Increasing water demand due to a growing population and improved lifestyles is exerting greater pressure on existing water resources. The increasing number of contaminants entering the water supplies is further challenging water authorities worldwide. This project investigated using membrane filtration as a physical separation process and as an effective barrier for a wide range of inorganic and organic contaminants, producing excellent quality product water.

PhD Thesis completed by Muhammad Umar in October 2014.

European carp have decimated native fish species in the Murray-Darling River. The federally funded National Carp Control Plan proposes using a carp-specific virus to kill the pest-fish, but before doing so are consulting with a broad array of environmental, conservation and other stakeholders, including the water industry. There are concerns that large amounts of dead and decaying carp near water offtakes or storages might overwhelm the capacity of water treatment plants (WTPs) to remove organic matter and taste and odour compounds, and might compromise the production of safe, palatable drinking water. In this research a series of experiments led to the conclusions that medium to high carp densities could be managed by adding a 30 minute procedure to existing WTP methods, and that there would not be an increased risk to public health.

The ADWG has methods for predicting risks to water quality, but these were not developed for managing extreme climate-change driven weather events such as bushfires or floods. This research developed a risk assessment tool for managing water-related health risks associated with extreme weather events. Real-world datasets and experience of water cloudiness (turbidity), colour and blue-green algae were used to create and validate environmental models which were developed further by applying Baysian network and System Dynamics concepts. This iteration of the model was not constrained by, and did not reflect existing risk profiles, but was judged to be flexible enough to provide a realistic representation of future hazards arising from extreme weather events.

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.

Some remote and regional areas of Australia rely on groundwater. A problem with this is that naturally occurring salts, such as calcium carbonate, make the water ‘hard’ and cause scale deposition on the elements used to heat water. Scale also blocks taps and showerheads. This research examined different methods for predicting the amount of scale that a groundwater might form and also considered the pro’s and con’s of various treatment technologies which prevent scale formation. The consideration of community size and the chemical characteristics of different groundwaters was incorporated into this assessment and recommendation for scale prevention.

Blue-green algae are a nuisance, especially when they bloom and grow to high numbers in water storages and reservoirs. Traditionally, the water industry killed unwanted algae by adding copper sulphate. The problem is that this algicide is toxic and kills non-target species in the aquatic ecosystem. This project examined a range of alternatives by testing their practicality of application, efficacy, and cost.