Geochemical atlas of European groundwater : bottled water

Analysis of natural bottled mineral water (usually derived from untreated ground water) can provide a first impression of ground water chemistry at the European scale. For this study, 1785 bottled water samples were purchased from supermarkets, representing 1247 wells/springs/boreholes at 884 locations. These were analysed for 72 parameters by a variety of methods. A very strict quality control programme was followed to ensure results of high standard that are presented as a geochemical atlas. These give a first impression of European ground water geochemistry. Many processes are seen to affect the hydrogeochemical fingerprint of ground water, including rainfall chemistry, climate, vegetation and soil zone processes, mineral-water interactions, ground water residence time and the mineralogy and chemistry of the aquifer (and contamination). It appears that geology is the major factor controlling the content and distribution for the majority of elements in bottled water samples. However, knowledge of geology alone is inadequate to predict the hydrogeochemistry of bottled water. A key observation is that natural variation is enormous, usually three to four and for some elements up to seven orders of magnitude. It has also been found that bottle materials can have an influence on bottled water chemistry. For example, leaching of Sb from the bottle material is so serious that the results cannot be used as an indication of natural concentration in ground water. Very few analysed samples (in general <1%) returned values exceeding maximum admissible concentrations for “mineral water”, as defined by the European Commission.