The Upper Floridan aquifer is contaminated with saltwater in a 2-square-mile area of downtown Brunswick, Georgia. This contamination has limited development of the groundwater supply in the Glynn County area. Hydrologic, geologic, and water-quality data are needed to effectively manage water resources. Since 1959, the U.S. Geological Survey has conducted a cooperative water program with the City of Brunswick to monitor and assess the effect of groundwater development on saltwater contamination of the Floridan aquifer system. During calendar year 2008, the cooperative water program included continuous water-level recording of 12 wells completed in the Floridan, Brunswick, and surficial aquifer systems; collecting water levels from 21 wells to map the potentiometric surface of the Upper Floridan aquifer during July 2008; and collecting and analyzing water samples from 26 wells to map chloride concentrations in the Upper Floridan aquifer during July 2008. Equipment was installed on 3 wells for real-time water level and specific conductance monitoring. In addition, work was continued to refine an existing groundwater-flow model for evaluation of water-management scenarios.