Laserfiche WebLink
1 <br /> EPM. <br /> 1 <br /> Mr James L Barton <br />' January 26, 2005 <br /> Page 5 <br />' Since starting the SVE system in October 1999, the SVE system has operated for a total of <br /> 6,919 hours and has removed approximately 8,699 pounds of petroleum hydrocarbons from <br /> impacted soil and groundwater <br /> A summary of SVE system operational parameters, destruction efficiencies, and mass flow <br /> rates are presented in Table 5 through Table 10, respectively <br />' Air Sparging System Status <br />' The AS system was started in October 1999 as required by CAO No 5-00-707 The AS system <br /> operation was modified to pulse-operations mode (week-on/week-off basis) in October 2003 <br /> based on the RWQCB recommendation to pulse the AS system in all aquifer zones as <br />' mentioned in the RWQCB letter dated October 23, 2003 <br /> On September 24, 2004, AS system operations were returned to continuous operation as <br /> required by CAO No 5-00-707 <br /> The AS system operation schedule was modified to week-on/week-off on December 6, 2004, <br /> based on verbal approval from Mr Jim Barton of the RWQCB <br /> The AS system has operated for approximately 14,820 hours since in situ remediation at this <br /> site began in October 1999 <br /> Effectiveness of Remediation System <br /> System effectiveness is evaluated by assessing groundwater data from monitoring wells MW-2, <br /> MW-3, MW-11, and MW-12 Concentrations of TPHg, benzene, and MTBE in groundwater <br /> samples collected from selected wells screened in Unit A or Unit B are depicted graphically on <br /> cross-section A-A' and cross-section C-C' (Attachment E) Concentrations of TPHg, benzene, <br /> and MTBE in groundwater samples collected from selected wells screened in Unit A, Unit B and <br /> Unit D are depicted graphically on cross-section B-B' (Attachment E) Graphs of TPHg <br /> concentrations, benzene concentrations, and groundwater elevation versus time are included in <br /> Attachment F <br /> Soil vapor samples were collected from selected SVE wells and monitoring wells utilized for the <br /> SVE system Samples collected during the fourth quarter 2004 were submitted to Air Toxics <br /> LTD (Air Toxics) in Folsom, California for analyses of VOCs by Modified EPA Method TO-3 <br /> Historical field screening results for VOCs in soil vapor samples collected from selected wells <br /> are summarized in Table 11 Tabular results of recent soil vapor sampling analytical results are <br /> summarized in Table 12 Copies of the laboratory analytical results with chain-of-custody <br /> documentation are included in Attachment D <br /> Based on decreasing trends in wells MW-9R, MW-10, MW-12, MW-14, MW-16, MW-17, <br /> MW-18D, MW-24S, MW-24D, and MW-25D indicate that the AS/SVE system appears to be <br /> J IProiects10694015098-2931WorkinglReports15098 4th Qtr 04-QMR doc <br /> Celebrating 35 Years of Excellence in Environmental Services <br />