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A field permeability test (sealed double ring infiltrometer [SDRI]) was conducted on onsite soils in 2001 to assess their suitability as clay liner material. The field permeability test indicated that the • onsite soils could achieve a field hydraulic conductivity of 1 x 10"' cm/sec. The clay liner will be constructed using techniques and materials similar to those used in constructing the test pad for the field permeability test. Laboratory hydraulic conductivity, particle size analyses, compaction, Atterberg limits, and field density and water content testing will be performed on the clay liner during construction as part of the construction quality assurance(CQA)program. The CQA Manual is included in Appendix D. After constructing the clay liner, the surface of the clay will be protected from desiccation cracks by keeping the surface moist. Immediately prior to geomembrane deployment, the surface of the clay will be prepared by rolling with a smooth drum roller. The entire base of WMU FU-14 will be covered by a 60-mil, double-sided, textured HDPE geomembrane liner. Terminations and future connection edges of the geomembrane will be placed under temporary berms to hold the liner secure during construction and filling. Along future connection edges, the geomembrane edges will be protected by geotextile,plywood sheets, and buried under earth berms. 5.1.2 HDPE Geomembrane The 60-mil HDPE geomembrane will be installed in accordance with the Specifications (Appendix Q. Extensive CQA will be performed on the geomembrane to identify and repair defects. Tests will be performed on both the geomembrane and on the field-constructed seams. A leak location test will be performed on the geomembrane following installation of the geomembrane itself and following placement of the protective operations layer. CQA inspection and testing procedures are defined in the Specifications(Appendix C)and in the CQA Manual(Appendix D). 5.2 Leachate Collection n Removal System (LCRS) Design calculations were performed to establish that the WMU FU-14 LCRS would meet the Title 27 requirements that the LCRS be designed, constructed,maintained, and operated to collect and remove twice the maximum anticipated daily volume of leachate from the disposal unit. To comply with site WDRs and Title 27 requirements, the 1,000-year, 24-hour storm was used in estimating leachate volumes. Calculations were based on a granular drainage layer hydraulic conductivity of 0.1 cm/sec. The leachate generation analysis was performed using the Hydrologic Evaluation of Landfill Performance(HELP)computer model(Schroeder et al, 1988)(see Design Calculations,Appendix B). The cross section analyzed by the HELP model corresponds to a condition of maximum anticipated leachate generation. The maximum leachate generation condition was assumed to occur during placement of the first 10-foot thick lift of refuse in WMU FU-14. The rainfall rate for the 1,000-year, 24-hour storm is 4.79 inches/day. The maximum leachate impingement rate estimated by the HELP model for a maximum drainage length of 150-ft and a LCRS gravel permeability of 0.1 cm/sec is 0.32 inches per day. The HELP analysis shows that the designed LCRS will maintain less than one foot of head over the liner. The base LCRS will be constructed of a 12-inch-thick layer of clean granular material with a minimum hydraulic conductivity of 0.1 cm/sec draining towards leachate collection pipe trenches. The particle size of the granular drainage material has been limited to a maximum of 3/8-inch to protect against puncture of the underlying geomembrane and the overlying geotextile filter fabric,and to a maximum of 3 percent of particles finer than the No. 200 sieve to maintain its permeable nature. The granular drainage material is also specified to consist of well-rounded gravel (i.e., no crushed 0 WMU FU-14 REPORT.DOC 5-2