本文讨论了1980年发生在匹兹堡郊区的一个供水系统的故意污染事件。从系统未受影响的部分用饮用水冲洗系统，直到污染物被清除。冲洗可以在大约一个月内恢复用水，但需要九个月才能消除所有化学物质的痕迹。包括数字。

This paper discusses a purposeful contamination event of a suburban Pittsburgh water system that occurred in 1980. The system was flushed with drinking water from an unaffected part of the system until the contaminant was purged out. Flushing was able to restore water use in about one month, but nine months were required to eliminate all traces of the chemical. Includes figures.