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8 —The type of grout that will be used to plug the holes is typical Portland cement grout. The 1St <br /> method of plugging is to use rubber grout plugs at the collar seated by turning plug in/near the <br /> hole collar. Holes plugged in this manner will be inspected weekly for two weeks. If any leakage <br /> is found, the 2nd method will be used. The 2nd method of plugging is to inject the grout into the <br /> hole using pressure from the collar with Portland type 2 cement (until it stops entering, <br /> meaning that the entire hole will be grouted. The reason for initially using the rubber plugs is <br /> that it may be possible to lease the water later that comes from the new holes. Therefore, after <br /> water tests are evaluated, a decision will be made to obtain a discharge permit. Once this <br /> permit is obtained, the plugs may be removed and the water will need to comply with the <br /> permit. Cement grouting the holes makes the re-opening difficult. If it is decided to not pursue <br /> a discharge permit, cement grouting will be used to permanently plug the entire length of all <br /> holes, if water is emanating from those holes. <br /> 9—There is a length of main tunnel of approximately 500 feet that will require some additional <br /> timbering and foam roof support. Only a portion of the 500 feet length will require the work. The <br /> timbers used will be standard wood timbers and the foam will be used to ensure that the roof is <br /> safe for personnel movement. The foam is a solid that will not affect the ditch water in the mine <br /> in any way. No blasting will be undertaken as part of this NOI. <br /> 10—There will be 5000 to 10,000 feet of coring as part of this NOI project. There will be no new <br /> entry development, no mining of veins and no bulk sampling of any kind. The cores will be <br /> removed and taken off site for geologic evaluation and sampling. The holes are expected to be <br /> 250 to 1500 feet long. The exact number of holes is to be determined as the project progresses. <br /> For example, if the 1St hole extends 1500 feet, and the second hole extends 1200 feet, the <br /> remainder of drilling may only be in 4 holes. If the lengths in the initial holes are less, there <br /> could be more holes. The fixed amount known is the total amount of coring (5000-10,000 ft). It <br /> is also expected that the total number of drill stations will be three. It may happen that more than <br /> one hole will be drilled from one station since one hole may be in a different direction and <br /> different angle than the 1st hole. <br /> 11 —The applicant believes that a discharge permit will not be needed for this NOI due to the <br /> measures outlined to ensure that the existing water is unaffected. The applicant recognizes that <br /> this will be a determination that the CDPHE will make based on the information provided. We <br /> applied for an NOI for identical type work at the Revenue Mine in Ouray County and the <br /> CDPHE ruled that no discharge permit was needed for this exploration. This project is much <br /> smaller in scope than the Revenue Mine. <br /> 12—The applicant does not believe there is a reasonable potential to affect ground water quality. <br /> The water that has exited the mine for over 100 years has encountered the host rock Leadville <br /> Limestone as well as various vein structures that were targets for the mine operation. Water <br /> enters the mine from these vein structures and the quality has proven to be good for many years. <br /> See Appendix B. It is extremely unlikely that the proposed drilling will encounter some new vein <br /> or other contaminated zone that would then exit through a new drill hole. As previously <br /> explained, all drill holes will be plugged if any water is encountered at all. It is also extremely <br />