The occurrence of per- and polyfluoroalkyl substances (PFAs) in various environmental media is of great concern due to their potential adverse effects on living organisms. This project aims to investigate the feasibility of natural-occurring foams in aeration tanks for removal of PFAs and other contaminants of emerging concern from sewage.

PhD Thesis underway by Angel Chyi En We.

Catchment health metrics are physical, chemical, biological, and socioeconomic indicators that collectively provide a holistic measure of a catchment’s state and functional capacity. Catchment health metrics can provide an effective mechanism for not only assessing the health of a catchment but also a means of assessing the effectiveness of catchment control measures being implemented by management organisations. There is great diversity of catchments within Australia, displaying vastly different physical, chemical, biological, and hydrological interactions socioeconomic characteristics. Additionally, these catchments are impacted by a variety of land uses, levels of public access, types of water sources and receiving environments, demanding often very varied management responses. To ensure that catchment health information is useful for decision making, catchment health metrics should represent the dominant variables that impact the critical community environmental values provided by the catchment. Given the diversity in catchment characteristics, it is unlikely that a fully standardised set of catchment health metrics can accurately represent all types of catchments. This project will investigate and identify environmental indicators that would feed into a tailored catchment health assessment framework which would provide decision makers and regulators with a common paradigm and consistent approach to evaluate the state of a catchment and quantify the costs, benefits, risks, and opportunities of different management scenarios.

Source water protection underpins the safety and affordability of drinking water supplies where the prevention of water contamination provides greater surety than removal of contaminants. The Australian Drinking Water Guidelines emphasises the protection of source waters to the maximum degree possible as part of the multiple barrier approach to mitigate possible contamination.

Meanwhile, water utilities have been placed under increasing pressure to introduce or increase recreational access to drinking water catchments and water storages. There is also a lack of consensus around the impacts of different types of recreational access across Australia.

This project will summarise the current state of play of recreational access in Australia, report on the risks associated with different types of access, outline the types of cost benefit analyses that utilities can use when assessing recreational access, and promote a national understanding of risk to public health and water security.

Several cyanobacteria species are well known for their potential to produce cyanotoxins. However, not all genotypes of known toxin producing species produce cyanotoxins and of these there is significant variation in the spatial and temporal dynamics of toxin production. The water industry currently relies of observational measurement of the presence of ‘potentially toxic species’, toxin gene and toxin presence to inform management of cyanobacteria blooms in water supply storages. Predictive tools and preventative management are limited by a lack of simple environmental predictors to predict toxin production events. Understanding the drivers for toxin production that inform risk management frameworks would be of great benefit to water supply managers and to inform alternate management options. These tools would enable better responses to bloom events and allowing for the establishment of pre-emptive measures to minimize cyanotoxin production by targeted manipulation of environmental drivers.

Lakes and reservoirs are essential for water supply for humans and agriculture, and have an important role in flow regulation, biodiversity, and streamflow below dams. Australia has been subject in recent decades to severe drought which has heightened the importance of reservoirs for human populations and highlighted the need for careful management of water levels to maintain continuity of supply. Climate change is likely to exacerbate water shortages, with extended periods of drought, interspersed with more discrete and intense rainfall, leading to challenges for storing water in reservoirs and potentially affecting the quality of water.

In this project, Griffith University researchers examined the water quality risks from low and variable water levels in dams and reservoirs in Eastern Australia.

There are more than 3000 per- and poly-fluroalkyl substances (PFAS). They have unique chemical properties that makes them ideal for incorporating into stain and water-resistant materials, and for metal-plating, firefighting and medical imaging, but there are concerns that PFAS are persistent and toxic. The Australian federal government updated the PFAS National Environment Plan in 2020 and provided an aquatic and marine ecological guideline value of 1900 ng/L for a common PFAS, ‘PFOA’. This is a concentration that will NOT harm 99% of the species in those habitats. The safe guideline for ‘PFOS’ in drinking water is 2000 ng/L. This research measured 21 types of PFAS in 19 Australian wastewater treatment plants (WWTPs) and found that the WW treatment processes transformed small (short-chain) PFAS into stable ‘PCFA’ forms, and that when the concentrations of 21 common PFAS’s were added together there were, on average, only 142 ng/L in treated WW effluent. Although these concentrations are much lower than safe guideline values, it was concluded that ongoing monitoring is required to further understand the risk that effluent discharge might pose to aquatic ecosystems.

Fish, frogs, and other aquatic animals sometimes show signs of ‘endocrine disruption’; aberrant changes to their hormone or reproductive systems that are thought to be caused by chemicals in the water they inhabit. Very few of these chemicals have been identified, and this prevents the use of classical chemistry-based analytical methods. The other problem is that the levels of hormone-like chemicals which have endocrine-disrupting biological effects tend to be so low that standard methods cannot detect them. This research developed a suite of biological tests sensitive enough to detect very low levels of chemicals associated with certain types of endocrine disruption. These tests were used to examine wastewater, surface water and drinking water collected from Australia, South Africa and four European countries. The water samples were also subjected to standard chemical analysis, and the datasets compared. It was concluded that some wastewater and surface water samples contained compounds that interacted with components of the estrogen, progesterone, androgen and mineralocorticoid hormone systems, but none of the biological tests detected endocrine disrupting activity in drinking water.

Fish, frogs, and other aquatic animals sometimes show signs of ‘endocrine disruption’; aberrant changes to their hormone or reproductive systems that are thought to be caused by chemicals in the water they inhabit. Very few of these chemicals have been identified, and this prevents the use of classical chemistry-based analytical methods. The other problem is that the levels of hormone-like chemicals which have endocrine-disrupting biological effects tend to be so low that standard chemical methods cannot detect them. This research developed a suite of biological tests sensitive enough to detect very low levels of chemicals associated with certain types of endocrine disruption. These tests were used to examine wastewater, surface water and drinking water collected from Australia, South Africa and four European countries. The water samples were also subjected to standard chemical analysis, and the datasets compared. It was concluded that some wastewater and surface water samples contained compounds that interacted with components of the estrogen, progesterone, androgen and mineralocorticoid hormone systems, but none of the biological tests detected endocrine disrupting activity in drinking water.

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.

Cyanobacteria (blue-green algae) which float in reservoirs have been studied for decades because when they bloom, the very high cell numbers cause a problem for water treatment plant (WTP) operators, who have to remove the cells, toxins, and taste and odour compounds they produce. Benthic, bottom-living cyanobacteria which also produce toxins were recently discovered in Australian reservoirs. The problem is that benthic cyanobacteria are not included in routine monitoring practices and very little is known about them. This research provided information about the incidence of benthic cyanobacteria and the toxins they produce in various catchments; identified environmental conditions that stimulate bloom formation, and investigated naturally occurring biodegradation of taste and odour compounds. It was concluded that there is a need to monitor benthic cyanobacterial mats to ascertain the risk they pose, and to obtain additional in-situ data about more benthic species, because this will support the construction of predictive models to facilitate improved management of catchment and source waters.