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Table 12 shows that Alluvial Vells b-A, 32-A, 33-A, 31-A2, 68-A, end 69-A, Wolf Creek • <br />Overburden Well 7-WCO and Spoils Wells 26-5, 27.5, and 61-5 all exceed the irrigation <br />dissolved manganese standard of 0.2 mg/l. This standard applies to crops grown in soils <br />with pH values lower than 6.0. In soils with a higher pN (as is found in agricultural <br />soils surrounding the Seneca II area), a more realistic standard would be 10 mg/l (EPA, <br />1976). <br />The irrigation dissolved iron standard of 5.0 mg/l was exceeded at alluvial Wells 32-A <br />and 33-A and Wolf Creek Overburden Yell 7-WCO. Water with this iron concentration will <br />precipitate iron oxides on the leaves when the crop is spray-irrigated, but should not be <br />a problem for flood irrigation (EPA, 1976). <br />Wadge Underburden Wells 8P1-U and 11-U and Yadge Coal YeLI 19-W exceeded the irrigation <br />fluoride standard of 2.0 mg/l. Yell 11-U also exceeded the irrigation pH standard of 6.5 <br />to 8.5. <br />Finally, water quality analyses performed on samples obtained at the Seneca II production <br />well (GW-SS-TC) during 1993 were compared against both primary and secondary drinking • <br />water standards developed for ground water by the CDOH (CDOH, 1986). Sulfates (secondary <br />standard, 250 mg/l) were higher than the CDOH standard: 360 mg/l, November 24, 1992; and <br />391 mg/L, June 29, 1993. Well GW-SS•TC has historically exhibited higher sulfate <br />concentrations than the secondary drinking water standard for this parameter. Also, the <br />November 24, 1992 sample exceeded the secondary standard for iron (0.3 mg/l) with a value <br />of 0.41 mg/l. However, bottled water is consumed et Seneca I1. <br />Ground Water duality Summary. Annual average TDS values at Yells 68-A, BP1-U, 25-5, 27-5, <br />and 62-5 in 1993 were higher then their historic ranges. TDS values at all other wells <br />fell within their historic ranges. CDOH agricultural ground water standards for <br />manganese, iron, fluoride, and pH were exceeded at certain monitoring wells. <br />In the area surrounding Seneca II, ground water is not being pumped for irrigation or <br />livestock watering purposes. The above discussion is provided only to serve as a <br />comparative basis to judge ground water quality. Domestic wells that provide drinking <br />water for local residents ere not from aquifers impacted by mining. Mining at Seneca 11 <br />is not believed to be causing the degradation of any monitored aquifer. • <br />8 <br />