LONGMONT — Tossing cow pies in a public pool after hours seemed like fun for somebody in Cañon City several summers back.
The culprit likely hoped the fecal patties floating like ugly lily pads overnight would shock and disgust pool staff and swimmers.
But the prank backfired and created the worst outbreak of cryptosporidium — “crypto” for short — in recent Colorado history, said Glenn Bodnar, a drinking water expert with years of swimming pool experience at the Colorado Department of Public Health and Environment.
State regulations mandate public pools to filter all their water, which could be tens of thousands of gallons, at least once every six hours.
That process, he said, dissolved the offending fecal flotsam in the Cañon City pool by the time the doors opened. However, the pool water that day was still teeming with crypto, Bodnar said.
According to the federal Centers for Disease Control and Prevention in Atlanta, crypto can live several days in chlorinated pools and sickens exposed swimmers within seven to 10 days.
“It’s almost like watching an alien show or something,” Bodnar said. “You ingest a parasitical cyst like crypto, and it gets into the lower intestine. Then, it breaks out and releases toxins that cause diarrhea.”
To stay as safe as possible from crypto, never drink pool water, he advised.
Animal and human feces — often invisible to the naked eye — usually get into pools through baby diapers and accidents, and they carry other bad news germs such as giardia, E. coli 0157:H7 and shigella.
All can cause diarrhea, vomiting, cramps and other ill effects.
“If any type of fecal material is in the pool, it must be closed for at least an hour,” Bodnar said. “If it’s diarrhea, it’s a 24-hour shutdown.”
The city of Longmont manages five pools, three of them during the summer only.
During that brief, hot, three-month stretch, nearly 100,000 people visit the facilities, according to aquatics director Karen Charles.
Safety-minded staff go above and beyond state regulations by testing the pH and chlorine levels at least five times a day, rather than the required three, she said. To pack the most punch as contaminant killers, both pH and chlorine levels must be in proper balance.
As pH rises, chlorine’s ability to kill germs plummets. So, on the zero to 14 pH scale, a 7.4 pH enables chlorine to be 70 percent effective, Charles said.
Pool pH, Charles said, should fall between 7.2 and 7.8. Less can cripple germ killing. More can unnecessarily irritate a swimmer’s eyes and skin.
Lori Siedelman, an environmental health specialist with Weld County Department of Public Health and Environment, described chlorine as a seek-and-destroy chemical.
It binds to and neutralizes contaminants, she said, such as germs, urine, skin cells, oils or leaves from a nearby tree.
Charles noted that environmental factors such as the size of the pools, the turnover rate of the pool water and the number of swimmers can all threaten the pH/chlorine balance.
“People don’t think about it, but swimming laps, you’re sweating. And even that sweat throws off pool chemistry,” she said.
That explains why pool staff, under the direction of a certified pool operator, test the water frequently.
Earlier this week, Sunset pool lifeguard Luke Diede, 21, toted the black plastic testing kit poolside at about 12:30 p.m.
“It’s not brain science,” Charles said. “But you can’t be colorblind.”
Diede dipped two vials, one at a time, from about a foot below the pool’s surface and away from a jet to get an average water sample.
Then, he dropped two different aspirin-sized pellets in each vial — one to test pH levels and the other to check chlorine concentration in parts per million.
The chlorine began turning hot pink while the pH test looked more and more like watered-down cranberry juice.
After a minute or two, Diede pulled out a black plastic box-like device and slipped one of the vials inside. A window in front of the box shows a section of the vial. Diede then inserted a slide with graduated colors keyed to pH levels.
By comparing the sample to the scale, he can determine the water’s pH.
Diede then repeated the process to determine chlorine levels.
At the beginning and end of every day, pool staff do both these tests in addition to a battery of others to maintain clean water.
Some waterborne germ infections cause gastrointestinal upheaval and dashes to the bathroom.
Others result in swimmer’s ear, hot tub rash and swimmer’s itch.
A germ called Pseudomonas aeruginosa contaminates recreational water and swishes into the ears. Within days, a person may suffer from the uncomfortable symptoms of swimmer’s ear — itching, redness, inflammation and possibly pus drainage from the ear, according to the CDC.
Pseudomonas aeruginosa also can cause dermatitis, known as “hot tub rash,” a bumpy, red rash that may sprout pus-filled blisters.
Direct skin contact with contaminated water causes the infection and usually occurs within a few days of lounging in a poorly maintained hot tub or swimming in a contaminated pool or lake.
Cercarial dermatitis — commonly called swimmer’s itch— represents another pool bugaboo.
An allergic reaction to infection with certain parasites of birds and mammals, the condition can occur within minutes of swimming in contaminated water.
A doctor’s visit is generally not warranted, and those suffering from swimmer’s itch can find relief in cortico-steroid cream, cool compresses, baking soda or oatmeal baths, and anti-itch or calamine lotion, according to the CDC.
Swimmer’s ear and hot tub rash should also clear up without intervention. If they don’t, call the doctor.
Swimmers trust pool staff to keep them as safe as possible. And pools with good pH and chlorine testing programs rarely spread these infections.
But taking more personal responsibility, such as showering before and after swimming, can only help, Siedelman said.
“People don’t understand the purpose of showering before,” she said. “They think, ‘Why take a shower before I’m going to jump in the pool and get wet?’”
But that step alone can wash cells and oils off the person, freeing pool chemicals to attack the really bad stuff.
Showering after may be even more important.
“A lot of bacteria can cause rashes in folds of skin and moist areas of the body,” Bodnar added. “So use soap and water.”
Pam Mellskog can be reached at 303-684-5224, or by e-mail at pmellskog