No. Don't drink tap water straight from the tap anywhere in Thailand, including Bangkok. Bangkok's water utility, MWA, says its tap water meets the Department of Health's drinking-water standards, which are based on World Health Organization (WHO) guidelines. But rooftop tanks and old pipes inside buildings can contaminate it before it reaches your tap. That's why many Thais drink bottled water or water from refill machines.
By Emily, WaterWell travel writer. Last checked: 9 November 2026
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Thailand tap water: quick facts
| Question | Answer |
|---|---|
| Drink from the tap? | No. Drink bottled, refill-machine or treated water |
| Brush your teeth? | Use bottled or filtered water |
| Ice? | CDC advises avoiding ice. If you have it, choose factory tube ice from sealed bags |
| Restaurants | Order bottled water, or ask for “nam plao” (plain drinking water) |
| Refills | Reverse-osmosis refill machines outside shops and apartment blocks |
| Who supplies the water | Metropolitan Waterworks Authority (MWA) in Bangkok, Nonthaburi and Samut Prakan; Provincial Waterworks Authority (PWA) and local councils elsewhere |
Is the tap water safe in Bangkok, Phuket and Chiang Mai?
The answer is the same everywhere: don't drink it straight from the tap.
| Place | Drink from the tap? | Why |
|---|---|---|
| Bangkok | No | MWA says its water meets Department of Health standards; building tanks and old pipes are the risk |
| Chiang Mai | No | PWA mains, with the same tank and pipe problems |
| Phuket | No | PWA and local supplies, with the same tank and pipe problems |
| Pattaya | No | PWA mains, with the same tank and pipe problems |
| Koh Samui, Koh Phangan, Koh Tao | No | Island supplies vary, so treat it like any Thai tap water |
| Villages and national parks | No | Wells and rainwater may be untreated |
Why don't Thais drink tap water?
Most of the risk is in the last few metres of plumbing. The utility treats and tests the water, but most buildings store it in rooftop or ground tanks, which aren't the utility's responsibility. An MWA study found E. coli in 1.1% of tap samples but in more than 8% of storage-tank samples (Khaosod English). That's why many Thai households drink bottled water, 20-litre refill jugs or water from reverse-osmosis machines instead.
Are the water refill machines safe?
Yes, when they're looked after. The vending machines outside shops and apartment blocks filter mains water by reverse osmosis, and you fill your own bottle for about 1 baht a litre. Quality varies: when the Department of Health tested refill machines in 2016, 40% of samples failed its standards (MGR Online, in Thai).
- Check the service sticker. It should show a clean or filter change within the last month or two.
- Look at the nozzle and the area around it. Skip a machine that looks dirty.
- Don't drink water that smells stale, musty or of plastic.
Is ice safe in Thailand?
CDC advises travellers to avoid ice in Thailand (CDC Yellow Book). Edible ice is regulated by the Ministry of Public Health (Notification No. 463, in force since 12 December 2025). Thailand's Department of Health advises choosing factory-made tube ice sold in sealed bags with an FDA number (ChemLinked). If you want to be careful, skip ice, especially from street stalls.
Can you brush your teeth with tap water in Thailand?
Use bottled or filtered water. CDC notes that brushing your teeth with contaminated water can make you ill (CDC).
When is the rainy season, and does it affect the water?
In most of Thailand the rainy season runs from mid-May to mid-October. On the southern Gulf coast, including Koh Samui, it lasts until December. Floods are most likely from August to October and can cut or contaminate supplies. During the November 2025 floods, for example, PWA suspended supply in Hat Yai (Nation Thailand). In a flood, stick to sealed bottled water.
FAQs
Can you drink tap water in Bangkok?
Not straight from the tap. MWA says its water meets Department of Health standards, but tanks and pipes inside buildings can contaminate it. Drink bottled water or water from a refill machine, or treat it first.
Can you drink the tap water in Thai hotels?
No. Use the bottled water in your room, or treat tap water and drink it through a filter.
Are water refill machines safe?
Usually, if the machine is clean and has a recent service sticker. They cost about 1 baht a litre.
Can you shower in Thai tap water?
Yes. Just don't swallow it.
What should I do if I drink tap water by accident?
Most people are fine. If you get stomach symptoms, drink plenty of safe fluids, and see a doctor if they're severe or don't settle.
Sources
- MWA: Consumer Confidence Report 2025 (PDF)
- CDC Yellow Book 2026: Thailand
- CDC: Water disinfection for travellers
- Khaosod English: MWA study on tap and tank samples (2018)
- ChemLinked: Thailand's edible ice regulation
- Nation Thailand: 2026 rainy season and Hat Yai floods