2015-01-26_REPORT - C1981020 (5)

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2014 AHR McClane & Munger Canyon Mines Page 5 Table 6 contains analyses of mine water discharged into East Salt Creek during October 2013. Groundwater Table 5 shows the results of groundwater sampling during the water year. Table 5a was created in 2011 for GW -10 to be used to gather a year of baseline data, however, GW 10 was sealed in 2012 since a large coal mine waste pile is no longer planned and therefore GW -10 is no longer required. Baseline data for Table 5 from the 1981 & 1986 monitoring is also shown. Baseline data for GW 9 for the period October 2007 through September 2008 is included. Results of quality sampling are consistent with the results from previous years. GW -4 was in close proximity to a hay field that is irrigated during dry periods and in danger of being eroded with an oxbow was replaced with GW 3. GW -3 is located adjacent to the road south of GW 4 and should be outside of the influence of the irrigation of the hay field. Refer to Figure 4.2 -2 of the McClane Canyon Permit. The Division of Reclamation, Mining and Safety has approved this substitution. Ground water wells GW -2, GW-4, GW -7, and GW -8 were sealed during 2007. Pond Discharges There was a significant precipitation event at the McClane Canyon Mine on September 9, 2014. Approximately 2.0 inches of rain fell in a 24 -hour period. One inch of rain fell in less than a one hour period. This extreme precipitation event overcame the sedimentation control system. The sediment pond filled with mud and water and water overflowed the emergency spillway. Water also flowed over the sediment pond's the north and west embankments. Additionally, water ran off the site in the ephemeral channels. There was no discharge from the Munger sediment pond during the water year. The McClane sediment pond discharged in September as a result of the above described precipitation event. The sediment fences at McClane, Munger Canyon and Loma were maintained as necessary. Discharge monitoring from the sediment ponds and mines are regulated by the Colorado Discharge Permit System Numbers CO- 0038342 (McClane) and COG - 850061 (Munger). Copies of Quarterly Discharge Monitoring Reports have been provided, under separate cover, to the DRMS at the same schedule required by the CDPS Permit. They are included in this report by reference. McClane Creek Temporary Diversion The Operator placed four wooden gabions in the McClane Creek channel during 1997 to ensure the channel would remain stable. The gabions were to provide a solid place in the channel bottom to limit any further erosion. In 2004 a re- survey was conducted and the data and inspection observations show there has been significant erosion subsequent to the 1997 gabion installation. Future high flow events may result in additional channel scour and side - cutting erosion. Portions