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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 />Parameter # of Wells / # of Excursions <br />Manganese ( CDPHE, irrigation) 2/4 <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 6.0. 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 />3.41 mg /1. <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 (0.35 mg /1) with a values of 3.61 mg /l in May and <br />3.05 mg /l in September. However, iron values upstream at alluvial Wells <br />SBAL68 (Bond Creek below Pond 008) and SCAL69 (Cow Camp Creek below PSCM <br />Pond 004) were less than 1.4 mg /l this year. Therefore, the high iron <br />values observed at Well SFAL72 are not likely to be the result of <br />discharges from the Seneca II Mine or the PSCM. The high levels of iron <br />displayed at this well are likely the result of naturally occurring <br />organic matter and plant debris present in the alluvium (Hem, 1989, pg. <br />77) at this particular location. <br />5 <br />