Legionella
These bacteria, which thrive in warm water from 24°C up to 52°C in our plumbing system, should not be given the opportunity to become a serious problem.
From time to time, usage habits in homes change over the years, the internal resistance in the pipes increases, system components malfunction unnoticed, system settings are inappropriate... there are single reasons or many causes that combine, and then these heat-loving bacteria become an issue.
Just as bacteria in cold water can multiply to harmful concentrations under favorable conditions, Legionella is also not entirely harmless at elevated concentrations. However, the danger concerns a different area of use. While you shouldn't drink heavily contaminated cold water because you could quickly get an intestinal infection, you can drink water rich in Legionella, but not inhale it. This isn't usually possible either – at least, we don't usually breathe underwater. But as an aerosol (fine vapor/mist), for example, in a shower, it can be released into the air. For example, while showering, you can expose yourself to the bacteria and potentially become infected without even realizing it. Immuno-compromised people are naturally affected first – as always. People with strong immune systems often have no problems, even when concentrations exceed four-digit levels. Sick people, elderly people, especially in nursing homes, asthmatics, heavy smokers, etc. are particularly at risk of contracting Pontiac fever or pneumonia caused by Legionella – Legionellosis. However, even regular people can occasionally get a flu-like infection, and if Legionella then attacks the immune system, it is of course not a necessary, unavoidable problem but should be prevented.
Legionella only multiplies if the hot water supply system is faulty. Water must flow, be replaced regularly, and the temperature must not be too low for hot water or too high for cold water over an extended period. This sounds simple, but it's not always so easy to implement technically, and that's why we're here.
Since our knowledge of Legionella and its mechanism of infection is still not well known, we need to constantly update ourselves to stay up to date, to assess the risk potential as accurately as possible, and to coordinate appropriate measures. Of course, you don't have to. But here's a very good website with general information, which I can also recommend to you, from the LGL:
https://www.lgl.bayern.de/gesundheit/arbeitsplatz_umwelt/biologische_umweltfaktoren/infektionsgefaehrdung.htm
Preliminary Examination
To identify system faults, annual (or every three years) preliminary examinations – sampling – are required. These are carried out by individuals authorized to perform certified sampling. The sampling points, which can be used to check the entire hot water system, are also called representative sampling points. These should ideally be determined by someone who has already inspected the building or has the pipe layout – ideally both.
The procedure, i.e., the method by which a sample is taken, is standardized. Deviations from this are only permitted during the preliminary examination if, for example, the exact volume of the individual pipe supply to the final point of use is known. Further details are available by phone.
Further Investigation
If Legionella contamination is confirmed in the system, further investigation is advisable. Depending on the level of contamination, this should be done either immediately or within one year.
If the technical measure value is exceeded, we strongly recommend contacting the expert who is to conduct the risk analysis directly, before conducting further investigations. In the case of health-threatening contamination, the expert will come immediately and clarify which sampling methods should be used at which sampling points, or carry out the sampling themselves. Not every company that offers certified sampling is also able to determine the methods and important final sampling points where further sampling is sensible and effective. This way, unnecessary costs can be avoided. The money is better invested in the measures that need to be implemented to get the system back on track.
Risk Analysis
A risk analysis clarifies and describes in a way that is understandable for all involved, ideally with photos and diagrams, how the system is constructed, functions, and operated.
The condition of all relevant components and the measurement data recorded must then be specified. For this purpose, the collected values, sampling results, and measurement results must be presented not only in tabular form but also graphically, if necessary. Important boundary conditions for the collection of measurement results must also be listed.
Correlations between the sampling results, temperature profiles, usage overviews, pipe dimensions, hydraulic conditions, and other system errors or peculiarities must be identified and presented.
The next step is the evaluation and assessment of the results. In this context, reference is made to any worksheets, DIN standards, recommendations from the Federal Environment Agency, etc., that were considered in the assessment. The hazard potential is then assessed. The necessary measures are then listed in detail and set within a timeframe to get the system up and running again. The control measures are logically presented clearly along with the repair or modification measures in the correct chronological order. If there are different approaches to a solution, this will of course be mentioned, discussed in detail with the client, and the preferred solution will be detailed. The risk analysis is easy to understand for all involved and is detailed in the key points. It should enable the system operator to identify the hazard and implement the measures in a targeted and timely manner – independent of a specific company. The operator must be able to take this risk analysis to any i.e. plumber, who can prepare an offer based on it. The health department, in turn, must be able to assess the risk & hazard potential based on the risk analysis.
Follow-up Inspection / Control Inspection
The risk analysis specifies the correct date for the follow-up inspection, which verifies the successful resolution of malfunctions in a hot water system.
A control inspection is a structured sampling after a specific section of the required measures are implemented. It may be the case that some potential system errors are masked by currently more serious errors. A specific number of measures are then proposed, followed by a control inspection. If this does not meet the desired result, the other measures listed are implemented. This is followed by another control inspection. This can take several "rounds." If the control inspection yields a positive result, this also constitutes the follow-up inspection. The sampling points are specified in the Risk Analysis. This structure helps to minimize the risk of unsuccessful big follow-up inspections and usually reduces the costs significantly.