The Australian water industry is currently focused on two VOCs, namely geosmin and MIB, which release an earthy-musty smell. Microorganisms that live in source water or within water distribution pipes are known to produce other unpleasant VOCs. This project intends to detect and quantify taste and odour (T&O) chemicals beyond geosmin and MIB in source water through chemical and sensory analysis. Project aims to identify and/or semi-quantify these unknown VOCs in source water and develop T&O wheel specific to NSW source water. The project also anticipates developing a risk indicator database for different T&O chemicals.

Thesis underway.

This project revised operational methodologies in all systems from catchment to tap providing an improved understanding of the resource and cost implications.  The research informed the development of future water plans providing improved aesthetic impact for customers.

Honours Thesis completed by Tara Callingham in August 2017.

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.

This project aims to better understand chemical and biological hazards in Australia through long-term collection and analysis of wastewater and biosolids. Samples collected during the Australian Bureau of Statistics’ (ABS) Census 2021 will form the basis of a rich and unique databank that describes how communities are exposed to chemical and biological hazards, and how these chemicals/biological agents are released into the environment following wastewater treatment. The previous ARC-funded SewAus Census 2016 project (LP150100364), successfully established the first, globally unique nationwide program for wastewater-based monitoring of chemicals. SewAus Census 2016, demonstrated the utility of integrating wastewater-based monitoring with detailed, accurate data on the population that contributed to the sample from the Census. Demographic and socioeconomic data, such as age or occupation, were used to explain patterns of drug use and other chemical exposure in the population. A wide recognition of the value of this work forms the basis of this new proposal.

Together with existing and new stakeholders and end-users, a follow-up project has been developed to build on the outcomes of SewAus Census 2016 and address a new set of aims. This research has three overarching goals founded on:

• Advancing sampling and analytical methodologies to expand the scope and reach of wastewater-based monitoring in Australia;
• Measuring and understanding spatial and (long-term) temporal trends for chemical and biological hazards, and;
• Improving quantitative understanding of the sources and fate of chemical and biological hazards released to the environment from wastewater treatment plants (WWTPs).

In 2006, strict restrictions on using tap water for gardening or car-washing were imposed in Melbourne but relaxed in 2010-2011 as rainfall replenished depleted reservoirs. During this five-year period residents collected their own greywater from washing machines and laundry, showers, baths, and kitchens. The problem with this is that people with diarrhoea and gastrointestinal illness might soil bed linen or clothes, or have an accident in the bathroom, and inadvertently transfer pathogens into the greywater. The worst-case scenario is that greywater containing infectious pathogens is used to water lettuce in a way that transmits infection to those eating unwashed leaves. The Environmental Protection Agency of Victoria (EPAV) published Guidelines (2008) designed to minimise harm to health or the environment. This research examined 1621 households and concluded that although half knew the guidelines existed, they were not following the advice, but nevertheless, although this study was limited, there appeared to be no significant increase in gastrointestinal illness. This research recommended that future housing design incorporate integrated water management strategies to enable safe greywater collection.

Water supply is usually continuous, and interruptions to supply are expensive and inconvenient. Most direct tests for the waterborne pathogens that cause illness are too slow and expensive to be used for the routine monitoring of water safety. Instead, the Hazard Analysis and Critical Control Point (HACCP) system, which was originally developed and implemented in the food industry, has been applied to manage microbiological and chemical contaminants in water treatment plants. This research extended the HACCP approach to water recycling and reclamation processes, by completing a literature review, collating and analysing existing datasets and case studies, conducting a gap analysis, running some pilot trials and preparing three HACCP template plans for use by water utilities, including those in America, when developing their own HACCP systems.

Wastewater often contains endocrine disrupting compounds (EDCs) such as ethinyl estradiol (EE2) which is excreted by women who use some oral contraceptive pills. When wastewater treatment is followed by advanced recycling processes, most of the hormone-like EDCs are removed, but it is possible that these very low levels might still adversely affect health. Giving recycled water to mice will allow examination of these health risks but it is first necessary to develop methods to measure extremely low levels of three forms of estrogen (estrone, estradiol and EE2), as well as progesterone and bisphenol A (BPA), an EDC that leaches out of plastic drinking bottles. This research modified clinical ‘ELISA’ tests commonly used to measure hormones in patient blood samples, and established protocols that allowed the sensitive quantification of five EDCs in recycled water.

There are concerns that recycled wastewater used for watering gardens or washing cars might be accidently ingested. The problem with this is that water for irrigation is not recycled to the same high (and expensive) standard as potable drinking water and might contain pathogens that cause diarrhoea and illness. Recycled water providers must quantify the risk that irrigation water might pose to public health, even though it is not supposed to be drunk. This research worked on the first part of this health risk quantification problem by developing a method to measure the amount of water a person might ingest while, for example, washing a car. Harmless cyanuric acid is commonly added to swimming pools and swimmers often ingest pool water. The amount of cyanuric acid measured in their urine is related to the volume of pool water they ‘drank’. Domestic users of recycled water are more likely to ingest less recycled water than swimmers, so a more sensitive ‘GCMS’ method for measuring very low levels of cyanuric acid was developed. It was shown to work after cyanuric acid was added to water, drunk by three adult volunteers, and then measured in their urine.

Although a cluster of customer complaints can identify specific water quality issues such as a dirty water event, it is more difficult to understand the extent of general customer satisfaction with water quality and taste. The Final Report for this project includes four printable water quality Factsheets for the general public which explain tastes and odours, fluoridation, and disinfection. The Report also includes the protocols and texts for two customer engagement techniques: Blind Taste Testing and Systematic Taste Testing; as well as a comprehensive customer survey instrument to assess perceptions of drinking water quality. These can be downloaded to electronic mobile devices and used to direct face to face customer engagement with the tastes and odours of different types of potable water. The scoresheet links to a rating spreadsheet that collates results and generates graphical representations of customer acceptance of water sample taste. These tools have been used to assess customer satisfaction with water quality at large events including National Water Quality week or Utility information days.

Cryptosporidium, a microscopic single-cell parasite, forms an “oocyst” with a resistant outer layer analogous to an eggshell. Oocysts survive for a long time in the environment but UV in sunlight, and high temperatures that cause desiccation, kill them. If a mammal drinks water containing live oocysts, they embed in the gut wall and continue their lifecycle until eventually many more oocysts are excreted. There are 26 species of cryptosporidium but only five infect humans, and two; Cryptosporidium hominus and Cryptosporidium parvum, cause approximately 95% of all human infections. C. hominus occurs only in humans, but C. parvum is also found in cattle, sheep, and other animals. The problem is that human-infecting oocysts are excreted by animals in catchments and rain can wash live oocysts into water reservoirs. This research collated peer-reviewed published literature, and information and data collected by the water industry, then characterised the distribution of different Cryptosporidium species in Australian catchments. This led to recognition of a research need to track and predict live and dead oocyst transport during different weather events, and to model and evaluate catchment management initiatives such as excluding cattle from reservoir areas.