The City of Sherman, Texas, currently operates a 10-million gallon per day (mgd) water treatment plant (WTP) to treat brackish water from Lake Texoma. The plant uses conventional treatment (flocculation/sedimentation/filtration) followed by electrodialysis reversal (EDR) to remove dissolved solids. As a result of upcoming regulations and growing water demands, the City of Sherman is expanding its Lake Texoma Surface WTP by 5 mgd of finished water capacity. Microfiltration/ultrafiltration (MF/UF) followed by reverse osmosis (RO) demineralization was selected as the best apparent technology to meet the City's operational and water quality goals. Treatment challenges include salinity reduction, turbidity control, total organic carbon (TOC) reduction, elimination of objectionable tastes and odors, and pathogen removal and/or inactivation from the surface water supply sources. Furthermore, the membrane-treated product water will be blended and must be compatible with water from the existing supply and treatment facilities. A pilot study was conducted to evaluate the ability of the planned treatment to meet the City's water quality objectives. As mentioned, planned treatment includes dual-membrane processes, MF/UF for suspended solids and pathogen removal, followed by RO for dissolved solids and TOC reduction. MF/UF pilots from three vendors (Ionics Norit X-flow, Pall Microza, and Zenon ZeeWeed) were followed by two Osmonics RO pilot units. The MF/UF vendors were required to recycle their backwash to achieve an overall system recovery of 99 percent. The product water from the MF/UF units was combined and fed to the two separate RO units so that the performance of membranes with varying characteristics could be compared. A scale inhibitor was used in both RO units. RO performance was compared to manufacturer's projections. Includes tables.