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6 4. The discussion of minimal Sage Creek flows (less than 0.25 cfs) referred to on page 16-3-6 does not appear to be supported by the data in Appendix 7-6. The figure on page 7-6-22 indicates flows upstream from the field at WSS4 exceeded 0.25 cfs throughout most or all of six growing seasons (1980-1985). Is this discussion based on data from WSSF3? If it is, please explain why WSSF3 data is more relevant to the discussion of flood irrigation potential in Section 30 than WSS4 data. This discussion is also presented on page 42 of Tab 17. The data referenced in this discussion does not appear to correspond to the data in Tab 7 (pp 7-6-22 through 24). Stream flow data for 1979- 1985 in Tab 7 does not support the discussion in Tab 17, and 1991 data referenced in the PHC does not appear to be included in Tab 7. Tab 17- Probable Hydrologic Consequences 5. The PHC projects total dissolved solids in lower Sage Creek will increase to 2118 mg/1, due in part to the impacts of spoil springs. Using a conversion factor of 1.4 for converting TDS to specific conductivity, this corresponds to a conductance of 2.9 umhos/cm. This would indicate a potential for material damage to the hydrologic balance outside the permit area, which must be addressed by the Division in its Cumulative Hydrologic Impact Study for the Yampa River basin, and by SCC in the PHC section of the permit (see Rules 2.07.6(2)(c) and 2.05.6(b)(viii)). The PHC needs to address the potential impacts to the hydrologic balance outside the permit area in the Sage Creek basin, specifically in terms of quality of water that is or may be used for irrigation. 6. The life-of-mine PHC information submitted in response to the Division's earlier request includes projections of salinity increases in ground and surface water due to mining, as well as reference to potential for material damage in regard to alluvial valley floors. The PHC also needs to address the other potential impacts due to mining in the Sage Creek watershed, including any impacts to existing domestic uses of water, and effects of disturbed area runoff outside the permit area. 7. Unless the potential for flood irrigation of the Section 30 field on Sage Creek is discounted, the PHC will need to address the potential for material damage to potential flood irrigated alfalfa production in this area.