Non-point pollution outflow is affected by stormwater and flows into various rivers and lakes. To prevent this phenomenon it is urgent to develop non-point pollution outflow filtering techniques. In order to determine the material of the filtering system, clay (good for adsorption) and sand (good permeability characteristics) were mixed and a constant head permeability test was performed on the specimen. To each mixing rate permeability is estimated and through the change of permeability, resistance and resistivity within the test results, monitoring the life-time and efficiency of the filter material is possible