Public swimming pool regulations on water quality

The regulation of public swimming pools is governed by different standards. Here are some key reminders for good water quality management in pools.

Réglementation appliquées en piscine publique

Regulations and Recommendations:

The quality of public swimming pool water must meet the required standards. Therefore, the following water analysis points must be observed:

  • For a swimming pool WITHOUT stabilizer, an active chlorine between 0.4 and 1.4 ppm
  • For a swimming pool WITH stabilizer, a free chlorine of at least 2 ppm
  • Chlorine combined or also called chloramines less than 0.6 ppm
  • The pH between 6.9 and 7.7
  • A minimum of 30 litres of new water per swimmer per day
  • Trichloramine levels in the air below 0.5 mg/m3 (for indoor pools)
  • And the stabilizer level (cyanuric acid) below 75 ppm

In addition, SYCLOPE also recommends monitoring the TAC and TH to verify the Taylor Balance.

  • The TAC (Full Alkalimetric Title) is between 10 and 30°F
  • And the TH (Hydrotimetric Title) is between 10 and 20°F

Here are some additional information on the regulation of public and collective swimming pools concerning ph, cyanuric acid, TAC and TH.

What is the right pH in a public pool?

The pH is defined as the hydrogen potential of the water and measures the acidity of the water from 0 to 14.

In other words, water is considered to be:

  • Acid if the pH is less than 7,
  • Neutral if the pH is 7,
  • Basic if the pH is higher than 7.

In public and collective swimming pools, regulations indicate that the pH should ideally be close to:

pH between 7.2 and 7.4

Indeed, it conditions the effectiveness of the disinfectant and the calco-carbonic balance essential for water treatment.

How to measure the water ph?

The water ph is measured using a photometer for self-monitoring and a continuous analysis device for online measurement and control.

Comment mesurer le pH de l'eau des piscines publiques

What is the definition of chlorine stabilizer or cyanuric acid?

Cyanuric acid is the stabilizer of chlorine. Indeed, alone, it is not a disinfectant. This is why it is added to the chlorinated product either in the form of rollers or manually in operation.

To do this, it is essential to maintain a cyanuric acid threshold between 30 and 50 ppm, above 75 ppm chlorine becomes ineffective.

What is the TAC (Full Alkalimentary Title)?

The TAC is not indicated in the regulation of public swimming pools, but it is recommended to monitor it at least once a year.

Indeed, it corresponds to the amount of carbonates and bicarbonates in the water. It is expressed in °F or ppm (1°F = 10 ppm) and characterizes the buffer capacity of the water.

  • Water with a low TAC of less than 10°F causes large variations of pH
  • Water with a high TAC greater than 30°F causes whitish deposits on the water line and difficulties in correcting the pH. In this case, the water is said to be buffered.

To change the TAC:

  • it is necessary to inject sodium bicarbonate among other things in order to increase it,
  • to reduce it, it is necessary to inject acid.

This is why it is advisable to maintain it between 10°F and 30°F to have sufficient buffering capacity, which ensures good water stability.

What equipment should be used to measure the water TAC?

The TAC is measured using a photometer.

What is the TH (Hydrotimetric Title)?

Like the TAC, it is recommended to monitor the TH at least once a year.

The latter corresponds to the amount of calcium and magnesium (limestone) in the water. It is expressed in °F or ppm (1°F = 10 ppm) and characterizes the hardness of the water.

There are no regulations for public pools but it is recommended to maintain the TH between 10°F and 20°F to avoid corrosion or scaling problems:

  • Water with a low TH of less than 10°F is very soft water, with a corrosive tendency on metals
  • Water with a high TH is higher than 20°F is hard water causing scale to form on the walls

How to measure the TH of water?

To measure the TH, you have to use a photometer.

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