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Nucla Mine during the 1991 water year was conducted in accordance with the approved • hydrologic monitoring program for the Nucla Mine during temporary cessation (see Appendix 15-4, Tab 15, Nucla PAP). Table 5 presents a summary of cell locations, completion information, and monitoring frequencies during temporary cessation for ell monitoring wells established at the Nucla Nine. Na[er Level data collected at monitoring wells at the Nucla Mine during the 1991 water year are presented in Appendix D, and ground water quality data far samples collected a[ those wells are presented in Appendix E. Table b presents the list of parameters used to analyze water quality samples obtained at monitoring wells at the Nucla Mine during the 1991 water year. This parameter list will be used for analyzing ground water quality samples collected during the 1992 water year. Monitoring Well Nater Levels. Water level data for Nucla Mine monitoring cells are given in Appendix D. In summary, na n-irrigation water levels were uniformly lower than during the corresponding period in 1990, except for Well GW-N11, which appears to be seasonally invariant. Irrigation season water levels, however, were generally higher than in previous years, particularly in those Nells monitored for water quality. GW-N27 attained • a record high Nater level of 44.27 feet in September, 1991. Water levels in Wells GW-N8, GW-N3, and GN-N27 have continued to rise since mining activity ceased in 1989 with GW-NB experiencing [he greatest rise. Wells GW-N10, N24, N26, and N28 were dry throughout 1991. Ground Water Ouality. Water quality data for Che Nucla Mine monitoring Nells are given in Appendix E. Laboratory chemical analyses far ground water sites monitored during the 1991 Nater year Nere compared with those obtained during the 1990 water year, and with previous historic data (1980-1989). Table 7 gives a listing of those chemical parameters whose historic ranges Nere exceeded during 1991. In general, the higher than normal water levels in all wells monitored for Mater quality during September, 1991 appear to be cause-related to elevated levels of alkalinity, bicarbonate, pH, and sodium, and to corresponding decreases in calcium, magnesium, and sulfate levels. The high dissolved lead level at GW-N4R (110 ug/L) is probably an analytical error, as it exceeds the historic maximum concentration by 90 ug/l. Spoil Spring k1 Was sampled for Water quality in April and September of 1991. eater quality data are presented in Appendix C, and Table 8 gives a listing of those chemical 11