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West Elk Mine The stream area near the confluence of Dry Fork and Deer Creek, within the area of influence of the west edge of longwalt panels E2 and E3, will be monitored prior to, during, and after mining. This is the area where the overburden thickness is at a minimum for the South of Divide mining area (350 to 400 feet) and subsidence effects (subsidence, tilt, and strain) are expected to be at a maximum. Survey monuments will be installed-roughly parallel to the long axes of longwall panels E2 and E3-along Dry Fork, neaz the Dry Fork road, where measurements can be efficiently made every two weeks when the longwall face is within the angle of draw. In order to obtain detailed data on subsidence pazameters in this stream valley environment, the monuments will be placed on 40- to 50-foot centers-roughly equal to one-tenth of the overburden thickness. Periodic measurements will document subsidence amount, tilt, and horizontal strain, which then will then be compazed with predicted values in Table 2 of Exhibit 60B. The flow in Dry Fork will be monitored upstream and downstream from this area of maximum mining effects in panels E2 and E3, in order to document any flow changes, and also compaze the results of field measurements with Mr. Dunrud's projections. Flow will be measured at three to four locations in the stream bed over each panel while mining is occurring within the angle of draw on a once every two week basis, assuming road and climatic conditions allow such monitoring. These measurements will be obtained using non-permanent, non-destructive devices such as flow meters or portable flumes or weirs. One flow monitoring location will be established upstream of the angle of draw of the panel being mined (E2 or E3), one or two within • the area of the panel, and another downstream of the panel outside the angle of draw. The biweekly flow monitoring will begin one month before the longwall advances to a point where the stream channel would be in the angle of draw of subsidence and continue for one month after the panel has advanced beyond the azea where the stream is within the angle of draw. After the month is complete, monitoring will occur once every quarter for one yeaz after mining of the longwall panel (E2 or E3) is complete. The thalweg of the Dry Fork will be surveyed over panels E2 and E3 beginning at a point downstream of the angle of draw of panel E2 and continue upstream to a point above the angle of draw of panel E3. This survey will completed before mining commences in the SOD and then remeasured upon completion of mining panel E2 and then again at the completion of mining E3. A final survey will be conducted approximately one yeaz after completion of mining E3 and subsidence within the azea of both panels is essentially complete. These flow and thalweg surveys will be used to determine if mitigation of the stream channel due to significant changes in flow or the stream profile due to subsidence aze warranted. Mitigation of mining impacts may be necessary if loss or diversion of flow or a significant change in the stream profile will significantly impact vegetation. Mitigation may require the sealing of fractures, if they occur in the stream channel with bentonite/soil mixes to stop water loss, excavating ridges or high azeas created by subsidence within the stream channel that impede flow, redirecting flow, if necessary, back into the original channel if diverted due to subsidence, and re-establishing riparian vegetation in areas negatively impacted by changes in flow locations. The appropriate permits will be obtained prior to performing mitigation activities. 2.05-l38 Revised November 2004 PRIO