The recommended design is a combination of screw conveyors and progressive cavity pumps. Screw conveyors will collect the dewatered cake and transport it to two progressive cavity pumps, which will convey the cake to existing storage silos. The new OCSD Plant 1 cake conveyance system will be the largest in the country to use PC pumps to pump high solids concentration (30 percent or higher) dewatered cake.
The Orange County Sanitation District (OCSD) serves approximately 2.5 million people and operates two large wastewater treatment plants (WWTPs) in urban Orange County, California. Reclamation Plant 1 (P-1) is a secondary treatment plant with an ocean discharge and a capacity of 85 million gallons per day (MGD). The current solids processing system at Plant 1 includes thickening of primary sludge in the primary clarifiers, dissolved air flotation thickening of waste activated sludge, anaerobic digestion of combined thickened sludges, and belt filter press (BFP)dewatering. Approximately 240,000 wet tons per year of biosolids are recycled to agricultural
Plant 1 is currently undergoing several upgrades, including a new centrifuge thickening and dewatering facility to increase solids concentration and reduce hauling and biosolids management costs. The facility will be located approximately 200 feet from the existing solids storage and load out facility, which includes four storage silos, and piston pumps that pump dewatered solids (cake) to a load out hopper. Conveyance equipment from the dewatering
centrifuges will classify and collect cake solids on the building’s lower level and transport it to the existing storage silos.