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SPN OCT 2012 UVSystems
www.swimmingpoolnews.co.uk
atg UV Technology UV system undergoing independent third party validation
ABOVE: Computational Fluid Dynamic (CFD) used by atg to predict performance before systems are sent for independent validation
ATG TO COMPLY WITH US MODEL AQUATIC HEALTH CODE
atg UV Technology are to standardise their swimming pool UV systems to be fully compliant with a United States based Model Aquatic Health Code regulation which offers pre-set options tailored to the specific needs of swimming pool operators.
It is a significant move for the UK company as the code offers increased value for swimming pool operators with guaranteed performance and reliability.
Typical swimming pool UV units should include 316L stainless steel chambers, UV monitoring, automatic wiper systems, strainer baskets and the option for half to full power for energy savings during periods of no/low use.
Although many aspects of the design and construction of aquatic facilities are governed by regulation other aspects are based on custom and practice from many years of experience. The Centre for Disease Control in the United States launched the Model Aquatic Health Code bringing together industry professionals in diverse technologies.
The code has been in development since 2005 and finally many of modules are now available for public review.
There are typically two types of UV systems available; traditional axial UV systems with inlets and outlets at either end of the chamber that offer swimming pool operators increased flexibility for retrofits or replacement of existing UV systems. For new modern facilities or where
restricted plant room space is an issue, ultra efficient in-line UV systems are favoured. The collation and use of the latest science is expected to create a document that many aquatic facility regulators around the world will be able to use as a reference for their own local regulations.
One of the areas of the code is the application of UV disinfection, particularly for the control of cryptosporidium.
UV systems have two functions. Firstly they are able to destroy chloramines. Chloramines are formed when free chlorine reacts with organics such as sweat, body fats and urea, brought into the pool environment by bathers. Trichloramines in particular are powerful irritants which are responsible for ‘burning red eyes’, itchy skin, respiratory complaints and the often over powering chlorine smell associated with indoor pools. Additionally chloramines are also the cause of corrosive condensation, which leads to the damage of pool buildings and structures such as ventilation ducts.
Secondly, they are able to provide disinfection of chlorine-resistant micro-organisms such as
CHILDREN’S SWIMMING POOLS CAN BENEFIT MOST FROM UV SYSTEMS
It’s not an insignificant fact that children’s pools, often shallow, warm with a high surface- to-volume ratio, and the water is frequently agitated by the use of fountains, and slides which is at most risk from infections. All of these conditions encourage the formation and release of the trichloramine species, which can be removed using UV light. When bathers use chlorinated swimming pools, a variety of chemicals are introduced in the process. Not in-frequently, pool hygiene is poor and those entering a pool have not showered to remove sun creams or hair gel.
These organic pollutants react with the chlorine to form combined chlorine, and one of these, trichloramine has a marked acrid odour. It is the main cause of red eye and is linked to elevated levels of asthma in children.
cryptosporidium and giardia, which have a thick outer membrane making them highly resistant to traditional chlorine disinfection. It is this second benefit that is most significantly addressed in the code. A number of cryptosporidium outbreaks in aquatic facilities in the United States have created considerable interest in the best practice method to apply this technology.
The code considered many aspects of UV disinfection and focused on the following key performance areas for application to swimming pools.
As aquatic facilities with high bather loads of younger children are both more likely to result in outbreaks and to have occupants more susceptible to cryptosporidium, the code requires that certain facilities meeting these criteria must include a method to kill or remove cryptosporidium quickly from the water. UV disinfection is one of the techniques that is accepted as having the required level of science to prove its performance.
As any UV disinfection system is a physical not a chemical process, the performance
High bather loads of younger children are more likely to result in outbreaks of cryptosporidium
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