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The GWPOC well in the Fish Creek alluvium is Well SFAL72 (aka, Twentymile Coal Company <br />Well 008 -AU -3), which is located less than one mile downstream of the Bond Creek (Seneca II <br />Mine NPDES Pond 008 basin) confluence. It is approximately four miles downstream of the <br />PSCM permit boundary. PSCM discharges into Fish Creek by way of Pond 004 (formerly <br />NPDES4 prior to 2016), which is located in the headwaters of Cow Camp Creek. Pond 004 is <br />fed by SSSPGI and SSSPG2, which are identified as NPDES6 and NPDESS respectively, post <br />January 1, 2016 when a new CDPHE discharge permit was issued. Table 1 provides the Fish <br />Creek alluvial GWPOC water quality standards established in TR -47. Table 2 provides a statistical <br />summary of the water quality for the years 2011 to 2015 collected at Well SFAL72. The only <br />standard that was exceeded was iron (0.35 mg/l, dissolved) with values ranging between 2.16 and <br />5.16 mg/1. However, total recoverable iron values for the last four years upstream at all spoils <br />springs (SSSPG9 at Seneca; and SSSPGI and SSSPG2 at the PSCM) were less than 0.71 mg/1. <br />From 2011 through 2015, total recoverable iron in NPDES discharges (NPDES008 at Seneca <br />and NPDES4 at the PSCM) were less than 0.32 mg/l. During 2014, NPDES discharges from <br />both outfalls featured total recoverable iron at values less than 1.0 mg/1 with the exception of the <br />January 2014 sample collected at NPDES4 that measured 1.55 mg/l. Therefore, the high iron <br />values observed at Well SFAL72 are not likely to be the result of discharges from the Seneca II <br />Mine or PSCM. The high levels of iron displayed at Well SFAL72 are more likely the result of <br />naturally occurring organic matter and plant debris present in the alluvium (Hem, 1989, pg. 77) at <br />this particular location. <br />The GWPOC wellin the Grassy Creek alluvium is Well SGAL70 (aka, Well GW -S70 -A). This <br />well is located about 0.6 miles downstream of the PSCM permit boundary. PSCM NPDES <br />Outfall 002 (NPDES2) discharges into Grassy Creek by way of Little Grassy Creek. Table 3 <br />provides the Grassy Creek alluvial GWPOC water quality standards established in TR -47. Table 4 <br />provides a statistical summary of the water quality for years 2011 to 2015 collected at Well <br />SGAL70. No exceedances of those standards were observed on samples collected from Well <br />SGAL70 in the past five years. <br />TR -47 also addressed bedrock aquifers. Bedrock GWPOC wells were deemed not necessary <br />based on the absence of the potential for the mine to negatively impact the quality of bedrock <br />26 <br />