project description goes here

This project developed an understanding of the occurrence of regulated and emerging disinfection by-products (DBPs) in drinking water in Southeast Queensland (SEQ). This was achieved through the characterisation of natural organic matter of several SEQ source waters and through exploring strategies for halide and organic matter DBPs precursor removal from water, and examining the effect of these removal strategies on DBPs formation.

Honours Thesis completed by Kalinda Watson in October 2014.

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.

The protozoan parasites, Cryptosporidium and Giardia represent a major public health concern of water utilities in developed nations. In Australia, marsupials, cattle and sheep are the dominant animals inhabiting water catchment areas and contribute a large volume of manure to catchments. Cryptosporidium fayeri, one of the main species identified in marsupials, was identified in a 29-year-old woman in Sydney in 2009 with identical subtypes found in marsupials in the area. There have also been reports of C. parvum and C. hominis (the most common species found in humans), in kangaroos, a wallaby, possums and bandicoots by independent groups, as well as high prevalence’s of zoonotic genotypes of Giardia in marsupials.

This project conducted a comprehensive study of genotypes of Cryptosporidium and Giardia present in marsupials, pre-weaned cattle and sheep and STP sites, over a three-year period to gain a more thorough understanding of the zoonotic risk these parasites pose to humans. In addition to cataloguing the genotypes present using next generation sequencing technologies, researchers also enumerated the numbers of Cryptosporidium and Giardia (oo)cysts present in samples and conducted a survey of farming practices to determine if particular management practices were associated with a higher or lower prevalence of zoonotic genotypes in pre-weaned cattle and sheep.

Blue-green algae reduce water quality, especially when they produce toxins. Each algal cell can grow, reproduce all its DNA, and split into two ‘daughter’ cells, then those two ‘daughter’ cells produce four more until the numbers of algal cells bloom to extremely high numbers. High algal growth rates are associated with favourable environmental conditions (for the algae), stationary growth rates occur when the production of new cells is about the same as the number of dying cells, and if more cells die than are reproduced, the growth rate declines. The ability to predict or measure which of these three population growth rates is prevalent, and how much toxin is being produced, is information that the water industry needs to select the best methods for treating water. This project analysed the amount of DNA, and some specific sequences of DNA which correspond to the genes coding for toxins; and related the DNA analysis to actual counts of cells and measurements of toxin in water samples. This allowed the development of an improved and more informative technique for forecasting and monitoring toxic blue-green algae blooms.

The environmental conditions which cause blue-green algae (cyanobacteria) blooms vary according to location, the climate, and other attributes of aquatic ecosystems. This variety has made it difficult to develop one broadly applicable predictive model for cyanobacterial blooms. Water utilities monitor source waters to implement cyanobacterial risk management programmes but there are no standard protocols while limited information transfer between utilities has prevented the identification of management strategies that do or do not work. This research reviewed literature about early warning systems (Almuhtaram et al., 2021) and source control strategies, conducted a survey of 35 utilities in America and Canada (74%) and Australia (Kibuye et al., 2021) and evaluated selected control strategies. These different types of information were synthesised into decision trees within an overarching guidance document. It was concluded that a 3-tier framework to detect algal blooms which monitored biological activity, then confirmed the identification of cyanobacterial genes and associated metabolites gave sufficient early warning, while multi-barrier control strategies gave field-scale efficacy and enabled timely responses.

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.

The standards for recycling stormwater are higher for drinking water than for non-potable reuse such as agricultural or urban irrigation. The Australian Drinking Water Guidelines (ADWG) inform regulations that ensure the removal of infectious pathogens and polluting chemicals from potable water, whereas the Australian Guidelines for Water Recycling (AGWR) ensure that non-potable recycled water does not pose a risk to human health. Compliance with these Guidelines often requires quantitative risk assessment of stormwater catchments, but this is an expensive and resource-intensive process. This research developed a ‘Chemical Hazard Assessment of Stormwater Micropollutants’ (CHASM) desktop tool to assess the suitability of stormwater for various potable and non-potable uses before commencing an expensive risk assessment, and to guide design of optimal and targeted monitoring and measuring programmes for chemicals of concern in any given catchment. Basic information about each of four Australian stormwater catchments (including size, land-use, and surface types) was entered into CHASM Excel spreadsheets. The tool utilises a database to generate a list of likely pollutants for that catchment, and optimal locations and times for monitoring. The CHASM tool proved reliable and easy to use.