Assessment and management of tap water lead contamination in Lower Saxony, Germany

Lead is known to have numerous adverse effects especially to infants and children. The intake of lead through drinking water is commonly due to metal corrosion in the peripheral water distribution system, especially the user's plumbing. The aim of this project was to assess the present state of drinking water contamination with lead in Lower Saxony and to promote replacement of lead pipes. For this purpose a project was initiated comprising three parts. First, a free examination of drinking water was offered in cooperation with local public health departments for private households with young women and families with children living in buildings constructed before 1974. Participants were asked to collect a cold tap water sample in their household after nocturnal stagnation and to complete a questionnaire. The collected samples were analysed by atomic absorption spectrometry for their lead concentration. Second, data from local public health departments on results of lead measurements, especially in buildings for the public, were collected and analysed. Finally a working group 'lead replacement' was initiated. In the project in total 2436 tap water samples from households were collected. Of these, 6.49% had lead concentrations exceeding 10 mu g/l (recommended limit of the World Health Organization) and 2.79% had concentrations above the limit of the German drinking water ordinance (25 mu g/1). There were remarkable regional differences in the frequency of tap water contamination. Multi-family houses were more frequently affected than single- and double-family houses.