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Hybo(ogic Data lnrnprcrariort and lmpacr A.ssessmrnr for the Pmnir and Adjacrnt Arear Table 7 Comparison a[ GP-l Baseline and 199? Sam pling Results, West Elk Mine Sampling pH Conduct. TDS Temp. Fe Mn Date Turbidity (units) (µmhos/cm) (mg/L) (°C) (mg/L) (mg/L) 08/OSBS 048 7.5 990 566.0 10.1 <0.02 0.21 08/08/85 048 7.5 990 526.0 10.0 <0.02 0.21 Du ( P 10/ 10/85 054 ! ; ~ I -- 693 870.0 7.5 <0.02 0.05 05/05('92 053' dpV 7.2 7•I 1130rS 750!~~~:- 10.0'i1,Z 99.7 ~..;.~ 0.61~.~ 06/04/92 056 C ~ 0 7.2' 7 ~ ~ 980' 7 11 746 ',: ' ~~ 12.1' ' J, 0 5.86 0.28 G O Z 09/08/92 ?' ~ q 3 7.2 ~ , } 1110 ~ 9 Y 562 G -! -~ ?' ;i „~ - ~ 248.0 ~ I 0.44 y Note: ' Field measurement. Others are labora[ory test results. • cubic yards of mine development waste, coal processing waste, and sediment pond cleanout material. In 1992 approximately 8,810 tons (9,837 cu. yd.) were placed in the lower refuse pile in the phase IV area. Table 7 shows the 1992 sampling results from monitoring well GP-I as well as baseline data from the well. The sample results indirate the 7 lower refuse pile is not impacting the groundwater zone near Sylvester Creek. Due to the low perme- t ability of the colluvial soil and the lack of a groundwater table near the surface in the colluvi- um (excep[ along the margin of Sylvester Creek), no significant future impacts to the groundwater regime are anticipated. Conductivity and TDS from samples of monitoring well GP-1 were closely monitored because values were slightly higher than the baseline samples. However, this may not be a continuing problem. September TDS values were within the range of baseline values. Refuse pile monitoring wells GP-3 through GP-5 remained dry throughout water year 1992. Also, there were no visible flows from the toe and mid- Concentrations of iron in the 1992 monitoring _' 1 samples were higher than in those identified during c, ~ baseline monitoring. This increase may be associat- ~ ed with the "B" development waste. Concentra- bons of iron in the 1993 samples will be observed to see if the elevated levels continue. section underdrain during water year 1992. Howev- er, pond MB~i collected surface runoff from the refuse pile, as well as any flows from the underdrain and can be considered representative of refuse pile conditions. Information on samples taken From MB-6 is presented in Table 5. The amount of refuse material placed in the lower refuse pile is highly dependant on conditions encountered in the mine. Projected refuse produc- [ion for 1993 from mining in the "B" seam and rehabilitation of the "F' seam belt entries is approximately 25,()00 tons. During 1992, water level in well GP-1 appeared [o correlate with flows in Sylvester Gulch. The water level rose during the spring and decrease during the summer (Figure 1). However, because no measurable water exists in the other GP wells, no piezometric surface exists in the area. Assessment of Springs A comparison of 1992 monitoring data with previous years shows no significant trends or changes which can be associated with mining activity. Most springs are responsive to spring runoff. but flow rates are sporadic and many times do not correlate well with other seasonal parame- terssuch as snowpack, precipitation, or streamflow.