Think twice before you jump in. A recent government report reveals that every year there are up to 20 stomach bug outbreaks blamed on pools -- and they're on the rise.
Both public and backyard pools are supposed to be maintained with certain chemicals to keep them clean, but pools can contain bacteria like e. coli, cryptosporidium and shigella, which can cause dangerous intestinal issues plus pseudomonas, which are the culprit behind swimmers ear.
"The thing that usually lurks is bacteria related to human waste," said Spencer Hampy, president of the Oasis Indoor Environmental, Inc., and a certified microbial consultant, who spends his days investigating homes and pools for microbes.
"GMA" teamed up with Hampy and went undercover to check the cleanliness of three adult pools and two kiddie pools.
After careful instruction, our intern gathered water samples: first, a large bottle to send to a lab to test for bacteria indicators, then a smaller one, which we rushed outside to Hampy. He immediately tested for pH and chlorine levels to see if the pools were being sanitized, and for something called ORP to see if the sanitizers were doing their job.
We "want to make sure it's not just chlorine in the pool, but active chlorine," Hampy said.
Pool No. 1
Our first stop was an indoor facility we will call pool No. 1. We arrived early in the day when there were just a few swimmers in the pool. Hampy's initial tests looked good.
"The sanitizers are doing their job," he said. "Based on this information, I don't expect to find any bacteria."
Hampy was right. According to the follow-up lab test, there were no indicators of bacteria. Pool No. 1 is clean and safe for swimmers.
Pool No. 2
When we arrived at the second facility, it was the end of a hot day. First, we tested the kiddie pool because they're notorious for being germy. We found it was actually over-chlorinated. Too much chlorine can be a skin and breathing irritant.
The levels in the main pool were fine. And, sure enough, our follow-up lab tests showed both pools were free of bacteria indicators. Facility number two was clean.
"It goes to show that a well-maintained pool can stand the whole day and the harshest conditions and stay healthy," Hampy said.
CLICK HERE for pool safety tips for your family
Pool No. 3
Pool number three is another story. We arrived early in the afternoon and found a kiddie pool that shared water with a main pool. Our on-the-spot tests revealed that the chlorine levels in both pools were about half of what they should be.
Hampy said that's "an indicator that the sanitizers aren't really able to do their job."
Right again. Our detailed follow-up tests found indicators of harmful bacteria in both pools -- 445 cells per liter of water in the adult pool and 2,351 in the kiddie pool -- when there shouldn't be any at all. And remember, these levels indicate human waste contamination.
"It's alarming that a public pool, where you're supposed to keep these things maintained diligently, was allowed to get its levels so low that that much bacteria was starting to grow," Hampy said.
The bottom line: pool number three is dirty, at such a level that it's unhealthy for swimmers. So would our microbial consultant swim in this pool?
"There is no chance at all," Hampy said.
So, what can you do?
If you can't see to the bottom of the pool, it's probably not clean. Stay out of it.
To check further, try chlorine or pH test strips, which cost $10 to $15. You just dip one in and it changes color to tell you if the pool has the right pH and chlorine levels.
On the other hand, if the pool has a strong chemical odor, it may have too much chlorine, which is an irritant.
Do not swallow pool water. It can even make healthy people sick.
And finally, do your part by not using a pool if you're sick or have an open wound and take kids on frequent bathroom breaks.
As for the persistent rumor that some pools put a chemical in the water that will expose people who pee in the water by turning their urine bright red, it's an urban myth. There is no such chemical. The urine of healthy people is typically sterile, so it's not nearly as much of a concern. Not that I'm recommending peeing in the pool!
Nearly 300 children under the age of five drown in residential and public pools each year, according to the Consumer Product Safety Commission's website, Poolsafety.gov. All swimmers should be aware of the potential for drowning.
The CPSC has put together tips to keep your family safe in and around the pool this summer.
There are simple steps that pool owners can take to make your pool a safer space for kids:
Children must be supervised at all times around a pool.
Install four-sided fencing around pools. If your house serves as the fourth side of a fence around a pool, install a pool or door alarm.
Get training in CPR and water rescue skills.
Have life-saving equipment such as life rings or floats nearby.
Make sure pools have safety drain covers.
For pool safety tips, information on swimming lessons and more, visit Poolsafety.gov.