The activated sludge process is the most versatile, commonly used wastewater treatment system in North America; however, many activated sludge processes frequently experience operational problems related to poor compaction or settleability of secondary solids and loss of secondary solids from the clarifier. Eschewing the technical jargon and copious chemical equations found in the majority of wastewater studies, Settleability Problems and Loss of Solids in the Activated Sludge Process speaks directly to plant operators, showing them how to identify and solve common problems and achieve maximum efficiency.