In any case, the study recommends controlling the extraction of water for bottling plants, as well as over-exploiting cold groundwater close to hot water springs. This way the mixing of waters is avoided and so are the pollutants.
For the same reason it is not advisable to build wells close to geothermal upwellings, especially illegal ones for private supplies or irrigation. Studying geothermal liquid outlets in areas of diffused discharge, such as some humid areas, is also proposed.
The problem of uranium in waters
"Making a model for managing the whole aquifer to rationalize water extraction and consumption would be the solution" Navarro says. He also highlights the need to take action regarding the natural water pollutants: uranium.
The analysis in La Selva shows "relatively high" levels (37.7 microg/l) of this element, especially in samples from sources and wells not directly linked to thermal activity.
The mobility of uranium is linked to granite rocks and is frequently found in Catalan coastal mountain ranges, where researchers have carried out specific studies on the topic. The samples have been taken from wells and drilling at a depth of up to 100 metres.
The results published in the journal Tecnologa del agua and they show "significant concentrations" of uranium in groundwater used for public supply and bottling. Specifically, in some parts of the Montseny-Guilleries mountain range, these levels are more than 140 microg/l.
There are no legal limits for uranium concentrations in water in the European Union, but the analysis carried out in Catalan coastal mountain ranges shows that these levels far exceed the recommendations of the World Health Organisation (WHO)
FECYT - Spanish Foundation for Science and Technology