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monitoring site HGSD1 and 3 with the iron levels <br />reported to be 1.08 mg /I and 1.01 mg /I at each site <br />respectively. Neither NPDES outfall was discharging at <br />that time. The iron level decreased down gradient of <br />the site. <br />The chronic aquatic life total mercury standard (.01 <br />ug /1) was exceeded on June 21. NPDES outfall 1 was <br />discharging at that time; however no exceedance of <br />the effluent limitations were reported for that quarter. <br />The amount of mercury reported up- gradient and <br />down - gradient of the site was the same at the time of <br />the exceedance. Given this, it does not appear the <br />onsite activities impacted the mercury level. However, <br />this appears to be an unusual occurrence based on the <br />AHRs from the previous four years of monitoring data <br />submitted to the Division. This constituent will need <br />to be monitored closely to determine if this was a <br />limited occurrence. <br />The chronic selenium standard (4.6 ug /1) was <br />exceeded on June 21 at HGSD1 and 3. Outfall 1 was <br />discharging at that time; however no NPDES <br />exceedance of the effluent limitations were reported <br />for that quarter. Based on the last four years of <br />monitoring data submitted with the AHRs, it is not <br />uncommon to see an exceedance of this constituent <br />for the above referenced standard at HGSD1, the up- <br />gradient monitoring point. However the exceedance <br />was reported to have occurred both up- gradient and <br />down - gradient of the site unlike the previous four <br />years. At the up- gradient monitoring site (HGSD1) In <br />2008 the selenium level was reported to be 5.9 ug /I <br />and in 2010 it was reported to be 5.2 ug /1. The 2011 <br />level was reported to be 10.4 ug /I for the up- gradient <br />monitoring site and 15.0 for the down - gradient <br />monitoring site. This appears to be an unusual spike in <br />selenium in Dry Creek both up and down gradient of <br />the site. According to the AHR, these levels are likely <br />due to irrigation return water from the surrounding <br />hayfields upstream of the site. The Division believes <br />this is likely a contributing factor, however given the <br />exceedance is greater down - gradient of the site it may <br />not be the only contributing factor. <br />Other factors may be attributed to the exceedances <br />reported in 2011 such as elevated snowpack and <br />precipitation during the 2010 winter and 2011 spring. <br />At the time during and prior to the exceedances, the <br />Operator was conducting demolition of the loadout <br />facilities, backfilling, grading and top soiling activities <br />at the site. Also; in June, water pumping occurred at <br />the site into the rail loop pond due to run -off out of <br />