The Australian Drinking Water Guidelines (the Guidelines) provide guidance to water regulators and suppliers on monitoring and managing drinking water quality.
April 2023: Please note NHMRC has identified an error of minor significance in the September 2022 update to the microbial water quality guidance (Chapter 5 and Appendix 3 of the Guidelines). Information about the error and the proposed corrections that will be made to the next version of the Guidelines are outlined below in the Public Notice.
The Australian Drinking Water Guidelines (the Guidelines) provide a basis for determining the quality of water to be supplied to consumers in all parts of Australia. They are intended to provide a framework for the good management of drinking water supplies that if implemented will assure safety at the point of use. The Guidelines are not mandatory legally enforceable standards and the implementation of the guidelines is at the discretion of each state and territory. The Guidelines are used by state and territory health departments and drinking water regulators, local health authorities and water utilities.
The Guidelines undergo a rolling revision to ensure they represent the latest scientific evidence on good quality drinking water. As sections of the Guidelines are revised, the Table of updates will be updated to provide the latest information.
For specific information on how these Guidelines are implemented in the states and territories, please contact the relevant drinking water regulator or health department.
Update 28 April 2023
PUBLIC NOTICE: Proposed Minor corrections to microbial water quality guidance in the Australian Drinking Water Guidelines (Chapter 5 and Appendix 3)
NHMRC has identified an error of minor significance in Chapter 5 and Appendix 3 of the Guidelines. An incorrect adjustment value has been applied to the Category 4 protozoa log reduction value (LRV). The final LRVs are not affected by this error and it does not change the recommendations in the Guidelines. The final default LRV targets in Chapter 5 and Appendix 3 have been reviewed and supported by the current Water Quality Advisory Committee and the jurisdictional experts on the Environmental Health Standing Committee (enHealth) Water Quality Expert Reference Panel.
The identified errors are in the explanatory text and footnotes in several places in Chapter 5 and Appendix 3 of the Guidelines. Corrections will be made in these places to clarify how the final LRV was reached and will be published in the next version of the Guidelines. The corrections that will be made to the Guidelines are outlined in Table 1 below.
On 30 March 2023 the Council of NHMRC advised the CEO that the proposed changes to the Guidelines are of minor significance and that public consultation is not required prior to making the updates. This public notice of proposed amendments fulfills the notification requirements in accordance with section 9 of the National Health and Medical Research Council Regulation 2016. This information will be moved into the table of updates when the corrections have been made in the next version of the Guidelines.
|Page||Summary of proposed edits||Current (September 2022) Guideline text||Proposed corrected Guideline text|
|90||Edits to correct text explaining rounding and adjustments in the Guidelines||Therefore, the LRVs included in Table 5.5 are rounded to the nearest 0.5 log and represent the upper end of ranges shown in Table A3.8. Additionally, due to the observed overestimate of infective oocysts with standard methods for Cryptosporidium in Australian catchments the LRVs for protozoa in Table 5.5 have been reduced by 1 log10 for Category 1 to Category 3 catchments and 0.5 log10 for Category 4 catchments.||Therefore, the LRVs included in Table 5.5 are rounded to the nearest 0.5 log and represent the upper end of ranges shown in Table A3.8. Additionally, due to the observed overestimate of infective oocysts with standard methods for Cryptosporidium in Australian catchments, the LRVs for protozoa in Table 5.5 have been reduced by 1 log10 for Category 2 to Category 4 catchments.|
|1173||Edits to correct footnote 1 of Figure A3.1||1 1.0 log10 for Categories 1 to 3 and 0.5 log10 for Category 4.||1 -1.0 log10 for Categories 2 to 4.|
|1183||Addition of a sentence to the end of the paragraph beginning ‘Infectivity of Cryptosporidium…’||Longer retention times in reservoirs or in river runs with limited impacts close to points of abstraction (e.g. vulnerability classes 1 and 2) are likely to provide further reductions of infectivity. However, these studies show variable results.||…… However, these studies show variable results. Based on the results for speciation and infectivity, the LRV targets for Cryptosporidium shown in Table A3.9 have been reduced by 1 log10.|
|1184||Edits to correct and replace footnote 2 in Table A3.9||(2) The LRV was based on the upper 95th credible interval on the mean for the confirmed recovery-adjusted Cryptosporidium concentration (oocysts/L) for representative catchments as presented in Deere et al. (2014), with Category 1 to 4 being anchored to reference catchments 4B, 3C, 2B and 5C, respectively, and with infectious oocyst concentrations being estimated to be below the confirmed oocyst concentrations by 1 log for categories 1 to 3 and 0.5 log for category 4 due to the latter lacking inner catchment protection.||(2) The LRV was based on the estimated arithmetic mean of total oocyst counts for different Australian source waters. Total counts typically overestimate human infectious oocysts, and therefore an infectivity discount factor of -1.0 log10 was applied to obtain the LRV target. For high-risk sources (e.g. category 4), the discount factor may need to be reduced (e.g. to -0.5 log10) which will change the required LRV. This should only be done in consultation with the relevant health authority or drinking water regulator.|
Table of updates
|Amendment type||Amendment detail||Date updated||Version number||Administrative report|
|Updated guidance on microbial quality of drinking water||Guidance on microbial health-based targets has been developed to assist water regulators and suppliers in better managing health risks from microorganisms found in drinking water. Information in Chapter 5 has been updated to reflect current best practice in managing health risks from microorganisms found in drinking water and Appendix 3 provides details on the derivation of microbial treatment targets for enteric pathogens.
Consequential amendments have been made throughout the guidelines to ensure consistency with updated guidance on microbial quality of drinking water.
A Questions and answers resource has been prepared to highlight the key changes and provide information on the new concepts introduced in the revised guidance.
|September 2022||3.8||Administrative Report: Updated guidance on microbial quality of drinking water
Chapter 5: Microbial health-based target update – Questions and answers resource
|Updated guidance on radiological water quality||Information and terminology in Chapter 7, parts of Chapter 10, Information Sheet 2.2 and factsheets on radium, alpha and beta radionuclides, radon-222 and radiological aspects of the uranium factsheet have been updated to reflect current best practice in radiation protection and radiation measurement.||January 2022||3.7||Administrative Report: Updated guidance on radiological water quality|
|Minor edits to correct errors in the Guidelines||
|New guidance on short-term exposure values added to Chapter 9 (Section 9.12)||Guidance on short-term exposure values has been developed to assist water regulators and suppliers in managing instances where temporary drinking water contamination occurs, such as during extreme weather events.||March 2021||3.6||Administrative Report: Guidance on Short-Term Exposure Values|
|Minor amendments||Editorial changes have been made to correct minor errors, including:
|Development of a new Chemical Fact Sheet: Per-fluoroalkyl and poly-fluoroalkyl substances (PFAS)||Health Based Guideline Values and a Fact Sheet on PFAS have been developed. These have been informed by a review conducted by Food Standards Australia New Zealand (FSANZ) to determine Australian Tolerable Daily Intakes (TDIs) for perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonate (PFHxS).||August 2018||3.5|
|Development of a new Chemical Fact Sheet - lanthanum||Chemical Fact Sheet on lanthanum has been developed following a Secondary Notification risk assessment by the National Industrial Chemicals Notification and Assessment Scheme||October 2017||3.4||Review of lanthanum fact sheet for inclusion in the Australian Drinking Water Guidelines 2011|
|Text added to Chapter 6||
|Text added to Chapter 10||Addition of guidance for comparing analytical results with rounded guideline values.||November 2016||3.3|
|Minor amendments||Editorial changes have been made to correct minor errors, and update references.||November 2016||3.3|
|Removal of text from Chapter 5 – Microbial Quality of Drinking Water||
|Removal of Appendix 3 – National Water Quality Management Strategy||This Appendix is significantly out of date and has been deleted.||November 2016||3.3|
|Removal of Appendix 4 – Process Report||
|Minor amendments to Chapters 8 and 10, Tables 8.4 and 10.5, Information Sheets 1.4, 1.6 and 2.1, and Fact Sheets on Campylobacter, Salmonella and Vibrio||Editorial changes have been made to correct minor errors, provide further clarification and context, and update references.||March 2015||3.1|
|Review and update of three Chemical Fact Sheets – chloral hydrate, monochloramine and chlorine||Chemical Fact Sheets on chloral hydrate (originally endorsed in 1996), monochloramine (last endorsed in 2011) and chlorine (last endorsed in 2011) have been reviewed and updated following a review of recent literature, including the World Health Organization guidelines for drinking water quality and to correct a rounding error. The guideline value for chloral hydrate has changed. The equivalent guideline value for monochloramine as Cl2/L has changed, which also resulted in a consequential change to the chlorine Fact Sheet.||19 December 2014||3.0|
|Minor amendments to contents page and Table 10.5 in relation to changes to the Fact Sheets for chloral hydrate, monochloramine and chlorine||Editorial changes have been made to provide further clarification and update guideline values and naming conventions.||19 December 2014||3.0|
|Review and update of eight information sheets for water treatment operators on water disinfection. Includes: Introduction to water treatment, Overview of water disinfection, Disinfection with chlorine, Disinfection with chloramine, Disinfection with chlorine dioxide, Disinfection with ozone, Disinfection with ultra-violet light, Other disinfectant||These Information Sheets replace the previous Information Sheets which were developed in 2004 and were very general in nature. In revising the Information Sheets, the Water Quality Advisory Committee considered the information on water disinfection already included in the 2011 ADWG, international standards including the WHO Drinking-water Guidelines, and reviewed the recent literature on water disinfection. This information was integrated to produce the revised Information Sheets on disinfection of drinking water, which include additional information on practical aspects of water disinfection.||13 December 2013||2.0|
|Review and update of four chemical Fact Sheets – benzene, toluene, ethylbenzene and xylenes||Chemical Fact Sheets on Benzene, Toluene, Ethylbenzene and Xylenes (originally endorsed in 1996) have been reviewed and updated following a review of recent literature, including the World Health Organization guidelines for drinking water quality. The guideline values for these chemicals have not been changed as a result of the review.||13 December 2013||2.0|
|New resource – Guidance for issuing and lifting a Boil Water Advisory||A new resource has been developed to assist health and environment department officials determine when to issue and lift boil water notices following a drinking water contamination incident. This document has been developed by the WQAC at the request of jurisdictions, following recent natural disasters which led to possible drinking water contamination.||13 December 2013||2.0|
- The 2011 version of the Guidelines is only available electronically as a bookmarked PDF.
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This document (available from the download section below) describes the process for the review of the 2004 Australian Drinking Water Guidelines and the development of the 2011 Australian Drinking Water Guidelines. It was previously Appendix 4 to the Australian Drinking Water Guidelines (2011).