The City of Longmont recently announced it will begin construction of a project at its Waste Water Treatment Plant (WWTP) to make fuel from gas produced in the treatment of Longmont’s sewage. The project will convert biogas (generated through anaerobic digestion) into clean renewable natural gas (RNG) that will be used to power the city’s trash trucks. Longmont will be the first city on Colorado’s eastern slope to convert biogas to vehicle fuel.
The project will require new biogas cleaning equipment at the WWTP and fueling infrastructure. To support this effort, the Colorado Department of Local Affairs recently awarded the City with a $1 million grant to offset a portion of the capital costs required. Upon completion of the RNG fueling station in 2019, 11 of the City’s 16 diesel trash trucks will be replaced with trucks capable of using the cleaner-burning. The remaining five diesel trucks will be replaced in 2021. The Colorado Regional Air Quality Council awarded the City with a grant for $35,000 per truck ($385,000 total) to cover 80 percent of the incremental cost.
When the project is complete, it is estimated that the City will be offsetting over 60,000 gallons of fossil fuels annually, reducing greenhouse gases by nearly 800 metric tons of CO2-equivalent per year. The project will also eliminate the variability in fuel costs for trash services and provide a revenue stream to fund future WWTP projects through the sale of federal renewable fuel credits.
The RNG fueling station is an example of the city pursuing an innovative project that provides economic value to the community while also aligning with multiple goals in its Envision Longmont & Sustainability Plans.