STARTUP EXPERIENCE OF THE SAN DIEGO METRO BIOSOLIDS CENTER DEWATERING PROCESS

The City of San Diego recently completed the first two years of operation of its new Metro Biosolids Center (MBC) biosolids dewatering process. The MBC, located on a 35-acre site adjacent to the City's municipal landfill is designed to process all of the wastewater solids removed from the City of San Diego and surrounding participating agencies. Processes included on this site include raw solids degritting, centrifuge thickening, thickened solids screening, anaerobic digestion, centrifuge dewatering, pumped dewatered cake conveyance, dewatered biosolids storage, and dewatered biosolids loadout. Startup of the MBC has been done in two phases. Phase one of this project placed the dewatering and loadout facilities into operation. Phase two placed the raw solids thickening and digestion facilities into operation. Moving from a solar drying lagoon and belt press dewatering process to the new high tech 162 dry tons per day high solids centrifuge dewatering process presented many challenges and learning opportunities for the contractors, equipment suppliers, startup team, design engineers and operations staff.