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10 June 1998 AGE-NC Project No 95-0101 Page 4 of 8 Moderate concentrations of petroleum hydrocarbons were detected in water samples collected from MW-2 between 1987 and 1989 Low hydrocarbon concentrations were detected in samples collected from MW-1, MW-3 and MW-4 during the same time frame Low concentrations of hydrocarbons were detected intermittently at the site between 1991 and 1996 Analytical results of all ground water samples are summarized in Table 4 27 GROUND WATER EXTRACTION TEST On 21 November 1994, an extended purge was performed on MW-2, using a submersible pump, to attempt to remove the impacted ground water A regenerative blower was connected to the well head and a vacuum was applied during pumping to increase well recharge Due to a limited water column of only four feet and slow well recharge, only 200 gallons of water were removed over a time period of approximately 7 hours The maximum drawdown of 4 feet was maintained throughout the ground water extraction test The application of a vacuum at the well head increased well recharge Extracted water was stored on-site in 55-gallon drums The depth-to-ground water uveas measured in each well at the site relative to the tops of the well casings during pumping The ground water depth in MW-6 decreased by 0 12 feet The lateral influence of the vacuum applied to MW-2 and possible effect on the depth to ground water was not investigated Extracted air from MW-2 was monitored for the presence of volatile organic compounds by using a photo-ionization detector (PID) pre-calibrated to isobutylene Volatile organic compounds were detected with the PID in soil gas exiting the blower at concentrations ranging from 230 to 335 ppm Near the end of the extended purge process, one soil gas sample was collected from the regenerative blower and analyzed for TPH-g and volatile organic compounds(benzene,toluene, ethylbenzene and xylenes, BTE&X) TPH-g was detected in the soil gas sample collected from MW-2 at a concentration of 3,600 molar ppm Analytical results are summarized on Table 5 The ground water extraction test was summarized in the Quarte]ly Report -November 1994 prepared by GAS 2 8 LIMITED VAPOR EXTRACTION TEST - UST AREA On 22 November 1994, a limited vapor extraction test was performed on the piping installed under the USTs located on-site A regenerative blower was connected to the piping outlet and used to extract air from the piping for approximately 90 minutes Extracted air was monitored for the presence of volatile organic vapor using a PID One air sample was collected from the regenerative Advanced GeoEmaronmenta[,Inc