2010-02-01_REPORT - C1981020 - Laserfiche WebLink

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2009 ANNUAL HYDROLOGY REPORTS McClane Canyon Mine Permit No. C-1980-004 Munger Canyon Mine Permit No. C-1981-020 This report on the mine inflows, discharges and probable hydrologic consequences is submitted in compliance with the stipulations of the Mining and Reclamation permits for the mines noted above. The stipulations require a report for each permit. Since the mines are in close proximity, the effects are combined. The McClane Canyon mine was in operation during the year and Munger Canyon Mine has been reclaimed. This report shall first discuss the effect of McClane Canyon Mine on the hydrologic regime, next discuss the effect of Munger Canyon Mine, and then give an overview of the surface water system and groundwater monitoring. This report shall conclude with a discussion of the cumulative effect of both mines on the hydrology of East Salt Creek. McClane Canyon Mine Mine History and Production: The McClane Canyon Mine began production in 1977. The mine ceased production later that year when a fault was encountered. The mine remained idle until 1980. From 1977 through 1982 the mine produced a total of 184,365 tons of coal. In 1983 the mine was idled and remained under Division approved temporary cessation until November 1988. In December of 1988, 3,995 tons of coal was mined. In 1989; 125,200 tons of coal was produced. Production during 1990 totaled 208,945 tons. Production for 1991 totaled 194,000 tons of coal. 1992 Production was 7,914 tons. No coal was produced between 1993 and 1996. In 1997 production of 49,115 tons was accomplished. The mine was idle during 1998 and 1999. Production began again in February 2000 and has been continuous through the end date of this report. Production continued during 2009 with a production of 260,380 tons for the calendar year and a production of 304,610 for the water year. Production from the mine during the year involved mining and retreating 6th south panel. Production for the upcoming year will be driving and retreating 7`h'south panel. As required by stipulations, a mine map for McClane Canyon showing important hydrologic features is included as Figure 3. Seepage into the mine is nearly all from the areas mined to the north of the East Mains. Water from seeps accumulates in the east end of the East mains. The 2nd East Mains and panels driven to the south off of the 2nd east mains were virtually dry during 2009. In response to comments made by the Division regarding the 1995 annual hydrologic report, Figure I - Water Sampling Locations, is enclosed. Figure 1 is a line diagram of the drainages and water sampling locations that was derived from Figure 4.2-2 of the McClane Canyon Mine permit. Mine Water Inflow/Discharge. Appendix N of the permit application indicates the rate at which the saturated coal ribs are exposed should govern the maximum mine inflow rate. A five entry system exposes 1,480 lineal feet of rib per 100 feet of advance assuming 80 foot square pillars. That same 100 feet of development produces 5,400 tons of coal assuming an eight foot mining height. Based upon the k factor of 0.11 feet per day, it takes about one year to dewater an 80 foot square pillar (40 feet / 0.11 feet per day). Therefore, exposed coal ribs contribute to mine inflow for one year. At an annual production rate of 0.3 million tons per year, using this five entry system, a total of 5,500 feet of development would be required. This would expose 81,000 [(1,480)(5,500)/100] feet of rib. This amount of