Laserfiche WebLink
PR-12 Exhibit 71 19 <br />4.3.1 Upper North Fork Drainage Basin Sui face Water Monitoring Stations <br />4.3.1.1 Deep Creek <br />Deep Creek is a perennial stream drainage that drains the Box Canyon mine panel area and the east side of the <br />SOD and West Flatiron areas. The Upper Deep Creek monitoring station is located up-gradient of the Box <br />Canyon mine panel area (mine panels 14 - 17 and 22 - 24) and the West Flatiron area. The Lower Deep Creek <br />monitoring station is located down-gradient of the SOD area and is directly east of the Box Canyon panels (Map <br />1). The flow monitoring at the Deep Creek monitoring sites was changed from continuous flow recording to <br />instantaneous recording three times a year in 2006. This change is being made for two reasons: mining in this <br />area is nearly complete and the Deep Creek stream channel is highly variable, resulting in continuous flow data <br />that are unreliable and do not represent actual conditions. <br />4.3.1.2 Box Canvon <br />Box Canyon is an ephemeral stream drainage. The upper reach of the drainage is typically dry and the lower <br />reach of the drainage only flows during storm events and during the spring months in above average precipitation <br />years. The Box Canyon monitoring station is located at the mouth of the drainage and was established to monitor <br />the area down-gradient of the Box Canyon panel area (Map 1). <br />4.3.1.3 North Fork Upper <br />The North Fork of the Gunnison River is a major perennial stream that drains the northern mine area. The North <br />Fork Upper monitoring station is located up-gradient of the WEM facilities area and up-gradient of the WEM <br />discharge points (Map 1). The underground mine water discharge flows into Sylvester Gulch then into the North <br />Fork of the Gunnison River. The mine surface water runoff is treated and routed to holding ponds and is then <br />discharged to the North Fork of the Gunnison River, if necessary. All of the WEM water discharge occurs <br />between the North Fork-Upper and North Fork Lower monitoring stations. <br />4.3.1.4 Syli,ester Gulch <br />Sylvester Gulch is an ephemeral stream that drains the north-central WEM area. All the active surface facilities <br />of the mine are located within the Sylvester Gulch drainage basin area including: the main road to the mine <br />facilities from Highway 133, the mine waste dump, the mine shop and offices, the mine portal, the mine <br />ventilation shafts, and the mine water discharge facility. The three monitoring sites in Sylvester Gulch: Upper, <br />Middle and Lower Sylvester Gulch (Map 1), are designed to monitor areas up-gradient of the mine surface <br />facilities area, areas down-gradient of the mine water discharge point and mine facilities, and areas down-gradient <br />of the mine spoils dump, respectively. The existing flume at the Upper Sylvester Gulch monitoring site was <br />replaced with a new Parshall flurne in August 2007. The Steven continuous recorder at the Middle Sylvester <br />monitoring station was replaced with a Global Water WL-16 continuous datalogger in March 2007. <br />September 2007 HrdroGeo, Inc.