Determination of the interval of salinization at the walls of drains (wells, galleries, mine workings, etc.) is of great practical and theoretical importance. In recent years, it has been given special attention in our country and abroad, but so far there are no practically acceptable solutions. The approach to solving this issue is still determined by how researchers understand the theory of Dupuy and his famous formulas and how they represent from the physical side the process of formation of the salinization interval.