RAIN WATER SEEPAGE PIT AND FILTER FOR RAIN WATER SEEPAGE PIT

PROBLEM TO BE SOLVED: To save labor for maintenance by extending intervals in which solid matters are removed from a filter for rain water seepage pint while a maintenance function for easily taking out an inner filter 12 is utilized since rain water efficiently flows from the inner filter 12 to an outer filter 14 and the solid matters are accumulated not only in the inner filter 12 but also between the inner filter 12 and the outer filter 14. SOLUTION: This filter 10 for the rain water seepage pit is formed by stacking the inner filter 12 in the outer filter 14. The height of the inner filter 12 is lower than the height of the outer filter 14, and a clearance is formed between the upper end of the inner filter 12 and the upper end of the outer filter 14. The solid matters contained in the rain water is removed first by the inner filter 12. Then, when the inside of the inner filter 12 is filled with the solid matters, the rain water flows into the outer filter 14 through the clearance, namely, an overflow passage 34, and the solid matters are removed by the outer filter 14. COPYRIGHT: (C)2006,JPO&NCIPI