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<br />Procedural Memo - Henderson -2- Februarv 6, 1997 <br />the goal would be to minimize the need for long term pumping and <br />treatment of mine water (elimination of the need to pump and treat <br />water is not currently feasible for the Henderson Mine). CMC has <br />submitted technical revision TR-006 to the Henderson Permit to provide <br />an alternate reclamation plan for the Division to follow in a bond <br />forfeiture situation that would minimize the need for pumping and <br />treating mine water. Under the plan described in TR-006, the Division <br />would have to pump and treat water from the lowest level of the mine <br />for a period of time sufficient to allow for removal of any hazardous <br />or toxic materials that may be present in the underground workings. <br />The mine could then be allowed to flood up to the 8100 level pump <br />station, where pumping could be resumed at a theoretically lower rate. <br />Concurrently, a plug would be designed and installed in the haulage <br />tunnel in order to prevent release of mine water to the Williams Fork <br />in the event that the mine were ever allowed to flood completely. <br />Ideally, Rule 4.2.1(4) require that sufficient bond funds need to be in <br />place to conduct any water management and treatment necessary during <br />the period of time that the Division is installing facilities that <br />would eliminate the need for water treatment. For example, if a mine <br />drainage tunnel were discharging at a relatively low flow, and if the <br />contaminant levels were not excessive, tunnel plugging or some form of <br />passive treatment may be installed that would allow the site to be <br />closed without a need for an active presence to protect water quality. <br />In a case such as this, a bond amount would have to be in place that <br />would fund water treatment during the period of time it would take to <br />install a plug or construct passive treatment facilities. <br />Determination of the appropriate period of time would be relatively <br />straight forward. In the case of the Henderson Mine, the determination <br />of the period of time over which the Division would have to pump and <br />treat water is not so clearly defined. The Division would pump and <br />treat water from the lowest level of the mine for a period of time <br />necessary to mobilize to the site, to inspect the underground workings, <br />and to remove any hazardous or toxic materials from the mine, taking <br />perhaps 1.5 years. In the interim, the haulage tunnel would be <br />ventilated from the west portal, and a plug for the haulage tunnel <br />would be designed. While traditional surface reclamation proceeds and <br />the haulage tunnel plug is installed, the mine would be allowed to <br />flood to the 8100 level. The period of time needed for this partial <br />flooding to occur needs to be carefully estimated. The Division would <br />resume pumping and treating the mine water once flooding reaches the <br />8100 level, and would continue pumping and treating from the 8100 level <br />until one of the following situations occurs: <br />1. Installation of the haulage tunnel plug is completed. <br />2. A smooth transition of water treatment responsibilities is <br />completed with whatever entity is going to continue on-going <br />treatment. <br />