Water Tank Cleaning and Disinfection in Ireland

Cold water storage tanks supply taps, showers and equipment throughout a building, so the condition of the tank affects the quality of the water everywhere it goes. Safer Solutions carries out water tank cleaning and disinfection for businesses, care providers and landlords across Ireland, including Dublin, Cork, Limerick and Galway.

Why tank cleaning and disinfection matters for Legionella control

Legionella bacteria can multiply in water that is warm, stagnant and rich in nutrients. In general, they grow between about 20°C and 45°C, and a dirty storage tank gives them what they need:

• Sediment, scale, rust and debris build up on the base and sides of the tank and can feed bacteria.
• A slimy layer called biofilm can form on surfaces and shelter bacteria from disinfectant.
• Gaps in the lid, damaged screens or poor insulation let in dust, insects and even birds, and allow the water to warm up.
• Water that sits for long periods in a large tank can become stagnant, especially in buildings with low use.

If contaminated water is then released as a fine spray, for example from a shower, people can breathe in the droplets. Legionnaires’ disease is a serious lung infection, and the Health Protection Surveillance Centre (HPSC) and the Health and Safety Authority (HSA) both provide guidance on how to prevent it.

Why it must be done

• It is part of controlling the risk. The HPSC National Guidelines for the Control of Legionellosis in Ireland (2009) treat storage tanks as part of the water system that should be inspected and kept clean, with disinfection where needed.
• You have legal duties. Under the Safety, Health and Welfare at Work Act 2005, employers must identify hazards and manage risks to people at work, and those in control of premises have duties to others who use them. A dirty tank is a hazard you can remove.
• It protects people. Care homes, schools, hotels, gyms and workplaces all have people who could be exposed, including those who are more vulnerable.
• It protects your business. Clean tanks and written records show you have taken reasonable steps.

When should a tank be cleaned?

• When an inspection finds sediment, debris, slime or damage.
• When a Legionella risk assessment or a sampling result recommends it.
• After building work, repairs or a long period of non-use.
• When a tank is new, replaced or being brought back into service.
• If you have no record of the last clean or inspection.

Regular inspection is the starting point. Our guide to inspecting cold water storage tanks explains what to look for, and water tank cleaning: when it is needed and what to expect covers the job in more detail.

What we do

• Inspect the tank, lid, screens, overflow, vents and insulation.
• Remove sediment and debris and clean the interior.
• Disinfect the tank where the situation calls for it.
• Check that the tank is secure and properly covered before it is returned to service.
• Give you a record of the work for your Legionella logbook.

Cleaning works best alongside a Legionella risk assessment and, where recommended, water sampling, with samples analysed by an independent accredited laboratory.