Peeing In The Pool: The Facts

The Pool Water Treatment Advisory Group sets the record straight on peeing in the swimming pool.
The Pool Water Treatment Advisory Group sets the record straight on peeing in the swimming pool.

‘Is it true that if you pee in a pool on the continent the water turns purple around you?’ That was just one of the questions asked of PWTAG on the radio last month. PWTAG chair Janice Calvert, getting towards the end of her dozen interviews on national and local radio that morning, was able to nail that particular urban myth. But the question, and the publicity around the subject, reflects both how important healthy swimming is for the public, and how sketchy is public understanding of pool science. The story broke in the newspapers at the beginning of March, with headlines such as ‘Goggles please! Swimming pools can contain more than 60 litres of urine — putting users at risk of serious illness.’

IN THE NEWS : The story came from a press release in the American Chemical Society’s Journal, Environmental Science & Technology. Toxicologists from Alberta University had measured concentrations of an artificial sweetener in 31 pools in two Canadian cities. As it is all excreted, and is stable, they were able to say that all the pools had been peed in and that a small pool (400,000 litres) might have 30 litres of urine in it and a large one about twice that. The concentration of urine in hot tubs was up to three times that concentration. The researchers seemed more excited about their new analysis methodology; but not the media. Remembering the fuss in 2012 when Olympic swimmers more or less said that peeing in the pool was a necessary part of their training, and drawing on research that suggests one in six bathers do it, the UK’s radio stations wanted the lowdown.

NO HEALTH RISK : It is gratifying that PWTAG is increasingly seen as the authority on this sort of thing, and it was relatively easy to give the facts;

1. Urine itself presents no health risk.

2. Its disinfection byproducts, some of them admittedly unpleasant, are sorted in a well run pool.

3. Pools should be adding 30 litres of fresh water for every bather (that would have disposed of the sweetener).

4. Nevertheless, the more people pee in the pool, the more disinfectant has to be used and the more risk there is that the pool might smell.

5. So don’t pee in the pool; do it beforehand – and shower as well, as that helps too. We don’t mind having to repeat the message endlessly; it is part of what PWTAG is for.

But pools can and should help reinforce the message. There is of course relevant material on our recently redesigned website,