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October 26, 20 10 C-1996-084/Lorencito Canyon Mine JRSe-? <br />- Fill 8 has also been completed. The fill was well vegetated and appeared to be stable at the time of the <br />inspection. There was some rilling and minor gullying on the face of Fill 8, mostly into the terrace ditches, but it <br />did not appear to be extensive. There was erosion and scouring in the east and west perimeter ditches, mainly <br />where the terrace ditches intercept the perimeter ditches. There is also major side-cutting of the west-side <br />perimeter ditch from the top of the fill almost all the way down to the confluence of the two perimeter ditches. <br />There is a 2-3 foot deep gully on the east side of the east perimeter ditch for Fill 8. There is also a 3-5 foot gully <br />entering the west-side perimeter ditch (from the west) just below the uppermost terrace ditch. There is erosion and <br />scouring at the confluence point of the two perimeter ditches. Given the fact that there is side-cutting in the west <br />perimeter ditch and gullying outside of the east perimeter ditch, Lorencito will need to get into the Fill 8 area and <br />repair these ditches. Lorencito should also consider armoring the confluence area of these ditches to help control <br />the erosion. <br />- Fill 9 has been completed. The fill is well vegetated and appeared to be stable at the time of the inspection. The <br />north-side perimeter drain was basically free of erosion until a point below the third terrace ditch and into Pond 9, <br />where there was some down-cutting, scouring and side-cutting. There was also some erosion into Pond 9A at the <br />confluence of the north and south perimeter ditches. The south perimeter ditch exhibited erosion in the form of <br />down-cutting and scouring pretty much its entire length. The problems were the worst at the intercept points with <br />the terrace ditches. Although most of the flow appeared to be confined to the perimeter ditches, Lorencito will <br />need to get into the Fill 9 area and repair the perimeter ditches. <br />HYDROLOGIC BALANCE - Rule 4.05 Drainage Control 4.05.1, 4.05.2, 4.05.3; Siltation Structures 4.05.5, <br />4.05.6; Discharge Structures 4.05.7, 4.05.10; Diversions 4.05.4; Effluent Limits 4.05.2; Ground Water <br />Monitoring 4.05.13; Surface Water Monitoring 4.05.13; Drainage - Acid and Toxic Materials 4.05.8; <br />Impoundments 4.05.6, 4.05.9; Stream Buffer Zones 4.05.18: <br />- Pond 6 contained water approximately three feet below the lowest weep hole on the riser pipe and was not <br />discharging at the time of the inspection. The pond embankment was well vegetated and appeared to be stable. <br />There are two gullies on the inlet side of Pond 6. One appears to be from a ditch that blew-out and the other is <br />where the ditch flows into the pond. These two areas need to be repaired. There is also an area that Lorencito has <br />used for riprap just to the south of Pond 6 that should be reclaimed. Finally, there was no trash rack or anti-vortex <br />device installed on the primary riser pipe for Pond 6. Lorencito will need to install these on the riser. <br />- Pond 7 contained water approximately three feet below the lowest weep hole and was not discharging at the time <br />of the inspection. The pond embankment was well vegetated and stable. There was some sediment at the inlet of <br />the pond but it was not possible to tell how much, since the sediment level marker was sitting on the pond <br />embankment. Lorencito will need to reinstall the sediment level marker (at the appropriate location and <br />elevation). There was some erosion at the pond inlet (from the north perimeter ditch of Fill 7). There was a gully <br />flowing into the pond between the two perimeter ditches for Fill 7 that will need to be repaired. Finally, there was <br />no trash rack or anti-vortex device installed on the primary riser pipe for Pond 7. Lorencito will need to install <br />these on the riser. <br />Pond 8 contained a small amount of water and was not discharging at the time of the inspection. The pond <br />embankment was well vegetated and appeared to be stable. There was a large amount of sediment in the pond. <br />While some of the sediment has been removed (there is a "hole" on the bottom of the pond where sediment has <br />Number of Partial Inspection this Fiscal Year: 3 <br />Number of Complete Inspections this Fiscal Year: 1 <br />Page 3 of 16