A school district based in O'Fallon, Missouri, has experienced significant cost savings after adding a total of 70 propane school buses to its fleet.

As School Bus Fleetpreviously reported, in 2013, Fort Zumwalt School District R-II purchased a total of eight Blue Bird Vision propane school buses in an effort to cut costs and reduce emissions.

Jeff Orr, the district’s chief financial officer, told SBF at the time that the addition of the propane buses, which were the first for the district and the state, allowed Fort Zumwalt to save around 18.9 cents per mile due to reduced fuel costs. He also said that the district anticipated a savings of approximately $18,000 for the first year in operating the propane buses.

Now, nearly eight years and 62 more propane buses later, Fort Zumwalt School District R-II is experiencing a fuel savings of about $70,000 per year, according to a case study from the Missouri Propane Education and Research Council (MOPERC).

Jeff Schwepker, the district's director of transportation, said in the study that the district currently pays $1.36 per gallon for propane compared to $2.32 per gallon for diesel.

Using approximately 70,000 gallons of propane per year, Fort Zumwalt fuels its buses with two onsite fueling stations — one equipped with two 3,000-gallon propane tanks, and the other with a 9,000-gallon propane tank, according to MOPERC. The tanks are reportedly refilled by propane provider Ferrellgas.

“The fueling process is quick and easy and is similar to diesel,” Schwepker added in the study.

He also said that the propane buses perform much like diesel buses, with the exception of quieter, cleaner operations and fewer maintenance costs.

As Fort Zumwalt School District R-II looks to add more propane buses to its fleet, Schwepker said he will continue replacing the district's aging 77- and 53-passenger buses.

The district currently transports 12,000 students to 26 schools every day using 174 school buses, and 40% of those buses are propane, according to MOPERC.