Research reports & science
Research reports and science behind the GreySmart website and GreySmart product ranking system.
- National Water CommissionRequirements for the installation of rainwater and greywater systems in Australia
- Australian Bureau of StatisticsGreywater use in Australia is growing! Take a look at the ABS website to see how you measure up compared to the rest of the country.
The science behind GreySmart
The GreySmart Household Product Assessment tool was developed using the framework of the Australia Guidelines for Water Recycling (2006).
The research behind this ranking of products firstly identified the hazards that should be considered when greywater is used on household gardens. These hazards were identified as follows:
- Acidity/alkalinity or pH
- Electrical conductivity or salinity – a measure of the dissolved salt content of water
- Boron – present in some laundry detergents to reduce water hardness and aid bleaching
- Cadmium – a contaminant in some components of powder laundry detergents
- Phosphorus and Nitrogen – present in many solid and liquid laundry detergents
- Sodium adsorption ratio - a ratio of the sodium (detrimental element) to calcium and magnesium (beneficial elements) and is related to known effects on soil surface structure and soil stability
- Residual sodium carbonate – calculated using milli-equivalents of calcium, magnesium, carbonates, and bicarbonates and combined with Sodium Adsorption Ratio to evaluate impact of carbonates on the sodium hazard in water applied directly to the soil.
- Degradability of organic chemicals – there are many organic chemicals in both powder and laundry detergents
- Zinc was also identified for specific cases where sunscreen or certain antidandruff shampoos were used. These products should be used minimally if using shower water for irrigation of household gardens. Zinc was not included in the ranking system as the likelihood of excessive zinc buildup in soils was considered very low.
This research then developed a ranking system based on the frame described in the Australian Guidelines for Water Recycling.
Summary of ranking system
Summary of individual trigger values for hazards, impact ratings and associated risk level
| Risk | Risk score | Impact | EC dS/m |
pH | B mg/L |
Total N mg/L |
Total P mg/L |
SAR (mmolc/L)0.5 |
Cd mg/L |
RSC meq/L |
|
| Low | 6 | Insignificant | <1.0 | 6.4 to <7.5 | <0.49 | <1.8 | <0.3 | <8.0 | <0.01 | <0 | |
| Moderate | 7 | Minor | 1.0 to <1.4 | 6.0 to <6.4 | 7.5 to <8.0 | 0.49 to <0.55 | 1.8 to <2.8 | 0.3 to <0.5 | 8.0 to <10 | 0-1.25 | |
| High | 8 | Moderate | 1.4 to <2.7 | 5.5 to <6.0 | 8.0 to <8.6 | 0.55 to <0.74 | 2.8 to <7.2 | 0.5 to <1.2 | 10 to <11 | 1.25-2.5 | |
| Very high | 9 | Major | 2.7 to <3.9 | 4.9 to <5.5 | 8.6 to <9.1 | 0.74 to <1.00 | 7.2 to <11 | 1.2 to <1.9 | 11 to 20 | 0.01 to <0.05 | >2.5 |
| Very high | 10 | Catastrophic | ≥3.9 | <4.9 | ≥9.1 | ≥1.00 | ≥11 | ≥1.9 | ≥20 | 0.05 | |
Annual irrigation with grey water assumed to be 600 mm/year
Loam soil was assumed for SAR assessment
Base water quality used was Melbourne's potable water (Sept 2010).
Risk score assumes likelihood of irrigation is almost certain.
EC = electrical conductivity, B= Boron N = nitrogen, P = phosphorus, SAR = Sodium adsorption ratio, Cd = Cadmium and RSC = Residual sodium carbonate
For more information see:
Ozwater paper
Stevens D, Harris C, Hannaford J, Wilson S (2010) Environmentally friendly use of greywater through selecting greysmart household products. In: Ozwater 10. AWA, Australia, Brisbane Australia.
Review for SEWL of household products
D. Stevens and S. Wilson, Greywater review and development of a management matrix (20 Corporate Drive, Heatherton, Victoria, Australia: Arris Pty Ltd for South East Water Limited, 2009)
Individual risk scores were averaged and the overall risk assessed (GreySmart assessment) using the following table.
| Average risk score | Risk | GreySmart assessment |
| ≤6.3 | lowest | GreySmart |
| >6.3 to 6.5 | low | GreySmart with care |
| >6.5 to 7.5 | moderate | Fail |
| >7.5 to 8.5 | high | Fail |
| >8.5 to 10 | very high | Fail |
For more information see:
Ozwater paper
Stevens D, Harris C, Hannaford J, Wilson S (2010) Environmentally friendly use of greywater through selecting greysmart household products. In: Ozwater 10. AWA, Australia, Brisbane Australia.
Review for SEWL of household products
D. Stevens and S. Wilson, Greywater review and development of a management matrix (20 Corporate Drive, Heatherton, Victoria, Australia: Arris Pty Ltd for South East Water Limited, 2009)
Lanfax – Key papers and information on greywater
Van de Graff R, Patterson R (2001) Explaining the mysteries of salinity, sodicity, SAR and ESP in on-site practice. In: Advancing On-site Wastewater Systems. University of New England, Armidale.
Patterson R (1997) Domestic wastewater and the sodium factor. In: Site Characterization and Design of On-Site Septic Systems, Lanfax Laboratories, Armidale, Australia, pp 23-35.
Patterson R (2007) Greywater reuse- impact of household chemicals on useability. Lanfax Laboratories.
Patterson R (2009a) Laundry Products Survey 2009.
Patterson R (2009b) Laundry Products Research - 2009.
Patterson R (2004) How eco is your laundry powder? ReNew 94:57-58.
Tu SI, Patterson D, Brauer D, Hsu AF Effects of H+-Atpase Activities On Cd2+ Movement Induced By Nadh-Linked Electron Transfer in Root Plasma Membrane Vesicles. Journal of Plant Physiology 1998 Oct; 153(3-4):347-353.
Whitehead J, Patterson R (2007) Assessing sustainable greywater reuse and application rates.
Relevant literature
ATA (2008) Using Greywater. The essential guide to collection and use. Alterantive Technology Association, Melbourne, Australia.
Christova-Boal D, Eden R, McFarlane S (1996) An investigation into greywater reuse for urban residential properties. Desalination 106:391-397.
Diaper C (2004) Innovation in on-site domestic water management systems in Australia: A review of rainwater, greywater, stormwater and wastewater utilisation techniques. Australian Water Conservation and Reuse Research Program, CSIRO Urban Water CSIRO MIT. Technical Report 2004-073 April 2004.
Diaper C, Toifl M, Storey M (2008) Greywater Technology Testing Protocol. CSIRO.
DoH SA (2007) Manual Bucketing & Temporary Diversion of Greywater.
Department of Health, Wastewater Management Section, Government of South Australia, Adelaide.
DoH Vic (2007) Greywater recycling: appropriate uses. Department of Human Services, Victoria, Australia, Melbourne.
EPA Victoria (2008) Greywater use around the home.
Eriksson E, Andersen HR, Madsen TS, Ledin A (2008) Greywater pollution variability and loadings. Ecological Engineering In Press, Corrected Proof.
Gardner T, Millar G (2003) The Performance of a Greywater System at the Healthy Home in South East Queensland - 3 years of data. In: On-Site 03. Future Directions for On Site Systems. Lanfax Labs. pp. 145-152., Armidale, October 2003,
Gerba C, Straub T, Rose J, Karpiscak M, Foster K, Brittian R (1995) Water quality of greywater treatment system. Water Research 31:109-116.
Landloch Pty Ltd. (2005) Laundry Grey water potential Impact on Toowoomba soils - Final Report. Prepared by Landloch Pty Ltd and the National Centre for Engineering in Agriculture University of Southern Queensland, Toowoomba for the Toowoomba City Council November 2005. NCEA Publication NCEA 1001420/2, Toowoomba, Qld.
Lazarova V, Hills S, Birks R (2003) Using recycled water for non-potable, urban uses: a review with particular reference to toilet flushing. Water Science & Technology: Water Supply 3:69-77.
Meehan B, Maxey A (2009) Potential impacts of using greywater for domestic irrigation. Prepared by RMIT Environmental Science Department for the Alternative Technology Assocation, Melbourne.
Namdarian F (2007) The impact of greywater irrigation systems on domestic soil environments summary.
NWC (2008) Requirements for rainwater and greywater systems in Australia. Master Plumber and Mechanical Services Association of Australia for the National Water Commission and Standards Australia, Canberra, Australia.
Patterson R (2007) Greywater reuse- impact of household chemicals on useability. Lanfax Laboratories.
Qld DIP (2007) Greywater. Guidelines for councils. Use of greywater for residential properties in Queensland sewered areas. Department of Infrastructure and Planning, Brisbane, Qld, Australia.
Qld NRW (2008) Waterwise Queensland: Gardening with greywater. Queensland Government Natural Resources and Water.
Redwood M (2008) Greywater irrigation: challenges and opportunities. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources 3.
Roesner L, Qian Y, Criswell M, Stromberger M, Klein S (2006) Long-term effects of landscape irrigation using household graywater - Literature review and synthesis. Water Environment Research Foundation and Soap and Detergent Association, Alexandria, VA, USA and Washington DC, USA.
Tjandraatmadja G. (2008) Reducing pollution that goes down the drain. CSIRO News Dec:www.csiro.au/news/newsletters/water/0812_water/story06.htm.
Travis MJ, Weisbrod N, Gross A (2008) Accumulation of oil and grease in soils irrigated with greywater and their potential role in soil water repellency. Science of The Total Environment 394:68-74.
Wiel-Shafran A, Ronen Z, Weisbrod N, Adar E, Gross A (2006) Potential changes in soil properties following irrigation with surfactant-rich greywater. Ecological Engineering 26:348-354.
Guidelines and fact sheets
A-Boal D, Lechte P, Shipton R (1995) Installation and evaluation of domestic greywater reuse systems. Victoria University of Technology, Australia.
ACT Health (2007) Greywater Use. Guidelines for residential properties in Canberra. Second Edition, published October 2007. ACT Health, Health Protection Service, Canberra, ACT.
Avvannavar SM, Mani M (2007) Guidelines for the safe of wastewater, excreta and greywater. Science of the Total Environment 382:391-392.
DEUS (2007) NSW Guidelines for Greywater Reuse in Sewered, Single Household Residential Premises. Department of Energy, Utilities and Sustainability. NSW Government, Sydney, NSW, Australia.
Devine B, Bowden B, Schlafrig JE, Fimmel RJ (1998) Greywater recycling in Western Australia.
Water (Artarmon, Australia) 25:18-22. DHCS N (2007) Information Bulletin No. 2. Environmental Health.
Greywater Reuse in Single Domestic Premises. Department of Health and Community Services, Darwin, NT, Australia.
Dixon AM, Butler D, Fewkes A (1999) Guidelines for greywater re-use: Health issues. Journal of the Chartered Institution of Water and Environmental Management 13:322-326.
DNREA NT (2007) GREYWATER REUSE: Technical Fact Sheet. Department of Natural Resources, Environment and the Arts, Northern Territory Government, Darwin, NT, Australia.
DoH SA (2006a) Application for alternative on-site wastewater/waste control system installation. Department of Health, Wastewater Management Section, Government of South Australia, Adelaide.
DoH SA (2006b) Draft Guidelines for Permanent Onsite Domestic Greywater Systems: Greywater Products and Installation. Department of Health, Wastewater Management Section, Government of South Australia, Adelaide.
DoH SA (2006c) Installation of Permanent Onsite Domestic Greywater Systems. Department of Health, Wastewater Management Section, Government of South Australia, Adelaide.
DoH SA (2007a) Manual Bucketing & Temporary Diversion of Greywater.
Department of Health, Wastewater Management Section, Government of South Australia, Adelaide.
DoH SA (2007b) Approved Wastewater Products for marketing, sale and installation in South Australia.
DoH Vic (2007) Greywater recycling: appropriate uses. Department of Human Services, Victoria, Australia, Melbourne.
DoH WA (2001) Code of Practice for the Design, Manufacture, Installation and Operation of Aerobic Treatment Units (ATUs). Serving Single Dwellings November 2001. Department of Health, Perth, WA,
DoH WA (2002) Draft Guidelines for the reuse of greywater in Western Australia. Department of Health, Perth, WA, DoH WA (2005) Code of Practice for the Reuse of Greywater in Western Australia. Department of Health, Perth, WA.
EPA Victoria Greywater use around the home.
EPA Victoria (2003) Septic Tank Code of Practice. Guidelines for environmental management. EPA Victoria, Southbank, Victoria 3006, Australia.
EPA Victoria (2006) Information Bulletin. Domestic wastewater management series. Reuse options for household wastewater. Publication 812.2. Environmental Protection Authority Victoria, Melbourne.
EPA Victoria (2008a) Greywater use around the home.
EPA Victoria (2008b) Guidelines for Environmental Management: Code of practice - onsite wastewater management. EPA Victoria, Southbank, Victoria 3006, Australia.
LGP (2003) Onsite Sewage Facilities. Guidelines for the use and disposal of greywater in unsewered areas.
NSW Health (2000a) Greywater reuse in sewered single domestic premises.
NSW Health (2000b) Greywater Reuse in Sewered Single Domestic Premises. New South Wales Health, Gladesville, NSW, Australia.
NSW Health (2005) Domestic greywater treatment system accreditation guidelines. Part 4, Clause 43(1), Local Government (Approvals) Regulation, 1999. New South Wales Health, Gladesville, NSW, Australia.
NSW RWCC (1993) NSW Guidelines for Urban and Residential Use of Reclaimed Water. The NSW guidelines for urban and residential use of reclaimed water (1993) are no long recommended for use and have been replaced with the Australian Guidelines as detailed on the Water for Life website or the NSW Health website. The appropriate web link is http://www.health.nsw.gov.au/PublicHealth/environment/water/wastewater.asp Which details that NSW Health recommends the use of the Australian Guidelines for Water Recycling: Managing Health and Environmental Risks (phase 1) (2006) for the development of recycled water schemes and in this regard, the Australian Guidelines have replaced the 1993 NSW Recycled Water Co-ordination Committee's NSW Guides for Urban and Residential Use of Reclaimed Water for use with dual reticulation schemes. The Department of Water and Energy (DWE) has also released the guideline document Management of Private Recycled Water Schemes. This guideline aligns the principles outlined in the Australian guideline to the approvals process for private recycled water schemes (requiring section 68 approvals) in NSW. The guideline replaces the NSW Health Interim Guidance for Greywater and Sewage Recycling for Mulit-Unit Dwellings and Commercial Premises (GL 2005/051 previously Circular 2004/71).
NT DHCS (2004) Information Bulletin: Greywater reuse in single domestic premises. Department of Health and Community Services, Darwin, NT, Australia.
NT DNEEA (2007) NT Waterwise Central Australia. Rebate Scheme. Terms and Conditions. DEPARTMENT OF NATURAL RESOURCES, ENVIRONMENT AND THE ARTS., Darwin, NT, Australia.
NWC (2008) Requirements for rainwater and greywater systems in Australia. Master Plumber and Mechanical Services Association of Australia for the National Water Commission and Standards Australia, Canberra, Australia.
Qld DIP (2006) Greywater. Guidelines for plumbers. Use of greywater for residential properties in Queensland sewered areas. Department of Infrastructure and Planning, Brisbane, Qld, Australia.
Qld DIP (2007) Greywater. Guidelines for councils. Use of greywater for residential properties in Queensland sewered areas. Department of Infrastructure and Planning, Brisbane, Qld, Australia.
Qld EPA (2005) Queensland Water Recycling Guidelines. Queensland Government Environmental Protection Agency, Brisbane.
Qld NRW (2007) Greywater. Home WaterWise Rebate Scheme. Queensland Government, Water, Department of Natural Resources and.
Qld NRW (2008) Waterwise Queensland: Gardening with greywater.
Queensland Government Natural Resources and Water.
Waterwise (2003) GREYWATER PLUMBING INFORMATION.
WHO (2006a) Guidelines for the safe use of wastewater, excreta and greywater. World Health Organization, Geneva, Switzerland.
WHO (2006b) Overview of greywater management Health considerations.
World Health Organisation. Regional Office for the Eastern Mediterranean, Amman, Jordan.
WSAA (2009) Occasional Paper No. 23Meeting Australia’s water challenges - Case studies in commercial and industrial water use.