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Where are Recreational Water Illnesses (RWIs) Found?

RWIs are caused by germs spread through contaminated water in swimming pools, water parks, water play areas, hot tubs, decorative water fountains, oceans, lakes, and rivers.

Swimming Pools, Water Parks, Water Play Areas

Kids playing in a water play area.

The most common RWI is diarrhea. Swallowing water that has been contaminated with feces containing germs can cause diarrheal illness.

Swimmers share the water—and the germs in it—with every person who enters the pool. On average, people have about 0.14 grams of feces on their bottoms which, when rinsed off, can contaminate recreational water. In addition, when someone is ill with diarrhea, their stool can contain millions of germs. This means that just one person with diarrhea can easily contaminate the water in a large pool or water park. People may not realize that although there is no standing water in interactive fountains/water play areas, the spray water will rinse any contaminants (for example, diarrhea, vomit, and dirt) down into the water holding area and be sprayed again. In other words, the water is recycled through the system.

Swallowing even a small amount of recreational water that has been contaminated with feces containing germs can make you sick.

To ensure that most germs are killed, check chlorine or other disinfectant levels and pH regularly as part of good pool operation [PDF - 86 kb].

For more information, please see the Pools and Hot Tubs section and the Water Play Areas and Interactive Fountains page.

Hot Tubs

An older couple relaxing in a hot tub

Skin infections like "hot tub rash" are a common RWI spread through hot tubs and spas. Respiratory illnesses are also associated with the use of improperly maintained hot tubs.

The high water temperatures in most hot tubs make it hard to maintain the disinfectant levels needed to kill germs. That’s why it’s important to check disinfectant levels [PDF - 98 kb] in hot tubs even more regularly than in swimming pools.

The germs that cause "hot tub rash" can also be spread in pools that do not have proper disinfectant levels and in natural bodies of water such as oceans, lakes, or rivers.

Decorative Water Fountains

Kids playing in a decorative water fountain.

Not all decorative fountains are chlorinated or filtered. Therefore, when people, especially diaper-aged children, play in the water, they can contaminate the water with fecal matter. Swallowing this contaminated water can then cause diarrheal illness.

Oceans, Lakes, and Rivers

Old man with a surfboard.

Oceans, lakes, and rivers can be contaminated with germs from sewage spills, animal waste, water runoff following rainfall, fecal incidents, and germs rinsed off the bottoms of swimmers. It is important to avoid swallowing the water because natural recreational water is not disinfected. Avoid swimming after rainfalls or in areas identified as unsafe by health departments. Contact your state or local health department for water testing results in your area or go to EPA's beach site.

For more information, please see the Oceans, Lakes, and Rivers page.

For more information on recreational water illnesses, including brochures, posters, and educational materials, please see Healthy Swimming's Health Promotion Materials page.

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