HSE ACOP L8 for Legionella Control stipulates a minimum Spring and Autumn frequency of Cooling Tower cleaning and disinfection.

Routine Seasonal Cleaning

HSE ACOP L8 for Legionella Control stipulates a minimum Spring and Autumn frequency of Cooling Tower cleaning and disinfection. More frequent cleaning may be required which is dependant on site conditions. The tower drift eliminators must be removed and all parts of the system must be safely accessible for cleaning purposes.

Whilst it is difficult and costly to remove the pack material on each occasion it must be inspected and confirmed in good condition and fit for purpose. Sections of packing may be removed and examined.

Access platforms should be provided by site to enable safe and effective access to all parts of the tower structure.

If on-line chlorination / bromination is utilised as part of the routine water treatment regime cleaning of the tower internals is still considered best practice.

Problems arise with continually operated systems where downtime of the cooling system is minimal. A risk assessment must be carried out on the regime and plant to ascertain if the control measures are sufficient. However, best practice would be to physically clean and inspect all parts of the plant as specified by the HSE ACOP L8.

The method employed is clearly laid out in HSE ACOP L8 especially with regard to pre and post chlorination contact times and the effect of ph on chlorine residuals.

Depending on the outcome of the site risk assessment, we would strongly recommend the annual cleaning and chlorination of all cold water tank installations, with the inclusion of the hot and cold outlets if permissible.

Hot water calorifiers should be annually inspected and cleaned as part of the domestic services chlorination (if possible)