2007-08-29_REVISION - M1980047 (2)

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Crlony Snare Oi~ Pm;ect. Grnoraoo M1'LRO Penh A1-rf.A47 Rev Aug 24, 2007 2UU6 Attocto0 Area Status Surr•.ma~y .inn Requasl Icr RaOUCppn in AflecleC Apfeaae 4.2 Resource Block Reclaimed Areas 4.2 t Mine Bench This area conssts of 56 acres, of which 27 acres are the flat surface of the m!ne bench and 4 acres are an access roadway along the west edge of the bench to the mine s vent portal site (A-groovy road) The remaining 25 acres are comprised of 14 acres of finished vertical benched rock cuts on the east side of the bench and it arses of a 1 75'1 rockfiu slope or. the south face of the bench (The vertical benched rock ruts on thc' writ slCe of the Mma Bench are included wdhm the Plant Access Road, Area 19C, and are discusseq :aterl. The approximate limits of the area are shown on Exhibit F-3, and post-m:ning topoyraphy (current topography) is shown on Exhibit F--t The current condition of the areas is presented nn Figures 24 (p 21), 43 and 44 (p, 33). Limits of the areas that will remain active affected acreage after approval of this plan are depicted on Exhibd F-11. The 27 acre Ilat surface of the Mine Bench and the 4 acre A-groove Road (Sub-area 6Ai remain active areas. The remaining cliff faces and the 1 75:1 sloping rockfill face, adding up to 25 acres were !n their fins! !orm as of completion of constructon, as descntred ~n Exhibit E of the original March 1980 permit appl~cahon (p.E-•591. Accordingly 25 acres of Area 6 are requested for rema~at from the affected area on the basis that these meet the approved reclamation plan. 2.2 Upper Middle Fork (ISP Area 7) This area consists of 77 acres immediately around and upstream of the Middle Fork Dam. which was constructed in 198». The approximate limas of the area ere tlepicteC on Exhibd F-3 The reservoir surface is approximate:y 5 acres. ano the affected land area around the reservoir ~s 72 acres. Post-mining reclamation plays consisted of reclaiming construction areas associatetl with the completed roller-compacted concrete (RCC) dam and reclaiming borrow areas opened up, but never useC, for the originally Ces;gned earth and rockfP embankment tlam design Approximate post-mining topography s depicted on Exhibd F-4 Llmds of ilia areas that will remain active affected acreage after approval of this plan are depicted on Ezhibd F•1 t. Current condaions in the area are depicted m Figures :through 9 bebw. The possibility of the qam and reservoir trecom~ny permanent post-mining water resource assets was clearly considereC in the reclamation plan submitted with the onginal March 1980 perma application (Exhlbd E, p E-»8) With respect to other construction related disturbance, this redamatwn plan tailed for topsoil to be useC in regraded areas where practical, ano for other exposed valley slopes to be stabilized to the extent possible, recogrozmg that rock slopes would not be amenable to lopsoding In Upper Middle Fork. the change to the RCC design m 1982 resulletl m a greatly reduced construction disturbance impact This tlisturbed area reduction occuretl because the volume of the concrete dam was about 20°'~ that of the previous embankment qam, and most Cf the aggregate needed for the concrete was already avacable in the form Cf marlstone ewsting on the Mine Bench 'i; mile to the south. Areas that had bean stnppetl of vegetation ir. preparation to open borrow sources had not yet been stripped of topsoil ', herefore, upor. completion of construction of the concrete dam, all that was required in most of these areas was to re-seed the areas with the permanent seed m:x apprdveC for this site. Examples of this treatment are presented m Figures 8 and 9 Other areas that had already been opened to expose rock faces to become yuarnes for the rockfUl ponicns of the previous embankment design were already m their final form with vertcal rock faces. This area is visble in Figures 6 and 7, including the 2,1 regraded zone uelow the cbfts that was amenable to stabdizabon by permanent revegetahon, which was pone n t 586.