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<br />dispersed seepage front. Thus, it is technically <br />infeasible to establish numeric effluent limitations for <br />the seepage front." <br />While we agree the alluvium is heterogeneous, we disagree with the conclusion <br />that the seepage front is so diffuse and dispersed that the CDPHE cannot identify <br />discrete locations for compliance. The applicant in both TR-26 and in the August <br />30, 1999 Technical Support Document, carefully points out that the contamination <br />from the West Pit is flowing through a "restricted zone" where the backfill <br />contacts the alluvium (see quote from page 3 of the Technical Support Document <br />above). The lateral extent of this restricted zone or "window" is carefully <br />mapped in Figure 3-4 of TR-26. The heterogeneity of the aquifer dictates that a <br />single monitor well is insufficient to chazacterize flow through the window, as is <br />proposed in TR-028. However, the window is narrow enough that a series of <br />wells in the window should be able to chazacterize the flow. This multiple well <br />monitoring approach is consistent with the monitoring program proposed in <br />Section 6.4.2.1 of TR-26. We recommend that the West Pit dschage through the <br />window be regulated under the permit, and be designated as Discharge Point 002. <br />Threshold level (compliance level) for specific pazameters in the groundwater <br />should be established and monitored in the existing TR-26 wells in and adjacent <br />to the "window". <br />Pazagraph 25 of the August 20, 1999 NOV/CDO makes reference to "...the seeps <br />into the Rito Seco, as described in paragraphs 13 and 14 above...." Paragraph 13 <br />of the NOV/CDO refers to one specific seep, while pazagraph 14 of the <br />NOV/CDO refers to three other seeps. We recommend that these specific seeps <br />be designated in the permit as Dischazge Points 003 through 006. Monitoring of <br />these seeps would be via the french drain/sump systems installed by BMRI last <br />yeaz. <br />Response: <br />Issues regarding the flow of groundwater from the West Pit into the Rito Seco <br />a]luvial aquifer fall under the jurisdiction of the Colorado Division of Minerals <br />and Geology (DMG) and have been addressed with the submission (Mazch 22, <br />1999) and approval (May 23, 2000) of Technical Revision (TR) 26. <br />The reviewers suggest that "a series of wells in the window" would be adequate to <br />chazacterize the flow of groundwater from the West Pit. The suggestion ignores <br />the current conditions wherein the flow of groundwater through the "window" has <br />been reversed as a result of the implementation of the TR-026 water management <br />plan. Thus, during the implementation period of the TR-026 water management <br />Battle Mountain Resa4rces. lnc. <br />8 <br />July 21, 1000 <br />