Even though the outdoor swimming season is wrapping up, swimmers and families are being encouraged to learn how simple health and safety habits can help prevent pool contamination incidents that can lead to closures.
Sunni Belle, general manager for Recreation Excellence, said the company is using the end of summer as an opportunity to educate the public about how simple health and safety habits can reduce incidents at both outdoor and indoor pools.
“We wanted to give the community some information so that we could get some help from them as well in the fight against contaminations,” Belle said.
The push comes after Henderson Lake Pool experienced an increase in contamination incidents this summer, with 25 events resulting in 49.25 hours of lost programming time in 2026 up from 11 events resulting in 6.25 hours of lost programming time in 2025. Belle said Henderson’s large size and high number of swimmers can contribute to the problem.
She said the outdoor facility also allows food, and families often spend several hours there in the hot sun.
“They have a great time but kids have so much fun and families are having so much fun that sometimes bathroom breaks get missed or they won’t wait an appropriate amount of time after eating and then you could have a vomit in the pool, things like that.”
She said she encourages everyone to swim before they eat.
“Enjoy your time at the pool, be here for a few hours and it doesn’t matter whether it’s the outdoor pool or the indoor pool and then have a have a meal or a snack when you go home from your swimming experience.”
Bathroom breaks are also important, particularly for children who may not want to leave the water while they are having fun. Swimmers should also stay out of the pool if they are experiencing gastrointestinal symptoms.
For babies and children who are not toilet-trained, Belle recommends following a three-layer approach: a swim diaper, plastic pants and a bathing suit.
If people are doing those types of things then we can prevent contaminations from happening in the pool.
When an incident does happen, maintenance manager and safety co-ordinator with Recreation Excellence Brad Pack said staff have a set procedure to follow before swimmers can return to the water. This includes first clearing the pool and remove the contaminant before beginning the treatment process. The required closure time varies according to the type of contamination and the chlorine level in the pool.
For formed stool or vomit, Alberta Health Services guidance calls for 50 minutes of treatment at one part per million of chlorine, 25 minutes at two parts per million and about 17 minutes at three parts per million.
More serious contamination, such as diarrhea, can require a significantly longer closure.
Pack said staff use Alberta Health Services’ CT-value requirements to determine how long the water must be treated. The calculation combines the chlorine concentration with the length of time it remains in the water.
For diarrhea-contaminated water, the required CT value is 15,300. At 10 parts per million of chlorine, that works out to 25.5 hours of treatment.
For outdoor pools using cyanuric acid as a stabilizer, Alberta Health Services guidance specifies different treatment times depending on the chlorine concentration and requires the cyanuric acid concentration to be reduced to 15 parts per million or less.
Increasing chlorine levels is not necessarily a practical way to reduce the closure time.
“We also have to consider that somebody could say, well, why can’t you just put 40 parts per million in the pool and shorten the time? When you get that concentration going up that high, now you have to worry about how it affects all of your back end stuff,” Pack said. “We have to stay within parameters.”
He added the first priority is keeping swimmers safe, followed by getting the pool open again so people can enjoy the facility.
“An empty pool is no fun.”
Belle said contamination incidents can happen at indoor pools as well, even though Henderson saw an increase this summer.
The goal of the education campaign is to carry the prevention message into the fall and winter, when people move toward indoor facilities.
“We’ll just keep campaigning to bring those messages out and hopefully we’ll see some improvements,” Belle said.
She emphasized that the message is not intended to shame parents when accidents happen.
“No parent wants to be the parent that has somebody that has had an accident in the pool,” Belle said. “I think the more we can get a message out to the community the better so that they understand the steps that they need to take to help prevent accidents from happening in the pool.”
She added the goal is to make families feel supported and give them the information they need to reduce the likelihood of an incident.
Belle said preventing contamination requires cooperation between pool operators and swimmers. Reducing contamination incidents also means fewer closures and disruptions for pool users, she said.
