The current version of the ACoP L8 was published in 2000 as joint Approved Code of Practice (Part 1) and Technical Guidance (Part 2). It has proven to be one the most popular documents the HSE has produced. It has been reviewed following Lord Young’s report on compensation culture in the UK and Professor Löfstedt’s review of Health & Safety Law in the UK which started in 2011. The review of the ACoP was undertaken through 2013 and the revised version 4 of the ACoP and the Technical Guidance documents were published on the 25th November 2013. The previous version has now been withdrawn. The revision of L8 means that the document is now in two parts and gives a clearer distinction between legal requirements and guidance:
Firstly it is important to clarify this is a review and not a re-write and that those already complying with the law do not need to change what they are doing. The fundamentals of Legionella management and control remain the same:
The ACoP still carries special legal status.
In conclusion the new ACoP is more detailed and but also more concise and easier to read and understand. There is a greater emphasis on the role of the Duty Holder and the importance of training, review of control measures, communication, auditing and design. The Duty Holder must lead legionella control with their premises and ensure they are complying with the law they cannot be absolved of duty.
The Technical Guidance for evaporative cooling systems is now a separate document. There are not many changes in what is required to manage and control the risk from Legionella in these systems but what is different is the clarity and how much easier it is to understand for the Duty Holder.
Currently the published document is the same as the guidance in version 3 ACoP and guidance L8. Until the new version is published no changes are required.
The revised edition is currently out for consultation and is due to be published by the end of March 2014. The guidance is very different in its look to the old guidance. Like the other guidance documents the information is clearer more concise and is easier to read.
A full review will be undertaken by ESG once it is published by the HSE in Spring 2014.
Now a full guidance which is a significant increase from the few paragraphs in the version 3 L8. The guidance now includes the following improvements/changes:
The HSE published their review of the 3rd edition ACoP Legionnaires’ disease: The control of legionella bacteria in water systems in November 2013 along with technical guidance documents HSG274 Parts 1-3. Part 2: The control of legionella bacteria in hot and cold water systems at the time was published as an interim document; the new document was published April 2014.
A long overdue review of legionella control procedures, HSG274 Part 2 aims to provide clearer and more detailed practical advice on the management and control of legionella in domestic hot and cold water systems.
Firstly it is important to note that the principals of legionella management and control remain the same: identify and assess sources of risk; prepare a written scheme for preventing or controlling the risk (if appropriate); implement, manage and monitor precautions; appoint competent person or persons to manage the risk and keep records.
The risk assessment remains the starting point for legionella control; it should be considered a living document and should be reviewed on a regular basis. The risk assessment should lead the duty holder and responsible person on how best to manage and control the risk from legionella.
The new document is 4 times larger than the previous guidance for hot and cold water systems, but does bigger mean better? We believe it does; many cases of legionnaires’ disease are attributed to domestic hot and cold water systems so it is important that everything is covered clearly and in detail. All buildings will have domestic hot and cold water systems so this document is applicable to owners, operators, contractors, designers, installers, manufacturers and anyone with or working on domestic water systems. Over the next few paragraphs each section in HSG274 Part 2 will be summarised with changes from the previous guidance highlighted.
HSG274 Part 2 provides significantly more information on types and application of hot and cold water systems. Specific reference is made to smaller low risk water systems which are typically mains fed and supplied by instant or point of use (POU) water heaters or combination boilers with a capacity of no more than15 litres, low risk users and no showers. These types of systems are becoming increasingly common as duty holders and responsible persons look to reduce the legionella risk and maintenance overheads in their properties. Paragraph 25 in L8 4th edition states that elaborate control measures may not be required in low risk systems. A risk based approach can be taken on these types of systems as to the frequency and type of control measures and monitoring. Combination water heaters (with an integral cold water tank) are also common on these types of systems, but will require more different and more frequent monitoring as discussed later.
More complex water systems with cold water tanks, calorifiers, showers and a large number of outlets are also clearly explained. Different types of calorifiers, their potential faults and benefits, such are direct gas fired units which have a lower incidence of legionella colonisation, are clearly explained. A new section refers directly to solar heated calorifiers and how they should be installed. Complex systems will require current control measures to continue but may require an increase in the tasks and frequencies required which is covered later on.
A section that has expanded considerably from the previous guidance and as always, the key is to design and commission a system that will not increase the potential for bacterial growth. Low risk systems should always be considered as the ideal option and consideration should be given to self flushing systems, such as automated sensor outlets. Installing measures to reduce water usage and improve energy efficiency need to be carefully considered to ensure legionella control is maintained. Consideration needs to be given to design guidelines for healthcare buildings and HTM04-01 should be followed. Flexible pipework with EPDM lining should not be used in healthcare domestic water systems. All components of a domestic hot and cold water system must be easily accessible.
Hot and cold water systems should always be designed to avoid encouraging legionella growth, good movement/turnover and good temperature control. Cold water temperatures still need to be below 20°C with heat gain kept to a minimum (the 2°C maximum recommended heat gain in the 3rd edition of L8 has been removed). Hot water system information has not changed significantly but more information is provided on circulating pump design and balancing the hot water system to ensure good water movement and temperature control. Storage temperatures in calorifiers still need to be at least 60°C with a minimum 50°C at outlets and on hot water returns (increased to 55°C in healthcare premises).
A significant amount of new information is provided on expansion vessel design and installation as recent research has suggested, they can become accumulated with biofilm and have been considered dead legs for some time now in risk assessments. Ideally flow through designs should be used, if not, then isolation valves and drains need to be fitted.
Commissioning of smaller installations will now only require flushing before occupation but it is important to ensure systems are wet for as shorter amount of time possible before occupation. Larger systems will require, as previously, flushing and disinfection. A flushing regime must be in place once the system is wet. All disinfection must be done as directed by BS8558:2011. Pressure testing systems should ideally be done using air if water is to be used then the system must be flushed weekly or chlorine dioxide added to the system until occupation.
There is now a section on buildings temporarily out of use. The written scheme should set out how an out of use system is to be left to minimise legionella growth. A flushing regime should be instigated and once recommissioned disinfection should be carried out.
The principles of legionella control and monitoring remain very much the same but there a number of key changes in this section which are bullet pointed below:
|
Key change |
What does it mean? |
|---|---|
|
Pictorial guide to cold water tank internal inspection. |
Useful for risk assessors and those doing monitoring as a guide to when tanks need a clean. |
|
Annual cold water storage tank temperature check in the summer |
Previously 6 monthly and freeing up resource for other new tasks. |
|
All spray outlets require quarterly or dependant on rate of fouling, cleaning and disinfecting. |
Extra work as outlets such as spray taps and spray rinses now need to be done. It may be easier to remove the spray inserts. |
|
Large and complex hot and cold water systems will require more than a nearest and furthest sentinel point temperature check. Circulating return legs and long runs will also require monthly testing from pipework or sample points. If hot water return legs are to be used then the water should reach 50 °C within 30 seconds. |
Additional monthly monitoring tasks for large complex systems, as they are higher risk. These tasks could be counteracted by less frequent monitoring of low risk systems. |
|
The risk of scalding needs to be considered in the risk assessment and monitoring. |
Not a major change but extra information provided on use and application of TMVs |
|
Where a hot tap is blended the cold tap (if separate) should be considered infrequently used and potential dead leg. |
Is the cold tap needed? Is it used? Review and remove if not required. Flush weekly if it is required and not used. |
|
Point of use and instant water heaters (those with ≤15L capacity including combination boilers) should be supplying hot water at 50-60°C. The temperature can be lower if frequently used by low risk users. All other hot water heaters need to be at 60C. |
50°C has always been the control temperature at hot outlets. Monitoring frequencies can be reduced to as little as 6 monthly. A risk based approach is required for low risk systems and should be reviewed regularly. |
|
Combination water heaters (with integral tank) should be set at 60°C with flow of 55-60°C at nearest outlet. The tank needs inspecting annually. |
Additional monitoring of the tank section required. Monthly flow temperatures required. |
|
Expansion vessel should be flushed monthly-6 monthly. |
Isolation points and drain valves are required to allow for flushing. |
|
All cold water systems require sentinel point temperature check monthly |
A change from 6 monthly incoming cold water checks |
|
Cold water insulation should be checked for integrity annually. |
An additional annual task |
|
Hot water temperatures at outlets and calorifier returns need to be at 55°C in healthcare premises. |
Many systems will achieve this but modification may be required on some systems to achieve 55°C |
|
Hollow support tubes on cold water tanks should be replaced. |
Must be identified in risk assessments and annual inspections and removed. |
|
Guidance is now given for the use and monitoring of point of use filters, water softeners, multiple use filters and TMVs. |
New guidance on frequency of monitoring if installed. TMVs should be temperature checked and inspected at least annually. |
|
There is now more detailed guidance on flushing or removal of infrequently used outlets and equipment. |
Confirming what is already done by most people. |
|
Low risk systems are defined as mains fed, POU water heaters (≤15L), no showers, good usage and low risk occupants. |
Allows for risk based legionella control and monitoring to be put in place. |
|
Electric showers are to be considered as POU water heaters. |
Temperature checks required at least 6 monthly |
|
Detailed guidance now present on the installation and use of TMVs. |
Additional advice to prevent scalding |
The risk assessment should always define the control measures that are required and a risk based approach must always be used. Smaller low risk systems with low risk occupants may require a different control regime from larger complex systems. Legionella control and monitoring regimes must continue to be reviewed on a regular basis by the responsible person.
The guidance on the use of biocide treatments as a control measure has been expanded, paying particular attention to healthcare premises where temperature control has to be used alongside biocide control measures. Chlorine has made reappearance alongside chlorine dioxide, and copper and silver ionisation; all are widely accepted as excellent biocide control measures and the guidance provides very useful detailed information on their use and the monitoring programmes required when in use. There is new additional guidance on the use of point of use filters on systems where control measures are failing. Often used in healthcare buildings they should be considered a last resort and also a temporary measure until a permanent solution is found.
There remains no requirement for regular biological monitoring of domestic hot and cold water systems that are primarily fed by mains cold water. There needs to be a risk based approach to determine whether biological monitoring is required and where on the system sampling should be carried out. The guidance references BS7592:2008 Sampling for legionella organisms in water systems to provide guidance on how, where and when legionella sampling should be undertaken. Guidance is given for interpreting sample results in healthcare and non-healthcare premises in table 2.2 and 2.3; the difference is that results up to 100cfu/l or negative results should not be ignored due to the susceptibility of the patients.
Reasons for cleaning and disinfecting hot and cold water systems are detailed making reference to specifications in BS8558:2011. The number of reasons has significantly increased from the old ACoP and includes: after positive legionella sample results, following new installations or components, after prolonged shut down of areas or buildings and significant contamination or biofouling. Methods are provided for thermal and chemical (chlorine based) disinfections.
A new section for HSG274 having not been part of the old ACoP but there was a separate publication from the HSE for residential accommodation. It is always a discussion point as to where responsibilities lie in shared premises. To summarise. the responsibility lies with who has control of the premises and they have a duty of care to all the occupants and users. Single occupant leaseholders may have full repairing lease on the building, therefore responsibility will often lie with them. It all very much depends on how the contract is arranged, if there is no contract then duty is on whoever has control of the premises.
In residential accommodation, landlords will have responsibility for legionella control; if properties are managed by an agent the contract needs to state who has responsibility. Further advice is provided on risk assessing, monitoring unoccupied premises. The basics of legionella control, temperature control and flushing apply in all instances. Risk assessments can be undertaken on a proportion of properties if they are all the same, but all properties must be risk assessed in a rolling programme.
Another new section for the HSG274; patients or residents in healthcare and care homes are more susceptible to contracting legionnaires’ disease and therefore control measures may need to be different to non-healthcare buildings. Differences include hot outlet and return temperatures being no less than 55°C, the consideration of scalding, flushing outlets at least twice weekly, regular legionella sampling in augmented care units and the formation of Water Safety Groups (WSG) and Water Safety Plans (WSP) as legionella is not the waterborne pathogen that be a risk to patients or residents in these types of premises. More detailed advice for healthcare premises is provided in Water systems: Health Technical Memorandum 04-01.
At the rear of the document are 5 useful appendices, on the content of a risk assessment, written scheme and action to take in the event of an outbreak of Legionellosis. There are also 2 schematics identifying sentinel point location for hot water systems.
HSG274 is very well written, comprehensive and detailed document covering all aspects of legionella control in domestic hot and cold water systems. Is it an improvement? Most certainly but there are areas missing that are often found in new buildings, such as rainwater harvesting systems and grey water systems, but overall what is required for legionella management and control in domestic water systems is now much clearer to understand. HSG274 Part 2 along with Parts 1 and 3 and the revised ACOP should help make legionella management and control for the duty holder, responsible person and everyone else involved much easier.
Do you have to do anymore than keep domestic water systems clean, moving, and at the right temperature? The short answer to that is no, but HSG274 Part 2 provides more information on how to go about it. If you already have good control measures in place then it is very much business as usual. However there a number of changes, as described above, that may affect how the risk from legionella in your domestic water systems is managed and controlled. The key message from the HSE is proportional control based on propionate guidance along with regular reviews of the legionella risk assessment and the control measures currently in place to see if any changes or improvements are required.
SOCOTEC will be happy to meet with you and discuss the changes in the ACoP and HSG274 Parts 1-3 and how they affect your management and control of legionella.
We have a many years of experience in the industry and can offer a comprehensive range of services to help you manage the risk from legionella including:
If you need to discuss the contents of revised ACoP L8 4th edition or HSG274 Parts 1-3 or this report please contact us at salesuk@socotec.com
