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As-Built CQA Report for the Construction of Area 2A at the Foothill Sanitary Landfill San Joaquin County,California • h. Gradation and Roundness of LCRS Granular Drainage Material (GDM): The Specifications called for GDM particles to be rounded to subrounded. During the review of Contractor submittals and examination of the gravel samples from local sources, it was concluded that no local product with 100% rounded and subrounded particles was available. The GDM proposed by the Contractor (Cemex 5/16"x 1/8" pea gravel) contained some angular to subangular particles. The Contractor performed a test pad to evaluate and demonstrate that the proposed materials and construction methods to be used during GDM placement will not result in damage to HDPE geomembrane. A 50 ft x 20 ft test pad was constructed on top of composite liner consisting of (from bottom to top) 12-inch thick prepared foundation layer, GCL and HDPE geomembrane. A 9-inch thick layer of GDM was placed on geomembrane using a low ground pressure (LGP) dozer and geomembrane was exposed after careful removal of GDM. The test pad construction was observed by Geosyntec's Project Manager Krzysztof Jesionek. Based on the observations during test pad construction and inspection of the geomembrane following removal of GDM, Geosyntec approved the use of the proposed GDM and the equipment and method for construction of the LCRS layer. The test pad construction and Geosyntec's evaluation are documented in their Construction Memorandum #2 included in Appendix C.1. c. Interface Shear Strength: Prior to approval of geosynthetic materials for deployment, the interface shear strength tests were performed on the base and side slope liner components. • The Specifications called for four single interface strength test series,as follows: A- HDPE geomembrane vs. GCL (for both base and side slope liner) B-GCL vs.prepared foundation layer(base liner) C -GCL vs.side slope subgrade soil (side slope liner) D-HDPE geomembrane vs.geocomposite (side slope liner) The on-site soils for the foundation layer (base liner) and side slope subgrade were the same materials with no significant variation in material type and compaction standards. Therefore, only Test Series B was actually performed and the test results would be considered to be the same for Test Series C. The actual numbering of the test series for the test program was as follows: Test Series 1 -Foundation layer soil vs GCL Test Series 2 -GCL vs. HDPE geomembrane Test Series 3 -HDPE geomembrane vs.geocomposite The highlights/key observations of the test results are summarized below: • PA14 Projects114-101(SJCDPW North County and Foothillffoothill CQA1Report\Final ReportToothill CQA Rport-Final.docx 5