Thursday, 12 September 2013

It takes four litres of water to make a one-litre bottle of water

Apparently. According to some people on a radio programme talking about a Stephen Emmot's book 10 billion.

I was just as shocked and horrified as you are. Then I started thinking about the alternatives.

Reusing a bottle is a great idea. Much better than buying a new one.  PET bottles are perfect for reuse. They're good for recycling too, but recycled PET goes to other uses rather than making bottles, since health and safety regulations prevent post-consumer recycled waste from being used on food and drink packaging. This is strange when you think that they've been using recycled glass for years, and they are quite happy to let us use recycled trees and recycled oil. Anyway, recycling is not going to reduce the amount of oil used to make new PET bottles. It could even use more energy by providing cheap resources to make other products we didn't know we didn't need, thrust onto the market with an eco label, because they are supporting recycling.

So reuse is definitely better than buying a new bottle. But back to the four litres of water, how many litres of water does it take to reuse a bottle? Remember you have to wash the bottle before refilling it. Who knows how many litres of water a trip to the doctor would take if you didn't, and somebody got sick as a result! Tap water flows at around 0.1 litres per second, so the litres quickly start clocking up. Don't forget to wash your hands too. And wring out the cloth you used to wipe the bottle.

Or you could just use a cup. Bottled water, at least in English-speaking countries, wasn't invented until the 1980s. Before then it was a quaint and derisable habit of continentals, whose primitive urban planners allegedly hadn't mastered plumbing. Then it was the preserve of yuppies and source of scorn to pour upon them. And now we are all buying water, left right and centre, and carrying it around wherever we go. So do we really need all this water? Has the world got more thirsty? Or is this just a result of beverage producers such as Coca Cola measuring their success by the percentage of human fluid consumption that they supply? Or is it part of a space programme, ensuring that there is a massive supply of water, ready and packed to send off in the escape pods?

Even using a cup is going to consume more than a litre per litre because you still have to wash it. Another thing we tend to do when getting water from the tap is to let it run for a while, and this is going to use more water too. I know you could be letting the water run while rinsing out the bottle, but the chances are you start filling the bottle after rinsing it, then realise that you didn't let the water run before that, so you need to rinse it out again.  A minute later the tap is still running, and that's six litres, mostly down the drain.

And the chances are that if you get a cup you could end up with a jug, which needs washing too, and if there's a jug people may start putting ice in it. And maybe a slice of lemon. 

So, it takes four litres of water to make a one-litre bottle of water, does it?

Well, that's not too bad. I wonder when they can reduce that to three litres?