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2.05.6(6) <br /> The Operator will establish a minimum of two subsidence monitoring <br /> gridlines across the stream channel in areas of anticipated vertical <br /> displacement that will be surveyed prior to and following longwall mining <br /> beneath the area. These survey data will be used to confirm/refine the <br /> subsidence predictions for the area. (BLM Decision Record (DOI-BLM-CO- <br /> S050-2013-0010 EA)) <br /> The results of the subsidence monitoring programs and the results of the <br /> visual inspections for mass movement features will be submitted semi- <br /> annually for the reporting periods ending in June and December, within 30 <br /> days of the end of the reporting periods. <br /> The subsidence monitoring program will extend at least two years beyond <br /> cessation of mining in any area, consistent with the need for verification of <br /> the subsidence prediction. The DRMS must approve the cessation of <br /> subsidence monitoring through a technical revision. <br /> Mining has ceased in all areas of the mine effective February 26, 2016, over <br /> two years ago. The Operator has demonstrated the PL series subsidence <br /> monuments have been stable during the last two years and the 37 series <br /> monuments have been stable since they were installed. Subsidence <br /> monitoring performed to date has verified the subsidence prediction. <br /> Subsidence monitoring has ceased at the mine effective April 2018. No <br /> 2018 subsidence reports are required. <br /> (f)(vi) Map 14 & 14B, Mine Plans, present the location of the underground <br /> workings. Map 27, Subsidence shows the subsidence survey monument <br /> locations and the limited extraction zones for Pond P-1, Hubbard Creek, <br /> Terror Creek, Stevens Gulch and near the outcrop. The limited extraction <br /> zone near the outcrop is shown as the 110' overburden line. Mining in low <br /> overburden areas adjacent to the possible fault trace is explained in section <br /> (f)(ii)(B)• <br /> (vii) Map 14& 1413, Mine Plans, present the location of the underground workings <br /> including the size, configuration, and approximate location of pillars and <br /> entries and extraction ratios. Measures taken to prevent or minimize <br /> subsidence are presented on Maps 14, 14B and Map 27, Subsidence. <br /> TR-116 2.05- 172- 04/18 <br />