Water quality analyses of groundwaters at the Hanna, Wyoming, underground coal gasification (UCG) test sites comprise part of a continuing monitoring program to assess the impact of UCG on the environment. Collection and analysis of groundwater samples by DOE and various DOE contractor laboratories were initiated in 1974 and intensified in 1980. Samples from 48 wells were tested for 46 chemical and physical water quality parameters. This report includes data collected through December 1982. The objectives of this report are to make the raw data available and to draw preliminary conclusions on the extent of contamination at the site based on data analysis. Critical analysis of the water quality data is limited by the fact that the Hanna UCG test sites were primarily designed to provide engineering data rather than environmental data. However, the environmental monitoring program has been able to provide some conclusions about water quality based on the presence and levels of the two major UCG water-borne wastes, which are pyrolysis products and leachates. Pyrolysis products and leachates were detected in wells completed in both the coal and overburden aquifers. The impact was greatest in the gasification cavities, with some evidence of contamination in noncavity wells proximate to the burn areas. Contamination detected in both the cavity and noncavity wells was greater for those wells completed in the coal aquifer. 17 figs., 6 tabs.