Laserfiche WebLink
HYDROLOGIC CHARACTERIZATION AND MONITORING PLAN 11 <br />3.1 Shallow Sediments <br />Limited groundwater occurs in the alluvium, colluvium, and landslide deposits in the SOD and <br />DFL areas. The saturated alluvium in the SOD and DFL areas drainages (Dry Fork, Lick Creek, <br />Deep Creek, and the north fork of South Prong Creek) is too limited to be considered a viable <br />groundwater resource. <br />Two alluvial wells located in the SOD area were installed in the Dry Fork alluvium: the Upper <br />and Lower Dry Fork Alluvial wells. The depth of alluvium at these wells ranges from 23 feet at <br />the Lower Dry Fork Alluvial Well to 30 feet at the Upper Dry Fork Alluvial Well. The width of <br />the alluvial valley floor at both of these locations is less than 100 feet. Based on observations <br />during the drilling and development of these wells, the estimated hydraulic conductivity of the <br />alluvium is about 10-4 cm/sec (0.3 ft/day) (HydroGeo, 2003b). Monitoring data (water quality <br />and water level) have been collected from these wells since 2003. The locations of these wells <br />are shown on Plate I and a summary of the well completion data is shown on Table 3. <br />3.2 Bedrock <br />Even though groundwater occurs in numerous bedrock horizons in the region, including the <br />Rollins Sandstone, Bowie Sandstone, and Mesaverde Formation, aquifer tests indicate that the <br />water production potentials of these strata are low and they are not considered viable aquifers <br />(CDMG, 2005a). <br />One bedrock monitoring well (SOM-C-76) located in the SOD area is currently being monitored. <br />The well is installed in the F -Seam. A summary of the well characteristics is presented in Table <br />3 and the well location is shown on Plate 1. <br />3.2.1 F -Seam <br />Well SOM-C-76 is installed in the F -Seam and is currently being monitored. Based on test data <br />of well SOM-C-76, the calculated hydraulic conductivity of the F -Seam is 2x10-4 cm/sec (0.57 <br />ft/day). <br />Monitoring data have been collected from SOM-C-76 since 1978. The F -Seam groundwater <br />quality data indicate consistently high levels of TDS and iron (Table 4). <br />Revised 09/07- PRI 2; 08/16- TRI 39 HydroGeo, Inc. <br />