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T APPENDIX B VAPOR EXTRACTION TEST PROTOCOL Following is a general description of the vapor extraction test protocol and data acquisition procedures TEST PROTOCOL One extraction well is connected to the V.R Systems internal combustion unit, at least two other vapor extraction/monitoring wells are used as pressure drawdown observation points. During a senes of tests, it is typical that a particular well will function both as an extraction well and an observation well While air is extracted, the pressure Ievel in the observation wells is monitored and recorded. Data are recorded as net drawdown from the initial soil air (atmospheric) pressure within the sealed well casing Each test is conducted until vacuum effects nearly stabilize at the farthest observation point. Pressure drawdown data are then used in a modeling analysis to estimate soil air transmissibility These parameters are necessary to determine the effective area of influence. PRESSURE MONITORING Suction pressure was recorded with a magnehelic gauge fitted at the influent end of the blower to determine air flow rate; well caps fitted with magneheIic pressure gauges with sensitivity levels ' as low as 0 01 in H20were used to record the pressure drawdown data from the observation wells. AIR FLOW RATE The air flow rate is obtained from the VR System internal combustion unit. ' VAPOR EXTRACTION TEST EQU P..MF-NT The vapor extraction test equipment used is the V R Systems Model Number V3 The system uses an internal combustion engine (Ford 460-cubic-inch 4-cycle engine). The system extracts vapor using the vacuum created by the engine The extracted vapors are mixed with a separate - fuel source (propane) and combusted in the engine If the well effluent vapor concentrations are Higher than 40,000 ppm-Cd, propane is not required as an additional fuel source.