No matter where you are swimming -- in your backyard or community pool -- you should know the difference between a healthy pool and a risky one.

In the last decade, the number of illnesses resulting from a swim in unclean water has increased, according to the U.S. Centers for Disease Control and Prevention (CDC), with children, pregnant women and those with compromised immune systems at particular risk of developing severe illnesses if infected.

Proper pool treatment and healthy behavior are keys to a safe swim protecting water quality and swimmer health. In fact, when it comes to pool treatment, chlorine remains the first line of defense against germs.

But, how can you tell the difference between a healthy pool and a risky one? Using your sense of sight, touch, smell and sound can help, according to a national partnership formed by the CDC, National Consumers League, Water Quality and Health Council, and the American Chemistry Council.

The partnership offers these "Sense"-able swim tips to help recognize the difference between a healthy pool and a risky one:

* Sight: Look for water that's clean, clear and blue.

* Touch: Check for tiles that feel smooth and clean.

* Smell: Make sure there are no strong odors.

* Sound: Listen for pool cleaning equipment.

"A well-maintained, properly chlorinated swimming pool is essential to preventing illnesses from waterborne bacteria and viruses," said Water Quality Council member and noted Michigan State University microbiologist Dr. Joan Rose. "These pathogens can cause swimmers to experience diarrhea, respiratory illness, ear or nose and skin infections."

Everyone has a role in preventing waterborne illnesses, including swimmers. As such, the CDC recommends healthy swimming behaviors that include: don't swim when ill with diarrhea; don't swallow pool water; take frequent bathroom breaks; and practice good hygiene.