Sunday, April 09, 2006

Less water than the Sudan?


The media has coined a phrase over the last couple of weeks, that per head of population, the South East of England has less water than the Sudan.

I accept that this may well be the case, with Prescott's misguided policy of cramming as many people into the one corner of the country where there are limited water supplies.

It doesn't help that most of the water supply network in the south east is over 100 years old and domestic supplies are often through very leaky lead pipes.

I contacted my water company last summer concerned with low pressure and poor flow, and they came and dug up the road to look for leaks. I share my supply with 3 other houses, and its all through only a half inch lead pipe. Needless to say they found two pinhole leaks in the first 6 feet of pipe, where it branched off the main. So as the pipe is 60 feet long before it enters my house, there could easily loads more leaks!

As I am just one of about 100 houses in my road, built in the late 1880s to 1920s , there must be thousands of feet of 100 year old lead piping, all in very poor condition. Think of the total volume of water seeping out into the ground per day - yet it's only the spectacular big leaks that the water companies seem to bother about, whilst 30% of their supplies is leaking through pinholes!

I propose we subject the water company managers to Chinese water torture, and make them accountable for every drop of water that THEY waste. With moderm area metering, they know exactly how much they put into the main, and how much we consume - so clearly the rest is leaking away. Not surprising that the front gardens of Surrey never seem to need watering - the water company does that for free!

Perhaps I will call them up and ask to be put on a compulsory meter. They can dig the road up again, put me on a separate metered supply, and at least update some of their worn out infrastructure - such a shame that it might interfere with the Shareholder's profits. But if they don't have much water to sell in the first place, they won't be making much profit this year!

To help remedy the situation I have decided to sort out my grey water and rain water storage systems in an effort to reduce my water consumption.

Whilst not on a meter, I believe that it is important to realise how much water we use in a typical day. A few tests and measurements came up with the following figures:

Bath 125 litres
Shower (not a power shower) 3 litres per minute - so perhaps 15 litres per shower
Dishwasher 49 litres
Washing machine 40 litres
Toilet flush (No. 2) 10 litres
Cooking 10 litres
Misc (handwashing, teeth cleaning etc) 10 litres

So in a typical day, you could easily get through 250 to 300 litres and that's before you start spraying the stuff onto your car and garden. For households with children, these figures will increase significantly.

So if we deduct 50 to 100 litres for toilet flushing, potentially we are pouring away at least 200 litres per day of perfectly good water that could be recycled for loo flushing, and garden watering. A 200 litre grey water storage tank, will hold a whole day's waste and provide ample water for flushing the loo. So with this system in place, it could mean water savings of up to 35%, and give me all the water I need for watering the new vegetable patch.

The problem with waste water is that it generally disappears down a plug hole, through a pipe and emerges outside the property in an awkward place to get at it. Once down the plughole - we generally forget about it completely, and care little for where it goes - just so long as long as it goes! (Nobody likes a blocked sink, drain or loo - except my father in law, who as a retired plumber, looks at them as an occupational challenge and sets off like a ferret down a rabbit hole!)

It should be remembered that the water companies in the UK not only supply us with about 3000 m3 of pure drinking water per year, but they also remove about the same volume of grey water and sewage, a task that not many of us would like to volunteer for!

There are also the problems of plumbing up a toilet so that it can use grey water - fine if you can place the greywater tank above it, an upstairs tank used for example, to flush a downstairs loo.

Fortunately all of the grey water from my kitchen and bathroom ends up in the same sluice (photo above), and so it would be relatively easy to put a storage and filtering tank there, where the existing rain water butt is located.

The waste pipes emerge through the wall at about 12" above ground level, so it's going to be more of a coffin sized trough rather than a conventional tank. I'm thinking that a single sheet of steel or aluminium (8 x 4 feet) could be folded up into a substantial trough, about 6 x 2 x 1 feet - holding 340 litres. Perhaps farm suppliers might have something of a similar shape - for a livestock watering trough, complete with ball valve? As the ball rises, it flicks a microswitch and starts an electric pump, to pump the water up to a storage tank in the loft or upstairs bathroom.

However, as this area is going to become the patio, the tank could be clad in decking and made to serve as a permanent bench seat. Great for sipping your morning breakfast coffee on a sun drenched patio.

It's a good idea to let the natural force of gravity do much of the hard work, and letting the water filter through a strainer and then settle in a storage tank for a full day will help clean up the grey swill.

It might also be good policy to use less agressive detergents, particularly in the washing machine and dishwasher, if the water is going to be used for plant watering. Any strained out hair and food waste can always be put onto the compost heap.

Pumping the filtered water to a higher tank, might cause a few problems. I have considered using a solar powered pump that can shift about 12 litres per hour. A small pump like that will run happily off a 15W solar panel.

That's enough water for about 1 toilet flush per hour. And speaking of solar, we have had 4 good days of sunshine, and my solar panel has already heated up to 60C and contributing to the hot water tank at 9am these last few mornings.

As well as recycling the grey water, I will also re-jig the guttering on my house and extension, so that what rain we receive this year will be collected in a large water butt. I have some 208 litre plastic barrels that will be pressed into service for this.

An update will be supplied, when the system begins to take a more physical shape. Off now to the farm suppliers to look at polypropylene drinking troughs.

Catch some sun and collect some rain.....

2 comments:

NiC said...

Inspirational again..... I've spent half the day re-looking at our plumbing arrangements to determine how we could best re-use grey water and collect more rain water.

My only slight concern (as an ex-food industry microbiologist) is in using any water from human washing on vegetables. The risk of cross-contamination (of some of the less friendly gut bacteria) might be minimal but does exist... particularly a problem with sald crops where there's not going to be any cooking.

I'm not meaning to sound negative as I've found all this inspirational but I would tend to try and keep grey water for loo flushing and rain water for the crops.... which proably means a much larger storage for rain... rats!

Anonymous said...

Speaking from a country with GREAT water problems (the worst draught ever, aproaching desertic climate, and the greediest golf industry), we have to be much more careful than you people.
I think that things that are not paid are not appreciated, so we should demand from water suppliers to charge for the actual water use in each household, and include piping maintenance in their balances.
Apart from that (which is the greatest water source, because water mains are over dimensionated), the best source is to save water at home. I can give you some tips we use:
- Use a dishwasher, it uses much less energy and water.
- Use a "green" washing machine, using less water
- Change your toilets for more modern appliances which flush with two different volumes (small and big, no need to elaboarte).
- Use diffusors in taps, so that you get a more ample water flow using the same ammount of water.
- At the shower, collect cold water in a bin until the hot water comes through from the heater. Use it for floor cleaning, garden watering, etc.
- Shower rules: the last one to take the shower cleans it, no need to clean it while members of the family use it in turns.
- Collect the water you use to wash your vegetables in a bowl. Also recicle the water you use to boil vegetables (NOT cabbage, please).
- If you want cold drinking water, keep a bottle in the refrigerator, don´t open your tap until it arrives from somewhere.