Laserfiche WebLink
2.3.3 Excavation Soil Sampling and Analysis <br /> Once the limits of the proposed excavation have been reached and to confirm any concentrations <br /> of petroleum hydrocarbons left in place, soil samples will be collected for analysis from the <br /> excavation floor and side walls. A total of eight soil samples will be collected from the side walls <br /> and two soil samples will be collected from the excavation floor. From each of the four excavation <br /> side walls, soil samples will be collected from the vadose zone at a depth of approximately 12 feet <br /> bgs and from the capillary fringe. Soil samples will be collected from the backhoe bucket in brass <br /> sleeves. <br /> The brass sleeves will be capped, labeled, packaged in an iced cooler and transported under <br /> chain-of-custody documentation to a state of California certified hazardous waste testing laboratory <br /> for analysis. Each of the soil samples will be analyzed for TPH-as-diesel, TPH-as-gasoline, BTEX <br /> and MTBE by Modified EPA Methods 8015 and 8020. <br /> 2.3.4 Site Restoration <br /> Once excavation and de-watering operations are complete, the excavation will be backfilled. The <br /> deepest portions of the excavation will be filled with %-inch rock to bridge any standing groundwater <br /> and stabilize any saturated soil. To enhance the future bioremediation of impacted soils left in <br /> place, approximately 200 pounds of bulk Oxygen Release Compound (ORC) will be mixed with the <br /> rock. The excavation will then be backfilled with clean imported soil. <br /> 2.3.5 Disposition of Excavated Soil <br /> During the excavation operations, the removed soil will be screened with a PID, segregated and <br /> stockpiled on site. Any clean overburden soil will be stockpiled separately from the stockpile of <br /> impacted soil. Each of the stockpiles will be bermed for leachate control, constructed on plastic <br /> sheeting and covered. <br /> Four soil samples will be collected from each 50 cubic yards of soil for laboratory composite and <br /> analysis. Soil samples will be collected in brass sleeves, capped, labeled and stored in an iced <br /> cooler for transport to a state of California certified hazardous waste testing laboratory. Each of the <br /> soil samples will be analyzed for TPH-as-diesel, TPH-as-gasoline, BTEX, MTBE and total lead. <br /> Depending on the specific requirements of the disposal facility, additional analytical tests may be <br /> required. <br /> 8 <br />