The course provides information on basic properties of aqueous systems, chemical composition of waters in respect to the form of occurence and properties of individual components. Chemical reactions and equilibria in waters, inorganic compounds in waters (main cations and anions, toxic metals, compounds of nitrogen and phosphorus), carbonate chemistry of aqueous systems. The problems of influences of rock environment on hydrochemical composition of natural waters are solved (major and minor components). Composition, properties and classification of natural waters. Differences in chemical composition of the „clean" surface and ground waters. Organic compounds in waters (humic compounds, pesticides, hydrocarbons, halogenderivates, tensides). Composition, properties and classification of waste waters.