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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). Manganese exceedences occurred at all <br />but one alluvial well (Well 46), including the one Grassy Creek alluvial <br />well upstream of Seneca II (Well 711. It should be noted that, while <br />the CDOH uses a standard of 0.2 mg/1, the EPA states that this standard <br />is used to protect crops grown in soils with a pH value lower than 6.0. <br />Zn soils with a higher pH (as are found in the Seneca II region), a more <br />appropriate standard would be 10 mg/1 (EPA, 1976). This year, none of <br />the Seneca II alluvial wells displayed a value higher than 5.47 mg/l, <br />and no spoil wells displayed a value higher than 0.96 mg/l. <br /> <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 />mandatory) drinking water standards developed for ground water by the <br />CDOH. No human health standards were exceeded. The CDOH secondary <br />standard for sulfate, 250 mg/l, was exceeded twice with values of 400 <br />and 430 mg/1. Well STCS has historically exhibited sulfate <br />concentrations higher than the secondary drinking water standard for <br />this parameter. However, bottled water is consumed at Seneca II. <br />Ground Water Quality Summary. TDS values at twelve out of the nineteen <br />wells sampled the year displayed increasing TDS trends, although five of <br />those wells recently display stable or decreasing trends. TDS trends at <br />all other wells were either stable or decreasing. CDOH agricultural <br />ground water standards for pH, fluoride, iron, and manganese were <br />exceeded at certain monitoring wells. In the area surrounding Seneca <br />II, ground water is not being pumped for irrigation or livestock <br />watering purposes, nor has the CDOH classified any aquifer in this <br />10 <br />