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' A Solleco catalytic-oxidation soil vapor extraction (SVE) unit began operation at the site in • December 2000. The system was monitored monthly'during operation and after re-start events. During each monitoring event, the SVE flow rate, vacuum (potential) and concentrations of '. hydrocarbons in the extracted soil-vapor were measured and a set of soil-vapor samples were collected by AGE personnel. The unit operated at an average extraction flow rate,of 85 and 90 standard cubic feet per minute (cfin). A compressor-based EnviroSparge 1AS system was installed at the site in August 2001. The IAS system delivered 6 cfm at a pressure of 10 pounds per square inch,adequate to displace the static water within each sparge well.In addition,the dissolved oxygen ' in-the ground water wells was measured to monitor the efficiency of the IAS system. Elevated concentrations of dissolved oxygen were periodically detected in monitoring wells used as ' observation wells within and outside the IAS network on the site. The highest dissolved oxygen value measured in well MW-1 was at 12.1 %and in well MW-2 was at 20.8%. Generally,dissolved oxygen concentrations measured in the wells remained stable at/or sporadically increased above pre- remedial levels. Sparging rates were measured at approximately 6 scfm during each monitoring event. A pressure of approximately 10 psi was maintained for the air sparging flow rate. The estimated mass of hydrocarbons removed was based on laboratory analysis of soil-vapor samples. The mass of extracted hydrocarbons was calculated for each time period using average t hydrocarbon concentrations of influent soil-vapor sample data and average air flow rates. A total of 2,122.45 kg (4,229.12 lbs), or a volume of 748.5 gallons hydrocarbons as gasoline was removed between December 2000 and December 2003. During this period, the petroleum-hydrocarbon concentrations have declined to the point where utilizing the unit was no longer cost effective in terms of the remediation goals. The catalytic SVE system was replaced on 13 December 2002 with a vacuum blower and 5 5-gallon moisture collection canister. Operation of a soil vapor extraction (SVE)vacuum blower ceased in January 2004 due to malfunction of the equipment.A sample of the soil vapor from the monitoring events during the last ' quarter of 2003 was absent of detectable hydrocarbons, therefore SVE was not restarted. . CONFIRMATION SOIL AND GROUND WATER SAMPLING Based on analytical data collected from the SVE progression and the ground water wells, ! confirmation soil and ground water collected from within the area of petroleum hydrocarbon-impact at the site were required to determine if continuing remedial operation is necessary and serve to approximate remaining petroleum hydrocarbon concentrations. 1 Post Remediation Soil Sample Collection and Grab Ground Water Sample Collection tOn 14, 15 and 17 October 2003, five soil probe borings (CBI through CB5) were advanced at the site, under EHD oversight. Probe boring CB-1 was advanced adjacent to monitoring well MW-1, ' CB-2 advanced was advanced adjacent to boring B4, boring CB-3 was advanced between vapor wells VW-I and VW-11, boring CB-4 was advanced between boring B4, vapor wells VW3, VW 1 �h . Advanced GeoEnvirontnentd,Inc.