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As-Built CQA Report for the Construction of Area 2A at the Foothill Sanitary Landfill San Joaquin County,California 4.0 FOUNDATION LAYER CONSTRUCTION 4.1 FOUNDATION LAYER PREPARATION The foundation layer material in the floor area was specified to have a maximum particle size of % inch and a maximum aggregation (clods) size of 1-inch. Additionally, for the areas to receive geosynthetics,the Specifications required that any rock,aggregation or debris that protrude 1/z-inch or more,be removed from the surface. During excavation, the Contractor selectively stockpiled materials with higher fines content south of the Area 2A floor. No processing of the stockpiled materials was performed. The Contractor overexcavated the floor to a depth of one foot below the finish grade of the foundation layer. The stockpiled foundation layer material was hauled by CAT 627 scrapers to the floor, spread by CAT 14H motorgrader and moisture conditioned using water trucks or CAT 621 water pull. Loose lift thickness was approximately 6 to 8 inches. Material was then compacted using a CAT 825 with a sheepsfoot attachment. Due to the cementation of the native onsite materials, the initially placed foundation layer lifts had excessive clods larger than 1-inch size. The Contractor then reworked each lift using a combination of methods and equipment including a motorgrader, a CAT 825 compactor, and a CAT CS54B vibratory smooth drum roller to break down the clods. Typically the placement would begin during the morning and in the afternoon the lift would be reworked to break down clods. The Contractor also routed the scraper traffic to wheel roll previous lifts to further aid in the breaking of clods.The resulting reworked material had only minimal of clods, typically between 3 to 5 percent, and less than 2 inch in maximum size. The material was moisture conditioned to 0 to 4 percent above optimum and compacted with the CAT 825 steel wheel compactor. 4.2 CQA OBSERVATIONS AND TESTING OF FOUNDATION LAYER MATERIAL The CQA observations and testing for the foundation layer soil included testing material quality at the specified frequency. Following placement,clod size reduction was monitored by taking samples and performing field sieve analyses per ASTM D422. Following acceptance of each lift for clod size (no greater than 5percent), the compaction of each lift was monitored by AES CQA Monitors. The CQA Monitors performed field density tests using the nuclear gauge method (ASTM D6938) and the sand cone method (ASTM D1556) at the frequency listed in the following table.The number of tests actually performed and the required minimum number per the specified frequency are listed below: • P:114 Projects114-101(SJCDPW North County and Foothillff oothill CQAIReportlFinal ReportToothill CQA Rport-Final.docx 14