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Valley to between 10-15 gpm. Granted the lower portion of the water shed will not be <br />impacted and as such one can't assume 0 flow. How would CC&V mitigate if the worst case <br />scenario takes place? What will happen to the entire Alluvial Valley Floor if the worst case <br />happens? Please discuss that possibility in detail and how CC&V will address the possible <br />impacts if it takes place. <br />F. DRMS has observed in the past 16 years some shallow alluvial flows that no longer flow <br />once the valley leach facility expanded. DRMS expects for example, when VLF 5 is <br />completed, drainage from AG-1 to dry up due to the placement of the valley leach in its <br />head waters. At present the drainage from AG-1 and the South under drain is pumped <br />back as make up water for the existing valley leach facility, but drainage from Grassy <br />Valley is utilized by down stream landowners,. As such, CC&V has to assume worst case <br />scenarios to satisfy long term impacts to the hydrologic balance. How does the shallow <br />piezometer water levels in the riparian area, correlate with the GW monitoring well's water <br />level for the wettest years? Does CC&V plan to install additional piezometers to monitor <br />water level elevation in the riparian areas? Please explain. <br />G. How come the water quality data from the DRMS compliance well labeled GVM-8A, is <br />slightly different from those ground water monitoring wells and other monitoring and <br />compliance wells located within the diaterme? Please explain <br />H. If The Grassy Valley is within the diatreme, the hydraulic gradient at depth is expected to <br />be essentially opposite to that of the shallow alluvium (Fig.4.9). It is difficult to comprehend <br />that all the infiltration will be captured by the deeper hydraulic gradient before being <br />transported down Grassy Valley and off site by the shallow gradients, especially since the <br />water management report indicates the rate of transmissivity to be higher in the alluvium <br />than in the deeper bed rock. This possibly could lead to metal loading to the Grassy Valley <br />alluvium and points down gradient. The proposed mitigation plan in the event of this <br />occurrence appears satisfactory. However, since CC&V is going to place a potentially <br />higher sulfur content overburden in ECOSA, the DRMS proposes all the additional <br />monitoring wells in the area in addition to the current compliance wells GVMW-8A &B be <br />considered as compliance wells, with the same reporting criteria as the current ground <br />water monitoring approved plan. In addition, one or two down gradient wells should be <br />added in both the shallow alluvium aquifer and the bed rock aquifer. It is not very clear <br />from the discussions in the water management report if the aquifers are perched or not? <br />Please explain. <br />1. The Division is aware that some of these monitoring wells will no longer be available when <br />the WHEX portion of the East Cresson is developed. The DRMS proposes to set numeric <br />protection levels on the ones to be in place even after the mine expansion is completed, <br />based on the current available data, which is more than five quarters. If after some years of <br />monitoring, the DRMS concludes impacts to the hydrologic balance to be minimal, CC&V <br />can submit a revision to the permit to lower the # of monitoring wells. Is CC&V going to <br />continue to monitor the surface water in Grassy Valley at locations GV-01 AND GV-02? <br />Given the operators own long term prediction that states in 50 years approximately 23gpm <br />could be discharged from the ECOSA, post closure, how would this discharge be addressed <br />if the predicted happens and the discharge does not meet the water quality standards for <br />Grassy Valley?. Since DRMS, does not have the statutory authority to bond for water <br />treatment, are there plans to obtain a NPDES discharge permit from CDPHEE at that time? <br />Please explain <br />10