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<br />Section D.7.3.2 Geochemical Characteristics <br />28. Please describe the processing and rinsing methods, concentration of <br />chemicals utilized, duration, etc. of the heap material prior to water quality <br />analyses. <br />29. Free cyanide concentrations of Sample No. 6, as presented in 4ppendix F, <br />measured .06 ppm; Rito Seco Receiving Stream Standards for free cyanide is <br />.005 ppm. Additionally, concentrations of other parameters analyzed in <br />Appendix F measured more than 2 orders of magnitude greater than those <br />standards set forth in the Receiving Stream Standards. Therefore, I don't <br />think it is fair to represent the leachate water quality results t~ be well <br />within the Rito Seco Receiving Stream Standards. Please provide parameter <br />measurements to correspond to the levels of detection as specified in the Rito <br />Seco receiving Stream Standards. <br />CAMILLE: Please Note: Check to determine which form of sulfur, i.e., total, <br />pyritic or peroxide oxidizable, should be reviewed against neutralization <br />potential to ascertain whether material is potentially acid producing. <br />Section D.7.4 Heap Leach Pad Design and Construction <br />Section D. 7.4.1 Pad Area <br />30. The narrative specifies the heap pad area to be approximately 1500 ft.. <br />by 1500 ft. (2,250,000 square ft. or approximately 52 acres), covering about <br />2,135,000 square ft, or approximately 52 acres), totalling 43 acres. Please <br />clarify. <br />31. Description of the pad stage connections explains that surface flows will <br />drain from one stage to another through spillways installed in the interstage <br />berms, and ultimately into the pregnant pond. However, the Heap Plan View, as <br />presented in Figure C-8, and the Heap Cross Sections illustrated in Figure <br />C-9, indicate that the heap will be a uniform surface, draining along a center <br />drain and perimeter berms. Please clarify. <br />32. The secondary liner is proposed to be a 12-inch thick natural soils <br />amended with bentonite to achieve a permeability rating of 1x10-6 cm/sec. <br />However, it is recommended that a compacted soil or clay not be used as a <br />secondary liner as any flows reporting to the leak detection or secondary <br />recovery system may erode the underliner along its flow path; a geomembrane <br />liner is therefore recommended for use as a secondary liner. Please address. <br />33. The primary 60-mil HDPE liner extending to the heap and pond perimeter <br />berms, illustrated on Figure C-8 and further detailed in Figures C-9 and C-10, <br />should be anchored such that the liner extends along an entire interior <br />surface of a "U" ditch, not only up one side of a "V" ditch, thereby providing <br />additional anchoring security. Please address. <br />34. Figure C-9 indicates that the perimeter heap transmittal ditch measures <br />approximately 10 feet in width, whereas Figure C-10 illustrates the ditch <br />width to be 10 inches. Please clarify. <br />