Maybe I should have called this page How to avoid Montezuma's Revenge... although drinking contaminated water can make you far sicker than that.
Drinking water safety: it's one of those things you might not think about until you're locked in the bathroom feeling like the world is ending.
Making sure your drinking water is safe is a foundational part of travel - you can't just wing this one.
Drinking tap water is deemed unsafe in a number of regions:
To confuse things more, some countries may have perfectly safe drinking water in major cities and resorts but undrinkable water everywhere else.
Always ask someone local, or look it up before drinking.
If you have any doubt at all about the tap water, don't drink it. In fact, don't drink ANY water you don't trust.
So what can you drink?
There's obviously bottled water but you can also boil your water, treat it chemically, use UV light on it or filter it physically. Lets look at these more closely.
This is often the simplest solution. But it comes at a cost.
Bottled water is expensive, and bottles are wasteful.
If you're traveling solo for two weeks where the water is unsafe, you'll use at least 21 liter-bottles of water: you'll drink one liter a day and use the rest for all your other needs.
A cheap option is to boil your water, but be sure to let it boil at length.
Some people say one minute is enough (unless you're at a high altitude, in which case you need longer) but I don't take any chances and let it boil plenty.
Filter the water before boiling it to get rid of any sediment or visible specks. Then let it cool before drinking (skip this step at your own risk - and find out what a tongue blister feels like).
Or why not make a nice cup of tea or coffee with that boiled water?
However - boiling isn't always feasible or convenient.
Water purification tablets are made from a variety of chemicals:
The problem with iodine and chlorine is that they also exist in strengths never intended for water purification. Using these stronger doses can lead to overdose and death.
To keep yourself safe, use products sold exclusively for water purification and follow instructions to the letter. Do not improvise!
Take note: iodine is dangerous for pregnant women, if you have thyroid problems, and a few other conditions so read up about it.
On occasion I've tried tablets like Micropur (chlorine dioxide) or Potable Aqua (iodine). In the case of chlorine dioxide, it's not instant: you'll have to add it to the water some time before you drink it.
You'll use more tablets than you think, so calculate properly: some doctors recommend drinking between 2-6 liters (very roughly 4-12 pints) of water each day so a small pack of tablets won't go very far and they're quite expensive.
Some treatment products come in concentrated drops as well. If you have a choice, opt for the tablets - they won't leak, they're lighter, and they won't break so you can carry them around in your pocket.
The top of the line are purifiers that use ultraviolet light, which can get rid of almost anything, even viruses. They don't use chemicals and they tend to be easy to use.
Several of my travel friends swear by the SteriPEN: you stir clear water with the wand and it kills pretty much everything that's bad for you. It's light and easy to carry and uses AA batteries, available almost anywhere. If you're traveling off the beaten path, play it safe - things do break - also take along a few tablets.
One thing though - it's a piece of kit so don't forget to read the instructions! Otherwise you may end up drinking dirty water that will make you sick.
Dying of thirst and have absolutely nothing with which to purify or clean water?
This happened to me in the Brazilian rainforest and here's what I did.
I had no way of boiling water so I took a chance. Desperate with thirst, I used my T-shirt to filter water straight from the Amazon River.
I was lucky and nothing happened but I shudder when I think of it because I could have been extremely ill. Remember, the T-shirt will only filter out the mud and sticks, not the bugs or bacteria. The water is still bad - it just looks a little less bad.
Make sure this never happens to you: be equipped.
The Katadyn Water Bottle actually filters and purifies water as you drink it. It comes in several versions, ranging in price from reasonable to expensive.
You'll also need replacement cartridges and filters, depending on the length of your trip.
Don't think of this bottle as a one-time travel purchase: it could come in handy at other times. If your home water supply ever goes down for some reason or your area is affected by a natural disaster, you'll be awfully happy you bought a quality water filter.
Before you use any purifiers, whether filters or pills or anything, make sure your water is as clear as possible. Use a T-shirt, a bandanna, a coffee filter, anything you can get your hands on.
Whatever you decide to buy, get a backup in case your primary water purifier fails.
And don't forget to test your equipment before you go! You'll want to know how it works, and if there's a problem, you'll be able to solve it in time.
Here are the criteria I'd use when shopping for a filter or purifier:
No water available?
You don't have to die of thirst: drink reputable packaged fruit juices, sodas, sparkling water, or coffee or tea, since boiled water is safe. If you have a sensitive stomach, beware of freshly squeezed juices: they might be diluted with tap water, sugar is a breeding ground for bugs, hands and machines must be kept clean... not an easy task so I'd skip them if you're uncertain.
As I traveled across Africa, there was one drink I found everywhere, and I mean absolutely everywhere: Coca-Cola (as long as you tolerate sugar, of course).
Beware of cocktails - they could have water, ice and those iffy fruit juices. You'll be pleased to know wine, beer and spirits are safe when it comes to water (although dehydration and drunkenness could be side effects). Please note: alcohol drunk after ingesting dirty water will not retroactively kill bugs.
Don't forget the issue of food when thinking of water. Here are a few things to be aware of when traveling to destinations with water you can't trust:
So you've been careful - but you still got sick.
I'm not a doctor so I won't give you medical advice BUT: if you get sick from water, take it seriously, especially in a hot, dehydrating climate.
How will you know if you're sick because of the water?
You'll probably develop nausea or vomiting, you may have a fever or diarrhea, and you might feel aches and pains, or stomach cramps. If you can, get to a doctor right away. This is even more important if you're older or have special health problems or if this happens to an accompanying child. (You DID get travel health insurance, right?)
If getting to a doctor immediately isn't an option, rehydrate! Drink plenty of clear fluids or better yet, use oral rehydration salts (ORT). I always carry a few packets when I travel, just in case, and in the mountains of Uganda, far from any health care, I nursed myself back to health with these.
No ORT? Don't worry, the mixture is easy to make: take 1 liter - about 5 cups of bottled or sterilized water, and add 1 teaspoon of salt and 8 teaspoons of sugar. Drink it slowly, taking little sips. You can easily get these at your mountain or travel shop, or from places like Amazon.
A word of caution though - there is a lot of debate about ORT and like everything you can cause problems in trying to solve them. If there's any possibility at all, get professional help.
A final word: if you're in the Alps or other pristine environment and you come across a crystalline stream, don't assume the water is potable. A rat, mouse, fox or other animal may have peed in it further upstream. This could make you very ill so purify any water, or play Russian roulette with your health.