When you say ‘spoil’, a lot of people assume you’re talking about something that has gone bad. But spoil is also a dredging term: it’s the muddy waste you’re left with when you deepen a riverbed or basin. And since spoil isn’t particularly fertile, there’s not much you can do with it – even though it costs a lot of time, money and emissions to dump it off site. And this is where Waterweg comes in, with a novel solution for this (literal) quagmire.

Why do students start a company? And how do you turn an idea into a reality? In this series, student entrepreneurs talk about the earliest stages of their new start-up. Part 4: Eva Aarts is the co-founder of Waterweg, a start-up that hopes to contribute to the circular economy by turning dredging spoil into tiles.


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Award-winning design

As a Liberal Arts & Sciences student at Erasmus University College, Eva Aarts became increasingly aware that we can’t afford to ignore climate change. “Our current linear economy doesn’t take into account how much havoc waste streams wreak on the planet,” says Eva. This inspired her to develop a revenue model in which the costs and damage caused by waste streams are converted into something that adds value to our economy. And it was one of the reasons why she decided to take part in the BlueCity Circular Challenge, a project that aims to extract value from seemingly worthless residual flows. Over the course of six weeks, students from different universities worked together on projects that aimed to find new uses for old residuals.

“I really enjoy studying, but I missed doing something tangible as well,” explains Eva. “Plus I wanted to show other people that it’s really possible to manufacture things using new processes that allow you to achieve ecological, social and economic returns without contributing to climate change.”

BlueCity has teamed up with a number of companies with residual flows, and the students were invited to select one of them for their project. And that’s how Eva and three other students ended up working with dredging spoil supplied by the Delfland District Water Board. The team immediately mucked in. They started by experimenting with the material: “We were like: ‘we might as well try stuff – after all, we’ve never used this material before, so we’ll see what happens and whether we can improve it.’ We started adding substances to the spoil, lime for instance, as well as pressing it and heating it. That’s how we discovered that we could turn this material into something very robust.” These experiments eventually resulted in a water-permeable tile, based on a row of interconnected strips. This design won the team the BlueCity Circular Challenge, as well as 5,000 euro in prize money.

Graciëlla van Hamersveld

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Still, it’s difficult to start a business with a mere 5,000 euro. Fortunately, the team landed an additional 25,000 after taking part in the Circular Innovation Challenge organised by the Dutch Water Authorities. They’re also in talks with a number of other potential investors, and they’re applying for as many grants and incentives as possible. “That may well be the only setback we’ve had so far. Applying to all these investment programmes and grant schemes takes a lot of time, and in the end you don’t always get it. That can be very frustrating occasionally.”

While these contacts may not always lead to an investment, Waterweg’s dredged tiles can count on a lot of interest, according to Eva. After all, dredging spoil is an issue the world over, and a lot of people find the concept of a circular economy very appealing. “The best part about this project is getting to talk to so many different people. The other day we met an architect who said he could see spoil being used as a construction material. Which motivates us to develop new applications for spoil in the future – walls or floors, for example.”

Pressing tiles

Image credit: Sanne van der Most

The next stage in Waterweg’s business plan is a pilot project, which will be launched in Delfland in August. The company will be using a mobile tile manufacturing plan to produce tiles on location. “Transporting the spoil to storage sites, and particularly storing the material, is quite expensive – and polluting too. We aim to avoid these economic and ecological costs by manufacturing on location, at the source.”

Spoil is removed from the river bed with the aid of dredgers, after which the material is usually stored in a container. It is then transferred to a storage location, where it basically no longer serves any useful purpose. “We will be sourcing this spoil directly to minimise the economic and ecological costs. We start by partially dewatering the spoil, after which we scoop it into a mould and press it in the shape of a tile. We’ve developed a prototype in which we’ve added a number of substances to the spoil. The end result is a sturdy but water-permeable tile. But this is another area where we aren’t done experimenting and improving just yet.”

Faith in your idea

Although the team have the required expertise to make a dredged tile, for the moment this hasn’t resulted in a finalised product. It’s a long-term project, since they have to wait a few years to see whether the tile continues to work as intended. Their ultimate goal is to set up a dedicated facility – which could take years to achieve. “I don’t mind that it’s a long-term project. If I can help solve a problem, I’m happy to do so. When it comes to making the transition towards a circular economy, we may as well start early. Because change is inevitable – it’s no use resisting. There are a lot of ways to approach a given problem, and everyone can contribute in the way that suits him or her best.”

And Eva’s solution was to take matters into her own hands. She definitely also sees her decision to do so as a moral choice, since the company isn’t turning a profit just yet. “You can’t make a quick buck with this kind of thing. We’re still in the start-up phase, when you’re mainly busy building a network – these things take time, of course. We’re all really committed to this project though, and we don’t mind being in it for the long haul. After all, you’re basically changing an entire sector.” However, according to Eva there’s lot of money to be made in the transition towards a circular economy in the longer term.

And Eva prefers to be in the driver’s seat while it happens. She suspects this has to do with a certain entrepreneurial spirit, but also with the focus on problem-solving she acquired during her studies. And she has one last tip for students who dream of starting their own business: “You need to have a strong drive to make it happen. Don’t be afraid to email people. And have faith in your idea. After all, if it’s not up to scratch, people will be sure to tell you. The entire process is a learning curve – you just need to take the plunge and go for it.”


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