International
City in Colorado develops innovative biogas plant & CNG station project
Steel rising on a site at the northwest corner of the city of Longmont’s Wastewater Treatment Plant (WWTP) is a sign of the future. The steel provides the frame for an approximately 23,000-square-foot building for Longmont’s Biogas Treatment and Renewable Natural Gas Fueling Station Project, which will transform byproducts from the WWTP into renewable fuel for city trash trucks.
The front or west-facing side of the building will house approximately 10,000 square feet of administrative offices on two stories; the remaining 13,000 square feet on the east side will serve as the fueling station. General contractor CGRS, Inc., of Fort Collins, brought in Maverick Steel, Inc. of Byers, to begin erecting the steel in late July. The entire process should take four to six weeks.
CGRS already set the CNG equipment into place on the site, built 10 CNG fueling islands, poured concrete for the building’s floor and completed the underground plumbing. The CNG equipment will compress the biomethane produced at the WWTP up to 4,500 psi (pounds per square inch). For comparison, the standard dive pressure in a SCUBA tank is 3,000 psi. That compressed biomethane will then become a useable vehicle fuel to power the city’s trash trucks.
Once the project is completed, the city will replace 11 of its diesel trash trucks with those that can run on biomethane, eventually replacing its entire fleet of 20 trash trucks. It is estimated that the city will offset over 100,000 gallons of diesel fuel annually, reducing greenhouse gas emissions by about 1,000 metric tons of carbon dioxide equivalents per year — the equivalent of removing 200 cars from the road.
The total design and construction cost for the equipment to treat, compress and dispense biomethane for vehicle fuel is $5.2 million. The total cost for the site work and the new building–including administrative office area and truck storage/fueling area–is $3.1 million. The State of Colorado Department of Local Affairs awarded Longmont a $1 million grant for biomethane equipment. The Regional Air Quality Council awarded a $385,000 grant toward the purchase of the new trash trucks.
In addition, by building the station, the city will be able to take advantage of valuable credits from the United States Environmental Protection Agency’s Renewable Fuel Standard program. The annual benefit associated with these credits is an estimated $100,000-$200,000 per year. Savings from no longer using diesel fuel to power the trucks is anticipated at $100,000-$200,000 annually.