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HazeltinelRoad Runners Rest IllBrinkmann-Woodward Gravel Pits Lining Project- Design Technical Memorandum Denver Water August 2003 narrowly to widely graded sands with gravel, and silty sands. The alluvium was mostly fine to coarse grained, sub-angular to sub-rounded sand, with about 5 to 35 percent gavel, and from less than 5 percent to about 10 percent fines. The gravel was predominantly fine-grained, sub- angular to sub-rounded in shape. The Louviers Alluvium was typically loose to very dense, dry to wet, light brown to brown to tan and visually classifies as SW, SW-SM, SP, and SM according to the USCS. The standard penetration N-values ranged from 4 to 109 and average about 35. Layers of lean clays, silts, sandy lean clays, clayey sands and silty clays were encountered within the Louviers Alluvium in about half of the borings. These fine-grained layers ranged in thickness from less than 1 foot to about 14 feet. The thickest layers were identified in the lower part of the alluvium in borings B-109, B-I 10, B-119, and B-407. These fine-grained layers were classified as CL, ML, SC, and SC-SM according to the USCS. The silts were typically medium stiff to stiff, non- to low plastic, with less than 15 percent fine sand. The clays and clayey sands were generally stiff or medium dense, low to medium plastic, and contain less than 15 percent sand and less than 15 percent fine gravel. 2.4 Bedrock Bedrock was encountered at depths of 11.0 to 59.0 feet below the existing ground surface. This corresponds to elevations of 4,963 feet to 5,019 feet, respectively. Bedrock was generally encountered at depths between 25 and 28 feet (El. 4990 to El. 4994) and slopes at about 0.3 percent downward to the northeast except along a trough in the bedrock that trends northeast to southwest below the east part of the site. Bedrock was identified at a depth of 11, 13, and 17 feet (boring B-112, B-102, and B-409, respectively), which is located east of the Road Runners Rest II Pit. Bedrock was encountered at substantially greater depths, between 47.0 and 59.0 feet (El. 4972.5 to EI. 4963) in borings B-103, B-109, B-110, B-111, B-119, and B-402 through B-408. These borings are likely in a bedrock trough that appears to be about 700 to 800 feet wide and is located below the eastem end of the Hazeltine and Road Runner Rest II Pits, and the northern and eastem ends of the Brinkmann-Woodward Pit. Bedrock identified in the borings is predominantly claystones of the Denver Formation with occasional interbedded and interlensed sandstones and siltstones. The upper portion of the bedrock is intensely weathered and intensely fractured. Although this upper zone of intensely weathered and intensely fractured bedrock ranged from 2 to 24 feet, it was generally found to be between 2 and 4 feet thick. Bedrock weathering and fracturing generally decrease with depth. Isolated zones of intensely weathered and intensely fractured bedrock below the upper 10 feet of bedrock were identified in almost half of the borings. These zones vary from less than 1 foot thick to about 12 feet thick. GEI Consultants, 1nC. 5 o:oso o?-or-ii in-uuau~r ocs~~~~ni