Legionella monitoring

With at least 300 cases in the UK last year and fines in excess of £700,000 being issued to organisations, control of Legionella has been forced to the forefront of our minds. The introduction of strict government guidelines (L8) has triggered us to step back and re-consider how we are currently controlling this deadly disease. We are beginning to investigate whether we are doing enough, both to protect ourselves and those in our care.

Potentially fatal
Legionnaires' disease is a potentially fatal form of pneumonia which can affect anybody, but which principally affects those who are susceptible because of age, illness, immunosuppression and smoking. The most susceptible groups of people are males, adults over 45, smokers, alcoholics, diabetics and those with cancer or chronic respiratory or kidney disease.
    
It is caused by the bacterium Legionella pneumophila and related bacteria that grow when certain conditions are present, particularly in water systems. Particle spray from taps or water-cooling tanks are a common source of infection, attacking victims who breathe in the particles, which find their way deep into the lungs.
    
Legionella may be, and often is, present within a water system but is not dangerous unless the conditions support its growth. Therefore it is vital that these conditions are accurately monitored. Its prevention is your responsibility.

Your responsibility
By ensuring that water temperatures are kept outside of prime growth temperatures (20-50°C) facilities managers can ensure Legionella does not fester and grow within their system. Usual practice is to take temperature readings manually to ensure that this does not happen.
    
Recent doubts over how accurate, and therefore safe, this is have, however, called for a new measurement and monitoring system. As the age of manual data monitoring draws to a close, the benefits of more accurate systems are being exploited. An ideal system is one that automatically and consistently takes readings over a regular time period and sends this information to the person responsible for its monitoring.

Common misconceptions
Poorly advised monitoring or inaccuracies in data collection can be fatal. There are many misconceptions in the field of Legionella monitoring causing both dangers to human lives and costs from government issued fines. Partial knowledge can be as dangerous as no knowledge when dealing with Legionella. A common misconception among those monitoring is that a Legionella monitoring system is not necessary if a Thermostatic Mixing Valve (TMV) is in place. This is not the case.
    
The truth is, although it can appear to aid your Legionella control, the TMV is not designed for this purpose and so is ineffective. TMVs were originally designed to prevent scolding at the outlet when hot water systems distribute water at very high temperatures. Distributing the hot water at high temperatures (in excess of 60˚C) will eliminate Legionella, but once this water has passed through a TMV risks increase as it mixes with the cold supply especially on infrequently used outlets. Should the cold water supply be the source of contamination you could have a potential outbreak. Additionally, should there be a fault in the hot water the risk of contamination is increased if and when it is distributed at lower temperatures.
   
Even with TMV’s in place you should still monitor the temperature of your water system. The approved code of practice states that regular monitoring of both hot and cold water temperatures should be carried out on the input to TMV’s on a sentinel basis, monitoring the temperature control regime.
 
Action
Full government guidelines of the do’s and don’ts of Legionella Monitoring can be found in ‘The control of legionella bacteria in water systems Approved Code of Practice & Guidance L8’. It is vital that these guidelines are properly understood in order that defences are built high in the battle against Legionella outbreaks.
    
In producing these guidelines the government has made us responsible and we must act on the information we have. If you are unsure about whether you have taken the necessary steps to prevent a fatal Legionella outbreak in your building, contact a reputable Legionella specialist or monitoring system supplier for more information. Whatever you do, don’t wait for an outbreak to prompt you.
     
Act now. Reduce costs, save lives, monitor for Legionella.