Geochemical and Sanitary–Chemical Characteristics of Water Springs of Bogorodsky and Losino-Petrovsky Districts of Moscow Oblast

The article focuses on the results of water parameters (COD, pH, electrical conductivity) and the contents of major ions (Ca²⁺, Mg²⁺, Na⁺, K⁺, \({\text{NH}}_{4}^{ + }\) , \({\text{HCO}}_{3}^{ - }\) , Cl^–, \({\text{SO}}_{4}^{{2 - }}\) , \({\text{NO}}_{3}^{ - }\) ) and trace elements (Co, Ni, Cu, Zn, Cd, Pb, Sr, Ba, Mn) for 12 springs in the Bogorodsky and Losino-Petrovsky districts of Moscow oblast. The waters are slightly acidic to near-neutral (pH 5.5–7.5) with the mineralization ranging from 0.07 to 0.5 g/L, the total hardness is 0.63–5.7 mg-eq/L, the water composition is variable. Spring waters are divided into four groups: Cl–SO₄–HCO₃–(Mg)–Ca, (SO₄)–HCO₃–Cl–Na–Ca; (Cl)–HCO₃–Ca, and mixed. Based on the thermodynamic calculation using the Visual-MINTEQ program, it was found that the predominant dissolved species of Ba, Sr, Mn, Zn, Cd, Ni, and Co in the waters of the surveyed springs are free ions. For Cu and Pb, the factors for the formation of migration species are the predominant anions of water, as well as the presence of organic matter in water. The COD values and nitrogen compound in the waters of individual springs indicate that the formation of the spring water composition is resulted from the infiltration of atmospheric precipitation through the modern sediments subject to anthropogenic loading. The values of other sanitary–chemical indicators (mineralization, pH, total hardness, chlorides, sulfates, magnesium, sodium, manganese), the content of regulated trace elements are lower than their maximum permissible concentrations in drinking water.