This study includes treatment of Domestic sewage water & along with the study of physico-chemical parameter essential for the proper working of a STP. The ultimate goal of waste water management is protection of the environment in a manner commensurate with public health & socio-economic concerns. The STP at Keshopur has a capacity of 72 MGD. & Pappankalan plant capacity is of 20 MGD. The core treatment process used in the treatment of waste water is Activated Sludge process. The activated sludge is a type of waste water treatment process in which organic matter is decomposed with the help of bacteria. STP builds in the last decade use the gas. Generate from sludge digestion for electricity generation. The power generated can be used to run the plant. The gas can be converted into CNG. Sludge after drying can be used as manure. It can be supplied to framers, nursery & horticulture. But sludge drying is a time taking process. We need as such technology that could reduce the time efficacy for the better oxidation of organic matter. The waste water obtained from our daily purposes & from industries must be treated in treatment system in order to reduce pollution.