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PID readings (Table 4) measured in VE-1 show a steady increase in extracted VOC iconcentrations during the pilot test A graph presenting the VOC concentrations versus vacuum (Appendix F) shows an increase in VOC levels with increasing vacuum The off-gas analytical results showed a TPH(g) concentration of 86,000 ug/L, a benzene concentration of 2,800 ug/L, and a total BTEX concentration of 11,160 ug/j, Based on the analytical results, approximately 15 4 pounds of hydrocarbon vapors per hour(lbs/hr) were extracted from VE-1 A copy of the analytical report is included in Appendix G ' Air Sparge Test ' The air sparge test was performed on injection well IAS-1, located near the former UST excavation source area Existing monitor wells MW-1,MW-4, MW-13, and MW-13A and newly installed dual completion well VE-2 were used as observation wells during the test The ' momtonng points were selected to provide multi-directional data at varying distances from the injection point ' The pilot test involved injecting air into the saturated zone through the injection well using an Emglo Model M800HC4V compressor with a maximum flow rate of 4 9 cfm The pilot test was operated at a pressure of 4 pounds per square inch (psi) Observation wells MW-1, MW-4, MW- 13, and MW-13A were monitored for pressure influence, VOC concentrations, dissolved oxygen content, and depth to water(Table 5) Dual completion well VE-2, a vadose zone well, was monitored for pressure responses and VOC concentrations only(Table 5) Pressure readings ' were measured with a magnehelic gauge, VOC concentrations were measured with a photionization detector(PID), dissolved oxygen concentrations were measured with a YSI Model 55 meter, and water levels were measured with a Solinst gauging probe The air sparge test was evaluated through each of the monitored parameters indicated above Pressure responses were measured in three observation wells (MW-13,MW-13A, and VE-2) ' Observation well VE-2 was installed as a dual completion vapor extraction well monitoring point with a screen section that does not extend into the saturated zone The pressure response data from this well was not used in determining the radius of influence of the sparge test A graph ' presenting the natural log of the pressure versus distance from injection well IAS-1 (Appendix F) shows a maximum radius of influence of approximately 10 feet (MW-13) A pressure response of 0 1 inches w c was selected to define a sigmficant response The pressure response measured in observation well MW-13A (0 02 inches w c), located approximately 16 feet from 1AS-1, was less than 0 1 inches w e 40'J ct aP �r Increases in VOC concentrations were measured in three observation wells (MW-13, MW-13A, and VE-2) A graph showing VOC concentrations versus distance (Appendix F) indicates a ' maximum radius of influence of approximately 10 feet (MW-13) Maximum changes in water levels were measured in four observation wells (MW-1, MW-2, MW-13, and MW-13A) after 7 to 8 hours into the sparge test (Table 5) Using this data, a graph showing increases in water levels versus distance (Appendix F), indicates a maximum radius of influence of approximately 46 feet (MW-1) The maximum increase in water level was at 0 12 �Ll"s