本研究的目的是研究两个地区THM的空间和季节演变 基于高频数据采集程序的大型实用程序。这两个公用设施位于 在魁北克市地区（加拿大）。因为收集与水公用事业中氯化副产物（CBPs）相关的数据 在魁北克省，2001年6月之前没有强制规定，目前几乎没有 关于这些化合物在植物和分布之间变化的信息 系统本文列出了正在研究的公用事业的一般特征。 该分析的数据是在两个不同阶段生成的。第一阶段是对三卤甲烷的研究 （THM）在1999年5月至2000年9月期间进行的变更，第二阶段代表 2000年9月至2000年9月期间对三卤甲烷和卤乙酸（HAAs）进行了同步研究 2001年。第一阶段的设计目的是在季节基础上比较入口和出口之间的THM水平 分配系统的点（氯化后）和系统末端。第二阶段 本研究旨在基于多个地点的抽样研究THMs和HAAs的空间演化 配送系统中的位置。在该区域内选择采样点的标准 配电系统数量众多:这些点必须位于距离工厂不同的位置， 有利于改变水的停留时间；它们必须位于从上游到下游的在线位置 下游的至少有一个点必须代表分配系统的极限； 全部的 这些点必须由处理厂直接提供，因此不受再氯化的影响 配电系统内的设施或储水设施；而且，所有的要点都必须明确 可在一年中的同一天、每周进行采样。 从5月到9月的第一阶段和第二阶段（地表变化 水温更高）每周或每月采集两次样本，以便 详细评估水质的变化。1999年10月至2000年4月期间 而地表水被冰雪覆盖，水温的变化就不那么显著了 每月采集样本。对采集的样品进行了不同水质的分析 质量和操作参数:pH（pH计）；温度（便携式温度计）；自由的 余氯（DPD滴定法，标准方法4500 Cl）；总有机碳 （使用未过滤样品的总碳分析仪）；UV-254吸光度（紫外线/可见光） 分光光度法）；以及THMs和HAA5（电子捕获色谱法，EPA 551,2和552,2方法， 分别）。前三个参数是在现场测量的，其他参数是在实验室进行的 拉瓦尔大学。用于在两次采集之间保存样本的程序 分析采用标准方法（APHA、AWWA、WEF，1996）推荐的方法。包括13个参考文献、表格、图表。

The objective of this study was to examine the spatial and seasonal evolution of THMs in two large size utilities based on a high-frequency data collection program. The two utilities are located in the Quebec City region (Canada). Because the collection of data related to chlorination byproducts (CBPs) in water utilities in the province of Quebec was not mandatory before June 2001, there is currently very little information concerning variations in these compounds between the plant and the distribution system. The paper lists the general characteristics of the utilities under study. The data for this analysis were generated in two different phases. Phase 1 represents a study of trihalomethanes (THM) variations carried out between May 1999 and September 2000, and Phase 2 represents a simultaneous study of both THMs and haloacetic acids (HAAs) carried out between September 2000 and September 2001. Phase 1 was designed to compare THM levels, on a seasonal basis, between the entrance point of the distribution system (following post-chlorination) and the system extremities. Phase 2 was designed as a study of the spatial evolution of THMs and HAAs based on sampling at several locations within the distribution system. The criteria for selecting sampling points within the distribution systems were numerous: the points had to be located at variable distances from the plant, to favor variable residence times of water; they had to be located on-line from upstream to downstream; at least one point had to represent the extremity of the distribution system; all points had to be supplied directly by the treatment plant, so there was no influence of rechlorination facilities or water storage within the distribution system; and, all points had to be accessible for sampling the same day, every week over a year. For both Phase 1 and Phase 2 from May to September (a period at which the variations of surface water temperature are greater) samples were collected weekly or twice per month in order to assess the variations on water quality in detail. From October 1999 to April 2000, the period when soil and surface water are covered by snow and ice, variations in water temperature are far less notable and samples were collected monthly. The collected samples were analyzed for different water quality and operational parameters: pH (pH-meter); temperature (portable thermometer); free residual chlorine (DPD titrimetric method, Standard method 4500-Cl); total organic carbon- TOC (total carbon analyzer using unfiltered samples); UV-254 absorbance (UV/visible spectrophotometry); and, THMs and HAA5 (E-capture chromatography, EPA 551,2 and 552,2 methods, respectively). The first three parameters were measured in the field, the others in the laboratory at Universit¿ Laval. The procedures used for the conservation of the samples between their collection and analysis were those recommended by Standard Methods (APHA, AWWA, WEF, 1996). Includes 13 references, tables, figures.