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WMU FU-06 November 2006 Forward Landfill Project No.021605.07 Upon completion of excavation of the sump, porous suction cup lysimeters were placed in the subgrade beneath the sump. Vector's CQA Monitor observed that the Contractor tested the lysimeters to ensure their functionality prior to covering them with subsequent materials. 4.2 Subgrade Fill Subgrade fill is defined as the material placed on the 5:1 north slope overlying the former Austin Road Landfill. Subgrade fill material was placed in maximum 8-inch loose lifts and compacted with a CAT 815 sheepsfoot compactor. Moisture was added in place with a water truck and mixed into the soil with a road grader. After the fill material was compacted, field density tests were conducted with a nuclear density gauge to ensure 90% relative compaction and moisture content within ±4% of optimum moisture content (ASTM D 1557). Test and sample locations for the foundation layer soils are included in Appendix C. Vector's CQA Monitor obtained samples of the material for CQA testing ecto Q p Q g to ensure the material met the project specifications. Approximately 35,000 cy of subgrade fill was placed. The CQA monitoring of the subgrade fill placement included the following: Atterberg Limits and Grain Size Analysis of Subgrade Fill Soils: The CQA testing for the subgrade fill consisted of performing testing for Atterberg limit (ASTM D- 4318) and sieve analysis (ASTM D-422) at a frequency of one per 5,000 cubic yards (cy). Seven (7) sieve analyses and Atterberg limit tests were performed. A summary of the test results is included in Table 3. Detailed results of the subgrade fill material testing are included in Appendix C. Modified Proctor (ASTM D-1557): Vector's CQA Monitor performed seven (7) moisture-density relationships (ASTM D-1557), which corresponds to a frequency of Vector Engineering, Inc. • 143E Spring Hill Drive•Grass Valley, CA 95945-(530)272-2448 -11-