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Advice for Dental Surgeries on Managing Waterbourne Pathogens During Covid 19

This guidance is aimed at independent primary care dental providers as well as those in primary care GP practices.  Particular attention should be given to the control of water borne pathogens in dental unit water lines and related equipment.

During COVID-19 outbreak registered managers of dental practices should ensure that:

• There is a documented Water Safety plan (WSP), developed by persons who are experienced and competent, which includes up to date asset registers, risk assessments and management plans for all water systems including the Dental Unit Water Lines (DUWL). These should be reviewed and updated to reflect the current status of each of these systems and associated equipment during the COVID-19 pandemic
• Recommendations of the written scheme and risk assessment are implemented for the control of Legionella within the dental waterline system before during and after shutdown during COVID-19
• That all water systems and equipment that use water are reviewed for safe decommissioning and recommissioning
• Regular flushing or treatment programmes based on equipment and manufacturer’s guidance are planned
• That there is a plan to recommissioning of all water services including disinfection, flushing and validation and which ensures enough time is planned for recommissioning in advance of
recommencing services
• Actions are documented during the decommissioning and recommissioning phases (this can be done by annotating your existing risk assessments and dental-unit water-line (DUWL)
management plan)

Further detailed information produced by the Legionella Control Association can be downloaded here

Legionella Control during Covid-19 Outbreak

For all of us in the UK and around the world Coronavirus is greatly affecting all aspects of our lives, from our health, to our work, to our families and how we operate in our day to day lives.

First and foremost, it is essential that everyone’s focus and efforts are actioned towards minimising spreading the infection to keep people safe in accordance with the latest advice from the Government and the NHS. Whilst this is of the utmost priority we need to make sure that we do not lose sight of other significant threats to our health in the workplace.

Legionella bacteria and Legionnaires’ disease is one possible threat that needs to be addressed and considered in these changing times.

We are reviewing the situation and guidance we are giving to clients on a regular basis and also consulting with external bodies such at the Legionella Control Association.

The following information is based on guidance from the Legionella Control Association 23rd March 2020 and is important information for Duty holders during the COVID-19 outbreak.

What the expectation is for management of water systems during this period of COVID-19 precautions? 

The Health and Safety at Work Act still applies and Dutyholders must be taking reasonably practicable steps to control risk from legionella throughout this time.  Dutyholders implicated in an outbreak of Legionnaires’ disease resulting from actions taken for COVID-19 precautions are not likely to have any exemption from prosecution.

The LCA cannot make sweeping statements about what is critical, what can be deferred for a few weeks and what can be deferred for longer.  The legal responsibility for legionella control lies with the Dutyholder, but LCA members should be providing expert advice to their customers to assist them in compliance.  Each Dutyholder must make their own determination for each circumstance.

What principles should be considered when making decisions on what to do to control legionella during the COVID-19 outbreak?

1) The expectation for evaporative cooling systems is that they will be maintained as usual or switched off safely – there is no leeway in this

2) The expectation for water systems supplying critical services, for example hospitals, is that they will be maintained as usual – there is no leeway in this

3) Hot and cold water systems in buildings that are empty or with under occupancy must address the issue of stagnation:

a. If the building is still partially in use take additional measures to keep the remaining occupants safe:

i. If possible, drop stored water levels in tanks to maintain <24 hours storage

ii. Flush to simulate use – weekly flushing may not be sufficient

iii. Monitor temperature to ensure thermal gain in cold water is controlled

iv. If fitted, consider temporarily increasing levels of potable water treatment dosing – consider other consequences of this such as corrosion and make the decision on balance of benefit

v. If controls are lost (temperature, biocide levels, etc.) the guidance in HSG274 is to sample for legionella weekly

vi. Consider other short term measures to keep remaining occupants safe such as point of use filters at designated locations with other areas shut off

What if a building is temporarily shut down (mothballed)?

b. Buildings that are temporarily shut down (mothballed) should follow the guidance in HSG274 Part 2 paragraphs 2.50-2.52:

i. Do not drain down pipework

ii. If possible, remove sources of heat and external thermal gain

iii. Lock off, place signage on doors and otherwise advise potential users that the system has been taken out of use

iv. Have a plan in place for recommissioning the water system

For all of the work above there should be a task risk assessment in place to ensure operatives are working safely.

Recommissioning Water Systems

It is essential that when buildings reopen following the lifting of COVID-19 restrictions, that any water system is not simply put straight back into use.   During the period of shutdown it would be sensible for duty holders to formulate a recommissioning plan for each water system to allow safe start-up and assurance to users that it is safe.

Evaporative cooling systems should already have robust start-up and shut-down procedures in place and the expectation is that these will be followed.

The minimum expectation for small, simple hot and cold water systems would be flushing through with fresh mains water.  Larger buildings, those with tanks, showers, calorifiers and more complex pipework the expectation is likely to be for more extensive flushing followed by cleaning and disinfection.

Where buildings have been empty for some time and during warm weather, it is likely that some increase in bacteria levels and biofilm will occur.  These water systems may require more than a simple disinfection at 50ppm of chlorine for an hour to be successful.  The duty holder should be prepared for the need to repeat some disinfections to achieve success.

In all cases where systems are being recommissioned it is sensible to have evidence to prove/reassure that the recommissioning process has been effective.  Sampling to BS7592 should be considered for recommissioning plans to validate the effectiveness of the process.

While each individual water system is likely to need individual consideration, it will be helpful to be aware of the bigger picture with regard to demand on services.  There will be an increased demand for flushing and disinfection, sampling and other system recommissioning work.

There is potential for multiple outbreaks of Legionnaires’ disease following the COVID-19 outbreak if actions taken now are not carefully considered.  

How can a person contract Legionnaires’ disease?

Legionnaires’ disease can be contracted when contained water droplets enter a person’s lungs. People can be infected with Legionella while washing their hands, showering and bathing in a whirlpool.

Legionella can be found in many different types of water systems. All employers, building owners and landlords have a duty of care and a legal obligation to undertake a Water and Legionella Risk on all workplace buildings where there is a foreseeable risk of exposure to Legionella bacteria.

A Legionella Risk Assessment ensure properties are safe from the bacteria. To book yours now – please visit

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What are the legal requirements for GP’s regarding Legionella control?

Health and safety law require GP practices to carry out a legionella risk assessment to identify where the risk of legionella could be in their premises.  Records of risk assessments and routine monitoring tasks should be retained for inspection if requested by Care Quality Commission (CQC) or Health and Safety Executive (HSE).

Our Professional and friendly team have provided several GP surgeries, practices, private clinics and medical centres with Legionella Risk Assessments.

Want to arrange a Legionella Risk Assessment for your Medical Practice or GP surgery?

Fill out our simple call back form and one of our team will contact you to discuss your requirement and provide a quote.

If I am not storing hot or cold water in my system, do I need to carry out a Risk Assessment?

Yes, there may be other factors within your system that increase the risks of Legionellosis, e.g. dead legs, showerheads and/or long runs of pipework containing warm water. A Legionella Risk Assessment also considers the people who could be potentially exposed to any Legionella bacteria in your system, as well as any particular groups that are at a higher risk of contracting Legionellosis’.

If you would like free no-obligation advice, feel free to drop me a LinkedIn message and I will be able to assist you.

How did Legionnaires start?

Legionnaires‘ disease acquired its name in 1976 after an outbreak of pneumonia occurred among people attending the American Legion convention at the Bellevue-Stratford Hotel in Philadelphia. Later, the bacterium causing the illness was named Legionella pneumophila.

Legionella- who is at risk

Most people catch Legionnaires‘ disease by inhaling the bacteria from water or soil. Older adults, smokers and people with weakened immune systems are particularly susceptible to Legionnaires‘ disease.

Where legionella is usually found

The bacterium Legionella pneumophila and related bacteria are common in natural water sources such as rivers, lakes and reservoirs, but usually in low numbers. They may also be found in purpose-built water systems such as cooling towers, evaporative condensers, hot and cold water systems and spa pools.

Hot Tub & Spa Pool Legionella Compliance

Spa-pool systems are a recognised source of legionnaires’ disease, primarily Legionella pneumpohila. There have been a number of outbreaks linked to spa pools in leisure centres, hotels, holiday homes, on cruise ships and on display. 

As such, if you maintain a spa pool or hot tub of any description you have a moral duty of care and in commercial organisations, a legal responsibility, to ensure these facilities comply with guidance set out by Health & Safety Executive (HSE).

If you require further assistance regarding a Legionella risk assessment or have questions relating to your responsibilities around spa-pools e.g. testing regimes etc call us now on 0808 1080 766, complete our simple call back form or Click here to email and one of our team will contact you to discuss your requirement and provide a quote.