Evaporative cooling system water treatment
At Aquatrust, we provide planned water treatment, monitoring, cleaning and disinfection for cooling towers, evaporative condensers and adiabatic coolers.
Every programme is tailored to your water system. Our engineers help you manage Legionella risk, control scale, corrosion and fouling, and keep your cooling plant operating effectively.
Over 20 years’ experience in water safety and compliance.
We are registered with the Legionella Control Association for evaporative cooling system water treatment and for cleaning and disinfection.
What our evaporative cooling service covers
Evaporative cooling systems use water and air to remove heat. We treat cooling towers, evaporative condensers and adiabatic cooling systems where water is recirculated or aerosols can be generated. Effective water treatment and monitoring help control Legionella and other risks.
We start by surveying the system and reviewing your existing Legionella risk assessment. From there, we agree a programme based on the system, water conditions and how it operates.
- Chemical dosing for biocide control, corrosion inhibition and scale control
- Scheduled engineer visits for water testing and dosing adjustments
- Analysis of pH, conductivity, biocide residuals, total viable counts (TVCs) and Legionella, carried out at the frequency set out in your written scheme of control and relevant HSG274 Part 1 guidance
- Planned and emergency cleaning and disinfection using appropriate chemical methods, including chlorination where specified
- Clear records of visits, results and actions
The frequency of visits, testing and cleaning will depend on your system, its design and operation, and the requirements set out in your Legionella risk assessment and written scheme of control. We also consider the treatment required, results and trends from ongoing monitoring, and relevant HSG274 Part 1 guidance. We’ll explain what’s needed and agree the scope with you before work begins.
The risks our water treatment programme helps control
Effective water treatment looks after the condition of the whole system, rather than focusing on Legionella alone. Scale, corrosion, fouling and biofilm can affect performance and create conditions where bacteria are harder to control.
Legionella and other microbiological risks
Warm, recirculating water can allow Legionella and other bacteria to multiply, while the fine water droplets released by the system can carry them into the air.
A treatment programme uses biocides and regular monitoring to help control microbial activity in the circulating water and on system surfaces.
Scale
As water evaporates, the minerals dissolved in it become more concentrated and can form scale inside the system.
These deposits can reduce heat-transfer efficiency, restrict flow and increase energy use or reduce cooling performance.
Corrosion
Cooling water comes into contact with metal pipework, heat exchangers and other system components.
Without the right treatment, corrosion can damage these parts and create deposits that support bacterial growth.
Fouling
Airborne dirt, debris and other particles can collect in cooling water and form deposits within the system.
These deposits can affect water flow and cooling performance, while providing conditions that support microbial growth.
Biofilm is a layer of microorganisms that forms on wet surfaces and can protect bacteria from biocides, making them harder to control.
These problems are closely connected. Poor control of scale, corrosion and fouling can create conditions that make Legionella harder to manage. This is why HSG274 Part 1 treats microbial activity, corrosion, scale and fouling as parts of the same water treatment programme.
Examples of deposits and build-up
These examples show different levels of deposits and the action recommended in each case.
What to expect from your water treatment programme
How pricing works
We provide this service on a contract basis. We don’t publish standard prices because the level of treatment and monitoring required varies between systems and sites.
Your custom quote is based on:
The type, size, and condition of your system
Local water quality
The required monitoring frequency
Chemical requirements
The sampling schedule
The scope of any cleaning and disinfection
Who should arrange Legionella risk assessments?
Under the Health and Safety at Work Act 1974 and the Control of Substances Hazardous to Health Regulations (COSHH), anyone responsible for a building with a water system needs to have a Legionella risk assessment in place.
The duty holder is usually:
The employer, where there's a risk to employees or others
A self-employed person, where there's a risk to themselves or others
The person in control of the premises or its water systems – for example, a landlord responsible for maintenance
If your building has hot and cold water systems, cooling systems, showers or any other system that holds or distributes water, you need an assessment in place. It also needs to be reviewed regularly, particularly if there's been a change to the building, the water systems or how the premises are used.
Our risk assessment is offered as a standalone service or we can offer a range of complementary services including Legionella monitoring, remedial works, and cleaning and disinfection. Our Legionella risk assessments are carried out in-line with ACoP L8, BS: 8580 & HTM 04-01.
Who we work with
Facilities and estates managers responsible for safe operation, compliance and maintaining reliable records.
Engineering and maintenance managers looking to protect cooling plant from scale, corrosion and fouling, and maintain efficient heat transfer.
Responsible persons and health and safety leads who need evidence that risks are being monitored, results are being reviewed and any necessary action is documented.
Operations leads focused on keeping cooling plant available and reducing disruption from urgent remedial work.
We provide evaporative cooling water treatment for manufacturing sites, data centres, hospitals, hotels and other commercial and industrial premises.
Compliance and record keeping
The legal responsibility for controlling Legionella remains with the dutyholder, usually the employer or person in control of the premises. Our role is to support you by carrying out the agreed water treatment, monitoring, cleaning and disinfection, and documenting visits, results and actions.
ACoP L8 sets out the dutyholder’s responsibilities for assessing and controlling Legionella risk. HSG274 Part 1 provides technical guidance for evaporative cooling systems, including water treatment, inspection, cleaning, disinfection and water quality monitoring.
The records we provide support your written scheme of control and give you an audit trail of the work carried out. They sit alongside the wider compliance records you are responsible for maintaining.
Related services
If you’re responsible for other water systems across your site or estate, we can also help with:
Frequently asked questions: Legionella risk assessments
It’s the ongoing treatment and monitoring of recirculating water in cooling towers, evaporative condensers and similar systems. It helps control Legionella as well as scale, corrosion and fouling. This supports safe operation and helps the system continue to transfer heat efficiently.
Talk to our water treatment team
If you’re responsible for a cooling tower, evaporative condenser or adiabatic cooler, the first step is a site survey. We’ll survey the system, review your existing Legionella risk assessment and recommend a programme based on what we find. We’ll then provide a site-specific quote.
