Water pollution poses a danger to human health and, as a result, there is a need to identify ways to clean it. In this study, a quantitative chemical analysis of water taken from the well and after its passage through membrane purifi cation (reverse osmosis method) was carried out in the period from 2019 to 2023. The research area is Moscow, Moskovsky settlement. The following physico-chemical characteristics were determined: odor, color, turbidity, pH, total hardness, permanganate oxidizability, mass concentration of ammonium ions, total iron (Fe2+ and Fe3+), nitrates, nitrites, manganese, fl uorides, chlorides, dry residue, sulfates, anionic surfactants, petroleum products. The results obtained have shown the eff ectiveness of the use of membrane water purifi cation. The color has decreased. The turbidity, which exceeded the normative indicators (7.7), became within the normal range – 2.1. The values of the dry residue and premanganate oxidizability did not change signifi cantly, their values were within acceptable values in the initial water samples. The high iron content exceeding the MPC decreased to acceptable values (from 0.882 to 0.188 mg/dm3 on average during the study period at a MPC of 0.3 mg/dm3 ). The method allows to reduce the increased content of manganese (from 0.19 to 0.03 mg/dm3 at MPC 0.1 mg/dm3 ) and petroleum products (from 0.16 to 0.06 mg/dm3 at MPC 0.1 mg/dm3 ), as well as ions NH4+, NO3-, NO2-, F- , Cl- , SO4 2- and surfactants.