INTRODUCTION

Here we are going to talk about one of the most difficult areas to unhook from. Recycling your own water is an expensive business and several solutions require more land than most people have, such as a reed bed. Not only does such a system need to be a certain size but also, for obvious reasons, needs to be a certain distance from your property. Especially in summer. In fact, by the time you get done with this section, you might actually start being glad that you’re paying your water bill and that you don’t have to organise the whole shebang yourself! When you look at the figures for setting up your own water recycling system for a house you’ll soon see how reasonable £200–300 a year is.

But there are a lot of aspects of recycling water, as we shall see. It might not be possible to recycle everything, but it is still possible to do something. For example, did you know that one the largest parts of the average household’s water usage is from flushing the loo? Does it really need to be done with clean, drinking water? You’ll soon see that big savings can be made by just attacking one or two parts of the problem.

You might be surprised to see a section about water: What’s that got to do with being carbon neutral? Do the water companies really use a lot of fossil fuel? Surprisingly, the answer is yes.

‘Over 10 billion litres of sewage are produced every day in England and Wales. It takes approximately 6.34 gigawatt hours of energy to treat this volume of sewage, almost 1 per cent of the average daily electricity consumption of England and Wales.’ (www.parliament.uk)

This amount of energy is not without its carbon cost, and beyond this we need to address this section in terms of sustainability.

A load of jargon

When people who know what they’re on about start talking about water recycling, they use terms like ‘black water’ and ‘grey water’. Below is a list of terms you may not be familiar with.

Potable water: drinking water.

Black water: raw sewage. This is the stuff that gets flushed out of your loo.

Grey water: all other waste water: what goes down the plughole. It’s bath water, washing machine outflow and other waste.

Primary treatment: the stage of sewage treatment: this separates out the solids from the liquids.

Secondary treatment: after separation: this treats the liquids that drain out of the primary treatment.

INPUTS

WATER USAGE

What is our water used for? The amount of water used by each household, and the uses it is put to, will of course vary. But the average household uses over a week (see www.freerain.co.uk):

Item	Litres	Per cent
Toilet flush	165	33
Personal washing	120	24
Drinking & cooking	75	15
Washing machine	60	12
Washing up	45	9
Garden & car	35	7

It seems incredible that a third of our water usage is for flushing the loo. Even worse, it’s drinking water. This seems like such an obvious target for reducing and recycling, it’s a wonder it’s not done more often. Many people, myself included, would probably have thought bathing would have been at the top of the list.

But it’s worth bearing in mind that these are just estimates and different sources will give different figures. If you are seriously considering recycling your own water, you’ll want to make more accurate measurements.

Should I get a water meter fitted?

Ideally yes, everyone should get one fitted. However, you ought to be aware how much this is going to cost you, as you could be in for a shock! Just as I urge folks to calculate their electricity usage, and reduce it before getting a wind turbine, so I would urge anyone thinking of getting a water meter fitted to calculate their water usage and reduce any waste here first. If you do phone up your water company, they will go through the approximate cost first and ensure that you understand what it entails. Remember that getting a water meter fitted won’t do anything for the environment, only the way in which you’re charged. What actually makes the difference here is reducing the amount of water your household uses.

It would have been nice to include a system here to calculate how much you’d be charged with a water meter, but it’s not that simple! Different water companies charge in different ways. The charge can also be reduced if you only require an input (i.e. you’re recycling all your waste water and sewage), or if you don’t require any surface water drainage (disposal of rainwater). Either way it is difficult to pin down exactly what your usage will cost.

However, you can calculate the amount you use. An excellent water calculator can be found on the BBC website (www.bbc.co.uk) by searching for ‘water calculator’. Rather than try to calculate a cost, this calculates the amount you use.

Alternatively, you can use the do it manually using the following table. This table started life as the ‘Water Calculator Workings’ from the BBC site. However, some items have been removed and others added.

Detailed water usage

Item	Usage (litres)	Source
Shower	7 per minute	Waterwise
Power shower	12 per minute	Waterwise
Bath	80 – 90	Various
Brush teeth – water on	10	MyInternet
Brush teeth – water off	1	MyInternet
Wash hands or face	5	MyInternet
Toilet flush	4.5 – 13	Various
Running tap	6 per minute	Thames Water
Washing up	10 (2×5 litre bowl)	Various
Dishwasher (modern)	15	Waterwise
Washing machine (modern)	50	Environment Agency
Hosepipe	500 per hour	Waterwise

For example, if in one day I have a bath, brush my teeth (with the water off) twice, wash my face twice, flush the toilet three times, and do the washing up once, then my water usage might be a total of 120 litres per day:

Bath	80
Brush teeth – water off	2
Wash my face twice	10 (2 × 5 litres)
Flush toilet three times	18 (3 × 6 litres)
Washing up	10
Total:	120

This adds up to 43,800 litres over a year.

TYPES OF SYSTEM

Water butt

Really, this system couldn’t be simpler and as far as inputs go it has to be the first that anyone should try. A section of drainpipe is replaced with a special collector which sends rainwater down a pipe into a large plastic barrel. The collected water can then be used for watering the garden or washing the car. There’s really nothing more to it than that. There are dozens of different types available from DIY shops, the internet or your water company. They start at around £20–30, with a stand for around £10. Diverter kits are also available which allow you to divert rainwater from a drainpipe straight into your water butt. These cost between £10–20.

Rainwater harvesting

This is perhaps one of the most exciting and romantic ideas – getting all your water for free, off the roof. But it isn’t as simple as that. Water collected from the roof is actually only suitable for a few purposes:

• flushing the loo
• washing clothes
• watering the garden
• washing the car.

So before looking at harvesting rainwater, we need to look at what we are going to use it for. As we’ve seen, flushing the loo is potentially the biggest area for savings.

How does it work?

In theory they’re quite simple. Rainwater is collected via your downpipes in the same way as a water butt would, but instead of going into your water butt the rainwater goes into a very large container, usually buried underground to save space. Then, in the same way that mains water is pumped up to the header tank at the top of the house, rainwater is pumped up to a separate tank. So when you flush the loo, for example, instead of drawing water from the mains header tank, it is drawn from the rainwater header tank. You can also get an outside tap fitted to the rainwater tank for the garden or car.

How much does it cost?

The issue with rainwater harvesting systems is the same for a lot of the systems mentioned – money. Such a system can easily set you back £2–3,000. And when you consider that an entire year’s supply of water is only £2–300, this isn’t going to pay itself back any time soon unless water suddenly becomes very expensive. Does this mean no one should bother? No, it’s just that there are dozens of other items to spend this amount of money on that would help reduce carbon emissions and enable people to lead more sustainable lives.

As the Centre for Alternative Technology puts it (www.cat.org.uk):

‘A rainwater harvesting system to provide toilet flushing for a 3 or 4 bedroom house is likely to cost at least £2,000. It may be possible to install a simpler gravity-fed system, for a ground-floor toilet and garden watering, for less then £1,000. Because these systems are fairly expensive, the payback time can be very long. In fact a system might never recover its costs if parts need replacing before savings are realised – especially if your water is not metered.’

Grey water recycling

This one could really qualify under inputs and outputs, as it covers the output of grey water, and also the input of water for flushing the loo. But the principle is so similar to the rainwater harvesting system that I thought it would be suited to this section.

Simply put, a grey water recycling system runs in a similar fashion to the rain harvesting system above, in that waste water is collected in a large tank, then pumped up to a header tank, before being used to flush the toilet or water the garden. The biggest difference between this system and the rainwater harvesting system is that the input to the system is grey water, rather than rainwater. The only restriction that this causes is that some plants may not fare well when watered with grey water, and obviously you can’t use grey water to wash your clothes. However, it can still be used to flush the loo, the biggest cost of water.

Drawbacks

Essentially this has similar drawbacks to a rainwater harvesting system, such as the expense in setting such a system up. Also, the effect on the environment may not be positive in the long run:

‘Commercially available grey water recycling systems use disinfectants that are often very energy intensive to produce – and which may also cause problems if you have a private sewage treatment system. All independently published case studies of installed systems have shown running costs higher than that of mains water supply. Given the infrastructure requirements and the disinfectant doses needed, it is very difficult to see these systems as environmentally friendly, especially for individual households.’ (www.cat.org.uk)

The reason why these systems are not entirely suitable in Britain is simply that we are lucky enough to have a plentiful supply of rainwater. Despite the environmental effects, countries with much drier climates would probably benefit from these systems a great deal. In Australia, for example, such systems may become essential as clean drinking water becomes more scarce.

Boreholes

These are the modern equivalent of a well where you source your own water supply. However, it affects the amount of water in the garden soil, or immediate area, and the setup is quite expensive. Prices can start from about £6,000.

Even at £300 per year for your water bill, this is still a 20-year payback, and even then you must somehow dispose of your grey and black water. This is not a straightforward proposition!

OUTPUTS

DISPOSING OF SEWAGE

There are several systems for disposing of sewage (also known as black water), but none of them are without their issues or expense. Given the previously mentioned low cost of a water bill, these are probably only suitable where connection to the mains is impractical, such as in isolated rural areas. But for the sake of completeness, the systems are outlined below.

Composting toilet

Probably one of the simplest systems available. You can actually make your own quite easily and The Humanure Handbook is happy to tell you how! Essentially, you need a large, plastic bucket which can be easily removed and replaced with another. Fitting on top of this is a standard loo seat with a hinged top, so that the buckets can easily be taken out. Every time you go to the loo, you throw in a handful of sawdust which creates a ready-made bucket of compost material.

Apart from the initial reaction of horror, this is actually quite a simple system, provided you don’t mind lugging a bucket of waste outside with you every few weeks!

The catch with a composting toilet is where the composting takes place. The process can take up to two years before it is ready to be safely used on your garden, and even then you are likely to produce far more than is needed for the average garden!

Septic tank

This is the first stage in the traditional treatment of sewage – settlement. A septic tank allows solids and liquids to separate. The solids need removing and taking away periodically, whereas the liquids flow out to a secondary treatment. Typically this is a leachfield: perforated pipes lead out of the septic tank, and the liquids seep out into gravel beds. There micro-organisms remove and digest solids, before it eventually ends up in our groundwater.

Such a system would allow you to dispense with the mains water for sewage disposal, but the solids from your septic tank would still need to be disposed of in some way every so often, so how far ahead does this get you? Given the expense of such a system, I’d probably be more inclined to try out the composting toilet!

Reed beds

At some point in the past you may have heard about reed beds being used for sewage treatment. This is a secondary stage treatment system only, and is really only suitable on a small scale. The Hockerton Housing Project of four households, for example, uses a reed bed treatment system. The reed bed’s roots and micro-organisms effectively do the work of the gravel bed in the leachfield system (above). It makes the effluent safe to be allowed into the groundwater.

Disadvantages

It is only a secondary treatment system, so the solids still need to be dealt with in the same manner as they would with a septic tank.

A reed bed requires a significant area of land, similar to many of the systems mentioned here for the treatment of black water. It needs an area much bigger than the back garden that many people have available – probably about the same area as a swimming pool. It’s also not likely to be cheap.

Advantages

Having said all this, the advantages should be kept in mind. Principally, a reed bed system requires no chemicals or electricity, other than perhaps a small pump to get the water from the septic tank, if necessary. It also produces very clean water, so clean in fact that even chemical pollutants and heavy metals can be removed. With a suitable filtration system, the water can even be returned to potable water.

SAVING WATER

To be fair, when you look at the expense involved in the sophisticated systems detailed in this chapter, most of us are better off simply following some basic guidelines for saving water.

Flushing the toilet

If you take nothing else away with you from this chapter, take this: a third of all our water use goes down the toilet. So unless you’re going to set up a system for disposing of your own sewage, as outlined above, then the biggest single saving you can make is to reduce the amount of water you flush down the toilet.

Calculating your cistern size

The first thing to do here is to find out how much water your cistern actually holds.

• 1.Take off the cistern lid – carefully.
• 2.Hold up the float, so that the cistern doesn’t fill up (you will need someone to help you).
• 3.Carefully measure out the water with a measuring jug. Make sure you don’t damage the float or ball valve.

The results from this little exercise can be quite astounding. Measurements will vary anything from six to 12 litres. Given that it only takes about six litres to flush a loo, a 12 litre toilet is wasting an awful lot. Remember this isn’t even recycled water, it’s pure drinking water!

Reducing your cistern’s capacity

The first thing to do then, is to reduce your cistern’s capacity to six litres (your friend can let go of the float now). There are a number of devices around which can do the job – the most famous being the ‘hippo’, which is available from www.hippo-the-watersaver.co.uk

But if you’re impatient like me, you can always make your own.

A used, half litre bottle of water (or whatever) can be refilled with tap water, and placed in the bottom of the cistern. This is accurate and safe. You might want to look at using several bottles to measure out the amount you require. ‘Cisterns installed before 1993 use nine litres per flush but can still be perfectly effective with six or seven’ (www.cambridge-water.co.uk). So if your cistern is nine litre capacity, then you’ll need six half litre bottles to reduce the capacity. It’s that simple.

Be careful when you do this though, as the items in your cistern can easily be damaged or dislodged whilst adding your containers. It can also be quite a narrow space and you may find that the water bottles won’t quite fit. If this is the case, then go for the hippo, or one of those provided by the water companies.

Other options

It would be nice, of course, to replace your toilet with a low flush version, but this would be costly overkill to simply save water! If, however, you do need to swap your toilet at any stage, it makes good sense to get a low flush model and then all this jiggery-pokery won’t be necessary.

If you do have the money to invest, a rain harvesting system can provide the six litres of toilet flush, to completely replace this usage of clean, drinking water.

Baths and showers

Baths use 90 litres of water, whereas showers use only 30 litres, so definitely take a shower, not a bath. Power showers are to be avoided, as they can use up nearly as much as a bath.

If your shower is electric, and your hot water is from a carbon neutral source (such as a solar panel), then you may want to get a mixer shower fitted. This way you can have the best of both worlds – minimum water usage, heated by a carbon neutral source.

Another way to save even more water is to fit your shower with a low flow showerhead. You can ask for more information at your local plumbing or DIY store.

Washing machines

Most washing machines consume around 50 litres or more per load, so if you’re thinking of getting a new model, or replacing your current model with a more efficient one, it is worth looking at how much water each one uses. A good list of comparisons can be found at www.waterwise.org.uk

The features of a decent A-rated washing machine are quite impressive. Many will allow you to select a maximum temperature or spin speed. They also often have very short programs, so for loads which just need to be freshened up, you can use the minimum amount of water (and energy). Do bear this in mind if your washing machine is up for renewal.

Brushing your teeth

Don’t leave the tap running! You can just put the plug in and use a shallow amount of water. You can always rinse your mouth out either with a couple of swigs from the tap or from a glass of water.

As we’ve seen in the figures above, it’s the difference between 10 litres and one litre of water.

CONCLUSION

Handling your own water supply and disposal is very expensive and takes a certain area of land, especially the handling of sewage. To do this job properly would take a purpose-built house such as that built at the Hockerton Housing Project or CAT in Wales. The prospects for fitting sustainable systems to existing housing are not good.

Having said this, there is likely to be a certain amount of waste in any system, so you can still have a look at how you use your water, and how it can be improved, most notably by looking at your toilet flush.

After looking at conservation opportunities around the house, the next change you could make is to install a water butt for watering the garden, and so on. These are widely available and relatively easy to fit. They also have the advantage of being exempt from any hosepipe bans!

If you do have money to invest in your water system, it is possible to implement a rainwater harvesting system which can primarily be used for flushing your loo, although this is likely to cost over £2,000 and take decades to pay off.

Beyond this you are looking at large, radical installations, such as a composting toilet or a reed bed. Such a change to your home (and possibly lifestyle) is going to cost a similar chunk to the rainwater harvesting system, and will require an area of land to be turned over to this purpose.

So for many of us, it’s probably best to be economical with the water we get, and be thankful for the system we already have in place!