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for each parameter are the same as those listed on the standards table <br />(Table 5) and are also the same as those used in the water quality <br />reports. The frequency column on Table 6 indicates the number of <br />exceedences out of the total number of samples (i.e., 1/2 indicates one <br />exceedence out of two samples). Below is a summary of standards that <br />were exceeded. Given in parenthesis is the source and use of each <br />standard. <br />Parameter # of wells / # of Excursions <br />Boron (CDPHE, irrigation) 1/1 <br />pH (CDPHE, irrigation) 2/2 <br />Iron (CDPHE, irrigation) 2/2 <br />Manganese (CDPHE, irrigation) 6/14 <br />Selenium (CDPHE, irrigation) 1/1 <br />In addition, samples from WOV14, WOV17 and WW14 had a cadmium values <br />that were less than an elevated detection limit (30 ug/l vs. a normal <br />detection limit of 3 ug/1), which was higher than the CDPHE standard of <br />10 ug/1. Likewise, the same samples had a lead value that were less than <br />an elevated detection limit (200 ug/l vs. a normal detection limit of 20 <br />ug/1), which was higher than the CDPHE standard of 100 ug/l. The cause <br />of these elevated detection limits was a decision by the laboratory to <br />dilute the samples prior to analyses in order to reduce the effects of <br />interferences (primarily, high salinity). <br />Elevated levels of iron may be attributed to natural (i.e., not mining <br />related) conditions, since elevated levels for that parameter are not <br />normally found in spoil wells at the adjacent Seneca II Mine. The two <br />bedrock wells (WW14 and WTC201) that often exhibit high levels may have <br />higher than usual concentrations of iron pyrite in the rock. Well WTC201 <br />(Trout Creek Sandstone, shop well) often displays high iron values, but <br />does not display an increasing trend. Wadge coal well WW14 started <br />displaying high iron values in 1998, with a peak value occurring in <br />2001. The high levels of iron occasionally displayed in the one alluvial <br />well (WHAL7-2) may be the result of organic matter and plant debris <br />present in the alluvium (Hem, 1989, pg. 77). Iron values at this well <br />9