While decommissioning a former power plant, a confidential client found water contaminated with per- and polyfluoroalkyl substances (PFAS) in the process of dewatering the facility’s basement. After discovering the PFAS, the client hired Barr to characterize impacts and develop a water treatment system.
We began by collecting samples to evaluate both potential sources of PFAS and treatment methods. During sampling, the water generated during the basement dewatering was also found to have a pH level higher than applicable discharge criteria, meaning that the pH would also need to be mitigated before discharge. Barr completed a feasibility-level assessment of treatment methods for PFAS and pH, recommending a system that used granular activated carbon (GAC) to remove PFAS and carbon dioxide aeration to mitigate pH. We worked with a remediation contractor to complete bench- and pilot-scale testing before providing a turnkey design of the treatment system. We also oversaw the operation of the treatment system, which included conducting routine sampling to assess the remaining absorptive capacity of media and adjust the system as needed.
Approximately 26.5 million gallons of PFAS-impacted and high-pH water were treated by the system. Throughout the duration of the project, monitoring results indicated that effluent water quality met the project objectives. Continual treatment of water generated from the dewatering activities allowed the decommissioning process to continue uninterrupted, and the project was successfully completed in 2020.