Water, Water, Everywhere, But Is It Safe to Swim?

girl swimming It is a favorite summertime activity for all ages. In fact, swimming or relaxing in recreational water, such as swimming pools, water parks, hot tubs, lakes, rivers, or the ocean is one of the most popular activities in the country. Despite safety measures put into place, swimmers can still become affected by recreational water illnesses.

What Causes Recreational Water Illnesses?

In swimming pools, parasites, bacteria, excessive chlorine, and indoor air irritants are the most common causes of recreational water illnesses. Germs enter the water primarily through fecal contamination. Exposure to these contaminants usually results in diarrhea. However, contaminated water may also cause skin rashes, and infections such as swimmer's ear, swimmwer's itch, or respiratory infections.

And while it is true that chlorine does kill these germs, poor maintenance of chlorine levels and filtering systems may impact the effectiveness of chlorination. In addition, chlorine takes time to work, even in the best-maintained swimming facilities. Some parasites are highly resistant to chlorine and may continue to live for several days after a pool has been disinfected.

In lakes, rivers, and oceans, pollution by raw sewage is the largest culprit for water contamination with disease-causing organisms, such as bacteria, viruses, protozoa, and worms. And of course, open water is not chlorinated. This means that you should check with your local public health department or pollution control authorities regarding water quality at your favorite beach before you go.

Swimming Pools, Water Parks, and Hot Tubs

In addition to fecal contamination, swimming pools, hot tubs, and water parks may also be contaminated by vomit or blood in the water. The Centers for Disease Control and Prevention (CDC) publishes guidelines for the maintenance and care of these facilities and recommends procedures to deal with any of the above mentioned types of contamination.

If your favorite spot to relax happens to be a swimming pool, water park, or hot tub, check with the pool’s management and staff to make sure they are aware of these recommendations and have a clear plan for responding to any type of water contamination.

A Day at the Beach

If your favorite water spot is a public beach, here are some questions the EPA suggests you ask your local beach-monitoring official so you can stay safe:

  • Which beaches do you monitor and how often?
  • Where can I see the test results and who can explain them to me?
  • What are the primary sources of pollution that affect this beach?

If your favorite beach is not monitored regularly, here are some things you can do to protect yourself and your family:

  • Don't swim after a heavy rainstorm.
  • Avoid swimming near storm drains when you are at the beach.
  • If your beach is a no-discharge zone for vessel sewage, investigate whether pump-out facilities are available for boats.
  • Be aware of trash and signs of pollution, such as oily water.
  • If you think your local beach is contaminated, contact health or environmental protection officials.
  • Work with authorities to create a beach monitoring program.

The Six Steps for Healthy Swimming

The CDC has published steps for healthy swimming to help you protect yourself and others against recreational water illnesses. Following these six recommendations will go a long way in ensuring everyone has fun in the water this summer!

  1. Do not swim, or allow your child to swim, if either of you has diarrhea. Contrary to popular belief, diapers—even those designed for swimming—do not prevent fecal matter from leaking into the water. Allowing your kids to swim with diarrhea, or doing so yourself, may easily spread germs that could make you, your children, or others sick.
  2. Do not drink the water, and if possible, try to avoid getting it in your mouth. Children should be instructed that this water is not for drinking.
  3. Bathe with soap before swimming and wash your hands after using the toilet or after changing a baby’s diaper.
  4. Take your children to the bathroom often. “Mommy, I have to…” may come too late to prevent an accident.
  5. Change your children’s diapers in the bathroom or in a designated changing area, not by the side of the pool.
  6. Bathe your children thoroughly before they get in the water. The cleaner your children, the cleaner the water. Rinse after getting out as well.

Centers for Disease Control and Prevention

Environmental Protection Agency


Health Canada

Public Health Agency of Canada


Before you go to the beach. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/healthywater/pdf/swimming/resources/epa-before-you-go-to-beach-brochure.pdf. Accessed February 24, 2016.

Healthy swimming/recreational water. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/healthyswimming. Updated Updated May 14, 2014. Accessed February 24, 2016.

Hyperchlorination to kill cryptosporidium. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/healthywater/pdf/swimming/pools/hyperchlorination-to-kill-cryptosporidium.pdf. Accessed February 24, 2016.

LEARN: Human health at the beach. Environmental Protection Agency website. Available at: http://www.epa.gov/beaches/learn-human-health-beach. Updated February 22, 2016. Accessed February 24, 2016.

Steps of healthy swimming: protection against recreational water illnesses (RWIs). Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/healthywater/swimming/protection/steps-healthy-swimming.html. Updated February 24, 2015. Accessed February 24, 2016.

Last reviewed February 2016 by Michael Woods, MD  Last Updated: 2/24/2016