevier County Unclassifiable/Attainment Summit County Unclassifiable/Attainment Tooele County (remainder) Unclassifiable/Attainment Uintah County Unclassifiable/Attainment Utah County (remainder) Unclassifiable/Attainment Wasatch County Unclassifiable/Attainment Washington County Unclassifiable/Attainment Wayne County Unclassifiable/Attainment Weber County (remainder) Unclassifiable/Attainment a Includes Indian Country located in each county or area, except as otherwise specified. 1 This date is 30 days after November 13, 2009, unless otherwise noted. 2 This date is July 2, 2034, unless otherwise noted. Utah—NO 2 (1971 Annual Standard) Designated area Does not meet primary standards Cannot be classified or better than national standards Entire State X Utah—NO 2 (2010 1-Hour Standard) Designated area Designation a Date 1 Type Cache County Unclassifiable/Attainment. Davis County Unclassifiable/Attainment. Salt Lake County Unclassifiable/Attainment. Utah County Unclassifiable/Attainment. Weber County Unclassifiable/Attainment. Rest of State Unclassifiable/Attainment. a Includes Indian Country located in each county or area, except as otherwise specified. 1 This date is 90 days after October 31, 2011, unless otherwise noted. Utah—1997 8-Hour Ozone NAAQS [Primary and Secondary] Designated area Designation a Category/classification Date 1 Type Date 1 Type Salt Lake City Area: Davis County Unclassifiable/Attainment Salt Lake County Unclassifiable/Attainment Rest of State: Unclassifiable/Attainment Beaver County Box Elder County Cache County Carbon County Daggett County Duchesne County Emery County Garfield County Grand County Iron County Juab County Kane County Millard County Morgan County Piute County Rich County San Juan County Sanpete County Sevier County Summit County Tooele County Uintah County Utah County Wasatch County Washington County Wayne County Weber County a Includes Indian Country located in each county or area, except as otherwise specified. 1 This date is June 15, 2004, unless otherwise noted. Utah—2008 8-Hour Ozone NAAQS [Primary and Secondary] Designated area Designation Classification Date 1 Type Date 1 Type Uinta Basin, UT: 2 Unclassifiable Duchesne County Uintah County Ute Indian Tribe of the Uintah & Ouray Reservation 3 Rest of State and Rest of Indian Country Unclassifiable/Attainment 1 This date is July 20, 2012, unless otherwise noted. 2 Excludes Indian country located in each area, unless otherwise noted. 3 Includes Indian country of the tribe listed in this table located in the identified area. Information pertaining to areas of Indian country in this table is intended for CAA planning purposes only and is not an EPA determination of Indian country status or any Indian country boundary. EPA lacks the authority to establish Indian country land status, and is making no determination of Indian country boundaries, in this table. Utah—2015 8-Hour Ozone NAAQS [Primary and Secondary] Designated area 1 Designation Classification Date 2 Type Date 2 Type Northern Wasatch Front, UT Nonattainment February 5, 2026 Moderate. Davis County. Salt Lake County. Tooele County (part): In Tooele County, the following Townships or portions thereof as noted (including Tooele City): Township 1 North Range 6 West. Township 1 North Range 7 West. Township 1 North Range 8 West. Township 2 North Range 6 West. Township 2 North Range 7 West. Township 2 North Range 8 West. Township 3 North Range 7 West. Township 3 North Range 8 West. Township 1 South Range 3 West. Township 1 South Range 4 West. Township 1 South Range 5 West. Township 1 South Range 6 West. Township 1 South Range 7 West. Township 1 South Range 8 West. Township 2 South Range 3 West. Township 2 South Range 4 West. Township 2 South Range 5 West. Township 2 South Range 6 West. Township 2 South Range 7 West. Township 2 South Range 8 West. Township 3 South Range 3 West. Township 3 South Range 4 West. Township 3 South Range 5 West. Township 3 South Range 6 West. Township 3 South Range 7 West. Township 3 South Range 8 West. Township 4 South Range 3 West. Township 4 South Range 4 West. Township 4 South Range 5 West. Township 4 South Range 6 West. All sections within Township 4 South Range 7 West except for section 31. Township 4 South Range 8 West. Weber County (part): All portions of Weber County west of and including Townships 5, 6, and that portion of 7 North Range 1 West that are west of the ridgeline that traces the Wasatch Mountains from the southeast corner of the township to the easternmost extension of the county boundary within the township. Southern Wasatch Front, UT Nonattainment Marginal. Utah County (part): All portions of Utah County west of and including any portion of the following townships located within Utah County: Township 3 South Range 1 East. Township 4 South Range 2 East. Township 5 South Range 3 East. Township 6 South Range 3 East. Township 7 South Range 3 East. Township 8 South Range 3 East. Township 9 South Range 3 East. Township 10 South Range 2 East. Uinta Basin, UT 3 Nonattainment January 15, 2025 Moderate. Duchesne County (part): All land in Duchesne County below a contiguous external perimeter of 6,250 ft. in elevation. All areas within that contiguous external perimeter are included in the nonattainment area—including mesas and buttes which may have an elevation greater than 6,250 ft., but which are surrounded on all sides by land lower than 6,250 ft. Additionally, areas that fall outside the 6,250 ft. contiguous external perimeter that have elevations less than 6,250 ft. are excluded from the nonattainment area. The boundary is defined by the 6,250 ft. contour line created from the 2013 USGS 10-meter seamless Digital Elevation Model (USGS NED n41w1101/3 arc-second 2013 1 × 1 degree IMG). Uintah County (part): All land in Uintah County below a contiguous external perimeter of 6,250 ft. in elevation. All areas within that contiguous external perimeter are included in the nonattainment area—including mesas and buttes which may have an elevation greater than 6,250 ft., but which are surrounded on all sides by land lower than 6,250 ft. Additionally, areas that fall outside the 6,250 ft. contiguous external perimeter that have elevations less than 6,250 ft. are excluded from the nonattainment area. The boundary is defined by the 6,250 ft. contour line created from the 2013 USGS 10-meter seamless Digital Elevation Model (USGS NED n41w1101/3 arc-second 2013 1 x 1 degree IMG). Beaver County 1/16/2018 Attainment/Unclassifiable Box Elder Attainment/Unclassifiable Cache County Attainment/Unclassifiable Carbon County Attainment/Unclassifiable Daggett County Attainment/Unclassifiable Duchesne County (part) remainder Attainment/Unclassifiable Emery County 1/16/2018 Attainment/Unclassifiable Garfield County 1/16/2018 Attainment/Unclassifiable Grand County Attainment/Unclassifiable Iron County 1/16/2018 Attainment/Unclassifiable Juab County Attainment/Unclassifiable Kane County 1/16/2018 Attainment/Unclassifiable Millard County 1/16/2018 Attainment/Unclassifiable Morgan County Attainment/Unclassifiable Piute County 1/16/2018 Attainment/Unclassifiable Rich County Attainment/Unclassifiable San Juan County 1/16/2018 Attainment/Unclassifiable Sanpete County Attainment/Unclassifiable Sevier County 1/16/2018 Attainment/Unclassifiable Summit County Attainment/Unclassifiable Tooele County (part) remainder Attainment/Unclassifiable Uintah County (part) remainder Attainment/Unclassifiable Utah County (part) remainder Attainment/Unclassifiable Wasatch County Attainment/Unclassifiable Washington County 1/16/2018 Attainment/Unclassifiable Wayne County 1/16/2018 Attainment/Unclassifiable Weber County (part) remainder Attainment/Unclassifiable 1 Includes any Indian country in each county or area, unless otherwise specified. EPA is not determining the boundaries of any area of Indian country in this table, including any area of Indian country located in the larger designation area. The inclusion of any Indian country in the designation area is not a determination that the state has regulatory authority under the Clean Air Act for such Indian country. 2 This date is August 3, 2018, unless otherwise noted. 3 The EPA is designating portions of the Uinta Basin as “nonattainment,” including both Tribal and State lands. The Ute Tribe has air quality planning jurisdiction in the areas of Indian country included in the Uinta Basin nonattainment area, while the State of Utah has air quality planning jurisdiction in the areas of State land included in the Uinta Basin nonattainment area. Utah—2008 Lead NAAQS Designated area Designation for the 2008 NAAQS a Date 1 Type Whole State Unclassifiable/Attainment. a Includes Indian Country located in each county or area, except as otherwise specified. 1 December 31, 2011 unless otherwise noted. [43 FR 8964, Mar. 3, 1978] Editorial Note: For Federal Register citations affecting § 81.345, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www.govinfo.gov.