Water reuse: innovative monitoring technologies for risk reduction

随着全球变化影响饮用水水源的可获得性和质量，世界各地越来越多的社区正在转向废水回用，以满足其供水需求。尽管对于供不应求的干旱或半干旱地区来说，水再利用是一个重要的潜在饮用水来源，但湿润气候的大城市地区的扩张往往导致事实上或计划外的间接废水再利用。尽管废水含有广泛的环境污染物，但人类病原体仍然是优先考虑的问题。传统上，对大肠杆菌等可培养粪便指示菌的常规监测一直是评估水质的标准方法。然而，化验至少需要18-24小时才能为饮用水处理厂运营商或水资源管理人员提供结果。因此，以大肠杆菌培养为基础的方法不能进行快速和经济有效的决策。对于水的再利用，重要的是确定风险较高的时期，特别是在导致废水处理不完整的事件很常见的情况下(例如，处理绕过、混合下水道溢出、设备故障、维修期间的计划排放等)。 正在开发新的快速、自动化的在线技术，以促进水中大肠杆菌的检测。样品是自动采集的，用于直接测量-D-葡萄糖苷酶的活性，这是一种大肠杆菌特有的酶，不需要漫长的培养步骤。从样本采集到结果的时间从18-24小时缩短到30分钟。这项研究计划旨在通过确保更多的供应，同时减少非计划的水再利用对人类健康的影响来提高源水的安全性。研究的目标是：1)评估加拿大的水再利用现状；2)开发一个新的工具集，用于快速评估水质，以提高安全性；3)创建一种新的方法，在正常运行和活动期间监控计划内和计划外的水再利用；以及4)在考虑全球变化的影响的同时，提出一种新的基于风险的饮用水水源地水再利用管理策略。这些新颖和创新的技术将安装在作为计划外水再利用的良好范例的现场。这些设备将以精细的时间分辨率测量大肠杆菌的动态，以识别、表征和预测源水和饮用水处理过程中的大肠杆菌峰值浓度。随着越来越多的社区转向水再利用来供水，有必要了解和减轻人类健康风险，并提出监管或监测框架，以制定水质标准并确保达到这些标准。7名研究生和5名本科生将接受适用于城市水管理的最新技术培训，以支持更健康社区的新政策。

As global change influences the availability and quality of drinking water sources, greater numbers of communities around the world are turning to wastewater reuse to satisfy their water supply needs. Although water reuse is an important potential drinking water source for arid or semi-arid regions where the demand can exceed available supplies, the sprawl of large urban metropolitan areas in humid climates has frequently led to de facto or unplanned indirect wastewater reuse. Although wastewaters contain a wide suite of environmental contaminants, human pathogens remain a priority. Traditionally, routine monitoring of culturable fecal indicator bacteria such as Escherichia coli have been the standard approach for assessing water quality. However, assays require a minimum of 18-24 hours before results are available for drinking water treatment plant operators or water resources managers. Thus, E. coli culture-based methods do not allow for rapid and cost-effective decision making. For water reuse, it is important to identify periods of higher risk, particularly as events leading to incomplete wastewater treatment are common (e.g. treatment bypasses, combined sewer overflows, equipment failures, planned discharges during repairs, etc.). New rapid, automated online technologies are being developed to facilitate E. coli detection in water. Samples are autonomously collected for direct measurements of -D-glucoronidase activity, an enzyme specific to E. coli, without a lengthy cultivation step. The time from sample collection to result is shortened from 18-24 hours to 30 minutes. This research program aims to improve the safety of source waters by ensuring greater availability of supplies while reducing the impact of unplanned water reuse on human health. The research objectives are to: 1) evaluate the current state of water reuse in Canada, 2) develop a novel toolset for rapid assessment of water quality to improve safety, 3) create a new approach for monitoring planned and unplanned water reuse during normal operation and during events, and 4) propose a new risk-based strategy for managing water reuse in drinking water sources while considering the impact of global change. The novel and innovative technologies will be installed at field sites that are good examples of unplanned water reuse. Devices will measure E. coli dynamics at a fine temporal resolution to identify, characterize and predict peak E. coli concentrations in the source water and through drinking water treatment. As more communities turn to water reuse for water supply, there is a need to understand and mitigate human health risks and to propose regulatory or monitoring frameworks to set water quality criteria and ensure that they are met. Seven graduate students and 5 undergraduate students will be trained in state of the art technologies applicable to urban water management in support of new policies for healthier communities.