NX Filtration’s hollow fiber NF membranes enable autonomous drinking water production at Pampus

Fort Island Pampus turns the surrounding water from the IJmeer into its own drinking water. To do so, it is installing a purification system with a unique combination of techniques. Will we see more offgrid solutions like this in the future now that drinking water companies are sounding the alarm?
"Since the construction of Pampus in the late 19th century as part of the Defence Line of Amsterdam, everything has been about water," starts René Dijkstra, head of fundraising and partnerships for the fort island. "By flooding controlled areas, water was primarily a defense mechanism. Because of the lack of a water supply, the 200 men on Pampus at the time were already making their own drinking water by collecting rain and filtering it with gravel and sand. Furthermore, the island had one of the earliest forms of sewage system as low tide flushed the toilets clean. Pampus now wants to continue that tradition of self-sufficiency and innovation. But with the latest technology."

Water by boat

Fort Island Pampus wants to be self-sufficient and climate-neutral by 2024. That means its own energy, food and water supply. Currently, Pampus is supplied daily with 3,000 gallons of water that is brought to the island by tanker from the shore. This is labour-intensive, time-consuming and also done with fossil fuels. And that's what Pampus wants to get rid of.

Surface water from the IJmeer

To that end, Pampus had a couple of options. The first is a pipeline from the shore to the island. But that's complicated and becomes expensive quickly. The second option is pumping well water. But after tests, this appeared to contain too many metals, making purification difficult. The option of treating rainwater also proved not to be an option due to harmful substances. "A fourth source ultimately proved the most stable: surface water from the IJmeer," says Rob Borgerink of water treatment specialist Jotem water solutions. "But let's be clear: you can't just make your own drinking water. By law, only drinking water companies are entitled to do so. Nevertheless, we have been working with them to explore the options for Pampus."

Membranes and UV-C disinfection

System integrator Jotem water solutions use a combination of three techniques for this water treatment system: a sand filter, a hollow-fiber nanofiltration membrane and a validated UV system. "Our nanofiltration membrane blocks pollutant particles while allowing many beneficial minerals to pass through." says Christian Beuzel of NX Filtration. "But when it comes to drinking water, you want to be 100 percent sure." Therefore, after filtering, the water is treated with UV-C light, a technique supplied by Van Remmen UV Technology. "It is the unique combination of techniques and mutual cooperation that makes this project so special," said Ton van Remmen. "Nowhere in the Netherlands is water treated in this way."

Energy efficient

The technology works, say all involved. With "delicious IJmeer water", indistinguishable from the water from your tap, as a result. The system operates completely independently of the shore and should eventually run on solar power, supported by batteries. But that doesn't mean Pampus is there yet. "The legal aspect is really the biggest bump," says Van Remmen. "In the coming months, we have to demonstrate to policymakers that our safe water can also be formally used as drinking water." And that's a long process. We will probably have to test throughout 2023 to see how the seasons affect water quality."

Drinking water problem

Late last month, drinking water companies sounded the alarm. Drought, salinization and pollution are pushing water systems to their limits, which could lead to a shortage of drinking water in the Netherlands within a few years. "Drinking water is a scarce resource," Beuzel said. "That is why it is important that we start looking at alternatives for certain sectors. In industry, for example, it is not always necessary to use drinking water for certain processes."

Offgrid for islands and remote areas

Yet the solution to the drinking water problem in the Netherlands probably does not reside in off grid plants that treat surface water locally. "Having a drinking water connection is always the most efficient solution." Borgerink says. "Offgrid solutions are only meant for places where there is no such connection, for example on
Pampus or for remote communities in other places in the world."
Beuzel replies, "However, we are looking at small-scale, decentralized systems at the street and neighbourhood level to reuse water locally as effectively as possible and still have economies of scale. We are also working on water production sites for industry as an alternative to high-quality drinking water, and this can quickly be more affordable locally than the price of drinking water. This is how we disclose drinking water for consumers. We also see drinking water companies looking at alternatives to groundwater. Surface water will be used more often for drinking water production.

Pampus is a frontrunner in sustainable drinking water production. Not just anywhere is there a lake as a source of water. So, a big part of the solution to our drinking water problem, in my opinion, lies in smarter management of supply and demand."

Eye of the storm

Once the drinking water system is on the fort island, Dijkstra hopes to create more awareness about drinking water among the Pampus public. "Drinking water is so obvious to us," says Dijkstra. "While it takes a lot to turn water into actual drinking water. On Pampus we want to give the purification plant a prominent place, so people can see what's involved."

In any case, the island already provides a stage for technologies we may desperately need in the future. "The world is in a kind of perfect storm," says Dijkstra. "We are facing shortages of gas, materials and water. It is evident from all of this that we are running into natural limits. To deal with them, we need creative solutions. Let Pampus be the eye in the storm where these solutions are pioneered."

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