Sections: State Implementation Plan (SIP)

The Clean Air Act (CAA) of 1970 required the creation of National Ambient Air Quality Standards (NAAQS) to protect both public health and the environment. To meet this requirement, the U.S. Environmental Protection Agency (EPA) set air quality standards for seven pollutants: total suspended particulates, sulfur dioxide, carbon monoxide, hydrocarbons, ozone, nitrogen dioxide, and lead. The CAA also required each state to develop and submit a State Implementation Plan (SIP), outlining how it would achieve, maintain, and enforce these standards. This original SIP is often referred to as the infrastructure or foundational SIP.

Utah submitted its original SIP in January 1972. Upon review, the EPA determined that portions of the plan were not adequate. As allowed under the CAA, the EPA replaced those sections with federally prepared versions. When the deadlines for reaching the standards arrived, pollution levels had dropped in many cases—but not enough to meet the NAAQS. In particular, there was no noticeable improvement in particulate matter levels.

Since many areas across the country still had not met the NAAQS, Congress amended the CAA in 1990. This led to renewed efforts to meet the standards. States were now required to identify “nonattainment areas”—regions where monitoring data or air quality models showed that pollution levels exceeded the standards. States then had to update their SIPs to address those areas and meet the NAAQS. These SIP revisions are often referred to as attainment SIPs or maintenance SIPs depending on the situation. Since the origin of the CAA and subsequent amendments, areas in Utah have been in and out of compliance for ozone, carbon monoxide, sulfur dioxide, total suspended particles, PM₁₀ and PM_2.5. Because there have been so many changes to federal, state, and local air quality programs in the last 35 years, there is not a single definitive document that contains all of the SIP requirements. SIPs are generally a collection of regulatory, non-regulatory, and quasi-regulatory elements that continue to be added to over time. This page captures Utah’s recorded SIP revisions to date.

Infrastructure SIP

When EPA establishes a new or revised NAAQS under CAA sections 108 and 109, all states are required to develop and submit to EPA a plan that provides for the implementation, maintenance, and enforcement of the new or revised air quality standard. This type of submission is referred to as an infrastructure state implementation plan, or iSIP.

These plans have several required parts to them that are commonly referred to as “iSIP elements.” An iSIP submission meets these required elements by demonstrating that the state laws, rules, governmental structure, and other resources—or the “infrastructure” of the state—are sufficient to implement, maintain, and enforce the air quality standards statewide.

Section I: Legal Authority

Identifies statutory authorizations for development of the SIP.

Last Amended: Early 1980s
EPA Approved: Early 1980s

Section II: Review of New and Modified Air Pollution Sources

New or modified sources of air pollution must submit plans to the Division and receive an Approval Order before operating.

Last Amended: Early 1980
EPA Approval: Early 1980s

Section III: Source Surveillance

Sources are required to submit reports on their emissions and operations.

Last Amended: Early 1980
EPA Approval: Early 1980s

Section IV: Ambient Air Monitoring Program

Includes a description of the purposes of the air monitoring program. For monitoring sites and other information, see the monitoring portion of the plan pertaining to each pollutant.

Last Amended: Early 1980
EPA Approval: Early 1980s

Section V: Resources

Information regarding resources to carry out the state’s air quality programs.

Last Amended: Early 1980
EPA Approval: Early 1980s

Section VI: Intergovernmental Cooperation

Listing of federal, state, and local agencies involved in protecting air quality in Utah.

Last Amended: Early 1980
EPA Approval: Early 1980s

Section VII: Prevention of Air Pollution Emergency Episodes

Brief description of plans to avoid reaching emergency levels of air pollution. Such levels have not been reached in Utah. More specific details are found in Administrative Rule R307-105-2.

Last Amended: Early 1980
EPA Approval: Early 1980s

Section VIII: Prevention of Significant Deterioration

Describes the program to protect areas of the state where the air is clean.

Last Amended: March 8, 2006
EPA Approval: Pending

Section XII: Transportation Conformity Consultation

Outreach activities when preparing state plans.

Last Amended: May 2, 2007
EPA Approval: Early 1980s

Section XIII: Analysis of Plan Impact

A brief discussion of the expected impacts of the various plans.

Last Amended: Early 1980
EPA Approval: Early 1980s

Section XIV: Comprehensive Emission Inventory

Selected inventories of emissions from a variety of causes are presented by county location for 1977 and 1983. More current and detailed emission inventories are available. Inventory information also is discussed in the plans for each pollutant.

Last Amended: Early 1980
EPA Approval: Early 1980s

Section XVI: Public Notification

The plan to report monitored levels of emissions daily and annually.

Last Amended: Early 1980
EPA Approval: Early 1980s

Section XVII: Visibility Protection

Plan to protect visibility, especially within the boundaries of the five national parks located in Utah and requiring protection under federal law. For further discussion, see the final recommendations of the Grand Canyon Visibility.

Last Amended: December 1992
EPA Approval: April 1997
Further Information: Western Regional Air Partnership

Section XXIII: Interstate Transportation

When a new NAAQS is promulgated, the CAA requires states to submit a SIP under section 110(a)(2)(D)(i) to address interstate transport of emissions that would affect nonattainment and maintenance areas in neighboring states.

NAAQS iSIPs

Section IX: Control Measures for Area and Point Sources

This section includes plans for health-based standard pollutants. Each addresses a different pollutant, with an overview of historical developments, measured levels at various locations, strategies to control the pollutant, projections of population and pollutant growth in the future, contingency plans in case the control strategies fail, and a mobile source emissions budget. Included are both attainment SIPs and maintenance SIPs depending on the status of the airshed.

IX.A: Particulate Matter

Generally called PM10, for Salt Lake, Southern Davis, and Utah counties.

Last Amended: July 3, 2002, Effective September 5, 2002
EPA Approval: Published December 23, 2002, at 67 FR 78181

IX.A.11: PM10 Maintenance Plan for Salt Lake County

Last Amended: December 2, 2015, Effective December 3, 2015
EPA Approval: Published February 26, 2020, at 85 FR 10989

IX.A.12: PM10 Maintenance Plan for Utah County

Last Amended: December 2, 2015, Effective December 3, 2015
EPA Approval: Published February 26, 2020, at 85 FR 10989

IX.A.13: PM10 Maintenance Plan for Ogden City

Last Amended: December 2, 2015, Effective December 3, 2015
EPA Approval: Published February 26, 2020, at 85 FR 10989

IX.A.21: PM2.5 State Implementation Plan for Salt Lake City

Salt Lake, Weber, Davis, and portions of Box Elder and Tooele counties.

Adopted: December 3, 2014
EPA Approval: Pending

IX.A.22: PM2.5 State Implementation Plan for Provo

Adopted: December 3, 2014
EPA Approval: Pending

IX.A.23: PM2.5 State Implementation Plan for Logan

Last Amended: December 3, 2014
EPA Approval: May 19th, 2021, at 86 FR 27035

IX.A.27: PM2.5 Maintenance Provisions for Provo, Utah

Air Quality Board Adopted: December 4, 2019
EPA Approval: Pending

IX.A.28: PM2.5 Maintenance Provisions for Logan, Utah-Idaho

Air Quality Board Adopted: December 4, 2019
EPA Approval: May 19th, 2021, at 86 FR 27035

IX.A.31: Serious Area PM2.5 SIP

For the Salt Lake Nonattainment Area.

Adopted: January 2, 2019
EPA Approval: Pending

IX.A.36: PM2.5 Maintenance Provisions for Salt Lake City, Utah

Air Quality Board Adopted: December 4, 2019
EPA Approval: Pending

IX.B. Sulfur Dioxide SIP (Conditionally Approved)

EPA Conditional Approval: 1985

IX.B: Sulfur Dioxide SIP

Salt Lake and portions of Tooele Counties.

Last Amended: 1992; EPA Approval: 1994.

IX.B.6: Sulfur Dioxide Maintenance Plan

Maintenance Plan for Salt Lake and portions of Tooele Counties.

Last Amended: January 5, 2005
EPA Approval: Withdrawn on November 12, 2019

IX.C.1-5: Carbon Monoxide SIP

Original implementation plan for Salt Lake, Ogden, and 1984 plan for Provo-Orem.

Last Amended: December 9, 1993
EPA Approval: Approved.

IX.C.6: Carbon Monoxide Maintenance Plan for Provo, Utah

Last Amended: June 6, 2018
EPA Approval: March 2, 2020

IX.C.7: Carbon Monoxide Maintenance Plan for Salt Lake City, Utah

Last Amended: October 6, 2004
EPA Approval: Plan approved October 26, 2005

IX.C.8: Carbon Monoxide Maintenance Plan for Ogden, Utah

Last Amended: November 3, 2004
EPA Approval: Plan approved September 14, 2005 (Redesignated to attainment March 9, 2001)

IX.D.1: Ozone SIP for Salt Lake and Davis Counties

Original Ozone plan.

Last Amended: September 30, 1993
EPA Clean Data Determination: August 18, 1997, 62 FR 38,213

IX.D.2: Ozone Maintenance Plan for Salt Lake and Davis Counties

Last Amended: September 9, 1998
EPA Approval: August 18, 1997, 62 FR 38213

IX.D: 8-Hour Ozone Maintenance Provisions for Salt Lake and Davis Counties

Last Amended: January 3, 2007
EPA Approval: September 26, 2013 (78 FR 59,242)

IX.D.11: SIP 2015 Ozone NAAQS Northern Wasatch Front Moderate Nonattainment Area

Moderate State Implementation Plan for the Northern Wasatch Front Ozone Nonattainment Area including Davis, Salt Lake, Tooele, and Weber counties.

Last Amended: November 2024
EPA Approval: Pending

IX.E: Nitrogen Oxides

Last Amended: Early 1980
EPA Approval: Early 1980s

IX.F: Lead

The SIP for lead includes a historical examination of lead levels prior to the removal of lead from gasoline for vehicles.

Last Amended: Early 1980
EPA Approval: Early 1980s

SIP Section IX Part H sets emission limits and controls at major point sources. The different sections of Part H are for different pollutant attainment SIPs over time.

IX.H.1-H.4: PM10 Emissions Limits and Operating Practices

Salt Lake and Provo Nonattainment Areas

Last Amended: December 2, 2020
EPA Approval: Published February 26, 2020, at 85 FR 10989

IX.H.11-H.13: PM2.5 Emissions Limits and Operating Practices

Salt Lake and Provo Nonattainment Areas

Last Amended: May 7, 2025
EPA Approval: Pending

IX.H.21-H.23: Regional Haze Emissions Limits and Operating Practices

Last amended July 6, 2022
EPA Approval: Pending

IX.H.31-H.32: Ozone Emissions Limits and Operating Practices

Emission limits and operating practices for ozone nonattainment areas including Davis, Salt Lake, Tooele, and Weber counties.

Last amended: September 12, 2023
EPA Approval: Pending

Other SIP Sections

Section X: Vehicle Inspection and Maintenance Program

This section demonstrates compliance with the federal Basic I/M standards specified in 40 CFR 51 Subpart S, “Inspection/Maintenance Program Requirements” last amended at 66 FR 18156, April 5, 2001, as required by Section 182 of the Clean Air Act. The EPA I/M rule establishes a program performance standard and other requirements that will provide more effective control of carbon monoxide and ozone precursor emissions. The Utah State Implementation Plan establishes more stringent requirements for each designated I/M county (Davis, Salt Lake, Utah, Weber, and Cache Counties).

X.A: General Requirements Vehicle Inspection and Maintenance Program

General Requirements for all counties.

Last Amended: February 7, 2024
EPA Approval: May 19, 2021

X.B: Davis County Vehicle Inspection and Maintenance Program

Davis County Vehicle Inspection and Maintenance Program.

Last Amended: February 7, 2024
EPA Approval: February 14, 2006

X.C: Salt Lake County Vehicle Inspection and Maintenance Program

Salt Lake County Vehicle Inspection and Maintenance Program.

Last Amended: October 6, 2004
EPA Approval: August 1, 2005

X.D: Utah County Vehicle Inspection and Maintenance Program

Utah County Vehicle Inspection and Maintenance Program

Last Amended: December 5, 2012
EPA Approval: January 3, 2006

X.E: Weber County Vehicle Inspection and Maintenance Program

Weber County Vehicle Inspection and Maintenance Program.

Last Amended: March 4, 2020
EPA Approval: September 14, 2005

X.F: Cache County Vehicle Inspection and Maintenance Program

Cache County Vehicle Inspection and Maintenance Program.

Last Amended: February 5, 2025
EPA Approval: Pending

Section XI: Other Control Measures for Mobile Sources

Transportation control measures.

Last Amended: February 9, 2000
EPA Approval: June 14, 2000

Section XVIII: Demonstration of GEP Stack Height

Analysis of the stack heights of various industrial sources of emissions to ensure that their emissions are adequately reduced and are not simply being “exported” to other locations by atmospheric conditions.

Last Amended: 1992
EPA Approval: 1994
Further Information: R307-410-5

Section XIX: Small Business Assistance Program

This is a description of plans for better coordination and communication with small businesses.

Last Amended: December 18, 1992
EPA Approval: N/A
Further Information: DEQ’s Small Business Assistance Program

Section XX: Regional Haze – First Implementation Period

Plan to improve visibility in national parks by reducing widely transported particles that cause haze.

Last Amended: June 24, 2019
EPA Approval: Approved
Further Information:
- Regional Haze
- Western Regional Air Partnership

Section XX.A: Regional Haze – Second Implementation Period

Plan to improve visibility in national parks by reducing widely transported particles that cause haze.

Last Amended: July 6, 2022
EPA Approval: Partial approval/partial disapproval
Further Information:
- Regional Haze
- Western Regional Air Partnership

Section XXI: Diesel Inspection and Maintenance Program

A description of the diesel vehicle emission inspection and maintenance program operated by urban counties. A multitude of appendices are available only on paper.

Last Amended: July 12, 1995

Section XXII: General Conformity

This section expresses Utah’s compliance with federal requirements for general conformity, 40 CFR Part 51.851, by following 40 CFR Part 93. Part 93 is incorporated by reference under R307-115.

Last Amended: October 4, 1995
EPA Approval: November 19, 1999

For more information or questions contact Becky Close ([email protected]), (801) 536-4013.

Last Updated:

November 26, 2025 12:04 PM

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State Implementation Plan (SIP)