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ground water. This is due to the low hydraulic conductivities of the bedrock units. Other factors, <br />including attenuation and dilution further limit water quality impacts to a close down -gradient <br />proximity. Furthermore, confining layers isolate mine -impacted water bearing units from the <br />nearest usable aquifer, the Trout Creek Sandstone, which lies approximately 300 to 400 feet <br />below the Wadge Coal seam and approximately 60 to 100 feet below the Wolf Creek Coal seam. <br />B)Instream Numeric Standards (CWQCC Regulation 33) <br />PSCM discharges surface runoff and spoil leachate into Segment 13g (All tributaries to Fish <br />Creek from the confluence with Cow Camp Creek to the confluence with Trout Creek) of the <br />Yampa River based on Colorado Water Quality Control Commission (CWQCC) Regulation 33. <br />Regulation 33 was recently revised in August2014 as part of the Upper Colorado River Basin <br />Rulemaking Hearings. PSCM is required to monitor 17 parameters (as shown in Table 5) in that <br />segment per its CDPS and CDRMS permits. Table 6 provides a statistical summary of the water <br />quality for years 2011 to 2015 for PSCM's NPDES Outfall NPDES4 and Stream Sites SSC6, <br />SSC10, SSF11 and SSF13. Table 7 provides a comparison of those data with the Segment 13g <br />standards. This Paradox database generated table does not include the units of concentration <br />(mg/1 or ug/1) for each parameter. The units used for each parameter are the same as those listed <br />on the standards table (Table 5) and are also the same as those used in the water quality statistical <br />summary reports. <br />The frequency column in Table 7 indicates the following: <br />1. Exceedances above the Method Detection Limit (MDL)(uncensored) <br />2. Exceedances between the MDL and the Practical Quantitation Level (PQL) <br />3. The number of sample values below the MDL where the MDL was higher than the <br />standard (censored) <br />4. The total number of samples. <br />Data contained in Table 7 indicates the total recoverable (TR) iron standard, 1.0 mg/1 was <br />exceeded a total of nine times (out of sixteen samples) at Fish Creek Sites SSF11 and SSF13. <br />High TR iron values are normally associated with high total suspended solids. No excursions of <br />this standard occurred upstream at SSC10 (Cow Camp Creek, NPDES4 basin), SSB12 (Bond <br />Creek, NPDES8 basin. In addition, no NPDES discharges (NPDES8 at Seneca and NPDES4 at <br />27 <br />