Those responsible for the operation of a water utility's treatment and storage facility, or of a wastewater treatment and sanitation facility, whether they are owners or managers, must clearly define :
a) the objectives to be achieved, in particular the watertightness of the structures and the choice of class (which corresponds to the construction principle) ;
b) complementary functions :
compatibility with the liquids contained in the structures ;
resistance, durability, longevity ;
maintenance ;
suitability for installation and repair.
The essential requirements for the use of facilities containing either wastewater or water intended for human consumption, placed in their most general context, are to preserve the natural environment and the raw or drinking water, while avoiding contamination of the protected environments.