San Mateo WWTP Immediate Action Projects

March 2, 2021 The second phase of work on the Immediate Action Projects related to the Clean Water Program’s wastewater treatment plant upgrades is beginning. A $6.3 million contract for the second phase of the Immediate Action Project, or IAP2, was awarded to Myers & Sons Construction LLC on January 7 upon City Council approval. The IAP2 construction package includes five separate projects that are needed to add backup protection to vulnerable points in the digestion and dewatering and solids handling processes, and to repair effluent piping. Additional overflow and suction piping, and a third foam suppression pump, will be added to the digesters and digester piping. This additional equipment in the digestion process area will provide the backup and flexibility that the system requires. A third centrifuge system will be added to the dewatering process, which will provide adequate backup to the current centrifuge system. One large cake pump, which is located in the solids building and transports cake (i.e., dewatered biosolids) to a storage hopper, will be replaced by two smaller cake pumping systems. This improvement will provide appropriately sized pumps and backup to that system. An additional cake hopper that will store all the dewatered biosolids until they can be hauled away will be added immediately outside the solids building. It will include a slide gate, access walkway, and platform. This additional hopper will provide more onsite storage, time between truck trips to dispose of the cake, and resources for operations to maintain other tanks in the digestion process. Lastly, repairs will be made to underground effluent piping and pipe connections.