Montana Rail Link cuts costs and emissions with help from the EPA

The following is a guest post from Ann W. Cundy, Senior Transportation Planner, Missoula Office of Planning and Grants

Transportation planners, public health professionals and a private railroad in Missoula, Montana are working together to reduce diesel emissions and improve air quality.

The project is possible thanks to a grant from the U.S. Environmental Protection Agency’s National Clean Diesel Campaign, which works with public agencies, private companies and community groups to reduce diesel emissions and promotes clean air strategies. The City of Missoula recognized the Clean Diesel Campaign as an opportunity to improve its air quality, protect public health, reduce greenhouse gas emissions and save money for Montana Rail Link – truly meeting a triple bottom line.

Diesel smoke from idling locomotives has long been an issue for residents in neighborhoods adjacent to Missoula’s downtown rail yard. Older engines idle 24/7 when temperatures drop below 40˚F – up to 10 months of the year in Missoula – to keep engine oil and water warm. Making these emissions even worse is the geography of the Missoula valley itself, which traps pollutants under a layer of air in cold winter months.

In response to these concerns and recognizing an opportunity to cut fuel costs, Montana Rail Link (MRL) decided to reduce locomotive idling. To do this MRL began upgrading its fleet with fuel-efficient retrofits, and estimated the full project would take five years to complete.

Thanks to the $1.13 million Clean Diesel grant, however, MRL retrofitted its 34 remaining locomotives in just one year – a fifth the time originally estimated. The company added new “start-stop” technology to train engines as well as auxiliary power units (APUs), which circulate oil and water through the locomotive’s main engine to keep it warm. APUs run when a locomotive stands unused for two hours or more in temperatures below 40˚F, and are one tenth the size of a locomotive’s main engine. APUs consume only half a gallon of fuel per hour instead of the four to five gallons per hour used by an idling main engine, and reduce the number of hours locomotives must idle by 80%. Using this new technology MRL saved 951,500 gallons of fuel in the first year alone.

Those fuel savings resulted in the reduction of 10,932 tons of criteria pollutants in Missoula’s airshed, including particulate matter, hydrocarbons, carbon monoxide, sulfur dioxide, NOx, and carbon dioxide. While improvements in Missoula’s air quality as a direct result of the APUs cannot be measured accurately, complaints to the City-County Health Department about locomotive idling since the start of the APU installations have have fallen to zero.

The EPA Clean Diesel Campaign helped improve air quality near MRL’s Missoula rail yard and reduced costs in the process. As part of their grant agreement, MRL also adopted a policy to always use APUs or another idle reduction technology when locomotives idle at temps below 40˚F, ensuring that these reductions – and savings – will be made permanent.

Read more about the U.S. EPA’s National Clean Diesel Campaign at

Photo of the Montana Rail Link’s Clean Diesel trains by Roger Millar, Smart Growth America.