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RULE 2 PERMITS <br />Mean concentrations and levels of various constituents of concern were calculated along with <br />corresponding maximums, minimums and standard deviations. Figures 2.04.7-6, 2.04.7-7, 2.04.7-8, <br />2.04.7-9, 2.04.7-10 and 2.04.7-11 present this information for Wilson Creek at two locations and Taylor <br />Creek at the mouth. These data were a result of calculations with the Statistical Analysis System (SAS) <br />program on the USGS WRD computer. The data from which these figures were developed are found in <br />Exhibit 7A. <br />Figure 2.04.7-6, pH, shows no difference between each of these watersheds. The water is basic although <br />minimum values near 7.0 reflect the effect of rainstorms in the permit area. Rain often has pH levels of <br />neutral to acid conditions depending on the cloud and vapor sources. <br />Figure 2.04.7-7 presents the total dissolved solids (TDS) calculations in mg/1 for these areas. TDS levels <br />in all drainages are high except that there is a significant difference in the value for Taylor Creek. Taylor <br />Creek TDS levels are lower than the other two drainages. This is due, in large part, to the tentative nature <br />of streamflows and lack of a significant groundwater input. TDS is a function of contact time between the <br />rock/mineral surface and the water molecule. In the Taylor Creek watershed this contact time is much <br />less, as evidenced by the lack of flows most of the time. (See the Occurrence of Surface Water Section for <br />a description of Surface Flows). Wilson Creek shows no appreciable difference from Goodspring Creek. <br />Total Suspended Solids (TSS) are the most variable constituents of those shown. Figure 2.04.7-8 presents <br />the results of the TSS calculations for Wilson Creek at two stations and Taylor Creek at the mouth. <br />Maximum values exceed 10,000 mg/1 and minimum values approach zero. Mean values are 5000+ mg/1 <br />for Wilson Creek and 1000+ mg/1 for Taylor Creek. Standard deviations further show the extreme, <br />natural variability in this parameter as a function of precipitation, streamflow and season. <br />Figures 2.04.7-9 and 2.04.7-10 present the data for total recoverable and dissolved iron (ug/1), <br />respectively. Mean total recoverable iron concentrations are similar for all drainages and are within the <br />range of values presented in earlier reports. The ranges and standard deviations also show the extreme <br />natural variability of this metal in the mine area. Iron is a ubiquitous soil material and total recoverable <br />values are pertinent only if highly visible iron deposits are noticed in the stream bed. Earlier field <br />verification has shown that no such deposits exist. Therefore, iron is not a problem in the mine area. <br />Dissolved iron values are low and average less than 50 ug/l. Drinking water and aquatic life standards are <br />not exceeded. Based on the data, it is obvious that the majority of the iron present is not in an available <br />form, but is bound to suspended sediment particles as are many other constituents. <br />Figure 2.04.7-11 presents the data for total recoverable manganese in the area watersheds. Mean values <br />are around 1000 ug/1 while the range of values is from 0.0 ug/1 to greater than 10,000 ug/1. Once again, <br />the seasonal and flow dependent nature of water quality in the mine area is documented. Manganese is <br />important only to drinking water standards. Since the surface water in this area is not used in this manner, <br />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 the <br />mathematical data analyses because the data were not continuous. These data are, however, indicative of <br />the conditions of water quality at a larger number of sites and types than the data presented earlier. These <br />data were presented earlier in Table 2.04.7-3 which gives a listing of the site numbers, site type, and <br />conditions for 64 sampling stations on 9/19/79. Parameters measured were temperature (°C) and specific <br />conductivity (mmhos/cm). Natural variability within the permit and adjacent areas is, again, shown <br />between sites for a single sampling date. Further discussion of the effects of this variability and degree of <br />water quality impacts is given in the Hydrologic Consequence Section, 2.05. <br />Rule 2 Permits 2.04.7-22 Revision Date: 6/23/08 <br />Revision No.: MR-91