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TASK 4 -CONDUCT A DUAL PHASE EXTRACTION TEST A 24-hour dual-phase extraction test will be conduced for the site This test will measure the influence of vapor extraction, as well as water removal, utilizing a liquid-ring pump capable of delivering up to 28 inches mercury of vacuum to a well containing a screened interval above and within the water bearing zone A vacuum hose equipped with a small radius stinger will be mounted on the top of the newly installed 6-inch diameter extraction well Vacuum will then be applied to the well in two ways First, vacuum will be applied through the stinger, which will be lowered into the well at a depth below the water table, thereby removing the water and creating a cone of depression Second, vacuum will also be applied simultaneously to the air within the well and newly engineered vadose zone to extract soil vapors Both vapor and water will b e transferred from the testing well into the treatment system where the vapors will be treated by thermal oxidation, and the extracted water will be stored within a large holding tank for off-site disposal The radius of vacuum influence in the vadose zone will be determined by measuring negative pressure to surrounding wells Radius of influence in groundwater will be determined by measuring the changes in groundwater elevations in both the extraction well and surrounding monitoring wells and piezometers Only manual water level measurements will be used during this test Vapor samples will be collected from the extraction well in Tedlar bags at the beginning of the test and at 240 minute intervals throughout the duration of the test These samples will be analyzed for TPH-G, BTEX a n d oxygenates by EPA Method 8260 The data will allow ASE to determine 1f this type of system is capable of capturing/recovering hydrocarbons in soil and groundwater in the affected area, and will also provide ASE the ability to appropriately design such a system should it be found to be practical TASK 5 -INSTALL AN AIR SPARGING WELL In order to conduct an air sparging test, an air sparging well will have t o be constructed This well will be placed near monitoring well MW-5 The well will be constructed using a drill rig equipped with 8-inch diameter hollow-stem augers The well will be constructed within the hollow stem • augers using 2-inch diameter flush-threaded, schedule 40, 0 020-inch slotted PVC well screen and blank casing The well will be screened between approximately 17 and 19-feet bgs The well casing will b e Frank's One Stop Workplan — June 2000 -19-