Laserfiche WebLink
l~ <br />LAFARGE ,/ <br />NORTH AMERICA <br />Construction Materials <br />February 25, 2004 <br />Ms. Erica Crosby <br />Environmental Protection Specialist <br />Colorado Division of Minerals & Geology <br />1313 Sherman Street, Room 215 <br />Denver, Colorado 80203 <br /> <br />TR-3 / <br />RECEI®/ED <br />FEB 2 5 2004 '~ <br />Division of Minerals end Geology <br />~ 047 ~ ~ <br />RE: East Rigden Pit, MLRB Permit No. M-1979JYM 2003 Technical Revision <br />Lafarge Reference No. 701-430 <br />Ms. Crosby: <br />In response to your Inspection Report dated March 13, 2003 and subsequent correspondence on <br />September 19, 2003 with Mary Harnett, Lafarge West, Inc. (Lafarge) has prepared the following <br />Technical Revision for the East Rigden Pit. <br />1) Attached as EXHIBIT A is the US Army Corps of Engineers (USAGE) approval for the <br />installation of a low-water crossing within the Cache la Poudre River For the mining of the <br />extreme eastern portion of the Rigden Pit. The mining of this property is included in the original <br />permit and is permitted, however, the low-water crossing was not detailed in that document. As <br />of this Technical Revision, mining is complete, reclamation is nearing completion, and the low- <br />water crossing will be removed in April 2004. Lafarge requests that the DMG approve the low- <br />water crossing as part of this Technical Revision. <br />2) EXHIBIT B contains a drawing of the planned inlet/outlet conveyance for the lateral berm that <br />separates the East Rigden Pit (Permit No. M-1979-079) and the Port of Entry Pit (Permit No. M- <br />1982-182). Since the East Rigden Pit and Port of Entry Pit share this lateral berm, only the inlet <br />side of [he conveyance is applicable to this Technical Revision. In addition, while not contained <br />within the confines of the Urban Drainage and Flood Control District, Lafarge has designed the <br />inlet/outle[ conveyance to meet the standards of the UD&FCD as detailed in their December 1987 <br />document entitled "Technical Review Guidelines for Gravel Mining Activities Within or Adjacent <br />to 100-year Floodplains". The design has been shown to Mr. Bryan Kohlenberg of UD&FCD for <br />review purposes. In addition, based on discussions with Mr. Carl Mount, recycled clean concrete <br />riprap has been approved as a suitable substitute for natural riprap. <br />Western U.S. Region <br />1400 W. 64th Ave., P.O. BOX 21588, Denver, Colorado 80221-0588 <br />Office: (303) 657-4000 <br />Web: www.lafargenorthamerica.com <br />