Legionella control – why is so important?

Cooling towers provide ideal conditions for a complex assortment of pathogenic microorganisms. However, out of all the microbes, none have the ability to distress water managers like Legionella!

This commonly occurring bacteria is not only potentially deadly but notoriously difficult to treat, multiplies quickly, spreads easily and can survive in a wide range of traditionally hostile environments. Legionella has been attributed as the cause of multiple outbreaks of pneumonia globally.

Unfortunately, Legionella bacteria have found a ready niche in building and water systems. Cooling towers are ideal environments for the multiplication of Legionella and can spread this bacteria over a wide geographic area. They are often the leading culprit of Legionellosis outbreaks but other water systems, such as water distribution systems (including drinking), spas, saunas, aerators, and medical equipment also possess the ideal temperature, nutrient loading, and slow or stagnant water for this kind of outbreak.

From water systems to respiratory systems

So how can this happen? Legionella bacteria are generally transmitted to humans by any route in which water molecules may enter the lungs. An infected source like a cooling tower can disseminate these droplets containing Legionellae over significant distances. When this occurs, most or all of the water in the droplet evaporates quickly, leaving particulate matter that is small enough to be inhaled. Particles of <5um in diameter can be deeply inhaled and enter the respiratory airways to cause Legionellosis.

Preventing Legionella growth

The importance of comprehensive water treatment programs to maintain the function and safety of cooling towers is often understated. Processes that occur within the tower can impact the entire cooling system within a building or plant therefore the constant maintenance and monitoring for Legionella appear to be important factors in the success of a Legionella management program.

The chemical agents to be used for disinfecting, water temperatures recommended to limit Legionella growth, frequency of cleaning, and other considerations for decreasing Legionella growth in water cooling towers must all be considered.

Nine out of ten times the disinfection will be effective, but if the treatment program and risk management program aren’t in place after the disinfection, nine out of ten times this bacteria will just grow back to the same level as before.

Why is regular cleaning so imperative in cooling towers?

Regular cooling tower cleaning and maintenance has multiple benefits in protecting both the system equipment and reducing associated health risks.

Lasts longer – regular maintenance and cleaning will remove or reduce harmful processes, which degrade cooling tower infrastructure over time. Cleaning removes corrosive microbes, which scour and foul structures and prevents biofilm/residue build-ups which can cause long-term effects. This combats obsolescence and lengthens the life of the equipment.

Perform effectively – regular visits to remove damaging particles and perform diagnostic tests expose flaws so that tailored programs can be implemented to improve efficiencies. Remote monitoring technology improves equipment longevity and reduces operation costs.

Cost effective – regular monitoring enables problems to be addressed as they are discovered, preventing more damage or loss of equipment. It is easier to tailor a treatment program to prevent damaging processes then to discover loss and ineffective equipment once it has occurred. Asset protection extends the expected lifespan of the asset; it reduces Operational Expenditure/Capital Expenditure and Life Plan Expenditure.

Heating and cooling are key energy drivers in the HVAC industry, which along with water usage, represent the largest operating expenses in commercial and industrial facilities. The cost of related water treatment programs is usually only a fraction of this (1-3%), however they have the single largest direct impact on power and water costs.

Operate safely – we ensure that the equipment in your building is performing correctly, and not harboring any potential lethal pathogens.

To minimise the potential that a cooling tower has of harboring pathogenic microbial communities in faulty drift eliminators, water splash-out and dirty fill-packs, our maintenance plan includes:

  • Optimises the management of cooling tower
  • Reduces water loss and improves productivity
  • Minimises scaling and deposit of sediments
  • Reduces corrosion
  • Prolongs the lifespan of the cooling tower
  • Provides safe water for discharge
  • Leads to improved environmental practices
  • Supplies reusable processed water
  • Reduces the cost of operation

The SAS Difference

With a strong reputation as a competent and experienced service provider, we:

  • Turn intangible services into tangible benefits.
  • Offer quantitative data: HCC/Legionella counts, corrosion testing results, operating parameters, and costs.
  • Are an expert team. First and foremost, our key differentiator is our people, supported by our products, our systems, and our ability to listen to and understand the customer and what their key needs and deliverables are.

Research Department

  • We have a dedicated in-house research department specifically tasked with investigating the latest research and methods to monitor towers accurately and effectively.
  • We use science-based processes to develop and tailor system-specific treatment programs.
  • We have developed a proprietary risk matrix that uses various data sources to identify the risk a tower has for bacterial growth.
  • We are pioneers in water treatment. We do not accept the status quo and are constantly researching ways to improve the water industry and treatment programs to extend the lifespan of equipment and mitigate microbial issues before they become a problem.
  • We are committed to best-practices in monitoring and application of chemicals. Our experienced technicians will apply only what is needed for your system, which prevents over-dosing and saves you money.

Why is it important to use reputable water service providers?

Instead of a generic clean and maintenance, which may skim over potential problems manifesting, trained technicians will be able to investigate the semantics of the system, and use their specialised training to identify other features that may be impacting the system.

The severity of potential outbreaks of Legionella cannot be understated, and it is highly undesirable for any building operator to have an outbreak. Not only would it be harmful to the your people and the public but incredibly damaging to the reputation of your business.

  • You want to choose a provider who will quickly be able to identify, respond, and neutralize the problem before it becomes an issue.
  • You want a company that understands NSW Government’s strict regulations on reporting and testing for Legionella.
  • You want a trusted provider who you have confidence will actively work to develop a treatment plan that works for your site.
  • You want to know we are not a chemical manufacturer looking to make profit, but one that will tailor a program to be the most efficient and effective for your business.

Specialised technicians

We have trained tertiary qualified specialists and service engineers and technicians with extensive knowledge and water industry experience.

Our specialist service technicians, armed with the latest sophisticated equipment and our proprietary chemicals, have the knowledge and skills to provide specialist on-site testing, monitoring, sampling, analysis, validation, and detailed reporting for water treatment and microbiological control.

Detailed reporting

Our in-depth understanding of the factors that affect Legionella survival and growth in the natural environment is important when controlling the bacteria in artificial water systems. It allows the areas at most risk from Legionella colonisation in such systems to be identified, thereby indicating the points at which control measures will be most effective.

Our experienced technicians have this keen technical eye to spot situations that will increase Legionella growth and pre-emptively mitigate this risk before it has a chance to become an issue.


Our state-of-the-art SENTINAL dosing and control hardware provides ongoing optimisation and 24/7 security against any non-conformance.

Our innovations in sensor technology and building automation systems allow us to gain greater visibility into the operation of cooling towers, providing access to information that was not previously available.

Utilising single-point monitoring systems to get frequent updates on all systems allows us to easily and pro-actively pinpoint any potential problems.

A well monitored system means we never play catch-up and can take preventative maintenance to replace parts when needed, prolonging the longevity of your water system.

Tailored treatment plans

Our specifically formulated chemical products are proprietary to SAS so we include the highest quality raw materials in our finished products to ensure the best situational efficacy.

SAS’s main point of difference is our in-house ability to provide the most suitable and effective water treatment solutions to treat waterside problems whether chemical, biological or mechanical. We select the most appropriate option, free from any conflict of interest. This coupled with our in-depth industry knowledge, qualified expertise from the company’s front line service engineers, as well as technical and management support, rightly differentiates us from our competition


We utilise the services of specialist NATA accredited labs in Sydney for carrying out and conducting comprehensive lab testing and analysis for water treatment and microbiological management and to provide comprehensive reports.

Is your water being managed safely?