Laserfiche WebLink
r► <br />Lo- <br />RECEIVED <br />� GEI <br />November 3, 2014 kfnV 2 5 2014 <br />GEI Project Number 140521 -0 DIVISION OF RECLAMATION <br />MINING AND SAFETY <br />Eric Scott <br />-VColorado Division of Mining, Reclamation, and Safety <br />V 1313 Sherman St., Room 215 <br />Denver, CO 80203 <br />Re: -Geotechnical Stability Analysis for Martin Marietta Materials Three Bells Mine, M <br />1979 -191, Larimer County, Colorado <br />Dear Mr. Scott, <br />This letter addresses the Geotechnical Stability Exhibit for the Martin Marietta Materials, <br />Inc. (MMM) Three Bells Mine (M- 1979 -191) Reclamation Permit amendment, per Rule 6.5. <br />The geotechnical stability exhibit is required in the event of unretumed Structure Agreement <br />letters from owners of permanent structures within 200 feet of the mine boundary. <br />The Three Bells Mine is located in southeast quarter of Section 11, the southwest quarter of <br />the southwest quarter of Section 12, the east half of the northwest quarter of Section 13, and <br />the west half of the northeast quarter of Section 13 of Township 6 North, Range 68 West of <br />the 6th Principle Meridian. <br />Permanent man-made structures within 200 feet of the proposed excavation limits include: <br />East Larimer County Road 32E, parking lot, concrete path, various residential buildings, <br />various agricultural buildings, an oil well and pipeline, utility power lines, sewer lines, <br />municipal water station, weirs on the Cache la Poudre River, and bridges over the Cache la <br />Poudre River (see full list on page 2). <br />Geologic Strata and Mining Conditions <br />The Three Bells Mine is located adjacent to the Cache la Poudre River in Windsor, <br />Colorado. Mining will take place in the Three Bells Ditullio property in five phases. Phases <br />1, 3, and 4 will be lined with a compacted clay liner (CCL). Phase 2 will become an unlined <br />pond. Phase 4 will be partially backfilled and Phase 5 will be completely backfilled. <br />Veldman is currently undergoing reclamation with an approximate completion November <br />2014. <br />Boring data gathered from boreholes advanced by others in 2013, in addition to observations <br />made within the mined pits, indicates that overburden is located at the surface of the mine, <br />below which is a layer of pit run (sand and gravel), overlaying bedrock. Overburden and pit <br />run have variable depths, depending on locations in the mine and the mining phase. The <br />www.geiconsultants.com GEI Consultants, Inc. <br />2625 Redwing Rd. Suite 370, Fort Collins, CO 80526 <br />970.224.7343 fax: 303.662.8757 <br />