Secondary Sanitation: A civic responsibility for aquatic professionals

The Center for Disease Control and Prevention developed the Model Aquatic Health Code to educate state and local authorities on safe and healthy best pool practices. With the MAHC, the CDC aims to decrease the amount of recreational water illness (RWI) outbreaks in public pools using traditional chlorine sanitation. MAHC recommends both primary and secondary disinfection for RWI protection in public pools. Primary disinfection options, like chlorine or bromine, kill common pathogens and are required for all public swimming pools. Secondary disinfection solutions like UV, ozone and other advanced oxidation systems are used to kill chlorine-resistant organisms, like Cryptosporidium. Complementing a primary disinfection method with secondary sanitation allows aquatic professionals to protect their patrons and lower risk of RWI breakouts. With three general secondary sanitation solutions to choose from - UV, ozone and hydroxyl-based advanced oxidation - aquatic professionals can benefit from knowing how each operate and compare.

UV

UV sanitation systems inactivate contaminants by flowing water over a UV bulb in the pool plumbing. UV is a light-driven process that prevents chlorine-resistant microorganisms, like Cryptosporidium, by deactivating the microorganism's DNA, leaving intact bacterial cells in the pool. Research has also shown that UV sanitation can increase the rate of free chlorine consumption. On the financial side, UV is typically the most expensive secondary sanitation method to operate because of its installation cost, required professional maintenance and high energy consumption.

Ozone

Ozone sanitation systems operate by injecting ozone gas into the pool circulation system. The ozone gas dissolves in the water to kill and oxidize microorganisms, destroy organic compounds and break down chloramines. In addition, ozone is a toxic gas that can be harmful at high levels and it can accumulate in pool pump rooms and under pool covers. Ozone gas can be corrosive to pool equipment and typically doesn’t scale well with large bodies of water with high bather loads.

Advanced oxidation technology

Advanced oxidation technologies including Clear Comfort’s sanitation system generates hydroxyls that oxidize unwanted organics in the pool faster than chlorine. This allows the free chlorine to break down the remaining organic matter easier. Commercial pools using Clear Comfort have cut their chlorine consumption and costs by 50+ percent. In addition, Clear Comfort’s technology is university-lab proven to completely destroy 99.9 percent of the RWI Cryptosporidium. While AOP technology has been proven as a secondary form of disinfection, and Clear Comfort has proven effectiveness disinfecting Crypto, the MAHC currently does not recognize these tests for their secondary disinfection standard. The MAHC is a living document that is open for revision every three years. Aquatics professionals shouldn’t ignore the CDC’s MAHC and let their facility's reputation and patrons suffer from a Cryptosporidium outbreak. Secondary sanitation at public pools can keep patrons safe, healthy and give aquatic professionals peace of mind during summer.