WATER COLLECTING UNDERGROUND STRUCTURE OF GREEN AND GREEN AGRICULTURAL CHEMICAL SEPTIC TANK AND GREEN AGRICULTURAL CHEMICAL ELIMINATION FACILITY

摘要

PROBLEM TO BE SOLVED: To contrive saving the execution of work. SOLUTION: The bottom of an underground yard 10 under the green is slanted at the lowermost depth at the central part of the bottom, thereby forming a slanted surface of the surrounding bottom 12. The inside area of the underground yard 10 is covered with an impervious sheet 12. A trunk line of an aqueous duct is laid out on the lower-most depth 11 of the bottom. A single particle crushed stone layer is provided on the lower layer of the underground yard 10 and a mixed sand layer is provided thereon. An agricultural chemical septic tank is formed with one septic tank 100 provided with a particulate activated coal-based filter layer where a small gravel layer C is provided on the lower layer of the tank. An inflow pipe 200, whose end is opened, is provided on the upper part of the tank. There is provided a drain pipe 300 whose one end is opened in the small gravel layer and whose other end is opened outside the tank. An overflow pipe 400, which is branched from on the way of the drain pipe 300 and opens its pipe end in the upper part of the tank, is provided on the drain pipe 300. Their underground structure of the green and the agricultural chemical septic tank are connected with each other, thereby constituting an agricultural chemical removable facility.