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DEERE & AULT <br /> CONSULTANTS,INC. <br /> October 10, 2018 <br /> Mr. Joe Lamanna <br /> Ready Mixed Concrete Company <br /> 11778 Highway 52 <br /> Fort Lupton, Colorado 80621 <br /> Re: Stage 6 Berm; D&A Job No. CG-0473.006.00 <br /> Dear Mr. Lamanna: <br /> This letter presents the Stage 6 berm construction quality control testing results and as- <br /> constructed drawings. <br /> OVERVIEW <br /> Earthen fill was placed along the south side of the Stage 6 berm. The fill work was conducted to <br /> flatten the downstream slope and increase the factor of safety for slope stability to a value of 1.5 <br /> or greater. Construction to place the compacted fill was conducted by Claystone Construction. <br /> A pre-construction meeting was held on August 14, 2018. Construction of the berm fill was <br /> largely completed by August 28, 2018. Geotechnical testing and construction observation was <br /> provided by J. R. Valentine, Inc. <br /> CONSTRUCTION DISCUSSION <br /> 1. Foundation <br /> The construction plan included excavation downstream of the existing embankment to a layer of <br /> unmined sand and gravel. This 2-foot(f) thick layer or sand and gravel was observed in <br /> exploratory borings through the embankment drilled during the design investigation. Test pits <br /> excavated at the start of construction did not encounter the sand and gravel in sufficient thickness <br /> to provide an adequate drainage layer. Nearby pit run material was sourced for borrow and <br /> placed as the bottom 2-foot drainage layer on the claystone bedrock. Clayey embankment fill <br /> was then placed from the drainage layer to the crest of the berm. <br /> 2. Embankment Fill <br /> Clayey embankment fill was excavated from the upper weathered bedrock zone across the <br /> southern two-thirds of the Stage 6 pit. The material was placed in 4-inch to 8-inch thick lifts <br /> across the fill area using scrapers. Once placed, the fill lifts were moisture conditioned and <br /> blended using a water truck and disc. The fill was compacted by an 815 sheepsfoot compactor <br /> along with wheel loads from scraper traffic. Photographs of the finished fill slope are attached. <br /> 600 S.Airport Road,Building A,Suite 205 <br /> Longmont,CO 80503 <br /> Phone 303-651-1468•Fax 303-651-1469 <br />