The Indiana-American Water Company is faced with two challenges: to expand the treatment capacity of its Kokomo District facility to meet projected demand, and to economically remove iron, manganese and arsenic from its well water supply. Conventional clarification, oxidation-filtration and contact adsorption clarification-mixed media filtration were compared to evaluate their ability to provide an acceptable finished water quality, as well as to determine what pretreatment would be required for optimum performance. The results of the pilot study compared favorably with those of the bench-scale clarification studies in terms of iron, manganese and arsenic removal and demonstrated that the contact adsorption clarifier - mixed media process could achieve the desired water quality at higher clarification rates than a conventionally-designed plant.