Legionella Written Scheme of Control for Education Properties

Schools, Colleges, and Universities, by their varied nature, bring a great mixture of water-based systems that bring a variety of risks. Whether it be a water feature, a staff kitchen, an outside tap, or a complex laboratory building, each water system needs to be operated and managed correctly to prevent bacterial growth.

Following the guidance of the HSE Approved Code of Practice L8 – Legionnaires’ disease – The control of legionella bacteria in water systems and its supporting technical guidance your water systems will adequately control the legionella hazard.

This blog focuses on one aspect the ‘Legionella written control scheme’

Do I need a Legionella Written Scheme of Control?

The legal requirement to comply with the Management of Health and Safety at Work Regulations 1999 means all organisations should have a written scheme of control for each of their water systems. This is further supported by HSG274 which is the technical guidance that supports the HSE Approved Code of Practice L8 – Legionnaires’ disease, The control of Legionella bacteria in water systems.

What is a Legionella Written Scheme of Control?

The content of the Legionella written control scheme should reflect the simplicity/complexity of the water system in question.

Appendix 2 within HSG274 Part 2 gives the specifics of what is required but quite simply, it’s a written document that details the characteristics, components and practical operational methods and management of your water system to help maintain the compliant control of legionella bacteria.

Guidance documents can be found here>

https://www.hse.gov.uk/pubns/books/l8.htm

https://www.hse.gov.uk/pubns/books/hsg274.htm

How to control Legionella bacteria.

The key Legionella control measures are:

• Avoid stagnation of the water within the water system.
• Maintain cold water temperature below 20^oC and hot water temperatures above 50^o
• Prevent/remove deposits that can support bacterial growth, such as rust, sludge, scale, and organic matter.
• Minimise the creation of water droplets/aerosol.

Existing Water Systems

Schools, Colleges, and Universities are naturally subject to varied patterns of use, which in turn can affect the planned preventative maintenance schedules.

Some examples and possible solutions are:

• Summer, Christmas, Easter, and half-term holiday closures bring low usage, leading to stagnation. To prevent this, a dedicated team should be mobilised to ‘flush’ all outlets to simulate normal usage.
  
  
• Restricted access areas, such as laboratories or roofs, may require staff inductions to allow access to deliver PPM. This should be documented and factored into staff training.
  
  
• Sports and Catering facilities may be subject to intermittent/seasonal use, giving an apparent opportunity to save energy by turning hot water systems off for periods. This should be avoided. Your stored hot water should be above 60^oC and achieve at least 50^oC at the outlets. If an extended period of closure is planned, the risk assessment needs to be reviewed and the written scheme updated to reflect the changes.
  
  
• Evaporative cooling systems that use water to improve the cooling effect will bring intermittent water usage, i.e., none during the cooler/winter months. Some have an automated ‘flush’ cycle, but others require manual flushing.
  
  
• The geographical location of facilities brings different characteristics too, such as being in a hard water area. This increases the buildup of scale; therefore needs to be controlled. Depending on the purpose of the outlet, a water softening plant could be used, but if not, an enhanced de-scaling programme may be required.
  
  
• Refurbishment projects have an impact on water systems and will change the requirements of your written scheme. Modifying existing water systems can create isolation and dead legs in readiness for future connection; these require regular flushing too. Equally, a contractor could be handed a facility to redecorate only but this again impacts on low or no use of the water systems contained within that space.
  
  

These types of variances bring the need for each water system to have its own specific written scheme of control, with each based on its unique nature. The written schemes should also be updated to reflect any unforeseen changes that bring a change to the ‘norm’.

Your written scheme should reflect the recommendations of your legionella risk assessment and organised to coordinate with business operations. They should be reviewed regularly and updated to reflect any changes in anticipation of the change rather than a reaction.  

New Water Systems and Capital Projects

The Construction Design and Management (CDM) Regulations state that it is not only the Client who is the duty holder, but the project team too.

Be mindful that if demolition and construction projects use or introduce water systems, they too are subject to ACoP L8 and each water system should have its own Legionella risk assessment and written scheme.

Examples of such arrangements are:

• Dust suppression systems
• Site welfare facilities
• Vehicle wash facilities
  
  

Designers should, through the design phase risk assessment, identify what risks exist because they cannot be ‘designed out’ of the water system. This way, the required preventative measures can be considered at an early stage and passed to the Contractor.

Designers and Contractors have the responsibility to provide Operating and Maintenance (O&M) manuals to advise how the facility, including water systems, should be operated and maintained. Architectural, mechanical services, and building management/control systems information should be consolidated and compiled within a specific legionella section that provides relevant information for the written scheme of control. The information should be clearly written in a style that can be understood by non-technical readers and not bulked out with irrelevant manufacturers' blurb.

Feel free to reach out if you have any questions about the issues mentioned above or if you would like to consult with one of our experts on water hygiene.

Editors Note: The information provided in this blog is correct as of the date of original publication - November 2025

© Water Hygiene Centre 2025