Water Tank Cleaning

Water Tank Cleaning | Cold Water Tanks | Disinfection

Water tank cleaning and disinfection


Over time cold water tanks, often found in lofts, basements and airing cupboards become dirty with debris, sediment, scale, sludge, biofilm, fouling, wall mould, stagnation, rust & corrosion, foreign bodies and plant growth. Should contaminants enter our water tanks or build up over time, they provide a breeding ground for bacteria such as Legionella bacteria and E.coli.

An annual inspection of cold water storage tanks will determine if cleaning and/or disinfection is required, as stated in the ACoP L8 (HSG 274 Part 2). Annual water tank cleaning is not a legal requirement, but annual water tank inspections are, where the water tank is inspected for its condition internally and externally. The water tank inspection will identify if a water tank clean is required or not. Get a water risk assessment today.

Why do I need to clean my water tank?


Water tank cleaning is an essential part of water hygiene and Legionella control measures and something to be taken seriously both domestically and commercially. To maintain high quality water it is important that tanks are inspected regularly and cleaned when required to prevent bacterial proliferation. Protecting the water system’s users from potentially fatal diseases such as Legionnaires’ disease is vital, particularly when the users are vulnerable people such as children, the elderly, people with pre-existing illnesses, smokers, etc. These tanks should be inspected annually for their condition to identify if a water tank clean is required. To read more on cold water tank monitoring please visit our legionella monitoring page.

What else must I do with my tank?


Not only is it important to check your tanks for their internal conditions but they must meet design regulations as well, which help prevent bacterial growth inside the tanks. A poorly designed tank, clean or unclean may provide the right conditions for bacteria growth. For example, if your tank does not have a closely fitted lid, insects and bacteria may enter your tank. This is why tank design is just as important as a clean tank.

In summary, you must clean your tank where required, ensure it meets design regulations, and monitor your tank six monthly for its condition, design and temperature. Bacteria sampling is recommended on a six monthly basis to interpret the tank’s water quality. Legionella bacteria can double every 15 minutes.


How much is a tank clean & disinfection? 


Water tank cleaning costs vary in price depending on the number and size of your tanks. Small water tank cleaning prices for tanks ranging from 117L to 500L might cost you between £200-£500.

Where as larger water tank cleaning prices for tanks ranging from 1,000L to 30,000L normally cost in excess of £500-£2000+.

Water tank cleaning process


Inspect Tank Design


Drain Water Tank

Chemical Disinfection (?)


Drain Water Tank


Remove H&S Signage


Install H&S Signage

Clean Water Tank

Neutralise Water


Refill Water Tank

Water Free to Use


Isolate Water Tank


Refill Water Tank

Test Chlorine Levels


Un-isolate Water Tank

Certificate Sent

About the tank clean and how long will it take?


uRisk’s water treatment, tank cleaning and disinfection services are carried out by our fully trained engineers, provided with RAMS, method statements and procedures to ensure the work complies with the ACoP L8 (HSG 274) and COSHH regulations. Disinfection works are carried out with the use of chlorine with all RAMS designed to ensure the safety of the water system’s users is paramount.

On average it can take our experienced engineers between 3-5 hours to clean your water tanks. However, the time taken to clean the tank often depends on a number of factors such as how dirty the tank is, how accessible the tank is, and the size of the incoming and outgoing pipework from the tanks to list a few factors.


When do I need a chlorination?


Where necessary, hot and cold water services should be cleaned, flushed and disinfected in the following instances, as specified in BS 8558:2011:


  • New water system installations or refurbishment of hot and cold water systems
  • Installation of new components
  • Systems that have been out of use for long periods of time
  • Evidence of contamination or stagnation in tanks
  • Substantial alterations to the systems
  • Following sample results indicating contamination
  • During or following an outbreak of legionella
  • Where indicated by the risk assessment


If you are uncertain on the actions you need to take then contact our team today.

Do uRisk provide water testing or sampling?


Yes, we provide a wide range of water testing and sampling including legionella. All water tests are carried out in UKAS accredited laboratories.

Service process

Get a Quote

To get a quote you can phone, email or complete our ‘Get a Quote!’ form to receive a quotation within 24 hours.

Book an Appointment

Once you’re happy with your quote we’ll confirm a suitable date and estimated time of arrival for your appointment.

Your Appointment

An engineer will be with you on your scheduled date, and will call you prior to arrival (when safe and possible).

Report & Support

Our team will quality assess your report for PDF distribution, typically within 2-10 days of the site visit.

All payments are due prior to booking completion unless agreed in writing for 30 days from the date of invoice. We will hold your booking time for 24 hours whilst we wait for payment.

Your dedicated water hygiene team

Legionella Monitoring


Customer Service

Legionella Control


Quality Control

water hygiene monitoring



Legionella Control Services

Luke V

Business Manager

Why choose uRisk?

25 Years Experience

Over 25 years of water hygiene and legionella control experience.

Customer Service Excellence

Friendly and simple advice by phone, email & online at your convenience.

City & Guilds Qualified

All staff are trained water hygiene consultants and engineers.

Nationwide Coverage

With engineers located all across the UK, we're never too far away.

UKAS Accredited Testing

Our labs are UKAS approved providing you with quality assurance.

Full Compliance Services

Your one stop shop for Legionella control, no need to go elsewhere.

Brilliant company, customer service was great! And engineers were fantastic. Thanks again uRisk! Will definitely be using them for all future work.
Nikesh Gohil
Nikesh Gohil
12:49 12 Mar 18
uRisk have been helping us with our Legionella Control for a number of years now. We've recently had a CQC audit and they were very impressed with our legionella compliance! Thank you for all your help.
Mike Port
Mike Port
20:41 07 Aug 18
We're a small GP practice and started using uRisk for legionella risk assessments. We opted to use their remedial and monitoring services and they've been absolutely great. We cannot recommend them enough! Thank you so much!
Amanda Pates
Amanda Pates
18:30 07 Aug 18
Extremely happy with our legionella risk assessment carried out by uRisk, easy to understand and great customer service. Thanks again
Nickayla Robertson
Nickayla Robertson
21:22 15 Jan 19
Brilliant service! Thanks a lot for the hard graft
Leon Macauley
Leon Macauley
21:12 15 Jan 19
Fantastic training courses and we've found the legionella risk assessment very easy to read and far more detailed than any we have previously had. 5 star service!
Gemma Pond
Gemma Pond
20:37 07 Aug 18
A fabulous company, excellent customer service, they try to accommodate appoitments, and do there utmost in emergencies, been with them a few years now,  honestly cant fault them. Coming out of Covid 19, having our building urgently disanitised,  big thank-you to Luke and Lee for staying so late to get the job done!! Thank you Devon, for juggling the diary to fit us in so soon. A Team 🙂
Jo Maskell
Jo Maskell
18:02 15 Jun 20
Brilliant Service, efficient, professional, punctual and friendly.
Alex Windsor
Alex Windsor
18:21 15 Jan 19
Incredibly detailed and professional team. Have been beyond helpful with with our CQC legionella compliance for our Safety. They’ve found solutions to fit around how we work and our budgets. We are always advised with reference to HSE which has been brilliant.
Amy Thorne
Amy Thorne
20:29 07 Aug 18

We want to help you comply!