Purifying water at a small scale is a big challenge!

We have quite some experience in water purification on a large scale. For example, recently we started to use a new installation at our distribution site in Halle. After these large volumes, we are now also looking at the possibilities of working on a smaller scale.

Small volumes, big challenges

Our more than 500 own stores - Colruyt, OKay, Dreamland, Bike Republic, etc. - together account for more than 30% of our water consumption. So there is a large profit to be made there. Lize Linclau: "Given the geographical spread and the small volumes, this is quite challenging. That's why we take up this project within our R&D department."

"A lot of technology for water purification at a large scale can be found on the market. We are investigating if it's economically interesting to scale that technology down for our smaller volumes. Another important requirement is being able to monitor the purification quality live."

From rainwater to drinking water

At this moment, we are already using rainwater to flush the toilets in our stores. But there is a margin. After all, stores have large roof surfaces that can collect much rainwater. How can it be put to good use?

"To answer that question, we currently have two projects going. At our distribution centre in Ollignies (Hainaut), we purify 5m³ a day. By comparison: the installation at Stroppen, our meat processing site, treats that quantity hourly."

We also have a test going at Roeselare's Bio-Planet. There, the volume is even smaller. We are purifying rainwater to drinking water but do not yet offer it as such. Before we can start implementing this effectively, we have to go through an extensive validation process."

On the search for a uniform solution

"We are looking for an overall solution that works everywhere so that we do not have to conduct the same study at every site. That means standardising, plug & play, solid but modular at the same time. For example, other components will end up in the rainwater in an agricultural area than close to a highway.

The business case becomes a little easier at so-called combi-sites - think of a Colruyt store next to a branch of Dreamland or Bike Republic. "There, we can work with larger volumes. We are also looking at our projects where we are building apartments or houses next to a store." But, collaborations are also possible. 'In Veurne, at the new industrial site Suikerpark, two water circuits of different quality will be installed. There, we want to put our rainwater to good use." An opportunity.

Convinced of the need

Many suppliers wonder why we are starting on such a small scale. Lize: "Our water efforts are primarily based on 'conviction'. After all, many small efforts make a big impact.

"Of course, economic efficiency is crucial in every assessment but the new water purification installation at the Dassenveld distribution centre would never have been built if management had only looked at the figures. If you are a retailer committed to sustainability, you have to look at it holistically - in a broader context."