T o fulfill the service target of 64% in 2020, a distribution piping development and water treatment construction are required which is based on the projection population growth and water consumption until 2020. According to Novita Cahya Ningrum's calculation result in the Final Task No.426ffA/IL/ll/2001-2002 entitled "The Development Planning of Clean Water Distribution System :Assignment ofDepok Town until 2020", aproduction capacity of IPA Legong Oepok of 1300 Usecond is required, which will be constructed in two phases,, in 2010 and 2020 each 650 L/second after multiplied by water consumption factor at the drinking water treatment installation. Before the planning is started, the steps are required such: pre-design (site survey, basic water observation used, etc}, data gathering, which consists of primary and secondary data, data analysis, dimension calculation of units planned, hydraulic qrofile calculation, and technical designpictures presentation of IPAM. Meanwhile the clean water treatment units that will beconstructed with the design capacity of 650 L/second are two coagulatiorl units of hydraulic jump type, two flocculation units of horizontal baftle channel type of hexagonaltipe, four sediment units of rectangular type with plate settler, nine filtration units of fast sand filter of dual media typ_e. T6e disinfection process is conducted at the aftluent channel from the filtration unit. The PAC coagulants used per day are 2247 kgtday, withmean PAC dosages of 40 ppm. Meanwhile the disinfectant requirement for the same production capacity is 44,88 kg/day with the average dosage of chloral 0,8 PP.m