这篇扩展的摘要简要概述了一篇正在为 美国环境保护局（USEPA）。美国环保局目前正在修订总大肠菌群规则（TCR），并正在考虑 作为这些修订的一部分，可能会有新的配电系统要求。作为这个过程的一部分， 美国环境保护局正在就与TCR相关的主题撰写一系列专题论文。这扩展了 摘要提供了二级消毒剂的概述，现有消毒剂的概述 剩余的指导方针和要求，讨论了中学的三大职能 消毒，以及二级消毒剂在执行这些功能时的效力。包括13篇参考文献。

This extended abstract provides a brief overview of an issue paper that is under development for the U.S. Environmental Protection Agency (USEPA). The USEPA is currently revising the Total Coliform Rule (TCR) and is considering new possible distribution system requirements as part of these revisions. As part of this process, the USEPA is developing a series of issue papers on topics relevant to the TCR. This extended abstract provides an overview of secondary disinfectants, an overview of existing disinfectant residual guidelines and requirements, a discussion of the three main functions of secondary disinfection, and the efficacy of secondary disinfectants in carrying out these functions. Includes 13 references.