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C. Sedimentation Ponds <br />There is one sedimentation pond at the mine, located between the portal bench azea and the office <br />facilities area, on the south side of the haul road. The pond treats runoff from the portal bench <br />disturbed area, the upper segment of the haul road surface and cut slopes, and a small supply <br />storage area. The pond is somewhat oversized (storage volume adequate to contain the sediment <br />and runoff from multiple 10 yeaz, 24 hour precipitation events below the level of the gated 8" <br />primary dischazge pipe). In addition to the primary discharge pipe, the pond has an open channel <br />emergency spillway designed for the 25-yeaz, 24-hour precipitation event. The sedimentation <br />pond is discussed in Section 2.4.4 of the text, and designs aze depicted on Figure 2.2-3. <br />D. Surface and Ground Water Monitoring <br />Information provided by the applicant with respect to ground water in the permit area can be found <br />in 4.2.2 through 4.2.4 of Volume I of the permit application. The monitoring plan is described in <br />Section 4.2.4, and monitoring parameters aze specified in Table 4.2-15. <br />As discussed in the Probable Hydrologic Consequences (PHC) section of this document, no <br />significant effects to bedrock or alluvial Bound water systems aze anticipated for this operation. <br />The applicant will conduct monitoring of ground water in a manner approved by the Division to <br />verify the projections of the PHC. The ground water monitoring plan is as follows (4.05.13(1)): <br />1. Quarterly monitoring of alluvial wells GW-1 and GW-3 for static water <br />level, pH, temperature, and specific conductance. <br />2. Water quality sampling of mine water dischazges as required by CDPS <br />permit. <br />3. Monitoring of all non-seep inflows into the mine to include source, <br />quantity, duration and quality (pH, electrical conductance, and <br />temperature). <br />4. Monitoring of quantities of water dischazged from the mine, consumed <br />in the mine, and imported for use in the mine. <br />Results of the quarterly ground water monitoring are submitted to We Division immediately after <br />data collection and analysis. Monitoring results and evaluation are submitted in an annual <br />hydrologic report (AHR). The AHR will detail inflows, dischazges and consumption of water <br />within the mine and shall be structured azound the normal "water yeaz" (October 1 through <br />September 30). The annual report will also include baseline water quality data in addition to the <br />quarterly monitoring data to allow for comparison of baseline and "during mining" conditions. No <br />specific due date for AHR submittal is specified in the permit application document, although the <br />AHR has generally been submitted in January. The following stipulation is included to specify a <br />due date for AHR submittal. <br />STIPULATION N0.26 <br />THE ANNIJAL HYDROLOGIC REPORT (AHR) COVERING THE <br />PREVIOUS WATER YEAR FOR THE MCCLANE CANYON MINE <br />15 <br />