Abstract
We summarized hydrogeological features around 533 landfill sites for industrial wastes in Hokkaido based on the existing data and geological survey around them. In this study, the hydrogeological features around the landfill sites were classified into four types, impermeable layer type, permeable layer type, surface permeable-subsurface impermeable type and heterogeneous permeability type. Since most of the landfill sites locate on permeable deposits, such as Alluvium and pyroclastic deposit, 56.3% of the landfill sites were classified to the permeable layer type. Infiltration water from the landfill sites situated on the permeable layer type would be easy to permeate vertically. If toxic substances are contained in the infiltration water, the widespread pollution would occur. In this case, the observations of the groundwater quality play an important role to recognize the pollution immediately. On the other hand, 26.5% of the landfill sites locate on the impermeable layer type which is hard to cause the widespread pollution. These hydrogeological data about each landfill site would provide useful information to perform the prompt circumstantial judgments for prevention of the widespread pollution.
