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5). This list is composed of Colorado Department of Health ground water <br />standards (CDPHE, Reg. 41, May 2008). <br />Table 6 provides a comparison of ground water quality to agricultural <br />standards. This Paradox database generated table does not include the <br />units of concentration (mg/l or ug/1) for each parameter. The units used <br />for each parameter are the same as those listed on the standards table <br />(Table 5) and are also the same as those used in the water quality <br />reports. The frequency column on Table 6 indicates, in this order: <br />uncensored, that is, the number of exceedances above the Method <br />Detection Limit (MDL) / the number of exceedances between the MDL and <br />the Practical Quantitation Level (PQL) / censored, that is, the number <br />of sample values below the MDL but the MDL was higher than the standard <br />/ the total number of samples. Below is a summary of standards that were <br />exceeded. Given in parenthesis is the source and use of each standard. <br />Parameter <br />pH (CDPHE, irrigation) <br />Iron (CDPHE, irrigation) <br />Manganese (CDPHE, irrigation) <br /># of Wells / # of Excursions <br />2/2 <br />3/3 <br />4/4 <br />Elevated levels of iron (i.e., greater than 5 mg/1) may be attributed to <br />natural (i.e., not mining related) conditions, since the highest level <br />of iron found in spoil springs at this mine is 2.84 mg/1. The one <br />bedrock well (WW14) that often exhibit high levels may have higher than <br />usual concentrations of iron pyrite in the rock. The high levels of iron <br />displayed in the two alluvial wells this year may be the result of <br />organic matter and plant debris present in the alluvium (Hem, 1989, pg. <br />77). Well WHAL7-2 displayed high levels of iron prior to mining. <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). This standard is used to protect crops <br />grown in soils with a pH value lower than 6.0. In January 2008, CDPHE <br />revised their ground water agricultural standard to reflect this pH <br />qualifier. In soils with a higher pH (as are found in the Seneca II-W <br />7