Locked down buildings need more than flushing to ensure water quality

20th May 2020

Sky News have reported that ‘Businesses told to flush out water supply before reopening to avoid potentially deadly Legionella bacteria’.

Toby Hunt from Guardian Water Treatment is urging responsible parties to proceed with caution when it comes to this task.

The article from 20th May detailed guidance by Public Health England (PHE) for the ‘regular flushing’ of water systems. Dental practices, hairdressers, gyms, hotels and office buildings are all impacted by the guidance.

“Our evidence shows that flushing buildings alone during periods of inactivity may not resolve potential water quality issues. While it could serve to reduce Legionella bacteria, overall microbiological control is likely to be compromised,” said Toby.

“Nearly half of the buildings sampled in the last four weeks have significantly increased TVC results. This is in comparison to 24% in the same period last year. As the weather gets warmer, these rates, which potentially show that the water is not safe to use, are likely to increase.

“Flushing is still important, however other measures may be required to ensure control of bacteria in these water systems. We recommend that supplementary microbiological samples should be taken to prove regimes are effective, other actions implemented if required.”

The right approach

While flushing of outlets is essential – it’s key to preventing stagnation – this process should form part of a holistic approach to legionella prevention and water treatment. All work should be tailored to the fact that a building has been unused.

Daily and weekly testing and associated tasks must be maintained, and in some cases increased. The Legionella Control Association advises against reopening a building that has stood idle without addressing the safety of its water systems. This is unacceptable and likely to be in breach of the law.

Legionella is not the only issue. Drinking water may no longer be potable during a long period of stagnation, which could also lead to delays in buildings reopening.

The article in Sky News notes that “premises are also required to undertake a detailed review of all aspects of their water management system before reopening amid the continuing coronavirus lockdown,” and that “…all aspects of the water management system need to be reviewed before reopening the business, and necessary action will be dependent on the complexities of the system.”

“This last point is important. Every system and its’ usage is different and should be treated accordingly. If we do not recommission buildings safely, public health will be compromised,” concluded Toby.

Responsible parties should refer to the Legionella Control Associations (LCAs) guidance at www.legionellacontrol.org.uk.

For more information about Guardian’s Legionella Control Services, click here.