PERMFILE104222 - Laserfiche WebLink

Home Browse Search

• PROTECTION OF HYDROLOGIC BALANCE As specifically requested, CYCC has updated the probable hydrologic consequence section as found here under the Protection of Hydrologic Balance. GROUNDWATER HYROLOGIC SYSTEM A detailed discussion of groundwater hydrology is presented under Section 779-15. The Eckman Park Mine permit area is located on the southwest flank of the Twentymile Park groundwater basin. The Twentymile Park Basin is an enclosed groundwater basin. As a result, any mining related impacts on the groundwater hydrologic system will be confined within the basin. Potential Mining Related Impacts on Groundwater Quantity and Quality The mining and related operations at the Eckman Park operation have the potential to locally affect the water levels, water chemistry and • dissolved solids concentrations of the groundwater contained in the Wadge overburden sequence, and the Trout Creek Sandstone aquifer. The Wadge overburden will be directly affected as a result of removal and replacement of overburden materials during extraction of the Wadge coal seam. The Trout Creek Sandstone aquifer may be indirectly affected due to a small proportion of recharge to this aquifer passing through over- lying disturbed materials. The major groundwater effects of the mining operation will be on water quality within the undisturbed Wadge overburden downdip of the operation. Recharge of these bedrock units through backfilled areas will result in significantly higher concentrations of dissolved solids and a change in water chemistry type. Typical basline TDS concentrations in the Wadge sequence average 600 mg/1 and the water type is a sodium bicarbonate type as shown by Permit Renewal Figure 3, Triangular Diagram Plot, Bedrock Groundwater. • This compares with a TDS concentration of about 4000 mg/1 in the backfill and a dominant calcium-magnesium-sulfate water quality type as shown by Permit Renewal 780-144-1