Water quality data on NOSR 1 are available for surface water, springs, and groundwater. Surface water samples have been obtained and analyzed by the USGS at the surface water gages since Water Year 1977. The surface water quality analyses contained in this section have been compiled and published in Water Resources Data for Colorado, Volume 2, Water Years 1977, 1978, 1979, and 1980. Springs have been sampled for water quality analysis by both DOE/TRW and the USGS. DOE/TRW has sampled 12 springs. Nine of these springs were sampled once. The other three springs were sampled in September 1980, March 1981, and July 1981. These multiple samples from individual springs were analyzed to determine if spring water quality varied at different times of the year. The USGS has sampled eight springs on NOSR 1 as part of a regional study of the drainages of the Roan Creek and the Parachute Creek. Groundwater has been sampled on NOSR 1, beginning during the 1977 resource evaluation drilling program. During the 1977 drilling program, the USGS sampled the groundwater during drilling using air circulation. In 1978, three additional core holes were drilled - primarily for resource evaluation purposes (core holes 18, 19, and 24). Groundwater samples were obtained during limited pump testing on core holes 18 and 24. Beginning in the summer of 1980 and continuing in the summer of 1981, DOE/TRW obtained groundwater samples from individual water-bearing zones during pump testing of most core holes. In addition, in February 1981, DOE/TRW obtained one bailed open-hole sample from each core hole for water quality analysis. The location of all core holes used to obtain groundwater samples are described. 4 figures, tables.