Summer checklist for Legionella control

Statistics show that summer is a peak time for Legionnaires’ disease infections, so particular attention needs to be paid to Legionella control during the period.  One of the reasons for higher infection rates is that some risks are increased during hot weather, and there are also other factors which raise the likelihood of Legionella proliferation.

Here are our top three tips for keeping on top of Legionella risk control this summer:

1. Control water temperatures

It has been particularly noticeable during the heatwave that the ambient temperature of mains water is warmer than normal. Legionella bacteria thrives at between 20°C and 45°C, so when the outside air temperature is in the high twenties or more for days at a time, the likelihood of stored water rising to within the ‘danger zone’ is greatly increased.

For this reason, the monitoring and controlling of water temperatures is of paramount importance. All efforts should be taken to keep cold water cool and similarly, hot water needs to be kept hot (above 60°C) to avoid bacterial proliferation.

Check the temperature of both hot and cold water regularly (ideally weekly) and record your findings. Lagging on tanks and pipes can be used to help regulate temperatures if necessary.

2. Keep water moving

Stagnation is another key factor in Legionella growth. Many buildings – whether homes or workplaces – can see a drop in water usage as people go away on holiday. If water isn’t kept moving from running taps, flushing toilets and using showers, it may gather in the nether regions of the plumbing system and bacteria or biofilm will grow.

To prevent stagnation when a building is left empty or outlets are unused for a week or more, a flushing routine should be undertaken. This means running taps and showers for five minutes per week and it’s important to keep up the practice; as illustrated in this chart, starting and then stopping flushing actually increases the risk of Legionella. You can find more advice on flushing in this blog post.

Legionella control with flushing

3. Cover staff absences adequately

Holiday time can also play havoc with staff rotas and responsibilities for Legionella control. In many court cases related to non-compliance, absence of key employees or lack of training among staff members is cited as the cause of lapses in water hygiene routines, often with devastating consequences. Accurate record keeping can also be affected if cover staff aren’t properly briefed.

Whether organising holiday cover, covering for unexpected sick leave or dealing with other staff shortages, it’s vital to have properly trained personnel available to take on Legionella control responsibilities. You must also ensure that all maintenance and monitoring tasks are kept up as required, and recorded accurately.

If you need professional help with any aspect of water hygiene now or at any time of the year, we can help. Whether for a temporary or one-off task, or for ongoing assistance, visit the services section of our website or contact us.