Mr.Diedericks asked me to give more information on the type of dams concerned and also who is interested in my company for the preventive surveillance measure.
Our dams are made of the following materials; concrete ,metal marraine. Our divers would be the ones who are first concerned. They do maintenance and repair dams. They asked me if there would be some type of preventive surveillance measures to detect cracks. This question arosed because I am planning to measure their noise ex- posure to pneumatic and hydraulic tools underwater. They have heard, that may be using ultrasounds it would be of some help to detect cracks in our dams.
Alain Quilliam Industrial hygiene consultant Hydro-Québec Direction Santé sécurité