Evaporative cooling towers
For offices and manufacturing premises
If your business has air-conditioned offices or carries out a manufacturing process that uses water as a coolant, it may have a cooling tower.
Cooling towers remove heat from circulating cooling water systems, so that the water can be recirculated. The heat removed from the water is released to the atmosphere.
Most large buildings with offices, classrooms, lecture theatres or laboratories have systems that control the heating and cooling of air in the building. Sports facilities and swimming pools also use these systems. Many of these systems have cooling towers or heat exchangers which are often situated on the roof of the building.
What you must do
Register your cooling tower
If you have a cooling tower or an evaporative condenser, you must notify your local council. You must also tell them if you make any changes to your cooling tower or if you stop using it. Ask your local council's environmental health department for a cooling tower registration or notification form.
Your local council and the Health and Safety Executive (HSE) or the Health and Safety Executive for Northern Ireland (HSE NI) will carry out regular inspections to ensure that your cooling tower meets safety standards.
Check if you need a permit
If your cooling tower is part of a large installation you may need a pollution prevention and control (PPC) permit. If you are not sure whether you need a permit, contact your environmental regulator.
Pollution prevention and control permits
Contact your environmental regulator
Prevent Legionnaires' disease
You must keep cooling tower systems in good condition. If they are not properly maintained they can create the ideal habitat for certain bacteria, in particular Legionella which causes Legionnaires' disease.
You must register your cooling tower with your local council so that they can identify areas where there is a risk of the spread of infectious disease.
If cooling towers and evaporative condensers are likely to be out of operation for:
- up to a month - isolate fans, but circulate biocidally-treated water around the system for at least an hour each week
- more than a month - drain down the systems and clean and disinfect them. Clean and disinfect the systems again before refilling and returning to operation
Limit noise from cooling towers
Cooling tower fans may be noisy and cause a nuisance to the surrounding community.
If you think your cooling tower fans might cause a nuisance, you should discuss your operations with:
- your local council
- your environmental regulator if you have a PPC permit.
It is best to do this before you receive any complaints. If noise levels are too high, your local council or environmental regulator can stop your operations.
Fit ventilation silencers to your cooling tower fan inlet and discharge vents to reduce noise levels.
See our guidance on noise, odour and other nuisances.
Have a permit to discharge cooling tower effluents
If you discharge any cooling tower effluents or cooling tower blowdown to surface waters, groundwater, land or public sewers, you must have a permit or licence.
See our guidance on trade effluent .
See our guidance on water pollution.
If you are not sure whether you need a permit or licence, contact your environmental regulator or your water and sewerage company or authority.
Contact your environmental regulator
Water UK: Contact your water company
Scotland on Tap: Water and sewerage providers in Scotland
Good practice
Maintain your cooling towers
Inspect your cooling towers regularly. Be aware that your local council and the HSE or HSE NI will visit your premises to ensure you meet safety standards.
You should clean cooling towers:
- at least twice a year
- after any shutdown of more than a month
- after any major alterations.
Employ specialists to carry out cleaning. Cleaning will improve cooling tower efficiency and minimise the risk of disease.
Store chemicals safely
You may store chemicals on your site, for example for maintenance. Chemicals you receive may be supplied with a safety data sheet (SDS). The SDS contains information about the chemical, including how to store, use and dispose of it safely. The SDS may also recommend the best methods and materials to use to clean up a spill. If you receive a chemical without an SDS, contact your supplier to find out whether or not they have to provide one.
Further Information
see our guidance on chemical storage.
HSE documents:
- Legionnaires' disease. The control of legionella bacteria in water systems - Approved Code of Practice and guidance (L8 ACOP)
- Legionnaires' disease - Technical guidance (HSG274 Part 1) (PDF)