Michelson Water Recycling Plant Biosolids Lift Station and Sewer Pipeline Project

The project involves upsizing an existing segment of IRWD’s sewer pipeline, installing new sewer laterals, retrofitting IRWD’s existing Stormwater Pump Station 3, upgrading IRWD’s existing Biosolids Lift Station, and completing site improvements for Stormwater Pump Station 3. All work would be conducted entirely within the boundaries of IRWD’s Michelson Water Recycling Plant (MWRP). The purpose of the project is to separate waste flows produced by the Biosolids and Energy Recovery Facility from stormwater flows to allow stormwater flows to continue being pumped to Pond C of the San Joaquin Marsh. The waste flows would continue to be pumped to MWRP’s primary treatment. The combined volume of stormwater and waste flows proceeding from the Biosolids and Energy Recovery Facility would not be increased as part of the project; rather, existing waste flows would be re-routed so they can undergo appropriate treatment. No expansion of the existing or former use of the Biosolids and Energy Recovery Facility is proposed, and the MWRP would continue to have the same treatment capacity upon project completion. Sewer Pipelines and Laterals: An approximately 600-foot segment of an existing 8-inch sewer pipeline would be removed and replaced with a new 16-inch sewer pipeline, and an approximately 260-linear-foot segment of existing 6-inch sewer pipeline would be removed and replaced with a new 12-inch sewer pipeline. The new sewer pipeline would connect to existing sewer laterals that convey waste flows from the solids handling building, microturbine area, dewatering feed pump station, fats/oils/grease receiving station, and digester control building. In addition, a new 6-inch sewer lateral would be installed to convey waste flows from the odor control system (approximately 80 linear feet) to the new sewer pipeline. Portions of the existing sidewalk, curb, and gutter would be removed and replaced along the pipeline alignments. During construction activities, wastewater flows would be temporarily conveyed from upstream sewer cleanouts to the storm drain lateral or temporary storage tank. Stormwater Pump Station 3: A portion of Stormwater Pump Station 3 would be modified to bifurcate the existing wet well, isolating the nuisance (sewer) wet well. During construction activities, stormwater flows would be temporarily bypassed to MWRP’s primary treatment. Work would occur during the dry season to minimize the need for bypassing. Biosolids Lift Station: The existing nuisance pumps, piping, instruments, and controls in the Biosolids Lift Station would be replaced and upgraded. A new aluminum cover would be installed over the nuisance (sewer) wet well, and site improvements would be completed around the Biosolids Lift Station and Stormwater Pump Station 3. During construction activities, stormwater flows would be temporarily bypassed to MWRP’s primary treatment. Work would occur during the dry season to minimize the need for bypassing.