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September 15, 2020 C-1981-025/North Thompson Creek Mine RDZ <br />The following ponds were inspected: the Long Pond, Treatment Pond T-1, Treatment Pond T-2, the Polishing <br />Pond (Pond P-9), and the Refuse Pond. All but the Refuse Pond were discharging. At the upper end of the <br />treatment system, orange precipitate was visible, indicating iron in the water. The water discharging from Pond 9 <br />was relatively clear, with no mineral staining or odor. The flow through the ponds appeared to be approximately <br />the same at the upper end (pipe from mine above the Long Pond) and out of Pond 9. The flow also appeared to be <br />similar to the flow during previous inspections. No problems were identified with the ponds, although the amount <br />of biomass in some of the ponds is significant, and this material may need to be removed in the next couple years <br />to assure proper functioning of the pond treatment system. <br />No problems were identified with most channels between the ponds or the aeration ditch above the Long Pond. <br />(An exception is described below.) At the outlet to Pond P-9, the diversion of discharge to the Refuse Pond <br />(performed as a result of a violation in 2014) is functioning well, and there was no discharge to the creek (Outfall <br />01). The old channel out of Pond T-2 (with a pipe spillway) was diy; discharge from Pond T-2 flows directly to <br />Pond P-9. <br />The ditch into the Refuse Pond (from Pond 9) was not functioning. Water was flowing over a breach in the berm <br />and into the wooded area adjacent to the mine site. This was approximately 100 feet west of the Refuse Pond. The <br />source of the problem appeared to be a buildup of sediment and vegetation in the channel. The water was <br />infiltrating before reaching North Thompson Creek. Rob Zuber notified Jim Stover of this problem after the <br />inspection on September 15. Rob returned to the site on September 17, and the problem was fixed. Sediment and <br />vegetation had been removed from the ditch, the berm had been built-up, and water was flowing to the Refuse <br />Pond. However, this channel has other reaches where this same issue could happen in the future. It is <br />recommended that this ditch be cleared of sediment and/or vegetation to prevent more breaches. <br />SIGNS AND MARKERS — Rule 4.02: <br />Stream buffer signs were seen between the ponds and North Thompson Creek. Entrance signs were in place. <br />DOCUMENTS RECEIVED - none <br />OTHER (SPECIFY) — none <br />ENFORCEMENT ACTIONS/COMPLIANCE <br />No enforcement actions were initiated as a result of this inspection, nor are any pending. <br />Number of Partial Inspection this Fiscal Year: 0 <br />Number of Complete Inspections this Fiscal Year: 1 <br />Page 3 of 7 <br />