Last summer, workers, tourists and travellers alike were subjected to a pungent pong every time they entered the main station in Zurich - Zurich HB. Now, after a somewhat fresher-smelling winter and spring, the stink has returned once again, with Swiss public transport providers now promising swift action.

Toilet-like smell returns to Zurich Main Station 

The summer of 2022 was likely a strange time for the inhabitants of Canton Zurich - COVID restrictions were gone, people were returning to daily life as they knew it in 2019 and passengers were back to taking Swiss trains on the regular. Unfortunately, for people using what is often touted as the best railway station in Europe, they were greeted with an awful, badly maintained toilet-like smell.

Now, it seems the Eau d’Hauptbahnhof has made an unwanted return in 2023, with people on platforms 31 through 34 and on the Löwenstrasse underground bypass telling 20 Minuten that “it smells like a sewage treatment plant, again.” Onlookers told the newspaper that people were holding sweaters and jackets in front of their noses, with one passerby simply recalling that “it was really bad.”

High-tech Swiss trains to blame for bad smell

So why does Zurich HB stink so badly? Well like last year, modern technology is responsible for the whiff on the tracks. Speaking to 20 Minuten, a Swiss Federal Railways (SBB) spokesperson blamed the smell on the toilets on the new FV-Dosto trains - affectionately known as the “shaker trains” which run services between Swiss cities.

As human refuse is no longer allowed to be dropped onto open track, the Dosto uses a mini sewage treatment plant for each of the 460 toilets on board the 62 trains currently in service. In theory, the bacteria in the plant’s bioreactor will be able to neutralise and treat all the human waste collected, depositing the then clean, odourless water down the drains near the platforms at Zurich HB.

Unfortunately, a combination of what the company described as “weak bacteria”, coupled with the refuse of stressed commuters, means the water dropped onto the tracks is not entirely clean. With passenger numbers reaching record levels and the weather now heating up, the stench is set to return for the next few months.

SBB cannot say how long the odour will last for

"In order to avoid a relapse, SBB has been checking all bioreactors again since April," noted the SBB spokesperson. "Despite these measures, the SBB has found that individual toilet systems are still not working as desired." 

"We are aware that this is uncomfortable for travellers and we apologise for it," the spokesperson noted, promising to do everything the company could to stop the smell. Finally, despite the previous plan stating that the issue would be solved by the end of 2022, SBB concluded that they could not say how long it will take to solve the problem completely.

Thumb image credit: Shutterstock.com / Michael Derrer Fuchs