Water infrastructure - the importance of proactive inspection and maintenance

Water infrastructure plays a critical role in the way we function as a society. From the water we drink to the treatment of our sewage, without adequate storage, processing or pipeline facilities, our everyday lives would be greatly compromised.

By Hannah Pollock?- Consulting Engineer, Duratec

A significant proportion of Australia’s water?infrastructure was built prior to 1970, which mean original 50-year design life. With the explosion in Australia’s population over the past few decades, it is critical that we continue to have access to high-quality water so that it can meet the population’s needs. Water authorities, therefore, are faced with various challenges in determining and maintaining the condition of their water assets.

Taking an asset offline to facilitate an inspection, however, often results in logistical challenges in arranging for diversions to ensure an uninterrupted service for customers. Some assets are near impossible to take offline due to high demand, impossibility of diversion or the high cost?of implementing temporary access to alternative water sources. Consequently, defects are often only identified once the deterioration has progressed beyond the point?of small-scale repairs and resulted in the need to conduct urgent, full-scale, reactive remediation.

While some steel and concrete defects can be identified through visual surveys while an asset is online — mainly via divers and remote operated vehicles — identification of an asset’s primary deterioration mechanism often requires in-depth testing and analysis. For example, underside corrosion of a steel, potable water tank’s floor plates is a major risk to the integrity and operation of a tank. This form of corrosion often goes undetected in visual inspections?and can only be identified using specialist testing methods, such as magnetic flux leakage scanning or when corrosion has resulted in full through-section loss. In these cases, it is likely that more substernal repairs would be required to bring the asset back to acceptable standards.

By identifying and understanding an asset’s deterioration mechanism(s), proactive inspection and maintenance plans can minimise the asset’s downtime and limit disruptions to service. Such plans also allow for defects to be addressed before critical deterioration limits are reached, mitigating costly and unexpected remediation works.

Considering the criticality of water infrastructure and the necessity for an uninterrupted service, the ability to limit an asset’s time offline through the early detection and rectification of defects is of utmost importance.

About the author

Hannah Pollock is a consulting engineer?in Duratec’s Technical Services division.?Hannah studied materials engineering?at university and has a keen interest in water infrastructure, materials durability and concrete condition assessments.