Pre-Planned Maintenance

Legionella Control in Water Systems

Legionnaires’ disease or Legionellosis is a potentially fatal form of pneumonia. People may get infected when they breathe in tiny water droplets (aerosols) or droplet nuclei (particles left after the water has evaporated) contaminated with elevated concentrations of Legionella bacteria.

Legionella bacteria grow best between temperatures of 20°C – 45°C, with optimum growth temperature being 35°C – 40°C. High temperatures (minimum 60°C) usually kill the bacteria.

Legionella bacteria are found in low numbers in natural aquatic environments, for instance, lakes, rivers and ground water. As a result, it is virtually impossible to prevent Legionella bacteria entering man-made water systems.

In low numbers the bacteria are generally considered harmless. With the correct conditions, for example, warm water, the presence of micro-organisms and nutrients in the water or materials such as rust, these bacteria can grow and multiply to high levels which increase the risk of exposure.

The bacteria tend to grow in biofilms (slime). Biofilms are likely to form on surfaces where there is low water flow or water is allowed to stagnate. However the growth of Legionella bacteria can be controlled.

Your responsibilities

As a buildings/facilities manager or Responsible Person, you have clear responsibilities around the control of Legionella bacteria in your water systems. Specifically, you MUST:

  • Identify and assess sources of risk using competent help and advice;
  • Prepare a scheme for preventing or controlling the risk;
  • Implement, manage and monitor precautions;
  • Keep records of the precautions;
  • Appoint a person to be managerially responsible.

Legionella Control

Water Hygiene monitoring

  • Weekly flushing of little used outlets
  • Monthly temperatures from sentinel & random outlets inc any hot water cylinders
  • 3 monthly Shower head clean & descales
  • 6 monthly Water sampling and analysis. Hot water cylinder blow down/inspection. Cold water storage tank inspection
  • Annually sampling and water analysis, Cold water storage tank clean and disinfections inc down services.

Remedial Actions (see L8 Remedial works page for more details)

  • Clean & disinfection of domestic hot & cold water systems, CWSTs (old or new)
  • Clean & disinfection of new mains pipework and reservoirs
  • Tank replacement programmes
  • Tank refurbishment and relining programmes

For more information about Legionella Risk Assessments and advice on how to implement a Legionella Management programme, email or call 01543 574208

The Legislation & Guidelines for Legionella Control

We adhere to and utilise the following documents, when devising legionella control programmes:

UK Legionella related legislation & guidance

  • Health & Safety at Work etc Act 1974
  • The Management of Health & Safety at Work Regulations 1999 as amended 2003 & 2006
  • The Control of Substances Hazardous to Health Regulations 2002 as amended 2003 & 2004
  • The Notification of Cooling Towers and Evaporative Condensers Regulations 1992
  • TM 13:2013 CIBSE Technical Memorandum – Minimising the risk of Legionnaires’ Disease
  • HSE document L8 – Legionnaires’ Disease, The control of Legionella bacteria in water systems: Approved Code of Practice (ACoP) and Guidance (Version 4)
  • HSG274 Part 1 – The control of legionella bacteria in evaporative cooling systems
  • HSG274 Part 2 – The control of legionella bacteria in hot and cold water systems
  • HSG274 Part 3 – The control of legionella bacteria in other risk systems.
  • HSG220 – Health & Safety in Care Homes (June 2014)
  • HSG 282 The control of legionella and other infectious agents in spa-pool systems
  • HTM 04-01 – The control of Legionella, hygiene, “safe” hot water, cold water and drinking water systems
  • Scottish Health Technical Memorandum SHTM 04-01: Water safety for healthcare premises Part A Design, installation and testing, Part B Operational management.
  • The Water Supply (Water Quality) Regulations 2010
  • The Water Supplies (Water Quality) (Scotland) Regulations 2011
  • The Water Supply (Water Fittings) Regulations 1999
  • BS 8580:2010 Water quality. Risk assessments for legionella control. Code of Practice
  • BS 8558:2015 – Guide to the design, installation, testing and maintenance of services supplying water for domestic use within buildings and their curtilages.
  • BS 8554:2015 – Code of practice for the sampling and monitoring of hot and cold water services in buildings
  • BS 7592:2008 Sampling for legionella bacteria in water systems – code of practice
  • BS PD 855468:2015 – Guide to the flushing and disinfection of services supplying water for domestic use within buildings and their curtilages
  • WMSoc Guidance Documents.

HSE charges for intervention

Under The Health and Safety (Fees) Regulations 2012, those who break health and safety laws are liable for recovery of HSE’s related costs, including inspection, investigation and taking enforcement action. This enables the HSE to recover the cost of a visit to any premises where a ‘material breach’ has been identified. A material breach is:

  • No legionella risk assessment in place
  • No appointed person to manage equipment deemed to be a legionella risk
  • Lack of documentation for legionella monitoring programme
  • Signs of organic contamination or scale in a water system

The HSE charge £124 per hour for their Fees For Intervention programme. Since its introduction in 2012, £2.67million has been invoiced to UK businesses and organisations, demonstrating a high level of ignorance amongst those responsible for building maintenance as to the serious nature of non-compliance.

Whatsapp Business Contact

Here at S P Environmental Services we have set up a WhatsApp Business contact, we understand that whilst looking for a quote you might not be at your computer or have time to call. We have set up our WhatsApp Business contact number for ease of quoting. All you have to do is save the below number in your phone as SPES and send over the deatils of the works you require quoting. It's always best to include as much information as possible such as:

  • Site Address
  • Works Required
  • Company Name
  • Specific job requirments (samples etc)

Our WhatsApp Business number is 

+447583611867 (This line is open 24/7 for whatsapp messeges ONLY)

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