Air Quality Conformity and Trends
Air quality along the Wasatch Front has improved markedly over the past two decades. Salt Lake City was recently designated by the Environmental Protection Agency (EPA) to be free of carbon monoxide (CO) pollution after being designated as a CO non-attainment area 42 years ago in 1978. This is primarily due to newer vehicles that substantially reduced emissions and increasing options for residents to walk, bike, or use transit. Continuing to improve air quality along the Wasatch Front, however, remains a challenge now and in the future.
Air quality is central to WFRC's work and responsibilities. WFRC considers air quality impacts when developing the Wasatch Choice Vision and the Regional Transportation Plan (RTP). The RTP must meet the air quality standards identified in the Utah State Implementation Plan (SIP), which implements the federal air quality standards for the State of Utah. This means that the vehicle emissions resulting from the transportation projects proposed in the RTP may not exceed the level set for them in the SIP.
Portions of the WFRC region have been designated as a non-attainment area for fine particulate matter (PM2.5) and for ozone; and Salt Lake County and Ogden City are also designated as non-attainment for coarse particulate matter (PM10). Fortunately, emissions from transportation sources are projected to decline by 52% from 2019 to 2050 due to improvements in car and truck emission technology, increased transit utilization, and other travel choices. Despite this progress, there is still more that we need to do.
As we work to provide transportation choices and plan our communities in a way that is consistent with the regional growth principles of the Wasatch Choice Vision, our air quality will benefit from cleaner vehicles, more transit choices, shorter and fewer auto trips, and reduced congestion.
What is air quality conformity?
Air quality conformity is a federal requirement in the context of transportation plans and air quality goals. Emissions from vehicles may not exceed limits defined in the SIP, a plan for reducing and controlling emissions in the state to meet National Ambient Air Quality Standards (NAAQS). The RTP and the Transportation Improvement Program (TIP) developed by WFRC must meet this air quality conformity requirement for all of the years defined in these plans. This means that vehicle emissions estimated for the last year of the RTP may not exceed the budget identified in the SIP. Failure to meet conformity requirements restricts spending of federal and local transportation funds to safety, maintenance, or projects on minor roads only. If conformity requirements are not met, transportation funds may not be used to add capacity to principal arterials and freeways or to expand fixed guideway transit facilities.
All current transportation plans and programs for the Wasatch Front region conform to the established SIP and its various sections. Changes will likely continue to be made to federal air quality standards, which will require corresponding changes to the SIP.
What is a State Implementation Plan (SIP)?
Wasatch Front Region Non-Attainment Designations
| Area | Designation | Pollutant |
|---|---|---|
| Northern Wasatch Front (including Salt Lake and Davis Counties, as well as portions of Weber and Tooele Counties) | Marginal Non-Attainment Area | Ozone |
| Ogden City | Maintenance Area | Carbon Monoxide (CO) |
| Moderate Non-Attainment Area | Particulate Matter (PM10) | |
| Salt Lake County | Maintenance Area | Particulate Matter (PM10) |
Related Resources
Contact
For additional information, please contact:
Fariba Soltani
Transportation Analyst
