ABSTRACT
S UWACE water influent streams include solids, which must be removed and then somehow disposed. Two principle types of sludge result from water treatment: coagulation sludge and softening sludge. After large solids are separated from the raw water by screening, suspended solids and particulate matter remain in the influent until they are removed by coagulation and flocculation. More solids wastes are formed with water softening treatment. Other sludge sources in water treatment include grit from presedimentation and solids from filter backwash, from iron and magnesium removal, and from slow sand and diatomaceous earth filtration.
