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Australian Drinking Water Guidelines: Draft framework on microbial health based targets

Closed on Friday, 4 November 2016, 11:59pm (AEDT). Submissions are no longer being accepted.

The Australian Drinking Water Guidelines 2011 (ADWG) have been developed by the National Health and Medical Research Council (NHMRC) and are designed to provide an authoritative reference to the Australian community and the water supply industry on what defines safe, good quality drinking water, how it can be achieved and how it can be assured. The ADWG undergo rolling revision to ensure they represent the latest and best scientific evidence on good quality drinking water.

Microbial health based targets (HBT) are used to provide a quantitative definition of microbiological safety of drinking water.  Reference organisms that represent the major groups of pathogens (bacteria, viruses and protozoa) can be used. While achieving zero health risk from the consumption of treated drinking water is unrealistic, HBT provides a definition for a low level of acceptable risk.

HBT have been adopted in the Australian Guidelines for Water Recycling, and the United States Environmental Protection Agency, World Health Organization and Health Canada guidelines for drinking water. 

Currently, the only HBT for microbial safety in the ADWG is the absence of Escherichia coli (E. coli) per 100 millilitres of water.  However, E. coli is not an effective indicator organism for other bacteria in drinking water and cannot be used as an indicator for viral and protozoan pathogens.

The draft framework describes a range of options for utilities to meet HBTs. For smaller utilities this could involve using default treatment processes based on categorising the type of water source. For more technically advanced utilities a more system-specific approach using water supply-specific monitoring data (where this exists) can be used.  For utilities that do not meet the existing standards in the ADWG, the HBT framework describes a water safety continuum, where the utility can plan improvements to its operation in order to work towards the goal of safer water and best practice. 

The draft framework consists of two parts, Chapter 5 and appendices.  Chapter 5 details the science and rationale of microbial HBT in the context of source water, such as applying HBT to drinking water supplies, determining minimum treatment requirements for drinking water supplies, specified treatment technologies for small or remote drinking water, and information on operational monitoring. The appendices explain the specific technical details of applying HBT to water supplies, such as how to calculate log reduction values (LRV), how to conduct source water assessments, and an explanation of default LRV credits for common water treatment processes.  

NHMRC is seeking public comment on the draft framework on HBT in the ADWG. You are invited under paragraph 13(d) of the NHMRC Act 1992 to make a submission to NHMRC about the draft framework. 

Issues raised during public consultation on other aspects of the ADWG or water quality will not be considered through this process. 

Consultation documents

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Consultation date

Please note the Timezone is AEDT.

Opening date: 
Monday, 5 September 2016 - 9:00am
Closing date: 
Friday, 4 November 2016 - 11:59pm
Extension: 
Please note that for some NHMRC consultations no extensions will be given. Where extensions are available you will need to contact the project officer using the contact details at the bottom of this page. However, in order for NHMRC to extend the date of a submission you will need to have created an account and started a submission.
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Page reviewed: 14 September, 2016