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12 (C) 7487.2 4468834.9 309431.3 40.620 7527.791 7535 -7.209 46+30 <br />The cross-section C-C' area appeared to be stable. There was no visible cracking or <br />settling observed in the backfilled and regraded area. There was some minor rilling in the <br />area but it does not appear to be a problem at this time. <br />- As well as taking data points along the Division's cross-sections, the Division also <br />walked all of the permanent drainage channels in the Seneca II-W South area (see <br />"Hydrologic Balance" below for more detailed information regarding these drainage <br />channels). This allowed the Division to cover the vast majority of the backfilled and <br />regarded areas in the Seneca II-W South area. The Division found the South area to be <br />well graded, with no signs of instability, including settling and cracking. There was <br />minor rilling in most of the regraded areas but these areas did not appear to be a problem <br />at this point. The one exception, as noted above, was in the PM-2 drainage area. There <br />was a major rill and gully area basically between permanent, post-mining drainage <br />channels PM-2A and PM-2D from approximately stock tank T-26 to stock tank T-27. <br />Seneca was in the process of finishing the repairs on this area at the time of the <br />inspection. Given the large extent of the rills and gullies in this area and the potential for <br />continued problems, the Division is considering excluding this area from the Partial <br />Phase I Bond Release SL-03 application. This possible exclusion area is shown on the <br />Division's Inspection Map 4. <br />Hydrologic Balance: - During the inspection the Division walked permanent, post- <br />mining drainage channels PM-1, PM-1A, PM-1B, PM-1C, PM-2, PM-2A, PM-2B, PM- <br />2C, PM-2D, PM-2E, PM-3, PM-3A and PM-6. The Division took elevation <br />measurements and channel width, depth and lining observations at random points along <br />each channel. The measured elevation points (corrected) were used to construct a <br />drainage channel profile for each channel, which was compared with both the as-built <br />channel profile (SL-03 Exhibit D) and the approved design profile (Exhibit 20-5.9, sheets <br />1 and 2). These channel profiles are shown at the end of this inspection report. <br />Additionally, the as-built channels' width, depth and lining were compared with the <br />approved designs contained in Tab 20, Exhibit 20-1. Finally, each channel's as-built <br />location was compared with its approved location, as shown on Exhibit 20-2, approved <br />with TR-59 (engineer certified 28 August 2007), as these are the locations that go with <br />the design profiles in Exhibit 20-5.9. <br />- The permanent drainage channel design locations versus as-built locations are shown on <br />Inspection Map 5, which is the portion of Exhibit 20-2 that shows the Seneca 11-W South <br />area. The location of the drainage channels along with the Division's elevation and <br />channel construction observation points are shown on Inspection Maps 6 and 7. The <br />following chart shows the design requirements versus the as-built measurements for the <br />permanent, post-mining drainage channels. <br /> <br />Channel <br />D width <br />D depth <br />D lining <br />D length <br />M width <br />M depth <br />M lining M <br />length <br /> <br /> <br />PM-1 <br />3 <br />0.7 <br />6 inch <br />1,528 <br />6-8 <br />3-5 9-18 <br />inch <br />1,416