As the regulator has highlighted, not all water companies have sufficient understanding of the condition and resilience of their existing assets, or how this is likely to evolve over the longer term. Deeper knowledge about assets means utilities can be more efficient in their maintenance and replacement activity, reducing the risk of service failure to customers.
In my 30 years in the water industry, I have installed, restored and maintained a wide range of wastewater treatment equipment and have identified many ways to drive efficiency and deliver major savings in both capital and operational outlay at many sites.
One option that is sometimes overlooked is the repurposing of older assets, which are typically longer lasting because they were over-engineered when investment was less constrained. The outer shells of most older concrete treatment tanks not only remain intact, but are strong and have plenty of life left to give.
While sometimes neglecting the potential of this legacy infrastructure, there is simultaneously a perception at large in the industry that an alternative wastewater treatment technology could be available in the next 20 years - but no one has yet pinpointed exactly what that is.
The water industry knows it urgently needs a technology that is available, robust, flexible and financially viable. My belief is that the solution is already here in the shape of modular offsite build - and it is cost positive.
In a recent project with Wessex Water, WPL retrofitted an existing circular sludge tank with WPL’s Hybrid-SAF cells, which proved significantly more cost-efficient than the trickling filters originally planned and doubled process capacity. The utility shared the site’s 2040 design horizon, ensuring the solution was futureproofed for anticipated population growth.
In our experience, the cost of traditional treatment plants is two to four times higher than modular build and the civil engineering work required means much longer is required onsite than for packaged plant installation. For WPL, asset specification is based on a 20-year lifecycle, which takes into account localized population growth and migration.