Using rainwater to wash cars and save the environment

The use of groundwater to wash cars is increasingly a problem now that droughts are more frequently occurring in the Netherlands. Fortunately, there is another way: washing cars using rainwater. That is what Bergschenhoek Water Technology (BWT) will be doing coming period: washing the commercial vehicles using rainwater and gaining experience with usage of the rainwater for cleaning and toilet flushing.

BWT calculated that this could save approximately 100,000 liters of clean tap water on an annual basis. Less soap will also be needed, because rainwater is soft, so less soap needs to be added to the water.

John Rook, director of BWT, about this use of rainwater: ‘Together with partner AAWS, we are increasingly involved in large-scale rainwater storage. Now that the Netherlands is drying out, less groundwater is available and thus the usage of rainwater as an alternative source of water is gaining interest. For example, rainwater usage to wash our company cars and flush our toilets. Coming period, we will be gaining experience with that.”

The rainwater is captured from some of the roofs of BWT warehouses. Next the rainwater is purified and stored in a tank, the RainWaterWall, specially developed by AAWS for this purpose. This tank takes little space and can be easily placed almost anywhere. At BWT, the tank is located next to an outer wall. From the tank, the rainwater is pumped through a professional purification system that takes care of purifying the rainwater meeting all standards required. This purification system was provided by project partner Mijn Waterfabriek, who obtained a great deal of experience with this type of treatment all along the Netherlands. So it becomes easy to obtain perfectly clean water.

Finally, John Rook about the prospects of the project: ‘We will be gaining experience in applying rainwater for all kinds of purposes. In Bergschenhoek we can potentially collect about 8 million rainwater per year, more than enough to meet the total water needs of our firms.”

Background information about car washing in the Netherlands: In 2022, the Netherlands is having more than 1,800 car washes, using approximately 4 million cubic meters of water per year. If 25% of that volume would be provided using rainwater, the extraction of one million cubic meters of water from the subsoil could be prevented. Which is equivalent to the water consumption of 20,000 households in the Netherlands.