2008-11-26_PERMIT FILE - M2008080 (10)

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Geotechnical Engineering Report Sand and Gravel Study Terracon Project No. 21085006 Terracon Lithologic logs of each boring were recorded by the geotechnical engineer during the drilling operations. At selected intervals, samples of the subsurface materials were obtained by collecting bulk samples of material through the cutting funnel. Groundwater measurements were made in each boring at the time of site exploration. All borings were filled after drilling operations due to safety considerations for livestock on site. Minor boring settlement should be expected, some maintenance should be anticipated. Laboratory Testing: Samples retrieved during the field exploration were returned to the laboratory for observation by the project geotechnical engineer, and were classified in general accordance with the Unified Soil Classification System described in Appendix C. At that time, an applicable laboratory-testing program was formulated to determine physical properties of the subsurface materials. Following the completion of the laboratory testing, the field descriptions were confirmed or modified as necessary, and Logs of Borings were prepared. These logs are presented in Appendix A. Laboratory test results are presented in Appendix B. Laboratory tests were performed in general accordance with the applicable local or other accepted standards. SITE CONDITIONS The approximately 100-acre site is, currently used primarily for pasture and agricultural purposes. The site was bounded on the north by the Cache La Poudre River, on the east by Weld County Road 51, on the south by Weld County Road 58, and on the west by hilly terrain with sparse residential/agricultural development. The ground surface was generally flat to gently rolling. Vegetation consisted of grasses and native weed growth. Geology: Surficial geologic conditions at the site, as mapped by the U.S. Geological Survey . (USGS) ('Tweeto, 1979), consist of Post Piney Creek Alluvium of Upper Holocene Age. This material generally consists of dark gray humic, sandy to gravelly alluvium. These materials, as mapped in this area, are generally on the order of about 20 feet in thickness. Economic Mineral Potential:. Mapping performed by the USGS (2Schwochow, Shroba, and Wicklein, 1974) indicates that the site lies in an area of flood-plain and valley fill deposits along 'Tweeto, Ogden., 1979, Geologic Map of Colorado, United States Geological Survey, Map 1-855-6. 2Schwochow, S.D., Shroba, R.R., and Wicklein, P.C., 1974, Sand, Gravel, and Quarry Aggregate Resources of the Colorado Front Range Counties, Colorado Geological Survey, Special Publication 5-A, Plate 1. 2