High frequency estimated chloride (Cl) and observed specific conductance (SC) data sets, along with response variables derived from those data sets, were used in an analysis to quantify the extent to which deicer applications in winter affect water quality in 93 U.S. Geological Survey water quality monitoring stations across the eastern United States. The analysis was documented in the following publication: Moore, J., R. Fanelli, and A. Sekellick. In review. High-frequency data reveal deicing salts drive elevated conductivity and chloride along with pervasive and frequent exceedances of the EPA aquatic life criteria for chloride in urban streams. Submitted to Environmental Science and Technology. This data release contains five child items: 1) Input datasets of discrete specific conductance (SC) and chloride (Cl) observations used to develop regression models describing the relationship between chloride and SC 2) The predicted chloride concentrations generated by applying the sites-specific and regional regression models to high-frequency SC datasets 3) The regression equations for 56 USGS water quality monitoring stations across the eastern Unite States, as well as three regions 4) Response variables describing temporal patterns in SC and chloride, calculated by using the estimated high-frequency chloride time series datasets and high-frequency SC datasets 5) Watershed characteristics describing the land use, geology, climate, and deicer application rates for the 93 watersheds included in the Moore et. al (in review) study.