The presence of lead in drinking water poses a range of risks to human health, including the retardation of some aspects of child development, the inducement of abortion, and other clinical disorders. The extent of these risks has not been quantified at the European Union (EU) scale. A number of sampling methods are in use across the EU, some of which are inadequate for determining the concentrations of lead in drinking water at consumers' taps. In consequence, non-compliance with the EU standards for lead in drinking water has been under-estimated. Emerging data indicates significant non-compliance with these standards in some countries, particularly with the 10 μg l−1 standard that will become a legal requirement in 2013; the current interim standard of 25 μg l−1 is also exceeded in some locations. An initial estimate is that 25% of domestic dwellings in the EU have a lead pipe, either as a connection to the water main, or as part of the internal plumbing, or both, potentially putting 120 million people at risk from lead in drinking water within the EU. These issues are relevant to the implementation of the Protocol on Water and Health and to drinking water safety planning.