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1 <br />Use of pre-mining data indicates that post mining runoff would be less than the pre-mining <br />' conditions. The delivery of nearly no sediment to the Sedimentation Trap A from the <br />reclaimed area is con5rmed by no noticeable collection of sediment in the trap. <br />' 4. FACILITIES (INDUSTRIAL) AREA <br />4.1 Area <br />The Facilities Area is bound on the north by the AVF, by roads to the south of Ditches 2S, <br />' 2S2a, 2S2b, and 2S2c to the east, and by the limits of disturbance along the southern <br />boundary of the Permit Area. The size of the facilities area is 7.00 acres. In the pre-mining <br />state, 0.24 acres are dirt road, the rest pasture. Ln the reclaimed state, 4.77 acres are <br />' revegetated disturbed land. The remaining 2.23 acres consists of gravel hardstands, buildings <br />and concrete pads. The Facilities Area is separated from Stollsteimer Creek by portions of <br />the Alluvial Valley Floor. <br />' 4.2 Nenvork and Configuration <br />' 4.2.1 Pre-Mining State <br />No large scale mapping or small contour interval mapping is available of the area that <br />' portrays pre-mined conditions. From the small scale mapping available, the facilities area <br />was apparently uninterrupted slopes from the upper reaches to the AVF area. A 500-foot- <br />long dirt road near the western-most portion extended from the highway down to the alluvial <br />valley door (USGS Chimney Rock 7.5 Minute Quadrangle). Runoff from the pre-mined <br />Facilities Area AVF likely discharged on to the alluvia] valley Y7oor meadows, eventually <br />reaching Stollsteimer Creek (to the northwest). In this demonstration, tlows are routed to <br />' the location of Sedimentation Trap A (inlet) by a portion of Ditch 1B and direct flow for <br />a comparison of pre-mined and reclaimed conditions. <br />' This demonstration first considers vegetation and ground cover information of the 1996 <br />Vegetation Survey of the Rangeland Reference Area as appropriate to the Facilities Area <br />' in apre-mining state. It then considers vegetation and ground cover information of Exhibit <br />5 as appropriate to the Facilities Area in apre-mining state. <br /> <br /> <br />4?.2 Reclaimed State <br />The area consists of facilities on a bench above the AVF, a road to the bench, and <br />subwatersheds above and below. The facilities bench area is left in a hardstand <br />configuration (gravel pads and concrete pads or buildings). After removal of Ditch 1B and <br />Sedimentation Trap A, runoff from the Facilities Area will migrate across the AVF, reaching <br />Stollsteimer Creek towards the northwest, similar to pre-mining conditions. <br />Vegetation and ground cover information was acquired by the 1996 Vegetation Survey. <br />Page 13 of 3~, 7 Oct 96 <br />