Microbeads derived from personal care products that are introduced to waste water treatment streams and contaminated by persistent organic pollutants are an increasing area of concern for terrestrial and aquatic ecosystems. Two experiments that exposed earthworms to the persistent organic pollutant PBDE were conducted using contaminated microbeads at 100 ng/g and an OECD recommended soil in laboratory conditions for 16 and 21 days to determine if the PBDEs adsorbed to the microbeads were bioavailable to the earthworms. Uptake of most PBDE congeners was found to be statistically significant when compared to the experimental controls in both experiments with the congener uptake resembling trends seen in previous earthworm studies that examined PBDE contamination of biosolid amended agricultural fields.

Honours Thesis completed by Damien Moodie in June 2016.

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.

Recycled water usually contains extremely low levels of many different chemicals. The Australian Guidelines for Water Recycling (AGWR) require that some of these cannot exceed levels that would pose a risk to health, safety or the environment but there are concerns that one or more of these, or other, unmonitored micropollutants, might present a risk, or that chemicals that individually are harmless might add together and have undesirable effects. This research measured 300 organic micropollutants (listed by the AGWR) in a range of recycled waters and conducted a series of laboratory experiments. It was concluded that the toxic effects of individual chemicals often do add together but that this can be predicted accurately in most cases. Some disinfecting processes used to recycle water produce new micropollutants and it will never be possible to completely analyse the thousands of chemicals in any one water sample. These results led to the recommendation that classical chemical analytical measurement techniques should be complimented by a suite of bioassays which can quantify the total toxicity of all the mixed chemicals within recycled water.

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 must be treated to remove harmful pathogens and chemicals before it can be released to the environment, but the cost of proving that all pollutants have been removed is prohibitive because potentially thousands of separate chemicals would have to be measured. Another problem is that classical chemistry measurement tests are sometimes not sensitive enough to be able to detect the very low levels of chemicals which still harm animals and plants. This research developed a suite of extremely sensitive in vitro cell culture tests and an in-situ laboratory test in which mosquitofish were observed when swimming in recycled treated water. These bioassays measured the effects of mixtures of contaminants and were compared with traditional chemical measurements of separate contaminants. The in vitro cell culture, in situ mosquitofish and classical chemical analyses of selected contaminants generated equivalent results and led to the conclusion that combining multiple lines of evidence into a toolbox approach for the assessment of water quality provides data which is more informative and relevant when assessing potential impacts on the environment than traditional chemical measurements alone.

Wastewater (WW) contains harmful chemicals, including pesticides, that can disrupt normal gene function or hormone activity. The cost of measuring each separate contaminant at the frequency needed to demonstrate the safety of recycled WW is prohibitive. This research reviewed the risk assessment and regulation of chemicals in Australian water, with a focus on ‘thresholds of toxicological concern’. Laboratory techniques were developed to extract and concentrate WW contaminants into solutions suitable for analysis using both new in vitro cell culture assays and analysis in expensive, established chemical tests. WW and treated samples were collected from nine Australian water reclamation plants. The total effect of each sample (which contained a mixture of contaminants) on cell death, gene integrity and aspects of liver, hormone, nerve and immune system activity, was determined using in vitro cell culture bioassays, and compared with the classical chemical measurement of each separate contaminant. The cheaper cell-culture tests correlated well to the levels of groups of chemicals and could be used to find thresholds of toxicological concern. Both testing regimens also demonstrated that reverse osmosis is a highly effective method that removes harmful chemicals to levels much lower than those designated safe by regulatory authorities.

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.

It is prohibitively expensive and time-consuming to monitor drinking water by individually quantifying every possible polluting contaminant. Instead, living cells can be cultured in samples of the test water and if one or more toxic contaminants are present the cells die. Less toxic, more subtle effects can also be measured, for example, a toxicity test that uses cells collected (decades ago) from one monkey kidney, quantifies cell death but also measures the amount of protein made by each live monkey kidney cell. The problem with this, and other toxicity tests, is that chlorine disinfectants and harmless low levels of other substances, such as aluminium or copper, which occur naturally in water, can sometimes have inhibitory effects on the ‘bare’ cells that are often more sensitive when cultured inside laboratory culture vessels than when they were in a normal situation within a body. This research identified commonly used toxicity tests that are not affected by disinfectants or naturally occurring harmless substances, and also worked out some solutions that quench disinfectants and allow cost-effective and useful cell-based toxicity tests to be used to monitor the safety and quality of drinking water.

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.