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refer-ed to the CDPHE Colorado Discharge Monitoring Reports (DMRs) submitted monthly during the year for <br />additional information regarding specific discharge occurrences. Figures 128 through 131 provide graphical <br />representations of the 2002 flow rate and field conductivity data for Pond D at the Foidel Creek Mine and for <br />Pond E at the Fish Creek Tipple. Figure 132 depicts period of record total recoverable iron data for Pond E. <br />3.8 2002 Inflow Survev <br />The annual inflow survey was performed during early October 2002 (prior to freezing conditions). Water <br />elevations were monitored from the Fish Creek Borehole during the period of October 2001 to September 2002. <br />During the inflow study, flow rates and field parameters aze recorded for measurable inflows from the accessible <br />areas of the underground mine. Results of the 2002 survey are presented on Figure 134, 2002 Inflow Study <br />Mined Area. Longwall mining was completed in the EMD by eazly-January 2001. Production from the NMD, 12 <br />Rt Longwall Panel, was underway by late January 2001. The EMD was permanently sealed in October 2001 <br />removing all access to the 6 Rt and 7 Rt gate roads. The 12 R[ Longwall was completed in eazly September <br />2001, the 13 Rt Longwall was completed in June 2002, and the 14 Rt Longwall is anticipated to be completed in <br />May 2003. About 9800 feet of the 15 Rt gate road were developed by early October 2002, with a small portion <br />of the Northwest Mains extending past the neck of the 15Rt gate road. <br />During 2002, inflows continued in the Northeast Submains, although there appears to be a decrease in ceiling <br />dripping. The reported high flow value was approximately 15 - 20 gallons per minute, somewhat less than <br />• reported in 2001. The results aze presented on Figure 134. The field conductivity for the water was measured at <br />1494 umhos/cm, which is consistent with the 2001 measurement, Flows have historically been measured in <br />cross-cut 26 of the 6 Right Gateroad, however, 6 Rt was sealed in 2000. Thus, no measurements are available for <br />2002. Historical data is available in previous AHRs. The last flows measured for 2000 showed seasonal <br />variations, with an average annual flow of approximately 65 gpm (as presented on Table 77 of the 2000 AHR). <br />Inflows from the raise bore area (see IF 38 and IF 37 on Figure 134) were on the order of 30 gpm. Field <br />conductivity measurements varied from 1519 TO 1664 umhos/cm. <br />4.0 SUBSIDENCE IMPACTS <br />During the first half of 2002, subsidence survey data was collected periodically from established monuments on <br />the Union Pacific Railroad and the YVEA power line in azeas underlain by gate roads or panel centers during <br />periods of mining in the 13-Rt longwall panels. This data was presented to DMG in detail in the first of two <br />semiannual subsidence reports for 2002 (First Half 2002 Subsidence Survey Report). Data from [his report, as <br />well as earlier historical subsidence information is discussed below. As is reflected in the data and on the <br />enclosed subsidence map (Figure 137), the 13-Rt longwall panel did not directly undermine the Walcott, Hayden- <br />Gore Pass and Western Area Power Administration power lines, and Foidel Creek during the first half of 2002. <br />• Fish Creek: has been undermined and subsided by TCC's mining of the 13 Rt longwall panels. A post mining <br />survey of Fish Creek in areas underlain by the 13 Rt gate road or panel center was performed in July/August <br />2002. The final subsidence profile for Fish Creek over the 13 Rt panel is submitted as Figure 137 of this AHR. <br />14 <br />