How do you know what’s the most environmentally friendly way to wash dishes? You ask one of those nifty books that advise you of the “greenest” options for all the ordinary elements of quotidian life.
Except.
These books invariably (in my experience to date) recommend using a dishwasher instead of hand washing, as it uses less water. Which seemed odd to me – right up until I read the dishwashing section of How To Save Your Planet One Object At A Time by Dr Tara Shine.
This starts – as is usual on these occasions – by suggesting that you use a dishwasher. It then explains that this is because “manual dishwashing can use an average of up to 50 litres of water….per wash.”
Setting aside for a moment the combination of “average” and “up to” – not how averages worked when I was at school – FIFTY LITRES OF WATER!
I wash dishes in a washing-up bowl (a squarish plastic bowl that fits in the sink). When full, it holds five litres of water – only a tenth of the average up-to. Five litres once a day is still only 35L in a week.
All of which leads me to two questions. One: how in the name of sweet green apples do you use 50L of water for a single load of dishes? And two: why do the people who write eco books assume that this is how everyone does it?
In the interest of scrupulous fairness, I must admit that I didn’t count the water used in running the tap to hot, something which the dishwasher with its 6.5L doesn’t need to do.
On the other hand, 6.5L is the amount given for a “new, efficient” dishwasher, and that doesn’t include the washing of anything you own that isn’t dishwasher safe. Or any rinsing you do of things you don’t think the dishwasher will quite manage to get clean unaided.
The book also includes the “average of up to” for time used in washing dishes by hand. Sixty minutes. Sixty! That’s a full hour per load!
I don’t know who these poor souls are who are spending more than 4% of their mortal span washing their dishes in half a bathful of hot water, but it seems to me that staging an intervention would be more appropriate than recommending they buy a dishwasher.
For one thing, a 5L dish bowl doesn’t produce a hulking pile of e-waste every 7-10 years – and that’s got to be good for the planet.
How do you wash your dishes – and have you ever managed to use 50L in one go?
Yes!
And: studies can’t just count the water and energy used in one wash. The water and energy used to produce the dishwater count, too. Including shipping parts around the world, trucks going to customers; and then all the way back again at the end, when the dishwater can not be fully reused or recycled because it has not been designed that way, and precious raw materials are lost because the economy is still a sad long way from being circular. But even in a circular economy, (re)production will take lots of energy.
So, yes: handwash is likely to win! at least in private households.
As for the 50L: if you wash dishes under running water, keeping your tap open all the time, you might eventually even get your bathtub filled…
So that’s probably what that very neutral study assumes that people on average are up to.
Production and shipping too – good point!
It’s hard to believe that all the eco-experts are assuming constant water running is the norm (so much so that they don’t even discuss alternatives), and yet what other explanation is there?
I also wash my dishes by hand in the sink and I am sure I use nowhere near 50L. And after the dishes are done, the water is then used to irrigate the plants in pots by my front door, which you can’t do with a dishwasher. (And do I get bonus points for using bar soap in a shaker rather then detergent in a plastic bottle?)
Bonus points indeed! Both for the bar soap (more eco-friendly as you’re not shipping water content about) and for the water reuse.
I have considered schlepping bathwater down the stairs like a Georgian housemaid, should water restrictions come into force, but so far this summer most of the watering has been done effortlessly by the heavens.
When I was in Sydney for Christmas a while back, I think the house I was in had “grey water” (including from a dishwasher, I think) piped into the garden, so as to legally water it during a dry summer.
Nifty! And worth considering, the way things are going.
I also wash by hand, filling a gallon tub about halfway with only a few drops of eco-friendly soap; I pile everything face-up so that I can rinse it quickly, turning off the water before I turn everything face-down to drain.
Unfortunately, however, as much as this may be an advantage over a dishwasher, there are many days that I simply can’t wash dishes at all, at which times we are compelled to eat from disposable paper plates. But they don’t use ANY water :).
They certainly don’t use any to wash! But we each do our best in the circumstances we find ourselves in.