The objective of the Council Directive 91/271/EEC or Directive concerning urban wastewater treatment (also known as the Urban Waste Water Treatment Directive or UWWTD) is to protect the environment from the adverse effects of discharges of both urban wastewater from settlement areas and biodegradable industrial wastewater from food industries. The UWWTD requires that all European settlement areas or agglomerations with a size of 2,000 population equivalents (p.e.) or above be equipped with collection and treatment systems for their wastewater. The UWWTD establishes detailed criteria for collection and the required levels of treatment, which depend on the size of the agglomeration, and the type of receiving water in which the treated wastewater is discharged. To assess the level of implementation of the UWWTD, the Commission requests all EU Member States to report detailed information every 2 years at agglomeration and treatment plant levels, according to Article 15 of the UWWTD, as well as information on their implementation programmes, as required by Article 17 of the UWWTD. The data treatment and assessment rules are spelled out in a detailed methodology. The calculations are implemented in the EEA system and results are used for the assessment. There are many different and specific situations, but – in short – an agglomeration is considered compliant with the UWWTD only if it fully collects its wastewater and treats it appropriately. Treatment must reduce the organic pollution in all cases. For agglomerations above 10,000 p.e. and discharging into sensitive areas, the treatment applied must also reduce at least the nutrients (nitrogen and/or phosphorus). This 12th UWWTD implementation report uses the reported data to present the situation in the EU and in its 27 Member States for the year 2020.
