尽管在过去十年中，离开处理设施的水的质量有了显著改善，但在配水系统中检测大肠菌群仍然会给供水商带来问题。很难确定配送系统中大肠菌群失效的原因。过去的许多研究都集中在管壁生物膜内大肠菌群的存活和/或生长上。然而，这项工作大多是基于实验室的，尚未在现场得到证实。影响配水系统水质的因素有很多，包括资产状况、网络活动、净化水库的完整性，以及客户管道状况。 本文介绍了过去两年开展的研究结果，这些研究采用整体方法，通过考虑所有“风险”因素，结合使用网络建模技术，确定配电系统中大肠菌群故障的原因。包括19个参考文献、图表。

Despite significant improvements over the past ten years in the quality ofwater leaving treatment facilities, the detection of coliform organisms in distribution systems still causes problems for water suppliers. Determining the cause of coliform failuresin distribution systems is difficult. Much of the research in the past has concentrated on the survival and/or growth of coliform organisms within biofilms on pipe walls. However,much of this work has been laboratory based and has not been proven in the field. There are a number of factors that can affect the quality of water in distribution systems, includingthe condition of the assets, network activity, integrity of treated water reservoirs, and the condition of the customers' plumbing. This paper presents the results of studies carried out over the past two years which take a holistic approach to determining the causes of coliform failures in distribution systems by considering all the "risk" factors in conjunction with the use of network modeling techniques. Includes 19 references, figures.