Following a legionella risk assessment, you may find that one of the biggest risks on your premises is your cold water storage tank. This is because many water tanks in use today were made from galvanised steel in the 70s and 80s, and are therefore susceptible to corrosion and contamination.

However, replacing a water tank because of corrosion can be costly, and absorbing this cost may not be viable for your business on day one. Here’s how you can stay safe and compliant while keeping water tank replacement costs down.

Tank refurbishment instead of replacement

The most common reason that water treatment professionals recommend water tank replacement is corrosion affecting the inside surfaces of the tank. Sometimes, it’s possible to combat this with refurbishment instead of replacement.

Specifically, you can either repaint or replace the surface with a new rubber lining. We recommend the former route, using specialist paints designed for use in galvanised steel tanks.

This will offer you the best possible protection against corrosion, whereas using a rubber lining may invite further risk. This is because it can tear or be punctured, allowing water to seep out of the lining and come into contact with contaminants (as well as reaching temperatures conducive to legionella growth).

Bear in mind, however, that refurbishment may in fact cost more than replacement depending on the size of your site and water tank. Your water treatment company undertaking the risk assessment should you be able to advise you on the best and most cost-effective course of action.

Types of replacement water tank

In some cases, no amount of refurbishment will be enough to address the effects of corrosion in your water tank. The next thing to consider, then, is the type of replacement tank you will install, as some will cost much more or less than others.

A glass-reinforced plastic (GRP) water tank tends to be the best option in terms of resistance to corrosion. These are constructed using a fibreglass material known for extreme durability.

If a GRP tank is not within your budget, however, an alternative is a domestic polyprop tank. These are a lot cheaper, and generally acceptable for use in smaller buildings.

Remember: You have time to act

In any case, don’t panic – you don’t have to replace your tank straight away, as long as you make it clear in your written scheme for legionella control that at some point in the future you mean to do so.

This is because most regulators accept that legionella control is only possible so far as it is reasonably practicable. If you can’t afford to buy a replacement water tank on day one, but still implement a legionella control scheme devised by a water treatment professional that uses your available resources to the best possible effect, you’ll be compliant with the guidance of the HSE and other bodies.

There are various documents on legionella control, and it can be hard to distinguish advice from mandatory regulation. We’ve created a handy checklist that lets you quickly and easily see what you need to do.