Rijnstraat 8, The Hague

A clear increase can be seen in the number of projects where wastewater is no longer considered a waste product, but a source of raw materials. The recovery of energy and nutrients is central to this. A great example of one of these projects is the decentralised treatment plant in the Nieuwe Rijkskantoor at Rijnstraat 8 in The Hague.
The new accommodation for about 6,000 civil servants of a number of central government ministries is equipped with a plant that processes wastewater and recovers energy and nutrients from it.

In short, this means that the waste streams present from the office in the building are treated. For example, black water from vacuum toilets, together with organic waste, is collected and processed in a digester. The digestion process releases renewable energy in the form of biogas, which is used to heat the building. The yellow water, from the urinals, is collected separately from the black water and then processed in the struvite reactor. From the collected urine, phosphate is recovered in the form of struvite. This can be directly applied as fertiliser. As waterless urinals and vacuum toilets are used, significant savings are made on drinking water consumption.

Desah designed the plant. This new installation will pay for itself through the savings on water use, treatment charges and waste treatment and energy costs. The ministry building is the largest office where such a sustainable sanitation concept has been applied.