침출수오염운 거동 평가를 위한 사용종료 비위생매립지의 수리지질학적 특성 사례연구

초록

This study aimed at evaluating the basic hydrogeological characteristics in the subsoil of a closed landfill site, a valley landfill with no liner system, that may affect the potential leachate plume formation and migration in receiving groundwater system. The physicochemical properties of soils and the hydraulic properties of aquifer materials were examined. Also the historic aerial photographs were inspected to identify the change of land use. The high leachate plume formation potential during rainy season was considered from the large fluctuation of groundwater level with the rainfall. The hydraulic conductivity ranged from 1.15 ´ 10-4 to 4.69 ´ 10-2 cm/sec with the slug and pumping tests. The slug test also revealed that the hydraulic conductivity increased about 10 times with the increase of depth owing to the existence of high permeable sandy aquifer material that may cause enhancing the leachate plume migration. The high longitudinal dispersion index of about 1.0 m, when compared to its usual range from 0.01 to 0.1 m with the similar scale aquifers, suggested that the high potential of leachate plume migration to a great distance could be occurred.

키워드