Laserfiche WebLink
Draft West Elk Mine 2005 Annual Hydrology Report 32 <br />• 4.3 Sedimentation Ponds <br />There are 7 sedimentation ponds (Map 2 and Figure 8) at the Project that are utilized to manage <br />mine water, storm water runoff, and wastewater treatment effluent. All of the ponds except MB-5 <br />and MB-3 are re lined to prevent seepage. There is also a "freshwater" pond (FW-1) that is used to <br />equalize diversions from the North Fork and provide storage. Pond FW-1 serves as the raw fresh <br />water supply for the mine's domestic water use and in-mine water needs. <br />In WI' =2095; three:poiids,disohagged"Waferto the h7grfh ~`ork,:ponds, NIB 1,(^ ac ft), M$-2R <br />_. <br />ac frj„aiid M$,4 ( ac-£t) Ponds:MB 3, MB=S IZPE, FW-1, and SG I, )?ad.nedlsoharge jn <br />~VY__2005.~?. Table 9 summarizes the water quality of all CDPS discharges, including <br />sedimentation pond (SG-1), for WY 2005. Table 10 shows the CDPS discharge permit parameters <br />and limits for the sedimentation ponds. Figure 8 illustrates the mine water balance including the <br />sedimentation pond dischazges. <br />Table 10 <br />Summary of Sedimentation Pond CDPS Discharge Permit Limits <br />u <br />Parameter and Time Period Sedimentation Pond <br /> Dischar a Limits <br />TSS (mg/1) <br />• 30-Day Average 35 <br />• 7-day average n.a. <br />• Maximum ~0 <br />TDS (mg/1) <br />• 30-Day Average n.a. <br />• 7-day average n.a, <br />• Maximum Report <br />Oil and Grease (1) <br />• 30-Day Average No Sheen <br />• 7-day average No Sheen <br />• Maximum No Sheen <br />Total Iron (mg/1) <br />• 30-Day Average 3.5 <br />• 7-day average n.a. <br />• Maximum ~~0 <br />pH (S.U.) <br />• 30-Day Average 6.5-9.0 <br />• 7-day average 6.5-9.0. <br />• Maximum 6.5-9.0 <br />I) No Sheen or less than 10 mg/1 <br />4.3.1 Ponds MB-1 and MB-2R <br />Pond MB-1 collects the Project's surface operations water and diverted storm water runoff. Water <br />from Pond MB-1 can be discharged into either the North Fork or Pond FW-1. Pond MB-2R <br />September 2006 HydroGeo, Inc. <br />