Greywater Systems

There are lots of people out there both on the Internet and in books, suggesting that you use your grey water from the washing machine to water the gardens. But they are very short on the practical side of things about exactly how do you do it.

So here are a number of ideas and suggestions for you to consider. They are based on the system that I set up at my own place.

Here I will not deal with the issue as to whether or not the authorities in your area will permit you to use the grey water from the washing machine. That is a local area matter, as some will and some wont. That is up to you to consider and deal with, yourself.

Another thing to consider is looking at what type of washing powder you use. You may have to consider changing your brand of powder to a low phosphate type of washing powder.

Also consider the future maintenance, repairs and possible changes of the different aspects of your system. Set it up so that you can access the different parts of your system easily, now and in the future. Especially consider future plant growth, what may be easily accessible now, may not be in a few years as your plants grow up and round the system, or even as you add future mulch onto the gardens.

Washing Machine Pipe

You will have to either position the drums in a place where either where the current outlet pipe from the washing machine can reach them, or extend or replace the machines outlet pipe to reach the drums. My drums top sits a bit higher than the washing machine but the pump in the machine pumps it nicely uphill a bit, but not a great deal.

Sometimes it may be a suggestion to tie an old stocking over the end of the pipe as an extra method of filtering the junk out of the grey water. This would have to be checked and cleaned or replaced fairly regularly.

Drums

Choose dark coloured drums as opposed to clear or light coloured ones, and take precautions about light getting inside the drums.

This is because with the water and light you will get a build up of algae in the water which is always left in the base of the drum as well as on the wet sides of the drum. This stuff will cause you all sorts of problems in clogging up your system in the future, as well as giving you possible contamination problems from chemicals coming out of the algae.

It would help in the long run, if you can shade and cover the inlet holes in the top to prevent light reaching the inside of the drum for the same reasoning. It also prevents things like insects and frogs, getting into the drum and any possible breeding of things like mosquitoes.

When you first get your drums, make sure you rinse them out well, before you connect them up. Only choose drums that have been previously used for an acceptable purpose like detergents etc. Do not choose drums, which have been used for things like oils and poisons. As these chemicals will continue to junk up your system for a long time, and may cause long-term damage to your plants.

Consider positioning the drum where any overflow will not flood or damage property, but will flow onto high water using gardens/lawn.

So if you do not already have such an area within easy reach of Washing Machine, you might have to consider planning such a garden/lawn.

Secure the drums to a wall or post because the empty drums can easily be moved or damaged during periods of high winds or during storms.

Ensure that you position the drums so that the drum outlet is above the highest part of your garden beds. Garden beds above this, will receive little or no water. As water will not of course, run up hill.

Position the drums in full or part shade or grow plants to provide shade for them, to prevent the water in the base from heating up and possibly damaging plants when first released.

Water Flow

Remember that it will take a while to empty a drum of water, being on low pressure. So the outflow from the Washing Machine may well be faster than that of the drum and watering system can handle quickly, so consider well the possibility of either starting out with two drums or give yourself the space for a later expansion of the holding tank set-up.

It is probably better for a medium to large family to consider having two drums to begin with, to enable you to handle the outgoing grey water collection without it running over the top of drum and going to waste.

Joining up two or more Drums

Between the drum and the inline filter, put a Tee joiner in and connect this pipe to the outlet tap at the base of a second drum.

Connection Points

Tighten up the joints properly. Test them occasionally, some may work loose over time, or as a result of an accident.

Some types of connections or particular brands of fitting may require you to provide a sealing tape to make sure that they do not leak.

Maintain your connections in a proper state of repair.

Drum Tap Connection

After the connection to another drum but before irrigation lines, put a tap into the line. This will allow you to either fill the drum with water before letting the water run into the system. Or to isolate the drum when you are running tap water into the irrigation system, under pressure.

Another benefit of this tap is that it allows you to fill the drum through the system with tap water, turn off the tap. Then you can use the drum as a mixing and dispensing container system for the purpose of feeding your gardens with some of the water-soluble fertilizers or soil conditioners. This is a great idea for the lazy gardener.

Tap/Hose Connection

This allows you to give the system a regular flushing, under high pressure to rid it of some of the stuff building up on the walls of the pipes and around the sprinkler nozzles.

Don't forget also to give the system an initial flushing to remove any stuff in the pipes before you first use the system.

This way the same system can be used to water the gardens with high-pressure water as low-pressure grey water.

Inline Filters

Install them correctly, so that the flow is correct for catching stuff out of the water.

Maintain them properly, and clean/replace them as needed.

Clean them every few weeks to help stop the extra matter from getting into the system.

Stuff in the Water

Whether it is soil or bits of tissues or whatever else that ends up in folds or pockets of clothes you have to be prepared for some extraneous matter in grey water, that's why your clothes need washing in the first place after all. So it is important to have an inline filter in the system. This also applies for the mains end of the system, as it is amazing how much stuff accumulates in the filter applied to taps running mains water.

Backflow preventer

Especially important when using the same watering system for both tap and grey water irrigation, you would have to include a backflow preventer to stop the tap side sucking back any junk into the mains water or hose.

Bacteria, viruses as well as things, which are on clothes like solvents, poisons etc. cannot be allowed to get into your tap water, remember you actually drink that stuff.

Flushing the System

Despite your best efforts, stuff will still get out into your watering system, so connecting the mains pressure system up, and use it to flush out some of the stuff. It may save on some of the repairs or other cleaning of things like sprinkler nozzles.

Rather than put end stops at the last part of the irrigation system lines, or kinking over the pipes. Try putting in a tap instead, this will allow you to flush the pipes themselves, every so often.

Poly' Pipe

The further along your system you can continue to use the 18mm (3/4 in') black plastic pipe the better pressure that you will maintain along the system. Try not to drop the size of pipe back to 12mm (1/2in') until you get to the gardens, if at all.

Bury or shade your pipe system under plants or mulch/soil, as much as possible. Because pipes which are heated by the sun will deliver hot damaging water to your plants, resulting in permanent damage or even death.

Bury the pipe as necessary, in areas where pedestrian, car or mower traffic may interfere with or damage it.

Irrigation Lines

Long single runs that end suddenly will cause a drop in pressure to nothing over distance some where along the line. It is better to set up loops or shorter multiple runs, for this type of low-pressure system.

Another possibility is that you may try joining the ends of two long runs together with a tap between them. Open this when using grey water, and close it when using the higher- pressure tap water.

Most Internet or box sets of instructions, for setting up your irrigation system also work for this type of system. Except for the fact that low pressure systems work better with a bigger gauge of pipe rather than the higher pressure but lower gauge tap systems.

Sprinkler Nozzles

Choose your type of sprinkler nozzle carefully; the types with lots of little holes will clog up very quickly. These are also very hard to clean out. Choose ones with a single dispensing hole, but which can be cleaned easily, by sticking a stick or small piece of wire through them.

Even so, a regular checking of nozzles and the immediate repair, replacement or cleaning of problem ones will ensure that the system operates properly, and do the job that it was installed for.

To be honest, until I sat down and wrote this article, I really had not realised just how many different factors I had had to consider and evaluate, when I set up my own system.

In some aspects, I compromised on certain things like the size of piping. Most of my system was done in 12mm (1/2 in), because that was the size pipe I already had on hand. And only the first parts are in 18mm (3/4in). The first thing is to look at what you already have and see what can be adapted without setting up a whole new system.

After all the main reason that you do this type of job around your home, is to make life easier for yourself, not more difficult. You can always make additions and improvements later on, as you see how the system works in your particular situation.

About The Author: © 2002 Ron Williams
Ron Williams is a Freelance writer as well as being a Horticulturist and a Rehabilitation Therapy Aid at a Psychiatric Hospital in Brisbane, Queensland, Australia. He writes ezines for wz.com. He runs his own Website called Bare Bones Gardening. He also owns a discussion group about Australian Gardening, called Austgardens at http://www.groups.yahoo.com

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