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On Page 7-247 0! the Seneca II Mina Probable Hydrologic Consequences (PHCI , Predlctrons <br />rare made !or the TDS increases to ba observed an Fish Creak during the months of June and • <br />July due to dischazges from the Seneca II Minn. In Juno, end increase from 421 to 197 <br />mq/1 rsa predicted, chile an incranae from 390 to 450 mg/1 was observed this year. In <br />July, sn increase from 533 to 607 mg/1 rns predicted, chile a decrease from 720 to 610 <br />mg/1 rsa observed! This decrease may be dve to temporal variatroas of the xates quality <br />of Pish Creak. It appears that the Seaaca IZ Mine has little impact on Fish Creek. Water <br />discharged from the mine is loot to stock ponds, avapotrmspiratron, sad the alluvium as <br />it !lore through Trentymile Park. Dissolved solids from mina discharges aza diluted <br />during the anormelt runof! in March and April (prior to the irrigation season) by high <br />stream flows rith relatively for TDS concentrations. The natural conditions in Trentymile <br />Park appear to haw a much greater impnet on the rater quality of Fish Csaek. <br />Little Creasy Craak Drainage. Tro monitoring cites lie rithin the Little Grassy Craak <br />drainage: Surface Water Site SW-52-5, loeate6 in the •ovthrest portion of the permit area <br />and WPDES Dischazge Point 002, also kno~m as the Wedge Imp^+•^•+•^^^t. <br />Surface Water Sita SW-S2-5 (SSLGS). Site 5 drains the upper reaches of Little Cressy <br />Creek rhich ass undisturbed by mining. Comparisons of its hydrograph to that of WPDE9 002 • <br />indicates that Site 5 is s relatively minor contributor to the floc in this basin. <br />WPDES Diechazge Point 002 (WPDE52). Hydsographs based on raekly floc measurements aza <br />preaentad in Appendix D. The hydrographs conaiet of fro pages, the first is for data this <br />yeaz, and the second shore all historical data. Raviar of the second hydrogssph shore <br />that this year's peak flow rsa among the highest on record. This is also confirmed by the <br />following table, rhich liata the average of raekly floc measurements for each year, rhirh <br />ehors that this year's average floc rsa the third highest on record. <br />1997WY (Water Year) = 1.242 cfs <br />1996171! 1.d00 cfs <br />1995WY = 0.386 cfs <br />1994WY 0.116 cfs <br />I993WY 0.602 cta <br />1992WY = 0.072 cfs <br />1991WY = 0.072 cfs <br />1990WY = 0.076 cfs <br /> <br />198 • <br />9WY 0.181 cfs <br />12 <br />