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RULE 2 - PERMITS <br />materials are described in Section 2.04.6, Geology Description. Based on analyses of coal, rool', <br />and floor samples. pI I values tend to be slightly to moderate]\- alkaline. overall sulfur content is <br />lo\\. and buffering capacity is relatively high due to the presence of significant quantities of <br />calcium. Consequently. acid - producing potential is lo\\. Similarly. chemical analyses indicate <br />to \\ concentrations of most potentially toxic Components. <br />n\ ailablc anal\ sis results for existing Seneca 11 spoils. \\hich have been in place a number of <br />\-tars alld have had ample opportullltN to weather and oxidize. offers all expanded and probabl} <br />more accurate perspective of potential water gllalit\ impacts than chemical analysis results for <br />IreSh coal. roof. and floor sainples. The weathered mine \\astt and coal refuse samples show no <br />sl`,unlflcant acid. alkaline. Or toxicity potentials. fill} Illlnor potential impacts due to IDS. iron. <br />or other chemical constitLICnts are expected to be minimized by speclllc operational measures <br />utilized dllrin`Ll Construction and reclannatloil of overburden and coal piles. These measures <br />include: <br />• Controlled placement and compaction <br />• Effective routing Of Surface drainage around stockpile areas <br />• Collection of disturbed -area runoff, in ditches. and treatment in sediment ponds <br />• Reclamation <br />It is anticipated that infiltration to the overburden and coal stockpiles \\ill be minimal given the <br />relative]v scull -arid conditions, compaction, and ellglnccringg controls that will be llllpltlllClltCd. <br />Slll'laCC I111101f is rOUted in diversion channels to sedimentation ponds \\-here It Is retained and <br />sampled prior to release to natural drainages. <br />As discussed above. PSCM \N ill utilize sedimentation ponds and associated drainage structures to <br />intercept and route 1'lllloff froin disturbed areas. retaiIl runoff 161- sediment control, and to control <br />discharges to stream drainages. Operation of the sedimentation ponds has the potential to affect <br />both -round water quantity and quality by altering the timing and volume of discharge flows. <br />providing additional recharge to alluvial ground water systems. causing changes in water <br />chemistry. increasing TDS levels through evaporation, decreasing TSS levels through settling. <br />and increasing the concentrations of specific mineral components through evaporation. <br />Effects of evaporation will be minimized by limiting detention time in the sedimentation <br />structures to that interval required for effective reduction of suspended solids. Because runoff <br />typically occurs only in response to snowmelt and major storm events, evaporation will be <br />further limited by cold temperatures during spring when the majority of snowmelt occurs. Pond <br />designs. as outlined in Exhibit 2.05.3 -E2, Drainage and Sediment Control Plan, provide for both <br />minimal detention times and effective pond routing so any delay in discharge to the receiving <br />drainages will be limited. With pond routing, discharge will occur continuously once the water <br />reaches the discharge elevation so effects on downstream flows or alluvial aquifers will likewise <br />be minimal. <br />Upon completion of alining, all mine disturbance areas will be reclaimed. Reclamation and <br />establishment of effective vegetative cover will minimize disturbed area runoff to the <br />sedimentation ponds, and result in restoration of natural drainage and direct discharge to the <br />receiving drainages once the non - permanent sedimentation ponds are removed at the end of the <br />extended liability period. Given this consideration, any potential ground water impacts will be <br />both limited in scope and of a temporary nature. <br />Midterm Review 2.05-iOl Revision 04/2013 <br />