A groundwater recharge demonstration project sponsored by the US Bureau of Reclamation is being conducted by the Salt Lake County Water Conservancy District in Utah. Treated surface water will be injected in winter into the aquifer through injection wells and recovered through separate wells during the peak summer months. The conveyance capacity of the project will be 1,000 gpm (5.5 mil L/d). The water will have to meet drinking water criteria before it is injected. To satisfy this requirement, a pilot study, described in this article, was performed from February to June 1990 to determine the best technology for treating the water before injection. Results of jar tests indicated that optimum treatment can be achieved using alum, polymer, and potassium permanganate and that a dual-media filter outperformed a liquid filter bag. Disinfection with ultraviolet light was selected to be the last treatment prior to injection. On the basis of pilot-scale testing, a demonstration treatment plant was designed and built. The actual recharge demonstration project will begin in the winter of 199192. At the end of this three-year project, recommendations for a fullscale project will be made. Includes 7 references, tables, figures.