2009-07-01_REPORT - C1980007 (6)

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West Elk Mine 2008 Annual Hydrology Report 16 monitoring data than the Lower Dry Fork flume since it isn't influenced by variations related to reservoir activities. Baseline monthly monitoring of the Minnesota Reservoir Flume began in the spring of 2006 and included measuring instantaneous flow, collecting field water quality data, and collecting samples for laboratory water quality analyses from April 2006 through October 2006 (CDMG, 2006). Routine monitoring (three times per year) at this location began in WY 2007. 3.1.4.3 South Prong Creek South Prong Creek is an ephemeral stream that is tributary to upper Minnesota Creek. The north fork of South Prong Creek drains the southern portion of the SOD mine plan area. The monitoring station on South Prong Creek is located at the mouth of the drainage and does not have a flume or data logger (Map 2). Preliminary flow and water quality data were collected during a one time sampling round of this site in 2005 (HydroGeo, 2006). Baseline monitoring is scheduled to resume in 2017, or at least one year prior to when mining begins in the area to monitor potential mining induced impacts. 3.1.5 Temperature Monitoring Sites The surface lands of the West Elk Mine are drained to the north by the North Fork of the Gunnison . River. Water from the mine water pumping facility (MWPF) discharge point enters the North Fork of the Gunnison River from Sylvester Gulch. In September, 2007, MCC contracted GEI Consultants (GEI) to install temperature loggers (a.k.a. thermistors) in Sylvester Gulch and in the North Fork of the Gunnison River in order to monitor the effect of discharge from Sylvester Gulch on the water temperature of the North Fork of the Gunnison River. Five temperature loggers (ONSET Corp. HOBO Water Temp Pro v2) were deployed within Sylvester Gulch, and three within the North Fork of the Gunnison River (Table 4). The loggers were installed by GEI on September 21, 2007 and were programmed to record temperature data at 15 minute intervals. Data from the temperature loggers are downloaded on-site monthly by HydroGeo (whenever snow/ice or dangerously high water levels do not prevent access to the loggers) using a laptop computer and an ONSET adapter cable. Each temperature logger was attached to a steel rebar rod using galvanized cable and stainless steel hose clamps. The rebar was driven into the streambed. In October, 2007 HydroGeo re-anchored each of the loggers to secure points on the shore using 1/16 inch aircraft grade galvanized steel cable. In the summer of 2008, each logger was reprogrammed to record temperature data at one- hour intervals, in order to increase the data logger battery life, and to increase the length of time it takes for the logger memory to become full and stop recording. The temperature logger sites were June 2009 HydroGeo, Inc.