Las Gallinas Valley Sanitary District, San Rafael, CA 

BioCNG, A Tetra Tech Company, provided design, grant submittal, and management services for a Biogas Energy Recovery System (BERS) facility at the Las Gallinas Valley Sanitary District (LGVSD) wastewater treatment plant, located in San Rafael, California. Tetra Tech designed the pre-commercial BERS to recover 100 percent of the biogas produced from anaerobic digestion of wastewater sludge and condition it on-site for combined heat and power (CHP) generation and renewable compressed natural gas (CNG) transportation fuel use.

System design includes the integration of a BioCNGTM gas conditioning system, microturbines, hydronic boiler, and renewable natural gas fueling station to achieve 100 percent utilization of the conditioned digester gas, and to generate power for the facility, as well as provide a heating source for the digester sludge. LGVSD will be utilizing the renewable CNG to supplement natural gas for their own CNG vehicle fueling requirements. Tetra Tech also assisted in preparing and successfully receiving several grants through the California Energy Commission and the California Alternative Energy and Advanced Transportation Financing Authority. This included receiving $999,000 in California Energy Commission funding for the project.

Tetra Tech provided design engineering services during construction, which included submittal and request for information (RFI) review, and answering contractors’ questions and providing design changes where needed.