The surface waters in Russia’s Murmansk Region used for public water supply are exposed to the negative impact of dust particles carried from the storage facilities for mining waste. For example, lanthanides and other rare metals enter the surface waters in Lovozero District from the tailings storage facilities (TSFs) of the Lovozero Concentrator, which requires thorough water treatment of drinking water. Using the monitoring data of the natural water of the Virma River and of the tap water in the residential community of Lovozero, Murmansk Region, and with the help of physical and chemical modeling (in the software suite Selector), we examined the effect of reagents used in water treatment on water chemistry. It was shown that the use of aluminum polyoxydichloride coagulant can lead to an increase in the concentration of aluminum and chlorine in water, a change in pH and Eh values. The use of liquid chlorine leads to a decrease in pH values and a change in the concentration