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Karangpilang II Water Treatment Plant (WTP) is a part of Karangpilang WTP of Surabaya City Water Company, (PDAM Surya Sembada), that serves the water supply for Surabaya City. Karangpilang II WTP has the biggest clean water production capacity in Karangpilang WTP, which is 2500 L/s. Using conventional treatment to remove turbidity, the treatment plant in Karangpilang II WTP consists of pre-sedimentation unit, clearator unit and filter unit. In this study, evaluation of turbidity quality in production water and turbidity removal efficiency were conducted to analyze the Karangpilang II WTP performance in turbidity treatment. The evaluation is conducted using 2016 data, by comparing the turbidity of production water with the Water Quality Standard of PDAM, and by comparing the turbidity of raw water, each treatment units effluents and production water. The evaluation result shows that in the case of Karangpilang II WTP turbidity removal performance, there were some occurrences that the turbidity in production water still not fulfilled the standard quality. The evaluation result also shows that there was a unit in the Karang Pilang II WTP with inadequate performance in turbidity removal, which was the pre‑sedimentation unit. The solution that may be given to solve the problem of turbidity removal in Karangpilang II WTP are: increase the maintenance schedule for pre-sedimentation unit; determine the proper turbidity reference in determination of coagulant dose; optimize the coagulant dose; using produced sludge from water treatment as coagulant aid along with Al2SO4; and using capping material in filter unit.