Laserfiche WebLink
04 January 2002 <br /> AGE-NC Project No 95-0173 <br /> Page 3 of 8 <br /> MW-1, MW-2, MW-3, AW-1, AW-2, AW-3, AW-4, AW-5, AW-6 and AW-7 SVE and IAS <br /> procedures for the site were described in Remedial Action Work Plan dated 30 December 1998, <br /> prepared by AGE, and approved by the PHS-EHD by letter dated 20 April 1999 <br /> D <br /> 3 1 REMEDIATION SYSTEM PROCEDURES <br /> Between 01 July 2001 and 30 September 2001, the SVE and IAS remediation systems were <br /> continuously operational at the site The SVE system utilized a Solleco Ecat 250 catalytic converter <br /> vapor extraction system The SVE system consisted of two-inch diameter, schedule 40 PVC piping <br /> installed underground from each well-head at wells VW-1, VW-2, VW-3,VW-4, VW-5,VW-6 and <br /> VW-7 and connected to the inlet of the Solleco Ecat 250 vacuum blower, the outlet from the vacuum <br /> blower was routed through the catalytic converter Induced vacuum was measured utilizing a <br /> Magnehelic vacuum gauge attached to the inlet of the blower, SVE air flow was monitored using <br /> a Dwyer DS-200 flow sensor The flow rate was determined from the measured differential pressure <br /> and the piping diameter using a nomograph(Appendix B) The SVE air flow along the influent and <br /> effluent-lines was monitored routinely for the presence of organic vapor using an organic vapor <br /> analyzer(OVA)equipped with a photo-ionization detector(PID Thermo Environmental 580A, 10 0 <br /> lieeV, calibrated to isobutylene) Sampling ports were installed upstream of the vacuum blower inlet <br /> to recover SVE influent air flow vapor stream samples, and downstream of the catalytic converter <br /> to recover effluent SVE air flow samples to monitor the efficiency of hydrocarbon destruction Field <br /> measurements were recorded at regular intervals throughout the pilot test and are summarized in <br /> Table 5, SVE performance at the site is summarized in Table 6 <br /> 3 2 COLLECTION AND ANALYSIS OF VAPOR EXTRACTION AIR FLOW SAMPLES <br /> CTI O <br /> A total of three pairs of extracted air flow vapor samples were collected from the influent and <br /> effluent of the SVE unit to measure concentrations of hydrocarbon vapor The samples were <br /> rcollected in Tedlar bags using a hand air-vacuum pump <br /> Following sample collection, the samples were placed in a covered container and transported under <br /> chain-of-custody to McCampbell 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 /> 5030/8015 Modified and 8020 <br /> r <br /> 4.0. FINDINGS <br /> rGround water elevation, flow direction and gradient were determined from field data collected on <br /> 19 September 2001, the contaminant impact to ground water was quantified from the ground water <br /> rAdvanced GeoEnviron mental,Inc <br /> r <br />