Laserfiche WebLink
Treatability Study Report and Feasibility Evaluation for <br />In Situ Petroleum Hydrocarbon Remediation <br />Field Maintenance Shop #24, 8020 South Airport Way <br />Stockton, California <br />• Helium concentrations measured in well FMS-SVE1 (7.95 feet from the injection well) <br />increased to 42,000 ppmv (4.2%) by the end of FMS-AS1 B testing. <br />Helium was not detected in wells FMS-MW1, FMS-MW2, or FMS-MW4 during air sparge <br />testing. <br />Based on the data above, helium was confined to approximately 34 feet from the test wells. <br />Helium monitoring results were recorded on field data sheets and are summarized in Pilot Test <br />Summary Data sheets in Appendix F. <br />4.3.4. Depth to Water Monitoring <br />Depths to groundwater were monitored in wells FMS-MW1, FMS-MW2, FMS-MW4, FMS-MW5, <br />FMS-DPE1, and FMS-DPE2 before, during, and after each test. Minimal mounding occurred <br />during air sparge testing at well FMS-AS1A. The maximum change in depth to groundwater <br />during testing of well FMS-AS1A was measured in well FMS-MW1, located 98.50 feet from the <br />injection well. The water levels in well FMS-MW1 increased 0.1 feet over the course of <br />FMS-AS1A testing. <br />Air sparge testing at well FMS-AS1B generated notable mounding in wells FMS-MW1, <br />FMS-MW4, FMS-MW5, FMS-DPE1, and FMS-DPE2. The following decreases in depth to water <br />(mounding) were recorded before and during testing of well FMS-AS1 B: <br />• Water levels in well FMS-DPE1 (16.95 feet from the injection well) increased by 0.776 feet <br />after 2 hours of sparging. <br />• Water levels in well FMS-MW5 (20.05 feet from the injection well) increased by 0.674 feet <br />after 2.5 hours of sparging <br />• Water levels in well FMS-DPE2 (34.25 feet from the injection well) increased by 0.520 feet <br />after 2.5 hours of sparging. <br />• Water levels in well FMS-MW1 (98.80 feet from the injection well) increased by 0.285 feet <br />after 3 hours of sparging. <br />• Water levels in well FMS-MW4 (172.45 feet from the injection well) increased by 0.130 feet <br />after 6 hours of sparging. <br />Significant groundwater mounding may indicate AS influence since the rise in groundwater <br />levels is attributable to the addition of air into the saturated zone at that location. Depths to <br />water are plotted over time in Graph 2, showing the influence of air sparging during the duration <br />of testing at FMS-AS1A and FMS-AS1 B. <br />Depths to water are summarized in the Pilot Test Summary Data sheets in Appendix F. <br />4.3.5. Dissolved Oxygen Monitoring <br />Dissolved oxygen concentrations were recorded at 30-second intervals before, during, and after <br />testing using the Troll® 9500 multi-parameter groundwater quality monitor including an optical <br />dissolved oxygen probe installed in wells FMS-MW1, FMS-MW5, FMS-DPE1, and FMS-DPE2. <br />Air sparging at well FMS-AS1A did not cause significant increases in dissolved oxygen in <br />nearby wells. Prior to air sparging, well FMS-DPE1( approximately 17 feet from the injection <br />wells) was depleted of dissolved oxygen (baseline reading of 0.00 mg/L). Within approximately <br />2 hours of air sparging at well FMS-AS1 B, the dissolved oxygen measured in well FMS-DPE1 <br />OTI E <br />24 <br />