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.