Several objectives have been set forth to test the feasibility of utilizing biological pretreatment as a membrane pretreatment step: determine the ability of the laboratory scale biological filters to reliably produce effluent water with reduced concentrations of organic carbon; quantify the increase or decrease in removal efficiencies if the water is prechlorinated; test a variety of downstream filters to remove biomass produced in the biological filters; and, develop and test "membrane assays" that will assess the relative efficacy of one design over another for reducing fouling on membranes. These assays will serve as a screening tool for the experimental phase of the research. An experimental system was designed to examine biological pretreatment in the laboratory and to examine the influence of chlorination on the dissolved organic carbon (DOC), compare packing material, and examine the postfiltration step. The use of different filter media and consideration of an oxidation step were included as important parts of the design. Also important was the postfiltration step. Empty bed contact time was chosen at 20 minutes to minimize the impact of that variable. Biofouling assays are implemented on all treatments including internal controls. Includes 20 references.