Chloramines in public swimming pools
The problem of chloramines in public and collective swimming pools is a recurring subject.
But what is it really about and how to treat chloramines?
What is chloramine?
It is created by the reaction of chlorine when it acts as a disinfectant on organic matter brought in by bathers (sweat, cream, saliva, urine…).
Inorganic chloramines, i.e. without organic radicals, result from the reaction of chlorine (in the form of hypochlorous acid HOCl) with ammonia (NH3). Examples are monochloramine (NH2Cl), dichloramine (NHCl2) and trichloramine (NCl3).
Wikipedia : https://fr.wikipedia.org/wiki/Chloramine
Why treat chloramines?
Regulations require that its value does not exceed 0.6 ppm in water.
It is necessary to treat chloramines in water:
- In order to avoid overflows caused by additional water supply.
- In addition, too many chloramines in the water can generate trichloramine in the air and can be a potential health hazard for bathers and employees. The management of trichloramine will also require additional air treatment and thus additional costs. Solutions are available for the measurement of trichloramine in air.
How to decrease or remove chloramines?
The pH of the water must be maintained between 7.2 and 7.4.
The Hygiene rules
There are also simple hygiene rules that can considerably reduce the level of chloramines.
The main ones are:
- Take a soapy shower before bathing in order to rid the skin of sweat or sun cream residues, to reduce the amount of organic matter brought by bathers into the pools,
- Take off your makeup before swimming,
- Encourage children to go to the toilet before swimming.
It is also recommended to carry out strippings at the level of the buffer tanks (waterfall with large air intake) in order to transfer the chloramines from the water into the air and evacuate them by suction.
The water supply
Water renewal reduces chloramines but generates additional operating costs.
How to measure chloramines?
Chloramines or combined chlorine are calculated as follows:
CHLORAMINE = TOTAL CHLORINE – FREE CHLORINE