Laserfiche WebLink
III. COMMENTS -COMPLIANCE <br />Below are comments on the inspection. The comments include discussion of observations made <br />during the inspection. Comments also describe any enforcement actions taken during the inspection <br />and the facts or evidence supporting the enforcement action. <br />west, at the outlet end of the old 14" culvert and the new 18" culvert. #2590 is view to the east of the culvert inlet <br />where the breach occurred. #2591 is view to the south from breach location. <br />#2592 and #2593 show flow path from Breach #1 along ditch at toe of Topsoil Stockpile "K" SAE area that is <br />located across the road south of the breach location. The topsoil stockpile ditch turns to the east at the <br />southwest corner of the stockpile, and drains into a culvert with straw bale inlet protection at the permit <br />boundary. The culvert routes flow beneath a gravel county road along the south permit boundary. #2594 shows <br />the inlet of the culvert at the lower end of the soil stockpile ditch. The culvert inlet was partially blocked and will <br />need to be restored to design condition, with straw bale barrier replaced. Ditch segment along the flow path at <br />the toe of the stockpile was scoured along the upper segment and silted in from the ditch corner down to the <br />culvert inlet, and will need to be restored to design condition. #2595 is segment of stockpile toe ditch east of the <br />culvert inlet, which was not affected by the collection ditch breach. #2596 is another view of the CMP inlet at <br />lower end of the stockpile area SAE ditch, showing the minor sediment deposition across road and immediate <br />vicinity of the culvert outlet. <br />In summary, abatement at Breach #1 will need to include restoration of Pond 7 collection ditch to design <br />condition, restoration of Topsoil Stockpile "K" ditch segment to design condition, restoration of culvert <br />inlet and sediment check at lower end of Stockpile "K" ditch to design condition, and restoration of <br />affected county road ditches to design condition. <br />Breach #2a <br />Breach #2a and 2b occurred in close proximity along the same Pond 7 collection ditch, approximately <br />150 yards further west from Breach #1. Breach #2a was located furthest to the west and was viewed <br />first. There were no obstructions in the ditch at this location; it appeared that flow simply over-topped <br />the ditch and flowed out to the south. Ditch in vicinity of the breach was a wide grassy channel, <br />measured to be 7" deep and approximately 190" wide. The flow path was approximately SO feet wide, <br />and caused multiple short, closely spaced gullies 12"-14" deep along the toe of the slope immediately <br />south of the ditch, between the ditch and permit boundary fence at the toe of the slope. Sediment had <br />been deposited a foot or more deep at the toe of the slope along the permit boundary, and had silted in <br />the county road ditch at this location. Sediment had been deposited an inch or so thick across the <br />county road in a flow path 20 feet wide. The flow had entered an old diversion ditch immediately <br />south of the county road, which runs to the west. This ditch had evidently been constructed at some <br />point in the past to divert drainage away from city of Nucla sewage treatment ponds, which are located <br />further south. The ditch was a grassy channel where the mine runoff entered the ditch. <br />Approximately 100 yards down-gradient to the west, the ditch was grown over with dense willows and <br />cattails; there was no evidence of scour or deposition along the ditch segment observed. I did not <br />attempt to follow the ditch downstream through the dense growth. <br />Photo #2597 is the Breach #2a location. #2598 and #2599 are of the wide, shallow grassy ditch <br />channel at the breach location. #2600 is view to west along the permit boundary (the near Fence). Note <br />gullies at toe of slope to the right, deposition along fence, road ditch silted in, and sediment residue <br />across road. #2602 is same location. #2603 is the old diversion ditch immediately south of the county <br />road, which conveyed flow from the Breach #2a location. #2604 is the wetland vegetation downstream <br />on the old diversion. #2605 is a view down-gradient to the west along the old diversion, showing the <br />segment of the diversion between #2603 and #26041ocations. Note culverted crossing in foreground <br />4 <br />