Solute transport monitoring in the Ljubljana urban aquifer

Groundwater from a Pleistocene sandy-gravel aquifer is an invaluable drinking water resource for the Ljubljana city (Slovenia), as well as for the Union brewery, which is located within an industrialized area near the centre of Ljubljana. A big part of the aquifer recharge area is highly urbanized, which represents a great risk for the groundwater quality assurance. The extensive monitoring of solute transport was performed in the brewery catchment area with the intention to analyze the contamination risk of drinking-water resources. It based on continuous measurements of hydrodynamic parameters and of physico-chemical water parameters (T, SEC) and on groundwater sampling for herbicide, isotope, trace elements and trace gas analyses. results indicated possible contaminant inflow into the Union brewery area. The results pointed out the risk of pollution breakthrough into the lower gravel aquifer and served for the development of a local hydraulic model