UWWTD

The Urban Wastewater Treatment Directive (UWWTD), officially Council Directive 91/271/EEC, is a significant piece of European Union legislation aimed at protecting the environment from the adverse effects of urban wastewater. Adopted in 1991, its primary objective is to ensure that wastewater from urban areas is collected and treated appropriately before being discharged into the environment. The directive sets out minimum standards for wastewater collection and treatment across the EU.

It classifies discharges into different categories based on population equivalents, requiring progressively more stringent treatment for larger agglomerations. Primary treatment, secondary treatment (biological treatment), and in certain sensitive areas, tertiary treatment (advanced treatment) are mandated. The directive also addresses the treatment of industrial discharges into urban wastewater systems and the disposal of sewage sludge, promoting its reuse where environmentally sound. Member states are responsible for transposing the directive into their national laws and ensuring compliance through monitoring and enforcement. The UWWTD has led to substantial improvements in water quality across Europe, reducing pollution of rivers, lakes, and coastal waters.