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Response to Division of Minerals and Geology Second Adequacy Review, Technical <br />Revision No. 6, Portland Limestone Quarry, Permit No. M-1977-344 <br />Holcim (US) Inc. <br />December 13, 2002 <br />The following numbered paragraphs correspond to [he numbering system in the second adequacy <br />review by DMG to Holcim, dated October 22, 2002. <br />Item No. 3 <br />DMG: How will Holcim prevent wind dispersal of CKD after it is placed at an approved <br />disposal site and before it is covered by bac~ll material? <br />Response.• As discussed in Item No. 13 of Holcim's May 2001 response to DMG's fast TR-6 <br />Adequacy Review, CKD generated at the plant is blended with water in a pug mill adjacent to the <br />kiln. The conditioned material is then loaded onto trucks for transport to the quarry. The <br />addition of water improves the material handling characteristics of the CKD, and also serves to <br />control dusting at the point of disposal in the quarry. The CDK is placed down-slope from the <br />end-dump trucks, and then covered by mine spoil within 24 hours. The process is analogous to <br />the operation a solid waste landfill, where a cover is placed upon the advancing face of the waste <br />disposal area. <br />DMG.• In a ground water monitoring plan, please conmrit to a monitoring well down gradient of <br />the CKD disposal area in cut 12. <br />Response: As discussed with DMG at the September 13, 2002 meeting, during subsequent site <br />inspections, and in follow up phone conversations, Holcim commits to a monitoring well down <br />gradient of the CKD disposed of in this area. This is reflected in the Groundwater Monitoring <br />Plan submitted with this response. The Holcim Groundwater Monitoring Plan summarizes data <br />from past monitoring efforts to date, proposes additional monitoring of existing wells, and <br />proposes a new down gradient monitoring well located near the quarry office and a new up <br />gradient well located neaz existing monitoring well MW-6. <br />Item No. 4 <br />DMG: Please provide a ground water monitoring plan that includes monitoring of all ground <br />water wish potential to be impacted by CiYD disposed, or is planned to be disposed of, within the <br />permit boundary. Your response to this item can be included in your response to New Item No. <br />26. <br />Response: Holcim has provided its Groundwater Monitoring Plan with this submittal. The <br />current plan addresses the monitoring of existing and future CKD disposal areas located west of <br />the Bear Creek watershed, and west of the northwest-trending fault zone that roughly divides the <br />permit area in two. As discussed with the DMG in a November 4, 2002 conference call, if the <br />need arises, Holcim commits to apply for a future technical revision to address remaining <br />groundwater issues related to any required future disposal of CKD in areas yet to be mined in the <br />Bear Creek watershed. The available CKD disposal capacity in the current mining area is <br />approximately 12 years. DMG concurred with the Holcim proposal to defer chazacterization and <br />