During the pumping of wells, the groundwater level drawdown, as measured in the pumped well, is increased by non-linear losses caused by the water flow velocity through the well screens. This undermines the adequacy of the direct use of the measured drawdown data in the well for the purpose of the realistic identification of the effective well radius and aquifer parameters. This anomaly is avoided by reshaping the drawdown function into a function of the specific drawdown $s_w/Q$ of the pumped well. This reshaping simplifies the exclusion of non-linear losses from the sequence of measured data of the water level in the well at the position of the effective radius of the pumped well. Combining the data of linear losses and the respective pumping rate of the pumped well, a function of the specific drawdown of the radial flow $s_w/Q$ was formed. This function describes the aquifer parameter relations during the respective test pumping. A consistent sequence of the function of the specific drawdown $s_w/Q$ of the pumped well reveals the actual value of the coefficient of nonlinear losses. Moreover, the specific drawdown function enables the reliable estimation of aquifer transmissivity using only the pumped well drawdown data.

Soil plays an important role in the accumulation and transport of potentially toxic elements (PTEs), from surface into aquifer. PTEs can get to the environment naturally, but also from different kinds of contamination sources. In this study, a soil profile located in the vicinity of well field Petruševec, one of the most important well fields related to the public water supply of the City of Zagreb, was analyzed. The main aim of this study was to determine soil properties which can influence retention/mobilization of Ni and Cr in alluvial soil, as well as to define their origin in the investigated soil profile. Results suggest that Cr is geogenic, while Ni is probably of dominantly anthropogenic origin. Observed concentrations, enrichment factors and I_geo values showed no enrichment for Cr, while for Ni, they showed minor to very severe enrichment, i.e., that in some soil horizons, moderate to strong pollution exists. Evaluation of wind directions and location of possible contamination sources that prevail in the study area suggest that Ni can come by aerodeposition from different sources. Results showed that mineral composition can have important influence on retention of analyzed PTEs. Soil horizons, which have very high concentrations of Ni, in general have higher proportion of clay minerals, especially chlorites, as well as Fe oxyhydroxides which can act as an adsorption phase for the investigated PTEs. Results suggest that more detailed research about the investigated PTEs presents a necessity if measures for soil and groundwater protection want to be effectively implemented.