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the surface water in the system as would be expected. No effects to alluvial ground <br />water quality or quantity are anticipated. <br />Surface Water Effects <br />McClave Canyon is an ephemeral drainage which is normally dry. Flows that do occur <br />are in response to snowmelt or intense rainstorms, and are usually of short duration. <br />McClane Canyon drainage is tributary to East Salt Creek, which is an intermittent <br />tributary of the Colorado River. Water quality is typical of and climate, ephemeral <br />and intermittent systems located in marine deposited sedimentary land forms. <br />Dissolved constituents often reach very high levels following dry periods and during <br />the winter, when stream flows are made up almost entirely of recharge from ground <br />water and from stagnant or semi -stagnant pools. Suspended solids levels are high <br />during spring runoff and following high intensity rainstorms, due to sparse vegetation <br />and erodible soils. <br />Due to the limited areal extent of surface disturbance, existence of effective sediment <br />control measures, and small quantity and acceptable quality of projected minewater <br />discharge, operations at McClave Canyon have had little effect on the quality of water <br />in McClave Canyon drainage or East Salt Creek, and no significant effects are <br />expected. A full suite analysis of mine discharge water presented in Table 6 of the <br />2002 AHR shows a total dissolved solids (TDS) value of 1810 mg/l, compared to TDS <br />values of 3000 to 4000 mg/l documented for East Salt Creek, at monitoring sites SW - <br />1 and SW -8, in Table 4 of the AHR. Following the conclusion of mining, all culverts <br />and diversions will be removed, and a network of ephemeral drainages in geomorphic <br />balance with adjacent areas will be reconstructed on the disturbed area. Following <br />successful vegetation establishment it is expected that surface water hydrologic <br />characteristics of the reclaimed area will approximate pre -mining conditions. <br />In association with RN -06 and TR -15, the operator prepared amass balance evaluation <br />to assess the effects of irrigation season mine water discharge on the salinity <br />(conductivity) of East Salt Creek water downstream from the point where discharge <br />water enters the stream. The evaluation included data from the 2001 through 2005 <br />irrigation seasons. During four of the five years, conductivity levels were reduced due <br />to dilution by lower conductivity mine discharge water. During one of the 5 years <br />(2005) there was a slight, but insignificant (0.2%; 0.004 mmho) increase. Over the <br />five year period, there was an over-all 10.9% reduction in irrigation season <br />conductivity on East Salt Creek downstream of the mine, resulting from minewater <br />discharge. These results confirm that mine discharge is not causing a deleterious <br />increase in stream salinity levels. <br />IV. TOPSOIL — RULE 4.06 <br />Soils resource information, including soil series descriptions, and evaluation of mine bench <br />materials for use as plant growth medium is provided in Section 4.4 of the permit <br />application. Information on topsoil management is provided in Sections 2.3 and 3.2, and <br />information on topsoil replacement is provided in Section 3.3. <br />27 <br />