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greywater reuse in sewered, single household

1. Control Do monitor plant response to greywater irrigation Native plants in particular need to be monitored when irrigated with greywater to ensure that the nutrient content of the greywater does not cause damage Control Do monitor soil response to greywater irrigation Look for changes in soil characteristics that indicate salinity problems including hard crusty soils which are a sign of sodicity The soil will benefit from an addition of gypsum when sodicity is first identified as it will help improve soil structure Control Do occasionally irrigate with drinking water to disperse salts from the soil only appropriate during periods of zero rainfall In many areas normal rainfall will flush any excess salts from greywater irrigated soils In areas of low rainfall or during periods of drought it is appropriate for a garden or lawn to be irrigated with drinking water within the limitations of any prevailing water restrictions occasionally e g six weekly to disperse salts from the soil Control Do reuse greywater by manual bucketing at several locations rather than one single point Reusing untreated bucketed greywater at several locations will prevent an accumulation of salts and other contaminates in the soil NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 45 Chemicals Control Don t divert greywater for reuse when cleaning in the laundry or bathroom or when using hair dye or othe
2. 782 L week The Table also allows an easy understanding of where greywater could be generated to meet the requirements of one or more end uses In this household the greywater generation exceeds their needs For example the volume of greywater generated by the washing machine could be used to meet the requirements for irrigation or reused in the washing machine The amount of greywater generated by the shower over a period of a week 2 551 L is sufficient to meet that required for toilet flushing and the washing machine combined 2 051 L 38 NSW DEPARTMENT OF WATER AND ENERGY APPENDIX C MANAGEMENT OF GREYWATER The reuse of greywater can potentially pose human health and environmental risks if not managed appropriately A risk assessment has been undertaken to identify the potential risks and control measures identified to manage these risks The requirement of cl 75A of the Local Government General Regulation 2005 for carrying out greywater diversion and of the Local Government Act 1993 to install and operate a greywater diversion system GDD is that a number of performance standards are achieved i the prevention of the spread of disease by micro organisms ii the prevention of the spread of foul odours iii the prevention of the contamination of water iv the prevention of degradation of soil and vegetation v the discouragement of insects and vermin vi ensuring that persons do not come into contact with untreated
3. Control Don t irrigate with greywater if premises are located on an aquifer that is used for drinking water If premises are located on a drinking water aquifer there is a risk of greywater percolating to the aquifer and contaminating the drinking water supply Council can inform owners and residents as to whether premises are located on an aquifer that is used for drinking water Control Do enrich the soil if irrigating with greywater especially if located on dune sand or shallow rocky soils Dune sand has a low potential for water storage and it is therefore not a suitable soil for irrigation with greywater Control Do reuse manual bucketed greywater by manual bucketing at several locations rather than one single point Reusing untreated bucketed greywater at several locations rather than one single point will prevent over watering 48 NSW DEPARTMENT OF WATER AND ENERGY APPENDIX D FACT SHEETS Further detailed information on greywater reuse is available in the following fact sheets Greywater Fact Sheet 1 Greywater diversion devices Dos and Don ts Greywater Fact Sheet 2 Choosing the right greywater system for your needs Greywater Fact Sheet 3 Irrigating with greywater Greywater Fact Sheet 4 Keeping your plants and soil healthy with greywater Greywater Fact Sheet 5 Maintenance of greywater treatment systems and diversion devices These fact sheets are available at www waterforlife nsw gov au NSW GUIDELINES FOR
4. Table 2 1 Per Capita In house Usage Loh and Coghlan 2003 Residential Premise Single Household Appliance L house day L person day Bath and shower 198 66 Washing machine 141 47 Sub total Greywater 339 113 Toilet 124 41 Taps includes kitchen 140 47 Total in house 603 201 Based on 3 people per house Water usage will vary according to the practice of each household Approximate percentages of water use volumes for in house use are provided in Figure 2 1 Figure 2 1 Proportion of In house Usage Available for Reuse Loh amp Coghlan 2003 ba Greywater Available for reuse covered by these guidelines Blackwater Not available for ndu din ures Washing machine reuse not covered by these guidelines EJ Greywater Not available for reuse by greywater diversion devices Toilet Bath and shower NSW DEPARTMENT OF WATER AND ENERGY 2 4 Composition of Greywater 2 4 1 Microbiological Quality The thermotolerant coliform group of bacteria are used as an indicator of microbiological quality Thermotolerant coliforms are also known as faecal coliforms and are a type of micro organism which typically grow in the intestine of warm blooded animals including humans and are shed in their millions in each gram of faeces Occurrence of faecal coliform bacteria in water indicates a risk of human illness or infection through contact with the water In general the number of faecal coliforms in greywater is l
5. Code of Practice for the Reuse of Greywater in Western Australia Water Corporation Perth Western Australia 26 NSW DEPARTMENT OF WATER AND ENERGY APPENDICES Appendix A Greywater Decision Flow Charts Appendix B Greywater Reuse Estimations Appendix C Management of Greywater Appendix D Fact Sheets APPENDIX A GREYWATER DECISION FLOW CHARTS Process Flow Chart YES Do you have an on site sewage management facility e g septic tank Greywater reuse may not be appropriate on your property YES Is your property serviced by a dual reticulation system You are not able to re use greywater on your property would like to re use greywater for Watering my garden using sub surface irrigation You will need to install a Greywater Diversion Device GO TO CHART 1 Watering my garden using surface irrigation flushing my toilet and or in my clothes washing machine You will need to install a Greywater Treatment System GO TO CHART 2 The removal of the greywater stream from the on site sewage management facility has the potential to adversely impact on the proper operation of the facility You will need to ensure that your system is able to cope with the separation of the greywater before reusing greywater at your property 28 NSW DEPARTMENT OF WATER AND ENERGY APPENDIX A GREYWATER DECISION FLOW CHARTS Chart 1 Greywater Diversion Device You are not exempt
6. Two garden beds both 2 5 m x 5 m 12 5 m in size so a total area of 25 m Number of residents 4 Potential for Reuse Irrigation potential From Table B2 with 25 m irrigation area there is potential to reuse 500 litres per reuse volume irrigation event Greywater Generation Shower and bath The shower head was installed less than 15 years ago from Table B6 shower head has a 2 Star rating From Table B7 with 4 residents the premises generates 2 352 litres per week Basin taps From Table B8 with 4 residents the premises generates 112 litres per week Washing machines Medium sized top loading washing machine From Table B9 with 4 residents the premises generates 819 litres per week Laundry taps From table B10 with 4 residents the premises generates 50 litres per week Water Balance Use Appliance Potential for Reuse L week Greywater Generated L week Irrigation 500 Shower and bath 2 352 Basin taps 112 Washing machine 819 Laundry taps 50 Total 500 3 333 Water Balance Total Greywater Generated Total Potential for Reuse Water Balance 3 333 500 2 833 L week The water balance for greywater at the premises can be determined by deducting the total greywater requirement from the total greywater generated Total Greywater Generated Total Greywater Requirement Water Balance From the previous examples and the Table 3 333 500 2 833 L week The Table also allows an easy understanding of wher
7. owners and residents with a guideline of how to best manage their reuse of greywater The list will assist owners to ensure that the reuse of greywater achieves the performance standards required for exemption from the prior approval of council Each of these control measures is explained in further detail in Appendix C of these guidelines The control measures Dos and Don ts for the GDD reduce the risks associated with reuse whilst providing a water source that has the potential to improve the health and appearance of soil and plants at the household NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 11 When undertaking diversion of greywater DO 4 DO check with the DWE web site www dwe nsw gov au to make sure your property is not registered in an area that is deemed to be environmentally sensitive 4 DO install a greywater diversion device that has a WaterMark licence previously a Plumbing Safety licence and is listed by NSW Health DO reuse diverted untreated greywater only for sub surface irrigation at least 100 mm below the surface of soil or mulch DO ensure the greywater diversion device is switched back after irrigation periods so that greywater is diverted to sewer DO undertake a water balance refer to Appendix B3 to estimate the amount of water that can be reused by the household DO select garden friendly detergents that are biodegradable and low in phosphorus s
8. 2 Why Use Greywater Recent widespread drought in Australia combined with the continued growth of cities and the need to provide for environmental flows in our river systems has resulted in increasing pressure on drinking water supplies in most large cities and many regional areas of Australia Greywater from residential premises single households is a resource and can be reused on site for garden and lawn irrigation or if treated appropriately for toilet flushing and laundry use washing machine only Substituting greywater for drinking water for these end uses will not only reduce the demand on drinking water supplies but will also reduce the amount of wastewater discharged to the environment 1 3 What Type of System Should be Used There are three ways of reusing greywater that can be implemented for sewered residential premises in NSW m greywater diversion which diverts greywater generated by a premises to the garden or lawn for use in sub surface irrigation m greywater treatment which treats greywater for other reuse such as toilet flushing washing machine and surface irrigation and m manual bucketing which involves the reuse of relatively small quantities of greywater for irrigation NSW DEPARTMENT OF WATER AND ENERGY 1 4 Structure of this Document An overview of the structure of this document is provided in order to direct readers to the section of the guidelines most appropriate to their needs Part A I
9. T reuse greywater on plants that will be eaten raw or where fruit has fallen to the ground DON T use greywater to wash paths driveways or cars DON T reuse greywater so that it flows into the streets or down stormwater drains DON T install drippers of an irrigation system within one metre of boundary lines inground pools and inground potable water tanks and buildings X X XK X XXX DON T let greywater go beyond the property boundary and cause a nuisance to neighbours NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 19 4 5 Greywater Reuse Estimations To estimate a household s greywater requirements a water balance can be undertaken to consider both the amount of greywater that has the potential to be reused and the amount of greywater that can be generated to meet the needs of the household This is important because a typical metropolitan household can potentially generate much more water than is needed for use by the household All of the information and calculations to undertake a water balance are provided in Appendix B Greywater Reuse Estimation Appendix C provides guidance for managing greywater to protect public health and the environment 4 6 Marking Labelling and Signage The marking labelling and signage of the GTS and associated sub surface irrigation system must be in accordance with the NSW Code of Practice for Plumbing and Drainage 3rd Edition 2006 Greywater ou
10. council approval to install and operate the GTS Engage a licensed plumber to install the GTS Install sub surface irrigation system to distribute greywater Fact Sheet 3 Undertake regular maintenance of the GTS Fact Sheet 5 30 NSW DEPARTMENT OF WATER AND ENERGY APPENDIX B GREYWATER REUSE ESTIMATIONS To estimate a premises greywater requirements a water balance can be undertaken to consider both the amount of greywater that has the potential to be reused and the amount of greywater that can be generated to meet the needs of the premises By undertaking a water balance owners can identify m how they can most appropriately reuse greywater on their premises m how to calculate how much greywater they have the potential to reuse m how to calculate how much greywater can be generated and m the nutrient balance of their premises It is essential that owners and residents complete the water balance when they plan to install a GDD The water for life site also provides guidance for managing greywater to protect public health and the environment B1 Potential for Reuse To determine the potential of a household to reuse greywater the end uses of greywater need to be identified There are several end uses available for greywater reuse depending on the reuse method and level of treatment Table B1 Table B1 Greywater Reuse Methods and Applications Reuse Method Greywater Reuse Application Manual bucketing e Lim
11. every one full flush AS 1172 2 1999 AS NZS 6400 2005 Table B4 can be used to estimate the amount of water used at the premises for toilet flushing and therefore the potential for reuse by replacing drinking water with greywater for toilet flushing Table B4 Potential for Greywater Reuse Toilet Flushing Potential for Reuse Toilet Flushing L week Number of residents Full Flush Dual Flush 1 308 101 2 616 202 3 924 302 4 1232 403 5 1540 504 6 1848 605 7 2156 706 32 NSW DEPARTMENT OF WATER AND ENERGY Washing Machine The method described in this section can be used for estimating the potential amount of greywater that can be used in washing machines Only greywater treated by a GTS can be used in washing machines To estimate the amount of greywater that can potentially be used by the washing machine the number of residents or the number of washes per week and the type of washing machine needs to be determined Washing machines can be front loading or top loading and can be small up to 5 5 kg medium 6 7 kg or arge over 7 5 kg In general front loading washing machines are more water efficient than top loading washing machines based on washing machines available for domestic use over the last five years The average front loading washing machines are medium in size and have a 4 Star rating under the Water Efficiency Labelling and Standards WELS Scheme The average top loading washing machines are large in
12. from Council approval You must apply to Council to reuse greywater on your property YES Are you in a registered environmentally sensitive area www dwe nsw gov au Calculate the amount of greywater you are likely to re use Appendix B1 Calculate the amount of greywater you are likely to generate Appendix B2 Complete self assessment of greywater use and generation Appendix B3 Apply to have meter with an integral dual check valve installed by your water utility Is your property serviced by a meter with an integral dual check valve YES You are not able to re use greywater on your property YES Meter with an integral dual check valve installed Select greywater diversion device Fact Sheet 2 Engage a licensed plumber to install the GDD and associated surge attenuation Install sub surface irrigation system to distribute greywater Fact Sheet 3 Undertake regular maintenance of the GDD Fact Sheet 5 NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 29 APPENDIX A GREYWATER DECISION FLOW CHARTS Chart 2 Greywater Treatment System Calculate the amount of greywater you are likely to re use Appendix B1 Calculate the amount of greywater you are likely to generate Appendix B2 Complete self assessment of greywater use and generation Appendix B3 Select greywater treatment system Fact Sheet 2 Apply for and obtain
13. greywater generating appliance is equivalent to the volume of greywater generated by an appliance The data in Table 2 1 Section 2 1 1 can be used to calculate the amount of greywater you can generate from your bathroom laundry or both depending on how many people live in the house It is appropriate to use the data in Table 2 1 However as has been previously discussed there is a high amount of variability associated with the generation of greywater The figures for residential premises water use given in Section 2 1 1 in Table 2 1 are average values and may not represent a particular premises water usage accurately To best estimate the amount of greywater generated by a household it is most accurate to determine the potential for greywater generation by the household appliances at individual residential premises NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 33 The household fixtures or appliances that can potentially be used to generate greywater are m Shower m Bath m Basin taps m Washing machine m Laundry taps Shower To estimate the amount of greywater that is generated by the shower the number of residents at the premises and the type of shower head installed in the house need to be determined Shower heads are given a rating of 1 Star to 6 Stars under the Water Efficiency Labelling and Standards WELS Scheme depending on the amount of water they use Only 1 Star to 3 Star sh
14. must be able to divert the greywater back to sewer by a tap that is easily accessible to the resident GDDs must only be turned on when the garden needs watering Leaving a GDD turned on at all times has the potential to lead to over watering Just as a resident would not leave a drinking water tap turned on watering the garden at all times the GDD should be used as a tap that is typically turned off diverted to sewer The ability to divert greywater to sewer also allows greywater that may be high in contaminants e g generated by nappy washing to be prevented from reuse Control Don t reuse greywater for irrigation during rain Diverting greywater to sewer when it is raining and after recent rainfall will help ensure that over watering which can potentially lead to an increase of the watertable height and increased salinity does not occur Control Don t over water Over watering leads to too little oxygen being supplied to a plant s roots which reduces the uptake of nutrients and encourages disease Over watering also destabilises the soil area which has the potential to make trees and shrubs more susceptible to blowing over or limb breakage If a temporary waterlogged area is identified greywater should not be reused for irrigation on that area until the water has drained Areas that are prone to flooding or waterlogging during wet weather are likely to become waterlogged during irrigation with greywater leading to runoff and percolati
15. place are sufficient to control the identified hazards and to improve such measures or add new measures if necessary The objective of the risk management approach is to identify and manage the risks associated with greywater reuse ensuring that sufficient barriers or control points are in place to minimise risks and meeting the performance standards NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 39 C2 Hazard Identification The hazard identification step of the risk management process considers potential biological chemical and physical hazards that could be associated with the reuse of greywater to residential premises and that could potentially affect human or environmental health The objective is to identify the hazard the source the potential hazardous event that may cause contamination or another impact and the receiving environment or receptor The following hazards were identified for greywater reuse in residential premises m Biological Pathogens such as bacteria viruses protozoa helminths m Chemical Nutrients Salts Chemicals m Physical Physical contaminants Water volume Sources of potential hazards include m Washing machine pathogens nutrients salts chemicals water volume physical contaminants m Washing detergents especially during the wash cycle nutrients salts m Shower and hand basin pathogens salts chemicals water volume physica
16. sewage or wastewater in their ordinary activities on the premises concerned vii the minimisation of any adverse impacts on the amenity of the premises concerned and surrounding lands The management controls identified in this section when implemented will assist owners to meet the performance standards The management controls also include practices that are required in the NSW Code of Practice Plumbing and Drainage 3rd Edition 2006 for carrying out greywater diversion and installing and operating a GTS By following the management controls identified in this guideline greywater diversion may be carried out without the approval of council provided the conditions described in Section 3 2 are met Greywater treatment systems continue to require prior approval from council C1 Risk Management Approach A risk management approach involves identifying and managing risks in a proactive way rather than simply reacting when problems arise The application of the approach can be considered in three steps 1 Hazard Identification Identify all the hazards in the greywater that could potentially affect human or environmental health i e what might happen and how 2 Risk Assessment Assess the risk from each hazard by estimating the likelihood that the event will occur and the consequence if it did i e how likely is it that something will haopen and how serious will it be if it does 3 Controls Ensure that preventive measures in
17. size and have a 2 Star rating under the Water Efficiency Labelling and Standards WELS Scheme The size of the washing machine can be found in the manufacturer s user manual or written on the machine itself Alternatively owners and residents can assume that a front loading washing machine is medium in size and a top loading washing machine is large Table B5 can be used to estimate the amount of water used by a washing machine per week The number of residents or the number of washes per week can be matched with the type of washing machine to give the estimated amount of greywater that can be reused by the washing machine Table B5 Potential for Greywater Reuse Washing Machines Potential for Reuse Washing Machine L week Number of Number of ches per Front Loading Washing Machine Top Loading Washing Machine residents week Small Medium Large Small Medium Large up to 5 5 kg 6 7 kg over 7 5kg up to 5 5 kg 6 7 kg over 7 5 kg 1 2 103 133 164 210 273 336 2 3 154 200 246 315 410 504 3 4 205 267 328 420 546 672 4 6 308 400 492 630 819 1008 5 7 359 466 574 735 956 1176 6 8 410 533 656 840 1092 1344 7 9 461 600 738 945 1229 1512 Assumptions Top loading average machine is large over 7 5 kg with a 2 Star WELS rating Front loading average machine is medium 6 7 kg with a 4 Star WELS rating Sources AS NZS 6400 2005 Choice Magazine 2003 B2 Greywater Generation The potential water usage volume for a
18. villas and multi unit dwellings is not permitted This is due to the fact that other residences will not have been exposed to the pathogens through personal contact therefore increasing the risk of spreading disease through the community A town house occupant using only that residence greywater on the garden within the premises is permitted Use on common property gardens is not permitted Appendix A outlines the process for choosing and installing a greywater diversion device 3 2 Conditions of Approval The Local Government General Regulation 2005 under the Local Government Act 1993 requires prior council approval of greywater diversion However under Clause 75A of the Regulation greywater diversion at residential premises may be carried out without the prior approval of the council if m it is carried out in accordance with the Plumbing and Drainage Code of Practice m asewage management facility is not installed on the premises concerned and m certain performance standards related to health and the environment are met see Appendix C To obtain exemption from obtaining council approval the following conditions should also be satisfied m the proposed site for installation is not located in an area registered as environmentally sensitive Areas registered as environmentally sensitive are listed on the Department of Water and Energy web site www dwe nsw gov au 10 NSW DEPARTMENT OF WATER AND ENERGY m wastewater is not diverted f
19. 06 Install sub surface irrigation system to distribute greywater J Notify the local water utility that a GDD has been installed at the property Jf Undertake regular maintenance of the GDD in accordance with the manufacturer s recommendations and these S guidelines 3 10 Offences and Penalties There is an onus of responsibility on the owner of residential premises where a greywater diversion device GDD is installed to ensure that the GDD is maintained and does not compromise public health or the environment The best practice management control measures identified in this guideline provide guidance on how to maintain and operate a GDD correctly to protect public health and the environment If the owners of premises comply in full with these guidelines then they are exempt from council approval If a person carries out the activity of greywater diversion without council approval and does not comply with the requirements in the Regulation the NSW Code of Practice and these guidelines the exemption from approval is invalid Under s 626 3 of the Local Government Act 1993 the maximum penalty for carrying out an activity without prior council approval is 2200 or council can issue an on the spot fine of 220 If a neighbour or member of the public reports a nuisance or greywater crossing boundary lines with the potential to cause a public health or environmental impact council has the ability to follow up the complaint and issue fines or di
20. A Greywater Decision Flow Charts Appendix B Greywater Reuse Estimations B1 Potential for Reuse B2 Greywater Generation B3 Water Balance Appendix C Management of Greywater C1 Risk Management Approach C2 Hazard Identification C3 Risk Assessment C4 Best Practice Management Controls Pathogens Nutrients Salts Chemicals Physical Contaminants Water Volume Appendix D Fact Sheets 2 NSW DEPARTMENT OF WATER AND ENERGY 17 17 17 17 17 17 20 20 20 20 21 21 22 22 22 22 24 26 26 28 31 31 33 36 39 39 40 40 42 42 44 45 46 46 47 49 INTRODUCTION Section 1 Introduction Section 2 Greywater Characteristics 4 1 INTRODUCTION 1 1 Overview These guidelines provide direction on the use of greywater diversion devices GDDs in single households and have been developed to specify the conditions for exemption from prior approval by councils for greywater diversion The Local Government General Amendment Domestic Greywater Diversion Regulation 2006 allows an exemption from prior approval by councils if certain practices are implemented and conditions are met The main purpose of these guidelines is to provide guidance on meeting those practices and conditions Part B of this document The secondary purpose of the guidelines is to provide additional advisory information to the owners and or occupiers of sewered residential premises on greywater treatment systems and manual bucketing of g
21. ACT Government 2004 Greywater Use Guidelines for residential properties in Canberra ACT Government Canberra Australia Australian Standards AS 1319 1994 Safety signs for the occupational environment Australian Standards AS 2700 AS 2700 1996 Colour Standards for general purposes Australian Standards AS NZS 3500 1 2003 Plumbing and drainage Water services Committee on Uniformity of Plumbing and Drainage Regulation in NSW 2006 New South Wales Code of Practice Plumbing and Drainage 3rd Edition Department of Energy Utilities and Sustainability Sydney New South Wales Local Government Act 1993 NSW Local Government General Regulation 2005 NSW NSW Government 1998 Environment amp Health Protection Guidelines On site and Decentralised Sewage Management NSW Government Sydney Australia Patterson R A 2006 Consideration of soil sodicity when assessing land application of wastewater Septic Safe Technical Sheet 01 7 Department of Local Government and Lanfax Laboratories Armidale Australia Protection of the Environment Operations Act 1997 NSW SAI Global Assurance Services Australian Technical Specification 5200 460 2005 Shaw R J 1999 Soil Salinity Electrical Conductivity and Chloride in Soil Analysis an interpretation manual Edited by Peverill K I Sparrow L A and Reuter D J CSIRO Canberra Australia Water Corporation Department of Environment WA and Department of Health WA 2005
22. GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 49 EO Life NSW GOVERNMENT 5 LL_DEW083_0508
23. NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES MAY 2008 Waterg for Life NSW GOVERNMENT ACKNOWLEDGEMENTS This guideline was prepared with consideration of feedback from a wide range of NSW government departments local councils industry and other relevant stakeholders who provided comment during public consultation on the draft guideline A number of information sources were referenced during the development of the guideline A comprehensive list is appended to this document Disclaimer While the Department of Water and Energy has taken due care in the preparation of these guidelines including the appendices it accepts no liability for any errors or omissions nor for any use of the guidelines by any person NSW Government Department of Water amp Energy Department of Energy Utilities and Sustainability Level 17 227 Elizabeth Street SYDNEY NSW 2000 GPO Box 3889 SYDNEY NSW 2001 Tel 02 8281 7777 Fax 02 8281 7799 Web www dwe nsw gov au Email information dwe nsw gov au State of NSW through the Department of Water and Energy 2008 ISBN number 978 0 7347 5940 5 DWE 08_092 May 2008 This work may be freely reproduced and distributed for most purposes however some restrictions apply Contact the Department of Water and Energy for copyright information EMS ENVIRONMENTAL wusoerssas Printed on FSC mixed source paper containing 80 recycled
24. ace irrigation at a depth of 100 mm or more below the surface Distribution pipes and fittings must be at least one metre from a boundary and delivery pipes will generally need to be underground The sub surface irrigation should be installed in such a manner that it will not discharge into any watercourse or cause run off to neighbouring properties The irrigation system connected to the GDD does not require installation by a licensed plumber but must follow the manufacturer s recommendations or design where relevant and must meet the performance standards in Clause 75A of the Regulation reproduced in Appendix C of these guidelines Irrigation systems shall not be connected to both the mains water and the greywater diversion supply Additional information on recommended sub surface irrigation design maintenance and management can be found in the greywater fact sheets listed in Appendix D 3 7 Marking Labelling and Signage In accordance with the NSW Code of Practice for Plumbing and Drainage 3rd Edition 2006 the GDD and associated sub surface irrigation system must be marked labelled and signed External connections shall have signs that are marked WARNING DO NOT DRINK in accordance with the Australian Standard AS 1319 All pipes or pipe sleeves and identification tapes including those on pressurised irrigation systems shall be coloured purple as per the Australian Standard AS 2700 and marked with the following in accordance wi
25. an one dwelling GLOSSARY OF TERMS continued reticulation A network of water pipes which delivers water supply to customers risk The likelinood of a hazard causing harm in exposed populations in a specified timeframe including the magnitude of that harm EPHC NRMMC 2005 salinity irrigation salinity The increasing build up of salts in irrigated soils It results from raised water table levels that bring soil salts into the upper levels of the soil profile sewage management facility A human waste storage facility or a waste treatment device intended to process sewage Also includes a drain connected to such a facility or device As defined in Section 68A of the Local Government Act 1993 sub surface irrigation Irrigation at a depth of at least 100 mm below surface level of soil or mulch surface irrigation Water applied to the ground surface from above surface level surface water All water naturally open to the atmosphere e g rivers streams lakes and reservoirs surge attenuation A tank or similar to cope with sudden influxes of greywater e g from a washing machine cycle for distribution to a land application system thermotolerant coliforms An indicator of microbiological quality A type of micro organism which typically grows in the intestine of warm blooded animals including humans and are shed in their millions in each gram of faeces wastewater Water that has been contaminated by some activity Includes greywater
26. and sewage NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 25 REFERENCES Christova Boal D Eden R E and McFarlane S 1996 An investigation into greywater use for urban residential properties Desalination 106 1996 391 397 DEC NSW 2004 Environmental Guidelines Use of wastewater by irrigation NSW Department of Environment and Conservation Sydney Australia Jeppesen B and Solley D 1994 Domestic greywater reuse Overseas practice and its applicability to Australia Research Report No 73 Urban Water Research Association of Australia Brisbane Australia Loh M and Coghlan P 2003 Domestic water use study In Perth Western Australia 1998 2001 Water Corporation Perth Australia NSW Health 2005 Domestic Greywater Treatment Systems Accreditation Guidelines February 2005 NSW Department of Health Sydney Australia NSW Health 2000 Greywater reuse in sewered single domestic premises April 2000 NSW Department of Health Sydney Australia Patterson R A 2006 Consideration of soil sodicity when assessing land application of wastewater or greywater Septic Safe Environmental Health and Protection Guidelines Technical Sheet Reference 01 7 Department of Local Government and Lanfax Laboratories Sydney Water Corporation 2005 Water Conservation amp Recycling Implementation Report 2004 2005 Sydney Water Corporation Sydney Australia BIBLIOGRAPHY
27. ants such as hair lint dirt and sand from causing blockages in the irrigation system Control Do use irrigation drippers with large openings A greywater irrigation system that has drippers with large openings will allow solids that have not been removed by the screening of solids to pass through the system without causing blockages and will prevent the pooling of water Control Do ensure that regular maintenance is undertaken Regular maintenance of a greywater system including cleaning the filters of a diversion device system or appropriately maintaining a GTS will ensure that the greywater systems are working effectively and will minimise any problems that may otherwise result from leakages blockages or other technical problems Control Do reuse greywater by manual bucketing at several locations rather than one single point Reusing untreated bucketed greywater at several locations will prevent an accumulation of physical and other contaminants in the soil Control Do consider applying a soil rewetting agent every six months Soil irrigated with greywater will benefit from an application of a soil rewetting agent every six months to prevent and manage water repellent soils 46 NSW DEPARTMENT OF WATER AND ENERGY Control Do enrich the soil if irrigating with greywater especially if located on dune sand or shallow rocky soils Enriching the soil with organic matter and mulch will improve the potential water storage of a soil T
28. at has been accredited by NSW Health DO reuse treated greywater from a GTS only for irrigation including surface irrigation toilet flushing and washing machine use DO undertake a water balance before installing a GTS to calculate the amount of water that can be reused by the household DO select garden friendly detergents that are biodegradable and low in phosphorus sodium boron and chloride DO select washing detergents that are low in salt consider using a powder concentrate or a liquid washing detergent DO monitor plant and soil response to greywater irrigation DO occasionally irrigate with drinking water to disperse salts from the soil only appropriate during extended periods of zero rainfall DO consider applying a soil rewetting agent every six months DO ensure that regular maintenance of the greywater system is undertaken SININ ONIN ONY ON ONONEN DO mark and label all pipes and use signs to indicate greywater reuse see section 4 6 When reusing greywater treated by a greywater treatment system DON T x DON T irrigate with greywater during rain x DON T reuse greywater generated by cleaning in the laundry or bathroom or when using hair dye or other chemicals DON T reuse greywater generated by washing rags used for painting or for maintaining machinery DON T reuse greywater to top up rainwater tanks or swimming pools DON T over water DON
29. be a low risk activity for the following reasons m Manual bucketing reuses low volumes of greywater Accordingly only low quantities of contaminants will be applied to the soil and there is a limited ability for runoff to neighbouring properties or waterways m Itis unlikely that manual bucketing will occur during wet weather reducing the risk of over watering or runoff 5 2 Conditions of Approval Manual bucketing for residential premises in sewered areas of NSW does not require prior approval from council 5 3 Using Greywater Safely It is important that manual bucketing is undertaken sensibly to ensure that public health and the environment are protected The following best practice management control measures presented in a list of Dos and Don ts have been compiled to provide owners and residents with a guideline of how to best manage their reuse of greywater by manual bucketing Each of these control measures is explained in further detail in Appendix C of these Guidelines The best practice management control measures Dos and Don ts for manual bucketing are a necessity as they reduce the risks associated with reuse whilst providing a water source that has the potential to improve the health and appearance of soil and plants When undertaking manual bucketing of greywater DO DO be careful lifting and carrying buckets of greywater particularly over slippery surfaces and on stairs or steps DO select garden friendly deter
30. e many times more soluble than calcium or magnesium salts and soil sodicity soil degradation due to sodium salts presents particular problems to soil and vegetation including soil permeability and plant growth Patterson 2006 The salts originate from washing detergents which vary in their salt content Reducing the quantity of salts particularly sodium is the most effective method to reduce the risk to soil and vegetation due to salts and especially soil sodicity Generally powdered detergents contain the most salt as it is used in washing powders as filler Concentrated powders generally contain less salt than normal powdered detergents and liquid detergents contain the least salt of all washing detergents Table 2 3 Table 2 3 Sodium Adsorption Ratio Patterson 2006 Sodium Adsorption Ratio SAR Greywater Type Laundry powder detergents 9 2 52 1 Laundry Ke i i liquid detergents The sodium adsorption ratio SAR measures the relationship of the concentration of sodium cations positive ions in the water compared to the concentration of other cations in the water Water with a SAR of greater than 6 is likely to raise the risk of sodicity in non sodic soils whilst a SAR of less than 3 may lower that risk in sodic soils Table 2 3 clearly shows that if liquid detergents are used greywater has a SAR with a maximum of 4 well within the acceptable SAR Thus using liquid detergents instead of powder detergent
31. e Does Greywater Come From Greywater is generated by every residential household that is occupied and can be reused to provide a reliable source of water for those uses that do not require drinking water including irrigation toilet flushing and washing machine use The characteristics of greywater produced by a household will vary according to the number age lifestyle health status and water usage patterns of the occupants There are essentially two different greywater streams 1 Bathroom greywater bath basin and shower contributes about 59 per cent of the total usable greywater volume in a typical household Loh amp Coghlan 2003 Bathroom greywater can be contaminated with hair soaps shampoos hair dyes toothpaste lint nutrients body fats oils and cleaning products It may also contain some faecal contamination and the associated pathogens through body washing NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 5 6 2 Laundry greywater contributes about 41 per cent of total usable greywater volume in a typical household Loh 8 Coghlan 2003 Wastewater from the laundry varies in quality from wash water to rinse water to second rinse water Laundry greywater can be contaminated with lint oils greases laundry detergents chemicals soaps nutrients and other compounds It may also contain some faecal contamination and the associated pathogens through washing contamina
32. e greywater could be generated to meet the requirements of one or more end uses In this household the total greywater generation is well in excess of the needs For example the volume of greywater generated by the washing machine could be used to meet the requirements for irrigation over one week However considering the shower generating 2 833 litres per week of greywater or the equivalent of 405 litres per day the irrigation event demand could be met in one day of shower greywater reuse There is no need in this example to connect both the shower and the washing machine to a GDD It is likely that the decision regarding which appliance to fit the GDD to would be based on which appliance allowed for the easiest access NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 37 Example Water Balance Greywater Treatment System The Jones family of four live in sewered residential premises and want to use greywater for toilet flushing their washing machine and irrigating the gardens in their backyard The Jones family can use a greywater treatment system GTS to treat greywater generated at the premises for toilet flushing washing machine reuse and surface irrigation of their gardens The Jones family must receive approval to install and operate their GTS from their local council and the GTS must be accredited by NSW Health Garden size Two garden beds both 2 5 m x 5 m 12 5 m in size so a total area o
33. er Front Loading Washing Machine Top Loading Washing Machine nesicenits week Small Medium Large Small Medium Large up to 5 5 kg 6 7 kg over 7 5kg up to 5 5 kg 6 7 kg over 7 5 kg 1 2 103 133 164 210 273 336 2 3 154 200 246 315 410 504 3 4 205 267 328 420 546 672 4 6 308 400 492 630 819 1008 5 7 359 466 574 735 956 1176 6 8 410 533 656 840 1092 1344 7 9 461 600 738 945 1229 1512 Assumptions Top loading average machine is large over 7 5 kg with a 2 Star WELS rating Front loading average machine is medium 6 7 kg with a 4 Star WELS rating Sources AS NZS 6400 2005 Choice Magazine 2003 Laundry Taps Laundry taps are generally used for soaking clothes and hand washing delicates Water that has been used to wash nappies or soiled clothing must not be diverted as greywater due to the high pathogen load of the wastewater generated It is estimated that a residential premises with three or less residents uses the equivalent of half a laundry tub of water per week an average laundry tub has a capacity full to the brim of 50 litres and a residential premises with four or more residents uses the equivalent of one full laundry tub of water per week The amount of greywater generated by premises from laundry taps has been estimated in Table B10 Table B10 Greywater Generation Laundry Taps Number of Residents Greywater Generation Basin Taps L week 3 or less 25 4 or more 50 Assumptions An average lau
34. etermined It is appropriate to reuse washing machine wastewater as greywater in both diversion systems and greywater treatment Washing machines can be front loading or top loading and can be small up to 5 5 kg medium 6 7 kg or large over 7 5 kg In general front loading washing machines are more water efficient than top loading washing machines based on washing machines available for domestic use over the last five years Choice Magazine 2003 The average front loading washing machines are medium in size and have a 4 Star rating under the Water Efficiency Labelling and Standards WELS Scheme The average top loading washing machines are large in size and have a 2 Star rating under the WELS Scheme The size of the washing machine can be found in the manufacturer s user manual or written on the machine itself alternatively owners and residents can assume that a front loading washing machine is medium in size and a top loading washing machine is large Table B9 can be used to estimate the amount of water generated by a washing machine per week The number of residents or the number of washes per week can be matched with the type of washing machine to give the estimated greywater generated by the washing machine NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 35 Table B9 Greywater Generation Washing Machines Greywater Generation Washing Machine L week Number of Number of washes p
35. f 25 m Number of residents 4 Potential for Reuse Irrigation potential From Table B2 with 25 m irrigation area there is potential to reuse volume reuse 500 litres per irrigation event Toilet flushing The Jones family have a full flush toilet from Table B4 potential reuse volume the toilet has the potential to reuse 1 232 litres per week Greywater Generation Shower and bath The shower head was installed less than 15 years ago from Table B6 shower head has a 2 Star rating From Table B7 with 4 residents generates 2 352 litres per week Basin taps From Table B8 with 4 residents generates 112 litres per week Washing machines Medium sized top loading washing machine From Table B9 with 4 residents generates 819 litres per week Laundry taps From Table B10 with 4 residents generates 50 litres per week Water Balance Use Appliance Potential for Reuse L week Greywater Generated L week Irrigation 500 Toilet Flushing 1 232 Shower and bath 2 352 Basin taps 112 Washing machine 819 819 Laundry taps 50 Total 2 551 3 333 Water Balance Total Greywater Generated Total Potential for Reuse Water Balance 3 333 2551 782 L week The water balance for greywater at the premises can be determined by deducting the total greywater requirement from the total greywater generated Total Greywater Generated Total Greywater Requirement Water Balance From the previous examples and the Table 3 333 2 551
36. fibre ISO 14001 PART A INTRODUCTION 1 Introduction 1 1 Overview 1 2 Why Use Greywater 1 3 What Type of System Should be Used 1 4 Structure of this Document 2 Greywater Characteristics 2 1 Definitions 2 2 Where Does Greywater Come From 2 3 Water Usage Volumes 2 4 Composition of Greywater 2 4 1 Microbiological Quality 2 4 2 Chemical and Physical Quality Nutrients Salts o N N N 4 O U UT U u A R A R w PART B GREYWATER DIVERSION DEVICES m o 3 Greywater Diversion Devices 3 1 Overview 3 2 Conditions of Approval 3 3 Using Greywater Safely w 3 4 Greywater Reuse Estimations R 3 5 Choosing a Greywater Diversion Device R 3 6 Sub surface Irrigation R 3 7 Marking Labelling and Signage vI 3 8 Maintenance oa 3 9 Responsibilities on 3 10 Offences and Penalties NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 1 PART C ADVISORY INFORMATION ON THE REUSE OF GREYWATER 4 Greywater Treatment Systems 4 1 Overview 4 2 Accreditation 4 3 Approvals 4 4 Using Greywater Safely 4 5 Greywater Reuse Estimations 4 6 Marking Labelling and Signage 4 7 Irrigation 4 8 Maintenance 4 9 Responsibilities 4 10 Offences and Penalties 5 Manual Bucketing of Greywater 5 1 Overview 5 2 Conditions of Approval 5 3 Using Greywater Safely Glossary of Terms References Bibliography Appendix
37. friendly detergents that are biodegradable and low in sodium boron and chloride Minimising the salt content sodium boron chloride of greywater is important to reduce any risks due to soil salinity Control Do select liquid washing detergents as they are comparatively low in salts Minimising the salt content low sodium and chloride of greywater is important to reduce any risks due to soil salinity It is included in washing powders as filler Liquids generally have the lowest salt content of all types of washing detergents and as such should be used at any premises that carry out greywater reuse for irrigation Control Don t reuse greywater for irrigation during rain Diverting greywater intended for irrigation to sewer when it is raining and after recent rainfall will help ensure that over watering which can potentially lead to an increase of the watertable height and increased salinity does not occur Control Do undertake a water balance before installing a greywater reuse system to calculate the amount of water that can be reused by the household By understanding how much water can be reused by the household the homeowner and the residents can ensure that over watering which can potentially lead to an increase of the watertable height does not occur Greywater should be diverted to sewer when it can not be appropriately used within the premises It must be noted that greywater reuse should not be considered as a form of disposal
38. g recommended dosage rates over a one year period provided by manufacturers of typical lawn fertilisers Table 2 2 Nutrient Application Resulting from Greywater Reuse Bathroom Greywater Laundry Greywater Fertiliser Nutrient Range grams year m2 Range grams year m2 Average grams year m2 Total Nitrogen N 3 22 24 0 0 7 48 0 17 6 Total Phosphorus P 0 08 2 16 0 04 50 4 11 3 Source Based on the composition of five readily available lawn fertilisers Brunnings Hortico Munns Shirley s and Yates and greywater composition data from Christova Boal et al 1996 NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 7 8 Excessive nutrient loads should be avoided to prevent damage to soil plants groundwater and off site waterways However it is apparent from Table 2 2 that the typical nutrient loads that are applied to the soil by irrigating with greywater are similar to those that are applied by following the directions on common fertiliser packages The upper limits of ranges can be managed by the selection of appropriate laundry detergents and similar products that are low in nitrogen and phosphorus The reuse of greywater therefore has the potential to significantly reduce the need for fertiliser application on gardens and lawns The application of nutrients through the irrigation process is also preferred as the nutrients will be applied more gradually and wil
39. g the risk to human health and the environment Best practice management control measures have been identified to minimise the risks associated with greywater reuse for residential premises It is mandatory that all of the management measures identified here are undertaken by the owners and residents to ensure that the reuse of greywater occurs in a responsible and sustainable manner Measures are listed under the hazards they relate to along with an explanation of the reasoning behind the control and a symbol indicating the reuse method that the control is specific to m greywater diversion device GDD m greywater treatment system GTS m manual bucketing Any conditions of approval imposed on a GTS by council or NSW Health must be implemented in preference to the controls recommended in these guidelines Fact sheets have been produced to accompany the guideline to provide easy to understand guidance to homeowners and residents regarding the appropriate management strategies to implement Pathogens Control Don t reuse toilet or kitchen wastewater Wastewater from toilets urinals or bidets is contaminated with pathogens and is not greywater and must not be reused as greywater on site Kitchen wastewater is heavily contaminated with oils and grease and is inappropriate for greywater reuse Control Do implement a greywater diversion device that has a WaterMark licence previously a Plumbing Safety licence and is registered by NSW Heal
40. gents that are biodegradable and low in phosphorus sodium boron and chloride DO select washing detergents that are low in salt consider using a powder concentrate or a liquid washing detergent DO reuse greywater in the garden in several locations DO monitor plant and soil response to greywater irrigation DO consider applying a soil rewetting agent every six months NANANANSANSANAN DO wash your hands after reusing greywater 22 NSW DEPARTMENT OF WATER AND ENERGY When undertaking manual bucketing of greywater DON T DON T reuse toilet or kitchen wastewater DON T reuse greywater for irrigation during rain DON T apply greywater in areas that are readily accessible to children people with a low immune system or pets DON T reuse greywater generated from the washing of nappies or soiled clothing DON T reuse greywater when a resident is sick e g has diarrhoea DON T reuse greywater generated by cleaning in the laundry or bathroom or when using hair dye or other chemicals DON T reuse greywater generated by washing rags used for painting or for maintaining machinery and vehicles DON T reuse greywater to top up rainwater tanks or swimming pools DON T store untreated greywater DON T over water DON T reuse greywater on plants that will be eaten raw or where fruit has fallen to the ground and could be eaten DON T use greywater to wash paths driveways o
41. his is particularly important for dune sand and shallow rocky soils which have a low potential for water storage Water Volume Control Do undertake a water balance before installing a greywater reuse system to calculate the amount of water that can be reused by the household By understanding how much water can be reused by the household the homeowner and the residents can ensure that over watering which can potentially lead to water logging of soils odours damage to the health of soils and plants and an increase of the watertable height does not occur Greywater should be diverted to sewer when it can not be appropriately used within the premises It must be noted that greywater reuse should not be considered as a form of disposal Control Don t install any component of an irrigation system within one metre of boundary lines inground pools inground potable water tanks and buildings This provides a buffer to neighbouring properties and the footings of buildings preventing runoff to neighbouring properties and damage to buildings Control Don t leave a greywater diversion device GDD on all the time Treat it like a garden tap and only reuse greywater when your garden needs watering Greywater is for reuse not disposal Greywater is a resource that can be used to replace drinking water for many final uses It s important to recognize that greywater is for reuse not disposal The greywater diversion device installed at a household
42. hould be diverted to sewer when a resident has diarrhoea or is ill to prevent pathogens from contaminating greywater minimising exposure Control Don t reuse greywater from the washing of nappies or soiled clothing Greywater should be diverted to sewer when nappies clothes or blankets contaminated with faecal matter or vomit are washed Control Don t store untreated greywater To prevent any increase in pathogen levels prior to reuse and to discourage insects vermin and odour generation untreated greywater must not be stored in any way other than temporarily in a bucket or similar container Control Don t reuse manual bucketed greywater in areas that are readily accessible to children and pets Manual bucketed greywater is untreated and should not be applied to areas that are readily accessible to children and pets to prevent exposure to pathogens and minimise the risk to health Control Don t reuse untreated greywater on plants that will be eaten raw or where fruit has fallen to the ground and could be eaten To prevent the ingestion of pathogens greywater should not be diverted and used for sub surface irrigation of food plants that have their edible parts underground or touching the ground In addition any fruit that has fallen to the ground in an untreated greywater irrigation area should not be consumed Control Don t irrigate with greywater if the premises is located on an aquifer that is used for drinking water If the prem
43. inal or bidet The installation and operation of a method for diverting untreated greywater generated by a household to sub surface irrigation of a garden or lawn at that same premises A device that diverts greywater generated by a household for sub surface irrigation reuse A system that collects treats and disinfects greywater generated by a household for reuse for one or more of the following end uses toilet and urinal flushing washing machine and surface or sub surface irrigation Water beneath the surface held in or moving through saturated layers of soil sediment or rock The organisation agency or company that has responsibility and authority for treating and or supplying water and wastewater services to a local government area Water suitable for purposes other than drinking water use Allows the temporary containment of greywater to be released to an irrigation system at a constant rate via gravity or pump Methods of non storage surge attenuation include a non storage surge attenuation tank attenuation incorporated into the GDD system itself or a mulch pit Chemical elements essential for sustained plant or animal growth The major nutrients essential for plant growth are nitrogen phosphorus and potassium Organism that is capable of causing disease in humans and animals The descent of water through the soil A single household in a sewered residential area does not include a premises comprising more th
44. ises is located on a drinking water aquifer there is a risk of greywater percolating to the aquifer and contaminating the drinking water supply Council can inform owners and residents as to whether premises are located on an aquifer that is used for drinking water Control Do mark and label all pipes and use signs to indicate greywater reuse By ensuring that the greywater system is appropriately signed the likelihood of cross connections human contact or inappropriate use is minimised Control Do ensure that regular maintenance is undertaken Regular maintenance of a greywater system will ensure that the system is working effectively and will minimise any problems that may otherwise result from leakages blockages or other technical problems Maintenance of diversion devices requires weekly cleaning of the coarse filter attached to the diversion device Any wash water from the cleaning of a GDD should be disposed of directly to the sewer NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 43 Maintenance of greywater treatment systems GTSs should be undertaken in accordance with the maintenance manual provided by the GTS manufacturer Maintenance of the GTS will also include annual testing of the backflow prevention device by an authorised and accredited person Following the testing a Backflow Prevention Inspection Testing and Maintenance Report and prescribed fee shall be provided to the local a
45. ited irrigation Greywater diversion device GDD e Sub surface irrigation at least 100 mm below surface Greywater treatment system GTS e Surface or sub surface irrigation e Toilet flushing e Washing machine The potential amount of greywater that can be reused for residential premises can be estimated by considering the irrigation potential of the premises Irrigation The method described in this section can be used for estimating the potential amount of greywater that can be used for sub surface irrigation GDD or GTS greywater or surface irrigation greywater treated by a GTS only To estimate the amount of greywater that can be reused for irrigation a number of factors need to be considered including the soil irrigation rate size of the area to be irrigated and seasonal variations in irrigation requirements The irrigation volume is the amount of water that the soil can absorb per square metre of garden or lawn that will be irrigated The irrigation volume adopted for NSW is 20 L m for each event equivalent to 20 mm m of rainfall The frequency of an irrigation volume is dependant on the soil s capacity to hold water this will be considered later in the estimations The sub surface irrigation area can be calculated by determining the total size of all of the garden beds or lawn area that will be served by the irrigation system The sub surface irrigation area can then be multiplied with the irrigation volume to determine the
46. l contaminants m Bleaches chemicals m Cleaning chemicals chemicals physical contaminants m Paints chemicals m Wet weather periods of high rainfall water volume The receiving environment and receptors for a residential premises environment include humans animals pets native and feral animals plants soil and the irrigation or other distribution system The receiving environment may also extend to beyond the boundaries of the residential premises generating greywater and to neighbouring properties c3 Risk Assessment Risk is the product of the likelihood of a hazard occurring and the consequence of that hazard occurring A risk assessment was carried out for greywater reuse at residential premises An explanation of the risk events associated with each of the hazards identified is discussed below Pathogens The health status of residents of premises is usually reflected in the wastewater produced However residents enjoying good health will still excrete micro organisms which are part of the normal flora of the gut Greywater may be contaminated with disease causing micro organisms pathogens such as bacteria viruses protozoa and helminths It is these pathogens that present a health concern associated with greywater reuse People vary in their susceptibility to disease The young elderly and immuno compromised are more susceptible than the general population 40 NSW DEPARTMENT OF WATER AND ENERGY Disease trans
47. l reduce the risk of nutrients being washed away during rain events The variability in the nutrient loadings is influenced by the use of different washing detergents personal hygiene products soaps shampoos and cleaning agents The amount of nutrients in the products being used by the household has a direct relationship with the amount of nutrients that are present in the greywater when it is reused for irrigation By managing the type and amount of washing detergents personal hygiene products and cleaning agents that are used the amount of nutrients in greywater can be managed Further information regarding the management of nutrients in greywater and managing vegetation that is irrigated by greywater can be found in Appendix C and in the Greywater Fact Sheets Salts Salts in greywater originate from washing detergents and are commonly in the form of sodium magnesium and calcium compounds Patterson 2006 The application of greywater to land introduces to the soil quantities of many salts that cannot be drained from the root zone under normal rainfall Increases in salt concentration in soil will depend upon the unique combination of soil type greywater composition and drainage Patterson 2006 The major risks of salts contained in greywater are the accumulation of salts in the soil structure leading to a loss of soil permeability ability to absorb water which can cause degradation to vegetation Sodium salts are always very solubl
48. led to ensure that council has approved the installation and the operation of the system and that it is maintained and does not compromise public health or the environment Failure to obtain approval from council for the installation of a greywater treatment system as well as failure to obtain approval to operate a greywater treatment system are offences under section 626 3 of the Local Government Act 1993 The maximum penalty is 2200 Councils can issue an on the spot fine of 330 for operating a greywater treatment system without approval Failure to comply with the conditions of approval issued by council is also an offence under section 627 3 of the Local Government Act 1993 The maximum penalty is 2200 Councils can issue an on the spot fine of 330 for failing to comply with the conditions of approval for operating a greywater treatment system NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 21 5 MANUAL BUCKETING OF GREYWATER This section outlines the conditions of approval and the Dos and Don ts for manual bucketing of greywater at residential premises in sewered areas of NSW 5 1 Overview Manually irrigating with greywater using a bucket e g collecting shower and laundry water for reuse can reuse small quantities of greywater potentially saving drinking water Bucketed greywater can be reused for irrigation of gardens lawns and outdoor pot plants Manual bucketing is considered to
49. lumbing and Drainage 3rd Edition 2006 The plumber must ensure that controls to prevent the incidence of cross connection are implemented and that the local water utility is notified in writing that a diversion device is in place at the household Written confirmation shall be in the form of a certificate of compliance and as completed plans e g an amended sewer service diagram or other documentation as required by the local water utility Where a GDD is to be installed at a residence the property owner should check with their local water utility prior to installation that their property is serviced by a meter with an integral dual check valve to ensure backflow protection of the water supply The sub surface irrigation system connected to the GDD does not require installation by a licensed plumber but must meet the requirements of Section 3 6 and 3 7 and the performance standards in Clause 75A of the Local Government Regulation reproduced in Appendix C of this Guideline Also where relevant the installation of the sub surface irrigation system must follow the manufacturer s recommendations or design A GDD unlike a GTS does not require approval to operate the system 3 3 Using Greywater Safely It is important that greywater diversion is undertaken sensibly to ensure that public health and the environment are protected at all times The control measures presented in a list of Dos and Don ts have been compiled to provide
50. mission is principally through the faecal oral route where the greywater contaminated with pathogens may be directly ingested through contact with contaminated land or indirectly ingested through contact with contaminated items such as grass soil toys garden implements irrigation equipment and treatment plants while they are being serviced Transmission may also occur through inhalation of irrigation spray by penetration through broken skin and by insects such as flies and cockroaches All forms of wastewater when stored will turn septic unless the wastewater is treated to a high standard When greywater is stored it will turn septic giving rise to offensive odours and providing conditions for pathogens to multiply Nutrients Phosphorus and nitrogen are nutrients necessary for plant growth Greywater containing nutrients generated from the bathroom and laundry can be substituted for fertiliser and provide phosphorus and nitrogen to the garden and lawn Excessive phosphorus can be toxic to native plants and runoff of nutrients in stormwater may create environmental problems in our rivers and lakes Salts Washing detergents vary in their salt content Generally powdered detergents contain the most salt as it is included in washing powders as filler Concentrated powders generally contain less salt than normal powdered detergents and liquid detergents contain the least salt of all washing detergents The major risks of salts contained i
51. n Table B3 Table B3 Recommended Seasonal Irrigation Frequency Location NSW Frequency of irrigation event Summer Autumn Winter Spring Coastal Region Every 7 days Every 13 days Every 20 days Every 9 days Inland East of the Great Every 5 days Every 8 days Every 12 days Every 7 days Dividing Range Inland West of the Great Every 4 days Every 10 days Every 14 days Every 6 days Dividing Range Rainfall must also be considered as an irrigation event For every 1 mm of rainfall owners and residents need to adjust their irrigation volume by 1 litre per square metre 1 L m So if in the first week of January there is a rainfall event of 20 mm in a coastal area there will be no need to irrigate with greywater or any other water source for seven days Toilet Flushing The method described in this section can be used for estimating the potential amount of greywater that can be used for toilet flushing Only greywater treated by a GTS can be used for toilet flushing To estimate the amount of greywater that can potentially be reused for toilet flushing in the premises the number of residents and the type of toilet s installed at the premises needs to be determined Toilets are either full flush one button or dual flush two buttons Full flush toilets use 11 litres per flush and dual flush toilets use 3 0 litres for a half flush and 5 5 litres per full flush on average The calculation below assumes a ratio of four half flushes to
52. n greywater are the accumulation of salts in the soil structure leading to soil salinity and soil crusting which can cause degradation of the soil structure and damage to vegetation Sodium salts are of particular concern to vegetation Chemicals Greywater contaminated with bleaches such as hair dyes and nappy wash disinfectants including eucalyptus and tea tree oil and germicides can detrimentally affect the health of the soil by killing soil organisms Chemicals may also kill beneficial micro organisms used in a GTS reducing the effectiveness of the treatment process Physical Contaminants In untreated greywater systems those carrying out greywater diversion physical contaminants such as hair lint and dirt and sand from the shower washing machine and sinks have the potential to cause blockages to irrigation pipes hoses and or drippers Blockages of the irrigation system can lead to pooling of water Solids present in unfiltered greywater may also adversely impact on the drainage properties of the soil blocking drainage paths also leading to pooling of water and ineffectual water distribution Greywater contaminated with fats generated from soaps and fabric softeners can make soil water repellent When this happens water just runs off instead of soaking into the soil reducing the water available to plants Fats in greywater may also cause offensive odours where greywater is allowed to pool and turn septic Water Volume Exce
53. n in addition to overflow and backflow protection in the form of a backflow containment device are implemented and that the local water utility is notified in writing that a GTS is in place at the premises Written notification shall be in the form of as completed plans e g an amended sewer service diagram or other documentation as required by the local water utility Where a GTS is connected to internal fixtures for toilet flushing and washing machine use a back up water supply will be required to ensure a constant water supply to all fixtures should the GTS fail 4 4 Using Greywater Safely It is important that greywater treatment is undertaken sensibly to ensure that public health and the environment are protected The control measures presented here as a list of Dos and Don ts have been compiled to provide owners and residents with a guideline of how to best manage their reuse of treated greywater and ensuring the reuse of greywater achieves the performance standards required by the approval granted by council Each of these control measures is explained in further detail in Appendix C of these guidelines 18 NSW DEPARTMENT OF WATER AND ENERGY These are minimum requirements for greywater treatment systems council may have other requirements and conditions when the approval is given When reusing greywater treated by a greywater treatment system DO DO get council approval and install a greywater treatment system GTS th
54. ndry tub has a capacity full to the brim of 50 litres B3 Water Balance The total volume of greywater that has the potential to be reused Section 4 4 1 can be compared with the total amount of greywater that can be generated to meet the needs of the premises Section 4 4 2 to determine the water balance for the premises A water balance will allow the owner or resident to determine whether they generate enough greywater to supply their potential demand whether one source e g only the shower or only the washing machine of greywater is sufficient to meet their needs or whether they will need both greywater and drinking water to fulfil their demand The easiest way for owners or residents to determine their water balance is to write the volume of water that can potentially be reused and generated by the premises in a table form similar to the Table in the example below so that all volumes are clearly identified 36 NSW DEPARTMENT OF WATER AND ENERGY Example Water Balance Greywater Diversion Device The Smith family of four live in sewered residential premises and want to use greywater for irrigating the gardens in their backyard The Smith family can use a greywater diversion device GDD to divert greywater for sub surface irrigation only without prior approval from council providing they meet the self assessable conditions and follow the control measures for reusing greywater safely stated in these guidelines Garden size
55. ntroduction m Section 1 Introduction an overview of the purpose of the document and its application relevant to all readers m Section 2 Greywater Characteristics relevant to all readers Part B Compliance with this part is necessary to obtain an exemption for prior approval for greywater diversion devices m Section 3 Greywater Diversion Devices conditions for meeting the exemption criteria Part C Advisory information on the reuse of greywater m Section 4 Greywater Treatment Systems m Section 5 Manual Bucketing of Greywater Appendix A Greywater decision flow charts Appendix B Greywater reuse estimations Appendix C Best practice management controls Appendix D Greywater fact sheets 2 GREYWATER CHARACTERISTICS 2 1 Definitions Greywater For the purpose of these guidelines greywater means wastewater from washing machines laundry tubs showers hand basins and baths where a greywater diversion device or manual bucketing is used It does not include wastewater from a kitchen toilet urinal or bidet For the purpose of these guidelines it also means wastewater from washing machines laundry tubs showers hand basins baths and kitchens where a greywater treatment system is used It does not include wastewater from a toilet urinal or bidet Residential Premises Refers to a single detached household residential premises It does not include premises comprising more than one dwelling 2 2 Wher
56. odium boron and chloride DO select washing detergents that are low in salt consider using a powder concentrate or a liquid washing detergent refer to fact sheets for further information DO monitor plant and soil response to greywater irrigation DO occasionally irrigate with drinking water to disperse salts from the soil only necessary during extended periods of zero rainfall DO consider applying a soil rewetting agent every six months DO use a filter to screen solids when using a diversion device DO ensure that regular maintenance is undertaken including cleaning out the greywater diversion device filter weekly and maintaining the sub surface irrigation system NE ONININY ONIN SSA CAIN DO mark and label all pipes and use signs to indicate greywater reuse refer to Section 3 7 When undertaking diversion of greywater DON T x DON T leave a diversion device on all the time Treat it like a garden tap and only reuse greywater when the garden needs watering Greywater is for reuse not disposal DON T reuse toilet or kitchen wastewater DON T reuse greywater during rain DON T reuse greywater from the washing of nappies or contaminated clothing DON T reuse greywater when a resident is sick e g has diarrhoea DON T reuse greywater generated by cleaning in the laundry or bathroom or when using hair dye or other chemicals DON T reuse greywater generated by washing rag
57. on By avoiding irrigation to such areas risks associated with those hazards can be minimised NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 47 Control Don t let greywater go beyond the premises and cause a nuisance to neighbours Ensuring greywater does not go beyond the premises it was generated on will minimise health and environment risks external to the premises Installing greywater components no closer than one metre from the boundary line not irrigating during rain and not over watering will all help prevent greywater from going beyond the premises it was generated on Control Do be careful lifting and carrying buckets of greywater particularly over slippery surfaces and on stairs or steps Buckets of greywater can be heavy One litre of greywater weighs one kilogram so a full bucket is likely to weigh around five kilograms Be careful when lifting and carrying buckets of greywater to prevent injuries and in particular on slippery surfaces and on stairs and steps Consider using a second bucket and making two trips with half full lighter buckets Control Do install a greywater diverter that incorporates some form of non storage surge attenuation A non storage surge attenuation tank will prevent a surge of water from greywater generating appliances e g washing machines from flooding the diverter and instead allow a gradual amount of greywater to be released into the irrigation system
58. ow unless greywater is generated from washing nappies or clothes contaminated with faeces or vomit Jeppesen and Solley 1994 This suggests that the numbers of harmful pathogens are also low 2 4 2 Chemical and Physical Quality There is a high amount of variability in the chemical and physical quality of greywater produced by any household due to factors such as the source of water the water use efficiency of appliances and fixtures individual habits products used e g detergents shampoos soaps etc and other site specific characteristics The amount of salt sodium calcium magnesium potassium and other salt compounds oils greases fats nutrients and chemicals in greywater can largely be managed by the types of products used within a household The Dos and Don ts in Sections 3 4 and 5 provide guidance on how to manage the chemical and physical quality of greywater Appendix C also goes into further detail on the risks of using greywater and how to best manage these risks Nutrients Phosphorus and nitrogen are nutrients necessary for plant growth Greywater containing nutrients generated from the bathroom and laundry may be substituted for fertiliser to provide phosphorus and nitrogen to the garden and lawn Table 2 2 shows the estimated amount of nutrients contained in greywater reused on a one square metre irrigation area of a residential household over a one year period compared with the amount of nutrients applied by followin
59. ower heads are currently available For those owners and residents that are unsure of the type of shower head they have installed Table B6 provides a general explanation Table B6 Shower Head WELS Star Rating and Water Use Installation Date Shower Head Star Rating WELS Water Flow L min As part of WaterFix Sydney Water 3 Star 9 or a similar water efficiency program Within the last 15 years 2 Star 12 More than 15 years ago 1 Star 16 Source AS NZS 6400 2005 Once the number of residents and the shower head type is known using Table B7 the amount of greywater generated by the premises shower s can be determined by matching the number of residents row with the shower head type column It is assumed that the average shower length is seven minutes Loh and Coughlan 2003 and that every resident has one shower per day Table B7 Greywater Generation Shower and Bath Greywater Generation Shower and Bath L week Number of Residents Shower Head Shower Head Shower Head 1 Star 2 Star 3 Star 1 784 588 441 2 1568 1176 882 3 2352 1764 1323 4 3136 2352 1764 5 3920 2940 2205 6 4704 3528 2646 7 5488 4116 3087 Assumptions Average shower 7 minutes Source Loh and Coughlan 2003 Every resident showers or bathes once per day 7 times week 34 NSW DEPARTMENT OF WATER AND ENERGY Baths The amount of greywater generated by a bath is between 60 and 300 litres depending on the size of the bath and the le
60. r cars DON T reuse greywater so that it flows into the streets or down stormwater drains KKK KK KKK KKK KK xX DON T let greywater go beyond the property boundary and cause a nuisance to neighbours NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 23 GLOSSARY OF TERMS aquifer council drinking water dual reticulation fixture trap greywater greywater diversion greywater diversion device GDD greywater treatment system GTS groundwater local water authority non potable water non storage surge attenuation nutrients pathogen percolation residential premises 24 NSW DEPARTMENT OF WATER AND ENERGY A porous soil or rock formation which holds water Statutory corporation constituted under the Local Government Act 1993 for an area of NSW Water suitable for human consumption used for drinking food preparation personal hygiene and the removal of human wastes Two separate and distinct piping systems one of which is used to transport drinking water and the other for non potable water for final uses that do not require drinking water U shaped pipe below plumbing fixtures that provides a water seal to prevent sewer odours and gases from entering habitable areas For the purposes of these guidelines means wastewater from washing machines laundry tubs showers hand basins and baths but does not include wastewater from a kitchen toilet ur
61. r chemicals Ensuring that greywater containing any kind of bleach disinfectant or other chemical is diverted to sewer will reduce the risk of damage to the garden and lawn environment and of skin irritation arising from contact with chemicals Control Don t reuse greywater generated by washing of rags used for painting or for maintaining machinery and vehicles Paints grease and oil products should not be washed down the sink or toilet They should be disposed of in the bin or taken to a chemical collection point Ensuring that greywater generated from washing cloths or rags used for painting or maintaining machinery and vehicles is not reused for greywater will reduce the risk of damage to the garden and lawn environment and of skin irritation arising from contact with chemicals Control Do reuse greywater by manual bucketing at several locations rather than one single point Reusing untreated bucketed greywater at several locations will prevent an accumulation of chemicals and other contaminates in the soil Physical Contaminants Control Don t reuse kitchen wastewater Kitchen wastewater is heavily contaminated with oils and grease and is inappropriate for greywater reuse Kitchen wastewater can be reused after treatment by a GTS Control Do use a filter to screen solids when using a diversion device The use of a filter to screen solids from greywater that has been diverted for sub surface irrigation will prevent physical contamin
62. r the life of the installation The maintenance procedures provided by the manufacturer and any conditions of approval from the council must be carried out as specified The NSW Health issued certificate of accreditation for the greywater treatment system may also include specific maintenance requirements for the system 20 NSW DEPARTMENT OF WATER AND ENERGY 4 9 Responsibilities Table 4 1 Responsibilities for Greywater Treatment Systems Responsibility Action Undertake a water balance to determine water demand requirements S Ensure GTS meets the requirements of the NSW Code of Practice Plumbing and Drainage 3rd Edition 2006 S Apply for and obtain approval to install and approval to operate the GTS and associated irrigation from the S local council Engage a licensed plumber to install the GTS I Install sub soil sub surface or surface irrigation system to distribute greywater S Notify the local water utility that a GTS has been installed J at the property Undertake regular maintenance of the GTS in accordance with the manufacturer s recommendations and S these guidelines Undertake annual testing of backflow protection device S a It is the responsibility of the owner to organise annual testing of the backflow protection device by an accredited tester 4 10 Offences and Penalties There is an onus of responsibility on the owner of residential premises where a greywater treatment system GTS is instal
63. r use on the garden All of the information and calculations to undertake a water balance are provided in Appendix B Greywater Reuse Estimations A water balance provides guidance for managing greywater to protect public health and the environment It is essential that owners or residents complete the water balance in order to meet the conditions for exemption from council approval NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 13 3 5 Choosing a Greywater Diversion Device Greywater diversion devices GDDs are evaluated to the Australian Technical Specification ATS 5200 460 2005 Certification to the technical specification for plumbing and drainage products is obtained by the manufacturer by way of a WaterMark licence previously a Plumbing Safety licence Diversion devices are only exempt from requiring approval from council if they are licensed with a WaterMark licence previously a Plumbing Safety licence Figure 3 1 WaterMark Certification WaterMark source http www saiglobal com assuranceservices certification ProductCertification There are a number of certified GDDs available for installation at residential premises The Greywater Diversion Devices Register which is a list of licensed greywater diversion devices maintained by NSW Health can be accessed online at www health nsw gov au 3 6 _ Sub surface Irrigation Greywater generated by a GDD must only be reused for sub surf
64. re wet after an irrigation period Soil condition Check that soil is healthy Signs of Monthly unhealthy soil include damp and boggy ground hours after irrigation surface ponding and run off of irrigated water poor vegetation growth unusual odours clumping of soil fine sheet of clay covering surface Sensor probe if applicable Clean level sensor to ensure Weekly correct readings and subsequently pump operation This maintenance work itself has inherent health risks just like managing a worm farm or compost bin Rubber gloves and a mask should be worn and thorough washing of hands and clothes should take place immediately afterwards NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 15 3 9 Responsibilities Table 3 2 Responsibilities for Greywater Diversion Devices Responsibility Action Other Evaluate conditions for exemption from the prior approval by council and ensure overall compliance Undertake a water balance to determine water demand requirements JY Check with the local water utility that the property is serviced by a meter with an integral dual check valve to S ensure backflow protection of the water supply Engage a licensed plumber to install the GDD and associated non storage surge attenuation Z Ensure GDD and non storage surge attenuation meets the requirements of the NSW Code of Practice Plumbing A and Drainage 3rd Edition 20
65. rections 16 NSW DEPARTMENT OF WATER AND ENERGY ADVISORY INFORMATION ON THE REUSE OF GREYWATER Section 4 Greywater Treatment Systems Section 5 Manual Bucketing of Greywater 4 GREYWATER TREATMENT SYSTEMS 4 1 Overview A greywater treatment system GTS collects stores treats and may disinfect greywater to the standards specified in the NSW Health Domestic Greywater Treatment Systems Accreditation Guidelines February 2005 They can be installed in residential premises to provide treated greywater for reuse for irrigation including surface irrigation toilet flushing and washing machine use Appendix A outlines the process for choosing and installing a greywater treatment system 4 2 Accreditation NSW Health is responsible for administering the requirements of Clause 41 of the Local Government General Regulation 2005 in accrediting GTSs and circulating accreditation notices to Public Health Units and councils GTSs are accredited by the Director General of the Department of Health NSW Health following the process and standards specified in the Domestic Greywater Treatment Systems Accreditation Guidelines February 2005 A council must not approve the installation of a GTS unless the GTS has been accredited by NSW Health There are some instances where a GTS may be exempt from accreditation by the Director General of the NSW Health Department The criteria for exemption are explained on the NSW Health web page a
66. reywater This information is contained in Part C of this document Part C also contains guidance on the use of greywater treatment systems GTSs However it is important to note that greywater treatment systems continue to require prior approval from the relevant local government authority for installation and operation of the system Item C6 Section 68 Local Government Act 1993 There are no exemptions from this requirement A council must not approve the installation of a GTS unless the system has been accredited by the NSW Department of Health Clause 41 1 of the Local Government General Regulation 2005 These guidelines do not provide detailed information on the responsibilities of plumbers installers or manufacturers of systems Specific local state and federal requirements exist for plumbers installers and manufacturers of systems including the NSW Plumbing Code of Practice and the Trade Practices Act that should be considered as primary sources of information These guidelines provide comprehensive information for the reuse of greywater on residential premises in sewered areas of NSW These guidelines replace the NSW Health document Greywater Reuse in Sewered Single Domestic Premises April 2000 This document has been prepared by the Department of Water and Energy DWE on behalf of the NSW Government with input from other agencies including the Department of Health Department of Local Government and Sydney Water 1
67. rom kitchen or toilet plumbing m greywater is not stored in any way or treated other than primary screening or filtration m a washing machine standpipe or WaterMark licensed diversion device delivers the greywater to a sub surface irrigation system m the standpipe or diversion device has a switching or selection facility so that greywater can be easily diverted back to sewer m any diversion device connected to or modifying the existing plumbing system is a WaterMark licensed device previously a Plumbing Safety licence and must be installed by a licensed plumber m any diversion other than by gravity is only via a licensed non storage surge tank and pump system installed by a licensed plumber m some form of non storage surge attenuation is installed as part of the diversion system non storage surge attenuation can be in the form of a tank system a mulch basin or similar m the local water utility is notified in writing by the installing plumber that a greywater diversion device is in place m the landowner complies with these guidelines and any others issued by the Director General of the Department of Water and Energy It is the responsibility of the household owners to engage a licensed plumber to install the GDD and associated non storage surge attenuation It is the responsibility of the installing licensed plumber to install the GDD and non storage surge attenuation to meet the requirements of the NSW Code of Practice P
68. s and oils greases m non storage surge attenuation m an overflow device m a garden irrigation or distribution system Greywater from a diversion device is untreated and must only be reused for sub surface irrigation Greywater diversion is for the productive reuse not easy disposal of wastewater It is important for owners and residents to recognise that a diverter must be treated as a garden tap The diverter should only be turned on when the garden needs watering at all other times it must be turned off If the diverter is turned on all the time over watering has the potential to significantly damage plants and soil as well as increase the risk to residents health Any greywater that can not be immediately reused for sub surface irrigation at the residential premises must be diverted to sewer Reuse of greywater through a GDD at a residential household is considered to be a low risk activity if the requirements of these guidelines are met By reusing only greywater produced within the household for sub surface irrigation the health risks associated with pathogen exposure are reduced since those residing in the house are likely to have been exposed to the majority of the pathogens in the greywater through contact with the other residents at the household The main form of exposure for pathogens is through personal contact The reuse of greywater by a GDD where more than one dwelling is located on a block including groups of town houses
69. s to gardens and lawns By choosing to use a washing detergent that is low in phosphorus the phosphorus load of the greywater generated is reduced This is particularly important for a garden that contains native plants as the reduced phosphorus content will reduce the risk of damage to native plants Control Do monitor plant response to greywater irrigation Native plants are sensitive to phosphorus and waterlogging of soils and need to be monitored when irrigated with greywater to ensure that the phosphorus content of the greywater does not cause damage Control Don t irrigate if the premises is located on an aquifer that is used for drinking water If premises are located on a drinking water aquifer there is a risk of greywater percolating to the aquifer and contaminating the drinking water supply Fact Sheets A fact sheet Preventing Health and Environmental Impacts from Greywater Reuse has been produced to educate homeowners and residents in the dos and don ts for correct procedures and management techniques for maintaining a safe greywater water system that minimises health risks A fact sheet Selection of Household Detergents Soaps and Cleaning Agents has been produced to educate homeowners and residents about choosing the right personal and domestic cleaning products to maintain a greywater system that has a minimal impact on the environment 44 NSW DEPARTMENT OF WATER AND ENERGY Salts Control Do select garden
70. s used for painting or for maintaining machinery and vehicles XX KK KK X DON T reuse greywater to top up rainwater tanks or swimming pools 12 NSW DEPARTMENT OF WATER AND ENERGY DON T store untreated greywater DON T over water DON T reuse greywater on plants that will be eaten raw or where fruit has fallen to the ground and could be eaten DON T use greywater to wash paths driveways or cars DON T allow direct contact or ingestion of the greywater DON T use greywater to irrigate on dune sand or shallow rocky soil unless the soil has been enriched to a minimum 300mm in depth DON T reuse greywater so that it flows into the streets or down stormwater drains DON T install drippers of a sub surface irrigation system within one metre of boundary lines inground pools and inground potable water tanks and buildings DON T let greywater go beyond the property boundary and cause a nuisance to neighbours KK XK KK KK KX DON T use greywater in households where immuno suppressed occupants are present 3 4 Greywater Reuse Estimations To estimate a household s greywater requirements a water balance can be undertaken to consider both the amount of greywater that has the potential to be reused and the amount of greywater that can be generated to meet the needs of the household This is important because a typical metropolitan household can potentially generate much more water than is needed fo
71. s will generally result in greywater with a reduced risk of causing soil degradation In addition to choosing washing detergents that are low in salts and in particular sodium salts there are other ways of managing a household s soil to reduce the risks caused by salt application These include incorporating organic matter into the soil by mulching and the addition of lime or gypsum to already sodic soils NSW DEPARTMENT OF WATER AND ENERGY GREYWATER DIVERSION DEVICES Section 3 Greywater Diversion Devices Recommended Conditions for Gaining Exemption Compliance with this Part will assist in satisfying the conditions for an exemption from prior approval for greywater diversion devices 3 GREYWATER DIVERSION DEVICES This section outlines the guidelines specifically pertaining to the use of greywater diversion devices at residential premises in sewered areas of NSW Compliance with this section will assist in satisfying the conditions for an exemption from prior approval for the operation of greywater diversion devices 3 1 Overview A greywater diversion device GDD is a hand activated switch that diverts untreated greywater by gravity or pump directly to a sub surface irrigation system A diversion system incorporates the following features m ahand activated valve m a switch or tap which is fitted to the outlet of the waste pipe of the plumbing fixture e g a washing machine m a coarse filter for screening out solid
72. ssive watering with greywater or watering during wet weather will cause surface runoff or seepage to neighbouring properties and or stormwater drainage which ultimately finds its way to a natural watercourse Nutrients phosphorus and nitrogen contained in greywater may promote the growth of algal blooms in natural watercourses If greywater is continuously applied to soil chemical contaminants may cause damage to the soil structure and clogging of the soil s pore structure Healthy plant growth will not be promoted under these conditions NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 41 c4 Best Practice Management Controls If the controls contained in these guidelines are implemented greywater diversion can be carried out without approval from council Greywater treatment systems GTSs continue to require prior approval so the controls contained in these guidelines are the minimum and may be supplemented by council requirements In both cases the controls should enable owners and residents to manage their systems to protect public health and the environment The risks associated with reuse of greywater are generally not caused by the greywater itself but by the contaminants of the greywater and the way greywater is reused This means the homeowner and residents have the ability to manage risks by implementing controls that reduce the likelihood and or consequence of a potential hazard thus minimisin
73. t www health nsw gov au The irrigation system associated with the GTS does not require accreditation by NSW Health but requires prior approval of the council 4 3 Approvals A GTS is defined as a waste treatment device and therefore the owner of the premises must obtain prior approval from the council for installation and operation under Item C5 and C6 of Section 68 of the Local Government Act 1993 and Part 2 Division 4 Local Government General Regulation 2005 There are no exemptions to this requirement A council must not approve the installation of a GTS unless they have been accredited by the NSW Department of Health Clause 41 1 of the Local Government General Regulation 2005 Council may grant approval to install a GTS at a particular site in accordance with Item C5 Section 68 Local Government Act 1993 A GTS and the associated reuse distribution system s e g irrigation system reticulation for toilet flushing also require approval to operate from council in accordance with Item C6 of Section 68 It is the responsibility of the owner of the premises to engage a licensed plumber to install the GTS and to make any associated plumbing modifications e g pipe for toilet flushing It is the responsibility of the installing licensed plumber to install the GTS to meet the requirements of the NSW Code of Practice Plumbing and Drainage 3rd Edition 2006 The plumber must ensure that controls to prevent the incidence of cross connectio
74. ted clothes Greywater generated from the laundry is often the easier source of greywater to access although it is usually more contaminated than bathroom greywater Jeppesen and Solley 1994 Christova Boal et al 1996 Kitchen wastewater is sometimes considered as a greywater stream however for the reuse of greywater by greywater diversion devices GDDs it is not appropriate to include kitchen wastewater due to the contaminants food particles oil and grease Kitchen wastewater can be treated for reuse by greywater treatment systems GTSs Under the NSW Code of Practice Plumbing and Drainage 3rd Edition 2006 only greywater from the bathroom and laundry can be reused by GDDs Greywater from the kitchen must not be reused by GDDs 2 3 Water Usage Volumes The average single sewered household in Sydney based on 3 persons per household uses unrestricted 825 litres of water each day or approximately 300 000 litres 300 kilolitres per year Sydney Water 2005 This equates to approximately 339 litres of greywater per house per day Of this 198 litres is from baths and showers and 141 litres is from the laundry Table 2 1 Loh amp Coghlan 2003 Sydney Water 2005 Approximately 223 litres each day is used outdoors for garden and lawn irrigation car washing swimming pools etc Sydney Water 2005 By reusing greywater for irrigation a household has the potential to save between 50 000 and 100 000 litres of drinking water per year
75. th Control Do reuse diverted untreated greywater only for sub surface irrigation at least 100 mm below the surface of soil or mulch Untreated greywater from a licensed greywater diversion device must only be reused for sub surface irrigation This is a barrier approach using the soil to separate greywater from the surface and reduces the health risks associated with greywater reuse Sub surface irrigation places a barrier between the wastewater and humans and animals to prevent exposure In this case the barrier is a minimum 100 mm of soil or mulch If a mulch barrier is used the mulch must be maintained to a minimum 100 mm thickness Control Do install a greywater treatment system GTS that has been accredited by NSW Health Control Do reuse treated greywater from a GTS for irrigation including surface irrigation toilet flushing and washing machine only Greywater that has been treated by a NSW Health accredited GTS is designed to reduce pathogens and other contaminants to levels that allow it to be reused for irrigation including surface irrigation toilet flushing and washing machines 42 NSW DEPARTMENT OF WATER AND ENERGY Control Do wash your hands after manual bucketing Untreated greywater contains pathogens By washing your hands after using manual bucketing you will minimise the potential health risk caused by these pathogens Control Don t reuse greywater when a resident has diarrhoea or is sick Greywater s
76. th the Australian Standard AS 1345 WARNING RECYCLED RECLAIMED WATER DO NOT DRINK at intervals not exceeding 0 5 m All below ground pipes including those used for sub surface irrigation shall have an identification tape marked in accordance with the Australian New Zealand Standard AS NZS 3500 1 Clause 9 5 4 1 installed on top of the greywater pipeline running longitudinally and fastened to the pipe at not more than 3 m intervals 14 NSW DEPARTMENT OF WATER AND ENERGY 3 8 Maintenance Once a GDD is installed it is the owner s responsibility to ensure it is maintained for the life of the installation GDDs and their associated sub surface irrigation distribution systems require regular maintenance such as cleaning and replacing of filters and periodic de sludging of the surge tank periodic inspection of the sub surface distribution system and soil condition evaluation Table 3 1 Table 3 1 Recommended Maintenance for Greywater Diversion Devices GDD Component Maintenance Required Approximate Frequency Filter Clean filter Weekly filter should be removed and cleaned removing physical contaminants sand lint hair etc Replace filter As recommended by the manufacturer or as required usually every 6 12 months Surge tank Clean out sludge from surge tank Every 6 months Sub surface irrigation Check that water is dispersing Weekly distribution system regularly monitor soil to ensure all areas a
77. tlets connections taps appliances shall have signs that are marked WARNING DO NOT DRINK in accordance with the Australian Standard AS 1319 All pipes or pipe sleeves and identification tapes including those on pressurised irrigation systems shall be coloured purple as per the Australian Standard AS 2700 and marked with the following in accordance with the Australian Standard AS 1345 WARNING RECYCLED RECLAIMED WATER DO NOT DRINK at intervals not exceeding 0 5 metres All below ground pipes including those used for sub surface irrigation shall have an identification tape marked in accordance with the Australian New Zealand Standard AS NZS 3500 1 Clause 9 5 4 1 installed on top of the greywater pipeline running longitudinally and fastened to the pipe at not more than 3 m intervals 4 7 Irrigation The irrigation system connected to the GTS does not require installation by a licensed plumber but must follow the manufacturer s recommendations or design where relevant Irrigation systems shall not be connected to both the mains water and the greywater treatment system supply Greywater generated by a GTS may be reused for surface or sub surface irrigation Distribution pipes and fittings must be at least 1 metre from a boundary inground pool or inground potable water tank and pipes will generally need to be underground 4 8 Maintenance Once a GTS is installed it is the owner s responsibility to ensure it is maintained fo
78. total volume of greywater that can be reused per irrigation event A number of example volumes have been calculated and are presented in Table B2 This is based on the design irrigation rate for poorly drained light clays AS NZS 1547 2000 It is considered to be conservative for most soils and may be adjusted according to the health of the plants and soils at the site NSW GUIDELINES FOR GREYWATER REUSE IN SEWERED SINGLE HOUSEHOLD RESIDENTIAL PREMISES 31 Table B2 Examples of the Volume of Greywater Reused per Irrigation Event Volume of Greywater Reused per Irrigation Event L 1 m 5 m 10 m 25 m 50 m 20 100 200 500 1000 It is important that GDDs are only turned on when the garden needs watering Leaving a GDD turned on at all times has the potential to lead to over watering Just as a resident would not leave a drinking water tap turned on watering the garden at all times the GDD should be used as a tap that is typically turned off diverted to sewer When the tap is turned on it is to meet the needs of the irrigation event determined above from Table B2 Similarly treated greywater produced by a GTS should not be continuously supplied for irrigation and should only be used when irrigation is required The frequency of an irrigation event is dependant on the season During the summer months plants require irrigation more frequently than in the winter months The recommended frequency of irrigation events for the year is provided i
79. uthority Control Don t use greywater to top up swimming pools or rainwater tanks Both treated and untreated greywater may still contain pathogens Adding greywater to swimming pools or rainwater tanks will increase the potential for residents and others to come into contact with pathogens In addition greywater added to swimming pools and rainwater tanks would effectively be stored greywater increasing the levels of pathogens as well as causing odour and attracting vermin and insects Control Don t reuse greywater to wash paths driveways or cars Both treated and untreated greywater may still contain pathogens Allowing greywater to be reused to wash paths driveways or cars would increase the likelihood of human contact with pathogens and the potential for pathogens and other contaminants to be released from the premises Control Don t reuse greywater so that it flows into the streets or down stormwater drains Both treated and untreated greywater may still contain pathogens Greywater must be reused in such a way as to prevent greywater being discharged to streets or down stormwater drains It is important to remember that greywater is for reuse and is not to be disposed of Any greywater that cannot be used on the premises it is generated from must be diverted to sewer Nutrients Control Do select garden friendly detergents that are biodegradable and low in phosphorus Greywater can be substituted for fertiliser and provide nutrient
80. vel that the bath is filled to An average bath size is 260 litres when full However the majority of baths are for children and will be filled to between a quarter to a half of the full bath level generating 60 to 130 litres of greywater per bath This is the equivalent of one seven minute shower so the estimation for the amount of water generated by the shower can be used to estimate the amount of water generated by the bath Table B7 Assume that each resident showers or bathes once per day 7 times week for children that share a bath treat them as one resident for the purposes of the bath estimation only Basin Taps To estimate the amount of greywater that is generated by bathroom basin taps the number of residents at the premises needs to be determined It is estimated that each person uses 4 litres of water from the bathroom hand basin per day face washing teeth brushing hand washing This assumption is used to estimate the greywater generation from basin taps in Table B8 by matching the number of residents to the amount of greywater generated Table B8 Greywater Generation Basin Taps Number of Residents Greywater Generation Basin Taps L week 28 56 84 112 140 168 193 NID Om B W N e Washing Machines To estimate the amount of greywater that is generated by the use of washing machines the number of residents at the premises or the number of washes per week and the type of washing machine need to be d

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