Water supply and sanitation (WSS) in the European Union (EU) is the responsibility of each member state, but in the 21st century union-wide policies have come into effect. Water resources are limited and supply and sanitation systems are under pressure from urbanisation and climate change. Indeed, the stakes are high as the European Environmental Agency found that one European out of ten already suffers a situation of water scarcity and the IEA measured the energy consumption of the water sector to be equivalent to 3,5% of the electricity consumption of the EU.