The studies on boron concentrations were carried out on samples collected from the groundwater intakes located in Northern Poland: in the Lower Vistula Valley and in the Starogard Lake District, within diversified hydro-geological conditions and depths. In total, 57 samples of water for assays were collected from the following intakes: Tczew Park and Tczew Motława, Gniew, Wielkie Walichnowy, Małe Walichnowy and Pelplin. The deepest drillings extended to 180 m (cretaceous stages), out of which 20 % comprised quaternary formations up to 123 m deep. The analysis of water samples in these regions was performed from 2009-2011. The geological architecture of these areas was identified based on the legal documentation on water utilization submitted by the operators of the water intakes. The Polish sanitary regulations set the maximum content of boron in drinking water at 1.0 mg∙dm-3. In this context,  the waters from the mesoregion called Starogard Lake District can be assumed to have a good chemical status, the boron concentration did not exceed this threshold value in any of the 24 water samples tested. In the Lower Vistula Valley mesoregion, 17 out of 33 tested samples contained more than 1.0 mg∙dm-3 of boron, which means that prior to drinking these waters require treatment to reduce the concentration of boron to the permissible limit. Slightly higher concentrations of boron (on average 1.63 mg∙dm-3) were detected in water deposited in the cretaceous formations situated in Wielkie Wachlinowy and Małe Wachlinowy. It was also found that the content of boron in groundwater depended on the nature of geological layers from which the tested water samples were collected. The statistical analysis demonstrates that the aquifer stages had a significant impact on the content of boron in the tested water samples and the differences between them are significant.

19.3.2014