Emission Sources
Sources of Utah’s Emissions
The Utah Department of Environmental Quality’s Division of Air Quality (DAQ) works deliberately and tirelessly to understand the sources of air-quality-deteriorating-emissions and how to reduce them to improve air quality. One way to gain more information about Utah’s air quality, and ways we can improve it, is the emission inventory that DAQ compiles. The emissions inventory is one method used by the state to assess the level of pollutants released into the air from various sources.
Point Sources
Point sources are stationary, commercial, or industrial sources. Several criteria categorize a facility into point source emissions inventory reporting rather than being part of the area source emissions inventory. The point source annual emission inventory for criteria pollutants is collected under authority of Utah Administrative Code. The inventory information is required to track State Implementation Plan (SIP) progress, calculate the operating permit program emission fee, fulfill annual reporting requirements to EPA, and supply information to the general public. More information on reporting Point Source Emission Inventories.
Area Sources
Area sources are stationary sources that are too small or too numerous to be treated as individual point sources. The area source inventory is determined from local demographic information, state energy and agricultural statistical data, specific information surveys, and submitted inventories. Source categories range from agricultural dust and outdoor grilling to residential wood combustion, solvent use, and upstream oil and gas facilities. The oil and gas inventory is unique in the area source inventory as rather than using surrogate activity data and generic emission factors, oil and gas companies submit an inventory for their facilities.
Biogenic sources comprise the natural (non-anthropogenic, such as forests, vegetation, and soils) area sources contribution to VOCs and “event” emission sources, such as wildfires, contribute various pollutants to the airshed. Both of these pollution sources are also under the purview of area sources.
Note: The area source inventory remains in development and experiences significant fluctuations. Frequently one inventory is not readily comparable to another due to changing methods, new data sources and new emissions categories.
Mobile Sources
The mobile source inventory includes both on-road and non-road sources. Vehicles traveling on paved roads and highways comprise the on-road sector, which includes cars, light-duty trucks, heavy-duty trucks, and motorcycles. Non-road mobile sources include a wide variety of internal combustion engines and vehicles not operating on roads and highways, such as diesel locomotives, aircraft, airport ground support equipment, and eleven groups of motorized vehicles and equipment found in the non-road module of the current EPA emissions model “MOVES”. These groups include recreational, construction, industrial, lawn & garden, agricultural, commercial, logging, underground mining, miscellaneous oil field equipment, miscellaneous railroad equipment, and marine and pleasure craft.
