The occurrence of microorganic contaminants (pharmaceuticals and pesticides) in a river bank filtration site recharged by an agriculturally- and wastewater-impacted small lowland river (Oborniki site, Poland)

A high contamination level by microorganic pollutants (contaminants of emerging concern - CECs and pesticides) was documented at the Oborniki river bank filtration site (Poland) recharged by surface water from the Wełna River. The highest concentration of CECs and pesticides was found in surface water samples. The documented contamination level of Wełna River water (the river draining a small lowland catchment) is higher than that documented in bigger rivers like the Warta, Izera and Elbe. High contamination levels were documented also in wells that are recharged by water from the Wełna River via bank filtration. The removal rate observed in wells (compared with source river water) was estimated as 57% for CECs and 74% for pesticides while the removal rate calculated for carbamazepine (a conservative pharmaceutical substance) was 26%. In one well the nicosulfuron concentration was higher than the upper permissible limit. Among the substances detected were also 2 banned constituents: chlorotoluron and izoproturon.