Laserfiche WebLink
. Total Dissolved Solids <br />Total Dissolved Solids (TDS) concentrations (Figure 6) in Trout Creek exhibit an expected pattern. As stream flow <br />' passes the mine, TDS levels increase while adjacent to [he mined areas and then begin [o decline downstream due [o inflow <br />from undisturbed lands below the active mine. Peak TDS levels in Trout Creek adjacent to [he mine occur in early spring <br />' prior to the period of peak flow. This is caused by the spring runoff from the portion of [he watershed in which [he Edna <br />Mine is located. Although TDS concentrations in [he mine runoff may be quite high when compared to concentrations <br />' occurting above [he mine, generally [he mine runoff is small relative [o Trout Creek's total flow. Therefore, a significant <br />increase in Trout Creek TDS levels is observed only during the initial stages of spring runoff. A comparison of the TDS and <br />Flow indicates that TDS concentrations appear to be directly related to Flow volume. <br />The dilution of TDS concentrations in downstream Flow for the past decade has not been as pronounced as in <br />previous decade. Beginning in 2990, mining and reclamation occurred in close proximity to TR-C. As such, dilution of TDS <br />' concentrations probably occurs farther downstream of TR-D as runoff from undisturbed areas enters into Trout Creek. <br />Although elevated TDS concentrations have moved downstream in conjunction with mining and reclamation activities, all <br />' values for TDS are consistent with [he probable hydrologic consequences projections. <br />' Calcium/Magnesium/Sodium <br />Calcium (Figure 7) is the dominant cation in Trout Creek with magnesium (Figure 8) and sodium (Figure 9) <br />occurring in lesser concentrations. While [he relative proportions of these parameters change slightly between the sampling <br />' points, all show peak concentrations coinciding with spring runoff, as would be expected. As with TDS, all three cations <br />show general increases in concentration as the water passes the mine area. Additionally, the relative proportion of each <br />' constituent remains constant to [he other constituents. While [rends in [heir subsequent dilution downstream have ye[ [o form <br />a consistent pattern, little or no dilution in any of the concentrations have occurted between sampling points TR-C and TR-D <br />' since 1989. For 1991-2001, i[ is believed [ha[ [his was due in part to [he Moffat area mining and reclamation activities and, as <br />such, the pattern is anticipated to continue. However, since [his occurrence existed prior to the initiation of Moffat mining <br />activity, [he trend may also suggest [hat inflow from undisturbed azeas upstream and downstream of TR-C contains <br />approximately the same concentrations of these parameters as runoff from the mine. <br />9 <br />