EPA Research Partner Support Story: Evaluating granular activated carbon technologies for removing PFAS from drinking water

Partner: Georgia Department of Natural Resources
Challenge: Understand effectiveness of granular activated carbon (GAC) for removing PFAS from a community drinking water system
Resource: Modeling and evaluating various design/operation configurations and lead/lag operations evaluations for GAC removal of PFAS
Project Period: 2020

The Georgia Department of Natural Resources and EPA Region 4 (Southeast) contacted EPA ORD seeking assistance on behalf of a Georgia community assessing the effectiveness of using granular activated carbon (GAC) for removing per- and polyfluoroalkyl substances (PFAS) from their drinking water. The community had sand filters that had been in service for years, and they were interested in replacing some or all of the sand with GAC to address PFAS removal.

“Georgia shout out to [EPA ORD] ‒ the modeling analysis was very useful in helping Summerville develop their path forward!" – Georgia DNR Watershed Compliance Program Manager Lewis Hays

In February 2020, ORD researchers modeled different local conditions to inform the choices the community was exploring. During these initial discussions, the objective was to understand how effective adding GAC to the current drinking water system would be for maintaining safe PFAS levels (EPA health advisory of PFOS + PFOA below 70 ng/ L) under the system’s current production rates. This would then inform them as to whether they ultimately had to build a more robust system specifically set up for PFAS removal.

ORD provided actionable model results and consulted with their project partners from EPA Region 4 and the state on other technologies the utility could consider. The results of the modeling showed that GAC would likely provide PFAS removal at current treatment rates and provided some initial estimates for bed replacement intervals. This work highlighted that replacement of carbon in the current system could act as a stopgap measure to provide immediate treatment of PFAS to below the health advisory level, and it warranted an additional evaluation. Based on this work, the utility set up a confirmatory GAC test for evaluation.