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confining layers of shale separated this aquifer from mined seams. All <br />values have been at or below 700 mg /1. <br />Comparison of Ground Water Quality to Water Use Standards. SCC has <br />compiled a list of ground water standards for agricultural uses (Table <br />5) . This list is composed of Colorado Department of Public Health and <br />Environment ground water standards (CDPHE, Reg. 41, May 2008). <br />Table 6 provides a comparison of ground water quality collected this <br />year to agricultural standards. This Paradox database generated table <br />does not include the units of concentration (mg /l or ug /1) for each <br />parameter. The units used for each parameter are the same as those <br />listed on the standards table (Table 5) and are also the same as those <br />used in the water quality reports. The frequency column on Table 6 <br />indicates, in this order: uncensored, that is, the number of exceedances <br />above the Method Detection Limit (MDL) / the number of exceedances <br />between the MDL and the Practical Quantitation Level (PQL) / censored, <br />that is, the number of sample values below the MDL but the MDL was <br />higher than the standard / the total number of samples. Below is a <br />summary of standards that were exceeded. Given in parenthesis is the <br />source and use of each standard. <br />Parameter # of Wells / # of Excursions <br />Boron (CDPHE, select plant species) 1/2 <br />Cadmium (CDPHE, irrigation) 2/2 <br />pH (CDPHE, irrigation) 2/2 <br />Iron (CDPHE, irrigation) 2/4 <br />Lead (CDPHE, livestock) 2/2 <br />Manganese (CDPHE, irrigation) 5/10 <br />The boron standard (750 ug /1) was exceeded twice at one site WW14 with <br />values of 980 ug /1 and 990 ug /l in the spring and fall respectively. <br />According to the CDPHE, the 750 ug /1 standard is set for sensitive crops <br />(CDCH, Reg. 41, 2008) , and that the limit otherwise is 5000 ug /1. None <br />of these sensitive plant species are grown commercially in this area. <br />This is also not an irrigation or livestock standard. <br />7 <br />