SITE INFORMATION AND CORRESPONDENCE_FILE 2

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Site Background Information: Chapin Brothers Investments, Inc. Page 3 of 19 SOIL VAPOR EXTRACTION TEST On 10 June 1994 a soil vapor extraction test was conducted at the site. A vacuum was applied to an extraction well (VW-1) and measurements of flow rate and vacuum were collected from three temporary observation wells(VW-2,VW-3 and VW-4).However,a vacuum could not be achieved on VW-1, so the internal combustion (IC) unit was connected to one of the observation wells. It appears that VW-1 may have been placed too close to the western UST excavation, which was backfilled with pea gravel,and"short circuited"the attempt to draw a significant vacuum. Despite the short circuiting of VW-1,the test concluded that vapor extraction would be a viable remediation alternative for impacted soil at the site. The data collected during the pilot test indicated that sufficient flow and hydrocarbon recovery rates can be achieved at the site. ADDITIONAL ASSESSMENT OF HYDROCARBON IMPACTED SOIL AND REMEDIATION INSTALLATION From 03 to 05 January1995,a total of five soil borings were drilled at the site. The borings P-1,P-2 and P-3 were drilled to depths of 27 feet. Boring P-4 was drilled at an angle of approximately 30° 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 injection 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-l. Measurements 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 ground water 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 injected air into the formation. Groundwater depths, air pressure and dissolved oxygen were measured in each of the observation Advanced GcoEnNironmcntal,Inc.