First aid to avoid legionella growth!
First aid to avoid legionella growth!
Although clear preventive measures have been taken by the Belgian government since the Legionella outbreak in 1999, the bacteria continues to appear in our country from time to time. Wet cooling towers represent a real risk. Nevertheless, we can prevent contamination thanks to sufficient maintenance and the right water treatment.
What is legionella?
Legionella is a bacterium that can cause legionellosis or pontiac fever. Both diseases occur through the inhalation of water mist infected with the bacterium. Legionellosis has the most powerful symptoms, a chronic lung disease that can have dangerous or even fatal consequences. This condition is better known as legionnaires’ disease, named after the famous epidemic during a reunion of an American legion of veterans from the Vietnam War.
The legionella bacterium can manifest itself in different places. Areas with poorly maintained water systems are particularly at risk. Wet cooling towers are a major risk group. Drinking water contaminated by the bacteria is not harmful. Only when you breathe in contaminated water mist, you run the risk of becoming ill. Legionella bacteria can spread through the air up to a distance of 10 kilometres via this water mist! This way, the entire environment may be at risk of contamination. This also means that tracing the source is not easy.
Legionella decree 2007
Since the serious outbreak in 1999, the Belgian government has been working on a concrete prevention plan. In May 2007, the new Legionella Decree was ratified by the Flemish Government. There are stricter requirements for water installations in public places and there is also a reporting obligation. In order to prevent legionnaires' disease, all possible risk locations must draw up a management plan on behalf of the government. This includes an extensive risk analysis with regard to legionella formation in the water supply. The Decree also states that cooling towers must be built and operated in accordance with the Best Available Techniques (which are described in a European BAT study). In addition, suppliers must also issue a certificate of conformity for carrying out work or maintenance and for the components supplied, which confirms that work and components comply with the BAT study and therefore with the legislation. Almeco has been working according to this BAT study for a long time and has all the necessary certificates of conformity.
Danger of cooling towers
Cooling towers are used to cool a building or an industrial process by spraying water that spreads like a light mist. Let that also be the way in which legionella bacteria spread. It is therefore very important to take all possible measures to prevent this from happening.
When exactly is your cooling tower a danger? The following features are very conducive to the development of legionella:
• Temperatures between 25 and 50 °C
• Formation of a biological contamination
• Formation of inorganic deposits
• Zones with corrosion
• Areas with stagnating or prolonged stagnant water
In addition, a cooling tower in poor condition is up to 50 times more likely to cause contamination than a well-maintained installation. Optimal maintenance of your cooling tower and control of the above features is therefore crucial!
Legionella-free cooling tower
Among other things, Almeco installs new cooling towers. The range includes a 100% legionella-free cooling tower. Our AIR-A is an adiabatic cooling tower where aerosol formation is not possible. There is therefore a 0% risk of the formation of legionella bacteria.
If you still have a cooling tower that is susceptible to the bacteria, it is very important to take the necessary measures. Almeco and PCA will assist you at every stage.
PCA already has experience in drawing up management plans on behalf of the customer for all locations where a wet cooling tower is present. You can also count on our service for the complete follow-up of your cooling towers. We regularly take and test samples of the cooling water according to the applicable methods. The samples are examined for hardness, chlorides, iron, pH and conductivity. A recognised laboratory checks the samples for legionella. On the basis of these results, we give advice on the necessary measures to combat legionella and to obtain and maintain the optimum water quality. We have a wide range of chemicals and instrumentation at our disposal, which enables us to offer you various possible solutions.
In addition to monitoring the cooling water, the cooling tower itself also requires the necessary maintenance. Almeco has 45 years of experience in the maintenance of cooling towers.