Dry worm compost toilets being tested in Brussels parks: “once the worms are added, it works on its own for 5 years”

Treadmill

Cube of boards and classic “non-gendered” signage, the look of these new type of toilets does not revolutionize urban design. Innovation is located under its board and behind its partitions. “They separate urine and feces into two streams,” explains Noura Rkiouak. “The urine flows into a tank and the solids fall onto a conveyor belt which carries them out the back.” This is where the earthworms are used to transform all this little meal into compost.

The technician already has some positive points from the experience. “These toilets are autonomous: no need to connect them to the sanitation network, water or electricity. No need for sawdust either.” How is the “hunt” shot? “The evacuation mat is mechanical: it is activated with a pedal that you press 5 times with your foot.” Another advantage: a very extended emptying rate. “Once or twice a year for urine, and once every 5 years for vermicompost,” assures Noura Rkiouak. “Once the earthworms are at work, it works by itself! Even if I asked for an emptying within two years for the test phase, to have an idea of ​​the accumulation”.

Odors?

What about smells? “In the cabin, you smell almost nothing thanks to the forced ventilation. This is less the case in the technical room which houses the earthworms. The smell there is really not pleasant. However, it is there too that we store toilet paper: we may have to move this technical room.” Another negative aspect: “a certain fragility of the equipment, in particular the handle or the occupancy indicators”. Anecdote: a user already found himself stuck when the toilets automatically closed at the end of the day. “We close them at night, given the problems it can cause in Brussels,” agrees Noura Rkiouak. “One time, someone was there during this closure.” Fortunately, the park guards rescued this person from his predicament. Here too, automation will need to be refined.

The unthought-out equation remains to be resolved: what to do with composted feces? In fact, Belgian law does not comment on the channels for reusing human urine and feces. “We are waiting,” recognizes the manager of Brussels Environment. “The only option today I think is use in the forest.” In Viroinval, the compost will be used for the Commune’s plantations.

These toilets are in the testing phase for two years. They were designed by the French company Sanisphere and installed by the Belgian partner Niezen. “It is the latter company which ensures its maintenance during the test phase. We carry out the control and monitoring”, specifies Noura Rkiouak. If the test is conclusive, other green spaces could be equipped with it. Budget for the two toilets according to Brussels Environment: €112,000 for supply and placement, €40,000 for maintenance (technical and cleaning) for 2 years.