Many people still do not have access to sanitary facilities. But where toilets are standard, there is a problem: water consumption.
Once rinsed and around 10 liters of drinking water disappear through the drain towards the sewage treatment plant Photo: Jonathan Browning/plainpicture
BERLIN taz | Even the current Spanish king got one in 2004, when Felipe, then a prince, married his Letizia. Perhaps it was a white porcelain pot with an elegantly curved, gilded supporting rim and floral pattern; the handle a stylized snake with green scales. It is directly below the photo of the couple. And is one of the most beautiful chamber pots in the Jose del Arco Ortiz collection of over 1,000 pieces in Ciudad Rodrigo, Spain.
Chamber pots have been around since ancient times and were widespread in the Middle Ages. For good reason: there were no toilets at all, or at most outside of the house. But that’s not the only reason – urine in particular was collected as a valuable resource, for tanneries or for dyeing.
Still, no one wants to go back to that time. But chamber pots didn’t have two problems that today’s plumbing systems have: They waste drinking water. On average, each person flushes away 40 liters of the best drinking water every day. And with the human legacy, resources such as phosphorus in urine or feces are largely lost.
Flush toilets are an “essential building block for the achieved hygiene standard,” says Christian Wilhelm, specialist at the German Association for Water Management, Wastewater and Waste (DWA). “Against the background of climate change“, at least locally strained water resources and, above all, the need for resource recovery and use, we have to make greater use of other solutions.” He is an expert in such solutions: innovative sanitary systems, or NASS for short.
Water saving technology
The best example of this is the new Jenfelder Au residential block in Hamburg, which is so far unique in Europe. Two systems were installed in over 800 apartments instead of one: the toilet water, known as black water, is drained away through water-saving negative pressure toilets. The vacuum toilets only need one liter of water instead of up to nine. All other water – so-called gray water – goes through the second pipe and is partly used for irrigation. Biogas is produced from the faeces for the plant. Operator Hamburg Wasser constantly receives curious visitors who want to see the project.
However, the Jenfelder Au is a lonely beacon for the spread of NASS; there is only a smaller variant in Lübeck. That could change: “So far there has been a lack of pressure to act. But it increases with them Drought summers in recent years.
A lot of ideas are being developed now – but they are still not being implemented very often,” says Wilhelm. They are also expensive and there is hardly any funding. Technically, all of this is possible, says Wilhelm, even in old buildings if they are completely renovated. Obstacles are regulations in planning and construction: “They have to be adapted.”
Wilhelm sits on behalf of the DWA in a newly founded alliance of urban planners, architects and scientists called “Water-Conscious City” who want to advance the idea. “We in the association realized: If we want to change something, then we have to work with others. But we also have to think about mobility – who would support the loss of parking spaces for an infiltration system?”
Ideas for the sewage treatment plant
But it doesn’t have to be the installation of new systems in buildings – there is also innovation potential in sewage treatment plants. In Braunschweig, the specially designed sewage treatment plant does not send the treated wastewater into the water, as usual – but into the fields of farmers who grow energy crops.
During the 2022 drought, the corn fields there were lush green. There could be more: In Germany, energy crops are grown on over 2 million hectares; they do not need to be supplied with ground and surface water. In the region around Murcia, Spain, wastewater is also used to irrigate food (which is then exported to Germany).
There have also long been solutions for recovering the nutrients contained in faeces and urine: Separation toilets, which primarily separate urine with phosphorus, or waterless urinals. On the Swedish island of Gotland, they want to use these urinals to collect 70,000 liters of urine in three years, especially during the tourist season, and use the phosphorus obtained from them to fertilize barley. For beer.
We will have to think more about such experiments in the future. The EU sewage sludge regulation from 2017 stipulates that at least the phosphorus from the sewage sludge must be recovered in larger municipalities by 2029. A difficult task in which Hamburg is once again leading the way with the first large-scale plant for the recovery of phosphorus from sewage sludge ash.
Does King Felipe think of something like this when he pulls his chamber pot out from under the bed? The pot probably isn’t there. But Felipe and Letizia thanked Ortiz very politely. The gift is “a token of appreciation that will be remembered with affection,” says the document that hangs on the wall in the Chamber Pot Museum.
