How to restart cooling towers prior to resumption of business?

Premises owners/occupiers are reminded that all Cooling Towers which have not been in use for more than 5 consecutive days during the Circuit Breaker period, shall be thoroughly cleaned and disinfected before re-starting.


To provide sufficient time for the cleaning and testing of Cooling Towers to be undertaken prior to the reopening of their premises, premises owners or occupiers are allowed to prepare their Cooling Towers early so that they can be ready for use when the circuit breaker measures are lifted. Sufficient time should be given for the required tests to be done, including that for Total Legionella Counts (TLC), which takes about 7-10 days. The TLC is valid for 3 months while the SPC is valid for 1 month. The Cooling Towers water treatment regime shall revert to that of the pre-CB period for all Cooling Towers after they are successfully re-started.


Water samples shall be collected at least 24 hours after thorough cleaning and disinfection are completed and tested by laboratories accredited by Singapore Accreditation Council (SAC). The water samples must pass the regulated limits stipulated in the Environmental Public Health (Cooling Towers and Water Fountains) Regulations before re-starting. Premises owners or occupiers are required to keep a copy of the service reports and submit them to NEA when required.


As prolonged stagnation of water in Cooling Towers may amplify microbial growth, maintenance personnel should don proper personal protection equipment (PPE) as part of safe work procedures to protect themselves


All premises owners/occupiers to remain vigilant in ensuring that the water quality in Cooling Towers pass the regulated limits, so as to minimise risk of waterborne infection. NEA will continue to carry out checks on the water quality of Cooling Towers.