The City of Longmont, Colo., has begun construction on a biogas treatment and renewable natural gas (RNG) fueling station project in partnership with Fort Collins, Colo.-based CGRS Inc.
Once complete later this year, the project will transform sewage gas into sustainable fuel for the city’s trash trucks. Longmont will replace 11 of its 16 diesel trash trucks with trucks capable of using RNG fuel. The city estimates it will offset over 90,000 gallons of diesel fuel annually, reducing greenhouse-gas emissions by about 1,000 metric tons of carbon dioxide equivalents per year, as well as saving $270,000 per year (assuming diesel fuel is $3/gallon). The remaining five diesel trucks will be replaced in 2021.
The Colorado Department of Local Affairs awarded the city a $1 million grant to offset a portion of the capital costs required to build the project. In addition, Longmont is also able to take advantage of credits from the U.S. Environmental Protection Agency’s Renewable Fuel Standard program. The Colorado Regional Air Quality Council also awarded the city a grant for $35,000 per truck ($385,000 total) to cover 80% of the difference in cost between an RNG truck and a diesel truck.
CGRS’ compressed natural gas construction services department is building the entire project, which consists of two sites. The first is the city’s current wastewater plant, for which CGRS will provide interconnections and gas treatment equipment to clean the sewage gas. The RNG pipeline will run from the wastewater plant, located at 501 1st Ave., to a second site on the northwest corner of the property off of South Martin St. CGRS will build a 17,000-square-foot building with four bays for indoor fueling of the city’s trash fleet and a two-story, 5,000-square-foot administration building.
“This project is directly in line with the city’s sustainability plan,” says John Gage, civil engineer and project manager for the City of Longmont. “In 2018, Longmont completed the city’s first greenhouse-gas inventory to develop a baseline of greenhouse-gas emissions. Based on the results, we prioritized a number of strategies to reduce citywide greenhouse-gas emissions, such as the transition to RNG trash trucks.”
The city has also contracted with Carollo Engineers to design and construct the biogas treatment system. CGRS is serving as project manager and construction contractor for the entire project, as well as designing the new fueling station.