Come On In, The Water's Fine!
Effective Systems to Maintain Water Quality
By Deborah L. Vence
As aquatic facilities are well into the summer season, keeping pool water clean and safe is a top priority on a day-to-day basis. Special systems are necessary in order to keep water balanced and eradicate bacteria that can cause illness.
As pointed out on the Centers for Disease Control and Prevention (CDC) website, "Recreational water illnesses (RWIs) are caused by germs and chemicals found in the water we swim in. They are spread by swallowing, breathing in mists or aerosols of, or having contact with contaminated water in swimming pools, hot tubs, waterparks, water play areas, interactive fountains, lakes, rivers or oceans. RWIs can also be caused by chemicals in the water or chemicals that turn into gas in the air and cause air quality problems at indoor aquatic facilities."
To combat RWIs, pool facility operators need to make sure they have the best systems in place in order to efficiently manage water quality, and be aware of other factors that can play a part in water quality problems.
Necessary Systems for Water Quality
"For the past 100 years, swimming pool water quality was maintained by two systems: maintaining proper disinfectant levels and filtering the water via a circulation system," said Tom Lachocki, CEO of the National Swimming Pool Foundation (NSPF), a nonprofit organization in Colorado Springs, Colo.
"Today, most new large public pools have a third system in the construction specifications. The third system is a supplemental oxidizer or disinfectant. The most common ones used are either ultraviolet light or ozone. These supplemental systems help oxidize contaminants and inactivate pathogens that they contact," he said.
What's more, system automation that links water chemistry testing and chemical addition also is being adopted in large numbers.
"Advances in electrochemical probes have helped more accurately and precisely measure disinfectant and pH," Lachocki said. "The probes are connected to a controller that signals the chemical feeders. Thus, the automated systems help facilities maintain proper water chemistry with less manual labor and cost. Several studies conducted by the Centers for Disease Control & Prevention (CDC) working with health department data show that many higher-risk pools regularly do not have the proper disinfectant and pH.
"As a result," he added, "the standard of care is to include chemical probes, controllers and automatic feeders in higher-risk environments like public spas, kiddie pools, splash pads and others."
Another trend Lachocki mentioned relates to the people who are responsible for operating public pools.
"The standard of care is that public pools are under professional supervision by certification holders from a reputable nonprofit," he said. "All the systems in the world won't keep the pool safer if the people running the pool don't understand the basics. In today's litigious world, [having] trained and certified operators is a critical part of the system that protects the public and the facility."
Juliene Hefter, executive director and CEO of the Association of Aquatic Professionals, noted that "Proper water quality starts with the proper equipment for filtering and chemically treated water."
She said a pool operator must first know the chemical makeup of their source water. "Once that is known, they are able to choose the best disinfectant and pH adjuster to use for their specific water makeup," Hefter said. "Once the system is up and running, the importance turns to water balance to ensure proper water treatment as well as the extended life of your pool equipment and fixtures."
The three main areas that have an impact on water quality are filtration, circulation and disinfection, said Kevin Post, principal, Counsilman-Hunsaker, an aquatic engineering and design firm in St. Louis. "Filtration is the process of removing small particulates and contaminants," he said. "Disinfection is the process of inactivating microorganisms and oxidizing contaminants. A pool system must both disinfect and filter to have proper water quality."
He said filtration is affected by the media of the filter. "Typical filter media for pools includes cartridge, sand or perlite (or DE)," he explained. "While sand is inexpensive and effective, perlite can remove a much smaller particulate and, therefore, achieve a higher level of water clarity."
Circulation is important, too, to make sure the water is being filtered and treated. "The two areas to look for with circulation [are] the turnover time and the distribution of the water. The turnover time is the amount of time it takes for one full volume of pool water to pass through the filter system," Post said.
Pools with heavy bather loads will require a faster turnover to maintain proper water quality.
"The distribution of the water is also key to make sure the pool doesn't have 'dead spots' where the water is not moving and, therefore, does not get filtered or treated as often," he said. "Proper placement of return inlets will reduce and eliminate any dead spots. A pool dye test can help determine if your pool has any dead spots."
A blog post on pool dye tests on Counsilman-Hunsaker's website indicated that "After a pool is constructed, and prior to receiving operational permit, a non-permanent, non-staining colored dye is added to the pool's surge tank or skimmer systems. Almost immediately, dye will be seen returning through the pool's inlets. The pool will quickly turn a purple hue and you can easily see how all the water distributes within the pool. After approximately 10 minutes, the entirety of the pool should be colored and the test is complete. A short while thereafter, the dye will disappear when chlorine is added back into the pool."
For the most part, Post noted, "all commercial aquatic facilities are required to have a halogen in the water for instant sanitation," with the most common types being "sodium hypochlorite (liquid chlorine), calcium hypochlorite (tablet chlorine), bromine (non-chlorine sanitizer) or saline (on-site chlorine generator)."
In a blog post that Post wrote on chemical treatment options for commercial pools, he stated, for example, that "Sodium hypochlorite (liquid chlorine) is approximately 12 percent free available chlorine. Sodium hypochlorite must be stored in a covered tank and a room that is ventilated to the exterior. Liquid bleach is a mild hazard. It is relatively reactive with acidic chemicals and organics.
"Calcium hypochlorite tablets are placed in canisters and pool water is bypassed through the erosion feeders, dissolving the tablets and introducing chlorinated water back into the pool. Clogging with the feeders was an issue in the past, but most of those issues have now been resolved through design.
"Bromine gained interest in the early '90s as a replacement for chlorine. Twice the bromine is required to reach the same oxidation potential of chlorine. Bromine is a much less aggressive oxidizer compared to chlorine. It doesn't combine with organics, therefore, chloramines are not produced which cause the smell in a natatorium. There are claims that bromine is less irritating to swimmers."
Besides chemical causes, there are some other factors that can contribute to pool water problems, including air circulation and debris.
"One of the main issues that we have with pools is attempting to have proper air handling in indoor pools," Hefter said. "If we do not have proper air circulation we end up with chloramines in the water, which will erode facility equipment and surfaces. Making sure that the water is balanced works to ensure that our facility and equipment lasts as well. Water that is not balanced and that is corrosive or scaling can impact every aspect of your pool."
Keeping pool water clean and clear consist of ensuring that you are constantly and properly filtering the water, keeping chemicals within the appropriate ranges as well as vacuuming out debris from the pool.
"Consistent maintenance of your pool through proper water balance, vacuuming and constant testing will ensure that your facility lasts as long as possible. Improper water balance can affect all aspects of your pool facility and equipment," Hefter said.
For example, she said, "equipment within your facility can become corroded over time and the costs for replacement parts could have a huge impact on your budget."
Meanwhile, water balance is another area of water quality that is commonly overlooked.
"A properly balanced pool will optimize the disinfection process," Post said. "Water balance looks at five factors of the pool: pH, temperature, calcium hardness, alkalinity and total dissolved solids (TDS). The pH of the water also has a tremendous impact on water quality. The pH impacts the effectiveness of the disinfection process as well as helps with water clarity."
Minimizing the amount of debris in the pool can help, too, and regular vacuuming of the pool floor should be part of any facility's maintenance plan.
Consistent maintenance of your pool through proper water balance, vacuuming and constant testing will ensure that your facility lasts as long as possible.
"It's also important to make sure the deck is clean as that debris will find its way into the pool. The use of pool covers will help overnight, but the users will track dirt and debris in throughout the day," Post said, adding that when designing a facility, it's important to keep the area immediately around the pool free of landscaping as this can find its way into the pool, too.
In response to additional contributing factors to water quality, Lachocki noted an old joke: "A patient goes in to the doctor and says, 'Doctor, doctor, it hurts when I do this.' The doctor responds, 'Don't do that.' That's our situation. No one likes the pain of red eyes and irritated skin. Ironically, we are the cause of that pain. We need to stop doing that. The science has become ironclad. Urine is the largest avoidable contributor to the formation of that noxious chloramine odor commonly detected in pools.
"The urea from urine reacts with chlorine in the water to form organic chloramines. The organic chloramines break down over a week to form inorganic chloramines that evaporate and are detected as that noxious chlorine-like odor," he said. "The organic and inorganic chloramines are irritating whether they are in the water or in the air. Thus, chemicals in urine react with chlorine to form the chemicals that give us red eyes and irritated skin."
He said there is an old myth that there's a chemical that turns red when someone pees in the pool.
"It turns out it's not a myth. When someone pees in the pool, the chloramines make our kids' eyes turn red," he said, adding that there also is compelling scientific evidence that even a quick rinse shower removes contaminants that hurt water and air quality. "Longer warm showers with soap and water are better."
Yet, some sources of contamination can't be avoided.
"We can't stop contaminants from the air or environment from getting in the water. We can't stop perspiration," he added. "However, we have some simple tips that can reduce urine, improve water quality and prevent red eyes."
Educating Swimmers on Pool Cleanliness
Industry experts offered up some tips on how swimmers can do their part to help keep pools clean.
"One of the most difficult tasks of a pool operator is attempting to educate patrons on the importance of showering prior to entering a swimming pool along with following proper hygiene," Hefter said. "Trace amounts of urine or fecal matter can enter the pool through individuals not wiping properly after using the restroom facilities. Other times, it is individuals that have fecal or urine accidents in the pool."
Hence, the easiest way to educate patrons is by providing materials on the importance of not entering the pool if they have had any sort of stomach illness or diarrhea within the past 72 hours.
"Let patrons know how fecal and urine incidents affect the quality of the chlorine in the water as well as how it can affect the health and wellness of everyone using the facility," she said.
Education is key, Post said. "Most people believe the problem with the pool is the fact that it has chlorine in it." However, the reality is that the urine and products that are being introduced to the chlorine are actually creating the problem.
"The general public must be educated to know that not peeing in the pool and showering before getting in the water will have the greatest impact on their comfort while swimming," he said. "The NSPF has created fliers that can be posted around the pool to help with this education process."
In a guest blog written by Post for the NSPF, he explained that "The pool is only creating the problem because we allow swimmers in it. Sounds funny, but any operator would agree that an empty pool is easier to maintain. As soon as users enter the pool, the chlorine starts doing its job, and chloramines will start to form. But, a pool with no swimmers doesn't really help our communities."
"So," he stated, "swimmers can help with two simple steps. First, shower before entering the pool. Far too often I hear people say, 'Well, there's chlorine in the pool, so I don't need to shower.' In other parts of the world, swimmers treat the water like drinking water, not like a bathtub. Swimmers can also help by not peeing in the pool. Several studies have found that urea (found in urine) is the main source of those pesky chloramines. If everyone would shower before getting in the pool and make sure to use the toilets when needed, we would see a huge improvement in air quality."
What's more, an infographic from the NSPF included some suggestions on "preventing pee in the pool" as well.
They comprise the following:
- Swim coaches can require a break 30 to 60 minutes into a practice.
- Parents can schedule "out of pool" snack time that give children a chance to use the rest room.
- Facility directors can schedule "Adult Only" swim time for 10 minutes every hour.
- Provide signage that reminds pool-goers to use the restroom and shower before entering the pool.
- Everyone can help by encouraging bathroom use before entering the pool, water park or aquatic facility.
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