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d) An additional mass balance analysis is requested, and should be <br />included in Section 4.1.2.5. The analysis is necessary to assess the <br />projected effect of minewater discharge on average irrigation <br />season salinity (conductivity) on East Salt Creek waters diverted <br />for irrigation of the AVF downstream of the confluence of <br />McClave Creek and East Salt Creek. The analysis requested <br />would be a reTinement of the table presented on amended page 3 of <br />Appendix N. The Appendix 3 table uses worst case assumptions <br />for minewater TDS; East Salt Creek data is presented for specific <br />sampling events. <br />Several modifications are requested to provide an analysis that will <br />address whether mine discharge salinity may have the potential to <br />materially damage the quality of East Salt Creek water used to irrigate <br />downstream alluvial valley floors. First, salinity data should be <br />presented as conductivity values, to allow for comparison with suspect <br />levels and evaluations as presented in the Division's 1987 material <br />damage guideline. Second, for East Salt Creek, a flow rate and <br />salinity level that reflects avera a irrigation season values will need to <br />be used in the analysis, A corresponding average discharge water <br />conductivity value (rather than worst case) may also need to be used in <br />the evaluation. If initial analysis based on these factors indicates that <br />mine discharge would increase the average irrigation season <br />conductivity on East Salt Creek (and the conductivity would exceed <br />1.0 millimhos/cm), further site specific investigations maybe <br />warranted, as described in the guidelines. <br />20. Updated text regarding water depletion projections and USFWS Biological <br />Opinion documentation (Appendix P) was provided as requested. Item <br />Resolved. <br />21. Amended threatened and endangered species documentation was provided as <br />requested. Item Resolved. The information has been forwarded to OSM, and <br />OSM has prepared a Biological Opinion and submitted a request to USFWS to <br />initiate formal Section 7 consultation (Enclosure B). The information was <br />also forwarded to CDOW (see response in Enclosure D). The Division will <br />contact appropriate personnel at USFWS and CDOW regarding a minesite <br />visit in the near future, which maybe of some assistance in addressing any <br />remaining questions or concerns of these agencies. <br />