包括太平洋西北部的许多大型水务公司在内的几家大型水务公司依靠流域管理、持续的水质检查和强化消毒措施来维持安全用水，而不是过滤。作者根据他们在华盛顿州西雅图和塔科马供水系统的经验撰写了这篇文章，并得出结论:强制过滤所有地表水系统似乎是不合理的。包括10篇参考文献。

Several large water utilities, including many in the Pacific Northwest, rely on watershed management, ongoing examination of water quality, and enhanced disinfection practices to maintain safe water instead of filtration. The authors base this article on their experience with the Seattle and Tacoma water systems in the state of Washington and conclude that mandatory filtration for all surface water systems does not seem to be justifiable. Includes 10 references.