Table of Contents
The short answer
A household water tank should be cleaned and disinfected once or twice a year, and sooner if the water smells, carries grit or looks discoloured when a tap is first opened. That is the advice IHR Dream Cleaning gives for villa tanks, and it sits inside the minimum intervals in Abu Dhabi's published code for storage tanks, which are set out below.
The work itself follows one order everywhere: shut the supply, drain the tank, remove the sediment, scrub the inside, disinfect it, rinse, refill, and refit the lid and screens so that dust and insects stay out. Our water tank cleaning service adds a check of the pump and a written inspection report. A standard villa tank takes two to four hours from draining to refilling, and the water is off for that time.
In a villa the tank is the owner's or the tenant's concern. In a tower it belongs to the building, the building arranges the cleaning, and what you can do as a resident is ask when it was last done and prepare for the day the water is off. Both cases are covered here.
How often a water tank should be cleaned
There are two answers, and they agree. The first is practical. Sediment and a film of bacteria build up in every tank over time, whatever the quality of the water going in, so our service page recommends cleaning most residential tanks every six to twelve months, with larger shared and commercial tanks often done more frequently. A tank that has gone more than a year, or one with no record at all, should be treated as overdue.
The second answer is the official one. Abu Dhabi has a Code of Practice for the inspection and cleaning of customer water storage tanks, issued in 2015 by the emirate's water and electricity regulator and, as published in October 2026, available on the Department of Energy's website. It applies to tanks in all types of buildings, and it sets a minimum frequency for cleaning and disinfection that depends on what the tank is made of and where it sits.
| Tank material | Where it sits | Minimum in the code |
|---|---|---|
| Concrete | Underground or at ground level | 'Bi-annually' |
| Concrete | Roof | Annually |
| GRP sectional panels | Ground level | 'Bi-annually' |
| GRP sectional panels | Roof | Annually |
| Plastic, fibreglass or galvanised steel | Ground level or roof | Annually |
How to read that table
The code uses the word 'bi-annually' without defining it. Read it as twice a year. That is the cautious reading, and it matches common sense: a concrete tank at or below ground level is the type most exposed to seepage, sand and warm, still water. If a building's schedule or budget depends on the exact interval, confirm it with the municipality and do not rely on a dictionary.
These are minimums for normal conditions. The same code says a tank must be cleaned whenever an inspection finds signs of contamination, such as sediment, algae, an oily film, insects or an uncovered opening, whatever the date of the last clean.
The municipality's rules for cleaning companies
Companies that clean drinking water tanks hold a specific licence for that activity, and the Department of Municipalities and Transport sets rules for them. Its Circular No. 5 of 2024, as published in October 2026, tells every company holding that licence to follow the department's Administrative Decision No. 26 of 2018 on the health and safety of drinking water tanks. It also requires laboratory tests and sampling by a specialised laboratory technician, and a report that includes the building's basic details.
The 2018 decision may set a tighter interval for some buildings than the 2015 code does. Building owners and managers should check the current requirement with the municipality before fixing a schedule, and should not take the table above, or any contractor's leaflet, as the last word.
When to clean sooner than the schedule
The calendar is a backstop. These events are reasons to clean now and reset the date.
- You have just moved in and nobody can show you when the tank was last cleaned. This is one of the first items in our new home maintenance checklist.
- The home was closed for the summer and the water has sat in a hot tank for weeks. See reopening a home after summer travel.
- Plumbing or building work has been done on the tank, its pipes or the roof around it.
- A sandstorm found the lid open, cracked or missing.
- The water has changed: a smell, a taste, grit in the aerators, or a tint that was not there before.
Who is responsible for the tank
The official code places the duty on what it calls the responsible person: the owner, or whoever has taken on responsibility for the tank, which includes a registered building manager or agent. That person has to make sure the tank is cleaned and disinfected routinely, by a company licensed for the work, and has to keep the records.
In a villa
A villa has its own tank, on the roof, at ground level or below ground, and often one of each with a pump between them. If you own the villa, the tank is yours to maintain. If you rent it, your tenancy contract decides whether routine maintenance such as tank cleaning falls to you or to the landlord. Read the contract or ask before you book, and keep the report either way, because the next question at handover is when the tank was last cleaned.
In an apartment building
In a tower the tanks, the pumps and the pipes up to your front door are common property. You cannot book a clean of the building's tank and should not try to reach it. What you can do is ask the building management or the owners' association, in writing, three plain questions.
- When were the building's water tanks last cleaned and disinfected, and when is the next clean due?
- Which licensed company did the work?
- Can residents see the cleaning report or the water test result?
What a reasonable answer looks like
A well-run building answers those questions from a file. The code requires the owner or manager to keep inspection and sampling reports for five years and to show them to the municipality on request, so the records should exist. If the answer is vague and the water is visibly poor, put the complaint in writing to the management first. If nothing changes, the municipality is the body that inspects tanks.
Inside your own flat, you are responsible for what is yours: tap aerators, shower heads, any filter under the sink and the water heater. If grit or discolouration appears only at your hot taps, the building's tank is not the cause, and the reasons are in our guide to a water heater that is not heating or is leaking.
Who may do the work
Tank cleaning is a licensed activity in Abu Dhabi, as the circular above shows, and the code tells owners to engage a registered company and tells that company to show evidence of its registration when it is engaged. Ask for that evidence from any company you are considering, ours included, before the day. A general cleaning crew with a pressure washer is not the same thing. The work involves a confined space, a drinking water system and, in many cases, a laboratory sample.
Why a tank gets dirty when the water going in is clean
The code exists because water that leaves the network in good condition can lose that condition in storage. Three things happen in every tank, and Abu Dhabi's climate speeds up each of them.
- Sediment settles. Fine particles carried in the supply, flakes of scale and sand that has blown in sink to the floor of the tank and stay there. Every refill stirs the layer a little, and the pump draws from near the bottom.
- A film grows on the walls. Bacteria attach to any wet surface and build a slippery layer that ordinary flow does not shift. It grows fastest in warm, still water.
- The outside gets in. A lid that does not seat, a cracked cover, a vent or overflow without a screen: each is an entry point for dust, insects, lizards and birds. One windy day can put more sand into an open tank than a calm season.
Heat and standing water
A roof tank in summer is a warm tank, and the water in it turns over slowly when the household is travelling. Warmth and stillness are the conditions a wall film likes most. This is why a tank is better cleaned before the hot months than after them, and why a home that has been closed for the summer should have its taps run for a good while, and its tank looked at, before the water is used for drinking and cooking. Our home maintenance calendar places the tank clean in the run-up to summer for that reason.
Light matters too. Algae need it. A translucent tank, or one with a missing cover, lets in enough for a green tint to develop on the walls, while a tank that is opaque and closed does not give algae a start.
What the cleaning and disinfection involve
Whoever does the work, the sequence is the same, and each step is there for a reason. The outline below follows the general procedure in the official code and the steps on our own service page.
- Confirm the tank and the access. Size, material, whether it is on the roof, at ground level or underground, where the lid is and where the drained water can go. This is settled when you book, so the right equipment and time are planned.
- Isolate. The inlet valve is closed and the outlets are shut and tagged so that nobody reopens them while someone is working. The pump is switched off so that it cannot run dry.
- Drain. The stored water is run down or pumped out. The code's guideline is to close the inlet about a day ahead so that the household uses most of the water and little is wasted.
- Inspect. With the tank empty, the walls, floor, joints, lid and fittings are checked for sediment, film, corrosion, cracks and failed lining before anything is disturbed.
- Remove the sediment. Sludge on the floor is lifted out, and it is taken away as waste. It is not washed down the outlet into the home's pipes.
- Scrub. The walls, floor, underside of the cover and the fittings are brushed or pressure-washed to break the film that rinsing alone leaves behind.
- Rinse and drain the dirty water.
- Disinfect. A disinfectant suitable for drinking water tanks is applied to every internal surface and left for the contact time the product needs. The code specifies food-grade products for this step.
- Rinse again and drain, so that no strong disinfectant goes to the taps.
- Check the pump, the float valve, the lid, the vent and the overflow screens, refit them, and refill the tank with fresh water.
What our visit includes
Our published scope is draining, sediment removal, disinfection with products suitable for a drinking water system followed by a thorough rinse, a pump inspection and an inspection report after every visit. The technician shows you the emptied, cleaned tank before it is refilled, and shows you the lid and vent screens back in place. The pump is checked for wear caused by sediment, and the report records the tank's condition and the work carried out.
Keep the report. It is the record the code expects an owner to hold, it answers the next tenant's or buyer's first question, and it tells the next crew what was found last time.
A ground tank and a roof tank together
Many villas fill a ground or underground tank from the mains and pump from there to a roof tank. Where the two are connected, the lower tank is cleaned first. Doing it the other way round means refilling a clean roof tank with water drawn through a dirty one. Both tanks, the pump and the pipe between them are one system, so tell us about every tank on the property when you book.
Sampling and testing
The code provides for water samples to be taken after cleaning and tested by an accredited laboratory where contamination is suspected or an inspector asks, and always for certain tanks, including concrete tanks at or below ground level and the very largest. Results take a few days, and a tank in regular use normally goes back into service in the meantime. If your building needs a test result or a compliance document after the clean, say so when you book, because it changes what has to be arranged.
Why this is not a job to do yourself
A water tank is a confined space. The air inside a closed tank can be short of oxygen, which is why the official procedure calls for the tank to be vented and the air tested before anyone goes in, and why nobody should work inside one alone. Add a roof edge, a wet ladder, a pump with mains power beside it and disinfectant in an enclosed space, and the reasons multiply. Do not enter a tank, do not lean into one, and do not climb to a roof tank to look. Lifting the lid of a ground-level tank to look in from outside is as far as a resident should go.
The notice to residents: what it should say
If you manage a building, the notice is part of the job, not a courtesy. The official code tells the owner or manager to notify all residents two days before a planned clean, to deliver the notice to each door and post it at the building's common entrances, and to provide it in Arabic and English, with other languages where they are needed. It also asks for the work to be done in normal working hours as far as practicable.
A notice that does its job is short and answers the questions people will otherwise ring the office to ask.
- The date, and the time the water will go off.
- How long the supply will be off, and the time it is expected back.
- Which tanks or which parts of the building are affected.
- What to do beforehand: store water, finish laundry, and so on.
- What to do when the water returns: run the taps before drinking or cooking.
- The name of the company doing the work and a number to call at the management office.
The second notice
The code asks for a second notice when the work is finished. It should say that cleaning and disinfection are complete, when the water is safe to use for household purposes, and what precautions to take first. The example the code gives is letting taps and showers run for at least five minutes after cleaning, or following whatever the cleaning company advises.
If an inspection or a water test ever fails, the same code requires residents to be told promptly, by notice in the common areas and on each door, not to drink the water or cook with it until the tank has been cleaned again. A resident who sees such a notice should take it literally.
What residents should do on the day
The inconvenience is a few hours without water. A little preparation the evening before removes most of it.
The evening before
Ten minutes the evening before is enough. Expect the pressure to drop before the crew arrives if the inlet has been closed early to run the tank down. That is intended.
- Fill bottles or jugs with drinking and cooking water for the day, and keep them covered.
- Fill a couple of buckets for flushing toilets and washing hands. A toilet can be flushed by pouring a bucket into the bowl.
- Run the washing machine and the dishwasher, and take showers, before the cut-off time and not during it.
- Clear the way to the tank and the pump: stored items on the roof, a locked roof door, a car parked over an underground cover.
- Find last time's report, if there is one, and leave it out for the crew.
- Tell the household, the helper and the gardener, so that nobody opens a tap or switches the pump on in the middle of the work.
While the water is off
The crew needs three things from the property: safe access to the tank and its lid, the supply valve, and somewhere for the drained water to go. The household's part is mostly to leave things alone.
- Switch the water heaters off at their wall switches. A heater should not be left heating while its supply is interrupted.
- Leave the taps closed. An open tap lets air into the pipes and floods a basin when the water returns to an empty home.
- Do not start a washing machine or dishwasher. They will stop mid-cycle with a fault.
- Keep children and pets away from the open tank, the hoses and the pump.
- In a villa, have an adult at home who can let the crew onto the roof and look at the tank when asked.
When the water comes back
The pipes are full of air and of whatever the work has loosened, so the first water through each tap goes down the drain. Work through the home in this order.
- Open the cold taps one at a time, starting with the one nearest the tank or the lowest in the home, and let each run. Sputtering and bursts of air are normal for the first minute.
- Run each cold tap and shower for at least five minutes, or for as long as the crew advises, before you drink the water or cook with it.
- Flush each toilet once or twice.
- Run the hot taps until the flow is steady and free of air. Then switch the water heaters back on.
- Unscrew the aerators on the kitchen and basin taps by hand, rinse out any grit and refit them. Do the same for the shower head if the spray is uneven.
- Rinse or replace the cartridge in any under-sink or whole-house filter. It has just caught whatever was loosened.
- Run the washing machine only once the taps are running clear, so that grit does not lodge in its inlet filter.
What is normal afterwards, and what is not
Water that looks milky and clears from the bottom of a glass upwards within a minute is full of tiny air bubbles, and it is harmless. A faint smell of chlorine for the first hours is the last trace of the disinfectant and fades as the tank turns over. Grit, colour or a strong smell that persists after a thorough flush is not normal, and the company that did the work should hear about it the same day.
Signs a tank needs attention between cleans
Some signs call for a clean. Others call for a repair, because cleaning a tank that cannot keep dirt out only resets the clock for a few weeks.
| What you notice | What it suggests | What to do |
|---|---|---|
| Smell or taste when a tap first runs | Sediment or wall film in the tank | Book a clean |
| Grit in aerators, tinted water | Sediment being drawn into the pipes | Book a clean; check the lid |
| Pressure falling over weeks | Sediment at the pump, or a pump fault | Have the pump checked |
| Insects or larvae in stored water | Open lid, torn vent or overflow screen | Clean, and fix the opening |
| Green tint on the walls | Light getting into the tank | Clean, and fit a proper cover |
| Tank overflowing or never filling | Float valve stuck or failed | Plumbing repair |
| Damp patch or drip under the tank | Leaking joint, fitting or shell | Plumbing repair, soon |
| No record of the last clean | Unknown | Treat as overdue |
Repairs around the tank
A float valve that no longer shuts off, a weeping outlet, a cracked lid and a pump that hums without pushing water are repairs, not cleaning. They are handled under our plumbing service, and the sensible time to do them is the same visit, while the tank is empty and open. Warm water from the cold tap in summer, on the other hand, is not a fault. A tank on a roof in August heats up, and no amount of cleaning changes that.
What to tell us, and what it costs
Tank cleaning is one of our maintenance services, and like most of them it is quoted, not priced from a list. A small plastic roof tank and a large concrete tank under a driveway are different jobs. The quote depends on the tank's size and the access to it, and it is agreed before any work starts.
- How many tanks there are, and where each one is: roof, ground level or underground.
- The rough size of each. The capacity is often moulded or printed on the side of a plastic tank.
- What each is made of, if you know.
- How the roof or the cover is reached, and whether there is a parapet.
- When the tank was last cleaned, and anything you have noticed in the water.
- Whether you need a water test or a document for the building or the landlord afterwards.
- Photos of the tank, the lid and the pump, taken from where it is safe to stand.
Cost and payment
We do not publish a price for tank cleaning, and any figure we gave here would be wrong for most tanks. The things that move the quote are the capacity, the access, how much sediment has built up, the number of tanks, and whether a full report is required for compliance purposes. You receive the quote from your description and photos, or after a free inspection where the tank has to be seen first.
Payment is online by card, from My bookings on this website once the price is confirmed. Every price we quote includes VAT. If you are booking a villa clean for the same week, have the tank done first, so that the home is cleaned with fresh water and the dust from the roof work is dealt with afterwards.
Common questions
Is the water safe to drink straight after a clean?
Once the tank has been rinsed and refilled and you have flushed the taps as described above, the water is the same mains water as before, stored in a clean tank. The disinfectants used for this work are chosen because they are suitable for drinking water systems, and the rinse is there to remove them. If the crew or the building's notice gives a specific instruction, such as waiting for a test result, follow that instruction over any general rule.
How long will the water be off?
For as long as it takes to drain, clean, disinfect and refill. Our service page gives two to four hours for a standard villa tank. Larger building and commercial tanks can take half a day or more, and a property with several tanks may be split over more than one day. The time is confirmed in advance for larger systems, and in a building it should be on the notice.
Does a new or recently fitted tank need cleaning?
Yes, before first use, and that is normally part of the installation. A new tank has been stored, transported and drilled for its fittings, and building dust gets into everything. If you move into a new villa and cannot find out whether the tank was disinfected after installation, have it done once, and start your schedule from that date.
Can I pour a disinfectant into the tank myself between cleans?
No. Disinfecting a tank means treating clean surfaces with a measured amount of a suitable product and then rinsing it away. Pouring a household product into a full, dirty tank does neither. It does not remove the sediment, the amount is a guess, and the household then drinks and bathes in the result. If the water worries you, stop using it for drinking and cooking and book a clean.
I have a water filter. Do I still need the tank cleaned?
Yes. A filter treats the water at one tap, or at the point where it enters the house, and everything it catches came from the tank. A dirty tank shortens the life of the cartridge and still feeds the showers, the washing machine and the water heaters. The filter and the clean do different jobs.
Do you also clean septic or sewage tanks?
That is separate work with separate equipment. Mention it when you book, and we confirm whether it can be handled in the same visit or needs its own date. A drinking water tank and a sewage tank should never be cleaned with the same hoses or pumps.
How to book a tank clean
Book on the website or in the IHR Dream app, describe the tank and attach photos. We confirm the scope, the time the water will be off and the price before the visit. Tank cleaning is scheduled work, so choose a day when the household can manage a few hours without water, and tell the neighbours if you share a tank or a pump.
We work every day from 8 AM – 8 PM, and you can cancel or move a booking free of charge up to 6 hours before the start time. The water tank cleaning page lists what the visit includes, and the areas we serve page shows where we work. When you are ready, book a visit.
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