If you run a restaurant, café, hotel kitchen or cloud kitchen in the Kingdom, a Legionella risk assessment is how you find out whether the water behind your sinks, spray arms, ice machines and showers is quietly becoming a breeding ground. The question is sharper here than in Europe. Cold pipes that would stay chilly in London sit at bath temperature on a Riyadh roof in July, much of the supply has travelled hundreds of kilometres from a desalination plant before it reaches your tank, and venues in Makkah and Madinah swing from quiet weeks to round-the-clock service during Hajj, Umrah peaks and Ramadan.
This guide to Legionella risk assessment in Saudi Arabia covers what a proper assessment looks at, the local factors that push risk up, which Saudi rules apply, where UV disinfection fits, and a routine your team can keep.
TL;DR
- Legionella grows in warm, still water. In Saudi heat the cold side is the hard part: tanks and pipes warm past 20°C unless insulated, shaded and kept moving.
- City supply mixes desalinated water and groundwater, usually stored in building tanks. Tank condition and turnover matter as much as the source.
- Published Saudi research has found Legionella pneumophila in Makkah hotel tanks and Legionella DNA in Dammam cooling tower water.
- Municipal rules, the Saudi Building Code and SFDA hygiene requirements all apply. With no dedicated Saudi Legionella procedure found, WHO guidance and ASHRAE 188 are the benchmark.
- A written assessment, a simple log and planned servicing keep the risk low.
Need a Legionella risk assessment, or help with the controls it recommends? Talk to Our Team about your site, the equipment you run and how busy your kitchen gets.
What a Legionella risk assessment in Saudi Arabia covers
A Legionella risk assessment is a written survey of everywhere water is stored, heated, piped or sprayed on your premises, with a judgement on how likely each point is to grow and release the bacteria, and a list of actions to fix it. In a Saudi food outlet it usually starts at the roof or basement tank and ends at the wash-up spray arm, the hand basins and the staff showers.
The bacterium itself is common in natural water at low levels. Trouble starts when a building gives it warmth, stagnant sections and something to feed on, such as scale, sludge or biofilm. People catch Legionnaires' disease, a severe pneumonia, mainly by breathing in fine droplets of contaminated water.
A competent assessor will map the pipework, tanks and heaters, take temperatures at the tank, the heater and the nearest and furthest outlets, open tanks to check for sediment and missing screens, look at spray heads and equipment inlets for scale and slime, and ask how often each outlet is really used. They also list who is exposed: guests, kitchen staff, cleaners and vulnerable visitors. The result is a document you can show an inspector or insurer, with an action plan, owners and dates.
Saudi heat and the cold-water problem
The UK Health and Safety Executive puts Legionella growth at roughly 20°C to 45°C, and the WHO gives 20°C to 50°C with an optimum around 35°C. European cold water usually arrives below that band. Saudi cold water often does not.
Legionella bacteria "live and grow in water systems at temperatures of 20 to 50 degrees Celsius". Source: World Health Organization, Legionellosis fact sheet.
Three things push Saudi cold water into the danger band:
- Rooftop storage. Black plastic or bare steel tanks on a Riyadh or Al Khobar roof absorb sun all afternoon. A tank that holds two or three days of water gives it time to warm through.
- Long horizontal runs. Cold pipes laid through hot ceiling voids, or alongside hot pipes and kitchen extract ducts, pick up heat before they reach the tap.
- Low daytime demand. Many outlets serve mainly lunch and evening trade, so water sits in branches for hours during the hottest part of the day.
The fix is rarely exotic: insulation, shade, sensible tank sizing and moving water. The difference in the Kingdom is that the cold side cannot be assumed safe, and a template written for a temperate country tends to underplay it.
What arrives at your tank: desalinated, blended and stored
Saudi cities rely heavily on desalination. In 2020, desalinated water made up 63 percent of urban water demand, with groundwater supplying 34 percent and surface water 3 percent, according to a 2022 economic brief from the U.S.-Saudi Business Council. Depending on the city and district, premises may receive desalinated water, groundwater or a blend, and some sites top up by tanker.
For Legionella control, what happens inside your building matters more than the source. Disinfectant residual fades as water sits warm for days, sediment from tankered or blended supplies settles at the base of the tank, and differing hardness between sources drives scale in heaters, spray heads and coffee and ice equipment. Scale and sediment both give biofilm a foothold.
So the tank is a control point in its own right. Lids should seal, overflow and vent openings should be screened, insulation should be intact, and the tank should be sized so it turns over regularly rather than storing water for the week. Where scale is building up in your equipment, appropriate pre-treatment protects the kit and removes one place biofilm likes to grow. You can see the dispensing and beverage equipment we look after on our water dispensers and beverage systems page.
Makkah, Madinah and seasonal peaks
In the two holy cities, hotel kitchens and restaurants near the Haram can run almost non-stop during Hajj, busy Umrah periods and Ramadan, then sit partly empty for weeks between peaks.
Both ends of that cycle need planning:
- Before a peak, tanks should be inspected and cleaned if needed, heaters checked, and outlets that have been idle flushed through, so that a sudden surge in demand does not pull stagnant water and loosened biofilm through to the busiest taps and showers.
- During quiet spells, unused rooms and kitchen lines become dead ends in all but name. A written flushing rota for closed floors is one of the cheapest controls available.
A study published in 2021 tested 100 water samples collected in 2014 from ablution water at the Grand Mosque and from hotel water tanks near the Haram. Eleven samples were positive for Legionella pneumophila, and all of the positives came from hotel tanks (Ashgar and Al-Said, African Journal of Microbiology Research). Operators in Makkah and Madinah should treat tank management as a priority, not an afterthought.
Cooling towers and evaporative equipment
Many larger Saudi hotels, malls and food courts are cooled by central plant with cooling towers, and some sites use evaporative coolers. These are classic Legionella sources because they combine warm water with a fine spray that can drift a long way.
Research at a university hospital in Dammam found that cooling tower samples tested negative by conventional culture yet every sample was positive by real-time PCR, with Legionella the most common genus identified (Farhat et al., Saudi Medical Journal, 2018). The authors recommended using both culture and molecular methods for monitoring. Tenants in malls and hotels may not own the cooling plant, but the assessment should still record where it is and who maintains it.
Risk points in a typical Saudi food outlet
| Location | Why it matters in Saudi conditions | Typical control |
|---|---|---|
| Rooftop or basement tank | Warms in the sun, holds water for days, collects sediment | Insulate, shade, seal lid and screens, size for turnover, inspect and clean |
| Cold pipes in ceiling voids | Pick up heat from voids, hot pipes and extract ducts | Insulate, reroute where practical, check temperature at the tap |
| Water heaters and calorifiers | Lukewarm storage or sludge at the base | Store hot, drain and inspect, keep return loops balanced |
| Dead legs from old layouts | Kitchen refits often leave capped branches full of still water | Cut back to the main run during works |
| Pre-rinse spray arms and shower heads | Create the fine mist that carries the bacteria | Descale and disinfect on a schedule |
| Little-used basins, prayer-room and staff showers | Sit unused for days, especially in quiet seasons | Weekly flushing, logged |
| Ice machines, glass washers, combi ovens, beverage systems | Hold or spray water at warm temperatures | Planned servicing, filter changes, inlet checks |
| Cooling towers and evaporative coolers | Warm water plus drift | Specialist water treatment and monitoring by the plant owner |
Ice machines deserve a closer look than most kitchens give them: they hold water, sit in warm rooms and feed ice straight into drinks. Our guide to ice machine filtration in Saudi Arabia explains how inlet filtration keeps scale and sediment out of the machine.
Holding safe temperatures
The WHO advises keeping hot water above 50°C, which means water leaving the heater at 60°C or more, and cold water below 25°C and ideally below 20°C. A correctly set heater usually handles the hot side. The cold side takes more work: insulate every cold pipe in a ceiling void or roof space, shade or replace bare rooftop tanks, keep hot and cold pipes apart, and take monthly readings at the sentinel outlets nearest and furthest from each tank or heater. Where scalding is a concern at guest basins, fit thermostatic mixing valves near the outlet rather than turning the heater down.
If cold water cannot be kept below 20°C in midsummer, the assessment should say so and add compensating controls, such as more frequent flushing.
Which Saudi rules touch your water system
Several Saudi rules apply to a food premises, though none is a dedicated Legionella code:
- Municipal licensing. In August 2025 the Ministry of Municipalities and Housing approved unified requirements for restaurants, cafés, cloud kitchens and food kiosks, issued through the Balady platform. They require compliance with the Saudi Building Code, including ventilation, air conditioning and drainage.
- Saudi Building Code. The Saudi Plumbing Code (SBC 701) governs water distribution, water heaters and fixtures in new and altered installations, so any refit that changes pipework should be designed to it.
- SFDA hygiene requirements. The Saudi Food and Drug Authority's Food Hygiene Requirements say there must be an adequate supply of potable water, that non-potable systems must be kept separate with no backflow into potable water, and that ice in contact with food must be made from potable water and protected from contamination.
We could not find a published Saudi Ministry of Health rule that sets out a specific Legionella procedure for food premises. Until one applies to you, the sensible benchmark is international: the WHO's guidance on legionellosis and water safety planning, and ASHRAE Standard 188, which sets out a risk management programme for building water systems. Check with your municipality and, for hotels, your licensing authority whether anything more specific applies to your premises.
Standards also differ from one country to the next, which matters for groups that operate across the region. Great Britain works to the HSE's ACOP L8 and HSG274, with BS 8580-1:2019 setting out how a risk assessment should be carried out and reported. Dubai has its own municipal guideline, DM-HSD-GU44. In the Kingdom, many assessors borrow from these documents, so ask yours which standard their report follows.
A routine your team can keep
The frequencies below follow the UK HSE's technical guidance (HSG274 Part 2), a widely used reference. Your assessor may tighten them for Saudi conditions.
Weekly
- Flush little-used outlets, including closed rooms and seasonal areas, and log it.
Monthly
- Record temperatures at sentinel outlets and at the heater flow and return.
Quarterly
- Descale and disinfect shower heads and pre-rinse spray heads.
Annually, or sooner where heat and sediment demand it
- Inspect cold water storage tanks and clean them where needed.
- Review the risk assessment, and always after a refit, a change of use or an incident.
On the equipment schedule
- Service ice machines, beverage systems and dispensers, and change filters on time.
Keep these checks in your HACCP records alongside temperature logs and cleaning schedules. If you would rather someone else ran the schedule and kept the paperwork, our Comprehensive Maintenance programme is built for exactly that.
Chemical biocides and other treatments
When heat makes the cold side hard to control, water treatment carries more of the load. The UK's HSG274 Part 2 is a useful guide to the main options:
- Chlorine. Dosing extra chlorine aims for 0.5 to 1.0 mg/l free chlorine at the outlets. It helps stop new biofilm forming but struggles against biofilm that is already established.
- Chlorine dioxide. It reaches into biofilm better than chlorine. The target is 0.1 to 0.5 mg/l at outlets. It tends to gas off in hot water, so the dose point needs thought.
- Copper and silver ionisation. Electrodes release copper and silver ions that work in both hot and cold water. Hard water can coat the electrodes, so they need regular cleaning.
- Silver stabilised hydrogen peroxide. Injected into the supply and validated against the maker's instructions.
- Ozone and UV. These work only where they are fitted and leave no residual in the pipes beyond.
Each method needs a dosing check at least weekly and regular readings at sentinel outlets. Cooling towers are a separate case: they need their own treatment programme, run by a specialist for the plant owner. Ask your assessor which approach suits your water, your building and your equipment.
Where UV disinfection fits
UV disinfection treats water as it flows past a UV-C lamp, damaging the DNA of bacteria so they cannot multiply. It adds no chemicals, which suits kitchens and hotels that want to avoid taste or handling issues, and it needs no contact tank. UV does not leave a residual in the pipework downstream, so it supports the controls above (temperature, flushing, tank care) rather than replacing them. A typical position is on the supply after the storage tank, or at a single outlet such as a dispenser or ice machine feed.
For the trade-offs against chlorine and other chemical methods, see UV disinfection vs chemical treatments. Our SovSafe UV range covers whole-supply and point-of-use units:
UV lamps lose output with age, so they need replacing on the maker's schedule, and the quartz sleeve must stay clean for the light to reach the water. Both can sit on the same service visit as your filter changes. Request a Quote with your flow rate and the outlets you want to protect.
Where Sovereign Water fits
We work on the water side of Saudi food and hospitality sites: the incoming supply, its treatment and filtration, and the dispensing, beverage and ice equipment that relies on it. The scale and stagnation that damage a coffee machine or ice maker are the same conditions that help biofilm take hold, so the two jobs overlap.
We also carry out Legionella risk assessments for food outlets, hotels and offices in Saudi Arabia. We walk the system with you, take temperatures, review your existing records and give you a written assessment with a clear action plan. We then recommend treatment and equipment suited to your water and your trade pattern, install it, and keep it serviced and documented through Comprehensive Maintenance, including planned sanitising of the dispensers and equipment we look after. For operators with several sites across Riyadh, Jeddah, Dammam or the holy cities, that gives one set of records and one point of contact. Get in Touch to talk about your premises.
Questions Saudi operators ask
Is a Legionella risk assessment a legal requirement for Saudi restaurants?
We have not found a Saudi regulation that names a Legionella risk assessment as a specific requirement for restaurants. Food premises must still meet municipal licensing rules, the Saudi Building Code and SFDA requirements on potable water and ice, and a documented assessment is the recognised way to show you are managing water safety. Confirm the current position with your municipality.
Our cold water is warm in summer. Is that a problem?
It can be. Legionella grows from about 20°C upwards. If cold water at your taps reads above that, look at tank shading and insulation, pipe routes through hot voids, and how long water sits before use.
We are in Makkah and close floors outside the season. What should we do?
Put closed areas on a written weekly flushing rota, and before reopening, inspect and clean tanks as needed and flush every outlet through. Published research has found Legionella pneumophila in hotel tanks near the Haram.
Does UV disinfection stop Legionella on its own?
No. UV treats the water passing through the unit but leaves no residual in the pipes after it. It works alongside temperature control, flushing and tank management, not instead of them.
Who is responsible in a mall or hotel unit?
Usually both parties. The landlord or hotel owner typically controls central plant and shared tanks, while the tenant controls the kitchen's own pipework and equipment. Your assessment should record who owns each part.
Sources
- World Health Organization, Legionellosis fact sheet (growth at 20°C to 50°C, optimum 35°C, aerosol transmission, hot and cold water temperatures, accessed 3 October 2026): https://www.who.int/news-room/fact-sheets/detail/legionellosis
- UK Health and Safety Executive, Legionnaires’ disease: what is it? (20°C to 45°C growth range, accessed 3 October 2026): https://www.hse.gov.uk/legionnaires/what-is.htm
- UK Health and Safety Executive, HSG274 Part 2, Legionnaires' disease technical guidance (checking frequencies and biocide target levels, accessed 8 October 2026): https://www.hse.gov.uk/pUbns/priced/hsg274part2.pdf
- British Standards Institution, BS 8580-1:2019 Water quality. Risk assessments for Legionella control. Code of practice: https://knowledge.bsigroup.com/products/water-quality-risk-assessments-for-legionella-control-code-of-practice-1
- Dubai Municipality, Technical Guidelines for Legionella Control in Water Systems, DM-HSD-GU44: https://dmpmedia.dm.gov.ae/uploads/2022/11/DM-HSD-GU44-LCWS2_Technical-Guidelines-for-Legionella-Control-in-Water-System_V3.pdf
- ASHRAE Standard 188, Legionellosis: Risk Management for Building Water Systems (accessed 3 October 2026): https://www.ashrae.org/technical-resources/bookstore/ansi-ashrae-standard-188-2021-legionellosis-risk-management-for-building-water-systems
- Ministry of Municipalities and Housing, unified requirements for food establishments, announced 10 August 2025 (accessed 3 October 2026): https://momah.gov.sa/en/node/15042
- Saudi Building Code, The Saudi Plumbing Code (SBC 701) (accessed 3 October 2026): https://sbc.gov.sa/En/BC/Pages/BuildingCode/BCDetails.aspx?codeId=701&year=2024
- Saudi Food and Drug Authority, Food Hygiene Requirements, Chapter VII Requirements for Water Supply (accessed 3 October 2026): https://www.sfda.gov.sa/sites/default/files/2020-12/FoodHygieneRequirementsEn.pdf
- U.S.-Saudi Business Council, Saudi Arabia's Water Sector, February 2022 (urban water by source, 2020, accessed 3 October 2026): https://ussaudi.org/wp-content/uploads/2022/02/Water-2022-Economic-Brief.pdf
- Ashgar S.S. and Al-Said H.M., Detection of Legionella pneumophila as the cause of atypical pneumonia in the water sources of the holy places of Makkah, African Journal of Microbiology Research 15(8), 2021 (accessed 3 October 2026): https://academicjournals.org/journal/AJMR/article-full-text/0F1F35867559
- Farhat M. et al., Legionella confirmation in cooling tower water, Saudi Medical Journal 39(2), 2018 (accessed 3 October 2026): https://smj.org.sa/content/39/2/137
Next step for your kitchen
Tell us where your premises are, how your water is supplied and stored, and which equipment you run, and we will suggest a practical next step for your site. Talk to Our Team.
