Laserfiche WebLink
1 27 October 2003 <br /> • AGE-NC Project No 98-0450 <br />' Page 16 of 17 <br /> ' ionization detector PID(Thermo Environmental 580B, 10 OeV, calibrated to isobutylene 100 parts <br /> per billion) <br /> tThree sets of soil-vapor samples were collected during the rebound response analysis The samples <br /> were collected in Tedlar vapor bags using a vacuum pump attached to the effluent stream sample <br /> ports These samples were labeled, placed in a pre-chilled cooler and transported under chain-of- <br /> custody to McCampbell Analytical Laboratory Inc (MAI)of Pacheco,California The samples were <br /> analyzed for <br /> ' • Total petroleum hydrocarbons as gasoline(TPH-g)in accordance with EPA Method 8015C <br /> Modified and <br /> • Benzene, toluene, ethylbenzene and xylene in accordance with EPA Method 8021B <br /> Extraction flow rates were measured in the range from 60 to 65 cubic feet per minute (cfm) An <br /> induced vacuum of approximately 25 inches of water was typically measured in the piping between <br /> the blower and extraction wells Utilizing a PID,hydrocarbon concentrations were measured in parts <br /> per million(ppm)during the analysis at the SVE inlet PID measurements ranged from 42 ppmv to <br /> ' 47 ppmv Hydrocarbon concentrations (TPH-g) were detected in three influent soil-vapor samples <br /> at concentrations of 940 µg/1 at start-up (09-02), 630 µg/1 after 24-hours(09-03) and 140 µg/1 after <br /> ' 14 days (09-18) The results of the laboratory analysis are summarized in Table 5 <br /> The laboratory reports(MAI Report Numbers 0309033,0309059 and 0309364)Quality Assurance <br /> ' and Quality Control (QA/QC) reports and chain-of-custody forms are included in Appendix E <br /> ' 7.0. SUMMARY AND CONCLUSIONS <br /> Based upon data collected from the site, AGE concludes <br /> • Hydrocarbons were detected in soil-vapor samples collected at the SVE unit at <br /> concentrations considered to be successful A total of 6,496 kilogram, 14,326 pounds or <br /> ' 2,326 5 gallons of gasoline were removed over the SVE operation, with a minor rebound <br /> occurring during the final sampling events <br /> • During the final sampling event the dissolved hydrocarbon concentrations in ground water <br /> -were defined to on the site and the dissolved MTBE was detected in monitoring well MW-5 <br /> at a concentrations near the Primary Maximum Contaminant Levels (MCL) for dnnking <br /> water, with the low detection of MTBE in two grab, ground water samples down-gradient <br /> of the site (Figure 7) <br /> 1 <br /> Advanced Geo Environmental,Inc <br /> 1 <br />