From WWTP to RAS

Water needs to be moved, treated, measured and monitored. Pumps need to be controlled, sensors need to provide accurate readings, alarms need to detect deviations, and critical processes need to operate around the clock.

This could be a description of a modern water and wastewater facility. But it could just as easily describe a land-based aquaculture facility.

The differences between the two are clear. In aquaculture, biology becomes a decisive factor. Yet there are also significant technical similarities – and lessons from the water and wastewater sector that may prove increasingly relevant as aquaculture facilities become more complex.

”There are clear differences between a water and wastewater facility and a RAS facility. But when we look at the underlying technology and systems, many of the challenges are familiar. We are dealing with large volumes of water, critical processes, extensive instrumentation and the need for stable, 24/7 operation,” says Aleksander Mork-Knudsen, Head of Aquaculture at Guard Automation.

From individual components to one system

A modern RAS facility consists of numerous technical processes that must work together to maintain a stable environment for the fish.

Pumps, valves, oxygenation systems, water treatment equipment, sensors, variable frequency drives and control systems may all come from different suppliers. Each component may work perfectly well in isolation. But for the people operating the facility, it is the system as a whole that needs to work.

This is a challenge the water and wastewater sector knows well.

Over several decades, the sector has moved towards increasingly integrated control systems, where large amounts of instrumentation and technical equipment are monitored and controlled as parts of a single process.

That changes the question. It is no longer simply whether an individual component works, but what happens to the rest of the process when it does not.

”In water and wastewater, we have learned that it is not enough for each individual component to work. You need to understand what happens to the rest of the process when one component fails. That way of thinking becomes even more important when you have live fish in the system,” says Mork-Knudsen.

When technical failures can have biological consequences

This is also where one of the most important differences between traditional water processes and aquaculture becomes clear:

The fish cannot be put on hold while a technical fault is being fixed.

In a land-based aquaculture facility, water quality and other environmental conditions are closely linked to technical systems. The more control we take over the fish’s environment, the more dependent we become on the technology that maintains it.

Research funded by the Norwegian Seafood Research Fund (FHF) has highlighted the importance of maintaining good control of water quality in RAS facilities, as well as the need for accurate and reliable sensors for key water quality parameters.

Automation and control systems therefore become more than a matter of efficient production. Technical robustness also becomes part of managing biological risk.

A facility must be able to handle failure

No complex technical system should be built on the assumption that nothing will fail.

A sensor can report an incorrect value. A pump can stop. Communication can be lost. A valve can become stuck in the wrong position.

The important question is therefore not only how the facility performs when everything goes according to plan, but how it behaves when something does not.

This is where redundancy, alarm management and well-designed control strategies come into play. Which functions are critical enough to require backup capacity? What should the system do automatically if a component fails? Which events require immediate attention from an operator?

”The goal is not to build a facility where we assume that nothing can go wrong. The goal is to understand what can go wrong and make sure the facility handles it in a controlled way. In aquaculture, this is particularly important because a technical event can quickly develop into a biological event,” says Mork-Knudsen.

The technology must withstand the environment

Operational reliability is not only about control systems and software. The equipment also needs to perform in a demanding physical environment.

High humidity, condensation, salt and chemicals can place significant demands on sensors, instrumentation, control cabinets, cabling and electrical installations. Oxygen handling also requires particular attention. The choice of components, materials, enclosure ratings and field installation therefore becomes part of overall operational reliability.

”It is not only about designing a good control system. It is also about selecting the right components, enclosure ratings and materials, and ensuring proper execution in the field. This is an important part of the industrial expertise that comes from working with automation and critical infrastructure,” says Mork-Knudsen.

More data does not necessarily mean more insight

At the same time, aquaculture facilities are becoming increasingly instrumented.

Temperature, pH, oxygen, water flow and a wide range of other parameters can be monitored continuously. Advances in sensor technology are making more information about both the process and the environment available to operators.

But more data points do not automatically lead to better decisions.

What matters is whether the information gives the operator an accurate understanding of what is actually happening – and whether it arrives in time to act.

This places demands on measurement quality, on how data from different systems is connected, and on how information is presented.

An operator does not necessarily need more graphs and more alarms. The operator needs to understand what is happening, how serious it is, and what requires attention.

”A well-automated facility is not one where the operator receives as much data as possible. It is one where the operator receives the right information in time to act on it,” says Mork-Knudsen.

When more technology needs to create less complexity

The move towards more instrumentation, automation and digitalisation will continue. At the same time, production systems are becoming more advanced and increasingly interconnected.

But the goal cannot be technology for technology’s sake.

With every new sensor, component and digital solution, the number of relationships the system needs to manage also increases. Technology creates value only when this complexity is translated into better control, clearer decision-making and more stable operations.

This is where experience from the water and wastewater sector can be relevant.

Not because solutions can simply be copied from a water and wastewater facility into a RAS facility. Biology means the two must be understood differently. But the principles of process control, system integration, redundancy and the management of critical processes have been developed and refined over decades.

Guard Automation has worked with automation and control systems in the water and wastewater sector for more than 40 years and is now bringing this experience into its growing focus on aquaculture.

Because as the aquaculture industry takes greater control over the environment in which fish live, it also takes on greater responsibility for the systems that sustain it.

From WWTP to RAS, the biological leap is significant. But technologically, there are lessons worth bringing along.