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Stage 1A Partial Final Closure February 2006 <br /> Forward Landfill Project No.021605.06 <br /> ® 4.2 Compacted Earthfill <br /> A 3-ft thick compacted earthfill is defined as the material placed on the slopes <br /> overlying the existing interim cover material. The material was transported <br /> from the on-site borrow source located directly north of the Stage lA closure <br /> using CAT 633 scrapers. Compacted earthfill material was placed in maximum <br /> 8-inch loose lifts and compacted with a CAT 815 sheepsfoot compactor. <br /> Moisture was added in place with a water truck and mixed into the soil with a <br /> road grader. As each lift was placed, the CQA Monitor verified that the surface <br /> of the lift was scarified and not smooth to assure that no distinct layers <br /> developed within the clay liner and that the specified lift thickness was achieved. <br /> After the fill material was compacted, field density tests were conducted with a <br /> nuclear density gauge to ensure 90% relative compaction and moisture content <br /> within ±2% of optimum moisture content (ASTM D 1557). Test and sample <br /> locations for the compacted earthfill soils are included in Appendix C. <br /> Vector's CQA Monitor obtained samples of the material for CQA testing to <br /> ensure the material met the project specifications. Approximately 180,000 cy <br /> of compacted earthfill was placed. Vector's CQA Monitor also performed <br /> moisture-density relationship (ASTM D-1557) tests, Atterberg limits (ASTM D- <br /> 4318) and grain size distribution (ASTM D-422) tests, sand cone and moisture <br /> content (ASTM D1556), hydraulic conductivity (ASTM D5084), and BAT <br /> Permeability tests on the compacted earthfill material during placement. <br /> Atterberg Limits and Grain Size Analysis of Compacted Earthfill Soils: The <br /> CQA testing for the earthfill consisted of performing testing for Atterberg limit <br /> (ASTM D-4318) and sieve analysis (ASTM D-422) at a frequency of one per <br /> 5,000 cubic yards (cy). Forty (40) sieve analyses and Atterberg limit tests were <br /> performed. The sieve analysis indicated that 100% of the material passed the <br /> Vector Engineering, Inc. • 143E Spring Hill Drive•Grass Valley,CA 95945•(530)272-2448 <br /> -9- <br />