Carbon Footprint of Tap Water
by Matthew Sparkes, London, UK on 08. 2.07
No, we're not saying that water is something to avoid. But, out of curiosity, what is the carbon footprint of tap water? This was the question posed to the Guardian today by a reader, "Watching those pictures of water being pumped out of flood-stricken areas got me thinking: how much energy does it take to produce all our mains water?"
Leo Hickman explains that every day the UK uses 19 billion litres of tap water, and every year we use seven cubic kilometres. I know that's an odd metric to use, but think about it - that's enormous. Of course, much of this is wasted, either through leaking pipes or by us, in our houses.
Processing and serving us water uses between 2 and 3% of all electricity in the UK, and creates 0.5% of our carbon emissions. Crunching these considerable numbers, Hickman concludes that a litre of water has a footprint of 0.298 grammes, and says, "even if you had one very full bath - about 150 litres - every day for a year, overall it would represent just 15kg of greenhouse gas emissions. That's about what the average car produces over 80 kilometres."
However, if you add the cost of heating that water, and the fact that the country is often in periods of drought, then it still makes sense to use as little water as possible. ::The Guardian ::Image Source
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Gee, isn't there a cost associated with treating those 7 cubic km of water after it goes down the drain? Isn't this only half the story?
Yeah, this is only half of the story. But I couldn't imagine it costing much more to process the water than it does to produce and transport it.