We consider wastewater treatment as a water use because it is so interconnected with the other uses of water.
Definition of Centripetal Force. Centripetal force is a force that makes an object follow a curved path. The direction of the force is oriented at a right angle to the direction of travel of the object, toward the center of the circle along which the object is moving.
In the case of a rotating system, the centripetal force pulls the mass inward to follow a curved path, while the mass appears to push outward due to its inertia. In each of these cases, though, there is only one real force being applied, while the other is only an apparent force. Additional resources.