First you need to check if you can legally recycle grey water on your garden.Your choice of grey water is important for health reasons.

About greywater reuse

Greywater is water from your bathroom sinks, showers, tubs, and washing machines. It is not water that has come into contact with feces, either from the toilet or from washing diapers. Greywater may contain traces of dirt, food, grease, hair, and certain household cleaning products. While greywater may look “dirty,” it is a safe and even beneficial source of irrigation water in a yard.

If released into rivers, lakes, or estuaries, the nutrients in greywater become pollutants, but to plants, they are valuable fertilizer. Aside from the obvious benefits of saving water (and money on your water bill), reusing your greywater keeps it out of the sewer or septic system, thereby reducing the chance that it will pollute local water bodies. Reusing greywater for irrigation reconnects urban residents and our backyard gardens to the natural water cycle.

The easiest way to use greywater is to pipe it directly outside and use it to water ornamental plants or fruit trees. Greywater can be used directly on vegetables as long as it doesn’t touch edible parts of the plants. In any greywater system, it is essential to put nothing toxic down the drain–no bleach, no dye, no bath salts, no cleanser, no shampoo with unpronounceable ingredients, and no products containing boron, which is toxic to plants. It is crucial to use all-natural, biodegradable soaps whose ingredients do not harm plants. Most powdered detergent, and some liquid detergent, is sodium based, but sodium can keep seeds from sprouting and destroy the structure of clay soils.

Chose salt-free liquid soaps. While you’re at it, watch out for your own health: “natural” body products often contain substances toxic to humans, including parabens, stearalkonium chloride, phenoxyethanol, polyethelene glycol (PEG), and synthetic fragrances. (to learn more about what’s in your products, go to the Cosmetic Database and see how they rate for toxicity). Read our recommendations for soaps and products here.

Basic Greywater Guidelines

Greywater is different from fresh water and requires different guidelines for it to be reused.

1. Don’t store greywater (more than 24 hours). If you store greywater the nutrients in it will start to break down, creating bad odors.

2. Minimize contact with greywater. Greywater could potentially contain a pathogen if an infected person’s feces got into the water, so your system should be designed for the water to soak into the ground and not be available for people or animals to drink.

3. Infiltrate greywater into the ground, don’t allow it to pool up or run off (knowing how well water drains into your soil (or the soil percolation rate of your soil) will help with proper design. Pooling greywater can provide  mosquito breeding grounds, as well as a place for human contact with greywater.

4. Keep your system as simple as possible, avoid pumps, avoid filters that need upkeep. Simple systems last longer, require less maintenance, require less energy and cost less money.

5. Install a 3-way valve for easy switching between the greywater system and the sewer/septic.

6. Match the amount of greywater your plants will receive with their irrigation needs.

Laundry Drum:

Drum should be strapped to wall for safety.

If you don’t want to invest much money the system (maybe you are a renter), or have a lot of hardscape (concrete/patio) between your house and the area to irrigate, we recommend a laundry drum system.

Wash water is pumped into a “drum,” a large barrel or temporary storage called a surge tank. At the bottom of the drum the water drains out into a hose that is moved around the yard to irrigate. This is the cheapest and easiest system to install, but requires constant moving of the hose for it to be effective at irrigating.

Laundry to Landscape (aka drumless laundry):

If you’re looking for system that gives you flexibility in what plants you’re able irrigate and takes very little maintenance, we recommend the laundry to landscape system.

In this system the hose leaving the washing machine is attached to a valve that allows for easy switching between the greywater system and the sewer. The greywater goes to 1″ irrigation line with outlets sending water to specific plants. This system is low cost, easy to install, and gives huge flexibility for irrigation. In most situations this is the number one place to start when choosing a greywater system!

From the Sinks. 

Kitchen sinks are the source of a fair amount of water, usually very high in organic matter (food, grease, etc.). Kitchen sinks are not allowed under many greywater codes, but are allowed in some states, like Montana. This water will clog many kinds of systems. To avoid clogging, we recommend branched drains to large mulch basins. Much less water passes through bathroom sinks. If combined with the shower water it will fall under the shower system, if used alone, it can be drained to a single large plant, or have the flow split to irrigate two or three plants.

Do’s and don’ts of greywater use

Do:

Wash your hands after watering with greywater

Use garden-friendly cleaning products that are biodegradable and are free from or low in sodium and phosphorous

Pipe greywater underground or under mulch to water your garden

Irrigate your ornamentals and orchards, making sure greywater is not in direct contact with fruit

Regularly check your greywater system is working properly

Divert greywater to the sewer during wet periods

Stop using greywater if someone in the household is sick

Check your state and local regulations

Use a licensed plumber to install your system

Avoid clogged soil by using a coarse filter to reduce the amount of solids in your greywater

Make sure you contain greywater within your property

Don’t

Store untreated greywater for more than 24 hours

Use greywater to water vegetables and herbs that are to be eaten raw or partly cooked

Use greywater sourced from washing nappies or soiled clothes

Use greywater that has disinfectants and bleaches in it

Use greywater from kitchens, unless it has been treated

Use greywater that is still hot as it will kill beneficial organisms in the soil

Spray or hose greywater

Allow pets to drink greywater.

If you are in Queensland check out this web site. In other areas check with your local council.

http://www.hpw.qld.gov.au/construction/BuildingPlumbing/Plumbing/Greywater/Pages/default.asp

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