Air Quality

Due to its unique topography and quickly growing population, Utah experiences a number of challenges in maintaining healthy air quality for its citizens, particularly in the more densely populated areas along the Wasatch Front. Rio Tinto Kennecott is aware of these issues and the impacts we have on air quality. As such, we are an active participant in air quality processes to reduce impacts on Utah’s air quality.

Kennecott’s emission contribution
Inventory analysis conducted by the Utah Division of Air Quality (UDAQ) indicates that Kennecott’s annual emissions are a minor contributor to total annual emissions in the Salt Lake air shed, as compared to area sources — such as urban activities, home heating, small businesses, solvent use and graphics; and mobile sources — such as cars, trucks and other mobile equipment.

More specifically, based upon the most recent UDAQ data, Kennecott’s total annual emissions of PM2.5 particles and PM2.5 precursors represent approximately 4.4 percent of total annual PM2.5 and precursor emissions in the air shed. This compares with 62.3 percent from area sources and 26.9 percent from mobile sources. (The Salt Lake air shed is currently in a non-attainment status with the U.S. EPA’s National Ambient Air Quality Standard (NAAQS) for PM2.5. In this regard, PM2.5 and PM2.5 precursors are the primary emissions of concern affecting Salt Lake City’s winter inversion episodes.)

PM2.5 = particulates smaller than 2.5 micrometers in diameter.

PM2.5 precursors = emissions that are not particles originally but which can turn into particles when they react in the atmosphere. Precursors include SO2, NOX, and VOCs.

This information is further summarized in the graph below:

As an active participant in air quality processes, Kennecott is proud of our continuous improvement in reducing our emissions. We are also proud to work with other air quality improvement champions in the community to support the reduction of emissions within the Salt Lake air shed.

Some key specific examples include:

• Combined heat & power plants: Kennecott has installed a 6.2 MW Combined Heat and Power (CHP) system at the Kennecott refinery. CHP systems reduce air emissions by more than 90 percent compared to traditional steam and electric systems.

• Smelter cogeneration: Kennecott’s smelter captures and converts the waste heat from the flash smelting and converting furnaces to generate about two-thirds of its electrical demands.

• Smelter emissions capture: Kennecott’s smelter captures 99.9 percent of all sulfur emissions and is considered one of the cleanest in the world.

• Upgraded truck fleet: Larger payload capacity and higher efficiency engines result in a reduction in tailpipe emissions.

• LEED-certified buildings: Kennecott uses several high-performing LEED-certified buildings. The Rio Tinto Regional Center was the first LEED Platinum-rated building in Utah.

• Public transportation: Kennecott played a pivotal role in the development of the TRAX Mid-Jordan light rail line, which connects Daybreak with the north-south main line.

• Idling program: Kennecott has implemented two vehicle idling reduction programs: one for light/medium duty vehicles throughout the operation and one for haul trucks at the mine. The idling programs have resulted in a reduction in tailpipe emissions.

• CNG vehicle program: Kennecott has implemented a CNG vehicle pilot program resulting in a reduction in tailpipe emissions.

• Renewable energy research: Kennecott has installed more than 40 kWs of solar and wind generation at seven individual project sites.