To effectively clean ground water being contaminated by a volatile organic compound at low costs.
The well for cleaning ground water is equipped with a well casing 10 that has a first screen 11 for taking the ground water (A), a double tube 15 that is provided in the well casing 10 and is composed of an outer cylinder 13 and a column pump 14 (B), an aeration pipe 20 that aerates the ground water in the double tube 15 (C), and a branch pipe 19 that is connected to the upper end part of the column pump 14 to return one part of the pumped ground water into the outer cylinder 13 or the well casing 10 (D). In this case, a second screen 16 for introducing the ground water in the casing 10 to the outer cylinder 13 is provided in the outer cylinder 13, the lower end part of the column pump 14 is positioned at an upper location than the bottom part of the outer cylinder 13 and at a lower location than the second screen 16, the upper end part of the column pump 14 projects from the upper end part of the outer cylinder 13, and open end part of the aeration pipe 20 is positioned at the lower part of the column pump 14.
HIROKAWA MASAHIDE
HATTORI KAZU
