Evaluating Bank Filtration as an Alternative to the Current Water Supply from Deeper Aquifer: A Case Study from the Pannonian Basin, Serbia

Groundwater from a depth of 100–200 m is the main source of public water supply in most municipalities in the Pannonian basin in central and southeastern Europe. Even though its quality does not always meet EU standards for drinking water—including those regarding arsenic—in many villages and even in some major cities no treatment except chlorination takes place. Of the several alternatives to improve the water supply situation in the Autonomous Province of Vojvodina in the northern part of the Republic of Serbia, re-orientation towards more centralized systems combined with river bank filtration as an additional and sustainable raw water resource was evaluated as the best. A hydrogeological and hydrochemical survey of the Tisa (or Tisza) River alluvium in the Padej test field confirmed the aptness of this approach. A good connection between the Tisa River bed and the alluvial aquifer consisting of fine-grained sand was found (average hydraulic conductivity of 5 × 10⁻⁵ m/s). With appropriately designed and managed wells, 80–100 l/s bank filtrate per km of river bank can be produced for water supply. Comprehensive analysis of the river water and river bank filtrate as well as a pilot treatment of the bank filtrate suggest that aeration-oxidation-flocculation-filtration-disinfection is a suitable technology for the Tisa River bank filtrate.