Salt Lake hasn't had a RWI outbreak for several years, but it takes hard work and some luck, says Gray. Last year, health department pool inspectors temporarily closed 98 pools (about 10 percent) due to a public health risk. More cases involve smaller pools at condos than the larger public pools, she said.

It's not easy to keep that much water clean, says Lyse Durrant, aquatics manager at the Cottonwood Heights pool. They check the water every hour, using a test kit that's dipped in the water and must be read immediately, before the chlorine bleaches out the color that indicates the results.

If someone has an accident in the pool, the area is cleared immediately and the water sanitized. It has to test clean before it's reopened.

Durrant says the best thing is to let a lifeguard know so it can be dealt with immediately. "No one's in trouble," but it's important it's cleaned up so others don't become sick, she said.

---

E-mail: lois@desnews.com