greywater reuse guidelines - eservice.alburycity.nsw.gov.au

Greywater Reuse Guidelines

March 2012

GREYWATER REUSE GUIDELINES

TABLE OF CONTENTS

1 INTRODUCTION .................................................................................................................... 1

2 WHAT IS GREYWATER? ...................................................................................................... 2

3 ADVANTAGES AND DISADVANTAGES OF GREYWATER REUSE .................................... 2

4 SOURCES OF GREYWATER ................................................................................................ 2

5 METHODS OF COLLECT ING GREYWATER ........................................................................ 3

5.1 MANUAL COLLECTION OF GREYWATER ................................................................ 3

5.2 GREYWATER DIVERSION DEVICES (GDD) .............................................................. 4

5.2.1 GRAVITY GREYWATER SYSTEM S ............................................................... 5

5.2.2 PUMP GREYWATER SYSTEMS ..................................................................... 5

5.2.3 CONDITIONS OF APPROVAL FOR USING GDDS ......................................... 6

5.2.4 GDD CHECKLIST ........................................................................................... 7

5.3 GREYWATER TREATMENT SYSTEM (GTS) .............................................................. 7

5.3.1 CONDITIONS OF APPROVAL ........................................................................ 8

5.3.2 GREYWATER TREATMENT SYSTEM INSTALLATION CHECKLIST............. 8

APPENDICES ................................................................................................................................. 9

A.1 GUIDELINES FOR GREYW ATER REUSE IN HOUSEHOLDS .............................................. 9

A.2 GENERAL INFORMATION FOR GREYWATER REUSE ....................................................... 9

GREYWATER REUSE GUID ELINES MARCH 2012

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1 INTRODUC TION

Potable drinking water sources in NSW are becoming scarce with additional demands being

placed on our limited water supplies as the population increases. Domestic g reywater from

single residential premises is considered a potential water source which may be reused for

watering gardens, lawns (by surface irrigation installed 100mm below ground level) and toilet

flushing, and therefore , greywater reuse can reduce the de mand on potable water supply .

AlburyCity Council recognises that the communitys interest in water reuse around the home is

increasing, possibly as a result of climate change and the drought conditions over the past few

years, water restrictions and the greater choice of water reuse/diversion devices available. In

accordance with the prin ciples of sustainability , domestic water reuse is encouraged when

conducted in a safe and environmentally sustainable manner.

The amount of wastewater generated by a household will vary greatly according to the

dynamics of the household and is influenced by factors such as the number of occupants, the

age of the occupants, lifestyle characteristics and water usage patterns. Of the total water us e d

in a typical residential household, approximately 37% can be utilised again, i.e. reused .

These guidelines provide assistance on the use of greywater in single residential households .

The reuse of greywater by a Greywater Treatment System (G TS) where more than one dwelling

is located on a block i.e. groups of town houses and multi-unit dwelling households, is a lso

permitted providing the system is installed and used in accordance with the Interim NSW

Guidelines for Management of Private Recycled Water Schemes .

As the amount of gre ywater generation varies, it is important to determine how much greywater

is avai lable and how much can b e applied to reuse situations. The chart below indicates an

approximate percentage of where water is used daily in a domestic residence ; the shaded areas

indicate greywater averages.

ALBURY AVERAGE RESIDENTIAL WATER CONSUMPTION

BA SED ON 2006/07 (i.e. NO WATER RESTRICTIONS)

Location of use % Litres/day

Internal

Toilet 19 158

Kitchen 4 35

Hand Basin 3 25

Bath/Shower 20 163

Laundry 14 112

External

Garden, Lawns etc. 40 329

TOTAL 100 822


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2 WHAT IS GREYWATER?

Greywater is defined as wastewater generate d from bathrooms and laundries. Although

classified as greywater, kitchen water can contain food particles, grease, oils and fats and

therefore its reuse is not recommended without appropriate treatment .

3 ADVANTAGES AND DISADVANTAGES OF GRE YWATER REUSE

Advantages of Greywater Reuse

Provides an alternative water source for the irrigation of gardens and lawns during

drought and water restrictions.

Reduce s potable water consumption.

Reduce s potable water costs.

Disadvanta ges of Greywater Reuse

Increased potential for pollution and potential health and environmental issues if

greywater is not correctly used .

Initial cost of greywater system, including installation .

Ongoing maintenance , especially for GTS.

4 SOURCES OF GREYWATER

There are two primary sources of greywater in households including bathroom and laundry

wastewater.

Bathroom greywater (bath, basin, and shower) contributes on average , 23 % (or 188

litres/day) of the total useable wastewater volume in a typical hou sehold. Bathroom greywater

can be contaminated with hair, soaps, shampoos, hair dyes, toothpaste, lint, nutrients, body

fats, oil and cleaning products. It may also contain some faecal contamination (and the

associated pathogens) through body washing.

Laundry greywater (washing machine and laundry tub) contributes on average to 14 % (or

112 litres/day) of total usable wastewater volume in a typical household. Wastewater from the

laundry varies in quality from wash water to rinse water. Laundry wastewater ca n be

contaminated with lint, oil, greases, laundry detergents, chemicals, soap, nutrients and other

compounds. It may also contain faecal contamination (and the associated pathogens) through

washing contaminated clothes.

Greywater generated from the laun dry is often the easiest source of greywater to access,

although it is usually more contaminated than bathroom wastewater. The final rinse water from

the laundry is recommended to be reused and must not be stored for more than 24 hours

without appropriate treatment .


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5 METHODS OF COLLECTING GREYWATER

In residential areas, greywater may be collected and distributed in one of three ways:

1. Manual diversion methods e.g. buckets and temporary holding devices (See Section 5 .1 ) .

2. Greywater Diversion Devices (GDD) fitted to the plumbing fixtures (See Sect ion 5 .2 ) .

3. Greywater Treatment Systems (GTS) (See Section 5.3) .

5.1 MANUAL COLLECTION OF GREYWATER

Greywater may be collected from the washing machine, laundry trough, shower, hand basin or

bath by use of a bucket o r other temporary holding device and then used to water gardens,

lawns etc . This water may also be used to manually flush toilets by pouring directly into the toilet

bowl.

The use of a hose manually fitted to a washing machine is also permitted to transfer greywater

generated to an outside temporary holding device such as a wheelie bin or tank. The captured

water can then be bucketed out of the temporary holding device and reused (see photo below).

Note : G reywater transferred to the outside holding device must not be stored for longer

than 24 hours.

When manually collecting and using greywater, consideration should be given to the

following points.

Caution should be taken when lifting and carrying buckets of water.

Select garden friendly de tergents that are biodegradable and low in phosphorus, so dium,

boron, chloride and borax.

Reuse greywater in various locations i.e. do not water the same area repeatedly.

Monitor plant and soil reaction .

Occasionally irrigate the area with drinking or rain water to flush contaminants from the

soil.

Wash your hands after handling greywater.


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DO NOT

Store greywater more than 24 hours.

Reuse greywater for irrigation during periods of rain .

Use in areas accessible to children or pets.

Reuse greywater generate d from the washin g of nappies or soiled clothing .

Reuse greywater when a re sident has diarrhoea or is sick .

Reuse greywater con taminated by strong cleaning chemicals.

Reuse greywater to top -up ra inwater tanks or swimming pools.

Wash driveways, paths or c ars.

Allow greywater to flow into stormwater drains.

Use on vegetables or fruit (especially those that are not cooked).

Let greywater go beyond your property boundary.

5.2 GREYWATER DIVERSION DEVICES (GDD)

In NSW greywater diversion devices must have a Water Mark identification bearing the

appropriate symbol see image below. It is illegal to use an unmarked GDD in your household

plumbing system. GDDs have conditions of approval for their use see conditions of approval

(Section 5.2.3).

A GDD allows the redirection of household greywater through an approved specialised

plumbing fixture to a sub-surface irrigation system installed 100mm below surface level .

There must be a buffer distance of one metre from the property boundary to the irrigation

system.

Greywater systems can be either gravity or pump driven. A simple sub -surface irrigation system

could be used which consist s of a pipe network to transport the grey water to targeted areas of

the garden or a water spike/dripper distribution head as shown below.


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Greywater flows can be manu ally controlled by a hand activated tap or switch, allowing the

greywater discharge to be directed to the location to be watered. When not required the

greywater shall be diverted to the sewer.

If the diverter remains on all the time, overwatering has the potential to significantly damage

plants and soil.

5.2.1 Gravity G reywater System s

These systems are most appropriate for p roperties that slope away from the house to the

garden or lawn area. In these systems, gravity provides pressure to move the water from the

house to the irrigation system. The flow of greywater is usually activated through a tap or a

switch. Some gravity d iversion systems include a surge tank (see image below) while others

feed straight into the subsurface irrigation system.

Note: If a surge tank is used it must not store greywater for any longer than 24 hours.

If a surge tank is used it must have the following features:

Must be installed by a licensed Plumber.

Must be vented.

The overflow line must be connected to the sewer via a water seal trap .

The scour l ine must be connected to sewer.

All access openings to the tank must be sealed and vermin proof.

5.2.2 Pump Greywater Systems

Pump diversion devices can only be installed where a Council sewerage system is available.

They can be used when the garden or lawn area is uphill away from the house, or the area is

too flat for a gravity system to ope rate . A pump is installed to pump grey water from the diversion

device and surge tank to the area that is to be irrigated.

This type of system incorporates a surge tank in all applications, to capture and control the flow

of greywater to the garden during sudden surges, such as emptying a bathtub. The greywater

should be screened as it enters a surge tank for distribution by a pump to the sub -surface land


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application system. The coarse screens must be cleaned regularly and the surge tank flushed

periodically. The surge tank must not store greywater any longer than 24 hours .

The following images are examples of pump diversion devices and their filters.

5.2.3 Conditions of a pproval for using GDDs

Under Section 68 of the NSW Local Government A ct 199 3, domestic greywater diversion is an

activity that requires the approval of the Council and therefore requires the following conditions

to be addressed.

The GDD is installed by a licensed plumber.

The GDD is installed in accordance with the NSW Code of Practice for Plumbing and

Drainage 3rd Edition 2006 .

The GDD is operated in accordance with the requirements of NSW Health Greywater

Reuse in Sewered Single Domestic Premises guidelines.

However, the Local Government (General) Regulation 2005 - Regulation 75A states domestic

greywater diversion may be carried out without the prior approval of Council if:

a) It is carries out in accordance with the Plumbing and Drainage Code of Practice, and

b) A sewage management facility is not installed on the premises conce rned, and

c) The following performance standards are achieved:

i. the prevention of the spread of disease by micro -o rganisms,

ii. the prevention of the spread of foul odours,

iii. the prevention of contamination of water,

iv. the prevention of deg radation of soil and vegeta tion ,

v. the discouragement of insects and vermin,

vi. ensuring that persons do not come into contact with untreated sewage of effluent

(whether treated or not) in their ordinary activities on the premises concerned,

vii. the minimisation of adverse impacts on the amenity of the premises concerned and

surrounding lands.


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Where a GDD is installed on a single residential property, the plumber or property owner shall

notify Council to ensure that a meter with an integral check valve is installed on the water supply

service to the property. If the meter has to be replaced and the property has a standard sized

(20 or 25mm) water meter, AlburyCity Council will fit a new meter with an appropriate backflow

prevention device free of charge. Property owners with large water mete rs (32mm+) will need to

install an appropriate backflow prevention device on the house side of Councils water meter at

their own cost.

5.2.4 GDD Checklist

The following checklist can be used when installing a GDD:

Engage a licensed plumber to undertake all plumbing works

Install a water mark approved diversion device. The device should be stamped with the

appropriate symbol

Diverted greywater must be to subsurface irrigation on ly. I rrigation lines must be a

minimum of 100mm below the ground surface

Ensure the irrigation area is such that there is adequate buffers between the irrigation

line and the property boundary so that greywater will not runoff or seep into the

adjoining property

Use a filter on the subsurface irrigation lines to prevent blockages and the fil ter should

be cleaned regularly

Notify Council of a greywater diversion device installation so that the water meter can

be checked to ensure it is fitted with an integral check valve.

Insure all overflows or excess greywater is discharged to the city s sewer system.

5.3 GREYWATER TREATMENT SYSTEM (GTS)

A GTS collects, stores, treats and can disinfect all or any of the sources of greywater to the

standards specified in the NSW Health Accreditation Guidelines for GTS . Where the greywater

is not disinfected it may only be utilised in a properly designed subsurface irrigation land

application system. Where the treated and disinfected greywater meets a 30cfu thermo -tolerant

coliform/100mL disinfection criteria it can be utilised by surface irrigation in a properly designed

land application area. Where the treated and disinfected greywater meets 10cfu thermo -tolerant

coliform/100mL disinfection criteria it can also be used for toilet and urinal flushing and laundry

use.

A GTS requires installation and operation approval from Council . This type of system must be

accredited by NSW Health and requires Council approval to install and operate under the Local

Government Act 1993 and its Regulations. GTSs are required to be regularly main tained in

accordance with their service manuals by an appropriately qualified service contractor.


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Servicing is arranged under a service contract (a legislative requirement) and service

certificates must be provided to the Council and the property owner at regular intervals.

5.3.1 Conditions of Approval

A GTS is defined as a waste treatment device by the NSW Health. Under Section 68 of the

Local Government Act 1993 and the Local Government (General) Regulation 2005 an owner of

a premise must obtain approval from Council to install, construct or alter such a waste treatment

device. Approval must also be obtained prior to installation of the GTS for its irrigation area.

Approval to install must be obtained from Council by submitting a detailed description of the

installation in accordance with Section 68 of the Local Government (General) Regulation 2005

for the greywater treatment system. Council Officers will assess the application to ensure it

complies with the requirements of NSW Health and the NSW Code of Practice for Plumbing and

Drainage 3 rd Edition 2006 . An assessment of the disposal method of the proposed system will

form a major component of the application. Legislative requirements will need to be met to

ensure that the GTS is not likely to cause a ny adverse health or environmental impacts and that

sustainable greywater reuse can be achieved on site.

During the installation of a GTS, Council Officers will inspect the system to ensure it has been

installed in accordance with the conditions of the Approval to Install issued by Council.

5.3.2 Greywater Treatment System Installation Checklist

In order for a greywater treatment system to achieve compliance the following standards must

be met:

All greywater must be treated and accredited to the stan dards outlined by NSW Health .

All plumbing work must be carried out by a licensed plumber and meet the requirements

of the NSW Code of Practice for Plumbing and Drainage 3rd Edition 2006 . Council

approval is required for these works.

There must be sufficient land available for the disposal of the treated greywater

The site should not be restricted by size, rock, bushland, waterways, or built structures to

allow sufficient area for dispersal of treated greywater in a fixed irrigation system.

The greywater will not be used for recreational activities.

The greywater will not be used for the watering of fruit or vegetables, washing vehicles

o r for animal consumption.

Standard tap fixtures are not installed.

The irrigated area does not have the potential to discharge to adjoining properties.


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APPENDICES

A.1 GUIDELINES FOR GREYW ATER REUSE IN HOUSEHOLDS

Local Government Act 1993 .

NSW Code of Practice for Plumbing and Drainage 3 rd Edition 2006 .

NSW Health Greywater Reuse in Sewered Sin gle Domestic Premises April 2000 .

Department of Energy, Utilities and Sustainability, NSW Guidelines for Greywater Reuse

in Sewered, Single Household Residential Premises.

NSW Health Domestic Greywater Treatment Systems Accreditation Guidelines .

A.2 GENERAL INFORMATION FOR GREYWATER REUSE

Maintaining healthy plants and soil when using greywater.

The level of greywater reuse in the garden needs to be balanced with the amount of water,

solids and nutrients that the plants and the soil in the garden can a bsorb.

If excess grey water is applied:

Excess nutrients may run off or leach through the soil and enter waterways, contributing

to algal blooms a nd other water quality problems

Soils and plants may become water logged and adversely affect plant growth

So ils can become physically clogged with organic and suspended material or damag ed

by contaminants in the greywater

G reywater may contribute to rising watertables and subsequent salinity problems in some

areas already affected .

When using greywater on garde ns or lawns, consideration of the type of household detergents,

soaps, or other chemicals used is required. Greywater may contain contaminants that will harm

plants and soils.

Choose environmentally friendly detergents, cleaners and laundry detergents .

What goes into the grey water used by the household may enter the environment . Shampoos,

laundry detergents and cleaning agents all contain chemicals that change the quality of

grey water. To minimise their impact, choose biodegradable detergents and cleaners that are

low in salt, phosphorous and harsh chemical agents.

Salt is an ingredient used in washing powders as a filler. There is generally le ss salt in

concentrated powders and even less in liquids. Minimising the salt content of the greywater is

impo rtant to prevent soil salinity and damage to the soil structure .


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The typical nutrient loads that can be applied to the soil by irrigating with greywater are similar

to those used in common fertiliser. The reuse of greywater, therefore, has the potential to

reduce the need for fertilizer application on gardens and lawns. The application of nutrients

through a managed greywater irrigation process is preferred, as the nutrients will be applied

gradually and will reduce the risk of nutrients being spread during wet weather events.

Too much phosphorous and other nutrients in greywater can be toxic to some plants, most

notably native Australian plants. Caution on plant selection and greywater reuse is advised.

Soaps

Fats in greywater generated from soaps and fabric softeners can result in the soil becoming

water resistant. In these circumstances the soil may benefit from an application of a soil

rewetting agent every six months.

Bleaches and Disinfectants

Bleaches (such as hair dyes and nappy wash), disinfectants (including eucalyptus and tea tree

oil) and germicides (certain detergents and cleaning products) can adversely affect the health of

soils by killing natural organisms. Do not reuse the greywater produced when cleaning

chemicals in the bathroom or lau ndry, or when hair dye, disinfectants, germicide or other

chemicals have been used. In these circumstances divert the water to the sewerage system.

When using greywater regularly check gardens and lawns for:

Signs of unhealth y soil, lawn and plants inclu ding d amp and bogg y ground after irrigation .

Surface ponding or run off of irrigated water.

Presence of unu sual odours.

Changes in soil structure.

If any of the above signs are noticed, re -assess the amount of greywater that is being used and

check that the irrigation distribution system is working correctly or cease the use of greywater in

the area affected.

greywater reuse guidelines - eservice.alburycity.nsw.gov.au

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