Monday 23 March 2015

Permaculture everyday: washing the dishes and saving water

by Michael Hutchinson

I don’t remember why I was having a blood sample taken but can still recall the moment when the nurse dropped the tiny glass phial. There was only a very small amount in it, but suddenly blood seemed to be spattered everywhere. I thought I’d found myself in an out-take from a slasher movie.

What’s this to do with washing dishes or permaculture? Well, nothing at all, really. Except that small things are not to be under-estimated. Small things like washing dishes.

Reduce, reuse, recycle


Thinking about this - and it’s not something I’ve dwelt at length on, to be honest - the recycling mantra springs to mind: ‘Reduce, reuse, recycle.’ This chimes well with the three ethical principles of permaculture, in particular Earth Care. 

And as I was to find out, dish washing can, depending on how you approach it, touch on five of the design principles as well (catch and store energy, obtain a yield, use and value renewable resources and services, produce no waste, use small and slow solutions).

It makes sense to start by considering whether we need to wash the dishes at all. At my home we typically do wash dishes three times a day: after breakfast; after lunch (if at home); then again in the evening. We could do this less often but it's to do with the lack of space in a very small kitchen where a few dishes can look like a whole pile.

While I haven’t always saved water all year round, I collect what I think of as run-off through spring, summer and into the autumn: this is what comes out of the tap before it's hot enough to use. Adding some rainwater collection to this has meant that I’ve never had to resort to watering the garden by deliberately using tap water.

My system for saving water is pretty basic but works well; water is transferred from the kitchen basin to a bucket outside the back door, and from there to water butts in the garden. It takes a little effort, but isn't a big deal; I prefer low-tech solutions anyway.

But often it's not really necessary to wash some dishes at all. Or at least not that often. Could that plate be reused if the crumbs are brushed off? Ditto the bread knife?

Some years ago I shared an office at the university I worked at, with the writer Marina Lewcyka ; this was before Marina became a best-selling author with her 'Tractors' novel. Now I’d never done this myself, but perhaps it was her experience of being a refugee as a child, or just that Ukrainians are less wasteful, but Marina would reuse the same tea bag, leaving it in her mug several times, until it expired through sheer exhaustion. We no longer share an office since her writing career took off, but I adopted Marina's approach to tea bags, although using the same one three times is my record so far.

"If we had to carry water, we'd be a lot more careful about how we used it."


When I was born in a small terrace of four cottages, my family had only just had mains water supplied. Before that water was pumped from the well at an end cottage and carried round to the house. So, in a sense, it's more difficult now, because all we have to do is turn the tap and out it comes. If we had to carry water, even across a relatively short distance, we'd be a lot more careful about how we used it.

While I’m only concerned with dish washing here, you can - as you already know - reduce the water flowing from your property into the municipal mains quite seriously by adopting a few other methods. It’s relatively easy to divert rain water from down pipes directly into water butts. And soft permeable surfaces in our gardens and around our homes help water soak into the ground rather than running off into the drains.

This run-off is a significant amount and not helped by the loss of gardens and lawns to form hard standing for cars. It's quite possible to do this with permeable materials but despite local authority guidelines, too many are still being made from concrete and other impermeable materials. A survey by the Wildlife Trust in 2011 found that gardens in London were being converted to hard surfaces at the rate of 3,000 ha (7,410 acres) a year. That's the equivalent of two and a half Hyde Parks.

Of course, in permaculture we know about keeping energy - and water is one form - on our sites for as long as possible. But what I didn’t know, until I went to a talk on water gardening last summer given by Dr Nigel Dunnett of Sheffield University’s Landscape Department, was that if you do this seriously, it’s possible to get a reduction in your water charge bill.

I've somewhat blurred reducing and reusing with my talk of tea bags; reusing something - a tea bag, a plate - should lead to a reduction in the amount of water we use to wash with anyway.

But when we have washed dishes, what then?

Grey Water


Water left from washing dishes is termed 'grey' water, and can be used to water garden plants. This does hold traces of food, grease, etc., and the detergent used could contain a wide range of ingredients, some of which can make plants more likely to take up heavy metals, for example. Ecological products, like Ecover, are better, but why not gather some soapwort and make your own: this is not something I have done yet, but plan to try later this year.

Grey water is probably best filtered (sieved?) to remove any larger traces of food and then left for a day, or so to allow micro-organisms to break down some of the ingredients and to let any scraps that passed the filtering process to settle to the bottom. A rough rule of thumb is to only leave this water for one day in summer, perhaps two in spring and autumn. The water can poured onto the soil around garden plants: organisms in the soil continue to breakdown any ingredients further still.

Given the right site, you can always create a reed bed that filters the grey water before it reaches the garden. These are typically made of coarse gravel, with smaller 'pea' gravel above, and then a layer of sand on top of that. It's then planted with reeds, and will take at least a year before it works properly; the actual work is done by bacteria living on the roots of the reeds. Water comes in at the top, via a sieve or filter, to remove unwanted material, and then out and into the garden.

Reed beds can be fairly small - old baths have been used to hold them - and a surface area of one square metre per person is a rough guide. Connecting the outflow from your kitchen sink to one of these recycles the water and takes the effort out of the whole process: unfortunately, our neighbours have access between our house and garden, and so a pipe into the garden isn't feasible.

"Missing out one of these daily washings would save 6.8 litres"


In a spirit of scientific enquiry, I decided to measure my dish washing water use. Our boiler is an older type and it takes a few minutes before the water coming through the tap is hot enough for washing dishes. This amounted to six pints, or 3.4 litres. Using my dish washing average of three times a day gives a daily run-off of 10.2 litres; over the course of a year that’s a significant 3,723 litres.

Being reasonably careful with water use, I only use about six pints (3.4 litres) of hot water for actual washing; this is based on dishes for two from supper and breakfast (two bowls, four mugs, two cups and saucers, two plates, plus odds and ends). Missing out one of these daily washings would save 6.8 litres (the cold run-off and hot water) per day, adding up to a not insignificant 2,482 litres per year.

So whether you want to think about it as reusing or recycling, there are practical, beneficial outcomes to dish washing in addition to sparkling plates and cutlery. The water saved from even a simple, everyday activity such as this, can make a difference. And you don't have to spill blood to do it.


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