Legionella bacteria pose a serious risk to water systems, and as a facilities manager, ensuring compliance with UK regulations is crucial. But what exactly are Legionella remedial works, and how can you keep your water systems safe?
If you manage a building, whether it’s a hospital, school, office, or retail space, you have a legal and moral duty to ensure the water supply is safe. Legionella outbreaks can lead to serious illness, legal consequences, and reputational damage. In this guide, we’ll break down key remedial actions, best practices, and real-world solutions from our experience at Titan Mechanical Services.
What Are Legionella Remedial Works?
Legionella remedial works refer to corrective actions taken to reduce or eliminate the risk of Legionella bacteria in water systems. These works go beyond risk assessment and monitoring, by actively addressing problems like poor water circulation, temperature control failures, and contamination in tanks and pipework.
How Does Legionella Develop in Water Systems?
Legionella thrives in stagnant water with temperatures between 20-45°C. It becomes a major concern in cold water storage tanks, dead legs, showerheads, and complex pipework systems where biofilm can build up. Without proper maintenance, facilities are at risk of Legionnaires’ disease outbreaks.
The Importance of ACOP L8 Compliance
The Approved Code of Practice (ACOP) L8 and HSG274 guidance outline the legal responsibilities for managing Legionella risks. Non-compliance can lead to hefty fines and, in worst cases, legal action. Remedial works ensure your facility remains safe and meets these compliance standards.
Key Remedial Actions to Control Legionella
At Titan Mechanical Services, we’ve helped numerous clients in healthcare, education, and retail sectors tackle Legionella risks. Here are some of the most effective remedial actions:
1. Temperature Control Measures
Maintaining water at the right temperatures is one of the simplest yet most effective ways to prevent Legionella growth.
Hot water should be stored at 60°C or above and reach at least 50°C at outlets within one minute.
Cold water should be kept below 20°C to prevent bacterial growth.
Regular flushing of little-used outlets (such as in seasonal buildings) helps prevent stagnation.
One of our clients, a large care home, struggled with fluctuating water temperatures in their system. By recalibrating their thermostatic mixing valves (TMVs) and insulating pipework, we helped them achieve consistent compliance.
2. Cold Water Storage Tank Cleaning and Repairs
Storage tanks are a hotspot for Legionella contamination if not maintained properly. Sediment build-up, corroded surfaces, and biofilm formation create ideal conditions for bacteria.
Routine tank cleaning and disinfection using chlorine or silver stabilised hydrogen peroxide.
Tank relining or replacement to eliminate corroded surfaces where bacteria can thrive.
Upgrading tank insulation and covers to maintain proper temperatures and prevent external contamination.
We recently worked with a retail client whose old storage tank was harbouring Legionella due to internal rusting. A full tank reline, along with improved monitoring, brought them back into compliance.
3. Removing Dead Legs and Redundant Pipework
Dead legs and little-used pipework sections are prime areas for Legionella growth due to stagnant water.
Identify and remove unnecessary pipework during system inspections.
Introduce secondary recirculation loops to improve flow in large buildings.
Ensure regular flushing of rarely used outlets, such as in vacant office spaces.
A university we worked with had an extensive pipe network, some of which hadn’t been used in years. By removing redundant sections and installing recirculation systems, we drastically reduced their Legionella risk.
Ongoing Monitoring and Maintenance Strategies
Once remedial works are in place, regular maintenance is key to ensuring Legionella doesn’t return.
1. Legionella Testing and Sampling
Regular water sampling and testing confirm that Legionella levels remain under control.
Monthly temperature checks at sentinel points.
Quarterly microbiological sampling, particularly in high-risk systems.
Regular full-system risk assessments to identify potential issues early.
2. RPZ Valve and Backflow Prevention Maintenance
Backflow prevention devices such as RPZ valves (Reduced Pressure Zone valves) play a crucial role in preventing contaminated water from re-entering clean systems.
Annual RPZ valve testing to ensure they function correctly.
Replacing faulty or ageing devices to maintain compliance with water regulations.
3. Staff Training and Compliance Reviews
Ensuring that maintenance teams understand Legionella risks and prevention strategies is just as important as the physical works themselves.
On-site training for facilities staff on Legionella risk management.
Documentation and logbook management for compliance records.
Regular compliance audits to ensure systems stay within ACOP L8 standards.
Take Action to Protect Your Facility Today
Legionella remedial works aren’t just about ticking compliance boxes—they’re about safeguarding the health of building occupants. Whether it’s storage tank cleaning, temperature control improvements, or dead leg removal, taking action today can prevent costly issues tomorrow.
We hope you have found this article useful. If you still have unanswered questions, then feel free to get in touch for a chat, and one of our friendly team will be happy to help.
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