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standard of 10 ug/l. Likewise, the same samples had a lead value that <br />were less than an elevated detection limit (200 ug/1 vs. a normal <br />detection limit: of 20 ug/1), which was higher than the CDPHE standard of <br />100 ug/l. The cause of these elevated detection limits was a decision by <br />the laboratory to dilute the samples prior to analyses in order to <br />reduce the effects of 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 and displays an increasing trend. <br />The high levels of iron occasionally displayed in the one alluvial well <br />(WHAL7-2) may be the result of organic matter and plant debris present <br />in the alluvium (Hem, 1989, pg. 77). Iron values at this well are not <br />increasing. All wells with high iron values exist within the Seneca II-W <br />permit boundary. <br />High manganese values may, in part, be due to recharge from the spoil <br />aquifer, although high values are often common, especially in alluvial <br />material (Hem, 1989, pgs. 86-89). It should be noted that, while the <br />CDPHE uses a standard of 0.2 mg/1, the EPA states that this standard is <br />used to protect crops grown in soils with a pH value lower than 6.0. In <br />January 2008, CDPHE revised their ground water agricultural standard to <br />reflect this pH qualifier. In soils with a higher pH (as are found in <br />the Seneca II-W region), a more appropriate standard would be 10 mg/1 <br />(EPA, 1976). This year, none of the Seneca II-W wells displayed a value <br />higher than 3.03 mg/1. <br />One well, WW14, exhibited boron values, 1020 and 1070 ug/1, which <br />exceeded the CDPHE standard of 750 ug/l. According to the CDPHE, the 750 • <br />ug/1 standard is set for sensitive crops (CDPHE, Reg. 41, 1999), and <br />10 <br />