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RULE 2 PERMITS <br /> of the iron present is not in an available form, but is bound to suspended sediment particles as are <br /> many other constituents. <br /> Figure 2.04.7-11 presents the data for total recoverable manganese in the area watersheds. Mean <br /> values are around 1000 ug/1 while the range of values is from 0.0 ug/1 to greater than 10,000 ug/1. <br /> Once again, the seasonal and flow dependent nature of water quality in the mine area is <br /> documented. Manganese is important only to drinking water standards. Since the surface water in <br /> this area is not used in this manner, manganese is not a problem in these watersheds. <br /> The LRCWE (1979) study was cited earlier and an explanation given that it was not included in <br /> the mathematical data analyses because the data were not continuous. These data are, however, <br /> indicative of the conditions of water quality at a larger number of sites and types than the data <br /> presented earlier. These data were presented earlier in Table 2.04.7-3 which gives a listing of the <br /> site numbers, site type, and conditions for 64 sampling stations on 9/19/79. Parameters measured <br /> were temperature(°C)and specific conductivity(mmhos/cm).Natural variability within the permit <br /> and adjacent areas is, again, shown between sites for a single sampling date. Further discussion of <br /> the effects of this variability and degree of water quality impacts is given in the Hydrologic <br /> Consequence Section, 2.05. <br /> Sediment Yield and Loss Rates <br /> Suspended sediment data is presented here separately from the water quality data for other <br /> constituents of concern. Suspended sediment concentrations are a function of many variables <br /> including precipitation patterns, soil types, vegetative cover, surface areas disturbed, slopes and <br /> drainage density. Suspended sediments are important from land productivity and aquatic habitat <br /> perspectives. <br /> Sediment yield estimates have been calculated by each investigation and are briefly summarized <br /> here. The EMRIA Report estimated sediment yield based on a method developed by the Pacific <br /> Southwest Interagency Committee in 1968 and assumed that the entire mine lease area was made <br /> up of seven homogeneous basins. Extrapolations of the per basin estimates were extended to <br /> include the entire drainage area. No data were collected to substantiate the model at that time. <br /> However, the EMRIA report concluded that the sediment yields during and after reclamation <br /> would not be excessive. <br /> VTN analyzed water quality data for suspended sediments for the period November, 1974 through <br /> July, 1975 for Goodspring Creek. Mean daily sediment concentrations ranged from a low of 58 <br /> mg/1 in November to a high of 310 mg/1 in May. These data reflect the climatic conditions with <br /> low values during low flow periods and increasing values occurring with spring runoff. Table <br /> 2.04.7-21 is a presentation of this data. VTN also analyzed suspended sediment data for Wilson <br /> Creek below the confluence with Taylor Creek. These data were collected for the period <br /> December, 1974 to September, 1975.Table 2.04.7-22 presents this information.Mean daily values <br /> are higher than those for Goodspring Creek but still reflect the seasonal effects described <br /> previously.. Since that report it became apparent that the Wilson Creek drainage was more <br /> susceptible to erosion than Goodspring Creek. Bank erosion on Wilson Creek during the <br /> cxcc3sivcly high runoff in 1984 is morc appropriatcly dcfincd as mass wasting. It has bccn <br /> Rule 2 Permits 2.04-29 Revision Date: 12/20/19 <br /> Revision No.: TR-135 <br />