A research team, with funding from the Department of Defense (DoD)1, developed a planning-level instrument for rapid estimation of the longevity of colloidal activated carbon (CAC) barriers.2 It provides a low-resolution, quick way to estimate CAC barrier longevity compared to existing numerical models. The tool integrates key design parameters, barrier geometry, CAC loading, groundwater velocity and influent concentrations to provide a systematic framework for preliminary longevity indication. The model can be used to provide longevity estimates to which safety factors can then be applied or can be used as baseline predictions to be compared to an observational approach to long-term management over decades of operation.
Highlights:
- There are only two proven remediation strategies for controlling PFAS in groundwater: (1) groundwater pump and treat systems which require additional ex-situ treatment and (2) construction of permeable sorption barriers (PSBs).
- Provides guidance for constructing colloidal activated carbon barriers to treat PFAS plumes
- Median longevity values for a single CAC application for 17 site designs modeled in this study are 870, 150 and 180 years for PFOS, PFOA, PFHxS.
- Barrier longevity may be extended further by combining CAC barrier injection with source stabilization
References
1. SERDP Project ER21-1130 and ESTCP Project ER24-8200
2. Newell, C.J., Smith, W.B., Kearney, K., Clay, S., Javed, H., Carey, G.R., Richardson, S.D. and Werth, C.J. (2025), Tool and Database for Estimating Potential
Longevity of Colloidal Activated Carbon Barriers for PFAS in Groundwater. Remediation Journal, 35: e70017. https://doi.org/10.1002/rem.70017
