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Mr. Mark Johnson <br /> January 24, 2020 <br /> Page 4 <br /> feet north of the highwall. The stability analysis on this section was run with potential failure circles <br /> initiating at the gravel road and terminating in the area near the base of the mine highwall. <br /> Section E This section is on the northwest side of Cell 2a and considers the case of the tallest <br /> highwall and the closest structure(a fence)on this side of the cell. The stability analysis for this <br /> section assumes the presence of a slurry wall and a mine highwall of 3H:1 V. The fence is located <br /> approximately 47 feet west of the highwall. The stability analysis on this section was run with potential <br /> failure circles initiating at the fence and terminating in the area near the base of the mine highwall. <br /> ► Cell 2b: <br /> Section A This section is on the northeast side of cell 2b and is the tallest highwall in the cell.The <br /> stability analysis for this section assumes a mine highwall sloped at 2 horizontal to 1 vertical(21-1:1 V). <br /> The nearest structure is a fence located approximately 20 feet to the north. The stability analysis on <br /> this section was run with potential failure circles initiating at the fence and terminating in the area near <br /> the base of the mine highwall. <br /> ► Cell 3: <br /> Section C This section is on the northeast side of cell 3 where the tallest highwall is present. The <br /> nearest structure is the Tri-Town Drainge District drain channel located approximately 45 feet to the <br /> east. The stability analysis for this section assumes the presence of a slurry wall and a mine highwall <br /> of 3H:1 V. The stability analysis on this section was run with potential failure circles initiating at the <br /> drainage ditch and terminating in the area near the base of the mine highwall. <br /> ► Pond A: <br /> Section H This section is on the west side of Pond A in an unmined area with a previously <br /> constructed slurry wall. Available borehole data indicates the depth to bedrock and corresponding <br /> highwall height would be approximately 21 or 22 feet. We conservatively modeled this section with a <br /> highwall height of 30 feet. The highwall is 25 feet from the slurry wall and mined at a 3H;1 V slope. <br /> The nearest structure is a gas line located approximately 31 feet from the mine limit. The stability <br /> analysis on this section was run with potential failure circles initiating at the gas line and terminating in <br /> the area near the base of the mine highwall. <br /> Section 1 This section is on the north side of Pond A(Shores Gravel Mine) in an unmined area with a <br /> previously constructed slurry wall. Available borehole data indicates the depth to bedrock and <br /> corresponding highwall height would be approximately 21 or 22 feet. We conservatively modeled this <br /> section with a highwall height of 30 feet. The highwall is 25 feet from the slurry wall and mined at a <br /> 3H;1 V slope. The nearest structure is the Rural Ditch located approximately 74 feet from the mine <br /> limit. The stability analysis on this section was run with potential failure circles initiating at the Rural <br /> Ditch and terminating in the area near the base of the mine highwall. <br /> MATERIAL PROPERTIES <br /> The material index and engineering strengths assumed in this slope stability report are discussed below. <br />