Hydrogeological characteristics of the test bed for the researches on subsurface environmental management in Korea

The S ubsurface Environmental Management (SEM) research center has been researching the system for diagnosing, evaluating , and predicting contamination paths and pollution in the underground environment since 2018 . The t est bed to develop on-site application technology is established in Wabu , Namyangju , Korea . The survey of basic data on topography, geology, hydrology, and weather was conducted first. D rilling survey also had been performed for geological properties. The top five meters is a colluvial alluvial layer , and weathered zone is up to about 4 0 ~50 m below the surface. The major bedrock of the test bed is the banded gneiss of the Kyonggi gneiss complex . B ed rock was highly fractured and has a few faults. G roundwater investigation including long -term monitoring for alluvial and bedrock wells to find out hydrogeological characteristics of the site was conducted . As a result of the pumping tests, the values of hydraulic conductivity are about 2×10 -5 cm/sec for weathered zone and 2×10 - 5 cm/sec for bed rock . Groundwater flows in a direction consistent with the topography in bedrock aquifer , but it is influenced by pumping in weathered zone. A dditional hydraulic tests are planned such as groundwater velocity measurement and tracer test for the rock fractured zone. The test facility of SEM research center will be designed in the form of multi- level monitoring wells network considering the hydrogeological properties .

Acknowledgement : This work was supported by Korea Environment Industry & Technology Institute (KEITI) through Subsurface Environmental Management (SEM) Project, funded by Korea Ministry of Environment (MOE) (2018002440002).