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26 October 2011 <br />AGE-NC Project No. 02-0926 <br />Page 2 of 4 <br />(OVM) equipped with a photo-ionization detector (PID: Thermo Environmental 580B; <br />10.0 eV; calibrated to isobutylene), and 3) influent soil vapor and effluent vapor stream <br />samples were collected from sampling ports installed upstream (influent) of the SVE <br />vacuum blower and downstream (effluent) of the SVE GAC vessels and submitted for <br />laboratory analysis. Field SVE measurements were recorded at regular intervals and are <br />summarized in Table 1. Analytical results of SVE air flow samples are summarized in <br />Table 2. SVE performance data is summarized in Table 3. <br />2.2. COLLECTION AND ANALYSIS OF SVE SAMPLES <br />A total of two sets of extracted SVE samples were collected on 11 July and 09 August <br />2011 from the influent and effluent ports of the thermal oxidizer/GAC vessels vapor <br />recovery system to measure concentrations of hydrocarbon vapor. Samples were collected <br />in Tedlar bags utilizing an electric air-vacuum pump. <br />Following sample collection, samples were properly labeled, placed in a covered container <br />and transported under chain of custody to CalTech Environmental Laboratories (CTEL). <br />Each sample was analyzed within 72 hours of collection for total petroleum hydrocarbons <br />as gasoline (TPH-g), volatile aromatic compounds (benzene, toluene, ethylbenzene and <br />total xylene: BTEX) and methyl tertiary butyl ether (MTBE) in accordance with EPA <br />Methods 8015M and 8260B, respectively. <br />2.3. SOIL VAPOR EXTRACTION FINDINGS <br />From field and laboratory data collected at the SVE remediation system between 06 June <br />and 09 August 2011, AGE determined the average TPH concentration, the average flow <br />rate and calculated the approximate mass and volume of hydrocarbons removed. <br />2.3.1. Soil Vapor Extraction Performance <br />Between 06 June and 09 August 2011, the SVE remediation system was operational for <br />a total of 1,532 hours. During this operational period, SVE inlet flow rates (total flow) were <br />generally observed between 79 standard cubic feet per minute (SCFM) and 81 SCFM. <br />Utilizing a photo ionization meter (PID), hydrocarbon concentrations were measured from <br />the SVE influent at concentrations as high as 65 parts per million volume (ppmv). Field <br />measurements are summarized in Table 1. <br />Advanced GeoEnvironmcntal, Inc.