Water quality

Water quality

SA Health statement

SA Health and SA Water work cooperatively to ensure the continued protection of public health in relation to the supply of drinking water across the state. SA Water complied with all requirements under the Safe Drinking Water Act 2011 including the notification of incidents under the interagency Water/Wastewater Incident Notification and Communication Protocol.

During 2022-23, SA Water conducted 46,089 tests for analytes in drinking water supplies throughout the state for compliance with the Australian Drinking Water Guidelines (2011) (ADWG). These results were reported to SA Health in line with agreed reporting protocols. Compliance with the ADWG for E. coli was achieved in 99.97 per cent of metropolitan Adelaide samples and 99.96 per cent of regional samples. Overall compliance with the ADWG for health-related parameters was 99.98 per cent for metropolitan systems and 99.85 per cent for regional areas.

The total number of incidents notified by SA Water during 2022-23 (179) was higher than in 2021-22 (136) but most of this was due to an increase in Type 2 incidents. There were 2 Priority Type 1 incidents during 2022-23 for enteric protozoa detected in treated water samples. Both of these incidents were managed appropriately to prevent risks to drinking water quality.

The impact of the River Murray flooding event in December 2022 resulted in an increase in incidents particularly related to elevated levels of cyanobacteria, and physical parameters such as high turbidity. The flood waters contributed to overall poor water quality in the River Murray resulting in treatment and disinfection challenges at water treatment plants fed by River Murray water. Incidents relating to disinfection by-products also increased.

High rainfall events led to a significant increase in the detections of enteric protozoa (Cryptosporidium and Giardia) in drinking water catchments and source waters. There were 42 Type 2 incidents involving detection of enteric protozoa in the catchment following rain events or at the inlets to drinking water treatment plants. No faults were detected from the continuous monitoring of treatment plant performance during the periods when the protozoa were detected in the source water.

The number of incidents (9) related to recreational use of reservoir reserves was lower than in 2021-22 (20). The incidents did not have a measurable impact on drinking water quality.

There was a small increase in the number of detections of E. coli in drinking water samples in 2022-23. Appropriate remedial action was taken to minimise the impact to public health. Overall compliance of E. coli monitoring remained very high.

All water quality incidents were notified by SA Water 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. No incidents required public notification during the reporting period.

Safe drinking water legislation

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 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 with results showing a very high level of compliance.

An independent audit was undertaken in February 2023 as required by the Act.

The audit spanned a duration of 2 weeks focusing on examining a selection of representative drinking water supplies. It encompassed both desktop assessments and on-site visits which included travelling to the Anangu Pitjantjatjara Yankunytjatjara (APY) Lands.

The 2-week audit recognised overall compliance with the Act. Highlights identified by the auditor included:

  • A mature drinking water management system.
  • A culture that recognises the importance of drinking water quality – this is deeply embedded within the organisation and is to be applauded.
  • Staff who are adaptable, dedicated, skilled and sharing.
  • Water planning for, response during, and recovery from the River Murray flood. This event would test any organisation, and the level of dedication to ensuring the best outcomes are noted and congratulated.
  • Contract partners to SA Water are also much more integrated now into the overall delivery of safe water. It is apparent that water quality, not contractual limits is the primary driver of interactions, and all partners were observed to be undertaking their roles in a collaborative and cooperative fashion.
  • In response to previous audit findings, SA Water not only addressed the specific concerns but took a wider view to review the finding, determine the most appropriate solution and implement it across the business.

Overall, the audit showed a very high level of compliance, however, as expected, with a detailed audit, 2 non-conformances were identified as well as a number of improvement actions. As in previous years, these items will be assessed and corrective actions will be taken.

Catchment to tap

We manage drinking water quality from catchment to tap in line with our Drinking Water Quality Management System to ensure a consistent and reliable supply of high quality, safe drinking water for our customers. This management system is based on the Framework for Management of Drinking Water Quality outlined in the ADWG and endorsed by the National Health and Medical Research Council. The framework outlines good drinking water supply management, based on the best available scientific evidence that will assure drinking water quality and safety at the tap.

Water quality monitoring and testing

The 85 drinking water supplies we operate serve customers across metropolitan and regional South Australia. This year we have merged what was previously reported as country and remote Aboriginal communities into one category (regional).

To maintain quality, we have SA Health-approved drinking water quality monitoring programs with samples collected and analysed throughout all aspects of the water supply system, including catchment and source water, treatment processes, and the distribution network 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 field results have a high degree of integrity. Laboratory analyses are carried out by our Australian Water Quality Centre in accordance with ISO 9001 Quality Systems and NATA requirements.

Number of sample locations and test analytes – statewide, metropolitan, country and remote Aboriginal communities water supply systems, 2021-22

Drinking water systems





Supply systems





Customer tap sample locations





Catchment to tap sample locations*





Catchment to tap routine test analytes




Drinking water quality and performance

In 2022-23, we demonstrated robust management of water quality by consistently providing safe, clean drinking water to our customers despite the challenges posed by the flood event in the River Murray.

Statewide, metropolitan, country and remote Aboriginal communities drinking water supply systems health-related performance, 2022-23

Health-related parameters

Statewide systems (number of test analytes)

Metropolitan systems

(number of test analytes)

Country systems

(number of test analytes)

Samples free from E. coli

99.96% (10,229)

99.97% (3,167)

99.96% (7,062)

Samples compliant with ADWG health parameters*

99.89% (46,101)

99.98% (12,665)

99.85% (33,334)

Target: 99.90%

Target: 99.90%

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 46,089 test analytes from our drinking water supplies (customer tap sample locations) throughout South Australia to determine health-related compliance. We achieved 99.96 per cent E. coli compliance across customer tap sample locations with exceptions in one metropolitan and 3 regional systems. Compliance with ADWG health-related parameters across customer tap sample locations was marginally below target at 99.89 per cent. This result can be largely attributed to the flood event which saw a short-term rise in disinfection by-products in several of the systems fed directly from the River Murray.

Although we aim for 100 per cent compliance all the time, the ADWG recognises that occasional exceedances may occur with most guidelines for chemicals based on a lifetime of exposure. 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 corrective actions implemented as agreed with SA Health.

SA Health has confirmed that drinking water provided to customers by us was safe and that appropriate responses and corrective actions were implemented for all exceedances and these mitigated any risks to public health.

Incident management

We apply the ADWG Framework for Management of Drinking Water Quality which includes 2 components for the management of incidents:

  1. Communication
  1. Incident and emergency response protocols.

Our Water Quality Incident and Emergency Management Protocol is in place and we have a web-based incident management system to record and generate notifications of water quality incidents. These are aligned to the interagency Water/Wastewater Incident Notification and Communication Protocol that is maintained by SA Health to adopt the principles of the ADWG and satisfy 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:

  1. 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.

  1. Type 1 incident notification  

    An incident that, without appropriate response or intervention, could cause serious risk to human health.

  1. Type 2 incident notifications

An incident that, without appropriate response or intervention, represents a low risk to human health.

Statewide drinking water supplies number of incidents (metropolitan and regional)

Reporting period

Priority Type 1

Type 1

Type 2

























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 2022-23, there were 2 Priority Type 1 incidents reported due to the detection of Cryptosporidium in product water from a water treatment plant (WTP). In one of the instances, the WTP had ultraviolet disinfection, which is an effective barrier against Cryptosporidium, and in the other the Cryptosporidium was non-infectious.

The poor source water quality following the River Murray flooding event from December 2022 led to treatment and disinfection challenges in our water treatment plants and networks. This, in turn, caused an increase in turbidity, disinfection, disinfection by-products, cyanobacteria, enteric protozoa and bacteriological incidents.

During 2022-23, there was a decrease in chemical detections and a significant improvement in non-compliance at reservoirs with recreational access resulting in a decrease in contamination incidents.

The rise in Type 2 incidents can also be attributed to increased rainfall events during the year leading to an increase in enteric protozoa detections in our surface water catchments.

In 2022-23, we continued to address the causes of preventable Type 1 notifications. Strategies used to achieve this include refresher training, optimisation of our drinking water quality monitoring program, ongoing operational and capital improvements, and continuous improvement of our Drinking Water Quality Management System.

The proactive water quality management of targeted water supply systems and the detection and management of risks continued during 2022-23. Changes in reporting criteria issued by SA Health in the interagency Water/Wastewater Incident Notification and Communication Protocol also occurred and contributed to a change in reporting requirements.

Incident Response Index 

The Incident Response Index (IRI) drives and 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 Climate, Environment and Water by 3pm the next business day
  • root cause analysis completed within 10 working days
  • preventive actions implemented within agreed timeframes. The overall 2022-23 strategic target for the IRI is 85 per cent compliance.

The Incident Response Index achieved for metropolitan and regional incidents in 2022-23