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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

Get a quote today by phone, email, or complete our contact form to receive a quotation within 24 hours.


Our coordinator will be in touch to confirm a Date That Suits You, along with estimated time of arrival.

Your Appointment

On the day of your appointment, you will receive a 30 min Curtesy Call from an engineer to confirm they're on route.


Your report is then Quality Checked and emailed in PDF Format, with Next Day Delivery.

Support Call

Our support team will be in touch to arrange your free 30 min Support Call to help explain your report.

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 await payment. Reports are typically next day delivery, but please allow for up to 5 working days delivery.

Your Dedicated Safety Team

water quality monitoring


Customer Service

water quality monitoring



water quality monitoring



Legionella Control Services



Water Tank Cleaning & Disinfection FAQs

Will my tank need cleaning periodically?

Your cold water storage tank will require cleaning and disinfecting as per the condition of the tank. There are no legal requirements to clean tanks annually unless you have a potable drinking water tank.

Are uRisk qualified?

Yes, all of our assessors are fully qualified and accredited by City & Guilds legionella control association and can help assist you in meeting compliance today for HSE (ACoP L8), and provide landlords with guidance for hot and cold water low risk systems. We are also Safe Contractor and Construction Online approved so you can rest assured that you are working with a trusted water hygiene service provider who put health and safety first.

All our engineers are DBS Checked to ensure suitable people are entering your premises and to safeguard vulnerable people. We are committed to maintaining the highest standards.

Do uRisk service my area?

Yes, our services are nationwide. Whether you have one or multiple water systems and one or multiple sites, we provide services across the country, with qualified engineers scattered throughout the UK and offices based in Hertfordshire which is a 30-minute train journey to London King’s Cross. Get in contact with us and book an appointment where we can carry out a legionella risk assessment. We will look at factors like your water temperature, redundant pipework, where your water is stored and test for bacteria in water systems.

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.

We have been working with Urisk for best part of year now. I could not recomend their services highly enough. They always promptly respond to our requests promptly and manage the job from start to finish seamlessly. I would highly recommend.
Sam Guest
Sam G.
My first time using Urisk for work at multiple sites. Daniel was absolutely brilliant, polite and professional. Highly recommended! 🙂
Claire Keay
Claire K.
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 P.
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 T.
Really easy to organise a risk assessment to be carried out at our offices and have had great help from them since to implement the necessary changes to keep the office safe. Would definitely recommend.
Holly Ferguson
Holly F.
Brilliant Service, efficient, professional, punctual and friendly.
Alex Windsor
Alex W.
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 P.
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 G.
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 P.
Brilliant service! Thanks a lot for the hard graft
Leon Macauley
Leon M.
Daniel did the testing today at PGHC He was really efficient, friendly and so professional. An absolute pleasure to deal with. Thanks Daniel
Lorraine Carruthers
Lorraine C.
My experience with URisk Water Hygiene from my initial enquiry, to their site visit to undertake a Legionella Water Risk Assessment at my office (MDG), to providing me with the report and aftercare has been superb! Efficient response times, excellent customer service, friendly, helpful advisors and assessors who are always ready to help and provide guidance. An absolute pleasure to deal with, I highly recommend!
Lauren Wakeman
Lauren W.
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 M.
Richard & Nick are great. Really good work and nice people.
Joshua Ballard
Joshua B.
This is by far the best service I have received in a long time.Lloyd who we spoke to was super helpful and very thorough with everything.I would def recommend using this company, they are not just out for money they put their customers needs first.Thank you
Coral Dawkins
Coral D.
Extremely happy with our legionella risk assessment carried out by uRisk, easy to understand and great customer service. Thanks again
Nickayla Robertson
Nickayla R.

We want to help you comply!