The ADWG explains policies but does not provide the specific steps and actions needed to apply risk management principles within a water treatment plant (WTP). The original ‘Guide to Drinking Water Supply Systems for the Management of Microbial Risk’ (WaterRA Project 1074) filled this gap by providing Australian-specific advice about managing and optimising common water treatment processes to achieve microbial health-based targets. Since its publication in 2015 it has become a popular reference document, and its widespread acceptance and use has prompted the production of this second edition. Included are updated technologies and regulations, and a series of auditing tools and templates for application in a variety of situations, including the identification and quantification of risk.

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Failure to maintain appropriate levels of knowledge, skill, and experience in the frontline operator workforce runs the risk of disruption and loss of service delivery consequent to human error, along with associated risks to the environment and public health and safety. This research reviewed literature that reports water quality safety incidents, other industry training requirements, and forward-looking training preparedness for new technologies. A case study and water industry survey provided additional information for review. Five key operating principles proved important to operator development and training. It was found that the Australian water industry lacks workforce competency and management practices that are well-established in the aviation, nursing, electrical and engineering industries, and that many utilities do not use the Water Industry Operators Certification Framework, even though this provides the best pathway to frontline operator competency and management. It was concluded that the Australian water industry would benefit from considering regulatory changes to drive a nationally consistent governance approach to the provision of frontline operator training and competency certification.

Microbial pathogens are removed from source waters to make safe drinking water. Health-based targets (HBTs) refer to the quantities of pathogens that will NOT cause illness, and water treatment plants (WTPs) must ensure that the numbers of pathogens in potable water are the same or lower than the HBTs. WTP operators select the best pathogen removal treatment for a range of conditions such as season, rainfall and agricultural activity by referring to ‘sanitary surveys’. These are carried out approximately once a year by scientists driving and walking in the source water catchment, making observations, and collecting samples which are examined to look for indicators of harmful pathogens. Recent requirements to achieve HBTs, combined with technological advances, led to this project which aims to provide flexible sanitary survey guidance applicable to the broad range of Australian conditions and utilities. This Good Practice Guide reviews existing procedures, describes modern methods including aerial photography and the use of spatial databases, and describes the incorporation of sanitary surveys into ongoing source water operational monitoring in ways that support the establishment of log removal values and enable compliance with HBTs.

Water utilities need a method and framework which enables the identification and prioritisation of research into emerging water quality contaminants and pathogens. This research built a software tool that uses a Multi-Criteria Decision Analysis Bayesian Network model to guide a stakeholder through determining the relative importance of a series of criteria that were selected in consultation with the water industry. The model is flexible and allows the decision-maker to categorise priorities according to utility-relevant factors including time and location.

Water treatment plants (WTP) produce safe drinking water that does not contain harmful microscopic pathogens, but subsequent pipe-leaks or valve or hydrant malfunctions en route to the customers tap increase the risk of pathogens entering the public water supply. International studies indicate a small increase in gastroenteritis for some customers downstream of mains pipeline breaks and repairs. This research compiled Australian cases and found that health risks are probably lower than international examples for many reasons, including that sewer and drinking water pipes tend not to be laid in the same trench. After improving understanding regarding the contamination risks of renewal and water main repair activities in Australia, a control and management framework was produced in accordance with the ADWG. This gives guidance to water utilities about staff training, risk assessment and optimal documentation processes for dynamic site evaluations and repair control mechanisms.

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.

Although water utilities recognise the value of online instruments that provide real-time monitoring capability, there are problems with visualising and interpreting datasets, and with distinguishing between data resulting from real-world changes in treatment plant operating conditions, for example changed turbidity or flow, and instrument failure. There are also challenges around instrument installation and operation. This project developed tools to support data visualisation and interpretation by building a prototype visualisation platform for analysing complex online UV spectral data in conjunction with weather and lab data (see Factsheet 2 ‘Development of an online platform’). To improve differentiation between instrument failure and real-world data a Bayesian Belief Network model was developed to analyse patterns and variations within datasets. Real operational, high turbidity data was used to demonstrate that this model could accurately identify different causes for the readings which included filter ripening, backwash and other causes (see Factsheet 3 ‘Improving decision making in water plant operability through Bayesian Belief networks’). Strategies for instrument installation and operation were illustrated through case studies.

The ADWG prioritises the removal of microscopic pathogens (and the toxins some produce) from public drinking water supplies to prevent large scale outbreaks of illness. This principle underlies the importance of adhering to consistently high standards of water treatment plant (WTP) operation and maintenance. This Guide refers primarily to the conventional WTP processes of chemical pre-treatment, coagulation, flocculation, clarification, filtration and disinfection; and establishes target criteria and critical limits for each step in the treatment process. The Guide is designed to provide water utility managers and operations staff with a concise reference document to optimising the WTP processes that produce microbially-safe drinking water and additionally supports the establishment of microbial Health-based targets.