Remediation Status: In groundwater monitoring

Why the technology was selected:
Safe and cost-efficient. EHC® is a controlled-release, integrated carbon and zero valent iron (ZVI) source that yields redox potential (Eh) in the -500 to -650 mV range. This Eh is significantly lower than that achieved when using either organic materials (lactate, molasses, and sugars) or reduced metal alone. Eh potentials in this range facilitate the timely and effective removal of normally recalcitrant chlorinated organics (e.g., CT, PCE) and other persistent compounds (e.g., perchlorate) without the formation of potentially problematic intermediates, such as DCE/VC from the anaerobic degradation of PCE/TCE or CF/DCM from the anaerobic degradation of CT.

Date implemented:
January 2005

Final remediation design:
24,100 lbs of EHC were injected into the two hot spot areas, giving an EHC application rate of 0.06% to soil mass.

Results to date:
Six months following the EHC injection, TCA levels had decreased by 94% and TCE levels had decreased by 84% to 90% at the target areas without the accumulation of problematic catabolites. No air issues were identified.

Next Steps:
With an estimated life of greater than 36 months, EHC is expected to continue stimulating reductive dechlorination at this site.

Cost to Design and Implement:
The material cost of using EHC for plume treatment was $3.65/yd3

Why the technology was selected:
Safe and cost-efficient. EHC® is a controlled-release, integrated carbon and zero valent iron (ZVI) source that yields redox potential (Eh) in the -500 to -650 mV range. This Eh is significantly lower than that achieved when using either organic materials (lactate, molasses, and sugars) or reduced metal alone. Eh potentials in this range facilitate the timely and effective removal of normally recalcitrant chlorinated organics (e.g., CT, PCE) and other persistent compounds (e.g., perchlorate) without the formation of potentially problematic intermediates, such as DCE/VC from the anaerobic degradation of PCE/TCE or CF/DCM from the anaerobic degradation of CT.

Date implemented:
January 2005

Final remediation design:
24,100 lbs of EHC were injected into the two hot spot areas, giving an EHC application rate of 0.06% to soil mass.

Results to date:
Six months following the EHC injection, TCA levels had decreased by 94% and TCE levels had decreased by 84% to 90% at the target areas without the accumulation of problematic catabolites. No air issues were identified.

Next Steps:
With an estimated life of greater than 36 months, EHC is expected to continue stimulating reductive dechlorination at this site.

Cost to Design and Implement:
The material cost of using EHC for plume treatment was $3.65/yd3