REP43279 - Laserfiche WebLink

Home Browse Search

r~ ~_~ - Trout Creek Sandstone. Well WTC201 is used as the water supply well for the mine facilities. It displays an increasing TDS trend; however, the peak TDS value occurred in June 1999. It is unlikely that the TDS increases observed at this well are due to mining impacts, since confining layers of shale separated this aquifer from mined seams. Comparison of Ground Water Quality to Water Use Standards. SCC has compiled a list of ground water standards for agricultural uses (Table 5). This list is composed of Colorado Department of Health ground water standards (CDOH, Reg. 41, November 2004). Table 6 provides a comparison of ground water quality to agricultural standards. This Paradox database generated table does not include the units of concentration (mg/1 or ug/1) for each parameter. The units used for each parameter are the same as those listed on the standards table (Table 5) and are also the same as those used in the water quality reports. The frequency column on Table 6 indicates the number of exceedences out of the total number of samples (i.e., 1/2 indicates one exceedence out of two samples). Below is a summary of standards that were exceeded. Given in parenthesis is the source and use of each standard. Parameter # of wells / # of Excursions Boron (CDOH, irrigation) 1/2 pH (CDOH, irrigation) 3/4 Iron (CDOH, irrigation) 3/4 Manganese (CDOH, irrigation) 6/12 In addition, one sample (from WOV17) had a cadmium value that was less than an elevated detection limit (30 ug/1 vs. a normal detection limit of 3 ug/1), which was higher than the CDOH standard of 10 ug/l. Likewise, the same sample had a le ad value t hat was less than an elevated detection limit (200 ug/1 vs. a normal detectio n limit of 20 ug/1), which was higher than the CDOH standard o£ 100 ug/1 . The cause of these elevated detection limits was a decision by the laboratory to 10