Key messages
- Under the Safe Drinking Water Act 2003 (the Act), the Department of Health must be notified if drinking water does not, or is not likely to, comply with water quality standards.
- Water suppliers and water storage managers (collectively referred to as water agencies) must report to the department if water supplied, or to be supplied, for drinking purposes may pose a health risk or cause widespread public complaint.
- Section 18 of the Act applies when drinking water does not comply, or is not likely to comply, with any relevant water quality standard. The department must be notified in writing within 10 days.
- Section 22 of the Act applies when drinking water may not be safe or be the cause of widespread public complaint. An officer of a water agency must immediately provide a verbal report to the department and submit a section 22 form so the incident can be triaged by the Health Regulator.
- Regulation 20 outlines additional details that must be included when reporting under sections 18 and 22 of the Act.
Under the Safe Drinking Water Act 2003 (the Act), the Department of Health must be made aware if drinking water does not comply, or is likely not to comply, with the standards. The department must also be made aware if water supplied, or to be supplied, for drinking purposes may pose a health risk or cause widespread complaints.
These obligations are set out in sections 18 and 22 of the Act.
Guidance has been developed to assist water agencies to comply with sections 18 and 22 of the Safe Drinking Water Act 2003 and regulation 20 under the Safe Drinking Water Regulations 2025.
Section 18 notifications
Section 18 notifications apply when a water supplier becomes aware that their supplied drinking water does not comply, or is unlikely to comply, with any relevant water quality standard. The notification must be made within 10 days of the water supplier becoming aware.
For the purposes of section 18, the 'relevant water quality standard' refers to the drinking water quality standards specified under regulation 16 of the Safe Drinking Water Regulations 2025 (the Regulations).
There are drinking water quality standards for 3 characteristics that each water supplier must test drinking water for at a minimum frequency in each water sampling area (Table 1).
Table 1
| Characteristics | Minimum sampling frequency | Quality standard |
|---|---|---|
| Escherichia coli (E. coli) | One sample per week | The drinking water does not contain E. coli. |
| Total Trihalomethanes (TTHM) | One sample per month | Samples do not exceed the health guideline value specified in Table 10.6 of the Australian Drinking Water Guidelines (currently 0.25 milligrams per litre of drinking water for TTHMs). |
| Turbidity | One sample per week | The 95th percentile of results for samples in any 12-month period does not exceed to 5.0 Nephelometric Turbidity units (NTU). |
The compliance requirements for regulation 16(2)(b) for characteristics that do not have a minimum sampling frequency are that the drinking water does not exceed the Australian Drinking Water Guidelines (ADWG) health-based guideline value as listed in Table 10.6 of the ADWG for any characteristic tested as part of the water agency’s drinking water sampling program.
For more details on health-based guideline values, see Chapter 10 of the Australian drinking water .
The compliance requirements for regulation 16(2)(c) are that if the drinking water contains any characteristic – other than those listed in Table 10.6 of the ADWG with a health-based guideline value, or E. coli – that the drinking water does not contain that characteristic alone, or in combination with any other characteristic, in an amount that would pose a risk to human health.
Notification must be made using the notification form, Section 18 - Notifying of non-complying water.
Related to this notification, note that regulation 20 of the requires water suppliers to provide a written summary of sample analysis results to the department where the results indicate that the water supplied contravenes a drinking water quality standard.
See the guidance for more information on drinking water quality standard.
Section 22 reports
Section 22 reports apply when drinking water contamination is suspected or believed to:
- be the cause of an illness
- be the means by which an illness is being, has been or will be, transmitted
- contain any pathogen, substance, chemical or blue-green algae toxin at levels that may pose a risk to human health
- cause widespread public complaint.
An officer of a water supplier or water storage manager (collectively referred to as water agencies) must immediately report their suspicion or belief.
Once the verbal report has been made, the section 22 written form must be submitted to the Health Regulator as soon as possible. Your liaison officer can assist you in completing the form if required.
If the section 22 report has been made as a result of an analysis of a drinking water sample, a written summary of those results, previous results and actions taken or proposed to be taken in response to the results, must be included in the summary report to be submitted under regulation 20 requirements.
Immediate reporting
An officer of a water agency should immediately report under section 22 to the department by phone:
- During business hours, contact the department’s Health Regulator.
- If there is no response or if the report is to be made outside business hours, contact the department's public health emergency pager (24-hour service).
See the Section 22 - Reporting known or suspected contamination of drinking water form for more detail.
Written reporting
Following an immediate verbal report, the reporting officer is required to complete the section 22 form from the best available information relevant to the contamination event or incident.
Water sampling test results relevant to the report must be provided to the Secretary under regulation 20 within 10 days of their receipt.
See Regulation 20 for more information.
Notification is made using the department's notification form, Section 18 - Notifying of non-complying water.
Section 22 reporting examples
These situations outline the department's expectations of what might need a section 22 report. These examples are based on experience and the list is not exhaustive.
Water agencies should immediately contact the department to discuss any concerns or queries regarding section 22 reports.
Raw water
- Raw water quality issues or reservoir contamination including accident or chemical spill, algal bloom, wildlife/fish deaths, turbid runoff or contamination from a rainfall event, flood or fire, in such a way that may affect treatment (degrade the performance of barriers to contamination or exceed the capability of treatment barriers).
- Any other raw water event that could potentially make drinking water supplied to consumers the cause of an illness or a risk to health, or give rise to widespread public complaint.
Barrier failure – Critical Control Point
- Failure or imminent potential for failure of one or more barriers to contamination or critical control points (CCP) for that supply system, in such a way that may make the drinking water supplied, or to be supplied, to consumers the cause of an illness or a risk to human health.
- Inadequately disinfected water (i.e. water that breaches the CCP), being supplied, or which may be supplied, to consumers for drinking.
Pathogen risk events
- Any detection of Escherichia coli detection or any other human pathogens in drinking water that may be supplied to consumers.
- Evidence of vermin (birds, possums or other animals) found in treated water storages.
Chemical risk events
- Overdose of a chemical applied in water treatment or disinfection processes, or dosing with contaminated water treatment chemicals, such that the water may pose a risk to health if supplied to consumers.
- Any detected chemical, toxin, substance or pathogen in drinking water at a level above a health-based drinking water quality standards. This includes short-term and long-term (chronic) exposure risks to public health.
Asset condition and integrity
- Suspected sabotage, vandalism, threat, or extortion bid at any drinking water facility that may affect the quality of drinking water supplied to consumers.
- Damage to water supply asset integrity due to extreme weather events or bushfires.
Public reporting
- Reports of an illness or illnesses that are suspected to have resulted from the drinking water supplied.
- Widespread public complaints about drinking water quality, including taste and odour.
Regulation 20 reports
Regulation 20 outlines requirements to report results of sample analysis in specified circumstances.
The reports are due within 10 days of the water receiving the relevant sample results.
Regulation 20(1)(a) requires reporting where sample analysis results indicate a prescribed drinking water quality standard has been contravened.
Regulation 20(1)(b) requires the reporting where sample results that indicate any characteristic measured may pose a risk to public health or results in widespread public complaint.
Regulation 20(2) requires that reports include details of sample analysis results, in addition to previous results relating to the relevant characteristic, and also must include details of actions taken or proposed to be taken in response to results reported.
Together, subregulations (a) and (b) support reporting of details to the Secretary relating to requirements of sections 18 and 22 of the Act.
Reports under Regulation should be made using the Regulation 20 - Reporting sample analysis results form.
Reviewed 10 July 2025