Wastewater treatment infrastructure in the European Union and micropollutant removal under the recast Urban Wastewater Treatment Directive

The recast Urban Wastewater Treatment Directive (Directive (EU) 2024/3019) introduces micropollutant-removal requirements alongside stricter nutrient standards. This study assesses EU wastewater infrastructure readiness, reviews regulatory obligations and options for quaternary treatment, and identifies technological and strategic gaps. Data for 22,024 urban wastewater treatment plants (UWWTPs) from the European Environment Agency Waterbase dataset were evaluated using descriptive statistics and hierarchical clustering at Member State level. Regulatory provisions and treatment options were reviewed in relation to infrastructure patterns. Small UWWTPs (