If you work with cooling towers in any capacity, you’ve likely been warned about Legionella. This nasty type of bacteria spreads via water, and when it enters the human body, can result in Legionnaire’s disease – a serious type of pneumonia (lung infection).
Legionella is arguably one of the top concerns all facilities with cooling towers face. Not only do you need to stay on top of the bacteria’s spread, but you also need to be prepared for potential outbreaks that jeopardize other people’s health.
Unfortunately, cooling towers provide an exceptional setting for Legionnaire’s disease to spread, especially when they’re not properly maintained. High levels of moisture and poor airflow contribute to an environment in which Legionella thrives.
So, what can you do to reduce the risk of Legionnaire’s disease outbreaks? Here are six important steps to take when installing and maintaining a cooling tower.
1) Design Cooling Plants to Prevent Bacteria Spread
Cooling tower design plays a significant role in controlling bacteria spread. Today, most cooling towers are built with high-efficiency drift eliminators and carefully planned piping to prevent stagnant water. Additionally, most are built to recirculate water during intermittent operation, which keeps bacteria from thriving in moist, still environments.
Every cooling tower uses water evaporation to remove heat, then release it into the atmosphere. The two main kinds of towers, open and closed circuits, essentially require the same design and maintenance.
Still, it’s important to note that closed-circuit cooling towers have an additional closed-loop that prevents water droplets from spraying into the air, releasing any bacteria that has spread. Therefore, if you are worried about Legionnaire’s disease outbreaks, you may want to opt for a closed-circuit system.
If you’re implementing a new cooling tower system, you have the opportunity to design around contributing factors to bacteria growth. However, if you’re working with an older system, you may need to focus more on continuous maintenance rather than preventing Legionnaire’s disease outbreaks.
2) Automate Anti-Corrosion and Anti-Scale Measures
The next step in preventing the growth and spread of bacteria: automate your water treatment system, including your anti-corrosion and anti-scale measures. Maintaining and operating your building’s equipment helps prevent organic debris from contaminating your water system, which provides necessary nutrients for Legionella.
When bacteria, fungi, and algae begin to grow, they form biofilms in the cooling tower, which contributes to corrosion and increases the risk of an outbreak. Similarly, scaling occurs when calcium or water hardness-based salts accumulate on surfaces, reducing the ability to properly transfer heat.
Although you can manually clean the tower and watch for signs of buildup, a better strategy is to automate your preventative maintenance.
At Pinnacle CTS, we’ve helped many cooling tower facilities find better (more automatic) ways to prevent, control, and treat corrosion and scaling. In turn, this automation keeps the tower safer and lowers the risk of serious bacteria outbreaks, including the spread of Legionella.
3) Operate at the Lowest Possible Water Temperature
Legionella bacteria operate best in water temperatures between 77 and 113 degrees Fahrenheit. Therefore, one tactic for preventing its growth is to keep cool water cool and hot water hot.
We often recommend that cooling tower facilities scale back their water temperatures to “ambient,” or under 75 degrees Fahrenheit. This makes it exceedingly difficult for bacteria to grow and can dramatically reduce the risk of Legionnaire’s disease outbreaks.
How do you know if your cooling tower is running at the right temperature? We recommend scheduling a professional maintenance appointment every few months. This allows you to check on your cooling tower’s temperature range, as well as to test for bacteria like Legionella.
4) Frequently Check Disinfectant Residual and pH Levels
Speaking of regular maintenance, prioritize monitoring your disinfectant residual and pH levels. These water parameters are a strong indicator of the risk of Legionella.
Your cooling tower’s pH levels should remain between 6.5 and 7.5, although some non-acid treatments for scale prevention do raise this number to 8.5. Generally, you’ll measure these levels based on your tower’s particular performance, as well as external risks for Legionella such as temperature.
If your tower is older and more difficult to check, you may want to consider making some upgrades to the gear. Pinnacle CTS can help you fight against Legionella with upgrades to the water distribution system, drift separators, and other elements.
5) Prevent Stagnation in the Towers
As we mentioned earlier, stagnant water is a risk factor for bacteria growth. Not only does Legionella thrive in stagnant water, but the stillness also prevents proper chemical treatment that would otherwise prevent dangerous growth.
Ensure that you flush your tower’s low-flow pipe runs and dead legs at least once a week. If you are running multiple cooling towers at once, work to balance your operating times so that water is never stagnant.
Also, consider implementing an automated blowdown system that discharges water and replaces it to maintain its quality. If you can make this process quick and automated, your chances of avoiding bacteria buildup are much stronger.
If you have problems with stagnation in your cooling tower, talk to our team. Pinnacle CTS will help you find ways to keep the water fresh and moving to alleviate the risk of Legionnaire’s disease, among other serious concerns.
6) Schedule Annual Disinfection and Cleaning
Lastly, stay on top of your cooling tower system cleanings. Annual disinfections and washes ensure the air stays safe and is the best way to protect against contaminants like Legionella. Furthermore, annual cleanings are an excellent way to extend the life expectancy of your tower and avoid big repairs later on down the road.
Although annual disinfection and cleaning are important, that’s the minimum. Our experience serving cooling towers throughout New Jersey indicates that it’s even better to schedule cleanings at least twice a year, if not more frequently.
The bottom line is that if you can’t remember the last time your cleaning tower was professionally serviced, it’s probably time to book an appointment – both for the sake of the tower and for the safety of everyone nearby.
Need Help Maintaining Your Cooling Tower?
Cooling tower maintenance isn’t just about extending the life of the tower – it’s about protecting everyone who works in the vicinity of the equipment. It’s crucial that all cooling tower facilities prioritize cleaning and preventative steps so that everyone breathes safe air.
Contact us
To learn more about cooling tower cleaning in New Jersey or more about the risk of Legionnaire’s outbreaks, contact Pinnacle CTS at 732-570-9392 or send us a message online. We’ll walk you through the crucial steps to staying safe and provide expert guidance to care for your cooling tower.
