Start of Marthalen borehole

In early February, drilling began in Marthalen. This is the second deep borehole to be drilled in the Zürich Nordost siting region as part of Stage 3 of the ongoing site selection process.

The borehole is expected to reach a depth of 1090 metres – Nagra applied for a maximum depth of 2000 metres. Drilling a borehole takes around six to nine months.

Data for this region are already available from an earlier borehole investigation conducted in the community of Benken. In addition, drilling at the Trüllikon 1 borehole has been ongoing since August 2019.

The Federal Government has the lead in the site selection process and gave Nagra the mandate to conduct deep borehole investigations in all three potential siting regions. The boreholes will complete the overall geological picture of the siting regions. The resulting scientific basis will underpin the selection of the safest site for a repository. The boreholes investigate the thickness, tightness and composition of the Opalinus Clay host rock in which the repository will eventually be constructed.

Nagra has set up a hotline for questions and concerns of local residents and other interested persons. It is free and operates 24/7 (0800 437 333). In Marthalen, there will also be a visitors’ pavilion, open days and tours of the drill site.

More information is available here.