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<br />SECOND HALF 1999 SUBSIDENCE SURVEY REPORT <br />I. Survey Data: <br />During the second half of 1999, subsidence survey data was collected periodically from <br />established monuments on the Hayden-Gore Pass, Wolcott Tap-Wolcott (PSC) and <br />Western Area Power Administration power lines in areas underlain by gate roads or panel <br />centers during periods of mining in the 4 Right longwall panel. As is reflected in the data <br />and on the attached subsidence map, the 4-Right longwall panel did not directly <br />undermine the Union Pacific Railroad, Routt County Road No. 33 and Foidel Creek <br />during the second half of 1999. <br />The data and frequency for the survey monuments along the Wolcott Tap-Wolcott (PSC), <br />Western Area Power Administration and Hayden-Gore Pass power lines are presented in <br />the attached Table Nos. 1 tluough 6. <br />1l. Structures: <br />Structures affected during the second half 1999 reporting period include the Wolcott <br />Tap-Wolcott (PSC), Westem Area Power Administration and Hayden-Gore Pass power <br />lines. The Union Pacific Railroad, Routt County Road No. 33 and Foidel Creek were not <br />undermined during the second half of 1999. <br />Visual inspections of the Wolcott Tap-Wolcott (PSC), Westem Area Power <br />Administration and Hayden-Gore Pass power lines were conducted concurrent with the <br />surveys of the power poles from July 4, 1999 through January 18, 2000. No significant <br />damage to the structures was noted during this period. No repair work was required as a <br />result of TCC's mining activity. <br />Ill. Map: <br />The monitoring locations for the second half of 1999 aze shown on [he Second Half 1999, <br />Subsidence Map. The map also indicates the location of the longwall face on a monthly <br />basis. <br />IV. Conclusions: <br />Subsidence monument and power pole surveys disclosed no turusual developments <br />during [he reporting period. Subsidence magnitudes and projected draw angles were <br />within the anticipated ranges previously documented for the area. <br />Structures remained essentially unaffected during the period with the exception of the <br />predicted impacts to the power poles. No adverse impacts, i.e. inuninent failure of <br />structure, were evident with regard to these lines. <br />992ndHalfSubReport.doc Page I oft 02/01/00 <br />