No adequate reaction has been observed of the decreased contaminant loads discharged by Łódź, particularly the loads of phosphorus, on its concentration in the Ner River. That’s why the im-pact of sediment on phosphorus content in the water was evaluated. Not only was the amount of phosphorus taken under consideration but also the equilibrium phosphate concentration (EPCo). The meaning of EPCo is that any phosphate concentration in the water below this value will lead to phos-phorus release from sediments. Performed study shows that in the Puczniew cross-section EPCo is higher then phosphorus concentration in water, thus with mean concentration of PO4 equal to 9.5 mg PO4·dm–3 phosphorus could be released from sediments. This concentration in Lutomiersk cross-section, however, equals 1.2 mg PO4·dm–3.