Focused on cooling down and keeping the kids occupied for a few hours, many don't think twice about skipping the showers and just jumping in. But federal health officials say they should - the spread of recreational water illnesses is on the rise nationally.

A Salt Lake Tribune review of Salt Lake County pool water inspection records from the past year shows the best water quality at public pools, where just under one-quarter of all facilities had violations.

The worst: hotels and motels, where 37 percent had violations in the past year. Whirlpools were especially problematic. Private community pools, such as those at apartment complexes and health clubs, followed with a 32 percent violation rate.

Last year, the Salt Lake Valley Health Department closed 98 pools, about 10 percent, due to a public health risk.

Even so, water quality supervisor Teresa Gray said swimmers should remember the monthly samples taken by her inspectors represent a snapshot in time.

Pool water can change quickly.

"The sun can burn off disinfectant, or too many people can be in the swimming pool at the same time," she said.

Contamination sources: Most recreational water illnesses enter water through fecal matter, and spread through contact or swallowing contaminated water.

Exposure to the five most common bugs - cryptosporidium, E-coli, giardia, shigella and Hepatitis A - usually results in diarrhea, according to the Centers for Disease Control and Prevention (CDC). But it can also mean skin rashes and ear or respiratory infections.

The CDC says from 1984 to 2002 it saw an increase in reported diarrheal outbreaks, resulting in about 19,000 water-related illnesses over that time period. Officials attribute the rise to increased recreational water usage and improved detection.

Utah tracks the number of cases of the five most common causes of water-related illnesses, but determining how they were transmitted is difficult, officials say. Most of the cases stem from contaminated food or human contact, such as sexual contact.

"The data do not very much represent water-related illnesses," said Ilene Risk, epidemiology bureau manager with the Salt Lake Valley Health Department, which sends its statistics to the state. "We have not had any outbreaks at swimming pools in recent years."

Everybody out! On a blisteringly hot day earlier this month, Juneal Wilding, of Bluffdale, joined other mothers and children leaving the South Jordan Recreation Center en masse after the pool was closed.

"Someone had an accident, and they told us it would take an hour to clean up," said Wilding. "It's disgusting."

The ill-fated outing was the first time Wilding and her twin 6-year-old boys visited the recreation center, which tied the Holladay Lions Fitness and Recreation Center for the most violations for a public pool between July 2005 through June 2006.

Tod Bean, recreation facilities director at South Jordan, said most violations resulted from the kids' wading pool.

"We've really stepped things up there," he said. "We shock it twice a week, drain it once a month and test the water every two hours."

Wilding said she hadn't thought much about pool water standards before that day.

"I'll probably ask about violations in the future," she said.

Parents at the Holladay pool also were unaware of unsatisfactory samples. Poolside, Lindsay Nolin said she takes her children, 7 and 10, to the pool more in the fall and winter than summer. The center received violations for its whirlpool and pool in September and October.

"There's tons of kids here," Nolin said, looking out at the water slide and other pool toys. "My concern is if the facility is doing its part on testing. My first thought today was the water looks murky. I'm glad I'm not going swimming."

Nearby, Anne Hickey watched her two visiting grandchildren play. A retired nurse, Hickey had no worries.

"The lifeguards have been doing hourly checks," she said. "I've been in every part of this pool and it looks clean."

Tracy Gines, director of the facility, said the whirlpool was fixed after the health department found discrepancies. It is emptied once a week and replenished with chemicals, she said.

"Last year we had problems with the whirlpool because it wasn't draining properly, but we fixed it right away," Gines said.

Dave Young, program manager for the Marv Jenson Fitness Center in South Jordan, said his lifeguards test the water every two hours to ensure safety. But sometimes problems occur. The center's kiddie pool failed a test last July.

"Hot tubs and kiddie pools are difficult to manage and high maintenance," Young said. "Such small bodies of water can get out of balance quickly. But we rarely have problems."

Warm-water worries: In shallow baby pools and hot whirlpools, warm temperatures and small spaces create a perfect environment for germs to multiply.

That means more problems at hotels, apartments, condos and gyms, which don't have staff check the water as frequently. Of the 34 hotels cited by the county in the past year, three-quarters failed the whirlpool water quality test.

One of those hotels was downtown Salt Lake City's Little America Hotel with three violations. The most recent was in April. Spokeswoman Shannon Short said quality is up to standard now.

"We are very sensitive to the safety of our guests, which is why we have a pool attendant check the water every hour," she said.

Gray has been in charge of the county's pool program for three years and inspected pools before then.

"We as a health department try very hard to make sure people are safe," Gray said. "The likelihood of getting ill in these facilities is very low. I take my daughter and my son to the swimming pool, so that tells you it's not risky."

Fountains aren't required to meet pool standards.