Centralized Anaerobic Biogas Plants
Chino Basin, California
Location: Chino Basin, California
Owner: Inland Empire Utilities Agency (water utility)
Biogas Generation: 210,000 ft3/day
Digester Volume: 1.2 million gallons
Developer: Inland Empire Utilities Agency
Cost: $8.5 million
The Chino Basin project is the first centralized anaerobic digester to be developed in the United States. The project came online in 2002 and incorporates cow manure from six regional farms as well as a small percentage of other organic waste from local food industries.
The project is owned and developed by the Inland Empire Utilities Agency (IEUA), a municipal water district located in west San Bernardino County. IEUA partnered with U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS), Department of Energy (DOE) and the California Energy Commission (CEC), a residuals management company, and farm groups.
The primary motivating force for the project was the environmental benefits that an anaerobic digester would bring. The Chino Basin has 350,000 cows that produce over 1 million tons of manure annually, which causes a significant nutrient and salt impact on the water quality in the area. Farm groups favored a centralized system to involve multiple small and moderate sized farms in watershed protection efforts. A centralized biogas plant was also more preferable than individual farm nutrient management plans.
The project is designed to handle about 225 tons of manure per day from 6,250 dairy cows, plus food waste. The manure is trucked to the facility from farms within a 6 mile radius, by collection trucks owned and operated by the plant operators, with the participating farmers pay a tipping fee.
The biogas resulting from the anaerobic digestion process is used to generate heat and run an off-site 370 kW electricity generator. The system also produces 135 tons per day of organic fertilizer. The electricity generated offsets peak use and is used by the water utility to run a groundwater desalinization plant and wastewater treatment facilities.
The total capital cost of the plant was $8.5 million. It received a $5 million grant from the NRCS for watershed protection. The remainder came from the CEC for the renewable energy component of the plant, with the IEUA investing $1.5 million of its own funds in the facility. The regional urban-based ratepayers and users of IEUA’s urban sewer system are currently paying half of the operation and maintenance costs. The other half come from peak electricity purchase savings and from the tipping fees charged to the farmers.
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