[en] The bedrock in the study area consists of Precambrian rapakivi granite with its varieties. The rock type is mostly fresh and strong. Alteration and weathering of the rock material occurs only in association with the fracturing. Fracture properties - orientation, aperture, hydraulic conductivity, filling and weathering - have been treated with respect to final disposal and siting of the repository. The results achieved have been compared with corresponding results obtained in Finland and other countries. Two vertical and one horizontal or gently dipping fracture sets typical of granitic rocks are present, the last mentioned of which are dominant. The hydraulic conductivity of the fractures varies greatly, generally between k=10^-9 and 10^-5 m/s, owing to, e.g. the state of stress in the rock, cementation and filling of the fractures. According to the sorption tests, weathering of the fracture surfaces as well as the filling material of the fractures has been found to increase remarkably the sorption capacity of the rock mass. A three-dimensional engineering geological model has been prepared of the bedrock. According to the model, three gently dipping fracture zones divide the rock mass into different zones of intact and broken rock. The zones are considered as hydraulic units, for which hydraulic conductivity and effective porosity were determined. In the fracture zones the values for these are in the order of k = 10^-6 m/s and 0 = 4 . 10^-3 average. In the intact rock zones, the corresponding values are generally one decade less. The study area has two separate groundwater zones in the bedrock. The surface parat of the groundwater is fresh, with relic seawater of the Baltic Sea below; its salinity reaches some 1% at the maximum. The main fracture zones seem to determine the groundwater level and flow. The water flow is mainly concentrated to the fresh groundwater zone, the saline groundwater being nearly stagnant. The construction properties of the bedrock have been evaluated by international rock classifications. According to these, the intact rock mass is well suited for construction purposes