Recreational Water Illness (RWI)Disease Surveillance Epidemiology Program

Recreational Water Illness (RWI)

Though summer is short in Maine, residents and visitors spend time in pools, lakes, rivers, hot tubs, and at beaches. Staying healthy while enjoying summer activities is important. Keeping our recreational water sources clean is also important. Please read below to discover what you can do to stay healthy this summer and help keep others healthy too. Happy Swimming!

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Frequently Asked Questions

water drop What are RWIs?

  • Recreational water illnesses (RWIs) are caused by germs spread by swallowing, breathing in mists or aerosols of, or having contact with contaminated water in swimming pools, hot tubs, water parks, water play areas, interactive fountains, lakes, rivers, or oceans. RWIs can be a wide variety of infections, including stomach, skin, ear, respiratory, eye, neurologic and wound infections. The most commonly reported RWI is diarrhea.

water drop How are RWIs spread?

  • Swallowing water that has been contaminated with germs is the primary way RWIs are spread. Water can be contaminated from stool, sewage spills, animal waste and water runoff during rainfall. Some RWIs are caused by germs that live naturally in the environment. Proper disinfectant levels in pools or hot tubs will kill most germs.

water drop Why Doesn't Chlorine Kill Recreational Water Illness (RWI) Germs?

  • Chlorine does kill germs that cause RWIs but the time that it takes to kill each germ varies. Some germs, like Cryptosporidium (frequently referred to as Crypto) can survive for days in a properly disinfected pool. This makes it very important to keep the germs out of the water.

water drop Who can most likely get ill from RWI?

  • Children, pregnant women, and people with weakened immune systems (people living with AIDS, organ transplants, receiving chemotherapy) can suffer from more severe illness if infected.

water drop How can I prevent RWIs?

  • Don't swim when you have diarrhea
  • Don't swallow the water
  • Wash your hands after using the toilet or changing diapers and shower with soap before swimming
  • Take kids on bathroom breaks or check diapers often
  • Change diapers in a bathroom or a diaper-changing area
  • Wash your child thoroughly (especially the rear end) with soap and water before swimming

water drop Posters, brochures and more

Various posters, brochures, podcasts and other materials are available from the federal CDC at the following websites:

water drop Resources for Health Care Providers

To report a recreational water illness or a related concern please contact the Maine CDC at 1-800-821-5821 or e-mail: More information on reportable diseases