the winston churchill · the breadth and quality of practical experience and professional exposure...

Report by Dr Declan Page - 2010 Churchill Fellow

Assessment of natural treatment systems for Australian applications in water supply and water recycling

I understand that the Churchill Trust may publish this Report, either in hard copy or on the internet or both, and consent to such publication. I indemnify the Churchill Trust against any loss, costs or damages it may suffer arising out of any claim or proceedings made against the Trust in respect for arising out of the publication of any Report submitted to the Trust and which the Trust places on a website for access over the internet. I also warrant that my Final Report is original and does not infringe the copyright of any person, or contain anything which is, or the incorporation of which into the Final Report is, actionable for defamation, a breach of any privacy law or obligation, breach of confidence, contempt of court, passing-off or contravention of any other private right or of any law.

Signed: Dated: 1 December 2010

THE WINSTON CHURCHILL

MEMORIAL TRUST OF AUSTRALIA

Cover Photograph Amsterdam Water Supply Dunes (near Zandvoort) Photograph: Anna Le Poidevin © 2010

CONTENTSCONTENTSCONTENTSCONTENTS

EXECUTIVE SUMMARYEXECUTIVE SUMMARYEXECUTIVE SUMMARYEXECUTIVE SUMMARY ................................................................................................................................................................................................................................................................................................................................................................................................................................................ 3333

PROGRAMMEPROGRAMMEPROGRAMMEPROGRAMME OCTOBEROCTOBEROCTOBEROCTOBER––––NOVEMBER 2010NOVEMBER 2010NOVEMBER 2010NOVEMBER 2010 ........................................................................................................................................................................................................................................................................................................ 5555

WATER SUPPLY & RECYCLING IN AUSTRALIAWATER SUPPLY & RECYCLING IN AUSTRALIAWATER SUPPLY & RECYCLING IN AUSTRALIAWATER SUPPLY & RECYCLING IN AUSTRALIA.................................................................................................................................................................................................................................................................................................... 6666

NATURAL TREATMENT SYSTEMS ................................................................................................... 7

MANAGED AQUIFER RECHARGE (MAR)...............................................................................................8 WETLANDS & STORAGE RESERVOIRS ............................................................................................. 10

WHY TRAVEL TO THE MIDDLE EAST, EUROPE AND THE USA?WHY TRAVEL TO THE MIDDLE EAST, EUROPE AND THE USA?WHY TRAVEL TO THE MIDDLE EAST, EUROPE AND THE USA?WHY TRAVEL TO THE MIDDLE EAST, EUROPE AND THE USA? .................................................................................................................................................................................... 12121212

UNITED ARAB EMIRATES .............................................................................................................. 12

GERMANY ...................................................................................................................................... 16

BERLIN ......................................................................................................................................... 16 DUSSELDORF AND FRANKFURT....................................................................................................... 18

THE NETHERLANDS....................................................................................................................... 19

SPAIN ............................................................................................................................................ 21

UNITED KINGDOM......................................................................................................................... 22

UNITED STATES OF AMERICA ....................................................................................................... 23

CONCLUSIONS & RECOMMENDATIONSCONCLUSIONS & RECOMMENDATIONSCONCLUSIONS & RECOMMENDATIONSCONCLUSIONS & RECOMMENDATIONS ............................................................................................................................................................................................................................................................................................................................ 26262626

INTRODUCTIONINTRODUCTIONINTRODUCTIONINTRODUCTION

I have been involved with drinking water quality and treatment, and more recently water

recycling and reuse, for over a decade since completing my PhD at the Cooperative Research

Centre for Water Quality and Treatment, UniSA. After I graduated in 2000 I worked as an

Environmental Consultant in Canberra assessing conventional engineered water treatment as

well as catchment management to protect drinking source water. In 2003 I accepted the role of

Senior Resource Manager with the Northern Territory’s Power and Water Corporation. In this

role I had the privilege of working intensely with water quality and risk management to help

develop the framework for managing water quality which now underpins the Australian Drinking

Water Guidelines (2004) and the World Health Organisation (WHO) Guidelines for Drinking

Water Quality (2004).

After taking up a position at the CSIRO in 2005, I became directly involved in the National Water

Quality Management Strategy (NWQMS) through the development of the Australian Guidelines

for Water Recycling (Phase 2): Managed Aquifer Recharge. These guidelines build upon years

of CSIRO research in the area of Managed Aquifer Recharge (MAR), a method increasingly

used to facilitate water recycling via aquifers. Unfortunately assessing the natural treatment

provided by aquifers has been difficult as traditional controlled scientific methods used in

engineered technologies are not possible to apply with natural systems. This is an international

problem and, as a result, these natural systems are not fully recognised for their role in water

supply and recycling. I believe that with the increasing pressures of climate change and

urbanisation placing stress upon valuable water resources we require now, more than ever, a

natural treatment system1 to protect human health and the environment.

I am extremely grateful to the Winston Churchill Trust for the opportunity to observe and

collaborate with international scientists and engineers to work towards water supply and

recycling solutions. Travelling the globe and representing the Winston Churchill Trust enabled

me to achieve several career and personal milestones such as attending the 7th International

Symposium on Managed Aquifer Recharge (ISMAR7) in Abu Dhabi and presenting the

Australian Risk Management Framework at the UNESCO workshop • visiting researchers in

Germany where bank filtration has been used for over 100 years • talking with scientists in the

UK where novel passive sampling devices have been developed to help monitor for organic

chemicals present in recycled water • reviewing the results of the recently completed EU

research project RECLAIM WATER in Spain • and visiting researchers in the USA where

pioneering research for assessing organic chemical decay in wetlands is being undertaken. 1 Including aquifer recharge, bank filtration, wetlands and open reservoir detention.

The breadth and quality of practical experience and professional exposure the Winston Churchill

Trust Fellowship has provided me has been absolutely invaluable and critical to furthering my

ability to help make significant and lasting contributions to the successful management of

Australia’s precious water resources.

ACKNOWLEDGEMENTSACKNOWLEDGEMENTSACKNOWLEDGEMENTSACKNOWLEDGEMENTS

Dr Peter Dillon, CSIRO Land and Water

Mr Paul Heaton, Power and Water Corporation

Ms Ann Holding, Qantas Limited

Ms Julia Weston, Winston Churchill Memorial Trust, United Kingdom

Mr Geoff Sauer, Winston Churchill Memorial Trust, South Australia

Mr Jamie Balfour, Winston Churchill Memorial Trust, United Kingdom

Dr Gesche Grützmächer, Kompetenz Zentrum Wasser, Berlin

Dr Sondra Klitzke, Umweltbundesamt, Berlin

Dr Christian Kazner, RWTH Aachen University

Prof Thomas Wintgens, Fachhochschule Nordwestschweiz, Institut für Ecopreneurship

Prof Jack Schijven, National Institute for Public Health and the Environment (RIVM)

Dr Harold den Berg, National Institute for Public Health and the Environment (RIVM)

Dr Miguel Salgot, University of Barcelona

Ms Maria Neus Ayuso-Gabella, University of Barcelona

Dr Graham Mills, Portsmouth University

Dr Martyn Jevric, Oxford University

Mr Edwin Lim, Todd Engineers

Prof David Sedlak, University of California, Berkley

Ms Anna Le Poidevin, Anna Le Poidevin Professional Editing Services

The dedicated, inspirational and hospitable staff from Kompetenz Zentrum Wasser Berlin •

Umweltbundesamt • RWTH Aachen University • The National Institute for Public Health and the

Environment (RIVM) • University of Barcelona • Portsmouth University • University of California.

EXECUTIVE SUMMARYEXECUTIVE SUMMARYEXECUTIVE SUMMARYEXECUTIVE SUMMARY

Dr Declan Page

103b Sydenham Road

NORWOOD SA 5067

Project Leader – Managed Aquifer Recharge, CSIRO Land and Water

Phone +61 8 8303 8748

The Churchill Fellowship to assess natural treatment systems for Australian applications in water

supply and water recycling (United Arab Emirates, Germany, the Netherlands, Spain, the UK

and the USA).

HIGHLIGHTSHIGHLIGHTSHIGHLIGHTSHIGHLIGHTS

> Attending the 7th International Symposium on Managed Aquifer Recharge, Abu Dhabi, United

Arab Emirates.

> Visiting Kompetenz Zentrum Wasser Berlin, Umweltbundesamt Berlin, RWTH Aachen

University, and Fachhochschule Nordwestschweiz to work with researchers involved in water

recycling via natural treatment systems and characterisation of natural treatment processes.

> Visiting Dr Graham Mills at the Environmental Chemistry, Ecotoxicology and Monitoring

Group at the University of Portsmouth, UK to develop the ChemCatcher™ passive samplers

application to Managed Aquifer Recharge treatment validation.

> Visiting Dr David Sedlak at the Civil and Environmental Engineering Research Group at the

University of California, USA to learn new experimental methods to determine the fate of

endocrine disrupting chemicals in wetland systems.

RECOMMENDATIONSRECOMMENDATIONSRECOMMENDATIONSRECOMMENDATIONS

I fully endorse and support the risk-based approach of the NWQMS and the MAR Guidelines.

These recommendations are based on the integration and valuing of natural treatment systems

for water supply.

> Increase awareness of natural treatment system potential by State and federal agencies to

accelerate adoption where appropriate.

> Develop a national validation framework for water recycling schemes. The framework will

support the validation of individual treatment processes for use in water recycling schemes

around Australia.

> Support the development of natural treatment technologies demonstration sites (e.g. bank

filtration, managed aquifer recharge) across Australia in every State.

> Support research to develop standardised methods to characterise the limitations of natural

treatment systems as barriers to manage risks to human health and the environment.

IMPLEMENTATION AND DISSEMINATIONIMPLEMENTATION AND DISSEMINATIONIMPLEMENTATION AND DISSEMINATIONIMPLEMENTATION AND DISSEMINATION

> Disseminate information to the scientific community through the publication of work in peer

reviewed scientific journals, such as Ecological Engineering, Journal of Water and Health,

Journal of Irrigation Management, and Journal of Environmental Management.

> Participate with Water Quality Research Australia (WQRA)2, the University of New South

Wales (UNSW) Water Research Laboratory3 and the Australian Water Recycling Centre of

Excellence (CoE)4 to develop a national validation framework for natural treatment systems

in water recycling.

> Work with the Australian Water Recycling Centre of Excellence to engage with industry to

develop a National Demonstration and Engagement Program that supports successful public

engagement and addresses stakeholder concerns through the provision of contemporary

scientific information on potable water use.

> Develop research linkages with scientists in Australia (UNSW, WQRA, CoE), India (CSIR)

and Germany that characterise natural treatment systems such as water recycling via

aquifers through the European Union 7th Research Framework project Saph Pani “Natural

water systems and treatment technologies to cope with water shortages in urbanised areas

in India”.

> Discuss experiences with colleagues and engage with the broader community through

presentations at conferences, research workshops and community lectures.

2 http://www.wqra.com.au/ 3 http://water.unsw.edu.au/site/ 4 http://www.australianwaterrecycling.com.au/coe/

PPPPROGRAMMEROGRAMMEROGRAMMEROGRAMME: : : : OCTOBEROCTOBEROCTOBEROCTOBER––––NOVENOVENOVENOVEMBER 2010MBER 2010MBER 2010MBER 2010

8–14 OCTOBER UNITED ARAB EMIRATES

7th International Symposium on Managed Aquifer Recharge (ISMAR7), Abu Dhabi

15–23 OCTOBER GERMANY

Kompetenz Zentrum Wasser, Berlin

Umweltbundesamt, Berlin

RECLAIM Water collaborative meeting, Dusseldorf

Saph Pani, work package leader meeting, Frankfurt

24–27 OCTOBER THE NETHERLANDS

Expert Centre for Methodology and Information Services, National Institute of Public Health and the Environment, Bilthoven

28–29 OCTOBER SPAIN

Faculty of Pharmacy, University of Barcelona, Barcelona

30 OCTOBER – 5 NOVEMBER UNITED KINGDOM

Environmental Chemistry, Ecotoxicology and Monitoring Group, Portsmouth University, Portsmouth

6–9 NOVEMBER UNITED STATES OF AMERICA

Civil and Environmental Engineering School, University of California, San Francisco

(A) Abu Dhabi (B) Berlin (C) Dusseldorf (D) Frankfurt (E) Bilthoven (F) Barcelona (G) Portsmouth (H) London San Francisco not shown

WATER WATER WATER WATER SUPPLY & SUPPLY & SUPPLY & SUPPLY & RECYCLING IN AUSTRALRECYCLING IN AUSTRALRECYCLING IN AUSTRALRECYCLING IN AUSTRALIAIAIAIA

With Australia’s growing and increasingly urbanised population, combined with a warming and

drying climate, water security for cities has increasingly become an issue5. Water recycling (of

either stormwater or wastewater) is one potential way to address Australia’s urban water supply

issues. Currently in each Australian capital city the mean urban stormwater runoff volume is

between 85% and 145% of city mains water use and a similarly large portion for wastewater

(Figure 1). Although not all of this can (or should) be captured it does represent a significant

water resource that is close to the city but can be difficult to harvest. Storage is one of the

largest issues associated with water recycling. However, where aquifers are present, water

recycling for non-potable reuse has been implemented effectively via Managed Aquifer

Recharge (MAR)5.

Figure 1: This figure demonstrates the mean annual stormwater runoff in relation to annual mains water consumption and discharge of sewage effluent for Australian mainland capitals. S/M is the ratio of stormwater to mains water which ranges between 85% and 145%6.

To date most Australian capital cities have addressed water security issues by large investment

in seawater desalination plants, the only relatively mature large scale technology implementable

5 NRMMC–EPHC–NHMRC (2009). Australian Guidelines for Water Recycling: Managed Aquifer Recharge (Phase 2), Natural Resource Ministerial Management Council, Environment Protection and Heritage Council and National Health and Medical Research Council, Canberra. www.ephc.gov.au/sites/default/files/WQ_AGWR_GL__Managed_Aquifer_Recharge_Final_200907.pdf 6 PMSEIC Working Group (2007). Water for our cities; building resilience in a climate of uncertainty. Prime Minister's Science, Engineering and Innovation Council Working Group, Canberra.

at the time of need and independent of rainfall. However, seawater desalination is relatively

expensive compared with traditional water supplies from rural catchments and will significantly

increase energy use of capital city water utilities. Other large scale options, such as wastewater

recycling for indirect potable reuse, have suffered from implementation strategies that failed to

adequately address public safety perceptions within a political environment (as in Toowoomba in

2008).

Increasingly, natural systems such as aquifers, wetlands and reservoirs have been recognised

for their water treatment function. To date the adoption of natural treatment systems for

Australian applications in water supply and water recycling is limited as the research on natural

treatment processes continues to evolve. The capabilities of these natural treatment systems

must be validated, as for engineered systems, to ensure risks to human health and the

environment are acceptable. The current level of knowledge of natural treatment systems –

notably in aquifers but also constructed wetlands for stormwater harvesting and detention in

open reservoirs – is not as well developed as in engineered systems.

The systematic accumulation of knowledge about natural treatment systems processes is

expected to provide greater surety of the conditions under which microbial, organic and

inorganic chemical attenuation will occur. Processes and rates of biodegradation or inactivation,

the sustainability of these and their human and environmental health consequences all require

assessment before we can confidently rely on natural systems for water treatment.

NATURAL TREATNATURAL TREATNATURAL TREATNATURAL TREATMENT SYSTEMSMENT SYSTEMSMENT SYSTEMSMENT SYSTEMS

The use of natural systems such as aquifers, wetlands and open storages for water treatment

dates back to antiquity. Since 4000BC water treatment technologies such as straining, filtering

through charcoal, and exposing to sunlight were recorded in Greek and Sanskrit manuscripts.

Fast forward to the early 1800s, slow sand filtration began to be used in Europe, mimicking the

treatment observed to be provided during MAR, mainly to improve water clarity, taste and odour.

In the 1900s intentional bank filtration, by pumping water from wells adjacent to rivers rather

than the rivers or lakes themselves, was employed for some European city water supplies such

as Berlin. Similarly for water recycling, many engineered treatments such as lagoons, trickling

filters and constructed wetlands were designed because of water quality improvements

perceived in the equivalent natural systems where wastes had been discharged. The main

natural treatment systems assessed for water recycling and supply as part of this Churchill

Fellowship were MAR (including bank filtration) and wetland systems (including open storage

reservoirs) and are discussed in the following sections.

MMMMANAGED AQUIFER RECHARGE (ANAGED AQUIFER RECHARGE (ANAGED AQUIFER RECHARGE (ANAGED AQUIFER RECHARGE (MAR)MAR)MAR)MAR)

MAR has been identified as a potential major future water source for Australian cities. MAR

involves adding a water source such as recycled water or stormwater to underground aquifers

during the wet season and recovering under controlled conditions in the dry season (Figure 2).

Figure 2: Aquifer Storage and Recovery (ASR).

MAR is an umbrella term which includes all potential aquifer recharge methods such as ASR

and bank filtration. During MAR there are natural processes that occur, such as filtration and

biodegradation, that are sustainable. For example, the potential for hazards such as pathogens

and organic chemicals such as herbicides present in stormwater or wastewater to be reduced or

oxidised during storage in the subsurface (the ‘redox status’ of the aquifer) has been found to

have a major influence on their rate of degradation. Generally confined aquifers are preferred

targets for storage of water during MAR because the confining layer (Figure 2) provides

protection to groundwater from overlying land use and waste management activities. Generally,

but not always, confined aquifers are anaerobic and only chemicals that are biodegraded under

anaerobic conditions will be degraded.

With stormwater ASR, as is practised in Adelaide, there are extensive periods where there is no

injection of stormwater into the aquifer during the long dry summer season. During this period

strongly reducing conditions will prevail in the aquifer which may be established for long periods

around the injection well. Degradation of known endocrine disrupting compounds (EDCs)

estradiol and nonylphenol has been shown to occur under aerobic conditions. Recent work from

Germany7 has shown that a wider range of EDCs can be degraded under aerobic conditions in

the presence of biodegradable organic carbon as a co-metabolite. Researchers from the

Kompetenz Zentrum Wasser in Berlin have reported the degradation of phenazone (a

pharmaceutically active compound) to occur exclusively under aerobic conditions for a pond

infiltration site near Berlin8.

Another recent research project on bank filtration in Berlin conducted by the Kompetenz Zentrum

Wasser Berlin9, found that the cyanobacterial toxin microcystin degraded readily within the

aquifer in the presence of a substantial biofilm. This supports our own previous studies in South

Australia10 where, in the absence of biofilm, also found degradation of microcystin at a

marginally slower rate. This suggests that biologically active zones on the banks of bank filtration

zones and in close proximity to injection wells support higher rates of biodegradation and

thereby water treatment could potentially be enhanced.

Geochemical processes may also change the composition of the recharged water during MAR.

For example, the presence of pyrite and/or sediment bound organic matter in anaerobic aquifers

can lead to the reduction of nitrate contained in injected water. However, these or other reducing

agents will be successively depleted and the aerobic zone surrounding the injection well will

grow over time11. Under this scenario nitrate removal is not a sustainable process. Furthermore,

those species that are biodegraded under anaerobic conditions only, such as chloroform, may

ultimately become persistent due to the changed redox status of the aquifer.

Pathogen inactivation is also considered in this light and it has been shown that the rate of

inactivation of a number of viruses, protozoa and bacteria, is influenced by the indigenous micro-

organisms present, and that biodiversity of these can be robust. Adsorption is not considered a

7 Massmann, G, Nogeitzig, A, Taute, T, Pekdeger, A (2008). Seasonal and spatial distribution of redox zones during lake bank filtration in Berlin, Germany. Environmental Geology 54(1): 53-65. 8 Greskowiak, J, Prommer, H, Massmann, G, Nützmann, G (2006). Modelling the fate of the pharmaceutical residue phenazone during artificial recharge of groundwater. Environmental Science. & Technology. 40 (21): 6615-6621. 9 Grutzmacher, G, Wessel, G, Klitzke, S and Chorus, I (2010). Microcystin elimination during sediment contact, Environmental Science & Technology, 44 (2), pp 657–662. 10 Dillon, PJ, Miller, M, Fallowfield, H and Hutson, J (2002). The potential of riverbank filtration for drinking water supplies in relation to microcystin removal in brackish aquifers, Journal of Hydrology 266, 3-4, p 209-221. 11 Vanderzalm, JL, Page, DW, Barry, KE and Dillon, PJ (2010). A comparison of the geochemical response to different managed aquifer recharge operations for injection of urban storm water in a carbonate aquifer, Applied Geochemistry, 25, 1350-1360.

sustainable attenuation process as without biodegradation, sorption sites will eventually become

fully occupied and contaminants will break through to recovery wells.

WWWWETLANDS & STORAGE RESERVOIRSETLANDS & STORAGE RESERVOIRSETLANDS & STORAGE RESERVOIRSETLANDS & STORAGE RESERVOIRS

A constructed wetland is an artificial marsh or swamp created to capture and treat wastewater

and urban stormwater runoff. Natural wetlands act as biofilters, removing sediments and

pollutants such as heavy metals from the water. Constructed wetlands can be designed to

emulate these features.

Physical, chemical and biological processes combine in wetlands to remove hazards such as

organic chemicals, nutrients or pathogens (Figure 3).

Figure 3: Constructed wetland treatment processes.

An understanding of wetland treatment processes is fundamental not only to designing wetland

systems but to understanding the fate of nutrients and chemicals once they enter the wetland.

Theoretically, water treatment within a constructed wetland occurs as water passes through the

wetland and the plant rhizosphere. After volatilisation of ammonia and volatile organic

chemicals, sedimentation occurs where aerobic and anaerobic microorganisms facilitate

decomposition of organic matter and release of methane and carbon dioxide. In this way

suspended solids filter out by sedimentation in the water column in surface flow wetlands or are

physically filtered out by the medium within subsurface flow wetland cells. Microbial nitrification

and subsequent denitrification releases nitrogen as gas to the atmosphere. A thin film around

each root hair is aerobic due to the leakage of oxygen from the rhizomes, roots and rootlets

promoting plant uptake of nutrients. Phosphorus is co-precipitated with iron, aluminium and

calcium compounds located in the root bed medium. Pathogens are reduced by filtration and

adsorption by biofilms on the rock media in subsurface flow and vertical flow systems. My own

work has shown that predation by benign bacteria and amoeba has also been shown to be a

factor in the decay of pathogens in constructed wetlands and aquifers12.

The use of constructed wetlands is increasingly being adopted as part of urban stormwater

harvesting systems across Australian capital cities. For example, the Parafield stormwater

harvesting system in Adelaide involves diversion of stormwater to a 50 million litre capacity

capture basin. From there, it is pumped through a similar capacity holding basin from where it

gravitates to a two hectare constructed wetland. My own work has shown that herbicides such

as simazine, atrazine and diuron loads are typically reduced by ~50%13 however, the fates of

these herbicides still remains largely unknown. The system is designed to hold stormwater for

~10 days to ensure optimal treatment efficiency. The current supply capacity of the scheme is

1,100,000 m3/yr. Continuity of supply is achieved by the development of an Aquifer Storage and

Recovery (ASR) system (Figure 2). Two ASR bores (depth 180 m, T2 Aquifer) have been

installed allowing supply when the system has no flow. The recharge water quality has to meet

the Environment Protection Authority (EPA) requirements.

12 Sidhu, JP, Toze, S, Hodgers, L, Shackelton, M, Barry, K, Page, D, and Dillon, P (2010). Pathogen inactivation during passage of stormwater through a constructed reedbed and aquifer transfer, storage and recovery, Water Science and Technology, 62, 5, 1190-1197. 13 Page, D, Dillon, P, Mueller, J and Bartkow, M (2010). Quantification of herbicide removals in a constructed wetland using composite water quality monitoring and passive samplers, Chemosphere, 81, 394-399.

WWWWHY TRAVELHY TRAVELHY TRAVELHY TRAVEL TOTOTOTO THE THE THE THE MIDDLE EAST,MIDDLE EAST,MIDDLE EAST,MIDDLE EAST, EUROPE &EUROPE &EUROPE &EUROPE & THETHETHETHE USA USA USA USA????

When assessing natural treatment systems for Australian applications to water supply and water

recycling, there are a number of international institutions and researchers who have developed

new methods in the area. These include:

> Managed Aquifer Recharge (MAR) The 7th International Symposium on Managed Aquifer

Recharge (ISMAR) is the world’s preeminent conference devoted entirely to aquifer recharge.

Held in Abu Dhabi, United Arab Emirates, in October 2010 the symposium brought together

many of the world’s experts on Managed Aquifer Recharge (MAR). The conference included

workshops and three days of technical sessions.

> Bank filtration Germany has led the world with its revolutionary “Mulheim Process” – a bank

filtration process first trialled on the River Rhine. Bank filtration currently is used to treat the

Berlin water supply.

> Wetlands In assessing the removal of organic chemicals in wetlands, Prof Graham Mill’s

research group in Portsmouth University, UK is the world’s leader in the development,

evaluation and optimisation of passive sampling procedures and technologies for the

monitoring of trace-levels organic chemicals in water.

> Reservoirs Prof David Sedlak’s research group at the University of California, Berkley have

made large advances in understanding the transformation of organic chemicals from

reclaimed wastewater in engineered wetlands and open storages. In particular the adoption of

process-based studies.

My main findings and learning from each country are described in the following sections.

UNITED ARAB EMIRATESUNITED ARAB EMIRATESUNITED ARAB EMIRATESUNITED ARAB EMIRATES

The International Symposium on Managed Aquifer Recharge (ISMAR) conference series began

in August 1988 in Anaheim, California as the 1st International Symposium on Artificial Recharge

of Ground Water. Pioneered by the American Society of Civil Engineers (ASCE), it continued in

Orlando, Florida (1994) before the International Association of Hydrogeologists (IAH) partnered

ASCE in Amsterdam (1998). Following the 4th Symposium in Adelaide (2002) the name changed

to International Symposium on Managed Aquifer Recharge to reflect the growing scientific basis

supporting overt management of quantity and quality of recharge, and reflected the name of the

IAH Commission on MAR, which was established in 2002. ASCE has also adopted this name for

its relevant standards committee. Dedicated to a global reach, recent ISMAR conferences have

been ISMAR 5 (Berlin, Germany 2005) and ISMAR 6 (Phoenix, USA 2007). ISMAR 7 was held

in Abu Dhabi, UAE from October 9-13 2010.

The symposium continues as a joint venture of IAH/ASCE and is the prime international meeting

in this field, adopting the Commission’s aims to “expand water resources and improve water

quality in ways that are appropriate, environmentally sustainable, technically viable, economical,

and socially desirable. It will do this by encouraging development and adoption of improved

practices for management of aquifer recharge." (IAH, January 2002)

The symposium brought together 320 delegates from 51 countries to showcase research and

further understanding on MAR. The symposium included four workshops, fourteen themed

technical sessions including a poster paper session each day, and a full day field tour of the

Strategic Water Reserve Project - Liwa. Talks were given by speakers from countries in Europe

(Germany, Spain, France, The Netherlands, England and Finland), the Middle East (Bahrain,

United Arab Emirates), Africa (South Africa), Asia (India and Malaysia), Central America

(Mexico), United States of America and Australia, covering a diverse range of MAR topics

including hydraulics and storage, the role of integrated water management, regulations,

economics, geochemistry, the fate of pathogens and organic compounds, regional issues, basin

recharge, subsurface water quality changes, and operational and management issues.

I attended the UNESCO workshop on “Where is MAR the best option for securing drinking water

supplies, and how?” Dr Albert Tuinhoff from the Acacia Water Institute (University of

Amsterdam) gave an excellent presentation on the 3 R’s (Recharge, Retention and Reuse) for

water quality improvements14 as well as other infiltration technologies15 to meet the United

Nations Millennium development goal “Water as a Right” and stressed the need for better

economic analysis of MAR options. To date the World Development Bank had not yet

considered MAR on a wider scale as the economics were poorly documented for existing

projects. Dr Peter Dillon from CSIRO Land and Water, Australia presented on the newly formed

international body MAR-NET which was supported by IAH and UNESCO. The final workshop

speaker, Dr Ian Gale, from the British Geological Survey ended with case examples of MAR in

India but said, to date, the technology had not been widely adopted due to the lack of

international demonstration sites and poor integration with regional water management plans.

14 www.bebuffered.com 15 www.igrac.nl

The opening address by Schlumberger Water Services16 (the organiser of the symposium)

included a sobering reminder of the water scarcity faced by the world17 (Figure 4) and the

potential for water recycling via aquifers to be used as tool for water resource management.

Figure 4: Many basins are subject to water scarcity and there are two types of water scarcity identified by IWMI: physical and economic.

The keynote speech by Gary Amy, director of the Water Desalination Research Centre and

Professor of Environmental Engineering at the King Abdullah University of Science and

Technology (KAUST) in Jeddah, Saudi Arabia focussed on the use of MAR as a robust

treatment technology. His presentation was outstanding and highlighted the advantages and

potential for MAR to attenuate pathogens and organic chemicals.

I gave a platform presentation entitled “Quantitative Microbial Risk Assessment to determine

pathogen risks for a Managed Aquifer Recharge Project” (Figure 5) which was also published by

the Journal Water Research18.

16 http://www.slb.com/services/additional/water.aspx 17 http://www.iwmi.cgiar.org/About_IWMI/Strategic_Documents/Annual_Reports/2006_2007/theme1.html 18 Toze, S., Bekele, E., Page, D., Sidhu, J. and Shackleton, M. (2010) Use of static Quantitative Microbial Risk Assessment to determine pathogen risks in an unconfined carbonate aquifer used for Managed Aquifer Recharge, Water Research, 44, 1038-1049.

Figure 5: Platform presentation at ISMAR7.

My presentation focussed on the use of a structured approach to MAR system design to quantify

aquifer treatment using advanced statistical techniques in a case study site from Perth. My

presentation was very well received and led to an invite to lead a work package as part of a

European Union research proposal with researchers in India and Europe through the Saph Pani

project.

A key theme of ISMAR7 was the economics of MAR and an excellent presentation was given by

David Pyne of ASR Systems19, USA a pioneer of ASR technology. Through economic analysis

David Pyne demonstrated that ASR had costs of ~$0.32 / kL and was potentially a very cost

effective methodology for water supply (compared to, for example, $1.26 / kL for mains

reticulated water supply in South Australia). Similarly, in comparison to other supply options,

ASR is more cost effective at around 30-46% of desalination costs (as used both in the United

Arab Emirates and increasingly Australia), 1-4% of storage costs (compared to above ground

constructed tanks) and uses only 3% of the energy of desalination. Clearly ASR will become

increasingly attractive if a carbon tax is introduced in Australia.

Dr Gesche Grützmächer from Kompetenz Zentrum Wasser20, Berlin gave an overview of MAR

research needs in Europe which provided an excellent basis for my Fellowship. Dr Grützmächer

also invited me to give a presentation to her research group in Berlin the same week.

19 http://www.asrsystems.ws/ 20 http://www.kompetenz-wasser.de/

GGGGERMANYERMANYERMANYERMANY

German researchers have extensive experience in the evaluation of bank filtration7 and

managed aquifer recharge 8, 9.

BBBBERLINERLINERLINERLIN

Since my second week abroad was based in Berlin, I was able to visit Dr Gesche Grützmächer

from the Kompetenz Zentrum Wasser20 Berlin. I gave a presentation in German to an audience

of approximately a dozen researchers on the experience CSIRO has had with aquifer recharge

and in assessing natural treatment systems. We discussed the WELLMA2 project21 which

investigates the capacity of drinking water wells, i.e. the yield for a given drawdown, which is

found to often decrease after a certain time of operation. This effect is called well ageing and is

due to different processes related to the geology and hydrochemistry at any given well site and

to the construction and operation of these wells. To avoid impacts on water quantity and quality

and to ensure the economic efficiency of well operation, the pump dimensioning, water

quantities, operation times, and the maintenance intervals and methods must be planned

according to the characteristic features of each well depending on (i) site conditions, (ii) well

performance and (iii) cost-benefit analysis. Based on the evaluation of the current best practice

in well characterisation WELLMA1, the second phase of the project includes investigation of the

ageing behaviour of wells in Berlin and France to determine suitable measures to help slow

down well ageing processes and optimise strategies for well operation and maintenance.

After the presentation I was fortunate to be invited to the commissioning of an ozone treatment

plant at the infiltration ponds at Lake Tegel, the main water supply for the city of Berlin. At this

research site river bank filtration and artificial groundwater recharge are used as effective

barriers for organic chemicals and pathogens present in Lake Tegel waters during drinking water

production. However, there are limitations concerning the removal of dissolved organic carbon

(DOC) and some specific trace organics such as phenozone. The ozone treatment plant and

research project aimed to assess possibilities to overcome these limitations by combining

underground passage and ozonation as pre- or post-treatment.

During this first phase of the research at the ozonation plant, existing data on underground

removal of organic chemicals is still being evaluated in order to identify priority substances that

should be targeted in future investigations. The first phase is also complimented by laboratory

column tests in order to quantify removal of these organic chemicals under varying conditions. I

believe Australia can learn from the experiences of a country which has proven the use of

natural treatment systems such as bank filtration to improve water quality.

21 http://www.kompetenz-wasser.de/WellMa2.494.0.html?&L=1

While in Berlin I also had the opportunity to visit Umweltbundesamt (UBA)22 the German Federal

Environmental Protection Agency’s field station in Berlin-Marienfelde. Dr Sondra Klitske guided

me through the artificial stream and pond system (“Fließ- und Stillgewässer-Simulationsanlage”

– FSA)23. Its facilities comprise 16 streams of 1.6 km in total length, 16 ponds, approximately 5

km of pipe network equipped with more than 60 pumps, 360 valves and appropriate technical

measuring equipment. The test plant allows the simulation of aquatic lotic (flowing), lentic

(stagnant) and flow-through systems – from streams and rivers, ponds and lakes, right up to

river like lakes. The FSA is one of the largest existing mesocosm systems internationally. It

provides an intermediary between easily controllable, but simplifying, laboratory experiments

and field studies, which are less controllable but more realistic compared to the field situation.

One objective of mesocosm experiments is to examine the effects of organic chemicals such as

atrazine (also widely present in stormwater runoff from Australian urban centres) and pathogens,

which are selectively introduced into the systems. The substances can either be introduced into

surface waters by treated municipal wastewater (e.g. pharmaceuticals, substances containing

hormones, detergents and cleansing agents, industrial chemicals, bacteria, viruses, etc) by

runoff from rural areas (e.g. pesticides) or as the result of industrial accidents or atmospheric

deposition (e.g. industrial chemicals).

The Berlin researchers found bank filtration to be an important, effective and operationally cheap

technique for surface water treatment and removal of pathogens, as well as inorganic and some

organic contaminants. Nevertheless, physical, chemical and biological processes of the removal

of impurities are not understood sufficiently. A research project titled Natural and Artificial

Systems for Recharge and Infiltration (NASRI)24 with KWB, FUB and UBA as research partners

attempted to provide more clarity in the processes affecting the removal of these contaminants.

The project focused on the fate and transport of selected emerging contaminants during bank

filtration. Several detections of pharmaceutically active compounds in ground water samples

from bank filtration sites in Germany led to furthering research on the removal of these

compounds during bank filtration. Six compounds including the analgesic drugs diclofenac and

propyphenazone, the antiepileptic drugs carbamazepine and primidone, and the drug

metabolites clofibric acid and 1-acetyl-1-methyl-2-dimethyl-oxamoyl-2-phenylhydrazide were

found to leach from the contaminated streams and lakes into the ground water. These

compounds were also detected at low concentrations in receiving public supply wells. Bank

filtration either decreased the concentrations by dilution (e.g. for carbamazepine and primidone)

and partial removal (e.g. for diclofenac) or totally removed the compounds (e.g. bezafibrate,

22 http://www.umweltbundesamt.de/index-e.htm 23 http://www.umweltbundesamt.de/wasser-und-gewaesserschutz-e/fsa/index.htm 24 http://www.kompetenz-wasser.de/IC-NASRI-Integration-and-Consolid.407.0.html?&L=1

indomethacine, antibiotics and estrogens). Several compounds, such as carbamazepine and

especially primidone, were readily transported during bank filtration. They were recommended to

me as good indicators for evaluating whether surface water is impacted by contamination from

municipal sewage effluent or whether contamination associated with wastewater can be

transported into ground water at ground water recharge sites.

Dr Klitske invited me to give a presentation at the Umweltbundesamt offices of my own

research25 on risk-based assessment of MAR projects. We discussed the validation of natural

treatment processes during managed aquifer recharge and water recycling in Australia. Several

of the researchers from the Hydrogeology Workgroup26 of the Free University of Berlin were also

present including Professor Schneider26, a world leader in bank filtration hydrogeology.

The work of the Berlin researchers has confirmed my own ideas that, to date, the processes that

occur in natural treatment systems such as wetlands and aquifers are not as well understood as

engineered systems and as such adoption of these natural technologies has been limited. This

is especially true at large city scales such as the Berlin drinking water supply. In Australia

implementation has been limited due to the high requirements for detailed planning and

investigation phases at the beginning of each project. However, very recent research in South

Australia showed the potential of such systems. The Aquifer Storage Transfer Recovery (ASTR)

project27 demonstrated that urban stormwater, treated in the Parafield stormwater harvesting

system, then injected into an aquifer could be recovered at a potable quality. After extensive

testing to show that the water met drinking water standards, a bulk sample was taken for bottling

and distributed to the Australian Prime Minister’s Science Engineering and Innovation Council in

June 2007 as bottled drinking water. The sample best represents the quality of water intended to

be recovered on an ongoing basis from the ASTR project when the aquifer has been flushed.

This project was part of the RECLAIM Water European Community project and introduces

stormwater as the water to be recovered and an ASTR system as the means of storing and

recovering water in the aquifer.

DDDDUSSELDORFUSSELDORFUSSELDORFUSSELDORF AND FRANKFURT AND FRANKFURT AND FRANKFURT AND FRANKFURT

In Dusseldorf I visited Dr Christian Katzner, team leader of water research and chair of chemical

process engineering at the RWTH Aachen University. Luckily, Dr Thomas Wintgens of the

Institut für Ecopreneurship, University of Applied Science, Switzerland was also able to meet me

25 Page, D, Dillon, P, Vanderzalm, J, Toze, S, Sidhu, J, Barry, K, Levett, K, Kremer, S and Regel, R (2010). Risk assessment of Aquifer Storage Transfer and Recovery with urban stormwater for producing water of a potable quality, Journal of Environmental Quality, doi:10.2134/jeq2010.0078. 26 http://www.geo.fu-berlin.de/en/geol/fachrichtungen/geochemhydromin/hydrogeologie/index.html 27 http://www.clw.csiro.au/research/urban/reuse/projects/ASTRbrochure.pdf

briefly in Frankfurt. Dr Kazner and Dr Wintgens had recently been involved in the RECLAIM

WATER project, of which my own research at the ASTR site was linked. The RECLAIM WATER

project was a Specific Targeted Research Project supported by the European Commission

under Thematic Priority 'Global Change and Ecosystems' of the Sixth Framework Programme

(Contract-No. 018309). RECLAIM WATER was a research project to provide effective

technologies to monitor and mitigate emerging risks posed by organic chemicals and pathogens

in reclaimed wastewater used for groundwater recharge. It integrated engineering water

reclamation solutions with natural attenuation processes occurring in aquifers to achieve

upgraded water quality assessed on the basis of key contaminants. The project related directly

the knowledge obtained on new treatment processes and contaminant behaviour to the question

of risk associated to the indicated use.

In Frankfurt I was invited to join a research group meeting to contribute my expertise in public

health risk assessment for natural systems. A new European Commission research project Saph

Pani28 is being developed to address water shortages in Indian urban centres with natural

treatment systems including bank filtration, wetlands and MAR. I offered to twin some of our

research sites such as the ASTR project28 with Indian case study sites that had complimentary

research objectives. As a result of these discussions I was included as a key researcher in Work

Package 6 “integrated sustainable systems” and have further linked this work to my own

international water supply and development activities in India funded by AusAid which are due to

begin in January 2011. This has given me the opportunity to participate in an ongoing research

effort with world class scientists from Europe and work on the United Nations millennium

development goals, and hence I am able to bring the benefit of my knowledge not just to

Australia, but also to other less economically developed countries around the world.

THETHETHETHE NNNNETHERLANDSETHERLANDSETHERLANDSETHERLANDS

During my time in the Netherlands I had the opportunity to visit the Amsterdam Water Supply

Dunes, one of the largest dune areas in the Netherlands of which a large part is used for the

collection of drinking water for Amsterdam. The drinking water in Amsterdam is taken from the

river Rhine and infiltrated through the dunes (again a form of MAR) near Zandvoort.

The Zandvoort dunes have a considerable landscape variety (from open sand to woodland) and

a rich flora and fauna. The area is also open to the public for hiking; therefore, this area is a

unique opportunity for nature lovers to explore this typical Dutch landscape. Amsterdam tap

water has been rated in the top three across Europe since tests started in 1997. Waternet, the

Amsterdam water supply utility, also provides tap water in neighbouring towns like Amstelveen, 28 The Hindi word for “clean water”

Diemen, Heemstede, Muiden and Ouder-Amstel. Unlike Australia, the water is not disinfected

with chlorine possible only due to the low temperature of the water distribution system and the

functioning of the dune infiltration system. It is often said that this tap water is even healthier

than mineral water you can buy in the supermarket. The reason that the tap water is of this high

quality is that Waternet has utilised both engineered and natural treatment systems such as slow

sand filtration and constantly invests in the latest technology. Waternet also invests in

international efforts to improve the quality of the water in the river Rhine.

I also had the opportunity to visit Dr Jack Schijven of the National Institute of Public Health

(RIVM) and the Environment, Microbiological Laboratory for Health Protection in Bilthoven.

RIVM is a recognised leading centre of expertise in the fields of health, nutrition and

environmental protection. They work mainly for the Dutch government but also are very active in

water quality research around the world. The results of their research, monitoring, modelling and

risk assessment are used to underpin policy on public health, food, safety and the environment.

They have over 1,500 employees, many of whom work in multidisciplinary fields.

Dr Schijven is an Adjunct Associate Professor in the Department of Earth Sciences at Utrecht

University and Senior Consultant at the Expertise Centre for Methodology and Information

Services of RIVM (National Institute for Public Health and the Environment) in The Netherlands.

He is one of the European experts on MAR and has extensive experience on virus transport in

porous media at field and laboratory scales. We share a common research interest in developing

methods in Quantitative Microbial Risk Assessment (QMRA) to measure risk from pathogens in

drinking water to human health. The use of QMRA to characterise natural treatment systems

allows the effects of these treatment systems to be determined and the effect on population

disease burden expressed. Importantly, from my perspective, a default assumption of 0.01

log10/day decay is used for viruses in the aquifer during a QMRA. This is an important

assumption and I will utilise it in my own work where decay rates in aquifers are not know.

In addition to a long discussion on QMRA applications in the Netherlands for drinking water

supply, I found it particularly interesting that Prof Schijven had used Derjaguin-Landau Verwey-

Overbeek (DLVO) theory. DLVO theory29 describes the force between charged surfaces

interacting through a liquid medium. It combines the effects of the van der Waals attraction and

the electrostatic repulsion due to the so called double layer of counter ions. The electrostatic part

of the DLVO interaction is computed in the mean field approximation in the limit of low surface

potentials – that is when the potential energy of an elementary charge on the surface is much

smaller than the thermal energy scale, kBT. DLVO can be applied in determining colloid

29 http://en.wikipedia.org/wiki/DLVO_theory

transport in porous media and also interestingly utilised to assess virus transport (a form of

charged particle) in aquifers (a porous media). I have done some similar work with DLVO but

only using kaolin particles in roughing filters. Of most interest was the use of a number of default

assumptions including a virus stickiness factor, often also termed the single collector efficiency,

α = 10-5. This stickiness factor is a ratio of total collisions of a virus to sand grains in the aquifer

to the number that result in the virus sticking. The more sticky the virus the less likely it will be

transported long distances and hence the better the natural treatment systems such as aquifers.

The virus stickiness depends upon a number of factors including the virus charge, ionic strength

of the aqueous solution, charge of minerals in the aquifer matrix and pH. For limestone MAR

systems that we are using in Australia, with high pH, viruses are quite mobile which highlights

the importance of this work in the Australian context. The meeting with Prof Schijven also

highlighted the growing importance of soft particle theory in understanding virus transport in

aquifers, something that I will investigate further in Australia.

SSSSPAINPAINPAINPAIN

I spent a single day in Barcelona, to visit staff of the Unitat d'Edafologia, Facultat de Farmàcia at

the University of Barcelona. I worked with PhD student, Ms Neus Ayuso-Gabella and her

supervisor Dr Miguel Salgot to evaluate the human health risks (using QMRA) for treated

wastewater used to irrigate hospital green public spaces. We worked on a series of MAR sites

used internationally for water recycling via aquifers which were part of the RECLAIM WATER

project. The risk studies cover water intake, treatment, storage and distribution steps, analytical

tools, monitoring and control systems, and operational procedures as well as communication

procedures.

We developed a coherent application of these elements for the case studies that covered non-

potable reuse practices which will result in a joint author research manuscript to the Journal of

Irrigation Water Management as well as a chapter in a new book soon to be published by the

International Water Association named “Advances in Water Reclamation Technologies for Safe

Managed Aquifer Recharge”30 a part of the European Water Research Series31. Both

publications will focus on my previous QMRA work from Australia as well as the discussions

from Germany and the Netherlands resulting in estimations of the human health disease

burdens for a number of sites. The research manuscript and book chapter are both clear

outcomes of the Churchill Fellowship that will be recorded in the scientific literature and available

as a reference for scientists in Australia and abroad.

30 http://www.iwapublishing.com/template.cfm?name=isbn9781843393443 31 http://www.iwapublishing.com/template.cfm?name=bookseries&series=eu_report_series

UUUUNITED KINGDOMNITED KINGDOMNITED KINGDOMNITED KINGDOM

While in the United Kingdom I visited the Winston Churchill Memorial Trust head office. It was

amazing to hear about the diversity of projects undertaken by UK Fellows and learn of the

immense impact these experiences have had.

My main objective in the United Kingdom was to visit Dr Graham Mills, a Reader in

Environmental Chemistry at the School of Pharmacy and Biomedical Sciences at the University

of Portsmouth. His research group’s main activities are focused on the development, evaluation

and optimisation of passive sampling procedures and technologies for the monitoring of trace-

levels of organic chemicals in water. Passive sampling involves the deployment in-situ of

devices that are capable of accumulating dissolved contaminants from the water phase over

extended periods of time. Following an exposure, the samplers are retrieved and the

contaminants accumulated in the receiving phase are eluted and their concentration levels

measured.

There is an increasing requirement for the monitoring of water quality across Europe, with

particular emphasis on the contaminants in the list of Priority Pollutants. The frequency of

sampling required by the various water quality directives (e.g. Dangerous Substances Directive

76/464/EEC and daughter directives; Methods of Measurement, Sampling and Analysis of

Surface Waters Directive 79/869/EEC) and other international agreements varies enormously,

with little harmonisation between them. However, the only methodology that is currently

accepted is that of grab sampling. This gives only a snapshot of water quality at the moment of

sampling and can be misleading where levels of pollutants fluctuate such as in stormwater.

Passive sampling can provide low-cost, time-averaged measurements of concentrations of

organic chemicals, and hence overcome the problems associated with grab sampling. However,

currently, passive sampling is not recognised by legislators because of a lack of a standardised

approach for the application of this technology. There are no formal standards defining this

methodology and this precludes acceptance for legislative purposes.

Currently available passive samplers (e.g. the ChemCatcher™) cannot effectively monitor all of

the organic chemicals of concern to water supply and water recycling. If this problem is not

resolved, the extra sampling required by developing legislation will place a large financial burden

on water recycling projects potentially making them economically unviable.

My own research in natural treatment systems such as the removal efficiency of organic

chemicals in the Parafield stormwater harvesting system wetland also used the ChemCatcher™

sampler to measure levels of polar pesticides13 such as simazine, atrazine and diuron. Prof Mills

and I discussed their application to MAR and the use of observation wells and sampling and

experimental design to monitor and assess risk for the ASTR sequel project due to begin in

2011. The design of sampling and monitoring programs for assessing aquifer systems was the

main topic of discussion and I will immediately be able to apply the knowledge in a new MAR

Stormwater Use Options project currently under development as a key project for the newly

formed Goyder Water Research Institute32 in South Australia. I will apply for a further opportunity

to work for a longer period in his laboratory as a result of our discussions.

UNITED STATES OF AMERICAUNITED STATES OF AMERICAUNITED STATES OF AMERICAUNITED STATES OF AMERICA

Much like in Australia, throughout the dryer parts of the USA a significant fraction of the flow of

many rivers consists of municipal wastewater effluent. The discharge of large volumes of

wastewater (e.g. the Murray River in Australia) can result in the exposure of humans and aquatic

organisms to a variety of different wastewater-derived contaminants including several

32 http://www.waterforgood.sa.gov.au/2010/05/research-hub-secures-sas-water-future/

While in London I also made a personal pilgrimage to visit a plaque commemorating John Snow. John Snow (1813-1858) was a British physician and is considered to be one of the fathers of epidemiology, because of his work in tracing the source of a cholera outbreak in Soho, London. In 1854 Snow was a sceptic of the then dominant miasma theory which considered that diseases such as cholera or the Black Death were caused by pollution or a noxious form of "bad air". Concepts such as pathogens and their effects on public health was not to be developed until 1861, so he was unaware of the mechanism by which the disease was transmitted, but evidence led him to believe that it was not due to breathing foul air. By talking to local residents he identified the source of the outbreak as the public water pump on Broad Street (now Broadwick Street). Although Snow's chemical and microscope examination of a sample of the Broad Street pump water was not able to conclusively prove its danger, his studies of the pattern of the disease were convincing enough to persuade the local council to disable the well pump by removing its handle. Although this action has been commonly reported as ending the outbreak, the epidemic may have already been in rapid decline, as explained by Snow himself: “... There is no doubt that the mortality was much diminished, as I said before, by the flight of the population, which commenced soon after the outbreak; but the attacks had so far diminished before the use of the water was stopped, that it is impossible to decide whether the well still contained the cholera poison in an active state, or whether, from some cause, the water had become free from it.” Snow later used a spot map to illustrate how cases of cholera clustered around the pump. He also made a solid use of statistics to illustrate the connection between the quality of the source of water and cholera cases. He showed that the Southwark and Vauxhall Waterworks Company was taking water from sewage-polluted sections of the Thames and delivering the water to homes with an increased incidence of cholera. Snow's study1 was a major event in the history of public health, and geography, and can be regarded as the founding event of the science of epidemiology. John Snow was voted in a poll of British doctors in 2003 as the greatest physician of all time. The water pump with its handle removed is near what is now "The John Snow" public house, which is rather ironic, given that Snow was a teetotaller for the majority of his life.

carcinogens and endocrine-disrupting compounds. For example, the drinking water supply of

some communities is taken from rivers that are subjected to significant upstream wastewater

effluent discharges (e.g. Cincinnati’s drinking water intake is located on the Ohio River

downstream of Pittsburgh’s wastewater effluent discharge point) and wastewater effluent

frequently contains elevated concentrations of carcinogenic disinfection by-products, such as

nitrosodimethylamine. Many of the wastewater-derived organic chemicals are removed as they

pass through surface waters through a combination of chemical, biological and physical

processes. At present, little information is available on the factors determining the rates at which

these compounds are removed in natural systems or which mechanisms dominate.

I visited the University of California, Berkley campus where I met with Prof David Sedlak33 at the

Department of Civil and Environmental Engineering. Prof Sedlak is a global expert on the

organic chemical contamination of water supplies, He developed some of the first reliable

methods for measuring steroid hormones (endocrine disruptors) in treated effluent. His findings

became internationally acclaimed a decade later when other scientists began linking these

steroids in the water to the feminisation of wildlife. Since then he has found and tracked other

human-eliminated pharmaceuticals and personal care products which are not eliminated by the

conventional wastewater treatment process.

Prof Sedlak and I discussed specific research conducted by members of his group which

focused on the different mechanisms through which organic chemicals are removed from the

aquatic environment. For example, a study using solar-simulator (a type of lamp which simulates

the same wavelengths as the sun) was able to quantify the mechanisms and pathways of

organic chemical removal by exposure to sunlight. Myself and other scientists at CSIRO plan to

purchase a similar piece of equipment in 2011 so it was invaluable to see how it was operated

and discuss its use for our future microcosm experiments in Australia. These discussions have

been invaluable in experimental design and will allow us to undertake targeted experiments

which will maximise the information gained in determining how organic chemicals degrade

during MAR and also wetland treatment.

Prof Sedlak was also investigating urban concentrations of PFOA (perfluorooctanoic acid, also

known as C8), which was released by a nearby Teflon manufacturing facility. This compound

and other similar ones have a very high stability in the environment which has both contributed

to their utility as surface treatments (such as Teflon) and to their persistence in the natural

environment (they don’t degrade under normal environmental conditions). PFOA have been

detected at parts-per-billion levels (ppb) in animal tissue and environmental waters and

33 http://www.ce.berkeley.edu/~sedlak/

sediments worldwide. Research has also shown them to bio-accumulate in the tissues of fish

and mammals. That is, they tend to persist in the tissues of animals at higher levels than found

in the environment. The bio-accumulation has triggered much of the recent health concern

regarding these chemicals. Environmental stability and bioaccumulation, alone, do not indicate a

health risk but they do indicate that a concern for long-term exposure exists. PFOA can form

from the degradation of precursors such as Teflon in addition to industrial production. The

research has indicated it is widely distributed in stormwater and she developed a novel new

method to evaluate environmental concentrations. To date there have been no similar studies to

my knowledge in Australia.

As a result of these discussions I was able to obtain Prof Sedlak’s counsel on experimental

design for monitoring open reservoir and wetland systems and will apply this knowledge in

Australia for the Urban Water Security Research Alliance34. This research alliance was formed to

address south east Queensland's emerging urban water issues. It is a $50 million partnership

over 5 years between CSIRO, Queensland Universities and the Queensland government. As the

largest urban water research program in Australia, the Urban Water Security Research Alliance

has a focus on water security and recycling and is involved in new research tailored to tackling

existing and anticipated future risks, assumptions and uncertainties facing water supply strategy.

By having the opportunity to travel to the USA, my own scientific method has been greatly

enhanced and several enduring linkages have been developed that will be of value for the

Australian community in assessing the application of natural treatment systems to water supply

and water recycling.

34 http://www.urbanwateralliance.org.au/

CONCLUSIONSCONCLUSIONSCONCLUSIONSCONCLUSIONS & RECOMMENDATIONS & RECOMMENDATIONS & RECOMMENDATIONS & RECOMMENDATIONS

The Winston Churchill Trust Fellowship has provided me with the opportunity to follow my

passion for good science. I feel honoured to have been selected by the SA Churchill selection

committee to assess natural treatment systems for Australian applications in water supply and

water recycling. I have gained enormous personal and professional gratification from travelling,

working and collaborating with international researchers who are passionate and enthusiastic

about this topic. My understanding and appreciation of international approaches to water

recycling and reuse has grown exponentially, with thanks to the generosity of the Winston

Churchill Fellowship.

The following recommendations result from research, discussion and observation conducted

during my Fellowship:

> There is a need for greater awareness by local, state and federal governments of the diverse

range of potential uses of natural treatment systems. Natural resources management

agencies should consider water recycling via natural systems as they have great benefits not

only in terms of water treatment but also public acceptance.

> Increased familiarity of natural systems within utilities and state agencies is required, which

will lead to improved implementation and governance. This can be encouraged by

establishing, in each state, at least one demonstration project for each natural system

technology and other pioneering projects involving partnerships between state stakeholders.

This would provide stakeholders experience with investigations, design, approvals,

commissioning and operation, including testing water recovery for drinking water supplies.

These demonstration sites would also provide an excellent resource for research, training and

evaluation, trialling of investigation methods, planning and governance arrangements, and

raising general awareness.

> More research on attenuation rates of organic chemicals in aquifers and wetlands is required.

A project to produce first basic information and models is required to more generally underpin

validation of these systems. Further information can be obtained from validation monitoring

and research should be made publicly available. Standardised methods are required for

measuring in-situ attenuation rates in aquifers so that data is directly comparable.

> Research is required to demonstrate sustainable water recycling via aquifers for drinking

water quality for MAR sourced by urban stormwater and treated sewage effluent. Research is

also warranted to establish bank filtration projects for towns whose run-of-river drinking

supplies will be less reliable as a result of climate change. Effects of mixing of recovered

water with other sources of water of drinking water quality and integrating infrastructure also

warrant evaluation at demonstration sites.