Laserfiche WebLink
<br />COMMENT 4. The use of the ertent of plumes at twenty years to justify the adequacy of <br />a monitoring network that could be eliminated some 9-1'S years after the <br />initiation of active operations, i. e. 7-10 years of mining and 2-S years of <br />reclamation, seems incompatible. <br />BMG should provide plots of appropriate contaminant plumes, using <br />discharge points which include that which was mentioned under 1J, at <br />times of 9 and IS years in order to better illustrate the adequacy of the <br />monitoring network. <br />RESPONSE: We have rerun our contaminant transport model for time periods of 9 <br />years and IS years with the same source strength of 2.5 lbs/day. <br />The porosity sensitivity analysis for a time frame of 9 years is presented <br />in Figure 6, while the dispersivity sensitivity analysis is presented in <br />Figure 7. <br />Likewise, for a time frame of 15 years, the porosity setsitivity analysis <br />is presented in Figure 8, while the dispersivity sensitivity analysis is <br />presented in Figure 9. <br />For each of these analyses, the source is assumed to be in the southwest <br />part of the collection pond (as the Division requested in comment No. 4) <br />and they all show that well M-9 can detect movement of a hypothetical <br />contaminant plume from this location. <br />-3- <br />