Legionella contaminations can lead to Legionnaires' disease, which can be fatal, so FMs must make sure hot and cold water systems are free from bacteria, says Jamie Tranter.
03 December 2018 | Jamie Tranter
Every sector is at risk of legionella bacteria breeding in hot and cold water systems, and those managing facilities need to protect users from risk.
However, legionella contamination can also happen beyond your facilities' walls such as when contaminated water droplets enter the air through an aerosol commonly seen on cooling towers.
In the late 1990s, a motorist died after inhaling airborne legionella-contaminated water droplets while driving a mile from the contaminated site.
The risk is real, but it's not easy to detect the symptoms of a poorly managed water system.
Codes of practice
The HSE has issued Approved Codes of Practice (ACoP) including L8, which outlines the recommended requirements for the control of legionella bacteria in water systems, and HSG 274, which outlines what businesses must do to comply with L8.
The code requires every business to have:
- Clear allocation of management responsibilities;
- Competent personnel;
- A description of the water system and up-to-date schematic diagram;
- A risk evaluation;
- Safe operating procedures for the water system;
- Monitoring, inspection and maintenance procedures;
- Recorded results of monitoring, inspection and any checks carried out; and
- Arrangements to review the risk assessment regularly, particularly if there is reason to suspect it is no longer valid.
Healthcare facilities have tougher codes of practice because patients are often susceptible to legionella infection. These facilities must adhere to the Department of Health and Social Care's HTM 04-01 guidance on the management of water supply systems.
Key areas to assess
The first step in controlling the risk is assessing your water system. HSG 274 identifies three areas that should be subjected to risk assessment:
- Cooling towers;
- Hot and cold water systems; and
- Any system that poses a risk by producing airborne water droplets.
Check the old pipes
A comprehensive assessment should include inspection of obsolete pipework (known as dead legs or dead-ends) such as pipes connecting to unused taps where water can stagnate and encourage legionella growth.
Hemp joints are notorious for bacteria and should be replaced with safer alternatives that comply with the Water Regulations Advisory Scheme (WRAS) approval scheme 27, which lists products compliant with BS 6920 (non-metallic products in contact with water for human consumption).
Flexible hoses, often lined with ethylene propylene diene monomer can encourage growth of legionella bacteria. While EPDM hoses are banned in healthcare environments, they can be found in water systems in other sectors. These should be replaced by non-EPDM hoses or solid copper fittings.
HSG 274 also states that major assets such as cold storage tanks, calorifiers and cooling towers, must be inspected for scale, corrosion and sediment, which are signs that legionella bacteria may be present.
Note: A risk assessment must also include a schematic drawing of the water systems and temperature profile of the assets and outlets.
Seek specialist help
Assigning the responsibility to an underqualified person could result in non-compliance and an unsafe water system so, in many cases, FMs will outsource the responsibility. Choose an experienced provider that supplies you with a tailored risk assessment and risk management solution to meet your business's specific requirements.
Jamie Tranter is business development manager at Clearwater Technology