Abstract. The main purpose of freshwater ecosystems is to provide drinking needs meeting the water quality requirements for health. Pure raw water is needed not only for drinking, but also for many technological purposes. Good raw water causes the reduce of water treatment costs. Therefore, the quality of water in natural sources is an important factor not only for drinking water supply or for achieving higher economic impact of production, but it also contributes to the development of biodiversity, which is beneficial for the environment and society. Water supply of Lviv is provided exclusively from underground sources located at a distance of 20 to 80 km, so it is of high quality everywhere, but differs in chemical composition, and properties. However, it is widely believed that water from natural sources is better than tap water. In the territory of Lviv, Bryukhovychi and Vinnyky there are more than ten such springs, water from which is used by the inhabitants of the city and villages. The aim of the work is to determine whether the water from springs located in the city is suitable for drinking needs. As a result of the conducted research, it was found that water from springs located in Lviv is not suitable for drinking. According to the research results, in all spring water samples the content of calcium and magnesium is significantly higher than in the sample taken from the city water supply network. The total water hardness in all sources exceeds MPC. The content of sulfates, chlorides, nitrates, nitrites and ammonium ions in all spring water samples is much higher than in tap water. The content of total ammonium ion in water from source # 3 almost reaches the limit of MPC (0.95MPC). Lead content in all samples taken from springs exceeds the MPC.
Static and dynamic approach to estimation of spring water hardness cation content as a natural factor of groundwater formation
