Borehole drilling for sewage disposal and rise of the hole's bottom at Asuka Station, East Antarctica

• Main Authors: 石沢 賢二, 竹内 貞男, 高橋 昭好, Kenji Ishizawa, Sadao Takeuchi, Akiyoshi Takahashi
• Format: Report
• Language: English
• Published: 国立極地研究所 1990
• Subjects: 62(*2); East Antarctica; Antarc*; Antarctica
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=8674; http://id.nii.ac.jp/1291/00008674/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=8674&item_no=1&attribute_id=18&file_no=1

あすか観測拠点の排水孔を基地から50mの位置にスチームドリルで掘削した。排水孔は, 直径40cm, 深さ27.5mである。掘削スピードは, 4m/hで, 造水および蒸気発生に使用した灯油の総量は, 110lであった。汚水は各タンクにためられた後, 特殊なヒーターで加温されたパイプを通って排水孔に捨てられる。排水孔の底面は最初の約5カ月で7m上昇したが, 上昇速度は, それ以降減少し, 3年間で594klを捨てて, 11.6m上昇した。雪面下の排水の浸透域の広がりは, 形状を円錐体と仮定すると半径は約13.7mになる。 A borehole for sewage disposal was drilled in the snow at Asuka Station (71°31′34″S, 24°08′17″E, 930m a. s. l.) in January 1987. The borehole, 400mm in diameter and 27.5m in depth, was drilled at 50m apart from the main hut using a steam drilling system. The drilling speed was 4m/h between the surface to 20m depth. Total amount of kerosene used for melting snow and steam generation was 110l. Sewage stored in three tanks is directed to the borehole through a heated pipe. The bottom of the borehole rose about 7m in first 5 months, but after that the rising speed decreased gradually. The bottom rose 11.6m up during a period of three years when 594kl waste water was discharged. If we assume the contaminated area is cone-shaped, the cone's radius is calculated as 13.7m.