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NORWEST Suite 1830, 1066 W. Hastings Street <br /> Vancouver, <br /> ver, BC VISE 3X2 <br /> Tel:(604)602-8992 <br /> C 0 R P 0 R A T 1 0 N www.norwestcorp.com <br /> ® IOQM <br /> CERTIFIED <br /> Memorandum <br /> To Transit Mix Concrete Company Project# 591-6 <br /> CC Paul Kos, Norwest—Denver Office Date March 26, 2018 <br /> From Sean Ennis <br /> Subject Hitch Rack Ranch Pit Wall Geotechnical Assessment—Supplemental CDRMS Response <br /> 1. INTRODUCTION <br /> Norwest Corporation (Norwest) was retained by Transit Mix Concrete Co. (Transit Mix) to provide design <br /> and engineering support for the proposed Hitch Rack Ranch (HRR) granite quarry in Colorado, USA. The <br /> proposed quarry is located approximately 15 miles south of Colorado Springs, CO, in El Paso County.The <br /> site is currently unimproved with relatively steep hills rising to the north and south. The proposed quarry <br /> development lies south of Little Turkey Creek(see Figure 1). <br /> Norwest's current work scope includes support for Transit Mix's regulatory submission for the quarry.This <br /> memorandum is intended to provide supplemental information related to the pit wall stability analyses <br /> completed for the proposed quarry. A more detailed memorandum summarizing Norwest's site <br /> characterization and pit wall design was submitted in 2017 (Hitch Rack Ranch Pit Wall Geotechnical <br /> Assessment,Sept. 11, 2017) and this memorandum uses information from that document. <br /> 2. Site Conditions <br /> Norwest carried out a site investigation on the Hitch Rack Ranch property between August 2 and <br /> October 4, 2015.A total of seven (7) boreholes were advanced to depths between 200ft and 800ft below <br /> existing grades. Drilling was completed by Major Drilling Inc. of Salt Lake City, Utah. Six (6) of these <br /> boreholes were advanced in the area north of Little Turkey Creek, and one (1) borehole was advanced in <br /> the area south of Little Turkey Creek where the proposed quarry is located. There are six (6) new <br /> monitoring wells and one piezometer installed by Norwest representatives in July 2017. These wells are <br /> primarily intended to provide information on groundwater levels around Little Turkey Creek but they do <br /> provide information on rock types, rock quality,and other geotechnical information in the area. <br /> 2.1. Groundwater Conditions <br /> The groundwater conditions were assumed to be dry for rock mass characterization purposes.This <br /> is common practice as groundwater effects will be added during stability analyses and the <br /> assumption is not meant to imply there is no groundwater within the rock mass. Sensitivity of pit <br />