Are Concrete Water Tanks Safe? 19th November 2021

Are Concrete Water Tanks Safe?

When choosing a water storage tank, it is always best to seek professional advice in order to get a water tank that is best suited for your needs.

This is especially important if you are storing potable (drinking) water. There are a variety of cold water storage tanks available, including concrete tanks, steel tanks, galvanised steel tanks and GRP (glass reinforced plastic) tanks.

In this blog, we are going to answer your question “are concrete water tanks safe?” and share our advice on the best cold water storage tank for you.

Are Concrete Water Tanks Safe For Storing Potable Water?

In general, concrete water tanks are safe for storing potable water.

The reinforced cement concrete is durable and long-lasting. They also have a thermal mass, which helps keep the water temperature stable during extreme temperatures. This is beneficial for drinking water.

However, concrete water tanks are not as flexible as other types of cold water tanks and may experience issues over time.

The Risks Of Concrete Water Tanks

Over time, concrete water tanks will weaken, resulting in cracks in the concrete. This provides space for bacteria to grow.

Legionella bacteria is a common bacteria found in water tanks when the environment is not right. Legionella bacteria if inhaled can cause serious illness and even death.

It is particularly dangerous to those aged 45+, smokers, heavy drinkers and those with compromised immune systems. The cracks in the concrete can also lead to leaks, which must be repaired swiftly. Leaking is a common problem with concrete water tanks.

In addition, if the water stored in the concrete tank is acidic, it can leach the calcium carbonate from the concrete into the water, resulting in hard water.

Concrete Water Tank Repairs

Problems can arise with concrete water tanks, but that doesn’t mean you need to get rid of your tank. More often than not, concrete water tanks can be repaired.

Especially if you seek help from a water treatment specialist. Here at Cold Water Storage, we will also aim to provide the most cost-effective and efficient solution to your problem.

For example, if your cold water is leaking due to years of erosion, we will likely offer a repair and reline providing the tank is still structurally sound.

A repair and reline will be more cost-effective than a complete replacement and will have less disruption and downtime for the building.

Check out this case study, where we repaired and relined a concrete water tank at a National Museum. The client had previously been told by another contractor that they would need a brand new tank.

But upon inspection, we determined that their concrete tank still had plenty of life left in it. The project included:

  • Mechanically preparing all internal surfaces to raise a profile on the substrate.
  • Mixing and then applying a cementitious screed onto the surfaces, thus filling in and smoothing the defected areas.
  • Applying a three-coat WRAS approved lining system to the base, walls and ceiling of the tower.

Whilst on site, we also found the inlet pipe was badly corroded, so we replaced this with a stainless-steel pipe and a new float valve. Upon completion, the tank was safe, fully compliant with all legislation and guaranteed to last another 10 years.

Other Types Of Cold Water Storage Tanks

If you need a new cold water storage tank, we would usually recommend opting for a GRP tank. GRP is a fibre reinforced polymer made up of fibres of glass.

Glass-reinforced plastic water tanks are built using sectional GRP panels that have been approved for use by the Water Regulations Advisory Scheme. This means they are suitable for potable water.

The GRP tanks supplied by Cold Water Storage are manufactured in Britain using only the highest standards. This extremely tough and durable material will last for years to come.

The GRP tanks are lightweight and available in a range of shapes and sizes. Plus, they are non-corrosive, making them resistant to water contamination and bacteria growth.

Need Support From A Professional?

If you have a concrete water tank that needs repairing, we can help. Our water treatment experts will be able to inspect your tank and offer a range of solutions.

Alternatively, If you need a new water storage tank, we will be able to recommend the best tank to meet your needs. Get in touch for more information. You can call us on 01943 872311 or email us at

Cold Water Storage has a collective 30 years of experience in the water hygiene and legionella industry. Our core services include cold water tank cleaning and disinfection, repair and relines, modification, replacement and installation.

We also provide water treatment services, including Legionella prevention and management.