Ever drink the pool water by accident and think “Eh, it’s not that big of a deal.” Well a new study says it might be a bigger deal than you think, according to USA Today.

The study found signs of feces in more than fifty percent of pools sampled in Atlanta, Georgia last summer. Before you get excited because you don’t live in the capital of Georgia, Michele Hivasa, a researcher who focuses on healthy swimming at the Centers for Disease Control and Prevention, has some news.

“I think if we had done this study anywhere in the United States, we would have found the same thing," she said. Hivasa adds that pool operators are not entirely at fault. “This is really about swimming hygiene,” she explained.

In summary, there are traces of defecation in the water because people are either not showering or having accidents in the pool. Public health officials are concerned because this can cause swimmers to become sick.

The study examined 161 pools—37 municipal pools, 89 club membership facilities, 35 small water parks. According to Hivasa the water parks included any place with at least a spray feature.

According to the report, DNA from E. coli bacteria—normally found in the gut and feces—were discovered in 58% of the of samples. These are called “fecal indicators,” or proof that fecal matter rinsed off someone’s rear end or was produced from someone’s rear end. The test did not say whether the bacteria were dead or alive.

Municipal pools showed the most readings.

Fortunately there were no strains of O157.H7, the strain of E. coli bacteria which can be dangerous and cause illness. Also, signs of cryptosporidium and giardia, germs that spread through feces and cause diarrhea were only discovered in just one and then two samples.

Here are some tips for keeping the pools clean:

-Don’t swim if you have diarrhea

-Take a shower with soap before you swim

-If you are supervising children take them to the bathroom every hour

-Don’t change diapers next to the pool

-Don’t swallow the water.

While chlorine and pH levels are important, Hivasa says swimmers “have to take some responsibility.”

The report was published in the CDC's Morbidity and Mortality Weekly Report.