Abstract
In the Tomitaka abandoned mine, mine drainage containing arsenic has drained into the sea without any processing and a neutralizing process is discussed to be necessary. From the field study, boring investigation and the existing data, the rock between the Umehi fault and Nikohi fault is assumed to be a high permeability zone. It is considered that precipitation infiltrates from mountain-side of Mt. Daiosan, groundwater passes through unsaturated high permeability zone and then flows into the lower rivers around Mt. Daiosan and mine levels. The numerical model is built based on the conceptual model containing the influence of precipitation on both mine drainage flow rate and groundwater level. As the result is nearly consistent with the measured value, the conceptual model is thought to be moderate.
