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IF v A S S O C I A T E S I N C air sparge off-gas, to determine short-term volatile organic compound (VOC) flux rates, and to collect data to design an vapor extraction/air sparge system On the first day, a vapor extraction test was performed by ATC using vapor well V W 1 as the vapor extraction point while monitoring vacuum response in the surrounding wells, MW1, MW2, ' MW3, MW4, MW6, and VW2 (Figure 2) The test was approximately 4 hours length Flowrates, applied vacuums, influent and effluent VOC concentrations, and temperatures were ' also monitored during the test Vapors were extracted using an internal combustion (IC) engine equipped with a 5-hp blower and a moisture knockout chamber Two influent vapor samples - were collected during the test, one after 15 minutes of operation an s ' operation An effluent vapor sample was collected after 3 5 hours of operation Samples were �J submitted under chain-of-custody to Sequoia Analytical (ELAP #1624) and analyzed for TPHg and benzene, toluene, ethyl benzene, and xylenes (BTEX) On the second day, the first pilot test involved ELTar only, with no vapor extraction Well MW1 was used as the air injection point Prior to the test, a groundwater sample was collected ' from well MW1, the infection point, and a vapor sample was collected from well VW1, the closest observation well An air compressor capable of producing flows up to 10 cubic feet 12er minute (cfm) was used to pressurize the well casing to 10 pounds per square inch (psi) ATC mi is ize a airflow at 4 0 cfm and the pressure in the well was 10 psi After 30 minutes of operation, helium was added to the airflow at 2 0 cfm and 17 5 psi Helium is used as a tracer in groundwater to aid in the determination of an effective radius of influence for air sparging The ' pressure in the well was reduced to 8 psi and the air sparge test continued for approximately one hour Helium measurements were taken from nearby wells to determine if helium was detected ' After the air sparging only phot test was completed, a groundwater sample was collected from well MW1, the infection point, and a vapor sample was collected from well VW1, the closest observation well Samples were submitted under chain-of-custody to Sequoia Analytical and analyzed for TPHg and BTEX Following the air sparge test, a combination pilot test was conducted Vapor extraction test ' equipment (an IC engine) was set up on vapor well VW1 Vapor extraction was conducted in conjunction with a second air sparge test on well MWI The test was approximately 2 hours in length ATC initialized the airflow at 4 0 cfm and helium was added to the airflow at 2 0 cfm --Tlr'pressure in the well was reduced to 8 psi and the combination pilot test continued for approximately one hour Helium measurements were taken from nearby wells to determine if helium was detected Flowrates, applied vacuums, influent and effluent VOC concentrations, and temperatures were also monitored during the test Vapors were extracted using an IC engine equipped with a 5-hp blower and a moisture knockout chamber After the combination pilot test was completed, a groundwater sample was collected from well MW1, the infection point, and a ' vapor sample was collected from well VWI, the extraction well Samples were submitted under chain-of-custody to Sequoia Analytical and analyzed for TPHg and BTEX 1 W%625961reportslp1Iotcap doc 5