First Full-Scale Installation of Primary Filtration for Advanced Primary Treatment to Save Energy and Increase Capacity

Primary Filtration (PF) is an emerging advanced primary treatment technology (APT) that can be used to replace primary clarification at wastewater treatment plants (WWTPs). The use of cloth depth filtration (CDF) with 5 micrometer (μm) nominal pore size media yields high total suspended solids (TSS) and biochemical oxygen demand (BOD) removal efficiencies. Based on several pilot and demonstration projects, PF was found to increase the primary treatment TSS removal efficiency by an additional 30 to 50% over conventional gravity sedimentation. Primary filtration also achieves an overall 40 to 60% BOD reduction depending on the influent TSS and BOD relationship. PF can produce significant energy and capital cost savings via carbon diversion due to higher treatment efficiencies when compared to conventional primary treatment. Construction of the first full-scale PF installation was completed in June 2017 at Linda County Water District WWTP (Olivehurst, California). The detailed evaluation of this first full-scale PF installation at Linda WWTP will provide significant information for wider implementation of this promising technology.