Essential Tips for Legionnaires Prevention in Cooling Towers

Legionella Bacteria

It is common for the cooling towers to get contaminated with the Legionella bacteria at some or other point in time. Though you can’t prevent the entry of organisms in the cooling towers, an effective water treatment program can help in reducing the risk of Legionella and also make sure safe operations and longer system life of the cooling tower. It is important to follow the Legionella Regulations for Legionnaires prevention.    

Good maintenance of the cooling towers is necessary for keeping Legionella at bay. Cooling towers are a concern as they contain warm water which is the perfect place for the Legionella bacteria to breed if the towers are not cleaned properly. Thus, it is the responsibility of the owner to manage the risk.

Here’s a look at the risks and how to prevent them:

1.    The quality of source water

The water usually comes from municipal or well supply but can come from a holding tank as well which can sludge and rust. The surface water coming from lakes, rivers, and reservoirs is less commonly used and can be full of microorganisms. 

Prevention- The cooling water should be cleaned twice a year along with disinfecting the entire tower by removing any rust, and sediment. Antimicrobial treatment is suggested if the water is coming from a lake, river, or reservoir. The treatment should be done before the water enters the cooling system so that fouling can be prevented.

2.    Water treatment

The temperature and the flow velocity of cooling tower water vary along with other aspects that affect water treatment.

Prevention- The system needs to be designed in a way that water can circulate through the system whenever it operates. The system operation should be coordinated with the chemical treatment of water. The system should be kept clean by removing the debris and dirt. If the water system is shut down for three or more days, the entire system needs to be drained.

3.    Disinfection

Since the cooling towers are open to the environment, the system can quickly become re-colonised with microorganisms even after chemical treatment was done.

Prevention- The cleaning technician needs to vary the antimicrobial stresses applied in the cooling tower microbial control program.

4.    Biofilms

During the cooling tower processes, dust, dirt, and other particles enter the cooling tower water. Based on the location of the cooling tower, the amount of material can vary. Presence of biofilms is important for Legionella survival and growth providing nutrients in water systems.

Prevention- It is strongly advised to use a compatible and environmentally acceptable detergent for penetrating the Biofilm and sediments. Make sure you follow the right cleaning and maintenance for your cooling system to minimize the risk of disease.

5.    Design and material
 
Chemical treatment is hampered by the area of stagnant water, and it allows the Legionella to flourish.

Prevention- The cooling tower needs to be designed in such a way that cleaning and maintenance is easy and the build-up of deposits can be prevented.

For maintaining your cooling towers along with Legionnaires prevention, you need to follow the Legionella Regulations, which you can check on website by HydroChem.