Papers and Reports

Dedicated land disposal of lagooned sludge, when used in conjunction with anaerobic digestion, can be an economical and environmentally sound solution to a community’s sludge treatment and disposal needs. This method of sludge treatment and disposal can be designed at very reasonable costs and is a system which minimizes the use of expensive energy and maximizes operational flexibility and reliability. Facultative sludge lagoons provide the much needed break between daily solids production and time-limited land disposal operations. At Sacramento’s Central Plant, these lagoons have been operated successfully with shallow, aerobic, high pH surface layers and deep, anaerobic, solids concentrating bottom layers. The continuing volatile solids digestion and solids concentration in the lagoons serve not only to decrease the frequency of sludge harvesting but also the quantities of sludge that need to be disposed of to land. The exceptionally high sludge application rates that can be achieved with dedicated land disposal, without fear of being limited by regulatory constraints associated with agriculture reuse of sludge, make this disposal method especially attractive.