This paper presents preliminary results from a recently completed pilot plant study to help demonstrate the feasibility of treating oil field produced water to present and anticipated California potable and reclaimed water quality standards. Key pilot study goals included the removal of total dissolved solids (TDS), total hardness, silica, boron, ammonia and total organic carbon (TOC) by a membrane-based desalting system. Pretreatment included warm precipitative softening, biological treatment, filtration and ion exchange. If this project is successful, it will benefit water utilities located near oil fields that need additional water resources and water users in general that will benefit from having a new, drought resistant water supply.