The drinking water plant of Kluizen treats surface water with high levels of organics and alkalinity. In the original plant, built in 1974, sludge blanket clarification followed by filtration was applied for floc removal. In 2008, the plant was extended with two additional treatment lines where flotation is used instead of sludge blanket clarification. Flotation-filtration proved to be very reliable. By 2018, an additional increase of the production capacity is planned. Therefore, a comparison has been made between flotation–filtration and ultrafiltration, both with respect to effluent quality and costs. Based on this comparison, flotation was selected to be the optimal floc removal process for the future treatment lines. Ongoing research focuses on the possibility of applying ion exchange as a pretreatment prior to coagulation–filtration, as this was found to have benefits with respect to both operational costs and natural organic matter (NOM) removal.