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with the water level averaging 14 feet lower than the historic average during the mid- 1990's. Water depths have fluctuated significantly at this well, as evidenced by the Iowest levels during the 1997 and 1998 water yeazs. Water depths at well 95-1 remained consistent with the historic levels recorded over the last eight water yeazs. Water Temperature Water temperature in the wells fluctuates regularly with the seasons. Water temperatures are generally lowest during the winter months and highest during the summer months, though the temperatures respond to ambient weather conditions during the season. Temperature generally fluctuates most in the shallowest well (17-B) and least in the deepest well (95-1). Temperature ranges for the 2002 water yeaz remained within those observed previously for the wells. PH The pH for all wells changed from slightly basic during the end of water year 1996 to slightly acidic at the beginning of water yeaz 1997. This change was also noted in the springs on-site. During water year 2001, the pH of all three wells rose slightly, with the largest change in well 17-B (6.9-7.5). This water year, pH at wells 17-B and 94-1 started at relatively high levels (7.6 and 8.2, respectively), and then dropped through the water yeaz to levels within the low historic range (very slightly acid). The pH of well 95-1 remained slightly alkaline, near the average value over the period of record. These changes in value may reflect larger anion concentrations in the wells during seasonal periods. Electrical Conductivity (EC) Electrical conductivity (EC) values are highest for well 94-1 (mid-mine), median for well 95-1 (downgradient), and lowest for well 17-B (upgradient). EC levels this water yeaz remained consistent for well 17-B within previously observed ranges from the prior water years. Levels for both well 94-1 and 95-1 were slightly to moderately lower than those of prior years. Total Dissolved Solids (TDS) Total dissolved solids (TDS) levels in all groundwater monitoring wells remained within historic values during this water yeaz. Well 17-B shows the least overall variability for TDS values of the three wells, ranging from 235 to 470 mg/L over the past eight yeazs. Well 94-1 showed the widest range in TDS values from 720 mg/L (W.Y. 1999) to 1490 mg/L (W.Y. 1995). TDS values for well 95-1 were intermediate between wells 17-B and 94-1. Wells 94-1 and 95-I show a slight decrease in TDS concentrations over the past eight water years. Carbon Junction Mine Page 8 Mnual Hydrologic Report Ax Watar Year 2002