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<br />Mr. Michael R. Neumann <br />October 15, 1997 Page 3 <br />Surface water quality -LHG-1 <br />A long-term upward Vend is evident for the levels of total dissolved solids and sulfate in samples <br />from the downstream surface water monitoring site, LHG-1. From 1987 to 1996, the average <br />level of total dissolved solids has increased from approximately 1750 to 2100 mg/t (see attached <br />graph). Sulfate concentrations have shown a similaz increase from around 750 to 1100 mg/1. <br />Other parameters at LHG-1 (bicarbonate, sodium, calcium, magnesium, total suspended solids, <br />and acidity) have shown no general upward or downward trends during the 1987-1996 period. <br />The increasing levels of total dissolved solids and sulfate at LHG-1 parallel increases in those <br />two parameters in effluent from spoils spring RSP-4 which drains toward LHG-1 (see following <br />discussion of RSP-4).. <br />The water at LHG-1 is not suitable for agricultural or drinking supply use due to its high <br />chloride, sodium, and sulfate content. Pre-mining water quality data collected at this location on <br />May I5, 1977 found sulfate to be 850 mg/l, and sodium 56 mg/1(see Exhibits Volume II, <br />Exhibit CC). Flow was 0.03 cfs. Total dissolved solids averaged 1123 mg/l on the four days it <br />was sampled in 1977 and 1978. Although the pre-mining data is of limited extent, it appears that <br />mining has doubled the concentration of total dissolved solids, elevated sulfate levels by one- <br />third, and increased sodium levels several fold. <br />Surface water flow and quality -Spoil spring RSP-4 <br />Of the six spoils springs monitored, RSP-4 stands out because of its increasing rate of flow and <br />increasing chemical concentrations. RSP-4 is a water discharge point for the downdip end of the <br />spoils-filled pit. The spring is located at the top of the west wall of the pit. Chemical <br />concentrations of the water from this spring far exceed the concentrations of any other water <br />sampled in the pemtit area. Total dissolved solids in water from RSP-4 now exceeds 3000 mg/1, <br />and has been increasing; sulfate exceeds 1500 mg/1. RSP-4 drains directly into the stream bed of <br />Hayden Gulch. LHG-1 lies in the Hayden Gulch stream bed approximately 3300 feet <br />downsteam. RSP-4 appears to be the main contributor to the relatively high levels of sulfate and <br />total dissolved solids in water sampled at LHG-]. <br />Prior to mining, a natural spring, called SP-4 in the permit application, existed in the coal <br />outcrop mid-way between the cutrent location of RSP-4 and pond HG-8. Excavation of the pit <br />began there and progressed southward. Water sampled from SP-4 on 5/16/77 found total <br />dissolved solids of 1470 mg/1 and sulfate of 530 mg/I (see Volume VII of permit application, <br />Section 4, page 8, Table 1). Rate of flow was reported as "seep". The parameter concentrations <br />in that sample are similar to those now found in samples from the nearby spring RSP-2 although <br />RSP-2 flows from an elevation that is about 50 feet higher than the existing RSP-4 or the former <br />SP4. <br />The increasing rate of flow from RSP-4 may indicate that the reclaimed pit is nearly full of water <br />only I S yeazs afrer backfilling of the pit began (see map 2 in 1995 consolidation volume of <br />permit for reclamation sequence). In the Probable Hydrologic Consequences (PHC) section of <br />the permit application (Volume VII, Section 4, page 51), the operator calculated that it would <br />