International Workshop on Sustainable Sanitation

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INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION

RESOURCE PAPERS

AT THE MONTEVERDE INSTITUTE COSTA RICA JULY 16-20, 2002

HOSTED BY

MONTEVERDE INSTITUTE

IN COLLABORATION WITH

INTERNATIONAL WATER ASSOCIATION (IWA) FOUNDATION (UK)

MURDOCH UNIVERSITY ENVIRONMENTAL TECHNOLOGY CENTRE (ETC)

UNITED NATIONS ENVIRONMENTAL PROGRAM - I NTERNATIONAL ENVIRONMENTAL TECHNOLOGY CENTRE (UNEP – IETC) International Workshop on Sustainable Sanitation 16-20 July, 2002 Resource Papers

Editors Professor Goen Ho Dr Kuruvilla Mathew Mr Peter Stuart

Murdoch University Environmental Technology Centre Murdoch WA 6150 AUSTRALIA

+61 8 9360 7310 [email protected] wwwies.murdoch.edu.au/etc

2002 ETC Murdoch University ISBN 0-86905-825-8 CONTENTS

FOREWORD 1

01 ON-SITE WASTEWATER TREATMENT & REUSE TECHNOLOGY OPTIONS IN 2 AUSTRALIA G. HO, S. DALLAS, M. ANDA & K. MATHEW

02 EVAPOTRANSPIRATION FOR DOMESTIC WASTEWATER REUSE IN REMOTE 15 INDIGENOUS COMMUNITIES OF AUSTRALIA M. ANDA, K. MATHEW & G. HO

03 GREYWATER REUSE: METHODS AND DIRECTION FOR POSSIBLE FUTURE 31 DEVELOPMENTS IN AUSTRALIA M. ANDA, K. MATHEW & G. HO

04 INTEGRATED HOUSEHOLD WASTE MANAGEMENT SYSTEMS USING 47 VERMICULTURE K. MATHEW, M. ANDA & G. HO

05 PRINCIPLES OF WATER AUDITING IN THE CONTEXT OF WATER CONSERVATION 62

J. J. STURMAN, K. MATHEW & G. HO

06 THE H2S METHOD FOR TESTING BACTERIOLOGICAL QUALITY OF DRINKING 71 WATER IN REMOTE COMMUNITIES J. NAIR, K. MATHEW & G. HO.

07 ABOUT THE MONTEVERDE INSTITUTE 77

08 ABOUT THE MURDOCH UNIVERSITY ENVIRONMENTAL TECHNOLOGY CENTRE 77 FOREWORD

The International Workshop on Sustainable Sanitation is based on the recently published book: Environmentally Sound Technologies in Wastewater and Stormwater Management: An International Sourcebook. We are pleased that an Abridged Version of this book has been translated into Spanish for use in this workshop.

The Environmental Technology Centre, at Murdoch University, has been involved in the preparation of the International Sourcebook and the Abridged Version. In addition we have been involved in developing and providing technologies for remote indigenous communities in Australia as well as developing communities around the globe. We have included papers describing our work, which we want to share with participants of the workshop.

We are grateful to the International Water Association Foundation, which has provided funding for us to be able to conduct this workshop. We conducted a similar workshop for the Foundation in Johannesburg, South Africa, May 2002. We are also grateful to the International Environmental Technology Centre for sponsoring participants from Central America to attend this workshop. Again we have conducted and facilitated workshops for the Centre in Perth - Australia (1997), Montego Bay - Jamaica (1998), Rio de Janeiro – Brazil (2000) and Melbourne – Australia (2002).

We would also like to acknowledge the support and help given by the Monteverde Institute in conducting this International workshop.

Our hope is that as we share knowledge and experiences we can together provide solutions for the need of those without adequate sanitation.

Goen Ho & Kuruvilla Mathew Director/s – Environmental Technology Centre Murdoch University Perth Western Australia July 2002

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ON- SITE WASTEWATER TREATMENT & REUSE TECHNOLOGY OPTIONS IN AUSTRALIA

G. HO, S. DALLAS, M. ANDA & K. MATHEW

ABSTRACT

Domestic wastewater reuse is currently not permitted anywhere in Australia but is widely supported by the community, promoted by researchers, and improvised by up to 20% of householders. Its widespread implementation will make an enormous contribution to the sustainability of water resources. Integrated with other strategies in the outdoor living environment of settlements in arid lands great benefit will be derived. This paper describes six options for wastewater reuse under research by the Remote Area Developments Group (RADG) at Murdoch University and case studies are given where productive use is being made for revegetation and food production strategies at household and community scales. Pollution control techniques, public health precautions and maintenance requirements are described. The special case of remote Aboriginal communities is explained where prototype systems have been installed by RADG to generate windbreaks and orchards. New Australian design standards and draft guidelines for domestic greywater reuse produced by the Western Australian state government agencies for mainstream communities are evaluated. It is recommended that dry composting toilets be coupled with domestic greywater reuse and the various types available in Australia are described. For situations where only the flushing toilet will suffice the unique “wet composting” system can be used and this also is described. A vision for household and community-scale on-site application is presented.

1. INTRODUCTION

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(Race Discrimination Commissioner, 1994). Indeed, the arguments for abandonment of this paradigm in favour of one which cycles nutrients and resources for sustainability are perhaps now as evenly matched against the status quo as they were in the last century when the 'water carriage' lobby narrowly defeated the 'dry conservancy' lobby (Beder, 1993). The latter then also sought separation at source with reuse of dry and liquid products for agriculture although with much less scientific basis than what is available today. Goodland and Rockefeller (1996) proposed three general principles to enable the passage of the new sustainable paradigm: a) cease expansion of sewers and commence decommissioning them; b) promote on-site recycling systems that avoid pollution of water resources; and c) charge the true value of water. In Australia today there is little evidence that (a) is underway in urban centres; however (b) is well underway; and there is certainly discussion of (c) in the prevailing climate of economic rationalism. The focus of this paper is on-site recycling systems.

Reuse of wastewater occurs most effectively with on-site (localised) or small-scale treatment systems. A major study of Perth's wastewater management (WAWA, 1994) made it clear that it was not possible to reuse all the effluent from centralised treatment plants in the sewered suburban sprawl of Perth - there simply was not enough land for nearby broadacre application. Thus to achieve the goal of total reuse the involvement of a local community in the urban situation would have to be be enabled and reuse options in the local context agreed upon. In sewered areas greywater reuse can still be implemented on-site. Greywater or sullage is effluent from the bathroom, washbasin and laundry, and for primary systems should exclude kitchen sink wastewater as it carries oils and high BOD. The more concentrated blackwater (from the toilet) can still go to the sewer along with kitchen effluent. In unsewered areas the blackwater can be treated separately or dry vault (pit or composting) systems utilised. Greywater reuse can result in cost savings (to both the consumer and state water authority), reduced sewage flows in sewered areas and potable water savings of more than 40% when combined with sensible garden design.

Significant impact on water and energy use might require greywater reuse to be coincidental with water-sensitive urban design, reduced lawn area, and possibly the growing of food at home and in public open space. There is immense community support for reuse of wastewaters (WAWA, 1994). This paper will review regulatory developments, describe six methods under research by the Remote Area Developments Group (RADG), present options for the three broad soil types in which trials are

3 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS currently occurring and for remote Aboriginal communities, and explain the broader design approach that needs to be applied with greywater reuse.

2. CURRENT REGULATION

Domestic greywater reuse, governed by state and local government health acts, is currently not allowed in any of the Australian states although WA state authorities acknowledged that 20% of householders engaged in this practice in Perth (Lugg, 1994; Stone, 1996). In Queensland three options were developed for possible implementation (Department of Primary Industries, 1996). The model guidelines for domestic greywater reuse in Australia (Jeppeson, 1996) covered hand basin toilets, primary greywater systems (direct subsurface application) and secondary greywater systems (mesh, membrane or sand filtration prior to irrigation). For primary systems the guidelines have adopted the Californian approach requiring the use of a surge tank with a screen to remove lint and hair. Electrical power is therefore required for the automatic pump system and weekly inspection and clearing of the screen. The need for maintenance to these components by the householder resulted in some 80% of Californian systems being in an unsatisfactory condition. The recommendation of this approach as the solution for Australia is questionable. The updated standard AS1547- 1994 guiding domestic effluent management (Standards Aust./NZ, 1996) is significantly more progressive in providing design criteria for a range of treatment systems with reuse and opening the way for further innovation.

Treated effluent from centralised plants is used on municipal ovals, parks and golf courses in many country towns of WA (Mathew & Ho, 1993). In New South Wales (NSW) treated effluent from centralised plants is allowed in urban areas (NSW Recycled Water Coordination Committee, 1993). National guidelines for the use of reclaimed water via dual reticulation have been prepared (National Health & Medical Research Council, 1996). The level of treatment recommended is secondary plus filtration and pathogen reduction. Alternatives to this include constructed wetlands which may achieve treatment equivalent to open water areas which will allow pathogenic die-off due to UV sterilisation.

In 1996 the WA Government released its Draft Guidelines for Domestic Greywater Reuse (HDWA, 1996) which allow the public to install greywater reuse systems in three shires as a means of conducting trials for 12 months (Fimmel, 1997). The three shires

4 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS provided different soil types which would no doubt call for different design responses to pollution control and absorption: Bassendean (sands and coarse sandy clay); Kalamunda (shallow soil over rock in hills plus alluvial clay soils lower down on plain); and Kalgoorlie-Boulder (fine silty clay soils). Moreover many dwellings in these areas were unsewered. Funding would not be provided for the trials and the systems proposed would need to gain approval from the WA Health Department prior to installation. With the shire Environmental Health Officers as the public's first point of contact in seeking information and approvals they would need to receive comprehensive training.

The Western Australian State Government agencies quite rightly wants to move ahead and respond to the massive public interest in greywater reuse while at the same time exercising caution after the early Californian experience. The three shire trial will provide broad experience if a range of systems are allowed. The monitoring of these will provide invaluable information: Which systems are most appropriate for each of the conditons? How effective are the local government authorities in providing support and direction? How diligent are householders in maintaining these systems? What are the economic benefits? How effectively are greywater systems integrated into the landscape in relation to productivity and nearby recreation? What are the longer term effects on soil and plants? What is the nutrient balance between inputs, plant uptake, and percolation into the soil?

Experience does need to be gained for local conditons but there is a considerable body of literature for the trial shires to draw from. For example, there are McQuire (1995), Kourik (1995) and Ludwig (1994) for general interest while for contractors and do-it- yourself enthusiasts there are Jeppeson (1996) and Ludwig (1995). The design criteria provided in Standards Australia (1994) reflect the disposal paradigm while its revised version prepared with New Zealand authorities released as a draft only in 1996 allows for significant innovation.

3. SYSTEM CHARACTERISTICS

A greywater reuse system needs to protect public health, protect the environment, meet community aspirations and be cost-effective. Current on-site treatment systems have generally adopted the technology of the conventional activated sludge plant for large treatment systems. If removal of nutrients is required for installation of on-site units in

5 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS nutrient-sensitive catchments, phosphorus (P) can be removed by alum dosing and nitrogen (N) by nitrification and denitrification in separate chambers or by intermittent aeration of a modified activated sludge set-up.

If the effluent is used for irrigation of garden plants there is the question as to why N and P should be removed. There may be an imbalance between plant requirement for the nutrients and the seasons, with a higher requirement in the warmer months than the colder months. Rather than removing the nutrients an alternative is to store the nutrients in the soil. Soils containing clay have the capacity to sorb ammonium and phosphate present in secondary effluent. Sandy soils can be amended with clay, loam or if convenient the 'red mud', bauxite-refining residue. The most progressive application of domestic greywater reuse appears to be in California. But even here the minimum prescribed depth of 430 mm for subsurface irrigation "ignore(s) the importance of aerobic bacteria and biota (found in profusion in the top few inches of garden soil) for digesting organic matter, nutrients and possible pathogens found in graywater" (Kourik, 1995).

4. SIX OPTIONS CURRENTLY UNDER RESEARCH FOR WESTERN AUSTRALIA

4.1 Amended Soil Filter Fremantle Inner City Agriculture (FINCA) developed an 800 square metre community garden and is using the greywater from two adjacent houses to irrigate it. This is part of a water-sensitive, permaculture design approach which also involves harvesting rainwater from the two houses' roofs, heavy mulching and appropriate, low water use species selection for growing food in a perennial polyculture. Design and sizing of the system was generally in accordance with AS1547-1994 but performance monitoring and resident behaviour to date indicates the system is over-sized.

Greywater from the two houses enters a collection tank in the park by gravity. The duty field is a variation of the 'Ecomax' principle (Bowman, 1996) comprising two laterals of 20 m x 1.2 m and 25 m x 1.2 m wide. The plastic lined trenches are filled with a mix of 85% red sand and 15% red mud (with 5% gypsum in the latter to neutralise its alkalinity). The red mud and sand are by-products of bauxite refining to alumina. P is adsorbed into this clay material and N is removed from the system by intermittent drying and wetting causing nitirification-denitrification. Pathogens are filtered and die off. The field is heavily vegetated causing significant nutrient uptake and transpiration.

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Soil analyses to date indicate there is capacity for heavier liquid and nutrient loading and sludge build-up in the tank is negligable, i.e. application of AS1547-1994 design criteria resulted in over-sizing to the detriment of plant growth.

4.2 Sand Filtration The Envirotech system consists of a receival tank where settling of solids occurs, and a second chamber into which the effluent flows. When this is full effluent is pumped to the top of a deep-bed plastic-lined sand filter. Effluent filters to the bottom of this device under gravity and flows back to a third chamber of the tank, from where the treated effluent is pumped to the irrigation field. General practice is to chlorinate in this final chamber, although it may not be necessary for subsurface irrigation. Systems are being installed in NSW and Indonesia. A system based on Envirotech sand filtration for greywater reuse is now designed and awaiting installation by RADG at a WA site with Health Department approval.

4.3 Wet Composting The Dowmus vermicomposting toilet system can be upgraded to receive wastewaters - both blackwater and greywater (Cameron, 1994). In Canberra, ACT about 12 households have had trial systems installed for monitoring by Australian Capital Territory Electricity and Water (ACTEW) (Anon, 1996). Blackwater from the toilet enters a wet composting Dowmus tank and from there effluent goes to a second tank where greywater is also received. In this tank effluents are aerated around submerged volcanic rock media to achieve secondary standard treated effluent. From there the effluent goes to an irrigation storage tank in which chlorination occurs. The final effluent is mixed with rainwater to achieve further dilution and to improve the quality of water. Dowmus has been authorised to install five systems in WA for trial. One will be established at Murdoch University in the Environmental Technology Centre's permaculture system.

4.4 Constructed Wetlands Mars (1996) is conducting a comparative trial on the effectiveness of the submergent aquatic plant Triglochlin hueglii and the emergent sedge Schoeneplectus validus in constructed wetlands for greywater treatment. Each of these species are reported to have a high (“luxury”) nutrient uptake capacity. The former species is used in a surface flow wetland and the latter in a subsurface flow wetland. The aim is not only to verify

7 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS treatment capability, but to use these local native species in a sustainable polyculture arrangement to produce food, thatching material, fodder and paper-making feedstock. Results to date are being published separately.

4.5 Modified aerobic treatment unit In Cottesloe, Western Australia, also a sewered suburb, a greywater reuse system that utilised the Biomax aerobic treatment unit was approved and installed in May 1996. Additional baffles have been installed in the anaerobic and aerobic chambers to enable more effective treatment of the lower biomass effluent input (c.f. combined blackwater and greywater). Effluent is irrigated to the front and back yards via 'Dripmaster' subsurface tubing. Monitoring is currently underway to evaluate the performance with the reduced biomass as a result of greywater influent only. Results to date appear to indicate that there is often not a significant reduction in BOD, SS and nutrient levels across the unit. There has been a similar experience with other aerobic treatment units. Research is being conducted to determine what improvements to the system design will be necessary.

4.6 Evapotranspiration systems Evapotranspiration (ET) systems can be used in those areas where soil is comprised of more silts and clays and absorption fields have failed. These systems cost considerably less and require less maintenance than reticulated systems with lagoons (McGrath et al., 1991). Effluent disposal in the ET trench occurs primarily by soil evaporation and plant transpiration rather than soil percolation - as occurs in conventional leach drains. The trench essentially comprises a layer of gravel for distribution of effluent below a layer of river sand through which capillary action to the surface occured and in which plants grew.

ET systems receiving all domestic wastewater were installed in Aboriginal communities with community participation at Kawarra (McGrath, Ho & Mathew, 1991), Kalgoorlie, Irrungadji (McGrath, 1992), Halls Creek and Parnngurr School in the Western Desert. Systems in use in the clay soil shires of Perth including Kalamunda, were often inverted to some extent relying largely on evapotranspiration. The RADG ET system was developed to also improve the performance of these (McGrath, Ho & Mathew, 1990). Systems taking greywater only (alongside composting toilets) were installed at Tjuntjuntjarra in mid-1997 with a design intent of supporting native revegetation and orchards. In each case no problems were reported and in some, e.g. Halls Creek,

8 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS vegetation planted on the fields is flourishing. Most importantly, no cases of ponding have been reported - one of the main reasons for developing this technology. It would be desirable, however, to conduct monitoring of performance over a longer period on these systems. They had generally been installed to the same size as leach drains to gain approval. Comparative monitoring with conventional leach drains would quantify the reduced size possible as a result of the better performance of ET systems and thereby reduce costs and improve irrigation of plants.

Ross Mars' system in the Perth hills suburb of Hovea referred to in Appendix 1 of HDWA (1996) is an 'absorption trench' that conforms with AS1547 and relies largely on evapotranspiration and to a lesser extent on absorption in the clay soil. The sand cover over the whole field of 7m x 7m interconnected piped trenches at 1500 centres is heavily vegetated with the high water demand plants sugar cane, banana, banna grass, canna lilly and vetiver grass. The system has performed satisfactorily without ponding since it was installed in 1994.

5. PROPOSED SYSTEMS FOR EACH SOIL TYPE

For cost-effectiveness and to most readily enable effluent reuse the followigng systems are recommended with respect to soil types:

Sand: modified aerobic treatment units; amended soil filters; sand filters; constructed wetlands (avoidance of groundwater pollution). Clay: evapotranspiration trenches (avoidance of ponding) Rocky slopes: inverted evapotranspiration systems, sand filters (avoidance of run-off)

The key problem to be overcome in each case is indicated in brackets. Wet or dry composting toilets can be used in conjunction with any of the above.

6. REMOTE ABORIGINAL COMMUNITIES

There are unique design considerations in the remote Aboriginal community setting. Unlike many of the large urban areas of Australia remote Aboriginal communities in arid lands do not have a diverse range of water sources. Typically there are groundwater sources whose sustainability in the face of growing populations is uncertain. At Coonana, for example, water shortages have been extreme (Race

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Discrimination Commissioner, 1994). However, there is poor public health in some communities and any reuse proposal needs to take serious consideration of this factor. Nevertheless, wastewater reuse can lead to improved public health. Separation of greywater and blackwater enables decreased loading on treatment systems and therefore results in greater reliability and performance. Dust control is accepted as necessary to alleviate disease, e.g. trachoma, which can be achieved through revegetation. Irrigation systems to establish trees use valuable potable water, are expensive and maintenance intensive. Greywater reuse evapotranspiration systems can be designed for low-cost, durability and low maintenance with sub-surface, gravity- feed, PVC piping.

Wastewater disposal systems often account for a major maintenance cost in remote Aboriginal housing and this is often because of poor initial construction by non- Aboriginal contractors (Pholeros, Rainow & Torzillo, 1993). A holistic response for on- site systems is necessary including separation of blackwater and greywater, use of evapotranspiration instead of absorption, interconnection of houses and systems to spread peak loads, back-up pit toilets to each house to cater for system failure, overcrowding and solids reduction, productive use of treated effluent, strict supervision of below-ground construction works, and effective management and maintenance.

In WA evapotranspiration systems are now fairly common in remote communities with tight soils since RADG commenced their implementation (McGrath, Ho & Mathew, 1991). Composting toilets have been installed at Wilson's Patch in the Goldfields and by Winun Ngari Resource Agency in the West Kimberley. Greywater reuse was recommended for Tjalku Wara in the Pilbara (Swanson, 1996) and a design using evapotranspiration was prepared by a regional permaculture practitioner. A trial greywater reuse system relying on evapotranspiration was approved for Frog Hollow in the East Kimberley (Kinnaird, 1997). However, the tendency has been to install deep sewerage to lagoons when funds become available rather than attempt to implement all of the above principles for a holistic response simultaneously. On-site and community- scale systems using one or more of the above six options need to be established in remote communities for research into their appropriateness and not just their technical suitability. In most cases, however, evapotranspiration systems will be appropriate and these can be adapted for simpler greywater reuse in parallel with blackwater septic systems or dry vault toilets.

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Studies were completed for wastewater reuse from lagoons at Warralong and Jigalong in the Pilbara (Mathew & Ho, 1993). There was insufficient wastewater produced for irrigation of a football oval. Groundwater recharge was an option. The most suitable options were revegetation, orchards and vegetable gardens by subsurface or drip irrigation. If surface irrigation was proposed some form of disinfection to eliminate pathogens and enclosed storage to eliminate algae would be necessary. Reuse direct from lagoons could be subsurface from the overflow after the last lagoon or pumped from the lagoon to storage for later irrigation.

7. HOLISTIC DESIGN

Many concerns have been raised in relation to widespread implementation of greywater reuse without proper management or maintenance: reduced sewer flows, higher concentrations at treatment plants, public health risks, groundwater contamination, mosquito breeding in constructed wetlands, flooding during winter rainfall, sludge build-up and blockages. However, there is another issue for concern that may lead to some of these problems and others indirectly: poor design (or no design). Not just the design of the system itself but the manner by which the system is integrated into the landscape. Australian standards such as AS 1547 do, for example, specify minimum setbacks from houses and lot boundaries, provide ways of avoiding inundation and give design criteria for terraced disposal fields on slopes.

There are very few practical design methodologies that may serve the case of placement of a greywater recycling system in the house yard or community landscape. Two examples are: * hydroscaping(Colwill, 1996) for sustainable garden aesthetic design; and * permaculture (Mollison, 1988) for sustainable food production system design.

Hydrozoning will allow the placement of the greywater system in accordance with a garden layout designed for aesthetics and plant groupings of similar water needs.

Permaculture draws on a wider range of design tools including zoning for energy efficiency and sector analysis of the natural elements affecting the site (sun, wind, fire, view). Zones 1 to 5 in permaculture refer to areas of planting types (intensive salad beds, low maintenance orchards, through to natural bushland) placed in relation to

11 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS house or settlement according to frequency of visits. Design with sectors allows the appropriate placement of windbreaks, shadetrees, water tanks, zones and other elements in the landscape.

The use of a design approach prior to installation enables placement of the greywater system in a landscape with respect to the vegetation type that it will support and its position in relation to other elements and natural influences on the site. If such considerations are ignored with a focus merely on the technical design of the system itself then improper management and maintenance and poor performance may still be the longer term outcome.

8. CONCLUSIONS

For the urban village, small country towns, or group housing a greywater reuse system utilising secondary treatment and disinfection maintained by a supplier may be most appropriate. For on-site greywater recycling at individual houses in a low-density settlement or remote community a primary system with large diameter subsurface irrigation 300 mm below the surface is appropriate using evapotranspiration in soils of low permeability. Filters, pumps and treatment units should be avoided as these may not be adequately maintained by the owner/occupier. Reuse from lagoons is commonly practiced in WA country towns. If nutrient removal is necessary a treatment system such as Aquarius or Ecomax with sufficient vegetation to utilise the nutrient is ideal. Data-gathering on the long term effects of greywater on plants and soils and their nutrient uptake capacity is necessary. Field trials are necessary to optimise the irrigation fields for plant growth, particularly in the case of food species. Evapotranspiration systems, for example, have typically been designed too deep in the past for this purpose. A standard code of practice on greywater reuse should be adopted. If managed correctly wastewater reuse in remote Aboriginal communities can not only result in water savings but also improved public health through dust suppression from revegetation, improved nutrition from locally grown food, and less system failures from decreased loading on treatment systems.

9. REFERENCES

Anon (1996). Small-scale Systems Halve Water Use, Waste Management and Environment, 8, 18 - 20.

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Beder, S. (1993). Pipelines and Paradigms: The development of sewerage engineering, Australian Civil Engineering Transactions, CE35, ( 1), 79 - 85. Bingley, E. B. (1996). Greywater Reuse Proposal in Relation to the Palmyra Project, Desalination, 106, 371 - 375. Bowman, M. (1996). On-site Tertiary Treatment Using Ecomax Systems, Desalination, 106, 305 - 310 Cameron, D (1994), Compost Filtration: A new approach to on-site resource management, in Mathew K & Ho G (eds), Workshop on Localised Treatment and Recycling of Domestic Wastewater, RADG, Murdoch University. Colwill J (1996), The Waterwise Garden and How to Create One, Water Authority of WA, Perth. Department of Primary Industries (1996), Policy Options Paper - The Use of Greywater, Brisbane. Fimmel, B (1997), personal communication. Goodland R & Rockefeller A (1996), What is Environmental Sustainability in Sanitation?, Insight, UNEP-IETC Newsletter, Summer. Health Department of WA (1996), Draft Guidelines for Domestic Greywater Recycling, Water and Rivers Commission, Perth. Jeppeson, B. (1996). Model Guidelines for Domestic Greywater Reuse for Australia, Research Report # 107, Urban Water Research Association of Australia, Melbourne. Kinnaird M (1997), pers. comm., Environmental Health Officer, Shire of Halls Creek. Kourik, R. (1995). Graywater for Residential Irrigation, Landscape Architecture, 85 (1), 30- 33. Lugg, R. (1994). Health Controls on Wastewater Reuse, in Mathew K & Ho G (eds), Workshop on Localised Treatment and Recycling of Domestic Wastewater, RADG, Murdoch University, Perth. Mars R (1996), Using Submergent Macrophytes for Domestic Greywater Treatment, in Mathew & Ho (eds), Workshop on Wetlands for Wastewater Treatment, September 25, Murdoch University. Mathew K & Ho G (1993), Reuse of Wastewater at Jigalong Aboriginal Community, RADG, Murdoch University. McGrath D R (1992), Installation ofEvapotranspiration Systems at Irrungadji Community, Nullagine, McGrath D, Ho G & Mathew K (1990), On-site Wastewater Disposal in Clay Soils - The Use of Evapotranspiration Systems and Conventional Methods, in Mansell, Stewart & Walker (eds), Proceedings of the UNESCO Regional Seminar on Technology for

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Community Development in Australia, South-East Asia and the Pacific, Alice Springs, 9-11 July, Development Technologies Unit, University of Melbourne/Centre for Appropriate Technology. McGrath D R (1991), Installation of Evapotranspiration Systems at Irrungadgi Community, Nullagine, RADG, Murdoch Universiy. McGrath D, Ho G & Mathew K (1991), The Effectiveness of Evapotranspiration Systems in Disposing of Wastewater in Remote Aboriginal Communities, Water Science and Technology, 23, 1825-1833. Mollison Bill (1988), Permaculture: A designer's manual, Tagari Publications, Tyalgum. National Health & Medical Research Council (1996). Draft Guidelines for Sewerage Systems - Use of Reclaimed Water, National Water Quality Management Strategy, Melbourne. New South Wales Recycled Water Coordination Committee (1993). New South Wales Guidelines for Urban and Residential Use of Reclaimed Water, Public Works Department, Sydney. Newman, P. W. G. and Mouritz, M. (1996). Principles and Planning Opportunities for Community Scale Systems of Water and Waste Management, Desalination, 106, 339 - 354. Niemczynowicz, J. (1993). Water Management and Ecotechnology - towards 2020, Workshop on Sustainable Urban Water Systems and Ecotechnology, November 18, ISTP/RADG, Murdoch University, Perth. Pholeros, Rainow & Torzillo (1993), Housing for Health: Towards a healthy living environment for Aboriginal Australia, Health Habitat, Sydney. Race Discrimination Commissioner (1994), Water - A report on the provision of water and sanitation in remote Aboriginal & Torres Strait Islander Communities, HREOC, AGPS, Canberra. Standards Australia/NZ (1996). On-site Domestic Wastewater Management, AS/NZS 1547-Draft, Homebush/Well. Stone, R. (1996).Water Efficiency Program for Perth, Desalination, 106, 377 - 390. Swanson T (1996), Tjalku Wara Community: Wastewater Disposal Scheme, Gutteridge Haskins & Davey, Perth. Water Authority of Western Australia (1994). Wastewater 2040 Discussion Paper, WAWA, Perth

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EVAPOTRANSPIRATION FOR DOMESTIC WASTEWATER REUSE

IN REMOTE INDIGENOUS COMMUNITIES OF AUSTRALIA

M. ANDA, K. MATHEW & G. HO

ABSTRACT

In the past sewage ponding in indigenous settlements was commonplace as a result of overcrowding combined with inappropriate septic tank and leach drain design, installation and operation. The response over the past 10 years has been to develop reticulated sewerage systems to lagoons when the funds become available. These are often successful in terms of operation, improved public health, and low-maintenance but are expensive and wasteful of limited water supplies. Evapotranspiration is an effective method for on-site domestic effluent disposal in areas of Western Australia with soils of low permeability. Evapotranspiration systems have been established in a number of communities both for research/demonstration and as specified by architects. The systems usually follow two septic tanks for the disposal of all domestic effluent. A case study will be presented for a remote indigenous community where the ET systems installed for greywater only have been monitored over the last two years since installation. The use of evapotranspiration has enabled reuse of effluent for successful examples of revegetation and food production and points to the need for a holistic approach to design and service delivery in these communities that includes a total environmental management plan.

1 INTRODUCTION

This paper represents continuing investigations into the use of evapotranspiration (ET) for on-site effluent disposal or reuse in remote Indigenous communities and follows on from the early research by the Remote Area Developments Group (RADG) (McGrath, Ho & Mathew, 1990 & 1991) where simulations and field trials established design criteria for local conditions. The objective of the present study was to describe the experience with systems installed since that time, some new approaches in the application of ET, and further research and development that may be necessary.

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2 BACKGROUND

In assessing the ecological sustainability of nutrient and hydraulic loading rates with on-site effluent treatment systems, Gardner, Geary & Gordon (1996) explained that for septic tank systems allotment sizes of up to 1 hectare maybe required for a single household. However, for transpiration and aerobic treatment systems the area could be considerably less with up to 4,000 square metres being required.

The trend for sewerage technology in remote Indigenous communities has been a shift from on-site septic tank systems to reticulated systems with lagoons. The motivating factor for this mode of technology-practice has been public health and not environmental degradation.

Overcrowding in houses or fluctuating household populations often resulted in flooded leach drains. Irrespective of the number of houses in an indigenous settlement, occasions will always arise where there is a large number of people residing in the house for up to several months at a time. The leach drains were often installed in soils of low permeability with the same design criteria as those used for non-Indigenous urban centres. Sometimes the entire system had been installed incorrectly: no connection to the house, no leach drains installed after tanks, incorrect grades. Moreover, the on-site systems were often not maintained to the level required. (The same has often occurred in non-Indigenous urban centres). For example, equipment or trained personnel were not always available for septic tank pump-out, or diverter valves were installed without the community’s knowledge and not used. Thus the common sewer is advantageous in this situation. However, there has also had an economic incentive. On-site systems were normally included in State Government housing budgets. Centralised systems were seen to be superior and were included in Federal Government infrastructure budgets. Consequently the Commonwealth- funded, large, centrally-controlled capital works programs have tended towards installation of sewers to lagoons. These are also the preference of the large engineering consulting firms contracted by the Commonwealth Government’s Aboriginal & Torres Strait Islander Commission for reasons of professional experience as well as the aforementioned reasons.

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A survey by the Centre for Appropriate Technology (Marshall & Lloyd, 1998) of sewerage systems in Indigenous communities across Australia found that all of the typically used technologies of wastewater management were adequate but it was the installation, operation and maintenance where the problems arose. The Centre has found this to be generally the case for all technology systems transferred to Indigenous communities, i.e. delivery of physical infrastructure was the primary focus rather than local or regional capacity-building. Their study presented many other wastewater technology options for consideration, with recommendations for a number of those not yet used in remote communities to be trialed; for example, novel absorption trenches and simple greywater recycling systems.

Preferences by indigenous people toward a more dispersed settlement layout has been well documented (Morel and Ross 1993, Moran 1997) with a number of well-spaced clusters (each consisting of some 5-10 houses) often being considered a more appropriate form of layout. Such a layout lends itself better to a household or small- scale on-site treatment system for each cluster, with adequate land available for soil absorption or transpiration as identified in the first paragraph of this paper.

Having provided a background to the technology-practice of sewerage in Indigenous communities of Australia, this paper will now review the experience to date with evapotranspiration for wastewater disposal or reuse.

Figure 1: A typical remote indigenous community in the north of Western Australia (Photograph by Martin Anda)

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3 CURRENT REGULATION

The Western Australian State Health Act provides regulations for the design and installation of on-site systems including evapotranspiration (ET). However, its requirements are prescriptive and do not allow for site-specific design.

The Australian Standard for on-site effluent disposal AS1547-1994 (Standards Australia, 1994) provides a procedure for sizing evapotranspiration (ET) and evapotranspiration- absorption (ETA) systems. The upgraded standard (A/NZS1547) soon to be published will be more comprehensive in its coverage of such systems with a performance-based approach instead of a prescriptive one. Thus greater diversity and innovation will be possible.

The Aboriginal Housing & Infratructure Unit of the WA Ministry of Housing provides a standard and basic specification for sewerage systems with its housing contracts – for septic systems or common effluent disposal to lagoons. Attached to this, for tenderers, the Ministry provides the National Housing Design Guide (Healthabitat, 1999), which is a set of guidelines based on many years of experience by Healthabitat working with indigenous communities.

The Northern Territory Government is perhaps more advanced than WA with the 1996 Code of Practice on Small On-site Sewage and Sullage Treatment Systems and the Disposal or Reuse of Sewage Effluent. A revised edition of this code is expected to be released this year. Moreover, it has developed a 1998 Environmental Health Standards for Remote Communities. The latter refers to the former for the performance of sewage disposal systems. The WA Health Department has engaged consultants for the preparation of its own set of environmental health standards. These will also need to specify requirements for effluent disposal in Indigenous communities.

In February, 1999 a 12-month trial of domestic greywater recycling came to an end in WA. In the shires of Bassendean, Kalamunda and Kalgoorlie/Boulder householders had been permitted with the use of licensed plumbers to install approved on-site greywater recycling systems. In the latter shire, where clay soils and low rainfall occur, ETA trenches are ideal. No subsidies or other incentives were offered and only 4 systems were installed with a significant opportunity lost to gather information on the performance of new and innovative systems. Nevertheless, the Water and Rivers

18 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS

Commission prepared a policy statement and guidelines for greywater recycling with the support of the Minister who was to table this in Parliament for legislative amendment to the State Health Act. It was widely known that in the order of 20% of householders recycle greywater without permission. This trend will no doubt continue, particularly in rural areas. Once greywater recycling is approved the next logical step is to conduct trials of dry composting toilets in residential areas with typical lot sizes that one would find in urban areas.

4 SYSTEM CHARACTERISTICS

ETA systems can be used in those areas where soil is high in silts and clays, rainfall is low, and pan evaporation is high. These systems cost considerably less and require less maintenance than reticulated systems with lagoons (McGrath et al, 1991). As with conventional leach drains some form of primary treatment is necessary ahead of the system – two septic tanks with total wastewater, a greasetrap for kitchen effluent, and a sullage (single small septic) tank is normally required for greywater.

Evapotranspiration (ET) systems are those which include a lining in permeable soils or in the case of highly impermeable soils infiltration is so low that it is not significant in relation to evaporation and transpiration. Effluent is distributed in a bottom layer of gravel and, when the effluent fills this layer, an upper layer of coarse sand wicks the effluent to the surface where it evaporates. Plants in the sand layer transpire effluent. McGrath et al. (1991) documented the relative contributions of these effects to disposal assuming no soil infiltration.

Evaptranspiration-absorption (ETA) systems are used in soils of low permeability, where there is no risk of groundwater contamination, and where the effect of transpiration by surrounding deeper rooted perennials can contribute to effluent disposal. Percolation into the soil and transpiration from plants directly on the trench also contribute to effluent removal as in the ET systems. In other words, wastewater reuse for plant growth can be a major objective in addition to disposal.

Variations of the water balance method were used for sizing ET and ETA systems by McGrath et al. (1991), Australian Standards (1994) and Otis (undated). Further work is necessary with the method to provide more detail on the effects of transpiration.

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5 ECOLOGICAL DESIGN

“Ecological design” seeks to reconcile the cultural activities and natural ecologies on a site to sustain each of their needs in an integrated fashion.

Many concerns have been raised in relation to implementation of wastewater reuse without proper management or maintenance: public health risks, groundwater contamination, mosquito breeding, flooding during winter rainfall, sludge build-up and blockages. However, there is another issue for concern that may lead to some of these problems and others indirectly: poor design (or no design). This includes not just the design of the system itself, but the manner by which the system is integrated into the landscape. Australian standards such as AS 1547 do, for example, specify minimum setbacks from houses and lot boundaries, provide ways of avoiding inundation and give design criteria for terraced disposal fields on slopes. There are very few practical design methodologies that may enable the most appropriate placement of a wastewater reuse system in the house yard or community landscape. Two examples are: * hydroscaping(Colwill, 1996) for water-sensitive garden aesthetic design; and * permaculture (Mollison, 1988) for sustainable food production design.

Hydrozoning will allow the placement of the wastewater reuse system in accordance with a garden layout designed for aesthetics and plant groupings of similar water needs.

Permaculture draws on a wider range of design tools including zoning for energy efficiency and sector analysis of the natural influences on the site (sun, wind, slope, fire, view). Zones 1 to 5 in permaculture refer to areas of planting types (intensive salad beds, low maintenance orchards, through to natural bushland) placed in relation to house or settlement according to frequency of visits. Design with sectors allows the appropriate placement of windbreaks, shadetrees, water tanks, zones and other elements in the landscape. This is particularly useful in the design of indigenous settlements, given that a large proportion of people’s lives (including cooking, relaxing, sleeping) is spent in the yard around the house rather than in it. Often of particular concern to the occupants is the need to view adjacent houses or the community entrance for coming and goings and certain directions into the surrounding country where there may be sites of significance. Such considerations affect the placement of the aforementioned elements.

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The use of a design approach prior to installation enables placement of the wastewater reuse system in a landscape with respect to the vegetation type that it will support, its position in relation to other elements and natural influences on the site, and the cultural needs of the house occupants. If such considerations are ignored with a focus merely on the technical design of the system itself then improper management and maintenance and poor performance may still be the longer term outcome.

5 CASE STUDIES

The ET or ETA systems known to have been installed in WA Indigenous communities are listed in Table 1. These have either been installed with RADG involvement or by the use of RADG design criteria.

The first RADG ETA trenches were installed in conjunction with 4 RADG-designed ablutions facilities (known as the Remote Area Hygiene Facility –RAHF) for Indigenous town camps on the fringes of Kalgoorlie in 1990. Not knowing the exact number of persons that would use the facilities they were oversized at approximately 12 m long x 2000 mm wide x 1000 mm deep in rocky clay soil. The RAHF comprised pour-flush toilet directly over septic tank, laundry and shower. Thus largely greywater discharged into the trench. No ponding was observed over the 5 years for which they were monitored. Native seedlings failed to establish on the trenches due to insufficient moisture in the first summer and with no supplementary irrigation provided.

Later the same year an ETA system was designed for the Kawarre Indigenous community in the Purnululu area of the East Kimberley region. The system was installed in black soil at 20 m long x 1200 mm wide x 900 mm deep to receive greywater direct from two ablutions blocks with shower and laundry (dry pit toilets were used). No ponding was observed in its first 2 years of operation after which the facilities were no longer used (Mike Ipkendanz Architect, pers. comm., 1999).

ETA trenches were installed in loam soil after 2 septic tanks for all the wastewater from 2 houses in Irrungadji Indigenous community at Nullagine in the East Pilbara region in 1991. Each trench had been designed for 15 people with an area of 45 square metres and a depth of 1000 mm but on-site installation reduced the size to that normally used for conventional leach drains: 22 m long x 1300 mm wide x 1000 mm deep (McGrath,

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1991). The vegetation planted on and around the trench failed to establish due to lack of protection from children playing. After many visits no cases of ponding were ever observed.

An ETA trench was installed in rocky clay soil in the Mardiwah Loop Indigenous town camp at Halls Creek in the East Kimberley region in 1991 after a RAHF with pour flush toilet. The same design as Kalgoorlie was used except depth was reduced so that overall dimensions were 12 m long x 2000 mm wide x 800 mm deep. This facility was used by up to 40 people each day. Over the next 2 years 8 more ablutions facilities (3 pour-flush and 5 standard dual-flush with 2 septic tanks) were installed, each with similar sized ETA trenches. Each of these facilities was used by 10-20 people. Vegetation self-seeded on all trenches and in some cases seedlings planted directly on the trenches established as shrubs. On numerous visits over subsequent years only one case of major ponding was observed. This was on a heavily used pour-flush RAHF with a 200-litre soakwell in the ETA trench which assisted to distribute effluent in the early designs. The soakwell had become full of sludge after 2-3 years, indicating the facility was overloaded but also that dual septic tanks may have been more appropriate.

Figure 2: RADG evapotranspiration-absorption trench installed at Mardiwah Loop (Photograph by Martin Anda)

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An ETA system was installed on the Education Department school at Parnngurr (Cotton Creek) Indigenous community in the Rudall River region of the Western Desert in 1992. No details are available other than the soil is a clay loam.

An ETA system was installed on a new 3-bedroom house at Parnngurr in 1994. The septic tank design was of the old style rectangular 2-compartment constructed in-situ. The ETA trench was approx. 12 m long x 3 m wide with depth unknown. No plantings had been implemented.

At Pia Wadjari community in the Midwest region several houses had been constructed with septic tank ETA systems. One had become blocked and overflowed as a result of not pumping out the sludge from the tanks. In 1996 an ablutions facility discharged laundry effluent directly onto the ground. Several makeshift kitchens attached to houses also discharged effluent directly to the ground. Shallow ETA trenches were installed into the sandy clay soil for these to provide an interim solution to this severe public health problem. Dimensions of each were approx. 6 m long x 500 mm wide x 300 mm deep.

At Wurrenranginy Indigenous Community (Frog Hollow) in the East Kimberley in 1996 two houses (each with 4 occupants) with a common kitchen, washing machine, and hand basin, discharged directly into an ETA trench of dimensions 15 m long x 1200 mm x 800 mm deep. The showers discharged directly onto garden beds where plants such as papaya were grown. The school kitchen for about 35 children with a sink and hand basin discharged into a grease trap and then the same ETA. Native grasses had established on the surface (Mike Ipkendanz Architect, pers. comm., 1999).

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Table 1: Summary of ET Systems installed in WA Indigenous Communities Year of Annual Pan Evap. Soil type # installed @ Influent installation & Rainfall (mm) Length (m) x community (mm) width (mm) x depth (mm). 1990 Ninga Mia 260 2600 Rocky 4 @ Laundry, clay 12x2000x1000 shower, pour- flush toilet 1990 Kawarre 680 3000 Black soil 1 @ 20x1200x900 Ablutions block

1991 Irrungadji 330 n.a. Clay loam 4 @ All domestic 22x1300x1000 wastewater 1991-93 530 3200 Rocky 9 @ 12x2000x800 Ablutions blocks Mardiwah Loop clay 1992 Parngurr 310 n.a. Clay loam n.a. n.a. school (Telfer) 1994 Parngurr 310 Clay loam 1 @ 12x3000x? All domestic house (Telfer) wastewater 1996 Pia Wadjari 210 3000 Sandy 1 @ 6x500x300 Kitchen (Gasc clay 1 @ 6x500x300 Laundry Jnctn) 1996 680 3000 Rocky 1 @ 15x1200x800 2 houses Wurrenranginy clay ablutions + school canteen 1997 190 2400 Sandy 11 @ 6x600x600 4x laundry, 4x Tjuntjuntjarra (Rawlinna clay loam shower, 1x ) kitchen, 2x house 1998 Jigalong 270 n.a. Sandy 5 @ 12 x 2000 - Greywater only (Mundiwin clay loam 300 x 600 di) 1998 Irrungadji 330 n.a. Clay loam 4 @ 16 x 2000 - All domestic 300 x 600 wastewater 1999 Tjalku Wara n.a. 1 @ 22 x 380 x Greywater 1100 1999 Wongatha 234 3500 Silty sand 5 @ 22 x 380 x Greywater Wonganarra 1100

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In 1997, at Tjuntjuntjarra Indigenous community in the Great Victoria Desert, 4 ablutions facilities had been discharging effluent from washing machines and showers directly to the surrounding ground for about 18 months due to the contractor having left without constructing the specified effluent disposal system for each facility. Each facility comprised a laundry, a shower and a Clivus Multrum dry composting toilet and was used by 10-20 people typically. The vault of the latter was installed below ground level in an excavated pit open for maintenance access. In 2 of the facilities effluent had flowed into the pit and filled the vault thus rendering the dry composting process dysfunctional. A number of dwellings (Atco site huts) were discharging greywater directly onto the ground also. With limited time and resources available each of the ablutions facilities was fitted with 2 ETA trenches and each dwelling with a single ETA trench all with dimensions 6 m long x 600 mm wide x 600 mm deep. The latter ETA trenches were each preceded with a standard greasetrap.

Each ETA trench was planted with a mix of native shrubs and fruit trees, most of which established successfully and flourished. The success rate of this remedial action at Tjuntjuntjarra was high but only on the low water use households – elderly and singles quarters (Katie Angel, pers. comm. 1999). Family households typically had sick babies and required high water use with these systems ponding. The standard greasetraps were too small to effectively remove solids and grease.

At Jigalong Indigenous community in the Western Desert 5 ETA trenches were installed in sandy loam soil (approx. 300 mm depth) over clay for new housing in 1998, using a modified design (by Halin Orion, Arid Tropical Permaculture, Wittenoom) with dimensions 12 m long x 2000 mm wide (at surface, 300 mm at base) x 600 mm deep. Only greywater was discharged to the ETA trenches but the East Pilbara Shire EHO demanded that the contractor install 2 septic tanks and a chlorine dosing system. The blackwater went to the sewer after a single septic tank. The greywater plumbing side was designed to overflow to sewer. The ETA trenches were placed by the following criteria: · On the east (morning sun) side of the house for the benefit of associated fruit trees; · 2 metres min. from house to allow planting of sensitive annuals in this microclimate, use as a walkway, or so as to be close enough for fruit tree care and harvest; · 2 metres min. from yard fence to allow establishment of windbreaks for protection of hot summer winds;

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· carefully integrated with water harvesting swales and basins as part of the yard landscaping design. The L-shape of the ETA trenches allowed growth of trees around the SW corner of the house and the placement was ideal for growth of sensitive fruit trees, themselves within an outer windbreak of hardy native shrubs. Moreover once vegetation is established the hot easterly winds will be cooled by this microclimate before they strike or enter the house.

At Irrungadji again 4 ETA trenches were installed in 1998 on new houses the modified profile and dimensions 16 m long x 2000 mm wide (at surface, 300 mm at base) x 600 mm deep. All household wastewater discharged into 2 septic tanks before entering the ETA trench. Again the design process followed principles outlined above and no information is available on performance.

6 FIELD MEASUREMENTS

To date only data from Jigalong could be gathered for Table 2 on the hydraulic performance of ETA systems.

Evapotranspiration- Soil Permeability Design Loading Rate Hydraulic depth

absorption trench Ksat (m/day) (mm/day) (mm) Jigalong 1998 #1 0.22 8 0 (Lane house) Jigalong 1998 #2 0.22 8 100 (Jeffries house)

Table 2: Summary of Data Gathered from Selected ETA Trenches

The original application to the Health Department of Western Australia on 7/8/98 for these ETA trenches included AS 1547-1994 design calculations based on advice that the soil condition at the specific sites was probably about 300 mm of sandy loam over mainly clay. A clay loam was thus chosen as an average for the design calculation. Ideally, an observation pit of depth 1200 mm should have been dug to ascertain the soil profile details, including structure, in each yard. The design process resulted in selecting an ET trench of 12 m length.

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Lysimeters had been installed on the ET trenches at the 2 houses. On 29/7/99 an associate had observed about 100 mm of effluent in the bottom of the trenches. The ET trenches had been excavated about 200 mm deeper by the contractor than the recommended 600 mm. On 17/11/99 no effluent was observed in the #2 trench lysimeter.

Draft AS/NZS On-site Domestic Wastewater Management (Nov 98 draft) adopts a new approach for soil evaluation and wastewater system design which will supersede AS 1547-1994. This method is applied as follows.

Permeameter measurements had been made by asn associate on 29/7/99 on #1 ETA. On 17/11/99 the same test was conducted on the #2 ETA next door as it had been reported that this yard seemed to have a higher clay content. A bolus test here formed a ribbon of 25-40 mm indicating a sandy clay loam.

In both cases 1-minute intervals between readings were used. The auger diameter was 75 mm resulting in a hole diameter of 90 mm. The main tube internal diameter was 31 mm and the internal tube external diameter was 10 mm giving a permeameter internal volume of 6.76 cm3/cm. Holes were augered to a depth of approx. 500 mm in both cases and the depth of water was approx. 300 mm.

The above results indicate that the 1-minute interval chosen was too short because the differences keep alternating between a high and low figure instead of stabilising, i.e. a bubble was rising each time just before or just after a reading. However, it can be seen that for both yards the average stable level difference was 5 cm. Assuming there was no impervious layer near the bottom of the hole the general equation from AS/NZS is: -1 2 Ksat = 1.6Q{sinh (H/r) – 1}/(2pH ) i.e. Q = 5 x 6.76 = 33.8 cm3/min -1 2 Ksat = 1.6 x 33.8 x {sinh (30/4.5) – 1}/(2p30 ) = 1.6 x 33.8 x {1.60/5655} = 0.0153 cm/min OR 22 cm/day OR 2.55 x 10-6 m/s OR 0.22 m/day

The soil category is thus 4, moderate to slow drainage, weakly structured, clay loam. Given the effluent is only greywater then passing through 2 septic tanks it is reasonable to say it is “improved septic tank effluent”. For the above Ksat of 0.22 the design loading rate (DLR) is 8 mm/day. It is acknowledged in the standard that the given DLRs are

27 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS conservative and the flexibility is given to provide for a reduced rate if a reasonable case is presented.

For household greywater effluent only the flow rate allowance is 120 litres/person.day. If 4 persons are assumed, as was the case for #1 house, this represents 480 l/day. However, for the new houses at Jigalong the laundry and external shower effluent is directed to the sewer and not the ET trench so this could be a high figure being the internal bathroom and kitchen effluent only. The surface of the ET trench is 2 m wide so therefore the required length L is: L = 0.48/0.008 x 2 = 30 m

This is substantially more than the 12 m installed but overflow to sewer is provided. Moreover, a key design objective is to facilitate the growth of plants in a fenced area.

7. CONCLUSIONS

On-site wastewater reuse by means of evaptranspiration-absorption can yield both public health and sustainability benefits in remote Indigenous communities. The tendency however is towards reticulated sewers pumping to oxidation ponds. While these are reliable, perform well and are relatively low maintenance there is still a costly requirement for visiting technicians to maintain the sewers and pump stations. If managed correctly, wastewater reuse in remote Indigenous communities can not only result in water savings but also improved public health through dust suppression from revegetation, improved nutrition from locally grown food, and fewer system failures from decreased loading on treatment systems.

The results of 10 years research and development by RADG on ET systems shows that they have not failed in any way similar to the rate that standard leach drains were failing at the time the work started. Observations to date indicate that design by use of WA Health Act regulations and AS1547-1994 results in oversizing and death of plants, particularly when combined with the fact that houses can be empty for several months each year for cultural reasons over the hot summer months. The recent investigations into the ET systems at Tjuntjuntjarra have shown that house overcrowding combined with an over-reduction in size (50% of standard) results in ponding which is unacceptable for public health even though plantings thrived.

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The shallow modified ETA system with greater length dependent on house size is beneficial for plant growth and to ensure plant survival during periods of reduced influent sensitive species should be placed at the beginning with hardier species at the end. Further trials are necessary to monitor this arrangement. Overall further research is necessary on these systems across WA to evaluate hydraulic performance, to determine plant transpiration contributions to disposal for specific designs, and to define clearer design guidelines for future implementation.

8. REFERENCES

John Colwill (1996), The Waterwise Garden and How to Create One, Water Authority of WA, Perth. Environmental Health Needs Coordination Committee (1998), Environmental Health Needs of Aboriginal Communities in Western Australia: The 1997 Survey and its Findings, Homeswest, ATSIC, AAD, Health & Family Services, WAMA, HDWA, Perth. Ted Gardner, Phillip Geary & Ian Gordon (1997), Ecological Sustainability and On-Site Effluent Treatment Systems, Aust J Env Management, Vol 4, September, pp144- 156. Healthabitat (1999), The National Indigenous Housing Design Guide: improving the living environment for safety, health and sustainability, Commonwealth, State and Territory Ministers’ Working Group on Indigenous Housing/Commonwealth Department of Family and Community Services. Glen Marshal & Bob Lloyd (ed) (1998), Sewage Systems in Remote Indigenous Communities, CAT Report #98/8, Centre for Appropriate Technology, Alice Springs. McGrath D, Ho G & Mathew K (1990), On-site Wastewater Disposal in Clay Soils - The Use of Evapotranspiration Systems and Conventional Methods, in Mansell, Stewart & Walker (eds), Proceedings of the UNESCO Regional Seminar on Technology for Community Development in Australia, South-East Asia and the Pacific, Alice Springs, 9-11 July, Development Technologies Unit, University of Melbourne/Centre for Appropriate Technology. McGrath D, Ho G & Mathew K (1991), The Effectiveness of Evapotranspiration Systems in Disposing of Wastewater in Remote Aboriginal Communities, Water Science and Technology, 23, 1825-1833, IAWPRC, London.

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McGrath D R (1991), Installation of Evapotranspiration Systems at Irrungadgi Community, Nullagine, in Ho G (ed), Seminar on Appropriate Technology for Remote Communities, Newman, RADG, Murdoch University. Bill Mollison (1988), Permaculture: A designer's manual, Tagari Publications, Tyalgum. Mark Moran (1999), Improved Settlement Planning and Environmental Health in Remote Aboriginal Communities, #cat 99/6, Centre for Appropriate Technology, Alice Springs. Petronella Morel and Helen Ross (1993), Housing Assessment for Bush Communities, Tangentyere Council, Alice Springs. Otis Richard (undated – 1980?), On-site Wastewater Disposal: Evapotranspiration and Evapotranspiration/Absorption Systems, Rural Systems Engineering, Madison, Wisconsin. Territory Health Services (1996), Code of Practice for Small On-Site Sewage and Sullage Treatment Systems and the Disposal or Reuse of Sullage Effluent, Northern Territory Government, Darwin. Territory Health Services (1998), Environmental Health Standards for Remote Communities in the Northern Territory, Northern Territory Government, Darwin. Standards Australia (1994), Disposal systems for effluent from domestic premises, AS 1547 - 1994, Standards Australia, Homebush, NSW. Standards Australia/Standards NZ (1998). On-site Domestic Wastewater Management, AS/NZS 1547-Draft, Issued: November, Homebush/Well.

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GREYWATER REUSE: METHODS AND DIRECTION FOR

POSSIBLE FUTURE DEVELOPMENTS IN AUSTRALIA.

M. ANDA, K. MATHEW & G. HO

ABSTRACT

Wastewater is often considered to be a source of public health problem and to be disposed of rather than considered as a resource. The choice of treatment system is usually governed by disposal strategy rather than reuse options. Domestic sewage generally consists of wastewater produced from the toilet, kitchen sink, bath, shower, washbasin and laundry. Toilet waste, which makes up 25 to 30 percent of the flow, is referred to as black water, while the rest of the wastewater is referred to as greywater. The blackwater contains the major portion of biochemical oxygen demand, suspended solids, bacteria and nutrients. So if the black water is treated separately then the treatment of greywater alone becomes easier and less complicated. Greywater reuse is widely supported by the community in Australia and promoted by researchers. However regulatory authorities have not given permission for greywater reuse. This paper illustrates a few case studies of greywater reuse trials following treatment of the greywater. The reasons for greywater reuse to be permitted by the regulatory authorities are articulated. In the future greywater reuse should be encouraged, and excess payment may be imposed if the greywater is to be treated by a municipality. This paper discusses the different treatment processes being developed to treat greywater successfully. Development of these methods and successful completion of the trials are necessary to develop public confidence to encourage greywater reuse. Present status of the methods and practices with direction for possible future developments are discussed in the paper.

1. INTRODUCTION

The paradigm governing wastewater management has in the past focussed on the pollutants in the wastewater. A consequence of this is the preoccupation with public health, and with adequate treatment and safe disposal of the treated wastewater. Wastewater is viewed as a problem and is to be disposed, rather than viewed as a resource. The choice of treatment is also generally governed by a disposal strategy than

31 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS by a reuse strategy. Associated with this paradigm has been the use of a centralised approach to water supply, sewerage and stormwater drainage. With this approach up to 85% of costs are incurred in piping and pumping. Recently the appropriateness of this paradigm has been questioned (Newman, 1993; Beder, 1993) when demand for water is increasing, reuse is necessary because of limited freshwater sources in arid and semi-arid regions or when population growth has exceeded available water supply. Question has also been raised about the appropriateness of the transfer of expensive centralised systems to developing countries (Niemczynowicz, 1993). Present practice in developed countries is taking place in parallel with low density urban sprawls with treated wastewater disposed to ocean or rivers. Pollution of the receiving waterbodies by nutrients has resulted in excessive algal bloom (eutrophication) in a number of cases. Reuse options are generally limited as another expensive reticulation system for water reuse is required.

Reuse of wastewater. on the other hand, is facilitated when we have on-site (localised) or small scale treatment systems. Involvement of a local community is facilitated and reuse options in the local context agreed upon. Localised treatment/reuse also provides a wider range of options. Even in sewered areas greywater reuse can be implemented. Greywater is water from the bathroom, washbasin and laundry, and may include kitchen sink wastewater. The more concentrated blackwater (from the toilet) can still go to the sewer. In unsewered areas the blackwater can be treated separately. Because greywater is less concentrated than blackwater its treatment becomes easier and less complicated.

Wastewater treatment usually entails the separation of solids from the water. It is logical therefore to separate the more concentrated blackwater from the greywater prior to treatment. In industrial wastewater treatment it is already common practice to seggregate concentrated wastewater streams from lightly contaminated streams. The concentrated streams (which are usually low in volume) are separately treated. The high volume low concentration streams do not usually require extensive treatment, thus minimising the total cost of treatment compared to treating a combined stream.

Similarly greywater reuse can result in cost savings (to both the consumer and state water authority), reduced sewage flows in sewered areas and potable water savings of up to 38% when combined with sensible garden design. To have a significant impact on water and energy use greywater reuse needs to be coincidental with water-sensitive

32 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS design, reduced lawn areas and if desired growing food at home and in public open space. The Wastewater 2040 community consultation process carried out by the Water Authority of Western Australia with the Commonwealth Scientific and Industrial Research Organisation (CSIRO) showed that there was immense community support for reuse of wastewaters (Water Authority of Western Australia, 1994).

Designs for greywater reuse need to be developed that do not cause environmental contamination or present a public health hazard. The purpose of this paper is to briefly review current research and development in Australia and elsewhere that is leading to acceptable designs while focussing on five methods being studied and promoted by the Institute for Environmental Science at Murdoch University. Some trials are occurring both at the Institute's 1.7-hectare Environmental Technology Centre (a fully integrated permaculture development) and at various sites in Western Australia. A scenario for the future is sketeched where greywater reuse is not only permitted but promoted and gains wide community acceptance. Payment for discharging greywater into the sewer may be levied where reuse options are available.

2. CURRENT REGULATION

Domestic greywater reuse, governed by state and local government health acts, is currently not allowed in any of the Australian states although it is acknowledged by the state authorities that 20% of householders engage in this practice in Perth (Lugg, 1994; Stone, 1996). Treated effluent from centralised plants of some country towns located in arid areas is used on municipal ovals and golf courses. More recently, in the state of New South Wales, treated effluent from centralised plants has been allowed in urban areas (New South Wales Recycled Water Coordination Committee, 1993).

In Queensland three options have been developed for possible implementation (Department of Primary Industries, 1996). These were 1) allowing greywater reuse to be continued in unsewered areas with additional monitoring by Local Government; 2) permitting and encouraging greywater reuse in both sewered and unsewered areas; and 3) extend option 1 to incorporate active promotion of reclaimed water (treated wastewater) through dual reticulation. This was a policy options paper and no technological options were discussed, e.g. how to provide for pollution control.

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National guidelines for the use of reclaimed water via dual reticulation have been prepared (National Health & Medical Research Council, 1996). Of relevance are the criteria recommended for non-potable uses in urban residential areas, i.e. garden watering, toilet flushing and car washing, agricultural food production, and aquaculture food production. The level of treatment recommended is secondary plus filtration and pathogen reduction. The filtration is required to further reduce suspended matter thereby making pathogen reduction via chlorination more effective. Pathogen reduction by disinfection (e.g. chlorination) or detention (e.g. lagoons) is required. It is possible that artificial wetlands can achieve all of the foregoing as a tertiary treatment method particularly if there are open water areas which will allow pathogenic die-off due to UV sterilisation.

Model guidelines for domestic greywater reuse in Australia have also been prepared (Jeppeson, 1996). These covered hand basin toilets, primary greywater systems (direct subsurface application) and secondary greywater systems (mesh, membrane or sand filtration prior to irrigation). Procedures, criteria, components and irrigation area layout designs are provided for the design of individual systems. For primary systems the guidelines have adopted the Californian approach requiring the use of a surge tank with a screen to remove lint and hair. Electrical power is therefore required for the automatic pump system and weekly inspection and clearing of the screen. The need for maintenance to these components by the householder resulted in some 80% of Californian systems being in an unsatisfactory condition. The applicaton of this approach as the solution for Australia may need to be questioned. Secondary systems should be installed by licence only as is currently the case for all on-site disposal systems in Western Australia including aerobic treatment units. As with the latter, in Western Australia, the owner is required to enter into a maintenance contract with the supplier.

3. SYSTEM CHARACTERISTICS

A greywater reuse system needs to be able to receive the effluent from one or more households all year round. Where saturation of garden soils of low permeability occurs in winter rainfall, there should be facility to divert to sewer or alternative disposal. The system needs to protect public health, protect the environment, meet community aspirations and be cost-effective (Murphy, 1996).

34 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS

Current on-site treatment systems have generally adopted the technology of the conventional activated sludge plant for large treatment systems. This is understandable, because the effluent standard for garden surface irrigation is a chlorinated effluent containing not more than 20 mg/l BOD and 30 mg/l SS. Differences that can be observed are the insertion of a trickling filter in the aeration chamber to cope with variable flows, and the infrequent removal of sludge. Anaerobic decomposition takes place in the first settling chamber where sludge is returned and stored.

If removal of nutrients is required for installation of on-site units in nutrient-sensitive catchments, phosphorus (P) can be removed by alum dosing and nitrogen (N) by nitrification and denitrification in separate chambers or by intermittent aeration of a modified activated sludge set-up. Hyperchlorination of ammonium in secondary effluent theoretically removes N by oxidation to nitrogen gas.

Five different methods of greywater treatment and reuse are being evaluated by the Institute for Environmental Science at Murdoch University. They are described below after a brief review of international and Australian experience. Each system can be on- site for individual households or can be scaled up for cluster housing. Each has some capacity for pollution control while being cost-effective.

4. INTERNATIONAL AND AUSTRALIAN EXPERIENCE

Use of greywater systems in Japan and the United States have been reviewed for their applicability to Australian conditions (Jeppeson & Solley, 1994). The most progressive application of domestic greywater reuse appears to be in California. But even here the minimum prescribed depth of 430 mm for subsurface irrigation "ignore(s) the importance of aerobic bacteria and biota (found in profusion in the top few inches of

35 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS garden soil) for digesting organic matter, nutrients and possible pathogens found in graywater" (Kourik, 1995).

In Japan reuse of wastewater from centralised or high-rise, on-site treatment plants is common due to shortages of potable water. The secondary treated effluent is used in toilet flushing, ornamental ponds, parks and gardens. In single-family dwellings hand- basin toilets and reuse of bathwater for clothes washing occurs. Administration of on- site reuse is the responsibility of the building owner and the government sets effluent guidelines.

After reviewing the international experience Jeppeson & Solley (1994) recommended that greywater reuse systems be administered under the following formats in Australia: • Primary greywater systems which involve no or primary treatment prior to use. They typically comprise a surge tank with pump, a sullage tank or direct gravity feed to subsurface irrigation. They can be owner built but need to be connected to the house by a licensed plumber and a local authority permit is required; • Hand basin toilets where a basin for hand-washing (preferably without soap) is integral to the cistern. They can become a commercial product approved by each individual state; • Secondary greywater systems which involve aerobic and/or anaerobic treatment to achieve a secondary effluent. They typically comprise a surge tank, treatment process and surface or subsurface irrigation field often with an amended soil for nutrient retention. They would have the same requirements as aerobic treatment units which include licensing with the state authority and installation and maintenance by the supplier. They calculated that the payback period for the simplest greywater system, in relation to cost of water supply, is 10 years but owners perceived environmental benefits and a fertiliser resource.

Greywater reuse projects which have been trialled in Australia are briefly reviewed below.

Primary greywater system

A project conducted in Melbourne, Australia involved the collaboration of the state government water authority Melbourne Water, the Victorian University of Technology

36 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS and the Department of Health & Community Services (Christova-Boal et al., 1996; Lechte et al., 1995). There were four experimental sites. The various laundry and bathroom effluents were segragated into separate streams to determine the effects on subsequent reuse in toilet flushing and subsurface garden irrigation. The systems comprised strainer at discharge from each fitting, collection tank, mesh filter, storage tank, disinfection, pump, and fine filter at entry to irrigation field. Irrigation was by either leachfield or pressure/drip arrangements.

Preliminary results (Lechte et al., 1995) indicated that greywater quality would be highly variable and at times some characteristics resembled weak to medium sewage. It appeared that some constituents may pose a problem for soils and plant growth. Subsurface irrigation systems can be installed for around $A5 - 8 per square metre or $A300 to $A2,000 per home depending on local requirements. There were annual water savings of around 30 kL which at a domestic water charge of $0.65/kL represented a savings of $20 p.a. The irrigation systems designed were far from passive and may result in problems for the lax householder. Surveys showed significant community interest in greywater reuse.

Marshall (1995) conducted research into an on-site system in New South Wales that successfully integrates greywater, excess liquid from a composting toilet, constructed wetland planted with Phragmites australis (common reed), holding pond, flowforms and sub-surface drip irrigation. Long term performance data may still be required.

Secondary greywater system

A project in Canberra involved a total household wastewater trial and a greywater only trial (Neal, 1996). The former involved the installation of six, on-site wastewater treatment plants (of two different types) at individual households to treat all of the wastewater generated. The latter involved segregation of greywater and blackwater so that greywater schemes of the following characteristics could be implemented: low capital cost; low operating cost; simple technology (easily maintained); insignificant sludge management problems; and quality easily improved by household activity (e.g. detergent selection).

Samples were composited from 50 households and evaluated in 5 different test processes which produced a number of findings:

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• Peracitic Acid is a totally biodegradable, effective disinfection agent; • Aeration and trickle filter processes produced better than 20 mg/l BOD and 30 mg/l SS • Odours became evident quickly with storage.

The trials resulted in the following recommendations for a typical configuration: Solids screening filter; Baffled aeration tank with one week storage; Four week storage tank; Disinfection if secondary contact is required. This level of storage and treatment was seen to be necessary to reduce fungal infestation and run-off in Canberra's cold, wet winter months.

5. FIVE OPTIONS CURRENTLY UNDER RESEARCH FOR WESTERN AUSTRALIA

5.1 Amended Soil Filter

Fremantle Inner City Agriculture (FINCA) developed a community garden on the Fremantle City Council's 800 square metre King William Park on Marine Terrace in South Fremantle, Western Australia and is using the greywater from two adjacent houses to irrigate it. This is part of a water-sensitive, permaculture design approach which also involves harvesting rainwater from the two houses' roofs, heavy mulching and appropriate, low water use species selection for growing food in a perennial polyculture. Design and sizing of the system was generally in accordance with Standards Australia (1994) to gain regulatory authority approvals. AS 1547 - 1994 prescribes greywater design criteria of 240 l/bedroom.day and with 5 bedrooms in total for the two houses the system is designed to handle 1,200 l/day. In 1985 a Metropolitan Water Authority study showed the average greywater output for a Perth household to be 288 l/day. A preliminary flow measurement at King William Park indicated total flow into the system was 360 l/day (180 l/house.day), however, this will need to be substantiated over a longer period.

Laundry and bathroom effluent from the two houses enters a collection tank in the park by gravity. The Health Department of Western Australia required the inclusion of this sullage tank prior to distribution. This was to prevent build-up of suspended solids or biological growths in the distribution system. However, after 12 months tank pump- out revealed there was only some 20 mm of sludge in the bottom. The large diameter of

38 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS the irrigation piping (90 mm) and oulet holes (25 mm) draining into an aggregate surround may avoid build-up anyway. This is particularly the case with the irrigation close to the surface where there is aerobic, biological activity and the presence of earthworms is promoted. From the tank the effluent can be sent to either a duty or duty/standby field by gravity.

The duty field is modelled on the 'Ecomax' principle (Bowman, 1996) and its aim is to result in a tertiary quality effluent entering groundwater so as to avoid contamination by nutrients or pathogens. The plastic lined trench is filled with a mix of 85% red sand and 15% red mud (with 5% gypsum in the latter to neutralise its alkalinity). The red mud and sand are by-products of bauxite refining to alumina. P is adsorbed into this clay material and N is removed from the system by intermittent drying and wetting causing nitirification-denitrification. Pathogens are filtered and die off. The duty field comprises two laterals of 20 m x 1.2 m and 25 m x 1.2 m wide providing some 70 square metres. The field is heavily vegetated causing significant nutrient uptake and transpiration. Thick mulch prevents any human or vegetative contact with greywater.

The duty/standby field involves discharge of greywater into a heavily mulched and vegetated basin. It is expected that a considerable humus layer will form which will act as an aerobic buffer against nutrients and pathogens. The 40 m of HDPE, 90 mm diameter, perforated, flexible drainage pipe provided an irrigation area of 60 square metres.

Investigations in September, 1996 were unable to extract an effluent sample from the red mud filters which is not surprising for a system designed for 1,200 l/day (not including transpiration) but receiving only 360 l/day. Consequently, samples of the red mud were measured for P and N content. P (as PO43- ) in greywater can range from 0 -

35 mg/l and N (as NO3- and NH4+ ) from 0 - 25 mg/l depending on the source and detergents used (Jeppeson, 1996). Kayaalp et al. (1988) found that for P at these levels red mud was able to sorp around 1,000 mg/kg. Red mud samples from different points in the system indicated P at 100 - 600 mg/kg. The system is thus operating at well below saturation point and with heavy vegetation P uptake will continue. Effluent monitoring will be necessary in future to determine N removal.

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Ross Mars has had an absorption trench design based on AS 1547 (Standards Australia, 1994) approved for his property in the Perth suburb of Hovea. This design in effect relies on evapotranspiration. Discharge is into parallel pipes in a sand bed on the local clay substrate. It is assumed that nutrients will be sorped in the clay substrate as well as being taken up by the growth of banana, canna lillies, vetiver grass, sugar cane and other plants. The system performance is currently being monitored.

At Geraldton the Water Corporation of Western Australia is monitoring a single household, subsurface greywater irrigation system with screening and primary sedimentation (Fimmel, 1995). A collection pit and pump were installed to provide effluent to four distribution tanks each of which subsurface irrigate approximately 150 square metres of garden area. Effluent enters the soil, rather innovatively, through the top of 30 inverted plastic funnels in each of the four fields with their 150 mm diameter inlets facing down. A new hand-basin was installed above the toilet cistern in the house for reuse of its effluent. The total cost of the retrofit installation was in the order of $10,000. Results have not been reported yet.

5.2 Sand Filtration

The Envirotech system consists of a receival tank where settling of solids occurs, a second chamber into which the effluent flows and when this is full effluent is pumped to the top of a deep bed sand filter. Effluent is collected in the bottom and flows back to a third chamber of the tank, from where the treated effluent is pumped to the irrigation field. General practice is to chlorinate in this final chamber, although it may not be necessary for subsurface irrigation. A system based on the Envirotech sand filtration for greywater reuse is now designed and awaiting installation at a residence with Health Department approval.

5.3 Wet Composting

The Dowmus vermicomposting toilet system can be upgraded to receive wastewaters - both blackwater and greywater - and trials are currently underway (Cameron, 1994). In Canberra, ACT, for example, about 12 households have had trial systems installed for monitoring by Australian Capital Territory Electricity and Water (ACTEW) (Anon, 1996). With current population growth and water consumption patterns a new dam

40 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS will be required and would cost in the order of $1 billion. ACTEW have chosen to investigate the alternative, innovative path of water conservation measures.

The system utilises the Dowmus tanks modified for wet operation. Blackwater from the toilet enters a wet composting Dowmus tank and from there effluent goes to a second tank where greywater is also received. In this tank effluents are aerated around submerged volcanic rock media to achieve secondary standard treated effluent. From there the effluent goes to an irrigation storage tank in which chlorination occurs. The final effluent is mixed with rainwater to achieve further dilution and to improve the quality of water.

A wet composting research project will be established in Perth relevant to local conditions and integrated into a permaculture design.

5.4 Constructed Wetlands

Tubemakers Water Treatment have recently completed construction of a combined wastewater treatment plant and constructed wetland at Mundaring, Western Australia for the Water Corporation. Mundaring has been served by septic tank systems but is in a water catchment area. A system was deemed necessary that would avoid possible contamination and at the same time allow for safe reuse of the treated wastewater. The hybrid intermittently decanted extended aeration (IDEA) system consists of two aerated tanks in series (Turner et al, 1996). Removal of N occurs by nitirification/denitrification through control of anoxic/aerobic conditions in the first demand aeration tank and in the second intermittently aerated tank. Chemical dosing with alum allows precipitation of phosphates. Ultraviolet sterilisation provides pathogen reduction. Sludge is periodically removed to drying beds.

The free water surface wetland had to be designed within the constraints of the tender specifications and the site. The selection of plant species was based on their local occurrence in the region and proven performance in wastewater wetlands. Emergent macrophyte zones comprised Schoenoplectus validus and Baumea rubiginosa and the submergent macrophyte zones comprised Triglochlin procera and Potamogeton pectinatus. The dual planting design fostered aeration in the wetland and optimal nutrient uptake across seasonal variations.

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The required effluent characteristics (in mg/l) from the wetland are BOD 5, SS 5, total N 10, total P 1 and thermotolerant coliforms 15/ 100 ml. This is a very stringent specification and Tubemakers are confident of achieving this from a monitoring program that in future will cover seasonal variations and increasing load. Effluent from the wetland will eventually be reused on parks and gardens in Mundaring if the Council funds the pipework connection. Currently, and in future in periods of low demand, effluent is discharged to a 4 kilometre evapotranspiration trench.

Not far from the Mundaring site in Hovea, permaculture educator Ross Mars is conducting experimentation on constructed wetlands for his PhD research with the Institute for Environmental Science. The focus of the research is on the performance of the submergent wetland plant Triglochlin hueglii compared against emergent Schoenoplectus validus. Ross' aim is not only to verify wastewater treatment capability but, in line with permaculture principles, to use these 'bush tucker' species in a polyculture arrangement.

5.5 Modified aerobic treatment unit

At the sewered suburb of Palmyra, Western Australia six aged-person, state housing units were chosen to be used for greywater reuse trial out of a larger urban residential redevelopment (Bingley, 1996). The project is an initiative funded through the Innovative Water Management component of the Federal Government's Better Cities program and is the second best option chosen from the Sustainable Urban Water Systems Project (Newman & Mouritz, 1996). Blackwater goes direct to sewer. All greywater from the six units goes to a single 'Aquarius' aerobic treatment unit. After treatment the effluent is pumped to storage tanks located in the roof of each unit. The effluent is then gravity fed to toilet cisterns after disinfection, and excess is used for garden irrigation either subsurface into amended soil or through large droplet sprinklers. The system was commissioned in August, 1995 and a monitoring program commenced from startup.

Of all the on-site aerobic treatment systems the Aquarius unit is clever in its engineering design and claims to remove nutrients to below 1 mg/l. Aquarius has five chambers: (1) primary sedimentation; (2) anoxic chamber for denitrification and chemical phosphorus removal; (3) aerobic biological oxidation including nitrification in trickling biofilter and denitrification in submerged filter; (4) secondary clarifier and

42 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS sludge recycle to the anoxic chamber; (5) chlorination and storage for irrigation (Mathew & Ho, 1993). As the unit was treating greywater only the first chamber was eliminated in this application so that biomass could be maximised in the subsequent treatment process.

At Hamersley Street, Cottesloe, Western Australia, also a sewered suburb, a Biomax greywater reuse system was approved by the Water Corporation and Health Department and commissioned by Durrant & Waite Pty Ltd in May 1996. Effluent is irrigated to the front and back yards via 'Dripmaster' subsurface tubing. Monitoring is currently underway to evaluate the performance with the reduced biomass as a result of greywater influent only.

6. CONCLUSIONS

Some general principles can be deduced from current practice and research for both rural and urban situations. Greywater reuse is supported by a large proportion of the community and it is estimated that around 20% of people in Perth engage in the practice without permission.

Greywater needs treatment to bring it to the quality of secondary effluent to enable a variety of reuse possibilities. This can be done on-site with the current technologies. Reuse by subsurface irrigation at 300 mm deep can be successfully practiced with primary greywater effluent but after a sullage tank.

For the urban village, medium density development or group housing a greywater reuse system utilising secondary treatment and disinfection maintained by a supplier may be most appropriate. For on-site reuse at individual houses in the low-density setting a primary greywater reuse system with direct discharge into a large diameter subsurface irrigation system at 300 mm below the surface is most appropriate. Filters, pumps and treatment units should be avoided as experience shows that these may not be adequately maintained by the owner/occupier. Where maintenance support is available and the owner is prepared to support this cost aerobic treatment units are most appropriate.

If nutrient removal is necessary a treatment system such as Aquarius or Ecomax with sufficient vegetation to utlise the nutrient is ideal.

43 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS

Greywater reuse technology may not be viable now in purely economic terms. Its introduction needs to be seen in terms of its contribution to sustainable development and resource conservation. Greywater reuse is possible without compromising public health. It should be seen as a step forward in environmental quality and should be encouraged at all levels.

7. RECOMMENDATIONS

The commencement of research into the above 5 methods of greywater reuse will aim to achieve regulatory approval for on-site systems. Special effort should be directed to gather data on the long term effects of greywater on plants and soils and their nutrient uptake capacity. The regulatory authorities should approve systems which could be constructed with monitoring and inspection by local authorities. A standard code of practice on greywater reuse should be adopted. At present greywater generally refers to all wastewater except blackwater. However, kitchen effluent should be excluded as it carries oils and high BOD which require treatment.

8. REFERENCES

Anon (1996). Small-scale Systems Halve Water Use, Waste Management and Environment, 8, 18 - 20. Beder, S. (1993). Pipelines and Paradigms: The development of sewerage engineering, Australian Civil Engineering Transactions, CE35, ( 1), 79 - 85. Bingley, E. B. (1996). Greywater Reuse Proposal in Relation to the Palmyra Project, Desalination, 106, 371 - 375. Bowman, M. (1996). On-site Tertiary Treatment Using Ecomax Systems, Desalination, 106, 305 - 310 Cameron, D (1994), Compost Filtration: A new approach to on-site resource management, in Mathew K & Ho G (eds), Workshop on Localised Treatment and Recycling of Domestic Wastewater, Remote Area Developments Group, Institute for Environmental Science, Murdoch University, Perth. Christova-Boal, D., Eden, R., McFarlane, S. (1996). An Investigation into Greywater Reuse for Urban Residential Properties, Desalination, 106, 391 - 397. Department of Primary Industries - Rural and Resource Development (1996), Policy Options Paper - The Use of Greywater, Brisbane.

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Fimmel, B. (1995). National Landcare Program, Water Authority of Western Australia, Perth. Jeppeson, B. & Solley, D. (1994). Domestic Greywater Reuse: Overseas practice and its applicability to Australia, Research Report # 73, Urban Water Research Association of Australia, Melbourne. Jeppeson, B. (1996). Model Guidelines for Domestic Greywater Reuse for Australia, Research Report # 107, Urban Water Research Association of Australia, Melbourne. Kayaalp, M., Ho, G. E. Mathew, K. and Newman, P. W. G .(1988). Phosphorus movement through sands modified by red mud. Water, 15, 26-29, 45. Kourik, R. (1995). Graywater for Residential Irrigation, Landscape Architecture, 85 (1), 30- 33. Lechte, P., Shipton, R., Christova-Boal, D. (1995). Installation and Evaluation of Domestic Greywater Reuse Systems in Melbourne, Australian Water and Waste Water Association, 16th Federal Convention, Sydney. Lugg, R. (1994). Health Controls on Wastewater Reuse, in Mathew K & Ho G (eds), Workshop on Localised Treatment and Recycling of Domestic Wastewater, Remote Area Developments Group, Institute for Environmental Science, Murdoch University, Perth. Marshall, G. (1995). On-Site Management of Greywater and Human Wastes: A greywater wetland and composting toilet treatment system, Honours Thesis, Southern Cross University, Lismore. Mathew, K. and Ho, G. E. (1993). Small Scale Treatment Systems, Seminar on "Urban Wastewater: A lost resource or an opportunity?", Australian Institute of Urban Studies, Perth. Murphy, E. (1996). Wastewater Disposal Option in Mundaring: A practical case study, Desalination, 106, 361 - 370 National Health & Medical Research Council (1996). Draft Guidelines for Sewerage Systems - Use of Reclaimed Water, National Water Quality Management Strategy, Melbourne. Neal, J. (1996). Wastewater Reuse Studies and Trials in Canberra, Desalination, 106, 390 - 405. New South Wales Recycled Water Coordination Committee (1993). New South Wales Guidelines for Urban and Residential Use of Reclaimed Water, Public Works Department, Sydney.

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Newman, P. W. G. (1993). Prioritising Urban Water Research, in Urban Water Research Forum, Australian Water & Wastewater Association 15th Federal Convention, Gold Coast, April. Newman, P. W. G. and Mouritz, M. (1996). Principles and Planning Opportunities for Community Scale Systems of Water and Waste Management, Desalination, 106, 339 - 354. Niemczynowicz, J. (1993). Water Management and Ecotechnology - towards 2020, Workshop on Sustainable Urban Water Systems and Ecotechnology, November 18, Institute for Science & Technology Policy/ Remote Area Developments Group, Institute for Environmental Science, Murdoch University, Perth. Standards Australia (1994). Disposal systems for effluent from domestic premises, AS 1547 - 1994, Standards Australia, Homebush, NSW. Stone, R. (1996).Water Efficiency Program for Perth, Desalination, 106, 377 - 390. Turner, N., Heaton, K. & Meney, K. (1996). Use of Innovative Wastewater Treatment Methods and Constructed Wetlands to Allow Reuse of Treated Domestic Wastewater, Workshop on Wetlands for Wastewater Treatment, September 25, Institute for Environmental Science, Murdoch University. Water Authority of Western Australia (1994). Wastewater 2040 Discussion Paper, Water Authority of Western Australia, Perth

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INTEGRATED HOUSEHOLD WASTE MANAGEMENT SYSTEMS USING VERMICULTURE

K. MATHEW, M. ANDA & G. HO

ABSTRACT

Vermicomposting and vermifiltration are natural waste management processes relying on the use of worms to convert organic wastes to stable soil enriching compounds. Both activities of on-site wastewater management and domestic organic waste management can be accommodated through these processes in a sustainable manner. Sustainability can be achieved through the accelerated cycling of nutrients though a closed cycle whereby waste products are put to productive end use. This paper provides an overview of the system characteristics of management systems utilising vermiculture, the associated methods necessary to manage wastewater and the regulatory framework surrounding such activities.

1. INTRODUCTION

This paper provides the background to the management of domestic liquid and solid organic waste in mainstream Australian society, the regulations that need to be observed in the planning and design of waste management systems, the characteristics of vermiculture, and then 3 case studies of on-site waste management systems that utilise vermiculture: vermicomposting toilets, vermifiltration, and sludge stabilisation.

The paradigm governing wastewater management has focussed on the pollutants in the wastewater and disposal as the solution. It relied on centralised water supply, sewerage and drainage systems with up to 85% of costs incurred in piping and pumping. This paradigm was developed on the Thames River in the last century and its appropriateness for the vast dry continent of Australia has been questioned (Newman & Mouritz, 1996) as has the transfer of these expensive centralised systems to developing countries (Niemczynowicz, 1993) and Australian remote indigenous communities (Race Discrimination Commissioner, 1994). Indeed, the arguments for abandonment of this paradigm in favour of one which cycles nutrients and resources for sustainability are perhaps now as evenly matched against the status quo as they were in the last century when the 'water carriage' lobby narrowly defeated the 'dry

47 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS conservancy' lobby (Beder, 1993). The latter lobby then also sought separation at source with reuse of dry and liquid products for agriculture albeit with much less scientific basis than that available today. Goodland and Rockefeller (1996) proposed three general principles to enable the passage of the new sustainable paradigm: a) cease expansion of sewers and commence decommissioning them; b) promote on-site recycling systems that avoid pollution of water resources; and c) charge the true value of water. In Australia today there is little evidence that (a) is underway in urban centres; however (b) is well underway; and there is certainly discussion of (c) in the prevailing climate of economic rationalism. The focus of this paper is on-site recycling systems.

In assessing the ecological sustainability of nutrient and hydraulic loading rates with on-site effluent treatment systems, Gardner et al (1996) explained that for septic tank systems allotment sizes of up to 1 hectare may be required for a single household. However, for transpiration and aerobic treatment systems the area could be considerably less with up to 4,000 square metres being required. Currently, septic tank systems are in use on lot sizes as small as 600 square metres.

Reuse of wastewater occurs most effectively with on-site (localised) or small-scale treatment systems. A major study of Perth's wastewater management made it clear that it was not possible to reuse all the effluent from centralised treatment plants in the sewered suburban sprawl of Perth - there simply was not enough land for nearby broadacre application. Thus to achieve the goal of total reuse the involvement of a local community in the urban situation would have to be enabled and reuse options in the local context agreed upon. In sewered areas greywater reuse can still be implemented on-site. Greywater or sullage is effluent from the bathroom, washbasin and laundry, and for primary systems should exclude kitchen sink wastewater as it carries oils and high BOD. The more concentrated blackwater (from the toilet) can still go to the sewer along with kitchen effluent. In unsewered areas the blackwater can be treated separately or dry vault composting toilet systems can be utilised. Greywater reuse can result in cost savings (to both the consumer and water utility), reduced sewage flows in sewered areas, and potable water savings of more than 40% when combined with sensible garden design. This paper will a) describe vermiculture as a means of on-site sewage treatment; b) review regulatory developments; c) describe case studies of vermicomposting and vermifiltration; d) and explain the broader design approach that needs to be applied with greywater reuse.

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2. CURRENT REGULATION

The Western Australia State Health Act (Part 7 – Disposal of Effluent and Liquid Wastes) provides regulations for the design and installation of on-site systems including evapotranspiration (ET). However, its requirements are prescriptive and do not allow for site-specific design. For example, the following system sizing in Table 1 is provided for on-site effluent disposal:

Table 1: For Combined Systems, Other than Flats or Blocks of Units With More Than 4 Bedrooms

SOIL CLASSIFICATION

SAND LOAMS OR GRAVEL

Number Minimum French, leach or Minimum French, leach or Of infiltrative evaporation drain Soak infiltrative evaporation drain Bedrooms area (m2) (# x length) wells area (m2) (# x length)

2 or less 18.8 2 x 6m 3 28.2 2 x 9m

3 25.4 2 x 8m 4 38.1 2 x 12m

4 or more 27.6 2 x 9m 4 41.5 2 x 13m

The Australian Standard for on-site effluent disposal AS1547-1994 (Standards Australia, 1994) has recently been upgraded to the superior standard AS/NZS1547-2000 "On-site Domestic-Wastewater Management". It is more comprehensive in its coverage of on- site systems with a performance-based approach instead of a prescriptive one. Thus greater diversity and innovation will be possible. The following design criteria is provided:

2.4.1.2 (a) design for 10 person equivalents; 2.4.2.1 (a) daily allowance of 200 L/person for all waste; 2.4.2.1 (b) weekly allowance of 14,000 L for all waste for up to 10 ep; 2.4.2.1 (c) sludge accumulation: all 80 L/person/yr, greywater 40 L/p/yr, blackwater 50 L/person/yr.

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The Urban Water Research Association of Australia published “Model Guidelines for Domestic Greywater Reuse for Australia” (Jeppeson, 1996) and this was associated with an increased public and professional interest in greywater recycling in all states of Australia throughout the 1990s.

In February 1999, a 12-month trial of domestic greywater recycling came to an end in WA. In the shires of Bassendean, Kalamunda and Kalgoorlie/Boulder householders had been permitted, through the use of licensed plumbers, to install approved on-site greywater recycling systems. In the latter shire, where clay soils and low rainfall occur, evapotranspiration-absorption trenches are ideal. No subsidies or other incentives were offered and only 4 systems were installed with a significant opportunity lost to gather information on the performance of new and innovative systems. Nevertheless, the Water and Rivers Commission prepared a policy statement and guidelines for greywater recycling with the support of the Minister who was to table this in Parliament for legislative amendment to the State Health Act. It was widely known that approximately 20% of householders recycle greywater without permission. This trend will no doubt continue, particularly in rural areas. Experience does need to be gained for local conditions but there is a considerable body of literature for the trial shires to draw from. For example, there are McQuire (1995), Kourik (1995) and Ludwig (1994) for general interest while for contractors and do-it-yourself enthusiasts there are Jeppeson (1996) and Ludwig (1995). Once greywater recycling is approved the next logical step is to conduct trials of dry composting toilets in residential areas with typical lot sizes that one would find in urban areas.

Treated effluent from centralised plants is used on municipal ovals, parks and golf courses in many country towns of Western Australia (Mathew & Ho, 1993). In New South Wales (NSW) treated effluent from centralised plants is allowed in urban areas (NSW Recycled Water Coordination Committee, 1993). National guidelines for the use of reclaimed water via dual reticulation have been prepared (National Health & Medical Research Council, 1996). The level of treatment recommended is secondary plus filtration and pathogen reduction. Alternatives to this include constructed wetlands that may achieve treatment equivalent to open water areas which will allow pathogenic die-off due to UV sterilisation.

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The NSW Department of Health (1997) published "Waterless Composting Toilets Approval Guideline" in Part 3 of their Local Government (Approvals) Regulation 1993. There are moves afoot for the Health Department of WA to produce a version for Western Australia.

3. VERMICULTURE

A means of improving the performance of home compost bins to yield a soil conditioner of greater value is by adding worms. The process is, in fact, no longer composting but vermiculture and a different container can be designed to enhance the productivity. The action of earthworms, vermiculture, enables accelerated decomposition of organic matter. Vermicastings, the product of this action, have both increased available nutrients for soils and marketing value - an increase from some $A20/tonne to possibly $A500/tonne.

It will be necessary to modify conditions in the existing popular bins to produce a conducive environment for worm activity. Composting requires a moisture content of about 50%, carbon:nitrogen ratio of 30:1, aeration to satisfy oxygen demand of microbiological activity resulting in temperatures of up to 70 degrees C. in the thermophylic phase. Earthworms, however, can only survive in the lower temperatures in the range of 12-25 degrees C, enjoy a carbon: nitrogen ratio of around 50:1, a moisture content of around 60% and less aeration is required.

There are three main types of earthworms: • manure: 6 - 10 cm; • geophagous (horizontal burrowers): 0 - 30 cm; • deep burrowers: up to several metres long.

Tiger (Eisenia fetida) or Red (Lumbricus rubella) worms are the most effective for farming as they are ferocious eaters and fast breeders, as well as African Nightcrawlers (Endrilus eugeniae). Blue worms from India (Periomyx excavatus) may perform better in warmer parts of Australia than tigers and reds. The provision of a number of species widens the range of foods that will be readily consumed by the worms in your farm. Native worms with a lower metabolic rate are adapted to an environment of lower organic matter but will enhance soil quality if added to deficient gardens.

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Satisfactory containers that can be used by a small household, instead of the compost bins, are old refrigerators on their back, polystyrene seafood boxes, and half 44-gallon drums. Good bedding material for worms is provided by cow or horse manures mixed with shredded paper and moistened. Vegetable scraps are added on top (not mixed in so as to avoid high temperature composting) and worms will rise to the surface from the bedding to eat the decaying organic matter. Some 2kg of worms will typically consume 1kg of kitchen scraps a day. Around 1kg of worms can number between 1000- 4000 depending on maturity and typically sell at Perth worm farms for $A15-25. Under ideal conditions, 8 tiger worms will increase to 1500 in 6 months whereas red worms are not such rapid breeders. Damp hessian is an effective cover to worm beds as it breathes, can be kept moist, and thus maintains a lower than ambient temperature.

Vermiculture biotechnology can be used for processing domestic refuse after removal of solid, inorganic recyclables. Composting toilets can incorporate vermiculture. Agricultural wastes, manures and food processing wastes can all be processed by worms. Sewage effluent can be treated by means of vermifiltration with agricultural/horticultural reuse of the clean water. Western agriculture can be converted to a sustainable form through the addition of vermicastings from these waste treatment processes, the introduction of worms to the currently sterile soils, and termination of tillage. Worms themselves can be used as bait for recreational fishing and commercial aquaculture feedstock.

4. MECHANISMS OF VERMICOMPOSTING

More light has been shed on the mechanisms of the vermicomposting process based on the results obtained from trials by the Bathurst City Council (Scarborough, 1999). Scarborough indicated the entire process can be separated into three distinct stages (Fig. 1).

52 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS

Primary Decomposition Secondary Decomposition Worm Digestion Aerobic respiration rate increases

CO2 N2 O2 N2 O2 CO2

Organic matter consumed Hydrolysis produces + NH3 and NH4 Castings consisting of bacteria, organic matter, urea, and proteins.

Worm ingests organic matter, fungi, protozoa, Increased Organic matter consumed algae, nematodes surface area & bacteria Fixation, nitrification and hydrolysis Nitrogen fixation mainly reactions continue occurs on burrow walls with nitrification mainly occurring Green on the castings. Waste

- NO3 concentration increases

Increased aerobic respiration results in increased heat released, which further stimulates Leaching Biosolid Matrix microbiological growth.

Figure 1: Simplified representation of the vermicomposting process (Scarborough, 1999)

4.1 Worm Digestion

The worms ingest organic matter, fungi, protozoa, algae, nematodes and bacteria, which then passes through the digestive tract. The majority of the bacteria and organic matter pass through undigested (although the organic matter has been ground into smaller particles). This then forms the casting along with metabolite wastes such as ammonium, urea and proteins. The worms also secrete a mucus of polysaccharides, proteins and other nitrogenous compounds from their body. Through the action of ingesting and excreting food, worms create “burrows” in the material that in turn increases the available surface area and allows aeration in conjunction with the aeration already supplied by mixing the biosolids with the chipped green waste.

4.2 Primary Decomposition

Due to the abundant presence of nitrogen, oxygen and nitrogenous compounds (urea, proteins and ammonia) as part of the vermicast and mucus secreted from the external

53 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS tissues of the worms, aerobic microbiological growth increases. It is believed that the initial burst of microbiological activity mainly consists of nitrogen fixing bacteria, nitrification bacteria, and to a lesser extent, aerobic bacteria. This is based upon previously established information that burrow walls have a high proportion of the total nitrogen fixing [bacteria] and that casts have higher concentrations of soluble salts and greater nitrifying power. This was reinforced by the results of the trail, finding where there was up to twenty four times more nitrate in the experiment beds when compared to the control. Hydrolysis reactions also occur in the mixture, converting organic nitrogen compounds to ammonia and ammonium.

4.3 Secondary Decomposition

The hydrolysis of organic nitrogen compounds, nitrogen fixation and aerobic respiration (by aerobic bacteria) consumes organic matter, which further increases the surface area and aeration. This results in a further stimulation of microbiological growth especially the obligate aerobes present in the biosolids (such as Pseudomonas spp., Zoogloea spp., Micrococcus spp. and Achromobacter spp.). The explosion in microbiological population then increases the rate of decomposition of the material.

The chipped green waste is vital to the above mechanism. The 100% biosolids, whilst processed very heavily in the upper ten centimetres of the bed, turned anaerobic towards the end of the eight weeks at the depths of the bed, resulting in the objectionable odours typically associated with biosolids.

This mechanism also answers the questions about pathogen reduction / elimination. As the material becomes aerobic, the conditions begin to favour the obligate aerobes (microorganisms requiring oxygen to survive, grow and multiply). Pathogens typically are able to process nutrients and reproduce from a range of conditions ranging from aerobic to anaerobic. However, obligate aerobes have evolved to process nutrients and reproduce at the highest level of efficiency in aerobic conditions. Therefore, over time, the pathogens are competitively excluded from water, nutrients and space as the obligate aerobes population continue to increase under their ideal conditions. Virus and parasite reduction is believed to be attributable to a combination of a lack of exposure to host organisms (namely mammals) to reproduce themselves, exposure to a microbiologically active environment and the possibility of the worms utilising

54 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS viruscidal enzymes as part of the digestion process (Lotzof 1999) or simply by direct digestion.

5. DOMESTIC VERMICOMPOSTING TOILETS

The Dowmus vermicomposting toilet (Fig. 2) is an example of continuous system as opposed to the batch system. Dowmus rely on worms to break down the organic matter. The system is aerobic, completely smell free and uses no chemicals. Dowmus' dry (non-flush) system requires minimal maintenance. The system consists of a circular composting chamber, which is of a size suitable for a family of five. At the time of installation, compost and soil organisms including red worms and tiger worms are added to the system. The worms are the vital component in this system. Since it only reaches temperatures of 35 degrees Celsius, there are no active thermophilic organisms present. A family of five can use the Dowmus for a few years before the compost needs to be removed from the chamber.

Figure 2: Elevation section view of the Dowmus vermicomposting toilet

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The non-flush unit consists of a ceramic pedestal with a wooden seat and lid. Food, paper, cardboard, vacuum dust and tampons can all be put into the system, which is not harmed by bleaches and detergents, via the pedestal which sits directly over the chamber. However, plastic bags, disposable nappies, plastic coated boxes and garden refuse should not be added. The ventilation pipe and fan work from the bottom of the tank, dragging air through the compost, keeping it aerated and smell free. The fan requires low energy, and can be solar powered.

6. DOMESTIC VERMIFILTRATION SYSTEMS

The Dowmus vermicomposting toilet system can be upgraded to receive wastewaters - both blackwater and greywater (Cameron, 1994). In Canberra, the Australian Capital Territory (ACT), about 12 households have had trial systems installed for monitoring by the ACT Electricity and Water (ACTEW). Blackwater from the toilet enters a wet composting Dowmus tank with the effluent going to a second tank where greywater is also received. In this tank effluents are aerated around submerged volcanic rock media to achieve secondary standard treated effluent. From there the effluent goes to an irrigation storage tank in which chlorination occurs. The final effluent is mixed with rainwater to achieve further dilution and to improve the quality of water. Dowmus has been authorised to install five systems in Western Australia for trial.

A unit has been established at Murdoch University in the Environmental Technology Centre's permaculture system. The effluent from the unit is pumped to a series of constructed wetlands for further treatment prior to subsurface irrigation onto an orchard or percolation through the sandy soil back to groundwater.

A new modified design, involving 3 filter layers instead of the older single layer, was developed for an inner-city house in Sydney retrofitted on total sustainability principles (Mobbs, 1998) (Fig. 3).

56 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS

Figure 3: Elevation section view of the improved Dowmus vermifiltration unit.

7. MUNICIPAL VERMICOMPOSTING SLUDGE TREATMENT

Vermitech (Lotzof, 1999b) has, through the development of proprietary equipment and processes, created a system that can consistently and cost effectively, stabilise a large range of organic wastes including sewage sludge.

The critical elements of very large scale vermiculture are:

1. the preparation of the sludge prior to feeding to the worms; 2. the controlled application of the feed to the worm beds; 3. The raised cage bed structures; 4. the environmental control systems for managing moisture, temperature and wind; 5. worm biomass management; 6. harvesting of the vermicast; 7. post processing of the vermicast for sale; 8. leachate control; 9. sampling and analysis systems for sludge and vermicast; and 10. information management systems.

Sludge from a broad spectrum of sewage and water treatment plants is being stabilised and the end product sold. Dewatered sludge is taken directly from the treatment plant and fed to the worms without the need for any pre composting or aging. Systems have

57 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS been installed on a number of sites, the largest being a 400m3/week capacity facility at Redland in Brisbane Queensland. Testing has established that the vermicast meets the Grade A Stabilisation Standards. Contamination levels while dependent on input contaminants, are managed so that only Grade A or B level vermicast will be marketed. Contamination levels are controlled by analysing incoming sludges and blending in "clean" organic material to the feed mix to reduce the ultimate level. Extensive trials have established a very large market for vermicast. Grower results across a large range of crops, indicates a very large, sustainable market with pricing exceeding $A250/m3.

The installed system consists of a central worm farm on the Cleveland STP. The collection from each of the five treatment plants is by well proven covered hook lift mounted sludge bins. The worm farm is divided into two areas, the worm bed/waste receival area and the vermicast storage/ post processing area. The worm beds occupy an area of 100m x 80m. The surface is bitumen sealed and drains to a leachate dam with first flush control. The beds are galvanised steel frame with the waste and worm biomass contained within a raised mesh cage. The 14 beds are each 3.6m wide and 70 m long. The beds are modular and can be configured to any length. At Redland, the total available surface area for feeding exceeds 3,000m2 giving a capacity of 400m3/week. The additional 150m3/week capacity was put in place to enable the worm farm to process stockpiled sludge and to take other regional wastes.

The raised cage system is a continuous flow process. Waste is fed to the surface. The worms progressively stabilise the material. The fully stabilised material is harvested from the base. The design maximises the retention of the worm biomass, eliminating the need to separate the worms from the vermicast. It also optimises the environment to promote the development of beneficial bacteria and fungi.

The waste from the five sites is received into a bunded mixing area. Prior to the commencement of operations, sludge was collected from each of the five plants and fed to the worms over a six week period to determine the correct blending to ensure maximum attractiveness of the sludge to the worms. Each waste has its own blend requirement. The objective of blending is to deodorise and aerate the waste and adjust the Carbon/Nitrogen balance, the pH and salinity. A range of mineral, organic and bacterial additives may be mixed depending on the nature of the waste material and the state of the worm beds. The formulae are proprietary. The mixing has made all sludges worm accessible, even some "specially aged" material prepared for an odour/eatability

58 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS trial. The standard practice of collection, blending and feeding on the same day minimises the potential for any odour build up.

8. CONCLUSIONS

Domestic dry vermicomposting toilets can be used in National Parks (campsites), isolated roadhouses, farmhouses, and on peri-urban or semi-rural blocks under current legislation in Australia. Their use is ideal in places where disposal of effluent is difficult due to low soil infiltration, lack of availability of land, limited water resources, or in ecologically-sensitive areas. A greywater recycling system may still be needed where wet facilities are required. The mature vermicompost product is free of pathogens, ideal for the garden and results in a cycling of the nutrients. The domestic vermifiltration system can replace septic tank systems. This system avoids the need for periodic pumping of sludge as well as the need for two separate systems. Again vermicompost is produced for the garden and the treated effluent can be recycled on the garden by subsurface irrigation. Any system that requires disposal of effluent from septic tanks can use the vermifiltration method. Both dry and wet systems can receive the domestic organic wastes (food scraps, paper, cardboard, lawn clippings, chopped up garden prunings). The Vermitech sludge stabilisation process uses the same vermicomposting principles and can process successfully sewage sludge from municipal sewerage facilities as well as a range of other organic wastes.

9. REFERENCES

Beder, S. 1993. Pipelines and Paradigms: The development of sewerage engineering. Australian Civil Engineering Transactions CE35 (1) 79-85. Cameron, D. 1994. Compost Filtration: A new approach to on-site resource management. In: Mathew, K. & Ho, G. (Eds), Workshop on Localised Treatment and Recycling of Domestic Wastewater, RADG, Murdoch University. Gardner, T., P. Geary & I. Gordon. 1997. Ecological Sustainability and On-Site Effluent Treatment Systems. Aust J Env Management (4) September pp144-156. Goodland, R. & A. Rockefeller. 1996. What is Environmental Sustainability in Sanitation? Insight, UNEP-IETC Newsletter, Summer. Jeppeson, B. 1996. Model guidelines for domestic greywater reuse for Australia. Research Report # 107, Urban Water Research Association of Australia, Melbourne.

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Kourik, R. 1995. Graywater for Residential Irrigation. Landscape Architecture 85 (1) pp30-33. Lotzof, M. 1999. Very large scale vermiculture in sludge stabilisation. Proceedings from the 13th WWM National Conference on Waste Management. Lotzof, M. 1999b. www.eidn.com.au/technicalpapervermiculture.htm and www.vermitech.com/ Lotzof, M. 1999c. The wonder of worms for sludge stabilisation. Water, Australian Water & Wastewater Association, Sydney. January/February, pp38-42 Ludwig, A. 1994. Create an Oasis with greywater. Oasis Design, Santa Barbara. Ludwig, A. 1995. Building Professional's greywater Guide. Oasis Design, Santa Barbara. Mathew, K. & G. Ho. 1993. Reuse of wastewater at Jigalong Aboriginal Community. RADG, Murdoch University. McQuire, S. 1995. Not Just Down the Drain: A guide to reusing and treating your household water. Friends of the Earth, Melbourne. Mobbs, M. 1998. Sustainable House. Choice Books, Sydney. National Health & Medical Research Council. 1996. Draft Guidelines for sewerage systems - use of reclaimed Water. National Water Quality Management Strategy, Melbourne. New South Wales Recycled Water Coordination Committee. 1993. New South Wales Guidelines for Urban and Residential Use of Reclaimed Water. Public Works Department, Sydney. Newman, P.W.G. and M. Mouritz. 1996. Principles and planning opportunities for community scale systems of Water and Waste Management. Desalination 106 pp339-354. Niemczynowicz, J. 1993. Water management and ecotechnology - towards 2020. Workshop on Sustainable Urban Water Systems and Ecotechnology. November 18, ISTP/RADG, Murdoch University, Perth. Race Discrimination Commissioner. 1994. Water - A report on the provision of water and sanitation in remote Aboriginal & Torres Strait Islander Communities. HREOC, AGPS, Canberra. Scarborough, J. 1999. Biogreen Castings - Scientifically assessing the merits of vermicomposting biosolids and green waste mixes. Proceedings of Enviro 2000: Towards Sustainability. Waste Management Association of Australia, 9-13 April 2000, Sydney. Standards Australia. 1994. Disposal systems for effluent from domestic premises, AS 1547- 1994, Standards Australia, Homebush, NSW.

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Standards Australia/Standards NZ. 2000. On-site domestic wastewater management, AS/NZS 1547-2000, Homebush/Well.

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PRINCIPLES OF WATER AUDITING IN THE CONTEXT OF WATER CONSERVATION

J. J. STURMAN, K. MATHEW & G. HO

ABSTRACT

Water auditing is set in the context of a global vision for water. Water auditing can be defined quite narrowly as the determination and comparison of the quantity and quality of water inputs and outputs to and from a process. More broadly, while water auditing is a quantitative process, it is as well as an art, seeking ways of reducing water usage from sources supplying a process, and from within complex water stream feedback systems. Water auditing is a tool to address quantitatively our growing awareness of the need to conserve water. Water auditing is not merely a subset of environmental auditing, but has much in common with environmental management systems. Global shortages of water of appropriate quality for a variety of uses are already apparent and will grow in the future. Water auditing is a mechanism that can contribute to local and global water conservation.

1. INTRODUCTION

Abu-Zeid (1998) has identified an array of challenges facing the world in relation to water in a keynote address to the World Water Council in 1998 and we choose this one significant paper to structure our discussion. He characterised the world’s fresh water situation as being in a state of crisis, exacerbated by climatic fluctuations. Throughout the next century he believes that current world water shortages will multiply quickly. Among others he identifies these challenges: water scarcity, lack of accessibility to clean drinking water and sanitation and deterioration of water quality. While Abu-Zeid (1998) focuses on fresh water, much life depends upon non-fresh water too.

He believes water management is fragmented on a world-wide scale, with a vacuum at the apex of management and a confused array of weak institutions at the base. Financial support for a wide range of water supply, management, conservation and control matters is lacking to the extent of endangering public safety. The public, decision- makers, education systems, the media and others seem unaware of threats to the

62 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS continued availability of good quality water, or that the sustainability of the planet is being threatened.

In response to these challenges, Abu-Zeid (1998) reports a set of guiding principles to develop a vision for water in the world, for life and for the environment. Here we simply report three of the guiding principles among many: 'apply integrated water resources management', 'value water' and exercise 'will and commitment to translate vision to action'. Will and commitment connect the vision to a set of targets, mechanisms and actions. The targets identified by Abu-Zeid (1998) are as follows: Clean drinking water and adequate sanitation, secured food supply, conservation of the environment (and therefore of water1), preservation of bio-diversity, sustainable economic growth and development and, finally, the promotion of world peace and security. Mechanisms are necessary in order to implement the vision with respect to the targets identified.

The mechanisms listed are certain to become incomplete as the world changes. Nevertheless specific mechanisms for the present are identified as: broadening the participation of stakeholders; raising public awareness; raising the capacity of institutions, staff and technological resources – especially within developing countries; development of technology through research and development – including conservation technologies and management systems and finally funding and mobilisation of finance.

Water auditing engages the wider issues identified within the guiding principles, targets and mechanisms. The material we have presented provides background values and motivation for water auditing. Particularly we locate water auditing within the mechanism ‘development of technology’, in our case intellectual technology. Yet this ought not to be taken in too restrictive a sense. The guiding principles of water auditing and water conservation include valuing water, and responsibly managing it. Water auditing requires: enhanced awareness of the public and of decision makers, common and shared world interests, expanded capacity for dealing with water issues within and without enterprises (or even countries), to name just a few.

1 Author's addition.

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2. THE BASIC WATER AUDITING PROCESS

In its narrowest interpretation, water auditing amounts to the discipline concerned with quantifying water usage or discharge. In figure 1 we illustrate this essential process.

Defined boundary around selected processes or units

Processes which use water and are at steady state Water inputs Water outputs from several of several qualities sources to several sinks

Water audit domain

The sum of water - The sum of water Closure: input quanities output quanities predetermined The sum of water input quanities < tolerance

Figure 1. The quantitative heart of the water auditing process, with a definition of closure.

The closure process gives rise to the term ‘water auditing’. Yet this does little justice to the sophistication of the actual practice of water auditing in Australia. Therefore we will broaden our view so as to see the typical water audit process from the view of the water auditing practitioner.

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Water Audit Process

Phase one - audit preparation Audit scope and objectives

Selection of audit team Audit schedule Resources

Identify unit operations Flow diagram Development plans

Phase two - conducting the audit Material balance (flow measurement) Water quality

Input water Output water Sampling and monitoring Quantity, sources Quantity, sinks

Closure, Audit evidence, data, findings

Phase three - water management strategy List water waste reduction, reuse and recycling options

Evaluate options and conduct financial assessment of each option

Design a water management strategy

Phase four - audit report Audit report writing and liason

Summary and recommendations

Communication and presentation of results to client, auditee

Figure 2. The water auditing process as practiced by professional water auditors. This diagram is a reworked form of a similar diagram originating in Dawson (1997)

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3. THE PRACTITIONER'S WATER AUDITING PROCESS

This view is summarised in figure 2. We notice first that phase two in figure 2 summarizes figure 1. Though not explicitly stated in figure 1, the water auditor is concerned with reducing inputs’ quantity and quality, while reducing discharge quantities and increasing quality through treatment processes. The audit preparation, water management strategy and water audit report phases 1,3 and 4 add to the incomplete description of water auditing in figure 1. We will comment briefly on each of these three phases.

The audit preparation phase is noteworthy for the entries 'audit scope and objectives' and 'development plans'. Buried within these terms are concerns for water conservation, often extending beyond the bounds of the audit proper. For example, development plans for a site might either anticipate generating waste water which could be used as a resource for other nearby enterprises or make it possible to utilise as an input waste water from a nearby site. In either case, water use from yet other sources could be limited or rendered unnecessary. Thus broader matters of water conservation could be served.

The phase 'water management strategy' is a creative phase, in which the character of water auditing as an art as well as a science is revealed. It involves assessment of water sources, assessment of water discharges and sinks, evaluation of water use in unit processes, investigation of possibilities for saving water by quantity or quality. Water resource substitution, water recycling, reuse, cascading of waste water from high quality streams in the hierarchy of quality to inputs where lower quality water is acceptable are all tools of the process. Added to these, economic evaluation is undertaken of the variety of ways in which water use could be reduced. Possible long- term developments of the arena of the audit are re-examined, together with the implications for water use in the long term. Water auditing is a repetitive process, which issues in a water management strategy, which itself is tested by future audits. Thus the scheme of figure 2 captures only the process of one audit in a series.

Phase four, the 'Water audit report' sounds mundane and straight forward. It too has hidden within it important processes, hinted at by the words 'liaison' and 'recommendations'. We recommend to those doing water audits under our supervision that they consult extensively with management throughout the audit and present their

66 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS proposed water management strategy to both client and auditee (where different) in a seminar form prior to delivering a final written report. This enables the water management strategy to be compared with the auditee's environmental policies and environmental management strategy, as well as canvassing broader financial issues, which might impact upon implementation of the water management strategy. Notice that implementation does not appear as a phase in figure 2, as the implementation is in the hands of the client and the auditee, not the water auditor.

We have extracted from figure 2 material that is hidden under the summarising words of several phases. Also we have flagged that 'implementation' lies outside of the water auditor's task. It seems that figure 2 is not able to carry the burden of the full meaning of water auditing, just as figure 1 wasn't able to do so either. We will look at water auditing in a broader context still.

4. WATER AUDITING AND ENVIRONMENTAL MANAGEMENT SYSTEMS

Table 1 compares the environmental management system model (ISO 14001:1996 and ISO 14004:1996) with the water auditing process. Notice that in the ‘water auditing process’ column of table 1 the items ‘Water conservation…’ and ‘Implementation’ appear, whereas they did not appear in figure 2. This is because of the expanded horizon of water auditing, which results from including the client and auditee (where different) as well as the water auditing practitioner.

Environmental management systems (EMSs) and water auditing The Environmental EMS model The water audit process (holistic) Commitment and policy Commitment to water conservation, clean discharges, financial evaluation Planning Water audit process phases 3 and 4 Implementation Implementation by client and auditee Measurement and evaluation Water audit process phases 2 and 3 Review and improvement Water audit process phases 3 and 4

Table1. A comparison of the Environmental Management System model of the ISO 14000 series with the water auditing process, taking the broader view of water auditing that includes the client and auditee as well as the water auditing practitioner.

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Table 1 demonstrates the significant parallels in the environmental management system model and the broader perspective of the water auditing process. The environmental management system will put in place criteria for an environmental audit to check against, and this is true too for at least the wastewater audit part of water auditing. Yet the total water audit is concerned with achieving commitment to water conservation, water resource substitution, reuse and recycling and positive financial outcomes for the auditee where possible. Thus the water audit is not just a part of an environmental management system as is an environmental audit (see ISO 14001:1996, ISO 14004:1996, and for environmental audits ISO 14010:1996); the water audit is itself a water oriented form of environmental management system. This we summarize in figure 3, which demonstrates the relationship between environmental management systems, environmental auditing and water auditing.

EMS

Envir. Water audit audit

Figure3. The qualitative relationship between Environmental Management Systems, environmental audits and water auditing.

5. WATER AUDITING, CONSERVATION OF RESOURCES AND POLLUTION CONTROL

We have alluded to the satisfaction of criteria that is the basis of an environmental audit and hinted that the water audit aspires to more than merely meeting criteria. This raises the issue of the relationship between resource conservation and pollution control. Figure 4 shows the relationship between pollution control, basic resource conservation

68 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS and water conservation, the basic value underlying water auditing. We believe that environmental auditing is weighted somewhat towards pollution control, while water auditing is weighted towards basic resource conservation. Thus environmental auditing tilts towards conformity with criteria related to pollution control, while water auditing tilts towards water conservation apart from pre-determined criteria. We caution that these observations are matters of emphasis only.

Basic resource Pollution conservation control

Water conservation

Figure 4. The qualitative relationship between Basic resource conservation, pollution control and water conservation.

6. CONCLUSIONS: WATER AUDITING AND THE BIG PICTURE

We have dealt with the principles of water auditing in the context of water conservation. Water auditing is indeed a mechanism, an intellectual technology for quantifying water paths as is illustrated in figure 1. Yet its scope extends beyond the mere reconciliation of water input and output quantities and measurement of water quality. From the water auditor's point of view it involves a set of rich imaginative tools for reducing water use and so conserving water as well as minimising and treating discharges. It embraces a set of values and a process akin to an environmental management system. While its focus is on water conservation, pollution control and basic resource conservation have interactions in general and this is true for water quality and water conservation too. Water auditing is visionary in its scope and mechanistic in its quantification of water stream flows, with a view to contributing to

69 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS sustainable development. Water auditing can be seen as a crucial mechanism within a broad vision of water and the world such as that articulated by Abu-Zeid (1998). In particular we ask 'can worldwide water conservation proceed without the detailed quantification provided by water auditing?' We think not and suggest that the usual application of water audits to commerce, industry and to small or regional geographical scales be extended to undertake a global water audit. Who will grasp such a challenge?

7. REFERENCES

Abu-Zeid M. A. (1998) Water and Sustainable development: the vision for world water, life and the environment. Water Policy , 1, 9 – 19.

Dawson, M.D. (1997) Water audit guide. Case study - Wesfarmers CSBP Limited Kwinana Works. Independent study contract dissertation, School of Environmental Science, Murdoch University, Murdoch, Western Australia.

AS/NZ ISO 14001:1996 Environmental management systems – specification with guidance for use. Standards Australia and Standards New Zealand.

AS/NZ ISO 14004:1996 Environmental management systems – General guidelines on principles, systems and supporting techniques. Standards Australia and Standards New Zealand.

AS/NZS ISO 14010:1996 Guidelines for environmental auditing – General principles. Standards Australia and Standards New Zealand.

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THE H2S METHOD FOR TESTING BACTERIOLOGICAL QUALITY

OF DRINKING WATER IN REMOTE COMMUNITIES

J. NAIR, K. MATHEW & G. HO.

INTRODUCTION

Microbial quality of drinking water is a major problem in rural areas of both developed and developing countries. One of the reasons is the remoteness of the place that prevents regular collection of samples and testing. Only an onsite method that is affordable and simple to conduct will be suitable for such locations. It has been noted that the H2S method meets these criteria. In indigenous communities around Western Australia there is a high prevalence of water related diseases (Henderson et al., 1996). Low quality water is often continually consumed in many communities. Isolation and severe unpredictable weather patterns as well as distance from laboratories affects the frequency of which tests are conducted. The routine testing of water is a public health requirement and it is recommended by the National Health and Medical Research Council that water be tested for it’s microbial constituents as least once a month, preferably fortnightly (NHMRC, 1998). Unfortunately for communities that do not have the level of infrastructure, population and co-ordination, this frequency of testing is not a service that they can receive. On-site method of testing of water in remote areas offers the communities a quick, accurate and low cost method for testing their water at any time.

The H2S method developed by Manja et al. (1982) has been trialled in remote Aboriginal Communities in Australia. The method test for the presence of sulphate reducing bacteria which is commonly present in the intestine and in wastewater. The method has been tested in the laboratory and was found to give satisfactory correlation with the coliform method, which is a standard method for testing drinking water (Nair et al., 2001). However implementation of the method in Communities requires a scheme of planning including a scheme of negotiation, training, management, feedback and record keeping. This paper describes the various steps required to field trial the method in remote Communities based on the trial that was carried out in Aboriginal Communities in Australia.

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1. BACKGROUND

Epidemics can occur due to contamination of water supplies, which include all types of gastro-intestinal diseases. Prevention of these diseases is of great importance because it can spread in a community very fast and have the potential to affect the entire community. On a world wide scale diarrhoea was estimated to have killed 2 million children and to have caused 900 million episodes of illness annually (World Development Report 1992). In Western Australia it has been reported that Aboriginal children who are under five years of age are hospitalised for gastroenteritis at a rate seven times higher than that of non-Aboriginal children (EHNCC 1997).

Western Australia has about 260 discrete Aboriginal Communities, many of these have satellite communities which are often called outstations. Of these communities 56 have regular bacteriological testing carried out at least once a month. This testing is carried out by a trained service provider, who is contracted by the state government. There are four such service providers in Western Australia. This is due to the vastness and differences between the areas in Western Australia (WA). From among the communities in Western Australia, 64% do not receive monthly bacteriological testing from government funded sources and 75% do not have water disinfection facilities.

The bacteriological test to be recommended to remote localities should be simple to operate and interpret and less expensive and will be more advantageous if the testing can be done by local people with minimum training.

The Remote Area Developments Group (RADG) at Murdoch University has conducted various laboratory studies on Hydrogen Sulphide paper strip method (H2S method) to asses its suitability to test various types of water samples. Although this method does not directly detect any specific bacteria a good correlation has been obtained with the results from this test and with the standard tests for detecting coliforms in drinking water (Pillai et al., 1999; Castillo et al., 1994). The main advantages of this test are that it is much cheaper, do not require any technical support on site and can be conducted by any local person after a minimum training. In that way this method gives economic benefit to the remote communities in terms of transport, salary of technical people and others involved in taking the sample to the laboratory within 24 hours and the expensive laboratory procedures. The method does not require any incubator or refrigerator to store the chemicals even for longer period.

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In order to implement an on-site drinking water testing project, a detailed program needs to be established to ensure its smooth running which includes a scheme of negotiation, training, management, feedback and record keeping.

2. PREPARATION OF INFORMATION PACKAGE

Information package for training included a booklet with graphic description of the procedures to follow and a video showing step by step procedure of the testing. The information booklet and video are prepared in simple language so that any community member who is interested in testing would be able to understand.

Incubator:

It has been noted that a constant temperature incubator is not required for the H2S method if the room temperature is between 28 oC and 42oC. However as a precaution for the winter months and cold nights when the temperature can drop below this temperature, a simple incubator was prepared by modifying a yogurt maker that can accommodate 5 sample bottles.

Preparation of the medium and the H2S bottles

The H2S medium was prepared by dissolving peptone (20 g), di potassium hydrogen phosphate (1.5 g), ferric ammonium citrate(0.75 g), sodium thiosulfate(1 g), 0.125 g of L- cystine and teepol (detergent)(1 mL) in 50 mL of tap water. The medium (5ml) was dispensed into 120ml labelled bottles and sterilised. The bottles were sealed properly to prevent leakage.

The H2S kit

The H2S water test kit suitable to be carried to the Communities consisted of a video, a booklet, an incubator, 12 H2S bottles, disinfectant, towel, pen, data recording and result faxing sheets in a 32 litre plastic storage container. Methylated spirit was prohibited in many communities therefore they were asked to heat the tap with candle before sample collection.

Method of testing water: To conduct a test the incubator was firstly turned on and the hands of the person conducting the test was thoroughly washed to prevent any chance of contamination.

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The tap must be cleaned and sterilised, which involved removing the excess dirt and grime with a clean cloth. Using a naked flame the tap was heated so that the water within the tap boils. The tap was then flushed for 20 seconds before a sample was taken. The bottle containing the medium was filled to the line marked on the side. Caution was taken to ensure that the tester did not wrongly contaminate the inside of the bottle or cap. The lid was closed tightly and the bottle was shaken until all the chemical powder was dissolved. Following normal scientific procedure the bottle was labelled with the date, time and place from where that sample was taken from and the name of the sampler. After 24 hours the bottles were checked and the results faxed. The presence of contamination is indicated by the water sample changing to black colour and no colour change indicate safe water. The sample bottle no matter what the results were then filled to the rim with bleach to disinfect. The empty bottles were stored in a safe place and handed to the Environmental Health Worker for disposal.

3. TESTING PROGRAMME

Selection of the Communities: Communities were selected based on the recommendations by the Health department of the State. They were explained about the need for regular testing of the water, the project and the benefits of using the method to the communities. The communities were contacted to obtain their permission, support, willingness to participate in the study and explained about the procedure either by one of the members in the group or by the responsible person from Health department. In general the community was contacted 2 months before visiting, to let the community members and management know of the program and to see if the community considered inclusion in the testing program. A follow up phone call was made to the community to confirm inclusion. Once the participating communities had been established and divided into geographical areas, the field trips and workshops were planned.

The communities were visited by a member of the Remote Area Developments Group (RADG) to:

1. Introduce the project of on site testing to the community 2. Train the local Aboriginal people with the skills to conduct the test 3. Establish a structure for the support of the water testing program

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4. Establish and activate a support mechanism within the community to ensure the provision of safe drinking water

5. Provide the community with the H2S test kit 6. Improve the communities perceptions of the hazards of drinking contaminated water

Generally the Environmental Health Worker, the nurse or the school teacher were trained to conduct the water testing as well as the community development advisers or coordinators. Each community was supplied with all the consumables to conduct the test for six months. They were asked to test the water sample every fortnight and fax the results to Murdoch University. They were asked to report to the concerned agency if any in place about the water quality problem. The Communities were also asked to boil the water before consumption until the problem has been sorted out.

4. OBSERVATIONS AND RECOMMENDATIONS FOR IMPLEMENTATION OF

THE H2S METHOD IN REMOTE LOCATIONS

1. The H2S method is an ideal method for regions and Communities where other methods are not feasible 2. There is a tendency for the communities to lose interest in water testing after a while, particularly when they start getting consequent results 3. Water testing should be a paid job for a responsible person in the community 4. Frequent initial visits or contacts to the Communities until at least the program has been established 5. The responsibility could be entrusted to different people in the order of availability such as the school teachers, Community Nurse or Health worker so that if one person is unavailable test could still be done. 6. Continued communication with the communities to check whether regular testing is conducted 7. Correlating the water test results with the prevalence of gasterointestinal disease in the Community 8. If required Community should be encouraged to test household samples, which

is possible with the H2S method 9. Meeting with the water testing group in the community twice a year to discuss any issues of water quality problems and concerns

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5. REFERENCES

Castillo, G., Duarte, R., Ruiz, Z., Marucic, M.T., Honorato,B., Mercado,R., Coloma, V., Lorca,V., Martins,M.T. and Dutka, B.J. (1994). Evaluation of disinfected and

untreated drinking water supplies in Chile by the H2S paper strip test. Water Research. 28:1765-1770 Environmental Health Needs Coordinating Committee (EHNCC) (1997) Environmental Health Needs of Aboriginal Communities in Western Australia Health Department of Western Australia Manja, K.S., Maurya, M.S. and Rao, K.M. (1982). A simple field test for the detection of faecal pollution in drinking water. Bulletin of the World Health Organisation. 60: 797-801.

Nair, J., R Gibbs, K Mathew, and G E Ho (2001), Suitability of the H2S Method for testing untreated and chlorinated water supplies. Wat.Sci.Tech., 44(6): 119-126 NHMRC (1998). Australian Drinking Water Guidelines, NHMRC, Dept of Health, Canberra

Pillai J, K.Mathew, R.Gibbs and G.E. Ho (1999). H2S Paper Strip Method-A Bacteriological Test for Faecal Coliforms in Drinking Water at Various Temperatures. Wat. Sci.Tech., 40(2): 85-90. World Development report (1992). Development and Environment Oxford Uni Press, London

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07 ABOUT THE MONTEVERDE INSTITUTE

The Monteverde Institute was founded in 1986 and is a member-based Costa Rican non- profit educational and research association. In partnership with universities around the world, it designs and administers courses of international study in areas such as tropical ecology, sustainable development, conservation biology, political economy, woman studies, agricultural ecology, and public health. As a local institution deeply rooted in and committed to the Monteverde community, the Institute also provides local educational, cultural and social programs.

The Institute is committed to sustainable development in all its forms and since its inception has been actively investigating the environment and health impacts due to human activities in the region. Water quality issues have received much attention in recent years due to the region’s rapid growth and to this end the Institute initiated an extensive water quality testing program of local rivers in 1999 in collaboration with Smith College, Massachusetts. A doctoral candidate has commenced researching ecological sanitation options suitable for Costa Rica and Central America as a result of collaboration with METC and MVI. A range of ecological wastewater treatment technologies have been established in the area through this program and are presently being monitored, with further systems in the planning stage.

The Institute is well placed to host this Foundation Workshop as it offers the necessary facilities, experience and national and international reputation to draw on the necessary contacts to ensure a rewarding a successful event. The Institute believes that this workshop will come at a time of great need not only for the environment and public health in Central America but also for the great potential collaboration amongst practitioners in the field.

For more information visit: www.mvinstitute.org

08 ABOUT THE MURDOCH UNIVERSITY ENVIRONMENTAL TECHNOLOGY CENTRE

The Environmental Technology Centre (ETC) is a Centre of Excellence for Industry focussed Research & Development in Environmental Technology. It receives recognition and funding from the Western Australia Department of Commerce and Trade for this particular purpose. The ETC is a Partner Centre for the Asia Pacific

77 INTERNATIONAL WORKSHOP ON SUSTAINABLE SANITATION – RESOURCE PAPERS region of the United Nations Environment Programme International Environmental Technology Centre.

The ETC was established in 1992, and officially inaugurated in 1994 during the National Conference on Technology Transfer in Remote Communities. The ETC was established by the Remote Area Developments Group of the Institute for Environmental Sciences at Murdoch. The aim of the ETC is to research, develop and demonstrate environmental technologies, conduct education and training, provide consultancy services to industry, and raise community awareness of environmental technologies. Its facilities are open to industries wishing to test and monitor products within the university infrastructure.

The ETC occupies a 1.7 hectare site on the Murdoch University campus at which thirty- two environmental technologies have been combined to form an integrated operating demonstration system. The technologies used and researched at the site include climate-sensible buildings, renewable energy systems for power supply and water pumping, aquaculture systems, organic waste management, and permaculture. The integrated approach allows research to be carried out on the important interactions between different technologies, rather than just the effect of a single technology. This gives the ETC a considerable advantage over other research institutions which focus on single technologies in relative isolation.

The ETC is able to offer holistic and flexible solutions to human needs. The ETC’s focus is on small-scale environmental technologies, which are low cost, robust, efficient, and easy to operate and maintain. The aim of this is to maximise the opportunities for user communities to “own” the technology, resulting in greater and more sustained uptake of the technology, higher levels of community awareness and involvement, and ultimately a more successful operation. This approach has been successful in remote areas in Australia, and is highly applicable to communities in developing countries, as well as to urban communities worldwide, particularly when applied in collaboration with industry and government.

For more information visit: wwwies.murdoch.edu.au/etc