Changes of chloride concentration in the Vistula river in Kraków

The paper presents the study of chloride concentrations in the Vistula river in Krakow, performed from 1990'. Growth of black coal mining in the Upper Silesia and the D¹browa Basin had significant impact for water quality in the Vistula river. After Second World War, year by year, the chloride concentration was being raised, in the end of 1970' reached 30g/l. Saline mine water discharge led to change hydrochemical water type from Ca–HCO3 to Na–Cl. Due to Polish Environment Law, concentrations of that ion was reduced, mostly to value below 1g/dm3. The water of the Vistula river has been sampled almost every week. The studies showed variability of chloride concentrations. Rate of water salinity depend on amount of the mine water discharge and water flow in the Vistula river. No cooperation between particular mines contributed to stochastic, variable salinity level