Specifications include, but are not limited to: Regional San provides wastewater treatment to approximately 1.6 million customers in the Sacramento area and surrounding cities. Regional San land applies biosolids onsite that are collected during the treatment process. The liquid stream portion of the treatment process includes preliminary, primary, secondary and tertiary treatment processes. The solids stream processing includes grit, screenings, scum treatment, sludge handling, sludge thickening, anaerobic digestion, dewatering, storage and disposal that includes solids storage basins and lined dedicated on-site land disposal (L-DLD). During the solids process, the solids are sent to the digesters for anaerobic digestion. After digestion, biosolids are pumped from the digesters to the solids storage basins (ponds). The treatment plant has a total of 20 ponds. The ponds have a combined total surface area of approximately 125 acres. Digested sludge is stabilized in the ponds for a period of three to five years before it is removed. The supernatant of the ponds is sent to the headworks of the plant. During the winter, the supernatant will send approximately 4 MGD of 1% solids to the headworks. During rain events, a rental belt press will be set up for approximately 5 months to remove a portion of the return load to reduce the impact to the plant. The solids removed from the belt press need to be hauled away and properly disposed offsite by the contractor.
