Act Now: Meeting Victoria’s 2025 Microbial Health-Based Target
Victoria’s new Safe Drinking Water Regulations (SDWR) 2025 introduce stricter requirements for water operators. A key focus is the mandatory adherence to the microbial health-based targets (HBTs) outlined in the Australian Drinking Water Guidelines (ADWG). This marks a significant shift, placing a greater emphasis on proactive risk management and transparent reporting.
In this article, we’ll outline Victoria’s microbial HBTs and explore how water agencies can achieve and maintain compliance using a sophisticated water management system.
Common Microbes in Drinking Water
According to the ADWG, pathogens that may be present in drinking water are classified into five types:
1. Viruses: These are minuscule organisms made of RNA or DNA that require a host to replicate. Without a host, they can survive in the environment for extended periods.
2. Bacteria: These are single-celled microorganisms and common harmful types include Escherichia coli (E. coli), Campylobacter, and Salmonella.
3. Protozoa: Like bacteria, they are single-celled organisms but are more complex and have nuclei. Pathogenic protozoa like Cryptosporidium and Giardia are of particular concern in water safety.
4. Helminths: These are parasitic worms transmitted via microscopic eggs in water. Due to their large size, helminths are generally managed effectively through treatment processes that control protozoa.
5. Fungi: This group includes yeasts and filamentous fungi. There is limited research on the presence and health impacts of fungi in treated drinking water, and they are not typically a primary focus of water quality guidelines.
Understanding the Disability-Adjusted Life Year (DALY)
The Disability-Adjusted Life Year (DALY) is a critical public health metric used to measure the overall burden of a disease. One DALY represents the loss of one year of “healthy life”.
A DALY is the sum of two components:
- Years of Life Lost (YLL): This accounts for the years lost due to premature death caused by a waterborne disease.
- Years Lived with a Disability (YLD): This accounts for the years spent living with an illness or disability from a waterborne disease, such as cholera.
By combining these two factors, the DALY metric gives a comprehensive comparison of the health impact of different waterborne hazards.
What Are Microbial Health-Based Targets (HBTs)?
Health-based targets are measurable objectives for drinking water quality. They serve as benchmarks for water suppliers and regulators, guiding efforts to ensure water is safe and to drive continuous improvement.
In the ADWG, HBTs are defined through two primary components:
1. A health outcome target: This specifies a defined, tolerable burden of disease. For drinking water safety regarding microbes, the standard health outcome target is a maximum of 1×10−6 DALY, or one microDALY (μDALY) per person per year (pppy).
This is the same target recommended by the World Health Organisation (WHO). The target of 1 μDALY pppy essentially means that, on average, a population of 1 million people should lose no more than one healthy year of life due to waterborne illnesses each year.
2. Treatment performance targets: These targets specify the level of treatment required to achieve microbially safe water. Expressed as a “log reduction value” (LRV) for a specific microbe, it indicates the percentage of microbes that must be removed or inactivated by treatment processes.
A 1-log reduction means that 90% of a specific pathogen is removed or inactivated. This table outlines LRVs further:
| Log Reduction | Percentage Reduction |
| 1-log reduction | 90% |
| 2-log reduction | 99% |
| 3-log reduction | 99.9% |
| 4-log reduction | 99.99% |
Assessing Microbial Risks in Drinking Water
It’s crucial to understand that the microbial health outcome target of 1 μDALY pppy is an operational benchmark, and isn’t a pass or fail measurement.
It’s impossible to ensure “zero risk”, as some pathogens do exist in our drinking water. The problem is when the concentration is high enough that it’s deemed unsafe for human consumption.
Being slightly below the health outcome target does not necessarily mean the water is unsafe, but rather that there is room for improvements to reduce the overall health risk. Therefore, a water quality risk framework should define a tolerable or safe level.
To achieve this level of compliance, a Quantitative Microbial Risk Assessment (QMRA), a framework recommended by WHO, is an invaluable tool. QMRA involves quantifying each component of the exposure pathway, from the source of the pathogen to the estimated health outcome.
This method is highly effective for answering quantitative questions, such as “What is a safe level of risk?” and “What level of treatment is necessary to achieve this safety goal?” By using QMRA, water agencies can make informed decisions to ensure they meet the new regulatory standards and, most importantly, provide safe drinking water to the public.
CCPWatchTM: Assessing Microbial Risks Automatically and Achieving Compliance
With stricter drinking water standards in Victoria, water agencies need to understand the implications and review whether their current systems and risk management plans can meet these new obligations.
Under the new regulations, they need to rigorously monitor water quality and apply effective risk management strategies to ensure drinking water consistently meets the microbial HBTs.
The new SDWR mandates that water agencies must report any shortfall in meeting the microbial HBTs to the Secretary of the Department of Health (DOH) within 10 days of an incident. This is defined as failing to meet the specified LRV that corresponds to the 1 μDALY target.
Furthermore, Section 22 of the Safe Drinking Water Act 2003 mandates that water operators or suppliers immediately report to the DOH if they suspect the water could cause illness, contains pathogens that may cause illness, or instigate public complaints.
Organisations need to monitor critical control points (CCPs) throughout the water network to detect microbial risks instantly, apply the right treatment and procedures to ensure the water continues to meet standards, and compile reports for the DOH.
D2K Information offers a cloud-based water management system, Information Engine™ (IE), designed in accordance with Australia’s water quality standards and the latest SDWR requirements.
Through the CCPWatchTM module, the system can:
- Monitor CCP data in real time and assess whether it is meeting the requirements in the ADWG and SDWR 2025
- Send SMS and email alerts automatically when CCP readings are beyond required levels.
- Generate daily logs automatically
- Compile and generate compliance reports that meet Section 22 requirements and other Australian water standards
- Retain data for 10 years
- Display a user-friendly dashboard with snapshots, alerts, and relevant data to get teams up to speed.
Additionally, we can tailor the system to meet the exact requirements of any organisation focused on maintaining water quality.
Meet New Regulations Quickly and Confidently
Victoria’s SDWR 2025 signals a clear shift towards stricter, more proactive management of microbial risks in drinking water. The regulations place greater responsibility on water agencies to monitor, report, and act swiftly to protect public health.
With the right systems in place, such as continuous CCP monitoring, automated alerts, and streamlined reporting, water operators can confidently meet their legal obligations while ensuring the community’s drinking water remains safe.
The fact is, embracing advanced water management solutions is no longer optional; it’s essential to staying compliant, minimising risks, and safeguarding public trust.
If you’re interested, we’d love to show you a demo of how CCPWatchTM can help you meet new obligations easily, save you time, and improve operational efficiency. We’re here to help you take the guesswork out of compliance and keep public health as your number one priority.
