2013-09-25_INSPECTION - M2009076

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PERMIT #: M- 2009 -076 INSPECTOR'S INITIALS: MAC INSPECTION DATE: September 20, 2013 OBSERVATIONS The inspection was conducted by Michael Cunningham of the Division of Reclamation, Mining and Safety (Division). Ryan McHale of Venture Resources, Inc. was also present for the inspection. The Hukill Gulch Millsite is located approximately 2 miles north of Idaho Springs, in Clear Creek County. The site is permitted for 8.76 acres and the post- mining land use is rangeland. The inspection was conducted as part of the Division's regular monitoring program. The Hukill Gulch Millsite operates under a 110d Reclamation Permit. Weather conditions at the time of the inspection were dry; however, the surrounding area received record rainfall in the week preceding the inspection. The soils in the area were saturated; no surface runoff was observed. The permit sign was posted at the site entrance as required by Rule 3.1.12. Gen. Compliance With Mine Plan: The Hukill Gulch Mill site is comprised of two permit areas which include a mobile mill facility and a tailings impoundment. The mill is located above Hukill Gulch and consists of covered crusher feed pad, a crushing plant trailer, a crushed rock conveyor, crushed rock bin, ball mill feed conveyor, ball mill trailer, and flotation trailer. The mill site was not operational at the time of the inspection; according to Mr. McHale the mill was last operated in May of 2013. The mill site was in a neat and orderly condition; sediment fences were in good shape and were functioning properly. The ball mill trailer and flotation trailer were locked and no milling reagents were stored onsite. The Operator had processed approximately 200 tons of waste rock in 2013. The concentrates were produced using only gravity separation; future milling will include the flotation circuit. Hydrologic Balance: The waste rock which was processed in the mobile mill facility was taken from the existing waste rock pile located in Hukill Gulch; the waste rock pile contains approximately 8,000 tons of material. The Operator has constructed a lined tailings impoundment at the base of the waste rock pile. The tailings impoundment contains the tails from the 200 tons of waste rock which was processed earlier in the year. According to Mr. McHale, in the days immediately following the storm event the tailings impoundment had filled nearly to capacity with stormwater runoff. A concrete starter dyke forms the base of the impoundment and the Division observed water staining approximately 6 inches from the top of the concrete dyke; the tailings impoundment is to have a minimum of 1 ft. of freeboard at all times. Mr. McHale informed the Division that he used a portable pump to reduce the water level in the tailings impoundment. The water was pumped into the sediment basin which lies immediately below the tailings impoundment and was discharged from the sediment basin into Hukill Gulch. The sediment basin is sized for a 100 year /24 hour storm event, so there was likely little residence time in the sediment basin before the stormwater was discharged into the gulch. It is not known at this time how much water was discharged into Hukill Gulch. The Hukill Gulch Millsite is permitted as a zero discharge facility. The Operator has a stormwater discharge permit, which does not allow for the discharge of process water. The storm event which led to the tailings impoundment reaching capacity has been classified as a 1,000 year storm event. As such, the Division will not cite a problem for the unpermitted discharge into Hukill Gulch. The Operator's decision to pump the water from the impoundment into the gulch was done to protect dam from structural instability. During the inspection, the Division observed water flowing from the base of the waste rock pile which is located immediately upslope of the tailings impoundment. The water was pooling above the tailings Page 2 of 7