Whether you own a building with a cooling tower or are simply responsible for the maintenance of a tower at a facility, Legionella prevention is likely high on the list of goals that your regular routine aims for. However, Legionella is a challenging bacteria to overcome, and it is important that you perform regular sampling, typically at least, to understand whether your water system has become compromised before anyone falls ill due to an outbreak.
What Is Legionella?
Legionella is a bacteria that is commonly found in cooling towers that are not properly maintained. It can thrive in any fresh water that is between 77 and 108 degrees Fahrenheit, and it is transmitted to humans by vapor or water droplets in the air. These enter through the nose or mouth and can cause Pontiac fever, a flu-like illness that can be dangerous to the same groups of people for whom the seasonal flu is a threat. Legionella also causes Legionnaires’ disease, a much more deadly sickness that quickly creates a chain reaction of lung inflammation that can lead to fatalities in as many as 10% of those who fall ill.
Cooling towers are one of the most prolific spreaders of Legionella due to the mist that is created during their regular operation. For this reason, consistent Legionella sampling on cooling towers is critical and even standard in order to comply with local and state regulations.
The Steps of a Legionella Sampling Routine
Legionella sampling should be done regularly, especially if there is any reason to believe that Legionella may have begun to proliferate in the water system. Remember that Legionella is a dangerous bacteria; work with testing experts, and wear personal protective equipment while conducting any sampling. Turn fans off to prevent the spread of water droplets, and ensure that any masks worn are equipped with an N95 filter.
Acquire Water Samples
The first step in Legionella sampling is to acquire water samples. The best locations to sample the water will depend upon the unique structure and layout of your cooling tower system; be sure to ask an expert in order to identify the ideal sites. Collect as much water as possible from the cooling tower basin. 200 ml to one liter is ideal. A normal tablet is normally added to the sample, which will remove chlorine or halogen material in the water that may interfere with the results. Tightly close the container, and place it into a cooler so that it can be transported to be tested within 48 hours.
Document Water Quality Parameters
Next, you will need to document the parameters under which the cooling tower is operating. This includes taking the water temperature, which will serve as valuable information to establish the possibility of Legionella growth within the system. Include measurements of chlorine content in your documentation, and take the time to evaluate the pH level of the water as well. Water pH testing strips are sufficient, but digital pH meters also work well.
Sample the Biofilm
It is also important that you sample the biofilm within the cooling tower if you see it. This is a normally sticky substance collected on moist surfaces, and you can use a swab to firmly rub against the surface and grab the film. Collect a small amount of water from the same location to keep the tip of the swab moist while it is moved to the testing location. Once the swab is in the tube, be sure to break off the stem to prevent damage and ensure that the tube can be tightly closed. A drop of normal sodium thiosulfate solution should be added to neutralize contaminants that could interfere with the results. It is wise to take a number of samples from a variety of locations and label them accordingly. Legionella may be present in one area of a system or in the biofilm of a certain piece of equipment but has not yet spread elsewhere.
Work with Legionella Treatment Experts On Legionella Sampling
The process of Legionella sampling in a cooling tower should be comprehensive and involves careful work to receive accurate results. The best way to ensure that your cooling tower is safe is to rely on a Legionella treatment professional to perform the sampling. They can evaluate the risks unique to your system and recommend important areas to test or repair. Tower Water would be happy to perform Legionella sampling so that you do not have to worry about the dangers of Legionella exposure, personal protective equipment, and unreliable results due to insufficient sampling. Reach out to schedule an appointment with an experienced technician who can perform sampling on a range of surfaces and locations within your cooling tower system.