The field study sites cover a spectrum of major drinking water supply systems in Europe with special emphasis on high risk sites. 

The selection of the different study sites provide a cross-cut in terms of

i) treatment by the waterworks,

ii) climate zones, i.e., from humid Nordic sites to continental Eastern European sites and to arid Mediterranean sites, and

iii) size of the water supply zone, i.e., from large water works (>1 Mio. people supplied) down to private supply by rain fed cisterns.

For the detailed studies, specific emphasis will be put on high risk periods (e.g., heavy rain events) and high risk sites (polluted river water, river bank filtrate of polluted rivers). Sampling and sample analysis will comprise the water sources, the water ex waterworks, the mains and tap sampling.