2013-10-08_PERMIT FILE - C1982056A (2)

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When water level measurements are obtained for alluvial wells, the water level of the adjacent stream will also be determined using a staff gauge or other similar measuring device, except when snow and ice conditions preclude measurement. The staff gauges have been and will continue to be surveyed following installation, to assure an accurate assessment of stream elevation. Staff gauges will be surveyed at three -year intervals, beginning in 2000, unless physical damage renders the gauge unusable. Typically, surveys will be completed in the spring or early - summer, unless field conditions prevent access. During the late fall and winter months, snow and ice buildup on the streams or measuring devices may preclude accurate assessment of stream elevations. Consequently, stream water levels are generally measured during a period from late March/early -April through September. Water level measurement sites are listed on Table A, Hydrologic Monitoring Sites. For all wells, water levels will be measured using a standard level probe or pressure gauge before pumping or bailing of the monitoring well or allowing it to flow for period of time. Measurements will be made relative to a consistent datum, such as the top of the well casing. Wells will be pumped or bailed prior to water quality sampling to assure that standing water in the well bore is removed; and that representative field readings and water quality samples can be obtained. Surface Water, Effluent, and Spring Monitoring Monitoring Requirements - Surface water monitoring will document the quantity and quality of area stream -flows, discharge from sedimentation control ponds, mine water discharge, and the quantity and quality of springs. Monitoring sites and sampling frequencies are summarized by Table A, Hydrologic Monitoring Sites, and in NPDES /CDPS Permits CO- 0027154, CO- 0036684, CO- 0042161, COG - 850051, and COG - 850054. Site locations are shown on Map 13A, Hydrologic Monitoring Plan. Table A specifies two general categories relative to sampling frequency, "Regular" monitoring that is done continuously, and "Contingent" monitoring that is done only when there is a discharge from underground mine pumping. Actual timing of sampling may vary somewhat from Table A, due to weather and site ground conditions. NPDES /CDPS Permits Copies of the NPDES /CDPS permits are included in Exhibits 3 (Volume I11), 10 (Volume VIII), and 44 (Volume IIIA). Data from NPDES /CDPS discharge points will be included with the Annual Hydrologic Report. Copies of the Discharge Monitoring Report are also forwarded to DRMS. The NPDES /CDPS permits establish effluent limitations for discharges from the following four areas of the mine: a) Permit CO- 0027154 — Discharge associated with Ponds B, C, D, E, F, and T b) Permit CO- 0036684 —Discharge from Pond Eat the Fish Creek Tipple c) Permit CO- 0042161 — Mine water discharge at the Fish Creek Dewatering Facility d) Permit COG - 850051 - Discharge from the 6NM Shaft Facilities e) Permit COG - 850054 — Discharge from the 18LT Shaft Facilities USGS Stream Monitoring Stations - The USGS established continuous stream -flow monitoring stations along Foidel Creek. The USGS ceased monitoring these stations in 2000, and TC has continued monitoring two of these stations (Sites 800 and 900) as part of the ongoing monitoring program. Operation and maintenance of the two former USGS stations is anticipated to continue through the life of the mine. Rating Curves for Non -USGS Stream Flow Stations - Flow measurements will be determined from stage readings recorded for a transect at each station, and the corresponding rating curves. The rating curve for each station will be reviewed twice annually, once in the late- spring or early- summer, and once in the fall. If review indicates that stream configuration has changed significantly, TC may survey and generate a revised rating curve, or increase the frequency of stream -flow measurements. RN 12 -06 Exhibit 14 - 2 04/01/13