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Hazeltine/Road Runners Rest II/Brinkmann-Woodward Gravel Pits Lining Project -Design Technical Memorandum <br />Denver Water <br />Augus[2003 <br />The claystone is mostly gray to dark gray, with low to medium plastic fines, and is generally <br />massive with no apparent bedding. Fractures are generally tight and clean, and occasionally <br />slickensided. Occasional to frequent lignite inclusions are common. The claystone ranges <br />from very soft to hard and is often brittle and friable. <br />Sandstone and siltstone layers were identified in ] 6 of the borings. The layers range between <br />0.2 and 19 feet thick, but are generally 2 to 10 feet thick. The transition between the <br />claystones, siltstones, and sandstones is mostly gradual, but occasionally is abrupt and well <br />defined. <br />The sandstone was mostly narrowly graded, fine to medium grained sand with 5 to 25 percent <br />non- to medium-plastic fines. Most sandstone was thinly bedded with bedding planes <br />generally horizontal. Occasionally the sandstone is massive with no apparent bedding. <br />Occasional to frequent lignite inclusions are common. Most sandstone was brittle and friable <br />and poorly to moderately cemented. Occasional well-cemented, hard to very hard sandstone <br />layers were identified. <br />siltstones were encountered in the borings less frequently than claystones or sandstones. Most <br />siltstone consisted of non- to low-plastic fines, with about 5 to 30 percent fine grained, <br />narrowly graded sand. Most siltstone was light brown to gay, very thinly bedded to <br />laminated, and moderately soft to hard and well-cemented. Occasionally, the siltstone was <br />massive with no apparent bedding. <br />2.5 Groundwater Conditions <br />The groundwater level was measured in observation wells that were installed as part of the <br />subsurface investigations and also in each open borehole at the completion of drilling. <br />Groundwater levels are recorded on each boring log and in tables presented in the Geotechnical <br />Data TM (GEI, 2000) and the Addendum to Geotechnical Data TM (GEI, 2003). The water <br />level in the pits at the time of drilling was at about El. 5005. <br />Groundwater was encountered at depths ranging from 10 to 30 feet corresponding to elevations <br />of 4,997 feet to 5,023 feet. <br />The groundwater level measurements represent conditions at the times and locations indicated. <br />Significantly different groundwater levels may occur at other times and locations. Also, the <br />groundwater levels measured in the open boreholes may not represent the equilibrated water <br />levels because the groundwater in the borehole may not have stabilized at the completion of <br />drilling. <br />GEI COI1SUltant5, 1nC. 6 o;oso n: -oi.;i u.nydi~~r oz~,~rti <br />