ARCHIVED REPORTS_XR0011541 - Laserfiche WebLink

Home Browse Search

U-Haul#709-50 Blaes Environmental Preliminary Site Conceptual Model December 15,2006 . column (Appendix N, Tables 6 and 7) Monitoring point well MW-IA (screened from 30 to 50 feet bgs), located the furthest from the nested extraction wells (approximately 57 feet away), demonstrated a vacuum response of 100 inches and 0 80 inches for testing of VEW-1 and VEW-2, respectively Similarly, MW-IB (screened from 52 to 77 feet bgs and nested with MWA A) demonstrated a vacuum response of approximately 3 10 inches and 1 50 inches for testing of VEW-1 and VEW-2, respectively Based on monitoring point well response during the fourth step of each test, an estimated effective VE ROI of greater than 60 feet exists at the site (Appendix N, Figure 6) The induced vacuum versus lateral distance from VEW-1 and VEW-2 is graphically presented in Appendix N, Figures 7 and 8, respectively 4.6.1 Mass Extraction Estimates Laboratory analysis of the vapor samples collected during the VEW-1 (lower soil horizon) test indicated volatile fuel hydrocarbons (VFH) were extracted at concentrations of approximately 28,000 ppmv Additionally, BTEX concentrations were present at concentrations of 1,200 ppmv benzene, 1,900 ppmv toluene, 200 ppmv ethylbenzene, and 710 ppmv total xylenes, respectively Analytical results of soil vapor extracted during the VEW-2 (upper soil horizon) test indicated concentrations of approximately 17,000 ppmv VFH, 430 ppmv benzene, 1,500 ppmv toluene, 140 ppmv ethylbenzene, and 640 ppmv total • xylenes The vapor sample laboratory analytical results are summarized in Appendix N, Table 8 Based on the data collected from the VEW-I and VEW-2 tests, the anticipated removal rate of volatile fuel hydrocarbons during initial remedial system start up (with an estimated average influent concentration of approximately 22,500 ppmv and a flow rate of approximately 345 cfm into a thermal oxidizer) would approach approximately 2,800 pounds of hydrocarbons removed per day However, the preceding calculation does not take into account the necessity of adding dilution air to a thermal oxidizer in order to regulate and optimize the system Therefore, the actual removal rate may be lower Based on the VE test results, a remedial system incorporating VE would be an effective treatment technology for the remediation of petroleum hydrocarbon impacted soil beneath the site 4.7 AQUIFER PUMP TEST RESULTS On November 20 and 21, 2002, Blaes Environmental conducted two limited aquifer pump tests at the site The objective of pump testing was to collect data necessary to evaluate the feasibility of extracting water from individual wells for above-ground treatment The pump tests were performed on groundwater monitoring wells MW-6C (screened from 70 to 90 feet bgs) and MW-3C (screened from 75 to 100 feet bgs) (Figure 3) Groundwater was purged from each well using a 0 5 horsepower MPI Grundfos pump Page 19