Directives are the EU legal instrument to bring different national laws into line with each other, and are particularly common to set EU standards. EU directives lay down certain end results that must be achieved in every Member State. National authorities have to adapt their laws to meet these goals, but are free to decide how to do so.
The most important Directive in this topic is the 2000 Water Framework Directive (WFD) which aims to achieve good water status (a term that incorporates both chemical parameters (i.e. low pollution levels) as well as ecological ones (healthy ecosystems)) for all waters (inland, coastal and river) across the European Union by 2015. The Directive also aims to ensure clean waters are kept clean. Under the Directive, water management is based on River Basins. EU Member States set up river basin districts and designate the administrative unit for each district. Where a river basin includes more than one Member State or crosses from the EU to neighboring countries, the Directive calls for the creation of an international river basin district. Both national and international districts were supposed to prepare management plans by 2009.
Other relevant EU policies and laws are the following:
The Marine Strategy Framework Directive (MSFD) adopted in July 2008 aims at achieving or maintaining a good environmental status by 2020 at the latest.
The 2006 Bathing Water Quality Directive
Directive 98/83/EC on the quality of water intended for human consumption
Directive 2006/44/EC of the European Parliament and of the Council of 6 September 2006 on the quality of fresh waters needing protection or improvement in order to support fish life (codified version) and Directive 2006/113/EC of the European parliament and of the Council of 12 December 2006 on the quality required of shellfish waters (codified version)
Directive 91/271/EEC concerning urban waste-water treatment
Directive 91/676/EEC concerning the protection of waters against pollution caused by nitrates from agricultural sources
Directive 2006/118/EC on the protection of groundwater against pollution and deterioration
Directive 2009/90/EC laying down, technical specifications for chemical analysis and monitoring of water status 32009L0090
Directive 2012/75/EU on industrial emissions (integrated pollution prevention and control)