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Elevated levels of iron. and fluoride may be attributed to natural (i.e., . <br />not mining re lated) conditions, since elevated levels for those <br />parameters are not found in Seneca II spoil wells. In the c ase of <br />fluoride, three of the wells (SP1, 1 1 and 19) that have elevated levels <br />have historically displayed high levels. Those wells are also unique in <br />displaying a sodium bicarbonate type water; with almost no calcium, <br />magnesium, or sulfates; and with relatively high pH values. It is <br />suspected that the high fluoride values are related to this type of <br />water chemistry (Hem, 1989, pg. 121). All three wells exist within the <br />Seneca II permit boundary. <br />In the case of iron, the one Wadge Underburden well (7) exhibiting high <br />levels may have high than usual concentrations of iron pyrite in the <br />rock. The high levels of iron displayed in the two alluvial wells (32 <br />and 33) may be the result of organic matter and plant debris present in <br />the alluvium (Hem, 1989, pg. 77). All these wells have historically <br />exhibited high iron values and all exist within the Seneca II permit <br />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). Of the twelve wells displaying high <br />values, only seven (SGAL70, SLGAL3IA, SLGAL32, SLGAL6, SSP61, SSP62 and <br />SWU7) are indicating an increasing trend. The one Grassy Creek alluvial <br />well upstream of Seneca II (71) also displays high values. It should be <br />noted that, while the CDOH uses a standard of 0.2 mg/1, the EPA states <br />that this standard is used to protect crops grown in soils with a pH <br />value lower than 6.0. In soils with a higher pH (as are found in the <br />Seneca II region), a more appropriate standard would be 10 mg/1 (EPA, <br />1976). This year, none of the Seneca II alluvial wells displayed a <br />value higher than 5.03 mg/1, and no spoil wells displayed a value higher <br />than 1.30 mg/l. <br />Finally, water quality analyses performed on samples obtained at the <br />Seneca II shop well (STCS) for this year were compared against both <br />human health (mandatory) and secondary (i.e., recommended but not <br />10 <br />