Laserfiche WebLink
Squaw Gulch <br />Water quality was summarized for three wells and one shallow piezometer in Squaw <br />Gulch. The monitoring wells are designated SGMW -3A (diatreme), SGMW -3B <br />(alluvium/shallow diatreme), SGMW -5 (bedrock outside diatreme). The shallow <br />piezometer is screened in the alluvium and is designated SG -04PZ. Seasonal fluctuations <br />of water levels are seen in the piezometer and alluvial well of 3.4 to 7.8 feet bgs and <br />16.95 to 51.85 feet bgs, respectively. SGMW -5 has shown dry conditions since <br />installation. Ground water levels in SGMW -3A vary from 141.7 to 150 feet bgs and are <br />at the bottom of this well so that no water quality data can be collected. <br />Overall, the ground water in Squaw Gulch is characterized as calcium - sulfate dominated. <br />Data show a median pH value of 4.81 in the alluvium (SG- 04 -PZ) and a median pH value <br />of 5.88 in the shallow bedrock (SGMW -3B). Nitrates have median values of 4.31 mg /L- <br />N in the alluvium and 0.51 mg/L -N in the shallow bedrock. Sulfates have median values <br />of 423 mg/L in the alluvium and 595 mg /L in the shallow bedrock. Deeper ground water <br />quality data (SGMW -5 and SGMW -3A) are absent due to the dry conditions as a result of <br />historic drainage of the diatreme. <br />Grassy Valley <br />There have been 44 wells, four piezometers, and 16 boreholes monitored in the Grassy <br />Valley. This number includes additional piezometers and boreholes which were installed <br />in 2009 -2011 to expand the hydrogeological characterization in Grassy Valley. The <br />locations of the shallow piezometers, monitor wells, and boreholes are shown on Figure <br />2 -2 in Appendix 2 located in Volume II. <br />The ground water monitoring data for Grassy Valley has been divided into Upper Grassy <br />Valley, Middle Grassy Valley and Lower Grassy Valley based on the location relative to <br />the surface water monitoring sites. Upper Grassy Valley ground water monitoring sites <br />are located above GV -01 surface water monitoring site. Middle Grassy Valley ground <br />water monitoring sites are located between GV -01 and GV -03 surface water monitoring <br />sites. Lower Grassy Valley ground water monitoring sites are those sites located below <br />GV -03. <br />For Upper Grassy Valley there are four piezometers screened in shallow, <br />alluvial /colluvial materials in Upper Grassy Valley. These monitoring sites range in <br />depth from 19 to 40 feet bgs. Ground water levels in the alluvium are generally shallow at <br />9.83 to 37.18 feet below measuring point. There are six monitor wells screened in shallow <br />bedrock (defined as less than 200 feet in depth) in Upper Gassy Valley. Of these six <br />Cripple Creek & Victor Gold Mining Company <br />Cresson Project Mine Life Extension 2 <br />4 -16 <br />