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a i from vertical to a total vertical depth of 20 feet Boring AS-1 was drilled to a depth of 38 feet Boring P-1 was dual-completed as a 4-inch diameter vapor extraction well (VE-1) and a 2-inch diameter in-situ air sparging(IAS)observation well(ASO-3) Boring P-2 was completed as ASO-1, an IAS 2-inch diameter observation well from 17 to 27 feet Boring P-3 was dual-completed as extraction well VE-3 and IAS observation well ASO-2 Boring P-4 was completed as extraction well VE-2 using 4-inch diameter Boring AS-1 was completed as an IAS mj ection well from 28 to 38 feet SOIL VAPOR EXTRACTION/IN-SITU AIR SPARGING PILOT TEST On January 14, 1995, a 24-hour soil vapor extraction(SVE)and in-situ air sparging(IAS)pilot test was conducted for additional SVE planning The vacuum extraction system consists of a vacuum pump driven by an internal combustion (IC) engine The vacuum pump is then connected to an extraction well (in this case, VE-1) System start-up procedures were initiated at approximately 14 January 1995 and was shut down at approximately on 15 January 1995 Vacuum gauges were attached to each of the vapor extraction observations wells, as well as MW-1, MW-3, MW-4 and VW-1 Measmements were recorded at regular intervals throughout the test A total of six air samples were collected from the inlet of the extraction well to measure extracted hydrocarbon concentrations Air sparging was performed by injecting air,via a 12 psi compressor integrated into the SVE system,beneath the groundwater table at a depth of approximately 28 feet The well(AS-1) was designed to provide an air-tight seal in order to force the infected air into the formation Groundwater depths, air pressure and dissolved oxygen were measured in each of the observation wells at several intervals during the test Groundwater samples were collected from the sparging observation wells at the termination of the test to measure changes in hydrocarbon concentrations SOIL VAPOR EXTRACTION/ATR SPARGING FEASIBILITY Between 22 and 40 inches of water vacuum was maintained at VE-1 throughout the pilot test The induced vacuum was measured in VE-2, VE-3, VW-1, ASO-1, ASO-2, MW-3 and MW-4 The greatest vacuum measured in the vapor extraction observation wells was 2 4 inches, at well VE-3, located approximately 15 feet northeast of VE-1 However, after three hours of the test, a vacuum of 0 02 inches was measul ed in MW-3, more than 90 feet east of VE-1 Concentrations of TPH in the extracted vapors ranged from 35,000 gg/L to 56,000 gg/L Converting these values to parts per mi Ilion volume(ppmv),concentrations ranged from 9,800 ppmv (at 6 hours) to 15,680 ppmv (at 12 hours) Generally, a vacuum of 0 10 is required to successfully volatilize subsurface hydrocarbons The maximum vacuum measured at each well was plotted versus the distance of each well from the extraction well Drawing a "best fit" line through the three data points will determine the effective radius of influence at this site,the effective radius of influence at the site appears to be approximately 37 feet It appears that vapor extraction, using an IC engine, would successfully remove a significant volume ofpetroleum hydrocarbons from impacted soil atthe site Furthermore,it is likely that extraction on VE-2 (slant boring)will have apositive influence on impacted soil in the vicinity of MW-3 Advanced GeoEnwronmentai,Inc