Waterborne pathogens cause millions of people to be sick each year globally, putting a burden on hospitals and having financial implications. This research aims to identify the waterborne pathogens at the point of need, sample collection sites, water plants, treatment plants, water quality check points and drinking water quality assurance etc. The research outcomes will inform best practice for clean drinking water supply to the community thus improving public health and wellbeing.

PhD Thesis underway by Alka Rani.

Unexpected taste and odour (T&O) in drinking water is an emerging issue for the Australian water industry as it undermines customers’ trust in drinking water suppliers. Most water utilities monitor only cyanobacterial and microalgal populations, and measure only geosmin and MIB concentrations in raw water, which is likely to overlook the full extent of biogenic T&O challenges in the supply of drinking water. Conventional coagulation/flocculation/filtration are often adopted for T&O removal. The project intends to identify key producers in source water and determine the treatability of unknown T&O for the proactive management of drinking water.

PhD Thesis underway by Jin Zhu.

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.

The aim of Project 1127 was to help the water industry better manage and understand contaminants of emerging concern (CEC), through:

• The creation of a CEC database
• The development of a classification system based on source, treatment and effects to facilitate management of CEC by the water industry
• The development of risk assessment approaches based on different classifications (i.e., source, treatment and effects) and integrate this functionality into the database as a prioritisation tool
• Guidance on including CEC into current water quality risk management plans/frameworks (e.g. ADWG, AGWR)

N-nitrosodiumdimethylamine (NDMA) in drinking water is one of many factors – such as a persons’ genes – that cause cancer. Although NDMA is not a sole cause of cancer, the water industry aims to minimise its contribution to illness and disease. This research measured levels of NDMA in drinking and recycled waters and found the majority well below the Australian Drinking Water Guideline values that are considered safe for public consumption. Different sources of NDMA were identified and water monitoring and treatment strategies to optimise NDMA removal from source waters were recommended.

The Australian water industry uses a variety of membrane processes to remove unwanted pathogens or compounds, such as salt, from source waters. As membranes age their ability to fulfil these removal and filtering functions declines. The problem is that although there are recognised and validated tests for membrane integrity, they are usually performed only on new membranes, and information about the effect of membrane aging on pathogen removal is limited. This project reviewed published literature and identified four methods suitable for future development as Membrane Integrity Tests that may prove applicable to evaluate aging membranes during ongoing and long-term plant operation.

Approximately 11% of Australians use rainwater as their main source of potable water but this poses a potential health risk caused by chemical contaminants or microbial pathogens from birds or mammals being washed off the roof. In this study, rainwater samples from 300 households in Adelaide were collected for over a year. There are so many factors affecting a persons’ health that it is not possible to directly correlate water quality to participants health, but there was no significant effect of rainwater on the incidence of gastroenteritis. Levels of lead were higher than recommended by the Australian Drinking Water Guidelines in 2% of the tanks, and bacterial load was higher after rain washed roofs and gutters clean. This led to the recommendation that First Flush devices should be installed to divert early rainfall waters away from storage tanks. Microbial pathogens that cause human gastroenteritis were not detected.

This project developed analytical methods sensitive enough to detect the very low levels of compounds that leach out of old coal tar enamel-lined pipes, then catalogued the chemicals and the levels they were found at in a problematic pipeline. One of the chemicals leaching out of the old lining is probably acted on by microbes to produce another substance with an earthy, musty flavour. None of these were toxic in tests and they are therefore unlikely to pose a risk to human health.

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.