REP07148 - Laserfiche WebLink

Home Browse Search

Permit C-81-071 1996 Annual Hydrology Report • with measured data. At all sites, the inverse relationship between flow and field conductivity was evident. Water quality parameter values noted to occur outside of previously established ranges include the following. New maximum calcium, magnesium, and hardness values were established at site 302 in September (Table 27). New maximum total recoverable iron and mercury values were established at site 1002 in April and June respectively (Table 25). No new maximum or minimum values were noted to occur at site 16 (Table 24). The dissolved solids concentrations in the upstream station of Fish Creek (16) are generally slightly lower than those in the downstream station (1002). There is also a slight downstream trend of increasing sodium and sulfate concentrations while calcium, magnesium and bicarbonate concentrations remain fairly consistent. The proportionally higher sodium concentrations over calcium and magnesium leads to a slight downstream increase in SAR. These major ion changes are more apparent during the low-flow period. The increase in TDS could be caused to some extent by evapotransporative effects, but this would not account for the major ion changes. These changes are more likely attributable to discharges of waters having higher sodium and sulfate concentrations than the Fish Creek water. One source of such discharge is the spoil runoff and springs associated with Mine 2. However, the very low flows associated with the Mine 2 disturbed areas indicates minimal influence from this source. The primary source of such water used to be the Foidel Creek mine underground mine discharge point located near Mine 2. During 1996 however, flows from this site were insignificant and ceased in February of the water year. Trout Creek: Two surface flow monitoring sites on Trout Creek are utilized. Site 301 is located • on Trout Creek above the confluence with Middle Creek and site 69 is located on Trout Creek below the confluence. Required monitoring for these sites included monthly flew, field parameter, and water quality sampling during the irrigation season June through September. Site visitation and water quality sampling requirements were met at these sites during 1996. Tables 28 and 29 provide summaries of the 1996 Water Year data collected at Trout Creek surface flow sites. Tables 28a and 29a provide period of record statistical summaries of collected data at sites 301 and 69. Period of record flow summaries for these sites are provided as Tables 28b and 29b. Figures 56 through 63 provide graphical representations of water levels and selected water quality parameters recorded at each site. For the most part, typical patterns were observed although flow magnitudes were higher than those experienced over the past few years. Again, peak flow estimates were derived from extrapolated flow curves in some instances. The single identified water quality variance includes a new maximum pH recorded at site 69 in August. Since 1987, except for a short period during 1990, the salt content of Trout Creek below Middle Creek has been consistently higher than above Middle Creek. Typically, there is approximately 100 to 200 umhos/cm increase in field conductivity over this reach. The downstream increase was apparent during the spring runoff period. The Trout Creek salt content increases during the spring runoff. This is probably due to the effects of Middle Creek flows that have a higher salt content than Trout Creek primarily as a result of Foidel Creek which flows into Middle Creek just upgradient of the Trout Creek confluence. Foidel Creek salt loads during the spring runoff are primarily due to the impact of surface mine discharges. However, the Trout Creek salt content increase has not caused material damage, nor is there any increase in trace metal . levels I \DOCUMENTAHRIECKMAN\EP96TE%T.DOC 03/26/97 Page 8