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Technical Description Characteristics of the activated sludge play an important part in this settling time. A good food source, along with adequate oxygen, produces a fluffy bacteria. It is these light, fluffy bacteria that produce the floccing action in the clarifier. Because both the food source and oxygen are depleted in the clarifier, the sludge loses its fluffiness and is pulled down by gravity, leaving a visible sepa- ration between the supernatant, or clarified, liquid and the sludge. If the SSV-60 test indicates sludge-wasting is required, the following procedure will be used: After the supernatant has been transferred from the clarifier, 5% percent of the remaining sludge, which has no odor, will be returned to the aerobic sludge digestion system for further stabilization under aerobic conditions. EXAMPLE: A 30,000 gpd Bio-Pure system as proposed for the Castillo Estates Project will batch 6,494 gallons of mixed liquor to the clarifier from the aeration chamber. After a 60-minute settling period in the clarifier, 2,164 gallons of the batch in the clarifier are removed as super- natant and the remaining 4,329 gallons are classified as sludge. A minimum of five percent of the sludge, or 217 gallons, will be wasted to the aerobic digester. This wasting procedure follows recommendations described in Operation of Waste Treatment Plants published by California State University, Sacramento, Department of Civil Engineering, in cooperation with the California Water Pollution Control Association for the Federal Environ- mental Protection Agency, Office of Water Program Operations. Bio-Pure systems have a field history of extremely low sludge generation. The Bio-Pure process, when compared to a flowthrough system, will produce a much higher quality effluent with far less sludge production. The Bio-Pure process concept is covered, in part, in federal regulatory agency guidelines as de- tailed in Recommended Design Criteria for Activated Sludge Processes. The Bio-Pure batch-reactor process is a modified version of the activated-sludge process. Known as a complete-mix system, it treats wastewater in batches, sequentially controlled by a microproc- essor system. This unique feature makes possible effective, quality treatment of sewage, regard- less of input surge-flow patterns. The principal steps are: Raw sewage/wastewater enters the aeration tank, where previously developed biological floc par- ticles are brought into contact with the incoming, suspended organic matter. The organic matter is a carbon and energy source for cell growth and is converted into cell tissue and/or converted to carbon dioxide (CO2). The digestion process in the aeration chamber is initiated by the introduction of air into the incom- ing wastewater. The soluble material, oxidized material, settleable and suspended solids form the mixed liquor. This biological mass is referred to as the Mixed Liquor Suspended Solids, (MLSS), or Mixed Liquor Volatile Suspended Solids (MLVSS), and consists mainly of microorganisms, inert suspended matter, and nonbiodegradable suspended matter. After a preset period, the mixed liquor is transferred to the clarifier tank for separation of sus- pended solids from the treated wastewater. The biological solids are then returned to the aeration tank to maintain a concentrated population of microorganisms to treat new, incoming waste.