Groundwater supplies in certain areas of western Nevada are near activegeothermal zones, which can adversely affect water quality. The Indian HillsGeneral Improvement District (IHGID) has a well under such influence. The IHGIDserves approximately 4,000 people in the region of northwestern Nevada just southof Carson City. In response to sulfurous taste and odor conditions, high color,and fluoride levels above the recommended maximum contaminant level, treatmentprocess improvements were designed based on bench- and pilot-scale testing. Thispaper describes the testing and selection of granular activated carbon for thefull-scale system. System start-up and operation are also addressed.