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• ug/1) which wa6 higher than the CDOH standard of 10 ug/1. Likewise, the same <br />two eamDles had lead values that were lase than an elevated detection limit (200 <br />ug/1 va. a normal deteetioa limit of 20 ug/1) which moss higher than the cDOH <br />standard of 100 uq/1. The cnuae of these elevated detection limits was e <br />8ecisioa by the laboratory to dilute the samples prior to aaalyaes Sa order to <br />reduce the e£fecie of interferences (Drimarily, high salinity). <br />Elevated levels of iron may be attributed to natural fi.e., not mining related) <br />conditions, since elevated levels for this parameter era not found in the <br />adjacent Seneca II spoil walla. The high levels of iron displayed is the one <br />alluvial well (YGAL15) may be the result of orpaaie matter aafl Dlaat 8abrie <br />preaeat in the alluvium (Hem, 1989, pg. 77). This wall displayed high levels of <br />iron prior to miaiag. <br />Aigh aulfnte value^ may, in part, ba due to recharge from the spoil aquifer. <br />However, it moat ba noted that the CDOH has ao ground water agricultural <br />standard for sulfate. This California staadar8 ie presented here merely for <br />• co~arative purposes. It should also be noted that all thirteen wells with high <br />aulfnte values this year exhibited high ^ulfsta values Drior to miaiag. <br />High manganese values may, is part, ba Qua to recharge from she spoil aquifer, <br />although high values are of tea common, especially is alluvial material (Hem, <br />1909, pge, 86-89). All three walla diaDlayiag high manganese valuae this year <br />also flid eo prior to mining. 2t should be noted that, while the CDOH uses a <br />standard of 0.2 mg/1, the EPA states that this atendard is used to protect crops <br />grown is soils with a DH value lower thaw 6,0. Ia soils with a higher pH (ne <br />are founfl in the Yoaet region), a more appropriate standard mould ba 10 mg/1 <br />(EPA, 1976). This year, no well displayed a value higher than 1.92 mg/1. <br />around Water Summary <br />Ia the Probable Hydrological Coaeequeacee (PHC, Tab 17, Attachment 17-5) section <br />o£ the Yoaet Hine PAP, predietioas were made ae to the expected TD9 increases to <br />be observed at various monitoring walla. The following table outlines these <br />• Dredictioae along with this year's observed average valuae (annual average for <br />bedrock wells, May-6eptember average £or alluvial wells). <br />7 <br />