South San Francisco, CA April 22, 2015 Submitted by Leslie Arroyo City of South San Francisco
As the City of South San Francisco recognizes the 45th Anniversary of Earth Day, it’s also celebrating the South San Francisco Scavenger Company (SSFSC), which has built a state-of-the-art anaerobic digester that converts food scraps, yard waste and food-soiled paper into fuel for trucks and compost.
“SSFSC has come up with an innovative solution that is compact, scalable and appropriate for urban environments,” says Jim Steele, Assistant City Manager and Chief Sustainability Officer. “They have also come up with a model that other waste haulers can look into as a way to reduce greenhouse gas emissions.”
SSFSC was faced with limited options to expand the footprint of its facilities and at the same time, the idea of trucking the food scraps and yard waste to an open-air composting facility several hundred miles away would be expensive, burn a lot of fossil fuels and would not optimize its goal of reducing its carbon footprint.
Working with the City of South San Francisco, Assemblymember Kevin Mullin, Senator Jerry Hill and community partners, SSFSC applied for a grant from the California Energy Commission. They were successful in obtaining the grant and SSFSC designed and built a cutting-edge organic waste digesting facility that uses dry anaerobic digestion technology to generate clean-burning compressed natural gas (CNG) that is power the company’s collection fleet.
The digester is set to process 11,200 tons of material per year, including food scraps, yard waste and food-soiled paper collected from businesses in the company’s service area. The process produces approximately 500 diesel gallon equivalent (DGE) per day of biogenic CNG. SSFSC currently has a fleet of 20 trucks that use this methane that is produced at the plant and has plans to expand its entire fleet to CNG.
And in the spirit of true conservation, the digestion process also produces gases that are not appropriate for fueling trucks, but appropriate for other things. These gases are separated from the bio-methane and are used to fuel a boiler system which provides heat to the system. The organic residue that remains after the anaerobic digestion process is a nutrient-rich product which is then shipped to a composting facility where it is matured into certified organic compost.
“We’re excited about the new digester because it allows us to turn compostable food scraps into fuel for the very trucks that collect those materials… it’s a truly closed loop system,” says Doug Button, president of South San Francisco Scavenger Company. “Plus, the process keeps organic waste out of the landfill and cuts greenhouse gas emissions – benefiting the communities we serve, the environment and our company.”
South San Francisco Scavenger Company (SSFSC) and Blue Line Transfer,Inc. are family-owned companies that have been providing solid waste and recycling services to our local communities since 1914. We strive to provide quality service to our customers, minimize the negative impacts of our collection and processing operations and maintain a safe work environment for our employees. We proudly serve businesses and residents in South San Francisco, Millbrae, Brisbane and San Francisco International Airport.