Definition - What does Water-Holding Structure mean?
A water-holding structure is a large water storage container for domestic or industrial use. These structures are available in many shapes and sizes. They can be vertical, horizontal, underground or potable. They are made of plastic, steel, fiberglass, stone or concrete. Water leakage, corrosion and bacterial growth are threats to water-holding structures.
Over time the water-holding structure can weaken or become damaged if corrosion is uncontrolled, leading to an undesired release of water into the environment.
Water-holding structures are also known as water storage tanks.
Corrosionpedia explains Water-Holding Structure
A water-holding structure is a reservoir that stores water for industrial, residential or firefighting purposes. These structures are similar to water storage tanks. Some are made from steel or concrete and therefore can corrode or leak if not properly protected internally from chlorinated water or externally from soil.
Corrosion occurs in steel water tanks due to an electric current passing from one point to another on the tank's inner surface. The tank wall acts as an anode and the water acts as a cathode. The anode loses electrons, thereby corroding the tank. If left untreated, this can cause water discoloration and tank wall leakage.
Factors that accelerate corrosion include:
- The tank’s interaction with interconnected components
- The corrosiveness of the environment
- Stray electrical currents
Water-holding structure corrosion is prevented with coatings or linings and cathodic protection. A coating on the structure's inner wall acts as a physical barrier between the wall and the water, which prevents the electron loss from the anodic wall. In cathodic protection, electrical currents are supplied from outside the tank to counterbalance the corrosion process inside the tank. It inhibits electron flow from the tank wall into the water, and therefore prevents corrosion. Corrosion of the tank's inner wall is also controlled by using corrosion-resistant materials and certain inhibiting chemicals.