RAIN WATER TREATMENT EQUIPMENT AND RAINWATER TREATMENT METHOD FOR SOIL CLEANING FACILITY THAT CLEANS CONTAMINATED SOIL

摘要

PROBLEM TO BE SOLVED: To provide a means that enables a treatment of rainwater that fell on a cleaning facility site of a closed system soil cleaning facility without discharging a soil pollutant untreated.SOLUTION: Rainwater treatment equipment S1 treats rainwater that fell on the facility site 1 where a closed system soil treatment facility 2 is arranged. The rainwater treatment equipment S1 comprises: a rainwater storage tank 4; a sand housing part 5; a rainwater ditch 11; a rainwater supply apparatus 12; a rainwater recycling passage 13; and a water level holding device 14. The sand housing part 5 houses sand in an internal space thereof, and the rainwater storage tank 4 stores rainwater that fell on the facility site 1 and the sand housing part 5. The rainwater ditch 11 is arranged adjacent to an outside surface of a left side wall 8 of the sand housing part 4, and the internal space thereof communicates with an internal space of the sand housing part 5 via a communication hole. The water level holding device 14 holds a water level inside the rainwater ditch 11 at an upper end position of soaked sand. The upper end position of soaked sand is set so that a sand layer between the upper end portion of soaked sand and an upper face position of the sand layer in the sand housing part forms a capillary fringe.SELECTED DRAWING: Figure 1