Laserfiche WebLink
<br />' Moffat area, the 1990-1992 trends showing peak sulfate levels at TR-C and TR-D <br /> are expected to continue. while peak levels may be shifting downstream, they <br />' do not seem to be increasing and it is believed that an equalization in the <br /> sulfate-bicarbonate balance occur s downstream as the source of the sulfate <br />1 (mined areas) is unavailable and dilution by runoff from undisturbed areas is <br /> introduced. <br /> Total Suspended Solids <br />Since 1983, Total Suspended Solids (TSS) levels show a general continuing <br />1 decrease in concentration (Figure 5). Periodically, this general pattern is <br />interrupted, as occurred in 1984 and 1988. As previously discussed, the <br />flooding which occurred in 1984 caused some rather dramatic changes to the <br />stream channel and increasing TSS levels. The TSS values obtained since 1988 <br />' suggest that the reaches along Trout Creek that were affected during the high <br />flows of 1984 have again stabilized with TSS values being consistent with <br />values obtained during baseline sampling. The samples taken in late May of <br />1988 suggest some bank caving may still have been occurring during peak flow <br />periods in the spring. This is indicated by a substantial increase of TSS <br />values occurring at TR-C and TR-D when compared to the other upstream sampling <br />stations. <br />1 Manganese <br />Manganese (Figure 5) shows fairly consistent values since the fall of 1981, <br />except during 1984. At that time, a dramatic increase occurred upstream of TR- <br />A with significant dilution being observed at each successive monitoring point <br />' along the mine area. The dilution was caused by the low concentrations <br />present in water exiting from the mine vicinity. All the manganese values <br />' observed, except May, 1989, are consistent with the baseline values. The <br />relatively high values of manganese observed at TR-C (0.13 mg/1) and TR-D <br />' (0.16 mg/1) during May of 1988 did not appear to be related to mining activity <br />as an elevated concentration was not observed at TR-B (0.04 mg/1) which is <br />immediately downstream of the active mine. <br /> <br />10 <br />r <br /> <br />