Is that water clean? Here are the best beaches getting tested around Calgary

Sikome Lake has a kilometre of sandy beach that's open to the public and sits within the city limits of Calgary. But when the lake comes up in local social media chatter, it's often with a serious question: Is it safe to swim?

Well, a beach on the prairies is rare enough.So wewent on a hunt for answers.

CBC Calgary drove to Fish Creek Provincial Park and got a tour of the Sikome Lake water treatment centre. Then we requested provincial water quality testing data for all the recreational swimming holes in and around Calgary.

Finally, we checked in with an independent waterquality expert to see how she finds the best places to swim.

Going 'back of house' at Sikome Lake

On a hot day in July, we met up with Michael Roycroft,the local regional director for Parks Alberta, at the north gate of the park and stopped to look out over the water. The lake itself is about the size of four soccer fields. It's roughly a kilometre around, and is eight feet deep at the centre with a sandy bottom.

It gets 85,000 visitors every season, and up to 5,000 a day on a weekend when the weather is hot.

We walked east around the lake, past the playground, grassy picnic areasand volleyball courts, to a old-lookingbuildingwith faded wooden siding. But looks are deceiving here. A couple years ago, Parks Alberta spent $4 million on upgrades, with the bulk of that going to equipment inside this water treatment centre.

Since then, Roycroft says, the lake is tested daily and has never been shut down for water quality issues.

So how is the watercleaned?

"The process of making sure water is clean actually starts before the water is even added to the lake," said Roycroft.

Staff scrape out any plants or other junk that collects on the sand over the winter. Then they fill the lake from three wells connected to an underground aquifer.

"In terms of treatment (during the season),water is pulled in through nine skimming locations around the lake," he said."Asmall amount of coagulant is added to (make) contaminants clump together and allow the filters to pull that contamination out.Then once the water is filtered, the water is transferred to a clear water tank underneath the facility.

"Chlorine is added and the water sits there for a certain amount of time to allow the chlorine to do its job. Then that water is discharged back into the lake."

"The treatment process that we go through issimilar to what an outdoor pool or even indoor pool would do.The chlorination levels are constantly monitoredand adjusted," he said.

Roycroft says they test for bacteria daily at various spots around the lake and do spot treatment with chlorine if necessary. They also send weekly tests to Alberta Health Services. The treatment facility is running 24/7 and it's large enough so that all of the water passes through it every seven days.

WATCH | This water treatment plant keeps Calgary's public lake swimmable:

A look at the water treatment plant that keeps Calgary's public lake swimmable

16 days ago

Duration 1:53

Sikome Lake is a unique swimming spot inside Calgary's Fish Creek Provincial Park: it's shallow, warm and sandy-bottomed, making it a great place for a beach day. But some have asked if the lake is safe to swim in. Alberta Parks regional director Michael Roycroft took CBC News on a tour to explain how the man-made lake is maintained.

"Once we close down in September, the lake is allowed to sit for a number of weeks to allow the chlorine to dissipate and evaporate until we have zero chlorine in the water. Then, after another 14-day resting,we're allowed to ...discharge that water into thefen just next next to the facility here and intothe BowRiver."

Faraz Siddiquiand Syeda Ahmad were at the lake with their daughters the day CBC Calgary visited. Siddiqui was pleasantly surprised by the water quality.

"I was expecting it to be a little salty, but it's not. It tastes like fresh water," he said. "The kids enjoyed it."

Map of monitored beaches in the Calgary area

In Alberta, water quality testing for a recreational swimming hole is voluntary and little information is shared publicly unless there's a problem.

CBC Calgary talked with Dr. Franco Rizzuti, the AHS medical officer of health for the Calgary zone. He said staff have been talking internally about how to make more of this information public. But for now, when we asked,they simply shared the data collected so far this season and explained it.

Basically, if the lake is listed on the map below, that means whoever is responsible for the lake has signed up with Alberta Health Services for a monitoring program. The lake caretakers will collect water samples, typically once a week and from several locations in the lake.

If the reading exceeds a minimum threshold, the lake managers are required to test again to confirm that the bacteria aren't coming from human or "ruminant" fecal matter, such as from cows or sheep.

If the bacteria are from humans or ruminants, and if the problem continues,warnings will be posted onlineand at the site.

AHS has results for 20 locations in the Calgary area. None of the water bodies being tested for fecal bacteria have had warnings issued yet this year.

But there are quite a few lakes that are exceeding that first, minimum threshold. They still fall into Alberta's safe category, but it's an indication these lakes are less clean than others.

For example, at Chestermere Lake, bacteria tests exceeded that minimum threshold eight testing days out of 10. Tests were conducted at Cove and Anniversary Park beaches.

In contrast, the cleanest lakes were Auburn Bay and Ghost Lake reservoir. They haven't exceeded that threshold yet thisyear.

The Elbow and Bow rivers are not being regularly tested in Calgary for recreational swimming.

WATCH | How the voluntary lake water testing program works:

Which lakes in the greater Calgary area are tested for water quality?

12 days ago

Duration 3:56

At Sikome Lake, water treatment is similar to an outdoor pool. But what about the other lakes in and around Calgary. Elise Stolte gives Rob Brown the details.

When asked what gives him confidence lakes are safe to swim in, Rizzuti said it's because there's been a lot of research done on how clean water needs to be for someone to not get sick.

"Guidelines are set based off a large pool of evidence and data," he said. "These are set based off of knowing how much would need to be there in order to make someone ill....We have a team who will issue anadvisory when it's needed."

He said if Albertanshave concerns at any location, they can flag that online and every complaint is follow up on.

What does the data actually mean?

CBC Calgary shared the water quality data with Heather Murphy, the Canada Research Chair in the area of pathobiology at the University of Guelph.

She said the Alberta guidelinesand that minimum threshold that Chestermere Lake is exceeding are generally in line with Health Canada regulations. Those rely on American studies of water risk, which define acceptable risk as 36 people getting a stomach bug or other illness for every 1,000 people who swim.

They measure for fecal or poopbacteria because it's an indicator that other microbes that cause eye, ear, stomach or other infections might be present.

"It's tricky because I also have little kids and I've wrestled with this myself," she said."What I do is I don't go after rainfall, like especially heavy rainfall within 24 to 48 hours. I would encourage the public to look at the historical water quality data and pick the beaches that have the least likelihood of exceedances historically."

"If you're seeing a lot of waterfowl in a lake where you're swimming,that's probably not great. Like a ton of Canada geese always pooping in the water where you want to go swimming.

"If you have little kids that just wanna go and wade and splash in the water and they're not ingesting, like there's still potentially risk, but maybe make sure they wash their hands before they're eating. It's head-under submersion that'sa big problem."

She said she'd like to see more government bodies publish this data publicly and make it easy to understand, such as with a green-yellow-red schema. That way, people can make an informed decision about swimming based on their own risk tolerance.