The European Commission has urged Spain to comply with the requirements of the Council Directive 91/271/EEC on the treatment of urban wastewater.
EU Member States must provide secondary treatment of all discharges from agglomerations larger than 2,000-population equivalent, and more advanced treatment for agglomerations larger than 10,000-population equivalent in designated sensitive areas.
Secondary treatment supplements the elimination of solid matter from urban wastewater (called primary treatment) with the breaking down of the organic substances by using bacteria. Sometimes, further treatment (tertiary) is required to protect sensitive water environments. Tertiary treatment can involve disinfecting the treated effluent to protect bathing or shellfish waters. It can also involve the removal of phosphorus or nitrates (nutrients present in sewage) to protect waters that are threatened by eutrophication.
The Commission's enquiries revealed a widespread failure to comply with the Directive's obligation in mostly large agglomerations in Spain and a letter of formal notice was sent in December 2016. A technical assessment of Spain's replies shows that non-compliance with the obligations of the Directive is still at a large scale, considering that 133 agglomerations discharge either in normal or sensitive areas. Despite some progress, full compliance is not expected in the near future.
The Commission has asked Spain to accelerate compliance. Spain has two months to reply. If Spain does not act within the next two months, the Commission may refer the case to the Court of Justice of the European Union.