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<br /> <br />Memo to Steve Renner - 5 - January 4, 1989 <br />25. The haul road crossing at the Rito Seco includes placement of fill within <br />the channel. As such, it appears a 404 permit will be required. Please <br />submit a copy of this permit for our files when available. <br />26. It appears no erosion control/runoff control measures have been <br />identified for the mill and concentrated-ore stockpile areas. Wi11 a <br />small ditch/berm similar to a roadside ditch be located around the <br />perimeter of either area? <br />27. Tne sediment control structures shown on Figure D.9-2 will be constructed <br />of rock fill. Are these expected to be fairly permeable structures given <br />the rock type to be used? <br />28. The reclamation of the permanent diversions, sediment check dams and <br />drainage crossings are not described in the reclamation plan. For each <br />of the structures to be constructed and used during mining, please <br />provide a description of the reclamation planned to occur for each and a <br />schedule of when this will be performed relative to the other reclamation <br />activities. <br />Exhibit G - l9ater Resources <br />29. The interpretation is made on page G-13 and G-50 that no measurable gains <br />or losses in streamflow occur through the mining property. A comparison <br />of Tables G.2-2 and G.2-3 indicate there to be predominantly losses <br />occurring of varying magnitude along the reach. The data indicate on the <br />occasions of a gain the amounts are generally of lesser magnitude. Is <br />the variability due to the accuracy of the staff gage estimates based on <br />Manning's n values chosen or attributable to actual streamflow conditions? <br />30. The water quality data for the three surface water stations presented in <br />Tables G.2-6 through G.2-8 indicate many of the metals to be below the <br />detection limits available from the analytical procedures used. Although <br />this information is useful to a certain extent, these concentrations of <br />metals and trace elements should be compared to receiving stream <br />standards and, where appropriate, consideration given to modifying the <br />procedures to provide lower detection limits in the continuing monitoring <br />program. <br />31. Has consideration been given to including biomonitoring as part of the <br />water quality monitoring program? <br />G.5 - Evaluation of the Hydrologic Impacts Due to Mining <br />32. No statement is made on the probable hydrologic impacts on surface water <br />due to the mining contemplated. Although the continuing surface water <br />monitoring program is designed well to denote any changes, are any <br />changes in streamflow, water quality or sediment loading exoected during <br />the mining and reclamation phases of the operation? <br />2319E/scg <br />