### Model of transport of pollution without remediation pumping

The first picture shows the longitudinal section 1-1’ of the groundwater pollution state 1 year after building the sealing wall. According to this picture, pollution does not seep through the wall in 1 year’s time. The mass flow of the pollutant into groundwater was set in the model by giving the concentration 3 mg/l oil. The pollution flows orthogonally to the water surface and the value is the maximum concentration at the groundwater surface. The intensity of mass flow decreases with time. The regular decrease in the intensity of the flow set in the model corresponds to half of the flow after 5 years. This picture shows that the pollution is concentrated in that part of the sealing wall that intersects the groundwater flow. The second picture shows the same section 1-1’ as above, but after 5 years. In this time the pollution spreads behind the sealing wall. There is a concentration of 2.5 mg/l pollutant in groundwater behind the wall in the direction of the flow. The solution implies that the pollution remains in the area surrounded by the sealing wall only for 1 year or so. After 1 year, without remediation, the pollution leaves the area in the direction of groundwater flow. The remediation is therefore necessary.