Definition of a greywater diversion device

The definition of a greywater diversion device under the Plumbing and Drainage Act 2018 is:

• a diversion device with the characteristics mentioned in paragraph 1; and
• a filtering system that uses a coarse filter to remove solids from greywater.

For paragraph 1, the characteristics are that the device:

• directs and diverts greywater to sanitary drainage or a greywater application area;
• automatically diverts greywater from the facility to sanitary drainage if the facility does not work properly or at all; and
• allows the manual diversion of greywater from the facility to sanitary drainage.

Definition of a greywater treatment plant

The definitions under the Plumbing and Drainage Act 2018 is:

• a greywater treatment plant means a treatment plant installed on premises for treating, on the premises, greywater generated on the premises.

Note: all Greywater treatment plants must have an approval from the Queensland Department of State Development, Infrastructure and Planning.

External risks

• Ponding of greywater
• Run-off into neighbouring properties
• Odours
• Health risks

Internal risks

• Contamination of vegetables and fruits
• Run-off to and contamination of swimming pools
• Contamination of pets and children's play areas

Environmental risks

• Contamination of soils with phosphorus, sodium (salt) and nitrogen from laundry detergents
• Damage to soil structure or inhibiting plant growth by using bleaches, fats and preservatives in household products
• Over-saturation affecting soil or killing plants
• Over-fertilisation of native plants
• Odours from build up of bacteria in soil excess run-off during wet weather contaminating surface waters
• Contamination of groundwater
• Blocked pipes and drains due to low water usage.

Reducing health and environmental risks

• Greywater should only be used in the garden
• Bucket water or use a flexible hose
• Change the areas you use greywater regularly to minimise toxic build-up
• Choose household products that contain low levels of Nitrogen and Phosphorus (NP on packaging)
• Do not store untreated greywater. Use within 4 hours
• Use the cleanest greywater as a priority
• Don't use sprinklers with greywater; only use subsurface irrigation systems (i.e. directly into the topsoil, below 100mm)
• Alternate with tank water to dilute toxic build-up
• Don't allow greywater to enter your neighbour's block. Make sure the greywater does not create a nuisance (i.e. generate odours, ponding or health risks)
• Don't put greywater on food plants (herbs, vegetables or fruit trees)
• Don't put greywater on lawns where children or pets are likely to play
• Don't irrigate with greywater during periods of wet weather
• Don't allow greywater to enter the stormwater system
• Use vinegar instead of fabric softener in your final rinse – it's kinder to your plants

Greywater may be permitted for use in non-sewered areas, and since the amendments to the Plumbing and Drainage Act 2018 in August 2006, the use of greywater is now permitted (other than kitchen greywater) within sewered areas, under certain conditions to water domestic gardens and lawns.  Keeping in mind that greywater is a source of salts and other chemicals as well as disease-causing micro-organisms such as bacteria, protozoa, viruses and parasites.

Please note:

• that use of greywater is regulated and can attract a significant fine if contravened.
• to install an on-site sewage treatment facility or greywater treatment facility you must get approval from Council (refer to page 4 of this information sheet).
• you must use a licensed plumber to install diversion devices.

How to use greywater safely and effectively

Greywater use can be a sustainable and adequate source of water for lawns and gardens during dry spells.  When using greywater, it is recommended that the home owner is vigilant and considers the following suggestions:

• when bucketing or using a flexible hose, spread greywater evenly by emptying in different locations or continuously moving the hose around.  This will limit the potential for ponding or run-off;
• do not empty or position a flexible hose near property boundaries, stormwater pits or swimming pools;
• do not use greywater when it is raining or use on ground that is already saturated;
• avoid human contact and do not use around children's play areas;
• do not store greywater for any period of time, as bacteria will breed quickly and turn greywater septic, in as little as 20 minutes, causing potential odours and health risks;
• apply greywater to suitable plants and do not use on edible parts of vegetables or fruits;
• choose laundry detergents with low phosphorus, sodium and nitrogen contents;
• when the system is approved and the greywater diversion valve and irrigation system installed, ensure the filter on the diversion valve and irrigation links are clear and working effectively; and ensure the approved greywater system is regularly maintained and installed as per its design approved by Council.

Using greywater for gardening from homes in sewered areas

• 'Home' means a single detached dwelling not sited on commercial or community property.
• 'Sewered' means you are connected to the Council's sewerage system (i.e. no septic or on-site treatment).
• 'Greywater' is the wastewater from the shower, bath, basins, laundry and kitchen.  It does not include wastewater from toilets or bidets which is called 'blackwater'. Greywater from kitchens may have more contaminants than other types and should not be used in the garden.

*Greywater contains micro-organisms such as bacteria, protozoa, viruses and parasites and also contains nutrients and salts from detergents and soaps.  If not carefully managed, it has the potential to cause health risks and environmental problems.  It is illegal to recycle greywater if it causes an odour for neighbouring properties, ponds or causes run-off, or if it presents a danger or risk to health.

PDA: Plumbing and Drainage Act 2018

QPWC: Queensland Plumbing & Wastewater Code

SReg: Standard Plumbing & Drainage Regulation 2003

How greywater will affect my garden soil and plants

Contaminants in greywater can have damaging effects on soils, plants and animals, groundwater and local waterways. Trial greywater use on a small section of the garden to see what effect it has on the soil and the plants before using all over garden. To avoid causing long-term damage to your soil and plants, move the hose around regularly rather than leaving it to discharge to the same place.

Clay soil absorbs water at a slower rate than sandy soil; therefore it is recommended that greywater is applied slowly to prevent ponding or run-off from the garden surface.

Some plants may be affected by the change in soil conditions caused by using greywater, so an occasional use of tank water as an alternative is a good way to avoid such problems. Identify the sensitivity of plant species (especially native plants) to contaminants found in greywater before using it. Ask your local nursery for more information.

Consider testing your soil regularly for pH, salinity, conductivity and chemical levels. This will tell you the suitability of the soil to absorb greywater, as well as allowing you to monitor the ongoing effects of the greywater on the soil environment and plants. See your local nursery or hardware store for more information.

Property safety when neighbours are using greywater

As long as your neighbour is following the guidelines in this brochure, appropriate reuse of greywater is not considered to be a health threat to neighbouring properties. Any unhealthy use of water becomes subject to health department and plumbing regulations and can attract contravention orders and associated fines.

Under the legislation there are offences and potential fines for illegal plumbing installations and misuse of greywater. Offences under the Plumbing and Drainage Act 2018 include the following:

• Installation of a greywater diversion device or treatment plant without prior Council approval;
• Installation of a greywater diversion device or treatment plant without a current plumbers and drainers licence; and
• Installation of a non-approved greywater diversion device or treatment plant.

The home owner must ensure:

• The greywater does not cause an odour;
• The greywater does not pond or run-off causing a danger or health risk to anyone; and
• The kitchen waste is only discharged to Council's sewerage system.