This project determined the decay rates of E. coli, S. typhimurium, bacteriophage (MS2) and adenovirus in biosolids-amended soil used in agriculture. The die off rates of these pathogens were tested over the duration of the growing season in a wheat crop at sites in the central wheatbelt of Western Australia and in South Australia.

PhD Thesis completed by Karen Rosemary Schwarz in March 2012.

Water supply and wastewater services are two connected components in an urban water system. They are in most cases operated separately towards sub-system optima. By recognising and enhancing their connections, an integrated management strategy would deliver system-wide optimisation with tremendous economic and environmental benefits. This project developed and demonstrated an integrated and innovative strategy, and the associated science and technologies, to achieve multiple beneficial uses of iron salts in an urban water system.

Predicting the effects of climate change is a complicated business. A climate change model might relate temperatures to air flow and patterns of rainfall in a defined geographical area, important information for planning the construction of future dams and water storage reservoirs. The problem is that it is difficult to extract and transfer knowledge from the climate model into the planning and design process; there is a gap between climate science and those who need to apply the knowledge. This project bridges that gap through the establishment of a suite of strategies to further improve the ability of decision-makers to understand and integrate climate change into their ‘business-as-usual’ water planning and management practices.

The development of a toolkit of climate change adaptation supporting resources, called ‘Resiliwiki’, provides Water Research Australia members a valuable resource, allowing them to rapidly identify appropriate decision evaluation methods for a given decision. Although aimed at the water industry, this decision framework for transferring climate change science into adaptive practice is also valuable for government organisations and environmental, health and economic planners.

Water utilities lack the information they need to implement risk-based adaptation and planning strategies that incorporate climate change. This research addresses this problem by modelling the effects of climate change on reservoirs in three climate zones: temperate, humid tropical and Mediterranean. By integrating different modelling approaches it was concluded that increased temperatures will increase water stratification; the differences in water temperature that occur with depth. This is important because the duration and type of stratification affects the storage and release of substances from reservoir floors and this in turn affects blue-green algal blooms and water quality. The integrated modelling approach developed in this project can be applied to the management of contaminants running off the catchments and for future risk assessment. This information will also support the development of business cases for targeted catchment interventions.

Climate change is depleting water resources, while population increases drive demand for additional recreational facilities, particularly in the vicinity of urban centres. It was thought that public access to water catchment land and reservoirs might cause large-scale outbreaks of disease, and that the water-consuming public would have to pay more for the additional water treatment required to keep drinking water free of the organisms that cause infectious disease. Some consider this unfair because it is an added expense that results from recreational access by a minority of the population. This research considered peer-reviewed literature, policy and regulation, hazard and risk assessment procedures, and placed these in the context of interviews, focus group interactions and surveys. It was concluded that although the science of the adverse effects of recreational access on water quality continues to stand up to examination, there is now justification for conducting an advanced risk-benefit analysis which was developed during the study. This uses a ‘multi-attribute utility’ approach that enables assessment of any given situation by incorporating cross-impact matrices. This risk-benefit methodology addresses the significant issues that arise when adjusting or implementing new recreational access priorities.