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and the Practical Quantitation Level (PQL) / censored, that is, the <br />number of sample values below the MDL but the MDL was higher than the <br />standard / the total number of samples. Below is a summary of standards <br />that were exceeded. Given in parenthesis is the source and use of each <br />standard. <br />of Wells / of Excursions <br />Manganese (CDPHE, irrigation) 2/4 <br />Iron (CDPHE, irrigation) 1/1 <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). Manganese exceedances have previously <br />occurred at all alluvial wells. This standard is used to protect crops <br />grown in soils with a pH value lower than G.O. In January 2008, CDPHE <br />revised their ground water agricultural standard to reflect this pH <br />qualifier. In soils with a higher pH (as are found in the Seneca II <br />region), a more appropriate standard would be 10 mg /l (EPA, 1976). This <br />year, none of the Seneca II alluvial wells displayed a value higher than <br />3.49 mg /l. <br />The high levels of iron displayed in Fish Creek alluvial well 72 may be <br />the result of organic matter and plant debris present in the alluvium <br />(Hem, 1989, pg. 77). <br />Ground Water Points of Compliance <br />A GWPOC have been established for the Seneca II Mine. Attachment 7 -3 <br />(Tab 7) of the Seneca II PAP provides the details. <br />The ground water standards for Fish Creek Alluvial Well SFAL72 are <br />provided in this AHR on Table 7. The only standard that was exceeded <br />this year was iron with values of 5.03 and 2.88 mg /l. However, the <br />maximum iron value observed this year upstream at Alluvial Well SBAL68 <br />was 0.90 mg /l. Therefore, the high iron values observed at Well SFAL72 <br />are not likely to be the result of discharges from the Seneca II Mine. <br />5 <br />