PROBLEM TO BE SOLVED: To provide a system capable of purifying the soil in an area directly under a building structure.SOLUTION: Injection means 2,... are arranged in parallel along one side of the purification area A1 directly under a building structure D. Lifting pipes 3,... are arranged in parallel along the other side of the area A1. A clarifier is injected from the injection means 2,..., while underground water is pumped up through the lifting pipes 3,.... An underground stream is thereby generated over the area from the injection means 2,... toward the lifting pipes 3,..., so that the clarifier penetrates and spreads into the purification area A1 together with the underground stream. As a result, the soil in the area A1 can be purified without arrangement of the injection means 2,... and the lifting pipes 3,... in the area A1.SELECTED DRAWING: Figure 1
