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concentrations were below the detection limit of <0.01 mg/L at all sites for all sampling dates <br />of 2008. <br />3.3.11 Surface Water Nitrite <br />r Chart 16 shows nitrite concentrations for monitoring sites TR-A, TR-B, TR-C and TR-D for <br />the period of record. Nitrite concentrations have been consistently below detection limits with <br />few exceptions. Nitrite was elevated at site TR-D with a value 0.32 mg/L in April 1999. This <br />' value is not consistent with historical data or the other monitoring sites during the April 1999 <br />monitoring event. The April 1999 TR-D value is considered to be a sampling/laboratory <br />¦ error. <br />The nitrite concentration upstream of the mine at TR-A was 0.06 ppm in the July 2001 <br />sample. The concentration decreased as it passed by the mine site as a result of dilution. <br />Samples collected in May and October 2001 show nitrite levels at TR-A below the detection <br />limit. The 2008 sampling period shows consistent sampling results compared to all previous <br />events. Nitrite concentrations were below the detection limit of <0.01 mg/L at all sites for all <br />sampling dates of 2008. <br />3.3.12 Surface Water Orthophosphate <br />Chart 17 shows orthophosphate concentrations for monitoring sites TR-A, TR-B, TR-C and <br />TR-D for the period of record. Values obtained for orthophosphate have been low with most <br />being below detection limits throughout the duration of monitoring. Orthophosphate showed <br />some perturbation during the 2001 sampling period at TR-B. However, concentrations <br />downstream of TR-B are consistent with previous sampling results. Therefore, either sample <br />contamination or laboratory error is suspected. The 2008 sampling period shows slightly <br />elevated sampling results compared to the period of record. The lowest orthophosphate <br />concentration in 2008 was the lower detection limit of <0.01 mg/L recorded at all sites in <br />October and the high was recorded at all monitoring sites in April and August with a value of <br />0.02 mg/L. <br />3.3.13 Surface Water Chloride, Potassium and Iron <br />Charts 18, 19 and 20 show chloride, potassium and iron concentrations for monitoring sites <br />TR-A, TR-B, TR-C and TR-D for the period of record. Chloride and potassium were added to <br />the monitoring program in 1993 while iron was added in 1994. The concentrations of all of <br />these parameters in Trout Creek water are generally low. The 2008 sampling period shows <br />consistent sampling results to the previous monitoring events regarding these constituents. <br />Chloride and potassium have shown a trend decrease and stabilization over the past decade. <br />Iron levels during the past few monitoring periods slightly decreased relative to those since <br />2004 showing a general relation to flow in Trout Creek. The lowest chloride concentration in <br />2008 was <1.0 mg/L at monitoring site TR-D in August and TR-A in October and the high <br />was recorded at monitoring site TR-C in April with a value of 3.0 mg/L. The lowest <br />potassium concentration in 2008 was recorded at monitoring site TR-A in August with a value <br />8