The City of Healdsburg, California currently operates two well fields (Fitch and Gauntlet) located along the Russian River. The wells have been categorized by the California Department of Health Services (DHS) as being groundwater sources under the direct influence of surface water due to turbidity increases during the rainy season, when water turbidity levels in the Russian River increase. Membranes were selected as treatment technologies to meet the Surface Water Treatment Rule since they provide a reliable physical barrier against pathogens compared to conventional coagulation/filtration technologies. A pilot study was conducted at the Fitch Well Field between February and May 2002. The study was conducted to identify specific membrane suppliers and gather information that would be used in the future for subsequent purchase and design of a full-scale membrane system. An assessment of iron and manganese removal was also incorporated into the pilot study since the Fitch Well Field periodically have iron and manganese levels in excess of the secondary MCL. Membranes tested include Pall Corporation (Model USV 6203 MF), US Filter/Memcor (Model 3M10V MF), Zenon Environmental Inc (ZeeWeed 1000 -UF), and Aquasource (Model M1A35 UF). Includes 5 references, tables, figures.