City of Longmont Wins WEF Project Excellence Award for Biogas-to-Vehicle-Fuel Project in Colorado

The Project Excellence Award recognizes the project for its ability to address common and complex issues within the water sector and deliver original, sustainable, and valued solutions that not only meet the owner agency’s expectations in terms of quality, cost, and schedule but also improve the well-being of local communities.

Biogas is an energy-rich by-product of a wastewater treatment plant’s anaerobic digestion process that, without proper infrastructure or a reuse plan that captures its benefits, utilities often waste. However, a proper treatment system can covert this valuable resource into RNG, which can then be compressed into compressed natural gas (CNG) that serves as a clean, local, and reliable source of low-cost renewable fuel.

To achieve this, the Biogas Treatment and RNG Fueling Station project is comprised of a new biogas-upgrading system at the WWTP, a new indoor vehicle-fueling station and administration building, and a pipeline to transport the RNG between the WWTP and fueling site. The produced RNG currently fuels the City’s Waste Services fleet whose diesel trucks were recently replaced with 11 quiet, odorless vehicles that run on CNG.

The project and the fleet replacement supported each department and division’s needs, allowing for robust collaboration that continues to benefit individual operations, the City, and its communities as a whole.

“To incorporate both RNG and CNG systems into one successful project, it was critical that we understood both the WWTP and Waste Services fleet’s operations as well as the City’s end goals,” said Cory Kahler, CGRS’s water and wastewater operations manager and CNG expert. “The lessons we learned are ones we will draw on for all future RNG/CNG projects.”

Since the biogas-upgrading system and vehicle-fueling station came online in March 2020, the City has offset nearly 100,000 gallons of diesel fuel per year, not only saving up to $300,000 annually in fuel costs but also reducing greenhouse gas emissions by roughly 1,000 metric tons of carbon dioxide equivalents per year—the equivalent of removing 200 cars from the road. And, because RNG can also be sold as valuable renewable identification numbers (RINs) or “credits” through the U.S. Environmental Protection Agency’s Renewable Fuel Standard program, the City anticipates earning a revenue of close to $400,000 by the end of 2021.