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1 <br /> r25 February 2005 <br /> . AGE-NC Protect No 01-0827 <br />' Page 3 of 10 <br />' In September 1993, four additional soil borings, boring B 14 thought B 17 were established on the <br /> site Boring B 14 was completed as monitoring well MW-5 at a location 100 feet west of well MW-1 <br /> and the former UST excavation Boring B15 was established inside the truck bay of the building, <br /> north of the former UST excavation Additionally, boring B 16 was completed as vapor well VW-4 <br /> and boring B17 was completed as duel-screened vapor well VW-5 During January 1994 a second <br /> SVE remediation feasibility pilot study was conducted on the site,on well VW-1 and VW5 During <br /> October 1994, a third SVE remediation feasibility pilot study was conducted on well VW-1 Based <br /> on the pilot tests,the 1994 Final Remediation Plan included justification for the use of ground water <br /> extraction and soil vapor extraction for site remediation <br /> In November 1998, based on a new November 1998 directive the EHD, a fourth SVE remediation <br /> feasibility pilot study and an in-situ air-sparging(IAS)pilot study were conducted on the site,at well <br /> VW-5d However, the sparge test indicated a defective grout seal in well VW-2, the upper screen <br /> of the well VW-2 was later abandoned with grout The SVE pilot test was conducted at vapor well <br /> VW-I for 1 5 hours <br /> In April 1999,an full scale IAS pilot study was conducted on the site The IAS pilot test was unable <br /> . to produce air-flow into the subsurface at monitoring well MW-1 and therefore was terminated Also <br /> Iin April 1999, a fifth SVE remediation feasibility pilot study was conducted on vapor well VW-1 <br /> for 2 hours <br /> In June 1999, an additional full scale in-situ air-spargmg pilot study was conducted on the site <br /> without a positive result and therefore the test was terminated at 80 minutes <br /> In January 2000,a feasibility study including justification for the use of in-situ air spargmg and soil <br /> vapor extraction for site remediation was submitted to the EHD Additionally, a second Final <br /> Remediation Plan dated 02 April 2000 was submitted to the EHD Both of the proposals for site <br /> remediation were approved by the EHD <br /> 23 SITE REMEDIATION PROGRESS <br /> The site is presently being remediated by procedures outlined in Design Plans and Specifications For <br /> Soil and Groundwater Remediation, prepared by ATC Associates Inc (ATC) and approved by the <br /> EHD by letter dated 03 January 2001 <br /> A soil vapor extraction/in-situ air sparging system was installed during August and September 2001 <br /> The operation of the IAS system has produced only minor volatilization of the dissolved <br /> hydrocarbons in the deep ground water well samples at the site (VW-2D), but has reduced the <br /> dissolved hydrocarbon concentration in the shallow well samples (MW-1 and VW-1)as well as the <br /> IAdvanced GeoEnvironmentai,Inc <br />