This unit analyses the nature of municipal wastewaters and the issues involved in the management of discharges to sewers and controlled waters, including combined storm overflows. It examines the physical, chemical and biological quality of urban and domestic wastewaters, together with the preliminary, primary, secondary and tertiary/advanced treatment technologies and processes that are used to meet discharge standards and also reviews the measures that are used to monitor and control discharges of industrial effluent to sewer.