ELECTRONIC VERSION

EVERY DROP IS PRECIOUS: GREYWATER AS AN ALTERNATIVE WATER SOURCE

RESEARCH BULLETIN NO 4/98

GLENDA EMMERSON

QUEENSLAND PARLIAMENTARY LIBRARY Publications and Resources Section

BRISBANE July 1998 ISSN 1325-1341 ISBN 0 7242 7838 9 © Queensland Parliamentary Library, 1998

Copyright protects this publication. Except for purposes permitted by the Copyright Act 1968, reproduction by whatever means is prohibited, other than by Members of the Queensland Parliament in the course of their official duties, without the prior written permission of the Parliamentary Librarian, Queensland Parliamentary Library.

Inquiries should be addressed to: Director, Publications & Resources, Queensland Parliamentary Library, Parliament House, George Street, Brisbane. Director: Ms Mary Seefried. (Tel: 3406 7116)

Information about Research Publications can be found on the Internet at: http://www.parliament.qld.gov.au/library/research/index.html ABSTRACT Less than 1 per cent of the total water on the planet is readily available for human use.1 Some 26 countries already have more people than their water supplies can support. In some of these countries, a litre of water costs four to five times that of a litre of petrol. Australia’s water supply has not reached such a critical stage, but increasing demands on water and an ever-increasing population means that water supply is becoming a serious issue.

Alternative sources of water can potentially save significant amounts of precious drinking water. One alternative source of water is greywater. Greywater is the water that goes down domestic bathroom and laundry drains. If this water is diverted for relatively safe applications such as garden irrigation, then a family can reduce their water usage by around 30-50 per cent, obviously a significant saving. With an increasing number of people paying for each drop of water they use through water meters, systems offering savings are going to become important. Greywater reuse also offers environmental benefits. Less nitrogen and phosphorous are released into waterways and hence may reduce the occurrence of algal blooms.

Despite the opportunities offered by greywater reuse systems, they cannot be viewed as a water conservation panacea. A level of caution should be exercised with their use. Greywater has the potential to contain significant contaminants. Hence public health and the environment may be at risk. In addition, the current low cost of water may make the installation of such systems uneconomic.

Greywater reuse systems are used in Queensland, however the current legislation generally prohibits the use and installation of such systems. Many people are unaware that their use of greywater is potentially illegal unless permission from the local authority has been obtained. The Queensland Government is currently reviewing its legislation on greywater reuse.

This Bulletin is a review of existing information and scientific data as it pertains to the reuse of greywater as a water conservation measure. Throughout the Bulletin, specific issues that warrant further research are highlighted. Technologies available for greywater reuse applications are discussed. Also reviewed are the current regulatory, planning and management issues affecting the use of greywater reclamation systems.

1 D Rowe and I Abdel-Magid, Handbook of Wastewater Reclamation and Reuse, Lewis Publishers, New York, 1995, Preface. CONTENTS

1. INTRODUCTION...... 1

2. SOURCES OF WATER IN QUEENSLAND ...... 3

3. USE OF WATER IN AUSTRALIA AND QUEENSLAND ...... 4

3.1 AUSTRALIA ...... 4

3.2 QUEENSLAND ...... 5

3.3 HOW MUCH WASTEWATER DOES QUEENSLAND PRODUCE EACH DAY? ...... 7

4. WHAT IS GREYWATER?...... 7

4.1 WHY USE GREYWATER? ...... 8

4.2 GOVERNMENT RESPONSES TO WATER CONSERVATION AND REUSE ...... 9

4.3 WASTEWATER REUSE OPTIONS ...... 11

4.4 ACCESSING GREYWATER...... 12

4.5 GREYWATER QUALITY ...... 12 4.5.1 Microbial ...... 13 4.5.2 Chemical...... 14

4.6 METHODS OF GREYWATER REUSE...... 14 4.6.1 Types of greywater systems ...... 15

5. ADVANTAGES AND DISADVANTAGES OF GREYWATER REUSE ... 16

5.1 SEWAGE = POLLUTION = PUBLIC HEALTH DANGER ...... 16 5.1.1 Public health ...... 16 5.1.2 Mosquitoes and vermin...... 17 5.1.3 Multiple Users ...... 17 5.1.4 The reliability of owner maintained systems...... 18 5.1.5 Reduced flows to the sewerage system...... 18 5.1.6 Concerns with greywater use for toilet flushing ...... 19 5.1.7 Flexibility of water use...... 19 5.1.8 Summary ...... 20

5.2 ENVIRONMENTAL CONSIDERATIONS ...... 20 5.2.1 Water Conservation ...... 21 5.2.2 Effects of applying greywater to the soil...... 21 5.2.3 Contamination of the water table ...... 21 5.2.4 Aesthetics...... 22 5.2.5 Environmental awareness and involvement...... 22

5.3 CURRENT COST OF WATER AND REUSABLE GREYWATER IN AUSTRALIA...... 22 5.3.1 Cost of greywater systems ...... 23 5.3.2 Cost to the community...... 24

6. PUBLIC ACCEPTANCE OF GREYWATER REUSE ...... 25

7. GREYWATER REUSE OVERSEAS...... 26

7.1 THE UNITED STATES...... 26

7.2 JAPAN...... 27

8. REGULATION OF THE USE OF GREYWATER...... 28

8.1 COMMONWEALTH ...... 29

8.2 STATES AND TERRITORIES ...... 30 8.2.1 Australian Capital Territory ...... 31 8.2.2 South Australia...... 31 8.2.3 Western Australia ...... 31

8.3 QUEENSLAND...... 32 8.3.1 Legislation...... 33

8.4 GUIDELINES AND POLICIES DEVELOPED BY OTHER STATUTORY BODIES AND ASSOCIATIONS...... 35

9. QUEENSLAND GOVERNMENT POLICY DEVELOPMENT...... 35

9.1 GREYWATER POLICY OPTIONS PAPER...... 35

9.2 INTERIM GUIDELINES FOR REUSE AND DISPOSAL OF RECLAIMED WASTEWATER37

9.3 QUEENSLAND WASTEWATER REUSE STRATEGY ...... 37

10. CONCLUSION...... 37

BIBLIOGRAPHY ...... 39

GLOSSARY...... 45

APPENDIX 1: ADVANTAGES AND DISADVANTAGES OF POLICY OPTIONS...... 47

Every Drop is Precious: Greywater As An Alternative Resource Page 1

1. INTRODUCTION

Water is the driving force of all nature - Leonardo da Vinci

Water is one of the most valuable natural resources we have. It is vital to life. We live on one of the driest continents in the world, yet Australians often take water for granted. For most of us, water is available at the turn of a tap. No thought is given to where our water is coming from, the cost of providing it and the importance of water to the environment. However, water is something we all need to think about, particularly our use of it and the consequences of actions that result in damage, such as pollution, to natural water resources.

Water has played a pivotal role in the development of Queensland as well as contributing significantly to the quality of life enjoyed by the community. Our state is the fastest growing state in Australia. This growth is placing increasing pressure on our water resources. In some areas, water availability has reached a critical stage. Areas such as Townsville and south-east Queensland are currently secure against the effects of drought because of the construction of water storage facilities, however in other parts of the state, demands for water equal or exceed existing supplies.2

In order to assist in conserving water resources3, the federal, state and local governments are reviewing the way in which we use and pay for our water.4 A

2 Queensland. Department of Primary Industries, State Water Conservation Strategy: A Discussion Paper, DPI Water Resources, Brisbane, September 1993, p 1.

3 There are many ways water can be conserved. Rainwater tanks can be installed in order to reduce the demand from the reticulated water system for use in the garden or for the filling of pools. Flow reduction devices or water conserving appliances can be installed in homes. Less than 1 per cent of the treated drinking water produced is actually consumed by people. A large proportion of water is used outside the home on gardens, pools, pathways, driveways and cars. Many current external water use practices can be changed which will reduce water use without affecting our lifestyle. For example, mulching gardens can reduce evaporation by up to 73 per cent. Watering of mulched plants is therefore more efficient. Allowing grass to grow longer, watering less often and using a timer on a sprinkler can greatly reduce water use. Many other options and strategies are also available to householders wishing to more effectively use water and, as a result, reduce water consumption. Many states are actively encouraging water conservation through Waterwise campaigns.

Water rationing and sprinkler bans are not uncommon in many towns and cities across Queensland. There has already been a shift towards the adoption of water efficient or water conserving appliances such as dual flush toilets and low flow shower roses. The introduction of the user pays principle and the subsequent installation of water meters has resulted in many people becoming more aware of their water use. 4 Under Chapter 7C of the Local Government Act 1993 (Qld), a number of Queensland councils are required to assess a user pays system for water by the end of 1998. If the review agrees Page 2 Every Drop is Precious: Greywater As An Alternative Resource

1992 Industry Commission study recommended that water prices reflect the cost of provision. In addition, it was recommended that users of water pay for all water consumed.5 This approach to the pricing of water was supported by Hilmer’s National Competition Policy Review6 and the Council of Australian Government’s (COAG) investigation of the water industry. Such a system potentially overcomes many of the limitations existing under the past system which was based on property values and not actual water use.7 Under the user-pays system, consumers can be encouraged to use less water through financial deterrents. In 1992, just over half (56%) of the State’s urban water consumers had a water meter installed, with 75% of these used as a basis for water charging.8 A Local Government Association study into the effectiveness of water meter introduction throughout Queensland published in November 1997, found almost all metered districts reported drops of up to 30 percent in demand for water in the initial year of meter implementation.9

As of 1 July 1997, all Brisbane residents became part of a water meter system which employs this user-pays principle. Shires that have implemented user-pays or consumption based water pricing policies include: Gatton; Brisbane; Toowoomba; Hervey Bay; Maroochy; Stanthorpe; Hinchinbrook; and Ipswich Councils. The implementation of metered systems throughout Queensland is forcing people to become acutely aware of their water usage, and therefore water efficiency.

Concurrent with our increasing need for water, the disposal of our sewage has become a significant environmental problem. The sheer volume of waste requiring treatment is a major problem for water authorities and the environment. The traditional response to sewage management has been a system based on minimal treatment and discharge into receiving waters, such as oceans and rivers. With existing technology it is possible to treat the water in sewage to levels required for any of the current applications for water. The concepts of treating and reusing urban wastewater is not new - it is said the water in the Rhine River passes through

that a user-pays system is appropriate then the system is required to be implemented by 1 July 2000. 5 Industry Commission, Water Resources and Waste Water Disposal, Report no 26, AGPS, Canberra, 17 July 1992, APP no 239 of 1992, p 3. 6 F G Hilmer, M R Rayner and G Q Taperall, National Competition Policy: Report by the Independent Committee of Inquiry, AGPS, Canberra, August 1993. 7 The traditional method of charging for water through out Australia was based on property values and base allowances. Consumption in excess of the base charge was charged at higher rates at the level used. This system had been operating for many years. It was easily argued that the property based system is not reflective of the cost of supplying water and provides little incentive for users to be more water conscious and hence efficient. Property values do not bear any relationship to actual water usage. 8 K Jones, T Lewis, and K Aitken, “Waterwise Queensland The Joint Venture”, Water - Every Drop is Precious, the 15th Federal Convention of the Australian Water and Wastewater Association, Hotel Conrad, Gold Coast, 18-23 April 1993, Volume 1, pp 268-274, p 269. 9 J Bevan, “Dry areas wiser by the meter”, Courier Mail, 24 November 1997, p 4. Every Drop is Precious: Greywater As An Alternative Resource Page 3 around eight people’s kidneys before it reaches the North Seas.10 However, reuse of wastewater as a public policy in Australia has not yet been thoroughly investigated.

Wastewater reuse provides us with the most reliable supply of water of all available options,11 since this is the only water resource that increases along with the population.12 By choosing water reuse as an option, the demand on the water supply, sewage and hence wastewater systems is reduced, the need for improvement of these systems is delayed and potentially abated, the nutrient load in waterways can be reduced and if the resource created replaces water removal from rivers, the base flows of natural ecosystems can be improved.

Wastewater can be reused for irrigating residential properties, golf courses, public parks, crops, flowers and forests. It can be used for toilet and urinal flushing in residential and commercial buildings. Ornamental landscaping can also make use of recycled water in water features such as fountains, pools and waterfalls. Industrial applications of reused water include airconditioning, cooling, general wash down and street cleaning. Fire protection is another potential use option, as is the use of reclaimed water in construction activities such as making cement.

The wastewater reuse options so far mentioned are often fairly large scale operations undertaken by local authorities. However, at the individual householder level, large volumes of wastewater are available for reuse for purposes such as garden watering, ornamental uses in fountains and waterfalls, landscaping and lawn irrigation.

2. SOURCES OF WATER IN QUEENSLAND

Queensland currently relies on both surface and groundwater to meet the needs of its population and industry. At the moment, about 44 per cent of the State’s water needs are sourced from groundwater aquifers, with the balance sourced from surface supplies. During the last 25 years annual water usage throughout the State has almost doubled from about 1 700 000 megalitres per year in 1970 to around 3 300 000 megalitres in 1995. 13 The Queensland Government has been responsible for the construction of 28 dams, 91 weirs and 22 groundwater recharge weirs throughout Queensland to supply water for urban use, industry, irrigation and electric power generation.

10 J Denlay and B Dowsett, Water Reuse the most reliable water supply available, a report prepared as part of the Sydney Water Project, Friends of the Earth Inc, Sydney, November 1994, p 6. 11 Denlay & Dowsett, p 6. 12 Simpson, 1993, p 1 as quoted in Denlay & Dowsett, p 6. 13 Queensland. Water Infrastructure Task Force, Report to the Minister for Natural Resources, 28 February 1997, pp 8-9. Page 4 Every Drop is Precious: Greywater As An Alternative Resource

About 94% of the State’s urban population is provided with water supplied by Water Boards and Local Government. Most urban water supply infrastructure has been funded by local ratepayers and State Government contributions towards headworks.14

Urban water services are provided by the South East Queensland, Mount Isa, Townsville/Thuringowa and Gladstone area water boards, two joint local government water boards, 125 local governments and some private suppliers. The State Government is not directly responsible for the provision of urban water supplies. 15

3. USE OF WATER IN AUSTRALIA AND QUEENSLAND

3.1 AUSTRALIA

Australia’s domestic water use has increased significantly over the past 40 years as a consequence of increasing population and rising per capita use.16 The actual level of usage varies greatly between areas depending on the local rainfall, number of rainy days, mean temperatures and humidity, availability of water, pricing and education. Statistics published in 1994 revealed that annual average consumption figures for households ranged between 263 kL per year in Sydney to 700 kL per year for Darwin. Average usage in Brisbane was 430 kL annually. 17

Statistics published in 1997 show consumption at much higher levels. Throughout Australia, it varied between 390 and 1450 L per person daily. 18 Historical data on water use reveals that during the last couple of generations we have doubled our daily per capita use from 250 L in the 1920s to 500 L in recent times. 19

In most Australian households, water is mainly used outdoors, with some 30-75 per cent spent watering lawns and gardens. Toilets, showers and laundries each account

14 Water Infrastructure Task Force, p 9. 15 Queensland. Department of Natural Resources, Water Infrastructure Planning and Development 1997-98 to 2001-02 , Queensland Government, Brisbane, July 1997, p 2.1. 16 Australia. Department of Environment, Sport and Territories, Australia: State of the Environment 1996, CSIRO Publishing, Collingwood, 1996, p 7-11. 17 ARMCANZ, 1994, Pricing systems for major water authorities in Australia, Agriculture and Resource Management Council of Australia and New Zealand Paper, FCMC, No. 2 as quoted in Department of Environment, Sport and Territories, p 7-12. 18 J Crockett and L Carroll, “Water: Consume Less and Pay More”, AWWA 17th Federal Convention, World Congress Centre, Melbourne, 16-21 March 1997, Australian Water & Wastewater Association, Artarmon, Volume 2, p 91. 19 Crockett & Carroll, p 91. Every Drop is Precious: Greywater As An Alternative Resource Page 5 for between 15 and 20 per cent of total domestic water use. 20 The requirement for drinkable water in the kitchen is small - between four and ten percent of the total. These figures represent the average for urban households with secure reticulated water supplies. Country areas with a less secure or no reticulated supply may well have significantly different patterns of domestic water consumption.

A comfortable consumption of water needed per day is calculated to be 125 L, while the minimum could be as low as 60 L per person per day. 21 In light of the fact we are using up to 1450 L per person a day in 199722, these figures highlight the current excessive use of water within Australia.

Using water wisely enables us to save a precious resource, and save money and energy. If Australians reduced their water usage by 15 percent, $240 million could be saved annually in water production costs, and capital expenditure on new dams, treatment plants, pumps, pipes and reservoirs could be delayed.23 In addition, the natural environment would be conserved as we would be pumping less water out of the ecosystem, hence placing less stresses on that environment.

Most of Australia’s population lives along the east coast. This means that historically many communities have discharged their wastewaters into the water bodies such as the ocean. This practice is being increasingly criticised. Despite parts of the community showing a desire to reuse treated effluent, efforts are being frustrated because of a low demand for such water where fresh water supplies are plentiful.

3.2 QUEENSLAND

The Queensland Department of Natural Resources is the single largest water services provider, with assets of approximately $2.5 billion. The Queensland rural sector accounts for approximately 75 per cent of total water consumption. The urban water sector accounts for approximately 20 per cent of total water consumption. Urban water assets are estimated to be worth $18.5 billion which are owned mainly by Queensland’s local authorities or water boards. 24

20 Crockett & Carroll, p 91; and Waterwise Queensland, Waterwise in the Home, Department of Natural Resources, Fact Sheet 2. 21 Crockett & Carroll, p 91. 22 Crockett & Carroll, p 91. 23 Waterwise Queensland, Be Waterwise at Home: If water came in buckets, how many would you use each day?, Department of Natural Resources. 24 Department of Natural Resources, Water Infrastructure Planning and Development 1997-98 to 2001-02 Implementation Plan, p 2.1. Page 6 Every Drop is Precious: Greywater As An Alternative Resource

Industry and commerce consume about 20 per cent of Queensland’s water supply, fire fighting and leaks account for 16 per cent, while domestic use accounts for the remaining 64 per cent. Water consumption levels vary between households and individuals across the State. Actual usage can vary between 1500 and 5000 L per household each day.25 The current average water consumption in Queensland is calculated at 1965 L per household per day. This includes domestic, industrial and other water use. This is equivalent to 635 L per person daily. As with the Australian data, water consumption per capita is also increasing in Queensland. In 1987, the average water consumption was only 590 L per person daily.26

The following is an estimate of average water use in Queensland:27

Water Use in Queensland Inside (domestic) Toilet (full flush) 12 litres Bath 50-150 litres Shower 40-250 litres Dishwasher 20-50 litres Washing machine 40-170 litres Tap running while brushing teeth 5 litres Shaving 8 litres Drinking, cooking, cleaning 8 litres Queensland’s daily inside (domestic) average per person 205 litres Outside (domestic) Garden sprinkler up to 1000 litres Car washing with hose 100-300 litres Hosing driveway 50-100 litres Dripping tap (all day) 30-200 litres Queensland’s daily domestic (outside) average per person 205 litres Industrial/ commercial per person 125 litres Fire fighting, leakage and community use per person 100 litres Total Daily Average per person 635 litres

25 Waterwise Queensland, Waterwise in the Home. 26 Waterwise Queensland, Waterwise in the Home. 27 Waterwise Queensland, Waterwise in the Home. Every Drop is Precious: Greywater As An Alternative Resource Page 7

As mentioned earlier, once this water is consumed or “used”, it becomes effluent. A survey undertaken in 1993 of sewage effluent production and disposal in Queensland revealed that we produce 305 000 ML of effluent each year. Of this, 70 per cent comes from the south-east corner of the state.28 About 88 per cent of the state’s total effluent production is discharged into inland waterways which may then be subsequently used for irrigation purposes. Another 10 per cent is disposed of by applying effluent to land such as golf courses, parks, forestry areas and farms.

However, water is not utilised in an efficient fashion. Industrial enterprises use high quality drinking water for various industrial purposes, for example cooling. Every day, people use the same high quality water to wash the family car.

3.3 HOW MUCH WASTEWATER DOES QUEENSLAND PRODUCE EACH DAY?

Less than 0.5% of domestic sewage is solid waste, the majority is used water.29 Obviously then, large volumes of wastewater are generated and wasted each day. An average three bedroom household generates 580 litres of wastewater daily. The actual quantities of wastewater produced depends on the number of occupants and their water-use practices.30 On average, 180 litres per day of wastewater is generated from the toilet, accounting for 31 percent of the total generated. The bathroom and laundry produce 220 L/day (38%) and 140 L/day (24%) respectively. The kitchen produces only 7%, or 40 L/day, of the total wastewater generated.

4. WHAT IS GREYWATER?

Domestic wastewater or sewage can be divided into two flows. Firstly, blackwater which is sourced from toilets and kitchens and has gross faecal coliform contamination31 and generally has high concentrations of organic matter. Secondly,

28 T Gardner, A Bryan, X Hu, I Gordon and P Beavers, “Land Disposal of Sewage Effluent in Queensland: A survey of current practice and future opportunities”, Effluent Treatment: Disposal and Reuse, Seminar Notes, Queensland Department of Environment and Heritage and the Department of Primary Industries, 17-19 May 1995, p 6. 29 M Compagnoni, “Creative ways with sewage”, Australasian Science, vol 19, no 1, February 1998, pp 22-24; p 24. 30 Queensland. Department of Primary Industries, Policy Options Paper: The Use of Greywater, Rural and Resource Development Group, Brisbane, January 1996, pp 5-6. 31 Faecal coliforms are thermotolerant coliform organisms mainly indicating faecal contamination and the possible presence of intestinal pathogens such as Salmonella and enteric viruses. Escherichia coli (E. coli) is generally the dominant species. Page 8 Every Drop is Precious: Greywater As An Alternative Resource greywater which comes from the bathroom and laundry and is the largest flow of wastewater.

The term greywater refers to untreated household wastewater which has not been contaminated by toilet waste. It includes water from bathtubs, showers, hand basins, laundry tubs, floor wastes and washing machines. It doesn’t include waste from the kitchen sink, garbage disposal units or dishwashers.

It is called greywater because if stored for even short periods of time, the water will often cloud turning a grey colour. Greywater is sometimes termed sullage in Australian literature. The exact sources of greywater vary between organisations, as well as Australian and international jurisdictions. Some definitions include the water sourced from the kitchen and dishwater.

For this Bulletin, “greywater” will not include water sourced from the toilet or the kitchen.

In most literature, blackwater and greywater water are lumped together to be called wastewater. Wastewater is defined as: The used water from the community containing dissolved and suspended matter.32

Therefore wastewater can be sourced from agriculture, industry and residential homes. This label, although convenient, is misleading as the term implies the water is a “waste” requiring disposal.

The difference between the terms “wastewater” and “effluent” are ill-defined and confused in the literature. For this Bulletin, the terms are defined similarly.33

Both greywater and blackwater can be reused after different levels and methods of treatment. Greywater is easier, more convenient, safer and faster to reuse than blackwater and is the focus of this paper.

4.1 WHY USE GREYWATER?

Much of the wastewater generated and wasted each day is greywater. The total volume of greywater potentially available each day from the average Queensland household is 356 L, representing 60 per cent of the total wastewater generated.34 The exact amount of greywater produced in households depends on the number of

32 Queensland. Department of Primary Industries, The Use of Greywater, p glossary. 33 Refer to the Glossary included in this Bulletin. 34 P Beavers, "Greywater: An alternative water source?", Effluent Reuse and Alternative Treatment Seminar, Townsville, 17-19 May 1995, p 1. Every Drop is Precious: Greywater As An Alternative Resource Page 9 residents and their water use practices. Toilet flushing makes up less than 20 per cent of domestic sewage, the majority comes from showers and washing machines.35

Greywater can be reused throughout Queensland communities for purposes such as garden watering, ornamental uses in fountains and waterfalls, landscaping and lawn irrigation. In the drier parts of the state, all household irrigation could be met with greywater generated from within the household.36

Greywater reuse utilises an on-site resource which is otherwise wasted. As a result of reuse, fresh water drinking supplies are conserved enabling it to remain in natural ecosystems. Greywater has the potential to save on average 50 per cent of an average household’s water use.37

Apart from savings to the consumer, greywater reuse saves a water authority money, reduces sewage flows and reduces the demand on potable water supplies when combined with sensible garden design.38 About 84 per cent of the Australian community is connected to sewerage.39 The sewerage systems in most of Australia’s major cities are old and in many areas overloaded.40 This problem is only going to become worse as our population grows. Alternative options to the traditional system, such as reuse of greywater, need to be investigated. The load on wastewater disposal systems is reduced and therefore their life is prolonged and capital expenditure required for upgrading and expansion is delayed, if not potentially abated.

4.2 GOVERNMENT RESPONSES TO WATER CONSERVATION AND REUSE

The need to thoroughly investigate reuse technologies was recognised officially as far back as 1983 when the federal Department of Resources and Energy initiated a

35 Compagnoni, p 24. 36 Beavers, p 1. 37 Australian Water and Wastewater Association, AWWA Queensland Branch Policies, AWWA, Brisbane, April 1997, p 20. 38 Water Authority of Western Australia, What is wastewater?, Wastewater 2040, Perth, 1993 as quoted in M Anda, G Ho and K Mathew, “Greywater Reuse: Some Options for Western Australia”, Designing for a Sustainable Future, Proceedings of the Sixth International Permaculture Conference & Convergence, Perth and Bridgetown, 27 September to 7 October 1996, Permaculture Association of Western Australia, 1997. Available at Internet location: http://www.cowan.edu.au/~paustin/ipc6/ch08/marshall/index.htm 39 C Davis, “Wastewater Treatment in Australia”, Waste Management and Environment, 4 (10), 1 September 1993, pp 26-30, 33-34, 36-37; p 26. 40 Davis, p 36. Page 10 Every Drop is Precious: Greywater As An Alternative Resource study into water reuse.41 This study was undertaken as part of a project known as Water 2000 which presented potential water demands and supplies in Australia up to the year 2000. It focussed on municipal, agricultural and industrial reuse opportunities but, unfortunately, spent very little effort on analysing domestic reuse options.

There have been several Federal Government inquiries which have recommended the conservation of potable water supplies. For example, in 1993 the Senate’s Standing Committee on Environment, Recreation and Arts Report on Water Resources - Toxic Algae recommended greywater be considered as an alternative water source in the development of housing estates.42

At the state level, several New South Wales studies on greywater reuse have resulted in the installation of a dual reticulation system43 at the Rouse Hill Development, north west of Sydney. In Queensland, under the State Water Conservation Strategy, one of the strategies being pursued is the investigation of alternative sources of water. In addition, within Queensland, a public education campaign known as Waterwise was launched in April 1992. 44 The objective of the currently on-going campaign is to reduce household water consumption in urban centres by up to 20 percent. A reduction in water use of that order in Queensland would correlate to a saving of up to $40 million annually for all Queenslanders. Another $40 million is potentially able to be saved because of the deferment of costs associated with capital works. There are also the unmeasured environmental benefits that would accrue from reduced water use.45

In other states and overseas it has been demonstrated that a reduction in water consumption will result in significant financial returns. In Victoria, water conservation measures have resulted in a present day saving of approximately $75 million on capital works for Melbourne alone.46

41 Gutteridge, Haskins and Davey, Department of Resources and Energy, Water Technology, Reuse and Efficiency, Water 2000: Consultants Report No 10, AGPS: Canberra, 1983. 42 Australia. Senate Standing Committee on Environment, Recreation and the Arts, Water Resources - Toxic Algae, Australian Parliamentary Papers No 387 of 1993, AGPS: Canberra, December 1993, p 18. 43 A dual reticulation system is one where the property has access to the normal potable water supply but also access to wastewater that has been sufficiently treated for its intended purpose, which may be irrigation. 44 For a more thorough discussion of the campaign see: K Jones, T Lewis and K Aitken, “Waterwise Queensland - the joint venture”, Water, 20 (3), June 1993, pp 12-15. 45 K Jones, T Lewis and K Aitken, “Waterwise Queensland The Joint Venture”, Water - Every Drop is Precious, the 15th Federal Convention of the Australian Water and Wastewater Association, Hotel Conrad, Gold Coast, 18-23 April 1993, Volume 1, p 269. 46 Jones, Lewis & Aitken, Water - Every Drop is Precious, p 274. Every Drop is Precious: Greywater As An Alternative Resource Page 11

Wastewater recycling, particularly reuse of greywater within the home, became topical in Queensland in September 1994 when the majority of the state’s 196 sewage treatment plants were found to be unable to meet their licence requirements and needed $82.5 million dollars worth of upgrading.47 The plants failed to meet their licensing conditions as a result of a lack of regular monitoring programmes or because the quality or quantity of sewage output was considered inadequate. The identification of such a major problem with our current disposal system emphasised the need to further investigate other options, such as wastewater reuse.

4.3 WASTEWATER REUSE OPTIONS

People commonly say we “use” water, however it is more accurate to say we dirty it. Once used, this water then becomes sewage, which is made up mostly of wastewater and solids. In many respects, the term wastewater is a misnomer. It implies it is something inherently wasteful rather than a potentially valuable resource as it is increasingly being viewed.

Once water is “used”, the traditional response was to dispose of the sewage to a sewage treatment plant. From here, the wastewater is most often disposed into waterways or the ocean. However, the technology exists allowing for the reuse of wastewater.

Wastewater reuse options available include:

· Treatment - sending wastewater to a water reclamation plant where it can be treated. This treated water can then be returned to the water supply. If the treated water is returned to a body of water such as dams and rivers, it is known as indirect potable reuse. This type of reuse situation occurs fairly often in Australia.48 The other option is direct potable reuse where wastewater is treated to sufficiently high standards enabling it to be returned directly to the water supply via the normal pipes delivering our drinking water. There are no examples of direct potable reuse currently occurring in Australia;49

47 M Hele, “Sewage plants fail test - 196 exposed in crackdown”, Courier Mail, 2 September 1994, p 16. 48 By next year, the Caboolture Shire Council intends to pump wastewater from the sewage plant to a water treatment plant. At this plant, the water will undergo five systems of treatment and filtration. The end product of this system will then pumped into the local weir. It is from this weir that water will be drawn for the normal water treatment plant and home supply system. Therefore, indirectly people will be drinking recycled water. It is predicted that residents and visitors to the Gold Coast will be drinking and bathing in recycled water within 20 years. See: D Petersen, “Turning sewage into fresh water”, Courier Mail, 29 April 1996, p 7; P Bartsch, “Coast plan to recycle its sewage”, Courier Mail, 27 April 1996, p 19. 49 There are currently studies being undertaken in various parts of the country into potable or drinkable reuse of wastewater, but there is little support for these schemes. Only a couple of Page 12 Every Drop is Precious: Greywater As An Alternative Resource

· Dual reticulation systems - This is where effluent is treated and returned to the home for limited uses such as garden watering or toilet flushing. This system requires the installation of two water delivery systems, one containing normal potable water and the other containing the reclaimed water. Systems such as this have been established for trial at Rouse Hill in Sydney’s outer suburbs.

These reuse options involve the application of technologies on a large scale. Relevant authorities have to be involved in constructing, designing and legislating for the application of such systems. An individual does not have the power to influence these decisions, and thus reduce their water consumption. At the householder level, greywater reuse allows individuals to have control over their water usage patterns.

4.4 ACCESSING GREYWATER

Many slab based homes have plumbing pipes encased in concrete. Unfortunately, it has been accepted in the past that blackwater and greywater converge within these pipes before it leaves the slab. This makes gaining access to greywater exceedingly difficult and costly in these properties. Non-slab houses can generally be easily replumbed allowing access to greywater. Obviously greywater systems could be incorporated into new housing developments with little additional cost.

4.5 GREYWATER QUALITY

Greywater contains what is washed down the drain, so it will vary between households and even vary daily depending on the activities of the occupants of the household. For most households it contains soap, shampoo, toothpaste, shaving cream, laundry detergents, hair, lint, body oils, dirt, grease, fats and chemicals from soaps, toothpaste, shampoos, cosmetics and urine50. The most significant pollutant of greywater is laundry detergents, particularly those high in salts (sodium) and phosphorous. Greywater also contains bacteria, parasites and viruses washed from the body and clothes. Baths and showers generate the greatest volume of greywater, but also contribute the greatest micro-organism load.

years ago there was a serious investigation into the application of such technology at Noosa. Widespread community concern with the scheme, as well as a change in political support, meant the scheme was dropped. See M Macdermott, ‘Plan for potable sewage water’, Australian Environment Review, vol 10, no 2, February 1995, p 12. This Bulletin will not deal with the reuse of wastewater for potable means. 50 Concern is often expressed regarding people urinating in baths and showers. Urine is generally considered a sterile solution and therefore, if it enters the greywater will not contribute to health problems, only increase the nutrient load, which could be beneficial to plants if used appropriately. Every Drop is Precious: Greywater As An Alternative Resource Page 13

Studies have shown that of the total household wastewater load, greywater is likely to contain51:

63% of the BOD52 load;

39% of the suspended solids load;

18% of the nitrogen;

70% of the phosphorous;

65% of the wastewater flow.

The above figures highlight the fact that greywater is contaminated with potential pollutants. However, on average greywater contamination is quite low.53

4.5.1 Microbial

The microbial quality of greywater is measured by the presence of faecal coliforms, such as Escherichia coli, or E. Coli as it is more commonly known, which indicate the presence of intestinal pathogens such as Salmonella or enteric viruses. The quantity of faecal coliforms is used as a pollution indicator and hence the safety of greywater. Generally a high faecal coliform count is undesirable and implies a greater chance for human illness to develop as a result of contact during greywater reuse. It must be remembered that the faecal coliform count is only a pollution indicator. Even if the count is low the greywater may still contain other harmful micro-organisms. These include other bacteria, viruses, protozoa and helminths (parasitic worms).

Few studies have specifically addressed the microbial count of greywater. In one such study undertaken54, the faecal coliform count in shower water was 6000 colony forming units (cfu) per 100 ml. In laundry water and its rinse water, 126 and 25 cfu per 100 ml were reported. In a more recent study55, bathroom greywater was found

51 R L Siegrist, “Waste segregation as a means of enhancing on-site wastewater management”, Journal of Environmental Health, vol 40, no 1, July/ August 1977, pp 5-9 as quoted in Beavers, 1995, pp 3-4. 52 BOD is a measure of the biological consumption of oxygen in water, especially as a result of the breakdown of organic matter by microorganisms. 53 Beavers, p 4. 54 J B Rose, Gerba Gwo-Shing Sun and N A Sinclair, “Microbial quality and persistence of enteric pathogens in greywater from various household sources”, Water Research, vol. 25, no. 1, 1991, pp 37-42 as quoted in Beavers, 1995, p 4. 55 P Lechte, R Shipto and D Chrisstiva-Baal, 1994, “Installation and Evaluation of Domestic Greywater Reuse Systems in Melbourne, Proceedings of the AWWA 16th Federal Convention, Sydney 1995, as quoted in Beavers, 1995, p 4. Page 14 Every Drop is Precious: Greywater As An Alternative Resource to contain between 170 and 3300 most probable number (MPN) faecal coliforms, while laundry greywater contained between 110 and 1090 MPN faecal coliforms. These levels are well above accepted safety levels. So whilst the data is limited, it does demonstrate that greywater could potentially pose a health risk if it came into contact with humans.56

4.5.2 Chemical

Greywater contains significant loads of nutrients, particularly nitrogen and phosphorous. This has the potential to cause toxic algal blooms. An average greywater volume of 356 litres per day will produce approximately 45 grams per day of nitrogen and 3 grams per day of phosphorous.57 Managed properly these nutrients could be beneficial to the home owner, reducing the amount of commercial fertiliser applied to gardens and lawns. If inappropriately used, these nutrients could add to the nutrient load in natural waterways resulting in environmental damage.

Limited evidence from trials and existing greywater systems suggest that there are no adverse effects on lawns and ornamental gardens from chemicals occurring in greywater. However concerns are raised that chemicals in greywater could cause damage to clay soils and some native plants and increase the level of nutrients in groundwater and waterways.58

4.6 METHODS OF GREYWATER REUSE

For the safe reuse of greywater, either it must be treated to destroy microorganisms or human contact with greywater must be prevented. Treatment of greywater making it safe for human contact is expensive to achieve on an individual household basis.59 It is also difficult to ensure the treatment system is maintained. Therefore, the safest method of greywater reuse is one that excludes human contact.60 The 22

56 Obviously if greywater used for the washing of baby nappies was included, the coliform count could be greatly increased. Many studies recommend not reusing water used for the rinsing or washing of nappies because of the high faecal coliform load and potential for disease.56 Washing domestic pets in the laundry or bathroom is also not recommended because of the obvious increase in pathogens present in greywater, as well as introducing higher loads of hair into the greywater system. 57 Beavers, p 4. 58 B Jeppesen, and D Solley, Domestic Greywater Reuse: Overseas Practice and its Applicability to Australia, Urban Water Research Association of Australia, Research Report No 73, March 1994, p (i). 59 B Jeppesen, Model Guidelines for Domestic Greywater Reuse for Australia, Urban Water Research Association of Australia Research Report No 107, March 1996, p ii. 60 Jeppesen, Model Guidelines for Domestic Greywater Reuse for Australia, p ii. Every Drop is Precious: Greywater As An Alternative Resource Page 15 western states of the USA have adopted this principle as part of their uniform plumbing code that allows domestic greywater reuse.

For lawn and garden watering, separation of greywater from human contact can be achieved by:

· sub-surface irrigation - greywater does not reach the ground surface; or

· surface irrigation - irrigation confined to a non-habitable dedicated area where it cannot form aerosols or surface run-off.

Sub-surface irrigation is the preferred option because it is the safest and most efficient method of greywater use.61 If the greywater is applied within the top 30 cm of the soil, pathogens are unlikely to survive due to the high microbial activity in this soil zone. Irrigation is more efficient at the sub-surface than surface level because most plants take up water and nutrients from their root zone and the potential for evaporation and run-off are reduced. Surface irrigation promotes ponding which can be an ideal habitat for the breeding of mosquitoes. Also, run-off may occur after heavy rain or excessive irrigation with surface disposal methods.

4.6.1 Types of greywater systems

There are a number of different types of greywater systems available to the community. They range in complexity from bucketing water to automatic systems which include various treatment options. The choice of system will vary for the home owner depending on the commitment to the system, cost, lifestyle, climate and site. The systems can be quite simple, low-cost systems or highly complex and hence costly commercial systems. Accordingly, official acceptance varies. Many books comprehensively discuss the specifics of the various available systems. Refer to these for more information.62

Basic parameters which should be incorporated into any greywater system are as follows: · avoid the storage of greywater to limit the creation of increased pathogen numbers and unpleasant odours; · application of the greywater should be sub-surface under mulch, soil or gravel rather than at the surface. This will limit potential human contact with greywater which is a possible method of disease transmission;

61 Jeppesen, Model Guidelines for Domestic Greywater Reuse for Australia, p iii. 62 See:A Ludwig, Create and Oasis with Greywater, Oasis Design, Santa Barbara, Revised 2nd edition, 1997: and A Ludwig, Building Professional’s Greywater Guide: The guide to professional installation of greywater systems, Oasis Design, Santa Barbara, 1995. Page 16 Every Drop is Precious: Greywater As An Alternative Resource

· the installation of a three way valve which would allow for the diversion of certain water loads away from the greywater system if unwanted chemicals have been used or nappies washed; · avoiding the use of greywater on any garden produce.

5. ADVANTAGES AND DISADVANTAGES OF GREYWATER REUSE

The advantages and disadvantages of greywater reuse can be broadly grouped into three areas. These are: · public health issues; · environmental considerations; and · costs associated with installing and maintaining a greywater system.

5.1 SEWAGE = POLLUTION = PUBLIC HEALTH DANGER

The large increase in life expectancy from about 30 years of age to over 50 years of age which occurred in the latter part of the 19th Century was directly attributed to the establishment of a reticulated potable water supply which was separated from sewage treatment and disposal. That is, the creation of the current system we all now know and expect.63 In the intervening 100 years or so, few changes have occurred in the general way our water was supplied and delivered.

Beavers warns:64 We live in a society that has a relatively low incidence of water borne disease outbreaks. The sanitary sewer can be partly credited for this status. Infectious disease epidemics occur once the disease is introduced to the population and has a mode of transmission. Any decision to change the present sanitary practices should not be taken lightly.

5.1.1 Public health

Human health concerns are pivotal in the evaluation of greywater reuse. Pathogens or micro-organisms in greywater may create unacceptable public health risks. The method of disposal of greywater may contribute to health risks. As discussed in section 4.5 on greywater quality, there is the potential for greywater to contain significant levels of pathogens. The health risks associated with greywater reuse

63 Gardner, Bryan, Hu, Gordon & Beavers, p 1. 64 Beavers, p 7. Every Drop is Precious: Greywater As An Alternative Resource Page 17 generally relate to acute effects associated with infection from pathogens such as bacteria, protozoa, including Cryptoporidium,65 viruses and parasites. No studies to date have identified long-term or chronic impacts associated with the reuse of reclaimed water.66

Illnesses due to contact with greywater reuse have not been reported, despite widespread reuse of greywater.67 This does not necessarily mean that no illness has actually occurred, and does not discount the possibility of disease transmission. While there have been no documented disease outbreaks resulting from the reuse of greywater in Australia, the consequences associated with the reuse of raw or improperly treated wastewater in other countries is well documented.

Surface spray disposal of greywater produces aerosols or droplets that cannot be confined to a dedicated area. This poses a potential health risk. Therefore, to minimise the environmental and health risks associated with greywater use, sub- surface irrigation is recommended.

5.1.2 Mosquitoes and vermin

Poor irrigation and storage practices with the use of greywater may result in the breeding of pathogens, mosquitoes and vermin. Rats, mice, cockroaches and flies could all use inadequately maintained greywater reuse systems to breed. Apart from the problems they directly cause, they can also transmit pathogens.

Common mosquitoes throughout Queensland prefer breeding in water containing a high level of organic pollutants, such as greywater may contain. Mosquito born diseases such as Dengue fever and Ross River fever are already prevalent in Queensland. The provision of additional locations for breeding could worsen the incidence of such diseases. However, this would only be likely with poor practices. Community education and inspections could reduce this potential hazard.

5.1.3 Multiple Users

The health risks associated with greywater reuse in multiple occupancy dwelling is increased because no-one claims responsibility for the system. There is a preference

65 Recently there has been a public outbreak of this parasite in south-east Queensland pools. See: E Riggert, “Pools to stay open despite discovery of deadly bug”, Courier Mail, 13 March 1998, p 7. 66 I B Law, “Domestic Non-potable Reuse - Why even consider it”, AWWA 17th Federal Convention, World Congress Centre, Melbourne, 16-21 March 1997, Australian Water & Wastewater Association, Artarmon, Volume 2, pp 135-142; p 137. 67 Jeppesen & Solley, p 32. Page 18 Every Drop is Precious: Greywater As An Alternative Resource by greywater users to only use greywater from their own household rather than from a group of households. This can be beneficial because it reduces the potential for the spread of disease forming organisms within a neighbourhood.68 For just this reason, the Californian plumbing code restricts greywater reuse to within a single family dwelling.69

5.1.4 The reliability of owner maintained systems

The success of greywater reuse systems depends on an individual’s efforts in maintaining the system. Individuals may not remain committed to the system. Surveys in the USA, Australia and Brisbane have found that 60 to 80 percent of the on-site domestic wastewater treatment plants are not adequately maintained.70 This means the systems do not meet their effluent quality requirements.

Greywater reuse although recognised as being potentially environmentally friendly is considered by many officials not to be hygienic even with householder commitment. It is often suggested that greywater reuse systems be limited to larger blocks than those generally available in urban areas.

5.1.5 Reduced flows to the sewerage system

The reuse of greywater may reduce the flow of sewage into sewerage systems. This may affect the transportation of solid matter creating blockages. New systems of sewage transport may need to be constructed if there was widespread acceptance of greywater reuse. A 1994 Friends of the Earth Report recommended the promotion of on-site treatment systems such as septic systems or aerobic treatment systems because their use reduces wastewater flows into centralised systems.71 In fact, the Report further recommended that such systems be actively promoted through the provision of incentives, such as rebates and low interest loans. In non-sewered areas, greywater reuse systems are already a proven method of greywater use.72 Currently the emphasis is on greywater disposal rather than use. However, options exist for the more efficient use of this resource. Initial studies indicate greywater reuse would

68 Beavers, p 6. 69 Ludwig, Building Professional’s Greywater Guide: The guide to professional installation of greywater systems, p ii. 70 Jeppesen & Solley, p (i). 71 Denlay & Dowsett, p 8. 72 B Jeppesen and D Solley, Domestic Greywater Reuse: Overseas Practice and its Applicability to Australia, Urban Water Research Association of Australia Research Report No 73, March 1994, p 87. Every Drop is Precious: Greywater As An Alternative Resource Page 19 allow most households to meet all toilet flushing requirements as well as a significant portion of outdoor water usage such as watering lawns and gardens.

Wastewater treatment plants in domestic homes work best under a continuous and even flow rate. In normal households this is unlikely to occur. For example, all of the washing would tend to occur at one time. Meal preparation and bathing may also occur in clusters rather than evenly spread throughout 24 hours. These peaks and troughs in flow rate affect the treated effluent quality.

5.1.6 Concerns with greywater use for toilet flushing

Water is required to transport wastes in a flushing toilet. There is no logical reason that this water be of the high standard required for potable use. Therefore greywater could be used in this system provided the health risks were found to be negligible. An alternative system available in Japan involves a toilet suite that incorporates a basin and fountain for hand washing on top of the cistern. The fountain is the cistern’s water supply pipe. After the toilet is flushed, hand washing can occur for the period of refilling. This is a more direct greywater reuse system.

A 1993 report claimed the recycling of greywater for toilet flushing appeared to present no appreciable risk to public health.73 Potential water savings were said to be in the order of 31.8% of total in-house use every day. However, a later report refuted the safety claim for toilet flushing.74 Subsequently, the practice of reusing greywater for toilet flushing has not been recommended.

5.1.7 Flexibility of water use

Greywater reuse systems give home owners more flexibility in their use of water. For example, longer showers may not cost the owner any more because the additional greywater would be used on the garden, reducing the amount of potable water normally used for irrigation. An additional benefit of greywater reuse is that home owners can water their gardens during sprinkler restrictions because they are reusing water.

73 B Jeppesen, Domestic Greywater Reuse: Preliminary Evaluation, Urban Water Research Association of Australia Research Report No 60, July 1993, p 39. 74 Jeppesen & Solley, p ii. Page 20 Every Drop is Precious: Greywater As An Alternative Resource

5.1.8 Summary

In a research paper on greywater reuse produced for the Brisbane City Council in 1994, possible risks to public health from greywater systems were discussed.75 Many of the problems identified were similar to those mentioned in this section such as providing habitats for mosquito and vermin, the presence of pathogens, and the maintenance of systems. As a result of minimal supporting information being provided for these claims, the Friends of the Earth described them as “yet another report by water professionals reacting against the possibility of a less centralised water management system”.76 The Friends of the Earth report was highly critical of the motives of many of the people associated with the water industry, particularly those dealing with the health aspects of greywater reuse. Virtually all health departments are united in their bitter opposition to greywater reuse, yet there has still not been one documented instance of illness caused by greywater in the United States.77

Research into the public health hazards of greywater use is very limited. Of the research currently undertaken, no data exists which indicates the presence of problems which can not be controlled or eliminated using current technology and practices.

5.2 ENVIRONMENTAL CONSIDERATIONS

The community’s expectations associated with the environmentally acceptable disposal of sewage have dramatically changed in recent times. This change has resulted from a combination of issues. These include changing attitudes towards the environment, improved scientific assessment of waterways and oceans, governments adopting ecologically sustainable policies, highly publicised examples of poorly performing sewage ocean outfalls, for example Bondi Beach, and environmental disasters such as the world’s largest recorded outbreak of toxic cyanobacteria, more commonly known as blue-green algae, which occurred in over 1000 km of the Murray-Darling river system during the summer of 1991-1992. Similar outbreaks of blue green algae have occurred in Queensland reservoirs which are used for urban water supplies. The prevention of these problems through appropriate water conservation measures is one solution currently available.

75 B Jeppesen, Greywater Re-Use”, in Recycles Water Seminar 19-20 May 1994, Newcastle City Hall Proceedings, AWWA NSW Branch: Newcastle, pp 197-204. 76 Denlay & Dowsett, p 8. 77 Ludwig, Building Professional’s Greywater Guide: The guide to professional installation of greywater systems, p ii. Every Drop is Precious: Greywater As An Alternative Resource Page 21

5.2.1 Water Conservation

The most obvious benefit from greywater reuse is water conservation. Different studies have identified different levels of potential water conservation resulting from the use of greywater systems. In 1994, Jeppesen and Solley said: The average Australian home uses in the order of 50% of its total water usage outside the house. By reusing the total volume of greywater produced on lawn and garden watering, the potable water use for the average home can be reduced by 323 litres per day.78

Other studies have identified differing amounts of potential savings. (See Section 4.1). Differences occur because of the water consumption habits of the individual members of each household. Regardless of the exact amounts of potable water able to be saved with greywater reuse systems, all of the studies agree that potentially the savings are significant.

5.2.2 Effects of applying greywater to the soil

Greywater may be beneficial for plants because it contains nutrients such as nitrogen and phosphorous. However it may also contain sodium and chloride which can be harmful to some plant species. A residential non-potable reuse project of 18 months duration was commenced at Shoalhaven, NSW in 1989. Whilst no adverse health effects were observed, the study found there was an increase in soil nutrients and sodium level.79 The environmental concerns associated with the irrigation of greywater on soil structure and groundwater quality need to be more thoroughly assessed.80

Irrigation water quality and nutrient load should be monitored and only applied at a rate required to meet the demand of the vegetation. Applications beyond this rate pose the threat of surface run-off or contamination of groundwater.

5.2.3 Contamination of the water table

The reuse of greywater within a domestic dwelling could potentially reduce the amount of nutrients in wastewater, such as nitrogen and phosphorous, being discharged in water bodies such as rivers, streams and the ocean. They could be

78 Jeppesen, Domestic Greywater Reuse: Preliminary Evaluation, p 39. 79 JM Anderson, ‘Water conservation and Recycling in Australia: Scenarios for Sustainable Urban Water Use in the 21st Century’, Proceedings of the 16th Federal Convention of the Australian Water & Wastewater Association, Sydney, pp 389-395, cited in Law, AWWA 17th Federal Convention , p 139. 80 Law, p 139. Page 22 Every Drop is Precious: Greywater As An Alternative Resource used beneficially to fertilise the landscape. Problems may arise if greywater leaching allowed nutrients, other chemicals and pathogens to enter the water table.

5.2.4 Aesthetics

Social and environmental factors must be considered with the installation of a greywater system. The environmental problems have been discussed such as public health, nutrification of water supplies, effects on soil structure and flora. Social effects include neighbourhood acceptance. Neighbours may be greatly concerned with the health, environmental and nuisance effects of the system. Untreated greywater does have an unpleasant visual appearance and can emit unpleasant odours. Disposal by sub-surface irrigation would reduce this problem.

5.2.5 Environmental awareness and involvement

The current environmental awareness of the community has given greater emphasis to the on-site treatment and reuse of wastewater. Reuse has considerable appeal over the sanitary sewer. There are already numerous low density residential developments throughout Australia which successfully use on-site disposal or reuse systems for their wastewater. Experimental sites at Rouse Hill in Sydney and several sites in Canberra and Western Australia are examples. Greywater reuse systems encourage home owners to become involved in conservation issues, and hence environmental issues generally.

5.3 CURRENT COST OF WATER AND REUSABLE GREYWATER IN AUSTRALIA

Water use and wastewater disposal costs are not currently a major factor in the cost of living. Based on 1994 figures, all water related charges in a typical city cost between $600-800 per year of the average household income of $43,800 per year, which means water accounts for only 1.4 to 1.8% of average household income. Compared to other household expenditure such as food (10%), videos (0.5%), petrol (3-4%), the family dog (2-3%) or the family car (5-10%), water is relatively cheap. Therefore, the cost of water to the consumer is very low. 81 In addition, the cost to reclaim water is, at the moment, higher than the price we pay for reticulated water.82 However, with the introduction of the user pays principle and full cost recovery pricing schemes, the cost of water to the consumer is expected to rise.

81 Crockett & Carroll, 1997, p 93. 82 J Simpson and P Oliver, Water Quality: From wastewater to drinking water to even better, Australian Water & Wastewater Association, Artarmon, 1996, p 56. Every Drop is Precious: Greywater As An Alternative Resource Page 23

With rising water costs and user pays, all water resources, including greywater, will be valued more highly. This shift in perception will prod more and more home owners and policy makers into viewing greywater as a valuable domestic water resource. Unused greywater will increasingly be seen as money wasted, with its beneficial use promoted as a financial advantage.

At the current cost of providing water, greywater systems offer very little economic advantage to consumers in sewered areas. If the environmental and social costs of using fresh water rather than greywater for suitable purposes were able to be calculated, greywater would become a more attractive option than it currently appears with a purely economic analysis.

5.3.1 Cost of greywater systems

Treatment of domestic greywater is expensive on an individual household basis.83 The average cost of supplying water to Queensland consumers is 46 cents per kL (kilolitre or 1000 litres).84 The Brisbane City Council currently charges 60 cents per kilolitre of water used.85 This is in addition to a $25 service charge per quarter. Based on the replacement of 356 litres per day of potable water with greywater, savings would amount to about $78 annually.86 The cheapest primary greywater system available would involve some sort of storage and gravity fed irrigation system. It could cost as little as $500 with annual maintenance costs of around $5.87 Even with this small initial outlay, the system would have a pay-back period of around 7 years.88 Most simple greywater systems would have a life of around ten years.

If a more expensive system was installed by a plumber possibly involving a pump, the cost could amount to $1500. Based on the above calculations the pay-back period would be 20-21 years, possibly longer than the life of the system installed.89

83 Jeppesen & Solley, p 108. 84 Waterwise Queensland, Waterwise in the Home. 85 Personal communication with Brisbane City Council, 13 February, 1998. 86 This calculation is based on 356 litres daily at a cost of 60 cents per kilolitre (1000 L) for 365 days a year. This amounts to a saving of 21.36 cents daily, and hence $77.964 annually. The cost of the service charge was not included in the calculations because it would be required regardless of the installation of a greywater reuse system. 87 Jeppesen & Solley, p 97. 88 This calculation is based on annual savings of $73 ($78 savings in water cost less the annual $5 maintenance cost). The initial system costs $500. Ignoring the cost of this money, such as interest, the pay-back period is $500/73= 6.85 years. The pay-back period would be greater if interest was charged on the money used to install the system. 89 $1500/73=20.5 years. As with the above calculation, the pay-back period would be greater if interest was charged on the money used to install the system. Page 24 Every Drop is Precious: Greywater As An Alternative Resource

However, these calculations are based on current costs. As mentioned earlier, the cost of water is expected to increase over time, hence reducing the cost return period of these systems. Also, there are reasons other than cost, such as social and environmental issues, for installing these systems. For a full cost analysis, potential savings in the construction of wastewater treatment systems should be included. One study estimates that these savings could be in the order of around $42 million annually to the Brisbane City Council alone.90 The value of nutrients available to plants from the greywater should also be included in a cost-benefit analysis. In addition, the environmental cost of reducing wastes flowing into our waterways and encouraging algal blooms, should be included. However, these items are difficult to cost in monetary terms.

Potentially though, major savings may be made in both potable water supply and sewage system costs with the widespread implementation of domestic grey-water reuse at both the individual household and water authority level. Greywater demand is much higher than the volume of greywater available in most households. Landscape watering typically uses 588 litres per day on average.91 As mentioned earlier, most households will produce around 356 litres of greywater daily. Therefore, all the greywater produced in a household could be used for landscape irrigation. This would amount to a saving of this amount of potable water, reducing its demand by 29 percent.92 This would be a significant saving for householders.

5.3.2 Cost to the community

Greywater use offers a potential financial advantage to regional sewage treatment plants. Their capital and operational expenditure may decrease because the use of greywater will result in a decline in flows to sewers, hence delaying or even potentially abating the need to expand such facilities. A reduced flow to sewers may also have a down side. Some believe flows may be insufficient to carry waste to the treatment plants. Others see this as an unlikely situation in most systems. Officials have also voiced concern that with the increased use of greywater, less effluent will be available for treatment resulting in less reclaimed water for municipal uses, such as watering parks and golf courses. In the bigger picture however, energy and money is required for the treatment and reuse of wastewater. Energy savings would result if water management processes allowed for greywater to be used instead. This is because greywater can be used with less treatment, hence less energy and cost.

90 Jeppesen & Solley, p 102. The magnitude of the potential savings may encourage some local authorities to offer incentives to install greywater systems as happened with their initial introduction in California. 91 Jeppesen & Solley, p 97. 92 Jeppesen & Solley, p 97. Every Drop is Precious: Greywater As An Alternative Resource Page 25

Throughout the State there is a growing recognition that the major factor in achieving acceptable urban water demand management involves a pay-for-use pricing system. Water meter installation programs and pricing structure reform is currently underway in Queensland. At the same time that Local Authorities are moving towards user pays for water, the community as a whole is becoming more environmentally aware to the extent that this concern for the environment can lead to changes in behaviour and changes in attitudes to water conservation.93

Several forces are now shaping the way Australian authorities are dealing with wastewater. The first is a improved awareness of the need for environmental protection than has historically existed. This is coupled with an increasingly rigorous regulatory framework for environmental issues. In addition, constraints on capital spending by water agencies is forcing them to rethink their past practices and therefore investigate new options.

The cost of greywater systems is a significant factor, however it should be noted: Flushing toilets, deep sewerage and wastewater treatment plants did not replace night soil collection for economic reasons but for public health. Similarly, greywater reuse technology may not be viable now in purely economic terms. Its introduction needs to be seen in terms of its contribution to sustainable development and resource conservation without comprising public health or environmental quality.94

6. PUBLIC ACCEPTANCE OF GREYWATER REUSE

For greywater use to be successful, consumers must be willing to use the product. The public must be educated regarding the risks and benefits of greywater use. In much of the literature, the general public’s acceptance of wastewater reuse is identified as a weakness of water reuse technologies. However, most of these studies have only investigated the reuse of wastewater for potable or drinking purposes. Such studies show that only between 19 and 33 percent of the population will accept potable reuse.95 The lower figure arose from studies in New South Wales and Queensland.

Much wider support exists for the reuse of wastewater for purposes other than drinking. Surveys indicate the public’s reluctance to support reuse increases as the

93 Jones, Lewis & Aitken, Water - Every Drop is Precious, p 268. 94 Anda, Ho & Mathew. 95 See the discussion of Lohman 1987 and Hamilton’s 1994 studies as discussed in Denlay & Dowsett, p 57. Page 26 Every Drop is Precious: Greywater As An Alternative Resource degree of human contact with the reclaimed water increases.96 Therefore, the use of reclaimed water for potable or drinking purposes receives the greatest opposition.

A survey in 1987 showed that 100 percent of water professionals approved of reusing water for watering the garden and flushing toilets, the two most commonly promoted reuses of greywater.97 The public showed similarly high levels of acceptance of these activities with 96 percent approving the reuse of water for toilet flushing and 97 percent approving of its use for irrigation. Anecdotal evidence suggests that if home owners perceive a benefit, whether financial, economic or social, from the reuse of greywater, they are prepared to use such systems, even where they are currently illegal. Authorities have found that 20 percent of householders engage in greywater reuse.98 In some cases, it is even more common. A survey undertaken by the Sydney Water Corporation in 1995 found that 41% of respondents were making use of greywater during a drought.99

Investigations in the United States, Japan and Australia have revealed the widespread practice of domestic greywater reuse.100 There is proven experience with the application of greywater systems for lawn irrigation and garden watering and with hand basin toilets.

7. GREYWATER REUSE OVERSEAS

7.1 THE UNITED STATES

The United States of America are leaders in the technology and application of domestic greywater reuse. This may be party due to the fact almost 60% of the homes in the USA are not sewered.101 In addition, some areas of the USA are extremely dry, particularly Southern California, Florida102 and Arizona. These areas have seriously investigated alternative sources of water since 1977 after a severe period of drought required the more economic water usage. Many states now have

96 J Crook, D Okun and A Pincince, Water Reuse, Project 92 - WRE-1, Water Environment Research Foundation: Alexandria, Virginia, 1994, p 7-1. 97 See the discussion of Lohman 1987 in Denlay & Dowsett, p 57. 98 R Lugg, as quoted in Anda, Ho & Mathew. 99 Personal communication with the Australian Water and Wastewater Association as quoted in Ludwig, 1995, p 39. 100 Jeppesen & Solley, p 108. 101 Jeppesen, Recycled Water Seminar, p 4. 102 Florida has set a goal to reuse 40 percent of the state’s wastewater flows. In some areas, authorities are aiming at 100% wastewater reuse by 2010. For a more detailed discussion of the reuse of wastewater in Florida see: D Rowe and I Mohammed A Magid, Handbook of Wastewater Reclamation and Reuse, Lewis Publishers, New York, 1995, pp 428-438. Every Drop is Precious: Greywater As An Alternative Resource Page 27 legislation allowing for the installation of wastewater reuse systems, with some governments providing tax incentives.

During the six years prior to 1995, a commentator observed that: ..... greywater use has gone from being illegal everywhere in the U.S. to being legal (in some form) in many parts of the 22 western states under the Uniform Plumbing Code.103

Twenty-two of the western states of America permit the direct reuse of untreated domestic greywater for sub-surface watering which ensures contact with people is limited. Generally toilet flushing and surface watering of greywater is not permitted because of potential disease risks from contact with humans.

The United States Environmental Protection Agency published Guidelines for Water Reuse however, there are no federal regulations or standards governing greywater reuse.104 Therefore, one standard set of greywater reuse policies is not used to guide policy makers in America. A hazard in one state is viewed more benignly in another state. California passed legislation in 1992 which allowed for the liberalisation of its greywater rules. Californians’ were faced with a lingering drought and many people flouted the law in order to preserve potable water from being used for landscaping. The legislation directed the California Department of Water Resources to adopt standards for the installation of greywater systems that allowed for the safe and efficient reuse of greywater. Prior to this legislation, California’s regulations were similar to those in Australia. Greywater was considered wastewater and had to go into an approved sewer or septic system.

In California, cities and counties - the equivalent of our local government - have the option of accepting the state’s greywater standards or creating their own using the state’s minimal standards as a base. A comprehensive discussion of the California Plumbing Code that allows for the use of greywater appears in Art Ludwig’s book, Building Professional’s Greywater Guide, published in 1995.105

7.2 JAPAN

Due to a shortage of potable water in Japan, extensive wastewater reclamation occurs. This is where the water is treated to a fairly high level for toilet flushing, irrigation and for use in ornamental ponds and fountains. The treatment costs are economical in Japan because of its severe water shortages. Many multiple

103 Ludwig, Building Professional’s Greywater Guide: The guide to professional installation of greywater systems, 1995, p ii. 104 Department of Natural Resources, Queensland Wastewater Reuse Strategy: Background Paper, 1998, p 8. 105 See Appendix IV. Page 28 Every Drop is Precious: Greywater As An Alternative Resource occupancy dwellings have on-site wastewater treatment plants. Greywater reuse in single-family dwellings is limited to hand basin toilets and reuse of bathing water for clothes washing.106

8. REGULATION OF THE USE OF GREYWATER

The responsibility for water management falls to the States under the Australian Constitution. As a result, a wide range of differing standards exist, with many states not having any standards or guidelines for water reuse.

The supply of reclaimed water or recycled water direct to households for non- potable uses is a favourable water conservation option on environmental and economic grounds. However, State health authorities throughout Australia currently prevent its use through various pieces of legislation. This is despite the fact its use is accepted in other countries such as the United States and Japan. There needs to be more research to establish the technical basis for regulation policy.

In Australia, the first steps were taken towards the development of residential water recycling with the publication of the New South Wales Guidelines for Urban and Residential Use of Reclaimed Water in 1993.107 These guidelines allow the use of reclaimed water for non-potable uses including toilet flushing, garden washing and car washing.

National Guidelines for the use of reclaimed water via dual reticulation systems were prepared in 1996.108 Unfortunately, these guidelines do not deal specifically with reclaimed water from individual households, such as sullage, greywater or effluent from aerobic treatment units or septic tanks.109

However, model guidelines for domestic greywater reuse in Australia were prepared in 1996.110 The guidelines specify the criteria, procedures and components needed for the design of individual systems. Basically three different systems were

106 Jeppesen & Solley, p 7. 107 NSW Recycled Water Co-ordination Committee, NSW Guidelines for Urban and Residential Use of Reclaimed Water, 1st Edition, NSW Public Works, 1993. 108 National Health and Medical Research Council (NHMRC), Draft Guidelines for Sewage Systems: Use of Reclaimed Water, National Water Quality Management strategy: Melbourne, April 1996. 109 NHMRC, p. 1. 110 Jeppeson, Model Guidelines for Domestic Greywater Reuse for Australia, p 7. Every Drop is Precious: Greywater As An Alternative Resource Page 29 discussed. These were hand basin toilets, primary greywater systems111 and secondary greywater systems.112

The development of greywater reuse guidelines in Australia is still in its infancy.

8.1 COMMONWEALTH

In response to environmental, economic and social issues, the water industry, both nationally and internationally, is in a state of flux. Many steps towards the development of a uniform water conservation policy have occurred. At the national level, the Inter-Governmental Agreement on the Environment, endorsed in May 1992, led to the establishment of the cooperative arrangements between the Commonwealth, State, Territory and Local Governments to ensure there is national consistency in environmental policy. A National Strategy for Ecologically Sustainable Development was endorsed by all governments in Australia in December 1992. In February 1994, the Council of Australian Governments (COAG)113 released a statement on water resource policy which called for reforms in the Australian water industry over the next few decades. Specifically, it called for the education of the community on the value of water and the promotion of the need to conserve and care for Australia’s water resources. As part of the National Water Reform Framework, COAG agreed that peak councils responsible for water resource management, the environment and housing/urban development should investigate the management and ramifications of making use of wastewater. As a consequence, the Agriculture and Resources Management Council of Australia and New Zealand (ARMCANZ) commissioned the Commonwealth Scientific Investigation and Research Organisation (CSIRO) to report on wastewater reuse, which included investigations into the reuse of greywater.

The CSIRO report, commissioned by COAG, was produced in 1996114 and formed the basis of a policy discussion paper. The report115 suggested that current

111 A primary greywater system is where there is little treatment with direct sub-surface application of the resulting effluent. 112 A secondary greywater systems involves a higher level of treatment with mesh, membranes or sand filtration. 113 COAG includes the Prime Minister, Chief Ministers, Premiers and the President of the Local Government Association of Australia. 114 J F Thomas, J Gombosso, J E Oliver and V A Ritchie, Wastewater Re-use, Stormwater Management and the National Water Reform Agenda, Report to the Sustainable Land and Water Resources Management Committee and the COAG National Water Reform Task Force CSIRO Division of Water Resources, Canberra, 1996 as quoted in J F Thomas, “COAG’s Water Reform Agenda: Institutions for Reuse and Management of Wastewaters”, AWWA 17th Page 30 Every Drop is Precious: Greywater As An Alternative Resource regulatory arrangements in Australia did not facilitate wastewater reuse. Changes to legislation were required when water reuse systems were introduced in the western states of the USA.

In response to these findings, Commonwealth, State and Territory Governments have developed a National Water Quality Management Strategy for Australia. This strategy lays the foundations for a national approach to water management. Its application hold enormous potential for consistency of approach to water management issues in the long term. The strategy was jointly developed by the Australian and New Zealand Environment and Conservation Council (ANZECC), Agriculture and Resource Management Council of Australia and New Zealand (ARMCANZ) and the National Health and Medical Research Council (NHMRC). Some twenty guideline documents have been produced as a part of this process including one on wastewater reuse. However, these guidelines specifically excluded the use of greywater. As was mentioned earlier, in addition to reviews of the water industry occurring as part of COAG, it was also investigated under the National Competition Policy review. Many local authorities in Queensland have a monopoly on the provision of water and sewerage services. Under the Hilmer review, local government business activities such as water and sewerage services were required to be reviewed in order for them to become more efficient and competitive.

8.2 STATES AND TERRITORIES

The disposal of domestic wastewater in all Australian States is governed by various legislation covering health, building, sewage, clean water, plumbing and draining. All states have similar legislation that requires the discharge of all wastewater to the sewer in sewered areas, with allowance for exemption by the regulatory authority. The regulatory authority is normally the local government authority or water board. Direct greywater reuse is generally illegal in Australia. Greywater which has passed through a form of treatment may be used for irrigation in certain states and localities. Current regulations are set by health departments at a conservative level in order to avoid possible public health and environmental risks.

In non-sewered areas, greywater is traditionally recognised as a separate category of wastewater, whose fate varies again with the local administering authority. The Australian Standards AS 1547 (Disposal systems for effluent from domestic premises) is the model many areas follow.

Federal Convention, World Congress Centre, Melbourne, 16-21 March 1997, Australian Water & Wastewater Association, Artarmon, Volume 2, pp 18-23; 18. 115 Thomas, Gombosso, Oliver & Ritchie, p 20. Every Drop is Precious: Greywater As An Alternative Resource Page 31

The following is a brief discussion of greywater reuse in some jurisdictions.

8.2.1 Australian Capital Territory

The Australian Capital Territory energy and water utility is trialing different wastewater reuse systems at the single dwelling level, with the hope of making it possible for whole suburbs to become less reliant on sewerage systems.116 The trial is expected to run for up to five years. Initial findings in 1996 found that the systems could achieve overall water use reductions of up to 45 percent, translating to a saving of 200 kL of potable water annually. In this study, researchers said the trial had the added bonus of introducing a high degree of environmental ownership on the part of the water user, eliminating the “out-of-sight, out-of-mind” attitude.

8.2.2 South Australia

Interest in the use of greywater reuse systems is increasing in South Australia. Some people, even in sewered areas, are getting exemptions from the South Australian Water Authority to disconnect from the sewerage system and reuse greywater.117 A couple of these systems are using greywater for toilet flushing after treatment. However, so far the number of greywater reuse applications is still low. Under the Public and Environmental Health Act 1987, the South Australian Health Commission is the approving authority for any wastewater collection, treatment or disposal schemes in areas not serviced by the South Australian water sewerage schemes.

8.2.3 Western Australia

In Western Australia, five different methods of greywater treatment and reuse are under trial by the Murdoch University Institute for Environmental Science. Each system can be used on site for individual households or adjusted for use with a number of adjoining properties. The systems are considered cost-effective and involve a form of pollution control.118

116 A Bloomfield, “Now for something new in sewage treatment”, Local Government Management, June 1996, pp 10-12. 117 N Kayaalp, “Recycling of Reclaimed Water in South Australia”, Water, vol 24, no 1, January/ February 1997, pp 30- 32; 32. 118 The systems are reviewed in Anda, Ho and Mathew, 1997. Page 32 Every Drop is Precious: Greywater As An Alternative Resource

In 1996, the Western Australian Health Department released Draft Guidelines for Domestic Greywater Reuse in Western Australia.119 These guidelines cover hand- basin toilets, primary and secondary greywater systems. The guidelines are currently being trialed on different soil types. After the trials, a review of Western Australia’s legislation will be undertaken. 120

8.3 QUEENSLAND

Queensland appears to be at the forefront of reviewing its legislation in relation to the use of greywater. In 1993, the State Water Conservation Strategy identified greywater as an alternative water source.121 It said greywater could be used for garden watering, wetland maintenance, irrigation of recreational areas or toilet flushing so long as there was minimal contact with people. The strategy recommended that systems could be designed in new developments including single residence greywater reuse, multiple residence community schemes, multi-storey residence systems and municipal schemes.122

As an election commitment, the Coalition Government indicated its intention to spend $1 billion on new water infrastructure throughout the state. In May 1996, a task force was appointed in order to establish a strategy for the development of water infrastructure throughout Queensland over the next 15 years.123 The task force called for public submissions and held numerous public hearings and conferences on the issue. The submissions included proposals for new dams, weirs, off-stream storages, pipelines, groundwater developments, wastewater treatment and reuse, environmental management, financial incentives for private sector developments, private sector financing and operation of new infrastructure, planning and assessment studies, operation and distributional efficiency and education and training programs.124

A significant number of proposals highlighted the growing importance of wastewater treatment and reuse. The Task Force, aware of concerns associated with wastewater reuse, recommended further studies for alternative uses be appropriately funded so that the resource could be used to its full potential by Local

119 Health Department of Western Australia, Draft Guidelines for Domestic Greywater Reuse in Western Australia, Water and Rivers Commission Project, second draft, July 1996. 120 B Devine, B Bowden, J Schlafrig and R Fimmel, “Greywater Recycling in Western Australia”, Water, vol 25 no 2, March/ April 1998, pp 18-22; 21. 121 Queensland. Department of Primary Industries, State Water Conservation Strategy: A Discussion Paper, 1993, p 115. 122 Queensland. Department of Primary Industries, State Water Conservation Strategy: A Discussion Paper, p 115. 123 Water Infrastructure Task Force p xi. 124 Water Infrastructure Task Force, p xii. Every Drop is Precious: Greywater As An Alternative Resource Page 33

Government, industry and agriculture.125 They also recommended that in the longer term, the Government should aim to recover at least 50 percent of the capital costs of new water infrastructure from water users and that water users should meet fully the costs of annual operating, maintenance and refurbishment associated with their water supply.126 Such a recommendation means that the identification and adoption of technologies that allow the reuse of water resources will become a higher priority in the future for every Queenslander.

Of the 383 submissions received by the Task Force, 34 dealt with wastewater reuse and treatment.127 The proposals amounted to an expenditure of $658 million of the total cost estimated by proponents for all projects of $8.3 billion. It was not possible to determine, how many, if any, of these submissions specifically dealt with greywater reuse.

The Department of Natural Resources is responsible for water resource planning, development and management throughout Queensland. However, no single agency in Queensland is responsible for the regulation or monitoring of the water industry as a whole. Local authorities have the prime responsibility for removing sewage and other liquid wastes from domestic, commercial and industrial premises and collecting them at a central point for treatment and disposal.

8.3.1 Legislation

There are several significant pieces of legislation which control the provision of wastewater infrastructure and the management of these services within the state. Section 26 of the Queensland Local Government Act 1993 allows a local government to make laws with respect to any matter prescribed under another Act. Section 9 of the Health Act 1937 enables the delegation of health issues to local authorities. Further, section 93 of the Health Act 1937 requires a local government to construct and maintain all sewers, stormwater drains and sanitary conveniences within its area so that they do not become a nuisance or are dangerous to health. Local authorities derive further authority to administer wastewater infrastructure from the Standard Sewerage Law.

The Sewerage and Water Supply Act 1949 establishes the Standard Sewerage Law which is administered by the Department of Natural Resources. The Standard

125 Water Infrastructure Task Force, p xvi. 126 Water Infrastructure Task Force, p xvii. 127 Water Infrastructure Task Force, p 50. Page 34 Every Drop is Precious: Greywater As An Alternative Resource

Sewerage Law was repealed and extensively revised in April 1998,128 but its intent remains the same.129 Section 15 of the new Standard Sewerage Law states that: The owner of premises in a local government’s sewered area must make sure that - a) the soil or waste pipes from all fixtures on the premises, including water closet pans, urinals, sinks, baths, clothes washers and dishwashers, discharge into sanitary drainage; and b) all sanitary drainage on the premises discharges to the local government’s sewerage system for the sewered area.

In addition, section 20(1) requires all human and liquid wastes to be discharged into the sewerage system and not onto the premises. Consequently, it is illegal to use greywater for any purpose, in areas connected to reticulated sewage. Therefore for the legal application of domestic greywater for watering of lawns and gardens to occur in sewered areas, state legislation would need to be amended.

There has been a degree of inconsistency in the regulation of greywater use in unsewered areas compared with sewered areas. Under the repealed Standard Sewerage Law, home owners used greywater in unsewered areas for many years with few restrictions placed on its use. Under that Law, the local authority had the power to make its own policy regarding greywater use in unsewered areas. Under section 92 of the new Standard Sewerage Law130, the local government may still approve the installation of an on-site sewerage facility however there are more limitations placed on the local authority’s approval.131 Installation of such a system can only occur under certain circumstances according to certain standards132 and a Code.133 For example, under the Code, it is expected that the quality of greywater disposed of at the ground’s surface will have to be of the standard that comes from a treatment plant.134 Currently there is an interim code of practice which is before water industry stakeholders and local authorities for comment.135

Under the National Competition Principles agreed to by the Queensland Government, it is obliged to review all state legislation in order to identify anti- competitive provisions.136 This review process began in 1995 and is expected to be

128 Standard Sewerage Law, Subordinate Legislation No 99 of 1998 gazetted on 24 April 1998. 129 Personal communication with Department of Natural Resources staff, 25 May 1998. 130 Personal communication with Department of Natural Resources staff, 27 May 1998. 131 Standard Sewerage Law, ss 74-75. 132 Standard Sewerage Law, s 74. 133 Standard Sewerage Law, s 75. 134 Personal communication with Department of Natural Resources staff, 27 May 1998. 135 Personal communication with Department of Natural Resources, 27 May 1998. 136 Clause 5, Competition Principles Agreement. Every Drop is Precious: Greywater As An Alternative Resource Page 35 completed by June 1999. The Sewerage and Water Supply Act 1949 is one of the Acts to be reviewed. It is expected that this review will be complete by the end of 1998.

Other legislation also applies to the use of greywater in Queensland. Section 87(1) of the Health Act 1937 requires that greywater disposed of in an unsewered area must not be allowed to remain in any one place for more than 24 hours after a local government has given notice to remove it. The greywater is also not allowed to run-off from any premises or cause offensive odours. Section 87(2) requires the local government to control any problem which may arise under section 87(1).

8.4 GUIDELINES AND POLICIES DEVELOPED BY OTHER STATUTORY BODIES AND ASSOCIATIONS

The Queensland Branch of the Australian Water and Wastewater Association published its policy on greywater reuse in April 1997. This policy states137: The re-use of greywater as non-potable water is feasible and should be encouraged provided that adequate treatment is carried out and the treatment system is maintained to a safe operating performance level and to the requirements of the Water Supply and Sewerage Act.

The AWWA believes that review and amendment of the Standard Sewage Law is required in order to permit greywater reuse. They recommend that if greywater is permitted, performance monitoring should be provided. This could be by the local authority.

9. QUEENSLAND GOVERNMENT POLICY DEVELOPMENT

The Queensland Government is currently investigating options which may lead to a change in legislation allowing the reuse of greywater.

9.1 GREYWATER POLICY OPTIONS PAPER

The State Water Conservation Strategy discussion paper released in September 1993 recommended that a system for the reuse of greywater and wastewater be developed.138 As a result, the Policy Options Paper: The Use of Greywater was

137 Australian Water and Wastewater Association, p 20. 138 Queensland. Department of Primary Industries, State Water Conservation Strategy: A Discussion Paper, p ix. Page 36 Every Drop is Precious: Greywater As An Alternative Resource released by the state government in January 1996.139 The paper aimed to “stimulate discussion about the possible strategies the Government might employ to encourage water conservation, in particular the use of greywater as an alternative water source”.140 According to the policy options document, the Government is committed to investigating alternative sources of water supply, such as greywater, through its State Water Conservation Strategy.

The policy paper presents three options for consideration:141

Option 1: The current arrangements of allowing greywater use only in unsewered areas are retained but with Local Government implementing additional measures to safeguard public health standards and to protect the environment.

Option 2: The use of greywater is permitted and encouraged as a water conservation strategy in both sewered and unsewered areas but only to the extent that such practices do not result in a deterioration of public health standards or cause environmental harm.

Option 3: Extend Option 1 to incorporate the active promotion of reclaimed wastewater use by such methods as dual reticulation systems. For this option, reclaimed wastewater quality must meet appropriate public health and environmental standards.

See Appendix 1 for a table outlining the advantages and disadvantages of each option.

To oversee the creation of a greywater reuse policy, a Greywater Steering Committee has been created within the Department of Natural Resources. Submissions commenting on the policy options paper closed in March 1996. It is expected that once these submissions have been reviewed, a draft of the recommended policy will be circulated to interested parties. The policy will then be finalised by the Steering Committee and presented to the Minister with recommendations for further progress. It is currently anticipated this process will be completed by the end of 1998, in conjunction with the National Competition Policy review of the Sewerage and Water Supply Act 1949.142

139 Queensland. Department of Primary Industries, Policy Options Paper: The Use of Greywater. 140 Queensland. Department of Primary Industries, Policy Options Paper: The Use of Greywater, Foreword. 141 Queensland Department of Primary Industries, Policy Options Paper: The Use of Greywater, Summary. 142 Personal communication, Department of Natural Resources staff, 13 January, 1998. Every Drop is Precious: Greywater As An Alternative Resource Page 37

9.2 INTERIM GUIDELINES FOR REUSE AND DISPOSAL OF RECLAIMED WASTEWATER

The Department of Natural Resources published Interim Guidelines for Reuse or Disposal of Reclaimed Wastewater in April 1996. These guidelines were aimed at assisting in the selection of the most practicable, safe and cost effective method of either using reclaimed wastewater or disposing of it to land in a safe manner. In general these guidelines conform with the values expressed in the NHMRC draft guidelines.

9.3 QUEENSLAND WASTEWATER REUSE STRATEGY

In March 1998, the Queensland Government released the Queensland Wastewater Reuse Strategy. In this document, the government announced its intention to develop a strategy allowing for the optimum use of wastewater including domestic, industrial and rural effluent as well as storm water.143 Specific funding of $500 000 was committed to the first year of the strategy’s development. It is expected the strategy will be completed within three years.

The background paper on the proposed Queensland Wastewater Reuse Strategy claims the strategy will allow “the greatest use of our water for the development of the State without compromising in any way, the public health and environmental concerns of the community and industry”.144 It is expected the strategy will provide an operating framework to support and facilitate wastewater reuse in Queensland. This will include determining state government policies for the sustainable use of wastewater and stormwater providing guidance to those responsible for wastewater and stormwater management in Queensland, potential users, the general community and interested groups. Therefore the development of this strategy will greatly affect the implementation of greywater reuse systems in Queensland.

10. CONCLUSION

There are a myriad of wastewater reuse options available to relevant authorities. However, greywater reuse is one of the few options readily available for potential application by individual householders who often ask how their actions affect the “big picture”. As noted earlier in this Bulletin, a family's water savings would be around 30-50% of their total household usage through the installation of a greywater system.

143 Queensland Department of Natural Resources, Queensland Wastewater Reuse Strategy. 144 Queensland Department of Natural Resources, Queensland Wastewater Reuse Strategy, p iii. Page 38 Every Drop is Precious: Greywater As An Alternative Resource

Greywater reuse is not a high profile water conservation topic at the moment in Queensland, nor in fact, any other Australian jurisdiction. Although its use is being investigated, other water resource options are currently preferred. This was clearly exhibited in the final report of the Water Infrastructure Task Force145 where other water issues, such as dam and weir construction, were addressed and highly recommended. However, a conceptual shift is being advocated from many quarters that greywater be seen as a resource available for utilisation rather than a waste requiring disposal.

Widespread practice of domestic greywater reuse in both Australia and overseas has occurred for many years with few complaints or problems experienced. This is encouraging given the substantial water savings potentially offered by the adoption of greywater reuse systems. Some caution must be exercised because of unknown factors associated with health and the environment of the long-term and more common use of greywater. However, caution should not be misconstrued to mean abandonment of the issue. Technologies and practices exist which can minimise harm and these could be implemented and promoted through education programs.

The solution to Australia’s water supply problems will require a variety of approaches from education, engineering, legislation, regulation and economic incentives and disincentives. Water conservation combined with the reuse of water will help overcome our future potential water dilemma.

145 Water Infrastructure Task Force. Every Drop is Precious: Greywater As An Alternative Resource Page 39

BIBLIOGRAPHY

MONOGRAPHS

· Australia Department of the Environment, Sport and Territories, Australia: State of the Environment 1996, CSIRO Publishing, Collingwood, 1996.

· Australia. Senate Standing Committee on Environment, Recreation and the Arts, Water Resources - Toxic Algae, Australian Parliamentary Papers No 387 of 1993, AGPS: Canberra, December 1993.

· Denlay, J and Dowsett, B, Water Reuse the most reliable water supply available, a report prepared as part of the Sydney Water Project, Friends of the Earth Inc, Sydney, November 1994.

· Gutteridge, Haskins and Davey, Department of Resources and Energy, Water technology, Reuse and Efficiency, Water 2000: Consultants Report No 10, AGPS: Canberra, 1983.

· Health Department of Western Australia, Draft Guidelines for Domestic Greywater Reuse in Western Australia, Water and Rivers Commission Project, second draft, July 1996.

· Hilmer, F G, Rayner, M R and Taperall, G Q, National Competition Policy: Report by the Independent Committee of Inquiry, AGPS, Canberra, August 1993.

· Industry Commission, Water Resources and Waste Water Disposal, Report no 26, AGPS, Canberra, 17 July 1992, Australian Parliamentary Paper no 239 of 1992.

· Jeppesen, B, Domestic Greywater Reuse: Preliminary Evaluation, Urban Water Research Association of Australia Research Report No 60, July 1993.

· Jeppeson, B, Model Guidelines for Domestic Greywater Reuse for Australia, Urban Water Research Association Research Report No 107, Melbourne, 1996.

· Jeppesen, B and Solley, D, Domestic Greywater Reuse: Overseas Practice and its Applicability to Australia, Urban Water Research Association of Australia Research Report No 73, March 1994.

· Ludwig, A, Building Professional’s Greywater Guide: The guide to professional installation of greywater systems, Oasis Design, Santa Barbara, 1995. Page 40 Every Drop is Precious: Greywater As An Alternative Resource

· Ludwig, A, Create an Oasis with Greywater, Oasis Design, Santa Barbara, Revised 2nd edition, 1997.

· National Health and Medical Research Council (NHMRC), Draft Guidelines for Sewage Systems: Use of Reclaimed Water, National Water Quality Management Strategy: Melbourne, April 1996.

· NSW Recycled Water Co-ordination Committee, NSW Guidelines for Urban and Residential Use of Reclaimed Water, 1st Edition, NSW Public Works, 1993.

· Queensland Department of Natural Resources, Guidelines for Evaluation of Introducing and Improving Two Part Tariffs, Brisbane, November 1997.

· Queensland Department of Natural Resources, Queensland Wastewater Reuse Strategy, 1998.

· Queensland Department of Natural Resources, Water Infrastructure Planning and Development 1997-98 to 2001-02 Implementation Plan, Queensland Government, Brisbane, July 1997.

· Queensland Department of Primary Industries, Policy Options Paper: The Use of Greywater, Rural and Resource Development Group, Brisbane, January 1996.

· Queensland Department of Primary Industries, State Water Conservation Strategy: A Discussion Paper, DPI Water Resources, Brisbane, September 1993.

· Rowe, D and Abdel-Magid, I, Handbook of Wastewater Reclamation and Reuse, Lewis Publishers, New York, 1995.

· Simpson, J and Oliver, P, Water Quality: From wastewater to drinking water to even better, Australian Water & Wastewater Association, Artarmon, 1996.

· Water Infrastructure Task Force, Report to the Minister for Natural Resources, 28 February 1997.

· Waterwise Queensland, Waterwise in the Home, Department of Natural Resources, Fact Sheet 2.

· Waterwise Queensland, Be Waterwise at Home: If water came in buckets, how many would you use each day?, Department of Natural Resources. Every Drop is Precious: Greywater As An Alternative Resource Page 41

PAPERS

· Anda, M, Ho, G and Mathew, K, “Greywater Reuse: Some Options for Western Australia”, Designing for a Sustainable Future, Proceedings of the Sixth International Permaculture Conference & Convergence, Perth and Bridgetown, 27 September to 7 October 1996, Permaculture Association of Western Australia, 1997. Available at Internet location: http://www.cowan.edu.au/~paustin/ipc6/ch08/marshall/index.htm

· Anderson, J, “Water Conservation and Recycling in Australia: Scenarios for sustainable urban water use in the 21st Century”, Delivering the Vision for the Next Century, Proceedings of the sixteenth Federal Convention of the Australian Water and Wastewater Association, Darling Harbour Sydney Australia, 2-6 April 1995, Volume 1, pp 389-395.

· Australian Water and Wastewater Association, AWWA Queensland Branch Policies, AWWA, Brisbane, April 1997.

· Crockett, J and Carroll, L, “Water: Consume Less and Pay More”, AWWA 17th Federal Convention, World Congress Centre, Melbourne, 16-21 March 1997, Australian Water & Wastewater Association, Artarmon, Volume 2, pp 90-97.

· Gardner, T, Bryan, A, Hu, X, Gordon, I and Beavers, P, “Land Disposal of Sewage Effluent in Queensland: A survey of current practice and future opportunities”, Effluent Treatment: Disposal and Reuse, Seminar Notes, Queensland Department of Environment and Heritage and the Department of Primary Industries, 17-19 May 1995, pp 1-18.

· Jeppesen, B, “Greywater Re-Use”, in Recycled Water Seminar 19-20 May 1994, Newcastle City Hall Proceedings, AWWA NSW Branch: Newcastle, pp 197-204.

· Jones, K, Lewis, T and Aitken, K, “Waterwise Queensland The Joint Venture”, Water - Every Drop is Precious, the 15th Federal Convention of the Australian Water and Wastewater Association, Hotel Conrad, Gold Coast, 18-23 April 1993, Volume 1, pp 268-274.

· Law, I, “Domestic Non-potable Reuse - Why even consider it”, AWWA 17th Federal Convention, World Congress Centre, Melbourne, 16-21 March 1997, Australian Water & Wastewater Association, Artarmon, Volume 2, pp 135-142.

· Marshall, G, “Greywater Re-Use: Hardware, Health, Environment and the Law”, Designing for a Sustainable Future, Proceedings of the Sixth International Permaculture Conference & Convergence, Perth and Bridgetown, 27 September to 7 October 1996, Permaculture Association of Western Page 42 Every Drop is Precious: Greywater As An Alternative Resource

Australia, 1997. Available at Internet location: http://www.cowan.edu.au/~paustin/ipc6/ch08/marshall/index.htm

· Thomas, J F, Gombosso, J, Oliver J E and Ritchie, V A, Wastewater Re-use, Stormwater Management and the National Water Reform Agenda, Report to the Sustainable Land and Water Resources Management Committee and the COAG National Water Reform Task Force CSIRO Division of Water Resources, Canberra, 1996 as quoted in J F Thomas, “COAG’s Water Reform Agenda: Institutions for Reuse and Management of Wastewaters”, AWWA 17th Federal Convention, World Congress Centre, Melbourne, 16-21 March 1997, Australian Water & Wastewater Association, Artarmon, Volume 2, pp 18-23.

JOURNAL ARTICLES

· Beavers, P, "Greywater: An alternative water source?", Effluent Reuse and Alternative Treatment Seminar, Townsville, 17-19 May 1995.

· Bloomfield, A, “Now for something new in sewage treatment”, Local Government Management, June 1996, pp 10-12.

· Compagnoni, M, “Creative ways with sewage”, Australasian Science, 19(1), February 1998, pp 22-24.

· Davis, C, “Wastewater Treatment in Australia”, Waste Management and Environment, 4(10), 1 September 1993, pp 26-30, 33-34,, 36-37.

· Devine, B, Bowden, B, Schlafrig, J and Fimmel, R, “Greywater Recycling in Western Australia”, Water, 25(2), March/ April 1998, pp 18-22.

· “Greywater”, Waves, 3(4), December 1996, p 9.

· Jones, K, Lewis, T and Aitken, K, “Waterwise Queensland - the joint venture”, Water, 20(3), June 1993, pp 12-15.

· Kayaalp, N, “Recycling of Reclaimed Water in South Australia”, Water, 24(1), January/ February 1997, pp 30- 32.

· Law, I, “Domestic Non-potable Reuse: Why even consider it?”, Water, May/June 1997, 24(1), pp 9-13.

· MacDermott, M, “Plan for potable sewage water”, Australian Environment Review,10(2), February 1995, p 12.

· Marcus, R, “Recycled waste water: Denver’s Scheme”, Popular Science, September 1987, 231(3), p 44.

· Said, D, “Drinking Sewage and loving it”, Australian Environmental Review, August 1996, 11(7), p 14. Every Drop is Precious: Greywater As An Alternative Resource Page 43

· Sziapinski, P, “Recent Australian Trends in Wastewater reuse”, Waste Disposal and Water Management in Australia, August 1995, pp 3-9.

· Vidal, J, “Next, Wars over Water? As the World Runs Dry”, World Press Review, November 1995, 42 (1), pp 8-13.

NEWSPAPER CLIPPINGS

· Bartsch, P, “Coast plan to recycle its sewage”, Courier Mail, 27 April 1996, p 19.

· Bevan, J, “Dry areas wiser by the meter”, Courier Mail, 24 November 1997, p 4.

· Hele, M, “Sewage plants fail test - 196 exposed in crackdown”, Courier Mail, 2 September 1994, p16.

· Petersen, D, “Turning sewage into fresh water”, Courier Mail, 29 April 1996, p 7.

· Riggert, E, “Pools to stay open despite discovery of deadly bug”, Courier Mail, 13 March 1998, p 7.

LEGISLATION

· Sewerage and Water Supply Act 1949 (Qld)

· Standard Sewerage Law, Subordinate Legislation No 99 1998 gazetted on 24 April 1998. Page 44 Every Drop is Precious: Greywater As An Alternative Resource Every Drop is Precious: Greywater As An Alternative Resource Page 45

GLOSSARY algal blooms a sudden growth of algae, water weed or other primitive plant. Biochemical BOD is a measure of the biological consumption of oxygen in Oxygen Demand water, especially as a result of the breakdown of organic (BOD) matter by microorganisms. Biosolids sludge extracted from wastewater/effluent which is potentially able to be used beneficially. blackwater domestic wastewater containing faecal matter and kichen waste. domestic waste water borne waste derived from human origin comprising faecal matter, urine and liquid household waste from water closet pans, sinks, baths and basins. dual distribution distributes two grades of water, one potable and the other systems nonpotable - to the same service area. The quantity, quality and pressure available in each are functions of the sources and intended uses for each grade of water. Effluent a complex waste material, such as liquid industrial discharge or sewage, that may be discharged into the environment. The relationship between wastewater and effluent is ill-defined and confused. Faecal coliforms The bacteriological content of wastewater that comes from bodily wastes. Greywater Domestic wastes from baths, showers, basins and laundries including floor wastes from these areas. It does not include toilet, bidet, kitchen or dishwasher wastewater. Sometimes called sullage. See definition of sullage for clarification. Greywater system means any appliance, fitting or device that reuses greywater. Groundwater subsurface water from which wells or springs are fed. Strictly, the term only applies to water from below the water table. Hand basin toilet a toilet suite that incorporates a hand basin in the top of the cistern with a water spout for hand washing. The water spout operates automatically upon flushing the toilet, simultaneously refilling the cistern and allowing hand washing. These toilets are installed in most Japanese homes and commercial areas. There is some limited use of these systems in USA, Canada and Europe. Irrigation the distribution of water for the growth, leaching, cooling, treating, humidifying, frost protection and water replenishment of the soil for plants, turf, lawns, gardens, nurseries, agriculture, crops, forests, flowers and horticulture. Page 46 Every Drop is Precious: Greywater As An Alternative Resource kL means kilolitre, or 1000 litres. This is the same as one cubic meter of water or one tonne of water. non-potable water is acceptable for uses other than potable. potable water water suitable for human consumption whether for drinking or culinary uses. This grade of water should conform to the drinking water quality requirements, both health and aesthetic, of state and federal regulatory agencies. Primary Any greywater system that directly reuses untreated domestic greywater system greywater, sourced from the bathroom and laundry only, from a single family home for sub-surface lawn and ornamental garden watering. These systems do not allow storage or treatment, apart from a coarse screen filter which removes lint, hair and coarse particles. Reclaimed water derived from wastewater and treated to a level wastewater appropriate for its intended application. The difference between reclaimed wastewater and recycled water is ill- defined and often confused. Recycled water to return water for further use after some type of treatment. Reticulation A network of pipes to which service pipes of individual properties are connected. Secondary greywater systems where treatment of the water is to a higher greywater system level than primary greywater systems. They may be used for multiple occupany dwellings. They can also store greywater for treatment purposes only for reuse in subsurface lawn and garden watering. Sewage The wastewater from homes, offices, shops and factories. It includes faecal matter, urine, household and commercial wastewater. Sewerage All the pipes, sewers and ancillary works required for the conveyance, treatment and disposal of sewage. Sullage Domestic wastes from baths, showers, basins, kitchens and laundries including floor wastes from these areas. Sullage differs from the definition of greywater because greywater does not include kitchen or dishwasher wastewater. See Australian Standard AS 3500 - 1990, glossary.

Wastewater a combination of the liquid or water-carried wastes removed from residences, institutions, commercial and industrial establishments together with groundwater, surface water and storm water as may be present. It has no further immediate value to the process that produced it. The relationship between wastewater and effluent is ill-defined and confused. Every Drop is Precious: Greywater As An Alternative Resource Page 47

APPENDIX 1: ADVANTAGES AND DISADVANTAGES OF POLICY OPTIONS Impacts Option 1: Option 2: Option 3: Greywater Unsewered Greywater All Areas Combined Treated Areas Wastewater Use Allows greywater use in unsewered Yes Yes Yes areas Allows greywater use in sewered No Yes Not separately areas Revision to Standard Sewerage Law Yes (minimal) Yes Yes Sewage Minimisation strategy No Yes Yes development Reduces demand on potable water No Yes Yes supply Risk to public health Minimal - if disposed Some Some properly in ground Environmental risk Improves (with control Risk Increases (no Minimal (plant implemented) control on use) breakdown) Homeowners apply water No Yes Yes conservation strategies Impact on Existing Sanitary No Yes (reduction in Yes Sewerage System discharge to sewer) Minimises contamination of soil on- No No Yes site Beneficial use of nutrients in Minimal Yes More greywater & reclaimed wastewater Reduction in nutrient load on Only if well controlled Yes Yes surface waters Savings in capital expenditure No Yes, provided bulk of Yes through deferral of headworks community use greywater Community pays extra cost for No No Yes ($2500 - $4500) advanced treatment and infrastructure Capital cost to householder for $1500 - $2500 $1500 - $2500 $1000 - $2000 installation Annual maintenance cost to $50 $50 $10 householder Annual savings to householder in - $40 $50 potable water costs Cost implications to Additional cost to monitor Additional resources to Upgrade STP146 or Council/ratepayers/ community administer and monitor construct new STP. Additional resources to administer and monitor Risk to community amenity through Some (even with controls) Higher (due to smaller Minimal (due to high seepage average block sizes) standard treatment)

Source: Queensland Department of Primary Industries, Policy Options Paper: The Use of Greywater, Rural and Resource Development Group, Brisbane, January 1996, p iii.

146 STP stands for Sewerage Treatment Plant