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CIVIL RES~URCES,LLC <br />ENGINEERS ~ PLANNERS <br />September 27, 2004 <br />Mr. Mark Campbell <br />SW TKO Joint Venture, LLC <br />333 West Hampden Ave., Suite 810 <br />Englewood, CO 80110 <br />Re: SW-TKO Joint Venture, LLC Mine, Proposed Gravel Mine Slope Stability Analysis; DMG #M2003.012 <br />Dear Mr. Campbell: <br />This letter has been prepared to address the Mine Land Reclamation Board (MLRB) Construction Materials Rule 6, <br />Section 4, Subsection 19, Exhibit S -Permanent Man-Made Structures {6.4.19, Exhibit S) for the proposed SW-TKO <br />aggregate mine. This letter describes the project and slope stability calculations carried out to evaluate the minimum <br />distance between the edge of mining and adjacent structures to avoid damage to the structure. <br />The site is located approximately one-eighth mile east of the South Platte River (composed of the Villano, Sasaki, <br />Adams, Watada, Yokooji; and Wiant properties). The site is within parts of Sections i8 and f 9 of Township 1 North, <br />Range 66 West of the 6th Principal Meridian. The site is generally bounded on the west by U.S. Highway 85, WCR 6 on <br />the south, and the Fulton Ditch lateral acid WCR 27 to the east.. T.he project is located in Weld County, Colorado, as <br />shown on Figure L <br />Approximately three feet of overburden is undedain by a relatively deep alluvial aggregate deposit, probably to be mined <br />by LaFarge, Inc. The aggregate will likely be transported via conveyor to a processing plant locatetl west of Highway 85 <br />on the existing Lafarge property. <br />This report lists minimum safe setbacks for mining from structures within 200 feet of the permitted boundary based on <br />stability calculations. Actual setbacks may be greater due to permit limitations, zoning requirements, construction issues, <br />agreements with owners, extent of economically mineable aggregate, or other issues. <br />GEOLOGY <br />The site is located approximately 30 miles east of the foothills of the Colorado Front Range on the western flank of the <br />Denver Structural Basin. The basin is a downwarp of sedimentary strata that Vends north-northwest, parallel to the <br />mountain front. In the project area, the sedimentary beds dip gently eastward toward the axis of the basin east of the <br />site. Based on regional geologic mapping (Colton, 1978}, the near surface bedrock in the project area is the Paleocene <br />and Upper Cretaceous Denver and Arapahoe Formations. The bedrock is overlain by upper Pleistocene and Holocene <br />(Quaternary age) gravel deposits and eolian (wind blown) overburden soils. The gravel deposits exist primarily within the <br />Broadway Alluvium deposit. The bedrock unit consists mainly of claystone and may contain lenses of siftstone and <br />sandstone. <br />Subsurface data from earlier aggregate investigations and Civil Resource's geotechnical investigation have been <br />compiled, reviewed, and analyzed. Investigations were completed at the site by the following consultants: <br />4S1 DAK STREET, 6UITE 2D9 ~ P. D. BOX 684 ~ FREDERICK, CO 60534 ~ (3031 833-7 416 ~ (343I 633-2854 - Fnx <br />