饮用水法规强调对工厂废水进行监测，但工厂和客户水龙头之间的水质可能会恶化。虽然消毒剂和消毒副产品（DBPs）的命运已经在受控、恒定的实验室条件下进行了检查，但研究尚未完全调查它们在全尺寸分配系统中的命运。本研究追踪了两个全尺寸饮用水分配系统中氯和溶解有机卤素（DOX）浓度随水停留时间（RT）的变化。随着配水系统中RT的增加，游离氯和总氯浓度降低。管道尺寸也会影响氯的衰变，尤其是在温水中；在类似的RTs中，小直径管道中的氯浓度最低，主管中的氯浓度更高，分批培养中的氯浓度最高。管道中的腐蚀副产物似乎是影响分配系统中氯衰变的主要因素； 一些DBP的化学不稳定性和微生物生物量的存在似乎是影响DOX的主要因素。影响配水系统水质的因素很多——管道材料、直径、腐蚀副产物和生物膜的存在、RT、水温、消毒剂残留物和水力条件。为了保持通过昂贵的处理工艺获得的高水质，供水商需要更好地了解这种水质如何在配水系统中退化。有了这些信息，他们可以更好地确定消毒剂剂量，以符合监管要求，并在分配系统的所有点保护他们的供应。包括45个参考文献、表格和图表。

Drinking water regulations emphasize monitoring at the plant effluent, but water quality can deteriorate between the plant and the customer's tap. Although the fate of disinfectants and disinfection byproducts (DBPs) has been examined in controlled, constant laboratory conditions, research has not fully investigated their fate in full-scale distribution systems. This study tracked changes in the concentrations of chlorine and dissolved organic halogens (DOX) as a function of water residence time (RT) in two full-scale drinking water distribution systems. Free and total chlorine concentrations decreased with increasing RT in the distribution system. Pipe size also influenced chlorine decay, especially in warm water; at similar RTs, chlorine concentrations were lowest in small-diameter pipes, greater in the main pipes, and greatest in the batch incubations. Corrosion byproducts in pipes appeared to be the major factor affecting chlorine decay in the distribution system; chemical instability of some DBPs and the presence of microbial biomass seemed to be the main factor influencing DOX. Numerous factors affect water quality in the distribution system - pipe materials, diameter, presence of corrosion byproducts and biofilm, RT, water temperature, disinfectant residuals, and hydraulic conditions. To preserve the high water quality obtained by expensive treatment processes, water providers need a better understanding of how that quality can degrade in the distribution system. Armed with this information, they can make better determinations of disinfectant dosages to comply with regulatory requirements and protect their supplies at all points of the distribution system. Includes 45 references, tables, figures.