2012-09-06_REVISION - M2008070 (18)

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Western Gravel E &P Waste Disposal Facility October 2011 CQA/QCP Page 3 of 19 analyses. One hydraulic conductivity tests will be conducted on the gravels as they are placed. Table 3 shows the required laboratory tests and testing frequencies for the gravels prior to and during construction. Care shall be taken not to damage the liner materials and HDPE leachate collection pipe during the placement of the gravels. The CQA Engineer shall observe the placement of the gravels. There is no numerical compaction specification for the gravels being placed as part of the leachate collection system; however, placement and light compaction shall be conducted to the satisfaction of the CQA Engineer. Protective Soil Cover /Operations Laver The protective soil cover materials /operations layer to be placed under the leachate collection gravels, over the one -sided geonet placed along the side slopes and over the geotextile fabric placed over the leachate collection gravels shall be relatively permeable material consisting of sandy or gravelly soil. There are no specific gradation specifications for these materials other than the maximum particle size will be 2 inches for the operations layer and a maximum particle size of 3/8 inch for the protective soils placed directly over the liner materials and under the leachate gravels. The CQA Engineer shall approve the materials being used and observe the placement of these materials. There is no numerical compaction specification for these materials; however, placement and light compaction shall be conducted to the satisfaction of the CQA Engineer. Anchor Trench Backfill The soils used as anchor trench backfill shall consist of the on -site soils removed from the anchor trench excavation. The anchor trench backfill materials will be placed in loose 12 to 18 inch maximum lifts and wheel - rolled or compacted with a hand operated compactor to the satisfaction of the CQA Engineer. Care shall be taken not to damage the liner materials during compacti on of the anchor trench backfill materials. The CQQ Engineer shall observe the compaction operations as the anchor trenches are backfilled. There are no prescribed quantitative tests for these backfill materials; however, at the discretion of the CQA Engineer, laboratory and field compaction testing may be requested. Riprap Riprap used in the drainage channels shall consist of hard, dense, durable stone resistant to weathering. The riprap shall have a specific gravity of at least 2.5. Material used fo r riprap must be approved by CQA Engineer prior to placement. No specific testing of this material is required. However, the CQA Engineer may require the contractor to furnish laboratory abrasion resistance testing if in the CQA Engineer's opinion the stone is marginal or unacceptable. Nominal stone size and total thickness of riprap shall be as shown on the Design and Construction Plans. Control of the gradation will be by visual inspection performed by the CQA Engineer. A layer of Mirafi 160N or equivalent geotextile fabric shall be placed over the finished subgrade surface prior to placement of the riprap. NWCC INC.