Tetra Tech and CGRS Announce Partnership in City of Boulder


BOULDER, CO – Tetra Tech and CGRS, Inc. are partnering on the City of Boulder’s innovative Biogas Use Enhancement Project, a biogas-to-renewable natural gas (RNG) conditioning system under construction at the city’s Water Resource Recovery Facility (WRRF). Biogas produced from wastewater digesters will be converted into renewable natural gas (RNG) for vehicle fuel, delivered to community partners after injection into the Public Service Company of Colorado (PSCo) pipeline. Construction began in January and is scheduled for completion this summer.

Tetra Tech, a leading provider of high-end consulting and engineering services, is providing engineering, procurement and construction (EPC) services to the City of Boulder. Fort Collins, Colorado-based CGRS is the general contractor and design-build partner, overseeing and performing the majority of on-site construction work.

The project will replace the WRRF’s cogeneration system, which is at the end of its useful service life, with a new digester gas upgrading system. Western Disposal has agreed to purchase the city’s RNG to fuel a portion of its vehicle fleet, approximately 31 trucks. The project will also enable the City to take advantage of revenues available to renewable fuel producers under the EPA’s Renewable Fuel Standard, driving a projected return on investment in the next 10 to 15 years.

Call a CGRS Expert:

Cory Kahler
Operations Manager
Mobile: 720.537.9387

“The Biogas Use Enhancement Project is the next logical step toward making the WRRF more environmentally sustainable as well as economically viable,” says Chris Douville, Wastewater Treatment Manager for the City of Boulder. “We’re pleased to realize the positive impact on the community’s climate goals through production and use of RNG as vehicle fuel, as well as the city’s financial ability to support other renewable energy and sustainability projects in the future through sale of RNG.”

The work includes installing a BioCNG™ gas conditioning system, demolishing the existing cogeneration engines and heat recovery systems, installing one new boiler, and upgrading the hydronic system used to heat the digesters and other buildings.

“CGRS is excited to lend our design-build expertise in renewable natural gas facilities to Tetra Tech and the City of Boulder on this innovative project,” says CGRS Project Manager Greg Steed, PE. “Not only will this project reduce another a Front Range community’s environmental footprint, it will also enhance services to Boulder residents, and we are honored to be a part of it.”

Boulder RNG Project - Environmental Consulting Company - CGRS
Boulder RNG Project - Environmental Consulting Company - CGRS
Boulder RNG Project - Environmental Consulting Company - CGRS

About CGRS, Inc.

CGRS designs and builds biogas facilities for the private and public sectors throughout the Rocky Mountain region and beyond. It most recently completed a design-build project for the City of Longmont that transforms sewage gas from the Wastewater Treatment Plant into sustainable fuel for its waste collection trucks. It was the first project of its kind on the Front Range and one of only a handful of similar ventures in the U.S. CGRS is Solutions Delivered.

About Tetra Tech

Tetra Tech is a leading provider of high-end consulting and engineering services for projects worldwide. With 20,000 associates working together, Tetra Tech provides clear solutions to complex problems in water, environment, infrastructure, resource management, energy, and international development. We are Leading with Science® to provide sustainable and resilient solutions for our clients.

For more information about the City of Boulder’s Biogas Use Enhancement Project, contact: 


Samantha Gavin
Communication Specialist for Public Works and Planning
720.564.2362 (office)
720.667.9480 (cell)

CGRS - as an Environmental Consulting Company

Kelly Serrano*
Marketing Coordinator
800.288.2657 (office)
970.342.0146 (cell)

Kay Turgeson
Marketing, Sales & Business Manager
608.279.2966 (Cell)
630.410.7202 (Business)

* Contact Kelly for additional photos and give credit for all photos to CGRS, Inc.