ARCHIVED REPORTS XR0009946 - Laserfiche WebLink

Home Browse Search

i n Mr Kyle Christie Project 0805-114 04 January 29, 1996 Page 4 The system currently has been operating --with VW-5, VW-7, VW-9, and VW-12 closed (see Table 3) The air sparge system was not operational in conjunction with the SVE system during the fourth quarter 1995 due to a faulty sparge blower EMCON performed monthly site visits during October and December 1995 to evaluate and optimize system performance Copies of the field data sheets are presented in Appendix C Percentage Uptime The remediation system was shut down for two months during the fourth quarter to evaluate system performance and alternate.es The remediation system was shut down on October 6 December 15 1996. Therefore, the remediation system was operational for approximately 23 percent during the quarter Concentrations and Flow The average flow through the system was 10 cubic feet per minute (cfm) at an average applied vacuum of 16 inches of water column (see Table 4) The low flow rate is due to high influent concentrations and a change in combustion temperature EMCON increased . the setpoint from 750T to 850T based on manufacturing recommendations to increase destruction efficiency of the unit. The low flow rate is temporary and will be increased during the first quarter of 1996 Analytical reports and chain-of-custody documents are included in Appendix B Analytical results of influent and effluent samples collected on December 21, 1995, indicate that the system was meeting the required destruction efficiency (see Table 5) Laboratory results indicate that the soil vapor concentrations have dropped from 11,000 milligrams per cubic meter(mg/m3) in the second quarter to 1,400 mg/m3 Based on concentrations detected and an average flow rate of 10 cfm, the amount of cumulative gasoline removed through the end of the fourth quarter 1995 is approximately 16,766 pounds or 2,704 gallons The effect of the additional air sparge wells on dissolved phase hydrocarbon concentrations is not yet clear However, analytical results from the next quarter should demonstrate the effectiveness of the two additional air sparge wells Destruction Efficiency The remediation system had a TPHG destruction efficiency greater than 95 percent and 55 percent for benzene (see Table 4) The destruction efficiency for benzene is lower than the required limits, but is in compliance with condition No. 14, of the Permit to Operate, • which states that the emission rate of volatile organic compounds to the atmosphere should not exceed 40 pounds per day The maximum emissions to the atmosphere during the third quarter has been 5 5 pounds per day. SAC\N\PJ0,080508051140 4GS-95\pas 1