PFAS Removal via Granular Activated Carbon — Dutch Municipal WTP

## Background Hilversum's drinking water treatment plant draws from a riverbank-filtration source impacted by legacy industrial PFAS discharge. Following the EU DWD 2020/2184 target sum of 0.1 µg/L for 20 PFAS, the operator required a retrofit solution. ## Challenge Achieving ≤ 0.1 µg/L sum-PFAS in finished water at 45,000 m³/day without full plant rebuild; managing GAC exhaustion and spent-carbon disposal under Dutch hazardous-waste rules. ## Approach Existing rapid sand filters were converted to dual-media GAC filters (900 mm coal-based GAC over 300 mm support gravel). Empty bed contact time was set at 11 minutes. A reactivation contract with the GAC supplier provides carbon exchange every 18 months, with reactivated carbon returned to service. ## Results - Sum-PFAS in finished water: 0.018 µg/L (82 % below limit) - PFOA + PFOS: non-detect (< 0.002 µg/L) - Capital cost: €3.8 M (vs. €22 M for a new nanofiltration train) - Carbon exchange cycle validated at 18 months EBCT