In Dhaka city, the sewage system was first established in 1923. During the period 1923 to 1947 Dhaka was very small district town. The sewerage master plan was formulated in 1950's to cope with the population growth in Dhaka City. Dhaka WASA was established in 1963 as implementing agency for water supply and sewage disposal. Then Dhaka WASA has started implementing for water supply and sewage disposal. Then Dhaka WASA has started extension of its sewerage network day by day and established a lagoon which consists of three stabilization ponds for treatment of sewage of Dhaka city at Pagla in 1977. During 1989 to 1992 the present Pagla Sewage Treatment Plant (PSTP) achieved present status by the technical and financial support of Japanese Government and Government of Bangladesh.