Laserfiche WebLink
Page 2 of 3 <br />that concrete lining be used <br />NECC: Attached are amended pages 2.05 -54 and 55. Page 2.05 -54 explains that any water <br />bearing zone(s) in the shaft will be ring grouted from the surface. There should be no concerns <br />with using a shotcrete lining since water inflows will be sealed off by grouting. <br />DRMS: It is the Division's understanding from a meeting held between representatives of New <br />Elk Coal Company and the Division on April 17, 2012, that the proposed airshaft is to be <br />completely lined with concrete. Please send the necessary amended pages having the proposed <br />airshaft completely lined with concrete. <br />NECC: Concrete lining is not necessary to achieve long term control of water inflows. The <br />attached letter report explains how the shaft will be constructed to cut off any groundwater <br />inflows. Page 2.05 -54 was amended to reference Exhibit 44, Bates Shaft Construction <br />Clarification. <br />DRMS: The Division recognizes that a combination of grouting and shotcrete lining, as <br />outlined in the August 7, 2012 letter from Agapito Associates, Inc. (AAI), is an effective <br />technique, in principle, to seal water bearing zones. In order to approve the proposed plan the <br />Division requires that relevant pages of the permit be amended in order to commit NECC to a <br />detailed plan. <br />In addition to the information already contained in previous correspondence, these amendments <br />should include detailed descriptions of <br />a. The grouting technique and specifications of the type of grout to be used, with <br />particular reference to how they are designed to address groundwater flow through both <br />primary and secondary porosity in water bearing zones (i.e. groundwater flowing <br />through pores between grains of the bedrock, and groundwater flowing through <br />fractures and voids in the bedrock); <br />b. How NECC will comply with Rule 4.07, Sealing of Drilled Holes and Underground <br />Openings for the Bates Shaft project. Specifically, Rule 4.07.3(2) requires that holes <br />completed in aquifers be sealed using cement or other suitable sealant by placing the <br />sealant in the hole, from the bottom to within 10 feet of the surface. Holes which <br />penetrate multiple aquifers or bedrock aquifers not exhibiting artesian flow at the <br />surface may be sealed using a solid cement plug or other suitable media approved by <br />the Division extending 20 feet above and below the water bearing zone. <br />5. Item is resolved. <br />6. Item is resolved. <br />7. Item is resolved. <br />8. Item is resolved. <br />9. Item is resolved. <br />10. Item is resolved. <br />11. Item is resolved. <br />