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peak during spring runoff, which appears to be related to accelerated erosion effects. <br />Elevated iron concentrations seen at surface sites SW-14 and SW-15 in June of2003 (and <br />some alluvial wells) may have been the result of subsidence ponding and resultant <br />accumulation and leaching of iron-bearing sediments. These sites will continue to be <br />monitored for water quality, with any future anomalies noted. <br />V. Conclusions: <br />Structures remained essentially unaffected during the period with the exception of the <br />predicted impacts to the Union Pacific Railroad and Fish Creek. No adverse impacts, i.e. <br />imminent failure of structure, were evident with regazd to these structures. <br />Subsidence monument surveys disclosed no unusual developments during the reporting <br />period. Subsidence magnitudes and projected draw angles were within the anticipated <br />ranges previously documented for the azea. The angle of draw in the North Mining <br />District ranges between 17.5 to 19.5 degrees as follows; <br />1) Survey data over the 13-Right panel indicates the angle of draw to be <br />approximately 19.4 degrees in the vicinity where the railroad track crossed <br />the headgate entry. <br />2) Survey data indicated the angle of draw to be approximately 17.6 degrees for <br />the 14-Right panel in the vicinity where the railroad track crossed the headgate <br />entry. <br />3) Survey data over the 15-Right panel indicated the angle of draw to be <br />approximately 18.8 degrees in the vicinity where the railroad track crossed <br />the headgate entry. <br />4) Survey data over the 16-Right panel indicated the angle of draw to be <br />approximately 18.3 degees in the vicinity where the railroad track crossed <br />the headgate entry. <br />2004 hydrologic monitoring did not indicate significant impacts to Fish Creek. <br />2004_1 stHalfSubReport.doc Page 3 of 3 09/ 13/04 <br />