Hydrochemical disturbances measured in groundwater during the construction and operation of a large-scale underground facility in deep crystalline rock in Japan

Iwatsuki, Teruki  ; Hagiwara, Hiroki  ; Omori, Kazuaki; Munemoto, Takashi; Onoe, Hironori 

Changes of hydrochemical condition resulting from large-scale underground facility construction to 500 m depth in sedimentary and granitic rock were evaluated at the Mizunami Underground Research Laboratory (MIU), Japan. The investigation of hydrochemical impact around the facility suggests that an understanding of hydrogeological structures, including hydrogeological compartments prior to facility construction and the locating of shafts/galleries in low permeability rock area is essential to minimize hydrochemical disturbances.