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Pg The pH for all wells changed from slightly basic during the end of water year 1996 to slightly acidic at the beginning of water year 1997. This change was also noted m 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 well 1?-B attenuated in value from prior years with only 0.1 variation in value between the dry and wet seasons. PH at we1194-1 rebounded from a slightly acidic value (6.9) during the last quarter of the 2002 water yeaz to alkaline this past winter (7.8). 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 aze highest for well 94-1 (mid-mine), median for well 95-1 (downgradient), and lowest for well 17-B (upgradierrt). EC levels this water year remained consistent for well 17-B within previously observed ranges from the prior water yeazs. bevels for both well 94-1 and 95-1 were slightly to moderately lower than those of prior recent water 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 nine years. Well 94-1 showed the widest range in TDS values from 720 mg/L (W.Y. 1999) to 1490 mg/L (W.Y. 1995). Since water year 1998 the TDS concentrations for well 94-1 have been 720-970 mg/L, a significantly narrower range than prior to that time. TDS values for well 95-1 were intermediate between welts 17-$ and 94-I. Wells 94-1 and 95-1 show a slight decrease in TDS concentrations over the past nine water years. Ali the monitoring welts showed some fluctuation in ionic concentrations this water year. The fluctuations were not consistent as far as the constituents that fluctuated or the wells that showed fluctuations. The majority of the fluctuations were within historic ranges observed for the wells over the last nine water yeazs. Notable changes are further described below. Ammonia Ammonia concentrations for wells 17-B and 94-1 remained within historic ranges during the 2003 water year. Well 95-1 exhibited a significant rise in ammonia concentrations during the 2000 water year from 1.50 mg/L in the second calendaz quarter of 2000 to 8.3 Carbon Junction Mlne Paya 9 Mnual Hydrobgk RapoK for Water Yasr 2003