Water safety has been in the news recently with outbreaks of legionella, a bacteria commonly found in water, in New York. A cooling tower in a South Bronx hotel was identified as the source of the deadly Legionnaires' disease outbreak, which claimed the lives of 12 people.
Closer to home, the 12th Annual Combating Legionella & Water Treatment conference took place in Birmingham last month. Speakers from a wide range of sectors discussed what can be done to minimise the risk of legionella through structured risk assessment. It is estimated that there are between 200-250 reported cases of Legionnaires’ disease each year in the UK.
Infection by legionella bacteria causes Legionnaires’ disease which is a potentially fatal form of pneumonia and typically affects men more than women. It is not contagious but it can be fatal.
Water systems must be maintained in a good condition in order to minimise the amount of bacteria present and to avoid multiplication. Organisations should carry out a full risk assessment of their hot and cold water systems and ensure adequate measures are in place to control the risks.
3 tips for ensuring safe water
- Temperature control
We can pinpoint the environment in which legionella thrives, which is at temperatures between 20-45 degrees centigrade. If the temperature is below 20 degrees centigrade the bacteria is dormant, therefore guidelines recommend cold water should be delivered to the tap at below 20C. Hot water storage systems should supply water at 60 degrees centigrade or more at all times.
- Stagnant Water
Legionella will grow where water is allowed to stand unused and is warmed up to above 20C. Stagnation is most likely to occur where services have been removed but the pipe work has been left in place (deadends); where water services are infrequently used (deadlegs) or where too much water is stored (large water tanks). These conditions should be identified in a formal risk assessment, and once identified, should be removed, or action taken to control legionella growth e.g. dead ends should be removed or cold water storage tanks cleaned.
- Monitoring and testing
It’s important that the person responsible for maintaining the water systems has had sufficient legionella training to be able to regularly check, clean and inspect the systems. Particular attention needs to be paid to the sentinel outlets (the outlets which are both closest and furthest from the mains water entry point or storage tank) and the temperature at which water is distributed should be monitored. Water samples should be taken and analysed annually, or as defined during the risk assessment. This is particularly important for high risk water sources, such as stagnant water.
If you suspect that your water is infected with legionella or you are unsure about the risks, it’s important to act fast. Cases of legionella result in a full investigation along with prosecutions for any failures in health and safety procedures.
The events of the last few months in the US have reminded us of the importance of legionella compliance, safe water supplies and full awareness of the risks involved.
For further information on Brodex’s legionella risk assessment services or contact our team here.
