GENERAL40389 - Laserfiche WebLink

Home Browse Search

11 Post-m in ing/Post-reclamation: Upstream: Site 16 4/96-9/96 xflow=33.6 cfs 1996 xTDS=426 mg/L 1996 pH range: 7.8-8.5 Qualitya 996 x Ca= 69 mg/L 1996 x Fe=2514 ug/L Downstream Site 1002 4/96-9/96 xflow= 3 1996 pH range: 7.9-8.5 Quality:l996 >< Ca=74 mg/L 1996 R Fe=5096 ug/L 1996 z Mg=41 mg/L 1996 z Na=22 mg/L 1996 x Mn=93.4 ug/L i.0 cfs 1996 >< TDS=514 mg/L 1996 x Mg=47 mg/L 1996 x Na=164 mg/L 1996 x Mn=138 ug/L Additional inputs into Fish Creek between Sites 16 and ]002 include mine dewatering (NPDES permit No. CO-0042161, discharge no. OOIA) from the underground Foidel Creek Mine (C-82-056) which underlies the Mine No. 2 azea, and Mine No. 2 spoil springs. Mine water discharge from the Fish Creek Borehole ceased during the first quarter of 1996. Elevated iron levels at Site 1002 in 1996 were recorded in the early portion of the second quarter. The TDS concentration measured during the first quarter 1996 from the Fish Creek Borehole mine water discharge was 3295 mg/L, the mean calcium concentration was 113 mg/I„ and the magnesium concentration was 39.8 mg/L. No measure of sodium was recorded. Iron concentration in the Fish Creek Borehole discharge averaged 1,784 ug/L with Mn averaging 318 ug/L. A distinct decline in iron level at site 1002 was recorded for the remainder of 1996. The Mine No. 2 spoil springs consist of T (6862000), Q (6861700), R, M2-87, M293-1, M293-2, and two un-numbered spoil springs that report to permanent pond M. Spoil spring T is located at the north end of the western block, and drains approximately 375 feet to Fish Creek. Spoil springs Q, R, M2-87, M293-1 and M293-2 are located at the northeastern portion of the East Block, and drain to an un-named drainage before flowing approximately 3250 feet north to Fish Creek. Colorado Yampa Coal Company's sampling plan requires spoil spring water quality analysis when spoil spring flow exceeds 35 gpm during the Spring and Seep survey conducted in May of each year. Spoil spring Q, which discharges at the northern toe of the East Block slope was sampled for water quality. The following values were measured from Spoil spring Q in May 1996: Flow= 24.4 gpm, TDS=1330 mg/L, Ca=295 mg/L, Mg=99.5 mg/L, Na=23.4 mg/L, Fe=470 ug/L, and Mn=164 ug/L. Review of the summarized data in Table 1 show upstream and downstream TDS levels in Fish Creek have remained relatively consistent between pre-mining and post-reclamation condition. Downstream flow has more than doubled from pre-mining to post-reclamation for the two years compazed. Partial explanation for this increase in downstream flow in 1996 would be due to mine water discharge at the Fish Creek Borehole location from the underground Foidel Creek Mine. Upstream Site 16 demonstrates a marked increase in iron concentration from the 1979 data to [he 1996 data. Salinity components on calcium, magnesium and sodium have generally increased slightly both upstream and downstream of Mine No. 2 in the post reclamation condition. SAR values calculated from Ca, Mg, and Na concentrations remain low and not prohibitive to agricultural use.