PFAS Wastewater Treatment Strategies for WWTPs
Developing Data-Driven Strategies to Mitigate PFAS in Wastewater Treatment Plants
Wastewater treatment plants (WWTPs) play a central role in the environmental cycling of PFAS, acting as both receivers and redistributors of these persistent compounds. Despite significant technological advancements over the years, conventional treatment systems remain largely ineffective in removing PFAS, resulting in continued discharge into surface waters and accumulation in biosolids.
Understanding how PFAS behave throughout the treatment process can help utilities and remediation teams identify potential sources, evaluate treatment technologies, and develop practical PFAS management strategies.
Key Takeaways
— Conventional industrial wastewater treatment systems have limited ability to remove or destroy PFAS, and precursor compounds may transform into measurable PFAS.
— PFAS can move among treated effluent, sludge, biosolids, and other residual streams, making it important to evaluate their behavior across the entire treatment system.
— Effective PFAS management may require a combination of upstream source control, targeted treatment, and planning for PFAS-containing residuals.
— Treatment performance varies based on PFAS composition, water chemistry, flow, and facility-specific objectives.
— Bench-scale and pilot testing can help utilities compare treatment options, understand requirements, and reduce uncertainty before implementation.
How PFAS Behave During Wastewater Treatment
PFAS are uniquely resistant to many biological and physical processes commonly used in wastewater treatment. To better understand their behavior, a comprehensive meta-analysis was conducted using data from over 1,500 WWTPs across more than 100 peer-reviewed studies worldwide. The analysis was synthesized into a global interactive map illustrating PFAS concentrations in influent, effluent, and residual treatment streams.1
The findings confirm that PFAS persist globally across all stages of wastewater treatment. Conventional systems that rely on biological degradation, sedimentation, or filtration show limited removal of well-known, commonly regulated compounds. More often, conventional wastewater treatments increase the concentration of perfluoroalkyl acids, including PFOA and PFOS, due to the transformation of precursor compounds.
Limitations of Conventional and Advanced Treatment for PFAS
Even WWTPs equipped with tertiary treatment processes, such as advanced filtration or oxidation, demonstrated limited PFAS removal. While PFAS can be treated with widely used adsorptive media (e.g., granular activated carbon or ion-exchange resins), these media are not typically used at WWTPs.
Across the treatment configurations evaluated, the resulting median effluent concentrations for several PFAS compounds often exceeded 10 nanograms per liter, reinforcing the limitations of even advanced treatment configurations. These findings underscore a critical reality: no single treatment solution is universally effective for managing PFAS.
Instead, effective strategies must be tailored to site-specific influent characteristics, treatment configurations, and end-use objectives. Many technologies separate or concentrate PFAS rather than destroy them, so evaluations should also consider how these residuals will be managed.
PFAS Wastewater Management Strategies for WWTPs
While drinking water systems have made measurable progress in PFAS treatment, WWTPs remain a substantial source of environmental PFAS release. Understanding PFAS behavior through each treatment stage enables project teams to anticipate where removal challenges will arise and to design targeted, cost-effective interventions.
As regulatory frameworks evolve, including USEPA’s draft human health risk assessment for PFOS and PFOA in biosolids and its 2026 draft guidance for reducing risks from PFOA and PFOS in biosolids, facilities must adopt integrated strategies such as source control, pre-treatment, and residuals management. Practical strategies may include isolating PFAS-rich industrial inputs, implementing advanced separation processes, or stabilizing biosolids through chemical methods or thermal treatment to destroy PFAS and limit downstream impacts.
Source Control and Pretreatment
Identifying and controlling PFAS before they enter a WTTP can help utilities focus resources on the most significant sources. Potential inputs include industrial discharges, landfill leachate, septage, or hauled waste. Targeted monitoring can help identify concentrated sources and determine where pretreatment or discharge control may be needed.
Treatment Technology Evaluation
Utilities also may evaluate treatment technologies within the plant. Granular activated carbon, ion-exchange resin, and high-pressure membrane systems such as nanofiltration and reverse osmosis can help remove PFAS from water. Performance can vary based on PFAS chain length, water chemistry, flow rate, and treatment objectives. Short-chain PFAS are mobile and can be more difficult to capture than longer-chain compounds. A site-specific evaluation is necessary to compare treatment effectiveness and practicality.
Residuals and Biosolids Management
PFAS removed from the liquid stream do not disappear, and they may become concentrated in spent media, membrane concentrate, sludge, biosolids, or other residuals that require further management. Available approaches may include:
— Stabilization
— Controlled disposal
— Evaluation of emerging destruction technologies such as pyrolysis, supercritical water oxidation, and other thermal or chemical processes
Treatment planning should evaluate how these materials will be characterized, handled, treated, and disposed of while considering regulatory disruptions and potential downstream impacts.
What is the Path Forward for PFAS Management in WWTPs?
Selecting an appropriate PFAS management strategy requires site-specific data and an understanding of treatment performance and operational requirements. Bench-scale and pilot testing can play a vital role in helping utilities select and optimize these strategies for WWTPs and other remediation systems.
At Langan’s Treatability Facility at the New Jersey Institute of Technology, the team supports clients by testing advanced and innovative treatment methods to evaluate PFAS removal efficiency and develop full-scale implementation strategies. These targeted studies help reduce uncertainty, minimize risk, and identify sustainable, regulatory-compliant solutions.
Langan’s PFAS experts work with clients to translate research into practical remediation strategies—bridging the gap between bench-scale results and field-scale success. By combining robust data analysis, targeted testing, and integrated planning, project teams can achieve efficient, science-based management of PFAS in wastewater and biosolids systems.
Ready to evaluate your PFAS treatment options for WWTPs? Contact Langan’s PFAS experts to learn more.
Amita Oka, PhD, is an environmental scientist with over 15 years of experience, specializing in remedial technology evaluation, engineering design, and full-scale implementation of physical, chemical, and bioremediation alternatives. Her work also focuses on in-situ treatment, treatability testing, and pilot testing of PFAS-impacted media. Located in Langan’s Princeton office, Dr. Oka is actively involved in the Langan Treatability Facility at New Jersey Institute of Technology.
Charbel Abou-khalil, PhD, is an environmental engineer in Langan’s Princeton office, specializing in PFAS remediation, wastewater treatment, and site characterization. His 10 years of experience include contaminated site investigation and remediation, soil and groundwater sampling, vapor intrusion investigation, and remedial investigation, design, implementation, and monitoring.
1 Central to the work performed by Dr. Charbel Abou-khalil at the University of Notre Dame (Doudrick Lab) and a continued resource in his work as a practitioner.
PFAS Wastewater Treatment FAQs
Where does PFAS in wastewater come from?
PFAS can enter wastewater treatment plants through industrial discharges, landfill leachate, septage, and hauled waste. Identifying concentrated sources may allow a facility to reduce PFAS before they reach the main treatment process.
Can conventional wastewater treatment remove PFAS?
Conventional biological treatment, sedimentation, and filtration generally do not destroy PFAS. Some PFAS may pass through the treatment system, divide into sludge or biosolids, or form through the transformation of precursor compounds.
Which technologies remove PFAS from wastewater?
Potential technologies include granular activated carbon, ion-exchange resin, membrane separation, and other emerging separation or destruction processes. Performance depends on factors such as PFAS composition, water chemistry, flow rate, treatment objectives, and residual-management requirements.
How are PFAS managed in sludge and biosolids?
Facilities can begin by characterizing PFAS concentrations and sources, evaluating how PFAS move through the treatment system, and reviewing available residual-management options. Choosing the right approach depends on site conditions, intended biosolids use or disposal, and regulatory requirements.
Why is treatability or pilot testing important?
Treatability testing evaluates technologies using site water and operating conditions. It can reveal the effects of water chemistry, competing contaminants, PFAS composition, media consumption, and residual generation. Pilot testing can then assess performance and operational requirements before a full-scale implementation.