A toilet that keeps water systems clean

Swiss cleantech innovation highlight

Constructing WCs is hardly the sexiest occupation, says Philipp Untersander. That’s as may be, but the toilets produced by the entrepreneur from St. Gallen are a paragon of cleanliness.

CLOsac toilet
It is impossible to remove all traces of medicaments, cosmetics and chemicals from waste water - CLOsac is a solution.

Out of sight, out of mind – this maxim is certainly true in relation to flushing toilets. Fortunately, sewage treatment plants are able to remove most of the contamination from the water that enters the sewers from WCs. However, even the most modern sewage treatment processes have their limits – it is impossible to remove all traces of medicaments, cosmetics and chemicals from waste water. Micropollutants therefore represent a considerable proportion of the contamination in today’s waters.

One source of these persistent pollutants is from hospitals and care homes. X-ray contrast agents, chemotherapy drugs and other medicaments are used frequently in these institutions, and through the patients’ excretions generally reach the sewerage system untreated. From there, some of these traces reach the water systems that form the basis of the drinking water supply.

Airtight and odour-tight encapsulation

Philipp Untersander has got to the root of the problem. With his family firm, CLOsac AG, he has developed an innovative toilet that flushes without water. Human excrement does not reach the sewer system, but faeces and urine are sealed, hygienically and odour-free, in a plastic film from a dispenser in the toilet seat. Packaged in this way, the excrement – depending on the type of contamination – is disposed of in a standard waste incineration plant or properly burnt in a high-temperature furnace.

Several Swiss hospitals have already opted for the dry WC, known as the Rollac 1.0. Because the toilet does not need a water connection, it can also be used on a mobile basis, making it more convenient for use by dialysis patients or those in isolation rooms. Philipp Untersander also believes that the Rollac is the answer to the high requirements placed on the cleaning of industrial waste waters by the water pollution control legislation.

Lighter and cheaper

The mobile dry toilet from the town of Grabs in the Rhine valley near St. Gallen has also received considerable interest from hospitals in Austria and Germany. Following production of the first 50 units, the second generation, the Rollac 2.0, is set to be introduced to the market in 2017. The weight of the toilet, currently only 76 kg, will be reduced even further. The price, based on a use-related lease fee that includes disposal of the excrement, will also be reduced further as production volumes grow.

The basis for the waterless toilet was developed in a project that lasted several years by researchers at the University of Applied Sciences and Arts Northwestern Switzerland in Muttenz (canton of Basel-Landschaft). Established companies initially turned their noses up at the new development. But Philipp Untersander grasped the opportunity and presented the prototypes of the Rollac in 2014. Three years on, he now has his cleantech innovation ready for mass deployment on the market.

© Swiss Cleantech Report 2017 - – interactive mobile app via Play available (Androïd / iOS)


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