Real Time Control

Aquafin developed a management strategy for a smart control of sewerage systems.

Flanders still has a good number of combined sewerage systems that carry rainwater along with domestic wastewater to treatment plants. In heavy rain, these mixed sewerage systems fill up very unevenly. This is normal, as it rarely rains equally in different locations and the system’s capacity is not the same everywhere. As a result, the sewer can flood in critical places, which leads to overflow despite the fact that perhaps only two thirds of the storage capacity in the system has been used.

Real-time intervention

In an overflow, water which would otherwise cause flooding can still be drained to the nearby watercourses. Despite being diluted with rainwater, this waste is still highly polluted and can often have a big impact on the environment. To reduce this impact, Aquafin developed a management strategy for sewerage systems: RTC. With the help of sensors, controllers and regulators, real time intervention enables the entire sewerage system to continuously fill up as evenly as possible. This dynamic control turns passive underground sewers into a smart infrastructure that can be monitored remotely. That's why we speak of smart sewers.

For this purpose, the filling rate of the system must first be calculated based on a water height measurement. At strategic locations, control structures such as valves and sliders are applied to hold back or divert the water. We can also activate existing pumping stations. Sensors measure the water levels and the flow in order to control these structures using an algorithm so that the system fills up in a balanced way.

Dynamic steering

To make the system failsafe, Aquafin also incorporated safety measures at various levels and locations. It is innovative as it uses modern techniques such as recording and forwarding measurement data online and the decision-making commands do not require human interaction.

Fundamentally, a sewerage system is a static infrastructure. But by dynamically steering them, we can make the most of the hydraulic potential and the available storage. The measurements in the sewerage system that are digitally transmitted to a central location are used to improve processes by releasing algorithms. So we can not only reduce overflow, we also learn about the dynamics of what is happening underground, notably the filling level and storage capacity of the sewerage system. Faced with climate change and our need to adapt to it, these data are very instructive. Thanks to real-time camera images, we can also now monitor and adjust from a distance and above the ground.