The Influence of Anthropogenic Contamination on the Groundwater Chemistry of a Semi-confined Aquifer (The Wielkopolska Buried Valley Aquifer, Poland)

The problem of the identification of the influence of anthropogenic contamination on the groundwater chemistry of a semi-confined buried valley aquifer is presented. It has been shown that the symptoms of groundwater chemistry transformation due to anthropogenic contamination appear, even though confined conditions occur. Statistical techniques have been used for the identification of this problem. Factor analysis has been used to recognize the most vulnerable parts of the aquifer. Based on the factor scores, data sets characterizing natural and pollutant groundwater chemistry were distinguished. The comparison of the “natural” groundwater chemistry with the whole data set (by means of the correlation analysis and regression analysis) enabled the identification of the components which are the most sensitive to anthropogenic impact. The changes of groundwater chemistry over time identify the intensity of the anthropogenic impact.