密歇根州安娜堡市研究了现有处理工艺的改进，以符合国家三卤甲烷总量初级饮用水临时法规（TTHMs），并试验了使用氯和氯胺的各种消毒方案。预氯化后添加到原水中的无水氨将TTHM浓度降低到100微克/升的要求水平。还对预氯化后氯化和中间氯化后氯化进行了检查。详细介绍了使用不同氯化点的氯残留、最大电位和瞬时TTHM生成，以及使用氨时整个处理过程中的氯残留总量。包括6个参考文献、表格、图表。

In studying existing treatment process modifications for compliance with the National Interim Primary Drinking Water Regulations for total trihalomethanes (TTHMs), the city of Ann Arbor, Michigan experimented with a variety of disinfection schemes using chlorine and chloramines. Anhydrous ammonia, added to the raw water after prechlorination, reduced TTHM concentrations to the required level of 100 micrograms/L. Both prechlorination-postchlorination and intermediate chlorination-postchlorination were examined also. Details on chlorine residuals using the various chlorination points, maximum potential and instantaneous TTHM formation, and total chlorine residuals throughout the treatment process when ammonia was used are given. Includes 6 references, tables, figures.