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27 January 2006 • AGE-NC Project No 98-0500 Page 3 of 10 2 1 SOIL-VAPOR EXTRACTION PARAMETERS/ANALYSIS The SVE system was operational between 12 September and 28 December 2005 (4`h Quarter 2005), operating for approximately 2,004 hours The SVE well network setting(number and type of wells) remained the same,while vacuum was continually optimized to Increase at the vapor wells that had significant detections of hydrocarbon vapor These included extraction wells on the eastern portion of the site with organic vapor meter(OVM) readings generally over 100 parts per million (ppm) in the extraction network The SVE system was observed weekly and monitored monthly Weekly activities included collection of soil-vapor condensate in 55-gallons drums for storage and disposal, as well as recording system operation parameters including hours of operation., system temperatures, and flow rates At each monthly monitoring event, the flow rate of extracted soil-vapor (Influent) was measured using an electrical DPT flow meter with a manual DPT flow meter to verify the electrical readings, vacuum potential was measured using a Dwyer magnehelic vacuum gauge The organic-vapor concentration was measured at the influent and effluent sampling ports using an OVM equipped with a photo- Ionization detector (PID [Thermo Environmental 580, 10 OeV, calibrated to isobutylene 100 parts per billion ppb]) • Three sets of soil-vapor samples were collected on 10 October, 25 November, and 28 December 2005 Samples were collected from the influent and effluent ports directly into Tedlar vapor bags using a vacuum chamber and vacuum pump The samples were labeled, placed in a pre-chilled cooler, and transported under chain of custody to Cal Tech Environmental Laboratories (CTEL), a California Department of Health Services(DHS)-certified analytical laboratory The samples were analyzed for • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Method 8015 Modified, and • Benzene, toluene, ethylbenzene, and total xylenes (BTEX) and methyl tertiary-butyl ether (MTBE) in accordance with EPA Method 8260B 22 SOIL-VAPOR EXTRACTION RESULTS The SVE unit operated at generally consistent operational rates during the observation period Calculated extraction flow rates ranged from 270 cfm to 400 cfm at the end of the quarter An Induced vacuum (negative pressure) of above 20 to 35 inches of water was measured in the piping between the blower and extraction wells Soil-vapor extraction data is presented in Table 1 Advanced GeoEnvironmental,Inc