2009-10-26_INSPECTION - C1980005

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Seneca I:I Mine. Phase I bond release, ,ng. 3_ 8 channel up from the "V-4 ditch" junction at 18%. One location downgrade of a turf reinforcement mat (TRM) segment between the "V-3 and 4 ditches" is still experiencing some scour due to very little vegetation. The location of a shrub test plot in the East Wadge Pit reclamation area contributes to this problem. The 50-foot segment of scour flows toward the edge of the channel and needs to be graded-out with riprap placed along the edge. The remainder of the PM-8 channel below the "V-4 ditch" junction appears to be stable, vegetation has established through the riprap, and we measured a representative slope at 18%. We walked the embankment for Pond 8 and determined that it is stable. The water discharging on the other side of the embankment was clear, and Mr. Mathews noted that any slope erosion that occurs could be repaired by handwork. The Solid Waste Disposal Facility was also inspected and we measured a representative slope of 16% on the valley headwall section of the area. We also measured a west-facing side slope of the upper PM-10 channel at 31%. The slope was stable with good vegetation. A freshly- installed TRM has been installed in the PM-10 channel which should address any erosion concerns, and we noticed grass growing in the shallow rills on the water shed. We measured a 45-foot channel segment of over-steepened slope on the lower end of the solid waste area at 23%. Mr. Mathews noted that this was probably okay, but TRM performance should be monitored by the permittee. The road ditch channel appeared to be stable and vegetation was growing; in the bottom of the channel. The PM:-12A channel, which controls runoff from the road, did not appear to present any long- term problems. We observed rilled access to the upper PM-12 channel where a 16% slope was measures. This area needs to be roughened or have water bars installed for stabilization purposes. We also measured a representative slope in the upper segment of the PM-12A channel at 21 %, and a slope measurement of 14% was recorded for the upper middle segment of the channel. Both segments have been stabilized with TRM and are well vegetated. Vegetation (yellow clover) was coming in better in the lower segment of the channel where a slope measurement of 18% was recorded. Although stable, the lower-most segment curves north rather than south and a design revision is needed. We walked the embankments for Ponds 2 (final pit impoundment) and 4 and determined that they were stable. The water discharging on the other side of both embankments was clear. We held a close out meeting July 14`h and Mr. Mathews did a thorough job of describing our observations and the problem areas noted above that need to be repaired prior to DRMS issuing a proposed Phase I bond release decision. Generally, the channels have been overbuilt so they are acceptable, and the recently repaired areas will need to be monitored. We emphasized that the scouring issues noted above for the 50-foot segment of the PM-8 channel between the "V-3 and 4 ditchers" and the lower 30-foot segment of the "V-3 ditch" that empties into the PM-8 channel need to be addressed by conducting additional grading and stabilization work/repair prior to DRMS issuing a proposed Phase I bond release decision. We also determined that several locations warranted additional monitoring. Specifically, some stabilization work is required for most of the "V-ditches" due to scarce vegetation. In addition, the permittee should monitor the