In situ chemical remediation of PCE and TCE in fractured rock using a custom fine grain EHC reagent.
Industrial district of the inner northern suburbs of Melbourne, Victoria, Australia
PCE, TCE
Prior remediation efforts only temporarily reduced PCE and TCE concentrations in groundwater. Given its combined abiotic and biotic treatment effects, EHC ISCR product was identified as a remedy for the site, and the product formulation was modified for site-specific needs that emerged during the initial implementation.
Significant reductions in concentrations of target compounds was achieved in response to the EHC Fine ISCR product injections. Continued groundwater monitoring indicated that the remedy would be successful in obtaining Clean Up to the Extent Practicable (CUTEP) determination by EPA Victoria.
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.