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4. gW14gkot 7edwrs Inc. Page 7 Dual Phase Extraction Pilot Test Report Project No.723.2 November 5,2004 .. raised to 3 feet bgs and placed in vapor extraction mode to preclude overfilling the tank during the night. American Valley picked up one last load of water after 6:15 P.M. and returned on Monday to pick up their tank. The system was left running overnight to consume the remainder of the propane fuel. This was necessary because the propane supplier needed to have the tank empty to use their small truck-mounted crane to pick it up. 3.5 Extraction Termination On July 31`s at 9:00 A.M. (Saturday), the system was still extracting vapor from wells EW-1 and VEW-1 simultaneously. There was still excess propane left so GTI started extracting groundwater again from EW-1. The system was left in this configuration until the pilot test was terminated at 12:45 P.M. with a total of 17,392 gallons of groundwater extracted. V 4.0 DATA ANALYSIS In the following sections GTI will discuss data generated by the test that can be used to design a vapor extraction and/or groundwater treatment system for full site remediation (if necessary). 4.1 Vapor Extraction GTI monitored the soil vapor extraction process by periodically measuring vacuum pressure in wells VEW-1, VEW-2 and MW-5. The measurement data are included in Table 3. Wells �- VIEW-1, VEW-2 and MW-5 are located approximately 16, 25 and 46 feet, respectively from EW-1. As stated above, the extraction from EW-1 started on July 26th at 9:30 A.M. and the initial extraction was over 100 inches of water vacuum. The vacuum influence did extend to the locations of the monitoring points as indicated by the data in Table 3. The vacuum measured in VEW-1 started at 0.7 inches and eventually fell to 0.3 inches after -23 hours. Similarly, the vacuum influence measured in VEW-2 started at 0.83 inches and stabilized at 1.1 inches after -23 hours. Monitoring well MW-5 started at 0.82 inches of vacuum and stabilized at 0.9 inches by the time 8 hours had elapsed. Well ` MW-5 was not monitored for vacuum once the levelogger was installed after 6:00 P.M. on Monday, July 26h. The vapor extraction rate from EW-1 started at 159 cubic feet per minute (cfm). As the vacuum influence spread through preferential pathways in the subsurface the rate increased to 334 cfm after-23 hours had elapsed.