In North America, the standard protocol for water quality maintenance (WQM) is premised on the assumption that appropriate filtration and residual halogen disinfection will inactivate all pathogens. However we now know that:
- "Giardia can take up to 45 minutes to become deactivated in chlorine."
- "Noro virus takes about 30 to 60 minutes to deactivate."
- "Crypto is highly resistant to chlorine and can linger in a pool for up to 10 days."
(Refer to Inactivation time for human disease-causing microbes in chlorinated water. www.cdc.gov/healthyswimming)
Unfortunately, recreational water illness (RWI) is dramatically increasing. Research has also shown that halogen disinfection creates hazardous byproducts (DBPs). These DBPs include chloramines, THM, HAA, and other contaminates that are recognized to have serious negative health effects. It is also established that certain pathogens are resistant to chlorine and ozone, thus leading to various diseases including respiratory, skin and gastrointestinal problems. Awareness and concern about exposure to DBPs in pool and spas is increasing. Health officials have acknowledged that the increase of RWI and negative health effects associated with DBPs necessitates a paradigm shift in our thinking about how we treat pool and spa water.
Experts agree that moving beyond the basics will require revising the two pillars approach that includes filtration and halogen followed by adopting supplemental disinfection for water quality management for pools and spas.
In-line UV disinfection is recognized as an extremely effective and reliable method for deactivating pathogens in the water and reducing the bathers exposure to DBPs.
Public health authorities are already beginning to mandate supplemental in-line UV disinfection. After the Crypto outbreaks in upstate New York a few years back, the state now mandates supplemental in-line UV disinfection on all public splash parks, as do several other states, including Florida, Ontario, etc.
In some areas, chemically laden pool water cannot be put to waste as it goes directly through the aquifers and could contaminate the ground water. Water that is treated with UV light usually has drastically reduced chemical levels and can safely be drained.
Now is the time to consider a UV system to improve both the water quality and the air quality of swimming pool facilities.