Colloidal Activated Carbon for in situ Remediation of PFAS: A Review of Multiple Case Studies
This presentation reviews data from multiple field sites where colloidal activated carbon has been utilized to remediate PFAS contamination. Further important questions, including the ability to distribute the colloidal activated carbon in the subsurface, the long-term efficacy, and design considerations, will also be addressed.
Multiple field sites were treated with a single application of colloidal activated carbon to address PFAS contamination and other comingled contaminants. In each case the amendments were applied under low pressure (non-fracking) conditions using direct-push technology. Monitoring at all sites is on-going, with current data ranging from 3 months to over two years, and has included analysis of PFOS, PFOA, shorter chain PFASs, and co-contaminant concentrations.
Results from field case studies have demonstrated immediate removal of PFAS from the dissolved phase to levels below the US EPA health advisory level when treated with a single application of colloidal activated carbon. The site with the longest monitoring period has maintained its performance with PFOS, PFOA as well as shorter chain species for over two years and counting. Overall, these studies indicate that the in situ application of colloidal activated carbon offers a new strategy to address the risk associated with PFAS contamination at a low cost.