Wednesday, 9 May 2007

bucketsful of water

The wet change in the weather reminded me that in this earlier post I described my surprise at the amount of water needed for dip-dyeing fabric and was going to suss how much was being used.

A length of prima cotton measuring 104 x 170 cm and weighing around 200 grams used between 80 and 107 litres. This was made up by 20 litres initial washing and rinsing, 5 soaking the cloth prior to dyeing, another 5 for the initial dye bath plus 1.5 used to dilute the salt and soda ash, and finally between 50 and 75 for final rinsing, rinsing and re-rinsing. When I switched process to overdyeing with a second colour (to achieve the intended wet sand colour) an additional 60 - 86 litres will have been used (the same as the first dyeing less the initial wash/rinse), totalling 140 to 193 litres.

These figures are way too high! Think of it in terms of milk or beer or petrol. No one would sensibly consider wasting 140 litres or 246 pints of Tribute, for instance, in such a way.

I can see ways to re-cycle the 'waste' water such as the initial soak water doubling as first dye rinse water. All used water could be stored for re-use as bucketed toilet-flush water instead of just the occasional bucket or two I did chuck there (though storage isn't too practical due to small bathroom size). According to toilet flushing uses 8 litres a go and this activity accounts for a third of our average daily use of 16 bucketsful of water. And to think I used 14 buckets-worth just for one dyeing!

When travelling in Australia and New Zealand I occasionally came across army personnel returning from training or just travelling across country, all very friendly and sociable (what sort of Aussie or Kiwi isn't!). Generous too, they often gave me their unused ration packs - high energy biscuits especially. An Aussie told me that they were trained to survive in the bush on just 4 (or was it 6? or 2?) litres of water a day - drinking, cooking, washing the lot. A real jaw dropper for me who drank 3 or 4 litres daily! Of course some water doubled up its uses, so for instance water that tinned food was cooked in could afterwards be drunk, or used to re-hydrate other food, and then for shaving. Other than drinking, I tried rationing my water for a few days to 4 litres and it wasn't much fun.

Yet many people in the world get by on twenty litres a day. If they can, can we? OFWAT reckons British household daily use is 352 litres, working out at 147 litres per person. About the equivalent for dyeing my cotton.

Being on a metred supply I can calculate my average daily water use. My bills show I used 45.9 cubic metres, or 45,900 litres between 22 February 2006 and 17 April 2007 (420 days). That is, 109 litres per day. The six months to the 25 August last year it averaged at 93.4 litres/day. The previous year it was 112 litres. But I am not smug or complacent - all are still a lot of water whether you compare it to bottles of Tribute, developing world use, or army rations.

And so, as part of sustainable batik practice and daily lifestyle I aim over the next year to further reduce my daily water use to below 80 litres (for starters).

As well as looking for ways to re-cycle dye-related water I should think more about harvesting rain for dyeing purposes. Currently I store rainfall from my shed roof for watering the garden, but because of living mid-terrace, with a right of way along the back impeding placement of a downpipe and butt, I haven't harvested rain from the house roof. At the moment it runs off into the mains sewers, such a waste (of water and of downstream re-treatment). Being able to harvest roof rainwater is one priority for when - eventually - I move house.

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