EHC® in situ integrated biological and chemical reduction (ISCR) technology was used to treat chlorinated aliphatic hydrocarbons (CAHs) safely, rapidly, and effectively at a manufacturing facility.
North Carolina, USA
The key CAHs found in groundwater at the site included 1,1,2,2 TeCA, TCE, and CF, as high as 350, 1,100, and 1,500 ppb respectively. At this site, EHC was modified with carbonyl iron powder and was injected at the site through hydraulic fracturing.
Eleven weeks after injection, concentrations of TeCA, TCE, and CF were reduced by 86%, 98% and 66%, respectively. After approximately 26 months, these compounds in the same well were reduced over 98%.
As featured in Remediation Journal, EHC Reagent was injected via direct push across the source area. Site specific challenges included a low permeability clayey lithology and a large degree of CVOC mass sorbed at the smear zone due to large variations in the groundwater table.
EHC was injected into a series of permeable reactive barriers (PRBs) across the plume with the goal to treat the entire plume area over time. After only 6 months CT concentrations were reduced by 99.7%, with all monitoring wells meeting the groundwater clean up criteria.
The EHC® PRB was installed as a line of direct push injection points across the width of the plume. Twelve years after the installation the PRB is still supporting >90% reduction in inflowing CT concentrations and the downgradient plume has reduced significantly in size and concentration.
As featured in Remediation Journal, EHC® Reagent and KB-1® Bioaugmentation Culture were injected across the highest concentration area from approximately 40 to 112 ft bgs using direct push. Prior to treatment dissolved phase concentrations ranged as high as 592,000 and 90,000 μg/L for TCE and cis-DCE, respectively.
As featured in Remediation Journal, EHC Reagent was emplaced via hydraulic fracturing into fine-grained sandstone to remediate TCE in groundwater.