Groundwater Studies in ONKALO

In ONKALO, the volume of the water leaking into the tunnel is measured and the characteristics of the groundwater studied. Groundwater studies form a part of the monitoring of the consequences of the construction.

Measurement of the volume of leak water is assisted by measuring weirs installed in the tunnel. A visual leak water analysis is also performed for the ONKALO roof and walls two times a year in order to find leak spots and to detect possible changes.

Besides the volume of leak water, the composition of groundwater is also examined in ONKALO. This is facilitated by groundwater stations and monitoring holes.