In the Netherlands, clean drinking water is currently used to flush toilets, which is a waste, right? OOW wants to change this and that is why they have designed a revolutionary water purification system. This system saves up to 40% water and also reuses the heat from the showers to heat new shower water. The front of the purification container is made of glass, so that visitors can see the process.

During the Zwarte Cross festival, OOW tested whether two buffer tanks of 7 m³ were sufficient to supply all 33 toilets with water during peak hours. Although the system was able to purify enough water, the buffer capacity was insufficient; at least 10 m³ is required. An unexpected problem was the high level of contamination of the shower water, probably caused by sunscreen.

Visitors generally understood the process of water purification, but there were some misconceptions, such as the idea that the purified water was used for showering.

The next steps include research into the influence of sunscreen on the process and increasing the buffer capacity to function better during peak hours.