The huge amount of phenolic wastewater generated at coke oven plants is nowadays partially utilized during the wet coke quenching process. The stream, however, contains a range of inorganic compounds (i.e., chlorides, alkali and sulphates), the presence of which in the coke is highly undesired. Moreover, the impact on the quenching water composition on the final quality of coke, considering the concentrations of mineral contaminants, is unknown. Our paper investigates the composition of quenching water – in particular the impact of chlorides and sodium ion content on the final quality of wet-quenched coke. We used dry-quenched coke, treated rainfall, and treated phenolic wastewater generated at one the largest coke plants in Poland. Our study showed the existence of linear dependences between chlorides and sodium ion content in quenching water, and their fi nal amount in the wet-quenched coke. We developed the calculation procedure of the maximum share of the treated phenolic wastewater in the quenching water stream, at which the contract parameter of coke could be held, based on the basis of our experimental results.