The City of Spokane has made significant strides in reducing fuel costs and environmental impact by switching its solid waste collection trucks to compressed natural gas (CNG) and renewable natural gas (RNG). In 2025 alone, this shift saved the city’s ratepayers approximately $1.3 million. By using RNG, which is produced from organic waste sources such as landfills and dairy farms, the city not only cut fuel expenses but also earned renewable fuel credits that further lowered costs to around $760,000.
If Spokane had relied on traditional diesel fuel in 2025, the estimated cost would have been about $2.07 million based on an average diesel price of $3.93 per gallon for the 527,000 gallons needed. With diesel prices rising to $6.36 per gallon in May 2026, potential savings have grown even larger, reaching up to $2.6 million annually compared to diesel.
Natural gas vehicles operate similarly to those running on gasoline or diesel but offer considerable environmental benefits. While CNG typically comes from underground natural gas wells, RNG is captured from above-ground organic sources and cleaned to pipeline quality. This process prevents methane, a potent greenhouse gas, from escaping into the atmosphere and converts it into usable fuel.
Over the past decade, Spokane’s Solid Waste Collections department has gradually transformed its fleet away from diesel trucks to one of the largest municipal RNG fleets in the region. The city recently expanded its CNG fueling station to support up to 100 trucks, positioning itself to run nearly all of its collection vehicles on RNG during normal operations.
This transition has resulted in a 77% reduction in diesel fuel consumption compared to 2015 levels. Alongside cost savings, the RNG fleet contributes to lower greenhouse gas emissions and quieter operations. These benefits align with Spokane’s goals of sustainability while also providing financial protection against volatile fuel prices.
Looking ahead, the expanded fueling infrastructure could enable other city departments to adopt natural gas vehicles, broadening the environmental and economic advantages. Spokane’s experience demonstrates how investing in renewable natural gas can be a smart strategy for cities aiming to reduce emissions and control operating costs in their vehicle fleets.
