Laserfiche WebLink
I <br />' 29 September 2000 <br /> AGE-NC Project No 95-0173 <br />' Page 3 of 7 <br />' 3 1 SOIL VAPOR EXTRACTION/IN-SITU AIR SPARGE SYSTEM PROCEDURES <br /> Between 03 April 2000 and 30 June 2000, the SVE and IAS remediation systems were operational <br />' at the site The SVE system utilized a Solleco Ecat 250 catalytic converter vapor extraction system <br /> Two-inch diameter,schedule 40 PVC piping was installed underground from each well-head at wells <br /> VW-1,VW-2, VW-3, VW-4, VW-5, VW-6 and VW-7 to the inlet of the vacuum blower, the outlet <br />' from the vacuum blower was routed through the catalytic converter A Magnehehc vacuum gauge <br /> was attached to the Inlet of the blower The air flow was monitored using a Dwyer DS-200 flow <br /> sensor The flow rate was determined from the measured differential pressure and the piping <br />' diameter using a nomograph (Appendix B) The vapor stream at the SVE Inlet was monitored for <br /> the presence of organic vapor using an organic vapor analyzer (OVA) equipped with a photo- <br /> ionization detector (PID Thermo Environmental 580A, 10 0 eV, calibrated to isobutylene) <br />' Sampling ports were Installed upstream of the vacuum blower Inlet to recover Influent soil-gas vapor <br /> stream samples, and downstream of the catalytic converter to recover effluent stream samples to <br /> monitor the efficiency of hydrocarbon destruction Field measurements were recorded at regular <br /> Intervals throughout the pilot test and are summarized in Table 4 <br />'. 32 COLLECTION AND ANALYSIS OF SOIL GAS SAMPLES <br />' A total of six extracted soil-gas vapor samples were collected from the Inlet and outlet of the <br /> regenerative vacuum blower unit to measure concentrations of hydrocarbon vapor The samples were <br /> collected in Tedlar bags using an organic vapor analyzer as an air pump <br />' Following sample collection, the samples were placed in a covered container and transported under <br /> chain-of-custody to McCarripbell Analytical Laboratory (MAL)in Pacheco, California Each sample <br />' was analyzed within 72 hours of collection for TPH-g and BTEX in accordance with EPA Methods <br /> 8015 Modified and 8020 <br />' 3.0. FINDINGS <br /> AGE determined that the ground water flow direction was locally variable at the site between <br /> northwest and southeast at an average gradient of 0 003 from the field data collected on 23 May <br /> 2000 Laboratory analysis of six ground water samples detected TPH-g and BTEX in six samples, <br />' TPH-d in five samples, MTBE in two samples and TBA in one sample <br /> • <br />' Advanced GeoEnvironmental,Inc <br /> 1 <br />