Methods to increase the use of recycled wastewater in irrigation by overcoming the constraint of soil salinity
Continuity of water supply is an ongoing concern for many South Australian irrigation districts. For those in close proximity to urban centres, the use of recycled municipal wastewater offers improved security of supply with the added environmental benefits of reduced marine discharge and the easing of demand upon more traditional irrigation water sources. There is also an economic benefit from the lower cost of water and the reduced need of fertiliser. South Australia already recycles more than 30% of its treated wastewater and seeks to increase reuse via irrigated horticulture and amenity plantings in support of the State’s strategic priority of ‘Clean green food as our competitive edge’. However, recycled wastewater can be slightly more saline than traditional water sources. Its incorrect use in irrigated crop production can increase soil salinity, raise the concentrations of sodium and chloride ions in leaves and fruit and reduce crop performance more than other irrigation water sources.
This collaborative project, funded by The Australian Water Recycling Centre of Excellence (AWRCOE) and the Goyder Institute for Water Research, was initiated to investigate two strategies aimed at supporting the sustainable use of recycled wastewater in irrigated crop production by addressing the constraint of salinity. The project focussed on Australia’s two most valuable horticultural export products, almonds and wine, both sourced from cropping systems recognised as being moderately sensitive to soil salinity and both industries with significant plantings located within recycled wastewater irrigation districts.
The project established two field trials north and south of Adelaide, where some cropping systems, with a relatively short history of irrigating with recycled wastewater, had already reported salinity related impediments to production. Investigations focussed on a vineyard in McLaren Vale and an almond orchard on the Northern Adelaide Plains (NAP).
At the McLaren Vale vineyard, treatments consisted of installing various configurations of rainfall re-direction devices, drawing from a body of work on approaches used to enhance run-off during water harvesting, to increase leaching under supplementary irrigation conditions. In the NAP almond orchard, irrigation was historically supplied by shandying dual water sources of different qualities, recycled wastewater and groundwater. Treatments sought to temporally separate irrigation with the two water sources in order to identify in which annual growth stage trees were most sensitive to the slightly saline recycled wastewater. Treatment effects at both sites were assessed by measurement of soil salinity and moisture, salt concentrations in leaves and fruit, yield and vegetative growth.
The primary aim of this project was to improve the management of salinity in permanent horticultural plantings which receive supplementary precision irrigation with recycled water. Specific objectives were:
The methodology and guidelines developed in this project have supported both the long-term use of recycled water for a range of irrigated crops as well as supported amenity plantings by councils. The outcomes of this research have benefitted both traditional irrigators as well as informed the state’s recycling guidelines (for both urban and rural communities) and have contributed to recycled water irrigation practices across tAustralia.
Chris Wright holds significant experience in public sector senior leadership, having led policy, scientific and operational business units over the last twelve years in both State and Commonwealth government agencies. Chris has excellent experiences in leading policy and strategy formulation. He is skilled in building and maintaining networks across the public and private sectors to facilitate business delivery; leading and negotiating with others to achieve outcomes; and in bridging the science-policy gap, drawing on earlier roles in geospatial information systems (GIS) consulting. Chris’s formal qualifications include a Bachelor of Social Science, a Masters of Spatial Information Science and graduation from the AICD Company Directors course in 2019.
Dr Ilka Wallis is a hydrogeologist with areas of expertise in quantitative hydrogeology and geochemistry. Ilka focuses on the development of reactive geochemical transport models which integrate fundamental processes that are normally studied in isolation (hydrogeological, mineralogical, geochemical and biochemical).
Ilka is also an Adjunct Professor, Department of Civil Engineering, University of Manitoba, Canada since 2017.
Peter Goonan is the Principal Aquatic Biologist in the Environmental Science Branch of the EPA. He has over 30 years’ experience monitoring the condition of aquatic ecosystems in SA and assessing the environmental effects caused by discharges, deposits and contaminants entering inland and coastal waters. He specialises in aquatic invertebrate identification and their responses to contaminants and water quality stressors. He also provides expert professional advice relating to water quality risks, regulation, policy, and strategic directions, and represents the EPA as an expert witness in court.
Dr Paul Monis is a technical expert within SA Water’s Business Services group, which provides scientific expertise to support the delivery of water and wastewater services to SA Water’s customers. He has specialist expertise in the areas of biotechnology and microbiology, with almost 20 years’ experience applying DNA-based and other technologies to address water quality challenges posed by microorganisms, especially enteric pathogens. Dr Monis also holds title of Adjunct Associate Professor at Flinders University, the University of Adelaide and UniSA.
Jennie’s role in the Department for Environment and Water (DEW) allows her to foster and strengthen opportunities for researchers to better connect with government to enable evidence-based decision making. Jennie has extensive experience working in both universities and government, allowing her to bridge the divide between the two sectors. She is focused on connecting natural resource researchers with natural resource decision makers, and facilitating fit for purpose partnerships.
Dr Tanya Doody is a Principal Research Scientist working on high impact spatial eco-hydrological projects within CSIRO’s Land and Water Business Unit. Dr Doody leads the Managing Water Ecosystems Group, based in Adelaide, Albury and Canberra and has significant experience in quantifying the water requirements of vegetation and at times, their impact on water resources. This involves ecophysiological field-based research to underpin remote sensing tools to scale regionally to improve our understanding of the effect of flood regimes on the health of water-dependent ecosystems on the Murray-Darling Basin floodplains. Additional research includes investigating the ecological response of vegetation to water availability and environmental water to inform integrated basin water planning and management.
Professor Lin Crase is Professor of Economics and Dean of Programs (Accounting & Finance) at UniSA. He joined UniSA in February 2016 as Head of School of Commerce. Prior to commencing at UniSA, Lin was Professor and Director of the Centre for Water Policy and Management at La Trobe University.
Lin’s research has focused on applied economics in the context of water. He has analysed water markets and the property rights that attend them, water pricing and numerous applications of water policy. Whilst his expertise includes the Murray-Darling Basin in Australia, he has also worked on projects in south Asia, Japan and Europe. Lin has published over 100 journal articles, numerous book chapters, four books and a range of other papers and opinion pieces.
Justin has broad research interests in limnology and water treatment with a primary focus on coupling between hydrodynamics, biology and water quality contaminants such as cyanobacteria and pathogens. He is a founding member of the management committee of the IWA Specialist Group on Lake and Reservoir Management and member of the Steering Committee for the Global Lakes Ecological Observatory Network.
Justin has a PhD and a Bachelor of Science degree with Honours from the University of Adelaide.
Daniel Flaherty is the Accountant for the Goyder Institute for Water Research.
Daniel has extensive experience in higher education having worked in senior financial management roles at the University of South Australia, Flinders University and the University of Adelaide over the past 26 years. Daniel has also been a Board Director on a number of university related entities. Prior to that, Daniel has worked in a range of agencies in the Commonwealth and State Governments.
Daniel is a Fellow of CPA Australia and has a Bachelor of Economics from the University of Adelaide.
Alec Rolston joined the Institute in 2021 as Research Program Manager of the Goyder Institute’s research projects in the Healthy Coorong, Healthy Basin program. He has extensive experience in integrated water resource management, integrated catchment management, drinking water source protection and wetland ecology, conservation and management across Europe and Australia.
Alec holds a PhD from the National University of Ireland Maynooth and has worked with An Fóram Uisce|The Water Forum and the Dundalk Institute of Technology in Ireland as well as the MANTEL Innovative Training Network across Europe.
Alec spent his early career in Adelaide working with Flinders University through the Coorong, Lower Lakes and Murray Mouth (CLLAMM) Ecology Research Cluster and within the Department for Environment and Water.
Daniel Pierce has managed research projects at the Goyder Institute for Water Research since November 2017 under both the second and third terms of the Institute.
Daniel brings experience in project management and knowledge transfer and application from 4 years working as a Senior Hydrogeologist in the Department for Environment and Water (DEW) in South Australia and from 13 years of private sector work in environmental management, science and engineering in Australia and the South Pacific. His work with DEW has included providing technical advice to the development and revision of Water Allocation Plans around South Australia in collaboration with researchers and policy makers, and managing a team of groundwater modellers and hydrogeologists involved in an assortment of water resource management issues.
Daniel has a Bachelor of Engineering (Hons, Environmental) and a Bachelor of Science (Geography) from the University of Western Australia.
Professor Lombi’s main contributions to environmental research cover various aspects of contaminant risk assessment, biogeochemistry, ecotoxicology and waste management. Furthermore, the methodological development he has pursued in his research has provided the basis for collaborative efforts in a variety of research areas ranging from soil fertility and plant physiology to human health issues related to contaminant uptake via occupational exposure and diet. In the last few years he has been increasingly focusing on the transformation and toxicity of manufactured nanomaterials in the environment.
Dr Carmel Pollino is a Research Director for Land and Water at CSIRO. She has 20 years of experience working on water issues in Australia and throughout Asia. Carmel has degrees in science and environmental law and works across the science and policy interface. Significant areas of research in Environmental Flows, Hydrology, Ecology and Integrated River Basin Planning. Carmel is the lead and also a contributor to global working groups on water and has published widely in this domain.
Professor Bronwyn Gillanders is interim Head of School of Biological Sciences at the University of Adelaide. Prof Gillanders completed her BSc at the University of Canterbury, MSc at the University of Otago and her PhD at the University of Sydney. She has a research background in environmental science focused predominantly on freshwater and marine ecology.
Her research interests include integrated marine management; coastal carbon opportunities; multiple use activities and cumulative impact assessment; biology, ecology and fisheries of cephalopods; stocking and provenance of fish; plastics in the marine environment including in seafood; use of fish bones (and other calcified structures) for assessing ecological and environmental change. She has trained and mentored ~70 Honours and Higher Degree Research students and shaped the future of 1000s of students through her undergraduate teaching. She is passionate about encouraging capable women to enter and remain in science careers.
Dan Jordan is the Director, Water Security, Policy and Planning, Department for Environment and Water (DEW). Dan is also the Basin Officials Committee Alternate Member for South Australia.
Professor Okke Batelaan is a graduate of the Free University of Amsterdam, Netherlands (MSc – Hydrogeology) and of the Free University Brussels, Belgium (PhD – Engineering). He worked for more than 20 years at the Free University Brussels and also led the hydrogeology group at the KU Leuven, Belgium since 2006. He was chairman of the Interuniversity Programme in Water Resources Engineering.
Since 2012 Okke Batelaan is Strategic Professor in Hydrogeology and currently Dean of the School of the Environment, Flinders University. Okke has broad experience in teaching groundwater hydrology, groundwater modelling, GIS and remote sensing for hydrological applications. He was supervisor of more than 140 MSc and 25 PhD students. He has extensive research experience and a publication record in shallow groundwater hydrology and modeling, recharge-discharge estimation and modeling, urban hydrology and distributed modelling, ecohydrology and impacts of land use and climate change on groundwater systems. He coordinated and participated in a large number of projects in Europe, Africa, South America, Asia and Australia. He is editor-in-chief of Journal of Hydrology: Regional Studies and of MDPI-Hydrology.