On premise of GSJ in Tsukuba, we have 4 wells for continuous ground water level observation. The depth of wells are 60m,150m,300m and 600m. The 600m well had been drilled in 1998. At that time, hydrological and geological research using drilling hole had been done.
By the results of those researches, it is observed that the depth of basement is 573m. There are several obvious aquifers at this point, and pumping tests and water quality analysis had been carried out at 5 aquifers. Ground waters in shallow aquifers are originate in precipitation, and deeper ones are influenced by old sea water.
