2009-12-21_REVISION - M1980244 (40)

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October 2004 -11- 043 -2170 1FC Drawing 14, Detail 1 shows a typical Leak Detection Trench Section. Ames excavated the • trenches to minimum 1 -foot by I- foot cross- sectional dimensions, and a minimum one percent grade. Ames placed geosynthetics, 4 -inch diameter perforated corrugated polyethylene (PCPE) pipe, and LDF in the trench. Ames placed approximately 250 cubic yards of LDF, 19,680 square feet of 40 -mil smooth Linear Low Density Polyethylene (LLDPE) geomembrane, and 33,000 square feet of 12 -ounce non -woven geotextile in the LDT. The LDT geosynthetics installation is discussed further in Section 3.2. 2.4 Site Grading .Prior to SF placement, Ames conditioned and compacted the subgrade surface of the fill area. Golder monitored the preparation of the subgrade and verified that it met project specifications. Ames graded existing slopes and placed SF so that final slopes were no steeper than 2.5H:1 V. Prior to fill placement, the in -situ material was scarified to a depth of approximately 6 inches. SF was compacted with a minimum of four passes by a smooth drum vibratory compactor. Ames placed approximately 122,500 cubic yards of SF within the Phase IVc OSA for site grading. 2.5 Subgrade Preparation Prior to SLF placement, Ames moisture conditioned and compacted the entire surface of the Phase We OSA with a smooth drum vibratory compactor. The quality of the surface was then maintained until SLF was placed. 2.6 Soil Liner Fill Based on neat -line survey, Ames placed and compacted approximately 96,450 cubic yards of SLF in the Phase We OSA. Record Drawing No. 3 in Appendix A presents the as -built surface of the SLF. Ames processed bentonite amended SLF for the Phase IVc OSA construction, beginning in March 2004 and finishing in September 2004. Ames worked the borrow material through a custom designed rotary mill and screen to remove oversized material from the SLF and to uniformly condition the 0417 e,.QAftNrI 237UQ&12,M.tE,PWC.d« Golder Associates