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PVC piping, and the engine-blower unit withdraws air and <br /> hydrocarbon vapors from soil pore space. Remedial well VW-1 is a 2- <br /> inch diameter well completed with slotted PVC from 55 to 25 feet <br /> below surface grade. A DOT-approved drum is connected in-line <br /> between the engine and the well to separate the water vapor before <br /> the hydrocarbons are introduced to the engine. The vapors are drawn <br /> into the combustion system and mixed with air through an automated <br /> oxygen sensor and fuel control module (IMPCO model FCP-1) to ensure <br /> the optimal air-fuel ratio. Combusted gases enter a three-way <br /> catalytic converter for further destruction, reducing the <br /> hydrocarbon, carbon monoxide, and nitrous oxides by more than 75%. <br /> Engine exhaust temperature averages about 7000 F, catalyst <br /> temperature averages 1, 000° F, and stack exhaust temperature <br /> averages 600° F. <br /> During the test, groundwater monitoring wells MW-1 and MW-2 will be <br /> sealed with PVC caps, and a magnahellc will be used to measure <br /> vapor pressure in these wells. If the radius of influence of the <br /> extraction well (VW-1) exceeds 30 Feet, a drop in pressure will be <br /> observed in MW-1 . <br /> The test is expected to last between 8 and 12 hours. During that <br /> time, vapors from the extraction well will be monitored at 30- <br /> minute intervals with a portable photo-ionization detector <br /> (Thermoenvironmental Instruments model 580A) to provide baseline <br /> data on vapor concentrations, and a vapor sample may be collected <br /> for laboratory analysis. <br /> i <br />