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Mr. Alan Cox <br />November 30, 2007 Page 4 <br />Table 4 2004 Windy Gulch water quality <br />Parameter Agricultural <br />Standard Average at <br />Lower Weir ~'~ <br /> <br />3/26/04 Upper Weir <br /> <br />4/20/04 <br /> <br />5/16/04 <br /> <br />3/26/04 Lower Weir <br /> <br />4/20/04 <br /> <br />5/16/04 <br />luminum total (mg/I) None 0.36 2.74 3.43 2.43 <0.03 1.02 1.01 <br />senic dissolved (mg/1) 0.0023 0.0018 0.0029 0.0087 0.0146 0.0149 <br />senic total (mg/I) 0.10 0.038 0.005 0.0025 0.0027 0.008 0.0147 0.0175 <br />admium dissolved (mg/I) <0.005 <0.005 <0.005 0.035 <0.005 0.011 <br />admium total (mg/1) 0.010 0.017 <0.005 <0.005 <0.005 . 0.033 0.008 0.007 <br />opper dissolved (mg/1) <0.01 <0.01 <0.01 <0.01 <0.05 <0.01 <br />opper total (mg/1) 0.20 0.01 <0.01 <0.01 <0.01 <0.01 0.01 0.01 <br />ron dissolved (mg/l) 0.22 0.19 0.18 <0.01 0.23 0.1 <br />ron total (mg/1) None 0.48 2.14 1.77 1.27 <0.01 0.48 0.54 <br />anganese dissolved (mg/1) 0.061 0.009 0.019 0.028 0.008 0.089 <br />anganese total (mg/1) 0.20 0.144 0.161 0.038 0.024 0.028 0.012 0.087 <br />ercury dissolved (mg/1) <0.001 <0.0002 <0.0002 <0.001 <0.0002 <0.0002 <br />ercury total (mg/1) None <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 <br />inc dissolved (mg/1) <0.01 <0.01 <0.01 8.42 1.68 1.46 <br />inc total (mg/1) 2.0 3.85 0.01 <0.01 <0.01 8.22 1.75 1.46 <br />H (units) None 6.6 7.3 7.3 7.4 7.1 7 7.1 <br />onductivity (umhos/cm) None 371 72 44 50 1020 163 162 <br />DS (mg/l) None 278 100 100 110 890 170 140 <br />SS (mg/1) None 5 8 <5 <5 <5 <5 <5 <br />Sulfate (mg/1) None 159 20 10 20 450 80 60 <br />(1) Average from 16 samples taken since 1998 prior to final reclamation activities <br />The water quality at the lower weir location in Windy Gulch continues to improve from pre- <br />reclamation levels and from levels observed during 2004 and 2005. In 2006, a sample was not <br />collected during the initial spring runoff season due to the low flow conditions so there is only one <br />value in 2006 (April 27~') to compare to. Therefore, 2006 is not representative of the normal runoff <br />period. <br />The water quality in Windy Gulch met all established criteria for Windy Gulch with the exception of <br />total zinc levels at the lower weir sampling location during the initial spring runoff period. Two <br />samples in March of 2007 have levels of total zinc (i.e., 2.08 mg/1 and 2.17 mg/1) that are slightly <br />elevated over the agricultural standard of 2.0 mg/1. Levels of cadmium in 2007 met the agricultural <br />standards for all samples. TDS averaged 166 mg/1 in 2007 compared to higher levels of 180 mg/1 in <br />2006, 240 mg/1 in 2005 and 890 mg/1 in 2004, indicating a general downward trend in concentration <br />and an overall improvement in water quality with time. <br />We continue to see the highest constituent concentrations during the rising limb of the runoff <br />hydrograph with lower concentrations on the falling limb. This behavior is illustrated in Figures 3 <br />through 6, which show time series plots of zinc, cadmium, TDS and sulfate concentrations at the upper <br />and lower weir locations. This behavior is likely caused by the flushing of constituents from <br />sediments in the steam channel that have been subject to weathering prior to the spring runoff period. <br />Since Windy Gulch only flows during the spring, and even then not every year, there is a normal <br />accumulation of weathering products in the stream channel deposits. The low flows in 2006 may have <br />compounded this situation in 2007 since there was minimal flushing that occurred in 2006. <br />Taking the zinc concentrations shown in Figure 3 as an example, the first sample taken in 2004 after <br />completion of reclamation activities had a zinc concentration of over 8 mg/1. Additional samples in <br />