ARCHIVED REPORTS_XR0006018 - Laserfiche WebLink

Home Browse Search

C A M B R I A Feasibility Test Report J1MC0 Truck Plaza • 1022 Frontage Road, Ripon, California November 16, 2005 3 3 2 Hydrocarbon Vapor Measurements and Analytical Data Hydrocarbon concentration field measurements dropped from 1,010 to 940 parts per million by volume (ppmv) during the constant vacuum SVE test,and increased from 626 to 831 ppmv during the combined SVE/AS test 'Laboratory analytical results confirm that TPHg concentrations also decreased by the end of the constant vacuum SVE test from 610 to 550 ppmv Benzene was only detected at 0 17 ppmv at the beginning of the constant vacuum SVE test only No MTBE was detected during any of the testing Laboratory analytical data is presented in Table 5 and the analytical reports are included as Appendix C 3 3 3 Estimated Hydrocarbon Removal Rate Cambria calculated the hydrocarbon mass removal rate based on the vapor flow rate and P x14 hydrocarbon concentration Maximum flow rates of 1:5"cfm and 158 cfm were observed during the SVE and SVE/AS constant vacuum tests, respectively Maximum hydrocarbon mass removal rates of 22 73fpounds per day (lbs/day) and 39 77 lbs/day were observed during the SVE and SVE/AS constant vacuum tests, respectively Approximately I pounds of hydrocarbons were • removed during the two days of the feasibility testing 4.0 FEASIBILITY TEST EVALUATION Cambria evaluated the vapor flow rates, hydrocarbon concentrations, hydrocarbon mass removal rates and estimated vacuum ROI Dissolved oxygen concentrations in the observation wells were also reviewed in evaluating air sparging portion of the feasibility test, however there was no conclusive data a3 V m During SVE testing, high vapor flow rates (-120 cfm) and hydrocarbon mass removal rates (.30' 1/1 7/0 t' lbs/day) were measured and a large vacuum ROI (-75 ft) was observed (Figure 3) Hydrocarbon concentrations exhibited a decreasing trend during the SVE constant vacuum test,�iggesting that the remaining hydrocarbons may be of limited extent and/or quickly remediated "Hydrocarbon concentrations exhibited an increasing trend during the first step of the combined SVE/AS test which suggests that air sparg►ng was stripping hydrocarbons from the impacted groundwater ^ 7� During SVEIAS testing, the hydrocarbon mass removal rate increased from 29 to 39 lbs/day Based on the favorable flow rates, vacuum ROI, and mass hydrocarbon mass removal rates, SVE/AS appears to be an effective remedial technique to remediate hydrocarbon impacted vadose zone and saturated zone beneath the site 9