Feature Article - November 2019
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The Air in There

Managing Air Quality in Aquatic Facilities

By Joe Bush


There's an old aquatics industry joke:

How do you ruin a pool?

Put people in it!

All comedy has some truth in it, and there's no doubt that the chemicals used to disinfect pool water are just fine if left alone. But pools are for use by humans, and when they get in, they bring organic material that activates the chlorine to do its work. When it does that job, it changes to chloramines, which produce the smell commonly associated with pools.

Those chloramines are not good for eyes or lungs, and need to be regulated with additional doses of chemicals to the water and the circulation and exchange of the air that the chloramines escape to. Outdoor pools need only manage the water chemistry to ensure swimmer safety, but indoor safety includes air management.

Today's state-of-the-art aquatic operations feature systems that include communication between water and air handling to not only improve water and air safety but also save energy. However, budget-conscious facilities don't necessarily need state-of-the-art equipment to maximize air and water safety.

In 2014, the Centers for Disease Control and Prevention (CDC) issued the Model Aquatic Health Code (MAHC) to guide government agencies and aquatic professionals in their pursuit of public health. The MAHC covers design and construction, including secondary disinfection systems to kill chlorine-tolerant germs, and policies and management, like training for pool operators to reduce pool chemical injuries, pool closures and other issues.

The MAHC fact sheet reveals the seriousness of unsafe water:


>>  Nearly 500 disease outbreaks linked to pools, hot tubs/spas and water playgrounds occurred from 2000 to 2014. The leading cause of these outbreaks is Cryptosporidium. This parasite is chlorine-tolerant and can cause outbreaks that sicken thousands.

>>  A recent study found that one out of eight (11.8%) public pool inspections and one out of seven (15.1%) public hot tub/spa inspections resulted in immediate closure because of at least one identified violation that represented a serious threat to public health.

>>  Sampling of public pool filter water found that more than half of samples contained Pseudomonas aeruginosa and E. coli or feces. Another study found one out of 12 pool filter water samples contained the parasites Cryptosporidium, Giardia or both.


The MAHC doesn't address air safety, but its council announced last March that the MAHC's Indoor Aquatic Facility Ventilation Design and Air Quality Ad Hoc Committee is partnering with Purdue University and Michigan State University to conduct a study to determine the operating conditions for indoor pools to help prevent the buildup of chloramines in the air.

The study aims to identify what design and operational issues affect air quality and climate control, and its results will be used to update the MAHC's design and operational guidelines.

Jason Schallock, chief operating officer of Anderson Poolworks, a designer and builder of commercial pools, is on that ad hoc committee and said its most recent work is exploring the relationship between water and air quality.

"We are learning more about events that spark chloramine formation and release into the air," said Schallock. "Advancements in ventilation like source capture systems help on the air side by removing airborne chloramines at the source. Better water chemistry control systems in combination with ultraviolet systems are being used to reduce combined chlorine in the water."

It's clear that just as pool water is fine until there are swimmers in it, facility air is fine until chloramines are produced. To manage both, Schallock recommended that facility operators should: maintain equipment and make sure that all systems are operating correctly; create easy-to-follow rules for users and staff that promote healthy use and care of the pool; and do not short-change dehumidification, air handling or water quality systems.

"We see a lot of these systems either 'value engineered' out of projects completely or cut down to lower quality for aesthetic components on or in the building," he said.

The push for better air quality is more recent than developments in water quality management with chemicals, which has its roots in the early 1900s. According to George Bailey, vice president of sales and marketing for a South Carolina-based manufacturer of instruments and chemistries for testing water parameters, testing the water is imperative to better management and safety, and it has evolved in the past 50 years from test strips to the improvement of those strips to the use of photometry and linking to mobile device applications.

Bailey said the MAHC has illustrated the need for water test kits that have been certified to perform to standards of accuracy, reproducibility and repeatability. Certified test kits are given a rating of Level 1, 2 or 3, with Level 1 being the most accurate. Operators should keep some water testing basics in mind, Bailey said.

"When testing with a certified water test kit, it is important to follow each manufacturer's test instructions to the letter since they may differ from similar test kits," he said. "Always use fresh reagents or strips that have been stored in a cool dry area away from chemicals. Heat and moisture are their worst enemy because they will drastically shorten shelf life. Only use test kits specifically designed for pool and spa use."