The Swimming pool hygiene standards
For standards swimming pool water quality and hygiene, the internationally recognized authoritative references mainly come from the regulations of World Aquatics, as well as the World Health Organization (WHO) Guidelines on Safe Recreational Water Environments, which are referenced by various countries when implementing them.
1. Water Quality Chemical Indicators
* pH Value: 7.0 – 7.8
Purpose: To ensure the effectiveness of disinfectants without irritating skin or eyes.
* Free Chlorine: 1.0 – 3.0 mg/L (ppm)
Purpose: To effectively kill bacteria while ensuring athletes are not affected by excessive concentrations.
* Combined Chlorine/Chloramine: ≤ 0.4 mg/L
Purpose: To strictly control the source of "chlorine smell" and eye irritation; the lower the value, the fresher the water.
* Cyanuric Acid: ≤ 30 mg/L (Recommended to be as low as possible for indoor pools; outdoor pools can be more lenient but still need to be controlled)
Purpose: To limit stabilizer content and prevent the chlorine disinfection effect from being locked in.
2. Water Quality Physical Indicators
* Turbidity: ≤ 0.5 NTU.
Effect: Must allow clear visibility of the entire pool bottom through the surface, ensuring lifeguard visibility and water clarity.
* Water Temperature: 25°C – 28°C (for competitive swimming).
Note: Excessively high water temperatures can promote the growth of bacteria and algae, while excessively low temperatures can negatively impact athlete performance.
* Total Dissolved Solids (TDS): Recommended ≤ 1500 mg/L.
3. Biosanitary Indicators
These are the most fundamental standards for measuring whether water quality is "clean," requiring that no pathogenic bacteria be detected:
Coliforms: 0 CFU/100mL
Escherichia coli (E. coli): 0 CFU/100mL (a direct indicator of fecal contamination)
Total Colony Count: Usually ≤ 100 CFU/mL (specific values vary by country, but international competitions tend to have stricter requirements)
Pseudomonas aeruginosa: 0 CFU/100mL (common in warm, humid environments, can cause skin and ear infections)
4. Circulation Filtration and Refreshing Standards
Circulation Cycle: The water in the entire pool must circulate through the purification system at least once every 4 hours (competitive pools typically require even more, sometimes up to 2-3 hours for a full pool circulation).
Replenishment: At least 5%-10% of the total water volume should be replenished daily with fresh water.
5. Special Considerations
* **UV/Ozone-Assisted Disinfection:** International high-end sports venues generally mandate the use of UV or ozone-assisted treatment systems. The primary purpose is to decompose bound residual chlorine (chloramines), improving air quality and in-water comfort.
* **Air Quality:** Ventilation standards for indoor swimming pools are receiving increased attention. It is required that the concentration of chloramines in the air directly above the water surface be as low as possible to protect athletes' respiratory systems.
Swimming pool hygiene trends are towards stricter requirements for bound residual chlorine (chloramine) and greater demand for auxiliary disinfection equipment (such as ultraviolet light). The era of simply relying on chlorination is over; now, the emphasis is on the overall hygiene of the water and air.
