Water for Warsaw and neighbouring cities of the Warsaw Province is abstracted from two sources: the Vistula River and Zegrzyński Reservoir. The Vistula water is below any classification of water purity due to its physical and chemical properties, and water quality of water in the Zegrzyński Reservoir is better as regards chemical composition and microbiological characteristics. It does not meet, however, the requirements for class I water purity. In recent years, there has been an improvement in water quality supplied for Warsaw.