A thin layer of soils immediately beneath the surface consiste of sands, silts and clays likely a mixture of imported and native soils used as fill material. Beneath the fill are native soils derived from its underlying bedrock. Weathered volcanic sediments are encountered beneath the native soils ranging from approximately 5 ft to 20 ft below grade (bg). Ground water is approximately 20 ft. bg.
PCE concentrations in the soils near the source area ranged from 1500 mg/kg to 2900 mg/kg. Concentrations in the ground water ranged from 1,200 ug/L to 69,000 ug/L.
No technologies selected.
 Chemical Oxidation (In Situ)
Comments:
The C-Sparge process, which uses ozone as an oxident, was used in four injection wells.
New or experimental technology: No
Remediation Goals:
Site currently categorized under a technology impracticability waiver: No
1.) The injection of ozone-containing microbubbles into fractured rock proved effective for HVOC reduction.
2.) Following injection, concentrations in the treatment wells rose briefly then decayed exponentially over a period of 11 months reaching an equilibrium between 30 and 280 ppb.
3.) The observed mean removal rate was over 99% on a mass removal basis.
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