Legionella Bacteria Risk Assessment: Things You Need to Know

Are you wondering if you are legally bound to test your hot and cold water systems for Legionella bacteria? Precisely speaking, you are not bound to go for the risk assessment unless there’s a specific need.

But, you should not test your water for Legionella bacteria just for the sake of law.

The Legionella testing is similar to wearing a helmet while driving two-wheeler; it is for your own safety. About 5000 cases of Legionnaires’ disease are recorded annually in the United States. And, one out of every ten Legionnaires’ disease patients dies due to the illness. Hope this statistic is sufficient for you to understand the importance of testing your water systems for the Legionella bacteria.  

How often should you test your water system for Legionella bacteria?

The cooling towers are at higher risk of the bacteria so they need regular testing. This regular testing means assessment at a minimum three months interval unless there are some signs of a problem. If there’s any doubt in the test findings or the prevention procedures are not being carried out properly, the weekly assessment might be needed. Once the test result shows the water to be safe, monthly testing should be done over a short period.

In addition to Legionella bacteria, cooling tower water and make-up water should also be tested for microbial activities.  

From what points should you collect samples for the assessment?

You must know that testing water sample from one point is never sufficient for assessing the level of Legionella bacteria. Not only you need to take water samples from various points, but, you need to take the sample from the higher risk areas.

Water samples from various taps and outlets may show the level of Legionella to be within the safe limits. But, the water samples taken from the water tanks may give a completely different picture. The points where water temperature drop-out of the specification or the points where water sits stagnant in pipes and tanks should be given more consideration as they are higher risk zones. Once the points for water sampling have been decided, you should keep a note of them. Taking samples from the same point for each turn of testing gives clearer picture due to consistency. You can visit the website for getting more information on the matter.     

Should you hire experts for sampling and testing water?

Well, there are testing kits available on the market that lets you test water from your water system on your own. But, it is always best to get your water sampled by competent persons and getting it tested in accredited laboratories. Inferring the test result is not a work that any untrained person can do effectively. If you want to do the sampling on your own, it would be good to undergo appropriate training.

Whatever way you choose, you should make sure that your approach to Legionella testing is focused more towards keeping your water system safe rather than simply fulfilling the legal requirements.