A Case Study on Long-term Groundwater Level Measurement Method and Water Level Fluctuation Characteristics in Coastal Landfill

In this study, the long-term groundwater level measurement method and three-month groundwater level fluctuation characteristics in the coastal landfill were conducted. The long-term groundwater measurement system consists of a lower cap, non-porous pipe, strainer, and protection box, and a pressure-type water level gauge (TD Diver) with its own built-in battery is recommended. As a result of long-term groundwater level measurements at coastal landfill sites in the same area, there was significant variation in groundwater levels due to topographical or geological factors, tide, rainfall, and landfill materials or existed underground structures. The effect of tide level is different for each location, and that is not significant if it is located very close to the coast. Rising water levels were observed at all sites following rainfall. However, the amount of increase in groundwater level and the rate of rise and fall over time differ greatly for each site. Since the groundwater level is an important factor related to water leakage in the earth retaining wall and impervious barrier of coastal landfills, we recommend measurements for at least three months, equivalent to one quarter, and a design that reflects this.