Cryptosporidium and Giardia contamination

Swimming pools, spa pools and hydrotherapy pools may present an increased risk of infection if topped up with water contaminated with Cryptosporidium or Giardia. Therefore, pools should not be topped up or filled during a boil water alert.
Topping up swimming pools
When swimming pools, spa pools and hydrotherapy pools are topped up:
  • the process should be undertaken at night
  • adjust pH to 7 and superchlorinate the entire pool to 20 mg/L for 10 hours or adjust pH to 7 and superchlorinate at 10 mg/L for 20 hours
  • free chlorine should be allowed to drop below 5 mg/L before swimming
Swimming pool filtration systems should then be allowed to run continuously for seven pool turnovers. One turnover is when the complete volume of pool water has passed through the filter once.
Filter backwashing should be undertaken frequently and regularly.
Free chlorine levels should be maintained at greater then the minimum recommended levels at all times (>2 mg/L for indoor pools; >1 mg/L for outdoor pools).

'Boil Water Alert' precautions for:

Current as at: Tuesday 31 March 2009
Contact page owner: Environmental Health