Stephan Van Hoof

Stephan Van Hoof came to Blue Foot the long way round. For the better part of 20 years he sold and engineered capillary ultrafiltration membranes (the hollow-fibre kind, where the water flows from the inside out) at Norit and then Pentair X-Flow in the Netherlands, so when the Belgian research institute VITO asked him around 2015 to benchmark a strange new membrane it was thinking of spinning out, he was the obvious skeptic to hand it to. The membrane was submerged, outside-in and flat, which as he puts it was "a complete 180" from everything he knew. He came away impressed, did the analysis, and then went off to do other things entirely. In 2020 the shareholders called him back to actually run the company, and he took the job because it sat exactly where he likes to be, in between the technology and the commercial side.

Stephan Van Hoof's whole pitch rests on one unusual physical property: this membrane can be cleaned by pushing water backwards through it, hard. Most flat-sheet membranes are a thin film glued or spot-welded onto a backing plate, so you cannot really reverse the flow without peeling the film off. Blue Foot's IPC membrane (Integrated Permeate Channel) is instead cast onto a 3D textile and fully anchored into it on both sides, which lets the company apply up to 2 bar of pressure the other way to genuinely backwash it. Every single sheet they make is tested at that 2 bar on the way out of the factory, and that robustness is why Stephan is comfortable calling it an "unbreakable" membrane that takes the best of flat-sheet, tubular and ceramic designs at once.

Stephan Van Hoof is clear about why that toughness is worth paying for, and it is not the spec sheet, it is the bad Monday morning. In a wastewater plant something will eventually go wrong, somebody drains a tank into the bioreactor and upsets it, and the real question is how fast you recover. A membrane you can hose backwards stays cleaner, runs at higher throughput, needs far less aeration (he reckons roughly half that of a regular flat sheet, which means lower energy and lower CO2) and packs into a much smaller footprint. For his customers, who are breweries, slaughterhouses and rendering plants that are in the business of making beer or widgets and not the business of treating water, a smaller, more forgiving box at the back of the lot is the entire point. As he likes to say, water is your license to operate.

Stephan Van Hoof learned the hard half of the job long before Blue Foot, and it shaped how he sells. The first slide of every technical training he ran back at Norit said the same thing: a membrane is not a box. You cannot just ship someone a module and hope it works, because it will fail, so the first thing he did as CEO was drop the distributor model and build a clean network of OEM partnerships where his engineers sit with the customer's process engineers and hand over the implementation know-how, not just the hardware. That patience is the same lesson he has for anyone raising money in water: this is not software, the sector is slow and project-driven, recurring revenue builds month by painful month, and the investors who do best are the ones who came in knowing that. His own one-line advice to founders is blunter than all of it:

“I think the most important thing is never give up. Small company, startup, scale up, it is difficult. There's many challenges. You will have a lot of setbacks, but never give up.”

Stephan Van Hoof has put real money behind that conviction: under him Blue Foot closed a EUR 15 million growth round, led by the Circular Innovation Fund, to expand its Belgian manufacturing and finally staff up the sales organisation he had kept deliberately, frustratingly thin. You can hear the full story on his (don't) Waste Water episode, and the wider water-reuse context lives over on the Leviathan database.