Individuals who are responsible for a facility’s cooling towers have many tasks to consider, from maintaining the system’s function to keeping it safe and abiding by local regulations. As part of this process, cooling towers must regularly undergo inspection for Legionella, a potentially dangerous bacteria that can proliferate in cooling towers before spreading to infect humans. Some cooling towers are more susceptible to Legionella than others, and understanding whether your cooling towers are at a higher risk or not is critical.
The Risk Legionella Brings
Legionella is a serious concern for cooling tower operators; in fact, the danger this bacterium poses has necessitated government-issued Legionella regulations that call for regular inspections and certification. The Legionella bacteria can cause a number of illnesses in humans, including Pontiac fever, which presents as a flu-like sickness accompanied by diarrhea, fever, muscle aches, chills, and loss of appetite.
Pontiac fever is rarely life-threatening, but Legionella also causes the much more serious Legionnaires’ disease. Unlike Pontiac fever, Legionnaires’ disease can be fatal in a significant portion of the individuals who catch it; those affected will experience pneumonia and should seek medical attention immediately. Because Legionella can cause fatal illness in humans, ensuring that it is not present in cooling towers is an important part of public safety.
What Affects the Risk of Legionella in Cooling Towers?
Some cooling towers are at a higher risk when it comes to the growth rate for Legionella, and Legionella risks come from a variety of factors, such as water temperature and quality, current treatment plans, and the type of cooling tower used. Be sure to evaluate the risk factors that your tower is vulnerable to and speak with an expert about how to resolve them.
Temperature in the Cooling Tower
One of the primary risks that contribute to the growth of Legionella is water temperature. While Legionella can thrive in any type of freshwater, it grows best between 77 and 108 degrees Fahrenheit. This means that if your water temperature is tepid, you could be providing the perfect location for Legionella to proliferate. Unfortunately, there is not much that can be done with this as cooling towers are designed to reject heat, keeping your water under 77 degrees most of the year is usually not an option.
Water Quality
Many cooling towers undergo water treatment, and which treatments you have selected for your tower will impact the quality of the water and whether Legionella can grow. You may chemically alter the pH of your water, but if you do not do any treatment for biologic hazards, Legionella can still find a foothold in your system.
Where you get your water from also matters. If your municipal water is held in a tank with sediment or rust, or if you rely on surface water that has come from lakes or reservoirs, Legionella bacteria may infiltrate your system.
Legionella Testing Methods
You may already do some water testing to check for Legionella. It is important to be aware that water sampling is limited in its usefulness, and recent studies have indicated that it may not be a sufficient method to reliably test your water consistently. Instead, you should work with an expert Legionella company that can do more thorough testing for you.
Accumulation of Biofilm
Biofilms that have formed in your water can provide a safe haven for Legionella. They shield the bacteria from changes in water temperature, which is why using a biocide or similar water treatment is part of a comprehensive Legionella strategy.
Aerosols Generated
Legionella spreads to humans via water vapor or mist. Cooling towers often operate by generating mist as part of the cooling process, so evaluating where your towers could be aerosolizing water is an important step. Be sure to know how and where your towers are putting off vapor and mist.
How to Mitigate These Risks
In order to reduce your risk of being the site of a Legionella outbreak, you must work with Legionella experts who can evaluate your system in its entirety to determine what steps you should take. Simply testing the water and chemically treating it without an in-depth understanding of your unique water situation will lead to results that are not comprehensive prevention methods against this bacteria.
Contact the Cooling Tower Experts
As you consider what risks your cooling towers pose to the public in light of potential Legionella, be sure to have Tower Water review your water system. Experts can offer personalized guidance on how to reduce your risk of Legionella, and if the bacteria is already present, they can strategize on how to tackle the issue and prevent it from recurring. Reach out to schedule an appointment with a technician so that you can develop a plan to ensure that Legionella never becomes a part of your cooling tower system.