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West Elk Mine <br />documentation will provide a broader, more extensive view from which to associate or assess <br />landslide and other surface activity due to mining. <br />For the original F Seam and B Seam monitoring program, conventional ground surveying <br />techniques were applied for surveying the former monument grid, as shown on Map 29. The <br />surveys were designed to achieve horizontal accuracy's complying with the U.S. Department of <br />Commerce's "Second order, Class II" surveying standazds, and vertical accuracy's no less than 0.2 <br />feet. Grids were surveyed twice prior to the initiation of subsidence. A minimum of six <br />triangulation benchmazk monuments outside the azea of anticipated subsidence effects were selected <br />and established. Monitoring of the grid was discontinued in 1999. Subsidence monitoring reports <br />2.05-164 Revised June 1005 PR70, Rev. March 1006: May 1006 PR/D, Nov. 1006TR107 <br />