The EC Drinking Water Directive currently under developmend will follow the World Health Organisation recommendation to adopt 10 ug/L of Pb as the parametric value for lead in drinking water. At the moment the parametric value for this element is 50 ug/L. Lead in drinking water originates mainly from service pipes and internal plumbing. The actual exposure of consumers to lead depends strongly on the plumbing materials used, water composition (e.g. pH, alkalinity) and on the contact (or stagnation) time of the water and the plumbing system. The last varies according to consumer's behaviour (water use pattern). Therefore, the new EC DWP states that statutory monitoring of lead should take place at the consumer's tap and should be based on a sample 'representative of that consumed by man'.
The overall objective of this project is to develop and validate a monitoring protocol for lead in drinking water which meets the demands of being:
1. representative of that consumed by man;
3. practical; and
4. cost effective.
Three possibly successful sampling procedures have been selected. These sampling procedures are being tested throughout Europe. The results show correlations with the reference method. All laboratories involved in the test showed sufficient analytical capability.
The monitoring protocol consists of sampling at the consumer's tap and pre-treatment and analysis at a laboratory. To address these different aspects the work programme is divided into four work packages:
1. design of a new sampling procedure: based on theories on lead release to drinking water, statistical assessment of water use at the tap and experience with sampling procedure currently in practice, a new procedure will be developed;
2. assessment of analytical capabilities: the analytical accuracy for the determination of lead in drinking water down to the level of the new parametric value by laboratories involved in drinking water quality monitoring will be assessed on the basis of an interlaboratory study;
3. validation of the new protocol: through field tests in 375 properties in six countries, the new protocol will be validated. The composite flow proportional sample will be used as reference method;
4. introduction of the new protocol.
Funding SchemeCSC - Cost-sharing contracts
92982 Paris La Défense
78230 Le Pecq
SL7 2HD Marlow - Medmenham