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+. MINE ID ~ OR PROSPECTING ID / INSPECTION DATE 10-11-95 (Page 3) M-96-117 INSPECTOR'S INITIALS ACS Ae a result, the operator has been pumping Hazel-A water up to the tailing pond on a weekly basis:. The water level behind the bulkhead at the time of this inspection was just a few inche:e above the top of the tailing slimes deposited on the sill. The operator reported that during fine, windy weather, evaporation of water from the tailing pond amounted to about 2.5 inches per week. It was observed that the water level in the tailing pond was at approximately the same level as during the Division's 9/25/95 Bite inspection. There was very little precipitation at the Gold Hill Mill during the two weeks between the Division's 9/25/95 Bite inspection, and this 10/11/95 inspection. The prevailing weather during this two week period was sunny and breezy, which would be ideal for maximum evaporation. The qualitative observation that water inflow to the system was approximately equal to evaporative disposal during a two week period that was ideal for evaporative disposal, and was z~lso a period of minimum inflow, raises the concern that the net water balance under the currE:nt operating system will be positive, and potentially unmanageable as a zero discharge syetE:m. In order to further investigate the Bite water balance, the Division will require that water levels behind the Hazel-A Ad it be accurately tracked. The water levels behind the bulkhead, ae indicated by the existing staff gauge, along with the dates that the water level.e are recorded, must be reported to the Division. Minimum requirements for water level monitoring would be before and after each episode of pumping up to the tailing pond. Also, the operator should track the water level in the tailing pond by measuring the distance between the surface of the water, and the top of the standpipe closest to the mill building. In acldition, a general description of weather conditions at the mill between pumping episodes ehoul.d be included in the report. The operator should be prepared to provide a report on tailing pond and Hazel-A water levels to the Division each month on the monday preceding Mined Land Reclamation Board meetings, for at least the next 3 months. Aa ttre Division has indicated in previous reports and correspondence, a spray system at the pond may be required to enhance evaporation. A decision on whether and when installation of a epr•ay system will be required will be based partially on the results of the aforementioned water- level monitoring program. Other, more aggressive, water management options may have to bE: explored if the reeulta of the water level monitoring program indicate a significant net positive water balance for the site. In any case, it ie the goal of the Division, the operator, and the interested parties to assure that no further unpermitted discharges of proce:ea water from the Hazel-A Adit or from the tailing pond occur. Removal of Contaminated Soil PB #`4 listed in the Division's 8/26/95 inspection report requires removal and off-site disposal of contaminated soil from around the compressor and vacuum pump near the back of the mill building. This task ie to be accomplished by 11/1/95. The Solid Waste Section of the Hazardous Materials and Waste Management Division has imposed several requirements on the handling and disposal of the contaminated soil. These requirements are detailed in a letter from Steve Laudeman of the Solid Waste Section dated 9/15/95. One paragraph from that letter etate:s: It ie required that you notify the Division at least three (3) days prior to the waste removal taking place. A representative of this Division, the Division of Minerals and Geology, Boulder County Health Department, or the Town of Gold Hill will be present at the Gold Hill Mill when the waste removal occurs. I have subsequently spoken with Steve Laudeman about this requirement, and we agreed that the Division of Minerals and Geology would take the lead responsibility to assure that all of the contauninated soil ie removed from the mill site, and that the Hazardous Materials and Waste Manacement Division would take lead responsibility to assure that the contaminated soil ie propE:rly disposed of once it leaves the site. I do not need to be contacted to observe the actual excavation of the contaminated soil, but will investigate the site subsequent to the excavation to assure that the removal was complete and otherwise adequate.