What must be done to prevent the ingress of sea water into a potable water tank?

To prevent the ingress of sea water into a potable water tank, proper venting is essential. The venting system allows for the equalization of pressure within the tank as water is drawn from it or added to it, which helps prevent the intrusion of sea water caused by changes in pressure. When a tank is filled or emptied, without proper venting, a vacuum or pressure differential could occur, potentially allowing sea water or contaminants to be drawn into the tank.

Effective venting also ensures that air can circulate freely, which is crucial to maintaining the integrity and quality of the potable water. It mitigates the risk of back-siphonage and helps avoid any contamination from external sources, such as sea water, which could compromise the safety of the potable water supply.

In contrast, while using stronger materials and regular inspections are important for the overall maintenance and integrity of the tank, they do not directly address the issue of preventing sea water ingress as effectively as proper venting does. Reducing water temperature does not have a significant impact on preventing seawater from entering the tank either; it might influence biological growth in stored water but does not address ingress issues.