Avoiding troubled waters – Legionella control
Water is essential in so many aspects of life. We need safe water supplies at home, at work, and at school; and also in care homes, hospitals, food production, manufacturing, leisure centres, prisons, hotels and restaurants – the list is extensive. Almost every domestic or commercial setting or activity involves the use of water at some stage. We should, therefore, be acutely aware of the importance of clean water, and especially of keeping it free of Legionella bacteria.
Under the provisions of the Health and Safety at Work Act, building owners and managers have a legal responsibility to control Legionella bacteria and to prevent outbreaks of Legionnaire’s Disease, the debilitating ‘flu-like illness which has a 12% mortality rate in a community setting and an alarming 35% mortality rate in Healthcare, particularly among the very young, the elderly and those with underlying health issues.
Building owners also have a duty of care towards the wider public who may use their premises. If there were to be a Legionella outbreak, the Duty Holder and designated Responsible Person would be required to demonstrate that they were not negligent. Should negligence be proved, both the organisation and the individuals can be prosecuted and a conviction can result in limitless fines and a possible custodial sentence. This is especially true of NHS Trusts, some of whom, have in the past suffered outbreaks of Legionella and incurred huge fines, most often due to Legionella being found in equipment such as cooling towers or poorly maintained domestic water systems.
It is essential therefore to demonstrate compliance with the Approved Code of Practice for the control of Legionella (ACOP L8), issued by the UK’s Health & Safety Executive. The first step is to ensure that there is an up-to-date Legionella risk assessment for each individual premises. This should be updated whenever there is a significant change, either to the water system or to the people managing it. Therefore, if for example, a water outlet is added or removed, or the facilities manager changes, or a new facilities management provider is appointed, the Legionella risk assessment should be updated.
As Legionella thrives in tepid or warm, static water, it is essential to ensure that the water system itself allows water to flow freely around the entire system. This is not always the case where alterations have occurred and sometimes, capped off areas of pipework known as ‘dead-legs’ may exist. Dead legs allow water to remain static in sections of pipework creating a risk for Legionella proliferation; so they should be removed immediately and the risk assessment updated accordingly. It is also essential to protect cold water from solar gain and a rise in temperature. This is a particular problem with rooftop water tanks, which should be well insulated to prevent cold water from being warmed due to heat from the sun. Water tanks should also be regularly cleaned and disinfected to ensure that the water passing through them remains clear and bacteria free.
While you can conduct your own risk assessment, you should use a specialist provider who is a member of the Legionella Control Association (LCA) to help with Legionella control. LCA certification is awarded annually and providers are required to meet a strict set of criteria, so you can be sure that you are getting expert help in complying with your legal duties as the Duty Holder or Responsible Person.
Flushing routines are also essential, especially if your premises undergo periods when they are not used or underused. This is frequently the case with educational buildings, and also occurs in some manufacturing facilities which shut for a fortnight during the summer. These breaks are the ideal time to carry out any testing or remedial work which would prove difficult when the premises are fully occupied. When reopening a building after a shut down, or following a major refurbishment, the water system should be recommissioned as if it were a new water system, being cleaned, disinfected and thoroughly flushed through before use.
Legionnaire’s Disease is contracted by breathing in minute particles of water contaminated with Legionella bacteria, so, ironically, it may often be cleaning teams who are most at risk from Legionella. Special care should, therefore, be taken when flushing systems not to create splashing or aerosols of airborne water particles. In practice, this means that a toilet should be flushed with the lid closed; shower heads should be flushed through by immersing the showerhead in a vessel filled with water before turning on the shower; and taps should be run into a plastic bag, glove or similar conduit which diverts the water away into the waste outlet without splashing.
Vigilance and ongoing water testing are vital, as the fortnight incubation period can mean that an outbreak of Legionnaire’s Disease may take hold before any first signs or symptoms are detected in those infected.
A clean, safe, well managed water system will minimise the risk of Legionella and leave you safe to answer external emergencies, rather than using valuable resources to fight an internal water-borne menace.
