Credit: Illustration: Jamie Tufrey

- Advertisement -

A domestic garden is a sanctuary.

In our cities and towns of concrete and asphalt, a garden is a place for flowers and trees and birds, somewhere to meditate in solitude or celebrate with family and friends.

As if that's not enough, our gardens also help to keep our homes cool. But as water restrictions continue, our gardens wither. And if the predictions of climate scientists are correct, it's going to get worse.

"Greywater is the great untapped water resource in Australia," says John Grimes, chairman of the Australian Greywater Institute based in Canberra, an industry body recently formed to promote greywater reuse.

"A typical family uses around one thousand litres of water every day," he explains. "Not a single litre is re-used. Instead, it goes straight down the sewer."

Saving your garden with greywater may not be easy. While greywater is free to use, the cost of buying and installing a domestic treatment and irrigation system can exceed $10,000.

And there is often another forbidding obstacle: a bewildering labyrinth of rules, standards, principles, requirements, codes of practice, guidelines and by-laws.

Greywater re-use is governed by state and local regulations that vary greatly. Some local councils require a simple, one-page application; some even offer financial rebates. Others impose severe regulations that effectively prevent domestic greywater recycling.

The basics

Households produce two types of wastewater: sewage (sometimes known as blackwater) and greywater.

Greywater from the kitchen is contaminated with food waste, fats and oils — it should not be re-used.

However, you can use raw greywater from the bathroom and laundry to water thirsty gardens and treated greywater to flush toilets and wash clothes.

Recycling greywater decreases household water consumption by up to 40 per cent.

The most common method of recycling greywater requires only the use of a bucket to transport water from the bath, shower and washing machine to the garden.

A less common but more efficient solution is to divert greywater from the household plumbing to a subsurface irrigation system.

Health risks

Greywater diversion, though, must be carried out with care.

"It's a good practice, but people need to be aware of the harm they can do," says Michael Linich, a former lecturer in Life Sciences at the University of Newcastle and an expert on domestic wastewater management.

He says there are two major risks:

1. microorganisms
   Domestic greywater can be as contaminated as sewage, posing serious health problems.

   "The greatest risk of infection by microorganisms is through direct contact," explains Linich, "which can spread Hepatitis A and the viruses that cause gastroenteritis."

2. sodium salts
   Sodium salts from laundry detergents alter the pH of the soil, locking up nutrients so they are no longer available for plants, he says.

   Phosphates from laundry detergents can also leech into the soil, but buying phosphate-free detergents will prevent such contamination. Industry groups are now lobbying detergent manufacturers to remove sodium salts from their products.

To protect against infection and environmental damage, every state prescribes some basic rules for diverting greywater. For example, you must never use untreated greywater to water vegetable gardens or other plants destined for human consumption. Nor should you use it in areas where children play.

Greywater from washing machines may be heavily contaminated — so never divert water that has been used to wash nappies or other soiled clothing.

State authorities in Queensland, Victoria and Western Australia recommend that water only from the final rinse cycle should be used to water gardens.

If you carry greywater to the garden in a bucket, you should regularly change the areas that you water so any contaminants will be diluted by other water sources.

And if you divert greywater directly from the household plumbing, you should install a sub-surface irrigation system to prevent human contact.

Environment and land-use regulations stipulate that irrigation systems must be positioned so that they do not spread greywater to neighbouring properties.

To prevent overflow from flooding, you should never water gardens with greywater during rain or when the ground is already wet.

Treatment systems that remove contaminants before the water is re-used eliminate many of the risks of recycling untreated greywater.

However, they are more expensive to purchase, install and operate than simple diversion systems and they are subject to stricter regulations.

Domestic greywater is usually treated in two stages:

1. It is filtered.
   A coarse filter removes any debris from the water followed by another filter, often of sand and gravel, that removes other suspended solids.
2. The greywater is disinfected using ultraviolet light or sometimes with ozone.
   A less common but innovative method of treatment is to pass the water through reedbeds — small, artificial wetlands — where it is purified by microorganisms before being used for irrigation. Councils are generally less likely, though, to approve more complicated systems.

The state of greentape

In each state of Australia you can manually collect greywater from your bath, shower and washing machine to re-use in the garden, as long as you take the appropriate precautions.

But if you want to install a diversion or treatment system that requires a permanent connection to the household plumbing, well, it all depends on where you live.

There are a few regulations that apply to everyone:

• A licensed plumber must carry out any permanent changes to your plumbing and all materials must meet Australian standards.
• In every state, permanent greywater systems must be tested and approved for domestic use.

But just about everything else is a matter of chance.

Manufacturers must submit their systems for approval to the appropriate authority in each state: to the health department in New South Wales, South Australia and Western Australia, the Environmental Protection Authority in Victoria, the Department of Infrastructure and Planning in Queensland and the Tasmanian Department of Tourism, Arts and Environment.

There is no national coordination, though, and the list of approved systems is different in every state.

Where to begin

The place to start with any application to install a greywater system is your local council, which should be able to provide a list of approved systems in your state.

But approval for a particular system does not mean that you can just go ahead and install it. Local councils enact their own regulations and by-laws; their approval is also necessary.

Some councils process applications for free; others charge hundreds of dollars. Some require on-site inspections before final approval is made; others don't. And some process applications quickly, while others take months.

The regulations will also vary depending upon whether your property is connected to the sewage system or uses a septic tank.

Other authorities may also impose conditions on the installation or use of greywater systems.

Connecting overflow outlets from greywater systems to the sewer may require the permission of your local water authority. Irrigation systems may also be subject to environmental standards.

"It's a big issue," says Phil Krasnostein, technical director at Nubian Water, a Sydney-based manufacturer of greywater systems. He says that inconsistent regulations cost his company a lot of money. "It's so bad we can't even have a single national brochure for our products."

There are other problems, too. In Australia, domestic greywater re-use is a relatively new practice, with most states prohibiting all re-use until only a few years ago.

Problems

Often, appropriate regulations are simply not there. In their place, inappropriate regulations are applied — regulations that make no distinction between sewage and greywater that can be safely re-used.

"In most cases," Krasnostein says, "the applicable regulations are something like The Septic Tank Act, which is unsuitable for greywater systems."

In affluent suburbs, a combination of high-value gardens and high disposable incomes means that greywater systems are more widely used. In other areas, they are hardly used at all.

Krasnostein says, "Council officers are often young and inexperienced and have little understanding of the equipment that they are expected to approve."

As councils become more experienced and comfortable processing applications, he says, the problems often disappear.

Andrew Pearce, chief executive of New Water, a producer of greywater systems in Melbourne, believes there is a "political undertone" to the problems of regulation. He points out that whenever a greywater system is installed, water authorities lose income.

And water authorities are sometimes owned by state governments.

Grimes, who is also managing director of Perpetual Water, a Canberra-based manufacturer of greywater systems, says: "It's really important that there are regulations, but the current rules go beyond what is reasonable and are definitely there as trade barriers."

He describes the current policies as perverse: "When we bring it to the state governments, they ignore us."


Absurdities

The current regulations can sometimes produce absurd outcomes.

Pearce says that his company, New Water, applied to have one of their systems approved for use in Western Australia.

They recently received a reply: "The Department of Health would be willing to approve the system," it said.

He thought this meant that the application was successful, but he was wrong.

He says the department can't actually approve the system yet because the applicable guidelines won't be finished until the end of 2008. But at least they "would be willing" to do so.

Council approvals can be erratic and unpredictable.

When customers buy a system from Nubian Water, the company negotiates the sometimes complex application process on behalf of the consumer.

Occasionally, when an application is rejected, they will recommend that customers resubmit the application themselves — Krasnostein says that councils sometimes accept previously rejected applications when the individual homeowner resubmits them.

Everyone agrees on one thing: there should be consistent national rules governing the installation and use of greywater diversion and treatment systems.

Grimes believes systems should be subject to a national accreditation system. Once systems have been accredited, he says, homeowners should be free to install them anywhere on the simple condition that they notify their local council.

Pearce agrees that there should be a national standard but says that approval from council authorities is also necessary, as only they properly understand local land use. He stresses, however, that obtaining council approval must be quick and simple.

The future of greywater

Efforts to make the regulations more consistent are underway. The recent formation of the Australian Greywater Institute means that there is now a dedicated greywater industry group lobbying for national uniformity.

In November 2006, the National Health and Medical Research Council in conjunction with the National Water Quality Management Strategy released Australian guidelines (pdf here) for the reuse of domestic greywater.

But these guidelines are not mandatory: each state is free to adopt or ignore them as they choose.

Following the release of the national guidelines, the Australian Water Association, a group representing the Australian water industry, sent a roadshow around the country, led by their principal scientist, Diane Wiesner.

The purpose of the roadshow was to explain to state authorities the principles and application of the national guidelines. Wiesner says that the results were mixed.

"The states sometimes like to do their own thing," she explains.

In South Australia, local councils already follow uniform guidelines for approving greywater systems and every council charges the same fee.

"The national guidelines were developed to provide consistency between the states and we agree with that," says David Cunliffe, principal water quality advisor to SA Health.

He says South Australia plans to adopt the national guidelines and rescind their own.

New South Wales, too, claims to be making progress.

"We're really just about there," says Tony Bles, policy analyst at NSW Health. He says that state guidelines for domestic greywater re-use are currently under review and that, "New South Wales is moving towards the Australian guidelines."

A national system?

But moves toward national uniformity are only just beginning, and not everyone is satisfied.

"In some areas, the policy position is getting worse," argues Grimes. "The states are moving rapidly in different directions," says Krasnostein.

Further change is inevitable. The regulations are currently under review in several states. There is hope in the industry that the new federal government will provide greater support for water-saving technologies.

During the recent election campaign, the Australian Labor Party announced rebates of up to $500 and interest-free loans of up to $10,000 for domestic greywater systems.

Ongoing water shortages will continue to increase the political pressure on all levels of government to better support greywater re-use.

Stuart White, director of the Institute for Sustainable Futures at the University of Technology, Sydney, believes that greywater re-use will make a substantial contribution to our water conservation efforts.

"Properly managed, decentralised water recycling is probably the way of the future," he says.

But if you want to be part of that future today, you may experience pain in two places - your hip pocket and your neck.