Without doubt water, or the lack of it, has long been one of Australia’s biggest concerns. We love our water based recreational activities and we love drinking the stuff.  Those above the age of 25 probably have fond memories of sunny summer days spent guilt free under the sprinkler; darting around in bathers having water fights with mates using the latest ultimate water gun or using dozens of water filled balloons.

But now times have changed. With water restrictions in most part of Australia, water is now a commodity that is getting more precious than gold. Every drop counts as the dams seem to decrease in level at a drastically fast rate.  In reaction, rising costs and increased public awareness of the plight of this vital resource has encouraged more people to look at ways to not only use water wisely, but looking at genuine ways of re-using water that has already been used.

So how can you ‘re-use’ water? What are the limitations, classifications and processes involved in safely catching, storing and using grey water? How can you avoid creating black water? The need to re-think and consider more productive ways to save and re-use water has fast become an everyday priority. Believe it or not, grey is now certainly the new blue.

Quick Links

What Is Grey Water?
What Is Black Water?
Choosing Detergents And Cleaners
Grey Water Regulations
Grey Water Systems
Rebates
The Do's And Don't's Of Grey Water

Water and Today:

Currently, the average Australian household uses about 240,000 litres (about 5 domestic swimming pools) of fresh water each year. Of this 240,000 litres, about 13% is flushed down the toilet, another 25% is used in the bathroom for showering, brushing teeth, shaving, washing hands etc, while a whopping 32% is used in the garden.

Having said all that stats are showing that Australians are becoming increasingly aware of the uses of grey water. In 2007 the Australian Bureau of Statistics conducted a survey on people’s views and practices in regards to environmental issues. Results showed that more than half (55%) of all Australian households were using grey water.In addition, the majority of Australian households admitted to undertaking water saving activities., with 67% of people revealing that were saving water in the bathroom, 64% in the laundry, 50% in the kitchen, and 40% in the toilet.

What is Grey Water?

When you turn a tap on, fresh, drinkable water (hopefully) comes out of your tap. Depending on what contaminants that water comes in contact with between the tap and the plug, that water that goes down the plug is generally classed as grey water. The term ‘grey water’ originates in most part due to a cloudy appearance that water may get after its use, and  also from its status as being the water that is neither ‘Black water’ (heavily polluted water like sewage or chemical infused water) or ‘Fresh water’ (occasionally referred to ‘white water’).  Grey water’s most likely sources are those that don’t contaminate the water with ‘black water creating chemicals or waste during it use. They are generally non-toilet plumbing systems such as hand basins, washing machines, showers, baths, spa baths, laundry tubs, kitchen sinks and dishwashers.

Some people often refer to grey water as ‘recycled’ water, however technically this is not the case. The green community see recycled water as being water that has been treated and then put back in the pipes, ready for human consumption again (usually sourced from waste water or from a usually undrinkable water source; i.e. sewage or sea water). London is perhaps the most well known for recycling their sewage water. In fact there is a fantastic quip about the London water recycling program that claims that for every glass of water you drink in London, it has been drunk 6 times before. Research conducted by the London Metropolitan Water Board in the 1960s. 

What is Black Water?

The term ‘black water’ is used to describe water that has been contaminated with chemicals, faecal matter, urine, oil, food and some detergents. Black water is harmful to drink and is not suitable for distribution on gardens due to increased toxins that could be harmful to humans, pets and the environment. It is also referred to as ‘waste water’, ‘toilet waste’ and ‘sewage’.

Avoid Turning Fresh or Grey Water into Black Water:

By staying aware of what you are mixing with your fresh water, it can be quite easy to ensure your water usage results in grey water and not black water. There are some simple changes you could make that will dramatically reduce your contaminating your water in all water using rooms in your house.

• Install a lint filter in your washing machine.
• Avoid urinating in the shower or bath.
• Scraping food scraps into a bin before putting plates or dishes into the dishwasher.
• Lately laundry products have been putting an (NP) symbol on their products to indicate that the product has little or no phosphorus. Look for products with this symbol.
• Don’t unnecessarily overuse on detergents.
• Use liquid detergents rather than powders.
• In the kitchen, filter the water to help remove fats and oils.
• Try to separate dirty washing; for eg work clothes, that may contain harmful chemicals such as paint or oil. Once you have a full load of these clothes, divert the water used to clean the load down the usual pipes, not into your grey water system.
• Have a trial section on your garden to see if there are any effects of your grey water on your lawn.
• Avoid corrosive chemicals. Look for the Corrosive Chemical Logo.
• Also avoid water softeners and conditioners because they involve replacing the magnesium and calcium in hard water with sodium; this thus alters the mineral content and spoils the foundation of the soil.
• Check the pH levels of your soil on a regular basis. Good soil pH test kits are about $20 and can be purchased from any good nursery.

Choosing detergents and cleaners:

Simply, the chemicals used in some cleaners and detergents present possibly the quickest way to turn your grey water into black water. It is quite important to take into consideration what types of detergents, soaps and chemicals you are using in the household for washing, cooking, showering etc. When looking for detergents and cleaners, keep the following ingredients to a minimum or monitor their levels as they can contain harmful characteristics:
•    Sodium (Salts)
•    Phosphorous
•    Nitrogen
•    Boron
•    Chlorine
•    Soaps
•    pH

-Sodium (Salts):

Sodium and salts are included in washing powders as fillers. It is important to minimise the sodium content of grey water to prevent soil salinity. Generally, anything higher than the accepted level of 20g of sodium per wash is likely to become problematic however obviously the lower this figure is, the better your garden will tolerate the sodium level. It is worth noting that concentrated powders and liquids do have lower salt levels than the everyday washing powder.  It is also interesting to note also that powder detergents have about 10-20 times more sodium than liquid detergents. `

In a shameless plug, aToMik Green’s Enviroclean Front Load Liquid Laundry 1L contains about 2 grams of sodium, well and truly below the maximum level. It is possible to find product with even lower sodium levels however.
Sodium and salts are included in washing powders as filler. Concentrated powders and liquids do have lower slat levels than the everyday washing powder. It is important to minimise the sodium content of grey water to prevent soil salinity. Generally the accepted level of sodium per wash is 20g, however obviously the lower this figure is, the better your garden will tolerate the sodium level. Anything higher than 20g is likely to become problematic. It is interesting to note also that powder detergents have about 10-20 times more sodium than liquid detergents.

In a shameless plug, aToMik Green’s Enviroclean Front Load Liquid Laundry contains about 2 grams of sodium, well and truly below the maximum level. In addition there are other products on sale that do have lower levels.

-Phosphorus:

Phosphorus is used as a ‘builder’ in laundry detergents as well as a simply way to overcome the ‘hardness’ of some water qualities. It is believed that high level of phosphorus in grey water can be extremely toxic to plants, especially native Australian plants as it can cause iron deficiency.

Generally, the accepted maximum level of phosphorus is 7.8 grams per wash however there seems to be some conjecture as to why this is the chosen accepted level. Lanfax Labs argue that “The reason for this level is unclear as there is no obvious scientific evident to show this level is safe. Indeed, converting 7.8 g P/wash for a front loader using 25 L per wash, gives a concentration of 300 mg/L. Interesting that many of the sewage treatment works are required to remove phosphorus to less than 1 mg/L.” The site also displays two very interesting graphs detailing Phosphorus levels in common front load and top load washing powders. You may be interested to note where aToMik Green’s own EnviroClean products are placed.

Perhaps the safest way to ensure that you are not exceeding tolerable PH levels is to simply purchase products that contain as little to no phosphorus as possible. Recently product manufacturers have been marking their products with an ‘NP’ symbol to show that the product contains little or no phosphorous to make this selection process a little easier.

-Nitrogen

Generally, there is are low levels of nitrogen in washing detergents and in small quantities nitrogen can be quite useful to the plants for fertilizing and aiding in plant growth. An excess of nitrogen however can lead to acidification and nitrate leaching, which is damaging to the soil quality. It is interesting to note that liquid detergents have been found to have more nitrogen than powders.

-Boron, Borate or Boroteam:

Boron seems to be to plants what reality TV show Big Brother was to Australians. It’s tolerable, perhaps even beneficial to begin with, but prolonged periods of exposure to it can become quite detrimental to health.

Boron is used in washing detergents as a source of 'active oxygen', however it can also be found in toothpastes as an anti-bleaching ingredient. For the trivia buffs, Boron and its derivatives are also used in glassware to withstand immediate changes in temperature,

High levels of Boron are believed to cause leaf burn in some plants, as well posing some difficulties when removing it once added to soil. It is also believed that Boron reduces the soils ability to absorb water. Having said that, through all the research conducted for this Boron section in washing detergents, there does not seem to be a genuine, fear invoking reason why Boron should be so drastically avoided in the same way Sodium and Phosphorus need to be avoided. Many, many resources seem to simply add Boron to their avoid list, but simply do not mention why. Whilst we are not completely dismissing the possibility that Boron does pose a ‘grey water threat’ we encourage you to make to your own decision as to what levels of Boron you are comfortable using. Alternatively, it may be simply easier to err on the side of the majority and simply look for products that contain little to no Boron at all.

-Chlorine

Chlorine is used in cleaning products primarily to sanitise, disinfect, whiten and deodorise clothes as well as purifying the water. Like Boron, it seems to be an ingredient that has some advantages and disadvantages. It is generally agreed that Chlorine can be quite toxic to soil as it kills off vital soil based organisms, block normal metabolic processes and act as a substitute for similar, required nutrients. Leaf burn is also an easy to spot symptom of chlorine in the soil.

However,  it also seems chlorine is thoroughly recommended as a grey water disinfectant, especially if the grey water is being used to flush toilet as the chance of diseases being spread through splashing is considerable.

When considering cleaning products, try to find a product that has no chlorine included at all.

-Soaps:

It is worthwhile being mindful of the soaps that you use if you are intending to reuse the water from the shower or bathroom sink. Fats from soaps that end up in can make the soil water-repellent. If you do use ‘normal’ soaps, it may be worth considering a change to a ‘fat free soap. Alternatively, use a soil rewetting agent on areas that have received soap infused grey water.

-pH:

While Grey Water should be healthy for your plants, too much of it can raise the pH level in your soil. Simply, the pH level is a measure of either the acidity or alkalinity level of your soil. Somewhat humorously, there seems to be a fair bit of disagreement as to what the p and H actually represent, with the p being anything from Power, to Potenz, to potential, to pH actually meaning ‘power of hydrogen’. What is important is to remember that pure water is said to be neutral, although neutral is not represented by 0, instead those that could decided it is should be 7.0. Acidic soils have a value less than 7.0, while alkalinic soils generally has a pH level greater than 7.0. Trusty old Wikipedia has a interesting article on the pro’s and con’s of having either acidic of alkalinic soils, which may be handy to know if you are interested to see what plants prefer to grow in either situation.

Signs that your soil is possibly too alkalinic is an iron insufficiency in plants, resulting in new leaves on your plants turning yellow with green veins. A high alkaline reading also means minerals such as iron and zinc become less available to plants. Alternatively, high acidic readings generally means nutrients such as nitrates, phosphates, and potassium become less available to plants.

It is quite easy to test the pH level of your soil and your grey water. Testing units are generally pretty cheap, (<$20) and reasonably easy to use. Remember that an acceptable pH level in grey water is between 7-7.5.

Grey Water Regulations

The use of grey water comes with some pretty strict rules and regulations about it sourcing, use, storage. The rules need to be strict considering the potential risks of damage to health and the environment if collected, stored or used incorrectly, and the regulations do vary from state to state. GMagazine have provided an excellent resource of links and information detailing grey water regulations from state to state.

Purple Pipes

To avoid cross-connection and contamination, all pipes designed to carry grey water are now to be coloured purple to distinctly show what that is contains grey water. An interesting article from The Australian in 08 November 2008 says that the pipes “supply water for purposes such as laundry washing, toilet flushing and irrigation, while water for kitchens, showers and bathrooms is carried in white or blue pipes.” Most grey water systems should come with some sort of purple hose system (although it may be just the bare basic hose system). 

Grey water systems:

There are currently about three different types of grey water systems commercially available, ranging from the quite simple to the horribly complex. Essentially, all Grey water systems serve the basic task of collecting grey water for the purpose of re-using it.

Grey water treatment system

Perhaps the most complex and expensive and option is what is basically know as a ‘Grey Water Treatment System’ Costing around $10,000, a Grey water treatment systems offers  the opportunity to store grey water beyond the regulated 24 hours period by treating and filtrating the water though various layers of sand and gravel. The resulting ‘grey water but not a greyer that normal grey water’ is then stored in another tank ready for use. Aside the cost, there are other downsides to this system. The size required to house all the tanks and filtration system is simply beyond the available space most inner city dwellings have to offer. In addition there is reputedly a fair amount of red tape one must wade through the get the system approved as they do need council approval.

However, obviously for the price you do get some pretty good benefits. The system allows the grey water to be safely used also within the home for purposes such as flushing the toilet, and in possibly laundry washing. They are usually an odourless and relatively silent system also, especially is a gravity fed system is used as opposed to a pump system. 

Grey Water Diversion System

Grey Water Diversion systems are possibly the most popular system used in homes. It can range from the simplest of methods as purchasing a cheap pipe attachment that diverts water from your washing machine pipe into a collection point, most likely bucket – up to systems with pumps and filters.

The simplest of diversion system shouldn’t cost more than $200 (check out Greenfoot’s step by step guide to building an easy system costing about $120 http://www.greenfoot.com.au/2006/11/23/build-your-own-grey-water-system/) and even that much is toward the top of the expense scale. These kinds of systems can connect washing machines to the garden and can basically remove the manual labour side of collecting and directing grey water.

Obviously you can spend a little more and attach pumps and filters to your system, again removing more of the manual labour side of grey water collecting. Pumps installed on diversion systems are great as they are only activated when waste water is diverted into the system, which then in turn pumps the water to wherever you need it to go. They also automatically turn off when the tank is empty.

Perhaps the greatest feature of this system is that, more often than not, it can be self installed. Parts are easily purchased through warehouse or plumbing companies and can be as elaborate and encompassing as you want and generally require little maintenance.

Manual bucketing

The cheapest but most manual system is simply using a bucket to collect water before it goes down the sink, for example under the shower while waiting for the water to warm up. Bucketing is a great way to safely irrigate your garden, lawns, and outdoor pot plants as you can completely control what chemicals and other nasties go into the water and where you put the grey water. Although it is by far the most laborious of systems, the $2 you spend on the bucket certainly makes it the most cost attractive. 

Rebates

Both the Federal government and most state government offer so sort of rebate on grey water systems or water saving devices. Check out aToMik Green's Rebate page to get a comprehensive list of rebates you may be eligible for. 

What To Do With Grey Water After 24 Hours Of Storage.

Through-out researching this, site after business after organisation reminded us that we cannot store grey water from more than 24 hours for a variety of reasons, however NOT ONE could tell us what to actually do with the water afterwards. After pestering the EPA and aToMik's local water authority with numerous emails and phone calls, pieces of clues were put together to establish what appears to be an answer. 

Grey water must never be put into your storm water drain for obvious reasons. The only safe way to dispose of 'old' grey water is by flushing it down your sewage system via the Overflow Relief Gully (ORG), which is the grated concrete mound that almost all residential sewage systems have outside 'behind' the toilet. Do not pour grey water into your toilet for health reasons. 

The may be harder than it sounds, especially if your system does not allow easy transportation of the grey water. If you cannot transport the water, it may be worth thinking about having some sort of flushing system installed onto your grey water system that is connected to the ORG which dirverts old grey water. 

The Do’s of Grey water:

• Do install a grey water treatment system only via a professional -  not only will it save you time, stress and effort but many rebates initiatives stipulate the system be installed by a registered plumber in order to be eligible for the rebate.
• Do monitor your soil’s pH levels, do smell test, and check up on ‘life forms’ like worms and garden bugs.
• Do watch your irrigation needs. If it doesn't need water, don't water it!
• Do try and disperse the water under the surface. Under service water system are as easy as a up-side-down soft drink bottle ¼ buried with a small hole in the lid.
• Do remember that there is a difference between grey water and rain water, especially when it comes to storage. 
• Do rotate grey water usage around your garden.
• Do think carefully about the products you use inside the house and what affect that will have outside e.g: disinfectants, hair dye, bleach, cleaners.
• Do filter out as many solids as you can like leaves and seeds.
• Do get to know grey water rules and regulations. Check out GMagazine's list of state based grey water regulations.
• Do try and use the waste water from baths, showers, hand basins and washing machines.
• Do wash your hands after every time you use grey water.
• Do place warning and “Do Not Drink” signs on all outlets of your grey water system
• Do ensure that all pipes that carry grey water are coloured purple. This is an requirement.

The Don’t's of Grey water:

• Don't store untreated grey water for more than 24hours – simply, it's against regulations. Don't feel you should water just because the grey water is available. Overwatering can can drown your plants and damage your soil.
• Don't allow pets or children to play in pooled grey water.
• Don't simply hose it around like you would when using mains water. Try to localise use to one area of your garden, and try to disband it under mulch or alternative subsurface.
• Don't use water that has been possibly been tainted with grease, bacteria, chemicals. Certainly avoid water spoiled by urine or faeces. See the section on Black Water.
• Don't let grey water wash into your neighbour’s property - nothing says neighbourly squabble like your waste water in the next door’s rose bush.
• Don’t use grey water on or near vegetable gardens if you plan to eat the crop raw or uncooked.
• Don’t continue use if you smell odours or your plants begin to look unhealthy.
• Don’t ever drink grey water or allow children or pets to drink it!