Laserfiche WebLink
3. Groundwater <br /> As described in the Brierley hydrologic analysis attached in Appendix 2, artesian conditions <br /> were observed in a lower area of the quarry floor during a site visit. The low permeability of both <br /> the basalt and the shale that surrounds it makes the source of the artesian conditions likely to be <br /> an internal water source (i.e. the uphill runoff pool). The artesian conditions are the only ground <br /> water encountered in the Ralston Quarry. <br /> Based on the analysis conducted by Brierley showing very low permeability, and the localized <br /> artesian conditions, the Ralston Quarry is considered a closed hydrologic system. It is anticipated <br /> that some water(-80 gallons a day) would be lost into the cracks of the basalt once the reservoir <br /> is filled to its anticipated final level, but this small amount will be dwarfed by the likely surface <br /> evaporation. <br /> The Brierley information found in Appendix 2 contains more detail on the hydrologic conditions <br /> in the Ralston Quarry. It is from a proprietary report produced for Asphalt Paving Co. as part of <br /> the reservoir analysis. <br /> The new Ground Engineering design for remedial slope stability employs a subsurface drain <br /> system that will daylight in the permit area and will be allowed to enter the rock filter designs as <br /> shown on Map C-4. This system will intercept some minor groundwater on the west facing <br /> slopes of the hogback where tailings were placed in the past. The quantities expected to flow in <br /> these drains should be intermittent and should flow in response to rainfall and snowmelt over <br /> some delayed period. The fairly close proximity of the shale to the surface limits the water <br /> capacity of the material atop of it in this area. <br /> 4. Irrigation Water <br /> The land within and surrounding the permit area is not irrigated. <br /> 5. 5. Water Consumption for the Operation <br /> The only water consumption for an operation like the Ralston Quarry is that needed for dust <br /> control and asphalt production. Dust control is needed both for disturbed surface areas as well as <br /> Ralston Quarry GrM 1. icki and Uwialra,PLLC <br /> January 2019 G-6 <br />