Laserfiche WebLink
rHarding Lawson Associates <br /> trenching to this edge, the location can be determined and the <br /> vapor laterals manifolded to the VES. A single 2" PVC conduit <br /> should suffice for vapor extraction from the two vapor laterals. <br /> Another two-inch PVC lane will attach to the water lateral for <br /> future extraction with a suction pump. <br /> ' b. Excavation of Va or Conduit Trench to the <br /> Treatment Compound. <br /> ' In order to bring the vapor conduit from the <br /> extraction trench and the conduit from the former tank area, into <br /> the treatment compound, a common trench will be installed across <br /> the cement sidewalk and under the brick wall on the west side of <br /> the convenience store. This trench will contain two one-inch <br /> PVC, seven two--inch PVC, and two four-inch PVC pipes. <br /> The bottom two inches of the trench will be <br /> backfilled with sand. The pipes will then be laid in the trench <br /> and sand will be placed to a total depth (from the bottom) of <br /> eight inches, and compacted by tamping with vibratory equipment. <br /> The remainder of the trench will be backfilled with Class II <br /> aggregate baserock and compacted to a minimum of 95 percent <br /> ' relative compaction*, to within four inches of final grade. A <br /> four-inch-thick asphalt layer will then be placed and compacted <br /> in the trench to match existing grade except that concrete will <br /> * Relative compaction refers to the in-place dry density of <br /> soil expressed as a percentage of the maximum dry density of <br /> the same soil determined by ASTM D1557-78 laboratory test <br /> procedure. Optimum moisture is the water content that <br /> corresponds to the maximum dry density. <br /> 27 <br />