This publication addresses the problem of arsenic purification in drinking water. The damage that arsenic causes to the human body and what its maximum permissible concentration in water can be are described. A brief overview of methods for purifying drinking water from arsenic is presented. The advantages and disadvantages of different technological solutions are shown.As a result of the analysis, an option of a combined local system for joint purification of drinking water from iron and arsenic is proposed. A technological scheme of the drinking water treatment plant is presented, the main ratios for determining the volume of water for the individual washes are derived, and an algorithm for managing the washes of the first stage of the installation is developed in order to avoid exceeding the waste water limits and to increase the life of the filter media. In conclusion, a prescription is made of which technical means the combined system can be implemented.