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WMU D-99 Construction September 1999 <br /> Forward Landfill Job No.986011.02 <br /> The temporary leachate collection sump for WMU D-99 was excavated into the <br /> subgrade 4-feet deep with a 6-foot wide bottom and sides sloping at 3:1. The sump <br /> was lined with GCL (instead of clay), geomembrane and covered with geotextile. An <br /> additional piece of geotextile was placed on the bottom of the sump as a cushion layer. <br /> An eleven-foot high, 60-inch diameter HDPE tank was placed on the floor of the sump <br /> above the geotextile. The LCRS pipe located in the trench was connected to the tank. <br /> Coarse gravel was placed in the sump and encapsulated with geotextile. Vector's <br /> CQA monitor observed all aspects of the sump construction to assure that no damage <br /> occurred to the underlying geosynthetics. <br /> 4,5 Operations Layer Protective Soil <br /> Vector's CQA Monitor observed the placement of the operational layer(on the <br /> floor of WMU D-99)which was placed over the 8-oz filter geotextile layer. The <br /> protective soil operations layer was placed to a minimum thickness of 12 inches. The <br /> material was placed in one lift. Vector's Monitor was present during the placement of <br /> the material on top of the geotextile and did not observe any damage to the <br /> geosynthetics. The Contractor also placed operations layer material over the Eastern <br /> Ash Pit cap and 10 feet up the slopes on the east end of WMU D-99. <br /> The cement-filled tires to be utilized for liner ballast on the Class II Leachate <br /> Impoundment were modified by placing a layer of soil materials over the floor. This <br /> design modification was approved by the design engineer (CH2M HILL). This approval <br /> letter is presented in Appendix N. The soil material was placed to a minimum thickness <br /> of 14 inches. The material was placed in one lift. Vector's Monitor was present during <br /> the placement of the material on top of the primary geomembrane and did not observe <br /> any damage to the geosynthetics. <br /> Vector Engineering, Inc. - 12438 Loma Rica Dr., #C - Grass Valley, CA- (530)272-2448 <br /> -10- <br /> r <br />