Application of HACCP to Re-Evaluate Secondary Disinfection

饮用水的二次消毒旨在防止分配系统的入侵，抑制生物膜和机会性病原体，并作为系统故障的哨兵。尽管有这些经常被提及的目标，但没有基于证据的法规或指南来定义实现这些目标所需的二级消毒剂的类型或浓度。相反，100年来，二次消毒的做法基本保持不变，很少有人试图确定它们是否在发挥作用，以及在多大程度上发挥了作用。这正变得越来越不可接受，因为有证据表明，发达国家饮用水暴发的大多数疾病可能归因于分配系统的故障，人们越来越意识到新型消毒副产物，以及住宅管道中存在机会性病原体。**拟议的研究将通过危害分析和关键控制点（HACCP）方法，结合定量微生物风险评估（QMRA），重新评估二次消毒需求。这项工作将确定阻碍HACCP/QMRA模型完成的研究差距，并确定申请人通过第三方资助或由其他人进行进一步研究的优先领域。风险评估工作将辅以实地、试点和实验室规模的案例研究，以研究拟议的新型二级消毒剂——稳定过氧化氢——满足HACCP分析确定的需求的能力。**拨款将支持培训14名高素质人员，他们将学习风险分析技能，以及水处理操作和各种微生物和化学分析的应用技能。这是高价值的技能，可以直接转移到环境工程行业。**拟议的工作本身不会改变二次消毒做法：资源和范围太有限。目的是使用HACCP和QMRA工具创建一个合理的框架，以便首次使用定量绩效指标对二次消毒进行严格评估，并发现和确定需要进一步调查的优先领域。这将激发饮用水领域的一个新的研究方向，最终将导致更合理的、基于健康的二次消毒实践和法规。

Secondary disinfection of drinking water is intended to protect against intrusion in distribution systems, suppress biofilm and opportunistic pathogens, and serve as a sentinel of system failure. Despite these commonly-cited objectives, there is no evidence-based regulation or guideline that defines the type or concentration of secondary disinfectant required to achieve them. Instead, secondary disinfection practices have remained largely unchanged for 100 years, with little attempt to determine whether, and to what extent, they are doing their job. This is becoming increasingly unacceptable, as evidence suggests that the majority of outbreaks of disease from drinking water in developed countries may be attributable to failures in the distribution system, and awareness grows about new classes of disinfection by-products, and the presence of opportunistic pathogens in premise plumbing. **The proposed research will re-evaluate secondary disinfection needs through a hazard analysis and critical control point (HACCP) approach, coupled with quantitative microbial risk assessment (QMRA). The work will identify research gaps that inhibit the completion of the HACCP/QMRA models, and identify priority areas for further research to be undertaken by the applicant through third party funding, or by others. The risk assessment work will be supplemented by a field-, pilot-, and laboratory-scale case study of the ability of a proposed new secondary disinfectant, stabilized hydrogen peroxide, to meet the needs identified by the HACCP analysis. **The funding will support the training of 14 highly qualified personnel, who will learn skills in risk analysis as well as applied skills in water treatment operation and the performance of a variety of microbiological and chemical analyses. This are high value skills that are directly transferrable to the environmental engineering industry.**The proposed work will not transform secondary disinfection practices on its own: the resources and scope are too limited. The intent is to use HACCP and QMRA tools to create a rational framework to allow secondary disinfection to be critically assessed using quantitative performance metrics for the first time, and to discover and identify priority areas for further investigation. This will stimulate a new research direction in the drinking water community, which will ultimately lead to more rational, health-based secondary disinfection practices and regulations.