Laserfiche WebLink
the iron concentration at the downstream river station has been increasing for the last 4 yeazs. <br />However, the December analyses do not show any trend and, in Fact, showuon concentrations that <br />are considerably lower than in June. Please comment on the 0.39 mg/1 value foruon and whether <br />or not a trend in increasing iron concentrations may be developing. <br />4. On page 2 of the 2003 AHR, it is stated that not enough water was in alluvial wells AA-1 and AA- <br />3 during December to conduct full suite analyses. This situation of not having enough water for a <br />full suite analysis has occurred in eazlier years as well. An examination of the average monthly <br />flows recorded at the USGS Somerset station on the North Fork of the Gunnison shows that <br />December is the third lowest month of the yeaz for river flow at that station. The Division suggests <br />that BCC sample AA-1 and AA-3 for the full suite analyses when the river flow is higher. Please <br />comment. <br />On the graph showing water elevations for AAl and AA3, the water elevation data for yeazs 2000 <br />through 2003 for alluvial well AA 1 aze missing. Please revise this graph. <br />6. In the Probable Hydrologic Consequences section on page 8 of the 2003 AHR, there is one value <br />used in the combined flow TDS calculation that may need to be revised. The TDS for the alluvial <br />flow is given as 2890 mg/I. As stated on page 8 of the 2003 AHR, this value was used because it <br />was the highest TDS value for alluvial well AA-1 for the period from 1987 through 1996. <br />However, since 2000, the TDS values for AA-1 have been closer to 3600 mg/1, as shown on the <br />graph of TDS for AA-1 and AA-3 in the 2003 AHR. In addition, the Probable Hydrologic <br />Consequences section ofthe 2003 AHR predicts that, with a TDS of 110 mg/I for the river, the <br />impact of the mine would increase the TDS up to 136 mg/l. But, the laboratory analysis for <br />December 2003 shows that the impact of the mine was greater, increasing the TDS in the river <br />from 110 mg/I to 160 mg/1. Please revise the calculation or explain why the currently used value is <br />appropriate. <br />If you have any questions, please let me know. <br />Sincerely, <br />~~ ~~°"' ~ <br />seph J. Du'dash <br />Environmental Protection Specialist <br />cc: Jim Stover (J.E. Stover & Associates) <br />Bill Bear (Bowie Resources) <br />c:\word\bear3\2003ahradegl <br />2 <br />