_INSPECTION - C1982057 (81) - Laserfiche WebLink

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July 21, 2011 C-1982-057/Seneca II-W Mine SLB channels PM-2, -2A, -213, and-3, in the Pond 016 drainage area,were all in need of repair. Downcutting as much as 4'had occurred in some sections. Most of the turf reinforcement mat(TRM)and rip rap had washed down into the surge ponds, and some TRM and rip rap had gone through the J-2 culverts and into Pond 016A. PM-1, in the Pond 017 drainage was also damaged. Flow had overtopped the T-25 stock pond,carrying TRM and rip rap to the inlet of Pond 017. The operator was encouraged to redesign and rebuild the south area drainages for an event in excess of the required 10-year, 24-hour event. Suggestions offered included increasing the number of surge structures and improving the installation of rip rap to include a range of graded material with an average size of the prescribed D50 so that flow will not work its way around the rip rap. It is also recommended that rip rap be durable,angular,denser rock that will not float. ROADS—Rule 4.03 ❑Construction 4.03.1(3)/4.03.2(3) ❑Drainage 4.03.1(4)/4.03.2(4) ❑Surfacing and Maintenance4.03.1(5)and(6)/4.03.2(5)and(6) ❑Reclamation 4.03.1(7)/4.03.2(7): The operator was working on reclaiming,to the postmining width,the Mine Entrance Haul Road,Haul Road A, and the dragline pad at Road J. The majority of the grading was complete,with the exception of the section of Road A between the facilities area and Pond 006. Topsoil was being replaced on the regraded areas. Road G road surface and ditches were in good condition. LU-1 was slightly rilled due to recent storms; the operator should monitor this and maintain as necessary. Reclamation of LU-2 was underway; material had been pulled up from the fill slope against the cut slope. It was apparent that the replaced material had been compacted. RE VEGETATION—Rule 4.15 ❑Vegetative Cover; Timing.- There was a patch of Cheatgrass and Japanese brome on the north side of Haul road G adjacent to Pond 005. Houndstongue and thistle had been sprayed along Haul Road G and on the Pond 005 embankment. There was a large gully in this area and another at the former topsoil stockpile location(Q)further east. Neither of these was listed in the annual rill and gully survey for 2011 but should be included in the planned repairs to be completed before November 1, 2011. The reclamation area above T18 (draining to 005 Gulch)was inspected. Vegetation in this area is good,with a considerable shrub component(sage brush, snowberry and serviceberry). Weed spraying had occurred in this area,but there were a couple of patches of healthy thistle observed. A gully(about 8"deep and 40' long)was observed 20' to the north side of and parallel to the main 005 Gulch channel; SCC should monitor this gully and repair it if it worsens. Reclamation in the 006 Gulch was in good condition and progressing nicely. The operator had sprayed a large area of Curly dock in the upper part of the drainage. This area should also be sprayed for thistle and houndstongue. Number of Partial Inspection this Fiscal Year: 1 Number of Complete Inspections this Fiscal Year: 0 Page 3 of 8