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MINE ID # OR PROSPECTING ID #: nn-~ 9~z_~tnn INSPECTION DATE: ~~ ~~ ~^e o~z INSPECTOR=S INITIALS: nrt~ OBSERVATIONS This was a normal monitoring inspection conducted by Tony Waldron and David Bird of DRMS along with Amy Thurlkill, Manager of Environmental, Health, and Safety for Cotter Corporation. The mine is located approximately 7 miles northwest of Golden, Colorado. The facilities are situated in a deeply dissected canyon valley of Ralston Creek. The primary orebody is generally located due south of the facilities location and was access by a series of horizontal drifts that lead to vertical shafts which descend into the mine. The weather at the time of inspection was unseasonably cool, cloudy, and humid. The last inspection conducted by DRMS at this site occurred on 6 December 2001. Most of the buildings and structures on site have been demolished or removed as part of the ongoing reclamation activities, with the exception of the shop, a 50-ft trailer used as an office, some storage tanks, and small buildings supporting weather stations, storm water containment, or other ongoing environmental monitoring. Operator has sealed several adits and shafts, and is in the process of installing a gate on the adjacent, 200-ft deep Black Forest adit portal. The reclaimed waste rock piles northwest of the mine facility are generally in good condition. With the exception of an erosional rill on one of the dumps, which we recommended repairing, the reclaimed piles appear stable with well- established revegetation consisting of Western Wheatgrass, Smooth Brome grass, Crested Wheatgrass and Orchard Gras. The slopes of the waste rock piles appear to have been reclaimed to the existing gradient of the piles upon cessation of mining. The slopes are relatively steep, but appear stable with no evidence of overgrazing and minimal erosion. A pile of rubbish about 50 ft across was noted on a bench, which Amy said would be removed and disposed of properly. The most pressing concern is the rising water level in the underground mine workings and the dissolved uranium concentration of the mine pool. The mine pool level is steadily rising and is reportedly 33.76 ft below the collar, the point at which it would breach the surface and potentially flow into perennial Ralston Creek, which flows into Ralston Reservoir, a drinking water source for the city of Arvada. The newly hired (February 2007) Ms. Thurlkill is quite concerned about the mine pool level, and estimates that only a couple months remain before the situation becomes critical. The concentration of uranium in the mine pool is 44.1 mg/L, versus a discharge target standard concentration of 0.76 mg/L. The drinking water MCL for uranium is 0.030 mg/L. Ms. Thurlkill noted that the rate of ground water inflow to the mine pool had not been determined, but that it was seasonal and was tapering off from rates observed in Spring. Cotter plans to hire Water Remediation Technology of Wheat Ridge to set up a 10 gpm pilot treatment plant on site within the next couple of weeks to test the feasibility of uranium removal from the mine pool. Based on the results of the pilot treatment plant, a larger capacity treatment plant, tentatively 200 gpm, will be set up. Long term remediation plans are not finalized, but include activity to cut off oxygen to the mine pool through sealing of mine portals and perhaps structural conduits that introduce oxygenated infiltration. It is hoped that the decreased oxygen influx that would result from this activity would induce reducing conditions that might favor attenuation of dissolved uranium. The Division raised the issue of a structural conduit for ground water flow and associated concerns of the potential for the structure to transmit untreated mine pool water to Ralston Creek. Ms. Thurlkill said that was among the issues that the Operator plans to look into in the near future. Inspection of the underground via the main adit was not possible due to high levels of radon emissions from the underground. Cotter has contracted with Frontier for mine closure activities. Frontier was on site and in the process of sealing the Black Forest adit portal at the time of the inspection. Among Frontier's duties will be to remove the substantial quantities of scrap metal from the site.