2024-11-22_REVISION - M1999120 (4)

Home Browse Search

Water Information(cont.) Exhibit G excess water in Little Dry Creek/Slate Ditch have caused an increase in ground water and flooding along that waterway. This is an example of how a trigger point is reached but not created by our activities. The remaining parcels that are not protected by a surface water body are agricultural lands with no structures within 200 feet. The mining operation will have minimal effect on the South Platte River in the form of minor groundwater depletions due to evaporation and water uses associated with mining. The depletions to the South Platte River, associated with mining, are currently mitigated with a DWR approved SWSP to prevent injury to vested senior water rights. The reclamation plan for the amended area will create 4 slurry wall sealed pits that will not be hydrologicly connected to the South Platte River alluvial aquifer. The south side of the Sandstead Phase is partially back filled and will be completely filled and reclaimed before being released. The other mining Phases actively being mined were sealed prior to mining, thereby eliminating ground water draw down typically associated with pit dewatering and the possibility of any adverse impacts to nearby alluvial wells. Potential Water Resource Impacts Ground Water Wells The amended Fort Lupton Sand and Gravel Mine will have minimal impacts on the prevailing hydrologic balance. Sand and gravel mining related impacts to ground water wells near the pit will be mitigated through the installation of slurry walls around the perimeter of new mining Phases prior to the start of dewatering these Phases (see ExHIBITD-MININGPLAN. Potential ground water depletions associated with the settling pond will be minimal due to the fact that they will be backfilled with wash fines. FIGuREG-1 is an updated list of wells from the office of the Division of Water Resources files, the wells (highlighted in blue) outside the permit area are not owned by L.G. Everist, Inc. Of the 40 wells within 200 feet of the permit area, L.G. Everist, Inc. owns 32 wells. Of the 8 remaining wells, not owned by L.G. Everist, 2 are deep wells (highlighted dark blue) and 6 are shallow wells drawing water from the surface aquifer (highlighted light blue) . The locations of the wells on the list are shown on EXHIBIT G-1 . L.G. Everist, Inc. , has 27 groundwater monitor wells on or around the permit area they monitor monthly for ground water levels. EXHIBIT G-2 shows the location of existing monitoring wells around the mine. Historic monitoring data is available for these wells. The applicant installed 4 additional ground water monitoring/water quality monitoring wells around the Northeast and Northwest Phases as part of the due diligence process when buying L.G.Everist, Inc. M-1999-120 Ft. Lupton Sand and Gravel November,2024 17