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 2019-20, SA Water collected 46,416 samples from drinking water supplies throughout the state. Samples were analysed for compliance with the Australian Drinking Water Guidelines (2011) (ADWG) and results reported to SA Health in line with agreed reporting protocols. Compliance with the ADWG for E. coli was achieved in 100 per cent of metropolitan Adelaide samples, 99.96 per cent of country samples and 100 per cent of remote Aboriginal community samples. Overall compliance with the ADWG for health-related parameters was 100 per cent for metropolitan systems, 99.91 per cent for country areas and 99.32 per cent for remote community supplies.

The total number of incidents notified by SA Water during the reporting period was higher compared to 2018-19. The majority of this total increase was due to incidents arising from unauthorised activities in 2019-20 at drinking water reservoir reserves now open for people to visit. Warmer than average temperatures and periods of above average rainfall resulted in increased numbers of incidents reported due to detection of cyanobacteria and enteric protozoa in source water. The number of incidents in relation to customer complaints of dirty water was also higher. These are generally short-term events associated with maintenance activities. Incidents associated with disinfection were reduced in 2019-20 compared to 2018-19.

The impact of bushfire and the subsequent substantial rain event on the Middle River Water Treatment Plant were expertly handled. SA Water personnel are commended for their response and ongoing communication during the event and the recovery. There were impacts on aesthetic quality of the drinking water supply yet despite the damage to the treatment plant, supply of drinking water through the Middle River system to Kingscote was maintained at all times. Exceedances were recorded for manganese and aluminium concentrations and these were resolved appropriately.

Water quality incidents were notified by SA Water in a timely manner. Appropriate remedial actions were implemented and ensured 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 provides the regulatory framework for drinking water providers in South Australia and is administered primarily by SA Health with assistance from local government. 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 (RMPs)
  • 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 accredited laboratories for sample testing
  • reporting of water quality test results to SA Health and providing consumers with drinking water quality information.

SA Water is registered as a drinking water provider and has established RMPs including approved monitoring programs and an incident notification protocol. SA Water provided water quality testing reports for metropolitan, country and remote community water supplies on a monthly basis with results showing a very high level of compliance.

Under the Act, SA Water is required to undergo an annual independent audit. In 2019-20, the sixth audit of SA Water was undertaken since the Act took effect. A number o  representative SA Water drinking water supplies were included in the audit. The audit outcomes were consistently positive and noted that SA Water was operating in compliance with the requirements and intent of the Act. Compliance improved relative to the five previous audits and no significant non-compliances were detected.

Further information on the Safe Drinking Water Act 2011 can be found at sahealth.sa.gov.au/safedrinkingwateract

SA Water also provides additional information regarding water quality which can be found at sawater.com.au

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 87 drinking water supplies we operate serve customers across metropolitan, country and remote Aboriginal communities within South Australia.

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 the requirements of the National Association of Testing Authorities.

The following table summarises routine monitoring and testing activities in our SA Health-registered drinking water supply systems in 2019-20.

Number of sample locations and test analytes – statewide, metropolitan, country and remote Aboriginal communities water supply systems, 2019-20

Drinking water systems

Statewide

Metropolitan

Country

Remote Aboriginal communities

Supply systems

87

8

59

20

Customer tap sample locations

503

177

306

20

Catchment to tap sample locations*

1,511

369

1,021

121

Catchment to tap routine test analytes

372,352

79,580

289,997

8,682

* Includes customer tap sample locations

Drinking water quality and performance

In 2019-20, we demonstrated robust management of water quality by consistently

providing safe, clean drinking water to our customers.

The following table summarises our performance for health-related parameters

of routine samples at customer tap sample locations.

Statewide, metropolitan, country and remote Aboriginal communities drinking water supply systems health-related performance, 2019-20

Health-related parameters

Statewide systems (number of test analytes)

Metropolitan systems

(number of test analytes)

Country systems

(number of test analytes)

Remote Aboriginal communities

(number of test analytes)

Samples free from E. coli*

99.97% (10,307)

100% (3,221)

99.96 (6,995)

100% (91)

Samples compliant with ADWG health parameters*

99.93% (46,416)

100% (13,388)

99.91% (32,438)

99.32% (590)

Target: 99.90%

Target: 100%

Target: 99.80%

Target: 99.80%

* 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 46,416 routine test analytes from our drinking water supplies (customer tap sample locations) throughout South Australia to determine health-related compliance.

  • We achieved 99.97 per cent E. coli compliance across customer tap sample locations with exceptions in three country systems.
  • Compliance with ADWG health-related parameters across customer tap sample locations was above target at 99.93 per cent.

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 appropriate responses and corrective actions were implemented in all cases and these mitigated any risks to public health.

The three E. coli detects in 2019-20 were all in the presence of chlorine or chloramine residuals at levels high enough to mitigate risk. Plant operation, chlorine/chloramine residuals and bacterial results from different locations around the time of the detects were reviewed and were all within specifications. Follow up samples were taken showing consistent chlorine/ chloramine residual and no E. coli detected.

The greatest challenge to country compliance is disinfection by-products due to several South Australian source waters containing high amounts of natural organic matter. We have identified these systems and are proactively implementing management strategies to address these situations.

From 1 July 2019 we took on the responsibility of the Wirrina Cove water supply system from the District Council of Yankalilla. Since then we have installed a specialised aerator and are currently constructing a granular activated carbon plant, both of which will help remove disinfection by-products from the water, as well as improve its taste and smell.

Following positive feedback from Myponga township residents after changing the treatment chemical used to disinfect their water from chlorine to chloramine, we are now progressing with the chloramination of the wider Myponga drinking water system in two stages.

In 2019-20 we undertook planning, design and construction works at the Myponga Water Treatment Plant to facilitate this water quality improvement, which is designed to mitigate disinfection by-product challenges, with the additional benefit of improving the taste and smell of the water.

After assuming responsibility for the water supplies of Kanpi, Murputja and Nyapari in late 2017 we have now completed a water supply upgrade project that links these supplies together and includes storage and reverse osmosis (RO) treatment at Murputja. The water in this area has naturally occurring fluoride above the ADWG health limit and the RO treatment will reduce levels within the guidelines as well as improve the aesthetics of the water.

Year in review_E.coli compliance_2019-20-01

Incident management

We are committed to applying the ADWG Framework for Management of Drinking Water Quality which includes two components for the management of incidents:

  1. communication
  2. 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 Safe Drinking Water Act 2011 and Safe Drinking Water Regulations 2012.

SA Health defines three 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.

2. Type 1 incident notification

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

3. Type 2 incident notifications

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

Following is a comparative summary of the Priority Type 1, Type 1 and Type 2 incident notifications reported against the interagency Water/Wastewater Incident Notification and Communication Protocol.

Statewide drinking water supplies number of incidents (metropolitan, country and remote Aboriginal communities)

Reporting period

Priority Type 1

Type 1

Type 2

2019-20

1

36

63

2018-19

1

24

54

2017-18*

2

42

90

2016-17#

2

48

159

2015-16

4

32

74

Note: these notifications do not include wastewater, recycled water and non-drinking supplies.

* Remote Aboriginal communities incidents included in annual reporting from 2017-18.

# Impacted by River Murray blackwater event.

Priority Type 1 and Type 1 incidents are immediately reported to SA Health, while all

Type 2 notifications reportable within 24 hours, in line with the interagency Water/

Wastewater Incident Notification and Communication Protocol.

The Priority Type 1 incident was due to the Duncan and Ravine bushfires on Kangaroo Island when the Middle River Water Treatment Plant sustained significant damage leaving it inoperable for about two weeks. In consultation with SA Health, untreated but disinfected raw water from Middle River Reservoir was approved as safe to drink and supplied to the network. In addition, we supplied boxed, bottled and tinkered water to ensure ongoing alternative drinking water supplies for the community. An incident management team was setup and convened daily for the duration of the Incident.

In 2019-20 the number of incidents, particularly Type 1 notifications, increased when compared with 2018-19. This can be largely attributed to an increase in source water incidents with 12 recreational access incidents recorded. This new incident category was introduced in 2019-20 as reservoir reserves began to be progressively opened for public access. In addition, we had three Type 1 cyanobacteria incidents at the newly acquired Wirrina Cove Water Treatment Plant system. There was a reduction in disinfection failures and filtered water turbidity incidents, primarily due to improved process monitoring and control systems at water treatment plants.

In 2019-20, we continued our focus on early detection and reporting to external agencies, briefing the Minister for Environment and Water, ensuring prompt corrective action and addressing the causes of preventable Type 1 notifications, such as disinfection failures and filtered water turbidity exceedances. 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 detection and management of risks continued during 2019-20. 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 assist the management of water quality incidents, including reporting, initial response and longer-term preventive measures. The overall 2019-20 strategic target for the IRI was 85 per cent compliance.

Criteria used in the Incident Response Index (based on total reportable SA Health Priority Type 1 and Type 1 incident notifications)

Incident reported to relevant agencies by phone immediately

(less than one hour)

Overall strategic 2019-20

target: 85%

Incident entered into the incident management system

in less than two hours

Initial effective response taken within three hours

Written report to Minister for Environment and Water

by 3pm next business day

Root cause analysis completed within 10 working days

Preventive actions implemented within agreed timeframes

The continual review and improvement of our incident management processes has

positively impacted our overall water quality incident response and performance,

maintaining an overall score well above our target.

The Incident Response Index achieved in metropolitan, country and remote Aboriginal communities and overall for 2019-20, compared to 2018-19

System

IRI 2018-19

IRI 2019-20

Statewide (weighted combined metropolitan, country and remote

Aboriginal communities)

96%

98%

Metropolitan

99%

98%

Country

97%

98%

Remote Aboriginal communities

67%

100%

Safe Drinking Water Act audit

In November 2019, we were audited under the Safe Drinking Water Act 2011 (the Act), and successfully met all our legislative requirements. The successful outcome of the audit found:

  • We operate in compliance with both the explicit requirements and the implied intent of the Act, Regulation, SA Health audit report template and the ADWG. Our people and contractors consistently demonstrated this compliance and understanding of the need for such vigilance.
  • The audited sites and systems demonstrated improved compliance relative to the five previous audits (2014 to 2018) and showed positive responses to findings from those previous audits. The result was evidence of continual improvement in the spirit of the ADWG.
  • The expertise of our people in water quality management was impressive and the auditor had confidence in how we discharged our responsibilities and showed our genuine organisational commitment to water quality management. The standard of our supporting systems was high and all 12 elements of the ADWG Framework were fully implemented.
  • Final water verification monitoring and reporting continues to be leading nationally and was both drawing on international best practice methods and developing globally leading approaches.
  • There were no significant non-compliances uncovered during the audit, that is, no findings that constituted an immediate potential threat to public health that required urgent action or reporting.

Overall, it was concluded that our water quality management planning was mature, embedded, extensive and comprehensive.

The audit result demonstrates the good level of collaboration across the business, with our contract partners, and SA Health.