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.,T ~_ (Page 2) MINE ID ~ OR PROSPECTING ID # M-7T-493 INSPECTION DATE IO-17-94 INSPECTOR'S INITIALS ACS OBSERVATIONS A monitoring inspection was conducted of Climax Mine underground workings, specifically the 600 level. The operator proposes to relocate the dewatering pump station resulting in flooding of the level. The purpose of this inspection was to gain a better understanding of the potential for environmental impacts resulting from flooding of the 600 level. The new dewatering pump station location will be at.#5 Shaft; 80 feet below the shaft collar elevation. The operator has indicated that this dewatering horizon is below the elevation of the headwaters of the Arkansas River, making groundwater flow from. the flooded workings to the Arkansas River unlikely. The Division will require some additional elevation information along these lines, specifically, what ie the ~6 shaft collar elevation compared to the elevation where the Arkansas River crosses the Mosquito Fault? A geologic map showing the Mosquito Fault trace and topography would be helpful in this regard. The Division concurs with Climax's assessment that the Mosquito Fault forms a physical barrier to groundwater flow to the west, and if the new pump station elevation is lower than the elevation where the Arkansas River crosses the fault trace, the Divsion can accept the assessment that impacts to the Arkansas from Level flooding are unlikely. The operator has proposed that "the surface will be monitored for seeps as the target shaft water level is approached". Also, at the time of this inspection a bedrock monitoring well had been installed between $6 Shaft and the Mosquito Fault "in order to observe the groundwater level as water rises in the shaft". The Division concurs that these are prudent steps to verify geohydrologic assumptions and assure that impacts to surface water do not occur when the 600 level is flooded. The Division will require that the surface seep monitoring program and water table elevation well monitoring program be incorporated into the Reclamation Permit in the following manner: The operator should propose a subject area of the surface which will be the area scrutinized for seep development. This subject should include, at a minimum, any surface that is topographically lower than the target water level in #5 shaft, for which there is no obvious groundwater flow barrier intervening between the topographically low area and the underground workings. All subject areas selected should be surveyed for pre-existing seeps, springs, bogs, and other wet areas. Without this background information, the proposed seep monitoring "as the target shaft water level is approached" would be of limited value. The operator's proposal fOr seep monitoring subject areas, as well as the results of a background seep survey, and a proposal for timing and frequency of future seep monitoring, should be submitted to the Divsion for review and acceptance. Seep survey results can moat conveniently be included in the Annual Reclamation Report. The water table monitoring well location and completion information should be submitted for inclusion into the Reclamation Permit file. The well and #6 shaft should be monitored monthly for correlatable water level information once the pump station is relocated. if the initial data indicate a need to either increase or decrease this monitoring frequency, the operator should contact the Division. This information can be included in the Annual Reclamation report. One of the chief considerations when underground workings are to be flooded, is an assurance that any PCP transformers and ballasts have been removed. Climax undertook a PCB elimination program during the 1980'x. The Division must be provided with the pertinent documentation demonstrating that PCB's were eliminated from the underground workings prior to relocation of the pump station. In order to inspect the underground workings, we accessed the 600 level via the A`6 Shaft, and proceeded to No. 3 Loci shop. A tremendous amount of equipment will be abandoned on the 600 level when it is flooded, including an overhead crane in this Loci shop. The critical consideration from a groundwater impact standpoint is that alI solvent a, paints, fuels, lubricants or other soluble or miscible potential groundwater contaminants are removed. This task, for the most part, has been completed at No. 3 Loci shop, but a final pass to remove a few spray cans, etc. must be completed.