2008-01-15_PERMIT FILE - M2007044 (2)

Home Browse Search

10,000 gallons per day (gpd). When spread over the approximately 300,000 square feet of standing water, this amounts to an average percolation rate of 0.08-inch per day or about 2 to 3 feet per year (assuming an effective porosity of 30 percent for sandstone). Based on field reconnaissance conducted in 2007, no seeps were found at this geologic interval in Lumsden Canyon. However, seepage into the canyon could eventually occur after many years unless steps are taken to reduce inflows into the mine. Energy Fuels plans call for plugging the flows from the 10-Straight Shaft (3 gpm when last measured in 1994) and any historic drill holes with measurable flows. The 60-inch vent shaft that previously produced 0.4 gpm was backfilled by Umetco at the time of closure. The only other known significant source of ground water inflow is the water flowing into the Whirlwind Decline. A well permit and water right has been filed on this water, which will be used for mining activities during mine operations. At the time of closure, a bulkhead will be installed below the seepage to prevent this water from entering the mine. As discussed in Attachment A, the water seeping into the decline is from an unconfined perched aquifer and will backup behind the bulkhead only to the point where the water is entering the decline. Water quality within this pool is expected to remain relatively stable because it will not be in contact with the mineralized zone of the Salt Wash. Although it is probably impossible to completely eliminate ground water inflow into the mine, it does appear that the inflows can be reduced to levels more consistent with what may have existed prior to historic mining operations in the area. 19) The application materials do not contain any monitoring or mitigation plans for groundwater or surface water, with the exception of the water in the sediment pond. In that the proposed operation has the potential to negatively impact water quality in both surface and groundwater, the applicant should submit a monitoring plan to the Division for review and include a mitigation plan should the monitoring show impacts to water quality. Energy Fuels disagrees with the assertion that monitoring and mitigation outlined in the application is limited to water in the sedimentation pond. Exhibit T provides a monitoring plan for both surface and ground water. Details of the Colorado Discharge Permit System (CDPS) permit with the Water Quality Control Division were not available at the time the application was prepared, but these permit requirements can now be incorporated into both Exhibit T and the Stormwater Management Plan that will be submitted with other revisions to the application. A copy of our CDPS permit was previously submitted to DBMS. With the addition of the monitoring well discussed in Item 7 above, the monitoring and mitigation plans for those areas that could be impacted by mining activities include: Surface Water a. Water treated and discharged from the treatment plant is monitored weekly under the provisions of CDPS Permit Number CO-0047562. The monitoring results are reported monthly to WQCD. The treated water includes excess mine water and l:netg~- Duels 1Zesc~uri;e~; C'c~r~oraticm =14 1.:~nic~c~ 13cnllec-ar•cl, ~iUITt'. Ei0t? 15 L,tal:cw{:~~~tl. C`~::) $O l2$ I'hon~ :3(73-t~)74-2 ~1 ~0