Remote communities have an issue with hardness levels in water supplies.  This project established the cost impact of hard water on household infrastructure in remote Indigenous communities.  The results of this project enabled Power and Water Corporation to form a business case to improve the water quality for the communities they support.

Honours Thesis completed by Heather Browett in November 2011.

Source waters contain a class of chemical compounds collectively known as ‘bromides’. Standard water treatment includes chlorination; a process designed to kill harmful microorganisms in source and recycled waters. The problem is that chlorination agents react chemically with bromides to form ‘brominated Disinfection ByProducts’. These bDPBs can contribute to the development of cancer and this led the Australian Drinking Water Guidelines to recommend very low concentrations of bromides in source waters, less than 0.1 parts per million (0.1mg/L). At this level, if any bDBPs subsequently formed during chlorination, their occurrence will be too low to pose a public health risk. Some Australian source waters have higher bromide concentrations, but existing removal methods are expensive and/or do not work very well. The scientists in this team have already synthesised a new bismuth substance (see image) that removed 86% of an experimental bromide from artificial groundwater.

This project will aim to combine the modified bismuth with alum, which is currently used to treat water. If researchers succeed in creating a composite that incorporates bromide removal into existing tried-and-tested water treatment processes they will deliver a cost-effective improvement to water quality and safety. However, it will require clever and careful chemical design to create the new bismuth-alum composite, and to run experiments that will test its ability to remove bromides from source waters. As if that isn’t challenging enough, they also propose to develop a software programme that will predict bDBP formation. If they are able to eventually build a validated model it will be an extremely useful addition to the suite of tools currently used to produce safe, high-quality drinking water.

The ‘One Water’ paradigm recognises the interconnectedness of groundwater, stormwater, wastewater, flooding, water quality, wetlands, watercourses, estuaries, and coastal waters, and integrates multi-use, flexible and environmentally sustainable systems while valuing all urban water flows as a potential resource. Decades of water production, sewage treatment and urban development, have resulted in pipe and pump-station networks with the associated procedural systems for regulation and governance. Altogether, these form barriers to ‘One Water’ recycling and reuse. This research investigated, described, and defined these barriers and the strategies and actions used to overcome them. This was accomplished by reviewing published literature, by collating case studies and by recording the outputs of interactive workshops. It was concluded that obstacles to ‘One Water’ include the existing system of centralised and silo-ed expertise and the current complex structure of regulations governing safety of water supply, wastewater, and stormwater management. Research findings were used to develop a framework for transitioning to more flexible ‘One Water’ management processes which focus on integrated resource planning, incremental implementation, and the collaboration of traditional urban planners with water resource managers.

The protection of sources of water and catchments is an important method for maintaining water quality; one that can mitigate cost and reliance on downstream water treatment and disinfection. Catchment protection requires risk assessment, but water quality management approaches were not originally developed for natural environments, and ecosystem-based methods (such as the Ecological Risk Assessment methodology), require complex data inputs often unavailable to water utilities.

This paper discusses various water quality risk management techniques and proposes a step-by-step catchment risk assessment methodology that is compatible with the Australian Drinking Water Guidelines.

The aim of this project was to examine the utility of ultra-violet (UV) spectroscopy as a real-time water quality monitoring system. Two case studies were conducted. One assessed stormwater and showed that the UV system could detect that the first flush contained chemicals used as surrogates for water quality whereas later flows contained bacterial and biological markers. From this it was concluded that the sources of bacteria and chemicals were probably physically separated until they were mixed during surface runoff. In the second case study, the UV measurement equipment was set up in a groundwater filtration plant. It proved possible to accurately characterise water quality changes and assist operational decision-making.

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.