It was not an easy decision for him: “We had 100 workers trained as engineers and 35 excavators about to start. Then the entire operation came to a standstill. Just try explaining that to the client.”

With expert supervision, several measures were taken, such as the installation of overpressure cabins on the excavators. No work was carried out for two months, and the expenses were high. However, with concentrations of 4,000 ppm recorded, it was obvious that there was no other choice: anything greater than 600 ppm is deadly.

According to Bas, “Given the support I received when we halted operations, the dedication of all involved to take the proper measures, and the cooperation of Boskalis, I am convinced that our organization is changing and that NINA is effective. It is extremely reassuring to know that people will back you up when you are faced with these kinds of decisions.”