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Foothill Sanitary Landfill — Module 1 December 2003 <br />County of San Joaquin Job No. 031602.00.02 <br />4.4 LCRS Drainage Layer and Sump Gravel <br />4.4.1 General <br />The granular drainage layer was placed on the floor of Module as a leachate collection <br />and removal system (0.75 -foot), and the sump gravel fill was placed in the LCRS <br />trenches and in the sumps of Module 1. <br />The drainage layer material and gravel fill was obtained from an off-site source. The <br />drainage gravel was placed by dumping the gravel in a pile and pushing the material <br />outward over the geomembrane with a CAT D5 dozer. Vector's CQA Monitor <br />continuously observed the placement of these materials to ensure no damage occurred <br />to the underlying geosynthetics and that no large wrinkles developed. <br />During placement of the drainage layer material, a rain event occurred causing some <br />fines from the operations layer material to migrate into the granular drainage layer <br />material were geotextile had not yet been placed. Vector's CQA Monitor identified the <br />areas were the granular drainage layer was affected and the Contractor removed the <br />material. This material was stockpiled outside the module and washed by water spray <br />to remove the excess fine materials. After the material had been verified by Vector's <br />CQA Monitor to meet the project specifications, the material was placed on the module <br />floor as part of the drainage layer. <br />4.4.2 CQA Evaluation of Drainage Gravel and Sump Gravel <br />Samples of the drainage gravel and sump gravel were obtained and sieve analyses and <br />hydraulic conductivity tests were conducted. Vector's CQA Monitor performed sieve <br />analysis tests on four (4) evaluation samples and eleven (11) construction samples of <br />the drainage gravel. In addition, Vector's CQA Monitor performed sieve analyses on <br />one (1) evaluation sample and one (1) construction sample of the gravel fill. <br />The sieve analysis results on the drainage gravel indicated that 100% of the material <br />was passing the 3/4 -inch sieve and had a minimum D85 of 0.37 inches. The minimum <br />D85 particle size was modified from the specified particle size of 0.45 inches to 0.37 <br />Vector Engineering, Inc. • 143E Spring Hill Drive • Grass Valley, CA 95945 • (530) 272-2448 <br />18 <br />