Summary of Australia's Water Reuse Guideline or Regulation for Potable Water Reuse
This page is part of the EPA’s REUSExplorer tool, which summarizes the different country level regulations or guidelines for water reuse for a variety of sources and end-uses.
The source water for this summary are Stormwater and Treated Municipal Wastewater.
- Technical basis
- Applications of potable reuse approved for use in Australia
- Water reuse category/type
- Additional context and definitions
- Potable reuse specifications (table)
- Upcoming regulations
- References
- Disclaimer
This page is a summary of the country’s water reuse law or policy and is provided for informational purposes only. Please always refer to the country for the most accurate and updated information.
In Australia, potable water reuseThe use of highly treated recycled water for drinking water purposes. Includes the introduction of recycled water into an environmental buffer, such as groundwater aquifer or surface reservoir being withdrawn for potable purposes (indirect potable reuse), and the introduction of recycled water into a drinking water treatment facility or directly into a potable water distribution system (direct potable reuse). applications include indirect potable reuse and direct potable reuse. The sources of water stormwaterPrecipitation that is collected from land or impervious surfaces at a district or regional scale for the purpose of beneficial reuse. Rainwater collection at the building scale is classified separately under 'onsite collected waters.’ and treated municipal wastewater Treated wastewater effluent discharged from a centralized wastewater treatment plant of any size. Other terms referring to this source of water include domestic wastewater, treated wastewater effluent, reclaimed water, and treated sewage. are specified by Australia as stormwater and treated municipal wastewater. In Australia, stormwater includes rain draining from roofs, roads, footpaths and other ground surfaces, into stormwater catchment systems. The write-up adapted Australia’s terms when discussing sources or uses of water to match the Regulations and End-Use Specifications Explorer's (REUSExplorer's) terms.
Check out how Australia uses stormwater for centralized non-potable reuse.
Australia uses stormwater for a variety of applications, including potable water reuse and centralized non-potable reuse. Browse the centralized non-potable reuse summary page.
Technical basis
Australia has developed authoritative guidelines to support the use of treated municipal wastewater and stormwater for indirect potable water reuse applications, including reservoir water augmentation and managed aquifer recharge (NWQMS, 2006; 2008). The guidelines do not preclude direct potable reuse (DPR), but there is no specific guidance for DPR (South Australia Health, personal communication, November 28, 2023). Similar to the World Health Organization (WHO) water reuse guidance, Australia uses health-based microbial log-reduction targets (LRT) and chemical concentration targets for water quality monitoring (NWQMS, 2006; NWQMS, 2022; WHO, 2017). These LRT and chemical concentration targets vary based on the source of water and its different end uses, allowing the risk assessment of microbial and chemical hazards that could be present in wastewater to determine benchmark risks. Australian guidelines use disability adjusted life years (DALYs) for microbial hazards only, converting the estimated probabilities of infection or illness into burden of disease (NWQMS, 2006). DALYs are used to weigh health impacts in terms of severity and duration of disease and the number of people affected. One DALY is equivalent to the loss of one year of full health and it is the sum of years of life lost due to premature mortality (YLLs) and years lived with a disability (YLD) associated to a specific disease or health condition prevalence (WHO, 2023). In drinking water, DALYs are primarily used for microbial hazards, with 10-6 DALYs per person per year (pppy) being approximately equivalent to 1 case of diarrheal disease per 1,000 people per year. Australia set a benchmark risk threshold of 10-6 DALYs per person per year (pppy) for indirect potable water reuse. This risk threshold applies to microbial log-reduction targets (LRTs) only, and chemical concentration targets follow the Australian drinking water guidelines (ADWG, 2022).
Treatment guidelines are summarized in the table by source and end use. The technical basis for developing specifications and/or removal of debris, microbial contaminants and other relevant indicators is specified within Australia’s guidance documents for water recycling (NWQMS, 2006; 2008; 2009). The microbial LRTs were derived from first principles through Quantitative Microbial Risk Assessment (QMRA) techniques using the default concentrations listed in footnote ‘c’ below the table (South Australia Health, personal communication, November 28, 2023). The LRTs calculation assumes an adult’s average daily water consumption of 2 liters per year and pathogen doses equivalent to 10-6 DALY, i.e., 1.6×10-2Cryptosporidium, 2.5×10-3 rotavirus and 3.8×10-2Campylobacter (NWQMS, 2006; 2008). The guidelines are intended to be used as an authoritative reference for states and territories in Australia to provide the scientific basis for implementing regulations.
Potable water reuse applications approved for use in Australia
NWQMS (2008) defines the following approved planned potable uses for recycled treated municipal wastewater and stormwater:
- Indirect drinking (potable) water reuse: discharge of recycled water directly into groundwater or surface water with the intent of augmenting drinking water supplies (e.g., reservoirs, rivers and streams).
- Direct drinking (potable) water reuse: discharge of recycled water directly into drinking water treatment facility or into a drinking water distribution system (e.g., tap water) without going through an intermediary receiving body of water.
Water reuse treatment category/type
Australia states that recycled water that meets the defined health-based microbial LRTs and chemical concentration targets specified by the national, state or territory authority is considered safe for the specified end use.
Treatment guidelines are provided for potable water reuse in Australia. NWQMS (2009) outlines specific treatment processes:
- Lagoons and wetlands: The usage of lagoons and wetlands aid in reducing biochemical oxygen demand, heavy metals and nutrients, microbial pathogens through settling and inactivation and suspended solids through presence of vegetation.
- Primary and secondary sewage treatment: The reduction of microbial pathogens, biodegradable organics, volatile organic compounds and nutrients through biological and chemical treatment processes, together or separately.
- Tertiary: The removal of suspended solids, biological oxygen demand and pathogenic organisms. Different levels of tertiary treatment include dual-media filtration with coagulation, membrane filtration, reverse osmosis, chlorination, ozonation, activated carbon, advanced oxidation, disinfection and ultraviolet light. These reduce microbial pathogens and chemical hazards.
Additional context and definitions
NWQMS (2006) and NWQMS (2008; 2009) comprise the first and second phase of the Australian Guidelines for Water Recycling, respectively. The water quality targets, including chemical concentrations and microbial treatment performance (e.g., LRTs of pathogens in source waters), are the key health-based targets for potable water reuse. The guidelines are intended to be used as an authoritative reference for states and territories in Australia to provide the scientific basis for implementing regulation. However, states and territories examine potable reuse applications on a case-by-case basis (South Australia Health, personal communication, November 28, 2023).
NWQMS (2008) provides guidance on preventative measures for recycled water systems for potable water reuse. Australia encourages the collection and recycling of stormwater and treated municipal wastewater for potable water reuse. However, states and territories may have unique regulations that differ from the National Water Quality Management Strategy (NWQMS) guidelines (e.g., approved chemicals and materials, system management and maintenance).
Potable water reuse specifications
The specifications presented in the table include some parameters to be monitored in potable recycled water in Australia. The NWQMS federal guidelines provide detailed information about these parameters (NWQMS, 2006; 2008; 2009).
Summary of Australia's Potable Water Reuse Specifications
| Recycled Water Class/Category | Source Water Type | Water Quality Parameter | Specificationsa | Sampling/Monitoring Requirements (Frequency of monitoring; site/ location of sample; quantification methods)b |
|---|---|---|---|---|
| Potable water reuse | Treated municipal wastewater and stormwater | Aluminum | 0.2 mg/L | Baseline monitoring of pathogens, inorganic chemicals and organic chemicals requires weekly testing of source waters and Receiving waters for pathogens or indicators and monthly testing for chemicals (at least 12 months) to identify hazards and characterize seasonal variability |
| Arsenic | 0.007 mg/L | |||
| Barium | 0.7 mg/L | |||
| Boron | 0.3 mg/L | |||
| Cadmium | 0.002 mg/L | |||
| Chromium (III) | Not specified | |||
| Chromium (VI) | 0.05 mg/L | |||
| Chromium (total) | Not specified | |||
| Cobalt | Not specified | |||
| Copper | 2.0 mg/L | |||
| Fluoride | 1.5 mg/L | |||
| Iron | Not specified | |||
| Lead | 0.01 mg/L | |||
| Lithium | Not specified | |||
| Manganese | 0.5 mg/L | |||
| Methylmercury | Not specified | |||
| Mercury (inorganic) | 0.001 mg/L | |||
| Molybdenum | 0.05 mg/L | |||
| Nickel | 0.02 mg/L | |||
| Selenium | 0.01 mg/L | |||
| Uranium | Not specified | |||
| Vanadium | Not specified | |||
| Zinc | Not specified | |||
| Treated municipal wastewater | Cryptosporidium | 8 log-reductionc | ||
| Enteric viruses | 9.5 log-reductionc | |||
| Campylobacter | 8.1 log-reductionc |
Source = NWQMS (2006; 2008)
a Australia uses guideline chemical concentrations published in the Australian drinking water guidelines (NWQMS, 2022).
b Limited information about sampling and monitoring requirements such as frequency, site and quantification methods was provided in the NWQMS guidelines.
c Estimated LRTs to comply with the benchmark risk of 10-6 DALY pppy. These estimates assume an initial concentration of 2,000 Cryptosporidium, 8,000 rotavirus and 7,000 Campylobacter per liter of raw wastewater (NWQMS, 2008).
Upcoming regulations
No upcoming reuse regulations related to potable water reuse were found for Australia.
References:
Geneva: World Health Organization (WHO). 2017. Potable reuse: Guidance for Producing Safe Drinking-Water.
Geneva: WHO. 2023. Disability-adjusted life years (DALYs).
National Water Quality Management Strategy (NWQMS). 2022. Australian Drinking Water Guidelines (ADWG) 6 (version 3.8).
NWQMS. 2009. Australian Guidelines for Water Recycling: Managing Heath and Environmental Risks (Phase 2). Stormwater Harvesting and Reuse.
NWQMS. 2008. Australian Guidelines for Water Recycling: Managing Heath and Environmental Risks (Phase 2). Augmentation of Drinking Water Supplies.
NWQMS. 2006. Australian Guidelines for Water Recycling: Managing Health and Environmental Risks (Phase 1).
Please contact us at waterreuse@epa.gov if the information on this page needs updating or if this state is updating or planning to update its laws and policies and we have not included that information on the news page.