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not found in PSCM spoil wells. However, elevated values of fluoride were <br />found in many wells before, as well as upgradient of�mining. In the case <br />of fluoride, the wells that have elevated levels this year have <br />historically displayed high levels. All three wells are also unique in <br />displaying a sodium bicarbonate type water with relatively high pH <br />values. It is suspected that the high fluoride values are related to <br />this type of water chemistry (Hem, 1989, pg. 121). All wells exist <br />within the PSCM permit boundary. <br />The elevated level of iron in May, 8.62 mg/l, in the alluvial well <br />SGAL71 may be the result of organic matter and plant debris present in <br />the alluvium (Hem, 1989, pg. 77). The September concentration decreased <br />to 2.42 mg/1. The iron standard is 5.0 mg/l. <br />High manganese values may, in part, be due to recharge from the spoil <br />aquifer, although high values are often common due to naturally <br />occurring geochemical conditions, especially in alluvial material (Hem, <br />1989, pgs. 86-89). Manganese exceedances have occurred at all alluvial <br />wells, including the one Grassy Creek alluvial well upstream of the PSCM <br />(Well 71) and one Wadge coal well located just west of NPDES Pond <br />002(Well 17). This standard is used to protect crops grown in soils with <br />a pH value lower than 6.0. In January 2008, CDPHE revised their ground <br />water agricultural standard to reflect this pH qualifier. In soils with <br />a higher pH (as are found in the PSCM region), a more appropriate <br />standard would b 10 mg /1 (EPA, 1976). This year, none of he PSCM <br />alluvial wells d splayed a value higher than 2.38 mg/1, and o spoil <br />wells displayed a,value higher than 5.71 mg/1. <br />In May, well SGAL70 exhibited an elevated concentration of selenium, <br />43.70 ug/l. The September concentration decreased to 0.30 ug/1. The <br />selenium standard is 20.0 ug/1. <br />Ground Water Points of Compliance <br />Ground Water Points of Compliance (GWPOC) have been established for the <br />PSCM (PSCM PAP page 2.04-103, Vol. 1). Attachment 7- of the Seneca II <br />PAP provides the details of how the standards were established. The <br />9 <br />