2021-06-17_PERMIT FILE - M2001046 ‎(4)‎

• Permit No: M2001046
• IBM Index Class Name: PERMIT FILE
• Doc Date: 6/17/2021
• Doc Name: Adequacy Review Response
• From: Ready Mixed Concrete Company, LLC
• To: DRMS
• Type & Sequence: AM1
• Email Name: ECS
• Media Type: D
• Archive: No

Mr. Joe Lamanna
June 9, 2021
Page 3
STRUCTURES WITHIN 200 FEET OF DISTURBED AREAS
The known, permanent, man-made structures within 200 feet of the proposed mine areas that are not owned by Ready
Mixed Concrete Company are listed below:
• KERR MCGEE/ANADARKO GAS LINE SOUTH OF CELL 2—58.9'
• KERR MCGEE/ANADARKO GAS LINE SOUTH OF CELL 2—64.46'
• CENTRAL WELD COUNTY WATER DISTRICT WATER LINE SOUTH OF CELL 3— 72.39'
• KERR MCGEE/ANADARKO GAS LINE SOUTH OF CELL 2—77.91'
• KERR MCGEE/ANADARKO GAS LINE SOUTH OF CELL 2— 152.30'
• COUNTY ROAD 28— 150.88'
• KERR MCGEE/ANADARKO GAS LINE WEST OF FRESH WATER POND—30'
• VARRA CONVEYOR WEST OF FRESH WATER POND—37.44'
• CENTRAL WELD COUNTY WATER DISTRICT WATER LINE WEST OF FRESH WATER POND—47.8
• COUNTY ROAD 17— 71.8'
• COLLINS CONSTRUCTION, 13187 CORD 17— 151.66'
• KERR-MCGEEIANADARKO 0&G SEPARATOR— 71.83'
• KERR-MCGEE TANKS— 112.58'
• VARRA FENCE NORTH OF FRESH WATER POND—84.39'
• COUNTY ROAD 19— 106'
• MILLER FARM BUILDING 191'
• BARN— 188'
• RESIDENTIAL PROPERTY 183'
• HOUSE AT 8567 CO RD 30— 167'
• HOUSE AT 8680 COLORADO 66— 178'
• XCEL OVERHEAD ELECTRIC NORTH OF COLORADO 66— 154'
• COLORADO 66- 101'
• KERR-MCGEE WELL SOUTH EAST CELL 3—30'
• KERR-MCGEE GAS LINE SOUTH EAST CELL 3—30'
• XCEL OVERHEAD ELECTRIC EAST OF CELL 3— 75'
• XCEL OVERHEAD ELECTRIC EAST OF CELL 3— 137'
• XCEL OVERHEAD ELECTRIC WEST OF CELL 3 -67'
'Oil and gas structures planned for removal have not been included in this list.
STABILITY ANALYSES
Recently, Division of Reclamation and Mining Safety(DRMS)staff drafted a policy regarding stability analyses of
neighboring structures. The draft summarizes adequate factors of safety(FOS)for non-critical and critical structures.
The structures around the Nix mine are,for the most part, considered critical structures. Discussions with the author of
the memo, Mr.Tim Cazier, indicate the FOS will be adopted by the MLRB. The FOS are for both static and seismic
(from an earthquake)stability analyses. For generalized strength assumptions and critical structures,a FOS of 1.5 is
considered sufficient for static conditions and a FOS of 1.3 is considered suitable for seismic conditions.
The stability of structures within 200 feet of the proposed mining limits was evaluated at three sections. The sections
evaluated were at the tallest high wall in each mine cell under anticipated loading conditions around the perimeter of the
site as discussed below. The computer program XSTABL was used for the analysis. The method for selecting the
critical failure surface for each analyzed loading condition is the following. The Modified Bishop's Method of Analysis is
used to find the critical failure surface by randomly searching with 20 termination points and 20 initiation points(400
failure circles)with 7 foot line segments over the slope surface and at the structure in question to determine the lowest