Salt Lake City faces significant air quality challenges in both the summer and winter. In the winter, the Wasatch Front’s unique geography leads to periodic temperature inversions which trap cold air underneath a layer of warm air. This acts like a “lid” on the Salt Lake Valley—causing particulate pollution to double every day. In the summer, pollution from cars, industry, and a multitude of chemical products, combined with high temperatures and bright sunshine, lead to harmful ozone levels.

According to the Utah Department of Air Quality’s 2022 Annual Report:

Mobile sources are the greatest source of emissions in the Wasatch Front. That includes cars, semi-trucks, trains, buses, and airplanes.

On-road mobile sources produce about 39% of the annual man-made pollution (NOx, PM2.5 exhaust, and VOC) along the Wasatch Front. Although heavy-duty diesel vehicles account for only 7.5% of the vehicle miles traveled, they produce over 30% of that mobile source pollution. Mobile sources have historically been the largest source of emissions, but with the transition to cleaner vehicles and Tier 3 fuel, this is changing.

Area Sources are the second greatest source of emissions in the Wasatch Front. Area sources include homes, commercial buildings, construction, and small industry. This sector is anticipated to become the largest source of emissions as mobile source emissions go down.  

Point sources, stationary industrial and commercial sites emitting more than 100 tons per year of a regulated pollutant, are the third greatest source of emissions.

The Utah Department of Air Quality regulates most of these sectors. But Salt Lake City is taking action in every way we can– with our internal operations and the creation of external policies and programs– to support air quality and reduce pollution across the community.

Click on the images below to learn more about what Salt Lake City is doing to improve air quality and how you can help.