The method of application of limited inverse problems to determine admitted chemical concentration on the soil surface is elaborated. The process of transport of pollutants soluble in soil water is described by the hydrodynamic dispersion equation. The method lets for restoring the border condition on the soil surface. This is obtained on the bases of the concentration changes in the selected depths during the process. The example of method application is presented when the soil moisture and flow rate are spatial and time variable. The converges of the method has been investigated. ...