Regional San and SMUD conducted a Biogas Enhancement pilot test
that evaluated the feasibility of using other waste materials,
such as fats, oils and grease (FOG) and food processing waste
(FPW) such as soda pop waste. Both waste materials were injected
directly into an anaerobic digester to generate additional
biogas. The pilot test assessed what effects the new waste
materials would have on the existing anaerobic digestion process,
including impacts to biogas production, amount of additional
residual biosolids that will be produced and require disposal,
and assessment of waste material handling and storage needs.
The test confirmed that introduction of FOG and other FPWs into
the anaerobic digesters located at SRWTP improved overall biogas
production and would result in the additional production of
electricity from this green energy source.
With the pilot test concluded, Regional San began construction of
the full-scale Biogas Enhancement Facility (BEF) at SRWTP in
February 2012. The facility was completed in early 2013. The
additional biogas captured is used by SMUD to generate renewable
energy at SMUD’s Cosumnes Power Plant located in southern
Sacramento County. The facility also provides another disposal
location option for commercial haulers of FOG and liquid FPW.
This project has numerous operational, financial and community
- Saving local businesses money by providing an advanced, local
receiving station for wastes that can reduce fuel and fleet costs
associated with trucking the waste to distant locations.
- Increasing the production of biogas which will be used to
generate renewable electricity for up to 1,000 homes in the
- Utilizing existing waste processing and power generation
infrastructure to minimize capital costs.
- Eliminating greenhouse gas emissions associated with organic
waste in landfills and its transportation to disposal sites
outside the region.
- Reducing the amount of waste entering the local sewer
Costs and Funding
SMUD and Regional San received approximately $1.45 million in
American Recovery and Reinvestment Act funding from the United
States Department of Energy and $100,000 in matching funds from
the California Energy Commission to help construct the FOG
receiving station. The remainder of the project was funded by
Regional San. The construction cost of the receiving station was
approximately $2.1 million.