Abstract: Leachate of contaminated water from sulfide mine residual products is a great environmental problem in Sweden.This paper summarizes an investigation carried out in order to minimize the leachate production from the residual products by means of covering the deposits with natural soil materials.The study shows that natural soil types have such a high infiltration capacity, that no significant sealing effects are obtained.It is only possible to reduce the infiltration at periods with intense precipitation or rapid melting of snow, and then only the peaks in the leachate production are affected.Nevertheless, the sealing and covering layer on the top of a deposit are of great importance as water reservoirs and thus increasing the evapotranspiration losses.