How Gross Are Public Swimming Pools?

Are you sure you want to know?

Chris Zappa
3 min readJul 25, 2021


Summer is in full swing, and North America is seeing one of the hottest — if not the hottest — seasons on record. But before you grab your pool float and sunscreen and head out to your local public swimming pool, you may want to read on to find out what lurks beneath those waters.

Does the phrase “Petri dish” mean anything to you?

While it shouldn’t take a scientific study to prove that public pools are essentially giant Petri dishes, many studies have confirmed just that. Some see a swimming pool; others, upon careful inspection, see these watering holes for what they truly are — cesspools.

Not only do most public pool areas lack appropriate safety equipment — the least item of concern here — most also lack suitable sanitization measures. In recent years, a dramatic uptick in illnesses and diseases in pool-goers can be directly attributed to contaminated pool water. More often than not, studies have found improper pH levels to be more the rule than the exception.

Don’t believe your eyes or your nose!

Just because a pool may look clean and you can detect the distinctive smell of chlorine doesn’t actually reflect cleanliness or that the water has properly balanced pH levels.

As a matter of fact, that smell that you think is chlorine? It’s not. It’s actually a substance called chloramines and results from mixing chlorine and bacteria (i.e., feces, urine, and sweat.)

A survey conducted in 2012 by the Water Quality & Health Council found that one in five adults urinates in public pools. But that’s an old survey, and those are only the people who admitted to doing it. The real number is no doubt much higher. As for kids, how many kids pee in the pool? You can safely bet it’s more than 1 in 5. I’d guess more like 4 in 5.

The same study found that most people (70% according to their findings) do not shower before going into the pool, adding to the overabundance of germs bodies will shed in the water. Along with sweat, skin cells and body hair are also regularly sloughed off.



Chris Zappa

Graphic designer. Music junkie. I run Zappagram, the mother of all music newsletters. https://bio.site/chriszappa