The number of people working in HADES on a daily basis is limited. Members of the technical team go down there most often. To ensure that all the systems run properly, they work with specialised companies carrying out the necessary checks and doing regular maintenance.
The members of the EURIDICE technical team, in consultation with the scientists, set up experiments and the measuring equipment to monitor them. The first step is to drill holes through the concrete wall of the gallery and into the clay. This is also the technique used to take clay samples for analysis in the above-ground laboratories. The EURIDICE technical team can make boreholes with a diameter of between 10 centimetres and about half a metre, up to 40 metres in length. Excavation and construction of galleries requires contractors with experience in underground infrastructure works, however.
The scientists who conduct the research do not need to go underground every day to monitor their experiments. They oversee setting up an experiment but once it is under way, the data is often automatically recorded and available online via the network. They do go down to the laboratory regularly to take samples or to check that their experiments are running smoothly.