Water quality
SA Health and SA Water continue to work cooperatively to ensure the protection of public health in the supply of drinking water across South Australia. SA Water continues to comply with the requirements of the Safe Drinking Water Act 2011 including water quality monitoring and the notification of incidents, and successfully completed an independent audit against criteria in the Act in March 2025.
Monitoring of drinking water supplies was in accordance with SA Health approved monitoring programs. During 2024-25, SA Water collected 48,499 samples from customer tap locations within drinking water supplies throughout the state. Samples were analysed for compliance at these customer tap locations with the Australian Drinking Water Guidelines (2011) (ADWG) and results reported to SA Health in line with agreed reporting protocols. Compliance for E. coli was achieved 100 per cent at customer tap locations statewide. In addition, overall compliance with the ADWG for health-related parameters was 100 per cent for metropolitan systems and 99.99 per cent for regional areas.
In consultation with SA Health, SA Water undertook proactive investigative monitoring for per- and polyfluoroalkyl substances (PFAS) in key drinking water sources, including the six major metropolitan Adelaide reservoirs and the River Murray. All PFAS results were below detection limits, indicating no measurable presence. This initiative is consistent with a growing national interest in emerging contaminants and provides valuable data to inform future monitoring.
Incidents were notified and managed under the interagency Water/Wastewater Incident Notification and Communication Protocol and reported in a timely manner. Appropriate remedial actions and responses were implemented following incidents to ensure the protection of public health was maintained at all times.
The total number of incidents notified by SA Water during 2024-25 (138) has decreased since 2023-24 (179), with no Priority Type 1 incidents raised during this period.
Compared to 2023-24 (26) there was an increase in incidents (38) of detection of contamination in source waters and distribution system water tanks. The latter followed implementation of an enhanced tank inspection program in 2024-25.
These incidents were managed effectively and did not have a measurable impact on drinking water quality.
The number of incidents of drinking water reservoirs open to recreational activities (7) has increased since 2023-24 (3) with most involving non- compliant water access, including swimming. These incidents did not have a measurable impact on drinking water quality. High concentrations of the toxic cyanobacterium Cylindrospermopsis raciborskii were detected for the second year in a row in Lake Alexandrina, leading to advice against using the Goolwa Channel for swimming and diving. Lake Alexandrina is not used as source of drinking water.
The number of reported incidents for elevated cyanobacteria concentrations in drinking water source/s, waters including River Murray and reservoirs, decreased to 19 in 2024-25 compared to 26 detections in 2023-24.
Reduced rainfall events in this period contributed to a decrease in reported detection of enteric protozoa (Cryptosporidium and Giardia) in drinking water catchments and source waters from 31 reported incidents in 2023-24 to 14 reported incidents in 2024-25. There were three incidents involving detection of enteric protozoa including one in treated product water (Cryptosporidium) and 2 at the inlets to drinking water treatment plants.
Protozoa were not detected in follow-up samples. No faults were detected during the continuous monitoring of treatment plant performance during the periods when the protozoa were detected.
The Safe Drinking Water Act 2011 (the Act) and Safe Drinking Water Regulations 2012 provide the regulatory framework for drinking water providers in South Australia and are administered primarily by SA Health.
Provisions in the Act are underpinned by the Australian Drinking Water Guidelines (ADWG) and prescribe requirements for drinking water providers, including:
- registration of drinking water providers with SA Health
- development and implementation of risk management plans
- establishment of approved drinking water quality monitoring programs
- notification of incidents or non-compliance
- audits and inspections to determine compliance with the Act
- use of National Association of Testing Authorities (NATA) accredited laboratories for sample testing
- reporting of water quality test results to SA Health and providing consumers with drinking water quality information.
As a registered drinking water provider, we have established risk management plans, including approved monitoring programs and an incident notification protocol. We provide water quality testing reports for metropolitan and regional water supplies on a monthly basis.
An independent audit was undertaken in March 2025, as required by the Act. Conducted over 9 days, the audit assessed a selection of representative drinking water supplies through a combination of on-site inspections and desktop reviews. Site visits included the Anstey Hill Water Treatment Plant and its associated metropolitan network, the Adelaide Desalination Plant, regional groundwater and river-fed systems in the state’s south east, and the remote Aboriginal community of Nepabunna (Nipapanha).
The audit identified overall compliance with the Act and acknowledged the effectiveness of our comprehensive risk management plan and the supporting framework, that is demonstrably resulting in improvements to the safety and quality of water being provided to South Australians. Highlights identified by the auditor included:
- strong management review processes – system performance, key hazards and risks, emerging concerns, and audit outcomes are regularly reported to senior management
- significant improvement in the identification of water storage tank defects, and logging hazards with actions for resolution and risk reduction
- excellent progress in implementing recommendations identified in previous audit non conformances
- robust processes for operational monitoring and internal calibration of online instrumentation at all sites visited
- diverse and comprehensive internal staff training programs are in place, and the use of locals as ‘eyes and ears’ in some of the remote communities was viewed favourably by the auditor.
While most aspects of the audit were positive, as expected with a detailed assessment, 4 non conformances were identified, along with a number of improvement actions. As in previous years, these items will be reviewed and addressed through established corrective action processes.
Our Drinking Water Quality Management System adopts a proactive, whole-of-system approach to ensure the safety and reliability of drinking water at every stage, from catchment to customer tap. Our system is aligned with the ADWG Framework for Management of Drinking Water Quality and endorsed by the National Health and Medical Research Council. The framework is based on the best available scientific evidence and supports continuous improvements in water quality management.
We operate 90 drinking water supply systems serving customers across metropolitan and regional South Australia. This includes 3 new drinking water supplies commissioned in May 2025 located along the Barrier Highway at Mannahill, Terowie and Yunta. This landmark project delivered new elevated water storage tanks, water main network upgrades and additional water disinfection stations and brings each town’s drinking water supply in line with the health and safety requirements outlined in the ADWG.
We implemented SA Health-approved drinking water quality monitoring programs, ensuring the quality of our supply. These programs involve collecting around 440,000 results from samples at various stages of the water supply system, including catchment areas, source water, treatment processes, and distribution networks up to the water meter on individual properties.
We monitor for health and aesthetic compliance and to optimise water quality. Samples are collected by our trained field workers to make sure they are taken correctly and that field results have a high degree of integrity. Our Australian Water Quality Centre conducts laboratory analyses in compliance with ISO 9001 Quality Management Systems and NATA requirements.
Number of sample locations and test analytes – statewide, metropolitan and regional water supply systems, 2024-25
Drinking water systems | Statewide | Metropolitan | Regional |
Supply systems | 87 | 7 | 80 |
Customer tap sample locations | 528 | 173 | 355 |
Catchment to tap sample locations* | 1,545 | 346 | 1,199 |
Catchment to tap routine test analytes | ≈440,000 | ≈70,000 | ≈370,000 |
*Includes customer tap sample locations
In 2024-25, we demonstrated robust management of water quality by consistently providing safe, clean drinking water to our customers.
Health-related performance – statewide, metropolitan and regional drinking water supply systems, 2024-25
Health-related parameters
| Metropolitan systems (number of test analytes)
| Statewide systems (number of test analytes)
| Regional (number of test analytes)
|
Samples free from E. coli | 100.00% (3,252) | 100.00% (10,528) | 100.00% (7,276) |
Samples compliant with ADWG health parameters* | 100.00% (13,067) Target: 99.90% | 99.99% (48,499) Target: 99.90% | 99.99% (35,432) Target: 99.90% |
*Percentage of routine results at customer tap sample locations within drinking water systems which comply with the ADWG health limits
(including E. coli).
Direct exceedances of the ADWG were used rather than the 95th percentiles for compliance of individual chemical parameters.
Prior to calculating per cent compliance for health-related chemicals, individual results are rounded to the same number of significant figures as the guideline value in the ADWG (as prescribed in the ADWG and agreed with SA Health).
We analysed 48,499 samples from our drinking water supplies (customer tap sample locations) throughout South Australia to determine ADWG health-related compliance. Statewide, we achieved 100.00 per cent E. coli compliance and 99.99 per cent compliance with ADWG health-related parameters, exceeding our targets and confirming the safety of our water supplies.
Five exceedances were recorded across 3 of our 83 regional supply systems, all due to trihalomethanes. This represents a significant reduction in exceedances compared to previous years, driven by improved source water quality and enhanced treatment performance.
While we strive for 100 per cent compliance at all times, the ADWG acknowledges that occasional exceedances may occur, and for most characteristics, including trihalomethanes, these occasional excursions beyond the guideline value are not necessarily an immediate threat to health. In accordance with the guidelines and the interagency Water/Wastewater Incident Notification and Communication Protocol, all detections were immediately communicated to SA Health, investigated by us and then corrective actions implemented as agreed. SA Health confirmed that the drinking water we provide to customers is safe, and our responses effectively mitigated any risks to public health.
We apply the ADWG Framework for Management of Drinking Water Quality which includes 2 components for the management of incidents:
- communication
- incident and emergency response protocols.
Our Water Quality Incident and Emergency Management Protocol ensures we are prepared to respond swiftly and effectively to any water quality issue. We use a web-based incident management system to record, track and generate notifications for all water quality incidents.
This is aligned with the interagency Water/Wastewater Incident Notification and Communication Protocol that is maintained by SA Health. This protocol adopts the principles of the ADWG and meets the regulatory requirements of the Act and Safe Drinking Water Regulations 2012.
SA Health defines 3 types of health- related incident classifications based on a precautionary approach:
Priority Type 1 incident notification An incident that, without immediate appropriate response or intervention, could cause serious risk to human health and is likely to require immediate interagency meetings to consider responses. Procedures for Type 1 incident notifications also apply.
Type 1 incident notification/s
An incident that, without appropriate response or intervention, could cause serious risk to human health.
Type 2 incident notification/s
An incident that, without appropriate response or intervention, represents a low risk to human health.
Reporting period | Priority Type 1 | Type 1 | Type 2
|
2023-24 | 0 | 45 | 93 |
2023-24 | 0 | 50 | 129 |
2022-23 | 2 | 48 | 129 |
2021-22 | 0 | 50 | 86 |
2020-21 | 1 | 45 | 57 |
Note: these notifications do not include wastewater, recycled water and non-drinking supplies.
Priority Type 1 and Type 1 incidents are immediately reported to SA Health, while all Type 2 notifications are reportable within 24 hours, in line with the interagency Water/Wastewater Incident Notification and Communication Protocol. In 2024-25, no Priority Type 1 incidents were reported, and the total number of reportable incidents decreased compared with the previous financial year.
Over the previous 5-year period, the total number of reportable Type 1 incidents have remained relatively stable. Improvements were seen across several hazard categories when compared to last financial year, including chemical hazards, disinfection by-products and cyanobacteria. There was a rise in tank contamination-related incidents, primarily due to an expanded program of maintenance and inspection which enabled more comprehensive detection and reporting. Importantly, we are actively managing these contamination events through targeted infrastructure upgrades, including increased maintenance activities and an accelerated tank replacement program.
In 2024-25, we continued to focus on reducing the causes of preventable Type 1 notifications through targeted strategies and system-wide improvements. This included ongoing operational and capital improvements to strengthen system resilience, enhanced incident management training, optimisation of our drinking water quality monitoring programs to improve early detection and response and continuous improvement of our Drinking Water Quality Management System.
We maintained a proactive approach to managing water quality across our supply systems, with a continued focus on the early detection and effective management of potential risks during 2024-25. Changes in reporting criteria issued by SA Health in the interagency Water/Wastewater Incident Notification and Communication Protocol were incorporated into our processes to ensure continued compliance.
The Incident Response Index (IRI) guides correct responses when a Priority Type 1 or Type 1 incident is detected. The IRI is assessed against a number of criteria, with each component in the IRI designed to help manage water quality incidents.
Criteria used in the IRI based on total reportable SA Health Priority Type 1 and Type 1 incident notifications are:
* incident reported to relevant agencies by phone immediately (less than one hour)
* incident entered into the incident management system in less than 2 hours
* initial effective response taken within 3 hours
* written report to the Minister for Housing Infrastructure by 3pm the next business day
* root cause analysis completed within 10 working days
* preventive actions implemented within agreed timeframes. The overall 2024-25 strategic target for the IRI is 85 per cent compliance.
The Incident Response Index achieved for metropolitan and regional incidents
in 2024-25
System | IRI |
Metropolitan | 100% |
Regional | 97% |
Target | 85% |