Laserfiche WebLink
<br />An artificial form of recharge Ss accurri ng as a result of the irrig atton ditch neMork and <br />practices in the immadlate vicinity of the nine. Nara there not Chfs source of reche rqe~ <br />the time required for the spoil to recharge frwa natural ground water flow and rainfall <br />would ba considerably longer, In eonelusS on, the mining oparati on will not diminish <br />vertical or horizontal permeabi liLf as and may increase them, Chus there should be m <br />significant impacts from the mining operation on ground rvater flan and recharge rates. <br />The time period required for the spoil aiateri al to rasaturate should be greatly seduced <br />because of all the irrigation recharge (the Nucls East area Hill be revegetated for an <br />irrigation type of posWining land use). <br />Containment of Pit Inflow Pumpaee and lmpaces on water 0uelity. All runoff and Dtt <br />pumpage from disturbed areas are routatl through sedimentation ponds. The ponds era <br />designed end constructed to impound runoff and ptt pumpage frao areas di aturbed by mining <br />and provide suffi ci enC resf dance time to insa re that the pond discharge water chemistry <br />• mea ES the effluent requf remente-apeeified in NPD75 Pe mast No. CO-DOOD213 (see Tab 7, <br />. Appendix 7-6). Plana have been developed for water rights augmentatt on pweping tram the <br />ponds and mi nTnizi ng cross on during the pumpf ng (pages t3-6 and 13-10 fn TaD 13 ). In <br />• total, seven NPDES ponds era or will be eonatrueted to contain runoff and pit pumpage from <br />the tno mS ni ng areas. Ponds 007 through 006 receive al,l runoff and pumpage from the Nuc1a <br />mi nt ng area and Pond 007 tc proposed to contain all di schargea from the Nucla East ni ni nq <br />area. To date, Ponds 002, OD3, 004 and 005 hove never df acharged. All flow data for Pond <br />001 can ba fount in Tab 7, Appendix 7-5. Appendix 7-7 of Tab 7 presents ell chemical data <br />for di schargas and monitoring at Ponds 001 and 006 as well as all florv data for 006. <br />A revs en of the chemical and floe data indlcaeea that the potential for any dS acharge Tram <br />Pond 007 to exceed state receiving stream or federal atandardc 1s very ni nt Hal. Through <br />1987, only one NPDES ctandard has been exceeded at Ponds OOl end 006. The ezcoedanee <br />occurred in 1982 at Pond 001. The measured 30 day average for T55 was 45 mg/1 and the <br />NPDEfi atantlard is 35 mg/l. Also, there has been only one exceadence of the Colorado <br />Department of Health races vi ng stream atandardc for Segment 5 of the San Niguel River. A <br />total recoverable value of 140 ug/1 far Nf was measured in the di acharge from Pant 001 and <br />the rsceivt ng stream standard is 100 ug/1. The si gniffeance of this is negligible ac <br />there is no Ni ataMard for Tuttle Draw, the associated flan was small and the impact to <br />Che higher flow San Nf gusl water qualify would not De meaaursbl e. <br />In the pit inflow section of Chia Tab, rates of ground Hater tnflow Dy year have been <br />ealeul atad, Tne highest rate of inflow is pra3ected to occur in year 5 of the Nucla Eagt <br />17-29 Revised OS/19/88 <br />• <br />REVISED MARCH 2006 Attachment 2.05.6(32-37 <br />