2009-02-26_REPORT - C1982057 (10)

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quantity data for the current water year, and followed by remarks if present. This is followed by a TDS regression plot using the LOWESS method (see the Ground Water Quality section), and a listing of historic percent milliequivalent values for major ions and TDS values. A statistical report representing baseline (i.e., premining) data for each site downstream of mining (when available) is provided in Appendix E1. On this statistics report, "censored data" refers to analytical values that were below the detection limit, which were censored from the min/max/mean calculations. The time frame for baseline conditions is listed under "conditions specified" at the bottom of each page. The following discussion of water quality will limit itself to a description of TDS trends. A separate section, Comparison of Surface Water Quality to Water Use Standards, will list those samples that exceed water use standards. Lab samples are handled in a matter identical to what was discussed earlier in the ground water section. For the sake of brevity, the prefix that precedes all surface water site names will often be dropped throughout this report. As an example, Site SW-S2W-SG7 (WSH7) will be referred to as Site 7. Hubberson Gulch / Dry Creek - Surface Water Site SW-S2W-SG9 (WSH9). This Hubberson Gulch site is upstream of NPDESI7 and all other mine related discharges in the II-W South Expansion area. Monitoring at this site began in August 1997. No monitoring was performed in the 1999 calendar year, but was resumed in 2000. This site is monitored in June and September. - NPDES 017 (NPDESI7). This site exists on Hubberson Gulch in the II-W South Expansion area. Construction of Pond 017 began on October 14, 2002 and was completed in December 2002. This year, flow was continuous. It is monitored weekly, except when inaccessible by truck. Average flow for each water year was: 2008 0.272 cfs 2007 0.163 cfs 2006 0.162 cfs 12