"Parents have to be very observant. They need to change their children's diapers away from the side of the pool and also check their children's bottoms after they go swimming," Schaffner said.
Despite the inspection findings, experts stressed that there's no need for alarm, and no need to keep away from public pools.
"Swimming is a great physical activity, but people just need to think a little more and take more active roles in making sure it's healthy, too," Hlavsa said.
"While they found that about 12 percent of pools didn't pass inspection, there were still about 88 percent that did meet the criteria, and that's significant," Schaffner said.