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Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
Margaret River Water Recycling Water Balance and Cost Benefit Analysis
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Margaret River Water Recycling Water Balance and Cost Benefit Analysis

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Margaret River Water Recycling Water Balance and Cost Benefit Analysis …

Margaret River Water Recycling Water Balance and Cost Benefit Analysis
A study by Murdoch University Technology Centre that includes extending recycled water services to residential customers in future urban development areas of Margaret River

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  • 1. ETC cover page Shire of Augusta – Margaret RiverMargaret River Wastewater ReuseWater Balance & CostBenefit Analysis Report 21/2/2008
  • 2. Margaret River Wastewater Reuse Project - Stage 1 ReportAuthors:This report has been prepared by Cameron Everard, Dr Stewart Dallas and Dr MartinAnda of the Murdoch University Environmental Technology Centre (ETC).Document Governance and Intended UsageThis document has been produced for the sole use of the client only and any use by athird party may lead to inappropriate use of information. This document is deemedcorrect at the time of publication and its accuracy and appropriateness may changewhen further knowledge becomes available. Murdoch University and theEnvironmental Technology Centre accept no responsibility for inappropriate use ofthis document and may take legal action where copying and reproduction of thematerials within this document are used for consultancy and education without writtenprior permission from the Client and the Environmental Technology Centremanagement. i
  • 3. Margaret River Wastewater Reuse Project - Stage 1 Report Margaret River Wastewater Reuse Project - Stage 1 Water Balance and Cost Benefit Analysis ReportExecutive SummaryThe Shire of Augusta-Margaret River commissioned Murdoch University EnvironmentalTechnology Centre to conduct a study into the options for wastewater reuse in and around thetown of Margaret River. The objectives of this Stage 1 report were: • Preparation of a water balance to demonstrate the amount of water available and the area and/or number of lots that could be provided with treated wastewater; • Preparation of a cost benefit analysis to demonstrate economic viability of the project; and • Identify management plans that will be required.The water balance portrays three stages with four different scenarios and along with the netpresent value (NPV) costs are summarised below:Stages of Development Scenarios Cost NPV (Chronological) $ per kL of reused wastewaterStage 1 Scenario – 1: Existing POS Areas (28 ha) 10.49Stage 2 Scenario – 2: Margaret River Golf Course (25 ha) 13.00 Stage 3 Scenario – 3: Third Pipe to Future Urban Areas 12.50OR Stage 3 Scenario – 4: DWWTP: Part A 13.00 Scenario – 4: DWWTP: Part B (winter – recharge) 21.46 Scenario – 4: DWWTP: Part B (summer) 21.46Note: Scenarios 1-3 exclude cost of wastewater treatment. Scenario 4 includes full wastewater treatment withsome allowance for reduction in wastewater headworks and CSOs, The potential impact of both headworks andCSOs is significant and is discussed in detail in the Cost Benefit Analysis.Stage One - Scenario 1 – Existing POS areasScenario one would include irrigation of all current Shire POS areas with treated wastewaterfrom the MRWWTD, (includes schools, Gloucester Park and East Margaret River (EMR)POS (Riverslea, Rapids Landing and Brookfields) (28 ha). Does not include third pipeconnection for household toilet flushing or garden irrigation to these subdivisions.Stage Two - Scenario 2 – Margaret River Golf CourseThis scenario would comprise irrigation of all current Shire POS areas with treatedwastewater from the MRWWTD, (includes schools, Gloucester Park and EMR POS[Riverslea, Rapids Landing and Brookfields], 28 ha). This scenario also includes irrigation ofthe Margaret River Golf Course of approximately 25 ha.Scenarios 1 and 2 are also included in Scenario 3 below.Stage Three (centralised) - Scenario 3 – Third pipe to future urban areas (East and West)This scenario would include installation of a third pipe to all new subdivisions - all watersupplied from MRWWTD to subdivision households (for garden irrigation and toiletflushing) and irrigation of subdivision POS. Will require mains sewerage connection to theMRWWTD and third pipe connection to subdivision.Alternatively, the Shire may choose to pursue a decentralised option as follows:Stage Three (decentralised) - Scenario 4 - Integration of Decentralised WastewaterTreatment Plants (DWWTP) ii
  • 4. Margaret River Wastewater Reuse Project - Stage 1 ReportScenario 4 consists of two parts, Part A comprises the existing third pipe facilities from theMRWWTD to the Shire POS areas and the MRGC undertaken in Scenarios 1 and 2. As thisinfrastructure will have already been established it is considered separate to Part B.Part B would include the establishment of DWWTP’s to each new subdivision. Allwastewater produced in the subdivision will be directed to subdivision scale DWWTP fortreatment. Treated water from this unit could be used directly for irrigating POS within thesubdivision during the summer months and supplied to the households for toilet flushing andgarden irrigation. The subdivision would be considered a closed loop system, collectingtreating and recycling the wastewater within the subdivision. Each DWWTP would bedesigned to accommodate the estimated volumes of water produced within the subdivision.In Scenario 4 excess wastewater during winter could be diverted to irrigation if practical.Third pipe connection from DWWTP will be required for summer irrigation of thesubdivision POS. As this scenario is considered to be a closed loop system it does not requirethird pipe connection from the MRWWTD and due to low winter volumes should not needmain sewerage connection. Greywater could be either treated and recycled at the householdscale or directed to the DWWTP.The Management Plans that the Shire will need to prepare for Scenarios 1 to 3 will include: • Operation and Maintenance Plan (DoH); • Nutrient and Irrigation Management Plan (DoW); • Community Consultation Outcomes Report; and • Works Approvals and Licenses (DEC).In addition if Scenario 4 is developed, independent of the Water Corporation, the Shire willneed to use the services of a licensed sewerage service provider or secure its own WaterService Providers License (Sewerage Services) from the ERA or in some instances whereappropriate require land developers to secure their own license.The ecological benefits of Stage 1 of the project include a considerable increase inenvironmental flows for the Margaret River (approximately 169,000 kL/per year) (based on2007 abstraction rates) and the associated indirect downstream ecological benefits as a resultof increased water volumes in the river. If the MRGC were supplied with treated wastewater,there would be a decrease in the groundwater abstraction from the local aquifer and thereforeassociated indirect benefits. There would also be a further reduction in future water needs asStage 3 was commissioned to supply a third pipe to new subdivisions.In addition to the ecological benefits, the project will provide social and aesthetic benefits dueto the increased river flows, these include; a healthier looking river and the potential forincreased downstream eco-tourism activities in the river during the summer months, due tothe reduction in river abstraction. The treated wastewater will secure a water source for theirrigation of parks and public facilities into the future.The project also presents a positive message to the local Margaret River community in termsof sustainable water management and urban wastewater reuse and sets a precedent for otherurban wastewater reuse projects in Western Australia. The reuse of treated wastewater hasbeen successfully undertaken by more than 60 Shire councils around Western Australia forseveral decades in order to secure sustainable water management practices. The State WaterStrategy has also set a target of reusing 20% of treated wastewater sources by 2012. iii
  • 5. Margaret River Wastewater Reuse Project - Stage 1 Report CONTENTSExecutive Summary...................................................................................................iiIntroduction ............................................................................................................... 1 Background ........................................................................................................... 1 Recent Policy Developments.................................................................................. 1 Objectives.............................................................................................................. 2Treatment Processes .................................................................................................. 3Water Balance ........................................................................................................... 4 Water Supply - Inputs ............................................................................................ 4 Water Demand - Outputs ....................................................................................... 4Scenarios for Water Recycling................................................................................... 6 Scenario 1 – Existing POS Areas (Stage One)........................................................ 6 Scenario 2 – Margaret River Golf Course (Stage Two) .......................................... 6 Scenario 3 - Third Pipe to Future Urban Areas (Stage Three)................................. 7 Scenario 4 – Decentralised Wastewater Treatment Plant (Stage Three) ................ 10 Centralised vs Decentralised Treatment Systems.................................................. 12 Summary of Water Reuse Scenarios .................................................................... 13Cost Benefit Analysis .............................................................................................. 14Management Plans................................................................................................... 16Community Consultation ......................................................................................... 16Ecological and Social Benefits of the Project ........................................................... 18Recommendations ................................................................................................... 19References ............................................................................................................... 21Appendix 1: Margaret River Wastewater Reuse Scenarios - Water Balance ............. 22Appendix 2: Water Balance Assumptions ................................................................ 23Appendix 3: Guidelines for the Use of Recycled Water in Western Australia........... 25Appendix 4: Net Present Value (NPV) Calculations................................................... 1 List of TablesTable 1: Current irrigated areas and volumes within the SAMR ................................. 5Table 2: Scenario 1 – Summary of water balance calculations.................................... 6Table 3: Scenario 2 – Summary of water balance calculations.................................... 7Table 4: Assumptions for predicted future urban areas............................................... 9Table 5: Scenario 3 – Summary of water balance calculations – 2026 third pipe to future urban areas............................................................................................... 9Table 6: Scenario 4: Part A – Summary of water balance calculations...................... 11Table 7: Scenario 4: Part B – Summary of water balance calculations for decentralised WWTP self contained subdivision of 650 lots .................................................. 11Table 8: Annual rainwater tank yields for Perth ....................................................... 12Table 9: Advantages and disadvantages of centralised and decentralised treatment systems ............................................................................................................ 12Table 10: Summary of water balance under each scenario........................................ 13Table 11: Summary of water balance and capital costs under each scenario ............. 14 iv
  • 6. Margaret River Wastewater Reuse Project - Stage 1 ReportIntroduction BackgroundIn response to the increasing demand on natural potable water sources and a decrease inannual precipitation, the Shire of Augusta Margaret River (SAMR), propose to use treatedwastewater to irrigate their Public Open Space (POS), such as sports ovals and schools.The reuse of treated wastewater has been successfully undertaken by more than 60 Shirecouncils around Western Australia (Neil McGuinness, WA Department of Health, 2007) forseveral decades in order to secure sustainable water management practices. The State WaterStrategy has also set a target of reusing 20% of treated wastewater sources by 2012.It is envisaged that the treated wastewater will reduce and replace the current dependence onexisting water sources such as abstraction from the Margaret River and local groundwatersources. The SAMR are considering using the water to irrigate other POS around the townsitein the future. Investigations are under way for supplying a third pipe, to future residentialareas for toilet flushing, garden irrigation and POS. Third pipe with recycled wastewater isyet to be undertaken in Western Australia, and if implemented will set a new precedent inurban water use management. The first third pipe development in Western Australia wascompleted by Water Corporation at Brighton in the northern suburbs of Perth for the POS andhome gardens irrigation but this was only using community bore groundwater.Several studies to date have been undertaken in relation to the Project, they include: • Feasibility Investigation Report on the Margaret River Waste Water Reuse, (Wood and Grieve Engineers, 2006); • Preliminary Figures (HydroPlan Pty Ltd, 2005); and • East Margaret River Public Open Space and Landscape Development Guidelines (Shire of Augusta-Margaret River, 2007). Recent Policy DevelopmentsIt should be noted that as of September 2008 the provision for third pipe connection will bemandatory for all new subdivisions and homes in Western Australia for greywater andalternative water supply.The State Government has recently introduced the 5 Star Plus Building Code, whichencourages the reduction of water and energy use. The aims of the water use code are toreduce the consumption of water in residential homes by requiring water efficient fittings,minimising the wastage of water and facilitating the appropriate use of alternative sources ofwater such as grey water and rain water (Government of Western Australia, 2007)The installation of these alternative water sources for new subdivisions is strongly encouragedand discussed further in Section 3.6.5 Star Plus will be applicable to new homes approved for construction after 1 September2007. It is expected that the State Government will investigate measures to apply the 5 StarPlus provisions to existing homes by 2008 (Government of Western Australia, 2007).Moreover, the WA Government Department of Premier and Cabinet is currently formulatingthe State Water Recycling Strategy.The provision of recycled water to homes via third pipe will now be possible under the newWA Department of Health (DoH) regulations from the current 16 January 2007 “Guidelines 1
  • 7. Margaret River Wastewater Reuse Project - Stage 1 Reportfor the Use of Recycled Water in Western Australia” (Appendix 3). Water is required to betreated to different standards depending on its final use. Water for irrigation of POS areas canbe treated to Class B or C, whereas water for urban non-potable use will need to be treated toClass A as specified in the DoH guidelines.At a national level the “Australian Guidelines for Water Recycling: Managing Health andEnvironmental Risks” Phase 1 (Environmental Protection Heritage Council, 2006) haverecently been finalised as a part of the National Water Quality Management Strategy. Theproject will be conducted in accordance with these guidelines. ObjectivesThe objectives of this Stage 1 report as outlined in the proposal accepted by SAMR were: • Preparation of a water balance to demonstrate the amount of water available and the area and/or number of lots that could be provided with treated wastewater; • Preparation of a cost benefit analysis to demonstrate economic viability of the project; and • Identify management plans that will be required.(NB Upon completion of this Stage 1 study it was proposed that a Stage 2 contract include:supply modelling, (components, operation funding), treatment levels, licensing requirementsand management plans).The present study has investigated and quantified the current supply of wastewater availableat the Margaret River wastewater treatment dam (MRWWTD) with the demand for irrigatingPOS within the SAMR and to assess the feasibility of various scenarios for third pipeconnections to future residential areas.Preliminary figures have been calculated on projected volumes of wastewater to quantifysupply and demand of wastewater streams up to 2026 (Scenario 3). The Water Corporation’s2026 input volumes to the MRWWTD includes sewage from the townsite of Margaret Riverand exclude Witchcliffe and Gracetown townsites. These projected figures are based oninformation provided by the Water Corporation and are considered assumptive.It is envisaged that through the implementation of this proposal that a socially acceptable,economically sound and ecologically sustainable outcome can be achieved for the localcommunity, water users and the SAMR. 2
  • 8. Margaret River Wastewater Reuse Project - Stage 1 ReportTreatment ProcessesAt present the Water Corporation treats sewage at its Margaret River Wastewater TreatmentPlant located approximately 2.5 km north east of the Margaret River townsite.Sewage is pumped from the town via a 375 mm diameter rising main to the treatment plant.The treatment process consists of the following components: • Inlets works, complete with tanker receival facility, mechanical screening and screw- wash-press; • An Intermittent Decant Extended Aeration (IDEA) tank equipped with floating surface aerators and a decanting mechanism; • A chemical dosing facility, consisting of alum and caustic dosing; • A mechanical sludge dewatering system, including a gravity drainage deck and belt filter press; and • A treated effluent storage dam with a designed storage capacity of 450 ML.The Margaret River plant currently treats water to a Class C quality (Water Corp, 2008).Treated water is stored in the dam then sand filtered and chlorinated prior to irrigating theadjacent pine plantations. Irrigation to the pine plantations is conducted throughout the year,with irrigation rates to the pines based on soil saturation rates. The pine plantations areirrigated in winter if there is a dry period. The Water Corporation use a basic criteria of “nosurface runoff or ponding” when irrigating the adjacent plantation (Water Corporation, perscomm.). It is understood that the wastewater will not be required to undergo further treatmentto be suitable for irrigation purposes, however the chlorine dosing rate will be increased toaccount for the increased pipe distances.If treated water from the plant is to be used for a third pipe system in future urban areas forinternal non-potable purposes then further treatment and costs will be incurred due to treatingthe water from Class C to Class A. It is envisaged that an investigation of further treatmentand costs will be undertaken in the next stage of the project.Under the proposed irrigation system, the treated water will be pumped via a 250 mm pipe tobalance tanks located at the Margaret River Weir. It is expected that the existing pumping rateof 60 L/second will be sufficient to pump the water to the balance tanks. Water will bepumped to the POS areas from the balance tanks via a 150 mm pipe. Further technicalinvestigations will be necessary to ascertain pumping rates, pipe sizes and balance tank sizes. 3
  • 9. Margaret River Wastewater Reuse Project - Stage 1 ReportWater BalanceThe following key tasks have been calculated as a part of the water balance (Refer toAppendix 1): 1. Quantification of incoming wastewater and incident rainfall flows and evaporation from the treatment dam (Supply); and 2. Future public and urban areas to be irrigated (Demand). Water Supply - InputsAs of April 2007 approximately 1,768 dwellings were connected to the main sewer of 2734available (Water Corporation, pers comm.), which feed into the MRWWTD.During the summer and public holidays there will be an increase in tourist numbers visitingthe town and therefore an increase in inflows to the treatment dam. The Margaret RiverVisitor Centre reported that the months of highest visitation was January, April andDecember. It is understood that most visitors to the Shire would be spread acrossaccommodation facilities located in sewered and unsewered areas. Wastewater generatedfrom visitors to the sewered areas would already be accounted for in the inflow volumes tothe treatment dam. Visitors to unsewered areas are not likely to contribute to the increase inflows to the dam as wastewater from these accommodation facilities would treated through aseptic tank or alternative treatment system approved by the SAMR. The summer holidaymonths of December, January and April usually correspond to higher inflow volumes at thetreatment dam.The increase in absentee land owners occupying properties in sewered areas during thesummer months will also increase inflow volumes to the treatment dam.The wastewater treatment dam is located approximately 2.5 kms from town and receivesapproximately 359,000 kL of wastewater per year (982 kL per day). The treatment dam has adesigned storage capacity of 450,000 kL.Rainfall to the MRWWTD minus evaporation reduces the volume of water by 14,000 kL peryear on average. Therefore, the approximate volume of water available for use in theMRWWTD is 345,000 kL (345 ML) per year. The area of the MRWWTD has been estimatedat 30,000m2.The treated wastewater from the MRWWTD is currently drip irrigated to the adjacent pineplantation at approximately 323,000 kL/per year. Informal discussions with the WaterCorporation in June 2007 have identified that the Forest Products Commission plan to harvestthe surrounding pine plantations that are currently irrigated in 2009. Therefore an alternativeuse for the water will need to be established by this time. Current volume of water available for irrigation = 345,000 kL (345 ML) per year. Water Demand - OutputsThe SAMR currently abstracts water from the Margaret River Weir for irrigation purposes.The water is pumped via an automated system (150mm pipe) to irrigate schools, POS andovals. Irrigation of the ovals occurs twice per week, approximately 30mm/per week 4
  • 10. Margaret River Wastewater Reuse Project - Stage 1 Report(15mm/session). The main irrigation pump has been designed to pump at 12.25L/second at600kPa.Water required for irrigating schools, POS and ovals (except Riverslea Subdivision) is134,000 kL/per year (17.8 ha) or approximately 7,528 kL/ha/year.Based on the above irrigation rate, approximately 35,000 kL/per year is abstracted from theMargaret River for the Riverslea Subdivision. Therefore it is estimated that approximately169,000 kL/per year is currently abstracted for the irrigation of 22.4 ha of Shire POS. Abreakdown of the POS areas that are irrigated by the SAMR, their size and irrigation volumesare provided in Table 1.Table 1 does not include the POS areas of Brookfield and Rapids Landing. It is understoodthat these areas are not currently irrigated by river water. These two additional areas havebeen included in the water balance calculations for Scenario 1 and total 28 ha (refer to Table2).Table 1: Current irrigated areas and volumes within the SAMR Irrigated Areas Hectares (ha) Approximate Volume (kL) (based on 7,528 kL/ha/yr)Gloucester park 11 83,000Reuther park/ bowling green 1 7,500Two state schools 5.8 44,000Riverslea subdivision 4.6 34,500Total (approximate) 22.4 169,000Table 1 highlights the importance of a wastewater reuse scheme; approximately 169 ML ayear will need to be abstracted from the Margaret River in 2008 for irrigation of the aboveareas. It is understood that the SAMR are currently renewing their water abstraction licenceadministered through the Department of Water (DoW). Abstraction of river water could stillbe used to offer a supplementary supply, provided volumes were within DoW licensed limits.The assumptions used in the water balance are provided in Appendix 2. 5
  • 11. Margaret River Wastewater Reuse Project - Stage 1 ReportScenarios for Water RecyclingThe water balance is presented in Appendix 1 and portrays three stages with four differentscenarios. The four scenarios have been created and refined from several discussions with theSAMR. It is understood that the SAMR will implement the three stages in succession. Thescenarios are summarised below and described in detail in this section:Stages of Development (Chronological) ScenariosStage 1 Scenario – 1: Existing POS Areas (28 ha) Stage 2 Scenario – 2: Margaret River Golf Course (25 ha) Stage 3 Scenario – 3: Third Pipe to Future Urban Areas OR Stage 3 Scenario – 4: DWWTP: Part A Scenario – 4: DWWTP: Part B (winter – recharge) Scenario – 4: DWWTP: Part B (summer) Scenario 1 – Existing POS Areas (Stage One)Scenario 1 includes the irrigation of all current Shire POS and existing subdivisions (EastMargaret River EMR POS) from the MRWWTD. Table 2 below summarises the outcomes ofthe water balance calculations. Under this scenario, approximately 134,000 kL of waterwould be available for other irrigation purposes, such as the adjacent pine plantation or thirdpipe applications.Table 2: Scenario 1 – Summary of water balance calculationsIrrigated Areas Approximate Volume (kL) paTotal available water for irrigation in MRWWTD 345,000Shire irrigation 28 ha (schools, ovals, EMR POS) 211,000Dam level and water available for other irrigation 134,000following irrigation of Shire POSThe current average irrigation rate for other POS and turfed areas in the SAMR is in the orderof 7528 kL/ha/year. On this basis, approximately 17 ha of POS could potentially be irrigatedwith the remaining water available in the dam. Scenario 2 – Margaret River Golf Course (Stage Two)Further opportunities to use treated wastewater include the Margaret River Golf Course(MRGC), which is located approximately 5.3 km by road from Gloucester Park. The MRGCcurrently obtains water from on-site dams and groundwater bores and is assessing the costsand benefits of pumping treated wastewater for irrigation purposes.A report undertaken by Hydroscapes Australia Pty Ltd in June 2007 estimated the currentdesigned irrigation system can deliver up to 396,000 kL/per year (over 9 months), howeveractual water usage rates for the MRGC are in the order of 188,000 kL/per year (based on7500 kL/ha/year for 25 ha). No irrigation is undertaken at the golf course during the wintermonths.Scenario 2 includes the irrigation of all current Shire POS areas with treated wastewater fromthe MRWWTD, (includes schools, Gloucester Park and EMR POS) and irrigation of theMRGC (approximately 25 ha).Table 3 below summarises the outcomes of the water balance calculations. In this scenarioapproximately 54,000 kL of additional water would be required to be derived from other 6
  • 12. Margaret River Wastewater Reuse Project - Stage 1 Reportsources such as bore or river water for the months of February, March and April. It isrecommended that the MRGC investigate ways of reducing overall water use based oncurrent best practice in the industry.Table 3: Scenario 2 – Summary of water balance calculationsIrrigated Areas Approximate Volume (kL) paTotal available water for irrigation in MRWWTD 345,000Shire irrigation 28 ha (schools, ovals, EMR POS) 211,000Margaret River Golf Course (25 ha) 188,000Total water required 399,000Water required from other sources 54,000Based on data extrapolated from Water Corporation predictions, preliminary calculationsindicate that the 400,000 kL of irrigation water required for Scenario 2 could be available by2009 (refer to Figure 1 below). Scenario 3 - Third Pipe to Future Urban Areas (Stage Three)Scenario 3 consists of installing a third pipe connection system to all new subdivisions. Waterwould be supplied from the MRWWTD to the subdivision for irrigation of the POS andinclude connection to each household for garden irrigation and toilet flushing. This scenariohas not factored in the installation of household onsite greywater systems.The new subdivisions will require mains sewerage and third pipe connection to theMRWWTD. Volumes of water required for scenarios 1 and 2 are also included in the scenario3 calculations.Predicted inflow volumes to the MRWWTD have been obtained from the Water Corporationand are as follows: 2007 = 358,526 kL per year (982 kL/ per day) (actual recorded volume); 2015 = 550,000 kL (1507 kL/ per day) (Water Corporation prediction); and 2026 = 910,000 kL (2493 kL/ per day) (Water Corporation prediction).According to the SAMR the population of Margaret River in June 2007 was approximately5,400. The current inflow into the MRWWTD is 358,526 kL/per year, with approximately1768 connections (or 203 kL/connection/year).The Water Corporation has projected a steady increase reaching approximately 550,000kL/per year in 2015 to 910,000 kL/per year by 2026, based on a population of approximately12,500.Based on these figures, approximately 4,482 connections would be contributing to theMRWWTP in 2026. However, it should be noted that there is likely to be an increase inhousehold water usage over time associated with increasing standards of living, e.gdishwashers and spa baths. This would result in similar volumes of water with fewerconnections. Therefore this figure is considered assumptive.Various occupancy rates are available ranging from 2.4 – 2.7 occupants per dwelling, for thepurpose of this report an average 2.6 occupants per dwelling has been selected in line with therecent Rapids Landing development.Additions from rainfall and losses through evaporation were calculated at approximately14,000 kL per year. The following estimates have been made with respect to wateravailability for third pipe usage in the future urban areas: 7
  • 13. Margaret River Wastewater Reuse Project - Stage 1 Report 2007 = 345,000 kL per year 2015 = 536,000 kL per year 2026 = 896,000 kL per year(Calculations are provided in Appendix 1)Figure 1 below shows a gradual increase in the volume of water available for reuse.Figure 1. Available wastewater volumes from MRWWTP 1998 – 2026Note: Volumes include additions from rainfall and losses from evaporation.Note that with the increasing acceptance of greywater reuse and water conservation strategiesat all levels of government and the community, there could be a reduction in the volume ofwastewater discharged into the main sewerage system. On the contrary, a doubling of theresidential population may actually result in more wastewater inflows due to additionalconnections to the main sewerage system within existing developed areas due to sewerageinfill.The MRWWTD has a designed capacity of 450,000 kL, based on current increases in inflowvolumes it will be at full capacity by 2010. An alternative reuse/disposal option will need tobe assessed and commissioned as the adjacent pine plantations are earmarked for harvestingin 2009. However with the commencement of irrigation of POS and golf course andcommissioning of a third pipe to future urban areas the volume of dam water will be reducedand therefore provide increased capacity. Controlled releases to water courses from winterstorage dams may also be feasible subject to water quality objectives.The recent Rapids Landing subdivision (formerly termed Lot 27 subdivision) has been usedas a standard subdivision template. The Rapids Landing subdivision is expected to houseapproximately 1,690 people and comprises a total land area of 82.5 ha of which 6 ha havebeen allocated for POS. The area has been subdivided into 650 lots with an occupancy rate of2.6 per lot (Simon Munckton, Lester Group, pers comm.).In the absence of any planning data (except population increases) for future subdivisions, theRapids Landing subdivision figures were extrapolated to account for an increase inpopulation. 8
  • 14. Margaret River Wastewater Reuse Project - Stage 1 ReportFuture total population figures have been based on Water Corporations projections ofapproximately 12,500 in 2026. It has been assumed that this would consist of approximately7,000 from existing town areas, infill and EMR areas and approximately 5,500 in future urbanareas (new subdivisions). It has been assumed that of the 4,482 connections potentiallyavailable in 2026, approximately 44% or 1,972 connections could be connected to futureurban areas.When a population of 5,500 was applied to the future urban areas at an occupancy rate of 2.6(comparable with Rapids Landing) approximately 2,115 lots/connections resulted. Thereforean average of 2000 connections for future urban areas has been assumed for this scenario.Based on 4,482 connections and an occupancy rate of 2.6 the population would beapproximately 11,600, the Water Corporation has used an occupancy rate of 2.7 (12,100). TheSAMR has estimated that the population in 2026 will be between 10,200 and 12,900. Apopulation of 12,500 has been selected in line with the Water Corporation, however isconsidered assumptive at this stage. Inflow volumes for dwellings have been assumed atapproximately 203 kL per year.The following assumptions (Table 4) were made regarding the future urban areas up to 2026.Table 4: Assumptions for predicted future urban areasElement Rapids Landing Subdivision Future Urban Areas (with 3rd pipe) – 2026 (Actual) (Predicted)Population 1,690 5,500 (Total MR popln: approx 12,500)No. of lots/connections 650 2,115 (approx 2000)No. of subdivisions 1 3POS (ha) 6 18Occupancy rate per lot 2.6 2.6Table 5 below summarises the results of the water balance calculations. In this scenarioapproximately 68,000 kL would be available for other uses (9 ha of POS). The volumes intable 5 for third pipe for toilet, irrigation and POS are only for the 3 subdivisions in new areasand not for existing areas (town, infill and EMR area). At this stage these figures should beconsidered assumptive.Table 5: Scenario 3 – Summary of water balance calculations – 2026 third pipeto future urban areasIrrigated Areas Approximate Volume (kL) paTotal available water for irrigation in MRWWTD 896,000Shire irrigation 28 ha (schools, ovals, EMR POS) 211,000Margaret River Golf Course (25 ha) 188,000Future 3 rd pipe to subdivisions (3 sub) (toilet, irrigation) 294,000Future 3 rd pipe to subdivisions (3 sub) (POS, 18 ha) 135,000Total water required 828,000Dam level/ available water 68,000Inflow volumes outlined in Table 5 have been sourced from the Water Corporation’s 2026predictions (assuming additional 3 subdivisions for future residential areas).Preliminary estimates show that the total required water to accommodate scenario 3(approximately 828,000 kL) could be available by 2025, based on Water Corporations inflowvolumes. 9
  • 15. Margaret River Wastewater Reuse Project - Stage 1 ReportIf scenario 3 only included Shire POS, MRGC and POS with the future residential areas (18ha), then 534,000 kL per year would be required. This volume could be available by 2015. Scenario 4 – Decentralised Wastewater Treatment Plant (Stage Three)Scenario 4 consists of two parts; Part A comprises the existing third pipe facilities from theMRWWTD to the Shire POS areas and the MRGC. As this infrastructure will have alreadybeen established it is considered separate to Part B. As Part A would be operational, Part Bwould run concurrently as each subdivision was approved and constructed. As Part B isconsidered a closed looped system in terms of wastewater treatment and reuse the stand alonedevelopment can be considered in isolation to the other scenarios.Part B would include the establishment of Decentralised Wastewater Treatment Plants(DWWTPs) to each new approved subdivision.Decentralised systems involve the collection, treatment and reuse of wastewater from homesor communities at or near the point of generation (Tchobanoglous, 1995). Centralisedtreatment on the other hand, consist of conventional systems (sewers), centralised treatmentplants and disposal/reuse of the treated effluent, usually far from the point of origin(Tchobanoglous, 1996).All wastewater produced in each new subdivision will be directed to a subdivision scaleDWWTP for treatment. Treated water from this unit could be used directly for irrigating POSwithin the subdivision during the summer months and supply households with non-potablewater for toilet flushing and garden irrigation.The subdivision would be considered a closed loop system, collecting treating and recyclingthe wastewater within the subdivision. Each DWWTP would be designed to accommodate theestimated volumes of water produced within the subdivision.Excess treated wastewater during the winter could be diverted to an irrigation/pasture area orreinjected into the local aquifer through a Managed Aquifer Recharge (MAR) process.Alternatively, if practical, the water could be discharged into a constructed wetland area orengineered water feature and allowed to naturally infiltrate into the local superficial aquifer.The most appropriate method would have to be assessed on a site-by-site basis taking intoconsideration issues associated with winter storage of treated wastewater.Third pipe connection from the DWWTP will be needed for summer irrigation of POS. Thisscenario does not require third pipe connection from the MRWWTD and ideally should notneed main sewerage connection due to low volumes of water produced in winter and thepotential for onsite reuse. Greywater treatment systems could be installed at the householdlevel to irrigate private gardens or connected to the DWWTP.If newly approved subdivisions do adopt this closed loop water management strategy they arelikely to be self sufficient in terms of water treatment capacity and irrigation reuse. There willbe no need for main sewerage connection and therefore no contributions to the MRWWTD.Predicted inflows into the MRWWTD for Part A of this scenario have been based on current2007 inflow volumes (345,000 kL/per year) plus an extra 30,000 kL per year to account foradditional connections from the existing Cowaramup townsite and infill within the MargaretRiver townsite, as no additional water would be discharged back to the MRWWTD from thenew subdivisions. 10
  • 16. Margaret River Wastewater Reuse Project - Stage 1 ReportCreating future subdivisions that are closed looped and self sufficient in terms of watertreatment and reuse would shift more responsibility onto the developer to provide appropriatewater treatment facilities during the design and costing of the subdivision.The volumes used for Scenario 4 Part B are based on a single subdivision such as RapidsLanding. This assumes the subdivision has approximately 1,690 people with 6 ha of POS and650 lots. A summary of the water balance calculations is provided in Tables 6 and 7 below.Table 6: Scenario 4: Part A – Summary of water balance calculationsIrrigated Areas Approximate Volume (kL)Total available water for irrigation in MRWWTD 345,000 + 30,000Shire irrigation 28 ha (schools, ovals, EMR POS) 211,000Margaret River Golf Course (25 ha) 188,000Total water required 399,000Water required from other sources 24,000Table 7: Scenario 4: Part B – Summary of water balance calculations fordecentralised WWTP self contained subdivision of 650 lotsIrrigated Areas Approximate Volume (kL)Total available water for irrigation from DWWTP* 119,0003rd pipe from DWWTP within subdivision (for toilet)* 26,0003rd pipe from DWWTP within subdivision (for irrigation)* 69,0003rd pipe from DWWTP within subdivision (for POS 6 ha)* 45,000Total water required 140,000Water to be irrigated/recharged locally (winter) 38,000Water required from other sources (summer) 60,000*Volumes based on Water Corporation’s Domestic Water Use Study, 2001.Based on the assumption of an additional 30,000 kL contribution of wastewater for Part A,24,000 kL of water would be required from other sources. In reality, this figure could besomewhat higher than the assumed 30,000 kL, in which there would be enough wateravailable to irrigate the Shire POS areas and the MRGC. It is anticipated that sufficient waterwill be available for Part A, due to a yearly increase of approximately 30,000 kL.For Part B, approximately 7,500 kL of water per month will need to be reused or storedduring the May to September period or approximately 38,000 kL over the 5-month period.This water could be reused in several different ways depending on the opportunities andconstraints presented at each individual subdivision. Further feasibility studies would need tobe undertaken early in the planning stages to allow for the integration of these systems. Forexample additional POS or a designated wetland landscaped area with high water and nutrientuptake plants could be included in the subdivision design.During summer, approximately 60,000 kL of additional water will be required for irrigationof the POS, toilet flushing and garden irrigation within each subdivision of approximately 650lots. The majority of this water will be used for household garden irrigation during summerand could be reduced if strict water conservation measures are applied to households in linewith other states.This scenario has the potential to save up to 119,000 kL of scheme water per year, persubdivision of this size (similar to Rapids Landing) and could easily accommodate irrigationof the subdivision POS. 11
  • 17. Margaret River Wastewater Reuse Project - Stage 1 ReportRainwater tanks could be fitted and plumbed to each house to harvest rainwater for in-houseand ex-house purposes. Due to the Mediterranean climate experienced in the south west ofWestern Australia, winters are wet and cold, while summers are dry and hot, rainwater tanksare most useful when plumbed for in-house use to take advantage of high winter rainfall. Thiswater can be used for toilet flushing and washing machines and contributes to the overallreduction of scheme water over the year. In addition, a small amount of rainwater could beused in the garden to offset a portion of the water required by the third pipe system.A study undertaken by Marsden Jacob and Associates in March 2007 shows rainwater yieldsfrom various roof areas and rainwater tanks plumbed for in-house and ex-house use. Theresults summarised below in Table 8 are based on Perth rainfall and therefore are consideredslightly conservative.Table 8: Annual rainwater tank yields for Perth Tank Size 2 kL 5 kL 10 kL Roof Area 50m2 200m2 50m2 200m2 50m2 200m2 Annual Yield (KL) 29 58 30 74 30 84Adapted from Marsden Jacob Associates (2007)Houses with a 50m2 roof area and 2,000 L rainwater tank would yield approximately 29,000L a year. Larger houses with a roof area of 200m2 would yield approximately 58,000 kL peryear. On this basis, the installation of rainwater tanks plumbed to the house for in-house andex-house use should be strongly encouraged in new subdivisions.Installing rainwater tanks to all new houses would also reduce the demand for scheme watersupply to the subdivision. If rainwater tanks where installed to supply 100% of the needs ofinternal potable water use (drinking, washing, etc), then a roof area between 200 and 250 m2and a tank size between 45 kL and 70 kL would need to be established in order for the 99%reliability criteria to be met (GHD, 2007). Centralised vs Decentralised Treatment SystemsThe water balance calculations have identified that there is sufficient water to proceed withStages 1 and 2 of the project. There are two possible options that could be considered for thefuture urban areas (Stage 3).Two different scenarios have been assessed for the development of Stage 3. Scenario 3involves a conventional centralised treatment system requiring main sewerage and third pipeconnection to all new subdivisions. Scenario 4 involves provision for subdivision scaledecentralised systems and would involve subdivisions to be self sufficient in water treatmentand reuse. Table 9 below briefly summarises the advantages and disadvantages of centralisedand decentralised systems.Table 9: Advantages and disadvantages of centralised and decentralisedtreatment systemsTreatment System Advantages of system Disadvantages of system • Shire can defer responsibility for • Cost and energy use for installation andScenario – 3 management of the expanded operation;Centralised Third-Pipe system to Water Corporation; • Conventional and expensive deepSystem from • Preferred by WA Dept of Health. sewerage with pump stations;MRWWTP • Disturbance to townsite during installation.Scenario – 4 • Closed loop system, whereby water • Shire and/or developers may need to 12
  • 18. Margaret River Wastewater Reuse Project - Stage 1 ReportSubdivision scale and nutrients treated and reused develop new internal systems orDecentralised onsite; subcontract arrangements toTreatment Plant • Reduced pumping and energy costs; manage and maintain the DWWTP; • Less expensive shallow sewerage • Need to develop winter storage or and fewer pump stations; recharge facilities on a case by • Reduced disturbance to townsite case basis; during installation; • Water Service Providers License may • In the event of a breakdown, only the be required from ERA; subdivision is impacted. • Regular monitoring and reporting to regulatory authorities.The Murdoch University Environmental Technology Centre has prepared a database of over150 commercially available DWWTPs from around Australia and the world and categorisedthem in terms of their treatment type and application. Summary of Water Reuse ScenariosThe water available or required under each scenario is summarised in Table 10 and discussedbelow.Table 10: Summary of water balance under each scenarioScenarios Available water per year Water required from other (kL) sources per year (kL)Scenario – 1: Existing POS Areas (28 ha) 134,000 0Scenario – 2: Margaret River Golf Course (25 ha) 0 54,000*Scenario – 3: Third Pipe to Future Urban Areas 2026 68,000 0Scenario – 4: DWWTP: Part A – 1 subdivision 0 24,000*Scenario – 4: DWWTP: Part B (winter – recharge) 38,000 0Scenario – 4: DWWTP: Part B (summer) 0 60,000** Water required from other sources (e.g. river water, rainwater tanks or dam water)Scenario 1 – no additional water is required and approximately 134,000 kL of water isavailable for further irrigation use. This could be disposed to the adjacent pine plantation until2009 or treated to a suitable quality for aquifer recharge.Scenario 2 - approximately 54,000 kL of additional water would need to be derived fromother sources such as groundwater for the months of February, March and April tosupplement the third pipe water.Scenario 3 – no additional water is required and approximately 68,000 kL would be availablefor other uses in 2026. Estimates show that the total required water to accommodate scenario3 (approximately 828,000 kL) could be available by 2025.Scenario 4 - approximately 7,500 kL of water per month will need to be reused during theMay to September period or approximately 38,000 kL over the 5-month period. This watercould be reused in several different ways depending on the opportunities and constraintspresented at each individual subdivision.During summer, approximately 60,000 kL of additional water will be required for irrigationof the POS, toilet flushing and garden irrigation within the subdivision. The majority of thiswater will be used for household garden irrigation. The additional water could be obtainedfrom a combination of sources such as groundwater and rainwater tanks plumbed to the housefor in-house and ex-house use. 13
  • 19. Margaret River Wastewater Reuse Project - Stage 1 ReportCost Benefit AnalysisThe water available or required and associated capital costs under each scenario aresummarised in Table 11 and discussed below (Refer to Appendix 4 for NPV calculations).Table 11: Summary of water balance, NPV and NPV/kL under each scenarioScenarios Reused Available Water NPV ($m) NPV ($) over wastewater water p.a. (kL) required from over 25 25 years at (kL) other years at 10% per kL of sources p.a. 10% recycled (kL) wastewaterScenario – 1Existing POS Areas (28 211,000 134,000 0 2.21 10.49ha)Scenario – 2Margaret River Golf 399,000 0 54,000* 5.18 13.00Course (25 ha)Scenario – 3Third Pipe to Future 828,000 88,000 0 10.34 12.50Urban AreasScenario – 4 399,000 0 24,000* 5.18 13.00DWWTP: Part AScenario – 4DWWTP: Part B (winter 38,000 0 21.46– recharge) 140,000 2.56Scenario – 4DWWTP: Part B 0 60,000* 21.46(summer) • Water required from other sources (e.g. groundwater, river water, rainwater tanks or dam water) • Note CSO and headworks reductions for Scenario 4B. Refer text below.The costs presented in Table 11 build on the previous costing done by Wood and Grieve(2006) with additional development to account for in-house third pipe and decentralisedsystems. Wood and Grieve (2006) estimated an “order of magnitude” capital cost of$1,890,000 (plus GST) for a 135ML/year reuse system.In order to normalise the capital and operating costs for the various scenarios net presentvalues (NPV) have been calculated assuming an effective life of 25 years (with depreciationto 10%) and 10% discount rate. A sensitivity analysis was conducted with 7%, 10% and 15%discount rates.Supply mains as expected are the single largest component of these costs for all scenarios,except Scenario 4, due to the relatively large distances involved in the transfer of treatedwastewater. Annual pumping costs have been calculated but are relatively minor. Other coststo be incurred but not as yet quantified are ongoing water quality monitoring costs as requiredby the relevant regulatory authorities. Sale of the treated wastewater (third pipe water andgolf course) can be expected to contribute to offsetting these annual operating costs.Scenarios 2 and 3 are comparable in terms of dollars per kilolitre of wastewater treated($13/kL and $12.5/kL respectively) despite the near doubling in size of infrastructure capitaloutlay. This is due to the efficiencies to be gained in Scenario 3 due to the increased volumesbeing supplied, again nearly double. 14
  • 20. Margaret River Wastewater Reuse Project - Stage 1 ReportScenario 4B represents a near doubling ($21.46/kL) in the cost of treated wastewater on a$/kL basis when compared to Scenarios 2 and 3 on a pure ‘infrastructure only with somerebate’ basis. The external factors which have a significant impact on this outcome are: • Cost of treating the wastewater and providing potable water. All other scenarios do not include the cost of treating the wastewater (Customer Service Obligations (CSO) are currently borne by Water Corp/State Government and are typically $3,000-$4,000 pa/connection for water and wastewater service); • Headworks charges. Headworks per lot are water = $3,278, wastewater = $1,514 at full rates; and • Increasing tariffs. It can be assumed that the cost to the consumer for the provision of potable water and wastewater treatment is likely to rise above historic rates in the near future.Scenarios 1-3 do not include the cost of wastewater treatment by the Water Corporation,typically $3,000-$4,000 pa/connection for water and wastewater service. In order to allow atrue comparison of the various scenarios on an economic basis is necessary therefore that thetrue cost of wastewater treatment either be added to these scenarios (1-3) OR deducted fromScenario 4. The latter approach has been taken here. CSOs were identified as a significantissue in the Gracetown Development Project (GHD, 2007).On this basis for Scenario 4 an annual CSO equivalent of $1,000pa/connection has beenapplied with a full one-off headwork reduction for wastewater of $1,514. That is, noreductions in potable water and full reductions (100%) for wastewater have been applied.Despite this the NPV/kL is still approximately twice the other scenarios.Of note however is the significant impact that would occur with reductions in headworks andCSOs for potable water. This has been illustrated as Scenario 4B with full water rebate asshown in Appendix 4 and reveals a NPV of +$95/kL. The implication of this for futurestandalone developments is that subdivisions that are able to operate completely independentof the Water Corporation and receive headworks reductions and CSO returns under thecurrent rebate policy would return a positive cashflow to the developer (or community).Several additional issues that may need to be addressed include: a) The state of the existing pump station at the Margaret River crossing. Wood and Grieve (2006) have allowed a provisional $50,000 to upgrade however this may be inadequate in the short term and certainly in the medium term; b) The hours during which irrigation with treated effluent may occur. Experience from the McGillvray Oval scheme indicates that subject to DoH conditions, and the high use of the Gloucester Park ovals, increased main sizes may be required to ensure all irrigation occurs in a reduced irrigation time window. This has a significant cost implication; c) Gypsum injection is often recommended for treated wastewater irrigation schemes and while it represents additional costs (capital and on-going) there exist merits for its consideration. 15
  • 21. Margaret River Wastewater Reuse Project - Stage 1 ReportManagement PlansThe Health Act 1911 contains a number of provisions that regulate the use of recycled water.The WA Department of Health (DoH) requires the preparation of the following documentsfor approval of the Project: • Operation and Maintenance Plan; • Monitoring Plan; and • Reporting regime.The DoH has recently published guidelines on providing homes with recycled water via thirdpipe systems. The “Guidelines for the Use of Recycled Water in Western Australia”(Appendix 3) were released in January 2007. In summary the guidelines provide informationto planners, designers, installers and users of recycled water systems, with the objectives of: • Encouraging and providing guidance on the beneficial use of recycled water; • Reducing impact to public health and the environment; • Providing guidance for the planning, design, operation and monitoring of recycled water systems; and • Outlining statutory approvals needed for reuse schemes. (Department of Health, 2007).For wastewater reuse schemes the DoW has two Water Quality Protection Notes (WQPN)that outline procedures that should be followed: • WQPN 22, July 2006 Irrigation with nutrient-rich wastewater; and • WQPN 33, July 2006 Nutrient and irrigation management plans.Nutrient and irrigation management plans (NIMPs) are detailed guidelines for theestablishment and growing of crops, gardens, trees or turf. NIMPs demonstrate that inputssuch as water and fertiliser should be well matched to the plant growth cycle resulting inminimal contaminant leaching into the surrounding environment. The DoW requires NIMPsfor rural and recreational land areas exceeding 5,000 square metres where vegetation isirrigated, fertiliser is applied, animals are held intensively in paddocks and/or organic solidscontaining nutrients are spread onto the land. NIMPs are also suited to sites where industrialor municipal wastewater rich in nitrogen (N) and phosphorus (P) is applied to foster thegrowth and maintenance of healthy vegetation. They may be required for lesser areas wherelocal water values are particularly sensitive to nutrient contamination.If the Shire decides to run the DWWTP itself independent from Water Corporation it willneed to use a licensed subcontractor or secure a Water Service Providers License (SewerageServices) from the Economic Regulation Authority of Western Australia (ERA). This willrequire preparation of all of the plans above beforehand and approvals from the agenciesmentioned above before the licence can be granted. These provisions are listed under theWater Services Licensing Act 1995.Community ConsultationA community consultation program for the Project has been initiated by the SAMR. To datevarious publications, surveys and information have been distributed to the community ofMargaret River. These include: • Specific stakeholder consultation with developers and catchment groups; 16
  • 22. Margaret River Wastewater Reuse Project - Stage 1 Report • Articles in the local newspaper; • Discussions with local radio; • Inclusion of water recycling in the 2007 community survey; and • Articles in local shire briefs/publications.Informal discussions with the SAMR have indicated that the Margaret River community hasbeen very supportive of the Project so far. Ongoing consultation will be required by theSAMR and a Community Consultation Outcomes Report submitted to the relevant agenciesin order to proceed through the approvals process. 17
  • 23. Margaret River Wastewater Reuse Project - Stage 1 ReportEcological and Social Benefits of the ProjectThe ecological benefits of the project include a considerable increase in environmental flowsfor the Margaret River (approximately 169,000 kL/per year) (based on 2007 abstraction rates)and the associated indirect downstream ecological benefits as a result of increased watervolumes in the river. If the MRGC were supplied with treated wastewater, there would be adecrease in groundwater abstraction from the local aquifer (up to approximately 188,000kL/per year, 2007 rates) and therefore associated indirect benefits.In addition to the ecological benefits, the project will provide social benefits due to theincreased river flows, these include; a healthier looking river and the potential for increaseddownstream eco-tourism activities in the river during the summer months, due to thecessation of river abstraction. The quality of recreational facilities will also be able tomaintained by the SAMR as a secure source of treated water will available for irrigationpurposes.The project also presents a positive message to the local Margaret River community in termsof sustainable water management and urban wastewater reuse and sets a precedent for otherurban wastewater reuse projects in Western Australia. 18
  • 24. Margaret River Wastewater Reuse Project - Stage 1 ReportRecommendationsThe following recommendations are provided: • Undertake further feasibility studies to identify potential opportunities and constraints of centralised and decentralised wastewater treatment systems in future subdivisions (Scenario 3 and 4); • The MRGC investigate ways of reducing overall water use based on current best practice in the industry; • Plan to incorporate sustainable water use options in all future residential areas. A comparison of the costs/benefits of mandatory onsite greywater treatment units, water efficient appliances and domestic rainwater tanks (plumbed) for future subdivisions would be of merit; • The SAMR formulate strategies for reducing and phasing out river abstraction in consultation with the DoW and other key stakeholders; and • Investigate concerns/issues that the public may have with respect to the implementation of DWWTP and third pipe projects through a community consultation process.Future tasks would include: • Supply modelling - Identify the necessary supply elements from source to final application including hardware, supply organisations’ and consumers’ responsibilities in terms of operation and maintenance; • Treatment level - Investigate current and possible treatment levels with existing infrastructure, treatment levels required for different supply models; • Determine the existing and likely future legal requirements pertaining to Customer Service Obligations. Refer ERA (2007); • Regulatory requirements under various State legislation such as: o Environmental Protection Act 1986 (Works Approval and Operating Licence) administered under DEC; o Health Act 1911 (Guidelines for the Use of Recycled Water) administered under DoH; and o Water Services Licensing Act 1995 (Water Service Providers License) administered under ERA. • Prepare appropriate management plans for government regulatory departments, these include, Nutrient and Irrigation Management Plan (DoW) and an Operation and Maintenance Plan (DoH).Following the findings of this report, it is recommended that the SAMR move towards the useof recycled water for non-potable purposes such as irrigation of POS and the golf course(scenarios 1 and 2). 19
  • 25. Margaret River Wastewater Reuse Project - Stage 1 ReportIn the longer term, the SAMR should consider the integration of current best practice andplanning into all new future residential areas with the aim that newly developed areas are selfsufficient in terms of water treatment and reuse based on decentralised treatment systems, orprovision for a third pipe, where practical. Rainwater harvesting for internal potable purposesshould also be considered as a part of the overall water management strategy of future urbanareas. 20
  • 26. Margaret River Wastewater Reuse Project - Stage 1 ReportReferencesDepartment of Health (2007) Guidelines for the Use of Recycled Water in Western Australia.January 2007.Environmental Protection Heritage Council (2006) Australian Guidelines for WaterRecycling: Managing Health and Environmental Risks” Phase 1. National Water QualityManagement Strategy. November 2006.Economic Regulation Authority (2007). Draft Report. Inquiry on Competition in the Waterand Wastewater Services Sector. ERA WA.GHD (2007) Gracetown Development Project - Phase 1 Sustainable Water and WastewaterServices. Prepared for Landcorp. August 2007.Government of Western Australia (2007) 5 Star Plus – Energy Use in Houses Code andWater Use in Houses Code. Department of Housing and Works. May 2007.HydroPlan (2005) Preliminary Figures. HydroPlan Pty Ltd. November 2005.Marsden Jacob and Associates (2007) The Cost-Effectiveness of Rainwater Tanks in UrbanAustralia. Prepared for the Australian Government National Water Commission. March 2007.Shire of Augusta-Margaret River (2007) East Margaret River Public Open Space andLandscape Development Guidelines. Prepared by the Shire of Augusta-Margaret River 2007.Tchobanoglous, G. (1995) Decentralised Systems for Wastewater Management. Presented atthe Water Environment Association of Ontario Annual Conference, Toronto, Canada.Tchobanoglous, G. (1996) Appropriate Technologies for Wastewater Treatment and Reuse,Australian Water and Wastewater Association. Water Journal, Vol.23, No.4.Water Corporation (2001) Domestic Water Use Study in Perth, Western Australia 1998 –2001. March 2001.Wood and Grieve (2006) Margaret River Waste Water Reuse Feasibility InvestigationReport. Prepared for the Lester Group. May 2006. 21
  • 27. Margaret River Wastewater Reuse Project - Stage 1 ReportAppendix 1: Margaret River Wastewater Reuse Scenarios - WaterBalance 22
  • 28. Margaret River Wastewater Reuse Project - Stage 1 ReportAppendix 2: Water Balance AssumptionsThe following assumptions and calculations have been applied to the water balance model: 1. No industrial wastewater is included in the volumes; 2. Estimated area of wastewater treatment dam - 300m x 100m = 30,000m2; 3. Water required for irrigation of schools and ovals (except Riverslea subdivision) (2007) approximately 134,000 kL/per year (17.8 ha) or 7528 kL/per ha/per year (7 months); 4. Irrigation of Shire POS areas (including Riverslea subdivision) = 168,626 kL (22.4 ha) for 7 months (note April and October halved and added to summer months December and January); 5. 2026 Population projections - 12,500 (Source: Water Corporation); 6. Wastewater inflow volumes (Source: Water Corporation) 2007 = 358,526 kL per year (982 kL per day); 2015 = 550,000 kL per year (1507 kL per day); 2026 = 910,000 kL per yer (2493 kL per day); 7. Available wastewater volumes (plus rainfall - evaporation) minus 14,000 kL per year 2007 = 345,000 kL per year (945 kL per day); 2015 = 536,000 kL per year (1468 kL per day); 2026 = 896,000 kL per year (2455 kL per day); 8. Scenario 3: Third pipe water usage for toilet flushing and irrigation at future urban areas = 2000 houses within approximately 3 subdivisions; Toilet flushing = 112 L/hse/day, garden irrigation (ex-house) = 500 L/hse/day = 612 L/hse/day. (Data derived from single residential figures [Perth Domestic Water Study] and Water Corporation figures; Summer: Oct - Apr = 612 L/hse/day x 2000 hse/lots = 1224 kL/day x 212 days = 260,000 kL/year (toilet flushing and irrigation); Winter: May - Sep = 112 L/hse/day x 2000 hse/lots = 224 kL/day x 153 days = 34,000 kL/year (toilet flushing, no irrigation); Total = 294,000 kL/per year for toilet flushing and garden irrigation (ex-house activities); Summer garden irrigation only = 500 L/hse/day x 2000 hse/lots x 212 days = 212,000 kL (summer) (Source: Perth Domestic Water Study, Water Corporation 2001); 23
  • 29. Margaret River Wastewater Reuse Project - Stage 1 Report Scenario 3: Third pipe water usage for POS at future urban areas (Stage 3), 18 ha @ 7528 kL/ha/year = 135,000 kL/year. An irrigation year = 7 months or 212 days (No irrigation May - Sep); Scenario 3 - Future population (2026) = 7,000 (MR Town, infill and EMR area) + 5,500 (Future Residential Areas) = 12,500;9. Scenario 4: Total in-house water use (1 subdivision to DWWTP) (based on single residential figures + Water Corporation) = 500 L/hse/day x 365 days x 650 hse/lots = 118,625 kL/year; Blackwater = 112 L/hse/day (toilet) + 75 L/hse/day (Tap), Greywater = 170 L/hse/day (Bath and Shower) + 130 L/hse/day (Washing Machine), Other = 13 L/hse/day. Total = 500 L/hse/day (Water Corporation projections);10. Scenario 4 - treated water usage: Toilet flushing = 112 L/hse/day, garden irrigation (ex-house use) = 500 L/hse/day = 612 L/hse/day (Data based on single residential figures - Perth Domestic Water Study); Summer: Oct - Apr = 612 L/hse/day x 650 houses/lots = 398 kL/day x 212 days = 84,376 kL/year (toilet flushing and irrigation, ex-house); Winter: May - Sep = 112 L/hse/day x 650 houses/lots = 72.8 kL/day x 153 days = 11,138 kL/year (toilet flushing, no irrigation); Total yearly for 1 subdivision (650 lots) = 95,514 kL/per year for toilet flushing and garden irrigation; Yearly volume - toilet flushing = 112L/hse/day x 650 houses/lots x 365 days = 26,572 kL/year; Yearly volume - irrigation, ex-house (Oct-Apr) = 500L/hse/day x 650 houses/lots x 212 days = 68,900 kL/year;11. Rapids Landing (Lot 27 subdivision), total land area 82.5 ha, 650 lots @ 2.6 occupants per lot = 1690 persons (Simon Munckton Lester Group, pers comm);12. Third pipe water usage for POS (6 ha) at Rapids Landing subdivision, 7528 kL/ha/year = 45,168 kL/year. Irrigation year consists of 7 months or 212 days (No irrigation between May and September);13. BoM data (rainfall and evaporation) sourced from Witchcliffe and Jarrahwood respectively; and14. Margaret River Golf Course irrigation rates based on 25 ha @ 7500 kL/ha = 187,500 KL no winter watering between June and August. Note May and September halved and added to summer months December and January. 24
  • 30. Margaret River Wastewater Reuse Project - Stage 1 ReportAppendix 3: Guidelines for the Use of Recycled Water in WesternAustralia 25
  • 31. Appendix 1Wastewater Reuse Study - Water BalanceShire of Augusta Margaret RiverMain Sewer connections 1768Available sewer connections 2734(Source: Water Corporation) (2007)Wastewater treatment dam - surface area 30,000 (m2)Evaporation factor of storage area 1Max designed capacity of treatment dam 450,000 (kL)Vegetation type of irrigated area TurfCrop factor 0.6Irrigation efficiency 85 (%)Total irrigated area (Shire area 07/08) 28 (ha)Monthly Rainfall and Evaporation Data May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr TotalMonthly rainfall (mm) - Witchcliffe 2006 50.8 88.6 139.8 194 73.2 66.6 68.8 10 18.2 3.8 26.4 35.4 776Monthly evaporation (mm) - Jarrahwood 2006 (sum of -56 -38.6 -52.2 -65.6 -71.1 -120.4 -133.4 -183.1 -158 -148 -135.6 -66.6 -1,229availble daily totals) (Source: BoM)Rainfall to treatment dam minus evap (kL)(-ve -156 1,500 2,628 3,852 63 -1,614 -1,938 -5,193 -4,194 -4,326 -3,276 -936 -13,590values represents evaporation from dam)Wastewater May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr TotalWastewater inflow at treatment dam (kL) 28,582 26,070 27,280 33,821 29,610 30,938 30,540 30,256 31,372 27,720 31,527 30,810 358,526Wastewater inflow at treatment dam (kL/day) 922 869 880 1,091 987 998 1,018 976 1,012 990 1,017 1,027 982(Source: Water Corporation)Total monthly wastewater plus rainfall-evap 28,426 27,570 29,908 37,673 29,673 29,324 28,602 25,063 27,178 23,394 28,251 29,874 344,936(Available for irrigation) (kL) No Shire irrigation undertaken during winterIrrigation Requirements May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr TotalShire irrigation POS Stage 1 (28 ha) (kL) 0 0 0 0 0 15,056 30,112 45,168 45,168 30,112 30,112 15,056 210,784Golf course irrigation requirements (25 ha) (kL) 10,416 0 0 0 10,416 20,833 20,833 31,249 31,249 20,833 20,833 20,838 187,500Future urban areas third pipe (toilet/garden) (kL) 5,300 5,300 5,300 5,300 5,300 38,175 38,175 38,175 38,175 38,175 38,175 38,175 293,725Future urban areas third pipe (for POS, 25.8 ha) (kL) 0 0 0 0 0 13,873 27,746 41,619 41,619 27,746 27,746 13,873 194,222Total irrigation requirements 15,716 5,300 5,300 5,300 15,716 87,937 116,866 156,211 156,211 116,866 116,866 87,942 886,231(Source: SoAMR)Current pine plantation irrigation May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr TotalTotal monthly wastewater available 28,426 27,570 29,908 37,673 29,673 29,324 28,602 25,063 27,178 23,394 28,251 29,874 344,936Pine irrigation (Source:Water Corporation) 30,028 0 2,070 36,435 49,003 14,894 37,409 34,361 34,884 24,539 34,061 26,013 323,697Dam level (kL) -1,602 27,570 27,838 1,238 -19,330 14,430 -8,807 -9,298 -7,706 -1,145 -5,810 3,861 21,239Scenario 1 - Shire POS (28 ha) May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr TotalSupply StartTotal available wastewater for irrigation (kL) Dam 28,426 27,570 29,908 37,673 29,673 29,324 28,602 25,063 27,178 23,394 28,251 29,874 344,936Demand LevelPine plantation irrigation 06/07 (not included) 0 30,028 0 2,070 36,435 49,003 14,894 37,409 34,361 34,884 24,539 34,061 26,013 323,697Existing Shire irrigation POS (28 ha) (kL) (kL) 0 0 0 0 0 15,056 30,112 45,168 45,168 30,112 30,112 15,056 210,784Dam level/avail for pines (kL) cumulative 28,426 55,996 85,904 123,577 153,250 167,518 166,008 145,903 127,913 121,195 119,334 134,152 134,152Scenario 2 -Shire POS (28 ha) + Golf Course (25 May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr Totalha)Supply StartTotal available water for irrigation (kL) Dam 28,426 27,570 29,908 37,673 29,673 29,324 28,602 25,063 27,178 23,394 28,251 29,874 344,936Demand LevelExisting Shire irrigation POS Stage 1 (28 ha) (kL) 0 0 0 0 0 0 15,056 30,112 45,168 45,168 30,112 30,112 15,056 210,784Golf course irrigation requirements (25 ha) (kL) (kL) 10,416 0 0 0 10,416 20,833 20,833 31,249 31,249 20,833 20,833 20,838 187,500Total water required (kL) 10,416 0 0 0 10,416 35,889 50,945 76,417 76,417 50,945 50,945 35,894 398,284Dam level (kL) cumulative 18,010 45,580 75,488 113,161 132,418 125,853 103,510 52,156 2,917 -24,634 -22,694 -6,020 0Water required from other sources - approx -24,634 -22,694 -6,020 -53,348Scenario 3 - third pipe to future urban areas (3 May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr Totalsubdivisions-18 ha POS) 2026 (+ scenario 1 and2)SupplyTotal available water for irrigation (kL) Start 74,666 74,666 74,666 74,666 74,667 74,667 74,667 74,667 74,667 74,667 74,667 74,667 896,000Demand Dam
  • 32. Existing Shire irrigation POS Stage 1 (28 ha) (kL) Level 0 0 0 0 0 15,056 30,112 45,168 45,168 30,112 30,112 15,056 210,784Golf course irrigation requirements (25 ha) (kL) 0 10,416 0 0 0 10,416 20,833 20,833 31,249 31,249 20,833 20,833 20,838 187,500Future urban areas third pipe (for toilet/garden) (kL) (kL) 6,800 6,800 6,800 6,800 6,800 37,142 37,143 37,143 37,143 37,143 37,143 37,143 294,000Future urban areas third pipe (for POS, 18 ha) (kL) 0 0 0 0 0 9,644 19,286 28,927 28,927 19,286 19,286 9,644 135,000Total water required (kL) 17,216 6,800 6,800 6,800 17,216 82,675 107,374 142,487 142,487 107,374 107,374 82,681 827,284Dam level (kL) cumulative 57,450 125,316 193,182 261,048 318,499 310,491 277,784 209,964 142,144 109,437 76,730 68,716 68,716Water required from other sources - approx 0Scenario 4 - Part A existing third pipe facilites May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr Totalfrom MRWWTD to POS + MRGC.Part B - DWWTP + third pipe from DWWTP forfuture urban areas (1 subdivision only) POS (6ha) + household toilet and gardenPart ASupply (2007 volumes plus additional 30,000 kL/per year)Total available water for irrigation (kL) (2007 volumes) Start 31,250 31,250 31,250 31,250 31,250 31,250 31,250 31,250 31,250 31,250 31,250 31,250 375,000Demand DamExisting Shire irrigation POS Stage 1 (28 ha) (kL) Level 0 0 0 0 0 15,056 30,112 45,168 45,168 30,112 30,112 15,056 210,784Golf course irrigation requirements (25 ha) (kL) 0 10,416 0 0 0 10,416 20,833 20,833 31,449 31,449 20,833 20,833 20,838 187,900Total water required (kL) (kL) 10,416 0 0 0 10,416 35,889 50,945 76,617 76,617 50,945 50,945 35,894 398,684Dam level (kL) cumulative 20,834 52,084 83,334 114,584 135,418 130,779 111,084 65,717 20,350 655 -19,040 -4,644 0Water required from other sources - approx -19,040 -4,644 -23,684Part BSubdivision scale water balance (stand alone) -based on 650 persons per 1 subdivision (DWWTP)SupplyWastewater from subdivision to DWWTP (In-house 9,885 9,885 9,885 9,885 9,885 9,885 9,885 9,885 9,885 9,885 9,885 9,890 118,625blackwater and greywater) (kL)DemandFuture subdivision third pipe from DWWTP for 2,228 2,228 2,228 2,228 2,226 12,053 12,053 12,053 12,053 12,053 12,053 12,058 95,514toilet/garden (kL)Future subdivision third pipe from DWWTP for POS (6 0 0 0 0 0 2,845 6,453 10,061 10,061 6,453 6,453 2,845 45,168ha) (kL) (Based on 7528 kL/per ha/per year)Total water required (kL) 2,228 2,228 2,228 2,228 2,226 14,898 18,506 22,114 22,114 18,506 18,506 14,903 140,682Available water after reuse 7,657 7,657 7,657 7,657 7,659 -5,013 -8,621 -12,229 -12,229 -8,621 -8,621 -5,013Water to be recharged locally (Winter) 7,657 7,657 7,657 7,657 7,659 0 0 0 0 0 0 0 38,287Water required from other sources - approx 0 0 0 0 0 -5,013 -8,621 -12,229 -12,229 -8,621 -8,621 -5,013 -60,344(summer)Summary - Irrigation ScenariosStage 1Scenario 1 - existing Shire POS areas (28 ha) includes schools, gloucester park and EMR POS (Riverslea, Rapids Landing and Brookfield)Stage 2Scenario 2 - existing Shire POS areas (28 ha) includes schools, gloucester park and EMR POS (Riverslea, Rapids Landing and Brookfield) - Golf Course (25 ha)Stage 3Scenario 3 - existing Shire POS areas (28 ha) includes schools, gloucester park and EMR POS (Riverslea, Rapids Landing and Brookfield) - Golf Course (25 ha) OR - third pipe to future urban areas (approx 3 subdivisions) POS (18 ha), and household toilet flushing and garden irrigation from MRWWTP (2026)Scenario 4 - Part A - existing Shire POS areas (28 ha) includes schools, gloucester park and EMR POS (Riverslea, Rapids Landing and Brookfield) - Golf Course (25 ha) - Part B - Installation of Decentralised Wastewater Treatment Plant (DWWTP) to each new subdivision - third pipe from DWWTP to POS (6 ha) and toilet flushing and garden irrigation, local irrigation, no third pipe from MRWWTD
  • 33. Margaret River Wastewater Reuse Project - Stage 1 ReportAppendix 4: Net Present Value (NPV) Calculations ECONOMIC ASSESSMENT OF MARGARET RIVER WASTEWATER REUSE Assumptions Description ValueMains electricity price ($/kWh) 0.13Synergy buyback price ($/kWh) 0.13 Not usedMains water price ($/kL) 0.60 Not usedDiscount rate 0.10 All cash flows are incremental, replacing baseline or default equipment NPV Model Maintenance Headworks Revenue cost - Value of Salvage value Effective life savings ($) - Capital cost ($/yr) - Operational nominal energy/water ($ @ end of NPV Volumes Item (yrs) Note 1 ($) Note 2 cost ($/yr) ($/yr) saved ($/yr) life) ($) (ML) NPV ($/kL) Development scenarios 10% Scenario W&G 25 Payable $1,925,000 $3,700 $1,000 $1 $192,500 -$1,949,886 135 -$14.444 Scenario 0 25 Payable $1,925,000 $4,700 $1,000 $1 $192,500 -$1,958,963 170 -$11.523 Scenario 1 25 Payable $2,126,549 $10,750 $1,000 $1 $212,655 -$2,213,568 211 -$10.491 Scenario 2 25 Payable $5,020,693 $22,200 $1,000 $1 $502,069 -$5,184,932 399 -$12.995 Scenario 3 25 Payable $10,112,100 $34,500 $1,000 $1 $1,011,210 -$10,340,995 827 -$12.504 Scenario 4A 25 Payable $5,020,693 $22,200 $1,000 $1 $502,069 -$5,184,932 399 -$12.995 Scenario 4B 25 $984,100 $7,135,000 650,000 $260,000 $1,000 $1 $713,500 -$2,554,069 119 -$21.463 Scenario 4B with full water rebate 25 $3,114,800 $4,020,200 1,950,000 $260,000 $1,000 $1 $402,020 $11,348,035 119 $95.362Note 1: Headworks cost savings/lot assuming no reduction for water and 100% reduction for wastewater ($1514). Full potential reduction for water (100% = $3278).Note 2: Annual CSO equivalent of wastewater has been assumed at 100% (=$1000pa). Allow 0% reduction in potable water due to recycled water for potable water supply for Scenario 4.Total potential CSO is $3,000pa/connection for water ($2000) and wastewater ($1000). 26
  • 34. Guidelines for the Use of Recycled Water in Western Australia 16 January 2007Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 1 of 66
  • 35. Table of Contents1. Introduction .......................................................................................................4 1.1 Objective.................................................................................................4 1.2 Scope of the Guidelines..........................................................................4 1.3 Regulatory Framework ...........................................................................5 1.4 Approval Process....................................................................................52. Recycled Water Quality and Treatment .........................................................6 2.1 Pathogens ..............................................................................................6 2.2 Physical and Chemical Contaminants ....................................................7 2.3 Treatment and Classification Overview ..................................................7 2.4 Recycled Water Treatment .....................................................................9 2.5 Disinfection Methods ............................................................................10 2.6 Helminth Control ...................................................................................12 2.7 Treatment Reliability .............................................................................123 Acceptable Uses and Site Specific Controls ................................................13 3.1 Urban (Non potable) Reuse..................................................................13 3.1.1 Residential and municipal reuse with uncontrolled public access ....13 3.1.2 Municipal reuse with controlled public access..................................14 3.2 Agricultural Reuse ................................................................................14 3.2.1 Livestock ..........................................................................................14 3.2.2 Horticulture.......................................................................................17 3.3 Indirect and Direct Potable Reuse ........................................................19 3.4 Aquifer Recharge..................................................................................19 3.5 Industrial Use........................................................................................19 3.6 Fire Fighting..........................................................................................19 3.7 Water Features and Ornamental Water Bodies ....................................204 Roles, Responsibilities.................................................................................20 4.1 Suppliers...............................................................................................20 4.2 Users ....................................................................................................21 4.3 Agreements ..........................................................................................215 Safeguards and Controls .............................................................................23 5.1 Warning Signs ......................................................................................23 5.2 Distribution Reliability ...........................................................................23 5.3 Public Education ...................................................................................23 5.4 Access ..................................................................................................23 5.5 Plumbing...............................................................................................23 5.6 Irrigation Method and Design................................................................23 5.7 Spray Drift.............................................................................................23 5.8 Runoff ...................................................................................................23 5.9 Occupational Health and Safety ...........................................................23 5.10 Storage Facilities ..................................................................................23 5.11 Algae ....................................................................................................23 5.12 Mosquito Management .........................................................................236 Recycled Water Quality Management Plans................................................23 6.1 Operation and Maintenance Manuals ...................................................23 6.1.1 Contingency Plans ...........................................................................23 6.1.2 Maintenance Program.........................................................................23 6.2 Risk Management Program for Class A and A+ Schemes ....................23 6.2.1 The twelve steps of HACCP ...............................................................23Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 2 of 66
  • 36. 6.2.2 Validation ............................................................................................237. Monitoring and Reporting................................................................................23 7.1 Monitoring Program ..............................................................................23 7.1.1 Bacteriological Monitoring ................................................................23 7.1.2 Monitoring of Class A recycled water..................................................23 7.1.2.1 Cessation of Supply...................................................................23 7.1.3 Notification Limits................................................................................23 7.2 Reporting ..............................................................................................23 7.2.1 Emergency reporting........................................................................23 7.3 Auditing .....................................................................................................238 Appendices ......................................................................................................23 Appendix A: Glossary......................................................................................23 Appendix B: Application checklist....................................................................23 Appendix C: Approval Flow Chart ...................................................................23 Appendix D: List of References .......................................................................23List of TablesTable 1. Classes of Recycled Water .....................................................................8Table 2. Recommended recycled water quality (median) pre-disinfection(adapted from UWRAA, 1996) ............................................................................11Table 3: Acceptable Livestock Uses ...................................................................16Table 4: Acceptable Horticultural Uses ...............................................................18Table 5: Examples of Validation monitoring for health risks................................23Table 6: Examples of Operational Monitoring and supporting programs for healthrisks. ...................................................................................................................23Table 7: Examples of Verification monitoring ......................................................23Table 8. Microbiological notification limits for recycled water classes other thanClass A................................................................................................................50Table 9: Recycled Water Uses, Required Class, Recommended Monitoring andSite Management Controls..................................................................................52Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 3 of 66
  • 37. 1. IntroductionA combination of the current water shortages and the growing population isreducing the availability of our water supplies. Therefore, wastewatermanagement practices that protect, conserve and fully utilise water resources arevital to Western Australia.1.1 ObjectiveThe overall objective of this Guideline is to maximise the reuse of recycled waterthrough minimising and managing any risks associated with its use.These guidelines provide information for the planners, designers, installers,operators, users and regulators of recycled water systems, with the objectives of: i) Encouraging the beneficial use of recycled water and providing guidance on how this might be accomplished without negatively impacting on public health or the environment; ii) Providing guidance for the planning, design, operation and monitoring of recycled water systems in order to minimise the risks to public health; and iii) Outlining the statutory approvals needed for a recycled water reuse scheme.1.2 Scope of the GuidelinesThese Guidelines primarily deal with effluent from municipal wastewatertreatment plants treating mainly domestic and some industrial waste, as well assystem serving individual commercial premises that may generate largewastewater flows (for example hotels, motels, mining camps, schools, caravanparks etc).These Guidelines do not deal with recycled wastewater from individualhousehold systems for example sullage, greywater or effluent from septic tanks.These guidelines present a generic framework for managing water recyclingschemes, predominately focussing on Class B, C and D water recyclingschemes. Whilst these guidelines allow reuse of Class A recycled water they donot provide detail or guidance on managing the specific risks associated withClass A water recycling.The Western Australian Government supports a national approach to waterrecycling in Australia. To this end, these guidelines have been aligned with thedraft National Guidelines for Water Recycling which are being developed by theNatural Resource Management Ministerial Council and the EnvironmentProtection and Heritage Council. The draft national guidelines describe a genericprocess for development and implementation of preventative risk managementsystems for water recycling. The first phase of the national guidelines coversrecycled water sourced from sewage treatment plants as well as domesticgreywater. The second phase of the guidelines is expected to include reuse ofGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 4 of 66
  • 38. urban stormwater, aquifer storage and recovery and indirect potable use of recycled water. 1.3 Regulatory Framework The Health Act 1911 contains a number of provisions that regulate the use of recycled water Section 98 – prohibits sewage being put anywhere unless it is authorized. Section 107 – prohibits the use of any apparatus for the treatment of sewage unless approved by the Executive Director of Public Health. Section 129 – prohibits the pollution of any water supply. The Department of Environment and Conservation also regulates the use of recycled water on land under Part V of the Environmental Protection Act 1986. 1.4 Approval Process The applicant should apply in writing to the Department of Health (DOH) for the approval of any recycled water scheme and may also need to apply to the e Department of Environment and Conservation. The information required for an application should be appropriate to the scale of . r14 e241.68102.10 10 cma1.9 25 90 12169.6792431. 21Tm/F1.01Tf(e)Tj843e241.68102.10 10 cmt20 .39 2 431. 2theqQTjsT1./T1 m F10 f( )T E 1 270843proposed4e4341qQTj)f1./T0264295emc 6 .1 8 .3 1 4 m F10 T ( T E 8 3 2 1.68102.10reuse(T1./T2149.112 891 2 3 . 1 m F1eef )TjETQ93schemej)f1./T02642956mc .1 8 .3 1 4 m F10 T ( T ETQq1591(see425emc 7 9 03.521Tmappendix1/T2149xmc 1 2 3 . 1 m F .01Tf(e)TB01qQTjE 1354.71for01 cmcd list of information that may be e241.68102.10 10 e sh p ecm 0 0 0343e241.68102.10 10 10 he Tj843e241.68102.10 10 /F1.01Tf()TjETQq10 1059843e241.68102.10 10 43e241.68102.10 s p required and Appendix C for the Approvals Process Flow Chart). Before recycled water can be usede Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 5 of 66sehpehfenthhhoetttfpahiapretheello hppea
  • 39. 2. Recycled Water Quality and TreatmentThe sewerage systems we have today have been the most important contributorto our standard of living and the elimination of waterborne disease. To protectpublic health, it is important to recognise the risk factors associated with recycledwater. Human contact with recycled water creates a risk of infection from micro-organisms.The quality of wastewater varies depending on its source and the level oftreatment applied to it. The health risks from using the recycled water dependsnot only the source and the treatment systems used but also how the water isreused, how well the system is managed and the potential for human exposure.There are many ways of possible exposure to recycled water including:  Direct ingestion of recycled water, droplets or airborne particles,  Direct ingestion of food that has been exposed to recycled water,  Indirect ingestion via hand to mouth contact or ingestion of contaminated objects, and  Direct contact with recycled water.2.1 PathogensMicrobial pathogens found in effluent can be divided into three groups: bacteria,viruses and pathogenic protozoa and helminths. These pathogens can cause anumber of health complaints including vomiting, diarrhoea, respiratory illness,anaemia, hepatitis, meningitis, paralysis and eye and skin infections. Pathogenic bacteria (such as Salmonella, Campylobacter and Shigella) can be excreted by an apparently healthy population and many of the very large numbers of bacteria found in the wastewater can cause disease. Some bacteria, particularly thermotolerant coliforms (also known as faecal coliforms), are indicators of faecal contamination. Thermotolerant coliforms consist chiefly of Escherichia coli and are found in the intestinal tract of humans and other warm blooded animals. Legionella sp., the causative agent of the human form of Legionnaire’s disease, has previously been isolated from wastewater streams. Viruses (such as rotavirus, hepatitis A virus and enterovirus) derived from human faeces are present in wastewater in numbers up to 100,000 infectious organisms per litre. They can survive for long periods in recycled water systems and can be shed by healthy people. Protozoa (including Cryptosporidium and Giardia) can cause disease in humans and infective forms may be present in wastewater as cysts. Enteric protozoa, including Giardia spp, and Cryptosporidium spp., are of particular importance and can cause moderate to severe enteritis. Helminth parasites (worms) include: tapeworms or cestodes (e.g. Taenia saginata and T. solium); roundworms or nematodes (e.g. AscarisGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 6 of 66
  • 40. lumbricoides) which also includes hookworms (e.g. Ancylostoma sp. and Necator sp.), whipworms (e.g. Trichuris trichiura) and pinworms (e.g. Enterobius vermicularis); and flukes or trematodes (e.g. Schistosoma mansoni). Helminths are generally large enough to be visible to the naked eye but their ova (eggs) can be microscopic. Ova are the infective stage in the life cycle of helminths.2.2 Physical and Chemical ContaminantsThe presence of chemicals in recycled water at levels that could potentially posea health risk is not anticipated for most schemes, particularly those recyclingwater from predominately domestic sewage. Chemicals are usually onlyconsidered a health risk if Indirect Potable Reuse or Aquifer Recharge isproposed (see table 1).Chemicals entering the sewerage system are managed through trade wastecontrol, substantially diluted in other waste and generally removed or degradedby treatment processes. Therefore, chemicals of health concern are usuallyorders of magnitude below the levels either permitted in our drinking water supplyor routinely consumed through dietary exposure. For this reason, specific waterquality objectives for heavy metals and organic contaminants have not beenestablished. For irrigation of agricultural crops, reference should be made toSection 9.2 of the Australian and New Zealand Guidelines for Fresh and MarineWater Quality, Volume 3, Primary Industries - Rationale and BackgroundInformation (Chapter 9).However, for schemes where industrial or trade waste inputs are significant,specific management controls may be required.2.3 Treatment and Classification OverviewThe classification criterion for recycled water is provided in Table 1. As describedin this Table, recycled water is classified into five “Classes” (A+ to D), principallyon the basis of:  Generic categories of treatment processes known to result in particular levels of pathogen reduction required for a range of end uses;  Physical-chemical water quality (for example, turbidity and biochemical oxygen demand (BOD)) and E.coli which are designed to ensure optimal performance of the treatment processes (including disinfection where required) and provides a mechanism for monitoring performance; and  Adoption of a specific measure known to remove pathogens that may otherwise not be adequately controlled under the above process provisions (such as, Helminth removal which required lagoon storage or filtration prior to reuse).Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 7 of 66
  • 41. Table 1. Classes of Recycled Water Recycled Water Quality TreatmentClass Range of Uses12 Objectives1 Process2  Turbidity < 2 NTU6  < 10 / 5 mg/L BOD / SS  pH 6 – 9 7  1 mg/L Cl2 residual (or equivalent disinfection)8  Secondary2 Indirect Potable Reuse11  Filtration3 Aquifer Recharge11  <1 E.coli per 100 mL  Disinfection4 A+  <1 helminth per litre  Advanced Firefighting: eg potential for  < 1 protozoa per 50 litres treatment5 worker saturation and first aid  < 1 virus per 50 litres treatment of burns victims  <2-10mg/L nitrogen  Meet DOH Chemical Guidelines for Recycled Water  Turbidity < 2 NTU6  < 10 / 5 mg/L BOD / SS Urban (non-potable): with  pH 6 – 9 7 uncontrolled public access  1 mg/L Cl2 residual  Secondary2 Agricultural: eg human food (or equivalent disinfection)8 A  Filtration3 crops consumed raw with  Disinfection4 edible parts exposed to  <10 E.coli per 100 mL recycled water  <1 helminth per litre Industrial: open systems with  < 1 protozoa per 50 litres worker exposure potential  < 1 virus per 50 litres Agricultural: eg dairy cattle  <100 E.coli org/100 mL  Secondary2 7 grazing with unrestricted B  pH 6 – 9 and pathogen irrigation method  < 20 / 30 mg/L BOD / SS10 reduction9 Industrial: eg washdown water Urban (non-potable): with controlled public access Agricultural: eg human food crops cooked/processed,  Secondary2  <1000 E.coli org/100 mL grazing/fodder for livestock, and pathogen C  pH 6 – 97 human food crops consumed reduction9  < 20 / 30 mg/L BOD / SS10 raw edible part, not exposed to recycled water or sub surface irrigation Industrial: systems with no potential worker exposure  <10000 E.coli org/100 mL Agricultural: non-food crops D  pH 6 – 97  Secondary2 including instant turf, 10  < 20 / 30 mg/L BOD / SS woodlots, flowers1. Unless otherwise noted, recommended quality limits apply to the recycled water at the point of discharge from the Wastewater Treatment Plant (WWTP)2. Secondary Treatment processes include activated sludge processes, trickling filters, rotating biological contractors, and may include stabilization ponds and ponds based waste water treatment plants.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 8 of 66
  • 42. 3. Filtration means the passing of recycled water through natural undisturbed soils or filter media such as sand and/or anthracite, filter cloth, or the passing of recycled water through micro-filters or other membrane processes.4. Disinfection means the destruction, inactivation, or removal or pathogenic microorganisms by chemical, physical, or biological means.5. Advanced recycled water treatment processes include chemical clarification, carbon adsorption, reverse osmosis and other membrane processes, air stripping, ultrafiltration, and ion exchange.6. Turbidity limit is a 24-hour median value measured pre-disinfection. The maximum value is five NTU. th7. pH range is 90 percentile. A higher upper pH limit for lagoon-based systems with algal growth may be appropriate, provided it will not be detrimental to receiving soils and disinfection efficacy is maintained.8. Chlorine residual limit of greater than one milligram per litre after 30 minutes (or equivalent pathogen reduction level) is suggested where there is a significant risk of human contact or where recycled water will be within distribution systems for prolonged periods.9. Helminth reduction is either detention in a pondage system for greater than or equal to 30 days, or by a DOH approved disinfection system (for example, sand or membrane filtration).10. Where Class C or D is via treatment lagoons, although design limits of 20 milligrams per litre BOD and 30 milligrams per litre SS apply, only BOD is used for ongoing confirmation of plant performance. A correlation between process performance and BOD / filtered BOD should be established and in the event of an algal bloom, the filtered BOD should be less than 20 milligrams per litre.11. Draft guidelines are presently being prepared, however it is likely to be some years before a scheme will be approved. Significant research is currently being undertaken in this area.12. It is assumed that heavy metal and other contaminant levels are not of concern, or that they comply with relevant guideline values in NWQMS document.13. Refer to Tables 3 and 4 for specific permitted livestock and horticultural uses.2.4 Recycled Water TreatmentThe level of treatment required depends on the proposed use. The broadcategories are:  Primary treatment: this is the initial treatment which involves screening and sedimentation to remove gross and settleable solids.  Secondary treatment: this is the minimum standard required for most agricultural and municipal recycled water schemes.Secondary treatment follows primary treatment and is typically regarded as lowrate stabilisation processes such as facultative lagoons or biological/mechanicaltreatment such as biofiltration, trickling filter, intermittently decanted extendedaeration (IDEA) or activated sludge plants.Detention in a multiple lagoon system for 20-25 days should provide effluentcontaining less than 1000 thermotolerant coliforms/100mL while more than 60days could be required to remove intestinal protozoa and viruses. Longerdetention time may be required for cooler climates.  Tertiary treatment: this is the treatment of recycled water beyond the secondary biological stage. It normally implies the removal of a high percentage of suspended solids and/or nutrients through additional filtration processes such as membrane filtration followed by disinfection.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 9 of 66
  • 43. Source ControlIt is important to control the inputs of pollutants into the source water. Allsewerage service providers who are considering water recycling should havetrade waste agreements with their industrial and commercial customers thatcontain provisions for continuous improvement in environmental performanceover time.2.5 Disinfection MethodsDisinfection of the recycled water is the most important part of the treatmentprocess to protect public health. Generally disinfection is the final step in thetreatment process. The level of disinfection required depends on the intendedfinal use of the recycled water and the likely level of human contact. Disinfectionmethods should include standby systems, automatic alarms, effectivemaintenance and quality assurance programs.Disinfection of recycled water is achieved using a variety of methods, including: - chemical (for example, chlorination, ozonation); - physical (for example, ultraviolet radiation, microfiltration); and - biological (for example, detention lagoons).There are two key control steps for producing recycled water, which dependingon the end uses, will be of sufficient quality that it poses no unacceptable risk tohuman health, livestock or the environment. 1. The first control step is the adequate pre-treatment of the effluent to ensure that selected disinfection processes work efficiently. Table 2 provides indicative recycled water quality criteria required to ensure effective pathogen reduction for each disinfection method. These values may vary depending on other recycled water qualities and as such are only a guide. 2. The second control step is to ensure that the actual disinfection produces an effluent meeting the required quality standards. The primary indicator used to assess the efficacy of the disinfection process is the concentration of E.coli bacteria. It is important that the use of E.coli is not taken out of context, as it has been well documented that there can be poor correlations between E.coli levels and the concentrations of pathogenic organisms.E.coli is used as an indicator of the treatment/disinfection efficiency. Whencoupled with other treatment process indicators (BOD for example), specifictreatment methods, and direct verification of pathogen removal (for Class Areuse schemes) the result is an integrated measure of effluent quality.Thermotolerant coliforms (of which E.coli are a major component) are also usedas a treatment process indicator. However, E.coli is the DOH preferred indicator.Where thermotolerant coliforms are used, the E.coli criterion is applied directly asthe thermotolerant coliform limit.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 10 of 66
  • 44. Table 2. Recommended recycled water quality (median) pre-disinfection(adapted from UWRAA, 1996)Disinfection SS BOD Turbidity Nitrate Ammonia pH Method (mg/L) (mg/L) (NTU)1 (mg/L) (mg/L)2Chlorination <20 <20 <10 NA See note 6.0-9.0 2 Ozone <10-15 <20 <5 Maximised <1 6.0-9.0 UV3 <10 <20 <5 Maximised NA NAMicrofiltration NA NA <10 NA NA Neutral Detention NA NA NA NA NA Neutral Lagoons1. If a significant reduction in the number of pathogens is required (that is, less than ten E.coliorganisms per 100 millilitres), the turbidity of the pre-disinfected recycled water should be lessthan two NTU (median) for any method.2. Presence of ammonia with chlorine causes chloramination, which is a less effective disinfectionmethod than chlorine; however, formation of toxic by-products is minimised. The required level ofammonia, therefore, depends on whether chloramination or chlorination is the disinfectionprocess.3. The transmission capacity of the recycled water is the most important parameter affecting thedisinfection efficiency of UV and should be greater than six.LagoonsThe storage of secondary treated recycled water in pondage systems (nominally30 days) allows natural disinfection to take place before discharging or reusingthe treated recycled water. Natural disinfection can occur via sunlight and/ornatural microbial die-off.Natural disinfection processes can be affected by a number of factors such asthe:  turbidity of the recycled water, as it affects sunlight penetration;  amount of suspended matter in the water, as viruses and bacteria may be shielded from the rays of the sun by being absorbed into surface pores;  ineffectiveness of sunlight in seawater compared with freshwater, and  dense plant growth on the surface (eg duckweed).Temperature, pH, adsorption and sedimentation further influence the naturaldisinfection and inactivation processes occurring in recycled water stored inlagoons. The ability of ponds to remove or reduce the number of pathogensdepends on such factors as the load of incoming solids and microorganisms,temperature, sunlight and pond design related to detention time.Algal blooms in the ponds over summer will also reduce the efficiency of thenatural disinfection process.Systems using only detention do not typically result in a Class A effluent and areunsuitable as the sole means of pathogen reduction for high contact uses.Detention can be used to achieve a Class C effluent.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 11 of 66
  • 45. 2.6 Helminth ControlHelminths are parasitic worms that are transmitted to humans through contactwith contaminated soil containing faeces. The most common method ofexposure is from walking barefoot on the soil where the eggs (ova) and larvaecan be present. Helminths are endemic to the Kimberley region, north of the 20thparallel.Helminth control is necessary in the following locations: - north of the 20th parallel to irrigate public open spaces (parks, sports fields and municipal areas) and - where the recycled water is used to irrigate pasture and fodder for beef cattle; or - where the recycled water is used to irrigate pasture and fodder for dairy animals; or - where the recycled water is used for drinking water for stock (except pigs, see section 3.2); or - where the recycled water is used to wash down water for dairies.Conventional primary and secondary treatment processes, including disinfectionvia chlorination or UV, may not ensure adequate removal of helminths such asintestinal nematodes. The specified treatment measures to reduce helminthsnumbers are:  at least 25 days detention in treatment lagoons (this may include either primary, secondary or maturation lagoons provided the helminth settling process is not disturbed by processes such as mixing, aeration or any other process) or a storage facility where all recycled water must be detained for at least 30 days from the time of the last discharged into the storage facility, or  an approved method of filtration, such as sand or membrane filtration.2.7 Treatment ReliabilityGenerally, a higher quality of recycled water requires a greater importanceplaced on treatment reliability measures. The following measures should beconsidered to improve treatment reliability:- minimise the concentrations of potential contaminants entering the sewer through a trade waste management program (for example, generators having waste management plans or cleaner production programs);- adoption of QA systems;- duplicate and/or provide standby facilities for power, treatment units, pumps and disinfection systems;- flexible modes of operation;- independence of multiple treatment processes or barriers;- alarm systems and automatic controls;- appropriately trained and experienced operators;- effective inspection, maintenance and monitoring programs;- contingency plans such as diversions for noncompliant events and emergencies (for example, unacceptable recycled water quality, treatmentGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 12 of 66
  • 46. plant and disinfection system failures, transfer pipeline bursts, illegal waste discharges, overflows or spills); and- provision for emergency storage.3 Acceptable Uses and Site Specific ControlsRecycled water must be treated to a level that is “fit for purpose”, that is,recycled water must be treated to a level that is suitable for its end use.The level of treatment that is required depends on the final application of therecycled water. Where there is limited exposure to the general public andcontrols and safeguards can be applied, lower levels of treatment may be used.Conversely, where there will be more direct contact by the general public with therecycled water and safeguards are not strictly enforceable, higher levels oftreatment will be needed.3.1 Urban (Non potable) ReuseRecycled water is suitable for a range of urban non potable uses. The potentiallevel and likelihood of exposure to recycled water determines the Class that issuitable. The potential level of exposure is influenced by a number of factorsincluding:  the distance from residential areas,  the use of signage and/or fencing to restrict site access,  the irrigation method used, and/or  the use of restricted watering times (for example night time watering).3.1.1 Residential and municipal reuse with uncontrolled public accessClass A recycled water must be used for residential or municipal reuse schemeswhere there is limited control of public access and therefore a potentially higherexposure of the recycled water to humans. This includes residential schemes forgarden watering, toilet flushing and third pipe systems.The following is a list of Class A recycled water uses considered acceptable froma human health perspective, however other issues and controls are relevant,such as environmental and plumbing controls.  Irrigation of public open spaces, such as parks, sports fields and municipal areas, where public access is unrestricted and any irrigation method can be used.  Domestic garden watering, including vegetable gardens  Toilet flushing  Washing machine use (dedicated cold connection tap only)  General outdoor uses such as car washing, construction and wash down.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 13 of 66
  • 47.  Filling water features and ornamental ponds that are not used for swimming.  Industrial and commercial uses including construction, wash down, dust suppression, use in cooling towers and toilet or urinal flushing.(Refer to Table 1. Classes of Recycled Water)Class A recycled water is not acceptable for the following uses;  drinking  cooking or other kitchen purposes  bathing or showering  filling swimming pools and spas.3.1.2 Municipal reuse with controlled public accessMunicipal reuse includes the irrigation of open spaces, parks, sportsgrounds, golfcourses, median strips etc. Class B and C recycled water may be used formunicipal schemes provided public access can be controlled.Controlled public access means that the recycled water user must maintaineffective control over public access to the areas being irrigated. The mostcommon method of controlling public access is by night time irrigation. Nighttime irrigation is not to commence before 9.00pm and must cease at least onehour before sunrise and to provide a withholding period of nominally 4 hours oruntil the irrigated area is dry. Night time watering should not be the only methodof restricting access employed. Additional methods such as simple non-continuous barriers that direct the public towards signage or fencing with lockablegates may also be required. (See section 5.6 also)3.2 Agricultural Reuse3.2.1 LivestockBeef CattleIf cattle are exposed to untreated sewage or wastewater, the human tapewormTaenia saginata can develop into the parasitic cysts (Cysticercus bovis) or “beefmeasles”. Consumption of contaminated, poorly cooked meat by meat byhumans would then result in the tapeworm infestation and an established cycle ofinfection.The grazing of cattle on pasture or fodder irrigated by Class C recycled water(including helminth reduction) requires a withholding period of four hours or untilthe pasture or fodder is dry.Only recycled water that has had a helminth reduction process (that is aminimum of 30 days pondage or an approved method of filtration) may be usedfor a scheme involving cattle grazing. Without adequate treatment andmanagement, helminths in sewage applied to grazing land have potential toGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 14 of 66
  • 48. establish cycles of infection between humans and animals (such as Taenia ortapeworms in humans and pigs, and Cysticercosis or “beef measles” in cattle).Consumption of contaminated and uncooked meat by humans can completeinfection cycles from animals back to humans.PigsPigs must not be fed or exposed to any pasture of fodder produced or irrigatedwith recycled water. Pigs must also not be allowed to drink any recycled water.No treatment standard has been approved for pigs.This restriction reflects that Taenia solium (a helminth with pig-human lifecycle),which can cause severe neurological disease in people. Although pork measles(Cysticercosis) has not been detected in Australia, the tapeworm is known toaffect some people who have lived or visited overseas, and it is important thatexposure to pigs is prevented.Dairy AnimalsThe grazing of dairy animals on pasture or fodder irrigated with Class B(including helminth reduction) recycled water requires a minimum withholdingperiod of four hours or until the pasture or fodder is dry. If Class C recycledwater (including helminth reduction) is used, then a withholding period of fivedays is necessary.Recycled water should not be used as wash down for milking machinery.Class B (including helminth reduction) is the minimum quality required if dairyanimals are to drink recycled water.Fodder or pasture for Grazing AnimalsClass C is the minimum quality required for the grazing of sheep, horses, goatsetc on pasture or fodder irrigated recycled water. Helminth reduction is notnecessary.A withholding period of four hours or until the pasture or fodder is dry must alsobe achieved.If fodder is to be sold, growers should ensure that is to be fed to livestockappropriate to the class of recycled water used for irrigation. This assurancecould be achieved through only selling the fodder to defined users, or if thefodder is for a broader market, labelling with the relevant prohibitions (forexample, “recycled water irrigated fodder not fit for consumption by pigs”).Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 15 of 66
  • 49. Table 3: Acceptable Livestock Uses Minimum Irrigation Key management controls for Reuse category water method use eg. withholding period Class Livestock Irrigation of pasture Class B Unrestricted Withholding period of 4 hours and fodder for (including before pasture use, dry or ensile dairy animals helminth fodder. reduction) Washdown water not to be used for milking machinery. Controls to ensure pigs are not exposed to pasture or fodder. Class C Unrestricted Withholding period of 5 days (including before pasture use, dry or ensile helminth fodder. reduction) Controls to ensure pigs are not exposed to pasture or fodder. Irrigation of pasture Class C Unrestricted Withholding period of 4 hours and fodder for beef (including before pasture use, dry or ensile cattle helminth fodder. reduction) Controls to ensure pigs are not exposed to pasture or fodder. Irrigation of pasture Class C (no Unrestricted Withholding period of 4 hours and fodder for helminth before pasture use, dry or ensile sheep, goats, reduction fodder. horses, etc necessary) Controls to ensure pigs are not exposed to pasture or fodder. Livestock drinking Class B - Washdown water not to be used water or washdown for milking machinery. water for dairy Recycled water with a blue green sheds. algae bloom not suitable for stock drinking. Pigs not to come into contact with recycled water.Note: it is assumed that heavy metal and other chemical contaminant levels are not a concern, or that they comply withrelevant guideline values in NWQMS.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 16 of 66
  • 50. 3.2.2 HorticultureWhen recycled water is to be used for human food crops the required waterquality depends on:  the potential for the edible portion of the crop to come into direct contact with the recycled water. This reflects both the irrigation method and the crop involved (that is, whether the produce is grown in contact with the soil or the produce has a protective and inedible covering), and  the level of processing or cooking of the food prior to consumption.Food crops that are consumed raw and are likely to be in direct contact withrecycled water, must be irrigated with Class A recycled water only.Food crops that will be either cooked at greater than 70 0C for two minutes, orprocessed (such as cereals, wheat, grapes for wine production, etc) prior to saleto the domestic market, may be irrigated with Class C recycled water.Food crops that are not in direct contact with recycled water such as fruit treesmay be irrigated with Class C recycled water.Class D recycled water is not suitable for use with human food crops.Recycled water must not be used for washing or packaging of food afterprocessing for sale or distribution. Recycled water must also not be used forwashdown water for food packaging or processing machinery.The Commonwealth Department of Agriculture, Fisheries and Forestry hasproduced Guidelines for On-farm Food Safety for Fresh Produce (AFFA, 2001)that provide a single consolidated source of information relating to on-farm foodsafety for fresh produce crops. They are designed to help assess the risks offood safety during on farm production of fresh crops and provide information ongood practice to prevent, reduce or eliminate the hazards, including the risk ofcontaminating produce when using water.Non food crops such as cotton, trees, woodlots, turf farms and wholesale plantnurseries that can be irrigated in areas where public access can be excludedmay use Class D recycled water, provided appropriate occupational safety andhealth requirements are adhered to.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 17 of 66
  • 51. Table 4: Acceptable Horticultural Uses Minimum Key management controls Irrigation Reuse category water for use eg. withholding method Class period Raw human food crops exposed to recycled water Crops grown close to the ground and consumed Class A Unrestricted raw (eg. celery, cabbage) Root crops consumed raw (eg. carrots, onions, Class A Unrestricted radish) Human food crops cooked (>70° for 2 minutes) or pr ocessed before human C consumption, or consumed raw but with edible parts not exposed to recycled water Crops grown over 1 Class A Unrestricted metre above the ground and eaten raw (eg. Flood, apples, pears, apricots, Dropped produce not to be Class C furrow, drip, harvested table grapes, olives) sub-surface Class A Unrestricted Crops which are skinned, peeled or shelled before Produce should not be wet consumption (eg. nuts, Flood, from recycled water watermelons, Class C furrow, drip, irrigation when harvested. rockmelons) sub-surface Dropped produce not to be harvested. Crops to be cooked (>70°C for 2 minutes) or Produce should not be wet processed before sale to Class C Unrestricted from recycled water consumers* (eg. wheat, irrigation when harvested wine grapes, potatoes, beetroot) Non food crops Crops not for Restrict public access to consumption (eg. application area. Harvested Class D Unrestricted woodlots, turf growing, products not to be wet from flowers) recycled water when sold* Crops that are cooked prior to consumption can be sold uncooked to consumers provided thesafety of the practice (such as considering the irrigation steps, preparation prior to sale anddomestic cooking) can be demonstrated to the satisfaction of relevant Government agencies, theDOH for example.Note: 1. The health risks associated with hydroponics has not been adequately assessed,therefore hydroponic crops consumed raw must currently use Class A recycled water.2. It is assumed that heavy metal and other chemical contaminant levels are not a concern, orthat they comply with relevant guideline values in NWQMS.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 18 of 66
  • 52. 3.3 Indirect and Direct Potable ReuseThere is currently not enough information available to develop generic guidelinesfor the use of recycled water as a direct or indirect potable water source.Proposals under these categories will need to be assessed on a case by casebasis. Draft guidelines are currently being investigated, however it is likely to besome years before a scheme will be approved.3.4 Aquifer RechargeAquifer recharge involves the recharge of aquifers with recycled water for storageand later use. For information on aquifer recharge please see the DOHRecycled Water - Groundwater Recharge Guidelines in the EnvironmentalProtection Authority Section 16(e) advice on Managed Aquifer Recharge atwww.epa.wa.gov.au.3.5 Industrial UseRecycled water may be used for a range of industrial processes such as:  cooling water make up water,  boiler feed water,  process water,  washdown water,  fire protection, and  dust control/suppression at construction sites, quarries and mines etc.When considering the use of recycled water in industrial process considerationmust be given to the quality of the water and the protection of the process and/ormachinery. For example the nutrients in the water may cause slime formationand microbial growth, while the suspended solids could cause blockages andfouling. The Australian and New Zealand Guidelines for Fresh and Marine WaterQuality (ANZECC, 2001) provides guidance on appropriate water quality for arange of industrial uses.If the recycled water is to be used in an “open system” where there is a potentialfor workers to be exposed, Class A recycled water must be used. This includesrecycled water used for dust suppression where workers and passing cars maybe subject to spray drift or direct wetting.If the recycled water is to be used in a “closed system” then Class C recycledwater may be used however this is subject to the need for additional treatment toprevent fouling, scaling, corrosion, foaming or biological growth within pipe work.3.6 Fire FightingWhere possible, fire fighters need to have access to high quality water becausethe water they use to fight fires often saturates them, they ingest aerosols fightinga fire and water from fire hoses is sometimes used in first aid treatment of burnsGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 19 of 66
  • 53. victims at the scene of the fire. In urban areas the highest quality water issupplied through the reticulated potable water system.Use of Class A+ recycled water for fire fighting represents a negligible health riskfor fire fighters (WSAA 2004). This is because the high level of treatment of ClassA+ recycled water removes pathogens to such an extent that the likelihood of anyhealth impact on fire fighters, given their infrequent exposure, would benegligible. Also, although there can be trace chemical residues in Class A+recycled water (unpublished EPA data), the levels are so low that occasionalexposure from fire fighting would not be expected to present a health hazard tofire fighters.3.7 Water Features and Ornamental Water BodiesDetermination of the appropriate class of recycled water for fountains andornamental water bodies should only take place after an appropriate assessmentof the risks of human contact has been undertaken. Amongst the factors thatshould be considered are the likelihood and frequency of human exposure torecycled water, the effectiveness of disinfection, the extent of aerosol generationand the prominence and wording of signage. For example, where there is alikelihood of human contact with the water (e.g. wading on hot days or occasionalaccidental ingestion of water) it may be appropriate to use only Class A recycledwater. If there is certainty about no human contact (e.g. no physical access or noaerosol generation) class B or C recycled water could be used.4 Roles, ResponsibilitiesRecycled water suppliers and users have responsibilities to ensure that therecycled water used causes no adverse impact on public health.4.1 SuppliersUltimately it is the suppliers responsibility to ensure that the reuse scheme ismanaged and operated in accordance with the DOH conditions of approval andthis guideline. It is also the ultimate responsibility of the supplier of the recycledwaste to ensure that the scheme has the necessary approvals from the DOH andDEC, if required to operate.Suppliers of recycled water have the following responsibilities:  Deliver recycled water to the user that is of a quality fit for its intended purpose. To ensure the quality is maintained the supplier should develop and maintain an effective quality management system including documented standard operating procedure, training schemes and manuals, and a written log. The log should contain details of standard operating procedures, all audit checks, and include system failures and violations, and details of corrective action taken both at the time and to prevent recurrences.  Ensure the entire system for producing and using the recycled water, including each site where recycled water is used is covered by a Recycled Water Quality Management Plan (see section 6).Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 20 of 66
  • 54.  Ensure that all schemes claiming water from their premises (i.e. the users) are approved by the DOH to use the water.  Provide each user with relevant information about recycled water in regards to human health.  Keep a register of all users to which they supply the recycled water.  Negotiate an agreement of supply with all users (see section 4.3) and keep to the terms of the agreement.  Alert each user if any problems relating to the quality or supply occur as soon as practicable.  Participate in audits conducted by the DOH.  Notify the DOH if they become aware of any misuse of the recycled water by the user. This may involve terminating supply to that user.4.2 UsersUsers of recycled water have the following responsibilities:  Adhere to the conditions of approval set by the DOH.  Adhere to the terms of the Agreement of Supply entered into with the Supplier (see Section 4.3).  Regularly inspect the system to ensure it is operating correctly.  Provide employees with appropriate and up to date training and education on the hazards of recycled water and personal protective equipment.  Ensure that only suitably trained personnel operate the recycled water system and that appropriate health and safety measures and procedures are in place to protect operators and any others exposed to the recycled water.  Inform all visitors and employees to the irrigation site of the use of recycled water  Keep a register of complaints  Maintain the site and system so that the recycled water does not pose a public health risk.  Participate in audits conducted by the DOH  Notify the DOH and the supplier of any exceedences or incidents.4.3 AgreementsA recycled water supply agreement must be made between the supplier and theuser of the recycled water. A recycled water supply agreement ensures bothparties know their responsibilities.The agreement should include:  obligations and responsibilities of supplier and user,  recycled water characteristics (source, quality, quantity, pressure, flow variations),  responsibility for operation, maintenance, monitoring and auditing processes,  restrictions on use,  reliability of supply,Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 21 of 66
  • 55.  liabilities and insurance,  financial arrangements,  contract duration and conditions for termination,  ownership of facilities.  contingency measures should problems arise.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 22 of 66
  • 56. 5 Safeguards and ControlsSafeguards and controls are necessary to avoid potential risks to publichealth. The safeguards and controls required will depend on the recycledwater quality and recycled water end use.5.1 Warning SignsWherever recycled water is being used, erect prominent warning signsindicating, in English and any other primary languages predominately spokenin the area:“RECYCLED WATER – DO NOT DRINK – AVOID CONTACT”Warning signs should be designed with reference to AS 1319 (Safety signs forthe occupational environment 2004) and AS 2416 (Design and application ofwater safety signs 2002).Signs must be a minimum size of 20cm x 30cm on a white background withblack lettering of at least 20mm in height. The sign should also contain therecommended International Public Information – Drinking Water Symbol withthe Prohibition Overlay in RED. All signs should be in compliance withAS1319 – 1994 Safety Signs for the Occupational Environment. The numberof signs and size of wording should be determined on the basis of the visualdistance from the observer.In addition to the irrigation area, individual fixtures and points of access to therecycled water system should have warning signs.All recycled water ponds, dams and tanks should also be clearly sign posted.The wording of these signs should state “WARNING – RECYCLED WATER –DO NOT DRINK OR SWIM”.Variations of wording and colour may be acceptable provided they areappropriate to the possible exposure route, check with the Department ofHealth.5.2 Distribution ReliabilityTo improve distribution reliability, distribution systems (including all pipe work,fittings and drainage of the recycled water) should be designed:- in accordance with AS/NZS 3500 series - National Plumbing and Drainage Standards and other relevant Australian Standards;- to ensure the separation and prevention of cross connection between recycled water and potable water systems; and- to allow the disinfection or slug dosing of distribution pipe work with disinfectant or algicide to control biological solids and bacterial re-growth. (The discharge of recycled water drained or scoured from theseGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 23 of 66
  • 57. procedures should, where practicable, be to land or back to the treatment and/or storage facilities).5.3 Public EducationAn early, open, and thorough public awareness effort on the part of entitiesutilizing recycled water is very effective in diminishing the fears and suspicionsfrequently encountered when considering the use of recycled water.To promote consumer acceptance of recycled water, the DOH recommendsthat the public be continually informed, especially potential users, of projectstatus as regulatory and infrastructure decisions are being formulated. Thisshould aid in the public’s understanding of the safeguards and rigorousconsideration the project is being given and will provide a sense ofinvolvement and inclusion.Key messages should include;  appropriate/acceptable uses of recycled water  inappropriate or potentially unsafe uses of recycled water  the risks of inappropriate uses of recycled water  the identification of the recycled water infrastructure versus the drinking water infrastructure  the responsibilities of the recycled water users, for example: - using recycled water appropriately and responsibly - advising visitors of appropriate uses of recycled water - undertaking cross connection tests - maintaining recycled water infrastructure on own property  where to get further information and advice.For in house use of recycled water the supplier should provide all potentialresidential customers with user-friendly materials and guidance (for example afact sheet or frequently asked questions) about the third pipe scheme.Information that should be supplied to residential users includes:  the customers’ responsibilities in using the recycled water,  the use of only licensed plumbers for installation and maintenance of the recycled water systems,  the suppliers right to enter the customers’ property for checking and testing for cross connections and taking meter readings,  the customers use of recycled water in a safe and responsible manner consistent with the suppliers guidance information and DOH guidelines,  the ongoing management of the third pipe scheme including periodic testing for cross connections with the drinking water supply,  a list of permitted uses including: watering of gardens and lawns, toilet flushing, washing of cars and boats on lawns,  a list of uses not permitted including: human drinking water, washing of driveways, and washing of cars and boats on surfaces having direct discharge to stormwater drains,Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 24 of 66
  • 58.  guidance on safe and efficient use of recycled water including tips on good practice garden watering and maintenance of healthy plants with the recycled water, and  what to do and who to contact in emergencies (for example pipe failure).5.4 AccessAccess control to the recycled water irrigation area may be required for thepublic and/or livestock.No restriction of public access is required when the recycled water is Class Aor when sub-surface irrigation (a minimum depth of 150mm below the groundsurface) is used.When using Class B, C or D public and livestock access must be restricted.The level of access control will depend on the Class of recycled waterirrigated.Class C recycled water must have “controlled public access”. This meansthat the recycled water user must maintain effective control over public accessto the areas being irrigated. The most common method of controlling publicaccess is by night time irrigation. Night time irrigation is not to commencebefore 9.00pm and must cease at least one hour before sunrise and toprovide a withholding period of nominally 4 hours or until the irrigated area isdry. Night time watering should not be the only method of restricting accessemployed. Additional methods such as simple non-continuous barriers thatdirect the public towards signage or fencing with lockable gates may also berequired.5.5 PlumbingAll pipework associated with recycled water schemes should be installed inaccordance with AS/NZS 3500 (Plumbing and Drainage Code; StandardsAustralia, published in parts from 1996 to 2003), whereas dual-reticulationsystems should be installed in accordance with the relevant supplement to theWater Supply Code (WSAA 2002b).A fundamental requirement in all recycled water schemes is maintainingseparation from drinking water systems or from potential sources of drinkingwater. To protect public health, it is essential that direct connection of recycledwater systems to drinking water supplies is not permitted. If drinking water issupplied as make-up water or as a supplementary source of water, anapproved air gap or backflow prevention device must be installed, as specifiedby AS/NZS 3500 (Plumbing and Drainage Code; Standards Australia,published in parts from 1996 to 2003).Complete pipe work plans should be maintained and updated to provide apermanent record of the location and depth of the recycled water pipes.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 25 of 66
  • 59. Recycled water pipes installed as a part of an irrigation system should complywith AS2698.2 Plastic Pipes and Fittings for Irrigation and Rural Applications.All pipework should be marked as indicated in AS/NZS 3500 (Plumbing andDrainage Code; Standards Australia, published in parts from 1996 to 2003)and the Water Supply Code (WSAA 2002b).Where possible, public access to valves and fittings should be prevented, andall such facilities should be distinctly marked and labelled (eg ‘Warning —recycled water — not for drinking’). Outlets and taps should also be clearlymarked.5.6 Irrigation Method and DesignThe type of irrigation method can influence the Class of recycled water that isused and the extent of public access control required. The method ofirrigation can also affect the design of runoff controls that may be needed.The recycled water quality limits in Table 1 are based on spray irrigation. Alesser quality may be approved if application methods such as sub-surface,trickle or micro-irrigation systems are used. It will need to be demonstratedthat public health will be adequately protected and no runoff occurs.In the case of horticulture the irrigation system must be designed so that thecorrect amount of recycled water is applied at the right time to meet the croprequirements, and to ensure that runoff and percolation are minimised asmuch as possible.In planning an irrigation system a water balance should be established todetermine the maximum volume of recycled water which could be sustainablyutilised per year, on average, by the receiving crop type.Irrigation pipes should be capable of being drained or flushed to allowodorous recycled water or decomposing matter to be run to waste beforebeginning any application. This is particularly important after the system hasnot been in used for an extended period of time (eg after the winter period)and recycled water has sat in pipes or when the recycled water does notcomply with the prescribed standard and must not be used.5.7 Spray DriftSpray drift should be minimised when using Class A recycled water howeverthere are no specific restrictions.When using Class B, C or D recycled water spray drift into areas of publicaccess must be minimised. This may be achieved by using some of thefollowing methods:  buffer zones,Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 26 of 66
  • 60.  tree/shrub screens,  selection of large droplet design sprays,  choice of spray height,  anemometer switching systems, and  not irrigating in weather conditions that would cause spray drift.Spraying of public drinking fountains, natural or artificial water bodies,buildings, playgrounds, and barbeque and picnic areas is not permitted.Where spray irrigation is used, establish buffer zones from the edge of theirrigation area to the nearest dwellings or public areas where contact with therecycled water could be likely.The required buffer zone will vary depending on the methods employed tominimise drift. However, the standard buffer zones required are as follows:  30 meters for Class B  50 meters for Class C  100 meters for Class DWind direction and speed should be monitored continuously and the systemshut down if speed or direction becomes a concern, some schemes mayrequire anemometer switching systems.5.8 RunoffIrrigation systems should be installed and operated so that surface runoff andponding does not occur.The nutrients in treated recycled water can potentially cause pollution ofgroundwater and surface water and a reduction in soil quality if the treatedrecycled water is over-used. Over-use can mobilize the nutrients into thegroundwater and local wetlands. This could cause algal blooms in lakes andrivers. Avoiding over-watering will also minimise runoff and reduces theamount of water that reaches the groundwater table. For this reason,irrigation should be turned off when it rains.To reduce runoff:  Irrigation should only be conducted under dry weather conditions.  Choose an irrigation site that: - has a slope of no more than 10% - has permeable, well drained soil, - provides adequate protections for groundwater, and - is not prone to frequent flooding.  Apply recycled water in accordance with the vegetation requirements. The volume of water applied should not exceed that used by the crop or lost via evaporation or deep drainage to prevent waterlogging within the rootzones, so that a ‘water balance’ is achieved.  Diversion drains upslope may be required to control the flow of stormwater onto the site.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 27 of 66
  • 61. 5.9 Occupational Health and SafetySuppliers and users of recycled water schemes should ensure that onlysuitably trained personnel operate the treatment and irrigation system and thatappropriate health and safety measures and procedures are in place toprotect operators and any others exposed to recycled water. Employersshould make themselves aware of their responsibilities and duties under theOccupational Health and Safety Act 1984The employer is responsible for ensuring: Training and education is provided on the hazards of recycled water and sewage. Access to clean water and soap for washing hands. Access to disinfectant and dressings for wounds, cuts or lacerations that occur during work hours. The right personal protective equipment (PPE), such as gloves, goggles, a face shield, water-resistant suit, or respirator depending on the job. Clean areas set aside for eating and smoking. Access to cleaning facilities or services for clothing and equipment.Simple preventative mechanisms can reduce the risk of contamination and thepotential for infection. To avoid infection: Practice a high level of personal hygiene. Thoroughly wash hands before eating, drinking and smoking. Cover cuts and abrasions with gloves or a waterproof dressing. Disinfect and dress skin wounds, cuts and lacerations that occur as soon as possible. Don’t work on active sprinklers or a pressurised system. Don’t drink water from the irrigation system. Consider vaccination. Vaccination is recommended for Hepatitis A only for workers that have ongoing exposure to recycled water. For contractors and others with short-term exposure, vaccinations may not be as successful as good hygiene practices due to the delayed effects between immunisation and immunity. Contact your local GP to discuss the recommended vaccinations. Ensure staff received regular training in safe work and hygiene practices. All new staff and contractors should read the Operational Procedures and be aware of hygiene practices before commencing work. Assume all irrigation water is treated recycled water unless you have flushed the system or your supervisor tells you that the system has been flushed. All groups who use the irrigation area should be advised that all cuts and grazes obtained on the grounds must immediately be treated with disinfectant and covered with a dressing.Staff should be informed verbally and in writing of the potential health hazardsassociated with the use of recycled water and the safety precautions to befollowed. A commonsense approach should be used when working in areasthat utilise recycled water.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 28 of 66
  • 62. At a minimum, employee training should cover: the principles of risk management knowledge and awareness of the Recycled Water Quality Management Plan (RWQMP), including roles, responsibilities and liabilities the recycled water system, including its operation and the control measures that are in place to ensure public health protection the organisation’s protocols and policies for the system, such as system management and maintenance, sampling and analysis of water, consumer complaints, or incident and emergency plans statutory requirements relating to the recycled water system the roles and responsibilities of individuals and agencies that relate to the recycled water system, both internal and external to the organisation the documentation, reporting and auditing of the system.5.10 Storage FacilitiesStorage of recycled water is required due to seasonal and daily supplydemands to prevent runoff and hydraulic overloading during periods whenirrigation is not appropriate, such as extended periods of rain and fortemporary detention in the event of system malfunction.The recycled water being discharged to storage facilities should already betreated to a Class such that it is suitable for the intended use.Either emergency storage facilities should be provided for overflows andinadequately treated recycled water (or the RWQMP must demonstrate thatpublic health can be protected in another manner, such as the capacity toexclude the public from irrigated areas) until it can be demonstrated that thewater meets the required water quality.The size of the operational storage depends on the variations in supply anddemand and on the availability of supplementary sources of supply.Facilities for recycled water storage and disposal by land irrigation should bedesigned and constructed to contain all wastes in at least the 90th percentilewet year. In practice, this means that in order for a treatment plant to berecognised as not discharging to surface waters, that plant needs to have amanagement framework enabling the handling of all effluent in a 90thpercentile wet year. For a ‘normal’ reuse site, this is likely to involve storagefacilities, and/or reserve land, to cater for the excess of recycled water causedby reduced demand during particularly wet periods.Recycled water supply reservoirs which are closed to the public, shall beenclosed within a fenced area or other enclosure to restrict public access. Allrecycled water storage facilities shall be identified by signs on the surroundingfence or facility containing a pictorial sign in accordance with AS1319 and thewords: “WARNING: RECYCLED WATER – DO NOT DRINK OR SWIM”Storage tanks that are used to store recycled water should be structurallysound. Certification form a practicing licensed structural engineer may beGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 29 of 66
  • 63. required to verify that they are appropriate for their intended use. Anappropriately designed cover needs to be provided to these tanks.5.11 AlgaeStorage of recycled water in open storages at any stage of the treatment ordistribution has the potential to promote the growth of algae. These may beharmless green algae or the potentially toxic blue green algae(cyanobacteria). Algae in recycled water can significantly reduce its quality formany applications. Some species of blue green algae have the potential toproduce toxins which can pose a risk to human and stock health. An onsiteworker who comes into direct contact with recycled water containing highnumbers of blue green algae may be at risk of developing skin and eyeirritation or gastric inflammation. If blue-green algae are applied to pasturethe health of grazing livestock may be affected unless an appropriatewithholding period is implemented and stock are grazed on dry land.Livestock may also be adversely affected if they drink the contaminated waterand/or eat mats of dried algae left on shorelines.The risk of algal blooms is increased when nutrients (in particular phosphorus)are present at high enough concentrations and when water temperature iselevated. If there is a risk of algal blooms in stored recycled water, thetreatment system should be adjusted so that phosphorus concentrations arereduced to appropriate levels or aquatic plants should be established withinstorages so that excess nutrients can be taken up. Destratification of waterstorages may reduce the tendency for algal blooms, especially some toxicforms of blue green algae. Air flotation treatment of recycled water in pondshas proven to be highly effective at both phosphorus and algae reduction.For schemes subject to regular algal blooms, a blue green algal emergencyresponse plan should be developed. The emergency response plan shoulddetail:- allowance for alternative supply systems;- measures to allow the screening or filtering of recycled water before supply or application;- suitable mechanisms to clean and flush the distribution system;- a blue-green algal monitoring program; and- threshold blue-green algal cell numbers that trigger actions, such as cessation of supply for stock drinking.5.12 Mosquito ManagementIn Western Australia mosquitoes can be serious pests as well as potentialvectors of disease-causing viruses and parasites. Ross River virus diseaseand Barmah Forest virus disease occur state wide in environmentally-drivencycles and the rare, but the potentially fatal Murray Valley encephalitis occursin the northern half of the State.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 30 of 66
  • 64. Mosquitoes breed in fresh, brackish, salt and polluted water in natural andartificial situations, as well as artificial containers. Examples of recycled waterreuse infrastructure that may support mosquitoes include water and effluentstorage tanks, evapotranspiration beds, drains, leaking or pooling irrigationsystems, and compensation basins.It is essential that the implementation of water recycling does not enhancemosquito breeding and the transmission of disease. Some key preventativemeasures that relate to the design and maintenance of infrastructure arediscussed below.  Constructed wetlands, water impoundments, grass swales, open earth drains and other infrastructure must be designed to minimise mosquito breeding. Additionally, water level fluctuations, flow rates, and evaporation and infiltration rates must be managed in a manner that does not promote breeding of mosquitoes. Recommendations for design parameters can be found in the references listed at the end of this section.  Regular maintenance of all structures associated with storage or treatment of recycled water is necessary to minimise mosquito breeding. For example, the growth of invasive vegetation into the margins of water storage facilities will provide ideal habitat for mosquito larvae and will prevent predators from effectively reducing their numbers. Therefore infrastructure should be designed to minimise vegetation growth in shallow water and maintenance programs should include provision for the removal of invasive vegetation, aquatic emergent vegetation or mats of algae if they develop.  Funding for an ongoing maintenance program (vegetation harvesting, mosquito larviciding etc) must be part of the original project approval request for any recycled water reuse infrastructure.  Irrigation systems that will utilise recycled water should be designed to prevent surface ponding by appropriate irrigation scheduling and by ensuring that there is no leakage at pipe junctions.  Holding tanks for recycled water, rainwater or stormwater should be designed and maintained so as to permanently prevent the entry of mosquitoes. Larvicides are available that are suitable for water storage requirements, including potable water, however this approach requires ongoing, regular and costly application.  Open recycled water storages should be monitored regularly to identify the presence of mosquito larvae to allow physical or chemical control procedures to be undertaken.  Biological control using locally sourced native fish species known to prey upon mosquito larvae may be considered for some permanent water situations, but regular larval monitoring will also be required to assess the effectiveness of the fish. The use of non-native fish species (e.g. Gambusia sp.) is not appropriate because they will compete for resources or predate on native species if they escape into natural waterways.  Chemical control of larvae should only be considered as part of an appropriate integrated pest management program using only chemicalsGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 31 of 66
  • 65. registered for mosquito control. If chemicals are used, this must not contaminate the recycled water so that it is no longer fit for its intended purpose.Information on the design and management of recycled water reuseinfrastructure to minimise mosquito breeding may be obtained from theMosquito-Borne Disease Control Branch at the Department of Health (Phone08 9385 6001) or from the following publications: Department of Health Western Australia (2004) Mosquito Management Manual. Copies available from the Mosquito-Borne Disease Control Branch on Ph: 08 9385 6001. Mosquito Control Association of Australia (2002) Australian Mosquito Control Manual. Copies available from www.mcaa.org.auGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 32 of 66
  • 66. 6 Recycled Water Quality Management PlansIt is essential that recycled water schemes operate reliably and consistently toprovide recycled water of the specified quality and quantity. A RecycledWater Quality Management Plan (RWQMP) must be completed by thesupplier of all schemes.Each user of the recycled water must also complete a RWQMP; however, thedetail of this plan will depend on the scope of the final use. The RWQMPshould ensure that the treatment plant will produce water that meets therequired microbial criteria, and that the water quality is not compriseddownstream of the treatment process.In most cases, the supplier should lead the process for development of theuser’s plan as the supplier will generally have greater resources and expertisein the handling of recycled water and in risk assessment. But by the sametoken, recycled water users must take responsibility for their own safe use ofrecycled water so it is important that each user maintains ownership andcontrol over those parts of the plan that have a critical role in their use ofrecycled water.The RWQMP should include every stage in the production and use ofrecycled water. This will include: source control treatment disinfection transport storage use (including both onsite and off site impacts).For Class B, C and D schemes the RWQMP should consist of: i. The treatment process’s capability to meet the microbial criteria ii. An operations and maintenance manual containing the supporting programs required for the treatment process and management program to be effective, such as standard operating procedures, equipment maintenance and calibration programs.For Class A and A+ schemes the RWQMP should consist of: iii. The treatment process’s capability to meet the microbial criteria iv. A risk management program for achieving and maintaining the microbial criteria. This program should identify significant risks to the water quality and management controls for these risks. v. An operations and maintenance manual containing the supporting programs required for the treatment process and management program to be effective, such as standard operating procedures, equipment maintenance and calibration programs.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 33 of 66
  • 67. 6.1 Operation and Maintenance ManualsRWQMP must be developed to detect any process failure, detail contingencyoperations and ensure ongoing compliance with all conditions of approval.The RWQMP must include supporting programs required for the treatmentprocess and management program to be effective, such as standardoperating procedures, equipment maintenance and calibration programs.This plan should be in the form of an operations and maintenance manual.Procedures should be developed for each process step or significant risk, i.e.for every activity that is necessary for the safe operation of the system. Thiswill include routine maintenance, corrective actions and emergency response.Each procedure should contain the following information:- The purpose of the procedure.- Who is responsible for maintaining the procedure (i.e. who is responsible for updating the procedure and ensuring its ongoing relevance, including managers who are responsible for the regular review of procedures).- What tasks must be performed under the procedure, when and by whom: this will include relevant operational employees and supervisors.- Which parameters must be monitored including, where relevant, critical limits for each parameter.- Record keeping requirements for each procedure.- Corrective actions in the event of a non-conformance with the procedure.Operation and Maintenance Manuals should include (but not be limited to) thefollowing information for each recycled water scheme.Operation and Maintenance of the Wastewater Treatment Plant  Operations of the plant  A contingency plan detailing corrective and preventative actions to be taken in the event of system failure.  Maintenance Procedures, Schedules and Records.  Operating recordsOperation and Maintenance of the Recycled Water Scheme.  Map of pipeline route from WWTP to irrigation sites including location of chlorinators, surge tanks, storage dams, pump stations, sample points etc.  Description and plans of control mechanisms including signage, fencing, access, mosquito management, etc  Plan of all sites and their irrigation method and design layout.  Delegated areas of responsibility for all staff involved with the scheme.  Maintenance Procedures (see section 6.1.2), Schedules and Records.  Surveillance of operation.  Irrigation schedule and methods for control spray drift and runoff.  A contingency plan detailing corrective and preventative actions to be taken in the event of system failure (see section 6.1.1).Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 34 of 66
  • 68.  Induction/handover procedures for operators and new staff.  Health and safety issues when dealing with recycled water (see section 5.8).  Contact names and telephone numbers of all people involved in the scheme. Including the Department of Health contact details. Wastewater Management Branch Department of Health PO Box 8172 Perth Business Centre WA 6849 Telephone No: (08) 9388 4999 Fax: (08) 9388 4910Operation and Maintenance of the Disinfection Unit.  Clear procedure of maintenance and operation of the disinfection unit.  A log book is to be kept to detail all actions and inspections that have been carried out.  Safety and health section. It must be remembered that proper training must be given to anyone handling chlorine or other chemicals.  Contact details of those people responsible for maintaining disinfection unit.Program for Monitoring the Recycled Water Scheme.  Monitoring Procedures, Schedules and Records.  Sampling Protocol. Where and when to collect samples. Include the DOH pamphlet “Recycled Water Sampling Technique.”  Where and how to send samples to the National Association of Testing Australia (NATA) accredited laboratory to be analysed.  What to do if results are elevated.  Copy of a correctly completed NATA accredited laboratory “Sample Request Form”. The form should state that the operator be notified when results are above the approved standard.  Operational records of monitoring.6.1.1 Contingency PlansContingency Plans should be developed for recycled water reuse schemes forpossible occurrences of a non-compliance event. The contingency planshould include, but not limited to: Treatment Plant Failures, Disinfection System Failures, Non-compliance of Water Quality Standard, Irrigation Failures, Failure of backflow prevention devices, and Spills or Overflows.The contingency plan should also include: a list of conditions which would require an immediate diversion and/or shutdown to take place, a description of the diversion and/or shutdown procedures,Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 35 of 66
  • 69.  a description of the diversion area including capacity, holding time and return capabilities, a description of plans for the activation of supplemental supplies (if applicable), a plan for the disposal or treatment of any inadequately treated effluent, a description of fail safe features in the event of a power failure, and a plan (including methods) for notifying the recycled water user(s), the Local Government, the DOH and other agencies as appropriate, of any treatment failures that could result in the delivery of inadequate treated recycled water to the use area.6.1.2 Maintenance ProgramA preventative maintenance program must be developed to ensure equipmentis kept in reliable operating condition.Maintenance must be regularly conducted to ensure the scheme complieswith the conditions of approval and the following operational issues aremanaged: Unapproved uses: uses other than those approved by the DOH are strictly prohibited. Prevention of Cross-Connections: a cross connection is defined as an unprotected actual or potential connection between a potable water system used to supply water for drinking purposes, and the recycled water system. Equipment maintenance: all equipment shall be maintained in good working order. Broken or faulty irrigation components shall be promptly repaired. All signs, equipment identification devices, and colour coding shall be maintained. Runoff: all irrigation systems shall be designed, constructed and operated to minimise the runoff of recycled water outside of the approved area. Ponding: All irrigation systems shall be designed, constructed and operated to minimise the ponding of recycled water both inside and outside of the approved area. Windblown Spray: All irrigation system shall be designed, constructed and operated to minimise, to the fullest extent, the possibility of recycled water spray being carried outside of the approved area. No Overspray: Recycled water shall not be sprayed on people, food handling facilities, playground equipment, BBQ’s or drinking fountains.If treated recycled water is to be left in the system over winter, it is likely toexperience regrowth and lead to odour issues at the start of the next season.If the pipes cannot be flushed with bore or fresh water then the system shouldbe super-chlorinated.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 36 of 66
  • 70. 6.2 Risk Management Program for Class A and A+ SchemesA risk assessment must be completed for all projects where production anduse of recycled water may involve risks to human health. The risks involvedwith using recycled water will be dependant on the source of water, thetreatment process, the use to which it is applied, the site of application and themanagement system used.The risk management approach contained in these guidelines is based on thedraft National Guidelines for Water Recycling (NRMMC and EPHC) and theHACCP (Hazard Analysis Critical Control Point) system (CAC 1997).Risk assessment is best guided using a preventative risk managementframework such as HACCP. A HACCP Plan is a well recognised procedure ofanalysing a process to identify the critical points in that process which willaffect the output.The key elements of HACCP should be integrated into the plan to ensure thatall recognisable risks to human health from the proposed recycled water usehave been identified, monitored and controlled.The steps in risk assessment involve consideration of the consequence of allhazards (i.e. their severity), their likelihood (or probability) and the exposure ofthe target organism, population or ecosystem to the hazard (eg how manypeople are likely to be affected). This allows the overall risk (i.e.consequence, likelihood and exposure) to be estimated. a hazard is a biological, chemical, physical or radiological agent that has the potential to cause harm. A hazardous event is an incident or situation that can lead to the presence of a hazard (what can happen and how). A risk is the likelihood of identified hazards causing harm in exposed populations in a specified timeframe, including the severity of the consequences.There are 12 steps in HACCP, including 5 preliminary steps and 7 principles.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 37 of 66
  • 71. Figure 1: The HACCP Process6.2.1 The twelve steps of HACCPStep 1 - Assemble HACCP TeamThe HACCP Team should be a multidisciplinary team knowledgeable of theprocess and product, with a broad range of expertise and skill in all aspects ofthe recycled water system. The team plans, develops, verifies and implementsthe HACCP plan.Step 2 - Describe ProductA full description of the recycled water is documented. This description mayinclude: water source; treatment processes; storage and distribution; and anyspecial considerations to maintain recycled water safety.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 38 of 66
  • 72. Step 3 - Identify Intended UseThe expected use of the recycled water is documented including: how therecycled water is to be used; consumer instructions for recycled water use;and who the recycled water is intended for.Step 4 - Construct Flow DiagramFlow diagram must clearly indicate all process steps in the operation. The flowchart must state when the company’s responsibility starts (bulk treated water,raw source water) and ends (at the meter box, at consumer tap). Steps priorto and after the organisation’s direct responsibility should also be included.Step 5 - Confirmation of Flow DiagramThe HACCP team confirms that the flow diagram is both complete andaccurate as it is used in the hazard analysis. The best validation is to walkthrough and verify the set up of the system and processes. If this is notpossible, those with operational knowledge of the system can validate the flowdiagram.Step 6 - Conduct a Hazard Analysis [Principle 1]A significant hazard is one that must be prevented, eliminated or reduced toan acceptable level to produce safe recycled water. Hazards may bebiological, chemical or physical. Generally the hazards of greatest concern forthe recycled water plant are those that are biological (pathogens). However, itmay be appropriate to consider chemical and physical hazards, such as thosethat may result in chemical contamination of the recycled water or physicaldamage to the recycled water plant or reuse area.The hazard analysis consists of three steps, which should be documented: Identify hazardous events at each step in the process that may impact on water quality. Determine the risk and significance of each hazardous event. This is the product of how frequently the hazardous event is expected to occur and what the consequences of that event occurring are. Identify control measures for each hazardous event. These include system input management, physical barriers (such as treatment steps), monitoring, standard operating procedures and personnel training. More than one control measure may be required to control a particular hazard, and more than one hazard may be controlled by a particular measure.Step 7 - Determine Critical Control Points (CCPs) [Principle 2]A CCP is a point, step or procedure at which control can be applied and ahazard can be prevented, eliminated, or reduced to acceptable levels. Thedecision tree in Figure 2 may be used to determine if a process step is a CCP.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 39 of 66
  • 73. Figure 2: Decision tree to identify CCPsStep 8 - Establish Critical Limits [Principle 3]Critical limits are assigned to each control measure at a CCP. All CCP’s musthave limits for their operational parameters that are defined and validated. Acritical limit distinguishes between acceptable and unacceptable performance.When a critical limit is not met, corrective actions should be immediatelyinstituted to resume control of the process.Step 9 - Monitoring [Principle 4]Monitoring is planned observations or measurements to provide a record. Allcritical limits have associated monitoring activity to ensure that the critical limitis met. A monitoring regime that identifies the location and frequency ofGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 40 of 66
  • 74. monitoring, and a description of the method or procedure of monitoring mustbe established. If monitoring indicates that the critical limit has not been met,then corrective action must be taken.Step 10 - Establish Corrective Actions [Principle 5]Corrective actions are taken when a critical limit is not met. If a critical limit isindicative of the treatment process providing sufficient pathogen removal, thenthe corrective action for not meeting that limit might be to stop water deliveryto end users. Corrective actions ensure that the CCP is brought undercontrol. Corrective actions can include: immediate action, responsibility forcorrective action, disposition of recycled water and the root cause of theproblem. The documentation of corrective actions must include whatimmediate action is required to resolve the problem, who is responsible forundertaking the corrective action, and who must be notified.Step 11 - Establish Verification Procedures [Principle 6]Verification procedures are used to determine whether the control measuresare effective and whether the water quality management plan is beingimplemented appropriately.Verification includes: testing the monitoring and procedures identified in the HACCP plan during commissioning of the treatment process. Validation of critical limits Equipment calibration Cleaning and maintenance programs HACCP plan reviews and internal/external audits Ongoing evaluation of monitoring data to assess the overall performance of the treatment process and HACCP plan.Step 12 - Establish Documentation and Record Keeping [Principle 7]Documentation is required as proof of compliance to the HACCP plan and toprovide a legal defence for due diligence. HACCP records should be datedand signed. Records should provide recycled water traceability. Appropriatedocumentation provides the foundation for establishing and maintaining aneffective HACCP plan. Documentation should include:  information used to develop the HACCP plan  CCPs, critical limits, monitoring and corrective actions  standard operating procedures relied upon or specifically developed for the HACCP plan  verification activities, including the validation of critical limits  records generated as a result of monitoring  reviews and modifications to the HACCP plan.6.2.2 ValidationThe validation of critical limits is essential for substantiating that the systemcan be controlled to meet the water quality objectives, and the associatedmonitoring activities will be able to effectively indicate this. Validation mustoccur before supply of recycled water can commence.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 41 of 66
  • 75. The first stage of validation is to consider data that already exists. This caninclude data from the scientific literature, existing guidance, historical data (forexample from other schemes) and supplier knowledge.The second stage of validation is to determine whether additional testing isrequired – for example, whether specific on-site studies are necessary – andto collect and analyse the appropriate data. As validation is not used for theday-to-day management of the system, parameters that may be inappropriatefor operational monitoring can be used. These may include microorganisms ortracer studies.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 42 of 66
  • 76. 7. Monitoring and ReportingThe aim of a monitoring program is to demonstrate that the recycled water isachieving the required level of treatment for its intended use. The level ofmonitoring required will depend on the reliability of the treatment process, themethod of irrigation and the risk to public health.Monitoring within a recycled water scheme has three core components, theseare: 1. Validation monitoring: (Will it work?) Is monitoring that proves that the system delivers the expected water quality. It takes place during the commissioning phase before the scheme goes live, and again after changes are made. Monitoring is focused on microbiological indicators.Table 5: Examples of Validation monitoring for health risks Associated monitoring: items that will subsequently Process step to Validation monitoring be routinely monitored be validated during operational monitoring Sewer catchment On-site inspection of the trade waste • Trade waste licence trade waste and sewer protection controls at agreements controls major hazard facilities and examination of their technical validity Primary settling Inlet and outlet microbial indicator • Flow rate through the system system concentrations:a • Solids depth • Monitoring should at the very least include E. coli, would ideally include coliphage and clostridial spores, and may include some pathogens. Secondary Inlet and outlet microbial indicator • Flow rate through the system treatment concentrations:a • Sludge blanket depth system • Monitoring should at the very least include E. coli, would ideally include coliphage and clostridial spores, and may include some pathogens. Lagoon Inlet and outlet microbial indicator • Flow rate through the system concentrations:a • Toxic blue-green algal levels • Monitoring should at the very least and toxin concentrations include E. coli, would ideally include • Microbial indicator coliphage and clostridial spores, and concentrations may include some pathogens. Media filtration Inlet and outlet microbial indicator • Turbidity upstream and b a plant concentrations: downstream of system • Monitoring should at the very least • Head loss across system include E. coli, would ideally include • Particle counts on outlet coliphage and clostridial spores, and • pH and temperature may include some pathogens. • Coagulant dosage rate • Streaming current Membrane plant Inlet and outlet microbial indicator • Turbidity upstream and a concentrations: downstream of system • Monitoring should at the very least • Head loss across system include E. coli, would ideally include • Particle counts on outlet coliphage and clostridial spores, andGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 43 of 66
  • 77. may include some pathogens. Ultraviolet plant Inlet and outlet microbial indicator • Turbidity upstream of a concentrations: disinfection system • Monitoring should at the very least • UV transmissivity include E. coli, would ideally include • UV intensity and/or calculated coliphage and clostridial spores, and dose may include some pathogens. • Flow rate to enable calculation of retention times • Ballast functionality, lamp power and lamp status Chlorination Inlet and outlet microbial indicator • Turbidity upstream of b a plant concentrations: disinfection system • Monitoring should at the very least • Free chlorine, temperature include E. coli, would ideally include and pH at downstream coliphage and clostridial spores, and monitoring point, certainly well may include some pathogens. after the point at which the immediate chlorine demand has been satisfied, and ideally at a point representing a significant proportion of the total required contact time • Flow rate to enable calculation of Ct Cross-connection Check every drinking-water property • Flow rate measured through control connection by turning off the drinking- meters water supply at each property in series, leaving the recycled supply turned on (charged with drinking water); then check all drinking and recycled water outlets to confirm that only the recycled water outlets on the property are live and that no drinking- water outlets are live. Accidental Confirm that minimum heights, • Inspection of labels and ingestion labelling, colouring, threads and fittings control fittings are in use by inspecting all connected properties and their outlets. User agreements Confirm that all users have been • Oversight of usage practices bound by their user agreements by direct telephone interview or through written reply and signature.Ct = contact timea: If inlet microbial indicator concentrations are too low to enable validation of the required log reduction,seeding of challenge microorganisms is required.b: For conventionally filtered or membrane filtered effluent with a turbidity that does not exceed 2 NTU(nephelometric turbidity units), or lagoon treated water with a turbidity that does not exceed 5 NTU,partly theoretical validation based on the objective measurement of Ct and what is known aboutmicrobial inactivation is acceptable and microbial indicator validation is not essential; some suchmonitoring will be undertaken as part of verification monitoring.Source: National Guidelines for Water Recycling (NRMMC and EPHC in draft)Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 44 of 66
  • 78. 2. Operational Monitoring: (Is it working now?) Is the routine monitoring conducted to ensure the system is operating as intended. Monitoring involves a broad range of parameters with both observation (eg warning signs in place), electrochemical devices (eg pH, turbidity and chlorine), and microbiological indicators.Table 6: Examples of Operational Monitoring and supporting programsfor health risks. Process step to Operational monitoring Supporting programs be monitored Media filtration • Turbidity downstream of system • Instrument calibration plant • Head loss across system • Asset maintenance program • pH and temperature Primary settling • Flow rate through the system • Instrument calibration system • Solids depth • Asset maintenance program Secondary • Flow rate through the system • Instrument calibration treatment system • Sludge blanket depth • Asset maintenance program Lagoon • Flow rate through the system • Instrument calibration • Toxic blue-green algal levels and • Asset maintenance program toxin concentrations • Microbial indicator concentrations Membrane plant • Turbidity downstream of system • Instrument calibration • Head loss across system • Asset maintenance program • Particle counts on outlet Ultra violet (UV) • Turbidity upstream • Instrument calibration plant • UV transmissivity • Asset maintenance program • UV intensity and/or calculated dose • Flow rate • Ballast functionality • Lamp power • Lamp status • Cleaning frequency Chlorination plant • Turbidity upstream • Instrument calibration • Free chlorine, temperature and pH • Asset maintenance program at downstream monitoring point • Flow rate to enable calculation of Ct Over-irrigation • Soil moisture content • Instrument calibration control • Irrigation time • Asset maintenance program Accidental • Timing of irrigation • Instrument calibration ingestion control • Direction of sprinkler throw prior to • Asset maintenance program application • Wind direction prior to application • Presence, currency and comprehension of user agreements • Presence, integrity and clarity of fittings, signage and other end user controlsSource: National Guidelines for Water Recycling (NRMMC and EPHC in draft)Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 45 of 66
  • 79. 3. Verification Monitoring: (Did it work?) Is the monitoring conducted to ensure compliance with the RWQMP.Table 7: Examples of Verification monitoring Process steps Verification monitoring At recycled water • Check that calibration schedules comply with requirements for treatment plants monitoring equipment used for operational monitoring. • Check that preventative maintenance schedules are being adhered to for equipment that controls recycled water quality. • Check that log books or recording systems are being completed to report the results of operational monitoring and details of the corrective actions taken in response to any deviations detected. At the point of Monitoring of the microbial indicator concentrations should at the very supply least include E. coli weekly, would ideally include coliphage and immediately clostridial spores weekly for higher grade systems (eg for a typical dual downstream reticulation system median E. coli < 1 per 100 mL, somatic phage < 10 of the completion pfu/100 mL, Clostridium perfringens < 1 per 1 L), and may include some of final pathogens monthly or quarterly for the highest grade systems. disinfection, but upstream of any open lagoons or basins At the point of Check that log books or recording systems are being completed to use report the results of operational monitoring and details of the corrective actions taken in response to any deviations detected.Source: National Guidelines for Water Recycling (NRMMC and EPHC in draft)7.1 Monitoring ProgramThe development of a monitoring program that meets the provisions listed inTable 9 is an essential element of a sustainable recycled water scheme. Inaddition, for irrigation schemes, a program should be developed to monitor thepotential impacts on the receiving environment. It must be documented in theRWQMP and describe the organisation that has responsibility for undertakingthe monitoring. Usually it is the recycled water supplier that will undertake themonitoring for water quality.Factors such as the quantity and quality of recycled water and the risksassociated with use should be considered when developing the receivingenvironment monitoring program. For example, the monitoring requirementsfor a 10 kilolitres per day reuse scheme will generally be significantly less thanthose for a 10 megalitres per day scheme.A recycled water monitoring program should: i. Specify flow-monitoring provisions. The volume of recycled water flowing to the reuse scheme should be monitored and recorded; ii. Specify the parameters to be monitored. Monitoring of the water quality parameters listed in Table 9 should be undertaken. In addition, monitoring practices for potential contaminants and toxicants (heavy metals, organics and inorganics) in irrigation water containing trade and other industrial wastes may be required. Monitoring for these additional parameters will depend on the source/s of recycled water (for example,Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 46 of 66
  • 80. domestic, industrial or animal waste sources), the concentrations of contaminant/s present, and the reuse schemes; iii. Define appropriate sampling locations. The point at which the quality of the recycled water is to be demonstrated should be described; and iv. Specify sampling frequencies. Default sampling frequencies are specified in Table 9.Records of monitoring results should be kept in order to demonstrate ongoingcompliance with conditions of approval. Records to be kept include: i. exceedences of quality limits and corrective action taken, ii. details of incidents and corrective action taken, iii. inspection and maintenance reports, and iv. monitoring data.Reuse Area MonitoringThe monitoring program developed should be able to identify changes thatmay occur at or around the application site as a result of recycled waterirrigation. It should provide the operator with an early warning of any risk topublic health. Regular monitoring of the irrigation area should ensure noponding or runoff is occurring, signage is in place and not damaged and theirrigation systems is working properly. Soil quality should be monitored toensure that no harm is being done to soil structure and chemistry.The recycled water piping system should be inspected and the operationtested at all new services at installation, all services on change of ownership,all services following completion of property extension or plumbingmodification and at least every 5 years.Groundwater monitoringIn areas where the soils are porous and/or the groundwater is close to thesurface, it may be necessary to conduct groundwater monitoring either underor down-gradient of the irrigation area to ensure that the quality of thegroundwater is not compromised for any other beneficial uses. Of particularconcern would be nitrate or bacteriological contamination of groundwater thatmight be used for drinking. A risk assessment should be carried out todetermine the need for such monitoring and if it is required, where sampling isneeded, how often, and what the water should be tested for.7.1.1 Bacteriological MonitoringThe DOH requires that all recycled water use is subject to samples of therecycled water being submitted for bacteriological examination on a regularbasis and it is notified if there is a failure or the system operation and thewater quality requirements. Sampling points should be located immediatelyafter disinfection.Monitoring regimes in Table 9 are the minimum recommended where theremay be a risk to public health. All users must conduct initial and periodicGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 47 of 66
  • 81. monitoring to establish effluent quality and the reliability of the treatmentprocess. Demonstration that treatment processes are satisfactory and thatquality assurance processes are operating is an acceptable alternative toregular ongoing monitoring in some instances.All sampling protocols used and monitoring programs undertaken during theproduction and use of recycled water should take place in accordance witheither of the following publications Water Quality Monitoring and Reporting(ANZECC and ARMCANZ 2000) or the DOH “Standard Recycled WaterSampling Technique”. The recycled water samples are to be analysed by aNational Association of Testing Authority (NATA) registered laboratory.If microbiological samples exceed the required limit contact the DOHimmediately. Investigate the cause of the exceedences and resample assoon as possible. It may be required to shut down the system or ensure thatthere is no public access to the area irrigated until the problem can berectified. The system should not be reconnected until the recommendedwater quality has been met.Suppliers should periodically undertake investigations for the presence oftoxicants such as heavy metals and organic chemicals in recycled water.Such toxicant investigations should occur when a modification to a treatmentplant process commences operation, or when significant changes occur withinthe sewerage catchment (such as a new or modified trade and/or industrialwaste connections).7.1.2 Monitoring of Class A recycled waterAlthough demonstration of recycled water quality prior to supply is importantfor all classes, a formal pre-commissioning phase is critical for Class Arecycled water. The verification of the water quality as Class A must besupported by a period of microbial monitoring (a pre-commissioning, or plantverification program). Monitoring should occur over a minimum of two-months. The pre-commissioning phase must be described in the RWQMP.For Class A schemes, continuous monitoring to demonstrate treatmentreliability must be undertaken. This includes online monitoring of turbidity anddisinfection efficiency (such as chlorine residual). Weekly monitoring of otherindicators and daily inspections of the disinfection unit are also suggestedbest practice. The need for an ongoing monitoring program to confirm removalof pathogenic organisms will also need to be assessed and described in theRWQMP.For treatment trains without a performance record, it is expected that thecommissioning phase would at least involve monitoring of raw sewage andrecycled water to detect E.coli, adenoviruses, rotaviruses, enteroviruses, reoviruses, hepatitis A, Cryptosporidium and Giardia. For treatment trains thathave a demonstrated track record of achieving a Class A quality water, areduced pre-commissioning phase may be appropriate.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 48 of 66
  • 82. Below is an example of monitoring that may be required for the followingexample wastewater treatment plant.“Example” Class A Wastewater Treatment Plant Influent (raw sewage) A Activated sludge Class A treatment process Chlorination/ B Screens C Ultrafiltration D Storage E Discharge“Example” Water Quality Sampling Program Organism Location Volume Frequency DurationE.coli A, B, D, E 100 mL Weekly 8 weeksFRNA phage A, B, D, E 100 mL Weekly 8 weeksAdenovirus* A, B, D, E** 50 L Fortnightly 8 weeksEnterovirus* A, B, D, E** 50 L Fortnightly 8 weeksReovirus* A, B, D, E** 50 L Fortnightly 8 weeksCryptosporidium A, B, D 50 L Fortnightly 8 weeksGiardia A, B, D 50 L Fortnightly 8 weeksHelminths A, B, D 1L Four-weekly 8 weeks* Adenovirus, enterovirus and reovirus can be sampled together from the one 50L volume.** Given it is anticipated that all enteric viruses will be removed by the ultrafiltration step, sampling at point E isoptional. It should be noted, however, that if samples at point D are positive for these organisms, then sampling at Ewill be required.Notes Sampling from the influent to the existing secondary treatment process (i.e. raw sewage) is also required – this will indicate the log reductions of organisms that are achieved by treatment at this step and the reasonable worst-case scenario for pathogens hitting the Class A plant if the WWTP fails to perform. The final water quality must meet the following: o <1 E.coli/100mL o <1 Enteric virus/50L o <1 protozoa/50L o <1 helminth/L7.1.2.1 Cessation of SupplySchemes that require Class A recycled water must have automatic shut downmechanisms in place. This ensures that there is no supply at times of non-compliance with specific treatment and water quality. The triggers forcessation of supply will depend on the treatment train used and will need to bespecified in the RWQMP, after endorsement by DOH. Indicative triggers are:  greater than 40 E.coli per 100 millilitres;  any plant failure;Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 49 of 66
  • 83.  any failure of the disinfection unit;  a turbidity reading that exceeds the maximum of five NTU;  an average 24 hour turbidity reading that exceeds two NTU;  a reduction in disinfection efficiency or reduction in chlorine residual below one milligram per litre.7.1.3 Notification LimitsCessation of supply and any other non-compliant results for Class A recycledwater must be immediately reported to the DOH. Supply will only be resumedafter the DOH has granted approval.Table 8 lists the microbiological notification limit for all schemes other thanClass A. These limits apply at the end of the treatment process (that is, priorto discharge to storage facilities).If the notification limits are exceeded, immediate re-sampling should beundertaken. If they are exceeded on two consecutive occasions, supplyshould cease, an investigation undertaken and corrective action taken. Theuser and the DOH need to be notified immediately. Supply may resume whenthe problem has been rectified. The action/s taken to rectify the problemshould be documented.Table 8. Microbiological notification limits for recycled water classesother than Class A Microbiological Notification Class limits (E. coli per 100mL) limits B <100 400 C <1,000 4,000 D <10,000 40,0007.2 ReportingRecords of all monitoring results and analyses should be kept for at least tenyears in order to analyse trends and demonstrate ongoing compliance withthe objectives of these Guidelines.Records should include:  an analysis of trends in the parameters monitored;  the exceeding of quality limits and corrective action taken;  details of incidents and corrective action taken;  inspection and maintenance reports;  monitoring data; and  record of flow data.Suggested measures for reporting by suppliers should include:Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 50 of 66
  • 84.  A listing or register of supplied reuse schemes, including quality, quantity and type of reuse supplied to.  Regular inspections and maintenance of treatment, reticulation and reuse facilities.These records should be made available to the DOH and users upon request.Suppliers of recycled water must submit a summary report on the aboveinformation to the DOH annually.7.2.1 Emergency reportingIn the event of an emergency incident, the user and/or supplier must notify theDOH, any other relevant regulatory body and affected parties as soon aspracticable. Notification should be prompt and include details of corrective andfuture preventative action being taken.7.3 AuditingAuditing is important to ensure that suppliers and those who reuse meet theirobligations under these Guidelines. Auditing ensures:  that the supplier and user/s are meeting their obligations under these Guidelines and any other relevant legislation, policies, standards and guidelines;  whether the RWQMP is being implemented resulting in compliance with the Guidelines; and  any inadequately managed risk exposures (environmental, human and stock health) and possible adverse publicity associated with the reuse scheme are identified.The process for undertaking audits and the people or organisations involvedin the process should be described in the RWQMP. This guideline does notinclude formal requirements for a DOH appointed auditor to undertakescheme audits. Although large schemes should consider a third party auditprocess.Audits undertaken in accordance with other QA systems such as the HACCPwill satisfy the provisions under these Guidelines, provided the system fullyaddresses the use of recycled water.Audit frequency will depend upon the size of the scheme and the level of riskposed but should occur every two years for schemes that use more than 1ML/d. It is suggested that smaller reuse schemes be audited at least everythree years. As discussed, the DOH will conduct selected audits of reuseschemes to ensure compliance with these Guidelines. Audits will also identifythe effectiveness of such guidelines in the minimisation of risks associatedwith reuse schemes.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 51 of 66
  • 85. Table 9: Recycled Water Uses, Required Class, Recommended Monitoring and Site Management Controls. Recycled Water Quality Type of Reuse Class Site Management Controls Monitoring*URBAN (non potable) Indicative monitoring**Residential - pH, BOD, SS, E.coli weekly - Appropriate signage in accordance with AS 1319 – Safety Signs- garden watering - turbidity and chlorine residual - Monitoring and Audit Programs- toilet flushing A continuous - RWQMP- third pipe systems - disinfection system daily1Municipal with uncontrolled Indicative monitoring**access - pH, BOD, SS, E.coli weekly - Appropriate signage in accordance with AS 1319 – Safety Signs.- irrigation of ovals, parks, - turbidity and chlorine residual - Monitoring and Audit Programs. Amedian strips, golf courses continuous - RWQMP.etc - disinfection system daily1 - Restrict public access during irrigation period and for a period of 4Municipal with controlled hours after irrigation or until dry3.public access 2 - pH, BOD, SS , E.coli monthly - If offsite discharge is likely recycled water of Class A or B quality- irrigation of ovals, parks, - disinfection system daily1 may be required. median strips, golf courses C - Appropriate signage in accordance with AS 1319 – Safety Signs. etc - Monitoring and Audit Programs.- ornamental ponds - RWQMP Indicative monitoring** - pH, BOD, SS, E.coli weekly - disinfection system daily - Appropriate signage in accordance with AS 1319 – Safety Signs - turbidity and chlorine residualFire fighting A+ - Monitoring and Audit Programs continuous - RWQMP - initial suite of chemical analysis from DOH Chemical GuidelinesAGRICULTURALFood crops Class A uses Indicative monitoring** - Appropriate signage in accordance with AS 1319 – Safety SignsGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 52 of 66
  • 86. (table 4) A - pH, BOD, SS, E.coli weekly - Monitoring and Audit Programs- consumed raw or sold to - turbidity and chlorine residual - RWQMPconsumers uncooked or continuousunprocessed grown less than - disinfection system daily11 metre above ground, withdirect contact with recycledwater. - RWQMP - Restrict public access during irrigation period and for a period of 4 hours after irrigation or until dry.Food crops Class C uses - Specific agriculture controls as per section 3.2 and Table 4 eg(table 3) withholding periods.- sold to consumers cooked or - pH, BOD, SS2 monthly - Dropped produce that is potentially consumed raw is not to beprocessed, grown over 1 - E.coli weekly C harvested.metre above the ground, not - Crops required to be cooked or processed must be cookedin direct contact with recycled (>70° for at least 2 minutes) or commercially proc essed before Cwater. sale for domestic use. - Appropriate signage in accordance with AS 1319 – Safety Signs. - Monitoring and auditing programs. - Restrict public access or harvesting during irrigation period and Non food crops - pH, BOD, SS2 monthly for a period of 4 hours after irrigation or until dry3.- turf, woodlots, forestry, D - E.coli weekly - Appropriate signage in accordance with AS 1319 – Safety Signs.flowers etc - Monitoring and auditing programs. - Restrict public and stock access during irrigation period and for a- Irrigating Pasture or Fodder period of 4 hours after irrigation or until dry3, drying or ensiling offor dairy animals fodder must be undertaken.- Livestock drinking water - pH, BOD, SS2, E.coli weekly - Appropriate signage in accordance with AS 1319 – Safety Signs.(except pigs) B - disinfection system daily1 - Monitoring and auditing programs.- Washdown water for dairy - RWQMP.sheds and stockyards (but not - Specific agriculture controls as per section 3.2 and Table 4 egmilking equipment) withholding periods.Irrigating Pasture or Fodder C - pH, BOD, SS2 monthly - Restrict public and stock during irrigation period and for a periodGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 53 of 66
  • 87. for grazing animals (except - E.coli weekly of 4 hours after irrigation or until dry3, drying or ensiling of fodder.pigs) - Helminth control for cattle or dairy grazing with dairy animals also requiring a 5 day withholding period. - Specific agriculture controls as per section 3.2 and Table 3 eg withholding periods - Appropriate signage in accordance with AS 1319 – Safety Signs. - Monitoring and auditing programs. - RWQMPINDUSTRIAL - Appropriate signage in accordance with AS 1319 – Safety Signs - Monitoring and Audit Programs. - RWQMP. - Additional treatment may be required to prevent scaling,Open systems (high human - pH, E.coli weekly corrosion, biological growth, fouling and foaming.contact) - turbidity and chlorine residual A - Class A recycled water generally recommended but could be site- wash down water continuous specific eg Class B is acceptable for saleyards or stockyard- dust suppression /control - disinfection system daily1 washdown. - Controls to be implemented (eg protective clothing and equipment) to prevent exposure of workers to spray drift, aerosols, etc. - Class C recycled water is generally recommended but could beClosed systems (low site specific.human contact) C - Site and process specific - Additional treatment may be required to prevent scaling,- boiler feed corrosion, biological growth, fouling and foaming.- cooling water - RWQMPNotes to Table 61. Disinfection systems refer to chlorination, UV or other chemical/physical disinfection systems. Monitoring requirements include checking chlorine residual oroperational checking of equipment. Inspection frequency does not apply to lagoon-based systems.2. Suspended solids are not used for monitoring the performance (water quality) of lagoon systems.3. Public access restrictions do not cover on-site workers. On-site worker access should be restricted as far as it does not impede on their duties and toensure compliance with any occupational health and safety guidelines.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 54 of 66
  • 88. * A monitoring frequency reduced below that described in this table may be acceptable for small treatment plants that have demonstrated reliability ofperformance coupled with uses that do not require high quality recycled water (for example, Class C).** Monitoring described is indicative since monitoring programs for schemes requiring class A recycled water will need to be customised to reflect thetreatment train process used and the available information on the treatment train efficiency and reliability. A commissioning phase with more detailedmicrobiological testing and an ongoing program for verification of pathogen (such as virus and protozoan) removal will also be undertaken (7.1).Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 55 of 66
  • 89. 8 AppendicesAppendix A: GlossaryANZECC: Australian and New Zealand Environment and ConservationCouncilARMCANZ: Agricultural and Resource Management Council of Australia andNew ZealandAS/NZS: Australian and New Zealand StandardBOD: Biological Oxygen Demand - a measure of the oxygen demandingsubstances required for the breakdown of organic material; usually refers to afive day test of the total BOD in a sample and may then also be referenced asBOD5; expressed in milligrams per litre (mg/L).cfu: colony forming unitChlorination: the application of chlorine or chlorine compounds to water orrecycled water, usually for the purpose of pathogen reduction, but often toprovide chemical oxidation and odour control.Controlled access: Areas where public or livestock access is restricted fordefined periods of time so as to minimise the likelihood of direct physicalcontact with recycled water.Control measure: Any action or activity that can be used to prevent oreliminate a hazard or reduce it to an acceptable level.Critical control point: A point, step or procedure in a recycled waterprocess at which control can be applied, and a safety hazard can as a resultbe prevented, eliminated or reduced to acceptable levels.Critical limit: The maximum or minimum value to which a physical, biologicalor chemical parameter must be controlled at a critical control point to prevent,eliminate or reduce to an acceptable level the occurrence of the identifiedsafety hazard.Cross-connection: A physical connection between the recycled water anddrinking water supply systems.Disinfection: A process which destroys, inactivates or removes pathogenicmicro-organisms.DOH: Department of Health, Western AustraliaDrinking water: Water intended primarily for human consumption. Alsoknown as potable water.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 56 of 66
  • 90. Dual reticulation system: two separate and distinct piping systems; one ofwhich is used to transport water for potable use and the other for non-potableuse. Sometimes referred to as a ‘third pipe scheme’ or ‘dual pipe scheme’.Effluent: Treated or untreated wastewater flowing out of a wastewatertreatment plant or transfer system.E coli: Escherichia coli. A thermotolerant coliform organism, predominantlyfaecal coliforms; used as an indicator of faecal contamination. It is expressedas organisms per 100mL.Ensiling: Process for preservation of animal fodder crops by storage in silos,pits or trenches with exclusion of air.Filter: A device or structure for removing solid or colloidal material fromliquids by physically trapping the particles and removing them.Flocculation: The formation of settleable particles from destabilised colloidal-sized particles.Furrow irrigation: A method of irrigation whereby water is applied via smallditches or furrows that lead from the supply channel, thus wetting only part ofthe ground surface.Groundwater: Subsurface water from which wells, springs, or bores are fed.HACCP: Hazard Analysis and Critical Control Point. An industry recognisedrisk management system to control safety hazards in a process by applying atwo part technique: first, an analysis that identifies hazards and their severityand likelihood of occurrence; and second, identification of critical controlpoints and their monitoring criteria to establish controls that will reduce,prevent, or eliminate the identified hazards.Hazard: A biological, chemical, physical or radiological agent that has thepotential to cause harm.Hazardous event: An incident or situation that can lead to the presence of ahazard.Helminths: Parasitic worms including roundworms, tapeworms, hookwormsand pinwormsIndirect Potable: The derivation of drinking water from surface orgroundwater reclamation containing some proportion of treated recycledwater.Lagoon: A large pond or holding dam used to contain and/or treat recycledwater.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 57 of 66
  • 91. Membrane filtration: Recycled water is passed through porous membranes,with differentiation between classes of membranes typically on the basis ofthe maximum molecular weight or size of compound capable of passingthrough the membranes. Membrane techniques such as microfiltrationtypically have pores from 50 to 10,000 nm, ultrafiltration usually involves poresfrom 1 to 100 nm, while nanofiltration and reverse osmosis typically havefiltration equivalent to pores of 0.1 to 1 nm.mL: millilitre90th percentile: When expressed as a limit, ninety percent of the samplestaken over a specified period must not exceed the prescribed value, that is,the 90th percentile of the available data’s statistical distribution.NHMRC: National Health and Medical Research Council.NATA: National Association of Testing AuthoritiesNon-potable: Water not suitable for human consumption.Non-potable purposes: The use of water for purposes other than drinking,cooking, bathing and laundry; for example irrigation of gardens, lawns andtoilet flushing.NTU: Nephelometric Turbidity Unit – units of measure of the turbidity of waterdue to suspended solids using a nephelometre.NWQMS: National Water Quality Management StrategyOperator: The responsible person or organisation managing and operating arecycled water scheme.Passive Recreation: Recreational activities such as boating, picnicking orfishing that do not involve bodily contact with the water.Pathogens: Disease causing microbes eg viruses, bacteria, helminths andprotozoa.Potable Water: Water of a quality suitable for drinking, cooking, bathing andlaundry purposes.Primary contact recreation: Recreational activities involving immersion of aperson in water eg swimming, skiing, surfing.Primary treatment: The initial treatment which involves screening andsedimentation to remove gross and settleable solids.Public Drinking Water Source Areas (PDWSA): areas declared under theMetropolitan Water Supply, Sewerage and Drainage Act 1909, and theCountry Areas Supply Act 1947 for the management and protection of waterGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 58 of 66
  • 92. sources used for public drinking water supply. They include UndergroundWater Pollution Control Areas, Water Reserves and Catchment Areas.Recycled Water: Water derived from sewerage systems or industrialprocesses and treated to a standard that is satisfactory for its intended use.Also known as Recycled Water and Recycled Wastewater.Reuse: The utilisation of appropriately treated recycled water for some furtherbeneficial purpose.Risk: The likelihood of identified hazards causing harm in exposedpopulations in a specified time frame, including the severity of consequences.Risk Assessment: The overall process of using available information topredict how often hazards or specified events may occur (likelihood) and themagnitude of their consequences.RWQMP: Recycled Water Quality Management Plan.Secondary treatment: follows primary treatment and is typically regarded aslow rate stabilisation processes such as facultative lagoons orbiological/mechanical treatment such as biofiltration, trickling filter,intermittently decanted extended aeration (IDEA) or activated sludge plants.Sewage: Any waste containing human excreta or domestic wastewater.Spray irrigation: means the application of recycled water to crops to maintainvegetation or support growth of vegetation by applying it from sprinklers.Storage lagoon: A lagoon used to store treated recycled water prior toapplication.SS: Suspended Solids – the non filtrable residual solids which are suspendedin sewage or effluent. It is expressed in milligrams/litre (mg/L).Supplier: A person or organisation that supplies recycled water for use.Tertiary treatment: The treatment of wastewater beyond the secondarybiological stage. It normally implies the removal of a high percentage ofsuspended solids and/or nutrients followed by disinfection.Thermotolerant coliforms: A subset of coliforms found in the intestinal tractof humans and other warm blooded animals. Consists of chiefly Ecoli. Usedas an indicator of faecal pollution and effectiveness of disinfection processesand measured as a colony forming unit or cfu/100mL.Treatment lagoon: Any large pond or holding used to contain recycled waterwhile treatment processes including sedimentation and biological oxidationoccur. Stabilisation and maturation lagoons are examples of treatmentlagoons.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 59 of 66
  • 93. Uncontrolled access: (or open access) areas where recycled water is usedand public access is unrestricted.User: A person or organisation that uses recycled water.Water Quality: refers to chemical, physical, biological, bacteriological,radiological, and other properties and characteristics of water which affect itsuse.Wastewater: The used water of a community or industry collected andtransported through the sewerage system.WWTP: Wastewater Treatment PlantGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 60 of 66
  • 94. Appendix B: Application checklistSuggested checklist Type of reuse (including quantity and quality of recycled water used) Treatment, maintenance and water distribution reliability controls. Operations Manual Plan showing location of prominent warning signs in accordance with the principles of AS 1319 - Safety Signs for the Occupational Environment) and sensitive features within 200 metres of the reuse site Occupational health and safety controls. Spray drift controls (if relevant). Access controls – public and/or stock, including withholding periods (if relevant). Inspection and maintenance programs. Training program. Contingency plans. Recycled water monitoring program (including identification and measurement of chemical contaminants if significant trade waste present). Reporting program. Auditing program. Recycled water quality management plan.Irrigation schemes A 1:100 minimum scaled locality plan of the reuse site showing site characteristics (eg slope, soil, groundwater characteristics) and sensitive features within 200 metres of the irrigation boundary areas. Water budget (including irrigation scheduling). Irrigation method, operation and maintenance procedures. Winter storage requirements. Leaching controls. Groundwater controls if relevant. Drainage (if relevant) and stormwater run off and collection controls. Produce safety controls (if relevant). Receiving environment monitoring and reporting programs (including livestock monitoring program, if relevant).Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 61 of 66
  • 95. Appendix C: Approval Flow Chart RECYCLED SCHEME DOH approval (section 98 of Health Act 1911) Is the daily volume greater than 20m3/d? YES NO DEC works approval No further action(Category 85 sewerage facility)Is the daily volume greater than 100m3/d? YES DEC licence requiredDesignated LicensedSewerage Facility(Category 54 ofEnvironmental Protection Act)Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 62 of 66
  • 96. Appendix D: List of References(This list is not exhaustive, representing only key literature for further readingor reference.)AGWEST (1997) SQF 2000CM Quality Code: 1997. A HACCP Quality Codefor the Food Industry. 2nd edition, Aug 1997. AGWEST Trade andDevelopment, Agriculture, Western Australia.ANZECC (1992) Australian Water Quality Guidelines for Fresh and MarineWaters. National Water Quality Management Strategy. Australian and NewZealand Environment Conservation Council. Available atwww.deh.gov.au/water/qualityANZECC (1994) Guidelines for Sewage Systems Acceptance of TradeWastes (Industrial Wastes) National Water Quality Management Strategy.Australian And New Zealand Environment Conservation Council.ANZECC (1997) Australian Guidelines for Sewerage Systems – EffluentManagement. National Water Quality Management Strategy. Australian andNew Zealand Environment and Conservation Council, Agriculture andResource Management Council of Australia and New Zealand.ANZECC (2000) Guidelines for Sewerage Systems – Recycled Water.National Water Quality Management Strategy. Australian And New ZealandEnvironment Conservation Council, Agriculture And Resource ManagementCouncil Of Australia And New Zealand, National Health And MedicalResearch Council.ANZECC (2001) Australian New Zealand Guidelines for Fresh and MarineWater Quality. National Water Quality Management Strategy. Australian andNew Zealand Environment Conservation Council. Available at:www.environment.gov.au/science/water/index.html)Anzfa (1987-2000). Food Standards Code Schedule A12 Metals AndContaminants In Food. Incorporating amendments up to and includingAmendment 47 Nov./Dec. 1999. Originally published by the National Healthand Medical Research Council in the Commonwealth of Australia, Gazette,No. P27, 27 August 1987.ARMCANZ (1996) Australian Drinking Water Guidelines. National WaterQuality Management Strategy. Agriculture And Resource ManagementCouncil Of Australia And New Zealand, National Health And MedicalResearch Council.ARMCANZ (2000) Revision Of The Australian Drinking Water Guidelines.Public Consultation Document. National Water Quality Management Strategy.Agriculture And Resource Management Council Of Australia And NewZealand, National Health & Medical Research Council, June 2000.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 63 of 66
  • 97. Blumenthal UJ et al (2000) Guidelines For The Microbiological Quality OfTreated Wastewater Used In Agriculture: Recommendations For Revising TheWHO Guidelines. Blumenthal U.J., Mara D.D., Peasey A., Ruiz-Palacios G.and Stott R. Bulletin of the World Health Organisation (WHO) 2000, 78(9), pp1104-1116.CAC 1997, Hazard analysis and critical control point (HACCP) systems andguidelines for its application. Annex to CAC/RCP 1-1969, Rev 3, CodexAlimentarius Commission, Geneva.CSIRO (1995) Effluent Irrigated Plantations: Design and Management. CSIRO(Division of Forestry) Technical Paper No.2, Canberra 1995.CSIRO (1999) Sustainable Effluent-Irrigated Plantations. An AustralianGuideline. CSIRO Forestry and Forest Products, Land and Water, Canberra1999. Available at: www.ffp.csiro.au/pff//effluent_guideline/Cunliffe D. & Stevens M. 2003, Success of HACCP in the drinking waterindustry – can it be adapted to reuse schemes? Proceedings of 2nd NationalWater Recycling Conference, Brisbane, September 2003.DHS South Australia (1999) Recycled Water Guidelines, Treated Effluent.Department of Human Services and Environment Protection Agency.Adelaide, South Australia. Available at:www.environment.sa.gov.au/epa/pdfs/recycled.pdfDPH & DFA (1992) Code of Practice Piggeries. Department of Planning andHousing (DPH), Department of Food and Agriculture (DFA), Revised 1992.EPA Victoria (2002) Guidelines for Environmental Management: Use ofRecycled Water, Publication 464, August 2002, Victoria.EPA Victoria (2003) Environmental Guidelines for the Disinfection of RecycledWater, Publication No. 730.1, Victoria.EPA Victoria (2005) Dual Pipe Water Recycling Schemes – Health andEnvironmental Risk Management, Consultation Draft, Publication 993, May2005, Victoria.Feacham R.G. et al (1983) Sanitation and Disease: Health Aspects of Excretaand Wastewater Management.Feacham R.G., Bradley D.J., Garelick H. and Mara D.D. World Bank Studiesin Water Supply and Sanitation 3. Published for World Bank by John Riley andSons.Fegan N., Gardner T. and Blackall P. (1998) Health Risks Associated WithThe Reuse Of Effluent For Irrigation. A literature review. State of Qld Dept ofNatural Resources, Dept of Primary Industries.Guidelines for the use of Recycled Water in Western Australia -30/08/06 Page 64 of 66
  • 98. Mara D. and Caincross S. (1989) Guidelines For The Safe Use OfWastewater And Excreta In Agriculture And Aquaculture. Published by theWorld Health Organisation in collaboration with the United NationsEnvironment Programme.National Academy of Sciences (1996) Use of Recycled Water and Sludge inFood Crop Production. Committee on the Use of Treated MunicipalWastewater Effluents and Sludge in the Production of Crops for HumanConsumption. Water Science and Technology Board. Commission onGeosciences, Environment and Resources.National Research Council. National Academy Press, Washington DC, USA,1996. NRA (2000). “MRL Standard”. Maximum Residue Limits Of AgriculturalAnd Veterinary Chemicals And Associated Substances In Food Commodities.National Registration Authority for Agricultural and Veterinary Chemicals(NRA) Available at: www.affa.gov.au:80/nra/mr11.html.NRE (2000) Draft Code of Practice Piggeries. November 2000 draft for publicconsultation. Department of Natural Resources and Environment.NRMMC/EPHC in draft, National Guidelines for Water Recycling: ManagingHealth and Environmental Risks Natural Resource Management MinisterialCouncil/Environment Protection and Heritage Council, Canberra.NSW Recycled Water Coordination Committee (1993) “NSW Guidelines forUrban and Residential Use of Recycled Water”, 1st Edition, May 1993Queensland EPA (2004) Queensland Guidelines for the Safe use of RecycledWater, Public Consultation Draft. Available at:http://www.epa.qld.gov.au/environmental_management/water/safe_use_of_recycled_water/Standards Australia (1997) Australian Standard. Guide To The Sampling AndInvestigation Of Potentially Contaminated Soil. Part 1: Non-Volatile And Semi-Volatile Compounds. AS 4482.1 – 1997. Standards Australia, Homebush,NSW. Available at: www.standards.com.auShuval H. et al (1997) Development Of A Risk Assessment Approach ForEvaluating Wastewater Reuse Standards For Agriculture. Shuval H., LampertY. and Fattal B. Water Science & Technology, Vol. 35, No. 11-12, pp15-20,1997.Toze S. (1997). Microbial Pathogens in Wastewater. Literature Review forUrban Water Systems Multi-divisional Research Program. CSIRO Land andWater Technical Report No 1/97. Available at:www.clw.csiro.au/publications/technical/tr1-97.pdfGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 65 of 66
  • 99. US EPA (1992) Manual - Guidelines for Water Reuse. Technology Transfer,EPA/625/R-92/004, Sept 1992. United States Environmental ProtectionAgency.VDIA (1999) Recycled Water on Dairy Farms. General Information andRequirements for Users. Victorian Dairy Industry Authority (VDIA), Abbotsford,VictoriaWSAA 2004, Health Risk Assessment of Fire Fighting from Recycled WaterMains Water Services Association of Australia Occasional Paper No. 11,November 2004. Available at: www.wsaa.asn.auGuidelines for the use of Recycled Water in Western Australia -30/08/06 Page 66 of 66

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