Tips for Keeping Your Water Systems Safe
BEAMA’s Water Safety & Hygiene Group recommends keeping water systems healthy by managing biofilm.
Around 99.5% of the bacteria found in taps, pipework and mixers are in a biofilm, providing a perfect environment for them to thrive. Biofilm is a collection of micro-organisms that stick to an appropriate surface and secrete an adhesive and protective matrix. Biofilm naturally forms in water, on any surface, and can occur systematically after a few weeks or months in water systems.
In hot and cold water systems, a fundamental measure for controlling the risk of Legionella growth is to restrict the formation of biofilm by avoiding water stagnation. Important measures also include avoiding the use of materials that may encourage bacterial growth and avoiding temperatures between 20-45 Degrees Celsius, which favour bacterial development.
Aggregates can form when the bacteria multiplies if it is left untreated, especially in stagnant water. The aggregates can naturally be detached and contaminate the water system or it can be maintenance that dislodges them. If the biofilm is destabilized, such as by thermal treatments recommended to control Legionella by the Health & Safety Executive, pathogens like Pseudomonas aeruginosa can be released into system.
It is therefore important that systems should be flushed and monitored regularly so that bacteria can be prevented from establishing in the biofilm. Unfortunately, the safe mixed water temperature for showers, bathing and basins is between 20-40 degrees Celsius, which coincides with the temperature range at which Legionella is most likely to develop, particularly in pipework dead legs or stagnant water. Places where occupancy rates fluctuate, such as Hospitals, Schools and Hotels, can be the most at risk due to periods of inactivity.
Biofilm can be managed at system level by instigating a daily duty flush which will avoid stagnation in pipes supplying faucets which only have flowing water when the faucet is used, or by removing pipe runs (dead legs) that no longer have water running through them. This can be achieved manually if there is an electric shower or tap at the end of a pipe run with an daily duty flush activated.
The water outlet can be managed to prevent the development of biofilm as the interior surface of the outlets effects how easily the bacteria can adhere. Old taps and mixers had relatively rough surfaces but modern mixers and taps have a smoother internal surface which bacteria cannot adhere to as easily, which therefore slows the development of biofilm and bacteria. Some of the newest models can even be removed for regular cleaning, and by removing scale deposits, biofilm build-up will be reduced and so will the risk of contamination by Pseudomonas aeruginosa.
It can be very difficult to eradicate pathogen-harboring biolfilm, but with effective system management it is possible to reduce the risk of contamination.
LRA control and solutions
All you need to do in the first instance is to contact our expert service team on [icon name=”phone”][tracker-local-phone] and discuss your needs and arrange for an initial free survey of your building. This will enable us to provide a cost to carry out an annual Legionella Risk Assessment for you. The LRA will then document and suggest recommended preventative measures to make your water systems safe.