Three scroll centrifuges, each with a maximum capacity of 200 gpm, provide consistent sludge dewatering to approximately 18 to 20 percent solids. Currently, the plant dewaters approximately 140,000 gallons of digested sludge per day. One centrifuge operates at approximately 185 gpm for 13 hours per day on a 5-day per week schedule. The other units provides backup capability in the event of breakdown of the operating unit. Each centrifuge requires a major overhaul annually. Major overhauls usually require 3 to 4 weeks to complete.