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FINAL RE]MIIA710N PLAN 14800 West Frontage Road Manteca,Callfomia 2.7 Soii Va or Extraction Test Procedure and Results A short-term sod vapor extraction test of well MW-4 was conducted onr 22 1 Octobe 992 Monitoring wells MW-1, MW-2, MW-3, and MW-5 through MW-9 (Figure 2) were used as vacuum influence monitoring points The purpose of the test was to obtain information related to the soil vapor extraction rates, sod vapor hydrocarbon concentrations, and extent of vacuum influence for design of a soil venting system ' Aortable soil venting g bl w o er was used to induce vacuum/airflow from the test wells No fresh air was artificially admitted into the system The soil hydrocarbon vapors from the test wells (blower exhaust) were discharged directly to the atmosphere The San Joaquin County Air Pollution Control District (SJCAPCD) did not require an emission control ' system The recorded airflow rate from well MW-4 ranged from 21.80 to 25 08 cubic feet per minute (cfm) at a vacuum of 65 inches of water The average airflow rate from the test well was 24 cfm per foot of open well screen at a vacuum of 65 inches of water Measurable resulting vacuum (greater than 0 01 inch water) was recorded in observation ' wells MW-1, MW-2, MW-3, and MW-6 through MW-9 located at varying distances from MW-4 No measurable vacuum was recorded for MW-5 (Table 5) Periodic sod vapor hydrocarbon concentrations from the test wells, as measured with a flame ionization detector on site, varied from 5,500 to 6,000 parts-per-million (ppm) by volume A soil gas sample was collected at the blower exhaust at the 105th minute of the test The air sample was submitted under chain-of-custody to NET Pacific, Inc , of Santa Rosa, California, a state-certified analytical laboratory The sample was analyzed for concentrations of TPH, as gasoline, by GC-FID/EPA Methods 5030/8015 and BTEX by ' EPA Method 8020 The analytical reports and chain-of-custody form are included in Appendix D Test data results are summarized in Table 5 Based on laboratory analytical results, the benzene extraction rate from MW-4 during this test was 0 12 lbs/hour, and the TPH, as gasoline, extraction was 21 25 lbs/hour Based on the hourly hydrocarbon extraction rates during the test (Table 6) and an airflow rate of 24 cfm, the initial TPH, as gasoline, and benzene extraction rates could be as high as 510 and 3 0 lbs/day, respectively Calculations for mass flow rate for TPH, as gasoline, and BTEX are included in Appendix E Results of the tests indicate soil ventingi s feasible if pursued as a soil remedial option at the site A sod venting system could be designed using MW-4 as a vapor recovery well Specific air discharge requirements under the jurisdiction of the SJCAPCD must be met when operating any remediation system that emus hydrocarbons to the atmosphere The results of the venting test indicate emissions controls would be required 90-097A FRP -5-