Curious Iowa: How are splash pads and pools kept clean?

More than 600 people enjoyed Cedar Rapids’ municipal pools Memorial Day weekend. The holiday weekend marked the start of open season for municipal pools and splash pads.

Dawn Lambert of Cedar Rapids wondered if splash pads continuously pump clean water through, or if the water is recirculated through the system. Lambert wrote to Curious Iowa, a Gazette series that answers readers’ questions, for the answer.

We looked into how water is cycled through splash pads and we dug into the maintenance that keeps pools and splash pads safe to enjoy.

Is splash pad water recirculated?

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The City of Marion has three splash pads, and another will open in City Square Park later this year. The new splash pad will use a recirculation system, just like the splash pad at Willowood Park. In a recirculation system, water is recycled back through the system after bacteria and debris are filtered out and the water has been treated.

The splash pads at Gill and Thomas Parks use a pass-through system. Fresh municipal water is continuously pumped through the system and discarded via the drain in pass-through systems.

“I will say probably 90 percent of splash pads you see in the state are going to be your pass through systems and that’s just because one, it’s less labor intensive, you’re utilizing your municipal water to have that function,” Seth Staashelm, Marion Parks and Recreation Director, said. “I will say the pros on the recirculation system is the water conservation side of it ... but it does get more costly because you’re spending more time and more chemicals to treat it and to evaluate and inspect it, so there’s pros and cons to both.”

Staashelm said the city tests the water at least twice a day to check chlorine and pH levels. Additionally, water samples are sent in to Linn County Public Health for routine testing every month.

The City of Cedar Rapids has 11 splash pads. All of them use pass-through systems.

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Brian Ruffles, Cedar Rapids aquatics program supervisor, said staff inspect splash pads, just like playgrounds, but, “With the splash pads, the water isn’t required to be tested, so that’s just like any hose water, it’s just right from the water plant.”

Splash pads are cleaned monthly and on an as-needed basis, both Staashelm and Ruffles said.

Tony Ireland, Cedar Rapids Recreation services superintendent, said keeping drains clear is a priority. Beyond leaves and debris, Ireland said, “We also get a lot of kids that, they’re unsupervised, so they like to shove things in the drains ... so hosing those out, making sure everything drains off properly so we don’t have a flood park is a big part of (maintenance).”

“It takes a couple people anywhere from two to four hours depending on how dirty it is,” Ruffles said of the cleaning.

How much water do pools and splash pads use each year?

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It takes 500,000 gallons of water to fill the Marion city pool and 1,722,000 gallons of water to fill the Cedar Rapids municipal pools.

“Throughout the summer, pools have an auto-fill because, you know, a kid does a cannon ball, water splashes out onto the pavement, there’s evaporation, all those things,” Ruffles said. “So there is a little bit more water that goes in all throughout the summer.”

“There’s also a possibility that if we had a, for instance, glass break at a pool, then we have to drain it and refill it, so every year can be very, very different,” he said.

Ruffles said it takes between a day and a half to three days to fill pools, depending on the pool size.

Staashelm said the city communicates with the water department prior to filling the Marion city pool.

“It’s a slow process, and we want it to be slow because dumping 500,000 gallons all at once is just going to empty out their towers or be pretty hard on their pumps,” he said.

Draining is spread across a few days so that the pool water doesn’t overload the sanitary sewer lines.

“It really takes a village ... there’s a lot of work that goes into getting these pools ready to go,” Ruffles said. “We start really prepping stuff as early as March 1, and that’s just so we can open Memorial Day weekend.”

Water usage at splash pads varies based on the popularity of the parks. Staashelm said the Thomas Park splash pad uses about 30,000 gallons of water and Gill Park uses 10,000 gallons.

How are pools and splash pads cleaned?

Prior to opening for the season, pools are powerwashed.

“They have to use a mild degreaser just to get all the dirt and body oils from the season before off,” Ruffles said, “then they’ll give it a good rinse.”

Once the pools are filled, pool filters cycle the water through for about a week before chemicals are added.

“Then they’ll shock the pool to bring those chemicals up and it basically takes usually a couple of days to get everything balanced out chemical wise before it’s ready to swim,” Ruffles said.

Cedar Rapids tests its pool water every two hours during hours of operation.

Iowa state code requires pools to test their water every four hours during hours of operation, although Cedar Rapids elects to test every two hours.

“The state code only requires (testing) every four hours, but with outdoors pools and sunlight and bather loads, two hours just works a lot better,” Ruffles said. “It helps us keep on top of it a little bit better.”

The pool filter is a critical piece of maintaining a safe pool environment. Marion uses Diatomaceous Earth (DE) filters and Cedar Rapids uses sand and glass filters at its pools.

“Basically, inside the filter room there’s these giant tanks — they kind of look like submarines,” Ruffles said. “They’re filled with sand, and there’s pipes that go in and run the water through the sand, and then it comes out and goes back to the pool. Water running through that sand is what catches a lot of stuff in the filter.”

He said the filters can turn over the entire pool in six hours, meaning the pool water is completely filtered four times in a 24-hour period.

These sand filters wear out from the sand media rubbing against itself and wearing out, so the city has gradually phased in glass media in the filters at Bever, Cherry Hill and Noelridge pools.

“It’s going to sound crazy because glass in pools is a huge no-no, but it is a glass-based media that is designed for pool filters,” Ruffles said. “The nice thing about that is the oils and stuff that comes off through the pool won’t stick to that as well, so it allows it to filter a higher level, so it’s much more efficient.”

Ruffles said inside the filter, it looks like different sizes of green and brown beach glass. Water runs through the glass to capture debris and bacteria.

Staashelm said every seven to 10 days, a pool should be backwashed or run in reverse to clean the filter. Instead of dumping the water into the pool, the water is disposed of into the sanitary sewer.

Review Public Health inspections online

Linn County Public Health inspects all public aquatic facilities in Linn, Jones and Delaware counties. You can view recent inspection reports at https://publicpoolinspectionsearch.linncounty.org/Inspections/Table.

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Comments: bailey.cichon@thegazette.com