Semi-Continuous Sand Filter (SCSF) supplies a stable and safe drinking water. SCSF is composed of the latest unit process for water treatment. This system has many references with similar function and size. Usually, this system is composed of line mixing, flocculation, lamella settling, SCSF and chlorination. Coagulants like alum is injected to line mixer. Rapid mixing, coagulation and flocculation happen in the line mixer and the following pipe. Primary solid and liquid separation happen through the lamella settler. Lamella package can reduce the footprint and space required for settling. Flocculated materials settle down and clean water flow out through lamella package. The remaining suspension into the filter is detained, as passing the filtering layer. The refined water is collected through underdrain and transferred to the pure water reservoir. Backwashing with air and water are implemented in each sector separated by the inner partition.