2014-03-20_REPORT - M1977424 - Laserfiche WebLink

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Logan Wash Mine Annual Report Permit No.: M- 1977 -424 4.3 Daylight Bench Slope Stability Monitoring The Daylight Bench was constructed to support sealing of the Daylight Portal in 2004. Tension cracks and minor subsidence was first observed in 2009 on the small bench. Geo Smith Engineering has continued to survey the Daylight Bench for slope movement. Survey measurements began in May 2011 and have continued through 2013, access permitting. Surveys in 2013 were conducted on April 22, May 30, July 3, August 6, September 20, and October 18. Prior to the October, 2013 survey, no significant movement of the survey monuments was observed. The October 2013 survey noted that two of 5 extension stakes have shown minor to small (0.42 ft.) amounts of movement. Further measurements in 2014 will evaluate of there is a trend in this movement. Physical observations of the Daylight Bench do not indicate ongoing slope failure. 5.0 Maintenance Activities Maintenance activities included periodic inspections of mine roads, portals, mine water drainage systems associated with the retorts and general mine workings, as well as the inspection of Evaporation Pond facilities including the pond's security fencing, operation, and leak detection system. Maintenance activities conducted at the mine and Evaporation Pond are summarized in the following sections. 5.1 Mine Maintenance During the reporting period, inspections of the Logan Wash Mine site occurred on a weekly to monthly basis during April 2013 through February 2014. The upper mine facilities are usually not accessible from December through March due to deep snowpack and poor road conditions, but light snowpack in early winter allowed reasonable access by vehicle and on foot. Inspections focused on mine roads, headwalls, portal closures, bench surfaces, dump faces, constructed storm drainage and rip -rap channels. Mine water discharge rates and Evaporation Pond water levels were periodically monitored and recorded (Section 3.2). Road maintenance activities included grading of the running surface of the lower sparsely vegetated portions of the Lower Access Road, the Upper Access Road from the main Logan Wash Road to the Research Mine portal area, and the Evaporation Pond Road. The road maintenance also included the maintenance of stormwater runoff ditches and waterdips. 5.2 Evaporation Pond Maintenance Maintenance of the Evaporation Pond included inspection of (1) discharge rates to the pond from the mine retort plumbing system, (2) the leak detection vault, (3) wildlife security fence, (4) storm drainage ditches, and (5) general conditions of the pond, liner, and egress ladders. Repairs were conducted when needed. 6.0 Anticipated Reclamation in the Year 2014 Because the fate of mine water discharge is being assessed under Amendment No. 1, OOSI does not anticipate reclamation of any roads or disturbed surface areas at the mine site in 2014. Saplings that were planted on the mine dump faces will be assessed for overall health and mortality. No mechanical irrigation of these saplings is anticipated. Evaporation Pond maintenance will be conducted as needed. Roads not reclaimed will be maintained. Western Water & Land, Inc. 7