REGULATIONS AND STANDARDS FOR PUBLIC POOLS
paddling pool, footbath, spa and pool
Different standards govern the public swimming pool regulations. Below are some important reminders for optimum management of pool water quality. The water quality of swimming pools open to the public must imperatively comply with the standards required by the A.R.S.
Here are the regulations for public swimming pools, aquatic centers, semi-public swimming pools and open to the public:
Public swimming pool regulations
The pH of the water should be between 6.9 and 7.7 ppm.
The combined chlorine (chloramines) must be less than 0.6 ppm.
Pool water without stabiliser (isocyanuric acid) should have an active chlorine content between 0.4 and 1.4 ppm.
A pool water with stabilizer must have a free chlorine of at least 2.0 ppm.
Indoor swimming pools must have a trichloramine in the air level of less than 0.5 mg/m³.
The level of stabilizer (isocyanuric acid) present in the water must be less than 75 ppm.
The mandatory supply of new water is a minimum of 30 liters per day and per bather (recommended 50 liters / bather / day).
The pH of water for public swimming pools :
In public and collective swimming pools, the regulations indicate that the pH of the water must ideally be close to 7.2 and 7.4.
How to correctly measure the pH of water ?
The pH of water is measured using a photometer for self-monitoring and a continuous analysis device for online measurement and regulation.
A balanced pH determines the effectiveness of the disinfectant and the calcium-carbon balance essential for water treatment.
An automatic regulation of pH and chlorination is strongly recommended to optimize pH and disinfection.
The importance of TAC (Complete Alkalimetric Title)
What is the TAC ?
The TAC corresponds to the quantity of carbonates and bicarbonates present in the pool water.
The TAC measurement is expressed in °F or in ppm (1 °F = 10 ppm) and determines the buffering capacity of the water.
Checking the TAC is not regulated in public swimming pools but it is recommended to check it at least once a year.
Pond water with a TAC of less than 100 ppm (10°F) causes a strong variation in pH. To reassemble it, you must use a TAC booster based on bicarbonate and sodium carbonate.
Pond water with a TAC greater than 300 ppm (30°F) causes whitish deposits on the water line and difficulty correcting the pH. To lower it you must use an anti-limescale product or even hydrochloric acid if it is very high.
A correct TAC should be between 80 and 120 ppm (between 8 and 12°F).
Calculation of free active chlorine
Active free chlorine is calculated by comparing the pH value with that of Free chlorine (DPD1).
To facilitate and avoid reading errors in the calculation table, Ozonex has created an intelligent and connected automatic regulator that can take charge of two amperometric probes in order to display at time t the value in free/active chlorine but also that of chlorine total/combined (chloramines).
The active chlorine content is determined from the measurement of the free chlorine and the pH using the following table (for a water at 25°C).
Example : at pH 7.4 for 1.6 mg/l of free chlorine, there is 0.90 mg/l of active chlorine.
Do not hesitate to start a measurement again if the value seems out of the ordinary.
Calculation of combined chlorine (chloramines)
Combined chlorine => Total chlorine – free chlorine (the rate not to be exceeded is 0.6 ppm).
Chloramines come from the reaction of free chlorine with organic matter brought in by swimmers (sweat, saliva, dead skin, etc.). It is a very volatile gas that gives off a very unpleasant smell of chlorine and gives this feeling of irritation to the eyes.
The presence of chloramines causes a feeling of irritation in the eyes and mucous membranes. In the longer term, chloramines can cause :
bronchiolitis in babies.
How to Treat or Lower Chloramines ?
maintain a pH of the water between 7.2 and 7.4.
water renewal (creates additional operating costs).
respect the main rules of hygiene :
- take a soapy shower before bathing to rid the skin of sweat, cream residue, cleanse dead skin...
- remove make-up before bathing.
- Encourage children to go to the toilet before swimming.
Using an ozonator for disinfection considerably reduces the formation of chloramines and will avoid excessive water renewal (ozone has the power to destroy all organic matter: bacteria, viruses, etc...).
Water recycling in public swimming pools
The time for water recycling in public swimming pools must imperatively be done according to the following A.R.S standards :
For a spa => 2 times the volume of water per hour.
For a paddling pool => 30 minutes minimum.
For a pool :
- with a depth less than or equal to 1.50 m => complete recycling in 1h30.
- with a depth greater than 1.50 m => complete recycling in 4 hours.
- diving pool or diving pit => complete recycling in 8h00.
We are here to help you...
Questions ? Need documentation, a quote ? The entire Ozonex team is at your disposal.