PDF(Pubmed)
Abstract：
Water scarcity and increasing urbanization are forcing municipalities to consider alternative water sources, such as stormwater, to fill in water supply gaps or address hydromodification of receiving urban streams. Mounting evidence suggests that stormwater is often contaminated with human feces, even in stormwater drainage systems separate from sanitary sewers. Pinpointing sources of human contamination in drainage networks is challenging given the diverse sources of fecal pollution that can impact these systems and the non-specificity of traditional fecal indicator bacteria (FIB) for identifying these host sources. As such, we used a toolbox approach that encompassed microbial source tracking (MST), FIB monitoring, and bacterial pathogen monitoring to investigate microbial contamination of stormwater in an urban municipality. We demonstrate that human sewage frequently contaminated stormwater (in >50% of routine samples), based on the presence of the human fecal marker HF183, and often exceeded microbial water quality criteria. Arcobacter butzleri, a pathogen of emerging concern, was also detected in >50% of routine samples, with 75% of these pathogen-positive samples also being positive for the human fecal marker HF183, suggesting human municipal sewage as the likely source for this pathogen. MST and FIB were used to track human fecal pollution in the drainage network to the most likely point source of contamination, for which a sewage cross-connection was identified and confirmed using tracer dyes. These results point to the ubiquitous presence of human sewage in stormwater and also provide municipalities with the tools to identify sources of anthropogenic contamination in storm drainage networks.IMPORTANCEWater scarcity, increased urbanization, and population growth are driving municipalities worldwide to consider stormwater as an alternative water source in urban environments. However, many studies suggest that stormwater is relatively poor in terms of microbial water quality, is frequently contaminated with human sewage, and therefore could represent a potential health risk depending on the type of exposure (e.g., irrigation of community gardens). Traditional monitoring of water quality based on fecal bacteria does not provide any information about the sources of fecal pollution contaminating stormwater (i.e., animals/human feces). Herein, we present a case study that uses fecal bacterial monitoring, microbial source tracking, and bacterial pathogen analysis to identify a cross-connection that contributed to human fecal intrusion into an urban stormwater network. This microbial toolbox approach can be useful for municipalities in identifying infrastructure problems in stormwater drainage networks to reduce risks associated with water reuse.
摘要：
缺水和日益城市化迫使市政当局考虑替代水源，比如雨水，填补供水缺口或解决接收城市溪流的加氢改造问题。越来越多的证据表明雨水经常被人类粪便污染，即使在雨水排水系统与下水道分离。鉴于可能影响这些系统的各种粪便污染源以及传统粪便指示细菌（FIB）用于识别这些宿主源的非特异性，因此查明排水网络中的人类污染源具有挑战性。因此，我们使用了包含微生物源跟踪(MST)的工具箱方法，FIB监控，和细菌病原体监测，以调查城市城市雨水的微生物污染。我们证明，人类污水经常污染雨水(在>50%的常规样本中)，基于人类粪便标记物HF183的存在，并且经常超过微生物水质标准。Butzleri杆菌,一种新出现的病原体，在>50%的常规样本中也检测到，这些病原体阳性样品中的75％也对人类粪便标记物HF183呈阳性，这表明人类市政污水可能是该病原体的来源。MST和FIB用于将排水网络中的人类粪便污染追踪到最可能的点污染源，使用示踪染料鉴定并确认了污水交叉连接。这些结果表明雨水中普遍存在人类污水，并为市政当局提供了识别雨水排放网络中人为污染源的工具。重要水资源短缺，城市化进程加快，和人口增长正在推动全球市政当局将雨水视为城市环境中的替代水源。然而,许多研究表明，雨水在微生物水质方面相对较差，经常被人类污水污染，因此，根据暴露类型，可能代表潜在的健康风险(例如，社区花园的灌溉)。传统的基于粪便细菌的水质监测不提供关于污染雨水的粪便污染源的任何信息(即，动物/人类粪便)。在这里，我们提供了一个使用粪便细菌监测的案例研究，微生物源跟踪，和细菌病原体分析，以确定导致人类粪便侵入城市雨水网络的交叉连接。这种微生物工具箱方法可用于市政当局识别雨水排放网络中的基础设施问题，以减少与水再利用相关的风险。
