Dublin San Ramon Awards Contract for New Digester and Grease Receiving Facility

Three anaerobic digesters at the DSRSD wastewater treatment plant break down solids and produce biogas to generate electricity and heat. DSRSD will begin building a fourth digester in August to keep up with growth and provide redundant capacity for maintenance.

On June 20th the Dublin-San Ramon Sanitary District Board of Directors awarded a $7.8 million contract to GSE Construction Company (Livermore, CA) to build a fourth anaerobic digester and a receiving station for fats, oils, and grease at the DSRSD Regional Wastewater Treatment Facility in Pleasanton. In addition, the DSRSD Board authorized $473,000 for engineering services during construction by Carollo Engineers (Walnut Creek, CA) and $496,000 for construction management by The Covello Group (Walnut Creek, CA).

Anaerobic digesters work like mechanical stomachs, providing an ideal environment for bacteria to decompose the organic solids in wastewater and destroy pathogens. The process produces biogas, a renewable fuel DSRSD captures and uses to generate electricity and heat for treatment plant operations. DSRSD needs an additional digester to handle growth in its customer base and provide enough redundant capacity to take a digester offline for cleaning and maintenance.

The receiving station will provide a local, environmentally responsible disposal option for companies that pick up grease trap waste from restaurants. The concentrated grease helps digester bacteria break down solids more efficiently and produce more biogas. The receiving station also will generate tipping fee revenue, which DSRSD will use to offset operating costs.

“We had designed 90 percent of this project by 2010 to accommodate forecasted growth. Then wastewater flows stabilized during the recession and drought and we put the project on the shelf. After updating our master plan for wastewater treatment facilities this year, we determined that we should move forward now to maintain efficient operations for our customers and the community,” says DSRSD Engineering Services Manager Judy Zavadil.

Construction starts in August and will take a year to complete. The project’s total cost, including design, is budgeted at $13.1 million. Fees collected from developers for infrastructure expansion are funding about 90 percent of the cost.


Founded in 1953, DSRSD serves 173,000 people, providing potable and recycled water service to Dublin and the Dougherty Valley area of San Ramon, wastewater collection and treatment to Dublin and south San Ramon, and wastewater treatment to Pleasanton (by contract). DSRSD also operates the Jeffrey G. Hansen Water Recycling Plant and backbone recycled water distribution system on behalf of the San Ramon Valley Recycled Water Program, a partnership among DSRSD, East Bay Municipal Utility District, and Pleasanton. The DSRSD office is located at 7051 Dublin Boulevard, Dublin, CA, 94568. For more information visit www.dsrsd.com.

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