During this internship at OTV SUD, I have discovered the job of Project Engineer. Indeed, during the entire period of the internship I had the chance to participate in the response to a call for tender for a drinking water production plant. A response to a call for tenders involves several stages: reading and analyzing the specifications to define the issues and requirements of the project, the choice and sizing of the treatment process which are the result of long reflection to achieve the required objectives, consulting suppliers to find out their recommendations and integrate their offer into the project, costing the equipment to determine the internal cost price of the project and the valuation of the offer.