FeroxSM Technology Demonstration at Hunter’s Point Navy Yard
In December of 2002, ARS successfully completed the field application of FeroxSM at Hunters Point Navy Yard in Northern California adjacent to San Francisco Bay. The technology demonstration was selected under the US Navy’s Alternative Restoration Technology Team program. which evaluates innovative remediation technologies to expedite regulatory process and implementation at Navy and Marine Corps sites.
The objective of the project was to evaluate the applicability of the technology to address source contamination at this and other sites across this military facility, which is to be turned over for civilian use within the near future.
TCE, the target compound, was detected at concentrations as high as 80 mg/liter in the groundwater. Other than the high levels of contamination, the site setting and geology also presented particular challenges to the implementation of the technology. The treatment zone resides beneath a warehouse building and extends vertically across a fill layer and the underlying weathered bedrock. The thickness of the fill material, depth to the bedrock and the degree of weathering vary greatly within the treatment area.
The ARS field team had to adjust the injection parameters frequently in response to the characteristics of different injection zones. Approximately 16,000 pounds of ZVI powder was distributed across the treatment area via four injection points. Field observations and data showed significant coverage of the injected iron.
Preliminary groundwater sampling data three weeks after the injections shows anticipated changes in the groundwater geochemical parameters which in turn reduces the target TCE.
Based upon groundwater sampling within and around the pilot test area, target TCE levels have decreased by greater than 97%. In the well exhibiting the highest baseline concentration of TCE (88,000 ppb), ground water concentration levels of TCE were measured during the third round sampling event to be 78 ppb. With ground water geochemistry shifting in favor of the FeroxSM reaction, continued reduction of TCE in this DNAPL source area is expected.
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