How to Approach Legionella Remedial Works
- Joe Pettigrew
- 1 day ago
- 4 min read
As a facilities manager, you know how important water hygiene compliance is - not just for ticking boxes, but for protecting the health of your building users. If you’ve recently had a Legionella risk assessment, you may be looking at a list of recommended remedial works. The big question is: do you tackle just the high-risk items now, or sort the entire system in one go?
This guide explores the pros and cons of both approaches to help you decide which is right for your site.
Understanding the Risk Behind Legionella
What Is It and Why Should You Act?
Legionella bacteria thrive in warm, stagnant water, and can cause Legionnaires’ disease - a potentially fatal form of pneumonia. They can multiply quickly in water systems where conditions allow, such as poorly maintained tanks or low-use pipework.
What Are Your Legal Duties?
In the UK, the Health and Safety Executive (HSE) requires building duty holders to comply with ACoP L8Â and HSG274 guidance. This includes:
Carrying out regular risk assessments
Implementing control schemes
Completing remedial works where necessary
Failing to act isn’t just a legal risk — it could lead to serious health outcomes and reputational damage.
Two Ways to Tackle Legionella Remedials
Let’s look at the two most common approaches:
Option 1: Prioritise High-Risk Items First
Pros
Tackles the most serious risks fast:Â You focus on the items that present the greatest threat to health, such as water outlets testing positive for Legionella, or tanks that aren't maintaining the right temperature.
More budget-friendly upfront:Â If your budget is limited, this staged approach spreads the cost over time.
Quicker wins:Â You can often get started quickly and demonstrate progress internally.
Cons
Lower-risk issues still exist: If left unaddressed, moderate or low-risk items may become more serious over time - meaning you’re always one step behind.
Potential for repeat disruption: You’ll likely need contractors on site again later to deal with outstanding works, which can impact users and maintenance scheduling.
Cumulative costs can build: You might end up paying more long-term if you’re mobilising multiple jobs in separate visits.
When This Might Work Best
A high-occupancy building like a care home or a hospital wing, where speed is critical and budgets are tightly controlled, may opt to target only urgent issues first - especially if they pose an immediate compliance or health concern.
Option 2: Complete All Recommended Works at Once
Pros
One-time disruption:Â All work is completed in a single phase, which reduces downtime and avoids repeated site mobilisation.
Peace of mind:Â The entire system is brought up to spec, not just the critical points.
Easier to manage:Â You can sign off your action plan in full, which is useful during audits or when producing evidence for the HSE.
Cons
Higher initial spend:Â Even with long-term value, the upfront cost of a full programme can be a hurdle.
More planning needed: Coordinating multiple remedial actions across various systems may require more time, team coordination, and scheduling.
May address non-urgent items: Not every issue may need urgent attention, so you may feel you’re solving problems that aren’t yet critical.
When This Might Work Best
Larger sites or organisations with capital budgets earmarked for compliance may find it more efficient to address all remedial works in one go - especially if their water system is ageing or has seen repeated non-conformances.
Common Legionella Remedial Actions
Whether you go all-in or prioritise critical works, you’ll likely encounter some of the following jobs:
Removal of Dead Legs
Sections of pipework with no flow, known as dead legs, can allow water to stagnate and encourage bacterial growth. Removing them improves system hygiene.
Storage tanks, calorifiers, and pipes often require cleaning and chlorination to remove sediment, scale, and biofilm.
Temperature Regulation
Systems should ensure hot water is stored at 60°C and distributed at no less than 50°C. Cold water should be kept below 20°C. Thermostatic mixing valves (TMVs), lagging, and trace heating can help achieve this.
System Repairs and Modifications
This might include re-routing pipework, fixing insulation issues, or replacing outdated components that no longer meet compliance standards.
What Else Should Be in Your Plan?
Monitoring and Record-Keeping
After completing any remedial works, a clear log of monitoring and maintenance is essential:
Temperature checks at sentinel outlets
Weekly flushing of infrequently used taps
Quarterly cleaning of showerheads and spray outlets
Routine inspections of tanks and valves
These steps demonstrate ongoing compliance and help you stay on top of any emerging issues.
So, Which Approach Is Right for You?
There’s no one-size-fits-all answer — the right strategy depends on your budget, building type, risk level, and long-term maintenance plans.
If cashflow is tight and your risk assessment shows only a few urgent issues, prioritising high-risk works may be a practical start. If you’re aiming for a clean slate, consolidating all remedials into one project can give you long-term value and peace of mind.
Whatever you choose, the key is not to delay. Every day of inaction increases your compliance risk and can put building users at unnecessary risk.
Explore More
To learn more about how we help clients stay compliant with Legionella control, visit our Legionella Remedial Works page.
Looking to understand the legal side? Check out our Learning Centre for guidance on HSG274 and ACoP L8.
If you’re still weighing up your options, our Water Hygiene Services section breaks down how to structure a compliant and cost-effective control programme.
Want Help Choosing the Right Approach?
Every site is different — and your remedial plan should reflect that. If you’d like a second opinion or support with your next steps, our team is here to help.
