Legionnaires Risk Assessment Template

Cooling Tower System
Cooling Tower
Take a photo of the cooling tower, including its make, model, year of manufacture, and type.
The Written Scheme

Is there a written scheme for controlling the risk from exposure to legionella bacteria?

Does the scheme contain an up-to-date plan and instructions for operating the sytem?

Does the plan show all cooling towers, system control valves, and standby equipment, e.g. spare pumps?

Does the plan show the location of the system bleed valves and drain valve?

Does the plan show all associated storage tanks and pipework?

Does the plan show the location of chemical dosing points and/or injection points?

Does the plan show the origin of the water supply?

Does the plan show any parts that may be temporarily out of use?

Does the scheme contain details of the precautions to be taken to control the risk of exposure to legionella bacteria?

Does the scheme contain details of the checks that are to be carried out (and their frequency) to ensure that the scheme is effective?

Is there any tenant, resident or regular visitor particularly suscetible to legionella due to age, health or lifestyle?

Design & Construction

Are drift eliminators fitted correctly?

Are drift eliminators effective in reducing drift?

Are all visible surfaces free from slime or algae, scale, and corrosion?

Does the water flow evenly across the fill pack?

Have dead legs/blind ends and redundant pipework & plant been removed as far as possible?

Are those parts of the tower that become wet, accessible and/or removable for cleaning?

Operation & Maintenance

Is the cooling system in regular operation?

Are there procedures in place to operate standby equipment on a rotational basis?

Is there an operations manual for the cooling system?

If the tower is used intermittently or is required at short notice, is it run at least once a week, so that water treatment chemicals are circulated to all parts of the system?

If the tower is out of use for longer than a week, are there procedures in place to bring the tower back into operation safely?

Water Treatment Program

Is there a water treatment program in place?

Are chemicals/biocides used to control scale, corrosion, fouling, and microbiological activity?

List methods used below.

If non-oxidising biocides are used, are two used alternately?

Are chemicals dosed automatically?

Are the pumps calibrated regularly?


Is there a daily check to make sure that the system is operating as described in the operations manual?

Is there a daily visual check of the cleanliness of the water in the system?

Is the physical condition of the system checked at least every week?

Is the chemical composition of the cooling and make-up water monitored on a regular basis?

Are the safe operating limits for each parameter which is being measured, known and recorded in the operating manual?

Is the corrective action for out of limit situations known and included in the operations manual?

Are results of all tests and checks recorded, together with details of any remedial action taken (if required)?

Are dip slides taken on at least a weekly basis?

Are slides incubated in an incubator (at 30°C for 48 hours)?

Are results recorded, so trends over time can be seen?

Are samples for legionella taken on at least a quarterly basis?

Have the circumstances when more frequent sampling may be required been identified and recorded?

Cleaning & Disinfection

Is there a written procedure for regular cleaning and disinfection of the system?

Does this take place at least every six months?

If the system is not shut down every six months, list reasons and alternative measures taken to ensure the cleanliness of the system below.

Does the cleaning and disinfection procedure include the initial concentration of oxidizing biocide in use for the pre- and post-cleaning disinfection stages?

Does the cleaning and disinfection procedure include contact time for each disinfection stage and methods for carrying out cleaning, including the removal of packing?

If packs cannot be removed, are there alternative methods of making sure they remain clean in place?

List methods below.

Are measures taken to protect staff when carrying out cleaning of the tower?

List precautions below.

Sign Off

Additional Observations

Landlord Name & Signature
Legionella-Responsible Person Name & Signature
Please note that this checklist is a hypothetical example and provides basic information only. It is not intended to take the place of, among other things, workplace, health and safety advice; medical advice, diagnosis, or treatment; or other applicable laws. You should also seek your own professional advice to determine if the use of such checklist is permissible in your workplace or jurisdiction.