Monis Paul, Lau Melody, Harris Martin, Cook David, Drikas Mary
Australian Water Quality Centre, South Australian Water Corporation, GPO Box 1751, Adelaide, SA 5001, Australia.
Food Waterborne Parasitol. 2017 Aug 30;8-9:64-74. doi: 10.1016/j.fawpar.2017.08.002. eCollection 2017 Sep-Dec.
The safety of drinking water in Australia is ensured using a risk management framework embedded within the Australian Drinking Water Guidelines (ADWG). This framework includes elements for hazard identification, risk assessment, risk mitigation, verification of barrier performance and monitoring for any changes to the hazards that influence source water quality. The next revision of the ADWG will incorporate Health-Based Targets (HBTs) for achieving microbiologically safe drinking water. This incorporates Quantitative Microbial Risk Assessment and the metric of Disability Adjusted Life Year (DALY) to define safety, with a target of 1 × 10 Disability Adjusted Life Year (1 microDALY) set as the maximum tolerable disease burden from drinking water, which in the case of is < 1.3 × 10 oocysts/L. The resulting product water specification, in combination with knowledge of pathogen challenges in source waters, allows the determination of the treatment requirements to ensure public safety. The ADWG revision provides default removal values for for particular treatment processes, such as conventional coagulation and dual media filtration. However, these values are based on assumptions regarding treatment plant design, operation and water quality. To properly manage risk and demonstrate compliance with the guidelines, water utilities may need to validate treatment performance for removal. A particular limitation is the absence of surrogates for full-scale filter validation. This paper will provide an overview of risk-based management of drinking water safety in Australia, the development of health-based targets for microbial pathogens and the evaluation of surrogates for conventional coagulation and dual media filtration.
澳大利亚饮用水的安全是通过澳大利亚饮用水指南（ADWG）中所包含的风险管理框架来确保的。该框架包括危害识别、风险评估、风险缓解、屏障性能验证以及对影响原水水质的危害变化进行监测等要素。ADWG的下一版修订将纳入基于健康的目标（HBT），以实现微生物安全的饮用水。这纳入了定量微生物风险评估以及伤残调整生命年（DALY）指标来定义安全性，设定1×10伤残调整生命年（1微DALY）为饮用水可承受的最大疾病负担目标，对于而言，该目标为<1.3×10卵囊/升。由此得出的产品水规格，结合对原水中病原体挑战的了解，能够确定确保公共安全所需的处理要求。ADWG修订版为特定处理工艺（如常规混凝和双层介质过滤）提供了隐孢子虫的默认去除值。然而，这些值基于对处理厂设计、运行和水质的假设。为了妥善管理风险并证明符合指南要求，供水企业可能需要验证隐孢子虫去除的处理性能。一个特别的限制是缺乏用于全尺寸过滤器验证的隐孢子虫替代物。本文将概述澳大利亚基于风险的饮用水安全管理、针对微生物病原体的基于健康目标的制定以及对常规混凝和双层介质过滤的隐孢子虫替代物的评估。
