There aren’t many countries in Southeast Asia where you can drink the tap water.
Malaysia has the safest water supplies but elsewhere you should either buy bottled water or use a filter. Standards are lowest in Cambodia and Laos (see the Worldwide Rating of Drinking Water Safety for more details).
Finding bottled water is not a problem and it’s cheap. In every small town you should be able to find water in 1 litre plastic bottles at a minimal cost. In Laos, these bottles are sold in packs of six for 7,000 kip – less than one dollar. The price is similar in Thailand and Cambodia. Occasionally in Cambodia we could only find small bottles of water – about 300ml each – and they are a bit more expensive.
The only problem with bottled water is the waste. Two cyclists in humid southeast Asia can easily drink 8 litres of water a day. If you have a water filter, you’ll save yourself a bit of money and the world a lot of plastic. Often there’s nowhere to dispose of the plastic bottles so you either have to hold on to them until you reach a town or leave them by the side of the road.
The other option is to filter water, although that does take time. We spent about half an hour each evening filtering our daily water with our MSR Miniworks EX water filter: about 8 litres of water split between bottles mounted on the bike frame and our Camelbak Unbottle 70 bladders. Every filter is different and will process water at different rates and qualities.
If you don’t have a water filter already, the cost of buying one is likely to outweigh the cost of buying bottled water on a smaller tour. We bought ours with a world trek in mind, knowing that sometimes we would need to use it, unlike in Southeast Asia where bottled water is always available.
In Thailand, you have a third option and that is to use the water dispensers found in most towns. They are tall, white plastic machines that look a bit like a soft drink vending machine. They can be hard to spot but you’ll often find them beside convenience stores or laundromats. For about 1 baht a litre you can quickly fill up all your bottles with cold, filtered drinking water.
At the beginning we drank tap water and never got ill but some locals warned us there might be heavy metals in the water. Refilling at the water machines might be a better idea. -Laetitia and Sebastien
Don’t worry about the water and ice you get in restaurants, whichever country you’re in. As long as its not hand-shaved ice (rare to see in restaurants), it’s always purified and safe to consume so indulge in those fruit shakes and ice coffees to keep cool!